Large photonic band gaps and strong attenuations of two-segment-connected Peano derivative networks

International Nuclear Information System (INIS)

Lu, Jian; Yang, Xiangbo; Zhang, Guogang; Cai, Lianzhang

2011-01-01

In this Letter, based on ancient Peano curves we construct four kinds of interesting Peano derivative networks composed of one-dimensional (1D) waveguides and investigate the optical transmission spectra and photonic attenuation behavior of electromagnetic (EM) waves in one- and two-segment-connected networks. It is found that for some two-segment-connected networks large photonic band gaps (PBGs) can be created and the widths of large PBGs can be controlled by adjusting the matching ratio of waveguide length and are insensitive to generation number. Diamond- and hexagon-Peano networks are good selectable structures for the designing of optical devices with large PBG(s) and strong attenuation(s). -- Highlights: → Peano and Peano derivative networks composed of 1D waveguides are designed. → Large PBGs with strong attenuations have been created by these fractal networks. → New approach for designing optical devices with large PBGs is proposed. → Diamond- and hexagon-Peano networks with d2:d1=2:1 are good selectable structures.

Using minimal spanning trees to compare the reliability of network topologies

Science.gov (United States)

Leister, Karen J.; White, Allan L.; Hayhurst, Kelly J.

1990-01-01

Graph theoretic methods are applied to compute the reliability for several types of networks of moderate size. The graph theory methods used are minimal spanning trees for networks with bi-directional links and the related concept of strongly connected directed graphs for networks with uni-directional links. A comparison is conducted of ring networks and braided networks. The case is covered where just the links fail and the case where both links and nodes fail. Two different failure modes for the links are considered. For one failure mode, the link no longer carries messages. For the other failure mode, the link delivers incorrect messages. There is a description and comparison of link-redundancy versus path-redundancy as methods to achieve reliability. All the computations are carried out by means of a fault tree program.

Structural covariance networks across the life span, from 6 to 94 years of age

Directory of Open Access Journals (Sweden)

Elizabeth DuPre

2017-10-01

Full Text Available Structural covariance examines covariation of gray matter morphology between brain regions and across individuals. Despite significant interest in the influence of age on structural covariance patterns, no study to date has provided a complete life span perspective—bridging childhood with early, middle, and late adulthood—on the development of structural covariance networks. Here, we investigate the life span trajectories of structural covariance in six canonical neurocognitive networks: default, dorsal attention, frontoparietal control, somatomotor, ventral attention, and visual. By combining data from five open-access data sources, we examine the structural covariance trajectories of these networks from 6 to 94 years of age in a sample of 1,580 participants. Using partial least squares, we show that structural covariance patterns across the life span exhibit two significant, age-dependent trends. The first trend is a stable pattern whose integrity declines over the life span. The second trend is an inverted-U that differentiates young adulthood from other age groups. Hub regions, including posterior cingulate cortex and anterior insula, appear particularly influential in the expression of this second age-dependent trend. Overall, our results suggest that structural covariance provides a reliable definition of neurocognitive networks across the life span and reveal both shared and network-specific trajectories. The importance of life span perspectives is increasingly apparent in understanding normative interactions of large-scale neurocognitive networks. Although recent work has made significant strides in understanding the functional and structural connectivity of these networks, there has been comparatively little attention to life span trajectories of structural covariance networks. In this study we examine patterns of structural covariance across the life span for six neurocognitive networks. Our results suggest that networks exhibit

Refined Analysis of Fatigue Crack Initiation Life of Beam-to-Column Welded Connections of Steel Frame under Strong Earthquake

Directory of Open Access Journals (Sweden)

Weilian Qu

2017-01-01

Full Text Available This paper presents a refined analysis for evaluating low-cycle fatigue crack initiation life of welded beam-to-column connections of steel frame structures under strong earthquake excitation. To consider different length scales between typical beam and column components as well as a few crucial beam-to-column welded connections, a multiscale finite element (FE model having three different length scales is formulated. The model can accurately analyze the inelastic seismic response of a steel frame and then obtain in detail elastoplastic stress and strain field near the welded zone of the connections. It is found that the welded zone is subjected to multiaxial nonproportional loading during strong ground motion and the elastoplastic stress-strain field of the welded zone is three-dimensional. Then, using the correlation of the Fatemi-Socie (FS parameter versus fatigue life obtained by the experimental crack initiation fatigue data of the structural steel weldment subjected to multiaxial loading, the refined evaluation approach of fatigue crack initiation life is developed based on the equivalent plastic strain at fatigue critical position of beam end seams of crucial welded connections when the steel frame is subjected to the strong earthquake excitation.

Connecting Life Span Development with the Sociology of the Life Course: A New Direction.

Science.gov (United States)

Gilleard, Chris; Higgs, Paul

2016-04-01

The life course has become a topic of growing interest within the social sciences. Attempts to link this sub-discipline with life span developmental psychology have been called for but with little sign of success. In this paper, we seek to address three interlinked issues concerning the potential for a more productive interchange between life course sociology and life span psychology. The first is to try to account for the failure of these two sub-disciplines to achieve any deepening engagement with each other, despite the long-expressed desirability of that goal; the second is to draw attention to the scope for enriching the sociology of the life course through Erik Erikson's model of life span development; and the last is the potential for linking Eriksonian theory with current debates within mainstream sociology about the processes involved in 'individualisation' and 'self-reflexivity' as an alternative entry point to bring together these two fields of work.

Development of Gis Tool for the Solution of Minimum Spanning Tree Problem using Prim's Algorithm

Science.gov (United States)

Dutta, S.; Patra, D.; Shankar, H.; Alok Verma, P.

2014-11-01

minimum spanning tree (MST) of a connected, undirected and weighted network is a tree of that network consisting of all its nodes and the sum of weights of all its edges is minimum among all such possible spanning trees of the same network. In this study, we have developed a new GIS tool using most commonly known rudimentary algorithm called Prim's algorithm to construct the minimum spanning tree of a connected, undirected and weighted road network. This algorithm is based on the weight (adjacency) matrix of a weighted network and helps to solve complex network MST problem easily, efficiently and effectively. The selection of the appropriate algorithm is very essential otherwise it will be very hard to get an optimal result. In case of Road Transportation Network, it is very essential to find the optimal results by considering all the necessary points based on cost factor (time or distance). This paper is based on solving the Minimum Spanning Tree (MST) problem of a road network by finding it's minimum span by considering all the important network junction point. GIS technology is usually used to solve the network related problems like the optimal path problem, travelling salesman problem, vehicle routing problems, location-allocation problems etc. Therefore, in this study we have developed a customized GIS tool using Python script in ArcGIS software for the solution of MST problem for a Road Transportation Network of Dehradun city by considering distance and time as the impedance (cost) factors. It has a number of advantages like the users do not need a greater knowledge of the subject as the tool is user-friendly and that allows to access information varied and adapted the needs of the users. This GIS tool for MST can be applied for a nationwide plan called Prime Minister Gram Sadak Yojana in India to provide optimal all weather road connectivity to unconnected villages (points). This tool is also useful for constructing highways or railways spanning several

Span Restoration in Optical Networks with Limited Wavelength Conversion

DEFF Research Database (Denmark)

Ruepp, Sarah Renée; Buron, Jakob Due; Andriolli, N

2007-01-01

Next generation optical networks provide functionalities to dynamically provision and recover connections, while emerging technologies allow for the conversion between wavelengths. These devices are however expensive and hence it is likely that only few are deployed throughout the network...... converter-saving wavelength assignment in GMPLS networks. The converter saving property of the Suggested Vector is particularly desirable in span restoration, where the pre-failure path stubs have to be merged to the restoration path at the failure-adjacent nodes. In order to avoid wavelength conversion....... Furthermore, we describe different scenarios to extend the suggested vector wavelength assignment scheme to multi-domain networks with focus on span restoration....

Linking and Cutting Spanning Trees

Directory of Open Access Journals (Sweden)

Luís M. S. Russo

2018-04-01

Full Text Available We consider the problem of uniformly generating a spanning tree for an undirected connected graph. This process is useful for computing statistics, namely for phylogenetic trees. We describe a Markov chain for producing these trees. For cycle graphs, we prove that this approach significantly outperforms existing algorithms. For general graphs, experimental results show that the chain converges quickly. This yields an efficient algorithm due to the use of proper fast data structures. To obtain the mixing time of the chain we describe a coupling, which we analyze for cycle graphs and simulate for other graphs.

A Comparison of the Cluster-Span Threshold and the Union of Shortest Paths as Objective Thresholds of EEG Functional Connectivity Networks from Beta Activity in Alzhaimer’s Disease

OpenAIRE

Smith, K; Abasolo, Daniel Emilio; Escudero, J

2016-01-01

The Cluster-Span Threshold (CST) is a recently introduced unbiased threshold for functional connectivity networks. This binarisation technique offers a natural trade-off of sparsity and density of information by balancing the ratio of closed to open triples in the network topology. Here we present findings comparing it with the Union of Shortest Paths (USP), another recently proposed objective method. We analyse standard network metrics of binarised networks for sensitivity to clinical Alzhei...

Friendship in childhood and adulthood: lessons across the life span.

Science.gov (United States)

Sherman, A M; de Vries, B; Lansford, J E

2000-01-01

Friendship occupies an important place in the growing body of literature in child development and gerontological research. As such, it may be useful for researchers from both fields to consider what can be learned from work carried out in each tradition. Therefore, we present a selected review of topics in friendship research across the life span. Through discussion of the value of friendship, the development of friendship, challenges to friendship, the gendered nature of friendship, and the connection between friends and family, points of commonality and contrast are identified. We conclude by presenting possible avenues for future investigation for researchers interested in friendship at any point in the life span.

Individual Differences in Digit Span, Susceptibility to Proactive Interference, and Aptitude/Achievement Test Scores.

Science.gov (United States)

Dempster, Frank N.; Cooney, John B.

1982-01-01

Individual differences in digit span, susceptibility to proactive interference, and various aptitude/achievement test scores were investigated in two experiments with college students. Results indicated that digit span was strongly correlated with aptitude/achievement scores, but did not indicate that susceptibility to proactive interference…

E-commercspan>e in China and Germany: a Sino-German comparative analysis

NARCIS (Netherlands)

Purnhagen, K.

2012-01-01

The ways to approach the regulation of e-commercspan>e markets are in the focus of discussion both in China and Germany. While a general need for regulation is undisputed in both countries, the scope, means and aims regulation differ. The Chinese e-commercspan>e regulation is based on strong governmental

Correspondence between spanning trees and the Ising model on a square lattice

Science.gov (United States)

Viswanathan, G. M.

2017-06-01

An important problem in statistical physics concerns the fascinating connections between partition functions of lattice models studied in equilibrium statistical mechanics on the one hand and graph theoretical enumeration problems on the other hand. We investigate the nature of the relationship between the number of spanning trees and the partition function of the Ising model on the square lattice. The spanning tree generating function T (z ) gives the spanning tree constant when evaluated at z =1 , while giving the lattice green function when differentiated. It is known that for the infinite square lattice the partition function Z (K ) of the Ising model evaluated at the critical temperature K =Kc is related to T (1 ) . Here we show that this idea in fact generalizes to all real temperatures. We prove that [Z(K ) s e c h 2 K ] 2=k exp[T (k )] , where k =2 tanh(2 K )s e c h (2 K ) . The identical Mahler measure connects the two seemingly disparate quantities T (z ) and Z (K ) . In turn, the Mahler measure is determined by the random walk structure function. Finally, we show that the the above correspondence does not generalize in a straightforward manner to nonplanar lattices.

Observation of an octave-spanning supercontinuum in the mid-infrared using ultrafast cascaded nonlinearities

DEFF Research Database (Denmark)

Bache, Morten; Liu, Xing; Zhou, Binbin

2014-01-01

An octave-spanning mid-IR supercontinuum is observed experimentally using ultrafast cascaded nonlinearities in an LiInS2 quadratic nonlinear crystal pumped with 70 fs energetic mid-IR pulses and cut for strongly phase-mismatched second-harmonic generation. ©OSA 2014.......An octave-spanning mid-IR supercontinuum is observed experimentally using ultrafast cascaded nonlinearities in an LiInS2 quadratic nonlinear crystal pumped with 70 fs energetic mid-IR pulses and cut for strongly phase-mismatched second-harmonic generation. ©OSA 2014....

Analytical investigation of bidirectional ductile diaphragms in multi-span bridges

Science.gov (United States)

Wei, Xiaone; Bruneau, Michel

2018-04-01

In the AASHTO Guide Specifications for Seismic Bridge Design Provisions, ductile diaphragms are identified as Permissible Earthquake-Resisting Elements (EREs), designed to help resist seismic loads applied in the transverse direction of bridges. When adding longitudinal ductile diaphragms, a bidirectional ductile diaphragm system is created that can address seismic excitations acting along both the bridge's longitudinal and transverse axes. This paper investigates bidirectional ductile diaphragms with Buckling Restrained Braces (BRBs) in straight multi-span bridge with simply supported floating spans. The flexibility of the substructures in the transverse and longitudinal direction of the bridge is considered. Design procedures for the bidirectional ductile diaphragms are first proposed. An analytical model of the example bridge with bidirectional ductile diaphragms, designed based on the proposed methodology, is then built in SAP2000. Pushover and nonlinear time history analyses are performed on the bridge model, and corresponding results are presented. The effect of changing the longitudinal stiffness of the bidirectional ductile diaphragms in the end spans connecting to the abutment is also investigated, in order to better understand the impact on the bridge's dynamic performance.

A computational study of whole-brain connectivity in resting state and task fMRI

Science.gov (United States)

Goparaju, Balaji; Rana, Kunjan D.; Calabro, Finnegan J.; Vaina, Lucia Maria

2014-01-01

Background We compared the functional brain connectivity produced during resting-state in which subjects were not actively engaged in a task with that produced while they actively performed a visual motion task (task-state). Material/Methods In this paper we employed graph-theoretical measures and network statistics in novel ways to compare, in the same group of human subjects, functional brain connectivity during resting-state fMRI with brain connectivity during performance of a high level visual task. We performed a whole-brain connectivity analysis to compare network statistics in resting and task states among anatomically defined Brodmann areas to investigate how brain networks spanning the cortex changed when subjects were engaged in task performance. Results In the resting state, we found strong connectivity among the posterior cingulate cortex (PCC), precuneus, medial prefrontal cortex (MPFC), lateral parietal cortex, and hippocampal formation, consistent with previous reports of the default mode network (DMN). The connections among these areas were strengthened while subjects actively performed an event-related visual motion task, indicating a continued and strong engagement of the DMN during task processing. Regional measures such as degree (number of connections) and betweenness centrality (number of shortest paths), showed that task performance induces stronger inter-regional connections, leading to a denser processing network, but that this does not imply a more efficient system as shown by the integration measures such as path length and global efficiency, and from global measures such as small-worldness. Conclusions In spite of the maintenance of connectivity and the “hub-like” behavior of areas, our results suggest that the network paths may be rerouted when performing the task condition. PMID:24947491

Resting-State Network Topology Differentiates Task Signals across the Adult Life Span.

Science.gov (United States)

Chan, Micaela Y; Alhazmi, Fahd H; Park, Denise C; Savalia, Neil K; Wig, Gagan S

2017-03-08

Brain network connectivity differs across individuals. For example, older adults exhibit less segregated resting-state subnetworks relative to younger adults (Chan et al., 2014). It has been hypothesized that individual differences in network connectivity impact the recruitment of brain areas during task execution. While recent studies have described the spatial overlap between resting-state functional correlation (RSFC) subnetworks and task-evoked activity, it is unclear whether individual variations in the connectivity pattern of a brain area (topology) relates to its activity during task execution. We report data from 238 cognitively normal participants (humans), sampled across the adult life span (20-89 years), to reveal that RSFC-based network organization systematically relates to the recruitment of brain areas across two functionally distinct tasks (visual and semantic). The functional activity of brain areas (network nodes) were characterized according to their patterns of RSFC: nodes with relatively greater connections to nodes in their own functional system ("non-connector" nodes) exhibited greater activity than nodes with relatively greater connections to nodes in other systems ("connector" nodes). This "activation selectivity" was specific to those brain systems that were central to each of the tasks. Increasing age was accompanied by less differentiated network topology and a corresponding reduction in activation selectivity (or differentiation) across relevant network nodes. The results provide evidence that connectional topology of brain areas quantified at rest relates to the functional activity of those areas during task. Based on these findings, we propose a novel network-based theory for previous reports of the "dedifferentiation" in brain activity observed in aging. SIGNIFICANCE STATEMENT Similar to other real-world networks, the organization of brain networks impacts their function. As brain network connectivity patterns differ across

On the holonomy of the Coulomb connection over manifolds with boundary

International Nuclear Information System (INIS)

Gryc, William E.

2008-01-01

Narasimhan and Ramadas [Commun. Math. Phys. 67, 121 (1979)] showed that the restricted holonomy group of the Coulomb connection is dense in the connected component of the identity of the gauge group when one considers the product principal bundle S 3 xSU(2)→S 3 . Instead of a base manifold S 3 , we consider here a base manifold of dimension n≥2 with a boundary and use Dirichlet boundary conditions on connections as defined by Marini [Commun. Pure Appl. Math. 45, 1015 (1992)]. A key step in the method of Narasimhan and Ramadas consisted in showing that the linear space spanned by the curvature form at one specially chosen connection is dense in the holonomy Lie algebra with respect to an appropriate Sobolev norm. Our objective is to explore the effect of the presence of a boundary on this construction of the holonomy Lie algebra. Fixing appropriate Sobolev norms, it will be shown that the space spanned, linearly, by the curvature form at any one connection is never dense in the holonomy Lie algebra. In contrast, the linear space spanned by the curvature form and its first commutators at the flat connection is dense and, in the C ∞ category, is in fact the entire holonomy Lie algebra. The former, negative, theorem is proven for a general principle bundle over M, while the latter, positive, theorem is proven only for a product bundle over the closure of a bounded open subset of R n . Our technique for proving the absence of density consists in showing that the linear space spanned by the curvature form at one point is contained in the kernel of a linear map consisting of a third order differential operator, followed by a restriction operation at the boundary; this mapping is determined by the mean curvature of the boundary

Boundary Spanning

DEFF Research Database (Denmark)

Zølner, Mette

The paper explores how locals span boundaries between corporate and local levels. The aim is to better comprehend potentialities and challenges when MNCs draws on locals’ culture specific knowledge. The study is based on an in-depth, interpretive case study of boundary spanning by local actors in...... approach with pattern matching is a way to shed light on the tacit local knowledge that organizational actors cannot articulate and that an exclusively inductive research is not likely to unveil....

Long Span Bridges in Scandinavia

DEFF Research Database (Denmark)

Gimsing, Niels Jørgen

1998-01-01

The first Scandinavian bridge with a span of more than 500 m was the Lillebælt Suspension Bridge opened to traffic in 1970.Art the end of the 20th century the longest span of any European bridge is found in the Storebælt East Bridge with a main span of 1624 m. Also the third longest span in Europe...... is found in Scandinavia - the 1210 m span of the Höga Kusten Bridge in Sweden.The Kvarnsund Bridge in Norway was at the completion in 1991 the longest cable-stayed bridge in the world, and the span of 530 m is still thge longest for cable-stayed bridges in concrete. The Øresund Bridge with its sapn of 490...

Ancestral telomere shortening: a countdown that will increase mean life span?

Science.gov (United States)

Hertzog, Radu G

2006-01-01

Like cells, all mammals have a limited life span. Among cells there are a few exceptions (e.g., immortal cells), among mammals not, even if some of them live longer. Many in vitro and in vivo studies support the consensus that telomere length is strongly correlated with life span. At the somatic cellular level, long telomeres have been associated with longer life span. A different situation can be seen in immortal cells, such as cancer, germ and stem cells, where telomeres are maintained by telomerase, a specialized reverse transcriptase that is involved in synthesis of telomeres. Irrespective of telomere length, if telomerase is active, telomeres can be maintained at a sufficient length to ensure cell survival. To the contrary, telomeres shorten progressively with each cell division and when a critical telomere length (Hayflick limit) is reached, the cells undergo senescence and subsequently apoptosis. In mammals, those with the longest telomeres (e.g., mice) have the shortest life span. Furthermore, the shorter the mean telomere length, the longer the mean life span, as observed in humans (10-14 kpb) and bowhead-whales (undetermined telomere length), which have the longest mean life span among mammals. Over the past centuries, human average life span has increased. The hypothesis presented here suggests that this continual increase in the mean life span could be due to a decrease of mean telomere length over the last hundreds years. Actually, the life span is not directly influenced by length of telomeres, but rather by telomere length - dependent gene expression pattern. According to Greider, "rather than average telomere length, it is the shortest telomere length that makes the biggest difference to a cell". In the context of fast-growing global elderly population due to increase in life expectancy, it also seem to be an age related increase in cancer incidence. Nevertheless, extending healthy life span could depend on how good cells achieve, during the

Young Skilled Deaf Readers Have an Enhanced Perceptual Span in Reading.

Science.gov (United States)

Bélanger, Nathalie N; Lee, Michelle; Schotter, Elizabeth R

2017-04-27

Recently, Bélanger, Slattery, Mayberry and Rayner (2012) showed, using the moving window paradigm, that profoundly deaf adults have a wider perceptual span during reading relative to hearing adults matched on reading level. This difference might be related to the fact that deaf adults allocate more visual attention to simple stimuli in the parafovea (Bavelier, Dye & Hauser, 2006). Importantly, this reorganization of visual attention in deaf individuals is already manifesting in deaf children (Dye, Hauser & Bavelier, 2009). This leads to questions about the time course of the emergence of an enhanced perceptual span (which is under attentional control; Rayner, 2014; Miellet, O'Donnell, & Sereno, 2009) in young deaf readers. The present research addressed this question by comparing the perceptual spans of young deaf readers (age 7-15) and young hearing children (age 7-15). Young deaf readers, like deaf adults, were found to have a wider perceptual span relative to their hearing peers matched on reading level, suggesting that strong and early reorganization of visual attention in deaf individuals goes beyond the processing of simple visual stimuli and emerges into more cognitively complex tasks, such as reading.

Investigation into Methods for Predicting Connection Temperatures

Directory of Open Access Journals (Sweden)

K. Anderson

2009-01-01

Full Text Available The mechanical response of connections in fire is largely based on material strength degradation and the interactions between the various components of the connection. In order to predict connection performance in fire, temperature profiles must initially be established in order to evaluate the material strength degradation over time. This paper examines two current methods for predicting connection temperatures: The percentage method, where connection temperatures are calculated as a percentage of the adjacent beam lower-flange, mid-span temperatures; and the lumped capacitance method, based on the lumped mass of the connection. Results from the percentage method do not correlate well with experimental results, whereas the lumped capacitance method shows much better agreement with average connection temperatures. A 3D finite element heat transfer model was also created in Abaqus, and showed good correlation with experimental results. 

Riesz basis for strongly continuous groups.

NARCIS (Netherlands)

Zwart, Heiko J.

Given a Hilbert space and the generator of a strongly continuous group on this Hilbert space. If the eigenvalues of the generator have a uniform gap, and if the span of the corresponding eigenvectors is dense, then these eigenvectors form a Riesz basis (or unconditional basis) of the Hilbert space.

Advance features in the SPAN and SPAN/XRF gamma ray and X ray spectrum analysis software

International Nuclear Information System (INIS)

Wang Liyu

1998-01-01

This paper describes the advanced techniques, integral peak background, experimental peak shape and complex peak shape, which have been used successfully in the software packages SPAN and SPAN/XRF to process gamma ray and X ray spectra from HPGe and Si(Li) detector. Main features of SPAN and SPAN/XRF are also described. The software runs on PC and has convenient graphical capabilities and a powerful user interface. (author)

Estimation of Height from Arm Span in 6-11 Years Children in Odisha, India

Directory of Open Access Journals (Sweden)

Snigdha Prava Mishra

2017-10-01

Full Text Available Introduction: Standing height is an important anthropometric parameter to track longitudinal growth, to estimate body fatness and to calculate energy requirement. Measurement of height may be difficult in children who cannot stand. Aim: To establish regression equation for estimation of height from arm span in children. To check comparative relevancy of this equation with fixed height-to-arm span ratio (HAR for estimation of height. Materials and Methods: A cross-sectional study was conducted with 6-11 years school children (n=1465, Boys=774, Girls=691 in state of Odisha, India. Height was measured by portable stadiometer and arm span was measured by fiberglass measuring tape to nearest 0.1 cm. Pearson correlation and regression analysis was carried out between height and arm span data. p<0.05 (two tail was considered statistically significant. Results: Mean height and arm span in boys (124.16±8.74 cm and 125.57±10.43 cm respectively was significantly more (p<0.001 than height and arm span in girls (121.18±10.37 cm and 121.50±11.68 cm respectively. Mean HAR was 0.9942±0.0279. Correlation between height and arm span in boys was r = 0.94 (p<0.001 and in girls was r = 0.96 (p<0.001. Overall correlation coefficient was r = 0.95 (p<0.001. Regression equation for estimation of height from arm span was established: Height (cm = 0.8192 * arm span (cm + 21.46. Conclusion: Height in children of 6-11 years showed strong positive correlation with arm span. Regression equation established from this study can be used to estimate height from arm span. This estimation is more reliable than estimation of height from HAR.

Aerodynamic problems of cable-stayed bridges spanning over one thousand meters

Institute of Scientific and Technical Information of China (English)

Chen Airong; Ma Rujin; Wang Dalei

2009-01-01

Tbe elongating of cable-stayed bridge brings a series of aerodynamic problems. First of all, geometric nonlin-ear effect of extreme long cable is much more significant for cable-stayed bridge spanning over one thousand meters. Lat-eral static wind load will generate additional displacement of long cables, which causes the decrease of supporting rigidi-ty of the whole bridge and the change of dynamic properties. Wind load, being the controlling load in the design of ca-hie-stayed bridge, is a critical problem and needs to be solved. Meanwhile, research on suitable system between pylon and deck indicates fixed-fixed connection system is an effective way for improvement performance of cable-stayed bridges under longitudinal wind load. In order to obtain aerodynamic parameters of cable-stayed bridge spanning over one thou-sand meters, identification method for flutter derivatives of full bridge aero-elastic model is developed in this paper. Furthermore, vortex induced vibration and Reynolds number effect are detailed discussed.

RGFinder: a system for determining semantically related genes using GO graph minimum spanning tree.

Science.gov (United States)

Taha, Kamal

2015-01-01

Biologists often need to know the set S' of genes that are the most functionally and semantically related to a given set S of genes. For determining the set S', most current gene similarity measures overlook the structural dependencies among the Gene Ontology (GO) terms annotating the set S, which may lead to erroneous results. We introduce in this paper a biological search engine called RGFinder that considers the structural dependencies among GO terms by employing the concept of existence dependency. RGFinder assigns a weight to each edge in GO graph to represent the degree of relatedness between the two GO terms connected by the edge. The value of the weight is determined based on the following factors: 1) type of the relation represented by the edge (e.g., an "is-a" relation is assigned a different weight than a "part-of" relation), 2) the functional relationship between the two GO terms connected by the edge, and 3) the string-substring relationship between the names of the two GO terms connected by the edge. RGFinder then constructs a minimum spanning tree of GO graph based on these weights. In the framework of RGFinder, the set S' is annotated to the GO terms located at the lowest convergences of the subtree of the minimum spanning tree that passes through the GO terms annotating set S. We evaluated RGFinder experimentally and compared it with four gene set enrichment systems. Results showed marked improvement.

Determinantal spanning forests on planar graphs

OpenAIRE

Kenyon, Richard

2017-01-01

We generalize the uniform spanning tree to construct a family of determinantal measures on essential spanning forests on periodic planar graphs in which every component tree is bi-infinite. Like the uniform spanning tree, these measures arise naturally from the laplacian on the graph. More generally these results hold for the "massive" laplacian determinant which counts rooted spanning forests with weight $M$ per finite component. These measures typically have a form of conformal invariance, ...

Thermodynamics and life span estimation

International Nuclear Information System (INIS)

Kuddusi, Lütfullah

2015-01-01

In this study, the life span of people living in seven regions of Turkey is estimated by applying the first and second laws of thermodynamics to the human body. The people living in different regions of Turkey have different food habits. The first and second laws of thermodynamics are used to calculate the entropy generation rate per unit mass of a human due to the food habits. The lifetime entropy generation per unit mass of a human was previously found statistically. The two entropy generations, lifetime entropy generation and entropy generation rate, enable one to determine the life span of people living in seven regions of Turkey with different food habits. In order to estimate the life span, some statistics of Turkish Statistical Institute regarding the food habits of the people living in seven regions of Turkey are used. The life spans of people that live in Central Anatolia and Eastern Anatolia regions are the longest and shortest, respectively. Generally, the following inequality regarding the life span of people living in seven regions of Turkey is found: Eastern Anatolia < Southeast Anatolia < Black Sea < Mediterranean < Marmara < Aegean < Central Anatolia. - Highlights: • The first and second laws of thermodynamics are applied to the human body. • The entropy generation of a human due to his food habits is determined. • The life span of Turks is estimated by using the entropy generation method. • Food habits of a human have effect on his life span

Reading Ability and Memory Span: Long-Term Memory Contributions to Span for Good and Poor Readers.

Science.gov (United States)

McDougall, Sine J. P.; Donohoe, Rachael

2002-01-01

Investigates the extent to which differences in memory span for good and poor readers can be explained by differences in a long-term memory component to span as well as by differences in short-term memory processes. Discusses the nature of the interrelationships between memory span, reading and measures of phonological awareness. (SG)

Life Span Developmental Approach

Directory of Open Access Journals (Sweden)

Ali Eryilmaz

2011-03-01

Full Text Available The Life Span Developmental Approach examines development of individuals which occurs from birth to death. Life span developmental approach is a multi-disciplinary approach related with disciplines like psychology, psychiatry, sociology, anthropology and geriatrics that indicates the fact that development is not completed in adulthood, it continues during the life course. Development is a complex process that consists of dying and death. This approach carefully investigates the development of individuals with respect to developmental stages. This developmental approach suggests that scientific disciplines should not explain developmental facts only with age changes. Along with aging, cognitive, biological, and socioemotional development throughout life should also be considered to provide a reasonable and acceptable context, guideposts, and reasonable expectations for the person. There are three important subjects whom life span developmental approach deals with. These are nature vs nurture, continuity vs discontinuity, and change vs stability. Researchers using life span developmental approach gather and produce knowledge on these three most important domains of individual development with their unique scientific methodology.

Connected feedback vertex set in planar graphs

NARCIS (Netherlands)

Grigoriev, Alexander; Sitters, René

2010-01-01

We study the problem of finding a minimum tree spanning the faces of a given planar graph. We show that a constant factor approximation follows from the unconnected version if the minimum degree is 3. Moreover, we present a polynomial time approximation scheme for both the connected and unconnected

Spanning Trees whose Stems have a Bounded Number of Branch Vertices

Directory of Open Access Journals (Sweden)

Yan Zheng

2016-08-01

Full Text Available Let T be a tree, a vertex of degree one and a vertex of degree at least three is called a leaf and a branch vertex, respectively. The set of leaves of T is denoted by Leaf(T. The subtree T − Leaf(T of T is called the stem of T and denoted by Stem(T. In this paper, we give two sufficient conditions for a connected graph to have a spanning tree whose stem has a bounded number of branch vertices, and these conditions are best possible.

When a Parent Is Away: Promoting Strong Parent-Child Connections during Parental Absence

Science.gov (United States)

Yeary, Julia; Zoll, Sally; Reschke, Kathy

2012-01-01

How does a parent stay connected with an infant or toddler during a prolonged separation? Research has shown how important early connections are for child development. When a parent is not present physically, there are strategies that military parents have been using to keep a parent and child connected, promoting mindfulness. Because infants and…

Indoor Positioning Using Nonparametric Belief Propagation Based on Spanning Trees

Directory of Open Access Journals (Sweden)

Savic Vladimir

2010-01-01

Full Text Available Nonparametric belief propagation (NBP is one of the best-known methods for cooperative localization in sensor networks. It is capable of providing information about location estimation with appropriate uncertainty and to accommodate non-Gaussian distance measurement errors. However, the accuracy of NBP is questionable in loopy networks. Therefore, in this paper, we propose a novel approach, NBP based on spanning trees (NBP-ST created by breadth first search (BFS method. In addition, we propose a reliable indoor model based on obtained measurements in our lab. According to our simulation results, NBP-ST performs better than NBP in terms of accuracy and communication cost in the networks with high connectivity (i.e., highly loopy networks. Furthermore, the computational and communication costs are nearly constant with respect to the transmission radius. However, the drawbacks of proposed method are a little bit higher computational cost and poor performance in low-connected networks.

Some studies on structural planning of long-span cable stayed bridge; Choshikan shachokyo no kozo keikaku ni kansuru 2,3 no kosatsu

Energy Technology Data Exchange (ETDEWEB)

Endo, T. [NKK Corp., Tokyo (Japan)

1997-06-20

Feasibility of cabled-stayed bridges with 1000m-grade spans is discussed while re-examining the plan for constructing a Great Tatara Bridge to connect Honshu and Shikoku, Japan, and in this process various tasks and questions are isolated. Some which will be problems in designing the new bridge structure are taken up, including the load-bearing capability of the bridge as a whole, vibration of long cables, resistance to long-period earthquakes, and accuracy management during the construction work. Findings are stated below. A cable-stayed bridge is not significantly different from a suspension bridge and is sufficiently feasible until the span exceeds 1500m. When the span is longer, however, the bridge beam cross section needs be designed very prudently in view of the great axial force and wind load to be imposed on it. Effective for the assurance of load-bearing capability for a long-span cabled-stayed bridge is a structure in which load is elastically confined in the direction of the bridge axis. In connection with vibration damping for very long cables, it is verified that a new dimpled cable suits the purpose of suppressing wind load from increasing without reduction in damping effect. 28 refs., 23 figs., 7 tabs.

The Connect Effect Building Strong Personal, Professional, and Virtual Networks

CERN Document Server

Dulworth, Michael

2008-01-01

Entrepreneur and executive development expert Mike Dulworth's THE CONNECT EFFECT provides readers with a simple framework and practical tools for developing that crucial competitive advantage: a high-quality personal, professional/organizational and virtual network.

The relationship between visual-spatial and auditory-verbal working memory span in Senegalese and Ugandan children.

Directory of Open Access Journals (Sweden)

Michael J Boivin

Full Text Available BACKGROUND: Using the Kaufman Assessment Battery for Children (K-ABC Conant et al. (1999 observed that visual and auditory working memory (WM span were independent in both younger and older children from DR Congo, but related in older American children and in Lao children. The present study evaluated whether visual and auditory WM span were independent in Ugandan and Senegalese children. METHOD: In a linear regression analysis we used visual (Spatial Memory, Hand Movements and auditory (Number Recall WM along with education and physical development (weight/height as predictors. The predicted variable in this analysis was Word Order, which is a verbal memory task that has both visual and auditory memory components. RESULTS: Both the younger (8.5 yrs Ugandan children had auditory memory span (Number Recall that was strongly predictive of Word Order performance. For both the younger and older groups of Senegalese children, only visual WM span (Spatial Memory was strongly predictive of Word Order. Number Recall was not significantly predictive of Word Order in either age group. CONCLUSIONS: It is possible that greater literacy from more schooling for the Ugandan age groups mediated their greater degree of interdependence between auditory and verbal WM. Our findings support those of Conant et al., who observed in their cross-cultural comparisons that stronger education seemed to enhance the dominance of the phonological-auditory processing loop for WM.

The relationship between visual-spatial and auditory-verbal working memory span in Senegalese and Ugandan children.

Science.gov (United States)

Boivin, Michael J; Bangirana, Paul; Shaffer, Rebecca C; Smith, Rebecca C

2010-01-27

Using the Kaufman Assessment Battery for Children (K-ABC) Conant et al. (1999) observed that visual and auditory working memory (WM) span were independent in both younger and older children from DR Congo, but related in older American children and in Lao children. The present study evaluated whether visual and auditory WM span were independent in Ugandan and Senegalese children. In a linear regression analysis we used visual (Spatial Memory, Hand Movements) and auditory (Number Recall) WM along with education and physical development (weight/height) as predictors. The predicted variable in this analysis was Word Order, which is a verbal memory task that has both visual and auditory memory components. Both the younger (8.5 yrs) Ugandan children had auditory memory span (Number Recall) that was strongly predictive of Word Order performance. For both the younger and older groups of Senegalese children, only visual WM span (Spatial Memory) was strongly predictive of Word Order. Number Recall was not significantly predictive of Word Order in either age group. It is possible that greater literacy from more schooling for the Ugandan age groups mediated their greater degree of interdependence between auditory and verbal WM. Our findings support those of Conant et al., who observed in their cross-cultural comparisons that stronger education seemed to enhance the dominance of the phonological-auditory processing loop for WM.

Use of the Wechsler Adult Intelligence Scale Digit Span subtest for malingering detection: a meta-analytic review.

Science.gov (United States)

Jasinski, Lindsey J; Berry, David T R; Shandera, Anni L; Clark, Jessica A

2011-03-01

Twenty-four studies utilizing the Wechsler Adult Intelligence Scale (WAIS) Digit Span subtest--either the Reliable Digit Span (RDS) or Age-Corrected Scaled Score (DS-ACSS) variant--for malingering detection were meta-analytically reviewed to evaluate their effectiveness in detecting malingered neurocognitive dysfunction. RDS and DS-ACSS effectively discriminated between honest responders and dissimulators, with average weighted effect sizes of 1.34 and 1.08, respectively. No significant differences were found between RDS and DS-ACSS. Similarly, no differences were found between the Digit Span subtest from the WAIS or Wechsler Memory Scale (WMS). Strong specificity and moderate sensitivity were observed, and optimal cutting scores are recommended.

Connected Colourings of Complete Graphs and Hypergraphs

OpenAIRE

Leader, Imre; Tan, Ta Sheng

2014-01-01

Gallai's colouring theorem states that if the edges of a complete graph are 3-coloured, with each colour class forming a connected (spanning) subgraph, then there is a triangle that has all 3 colours. What happens for more colours: if we $k$-colour the edges of the complete graph, with each colour class connected, how many of the $\\binom{k}{3}$ triples of colours must appear as triangles? In this note we show that the `obvious' conjecture, namely that there are always at least $\\binom{k-1}{2}...

Working memory and inhibitory control across the life span: Intrusion errors in the Reading Span Test.

Science.gov (United States)

Robert, Christelle; Borella, Erika; Fagot, Delphine; Lecerf, Thierry; de Ribaupierre, Anik

2009-04-01

The aim of this study was to examine to what extent inhibitory control and working memory capacity are related across the life span. Intrusion errors committed by children and younger and older adults were investigated in two versions of the Reading Span Test. In Experiment 1, a mixed Reading Span Test with items of various list lengths was administered. Older adults and children recalled fewer correct words and produced more intrusions than did young adults. Also, age-related differences were found in the type of intrusions committed. In Experiment 2, an adaptive Reading Span Test was administered, in which the list length of items was adapted to each individual's working memory capacity. Age groups differed neither on correct recall nor on the rate of intrusions, but they differed on the type of intrusions. Altogether, these findings indicate that the availability of attentional resources influences the efficiency of inhibition across the life span.

Life Span Developmental Approach

OpenAIRE

Ali Eryilmaz

2011-01-01

The Life Span Developmental Approach examines development of individuals which occurs from birth to death. Life span developmental approach is a multi-disciplinary approach related with disciplines like psychology, psychiatry, sociology, anthropology and geriatrics that indicates the fact that development is not completed in adulthood, it continues during the life course. Development is a complex process that consists of dying and death. This approach carefully investigates the development of...

Short proofs of strong normalization

OpenAIRE

Wojdyga, Aleksander

2008-01-01

This paper presents simple, syntactic strong normalization proofs for the simply-typed lambda-calculus and the polymorphic lambda-calculus (system F) with the full set of logical connectives, and all the permutative reductions. The normalization proofs use translations of terms and types to systems, for which strong normalization property is known.

Weight concern across the life-span: relationship to self-esteem and feminist identity.

Science.gov (United States)

Tiggemann, M; Stevens, C

1999-07-01

The aim of this study was to investigate the correlates of weight concern across the life-span. Questionnaires assessing weight concern, self-esteem, and feminist attitudes were completed in their homes by 180 women aged between 18 and 60 years. It was found that there was a negative relationship between weight concern and self-esteem for 30 to 49-year-old women, but not for younger or older women. A similar pattern held for feminist attitudes. Among 30 to 49-year-old women, a strong feminist orientation related to a lesser concern with weight. It was concluded that the meaning and experience of body weight and size change across the life-span.

Technical research and development of long-spanned bridges; Chodai kyoryo no gijutsu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Sakai, F.; Yamanaka, M.; Ogawa, K.; Mizukami, Y.; Kano, J.; Watanabe, K. [Kawasaki Heavy Industries, Ltd., Kobe (Japan)

1996-10-15

Outlined herein is technical development of long-spanned bridges represented by suspension and cable-stayed bridges. The design of long-spanned bridges requires theoretical analysis of flexibility in which balance after they are deformed by load is taken into consideration. The matrix finite displacement analysis program is developed for optimizing cable-stayed bridge designs and determining suspension bridge shapes as the new major functions. The analysis program, named KASTAN, is also developed for stress analysis of the structure details. A wind tunnel for structure designs is installed to analyze resistance to wind. A number of experiments have been carried out by the tunnel for the designs of segment, main tower and overall bridge models. The means of controlling wind-caused vibration include hydraulic dampers, mass dampers, and combination of high damping rubber and spacer. Cable-stayed bridges are highly flexible, their types being selected by tower height and shape, span ratio and shape of the main beam, and cable position. These bridges constructed by the company include the S-shaped ones whose main beams are supported by cables suspended by two towers of different height, and the others with H-shape towers of high columns which are connected to each other by horizontal beams. 11 refs., 15 figs.

Embedding relations connected with strong approximation of Fourier ...

Indian Academy of Sciences (India)

ing only odd functions and a set of functions defined via the strong means of Fourier series of odd continuous functions. We establish an improvement of a recent theorem of Le and Zhou [Math. Inequal. Appl. 11(4) (2008) 749–756] which is a generalization of Tikhonov's results [Anal. Math. 31 (2005) 183–194]. We also ...

Age Differences in Memory Span

Science.gov (United States)

Chi, Michelene T. H.

1977-01-01

Three experiments were conducted to determine processes underlying age differences in the level of recall in a memory-span task. Five-year-olds recalled fewer items than adults in memory-span tasks involving both familiar and unfamiliar faces, even though the use of rehearsal and recoding strategies was minimized for adults. (MS)

Dissociable Changes of Frontal and Parietal Cortices in Inherent Functional Flexibility across the Human Life Span.

Science.gov (United States)

Yin, Dazhi; Liu, Wenjing; Zeljic, Kristina; Wang, Zhiwei; Lv, Qian; Fan, Mingxia; Cheng, Wenhong; Wang, Zheng

2016-09-28

Extensive evidence suggests that frontoparietal regions can dynamically update their pattern of functional connectivity, supporting cognitive control and adaptive implementation of task demands. However, it is largely unknown whether this flexibly functional reconfiguration is intrinsic and occurs even in the absence of overt tasks. Based on recent advances in dynamics of resting-state functional resonance imaging (fMRI), we propose a probabilistic framework in which dynamic reconfiguration of intrinsic functional connectivity between each brain region and others can be represented as a probability distribution. A complexity measurement (i.e., entropy) was used to quantify functional flexibility, which characterizes heterogeneous connectivity between a particular region and others over time. Following this framework, we identified both functionally flexible and specialized regions over the human life span (112 healthy subjects from 13 to 76 years old). Across brainwide regions, we found regions showing high flexibility mainly in the higher-order association cortex, such as the lateral prefrontal cortex (LPFC), lateral parietal cortex, and lateral temporal lobules. In contrast, visual, auditory, and sensory areas exhibited low flexibility. Furthermore, we observed that flexibility of the right LPFC improved during maturation and reduced due to normal aging, with the opposite occurring for the left lateral parietal cortex. Our findings reveal dissociable changes of frontal and parietal cortices over the life span in terms of inherent functional flexibility. This study not only provides a new framework to quantify the spatiotemporal behavior of spontaneous brain activity, but also sheds light on the organizational principle behind changes in brain function across the human life span. Recent neuroscientific research has demonstrated that the human capability of adaptive task control is primarily the result of the flexible operation of frontal brain networks. However

Timber beams loaded perpendicular to grain by multiple connections

NARCIS (Netherlands)

Leijten, A.J.M.; Schoenmakers, J.C.M.

2014-01-01

In timber structures, beams which are loaded perpendicular to grain by connections along the span may fail by splitting, resulting in the collapse of the beam. In the past, empirical, semi-empirical and fracture mechanical models have been developed aiming at predicting the splitting failure load.

London SPAN version 4 parameter file format

International Nuclear Information System (INIS)

2004-06-01

Powernext SA is a Multilateral Trading Facility in charge of managing the French power exchange through an optional and anonymous organised trading system. Powernext SA collaborates with the clearing organization LCH.Clearnet SA to secure and facilitate the transactions. The French Standard Portfolio Analysis of Risk (SPAN) is a system used by LCH.Clearnet to calculate the initial margins from and for its clearing members. SPAN is a computerized system which calculates the impact of several possible variations of rates and volatility on by-product portfolios. The initial margin call is equal to the maximum probable loss calculated by the system. This document contains details of the format of the London SPAN version 4 parameter file. This file contains all the parameters and risk arrays required to calculate SPAN margins. London SPAN Version 4 is an upgrade from Version 3, which is also known as LME SPAN. This document contains the full revised file specification, highlighting the changes from Version 3 to Version 4

A Depth-Adjustment Deployment Algorithm Based on Two-Dimensional Convex Hull and Spanning Tree for Underwater Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Peng Jiang

2016-07-01

Full Text Available Most of the existing node depth-adjustment deployment algorithms for underwater wireless sensor networks (UWSNs just consider how to optimize network coverage and connectivity rate. However, these literatures don’t discuss full network connectivity, while optimization of network energy efficiency and network reliability are vital topics for UWSN deployment. Therefore, in this study, a depth-adjustment deployment algorithm based on two-dimensional (2D convex hull and spanning tree (NDACS for UWSNs is proposed. First, the proposed algorithm uses the geometric characteristics of a 2D convex hull and empty circle to find the optimal location of a sleep node and activate it, minimizes the network coverage overlaps of the 2D plane, and then increases the coverage rate until the first layer coverage threshold is reached. Second, the sink node acts as a root node of all active nodes on the 2D convex hull and then forms a small spanning tree gradually. Finally, the depth-adjustment strategy based on time marker is used to achieve the three-dimensional overall network deployment. Compared with existing depth-adjustment deployment algorithms, the simulation results show that the NDACS algorithm can maintain full network connectivity with high network coverage rate, as well as improved network average node degree, thus increasing network reliability.

Analyzing systemic risk using non-linear marginal expected shortfall and its minimum spanning tree

Science.gov (United States)

Song, Jae Wook; Ko, Bonggyun; Chang, Woojin

2018-02-01

The aim of this paper is to propose a new theoretical framework for analyzing the systemic risk using the marginal expected shortfall (MES) and its correlation-based minimum spanning tree (MST). At first, we develop two parametric models of MES with their closed-form solutions based on the Capital Asset Pricing Model. Our models are derived from the non-symmetric quadratic form, which allows them to consolidate the non-linear relationship between the stock and market returns. Secondly, we discover the evidences related to the utility of our models and the possible association in between the non-linear relationship and the emergence of severe systemic risk by considering the US financial system as a benchmark. In this context, the evolution of MES also can be regarded as a reasonable proxy of systemic risk. Lastly, we analyze the structural properties of the systemic risk using the MST based on the computed series of MES. The topology of MST conveys the presence of sectoral clustering and strong co-movements of systemic risk leaded by few hubs during the crisis. Specifically, we discover that the Depositories are the majority sector leading the connections during the Non-Crisis period, whereas the Broker-Dealers are majority during the Crisis period.

Comparison on the heat requirements of a four-span greenhouse with a melting snow system and a single-span greenhouse

International Nuclear Information System (INIS)

Furuno, S.; Sase, S.; Ishii, M.

2004-01-01

The heat requirements were measured and compared between a four-span greenhouse with a melting snow system and a typical single-span greenhouse with no melting snow system. Generally, single-span greenhouses require no melting snow system because snow drops off naturally from the roofs by gravity. The results for the four-span greenhouse showed that the provided heat by a heater for melting snow increased with an increase in snowfall, and there was a high correlation between them. The heat requirement per unit floor area of the four-span greenhouse was slightly less than that of the single-span greenhouse. This suggests that the decrease in heat requirement for internal air because of the larger floor/surface area ratio of the four-span greenhouse was more than the increase in heat requirement for melting snow. The measured heat requirement of the four-span greenhouse with the melting snow system was equal to the estimated heat load based on a common calculation procedure. On the other hand, that of the single-span greenhouse was slightly smaller than the estimated heat load. These suggest that the estimated heat load based on the common calculation procedure was slightly overestimated and larger than the actual heat requirement excluding the heat for the melting snow in snowy area. This is likely due to the fact that the parameters in the common calculation procedure were determined under the condition of larger net radiation than that in snowy area

Linking crowding, visual span, and reading.

Science.gov (United States)

He, Yingchen; Legge, Gordon E

2017-09-01

The visual span is hypothesized to be a sensory bottleneck on reading speed with crowding thought to be the major sensory factor limiting the size of the visual span. This proposed linkage between crowding, visual span, and reading speed is challenged by the finding that training to read crowded letters reduced crowding but did not improve reading speed (Chung, 2007). Here, we examined two properties of letter-recognition training that may influence the transfer to improved reading: the spatial arrangement of training stimuli and the presence of flankers. Three groups of nine young adults were trained with different configurations of letter stimuli at 10° in the lower visual field: a flanked-local group (flanked letters localized at one position), a flanked-distributed group (flanked letters distributed across different horizontal locations), and an isolated-distributed group (isolated and distributed letters). We found that distributed training, but not the presence of flankers, appears to be necessary for the training benefit to transfer to increased reading speed. Localized training may have biased attention to one specific, small area in the visual field, thereby failing to improve reading. We conclude that the visual span represents a sensory bottleneck on reading, but there may also be an attentional bottleneck. Reducing the impact of crowding can enlarge the visual span and can potentially facilitate reading, but not when adverse attentional bias is present. Our results clarify the association between crowding, visual span, and reading.

Visual Attention Span and Optometric Conditions: Is There a Connection between a Poor VAS and an Optometric Diagnosis?

Science.gov (United States)

Carroll, Emily

2004-01-01

This paper investigates whether there is a correlation between a poor Visual Attention Span (VAS) and the child's optometric status. Convergence excess impacts most upon a male achieving a VAS-3 more than 75 per cent of the time. Fifty per cent of females with eye-teaming problems are unlikely to achieve a VAS-3 more than 25 per cent of the time.…

Examining the relationships between span of control and manager job and unit performance outcomes.

Science.gov (United States)

Wong, Carol A; Elliott-Miller, Pat; Laschinger, Heather; Cuddihy, Michael; Meyer, Raquel M; Keatings, Margaret; Burnett, Camille; Szudy, Natalie

2015-03-01

Our aim was to examine the combination of frontline manager (FLM) personal characteristics and span of control (SOC) on their job and unit performance outcomes. Healthcare downsizing and reform have contributed to larger spans for FLMs in Canadian hospitals and increased concerns about manager workload. Despite a heightened awareness of SOC issues among decision makers, there is limited empirical evidence related to the effects of SOC on outcomes. A non-experimental predictive survey design was used to examine FLM SOC in 14 Canadian academic hospitals. Managers (n = 121) completed an online survey of work characteristics and The Ottawa Hospital (TOH) SOC tool. Unit turnover data were collected from organisational databases. The combination of SOC and core self-evaluation significantly predicted role overload, work control and job satisfaction, but only SOC predicted unit adverse outcomes and neither significantly predicted unit turnover. The findings contribute to an understanding of connections between the combination of SOC and core self-evaluation and manager job and unit performance outcomes. Organisational strategies to create manageable FLM SOC are essential to ensure exemplary job and unit outcomes. Core self-evaluation is a personality characteristic that may enhance manager performance in the face of high spans of control. © 2013 John Wiley & Sons Ltd.

Detailed free span assessment for Mexilhao flow lines

Energy Technology Data Exchange (ETDEWEB)

Pereira, Antonio; Franco, Luciano; Eigbe, Uwa; BomfimSilva, Carlos [INTECSEA, Houston, TX (United States); Escudero, Carlos [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

2009-07-01

The subsea gas production system of Mexilhao Field SPS-35, Santos Basin, offshore Brazil, is composed basically of two rigid 12.75 inches production flow lines approximately 21 km long installed in a fairly rough seabed. During the basic design, the free span assessment was performed considering the maximum allowable free span length determined by the response model proposed by DNV-RP-F105. This approach resulted in a large number of predicted free span requiring corrections, leading to a higher capital cost for the project. In this sense, a detailed free span VIV fatigue assessment was proposed, considering multi-spans and multi-mode effects and also the post lay survey data. The assessment followed the DNV-RP-F105 recommendations for multi-spans and multi-mode effects, using Finite Element Analysis to determine the natural frequencies, mode shapes and corresponding stresses associated with the mode shapes. The assessment was performed in three stages, the first during the detailed design as part of the bottom roughness analysis using the expected residual pipelay tension. The second stage was performed after pipelay, considering the post-lay survey data, where the actual requirements for span correction were determined. Actual pipelay tension was used and seabed soil stiffness adjusted in the model to match the as-laid pipeline profile obtained from the survey data. The first and second stage assessments are seamlessly automated to speed up the evaluation process and allow for quick response in the field, which was important to keep the construction vessel time minimized. The third stage was performed once the corrections of the spans were made and the purpose was to confirm that the new pipeline configuration along the supported spans had sufficient fatigue life for the temporary and operational phases. For the assessment of all three stages, the probability of occurrence and directionality of the near bottom current was considered to improve prediction of the

Free span burial inspection pig. Phase B

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-04-01

the length of exposure in the remaining 8 kilometre of the pipeline. This is probably because there are too few sections with fully buried pipeline to provide a good estimate of the radioactive content of the sediment here. The FSB-technology identified all pipeline field joints because they have no concrete cover. It is assumed, that 75% loss of concrete in a 3-m long section can be detected, if the lost concrete has been removed from the pipe's neighbourhood. With the FSB-technology offshore pipelines can be inspected during storm and strong currents where exposure and free spans can be longer than seen during calm weather. Application of the FSB-technology will contribute to safety in energy supplies. The instrumentation can also be used for other inspection topics because of its robust and sensitive detector. The FSB-pig can be used for supersensitive leakage inspection of oil pipelines. Demonstration runs on a 20-inch oil pipeline indicate that leaks down to 1 liter per hour can be detected on a pipeline carrying 1500 m{sup 3} oil per hour. The instrumentation is also well suited for inspection of oil pipelines for the presence of NORM (Natural Occurring Radioactive Materials) and it can most probably also be configured for inspection of gas pipelines because of its special aluminium housing of the detector. Such inspection may be valuable before pipeline retirement.

L-fuzzy/span> fixed points theorems for L-fuzzy/span> mappings via βℱL-admissible pair.

Science.gov (United States)

Rashid, Maliha; Azam, Akbar; Mehmood, Nayyar

2014-01-01

We define the concept of βℱL-admissible for a pair of L-fuzzy/span> mappings and establish the existence of common L-fuzzy/span> fixed point theorem. Our result generalizes some useful results in the literature. We provide an example to support our result.

Sexual conflict, life span, and aging.

Science.gov (United States)

Adler, Margo I; Bonduriansky, Russell

2014-06-17

The potential for sexual conflict to influence the evolution of life span and aging has been recognized for more than a decade, and recent work also suggests that variation in life span and aging can influence sexually antagonistic coevolution. However, empirical exploration of these ideas is only beginning. Here, we provide an overview of the ideas and evidence linking inter- and intralocus sexual conflicts with life span and aging. We aim to clarify the conceptual basis of this research program, examine the current state of knowledge, and suggest key questions for further investigation. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.

Spanning forests and the vector bundle Laplacian

OpenAIRE

Kenyon, Richard

2011-01-01

The classical matrix-tree theorem relates the determinant of the combinatorial Laplacian on a graph to the number of spanning trees. We generalize this result to Laplacians on one- and two-dimensional vector bundles, giving a combinatorial interpretation of their determinants in terms of so-called cycle rooted spanning forests (CRSFs). We construct natural measures on CRSFs for which the edges form a determinantal process. ¶ This theory gives a natural generalization of the spanning tre...

Optimisation for offshore wind farm cable connection layout using adaptive particle swarm optimisation minimum spanning tree method

DEFF Research Database (Denmark)

Hou, Peng; Hu, Weihao; Chen, Zhe

2016-01-01

operational requirement and this constraint should be considered during the MST formulation process. Hence, traditional MST algorithm cannot ensure a minimal cable investment layout. In this paper, a new method to optimize the offshore wind farm cable connection layout is presented. The algorithm...... with the optimized cable connection layout. The proposed method is compared with the MST and Dynamic MST (DMST) methods and simulation results show the effectiveness of the proposed method....

Validation of the human odor span task: effects of nicotine.

Science.gov (United States)

MacQueen, David A; Drobes, David J

2017-10-01

Amongst non-smokers, nicotine generally enhances performance on tasks of attention, with limited effect on working memory. In contrast, nicotine has been shown to produce robust enhancements of working memory in non-humans. To address this gap, the present study investigated the effects of nicotine on the performance of non-smokers on a cognitive battery which included a working memory task reverse-translated from use with rodents (the odor span task, OST). Nicotine has been reported to enhance OST performance in rats and the present study assessed whether this effect generalizes to human performance. Thirty non-smokers were tested on three occasions after consuming either placebo, 2 mg, or 4 mg nicotine gum. On each occasion, participants completed a battery of clinical and experimental tasks of working memory and attention. Nicotine was associated with dose-dependent enhancements in sustained attention, as evidenced by increased hit accuracy on the rapid visual information processing (RVIP) task. However, nicotine failed to produce main effects on OST performance or on alternative measures of working memory (digit span, spatial span, letter-number sequencing, 2-back) or attention (digits forward, 0-back). Interestingly, enhancement of RVIP performance occurred concomitant to significant reductions in self-reported attention/concentration. Human OST performance was significantly related to N-back performance, and as in rodents, OST accuracy declined with increasing memory load. Given the similarity of human and rodent OST performance under baseline conditions and the strong association between OST and visual 0-back accuracy, the OST may be particular useful in the study of conditions characterized by inattention.

Span efficiency in hawkmoths.

Science.gov (United States)

Henningsson, Per; Bomphrey, Richard J

2013-07-06

Flight in animals is the result of aerodynamic forces generated as flight muscles drive the wings through air. Aerial performance is therefore limited by the efficiency with which momentum is imparted to the air, a property that can be measured using modern techniques. We measured the induced flow fields around six hawkmoth species flying tethered in a wind tunnel to assess span efficiency, ei, and from these measurements, determined the morphological and kinematic characters that predict efficient flight. The species were selected to represent a range in wingspan from 40 to 110 mm (2.75 times) and in mass from 0.2 to 1.5 g (7.5 times) but they were similar in their overall shape and their ecology. From high spatio-temporal resolution quantitative wake images, we extracted time-resolved downwash distributions behind the hawkmoths, calculating instantaneous values of ei throughout the wingbeat cycle as well as multi-wingbeat averages. Span efficiency correlated positively with normalized lift and negatively with advance ratio. Average span efficiencies for the moths ranged from 0.31 to 0.60 showing that the standard generic value of 0.83 used in previous studies of animal flight is not a suitable approximation of aerodynamic performance in insects.

A very strong difference property for semisimple compact connected lie groups

Science.gov (United States)

Shtern, A. I.

2011-06-01

Let G be a topological group. For a function f: G → ℝ and h ∈ G, the difference function Δ h f is defined by the rule Δ h f( x) = f( xh) - f( x) ( x ∈ G). A function H: G → ℝ is said to be additive if it satisfies the Cauchy functional equation H( x + y) = H( x) + H( y) for every x, y ∈ G. A class F of real-valued functions defined on G is said to have the difference property if, for every function f: G → ℝ satisfying Δ h f ∈ F for each h ∈ G, there is an additive function H such that f - H ∈ F. Erdős' conjecture claiming that the class of continuous functions on ℝ has the difference property was proved by N. G. de Bruijn; later on, F. W. Carroll and F. S. Koehl obtained a similar result for compact Abelian groups and, under the additional assumption that the other one-sided difference function ∇ h f defined by ∇ h f( x) = f( xh) - f( x) ( x ∈ G, h ∈ G) is measurable for any h ∈ G, also for noncommutative compact metric groups. In the present paper, we consider a narrower class of groups, namely, the family of semisimple compact connected Lie groups. It turns out that these groups admit a significantly stronger difference property. Namely, if a function f: G → ℝ on a semisimple compact connected Lie group has continuous difference functions Δ h f for any h ∈ G (without the additional assumption concerning the measurability of the functions of the form ∇ h f), then f is automatically continuous, and no nontrivial additive function of the form H is needed. Some applications are indicated, including difference theorems for homogeneous spaces of compact connected Lie groups.

Malingering in Toxic Exposure. Classification Accuracy of Reliable Digit Span and WAIS-III Digit Span Scaled Scores

Science.gov (United States)

Greve, Kevin W.; Springer, Steven; Bianchini, Kevin J.; Black, F. William; Heinly, Matthew T.; Love, Jeffrey M.; Swift, Douglas A.; Ciota, Megan A.

2007-01-01

This study examined the sensitivity and false-positive error rate of reliable digit span (RDS) and the WAIS-III Digit Span (DS) scaled score in persons alleging toxic exposure and determined whether error rates differed from published rates in traumatic brain injury (TBI) and chronic pain (CP). Data were obtained from the files of 123 persons…

Signal Enhancement with Variable Span Linear Filters

DEFF Research Database (Denmark)

Benesty, Jacob; Christensen, Mads Græsbøll; Jensen, Jesper Rindom

This book introduces readers to the novel concept of variable span speech enhancement filters, and demonstrates how it can be used for effective noise reduction in various ways. Further, the book provides the accompanying Matlab code, allowing readers to easily implement the main ideas discussed....... Variable span filters combine the ideas of optimal linear filters with those of subspace methods, as they involve the joint diagonalization of the correlation matrices of the desired signal and the noise. The book shows how some well-known filter designs, e.g. the minimum distortion, maximum signal......-to-noise ratio, Wiener, and tradeoff filters (including their new generalizations) can be obtained using the variable span filter framework. It then illustrates how the variable span filters can be applied in various contexts, namely in single-channel STFT-based enhancement, in multichannel enhancement in both...

Electrode spanning with partial tripolar stimulation mode in cochlear implants.

Science.gov (United States)

Wu, Ching-Chih; Luo, Xin

2014-12-01

The perceptual effects of electrode spanning (i.e., the use of nonadjacent return electrodes) in partial tripolar (pTP) mode were tested on a main electrode EL8 in five cochlear implant (CI) users. Current focusing was controlled by σ (the ratio of current returned within the cochlea), and current steering was controlled by α (the ratio of current returned to the basal electrode). Experiment 1 tested whether asymmetric spanning with α = 0.5 can create additional channels around standard pTP stimuli. It was found that in general, apical spanning (i.e., returning current to EL6 rather than EL7) elicited a pitch between those of standard pTP stimuli on main electrodes EL8 and EL9, while basal spanning (i.e., returning current to EL10 rather than EL9) elicited a pitch between those of standard pTP stimuli on main electrodes EL7 and EL8. The pitch increase caused by apical spanning was more salient than the pitch decrease caused by basal spanning. To replace the standard pTP channel on the main electrode EL8 when EL7 or EL9 is defective, experiment 2 tested asymmetrically spanned pTP stimuli with various α, and experiment 3 tested symmetrically spanned pTP stimuli with various σ. The results showed that pitch increased with decreasing α in asymmetric spanning, or with increasing σ in symmetric spanning. Apical spanning with α around 0.69 and basal spanning with α around 0.38 may both elicit a similar pitch as the standard pTP stimulus. With the same σ, the symmetrically spanned pTP stimulus was higher in pitch than the standard pTP stimulus. A smaller σ was thus required for symmetric spanning to match the pitch of the standard pTP stimulus. In summary, electrode spanning is an effective field-shaping technique that is useful for adding spectral channels and handling defective electrodes with CIs.

The impact of emotional intelligent leadership on staff nurse empowerment: the moderating effect of span of control.

Science.gov (United States)

Lucas, Victoria; Laschinger, Heather K Spence; Wong, Carol A

2008-11-01

To test a model linking nurses' perceptions of their nurse manager's emotionally intelligent leadership style and nurses' structural empowerment, and the impact of nurse manager span of control (number of direct reports) on the emotional intelligence/empowerment relationship. Hospital restructuring in the 1990s resulted in a dramatic reduction in nurse manager positions, yet nurse managers are critical to empowering nurses for professional practice. A descriptive correlational survey design was used to test the hypothesized model in two community hospitals in Ontario. Two hundred and three nurses from two hospitals returned useable questionnaires (68% response rate). Span of control was a significant moderator of the relationship between nurses perceptions of their managers' emotionally intelligent behaviour and feelings of workplace empowerment. The results suggest that even managers with strong emotional intelligence may not be able to empower their staff if their span of control is large. Every effort must be made to ensure that managers have reasonable spans of control that allow them to develop and use the leadership skill necessary for empowering their staff to practice to the full scope of their professional role.

Self-Esteem Development across the Life Span: A Longitudinal Study with a Large Sample from Germany

Science.gov (United States)

Orth, Ulrich; Maes, Jürgen; Schmitt, Manfred

2015-01-01

The authors examined the development of self-esteem across the life span. Data came from a German longitudinal study with 3 assessments across 4 years of a sample of 2,509 individuals ages 14 to 89 years. The self-esteem measure used showed strong measurement invariance across assessments and birth cohorts. Latent growth curve analyses indicated…

Data-Parallel Mesh Connected Components Labeling and Analysis

Energy Technology Data Exchange (ETDEWEB)

Harrison, Cyrus; Childs, Hank; Gaither, Kelly

2011-04-10

We present a data-parallel algorithm for identifying and labeling the connected sub-meshes within a domain-decomposed 3D mesh. The identification task is challenging in a distributed-memory parallel setting because connectivity is transitive and the cells composing each sub-mesh may span many or all processors. Our algorithm employs a multi-stage application of the Union-find algorithm and a spatial partitioning scheme to efficiently merge information across processors and produce a global labeling of connected sub-meshes. Marking each vertex with its corresponding sub-mesh label allows us to isolate mesh features based on topology, enabling new analysis capabilities. We briefly discuss two specific applications of the algorithm and present results from a weak scaling study. We demonstrate the algorithm at concurrency levels up to 2197 cores and analyze meshes containing up to 68 billion cells.

The SPAN cookbook: A practical guide to accessing SPAN

Science.gov (United States)

Mason, Stephanie; Tencati, Ronald D.; Stern, David M.; Capps, Kimberly D.; Dorman, Gary; Peters, David J.

1990-01-01

This is a manual for remote users who wish to send electronic mail messages from the Space Physics Analysis Network (SPAN) to scientific colleagues on other computer networks and vice versa. In several instances more than one gateway has been included for the same network. Users are provided with an introduction to each network listed with helpful details about accessing the system and mail syntax examples. Also included is information on file transfers, remote logins, and help telephone numbers.

Radiation effects on life span in Caenorhabditis elegans

International Nuclear Information System (INIS)

Johnson, T.E.; Hartman, P.S.

1988-01-01

Wild-type and radiation-sensitive (Rad) mutants of Caenorhabditis elegans were irradiated using a 137 Cs source (2.7 krads/min.) at several developmental stages and subsequently monitored for life span. Acute doses of radiation ranged from 1 krad to 300 krads. All stages required doses above 100 krads to reduce mean life span. Dauers and third stage larvae were more sensitive, and 8-day-old adults were the most resistant. Occasional statistically significant but nonrepeatable increases in survival were observed after intermediate levels of irradiation (10-30 krads). Unirradiated rad-4 and rad-7 had life spans similar to wild-type; all others had a significant reduction in survival. The mutants were about as sensitive as wild-type to the effects of ionizing radiation including occasional moderate life span extensions at intermediate doses. We conclude that the moderate life span extensions sometimes observed after irradiation are likely to be mediated by a means other than the induction of DNA repair enzymes

Investigating the visual span in comparative search: the effects of task difficulty and divided attention.

Science.gov (United States)

Pomplun, M; Reingold, E M; Shen, J

2001-09-01

In three experiments, participants' visual span was measured in a comparative visual search task in which they had to detect a local match or mismatch between two displays presented side by side. Experiment 1 manipulated the difficulty of the comparative visual search task by contrasting a mismatch detection task with a substantially more difficult match detection task. In Experiment 2, participants were tested in a single-task condition involving only the visual task and a dual-task condition in which they concurrently performed an auditory task. Finally, in Experiment 3, participants performed two dual-task conditions, which differed in the difficulty of the concurrent auditory task. Both the comparative search task difficulty (Experiment 1) and the divided attention manipulation (Experiments 2 and 3) produced strong effects on visual span size.

23 CFR 650.809 - Movable span bridges.

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Movable span bridges. 650.809 Section 650.809 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.809 Movable span bridges. A fixed bridge...

Signal enhancement with variable span linear filters

CERN Document Server

Benesty, Jacob; Jensen, Jesper R

2016-01-01

This book introduces readers to the novel concept of variable span speech enhancement filters, and demonstrates how it can be used for effective noise reduction in various ways. Further, the book provides the accompanying Matlab code, allowing readers to easily implement the main ideas discussed. Variable span filters combine the ideas of optimal linear filters with those of subspace methods, as they involve the joint diagonalization of the correlation matrices of the desired signal and the noise. The book shows how some well-known filter designs, e.g. the minimum distortion, maximum signal-to-noise ratio, Wiener, and tradeoff filters (including their new generalizations) can be obtained using the variable span filter framework. It then illustrates how the variable span filters can be applied in various contexts, namely in single-channel STFT-based enhancement, in multichannel enhancement in both the time and STFT domains, and, lastly, in time-domain binaural enhancement. In these contexts, the properties of ...

Connective capacity in water governance practices: The meaning of trust and boundary spanning for integrated performance

NARCIS (Netherlands)

J. Edelenbos (Jurian); I.F. van Meerkerk (Ingmar)

2015-01-01

markdownabstract__Abstract__ This article deals with water governance to face institutional fragmentation in water management practices. In this holistic approach the connective capacity with domains, levels, scales, organizations and actors is emphasized. Recent literature and empirical research

Reliability and validity of Web-SPAN, a web-based method for assessing weight status, diet and physical activity in youth.

Science.gov (United States)

Storey, K E; McCargar, L J

2012-02-01

Web-based surveys are becoming increasing popular. The present study aimed to assess the reliability and validity of the Web-Survey of Physical Activity and Nutrition (Web-SPAN) for self-report of height and weight, diet and physical activity by youth. School children aged 11-15years (grades 7-9; n=459) participated in the school-based research (boys, n=225; girls, n=233; mean age, 12.8years). Students completed Web-SPAN (self-administered) twice and participated in on-site school assessments [height, weight, 3-day food/pedometer record, Physical Activity Questionnaire for Older Children (PAQ-C), shuttle run]. Intraclass (ICC) and Pearson's correlation coefficients and paired samples t-tests were used to assess the test-retest reliability of Web-SPAN and to compare Web-SPAN with the on-site assessments. Test-retest reliability for height (ICC=0.90), weight (ICC=0.98) and the PAQ-C (ICC=0.79) were highly correlated, whereas correlations for nutrients were not as strong (ICC=0.37-0.64). There were no differences between Web-SPAN times 1 and 2 for height and weight, although there were differences for the PAQ-C and most nutrients. Web-SPAN was strongly correlated with the on-site assessments, including height (ICC=0.88), weight (ICC=0.93) and the PAQ-C (ICC=0.70). Mean differences for height and the PAQ-C were not significant, whereas mean differences for weight were significant resulting in an underestimation of being overweight/obesity prevalence (84% agreement). Correlations for nutrients were in the range 0.24-0.40; mean differences were small but generally significantly different. Correlations were weak between the web-based PAQ-C and 3-day pedometer record (r=0.28) and 20-m shuttle run (r=0.28). Web-SPAN is a time- and cost-effective method that can be used to assess the diet and physical activity status of youth in large cross-sectional studies and to assess group trends (weight status). © 2011 The Authors. Journal of Human Nutrition and Dietetics © 2011 The

Effect of habitat preference on frond life span in three Cyathea tree ferns

Science.gov (United States)

Chiu, Tzu Yun; Wang, Hsiang Hua; Lun Kuo, Yao; Kume, Tomonori

2013-04-01

It has been reported that plants living in various geographical areas had different physiological forms, as factors of microenvironment have strong impacts on physiological characters. However, the physiological characters of fronds have been scarcely reported in ferns. In this study, we investigated physiological differences in response to the habitat preference in the three tree ferns in northeast Taiwan, Cyathea lepifera, C. spinulosa, and C. podophylla, prefer to open site, edge of forest, and interior forest, respectively. The canopy openness above the individuals of C. lepifera, C. spinulosa and C. podophylla were 29.2 ± 14.10 , 7.0 ± 3.07 and 5.0 ± 2.24 %, respectively. Among three species, C. podophylla had the longest frond life span (13.0 ± 4.12 months) than the two others (C. lepifera (6.8 ± 1.29 months) and C. spinulosa (7.3 ±1.35 months). Our result supported the general patterns that shade intolerant species have a shorter leaf life span than shade tolerant species. The maximum net CO2 assimilation of C. lepifera, C. spinulosa and C. podophylla were 11.46 ± 1.34, 8.27 ± 0.69, and 6.34 ± 0.54 μmol CO2 m-2 s-1, respectively. As well, C. lepifera had the highest photosynthetic light saturation point (LSP), while C. podophylla had the lowest LSP among these three tree ferns. These suggested that C. lepifera could be more efficient for capturing and utilizing light resources under the larger canopy openness condition than the other two species. We also found that frond C : N ratio were positively correlated with frond life span among species. C. podophylla, with the longest frond life span, had the highest frond C : N ratio (22.17 ± 1.95), which was followed by C. spinulosa (18.58 ± 1.37) and C. lepifera (18.68 ± 2.63) with shorter frond life span. The results were consistent to the theory that the fronds and leaves of shade intolerant species have high photosynthetic abilities with low C : N ratio. Key words: Canopy openness, frond life span

Wavelet Correlation Coefficient of 'strongly correlated' financial time series

OpenAIRE

Razdan, Ashok

2003-01-01

In this paper we use wavelet concepts to show that correlation coefficient between two financial data's is not constant but varies with scale from high correlation value to strongly anti-correlation value This studies is important because correlation coefficient is used to quantify degree of independence between two variables. In econophysics correlation coefficient forms important input to evolve hierarchial tree and minimum spanning tree of financial data.

STATISTICAL STUDY OF STRONG AND EXTREME GEOMAGNETIC DISTURBANCES AND SOLAR CYCLE CHARACTERISTICS

International Nuclear Information System (INIS)

Kilpua, E. K. J.; Olspert, N.; Grigorievskiy, A.; Käpylä, M. J.; Tanskanen, E. I.; Pelt, J.; Miyahara, H.; Kataoka, R.; Liu, Y. D.

2015-01-01

We study the relation between strong and extreme geomagnetic storms and solar cycle characteristics. The analysis uses an extensive geomagnetic index AA data set spanning over 150 yr complemented by the Kakioka magnetometer recordings. We apply Pearson correlation statistics and estimate the significance of the correlation with a bootstrapping technique. We show that the correlation between the storm occurrence and the strength of the solar cycle decreases from a clear positive correlation with increasing storm magnitude toward a negligible relationship. Hence, the quieter Sun can also launch superstorms that may lead to significant societal and economic impact. Our results show that while weaker storms occur most frequently in the declining phase, the stronger storms have the tendency to occur near solar maximum. Our analysis suggests that the most extreme solar eruptions do not have a direct connection between the solar large-scale dynamo-generated magnetic field, but are rather associated with smaller-scale dynamo and resulting turbulent magnetic fields. The phase distributions of sunspots and storms becoming increasingly in phase with increasing storm strength, on the other hand, may indicate that the extreme storms are related to the toroidal component of the solar large-scale field

STATISTICAL STUDY OF STRONG AND EXTREME GEOMAGNETIC DISTURBANCES AND SOLAR CYCLE CHARACTERISTICS

Energy Technology Data Exchange (ETDEWEB)

Kilpua, E. K. J. [Department of Physics, University Helsinki (Finland); Olspert, N.; Grigorievskiy, A.; Käpylä, M. J.; Tanskanen, E. I.; Pelt, J. [ReSoLVE Centre of Excellence, Department of Computer Science, P.O. Box 15400, FI-00076 Aalto Univeristy (Finland); Miyahara, H. [Musashino Art University, 1-736 Ogawa-cho, Kodaira-shi, Tokyo 187-8505 (Japan); Kataoka, R. [National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518 (Japan); Liu, Y. D. [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190 (China)

2015-06-20

We study the relation between strong and extreme geomagnetic storms and solar cycle characteristics. The analysis uses an extensive geomagnetic index AA data set spanning over 150 yr complemented by the Kakioka magnetometer recordings. We apply Pearson correlation statistics and estimate the significance of the correlation with a bootstrapping technique. We show that the correlation between the storm occurrence and the strength of the solar cycle decreases from a clear positive correlation with increasing storm magnitude toward a negligible relationship. Hence, the quieter Sun can also launch superstorms that may lead to significant societal and economic impact. Our results show that while weaker storms occur most frequently in the declining phase, the stronger storms have the tendency to occur near solar maximum. Our analysis suggests that the most extreme solar eruptions do not have a direct connection between the solar large-scale dynamo-generated magnetic field, but are rather associated with smaller-scale dynamo and resulting turbulent magnetic fields. The phase distributions of sunspots and storms becoming increasingly in phase with increasing storm strength, on the other hand, may indicate that the extreme storms are related to the toroidal component of the solar large-scale field.

A Motivational Theory of Life-Span Development

Science.gov (United States)

Heckhausen, Jutta; Wrosch, Carsten; Schulz, Richard

2010-01-01

This article had four goals. First, the authors identified a set of general challenges and questions that a life-span theory of development should address. Second, they presented a comprehensive account of their Motivational Theory of Life-Span Development. They integrated the model of optimization in primary and secondary control and the…

The use of passwords to introduce theconcepts of spanning set and span

Directory of Open Access Journals (Sweden)

Andrea Cárcamo

2017-01-01

Full Text Available The aim of this paper is to present a proposal for teaching linear algebra based on heuristic of emergent models and mathematical modelling. This proposal begins with a problematic situation  related  to  the  creation  and  use  of  secure  passwords,  which  leads  first-year  students  of  engineering  toward  the  construction  of  the  concepts  of  spanning  set  and  span. The  proposal  is  designed  from  the  results  of  the  two  cycles  of  experimentation  teaching, design-based  research,  which  give  evidence  that  allows  students  to  progress  from  a  situation in a real context to the concepts of linear algebra. This proposal, previously adapted, could have similar results when applied to another group of students.

[Genome loses all 5-methylcytosine a life span. How is this connected with accumulation of mutations during aging?].

Science.gov (United States)

Mazin, A L

1993-01-01

The 5-methylcytosine (5mC) content in liver DNA has been determined for rats of different age. The rate of the 5mC loss from DNA is maximal in pre- and neonatal rats, 1.28% of reduction of the 5mC content per day, then it decreases to 0.33% and becomes minimal and constant in adult rats, 0.028% per day. During pregnancy and the first 15 days of postnatal development rat genome loses 49% of all 5mC. Within the next 45 days 15% of 5mC disappears, and during maximal rat life span, about four years, 39% of the genomic 5mC may be lost. Thus, it has been found for the first time that the animal genome loses practically all 5mC residues during the life span. Analysis of the literature data shows that for embryos the rate of the 5mC loss from DNA proves to be higher than that for adult animals by 96 times for mice, 69-for rats and 28-for cows. The rate of embryonal DNA hypomethylation may be inversely proportional to the pregnancy duration of species. In adult animals the rate inversely correlates with their maximal life span and accounts for the 5mC loss from DNA of a mouse by 0.028%, of a rat by 0.024%, of a hamster by 0.007%, of a cow by 0.004% and of a human being by 0.0005% per day. During the entire ontogenesis, the genome of a mouse loses 93% of all 5mC residues, that of a rat-101% and of a cow-88%. The age-dependent loss of 5mC from DNA is also typical for cell lines aging in vitro. It is constant, as a rule, and correlates with the number of cell population doublings (PD). The removal of all 5mC from DNA corresponds to 70-130 PD for human, 40-60 PD-for hamster and 6 PD- for mouse cells. In immortal lines the level of DNA methylation is stable or grows with age. A possible mechanism of an age-related 5mC loss from DNA is discussed. DNA hypomethylation may result from 5mC deamination directly at the moment of replicative DNA methylation and subsequent reparation of the G.T mispairs which leads to accumulation of the 5mC-->T+C substitutions in the genome with each

The business case for connectivity

Science.gov (United States)

Adams, Dennis; Hirschheim, Rudy

1991-01-01

Information systems that provide competitive advantages to organizations can be broadly classified into those that improve the effectiveness of a business function and those that improve the reach of information in the organization. The latter, organizational connectivity systems, can be categorized as intraorganizational and interorganizational systems. Intraorganization systems provide connectivity to function areas within the business, while interorganizational systems support the exchange of business data between independent business units. These system are not confined to a single entity but span organizational boundaries which can be national or international in scope. A series of case studies was undertaken in an effort to better understand the issues and problems associated with providing an increased flow of information within and outside of an organization. Ten issues emerged from this study. In summary, it is necessary for firms to first consider how effective their internal communications systems are before launching projects that tie the organization to external systems.

EU Regulation of E-Commercspan>e A Commentary

NARCIS (Netherlands)

Lodder, A.R.; Murray, A.D.

2017-01-01

For the last twenty years the European Union has been extremely active in the field of e-commercspan>e. This important new book addresses the key pieces of EU legislation in the field of e-commercspan>e, including the E-Commercspan>e Directive, the Services Directive, the Consumer Directive, the General Data

QCD and strongly coupled gauge theories: challenges and perspectives

NARCIS (Netherlands)

Brambilla, N.; Eidelman, S.; Foka, P.; Gardner, S.; Kronfeld, A. S.; Alford, M. G.; Alkofer, R.; Butenschoen, M.; Cohen, T. D.; Erdmenger, J.; Fabbietti, L.; Faber, M.; Goity, J. L.; Ketzer, B.; Lin, H. W.; Llanes-Estrada, F. J.; Meyer, H.; Pakhlov, P.; Pallante, E.; Polikarpov, M. I.; Sazdjian, H.; Schmitt, A.; Snow, W. M.; Vairo, A.; Vogt, R.; Vuorinen, A.; Wittig, H.; Arnold, P.; Christakoglou, P.; Nezza, P. Di; Fodor, Z.; Tormo, X. Garcia i; Höllwieser, R.; Kalwait, A.; Keane, D.; Kiritsis, E.; Mischke, A.; Mizuk, R.; Odyniec, G.; Papadodimas, K.; Pich, A.; Pittau, R.; Qiu, Jian-Wei; Ricciardi, G.; Salgado, C. A.; Schwenzer, K.; Stefanis, N. G.; Hippel, G. M. von; Zakharov, V. I .

2014-01-01

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly-coupled, complex

Larval connectivity studies in the Western Iberian Peninsula

Science.gov (United States)

Dubert, Jesus; Nolasco, Rita; Queiroga, Henrique

2010-05-01

The study of the connectivity between populations is one of the 'hot' applications of numerical models of the ocean circulation. An IBM (Individual Based model) was developed, using Carcinus manenas larvae crab as a model. A set of particles was used as a representation of larvae, in order to study their larval life cycle, including the larval growth, larval mortality (both depending on temperature and salinity), larval dispersal by currents, diel vertical migration, and larval recruitment. The life cycle of every larvae in the ocean, was modeled from zoeae 1 stage to megalopae stage, during typical periods of 30-50 days. Larvae were initialized in 14 estuarine systems of the Atlantic Western Iberian Peninsula, from January to July. In every period, a number of 225 larvae are initialized in everyone of the 14 considered estuaries, with fortynighly periodicity. The larvae evolves during the (variable, depending mainly on temperature) period of growth in the ocean, and when a larvae reach the age for recruit, if it is located in the neighborhood of the considered estuarine systems, the larvae is accounted as a recruited larvae in that place. With this methodology, a connectivity matrix can be computed, acconting for the 225 larvae emitted in every estuary, the number of larvae that reaches the every place. The connectivity matrix depends strongly on the current regime along the Atlantic coast of Iberian Peninsula, and has been calculated for the present circulation, for the period 2001 to 2009, for runs with realistic forcing with NCEP2 and Quikscat (for winds) forcing. The connectivity matrix, have also been calculated for climatological runs. For the present climatological conditions, it is observed the prevalence of southward transport for the period January-July, because the prevalence of Northerly winds along the west coast of IP in the COADS present time climatology. Strong dispersal is observed at the Northern estuaries, during winter with strong loss of

Diferença entre span verbal e visual nos gêneros: estudo piloto Difference between verbal and visual span in genders: pilot study

Directory of Open Access Journals (Sweden)

Mariana Cristina Pedrassa Sagrilo

2012-01-01

Full Text Available OBJETIVO: avaliar a memória de trabalho analisando a capacidade de retenção de estímulos auditivos (span verbal e visuais (span visual e estabelecer a relação com o gênero (masculino e feminino. MÉTODO: participaram deste estudo 20 crianças entre seis anos e cinco meses e sete anos, sendo 10 sujeitos do sexo masculino e 10 sujeitos do sexo feminino. Todos os sujeitos foram submetidos às provas de avaliação do span verbal e visual em ordem direta e inversa. RESULTADOS: apenas na prova de palavras dissílabas com fonologia semelhante e semântica diferente do span verbal, houve variância significante entre os gêneros. As crianças do sexo feminino apresentaram melhor desempenho em relação ao outro gênero, bem como maior capacidade de retenção de palavras dissílabas com fonologia e semântica diferentes. No span visual (ordem direta e inversa as crianças do sexo masculino obtiveram melhor desempenho, apesar de não ter diferenças significantes. Em relação à idade não houve diferença de retenção de estímulos. CONCLUSÃO: as crianças do sexo feminino, neste estudo, apresentaram tendência à melhor desempenho do span verbal e as crianças do sexo masculino tendência a melhor desempenho no span visual. No entanto, o estudo é limitado devido ao reduzido número de participantes na amostra.PURPOSE: to evaluate the working memory analyzing the retention ability of auditory stimuli (verbal span and visual stimuli (visual span, and to establish its relation to gender (male and female. METHOD: 20 subjects - 10 female children and 10 male children - from six and five months to seven years old took part in this study. All subjects were submitted to evaluation tests for both verbal and visual spans in direct and inverse orders. RESULTS: there was a significant variance between genders only in the test involving disyllabic words with phonology similar to and semantics different from verbal span. Female children showed a better

The European legal framework regarding e-commercspan>e

NARCIS (Netherlands)

Schaub, M.Y.

2004-01-01

The year 2000 is a memorable year in the history of e-commercspan>e. This is the year of the so-called 'dot.com shake-out'. The year 2000 is also the year the European Union issued its e-commercspan>e directive. The directive means to regulate but also facilitate e-commercspan>e in the internal market, by laying

Evaluating the efficiency of shortcut span protection

DEFF Research Database (Denmark)

Ruepp, Sarah Renée; Dittmann, Lars; Berger, Michael Stübert

2010-01-01

This paper presents a comparison of various recovery methods in terms of capacity efficiency with the underlying aim of reducing control plane load. In particular, a method where recovery requests are bundled towards the destination (Shortcut Span Protection) is evaluated can compared against tra...... traditional recovery methods. The optimization model is presented and our simulation results show that Shortcut Span Protection uses more capacity than the unbundled related methods, but this is compensated by easier control and management of the recovery actions.......This paper presents a comparison of various recovery methods in terms of capacity efficiency with the underlying aim of reducing control plane load. In particular, a method where recovery requests are bundled towards the destination (Shortcut Span Protection) is evaluated can compared against...

On the cardinality of smallest spanning sets of rings | Boudi ...

African Journals Online (AJOL)

Let R = (R, +, ·) be a ring. Then Z ⊆ R is called spanning if the R-module generated by Z is equal to the ring R. A spanning set Z ⊆ R is called smallest if there is no spanning set of smaller cardinality than Z. It will be shown that the cardinality of a smallest spanning set of a ring R is not always decidable. In particular, a ring R ...

Mitigating the Impact of Nurse Manager Large Spans of Control.

Science.gov (United States)

Simpson, Brenda Baird; Dearmon, Valorie; Graves, Rebecca

Nurse managers are instrumental in achievement of organizational and unit performance goals. Greater spans of control for managers are associated with decreased satisfaction and performance. An interprofessional team measured one organization's nurse manager span of control, providing administrative assistant support and transformational leadership development to nurse managers with the largest spans of control. Nurse manager satisfaction and transformational leadership competency significantly improved following the implementation of large span of control mitigation strategies.

Visual working memory span in adults with cochlear implants: Some preliminary findings

Directory of Open Access Journals (Sweden)

Aaron C. Moberly

2017-12-01

Full Text Available Objective: Neurocognitive functions, specifically verbal working memory (WM, contribute to speech recognition in postlingual adults with cochlear implants (CIs and normal-hearing (NH listener shearing degraded speech. Three hypotheses were tested: (1 WM accuracy as assessed using three visual span measures — digits, objects, and symbols — would correlate with recognition scores for spectrally degraded speech (through a CI or when noise-vocoded; (2 WM accuracy would be best for digit span, intermediate for object span, and lowest for symbol span, due to the increasing cognitive demands across these tasks. Likewise, response times, relating to processing demands, would be shortest for digit span, intermediate for object span, and longest for symbol span; (3 CI users would demonstrate poorer and slower performance than NH peers on WM tasks, as a result of less efficient verbally mediated encoding strategies associated with a period of prolonged auditory deprivation. Methods: Cross-sectional study of 30 postlingually deaf adults with CIs and 34 NH controls. Participants were tested for sentence recognition in quiet (CI users or after noise-vocoding (NH peers, along with WM using visual measures of digit span, object span, and symbol span. Results: Of the three measures of WM, digit span scores alone correlated with sentence recognition for CI users; no correlations were found using these three measures for NH peers. As predicted, WM accuracy (and response times were best (and fastest for digit span, intermediate for object span, and worst (and slowest for symbol span. CI users and NH peers demonstrated equivalent WM accuracy and response time for digit span and object span, and similar response times for symbol span, but contrary to our original predictions, CI users demonstrated better accuracy on symbol span than NH peers. Conclusions: Verbal WM assessed using visual tasks relates weakly to sentence recognition for degraded speech. CI users

The composite complex span: French validation of a short working memory task.

Science.gov (United States)

Gonthier, Corentin; Thomassin, Noémylle; Roulin, Jean-Luc

2016-03-01

Most studies in individual differences in the field of working memory research use complex span tasks to measure working memory capacity. Various complex span tasks based on different materials have been developed, and these tasks have proven both reliable and valid; several complex span tasks are often combined to provide a domain-general estimate of working memory capacity with even better psychometric properties. The present work sought to address two issues. Firstly, having participants perform several full-length complex span tasks in succession makes for a long and tedious procedure. Secondly, few complex span tasks have been translated and validated in French. We constructed a French working memory task labeled the Composite Complex Span (CCS). The CCS includes shortened versions of three classic complex span tasks: the reading span, symmetry span, and operation span. We assessed the psychometric properties of the CCS, including test-retest reliability and convergent validity, with Raven's Advanced Progressive Matrices and with an alpha span task; the CCS demonstrated satisfying qualities in a sample of 1,093 participants. This work provides evidence that shorter versions of classic complex span tasks can yield valid working memory estimates. The materials and normative data for the CCS are also included.

Four forces and spinor connection in general relativity

International Nuclear Information System (INIS)

Lynch, J.T.

1985-01-01

This work is an extension of the recent spinor-connection theory of Szekeres, Cullinan, and Lynch. In that theory, a geometric model for the gravitational and electromagnetic fields was realized by use of both left- and right-connection groups acting on a 4 x 4 spinor tetrad. Here the right-connection group is enlarged in a natural way from a one-parameter to a three-parameter Lie group. This enlargement introduces two extra potential fields which may provide a simple model for the strong and weak fields in curved space-time. A solution to the new field equations is given for a neutral ''pionlike'' particle exhibiting the strong and gravitational fields

Visual-Attentional Span and Lexical ­Decision in Skilled Adult Readers

Science.gov (United States)

Holmes, Virginia M.; Dawson, Georgia

2014-01-01

The goal of the study was to examine the association between visual-attentional span and lexical decision in skilled adult readers. In the span tasks, an array of letters was presented briefly and recognition or production of a single cued letter (partial span) or production of all letters (whole span) was required. Independently of letter…

Examining the locus of age effects on complex span tasks.

Science.gov (United States)

McCabe, Jennifer; Hartman, Marilyn

2003-09-01

To investigate the locus of age effects on complex span tasks, the authors evaluated the contributions of working memory functions and processing speed. Age differences were found in measures of storage capacity, language processing speed, and lower level speed. Statistically controlling for each of these in hierarchical regressions substantially reduced, but did not eliminate, the complex span age effect. Accounting for lower level speed and storage, however, removed essentially the entire age effect, suggesting that both functions play important and independent roles. Additional evidence for the role of storage capacity was the absence of complex span age differences with span size calibrated to individual word span performance. Explanations for age differences based on inhibition and concurrent task performamce were not supported.

WildSpan: mining structured motifs from protein sequences

Directory of Open Access Journals (Sweden)

Chen Chien-Yu

2011-03-01

Full Text Available Abstract Background Automatic extraction of motifs from biological sequences is an important research problem in study of molecular biology. For proteins, it is desired to discover sequence motifs containing a large number of wildcard symbols, as the residues associated with functional sites are usually largely separated in sequences. Discovering such patterns is time-consuming because abundant combinations exist when long gaps (a gap consists of one or more successive wildcards are considered. Mining algorithms often employ constraints to narrow down the search space in order to increase efficiency. However, improper constraint models might degrade the sensitivity and specificity of the motifs discovered by computational methods. We previously proposed a new constraint model to handle large wildcard regions for discovering functional motifs of proteins. The patterns that satisfy the proposed constraint model are called W-patterns. A W-pattern is a structured motif that groups motif symbols into pattern blocks interleaved with large irregular gaps. Considering large gaps reflects the fact that functional residues are not always from a single region of protein sequences, and restricting motif symbols into clusters corresponds to the observation that short motifs are frequently present within protein families. To efficiently discover W-patterns for large-scale sequence annotation and function prediction, this paper first formally introduces the problem to solve and proposes an algorithm named WildSpan (sequential pattern mining across large wildcard regions that incorporates several pruning strategies to largely reduce the mining cost. Results WildSpan is shown to efficiently find W-patterns containing conserved residues that are far separated in sequences. We conducted experiments with two mining strategies, protein-based and family-based mining, to evaluate the usefulness of W-patterns and performance of WildSpan. The protein-based mining mode

Localized surface disruptions observed by InSAR during strong earthquakes in Java and Hawai'i

Science.gov (United States)

Poland, M.

2010-01-01

Interferometric Synthetic Aperture Radar data spanning strong earthquakes on the islands of Java and Hawai‘i in 2006 reveal patches of subsidence and incoherence indicative of localized ground failure. Interferograms spanning the 26 May 2006 Java earthquake suggest an area of about 7.5 km2 of subsidence (~2 cm) and incoherence south of the city of Yogyakarta that correlates with significant damage to housing, high modeled peak ground accelerations, and poorly consolidated geologic deposits. The subsidence and incoherence is inferred to be a result of intense shaking and/or damage. At least five subsidence patches on the west side of the Island of Hawai‘i, ranging 0.3–2.2 km2 in area and 3–8 cm in magnitude, occurred as a result of a pair of strong earthquakes on 15 October 2006. Although no felt reports or seismic data are available from the areas in Hawai‘i, the Java example suggests that the subsidence patches indicate areas of amplified earthquake shaking. Surprisingly, all subsidence areas in Hawai‘i were limited to recent, and supposedly stable, lava flows and may reflect geological conditions not detectable at the surface. In addition, two ‘a‘ā lava flows in Hawai‘i were partially incoherent in interferograms spanning the earthquakes, indicating surface disruption as a result of the earthquake shaking. Coearthquake incoherence of rubbly deposits, like ‘a‘ā flows, should be explored as a potential indicator of earthquake intensity and past strong seismic activity.

Mapping the developmental constraints on working memory span performance.

Science.gov (United States)

Bayliss, Donna M; Jarrold, Christopher; Baddeley, Alan D; Gunn, Deborah M; Leigh, Eleanor

2005-07-01

This study investigated the constraints underlying developmental improvements in complex working memory span performance among 120 children of between 6 and 10 years of age. Independent measures of processing efficiency, storage capacity, rehearsal speed, and basic speed of processing were assessed to determine their contribution to age-related variance in complex span. Results showed that developmental improvements in complex span were driven by 2 age-related but separable factors: 1 associated with general speed of processing and 1 associated with storage ability. In addition, there was an age-related contribution shared between working memory, processing speed, and storage ability that was important for higher level cognition. These results pose a challenge for models of complex span performance that emphasize the importance of processing speed alone.

Frugivorous bats maintain functional habitat connectivity in agricultural landscapes but rely strongly on natural forest fragments.

Science.gov (United States)

Ripperger, Simon P; Kalko, Elisabeth K V; Rodríguez-Herrera, Bernal; Mayer, Frieder; Tschapka, Marco

2015-01-01

Anthropogenic changes in land use threaten biodiversity and ecosystem functioning by the conversion of natural habitat into agricultural mosaic landscapes, often with drastic consequences for the associated fauna. The first step in the development of efficient conservation plans is to understand movement of animals through complex habitat mosaics. Therefore, we studied ranging behavior and habitat use in Dermanura watsoni (Phyllostomidae), a frugivorous bat species that is a valuable seed disperser in degraded ecosystems. Radio-tracking of sixteen bats showed that the animals strongly rely on natural forest. Day roosts were exclusively located within mature forest fragments. Selection ratios showed that the bats foraged selectively within the available habitat and positively selected natural forest. However, larger daily ranges were associated with higher use of degraded habitats. Home range geometry and composition of focal foraging areas indicated that wider ranging bats performed directional foraging bouts from natural to degraded forest sites traversing the matrix over distances of up to three hundred meters. This behavior demonstrates the potential of frugivorous bats to functionally connect fragmented areas by providing ecosystem services between natural and degraded sites, and highlights the need for conservation of natural habitat patches within agricultural landscapes that meet the roosting requirements of bats.

Frugivorous bats maintain functional habitat connectivity in agricultural landscapes but rely strongly on natural forest fragments.

Directory of Open Access Journals (Sweden)

Simon P Ripperger

Full Text Available Anthropogenic changes in land use threaten biodiversity and ecosystem functioning by the conversion of natural habitat into agricultural mosaic landscapes, often with drastic consequences for the associated fauna. The first step in the development of efficient conservation plans is to understand movement of animals through complex habitat mosaics. Therefore, we studied ranging behavior and habitat use in Dermanura watsoni (Phyllostomidae, a frugivorous bat species that is a valuable seed disperser in degraded ecosystems. Radio-tracking of sixteen bats showed that the animals strongly rely on natural forest. Day roosts were exclusively located within mature forest fragments. Selection ratios showed that the bats foraged selectively within the available habitat and positively selected natural forest. However, larger daily ranges were associated with higher use of degraded habitats. Home range geometry and composition of focal foraging areas indicated that wider ranging bats performed directional foraging bouts from natural to degraded forest sites traversing the matrix over distances of up to three hundred meters. This behavior demonstrates the potential of frugivorous bats to functionally connect fragmented areas by providing ecosystem services between natural and degraded sites, and highlights the need for conservation of natural habitat patches within agricultural landscapes that meet the roosting requirements of bats.

Performance, Career Dynamics, and Span of Control

DEFF Research Database (Denmark)

Smeets, Valerie Anne Rolande; Waldman, Michael; Warzynski, Frederic Michel Patrick

that higher ability managers should supervise more subordinates, or equivalently, have a larger span of control. And although some of this theory’s predictions have been empirically investigated, there has been little systematic investigation of the theory’s predictions concerning span of control....... In this paper we first extend the theoretical literature on the scale-of-operations effect to allow firms’ beliefs concerning a manager’s ability to evolve over the manager’s career, where much of our focus is the determinants of span of control. We then empirically investigate testable predictions from......There is an extensive theoretical literature based on what is called the scale-of-operations effect, i.e., the idea that the return to managerial ability is higher the more resources the manager influences with his or her decisions. This idea leads to various testable predictions including...

How strong and generalisable is the Generation Y effect?

DEFF Research Database (Denmark)

Mueller, Simone; Remaud, Hervé; Chabin, Yann

2011-01-01

Purpose – This study aims to investigate how strongly Generation Y consumers differ in their values, attitudes and wine and alcoholic beverage consumption behaviour from older generations. The comparison spans seven culturally different markets. Design/methodology/approach – Large representative...... alcoholic beverage consumption. A number of noticeable differences appeared between countries: wine involvement and consumption increases with age in traditional European wine markets, while they decrease in North America; environmental concerns and purchase channel usage hardly differ between generations...

Radial Distribution Functions of Strongly Coupled Two-Temperature Plasmas

Science.gov (United States)

Shaffer, Nathaniel R.; Tiwari, Sanat Kumar; Baalrud, Scott D.

2017-10-01

We present tests of three theoretical models for the radial distribution functions (RDFs) in two-temperature strongly coupled plasmas. RDFs are useful in extending plasma thermodynamics and kinetic theory to strong coupling, but they are usually known only for thermal equilibrium or for approximate one-component model plasmas. Accurate two-component modeling is necessary to understand the impact of strong coupling on inter-species transport, e.g., ambipolar diffusion and electron-ion temperature relaxation. We demonstrate that the Seuferling-Vogel-Toeppfer (SVT) extension of the hypernetted chain equations not only gives accurate RDFs (as compared with classical molecular dynamics simulations), but also has a simple connection with the Yukawa OCP model. This connection gives a practical means to recover the structure of the electron background from knowledge of the ion-ion RDF alone. Using the model RDFs in Effective Potential Theory, we report the first predictions of inter-species transport coefficients of strongly coupled plasmas far from equilibrium. This work is supported by NSF Grant No. PHY-1453736, AFSOR Award No. FA9550-16-1-0221, and used XSEDE computational resources.

Dynamics of investor spanning trees around dot-com bubble.

Directory of Open Access Journals (Sweden)

Sindhuja Ranganathan

Full Text Available We identify temporal investor networks for Nokia stock by constructing networks from correlations between investor-specific net-volumes and analyze changes in the networks around dot-com bubble. The analysis is conducted separately for households, financial, and non-financial institutions. Our results indicate that spanning tree measures for households reflected the boom and crisis: the maximum spanning tree measures had a clear upward tendency in the bull markets when the bubble was building up, and, even more importantly, the minimum spanning tree measures pre-reacted the burst of the bubble. At the same time, we find less clear reactions in the minimal and maximal spanning trees of non-financial and financial institutions around the bubble, which suggests that household investors can have a greater herding tendency around bubbles.

Dynamics of investor spanning trees around dot-com bubble.

Science.gov (United States)

Ranganathan, Sindhuja; Kivelä, Mikko; Kanniainen, Juho

2018-01-01

We identify temporal investor networks for Nokia stock by constructing networks from correlations between investor-specific net-volumes and analyze changes in the networks around dot-com bubble. The analysis is conducted separately for households, financial, and non-financial institutions. Our results indicate that spanning tree measures for households reflected the boom and crisis: the maximum spanning tree measures had a clear upward tendency in the bull markets when the bubble was building up, and, even more importantly, the minimum spanning tree measures pre-reacted the burst of the bubble. At the same time, we find less clear reactions in the minimal and maximal spanning trees of non-financial and financial institutions around the bubble, which suggests that household investors can have a greater herding tendency around bubbles.

Detecting Functional Connectivity During Audiovisual Integration with MEG: A Comparison of Connectivity Metrics.

Science.gov (United States)

Ard, Tyler; Carver, Frederick W; Holroyd, Tom; Horwitz, Barry; Coppola, Richard

2015-08-01

In typical magnetoencephalography and/or electroencephalography functional connectivity analysis, researchers select one of several methods that measure a relationship between regions to determine connectivity, such as coherence, power correlations, and others. However, it is largely unknown if some are more suited than others for various types of investigations. In this study, the authors investigate seven connectivity metrics to evaluate which, if any, are sensitive to audiovisual integration by contrasting connectivity when tracking an audiovisual object versus connectivity when tracking a visual object uncorrelated with the auditory stimulus. The authors are able to assess the metrics' performances at detecting audiovisual integration by investigating connectivity between auditory and visual areas. Critically, the authors perform their investigation on a whole-cortex all-to-all mapping, avoiding confounds introduced in seed selection. The authors find that amplitude-based connectivity measures in the beta band detect strong connections between visual and auditory areas during audiovisual integration, specifically between V4/V5 and auditory cortices in the right hemisphere. Conversely, phase-based connectivity measures in the beta band as well as phase and power measures in alpha, gamma, and theta do not show connectivity between audiovisual areas. The authors postulate that while beta power correlations detect audiovisual integration in the current experimental context, it may not always be the best measure to detect connectivity. Instead, it is likely that the brain utilizes a variety of mechanisms in neuronal communication that may produce differential types of temporal relationships.

Developmental Dyslexia: The Visual Attention Span Deficit Hypothesis

Science.gov (United States)

Bosse, Marie-Line; Tainturier, Marie Josephe; Valdois, Sylviane

2007-01-01

The visual attention (VA) span is defined as the amount of distinct visual elements which can be processed in parallel in a multi-element array. Both recent empirical data and theoretical accounts suggest that a VA span deficit might contribute to developmental dyslexia, independently of a phonological disorder. In this study, this hypothesis was…

Noise Reduction with Optimal Variable Span Linear Filters

DEFF Research Database (Denmark)

Jensen, Jesper Rindom; Benesty, Jacob; Christensen, Mads Græsbøll

2016-01-01

In this paper, the problem of noise reduction is addressed as a linear filtering problem in a novel way by using concepts from subspace-based enhancement methods, resulting in variable span linear filters. This is done by forming the filter coefficients as linear combinations of a number...... included in forming the filter. Using these concepts, a number of different filter designs are considered, like minimum distortion, Wiener, maximum SNR, and tradeoff filters. Interestingly, all these can be expressed as special cases of variable span filters. We also derive expressions for the speech...... demonstrate the advantages and properties of the variable span filter designs, and their potential performance gain compared to widely used speech enhancement methods....

GEMINI/GMOS SPECTROSCOPY OF 26 STRONG-LENSING-SELECTED GALAXY CLUSTER CORES

International Nuclear Information System (INIS)

Bayliss, Matthew B.; Gladders, Michael D.; Koester, Benjamin P.; Hennawi, Joseph F.; Sharon, Keren; Dahle, Haakon; Oguri, Masamune

2011-01-01

We present results from a spectroscopic program targeting 26 strong-lensing cluster cores that were visually identified in the Sloan Digital Sky Survey (SDSS) and the Second Red-Sequence Cluster Survey (RCS-2). The 26 galaxy cluster lenses span a redshift range of 0.2 Vir = 7.84 x 10 14 M sun h -1 0.7 , which is somewhat higher than predictions for strong-lensing-selected clusters in simulations. The disagreement is not significant considering the large uncertainty in our dynamical data, systematic uncertainties in the velocity dispersion calibration, and limitations of the theoretical modeling. Nevertheless our study represents an important first step toward characterizing large samples of clusters that are identified in a systematic way as systems exhibiting dramatic strong-lensing features.

Positive semidefinite matrix completion, universal rigidity and the Strong Arnold Property

NARCIS (Netherlands)

M. Laurent (Monique); A. Varvitsiotis (Antonios)

2014-01-01

htmlabstractThis paper addresses the following three topics: positive semidefinite (psd) matrix completions, universal rigidity of frameworks, and the Strong Arnold Property (SAP). We show some strong connections among these topics, using semidefinite programming as unifying theme. Our main

Positive semidefinite matrix completion, universal rigidity and the Strong Arnold Property

NARCIS (Netherlands)

Laurent, Monique; Varvitsiotis, A.

This paper addresses the following three topics: positive semidefinite (psd) matrix completions, universal rigidity of frameworks, and the Strong Arnold Property (SAP). We show some strong connections among these topics, using semidefinite programming as unifying theme. Our main contribution is a

Dual boundary spanning

DEFF Research Database (Denmark)

Li-Ying, Jason

2016-01-01

The extant literature runs short in understanding openness of innovation regarding and the different pathways along which internal and external knowledge resources can be combined. This study proposes a unique typology for outside-in innovations based on two distinct ways of boundary spanning......: whether an innovation idea is created internally or externally and whether an innovation process relies on external knowledge resources. This yields four possible types of innovation, which represent the nuanced variation of outside-in innovations. Using historical data from Canada for 1945...

Exploring boundary-spanning practices among creativity managers

DEFF Research Database (Denmark)

Andersen, Poul Houman; Kragh, Hanne

2015-01-01

Purpose – External inputs are critical for organisational creativity. In order to bridge different thought worlds and cross-organisational barriers, managers must initiate and motivate boundary spanning processes. The purpose of this paper is to explore how boundary spanners manage creativity...... and observation. Findings – Three meta-practices used by managers to manage boundary-spanning creative projects are presented: defining the creative space, making space for creativity and acting in the creative space. These practices are detailed in seven case studies of creative projects. Research limitations...

Hematopoietic stem cell origin of connective tissues.

Science.gov (United States)

Ogawa, Makio; Larue, Amanda C; Watson, Patricia M; Watson, Dennis K

2010-07-01

Connective tissue consists of "connective tissue proper," which is further divided into loose and dense (fibrous) connective tissues and "specialized connective tissues." Specialized connective tissues consist of blood, adipose tissue, cartilage, and bone. In both loose and dense connective tissues, the principal cellular element is fibroblasts. It has been generally believed that all cellular elements of connective tissue, including fibroblasts, adipocytes, chondrocytes, and bone cells, are generated solely by mesenchymal stem cells. Recently, a number of studies, including those from our laboratory based on transplantation of single hematopoietic stem cells, strongly suggested a hematopoietic stem cell origin of these adult mesenchymal tissues. This review summarizes the experimental evidence for this new paradigm and discusses its translational implications. Copyright 2010 ISEH - Society for Hematology and Stem Cells. All rights reserved.

Connectivity-based parcellation of the human orbitofrontal cortex.

Science.gov (United States)

Kahnt, Thorsten; Chang, Luke J; Park, Soyoung Q; Heinzle, Jakob; Haynes, John-Dylan

2012-05-02

The primate orbitofrontal cortex (OFC) is involved in reward processing, learning, and decision making. Research in monkeys has shown that this region is densely connected with higher sensory, limbic, and subcortical regions. Moreover, a parcellation of the monkey OFC into two subdivisions has been suggested based on its intrinsic anatomical connections. However, in humans, little is known about any functional subdivisions of the OFC except for a rather coarse medial/lateral distinction. Here, we used resting-state fMRI in combination with unsupervised clustering techniques to investigate whether OFC subdivisions can be revealed based on their functional connectivity profiles with other brain regions. Examination of different cluster solutions provided support for a parcellation into two parts as observed in monkeys, but it also highlighted a much finer hierarchical clustering of the orbital surface. Specifically, we identified (1) a medial, (2) a posterior-central, (3) a central, and (4-6) three lateral clusters spanning the anterior-posterior gradient. Consistent with animal tracing studies, these OFC clusters were connected to other cortical regions such as prefrontal, temporal, and parietal cortices but also subcortical areas in the striatum and the midbrain. These connectivity patterns provide important implications for identifying specific functional roles of OFC subdivisions for reward processing, learning, and decision making. Moreover, this parcellation schema can provide guidance to report results in future studies.

Controlling the spotlight of attention: visual span size and flexibility in schizophrenia.

Science.gov (United States)

Elahipanah, Ava; Christensen, Bruce K; Reingold, Eyal M

2011-10-01

The current study investigated the size and flexible control of visual span among patients with schizophrenia during visual search performance. Visual span is the region of the visual field from which one extracts information during a single eye fixation, and a larger visual span size is linked to more efficient search performance. Therefore, a reduced visual span may explain patients' impaired performance on search tasks. The gaze-contingent moving window paradigm was used to estimate the visual span size of patients and healthy participants while they performed two different search tasks. In addition, changes in visual span size were measured as a function of two manipulations of task difficulty: target-distractor similarity and stimulus familiarity. Patients with schizophrenia searched more slowly across both tasks and conditions. Patients also demonstrated smaller visual span sizes on the easier search condition in each task. Moreover, healthy controls' visual span size increased as target discriminability or distractor familiarity increased. This modulation of visual span size, however, was reduced or not observed among patients. The implications of the present findings, with regard to previously reported visual search deficits, and other functional and structural abnormalities associated with schizophrenia, are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Life Span Exercise Among Elite Intercollegiate Student Athletes

OpenAIRE

Sorenson, Shawn C.; Romano, Russell; Azen, Stanley P.; Schroeder, E. Todd; Salem, George J.

2015-01-01

Background: Despite prominent public attention, data on life span health and exercise outcomes among elite, competitive athletes are sparse and do not reflect the diversity of modern athletes. Hypothesis: Life span exercise behavior differs between National Collegiate Athletic Association (NCAA) student athletes and a nonathlete control group. Sustained exercise is associated with improved cardiopulmonary health outcomes. Study Design: Cross-sectional, descriptive epidemiology study. Level of...

Quasi-particles and effective mean field in strongly interacting matter

International Nuclear Information System (INIS)

Levai, P.; Ko, C.M.

2010-01-01

We introduce a quasi-particle model of strongly interacting quark-gluon matter and explore the possible connection to an effective field theoretical description consisting of a scalar σ field by introducing a dynamically generated mass, M(σ), and a self-consistently determined interaction term, B(σ). We display a possible connection between the two types of effective description, using the Friedberg-Lee model.

Random Interchange of Magnetic Connectivity

Science.gov (United States)

Matthaeus, W. H.; Ruffolo, D. J.; Servidio, S.; Wan, M.; Rappazzo, A. F.

2015-12-01

Magnetic connectivity, the connection between two points along a magnetic field line, has a stochastic character associated with field lines random walking in space due to magnetic fluctuations, but connectivity can also change in time due to dynamical activity [1]. For fluctuations transverse to a strong mean field, this connectivity change be caused by stochastic interchange due to component reconnection. The process may be understood approximately by formulating a diffusion-like Fokker-Planck coefficient [2] that is asymptotically related to standard field line random walk. Quantitative estimates are provided, for transverse magnetic field models and anisotropic models such as reduced magnetohydrodynamics. In heliospheric applications, these estimates may be useful for understanding mixing between open and close field line regions near coronal hole boundaries, and large latitude excursions of connectivity associated with turbulence. [1] A. F. Rappazzo, W. H. Matthaeus, D. Ruffolo, S. Servidio & M. Velli, ApJL, 758, L14 (2012) [2] D. Ruffolo & W. Matthaeus, ApJ, 806, 233 (2015)

Synchronization from Second Order Network Connectivity Statistics

Science.gov (United States)

Zhao, Liqiong; Beverlin, Bryce; Netoff, Theoden; Nykamp, Duane Q.

2011-01-01

We investigate how network structure can influence the tendency for a neuronal network to synchronize, or its synchronizability, independent of the dynamical model for each neuron. The synchrony analysis takes advantage of the framework of second order networks, which defines four second order connectivity statistics based on the relative frequency of two-connection network motifs. The analysis identifies two of these statistics, convergent connections, and chain connections, as highly influencing the synchrony. Simulations verify that synchrony decreases with the frequency of convergent connections and increases with the frequency of chain connections. These trends persist with simulations of multiple models for the neuron dynamics and for different types of networks. Surprisingly, divergent connections, which determine the fraction of shared inputs, do not strongly influence the synchrony. The critical role of chains, rather than divergent connections, in influencing synchrony can be explained by their increasing the effective coupling strength. The decrease of synchrony with convergent connections is primarily due to the resulting heterogeneity in firing rates. PMID:21779239

Mercury bioaccumulation in bats reflects dietary connectivity to aquatic food webs.

Science.gov (United States)

Becker, Daniel J; Chumchal, Matthew M; Broders, Hugh G; Korstian, Jennifer M; Clare, Elizabeth L; Rainwater, Thomas R; Platt, Steven G; Simmons, Nancy B; Fenton, M Brock

2018-02-01

Mercury (Hg) is a persistent and widespread heavy metal with neurotoxic effects in wildlife. While bioaccumulation of Hg has historically been studied in aquatic food webs, terrestrial consumers can become contaminated with Hg when they feed on aquatic organisms (e.g., emergent aquatic insects, fish, and amphibians). However, the extent to which dietary connectivity to aquatic ecosystems can explain patterns of Hg bioaccumulation in terrestrial consumers has not been well studied. Bats (Order: Chiroptera) can serve as a model system for illuminating the trophic transfer of Hg given their high dietary diversity and foraging links to both aquatic and terrestrial food webs. Here we quantitatively characterize the dietary correlates of long-term exposure to Hg across a diverse local assemblage of bats in Belize and more globally across bat species from around the world with a comparative analysis of hair samples. Our data demonstrate considerable interspecific variation in hair total Hg concentrations in bats that span three orders of magnitude across species, ranging from 0.04 mg/kg in frugivorous bats (Artibeus spp.) to 145.27 mg/kg in the piscivorous Noctilio leporinus. Hg concentrations showed strong phylogenetic signal and were best explained by dietary connectivity of bat species to aquatic food webs. Our results highlight that phylogeny can be predictive of Hg concentrations through similarity in diet and how interspecific variation in feeding strategies influences chronic exposure to Hg and enables movement of contaminants from aquatic to terrestrial ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Vision in Flies: Measuring the Attention Span.

Directory of Open Access Journals (Sweden)

Sebastian Koenig

Full Text Available A visual stimulus at a particular location of the visual field may elicit a behavior while at the same time equally salient stimuli in other parts do not. This property of visual systems is known as selective visual attention (SVA. The animal is said to have a focus of attention (FoA which it has shifted to a particular location. Visual attention normally involves an attention span at the location to which the FoA has been shifted. Here the attention span is measured in Drosophila. The fly is tethered and hence has its eyes fixed in space. It can shift its FoA internally. This shift is revealed using two simultaneous test stimuli with characteristic responses at their particular locations. In tethered flight a wild type fly keeps its FoA at a certain location for up to 4s. Flies with a mutation in the radish gene, that has been suggested to be involved in attention-like mechanisms, display a reduced attention span of only 1s.

Vision in Flies: Measuring the Attention Span.

Science.gov (United States)

Koenig, Sebastian; Wolf, Reinhard; Heisenberg, Martin

2016-01-01

A visual stimulus at a particular location of the visual field may elicit a behavior while at the same time equally salient stimuli in other parts do not. This property of visual systems is known as selective visual attention (SVA). The animal is said to have a focus of attention (FoA) which it has shifted to a particular location. Visual attention normally involves an attention span at the location to which the FoA has been shifted. Here the attention span is measured in Drosophila. The fly is tethered and hence has its eyes fixed in space. It can shift its FoA internally. This shift is revealed using two simultaneous test stimuli with characteristic responses at their particular locations. In tethered flight a wild type fly keeps its FoA at a certain location for up to 4s. Flies with a mutation in the radish gene, that has been suggested to be involved in attention-like mechanisms, display a reduced attention span of only 1s.

Increasing Endurance by Building Fluency: Precision Teaching Attention Span.

Science.gov (United States)

Binder, Carl; And Others

1990-01-01

Precision teaching techniques can be used to chart students' attention span or endurance. Individual differences in attention span can then be better understood and dealt with effectively. The effects of performance duration on performance level, on error rates, and on learning rates are discussed. Implications for classroom practice are noted.…

Life span extension and neuronal cell protection by Drosophila nicotinamidase.

Science.gov (United States)

Balan, Vitaly; Miller, Gregory S; Kaplun, Ludmila; Balan, Karina; Chong, Zhao-Zhong; Li, Faqi; Kaplun, Alexander; VanBerkum, Mark F A; Arking, Robert; Freeman, D Carl; Maiese, Kenneth; Tzivion, Guri

2008-10-10

The life span of model organisms can be modulated by environmental conditions that influence cellular metabolism, oxidation, or DNA integrity. The yeast nicotinamidase gene pnc1 was identified as a key transcriptional target and mediator of calorie restriction and stress-induced life span extension. PNC1 is thought to exert its effect on yeast life span by modulating cellular nicotinamide and NAD levels, resulting in increased activity of Sir2 family class III histone deacetylases. In Caenorhabditis elegans, knockdown of a pnc1 homolog was shown recently to shorten the worm life span, whereas its overexpression increased survival under conditions of oxidative stress. The function and regulation of nicotinamidases in higher organisms has not been determined. Here, we report the identification and biochemical characterization of the Drosophila nicotinamidase, D-NAAM, and demonstrate that its overexpression significantly increases median and maximal fly life span. The life span extension was reversed in Sir2 mutant flies, suggesting Sir2 dependence. Testing for physiological effectors of D-NAAM in Drosophila S2 cells, we identified oxidative stress as a primary regulator, both at the transcription level and protein activity. In contrast to the yeast model, stress factors such as high osmolarity and heat shock, calorie restriction, or inhibitors of TOR and phosphatidylinositol 3-kinase pathways do not appear to regulate D-NAAM in S2 cells. Interestingly, the expression of D-NAAM in human neuronal cells conferred protection from oxidative stress-induced cell death in a sirtuin-dependent manner. Together, our findings establish a life span extending the ability of nicotinamidase in flies and offer a role for nicotinamide-modulating genes in oxidative stress regulated pathways influencing longevity and neuronal cell survival.

A Minimum Spanning Tree Representation of Anime Similarities

OpenAIRE

Wibowo, Canggih Puspo

2016-01-01

In this work, a new way to represent Japanese animation (anime) is presented. We applied a minimum spanning tree to show the relation between anime. The distance between anime is calculated through three similarity measurements, namely crew, score histogram, and topic similarities. Finally, the centralities are also computed to reveal the most significance anime. The result shows that the minimum spanning tree can be used to determine the similarity anime. Furthermore, by using centralities c...

Self-esteem development across the life span: a longitudinal study with a large sample from Germany.

Science.gov (United States)

Orth, Ulrich; Maes, Jürgen; Schmitt, Manfred

2015-02-01

The authors examined the development of self-esteem across the life span. Data came from a German longitudinal study with 3 assessments across 4 years of a sample of 2,509 individuals ages 14 to 89 years. The self-esteem measure used showed strong measurement invariance across assessments and birth cohorts. Latent growth curve analyses indicated that self-esteem follows a quadratic trajectory across the life span, increasing during adolescence, young adulthood, and middle adulthood, reaching a peak at age 60 years, and then declining in old age. No cohort effects on average levels of self-esteem or on the shape of the trajectory were found. Moreover, the trajectory did not differ across gender, level of education, or for individuals who had lived continuously in West versus East Germany (i.e., the 2 parts of Germany that had been separate states from 1949 to 1990). However, the results suggested that employment status, household income, and satisfaction in the domains of work, relationships, and health contribute to a more positive life span trajectory of self-esteem. The findings have significant implications, because they call attention to developmental stages in which individuals may be vulnerable because of low self-esteem (such as adolescence and old age) and to factors that predict successful versus problematic developmental trajectories. PsycINFO Database Record (c) 2015 APA, all rights reserved.

Two-carbon metabolites, polyphenols and vitamins influence yeast chronological life span in winemaking conditions

Directory of Open Access Journals (Sweden)

Orozco Helena

2012-08-01

Full Text Available Abstract Background Viability in a non dividing state is referred to as chronological life span (CLS. Most grape juice fermentation happens when Saccharomyces cerevisiae yeast cells have stopped dividing; therefore, CLS is an important factor toward winemaking success. Results We have studied both the physical and chemical determinants influencing yeast CLS. Low pH and heat shorten the maximum wine yeast life span, while hyperosmotic shock extends it. Ethanol plays an important negative role in aging under winemaking conditions, but additional metabolites produced by fermentative metabolism, such as acetaldehyde and acetate, have also a strong impact on longevity. Grape polyphenols quercetin and resveratrol have negative impacts on CLS under winemaking conditions, an unexpected behavior for these potential anti-oxidants. We observed that quercetin inhibits alcohol and aldehyde dehydrogenase activities, and that resveratrol performs a pro-oxidant role during grape juice fermentation. Vitamins nicotinic acid and nicotinamide are precursors of NAD+, and their addition reduces mean longevity during fermentation, suggesting a metabolic unbalance negative for CLS. Moreover, vitamin mix supplementation at the end of fermentation shortens CLS and enhances cell lysis, while amino acids increase life span. Conclusions Wine S. cerevisiae strains are able to sense changes in the environmental conditions and adapt their longevity to them. Yeast death is influenced by the conditions present at the end of wine fermentation, particularly by the concentration of two-carbon metabolites produced by the fermentative metabolism, such as ethanol, acetic acid and acetaldehyde, and also by the grape juice composition, particularly its vitamin content.

Power, Governance and Boundary Spanning Leadership in Public Sector Organisations

DEFF Research Database (Denmark)

Elmholdt, Claus Westergård; Fogsgaard, Morten

2015-01-01

the fact that analysis of boundary spanning leadership and power relations is an essential, significant, and critical tool in questioning different forms of management in public sector organizations. The aim of the workshop is to investigate, elucidate and discuss management across organizational units...... on the practice that evolves on the boundaries that span occupational groups, departments and organizations. The workshop takes it’s starting point in an interdisciplinary Scandinavian research project which deals with the question of how power processes can promote, or hinder, boundary spanning leadership...

The UCLA Multimodal Connectivity Database: A web-based platform for brain connectivity matrix sharing and analysis

Directory of Open Access Journals (Sweden)

Jesse A. Brown

2012-11-01

Full Text Available Brain connectomics research has rapidly expanded using functional MRI (fMRI and diffusion-weighted MRI (dwMRI. A common product of these varied analyses is a connectivity matrix (CM. A CM stores the connection strength between any two regions (nodes in a brain network. This format is useful for several reasons: 1 it is highly distilled, with minimal data size and complexity, 2 graph theory can be applied to characterize the network’s topology, and 3 it retains sufficient information to capture individual differences such as age, gender, intelligence quotient, or disease state. Here we introduce the UCLA Multimodal Connectivity Database (http://umcd.humanconnectomeproject.org, an openly available website for brain network analysis and data sharing. The site is a repository for researchers to publicly share CMs derived from their data. The site also allows users to select any CM shared by another user, compute graph theoretical metrics on the site, visualize a report of results, or download the raw CM. To date, users have contributed over 2000 individual CMs, spanning different imaging modalities (fMRI, dwMRI and disorders (Alzheimer’s, autism, Attention Deficit Hyperactive Disorder. To demonstrate the site’s functionality, whole brain functional and structural connectivity matrices are derived from 60 subjects’ (ages 26-45 resting state fMRI (rs-fMRI and dwMRI data and uploaded to the site. The site is utilized to derive graph theory global and regional measures for the rs-fMRI and dwMRI networks. Global and nodal graph theoretical measures between functional and structural networks exhibit low correspondence. This example demonstrates how this tool can enhance the comparability of brain networks from different imaging modalities and studies. The existence of this connectivity-based repository should foster broader data sharing and enable larger-scale meta analyses comparing networks across imaging modality, age group, and disease state.

Decision-making heuristics and biases across the life span

Science.gov (United States)

Strough, JoNell; Karns, Tara E.; Schlosnagle, Leo

2013-01-01

We outline a contextual and motivational model of judgment and decision-making (JDM) biases across the life span. Our model focuses on abilities and skills that correspond to deliberative, experiential, and affective decision-making processes. We review research that addresses links between JDM biases and these processes as represented by individual differences in specific abilities and skills (e.g., fluid and crystallized intelligence, executive functioning, emotion regulation, personality traits). We focus on two JDM biases—the sunk-cost fallacy (SCF) and the framing effect. We trace the developmental trajectory of each bias from preschool through middle childhood, adolescence, early adulthood, and later adulthood. We conclude that life-span developmental trajectories differ depending on the bias investigated. Existing research suggests relative stability in the framing effect across the life span and decreases in the SCF with age, including in later life. We highlight directions for future research on JDM biases across the life span, emphasizing the need for process-oriented research and research that increases our understanding of JDM biases in people’s everyday lives. PMID:22023568

Decision-making heuristics and biases across the life span.

Science.gov (United States)

Strough, Jonell; Karns, Tara E; Schlosnagle, Leo

2011-10-01

We outline a contextual and motivational model of judgment and decision-making (JDM) biases across the life span. Our model focuses on abilities and skills that correspond to deliberative, experiential, and affective decision-making processes. We review research that addresses links between JDM biases and these processes as represented by individual differences in specific abilities and skills (e.g., fluid and crystallized intelligence, executive functioning, emotion regulation, personality traits). We focus on two JDM biases-the sunk-cost fallacy (SCF) and the framing effect. We trace the developmental trajectory of each bias from preschool through middle childhood, adolescence, early adulthood, and later adulthood. We conclude that life-span developmental trajectories differ depending on the bias investigated. Existing research suggests relative stability in the framing effect across the life span and decreases in the SCF with age, including in later life. We highlight directions for future research on JDM biases across the life span, emphasizing the need for process-oriented research and research that increases our understanding of JDM biases in people's everyday lives. © 2011 New York Academy of Sciences.

Functional connectivity changes detected with magnetoencephalography after mild traumatic brain injury

Directory of Open Access Journals (Sweden)

Stavros I. Dimitriadis

2015-01-01

Full Text Available Mild traumatic brain injury (mTBI may affect normal cognition and behavior by disrupting the functional connectivity networks that mediate efficient communication among brain regions. In this study, we analyzed brain connectivity profiles from resting state Magnetoencephalographic (MEG recordings obtained from 31 mTBI patients and 55 normal controls. We used phase-locking value estimates to compute functional connectivity graphs to quantify frequency-specific couplings between sensors at various frequency bands. Overall, normal controls showed a dense network of strong local connections and a limited number of long-range connections that accounted for approximately 20% of all connections, whereas mTBI patients showed networks characterized by weak local connections and strong long-range connections that accounted for more than 60% of all connections. Comparison of the two distinct general patterns at different frequencies using a tensor representation for the connectivity graphs and tensor subspace analysis for optimal feature extraction showed that mTBI patients could be separated from normal controls with 100% classification accuracy in the alpha band. These encouraging findings support the hypothesis that MEG-based functional connectivity patterns may be used as biomarkers that can provide more accurate diagnoses, help guide treatment, and monitor effectiveness of intervention in mTBI.

The Life Span Dwelling

OpenAIRE

Hans-Peter Hebensperger-Hüther; Gabriele Franger-Huhle

2014-01-01

The paper presents the findings from a survey of 10 different experimental housing projects in Bavaria. In 2005 students of architecture and students of social work at the University of Applied Science in Coburg approached the topic of “Life Span Dwelling” using interdisciplinary research methods. The scope of the research ranges from urban planning concepts to common spaces in the different neighborhoods, documenting user satisfaction with the individual unit and feasibility of rooms offered...

Thermal Stimulation Alters Cervical Spinal Cord Functional Connectivity in Humans.

Science.gov (United States)

Weber, Kenneth A; Sentis, Amy I; Bernadel-Huey, Olivia N; Chen, Yufen; Wang, Xue; Parrish, Todd B; Mackey, Sean

2018-01-15

The spinal cord has an active role in the modulation and transmission of the neural signals traveling between the body and the brain. Recent advancements in functional magnetic resonance imaging (fMRI) have made the in vivo examination of spinal cord function in humans now possible. This technology has been recently extended to the investigation of resting state functional networks in the spinal cord, leading to the identification of distinct patterns of spinal cord functional connectivity. In this study, we expand on the previous work and further investigate resting state cervical spinal cord functional connectivity in healthy participants (n = 15) using high resolution imaging coupled with both seed-based functional connectivity analyses and graph theory-based metrics. Within spinal cord segment functional connectivity was present between the left and right ventral horns (bilateral motor network), left and right dorsal horns (bilateral sensory network), and the ipsilateral ventral and dorsal horns (unilateral sensory-motor network). Functional connectivity between the spinal cord segments was less apparent with the connectivity centered at the region of interest and spanning spinal cord functional network was demonstrated to be state-dependent as thermal stimulation of the right ventrolateral forearm resulted in significant disruption of the bilateral sensory network, increased network global efficiency, and decreased network modularity. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Life span of animals under acute and chronic irradiation

International Nuclear Information System (INIS)

Zapol'skaya, N.A.; Fedorova, A.V.; Borisova, V.V.

1978-01-01

The study has been designed to see to what extent a single and long-term external and internal irradiations shorten the life span of animals. LDsub(50/30) for certain radionuclides whose absorbed doses show different spatiotemporal distributions are considered. It has been found that as far as the average life span is concerned, 137 Cs and 90 Sr have approximately the same effect whether they enter the body on a single occasion or repeatedly. With chronic total-body external gamma-irradiation, the decrease in life span is 5 times smaller than than with single-occasion irradiation. The main reason for the observed differences are found to be differences in the rates with which the absorbed doses are formed

From elongated spanning trees to vicious random walks

OpenAIRE

Gorsky, A.; Nechaev, S.; Poghosyan, V. S.; Priezzhev, V. B.

2012-01-01

Given a spanning forest on a large square lattice, we consider by combinatorial methods a correlation function of $k$ paths ($k$ is odd) along branches of trees or, equivalently, $k$ loop--erased random walks. Starting and ending points of the paths are grouped in a fashion a $k$--leg watermelon. For large distance $r$ between groups of starting and ending points, the ratio of the number of watermelon configurations to the total number of spanning trees behaves as $r^{-\

Asthma Research: The NIH–NJRC Connection

Science.gov (United States)

... Bar Home Current Issue Past Issues Special Section Asthma Research: The NIH–NJRC Connection Past Issues / Fall ... the many ways that NIH supports and promotes asthma research is through its strong relationship with National ...

Strong Coupling Holography

CERN Document Server

Dvali, Gia

2009-01-01

We show that whenever a 4-dimensional theory with N particle species emerges as a consistent low energy description of a 3-brane embedded in an asymptotically-flat (4+d)-dimensional space, the holographic scale of high-dimensional gravity sets the strong coupling scale of the 4D theory. This connection persists in the limit in which gravity can be consistently decoupled. We demonstrate this effect for orbifold planes, as well as for the solitonic branes and string theoretic D-branes. In all cases the emergence of a 4D strong coupling scale from bulk holography is a persistent phenomenon. The effect turns out to be insensitive even to such extreme deformations of the brane action that seemingly shield 4D theory from the bulk gravity effects. A well understood example of such deformation is given by large 4D Einstein term in the 3-brane action, which is known to suppress the strength of 5D gravity at short distances and change the 5D Newton's law into the four-dimensional one. Nevertheless, we observe that the ...

Life Span and Resiliency Theory: A Critical Review

Directory of Open Access Journals (Sweden)

Alexa Smith-Osborne

2007-05-01

Full Text Available Theories of life span development describe human growth and change over the life cycle (Robbins, Chatterjee, & Canda, 2006. Major types of developmental theories include biological, psychodynamic, behavioral, and social learning, cognitive, moral, and spiritual, and those influenced by systems, empowerment, and conflict theory. Life span development theories commonly focus on ontogenesis and sequential mastery of skills, tasks, and abilities. Social work scholars have pointed out that a limitation of life span and other developmental theory is lack of attention to resilience (Greene, 2007; Robbins et al., 1998. The concept of resilience was developed to “describe relative resistance to psychosocial risk experiences” (Rutter, 1999b, p. 119. Longitudinal studies focused on typical and atypical child development informed theory formulation in developmental psychopathology (Garmezy & Rutter, 1983; Luthar, Cichetti,& Becker, 2000 and in an evolving resilience model (Richardson, 2002; Werner & Smith, 1992. Research on resilience has found a positive relationship between a number of individual traits and contextual variables and resistance to a variety of risk factors among children and adolescents. More recently, resilience research has examined the operation of these same factors in the young adult, middle-age, and elder life stages. This article examines the historical and conceptual progression of the two developmental theories—life span and resiliency—and discusses their application to social work practice and education in human behavior in the social environment.

The optimum spanning catenary cable

Science.gov (United States)

Wang, C. Y.

2015-03-01

A heavy cable spans two points in space. There exists an optimum cable length such that the maximum tension is minimized. If the two end points are at the same level, the optimum length is 1.258 times the distance between the ends. The optimum lengths for end points of different heights are also found.

Van Kampen Colimits as Bicolimits in Span

Science.gov (United States)

Heindel, Tobias; Sobociński, Paweł

The exactness properties of coproducts in extensive categories and pushouts along monos in adhesive categories have found various applications in theoretical computer science, e.g. in program semantics, data type theory and rewriting. We show that these properties can be understood as a single universal property in the associated bicategory of spans. To this end, we first provide a general notion of Van Kampen cocone that specialises to the above colimits. The main result states that Van Kampen cocones can be characterised as exactly those diagrams in ℂ that induce bicolimit diagrams in the bicategory of spans mathcal{S}pan_{mathbb{C}}, provided that ℂ has pullbacks and enough colimits.

Spanning organizational boundaries to manage creative processes:

DEFF Research Database (Denmark)

Andersen, Poul Houman; Kragh, Hanne; Lettl, Christopher

2013-01-01

In order to continue to be innovative in the current fast-paced and competitive environment, organizations are increasingly dependent on creative inputs developed outside their boundaries. The paper addresses the boundary spanning activities that managers undertake to a) select and mobilize...... creative talent, b) create shared identity, and c) combine and integrate knowledge in innovation projects involving external actors. We study boundary spanning activities in two creative projects in the LEGO group. One involves identifying and integrating deep, specialized knowledge, the other focuses...... actors, and how knowledge is integrated across organizational boundaries. We discuss implications of our findings for managers and researchers in a business-to-business context...

Field vibration test of a long-span cable-stayed bridge by large exciters. Daishinpuku kashin ni yoru chodai shachokyo no jikkyo shindo jikken

Energy Technology Data Exchange (ETDEWEB)

Okauchi, I. (Chuo University, Tokyo (Japan). Faculty of Science and Engineering); Miyata, T. (Yokohama National University, Yokohama (Japan). Faculty of Engineering); Sasaki, N. (Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)); Tatsumi, M.

1992-10-15

Long-span cable-stayed bridge requires indispensably discussions on safety against gale and earthquake, and correct assessment on its inherent vibration characteristics at the design stage is critical. However, theoretical assessment on structural decay is difficult, hence it is desirable to make measurement and verification upon its completion. This paper reports the result of measurements and considerations on a three-span continuous steel cable-stayed bridge with a length of 790 m (185 m + 420 m + 185 m) spanning between Hitsuishi Island and Iwakuro Island in the Kojima-Sakaide route of the Honshu-Shikoku connecting bridge. Large shaking machines were used to give girders vibrations with large amplitudes (10 cm at maximum), and high-accuracy measurements were made. The measurements verified the reasonability of the dynamic design for the bridge. The measured value of the logarithmic decay rate [delta] as the major experimental data presented that bending vibration is large as a whole, with torsional vibration somewhat smaller, and all the design values were on safety side. Confirmation was made on amplitude dependence of the decay rate, the inherent modes of low-order vibrations, and coupled behaviors among the girders, cables, and towers. 16 refs., 13 figs., 3 tabs.

Line-of-sight effects in strong lensing: putting theory into practice

Energy Technology Data Exchange (ETDEWEB)

Birrer, Simon; Welschen, Cyril; Amara, Adam; Refregier, Alexandre, E-mail: simon.birrer@phys.ethz.ch, E-mail: cyril.welschen@student.ethz.ch, E-mail: adam.amara@phys.ethz.ch, E-mail: alexandre.refregier@phys.ethz.ch [Institute for Astronomy, Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093, Zurich (Switzerland)

2017-04-01

We present a simple method to accurately infer line of sight (LOS) integrated lensing effects for galaxy scale strong lens systems through image reconstruction. Our approach enables us to separate weak lensing LOS effects from the main strong lens deflector. We test our method using mock data and show that strong lens systems can be accurate probes of cosmic shear with a precision on the shear terms of ± 0.003 (statistical error) for an HST-like dataset. We apply our formalism to reconstruct the lens COSMOS 0038+4133 and its LOS. In addition, we estimate the LOS properties with a halo-rendering estimate based on the COSMOS field galaxies and a galaxy-halo connection. The two approaches are independent and complementary in their information content. We find that when estimating the convergence at the strong lens system, performing a joint analysis improves the measure by a factor of two compared to a halo model only analysis. Furthermore the constraints of the strong lens reconstruction lead to tighter constraints on the halo masses of the LOS galaxies. Joint constraints of multiple strong lens systems may add valuable information to the galaxy-halo connection and may allow independent weak lensing shear measurement calibrations.

From elongated spanning trees to vicious random walks

Science.gov (United States)

Gorsky, A.; Nechaev, S.; Poghosyan, V. S.; Priezzhev, V. B.

2013-05-01

Given a spanning forest on a large square lattice, we consider by combinatorial methods a correlation function of k paths (k is odd) along branches of trees or, equivalently, k loop-erased random walks. Starting and ending points of the paths are grouped such that they form a k-leg watermelon. For large distance r between groups of starting and ending points, the ratio of the number of watermelon configurations to the total number of spanning trees behaves as r-ν log r with ν = (k2 - 1) / 2. Considering the spanning forest stretched along the meridian of this watermelon, we show that the two-dimensional k-leg loop-erased watermelon exponent ν is converting into the scaling exponent for the reunion probability (at a given point) of k (1 + 1)-dimensional vicious walkers, ν˜ =k2 / 2. At the end, we express the conjectures about the possible relation to integrable systems.

From elongated spanning trees to vicious random walks

Energy Technology Data Exchange (ETDEWEB)

Gorsky, A. [ITEP, B. Cheryomushkinskaya 25, 117218 Moscow (Russian Federation); Nechaev, S., E-mail: nechaev@lptms.u-psud.fr [LPTMS, Université Paris Sud, 91405 Orsay Cedex (France); P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 119991 Moscow (Russian Federation); Poghosyan, V.S. [Institute for Informatics and Automation Problems NAS of Armenia, 375044 Yerevan (Armenia); Priezzhev, V.B. [Bogolubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation)

2013-05-01

Given a spanning forest on a large square lattice, we consider by combinatorial methods a correlation function of k paths (k is odd) along branches of trees or, equivalently, k loop-erased random walks. Starting and ending points of the paths are grouped such that they form a k-leg watermelon. For large distance r between groups of starting and ending points, the ratio of the number of watermelon configurations to the total number of spanning trees behaves as r{sup −ν}logr with ν=(k{sup 2}−1)/2. Considering the spanning forest stretched along the meridian of this watermelon, we show that the two-dimensional k-leg loop-erased watermelon exponent ν is converting into the scaling exponent for the reunion probability (at a given point) of k(1+1)-dimensional vicious walkers, ν{sup -tilde=}k{sup 2}/2. At the end, we express the conjectures about the possible relation to integrable systems.

From elongated spanning trees to vicious random walks

International Nuclear Information System (INIS)

Gorsky, A.; Nechaev, S.; Poghosyan, V.S.; Priezzhev, V.B.

2013-01-01

Given a spanning forest on a large square lattice, we consider by combinatorial methods a correlation function of k paths (k is odd) along branches of trees or, equivalently, k loop-erased random walks. Starting and ending points of the paths are grouped such that they form a k-leg watermelon. For large distance r between groups of starting and ending points, the ratio of the number of watermelon configurations to the total number of spanning trees behaves as r −ν logr with ν=(k 2 −1)/2. Considering the spanning forest stretched along the meridian of this watermelon, we show that the two-dimensional k-leg loop-erased watermelon exponent ν is converting into the scaling exponent for the reunion probability (at a given point) of k(1+1)-dimensional vicious walkers, ν -tilde= k 2 /2. At the end, we express the conjectures about the possible relation to integrable systems

USING GENETIC ALGORTIHM TO SOLVE STEINER MINIMUM SPANNING TREE PROBLEM

Directory of Open Access Journals (Sweden)

Öznur İŞÇİ

2006-03-01

Full Text Available Genetic algorithms (GA are a stochastic research methods, and they produce solutions that are close to optimum or near optimum. In addition to GA's successful application to traveling salesman problem, square designation, allocation, workshop table, preparation of lesson/examination schedules, planning of communication networks, assembling line balanced, minimum spanning tree type many combinatorial optimization problems it would be applicable to make the best comparison in optimization. In this study a Java program is developed to solve Steiner minimum spanning tree problem by genetic algorithm and its performance is examined. According to the tests carried out on the problems that were given before in the literature, results that are close to optimum are obtained in by GA approach that is recommended in this study. For the predetermined points in the study, length and gain are calculated for Steiner minimum spanning tree problem and minimum spanning tree problem.

Structural Behavior of a Long-Span Partially Earth-Anchored Cable-Stayed Bridge during Installation of a Key Segment by Thermal Prestressing

Directory of Open Access Journals (Sweden)

Sang-Hyo Kim

2016-08-01

Full Text Available This study investigated structural behavior of long-span partially earth-anchored cable-stayed bridges with a main span length of 810 m that use a new key segment closing method based on a thermal prestressing technique. A detailed construction sequence analysis matched with the free cantilever method (FCM was performed using a three-dimensional finite element (FE model of a partially earth-anchored cable-stayed bridge. The new method offers an effective way of connecting key segments by avoiding large movements resulting from the removal of the longitudinal restraint owing to the asymmetry of axial forces in the girders near the pylons. The new method develops new member forces through the process of heating the cantilever system before installing the key segment and cooling the system continuously after installing key segments. The resulting forces developed by the thermal process enhance the structural behavior of partially earth-anchored cable-stayed bridges owing to decreased axial forces in the girders.

Machine-Learning Classifier for Patients with Major Depressive Disorder: Multifeature Approach Based on a High-Order Minimum Spanning Tree Functional Brain Network.

Science.gov (United States)

Guo, Hao; Qin, Mengna; Chen, Junjie; Xu, Yong; Xiang, Jie

2017-01-01

High-order functional connectivity networks are rich in time information that can reflect dynamic changes in functional connectivity between brain regions. Accordingly, such networks are widely used to classify brain diseases. However, traditional methods for processing high-order functional connectivity networks generally include the clustering method, which reduces data dimensionality. As a result, such networks cannot be effectively interpreted in the context of neurology. Additionally, due to the large scale of high-order functional connectivity networks, it can be computationally very expensive to use complex network or graph theory to calculate certain topological properties. Here, we propose a novel method of generating a high-order minimum spanning tree functional connectivity network. This method increases the neurological significance of the high-order functional connectivity network, reduces network computing consumption, and produces a network scale that is conducive to subsequent network analysis. To ensure the quality of the topological information in the network structure, we used frequent subgraph mining technology to capture the discriminative subnetworks as features and combined this with quantifiable local network features. Then we applied a multikernel learning technique to the corresponding selected features to obtain the final classification results. We evaluated our proposed method using a data set containing 38 patients with major depressive disorder and 28 healthy controls. The experimental results showed a classification accuracy of up to 97.54%.

Is the superior verbal memory span of Mandarin speakers due to faster rehearsal?

Science.gov (United States)

Mattys, Sven L; Baddeley, Alan; Trenkic, Danijela

2018-04-01

It is well established that digit span in native Chinese speakers is atypically high. This is commonly attributed to a capacity for more rapid subvocal rehearsal for that group. We explored this hypothesis by testing a group of English-speaking native Mandarin speakers on digit span and word span in both Mandarin and English, together with a measure of speed of articulation for each. When compared to the performance of native English speakers, the Mandarin group proved to be superior on both digit and word spans while predictably having lower spans in English. This suggests that the Mandarin advantage is not limited to digits. Speed of rehearsal correlated with span performance across materials. However, this correlation was more pronounced for English speakers than for any of the Chinese measures. Further analysis suggested that speed of rehearsal did not provide an adequate account of differences between Mandarin and English spans or for the advantage of digits over words. Possible alternative explanations are discussed.

Exploratory and problem-solving consumer behavior across the life span.

Science.gov (United States)

Lesser, J A; Kunkel, S R

1991-09-01

Different cognitive functioning, social, and personality changes appear to occur systematically during the adult life span. This article synthesizes research on life span changes in order to develop age-specific models of shopping behavior. The models are tested within a naturalistic field study of shoppers.

Life Span Extension and Neuronal Cell Protection by Drosophila Nicotinamidase*S⃞

OpenAIRE

Balan, Vitaly; Miller, Gregory S.; Kaplun, Ludmila; Balan, Karina; Chong, Zhao-Zhong; Li, Faqi; Kaplun, Alexander; VanBerkum, Mark F. A.; Arking, Robert; Freeman, D. Carl; Maiese, Kenneth; Tzivion, Guri

2008-01-01

The life span of model organisms can be modulated by environmental conditions that influence cellular metabolism, oxidation, or DNA integrity. The yeast nicotinamidase gene pnc1 was identified as a key transcriptional target and mediator of calorie restriction and stress-induced life span extension. PNC1 is thought to exert its effect on yeast life span by modulating cellular nicotinamide and NAD levels, resulting in increased activity of Sir2 family class III histone ...

A new fast algorithm for solving the minimum spanning tree problem based on DNA molecules computation.

Science.gov (United States)

Wang, Zhaocai; Huang, Dongmei; Meng, Huajun; Tang, Chengpei

2013-10-01

The minimum spanning tree (MST) problem is to find minimum edge connected subsets containing all the vertex of a given undirected graph. It is a vitally important NP-complete problem in graph theory and applied mathematics, having numerous real life applications. Moreover in previous studies, DNA molecular operations usually were used to solve NP-complete head-to-tail path search problems, rarely for NP-hard problems with multi-lateral path solutions result, such as the minimum spanning tree problem. In this paper, we present a new fast DNA algorithm for solving the MST problem using DNA molecular operations. For an undirected graph with n vertex and m edges, we reasonably design flexible length DNA strands representing the vertex and edges, take appropriate steps and get the solutions of the MST problem in proper length range and O(3m+n) time complexity. We extend the application of DNA molecular operations and simultaneity simplify the complexity of the computation. Results of computer simulative experiments show that the proposed method updates some of the best known values with very short time and that the proposed method provides a better performance with solution accuracy over existing algorithms. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Individual differences in personality change across the adult life span.

Science.gov (United States)

Schwaba, Ted; Bleidorn, Wiebke

2018-06-01

A precise and comprehensive description of personality continuity and change across the life span is the bedrock upon which theories of personality development are built. Little research has quantified the degree to which individuals deviate from mean-level developmental trends. In this study, we addressed this gap by examining individual differences in personality trait change across the life span. Data came from a nationally representative sample of 9,636 Dutch participants who provided Big Five self-reports at five assessment waves across 7 years. We divided our sample into 14 age groups (ages 16-84 at initial measurement) and estimated latent growth curve models to describe individual differences in personality change across the study period for each trait and age group. Across the adult life span, individual differences in personality change were small but significant until old age. For Openness, Conscientiousness, Extraversion, and Agreeableness, individual differences in change were most pronounced in emerging adulthood and decreased throughout midlife and old age. For Emotional Stability, individual differences in change were relatively consistent across the life span. These results inform theories of life span development and provide future directions for research on the causes and conditions of personality change. © 2017 Wiley Periodicals, Inc.

QCD and strongly coupled gauge theories: challenges and perspectives

CERN Document Server

Brambilla, N.; Foka, P.; Gardner, S.; Kronfeld, A.S.; Alford, M.G.; Alkofer, R.; Butenschoen, M.; Cohen, T.D.; Erdmenger, J.; Fabbietti, L.; Faber, M.; Goity, J.L.; Ketzer, B.; Lin, H.W.; Llanes-Estrada, F.J.; Meyer, H.B.; Pakhlov, P.; Pallante, E.; Polikarpov, M.I.; Sazdjian, H.; Schmitt, A.; Snow, W.M.; Vairo, A.; Vogt, R.; Vuorinen, A.; Wittig, H.; Arnold, P.; Christakoglou, P.; Di Nezza, P.; Fodor, Z.; Garcia i Tormo, X.; Hollwieser, R.; Janik, M.A.; Kalweit, A.; Keane, D.; Kiritsis, E.; Mischke, A.; Mizuk, R.; Odyniec, G.; Papadodimas, K.; Pich, A.; Pittau, R.; Qiu, J.W.; Ricciardi, G.; Salgado, C.A.; Schwenzer, K.; Stefanis, N.G.; von Hippel, G.M.; Zakharov, V.I.

2014-10-21

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly-coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.

Facilitating conditions for boundary-spanning behavior in governance networks

OpenAIRE

Meerkerk, Ingmar; Edelenbos, Jurian

2017-01-01

textabstractThis article examines the impact of two facilitating conditions for boundary-spanning behaviour in urban governance networks. While research on boundary spanning is growing, there is little attention for antecedents. Combining governance network literature on project management and organizational literature on facilitative and servant leadership, we examine two potential conditions: a facilitative project management style and executive support. We conducted survey research among p...

Minimal spanning trees, filaments and galaxy clustering

International Nuclear Information System (INIS)

Barrow, J.D.; Sonoda, D.H.

1985-01-01

A graph theoretical technique for assessing intrinsic patterns in point data sets is described. A unique construction, the minimal spanning tree, can be associated with any point data set given all the inter-point separations. This construction enables the skeletal pattern of galaxy clustering to be singled out in quantitative fashion and differs from other statistics applied to these data sets. This technique is described and applied to two- and three-dimensional distributions of galaxies and also to comparable random samples and numerical simulations. The observed CfA and Zwicky data exhibit characteristic distributions of edge-lengths in their minimal spanning trees which are distinct from those found in random samples. (author)

Understanding retirement: the promise of life-span developmental frameworks.

Science.gov (United States)

Löckenhoff, Corinna E

2012-09-01

The impending retirement of large population cohorts creates a pressing need for practical interventions to optimize outcomes at the individual and societal level. This necessitates comprehensive theoretical models that acknowledge the multi-layered nature of the retirement process and shed light on the dynamic mechanisms that drive longitudinal patterns of adjustment. The present commentary highlights ways in which contemporary life-span developmental frameworks can inform retirement research, drawing on the specific examples of Bronfenbrenner's Ecological Model, Baltes and Baltes Selective Optimization with Compensation Framework, Schulz and Heckhausen's Motivational Theory of Life-Span Development, and Carstensen's Socioemotional Selectivity Theory. Ultimately, a life-span developmental perspective on retirement offers not only new interpretations of known phenomena but may also help to identify novel directions for future research as well as promising pathways for interventions.

Strong Start Wraparound: Addressing the Complex Needs of Mothers in Early Recovery

Science.gov (United States)

Teel, M. Kay

2014-01-01

The Strong Start Study tested an innovative, High-Fidelity Wraparound intervention with families in early recovery from substance use. The Strong Start Wraparound model addressed the complex needs of pregnant and parenting women who were in early recovery to increase the protective factors of parental resilience, social connections, concrete…

Developmental Regulation across the Life Span: Toward a New Synthesis

Science.gov (United States)

Haase, Claudia M.; Heckhausen, Jutta; Wrosch, Carsten

2013-01-01

How can individuals regulate their own development to live happy, healthy, and productive lives? Major theories of developmental regulation across the life span have been proposed (e.g., dual-process model of assimilation and accommodation; motivational theory of life-span development; model of selection, optimization, and compensation), but they…

RESEARCH OF USING OPEN DOUBLE T BEAMS FOR SPANS IN FLOATING BRIDGES

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YU. M. Gorbatiuk

2014-03-01

Full Text Available Purpose. The publication presents the results of calculations of spans for floating bridges with open double T beams. The purpose of research is to analyze the suitability of spans from open double T beams for floating bridges with minimum weight under loads, which is provided by standards for modern floating bridges designing. Methodology. Comparative method, analytical calculation methods (influence lines methodology, strength calculations, endurance, maximum shear stress are used in this paper. Findings. Current loads for bridges calculations are 75% more than those, for which the spans of floating bridge from NZhM-56 property are designed. The use of open double T beams that is formed with double T beam no. 70 (the height of the open one is 104 cm reduces the cross sectional area in a weakened spot, but virtually it does not influence the strength and durability of the material. The use of open double T beams for spans of floating bridges saves up to 22 % of metal that means one in five spans will made of saved metal. Savings on each spans, such as CRP, will be 33.6 - 263 thous. grn. (considering the price of 1 ton of final product 29 thous. grn.. Originality. Research allows making next step in material saving and use of open double T beams for spans in the whole. Practical value. The obtained results give us possibility to make a number of conclusions that allow us to become more familiar and more practical with the use of open double T beams for spans of floating bridges.

Static behaviors of long-span cable-stayed bridge; Chodai shachokyo no seiteki kyodo ni kansuru kosatsu

Energy Technology Data Exchange (ETDEWEB)

Xie, Xu [Saitama Univ., Saitama (Japan). Graduate School; Yamaguchi, H.; Ito, M. [Saitama Univ., Urawa (Japan). Faculty of Engineering

1996-04-21

In this study, incremental equation of cable-stayed bridge is formulated by finite element method taking the geometrical nonlinear analysis into account. Then, as an example of designing a bridge with 1500m span, setting up the initial tension, analysis of in-plane behavior caused by live loads as well as analysis of the behavior against wind caused by out-of-plane wind load that are necessary for designing a bridge with 1500m span are carried out. The main results obtained through the study are as follows. As for the cable stayed bridge with 1500m center super long-span having supplementary supporting points between the side arms, the geometrical non-linearity caused by the in-plane design live loads is not remarkable. The effects of wind which acts on girders on analysis of the behaviors against wind are different depending on the aerodynamic performance of the girder and in the case of high wind speed, strong effects on the behavior against wind of the in-plane and screws generate. As the changing of tension of the cable makes influences on the force of in-plane cross section and on displacement of the girder, if the wind speed is very high, the analysis results of the behaviors against wind of in-plane and screws of the cable-stayed bridge may be different depending on in what manner the wind load on the cable to be treated. 16 refs., 16 figs., 1 tab.

Connecting Music, Art, and Science for Increased Creativity and Topic Engagement ?

OpenAIRE

McNealy, Tamara L.

2013-01-01

‘Attention spans have shortened,’ is a common phrase often used in reference to today’s college students. As faculty and instructors, we need to address this issue through the utilization of innovative and creative techniques that aid in making our subjects accessible to our students. Connecting a serious topic such as microbiology with a ‘fun’ activity can increase student engagement and learning. Ideas to maintain student attention on a subject include providing information in 15- to 20-min...

Increased Life Span due to Calorie Restriction in Respiratory-Deficient Yeast.

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2005-11-01

Full Text Available A model for replicative life span extension by calorie restriction (CR in yeast has been proposed whereby reduced glucose in the growth medium leads to activation of the NAD-dependent histone deacetylase Sir2. One mechanism proposed for this putative activation of Sir2 is that CR enhances the rate of respiration, in turn leading to altered levels of NAD or NADH, and ultimately resulting in enhanced Sir2 activity. An alternative mechanism has been proposed in which CR decreases levels of the Sir2 inhibitor nicotinamide through increased expression of the gene coding for nicotinamidase, PNC1. We have previously reported that life span extension by CR is not dependent on Sir2 in the long-lived BY4742 strain background. Here we have determined the requirement for respiration and the effect of nicotinamide levels on life span extension by CR. We find that CR confers robust life span extension in respiratory-deficient cells independent of strain background, and moreover, suppresses the premature mortality associated with loss of mitochondrial DNA in the short-lived PSY316 strain. Addition of nicotinamide to the medium dramatically shortens the life span of wild type cells, due to inhibition of Sir2. However, even in cells lacking both Sir2 and the replication fork block protein Fob1, nicotinamide partially prevents life span extension by CR. These findings (1 demonstrate that respiration is not required for the longevity benefits of CR in yeast, (2 show that nicotinamide inhibits life span extension by CR through a Sir2-independent mechanism, and (3 suggest that CR acts through a conserved, Sir2-independent mechanism in both PSY316 and BY4742.

Increased life span due to calorie restriction in respiratory-deficient yeast.

Directory of Open Access Journals (Sweden)

Matt Kaeberlein

2005-11-01

Full Text Available A model for replicative life span extension by calorie restriction (CR in yeast has been proposed whereby reduced glucose in the growth medium leads to activation of the NAD+-dependent histone deacetylase Sir2. One mechanism proposed for this putative activation of Sir2 is that CR enhances the rate of respiration, in turn leading to altered levels of NAD+ or NADH, and ultimately resulting in enhanced Sir2 activity. An alternative mechanism has been proposed in which CR decreases levels of the Sir2 inhibitor nicotinamide through increased expression of the gene coding for nicotinamidase, PNC1. We have previously reported that life span extension by CR is not dependent on Sir2 in the long-lived BY4742 strain background. Here we have determined the requirement for respiration and the effect of nicotinamide levels on life span extension by CR. We find that CR confers robust life span extension in respiratory-deficient cells independent of strain background, and moreover, suppresses the premature mortality associated with loss of mitochondrial DNA in the short-lived PSY316 strain. Addition of nicotinamide to the medium dramatically shortens the life span of wild type cells, due to inhibition of Sir2. However, even in cells lacking both Sir2 and the replication fork block protein Fob1, nicotinamide partially prevents life span extension by CR. These findings (1 demonstrate that respiration is not required for the longevity benefits of CR in yeast, (2 show that nicotinamide inhibits life span extension by CR through a Sir2-independent mechanism, and (3 suggest that CR acts through a conserved, Sir2-independent mechanism in both PSY316 and BY4742.

Boundary Spanning in Higher Education: How Universities Can Enable Success

Science.gov (United States)

Skolaski, Jennifer Pauline

2012-01-01

Purpose: The purpose of this research is to better understand the identity and work of academic and extension staff who have boundary spanning responsibilities. The results will help universities, especially public land-grant universities with an outreach mission, to create stronger policies and systems to support boundary spanning staff members…

Dynamic functional connectivity analysis reveals transient states of dysconnectivity in schizophrenia

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E. Damaraju

2014-01-01

Full Text Available Schizophrenia is a psychotic disorder characterized by functional dysconnectivity or abnormal integration between distant brain regions. Recent functional imaging studies have implicated large-scale thalamo-cortical connectivity as being disrupted in patients. However, observed connectivity differences in schizophrenia have been inconsistent between studies, with reports of hyperconnectivity and hypoconnectivity between the same brain regions. Using resting state eyes-closed functional imaging and independent component analysis on a multi-site data that included 151 schizophrenia patients and 163 age- and gender matched healthy controls, we decomposed the functional brain data into 100 components and identified 47 as functionally relevant intrinsic connectivity networks. We subsequently evaluated group differences in functional network connectivity, both in a static sense, computed as the pairwise Pearson correlations between the full network time courses (5.4 minutes in length, and a dynamic sense, computed using sliding windows (44 s in length and k-means clustering to characterize five discrete functional connectivity states. Static connectivity analysis revealed that compared to healthy controls, patients show significantly stronger connectivity, i.e., hyperconnectivity, between the thalamus and sensory networks (auditory, motor and visual, as well as reduced connectivity (hypoconnectivity between sensory networks from all modalities. Dynamic analysis suggests that (1, on average, schizophrenia patients spend much less time than healthy controls in states typified by strong, large-scale connectivity, and (2, that abnormal connectivity patterns are more pronounced during these connectivity states. In particular, states exhibiting cortical–subcortical antagonism (anti-correlations and strong positive connectivity between sensory networks are those that show the group differences of thalamic hyperconnectivity and sensory hypoconnectivity

Selectivity and sparseness in randomly connected balanced networks.

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Cengiz Pehlevan

Full Text Available Neurons in sensory cortex show stimulus selectivity and sparse population response, even in cases where no strong functionally specific structure in connectivity can be detected. This raises the question whether selectivity and sparseness can be generated and maintained in randomly connected networks. We consider a recurrent network of excitatory and inhibitory spiking neurons with random connectivity, driven by random projections from an input layer of stimulus selective neurons. In this architecture, the stimulus-to-stimulus and neuron-to-neuron modulation of total synaptic input is weak compared to the mean input. Surprisingly, we show that in the balanced state the network can still support high stimulus selectivity and sparse population response. In the balanced state, strong synapses amplify the variation in synaptic input and recurrent inhibition cancels the mean. Functional specificity in connectivity emerges due to the inhomogeneity caused by the generative statistical rule used to build the network. We further elucidate the mechanism behind and evaluate the effects of model parameters on population sparseness and stimulus selectivity. Network response to mixtures of stimuli is investigated. It is shown that a balanced state with unselective inhibition can be achieved with densely connected input to inhibitory population. Balanced networks exhibit the "paradoxical" effect: an increase in excitatory drive to inhibition leads to decreased inhibitory population firing rate. We compare and contrast selectivity and sparseness generated by the balanced network to randomly connected unbalanced networks. Finally, we discuss our results in light of experiments.

A pluggable service platform architecture for e-commercspan>e

NARCIS (Netherlands)

Aulkemeier, Fabian; Paramartha, Mohammad Anggasta; Iacob, Maria Eugenia; van Hillegersberg, Jos

2016-01-01

In the beginning of the e-commercspan>e era, retailers mostly adopted vertically integrated solutions to control the entire e-commercspan>e value chain. However, they began to realize that to achieve agility, a better approach would be to focus on certain core capabilities and then create a partner ecosystem

Implications of e-commercspan>e for banking and finance

NARCIS (Netherlands)

Heng, Michael S.H.

2001-01-01

The aim of the paper is to show that e-commercspan>e holds the potential totransform banking and financial systems. There are three aspects in which e-commercecan affect banking and finance. First, banks and financial firms can use thetechnology and business practice of e-commercspan>e to market their

The brain matures with stronger functional connectivity and decreased randomness of its network.

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Dirk J A Smit

Full Text Available We investigated the development of the brain's functional connectivity throughout the life span (ages 5 through 71 years by measuring EEG activity in a large population-based sample. Connectivity was established with Synchronization Likelihood. Relative randomness of the connectivity patterns was established with Watts and Strogatz' (1998 graph parameters C (local clustering and L (global path length for alpha (~10 Hz, beta (~20 Hz, and theta (~4 Hz oscillation networks. From childhood to adolescence large increases in connectivity in alpha, theta and beta frequency bands were found that continued at a slower pace into adulthood (peaking at ~50 yrs. Connectivity changes were accompanied by increases in L and C reflecting decreases in network randomness or increased order (peak levels reached at ~18 yrs. Older age (55+ was associated with weakened connectivity. Semi-automatically segmented T1 weighted MRI images of 104 young adults revealed that connectivity was significantly correlated to cerebral white matter volume (alpha oscillations: r = 33, p<01; theta: r = 22, p<05, while path length was related to both white matter (alpha: max. r = 38, p<001 and gray matter (alpha: max. r = 36, p<001; theta: max. r = 36, p<001 volumes. In conclusion, EEG connectivity and graph theoretical network analysis may be used to trace structural and functional development of the brain.

Differential structural and resting state connectivity between insular subdivisions and other pain-related brain regions.

Science.gov (United States)

Wiech, K; Jbabdi, S; Lin, C S; Andersson, J; Tracey, I

2014-10-01

Functional neuroimaging studies suggest that the anterior, mid, and posterior division of the insula subserve different functions in the perception of pain. The anterior insula (AI) has predominantly been associated with cognitive-affective aspects of pain, while the mid and posterior divisions have been implicated in sensory-discriminative processing. We examined whether this functional segregation is paralleled by differences in (1) structural and (2) resting state connectivity and (3) in correlations with pain-relevant psychological traits. Analyses were restricted to the 3 insular subdivisions and other pain-related brain regions. Both type of analyses revealed largely overlapping results. The AI division was predominantly connected to the ventrolateral prefrontal cortex (structural and resting state connectivity) and orbitofrontal cortex (structural connectivity). In contrast, the posterior insula showed strong connections to the primary somatosensory cortex (SI; structural connectivity) and secondary somatosensory cortex (SII; structural and resting state connectivity). The mid insula displayed a hybrid connectivity pattern with strong connections with the ventrolateral prefrontal cortex, SII (structural and resting state connectivity) and SI (structural connectivity). Moreover, resting state connectivity revealed strong connectivity of all 3 subdivisions with the thalamus. On the behavioural level, AI structural connectivity was related to the individual degree of pain vigilance and awareness that showed a positive correlation with AI-amygdala connectivity and a negative correlation with AI-rostral anterior cingulate cortex connectivity. In sum, our findings show a differential structural and resting state connectivity for the anterior, mid, and posterior insula with other pain-relevant brain regions, which might at least partly explain their different functional profiles in pain processing. Copyright © 2014 The Authors. Published by Elsevier B.V. All

The Role of Covert Retrieval in Working Memory Span Tasks: Evidence from Delayed Recall Tests

Science.gov (United States)

McCabe, David P.

2008-01-01

The current study examined delayed recall of items that had been processed during simple and complex span tasks. Three experiments were reported showing that despite more items being recalled initially from a simple span task (i.e., word span) than a complex span task (i.e., operation span), on a delayed recall test more items were recalled that…

Connecting and disconnecting nematic disclination lines in microfluidic channels.

Science.gov (United States)

Agha, Hakam; Bahr, Christian

2016-05-14

Disclination lines in nematic liquid crystals can be used as "soft rails" for the transport of colloids or droplets through microfluidic channels [A. Sengupta, C. Bahr and S. Herminghaus, Soft Matter, 2013, 9, 7251]. In the present study we report on a method to connect and disconnect disclination lines in microfluidic channels using the interplay between anchoring, flow, and electric field. We show that the application of an electric field establishes a continuous disclination that spans across a channel region in which a disclination usually would not exist (because of different anchoring conditions), demonstrating an interruptible and reconnectable soft rail for colloidal transport.

Paternal smoking habits affect the reproductive life span of daughters

DEFF Research Database (Denmark)

Fukuda, Misao; Fukuda, Kiyomi; Shimizu, Takashi

2011-01-01

The present study assessed whether the smoking habits of fathers around the time of conception affected the period in which daughters experienced menstrual cycles (i.e., the reproductive life span). The study revealed that the smoking habits of the farther shortened the daughters' reproductive life...... span compared with daughters whose fathers did not smoke....

On the number of spanning trees in random regular graphs

DEFF Research Database (Denmark)

Greenhill, Catherine; Kwan, Matthew; Wind, David Kofoed

2014-01-01

Let d >= 3 be a fixed integer. We give an asympotic formula for the expected number of spanning trees in a uniformly random d-regular graph with n vertices. (The asymptotics are as n -> infinity, restricted to even n if d is odd.) We also obtain the asymptotic distribution of the number of spanning...

Cerebro-cerebellar connectivity is increased in primary lateral sclerosis.

Science.gov (United States)

Meoded, Avner; Morrissette, Arthur E; Katipally, Rohan; Schanz, Olivia; Gotts, Stephen J; Floeter, Mary Kay

2015-01-01

Increased functional connectivity in resting state networks was found in several studies of patients with motor neuron disorders, although diffusion tensor imaging studies consistently show loss of white matter integrity. To understand the relationship between structural connectivity and functional connectivity, we examined the structural connections between regions with altered functional connectivity in patients with primary lateral sclerosis (PLS), a long-lived motor neuron disease. Connectivity matrices were constructed from resting state fMRI in 16 PLS patients to identify areas of differing connectivity between patients and healthy controls. Probabilistic fiber tracking was used to examine structural connections between regions of differing connectivity. PLS patients had 12 regions with increased functional connectivity compared to controls, with a predominance of cerebro-cerebellar connections. Increased functional connectivity was strongest between the cerebellum and cortical motor areas and between the cerebellum and frontal and temporal cortex. Fiber tracking detected no difference in connections between regions with increased functional connectivity. We conclude that functional connectivity changes are not strongly based in structural connectivity. Increased functional connectivity may be caused by common inputs, or by reduced selectivity of cortical activation, which could result from loss of intracortical inhibition when cortical afferents are intact.

Time-varying span efficiency through the wingbeat of desert locusts.

Science.gov (United States)

Henningsson, Per; Bomphrey, Richard J

2012-06-07

The flight performance of animals depends greatly on the efficacy with which they generate aerodynamic forces. Accordingly, maximum range, load-lifting capacity and peak accelerations during manoeuvres are all constrained by the efficiency of momentum transfer to the wake. Here, we use high-speed particle image velocimetry (1 kHz) to record flow velocities in the near wake of desert locusts (Schistocerca gregaria, Forskål). We use the measured flow fields to calculate time-varying span efficiency throughout the wing stroke cycle. The locusts are found to operate at a maximum span efficiency of 79 per cent, typically at a plateau of about 60 per cent for the majority of the downstroke, but at lower values during the upstroke. Moreover, the calculated span efficiencies are highest when the largest lift forces are being generated (90% of the total lift is generated during the plateau of span efficiency) suggesting that the combination of wing kinematics and morphology in locust flight perform most efficiently when doing the most work.

Life Span Extension and Neuronal Cell Protection by Drosophila Nicotinamidase*S⃞

Science.gov (United States)

Balan, Vitaly; Miller, Gregory S.; Kaplun, Ludmila; Balan, Karina; Chong, Zhao-Zhong; Li, Faqi; Kaplun, Alexander; VanBerkum, Mark F. A.; Arking, Robert; Freeman, D. Carl; Maiese, Kenneth; Tzivion, Guri

2008-01-01

The life span of model organisms can be modulated by environmental conditions that influence cellular metabolism, oxidation, or DNA integrity. The yeast nicotinamidase gene pnc1 was identified as a key transcriptional target and mediator of calorie restriction and stress-induced life span extension. PNC1 is thought to exert its effect on yeast life span by modulating cellular nicotinamide and NAD levels, resulting in increased activity of Sir2 family class III histone deacetylases. In Caenorhabditis elegans, knockdown of a pnc1 homolog was shown recently to shorten the worm life span, whereas its overexpression increased survival under conditions of oxidative stress. The function and regulation of nicotinamidases in higher organisms has not been determined. Here, we report the identification and biochemical characterization of the Drosophila nicotinamidase, D-NAAM, and demonstrate that its overexpression significantly increases median and maximal fly life span. The life span extension was reversed in Sir2 mutant flies, suggesting Sir2 dependence. Testing for physiological effectors of D-NAAM in Drosophila S2 cells, we identified oxidative stress as a primary regulator, both at the transcription level and protein activity. In contrast to the yeast model, stress factors such as high osmolarity and heat shock, calorie restriction, or inhibitors of TOR and phosphatidylinositol 3-kinase pathways do not appear to regulate D-NAAM in S2 cells. Interestingly, the expression of D-NAAM in human neuronal cells conferred protection from oxidative stress-induced cell death in a sirtuin-dependent manner. Together, our findings establish a life span extending the ability of nicotinamidase in flies and offer a role for nicotinamide-modulating genes in oxidative stress regulated pathways influencing longevity and neuronal cell survival. PMID:18678867

Evidence for deficits in the temporal attention span of poor readers.

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Troy A W Visser

Full Text Available While poor reading is often associated with phonological deficits, many studies suggest that visual processing might also be impaired. In particular, recent research has indicated that poor readers show impaired spatial visual attention spans in partial and whole report tasks. Given the similarities between competition-based accounts for reduced visual attention span and similar explanations for impairments in sequential object processing, the present work examined whether poor readers show deficits in their "temporal attention span"--that is, their ability to rapidly and accurately process sequences of consecutive target items.Poor and normal readers monitored a sequential stream of visual items for two (TT condition or three (TTT condition consecutive target digits. Target identification was examined using both unconditional and conditional measures of accuracy in order to gauge the overall likelihood of identifying a target and the likelihood of identifying a target given successful identification of previous items. Compared to normal readers, poor readers showed small but consistent deficits in identification across targets whether unconditional or conditional accuracy was used. Additionally, in the TTT condition, final-target conditional accuracy was poorer than unconditional accuracy, particularly for poor readers, suggesting a substantial cost arising from processing the previous two targets that was not present in normal readers.Mirroring the differences found between poor and normal readers in spatial visual attention span, the present findings suggest two principal differences between the temporal attention spans of poor and normal readers. First, the consistent pattern of reduced performance across targets suggests increased competition amongst items within the same span for poor readers. Second, the steeper decline in final target performance amongst poor readers in the TTT condition suggests a reduction in the extent of their

Evidence for deficits in the temporal attention span of poor readers.

Science.gov (United States)

Visser, Troy A W

2014-01-01

While poor reading is often associated with phonological deficits, many studies suggest that visual processing might also be impaired. In particular, recent research has indicated that poor readers show impaired spatial visual attention spans in partial and whole report tasks. Given the similarities between competition-based accounts for reduced visual attention span and similar explanations for impairments in sequential object processing, the present work examined whether poor readers show deficits in their "temporal attention span"--that is, their ability to rapidly and accurately process sequences of consecutive target items. Poor and normal readers monitored a sequential stream of visual items for two (TT condition) or three (TTT condition) consecutive target digits. Target identification was examined using both unconditional and conditional measures of accuracy in order to gauge the overall likelihood of identifying a target and the likelihood of identifying a target given successful identification of previous items. Compared to normal readers, poor readers showed small but consistent deficits in identification across targets whether unconditional or conditional accuracy was used. Additionally, in the TTT condition, final-target conditional accuracy was poorer than unconditional accuracy, particularly for poor readers, suggesting a substantial cost arising from processing the previous two targets that was not present in normal readers. Mirroring the differences found between poor and normal readers in spatial visual attention span, the present findings suggest two principal differences between the temporal attention spans of poor and normal readers. First, the consistent pattern of reduced performance across targets suggests increased competition amongst items within the same span for poor readers. Second, the steeper decline in final target performance amongst poor readers in the TTT condition suggests a reduction in the extent of their temporal attention

Spanning the Home/Work Creative Space

DEFF Research Database (Denmark)

Davis, Lee N.; Davis, Jerome; Hoisl, Karin

the employee brings to work. Based on Woodman et al.’s (1993) “interactionist perspective” on organizational creativity, supplemented by literature on search and knowledge re/combination, we explore whether and how leisure time activities can span the creative space between the employee’s home and workplace...

[Survey on menopausal age and menstruation span in women in Pudong district of Shanghai].

Science.gov (United States)

Chen, Hua; Feng, You-ji; Shu, Hui-min; Lu, Tian-mei; Zhu, Hong-mei; Yang, Bin-lie; Xiong, Miao

2010-06-01

To investigate natural spontaneous menopausal age, menstruation span and their relationship with menarche age and parity in Pudong district of Shanghai. From Jan 2007 to Jul 2008, 15 083 spontaneous menopause women undergoing cervical cancer screening were enrolled in this study. The questionnaire included menarche age, parity, spontaneous menopausal age and menstruation span. Those women were divided into four groups based on age, which were group of 56 - 60, 61 - 65, 66 - 70 and more than 70.Analysis of variance (ANOVA) was used for comparing difference between menopausal age and menstruation span. Multiple factor regressions was used to analyze the relationship between menarche age, parity and menopausal age and menstruation span. (1) Spontaneous menopausal age: the minimum was 29 years old, the maximum was 61 years old, and the mean age was (50.6 ± 3.7) years old. The mean spontaneous menopause age were (50.9 ± 3.4), (50.7 ± 3.7), (50.0 ± 4.1), (49.6 ± 4.0) years in groups of 56 - 60, 61 - 65, 66 - 70 and more than 70 years. With the increasing age range in four groups, the increasing trends of menopausal age were observed, which the difference of 1.36 year was shown between groups of 56 - 60 and more than 70 years. (2) Menstruation span: the mean of menstruation span was (34.3 ± 4.1) years, which the minimal age of 12 years and maximal age of 48 years were recorded. (34.6 ± 3.8), (34.3 ± 4.1), (33.9 ± 4.6), (33.2 ± 4.5) were observed in groups of 56 - 60, 61 - 65, 66 - 70 and more than 70 years. With the increasing age range in four groups, the increasing trends of menstruation span were observed, which the difference of 1.41 year was shown between groups of 56 - 60 and more than 70 years. (3) The impact of menarche age on menopausal age and menstruation span: there was no correlation between menarche age and menopausal age (r = 0.02); however, menstruation span was found to be negatively correlated with the menarche age (r = -0.43). (4) The impact

Emotional Egocentricity Bias across the life-span

Directory of Open Access Journals (Sweden)

Federica eRiva

2016-04-01

Full Text Available In our daily lives, we often have to quickly estimate the emotions of our conspecifics in order to have successful social interactions. While this estimation process seems quite easy when we are ourselves in a neutral or equivalent emotional state, it has recently been shown that in case of incongruent emotional states between ourselves and the others, our judgments can be biased. This phenomenon, introduced to the literature with the term Emotional Egocentricity Bias (EEB, has been found to occur in young adults and, to a greater extent, in children. However, how EEB changes across the life-span from adolescence to old age has been largely unexplored. In this study, we recruited 114 female participants subdivided in four cohorts (adolescents, young adults, middle-aged adults, older adults to examine EEB age-related changes. Participants were administered with a paradigm which, by making use of visuo-tactile stimulation that elicits conflicting feelings in paired participants, allows the valid and reliable exploration of EEB. Results highlighted a U-shaped relation between age and EEB, revealing higher emotional egocentricity in adolescents and older adults compared to young and middle-aged adults. These results are in line with the neuroscientific literature which has recently shown that overcoming EEB is associated with a greater activation of a portion of the parietal lobe, namely the right Supramarginal Gyrus (rSMG. This is an area that reaches full maturation only by the end of adolescence, and displays an early decay in older age. Thus, the age-related changes of the EEB could be possibly due to the life-span development of the rSMG. This study is the first one to show the quadratic relation between age and the EEB and set a milestone for further research exploring the neural correlates of the life-span development of the EEB. Future studies are needed in order to generalize these results to the male population and to explore gender

Interorganizational Boundary Spanning in Global Software Development

DEFF Research Database (Denmark)

Søderberg, Anne-Marie; Romani, Laurence

, and which skills and competencies they draw on in their efforts to deal with emerging cross-cultural issues in a way that paves ground for developing a shared understanding and common platform for the client and vendor representatives. A framework of boundary spanning leadership practices is adapted...... to virtuality and cultural diversity. This paper, which draws on a case study of collaborative work in a global software development project, focuses on key boundary spanners in an Indian vendor company, who are responsible for developing trustful and sustainable client relations and coordinating complex...... projects across multiple cultures, languages, organisational boundaries, time zones and geographical distances. It looks into how these vendor managers get prepared for their complex boundary spanning work, which cross-cultural challenges they experience in their collaboration with Western clients...

Synchronization from second order network connectivity statistics

Directory of Open Access Journals (Sweden)

Liqiong eZhao

2011-07-01

Full Text Available We investigate how network structure can influence the tendency for a neuronal network to synchronize, or its synchronizability, independent of the dynamical model for each neuron. The synchrony analysis takes advantage of the framework of second order networks (SONETs, which defines four second order connectivity statistics based on the relative frequency of two-connection network motifs. The analysis identifies two of these statistics, convergent connections and chain connections, as highly influencing the synchrony. Simulations verify that synchrony decreases with the frequency of convergent connections and increases with the frequency of chain connections. These trends persist with simulations of multiple models for the neuron dynamics and for different types of networks. Surprisingly, divergent connections, which determine the fraction of shared inputs, do not strongly influence the synchrony. The critical role of chains, rather than divergent connections, in influencing synchrony can be explained by a pool and redistribute mechanism. The pooling of many inputs averages out independent fluctuations, amplifying weak correlations in the inputs. With increased chain connections, neurons with many inputs tend to have many outputs. Hence, chains ensure that the amplified correlations in the neurons with many inputs are redistributed throughout the network, enhancing the development of synchrony across the network.

The Influence of Dietary Fat Source on Life Span in Calorie Restricted Mice.

Science.gov (United States)

López-Domínguez, José A; Ramsey, Jon J; Tran, Dianna; Imai, Denise M; Koehne, Amanda; Laing, Steven T; Griffey, Stephen M; Kim, Kyoungmi; Taylor, Sandra L; Hagopian, Kevork; Villalba, José M; López-Lluch, Guillermo; Navas, Plácido; McDonald, Roger B

2015-10-01

Calorie restriction (CR) without malnutrition extends life span in several animal models. It has been proposed that a decrease in the amount of polyunsaturated fatty acids (PUFAs), and especially n-3 fatty acids, in membrane phospholipids may contribute to life span extension with CR. Phospholipid PUFAs are sensitive to dietary fatty acid composition, and thus, the purpose of this study was to determine the influence of dietary lipids on life span in CR mice. C57BL/6J mice were assigned to four groups (a 5% CR control group and three 40% CR groups) and fed diets with soybean oil (high in n-6 PUFAs), fish oil (high in n-3 PUFAs), or lard (high in saturated and monounsaturated fatty acids) as the primary lipid source. Life span was increased (p Life span was also increased (p life span in mice on CR, and suggest that a diet containing a low proportion of PUFAs and high proportion of monounsaturated and saturated fats may maximize life span in animals maintained on CR. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The relationship between short-term memory and working memory: complex span made simple?

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Bayliss, Donna M; Jarrold, Christopher; Baddeley, Alan D; Gunn, Deborah M

2005-01-01

This experiment addresses the question of what makes a working memory measure a good predictor of higher-level abilities. Verbal and visuospatial processing episodes were interleaved with distinct verbal and visuospatial storage episodes to form four complex span tasks. Although these measures were reliable predictors of reading and mathematics ability in children, they were no more predictive of these abilities than corresponding simple span tasks involving storage alone. However, when individual differences in storage ability and processing capacity were controlled for, residual variance in complex span performance was related to academic ability in some cases. These findings indicate that complex span tasks are multiply determined, and that differences in task structure can dramatically influence the relative importance of these multiple constraints and the predictive power of a complex span measure.

On interrelations of recurrences and connectivity trends between stock indices

Science.gov (United States)

Goswami, B.; Ambika, G.; Marwan, N.; Kurths, J.

2012-09-01

Financial data has been extensively studied for correlations using Pearson's cross-correlation coefficient ρ as the point of departure. We employ an estimator based on recurrence plots - the correlation of probability of recurrence (CPR) - to analyze connections between nine stock indices spread worldwide. We suggest a slight modification of the CPR approach in order to get more robust results. We examine trends in CPR for an approximately 19-month window moved along the time series and compare them to trends in ρ. Binning CPR into three levels of connectedness (strong, moderate, and weak), we extract the trends in number of connections in each bin over time. We also look at the behavior of CPR during the dot-com bubble by shifting the time series to align their peaks. CPR mainly uncovers that the markets move in and out of periods of strong connectivity erratically, instead of moving monotonically towards increasing global connectivity. This is in contrast to ρ, which gives a picture of ever-increasing correlation. CPR also exhibits that time-shifted markets have high connectivity around the dot-com bubble of 2000. We use significance tests using twin surrogates to interpret all the measures estimated in the study.

1-Skeletons of the Spanning Tree Problems with Additional Constraints

Directory of Open Access Journals (Sweden)

V. A. Bondarenko

2015-01-01

Full Text Available In this paper, we study polyhedral properties of two spanning tree problems with additional constraints. In the first problem, it is required to find a tree with a minimum sum of edge weights among all spanning trees with the number of leaves less than or equal to a given value. In the second problem, an additional constraint is the assumption that the degree of all nodes of the spanning tree does not exceed a given value. The recognition versions of both problems are NP-complete. We consider polytopes of these problems and their 1-skeletons. We prove that in both cases it is a NP-complete problem to determine whether the vertices of 1-skeleton are adjacent. Although it is possible to obtain a superpolynomial lower bounds on the clique numbers of these graphs. These values characterize the time complexity in a broad class of algorithms based on linear comparisons. The results indicate a fundamental difference between combinatorial and geometric properties of the considered problems from the classical minimum spanning tree problem.

The visual attention span deficit in dyslexia is visual and not verbal.

Science.gov (United States)

Lobier, Muriel; Zoubrinetzky, Rachel; Valdois, Sylviane

2012-06-01

The visual attention (VA) span deficit hypothesis of dyslexia posits that letter string deficits are a consequence of impaired visual processing. Alternatively, some have interpreted this deficit as resulting from a visual-to-phonology code mapping impairment. This study aims to disambiguate between the two interpretations by investigating performance in a non-verbal character string visual categorization task with verbal and non-verbal stimuli. Results show that VA span ability predicts performance for the non-verbal visual processing task in normal reading children. Furthermore, VA span impaired dyslexic children are also impaired for the categorization task independently of stimuli type. This supports the hypothesis that the underlying impairment responsible for the VA span deficit is visual, not verbal. Copyright © 2011 Elsevier Srl. All rights reserved.

Crosstalk performance of integrated optical cross-connects

NARCIS (Netherlands)

Herben, C.G.P.; Leijtens, X.J.M.; Maat, D.H.P.; Blok, H.; Smit, M.K.

1999-01-01

Crosstalk performance of monolithically integrated multiwavelength optical cross-connects (OXC's) depends strongly on their architecture. In this paper, a semiquantitative analysis of crosstalk in 11 different architectures is presented. Two architectures are analyzed numerically in more detail and

The effects of age on processing and storage in working memory span tasks and reading comprehension.

Science.gov (United States)

Schroeder, Paul J

2014-01-01

BACKGROUND/STUDY CONTEXT: Declines in verbal working memory span task performance have been associated with deficits in the language processing abilities of healthy older adults, but it is unclear how storage and processing contribute to this relationship. Moreover, recent studies of the psychometric properties of span measures in the general cognitive literature highlight the need for a critical reassessment of age-related differences in working memory task performance. Forty-two young (Mage = 19.45 years) and 42 older participants (Mage = 73.00 years) completed a series of neuropsychological screening measures, four memory span tasks (one-syllable word span, three-syllable word span, reading span, and sentence span), and a measure of reading comprehension. Each span measure was completed under self-paced and timed encoding conditions. A 2 (age) × 2 (task type) × 2 (encoding conditions) mixed-model design was used. (1) Age effects were reliable for both simple and complex span task performance; (2) limiting the available encoding time yielded lower recall scores across tasks and exacerbated age differences in simple span performance; and (3) both encoding condition and age affected the relationship between each of the span measures and the relationship between span and reading comprehension. Declines in both storage and processing abilities contributed to age differences in span task performance and the relationship between span and reading comprehension. Although older people appear to benefit from task administration protocols that promote successful memory encoding, researchers should be aware of the potential risks to validity posed by such accommodations.

Relations between Preschool Attention Span-Persistence and Age 25 Educational Outcomes

Science.gov (United States)

McClelland, Megan M.; Acock, Alan C.; Piccinin, Andrea; Rhea, Sally Ann; Stallings, Michael C.

2013-01-01

This study examined relations between children's attention span-persistence in preschool and later school achievement and college completion. Children were drawn from the Colorado Adoption Project using adopted and non-adopted children (N = 430). Results of structural equation modeling indicated that children's age 4 attention span-persistence…

Faster Fully-Dynamic minimum spanning forest

DEFF Research Database (Denmark)

Holm, Jacob; Rotenberg, Eva; Wulff-Nilsen, Christian

2015-01-01

We give a new data structure for the fully-dynamic minimum spanning forest problem in simple graphs. Edge updates are supported in O(log4 n/log logn) expected amortized time per operation, improving the O(log4 n) amortized bound of Holm et al. (STOC’98, JACM’01).We also provide a deterministic data...

Plasmons in strong superconductors

International Nuclear Information System (INIS)

Baldo, M.; Ducoin, C.

2011-01-01

We present a study of the possible plasmon excitations that can occur in systems where strong superconductivity is present. In these systems the plasmon energy is comparable to or smaller than the pairing gap. As a prototype of these systems we consider the proton component of Neutron Star matter just below the crust when electron screening is not taken into account. For the realistic case we consider in detail the different aspects of the elementary excitations when the proton, electron components are considered within the Random-Phase Approximation generalized to the superfluid case, while the influence of the neutron component is considered only at qualitative level. Electron screening plays a major role in modifying the proton spectrum and spectral function. At the same time the electron plasmon is strongly modified and damped by the indirect coupling with the superfluid proton component, even at moderately low values of the gap. The excitation spectrum shows the interplay of the different components and their relevance for each excitation modes. The results are relevant for neutrino physics and thermodynamical processes in neutron stars. If electron screening is neglected, the spectral properties of the proton component show some resemblance with the physical situation in high-T c superconductors, and we briefly discuss similarities and differences in this connection. In a general prospect, the results of the study emphasize the role of Coulomb interaction in strong superconductors.

Structure-borne low-frequency noise from multi-span bridges: A prediction method and spatial distribution

Science.gov (United States)

Song, X. D.; Wu, D. J.; Li, Q.; Botteldooren, D.

2016-04-01

Structure-borne noise from railway bridges at far-field points is an important indicator in environmental noise assessment. However, studies that predict structure-borne noise tend to model only single-span bridges, thus ignoring the sound pressure radiating from adjacent spans. To simulate the noise radiating from multi-span bridges induced by moving vehicles, the vibrations of a multi-span bridge are first obtained from a three-dimensional (3D) vehicle-track-bridge dynamic interaction simulation using the mode superposition method. A procedure based on the 2.5-dimensional (2.5D) boundary element method (BEM) is then presented to promote the efficiency of acoustical computation compared with the 3D BEM. The simulated results obtained from both the single-span and multi-span bridge models are compared with the measured results. The sound predictions calculated from the single-span model are accurate only for a minority of near-field points. In contrast, the sound pressures calculated from the multi-span bridge model match the measured results in both the time and frequency domains for all of the near-field and far-field points. The number of bridge spans required in the noise simulation is then recommended related to the distance between the track center and the field points of interest. The spatial distribution of multi-span structure-borne noise is also studied. The variation in sound pressure levels is insignificant along the length of the bridge, which validates the finding that the sound test section can be selected at an arbitrary plane perpendicular to the multi-span bridge.

Functional connectivity metrics during stroke recovery

DEFF Research Database (Denmark)

Yourganov, Grigori; Schmah, Tanya; Small, Steven L.

2010-01-01

We explore functional connectivity in nine subjects measured with 1 5T fMRI-BOLD in a longitudinal study of recovery from unilateral stroke affecting the motor area (Small et al, 2002) We found that several measures of complexity of covariance matrices show strong correlations with behavioral mea...

Propagation of strong electromagnetic beams in inhomogeneous plasmas

Energy Technology Data Exchange (ETDEWEB)

Ferrari, A; Massaglia, S [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Turin Univ. (Italy). Ist. di Fisica Generale)

1980-09-01

We study some simple aspects of nonlinear propagation of relativistically strong electromagnetic beams in inhomogeneous plasmas, especially in connection with effects of beam self-trapping in extended extragalactic radio sources. The two effects of (i) long scale longitudinal and radial inhomogeneities inherent to the plasma and (ii) radial inhomogeneities produced by the ponderomotive force of the beam itself are investigated.

Attractor neural networks with resource-efficient synaptic connectivity

Science.gov (United States)

Pehlevan, Cengiz; Sengupta, Anirvan

Memories are thought to be stored in the attractor states of recurrent neural networks. Here we explore how resource constraints interplay with memory storage function to shape synaptic connectivity of attractor networks. We propose that given a set of memories, in the form of population activity patterns, the neural circuit choses a synaptic connectivity configuration that minimizes a resource usage cost. We argue that the total synaptic weight (l1-norm) in the network measures the resource cost because synaptic weight is correlated with synaptic volume, which is a limited resource, and is proportional to neurotransmitter release and post-synaptic current, both of which cost energy. Using numerical simulations and replica theory, we characterize optimal connectivity profiles in resource-efficient attractor networks. Our theory explains several experimental observations on cortical connectivity profiles, 1) connectivity is sparse, because synapses are costly, 2) bidirectional connections are overrepresented and 3) are stronger, because attractor states need strong recurrence.

The effects of repeat testing, malingering, and traumatic brain injury on visuospatial memory span

Directory of Open Access Journals (Sweden)

David L Woods

2016-01-01

Full Text Available Spatial span tests such as the Corsi Block Test (CBT and the spatial span test of the Wechsler Memory Scale are widely used to assess deficits in spatial working memory. We conducted three experiments to evaluate the test-retest reliability and clinical sensitivity of a new computerized spatial span test (C-SST that incorporates psychophysical methods to improve the precision of spatial span measurement. In Experiment 1, we analyzed C-SST test-retest reliability in 49 participants who underwent three test sessions at weekly intervals. Intraclass correlation coefficients (ICC were higher for a psychophysically derived mean span (MnS metric (0.83 than for the maximal span and total correct metrics used in traditional spatial-span tests. Response times (ReTs also showed high ICCs (0.93 that correlated negatively with MnS scores and correlated positively with response-time latencies from other tests of processing speed. Learning effects were insignificant. Experiment 2 examined the performance of Experiment 1 participants when instructed to feign symptoms of traumatic brain injury: 57% showed abnormal MnS z-scores. A MnS z-score cutoff of 3.0 correctly classified 36% of simulated malingerers and 91% of the subgroup of 11 control participants with abnormal spans. Malingerers also made more substitution errors than control participants with abnormal spans (sensitivity = 43%, specificity = 91%. In addition, malingerers showed no evidence of ReT slowing, in contrast to significant abnormalities seen on other malingered tests of processing speed. As a result, differences between ReT z-scores and z-scores on other processing speed tests showed very high sensitivity and specificity in distinguishing malingering and control participants with either normal or abnormal spans. Experiment 3 examined C-SST performance in a group of patients with predominantly mild traumatic brain injury (TBI: neither MnS nor ReT z-scores showed significant group

Spanning Tree Based Attribute Clustering

DEFF Research Database (Denmark)

Zeng, Yifeng; Jorge, Cordero Hernandez

2009-01-01

Attribute clustering has been previously employed to detect statistical dependence between subsets of variables. We propose a novel attribute clustering algorithm motivated by research of complex networks, called the Star Discovery algorithm. The algorithm partitions and indirectly discards...... inconsistent edges from a maximum spanning tree by starting appropriate initial modes, therefore generating stable clusters. It discovers sound clusters through simple graph operations and achieves significant computational savings. We compare the Star Discovery algorithm against earlier attribute clustering...

Paternal smoking habits affect the reproductive life span of daughters.

Science.gov (United States)

Fukuda, Misao; Fukuda, Kiyomi; Shimizu, Takashi; Nobunaga, Miho; Andersen, Elisabeth Wreford; Byskov, Anne Grete; Andersen, Claus Yding

2011-06-30

The present study assessed whether the smoking habits of fathers around the time of conception affected the period in which daughters experienced menstrual cycles (i.e., the reproductive life span). The study revealed that the smoking habits of the farther shortened the daughters' reproductive life span compared with daughters whose fathers did not smoke. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Behavior of wet precast beam column connections under progressive collapse scenario: an experimental study

Science.gov (United States)

Nimse, Rohit B.; Joshi, Digesh D.; Patel, Paresh V.

2014-12-01

Progressive collapse denotes a failure of a major portion of a structure that has been initiated by failure of a relatively small part of the structure such as failure of any vertical load carrying element (typically columns). Failure of large part of any structure will results into substantial loss of human lives and natural resources. Therefore, it is important to prevent progressive collapse which is also known as disproportionate collapse. Nowadays, there is an increasing trend toward construction of buildings using precast concrete. In precast concrete construction, all the components of structures are produced in controlled environment and they are being transported to the site. At site such individual components are connected appropriately. Connections are the most critical elements of any precast structure, because in past major collapse of precast structure took place because of connection failure. In this study, behavior of three different 1/3rd scaled wet precast beam column connections under progressive collapse scenario are studied and its performance is compared with monolithic connection. Precast connections are constructed by adopting different connection detailing at the junction by considering reinforced concrete corbel for two specimens and steel billet for one specimen. Performance of specimen is evaluated on the basis of ultimate load carrying capacity, maximum deflection and deflection measured along the span of the beam. From the results, it is observed that load carrying capacity and ductility of precast connections considered in this study are more than that of monolithic connections.

Enhancing reading performance through action video games: the role of visual attention span.

Science.gov (United States)

Antzaka, A; Lallier, M; Meyer, S; Diard, J; Carreiras, M; Valdois, S

2017-11-06

Recent studies reported that Action Video Game-AVG training improves not only certain attentional components, but also reading fluency in children with dyslexia. We aimed to investigate the shared attentional components of AVG playing and reading, by studying whether the Visual Attention (VA) span, a component of visual attention that has previously been linked to both reading development and dyslexia, is improved in frequent players of AVGs. Thirty-six French fluent adult readers, matched on chronological age and text reading proficiency, composed two groups: frequent AVG players and non-players. Participants performed behavioural tasks measuring the VA span, and a challenging reading task (reading of briefly presented pseudo-words). AVG players performed better on both tasks and performance on these tasks was correlated. These results further support the transfer of the attentional benefits of playing AVGs to reading, and indicate that the VA span could be a core component mediating this transfer. The correlation between VA span and pseudo-word reading also supports the involvement of VA span even in adult reading. Future studies could combine VA span training with defining features of AVGs, in order to build a new generation of remediation software.

Digit Span as a measure of everyday attention: a study of ecological validity.

Science.gov (United States)

Groth-Marnat, Gary; Baker, Sonya

2003-12-01

This study investigated the effectiveness of the WAIS-III Digit Span subtest to predict the everyday attention of 75 participants with heterogeneous neurological conditions who were administered the Digit Span subtest as well as the ecologically valid Test of Everyday Attention. In addition, the more visually oriented Picture Completion subtest along with the verbally loaded National Adult Reading Test were administered. Analysis indicated that, although Digit Span was a weak but statistically significant predictor of attentional ability (accounting for 12.7% of the unique variance). Picture Completion was a somewhat stronger predictor (accounting for 19% of the unique variance). The weak association of Digit Span and the Test of Everyday Attention, along with the finding that Picture Completion was a better predictor of performance on the Test of Everyday Attention, question the clinical utility of using Digit Span as a measure of everyday attention.

Fatigue life assessment of free spanning pipelines containing corrosion defects

Energy Technology Data Exchange (ETDEWEB)

Lopes, Rita de Kassia D.; Campello, Georga C.; Matt, Cyntia G. da Costa; Benjamin, Adilson C.; Franciss, Ricardo [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

2009-12-19

The free spanning pipelines assessment is a highlighted issue to be considered during the project and maintenance of the submarine pipelines. It is required to evaluate the fatigue life and the maximum stress due to VIV (Vortex Induced Vibration) as well as wave forces when applicable in case of shallow water. The code DNV-RP-F105 (2006) presents a methodology to calculate the fatigue life for free spanning pipelines. Such methodology however considers the pipe with no kind of defects. Nevertheless, sometimes corrosion defects are detected in periodic inspections and therefore their effects need to be taken into account in the fatigue life evaluation. The purpose of this paper thus is to present a procedure to assess the influence of the corrosion defects in the fatigue life of free spanning pipelines. Some FE analyses were performed to determine the stress concentrate factor (SCF) of the corrosion defects, which were used as input in the methodology presented in the code DNV-RP-F105 (2006). Curves of damage and so lifetime have been generated as function of the span length and water depth. As a practical application, this methodology was applied to a sub sea pipeline with several corrosion defects, localized in shallow water offshore Brazil. (author)

Skilled deaf readers have an enhanced perceptual span in reading.

Science.gov (United States)

Bélanger, Nathalie N; Slattery, Timothy J; Mayberry, Rachel I; Rayner, Keith

2012-07-01

Recent evidence suggests that, compared with hearing people, deaf people have enhanced visual attention to simple stimuli viewed in the parafovea and periphery. Although a large part of reading involves processing the fixated words in foveal vision, readers also utilize information in parafoveal vision to preprocess upcoming words and decide where to look next. In the study reported here, we investigated whether auditory deprivation affects low-level visual processing during reading by comparing the perceptual span of deaf signers who were skilled and less-skilled readers with the perceptual span of skilled hearing readers. Compared with hearing readers, the two groups of deaf readers had a larger perceptual span than would be expected given their reading ability. These results provide the first evidence that deaf readers' enhanced attentional allocation to the parafovea is used during complex cognitive tasks, such as reading.

Minimum spanning trees and random resistor networks in d dimensions.

Science.gov (United States)

Read, N

2005-09-01

We consider minimum-cost spanning trees, both in lattice and Euclidean models, in d dimensions. For the cost of the optimum tree in a box of size L , we show that there is a correction of order L(theta) , where theta or =1 . The arguments all rely on the close relation of Kruskal's greedy algorithm for the minimum spanning tree, percolation, and (for some arguments) random resistor networks. The scaling of the entropy and free energy at small nonzero T , and hence of the number of near-optimal solutions, is also discussed. We suggest that the Steiner tree problem is in the same universality class as the minimum spanning tree in all dimensions, as is the traveling salesman problem in two dimensions. Hence all will have the same value of theta=-3/4 in two dimensions.

Whole Genome Analysis of Injectional Anthrax Identifies Two Disease Clusters Spanning More Than 13 Years

Directory of Open Access Journals (Sweden)

Paul Keim

2015-11-01

Lay Person Interpretation: Injectional anthrax has been plaguing heroin drug users across Europe for more than 10 years. In order to better understand this outbreak, we assessed genomic relationships of all available injectional anthrax strains from four countries spanning a >12 year period. Very few differences were identified using genome-based analysis, but these differentiated the isolates into two distinct clusters. This strongly supports a hypothesis of at least two separate anthrax spore contamination events perhaps during the drug production processes. Identification of two events would not have been possible from standard epidemiological analysis. These comprehensive data will be invaluable for classifying future injectional anthrax isolates and for future geographic attribution.

Sex differences in life span: Females homozygous for the X chromosome do not suffer the shorter life span predicted by the unguarded X hypothesis.

Science.gov (United States)

Brengdahl, Martin; Kimber, Christopher M; Maguire-Baxter, Jack; Friberg, Urban

2018-03-01

Life span differs between the sexes in many species. Three hypotheses to explain this interesting pattern have been proposed, involving different drivers: sexual selection, asymmetrical inheritance of cytoplasmic genomes, and hemizygosity of the X(Z) chromosome (the unguarded X hypothesis). Of these, the unguarded X has received the least experimental attention. This hypothesis suggests that the heterogametic sex suffers a shortened life span because recessive deleterious alleles on its single X(Z) chromosome are expressed unconditionally. In Drosophila melanogaster, the X chromosome is unusually large (∼20% of the genome), providing a powerful model for evaluating theories involving the X. Here, we test the unguarded X hypothesis by forcing D. melanogaster females from a laboratory population to express recessive X-linked alleles to the same degree as males, using females exclusively made homozygous for the X chromosome. We find no evidence for reduced life span or egg-to-adult viability due to X homozygozity. In contrast, males and females homozygous for an autosome both suffer similar, significant reductions in those traits. The logic of the unguarded X hypothesis is indisputable, but our results suggest that the degree to which recessive deleterious X-linked alleles depress performance in the heterogametic sex appears too small to explain general sex differences in life span. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

A Flavorful Factoring of the Strong CP Problem

Energy Technology Data Exchange (ETDEWEB)

Agrawal, Prateek [Harvard U., Phys. Dept.; Howe, Kiel [Fermilab

2017-12-15

Motivated by the intimate connection between the strong CP problem and the flavor structure of the Standard Model, we present a flavor model that revives and extends the classic ${m_u=0}$ solution to the strong CP problem. QCD is embedded into a $SU(3)_1\\times SU(3)_2 \\times SU(3)_3$ gauge group, with each generation of quarks charged under the respective $SU(3)$. The non-zero value of the up-quark Yukawa coupling (along with the strange quark and bottom-quark Yukawas) is generated by contributions from small instantons at a new scale $M \\gg \\Lambda_{QCD}$. The Higgsing of $SU(3)^3\\to SU(3)_c$ allows dimension-5 operators that generate the Standard Model flavor structure and can be completed in a simple renormalizable theory. The smallness of the third generation mixing angles can naturally emerge in this picture, and is connected to the smallness of threshold corrections to $\\bar\\theta$. Remarkably, $\\bar\\theta$ is essentially fixed by the measured quark masses and mixings, and is estimated to be close to the current experimental bound and well within reach of the next generation of neutron and proton EDM experiments.

Suture spanning augmentation of single-row rotator cuff repair: a biomechanical analysis.

Science.gov (United States)

Early, Nicholas A; Elias, John J; Lippitt, Steven B; Filipkowski, Danielle E; Pedowitz, Robert A; Ciccone, William J

2017-02-01

This in vitro study evaluated the biomechanical benefit of adding spanning sutures to single-row rotator cuff repair. Mechanical testing was performed to evaluate 9 pairs of cadaveric shoulders with complete rotator cuff repairs, with a single-row technique used on one side and the suture spanning technique on the other. The spanning technique included sutures from 2 lateral anchors securing tendon near the musculotendinous junction, spanning the same anchor placement from single-row repair. The supraspinatus muscle was loaded to 100 N at 0.25 Hz for 100 cycles, followed by a ramp to failure. Markers and a video tracking system measured anterior and posterior gap formation across the repair at 25-cycle intervals. The force at which the stiffness decreased by 50% and 75% was determined. Data were compared using paired t-tests. One single-row repair failed at row repairs than for the suture spanning technique. The difference was statistically significant at all cycles for the posterior gap formation (P ≤ .02). The trends were not significant for the anterior gap (P ≥ .13). The loads at which the stiffness decreased by 50% and 75% did not differ significantly between the 2 types of repair (P ≥ .10). The suture spanning technique primarily improved posterior gap formation. Decreased posterior gap formation could reduce failure rates for rotator cuff repair. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Flutter suppression and stability analysis for a variable-span wing via morphing technology

Science.gov (United States)

Li, Wencheng; Jin, Dongping

2018-01-01

A morphing wing can enhance aerodynamic characteristics and control authority as an alternative to using ailerons. To use morphing technology for flutter suppression, the dynamical behavior and stability of a variable-span wing subjected to the supersonic aerodynamic loads are investigated numerically in this paper. An axially moving cantilever plate is employed to model the variable-span wing, in which the governing equations of motion are established via the Kane method and piston theory. A morphing strategy based on axially moving rates is proposed to suppress the flutter that occurs beyond the critical span length, and the flutter stability is verified by Floquet theory. Furthermore, the transient stability during the morphing motion is analyzed and the upper bound of the morphing rate is obtained. The simulation results indicate that the proposed morphing law, which is varying periodically with a proper amplitude, could accomplish the flutter suppression. Further, the upper bound of the morphing speed decreases rapidly once the span length is close to its critical span length.

Modelling ecosystem service flows under uncertainty with stochiastic SPAN

Science.gov (United States)

Johnson, Gary W.; Snapp, Robert R.; Villa, Ferdinando; Bagstad, Kenneth J.

2012-01-01

Ecosystem service models are increasingly in demand for decision making. However, the data required to run these models are often patchy, missing, outdated, or untrustworthy. Further, communication of data and model uncertainty to decision makers is often either absent or unintuitive. In this work, we introduce a systematic approach to addressing both the data gap and the difficulty in communicating uncertainty through a stochastic adaptation of the Service Path Attribution Networks (SPAN) framework. The SPAN formalism assesses ecosystem services through a set of up to 16 maps, which characterize the services in a study area in terms of flow pathways between ecosystems and human beneficiaries. Although the SPAN algorithms were originally defined deterministically, we present them here in a stochastic framework which combines probabilistic input data with a stochastic transport model in order to generate probabilistic spatial outputs. This enables a novel feature among ecosystem service models: the ability to spatially visualize uncertainty in the model results. The stochastic SPAN model can analyze areas where data limitations are prohibitive for deterministic models. Greater uncertainty in the model inputs (including missing data) should lead to greater uncertainty expressed in the model’s output distributions. By using Bayesian belief networks to fill data gaps and expert-provided trust assignments to augment untrustworthy or outdated information, we can account for uncertainty in input data, producing a model that is still able to run and provide information where strictly deterministic models could not. Taken together, these attributes enable more robust and intuitive modelling of ecosystem services under uncertainty.

System-spanning dynamically jammed region in response to impact of cornstarch and water suspensions

Science.gov (United States)

Allen, Benjamin; Sokol, Benjamin; Mukhopadhyay, Shomeek; Maharjan, Rijan; Brown, Eric

2018-05-01

We experimentally characterize the structure of concentrated suspensions of cornstarch and water in response to impact. Using surface imaging and particle tracking at the boundary opposite the impactor, we observed that a visible structure and particle flow at the boundary occur with a delay after impact. We show the delay time is about the same time as the strong stress response, confirming that the strong stress response results from deformation of the dynamically jammed structure once it spans between the impactor and a solid boundary. A characterization of this strong stress response is reported in a companion paper [Maharjan, Mukhopadhyay, Allen, Storz, and Brown, Phys. Rev. E 97, 052602 (2018), 10.1103/PhysRevE.97.052602]. We observed particle flow in the outer part of the dynamically jammed region at the bottom boundary, with a net transverse displacement of up to about 5% of the impactor displacement, indicating shear at the boundary. Direct imaging of the surface of the outer part of the dynamically jammed region reveals a change in surface structure that appears the same as the result of dilation in other cornstarch suspensions. Imaging also reveals cracks, like a brittle solid. These observations suggest the dynamically jammed structure can temporarily support stress according to an effective modulus, like a soil or dense granular material, along a network of frictional contacts between the impactor and solid boundary.

The DES Bright Arcs Survey: Hundreds of Candidate Strongly Lensed Galaxy Systems from the Dark Energy Survey Science Verification and Year 1 Observations

Energy Technology Data Exchange (ETDEWEB)

Diehl, H. T.; Buckley-Geer, E. J.; Lindgren, K. A.; Nord, B.; Gaitsch, H.; Gaitsch, S.; Lin, H.; Allam, S.; Odden, C.; Pellico, A.; Tucker, D. L.; Kuropatkin, N.; Soares-Santos, M. [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 (United States); Collett, T. E. [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom); Furlanetto, C.; Nightingale, J. [University of Nottingham, School of Physics and Astronomy, Nottingham NG7 2RD (United Kingdom); Gill, M. S. S. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); More, A. [Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Costa, L. N. da; Neto, A. Fausti, E-mail: diehl@fnal.gov [Laboratório Interinstitucional de e-Astronomia—LIneA, Rua Gal. José Cristino 77, Rio de Janeiro, RJ—20921-400 (Brazil); Collaboration: DES Collaboration; and others

2017-09-01

We report the results of searches for strong gravitational lens systems in the Dark Energy Survey (DES) Science Verification and Year 1 observations. The Science Verification data span approximately 250 sq. deg. with a median i -band limiting magnitude for extended objects (10 σ ) of 23.0. The Year 1 data span approximately 2000 sq. deg. and have an i -band limiting magnitude for extended objects (10 σ ) of 22.9. As these data sets are both wide and deep, they are particularly useful for identifying strong gravitational lens candidates. Potential strong gravitational lens candidate systems were initially identified based on a color and magnitude selection in the DES object catalogs or because the system is at the location of a previously identified galaxy cluster. Cutout images of potential candidates were then visually scanned using an object viewer and numerically ranked according to whether or not we judged them to be likely strong gravitational lens systems. Having scanned nearly 400,000 cutouts, we present 374 candidate strong lens systems, of which 348 are identified for the first time. We provide the R.A. and decl., the magnitudes and photometric properties of the lens and source objects, and the distance (radius) of the source(s) from the lens center for each system.

Direct Modulation Of Aberrant Brain Network Connectivity Through Real-Time NeuroFeedback

OpenAIRE

White, Emily; Popal, Haroon; Roopchansingh, Vinai; Gonzalez-Castillo, Javier; Kimmich, Sara; Ramot, Michal; Martin Ph.D., Alex; Gotts, Stephen

2017-01-01

eLife digest Even when we are at rest, our brains are always active. For example, areas of the brain involved in vision remain active in complete darkness. Different brain regions that connect together to perform a given task often show coordinated activity at rest. Past studies have shown that these resting connections are different in people with conditions such as autism. Some brain regions are more weakly connected while others are more strongly connected in people with autism spectrum di...

Natural ventilation of large multi-span greenhouses

NARCIS (Netherlands)

Jong, de T.

1990-01-01

In this thesis the ventilation of large multi-span greenhouses caused by wind and temperature effects is studied. Quantification of the ventilation is important to improve the control of the greenhouse climate.

Knowledge of the flow characteristics of the one-side-mounted windows of

Leaf life span plasticity in tropical seedlings grown under contrasting light regimes.

Science.gov (United States)

Vincent, Gregoire

2006-02-01

The phenotypic plasticity of leaf life span in response to low resource conditions has a potentially large impact on the plant carbon budget, notably in evergreen species not subject to seasonal leaf shedding, but has rarely been well documented. This study evaluates the plasticity of leaf longevity, in terms of its quantitative importance to the plant carbon balance under limiting light. Seedlings of four tropical tree species with contrasting light requirements (Alstonia scholaris, Hevea brasiliensis, Durio zibethinus and Lansium domesticum) were grown under three light regimes (full sunlight, 45 % sunlight and 12 % sunlight). Their leaf dynamics were monitored over 18 months. All species showed a considerable level of plasticity with regard to leaf life span: over the range of light levels explored, the ratio of the range to the mean value of life span varied from 29 %, for the least plastic species, to 84 %, for the most. The common trend was for leaf life span to increase with decreasing light intensity. The plasticity apparent in leaf life span was similar in magnitude to the plasticity observed in specific leaf area and photosynthetic rate, implying that it has a significant impact on carbon gain efficiency when plants acclimate to different light regimes. In all species, median survival time was negatively correlated with leaf photosynthetic capacity (or its proxy, the nitrogen content per unit area) and leaf emergence rate. Longer leaf life spans under low light are likely to be a consequence of slower ageing as a result of a slower photosynthetic metabolism.

The DES Bright Arcs Survey: Hundreds of Candidate Strongly Lensed Galaxy Systems from the Dark Energy Survey Science Verification and Year 1 Observations

Energy Technology Data Exchange (ETDEWEB)

Diehl, H. T.; Buckley-Geer, E. J.; Lindgren, K. A.; Nord, B.; Gaitsch, H.; Gaitsch, S.; Lin, H.; Allam, S.; Collett, T. E.; Furlanetto, C.; Gill, M. S. S.; More, A.; Nightingale, J.; Odden, C.; Pellico, A.; Tucker, D. L.; Costa, L. N. da; Neto, A. Fausti; Kuropatkin, N.; Soares-Santos, M.; Welch, B.; Zhang, Y.; Frieman, J. A.; Abdalla, F. B.; Annis, J.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Burke, D. L.; Rosell, A. Carnero; Kind, M. Carrasco; Carretero, J.; Cunha, C. E.; D’Andrea, C. B.; Desai, S.; Dietrich, J. P.; Drlica-Wagner, A.; Evrard, A. E.; Finley, D. A.; Flaugher, B.; García-Bellido, J.; Gerdes, D. W.; Goldstein, D. A.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; James, D. J.; Kuehn, K.; Kuhlmann, S.; Lahav, O.; Li, T. S.; Lima, M.; Maia, M. A. G.; Marshall, J. L.; Menanteau, F.; Miquel, R.; Nichol, R. C.; Nugent, P.; Ogando, R. L. C.; Plazas, A. A.; Reil, K.; Romer, A. K.; Sako, M.; Sanchez, E.; Santiago, B.; Scarpine, V.; Schindler, R.; Schubnell, M.; Sevilla-Noarbe, I.; Sheldon, E.; Smith, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Walker, A. R.

2017-09-01

We report the results of our searches for strong gravitational lens systems in the Dark Energy Survey (DES) Science Verication and Year 1 observations. The Science Verication data spans approximately 250 sq. deg. with median i

Time and resource limits on working memory: cross-age consistency in counting span performance.

Science.gov (United States)

Ransdell, Sarah; Hecht, Steven

2003-12-01

This longitudinal study separated resource demand effects from those of retention interval in a counting span task among 100 children tested in grade 2 and again in grades 3 and 4. A last card large counting span condition had an equivalent memory load to a last card small, but the last card large required holding the count over a longer retention interval. In all three waves of assessment, the last card large condition was found to be less accurate than the last card small. A model predicting reading comprehension showed that age was a significant predictor when entered first accounting for 26% of the variance, but counting span accounted for a further 22% of the variance. Span at Wave 1 accounted for significant unique variance at Wave 2 and at Wave 3. Results were similar for math calculation with age accounting for 31% of the variance and counting span accounting for a further 34% of the variance. Span at Wave 1 explained unique variance in math at Wave 2 and at Wave 3.

Relationships between Categorical Perception of Phonemes, Phoneme Awareness, and Visual Attention Span in Developmental Dyslexia.

Directory of Open Access Journals (Sweden)

Rachel Zoubrinetzky

Full Text Available We tested the hypothesis that the categorical perception deficit of speech sounds in developmental dyslexia is related to phoneme awareness skills, whereas a visual attention (VA span deficit constitutes an independent deficit. Phoneme awareness tasks, VA span tasks and categorical perception tasks of phoneme identification and discrimination using a d/t voicing continuum were administered to 63 dyslexic children and 63 control children matched on chronological age. Results showed significant differences in categorical perception between the dyslexic and control children. Significant correlations were found between categorical perception skills, phoneme awareness and reading. Although VA span correlated with reading, no significant correlations were found between either categorical perception or phoneme awareness and VA span. Mediation analyses performed on the whole dyslexic sample suggested that the effect of categorical perception on reading might be mediated by phoneme awareness. This relationship was independent of the participants' VA span abilities. Two groups of dyslexic children with a single phoneme awareness or a single VA span deficit were then identified. The phonologically impaired group showed lower categorical perception skills than the control group but categorical perception was similar in the VA span impaired dyslexic and control children. The overall findings suggest that the link between categorical perception, phoneme awareness and reading is independent from VA span skills. These findings provide new insights on the heterogeneity of developmental dyslexia. They suggest that phonological processes and VA span independently affect reading acquisition.

Relationships between Categorical Perception of Phonemes, Phoneme Awareness, and Visual Attention Span in Developmental Dyslexia.

Science.gov (United States)

Zoubrinetzky, Rachel; Collet, Gregory; Serniclaes, Willy; Nguyen-Morel, Marie-Ange; Valdois, Sylviane

2016-01-01

We tested the hypothesis that the categorical perception deficit of speech sounds in developmental dyslexia is related to phoneme awareness skills, whereas a visual attention (VA) span deficit constitutes an independent deficit. Phoneme awareness tasks, VA span tasks and categorical perception tasks of phoneme identification and discrimination using a d/t voicing continuum were administered to 63 dyslexic children and 63 control children matched on chronological age. Results showed significant differences in categorical perception between the dyslexic and control children. Significant correlations were found between categorical perception skills, phoneme awareness and reading. Although VA span correlated with reading, no significant correlations were found between either categorical perception or phoneme awareness and VA span. Mediation analyses performed on the whole dyslexic sample suggested that the effect of categorical perception on reading might be mediated by phoneme awareness. This relationship was independent of the participants' VA span abilities. Two groups of dyslexic children with a single phoneme awareness or a single VA span deficit were then identified. The phonologically impaired group showed lower categorical perception skills than the control group but categorical perception was similar in the VA span impaired dyslexic and control children. The overall findings suggest that the link between categorical perception, phoneme awareness and reading is independent from VA span skills. These findings provide new insights on the heterogeneity of developmental dyslexia. They suggest that phonological processes and VA span independently affect reading acquisition.

Relationships between Categorical Perception of Phonemes, Phoneme Awareness, and Visual Attention Span in Developmental Dyslexia

Science.gov (United States)

Zoubrinetzky, Rachel; Collet, Gregory; Serniclaes, Willy; Nguyen-Morel, Marie-Ange; Valdois, Sylviane

2016-01-01

We tested the hypothesis that the categorical perception deficit of speech sounds in developmental dyslexia is related to phoneme awareness skills, whereas a visual attention (VA) span deficit constitutes an independent deficit. Phoneme awareness tasks, VA span tasks and categorical perception tasks of phoneme identification and discrimination using a d/t voicing continuum were administered to 63 dyslexic children and 63 control children matched on chronological age. Results showed significant differences in categorical perception between the dyslexic and control children. Significant correlations were found between categorical perception skills, phoneme awareness and reading. Although VA span correlated with reading, no significant correlations were found between either categorical perception or phoneme awareness and VA span. Mediation analyses performed on the whole dyslexic sample suggested that the effect of categorical perception on reading might be mediated by phoneme awareness. This relationship was independent of the participants’ VA span abilities. Two groups of dyslexic children with a single phoneme awareness or a single VA span deficit were then identified. The phonologically impaired group showed lower categorical perception skills than the control group but categorical perception was similar in the VA span impaired dyslexic and control children. The overall findings suggest that the link between categorical perception, phoneme awareness and reading is independent from VA span skills. These findings provide new insights on the heterogeneity of developmental dyslexia. They suggest that phonological processes and VA span independently affect reading acquisition. PMID:26950210

On Pure and (approximate) Strong Equilibria of Facility Location Games

DEFF Research Database (Denmark)

Hansen, Thomas Dueholm; Telelis, Orestis A.

2008-01-01

We study social cost losses in Facility Location games, where n selfish agents install facilities over a network and connect to them, so as to forward their local demand (expressed by a non-negative weight per agent). Agents using the same facility share fairly its installation cost, but every...... agent pays individually a (weighted) connection cost to the chosen location. We study the Price of Stability (PoS) of pure Nash equilibria and the Price of Anarchy of strong equilibria (SPoA), that generalize pure equilibria by being resilient to coalitional deviations. For unweighted agents on metric...

Comparison between BIDE, PrefixSpan, and TRuleGrowth for Mining of Indonesian Text

Science.gov (United States)

Sa'adillah Maylawati, Dian; Irfan, Mohamad; Budiawan Zulfikar, Wildan

2017-01-01

Mining proscess for Indonesian language still be an interesting research. Multiple of words representation was claimed can keep the meaning of text better than bag of words. In this paper, we compare several sequential pattern algortihm, among others BIDE (BIDirectional Extention), PrefixSpan, and TRuleGrowth. All of those algorithm produce frequent word sequence to keep the meaning of text. However, the experiment result, with 14.006 of Indonesian tweet from Twitter, shows that BIDE can produce more efficient frequent word sequence than PrefixSpan and TRuleGrowth without missing the meaning of text. Then, the average of time process of PrefixSpan is faster than BIDE and TRuleGrowth. In the other hand, PrefixSpan and TRuleGrowth is more efficient in using memory than BIDE.

Parents' and Teachers' Perceptions of Abnormal Attention Span of Elementary School-Age Children.

Science.gov (United States)

Segal-Triwitz, Yael; Kirchen, Louisa M; Shani Sherman, Tal; Levav, Miriam; Schonherz-Pine, Yael; Kushnir, Jonathan; Ariel, Raya; Gothelf, Doron

2016-01-01

To determine teacher and parental perception of minimal expected sustained attention span during various daily tasks among elementary school children. 54 parents and 47 teachers completed the attention span questionnaire (AtSQ) that was developed for this study. The AtSQ consists of 15 academic and leisure tasks that require a child's sustained attention. The study focused on third and fourth graders in Israel. There was a high degree of variability among teachers and parents in their responses to the AtSQ. The expected attention span of children as judged by parents was higher and more varied compared to teachers, and higher for girls than for boys. Our results indicate poor agreement in cutoff values for sustained attention span between teachers and parents and within each group.

Strong versions of Bell's theorem

International Nuclear Information System (INIS)

Stapp, H.P.

1994-01-01

Technical aspects of a recently constructed strong version of Bell's theorem are discussed. The theorem assumes neither hidden variables nor factorization, and neither determinism nor counterfactual definiteness. It deals directly with logical connections. Hence its relationship with modal logic needs to be described. It is shown that the proof can be embedded in an orthodox modal logic, and hence its compatibility with modal logic assured, but that this embedding weakens the theorem by introducing as added assumptions the conventionalities of the particular modal logic that is adopted. This weakening is avoided in the recent proof by using directly the set-theoretic conditions entailed by the locality assumption

Two Distinct Scene-Processing Networks Connecting Vision and Memory.

Science.gov (United States)

Baldassano, Christopher; Esteva, Andre; Fei-Fei, Li; Beck, Diane M

2016-01-01

A number of regions in the human brain are known to be involved in processing natural scenes, but the field has lacked a unifying framework for understanding how these different regions are organized and interact. We provide evidence from functional connectivity and meta-analyses for a new organizational principle, in which scene processing relies upon two distinct networks that split the classically defined parahippocampal place area (PPA). The first network of strongly connected regions consists of the occipital place area/transverse occipital sulcus and posterior PPA, which contain retinotopic maps and are not strongly coupled to the hippocampus at rest. The second network consists of the caudal inferior parietal lobule, retrosplenial complex, and anterior PPA, which connect to the hippocampus (especially anterior hippocampus), and are implicated in both visual and nonvisual tasks, including episodic memory and navigation. We propose that these two distinct networks capture the primary functional division among scene-processing regions, between those that process visual features from the current view of a scene and those that connect information from a current scene view with a much broader temporal and spatial context. This new framework for understanding the neural substrates of scene-processing bridges results from many lines of research, and makes specific functional predictions.

Aeroelastic stability of full-span tiltrotor aircraft model in forward flight

Directory of Open Access Journals (Sweden)

Zhiquan LI

2017-12-01

Full Text Available The existing full-span models of the tiltrotor aircraft adopted the rigid blade model without considering the coupling relationship among the elastic blade, wing and fuselage. To overcome the limitations of the existing full-span models and improve the precision of aeroelastic analysis of tiltrotor aircraft in forward flight, the aeroelastic stability analysis model of full-span tiltrotor aircraft in forward flight has been presented in this paper by considering the coupling among elastic blade, wing, fuselage and various components. The analytical model is validated by comparing with the calculation results and experimental data in the existing references. The influence of some structural parameters, such as the fuselage degrees of freedom, relative displacement between the hub center and the gravity center, and nacelle length, on the system stability is also investigated. The results show that the fuselage degrees of freedom decrease the critical stability velocity of tiltrotor aircraft, and the variation of the structural parameters has great influence on the system stability, and the instability form of system can change between the anti-symmetric and symmetric wing motions of vertical and chordwise bending. Keywords: Aeroelastic stability, Forward flight, Full-span model, Modal analysis, Tiltrotor aircraft

Anticipating changes to future connectivity within a network of marine protected areas.

Science.gov (United States)

Coleman, Melinda A; Cetina-Heredia, Paulina; Roughan, Moninya; Feng, Ming; van Sebille, Erik; Kelaher, Brendan P

2017-09-01

Continental boundary currents are projected to be altered under future scenarios of climate change. As these currents often influence dispersal and connectivity among populations of many marine organisms, changes to boundary currents may have dramatic implications for population persistence. Networks of marine protected areas (MPAs) often aim to maintain connectivity, but anticipation of the scale and extent of climatic impacts on connectivity are required to achieve this critical conservation goal in a future of climate change. For two key marine species (kelp and sea urchins), we use oceanographic modelling to predict how continental boundary currents are likely to change connectivity among a network of MPAs spanning over 1000 km of coastline off the coast of eastern Australia. Overall change in predicted connectivity among pairs of MPAs within the network did not change significantly over and above temporal variation within climatic scenarios, highlighting the need for future studies to incorporate temporal variation in dispersal to robustly anticipate likely change. However, the intricacies of connectivity between different pairs of MPAs were noteworthy. For kelp, poleward connectivity among pairs of MPAs tended to increase in the future, whereas equatorward connectivity tended to decrease. In contrast, for sea urchins, connectivity among pairs of MPAs generally decreased in both directions. Self-seeding within higher-latitude MPAs tended to increase, and the role of low-latitude MPAs as a sink for urchins changed significantly in contrasting ways. These projected changes have the potential to alter important genetic parameters with implications for adaptation and ecosystem vulnerability to climate change. Considering such changes, in the context of managing and designing MPA networks, may ensure that conservation goals are achieved into the future. © 2017 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Functional and effective whole brain connectivity using magnetoencephalography to identify monozygotic twin pairs

NARCIS (Netherlands)

Demuru, M.; Gouw, A.; Hillebrand, A.; Stam, C J; van Dijk, B W; Scheltens, P.; Tijms, B.M.; Konijnenberg, E.; ten Kate-Booij, M.J.; den Braber, A; Smit, D J A; Boomsma, D I; Visser, P J

2017-01-01

Resting-state functional connectivity patterns are highly stable over time within subjects. This suggests that such 'functional fingerprints' may have strong genetic component. We investigated whether the functional (FC) or effective (EC) connectivity patterns of one monozygotic twin could be used

[The evolution of plant life span: facts and hypotheses].

Science.gov (United States)

2006-01-01

There are two different views on the evolution of life forms in Cormophyta: from woody plants to herbaceous ones or in opposite direction - from herbs to trees. In accordance with these views it is supposed that life span in plants changed in the course of evolution from many years (perennials) to few years (annuals, biennials), or went in reverse - from few years to many years. The author discusses the problems of senescence and longevity in Cormophyta in the context of various hypotheses of ageing (programmed death theory, mutation accumulation, antagonistic pleiotropy, disposable soma, genes of ageing, genes of longevity). Special attention is given to bio-morphological aspects of longevity and cases of non-ageing plants ("negative senescence", "potential immortality"). It is proposed to distinguish seven models of simple ontogenesis in Cormophyta that can exemplify the diversity of mechanisms of ageing and longevity. The evolution of life span in plants is considered as an indirect result of natural selection of other characteristics of organisms or as a consequence of fixation of modifications (episelectional evolution). It seems that short life span could emerge several times during evolution of one group of plants, thus favoring its adaptive radiation.

Low doze γ-irradiation influence on drosophila life span in different genetics background

International Nuclear Information System (INIS)

Moskalev, A.

2007-01-01

Complete text of publication follows. The main goal of this work was to study in Drosophila melanogaster the contribution of DNA damage sensing and repair, apoptosis and heat shock defence into life span and physical activity alteration after gamma-irradiation at low doze rate. In our experiments, the strains were exposed to chronic gamma-irradiation from a 226Ra source (50 R/h) at doze rate 0.17 cGy/h at pre-imago development stages only. The absorbed radiation dose per generation (from embryo to imago, 12 days) was 60 cGy. Life span estimation was prepared in adult males and females separately. We compared the life span of apoptotic (p53, DIAP-1, dApaf-1, Dcp-1, reaper, grim and hid), heat shock defence (HSP70, HSP23, HSF), DNA damage sensing (ATR) and repair (XPF, XPC, PCNA, DSB repair helicase homologs) mutants after chronic irradiation with the control. On the basis of our investigation we have concluded: 1) Low doze irradiation alter the life span depending on genetic background (mutant alleles, heterozygosity level and sex); 2) Age dynamics of physical activity positively correlates with the life span; 3) Longevity potential forms at early development stages; 4) DNA damage sensing, DNA repair, heat shock defence and apoptosis as aging preventing mechanisms play crucial role in radiation-induced life span hormesis.

Currency crises and the evolution of foreign exchange market: Evidence from minimum spanning tree

Science.gov (United States)

Jang, Wooseok; Lee, Junghoon; Chang, Woojin

2011-02-01

We examined the time series properties of the foreign exchange market for 1990-2008 in relation to the history of the currency crises using the minimum spanning tree (MST) approach and made several meaningful observations about the MST of currencies. First, around currency crises, the mean correlation coefficient between currencies decreased whereas the normalized tree length increased. The mean correlation coefficient dropped dramatically passing through the Asian crisis and remained at the lowered level after that. Second, the Euro and the US dollar showed a strong negative correlation after 1997, implying that the prices of the two currencies moved in opposite directions. Third, we observed that Asian countries and Latin American countries moved away from the cluster center (USA) passing through the Asian crisis and Argentine crisis, respectively.

The effect of span length and girder type on bridge costs

Directory of Open Access Journals (Sweden)

Batikha Mustafa

2017-01-01

Full Text Available Bridges have an important role in impacting the civilization, growth and economy of cities from ancient time until these days due to their function in reducing transportation cost and time. Therefore, development of bridges has been a knowledge domain in civil engineering studies in terms of their types and construction materials to confirm a reliable, safe, economic design and construction. Girder-bridge of concrete deck and I-beam girder has been used widely for short and medium span bridges because of ease and low-cost of fabrication. However, many theoretical and practical investigations are still undertaken regarding the type of beam girder; i.e steel composite or prestressed concrete. This paper evaluates the effect of bridge span and the type of girder on the capital cost and life cycle costs of bridges. Three types of girders were investigated in this research: steel composite, pre-tensioned pre-stressed concrete and post-tensioned pre-stressed concrete. The structural design was analyzed for 5 span lengths: 20, 25, 30, 35 and 40m. Then, the capital construction cost was accounted for 15 bridges according to each span and construction materials. Moreover, the maintenance required for 50 years of bridge life was evaluated and built up as whole life costs for each bridge. As a result of this study, the influence of both span length and type of girder on initial construction cost and maintenance whole life costs were assessed to support the decision makers and designers in the selection process for the optimum solution of girder bridges.

Diferença entre span verbal e visual nos gêneros: estudo piloto

Directory of Open Access Journals (Sweden)

Mariana Cristina Pedrassa Sagrilo

2013-06-01

Full Text Available OBJETIVO: avaliar a memória de trabalho analisando a capacidade de retenção de estímulos auditivos (span verbal e visuais (span visual e estabelecer a relação com o gênero (masculino e feminino. MÉTODO: participaram deste estudo 20 crianças entre seis anos e cinco meses e sete anos, sendo 10 sujeitos do sexo masculino e 10 sujeitos do sexo feminino. Todos os sujeitos foram submetidos às provas de avaliação do span verbal e visual em ordem direta e inversa. RESULTADOS: apenas na prova de palavras dissílabas com fonologia semelhante e semântica diferente do span verbal, houve variância significante entre os gêneros. As crianças do sexo feminino apresentaram melhor desempenho em relação ao outro gênero, bem como maior capacidade de retenção de palavras dissílabas com fonologia e semântica diferentes. No span visual (ordem direta e inversa as crianças do sexo masculino obtiveram melhor desempenho, apesar de não ter diferenças significantes. Em relação à idade não houve diferença de retenção de estímulos. CONCLUSÃO: as crianças do sexo feminino, neste estudo, apresentaram tendência à melhor desempenho do span verbal e as crianças do sexo masculino tendência a melhor desempenho no span visual. No entanto, o estudo é limitado devido ao reduzido número de participantes na amostra.

Qualitative Exploration of Acculturation and Life-Span Issues of Elderly Asian Americans

Science.gov (United States)

Lee, Jee Hyang; Heo, Nanseol; Lu, Junfei; Portman, Tarrell Awe Agahe

2013-01-01

Awareness of aging issues across diverse populations begins the journey toward counselors becoming culturally competent across client life spans. Understanding the life-span experiences of cultural groups is important for helping professionals. The purpose of this research was to gain insight into the qualitative experiences of Asian American…

An improved algorithm for connectivity analysis of distribution networks

International Nuclear Information System (INIS)

Kansal, M.L.; Devi, Sunita

2007-01-01

In the present paper, an efficient algorithm for connectivity analysis of moderately sized distribution networks has been suggested. Algorithm is based on generation of all possible minimal system cutsets. The algorithm is efficient as it identifies only the necessary and sufficient conditions of system failure conditions in n-out-of-n type of distribution networks. The proposed algorithm is demonstrated with the help of saturated and unsaturated distribution networks. The computational efficiency of the algorithm is justified by comparing the computational efforts with the previously suggested appended spanning tree (AST) algorithm. The proposed technique has the added advantage as it can be utilized for generation of system inequalities which is useful in reliability estimation of capacitated networks

Political Connections and Investment in Rural Vietnam

DEFF Research Database (Denmark)

Markussen, Thomas; Tarp, Finn

This paper uses household panel data from rural Vietnam to explore the effects of having a relative in a position of political or bureaucratic power on farmers’ agricultural investment decisions. Our main result is that households significantly increase their investment in land improvement...... as a result of relatives moving into public office. Connections to office holders appear to be important for investment because they strengthen de facto land property rights and improve access to off-farm employment and to informal loans. The findings underline the importance of informal networks for economic...... behaviour in environments with developing institutions and markets. They also suggest the presence of an untapped potential for economic development: if households without connections could obtain equally strong property rights and access to credit and insurance as the well-connected households, investment...

Experimental investigation of span length for flexural test of fiber reinforced polymer composite laminates

Directory of Open Access Journals (Sweden)

Akhil Mehndiratta

2018-01-01

Full Text Available Testing and evaluation of mechanical properties for FRP (Fiber Reinforced Polymer composite parts play a significant role to qualify it for the end use. Among the mechanical properties, the flexural strength is significant and vital as it may vary with specimen depth, temperature and the test span length. The flexural strength varies for different materials with varying the test span length hence the current work aims to find an optimum span length to test flexural strength for the specimens made of Glass (7781, EC9756 and Carbon (HTA7, G801 prepreg materials. Experiments are conducted as per the ASTM Standard D 790 for flexural test by varying the span lengths to understand the behavior of the flexural strength and flexural modulus. The experimental data were compared with those obtained from the finite element program software Altair Hyper works 14.0. The results indicate that flexural modulus increases with the span length to a point and then it decreases. Thereby, an optimum span length can be obtained for testing flexural strength, which will be useful to the designers and the composite manufacturers to accomplish better standard testing procedures.

A Wide Span Tractor concept developed for efficient and environmental friendly farming

DEFF Research Database (Denmark)

Pedersen, Hans Henrik; Grøn Sørensen, Claus; Oudshoorn, Frank W

2013-01-01

agricultural machines a new Wide Span (WS) tractor concept has been designed and a prototype tractor with a span of 9.6 m (wheel centre to wheel centre) has been built. It is designed to optimise the Controlled Traffic Farming (CTF) system that is already in place on the vegetable farm where it is being tested....... The tractor is designed to carry out all operations during vegetable production including harvest. Using the tractor means that less than 10% of the field area is affected by compaction due to field traffic. The economical and environmental effects of such a wide span CTF growing system will be assessed....

Connective tissue regeneration in skeletal muscle after eccentric contraction-induced injury

DEFF Research Database (Denmark)

Mackey, Abigail Louise; Kjaer, Michael

2017-01-01

Human skeletal muscle has the potential to regenerate completely after injury induced under controlled experimental conditions. The events inside the myofibres as they undergo necrosis, followed closely by satellite cell mediated myogenesis, have been mapped in detail. Much less is known about...... the adaptation throughout this process of both the connective tissue structures surrounding the myofibres, and the fibroblasts, the cells responsible for synthesising this connective tissue. However, the few studies investigating muscle connective tissue remodelling demonstrate a strong response that appears...

Wavelength-Converter Saving Span Restoration in GMPLS Controlled WDM Optical Networks

DEFF Research Database (Denmark)

Ruepp, Sarah Renée; Buron, Jakob Due; Andriolli, N.

2006-01-01

We present two label preference schemes to reduce wavelength-conversion during restoration path setup in GMPLS controlled optical networks exploiting span restoration. The amount of required wavelength-conversions can be reduced up to 34 percent.......We present two label preference schemes to reduce wavelength-conversion during restoration path setup in GMPLS controlled optical networks exploiting span restoration. The amount of required wavelength-conversions can be reduced up to 34 percent....

Testing for Spanning with Futrures Contracts and Nontraded Assets : A General Approach

NARCIS (Netherlands)

Nijman, T.E.; de Roon, F.A.; Werker, B.J.M.

1996-01-01

This paper generalizes the notion of mean-variance spanning as de- ned in the seminal paper of Huberman & Kandel (1987) in three di- mensions.It is shown how regression techniques can be used to test for spanning for more general classes of utility functions, in case some as- sets are nontraded, and

Structural and functional connectivity as a driver of hillslope erosion following disturbance

Science.gov (United States)

C. Jason Williams; Frederick B. Pierson; Pete Robichaud; Osama Z. Al-Hamdan; Jan Boll; Eva K. Strand

2016-01-01

Hydrologic response to rainfall on fragmented or burnt hillslopes is strongly influenced by the ensuing connectivity of runoff and erosion processes. Yet cross-scale process connectivity is seldom evaluated in field studies owing to scale limitations in experimental design. This study quantified surface susceptibility and hydrologic response across point to...

Herbal supplement extends life span under some environmental conditions and boosts stress resistance.

Directory of Open Access Journals (Sweden)

Bryant Villeponteau

Full Text Available Genetic studies indicate that aging is modulated by a great number of genetic pathways. We have used Drosophila longevity and stress assays to test a multipath intervention strategy. To carry out this strategy, we supplemented the flies with herbal extracts (SC100 that are predicted to modulate the expression of many genes involved in aging and stress resistance, such as mTOR, NOS, NF-KappaB, and VEGF. When flies were housed in large cages with SC100 added, daily mortality rates of both male and female flies were greatly diminished in mid to late life. Surprisingly, SC100 also stabilized midlife mortality rate increases so as to extend the maximum life span substantially beyond the limits previously reported for D. melanogaster. Under these conditions, SC100 also promoted robust resistance to partial starvation stress and to heat stress. Fertility was the same initially in both treated and control flies, but it became significantly higher in treated flies at older ages as the fertility of control flies declined. Mean and maximum life spans of flies in vials at the same test site were also extended by SC100, but the life spans were short in absolute terms. In contrast, at an independent test site where stress was minimized, the flies exhibited much longer mean life spans, but the survival curves became highly rectangular and the effects of SC100 on both mean and maximum life spans declined greatly or were abolished. The data indicate that SC100 is a novel herbal mix with striking effects on enhancing Drosophila stress resistance and life span in some environments, while minimizing mid to late life mortality rates. They also show that the environment and other factors can have transformative effects on both the length and distribution of survivorship, and on the ability of SC100 to extend the life span.

Recognition memory span in autopsy-confirmed Dementia with Lewy Bodies and Alzheimer's Disease.

Science.gov (United States)

Salmon, David P; Heindel, William C; Hamilton, Joanne M; Vincent Filoteo, J; Cidambi, Varun; Hansen, Lawrence A; Masliah, Eliezer; Galasko, Douglas

2015-08-01

Evidence from patients with amnesia suggests that recognition memory span tasks engage both long-term memory (i.e., secondary memory) processes mediated by the diencephalic-medial temporal lobe memory system and working memory processes mediated by fronto-striatal systems. Thus, the recognition memory span task may be particularly effective for detecting memory deficits in disorders that disrupt both memory systems. The presence of unique pathology in fronto-striatal circuits in Dementia with Lewy Bodies (DLB) compared to AD suggests that performance on the recognition memory span task might be differentially affected in the two disorders even though they have quantitatively similar deficits in secondary memory. In the present study, patients with autopsy-confirmed DLB or AD, and Normal Control (NC) participants, were tested on separate recognition memory span tasks that required them to retain increasing amounts of verbal, spatial, or visual object (i.e., faces) information across trials. Results showed that recognition memory spans for verbal and spatial stimuli, but not face stimuli, were lower in patients with DLB than in those with AD, and more impaired relative to NC performance. This was despite similar deficits in the two patient groups on independent measures of secondary memory such as the total number of words recalled from long-term storage on the Buschke Selective Reminding Test. The disproportionate vulnerability of recognition memory span task performance in DLB compared to AD may be due to greater fronto-striatal involvement in DLB and a corresponding decrement in cooperative interaction between working memory and secondary memory processes. Assessment of recognition memory span may contribute to the ability to distinguish between DLB and AD relatively early in the course of disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

Weak and strong coupling equilibration in nonabelian gauge theories

Energy Technology Data Exchange (ETDEWEB)

Keegan, Liam [Physics Department, Theory Unit, CERN,CH-1211 Genève 23 (Switzerland); Kurkela, Aleksi [Physics Department, Theory Unit, CERN,CH-1211 Genève 23 (Switzerland); Faculty of Science and Technology, University of Stavanger,4036 Stavanger (Norway); Romatschke, Paul [Department of Physics, 390 UCB, University of Colorado at Boulder,Boulder, CO (United States); Center for Theory of Quantum Matter, University of Colorado,Boulder, Colorado 80309 (United States); Schee, Wilke van der [Center for Theoretical Physics, MIT,Cambridge, MA 02139 (United States); Zhu, Yan [Department of Physics, University of Jyväskyla, P.O. Box 35, FI-40014 University of Jyväskylä (Finland); Helsinki Institute of Physics,P.O. Box 64, 00014 University of Helsinki (Finland)

2016-04-06

We present a direct comparison studying equilibration through kinetic theory at weak coupling and through holography at strong coupling in the same set-up. The set-up starts with a homogeneous thermal state, which then smoothly transitions through an out-of-equilibrium phase to an expanding system undergoing boost-invariant flow. This first apples-to-apples comparison of equilibration provides a benchmark for similar equilibration processes in heavy-ion collisions, where the equilibration mechanism is still under debate. We find that results at weak and strong coupling can be smoothly connected by simple, empirical power-laws for the viscosity, equilibration time and entropy production of the system.

Weak and strong coupling equilibration in nonabelian gauge theories

International Nuclear Information System (INIS)

Keegan, Liam; Kurkela, Aleksi; Romatschke, Paul; Schee, Wilke van der; Zhu, Yan

2016-01-01

We present a direct comparison studying equilibration through kinetic theory at weak coupling and through holography at strong coupling in the same set-up. The set-up starts with a homogeneous thermal state, which then smoothly transitions through an out-of-equilibrium phase to an expanding system undergoing boost-invariant flow. This first apples-to-apples comparison of equilibration provides a benchmark for similar equilibration processes in heavy-ion collisions, where the equilibration mechanism is still under debate. We find that results at weak and strong coupling can be smoothly connected by simple, empirical power-laws for the viscosity, equilibration time and entropy production of the system.

High-Reynolds Number Active Blowing Semi-Span Force Measurement System Development

Science.gov (United States)

Lynn, Keith C.; Rhew, Ray D.; Acheson, Michael J.; Jones, Gregory S.; Milholen, William E.; Goodliff, Scott L.

2012-01-01

Recent wind-tunnel tests at the NASA Langley Research Center National Transonic Facility utilized high-pressure bellows to route air to the model for evaluating aircraft circulation control. The introduction of these bellows within the Sidewall Model Support System significantly impacted the performance of the external sidewall mounted semi-span balance. As a result of this impact on the semi-span balance measurement performance, it became apparent that a new capability needed to be built into the National Transonic Facility s infrastructure to allow for performing pressure tare calibrations on the balance in order to properly characterize its performance under the influence of static bellows pressure tare loads and bellows thermal effects. The objective of this study was to design both mechanical calibration hardware and an experimental calibration design that can be employed at the facility in order to efficiently and precisely perform the necessary loadings in order to characterize the semi-span balance under the influence of multiple calibration factors (balance forces/moments and bellows pressure/temperature). Using statistical design of experiments, an experimental design was developed allowing for strategically characterizing the behavior of the semi-span balance for use in circulation control and propulsion-type flow control testing at the National Transonic Facility.

Restoring speech perception with cochlear implants by spanning defective electrode contacts.

Science.gov (United States)

Frijns, Johan H M; Snel-Bongers, Jorien; Vellinga, Dirk; Schrage, Erik; Vanpoucke, Filiep J; Briaire, Jeroen J

2013-04-01

Even with six defective contacts, spanning can largely restore speech perception with the HiRes 120 speech processing strategy to the level supported by an intact electrode array. Moreover, the sound quality is not degraded. Previous studies have demonstrated reduced speech perception scores (SPS) with defective contacts in HiRes 120. This study investigated whether replacing defective contacts by spanning, i.e. current steering on non-adjacent contacts, is able to restore speech recognition to the level supported by an intact electrode array. Ten adult cochlear implant recipients (HiRes90K, HiFocus1J) with experience with HiRes 120 participated in this study. Three different defective electrode arrays were simulated (six separate defective contacts, three pairs or two triplets). The participants received three take-home strategies and were asked to evaluate the sound quality in five predefined listening conditions. After 3 weeks, SPS were evaluated with monosyllabic words in quiet and in speech-shaped background noise. The participants rated the sound quality equal for all take-home strategies. SPS with background noise were equal for all conditions tested. However, SPS in quiet (85% phonemes correct on average with the full array) decreased significantly with increasing spanning distance, with a 3% decrease for each spanned contact.

Developments and Prospects of Long-Span High-Speed Railway Bridge Technologies in China

OpenAIRE

Shunquan Qin; Zongyu Gao

2017-01-01

With the rapid developments of the high-speed railway in China, a great number of long-span bridges have been constructed in order to cross rivers and gorges. At present, the longest main span of a constructed high-speed railway bridge is only 630 m. The main span of Hutong Yangtze River Bridge and of Wufengshan Yangtze River Bridge, which are under construction, will be much longer, at 1092 m each. In order to overcome the technical issues that originate from the extremely large dead loading...

Orion: a glimpse of hope in life span extension?

Science.gov (United States)

Muradian, K; Bondar, V; Bezrukov, V; Zhukovsky, O; Polyakov, V; Utko, N

2010-01-01

Orion is a multicomponent drug based on derivatives of taurocholic acid and several other compounds. Application of Orion into the feeding medium of Drosophila melanogaster resulted in increased life span and survival at stressful conditions. Two paradoxical features of the drug should be stressed: The "age-threshold" (life span extension was observed only when the drug was applied starting from the second half of life) and induction of "centenarian" flies (older 100 days). Orion enhanced survival at heat shock (38 degrees C) and acidic (pH = 1.6) or alkaline (pH = 11.8) feeding mediums, but not at oxidative stresses modeled by 100% oxygen or application of hydrogen peroxide (H(2)O(2)).

Post-Tensioned Concrete Long-Span Slabs in Projects of Modern Building Construction

Science.gov (United States)

Szydlowski, Rafal; Labuzek, Barbara

2017-10-01

Nowadays, design of modern an architectural building structures requires the use of slender and free from numerous supports slabs. The most suitable solution for above requirements are the post-tensioned slabs with unbounded tendons. Slabs prestressed by unbounded tendons are successfully used worldwide for several decades. During that time many recommendations dealing with the forming of geometry and prestressing, dimensioning and erection technology were issued. During the recent years prestressed slabs characterized by span and slenderness substantially exceeding recommended limitations were designed and erected with success in Poland. During the slabs erection and in two years of their using, the deflection of three oversized slabs were monitoring. In spite of designed the slabs significantly larger and slenderer than the recommended maximum value of span and span to depth ratio, the deflection of the slabs is definitely far from the limit value. The paper shows the geometry, characteristic and deflection of erected slabs and conclusion. Description of a very large span slab (21.3m), that was designed regarded to the information obtained from the previous realisation, is presented in this paper.

Front-line managers as boundary spanners: effects of span and time on nurse supervision satisfaction.

Science.gov (United States)

Meyer, Raquel M; O'Brien-Pallas, Linda; Doran, Diane; Streiner, David; Ferguson-Paré, Mary; Duffield, Christine

2011-07-01

To examine the influence of nurse manager span (number of direct report staff), time in staff contact, transformational leadership practices and operational hours on nurse supervision satisfaction. Increasing role complexity has intensified the boundary spanning functions of managers. Because work demands and scope vary by management position, time in staff contact rather than span may better explain managers' capacity to support staff. A descriptive, correlational design was used to collect cross-sectional survey and prospective work log and administrative data from a convenience sample of 558 nurses in 51 clinical areas and 31 front-line nurse managers from four acute care hospitals in 2007-2008. Data were analysed using hierarchical linear modelling. Span, but not time in staff contact, interacted with leadership and operational hours to explain supervision satisfaction. With compressed operational hours, supervision satisfaction was lower with highly transformational leadership in combination with wider spans. With extended operational hours, supervision satisfaction was higher with highly transformational leadership, and this effect was more pronounced under wider spans. Operational hours, which influence the manager's daily span (average number of direct report staff working per weekday), should be factored into the design of front-line management positions. © 2011 The Authors. Journal compilation © 2011 Blackwell Publishing Ltd.

Strong, reliable and precise synaptic connections between thalamic relay cells and neurones of the nucleus reticularis in juvenile rats

Science.gov (United States)

Gentet, Luc J; Ulrich, Daniel

2003-01-01

The thalamic reticular nucleus (nRT) is composed entirely of GABAergic inhibitory neurones that receive input from pyramidal cortical neurones and excitatory relay cells of the ventrobasal complex of the thalamus (VB). It plays a major role in the synchrony of thalamic networks, yet the synaptic connections it receives from VB cells have never been fully physiologically characterised. Here, whole-cell current-clamp recordings were obtained from 22 synaptically connected VB-nRT cell pairs in slices of juvenile (P14–20) rats. At 34–36 °C, single presynaptic APs evoked unitary EPSPs in nRT cells with a peak amplitude of 7.4 ± 1.5 mV (mean ± s.e.m.) and a decay time constant of 15.1 ± 0.9 ms. Only four out of 22 pairs showed transmission failures at a mean rate of 6.8 ± 1.1 %. An NMDA receptor (NMDAR)-mediated component was significant at rest and subsequent EPSPs in a train were depressed. Only one out of 14 pairs tested was reciprocally connected; the observed IPSPs in the VB cell had a peak amplitude of 0.8 mV and were completely abolished in the presence of 10 μm bicuculline. Thus, synaptic connections from VB cells to nRT neurones are mainly ‘drivers’, while a small subset of cells form closed disynaptic loops. PMID:12563005

Connectivity effects in the dynamic model of neural networks

International Nuclear Information System (INIS)

Choi, J; Choi, M Y; Yoon, B-G

2009-01-01

We study, via extensive Monte Carlo calculations, the effects of connectivity in the dynamic model of neural networks, to observe that the Mattis-state order parameter increases with the number of coupled neurons. Such effects appear more pronounced when the average number of connections is increased by introducing shortcuts in the network. In particular, the power spectra of the order parameter at stationarity are found to exhibit power-law behavior, depending on how the average number of connections is increased. The cluster size distribution of the 'memory-unmatched' sites also follows a power law and possesses strong correlations with the power spectra. It is further observed that the distribution of waiting times for neuron firing fits roughly to a power law, again depending on how neuronal connections are increased

Development of Shear Connections in Steelconcrete Composite Structures

Science.gov (United States)

Biegus, Antoni; Lorenc, Wojciech

2015-03-01

Different types of shear connectors and modelling techniques are presented. Basic research conducted or presented after year 2000 is taken into consideration, following the idea of concrete dowel implemented in the form of perfobond strip at the beginning of the 1980s by F. Leonhardt. The latest research in the field of continuous shear connectors applied in bridges is highlited with special focus at the composite dowel shear connection, as it seems to be the most modern solution being strongly introduced to the industry. Final shape of composite dowel shear connection is presented.

Political connections, media monitoring and long-term loans

Institute of Scientific and Technical Information of China (English)

Deming; Yang; Zhengfei; Lu; Danglun; Luo

2014-01-01

We analyze data on Chinese non-state-listed firms and find that it is easier for firms with political connections to obtain long-term loans with extended debt maturities than it is for firms without political connections. Our investigation indicates that this phenomenon is significantly less common with increased media monitoring. Houston et al.(2011) find strong evidence that the state ownership of media is associated with higher levels of bank corruption in China, but our study shows that, to a certain extent, media monitoring can curb corruption.

Political connections, media monitoring and long-term loans

Directory of Open Access Journals (Sweden)

Deming Yang

2014-09-01

Full Text Available We analyze data on Chinese non-state-listed firms and find that it is easier for firms with political connections to obtain long-term loans with extended debt maturities than it is for firms without political connections. Our investigation indicates that this phenomenon is significantly less common with increased media monitoring. Houston et al. (2011 find strong evidence that the state ownership of media is associated with higher levels of bank corruption in China, but our study shows that, to a certain extent, media monitoring can curb corruption.

Genetic manipulation of longevity-related genes as a tool to regulate yeast life span and metabolite production during winemaking.

Science.gov (United States)

Orozco, Helena; Matallana, Emilia; Aranda, Agustín

2013-01-02

Yeast viability and vitality are essential for different industrial processes where the yeast Saccharomyces cerevisiae is used as a biotechnological tool. Therefore, the decline of yeast biological functions during aging may compromise their successful biotechnological use. Life span is controlled by a variety of molecular mechanisms, many of which are connected to stress tolerance and genomic stability, although the metabolic status of a cell has proven a main factor affecting its longevity. Acetic acid and ethanol accumulation shorten chronological life span (CLS), while glycerol extends it. Different age-related gene classes have been modified by deletion or overexpression to test their role in longevity and metabolism. Overexpression of histone deacetylase SIR2 extends CLS and reduces acetate production, while overexpression of SIR2 homolog HST3 shortens CLS, increases the ethanol level, and reduces acetic acid production. HST3 overexpression also enhances ethanol tolerance. Increasing tolerance to oxidative stress by superoxide dismutase SOD2 overexpression has only a moderate positive effect on CLS. CLS during grape juice fermentation has also been studied for mutants on several mRNA binding proteins that are regulators of gene expression at the posttranscriptional level; we found that NGR1 and UTH4 deletions decrease CLS, while PUF3 and PUB1 deletions increase it. Besides, the pub1Δ mutation increases glycerol production and blocks stress granule formation during grape juice fermentation. Surprisingly, factors relating to apoptosis, such as caspase Yca1 or apoptosis-inducing factor Aif1, play a positive role in yeast longevity during winemaking as their deletions shorten CLS. Manipulation of regulators of gene expression at both transcriptional (i.e., sirtuins) and posttranscriptional (i.e., mRNA binding protein Pub1) levels allows to modulate yeast life span during its biotechnological use. Due to links between aging and metabolism, it also influences the

Looking for an Explanation for the Low Sign Span. Is Order Involved?

Science.gov (United States)

Gozzi, Marta; Geraci, Carlo; Cecchetto, Carlo; Perugini, Marco; Papagno, Costanza

2011-01-01

Although signed and speech-based languages have a similar internal organization of verbal short-term memory, sign span is lower than word span. We investigated whether this is due to the fact that signs are not suited for serial recall, as proposed by Bavelier, Newport, Hall, Supalla, and Boutla (2008. Ordered short-term memory differs in signers…

Dynamic adaptation of tendon and muscle connective tissue to mechanical loading

DEFF Research Database (Denmark)

Mackey, Abigail; Heinemeier, Katja Maria; Koskinen, Satu Osmi Anneli

2008-01-01

The connective tissue of tendon and skeletal muscle is a crucial structure for force transmission. A dynamic adaptive capacity of these tissues in healthy individuals is evident from reports of altered gene expression and protein levels of the fibrillar and network-forming collagens, when subjected...... in this article provide strong evidence for the highly adaptable nature of connective tissue in muscle and tendon....

Characterisation of minimal-span plane Couette turbulence with pressure gradients

Science.gov (United States)

Sekimoto, Atsushi; Atkinson, Callum; Soria, Julio

2018-04-01

The turbulence statistics and dynamics in the spanwise-minimal plane Couette flow with pressure gradients, so-called, Couette-Poiseuille (C-P) flow, are investigated using direct numerical simulation. The large-scale motion is limited in the spanwise box dimension as in the minimal-span channel turbulence of Flores & Jiménez (Phys. Fluids, vol. 22, 2010, 071704). The effect of the top wall, where normal pressure-driven Poiseuille flow is realised, is distinguished from the events on the bottom wall, where the pressure gradient results in mild or almost-zero wall-shear stress. A proper scaling of turbulence statistics in minimal-span C-P flows is presented. Also the ‘shear-less’ wall-bounded turbulence, where the Corrsin shear parameter is very weak compared to normal wall-bounded turbulence, represents local separation, which is also observed as spanwise streaks of reversed flow in full-size plane C-P turbulence. The local separation is a multi-scale event, which grows up to the order of the channel height even in the minimal-span geometry.

Short-term memory predictions across the lifespan: monitoring span before and after conducting a task.

Science.gov (United States)

Bertrand, Julie Marilyne; Moulin, Chris John Anthony; Souchay, Céline

2017-05-01

Our objective was to explore metamemory in short-term memory across the lifespan. Five age groups participated in this study: 3 groups of children (4-13 years old), and younger and older adults. We used a three-phase task: prediction-span-postdiction. For prediction and postdiction phases, participants reported with a Yes/No response if they could recall in order a series of images. For the span task, they had to actually recall such series. From 4 years old, children have some ability to monitor their short-term memory and are able to adjust their prediction after experiencing the task. However, accuracy still improves significantly until adolescence. Although the older adults had a lower span, they were as accurate as young adults in their evaluation, suggesting that metamemory is unimpaired for short-term memory tasks in older adults. •We investigate metamemory for short-term memory tasks across the lifespan. •We find younger children cannot accurately predict their span length. •Older adults are accurate in predicting their span length. •People's metamemory accuracy was related to their short-term memory span.

The visual attention span deficit in Chinese children with reading fluency difficulty.

Science.gov (United States)

Zhao, Jing; Liu, Menglian; Liu, Hanlong; Huang, Chen

2018-02-01

With reading development, some children fail to learn to read fluently. However, reading fluency difficulty (RFD) has not been fully investigated. The present study explored the underlying mechanism of RFD from the aspect of visual attention span. Fourteen Chinese children with RFD and fourteen age-matched normal readers participated. The visual 1-back task was adopted to examine visual attention span. Reaction time and accuracy were recorded, and relevant d-prime (d') scores were computed. Results showed that children with RFD exhibited lower accuracy and lower d' values than the controls did in the visual 1-back task, revealing a visual attention span deficit. Further analyses on d' values revealed that the attention distribution seemed to exhibit an inverted U-shaped pattern without lateralization for normal readers, but a W-shaped pattern with a rightward bias for children with RFD, which was discussed based on between-group variation in reading strategies. Results of the correlation analyses showed that visual attention span was associated with reading fluency at the sentence level for normal readers, but was related to reading fluency at the single-character level for children with RFD. The different patterns in correlations between groups revealed that visual attention span might be affected by the variation in reading strategies. The current findings extend previous data from alphabetic languages to Chinese, a logographic language with a particularly deep orthography, and have implications for reading-dysfluency remediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Frontoparietal Structural Connectivity in Childhood Predicts Development of Functional Connectivity and Reasoning Ability: A Large-Scale Longitudinal Investigation.

Science.gov (United States)

Wendelken, Carter; Ferrer, Emilio; Ghetti, Simona; Bailey, Stephen K; Cutting, Laurie; Bunge, Silvia A

2017-08-30

Prior research points to a positive concurrent relationship between reasoning ability and both frontoparietal structural connectivity (SC) as measured by diffusion tensor imaging (Tamnes et al., 2010) and frontoparietal functional connectivity (FC) as measured by fMRI (Cocchi et al., 2014). Further, recent research demonstrates a link between reasoning ability and FC of two brain regions in particular: rostrolateral prefrontal cortex (RLPFC) and the inferior parietal lobe (IPL) (Wendelken et al., 2016). Here, we sought to investigate the concurrent and dynamic, lead-lag relationships among frontoparietal SC, FC, and reasoning ability in humans. To this end, we combined three longitudinal developmental datasets with behavioral and neuroimaging data from 523 male and female participants between 6 and 22 years of age. Cross-sectionally, reasoning ability was most strongly related to FC between RLPFC and IPL in adolescents and adults, but to frontoparietal SC in children. Longitudinal analysis revealed that RLPFC-IPL SC, but not FC, was a positive predictor of future changes in reasoning ability. Moreover, we found that RLPFC-IPL SC at one time point positively predicted future changes in RLPFC-IPL FC, whereas, in contrast, FC did not predict future changes in SC. Our results demonstrate the importance of strong white matter connectivity between RLPFC and IPL during middle childhood for the subsequent development of both robust FC and good reasoning ability. SIGNIFICANCE STATEMENT The human capacity for reasoning develops substantially during childhood and has a profound impact on achievement in school and in cognitively challenging careers. Reasoning ability depends on communication between lateral prefrontal and parietal cortices. Therefore, to understand how this capacity develops, we examined the dynamic relationships over time among white matter tracts connecting frontoparietal cortices (i.e., structural connectivity, SC), coordinated frontoparietal activation

Dominance of strong absorption in 9Be + 28Si elastic scattering

International Nuclear Information System (INIS)

Zisman, M.S.; Cramer, J.G.; DeVries, R.M.; Goldberg, D.A.; Watson, J.W.

1979-07-01

Because the character of the scattering changes markedly from 6 Li to 12 C projectiles, a study of the 9 Be + 28 Si system was undertaken to examine the transition region. Data were measured at 121.0 and 201.6 MeV. Low-energy data of other investigators were used to carry out global optical model searches. It was found that the elastic scattering of 9 Be from 28 Si is dominated at all energies by relatively strong absorption. This removes much of the sensitivity to the real potential, and even elastic scattering data spanning a range of energies from 13 to 201 MeV do not allow a unique determination of the potential parameters. There is at least circumstantial evidence that 6 Li scattering at low energies (and by implication also 9 Be scattering) may be strongly influenced by breakup processes, although it is not clear that the mechanism is the same. 3 figures, 1 table

Data-Intensive Cloud Service Provision for Research Institutes: the Network Connectivity Problem

CERN Document Server

Cass, Tony; CERN. Geneva. IT Department

2016-01-01

Much effort (and money) has been invested in recent years to ensure that academic and research sites are well interconnected with high-capacity networks that, in most cases, span national and continental boundaries. However, these dedicated research and education networks, whether national (NRENs) or trans-continental (RENs), frequently have Acceptable Use Policies (AUPs) that restrict their use by commercial entities, notably Cloud Service Providers (CSPs). After a brief summary of the issues involved, we describe three approaches to removing the network connectivity barrier that threatens to limit the ability of academic and research institutions to profit effectively from services offered by CSPs.

Analysis of protection spanning-tree protocol

Directory of Open Access Journals (Sweden)

Б.Я. Корнієнко

2007-01-01

Full Text Available  Extraordinary sweeping  of  IT – development  causes vulnerabilities and, thereafter, attacks that use these vulnerabilities. That is why one must post factum or even in advance speed up invention of new information  security systems as well as develop the old ones. The matter of article concerns Spanning-Tree Protocol  – the vivid example of the case, when the cure of the vulnerability creates dozen of new "weak spots".

Evaluating the life cycle environmental impact of short span bridges

DEFF Research Database (Denmark)

Du, Guangli; Pettersson, Lars; Karoumi, Raid

2016-01-01

impact of the construction sector. Life cycle assessment (LCA) is a systematic method for assessing the environmental impact of products and systems, but its application in bridges is scarce. In Swede, most of the bridges are short spans and the type of concrete slab-frame bridge (CFB) accounts...... for a large share. Soil steel composite bridge (SSCB) is a functional equivalent solution for CFB. In order to mitigate the environmental burdens of short span bridges, this paper performed a comparative LCA study between these two types of bridge. The results indicate that the initial material consumption...

Comparing Repaired and Undamaged Specimens Test Results of Post-Tensioned Beam to Column Connections

OpenAIRE

Mustafa Kaya

2015-01-01

Since, it is essential to provide homeless people by the earthquake with safe, habitable accommodation repairing medium and slight levels of damage at the connection parts should be undertaken. In order to prove that a repaired connection was sufficiently strong, a precast beam to column post tensioned connection was tested in three phases. In phase one, the middle level damage was observed at 6% drift at these connections. As a result of the extra loads applied, little d...

Dense neuron clustering explains connectivity statistics in cortical microcircuits.

Directory of Open Access Journals (Sweden)

Vladimir V Klinshov

Full Text Available Local cortical circuits appear highly non-random, but the underlying connectivity rule remains elusive. Here, we analyze experimental data observed in layer 5 of rat neocortex and suggest a model for connectivity from which emerge essential observed non-random features of both wiring and weighting. These features include lognormal distributions of synaptic connection strength, anatomical clustering, and strong correlations between clustering and connection strength. Our model predicts that cortical microcircuits contain large groups of densely connected neurons which we call clusters. We show that such a cluster contains about one fifth of all excitatory neurons of a circuit which are very densely connected with stronger than average synapses. We demonstrate that such clustering plays an important role in the network dynamics, namely, it creates bistable neural spiking in small cortical circuits. Furthermore, introducing local clustering in large-scale networks leads to the emergence of various patterns of persistent local activity in an ongoing network activity. Thus, our results may bridge a gap between anatomical structure and persistent activity observed during working memory and other cognitive processes.

Cross-language modulation of visual attention span: An Arabic-French-Spanish comparison in adult skilled readers.

Directory of Open Access Journals (Sweden)

Faris Haroon Rasheed Awadh

2016-03-01

Full Text Available In delineating the amount of orthographic information that can be processed in parallel during a single fixation, the visual attention (VA span acts as a key component of the reading system. Previous studies focused on the contribution of VA span to normal and pathological reading in monolingual and bilingual children from different European languages, without direct cross-language comparison. In the current paper, we explored modulations of VA span abilities in three languages --French, Spanish and Arabic-- that differ in transparency, reading direction and writing systems. The participants were adult skilled readers who were native speakers of French, Spanish or Arabic. They were administered tasks of global and partial letter report, single letter identification and text reading. Their VA span abilities were assessed using tasks that require the processing of briefly presented 5 consonant strings (e.g., R S H F T. All five consonants had to be reported in global report but a single cued letter in partial report. Results showed that the VA span was reduced in Arabic readers as compared to French or Spanish readers who otherwise show a similar high performance in the two report tasks. The analysis of VA span response patterns in global report showed a left-right asymmetry in all three languages. A leftward letter advantage was found in French and Spanish but a rightward advantage in Arabic. The response patterns were symmetric in partial report, regardless of the language. Last, a significant relationship was found between visual attention span abilities and reading speed but only for French. The overall findings suggest that the size of VA span, the shape of VA span response patterns and the VA Span-reading relationship are modulated by language-specific features.

Cross-Language Modulation of Visual Attention Span: An Arabic-French-Spanish Comparison in Skilled Adult Readers.

Science.gov (United States)

Awadh, Faris H R; Phénix, Thierry; Antzaka, Alexia; Lallier, Marie; Carreiras, Manuel; Valdois, Sylviane

2016-01-01

In delineating the amount of orthographic information that can be processed in parallel during a single fixation, the visual attention (VA) span acts as a key component of the reading system. Previous studies focused on the contribution of VA span to normal and pathological reading in monolingual and bilingual children from different European languages, without direct cross-language comparison. In the current paper, we explored modulations of VA span abilities in three languages -French, Spanish, and Arabic- that differ in transparency, reading direction and writing systems. The participants were skilled adult readers who were native speakers of French, Spanish or Arabic. They were administered tasks of global and partial letter report, single letter identification and text reading. Their VA span abilities were assessed using tasks that require the processing of briefly presented five consonant strings (e.g., R S H F T). All five consonants had to be reported in global report but a single cued letter in partial report. Results showed that VA span was reduced in Arabic readers as compared to French or Spanish readers who otherwise show a similar high performance in the two report tasks. The analysis of VA span response patterns in global report showed a left-right asymmetry in all three languages. A leftward letter advantage was found in French and Spanish but a rightward advantage in Arabic. The response patterns were symmetric in partial report, regardless of the language. Last, a significant relationship was found between VA span abilities and reading speed but only for French. The overall findings suggest that the size of VA span, the shape of VA span response patterns and the VA Span-reading relationship are modulated by language-specific features.

Super-light SL-Deck elements with fixed end connections

DEFF Research Database (Denmark)

Hertz, Kristian Dahl

2015-01-01

Super-light structures combining light and strong concrete are invented by the author at the Technical University of Denmark and commercialized by the spin-out company Abeo Ltd. The first product is the SL-Deck element that represents a number of strong improvements to the building industry among...... to low weight and due to possibilities of continuous elements and fixed end connections. A new machine is constructed producing the elements and BIM software is developed optimizing the structures, the production, and the logistics and running the machine. New production lines are established...... building projects leading to considerable savings of time and costs and opening up new possibilities for architects and users. Furthermore, the paper describes full-scale test results with new fixed end connections between decks and walls and between decks and columns in facades giving more possibilities...

Generating mid-IR octave-spanning supercontinua and few-cycle pulses with solitons in phase-mismatched quadratic nonlinear crystals

DEFF Research Database (Denmark)

Bache, Morten; Guo, Hairun; Zhou, Binbin

2013-01-01

We discuss a novel method for generating octave-spanning supercontinua and few-cycle pulses in the important mid-IR wavelength range. The technique relies on strongly phase-mismatched cascaded second-harmonic generation (SHG) in mid-IR nonlinear frequency conversion crystals. Importantly we here...... of the promising crystals: in one case soliton pulse compression from 50 fs to 15 fs (1.5 cycles) at 3.0 μm is achieved, and at the same time a 3-cycle dispersive wave at 5.0 μm is formed that can be isolated using a long-pass filter. In another example we show that extremely broadband supercontinua can form...

Markov models for fMRI correlation structure: Is brain functional connectivity small world, or decomposable into networks?

Science.gov (United States)

Varoquaux, G; Gramfort, A; Poline, J B; Thirion, B

2012-01-01

Correlations in the signal observed via functional Magnetic Resonance Imaging (fMRI), are expected to reveal the interactions in the underlying neural populations through hemodynamic response. In particular, they highlight distributed set of mutually correlated regions that correspond to brain networks related to different cognitive functions. Yet graph-theoretical studies of neural connections give a different picture: that of a highly integrated system with small-world properties: local clustering but with short pathways across the complete structure. We examine the conditional independence properties of the fMRI signal, i.e. its Markov structure, to find realistic assumptions on the connectivity structure that are required to explain the observed functional connectivity. In particular we seek a decomposition of the Markov structure into segregated functional networks using decomposable graphs: a set of strongly-connected and partially overlapping cliques. We introduce a new method to efficiently extract such cliques on a large, strongly-connected graph. We compare methods learning different graph structures from functional connectivity by testing the goodness of fit of the model they learn on new data. We find that summarizing the structure as strongly-connected networks can give a good description only for very large and overlapping networks. These results highlight that Markov models are good tools to identify the structure of brain connectivity from fMRI signals, but for this purpose they must reflect the small-world properties of the underlying neural systems. Copyright © 2012 Elsevier Ltd. All rights reserved.

Electrical performance of conducting polymer (SPAN) grown on GaAs with different substrate orientations

Science.gov (United States)

Jameel, D. A.; Aziz, M.; Felix, J. F.; Al Saqri, N.; Taylor, D.; Albalawi, H.; Alghamdi, H.; Al Mashary, F.; Henini, M.

2016-11-01

This article reports the effect of n-type GaAs substrate orientation, namely (100), (311)A and (311)B, on the electrical properties of sulfonated polyaniline (SPAN)/GaAs heterojunction devices. In addition, the inhomogeneity of the interface between various GaAs substrates and SPAN is investigated in terms of barrier height and ideality factor by performing I-V measurements at different temperatures (20-420 K). The I-V results indicate that the value of the rectification ratio (IF/IR) at 0.5 V is higher for SPAN/(311)B GaAs samples than for SPAN/(100) GaAs and SPAN/(311)A GaAs samples. Moreover, the barrier height decreases and the ideality factor increases with decreasing temperature for all three heterostructure devices. The high value of mean barrier Φbarb of SPAN/(311)B (calculated from the plots of Φb 0 as a function of 1/2kT) confirms that the GaAs substrate orientation results in an increase of barrier homogeneities. Furthermore, the C-V characteristics were obtained at room temperature. The C-V measurements showed that the carrier distributions at the interface and away from the interface in high index (311) GaAs orientations are more uniform and have better barrier homogeneity than those grown on the conventional (100) GaAs substrates.

DIRECT SELECTION ON LIFE-SPAN IN DROSOPHILA-MELANOGASTER

NARCIS (Netherlands)

ZWAAN, B; BIJLSMA, R; HOEKSTRA, RE

An important issue in the study of the evolution of aging in Drosophila melanogaster is whether decreased early fecundity is inextricably coupled with increased life span in selection experiments on age at reproduction. Here, this problem has been tackled using an experimental design in which

Life span effects of Hypericum perforatum extracts on Caenorhabditis elegans under heat stress.

Science.gov (United States)

Kılıçgün, Hasan; Göksen, Gülden

2012-10-01

The beneficial effects of antioxidants in plants are mainly extrapolated from in vitro studies or short-term dietary supplementation studies. Due to cost and duration, relatively little is known about whether dietary antioxidants are beneficial in whole animals' life span or not. To address this question, under heat stress (35°C), Hypericum perforatum was extracted with petroleum ether and the nematodes Caenorhabditis elegans exposed to three different extract concentrations (1mg/mL, 0.1mg/mL, 0.01mg/mL) of H. perforatum. We report that Hypericum perforatum extracts did not increase life span and slow aging related increase in C. elegans. Moreover, one fraction (1mg/mL) increased declines of C. elegans life span and thermotolerance. Given this mounting evidence for life span role of H. perforatum in the presence of heat stress in vivo, the question whether H. perforatum acts as a prooxidant or an antioxidant in vivo under heat stress arises.

Evolution of static allometries: adaptive change in allometric slopes of eye span in stalk-eyed flies.

Science.gov (United States)

Voje, Kjetil L; Hansen, Thomas F

2013-02-01

Julian Huxley showed that within-species (static) allometric (power-law) relations can arise from proportional growth regulation with the exponent in the power law equaling the factor of proportionality. Allometric exponents may therefore be hard to change and act as constraints on the independent evolution of traits. In apparent contradiction to this, many empirical studies have concluded that static allometries are evolvable. Many of these studies have been based, however, on a broad definition of allometry that includes any monotonic shape change with size, and do not falsify the hypothesis of constrained narrow-sense allometry. Here, we present the first phylogenetic comparative study of narrow-sense allometric exponents based on a reanalysis of data on eye span and body size in stalk-eyed flies (Diopsidae). Consistent with a role in sexual selection, we found strong evidence that male slopes were tracking "optima" based on sexual dimorphism and relative male trait size. This tracking was slow, however, with estimated times of 2-3 million years for adaptation to exceed ancestral influence on the trait. Our results are therefore consistent with adaptive evolution on million-year time scales, but cannot rule out that static allometry may act as a constraint on eye-span adaptation at shorter time scales. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

Processing Efficiency in Preschoolers' Memory Span: Individual Differences Related to Age and Anxiety

Science.gov (United States)

Visu-Petra, Laura; Miclea, Mircea; Cheie, Lavinia; Benga, Oana

2009-01-01

In self-paced auditory memory span tasks, the microanalysis of response timing measures represents a developmentally sensitive measure, providing insights into the development of distinct processing rates during recall performance. The current study first examined the effects of age and trait anxiety on span accuracy (effectiveness) and response…

'Localised creativity: a life span perspective'

OpenAIRE

Worth, Piers J.

2000-01-01

This thesis is based around a biographic study of the lives of 40 individuals (24 men and 16 women) with a reputation for creative work in a localised context (such as an organisation). The study examines life span development patterns from birth to middle age (45 - 60 years of age) with data gained by biographic interview and thematic analysis. Participants selected for this study are creative in that they have a reputation for producing new, novel and useful or appropriate contributions in ...

First-order discrete Faddeev gravity at strongly varying fields

Science.gov (United States)

Khatsymovsky, V. M.

2017-11-01

We consider the Faddeev formulation of general relativity (GR), which can be characterized by a kind of d-dimensional tetrad (typically d = 10) and a non-Riemannian connection. This theory is invariant w.r.t. the global, but not local, rotations in the d-dimensional space. There can be configurations with a smooth or flat metric, but with the tetrad that changes abruptly at small distances, a kind of “antiferromagnetic” structure. Previously, we discussed a first-order representation for the Faddeev gravity, which uses the orthogonal connection in the d-dimensional space as an independent variable. Using the discrete form of this formulation, we considered the spectrum of (elementary) area. This spectrum turns out to be physically reasonable just on a classical background with large connection like rotations by π, that is, with such an “antiferromagnetic” structure. In the discrete first-order Faddeev gravity, we consider such a structure with periodic cells and large connection and strongly changing tetrad field inside the cell. We show that this system in the continuum limit reduces to a generalization of the Faddeev system. The action is a sum of related actions of the Faddeev type and is still reduced to the GR action.

Estimating migratory connectivity of birds when re-encounter probabilities are heterogeneous

Science.gov (United States)

Cohen, Emily B.; Hostelter, Jeffrey A.; Royle, J. Andrew; Marra, Peter P.

2014-01-01

Understanding the biology and conducting effective conservation of migratory species requires an understanding of migratory connectivity – the geographic linkages of populations between stages of the annual cycle. Unfortunately, for most species, we are lacking such information. The North American Bird Banding Laboratory (BBL) houses an extensive database of marking, recaptures and recoveries, and such data could provide migratory connectivity information for many species. To date, however, few species have been analyzed for migratory connectivity largely because heterogeneous re-encounter probabilities make interpretation problematic. We accounted for regional variation in re-encounter probabilities by borrowing information across species and by using effort covariates on recapture and recovery probabilities in a multistate capture–recapture and recovery model. The effort covariates were derived from recaptures and recoveries of species within the same regions. We estimated the migratory connectivity for three tern species breeding in North America and over-wintering in the tropics, common (Sterna hirundo), roseate (Sterna dougallii), and Caspian terns (Hydroprogne caspia). For western breeding terns, model-derived estimates of migratory connectivity differed considerably from those derived directly from the proportions of re-encounters. Conversely, for eastern breeding terns, estimates were merely refined by the inclusion of re-encounter probabilities. In general, eastern breeding terns were strongly connected to eastern South America, and western breeding terns were strongly linked to the more western parts of the nonbreeding range under both models. Through simulation, we found this approach is likely useful for many species in the BBL database, although precision improved with higher re-encounter probabilities and stronger migratory connectivity. We describe an approach to deal with the inherent biases in BBL banding and re-encounter data to demonstrate

Blended Design Approach of Long Span Structure and Malay Traditional Architecture

Science.gov (United States)

Sundari, Titin

2017-12-01

The growing population in the world is so fast, which is followed by the increasing need of some new and large activities. Architects face the problem on how to facilitate buildings with various activities such as for large meeting, conference, indoors gymnasium and sports, and many others. The long span structure of building is one of the solutions to solve that problem. Generally, large buildings which implemented this structure will look as a technological, modern and futuristic ones or even neo futuristic performance. But on the other hand, many people still want to enjoy the specific and unique senses of local traditional architecture. So is the Malay people who want an easy pleasant large facilities which can be fulfilled by implementing modern long span building structure technology. In the same time, their unique sense of Malay traditional architecture can still be maintained. To overcome this double problems of design, it needs a blended design approach of long span structure and Malay Traditional Architecture.

Seismic Performance of Multi-Span RC Railway Bridges

DEFF Research Database (Denmark)

Georgakis, Christos; Barrau, Xavier

2008-01-01

Presently, there is no clear method for determining the optimal railway bridge design for a particular ground type and expected seismic intensity. Four main types of RC bridge dominate the current multi-span railway bridge design trends – the Simply Supported Beam, Continuous Box-Girder (CBG), CBG...

Spanning the Creative Space between Home and Work

DEFF Research Database (Denmark)

Davis, Lee N.; Hoisl, Karin; Davis, Jerome

the employee brings to work. Based on Woodman et al.’s (1993) “interactionist perspective” on organizational creativity, supplemented by literature on search and knowledge/combination, we explore whether leisure time activities can span the creative space between the employee’s home and workplace – given...

Individual differences in memory span: the contribution of rehearsal, access to lexical memory, and output speed.

Science.gov (United States)

Tehan, G; Lalor, D M

2000-11-01

Rehearsal speed has traditionally been seen to be the prime determinant of individual differences in memory span. Recent studies, in the main using young children as the subject population, have suggested other contributors to span performance, notably contributions from long-term memory and forgetting and retrieval processes occurring during recall. In the current research we explore individual differences in span with respect to measures of rehearsal, output time, and access to lexical memory. We replicate standard short-term phenomena; we show that the variables that influence children's span performance influence adult performance in the same way; and we show that lexical memory access appears to be a more potent source of individual differences in span than either rehearsal speed or output factors.

Phonological similarity effect in complex span task.

Science.gov (United States)

Camos, Valérie; Mora, Gérôme; Barrouillet, Pierre

2013-01-01

The aim of our study was to test the hypothesis that two systems are involved in verbal working memory; one is specifically dedicated to the maintenance of phonological representations through verbal rehearsal while the other would maintain multimodal representations through attentional refreshing. This theoretical framework predicts that phonologically related phenomena such as the phonological similarity effect (PSE) should occur when the domain-specific system is involved in maintenance, but should disappear when concurrent articulation hinders its use. Impeding maintenance in the domain-general system by a concurrent attentional demand should impair recall performance without affecting PSE. In three experiments, we manipulated the concurrent articulation and the attentional demand induced by the processing component of complex span tasks in which participants had to maintain lists of either similar or dissimilar words. Confirming our predictions, PSE affected recall performance in complex span tasks. Although both the attentional demand and the articulatory requirement of the concurrent task impaired recall, only the induction of an articulatory suppression during maintenance made the PSE disappear. These results suggest a duality in the systems devoted to verbal maintenance in the short term, constraining models of working memory.

The Problem of Predecessors on Spanning Trees

Directory of Open Access Journals (Sweden)

V. S. Poghosyan

2011-01-01

Full Text Available We consider the equiprobable distribution of spanning trees on the square lattice. All bonds of each tree can be oriented uniquely with respect to an arbitrary chosen site called the root. The problem of predecessors is to find the probability that a path along the oriented bonds passes sequentially fixed sites i and j. The conformal field theory for the Potts model predicts the fractal dimension of the path to be 5/4. Using this result, we show that the probability in the predecessors problem for two sites separated by large distance r decreases as P(r ∼ r −3/4. If sites i and j are nearest neighbors on the square lattice, the probability P(1 = 5/16 can be found from the analytical theory developed for the sandpile model. The known equivalence between the loop erased random walk (LERW and the directed path on the spanning tree states that P(1 is the probability for the LERW started at i to reach the neighboring site j. By analogy with the self-avoiding walk, P(1 can be called the return probability. Extensive Monte-Carlo simulations confirm the theoretical predictions.

Detection of suboptimal effort with symbol span: development of a new embedded index.

Science.gov (United States)

Young, J Christopher; Caron, Joshua E; Baughman, Brandon C; Sawyer, R John

2012-03-01

Developing embedded indicators of suboptimal effort on objective neurocognitive testing is essential for detecting increasingly sophisticated forms of symptom feigning. The current study explored whether Symbol Span, a novel Wechsler Memory Scale-fourth edition measure of supraspan visual attention, could be used to discriminate adequate effort from suboptimal effort. Archival data were collected from 136 veterans classified into Poor Effort (n = 42) and Good Effort (n = 94) groups based on symptom validity test (SVT) performance. The Poor Effort group had significantly lower raw scores (p Span test. A raw score cutoff of Span can effectively differentiate veterans with multiple failures on established free-standing and embedded SVTs.

Grid-connected photovoltaic power systems. Technical and potential problems. A review

International Nuclear Information System (INIS)

Eltawil, Mohamed A.; Zhao, Zhengming

2010-01-01

Traditional electric power systems are designed in large part to utilize large baseload power plants, with limited ability to rapidly ramp output or reduce output below a certain level. The increase in demand variability created by intermittent sources such as photovoltaic (PV) presents new challenges to increase system flexibility. This paper aims to investigate and emphasize the importance of the grid-connected PV system regarding the intermittent nature of renewable generation, and the characterization of PV generation with regard to grid code compliance. The investigation was conducted to critically review the literature on expected potential problems associated with high penetration levels and islanding prevention methods of grid tied PV. According to the survey, PV grid connection inverters have fairly good performance. They have high conversion efficiency and power factor exceeding 90% for wide operating range, while maintaining current harmonics THD less than 5%. Numerous large-scale projects are currently being commissioned, with more planned for the near future. Prices of both PV and balance of system components (BOS) are decreasing which will lead to further increase in use. The technical requirements from the utility power system side need to be satisfied to ensure the safety of the PV installer and the reliability of the utility grid. Identifying the technical requirements for grid interconnection and solving the interconnect problems such as islanding detection, harmonic distortion requirements and electromagnetic interference are therefore very important issues for widespread application of PV systems. The control circuit also provides sufficient control and protection functions like maximum power tracking, inverter current control and power factor control. Reliability, life span and maintenance needs should be certified through the long-term operation of PV system. Further reduction of cost, size and weight is required for more utilization of PV

Classification of locally 2-connected compact metric spaces

DEFF Research Database (Denmark)

Thomassen, Carsten

2005-01-01

The aim of this paper is to prove that, for compact metric spaces which do not contain infinite complete graphs, the (strong) property of being "locally 2-dimensional" is guaranteed just by a (weak) local connectivity condition. Specifically, we prove that a locally 2-connected, compact metric sp...... space M either contains an infinite complete graph or is surface like in the following sense: There exists a unique surface S such that S and M. contain the same finite graphs. Moreover, M is embeddable in S, that is, M is homeomorphic to a subset of S....

Proactive and coactive interference in age-related performance in a recognition-based operation span task.

Science.gov (United States)

Zeintl, Melanie; Kliegel, Matthias

2010-01-01

Generally, older adults perform worse than younger adults in complex working memory span tasks. So far, it is unclear which processes mainly contribute to age-related differences in working memory span. The aim of the present study was to investigate age effects and the roles of proactive and coactive interference in a recognition-based version of the operation span task. Younger and older adults performed standard versions and distracter versions of the operation span task. At retrieval, participants had to recognize target words in word lists containing targets as well as proactive and/or coactive interference-related lures. Results show that, overall, younger adults outperformed older adults in the recognition of target words. Furthermore, analyses of error types indicate that, while younger adults were only affected by simultaneously presented distracter words, older adults had difficulties with both proactive and coactive interference. Results suggest that age effects in complex span tasks may not be mainly due to retrieval deficits in old age. Copyright 2009 S. Karger AG, Basel.

How long will my mouse live? Machine learning approaches for prediction of mouse life span.

Science.gov (United States)

Swindell, William R; Harper, James M; Miller, Richard A

2008-09-01

Prediction of individual life span based on characteristics evaluated at middle-age represents a challenging objective for aging research. In this study, we used machine learning algorithms to construct models that predict life span in a stock of genetically heterogeneous mice. Life-span prediction accuracy of 22 algorithms was evaluated using a cross-validation approach, in which models were trained and tested with distinct subsets of data. Using a combination of body weight and T-cell subset measures evaluated before 2 years of age, we show that the life-span quartile to which an individual mouse belongs can be predicted with an accuracy of 35.3% (+/-0.10%). This result provides a new benchmark for the development of life-span-predictive models, but improvement can be expected through identification of new predictor variables and development of computational approaches. Future work in this direction can provide tools for aging research and will shed light on associations between phenotypic traits and longevity.

The Life Span of the BD-PND Bubble Detector

International Nuclear Information System (INIS)

Vanhavere, F.; Loos, M.; Thierens, H.

1999-01-01

BD-PND bubble detectors from Bubble Technology Industries (BTI) were used to conduct a study of the life span of these detectors. The manufacturer guarantees an optimum detector performance for three months after receipt. Nevertheless, it is important to know the evolution of their characteristics with time, also after those three months. On a standard set-up with a 252 Cf source the bubble detectors were irradiated until they reached the end of their life span. During this period, the evolution in sensitivity was monitored. The temperature compensating system seems to be the limiting factor with time for the use of the BTI bubble detectors. The change in temperature dependence with age was determined. The same parameters were also checked with several batches of detectors that were used in practice. (author)

Robustness Analysis of Big Span Glulam Truss Structure

DEFF Research Database (Denmark)

Rajčié, V.; čizmar, D.; Kirkegaard, Poul Henning

2010-01-01

(Eurocode 0 &1, Probabilistic model code etc.) Based on a project of big span glulam truss structure, build in Croatia few years ago, a probabilistic model is made with four failure elements. Reliability analysis of components is conducted and based on this a robustness analysis is preformed. It can...

Hard-Rock Stability Analysis for Span Design in Entry-Type Excavations with Learning Classifiers

Directory of Open Access Journals (Sweden)

Esperanza García-Gonzalo

2016-06-01

Full Text Available The mining industry relies heavily on empirical analysis for design and prediction. An empirical design method, called the critical span graph, was developed specifically for rock stability analysis in entry-type excavations, based on an extensive case-history database of cut and fill mining in Canada. This empirical span design chart plots the critical span against rock mass rating for the observed case histories and has been accepted by many mining operations for the initial span design of cut and fill stopes. Different types of analysis have been used to classify the observed cases into stable, potentially unstable and unstable groups. The main purpose of this paper is to present a new method for defining rock stability areas of the critical span graph, which applies machine learning classifiers (support vector machine and extreme learning machine. The results show a reasonable correlation with previous guidelines. These machine learning methods are good tools for developing empirical methods, since they make no assumptions about the regression function. With this software, it is easy to add new field observations to a previous database, improving prediction output with the addition of data that consider the local conditions for each mine.

Hard-Rock Stability Analysis for Span Design in Entry-Type Excavations with Learning Classifiers.

Science.gov (United States)

García-Gonzalo, Esperanza; Fernández-Muñiz, Zulima; García Nieto, Paulino José; Bernardo Sánchez, Antonio; Menéndez Fernández, Marta

2016-06-29

The mining industry relies heavily on empirical analysis for design and prediction. An empirical design method, called the critical span graph, was developed specifically for rock stability analysis in entry-type excavations, based on an extensive case-history database of cut and fill mining in Canada. This empirical span design chart plots the critical span against rock mass rating for the observed case histories and has been accepted by many mining operations for the initial span design of cut and fill stopes. Different types of analysis have been used to classify the observed cases into stable, potentially unstable and unstable groups. The main purpose of this paper is to present a new method for defining rock stability areas of the critical span graph, which applies machine learning classifiers (support vector machine and extreme learning machine). The results show a reasonable correlation with previous guidelines. These machine learning methods are good tools for developing empirical methods, since they make no assumptions about the regression function. With this software, it is easy to add new field observations to a previous database, improving prediction output with the addition of data that consider the local conditions for each mine.

The eye-voice span during reading aloud

Directory of Open Access Journals (Sweden)

Jochen eLaubrock

2015-09-01

Full Text Available Although eye movements during reading are modulated by cognitive processing demands, they also reflect visual sampling of the input, and possibly preparation of output for speech or the inner voice. By simultaneously recording eye movements and the voice during reading aloud, we obtained an output measure that constrains the length of time spent on cognitive processing. Here we investigate the dynamics of the eye-voice span (EVS, the distance between eye and voice. We show that the EVS is regulated immediately during fixation of a word by either increasing fixation duration or programming a regressive eye movement against the reading direction. EVS size at the beginning of a fixation was positively correlated with the likelihood of regressions and refixations. Regression probability was further increased if the EVS was still large at the end of a fixation: if adjustment of fixation duration did not sufficiently reduce the EVS during a fixation, then a regression rather than a refixation followed with high probability. We further show that the EVS can help understand cognitive influences on fixation duration during reading: in mixed model analyses, the EVS was a stronger predictor of fixation durations than either word frequency or word length. The EVS modulated the influence of several other predictors on single fixation durations. For example, word-N frequency effects were larger with a large EVS, especially when word N-1 frequency was low. Finally, a comparison of single fixation durations during oral and silent reading showed that reading is governed by similar principles in both reading modes, although EVS maintenance and articulatory processing also cause some differences. In summary, the eye-voice span is regulated by adjusting fixation duration and/or by programming a regressive eye movement when the eye-voice span gets too large. Overall, the EVS appears to be directly related to updating of the working memory buffer during reading.

Blocking Reduction of Span Restoration Requests in GMPLS Controlled WDM Optical Networks

DEFF Research Database (Denmark)

Buron, Jakob Due; Ruepp, Sarah Renée; Andriolli, N.

2006-01-01

The proposed label preference scheme reduces blocking of span restoration requests in GMPLS optical networks with limited wavelength conversion. By minimizing resource contention and conversion usage, it increases recovery percentage and reduces control plane load.......The proposed label preference scheme reduces blocking of span restoration requests in GMPLS optical networks with limited wavelength conversion. By minimizing resource contention and conversion usage, it increases recovery percentage and reduces control plane load....

Boundary Spanning in Global Software Development

DEFF Research Database (Denmark)

Søderberg, Anne-Marie; Romani, Laurence

imbalances of power, exacerbated in the case of an Indian vendor and a European client, need to be taken into account. The paper thus contributes with a more context sensitive understanding of inter-organizational boundary work. Taking the vendor perspective also leads to problematization of common...... of Indian IT vendor managers who are responsible for developing client relations and coordinating complex global development projects. The authors revise a framework of boundary spanning leadership practices to adapt it to an offshore outsourcing context. The empirical investigation highlights how...

Connecting DNA Origami Structures Using the Biotin-Streptavidin ...

African Journals Online (AJOL)

Abstract. This work made use of the strong interaction between biotin and streptavidin to connect designed DNA origami structures. The caDNAno software was used to design a 6 layer 3D origami cross-like structure. Selected DNA strands at the engineered attachment sites on the DNA origami structure were biotinylated.

Corruption, Political Connections, and Municipal Finance

OpenAIRE

Alexander W. Butler; Larry Fauver; Sandra Mortal

2009-01-01

We show that state corruption and political connections have strong effects on municipal bond sales and underwriting. Higher state corruption is associated with greater credit risk and higher bond yields. Corrupt states can eliminate the corruption yield penalty by purchasing credit enhancements. Underwriting fees were significantly higher during an era when underwriters made political contributions to win underwriting business. This pay-to-play underwriting fee premium exists only for negoti...

Effect of practice and span length on the dual-task coordination executive test

Directory of Open Access Journals (Sweden)

Sylwan R.P.

1999-01-01

Full Text Available The measure "mu", proposed as an index of the ability to coordinate concurrent box-crossing (BC and digit-span (DS tasks in the dual task (DT, should reflect the capacity of the executive component of the working memory system. We investigated the effect of practice in BC and of a change in the digit span on mu by adding previous practice trials in BC and diminishing, maintaining or increasing the digit sequence length. The mu behavior was evaluated throughout three trials of the test. Reported strategies in digit tasks were also analyzed. Subjects with diminished span showed the best performance in DT due to a stable performance in DS and BC in the single- and dual-task conditions. These subjects also showed a more stable performance throughout trials. Subjects with diminished span tended to employ effortless strategies, whereas subjects with increased span employed effort-requiring strategies and showed the lowest means of mu. Subjects with initial practice trials showed the best performance in BC and the most differentiated performance between the single- and dual-task conditions in BC. The correlation coefficient between the mu values obtained in the first and second trials was 0.814 for subjects with diminished span and practice trials in BC. It seems that the within-session practice in BC and the performance variability in DS affect the reliability of the index mu. To control these factors we propose the introduction of previous practice trials in BC and a modification of the current method to determine the digit sequence length. This proposal should contribute to the development of a more reliable method to evaluate the executive capacity of coordination in the dual-task paradigm.

E-commercspan>e in the banking sector

NARCIS (Netherlands)

Stroeken, J.H.M.; Munck, S.G.E. de; Hawkins, R.

2001-01-01

Het doel van de studie is het verschaffen van inzicht in de effecten van e-commercspan>e in de Nederlandse banksector. Elektronische transactie omgevingen als zodanig zijn niet nieuw voor banken, en financiële dienstverlening heeft altijd al te maken gehad met intermediëring door elektronische netwerken.

Damage detection in multi-span beams based on the analysis of frequency changes

International Nuclear Information System (INIS)

Gillich, G R; Ntakpe, J L; Praisach, Z I; Mimis, M C; Abdel Wahab, M

2017-01-01

Crack identification in multi-span beams is performed to determine whether the structure is healthy or not. Among all crack identification methods, these based on measured natural frequency changes present the advantage of simplicity and easy to use in practical engineering. To accurately identify the cracks characteristics for multi-span beam structure, a mathematical model is established, which can predict frequency changes for any boundary conditions, the intermediate supports being hinges. This relation is based on the modal strain energy concept. Since frequency changes are relative small, to obtain natural frequencies with high resolution, a signal processing algorithm based on superposing of numerous spectra is also proposed, which overcomes the disadvantage of Fast Fourier Transform in the aspect of frequency resolution. Based on above-mentioned mathematical model and signal processing algorithm, the method of identifying cracks on multi-span beams is presented. To verify the accuracy of this identification method, experimental examples are conducted on a two-span structure. The results demonstrate that the method proposed in this paper can accurately identify the crack position and depth. (paper)

Sensitivity of marine protected area network connectivity to atmospheric variability.

Science.gov (United States)

Fox, Alan D; Henry, Lea-Anne; Corne, David W; Roberts, J Murray

2016-11-01

International efforts are underway to establish well-connected systems of marine protected areas (MPAs) covering at least 10% of the ocean by 2020. But the nature and dynamics of ocean ecosystem connectivity are poorly understood, with unresolved effects of climate variability. We used 40-year runs of a particle tracking model to examine the sensitivity of an MPA network for habitat-forming cold-water corals in the northeast Atlantic to changes in larval dispersal driven by atmospheric cycles and larval behaviour. Trajectories of Lophelia pertusa larvae were strongly correlated to the North Atlantic Oscillation (NAO), the dominant pattern of interannual atmospheric circulation variability over the northeast Atlantic. Variability in trajectories significantly altered network connectivity and source-sink dynamics, with positive phase NAO conditions producing a well-connected but asymmetrical network connected from west to east. Negative phase NAO produced reduced connectivity, but notably some larvae tracked westward-flowing currents towards coral populations on the mid-Atlantic ridge. Graph theoretical metrics demonstrate critical roles played by seamounts and offshore banks in larval supply and maintaining connectivity across the network. Larval longevity and behaviour mediated dispersal and connectivity, with shorter lived and passive larvae associated with reduced connectivity. We conclude that the existing MPA network is vulnerable to atmospheric-driven changes in ocean circulation.

Post-tensioning and splicing of precast/prestressed bridge beams to extend spans

Science.gov (United States)

Collett, Brandon S.; Saliba, Joseph E.

2002-06-01

This paper explores the status and techniques of post-tensioning and splicing precast concrete I-beams in bridge applications. It will look at the current practices that have been used in the United States and comment on the advantages of these techniques. Representative projects are presented to demonstrate the application and success of specific methods used. To demonstrate the benefits of using post-tensioning and splicing to extend spans, multiple analysis of simple span post-tensioned I-beams were performed varying such characteristics as beam spacing, beam sections, beam depth and concrete strength. Tables were then developed to compare the maximum span length of a prestressed I-beam versus a one segment or a spliced three segment post-tensioned I-beam. The lateral stability of the beam during fabrication, transportation and erection is also examined and discussed. These tables are intended to aid designers and owners in preliminary project studies to determine if post-tensioning can be beneficial to their situation. AASHTO Standard Specifications(2) will be used as basic guidelines and specifications. In many cases, post-tensioning was found to extend the maximum span length of a typical 72-inch precast I-beam more than 40 feet over conventional prestress.

Flexible modulation of network connectivity related to cognition in Alzheimer’s disease

Science.gov (United States)

McLaren, Donald G.; Sperling, Reisa A.; Atria, Alireza

2014-01-01

Functional neuroimaging tools, such as fMRI methods, may elucidate the neural correlates of clinical, behavioral, and cognitive performance. Most functional imaging studies focus on regional task-related activity or resting state connectivity rather than how changes in functional connectivity across conditions and tasks are related to cognitive and behavioral performance. To investigate the promise of characterizing context-dependent connectivity-behavior relationships, this study applies the method of generalized psychophysiological interactions (gPPI) to assess the patterns of associative-memory-related fMRI hippocampal functional connectivity in Alzheimer’s disease (AD) associated with performance on memory and other cognitively demanding neuropsychological tests and clinical measures. Twenty-four subjects with mild AD dementia (ages 54–82, nine females) participated in a face-name paired-associate encoding memory study. Generalized PPI analysis was used to estimate the connectivity between the hippocampus and the whole brain during encoding. The difference in hippocampal-whole brain connectivity between encoding novel and repeated face-name pairs was used in multiple-regression analyses as an independent predictor for 10 behavioral, neuropsychological and clinical tests. The analysis revealed connectivity-behavior relationships that were distributed, dynamically overlapping, and task-specific within and across intrinsic networks; hippocampal-whole brain connectivity-behavior relationships were not isolated to single networks, but spanned multiple brain networks. Importantly, these spatially distributed performance patterns were unique for each measure. In general, out-of-network behavioral associations with encoding novel greater than repeated face-name pairs hippocampal-connectivity were observed in the default-mode network, while correlations with encoding repeated greater than novel face-name pairs hippocampal-connectivity were observed in the executive

Increased insula-putamen connectivity in X-linked dystonia-parkinsonism

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Anne J. Blood

2018-01-01

Full Text Available Preliminary evidence from postmortem studies of X-linked dystonia-parkinsonism (XDP suggests tissue loss may occur first and/or most severely in the striatal striosome compartment, followed later by cell loss in the matrix compartment. However, little is known about how this relates to pathogenesis and pathophysiology. While MRI cannot visualize these striatal compartments directly in humans, differences in relative gradients of afferent cortical connectivity across compartments (weighted toward paralimbic versus sensorimotor cortex, respectively can be used to infer potential selective loss in vivo. In the current study we evaluated relative connectivity of paralimbic versus sensorimotor cortex with the caudate and putamen in 17 individuals with XDP and 17 matched controls. Although caudate and putamen volumes were reduced in XDP, there were no significant reductions in either “matrix-weighted”, or “striosome-weighted” connectivity. In fact, paralimbic connectivity with the putamen was elevated, rather than reduced, in XDP. This was driven most strongly by elevated putamen connectivity with the anterior insula. There was no relationship of these findings to disease duration or striatal volume, suggesting insula and/or paralimbic connectivity in XDP may develop abnormally and/or increase in the years before symptom onset.

STUDY THE CHARACTERISTICS OF SMALL AND VERY SMALL SPAN WINGS, USED ON SHIPS

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Beazit ALI

2011-07-01

Full Text Available This scientific work presents the way in which the small, and very small span wings can be obtainedstarting from the great span wings and using the two scales of the similarity theory. Basing on two scales modelit can transcribe from model at nature the coefficients x c , y c and lengthening λ of Gottingen - 612 profile.

The structural role of weak and strong links in a financial market network

Science.gov (United States)

Garas, A.; Argyrakis, P.; Havlin, S.

2008-05-01

We investigate the properties of correlation based networks originating from economic complex systems, such as the network of stocks traded at the New York Stock Exchange (NYSE). The weaker links (low correlation) of the system are found to contribute to the overall connectivity of the network significantly more than the strong links (high correlation). We find that nodes connected through strong links form well defined communities. These communities are clustered together in more complex ways compared to the widely used classification according to the economic activity. We find that some companies, such as General Electric (GE), Coca Cola (KO), and others, can be involved in different communities. The communities are found to be quite stable over time. Similar results were obtained by investigating markets completely different in size and properties, such as the Athens Stock Exchange (ASE). The present method may be also useful for other networks generated through correlations.

Seismic Performances of Replaceable Steel Connection with Low Yield Point Metal

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Haoxiang He

2015-01-01

Full Text Available Compared with the traditional steel rigid connection, the beam-column connections with weakened beam end have better ductility, but the local buckling in the weakened zone and the overall lateral deformation may occur in strong earthquake. The replaceable steel connection with low yield point metal is proposed based on the concept of earthquake resilient structure. In this connection, the weakened parts in the flange slab and web plate are filled with low yield point metal, and the metal firstly yields and dissipates energy sufficiently in earthquake; hence, the main parts are intact and the yield point metal can be replaced. The seismic performances of the three types of connections which include traditional connection, beam end weakened connection, and replaceable connection with low yield point steel under low cycle reciprocating load are studied. In addition, the energy dissipation capacity and damage characteristics of different connections are compared. The multiscale finite element models for the steel frames with different connections are analyzed by time-history method; both the computational efficiency and the accuracy are assured. The analysis results approve that the replaceable connection can confine the major damage in the replacement material and have better energy dissipation ability, safety reserves, and resilient ability.

Symmetric Electrode Spanning Narrows the Excitation Patterns of Partial Tripolar Stimuli in Cochlear Implants.

Science.gov (United States)

Luo, Xin; Wu, Ching-Chih

2016-12-01

In cochlear implants (CIs), standard partial tripolar (pTP) mode reduces current spread by returning a fraction of the current to two adjacent flanking electrodes within the cochlea. Symmetric electrode spanning (i.e., separating both the apical and basal return electrodes from the main electrode by one electrode) has been shown to increase the pitch of pTP stimuli, when the ratio of intracochlear return current was fixed. To explain the pitch increase caused by symmetric spanning in pTP mode, this study measured the electrical potentials of both standard and symmetrically spanned pTP stimuli on a main electrode EL8 in five CI ears using electrical field imaging (EFI). In addition, the spatial profiles of evoked compound action potentials (ECAP) and the psychophysical forward masking (PFM) patterns were also measured for both stimuli. The EFI, ECAP, and PFM patterns of a given stimulus differed in shape details, reflecting the different levels of auditory processing and different ratios of intracochlear return current across the measurement methods. Compared to the standard pTP stimuli, the symmetrically spanned pTP stimuli significantly reduced the areas under the curves of the normalized EFI and PFM patterns, without shifting the pattern peaks and centroids (both around EL8). The more focused excitation patterns with symmetric spanning may have caused the previously reported pitch increase, due to an interaction between pitch and timbre perception. Being able to reduce the spread of excitation, pTP mode symmetric spanning is a promising stimulation strategy that may further increase spectral resolution and frequency selectivity with CIs.

DYNAMIC BEHAVIOR OF TWO-SPAN CONTINUOUS CONCRETE BRIDGES UNDER MOVING OF HIGH-SPEED TRAINS

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O. H. Marinichenko

2017-10-01

Full Text Available Purpose. The scientific work provides a comparison of the results of the movement of a high-speed passenger train across the bridge, obtained as a result of finite element modeling in the SAP2000 software package, and real tests of a double-span concrete railway bridge. Analysis of the rigid characteristics of flying structures. Methodology.The numerical method presented in this study shows valid results concerning the dynamic analysis of the behavior of bridges in conditions of high-speed train traffic. The factors influencing the dynamic behavior of bridges under moving loads, the influence of design parameters and rolling stock, as well as the interaction of the train and spans are determined. The system was used in the form of moving concentrated forces simulating the axes of the train. Findings. Maximum movements and accelerations were obtained as a result of the dynamic calculation for different speeds of the train and compared with practical tests. The correctness of the model of a span structure with regard to continuous ferroconcrete spans was verified. Originality. Within the framework of the work, the latest test results were used, including those with speeds calculated on the prospect of rail passenger traffic. For these tests, a model of a span structure was developed. Practical value. The results of the research can be used to plan the introduction of high-speed train traffic on existing and planned flying structures of reinforced concrete bridges. An approach to the design of span structures that will be effective when passing high-speed passenger trains is implemented.

Study on unitized inverter with photovoltaic grid-connected and stand-alone functions

Energy Technology Data Exchange (ETDEWEB)

Wang, Haining; Su, Jianhui; Ding, Ming [Hefei University of Technology, Hefei (China)

2008-07-01

The main circuit and algorithm of unitized single phase inverter are presented, in which photovoltaic (PV) grid-connected algorithm, independency sine inverter algorithm and storage battery charge administer are all integrated basing on DSP (Digital Signal Processor). The control system identifies utility failure initiatively and then switches to independency power supply automatically. The methods of charging battery are multiform. Basing on material term to use utility or solar array to charge can optimize charge efficiency, assure the capacitance of battery and prolong life-span of battery. In addition, some results are offered basing on the prototype of a 2.5kW single phase inverter. (orig.)

USE OF MEMBRANE EMULSION SPAN 80 AND TOPO IN URANIUM EXTRACTION AND STRIPPING

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Kris Tri Basuki

2017-01-01

Full Text Available ABSTRACT USE OF MEMBRANE EMULSION SPAN 80 AND TOPO IN URANIUM EXTRACTION AND STRIPPING. Membrane emulsion span 80 and TOPO used in uranium extraction and stripping has been done. The extraction was carried outby emulsion membrane H3PO4 in TOPO-Kerosene. The feed or external aqueous phase was uranium in  HNO3. The emulgator span-80 was used to obtain a stable emulsion membrane system. The influence factors were percentage of TOPO-Kerosene, time extraction,  molarity of external aqueous phase and  molarity of internal aqueous. After the emulsion membrane was formed, the extractionand stripping process was performed. The ratio volume feed : volume membrane phase equal to 1 : 1 and volume of 5 % TOPO-Kerosene : Volume 3 M H3PO4 equal 1 : 1 were used. The relative good yield were obtained at concentration of TOPO in Kerosene and 3 M H3PO4 was 5 %, molarity of internal aqueous phase equal to 1 M, molarity of external aqueous phase 3 M H3PO4 and time extraction equalto 10 minutes with the speed of emulsification was 8000 rpm. At this condition the extraction efficiency of uranium obtained was 97.8 %, the stripping efficiency 52.56 %, and the total efficiency was 53.80 %. Keywords: membrane emulsion, extraction, stripping, span 80, kerosene, uranium. ABSTRAK PENGGUNAAN MEMBRAN EMULSI SPAN 80 DAN TOPO UNTUK EKSTRASI DAN STRIPPING URANIUM. Telah dilakukan penelitian membran emulsi span 80 dan TOPO yang digunakan untuk ekstraksi uranium. Extraksi dengan membran emulsi H3PO4 dalam TOPO-Kerosen. Larutan umpan untuk fasa air eksternal adalah uranium dalam asam nitrat. Untuk memperoleh sistem emulsi yang stabil dipakai emulgator Span 80. Parameter yang berpengaruh adalah persen TOPO-Kerosene, molaritas fasa air internal H3PO4, molaritas fasa air eksternal HNO3 dan waktu ekstraksi. Setelah diperoleh membran emulsi, kemudian dilakukan proses ekstraksi dan stripping, dengan rasio volume umpan : volume membran sebesar 1 : 1; volume 5% TOPO-Kerose : volume 3M

A Resting-State Brain Functional Network Study in MDD Based on Minimum Spanning Tree Analysis and the Hierarchical Clustering

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Xiaowei Li

2017-01-01

Full Text Available A large number of studies demonstrated that major depressive disorder (MDD is characterized by the alterations in brain functional connections which is also identifiable during the brain’s “resting-state.” But, in the present study, the approach of constructing functional connectivity is often biased by the choice of the threshold. Besides, more attention was paid to the number and length of links in brain networks, and the clustering partitioning of nodes was unclear. Therefore, minimum spanning tree (MST analysis and the hierarchical clustering were first used for the depression disease in this study. Resting-state electroencephalogram (EEG sources were assessed from 15 healthy and 23 major depressive subjects. Then the coherence, MST, and the hierarchical clustering were obtained. In the theta band, coherence analysis showed that the EEG coherence of the MDD patients was significantly higher than that of the healthy controls especially in the left temporal region. The MST results indicated the higher leaf fraction in the depressed group. Compared with the normal group, the major depressive patients lost clustering in frontal regions. Our findings suggested that there was a stronger brain interaction in the MDD group and a left-right functional imbalance in the frontal regions for MDD controls.

Several Families of Sequences with Low Correlation and Large Linear Span

Science.gov (United States)

Zeng, Fanxin; Zhang, Zhenyu

In DS-CDMA systems and DS-UWB radios, low correlation of spreading sequences can greatly help to minimize multiple access interference (MAI) and large linear span of spreading sequences can reduce their predictability. In this letter, new sequence sets with low correlation and large linear span are proposed. Based on the construction Trm1[Trnm(αbt+γiαdt)]r for generating p-ary sequences of period pn-1, where n=2m, d=upm±v, b=u±v, γi∈GF(pn), and p is an arbitrary prime number, several methods to choose the parameter d are provided. The obtained sequences with family size pn are of four-valued, five-valued, six-valued or seven-valued correlation and the maximum nontrivial correlation value is (u+v-1)pm-1. The simulation by a computer shows that the linear span of the new sequences is larger than that of the sequences with Niho-type and Welch-type decimations, and similar to that of [10].

Analysis of the effectiveness of various cross-sections in large-span post-tensioned ceilings

Science.gov (United States)

Bednarz, K.

2018-03-01

The correct construction of large span, slim post-tensioned concrete slabs is conditioned by an appropriate cross-section selection. It is generally accepted that the thinnest slab can be constructed using the full cross-section as the largest compression stress storage. However, completely different cross-sections may help to overcome large spans. The paper presents the results of the computational analysis of several types of cross-sections (full, with internal relieving inserts and ribbed) in the application to a post-tensioned slab with a span of 15.0m. Based on the results presented, appropriate conclusions were drawn.

Exploration of malingering indices in the Wechsler Adult Intelligence Scale-Fourth Edition Digit Span subtest.

Science.gov (United States)

Reese, Caitlin S; Suhr, Julie A; Riddle, Tara L

2012-03-01

Prior research shows that Digit Span is a useful embedded measure of malingering. However, the Wechsler Adult Intelligence Scale-IV (Wechsler, 2008) altered Digit Span in meaningful ways, necessitating another look at Digit Span as an embedded measure of malingering. Using a simulated malingerer design, we examined the predictive accuracy of existing Digit Span validity indices and explored whether patterns of performance utilizing the new version would provide additional evidence for malingering. Undergraduates with a history of mild head injury performed with best effort or simulated impaired cognition and were also compared with a large sample of non-head-injured controls. Previously established cutoffs for the age-corrected scaled score and Reliable Digit Span (RDS) performed similarly in the present samples. Patterns of RDS length using all three subscales of the new scale were different in malingerers when compared with both head-injured and non-head-injured controls. Two potential alternative RDS scores were introduced, which showed better sensitivity than the traditional RDS, while retaining specificity to malingering.

Structural covariance networks across the life span, from 6 to 94 years of age.

Science.gov (United States)

DuPre, Elizabeth; Spreng, R Nathan

2017-10-01

Structural covariance examines covariation of gray matter morphology between brain regions and across individuals. Despite significant interest in the influence of age on structural covariance patterns, no study to date has provided a complete life span perspective-bridging childhood with early, middle, and late adulthood-on the development of structural covariance networks. Here, we investigate the life span trajectories of structural covariance in six canonical neurocognitive networks: default, dorsal attention, frontoparietal control, somatomotor, ventral attention, and visual. By combining data from five open-access data sources, we examine the structural covariance trajectories of these networks from 6 to 94 years of age in a sample of 1,580 participants. Using partial least squares, we show that structural covariance patterns across the life span exhibit two significant, age-dependent trends. The first trend is a stable pattern whose integrity declines over the life span. The second trend is an inverted-U that differentiates young adulthood from other age groups. Hub regions, including posterior cingulate cortex and anterior insula, appear particularly influential in the expression of this second age-dependent trend. Overall, our results suggest that structural covariance provides a reliable definition of neurocognitive networks across the life span and reveal both shared and network-specific trajectories.

Effects of local and global network connectivity on synergistic epidemics

Science.gov (United States)

Broder-Rodgers, David; Pérez-Reche, Francisco J.; Taraskin, Sergei N.

2015-12-01

Epidemics in networks can be affected by cooperation in transmission of infection and also connectivity between nodes. An interplay between these two properties and their influence on epidemic spread are addressed in the paper. A particular type of cooperative effects (called synergy effects) is considered, where the transmission rate between a pair of nodes depends on the number of infected neighbors. The connectivity effects are studied by constructing networks of different topology, starting with lattices with only local connectivity and then with networks that have both local and global connectivity obtained by random bond-rewiring to nodes within a certain distance. The susceptible-infected-removed epidemics were found to exhibit several interesting effects: (i) for epidemics with strong constructive synergy spreading in networks with high local connectivity, the bond rewiring has a negative role in epidemic spread, i.e., it reduces invasion probability; (ii) in contrast, for epidemics with destructive or weak constructive synergy spreading on networks of arbitrary local connectivity, rewiring helps epidemics to spread; (iii) and, finally, rewiring always enhances the spread of epidemics, independent of synergy, if the local connectivity is low.

The importance of adult life-span perspective in explaining variations in political ideology.

Science.gov (United States)

Sedek, Grzegorz; Kossowska, Malgorzata; Rydzewska, Klara

2014-06-01

As a comment on Hibbing et al.'s paper, we discuss the evolution of political and social views from more liberal to more conservative over the span of adulthood. We show that Hibbing et al.'s theoretical model creates a false prediction from this developmental perspective, as increased conservatism in the adult life-span trajectory is accompanied by the avoidance of negative bias.

ETS-4 is a transcriptional regulator of life span in Caenorhabditis elegans.

Directory of Open Access Journals (Sweden)

Bargavi Thyagarajan

2010-09-01

Full Text Available Aging is a complex phenotype responsive to a plethora of environmental inputs; yet only a limited number of transcriptional regulators are known to influence life span. How the downstream expression programs mediated by these factors (or others are coordinated into common or distinct set of aging effectors is an addressable question in model organisms, such as C. elegans. Here, we establish the transcription factor ETS-4, an ortholog of vertebrate SPDEF, as a longevity determinant. Adult worms with ets-4 mutations had a significant extension of mean life span. Restoring ETS-4 activity in the intestine, but not neurons, of ets-4 mutant worms rescued life span to wild-type levels. Using RNAi, we demonstrated that ets-4 is required post-developmentally to regulate adult life span; thus uncoupling the role of ETS-4 in aging from potential functions in worm intestinal development. Seventy ETS-4-regulated genes, identified by gene expression profiling of two distinct ets-4 alleles and analyzed by bioinformatics, were enriched for known longevity effectors that function in lipid transport, lipid metabolism, and innate immunity. Putative target genes were enriched for ones that change expression during normal aging, the majority of which are controlled by the GATA factors. Also, some ETS-4-regulated genes function downstream of the FOXO factor, DAF-16 and the insulin/IGF-1 signaling pathway. However, epistasis and phenotypic analyses indicate that ets-4 functioned in parallel to the insulin/IGF-1 receptor, daf-2 and akt-1/2 kinases. Furthermore, ets-4 required daf-16 to modulate aging, suggesting overlap in function at the level of common targets that affect life span. In conclusion, ETS-4 is a new transcriptional regulator of aging, which shares transcriptional targets with GATA and FOXO factors, suggesting that overlapping pathways direct common sets of lifespan-related genes.

Node-based measures of connectivity in genetic networks.

Science.gov (United States)

Koen, Erin L; Bowman, Jeff; Wilson, Paul J

2016-01-01

At-site environmental conditions can have strong influences on genetic connectivity, and in particular on the immigration and settlement phases of dispersal. However, at-site processes are rarely explored in landscape genetic analyses. Networks can facilitate the study of at-site processes, where network nodes are used to model site-level effects. We used simulated genetic networks to compare and contrast the performance of 7 node-based (as opposed to edge-based) genetic connectivity metrics. We simulated increasing node connectivity by varying migration in two ways: we increased the number of migrants moving between a focal node and a set number of recipient nodes, and we increased the number of recipient nodes receiving a set number of migrants. We found that two metrics in particular, the average edge weight and the average inverse edge weight, varied linearly with simulated connectivity. Conversely, node degree was not a good measure of connectivity. We demonstrated the use of average inverse edge weight to describe the influence of at-site habitat characteristics on genetic connectivity of 653 American martens (Martes americana) in Ontario, Canada. We found that highly connected nodes had high habitat quality for marten (deep snow and high proportions of coniferous and mature forest) and were farther from the range edge. We recommend the use of node-based genetic connectivity metrics, in particular, average edge weight or average inverse edge weight, to model the influences of at-site habitat conditions on the immigration and settlement phases of dispersal. © 2015 John Wiley & Sons Ltd.

Truth-telling and Nash equilibria in minimum cost spanning tree models

DEFF Research Database (Denmark)

Hougaard, Jens Leth; Tvede, Mich

2012-01-01

In this paper we consider the minimum cost spanning tree model. We assume that a central planner aims at implementing a minimum cost spanning tree not knowing the true link costs. The central planner sets up a game where agents announce link costs, a tree is chosen and costs are allocated according...... to the rules of the game. We characterize ways of allocating costs such that true announcements constitute Nash equilibria both in case of full and incomplete information. In particular, we find that the Shapley rule based on the irreducible cost matrix is consistent with truthful announcements while a series...

Physical Activity Throughout the Adult Life Span and Domain-Specific Cognitive Function in Old Age: A Systematic Review of Cross-Sectional and Longitudinal Data.

Science.gov (United States)

Engeroff, Tobias; Ingmann, Tobias; Banzer, Winfried

2018-06-01

A growing body of literature suggests that physical activity might alleviate the age-related neurodegeneration and decline of cognitive function. However, most of this evidence is based on data investigating the association of exercise interventions or current physical activity behavior with cognitive function in elderly subjects. We performed a systematic review and hypothesize that physical activity during the adult life span is connected with maintained domain-specific cognitive functions during late adulthood defined as age 60+ years. We performed a systematic literature search up to November 2017 in PubMed, Web of Science, and Google Scholar without language limitations for studies analyzing the association of leisure physical activity during the adult life span (age 18+ years) and domain-specific cognitive functions in older adults (age 60+ years). The literature review yielded 14,294 articles and after applying inclusion and exclusion criteria, nine cross-sectional and 14 longitudinal studies were included. Moderate- and vigorous-intensity leisure physical activity was associated with global cognitive function and specific cognitive domains including executive functions and memory but not attention or working memory. Most studies assessed mid- to late-adulthood physical activity, thus information concerning the influence of young adult life-span physical activity is currently lacking. Observational evidence that moderate- and vigorous-intensity leisure physical activity is beneficially associated with maintained cognitive functions during old age is accumulating. Further studies are necessary to confirm a causal link by assessing objective physical activity data and the decline of cognitive functions at multiple time points during old age.

Strong-Field Physics with Mid-IR Fields

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Benjamin Wolter

2015-06-01

Full Text Available Strong-field physics is currently experiencing a shift towards the use of mid-IR driving wavelengths. This is because they permit conducting experiments unambiguously in the quasistatic regime and enable exploiting the effects related to ponderomotive scaling of electron recollisions. Initial measurements taken in the mid-IR immediately led to a deeper understanding of photoionization and allowed a discrimination among different theoretical models. Ponderomotive scaling of rescattering has enabled new avenues towards time-resolved probing of molecular structure. Essential for this paradigm shift was the convergence of two experimental tools: (1 intense mid-IR sources that can create high-energy photons and electrons while operating within the quasistatic regime and (2 detection systems that can detect the generated high-energy particles and image the entire momentum space of the interaction in full coincidence. Here, we present a unique combination of these two essential ingredients, namely, a 160-kHz mid-IR source and a reaction microscope detection system, to present an experimental methodology that provides an unprecedented three-dimensional view of strong-field interactions. The system is capable of generating and detecting electron energies that span a 6 order of magnitude dynamic range. We demonstrate the versatility of the system by investigating electron recollisions, the core process that drives strong-field phenomena, at both low (meV and high (hundreds of eV energies. The low-energy region is used to investigate recently discovered low-energy structures, while the high-energy electrons are used to probe atomic structure via laser-induced electron diffraction. Moreover, we present, for the first time, the correlated momentum distribution of electrons from nonsequential double ionization driven by mid-IR pulses.

A closed solution for the collapse load of pressurized pipelines in free spans

Energy Technology Data Exchange (ETDEWEB)

Bezerra, Luciano M. [Brasilia Univ., DF (Brazil). Dept. de Engenharia Civil; Murray, David W.; Xuejun Song [University of Alberta (Canada). Civil Engineering Dept.

2005-07-01

Submarine pipelines for oil exploitation, generally, are under internal pressure and compressive thermal loading. Due to rough see-bottom terrains, these pipelines may be supported only intermittently and span freely. The collapse of such pipelines may produce oil leakage to the environment. A common engineering practice for the determination of the collapse load of such pipelines is the use of finite element modeling. This paper presents an analytical method for the determination of the collapse load of pressurized pipelines extended over free spans. The formulation also takes into account the internal pressure and initial imperfection, generally present in these pipelines. Collapse load is determined from a deduced transcendental equation. Results of the presented formulation are compared with sophisticated finite element analyses. While sophisticated finite element analysis requires hours of computer processing, the present formulation takes practically no time to assess a good approximation for the collapse load of pressurized free span pipelines under compression. The present paper is not intended to substitute the more precise finite element analyses but to provide an easier, faster, and practical way to determine a first approximation of the collapse load of pressurized free span pipelines. (author)

Using graph approach for managing connectivity in integrative landscape modelling

Science.gov (United States)

Rabotin, Michael; Fabre, Jean-Christophe; Libres, Aline; Lagacherie, Philippe; Crevoisier, David; Moussa, Roger

2013-04-01

In cultivated landscapes, a lot of landscape elements such as field boundaries, ditches or banks strongly impact water flows, mass and energy fluxes. At the watershed scale, these impacts are strongly conditionned by the connectivity of these landscape elements. An accurate representation of these elements and of their complex spatial arrangements is therefore of great importance for modelling and predicting these impacts.We developped in the framework of the OpenFLUID platform (Software Environment for Modelling Fluxes in Landscapes) a digital landscape representation that takes into account the spatial variabilities and connectivities of diverse landscape elements through the application of the graph theory concepts. The proposed landscape representation consider spatial units connected together to represent the flux exchanges or any other information exchanges. Each spatial unit of the landscape is represented as a node of a graph and relations between units as graph connections. The connections are of two types - parent-child connection and up/downstream connection - which allows OpenFLUID to handle hierarchical graphs. Connections can also carry informations and graph evolution during simulation is possible (connections or elements modifications). This graph approach allows a better genericity on landscape representation, a management of complex connections and facilitate development of new landscape representation algorithms. Graph management is fully operational in OpenFLUID for developers or modelers ; and several graph tools are available such as graph traversal algorithms or graph displays. Graph representation can be managed i) manually by the user (for example in simple catchments) through XML-based files in easily editable and readable format or ii) by using methods of the OpenFLUID-landr library which is an OpenFLUID library relying on common open-source spatial libraries (ogr vector, geos topologic vector and gdal raster libraries). Open

C. elegans VANG-1 modulates life span via insulin/IGF-1-like signaling.

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Sebastian J Honnen

Full Text Available The planar cell polarity (PCP pathway is highly conserved from Drosophila to humans and a PCP-like pathway has recently been described in the nematode Caenorhabditis elegans. The developmental function of this pathway is to coordinate the orientation of cells or structures within the plane of an epithelium or to organize cell-cell intercalation required for correct morphogenesis. Here, we describe a novel role of VANG-1, the only C. elegans ortholog of the conserved PCP component Strabismus/Van Gogh. We show that two alleles of vang-1 and depletion of the protein by RNAi cause an increase of mean life span up to 40%. Consistent with the longevity phenotype vang-1 animals also show enhanced resistance to thermal- and oxidative stress and decreased lipofuscin accumulation. In addition, vang-1 mutants show defects like reduced brood size, decreased ovulation rate and prolonged reproductive span, which are also related to gerontogenes. The germline, but not the intestine or neurons, seems to be the primary site of vang-1 function. Life span extension in vang-1 mutants depends on the insulin/IGF-1-like receptor DAF-2 and DAF-16/FoxO transcription factor. RNAi against the phase II detoxification transcription factor SKN-1/Nrf2 also reduced vang-1 life span that might be explained by gradual inhibition of insulin/IGF-1-like signaling in vang-1. This is the first time that a key player of the PCP pathway is shown to be involved in the insulin/IGF-1-like signaling dependent modulation of life span in C. elegans.

Heat losses through pipe connections in hot water stores

DEFF Research Database (Denmark)

Andersen, Elsa; Fan, Jianhua; Furbo, Simon

2007-01-01

The heat loss from pipe connections at the top of hot water storage tanks with and without a heat trap is investigated theoretically and compared to similar experimental investigations. Computational Fluid Dynamics (CFD) is used for the theoretical analysis. The investigations show that the heat...... loss from an ideally insulated pipe connected to the top of a hot water tank is mainly due to a natural convection flow in the pipe, that the heat loss coefficient of pipes connected to the top of a hot water tank is high, and that a heat trap can reduce the heat loss coefficient significantly. Further......, calculations show that the yearly thermal performance of solar domestic hot water systems is strongly reduced if the hot water tank has a thermal bridge located at the top of the tank....

Impact Coefficient Analysis of Long-Span Railway Cable-Stayed Bridge Based on Coupled Vehicle-Bridge Vibration

Directory of Open Access Journals (Sweden)

Yongle Li

2015-01-01

Full Text Available Compared with medium and small span bridges, very limited attention has been paid on the research of the impact coefficient of long-span railway bridges. To estimate the impact effects of long-span railway bridges subjected to moving vehicles, a real long-span railway cable-stayed bridge is regarded as the research object in this study, and a coupled model of vehicle-bridge system is established. The track irregularities are taken as the system excitation and the dynamic responses of the vehicle-bridge system are calculated. The impact effects on main girder, stayed cable, bearings, and bridge tower are discussed at various vehicle speeds. The results show that different components of the long-span railway cable-stayed bridge have different impact coefficients. Even for each part, the impact coefficient is also different at different local positions. It reveals that the impact coefficients in the actual situation may have significant differences with the related code clauses in the present design codes.

Working Memory Capacity and Fluid Abilities: Examining the Correlation between Operation Span and Raven

Science.gov (United States)

Unsworth, N.; Engle, R.W.

2005-01-01

The correlation between a measure of working memory capacity (WMC) (Operation Span) and a measure of fluid abilities (Raven Advanced Progressive Matrices) was examined. Specifically, performance on Raven problems was decomposed by difficulty, memory load, and rule type. The results suggest that the relation between Operation Span and Raven is…

Working Memory Deficits in Children with Reading Difficulties: Memory Span and Dual Task Coordination

Science.gov (United States)

Wang, Shinmin; Gathercole, Susan E.

2013-01-01

The current study investigated the cause of the reported problems in working memory in children with reading difficulties. Verbal and visuospatial simple and complex span tasks, and digit span and reaction times tasks performed singly and in combination, were administered to 46 children with single word reading difficulties and 45 typically…

Heritability of life span in the Old Order Amish.

Science.gov (United States)

Mitchell, B D; Hsueh, W C; King, T M; Pollin, T I; Sorkin, J; Agarwala, R; Schäffer, A A; Shuldiner, A R

2001-09-01

Although a familial contribution to human longevity is recognized, the nature of this contribution is largely unknown. We have examined the familial contribution to life span in the Old Order Amish (OOA) population of Lancaster County, Pennsylvania. Analyses were conducted on 1,655 individuals, representing all those born prior to 1890 and appearing in the most widely available genealogy, surviving until at least age 30 years, and with known date of death. Mean age at death (+/-SD) in this population was 70.7 +/- 15.6 years, and this did not change appreciably over time. Parental and offspring ages at death were significantly correlated, as were ages of death among siblings. Offspring longevity was correlated with longevity of both parents, and in more or less additive fashion. For example, mean offspring age at death was 69.4 +/- 15.3 years in individuals for whom both parents died before the age of 75 years (n = 280) and increased to 73.5 +/- 16.0 years in individuals for whom neither parent died before the age of 75 years (n = 311). These differences were highly significant (P = 0.006). We estimated heritability of life span to be 25% +/- 5%, suggesting that the additive effects of genes account for one quarter of the total variability in life span in the OOA. We conclude that longevity is moderately heritable in the OOA, that the genetic effects are additive, and that genetic influences on longevity are likely to be expressed across a broad range of ages. Published 2001 Wiley-Liss, Inc.

Asymmetry in auditory and spatial attention span in normal elderly genetically at risk for Alzheimer's disease.

Science.gov (United States)

Jacobson, Mark W; Delis, Dean C; Bondi, Mark W; Salmon, David P

2005-02-01

Some studies of elderly individuals with the ApoE-e4 genotype noted subtle deficits on tests of attention such as the WAIS-R Digit Span subtest, but these findings have not been consistently reported. One possible explanation for the inconsistent results could be the presence of subgroups of e4+ individuals with asymmetric cognitive profiles (i.e., significant discrepancies between verbal and visuospatial skills). Comparing genotype groups with individual, modality-specific tests might obscure subtle differences between verbal and visuospatial attention in these asymmetric subgroups. In this study, we administered the WAIS-R Digit Span and WMS-R Visual Memory Span subtests to 21 nondemented elderly e4+ individuals and 21 elderly e4- individuals matched on age, education, and overall cognitive ability. We hypothesized that a) the e4+ group would show a higher incidence of asymmetric cognitive profiles when comparing Digit Span/Visual Memory Span performance relative to the e4- group; and (b) an analysis of individual test performance would fail to reveal differences between the two subject groups. Although the groups' performances were comparable on the individual attention span tests, the e4+ group showed a significantly larger discrepancy between digit span and spatial span scores compared to the e4- group. These findings suggest that contrast measures of modality-specific attentional skills may be more sensitive to subtle group differences in at-risk groups, even when the groups do not differ on individual comparisons of standardized test means. The increased discrepancy between verbal and visuospatial attention may reflect the presence of "subgroups" within the ApoE-e4 group that are qualitatively similar to asymmetric subgroups commonly associated with the earliest stages of AD.

Genetic manipulation of longevity-related genes as a tool to regulate yeast life span and metabolite production during winemaking

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Orozco Helena

2013-01-01

Full Text Available Abstract Background Yeast viability and vitality are essential for different industrial processes where the yeast Saccharomyces cerevisiae is used as a biotechnological tool. Therefore, the decline of yeast biological functions during aging may compromise their successful biotechnological use. Life span is controlled by a variety of molecular mechanisms, many of which are connected to stress tolerance and genomic stability, although the metabolic status of a cell has proven a main factor affecting its longevity. Acetic acid and ethanol accumulation shorten chronological life span (CLS, while glycerol extends it. Results Different age-related gene classes have been modified by deletion or overexpression to test their role in longevity and metabolism. Overexpression of histone deacetylase SIR2 extends CLS and reduces acetate production, while overexpression of SIR2 homolog HST3 shortens CLS, increases the ethanol level, and reduces acetic acid production. HST3 overexpression also enhances ethanol tolerance. Increasing tolerance to oxidative stress by superoxide dismutase SOD2 overexpression has only a moderate positive effect on CLS. CLS during grape juice fermentation has also been studied for mutants on several mRNA binding proteins that are regulators of gene expression at the posttranscriptional level; we found that NGR1 and UTH4 deletions decrease CLS, while PUF3 and PUB1 deletions increase it. Besides, the pub1Δ mutation increases glycerol production and blocks stress granule formation during grape juice fermentation. Surprisingly, factors relating to apoptosis, such as caspase Yca1 or apoptosis-inducing factor Aif1, play a positive role in yeast longevity during winemaking as their deletions shorten CLS. Conclusions Manipulation of regulators of gene expression at both transcriptional (i.e., sirtuins and posttranscriptional (i.e., mRNA binding protein Pub1 levels allows to modulate yeast life span during its biotechnological use. Due to

Rapid change of field line connectivity and reconnection in stochastic magnetic fields

International Nuclear Information System (INIS)

Huang, Yi-Min; Bhattacharjee, A.; Boozer, Allen H.

2014-01-01

Magnetic fields without a direction of continuous symmetry have the generic feature that neighboring field lines exponentiate away from each other and become stochastic, and hence the ideal constraint of preserving magnetic field line connectivity becomes exponentially sensitive to small deviations from ideal Ohm's law. The idea of breaking field line connectivity by stochasticity as a mechanism for fast reconnection is tested with numerical simulations based on reduced magnetohydrodynamics equations with a strong guide field line-tied to two perfectly conducting end plates. Starting from an ideally stable force-free equilibrium, the system is allowed to undergo resistive relaxation. Two distinct phases are found in the process of resistive relaxation. During the quasi-static phase, rapid change of field line connectivity and strong induced flow are found in regions of high field line exponentiation. However, although the field line connectivity of individual field lines can change rapidly, the overall pattern of field line mapping appears to deform gradually. From this perspective, field line exponentiation appears to cause enhanced diffusion rather than reconnection. In some cases, resistive quasi-static evolution can cause the ideally stable initial equilibrium to cross a stability threshold, leading to formation of intense current filaments and rapid change of field line mapping into a qualitatively different pattern. It is in this onset phase that the change of field line connectivity is more appropriately designated as magnetic reconnection. Our results show that rapid change of field line connectivity appears to be a necessary, but not a sufficient condition for fast reconnection.

Global Processing Speed as a Mediator of Developmental Changes in Children's Auditory Memory Span

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Ferguson, A.N.; Bowey, J.A.

2005-01-01

This study examined the role of global processing speed in mediating age increases in auditory memory span in 5- to 13-year-olds. Children were tested on measures of memory span, processing speed, single-word speech rate, phonological sensitivity, and vocabulary. Structural equation modeling supported a model in which age-associated increases in…

Influence of the Visual Attention Span on Child Reading Performance: A Cross-Sectional Study

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Bosse, Marie-Line; Valdois, Sylviane

2009-01-01

The visual attention (VA) span deficit hypothesis was found successfully to account for variability in developmental dyslexia (Bosse, Tainturier & Valdois, 2007). We conducted a cross-sectional study on 417 typically developing children from first, third and fifth grades examining the role of VA span on the development of reading skills. A battery…

Managerial span of control: a pilot study comparing departmental complexity and number of direct reports.

Science.gov (United States)

Merrill, Katreena Collette; Pepper, Ginette; Blegen, Mary

2013-09-01

Nurse managers play pivotal roles in hospitals. However, restructuring has resulted in nurse managers having wider span of control and reduced visibility. The purpose of this pilot study was to compare two methods of measuring span of control: departmental complexity and number of direct reports. Forty-one nurse managers across nine hospitals completed The Ottawa Hospital Clinical Manager Span of Control Tool (TOH-SOC) and a demographic survey. A moderate positive relationship between number of direct reports and departmental complexity score was identified (r=.49, p=managers' responsibility. Copyright © 2013 Longwoods Publishing.

Research on Collapse Process of Cable-Stayed Bridges under Strong Seismic Excitations

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Xuewei Wang

2017-01-01

Full Text Available In order to present the collapse process and failure mechanism of long-span cable-stayed bridges under strong seismic excitations, a rail-cum-road steel truss cable-stayed bridge was selected as engineering background, the collapse failure numerical model of the cable-stayed bridge was established based on the explicit dynamic finite element method (FEM, and the whole collapse process of the cable-stayed bridge was analyzed and studied with three different seismic waves acted in the horizontal longitudinal direction, respectively. It can be found from the numerical simulation analysis that the whole collapse failure process and failure modes of the cable-stayed bridge under three different seismic waves are similar. Furthermore, the piers and the main pylons are critical components contributing to the collapse of the cable-stayed bridge structure. However, the cables and the main girder are damaged owing to the failure of piers and main pylons during the whole structure collapse process, so the failure of cable and main girder components is not the main reason for the collapse of cable-stayed bridge. The analysis results can provide theoretical basis for collapse resistance design and the determination of critical damage components of long-span highway and railway cable-stayed bridges in the research of seismic vulnerability analysis.

Lane Changing Control to Reduce Traffic Load Effect on Long-Span Bridges

OpenAIRE

Caprani, Colin C; Enright, Bernard; Carey, Colm

2012-01-01

Long span bridges are critical parts of a nation’s infrastructure network and congested traffic loading is the governing form of traffic loading. Groups of trucks travelling in conveys are created when fast-er moving vehicles, such as cars, change lane. In this research the authors investigate how the control of these lane-changing events can help reduce the traffic load effects on long span bridges. Real traffic data is used to simulate a traffic stream on a virtual road and bridge using a m...

Polarisation independent bi-directional four wave mixing for mid span spectral inversion

DEFF Research Database (Denmark)

Clausen, Anders; Buxens, Alvaro A.; Poulsen, Henrik Nørskov

1999-01-01

Polarisation independent Four Wave Mixing in a Semiconductor Optical Amplifier used for Mid Span Spectral Inversion (MSSI) is implemented and introduce only 0.9 dB penalty compared to polarisation dependent MSSI. The polarisation dependence in receiver sensitivity is 1 dB.......Polarisation independent Four Wave Mixing in a Semiconductor Optical Amplifier used for Mid Span Spectral Inversion (MSSI) is implemented and introduce only 0.9 dB penalty compared to polarisation dependent MSSI. The polarisation dependence in receiver sensitivity is 1 dB....

Measures of digit span and verbal rehearsal speed in deaf children after more than 10 years of cochlear implantation.

Science.gov (United States)

Pisoni, David B; Kronenberger, William G; Roman, Adrienne S; Geers, Ann E

2011-02-01

-hearing adolescents. Verbal rehearsal speed at ages 8 to 9 yrs was also found to be strongly correlated with speech and language outcomes and Digit Span scores in adolescence. Despite improvement after 8 additional years of CI use, measures of immediate verbal memory capacity and verbal rehearsal speed, which reflect core fundamental information processing skills associated with representational efficiency and information processing capacity, continue to be delayed in children with CIs relative to NH peers. Furthermore, immediate verbal memory capacity and verbal rehearsal speed at 8 to 9 yrs of age were both found to predict speech and language outcomes in adolescence, demonstrating the important contribution of these processing measures for speech-language development in children with CIs. Understanding the relations between these core underlying processes and speech-language outcomes in children with CIs may help researchers to develop new approaches to intervention and treatment of deaf children who perform poorly with their CIs. Moreover, this knowledge could be used for early identification of deaf children who may be at high risk for poor speech and language outcomes after cochlear implantation as well as for the development of novel targeted interventions that focus selectively on these core elementary information processing variables.

The rate of source memory decline across the adult life span.

Science.gov (United States)

Cansino, Selene; Estrada-Manilla, Cinthya; Hernández-Ramos, Evelia; Martínez-Galindo, Joyce Graciela; Torres-Trejo, Frine; Gómez-Fernández, Tania; Ayala-Hernández, Mariana; Osorio, David; Cedillo-Tinoco, Melisa; Garcés-Flores, Lissete; Gómez-Melgarejo, Sandra; Beltrán-Palacios, Karla; Guadalupe García-Lázaro, Haydée; García-Gutiérrez, Fabiola; Cadena-Arenas, Yadira; Fernández-Apan, Luisa; Bärtschi, Andrea; Resendiz-Vera, Julieta; Rodríguez-Ortiz, María Dolores

2013-05-01

Previous studies have suggested that the ability to remember contextual information related to specific episodic experiences declines with advancing age; however, the exact moment in the adult life span when this deficit begins is still controversial. Source memory for spatial information was tested in a life span sample of 1,500 adults between the ages of 21 and 80. Initially, images of common objects were randomly presented on one quadrant of a screen while the participants judged whether they were natural or artificial. During the retrieval phase, these same images were mixed with new ones, and all images were displayed in the center of the screen. The participants were asked to judge whether each image was new or old, and whether it was old, to indicate in which quadrant of the screen it had originally been presented. Source accuracy decreased linearly with advancing age at a rate of 0.6% per year across all decades even after controlling for educational level; this decline was unaffected by sex. These results reveal that either spatial information becomes less efficiently bound to episodic representations over time or that the ability to retrieve this information decreases gradually throughout the adult life span.

Superior Parietal Lobule Dysfunction in a Homogeneous Group of Dyslexic Children with a Visual Attention Span Disorder

Science.gov (United States)

Peyrin, C.; Demonet, J. F.; N'Guyen-Morel, M. A.; Le Bas, J. F.; Valdois, S.

2011-01-01

A visual attention (VA) span disorder has been reported in dyslexic children as potentially responsible for their poor reading outcome. The purpose of the current paper was to identify the cerebral correlates of this VA span disorder. For this purpose, 12 French dyslexic children with severe reading and VA span disorders and 12 age-matched control…

Is selective mutism associated with deficits in memory span and visual memory?: An exploratory case-control study.

Science.gov (United States)

Kristensen, Hanne; Oerbeck, Beate

2006-01-01

Our main aim in this study was to explore the association between selective mutism (SM) and aspects of nonverbal cognition such as visual memory span and visual memory. Auditory-verbal memory span was also examined. The etiology of SM is unclear, and it probably represents a heterogeneous condition. SM is associated with language impairment, but nonspecific neurodevelopmental factors, including motor problems, are also reported in SM without language impairment. Furthermore, SM is described in Asperger's syndrome. Studies on nonverbal cognition in SM thus merit further investigation. Neuropsychological tests were administered to a clinical sample of 32 children and adolescents with SM (ages 6-17 years, 14 boys and 18 girls) and 62 nonreferred controls matched for age, gender, and socioeconomic status. We used independent t-tests to compare groups with regard to auditory-verbal memory span, visual memory span, and visual memory (Benton Visual Retention Test), and employed linear regression analysis to study the impact of SM on visual memory, controlling for IQ and measures of language and motor function. The SM group differed from controls on auditory-verbal memory span but not on visual memory span. Controlled for IQ, language, and motor function, the SM group did not differ from controls on visual memory. Motor function was the strongest predictor of visual memory performance. SM does not appear to be associated with deficits in visual memory span or visual memory. The reduced auditory-verbal memory span supports the association between SM and language impairment. More comprehensive neuropsychological studies are needed.

Existence of spanning and dominating trails and circuits

NARCIS (Netherlands)

Veldman, H.J.

1986-01-01

Let T be a trail of a graph G. T is a spanning trail (S-trail) if T contains all vertices of G. T is a dominating trail (D-trail) if every edge of G is incident with at least one vertex of T. A circuit is a nontrivial closed trail. Sufficient conditions involving lower bounds on the degree-sum of

Study on Remote Monitoring System of Crossing and Spanning Tangent Tower

Science.gov (United States)

Chen, Da-bing; Zhang, Nai-long; Zhang, Meng-ge; Wang, Ze-hua; Zhang, Yan

2017-05-01

In order to grasp the vibration state of overhead transmission line and ensure the operational security of transmission line, the remote monitoring system of crossing and spanning tangent tower was studied. By use of this system, the displacement, velocity and acceleration of the tower, and the local weather data are collected automatically, displayed on computer of remote monitoring centre through wireless network, real-time collection and transmission of vibration signals are realized. The applying results show that the system is excellent in reliability and accuracy and so on. The system can be used to remote monitoring of transmission tower of UHV power transmission lines and in large spanning areas.

Laterality effects in functional connectivity of the angular gyrus during rest and episodic retrieval.

Science.gov (United States)

Bellana, Buddhika; Liu, Zhongxu; Anderson, John A E; Moscovitch, Morris; Grady, Cheryl L

2016-01-08

The angular gyrus (AG) is consistently reported in neuroimaging studies of episodic memory retrieval and is a fundamental node within the default mode network (DMN). Its specific contribution to episodic memory is debated, with some suggesting it is important for the subjective experience of episodic recollection, rather than retrieval of objective episodic details. Across studies of episodic retrieval, the left AG is recruited more reliably than the right. We explored functional connectivity of the right and left AG with the DMN during rest and retrieval to assess whether connectivity could provide insight into the nature of this laterality effect. Using data from the publically available 1000 Functional Connectome Project, 8min of resting fMRI data from 180 healthy young adults were analysed. Whole-brain functional connectivity at rest was measured using a seed-based Partial Least Squares (seed-PLS) approach (McIntosh and Lobaugh, 2004) with bilateral AG seeds. A subsequent analysis used 6-min of rest and 6-min of unconstrained, silent retrieval of autobiographical events from a new sample of 20 younger adults. Analysis of this dataset took a more targeted approach to functional connectivity analysis, consisting of univariate pairwise correlations restricted to nodes of the DMN. The seed-PLS analysis resulted in two Latent Variables that together explained ~86% of the shared cross-block covariance. The first LV revealed a common network consistent with the DMN and engaging the AG bilaterally, whereas the second LV revealed a less robust, yet significant, laterality effect in connectivity - the left AG was more strongly connected to the DMN. Univariate analyses of the second sample again revealed better connectivity between the left AG and the DMN at rest. However, during retrieval the left AG was more strongly connected than the right to non-medial temporal (MTL) nodes of the DMN, and MTL nodes were more strongly connected to the right AG. The multivariate

Compression of women's reproductive spans in Andhra Pradesh, India

NARCIS (Netherlands)

Padmadas, SS; Hutter, [No Value; Willekens, F

CONTEXT. The total fertility rate in Andhra Pradesh, India, has recently decreased to near-replacement level; however, the reasons for the fertility decline are unknown. METHODS: Data from the second round of the National Family Health Survey were used to examine the reproductive span-the duration

A set of BAC clones spanning the human genome.

NARCIS (Netherlands)

Krzywinski, M.; Bosdet, I.; Smailus, D.; Chiu, R.; Mathewson, C.; Wye, N.; Barber, S.; Brown-John, M.; Chan, S.; Chand, S.; Cloutier, A.; Girn, N.; Lee, D.; Masson, A.; Mayo, M.; Olson, T.; Pandoh, P.; Prabhu, A.L.; Schoenmakers, E.F.P.M.; Tsai, M.Y.; Albertson, D.; Lam, W.W.; Choy, C.O.; Osoegawa, K.; Zhao, S.; Jong, P.J. de; Schein, J.; Jones, S.; Marra, M.A.

2004-01-01

Using the human bacterial artificial chromosome (BAC) fingerprint-based physical map, genome sequence assembly and BAC end sequences, we have generated a fingerprint-validated set of 32 855 BAC clones spanning the human genome. The clone set provides coverage for at least 98% of the human

Accretion disc dynamo activity in local simulations spanning weak-to-strong net vertical magnetic flux regimes

Science.gov (United States)

Salvesen, Greg; Simon, Jacob B.; Armitage, Philip J.; Begelman, Mitchell C.

2016-03-01

Strongly magnetized accretion discs around black holes have attractive features that may explain enigmatic aspects of X-ray binary behaviour. The structure and evolution of these discs are governed by a dynamo-like mechanism, which channels part of the accretion power liberated by the magnetorotational instability (MRI) into an ordered toroidal magnetic field. To study dynamo activity, we performed three-dimensional, stratified, isothermal, ideal magnetohydrodynamic shearing box simulations. The strength of the self-sustained toroidal magnetic field depends on the net vertical magnetic flux, which we vary across almost the entire range over which the MRI is linearly unstable. We quantify disc structure and dynamo properties as a function of the initial ratio of mid-plane gas pressure to vertical magnetic field pressure, β _0^mid = p_gas / p_B. For 10^5 ≥ β _0^mid ≥ 10 the effective α-viscosity parameter scales as a power law. Dynamo activity persists up to and including β _0^mid = 10^2, at which point the entire vertical column of the disc is magnetic pressure dominated. Still stronger fields result in a highly inhomogeneous disc structure, with large density fluctuations. We show that the turbulent steady state βmid in our simulations is well matched by the analytic model of Begelman et al. describing the creation and buoyant escape of toroidal field, while the vertical structure of the disc can be broadly reproduced using this model. Finally, we discuss the implications of our results for observed properties of X-ray binaries.

Measuring working memory in aphasia: Comparing performance on complex span and N-back tasks

Directory of Open Access Journals (Sweden)

Maria Ivanova

2014-04-01

No significant correlations were observed between performance on complex span task and N-back tasks.Furthermore, performance on the modified listening span was related to performance on the comprehension subtest of the QASA, while no relationship was found for 2-back and 0-back tasks.Our results mirror studies in healthy controls that demonstrated no relationship between performance on the two tasks(Jaeggi et al., 2010; Kane et al., 2007. Thus although N-back tasks seem similar to traditional complex span measures and may also index abilities related to cognitive processing, the evidence to date does not warrant their direct association with the construct of WM. Implications for future investigation of cognitive deficits in aphasia will be discussed.

Comparing Intrinsic Connectivity Models for the Primary Auditory Cortices

Science.gov (United States)

Hamid, Khairiah Abdul; Yusoff, Ahmad Nazlim; Mohamad, Mazlyfarina; Hamid, Aini Ismafairus Abd; Manan, Hanani Abd

2010-07-01

This fMRI study is about modeling the intrinsic connectivity between Heschl' gyrus (HG) and superior temporal gyrus (STG) in human primary auditory cortices. Ten healthy male subjects participated and required to listen to white noise stimulus during the fMRI scans. Two intrinsic connectivity models comprising bilateral HG and STG were constructed using statistical parametric mapping (SPM) and dynamic causal modeling (DCM). Group Bayes factor (GBF), positive evidence ratio (PER) and Bayesian model selection (BMS) for group studies were used in model comparison. Group results indicated significant bilateral asymmetrical activation (puncorr < 0.001) in HG and STG. Comparison results showed strong evidence of Model 2 as the preferred model (STG as the input center) with GBF value of 5.77 × 1073 The model is preferred by 6 out of 10 subjects. The results were supported by BMS results for group studies. One-sample t-test on connection values obtained from Model 2 indicates unidirectional parallel connections from STG to bilateral HG (p<0.05). Model 2 was determined to be the most probable intrinsic connectivity model between bilateral HG and STG when listening to white noise.

M-AMST: an automatic 3D neuron tracing method based on mean shift and adapted minimum spanning tree.

Science.gov (United States)

Wan, Zhijiang; He, Yishan; Hao, Ming; Yang, Jian; Zhong, Ning

2017-03-29

Understanding the working mechanism of the brain is one of the grandest challenges for modern science. Toward this end, the BigNeuron project was launched to gather a worldwide community to establish a big data resource and a set of the state-of-the-art of single neuron reconstruction algorithms. Many groups contributed their own algorithms for the project, including our mean shift and minimum spanning tree (M-MST). Although M-MST is intuitive and easy to implement, the MST just considers spatial information of single neuron and ignores the shape information, which might lead to less precise connections between some neuron segments. In this paper, we propose an improved algorithm, namely M-AMST, in which a rotating sphere model based on coordinate transformation is used to improve the weight calculation method in M-MST. Two experiments are designed to illustrate the effect of adapted minimum spanning tree algorithm and the adoptability of M-AMST in reconstructing variety of neuron image datasets respectively. In the experiment 1, taking the reconstruction of APP2 as reference, we produce the four difference scores (entire structure average (ESA), different structure average (DSA), percentage of different structure (PDS) and max distance of neurons' nodes (MDNN)) by comparing the neuron reconstruction of the APP2 and the other 5 competing algorithm. The result shows that M-AMST gets lower difference scores than M-MST in ESA, PDS and MDNN. Meanwhile, M-AMST is better than N-MST in ESA and MDNN. It indicates that utilizing the adapted minimum spanning tree algorithm which took the shape information of neuron into account can achieve better neuron reconstructions. In the experiment 2, 7 neuron image datasets are reconstructed and the four difference scores are calculated by comparing the gold standard reconstruction and the reconstructions produced by 6 competing algorithms. Comparing the four difference scores of M-AMST and the other 5 algorithm, we can conclude that

Connections of the superior paraolivary nucleus of the rat: II. Reciprocal connections with the tectal longitudinal column

Directory of Open Access Journals (Sweden)

Antonio eViñuela

2011-02-01

Full Text Available The superior paraolivary nucleus (SPON, a prominent GABAergic center of the mammalian auditory brainstem, projects to the ipsilateral inferior colliculus (IC and sends axons through the commissure of the IC (CoIC. Herein we demonstrate that the SPON is reciprocally connected with the recently discovered tectal longitudinal column (TLC. The TLC is a long and narrow structure that spans nearly the entire midbrain tectum longitudinally, immediately above the periaqueductal gray matter (PAG and very close to the midline.Unilateral injections of biotinylated dextran into the SPON of the rat label abundant terminal fibers in the TLC of both sides, with an ipsilateral predominance. The SPON provides a dense innervation of the entire rostrocaudal extent of the ipsilateral TLC, and a relatively sparser innervation of the caudal and rostral portions of the contralateral TLC. SPON fibers reach the TLC by two routes: as collaterals of axons of the CoIC, and as axons that circumvent the ipsilateral IC before traveling in the deep layers of the superior colliculus.The density of these projections identifies SPON as a significant source of input to the TLC. Other targets of the SPON discovered in this study include the deep layers of the superior colliculus and the PAG. The same experiments reveal numerous labeled cell bodies in the TLC, interspersed among the labeled SPON fibers. This observation suggests that the SPON is a significant target of TLC projections.The discovery of novel reciprocal connections between the SPON and the TLC opens unexpected avenues for investigation of sound processing in mammalian brainstem circuits.

Effect of sensory and motor connectivity on hand function in pediatric hemiplegia.

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Gupta, Disha; Barachant, Alexandre; Gordon, Andrew M; Ferre, Claudio; Kuo, Hsing-Ching; Carmel, Jason B; Friel, Kathleen M

2017-11-01

We tested the hypothesis that somatosensory system injury would more strongly affect movement than motor system injury in children with unilateral cerebral palsy (USCP). This hypothesis was based on how somatosensory and corticospinal circuits adapt to injury during development; whereas the motor system can maintain connections to the impaired hand from the uninjured hemisphere, this does not occur in the somatosensory system. As a corollary, cortical injury strongly impairs sensory function, so we hypothesized that cortical lesions would impair hand function more than subcortical lesions. Twenty-four children with unilateral cerebral palsy had physiological and anatomical measures of the motor and somatosensory systems and lesion classification. Motor physiology was performed with transcranial magnetic stimulation and somatosensory physiology with vibration-evoked electroencephalographic potentials. Tractography of the corticospinal tract and the medial lemniscus was performed with diffusion tensor imaging, and lesions were classified by magnetic resonance imaging. Anatomical and physiological results were correlated with measures of hand function using 2 independent statistical methods. Children with disruptions in the somatosensory connectivity and cortical lesions had the most severe upper extremity impairments, particularly somatosensory function. Motor system connectivity was significantly correlated with bimanual function, but not unimanual function or somatosensory function. Both sensory and motor connectivity impact hand function in children with USCP. Somatosensory connectivity could be an important target for recovery of hand function in children with USCP. Ann Neurol 2017;82:766-780. © 2017 American Neurological Association.

In vivo optogenetic tracing of functional corticocortical connections between motor forelimb areas

Directory of Open Access Journals (Sweden)

Riichiro eHira

2013-04-01

Full Text Available Interactions between distinct motor cortical areas are essential for coordinated motor behaviors. In rodents, the motor cortical forelimb areas are divided into at least two distinct areas: the rostral forelimb area (RFA and the caudal forelimb area (CFA. The RFA is thought to be an equivalent of the premotor cortex in primates, whereas the CFA is believed to be an equivalent of the primary motor cortex. Although reciprocal connections between the RFA and the CFA have been anatomically identified in rats, it is unknown whether there are functional connections between these areas that can induce postsynaptic spikes. In this study, we used an in vivo Channelrhodopsin-2 photostimulation method to trace the functional connections between the mouse RFA and CFA. Simultaneous electrical recordings were utilized to detect spiking activities induced by synaptic inputs originating from photostimulated areas. This method, in combination with anatomical tracing, demonstrated that the RFA receives strong functional projections from layer 2/3 and/or layer 5a, but not from layer 5b, of the CFA. Further, the CFA receives strong projections from layer 5b neurons of the RFA. The onset latency of electrical responses evoked in remote areas upon photostimulation of the other areas was approximately 10 ms, which is consistent with the synaptic connectivity between these areas. Our results suggest that neuronal activities in the RFA and the CFA during movements are formed through asymmetric reciprocal connections.

Energy Efficient MANET Routing Using a Combination of Span and BECA/AFECA

DEFF Research Database (Denmark)

Kristensen, Mads Darø; Bouvin, Niels Olof

2008-01-01

This paper presents some novel approaches for energy efficient routing in mobile ad-hoc networks. Two known energy preserving techniques, Span and BECA/AFECA, are combined with a well-known re-active routing protocol, AODV, to create a new energy efficient routing protocol. Furthermore, the proto......This paper presents some novel approaches for energy efficient routing in mobile ad-hoc networks. Two known energy preserving techniques, Span and BECA/AFECA, are combined with a well-known re-active routing protocol, AODV, to create a new energy efficient routing protocol. Furthermore...

Multi-span Suspension Bridge with Floating Towers

OpenAIRE

Brunstad, Orjan

2013-01-01

The Norwegian Public Roads Administration (NPRA) is currently conducting a feasible study of crossing 8 fjords on the west coast of Norway. The most challenging crossing is the 3700 m wide Sognefjord. Three main concepts are under development, and one of the concepts of this crossing is a three span suspension bridge on floating towers. The floating foundation suggested is a multi-column pontoon with mooring lines to seabed. The object of this thesis was to study this bridge concept with resp...

Supporting students in building interdisciplinary connections across physics and biology

Science.gov (United States)

Turpen, Chandra

2014-03-01

Our research team has been engaged in the iterative redesign of an Introductory Physics course for Life Science (IPLS) majors to explicitly bridge biology and physics in ways that are authentic to the disciplines. Our interdisciplinary course provides students opportunities to examine how modeling decisions (e.g. knowing when and how to use different concepts, identifying implicit assumptions, making and justifying assumptions) may differ depending on canonical disciplinary aims and interests. Our focus on developing students' interdisciplinary reasoning skills requires 1) shifting course topics to focus on core ideas that span the disciplines, 2) shifting epistemological expectations, and 3) foregrounding typically tacit disciplinary assumptions. In working to build an authentic interdisciplinary course that bridges physics and biology, we pay careful attention to supporting students in constructing these bridges. This course has been shown to have important impacts: a) students seek meaningful connections between the disciplines, b) students perceive relevance and utility of ideas from different disciplines, and c) students reconcile challenging disciplinary ideas. Although our focus has been on building interdisciplinary coherence, we have succeeded in maintaining strong student learning gains on fundamental physics concepts and allowed students to deepen their understanding of challenging concepts in thermodynamics. This presentation will describe the shifts in course content and the modern pedagogical approaches that have been integrated into the course, and provide an overview of key research results from this project. These results may aid physicists in reconsidering how they can meaningfully reach life-science students. This work is supported by NSF-TUES DUE 11-22818, the HHMI NEXUS grant, and a NSF Graduate Research Fellowship (DGE 0750616).

Mapping the Developmental Constraints on Working Memory Span Performance

Science.gov (United States)

Bayliss, Donna M.; Jarrold, Christopher; Baddeley, Alan D.; Gunn, Deborah M.; Leigh, Eleanor

2004-01-01

This study investigated the constraints underlying developmental improvements in complex working memory span performance among 120 children of between 6 and 10 years of age. Independent measures of processing efficiency, storage capacity, rehearsal speed, and basic speed of processing were assessed to determine their contribution to age-related…

The effects of perceived organisational support and span of control on the organisational commitment of novice leaders.

Science.gov (United States)

Havaei, Farinaz; Dahinten, V Susan; MacPhee, Maura

2015-04-01

The purpose of this study was to examine the main and interaction effects of perceived organisational support, span of control and leadership rank on novice nurse leaders' organisational commitment. As nurse leaders' organisational commitment is eroded at times of healthcare restructuring, it is important to study factors associated with organisational commitment. Cross-sectional data from 69 novice nurse leaders, collected via mailed surveys at two time points, were analysed using hierarchical regression. The findings supported our hypotheses about the positive effect of perceived organisational support, the positive effect of leadership rank and the negative effect of span of control on novice nurse leaders' organisational commitment. In addition, perceived organisational support was shown to moderate the negative effect of span of control on novice nurse leaders' organisational commitment at time 2. Organisational strategies aimed at supporting nurse leaders, and attention to span of control, are required to enhance the organisational commitment of novice nurse leaders. Nurse leaders with a wide span of control, in particular those with little leadership experience, need to adopt leadership strategies that maximise their effectiveness, such as organising smaller work groups or teams within their wide span of control. © 2013 John Wiley & Sons Ltd.

Does resting-state connectivity reflect depressive rumination? A tale of two analyses.

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Berman, Marc G; Misic, Bratislav; Buschkuehl, Martin; Kross, Ethan; Deldin, Patricia J; Peltier, Scott; Churchill, Nathan W; Jaeggi, Susanne M; Vakorin, Vasily; McIntosh, Anthony R; Jonides, John

2014-12-01

Major Depressive Disorder (MDD) is characterized by rumination. Prior research suggests that resting-state brain activation reflects rumination when depressed individuals are not task engaged. However, no study has directly tested this. Here we investigated whether resting-state epochs differ from induced ruminative states for healthy and depressed individuals. Most previous research on resting-state networks comes from seed-based analyses with the posterior cingulate cortex (PCC). By contrast, we examined resting state connectivity by using the complete multivariate connectivity profile (i.e., connections across all brain nodes) and by comparing these results to seeded analyses. We find that unconstrained resting-state intervals differ from active rumination states in strength of connectivity and that overall connectivity was higher for healthy vs. depressed individuals. Relationships between connectivity and subjective mood (i.e., behavior) were strongly observed during induced rumination epochs. Furthermore, connectivity patterns that related to subjective mood were strikingly different for MDD and healthy control (HC) groups suggesting different mood regulation mechanisms. Copyright © 2014 Elsevier Inc. All rights reserved.

Metapopulation responses to patch connectivity and quality are masked by successional habitat dynamics.

Science.gov (United States)

Hodgson, Jenny A; Moilanen, Atte; Thomas, Chris D

2009-06-01

Many species have to track changes in the spatial distribution of suitable habitat from generation to generation. Understanding the dynamics of such species will likely require spatially explicit models, and patch-based metapopulation models are potentially appropriate. However, relatively little attention has been paid to developing metapopulation models that include habitat dynamics, and very little to testing the predictions of these models. We tested three predictions from theory about the differences between dynamic habitat metapopulations and their static counterparts using long-term survey data from two metapopulations of the butterfly Plebejus argus. As predicted, we showed first that the metapopulation inhabiting dynamic habitat had a lower level of habitat occupancy, which could not be accounted for by other differences between the metapopulations. Secondly, we found that patch occupancy did not significantly increase with increasing patch connectivity in dynamic habitat, whereas there was a strong positive connectivity-occupancy relationship in static habitat. Thirdly, we found no significant relationship between patch occupancy and patch quality in dynamic habitat, whereas there was a strong, positive quality-occupancy relationship in static habitat. Modeling confirmed that the differences in mean patch occupancy and connectivity-occupancy slope could arise without changing the species' metapopulation parameters-importantly, without changing the dependence of colonization upon connectivity. We found that, for a range of landscape scenarios, successional simulations always produced a lower connectivity-occupancy slope than comparable simulations with static patches, whether compared like-for-like or controlling for mean occupancy. We conclude that landscape-scale studies may often underestimate the importance of connectivity for species occurrence and persistence because habitat turnover can obscure the connectivity-occupancy relationship in commonly

Reading direction and the central perceptual span in Urdu and English.

Science.gov (United States)

Paterson, Kevin B; McGowan, Victoria A; White, Sarah J; Malik, Sameen; Abedipour, Lily; Jordan, Timothy R

2014-01-01

Normal reading relies on the reader making a series of saccadic eye movements along lines of text, separated by brief fixational pauses during which visual information is acquired from a region of text. In English and other alphabetic languages read from left to right, the region from which useful information is acquired during each fixational pause is generally reported to extend further to the right of each fixation than to the left. However, the asymmetry of the perceptual span for alphabetic languages read in the opposite direction (i.e., from right to left) has received much less attention. Accordingly, in order to more fully investigate the asymmetry in the perceptual span for these languages, the present research assessed the influence of reading direction on the perceptual span for bilingual readers of Urdu and English. Text in Urdu and English was presented either entirely as normal or in a gaze-contingent moving-window paradigm in which a region of text was displayed as normal at the reader's point of fixation and text outside this region was obscured. The windows of normal text extended symmetrically 0.5° of visual angle to the left and right of fixation, or asymmetrically by increasing the size of each window to 1.5° or 2.5° to either the left or right of fixation. When participants read English, performance for the window conditions was superior when windows extended to the right. However, when reading Urdu, performance was superior when windows extended to the left, and was essentially the reverse of that observed for English. These findings provide a novel indication that the perceptual span is modified by the language being read to produce an asymmetry in the direction of reading and show for the first time that such an asymmetry occurs for reading Urdu.

Reading direction and the central perceptual span in Urdu and English.

Directory of Open Access Journals (Sweden)

Kevin B Paterson

Full Text Available BACKGROUND: Normal reading relies on the reader making a series of saccadic eye movements along lines of text, separated by brief fixational pauses during which visual information is acquired from a region of text. In English and other alphabetic languages read from left to right, the region from which useful information is acquired during each fixational pause is generally reported to extend further to the right of each fixation than to the left. However, the asymmetry of the perceptual span for alphabetic languages read in the opposite direction (i.e., from right to left has received much less attention. Accordingly, in order to more fully investigate the asymmetry in the perceptual span for these languages, the present research assessed the influence of reading direction on the perceptual span for bilingual readers of Urdu and English. METHODS AND FINDINGS: Text in Urdu and English was presented either entirely as normal or in a gaze-contingent moving-window paradigm in which a region of text was displayed as normal at the reader's point of fixation and text outside this region was obscured. The windows of normal text extended symmetrically 0.5° of visual angle to the left and right of fixation, or asymmetrically by increasing the size of each window to 1.5° or 2.5° to either the left or right of fixation. When participants read English, performance for the window conditions was superior when windows extended to the right. However, when reading Urdu, performance was superior when windows extended to the left, and was essentially the reverse of that observed for English. CONCLUSION: These findings provide a novel indication that the perceptual span is modified by the language being read to produce an asymmetry in the direction of reading and show for the first time that such an asymmetry occurs for reading Urdu.

Increasing cell culture population doublings for long-term growth of finite life span human cell cultures

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Stampfer, Martha R; Garbe, James C

2015-02-24

Cell culture media formulations for culturing human epithelial cells are herein described. Also described are methods of increasing population doublings in a cell culture of finite life span human epithelial cells and prolonging the life span of human cell cultures. Using the cell culture media disclosed alone and in combination with addition to the cell culture of a compound associated with anti-stress activity achieves extended growth of pre-stasis cells and increased population doublings and life span in human epithelial cell cultures.

Memory and digit span experiment among psychology students in ...

African Journals Online (AJOL)

The study was an experiment that investigated short-term memory and digit span among the psychology students in a federal and state university in Lagos State, Nigeria. Memory is the process involved in retaining; retrieving and using information about stimuli, images, events, ideas and skills after original information was ...

Individual differences in memory span: relationship between rate of ...

African Journals Online (AJOL)

Individual differences in memory span: relationship between rate of item identification and rate of reading. AM Sunmola, CC Ukachi, JI Osu. Abstract. No Abstract Available African Journal for the Psychological Study of Social Issues Vol.4(1) 1999: 74-78. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL ...

Dyslexia in a French-Spanish bilingual girl: behavioural and neural modulations following a visual attention span intervention.

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Valdois, Sylviane; Peyrin, Carole; Lassus-Sangosse, Delphine; Lallier, Marie; Démonet, Jean-François; Kandel, Sonia

2014-04-01

We report the case study of a French-Spanish bilingual dyslexic girl, MP, who exhibited a severe visual attention (VA) span deficit but preserved phonological skills. Behavioural investigation showed a severe reduction of reading speed for both single items (words and pseudo-words) and texts in the two languages. However, performance was more affected in French than in Spanish. MP was administered an intensive VA span intervention programme. Pre-post intervention comparison revealed a positive effect of intervention on her VA span abilities. The intervention further transferred to reading. It primarily resulted in faster identification of the regular and irregular words in French. The effect of intervention was rather modest in Spanish that only showed a tendency for faster word reading. Text reading improved in the two languages with a stronger effect in French but pseudo-word reading did not improve in either French or Spanish. The overall results suggest that VA span intervention may primarily enhance the fast global reading procedure, with stronger effects in French than in Spanish. MP underwent two fMRI sessions to explore her brain activations before and after VA span training. Prior to the intervention, fMRI assessment showed that the striate and extrastriate visual cortices alone were activated but none of the regions typically involved in VA span. Post-training fMRI revealed increased activation of the superior and inferior parietal cortices. Comparison of pre- and post-training activations revealed significant activation increase of the superior parietal lobes (BA 7) bilaterally. Thus, we show that a specific VA span intervention not only modulates reading performance but further results in increased brain activity within the superior parietal lobes known to housing VA span abilities. Furthermore, positive effects of VA span intervention on reading suggest that the ability to process multiple visual elements simultaneously is one cause of successful

Multiple, connective intellection: the condition for invention

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C S (Fanie de Beer

2015-11-01

Full Text Available Since this article involves invention, the conditions for inventiveness become the issue: assuming multiple reality; thinking in a special way; transgressing boundaries; acknowledging networks (in the terms of Michel Serres: communication, transduction, interference, distribution, passages between the sciences. There are, however, misplaced expectations: technology should work wonders in this regard while forgetting that humans, redefined though, remain the key to establish connections and networks between people, paradigms, disciplines, sciences and technologies. Against this background, Michel Serres’s emphasis on invention and “thinking as invention” and his a-critical anti-method – ‘connective, multiple intellection’ which is a special kind of thought – are desperately needed. Guattari’s articulation of the three ecologies and the ecosophic views he developed in this regard provides a significant amplification of the approach of ‘multiple connective intellection’. These insights can be enlightened and strongly driven home through the views of Latour with an anthropological and socio-dynamic perspective on the scientific endeavour with the articulation of the actor-network theory inherited from Serres. The thoughtful beyond-methodology of Edgar Morin with his strong noological position as the ultimate condition for inventiveness, and Gregory Ulmer with his special emphasis on invention and inventiveness, especially with the help and assistance of electronic means (video and internet, and with his work with the architect Bernard Tschumi on invention and inventiveness, are of special significance in the sphere of inventiveness, the real and final guarantee for a spirited re-enchantment of the world as well as the final demonstration that the battle for intelligence as opposed to ignorance, stupidity and barbarism can be fought with great hope to succeed.

Construction of exchange-correlation functionals through interpolation between the non-interacting and the strong-correlation limit

International Nuclear Information System (INIS)

Zhou, Yongxi; Ernzerhof, Matthias; Bahmann, Hilke

2015-01-01

Drawing on the adiabatic connection of density functional theory, exchange-correlation functionals of Kohn-Sham density functional theory are constructed which interpolate between the extreme limits of the electron-electron interaction strength. The first limit is the non-interacting one, where there is only exchange. The second limit is the strong correlated one, characterized as the minimum of the electron-electron repulsion energy. The exchange-correlation energy in the strong-correlation limit is approximated through a model for the exchange-correlation hole that is referred to as nonlocal-radius model [L. O. Wagner and P. Gori-Giorgi, Phys. Rev. A 90, 052512 (2014)]. Using the non-interacting and strong-correlated extremes, various interpolation schemes are presented that yield new approximations to the adiabatic connection and thus to the exchange-correlation energy. Some of them rely on empiricism while others do not. Several of the proposed approximations yield the exact exchange-correlation energy for one-electron systems where local and semi-local approximations often fail badly. Other proposed approximations generalize existing global hybrids by using a fraction of the exchange-correlation energy in the strong-correlation limit to replace an equal fraction of the semi-local approximation to the exchange-correlation energy in the strong-correlation limit. The performance of the proposed approximations is evaluated for molecular atomization energies, total atomic energies, and ionization potentials

Micro- and nanophase separations in hierarchical self-assembly of strongly amphiphilic block copolymer-based ionic supramolecules

DEFF Research Database (Denmark)

Ayoubi, Mehran Asad; Zhu, Kaizheng; Nyström, Bo

2013-01-01

block), a class of ionic supramolecules are successfully synthesized whose molecular architecture consists of a poly(styrene) PS block (Linear block) covalently connected to a strongly amphiphilic comb-like block (AmphComb block), i.e. Linear-b-AmphComb. In the melt state, these ionic supramolecules can.......20 (SLL/C and SBCC/C) and ∼0.28 (C/L). Finally, the specific influences of the strongly amphiphilic nature of the AmphComb blocks on the observed morphological and hierarchical behaviours of our system are discussed. For reference, stoichiometric strongly amphiphilic comb-like (AmphComb) ionic...

The strong-weak coupling symmetry in 2D Φ4 field models

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B.N.Shalaev

2005-01-01

Full Text Available It is found that the exact beta-function β(g of the continuous 2D gΦ4 model possesses two types of dual symmetries, these being the Kramers-Wannier (KW duality symmetry and the strong-weak (SW coupling symmetry f(g, or S-duality. All these transformations are explicitly constructed. The S-duality transformation f(g is shown to connect domains of weak and strong couplings, i.e. above and below g*. Basically it means that there is a tempting possibility to compute multiloop Feynman diagrams for the β-function using high-temperature lattice expansions. The regular scheme developed is found to be strongly unstable. Approximate values of the renormalized coupling constant g* found from duality symmetry equations are in an agreement with available numerical results.

Time Span of Discretion and Administrative Work in School Systems: Results of a Pilot Study.

Science.gov (United States)

Allison, Derek J.; Morfitt, Grace

This paper presents findings of a study that utilized Elliott Jaques' theories of organizational depth structure and time span of discretion in administrative work to examine administrators' responsibilities in two Ontario (Canada) school systems. The theory predicts that the time-span of discretion associated with the administrative tasks will…

From menarche to menopause: the fertile life span of celiac women.

Science.gov (United States)

Santonicola, Antonella; Iovino, Paola; Cappello, Carmelina; Capone, Pietro; Andreozzi, Paolo; Ciacci, Carolina

2011-10-01

We evaluated menopause-associated disorders and fertile life span in women with celiac disease (CD) under untreated conditions and after long-term treatment with a gluten-free diet. The participants were 33 women with CD after menopause (untreated CD group), 25 celiac women consuming a gluten-free diet at least 10 years before menopause (treated CD group), and 45 healthy volunteers (control group). The Menopause Rating Scale questionnaire was used to gather information on menopause-associated disorders. The International Physical Activity Questionnaire was used to acquire information on physical activity. Untreated celiac women had a shorter duration of fertile life span than did the control women because of an older age of menarche and a younger age of menopause (P menopause causes a shorter fertile period in untreated celiac women compared with control women. A gluten-free diet that started at least 10 years before menopause prolongs the fertile life span of celiac women. The perception of intensity of hot flushes and irritability is more severe in untreated celiac women than in controls. Low physical exercise and/or poorer quality of life frequently reported by untreated celiac women might be the cause of reduced discomfort tolerance, thus increasing the subjective perception of menopausal symptoms.

Toward an Integrative Science of Life-Span Development and Aging

Science.gov (United States)

Piccinin, Andrea M.

2010-01-01

The study of aging demands an integrative life-span developmental framework, involving interdisciplinary collaborations and multiple methodological approaches for understanding how and why individuals change, in both normative and idiosyncratic ways. We highlight and summarize some of the issues encountered when conducting integrative research for understanding aging-related change, including, the integration of results across different levels of analysis; the integration of theory, design, and analysis; and the synthesis of results across studies of aging. We emphasize the necessity of longitudinal designs for understanding development and aging and discuss methodological issues that should be considered for achieving reproducible research on within-person processes. It will be important that current and future studies permit opportunities for quantitative comparison across populations given the extent to which historical shifts and cultural differences influence life-span processes and aging-related outcomes. PMID:20237144

Lobular patterns of cerebellar resting-state connectivity in adults with Autism Spectrum Disorder.

Science.gov (United States)

Olivito, Giusy; Lupo, Michela; Laghi, Fiorenzo; Clausi, Silvia; Baiocco, Roberto; Cercignani, Mara; Bozzali, Marco; Leggio, Maria

2018-03-01

Autism spectrum disorder is a neurodevelopmental disorder characterized by core deficits in social functioning. Core autistics traits refer to poor social and imagination skills, poor attention-switching/strong focus of attention, exceptional attention to detail, as expressed by the autism-spectrum quotient. Over the years, the importance of the cerebellum in the aetiology of autism spectrum disorder has been acknowledged. Neuroimaging studies have provided a strong support to this view, showing both structural and functional connectivity alterations to affect the cerebellum in autism spectrum disorder. According to the underconnectivity theory, disrupted connectivity within cerebello-cerebral networks has been specifically implicated in the aetiology of autism spectrum disorder. However, inconsistent results have been generated across studies. In this study, an integrated approach has been used in a selected population of adults with autism spectrum disorder to analyse both cerebellar morphometry and functional connectivity. In individuals with autism spectrum disorder, a decreased cerebellar grey matter volume affected the right Crus II, a region showing extensive connections with cerebral areas related to social functions. This grey matter reduction correlates with the degree of autistic traits as measured by autism-spectrum quotient. Interestingly, altered functional connectivity was found between the reduced cerebellar Crus II and contralateral cerebral regions, such as frontal and temporal areas. Overall, the present data suggest that adults with autism spectrum disorder present with specific cerebellar structural alterations that may affect functional connectivity within cerebello-cerebral modules relevant to social processing and account for core autistics traits. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Large eddy simulation and laboratory experiments on the decay of grid wakes in strongly stratified flows

International Nuclear Information System (INIS)

Fraunie, P.; Berrella, S.; Chashechkin, Y.D.; Velasco, D.; Redondo, M.

2008-01-01

A detailed analysis of the flow structure resulting from the combination of turbulence and internal waves is carried out and visualized by means of the Schlieren method on waves in a strongly stratified fluid at the Laboratory of the IPM in Moscow. The joint appearance of the more regular internal wave oscillations and the small-scale turbulence that is confined vertically to the Ozmidov length scale favours the use of a simple geometrical analysis to investigate their time-space span and evolution. This provides useful information on the collapse of internal wave breaking processes in the ocean and the atmosphere. The measurements were performed under a variety of linear stratifications and different grid forcing scales, combining the grid wake and velocity shear. A numerical simulation using LES on the passage of a single bar in a linearly stratified fluid medium has been compared with the experiments identifying the different influences of the environmental agents on the actual affective vertical diffusion of the wakes. The equation of state, which connects the density and salinity, is assumed to be linear, with the coefficient of the salt contraction being included into the definition of salinity or heat. The characteristic internal waves as well as the entire beam width are related to the diameter of the bar, the Richardson number and the peak-to-peak value of oscillations. The ultimate frequency of the infinitesimal periodic internal waves is limited by the maximum buoyancy frequency relating the decrease in the vertical scale with the anisotropy of the velocity turbulent r.m.s. velocity.

Careerism, Committee Assignments and the Electoral Connection

OpenAIRE

Katz, Jonathan N.; Sala, Brian R.

1996-01-01

Most scholars agree that members of Congress are strongly motivated by their desire for reelection. This assumption implies that members of Congress adopt institutions, rules, and norms of behavior in part to serve their electoral interests. Direct tests of the electoral connection are rare, however, because significant, exogenous changes in the electoral environment are difficult to identify. We develop and test an electoral rationale for the norm of committee assignment "property rights...

Effective lagrangian for strong interactions

International Nuclear Information System (INIS)

Jain, P.

1988-01-01

We attempt to construct a realistic phenomenological Lagrangian in order to describe strong interactions. This is in general a very complicated problem and we shall explore its various aspects. We first include the vector mesons by writing down the most general chiral invariant terms proportional to the Levi-Civita symbol ε μναβ . These terms involve three unknown coefficients, which are calculated by using the experimental results of strong interaction processes. We then calculate the static nucleon properties by finding the solitonic excitations of this model. The results turn out to be, as is also the case for most other vector-pseudoscalar Lagrangians, better than the Skyrme model but are still somewhat different from the experiments. Another aspect that we shall study is the incorporation of scale anomaly of QCD into the Skyrme model. We thus introduce a scalar glueball in our Lagrangian. Here we find an interesting result that the effective glue field dynamically forms a bag for the soliton. Depending on the values of the parameters, we get either a deep bag or a shallow bag. However by including the scalar meson, we find that to get realistic scalar sector we must have the shallow bag. Finally we show some intriguing connections between the chiral quark model, in which the nucleon is described as a solitonic excitation, and the ordinary potential binding quark model

Strong dynamics and lattice gauge theory

Science.gov (United States)

Schaich, David

In this dissertation I use lattice gauge theory to study models of electroweak symmetry breaking that involve new strong dynamics. Electroweak symmetry breaking (EWSB) is the process by which elementary particles acquire mass. First proposed in the 1960s, this process has been clearly established by experiments, and can now be considered a law of nature. However, the physics underlying EWSB is still unknown, and understanding it remains a central challenge in particle physics today. A natural possibility is that EWSB is driven by the dynamics of some new, strongly-interacting force. Strong interactions invalidate the standard analytical approach of perturbation theory, making these models difficult to study. Lattice gauge theory is the premier method for obtaining quantitatively-reliable, nonperturbative predictions from strongly-interacting theories. In this approach, we replace spacetime by a regular, finite grid of discrete sites connected by links. The fields and interactions described by the theory are likewise discretized, and defined on the lattice so that we recover the original theory in continuous spacetime on an infinitely large lattice with sites infinitesimally close together. The finite number of degrees of freedom in the discretized system lets us simulate the lattice theory using high-performance computing. Lattice gauge theory has long been applied to quantum chromodynamics, the theory of strong nuclear interactions. Using lattice gauge theory to study dynamical EWSB, as I do in this dissertation, is a new and exciting application of these methods. Of particular interest is non-perturbative lattice calculation of the electroweak S parameter. Experimentally S ≈ -0.15(10), which tightly constrains dynamical EWSB. On the lattice, I extract S from the momentum-dependence of vector and axial-vector current correlators. I created and applied computer programs to calculate these correlators and analyze them to determine S. I also calculated the masses

Effect of high dose irradiation on the red cell span in rabbits

International Nuclear Information System (INIS)

Kang, T.W.; Koh, J.W.; Woo, K.S.; Lee, O.H.; Youn, C.S.

1982-01-01

As a part of studies on acute effects of high dose irradiation in vivo, the present report was carried out to evaluate the changes of the red cell life span in the white rabbits by a single whole body exposure to gamma rays from 60 Co teletherapy unit. The exposure was done in dose levels of 100, 600 and 900 rads to each experimental group of 10 rabbits. The life span apparent half survival time of red cells, and that the red cell volume in the circulting blood were measured by ICSH Reference method using 51 Cr. (Author)

Management of long span partially edentulous maxilla with fixed removable denture prosthesis.

Science.gov (United States)

Jeyavalan, Mahilan I; Narasimman, M; Venkatakrishnan, C J; Philip, Jacob M

2012-07-01

Restoration of a long span partially edentulous maxilla with tooth supported prosthesis is challenging because of inherent anatomic limitations and unfavourable biomechanics present after the loss of teeth. A tooth supported fixed-removable prosthesis is a treatment option for restoration of such long span partially edentulous maxillary arches. This prosthesis meets the requirements for esthetics, phonetics, comfort, and hygiene, as well as favourable biomechanical stress distribution to the remaining natural tooth abutments. This article presents a procedure for fabrication of a fixed-removable prosthesis that has cement-retained custom cast bar metal substructure and a ball attachment retained removable superstructure prosthesis.

Does having children extend life span? A genealogical study of parity and longevity in the Amish.

Science.gov (United States)

McArdle, Patrick F; Pollin, Toni I; O'Connell, Jeffrey R; Sorkin, John D; Agarwala, Richa; Schäffer, Alejandro A; Streeten, Elizabeth A; King, Terri M; Shuldiner, Alan R; Mitchell, Braxton D

2006-02-01

The relationship between parity and life span is uncertain, with evidence of both positive and negative relationships being reported previously. We evaluated this issue by using genealogical data from an Old Order Amish community in Lancaster, Pennsylvania, a population characterized by large nuclear families, homogeneous lifestyle, and extensive genealogical records. The analysis was restricted to the set of 2,015 individuals who had children, were born between 1749 and 1912, and survived until at least age 50 years. Pedigree structures and birth and death dates were extracted from Amish genealogies, and the relationship between parity and longevity was examined using a variance component framework. Life span of fathers increased in linear fashion with increasing number of children (0.23 years per additional child; p =.01), while life span of mothers increased linearly up to 14 children (0.32 years per additional child; p =.004) but decreased with each additional child beyond 14 (p =.0004). Among women, but not men, a later age at last birth was associated with longer life span (p =.001). Adjusting for age at last birth obliterated the correlation between maternal life span and number of children, except among mothers with ultrahigh (>14 children) parity. We conclude that high parity among men and later menopause among women may be markers for increased life span. Understanding the biological and/or social factors mediating these relationships may provide insights into mechanisms underlying successful aging.

Feeling connected to younger versus older selves: the asymmetric impact of life stage orientation.

Science.gov (United States)

O'Brien, Ed

2015-01-01

The concept of life-stage orientation is proposed. Youth is a period of time characterised by strong feelings and emotions, but weak reasoning and cognitive skill. Conversely, adulthood is characterised by strong rationality, but weak emotionality. Two studies revealed that merely bringing these concepts to mind changes real-time feelings and behaviour. Participants who were instructed to act like their "adult" selves exhibited greater self-control in a cold pressor test than control participants and those who acted like their "youth" selves (Experiment 1). However, being induced to feel connected to youth enhanced enjoyment for fun videos (Experiment 2). Hence, the extent to which people are oriented towards youth versus adulthood has asymmetric costs and benefits for the present. Connecting to youth boosts experiential capacities (in this case, enjoying oneself) at the cost of agency, whereas connecting to adulthood boosts agentic capacities (in this case, exerting will-power) at the cost of experience.

Interorganizational Trust in Business to Business E-Commercspan>e

NARCIS (Netherlands)

P. Puvanasvari Ratnasingam

2001-01-01

textabstractMost previous research in the Information Systems discipline focused on information systems and technology, e-commercspan>e applications such as Inter-Organizational Systems (IOSs), competitive advantages, and security issues. The emphasis on IOSs' gave rise to concerns about

Estimation of Stature from Arm Span in Medical Students of ...

African Journals Online (AJOL)

“Identification is an individual's birth right” United Nations. Declaration on ... stature from arm span (AS) for a region in Maharashtra, India. Subjects ... found correlation coefficient (R) of 0.89 in male and 0.90 in female using simple regression,.

The Effects of Visual Attention Span and Phonological Decoding in Reading Comprehension in Dyslexia: A Path Analysis.

Science.gov (United States)

Chen, Chen; Schneps, Matthew H; Masyn, Katherine E; Thomson, Jennifer M

2016-11-01

Increasing evidence has shown visual attention span to be a factor, distinct from phonological skills, that explains single-word identification (pseudo-word/word reading) performance in dyslexia. Yet, little is known about how well visual attention span explains text comprehension. Observing reading comprehension in a sample of 105 high school students with dyslexia, we used a pathway analysis to examine the direct and indirect path between visual attention span and reading comprehension while controlling for other factors such as phonological awareness, letter identification, short-term memory, IQ and age. Integrating phonemic decoding efficiency skills in the analytic model, this study aimed to disentangle how visual attention span and phonological skills work together in reading comprehension for readers with dyslexia. We found visual attention span to have a significant direct effect on more difficult reading comprehension but not on an easier level. It also had a significant direct effect on pseudo-word identification but not on word identification. In addition, we found that visual attention span indirectly explains reading comprehension through pseudo-word reading and word reading skills. This study supports the hypothesis that at least part of the dyslexic profile can be explained by visual attention abilities. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Non-linear impact of glutathione depletion on C. elegans life span and stress resistance

Directory of Open Access Journals (Sweden)

Nadine Urban

2017-04-01

Full Text Available The redox environment in cells and organisms is set by low-molecular mass and protein-bound thiols, with glutathione (GSH representing a major intracellular redox buffer. Subtle thiol oxidation elicits signal transduction processes and adaptive responses to cope with stressors, whereas highly oxidizing conditions may provoke cell death. We here tested how thiol depletion affects life span, stress resistance and stress signaling in the model organism Caenorhabditis elegans. Diethyl maleate (DEM, an α,β-unsaturated carbonyl compound that conjugates to GSH and other thiols, decreased C. elegans life span at a concentration of 1 mM. In contrast, low and moderate doses of DEM (10–100 µM increased mean and maximum life span and improved resistance against oxidative stress. DEM-induced life span extension was not detectable in worms deficient in either the FoxO orthologue, DAF-16, or the Nrf2 orthologue, SKN-1, pointing to a collaborative role of the two transcription factors in life span extension induced by thiol depletion. Cytoprotective target genes of DAF-16 and SKN-1 were upregulated after at least 3 days of exposure to 100 µM DEM, but not 1 mM DEM, whereas only 1 mM DEM caused upregulation of egl-1, a gene controlled by a p53-orthologue, CEP-1. In order to test whether depletion of GSH may elicit effects similar to DEM, we suppressed GSH biosynthesis in worms by attenuating γ-glutamylcysteine synthetase (gcs-1 expression through RNAi. The decline in GSH levels elicited by gcs-1 knockdown starting at young adult stage did not impair viability, but increased both stress resistance and life expectancy of the worms. In contrast, gcs-1 knockdown commencing right after hatching impaired nematode stress resistance and rendered young adult worms prone to vulval ruptures during egg-laying. Thus, modest decrease in GSH levels in young adult worms may promote stress resistance and life span, whereas depletion of GSH is detrimental to freshly

Non-linear impact of glutathione depletion on C. elegans life span and stress resistance.

Science.gov (United States)

Urban, Nadine; Tsitsipatis, Dimitrios; Hausig, Franziska; Kreuzer, Katrin; Erler, Katrin; Stein, Vanessa; Ristow, Michael; Steinbrenner, Holger; Klotz, Lars-Oliver

2017-04-01

The redox environment in cells and organisms is set by low-molecular mass and protein-bound thiols, with glutathione (GSH) representing a major intracellular redox buffer. Subtle thiol oxidation elicits signal transduction processes and adaptive responses to cope with stressors, whereas highly oxidizing conditions may provoke cell death. We here tested how thiol depletion affects life span, stress resistance and stress signaling in the model organism Caenorhabditis elegans. Diethyl maleate (DEM), an α,β-unsaturated carbonyl compound that conjugates to GSH and other thiols, decreased C. elegans life span at a concentration of 1mM. In contrast, low and moderate doses of DEM (10-100µM) increased mean and maximum life span and improved resistance against oxidative stress. DEM-induced life span extension was not detectable in worms deficient in either the FoxO orthologue, DAF-16, or the Nrf2 orthologue, SKN-1, pointing to a collaborative role of the two transcription factors in life span extension induced by thiol depletion. Cytoprotective target genes of DAF-16 and SKN-1 were upregulated after at least 3 days of exposure to 100µM DEM, but not 1mM DEM, whereas only 1mM DEM caused upregulation of egl-1, a gene controlled by a p53-orthologue, CEP-1. In order to test whether depletion of GSH may elicit effects similar to DEM, we suppressed GSH biosynthesis in worms by attenuating γ-glutamylcysteine synthetase (gcs-1) expression through RNAi. The decline in GSH levels elicited by gcs-1 knockdown starting at young adult stage did not impair viability, but increased both stress resistance and life expectancy of the worms. In contrast, gcs-1 knockdown commencing right after hatching impaired nematode stress resistance and rendered young adult worms prone to vulval ruptures during egg-laying. Thus, modest decrease in GSH levels in young adult worms may promote stress resistance and life span, whereas depletion of GSH is detrimental to freshly hatched and developing worms

Large N lattice QCD and its extended strong-weak connection to the hypersphere

International Nuclear Information System (INIS)

Christensen, Alexander S.; Myers, Joyce C.; Pedersen, Peter D.

2014-01-01

We calculate an effective Polyakov line action of QCD at large N c and large N f from a combined lattice strong coupling and hopping expansion working to second order in both, where the order is defined by the number of windings in the Polyakov line. We compare with the action, truncated at the same order, of continuum QCD on S 1 ×S d at weak coupling from one loop perturbation theory, and find that a large N c correspondence of equations of motion found in http://dx.doi.org/10.1007/JHEP10(2012)067 at leading order, can be extended to the next order. Throughout the paper, we review the background necessary for computing higher order corrections to the lattice effective action, in order to make higher order comparisons more straightforward

Fixed Parameter Evolutionary Algorithms and Maximum Leaf Spanning Trees: A Matter of Mutations

DEFF Research Database (Denmark)

Kratsch, Stefan; Lehre, Per Kristian; Neumann, Frank

2011-01-01

Evolutionary algorithms have been shown to be very successful for a wide range of NP-hard combinatorial optimization problems. We investigate the NP-hard problem of computing a spanning tree that has a maximal number of leaves by evolutionary algorithms in the context of fixed parameter tractabil...... two common mutation operators, we show that an operator related to spanning tree problems leads to an FPT running time in contrast to a general mutation operator that does not have this property....

Communication: A Jastrow factor coupled cluster theory for weak and strong electron correlation

International Nuclear Information System (INIS)

Neuscamman, Eric

2013-01-01

We present a Jastrow-factor-inspired variant of coupled cluster theory that accurately describes both weak and strong electron correlation. Compatibility with quantum Monte Carlo allows for variational energy evaluations and an antisymmetric geminal power reference, two features not present in traditional coupled cluster that facilitate a nearly exact description of the strong electron correlations in minimal-basis N 2 bond breaking. In double-ζ treatments of the HF and H 2 O bond dissociations, where both weak and strong correlations are important, this polynomial cost method proves more accurate than either traditional coupled cluster or complete active space perturbation theory. These preliminary successes suggest a deep connection between the ways in which cluster operators and Jastrow factors encode correlation

Transport regimes spanning magnetization-coupling phase space

Science.gov (United States)

Baalrud, Scott D.; Daligault, Jérôme

2017-10-01

The manner in which transport properties vary over the entire parameter-space of coupling and magnetization strength is explored. Four regimes are identified based on the relative size of the gyroradius compared to other fundamental length scales: the collision mean free path, Debye length, distance of closest approach, and interparticle spacing. Molecular dynamics simulations of self-diffusion and temperature anisotropy relaxation spanning the parameter space are found to agree well with the predicted boundaries. Comparison with existing theories reveals regimes where they succeed, where they fail, and where no theory has yet been developed.

Signal Enhancement with Variable Span Linear Filters

DEFF Research Database (Denmark)

Benesty, Jacob; Christensen, Mads Græsbøll; Jensen, Jesper Rindom

. Variable span filters combine the ideas of optimal linear filters with those of subspace methods, as they involve the joint diagonalization of the correlation matrices of the desired signal and the noise. The book shows how some well-known filter designs, e.g. the minimum distortion, maximum signal...... the time and STFT domains, and, lastly, in time-domain binaural enhancement. In these contexts, the properties of these filters are analyzed in terms of their noise reduction capabilities and desired signal distortion, and the analyses are validated and further explored in simulations....

The Effects of Visual Attention Span and Phonological Decoding in Reading Comprehension in Dyslexia: A Path Analysis

OpenAIRE

Chen, C.; Schneps, M.; Masyn, K.; Thomson, J.

2016-01-01

Increasing evidence has shown visual attention span to be a factor, distinct from phonological skills, that explains single-word identification (pseudo-word/word reading) performance in dyslexia. Yet, little is known about how well visual attention span explains text comprehension. Observing reading comprehension in a sample of 105 high school students with dyslexia, we used a pathway analysis to examine the direct and indirect path between visual attention span and reading comprehension whil...

Life-span studies of inhaled plutonium in beagle dogs

International Nuclear Information System (INIS)

Bair, W.J.

1990-04-01

In 1970 a life-span study with over 300 beagle dogs was begun to gain an understanding of long-term health effects resulting from respiratory tract intakes of plutonium and to derive risk estimates that might be applied to plutonium and other transuranic elements. Groups of beagle dogs were given single exposures to 239 PuO 2 , 238 PuO 2 , or 239 Pu(NO 3 ) 4 to obtain graded levels of initial lung burdens ranging from 1 to 1800 Bq lung. The objective of this paper is to give you a progress report on the current life-span studies of inhaled plutonium in beagle dogs at the Pacific Northwest Laboratory. I will describe the biokinetics of inhaled plutonium in dogs and the resulting health effects. I will also mention some studies directed towards understanding the mechanism leading to these effects. Finally, I will discuss the current risk estimates derived from these studies and how they might relate to plutonium exposures in humans. 5 refs., 13 figs., 4 tabs

Renewal of K-NET (National Strong-motion Observation Network of Japan)

Science.gov (United States)

Kunugi, T.; Fujiwara, H.; Aoi, S.; Adachi, S.

2004-12-01

The National Research Institute for Earth Science and Disaster Prevention (NIED) operates K-NET (Kyoshin Network), the national strong-motion observation network, which evenly covers the whole of Japan at intervals of 25 km on average. K-NET was constructed after the Hyogoken-Nambu (Kobe) earthquake in January 1995, and began operation in June 1996. Thus, eight years have passed since K-NET started, and large amounts of strong-motion records have been obtained. As technology has progressed and new technologies have become available, NIED has developed a new K-NET with improved functionality. New seismographs have been installed at 443 observatories mainly in southwestern Japan where there is a risk of strong-motion due to the Nankai and Tonankai earthquakes. The new system went into operation in June 2004, although seismographs have still to be replaced in other areas. The new seismograph (K-NET02) consists of a sensor module, a measurement module and a communication module. A UPS, a GPS antenna and a dial-up router are also installed together with a K-NET02. A triaxial accelerometer, FBA-ES-DECK (Kinemetrics Inc.) is built into the sensor module. The measurement module functions as a conventional strong-motion seismograph for high-precision observation. The communication module can perform sophisticated processes, such as calculation of the Japan Meteorological Agency (JMA) seismic intensity, continuous recording of data and near real-time data transmission. It connects to the Data Management Center (DMC) using an ISDN line. In case of a power failure, the measurement module can control the power supply to the router and the communication module to conserve battery power. One of the main features of K-NET02 is a function for processing JMA seismic intensity. K-NET02 functions as a proper seismic intensity meter that complies with the official requirements of JMA, although the old strong-motion seismograph (K-NET95) does not calculate seismic intensity. Another

Holistic life-span health outcomes among elite intercollegiate student-athletes.

Science.gov (United States)

Sorenson, Shawn C; Romano, Russell; Scholefield, Robin M; Martin, Brandon E; Gordon, James E; Azen, Stanley P; Schroeder, E Todd; Salem, George J

2014-01-01

Competitive sports are recognized as having unique health benefits and risks, and the effect of sports on life-span health among elite athletes has received increasing attention. However, supporting scientific data are sparse and do not represent modern athletes. To assess holistic life-span health and health-related quality-of-life (HRQL) among current and former National Collegiate Athletic Association student-athletes (SAs). Cross-sectional study. A large Division I university. Population-based sample of 496 university students and alumni (age 17-84 years), including SAs and an age-matched and sex-matched nonathlete (NA) control group. Participants completed anonymous, self-report questionnaires. We measured the Short-Form 12 (SF-12) physical and mental component HRQL scores and cumulative lifetime experience and relative risk of treatment for joint, cardiopulmonary, and psychosocial health concerns. Older alumni (age 43+ years) SAs reported greater joint health concerns than NAs (larger joint summary scores; P = .04; Cohen d = 0.69; probability of clinically important difference [pCID] = 77%; treatment odds ratio [OR] = 14.0, 95% confidence interval [CI] = 1.6, 126). Joint health for current and younger alumni SAs was similar to that for NAs. Older alumni reported greater cardiopulmonary health concerns than younger alumni (summary score P students (P 99.5%; OR = 7.1, 95% CI = 3.3, 15), but the risk was similar for SAs and NAs. Current SAs demonstrated evidence of better psychosocial health (summary score P = .006; d = -0.52; pCID = 40%) and mental component HRQL (P = .008; d = 0.50; pCID = 48%) versus NAs but similar psychosocial treatment odds (OR = 0.87, 95% CI = 0.39, 1.9). Psychosocial health and mental component HRQL were similar between alumni SAs and NAs. No differences were observed between SAs and NAs in physical component HRQL. The SAs demonstrated significant, clinically meaningful evidence of greater joint health concerns later in life, comparable

Age differences in five personality domains across the life span

NARCIS (Netherlands)

Allemand, Mathias; Zimprich, Daniel; Hendriks, A. A. Jolijn

The present study addresses the issue of age differences in 5 personality domains across the-life span in a cross-sectional study. In contrast to most previous studies, the present study follows a methodologically more rigorous approach to warrant that age-related differences in personality

Management of long span partially edentulous maxilla with fixed removable denture prosthesis

Directory of Open Access Journals (Sweden)

Mahilan I Jeyavalan

2012-01-01

Full Text Available Restoration of a long span partially edentulous maxilla with tooth supported prosthesis is challenging because of inherent anatomic limitations and unfavourable biomechanics present after the loss of teeth. A tooth supported fixed-removable prosthesis is a treatment option for restoration of such long span partially edentulous maxillary arches. This prosthesis meets the requirements for esthetics, phonetics, comfort, and hygiene, as well as favourable biomechanical stress distribution to the remaining natural tooth abutments. This article presents a procedure for fabrication of a fixed-removable prosthesis that has cement-retained custom cast bar metal substructure and a ball attachment retained removable superstructure prosthesis.

Effects of low dose rate irradiation on life span prolongation of human premature-aging syndrome model mice

International Nuclear Information System (INIS)

Nomura, Takaharu

2006-01-01

We previously showed that Type II diabetes model mice prolonged of their life span by life long low dose rate irradiation. We also found that antioxidant function in variety tissues of some strain of mice were enhancement after low dose/low dose rate irradiation. The prolongation of life span might depend on certain damaged level of reactive oxygen species. We thought the effect of the prolongation was due to the enhancement of the antioxidant activities after irradiation. We investigated whether the enhancement of antioxidant activities after low dose rate irradiation had an effect on life span prolongation. Four-week-old female human premature-aging syndrome model mice, kl/kl (klotho) mice, which the life span of this model mouse is about 65 days, were irradiated with gamma rays at 0.35, 0.70 or 1.2 mGy/hr. The 0.70 mGy/hr-irradiated group remarkably effected on the prolongation of their life span. Some mice of the group were extremely survived for about and more 100 days. Antioxidant activities in the irradiated groups were enhancement by low dose rate irradiation, however the dependence of the dose rates were not clearly difference. These results suggest that the antioxidant activities in this model mouse were enhanced by the low dose rate irradiation, and may make it possible to prolong the life span of this mouse. (author)

Superposed epoch analysis of physiological fluctuations: possible space weather connections.

Science.gov (United States)

Wanliss, James; Cornélissen, Germaine; Halberg, Franz; Brown, Denzel; Washington, Brien

2018-03-01

There is a strong connection between space weather and fluctuations in technological systems. Some studies also suggest a statistical connection between space weather and subsequent fluctuations in the physiology of living creatures. This connection, however, has remained controversial and difficult to demonstrate. Here we present support for a response of human physiology to forcing from the explosive onset of the largest of space weather events-space storms. We consider a case study with over 16 years of high temporal resolution measurements of human blood pressure (systolic, diastolic) and heart rate variability to search for associations with space weather. We find no statistically significant change in human blood pressure but a statistically significant drop in heart rate during the main phase of space storms. Our empirical findings shed light on how human physiology may respond to exogenous space weather forcing.

Superposed epoch analysis of physiological fluctuations: possible space weather connections

Science.gov (United States)

Wanliss, James; Cornélissen, Germaine; Halberg, Franz; Brown, Denzel; Washington, Brien

2018-03-01

There is a strong connection between space weather and fluctuations in technological systems. Some studies also suggest a statistical connection between space weather and subsequent fluctuations in the physiology of living creatures. This connection, however, has remained controversial and difficult to demonstrate. Here we present support for a response of human physiology to forcing from the explosive onset of the largest of space weather events—space storms. We consider a case study with over 16 years of high temporal resolution measurements of human blood pressure (systolic, diastolic) and heart rate variability to search for associations with space weather. We find no statistically significant change in human blood pressure but a statistically significant drop in heart rate during the main phase of space storms. Our empirical findings shed light on how human physiology may respond to exogenous space weather forcing.

Towards a large deviation theory for strongly correlated systems

International Nuclear Information System (INIS)

Ruiz, Guiomar; Tsallis, Constantino

2012-01-01

A large-deviation connection of statistical mechanics is provided by N independent binary variables, the (N→∞) limit yielding Gaussian distributions. The probability of n≠N/2 out of N throws is governed by e −Nr , r related to the entropy. Large deviations for a strong correlated model characterized by indices (Q,γ) are studied, the (N→∞) limit yielding Q-Gaussians (Q→1 recovers a Gaussian). Its large deviations are governed by e q −Nr q (∝1/N 1/(q−1) , q>1), q=(Q−1)/(γ[3−Q])+1. This illustration opens the door towards a large-deviation foundation of nonextensive statistical mechanics. -- Highlights: ► We introduce the formalism of relative entropy for a single random binary variable and its q-generalization. ► We study a model of N strongly correlated binary random variables and their large-deviation probabilities. ► Large-deviation probability of strongly correlated model exhibits a q-exponential decay whose argument is proportional to N, as extensivity requires. ► Our results point to a q-generalized large deviation theory and suggest a large-deviation foundation of nonextensive statistical mechanics.

Radio Loud AGN Unification: Connecting Jets and Accretion

Directory of Open Access Journals (Sweden)

Meyer Eileen T.

2013-12-01

Full Text Available While only a fraction of Active Galactic Nuclei are observed to host a powerful relativistic jet, a cohesive picture is emerging that radio-loud AGN may represent an important phase in the evolution of galaxies and the growth of the central super-massive black hole. I will review my own recent observational work in radio-loud AGN unification in the context of understanding how and why jets form and their the connection to different kinds of accretion and growing the black hole, along with a brief discussion of possible connections to recent modeling work in jet formation. Starting from the significant observational advances in our understanding of jetted AGN as a population over the last decade thanks to new, more sensitive instruments such as Fermi and Swift as well as all-sky surveys at all frequencies, I will lay out the case for a dichotomy in the jetted AGN population connected to accretion mode onto the black hole. In recent work, we have identified two sub-populations of radio-loud AGN which appear to be distinguished by jet structure, where low-efficiency accreting systems produce ‘weak’ jets which decelerate more rapidly than the ’strong’ jets of black holes accreting near the Eddington limit. The two classes are comprised of: (1The weak jet sources, corresponding to the less collimated, edge-darkened FR Is, with a decelerating or spine-sheath jet with velocity gradients, and (2 The strong jet sources, having fast, collimated jets, and typically displaying strong emission lines. The dichotomy in the vp-Lp plane can be understood as a "broken power sequence" in which jets exist on one branch or the other based on the particular accretion mode (Georganopolous 2011.We suggest that the intrinsic kinetic power (as measured by low-frequency, isotropic radio emission, the orientation, and the accretion rate of the SMBH system are the the fundamental axes needed for unification of radio-loud AGN by studying a well-characterized sample

Assessing working memory in children with ADHD: Minor administration and scoring changes may improve digit span backward's construct validity.

Science.gov (United States)

Wells, Erica L; Kofler, Michael J; Soto, Elia F; Schaefer, Hillary S; Sarver, Dustin E

2018-01-01

Pediatric ADHD is associated with impairments in working memory, but these deficits often go undetected when using clinic-based tests such as digit span backward. The current study pilot-tested minor administration/scoring modifications to improve digit span backward's construct and predictive validities in a well-characterized sample of children with ADHD. WISC-IV digit span was modified to administer all trials (i.e., ignore discontinue rule) and count digits rather than trials correct. Traditional and modified scores were compared to a battery of criterion working memory (construct validity) and academic achievement tests (predictive validity) for 34 children with ADHD ages 8-13 (M=10.41; 11 girls). Traditional digit span backward scores failed to predict working memory or KTEA-2 achievement (allns). Alternate administration/scoring of digit span backward significantly improved its associations with working memory reordering (r=.58), working memory dual-processing (r=.53), working memory updating (r=.28), and KTEA-2 achievement (r=.49). Consistent with prior work, these findings urge caution when interpreting digit span performance. Minor test modifications may address test validity concerns, and should be considered in future test revisions. Digit span backward becomes a valid measure of working memory at exactly the point that testing is traditionally discontinued. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neuromodulation of Behavioral and Cognitive Development across the Life Span

Science.gov (United States)

Li, Shu-Chen

2012-01-01

Among other mechanisms, behavioral and cognitive development entail, on the one hand, contextual scaffolding and, on the other hand, neuromodulation of adaptive neurocognitive representations across the life span. Key brain networks underlying cognition, emotion, and motivation are innervated by major transmitter systems (e.g., the catecholamines…

High-resolution photoacoustic tomography of resting-state functional connectivity in the mouse brain

Science.gov (United States)

Nasiriavanaki, Mohammadreza; Xia, Jun; Wan, Hanlin; Bauer, Adam Quentin; Culver, Joseph P.; Wang, Lihong V.

2014-01-01

The increasing use of mouse models for human brain disease studies presents an emerging need for a new functional imaging modality. Using optical excitation and acoustic detection, we developed a functional connectivity photoacoustic tomography system, which allows noninvasive imaging of resting-state functional connectivity in the mouse brain, with a large field of view and a high spatial resolution. Bilateral correlations were observed in eight functional regions, including the olfactory bulb, limbic, parietal, somatosensory, retrosplenial, visual, motor, and temporal regions, as well as in several subregions. The borders and locations of these regions agreed well with the Paxinos mouse brain atlas. By subjecting the mouse to alternating hyperoxic and hypoxic conditions, strong and weak functional connectivities were observed, respectively. In addition to connectivity images, vascular images were simultaneously acquired. These studies show that functional connectivity photoacoustic tomography is a promising, noninvasive technique for functional imaging of the mouse brain. PMID:24367107

Study on Cloud Security Based on Trust Spanning Tree Protocol

Science.gov (United States)

Lai, Yingxu; Liu, Zenghui; Pan, Qiuyue; Liu, Jing

2015-09-01

Attacks executed on Spanning Tree Protocol (STP) expose the weakness of link layer protocols and put the higher layers in jeopardy. Although the problems have been studied for many years and various solutions have been proposed, many security issues remain. To enhance the security and credibility of layer-2 network, we propose a trust-based spanning tree protocol aiming at achieving a higher credibility of LAN switch with a simple and lightweight authentication mechanism. If correctly implemented in each trusted switch, the authentication of trust-based STP can guarantee the credibility of topology information that is announced to other switch in the LAN. To verify the enforcement of the trusted protocol, we present a new trust evaluation method of the STP using a specification-based state model. We implement a prototype of trust-based STP to investigate its practicality. Experiment shows that the trusted protocol can achieve security goals and effectively avoid STP attacks with a lower computation overhead and good convergence performance.

Different forms of effective connectivity in primate frontotemporal pathways.

Science.gov (United States)

Petkov, Christopher I; Kikuchi, Yukiko; Milne, Alice E; Mishkin, Mortimer; Rauschecker, Josef P; Logothetis, Nikos K

2015-01-23

It is generally held that non-primary sensory regions of the brain have a strong impact on frontal cortex. However, the effective connectivity of pathways to frontal cortex is poorly understood. Here we microstimulate sites in the superior temporal and ventral frontal cortex of monkeys and use functional magnetic resonance imaging to evaluate the functional activity resulting from the stimulation of interconnected regions. Surprisingly, we find that, although certain earlier stages of auditory cortical processing can strongly activate frontal cortex, downstream auditory regions, such as voice-sensitive cortex, appear to functionally engage primarily an ipsilateral temporal lobe network. Stimulating other sites within this activated temporal lobe network shows strong activation of frontal cortex. The results indicate that the relative stage of sensory processing does not predict the level of functional access to the frontal lobes. Rather, certain brain regions engage local networks, only parts of which have a strong functional impact on frontal cortex.

The complexities of complex span: explaining individual differences in working memory in children and adults.

Science.gov (United States)

Bayliss, Donna M; Jarrold, Christopher; Gunn, Deborah M; Baddeley, Alan D

2003-03-01

Two studies are presented that investigated the constraints underlying working memory performance in children and adults. In each case, independent measures of processing efficiency and storage capacity are assessed to determine their relative importance in predicting performance on complex span tasks,which measure working memory capacity. Results show that complex span performance was independently constrained by individual differences in domain-general processing efficiency and domain-specific storage capacity. Residual variance, which may reflect the ability to coordinate storage and processing, also predicted academic achievement. These results challenge the view that complex span taps a limited-capacity resource pool shared between processing and storage operations. Rather, they are consistent with a multiple-component model in which separate resource pools support the processing and storage functions of working memory.

Designing connected marine reserves in the face of global warming.

Science.gov (United States)

Álvarez-Romero, Jorge G; Munguía-Vega, Adrián; Beger, Maria; Del Mar Mancha-Cisneros, Maria; Suárez-Castillo, Alvin N; Gurney, Georgina G; Pressey, Robert L; Gerber, Leah R; Morzaria-Luna, Hem Nalini; Reyes-Bonilla, Héctor; Adams, Vanessa M; Kolb, Melanie; Graham, Erin M; VanDerWal, Jeremy; Castillo-López, Alejandro; Hinojosa-Arango, Gustavo; Petatán-Ramírez, David; Moreno-Baez, Marcia; Godínez-Reyes, Carlos R; Torre, Jorge

2018-02-01

Marine reserves are widely used to protect species important for conservation and fisheries and to help maintain ecological processes that sustain their populations, including recruitment and dispersal. Achieving these goals requires well-connected networks of marine reserves that maximize larval connectivity, thus allowing exchanges between populations and recolonization after local disturbances. However, global warming can disrupt connectivity by shortening potential dispersal pathways through changes in larval physiology. These changes can compromise the performance of marine reserve networks, thus requiring adjusting their design to account for ocean warming. To date, empirical approaches to marine prioritization have not considered larval connectivity as affected by global warming. Here, we develop a framework for designing marine reserve networks that integrates graph theory and changes in larval connectivity due to potential reductions in planktonic larval duration (PLD) associated with ocean warming, given current socioeconomic constraints. Using the Gulf of California as case study, we assess the benefits and costs of adjusting networks to account for connectivity, with and without ocean warming. We compare reserve networks designed to achieve representation of species and ecosystems with networks designed to also maximize connectivity under current and future ocean-warming scenarios. Our results indicate that current larval connectivity could be reduced significantly under ocean warming because of shortened PLDs. Given the potential changes in connectivity, we show that our graph-theoretical approach based on centrality (eigenvector and distance-weighted fragmentation) of habitat patches can help design better-connected marine reserve networks for the future with equivalent costs. We found that maintaining dispersal connectivity incidentally through representation-only reserve design is unlikely, particularly in regions with strong asymmetric patterns of

Stock market network’s topological stability: Evidence from planar maximally filtered graph and minimal spanning tree

Science.gov (United States)

Yan, Xin-Guo; Xie, Chi; Wang, Gang-Jin

2015-08-01

We study the topological stability of stock market network by investigating the topological robustness, namely the ability of the network to resist structural or topological changes. The stock market network is extracted by minimal spanning tree (MST) and planar maximally filtered graph (PMFG). We find that the specific delisting thresholds of the listed companies exist in both MST and PMFG networks. In comparison with MST, PMFG provides more information and is better for the aim of exploring stock market network’s robustness. The PMFG before the US sub-prime crisis (i.e., from June 2005 to May 2007) has a stronger robustness against the intentional topological damage than the other two sub-periods (i.e., from June 2007 to May 2009 and from June 2009 to May 2011). We also find that the nonfractal property exists in MSTs of S&P 500, i.e., the highly connected nodes link with each other directly, which indicates that the MSTs are vulnerable to the removal of such important nodes. Moreover, the financial institutions and high technology companies are important in maintaining the stability of S&P 500 network.

A formal analysis of a dynamic distributed spanning tree algorithm

NARCIS (Netherlands)

Mooij, A.J.; Wesselink, J.W.

2003-01-01

Abstract. We analyze the spanning tree algorithm in the IEEE 1394.1 draft standard, which correctness has not previously been proved. This algorithm is a fully-dynamic distributed graph algorithm, which, in general, is hard to develop. The approach we use is to formally develop an algorithm that is

Redesign of a Life Span Development Course Using Fink's Taxonomy

Science.gov (United States)

Fallahi, Carolyn R.

2008-01-01

This study compared a traditional lecture-based life span development course to the same course redesigned using Fink's (2003) taxonomy of significant learning. The goals, activities, and feedback within the course corresponded to Fink's 6 taxa (knowledge, application, integration, human dimension, caring, learning how to learn). Undergraduates in…

Span-Dependent Distributions of the Bending Strength of Spruce Timber

DEFF Research Database (Denmark)

Ditlevsen, Ove; Källsner, Bo

2005-01-01

Tests data of bending strengths of a large number of timber beams of different spans obtained at the Swedish Institute for Wood Technology Research reveal a statistical structure that can be represented in a simple probabilistic model of series system type. A particular feature of the data from one...

BODY HEIGHT AND ITS ESTIMATION UTILIZING ARM SPAN MEASUREMENTS IN MALE ADOLESCENTS FROM CENTRAL REGION IN MONTENEGRO

Directory of Open Access Journals (Sweden)

Dobrislav Vujović

2015-05-01

Full Text Available Anthropologists recognized the tallness of nations in the Dinaric Alps long time ago (Popovic et al, 2013. As the modern Montenegrins fall partly into the Dinaric racial classification (Bjelica et al., 2012, the purpose of this study was to examine the body height in Montenegrin male adolescents from central region as well as the relationship between arm span as an alternative to estimating the body height, which would vary from region to region in Montenegro. Method: Our investigation analyses 548 male adolescents from the central region in Montenegro. The anthropometric measurements were taken according to the protocol of the International Society for the Advancement of Kinanthropometry (ISAK. Means and standard deviations regarding the anthropometric measurements were obtained. A comparison of means of body heights and arm spans within this gender group were carried out using a t-test. The relationships between body height and arm span were determined using simple correlation coefficients and their 95% confidence interval. Then a linear regression analysis was performed to examine the extent to which the arm span can reliably predict body height. Results: The results displayed that male Central-Montenegrins are 183.66±6.93 cm tall and have an arm span of 184.99±8.30cm. Discussion: Compared to other studies, the results of this study have shown that this gender made Central-Macedonians the tall population, taller than general male population in Montenegro (Bjelica et al., 2012. On the other hand, expectably, the arm span reliably predicts body height in this gender. However, the estimation equations which have been obtained in Central-Montenegrins are, different alike in general population, since arm span was closer to body heights (1.33±1.37 centimetres, more than in general population (Bjelica et al., 2012. This confirms the necessity for developing separate height models for each region in Montenegro.

The strong 3.3 micron emission line in Wolf-Rayet stars

International Nuclear Information System (INIS)

Williams, P.M.

1982-01-01

A number of Wolf-Rayet stars have been found to show in their spectra a strong emission feature at 3.28 μm, the wavelength of the 'unidentified' feature observed in some nebular spectra. From comparison of the strength of this line from stars of different spectral type and excitation, it is identified with the CIV (11-10) transition group and shown not to be connected with the circumstellar dust associated with some Wolf-Rayet stars. (author)

STUDY ON SPANNING EXTERNAL FIXATORS FOR PERIARTICULAR OPEN FRACTURES

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Prasanth Maddila

2017-04-01

Full Text Available BACKGROUND Open fractures which occur close to any fracture need immobilisation for the soft tissues to heal. Some open fractures are even fixed with provisional fixations to maintain the alignment of the fractures. The provisional fixation needs to be augmented with external support, which can be given by spanning external fixators across a joint. MATERIALS AND METHODS Our study consists of 38 open fractures of the lower limbs, which are of Gustilo-Anderson’s type IIIB, an MT4 of AO-ASIF soft tissue injury classification essentially requiring open wound management as well as fracture fixation. Wound lavage and debridements are carried out till the soft tissues show granulations. The position in which joint is immobilised is functional and with access to open wound for dressings and inspection without any displacement of the fracture as well as creeping granulation tissue. RESULTS All the cases in our study are maintained with functional position till soft tissue cover is achieved and provisional fixation is done with definitive fixation after soft tissue cover with skin grafting. CONCLUSION Spanning external fixators are useful in maintaining functional positions as well as augmenting the provisional fixation of the compound fractures.

Individual differences in phonological learning and verbal STM span.

Science.gov (United States)

Service, Elisabet; Maury, Sini; Luotoniemi, Emilia

2007-07-01

A relationship between phonological short-term memory tasks (e.g., nonword repetition, digit span) and vocabulary learning in both experimental and real-life conditions has been reported in numerous studies. A mechanism that would explain this correlation is, however, not known. The present study explores the possibility that it is the quality of phonological representations that affects both short-term recall and long-term learning of novel wordlike items. In Experiment 1, groups with relatively good and poor span for pseudowords were established. The good group was found to perform better at explicit memory tasks tapping the incidental learning of a limited stimulus pool used in an auditory immediate serial pseudoword recall task. In Experiment 2, the results of Experiment 1 were replicated when experience of correct recall was controlled. In Experiment 3, the immediate recall performance of the good group was found to benefit more than that of the poor group from syllable repetition within stimulus pools. It is concluded that the efficiency of a process that creates phonological representations is related both to short-term capacity for verbal items, and to long-term phonological learning of the structure of novel phonological items.

Materialism across the life span: An age-period-cohort analysis.

Science.gov (United States)

Jaspers, Esther D T; Pieters, Rik G M

2016-09-01

This research examined the development of materialism across the life span. Two initial studies revealed that (a) lay beliefs were that materialism declines with age and (b) previous research findings also implied a modest, negative relationship between age and materialism. Yet, previous research has considered age only as a linear control variable, thereby precluding the possibility of more intricate relationships between age and materialism. Moreover, prior studies have relied on cross-sectional data and thus confound age and cohort effects. To improve on this, the main study used longitudinal data from 8 waves spanning 9 years of over 4,200 individuals (16 to 90 years) to examine age effects on materialism while controlling for cohort and period effects. Using a multivariate multilevel latent growth model, it found that materialism followed a curvilinear trajectory across the life span, with the lowest levels at middle age and higher levels before and after that. Thus, in contrast to lay beliefs, materialism increased in older age. Moreover, age effects on materialism differed markedly between 3 core themes of materialism: acquisition centrality, possession-defined success, and acquisition as the pursuit of happiness. In particular, acquisition centrality and possession-defined success were higher at younger and older age. Independent of these age effects, older birth cohorts were oriented more toward possession-defined success, whereas younger birth cohorts were oriented more toward acquisition centrality. The economic downturn since 2008 led to a decrease in acquisition as the pursuit of happiness and in desires for personal growth, but to an increase in desires for achievement. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Strong/weak coupling duality relations for non-supersymmetric string theories

International Nuclear Information System (INIS)

Blum, J.D.; Dienes, K.R.

1998-01-01

Both the supersymmetric SO(32) and E 8 x E 8 heterotic strings in ten dimensions have known strong-coupling duals. However, it has not been known whether there also exist strong-coupling duals for the non-supersymmetric heterotic strings in ten dimensions. In this paper, we construct explicit open-string duals for the circle compactifications of several of these non-supersymmetric theories, among them the tachyon-free SO(16) x SO(16) string. Our method involves the construction of heterotic and open-string interpolating models that continuously connect non-supersymmetric strings to supersymmetric strings. We find that our non-supersymmetric dual theories have exactly the same massless spectra as their heterotic counterparts within a certain range of our interpolations. We also develop a novel method for analyzing the solitons of non-supersymmetric open-string theories, and find that the solitons of our dual theories also agree with their heterotic counterparts. These are therefore the first known examples of strong/weak coupling duality relations between non-supersymmetric, tachyon-free string theories. Finally, the existence of these strong-coupling duals allows us to examine the non-perturbative stability of these strings, and we propose a phase diagram for the behavior of these strings as a function of coupling and radius. (orig.)

Auditory and Visual Memory Span: Cognitive Processing by TMR Individuals with Down Syndrome or Other Etiologies.

Science.gov (United States)

Varnhagen, Connie K.; And Others

1987-01-01

Auditory and visual memory span were examined with 13 Down Syndrome and 15 other trainable mentally retarded young adults. Although all subjects demonstrated relatively poor auditory memory span, Down Syndrome subjects were especially poor at long-term memory access for visual stimulus identification and short-term storage and processing of…

Connective tissue fibroblasts and Tcf4 regulate myogenesis

Science.gov (United States)

Mathew, Sam J.; Hansen, Jody M.; Merrell, Allyson J.; Murphy, Malea M.; Lawson, Jennifer A.; Hutcheson, David A.; Hansen, Mark S.; Angus-Hill, Melinda; Kardon, Gabrielle

2011-01-01

Muscle and its connective tissue are intimately linked in the embryo and in the adult, suggesting that interactions between these tissues are crucial for their development. However, the study of muscle connective tissue has been hindered by the lack of molecular markers and genetic reagents to label connective tissue fibroblasts. Here, we show that the transcription factor Tcf4 (transcription factor 7-like 2; Tcf7l2) is strongly expressed in connective tissue fibroblasts and that Tcf4GFPCre mice allow genetic manipulation of these fibroblasts. Using this new reagent, we find that connective tissue fibroblasts critically regulate two aspects of myogenesis: muscle fiber type development and maturation. Fibroblasts promote (via Tcf4-dependent signals) slow myogenesis by stimulating the expression of slow myosin heavy chain. Also, fibroblasts promote the switch from fetal to adult muscle by repressing (via Tcf4-dependent signals) the expression of developmental embryonic myosin and promoting (via a Tcf4-independent mechanism) the formation of large multinucleate myofibers. In addition, our analysis of Tcf4 function unexpectedly reveals a novel mechanism of intrinsic regulation of muscle fiber type development. Unlike other intrinsic regulators of fiber type, low levels of Tcf4 in myogenic cells promote both slow and fast myogenesis, thereby promoting overall maturation of muscle fiber type. Thus, we have identified novel extrinsic and intrinsic mechanisms regulating myogenesis. Most significantly, our data demonstrate for the first time that connective tissue is important not only for adult muscle structure and function, but is a vital component of the niche within which muscle progenitors reside and is a critical regulator of myogenesis. PMID:21177349

Age- and calorie-independent life span extension from dietary restriction by bacterial deprivation in Caenorhabditis elegans

Directory of Open Access Journals (Sweden)

Sager Jennifer

2008-05-01

Full Text Available Abstract Background Dietary restriction (DR increases life span and delays age-associated disease in many organisms. The mechanism by which DR enhances longevity is not well understood. Results Using bacterial food deprivation as a means of DR in C. elegans, we show that transient DR confers long-term benefits including stress resistance and increased longevity. Consistent with studies in the fruit fly and in mice, we demonstrate that DR also enhances survival when initiated late in life. DR by bacterial food deprivation significantly increases life span in worms when initiated as late as 24 days of adulthood, an age at which greater than 50% of the cohort have died. These survival benefits are, at least partially, independent of food consumption, as control fed animals are no longer consuming bacterial food at this advanced age. Animals separated from the bacterial lawn by a barrier of solid agar have a life span intermediate between control fed and food restricted animals. Thus, we find that life span extension from bacterial deprivation can be partially suppressed by a diffusible component of the bacterial food source, suggesting a calorie-independent mechanism for life span extension by dietary restriction. Conclusion Based on these findings, we propose that dietary restriction by bacterial deprivation increases longevity in C. elegans by a combination of reduced food consumption and decreased food sensing.

Predicting scour beneath subsea pipelines from existing small free span depths under steady currents

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Jun Y. Lee

2017-06-01

Full Text Available An equation was developed to predict current-induced scour beneath subsea pipelines in areas with small span depths, S. Current equations for scour prediction are only applicable to partially buried pipelines. The existence of small span depths (i.e. S/D < 0.3 are of concern because the capacity for scour is higher at smaller span depths. Furthermore, it is impractical to perform rectification works, such as installing grout bags, under a pipeline with a small S/D. Full-scale two-dimensional computational fluid dynamics (CFD simulations were performed using the Reynolds-averaged Navier–Stokes approach and the Shear stress transport k–ω turbulence model. To predict the occurrence of scour, the computed maximum bed shear stress beneath the pipe was converted to the dimensionless Shields parameter, and compared with the critical Shields parameter based on the mean sediment grain size. The numerical setup was verified, and a good agreement was found between model-scale CFD data and experimental data. Field data were obtained to determine the mean grain size, far field current velocity and to measure the span depths along the surveyed pipe length. A trend line equation was fitted to the full-scale CFD data, whereby the maximum Shields parameter beneath the pipe can be calculated based on the undisturbed Shields parameter and S/D.

Like cognitive function, decision making across the life span shows profound age-related changes.

Science.gov (United States)

Tymula, Agnieszka; Rosenberg Belmaker, Lior A; Ruderman, Lital; Glimcher, Paul W; Levy, Ifat

2013-10-15

It has long been known that human cognitive function improves through young adulthood and then declines across the later life span. Here we examined how decision-making function changes across the life span by measuring risk and ambiguity attitudes in the gain and loss domains, as well as choice consistency, in an urban cohort ranging in age from 12 to 90 y. We identified several important age-related patterns in decision making under uncertainty: First, we found that healthy elders between the ages of 65 and 90 were strikingly inconsistent in their choices compared with younger subjects. Just as elders show profound declines in cognitive function, they also show profound declines in choice rationality compared with their younger peers. Second, we found that the widely documented phenomenon of ambiguity aversion is specific to the gain domain and does not occur in the loss domain, except for a slight effect in older adults. Finally, extending an earlier report by our group, we found that risk attitudes across the life span show an inverted U-shaped function; both elders and adolescents are more risk-averse than their midlife counterparts. Taken together, these characterizations of decision-making function across the life span in this urban cohort strengthen the conclusions of previous reports suggesting a profound impact of aging on cognitive function in this domain.

The significant surface-water connectivity of "geographically isolated wetlands"

Science.gov (United States)

Calhoun, Aram J.K.; Mushet, David M.; Alexander, Laurie C.; DeKeyser, Edward S.; Fowler, Laurie; Lane, Charles R.; Lang, Megan W.; Rains, Mark C.; Richter, Stephen; Walls, Susan

2017-01-01

We evaluated the current literature, coupled with our collective research expertise, on surface-water connectivity of wetlands considered to be “geographically isolated” (sensu Tiner Wetlands 23:494–516, 2003a) to critically assess the scientific foundation of grouping wetlands based on the singular condition of being surrounded by uplands. The most recent research on wetlands considered to be “geographically isolated” shows the difficulties in grouping an ecological resource that does not reliably indicate lack of surface water connectivity in order to meet legal, regulatory, or scientific needs. Additionally, the practice of identifying “geographically isolated wetlands” based on distance from a stream can result in gross overestimates of the number of wetlands lacking ecologically important surface-water connections. Our findings do not support use of the overly simplistic label of “geographically isolated wetlands”. Wetlands surrounded by uplands vary in function and surface-water connections based on wetland landscape setting, context, climate, and geographic region and should be evaluated as such. We found that the “geographically isolated” grouping does not reflect our understanding of the hydrologic variability of these wetlands and hence does not benefit conservation of the Nation’s diverse wetland resources. Therefore, we strongly discourage use of categorizations that provide overly simplistic views of surface-water connectivity of wetlands fully embedded in upland landscapes.

Exercise and Quality of Life: Strengthening the Connections

OpenAIRE

Hacker, Eileen

2009-01-01

Exercise improves quality of life (QOL) in people with cancer. Most oncology healthcare providers recognize the statement to be true because the research literature provides strong support for the physical and psychological benefits of exercise. Because the terms exercise, QOL, and people with cancer have different meanings, the contextual connections in which they are used are important to understanding the relationship between exercise and QOL in people with cancer. This article explores th...

"Pull and push back" concepts of longevity and life span extension.

Science.gov (United States)

Muradian, Khachik

2013-12-01

The negative relation between metabolism and life span is a fundamental gerontological discovery well documented in a variety of ontogenetic and phylogenetic models. But how the long-lived species and populations sustain lower metabolic rate and, in more general terms, what is the efficient way to decline the metabolism? The suggested 'pull and push back' hypothesis assumes that decreased Po2 (hypoxia) and/or increased [Formula: see text] (hypercapnia) may create preconditions for the declined metabolic and aging rates. However, wider implementation of such ideas is compromised because of little advances in modification of the metabolic rate. Artificial atmosphere with controlled [Formula: see text] and [Formula: see text] could be a promising approach because of the minimal external invasions and involvement of the backward and forward loops ensuring physiological self-regulation of the metabolic perturbations. General considerations and existing data indicate that manipulations of [Formula: see text] may be more efficient in life span extension than [Formula: see text]. Thus, maximum life span of mammals positively correlates with the blood [Formula: see text] and HCO3 (-) but not with [Formula: see text]. Yet, proportional decease of the body [Formula: see text] and increase of [Formula: see text] seems the most optimal regime ensuring lower losses of the energy equivalents. Furthermore, especially rewarding results could be expected when such changes are modeled without major external invasions using the animals' inner capacity to consume O2 and generate CO2, as it is typical for the extreme longevity.

Perceptual Representation as a Mechanism of Lexical Ambiguity Resolution: An Investigation of Span and Processing Time

Science.gov (United States)

Madden, Carol J.; Zwaan, Rolf A.

2006-01-01

In 2 experiments, the authors investigated the ability of high- and low-span comprehenders to construe subtle shades of meaning through perceptual representation. High- and low-span comprehenders responded to pictures that either matched or mismatched a target object's shape as implied by the preceding sentence context. At 750 ms after hearing the…

Endosomal protein sorting and autophagy genes contribute to the regulation of yeast life span.

Science.gov (United States)

Longo, Valter D; Nislow, Corey; Fabrizio, Paola

2010-11-01

Accumulating evidence from various organisms points to a role for autophagy in the regulation of life span. By performing a genome-wide screen to identify novel life span determinants in Saccharomyces cerevisiae, we have obtained further insights into the autophagy-related and -unrelated degradation processes that may be important for preventing cellular senescence. The generation of multivesicular bodies and their fusion with the vacuole in the endosomal pathway emerged as novel cell functions involved in yeast chronological survival and longevity extension.

Preliminary investigation into the zone of support influence and stable span between support units.

CSIR Research Space (South Africa)

Daehnke, A

1999-10-01

Full Text Available stability envelopes for hangingwalls with FPFs as a function of instability height, unsupported span, support load and discontinuity orientation (g = 90o – f, where f is the friction angle associated with the fracture surfaces)........................144... Figure 8.6.8 Rockburst stability envelopes for hangingwalls with FPFs as a function of instability height, unsupported span, support load and discontinuity orientation (g = 90o – f, where f is the friction angle associated with the fracture surfaces...

Analysis of the Working Cable System of Single-span Circulating Ropeway

Directory of Open Access Journals (Sweden)

Qin Jian

2017-01-01

Full Text Available Based on the analysis of the mutual interaction between bearing cable and traction cable of single-span circulating ropeway, the calculation method is proposed for working cables of ropeway with arbitrary loads. The 5 sets nonlinear equations are set up for the working cables according to the equal spans and altitude differences of the bearing cable and the traction cable, the constant of the load running space and the bearing cable length, and the tension balance of bearing cable and traction cable beside load. The resolving method is proposed based on the Newton iterative method. The correctness and feasibility of the method are proved by the results of engineering test. From the solution, the tension and coordinate of working cables can be obtained accurately, which is meaningful for the design and analysis of the freight ropeway.

Society for Promotion of Peaceful Applications of Nuclear in Kenya (SPANS)

International Nuclear Information System (INIS)

2006-01-01

The seminar was organized by the National Council for Science and Technology in collaboration with International Atomic Energy Agency (IAEA) to achieve the following objectives; create public awareness on Peaceful use of Nuclear Science and Technology discuss and adopt the draft constitution for the Society for the Promotion of Nuclear Science in Kenya SPANS (K). The National Council for Science and Technology identified highly qualified resource persons who are competent enough in the area of nuclear applications who prepared relevant topics based on their knowledge and experiences in the field of nuclear science. The presentations covered topics of nuclear applications in the areas of agriculture, health, pollution and a draft of SPANS Constitution. The Council is in the process of compiling and publishing the proceedings whose details will be submitted later to INIS once it is ready

Connecting through music with people with dementia Connecting through music with people with dementia Robin Rio Jessica Kingsley £14.99 144pp 9781843109051 1843109050 [Formula: see text].

Science.gov (United States)

2009-06-22

This book does not have a strong nursing focus as it is a guide for family and professional caregivers. It connects music with particular behaviours associated with dementia, for example, enhancing mood through the use of stimulating music or calming an agitated person by playing soothing music.

Finding significantly connected voxels based on histograms of connection strengths

DEFF Research Database (Denmark)

Kasenburg, Niklas; Pedersen, Morten Vester; Darkner, Sune

2016-01-01

We explore a new approach for structural connectivity based segmentations of subcortical brain regions. Connectivity based segmentations are usually based on fibre connections from a seed region to predefined target regions. We present a method for finding significantly connected voxels based...... on the distribution of connection strengths. Paths from seed voxels to all voxels in a target region are obtained from a shortest-path tractography. For each seed voxel we approximate the distribution with a histogram of path scores. We hypothesise that the majority of estimated connections are false-positives...... and that their connection strength is distributed differently from true-positive connections. Therefore, an empirical null-distribution is defined for each target region as the average normalized histogram over all voxels in the seed region. Single histograms are then tested against the corresponding null...

Connecting Music, Art, and Science for Increased Creativity and Topic Engagement

Directory of Open Access Journals (Sweden)

Tamara L. McNealy

2013-08-01

Full Text Available ‘Attention spans have shortened,’ is a common phrase often used in reference to today’s college students. As faculty and instructors, we need to address this issue through the utilization of innovative and creative techniques that aid in making our subjects accessible to our students. Connecting a serious topic such as microbiology with a ‘fun’ activity can increase student engagement and learning. Ideas to maintain student attention on a subject include providing information in 15- to 20-minute blocks, giving one- to two-minute assignments, and providing an active learning activity at least once per hour. But what if we could also increase their engagement with science by connecting it to things they already think of outside of class, and, in addition, make science thinking interdisciplinary? I have recently introduced exercises that connect music and art to various microbiology topics in my class. The creative processes in art and science have much in common. Albert Einstein recognized that both science and art delve into the mysterious by stating, “The most beautiful thing we can experience is the mysterious. It is the source of all true art and all science” (1. Connecting these subjects in the minds of our students will help them realize the importance of technology, industry, and progress in science and simultaneously emphasize the importance of art, music, and the humanities. The tools presented here will encourage students to connect new science information through the music and art they already know and, therefore, provide increased engagement and retention of the new knowledge. These techniques used in a microbiology class increased the amount of time spent thinking about new information, increased engagement with the information being presented, and encouraged critical thinking of microbiology topics. These tools were used in an upper level microbiology course, but the techniques can be easily incorporated into any course

Strong scintillations during atmospheric occultations Theoretical intensity spectra. [radio scattering during spacecraft occultations by planetary atmospheres

Science.gov (United States)

Hinson, D. P.

1986-01-01

Each of the two Voyager spacecraft launched in 1977 has completed a reconnaissance of the Jovian and Saturnian systems. In connection with occultation experiments, strong scintillations were observed. Further theoretical work is required before these scintillations can be interpreted. The present study is, therefore, concerned with the derivation of a theory for strong scattering during atmospheric occultation experiments, taking into account as fundamental quantity of interest the spatial spectrum (or spectral density) of intensity fluctuations. Attention is given to a theory for intensity spectra, and numerical calculations. The new formula derived for Phi-i accounts for strong scattering of electromagnetic waves during atmospheric occultations.

Sustained Attention Across the Life Span in a Sample of 10,000: Dissociating Ability and Strategy.

Science.gov (United States)

Fortenbaugh, Francesca C; DeGutis, Joseph; Germine, Laura; Wilmer, Jeremy B; Grosso, Mallory; Russo, Kathryn; Esterman, Michael

2015-09-01

Normal and abnormal differences in sustained visual attention have long been of interest to scientists, educators, and clinicians. Still lacking, however, is a clear understanding of how sustained visual attention varies across the broad sweep of the human life span. In the present study, we filled this gap in two ways. First, using an unprecedentedly large 10,430-person sample, we modeled age-related differences with substantially greater precision than have prior efforts. Second, using the recently developed gradual-onset continuous performance test (gradCPT), we parsed sustained-attention performance over the life span into its ability and strategy components. We found that after the age of 15 years, the strategy and ability trajectories saliently diverge. Strategy becomes monotonically more conservative with age, whereas ability peaks in the early 40s and is followed by a gradual decline in older adults. These observed life-span trajectories for sustained attention are distinct from results of other life-span studies focusing on fluid and crystallized intelligence. © The Author(s) 2015.

The local limit of the uniform spanning tree on dense graphs

Czech Academy of Sciences Publication Activity Database

Hladký, Jan; Nachmias, A.; Tran, Tuan

First Online: 10 January (2018) ISSN 0022-4715 R&D Projects: GA ČR GJ16-07822Y Keywords : uniform spanning tree * graph limits * Benjamini-Schramm convergence * graphon * branching process Subject RIV: BA - General Mathematics Impact factor: 1.349, year: 2016

Stature and Its Estimation Utilizing Arm Span Measurements of both gender Adolescents from Southern Region in Kosovo

Directory of Open Access Journals (Sweden)

Fitim Arifi

2018-06-01

Full Text Available This study is based on measurements of Southern region Kosovan adolescents. The aim of this study was to examine the stature of adolescents from Southern region as well relationship between arm span and stature in both Kosovar genders. A total measured subject participated in this research was 225 out of which (105 girls and 120 boys, females average of age is 18.36±0.50 years old (range 18-20 years and for male 18.40±0.55 years old (range 18-20 years.The anthropometric measurements were done by trained people and were taken according to the ISAK manual. Relationship between stature and arm span has been analyzed by the simple correlation coeffi cient at a 95% confi dence interval. The linear regression analysis was carried out to examine extent to which arm span can reliably predict of stature. Statistical importance was placed at level p<0.05. As a result anthropometric measurements for both sexes showed that the average of stature for boys adolescents from Southern region are 178.60±5.73 centimeters and have the arm span average of 180.92±6.92 centimeters, while girls from Southern 165.33±4.45 centimeters tall, and have the arm span average of 165.60±6.03 centimeters. The results have shown that the arm span was estimated as a reliable indicator of stature assessment to the both genders adolescents from Southern region of Kosovo population. This study also confi rms the necessity for developing separate height models for each region in Kosovo.

Body Height and its Estimation Utilizing Arm Span Measurements in Male Adolescents from Southern Region in Montenegro

Directory of Open Access Journals (Sweden)

Rajko Milašinović

2016-06-01

Full Text Available The purpose of this study was to examine the body height in Montenegrin male adolescents from southern region as well as the relationship between arm span as an alternative to estimating the body height, which would vary from region to region in Montenegro. Our investigation analyses 87 male adolescents from the southern region in Montenegro. The anthropometric measurements were taken according to the protocol of the International Society for the Advancement of Kinanthropometry (ISAK. Means and standard deviations regarding the anthropometric measurements were obtained. The relationships between body height and arm span were determined using simple correlation coefficients and their 95% confidence interval. Then a linear regression analysis was performed to examine the extent to which the arm span can reliably predict body height. The results displayed that male Southern-Montenegrins are 182.53±7.53 cm tall and have an arm span of 184.55±9.03 cm. Compared to other studies, the results of this study have shown that this gender made Southern- Montenegrins the tall population, taller than most of nation around the Europe. On the other hand, expectably, the arm span reliably predicts body height in this gender. However, the estimation equations which have been obtained in Southern-Montenegrins are, different alike in general population, since arm span was closer to body heights (2.03±1.50 cm, more than in general population. Hence, this study also confirms the necessity for developing separate height models for each region in Montenegro.

Image Segmentation Using Minimum Spanning Tree

Science.gov (United States)

Dewi, M. P.; Armiati, A.; Alvini, S.

2018-04-01

This research aim to segmented the digital image. The process of segmentation is to separate the object from the background. So the main object can be processed for the other purposes. Along with the development of technology in digital image processing application, the segmentation process becomes increasingly necessary. The segmented image which is the result of the segmentation process should accurate due to the next process need the interpretation of the information on the image. This article discussed the application of minimum spanning tree on graph in segmentation process of digital image. This method is able to separate an object from the background and the image will change to be the binary images. In this case, the object that being the focus is set in white, while the background is black or otherwise.

Robustness of Long Span Reciprocal Timber Structures

DEFF Research Database (Denmark)

Balfroid, Nathalie; Kirkegaard, Poul Henning

2011-01-01

engineer may take necessary steps to design robust structures that are insensitive to accidental circumstances. The present paper makes a discussion of such robustness issues related to the future development of reciprocal timber structures. The paper concludes that these kind of structures can have...... a potential as long span timber structures in real projects if they are carefully designed with respect to the overall robustness strategies.......Robustness of structural systems has obtained a renewed interest due to a much more frequent use of advanced types of structures with limited redundancy and serious consequences in case of failure. The interest has also been facilitated due to recently severe structural failures...

About Connections

Directory of Open Access Journals (Sweden)

Kathleen S Rockland

2015-05-01

Full Text Available Despite the attention attracted by connectomics, one can lose sight of the very real questions concerning What are connections? In the neuroimaging community, structural connectivity is ground truth and underlying constraint on functional or effective connectivity. It is referenced to underlying anatomy; but, as increasingly remarked, there is a large gap between the wealth of human brain mapping and the relatively scant data on actual anatomical connectivity. Moreover, connections have typically been discussed as pairwise, point x projecting to point y (or: to points y and z, or more recently, in graph theoretical terms, as nodes or regions and the interconnecting edges. This is a convenient shorthand, but tends not to capture the richness and nuance of basic anatomical properties as identified in the classic tradition of tracer studies. The present short review accordingly revisits connectional weights, heterogeneity, reciprocity, topography, and hierarchical organization, drawing on concrete examples. The emphasis is on presynaptic long-distance connections, motivated by the intention to probe current assumptions and promote discussions about further progress and synthesis.

The eye movements of dyslexic children during reading and visual search: impact of the visual attention span.

Science.gov (United States)

Prado, Chloé; Dubois, Matthieu; Valdois, Sylviane

2007-09-01

The eye movements of 14 French dyslexic children having a VA span reduction and 14 normal readers were compared in two tasks of visual search and text reading. The dyslexic participants made a higher number of rightward fixations in reading only. They simultaneously processed the same low number of letters in both tasks whereas normal readers processed far more letters in reading. Importantly, the children's VA span abilities related to the number of letters simultaneously processed in reading. The atypical eye movements of some dyslexic readers in reading thus appear to reflect difficulties to increase their VA span according to the task request.

Between strong continuity and almost continuity

Directory of Open Access Journals (Sweden)

J.K. Kohli

2010-04-01

Full Text Available As embodied in the title of the paper strong and weak variants of continuity that lie strictly between strong continuity of Levine and almost continuity due to Singal and Singal are considered. Basic properties of almost completely continuous functions (≡ R-maps and δ-continuous functions are studied. Direct and inverse transfer of topological properties under almost completely continuous functions and δ-continuous functions are investigated and their place in the hier- archy of variants of continuity that already exist in the literature is out- lined. The class of almost completely continuous functions lies strictly between the class of completely continuous functions studied by Arya and Gupta (Kyungpook Math. J. 14 (1974, 131-143 and δ-continuous functions defined by Noiri (J. Korean Math. Soc. 16, (1980, 161-166. The class of almost completely continuous functions properly contains each of the classes of (1 completely continuous functions, and (2 al- most perfectly continuous (≡ regular set connected functions defined by Dontchev, Ganster and Reilly (Indian J. Math. 41 (1999, 139-146 and further studied by Singh (Quaestiones Mathematicae 33(2(2010, 1–11 which in turn include all δ-perfectly continuous functions initi- ated by Kohli and Singh (Demonstratio Math. 42(1, (2009, 221-231 and so include all perfectly continuous functions introduced by Noiri (Indian J. Pure Appl. Math. 15(3 (1984, 241-250.

Long distance dispersal and connectivity in amphi-Atlantic corals at regional and basin scales.

Directory of Open Access Journals (Sweden)

Flavia L D Nunes

Full Text Available Among Atlantic scleractinian corals, species diversity is highest in the Caribbean, but low diversity and high endemism are observed in various peripheral populations in central and eastern Atlantic islands and along the coasts of Brazil and West Africa. The degree of connectivity between these distantly separated populations is of interest because it provides insight into processes at both evolutionary and ecological time scales, such as speciation, recruitment dynamics and the persistence of coral populations. To assess connectivity in broadly distributed coral species of the Atlantic, DNA sequence data from two nuclear markers were obtained for six coral species spanning their distributional ranges. At basin-wide scales, significant differentiation was generally observed among populations in the Caribbean, Brazil and West Africa. Concordance of patterns in connectivity among co-distributed taxa indicates that extrinsic barriers, such as the Amazon freshwater plume or long stretches of open ocean, restrict dispersal of coral larvae from region to region. Within regions, dispersal ability appears to be influenced by aspects of reproduction and life history. Two broadcasting species, Siderastrea siderea and Montastraea cavernosa, were able to maintain gene flow among populations separated by as much as 1,200 km along the coast of Brazil. In contrast, brooding species, such as Favia gravida and Siderastrea radians, had more restricted gene flow along the Brazilian coast.

Age Differences in the Intrinsic Functional Connectivity of Default Network Subsystems

Directory of Open Access Journals (Sweden)

Karen eCampbell

2013-11-01

Full Text Available Recent work suggests that the default mode network (DMN includes two core regions, the ventromedial prefrontal cortex (vmPFC and posterior cingulate cortex (PCC, and several unique subsystems that are functionally distinct. These include a medial temporal lobe (MTL subsystem, active during remembering and future projection, and a dorsomedial PFC (dmPFC subsystem, active during self-reference. The PCC has been further subdivided into ventral (vPCC and dorsal (dPCC regions that are more strongly connected with the DMN and cognitive control networks, respectively. The goal of this study was to examine age differences in resting state functional connectivity within these subsystems. After applying a rigorous procedure to reduce the effects of head motion, we used a multivariate technique to identify both common and unique patterns of functional connectivity in the MTL vs. the dmPFC, and in vPCC vs. dPCC. All four areas had robust functional connectivity with other DMN regions, and each also showed distinct connectivity patterns in both age groups. Young and older adults had equivalent functional connectivity in the MTL subsystem. Older adults showed weaker connectivity in the vPCC and dmPFC subsystems, particularly with other DMN areas, but stronger connectivity than younger adults in the dPCC subsystem, which included areas involved in cognitive control. Our data provide evidence for distinct subsystems involving DMN nodes, which are maintained with age. Nevertheless, there are age differences in the strength of functional connectivity within these subsystems, supporting prior evidence that DMN connectivity is particularly vulnerable to age, whereas connectivity involving cognitive control regions is relatively maintained. These results suggest an age difference in the integrated activity among brain networks that can have implications for cognition in older adults.

Strong non-radial propagation of energetic electrons in solar corona

Science.gov (United States)

Klassen, A.; Dresing, N.; Gómez-Herrero, R.; Heber, B.; Veronig, A.

2018-06-01

Analyzing the sequence of solar energetic electron events measured at both STEREO-A (STA) and STEREO-B (STB) spacecraft during 17-21 July 2014, when their orbital separation was 34°, we found evidence of a strong non-radial electron propagation in the solar corona below the solar wind source surface. The impulsive electron events were associated with recurrent flare and jet (hereafter flare/jet) activity at the border of an isolated coronal hole situated close to the solar equator. We have focused our study on the solar energetic particle (SEP) event on 17 July 2014, during which both spacecraft detected a similar impulsive and anisotropic energetic electron event suggesting optimal connection of both spacecraft to the parent particle source, despite the large angular separation between the parent flare and the nominal magnetic footpoints on the source surface of STA and STB of 68° and 90°, respectively. Combining the remote-sensing extreme ultraviolet (EUV) observations, in-situ plasma, magnetic field, and energetic particle data we investigated and discuss here the origin and the propagation trajectory of energetic electrons in the solar corona. We find that the energetic electrons in the energy range of 55-195 keV together with the associated EUV jet were injected from the flare site toward the spacecraft's magnetic footpoints and propagate along a strongly non-radial and inclined magnetic field below the source surface. From stereoscopic (EUV) observations we estimated the inclination angle of the jet trajectory and the respective magnetic field of 63° ± 11° relative to the radial direction. We show how the flare accelerated electrons reach very distant longitudes in the heliosphere, when the spacecraft are nominally not connected to the particle source. This example illustrates how ballistic backmapping can occasionally fail to characterize the magnetic connectivity during SEP events. This finding also provides an additional mechanism (one among others