Are Password Management Applications Viable? An Analysis of User Training and Reactions

ERIC Educational Resources Information Center

Ciampa, Mark

2011-01-01

Passwords have the distinction of being the most widely-used form of authentication--and the most vulnerable. With the dramatic increase today in the number of accounts that require passwords, overwhelmed users usually resort to creating weak passwords or reusing the same password for multiple accounts, thus making passwords the weakest link in…

Role of cognitive theory in the study of learning disability in mathematics.

PubMed

Geary, David C

2005-01-01

Gersten, Jordan, and Flojo (in this issue) provide the beginnings of an essential bridge between basic research on mathematical disabilities (MD) in young children and the application of this research for the early identification and remediation of these forms of learning disability. As they acknowledge, the field of MD is in the early stages of development, and thus recommendations regarding identification measures and remedial techniques must be considered preliminary. I discuss the importance of maintaining a tight link between theoretical and empirical research on children's developing numerical, arithmetical, and mathematical competencies and future research on learning disabilities in mathematics. This link will provide the foundation for transforming experimental procedures into assessment measures, understanding the cognitive strengths and weaknesses of children with these forms of learning disability, and developing remedial approaches based on the pattern of cognitive strengths and weaknesses for individual children.

Current-phase relations in low carrier density graphene Josephson junctions

NASA Astrophysics Data System (ADS)

Kratz, Philip; Amet, Francois; Watson, Christopher; Moler, Kathryn; Ke, Chung; Borzenets, Ivan; Watanabe, Kenji; Taniguchi, Takashi; Deacon, Russell; Yamamoto, Michihisa; Bomze, Yuriy; Tarucha, Seigo; Finkelstein, Gleb

Ideal Dirac semimetals have the unique property of being gate tunable to arbitrarily low electron and hole carrier concentrations near the Dirac point, without suffering from conduction channel pinch-off or Fermi level pinning to band edges and deep-level charge traps, which are common in typical semiconductors. SNS junctions, where N is a Dirac semimetal, can provide a versatile platform for studying few-mode superconducting weak links, with potential device applications for superconducting logic and qubits. We will use an inductive readout technique, scanning superconducting quantum interference device (SQUID) magnetometry, to measure the current-phase relations of high-mobility graphene SNS junctions as a function of temperature and carrier density, complementing magnetic Fraunhofer diffraction analysis from transport measurements which previously have assumed sinusoidal current-phase relations for junction Andreev modes. Deviations from sinusoidal behavior convey information about resonant scattering processes, dissipation, and ballistic modes in few-mode superconducting weak links.

Equalizer tap length requirement for mode group delay-compensated fiber link with weakly random mode coupling.

PubMed

Bai, Neng; Li, Guifang

2014-02-24

The equalizer tap length requirement is investigated analytically and numerically for differential modal group delay (DMGD) compensated fiber link with weakly random mode coupling. Each span of the DMGD compensated link comprises multiple pairs of fibers which have opposite signs of DMGD. The result reveals that under weak random mode coupling, the required tap length of the equalizer is proportional to modal group delay of a single DMGD compensated pair, instead of the total modal group delay (MGD) of the entire link. By using small DMGD compensation step sizes, the required tap length (RTL) can be potentially reduced by 2 orders of magnitude.

Biotic indices for assessing the status of coastal waters: a review of strengths and weaknesses.

PubMed

Martínez-Crego, Begoña; Alcoverro, Teresa; Romero, Javier

2010-05-01

Biotic indices have become key assessment tools in most recent national and trans-national policies aimed at improving the quality of coastal waters and the integrity of their associated ecosystems. In this study we analyzed 90 published biotic indices, classified them into four types, and analyzed the strengths and weaknesses of each type in relation to the requirements of these policies. We identified three main type-specific weaknesses. First, the problems of applicability, due to practical and conceptual difficulties, which affect most indices related to ecosystem function. Second, the failure of many indices based on structural attributes of the community (e.g. taxonomic composition) to link deterioration with causative stressors, or to provide an early-detection capacity. Third, the poor relevance to the ecological integrity of indices based on attributes at the sub-individual level (e.g. multi-biomarkers). Additionally, most indices still fail on two further aspects: the broad-scale applicability and the definition of reference conditions. Nowadays, the most promising approach seems to be the aggregation of indices with complementary strengths, and obtained from different biological communities.

Phase Diagram of the Bose Hubbard Model with Weak Links

NASA Astrophysics Data System (ADS)

Hettiarachchilage, Kalani; Rousseau, Valy; Tam, Ka-Ming; Moreno, Juana; Jarrell, Mark; Sheehy, Daniel

2012-02-01

We study the ground state phase diagram of strongly interacting ultracold Bose gas in a one-dimensional optical lattice with a tunable weak link, by means of Quantum Monte Carlo simulation. This model contains an on-site repulsive interaction (U) and two different near-neighbor hopping terms, J and t, for the weak link and the remainder of the chain, respectively. We show that by reducing the strength of J, a novel intermediate phase develops which is compressible and non-superfluid. This novel phase is identified as a Normal Bose Liquid (NBL) which does not appear in the phase diagram of the homogeneous bosonic Hubbard model. Further, we find a linear variation of the phase boundary of Normal Bose Liquid (NBL) to SuperFluid (SF) as a function of the strength of the weak link. These results may provide a new path to design advanced atomtronic devices in the future.

Ultra-weak photon emission in healthy subjects and patients with type 2 diabetes: evidence for a non-invasive diagnostic tool.

PubMed

Yang, Meina; Ding, Wenyu; Liu, Yanli; Fan, Hua; Bajpai, Rajendra P; Fu, Jialei; Pang, Jingxiang; Zhao, Xiaolei; Han, Jinxiang

2017-05-17

Spontaneous ultra-weak photon emission (UPE) is a common phenomenon in biological systems and has been linked to pathological states. Researchers have always considered ultra-weak photon emission a potential non-invasive diagnostic tool, but its application in the medical field is stagnant due to the lack of relevant data for pathological states. Ultra-weak photon signals from five body sites (forehead, neck, heart, stomach, and navel) in fifty patients with type 2 diabetes and sixty age-matched healthy subjects were measured using a moveable whole-body biophoton detection system. Photon signal is measured for 10 min and detected in bins of 50 ms by a photomultiplier with a range of 290-630 nm. Each signal is a time series of 12 000 elements. Various parameters including photon intensity, Q value, squeezed state parameters (|α|, θ, ø, r) and SSI were analyzed. we found significant differences in the abovementioned parameters between groups, and all subjects could be clustered into two groups according to the results obtained by principal component analysis. Methods and results from this study could be useful for constructing a UPE database for a range of diseases, which would promote the application of UPE in clinical diagnosis in the future.

Property Values Associated with the Failure of Individual Links in a System with Multiple Weak and Strong Links.

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

Helton, Jon C.; Brooks, Dusty Marie; Sallaberry, Cedric Jean-Marie.

Representations are developed and illustrated for the distribution of link property values at the time of link failure in the presence of aleatory uncertainty in link properties. The following topics are considered: (i) defining properties for weak links and strong links, (ii) cumulative distribution functions (CDFs) for link failure time, (iii) integral-based derivation of CDFs for link property at time of link failure, (iv) sampling-based approximation of CDFs for link property at time of link failure, (v) verification of integral-based and sampling-based determinations of CDFs for link property at time of link failure, (vi) distributions of link properties conditional onmore » time of link failure, and (vii) equivalence of two different integral-based derivations of CDFs for link property at time of link failure.« less

Ballistic Josephson junctions based on CVD graphene

NASA Astrophysics Data System (ADS)

Li, Tianyi; Gallop, John; Hao, Ling; Romans, Edward

2018-04-01

Josephson junctions with graphene as the weak link between superconductors have been intensely studied in recent years, with respect to both fundamental physics and potential applications. However, most of the previous work was based on mechanically exfoliated graphene, which is not compatible with wafer-scale production. To overcome this limitation, we have used graphene grown by chemical vapour deposition (CVD) as the weak link of Josephson junctions. We demonstrate that very short, wide CVD-graphene-based Josephson junctions with Nb electrodes can work without any undesirable hysteresis in their electrical characteristics from 1.5 K down to a base temperature of 320 mK, and their gate-tuneable critical current shows an ideal Fraunhofer-like interference pattern in a perpendicular magnetic field. Furthermore, for our shortest junctions (50 nm in length), we find that the normal state resistance oscillates with the gate voltage, consistent with the junctions being in the ballistic regime, a feature not previously observed in CVD-graphene-based Josephson junctions.

Manipulation of in vitro collagen matrix architecture for scaffolds of improved physiological relevance

NASA Astrophysics Data System (ADS)

Hapach, Lauren A.; VanderBurgh, Jacob A.; Miller, Joseph P.; Reinhart-King, Cynthia A.

2015-12-01

Type I collagen is a versatile biomaterial that is widely used in medical applications due to its weak antigenicity, robust biocompatibility, and its ability to be modified for a wide array of applications. As such, collagen has become a major component of many tissue engineering scaffolds, drug delivery platforms, and substrates for in vitro cell culture. In these applications, collagen constructs are fabricated to recapitulate a diverse set of conditions. Collagen fibrils can be aligned during or post-fabrication, cross-linked via numerous techniques, polymerized to create various fibril sizes and densities, and copolymerized into a wide array of composite scaffolds. Here, we review approaches that have been used to tune collagen to better recapitulate physiological environments for use in tissue engineering applications and studies of basic cell behavior. We discuss techniques to control fibril alignment, methods for cross-linking collagen constructs to modulate stiffness, and composite collagen constructs to better mimic physiological extracellular matrix.

High-T(sub c) Edge-geometry SNS Weak Links on Silicon-on-sapphire Substrates

NASA Technical Reports Server (NTRS)

Hunt, B.; Foote, M.; Pike, W.; Barner, J.; Vasquez, R.

1994-01-01

High-quality superconductor/normal-metal/superconductor(SNS) edge-geometry weak links have been produced on silicon-on-sapphire (SOS) substrates using a new SrTiO(sub 3)/'seed layer'/cubic-zirconia (YS2) buffer system.

Growth, patterning, and weak-link fabrication of superconducting YBa2Cu3O(7-x) thin films

NASA Astrophysics Data System (ADS)

Hilton, G. C.; Harris, E. B.; van Harlingen, D. J.

1988-09-01

Thin films of the high-temperature superconducting ceramic oxides have been grown, and techniques for fabricating weak-link structures have been investigated. Films of YBa2Cu3O(7-x) grown on SrTiO3 by a combination of dc magnetron sputtering and thermal evaporation from the three sources have been patterned into microbridges with widths down to 2 microns. Evidence is found that the bridges behave as arrays of Josephson-coupled superconducting islands. Further weak-link behavior is induced by in situ modification of the coupling by ion milling through the bridge.

Shifting stroke care from the hospital to the nursing home: explaining the outcomes of a Dutch case.

PubMed

van Raak, Arno; Groothuis, Siebren; van der Aa, Robert; Limburg, Martien; Vos, Leti

2010-12-01

Supply chains can contribute to better care for stroke patients and more efficiency. However, such outcomes are hampered when links in the chain are weak. The article aims to further the knowledge about the causes and possible improvements of weak links thereby using theory about rules for action and routines (action patterns). We executed a single case study of a chain of service delivery to stroke patients by a university hospital and a nursing home in the city of Maastricht, the Netherlands. Methods included document study, interviews, observations, process mapping, use of data matrices and performance of t-tests. In the case, the care delivery process in the chain was redesigned to improve the flow of patients and to reduce the length of hospital stay. Length of stay was reduced. However, transfer of patients from the hospital to the nursing home was hampered. At this weak link in the chain, the redesign clashed with the routines of hospital paramedics who did not want to work according to the redesign. The applied theory is useful to understand why a link in a supply chain is weak. Negotiations can be used to strengthen a link. © 2010 Blackwell Publishing Ltd.

Phase slips in superconducting weak links

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

Kimmel, Gregory; Glatz, Andreas; Aranson, Igor S.

2017-01-01

Superconducting vortices and phase slips are primary mechanisms of dissipation in superconducting, superfluid, and cold-atom systems. While the dynamics of vortices is fairly well described, phase slips occurring in quasi-one- dimensional superconducting wires still elude understanding. The main reason is that phase slips are strongly nonlinear time-dependent phenomena that cannot be cast in terms of small perturbations of the superconducting state. Here we study phase slips occurring in superconducting weak links. Thanks to partial suppression of superconductivity in weak links, we employ a weakly nonlinear approximation for dynamic phase slips. This approximation is not valid for homogeneous superconducting wires andmore » slabs. Using the numerical solution of the time-dependent Ginzburg-Landau equation and bifurcation analysis of stationary solutions, we show that the onset of phase slips occurs via an infinite period bifurcation, which is manifested in a specific voltage-current dependence. Our analytical results are in good agreement with simulations.« less

Current driven transition from Abrikosov-Josephson to Josephson-like vortex in mesoscopic lateral S/S’/S superconducting weak links

PubMed Central

Carapella, G.; Sabatino, P.; Barone, C.; Pagano, S.; Gombos, M.

2016-01-01

Vortices are topological defects accounting for many important effects in superconductivity, superfluidity, and magnetism. Here we address the stability of a small number of such excitations driven by strong external forces. We focus on Abrikosov-Josephson vortex that appears in lateral superconducting S/S’/S weak links with suppressed superconductivity in S’. In such a system the vortex is nucleated and confined in the narrow S’ region by means of a small magnetic field and moves under the effect of a force proportional to an applied electrical current with a velocity proportional to the measured voltage. Our numerical simulations show that when a slow moving Abrikosov-Josephson vortex is driven by a strong constant current it becomes unstable with respect to a faster moving excitation: the Josephon-like vortex. Such a current-driven transition explains the structured dissipative branches that we observe in the voltage-current curve of the weak link. When vortex matter is strongly confined phenomena as magnetoresistance oscillations and reentrance of superconductivity can possibly occur. We experimentally observe these phenomena in our weak links. PMID:27752137

Organically linked iron oxide nanoparticle supercrystals with exceptional isotropic mechanical properties.

PubMed

Dreyer, Axel; Feld, Artur; Kornowski, Andreas; Yilmaz, Ezgi D; Noei, Heshmat; Meyer, Andreas; Krekeler, Tobias; Jiao, Chengge; Stierle, Andreas; Abetz, Volker; Weller, Horst; Schneider, Gerold A

2016-05-01

It is commonly accepted that the combination of the anisotropic shape and nanoscale dimensions of the mineral constituents of natural biological composites underlies their superior mechanical properties when compared to those of their rather weak mineral and organic constituents. Here, we show that the self-assembly of nearly spherical iron oxide nanoparticles in supercrystals linked together by a thermally induced crosslinking reaction of oleic acid molecules leads to a nanocomposite with exceptional bending modulus of 114 GPa, hardness of up to 4 GPa and strength of up to 630 MPa. By using a nanomechanical model, we determined that these exceptional mechanical properties are dominated by the covalent backbone of the linked organic molecules. Because oleic acid has been broadly used as nanoparticle ligand, our crosslinking approach should be applicable to a large variety of nanoparticle systems.

Quantitative analysis of glycoprotein glycans.

PubMed

Orlando, Ron

2013-01-01

The ability to quantitatively determine changes in the N- and O-linked glycans is an essential component of comparative glycomics. Multiple strategies are available to by which this can be accomplished, including; both label free approaches and isotopic labeling strategies. The focus of this chapter is to describe each of these approaches while providing insight into their strengths and weaknesses, so that glycomic investigators can make an educated choice of the strategy that is best suited for their particular application.

Weak- versus strong-disorder superfluid—Bose glass transition in one dimension

NASA Astrophysics Data System (ADS)

Doggen, Elmer V. H.; Lemarié, Gabriel; Capponi, Sylvain; Laflorencie, Nicolas

2017-11-01

Using large-scale simulations based on matrix product state and quantum Monte Carlo techniques, we study the superfluid to Bose glass transition for one-dimensional attractive hard-core bosons at zero temperature, across the full regime from weak to strong disorder. As a function of interaction and disorder strength, we identify a Berezinskii-Kosterlitz-Thouless critical line with two different regimes. At small attraction where critical disorder is weak compared to the bandwidth, the critical Luttinger parameter Kc takes its universal Giamarchi-Schulz value Kc=3 /2 . Conversely, a nonuniversal Kc>3 /2 emerges for stronger attraction where weak-link physics is relevant. In this strong-disorder regime, the transition is characterized by self-similar power-law-distributed weak links with a continuously varying characteristic exponent α .

Linking Theory of Mind and Central Coherence Bias in Autism and in the General Population.

ERIC Educational Resources Information Center

Jarrold, Christopher; Butler, David W.; Cottington, Emily M.; Jimenez, Flora

2000-01-01

Three experiments investigated whether theory-of-mind deficits and weak central coherence might be functionally related. Found that theory-of-mind performance was inversely related to a measure of central coherence bias in the general population. Poor theory-of-mind performance was linked to weak central coherence among children with typical…

Weak Links: Stabilizers of Complex Systems from Proteins to Social Networks

NASA Astrophysics Data System (ADS)

Csermely, Peter

Why do women stabilize our societies? Why can we enjoy and understand Shakespeare? Why are fruitflies uniform? Why do omnivorous eating habits aid our survival? Why is Mona Lisa's smile beautiful? -- Is there any answer to these questions? This book shows that the statement: "weak links stabilize complex systems" holds the answers to all of the surprising questions above. The author (recipientof several distinguished science communication prizes) uses weak (low affinity, low probability) interactions as a thread to introduce a vast varietyof networks from proteins to ecosystems.

Fabrication of high T(sub c) superconductor thin film devices: Center director's discretionary fund

NASA Technical Reports Server (NTRS)

Sisk, R. C.

1992-01-01

This report describes a technique for fabricating superconducting weak link devices with micron-sized geometries etched in laser ablated Y1Ba2Cu3O(x) (YBCO) thin films. Careful placement of the weak link over naturally occurring grain boundaries exhibited in some YBCO thin films produces Superconducting Quantum Interference Devices (SQUID's) operating at 77 K.

The Weak Link HP-41C hand-held calculator program

Treesearch

Ross A. Phillips; Penn A. Peters; Gary D. Falk

1982-01-01

The Weak Link hand-held calculator program (HP-41C) quickly analyzes a system for logging production and costs. The production equations model conventional chain saw, skidder, loader, and tandemaxle truck operations in eastern mountain areas. Production of each function of the logging system may be determined so that the system may be balanced for minimum cost. The...

Vortex instability in turbulent free-space propagation

NASA Astrophysics Data System (ADS)

Lavery, Martin P. J.

2018-04-01

The spatial structuring of optical fields is integral within many next generation optical metrology and communication techniques. A verifiable physical model of the propagation of these optical fields in a turbulent environment is important for developing effective mitigation techniques for the modal degradation that occurs in a free-space link. We present a method to simulate this modal degradation that agrees with recently reported experimental findings. A 1.5 km free-space link is emulated by decomposing the optical turbulence that accumulates over a long distance link, into many, weakly perturbing steps of 10 m. This simulation shows that the high-order vortex at the centre of the helical phase profiles in modes that carry orbital angular momentum of | {\\ell }| ≥slant 2{\\hslash } are unstable and fracture into many vortices when they propagate over the link. This splitting presents issues for the application of turbulence mitigation techniques. The usefulness of pre-correction, post-correction, and complex field conjugation techniques are discussed.

Weak reversible cross links may decrease the strength of aligned fiber bundles.

PubMed

Nabavi, S Soran; Hartmann, Markus A

2016-02-21

Reversible cross-linking is an effective strategy to specifically tailor the mechanical properties of polymeric materials that can be found in a variety of biological as well as man-made materials. Using a simple model in this paper the influence of weak, reversible cross-links on the mechanical properties of aligned fiber bundles is investigated. Special emphasis in this analysis is put on the strength of the investigated structures. Using Monte Carlo methods two topologies of cross-links exceeding the strength of the covalent backbone are studied. Most surprisingly only two cross-links are sufficient to break the backbone of a multi chain system, resulting in a reduced strength of the material. The found effect crucially depends on the ratio of inter- to intra-chain cross-links and, thus, on the grafting density that determines this ratio.

Imaging of current density distributions with a Nb weak-link scanning nano-SQUID microscope

PubMed Central

Shibata, Yusuke; Nomura, Shintaro; Kashiwaya, Hiromi; Kashiwaya, Satoshi; Ishiguro, Ryosuke; Takayanagi, Hideaki

2015-01-01

Superconducting quantum interference devices (SQUIDs) are accepted as one of the highest magnetic field sensitive probes. There are increasing demands to image local magnetic fields to explore spin properties and current density distributions in a two-dimensional layer of semiconductors or superconductors. Nano-SQUIDs have recently attracting much interest for high spatial resolution measurements in nanometer-scale samples. Whereas weak-link Dayem Josephson junction nano-SQUIDs are suitable to miniaturization, hysteresis in current-voltage (I-V) characteristics that is often observed in Dayem Josephson junction is not desirable for a scanning microscope. Here we report on our development of a weak-link nano-SQUIDs scanning microscope with small hysteresis in I-V curve and on reconstructions of two-dimensional current density vector in two-dimensional electron gas from measured magnetic field. PMID:26459874

Imaging of current density distributions with a Nb weak-link scanning nano-SQUID microscope

NASA Astrophysics Data System (ADS)

Shibata, Yusuke; Nomura, Shintaro; Kashiwaya, Hiromi; Kashiwaya, Satoshi; Ishiguro, Ryosuke; Takayanagi, Hideaki

2015-10-01

Superconducting quantum interference devices (SQUIDs) are accepted as one of the highest magnetic field sensitive probes. There are increasing demands to image local magnetic fields to explore spin properties and current density distributions in a two-dimensional layer of semiconductors or superconductors. Nano-SQUIDs have recently attracting much interest for high spatial resolution measurements in nanometer-scale samples. Whereas weak-link Dayem Josephson junction nano-SQUIDs are suitable to miniaturization, hysteresis in current-voltage (I-V) characteristics that is often observed in Dayem Josephson junction is not desirable for a scanning microscope. Here we report on our development of a weak-link nano-SQUIDs scanning microscope with small hysteresis in I-V curve and on reconstructions of two-dimensional current density vector in two-dimensional electron gas from measured magnetic field.

Implications of Weak Link Effects on Thermal Characteristics of Transition-Edge Sensors

NASA Technical Reports Server (NTRS)

Bailey, Catherine

2011-01-01

Weak link behavior in transition-edge sensor (TES) devices creates the need for a more careful characterization of a device's thermal characteristics through its transition. This is particularly true for small TESs where a small change in the measurement current results in large changes in temperature. A highly current-dependent transition shape makes accurate thermal characterization of the TES parameters through the transition challenging. To accurately interpret measurements, especially complex impedance, it is crucial to know the temperature-dependent thermal conductance, G(T), and heat capacity, C(T), at each point through the transition. We will present data illustrating these effects and discuss how we overcome the challenges that are present in accurately determining G and T from IV curves. We will also show how these weak link effects vary with TES size.

Adaptive nodes enrich nonlinear cooperative learning beyond traditional adaptation by links.

PubMed

Sardi, Shira; Vardi, Roni; Goldental, Amir; Sheinin, Anton; Uzan, Herut; Kanter, Ido

2018-03-23

Physical models typically assume time-independent interactions, whereas neural networks and machine learning incorporate interactions that function as adjustable parameters. Here we demonstrate a new type of abundant cooperative nonlinear dynamics where learning is attributed solely to the nodes, instead of the network links which their number is significantly larger. The nodal, neuronal, fast adaptation follows its relative anisotropic (dendritic) input timings, as indicated experimentally, similarly to the slow learning mechanism currently attributed to the links, synapses. It represents a non-local learning rule, where effectively many incoming links to a node concurrently undergo the same adaptation. The network dynamics is now counterintuitively governed by the weak links, which previously were assumed to be insignificant. This cooperative nonlinear dynamic adaptation presents a self-controlled mechanism to prevent divergence or vanishing of the learning parameters, as opposed to learning by links, and also supports self-oscillations of the effective learning parameters. It hints on a hierarchical computational complexity of nodes, following their number of anisotropic inputs and opens new horizons for advanced deep learning algorithms and artificial intelligence based applications, as well as a new mechanism for enhanced and fast learning by neural networks.

Employment of Gibbs-Donnan-based concepts for interpretation of the properties of linear polyelectrolyte solutions

USGS Publications Warehouse

Marinsky, J.A.; Reddy, M.M.

1991-01-01

Earlier research has shown that the acid dissociation and metal ion complexation equilibria of linear, weak-acid polyelectrolytes and their cross-linked gel analogues are similarly sensitive to the counterion concentration levels of their solutions. Gibbs-Donnan-based concepts, applicable to the gel, are equally applicable to the linear polyelectrolyte for the accommodation of this sensitivity to ionic strength. This result is presumed to indicate that the linear polyelectrolyte in solution develops counterion-concentrating regions that closely resemble the gel phase of their analogues. Advantage has been taken of this description of linear polyelectrolytes to estimate the solvent uptake by these regions. ?? 1991 American Chemical Society.

Design of weak link channel-cut crystals for fast QEXAFS monochromators

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

Polheim, O. von, E-mail: vonpolheim@uni-wuppertal.de; Müller, O.; Lützenkirchen-Hecht, D.

2016-07-27

A weak link channel-cut crystal, optimized for dedicated Quick EXAFS monochromators and measurements, was designed using finite element analysis. This channel-cut crystal offers precise detuning capabilities to enable suppression of higher harmonics in the virtually monochromatic beam. It was optimized to keep the detuning stable, withstanding the mechanical load, which occurs during oscillations with up to 50 Hz. First tests at DELTA (Dortmund, Germany), proved the design.

Transfusion strategy for weak D type 4.0 based on RHD alleles and RH haplotypes in Tunisia

PubMed Central

Ouchari, Mouna; Srivastava, Kshitij; Romdhane, Houda; Yacoub, Saloua Jemni; Flegel, Willy Albert

2017-01-01

Background With more than 460 RHD alleles, this gene is the most complex and polymorphic among all blood group systems. The Tunisian population has the largest known prevalence of weak D type 4.0 alleles, occurring in 1 of 105 RH haplotypes. We aimed to establish a rationale for the transfusion strategy of weak D type 4.0 in Tunisia. Study design and methods Donors were randomly screened for the serological weak D phenotype. The RHD coding sequence and parts of the introns were sequenced. To establish the RH haplotype, the RHCE gene was tested for characteristic single nucleotide positions. Results We determined all RHD alleles and the RH haplotypes coding for the serologic weak D phenotype among 13,431 Tunisian donations. A serologic weak D phenotype was found in 67 individuals (0.50%). Among them, 60 carried a weak D type 4 allele: 53 weak D type 4.0, 6 weak D type 4.2.2 (DAR), and 1 weak D type 4.1. Another 4 donors had 1 variant allele each: DVII, weak D type 1, weak D type 3, and weak D type 100, while 3 donors showed a normal RHD sequence. The weak D type 4.0 was most often linked to RHCE*ceVS.04.01, weak D type 4.2.2 to RHCE*ceAR, and weak D type 4.1 to RHCE*ceVS.02, while the other RHD alleles were linked to one of the common RHCE alleles. Conclusions Among the weak D phenotypes in Tunisia, no novel RHD allele was found and almost 90% were caused by alleles of the weak D type 4 cluster, of which 88% represented the weak D type 4.0 allele. Based on established RH haplotypes for variant RHD and RHCE alleles and the lack of adverse clinical reports, we recommend D positive transfusions for patients with weak D type 4.0 in Tunisia. PMID:29193104

Transfusion strategy for weak D Type 4.0 based on RHD alleles and RH haplotypes in Tunisia.

PubMed

Ouchari, Mouna; Srivastava, Kshitij; Romdhane, Houda; Jemni Yacoub, Saloua; Flegel, Willy Albert

2018-02-01

With more than 460 RHD alleles, this gene is the most complex and polymorphic among all blood group systems. The Tunisian population has the largest known prevalence of weak D Type 4.0 alleles, occurring in one of 105 RH haplotypes. We aimed to establish a rationale for the transfusion strategy of weak D Type 4.0 in Tunisia. Donors were randomly screened for the serologic weak D phenotype. The RHD coding sequence and parts of the introns were sequenced. To establish the RH haplotype, the RHCE gene was tested for characteristic single-nucleotide positions. We determined all RHD alleles and the RH haplotypes coding for the serologic weak D phenotype among 13,431 Tunisian donations. A serologic weak D phenotype was found in 67 individuals (0.50%). Among them, 60 carried a weak D Type 4 allele: 53 weak D Type 4.0, six weak D Type 4.2.2 (DAR), and one weak D Type 4.1. An additional four donors had one variant allele each: DVII, weak D Type 1, weak D Type 3, and weak D type 100, while three donors showed a normal RHD sequence. The weak D Type 4.0 was most often linked to RHCE*ceVS.04.01, weak D Type 4.2.2 to RHCE*ceAR, and weak D Type 4.1 to RHCE*ceVS.02, while the other RHD alleles were linked to one of the common RHCE alleles. Among the weak D phenotypes in Tunisia, no novel RHD allele was found and almost 90% were caused by alleles of the weak D Type 4 cluster, of which 88% represented the weak D Type 4.0 allele. Based on established RH haplotypes for variant RHD and RHCE alleles and the lack of adverse clinical reports, we recommend D+ transfusions for patients with weak D Type 4.0 in Tunisia. © 2017 AABB.

Linking Research, Extension and Education: Why Is the Problem So Persistent and Pervasive?

ERIC Educational Resources Information Center

Van Crowder, L.; Anderson, J.

1997-01-01

Weak links among research, education, and extension often result from their informal nature, national agriculture policy environment, and funding shortages. An integrative systems approach can strengthen links to improve agriculture technology systems. (SK)

7-Meth­oxy­indan-1-one

PubMed Central

Chang, Yuan Jay; Chen, Kew-Yu

2012-01-01

In the title compound, C10H10O2, the 1-indanone unit is essentially planar (r.m.s. deviation = 0.028 Å). In the crystal, molecules are linked via C—H⋯O hydrogen bonds, forming layers lying parallel to the ab plane. This two-dimensional structure is stabilized by a weak C—H⋯π inter­action. A second weak C—H⋯π inter­action links the layers, forming a three-dimensional structure. PMID:23284398

Scintillation index and performance analysis of wireless optical links over non-Kolmogorov weak turbulence based on generalized atmospheric spectral model.

PubMed

Cang, Ji; Liu, Xu

2011-09-26

Based on the generalized spectral model for non-Kolmogorov atmospheric turbulence, analytic expressions of the scintillation index (SI) are derived for plane, spherical optical waves and a partially coherent Gaussian beam propagating through non-Kolmogorov turbulence horizontally in the weak fluctuation regime. The new expressions relate the SI to the finite turbulence inner and outer scales, spatial coherence of the source and spectral power-law and then used to analyze the effects of atmospheric condition and link length on the performance of wireless optical communication links. © 2011 Optical Society of America

On the sensitivity of annual streamflow to air temperature

USGS Publications Warehouse

Milly, Paul C.D.; Kam, Jonghun; Dunne, Krista A.

2018-01-01

Although interannual streamflow variability is primarily a result of precipitation variability, temperature also plays a role. The relative weakness of the temperature effect at the annual time scale hinders understanding, but may belie substantial importance on climatic time scales. Here we develop and evaluate a simple theory relating variations of streamflow and evapotranspiration (E) to those of precipitation (P) and temperature. The theory is based on extensions of the Budyko water‐balance hypothesis, the Priestley‐Taylor theory for potential evapotranspiration ( ), and a linear model of interannual basin storage. The theory implies that the temperature affects streamflow by modifying evapotranspiration through a Clausius‐Clapeyron‐like relation and through the sensitivity of net radiation to temperature. We apply and test (1) a previously introduced “strong” extension of the Budyko hypothesis, which requires that the function linking temporal variations of the evapotranspiration ratio (E/P) and the index of dryness ( /P) at an annual time scale is identical to that linking interbasin variations of the corresponding long‐term means, and (2) a “weak” extension, which requires only that the annual evapotranspiration ratio depends uniquely on the annual index of dryness, and that the form of that dependence need not be known a priori nor be identical across basins. In application of the weak extension, the readily observed sensitivity of streamflow to precipitation contains crucial information about the sensitivity to potential evapotranspiration and, thence, to temperature. Implementation of the strong extension is problematic, whereas the weak extension appears to capture essential controls of the temperature effect efficiently.

Tailoring chain length and cross-link density in dielectric elastomer toward enhanced actuation strain

NASA Astrophysics Data System (ADS)

Zhang, Quan-Ping; Liu, Jun-Hua; Liu, Hai-Dong; Jia, Fei; Zhou, Yuan-Lin; Zheng, Jian

2017-10-01

Adding ceramic or conductive fillers into polymers for increasing permittivity is a direct and effective approach to enhance the actuation strain of dielectric elastomer actuators (DEAs). Unfortunately, the major dielectric loss caused by weak interfaces potentially harms the electro-mechanical stability and lifetime of DEAs. Here, we construct a desired macromolecular network with a long chain length and low cross-link density to reduce the elastic modulus of silicone elastomers. Selecting a high molecular weight of polymethylvinylsiloxane and a low dose of the cross-linker leads the soft but tough networks with rich entanglements, poor cross-links, and a low amount of defects. Then, a ductile material with low elastic modulus but high elongation at break is obtained. It accounts for much more excellent actuation strain of Hl in comparison to that of the other silicone elastomers. Importantly, without other fillers, the ultralow dielectric loss, conductivity, and firm networks possibly promote the electro-mechanical stability and lifetime for the DEA application.

Evaluation, development, and characterization of superconducting materials for space applications

NASA Technical Reports Server (NTRS)

Thorpe, Arthur N.

1990-01-01

The anisotropic electromagnetic features of a grain-aligned YBa2Cu3O(x) bulk sample derived from a process of long-time partial melt growth were investigated by the measurements of direct current magnetization (at 77 K) and alternating current susceptibility as a function of temperature, with the fields applied parallel and perpendicular to the c axis, respectively. The extended Bean model was further studied and applied to explain the experimental results. Upon comparison of the grain-aligned sample with pure single crystal materials, it is concluded that because of the existence of more effective pinning sites in the grain-aligned sample, not only its critical current density perpendicular to the c axis is improved, but the one parallel to the c axis is improved even more significantly. The anisotropy in the critical current densities in the grain-aligned sample at 77 K is at least one to two orders of magnitude smaller than in the pure single crystal. The measurement of anisotropy of alternating current susceptibility as a function of temperature, especially its imaginary part, shows that there are still some residues of interlayer weak links in the grain-aligned samples, but they are quite different from and far less serious than the weak links in the sintered sample.

Dynamic properties of molecular motors in burnt-bridge models

NASA Astrophysics Data System (ADS)

Artyomov, Maxim N.; Morozov, Alexander Yu; Pronina, Ekaterina; Kolomeisky, Anatoly B.

2007-08-01

Dynamic properties of molecular motors that fuel their motion by actively interacting with underlying molecular tracks are studied theoretically via discrete-state stochastic 'burnt-bridge' models. The transport of the particles is viewed as an effective diffusion along one-dimensional lattices with periodically distributed weak links. When an unbiased random walker passes the weak link it can be destroyed ('burned') with probability p, providing a bias in the motion of the molecular motor. We present a theoretical approach that allows one to calculate exactly all dynamic properties of motor proteins, such as velocity and dispersion, under general conditions. It is found that dispersion is a decreasing function of the concentration of bridges, while the dependence of dispersion on the burning probability is more complex. Our calculations also show a gap in dispersion for very low concentrations of weak links or for very low burning probabilities which indicates a dynamic phase transition between unbiased and biased diffusion regimes. Theoretical findings are supported by Monte Carlo computer simulations.

Controlling Hysteresis in Superconducting Weak Links and μ-Superconducting Quantum Interference Devices

NASA Astrophysics Data System (ADS)

Kumar, Nikhil; Winkelmann, C. B.; Biswas, Sourav; Courtois, H.; Gupta, Anjan K.

We have fabricated and studied the current-voltage characteristics of a number of niobium film based weak-link devices and μ-SQUIDs showing a critical current and two re-trapping currents. We have proposed a new understanding for the re-trapping currents in terms of thermal instabilities in different portions of the device. We also find that the superconducting proximity effect and the phase-slip processes play an important role in dictating the temperature dependence of the critical current in the non-hysteretic regime. The proximity effect helps in widening the temperature range of hysteresis-free characteristics. Finally we demonstrate control on temperature-range with hysteresis-free characteristics in two ways: 1) By using a parallel shunt resistor in close vicinity of the device, and 2) by reducing the weak-link width. Thus we get non-hysteretic behavior down to 1.3 K temperature in some of the studied devices. We acknowledge the financial support from CSIR, India as well as CNRS-Institute Neel, Grenoble, France.

Implications of Weak Link Effects on Thermal Characteristics of Transition-Edge Sensors

NASA Technical Reports Server (NTRS)

Bailey, C. N.; Adams, J. S.; Bandler, S. R.; Brekosky, R. P.; Chevenak, J. A.; Eckart, M. E.; Finkbeiner, F. M.; Kelley, R. L.; Kally, D. P.; Kilbourne, C. A.;

Weak gauge boson radiation in parton showers

NASA Astrophysics Data System (ADS)

Christiansen, Jesper R.; Sjöstrand, Torbjörn

2014-04-01

The emission of W and Z gauge bosons off quarks is included in a traditional QCD + QED shower. The unitarity of the shower algorithm links the real radiation of the weak gauge bosons to the negative weak virtual corrections. The shower evolution process leads to a competition between QCD, QED and weak radiation, and allows for W and Z boson production inside jets. Various effects on LHC physics are studied, both at low and high transverse momenta, and effects at higher-energy hadron colliders are outlined.

The effect of riboflavin/UVA cross-linking on anti-degeneration and promoting angiogenic capability of decellularized liver matrix.

PubMed

Xiang, Junxi; Liu, Peng; Zheng, Xinglong; Dong, Dinghui; Fan, Shujuan; Dong, Jian; Zhang, Xufeng; Liu, Xuemin; Wang, Bo; Lv, Yi

2017-10-01

Weak mechanical property and unstable degradation rate limited the application of decellularized liver matrix in tissue engineering. The aim of this study was to explore a new method for improving the mechanical properties, anti-degeneration and angiogenic capability of decellularized liver matrix. This was achieved by a novel approach using riboflavin/ultraviolet A treatment to induce collagen cross-linking of decellularized matrix. Histological staining and scanning electron microscope showed that the diameter of cross-linked fibers significantly increased compared with the control group. The average peak load and Young's modulus of decellularized matrix were obviously improved after cross-linking. Then we implanted the modified matrix into the rat hepatic injury model to test the anti-degeneration and angiogenic capability of riboflavin/UVA cross-linked decellularized liver scaffolds in vivo. The results indicated that cross-linked scaffolds degrade more slowly than those in the control group. In the experiment group, average microvessel density in the implanted matrix was higher than that in the control group since the first week after implantation. In conclusion, we initiated the method to improve the biomechanical properties of decellularized liver scaffolds by riboflavin/UVA cross-linking, and more importantly, its improvement on anti-degeneration and angiogenesis was identified. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2662-2669, 2017. © 2017 Wiley Periodicals, Inc.

Bis(tetra­phenyl­phospho­nium) tetra­chlorido­cobaltate(II)

PubMed Central

Ouahida, Zeghouan; Hadjadj, Nasreddine; Guenifa, Fatiha; Bendjeddou, Lamia; Merazig, Hocine

2014-01-01

The title compound, (C24H20P)2[CoCl4], was prepared under hydro­thermal conditions. In the crystal, the tetra­phenyl­phospho­nium cations are linked by pairs of weak C—H⋯π inter­actions into supra­molecular dimers; the CoII cations lie on twofold rotation axes and the tetra­hedral [CoCl4]2− anions are linked with the tetra­phenyl­phospho­nium cations via weak C—H⋯Cl hydrogen bonds. PMID:24940211

Artificial in-plane ordering of textured YBa2Cu3O(7-x) films deposited on polycrystalline yttria-stabilized zirconia substrates

NASA Astrophysics Data System (ADS)

Harshavardhan, K. S.; Rajeswari, M.; Hwang, D. M.; Chen, C. Y.; Sands, T. D.; Venkatesan, T.; Tkaczyk, J. E.; Lay, K. W.; Safari, A.; Johnson, L.

1992-12-01

Anisotropic surface texturing of the polycrystalline yttria-stabilized zirconia substrates, prior to YBa2Cu3O(7-x) film deposition, is shown to promote in-plane (basal plane) ordering of the film growth in addition to the c-axis texturing. The Jc's of the films in the weak-link-dominated low-field regime are enhanced considerably, and this result is attributed to the reduction of weak links resulting from a reduction in the number of in-plane large-angle grain boundaries.

Weak Interactions Group

Science.gov Websites

Weak Interactions Group UC Berkeley UC Berkeley Physics Lawrence Berkeley Lab Nuclear Science Division at LBL Physics Division at LBL Phonebook A-Z Index Navigation Home Members Research Projects CUORE Design Concept Berkeley Projects People Publications Contact Links KamLAND Physics Impact Neutrino

MUSIC algorithm for location searching of dielectric anomalies from S-parameters using microwave imaging

NASA Astrophysics Data System (ADS)

Park, Won-Kwang; Kim, Hwa Pyung; Lee, Kwang-Jae; Son, Seong-Ho

2017-11-01

Motivated by the biomedical engineering used in early-stage breast cancer detection, we investigated the use of MUltiple SIgnal Classification (MUSIC) algorithm for location searching of small anomalies using S-parameters. We considered the application of MUSIC to functional imaging where a small number of dipole antennas are used. Our approach is based on the application of Born approximation or physical factorization. We analyzed cases in which the anomaly is respectively small and large in relation to the wavelength, and the structure of the left-singular vectors is linked to the nonzero singular values of a Multi-Static Response (MSR) matrix whose elements are the S-parameters. Using simulations, we demonstrated the strengths and weaknesses of the MUSIC algorithm in detecting both small and extended anomalies.

Progress towards the development of a source of entangled photons for Space

NASA Astrophysics Data System (ADS)

Fedrizzi, Alessandro; Jennewein, Thomas; Ursin, Rupert; Zeilinger, Anton

2007-03-01

Quantum entanglement offers exciting applications like quantum computing, quantum teleportation and quantum cryptography. Ground based quantum communication schemes in optical fibres however are limited to a distance of the order of ˜100 km. In order to extend this limit to a global scale we are working on the realization of an entanglement-based quantum communication transceiver for space deployment. Here we report on a compact, extremely bright source for polarization entangled photons meeting the scientific requirements for a potential space to ground optical link. The pair production rate exceeds 4*10̂6 pairs/s at just 20mW of laser diode pump power. Furthermore, we will present the results of various experiments proving the feasibility of quantum information in space, including a weak coherent pulse single-photon downlink from a LEO satellite and the distribution of entanglement over a 144km free space link, using ESAs optical ground station.

Inverse Jacobi multiplier as a link between conservative systems and Poisson structures

NASA Astrophysics Data System (ADS)

García, Isaac A.; Hernández-Bermejo, Benito

2017-08-01

Some aspects of the relationship between conservativeness of a dynamical system (namely the preservation of a finite measure) and the existence of a Poisson structure for that system are analyzed. From the local point of view, due to the flow-box theorem we restrict ourselves to neighborhoods of singularities. In this sense, we characterize Poisson structures around the typical zero-Hopf singularity in dimension 3 under the assumption of having a local analytic first integral with non-vanishing first jet by connecting with the classical Poincaré center problem. From the global point of view, we connect the property of being strictly conservative (the invariant measure must be positive) with the existence of a Poisson structure depending on the phase space dimension. Finally, weak conservativeness in dimension two is introduced by the extension of inverse Jacobi multipliers as weak solutions of its defining partial differential equation and some of its applications are developed. Examples including Lotka-Volterra systems, quadratic isochronous centers, and non-smooth oscillators are provided.

Semi-dwarfism and lodging tolerance in tef (Eragrostis tef) is linked to a mutation in the α-Tubulin 1 gene

PubMed Central

Jöst, Moritz; Esfeld, Korinna; Burian, Agata; Cannarozzi, Gina; Chanyalew, Solomon; Kuhlemeier, Cris; Assefa, Kebebew; Tadele, Zerihun

2015-01-01

Genetic improvement of native crops is a new and promising strategy to combat hunger in the developing world. Tef is the major staple food crop for approximately 50 million people in Ethiopia. As an indigenous cereal, it is well adapted to diverse climatic and soil conditions; however, its productivity is extremely low mainly due to susceptibility to lodging. Tef has a tall and weak stem, liable to lodge (or fall over), which is aggravated by wind, rain, or application of nitrogen fertilizer. To circumvent this problem, the first semi-dwarf lodging-tolerant tef line, called kegne, was developed from an ethyl methanesulphonate (EMS)-mutagenized population. The response of kegne to microtubule-depolymerizing and -stabilizing drugs, as well as subsequent gene sequencing and segregation analysis, suggests that a defect in the α-Tubulin gene is functionally and genetically tightly linked to the kegne phenotype. In diploid species such as rice, homozygous mutations in α-Tubulin genes result in extreme dwarfism and weak stems. In the allotetraploid tef, only one homeologue is mutated, and the presence of the second intact α-Tubulin gene copy confers the agriculturally beneficial semi-dwarf and lodging-tolerant phenotype. Introgression of kegne into locally adapted and popular tef cultivars in Ethiopia will increase the lodging tolerance in the tef germplasm and, as a result, will improve the productivity of this valuable crop. PMID:25399019

Exergy analysis on industrial boiler energy conservation and emission evaluation applications

NASA Astrophysics Data System (ADS)

Li, Henan

2017-06-01

Industrial boiler is one of the most energy-consuming equipments in china, the annual consumption of energy accounts for about one-third of the national energy consumption. Industrial boilers in service at present have several severe problems such as small capacity, low efficiency, high energy consumption and causing severe pollution on environment. In recent years, our country in the big scope, long time serious fog weather, with coal-fired industrial boilers is closely related to the regional characteristics of high strength and low emissions [1]. The energy-efficient and emission-reducing of industry boiler is of great significance to improve China’s energy usage efficiency and environmental protection. Difference in thermal equilibrium theory is widely used in boiler design, exergy analysis method is established on the basis of the first law and second law of thermodynamics, by studying the cycle of the effect of energy conversion and utilization, to analyze its influencing factors, to reveal the exergy loss of location, distribution and size, find out the weak links, and a method of mining system of the boiler energy saving potential. Exergy analysis method is used for layer combustion boiler efficiency and pollutant emission characteristics analysis and evaluation, and can more objectively and accurately the energy conserving potential of the mining system of the boiler, find out the weak link of energy consumption, and improve equipment performance to improve the industrial boiler environmental friendliness.

Josephson junctions of candidate topological crystalline insulator Pb1-xSnxTe

NASA Astrophysics Data System (ADS)

Snyder, Rodney; Trimble, Christie; Taylor, Patrick; Williams, James

Incorporating superconducting ordering through proximity effects in topological states of matter offers potential routes to novel excitations with properties beyond that of simple electrons. Topological crystalline insulators TCI offer alternative routes to topological states of matter with surface states of distinct character to those in more common 3d topological insulators. We report on the fabrication Josephson junctions using MBE-grown candidate TCI material Pb-doped SnTe as weak links and characterize the departures from conventional junctions using combined DC and RF techniques. Opportunities to create junction weak links from materials possessing electronic interactions will be discussed.

Conclusions and Perspectives

NASA Astrophysics Data System (ADS)

Csermely, Peter

“As Pity and I have been attending some religious education before our marriage, I have found you an excellent quotation: ‘And further, by these, my son, be admonished of making many books there is no end; and much study is a weariness of the flesh’ (Ecclesiastes 12:14). Don’t you think it is time to finish your book?” I have good news for you, Spite We are indeed approaching the end. In this, the last chapter I will first summarize everything we have learnt about the weak-link-induced stabilization of complex systems. Then I will spend some time redefining weak links and stability. Finally, another set of advice will follow: how to build proper links in your own life. Keep this advice, Spite. Your child may need it even more than you do.

The Fiber Optic Subsystem Components on Express Logistics Carrier for International Space Station

NASA Technical Reports Server (NTRS)

Ott, Melanie N.; Switzer, Robert; Thomes, William Joe; Chuska, Richard; LaRocca, Frank; Day, Lance

2009-01-01

ISS SSP 50184 HRDL optical fiber communication subsystem, has system level requirements that were changed to accommodate large loss optical fiber links previously installed. SSQ22680 design is difficult to implement, no metal shell over socket/pin combination to protect the weak part of the pin. Additions to ISS are planned for the future. AVIM still used for interconnection in space flight applications without incident. Thermal cycling resulted in less than 0.25 dB max change in Insertion Loss for all types during cycling, nominal as compared to the AVIM. Vibration testing results conclusion; no significant changes, nominal as compared to AVIM.

A theoretical model for smoking prevention studies in preteen children.

PubMed

McGahee, T W; Kemp, V; Tingen, M

2000-01-01

The age of the onset of smoking is on a continual decline, with the prime age of tobacco use initiation being 12-14 years. A weakness of the limited research conducted on smoking prevention programs designed for preteen children (ages 10-12) is a well-defined theoretical basis. A theoretical perspective is needed in order to make a meaningful transition from empirical analysis to application of knowledge. Bandura's Social Cognitive Theory (1977, 1986), the Theory of Reasoned Action (Ajzen & Fishbein, 1980), and other literature linking various concepts to smoking behaviors in preteens were used to develop a model that may be useful for smoking prevention studies in preteen children.

Three common faults in current practice that influence the validity of data obtained from electronic air pollution instrumentation.

PubMed

Dowd, G; Thomas, R S; Monkman, J L

1975-01-01

Instrumental development is now entering a more logical era, where the former artistic character of electronics is being replaced by cold technology. Because of this, one should be expect more reliability; however, there still exist many weak links in practical application. Digital readout systems and computer processing induce a false sense of security. In reality, it is the sample-measurement relationship that determines an instrument's credibility and not the number of digits on its meter. In describing three faulty practices that greatly influence an instrument's performance, it is hoped that measurement may be more closely related to the sample!

REPRESENTATIONS OF WEAK AND STRONG INTEGRALS IN BANACH SPACES

PubMed Central

Brooks, James K.

1969-01-01

We establish a representation of the Gelfand-Pettis (weak) integral in terms of unconditionally convergent series. Moreover, absolute convergence of the series is a necessary and sufficient condition in order that the weak integral coincide with the Bochner integral. Two applications of the representation are given. The first is a simplified proof of the countable additivity and absolute continuity of the indefinite weak integral. The second application is to probability theory; we characterize the conditional expectation of a weakly integrable function. PMID:16591755

Characterization of Modified Tapioca Starch in Atmospheric Argon Plasma under Diverse Humidity by FTIR Spectroscopy

NASA Astrophysics Data System (ADS)

Deeyai, P.; Suphantharika, M.; Wongsagonsup, R.; Dangtip, S.

2013-01-01

Tapioca is economical crop grown in Thailand and continues to be one of the major sources of starch. Nowadays, tapioca starch has been widely used in industrial applications, however the native form of starch has limited the applications. Thus scientists try to modify the properties of starch for increasing the stability of the granules, pastes to low pH, heat, and shear during the food process. We modify the tapioca starch by plasma treatment under an argon atmosphere. The degree of modification is determined by following water content in the starch granules. The tablet samples of native starch are also prepared and compared with the plasma treated starch. Before plasma treatment, the starch tablets are stored under three different relative humilities (RH) including 11%, 68%, and 78%RH, respectively. The samples are characterized using FTIR spectroscopy associated with the degree of cross-linking. The results show that the water molecules are engulfed into the starch structure in two ways, a tight bond and a weak absorption of water molecules which is represented at two wave number of 1630 cm-1 and 3272 cm-1, respectively. The degree of cross-linking can be identified from the relative intensity of these two peaks with the C—O—H peak at 993 cm-1. The results show that the degree of cross-linking increase in the plasma treated starch. The degree of cross-linking of the treated starch with high relative humidity is less than that of the treated starch with low relative humidity.

A method for the production of weakly acidic cation exchange resins

NASA Astrophysics Data System (ADS)

Heller, H.; Werner, F.; Mitschker, A.; Diehl, H. V.; Schaefer, A.

1991-12-01

The invention relates to a nonpolluting method for the production of weakly acidic cation exchange resins by saponification of cross-linked acrylonitrile bead polymers, with an alkaline saponification agent at elevated temperature, according to which method the bead polymer and alkaline saponification agent are jointly added only at elevated temperature.

K-12 Distance Education in the United States: Technology Strengths, Weaknesses, and Issues.

ERIC Educational Resources Information Center

Barker, Bruce O.

This article briefly identifies seven distance education case study projects completed for the Office of Technology Assessment as part of their November 1989 report, "Linking for Learning: A New Course for Education" (ED 310 765). The paper focuses on strengths and weaknesses associated with telecommunicated distance education delivery…

Investigating the Effects of the Interaction Intensity in a Weak Measurement.

PubMed

Piacentini, Fabrizio; Avella, Alessio; Gramegna, Marco; Lussana, Rudi; Villa, Federica; Tosi, Alberto; Brida, Giorgio; Degiovanni, Ivo Pietro; Genovese, Marco

2018-05-03

Measurements are crucial in quantum mechanics, for fundamental research as well as for applicative fields like quantum metrology, quantum-enhanced measurements and other quantum technologies. In the recent years, weak-interaction-based protocols like Weak Measurements and Protective Measurements have been experimentally realized, showing peculiar features leading to surprising advantages in several different applications. In this work we analyze the validity range for such measurement protocols, that is, how the interaction strength affects the weak value extraction, by measuring different polarization weak values on heralded single photons. We show that, even in the weak interaction regime, the coupling intensity limits the range of weak values achievable, setting a threshold on the signal amplification effect exploited in many weak measurement based experiments.

IITA Cooperative Agreement Projects for Classroom Usability

NASA Technical Reports Server (NTRS)

Grabowski, Barbara

1997-01-01

Based on this review, the following conclusions are drawn regarding the 'school readiness' of the sites. All six of the sites had great appeal to the reviewers and therefore we can conclude that each has tremendous potential for use in the classroom. None, however, were given a completely 'school-ready' assessment. With recommended revisions, each site will be a valuable asset to the classroom teacher. For each as well, teachers particularly had problems with access or finding them, but once there, felt they all had some relevance. Many of the weaknesses noted related to lack of guidance for teachers with links to their curriculum or provision of activities. Other weaknesses related to the lack of educational purpose, however, this may be addressed in the development of strong teacher resources and guides linked to the sites. For those sites with a weak or without a teacher's guide, adding this component would be worth the expenditure of time and money needed.

Weak-Link Phenomena in AC-Biased Transition Edge Sensors

NASA Astrophysics Data System (ADS)

Gottardi, L.; Akamatsu, H.; Bruijn, M.; Gao, J.-R.; den Hartog, R.; Hijmering, R.; Hoevers, H.; Khosropanah, P.; Kozorezov, A.; van der Kuur, J.; van der Linden, A.; Ridder, M.

2014-08-01

It has been recently demonstrated that superconducting transition edge-sensors behave as weak-links due to longitudinally induced superconductivity from the leads with higher . In this work we study the implication of this behaviour for transition-edge sensors (TES)-based bolometers and microcalorimeter under ac bias. The TESs are read-out at frequencies between 1 and by a frequency domain multiplexer based on a linearised two-stage SQUID amplifier and high- lithographically made superconducting resonators. In particular, we focus on SRON TiAu TES bolometers with a measured dark noise equivalent power of developed for the short wavelength band for the instrument SAFARI on the SPICA telescope.

Ultrathin Two-Dimensional Covalent Organic Framework Nanosheets: Preparation and Application in Highly Sensitive and Selective DNA Detection.

PubMed

Peng, Yongwu; Huang, Ying; Zhu, Yihan; Chen, Bo; Wang, Liying; Lai, Zhuangchai; Zhang, Zhicheng; Zhao, Meiting; Tan, Chaoliang; Yang, Nailiang; Shao, Fangwei; Han, Yu; Zhang, Hua

2017-06-28

The ability to prepare ultrathin two-dimensional (2D) covalent organic framework (COF) nanosheets (NSs) in high yield is of great importance for the further exploration of their unique properties and potential applications. Herein, by elaborately designing and choosing two flexible molecules with C 3v molecular symmetry as building units, a novel imine-linked COF, namely, TPA-COF, with a hexagonal layered structure and sheet-like morphology, is synthesized. Since the flexible building units are integrated into the COF skeletons, the interlayer stacking becomes weak, resulting in the easy exfoliation of TPA-COF into ultrathin 2D NSs. Impressively, for the first time, the detailed structural information, i.e., the pore channels and individual building units in the NSs, is clearly visualized by using the recently developed low-dose imaging technique of transmission electron microscopy (TEM). As a proof-of-concept application, the obtained ultrathin COF NSs are used as a novel fluorescence sensing platform for the highly sensitive and selective detection of DNA.

20180312 - Applying a High-Throughput PBTK Model for IVIVE (SOT)

EPA Science Inventory

The ability to link in vitro and in vivo toxicity enables the use of high-throughput in vitro assays as an alternative to resource intensive animal studies. Toxicokinetics (TK) should help describe this link, but prior work found weak correlation when using a TK model for in vitr...

Applying a High-Throughput PBTK Model for IVIVE

EPA Science Inventory

The ability to link in vitro and in vivo toxicity enables the use of high-throughput in vitro assays as an alternative to resource intensive animal studies. Toxicokinetics (TK) should help describe this link, but prior work found weak correlation when using a TK model for in vitr...

EHR in the perspective of security, integrity and ethics.

PubMed

Nordberg, Ragnar

2006-01-01

Success stories of modern applications in healthcare and welfare, like the electronic health record, are always linked to end user awareness, confidence, and acceptance. Reports and surveys have given proof of these dependencies. Knowing about existing and emerging concerns and weaknesses right in advance allows to taking actions on an ethical, social, and societal level. This paper gives a review of specific observations regarding security, privacy, authentication, integrity and ethical aspects when operating an electronic health record (EHR) system in a hospital, an open care department and in a wider community of the health care sector. A reference is given to existing and emerging international standards related to the aforementioned aspects.

A Domain Analysis Model for eIRB Systems: Addressing the Weak Link in Clinical Research Informatics

PubMed Central

He, Shan; Narus, Scott P.; Facelli, Julio C.; Lau, Lee Min; Botkin, Jefferey R.; Hurdle, John F.

2014-01-01

Institutional Review Boards (IRBs) are a critical component of clinical research and can become a significant bottleneck due to the dramatic increase, in both volume and complexity of clinical research. Despite the interest in developing clinical research informatics (CRI) systems and supporting data standards to increase clinical research efficiency and interoperability, informatics research in the IRB domain has not attracted much attention in the scientific community. The lack of standardized and structured application forms across different IRBs causes inefficient and inconsistent proposal reviews and cumbersome workflows. These issues are even more prominent in multi-institutional clinical research that is rapidly becoming the norm. This paper proposes and evaluates a domain analysis model for electronic IRB (eIRB) systems, paving the way for streamlined clinical research workflow via integration with other CRI systems and improved IRB application throughput via computer-assisted decision support. PMID:24929181

Direct quantum process tomography via measuring sequential weak values of incompatible observables.

PubMed

Kim, Yosep; Kim, Yong-Su; Lee, Sang-Yun; Han, Sang-Wook; Moon, Sung; Kim, Yoon-Ho; Cho, Young-Wook

2018-01-15

The weak value concept has enabled fundamental studies of quantum measurement and, recently, found potential applications in quantum and classical metrology. However, most weak value experiments reported to date do not require quantum mechanical descriptions, as they only exploit the classical wave nature of the physical systems. In this work, we demonstrate measurement of the sequential weak value of two incompatible observables by making use of two-photon quantum interference so that the results can only be explained quantum physically. We then demonstrate that the sequential weak value measurement can be used to perform direct quantum process tomography of a qubit channel. Our work not only demonstrates the quantum nature of weak values but also presents potential new applications of weak values in analyzing quantum channels and operations.

Weak English Language Literacy and Early School Leaving in a Maltese Context

ERIC Educational Resources Information Center

Martinelli, Victor

2016-01-01

This study considers the issue of weak literacy development and early school leaving in Malta. In spite of a lack of a direct or indirect causal link between the two, in the case of Malta these issues seem to be almost exclusively specific to children attending the State school. Children from the Church and the Independent sectors are minimally…

Survey of Quantification and Distance Functions Used for Internet-based Weak-link Sociological Phenomena

DTIC Science & Technology

2013-01-16

linkages, as well as the social strong and weak ties, social cohesion , position and distance. See Appendix II. 8) The co-PI was willing to write it out...Dawn Robinson, A Summary of Sociological Concepts Related to Social Network and Its Techniques for Quantifying Social Cohesion , Social Position, Social Distance, a manuscript, 2013. 3

Exploring DNA-binding Proteins with In Vivo Chemical Cross-linking and Mass Spectrometry

PubMed Central

Qiu, Haibo; Wang, Yinsheng

2009-01-01

DNA-binding proteins are very important constituents of proteomes of all species and play crucial roles in transcription, DNA replication, recombination, repair and other activities associated with DNA. Although a number of DNA-binding proteins have been identified, many proteins involved in gene regulation and DNA repair are likely still unknown because of their dynamic and/or weak interactions with DNA. In this report, we described an approach for the comprehensive identification of DNA-binding proteins with in vivo formaldehyde cross-linking and LC-MS/MS. DNA-binding proteins could be purified via the isolation of DNA-protein complexes and released from the complexes by reversing the cross-linking. By using this method, we were able to identify more than one hundred DNA-binding proteins, such as proteins involved in transcription, gene regulation, DNA replication and repair, and a large number of proteins which are potentially associated with DNA and DNA-binding proteins. This method should be generally applicable to the investigation of other nucleic acid-binding proteins, and hold great potential in the comprehensive study of gene regulation, DNA damage response and repair, as well as many other critical biological processes at proteomic level. PMID:19714816

Loss of functionally unique species may gradually undermine ecosystems

PubMed Central

O'Gorman, Eoin J.; Yearsley, Jon M.; Crowe, Tasman P.; Emmerson, Mark C.; Jacob, Ute; Petchey, Owen L.

2011-01-01

Functionally unique species contribute to the functional diversity of natural systems, often enhancing ecosystem functioning. An abundance of weakly interacting species increases stability in natural systems, suggesting that loss of weakly linked species may reduce stability. Any link between the functional uniqueness of a species and the strength of its interactions in a food web could therefore have simultaneous effects on ecosystem functioning and stability. Here, we analyse patterns in 213 real food webs and show that highly unique species consistently tend to have the weakest mean interaction strength per unit biomass in the system. This relationship is not a simple consequence of the interdependence of both measures on body size and appears to be driven by the empirical pattern of size structuring in aquatic systems and the trophic position of each species in the web. Food web resolution also has an important effect, with aggregation of species into higher taxonomic groups producing a much weaker relationship. Food webs with fewer unique and less weakly interacting species also show significantly greater variability in their levels of primary production. Thus, the loss of highly unique, weakly interacting species may eventually lead to dramatic state changes and unpredictable levels of ecosystem functioning. PMID:21106593

Prostate cancer link to vasectomy is weak.

PubMed

1998-03-01

Health care providers and men seeking vasectomies are still unsure about the nature of the association between vasectomy and prostate cancer. Two large cohort studies published in 1993 found increased relative risks for prostate cancer in vasectomized men of 1.56 and 1.66. However, this level of increased relative risk represents only a weak association between the procedure and cancer. Three other studies of similar design reported no such association. Several divisions of the National Institutes of Health examined the research and issued the joint statement in 1993 that providers should continue to offer vasectomy and perform the procedure, the reversal of vasectomies is unwarranted to prevent prostate cancer, and screening for prostate cancer should not be any different for men who have had a vasectomy than for those who have not. Joel Feigin, MD, associate professor of family medicine at Robert Wood Johnson Medical School in New Brunswick, NJ, and director of the Coventry No-Scalpel Vasectomy Center in Phillipsburg, NJ, recommends dealing proactively with the cancer link as a standard part of counseling. Thomas R. Pritchett, MD, a urologist on the clinical faculty of the University of Washington and the department of urology at Virginia Mason Medical Center in Seattle says that the strongest link to increased risk for prostate cancer is family history. Diet, race, and vasectomy are only weak associations. A definite link also exists between testosterone and prostate cancer, but undergoing vasectomy neither increases nor decreases a man's testosterone level.

All high Tc edge-geometry weak links utilizing Y-Ba-Cu-O barrier layers

NASA Technical Reports Server (NTRS)

Hunt, B. D.; Foote, M. C.; Bajuk, L. J.

1991-01-01

High quality YBa2Cu3O(7-x) normal-metal/YBa2Cu3O(7-x) edge-geometry weak links have been fabricated using nonsuperconducting Y-Ba-Cu-O barrier layers deposited by laser ablation at reduced growth temperatures. Devices incorporating 25-100 A thick barrier layers exhibit current-voltage characteristics consistent with the resistively shunted junction model, with strong microwave and magnetic field response at temperatures up to 85 K. The critical currents vary exponentially with barrier thickness, and the resistances scale linearly with Y-Ba-Cu-O interlayer thickness and device area, indicating good barrier uniformity, with an effective mormal metal coherence length of 20 A.

Weak bump quasars

NASA Technical Reports Server (NTRS)

Wilkes, B. J.; Mcdowell, J.

1994-01-01

Research into the optical, ultraviolet and infrared continuum emission from quasars and their host galaxies was carried out. The main results were the discovery of quasars with unusually weak infrared emission and the construction of a quantitative estimate of the dispersion in quasar continuum properties. One of the major uncertainties in the measurement of quasar continuum strength is the contribution to the continuum of the quasar host galaxy as a function of wavelength. Continuum templates were constructed for different types of host galaxy and individual estimates made of the decomposed quasar and host continua based on existing observations of the target quasars. The results are that host galaxy contamination is worse than previously suspected, and some apparent weak bump quasars are really normal quasars with strong host galaxies. However, the existence of true weak bump quasars such as PHL 909 was confirmed. The study of the link between the bump strength and other wavebands was continued by comparing with IRAS data. There is evidence that excess far infrared radiation is correlated with weaker ultraviolet bumps. This argues against an orientation effect and implies a probable link with the host galaxy environment, for instance the presence of a luminous starburst. However, the evidence still favors the idea that reddening is not important in those objects with ultraviolet weak bumps. The same work has led to the discovery of a class of infrared weak quasars. Pushing another part of the envelope of quasar continuum parameter space, the IR-weak quasars have implications for understanding the effects of reddening internal to the quasars, the reality of ultraviolet turnovers, and may allow further tests of the Phinney dust model for the IR continuum. They will also be important objects for studying the claimed IR to x-ray continuum correlation.

Strong mechanically induced effects in DC current-biased suspended Josephson junctions

NASA Astrophysics Data System (ADS)

McDermott, Thomas; Deng, Hai-Yao; Isacsson, Andreas; Mariani, Eros

2018-01-01

Superconductivity is a result of quantum coherence at macroscopic scales. Two superconductors separated by a metallic or insulating weak link exhibit the AC Josephson effect: the conversion of a DC voltage bias into an AC supercurrent. This current may be used to activate mechanical oscillations in a suspended weak link. As the DC-voltage bias condition is remarkably difficult to achieve in experiments, here we analyze theoretically how the Josephson effect can be exploited to activate and detect mechanical oscillations in the experimentally relevant condition with purely DC current bias. We unveil how changing the strength of the electromechanical coupling results in two qualitatively different regimes showing dramatic effects of the oscillations on the DC-voltage characteristic of the device. These include the appearance of Shapiro-type plateaus for weak coupling and a sudden mechanically induced retrapping for strong coupling. Our predictions, measurable in state-of-the-art experimental setups, allow the determination of the frequency and quality factor of the resonator using DC only techniques.

Equitable Partnerships for Mutual Learning or Perpetuator of North-South Power Imbalances? Ireland-South Africa School Links

ERIC Educational Resources Information Center

Gallwey, Susan Kresky; Wilgus, Gay

2014-01-01

This study examines how various components of a school-linking programme between Ireland and South Africa either support Development Education's goal of sustainable, equitable partnerships that enable mutual learning between Northern and Southern countries or, instead, promote power imbalances that reify stereotypic images of weak, needy…

Spin precession in spin-orbit coupled weak links: Coulomb repulsion and Pauli quenching

NASA Astrophysics Data System (ADS)

Shekhter, R. I.; Entin-Wohlman, O.; Jonson, M.; Aharony, A.

2017-12-01

A simple model for the transmission of pairs of electrons through a weak electric link in the form of a nanowire made of a material with strong electron spin-orbit interaction (SOI) is presented, with emphasis on the effects of Coulomb interactions and the Pauli exclusion principle. The constraints due to the Pauli principle are shown to "quench" the coherent SOI-induced precession of the spins when the spatial wave packets of the two electrons overlap significantly. The quenching, which results from the projection of the pair's spin states onto spin-up and spin-down states on the link, breaks up the coherent propagation in the link into a sequence of coherent hops that add incoherently. Applying the model to the transmission of Cooper pairs between two superconductors, we find that in spite of Pauli quenching, the Josephson current oscillates with the strength of the SOI, but may even change its sign (compared to the limit of the Coulomb blockade, when the quenching is absent). Conditions for an experimental detection of these features are discussed.

Decision- rather than scenario-centred downscaling: Towards smarter use of climate model outputs

NASA Astrophysics Data System (ADS)

Wilby, Robert L.

2013-04-01

Climate model output has been used for hydrological impact assessments for at least 25 years. Scenario-led methods raise awareness about risks posed by climate variability and change to the security of supplies, performance of water infrastructure, and health of freshwater ecosystems. However, it is less clear how these analyses translate into actionable information for adaptation. One reason is that scenario-led methods typically yield very large uncertainty bounds in projected impacts at regional and river catchment scales. Consequently, there is growing interest in vulnerability-based frameworks and strategies for employing climate model output in decision-making contexts. This talk begins by summarising contrasting perspectives on climate models and principles for testing their utility for water sector applications. Using selected examples it is then shown how water resource systems may be adapted with varying levels of reliance on climate model information. These approaches include the conventional scenario-led risk assessment, scenario-neutral strategies, safety margins and sensitivity testing, and adaptive management of water systems. The strengths and weaknesses of each approach are outlined and linked to selected water management activities. These cases show that much progress can be made in managing water systems without dependence on climate models. Low-regret measures such as improved forecasting, better inter-agency co-operation, and contingency planning, yield benefits regardless of the climate outlook. Nonetheless, climate model scenarios are useful for evaluating adaptation portfolios, identifying system thresholds and fixing weak links, exploring the timing of investments, improving operating rules, or developing smarter licensing regimes. The most problematic application remains the climate change safety margin because of the very low confidence in extreme precipitation and river flows generated by climate models. In such cases, it is necessary to understand the trade-offs that exist between the additional costs of a scheme and the level of risk that is accommodated.

Link prediction boosted psychiatry disorder classification for functional connectivity network

NASA Astrophysics Data System (ADS)

Li, Weiwei; Mei, Xue; Wang, Hao; Zhou, Yu; Huang, Jiashuang

2017-02-01

Functional connectivity network (FCN) is an effective tool in psychiatry disorders classification, and represents cross-correlation of the regional blood oxygenation level dependent signal. However, FCN is often incomplete for suffering from missing and spurious edges. To accurate classify psychiatry disorders and health control with the incomplete FCN, we first `repair' the FCN with link prediction, and then exact the clustering coefficients as features to build a weak classifier for every FCN. Finally, we apply a boosting algorithm to combine these weak classifiers for improving classification accuracy. Our method tested by three datasets of psychiatry disorder, including Alzheimer's Disease, Schizophrenia and Attention Deficit Hyperactivity Disorder. The experimental results show our method not only significantly improves the classification accuracy, but also efficiently reconstructs the incomplete FCN.

Atmospheric turbulence mitigation in an OAM-based MIMO free-space optical link using spatial diversity combined with MIMO equalization.

PubMed

Ren, Yongxiong; Wang, Zhe; Xie, Guodong; Li, Long; Willner, Asher J; Cao, Yinwen; Zhao, Zhe; Yan, Yan; Ahmed, Nisar; Ashrafi, Nima; Ashrafi, Solyman; Bock, Robert; Tur, Moshe; Willner, Alan E

2016-06-01

We explore the mitigation of atmospheric turbulence effects for orbital angular momentum (OAM)-based free-space optical (FSO) communications with multiple-input multiple-output (MIMO) architecture. Such a system employs multiple spatially separated aperture elements at the transmitter/receiver, and each transmitter aperture contains multiplexed data-carrying OAM beams. We propose to use spatial diversity combined with MIMO equalization to mitigate both weak and strong turbulence distortions. In a 2×2 FSO link with each transmitter aperture containing two multiplexed OAM modes of ℓ=+1 and ℓ=+3, we experimentally show that at least two OAM data channels could be recovered under both weak and strong turbulence distortions using selection diversity assisted with MIMO equalization.

Comment on ''Carrier-concentration dependence of critical superconducting current induced by the proximity effect in silicon''

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

Kleinsasser, A.W.

1987-06-01

It is pointed out that effect of an applied gate voltage on the critical current observed in a gate-controlled Si-coupled weak link by Nishino, Yamada, and Kawabe (Phy. Rev. B 33, 2042 (1986)) is much larger than that expected from the small change of carrier density in the link.

Linking Early Childhood Education with Indigenous Education Using Gamification: The Case of Maintaining Cultural Value and Identity

ERIC Educational Resources Information Center

Ukala, Catherine Chinyere; Agabi, Ogar G.

2017-01-01

Cultural values and identities remain the bench mark for national identity, cohesion, patriotism and harmonious coexistence in any society. The introduction of western education into West Africa created a weak bridge between the indigenous education and the western education which needs to be properly linked using curriculum harmonisation. This…

Exacerbation of pathology by oxidative stress in respiratory and locomotor muscles with Duchenne muscular dystrophy.

PubMed

Lawler, John M

2011-05-01

Duchenne muscular dystrophy (DMD) is the most devastating type of muscular dystrophy, leading to progressive weakness of respiratory (e.g. diaphragm) and locomotor muscles (e.g. gastrocnemius). DMD is caused by X-linked defects in the gene that encodes for dystrophin, a key scaffolding protein of the dystroglycan complex (DCG) within the sarcolemmal cytoskeleton. As a result of a compromised dystroglycan complex, mechanical integrity is impaired and important signalling proteins (e.g. nNOS, caveolin-3) and pathways are disrupted. Disruption of the dystroglycan complex leads to high susceptibility to injury with repeated, eccentric contractions as well as inflammation, resulting in significant damage and necrosis. Chronic damage and repair cycling leads to fibrosis and weakness. While the link between inflammation with damage and weakness in the DMD diaphragm is unresolved, elevated oxidative stress may contribute to damage, weakness and possibly fibrosis. While utilization of non-specific antioxidant interventions has yielded inconsistent results, recent data suggest that NAD(P)H oxidase could play a pivotal role in elevating oxidative stress via integrated changes in caveolin-3 and stretch-activated channels (SACs). Oxidative stress may act as an amplifier, exacerbating disruption of the dystroglycan complex, upregulation of the inflammatory transcription factor NF-B, and thus functional impairment of force-generating capacity.

Can the Lateral Proximity Effect Be Used to Create the Superconducting Transition of a Micron-Sized TES?

NASA Technical Reports Server (NTRS)

Barrentine, E. M.; Brandl, D. E.; Brown, A. D.; Denis, K. L.; Fionkbeiner, F. M.; Hsieh, W. T.; Nagler, P. C.; Stevenson, T. R.; Timble, P. T.; U-Yen, K.

2012-01-01

Recent measurements of micron-sized Mo/Au bilayer Transition Edge Sensors (TESs) have demonstrated that the TES can behave like an S-S'-S weak link due to the lateral proximity effect from superconducting leads. In this regime the Tc is a function of bias current, and the effective Tc shifts from the bilayer Tc towards the lead Tc. We explore the idea that a micron-sized S-N-S weak link could provide a new method to engineer the TES Tc. This method would be particularly useful when small size requirements for a bilayer TES (such as for a hot-electron microbolometer) lead to undesirable shifts in the bilayer Te. We present measurements of a variety of micron-sized normal Au 'TES' devices with Nb leads. We find no evidence of a superconducting transition in the Au film of these devices, in dramatic contrast to the strong lateral proximity effect seen in micron-sized Mo/Au bilayer devices. The absence of a transition in these devices is also in disagreement with theoretical predictions for S-N-S weak links. We hypothesize that a finite contact resistance between the Nb and Au may be weakening the effect. We conclude that the use of the lateral proximity effect to create a superconducting transition will be difficult given current fabrication procedures.

Bridge pier foundation evaluation using cross-hole seismic tomographic imaging

NASA Astrophysics Data System (ADS)

Butchibabu, B.; Sandeep, N.; Sivaram, Y. V.; Jha, P. C.; Khan, P. K.

2017-09-01

An ambitious project connecting Jammu and Srinagar through a railway link in tectonically active and geologically complex Himalayan Mountain terrain is under progress. Under this project, the world's highest (359 m) railway arch-bridge is under construction across the River Chenab in the northern territory of India. This mega engineering structure has a two-fold ribbed arch design, comprising of steel girders. During the excavation for one of the concrete pillars on the right abutment, wide open joints and weak/shear zones were noticed. The width of these joints varies from 30 to 50 cm, trending along N170° with a dip of 65°. The foundation area of this pillar is 13 m × 24 m and on the cut slopes of the right bank of Chenab River. These exposed joints and weak zones were treated with consolidation grouting to strengthen the foundation area. To delineate the extent of these joints and weak zones below the foundation level, seismic tomography was carried out in five boreholes drilled for this purpose to cover the 300 sq-m area. The results of cross-hole seismic tomography reveals the presence of three low velocity (≤ 2600 m/s) anomalous zones below the foundation area. This also ascertained the efficacy of grouting in consolidating the joints and weak zones. Later, rock-mass quality (Q) was determined based on the relationship between the P-wave velocity and the Q-value (Barton, 2002) to infer the support system for the slope stabilization below the foundation. 3-D visualization of the seismic velocity demarcates the extent of weak or untreated zones. This methodology facilitates to update the design parameters according to Q-values during the construction stage and estimate the required level of reinforcement and support system. Similar methodology can be applicable in other areas under same site conditions.

Research on the development and preliminary application of Beijing agricultural sci-tech service hotline WebApp in agricultural consulting services

NASA Astrophysics Data System (ADS)

Yu, Weishui; Luo, Changshou; Zheng, Yaming; Wei, Qingfeng; Cao, Chengzhong

2017-09-01

To deal with the “last kilometer” problem during the agricultural science and technology information service, we analyzed the feasibility, necessity and advantages of WebApp applied to agricultural information service and discussed the modes of WebApp used in agricultural information service based on the requirements analysis and the function of WebApp. To overcome the existing App’s defects of difficult installation and weak compatibility between the mobile operating systems, the Beijing Agricultural Sci-tech Service Hotline WebApp was developed based on the HTML and JAVA technology. The WebApp has greater compatibility and simpler operation than the Native App, what’s more, it can be linked to the WeChat public platform making it spread easily and run directly without setup process. The WebApp was used to provide agricultural expert consulting services and agriculture information push, obtained a good preliminary application achievement. Finally, we concluded the creative application of WebApp in agricultural consulting services and prospected the development of WebApp in agricultural information service.

Wear Measurement of Highly Cross-linked UHMWPE using a 7Be Tracer Implantation Technique

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

Wimmer, Markus A.; Laurent, Michael P.; Dwivedi, Yasha

2013-01-01

The very low wear rates achieved with the current highly cross-linked ultrahigh molecular weight polyethylenes (UHMWPE) used in joint prostheses have proven to be difficult to measure accurately by gravimetry. Tracer methods are there- fore being explored. The purpose of this study was to perform a proof-of-concept experiment on the use of the radioactive tracer beryllium-7 (7Be) for the determination of in vitro wear in a highly cross-linked orthopedic UHMWPE. Three cross-linked and four conventional UHMWPE pins made from compression- molded GUR 1050, were activated with 109 to 1010 7Be nuclei using a new implantation setup that produced a homogenousmore » distribution of implanted nuclei up to 8.5 lm below the surface. The pins were tested for wear in a six-station pin-on-flat appara- tus for up to 7.1 million cycles (178 km). A Germanium gamma detector was employed to determine activity loss of the UHMWPE pins at preset intervals during the wear test. The wear of the cross-linked UHMWPE pins was readily detected and esti- mated to be 17 6 3 lg per million cycles. The conventional-to- cross-linked ratio of the wear rates was 13.1 6 0.8, in the expected range for these materials. Oxidative degradation dam- age from implantation was negligible; however, a weak depend- ence of wear on implantation dose was observed limiting the number of radioactive tracer atoms that can be introduced. Future applications of this tracer technology may include the analysis of location-specific wear, such as loss of material in the post or backside of a tibial insert.« less

An Application of Outer Membrane Protein P6-Specific Enzyme-Linked Immunosorbent Assay for Detection of Haemophilus influenzae in Middle Ear Fluids and Nasopharyngeal Secretions

PubMed Central

Hotomi, Muneki; Togawa, Akihisa; Kono, Masamitsu; Sugita, Gen; Sugita, Rinya; Fujimaki, Yutaka; Kamide, Yosuke; Uchizono, Akihiro; Kanesada, Keiko; Sawada, Shoichi; Okitsu, Naohiro; Masuda, Hisayo; Tanaka, Hideaki; Tanaka, Yumi; Yamanaka, Noboru

2013-01-01

An enzyme-linked immunosorbent assay specific to outer membrane protein P6 (P6-ELISA) was applied for detecting Haemophilus influenzae in middle ear fluids (MEFs) from acute otitis media (AOM) patients and in nasopharyngeal secretions (NPSs) from acute rhinosinusitis patients. P6-ELISA had a sensitivity of 83.3% for MEFs and 71.5% for NPSs and a specificity of 85.6% for MEFs and 92.5% for NPSs, respectively. Real-time PCR exhibited significant differences in the number of ompP1 gene copies among samples determined by P6-ELISA to be positive and negative for H. influenzae. However, because the P6-ELISA test has the reactivity in Haemophilus species include two commensals H. haemolyticus and H. parainfluenzae, it is thus a weak method in order to detect only NTHi correctly. Consequently, diagnosis using the P6-ELISA should be based on an overall evaluation, including the results of other related examinations and clinical symptoms to prevent misleading conclusions in clinical setting. PMID:24015192

An application of outer membrane protein p6-specific enzyme-linked immunosorbent assay for detection of haemophilus influenzae in middle ear fluids and nasopharyngeal secretions.

PubMed

Hotomi, Muneki; Togawa, Akihisa; Kono, Masamitsu; Sugita, Gen; Sugita, Rinya; Fujimaki, Yutaka; Kamide, Yosuke; Uchizono, Akihiro; Kanesada, Keiko; Sawada, Shoichi; Okitsu, Naohiro; Masuda, Hisayo; Tanaka, Hideaki; Tanaka, Yumi; Yamanaka, Noboru

2013-01-01

An enzyme-linked immunosorbent assay specific to outer membrane protein P6 (P6-ELISA) was applied for detecting Haemophilus influenzae in middle ear fluids (MEFs) from acute otitis media (AOM) patients and in nasopharyngeal secretions (NPSs) from acute rhinosinusitis patients. P6-ELISA had a sensitivity of 83.3% for MEFs and 71.5% for NPSs and a specificity of 85.6% for MEFs and 92.5% for NPSs, respectively. Real-time PCR exhibited significant differences in the number of ompP1 gene copies among samples determined by P6-ELISA to be positive and negative for H. influenzae. However, because the P6-ELISA test has the reactivity in Haemophilus species include two commensals H. haemolyticus and H. parainfluenzae, it is thus a weak method in order to detect only NTHi correctly. Consequently, diagnosis using the P6-ELISA should be based on an overall evaluation, including the results of other related examinations and clinical symptoms to prevent misleading conclusions in clinical setting.

Quantifying systematics from the shear inversion on weak-lensing peak counts

NASA Astrophysics Data System (ADS)

Lin, Chieh-An; Kilbinger, Martin

2018-06-01

Weak-lensing peak counts provide a straightforward way to constrain cosmology by linking local maxima of the lensing signal to the mass function. Recent applications to data have already been numerous and fruitful. However, the importance of understanding and dealing with systematics increases as data quality reaches an unprecedented level. One of the sources of systematics is the convergence-shear inversion. This effect, inevitable when carrying out a convergence field from observations, is usually neglected by theoretical peak models. Thus, it could have an impact on cosmological results. In this paper, we study the bias from neglecting (mis-modeling) the inversion. Our tests show a small but non-negligible bias. The cosmological dependence of this bias seems to be related to the parameter Σ8 ≡ (Ωm/(1 - α))1 - α(σ8/α)α, where α = 2/3. When this bias propagates to the parameter estimation, we discovered that constraint contours involving the dark energy equation of state can differ by 2σ. Such an effect can be even larger for future high-precision surveys and we argue that the inversion should be properly modeled for theoretical peak models.

CPLOAS_2 User Manual.

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

Sallaberry, Cedric Jean-Marie; Helton, Jon C.

2015-05-01

Weak link (WL)/strong link (SL) systems are important parts of the overall operational design of high - consequence systems. In such designs, the SL system is very robust and is intended to permit operation of the entire system under, and only under, intended conditions. In contrast, the WL system is intended to fail in a predictable and irreversible manner under accident conditions and render the entire system inoperable before an accidental operation of the SL system. The likelihood that the WL system will fail to d eactivate the entire system before the SL system fails (i.e., degrades into a configurationmore » that could allow an accidental operation of the entire system) is referred to as probability of loss of assured safety (PLOAS). This report describes the Fortran 90 program CPLOAS_2 that implements the following representations for PLOAS for situations in which both link physical properties and link failure properties are time - dependent: (i) failure of all SLs before failure of any WL, (ii) failure of any SL before f ailure of any WL, (iii) failure of all SLs before failure of all WLs, and (iv) failure of any SL before failure of all WLs. The effects of aleatory uncertainty and epistemic uncertainty in the definition and numerical evaluation of PLOAS can be included in the calculations performed by CPLOAS_2. Keywords: Aleatory uncertainty, CPLOAS_2, Epistemic uncertainty, Probability of loss of assured safety, Strong link, Uncertainty analysis, Weak link« less

The Role of Proximity Effects in Transition-Edge Sensor Design and Performance

NASA Technical Reports Server (NTRS)

Smith, Stephen J.

2012-01-01

Transition-edge sensor (TES) microcalorimeters and bolometers are under development by numerous groups worldwide for a variety of applications involving the measurement of particle and photon radiation. Recent experimental and theoretical progress has led to the realization that the fundamental physics of some TES systems involves the longitudinal proximity effect between the electrical bias contacts and the TES. As such, these devices are described as SS'S (or SN'S) weak-links exhibiting Fraunhofer-like magnetic field dependence, and exponential temperature dependence, of the critical current. These discoveries, for the first time, provide a realistic theoretical framework for predicting the resistive transition as a function of temperature, current and magnetic field. In this contribution, we review the latest theoretical and experimental results and investigate how proximity effects play an important role in determining the resistive transition characteristics, which ultimately determines the dynamic range and energy resolution of TES detectors. We investigate how these effects could be utilized in device design to engineer desired transition characteristics for a given application.

Suggestions for Designers of Navy Electronic Equipment. 1989 Edition. Revision B

DTIC Science & Technology

1989-07-01

his design and the weak links in the reliability chain. From this information, he can make more reasonable decisions as to the need for design changes...SYSTEMS CENTER San Diego. Caifornl 92152-5000 ~89 12 12 084 It is a pleasure to make available this 1989 -Suggestions for Designers of Navy Electronic...the costs of supporting equipment for mission operations. The factors relate to early design decisions . Design deficiencies or design weaknesses in

Astronomy-inspired Atomic and Molecular Physics

NASA Astrophysics Data System (ADS)

Rau, A. R. P.

2002-02-01

Aimed at senior undergraduate and first-year graduate students in departments of physics and astronomy, this textbook gives a systematic treatment of atomic and molecular structure and spectra, together with the effect of weak and strong external electromagnetic fields. Topics chosen are those of interest in astronomy and indeed many were inspired by specific astronomical contexts. Examples include the negative ion of hydrogen and the effects of strong magnetic fields such as those occurring on certain white dwarfs and neutron stars. Adiabatic and non-adiabatic handling of electron correlations and application to processes such as dielectronic recombination are included. Astronomical examples are provided throughout as well as end-of-the chapter problems and exercises. Over seventy illustrative diagrams complete this unique and comprehensive volume. Link: http://www.wkap.nl/prod/b/1-4020-0467-2

Common Childhood Orthopedic Conditions

MedlinePlus

... might be linked to other conditions, such as cerebral palsy, muscle weakness disorders, autism, or other nervous system ... be related to existing medical problems such as cerebral palsy. Doctors rarely have to treat pigeon-toed feet. ...

Topology association analysis in weighted protein interaction network for gene prioritization

NASA Astrophysics Data System (ADS)

Wu, Shunyao; Shao, Fengjing; Zhang, Qi; Ji, Jun; Xu, Shaojie; Sun, Rencheng; Sun, Gengxin; Du, Xiangjun; Sui, Yi

2016-11-01

Although lots of algorithms for disease gene prediction have been proposed, the weights of edges are rarely taken into account. In this paper, the strengths of topology associations between disease and essential genes are analyzed in weighted protein interaction network. Empirical analysis demonstrates that compared to other genes, disease genes are weakly connected with essential genes in protein interaction network. Based on this finding, a novel global distance measurement for gene prioritization with weighted protein interaction network is proposed in this paper. Positive and negative flow is allocated to disease and essential genes, respectively. Additionally network propagation model is extended for weighted network. Experimental results on 110 diseases verify the effectiveness and potential of the proposed measurement. Moreover, weak links play more important role than strong links for gene prioritization, which is meaningful to deeply understand protein interaction network.

Reversible and Selective Encapsulation of Dextromethorphan and β-Estradiol Using an Asymmetric Molecular Capsule Assembled via the Weak-Link Approach.

PubMed

Mendez-Arroyo, Jose; d'Aquino, Andrea I; Chinen, Alyssa B; Manraj, Yashin D; Mirkin, Chad A

2017-02-01

An allosterically regulated, asymmetric receptor featuring a binding cavity large enough to accommodate three-dimensional pharmaceutical guest molecules as opposed to planar, rigid aromatics, was synthesized via the Weak-Link Approach. This architecture is capable of switching between an expanded, flexible "open" configuration and a collapsed, rigid "closed" one. The structure of the molecular receptor can be completely modulated in situ through the use of simple ionic effectors, which reversibly control the coordination state of the Pt(II) metal hinges to open and close the molecular receptor. The substantial change in binding cavity size and electrostatic charge between the two configurations is used to explore the capture and release of two guest molecules, dextromethorphan and β-estradiol, which are widely found as pollutants in groundwater.

Perceived neighborhood walkability and physical exercise: An examination of casual communication in a social process.

PubMed

Yamamoto, Masahiro; Jo, Hyerim

2018-05-01

Despite the accumulated evidence for the environmental correlates of physical activity, social processes underlying this association are not entirely clear. This study positions communication characterized by weak ties as a social mechanism linking neighborhood walkability with physical exercise. Data from a survey of Chicago residents show that perceived neighborhood walkability is positively related to frequency of weak-tie communication. Frequency of weak-tie communication is related positively to perceived social cohesion and negatively to anonymity, both of which are significantly related to frequency of physical exercise in the neighborhood. Data also show a sequential indirect relationship involving perceived neighborhood walkability, weak-tie communication, anonymity, and physical exercise. Implications are discussed in terms of the role of communication in promoting locality-based physical exercise. Copyright © 2018 Elsevier Ltd. All rights reserved.

Charge segregation in weakly ionized microgels

DOE PAGES

Hyatt, John S.; Douglas, Alison M.; Stanley, Chris; ...

2017-01-19

Here we investigate microgels synthesized from N-isopropylacrylamide (NIPAM) copolymerized with a large mol% of acrylic acid, finding that when the acid groups are partially ionized at high temperatures, competition between ion-induced swelling and hydrophobic deswelling of poly(NIPAM) chains results in microphase separation. In cross-linked microgels, this manifests as a dramatic decrease in the ratio between the radius of gyration and the hydrodynamic radius to ~0.2, indicating that almost all the mass of the microgel is concentrated near the particle center. We also observe a concurrent decrease of the polymer network length scale via small-angle neutron scattering, confirming the presence ofmore » a dense, deswollen core surrounded by a diffuse, charged periphery. We compare these results to those obtained for a system of charged ultralow-cross-linked microgels; the form factor shows a distinct peak at high q when the temperature exceeds a threshold value. Lastly, we successfully fit the form factor to theory developed to describe scattering from weakly charged gels in poor solvents, and we tie this behavior to charge segregation in the case of the cross-linked microgels.« less

High-Temperature High-Current Superconductors: Preparation, Structure, Superconducting Properties, and Flux-Pinning Mechanisms

NASA Astrophysics Data System (ADS)

Hu, Shouxiang

In bulk high-T_{rm c } superconductors, weak links at the grain boundaries and weak flux pinning are the two major causes of low critical current density (J_{ rm c}) at 77 K. In the present study, various processes designed and developed to address these problems are discussed. The novel pressurized-partial -melt-growth process, which leads to a relatively large improvement in the microstructure as well as in the superconducting properties of bulk Y-Ba-Cu-O superconductors, is described. The effects of introducing foreign elements to serve as pinning centers are reported, and the associated anomalous superconducting phenomena are explained on the basis of a detailed study of basic pinning mechanisms related to the presence of small defects. It is demonstrated that in certain cases the pinning force induced by the compression of the vortex line may be comparable to, or even larger than, the usually recognized pinning force due to the condensation energy. Studies of the pinning mechanism corresponding to large boundary defects show that boundary defects associated with certain non-superconducting inclusions and isolated weak links have a very positive role in the enhancement of both the critical current density and the effective activation energy for flux creep. However, even optimized theoretical estimates show that it will be difficult to reach J_ {rm c} values of 5 times 10^5 A/cm^2 at 77 K and H = 1 T by increasing the number of Y_2BaCuO inclusions alone. Although even higher J_{rm c} values may be achieved by introducing other types of defects using alternative approaches such as irradiation, and, probably, chemical doping, the presence of large amount of boundary defects is very important in causing a large increase in the effective activation energy for flux creep. Also studied are the anisotropic electromagnetic features of the grain-aligned YBa_2Cu _3O_{rm x} bulk superconductors. The development of novel processing methods guided by improved understanding of the basic mechanisms involved opens the way for the preparation of high-quality bulk high-T_{rm c} superconducting materials for a wide variety of applications.

Tunable Fano resonance using weak-value amplification with asymmetric spectral response as a natural pointer

NASA Astrophysics Data System (ADS)

Singh, Ankit K.; Ray, Subir K.; Chandel, Shubham; Pal, Semanti; Gupta, Angad; Mitra, P.; Ghosh, N.

2018-05-01

Weak measurement enables faithful amplification and high-precision measurement of small physical parameters and is under intensive investigation as an effective tool in metrology and for addressing foundational questions in quantum mechanics. Here we demonstrate weak-value amplification using the asymmetric spectral response of Fano resonance as the pointer arising naturally in precisely designed metamaterials, namely, waveguided plasmonic crystals. The weak coupling between the polarization degree of freedom and the spectral response of Fano resonance arises due to a tiny shift in the asymmetric spectral response between two orthogonal linear polarizations. By choosing the preselected and postselected polarization states to be nearly mutually orthogonal, we observe both real and imaginary weak-value amplifications manifested as a spectacular shift of the Fano-resonance peak and narrowing (or broadening) of the resonance linewidth, respectively. The remarkable control and tunability of Fano resonance in a single device enabled by weak-value amplification may enhance active Fano-resonance-based applications in the nano-optical domain. In general, weak measurements using Fano-type spectral response broadens the domain of applicability of weak measurements using natural spectral line shapes as a pointer in a wide range of physical systems.

A low power MICS band phase-locked loop for high resolution retinal prosthesis.

PubMed

Yang, Jiawei; Skafidas, Efstratios

2013-08-01

Ultra low power dissipation is essential in retinal prosthesis and many other biomedical implants. Extensive research has been undertaken in designing low power biomedical transceivers, however to date, most effort has been focused on low frequency inductive links. For higher frequency, more robust and more complex applications, such as Medical Implant Communication Service (MICS) band multichannel transceivers, power consumption remains high. This paper explores the design of micro-power data links at 400 MHz for a high resolution retinal prosthesis. By taking advantage of advanced small geometry CMOS technology and precise transistor-level modeling, we successfully utilized subthreshold FET operation, which has been historically limited to low frequency circuits due to the inadequate transistor operating speed in and near weak inversion; we have implemented a low power MICS transceiver. Particularly, a low power, MICS band multichannel phase-locked loop (PLL) that employs a subthreshold voltage controlled oscillator (VCO) and digital synchronous dividers has been implemented on a 65-nm CMOS. A design methodology is presented in detail with the demonstration of EKV model parameters extraction. This PLL provides 600- mVpp quadrature oscillations and exhibits a phase noise of -102 dBc/Hz at 200-kHz offset, while only consuming 430- μW from a 1-V supply. The VCO has a gain (KVCO) of 12 MHz/V and is designed to operate in the near-weak inversion region and consumes 220- μA DC current. The designed PLL has a core area of 0.54 mm(2). It satisfies all specifications of MICS band operation with the advantage of significant reduction in power which is crucial for high resolution retinal prosthesis.

Effect of Joule heating and current crowding on electromigration in mobile technology

NASA Astrophysics Data System (ADS)

Tu, K. N.; Liu, Yingxia; Li, Menglu

2017-03-01

In the present era of big data and internet of things, the use of microelectronic products in all aspects of our life is manifested by the ubiquitous presence of mobile devices as i-phones and wearable i-products. These devices are facing the need for higher power and greater functionality applications such as in i-health, yet they are limited by physical size. At the moment, software (Apps) is much ahead of hardware in mobile technology. To advance hardware, the end of Moore's law in two-dimensional integrated circuits can be extended by three-dimensional integrated circuits (3D ICs). The concept of 3D ICs has been with us for more than ten years. The challenge in 3D IC technology is dense packing by using both vertical and horizontal interconnections. Mass production of 3D IC devices is behind schedule due to cost because of low yield and uncertain reliability. Joule heating is serious in a dense structure because of heat generation and dissipation. A change of reliability paradigm has advanced from failure at a specific circuit component to failure at a system level weak-link. Currently, the electronic industry is introducing 3D IC devices in mainframe computers, where cost is not an issue, for the purpose of collecting field data of failure, especially the effect of Joule heating and current crowding on electromigration. This review will concentrate on the positive feedback between Joule heating and electromigration, resulting in an accelerated system level weak-link failure. A new driving force of electromigration, the electric potential gradient force due to current crowding, will be reviewed critically. The induced failure tends to occur in the low current density region.

Sedimentation rates in eastern North America reveal strong links between regional climate, depositional environments, and sediment accumulation

NASA Astrophysics Data System (ADS)

Goring, S. J.; McLachlan, J. S.; Jackson, S. T.; Blaauw, M.; Christen, J.; Marlon, J.; Blois, J.; Williams, J. W.

2011-12-01

PalEON is a multidisciplinary project that combines paleo and modern ecological data with state-of-the-art statistical and modelling tools to examine the interactions between climate, fire and vegetation during the past two millennia in the northeastern United States. A fundamental challenge for PalEON (and paleo research more broadly) is to improve age modelling to yield more accurate sediment-core chronologies. To address this challenge, we assessed sedimentation rates and their controls for 218 lakes and mires in the northeastern U.S. Sedimentation rates (yr/cm) were calculated from age-depth models, which were obtained from the Neotoma database (www.neotomadb.org) and other contributed pollen records. The age models were recalibrated to IntCal09 and augmented in some cases using biostratigraphic markers (Picea decline, 16 kcal BP - 10.5 kcal BP; Quercus rise, 12 - 9.1 kcal BP; and Alnus decline, 11.5 - 10.6 kcal BP) as described in Blois et al. (2011). Relationships between sedimentation rates and sediment age, site longitude, and depositional environment (lacustrine or mire) are significant but weak. There are clear and significant links between variations in the NGRIP record of δ18O and sedimentation in mires across the PalEON region, but no links to lacustrine sedimentation rates. This result indicates that super-regional climatic control of primary productivity, and thus autochthonic sediment deposition, dominates in mires while deposition in lacustrine basins may be driven primarily by local and regional factors including watershed size, surficial materials,and regional vegetation. The shape of the gamma probability functions that best describe sedimentation rate distributions are calculated and presented here for use as priors in Bayesian age modelling applications such as BACON (Blaauw and Christen, in press). Future applications of this research are also discussed.

DARPA Quantum Network Testbed

DTIC Science & Technology

2007-07-01

End-to-End Security with Photonic Switching...............................28 8.4 Year 3 – Adding a Link that implements Entanglement -Based QKD... entangled photon pairs at 1550nm. • Built a highspeed (~10 MHz) physical random number generator, and integrated it into Bob. This design provides an...each kind of photonic setup in the Quantum Network, i.e., over time it will grow to include descriptions of the weak-coherent link, the entangled

Emergence of bursts and communities in evolving weighted networks.

PubMed

Jo, Hang-Hyun; Pan, Raj Kumar; Kaski, Kimmo

2011-01-01

Understanding the patterns of human dynamics and social interaction and the way they lead to the formation of an organized and functional society are important issues especially for techno-social development. Addressing these issues of social networks has recently become possible through large scale data analysis of mobile phone call records, which has revealed the existence of modular or community structure with many links between nodes of the same community and relatively few links between nodes of different communities. The weights of links, e.g., the number of calls between two users, and the network topology are found correlated such that intra-community links are stronger compared to the weak inter-community links. This feature is known as Granovetter's "The strength of weak ties" hypothesis. In addition to this inhomogeneous community structure, the temporal patterns of human dynamics turn out to be inhomogeneous or bursty, characterized by the heavy tailed distribution of time interval between two consecutive events, i.e., inter-event time. In this paper, we study how the community structure and the bursty dynamics emerge together in a simple evolving weighted network model. The principal mechanisms behind these patterns are social interaction by cyclic closure, i.e., links to friends of friends and the focal closure, links to individuals sharing similar attributes or interests, and human dynamics by task handling process. These three mechanisms have been implemented as a network model with local attachment, global attachment, and priority-based queuing processes. By comprehensive numerical simulations we show that the interplay of these mechanisms leads to the emergence of heavy tailed inter-event time distribution and the evolution of Granovetter-type community structure. Moreover, the numerical results are found to be in qualitative agreement with empirical analysis results from mobile phone call dataset.

Knowing the SCOR: using business metrics to gain measurable improvements.

PubMed

Malin, Jane H

2006-07-01

By using the Supply Chain Operations Reference model, one New York hospital was able to define and measure its supply chains, determine the weak links in its processes, and identify necessary improvements.

Memory skills of deaf learners: implications and applications.

PubMed

Hamilton, Harley

2011-01-01

The author reviews research on working memory and short-term memory abilities of deaf individuals, delineating strengths and weaknesses. Among the areas of weakness that are reviewed are sequential recall, processing speed, attention, and memory load. Areas of strengths include free recall, visuospatial recall, imagery, and dual encoding. Phonological encoding and rehearsal appear to be strengths when these strategies are employed. The implications of the strengths and weaknesses for language learning and educational achievement are discussed. Research questions are posed, and remedial and compensatory classroom applications are suggested.

BROMODICHLOROMETHANE TOXICOKINETICS: LINKING METABOLISM TO EFFECT

EPA Science Inventory

Bromodichloromethane (BDCM), a trihalomethane (THM), is among the most prevalent disinfection byproducts found in chlorinated drinking water. Weak associations between THM exposure and cancers of the bladder and lower GI tract have been suggested by positive epidemiological s...

Stress and Aeronautical Team Decision Making: Strengthening the Weak Links

NASA Technical Reports Server (NTRS)

Orasanu, Judith; Rosekind, Mark R. (Technical Monitor)

1996-01-01

A model that characterizes pilots'decision making in flight will be presented. Elements of the model that appear most vulnerable to stress will be examined in light of accidents and incidents. The model includes two major components: Situation assessment and choice of a course of action. While based on Klein's Recognition-Primed Decision Making, it is tailored to the aviation environment which includes certain features that may be common to other domains: Primarily, aviation is highly proceduralized and options are generally well known. What appears to make decisions difficult are ambiguity, time pressure, and risk. In addition, decisions must often be made while carrying out the standard procedures of flight, including checklists, review of approach plates, standard briefings, and communication with air traffic controllers or cabin crew. The effects of stressors on decision making by pilots with varying levels of expertise will be explored, along with strategies for strengthening the weak links.

Stability in Real Food Webs: Weak Links in Long Loops

NASA Astrophysics Data System (ADS)

Neutel, Anje-Margriet; Heesterbeek, Johan A. P.; de Ruiter, Peter C.

2002-05-01

Increasing evidence that the strengths of interactions among populations in biological communities form patterns that are crucial for system stability requires clarification of the precise form of these patterns, how they come about, and why they influence stability. We show that in real food webs, interaction strengths are organized in trophic loops in such a way that long loops contain relatively many weak links. We show and explain mathematically that this patterning enhances stability, because it reduces maximum ``loop weight'' and thus reduces the amount of intraspecific interaction needed for matrix stability. The patterns are brought about by biomass pyramids, a feature common to most ecosystems. Incorporation of biomass pyramids in 104 food-web descriptions reveals that the low weight of the long loops stabilizes complex food webs. Loop-weight analysis could be a useful tool for exploring the structure and organization of complex communities.

Seebeck effect on a weak link between Fermi and non-Fermi liquids

NASA Astrophysics Data System (ADS)

Nguyen, T. K. T.; Kiselev, M. N.

2018-02-01

We propose a model describing Seebeck effect on a weak link between two quantum systems with fine-tunable ground states of Fermi and non-Fermi liquid origin. The experimental realization of the model can be achieved by utilizing the quantum devices operating in the integer quantum Hall regime [Z. Iftikhar et al., Nature (London) 526, 233 (2015), 10.1038/nature15384] designed for detection of macroscopic quantum charged states in multichannel Kondo systems. We present a theory of thermoelectric transport through hybrid quantum devices constructed from quantum-dot-quantum-point-contact building blocks. We discuss pronounced effects in the temperature and gate voltage dependence of thermoelectric power associated with a competition between Fermi and non-Fermi liquid behaviors. High controllability of the device allows to fine tune the system to different regimes described by multichannel and multi-impurity Kondo models.

2-(Naphthalen-1-yl)-4-(naphthalen-1-yl­methyl­idene)-1,3-oxazol-5(4H)-one

PubMed Central

Gündoğdu, Cevher; Alp, Serap; Ergün, Yavuz; Tercan, Barış; Hökelek, Tuncer

2011-01-01

In the title compound, C24H15NO2, the oxazole ring is oriented at dihedral angles of 10.09 (4) and 6.04 (4)° with respect to the mean planes of the naphthalene ring systems, while the two naphthalene ring systems make a dihedral angle of 4.32 (3)°. Intra­molecular C—H⋯N hydrogen bonds link the oxazole N atom to the naphthalene ring systems. In the crystal, inter­molecular weak C—H⋯O hydrogen bonds link the mol­ecules into centrosymmetric dimers. π–π contacts between the oxazole and naphthalene rings and between the naphthalene ring systems [centroid–centroid distances = 3.5947 (9) and 3.7981 (9) Å] may further stabilize the crystal structure. Three weak C—H⋯π inter­actions also occur. PMID:21754548

Children's success at detecting circular explanations and their interest in future learning.

PubMed

Mills, Candice M; Danovitch, Judith H; Rowles, Sydney P; Campbell, Ian L

2017-10-01

These studies explore elementary-school-aged children's ability to evaluate circular explanations and whether they respond to receiving weak explanations by expressing interest in additional learning. In the first study, 6-, 8-, and 10-year-olds (n = 53) heard why questions about unfamiliar animals. For each question, they rated the quality of single explanations and later selected the best explanation between pairs of circular and noncircular explanations. When judging single explanations, 8- and 10-year-olds, and to some extent 6-year-olds, provided higher ratings for noncircular explanations compared to circular ones. When selecting between pairs of explanations, all age groups preferred noncircular explanations to circular ones, but older children did so more consistently than 6-year-olds. Children who recognized the weakness of the single circular explanations were more interested in receiving additional information about the question topics. In Study 2, all three age groups (n = 87) provided higher ratings for noncircular explanations compared to circular ones when listening to responses to how questions, but older children showed a greater distinction in their ratings than 6-year-olds. Moreover, the link between recognizing circular explanations as weak and interest in future learning could not be accounted for solely by individual differences in verbal intelligence. These findings illustrate the developmental trajectory of explanation evaluation and support that recognition of weak explanations is linked to interest in future learning across the elementary years. Implications for education are discussed.

New Directions in Online Fraud

NASA Astrophysics Data System (ADS)

Mohatar, Oscar Delgado; Sierra Cámara, José M.

2007-12-01

The security of a system can be seen as a chain of protection methods, and the global level is just as strong as its weakest link. From this point of view, cryptography is no more than other link in the chain. And most of the times, it is probably the strongest link, but there are many others weak links which decrease the security level until unacceptable level for carrying out electronic commerce. In last term, exclusively technical protection methods seem not be able to completely resolve the situation. The focus should be changed towards trying to increase the resistance of the system, instead of its invulnerability that, in any case, can not be completely achieved in general purpose operating systems.

Novel high-performance scattering materials for use in energy-saving light fittings and skylights based on polymer pigmented with polymer

NASA Astrophysics Data System (ADS)

Smith, Geoffrey B.; Earp, Alan; Franklin, Jim B.; McCredie, Geoffrey

2001-11-01

Simple quantitative performance criteria are developed for translucent materials in terms of hemispherical visible transmittance, and angular spread of transmitted luminance using a half angle. Criteria are linked to applications in luminaires and skylights with emphasis on maximising visible throughput while minimising glare. These basic criteria are also extended to angle of incidence changes which are substantial. Example data is provided showing that acrylic pigmented with spherical polymer particles can have total hemispherical transmittance with weak thickness dependence, which is better than clear sheet, while the spread of transmitted light is quite thickness-sensitive and occurs over wider angles than inorganic pigments. This combination means significantly fewer lamps can achieve specified lux levels with low glare, and smaller skylights can provide higher, more uniform daylight illuminance.

Extreme electron polaron spatial delocalization in π-conjugated materials

DOE PAGES

Rawson, Jeff; Angiolillo, Paul J.; Therien, Michael J.

2015-10-28

The electron polaron, a spin-1/2 excitation, is the fundamental negative charge carrier in π-conjugated organic materials. Large polaron spatial dimensions result from weak electron-lattice coupling and thus identify materials with unusually low barriers for the charge transfer reactions that are central to electronic device applications. In this paper, we demonstrate electron polarons in π-conjugated multiporphyrin arrays that feature vast areal delocalization. This finding is evidenced by concurrent optical and electron spin resonance measurements, coupled with electronic structure calculations that suggest atypically small reorganization energies for one-electron reduction of these materials. Finally, because the electron polaron dimension can be linked tomore » key performance metrics in organic photovoltaics, light-emitting diodes, and a host of other devices, these findings identify conjugated materials with exceptional optical, electronic, and spintronic properties.« less

Gene therapy for inherited muscle diseases: where genetics meets rehabilitation medicine.

PubMed

Braun, Robynne; Wang, Zejing; Mack, David L; Childers, Martin K

2014-11-01

The development of clinical vectors to correct genetic mutations that cause inherited myopathies and related disorders of skeletal muscle is advancing at an impressive rate. Adeno-associated virus vectors are attractive for clinical use because (1) adeno-associated viruses do not cause human disease and (2) these vectors are able to persist for years. New vectors are now becoming available as gene therapy delivery tools, and recent preclinical experiments have demonstrated the feasibility, safety, and efficacy of gene therapy with adeno-associated virus for long-term correction of muscle pathology and weakness in myotubularin-deficient canine and murine disease models. In this review, recent advances in the application of gene therapies to treat inherited muscle disorders are presented, including Duchenne muscular dystrophy and x-linked myotubular myopathy. Potential areas for therapeutic synergies between rehabilitation medicine and genetics are also discussed.

Bridging, brokerage and betweenness

PubMed Central

Everett, Martin G.; Valente, Thomas W.

2017-01-01

Valente and Fujimoto (2010) proposed a measure of brokerage in networks based on Granovetter’s classic work on the strength of weak ties. Their paper identified the need for finding node-based measures of brokerage that consider the entire network structure, not just a node’s local environment. The measures they propose, aggregating the average change in cohesion for a node’s links, has several limitations. In this paper we review their method and show how the idea can be modified by using betweenness centrality as an underpinning concept. We explore the properties of the new method and provide point, normalized, and network level variations. This new approach has two advantages, first it provides a more robust means to normalize the measure to control for network size, and second, the modified measure is computationally less demanding making it applicable to larger networks. PMID:28239229

Negotiation from weakness: Concept, model, and application to strategic negotiations

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

Tangredi, S.J.

Analysis of the dynamics of asymmetrical negotiations requires the development of the novel concept of negotiation from weakness. A nation is assumed to be negotiating from weakness when the elements of national power place it at a relative disadvantage in achieving the desired objectives of a particular set of negotiations. Successful negotiation from weakness is the adoption and application of negotiating strategies and tactics (subjective elements) that nullify the possible effects of an asymmetry in objective power potential. Once developed, the model is applied to arms control negotiations between the United States and Soviet Union in 1962-1972, a period inmore » which the United States was assumed to be strategically superior. Outcomes of the arms control negotiations examined suggests that the Soviet Union attempted to utilize strategies and tactics appropriate to the negotiating from weakness situation. The success of the Soviet Union is reversing the perceived strategic balance by 1972, implies that the concept of successful negotiating from weakness is a viable approach to the examination of asymmetrical negotiations involving security issues.« less

The Top Quark, Its Discovery, and Subsequent Research

Science.gov Websites

theories of the strong, weak, and electromagnetic interactions and a wealth of experimental information had Subgroup, July 2006 The Collider Detector at Fermilab (CDF) Top Some links on this page may take you to non

Using Bayes to get the most out of non-significant results.

PubMed

Dienes, Zoltan

2014-01-01

No scientific conclusion follows automatically from a statistically non-significant result, yet people routinely use non-significant results to guide conclusions about the status of theories (or the effectiveness of practices). To know whether a non-significant result counts against a theory, or if it just indicates data insensitivity, researchers must use one of: power, intervals (such as confidence or credibility intervals), or else an indicator of the relative evidence for one theory over another, such as a Bayes factor. I argue Bayes factors allow theory to be linked to data in a way that overcomes the weaknesses of the other approaches. Specifically, Bayes factors use the data themselves to determine their sensitivity in distinguishing theories (unlike power), and they make use of those aspects of a theory's predictions that are often easiest to specify (unlike power and intervals, which require specifying the minimal interesting value in order to address theory). Bayes factors provide a coherent approach to determining whether non-significant results support a null hypothesis over a theory, or whether the data are just insensitive. They allow accepting and rejecting the null hypothesis to be put on an equal footing. Concrete examples are provided to indicate the range of application of a simple online Bayes calculator, which reveal both the strengths and weaknesses of Bayes factors.

Melnikov method approach to control of homoclinic/heteroclinic chaos by weak harmonic excitations.

PubMed

Chacón, Ricardo

2006-09-15

A review on the application of Melnikov's method to control homoclinic and heteroclinic chaos in low-dimensional, non-autonomous and dissipative oscillator systems by weak harmonic excitations is presented, including diverse applications, such as chaotic escape from a potential well, chaotic solitons in Frenkel-Kontorova chains and chaotic-charged particles in the field of an electrostatic wave packet.

Xilmass: A New Approach toward the Identification of Cross-Linked Peptides.

PubMed

Yılmaz, Şule; Drepper, Friedel; Hulstaert, Niels; Černič, Maša; Gevaert, Kris; Economou, Anastassios; Warscheid, Bettina; Martens, Lennart; Vandermarliere, Elien

2016-10-18

Chemical cross-linking coupled with mass spectrometry plays an important role in unravelling protein interactions, especially weak and transient ones. Moreover, cross-linking complements several structural determination approaches such as cryo-EM. Although several computational approaches are available for the annotation of spectra obtained from cross-linked peptides, there remains room for improvement. Here, we present Xilmass, a novel algorithm to identify cross-linked peptides that introduces two new concepts: (i) the cross-linked peptides are represented in the search database such that the cross-linking sites are explicitly encoded, and (ii) the scoring function derived from the Andromeda algorithm was adapted to score against a theoretical tandem mass spectrometry (MS/MS) spectrum that contains the peaks from all possible fragment ions of a cross-linked peptide pair. The performance of Xilmass was evaluated against the recently published Kojak and the popular pLink algorithms on a calmodulin-plectin complex data set, as well as three additional, published data sets. The results show that Xilmass typically had the highest number of identified distinct cross-linked sites and also the highest number of predicted cross-linked sites.

Advanced reliability modeling of fault-tolerant computer-based systems

NASA Technical Reports Server (NTRS)

Bavuso, S. J.

1982-01-01

Two methodologies for the reliability assessment of fault tolerant digital computer based systems are discussed. The computer-aided reliability estimation 3 (CARE 3) and gate logic software simulation (GLOSS) are assessment technologies that were developed to mitigate a serious weakness in the design and evaluation process of ultrareliable digital systems. The weak link is based on the unavailability of a sufficiently powerful modeling technique for comparing the stochastic attributes of one system against others. Some of the more interesting attributes are reliability, system survival, safety, and mission success.

(Z)-3-(1-Chloro-prop-1-en-yl)-2-methyl-1-phenyl-sulfonyl-1H-indole.

PubMed

Umadevi, M; Saravanan, V; Yamuna, R; Mohanakrishnan, A K; Chakkaravarthi, G

2013-11-16

In the title compound, C18H16ClNO2S, the indole ring system forms a dihedral angle of 75.07 (8)° with the phenyl ring. The mol-ecular structure is stabilized by a weak intra-molecular C-H⋯O hydrogen bond. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds, forming a chain along [10-1]. C-H⋯π inter-actions are also observed, leading to a three-dimensional network.

Detection of anticentromere antibodies using cloned autoantigen CENP-B.

PubMed

Rothfield, N; Whitaker, D; Bordwell, B; Weiner, E; Senecal, J L; Earnshaw, W

1987-12-01

A solid-phase enzyme-linked immunosorbent assay has been established using a cloned fusion protein, CtermCENP-B [beta-gal], as antigen. The fusion protein carries the major epitope of CENP-B, the major centromeric autoantigen. The enzyme-linked immunosorbent assay was more sensitive than immunofluorescence techniques in detecting anticentromere antibodies in patients with scleroderma or Raynaud's disease, and was weakly positive in 3% of normal controls and in 3% of 70 patients with other connective tissue diseases.

Cervical Spinal Cord Atrophy Profile in Adult SMN1-Linked SMA

PubMed Central

El Mendili, Mohamed-Mounir; Lenglet, Timothée; Stojkovic, Tanya; Behin, Anthony; Guimarães-Costa, Raquel; Salachas, François; Meininger, Vincent; Bruneteau, Gaelle; Le Forestier, Nadine; Laforêt, Pascal; Lehéricy, Stéphane; Benali, Habib; Pradat, Pierre-François

2016-01-01

Purpose The mechanisms underlying the topography of motor deficits in spinal muscular atrophy (SMA) remain unknown. We investigated the profile of spinal cord atrophy (SCA) in SMN1-linked SMA, and its correlation with the topography of muscle weakness. Materials and Methods Eighteen SMN1-linked SMA patients type III/V and 18 age/gender-matched healthy volunteers were included. Patients were scored on manual muscle testing and functional scales. Spinal cord was imaged using 3T MRI system. Radial distance (RD) and cord cross-sectional area (CSA) measurements in SMA patients were compared to those in controls and correlated with strength and disability scores. Results CSA measurements revealed a significant cord atrophy gradient mainly located between C3 and C6 vertebral levels with a SCA rate ranging from 5.4% to 23% in SMA patients compared to controls. RD was significantly lower in SMA patients compared to controls in the anterior-posterior direction with a maximum along C4 and C5 vertebral levels (p-values < 10−5). There were no correlations between atrophy measurements, strength and disability scores. Conclusions Spinal cord atrophy in adult SMN1-linked SMA predominates in the segments innervating the proximal muscles. Additional factors such as neuromuscular junction or intrinsic skeletal muscle defects may play a role in more complex mechanisms underlying weakness in these patients. PMID:27089520

Strong, weak, and missing links in a microbial community of the N.W. Mediterranean Sea.

PubMed

Bettarel, Y; Dolan, J R; Hornak, K; Lemée, R; Masin, M; Pedrotti, M-L; Rochelle-Newall, E; Simek, K; Sime-Ngando, T

2002-12-01

Planktonic microbial communities often appear stable over periods of days and thus tight links are assumed to exist between different functional groups (i.e. producers and consumers). We examined these links by characterizing short-term temporal correspondences in the concentrations and activities of microbial groups sampled from 1 m depth, at a coastal site of the N.W. Mediterranean Sea, in September 2001 every 3 h for 3 days. We estimated the abundance and activity rates of the autotrophic prokaryote Synechococcus, heterotrophic bacteria, viruses, heterotrophic nanoflagellates, as well as dissolved organic carbon concentrations. We found that Synechococcus, heterotrophic bacteria, and viruses displayed distinct patterns. Synechococcus abundance was greatest at midnight and lowest at 21:00 and showed the common pattern of an early evening maximum in dividing cells. In contrast, viral concentrations were minimal at midnight and maximal at 18:00. Viral infection of heterotrophic bacteria was rare (0.5-2.5%) and appeared to peak at 03:00. Heterotrophic bacteria, as % eubacteria-positive cells, peaked at midday, appearing loosely related to relative changes in dissolved organic carbon concentration. Bacterial production as assessed by leucine incorporation showed no consistent temporal pattern but could be related to shifts in the grazing rates of heterotrophic nanoflagellates and viral infection rates. Estimates of virus-induced mortality of heterotrophic bacteria, based on infection frequencies, were only about 10% of cell production. Overall, the dynamics of viruses appeared more closely related to Synechococcus than to heterotrophic bacteria. Thus, we found weak links between dissolved organic carbon concentration, or grazing, and bacterial activity, a possibly strong link between Synechococcus and viruses, and a missing link between light and viruses.

Cross-linking of type I collagen with microbial transglutaminase: identification of cross-linking sites.

PubMed

Stachel, Ines; Schwarzenbolz, Uwe; Henle, Thomas; Meyer, Michael

2010-03-08

Collagen is a popular biomaterial. To deal with its lack of thermal stability and its weak resistance to proteolytic degradation, collagen-based materials are stabilized via different cross-linking procedures. Regarding the potential toxicity of residual cross-linking agents, enzyme-mediated cross-linking would provide an alternative and nontoxic method for collagen stabilization. The results of this study show that type I collagen is a substrate for mTG. However, epsilon-(gamma-glutamyl)lysine cross-links are only incorporated at elevated temperatures when the protein is partially or completely denatured. A maximum number of 5.4 cross-links per collagen monomer were found for heat-denatured collagen. Labeling with the primary amine monodansylcadaverine revealed that at least half of the cross-links are located within the triple helical region of the collagen molecule. Because the triple helix is highly ordered in its native state, this finding might explain why the glutamine residues are inaccessible for mTG under nondenaturing conditions.

The strength of friendship ties in proximity sensor data.

PubMed

Sekara, Vedran; Lehmann, Sune

2014-01-01

Understanding how people interact and socialize is important in many contexts from disease control to urban planning. Datasets that capture this specific aspect of human life have increased in size and availability over the last few years. We have yet to understand, however, to what extent such electronic datasets may serve as a valid proxy for real life social interactions. For an observational dataset, gathered using mobile phones, we analyze the problem of identifying transient and non-important links, as well as how to highlight important social interactions. Applying the Bluetooth signal strength parameter to distinguish between observations, we demonstrate that weak links, compared to strong links, have a lower probability of being observed at later times, while such links-on average-also have lower link-weights and probability of sharing an online friendship. Further, the role of link-strength is investigated in relation to social network properties.

Evaluation of scour potential of cohesive soils : final report, August 2009.

DOT National Transportation Integrated Search

2009-08-01

Prediction of scour at bridge river crossings is an evolving process. Hydraulic models to estimate water velocity and, therefore, the shear stresses that erode soil are reasonably well developed. The weak link remains methods for estimating soil erod...

Genetics Home Reference: congenital cataracts, facial dysmorphism, and neuropathy

MedlinePlus

... sensory cells. This nerve damage is known as peripheral neuropathy. Weakness in the legs, followed by the arms, ... and Neuropathy MedlinePlus Encyclopedia: Congenital Cataract MedlinePlus Encyclopedia: Peripheral Neuropathy General Information from MedlinePlus (5 links) Diagnostic Tests ...

Highly biocompatible collagen-Delonix regia seed polysaccharide hybrid scaffolds for antimicrobial wound dressing.

PubMed

Cheirmadurai, Kalirajan; Thanikaivelan, Palanisamy; Murali, Ragothaman

2016-02-10

Biomaterials based entirely on biological resources are ideal for tissue engineering applications. Here we report the preparation of hybrid collagen scaffolds comprising gulmohar seed polysaccharide (GSP) and cinnamon bark extract as cross-linking agent. (1)H NMR spectrum of GSP confirms the presence of galactose and mannose in the ratio of 1:1.54, which was further corroborated using FT-IR. The hybrid scaffolds show better enzyme and thermal stability in contrast to pure collagen scaffold probably due to weak interactions from GSP and covalent interaction through cinnamaldehyde. Gas permeability and scanning electron microscopic analysis show that the porosity of the hybrid scaffolds is slightly reduced with the increase in the concentration of GSP. The infrared and circular dichroic spectral studies show that the secondary structure of the collagen did not change after the interaction with GSP and cinnamaldehyde. The hybrid scaffolds stabilized with cinnamaldehyde show good antimicrobial activity against the common multi-drug resistant wound pathogens. These results suggest that the prepared hybrid scaffolds have great potential for antimicrobial wound dressing applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stabilization of weak ferromagnetism by strong magnetic response to epitaxial strain in multiferroic BiFeO 3

DOE PAGES

Cooper, Valentino R.; Lee, Jun Hee; Krogel, Jaron T.; ...

2015-08-06

Multiferroic BiFeO 3 exhibits excellent magnetoelectric coupling critical for magnetic information processing with minimal power consumption. Thus, the degenerate nature of the easy spin axis in the (111) plane presents roadblocks for real world applications. Here, we explore the stabilization and switchability of the weak ferromagnetic moments under applied epitaxial strain using a combination of first-principles calculations and group-theoretic analyses. We demonstrate that the antiferromagnetic moment vector can be stabilized along unique crystallographic directions ([110] and [-110]) under compressive and tensile strains. A direct coupling between the anisotropic antiferrodistortive rotations and Dzyaloshinskii-Moria interactions drives the stabilization of weak ferromagnetism. Furthermore,more » energetically competing C- and G-type magnetic orderings are observed at high compressive strains, suggesting that it may be possible to switch the weak ferromagnetism on and off under application of strain. These findings emphasize the importance of strain and antiferrodistortive rotations as routes to enhancing induced weak ferromagnetism in multiferroic oxides.« less

Isogeometric Bézier dual mortaring: Refineable higher-order spline dual bases and weakly continuous geometry

NASA Astrophysics Data System (ADS)

Zou, Z.; Scott, M. A.; Borden, M. J.; Thomas, D. C.; Dornisch, W.; Brivadis, E.

2018-05-01

In this paper we develop the isogeometric B\\'ezier dual mortar method. It is based on B\\'ezier extraction and projection and is applicable to any spline space which can be represented in B\\'ezier form (i.e., NURBS, T-splines, LR-splines, etc.). The approach weakly enforces the continuity of the solution at patch interfaces and the error can be adaptively controlled by leveraging the refineability of the underlying dual spline basis without introducing any additional degrees of freedom. We also develop weakly continuous geometry as a particular application of isogeometric B\\'ezier dual mortaring. Weakly continuous geometry is a geometry description where the weak continuity constraints are built into properly modified B\\'ezier extraction operators. As a result, multi-patch models can be processed in a solver directly without having to employ a mortaring solution strategy. We demonstrate the utility of the approach on several challenging benchmark problems. Keywords: Mortar methods, Isogeometric analysis, B\\'ezier extraction, B\\'ezier projection

Broadband Microwave Wireless Power Transfer for Weak-Signal and Multipath Environments

NASA Technical Reports Server (NTRS)

Barton, Richard J.

2014-01-01

In this paper, we study the potential benefits of using relatively broadband wireless power transmission WPT strategies in both weak-signal and multipath environments where traditional narrowband strategies can be very inefficient. The paper is primarily a theoretical and analytical treatment of the problem that attempts to derive results that are widely applicable to many different WPT applications, including space solar power SSP.

Evaluation of 5 different labeled polymer immunohistochemical detection systems.

PubMed

Skaland, Ivar; Nordhus, Marit; Gudlaugsson, Einar; Klos, Jan; Kjellevold, Kjell H; Janssen, Emiel A M; Baak, Jan P A

2010-01-01

Immunohistochemical staining is important for diagnosis and therapeutic decision making but the results may vary when different detection systems are used. To analyze this, 5 different labeled polymer immunohistochemical detection systems, REAL EnVision, EnVision Flex, EnVision Flex+ (Dako, Glostrup, Denmark), NovoLink (Novocastra Laboratories Ltd, Newcastle Upon Tyne, UK) and UltraVision ONE (Thermo Fisher Scientific, Fremont, CA) were tested using 12 different, widely used mouse and rabbit primary antibodies, detecting nuclear, cytoplasmic, and membrane antigens. Serial sections of multitissue blocks containing 4% formaldehyde fixed paraffin embedded material were selected for their weak, moderate, and strong staining for each antibody. Specificity and sensitivity were evaluated by subjective scoring and digital image analysis. At optimal primary antibody dilution, digital image analysis showed that EnVision Flex+ was the most sensitive system (P < 0.005), with means of 8.3, 13.4, 20.2, and 41.8 gray scale values stronger staining than REAL EnVision, EnVision Flex, NovoLink, and UltraVision ONE, respectively. NovoLink was the second most sensitive system for mouse antibodies, but showed low sensitivity for rabbit antibodies. Due to low sensitivity, 2 cases with UltraVision ONE and 1 case with NovoLink stained false negatively. None of the detection systems showed any distinct false positivity, but UltraVision ONE and NovoLink consistently showed weak background staining both in negative controls and at optimal primary antibody dilution. We conclude that there are significant differences in sensitivity, specificity, costs, and total assay time in the immunohistochemical detection systems currently in use.

The Fourth Force in Nature. Part I

ERIC Educational Resources Information Center

Marshak, R. E.

1971-01-01

The properties of the weak force between the subatomic particles is described. The weak force is observed in the form of nuclear beta radioactivity. Applications are given to terrestrial and extraterrestrial phenomena. (TS)

Similarity indices based on link weight assignment for link prediction of unweighted complex networks

NASA Astrophysics Data System (ADS)

Liu, Shuxin; Ji, Xinsheng; Liu, Caixia; Bai, Yi

2017-01-01

Many link prediction methods have been proposed for predicting the likelihood that a link exists between two nodes in complex networks. Among these methods, similarity indices are receiving close attention. Most similarity-based methods assume that the contribution of links with different topological structures is the same in the similarity calculations. This paper proposes a local weighted method, which weights the strength of connection between each pair of nodes. Based on the local weighted method, six local weighted similarity indices extended from unweighted similarity indices (including Common Neighbor (CN), Adamic-Adar (AA), Resource Allocation (RA), Salton, Jaccard and Local Path (LP) index) are proposed. Empirical study has shown that the local weighted method can significantly improve the prediction accuracy of these unweighted similarity indices and that in sparse and weakly clustered networks, the indices perform even better.

Atmospheric turbulence effects on the performance of a free space optical link employing orbital angular momentum multiplexing.

PubMed

Ren, Yongxiong; Huang, Hao; Xie, Guodong; Ahmed, Nisar; Yan, Yan; Erkmen, Baris I; Chandrasekaran, Nivedita; Lavery, Martin P J; Steinhoff, Nicholas K; Tur, Moshe; Dolinar, Samuel; Neifeld, Mark; Padgett, Miles J; Boyd, Robert W; Shapiro, Jeffrey H; Willner, Alan E

2013-10-15

We experimentally investigate the performance of an orbital angular momentum (OAM) multiplexed free space optical (FSO) communication link through emulated atmospheric turbulence. The turbulence effects on the crosstalk and system power penalty of the FSO link are characterized. The experimental results show that the power of the transmitted OAM mode will tend to spread uniformly onto the neighboring mode in medium-to-strong turbulence, resulting in severe crosstalk at the receiver. The power penalty is found to exceed 10 dB in a weak-to-medium turbulence condition due to the turbulence-induced crosstalk and power fluctuation of the received signal.

The Integration of Small Satellites in Maritime Interdiction Operations (MIO)

DTIC Science & Technology

2012-09-01

Interdiction Operation, Networks, Ad-Hoc Networks, AISSat-1, Adaptation, Weak Links, Satellite Tool Kit ( STK ), Tactical Network Topology (TNT). 15. NUMBER...43 B. STK .................................................................................................... 47 1. STK Modeling of... STK ............................. 69 1. Create the Six Satellites ........................................................ 69 2. Create the Facility

A new application of high-efficient silver salts-based photocatalyst under natural indoor weak light for wastewater cleaning.

PubMed

Hua, Xia; Teng, Fei; Zhao, Yunxuan; Xu, Juan; Xu, Chuangye; Yang, Yang; Zhang, Qiqi; Paul, Shashi; Zhang, Yi; Chen, Mindong; Zhao, Xudong

2015-09-15

As a high-quantum-efficiency photocatalyst, the serious photo-corrosion of silver phosphate (Ag3PO4), limits the practical applications in water purification and challenges us. Herein, Ag3PO4 is found to have a high stability under natural indoor weak light irradiation, suggesting that we can employ it by adopting a new application strategy. In our studies, rhodamine B (RhB, cationic dye), methyl orange (MO, anionic dye) and RhB-MO mixture aqueous solutions are used as the probing reaction for the degradation of organic wastewater. It is found that RhB, MO and RhB-MO can be completely degraded after 28 h under natural indoor weak light irradiation, indicating that multi-component organic contaminants can be efficiently degraded by Ag3PO4 under natural indoor weak light irradiation. The density of natural indoor weak light is measured to be 72cd, which is merely one-thousandth of 300 W xenon lamp (68.2 × 10(3)cd). Most importantly, Ag3PO4 shows a high stability under natural indoor weak light irradiation, demonstrated by the formation of fairly rare Ag. Furthermore, we also investigate the influence of inorganic ions on organic dyes degradation. It shows that the Cl(-) and Cr(6+) ions with high concentrations in wastewater have significantly decreased the degradation rate. From the viewpoint of energy saving and stability, this study shows us that we can utilize the Ag-containing photocatalysts under natural indoor weak light, which could be extended to indoor air cleaning process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Weak values in collision theory

NASA Astrophysics Data System (ADS)

de Castro, Leonardo Andreta; Brasil, Carlos Alexandre; Napolitano, Reginaldo de Jesus

2018-05-01

Weak measurements have an increasing number of applications in contemporary quantum mechanics. They were originally described as a weak interaction that slightly entangled the translational degrees of freedom of a particle to its spin, yielding surprising results after post-selection. That description often ignores the kinetic energy of the particle and its movement in three dimensions. Here, we include these elements and re-obtain the weak values within the context of collision theory by two different approaches, and prove that the results are compatible with each other and with the results from the traditional approach. To provide a more complete description, we generalize weak values into weak tensors and use them to provide a more realistic description of the Stern-Gerlach apparatus.

Measuring Incompatible Observables by Exploiting Sequential Weak Values.

PubMed

Piacentini, F; Avella, A; Levi, M P; Gramegna, M; Brida, G; Degiovanni, I P; Cohen, E; Lussana, R; Villa, F; Tosi, A; Zappa, F; Genovese, M

2016-10-21

One of the most intriguing aspects of quantum mechanics is the impossibility of measuring at the same time observables corresponding to noncommuting operators, because of quantum uncertainty. This impossibility can be partially relaxed when considering joint or sequential weak value evaluation. Indeed, weak value measurements have been a real breakthrough in the quantum measurement framework that is of the utmost interest from both a fundamental and an applicative point of view. In this Letter, we show how we realized for the first time a sequential weak value evaluation of two incompatible observables using a genuine single-photon experiment. These (sometimes anomalous) sequential weak values revealed the single-operator weak values, as well as the local correlation between them.

Measuring Incompatible Observables by Exploiting Sequential Weak Values

NASA Astrophysics Data System (ADS)

Piacentini, F.; Avella, A.; Levi, M. P.; Gramegna, M.; Brida, G.; Degiovanni, I. P.; Cohen, E.; Lussana, R.; Villa, F.; Tosi, A.; Zappa, F.; Genovese, M.

2016-10-01

One of the most intriguing aspects of quantum mechanics is the impossibility of measuring at the same time observables corresponding to noncommuting operators, because of quantum uncertainty. This impossibility can be partially relaxed when considering joint or sequential weak value evaluation. Indeed, weak value measurements have been a real breakthrough in the quantum measurement framework that is of the utmost interest from both a fundamental and an applicative point of view. In this Letter, we show how we realized for the first time a sequential weak value evaluation of two incompatible observables using a genuine single-photon experiment. These (sometimes anomalous) sequential weak values revealed the single-operator weak values, as well as the local correlation between them.

Weak interactions, omnivory and emergent food-web properties.

PubMed

Emmerson, Mark; Yearsley, Jon M

2004-02-22

Empirical studies have shown that, in real ecosystems, species-interaction strengths are generally skewed in their distribution towards weak interactions. Some theoretical work also suggests that weak interactions, especially in omnivorous links, are important for the local stability of a community at equilibrium. However, the majority of theoretical studies use uniform distributions of interaction strengths to generate artificial communities for study. We investigate the effects of the underlying interaction-strength distribution upon the return time, permanence and feasibility of simple Lotka-Volterra equilibrium communities. We show that a skew towards weak interactions promotes local and global stability only when omnivory is present. It is found that skewed interaction strengths are an emergent property of stable omnivorous communities, and that this skew towards weak interactions creates a dynamic constraint maintaining omnivory. Omnivory is more likely to occur when omnivorous interactions are skewed towards weak interactions. However, a skew towards weak interactions increases the return time to equilibrium, delays the recovery of ecosystems and hence decreases the stability of a community. When no skew is imposed, the set of stable omnivorous communities shows an emergent distribution of skewed interaction strengths. Our results apply to both local and global concepts of stability and are robust to the definition of a feasible community. These results are discussed in the light of empirical data and other theoretical studies, in conjunction with their broader implications for community assembly.

Crystal structure of (E)-4-hy-droxy-N'-(3-meth-oxy-benzyl-idene)benzohydrazide.

PubMed

Chantrapromma, Suchada; Prachumrat, Patcharawadee; Ruanwas, Pumsak; Boonnak, Nawong; Kassim, Mohammad B

2016-09-01

The title compound, C 15 H 14 N 2 O 3 , crystallizes with two independent mol-ecules ( A and B ) in the asymmetric unit that differ in the orientation of the 3-meth-oxy-phenyl group with respect to the methyl-idenebenzohydrazide unit. The dihedral angles between the two benzene rings are 24.02 (10) and 29.30 (9)° in mol-ecules A and B , respectively. In mol-ecule A , the meth-oxy group is twisted slightly relative to its bound benzene ring, with a C meth-yl -O-C-C torsion angle of 14.2 (3)°, whereas it is almost co-planar in mol-ecule B , where the corresponding angle is -2.4 (3)°. In the crystal, the mol-ecules are linked by N-H⋯O, O-H⋯N and O-H⋯O hydrogen bonds, as well as by weak C-H⋯O inter-actions, forming sheets parallel to the bc plane. The N-H⋯O hydrogen bond and weak C-H⋯O inter-action link different mol-ecules ( A ⋯ B ) whereas both O-H⋯N and O-H⋯O hydrogen bonds link like mol-ecules ( A ⋯ A ) and ( B ⋯ B ). Pairs of inversion-related B mol-ecules are stacked approximately along the a axis by π-π inter-actions in which the distance between the centroids of the 3-meth-oxy-phenyl rings is 3.5388 (12) Å. The B mol-ecules also participate in weak C-H⋯π inter-actions between the 4-hy-droxy-phenyl and the 3-meth-oxy-phenyl rings.

Weak links in high critical temperature superconductors

NASA Astrophysics Data System (ADS)

Tafuri, Francesco; Kirtley, John R.

2005-11-01

The traditional distinction between tunnel and highly transmissive barriers does not currently hold for high critical temperature superconducting Josephson junctions, both because of complicated materials issues and the intrinsic properties of high temperature superconductors (HTS). An intermediate regime, typical of both artificial superconductor-barrier-superconductor structures and of grain boundaries, spans several orders of magnitude in the critical current density and specific resistivity. The physics taking place at HTS surfaces and interfaces is rich, primarily because of phenomena associated with d-wave order parameter (OP) symmetry. These phenomena include Andreev bound states, the presence of the second harmonic in the critical current versus phase relation, a doubly degenerate state, time reversal symmetry breaking and the possible presence of an imaginary component of the OP. All these effects are regulated by a series of transport mechanisms, whose rules of interplay and relative activation are unknown. Some transport mechanisms probably have common roots, which are not completely clear and possibly related to the intrinsic nature of high-TC superconductivity. The d-wave OP symmetry gives unique properties to HTS weak links, which do not have any analogy with systems based on other superconductors. Even if the HTS structures are not optimal, compared with low critical temperature superconductor Josephson junctions, the state of the art allows the realization of weak links with unexpectedly high quality quantum properties, which open interesting perspectives for the future. The observation of macroscopic quantum tunnelling and the qubit proposals represent significant achievements in this direction. In this review we attempt to encompass all the above aspects, attached to a solid experimental basis of junction concepts and basic properties, along with a flexible phenomenological background, which collects ideas on the Josephson effect in the presence of d-wave pairing for different types of barriers.

It's the recipient that counts: spending money on strong social ties leads to greater happiness than spending on weak social ties.

PubMed

Aknin, Lara B; Sandstrom, Gillian M; Dunn, Elizabeth W; Norton, Michael I

2011-02-10

Previous research has shown that spending money on others (prosocial spending) increases happiness. But, do the happiness gains depend on who the money is spent on? Sociologists have distinguished between strong ties with close friends and family and weak ties--relationships characterized by less frequent contact, lower emotional intensity, and limited intimacy. We randomly assigned participants to reflect on a time when they spent money on either a strong social tie or a weak social tie. Participants reported higher levels of positive affect after recalling a time they spent on a strong tie versus a weak tie. The level of intimacy in the relationship was more important than the type of relationship; there was no significant difference in positive affect after recalling spending money on a family member instead of a friend. These results add to the growing literature examining the factors that moderate the link between prosocial behaviour and happiness.

Structure-directing weak phosphoryl XH...O=P (X = C, N) hydrogen bonds in cyclic oxazaphospholidines and oxazaphosphinanes.

PubMed

van der Lee, A; Rolland, M; Marat, X; Virieux, D; Volle, J N; Pirat, J L

2008-04-01

The structures of six cyclic oxazaphospholidines and three cyclic oxazaphosphinanes have been determined and their supramolecular structures have been compared. The molecules differ with respect to the functional groups attached to the central five- or six-membered rings, but have one phosphoryl group in common. The predominant feature in the supramolecular structures is the existence of relatively weak intermolecular phosphoryl XH...O=P (X = C, N) hydrogen bonds, creating in nearly all cases linear zigzag or double molecular chains. The molecular chains are in general linked to each other via very weak CH...pi or usual hydrogen-bond interactions. A survey of the Cambridge Structural Database on similar XH...O=P interactions shows a very large flexibility of the XH...O angle, which is in agreement with the DFT calculation reported elsewhere. The strength of the XH...O=P interaction can therefore be considered as relatively weak to moderately strong, and is expected to play at least a role in the formation of secondary substructures.

Higher criticism thresholding: Optimal feature selection when useful features are rare and weak.

PubMed

Donoho, David; Jin, Jiashun

2008-09-30

In important application fields today-genomics and proteomics are examples-selecting a small subset of useful features is crucial for success of Linear Classification Analysis. We study feature selection by thresholding of feature Z-scores and introduce a principle of threshold selection, based on the notion of higher criticism (HC). For i = 1, 2, ..., p, let pi(i) denote the two-sided P-value associated with the ith feature Z-score and pi((i)) denote the ith order statistic of the collection of P-values. The HC threshold is the absolute Z-score corresponding to the P-value maximizing the HC objective (i/p - pi((i)))/sqrt{i/p(1-i/p)}. We consider a rare/weak (RW) feature model, where the fraction of useful features is small and the useful features are each too weak to be of much use on their own. HC thresholding (HCT) has interesting behavior in this setting, with an intimate link between maximizing the HC objective and minimizing the error rate of the designed classifier, and very different behavior from popular threshold selection procedures such as false discovery rate thresholding (FDRT). In the most challenging RW settings, HCT uses an unconventionally low threshold; this keeps the missed-feature detection rate under better control than FDRT and yields a classifier with improved misclassification performance. Replacing cross-validated threshold selection in the popular Shrunken Centroid classifier with the computationally less expensive and simpler HCT reduces the variance of the selected threshold and the error rate of the constructed classifier. Results on standard real datasets and in asymptotic theory confirm the advantages of HCT.

Higher criticism thresholding: Optimal feature selection when useful features are rare and weak

PubMed Central

Donoho, David; Jin, Jiashun

2008-01-01

In important application fields today—genomics and proteomics are examples—selecting a small subset of useful features is crucial for success of Linear Classification Analysis. We study feature selection by thresholding of feature Z-scores and introduce a principle of threshold selection, based on the notion of higher criticism (HC). For i = 1, 2, …, p, let πi denote the two-sided P-value associated with the ith feature Z-score and π(i) denote the ith order statistic of the collection of P-values. The HC threshold is the absolute Z-score corresponding to the P-value maximizing the HC objective (i/p − π(i))/i/p(1−i/p). We consider a rare/weak (RW) feature model, where the fraction of useful features is small and the useful features are each too weak to be of much use on their own. HC thresholding (HCT) has interesting behavior in this setting, with an intimate link between maximizing the HC objective and minimizing the error rate of the designed classifier, and very different behavior from popular threshold selection procedures such as false discovery rate thresholding (FDRT). In the most challenging RW settings, HCT uses an unconventionally low threshold; this keeps the missed-feature detection rate under better control than FDRT and yields a classifier with improved misclassification performance. Replacing cross-validated threshold selection in the popular Shrunken Centroid classifier with the computationally less expensive and simpler HCT reduces the variance of the selected threshold and the error rate of the constructed classifier. Results on standard real datasets and in asymptotic theory confirm the advantages of HCT. PMID:18815365

Towards an analytical theory of social change: the case of China.

PubMed

Liu, Serena

2006-09-01

Lockwood argues that contradiction between the core institutional order and the material substructure of a society gives rise to potential social relationships which constitute a threat to the existing institutional order and may lead to change in the type of the society. Parkin, in particular, has advocated the application of the idea to the study of socialist societies. However, the situation of socialist China opposes Lockwood's view in that the new social relationships arising from the changing economic system do not pose a threat to the existing political system. Moreover, Lockwood underdevelops the connection between human action and social structure and does not theorize the mechanism linking system weakness and social change. This article formulates an alternative perspective by building on Giddens's structuration theory and Mouzelis's work on sociological theory. The theoretical framework is applied to China to give a flavour of how social change can be studied.

Self-Oscillating Josephson Quantum Heat Engine

NASA Astrophysics Data System (ADS)

Marchegiani, G.; Virtanen, P.; Giazotto, F.; Campisi, M.

2016-11-01

The design of a mesoscopic self-oscillating heat engine that works thanks to purely quantum effects is presented. The proposed scheme is amenable to experimental implementation with current state-of-the-art nanotechnology and materials. One of the main features of the structure is its versatility: The engine can deliver work to a generic load without galvanic contact. This versatility makes it a promising building block for low-temperature on-chip energy-management applications. The heat engine consists of a circuit featuring a thermoelectric element based on a ferromagnetic insulator-superconductor tunnel junction and a Josephson weak link that realizes a purely quantum dc-ac converter. This makeup enables the contactless transfer of work to the load (a generic RL circuit). The performance of the heat engine is investigated as a function of the thermal gradient applied to the thermoelectric junction. Power up to 1 pW can be delivered to a load RL=10 Ω .

Leveraging Social Links for Trust and Privacy in Networks

NASA Astrophysics Data System (ADS)

Cutillo, Leucio Antonio; Molva, Refik; Strufe, Thorsten

Existing on-line social networks (OSN) such as Facebook suffer from several weaknesses regarding privacy and security due to their inherent handling of personal data. As pointed out in [4], a preliminary analysis of existing OSNs shows that they are subject to a number of vulnerabilities, ranging from cloning legitimate users to sybil attacks through privacy violations. Starting from these OSN vulnerabilities as the first step of a broader research activity, we came up with a new approach that is very promising in re-visiting security and privacy problems in distributed systems and networks. We suggest a solution that both aims at avoiding any centralized control and leverages on the real life trust between users, that is part of the social network application itself. An anonymization technique based on multi-hop routing among trusted nodes guarantees privacy in data access and, generally speaking, in all the OSN operations.

Application of double-hybrid density functionals to charge transfer in N-substituted pentacenequinones.

PubMed

Sancho-García, J C

2012-05-07

A set of N-heteroquinones, deriving from oligoacenes, have been recently proposed as n-type organic semiconductors with high electron mobilities in thin-film transistors. Generally speaking, this class of compounds self-assembles in neighboring π-stacks linked by weak hydrogen bonds. We aim at theoretically characterizing here the sequential charge transport (hopping) process expected to take place across these arrays of molecules. To do so, we need to accurately address the preferred packing of these materials simultaneously to single-molecule properties related to charge-transfer events, carefully employing dispersion-corrected density functional theory methods to accurately extract the key molecular parameters governing this phenomenon at the nanoscale. This study confirms the great deal of interest around these compounds, since controlled functionalization of model molecules (i.e., pentacene) allows to efficiently tune the corresponding charge mobilities, and the capacity of modern quantum-chemical methods to predict it after rationalizing the underlying structure-property relationships.

A Review on the Bioinformatics Tools for Neuroimaging

PubMed Central

MAN, Mei Yen; ONG, Mei Sin; Mohamad, Mohd Saberi; DERIS, Safaai; SULONG, Ghazali; YUNUS, Jasmy; CHE HARUN, Fauzan Khairi

2015-01-01

Neuroimaging is a new technique used to create images of the structure and function of the nervous system in the human brain. Currently, it is crucial in scientific fields. Neuroimaging data are becoming of more interest among the circle of neuroimaging experts. Therefore, it is necessary to develop a large amount of neuroimaging tools. This paper gives an overview of the tools that have been used to image the structure and function of the nervous system. This information can help developers, experts, and users gain insight and a better understanding of the neuroimaging tools available, enabling better decision making in choosing tools of particular research interest. Sources, links, and descriptions of the application of each tool are provided in this paper as well. Lastly, this paper presents the language implemented, system requirements, strengths, and weaknesses of the tools that have been widely used to image the structure and function of the nervous system. PMID:27006633

Status of high temperature superconductor development for accelerator magnets

NASA Technical Reports Server (NTRS)

Hirabayashi, H.

1995-01-01

High temperature superconductors are still under development for various applications. As far as conductors for magnets are concerned, the development has just been started. Small coils wound by silver sheathed Bi-2212 and Bi-2223 oxide conductors have been reported by a few authors. Essential properties of high T(sub c) superconductors like pinning force, coherent length, intergrain coupling, weak link, thermal property, AC loss and mechanical strength are still not sufficiently understandable. In this talk, a review is given with comparison between the present achievement and the final requirement for high T(sub c) superconductors, which could be particularly used in accelerator magnets. Discussions on how to develop high T(sub c) superconductors for accelerator magnets are included with key parameters of essential properties. A proposal of how to make a prototype accelerator magnet with high T(sub c) superconductors with prospect for future development is also given.

Ultra-weak photon emission as a non-invasive tool for monitoring of oxidative processes in the epidermal cells of human skin: comparative study on the dorsal and the palm side of the hand.

PubMed

Rastogi, Anshu; Pospísil, Pavel

2010-08-01

All living organisms emit spontaneous ultra-weak photon emission as a result of cellular metabolic processes. Exposure of living organisms to exogenous factors results in oxidative processes and enhancement in ultra-weak photon emission. Here, hydrogen peroxide (H(2)O(2)), as a strongly oxidizing molecule, was used to induce oxidative processes and enhance ultra-weak photon emission in human hand skin. The presented work intends to compare both spontaneous and peroxide-induced ultra-weak photon emission from the epidermal cells on the dorsal and the palm side of the hand. A highly sensitive photomultiplier tube and a charge-coupled device camera were used to detect ultra-weak photon emission from human hand skin. Spontaneous ultra-weak photon emission from the epidermal cells on the dorsal side of the hand was 4 counts/s. Topical application of 500 mM H(2)O(2) to the dorsal side of the hand caused enhancement in ultra-weak photon emission to 40 counts/s. Interestingly, both spontaneous and peroxide-induced ultra-weak photon emission from the epidermal cells on the palm side of the hand were observed to increase twice their values, i.e. 8 and 80 counts/s, respectively. Similarly, the two-dimensional image of ultra-weak photon emission observed after topical application of H(2)O(2) to human skin reveals that photon emission from the palm side exceeds the photon emission from the dorsal side of the hand. The results presented indicate that the ultra-weak photon emission originating from the epidermal cells on the dorsal and the palm side of the hand is related to the histological structure of the human hand skin. Ultra-weak photon emission is shown as a non-destructive technique for monitoring of oxidative processes in the epidermal cells of the human hand skin and as a diagnostic tool for skin diseases.

Model reduction in mathematical pharmacology : Integration, reduction and linking of PBPK and systems biology models.

PubMed

Snowden, Thomas J; van der Graaf, Piet H; Tindall, Marcus J

2018-03-26

In this paper we present a framework for the reduction and linking of physiologically based pharmacokinetic (PBPK) models with models of systems biology to describe the effects of drug administration across multiple scales. To address the issue of model complexity, we propose the reduction of each type of model separately prior to being linked. We highlight the use of balanced truncation in reducing the linear components of PBPK models, whilst proper lumping is shown to be efficient in reducing typically nonlinear systems biology type models. The overall methodology is demonstrated via two example systems; a model of bacterial chemotactic signalling in Escherichia coli and a model of extracellular regulatory kinase activation mediated via the extracellular growth factor and nerve growth factor receptor pathways. Each system is tested under the simulated administration of three hypothetical compounds; a strong base, a weak base, and an acid, mirroring the parameterisation of pindolol, midazolam, and thiopental, respectively. Our method can produce up to an 80% decrease in simulation time, allowing substantial speed-up for computationally intensive applications including parameter fitting or agent based modelling. The approach provides a straightforward means to construct simplified Quantitative Systems Pharmacology models that still provide significant insight into the mechanisms of drug action. Such a framework can potentially bridge pre-clinical and clinical modelling - providing an intermediate level of model granularity between classical, empirical approaches and mechanistic systems describing the molecular scale.

4π-periodic Josephson supercurrent in HgTe-based topological Josephson junctions

PubMed Central

Wiedenmann, J.; Bocquillon, E.; Deacon, R. S.; Hartinger, S.; Herrmann, O.; Klapwijk, T. M.; Maier, L.; Ames, C.; Brüne, C.; Gould, C.; Oiwa, A.; Ishibashi, K.; Tarucha, S.; Buhmann, H.; Molenkamp, L. W.

2016-01-01

The Josephson effect describes the generic appearance of a supercurrent in a weak link between two superconductors. Its exact physical nature deeply influences the properties of the supercurrent. In recent years, considerable efforts have focused on the coupling of superconductors to the surface states of a three-dimensional topological insulator. In such a material, an unconventional induced p-wave superconductivity should occur, with a doublet of topologically protected gapless Andreev bound states, whose energies vary 4π-periodically with the superconducting phase difference across the junction. In this article, we report the observation of an anomalous response to rf irradiation in a Josephson junction made of a HgTe weak link. The response is understood as due to a 4π-periodic contribution to the supercurrent, and its amplitude is compatible with the expected contribution of a gapless Andreev doublet. Our work opens the way to more elaborate experiments to investigate the induced superconductivity in a three-dimensional insulator. PMID:26792013

See–saw relationship of the Holocene East Asian–Australian summer monsoon

PubMed Central

Eroglu, Deniz; McRobie, Fiona H.; Ozken, Ibrahim; Stemler, Thomas; Wyrwoll, Karl-Heinz; Breitenbach, Sebastian F. M.; Marwan, Norbert; Kurths, Jürgen

2016-01-01

The East Asian–Indonesian–Australian summer monsoon (EAIASM) links the Earth's hemispheres and provides a heat source that drives global circulation. At seasonal and inter-seasonal timescales, the summer monsoon of one hemisphere is linked via outflows from the winter monsoon of the opposing hemisphere. Long-term phase relationships between the East Asian summer monsoon (EASM) and the Indonesian–Australian summer monsoon (IASM) are poorly understood, raising questions of long-term adjustments to future greenhouse-triggered climate change and whether these changes could ‘lock in' possible IASM and EASM phase relationships in a region dependent on monsoonal rainfall. Here we show that a newly developed nonlinear time series analysis technique allows confident identification of strong versus weak monsoon phases at millennial to sub-centennial timescales. We find a see–saw relationship over the last 9,000 years—with strong and weak monsoons opposingly phased and triggered by solar variations. Our results provide insights into centennial- to millennial-scale relationships within the wider EAIASM regime. PMID:27666662

See-saw relationship of the Holocene East Asian-Australian summer monsoon.

PubMed

Eroglu, Deniz; McRobie, Fiona H; Ozken, Ibrahim; Stemler, Thomas; Wyrwoll, Karl-Heinz; Breitenbach, Sebastian F M; Marwan, Norbert; Kurths, Jürgen

2016-09-26

The East Asian-Indonesian-Australian summer monsoon (EAIASM) links the Earth's hemispheres and provides a heat source that drives global circulation. At seasonal and inter-seasonal timescales, the summer monsoon of one hemisphere is linked via outflows from the winter monsoon of the opposing hemisphere. Long-term phase relationships between the East Asian summer monsoon (EASM) and the Indonesian-Australian summer monsoon (IASM) are poorly understood, raising questions of long-term adjustments to future greenhouse-triggered climate change and whether these changes could 'lock in' possible IASM and EASM phase relationships in a region dependent on monsoonal rainfall. Here we show that a newly developed nonlinear time series analysis technique allows confident identification of strong versus weak monsoon phases at millennial to sub-centennial timescales. We find a see-saw relationship over the last 9,000 years-with strong and weak monsoons opposingly phased and triggered by solar variations. Our results provide insights into centennial- to millennial-scale relationships within the wider EAIASM regime.

Sensor/amplifier for weak light sources

NASA Technical Reports Server (NTRS)

Desmet, D. J.; Jason, A. J.; Parr, A. C.

1980-01-01

Light sensor/amplifier circuit detects weak light converts it into strong electrical signal in electrically noisy environment. Circuit is relatively simple and uses inexpensive, readily available components. Device is useful in such applications as fire detection and photographic processing.

Differentiating weak ties and strong ties among external sources of influences for enterprise resource planning (ERP) adoption

NASA Astrophysics Data System (ADS)

Aubert, Benoit; Léger, Pierre-Majorique; Larocque, Denis

2012-05-01

Enterprise resource planning (ERP) systems represent a major IT adoption decision. ERP adoption decisions, in the chemicals and allied products sectors, were examined between 1994 and 2005. Networks of strong ties and weak ties partners are investigated. Results show that neighbouring companies linked with strong ties can have an influence on organisations making such adoption decision. Past decisions made by major trading partners have a significant influence on the decision to adopt an ERP system for a given organisation. This reflects the complex nature of the knowledge required for such adoption.

Diethyl [(4-bromo­phen­yl)(5-chloro-2-hydroxy­anilino)meth­yl]phospho­nate

PubMed Central

Babu, V. H. H. Surendra; Krishnaiah, M.; Prasad, G. Syam; C. Suresh Reddy; Kant, Rajni

2009-01-01

In the title compound, C17H20BrClNO4P, inter­molecular C—H⋯O and N—H⋯O hydrogen bonds form centrosymmetric R 2 2(10) dimers linked through O—H⋯O inter­molecular hydrogen bonds, which form centrosymmetric R 2 2(16) dimers. All these hydrogen bonds form chains along [010]. In addition, the crystal structure is stabilized by weak C—H⋯Br hydrogen bonds. The very weak intramolecular N—H⋯O interaction forms a five-membered ring. PMID:21578446

Identification of interfaces involved in weak interactions with application to F-actin-aldolase rafts.

PubMed

Hu, Guiqing; Taylor, Dianne W; Liu, Jun; Taylor, Kenneth A

2018-03-01

Macromolecular interactions occur with widely varying affinities. Strong interactions form well defined interfaces but weak interactions are more dynamic and variable. Weak interactions can collectively lead to large structures such as microvilli via cooperativity and are often the precursors of much stronger interactions, e.g. the initial actin-myosin interaction during muscle contraction. Electron tomography combined with subvolume alignment and classification is an ideal method for the study of weak interactions because a 3-D image is obtained for the individual interactions, which subsequently are characterized collectively. Here we describe a method to characterize heterogeneous F-actin-aldolase interactions in 2-D rafts using electron tomography. By forming separate averages of the two constituents and fitting an atomic structure to each average, together with the alignment information which relates the raw motif to the average, an atomic model of each crosslink is determined and a frequency map of contact residues is computed. The approach should be applicable to any large structure composed of constituents that interact weakly and heterogeneously. Copyright © 2017 Elsevier Inc. All rights reserved.

METCAN simulation of candidate metal matrix composites for high temperature applications

NASA Technical Reports Server (NTRS)

Lee, Ho-Jun

1990-01-01

The METCAN (Metal Matrix Composite Analyzer) computer code is used to simulate the nonlinear behavior of select metal matrix composites in order to assess their potential for high temperature structural applications. Material properties for seven composites are generated at a fiber volume ratio of 0.33 for two bonding conditions (a perfect bond and a weak interphase case) at various temperatures. A comparison of the two bonding conditions studied shows a general reduction in value of all properties (except CTE) for the weak interphase case from the perfect bond case. However, in the weak interphase case, the residual stresses that develop are considerably less than those that form in the perfect bond case. Results of the computational simulation indicate that among the metal matrix composites examined, SiC/NiAl is the best candidate for high temperature applications at the given fiber volume ratio.

Intrinsically shunted Josephson junctions for electronics applications

NASA Astrophysics Data System (ADS)

Belogolovskii, M.; Zhitlukhina, E.; Lacquaniti, V.; De Leo, N.; Fretto, M.; Sosso, A.

2017-07-01

Conventional Josephson metal-insulator-metal devices are inherently underdamped and exhibit hysteretic current-voltage response due to a very high subgap resistance compared to that in the normal state. At the same time, overdamped junctions with single-valued characteristics are needed for most superconducting digital applications. The usual way to overcome the hysteretic behavior is to place an external low-resistance normal-metal shunt in parallel with each junction. Unfortunately, such solution results in a considerable complication of the circuitry design and introduces parasitic inductance through the junction. This paper provides a concise overview of some generic approaches that have been proposed in order to realize internal shunting in Josephson heterostructures with a barrier that itself contains the desired resistive component. The main attention is paid to self-shunted devices with local weak-link transmission probabilities that are so strongly disordered in the interface plane that transmission probabilities are tiny for the main part of the transition region between two super-conducting electrodes, while a small part of the interface is well transparent. We discuss the possibility of realizing a universal bimodal distribution function and emphasize advantages of such junctions that can be considered as a new class of self-shunted Josephson devices promising for practical applications in superconducting electronics operating at 4.2 K.

Disentangling effects of abiotic factors and biotic interactions on cross-taxon congruence in species turnover patterns of plants, moths and beetles.

PubMed

Duan, Meichun; Liu, Yunhui; Yu, Zhenrong; Baudry, Jacques; Li, Liangtao; Wang, Changliu; Axmacher, Jan C

2016-04-01

High cross-taxon congruence in species diversity patterns is essential for the use of surrogate taxa in biodiversity conservation, but presence and strength of congruence in species turnover patterns, and the relative contributions of abiotic environmental factors and biotic interaction towards this congruence, remain poorly understood. In our study, we used variation partitioning in multiple regressions to quantify cross-taxon congruence in community dissimilarities of vascular plants, geometrid and arciinid moths and carabid beetles, subsequently investigating their respective underpinning by abiotic factors and biotic interactions. Significant cross-taxon congruence observed across all taxon pairs was linked to their similar responses towards elevation change. Changes in the vegetation composition were closely linked to carabid turnover, with vegetation structure and associated microclimatic conditions proposed causes of this link. In contrast, moth assemblages appeared to be dominated by generalist species whose turnover was weakly associated with vegetation changes. Overall, abiotic factors exerted a stronger influence on cross-taxon congruence across our study sites than biotic interactions. The weak congruence in turnover observed particularly between plants and moths highlights the importance of multi-taxon approaches based on groupings of taxa with similar turnovers, rather than the use of single surrogate taxa or environmental proxies, in biodiversity assessments.

Crystal structure of 3-{[4-(2-meth-oxy-phen-yl)piperazin-1-yl]meth-yl}-5-(thio-phen-2-yl)-1,3,4-oxa-diazole-2(3H)-thione.

PubMed

Al-Alshaikh, Monirah A; Abuelizz, Hatem A; El-Emam, Ali A; Abdelbaky, Mohammed S M; Garcia-Granda, Santiago

2016-02-01

The title compound, C18H20N4O2S2, is a new 1,3,4-oxa-diazole and a key pharmacophore of several biologically active agents. It is composed of a meth-yl(thio-phen-2-yl)-1,3,4-oxa-diazole-2(3H)-thione moiety linked to a 2-meth-oxy-phenyl unit via a piperazine ring that has a chair conformation. The thio-phene ring mean plane lies almost in the plane of the oxa-diazole ring, with a dihedral angle of 4.35 (9)°. The 2-meth-oxy-phenyl ring is almost normal to the oxa-diazole ring, with a dihedral angle of 84.17 (10)°. In the crystal, mol-ecules are linked by weak C-H⋯S hydrogen bonds and C-H⋯π inter-actions, forming layers parallel to the bc plane. The layers are linked via weak C-H⋯O hydrogen bonds and slipped parallel π-π inter-actions [inter-centroid distance = 3.6729 (10) Å], forming a three-dimensional structure. The thio-phene ring has an approximate 180° rotational disorder about the bridging C-C bond.

Social Features of Online Networks: The Strength of Intermediary Ties in Online Social Media

PubMed Central

Grabowicz, Przemyslaw A.; Ramasco, José J.; Moro, Esteban; Pujol, Josep M.; Eguiluz, Victor M.

2012-01-01

An increasing fraction of today's social interactions occur using online social media as communication channels. Recent worldwide events, such as social movements in Spain or revolts in the Middle East, highlight their capacity to boost people's coordination. Online networks display in general a rich internal structure where users can choose among different types and intensity of interactions. Despite this, there are still open questions regarding the social value of online interactions. For example, the existence of users with millions of online friends sheds doubts on the relevance of these relations. In this work, we focus on Twitter, one of the most popular online social networks, and find that the network formed by the basic type of connections is organized in groups. The activity of the users conforms to the landscape determined by such groups. Furthermore, Twitter's distinction between different types of interactions allows us to establish a parallelism between online and offline social networks: personal interactions are more likely to occur on internal links to the groups (the weakness of strong ties); events transmitting new information go preferentially through links connecting different groups (the strength of weak ties) or even more through links connecting to users belonging to several groups that act as brokers (the strength of intermediary ties). PMID:22247773

Disentangling effects of abiotic factors and biotic interactions on cross-taxon congruence in species turnover patterns of plants, moths and beetles

PubMed Central

Duan, Meichun; Liu, Yunhui; Yu, Zhenrong; Baudry, Jacques; Li, Liangtao; Wang, Changliu; Axmacher, Jan C.

2016-01-01

High cross-taxon congruence in species diversity patterns is essential for the use of surrogate taxa in biodiversity conservation, but presence and strength of congruence in species turnover patterns, and the relative contributions of abiotic environmental factors and biotic interaction towards this congruence, remain poorly understood. In our study, we used variation partitioning in multiple regressions to quantify cross-taxon congruence in community dissimilarities of vascular plants, geometrid and arciinid moths and carabid beetles, subsequently investigating their respective underpinning by abiotic factors and biotic interactions. Significant cross-taxon congruence observed across all taxon pairs was linked to their similar responses towards elevation change. Changes in the vegetation composition were closely linked to carabid turnover, with vegetation structure and associated microclimatic conditions proposed causes of this link. In contrast, moth assemblages appeared to be dominated by generalist species whose turnover was weakly associated with vegetation changes. Overall, abiotic factors exerted a stronger influence on cross-taxon congruence across our study sites than biotic interactions. The weak congruence in turnover observed particularly between plants and moths highlights the importance of multi-taxon approaches based on groupings of taxa with similar turnovers, rather than the use of single surrogate taxa or environmental proxies, in biodiversity assessments. PMID:27032533

Understanding and Altering the Longitudinal Course of Marriage

ERIC Educational Resources Information Center

Bradbury, Thomas N.; Karney, Benjamin R.

2004-01-01

Weak and counterintuitive findings linking couples' interactional processes to marital outcomes have prompted new lines of research on how marriages change. Recent findings reviewed here highlight the value of (a) expanding conceptions of marital interaction by considering how social support and positive affect moderate the effects of…

A Developmental Investigation of Processing Costs in Implicature Production

ERIC Educational Resources Information Center

Pouscoulous, Nausicaa; Noveck, Ira A.; Politzer, Guy; Bastide, Anne

2007-01-01

Much developmental work has been devoted to "scalar implicatures." These are implicitly communicated propositions linked to relatively weak terms (consider how "Some" pragmatically implies "Not all") that are more likely to be carried out by adults than by children. Children tend to retain the linguistically encoded…

Ten Years of Entrepreneurship Education at Chinese Universities: Evolution, Problems, and System Building

ERIC Educational Resources Information Center

Weiming, Li; Chunyan, Li; Xiaohua, Du

2016-01-01

Entrepreneurship education has experienced four stages of development in Chinese universities, shifting from entrepreneurship show to entrepreneurship education, from teacher training to student education, from classroom teaching to multimodal teaching, and from imparting knowledge to cultivating skills. Currently, the weak links in…

Fatal hepatic hemorrhage by peliosis hepatis in X-linked myotubular myopathy: a case report.

PubMed

Motoki, T; Fukuda, M; Nakano, T; Matsukage, S; Fukui, A; Akiyoshi, S; Hayashi, Y K; Ishii, E; Nishino, I

2013-11-01

We report a 5-year-old boy with X-linked myotubular myopathy complicated by peliosis hepatis. At birth, he was affected with marked generalized muscle hypotonia and weakness, which required permanent ventilatory support, and was bedridden for life. He died of acute fatal hepatic hemorrhage after using a mechanical in-exsufflator. Peliosis hepatis, defined as multiple, variable-sized, cystic blood-filled spaces through the liver parenchyma, was confirmed by autopsy. To avoid fatal hepatic hemorrhage by peliosis hepatis, routine hepatic function tests and abdominal imaging tests should be performed for patients with X-linked myotubular myopathy, especially at the time of using artificial respiration. Copyright © 2013 Elsevier B.V. All rights reserved.

The CCSDS Next Generation Space Data Link Protocol (NGSLP)

NASA Technical Reports Server (NTRS)

Kazz, Greg J.; Greenberg, Edward

2014-01-01

The CCSDS space link protocols i.e., Telemetry (TM), Telecommand (TC), Advanced Orbiting Systems (AOS) were developed in the early growth period of the space program. They were designed to meet the needs of the early missions, be compatible with the available technology and focused on the specific link environments. Digital technology was in its infancy and spacecraft power and mass issues enforced severe constraints on flight implementations. Therefore the Telecommand protocol was designed around a simple Bose, Hocquenghem, Chaudhuri (BCH) code that provided little coding gain and limited error detection but was relatively simple to decode on board. The infusion of the concatenated Convolutional and Reed-Solomon codes5 for telemetry was a major milestone and transformed telemetry applications by providing them the ability to more efficiently utilize the telemetry link and its ability to deliver user data. The ability to significantly lower the error rates on the telemetry links enabled the use of packet telemetry and data compression. The infusion of the high performance codes for telemetry was enabled by the advent of digital processing, but it was limited to earth based systems supporting telemetry. The latest CCSDS space link protocol, Proximity-1 was developed in early 2000 to meet the needs of short-range, bi-directional, fixed or mobile radio links characterized by short time delays, moderate but not weak signals, and short independent sessions. Proximity-1 has been successfully deployed on both NASA and ESA missions at Mars and is planned to be utilized by all Mars missions in development. A new age has arisen, one that now provides the means to perform advanced digital processing in spacecraft systems enabling the use of improved transponders, digital correlators, and high performance forward error correcting codes for all communications links. Flight transponders utilizing digital technology have emerged and can efficiently provide the means to make the next leap in performance for space link communications. Field Programmable Gate Arrays (FPGAs) provide the capability to incorporate high performance forward error correcting codes implemented within software transponders providing improved performance in data transfer, ranging, link security, and time correlation. Given these synergistic technological breakthroughs, the time has come to take advantage of them in applying them to both on going (e.g., command, telemetry) and emerging (e.g., space link security, optical communication) space link applications. However one of the constraining factors within the Data Link Layer in realizing these performance gains is the lack of a generic transfer frame format and common supporting services amongst the existing CCSDS link layer protocols. Currently each of the four CCSDS link layer protocols (TM, TC, AOS, and Proximity-1) have unique formats and services which prohibits their reuse across the totality of all space link applications of CCSDS member space agencies. For example, Mars missions. These missions implement their proximity data link layer using the Proximity-1 frame format and the services it supports but is still required to support the direct from Earth (TC) protocols and the Direct To Earth (AOS/TM) protocols. The prime purpose of this paper, is to describe a new general purpose CCSDS Data Link layer protocol, the NGSLP that will provide the required services along with a common transfer frame format for all the CCSDS space links (ground to/from space and space to space links) targeted for emerging missions after a CCSDS agency-wide coordinated date. This paper will also describe related options that can be included for the Coding and Synchronization sub-layer of the Data Link layer to extend the capacities of the link and additionally provide an independence of the transfer frame sub-layer from the coding sublayer. This feature will provide missions the option of running either the currently performed synchronous coding and transfer frame data link or an asynchronous coding/frame data link, in which the transfer frame length is independent of the block size of the code. The benefits from the elimination of this constraint (frame synchronized to the code block) will simplify the interface between the transponder and the data handling equipment and reduce implementation costs and complexities. The benefits include: inclusion of encoders/decoders into transmitters and receivers without regard to data link protocols, providing the ability to insert latency sensitive messages into the link to support launch, landing/docking, telerobotics. and Variable Coded Modulation (VCM). In addition the ability to transfer different sized frames can provide a backup for delivering stored anomaly engineering data simultaneously with real time data, or relaying of frames from various sources onto a trunk line for delivery to Earth.

Parameterized post-Newtonian cosmology

NASA Astrophysics Data System (ADS)

Sanghai, Viraj A. A.; Clifton, Timothy

2017-03-01

Einstein’s theory of gravity has been extensively tested on solar system scales, and for isolated astrophysical systems, using the perturbative framework known as the parameterized post-Newtonian (PPN) formalism. This framework is designed for use in the weak-field and slow-motion limit of gravity, and can be used to constrain a large class of metric theories of gravity with data collected from the aforementioned systems. Given the potential of future surveys to probe cosmological scales to high precision, it is a topic of much contemporary interest to construct a similar framework to link Einstein’s theory of gravity and its alternatives to observations on cosmological scales. Our approach to this problem is to adapt and extend the existing PPN formalism for use in cosmology. We derive a set of equations that use the same parameters to consistently model both weak fields and cosmology. This allows us to parameterize a large class of modified theories of gravity and dark energy models on cosmological scales, using just four functions of time. These four functions can be directly linked to the background expansion of the universe, first-order cosmological perturbations, and the weak-field limit of the theory. They also reduce to the standard PPN parameters on solar system scales. We illustrate how dark energy models and scalar-tensor and vector-tensor theories of gravity fit into this framework, which we refer to as ‘parameterized post-Newtonian cosmology’ (PPNC).

Using Bayes to get the most out of non-significant results

PubMed Central

Dienes, Zoltan

2014-01-01

No scientific conclusion follows automatically from a statistically non-significant result, yet people routinely use non-significant results to guide conclusions about the status of theories (or the effectiveness of practices). To know whether a non-significant result counts against a theory, or if it just indicates data insensitivity, researchers must use one of: power, intervals (such as confidence or credibility intervals), or else an indicator of the relative evidence for one theory over another, such as a Bayes factor. I argue Bayes factors allow theory to be linked to data in a way that overcomes the weaknesses of the other approaches. Specifically, Bayes factors use the data themselves to determine their sensitivity in distinguishing theories (unlike power), and they make use of those aspects of a theory’s predictions that are often easiest to specify (unlike power and intervals, which require specifying the minimal interesting value in order to address theory). Bayes factors provide a coherent approach to determining whether non-significant results support a null hypothesis over a theory, or whether the data are just insensitive. They allow accepting and rejecting the null hypothesis to be put on an equal footing. Concrete examples are provided to indicate the range of application of a simple online Bayes calculator, which reveal both the strengths and weaknesses of Bayes factors. PMID:25120503

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

Allen, J; Velsko, S

This report explores the question of whether meaningful conclusions can be drawn regarding the transmission relationship between two microbial samples on the basis of differences observed between the two sample's respective genomes. Unlike similar forensic applications using human DNA, the rapid rate of microbial genome evolution combined with the dynamics of infectious disease require a shift in thinking on what it means for two samples to 'match' in support of a forensic hypothesis. Previous outbreaks for SARS-CoV, FMDV and HIV were examined to investigate the question of how microbial sequence data can be used to draw inferences that link twomore » infected individuals by direct transmission. The results are counter intuitive with respect to human DNA forensic applications in that some genetic change rather than exact matching improve confidence in inferring direct transmission links, however, too much genetic change poses challenges, which can weaken confidence in inferred links. High rates of infection coupled with relatively weak selective pressure observed in the SARS-CoV and FMDV data lead to fairly low confidence for direct transmission links. Confidence values for forensic hypotheses increased when testing for the possibility that samples are separated by at most a few intermediate hosts. Moreover, the observed outbreak conditions support the potential to provide high confidence values for hypothesis that exclude direct transmission links. Transmission inferences are based on the total number of observed or inferred genetic changes separating two sequences rather than uniquely weighing the importance of any one genetic mismatch. Thus, inferences are surprisingly robust in the presence of sequencing errors provided the error rates are randomly distributed across all samples in the reference outbreak database and the novel sequence samples in question. When the number of observed nucleotide mutations are limited due to characteristics of the outbreak or the availability of only partial rather than whole genome sequencing, indel information was shown to have the potential to improve performance but only for select outbreak conditions. In examined HIV transmission cases, extended evolution proved to be the limiting factor in assigning high confidence to transmission links, however, the potential to correct for extended evolution not associated with transmission events is demonstrated. Outbreak specific conditions such as selective pressure (in the form of varying mutation rate), are shown to impact the strength of inference made and a Monte Carlo simulation tool is introduced, which is used to provide upper and lower bounds on the confidence values associated with a forensic hypothesis.« less

The Formation, Transport Properties and Microstructure of 45 Degrees (001) Tilt Grain Boundaries in Yttrium BARIUM(2) COPPER(3) OXYGEN(7-X) Thin Films

NASA Astrophysics Data System (ADS)

Vuchic, Boris Vukan

1995-01-01

Most high angle grain boundaries in high-T _{c} superconductors exhibit weak link behavior. The Josephson-like properties of these grain boundaries can be used for many device applications such as superconducting quantum interference devices (SQUIDs). The structure-property relationship of different types of 45 ^circ (001) YBa_2 Cu_3O_{7-x} thin film grain boundary junctions are examined to study their weak link nature. A technique, termed sputter-induced epitaxy, is developed to form 45^circ (001) tilt grain boundaries in YBa_2Cu _3O_{7-x} thin films on (100) MgO substrates. A low voltage ion bombardment pre-growth substrate treatment is used to modify the epitaxial orientation relationship between the thin film and the substrate in selected regions. By modifying the orientation of the thin film, grain boundary junctions can be placed in any configuration on the substrate. A variety of pre-growth sputtering conditions in conjunction with atomic force microscopy and Rutherford backscatter spectrometry are used to determine the role of the ions in modifying the substrate surface. Sputter-induced epitaxy is extended to a multilayer MgO/LaAlO_3 substrate, allowing integration of the sputter -induced epitaxy junctions into multilayer structures. The low temperature transport properties of the sputter-induced epitaxy junctions and a set of bi-epitaxial grain boundaries are studied. Individual grain boundaries are isolated and characterized for resistance vs. temperature, current vs. voltage as a function of temperature and magnetic field behavior. Resistive and superconducting grain boundaries are compared. Microstructural analysis is performed using scanning electron microscopy, transmission electron microscopy and high resolution electron microscopy (HREM). Marked differences are observed in the microstructure of resistive and superconducting grain boundaries. HREM studies suggest the importance of the local atomic scale structure of the grain boundary in transport properties. A phenomenological grain boundary model is proposed to describe the structure -property relationship of the boundaries.

Stabilization of unpaved shoulders on moderate and weak subgrade using geosynthetics : [technical summary].

DOT National Transportation Integrated Search

2016-01-01

Geosynthetics have been used to improve the performance of roadways, especially when : weak subgrade soil exists. In this study, two types of geosynthetic products, geocell and : geogrid, were investigated for their application for stabilization of u...

A knowledge-based system with learning for computer communication network design

NASA Technical Reports Server (NTRS)

Pierre, Samuel; Hoang, Hai Hoc; Tropper-Hausen, Evelyne

1990-01-01

Computer communication network design is well-known as complex and hard. For that reason, the most effective methods used to solve it are heuristic. Weaknesses of these techniques are listed and a new approach based on artificial intelligence for solving this problem is presented. This approach is particularly recommended for large packet switched communication networks, in the sense that it permits a high degree of reliability and offers a very flexible environment dealing with many relevant design parameters such as link cost, link capacity, and message delay.

Evidence for linkage disequilibrium in chromosome 13-linked Duchenne-like muscular dystrophy

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

Othmane, K.B.; Speer, M.C.; Stauffer, J.

1995-09-01

Duchenne-like muscular dystrophy (DLMD) is an autosomal recessive Limb Girdle muscular dystrophy (LGMD2C) characterized by late age of onset, proximal muscle weakness leading to disability, high creatine kinase values, normal intelligence and normal dystrophin in muscle biopsy. We have shown previously that three DLMD families from Tunisia are linked to chromosome 13q12. To further localize the LGMD2C gene, we have investigated seven additional families (119 individuals). Both genotyping and two-point linkage analysis were performed as described elsewhere. 7 refs., 1 fig., 1 tab.

Suicidality and interrogative suggestibility.

PubMed

Pritchard-Boone, Lea; Range, Lillian M

2005-01-01

All people are subject to memory suggestibility, but suicidal individuals may be especially so. The link between suicidality and suggestibility is unclear given mixed findings and methodological weaknesses of past research. To test the link between suicidality and interrogative suggestibility, 149 undergraduates answered questions about suicidal thoughts and reasons for living, and participated in a direct suggestibility procedure. As expected, suggestibility correlated with suicidality but accounted for little overall variance (4%). Mental health professionals might be able to take advantage of client suggestibility by directly telling suicidal persons to refrain from suicidal thoughts or actions.

Demographic matrix model for informing swallow-wort (Vincetoxicum spp.) biological control

USDA-ARS?s Scientific Manuscript database

Demographic matrix modeling of plant populations can be a powerful tool to identify key life stage transitions that contribute the most to population growth of an invasive plant and hence should be targeted for disruption (weak links) by biological control and/or other control tactics. Therefore, t...

Controllable nonlinearity in a dual-coupling optomechanical system under a weak-coupling regime

NASA Astrophysics Data System (ADS)

Zhu, Gui-Lei; Lü, Xin-You; Wan, Liang-Liang; Yin, Tai-Shuang; Bin, Qian; Wu, Ying

2018-03-01

Strong quantum nonlinearity gives rise to many interesting quantum effects and has wide applications in quantum physics. Here we investigate the quantum nonlinear effect of an optomechanical system (OMS) consisting of both linear and quadratic coupling. Interestingly, a controllable optomechanical nonlinearity is obtained by applying a driving laser into the cavity. This controllable optomechanical nonlinearity can be enhanced into a strong coupling regime, even if the system is initially in the weak-coupling regime. Moreover, the system dissipation can be suppressed effectively, which allows the appearance of phonon sideband and photon blockade effects in the weak-coupling regime. This work may inspire the exploration of a dual-coupling optomechanical system as well as its applications in modern quantum science.

The advancement of chemical cross-linking and mass spectrometry for structural proteomics: from single proteins to protein interaction networks.

PubMed

Sinz, Andrea

2014-12-01

During the last 15 years, chemical cross-linking combined with mass spectrometry (MS) and computational modeling has advanced from investigating 3D-structures of isolated proteins to deciphering protein interaction networks. In this article, the author discusses the advent, the development and the current status of the chemical cross-linking/MS strategy in the context of recent technological developments. A direct way to probe in vivo protein-protein interactions is by site-specific incorporation of genetically encoded photo-reactive amino acids or by non-directed incorporation of photo-reactive amino acids. As the chemical cross-linking/MS approach allows the capture of transient and weak interactions, it has the potential to become a routine technique for unraveling protein interaction networks in their natural cellular environment.

Rehabilitation in practice: management of lower motor neuron weakness.

PubMed

Ramdharry, Gita M

2010-05-01

This series of articles for rehabilitation in practice aims to cover a knowledge element of the rehabilitation medicine curriculum. Nevertheless they are intended to be of interest to a multidisciplinary audience. The competency addressed in this article is 'The trainee consistently demonstrates a knowledge of the pathophysiology of various specific impairments including lower motor neuron weakness' and 'management approaches for specific impairments including lower motor neuron weakness'.This article explores weakness as a lower motor symptom. Weakness as a primary impairment of neuromuscular diseases is addressed, with recognition of the phenomenon of disuse atrophy, and how weakness impacts on the functional abilities of people with myopathy and neuropathy. Interventions to reduce weakness or address the functional consequences of weakness are evaluated with consideration of safety and clinical application. This paper will allow readers to: (1) appraise the contribution of research in rehabilitation of lower motor neuron weakness to clinical decision making and (2) engage with the issues that arise when researching rehabilitation interventions for lower motor neuron weakness. Impairments associated with neuromuscular conditions can lead to significant functional difficulties that can impact on a person's daily participation. This article focuses on the primary impairment of weakness and explores the research evidence for rehabilitation interventions that directly influence weakness or address the impact of weakness on function.

360 Degrees feedback for emergency physicians in Singapore.

PubMed

Tham, Kum-Ying

2007-08-01

To determine if emergency physicians (EPs) are ready to accept 360 degrees feedback, and agreement between self and colleagues' assessment in a 360 degrees feedback for EPs. Self-administered questionnaire to determine acceptability of 360 degrees feedback (n = 43). Each EP completed the Physician Achievement Review self-assessment and approached five colleagues to complete an assessment for him/her. Thirty-one responded: 77.4% preferred to select their appraisers, 90.3% wanted feedback to be confidential, 58.1% would share feedback with supervisors, but only 35.5% would link feedback to remuneration. Colleagues rated EPs' holistic management, humanistic aspects and patient communication, and professional relationship with colleagues as weak domains, weaknesses which EPs were only partially aware. EPs would accept 360 degrees feedback provided that they selected their appraisers and results were confidential. Colleagues reported that EPs were weak in "soft" and system skills.

360° feedback for emergency physicians in Singapore

PubMed Central

Tham, Kum‐Ying

2007-01-01

Objectives To determine if emergency physicians (EPs) are ready to accept 360° feedback, and agreement between self and colleagues' assessment in a 360° feedback for EPs. Methods Self‐administered questionnaire to determine acceptability of 360° feedback (n = 43). Each EP completed the Physician Achievement Review self‐assessment and approached five colleagues to complete an assessment for him/her. Results Thirty‐one responded: 77.4% preferred to select their appraisers, 90.3% wanted feedback to be confidential, 58.1% would share feedback with supervisors, but only 35.5% would link feedback to remuneration. Colleagues rated EPs' holistic management, humanistic aspects and patient communication, and professional relationship with colleagues as weak domains, weaknesses which EPs were only partially aware. Conclusions EPs would accept 360° feedback provided that they selected their appraisers and results were confidential. Colleagues reported that EPs were weak in “soft” and system skills. PMID:17652683

Gossip and Distributed Kalman Filtering: Weak Consensus Under Weak Detectability

NASA Astrophysics Data System (ADS)

Kar, Soummya; Moura, José M. F.

2011-04-01

The paper presents the gossip interactive Kalman filter (GIKF) for distributed Kalman filtering for networked systems and sensor networks, where inter-sensor communication and observations occur at the same time-scale. The communication among sensors is random; each sensor occasionally exchanges its filtering state information with a neighbor depending on the availability of the appropriate network link. We show that under a weak distributed detectability condition: 1. the GIKF error process remains stochastically bounded, irrespective of the instability properties of the random process dynamics; and 2. the network achieves \\emph{weak consensus}, i.e., the conditional estimation error covariance at a (uniformly) randomly selected sensor converges in distribution to a unique invariant measure on the space of positive semi-definite matrices (independent of the initial state.) To prove these results, we interpret the filtered states (estimates and error covariances) at each node in the GIKF as stochastic particles with local interactions. We analyze the asymptotic properties of the error process by studying as a random dynamical system the associated switched (random) Riccati equation, the switching being dictated by a non-stationary Markov chain on the network graph.

Application of theory-based evaluation for the critical analysis of national biofuel policy: A case study in Malaysia.

PubMed

Abdul-Manan, Amir F N; Baharuddin, Azizan; Chang, Lee Wei

2015-10-01

Theory-based evaluation (TBE) is an effectiveness assessment technique that critically analyses the theory underlying an intervention. Whilst its use has been widely reported in the area of social programmes, it is less applied in the field of energy and climate change policy evaluations. This paper reports a recent study that has evaluated the effectiveness of the national biofuel policy (NBP) for the transport sector in Malaysia by adapting a TBE approach. Three evaluation criteria were derived from the official goals of the NBP, those are (i) improve sustainability and environmental friendliness, (ii) reduce fossil fuel dependency, and (iii) enhance stakeholders' welfare. The policy theory underlying the NBP has been reconstructed through critical examination of the policy and regulatory documents followed by a rigorous appraisal of the causal link within the policy theory through the application of scientific knowledge. This study has identified several weaknesses in the policy framework that may engender the policy to be ineffective. Experiences with the use of a TBE approach for policy evaluations are also shared in this report. Copyright © 2015 Elsevier Ltd. All rights reserved.

Calibration of ultra-low infrared power at NIST

NASA Astrophysics Data System (ADS)

Woods, Solomon I.; Carr, Stephen M.; Carter, Adriaan C.; Jung, Timothy M.; Datla, Raju U.

2010-07-01

The Low Background Infrared (LBIR) facility has developed and tested the components of a new detector for calibration of infrared greater than 1 pW, with 0.1 % uncertainty. Calibration of such low powers could be valuable for the quantitative study of weak astronomical sources in the infrared. The pW-ACR is an absolute cryogenic radiometer (ACR) employing a high resolution transition edge sensor (TES) thermometer, ultra-weak thermal link and miniaturized receiver to achieve a noise level of around 1 fW at a temperature of 2 K. The novel thermometer employs the superconducting transition of a tin (Sn) core and has demonstrated a temperature noise floor less than 3 nK/Hz1/2. Using an applied magnetic field from an integrated solenoid to suppress the Sn transition temperature, the operating temperature of the thermometer can be tuned to any temperature below 3.6 K. The conical receiver is coated on the inside with infrared-absorbing paint and has a demonstrated absorptivity of 99.94 % at 10.6 μm. The thermal link is made from a thin-walled polyimide tube and has exhibited very low thermal conductance near 2x10-7 W/K. In tests with a heater mounted on the receiver, the receiver/thermal-link assembly demonstrated a thermal time constant of about 15 s. Based on these experimental results, it is estimated that an ACR containing these components can achieve noise levels below 1 fW, and the design of a radiometer merging the new thermometer, receiver and thermal link will be discussed.

Simulating the thermodynamics of charging in weak polyelectrolytes: the Debye-Hückel limit

NASA Astrophysics Data System (ADS)

Rathee, Vikramjit S.; Sikora, Benjamin J.; Sidky, Hythem; Whitmer, Jonathan K.

2018-01-01

The coil-globule transition in weak (annealed) polyelectrolytes involves a subtle balance of pH, charge strength, and solvation forces. In this work, we utilize a coarse-grained hybrid grand-canonical Monte Carlo and molecular dynamics approach to explore the swelling behavior of weak linear and star polyelectrolytes under different ionic screening conditions and pH. Importantly, we are able to quantify topology-dependent effects in charging which arise at the core of star polymers. Our results are suggestive of suppression of charging in star weak polyelectrolytes in comparison to linear weak polyelectrolytes. Furthermore, we characterize the coil-globule transition in linear and star weak polyelectrolyte through expanded ensemble density-of-states simulations which suggest a change from a first order to second order phase transition moving from linear to star polyelectrolytes. Lastly, we characterize the inhomogeneous charging across the weak star polyelectrolyte through observed shifts in {{Δ }}{{{pK}}}{{o}}, and compare with experimental work. We discuss these results in relation to surfaces functionalized by weak polyelectrolyte brushes and weak polyelectrolyte-based drug delivery applications.

Distinctive Features of Surface Winds over Indian Ocean Between Strong and Weak Indian Summer Monsoons: Implications With Respect To Regional Rainfall Change in India

NASA Astrophysics Data System (ADS)

Zheng, Y.; Bourassa, M. A.; Ali, M. M.

2017-12-01

This observational study focuses on characterizing the surface winds in the Arabian Sea (AS), the Bay of Bengal (BoB), and the southern Indian Ocean (SIO) with special reference to the strong and weak Indian summer monsoon rainfall (ISMR) using the latest daily gridded rainfall dataset provided by the Indian Meteorological Department (IMD) and the Cross-Calibrated Multi-Platform (CCMP) gridded wind product version 2.0 produced by Remote Sensing System (RSS) over the overlapped period 1991-2014. The potential links between surface winds and Indian regional rainfall are also examined. Results indicate that the surface wind speeds in AS and BoB during June-August are almost similar during strong ISMRs and weak ISMRs, whereas significant discrepancies are observed during September. By contrast, the surface wind speeds in SIO during June-August are found to be significantly different between strong and weak ISMRs, where they are similar during September. The significant differences in monthly mean surface wind convergence between strong and weak ISMRs are not coherent in space in the three regions. However, the probability density function (PDF) distributions of daily mean area-averaged values are distinctive between strong and weak ISMRs in the three regions. The correlation analysis indicates the area-averaged surface wind speeds in AS and the area-averaged wind convergence in BoB are highly correlated with regional rainfall for both strong and weak ISMRs. The wind convergence in BoB during strong ISMRs is relatively better correlated with regional rainfall than during weak ISMRs. The surface winds in SIO do not greatly affect Indian rainfall in short timescales, however, they will ultimately affect the strength of monsoon circulation by modulating Indian Ocean Dipole (IOD) mode via atmosphere-ocean interactions.

Neurogenic Orofacial Weakness and Speech in Adults With Dysarthria

PubMed Central

Makashay, Matthew J.; Helou, Leah B.; Clark, Heather M.

2017-01-01

Purpose This study compared orofacial strength between adults with dysarthria and neurologically normal (NN) matched controls. In addition, orofacial muscle weakness was examined for potential relationships to speech impairments in adults with dysarthria. Method Matched groups of 55 adults with dysarthria and 55 NN adults generated maximum pressure (Pmax) against an air-filled bulb during lingual elevation, protrusion and lateralization, and buccodental and labial compressions. These orofacial strength measures were compared with speech intelligibility, perceptual ratings of speech, articulation rate, and fast syllable-repetition rate. Results The dysarthria group demonstrated significantly lower orofacial strength than the NN group on all tasks. Lingual strength correlated moderately and buccal strength correlated weakly with most ratings of speech deficits. Speech intelligibility was not sensitive to dysarthria severity. Individuals with severely reduced anterior lingual elevation Pmax (< 18 kPa) had normal to profoundly impaired sentence intelligibility (99%–6%) and moderately to severely impaired speech (26%–94% articulatory imprecision; 33%–94% overall severity). Conclusions Results support the presence of orofacial muscle weakness in adults with dysarthrias of varying etiologies but reinforce tenuous links between orofacial strength and speech production disorders. By examining individual data, preliminary evidence emerges to suggest that speech, but not necessarily intelligibility, is likely to be impaired when lingual weakness is severe. PMID:28763804

Constraint Network Analysis (CNA): a Python software package for efficiently linking biomacromolecular structure, flexibility, (thermo-)stability, and function.

PubMed

Pfleger, Christopher; Rathi, Prakash Chandra; Klein, Doris L; Radestock, Sebastian; Gohlke, Holger

2013-04-22

For deriving maximal advantage from information on biomacromolecular flexibility and rigidity, results from rigidity analyses must be linked to biologically relevant characteristics of a structure. Here, we describe the Python-based software package Constraint Network Analysis (CNA) developed for this task. CNA functions as a front- and backend to the graph-based rigidity analysis software FIRST. CNA goes beyond the mere identification of flexible and rigid regions in a biomacromolecule in that it (I) provides a refined modeling of thermal unfolding simulations that also considers the temperature-dependence of hydrophobic tethers, (II) allows performing rigidity analyses on ensembles of network topologies, either generated from structural ensembles or by using the concept of fuzzy noncovalent constraints, and (III) computes a set of global and local indices for quantifying biomacromolecular stability. This leads to more robust results from rigidity analyses and extends the application domain of rigidity analyses in that phase transition points ("melting points") and unfolding nuclei ("structural weak spots") are determined automatically. Furthermore, CNA robustly handles small-molecule ligands in general. Such advancements are important for applying rigidity analysis to data-driven protein engineering and for estimating the influence of ligand molecules on biomacromolecular stability. CNA maintains the efficiency of FIRST such that the analysis of a single protein structure takes a few seconds for systems of several hundred residues on a single core. These features make CNA an interesting tool for linking biomacromolecular structure, flexibility, (thermo-)stability, and function. CNA is available from http://cpclab.uni-duesseldorf.de/software for nonprofit organizations.

Scanning SQUID Microscope and its Application in Detecting Weak Currents

NASA Astrophysics Data System (ADS)

Zhong, Chaorong; Li, Fei; Zhang, Fenghui; Ding, Hongsheng; Luo, Sheng; Lin, Dehua; He, Yusheng

A scanning SQUID microscope based on HTS dc SQUID has been developed. One of the applications of this microscope is to detect weak currents inside the sample. Considering that what being detected by the SQUID is the vertical component of the magnetic field on a plan where the SQUID lies, whereas the current which produces the magnetic field is actually located in a plan below the SQUID, a TWO PLAN model has been established. In this model Biot-Savart force laws and Fourier transformation were used to inverse the detected magnetic field into the underneath weak current. It has been shown that the distance between the current and the SQUID and the noise ratio of the experimental data have significant effects on the quality of the inverse process.

Getting Better All the Time

ERIC Educational Resources Information Center

Watkins, Arwyn

2010-01-01

What a journey it has been for all involved in the delivery of work-based learning in Wales. Over the past four years the two key strands of the Assembly Government's contracted work-based learning delivery--namely the Skill Build and apprenticeship programmes--have been transformed. Once regarded as the weak link in the sector, the quality of…

Moral Motivation, Moral Judgment, and Antisocial Behavior

ERIC Educational Resources Information Center

Brooks, Jeff; Bock, Tonia; Narvaez, Darcia

2013-01-01

The link between judgment and action is weak throughout psychology, including moral psychology. That is, people often do not act in accordance with their reasoning. Might moral judgment development be better viewed as a capacity that inhibits "immoral" behavior? One model that helps account for the moral judgment-action gap is Rest's…

Clitics and Head-Movement as Intra-Syntactic Morphology

ERIC Educational Resources Information Center

DiGirolamo, Cara Masten

2017-01-01

This dissertation approaches the idea of lexical types such as word, clitic and affix from an oblique angle. Starting with Cardinaletti & Starke's (1999) diagnostics for the Weak Pronoun, I deconstruct the category of clitic, breaking it down into two binary qualities: the syntactic primitive of being linked to a head of a different basic…

Measurement Techniques for Transmit Source Clock Jitter for Weak Serial RF Links

NASA Technical Reports Server (NTRS)

Lansdowne, Chatwin A.; Schlesinger, Adam M.

2010-01-01

Techniques for filtering clock jitter measurements are developed, in the context of controlling data modulation jitter on an RF carrier to accommodate low signal-to-noise ratio thresholds of high-performance error correction codes. Measurement artifacts from sampling are considered, and a tutorial on interpretation of direct readings is included.

Response to Patrick Love's "Informal Theory": A Rejoinder

ERIC Educational Resources Information Center

Evans, Nancy J.; Guido, Florence M.

2012-01-01

This rejoinder to Patrick Love's article, "Informal Theory: The Ignored Link in Theory-to-Practice," which appears earlier in this issue of the "Journal of College Student Development", was written at the invitation of the Editor. In the critique, we point out the weaknesses of many of Love's arguments and propositions. We provide an alternative…

Pro-Poor PRIMR: Improving Early Literacy Skills for Children from Low-Income Families in Kenya

ERIC Educational Resources Information Center

Piper, Benjamin; Jepkemei, Evelyn; Kibukho, Kennedy

2015-01-01

Children from low-income families are at risk of learning outcome difficulties, particularly in literacy. Various studies link poor literacy results with performance later in primary and secondary school, and suggest that poverty, literacy skills and weak instructional methods combine to drastically limit the educational opportunities for many…

Vocational Education Qualifications' Roles in Pathways to Work in Liberal Market Economies

ERIC Educational Resources Information Center

Wheelahan, Leesa; Moodie, Gavin

2017-01-01

The links between vocational qualifications and occupational destinations are weak in many Anglophone countries, even though the explicit purpose of vocational qualifications is to prepare individuals for occupations. Using Australia and Canada as case studies, this is explained at three levels of analysis: at the national level by systems of…

How to Improve the Relationship between Theory and Practice in Teacher Education

ERIC Educational Resources Information Center

Rasmussen, Jens; Rash-Christensen, Andreas

2015-01-01

The Expert in Teaching study pays special attention to the objective of connecting coursework more directly to practice in pre-service teacher education. The study was focused on developing better solutions to the problematic, weak, or even sometimes totally missing, link between theory (teaching at college) and practice (teaching internship) in…

Critical current of SF-NFS Josephson junctions

NASA Astrophysics Data System (ADS)

Soloviev, I. I.; Klenov, N. V.; Bakursky, S. V.; Kupriyanov, M. Yu.; Golubov, A. A.

2015-02-01

The properties of SF-NFS sandwiches composed of two superconducting (S) electrodes separated by a weak-link region formed by a normal-metal (N) step with the thickness d N situated on the top of a lower S electrode and a ferromagnetic (F) layer with the thickness d F deposited onto the step and the remaining free surface of the lower electrode have been studied theoretically. It has been shown in the approximation of linearized semiclassical Usadel equations that the two-dimensional problem in the weak-link region can be reduced to two one-dimensional problems in its SFS and SNFS segments. The spatial distributions of the critical current density J c in the segments as a function of the layer thickness d F have been calculated. The dependences of the critical current I c of the structure on the magnitude of the magnetization vector M of the ferromagnetic layer have been found for various directions of the magnetization within the junction plane. It has been shown that these dependences are affected considerably by both the orientation of M and the spatial distribution of J c.

Probability density of aperture-averaged irradiance fluctuations for long range free space optical communication links.

PubMed

Lyke, Stephen D; Voelz, David G; Roggemann, Michael C

2009-11-20

The probability density function (PDF) of aperture-averaged irradiance fluctuations is calculated from wave-optics simulations of a laser after propagating through atmospheric turbulence to investigate the evolution of the distribution as the aperture diameter is increased. The simulation data distribution is compared to theoretical gamma-gamma and lognormal PDF models under a variety of scintillation regimes from weak to strong. Results show that under weak scintillation conditions both the gamma-gamma and lognormal PDF models provide a good fit to the simulation data for all aperture sizes studied. Our results indicate that in moderate scintillation the gamma-gamma PDF provides a better fit to the simulation data than the lognormal PDF for all aperture sizes studied. In the strong scintillation regime, the simulation data distribution is gamma gamma for aperture sizes much smaller than the coherence radius rho0 and lognormal for aperture sizes on the order of rho0 and larger. Examples of how these results affect the bit-error rate of an on-off keyed free space optical communication link are presented.

Implications of Weak-Link Behavior on the Performance of Mo/Au Bilayer Transition-Edge Sensors

NASA Technical Reports Server (NTRS)

Smith, Stephen J.

2011-01-01

Understanding the physical properties of the superconducting-to-normal transition is fundamental for optimizing the design and performance of transition-edge sensors (TESs). Recent critical current measurements of Mol Au bilayer test structures show that they act as weak superconducting links, exhibiting oscillatory, Fraunhofer-like behavior with applied magnetic field. In this paper we investigate the implications of this behavior for TES X-ray detectors, under operational bias conditions. These devices include normal metal features used for absorber attachment and unexplained noise suppression, which result in modifications to the previously reported critical current behavior. We present measurements of the logarithmic resistance sensitivity with temperature, a, and current, b, as a function of applied magnetic field and bias point within the resistive transition. Results show that these important device parameters exhibit similar oscillatory behavior with applied magnetic field, which in turn affects the signal responsivity and noise, and hence the energy resolution. These results show the significance of the critical current in determining the performance of TESs and hold promise to improve future.

Magical ideation and its relation to lateral preference.

PubMed

Nicholls, Michael E R; Orr, Catherine A; Lindell, Annukka K

2005-11-01

Schizophrenia and schizotypal personality have been linked to sinistrality as well as ambidextrality. The current study clarifies the relation between laterality and schizotypal personality by administering a battery of laterality questionnaires to measure hand, eye, ear, and foot preference in a group of 933 university students. To determine whether the relationship between schizotypy and laterality is limited to self-report measures, performance asymmetries between the hands were measured with tapping rate. There was no difference between dextrals and sinistrals in schizotypal personality, as indexed by the Magical Ideation (MI) scale. MI was higher, however, for individuals with a weak preference for either hand or eye compared to those with a strong dominance. In addition, individuals inconsistent in their lateral preference across modalities showed higher MI scores. Performance asymmetries had no effect on MI scores. This lack of effect was attributed to the inability of performance measures, such as tapping rate, to identify ambidextrals. The results support research linking schizotypal personality to ambidextrality and weak cerebral dominance and demonstrate that the association extends to modalities other than hand preference.

Effect of microwave-enhanced superconductivity in YBa2Cu3O7 Bi-crystalline grain bounda ry weak-links

NASA Technical Reports Server (NTRS)

Fu, C. M.; Chen, C. M.; Lin, H. C.; Wu, K. H.; Juang, J. Y.; Uen, T. M.; Gou, Y. S.

1995-01-01

We have studied systematically the effect of microwave irradiation on the temperature dependent resistivity (R(I) and the current-voltage (I-V) characteristics of YBa2Gu3O(7 - x) (YBCO) bicrystalline grain boundary weak-links (GBWL's), with grain boundary of three different tilt angles. The superconducting transition temperature, T(sub c), has significant enhancement upon microwave irradiation. The microwave enhanced T(sub c) is increased as a function of incident microwave power, but limited to an optimum power level. The GBWL's of 45 deg tilt boundary has shown to be most sensitive to the microwave irradiation power, and the GBWL's of 36.8 deg tilt boundary has displayed a moderate response. In contrast, no enhancement of T(sub c) was observed in the GBWL's of 24 deg tilt boundary, as well as in the uniform films. Under the microwave irradiation, the R(T) dependent is hystertic as the transition taken from superconducting state to normal state and vice versa. Mechanisms associated with the redistribution of nonequilibrium quasiparticles under microwave irradiation are discussed.

Modeling and real time simulation of an HVDC inverter feeding a weak AC system based on commutation failure study.

PubMed

Mankour, Mohamed; Khiat, Mounir; Ghomri, Leila; Chaker, Abdelkader; Bessalah, Mourad

2018-06-01

This paper presents modeling and study of 12-pulse HVDC (High Voltage Direct Current) based on real time simulation where the HVDC inverter is connected to a weak AC system. In goal to study the dynamic performance of the HVDC link, two serious kind of disturbance are applied at HVDC converters where the first one is the single phase to ground AC fault and the second one is the DC link to ground fault. The study is based on two different mode of analysis, which the first is to test the performance of the DC control and the second is focalized to study the effect of the protection function on the system behavior. This real time simulation considers the strength of the AC system to witch is connected and his relativity with the capacity of the DC link. The results obtained are validated by means of RT-lab platform using digital Real time simulator Hypersim (OP-5600), the results carried out show the effect of the DC control and the influence of the protection function to reduce the probability of commutation failures and also for helping inverter to take out from commutation failure even while the DC control fails to eliminate them. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Revised catalog of types of CODES applications implemented using linked state data : crash outcome data evaluation system (CODES)

DOT National Transportation Integrated Search

2000-06-01

The purpose of the Revised Catalog of Types of CODES Applications Implemented Using Linked : State Data (CODES) is to inspire the development of new applications for linked data that support : efforts to reduce death, disability, severity, and health...

Memory Skills of Deaf Learners: Implications and Applications

ERIC Educational Resources Information Center

Hamilton, Harley

2011-01-01

The author reviews research on working memory and short-term memory abilities of deaf individuals, delineating strengths and weaknesses. Among the areas of weakness that are reviewed are sequential recall, processing speed, attention, and memory load. Areas of strengths include free recall, visuospatial recall, imagery, and dual encoding.…

Memory Skills of Deaf Learners: Implications and Applications

ERIC Educational Resources Information Center

Hamilton, Harley

2011-01-01

This paper will review research on working memory and short-term memory abilities of deaf individuals delineating strengths and weaknesses. The areas of memory reviewed include weaknesses such as sequential recall, processing speed, attention, and memory load. Strengths include free recall, visuospatial recall, imagery and dual encoding.…

Influence of Strong versus Weak Fair Employment Policies and Applicant's Sex on Selection Decisions and Salary Recommendations in a Management Simulation.

ERIC Educational Resources Information Center

Rosen, Benson; Mericle, Mary F.

1979-01-01

Strong and weak policies on fair employment were equally effective in counteracting sex bias in selection decisions; however, lower starting salaries were recommended for females compared to males in the strong fair employment policy condition. (Author/IRT)

Generic weak isolated horizons

NASA Astrophysics Data System (ADS)

Chatterjee, Ayan; Ghosh, Amit

2006-12-01

Weak isolated horizon boundary conditions have been relaxed supposedly to their weakest form so that both zeroth and first laws of black hole mechanics hold. This makes the formulation more amenable for applications in both analytic and numerical relativities. It also unifies the phase spaces of non-extremal and extremal black holes.

Lightning Discharges, Cosmic Rays and Climate

NASA Astrophysics Data System (ADS)

Kumar, Sanjay; Siingh, Devendraa; Singh, R. P.; Singh, A. K.; Kamra, A. K.

2018-03-01

The entirety of the Earth's climate system is continuously bombarded by cosmic rays and exhibits about 2000 thunderstorms active at any time of the day all over the globe. Any linkage among these vast systems should have global consequences. Numerous studies done in the past deal with partial links between some selected aspects of this grand linkage. Results of these studies vary from weakly to strongly significant and are not yet complete enough to justify the physical mechanism proposed to explain such links. This review is aimed at presenting the current understanding, based on the past studies on the link between cosmic ray, lightning and climate. The deficiencies in some proposed links are pointed out. Impacts of cosmic rays on engineering systems and the possible effects of cosmic rays on human health are also briefly discussed. Also enumerated are some problems for future work which may help in developing the grand linkage among these three vast systems.

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

NASA Astrophysics Data System (ADS)

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.

User manual of the CATSS system (version 1.0) communication analysis tool for space station

NASA Technical Reports Server (NTRS)

Tsang, C. S.; Su, Y. T.; Lindsey, W. C.

1983-01-01

The Communication Analysis Tool for the Space Station (CATSS) is a FORTRAN language software package capable of predicting the communications links performance for the Space Station (SS) communication and tracking (C & T) system. An interactive software package was currently developed to run on the DEC/VAX computers. The CATSS models and evaluates the various C & T links of the SS, which includes the modulation schemes such as Binary-Phase-Shift-Keying (BPSK), BPSK with Direct Sequence Spread Spectrum (PN/BPSK), and M-ary Frequency-Shift-Keying with Frequency Hopping (FH/MFSK). Optical Space Communication link is also included. CATSS is a C & T system engineering tool used to predict and analyze the system performance for different link environment. Identification of system weaknesses is achieved through evaluation of performance with varying system parameters. System tradeoff for different values of system parameters are made based on the performance prediction.

From Nutrition Plus to Nutrition Driven: how to realize the elusive potential of agriculture for nutrition?

PubMed

Haddad, Lawrence

2013-03-01

Agriculture has the potential to have a bigger impact on nutrition status than it currently does. The pathways between agriculture and nutrition are well known. Yet the evidence on how to increase the impact of agriculture on nutrition is weak. To outline some of the possible reasons for the weak evidentiary link between agriculture and income and to highlight some approaches to incentivizing agriculture to give nutrition a greater priority. A review of literature reviews and other studies. Agriculture does not have a strong poverty and nutrition impact culture, the statistical links between aggregate agriculture and nutrition data are weak, literature reviews to date have not been sufficiently clear on the quality of evidence admitted, and the evidence for the impact of biofortification on nutrition status is positive, but small. Some tools are proposed and described that may be helpful in raising the profile of nutrition outcomes, building nutrition outcomes into impact assessments of agriculture, measuring the commitment to undernutrition reduction, and helping to prioritize nutrition-relevant actions within agriculture. Leadership in agriculture and nutrition is also an understudied issue. Agriculture has a vast potential to increase its impact on nutrition outcomes. We don't know if this potential is being fully realized as yet. I suspect it is not. Tools that help promote the visibility of nutrition within agriculture and the accountability of agriculture toward nutrition can possibly contribute to moving "from Nutrition Plus to Nutrition Driven" agriculture.

A network approach for researching partnerships in health.

PubMed

Lewis, Jenny M

2005-10-07

The last decade has witnessed a significant move towards new modes of governing that are based on coordination and collaboration. In particular, local level partnerships have been widely introduced around the world. There are few comprehensive approaches for researching the effects of these partnerships. The aim of this paper is to outline a network approach that combines structure and agency based explanations to research partnerships in health. Network research based on two Primary Care Partnerships (PCPs) in Victoria is used to demonstrate the utility of this approach. The paper examines multiple types of ties between people (structure), and the use and value of relationships to partners (agency), using interviews with the people involved in two PCPs--one in metropolitan Melbourne and one in a rural area. Network maps of ties based on work, strategic information and policy advice, show that there are many strong connections in both PCPs. Not surprisingly, PCP staff are central and highly connected. Of more interest are the ties that are dependent on these dedicated partnership staff, as they reveal which actors become weakly linked or disconnected without them. Network measures indicate that work ties are the most dispersed and strategic information ties are the most concentrated around fewer people. Divisions of general practice are weakly linked, while local government officials and Department of Human Services (DHS) regional staff appear to play important bridging roles. Finally, the relationships between partners have changed and improved, and most of those interviewed value their new or improved links with partners. Improving service coordination and health promotion planning requires engaging people and building strong relationships. Mapping ties is a useful means for assessing the strengths and weaknesses of partnerships, and network analysis indicates concentration and dispersion, the importance of particular individuals, and the points at which they will fragment. A narrative approach adds an assessment of whether the partnerships are being used and valued. The approach outlined here, which examines structure and agency as separate but related explanations, has much to offer in examining partnerships.

Earth's magnetic field effect on MUF calculation and consequences for hmF2 trend estimates

NASA Astrophysics Data System (ADS)

Elias, Ana G.; Zossi, Bruno S.; Yiğit, Erdal; Saavedra, Zenon; de Haro Barbas, Blas F.

2017-10-01

Knowledge of the state of the upper atmosphere, and in particular of the ionosphere, is essential in several applications such as systems used in radio frequency communications, satellite positioning and navigation. In general, these systems depend on the state and evolution of the ionosphere. In all applications involving the ionosphere an essential task is to determine the path and modifications of ray propagation through the ionospheric plasma. The ionospheric refractive index and the maximum usable frequency (MUF) that can be received over a given distance are some key parameters that are crucial for such technological applications. However, currently the representation of these parameters are in general simplified, neglecting the effects of Earth's magnetic field. The value of M(3000)F2, related to the MUF that can be received over 3000 km is routinely scaled from ionograms using a technique which also neglects the geomagnetic field effects assuming a standard simplified propagation model. M(3000)F2 is expected to be affected by a systematic trend linked to the secular variations of Earth's magnetic field. On the other hand, among the upper atmospheric effects expected from increasing greenhouse gases concentration is the lowering of the F2-layer peak density height, hmF2. This ionospheric parameter is usually estimated using the M(3000)F2 factor, so it would also carry this ;systematic trend;. In this study, the geomagnetic field effect on MUF estimations is analyzed as well as its impact on hmF2 long-term trend estimations. We find that M(3000)F2 increases when the geomagnetic field is included in its calculation, and hence hmF2, estimated using existing methods involving no magnetic field for M(3000)F2 scaling, would present a weak but steady trend linked to these variations which would increase or compensate the few kilometers decrease ( 2 km per decade) expected from greenhouse gases effect.

Local texture and strongly linked conduction in spray-pyrolyzed TlBa2Ca2Cu3O(8+x) deposits

NASA Astrophysics Data System (ADS)

Kroeger, D. M.; Goyal, A.; Specht, E. D.; Wang, Z. L.; Tkaczyk, J. E.; Sutliff, J. A.; Deluca, J. A.

Local texture in polycrystalline TlBa2Ca2 Cu3O(8+x) deposits has been determined from transmission electron microscopy, electron backscatter diffraction patterns and x-ray diffraction. The small-grained deposits had excellent c-axis alignment and contained colonies of grains with similar but not identical a-axis orientations. Most grain boundaries within a colony have small misorientation angles and should not be weak links. It is proposed that long range conduction utilizes a percolative network of small angle grain boundaries at colony intersections.

Breaking through barriers: using technology to address executive function weaknesses and improve student achievement.

PubMed

Schwartz, David M

2014-01-01

Assistive technologies provide significant capabilities for improving student achievement. Improved accessibility, cost, and diversity of applications make integration of technology a powerful tool to compensate for executive function weaknesses and deficits and their impact on student performance, learning, and achievement. These tools can be used to compensate for decreased working memory, poor time management, poor planning and organization, poor initiation, and decreased memory. Assistive technology provides mechanisms to assist students with diverse strengths and weaknesses in mastering core curricular concepts.

Generalized contractive mappings and weakly α-admissible pairs in G-metric spaces.

PubMed

Hussain, N; Parvaneh, V; Hoseini Ghoncheh, S J

2014-01-01

The aim of this paper is to present some coincidence and common fixed point results for generalized (ψ, φ)-contractive mappings using partially weakly G-α-admissibility in the setup of G-metric space. As an application of our results, periodic points of weakly contractive mappings are obtained. We also derive certain new coincidence point and common fixed point theorems in partially ordered G-metric spaces. Moreover, some examples are provided here to illustrate the usability of the obtained results.

Generalized Contractive Mappings and Weakly α-Admissible Pairs in G-Metric Spaces

PubMed Central

Hussain, N.; Parvaneh, V.; Hoseini Ghoncheh, S. J.

2014-01-01

The aim of this paper is to present some coincidence and common fixed point results for generalized (ψ, φ)-contractive mappings using partially weakly G-α-admissibility in the setup of G-metric space. As an application of our results, periodic points of weakly contractive mappings are obtained. We also derive certain new coincidence point and common fixed point theorems in partially ordered G-metric spaces. Moreover, some examples are provided here to illustrate the usability of the obtained results. PMID:25202742

Identical Quantum Particles and Weak Discernibility

NASA Astrophysics Data System (ADS)

Dieks, Dennis; Versteegh, Marijn A. M.

2008-10-01

Saunders has recently claimed that “identical quantum particles” with an anti-symmetric state (fermions) are weakly discernible objects, just like irreflexively related ordinary objects in situations with perfect symmetry (Black’s spheres, for example). Weakly discernible objects have all their qualitative properties in common but nevertheless differ from each other by virtue of (a generalized version of) Leibniz’s principle, since they stand in relations an entity cannot have to itself. This notion of weak discernibility has been criticized as question begging, but we defend and accept it for classical cases likes Black’s spheres. We argue, however, that the quantum mechanical case is different. Here the application of the notion of weak discernibility indeed is question begging and in conflict with standard interpretational ideas. We conclude that the introduction of the conceptual resource of weak discernibility does not change the interpretational status quo in quantum mechanics.

Toward an Application Guide for Safety Integrity Level Allocation in Railway Systems.

PubMed

Ouedraogo, Kiswendsida Abel; Beugin, Julie; El-Koursi, El-Miloudi; Clarhaut, Joffrey; Renaux, Dominique; Lisiecki, Frederic

2018-02-02

The work in the article presents the development of an application guide based on feedback and comments stemming from various railway actors on their practices of SIL allocation to railway safety-related functions. The initial generic methodology for SIL allocation has been updated to be applied to railway rolling stock safety-related functions in order to solve the SIL concept application issues. Various actors dealing with railway SIL allocation problems are the intended target of the methodology; its principles will be summarized in this article with a focus on modifications and precisions made in order to establish a practical guide for railway safety authorities. The methodology is based on the flowchart formalism used in CSM (common safety method) European regulation. It starts with the use of quantitative safety requirements, particularly tolerable hazard rates (THR). THR apportioning rules are applied. On the one hand, the rules are related to classical logical combinations of safety-related functions preventing hazard occurrence. On the other hand, to take into account technical conditions (last safety weak link, functional dependencies, technological complexity, etc.), specific rules implicitly used in existing practices are defined for readjusting some THR values. SIL allocation process based on apportioned and validated THR values is finally illustrated through the example of "emergency brake" subsystems. Some specific SIL allocation rules are also defined and illustrated. © 2018 Society for Risk Analysis.

An AgMIP framework for improved agricultural representation in integrated assessment models

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

Ruane, Alex C.; Rosenzweig, Cynthia; Asseng, Senthold

Integrated assessment models (IAMs) hold great potential to assess how future agricultural systems will be shaped by socioeconomic development, technological innovation, and changing climate conditions. By coupling with climate and crop model emulators, IAMs have the potential to resolve important agricultural feedback loops and identify unintended consequences of socioeconomic development for agricultural systems. Here we propose a framework to develop robust representation of agricultural system responses within IAMs, linking downstream applications with model development and the coordinated evaluation of key climate responses from local to global scales. We survey the strengths and weaknesses of protocol-based assessments linked to the Agriculturalmore » Model Intercomparison and Improvement Project (AgMIP), each utilizing multiple sites and models to evaluate crop response to core climate changes including shifts in carbon dioxide concentration, temperature, and water availability, with some studies further exploring how climate responses are affected by nitrogen levels and adaptation in farm systems. Site-based studies with carefully calibrated models encompass the largest number of activities; however they are limited in their ability to capture the full range of global agricultural system diversity. Representative site networks provide more targeted response information than broadly-sampled networks, with limitations stemming from difficulties in covering the diversity of farming systems. Global gridded crop models provide comprehensive coverage, although with large challenges for calibration and quality control of inputs. Diversity in climate responses underscores that crop model emulators must distinguish between regions and farming system while recognizing model uncertainty. Finally, to bridge the gap between bottom-up and top-down approaches we recommend the deployment of a hybrid climate response system employing a representative network of sites to bias-correct comprehensive gridded simulations, opening the door to accelerated development and a broad range of applications.« less

An AgMIP framework for improved agricultural representation in integrated assessment models

NASA Astrophysics Data System (ADS)

Ruane, Alex C.; Rosenzweig, Cynthia; Asseng, Senthold; Boote, Kenneth J.; Elliott, Joshua; Ewert, Frank; Jones, James W.; Martre, Pierre; McDermid, Sonali P.; Müller, Christoph; Snyder, Abigail; Thorburn, Peter J.

2017-12-01

Integrated assessment models (IAMs) hold great potential to assess how future agricultural systems will be shaped by socioeconomic development, technological innovation, and changing climate conditions. By coupling with climate and crop model emulators, IAMs have the potential to resolve important agricultural feedback loops and identify unintended consequences of socioeconomic development for agricultural systems. Here we propose a framework to develop robust representation of agricultural system responses within IAMs, linking downstream applications with model development and the coordinated evaluation of key climate responses from local to global scales. We survey the strengths and weaknesses of protocol-based assessments linked to the Agricultural Model Intercomparison and Improvement Project (AgMIP), each utilizing multiple sites and models to evaluate crop response to core climate changes including shifts in carbon dioxide concentration, temperature, and water availability, with some studies further exploring how climate responses are affected by nitrogen levels and adaptation in farm systems. Site-based studies with carefully calibrated models encompass the largest number of activities; however they are limited in their ability to capture the full range of global agricultural system diversity. Representative site networks provide more targeted response information than broadly-sampled networks, with limitations stemming from difficulties in covering the diversity of farming systems. Global gridded crop models provide comprehensive coverage, although with large challenges for calibration and quality control of inputs. Diversity in climate responses underscores that crop model emulators must distinguish between regions and farming system while recognizing model uncertainty. Finally, to bridge the gap between bottom-up and top-down approaches we recommend the deployment of a hybrid climate response system employing a representative network of sites to bias-correct comprehensive gridded simulations, opening the door to accelerated development and a broad range of applications.

Lexical Link Analysis (LLA) Application: Improving Web Service to Defense Acquisition Visibility Environment (DAVE)

DTIC Science & Technology

2015-05-01

1 LEXICAL LINK ANALYSIS (LLA) APPLICATION: IMPROVING WEB SERVICE TO DEFENSE ACQUISITION VISIBILITY ENVIRONMENT(DAVE) May 13-14, 2015 Dr. Ying...REPORT DATE MAY 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE Lexical Link Analysis (LLA) Application...Making 3 2 1 3 L L A Methods • Lexical Link Analysis (LLA) Core – LLA Reports and Visualizations • Collaborative Learning Agents (CLA) for

Weak Bond-Based Injectable and Stimuli Responsive Hydrogels for Biomedical Applications

PubMed Central

Ding, Xiaochu; Wang, Yadong

2017-01-01

Here we define hydrogels crosslinked by weak bonds as physical hydrogels. They possess unique features including reversible bonding, shear thinning and stimuli-responsiveness. Unlike covalently crosslinked hydrogels, physical hydrogels do not require triggers to initiate chemical reactions for in situ gelation. The drug can be fully loaded in a pre-formed hydrogel for delivery with minimal cargo leakage during injection. These benefits make physical hydrogels useful as delivery vehicles for applications in biomedical engineering. This review focuses on recent advances of physical hydrogels crosslinked by weak bonds: hydrogen bonds, ionic interactions, host-guest chemistry, hydrophobic interactions, coordination bonds and π-π stacking interactions. Understanding the principles and the state of the art of gels with these dynamic bonds may give rise to breakthroughs in many biomedical research areas including drug delivery and tissue engineering. PMID:29062484

Integrated Giant Magnetoresistance Technology for Approachable Weak Biomagnetic Signal Detections

PubMed Central

Shen, Hui-Min; Hu, Liang; Fu, Xin

2018-01-01

With the extensive applications of biomagnetic signals derived from active biological tissue in both clinical diagnoses and human-computer-interaction, there is an increasing need for approachable weak biomagnetic sensing technology. The inherent merits of giant magnetoresistance (GMR) and its high integration with multiple technologies makes it possible to detect weak biomagnetic signals with micron-sized, non-cooled and low-cost sensors, considering that the magnetic field intensity attenuates rapidly with distance. This paper focuses on the state-of-art in integrated GMR technology for approachable biomagnetic sensing from the perspective of discipline fusion between them. The progress in integrated GMR to overcome the challenges in weak biomagnetic signal detection towards high resolution portable applications is addressed. The various strategies for 1/f noise reduction and sensitivity enhancement in integrated GMR technology for sub-pT biomagnetic signal recording are discussed. In this paper, we review the developments of integrated GMR technology for in vivo/vitro biomagnetic source imaging and demonstrate how integrated GMR can be utilized for biomagnetic field detection. Since the field sensitivity of integrated GMR technology is being pushed to fT/Hz0.5 with the focused efforts, it is believed that the potential of integrated GMR technology will make it preferred choice in weak biomagnetic signal detection in the future. PMID:29316670

Integrated Giant Magnetoresistance Technology for Approachable Weak Biomagnetic Signal Detections.

PubMed

Shen, Hui-Min; Hu, Liang; Fu, Xin

2018-01-07

With the extensive applications of biomagnetic signals derived from active biological tissue in both clinical diagnoses and human-computer-interaction, there is an increasing need for approachable weak biomagnetic sensing technology. The inherent merits of giant magnetoresistance (GMR) and its high integration with multiple technologies makes it possible to detect weak biomagnetic signals with micron-sized, non-cooled and low-cost sensors, considering that the magnetic field intensity attenuates rapidly with distance. This paper focuses on the state-of-art in integrated GMR technology for approachable biomagnetic sensing from the perspective of discipline fusion between them. The progress in integrated GMR to overcome the challenges in weak biomagnetic signal detection towards high resolution portable applications is addressed. The various strategies for 1/ f noise reduction and sensitivity enhancement in integrated GMR technology for sub-pT biomagnetic signal recording are discussed. In this paper, we review the developments of integrated GMR technology for in vivo/vitro biomagnetic source imaging and demonstrate how integrated GMR can be utilized for biomagnetic field detection. Since the field sensitivity of integrated GMR technology is being pushed to fT/Hz 0.5 with the focused efforts, it is believed that the potential of integrated GMR technology will make it preferred choice in weak biomagnetic signal detection in the future.

Probability of Loss of Assured Safety in Systems with Multiple Time-Dependent Failure Modes: Incorporation of Delayed Link Failure in the Presence of Aleatory Uncertainty.

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

Helton, Jon C.; Brooks, Dusty Marie; Sallaberry, Cedric Jean-Marie.

Probability of loss of assured safety (PLOAS) is modeled for weak link (WL)/strong link (SL) systems in which one or more WLs or SLs could potentially degrade into a precursor condition to link failure that will be followed by an actual failure after some amount of elapsed time. The following topics are considered: (i) Definition of precursor occurrence time cumulative distribution functions (CDFs) for individual WLs and SLs, (ii) Formal representation of PLOAS with constant delay times, (iii) Approximation and illustration of PLOAS with constant delay times, (iv) Formal representation of PLOAS with aleatory uncertainty in delay times, (v) Approximationmore » and illustration of PLOAS with aleatory uncertainty in delay times, (vi) Formal representation of PLOAS with delay times defined by functions of link properties at occurrence times for failure precursors, (vii) Approximation and illustration of PLOAS with delay times defined by functions of link properties at occurrence times for failure precursors, and (viii) Procedures for the verification of PLOAS calculations for the three indicated definitions of delayed link failure.« less

Optimization design about gimbal structure of high-precision autonomous celestial navigation tracking mirror system

NASA Astrophysics Data System (ADS)

Huang, Wei; Yang, Xiao-xu; Han, Jun-feng; Wei, Yu; Zhang, Jing; Xie, Mei-lin; Yue, Peng

2016-01-01

High precision tracking platform of celestial navigation with control mirror servo structure form, to solve the disadvantages of big volume and rotational inertia, slow response speed, and so on. It improved the stability and tracking accuracy of platform. Due to optical sensor and mirror are installed on the middle-gimbal, stiffness and resonant frequency requirement for high. Based on the application of finite element modality analysis theory, doing Research on dynamic characteristics of the middle-gimbal, and ANSYS was used for the finite element dynamic emulator analysis. According to the result of the computer to find out the weak links of the structure, and Put forward improvement suggestions and reanalysis. The lowest resonant frequency of optimization middle-gimbal avoid the bandwidth of the platform servo mechanism, and much higher than the disturbance frequency of carrier aircraft, and reduces mechanical resonance of the framework. Reaching provides a theoretical basis for the whole machine structure optimization design of high-precision of autonomous Celestial navigation tracking mirror system.

Free-space quantum cryptography with quantum and telecom communication channels

NASA Astrophysics Data System (ADS)

Toyoshima, Morio; Takayama, Yoshihisa; Klaus, Werner; Kunimori, Hiroo; Fujiwara, Mikio; Sasaki, Masahide

2008-07-01

Quantum cryptography is a new technique that uses the laws of physics to transmit information securely. In such systems, the vehicle to transfer quantum information is a single photon. However, the transmission distance is limited by the absorption of photons in an optical fiber in which the maximum demonstrated range is about 100 km. Free-space quantum cryptography between a ground station and a satellite is a way of sending the quantum information further distances than that with optical fibers since there is no birefringence effect in the atmosphere. At the National Institute of Information and Communications Technology (NICT), the laser communication demonstration between the NICT optical ground station and a low earth orbit satellite was successfully conducted in 2006. For such space communication links, free-space quantum cryptography is considered to be an important application in the future. We have developed a prototype system for free-space quantum cryptography using a weak coherent light and a telecom communication channel. The preliminary results are presented.

Acid-Labile Poly(glycidyl methacrylate)-Based Star Gene Vectors.

PubMed

Yang, Yan-Yu; Hu, Hao; Wang, Xing; Yang, Fei; Shen, Hong; Xu, Fu-Jian; Wu, De-Cheng

2015-06-10

It was recently reported that ethanolamine-functionalized poly(glycidyl methacrylate) (PGEA) possesses great potential applications in gene therapy due to its good biocompatibility and high transfection efficiency. Importing responsivity into PGEA vectors would further improve their performances. Herein, a series of responsive star-shaped vectors, acetaled β-cyclodextrin-PGEAs (A-CD-PGEAs) consisting of a β-CD core and five PGEA arms linked by acid-labile acetal groups, were proposed and characterized as therapeutic pDNA vectors. The A-CD-PGEAs owned abundant hydroxyl groups to shield extra positive charges of A-CD-PGEAs/pDNA complexes, and the star structure could decrease charge density. The incorporation of acetal linkers endowed A-CD-PGEAs with pH responsivity and degradation. In weakly acidic endosome, the broken acetal linkers resulted in decomposition of A-CD-PGEAs and morphological transformation of A-CD-PGEAs/pDNA complexes, lowering cytotoxicity and accelerating release of pDNA. In comparison with control CD-PGEAs without acetal linkers, A-CD-PGEAs exhibited significantly better transfection performances.

A Deconstruction Lattice Description of the D1/D5 Brane World-Volume Gauge Theory

DOE PAGES

Giedt, Joel

2011-01-01

I genermore » alize the deconstruction lattice formulation of Endres and Kaplan to two-dimensional super-QCD with eight supercharges, denoted by (4,4), and bifundamental matter. I specialize to a particularly interesting (4,4) gauge theory, with gauge group U ( N c ) × U ( N f ) , and U ( N f ) being weakly gauged. It describes the infrared limit of the D1/D5 brane system, which has been studied extensively as an example of the AdS 3 /CFT 2 correspondence. The construction here preserves two supercharges exactly and has a lattice structure quite similar to that which has previously appeared in the deconstruction approach, that is, site, link, and diagonal fields with both the Bose and Fermi statistics. I remark on possible applications of the lattice theory that would test the AdS 3 /CFT 2 correspondence, particularly one that would exploit the recent worldsheet instanton analysis of Chen and Tong.« less

Surveillance data for waterborne illness detection: an assessment following a massive waterborne outbreak of Cryptosporidium infection.

PubMed Central

Proctor, M. E.; Blair, K. A.; Davis, J. P.

1998-01-01

Following the 1993 Milwaukee cryptosporidiosis outbreak, we examined data from eight sources available during the time of the outbreak. Although there was a remarkable temporal correspondence of surveillance peaks, the most timely data involved use of systems in which personnel with existing close ties to public health programmes perceived the importance of providing information despite workload constraints associated with an outbreak. During the investigation, surveillance systems which could be easily linked with laboratory data, were flexible in adding new variables, and which demonstrated low baseline variability were most useful. Geographically fixed nursing home residents served as an ideal population with nonconfounded exposures. Use of surrogate measurements of morbidity can trigger worthwhile public health responses in advance of laboratory-confirmed diagnosis and help reduce total morbidity associated with an outbreak. This report describes the relative strengths and weaknesses of these surveillance methods for community-wide waterborne illness detection and their application in outbreak decision making. PMID:9528817

Tectonics and volcanism in central Mexico - A Landsat Thematic Mapper perspective

NASA Technical Reports Server (NTRS)

Johnson, C. A.; Harrison, C. G. A.

1989-01-01

Digitally enhanced Landsat Thematic Mapper (TM) images were used to map neotectonic deformation in central Mexico. This region has been studied for decades using a variety of geological and geophysical techniques, but synoptic mapping of neotectonic activity and major fault zones there, and an evaluation of their regional relationship to the character and location of volcanism were not previously possible until the application of synoptic, high resolution satellite imagery. Interpretation of the TM images shows that the tectonic deformation is closely linked in time and space to the dominantly calc-alkaline volcanics of the Mexican Volcanic Belt (MVB). The eruptive style and distribution of the volcanics is clearly related to the deformation resulting from relative motions of three large crustal blocks south of the MVB. Therefore, zones of weakness within the crust of central Mexico, which may be inherited from earlier episodes of deformation, are a principal factor controlling the oblique orientation of the MVB relative to the Acapulco Trench.

Forging a Link between Research and Pedagogy: A Holistic Framework for Evaluating Business English Materials

ERIC Educational Resources Information Center

Chan, Clarice S. C.

2009-01-01

In the last two decades, a great deal of applied linguistics research has been conducted in different areas of business English. However, despite many highly relevant research findings, the interface between research and pedagogy remains weak. One reason behind this lack of interface is that research findings from different studies are rarely…

Strong and weak plasma response to dietary carotenoids identified by cluster analysis and linked to beta-carotene 15,15'-monooxygenase 1 single nucleotide polymorphisms

USDA-ARS?s Scientific Manuscript database

The mechanisms as well the genetics underlying bioavailability and metabolism of carotenoids in humans remains unclear. The individual temporal response of plasma carotenoids was analyzed in adults who consumed carotenoid-containing juices on a controlled-diet study using cluster analysis. Treatmen...

Feeling Caught between Parents: Adult Children's Relations with Parents and Subjective Well-Being

ERIC Educational Resources Information Center

Amato, Paul R.; Afifi, Tamara D.

2006-01-01

Research on divorce has found that adolescents' feelings of being caught between parents are linked to internalizing problems and weak parent-child relationships. The present study estimates the effects of marital discord, as well as divorce, on young adult offspring's feelings of being caught in the middle (N=632). Children with parents in…

Aquatic biodiversity in forests: a weak link in ecosystem services resilience

Treesearch

Brooke E. Penaluna; Deanna H. Olson; Rebecca L. Flitcroft; Matthew A. Weber; J. Ryan Bellmore; Steven M. Wondzell; Jason B. Dunham; Sherri L. Johnson; Gordon H. Reeves

2017-01-01

The diversity of aquatic ecosystems is being quickly reduced on many continents, warranting a closer examination of the consequences for ecological integrity and ecosystem services. Here we describe intermediate and final ecosystem services derived from aquatic biodiversity in forests. We include a summary of the factors framing the assembly of aquatic biodiversity in...

Ultra-high performance fiber-reinforced concrete (UHPFRC) for infrastructure rehabilitation : volume 1 : evaluation of ultra high strength concrete (UHSC) in joints of bridge girders.

DOT National Transportation Integrated Search

2017-03-01

Joints are often considered as the weak link in a structure and often deterioration of the structure initiates from the : joints. Joints transfer the stresses from super-structure to sub-structure and in this process are subjected to large : transfer...

Negative Life Events and Adolescent Suicidal Behavior: A Critical Analysis from the Stress Process Perspective.

ERIC Educational Resources Information Center

Sandin, Bonifacio; Chorot, Paloma; Santed, Miguel A.; Valiente, Rosa M.; Joiner, Thomas E., Jr.

1998-01-01

Empirical evidence relating negative life events and adolescent suicidal behavior is reviewed. The contribution of life events tends to be moderate or weak. A stress process model is presented. Past research has not incorporated mediating and moderating variables into pathways that link psychosocial stressors and suicidal outcomes, providing a…

Individual Differences in (Non-Visual) Processing Style Predict the Face Inversion Effect

ERIC Educational Resources Information Center

Wyer, Natalie A.; Martin, Douglas; Pickup, Tracey; Macrae, C. Neil

2012-01-01

Recent research suggests that individuals with relatively weak global precedence (i.e., a smaller propensity to view visual stimuli in a configural manner) show a reduced face inversion effect (FIE). Coupled with such findings, a number of recent studies have demonstrated links between an advantage for feature-based processing and the presentation…

TV Fights: Women and Men in Interpersonal Arguments on Prime-Time Television Dramas.

ERIC Educational Resources Information Center

Brinson, Susan L.

1992-01-01

Studies the behaviors of women and men represented in interpersonal arguments in prime-time television dramas. Finds a weak link between actual argument behaviors and those on television, thereby socializing viewers in a manner inconsistent with reality. Suggests that television arguments are guided more by the needs of the medium that a need to…

Middle Grades to High School: Mending a Weak Link. Research Brief.

ERIC Educational Resources Information Center

Cooney, Sondra; Bottoms, Gene

This research brief describes a study of the readiness for high school of eighth-graders who participated in the Southern Regional Education Board's (SREB) Middle Grades Assessment in spring 2000. The assessment included testing in reading, math, and science, and surveys of students and teachers. Following the 2000-01 school year, SREB gathered…

Linking hearts and minds in couple interactions: intentions, attributions, and overriding sentiments.

PubMed

Waldinger, Robert J; Schulz, Marc S

2006-09-01

This study examined the role of emotion and relationship satisfaction in shaping attributions about a partner's intentions in couple interactions. Using video recall, participants (N = 156 couples) reported on their own and their partner's intentions and emotions during affective moments of a discussion about an upsetting event. Links were found between relationship satisfaction and factor-analytically derived intention and attribution scales. Attributions about a partner's intentions were weakly to moderately correlated with the partner's self-reported intentions. Relationship satisfaction accounted for part of the discrepancy between self-reported intentions and partner attributions. Emotions mediated the links between relationship satisfaction and attributions, suggesting that clinicians working with distressed couples should pay more attention to the emotional climate in which attributions are made. Copyright (c) 2006 APA, all rights reserved.

Using Aspen to Teach Chromatographic Bioprocessing: A Case Study in Weak Partitioning Chromatography for Biotechnology Applications

ERIC Educational Resources Information Center

Evans, Steven T.; Huang, Xinqun; Cramer, Steven M.

2010-01-01

The commercial simulator Aspen Chromatography was employed to study and optimize an important new industrial separation process, weak partitioning chromatography. This case study on antibody purification was implemented in a chromatographic separations course. Parametric simulations were performed to investigate the effect of operating parameters…

Congenital myasthenic syndromes due to mutations in ALG2 and ALG14.

PubMed

Cossins, Judith; Belaya, Katsiaryna; Hicks, Debbie; Salih, Mustafa A; Finlayson, Sarah; Carboni, Nicola; Liu, Wei Wei; Maxwell, Susan; Zoltowska, Katarzyna; Farsani, Golara Torabi; Laval, Steven; Seidhamed, Mohammed Zain; Donnelly, Peter; Bentley, David; McGowan, Simon J; Müller, Juliane; Palace, Jacqueline; Lochmüller, Hanns; Beeson, David

2013-03-01

Congenital myasthenic syndromes are a heterogeneous group of inherited disorders that arise from impaired signal transmission at the neuromuscular synapse. They are characterized by fatigable muscle weakness. We performed linkage analysis, whole-exome and whole-genome sequencing to determine the underlying defect in patients with an inherited limb-girdle pattern of myasthenic weakness. We identify ALG14 and ALG2 as novel genes in which mutations cause a congenital myasthenic syndrome. Through analogy with yeast, ALG14 is thought to form a multiglycosyltransferase complex with ALG13 and DPAGT1 that catalyses the first two committed steps of asparagine-linked protein glycosylation. We show that ALG14 is concentrated at the muscle motor endplates and small interfering RNA silencing of ALG14 results in reduced cell-surface expression of muscle acetylcholine receptor expressed in human embryonic kidney 293 cells. ALG2 is an alpha-1,3-mannosyltransferase that also catalyses early steps in the asparagine-linked glycosylation pathway. Mutations were identified in two kinships, with mutation ALG2p.Val68Gly found to severely reduce ALG2 expression both in patient muscle, and in cell cultures. Identification of DPAGT1, ALG14 and ALG2 mutations as a cause of congenital myasthenic syndrome underscores the importance of asparagine-linked protein glycosylation for proper functioning of the neuromuscular junction. These syndromes form part of the wider spectrum of congenital disorders of glycosylation caused by impaired asparagine-linked glycosylation. It is likely that further genes encoding components of this pathway will be associated with congenital myasthenic syndromes or impaired neuromuscular transmission as part of a more severe multisystem disorder. Our findings suggest that treatment with cholinesterase inhibitors may improve muscle function in many of the congenital disorders of glycosylation.

The innovation value chain.

PubMed

Hansen, Morten T; Birkinshaw, Julian

2007-06-01

The challenges of coming up with fresh ideas and realizing profits from them are different for every company. One firm may excel at finding good ideas but may have weak systems for bringing them to market. Another organization may have a terrific process for funding and rolling out new products and services but a shortage of concepts to develop. In this article, Hansen and Birkinshaw caution executives against using the latest and greatest innovation approaches and tools without understanding the unique deficiencies in their companies' innovation systems. They offer a framework for evaluating innovation performance: the innovation value chain. It comprises the three main phases of innovation (idea generation, conversion, and diffusion) as well as the critical activities performed during those phases (looking for ideas inside your unit; looking for them in other units; looking for them externally; selecting ideas; funding them; and promoting and spreading ideas companywide). Using this framework, managers get an end-to-end view of their innovation efforts. They can pinpoint their weakest links and tailor innovation best practices appropriately to strengthen those links. Companies typically succumb to one of three broad "weakest-link" scenarios. They are idea poor, conversion poor, or diffusion poor. The article looks at the ways smart companies - including Intuit, P&G, Sara Lee, Shell, and Siemens- modify the best innovation practices and apply them to address those organizations' individual needs and flaws. The authors warn that adopting the chain-based view of innovation requires new measures of what can be delivered by each link in the chain. The approach also entails new roles for employees "external scouts" and "internal evangelists," for example. Indeed, in their search for new hires, companies should seek out those candidates who can help address particular weaknesses in the innovation value chain.

Effect of carbon nanotube functionalization on mechanical and thermal properties of cross-linked epoxy-carbon nanotube nanocomposites: role of strengthening the interfacial interactions.

PubMed

Khare, Ketan S; Khabaz, Fardin; Khare, Rajesh

2014-05-14

We have used amido-amine functionalized carbon nanotubes (CNTs) that form covalent bonds with cross-linked epoxy matrices to elucidate the role of the matrix-filler interphase in the enhancement of mechanical and thermal properties in these nanocomposites. For the base case of nanocomposites of cross-linked epoxy and pristine single-walled CNTs, our previous work (Khare, K. S.; Khare, R. J. Phys. Chem. B 2013, 117, 7444-7454) has shown that weak matrix-filler interactions cause the interphase region in the nanocomposite to be more compressible. Furthermore, because of the weak matrix-filler interactions, the nanocomposite containing dispersed pristine CNTs has a glass transition temperature (Tg) that is ∼66 K lower than the neat polymer. In this work, we demonstrate that in spite of the presence of stiff CNTs in the nanocomposite, the Young's modulus of the nanocomposite containing dispersed pristine CNTs is virtually unchanged compared to the neat cross-linked epoxy. This observation suggests that the compressibility of the matrix-filler interphase interferes with the ability of the CNTs to reinforce the matrix. Furthermore, when the compressibility of the interphase is reduced by the use of amido-amine functionalized CNTs, the mechanical reinforcement due to the filler is more effective, resulting in a ∼50% increase in the Young's modulus compared to the neat cross-linked epoxy. Correspondingly, the functionalization of the CNTs also led to a recovery in the Tg making it effectively the same as the neat polymer and also resulted in a ∼12% increase in the thermal conductivity of the nanocomposite containing functionalized CNTs compared to that containing pristine CNTs. These results demonstrate that the functionalization of the CNTs facilitates the transfer of both mechanical load and thermal energy across the matrix-filler interface.

The role of living/controlled radical polymerization in the formation of improved imprinted polymers.

PubMed

Salian, Vishal D; Vaughan, Asa D; Byrne, Mark E

2012-06-01

In this work, living/controlled radical polymerization (LRP) is compared with conventional free radical polymerization in the creation of highly and weakly cross-linked imprinted poly(methacrylic acid-co-ethylene glycol dimethacrylate) networks. It elucidates, for the first time, the effect of LRP on the chain level and begins to explain why the efficiency of the imprinting process is improved using LRP. Imprinted polymers produced via LRP exhibited significantly higher template affinity and capacity compared with polymers prepared using conventional methods. The use of LRP in the creation of highly cross-linked imprinted polymers resulted in a fourfold increase in binding capacity without a decrease in affinity; whereas weakly cross-linked gels demonstrated a nearly threefold increase in binding capacity at equivalent affinity when LRP was used. In addition, by adjusting the double bond conversion, we can choose to increase either the capacity or the affinity in highly cross-linked imprinted polymers, thus allowing the creation of imprinted polymers with tailorable binding parameters. Using free radical polymerization in the creation of polymer chains, as the template-monomer ratio increased, the average molecular weight of the polymer chains decreased despite a slight increase in the double bond conversion. Thus, the polymer chains formed were shorter but greater in number. Using LRP neutralized the effect of the template. The addition of chain transfer agent resulted in slow, uniform, simultaneous chain growth, resulting in the formation of longer more monodisperse chains. Reaction analysis revealed that propagation time was extended threefold in the formation of highly cross-linked polymers when LRP techniques were used. This delayed the transition to the diffusion-controlled stage of the reaction, which in turn led to the observed enhanced binding properties, decreased polydispersity in the chains, and a more homogeneous macromolecular architecture. Copyright © 2012 John Wiley & Sons, Ltd.

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

Lu, Z. X.; Wang, W. X.; Diamond, P. H.

We report that intrinsic torque, which can be generated by turbulent stresses, can induce toroidal rotation in a tokamak plasma at rest without direct momentum injection. Reversals in intrinsic torque have been inferred from the observation of toroidal velocity changes in recent lower hybrid current drive (LHCD) experiments. Here we focus on understanding the cause of LHCD-induced intrinsic torque reversal using gyrokinetic simulations and theoretical analyses. A new mechanism for the intrinsic torque reversal linked to magnetic shear (sˆ) effects on the turbulence spectrum is identified. This reversal is a consequence of the ballooning structure at weak sˆ . Basedmore » on realistic profiles from the Alcator C-Mod LHCD experiments, simulations demonstrate that the intrinsic torque reverses for weak sˆ discharges and that the value of sˆ crit is consistent with the experimental results sˆ exp crit [Rice et al., Phys. Rev. Lett. 111, 125003 (2013)]. In conclusion, the consideration of this intrinsic torque feature in our work is important for the understanding of rotation profile generation at weak and its consequent impact on macro-instability stabilization and micro-turbulence reduction, which is crucial for ITER. It is also relevant to internal transport barrier formation at negative or weakly positive sˆ .« less

Transcranial Alternating Current Stimulation Attenuates Neuronal Adaptation.

PubMed

Kar, Kohitij; Duijnhouwer, Jacob; Krekelberg, Bart

2017-03-01

We previously showed that brief application of 2 mA (peak-to-peak) transcranial currents alternating at 10 Hz significantly reduces motion adaptation in humans. This is but one of many behavioral studies showing that weak currents applied to the scalp modulate neural processing. Transcranial stimulation has been shown to improve perception, learning, and a range of clinical symptoms. Few studies, however, have measured the neural consequences of transcranial current stimulation. We capitalized on the strong link between motion perception and neural activity in the middle temporal (MT) area of the macaque monkey to study the neural mechanisms that underlie the behavioral consequences of transcranial alternating current stimulation. First, we observed that 2 mA currents generated substantial intracranial fields, which were much stronger in the stimulated hemisphere (0.12 V/m) than on the opposite side of the brain (0.03 V/m). Second, we found that brief application of transcranial alternating current stimulation at 10 Hz reduced spike-frequency adaptation of MT neurons and led to a broadband increase in the power spectrum of local field potentials. Together, these findings provide a direct demonstration that weak electric fields applied to the scalp significantly affect neural processing in the primate brain and that this includes a hitherto unknown mechanism that attenuates sensory adaptation. SIGNIFICANCE STATEMENT Transcranial stimulation has been claimed to improve perception, learning, and a range of clinical symptoms. Little is known, however, how transcranial current stimulation generates such effects, and the search for better stimulation protocols proceeds largely by trial and error. We investigated, for the first time, the neural consequences of stimulation in the monkey brain. We found that even brief application of alternating current stimulation reduced the effects of adaptation on single-neuron firing rates and local field potentials; this mechanistic insight explains previous behavioral findings and suggests a novel way to modulate neural information processing using transcranial currents. In addition, by developing an animal model to help understand transcranial stimulation, this study will aid the rational design of stimulation protocols for the treatment of mental illnesses, and the improvement of perception and learning. Copyright © 2017 the authors 0270-6474/17/372325-11$15.00/0.

Hermite Functional Link Neural Network for Solving the Van der Pol-Duffing Oscillator Equation.

PubMed

Mall, Susmita; Chakraverty, S

2016-08-01

Hermite polynomial-based functional link artificial neural network (FLANN) is proposed here to solve the Van der Pol-Duffing oscillator equation. A single-layer hermite neural network (HeNN) model is used, where a hidden layer is replaced by expansion block of input pattern using Hermite orthogonal polynomials. A feedforward neural network model with the unsupervised error backpropagation principle is used for modifying the network parameters and minimizing the computed error function. The Van der Pol-Duffing and Duffing oscillator equations may not be solved exactly. Here, approximate solutions of these types of equations have been obtained by applying the HeNN model for the first time. Three mathematical example problems and two real-life application problems of Van der Pol-Duffing oscillator equation, extracting the features of early mechanical failure signal and weak signal detection problems, are solved using the proposed HeNN method. HeNN approximate solutions have been compared with results obtained by the well known Runge-Kutta method. Computed results are depicted in term of graphs. After training the HeNN model, we may use it as a black box to get numerical results at any arbitrary point in the domain. Thus, the proposed HeNN method is efficient. The results reveal that this method is reliable and can be applied to other nonlinear problems too.

Suppression of activation energy and superconductivity by the addition of Al{sub 2}O{sub 3} nanoparticles in CuTl-1223 matrix

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

Jabbar, Abdul; Qasim, Irfan; Mumtaz, M.

2014-05-28

Low anisotropic (Cu{sub 0.5}Tl{sub 0.5})Ba{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10−δ} (CuTl-1223) high T{sub c} superconducting matrix was synthesized by solid-state reaction and Al{sub 2}O{sub 3} nanoparticles were prepared separately by co-precipitation method. Al{sub 2}O{sub 3} nanoparticles were added with different concentrations during the final sintering cycle of CuTl-1223 superconducting matrix to get the required (Al{sub 2}O{sub 3}){sub y}/CuTl-1223, y = 0.0, 0.5, 0.7, 1.0, and 1.5 wt. %, composites. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy, energy dispersive X-ray, and dc-resistivity (ρ) measurements. The activation energy and superconductivity were suppressed with increasing concentration of Al{sub 2}O{sub 3} nanoparticles in (CuTl-1223) matrix.more » The XRD analysis showed that the addition of Al{sub 2}O{sub 3} nanoparticles did not affect the crystal structure of the parent CuTl-1223 superconducting phase. The suppression of activation energy and superconducting properties is most probably due to weak flux pinning in the samples. The possible reason of weak flux pinning is reduction of weak links and enhanced inter-grain coupling due to the presence of Al{sub 2}O{sub 3} nanoparticles at the grain boundaries. The presence of Al{sub 2}O{sub 3} nanoparticles at the grain boundaries possibly reduced the number of flux pinning centers, which were present in the form of weak links in the pure CuTl-1223 superconducting matrix. The increase in the values of inter-grain coupling (α) deduced from the fluctuation induced conductivity analysis with the increased concentration of Al{sub 2}O{sub 3} nanoparticles is a theoretical evidence of improved inter-grain coupling.« less

A new symmetrical quasi-classical model for electronically non-adiabatic processes: Application to the case of weak non-adiabatic coupling

DOE PAGES

Cotton, Stephen J.; Miller, William H.

2016-10-14

Previous work has shown how a symmetrical quasi-classical (SQC) windowing procedure can be used to quantize the initial and final electronic degrees of freedom in the Meyer-Miller (MM) classical vibronic (i.e, nuclear + electronic) Hamiltonian, and that the approach provides a very good description of electronically non-adiabatic processes within a standard classical molecular dynamics framework for a number of benchmark problems. This study explores application of the SQC/MM approach to the case of very weak non-adiabatic coupling between the electronic states, showing (as anticipated) how the standard SQC/MM approach used to date fails in this limit, and then devises amore » new SQC windowing scheme to deal with it. Finally, application of this new SQC model to a variety of realistic benchmark systems shows that the new model not only treats the weak coupling case extremely well, but it is also seen to describe the “normal” regime (of electronic transition probabilities ≳ 0.1) even more accurately than the previous “standard” model.« less

A new symmetrical quasi-classical model for electronically non-adiabatic processes: Application to the case of weak non-adiabatic coupling

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

Cotton, Stephen J.; Miller, William H.

Previous work has shown how a symmetrical quasi-classical (SQC) windowing procedure can be used to quantize the initial and final electronic degrees of freedom in the Meyer-Miller (MM) classical vibronic (i.e, nuclear + electronic) Hamiltonian, and that the approach provides a very good description of electronically non-adiabatic processes within a standard classical molecular dynamics framework for a number of benchmark problems. This study explores application of the SQC/MM approach to the case of very weak non-adiabatic coupling between the electronic states, showing (as anticipated) how the standard SQC/MM approach used to date fails in this limit, and then devises amore » new SQC windowing scheme to deal with it. Finally, application of this new SQC model to a variety of realistic benchmark systems shows that the new model not only treats the weak coupling case extremely well, but it is also seen to describe the “normal” regime (of electronic transition probabilities ≳ 0.1) even more accurately than the previous “standard” model.« less

The current structure of key actors involved in research on land and soil degradation

NASA Astrophysics Data System (ADS)

Escadafal, Richard; Barbero, Celia; Exbrayat, Williams; Marques, Maria Jose; Ruiz, Manuel; El Haddadi, Anass; Akhtar-Schuster, Mariam

2013-04-01

Land and soil conservation topics, the final mandate of the United Convention to Combat desertification in drylands, have been diagnosed as still suffering from a lack of guidance. On the contrary, climate change and biodiversity issues -the other two big subjects of the Rio Conventions- seem to progress and may benefit from the advice of international panels. Arguably the weakness of policy measures and hence the application of scientific knowledge by land users and stakeholders could be the expression of an inadequate research organization and a lack of ability to channel their findings. In order to better understand the size, breadth and depth of the scientific communities involved in providing advice to this convention and to other bodies, this study explores the corpus of international publications dealing with land and/or with soils. A database of several thousands records including a significant part of the literature published so far was performed using the Web of Science and other socio-economic databases such as FRANCIS and CAIRN. We extracted hidden information using bibliometric methods and data mining applied to these scientific publications to map the key actors (laboratories, teams, institutions) involved in research on land and on soils. Several filters were applied to the databases in combination with the word "desertification". The further use of Tetralogie software merges databases, analyses similarities and differences between keywords, disciplines, authors and regions and identifies obvious clusters. Assessing their commonalities and differences, the visualisation of links and gaps between scientists, organisations, policymakers and other stakeholders is possible. The interpretation of the 'clouds' of disciplines, keywords, and techniques will enhance the understanding of interconnections between them; ultimately this will allow diagnosing some of their strengths and weaknesses. This may help explain why land and soil degradation remains a serious global problem that lacks sufficient attention. We hope that this study will contribute to clarify the scientific landscape at stake to remediate possible weaknesses in the future.

Boiling points of halogenated ethanes: an explanatory model implicating weak intermolecular hydrogen-halogen bonding.

PubMed

Beauchamp, Guy

2008-10-23

This study explores via structural clues the influence of weak intermolecular hydrogen-halogen bonds on the boiling point of halogenated ethanes. The plot of boiling points of 86 halogenated ethanes versus the molar refraction (linked to polarizability) reveals a series of straight lines, each corresponding to one of nine possible arrangements of hydrogen and halogen atoms on the two-carbon skeleton. A multiple linear regression model of the boiling points could be designed based on molar refraction and subgroup structure as independent variables (R(2) = 0.995, standard error of boiling point 4.2 degrees C). The model is discussed in view of the fact that molar refraction can account for approximately 83.0% of the observed variation in boiling point, while 16.5% could be ascribed to weak C-X...H-C intermolecular interactions. The difference in the observed boiling point of molecules having similar molar refraction values but differing in hydrogen-halogen intermolecular bonds can reach as much as 90 degrees C.

IMPACT OF GRAVITY LOADING ON POST-STROKE REACHING AND ITS RELATIONSHIP TO WEAKNESS

PubMed Central

Beer, Randall F.; Ellis, Michael D.; Holubar, Bradley G.; Dewald, Julius P.A.

2010-01-01

The ability to extend the elbow following stroke depends on the magnitude and direction of torques acting at the shoulder. The mechanisms underlying this link remain unclear. The purpose of this study was to evaluate whether the effects of shoulder loading on elbow function were related to weakness or its distribution in the paretic limb. Ten subjects with longstanding hemiparesis performed movements with the arm either passively supported against gravity by an air bearing, or by activation of shoulder muscles. Isometric maximum voluntary torques at the elbow and shoulder were measured using a load cell. The speed and range of elbow extension movements were negatively impacted by actively supporting the paretic limb against gravity. However, the effects of gravity loading were not related to proximal weakness or abnormalities in the elbow flexor–extensor strength balance. The findings support the existence of abnormal descending motor commands that constrain the ability of stroke survivors to generate elbow extension torque in combination with abduction torque at the shoulder. PMID:17486581

Impact of gravity loading on post-stroke reaching and its relationship to weakness.

PubMed

Beer, Randall F; Ellis, Michael D; Holubar, Bradley G; Dewald, Julius P A

2007-08-01

The ability to extend the elbow following stroke depends on the magnitude and direction of torques acting at the shoulder. The mechanisms underlying this link remain unclear. The purpose of this study was to evaluate whether the effects of shoulder loading on elbow function were related to weakness or its distribution in the paretic limb. Ten subjects with longstanding hemiparesis performed movements with the arm either passively supported against gravity by an air bearing, or by activation of shoulder muscles. Isometric maximum voluntary torques at the elbow and shoulder were measured using a load cell. The speed and range of elbow extension movements were negatively impacted by actively supporting the paretic limb against gravity. However, the effects of gravity loading were not related to proximal weakness or abnormalities in the elbow flexor-extensor strength balance. The findings support the existence of abnormal descending motor commands that constrain the ability of stroke survivors to generate elbow extension torque in combination with abduction torque at the shoulder.

The social context of occupational disease: asbestos and South Africa.

PubMed

Myers, J

1981-01-01

General issues of industrial health are raised in relation to the production of asbestos and asbestos-related diseases in South Africa., A historical analysis of these diseases and their control in Britain demonstrates some general problems of occupational diseases with long incubation periods and their implications for capital and labor. In order to understand the role of the research establishment, an attempt is made to situate the state in the conflict between capital and labor. The terms and weapons of this ideological arena are investigated. The South African situation is then discussed. Its evident weaknesses--the lack of statutory limits on exposure, capital's responsibility for monitoring exposure and health, the inefficiency of the state inspection, and the meagerness and racial disparities in compensation--are related to the weakness of organized labor. These weaknesses are linked to the movement of certain industrial processes, finally acknowledged as unsafe by most academic research, away from the developed countries. In these countries, the strength of labor and environmental organizations has caused a decline in capitalist productivity.

Fixed point theorems for generalized α -β-weakly contraction mappings in metric spaces and applications.

PubMed

Latif, Abdul; Mongkolkeha, Chirasak; Sintunavarat, Wutiphol

2014-01-01

We extend the notion of generalized weakly contraction mappings due to Choudhury et al. (2011) to generalized α-β-weakly contraction mappings. We show with examples that our new class of mappings is a real generalization of several known classes of mappings. We also establish fixed point results for such mappings in metric spaces. Applying our new results, we obtain fixed point results on ordinary metric spaces, metric spaces endowed with an arbitrary binary relation, and metric spaces endowed with graph.

Weakly stationary noise filtering of satellite-acquired imagery

NASA Technical Reports Server (NTRS)

Palgen, J. J. O.; Tamches, I.; Deutsch, E. S.

1971-01-01

A type of weakly stationary noise called herringbone noise was observed in satellite imagery. The characteristics of this noise are described; a model for its simulation was developed. The model is used to degrade pictorial data for comparison with similar noise degraded Nimbus data. Two filtering methods are defined and evaluated. A user's application demonstration is discussed.

Semiclassical description of hyperfine interaction in calculating chemically induced dynamic nuclear polarization in weak magnetic fields

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

Purtov, P.A.; Salikhov, K.M.

1987-09-01

Semiclassical HFI description is applicable to calculating the integral CIDNP effect in weak fields. The HFI has been calculated for radicals with sufficiently numerous magnetically equivalent nuclei (n greater than or equal to 5) in satisfactory agreement with CIDNP calculations based on quantum-mechanical description of radical-pair spin dynamics.

The drift force on an object in an inviscid weakly-varying rotational flow

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

Wallis, G.B.

The force on any stationary object in an inviscid incompressible extensive steady flow is derived in terms of the added mass tensor and gradient of velocity of the undisturbed fluid. Taylor`s theorem is extended to flows with weak vorticity. There are possible applications to constitutive equations for two-phase flow.

2-[(E)-(1,10-Phenanthrolin-5-yl)imino­meth­yl]phenol methanol monosolvate

PubMed Central

Öztürk Yíldírím, Sema; Demirhan, Nebahat; Elmalí, Fikriye; Butcher, Ray J.

2012-01-01

In the title multi-donor Schiff base compound, C19H13N3O·CH3OH, the dihedral angle between the mean planes of the phenanthroline and phenol rings is 59.3 (1)°. The Schiff base mol­ecule is linked to the solvent mol­ecule by an O—H⋯O hydrogen bond. In the crystal, the components are linked by O—H⋯N hydrogen bonds, weak O—H⋯N inter­actions and π–π stacking inter­actions [centroid–centroid distances = 3.701 (1) and 3.656 (1) Å]. PMID:22606116

5-Amino-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde hemihydrate: a polarized electronic structure within hydrogen-bonded sheets of R(10)(8)(34) rings.

PubMed

Quiroga, Jairo; Trilleras, Jorge; Cobo, Justo; Glidewell, Christopher

2010-01-01

In the title compound, C(11)H(11)N(3)O.0.5H(2)O, the water molecule lies across a twofold rotation axis in the space group Pbcn. The bond distances in the organic component provide evidence for polarization of the electronic structure. The molecular components are linked into puckered sheets of R(10)(8)(34) rings by a combination of O-H...N and N-H...O hydrogen bonds; adjacent sheets are weakly linked by an aromatic pi-pi stacking interaction. Comparisons are made with some fused-ring analogues.

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

Song, Tieling; Zhou, D.L., E-mail: zhoudl72@iphy.ac.cn

We study a hysteresis phenomenon in a rotating BEC with a weak link in a quasi-one-dimensional torus by proposing a microscopic theoretical model including a dissipation bath. By analyzing the role of dissipation and the decay rates of all the energy levels, we are able to give a microscopic interpretation of hysteresis recently observed in the experiment and confirm that the hysteresis is the result of the presence of metastable state. In particular, we obtain the hysteresis loops in a quench process just as that in the experiment. We also find that the shape and size of the hysteresis loopmore » change drastically with the strength of the link.« less

Towards a Numerical Description of Volcano Aeroacoustic Source Processes using Lattice Boltzmann Strategies

NASA Astrophysics Data System (ADS)

Brogi, F.; Malaspinas, O.; Bonadonna, C.; Chopard, B.; Ripepe, M.

2015-12-01

Low frequency (< 20Hz) acoustic measurements have a great potential for the real time characterization of volcanic plume source parameters. Using the classical source theory, acoustic data can be related to the exit velocity of the volcanic jet and to mass eruption rate, based on the geometric constrain of the vent and the mixture density. However, the application of the classical acoustic source models to volcanic explosive eruptions has shown to be challenging and a better knowledge of the link between the acoustic radiation and actual volcanic fluid dynamics processes is required. New insights into this subject could be given by the study of realistic aeroacoustic numerical simulations of a volcanic jet. Lattice Boltzmann strategies (LBS) provide the opportunity to develop an accurate, computationally fast, 3D physical model for a volcanic jet. In the field of aeroacoustic applications, dedicated LBS has been proven to have the low dissipative properties needed for capturing the weak acoustic pressure fluctuations. However, due to the big disparity in magnitude between the flow and the acoustic disturbances, even weak spurious noise sources in simulations can ruin the accuracy of the acoustic predictions. Reflected waves from artificial boundaries defined around the flow region can have significant influence on the flow field and overwhelm the acoustic field of interest. In addition, for highly multiscale turbulent flows, such as volcanic plumes, the number of grid points needed to represent the smallest scales might become intractable and the most complicated physics happen only in small portions of the computational domain. The implementation of the grid refinement, in our model allow us to insert local finer grids only where is actually needed and to increase the size of the computational domain for running more realistic simulations. 3D LBS model simulations for turbulent jet aeroacoustics have been accurately validated. Both mean flow and acoustic results are in good agreement with theory and experimental data available in the literature.

[Implementation of a residency program in anesthesiology in the Northeast of Brazil: impact on work processes and professional motivation].

PubMed

Fernandes, Cláudia Regina; Sousa, Rafael Queiroz de; Arcanjo, Francisco Sávio Alves; Neto, Gerardo Cristino de Menezes; Gomes, Josenília Maria Alves; Giaxa, Renata Rocha Barreto

2015-01-01

Understand, through the theory of social representations, the influence exerted by the establishment a residency program in anesthesiology on anesthetic care and professional motivation in a tertiary teaching hospital in the Northeast of Brazil. Qualitative methodology. The theoretical framework comprised the phenomenology and the Social Representation Theory. Five multidisciplinary focus groups were formed with 17 health professionals (five surgeons, five anesthesiologists, two nurses, and five nursing technicians), who work in operating rooms and post-anesthesia care units, all with prior and posterior experience to the establishment of residency. From the response content analysis, the following empirical categories emerged: motivation to upgrade, recycling of anesthesiologists and improving anesthetic practice, resident as an interdisciplinary link in perioperative care, improvements in the quality of perioperative care, recognition of weaknesses in the perioperative process. It was evident upper gastrointestinal bleeding secondary to prolonged intubation that the creation of a residency in anesthesiology brings advancements that are reflected in the motivation of anesthesiologists; the resident worked as an interdisciplinary link between the multidisciplinary team; there was recognition of weaknesses in the system, which were identified and actions to overcome it were proposed. The implementation of a residency program in anesthesiology at a tertiary education hospital in the Northeast of Brazil promoted scientific updates, improved the quality of care and processes of interdisciplinary care, recognized the weaknesses of the service, developed action plans and suggested that this type of initiative may be useful in remote areas of developing countries. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Holocene East Asian Monsoon Variability: Links to Solar and Tropical Pacific Forcing

NASA Astrophysics Data System (ADS)

Kandasamy, S.; Chen, C. A.; Lou, J.

2006-12-01

Sedimentary geochemical records from subalpine Retreat Lake, subtropical Taiwan, document the unstable East Asian Monsoon (EAM) climate for the last ~10250 calendar years before the present (cal yr B.P.). The proxy records demonstrate cool, glacial conditions with weak EAM between ~10250 and 8640 cal yr B.P., the strongest EAM during the "Holocene optimum" (8640-4500 cal yr B.P.) with an abrupt, decadal onset of postglacial EAM (8640-8600 cal yr B.P.), and relatively dry conditions since 4500 cal yr B.P. Although after 8600 cal yr B.P., EAM strength reduces gradually in response to the Northern Hemisphere summer insolation, heat and moisture transport and the development of late Holocene El-Niño-Southern Oscillation in the tropical Pacific appear to corroborate the periods of abrupt monsoon changes. Our proxy records reveal several weak monsoon intervals that correlate to low sea surface temperatures in the western tropical Pacific and cold events in the North Atlantic, suggesting a mechanistic link. Among those, four weak EAM events at 8170, 5400, 4500-2100 and 2000-1600 cal yr B.P. are in phase with the timings of low concentrations of atmospheric methane and periods of reduced North Atlantic Deep Water production as well as the `8.2 ka cold spell' and widespread event of low-latitude cultural collapse. Our EAM records exhibit strong correlations with high- and low-latitude climate and monsoon records; thus, provide robust evidences that the centennial-millennial scale monsoon variability during the Holocene are globally-mediated via sun- ocean-monsoon-North Atlantic linkages.

Dopamine and the Creative Mind: Individual Differences in Creativity Are Predicted by Interactions between Dopamine Genes DAT and COMT.

PubMed

Zabelina, Darya L; Colzato, Lorenza; Beeman, Mark; Hommel, Bernhard

2016-01-01

The dopaminergic (DA) system may be involved in creativity, however results of past studies are mixed. We attempted to clarify this putative relation by considering the mediofrontal and the nigrostriatal DA pathways, uniquely and in combination, and their contribution to two different measures of creativity--an abbreviated version of the Torrance Test of Creative Thinking, assessing divergent thinking, and a real-world creative achievement index. We found that creativity can be predicted from interactions between genetic polymorphisms related to frontal (COMT) and striatal (DAT) DA pathways. Importantly, the Torrance test and the real-world creative achievement index related to different genetic patterns, suggesting that these two measures tap into different aspects of creativity, and depend on distinct, but interacting, DA sub-systems. Specifically, we report that successful performance on the Torrance test is linked with dopaminergic polymorphisms associated with good cognitive flexibility and medium top-down control, or with weak cognitive flexibility and strong top-down control. The latter is particularly true for the originality factor of divergent thinking. High real-world creative achievement, on the other hand, as assessed by the Creative Achievement Questionnaire, is linked with dopaminergic polymorphisms associated with weak cognitive flexibility and weak top-down control. Taken altogether, our findings support the idea that human creativity relies on dopamine, and on the interaction between frontal and striatal dopaminergic pathways in particular. This interaction may help clarify some apparent inconsistencies in the prior literature, especially if the genes and/or creativity measures were analyzed separately.

Dopamine and the Creative Mind: Individual Differences in Creativity Are Predicted by Interactions between Dopamine Genes DAT and COMT

PubMed Central

Zabelina, Darya L.; Colzato, Lorenza; Beeman, Mark; Hommel, Bernhard

2016-01-01

The dopaminergic (DA) system may be involved in creativity, however results of past studies are mixed. We attempted to clarify this putative relation by considering the mediofrontal and the nigrostriatal DA pathways, uniquely and in combination, and their contribution to two different measures of creativity–an abbreviated version of the Torrance Test of Creative Thinking, assessing divergent thinking, and a real-world creative achievement index. We found that creativity can be predicted from interactions between genetic polymorphisms related to frontal (COMT) and striatal (DAT) DA pathways. Importantly, the Torrance test and the real-world creative achievement index related to different genetic patterns, suggesting that these two measures tap into different aspects of creativity, and depend on distinct, but interacting, DA sub-systems. Specifically, we report that successful performance on the Torrance test is linked with dopaminergic polymorphisms associated with good cognitive flexibility and medium top-down control, or with weak cognitive flexibility and strong top-down control. The latter is particularly true for the originality factor of divergent thinking. High real-world creative achievement, on the other hand, as assessed by the Creative Achievement Questionnaire, is linked with dopaminergic polymorphisms associated with weak cognitive flexibility and weak top-down control. Taken altogether, our findings support the idea that human creativity relies on dopamine, and on the interaction between frontal and striatal dopaminergic pathways in particular. This interaction may help clarify some apparent inconsistencies in the prior literature, especially if the genes and/or creativity measures were analyzed separately. PMID:26783754

Quantum discord with weak measurement operators of quasi-Werner states based on bipartite entangled coherent states

NASA Astrophysics Data System (ADS)

Castro, E.; Gómez, R.; Ladera, C. L.; Zambrano, A.

2013-11-01

Among many applications quantum weak measurements have been shown to be important in exploring fundamental physics issues, such as the experimental violation of the Heisenberg uncertainty relation and the Hardy paradox, and have also technological implications in quantum optics, quantum metrology and quantum communications, where the precision of the measurement is as important as the precision of quantum state preparation. The theory of weak measurement can be formulated using the pre-and post-selected quantum systems, as well as using the weak measurement operator formalism. In this work, we study the quantum discord (QD) of quasi-Werner mixed states based on bipartite entangled coherent states using the weak measurements operator, instead of the projective measurement operators. We then compare the quantum discord for both kinds of measurement operators, in terms of the entanglement quality, the latter being measured using the concept of concurrence. It's found greater quantum correlations using the weak measurement operators.

Weak values in continuous weak measurements of qubits

NASA Astrophysics Data System (ADS)

Qin, Lupei; Liang, Pengfei; Li, Xin-Qi

2015-07-01

For continuous weak measurements of qubits, we obtain exact expressions for weak values (WVs) from the postselection restricted average of measurement outputs, by using both the quantum-trajectory equation (QTE) and the quantum Bayesian approach. The former is applicable to short-time weak measurement, while the latter can relax the measurement strength to finite. We find that even in the "very" weak limit the result can be essentially different from the one originally proposed by Aharonov, Albert, and Vaidman (AAV), in the sense that our result incorporates nonperturbative correction which could be important when the AAV WV is large. Within the Bayesian framework, we obtain also elegant expressions for finite measurement strength and find that the amplifier's noise in quantum measurement has no effect on the WVs. In particular, we obtain very useful results for homodyne measurement in a circuit-QED system, which allows for measuring the real and imaginary parts of the AAV WV by simply tuning the phase of the local oscillator. This advantage can be exploited as an efficient state-tomography technique.

EEE Links, Volume 9, No. 1, January 2003 Focus on Plastic Parts

NASA Technical Reports Server (NTRS)

2003-01-01

The January 2003 issue of Electronic, Electromechanical, Electric (EEE) Links is presented. The Programmable Logic Application Notes column has been reinstated in this newsletter. Written by Rich Katz of NASA's Office of Logic Design (OLD), the application notes offer technical tips intended to prevent flight design errors and enhance research, development, and use of programmable logic and elements for space flight applications. An archive of these notes columns from previous issues of EEE Links is available at http://www.klabs.org/richcontent/eeelink s/EEE Links.htm.

Theater Logistics Management: A Case for a Joint Distribution Solution

DTIC Science & Technology

2008-03-15

Multinational (JIIM) operations necessitate creating joint-multinational-based distribution management centers which effectively manage materiel...in the world. However, as the operation continued, the inherent weakness of the intra-theater logistical distribution management link became clear...compounded the distribution management problem. The common thread between each of the noted GAO failures is the lack of a defined joint, theater

Enhancing Links between Research and Practice to Improve Consumer Financial Education and Well-Being

ERIC Educational Resources Information Center

Hensley, Billy J.

2015-01-01

A recent meta-analysis of the effect of financial literacy and financial education on downstream financial behaviors has shown a weak collective impact of the work of financial education. While the findings are not stellar, they do not support a dismantling of financial education programs and funding. This paper examines the findings of the…

Evaluating the Impact of Teacher Professional Development: An Evidence-Based Framework

ERIC Educational Resources Information Center

King, Fiona

2014-01-01

Does teacher professional development make a difference? How do we know? While researchers and policy-makers acknowledge that teacher professional development (PD) needs to be assessed and evaluated, there is often little clarity as to how this can be achieved. Evaluation of teacher PD by schools has been described as the weak link in the PD chain…

Bernoulli potential in type-I and weak type-II superconductors: II. Surface dipole

NASA Astrophysics Data System (ADS)

Lipavský, P.; Morawetz, K.; Koláček, J.; Mareš, J. J.; Brandt, E. H.; Schreiber, M.

2004-09-01

The Budd-Vannimenus theorem is modified to apply to superconductors in the Meissner state. The obtained identity links the surface value of the electrostatic potential to the density of free energy at the surface which allows one to evaluate the electrostatic potential observed via the capacitive pickup without the explicit solution of the charge profile.

Is Social Categorization the Missing Link between Weak Central Coherence and Mental State Inference Abilities in Autism? Preliminary Evidence from a General Population Sample

ERIC Educational Resources Information Center

Skorich, Daniel P.; May, Adrienne R.; Talipski, Louisa A.; Hall, Marnie H.; Dolstra, Anita J.; Gash, Tahlia B.; Gunningham, Beth H.

2016-01-01

We explore the relationship between the "theory of mind" (ToM) and "central coherence" difficulties of autism. We introduce covariation between hierarchically-embedded categories and social information--at the local level, the global level, or at both levels simultaneously--within a category confusion task. We then ask…

Effect of microwave-enhanced superconductivity in YBa{sub 2}Cu{sub 3}O{sub 7} bi-crystalline grain boundary weak-links

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

Fu, C.M.; Chen, C.M.; Lin, H.C.

1994-12-31

We have studied systematically the effect of microwave irradiation on the temperature dependent resistivity R(T) and the current-voltage (I-V) characteristics of YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) bicrystalline grain boundary weak-links (GBWLs), with grain boundary of three different tilt angles. The superconducting transition temperature, T{sub c}, has significant enhancement upon microwave irradiation. The microwave enhanced T{sub c} is increased as a function of incidence microwave power, but limited to an optimum power level. The GBWLs of 45{degrees} tilt boundary has shown to be most sensitive to the microwave irradiation power, and the GBWLs of 36.8{degrees} tilt boundary has displayed a moderatemore » response. In contrast, no enhancement of T{sub c} was observed in the GBWLs of 24{degrees} tilt boundary, as well as in the uniform films. Under the microwave irradiation, the R(T) dependence is hysteretic as the transition taken from superconducting state to normal state and vice versa. Mechanisms associated with the redistribution of nonequilibrium quasiparticles under microwave irradiation are discussed.« less

Three-Dimensional Characterization and Modeling of Microstructural Weak Links for Spall Damage in FCC Metals

DOE PAGES

Krishnan, Kapil; Brown, Andrew; Wayne, Leda; ...

2014-11-25

Local microstructural weak links for spall damage were investigated using three-dimensional (3-D) characterization in multicrystalline copper samples (grain size ≈ 450 µm) shocked with laser-driven plates at low pressures (2 to 4 GPa). The thickness of samples and flyer plates, approximately 1000 and 500 µm respectively, led to short pressure pulses that allowed isolating microstructure effects on local damage characteristics. Electron Backscattering Diffraction and optical microscopy were used to relate the presence, size, and shape of porosity to local microstructure. The experiments were complemented with 3-D finite element simulations of individual grain boundaries (GBs) that resulted in large damage volumesmore » using crystal plasticity coupled with a void nucleation and growth model. Results from analysis of these damage sites show that the presence of a GB-affected zone, where strain concentration occurs next to a GB, correlates strongly with damage localization at these sites, most likely due to the inability of maintaining strain compatibility across these interfaces, with additional effects due to the inclination of the GB with respect to the shock. Results indicate that strain compatibility plays an important role on intergranular spall damage in metallic materials.« less

The Bi-Modal Pattern of the Summer Circulation Over South America

NASA Technical Reports Server (NTRS)

Herdies, Dirceu Luis; daSilva, Arlindo; SilvaDias, Maria A. F.; Atlas, Robert (Technical Monitor)

2001-01-01

Submonthly variations in warm-season (January-February) precipitation over South America, in special over the Amazon basin, central southwest Brazil, north Argentina, and Paraguay are shown to be strongly linked to variations in the moisture entering the continent from the Atlantic ocean. Two distinct regimes of lower tropospheric winds (westerlies and easterlies) were observed in Rondonia during the Wet Season Atmospheric Mesoscale Campaign (WETAMC) component of the Large Scale Atmosphere-Biosphere Experiment in Amazonia (LBA) and the Tropical Rainfall Measuring Mission (TRMM) field campaign. The westerly (easterly) winds were associated with the strong (weak) convective activity over the South Atlantic Convergence Zone (SACZ). The whole period of this study (January-February) was divided into SACZ and NSACZ (No SACZ) events. The vertically integrated moisture fluxes over the Amazon and Prata basin from the National Aeronautics and Space Administration/Goddard Data Assimilation Office (NASA/DAO) assimilation show that during SACZ (NSACZ) event strong (weak) convergence occurred over the Amazon basin with divergence (convergence) over the Prata basin. Submonthly variations in the SACZ also can be linked to extreme climate anomalies such as droughts or flooding conditions over the Amazon and Prata basin.

A critical assessment of the ecological assumptions underpinning compensatory mitigation of salmon-derived nutrients

USGS Publications Warehouse

Collins, Scott F.; Marcarelli, Amy M.; Baxter, Colden V.; Wipfli, Mark S.

2015-01-01

We critically evaluate some of the key ecological assumptions underpinning the use of nutrient replacement as a means of recovering salmon populations and a range of other organisms thought to be linked to productive salmon runs. These assumptions include: (1) nutrient mitigation mimics the ecological roles of salmon, (2) mitigation is needed to replace salmon-derived nutrients and stimulate primary and invertebrate production in streams, and (3) food resources in rearing habitats limit populations of salmon and resident fishes. First, we call into question assumption one because an array of evidence points to the multi-faceted role played by spawning salmon, including disturbance via redd-building, nutrient recycling by live fish, and consumption by terrestrial consumers. Second, we show that assumption two may require qualification based upon a more complete understanding of nutrient cycling and productivity in streams. Third, we evaluate the empirical evidence supporting food limitation of fish populations and conclude it has been only weakly tested. On the basis of this assessment, we urge caution in the application of nutrient mitigation as a management tool. Although applications of nutrients and other materials intended to mitigate for lost or diminished runs of Pacific salmon may trigger ecological responses within treated ecosystems, contributions of these activities toward actual mitigation may be limited.

Synthesis and enzymatic degradation of epichlorohydrin cross-linked pectins.

PubMed

Semdé, Rasmané; Moës, André J; Devleeschouwer, Michel J; Amighi, Karim

2003-02-01

The water solubility of pectin was successfully decreased by cross-linking with increasing amounts of epichlorohydrin in the reaction media. The initial molar ratios of epichlorohydrin/ galacturonic acid monomer in the reaction mixtures were 0, 0.37, 0.56, 0.74, 1.00, 1.47, and 2.44. The resulting epichlorohydrin cross-linked pectins were thus referred to as C-LP0, C-LP37, C-LP56, C-LP75, C-LP100, C-LP150, and C-LP250, respectively. Methoxylation degrees ranged from 60.5 +/- 0.9% to 68.0 +/- 0.6%, and the effective cross-linking degrees, determined by quantification of the hydroxyl anions consumed during the reaction, were 0, 17.8, 26.0, 38.3, 46.5, 53.5, and 58.7%. respectively. After incubating the different cross-linked pectins (0.5% w/v) in 25 mL of 0.05 M acetate-phosphate buffer (pH 4.5), containing 50 microL of Pectinex Ultra SP-L (pectinolytic enzymes), between 60 and 80% of the pectin osidic bounds were broken in less than 1 hr. Moreover, increasing the cross-linking degree only resulted in a weak slowing on the enzymatic degradation velocity.

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

Wilbur, Jeffrey D.; Gomez, Enrique D.; Ellsworth, Mark W.

A procedure for creating samples that can be repeatedly cycled between weakly aligned and strongly aligned states is described. Poly(styrene-b-isoprene) block copolymer samples were first shear-aligned and then cross-linked using a high energy electron beam. Samples with more than 1.0 cross-links per chain on average showed almost complete recovery of their initial alignment state even after 20 cycles of heating above the order–disorder transition temperature of the un-cross-linked block copolymer. Samples with 1.1 cross-links per chain, which showed over 90% loss of alignment on heating and almost 100% recovery of alignment on cooling, provided the best example of a reversiblemore » aligned-to-unaligned transition. Samples with lower cross-linking densities exhibited irreversible loss of alignment upon heating, while those with higher cross-linking densities exhibited less than 90% loss of alignment upon heating. Alignment was quantified by a technique that we call two color depolarized light scattering (TCDLS), an extension of the traditional depolarized light scattering experiment used to determine the state of order in block copolymers. Qualitative confirmation of our interpretation of TCDLS data was obtained by small-angle X-ray scattering and transmission electron microscopy.« less

From link-prediction in brain connectomes and protein interactomes to the local-community-paradigm in complex networks

PubMed Central

Cannistraci, Carlo Vittorio; Alanis-Lobato, Gregorio; Ravasi, Timothy

2013-01-01

Growth and remodelling impact the network topology of complex systems, yet a general theory explaining how new links arise between existing nodes has been lacking, and little is known about the topological properties that facilitate link-prediction. Here we investigate the extent to which the connectivity evolution of a network might be predicted by mere topological features. We show how a link/community-based strategy triggers substantial prediction improvements because it accounts for the singular topology of several real networks organised in multiple local communities - a tendency here named local-community-paradigm (LCP). We observe that LCP networks are mainly formed by weak interactions and characterise heterogeneous and dynamic systems that use self-organisation as a major adaptation strategy. These systems seem designed for global delivery of information and processing via multiple local modules. Conversely, non-LCP networks have steady architectures formed by strong interactions, and seem designed for systems in which information/energy storage is crucial. PMID:23563395

Pulse-coupled neural nets: translation, rotation, scale, distortion, and intensity signal invariance for images.

PubMed

Johnson, J L

1994-09-10

The linking-field neural network model of Eckhorn et al. [Neural Comput. 2, 293-307 (1990)] was introduced to explain the experimentally observed synchronous activity among neural assemblies in the cat cortex induced by feature-dependent visual activity. The model produces synchronous bursts of pulses from neurons with similar activity, effectively grouping them by phase and pulse frequency. It gives a basic new function: grouping by similarity. The synchronous bursts are obtained in the limit of strong linking strengths. The linking-field model in the limit of moderate-to-weak linking characterized by few if any multiple bursts is investigated. In this limit dynamic, locally periodic traveling waves exist whose time signal encodes the geometrical structure of a two-dimensional input image. The signal can be made insensitive to translation, scale, rotation, distortion, and intensity. The waves transmit information beyond the physical interconnect distance. The model is implemented in an optical hybrid demonstration system. Results of the simulations and the optical system are presented.

Ion exchange selectivity for cross-linked polyacrylic acid

NASA Technical Reports Server (NTRS)

May, C. E.; Philipp, W. H.

1983-01-01

The ion separation factors for 21 common metal ions with cross-linked polyacrylic acid were determined as a function of pH and the percent of the cross-linked polyacrylic acid neutralized. The calcium ion was used as a reference. At a pH of 5 the decreasing order of affinity of the ions for the cross-linked polyacrylic acid was found to be: Hg++, Fe+++, Pb++, Cr+++, Cu++, Cd++, Al+++, Ag+, Zn++, Ni++, Mn++, Co++, Ca++, Sr++, Ba++, Mg++, K+, Rb+, Cs+, Na+, and Li+. Members of a chemical family exhibited similar selectivities. The Hg++ ion appeared to be about a million times more strongly bound than the alkali metal ions. The relative binding of most of the metal ions varied with pH; the very tightly and very weakly bound ions showed the largest variations with pH. The calcium ion-hydrogen ion equilibrium was perturbed very little by the presence of the other ions. The separation factors and selectivity coefficients are discussed in terms of equilibrium and thermodynamic significance.

From link-prediction in brain connectomes and protein interactomes to the local-community-paradigm in complex networks.

PubMed

Cannistraci, Carlo Vittorio; Alanis-Lobato, Gregorio; Ravasi, Timothy

2013-01-01

Growth and remodelling impact the network topology of complex systems, yet a general theory explaining how new links arise between existing nodes has been lacking, and little is known about the topological properties that facilitate link-prediction. Here we investigate the extent to which the connectivity evolution of a network might be predicted by mere topological features. We show how a link/community-based strategy triggers substantial prediction improvements because it accounts for the singular topology of several real networks organised in multiple local communities - a tendency here named local-community-paradigm (LCP). We observe that LCP networks are mainly formed by weak interactions and characterise heterogeneous and dynamic systems that use self-organisation as a major adaptation strategy. These systems seem designed for global delivery of information and processing via multiple local modules. Conversely, non-LCP networks have steady architectures formed by strong interactions, and seem designed for systems in which information/energy storage is crucial.

X-ray microscopy with high-resolution zone plates: recent developments

NASA Astrophysics Data System (ADS)

Schneider, Gerd; Wilhein, Thomas; Niemann, Bastian; Guttman, P.; Schliebe, T.; Lehr, J.; Aschoff, H.; Thieme, Juergen; Rudolph, Dietbert M.; Schmahl, Guenther A.

1995-09-01

In order to expand the applications of x-ray microscopy, developments in the fields of zone plate technology, specimen preparation and imaging techniques have been made. A new cross- linked polymer chain electron beam resist allows us to record zone plate pattern down to 19 nm outermost zone width. High resolution zone plates in germanium with outermost zone widths down to 19 nm have been developed. In addition, phase zone plates in nickel down to 30 nm zone width have been made by electroplating. In order to enhance the image contrast for weak absorbing objects, the phase contrast method for x-ray microscopy was developed and implemented on the Gottingen x-ray microscope at BESSY. The effects of x ray absorption on the structure of biological specimen limits the maximum applicable radiation dose and therefore the achievable signal to noise ratio for an artifact-free x-ray image. To improve the stability especially of biological specimen, a cryogenic object chamber has been developed and tested. It turns out that at the operating temperature T less than or equal to 130 K unfixed biological specimen can be exposed to a radiation dose of 109 - 1010 Gy without any observable structural changes. A multiple-angle viewing stage allows us to take stereoscopic images with the x-ray microscope, giving a 3D-impression of the object. As an example for the applications of x-ray microscopy in biology, erythrocytes infected by malaria parasite have been examined. Studies of the aggregation of hematite by sodium sulfate gives an example for the application of x-ray microscopy in the field of colloid research.

C-class functions with new approach on coincidence point results for generalized [Formula: see text]-weakly contractions in ordered b-metric spaces.

PubMed

Mustafa, Zead; Jaradat, Mohammed M M; Ansari, Arslan Hojat; Popović, Branislav Z; Jaradat, Husein M

2016-01-01

In this paper, by using the C-class functions and a new approach we present some coincidence point results for four mappings satisfying generalized [Formula: see text]-weakly contractive condition in the setting of ordered b-metric spaces. Also, an application and example are given to support our results.

New Developments in Error Detection and Correction Strategies for Critical Applications

NASA Technical Reports Server (NTRS)

Berg, Melanie; LaBel, Ken

2016-01-01

The presentation will cover a variety of mitigation strategies that were developed for critical applications. An emphasis is placed on strengths and weaknesses per mitigation technique as it pertains to different FPGA device types.

Weak Lie symmetry and extended Lie algebra

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

Goenner, Hubert

2013-04-15

The concept of weak Lie motion (weak Lie symmetry) is introduced. Applications given exhibit a reduction of the usual symmetry, e.g., in the case of the rotation group. In this context, a particular generalization of Lie algebras is found ('extended Lie algebras') which turns out to be an involutive distribution or a simple example for a tangent Lie algebroid. Riemannian and Lorentz metrics can be introduced on such an algebroid through an extended Cartan-Killing form. Transformation groups from non-relativistic mechanics and quantum mechanics lead to such tangent Lie algebroids and to Lorentz geometries constructed on them (1-dimensional gravitational fields).

Atmospheric Quantum Channels with Weak and Strong Turbulence.

PubMed

Vasylyev, D; Semenov, A A; Vogel, W

2016-08-26

The free-space transfer of high-fidelity optical signals between remote locations has many applications, including both classical and quantum communication, precision navigation, clock synchronization, etc. The physical processes that contribute to signal fading and loss need to be carefully analyzed in the theory of light propagation through the atmospheric turbulence. Here we derive the probability distribution for the atmospheric transmittance including beam wandering, beam shape deformation, and beam-broadening effects. Our model, referred to as the elliptic beam approximation, applies to weak, weak-to-moderate, and strong turbulence and hence to the most important regimes in atmospheric communication scenarios.

Weak Hard X-Ray Emission from Two Broad Absorption Line Quasars Observed with NuStar: Compton-Thick Absorption or Intrinsic X-Ray Weakness?

NASA Technical Reports Server (NTRS)

Luo, B.; Brandt, W. N.; Alexander, D. M.; Harrison, F. A.; Stern, D.; Bauer, F. E.; Boggs, S. E.; Christensen, F. E.; Comastri, A.; Craig, W. W..;

WEAK HARD X-RAY EMISSION FROM TWO BROAD ABSORPTION LINE QUASARS OBSERVED WITH NuSTAR: COMPTON-THICK ABSORPTION OR INTRINSIC X-RAY WEAKNESS?

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

Luo, B.; Brandt, W. N.; Alexander, D. M.

We present Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray observations of two X-ray weak broad absorption line (BAL) quasars, PG 1004+130 (radio loud) and PG 1700+518 (radio quiet). Many BAL quasars appear X-ray weak, probably due to absorption by the shielding gas between the nucleus and the accretion-disk wind. The two targets are among the optically brightest BAL quasars, yet they are known to be significantly X-ray weak at rest-frame 2-10 keV (16-120 times fainter than typical quasars). We would expect to obtain Almost-Equal-To 400-600 hard X-ray ({approx}> 10 keV) photons with NuSTAR, provided that these photons are not significantlymore » absorbed (N{sub H} {approx}< 10{sup 24} cm{sup -2}). However, both BAL quasars are only detected in the softer NuSTAR bands (e.g., 4-20 keV) but not in its harder bands (e.g., 20-30 keV), suggesting that either the shielding gas is highly Compton-thick or the two targets are intrinsically X-ray weak. We constrain the column densities for both to be N{sub H} Almost-Equal-To 7 Multiplication-Sign 10{sup 24} cm{sup -2} if the weak hard X-ray emission is caused by obscuration from the shielding gas. We discuss a few possibilities for how PG 1004+130 could have Compton-thick shielding gas without strong Fe K{alpha} line emission; dilution from jet-linked X-ray emission is one likely explanation. We also discuss the intrinsic X-ray weakness scenario based on a coronal-quenching model relevant to the shielding gas and disk wind of BAL quasars. Motivated by our NuSTAR results, we perform a Chandra stacking analysis with the Large Bright Quasar Survey BAL quasar sample and place statistical constraints upon the fraction of intrinsically X-ray weak BAL quasars; this fraction is likely 17%-40%.« less

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

Lu, Z. X.; Tynan, G.; Center for Momentum Transport and Flow Organization and Center for Astrophysics and Space Science, University of California, San Diego, California 92093

Intrinsic torque, which can be generated by turbulent stresses, can induce toroidal rotation in a tokamak plasma at rest without direct momentum injection. Reversals in intrinsic torque have been inferred from the observation of toroidal velocity changes in recent lower hybrid current drive (LHCD) experiments. This work focuses on understanding the cause of LHCD-induced intrinsic torque reversal using gyrokinetic simulations and theoretical analyses. A new mechanism for the intrinsic torque reversal linked to magnetic shear (s{sup ^}) effects on the turbulence spectrum is identified. This reversal is a consequence of the ballooning structure at weak s{sup ^}. Based on realisticmore » profiles from the Alcator C-Mod LHCD experiments, simulations demonstrate that the intrinsic torque reverses for weak s{sup ^} discharges and that the value of s{sup ^}{sub crit} is consistent with the experimental results s{sup ^}{sub crit}{sup exp}≈0.2∼0.3 [Rice et al., Phys. Rev. Lett. 111, 125003 (2013)]. The consideration of this intrinsic torque feature in our work is important for the understanding of rotation profile generation at weak s{sup ^} and its consequent impact on macro-instability stabilization and micro-turbulence reduction, which is crucial for ITER. It is also relevant to internal transport barrier formation at negative or weakly positive s{sup ^}.« less

Characteristics of Social Networks and Mortality Risk: Evidence From 2 Prospective Cohort Studies.

PubMed

Kauppi, Maarit; Kawachi, Ichiro; Batty, George David; Oksanen, Tuula; Elovainio, Marko; Pentti, Jaana; Aalto, Ville; Virtanen, Marianna; Koskenvuo, Markku; Vahtera, Jussi; Kivimäki, Mika

2018-04-01

The size of a person's social network is linked to health and longevity, but it is unclear whether the number of strong social ties or the number of weak social ties is most influential for health. We examined social network characteristics as predictors of mortality in the Finnish Public Sector Study (n = 7,617) and the Health and Social Support Study (n = 20,816). Social network characteristics were surveyed at baseline in 1998. Information about mortality was obtained from the Finnish National Death Registry. During a mean follow-up period of 16 years, participants with a small social network (≤10 members) were more likely to die than those with a large social network (≥21 members) (adjusted hazard ratio (HR) = 1.23, 95% confidence interval (CI): 1.04, 1.46). Mortality risk was increased among participants with both a small number of strong ties (≤2 members) and a small number of weak ties (≤5 members) (HR = 1.55, 95% CI: 1.26, 1.79) and among participants with both a large number of strong ties and a small number of weak ties (HR = 1.28, 95% CI: 1.08, 1.52), but not among those with a small number of strong ties and a large number of weak ties (HR = 1.04, 95% CI: 0.87, 1.25). These findings suggest that in terms of mortality risk, the number of weak ties may be an important component of social networks.

A Review of Collagen Cross-Linking in Cornea and Sclera

PubMed Central

Zhang, Xiao; Tao, Xiang-chen; Zhang, Jian; Li, Zhi-wei; Xu, Yan-yun; Wang, Yu-meng; Zhang, Chun-xiao; Mu, Guo-ying

2015-01-01

Riboflavin/UVA cross-linking is a technique introduced in the past decades for the treatment of keratoconus, keratectasia, and infectious keratitis. Its efficacy and safety have been investigated with clinical and laboratory studies since its first clinical application by Wollensak for the treatment of keratoconus. Although its complications are encountered during clinical practice, such as infection inducing risk, minimal invasion merits a further investigation on its future application in clinical practice. Recently, collagen cross-linking in sclera shows a promising prospect. In present study, we summarized the representative studies describing the clinical and laboratory application of collagen cross-linking published in past decades and provided our opinion on the positive and negative results of cross-linking in the treatment of ophthalmic disorders. PMID:25922758

How "Central" Is Central Coherence?: Preliminary Evidence on the Link between Conceptual and Perceptual Processing in Children with Autism

ERIC Educational Resources Information Center

Lopez, Beatriz; Leekam, Susan R.; Arts, Gerda R. J.

2008-01-01

This study aimed to test the assumption drawn from weak central coherence theory that a central cognitive mechanism is responsible for integrating information at both conceptual and perceptual levels. A visual semantic memory task and a face recognition task measuring use of holistic information were administered to 15 children with autism and 16…

Developing statistical wildlife habitat relationships for assessing cumulative effects of fuels treatments: Final Report for Joint Fire Science Program Project

Treesearch

Samuel A. Cushman; Kevin S. McKelvey

2006-01-01

The primary weakness in our current ability to evaluate future landscapes in terms of wildlife lies in the lack of quantitative models linking wildlife to forest stand conditions, including fuels treatments. This project focuses on 1) developing statistical wildlife habitat relationships models (WHR) utilizing Forest Inventory and Analysis (FIA) and National Vegetation...

The Middle School Mess: If You Love Bungee Jumping, You're the Middle School Type

ERIC Educational Resources Information Center

Meyer, Peter

2011-01-01

Suspended "between childhood and the adult world, pre-teens have been called the toughest to teach." Indeed, one can't touch middle school without hearing about "raging hormones." By all accounts, middle schools are a weak link in the chain of public education. Is it the churn of ill-conceived attempts at reform that's causing all the problems? Is…

Sociological Support for the Job Placement of Students and Graduates of Higher Educational Institutions: The Experience of the Moscow Institute of Aviation and Technology (MATI)

ERIC Educational Resources Information Center

Bolotin, I. S.; Basalai, S. I.; Pugach, V. F.; Mikhailov, A. A.

2013-01-01

The weak connection between Russia's system of higher education and the labor market in Russia requires that greater attention be paid to preparing students for successful, employment. This will require more careful research into best practices, and the development of more effective links between employers and educational institutions.

4-Benzyl-4-ethyl-morpholin-1-ium hexa-fluoro-phosphate.

PubMed

Yang, Fang; Zang, Hongjun; Cheng, Bowen; Xu, Xianlin; Ren, Yuanlin

2012-03-01

The asymmetric unit of the title compound, C(13)H(20)NO(+)·PF(6) (-), contains two cations, one complete anion and two half hexa-fluoro-phosphate anions having crystallographically imposed twofold rotation symmetry. In the cations, the morpholine rings are in a chair conformation. In the crystal, ions are linked by weak C-H⋯F hydrogen bonds into a three-dimensional network.

Joint weak value for all order coupling using continuous variable and qubit probe

NASA Astrophysics Data System (ADS)

Kumari, Asmita; Pan, Alok Kumar; Panigrahi, Prasanta K.

2017-11-01

The notion of weak measurement in quantum mechanics has gained a significant and wide interest in realizing apparently counterintuitive quantum effects. In recent times, several theoretical and experimental works have been reported for demonstrating the joint weak value of two observables where the coupling strength is restricted to the second order. In this paper, we extend such a formulation by providing a complete treatment of joint weak measurement scenario for all-order-coupling for the observable satisfying A 2 = 𝕀 and A 2 = A, which allows us to reveal several hitherto unexplored features. By considering the probe state to be discrete as well as continuous variable, we demonstrate how the joint weak value can be inferred for any given strength of the coupling. A particularly interesting result we pointed out that even if the initial pointer state is uncorrelated, the single pointer displacement can provide the information about the joint weak value, if at least third order of the coupling is taken into account. As an application of our scheme, we provide an all-order-coupling treatment of the well-known Hardy paradox by considering the continuous as well as discrete meter states and show how the negative joint weak probabilities emerge in the quantum paradoxes at the weak coupling limit.

A network approach for researching partnerships in health

PubMed Central

Lewis, Jenny M

2005-01-01

Background The last decade has witnessed a significant move towards new modes of governing that are based on coordination and collaboration. In particular, local level partnerships have been widely introduced around the world. There are few comprehensive approaches for researching the effects of these partnerships. The aim of this paper is to outline a network approach that combines structure and agency based explanations to research partnerships in health. Network research based on two Primary Care Partnerships (PCPs) in Victoria is used to demonstrate the utility of this approach. The paper examines multiple types of ties between people (structure), and the use and value of relationships to partners (agency), using interviews with the people involved in two PCPs – one in metropolitan Melbourne and one in a rural area. Results Network maps of ties based on work, strategic information and policy advice, show that there are many strong connections in both PCPs. Not surprisingly, PCP staff are central and highly connected. Of more interest are the ties that are dependent on these dedicated partnership staff, as they reveal which actors become weakly linked or disconnected without them. Network measures indicate that work ties are the most dispersed and strategic information ties are the most concentrated around fewer people. Divisions of general practice are weakly linked, while local government officials and Department of Human Services (DHS) regional staff appear to play important bridging roles. Finally, the relationships between partners have changed and improved, and most of those interviewed value their new or improved links with partners. Conclusion Improving service coordination and health promotion planning requires engaging people and building strong relationships. Mapping ties is a useful means for assessing the strengths and weaknesses of partnerships, and network analysis indicates concentration and dispersion, the importance of particular individuals, and the points at which they will fragment. A narrative approach adds an assessment of whether the partnerships are being used and valued. The approach outlined here, which examines structure and agency as separate but related explanations, has much to offer in examining partnerships. PMID:16209718

Probabilistic surface reconstruction from multiple data sets: An example for the Australian Moho

NASA Astrophysics Data System (ADS)

Bodin, T.; Salmon, M.; Kennett, B. L. N.; Sambridge, M.

2012-10-01

Interpolation of spatial data is a widely used technique across the Earth sciences. For example, the thickness of the crust can be estimated by different active and passive seismic source surveys, and seismologists reconstruct the topography of the Moho by interpolating these different estimates. Although much research has been done on improving the quantity and quality of observations, the interpolation algorithms utilized often remain standard linear regression schemes, with three main weaknesses: (1) the level of structure in the surface, or smoothness, has to be predefined by the user; (2) different classes of measurements with varying and often poorly constrained uncertainties are used together, and hence it is difficult to give appropriate weight to different data types with standard algorithms; (3) there is typically no simple way to propagate uncertainties in the data to uncertainty in the estimated surface. Hence the situation can be expressed by Mackenzie (2004): "We use fantastic telescopes, the best physical models, and the best computers. The weak link in this chain is interpreting our data using 100 year old mathematics". Here we use recent developments made in Bayesian statistics and apply them to the problem of surface reconstruction. We show how the reversible jump Markov chain Monte Carlo (rj-McMC) algorithm can be used to let the degree of structure in the surface be directly determined by the data. The solution is described in probabilistic terms, allowing uncertainties to be fully accounted for. The method is illustrated with an application to Moho depth reconstruction in Australia.

Application of a fast sorting algorithm to the assignment of mass spectrometric cross-linking data.

PubMed

Petrotchenko, Evgeniy V; Borchers, Christoph H

2014-09-01

Cross-linking combined with MS involves enzymatic digestion of cross-linked proteins and identifying cross-linked peptides. Assignment of cross-linked peptide masses requires a search of all possible binary combinations of peptides from the cross-linked proteins' sequences, which becomes impractical with increasing complexity of the protein system and/or if digestion enzyme specificity is relaxed. Here, we describe the application of a fast sorting algorithm to search large sequence databases for cross-linked peptide assignments based on mass. This same algorithm has been used previously for assigning disulfide-bridged peptides (Choi et al., ), but has not previously been applied to cross-linking studies. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Compatibility between weak gel and microorganisms in weak gel-assisted microbial enhanced oil recovery.

PubMed

Qi, Yi-Bin; Zheng, Cheng-Gang; Lv, Cheng-Yuan; Lun, Zeng-Min; Ma, Tao

2018-03-20

To investigate weak gel-assisted microbial flooding in Block Wang Long Zhuang in the Jiangsu Oilfield, the compatibility of weak gel and microbe was evaluated using laboratory experiments. Bacillus sp. W5 was isolated from the formation water in Block Wang Long Zhuang. The rate of oil degradation reached 178 mg/day, and the rate of viscosity reduction reached 75.3%. Strain W5 could produce lipopeptide with a yield of 1254 mg/L. Emulsified crude oil was dispersed in the microbial degradation system, and the average diameter of the emulsified oil particles was 18.54 μm. Bacillus sp. W5 did not affect the rheological properties of the weak gel, and the presence of the weak gel did not significantly affect bacterial reproduction (as indicated by an unchanged microbial biomass), emulsification (surface tension is 35.56 mN/m and average oil particles size is 21.38 μm), oil degradation (162 mg/day) and oil viscosity reduction (72.7%). Core-flooding experiments indicated oil recovery of 23.6% when both weak gel and Bacillus sp. W5 were injected into the system, 14.76% when only the weak gel was injected, and 9.78% with strain W5 was injected without the weak gel. The results demonstrate good compatibility between strains W5 and the weak gel and highlight the application potential of weak gel-assisted microbial flooding. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Department of Defense Office of the Inspector General FY 2013 Audit Plan

DTIC Science & Technology

2012-11-01

oversight procedures to review KPMG LLPs work; and if applicable disclose instances where KPMG LLP does not comply, in all material respects, with U.S...decisions. Pervasive material internal control weaknesses impact the accuracy, reliability and timeliness of budgetary and accounting data and...reported the same 13 material internal control weaknesses as in the previous year. These pervasive and longstanding financial management challenges

Enhancing teleportation fidelity by means of weak measurements or reversal

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

Qiu, Liang, E-mail: lqiu@cumt.edu.cn; Tang, Gang; Yang, Xianqing

2014-11-15

The enhancement of teleportation fidelity by weak measurement or quantum measurement reversal is investigated. One qubit of a maximally entangled state undergoes the amplitude damping, and the subsequent application of weak measurement or quantum measurement reversal could improve the teleportation fidelity beyond the classical region. The improvement could not be attributed to the increasing of entanglement, quantum discord, classical correlation or total correlation. We declare that it should be owed to the probabilistic nature of the method. - Highlights: • The method’s probabilistic nature should be responsible for the improvement. • Quantum or classical correlation cannot explain the improvement. •more » The receiver cannot apply weak measurements. • The sender’s quantum measurement reversal is only useful for |Ψ{sup ±}〉.« less

Hypernuclear Weak Decays

NASA Astrophysics Data System (ADS)

Itonaga, K.; Motoba, T.

The recent theoretical studies of Lambda-hypernuclear weak decaysof the nonmesonic and pi-mesonic ones are developed with the aim to disclose the link between the experimental decay observables and the underlying basic weak decay interactions and the weak decay mechanisms. The expressions of the nonmesonic decay rates Gamma_{nm} and the decay asymmetry parameter alpha_1 of protons from the polarized hypernuclei are presented in the shell model framework. We then introduce the meson theoretical Lambda N -> NN interactions which include the one-meson exchanges, the correlated-2pi exchanges, and the chiral-pair-meson exchanges. The features of meson exchange potentials and their roles on the nonmesonic decays are discussed. With the adoption of the pi + 2pi/rho + 2pi/sigma + omega + K + rhopi/a_1 + sigmapi/a_1 exchange potentials, we have carried out the systematic calculations of the nonmesonic decay observables for light-to-heavy hypernuclei. The present model can account for the available experimental data of the decay rates, Gamma_n/Gamma_p ratios, and the intrinsic asymmetry parameters alpha_Lambda (alpha_Lambda is related to alpha_1) of emitted protons well and consistently within the error bars. The hypernuclear lifetimes are evaluated by converting the total weak decay rates Gamma_{tot} = Gamma_pi + Gamma_{nm} to tau, which exhibit saturation property for the hypernuclear mass A ≥ 30 and agree grossly well with experimental data for the mass range from light to heavy hypernuclei except for the very light ones. Future extensions of the model and the remaining problems are also mentioned. The pi-mesonic weak processes are briefly surveyed, and the calculations and predictions are compared and confirmed by the recent high precision FINUDA pi-mesonic decay data. This shows that the theoretical basis seems to be firmly grounded.

Constrained Deep Weak Supervision for Histopathology Image Segmentation.

PubMed

Jia, Zhipeng; Huang, Xingyi; Chang, Eric I-Chao; Xu, Yan

2017-11-01

In this paper, we develop a new weakly supervised learning algorithm to learn to segment cancerous regions in histopathology images. This paper is under a multiple instance learning (MIL) framework with a new formulation, deep weak supervision (DWS); we also propose an effective way to introduce constraints to our neural networks to assist the learning process. The contributions of our algorithm are threefold: 1) we build an end-to-end learning system that segments cancerous regions with fully convolutional networks (FCNs) in which image-to-image weakly-supervised learning is performed; 2) we develop a DWS formulation to exploit multi-scale learning under weak supervision within FCNs; and 3) constraints about positive instances are introduced in our approach to effectively explore additional weakly supervised information that is easy to obtain and enjoy a significant boost to the learning process. The proposed algorithm, abbreviated as DWS-MIL, is easy to implement and can be trained efficiently. Our system demonstrates the state-of-the-art results on large-scale histopathology image data sets and can be applied to various applications in medical imaging beyond histopathology images, such as MRI, CT, and ultrasound images.

Aperture averaging and BER for Gaussian beam in underwater oceanic turbulence

NASA Astrophysics Data System (ADS)

Gökçe, Muhsin Caner; Baykal, Yahya

2018-03-01

In an underwater wireless optical communication (UWOC) link, power fluctuations over finite-sized collecting lens are investigated for a horizontally propagating Gaussian beam wave. The power scintillation index, also known as the irradiance flux variance, for the received irradiance is evaluated in weak oceanic turbulence by using the Rytov method. This lets us further quantify the associated performance indicators, namely, the aperture averaging factor and the average bit-error rate (). The effects on the UWOC link performance of the oceanic turbulence parameters, i.e., the rate of dissipation of kinetic energy per unit mass of fluid, the rate of dissipation of mean-squared temperature, Kolmogorov microscale, the ratio of temperature to salinity contributions to the refractive index spectrum as well as system parameters, i.e., the receiver aperture diameter, Gaussian source size, laser wavelength and the link distance are investigated.

Numerical Study of Wake Vortex Behavior in Turbulent Domains with Ambient Stratification

NASA Technical Reports Server (NTRS)

Switzer, George F.; Proctor, Fred H.

2000-01-01

A three-dimensional large eddy simulation model is used to investigate the sensitivity of ambient stratification with turbulence on the behavior of aircraft wake vortices. Modeled ambient turbulence levels range from very weak to moderate, and stratification levels range from strongly stable to unstable. The results of profound significance from this study are: 1) very little sensitivity between vortex linking time and the level of stratification, 2) the mean vortex separation remained nearly constant regardless of stratification and turbulence (at least prior to linking), 3) the wake vortices did not rise regardless of the level of stratification, and 4) for very strong stratification, the vortex stopped descending and quickly dissipated even before vortex linking could occur. These results are supported by experimental data and are contrary to conclusions from other numerical studies that assume laminar flow and/or relatively-low Reynolds numbers.

Effect of alcaline cations in zeolites on their dielectric properties.

PubMed

Legras, Benoît; Polaert, Isabelle; Estel, Lionel; Thomas, Michel

2012-01-01

The effect on dielectric properties of alkaline cations Li+, Na+ and K+ incorporated in a zeolite Faujasite structure X or Y, has been investigated. Two major phenomena have been proved to occur: ionic conductivity and rotational polarization of the water molecules adsorbed. The polarizability of the cation which is directly linked to its radius, affects ionic conductivity as well as rotational polarization. Li cations are more strongly Linked to the framework than K+ and Na+ and induce a lower ionic conductivity. K+ is weakly fixed and induces a ionic conductivity even at low solvation level. At low water content, the cation nature and number mainly control the free rotation of the water molecules and affect the relaxation frequency. Close to saturation, the water molecules are mainly linked together by H bonds: the cation nature and number do not really affect the global dielectric properties anymore.

Residential Mobility and Lung Cancer Risk: Data-Driven Exploration Using Internet Sources

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

Yoon, Hong-Jun; Tourassi, Georgia; Xu, Songhua

2015-01-01

Frequent relocation has been linked to health decline, particularly with respect to emotional and psychological wellbeing. In this paper we investigate whether there is an association between frequent relocation and lung cancer risk. For the initial investigation we leverage two online data sources to collect cancer and control subjects using web crawling and tailored text mining. The two data sources share different strengths and weaknesses in terms of the amount of detail, population representation, and sample size. One data source includes online obituaries. The second data source includes augmented LinkedIn profiles. For each data source, the subjects spatiotemporal history ismore » reconstructed from the available information provided in the obituaries and from the education and work experience provided in the LinkedIn profiles. The study shows that lung cancer subjects have higher mobility frequency than the control group. This trend is consistent for both data sources.« less

Average BER of subcarrier intensity modulated free space optical systems over the exponentiated Weibull fading channels.

PubMed

Wang, Ping; Zhang, Lu; Guo, Lixin; Huang, Feng; Shang, Tao; Wang, Ranran; Yang, Yintang

2014-08-25

The average bit error rate (BER) for binary phase-shift keying (BPSK) modulation in free-space optical (FSO) links over turbulence atmosphere modeled by the exponentiated Weibull (EW) distribution is investigated in detail. The effects of aperture averaging on the average BERs for BPSK modulation under weak-to-strong turbulence conditions are studied. The average BERs of EW distribution are compared with Lognormal (LN) and Gamma-Gamma (GG) distributions in weak and strong turbulence atmosphere, respectively. The outage probability is also obtained for different turbulence strengths and receiver aperture sizes. The analytical results deduced by the generalized Gauss-Laguerre quadrature rule are verified by the Monte Carlo simulation. This work is helpful for the design of receivers for FSO communication systems.

Solid polymeric electrolytes for lithium batteries

DOEpatents

Angell, Charles A.; Xu, Wu; Sun, Xiaoguang

2006-03-14

Novel conductive polyanionic polymers and methods for their preparion are provided. The polyanionic polymers comprise repeating units of weakly-coordinating anionic groups chemically linked to polymer chains. The polymer chains in turn comprise repeating spacer groups. Spacer groups can be chosen to be of length and structure to impart desired electrochemical and physical properties to the polymers. Preferred embodiments are prepared from precursor polymers comprising the Lewis acid borate tri-coordinated to a selected ligand and repeating spacer groups to form repeating polymer chain units. These precursor polymers are reacted with a chosen Lewis base to form a polyanionic polymer comprising weakly coordinating anionic groups spaced at chosen intervals along the polymer chain. The polyanionic polymers exhibit high conductivity and physical properties which make them suitable as solid polymeric electrolytes in lithium batteries, especially secondary lithium batteries.

High-Performance Liquid Chromatography-Mass Spectrometry.

ERIC Educational Resources Information Center

Vestal, Marvin L.

1984-01-01

Reviews techniques for online coupling of high-performance liquid chromatography with mass spectrometry, emphasizing those suitable for application to nonvolatile samples. Also summarizes the present status, strengths, and weaknesses of various techniques and discusses potential applications of recently developed techniques for combined liquid…

New Developments in Error Detection and Correction Strategies for Critical Applications

NASA Technical Reports Server (NTRS)

Berg, Melanie; Label, Ken

2017-01-01

The presentation will cover a variety of mitigation strategies that were developed for critical applications. An emphasis is placed on strengths and weaknesses per mitigation technique as it pertains to different Field programmable gate array (FPGA) device types.

Application of the stochastic resonance algorithm to the simultaneous quantitative determination of multiple weak peaks of ultra-performance liquid chromatography coupled to time-of-flight mass spectrometry.

PubMed

Deng, Haishan; Shang, Erxin; Xiang, Bingren; Xie, Shaofei; Tang, Yuping; Duan, Jin-ao; Zhan, Ying; Chi, Yumei; Tan, Defei

2011-03-15

The stochastic resonance algorithm (SRA) has been developed as a potential tool for amplifying and determining weak chromatographic peaks in recent years. However, the conventional SRA cannot be applied directly to ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC/TOFMS). The obstacle lies in the fact that the narrow peaks generated by UPLC contain high-frequency components which fall beyond the restrictions of the theory of stochastic resonance. Although there already exists an algorithm that allows a high-frequency weak signal to be detected, the sampling frequency of TOFMS is not fast enough to meet the requirement of the algorithm. Another problem is the depression of the weak peak of the compound with low concentration or weak detection response, which prevents the simultaneous determination of multi-component UPLC/TOFMS peaks. In order to lower the frequencies of the peaks, an interpolation and re-scaling frequency stochastic resonance (IRSR) is proposed, which re-scales the peak frequencies via linear interpolating sample points numerically. The re-scaled UPLC/TOFMS peaks could then be amplified significantly. By introducing an external energy field upon the UPLC/TOFMS signals, the method of energy gain was developed to simultaneously amplify and determine weak peaks from multi-components. Subsequently, a multi-component stochastic resonance algorithm was constructed for the simultaneous quantitative determination of multiple weak UPLC/TOFMS peaks based on the two methods. The optimization of parameters was discussed in detail with simulated data sets, and the applicability of the algorithm was evaluated by quantitative analysis of three alkaloids in human plasma using UPLC/TOFMS. The new algorithm behaved well in the improvement of signal-to-noise (S/N) compared to several normally used peak enhancement methods, including the Savitzky-Golay filter, Whittaker-Eilers smoother and matched filtration. Copyright © 2011 John Wiley & Sons, Ltd.

Microbial mutagenic effects of the DNA minor groove binder pibenzimol (Hoechst 33258) and a series of mustard analogues.

PubMed

Ferguson, L R; Denny, W A

1995-06-01

A series of aniline mustards and half-mustards targeted to DNA by linkage (through a polymethylene chain) to the bisbenzimidazole chromophore of pibenzimol (Hoechst 33258) have been evaluated for their mutagenic properties, as estimated in three strains of Salmonella typhimurium, and for their mitotic crossing-over and petite mutagenesis activities in Saccharomyces cerevisiae strain D5. Agarose gel electrophoresis studies showed that only the derivative with the longest linker chain cross-linked DNA, with the remaining compounds being monoalkylators. The parent (non-alkylator) minor groove binding ligand (Hoechst 33258) was inactive in the bacterial strains TA98 or TA100 but weakly mutagenic in TA102, and caused neither mitotic crossing-over nor 'petite' mutagenesis in yeast. Aniline half-mustard itself (monoalkylator) was an effective base-pair substitution mutagen (events in S. typhimurium strain TA100) with some frameshift mutagenesis activity in TA98, but showed only weak effects in the yeast assays, whereas aniline mustard (cross-linker) was inactive in these bacterial systems but caused substantial amounts of mitotic crossing-over in yeast. The composite molecules studied here showed effects more characteristic of the minor groove binding chromophore than of alkylating moieties. All showed weak mutagenic activity in TA102 and none in TA98. The only compound to show significant mitotic crossing-over ability was the long-chain derivative which cross-linked DNA. For most of the compounds, the mutagenicity data provided no supportive evidence for DNA alkylation. Since other evidence suggests this does occur readily, it is likely to have a different target to that seen with untargeted aniline mustards. The significant antitumor activity and low mutagenic potential shown by these compounds make them worthy of further study.

ENSO-driven energy budget perturbations in observations and CMIP models

DOE PAGES

Mayer, Michael; Fasullo, John T.; Trenberth, Kevin E.; ...

2016-03-19

Various observation-based datasets are employed to robustly quantify changes in ocean heat content (OHC), anomalous ocean–atmosphere energy exchanges and atmospheric energy transports during El Niño-Southern Oscillation (ENSO). These results are used as a benchmark to evaluate the energy pathways during ENSO as simulated by coupled climate model runs from the CMIP3 and CMIP5 archives. The models are able to qualitatively reproduce observed patterns of ENSO-related energy budget variability to some degree, but key aspects are seriously biased. Area-averaged tropical Pacific OHC variability associated with ENSO is greatly underestimated by all models because of strongly biased responses of net radiation atmore » top-of-the-atmosphere to ENSO. The latter are related to biases of mean convective activity in the models and project on surface energy fluxes in the eastern Pacific Intertropical Convergence Zone region. Moreover, models underestimate horizontal and vertical OHC redistribution in association with the generally too weak Bjerknes feedback, leading to a modeled ENSO affecting a too shallow layer of the Pacific. Vertical links between SST and OHC variability are too weak even in models driven with observed winds, indicating shortcomings of the ocean models. Furthermore, modeled teleconnections as measured by tropical Atlantic OHC variability are too weak and the tropical zonal mean ENSO signal is strongly underestimated or even completely missing in most of the considered models. In conclusion, results suggest that attempts to infer insight about climate sensitivity from ENSO-related variability are likely to be hampered by biases in ENSO in CMIP simulations that do not bear a clear link to future changes.« less

Crystal structure of (4-cyano­pyridine-κN){5,10,15,20-tetrakis[4-(benzoyloxy)phenyl]porphyrinato-κ4 N}zinc–4-cyano­pyridine (1/1)

PubMed Central

Nasri, Soumaya; Amiri, Nesrine; Turowska-Tyrk, Ilona; Daran, Jean-Claude; Nasri, Habib

2016-01-01

In the title compound, [Zn(C72H44N4O8)(C6H4N2)]·C6H4N2 or [Zn(TPBP)(4-CNpy]·(4-CNpy) [where TPBP and 4-CNpy are 5,10,15,20-(tetra­phenyl­benzoate)porphyrinate and 4-cyano­pyridine, respectively], the ZnII cation is chelated by four pyrrole-N atoms of the porphyrinate anion and coordinated by a pyridyl-N atom of the 4-CNpy axial ligand in a distorted square-pyramidal geometry. The average Zn—N(pyrrole) bond length is 2.060 (6) Å and the Zn—N(4-CNpy) bond length is 2.159 (2) Å. The zinc cation is displaced by 0.319 (1) Å from the N4C20 mean plane of the porphyrinate anion toward the 4-cyano­pyridine axial ligand. This porphyrinate macrocycle exhibits major saddle and moderate ruffling and doming deformations. In the crystal, the [Zn(TPBP)(4-CNpy)] complex mol­ecules are linked together via weak C—H⋯N, C—H⋯O and C—H⋯π inter­actions, forming supra­molecular channels parallel to the c axis. The non-coordinating 4-cyano­pyridine mol­ecules are located in the channels and linked with the complex mol­ecules, via weak C—H⋯N inter­actions and π-π stacking or via weak C—H⋯O and C—H⋯π inter­actions. The non-coordinating 4-cyano­pyridine mol­ecule is disordered over two positions with an occupancy ratio of 0.666 (4):0.334 (4). PMID:26958379

CAVIAR: CLASSIFICATION VIA AGGREGATED REGRESSION AND ITS APPLICATION IN CLASSIFYING OASIS BRAIN DATABASE

PubMed Central

Chen, Ting; Rangarajan, Anand; Vemuri, Baba C.

2010-01-01

This paper presents a novel classification via aggregated regression algorithm – dubbed CAVIAR – and its application to the OASIS MRI brain image database. The CAVIAR algorithm simultaneously combines a set of weak learners based on the assumption that the weight combination for the final strong hypothesis in CAVIAR depends on both the weak learners and the training data. A regularization scheme using the nearest neighbor method is imposed in the testing stage to avoid overfitting. A closed form solution to the cost function is derived for this algorithm. We use a novel feature – the histogram of the deformation field between the MRI brain scan and the atlas which captures the structural changes in the scan with respect to the atlas brain – and this allows us to automatically discriminate between various classes within OASIS [1] using CAVIAR. We empirically show that CAVIAR significantly increases the performance of the weak classifiers by showcasing the performance of our technique on OASIS. PMID:21151847

CAVIAR: CLASSIFICATION VIA AGGREGATED REGRESSION AND ITS APPLICATION IN CLASSIFYING OASIS BRAIN DATABASE.

PubMed

Chen, Ting; Rangarajan, Anand; Vemuri, Baba C

2010-04-14

This paper presents a novel classification via aggregated regression algorithm - dubbed CAVIAR - and its application to the OASIS MRI brain image database. The CAVIAR algorithm simultaneously combines a set of weak learners based on the assumption that the weight combination for the final strong hypothesis in CAVIAR depends on both the weak learners and the training data. A regularization scheme using the nearest neighbor method is imposed in the testing stage to avoid overfitting. A closed form solution to the cost function is derived for this algorithm. We use a novel feature - the histogram of the deformation field between the MRI brain scan and the atlas which captures the structural changes in the scan with respect to the atlas brain - and this allows us to automatically discriminate between various classes within OASIS [1] using CAVIAR. We empirically show that CAVIAR significantly increases the performance of the weak classifiers by showcasing the performance of our technique on OASIS.

Second Order Boltzmann-Gibbs Principle for Polynomial Functions and Applications

NASA Astrophysics Data System (ADS)

Gonçalves, Patrícia; Jara, Milton; Simon, Marielle

2017-01-01

In this paper we give a new proof of the second order Boltzmann-Gibbs principle introduced in Gonçalves and Jara (Arch Ration Mech Anal 212(2):597-644, 2014). The proof does not impose the knowledge on the spectral gap inequality for the underlying model and it relies on a proper decomposition of the antisymmetric part of the current of the system in terms of polynomial functions. In addition, we fully derive the convergence of the equilibrium fluctuations towards (1) a trivial process in case of super-diffusive systems, (2) an Ornstein-Uhlenbeck process or the unique energy solution of the stochastic Burgers equation, as defined in Gubinelli and Jara (SPDEs Anal Comput (1):325-350, 2013) and Gubinelli and Perkowski (Arxiv:1508.07764, 2015), in case of weakly asymmetric diffusive systems. Examples and applications are presented for weakly and partial asymmetric exclusion processes, weakly asymmetric speed change exclusion processes and hamiltonian systems with exponential interactions.

Automating hypertext for decision support

NASA Technical Reports Server (NTRS)

Bieber, Michael

1990-01-01

A decision support system (DSS) shell is being constructed that can support applications in a variety of fields, e.g., engineering, manufacturing, finance. The shell provides a hypertext-style interface for 'navigating' among DSS application models, data, and reports. The traditional notion of hypertext had to be enhanced. Hypertext normally requires manually, pre-defined links. A DSS shell, however, requires that hypertext connections to be built 'on the fly'. The role of hypertext is discussed in augmenting DSS applications and the decision making process. Also discussed is how hypertext nodes, links, and link markers tailored to an arbitrary DSS application were automatically generated.

Serum Osteopontin as a Novel Biomarker for Muscle Regeneration in Duchenne Muscular Dystrophy.

PubMed

Kuraoka, Mutsuki; Kimura, En; Nagata, Tetsuya; Okada, Takashi; Aoki, Yoshitsugu; Tachimori, Hisateru; Yonemoto, Naohiro; Imamura, Michihiro; Takeda, Shin'ichi

2016-05-01

Duchenne muscular dystrophy is a lethal X-linked muscle disorder. We have already reported that osteopontin (OPN), an inflammatory cytokine and myogenic factor, is expressed in the early dystrophic phase in canine X-linked muscular dystrophy in Japan, a dystrophic dog model. To further explore the possibility of OPN as a new biomarker for disease activity in Duchenne muscular dystrophy, we monitored serum OPN levels in dystrophic and wild-type dogs at different ages and compared the levels to other serum markers, such as serum creatine kinase, matrix metalloproteinase-9, and tissue inhibitor of metalloproteinase-1. Serum OPN levels in the dystrophic dogs were significantly elevated compared with those in wild-type dogs before and 1 hour after a cesarean section birth and at the age of 3 months. The serum OPN level was significantly correlated with the phenotypic severity of dystrophic dogs at the period corresponding to the onset of muscle weakness, whereas other serum markers including creatine kinase were not. Immunohistologically, OPN was up-regulated in infiltrating macrophages and developmental myosin heavy chain-positive regenerating muscle fibers in the dystrophic dogs, whereas serum OPN was highly elevated. OPN expression was also observed during the synergic muscle regeneration process induced by cardiotoxin injection. In conclusion, OPN is a promising biomarker for muscle regeneration in dystrophic dogs and can be applicable to boys with Duchenne muscular dystrophy. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Outcome (competency) based education: an exploration of its origins, theoretical basis, and empirical evidence.

PubMed

Morcke, Anne Mette; Dornan, Tim; Eika, Berit

2013-10-01

Outcome based or competency based education (OBE) is so firmly established in undergraduate medical education that it might not seem necessary to ask why it was included in recommendations for the future, like the Flexner centenary report. Uncritical acceptance may not, however, deliver its greatest benefits. Our aim was to explore the underpinnings of OBE: its historical origins, theoretical basis, and empirical evidence of its effects in order to answer the question: How can predetermined learning outcomes influence undergraduate medical education? This literature review had three components: A review of historical landmarks in the evolution of OBE; a review of conceptual frameworks and theories; and a systematic review of empirical publications from 1999 to 2010 that reported data concerning the effects of learning outcomes on undergraduate medical education. OBE had its origins in behaviourist theories of learning. It is tightly linked to the assessment and regulation of proficiency, but less clearly linked to teaching and learning activities. Over time, there have been cycles of advocacy for, then criticism of, OBE. A recurring critique concerns the place of complex personal and professional attributes as "competencies". OBE has been adopted by consensus in the face of weak empirical evidence. OBE, which has been advocated for over 50 years, can contribute usefully to defining requisite knowledge and skills, and blueprinting assessments. Its applicability to more complex aspects of clinical performance is not clear. OBE, we conclude, provides a valuable approach to some, but not all, important aspects of undergraduate medical education.

Crystal structure of bis-(μ-3-nitro-benzoato)-κ3O,O':O;κ3O:O,O'-bis-[bis-(3-cyano-pyridine-κN1)(3-nitro-benzoato-κ2O,O')cadmium].

PubMed

Hökelek, Tuncer; Akduran, Nurcan; Özen, Azer; Uğurlu, Güventürk; Necefoğlu, Hacali

2017-03-01

The asymmetric unit of the title compound, [Cd 2 (C 7 H 4 NO 4 ) 4 (C 6 H 4 N 2 ) 4 ], contains one Cd II atom, two 3-nitro-benzoate (NB) anions and two 3-cyano-pyridine (CPy) ligands. The two CPy ligands act as monodentate N(pyridine)-bonding ligands, while the two NB anions act as bidentate ligands through the carboxyl-ate O atoms. The centrosymmetric dinuclear complex is generated by application of inversion symmetry, whereby the Cd II atoms are bridged by the carboxyl-ate O atoms of two symmetry-related NB anions, thus completing the distorted N 2 O 5 penta-gonal-bipyramidal coordination sphere of each Cd II atom. The benzene and pyridine rings are oriented at dihedral angles of 10.02 (7) and 5.76 (9)°, respectively. In the crystal, C-H⋯N hydrogen bonds link the mol-ecules, enclosing R 2 2 (26) ring motifs, in which they are further linked via C-H⋯O hydrogen bonds, resulting in a three-dimensional network. In addition, π-π stacking inter-actions between parallel benzene rings and between parallel pyridine rings of adjacent mol-ecules [shortest centroid-to-centroid distances = 3.885 (1) and 3.712 (1) Å, respectively], as well as a weak C-H⋯π inter-action, may further stabilize the crystal structure.

Co-Labeling for Multi-View Weakly Labeled Learning.

PubMed

Xu, Xinxing; Li, Wen; Xu, Dong; Tsang, Ivor W

2016-06-01

It is often expensive and time consuming to collect labeled training samples in many real-world applications. To reduce human effort on annotating training samples, many machine learning techniques (e.g., semi-supervised learning (SSL), multi-instance learning (MIL), etc.) have been studied to exploit weakly labeled training samples. Meanwhile, when the training data is represented with multiple types of features, many multi-view learning methods have shown that classifiers trained on different views can help each other to better utilize the unlabeled training samples for the SSL task. In this paper, we study a new learning problem called multi-view weakly labeled learning, in which we aim to develop a unified approach to learn robust classifiers by effectively utilizing different types of weakly labeled multi-view data from a broad range of tasks including SSL, MIL and relative outlier detection (ROD). We propose an effective approach called co-labeling to solve the multi-view weakly labeled learning problem. Specifically, we model the learning problem on each view as a weakly labeled learning problem, which aims to learn an optimal classifier from a set of pseudo-label vectors generated by using the classifiers trained from other views. Unlike traditional co-training approaches using a single pseudo-label vector for training each classifier, our co-labeling approach explores different strategies to utilize the predictions from different views, biases and iterations for generating the pseudo-label vectors, making our approach more robust for real-world applications. Moreover, to further improve the weakly labeled learning on each view, we also exploit the inherent group structure in the pseudo-label vectors generated from different strategies, which leads to a new multi-layer multiple kernel learning problem. Promising results for text-based image retrieval on the NUS-WIDE dataset as well as news classification and text categorization on several real-world multi-view datasets clearly demonstrate that our proposed co-labeling approach achieves state-of-the-art performance for various multi-view weakly labeled learning problems including multi-view SSL, multi-view MIL and multi-view ROD.

Stakeholder perceptions of Environmental Management Plans as an environmental protection tool for major developments in the UK

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

Bennett, Sophie; Kemp, Simon; Hudson, Malcolm D., E-mail: mdh@soton.ac.uk

Insufficient implementation and the lack of legislative requirements for follow-up measures following the approval of projects are consistently highlighted as major shortcomings of Environmental Impact Assessment (EIA). Although adopted over 15 years ago by the World Bank, Environmental Management Plans (EMPs) were only semi-formalised in the UK in 2008 and arguably provide a continuous link or ‘bridge’ between the EIA process pre-consent and an Environmental Management System (EMS) post-consent. Drawing on twenty-one semi-structured interviews with stakeholders and thematic analysis of their responses, and a broad-scale practitioner survey, this study aimed to assess the effectiveness of EMPs as an environmental protectionmore » tool across the project lifecycle for major developments. The findings revealed a mixed picture of EMP effectiveness in practice, with EMPs only partially fulfilling a bridging role between EIA and EMS. There is no ‘gold standard’ terminology for EMPs, all having slightly different uses, thus presenting different focuses to different stakeholders and further enhancing variation in practice. For many stakeholders, the effectiveness was simply not known, due to the lack of communication and follow-up that still exists. EMP–EMS linkages were shown to be effective from the developer's perspective when a single organisation has involvement across all project phases, though weaknesses occur when multiple parties are involved. Among other stakeholders, knowledge varied significantly; whilst some were in agreement that the linkages worked, many were unaware of the connections and thought of them as two quite separate tools. Stakeholders advocated for the need to make EMPs a legal requirement; for improved communication between stakeholders during EMP implementation and increased documentation of project outcomes; and for EMPs to be consistently written by environmental professionals. Furthermore, weak links in the current process may be improved by providing detailed guidance for organisations on the potential for EMP–EMS linkages, with the additional aim of encouraging stakeholders to broaden their current specialist knowledge on environmental protection tools. - Highlights: • We assessed the effectiveness of Environmental Management Plans (EMPs) for major developments, focusing on delivery of mitigation and monitoring. • EIA and Environmental Management Systems (EMS) post-consent are weakly linked. • The use of EMPs varies significantly in practise, partly due to the range of terminology used. • Linkages are hampered by poor communication and follow-up • More detailed guidance on how EMPs can successfully link with EMS is required.« less

Quantum controlled-Z gate for weakly interacting qubits

NASA Astrophysics Data System (ADS)

Mičuda, Michal; Stárek, Robert; Straka, Ivo; Miková, Martina; Dušek, Miloslav; Ježek, Miroslav; Filip, Radim; Fiurášek, Jaromír

2015-08-01

We propose and experimentally demonstrate a scheme for the implementation of a maximally entangling quantum controlled-Z gate between two weakly interacting systems. We conditionally enhance the interqubit coupling by quantum interference. Both before and after the interqubit interaction, one of the qubits is coherently coupled to an auxiliary quantum system, and finally it is projected back onto qubit subspace. We experimentally verify the practical feasibility of this technique by using a linear optical setup with weak interferometric coupling between single-photon qubits. Our procedure is universally applicable to a wide range of physical platforms including hybrid systems such as atomic clouds or optomechanical oscillators coupled to light.

Bivariate spline solution of time dependent nonlinear PDE for a population density over irregular domains.

PubMed

Gutierrez, Juan B; Lai, Ming-Jun; Slavov, George

2015-12-01

We study a time dependent partial differential equation (PDE) which arises from classic models in ecology involving logistic growth with Allee effect by introducing a discrete weak solution. Existence, uniqueness and stability of the discrete weak solutions are discussed. We use bivariate splines to approximate the discrete weak solution of the nonlinear PDE. A computational algorithm is designed to solve this PDE. A convergence analysis of the algorithm is presented. We present some simulations of population development over some irregular domains. Finally, we discuss applications in epidemiology and other ecological problems. Copyright © 2015 Elsevier Inc. All rights reserved.

Practical application of thermoreversibly Cross-linked rubber products

NASA Astrophysics Data System (ADS)

Polgar, L. M.; Picchioni, F.; de Ruiter, E.; van Duin, M.

2017-07-01

Currently, rubber products cannot simply be reprocessed after their product life, due to the irreversible cross-linking methods traditionally applied. The purpose of this work is to investigate how thermoreversible cross-linking of rubbers via Diels Alder chemistry can be used for the development of recyclable rubber products. Unfortunately, the applicability of the thermoreversible EPM-g-furan/BM system appears to be limited to room temperature applications, because of the rapid deterioration of the compression set at elevated temperatures compared to irreversibly cross-linked EPM. However, the use of EPM rubber modified with thiophene or cyclopentadiene moieties may extend the temperature application range and results in rubber products with acceptable properties. Finally, rubber products generally comprise fillers such as silica, carbon black or fibers. In this context, the reinforcing effect of short cut aramid fibers on the material properties of the newly developed thermoreversibly cross-linked EPM rubbers was also studied. The material properties of the resulting products were found to be comparable to those of a fiber reinforced, peroxide cured reference sample.

Network formation: neighborhood structures, establishment costs, and distributed learning.

PubMed

Chasparis, Georgios C; Shamma, Jeff S

2013-12-01

We consider the problem of network formation in a distributed fashion. Network formation is modeled as a strategic-form game, where agents represent nodes that form and sever unidirectional links with other nodes and derive utilities from these links. Furthermore, agents can form links only with a limited set of neighbors. Agents trade off the benefit from links, which is determined by a distance-dependent reward function, and the cost of maintaining links. When each agent acts independently, trying to maximize its own utility function, we can characterize “stable” networks through the notion of Nash equilibrium. In fact, the introduced reward and cost functions lead to Nash equilibria (networks), which exhibit several desirable properties such as connectivity, bounded-hop diameter, and efficiency (i.e., minimum number of links). Since Nash networks may not necessarily be efficient, we also explore the possibility of “shaping” the set of Nash networks through the introduction of state-based utility functions. Such utility functions may represent dynamic phenomena such as establishment costs (either positive or negative). Finally, we show how Nash networks can be the outcome of a distributed learning process. In particular, we extend previous learning processes to so-called “state-based” weakly acyclic games, and we show that the proposed network formation games belong to this class of games.

Margins Associated with Loss of Assured Safety for Systems with Multiple Time-Dependent Failure Modes.

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

Helton, Jon C.; Brooks, Dusty Marie; Sallaberry, Cedric Jean-Marie.

Representations for margins associated with loss of assured safety (LOAS) for weak link (WL)/strong link (SL) systems involving multiple time-dependent failure modes are developed. The following topics are described: (i) defining properties for WLs and SLs, (ii) background on cumulative distribution functions (CDFs) for link failure time, link property value at link failure, and time at which LOAS occurs, (iii) CDFs for failure time margins defined by (time at which SL system fails) – (time at which WL system fails), (iv) CDFs for SL system property values at LOAS, (v) CDFs for WL/SL property value margins defined by (property valuemore » at which SL system fails) – (property value at which WL system fails), and (vi) CDFs for SL property value margins defined by (property value of failing SL at time of SL system failure) – (property value of this SL at time of WL system failure). Included in this presentation is a demonstration of a verification strategy based on defining and approximating the indicated margin results with (i) procedures based on formal integral representations and associated quadrature approximations and (ii) procedures based on algorithms for sampling-based approximations.« less

Formation flying design and applications in weak stability boundary regions.

PubMed

Folta, David

2004-05-01

Weak stability regions serve as superior locations for interferomertric scientific investigations. These regions are often selected to minimize environmental disturbances and maximize observation efficiency. Designs of formations in these regions are becoming ever more challenging as more complex missions are envisioned. The development of algorithms to enable the capability for formation design must be further enabled to incorporate better understanding of weak stability boundary solution space. This development will improve the efficiency and expand the capabilities of current approaches. The Goddard Space Flight Center (GSFC) is currently supporting multiple formation missions in weak stability boundary regions. This end-to-end support consists of mission operations, trajectory design, and control. It also includes both algorithm and software development. The Constellation-X, Maxim, and Stellar Imager missions are examples of the use of improved numeric methods to attain constrained formation geometries and control their dynamical evolution. This paper presents a survey of formation missions in the weak stability boundary regions and a brief description of formation design using numerical and dynamical techniques.

Crystal structures of five (2-chloro­quinolin-3-yl)methyl ethers: supra­molecular assembly in one and two dimensions mediated by hydrogen bonding and π–π stacking

PubMed Central

Sowmya, Haliwana B. V.; Suresha Kumara, Tholappanavara H.; Gopalpur, Nagendrappa; Jasinski, Jerry P.; Millikan, Sean P.; Yathirajan, Hemmige S.; Glidewell, Christopher

2015-01-01

In the mol­ecules of the title compounds, methyl 5-bromo-2-[(2-chloro­quinolin-3-yl)meth­oxy]benzoate, C18H13BrClNO3, (I), methyl 5-bromo-2-[(2-chloro-6-methyl­quinolin-3-yl)meth­oxy]benzoate, C19H15BrClNO3, (II), methyl 2-[(2-chloro-6-methyl­quinolin-3-yl)meth­oxy]benzoate, C19H16ClNO3, (III), which crystallizes with Z′ = 4 in space group P212121, and 2-chloro-3-[(naphthalen-1-yl­oxy)meth­yl]quinoline, C20H14ClNO, (IV), the non-H atoms are nearly coplanar, but in {5-[(2-chloro­quinolin-3-yl)meth­oxy]-4-(hy­droxy­meth­yl)-6-methyl­pyridin-3-yl}methanol, C18H17ClN2O3, (V), the planes of the quinoline unit and of the unfused pyridine ring are almost parallel, although not coplanar. The mol­ecules of (I) are linked by two independent π–π stacking inter­actions to form chains, but there are no hydrogen bonds present in the structure. In (II), the mol­ecules are weakly linked into chains by a single type of π–π stacking inter­action. In (III), three of the four independent mol­ecules are linked by π–π stacking inter­actions but the other mol­ecule does not participate in such inter­actions. Weak C—H⋯O hydrogen bonds link the mol­ecules into three types of chains, two of which contain just one type of independent mol­ecule while the third type of chain contains two types of mol­ecule. The mol­ecules of (IV) are linked into chains by a C—H⋯π(arene) hydrogen bond, but π–π stacking inter­actions are absent. In (V), there is an intra­molecular O—H⋯O hydrogen bond, and mol­ecules are linked into sheets by a combination of O—H⋯N hydrogen bonds and π–π stacking inter­actions. PMID:26090133

Crystal Structures of New Ammonium 5-Aminotetrazolates

PubMed Central

Lampl, Martin; Salchner, Robert; Laus, Gerhard; Braun, Doris E.; Kahlenberg, Volker; Wurst, Klaus; Fuhrmann, Gerda; Schottenberger, Herwig; Huppertz, Hubert

2015-01-01

The crystal structures of three salts of anionic 5-aminotetrazole are described. The tetramethylammonium salt (P1‒) forms hydrogen-bonded ribbons of anions which accept weak C–H⋯N contacts from the cations. The cystamine salt (C2/c) shows wave-shaped ribbons of anions linked by hydrogen bonds to screw-shaped dications. The tetramethylguanidine salt (P21/c) exhibits layers of anions hydrogen-bonded to the cations. PMID:26753100

Diethyl 2-{[(4-meth­oxy-3-pyrid­yl)amino]­methyl­idene}malonate

PubMed Central

Zhang, Zhi-Fang

2011-01-01

In the title mol­ecule, C14H8N2O5, the amino group is involved in the formation an intra­molecular N—H⋯O hydrogen bond. In the crystal, weak inter­molecular C—H⋯O and C—H⋯N hydrogen bonds link the mol­ecules into ribbons along the b axis. PMID:22090989

Fringe Field Superconducting Switch

DTIC Science & Technology

1997-10-31

However, it is not believed that any known superconducting switch has all of these desirable 3 properties . 4 Many known superconducting devices rely on...will recognize, a weak link is a structure that does not in itself have superconducting properties , but 7 will allow a relatively small flow of tunnel... properties of the junction. 12 Thus, the operating parameters of conventional Josephson junctions tend to drift over time. This 13 shortcoming of

Preparing Women for Strategic Leadership Roles in the Army

DTIC Science & Technology

2003-03-01

organization. Male dominated professions tend to look for experience and interaction that they can measure such as field exercises and sporting events...Diverse Work Force”, The Leader of the Future, Josey-Bass Publishers, San Francisco, CA, 1996, p.78. 23 Brian Mitchell, “Weak Link: The Feminization of... Feminization of the American Military, Washington, D.C.: Regency Gateway, 1989. Robbins, Stephen P., Organizational Behavior, New York, NY: Prentice Hall

3-Chloro-4-methyl­quinolin-2(1H)-one

PubMed Central

Kassem, Mohamed G.; Ghabbour, Hazem A.; Abdel-Aziz, Hatem A.; Fun, Hoong-Kun; Ooi, Chin Wei

2012-01-01

The title compound, C10H8ClNO, is almost planar (r.m.s. deviation for the 13 non-H atoms = 0.023 Å). In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds generate R 2 2(8) rings. Weak aromatic π–π stacking inter­actions [centroid–centroid distance = 3.7622 (12) Å] also occur. PMID:22589913

Reduction of Risk for Low Back Injury in Theater of Operations

DTIC Science & Technology

2015-06-01

Assessed for eligibility (n = 698) 14 Figure 4. Predicted (from regression) isometric lumbar extension strength ( torque ) mean values (adjusted by...resistance exercise to the lumbar extensors in the ranges required for strength development, torque production from the gluteals and hamstrings must be...the small lumbar muscles play only a minor role in trunk extension torque production.17 Thus, they are considered to be the weak link in trunk

A recurrence network approach to analyzing forced synchronization in hydrodynamic systems

NASA Astrophysics Data System (ADS)

Murugesan, Meenatchidevi; Zhu, Yuanhang; Li, Larry K. B.

2016-11-01

Hydrodynamically self-excited systems can lock into external forcing, but their lock-in boundaries and the specific bifurcations through which they lock in can be difficult to detect. We propose using recurrence networks to analyze forced synchronization in a hydrodynamic system: a low-density jet. We find that as the jet bifurcates from periodicity (unforced) to quasiperiodicity (weak forcing) and then to lock-in (strong forcing), its recurrence network changes from a regular distribution of links between nodes (unforced) to a disordered topology (weak forcing) and then to a regular distribution again at lock-in (strong forcing). The emergence of order at lock-in can be either smooth or abrupt depending on the specific lock-in route taken. Furthermore, we find that before lock-in, the probability distribution of links in the network is a function of the characteristic scales of the system, which can be quantified with network measures and used to estimate the proximity to the lock-in boundaries. This study shows that recurrence networks can be used (i) to detect lock-in, (ii) to distinguish between different routes to lock-in, and (iii) as an early warning indicator of the proximity of a system to its lock-in boundaries. This work was supported by the Research Grants Council of Hong Kong (Project No. 16235716 and 26202815).

Effects of moiré lattice structure on electronic properties of graphene

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

Huang, Lunan; Wu, Yun; Hershberger, M. T.

Here, we study structural and electronic properties of graphene grown on silicone carbide (SiC) substrate using a scanning tunneling microscope, spot-profile-analysis low-energy electron diffraction, and angle-resolved photoemission spectroscopy. We find several new replicas of Dirac cones in the Brillouin zone. Their locations can be understood in terms of a combination of basis vectors linked to SiC 6 × 6 and graphene 6√3×6√3 reconstruction. Therefore, these new features originate from the moiré caused by the lattice mismatch between SiC and graphene. More specifically, Dirac cone replicas are caused by underlying weak modulation of the ionic potential by the substrate that ismore » then experienced by the electrons in the graphene. We also demonstrate that this effect is equally strong in single- and trilayer graphene; therefore, the additional Dirac cones are intrinsic features rather than the result of photoelectron diffraction. These new features in the electronic structure are very important for the interpretation of recent transport measurements and can assist in tuning the properties of graphene for practical applications.« less

Surface-Enhanced Raman Spectroscopy of Carbon Nanomembranes from Aromatic Self-Assembled Monolayers.

PubMed

Zhang, Xianghui; Mainka, Marcel; Paneff, Florian; Hachmeister, Henning; Beyer, André; Gölzhäuser, Armin; Huser, Thomas

2018-02-27

Surface-enhanced Raman scattering spectroscopy (SERS) was employed to investigate the formation of self-assembled monolayers (SAMs) of biphenylthiol, 4'-nitro-1,1'-biphenyl-4-thiol, and p-terphenylthiol on Au surfaces and their structural transformations into carbon nanomembranes (CNMs) induced by electron irradiation. The high sensitivity of SERS allows us to identify two types of Raman scattering in electron-irradiated SAMs: (1) Raman-active sites exhibit similar bands as those of pristine SAMs in the fingerprint spectral region, but with indications of an amorphization process and (2) Raman-inactive sites show almost no Raman-scattering signals, except a very weak and broad D band, indicating a lack of structural order but for the presence of graphitic domains. Statistical analysis showed that the ratio of the number of Raman-active sites to the total number of measurement sites decreases exponentially with increasing the electron irradiation dose. The maximum degree of cross-linking ranged from 97 to 99% for the three SAMs. Proof-of-concept experiments were conducted to demonstrate potential applications of Raman-inactive CNMs as a supporting membrane for Raman analysis.

Mapping of reproductive health financing: methodological challenges.

PubMed

Pradhan, Jalandhar; Sidze, Estelle Monique; Khanna, Anoop; Beekink, Erik

2014-10-01

Low level of funding for reproductive health (RH) is a cause for concern, given that RH service utilization in the vast majority of the developing world is well below the desired level. Though there is an urgent need to track the domestic and international financial resource flows for RH, the instruments through which financial resources are tracked in developing countries are limited. In this paper we examined the methodological and conceptual challenges of monitoring financial resources for RH services at international and national level. At the international level, there are a number of estimates that highlights the need for financial resources for RH programmes but the estimates vary significantly. At the national level, Reproductive Health Accounts (RHA) in the framework of National Health Accounts (NHA) is considered to be the ideal source to track domestic financial flows for RH activities. However, the weak link between data production by the RHA and its application by the stakeholders as well as lack of political will impedes the institutionalization of RHA at the country level. Copyright © 2014 Elsevier B.V. All rights reserved.

Heating Structures Derived from Satellite

NASA Technical Reports Server (NTRS)

Tao, W.-K.; Adler, R.; Haddad, Z.; Hou, A.; Kakar, R.; Krishnamurti, T. N.; Kummerow, C.; Lang, S.; Meneghini, R.; Olson, W.

2004-01-01

Rainfall is a key link in the hydrologic cycle and is a primary heat source for the atmosphere. The vertical distribution of latent-heat release, which is accompanied by rainfall, modulates the large-scale circulations of the tropics and in turn can impact midlatitude weather. This latent heat release is a consequence of phase changes between vapor, liquid, and solid water. The Tropical Rainfall Measuring Mission (TRMM), a joint U.S./Japan space project, was launched in November 1997. It provides an accurate measurement of rainfall over the global tropics which can be used to estimate the four-dimensional structure of latent heating over the global tropics. The distributions of rainfall and inferred heating can be used to advance our understanding of the global energy and water cycle. This paper describes several different algorithms for estimating latent heating using TRMM observations. The strengths and weaknesses of each algorithm as well as the heating products are also discussed. The validation of heating products will be exhibited. Finally, the application of this heating information to global circulation and climate models is presented.

Application Research of Horn Array Multi-Beam Antenna in Reference Source System for Satellite Interference Location

NASA Astrophysics Data System (ADS)

Zhou, Ping; Lin, Hui; Zhang, Qi

2018-01-01

The reference source system is a key factor to ensure the successful location of the satellite interference source. Currently, the traditional system used a mechanical rotating antenna which leaded to the disadvantages of slow rotation and high failure-rate, which seriously restricted the system’s positioning-timeliness and became its obvious weaknesses. In this paper, a multi-beam antenna scheme based on the horn array was proposed as a reference source for the satellite interference location, which was used as an alternative to the traditional reference source antenna. The new scheme has designed a small circularly polarized horn antenna as an element and proposed a multi-beamforming algorithm based on planar array. Moreover, the simulation analysis of horn antenna pattern, multi-beam forming algorithm and simulated satellite link cross-ambiguity calculation have been carried out respectively. Finally, cross-ambiguity calculation of the traditional reference source system has also been tested. The comparison between the results of computer simulation and the actual test results shows that the scheme is scientific and feasible, obviously superior to the traditional reference source system.

Control of single-electron charging of metallic nanoparticles onto amorphous silicon surface.

PubMed

Weis, Martin; Gmucová, Katarína; Nádazdy, Vojtech; Capek, Ignác; Satka, Alexander; Kopáni, Martin; Cirák, Július; Majková, Eva

2008-11-01

Sequential single-electron charging of iron oxide nanoparticles encapsulated in oleic acid/oleyl amine envelope and deposited by the Langmuir-Blodgett technique onto Pt electrode covered with undoped hydrogenated amorphous silicon film is reported. Single-electron charging (so-called quantized double-layer charging) of nanoparticles is detected by cyclic voltammetry as current peaks and the charging effect can be switched on/off by the electric field in the surface region induced by the excess of negative/positive charged defect states in the amorphous silicon layer. The particular charge states in amorphous silicon are created by the simultaneous application of a suitable bias voltage and illumination before the measurement. The influence of charged states on the electric field in the surface region is evaluated by the finite element method. The single-electron charging is analyzed by the standard quantized double layer model as well as two weak-link junctions model. Both approaches are in accordance with experiment and confirm single-electron charging by tunnelling process at room temperature. This experiment illustrates the possibility of the creation of a voltage-controlled capacitor for nanotechnology.

A derivation and scalable implementation of the synchronous parallel kinetic Monte Carlo method for simulating long-time dynamics

NASA Astrophysics Data System (ADS)

Byun, Hye Suk; El-Naggar, Mohamed Y.; Kalia, Rajiv K.; Nakano, Aiichiro; Vashishta, Priya

2017-10-01

Kinetic Monte Carlo (KMC) simulations are used to study long-time dynamics of a wide variety of systems. Unfortunately, the conventional KMC algorithm is not scalable to larger systems, since its time scale is inversely proportional to the simulated system size. A promising approach to resolving this issue is the synchronous parallel KMC (SPKMC) algorithm, which makes the time scale size-independent. This paper introduces a formal derivation of the SPKMC algorithm based on local transition-state and time-dependent Hartree approximations, as well as its scalable parallel implementation based on a dual linked-list cell method. The resulting algorithm has achieved a weak-scaling parallel efficiency of 0.935 on 1024 Intel Xeon processors for simulating biological electron transfer dynamics in a 4.2 billion-heme system, as well as decent strong-scaling parallel efficiency. The parallel code has been used to simulate a lattice of cytochrome complexes on a bacterial-membrane nanowire, and it is broadly applicable to other problems such as computational synthesis of new materials.

Effects of moiré lattice structure on electronic properties of graphene

NASA Astrophysics Data System (ADS)

Huang, Lunan; Wu, Yun; Hershberger, M. T.; Mou, Daixiang; Schrunk, Benjamin; Tringides, Michael C.; Hupalo, Myron; Kaminski, Adam

2017-07-01

We study structural and electronic properties of graphene grown on silicone carbide (SiC) substrate using a scanning tunneling microscope, spot-profile-analysis low-energy electron diffraction, and angle-resolved photoemission spectroscopy. We find several new replicas of Dirac cones in the Brillouin zone. Their locations can be understood in terms of a combination of basis vectors linked to SiC 6 × 6 and graphene 6 √{3 }×6 √{3 } reconstruction. Therefore, these new features originate from the moiré caused by the lattice mismatch between SiC and graphene. More specifically, Dirac cone replicas are caused by underlying weak modulation of the ionic potential by the substrate that is then experienced by the electrons in the graphene. We also demonstrate that this effect is equally strong in single- and trilayer graphene; therefore, the additional Dirac cones are intrinsic features rather than the result of photoelectron diffraction. These new features in the electronic structure are very important for the interpretation of recent transport measurements and can assist in tuning the properties of graphene for practical applications.

Graphene Josephson Junction Single Photon Detector

NASA Astrophysics Data System (ADS)

Walsh, Evan D.; Lee, Gil-Ho; Efetov, Dmitri K.; Heuck, Mikkel; Crossno, Jesse; Taniguchi, Takashi; Watanabe, Kenji; Ohki, Thomas A.; Kim, Philip; Englund, Dirk; Fong, Kin Chung

Single photon detectors (SPDs) have found use across a wide array of applications depending on the wavelength to which they are sensitive. Graphene, because of its linear, gapless dispersion near the Dirac point, has a flat, wide bandwidth absorption that can be enhanced to near 100 % through the use of resonant structures making it a promising candidate for broadband SPDs. Upon absorbing a photon in the optical to mid-infrared range, a small (~10 μm2) sheet of graphene at cryogenic temperatures can experience a significant increase in electronic temperature due to its extremely low heat capacity. At 1550 nm, for example, calculations show that the temperature could rise by as much as 500 %. This temperature increase could be detected with near perfect quantum efficiency by making the graphene the weak link in a Josephson junction (JJ). We present a theoretical model demonstrating that such a graphene JJ SPD could operate at the readily achievable temperature of 3 K with near zero dark count, sub-50 ps timing jitter, and sub-5 ns dead time and report on the progress toward experimentally realizing the device.

Friction and solid-solid adhesion on complex metallic alloys

PubMed Central

Dubois, Jean-Marie; Belin-Ferré, Esther

2014-01-01

The discovery in 1987 of stable quasicrystals in the Al–Cu–Fe system was soon exploited to patent specific coatings that showed reduced friction in ambient air against hard antagonists. Henceforth, it was possible to develop a number of applications, potential or commercially exploited to date, that will be alluded to in this topical review. A deeper understanding of the characteristics of complex metallic alloys (CMAs) may explain why material made of metals like Al, Cu and Fe offers reduced friction; low solid–solid adhesion came later. It is linked to the surface energy being significantly lower on those materials, in which translational symmetry has become a weak property, that is determined by the depth of the pseudo-gap at the Fermi energy. As a result, friction is anisotropic in CMAs that builds up according to the translation symmetry along one direction, but is aperiodic along the other two directions. A review is given in this article of the most salient data found along these lines during the past two decades or so. PMID:27877675

Highly Sensitive Electro-Optic Modulators

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

DeVore, Peter S

2015-10-26

There are very important diagnostic and communication applications that receive faint electrical signals to be transmitted over long distances for capture. Optical links reduce bandwidth and distance restrictions of metal transmission lines; however, such signals are only weakly imprinted onto the optical carrier, resulting in low fidelity transmission. Increasing signal fidelity often necessitates insertion of radio-frequency (RF) amplifiers before the electro-optic modulator, but (especially at high frequencies) RF amplification results in large irreversible distortions. We have investigated the feasibility of a Sensitive and Linear Modulation by Optical Nonlinearity (SALMON) modulator to supersede RF-amplified modulators. SALMON uses cross-phase modulation, a manifestationmore » of the Kerr effect, to enhance the modulation depth of an RF-modulated optical wave. This ultrafast process has the potential to result in less irreversible distortions as compared to a RF-amplified modulator due to the broadband nature of the Kerr effect. Here, we prove that a SALMON modulator is a feasible alternative to an RFamplified modulator, by demonstrating a sensitivity enhancement factor greater than 20 and significantly reduced distortion.« less

A pure magnetite hydrogel: synthesis, properties and possible applications.

PubMed

Anastasova, Elizaveta I; Ivanovski, Vladimir; Fakhardo, Anna F; Lepeshkin, Artem I; Omar, Suheir; Drozdov, Andrey S; Vinogradov, Vladimir V

2017-11-22

A magnetite-only hydrogel was prepared for the first time by weak base mediated gelation of stable magnetite hydrosols at room temperature. The hydrogel consists of 10 nm magnetite nanoparticles linked by interparticle Fe-O-Fe bonds and has the appearance of a dark-brown viscous thixotropic material. The water content in the hydrogel could be up to 93.6% by mass while volume fraction reaches 99%. The material shows excellent biocompatibility and minor cytotoxic effects at concentrations up to 207 μg mL -1 . The gel shows excellent sorption capacity for heavy metal adsorption such as chrome and lead ions, which is 225% more than the adsorption capacity of magnetite nanoparticles. Due to thixotropic nature, the gel demonstrates mechanical stimuli-responsive release behavior with up to 98% release triggered by ultrasound irradiation. The material shows superparamagnetic behavior with a coercivity of 65 emu g -1 at 6000 Oe. The magnetite gels prepared could be used for the production of magnetite aerogels, magnetic drug delivery systems with controlled release and highly efficient sorbents for hydrometallurgy.

The design and fabrication of a Stirling engine heat exchanger module with an integral heat pipe

NASA Technical Reports Server (NTRS)

Schreiber, Jeffrey G.

1988-01-01

The conceptual design of a free-piston Stirling Space Engine (SSE) intended for space power applications has been generated. The engine was designed to produce 25 kW of electric power with heat supplied by a nuclear reactor. A novel heat exchanger module was designed to reduce the number of critical joints in the heat exchanger assembly while also incorporating a heat pipe as the link between the engine and the heat source. Two inexpensive verification tests are proposed. The SSE heat exchanger module is described and the operating conditions for the module are outlined. The design process of the heat exchanger modules, including the sodium heat pipe, is briefly described. Similarities between the proposed SSE heat exchanger modules and the LeRC test modules for two test engines are presented. The benefits and weaknesses of using a sodium heat pipe to transport heat to a Stirling engine are discussed. Similarly, the problems encountered when using a true heat pipe, as opposed to a more simple reflux boiler, are described. The instruments incorporated into the modules and the test program are also outlined.

Effects of moiré lattice structure on electronic properties of graphene

DOE PAGES

Huang, Lunan; Wu, Yun; Hershberger, M. T.; ...

2017-07-10

Here, we study structural and electronic properties of graphene grown on silicone carbide (SiC) substrate using a scanning tunneling microscope, spot-profile-analysis low-energy electron diffraction, and angle-resolved photoemission spectroscopy. We find several new replicas of Dirac cones in the Brillouin zone. Their locations can be understood in terms of a combination of basis vectors linked to SiC 6 × 6 and graphene 6√3×6√3 reconstruction. Therefore, these new features originate from the moiré caused by the lattice mismatch between SiC and graphene. More specifically, Dirac cone replicas are caused by underlying weak modulation of the ionic potential by the substrate that ismore » then experienced by the electrons in the graphene. We also demonstrate that this effect is equally strong in single- and trilayer graphene; therefore, the additional Dirac cones are intrinsic features rather than the result of photoelectron diffraction. These new features in the electronic structure are very important for the interpretation of recent transport measurements and can assist in tuning the properties of graphene for practical applications.« less

Electrocardiogram signal denoising based on empirical mode decomposition technique: an overview

NASA Astrophysics Data System (ADS)

Han, G.; Lin, B.; Xu, Z.

2017-03-01

Electrocardiogram (ECG) signal is nonlinear and non-stationary weak signal which reflects whether the heart is functioning normally or abnormally. ECG signal is susceptible to various kinds of noises such as high/low frequency noises, powerline interference and baseline wander. Hence, the removal of noises from ECG signal becomes a vital link in the ECG signal processing and plays a significant role in the detection and diagnosis of heart diseases. The review will describe the recent developments of ECG signal denoising based on Empirical Mode Decomposition (EMD) technique including high frequency noise removal, powerline interference separation, baseline wander correction, the combining of EMD and Other Methods, EEMD technique. EMD technique is a quite potential and prospective but not perfect method in the application of processing nonlinear and non-stationary signal like ECG signal. The EMD combined with other algorithms is a good solution to improve the performance of noise cancellation. The pros and cons of EMD technique in ECG signal denoising are discussed in detail. Finally, the future work and challenges in ECG signal denoising based on EMD technique are clarified.

Serum resistin correlates with central obesity but weakly with insulin resistance in Chinese children and adolescents.

PubMed

Li, M; Fisette, A; Zhao, X-Y; Deng, J-Y; Mi, J; Cianflone, K

2009-04-01

Resistin has been linked with obesity and hypothesized as a potential marker of insulin resistance in addition to being linked with acute inflammation. However, these links are still highly controversial in humans. Our goal was to examine resistin levels in relation to obesity, insulin resistance and inflammation markers in a large population of Asian children and adolescents. Children and adolescents (n=3472) aged 6-18 years, boys (n=1765) and girls (n=1707), were assessed for body size parameters, pubertal development, blood lipids, glucose, insulin, resistin, C-reactive protein (CRP), adiponectin and complement C3 (C3) levels. Resistin increased with central obesity in both genders but not with simple adiposity in boys. Several markers associated with central obesity correlated in a gender-specific fashion with plasma resistin. Waist circumference, fat-mass percentage, waist-to-height ratio and body mass index (BMI) positively correlated with resistin in both genders. Blood lipids such as triglycerides, nonesterified fatty acids (NEFA) and low-density lipoprotein cholesterol, diastolic and systolic blood pressure correlated positively with resistin in boys. NEFA, high-density lipoprotein cholesterol (negatively) and inflammation markers, such as CRP and C3, positively correlated with resistin in girls. There was no correlation between resistin and adiponectin, and no association of adiponectin with resistin quintiles in either boys or girls. In both boys and girls, resistin tended to decrease with age, with girls having higher levels than boys. Few indices of insulin resistance were linked with plasma resistin in either gender. In this population, plasma resistin levels are a weak biochemical marker of metabolic dysfunction defined by central obesity, adiposity and inflammation and does not predict insulin resistance. Only a small proportion of resistin variation can be explained by factors related to metabolic syndrome, suggesting that resistin is not strongly implicated in a concentration-dependent fashion in any of the examined pathologies.

47 CFR 90.129 - Supplemental information to be routinely submitted with applications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Applications and... communications. (n) All applications for renewal of base/mobile station licenses by licensees who also operate... of frequencies necessary for the link(s); (3) The name and phone number of the person(s) responsible...

Developing and evaluating Quilts for the depiction of large layered graphs.

PubMed

Bae, Juhee; Watson, Ben

2011-12-01

Traditional layered graph depictions such as flow charts are in wide use. Yet as graphs grow more complex, these depictions can become difficult to understand. Quilts are matrix-based depictions for layered graphs designed to address this problem. In this research, we first improve Quilts by developing three design alternatives, and then compare the best of these alternatives to better-known node-link and matrix depictions. A primary weakness in Quilts is their depiction of skip links, links that do not simply connect to a succeeding layer. Therefore in our first study, we compare Quilts using color-only, text-only, and mixed (color and text) skip link depictions, finding that path finding with the color-only depiction is significantly slower and less accurate, and that in certain cases, the mixed depiction offers an advantage over the text-only depiction. In our second study, we compare Quilts using the mixed depiction to node-link diagrams and centered matrices. Overall results show that users can find paths through graphs significantly faster with Quilts (46.6 secs) than with node-link (58.3 secs) or matrix (71.2 secs) diagrams. This speed advantage is still greater in large graphs (e.g. in 200 node graphs, 55.4 secs vs. 71.1 secs for node-link and 84.2 secs for matrix depictions). © 2011 IEEE

Generalized Parameter-Adjusted Stochastic Resonance of Duffing Oscillator and Its Application to Weak-Signal Detection.

PubMed

Lai, Zhi-Hui; Leng, Yong-Gang

2015-08-28

A two-dimensional Duffing oscillator which can produce stochastic resonance (SR) is studied in this paper. We introduce its SR mechanism and present a generalized parameter-adjusted SR (GPASR) model of this oscillator for the necessity of parameter adjustments. The Kramers rate is chosen as the theoretical basis to establish a judgmental function for judging the occurrence of SR in this model; and to analyze and summarize the parameter-adjusted rules under unmatched signal amplitude, frequency, and/or noise-intensity. Furthermore, we propose the weak-signal detection approach based on this GPASR model. Finally, we employ two practical examples to demonstrate the feasibility of the proposed approach in practical engineering application.

Circuit-level simulation of transistor lasers and its application to modelling of microwave photonic links

NASA Astrophysics Data System (ADS)

Iezekiel, Stavros; Christou, Andreas

2015-03-01

Equivalent circuit models of a transistor laser are used to investigate the suitability of this relatively new device for analog microwave photonic links. The three-terminal nature of the device enables transistor-based circuit design techniques to be applied to optoelectronic transmitter design. To this end, we investigate the application of balanced microwave amplifier topologies in order to enable low-noise links to be realized with reduced intermodulation distortion and improved RF impedance matching compared to conventional microwave photonic links.

Laterality and mental disorders in the postgenomic age--A closer look at schizophrenia and language lateralization.

PubMed

Ocklenburg, Sebastian; Güntürkün, Onur; Hugdahl, Kenneth; Hirnstein, Marco

2015-12-01

Most people are right-handed and show left-hemispheric language lateralization, but a minority exhibits left-handedness and right-hemispheric language lateralization. This atypical laterality pattern is observed significantly more often in schizophrenia patients than in the general population, which led several authors to conclude that there is a genetic link between laterality and schizophrenia. It has even been suggested that a failure in the lateralization process, orchestrated by genes, could be the primary cause of schizophrenia. However, the molecular genetic evidence for a link between laterality and schizophrenia is weak. Recent genetic evidence indicates that schizophrenia is not a single disorder but a group of heritable disorders caused by different genotypic networks leading to distinct clinical symptoms. To uncover the link between schizophrenia and laterality we therefore suggest a paradigm shift where genetics are not mapped on schizophrenia as a whole but on discrete schizophrenia symptoms. In addition, we provide a critical evaluation of current theories on the genetic link between schizophrenia and brain asymmetry. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mutations in cadherin 23 affect tip links in zebrafish sensory hair cells.

PubMed

Söllner, Christian; Rauch, Gerd-Jörg; Siemens, Jan; Geisler, Robert; Schuster, Stephan C; Müller, Ulrich; Nicolson, Teresa

2004-04-29

Hair cells have highly organized bundles of apical projections, or stereocilia, that are deflected by sound and movement. Displacement of stereocilia stretches linkages at the tips of stereocilia that are thought to gate mechanosensory channels. To identify the molecular machinery that mediates mechanotransduction in hair cells, zebrafish mutants were identified with defects in balance and hearing. In sputnik mutants, stereociliary bundles are splayed to various degrees, with individuals displaying reduced or absent mechanotransduction. Here we show that the defects in sputnik mutants are caused by mutations in cadherin 23 (cdh23). Mutations in Cdh23 also cause deafness and vestibular defects in mice and humans, and the protein is present in hair bundles. We show that zebrafish Cdh23 protein is concentrated near the tips of hair bundles, and that tip links are absent in homozygous sputnik(tc317e) larvae. Moreover, tip links are absent in larvae carrying weak alleles of cdh23 that affect mechanotransduction but not hair bundle integrity. We conclude that Cdh23 is an essential tip link component required for hair-cell mechanotransduction.

Tension-induced binding of semiflexible biopolymers

NASA Astrophysics Data System (ADS)

Benetatos, Panayotis; von der Heydt, Alice; Zippelius, Annette

2015-03-01

We investigate theoretically the effect of polymer tension on the collective behaviour of reversible cross-links. We use a model of two parallel-aligned, weakly-bending wormlike chains with a regularly spaced sequence of binding sites subjected to a tensile force. Reversible cross-links attach and detach at the binding sites with an affinity controlled by a chemical potential. In a mean-field approach, we calculate the free energy of the system and we show the emergence of a free energy barrier which controls the reversible (un)binding. The tension affects the conformational entropy of the chains which competes with the binding energy of the cross-links. This competition gives rise to a sudden increase in the fraction of bound sites as the polymer tension increases. The force-induced first-order transition in the number of cross-links implies a sudden force-induced stiffening of the effective stretching modulus of the polymers. This mechanism may be relevant to the formation and stress-induced strengthening of stress fibers in the cytoskeleton. We acknowledge support by the Deutsche Forschungsgemeinschaft (DFG) via grant SFB-937/A1.

The ideal of equal health revisited: definitions and measures of inequity in health should be better integrated with theories of distributive justice

PubMed Central

2009-01-01

The past decade witnessed great progress in research on health inequities. The most widely cited definition of health inequity is, arguably, the one proposed by Whitehead and Dahlgren: "Health inequalities that are avoidable, unnecessary, and unfair are unjust." We argue that this definition is useful but in need of further clarification because it is not linked to broader theories of justice. We propose an alternative, pluralist notion of fair distribution of health that is compatible with several theories of distributive justice. Our proposed view consists of the weak principle of health equality and the principle of fair trade-offs. The weak principle of health equality offers an alternative definition of health equity to those proposed in the past. It maintains the all-encompassing nature of the popular Whitehead/Dahlgren definition of health equity, and at the same time offers a richer philosophical foundation. This principle states that every person or group should have equal health except when: (a) health equality is only possible by making someone less healthy, or (b) there are technological limitations on further health improvement. In short, health inequalities that are amenable to positive human intervention are unfair. The principle of fair trade-offs states that weak equality of health is morally objectionable if and only if: (c) further reduction of weak inequality leads to unacceptable sacrifices of average or overall health of the population, or (d) further reduction in weak health inequality would result in unacceptable sacrifices of other important goods, such as education, employment, and social security. PMID:19922612

Advances in artificial olfaction: sensors and applications.

PubMed

Gutiérrez, J; Horrillo, M C

2014-06-01

The artificial olfaction, based on electronic systems (electronic noses), includes three basic functions that operate on an odorant: a sample handler, an array of gas sensors, and a signal-processing method. The response of these artificial systems can be the identity of the odorant, an estimate concentration of the odorant, or characteristic properties of the odour as might be perceived by a human. These electronic noses are bio inspired instruments that mimic the sense of smell. The complexity of most odorants makes characterisation difficult with conventional analysis techniques, such as gas chromatography. Sensory analysis by a panel of experts is a costly process since it requires trained people who can work for only relatively short periods of time. The electronic noses are easy to build, provide short analysis times, in real time and on-line, and show high sensitivity and selectivity to the tested odorants. These systems are non-destructive techniques used to characterise odorants in diverse applications linked with the quality of life such as: control of foods, environmental quality, citizen security or clinical diagnostics. However, there is much research still to be done especially with regard to new materials and sensors technology, data processing, interpretation and validation of results. This work examines the main features of modern electronic noses and their most important applications in the environmental, and security fields. The above mentioned main components of an electronic nose (sample handling system, more advanced materials and methods for sensing, and data processing system) are described. Finally, some interesting remarks concerning the strengths and weaknesses of electronic noses in the different applications are also mentioned. Copyright © 2014 Elsevier B.V. All rights reserved.

The Identification of Filters and Interdependencies for Effective Resource Allocation: Coupling the Mitigation of Natural Hazards to Economic Development.

NASA Astrophysics Data System (ADS)

Agar, S. M.; Kunreuther, H.

2005-12-01

Policy formulation for the mitigation and management of risks posed by natural hazards requires that governments confront difficult decisions for resource allocation and be able to justify their spending. Governments also need to recognize when spending offers little improvement and the circumstances in which relatively small amounts of spending can make substantial differences. Because natural hazards can have detrimental impacts on local and regional economies, patterns of economic development can also be affected by spending decisions for disaster mitigation. This paper argues that by mapping interdependencies among physical, social and economic factors, governments can improve resource allocation to mitigate the risks of natural hazards while improving economic development on local and regional scales. Case studies of natural hazards in Turkey have been used to explore specific "filters" that act to modify short- and long-term outcomes. Pre-event filters can prevent an event from becoming a natural disaster or change a routine event into a disaster. Post-event filters affect both short and long-term recovery and development. Some filters cannot be easily modified by spending (e.g., rural-urban migration) but others (e.g., land-use practices) provide realistic spending targets. Net social benefits derived from spending, however, will also depend on the ways by which filters are linked, or so-called "interdependencies". A single weak link in an interdependent system, such as a power grid, can trigger a cascade of failures. Similarly, weak links in social and commercial networks can send waves of disruption through communities. Conversely, by understanding the positive impacts of interdependencies, spending can be targeted to maximize net social benefits while mitigating risks and improving economic development. Detailed information on public spending was not available for this study but case studies illustrate how networks of interdependent filters can modify social benefits and costs. For example, spending after the 1992 Erzincan earthquake targeted local businesses but limited alternative employment, labor losses and diminished local markets all contributed to economic stagnation. Spending after the 1995 Dinar earthquake provided rent subsidies, supporting a major exodus from the town. Consequently many local people were excluded from reconstruction decisions and benefits offered by reconstruction funds. After the 1999 Marmara earthquakes, a 3-year economic decline in Yalova illustrates the vulnerability of local economic stability to weak regulation enforcement by a few agents. A resource allocation framework indicates that government-community relations, lack of economic diversification, beliefs, and compensation are weak links for effective spending. Stronger positive benefits could be achieved through spending to target land-use regulation enforcement, labor losses, time-critical needs of small businesses, and infrastructure. While the impacts of the Marmara earthquakes were devastating, strong commercial networks and international interests helped to re-establish the regional economy. Interdependencies may have helped to drive a recovery. Smaller events in eastern Turkey, however, can wipe out entire communities and can have long-lasting impacts on economic development. These differences may accelerate rural to urban migration and perpetuate regional economic divergence in the country. 1: Research performed in the Wharton MBA Program, Univ. of Pennsylvania.

Entropy criteria applied to pattern selection in systems with free boundaries

NASA Astrophysics Data System (ADS)

Kirkaldy, J. S.

1985-10-01

The steady state differential or integral equations which describe patterned dissipative structures, typically to be identified with first order phase transformation morphologies like isothermal pearlites, are invariably degenerate in one or more order parameters (the lamellar spacing in the pearlite case). It is often observed that a different pattern is attained at the steady state for each initial condition (the hysteresis or metastable case). Alternatively, boundary perturbations and internal fluctuations during transition up to, or at the steady state, destroy the path coherence. In this case a statistical ensemble of imperfect patterns often emerges which represents a fluctuating but recognizably patterned and unique average steady state. It is cases like cellular, lamellar pearlite, involving an assembly of individual cell patterns which are regularly perturbed by local fluctuation and growth processes, which concern us here. Such weakly fluctuating nonlinear steady state ensembles can be arranged in a thought experiment so as to evolve as subsystems linking two very large mass-energy reservoirs in isolation. Operating on this discontinuous thermodynamic ideal, Onsager’s principle of maximum path probability for isolated systems, which we interpret as a minimal time correlation function connecting subsystem and baths, identifies the stable steady state at a parametric minimum or maximum (or both) in the dissipation rate. This nonlinear principle is independent of the Principle of Minimum Dissipation which is applicable in the linear regime of irreversible thermodynamics. The statistical argument is equivalent to the weak requirement that the isolated system entropy as a function of time be differentiable to the second order despite the macroscopic pattern fluctuations which occur in the subsystem. This differentiability condition is taken for granted in classical stability theory based on the 2nd Law. The optimal principle as applied to isothermal and forced velocity pearlites (in this case maximal) possesses a Le Chatelier (perturbation) Principle which can be formulated exactly via Langer’s conjecture that “each lamella must grow in a direction which is perpendicular to the solidification front”. This is the first example of such an equivalence to be experimentally and theoretically recognized in nonlinear irreversible thermodynamics. A further application to binary solidification cells is reviewed. In this case the optimum in the dissipation is a minimum and the closure between theory and experiment is excellent. Other applications in thermal-hydraulics, biology, and solid state physics are briefy described.

SNAP Assay Technology.

PubMed

O'Connor, Thomas P

2015-12-01

The most widely used immunoassay configuration is the enzyme-linked immunosorbent assay (ELISA) because the procedure produces highly sensitive and specific results and generally is easy to use. By definition, ELISAs are immunoassays used to detect a substance (typically an antigen or antibody) in which an enzyme is attached (conjugated) to one of the reactants and an enzymatic reaction is used to amplify the signal if the substance is present. Optimized ELISAs include several steps that are performed in sequence using a defined protocol that typically includes application of sample and an enzyme-conjugated antibody or antigen to an immobilized reagent, followed by wash and enzyme reaction steps. The SNAP assay is an in-clinic device that performs each of the ELISA steps in a timed sequential fashion with little consumer interface. The components and mechanical mechanism of the assay device are described. Detailed descriptions of features of the assay, which minimize nonspecific binding and enhance the ability to read results from weak-positive samples, are given. Basic principles used in assays with fundamentally different reaction mechanisms, namely, antigen-detection, antibody-detection, and competitive assays are given. Applications of ELISA technology, which led to the development of several multianalyte SNAP tests capable of testing for up to 6 analytes using a single-sample and a single-SNAP device are described. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Long-range Coulomb forces and localized bonds.

PubMed

Preiser; Lösel; Brown; Kunz; Skowron

1999-10-01

The ionic model is shown to be applicable to all compounds in which the atoms carry a net charge and their electron density is spherically symmetric regardless of the covalent character of the bonding. By examining the electric field generated by an array of point charges placed at the positions of the ions in over 40 inorganic compounds, we show that the Coulomb field naturally partitions itself into localized regions (bonds) which are characterized by the electric flux that links neighbouring ions of opposite charge. This flux is identified with the bond valence, and Gauss' law with the valence-sum rule, providing a secure theoretical foundation for the bond-valence model. The localization of the Coulomb field provides an unambiguous definition of coordination number and our calculations show that, in addition to the expected primary coordination sphere, there are a number of weak bonds between cations and the anions in the second coordination sphere. Long-range Coulomb interactions are transmitted through the crystal by the application of Gauss' law at each of the intermediate atoms. Bond fluxes have also been calculated for compounds containing ions with non-spherical electron densities (e.g. cations with stereoactive lone electron pairs). In these cases the point-charge model continues to describe the distant field, but multipoles must be added to the point charges to give the correct local field.

Innovative Legal Approaches to Address Obesity

PubMed Central

Pomeranz, Jennifer L; Teret, Stephen P; Sugarman, Stephen D; Rutkow, Lainie; Brownell, Kelly D

2009-01-01

Context: The law is a powerful public health tool with considerable potential to address the obesity issue. Scientific advances, gaps in the current regulatory environment, and new ways of conceptualizing rights and responsibilities offer a foundation for legal innovation. Methods: This article connects developments in public health and nutrition with legal advances to define promising avenues for preventing obesity through the application of the law. Findings: Two sets of approaches are defined: (1) direct application of the law to factors known to contribute to obesity and (2) original and innovative legal solutions that address the weak regulatory stance of government and the ineffectiveness of existing policies used to control obesity. Specific legal strategies are discussed for limiting children's food marketing, confronting the potential addictive properties of food, compelling industry speech, increasing government speech, regulating conduct, using tort litigation, applying nuisance law as a litigation strategy, and considering performance-based regulation as an alternative to typical regulatory actions. Finally, preemption is an overriding issue and can play both a facilitative and a hindering role in obesity policy. Conclusions: Legal solutions are immediately available to the government to address obesity and should be considered at the federal, state, and local levels. New and innovative legal solutions represent opportunities to take the law in creative directions and to link legal, nutrition, and public health communities in constructive ways. PMID:19298420

Designing and defining dynamic protein cage nanoassemblies in solution

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

Lai, Y. -T.; Hura, G. L.; Dyer, K. N.

Central challenges in the design of large and dynamic macromolecular assemblies for synthetic biology lie in developing effective methods for testing design strategies and their outcomes, including comprehensive assessments of solution behavior. Here, we created and validated an advanced design of a 600-kDa protein homododecamer that self-assembles into a symmetric tetrahedral cage. The monomeric unit is composed of a trimerizing apex-forming domain genetically linked to an edge-forming dimerizing domain. Enhancing the crystallographic results, high-throughput small-angle x-ray scattering (SAXS) comprehensively contrasted our modifications under diverse solution conditions. To generate a phase diagram associating structure and assembly, we developed force plots thatmore » measure dissimilarity among multiple SAXS data sets. These new tools, which provided effective feedback on experimental constructs relative to design, have general applicability in analyzing the solution behavior of heterogeneous nanosystems and have been made available as a web-based application. Specifically, our results probed the influence of solution conditions and symmetry on stability and structural adaptability, identifying the dimeric interface as the weak point in the assembly. Force plots comparing SAXS data sets further reveal more complex and controllable behavior in solution than captured by our crystal structures. Lastly, these methods for objectively and comprehensively comparing SAXS profiles for systems critically affected by solvent conditions and structural heterogeneity provide an enabling technology for advancing the design and bioengineering of nanoscale biological materials.« less

Designing and defining dynamic protein cage nanoassemblies in solution

DOE PAGES

Lai, Y. -T.; Hura, G. L.; Dyer, K. N.; ...

2016-12-14

Central challenges in the design of large and dynamic macromolecular assemblies for synthetic biology lie in developing effective methods for testing design strategies and their outcomes, including comprehensive assessments of solution behavior. Here, we created and validated an advanced design of a 600-kDa protein homododecamer that self-assembles into a symmetric tetrahedral cage. The monomeric unit is composed of a trimerizing apex-forming domain genetically linked to an edge-forming dimerizing domain. Enhancing the crystallographic results, high-throughput small-angle x-ray scattering (SAXS) comprehensively contrasted our modifications under diverse solution conditions. To generate a phase diagram associating structure and assembly, we developed force plots thatmore » measure dissimilarity among multiple SAXS data sets. These new tools, which provided effective feedback on experimental constructs relative to design, have general applicability in analyzing the solution behavior of heterogeneous nanosystems and have been made available as a web-based application. Specifically, our results probed the influence of solution conditions and symmetry on stability and structural adaptability, identifying the dimeric interface as the weak point in the assembly. Force plots comparing SAXS data sets further reveal more complex and controllable behavior in solution than captured by our crystal structures. Lastly, these methods for objectively and comprehensively comparing SAXS profiles for systems critically affected by solvent conditions and structural heterogeneity provide an enabling technology for advancing the design and bioengineering of nanoscale biological materials.« less

The interplay of fold mechanisms and basement weaknesses at the transition between Laramide basement-involved arches, north-central Wyoming, USA

NASA Astrophysics Data System (ADS)

Neely, Thomas G.; Erslev, Eric A.

2009-09-01

Horizontally-shortened, basement-involved foreland orogens commonly exhibit anastomosing networks of bifurcating basement highs (here called arches) whose structural culminations are linked by complex transition zones of diversely-oriented faults and folds. The 3D geometry and kinematics of the southern Beartooth arch transition zone of north-central Wyoming were studied to understand the fold mechanisms and control on basement-involved arches. Data from 1581 slickensided minor faults are consistent with a single regional shortening direction of 065°. Evidence for oblique-slip, vertical axis rotations and stress refraction at anomalously-oriented folds suggests formation over reactivated pre-existing weaknesses. Restorable cross-sections and 3D surfaces, constrained by surface, well, and seismic data, document blind, ENE-directed basement thrusting and associated thin-skinned backthrusting and folding along the Beartooth and Oregon Basin fault systems. Between these systems, the basement-cored Rattlesnake Mountain backthrust followed basement weaknesses and rotated a basement chip toward the basin before the ENE-directed Line Creek fault system broke through and connected the Beartooth and Oregon Basin fault systems. Slip was transferred at the terminations of the Rattlesnake Mountain fault block by pivoting to the north and tear faulting to the south. In summary, unidirectional Laramide compression and pre-existing basement weaknesses combined with fault-propagation and rotational fault-bend folding to create an irregular yet continuous basement arch transition.

Impaired control of weight bearing ankle inversion in subjects with chronic ankle instability.

PubMed

Terrier, R; Rose-Dulcina, K; Toschi, B; Forestier, N

2014-04-01

Previous studies have proposed that evertor muscle weakness represents an important factor affecting chronic ankle instability. For research purposes, ankle evertor strength is assessed by means of isokinetic evaluations. However, this methodology is constraining for daily clinical use. The present study proposes to assess ankle evertor muscle weakness using a new procedure, one that is easily accessible for rehabilitation specialists. To do so, we compared weight bearing ankle inversion control between patients suffering from chronic ankle instability and healthy subjects. 12 healthy subjects and 11 patients suffering from chronic ankle instability conducted repetitions of one leg weight bearing ankle inversion on a specific ankle destabilization device equipped with a gyroscope. Ankle inversion control was performed by means of an eccentric recruitment of evertor muscles. Instructions were to perform, as slow as possible, the ankle inversion while resisting against full body weight applied on the tested ankle. Data clearly showed higher angular inversion velocity peaks in patients suffering from chronic ankle instability. This illustrates an impaired control of weight bearing ankle inversion and, by extension, an eccentric weakness of evertor muscles. The present study supports the hypothesis of a link between the decrease of ankle joint stability and evertor muscle weakness. Moreover, it appears that the new parameter is of use in a clinical setting. Copyright © 2014 Elsevier Ltd. All rights reserved.

The zero age main sequence of WIMP burners

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

Fairbairn, Malcolm; Scott, Pat; Edsjoe, Joakim

2008-02-15

We modify a stellar structure code to estimate the effect upon the main sequence of the accretion of weakly-interacting dark matter onto stars and its subsequent annihilation. The effect upon the stars depends upon whether the energy generation rate from dark matter annihilation is large enough to shut off the nuclear burning in the star. Main sequence weakly-interacting massive particles (WIMP) burners look much like proto-stars moving on the Hayashi track, although they are in principle completely stable. We make some brief comments about where such stars could be found, how they might be observed and more detailed simulations whichmore » are currently in progress. Finally we comment on whether or not it is possible to link the paradoxically hot, young stars found at the galactic center with WIMP burners.« less

Event schemas in autism spectrum disorders: the role of theory of mind and weak central coherence.

PubMed

Loth, Eva; Gómez, Juan Carlos; Happé, Francesca

2008-03-01

Event schemas (generalized knowledge of what happens at common real-life events, e.g., a birthday party) are an important cognitive tool for social understanding: They provide structure for social experiences while accounting for many variable aspects. Using an event narratives task, this study tested the hypotheses that theory of mind (ToM) deficits and weak central coherence (WCC, a local processing bias) undermine different aspects of event knowledge in people with autism spectrum disorder (ASD). Event narratives of ASD ToM-failers were overall significantly impaired. ASD ToM-passers showed more specific abnormalities relating to variable activities, and some of these were significantly associated to WCC. Abnormalities in event knowledge might help linking ASD-typical social deficits in real-life situations and the adherence to inflexible routines.

(E)-1,2-Bis(4-methyl­phen­yl)ethane-1,2-dione

PubMed Central

Fun, Hoong-Kun; Kia, Reza

2008-01-01

In the mol­ecule of the title compound, C16H14O2, a substituted benzil, the dicarbonyl unit has an s-trans conformation. This conformation is substanti­ated by the O—C—C—O torsion angle of 108.16 (15)°. The dihedral angle between the two aromatic rings is 72.00 (6)°. In the crystal structure, neighbouring mol­ecules are linked together by weak inter­molecular C—H⋯O hydrogen bonds and weak inter­molecular C—H⋯π inter­actions. In addition, the crystal structure is further stabilized by inter­molecular π–π inter­actions with centroid–centroid distances in the range 3.6000 (8)–3.8341 (8) Å. PMID:21203307

Proximity-Induced Superconductivity and Quantum Interference in Topological Crystalline Insulator SnTe Thin-Film Devices.

PubMed

Klett, Robin; Schönle, Joachim; Becker, Andreas; Dyck, Denis; Borisov, Kiril; Rott, Karsten; Ramermann, Daniela; Büker, Björn; Haskenhoff, Jan; Krieft, Jan; Hübner, Torsten; Reimer, Oliver; Shekhar, Chandra; Schmalhorst, Jan-Michael; Hütten, Andreas; Felser, Claudia; Wernsdorfer, Wolfgang; Reiss, Günter

2018-02-14

Topological crystalline insulators represent a new state of matter, in which the electronic transport is governed by mirror-symmetry protected Dirac surface states. Due to the helical spin-polarization of these surface states, the proximity of topological crystalline matter to a nearby superconductor is predicted to induce unconventional superconductivity and, thus, to host Majorana physics. We report on the preparation and characterization of Nb-based superconducting quantum interference devices patterned on top of topological crystalline insulator SnTe thin films. The SnTe films show weak anti-localization, and the weak links of the superconducting quantum interference devices (SQUID) exhibit fully gapped proximity-induced superconductivity. Both properties give a coinciding coherence length of 120 nm. The SQUID oscillations induced by a magnetic field show 2π periodicity, possibly dominated by the bulk conductivity.

Identifying economics' place amongst academic disciplines: a science or a social science?

PubMed

Hudson, John

2017-01-01

Different academic disciplines exhibit different styles, including styles in journal titles. Using data from the 2014 Research Excellence Framework (REF) in the UK we are able to identify the stylistic trends of different disciplines using 155,552 journal titles across all disciplines. Cluster analysis is then used to group the different disciplines together. The resulting identification fits the social sciences, the sciences and the arts and humanities reasonably well. Economics overall, fits best with philosophy, but the linkage is weak. When we divided economics into papers published in theory, econometrics and the remaining journals, the first two link with mathematics and computer science, particularly econometrics, and thence the sciences. The rest of economics then links with business and thence the social sciences.

Robustness of assembly supply chain networks by considering risk propagation and cascading failure

NASA Astrophysics Data System (ADS)

Tang, Liang; Jing, Ke; He, Jie; Stanley, H. Eugene

2016-10-01

An assembly supply chain network (ASCN) is composed of manufacturers located in different geographical regions. To analyze the robustness of this ASCN when it suffers from catastrophe disruption events, we construct a cascading failure model of risk propagation. In our model, different disruption scenarios s are considered and the probability equation of all disruption scenarios is developed. Using production capability loss as the robustness index (RI) of an ASCN, we conduct a numerical simulation to assess its robustness. Through simulation, we compare the network robustness at different values of linking intensity and node threshold and find that weak linking intensity or high node threshold increases the robustness of the ASCN. We also compare network robustness levels under different disruption scenarios.

On weak lensing shape noise

NASA Astrophysics Data System (ADS)

Niemi, Sami-Matias; Kitching, Thomas D.; Cropper, Mark

2015-12-01

One of the most powerful techniques to study the dark sector of the Universe is weak gravitational lensing. In practice, to infer the reduced shear, weak lensing measures galaxy shapes, which are the consequence of both the intrinsic ellipticity of the sources and of the integrated gravitational lensing effect along the line of sight. Hence, a very large number of galaxies is required in order to average over their individual properties and to isolate the weak lensing cosmic shear signal. If this `shape noise' can be reduced, significant advances in the power of a weak lensing surveys can be expected. This paper describes a general method for extracting the probability distributions of parameters from catalogues of data using Voronoi cells, which has several applications, and has synergies with Bayesian hierarchical modelling approaches. This allows us to construct a probability distribution for the variance of the intrinsic ellipticity as a function of galaxy property using only photometric data, allowing a reduction of shape noise. As a proof of concept the method is applied to the CFHTLenS survey data. We use this approach to investigate trends of galaxy properties in the data and apply this to the case of weak lensing power spectra.

Dynamical transition between weak and strong coupling in Brillouin laser pulse amplification

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

Schluck, F.; Lehmann, G.; Müller, C.

Short laser pulse amplification via stimulated Brillouin backscattering in plasma is considered. Previous work distinguishes between the weakly and strongly coupled regime and treats them separately. It is shown here that such a separation is not generally applicable because strong and weak coupling interaction regimes are entwined with each other. An initially weakly coupled amplification scenario may dynamically transform into strong coupling. This happens when the local seed amplitude grows and thus triggers the strongly driven plasma response. On the other hand, when in a strong coupling scenario, the pump pulse gets depleted, and its amplitude might drop below themore » strong coupling threshold. This may cause significant changes in the final seed pulse shape. Furthermore, experimentally used pump pulses are typically Gaussian-shaped. The intensity threshold for strong coupling may only be exceeded around the maximum and not in the wings of the pulse. Also here, a description valid in both strong and weak coupling regimes is required. We propose such a unified treatment which allows us, in particular, to study the dynamic transition between weak and strong coupling. Consequences for the pulse forms of the amplified seed are discussed.« less

Remodeling of legacy systems in health care using UML.

PubMed

Garde, Sebastian; Knaup, Petra; Herold, Ralf

2002-01-01

Research projects in the field of Medical Informatics often involve the development of application systems. Usually they are developed over a longer period of time, so that at a certain point of time a systematically planned reimplementation is necessary. The first step of reimplementation should be a systematic and comprehensive remodeling. When using UML for this task a systematic approach for remodeling activities is missing. Therefore, we developed a method for remodeling of legacy systems (Qumquad) and applied it to DOSPO, a documentation and therapy planning system for pediatric oncology. Qumquad helps to systematically carry out three steps: the modeling of the current actual state of the application system, the systematic identification of weak points and the development of a target concept for reimplementation considering the identified weak points. Results show that this approach is valuable and feasible and could be applied to various application systems in health care.

Multipurpose broadcast data link architecture

DOT National Transportation Integrated Search

2000-04-07

The aviation community has recently expressed significant interest in a broadcast mode of data link services. A broadcast mode of delivery is well suited for applications of a general interest to many users and for applications that require periodic ...

[The realization way and lean management about medical consumable material in clinical use].

PubMed

Shang, Changhao; Cheng, Junpei; Xu, Hailin; Wang, Xiaoguang

2015-01-01

The medical consumable material management is an important part of logistic support in the management of hospital, but the hospital has many weak links in the management of supplies. This paper aims to explore the common problems (especially in clinical use) existing in the management of medical consumables and years of management experience in Changhai hospital's practice, then discusses lean management from the perspective of lean management

Advance Care Planning: Experience of Women With Breast Cancer

DTIC Science & Technology

2006-07-01

Dry mouth 402 781 1,183...shortness of breathcough weakness insomnia urinary frequency dry mouth pain fatigue vomiting -5 -4.5 -4 -3.5 -3 -2.5 -2 -1.5 -1 -0.5 0 Most Prevalent Least Prevalent Figure 2. Symptom prevalences according to the unconditional model. ...comorbidity. A previous study of 872 cancer patients admitted to ICU found that completion rates of advance directives were linked to stage and site

4-Benzyl-4-ethyl­morpholin-1-ium hexa­fluoro­phosphate

PubMed Central

Yang, Fang; Zang, Hongjun; Cheng, Bowen; Xu, Xianlin; Ren, Yuanlin

2012-01-01

The asymmetric unit of the title compound, C13H20NO+·PF6 −, contains two cations, one complete anion and two half hexa­fluoro­phosphate anions having crystallographically imposed twofold rotation symmetry. In the cations, the morpholine rings are in a chair conformation. In the crystal, ions are linked by weak C—H⋯F hydrogen bonds into a three-dimensional network. PMID:22412701

Lexical Link Analysis Application: Improving Web Service to Acquisition Visibility Portal Phase II

DTIC Science & Technology

2014-04-30

bäÉîÉåíÜ=^ååì~ä=^Åèìáëáíáçå= oÉëÉ~êÅÜ=póãéçëáìã= qÜìêëÇ~ó=pÉëëáçåë= sçäìãÉ=ff= = Lexical Link Analysis Application: Improving Web Service to...DATE 30 APR 2014 2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Lexical Link Analysis Application: Improving...vocabulary or lexicon, to describe the attributes and surrounding environment of the system. Lexical Link Analysis (LLA) is a form of text mining in which

RAINLINK: Retrieval algorithm for rainfall monitoring employing microwave links from a cellular communication network

NASA Astrophysics Data System (ADS)

Uijlenhoet, R.; Overeem, A.; Leijnse, H.; Rios Gaona, M. F.

2017-12-01

The basic principle of rainfall estimation using microwave links is as follows. Rainfall attenuates the electromagnetic signals transmitted from one telephone tower to another. By measuring the received power at one end of a microwave link as a function of time, the path-integrated attenuation due to rainfall can be calculated, which can be converted to average rainfall intensities over the length of a link. Microwave links from cellular communication networks have been proposed as a promising new rainfall measurement technique for one decade. They are particularly interesting for those countries where few surface rainfall observations are available. Yet to date no operational (real-time) link-based rainfall products are available. To advance the process towards operational application and upscaling of this technique, there is a need for freely available, user-friendly computer code for microwave link data processing and rainfall mapping. Such software is now available as R package "RAINLINK" on GitHub (https://github.com/overeem11/RAINLINK). It contains a working example to compute link-based 15-min rainfall maps for the entire surface area of The Netherlands for 40 hours from real microwave link data. This is a working example using actual data from an extensive network of commercial microwave links, for the first time, which will allow users to test their own algorithms and compare their results with ours. The package consists of modular functions, which facilitates running only part of the algorithm. The main processings steps are: 1) Preprocessing of link data (initial quality and consistency checks); 2) Wet-dry classification using link data; 3) Reference signal determination; 4) Removal of outliers ; 5) Correction of received signal powers; 6) Computation of mean path-averaged rainfall intensities; 7) Interpolation of rainfall intensities ; 8) Rainfall map visualisation. Some applications of RAINLINK will be shown based on microwave link data from a temperate climate (the Netherlands), and from a subtropical climate (Brazil). We hope that RAINLINK will promote the application of rainfall monitoring using microwave links in poorly gauged regions around the world. We invite researchers to contribute to RAINLINK to make the code more generally applicable to data from different networks and climates.

Adaptive Response and Tolerance to Weak Acids in Saccharomyces cerevisiae: A Genome-Wide View

PubMed Central

Mira, Nuno P.; Teixeira, Miguel Cacho

2010-01-01

Abstract Weak acids are widely used as food preservatives (e.g., acetic, propionic, benzoic, and sorbic acids), herbicides (e.g., 2,4-dichlorophenoxyacetic acid), and as antimalarial (e.g., artesunic and artemisinic acids), anticancer (e.g., artesunic acid), and immunosuppressive (e.g., mycophenolic acid) drugs, among other possible applications. The understanding of the mechanisms underlying the adaptive response and resistance to these weak acids is a prerequisite to develop more effective strategies to control spoilage yeasts, and the emergence of resistant weeds, drug resistant parasites or cancer cells. Furthermore, the identification of toxicity mechanisms and resistance determinants to weak acid-based pharmaceuticals increases current knowledge on their cytotoxic effects and may lead to the identification of new drug targets. This review integrates current knowledge on the mechanisms of toxicity and tolerance to weak acid stress obtained in the model eukaryote Saccharomyces cerevisiae using genome-wide approaches and more detailed gene-by-gene analysis. The major features of the yeast response to weak acids in general, and the more specific responses and resistance mechanisms towards a specific weak acid or a group of weak acids, depending on the chemical nature of the side chain R group (R-COOH), are highlighted. The involvement of several transcriptional regulatory networks in the genomic response to different weak acids is discussed, focusing on the regulatory pathways controlled by the transcription factors Msn2p/Msn4p, War1p, Haa1p, Rim101p, and Pdr1p/Pdr3p, which are known to orchestrate weak acid stress response in yeast. The extrapolation of the knowledge gathered in yeast to other eukaryotes is also attempted. PMID:20955006

Structural elucidation of polysaccharide fractions from the brown alga Coccophora langsdorfii and in vitro investigation of their anticancer activity.

PubMed

Imbs, Tatiana I; Ermakova, Svetlana P; Malyarenko Vishchuk, Olesya S; Isakov, Vladimir V; Zvyagintseva, Tatiana N

2016-01-01

Laminaran, fucoidan, and alginate were isolated from the brown alga Coccophora langsdorfii collected in the Japan Sea. The structural characteristics of polysaccharides were investigated by NMR spectroscopy. The laminaran was determined as β-d-glucan, which consisted of 80% of 1,3- and 20% of 1,6-linked residues and was terminated with mannitol. The alginate was a guluronic acid-rich polysaccharide (M/G=0.85). Fucoidan, sulfated α-l-fucan, contained a linear backbone of alternating (1→3)- and (1→4)- linked α-l-fucopyranose residues with sulfate at C2 and C4 of (1→3)-α-l-fucopyranose residues. Anticancer activity of this fucoidan was investigated in comparison with activity of fucoidan having similar linear backbone from the brown alga Fucus evanescens. The fucoidan from C. langsdorfii significantly inhibited colony formation of SK-MEL-5 and SK-MEL-28 melanoma cells (the percentage of inhibition was 28 and 76, respectively) and weakly inhibited colony formation of breast adenocarcinoma cells MDA-MB-231 (the percentage of inhibition was about 5). Similar results were obtained for fucoidan from F. evanescens; the percentage of inhibition of colony formation of SK-MEL-5 and SK-MEL-28 melanoma cells was 54 and 56, respectively. The inhibition of colony formation of breast adenocarcinoma cells MDA-MB-231 was weak. We suppose that other sulfated and partially acetylated fucoidans consisting of (1→3)- and (1→4)-linked α-l-fucopyranose residues may suppress progression of melanoma cell colony formation similar to fucoidans of C. langsdorfii and F. evanescens. Copyright © 2015 Elsevier Ltd. All rights reserved.

Probability of loss of assured safety in temperature dependent systems with multiple weak and strong links.

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

Johnson, Jay Dean; Oberkampf, William Louis; Helton, Jon Craig

2004-12-01

Relationships to determine the probability that a weak link (WL)/strong link (SL) safety system will fail to function as intended in a fire environment are investigated. In the systems under study, failure of the WL system before failure of the SL system is intended to render the overall system inoperational and thus prevent the possible occurrence of accidents with potentially serious consequences. Formal developments of the probability that the WL system fails to deactivate the overall system before failure of the SL system (i.e., the probability of loss of assured safety, PLOAS) are presented for several WWSL configurations: (i) onemore » WL, one SL, (ii) multiple WLs, multiple SLs with failure of any SL before any WL constituting failure of the safety system, (iii) multiple WLs, multiple SLs with failure of all SLs before any WL constituting failure of the safety system, and (iv) multiple WLs, multiple SLs and multiple sublinks in each SL with failure of any sublink constituting failure of the associated SL and failure of all SLs before failure of any WL constituting failure of the safety system. The indicated probabilities derive from time-dependent temperatures in the WL/SL system and variability (i.e., aleatory uncertainty) in the temperatures at which the individual components of this system fail and are formally defined as multidimensional integrals. Numerical procedures based on quadrature (i.e., trapezoidal rule, Simpson's rule) and also on Monte Carlo techniques (i.e., simple random sampling, importance sampling) are described and illustrated for the evaluation of these integrals. Example uncertainty and sensitivity analyses for PLOAS involving the representation of uncertainty (i.e., epistemic uncertainty) with probability theory and also with evidence theory are presented.« less

Targeting cancer’s weaknesses (not its strengths): Therapeutic strategies suggested by the atavistic model

PubMed Central

Lineweaver, Charles H.; Davies, Paul C.W.; Vincent, Mark D.

2014-01-01

In the atavistic model of cancer progression, tumor cell dedifferentiation is interpreted as a reversion to phylogenetically earlier capabilities. The more recently evolved capabilities are compromised first during cancer progression. This suggests a therapeutic strategy for targeting cancer: design challenges to cancer that can only be met by the recently evolved capabilities no longer functional in cancer cells. We describe several examples of this target-the-weakness strategy. Our most detailed example involves the immune system. The absence of adaptive immunity in immunosuppressed tumor environments is an irreversible weakness of cancer that can be exploited by creating a challenge that only the presence of adaptive immunity can meet. This leaves tumor cells more vulnerable than healthy tissue to pathogenic attack. Such a target-the-weakness therapeutic strategy has broad applications, and contrasts with current therapies that target the main strength of cancer: cell proliferation. PMID:25043755

Quantum weak turbulence with applications to semiconductor lasers

NASA Astrophysics Data System (ADS)

Lvov, Y. V.; Binder, R.; Newell, A. C.

1998-10-01

Based on a model Hamiltonian appropriate for the description of fermionic systems such as semiconductor lasers, we describe a natural asymptotic closure of the BBGKY hierarchy in complete analogy with that derived for classical weak turbulence. The main features of the interaction Hamiltonian are the inclusion of full Fermi statistics containing Pauli blocking and a simple, phenomenological, uniformly weak two-particle interaction potential equivalent to the static screening approximation. We find a new class of solutions to the quantum kinetic equation which are analogous to the Kolmogorov spectra of hydrodynamics and classical weak turbulence. They involve finite fluxes of particles and energy in momentum space and are particularly relevant for describing the behavior of systems containing sources and sinks. We make a prima facie case that these finite flux solutions can be important in the context of semiconductor lasers and show how they might be used to enhance laser performance.

Weak Fault Feature Extraction of Rolling Bearings Based on an Improved Kurtogram.

PubMed

Chen, Xianglong; Feng, Fuzhou; Zhang, Bingzhi

2016-09-13

Kurtograms have been verified to be an efficient tool in bearing fault detection and diagnosis because of their superiority in extracting transient features. However, the short-time Fourier Transform is insufficient in time-frequency analysis and kurtosis is deficient in detecting cyclic transients. Those factors weaken the performance of the original kurtogram in extracting weak fault features. Correlated Kurtosis (CK) is then designed, as a more effective solution, in detecting cyclic transients. Redundant Second Generation Wavelet Packet Transform (RSGWPT) is deemed to be effective in capturing more detailed local time-frequency description of the signal, and restricting the frequency aliasing components of the analysis results. The authors in this manuscript, combining the CK with the RSGWPT, propose an improved kurtogram to extract weak fault features from bearing vibration signals. The analysis of simulation signals and real application cases demonstrate that the proposed method is relatively more accurate and effective in extracting weak fault features.

Learning and recognition of on-premise signs from weakly labeled street view images.

PubMed

Tsai, Tsung-Hung; Cheng, Wen-Huang; You, Chuang-Wen; Hu, Min-Chun; Tsui, Arvin Wen; Chi, Heng-Yu

2014-03-01

Camera-enabled mobile devices are commonly used as interaction platforms for linking the user's virtual and physical worlds in numerous research and commercial applications, such as serving an augmented reality interface for mobile information retrieval. The various application scenarios give rise to a key technique of daily life visual object recognition. On-premise signs (OPSs), a popular form of commercial advertising, are widely used in our living life. The OPSs often exhibit great visual diversity (e.g., appearing in arbitrary size), accompanied with complex environmental conditions (e.g., foreground and background clutter). Observing that such real-world characteristics are lacking in most of the existing image data sets, in this paper, we first proposed an OPS data set, namely OPS-62, in which totally 4649 OPS images of 62 different businesses are collected from Google's Street View. Further, for addressing the problem of real-world OPS learning and recognition, we developed a probabilistic framework based on the distributional clustering, in which we proposed to exploit the distributional information of each visual feature (the distribution of its associated OPS labels) as a reliable selection criterion for building discriminative OPS models. Experiments on the OPS-62 data set demonstrated the outperformance of our approach over the state-of-the-art probabilistic latent semantic analysis models for more accurate recognitions and less false alarms, with a significant 151.28% relative improvement in the average recognition rate. Meanwhile, our approach is simple, linear, and can be executed in a parallel fashion, making it practical and scalable for large-scale multimedia applications.

Microgravity Processing of Oxide Superconductors

NASA Technical Reports Server (NTRS)

Olive, James R.; Hofmeister, William H.; Bayuzick, Robert J.; Vlasse, Marcus

1999-01-01

Considerable effort has been concentrated on the synthesis and characterization of high T(sub c) oxide superconducting materials. The YBaCuO system has received the most intense study, as this material has shown promise for the application of both thin film and bulk materials. There are many problems with the application of bulk materials- weak links, poor connectivity, small coherence length, oxygen content and control, environmental reactivity, phase stability, incongruent melting behavior, grain boundary contamination, brittle mechanical behavior, and flux creep. The extent to which these problems are intrinsic or associated with processing is the subject of controversy. This study seeks to understand solidification processing of these materials, and to use this knowledge for alternative processing strategies, which, at the very least, will improve the understanding of bulk material properties and deficiencies. In general, the phase diagram studies of the YBaCuO system have concentrated on solid state reactions and on the Y2BaCuO(x) + liquid yields YBa2Cu3O(7-delta) peritectic reaction. Little information is available on the complete melting relations, undercooling, and solidification behavior of these materials. In addition, rare earth substitutions such as Nd and Gd affect the liquidus and phase relations. These materials have promising applications, but lack of information on the high temperature phase relations has hampered research. In general, the understanding of undercooling and solidification of high temperature oxide systems lags behind the science of these phenomena in metallic systems. Therefore, this research investigates the fundamental melting relations, undercooling, and solidification behavior of oxide superconductors with an emphasis on improving ground based synthesis of these materials.

Whole-body vibration to prevent intensive care unit-acquired weakness: safety, feasibility, and metabolic response.

PubMed

Wollersheim, Tobias; Haas, Kurt; Wolf, Stefan; Mai, Knut; Spies, Claudia; Steinhagen-Thiessen, Elisabeth; Wernecke, Klaus-D; Spranger, Joachim; Weber-Carstens, Steffen

2017-01-09

Intensive care unit (ICU)-acquired weakness in critically ill patients is a common and significant complication affecting the course of critical illness. Whole-body vibration is known to be effective muscle training and may be an option in diminishing weakness and muscle wasting. Especially, patients who are immobilized and not available for active physiotherapy may benefit. Until now whole-body vibration was not investigated in mechanically ventilated ICU patients. We investigated the safety, feasibility, and metabolic response of whole-body vibration in critically ill patients. We investigated 19 mechanically ventilated, immobilized ICU patients. Passive range of motion was performed prior to whole-body vibration therapy held in the supine position for 15 minutes. Continuous monitoring of vital signs, hemodynamics, and energy metabolism, as well as intermittent blood sampling, took place from the start of baseline measurements up to 1 hour post intervention. We performed comparative longitudinal analysis of the phases before, during, and after intervention. Vital signs and hemodynamic parameters remained stable with only minor changes resulting from the intervention. No application had to be interrupted. We did not observe any adverse event. Whole-body vibration did not significantly and/or clinically change vital signs and hemodynamics. A significant increase in energy expenditure during whole-body vibration could be observed. In our study the application of whole-body vibration was safe and feasible. The technique leads to increased energy expenditure. This may offer the chance to treat patients in the ICU with whole-body vibration. Further investigations should focus on the efficacy of whole-body vibration in the prevention of ICU-acquired weakness. Applicability and Safety of Vibration Therapy in Intensive Care Unit (ICU) Patients. ClinicalTrials.gov NCT01286610 . Registered 28 January 2011.

Semi-Supervised Clustering for High-Dimensional and Sparse Features

ERIC Educational Resources Information Center

Yan, Su

2010-01-01

Clustering is one of the most common data mining tasks, used frequently for data organization and analysis in various application domains. Traditional machine learning approaches to clustering are fully automated and unsupervised where class labels are unknown a priori. In real application domains, however, some "weak" form of side…

Generalized Parameter-Adjusted Stochastic Resonance of Duffing Oscillator and Its Application to Weak-Signal Detection

PubMed Central

Lai, Zhi-Hui; Leng, Yong-Gang

2015-01-01

A two-dimensional Duffing oscillator which can produce stochastic resonance (SR) is studied in this paper. We introduce its SR mechanism and present a generalized parameter-adjusted SR (GPASR) model of this oscillator for the necessity of parameter adjustments. The Kramers rate is chosen as the theoretical basis to establish a judgmental function for judging the occurrence of SR in this model; and to analyze and summarize the parameter-adjusted rules under unmatched signal amplitude, frequency, and/or noise-intensity. Furthermore, we propose the weak-signal detection approach based on this GPASR model. Finally, we employ two practical examples to demonstrate the feasibility of the proposed approach in practical engineering application. PMID:26343671

Wide dynamic range enrichment method of semiconducting single-walled carbon nanotubes with weak field centrifugation

NASA Astrophysics Data System (ADS)

Reis, Wieland G.; Tomović, Željko; Weitz, R. Thomas; Krupke, Ralph; Mikhael, Jules

2017-03-01

The potential of single-walled carbon nanotubes (SWCNTs) to outperform silicon in electronic application was finally enabled through selective separation of semiconducting nanotubes from the as-synthesized statistical mix with polymeric dispersants. Such separation methods provide typically high semiconducting purity samples with narrow diameter distribution, i.e. almost single chiralities. But for a wide range of applications high purity mixtures of small and large diameters are sufficient or even required. Here we proof that weak field centrifugation is a diameter independent method for enrichment of semiconducting nanotubes. We show that the non-selective and strong adsorption of polyarylether dispersants on nanostructured carbon surfaces enables simple separation of diverse raw materials with different SWCNT diameter. In addition and for the first time, we demonstrate that increased temperature enables higher purity separation. Furthermore we show that the mode of action behind this electronic enrichment is strongly connected to both colloidal stability and protonation. By giving simple access to electronically sorted SWCNTs of any diameter, the wide dynamic range of weak field centrifugation can provide economical relevance to SWCNTs.

Nonlocal interferometry with macroscopic coherent states and its application to quantum communications

NASA Astrophysics Data System (ADS)

Kirby, Brian

Macroscopic quantum effects are of fundamental interest because they help us to understand the quantum-classical boundary, and may also have important practical applications in long-range quantum communications. Specifically we analyze a macroscopic generalization of the Franson interferometer, where violations of Bell's inequality can be observed using phase entangled coherent states created using weak nonlinearities. Furthermore we want to understand how these states, and other macroscopic quantum states, can be applied to secure quantum communications. We find that Bell's inequality can be violated at ranges of roughly 400 km in optical fiber when various unambiguous state discrimination techniques are applied. In addition Monte Carlo simulations suggest that quantum communications schemes based on macroscopic quantum states and random unitary transformations can be potentially secure at long distances. Lastly, we calculate the feasibility of creating the weak nonlinearity needed for the experimental realization of these proposals using metastable xenon in a high finesse cavity. This research suggests that quantum states created using macroscopic coherent states and weak nonlinearities may be a realistic path towards the realization of secure long-range quantum communications.

Ensemble codes involving hippocampal neurons are at risk during delayed performance tests.

PubMed

Hampson, R E; Deadwyler, S A

1996-11-26

Multielectrode recording techniques were used to record ensemble activity from 10 to 16 simultaneously active CA1 and CA3 neurons in the rat hippocampus during performance of a spatial delayed-nonmatch-to-sample task. Extracted sources of variance were used to assess the nature of two different types of errors that accounted for 30% of total trials. The two types of errors included ensemble "miscodes" of sample phase information and errors associated with delay-dependent corruption or disappearance of sample information at the time of the nonmatch response. Statistical assessment of trial sequences and associated "strength" of hippocampal ensemble codes revealed that miscoded error trials always followed delay-dependent error trials in which encoding was "weak," indicating that the two types of errors were "linked." It was determined that the occurrence of weakly encoded, delay-dependent error trials initiated an ensemble encoding "strategy" that increased the chances of being correct on the next trial and avoided the occurrence of further delay-dependent errors. Unexpectedly, the strategy involved "strongly" encoding response position information from the prior (delay-dependent) error trial and carrying it forward to the sample phase of the next trial. This produced a miscode type error on trials in which the "carried over" information obliterated encoding of the sample phase response on the next trial. Application of this strategy, irrespective of outcome, was sufficient to reorient the animal to the proper between trial sequence of response contingencies (nonmatch-to-sample) and boost performance to 73% correct on subsequent trials. The capacity for ensemble analyses of strength of information encoding combined with statistical assessment of trial sequences therefore provided unique insight into the "dynamic" nature of the role hippocampus plays in delay type memory tasks.

Linking Tropical Forest Function to Hydraulic Traits in a Size-Structured and Trait-Based Model

NASA Astrophysics Data System (ADS)

Christoffersen, B. O.; Gloor, M.; Fauset, S.; Fyllas, N.; Galbraith, D.; Baker, T. R.; Rowland, L.; Fisher, R.; Binks, O.; Sevanto, S.; Xu, C.; Jansen, S.; Choat, B.; Mencuccini, M.; McDowell, N. G.; Meir, P.

2015-12-01

A major weakness of forest ecosystem models is their inability to capture the diversity of responses to changes in water availability, severely hampering efforts to predict the fate of tropical forests under climate change. Such models often prescribe moisture sensitivity using heuristic response functions that are uniform across all individuals and lack important knowledge about trade-offs in hydraulic traits. We address this weakness by implementing a process representation of plant hydraulics into an individual- and trait-based model (Trait Forest Simulator; TFS) intended for application at discrete sites where community-level distributions of stem and leaf trait spectra (wood density, leaf mass per area, leaf nitrogen and phosphorus content) are known. The model represents a trade-off in the safety and efficiency of water conduction in xylem tissue through hydraulic traits, while accounting for the counteracting effects of increasing hydraulic path length and xylem conduit taper on whole-plant hydraulic resistance with increasing tree size. Using existing trait databases and additional meta-analyses from the rich literature on tropical tree ecophysiology, we obtained all necessary hydraulic parameters associated with xylem conductivity, vulnerability curves, pressure-volume curves, and hydraulic architecture (e.g., leaf-to-sapwood area ratios) as a function of the aforementioned traits and tree size. Incorporating these relationships in the model greatly improved the diversity of tree response to seasonal changes in water availability as well as in response to drought, as determined by comparison with field observations and experiments. Importantly, this individual- and trait-based framework provides a testbed for identifying both critical processes and functional traits needed for inclusion in coarse-scale Dynamic Global Vegetation Models, which will lead to reduced uncertainty in the future state of tropical forests.

Spectral editing of weakly coupled spins using variable flip angles in PRESS constant echo time difference spectroscopy: Application to GABA

NASA Astrophysics Data System (ADS)

Snyder, Jeff; Hanstock, Chris C.; Wilman, Alan H.

2009-10-01

A general in vivo magnetic resonance spectroscopy editing technique is presented to detect weakly coupled spin systems through subtraction, while preserving singlets through addition, and is applied to the specific brain metabolite γ-aminobutyric acid (GABA) at 4.7 T. The new method uses double spin echo localization (PRESS) and is based on a constant echo time difference spectroscopy approach employing subtraction of two asymmetric echo timings, which is normally only applicable to strongly coupled spin systems. By utilizing flip angle reduction of one of the two refocusing pulses in the PRESS sequence, we demonstrate that this difference method may be extended to weakly coupled systems, thereby providing a very simple yet effective editing process. The difference method is first illustrated analytically using a simple two spin weakly coupled spin system. The technique was then demonstrated for the 3.01 ppm resonance of GABA, which is obscured by the strong singlet peak of creatine in vivo. Full numerical simulations, as well as phantom and in vivo experiments were performed. The difference method used two asymmetric PRESS timings with a constant total echo time of 131 ms and a reduced 120° final pulse, providing 25% GABA yield upon subtraction compared to two short echo standard PRESS experiments. Phantom and in vivo results from human brain demonstrate efficacy of this method in agreement with numerical simulations.

A study of 60 GHz intersatellite link applications

NASA Technical Reports Server (NTRS)

Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

1983-01-01

Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

A study of 60 Gigahertz intersatellite link applications

NASA Astrophysics Data System (ADS)

Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

A study of 60 Gigahertz intersatellite link applications

NASA Technical Reports Server (NTRS)

Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

1983-01-01

Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

A study of 60 GHz intersatellite link applications

NASA Astrophysics Data System (ADS)

Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

Betweenness centrality in a weighted network

NASA Astrophysics Data System (ADS)

Wang, Huijuan; Hernandez, Javier Martin; van Mieghem, Piet

2008-04-01

When transport in networks follows the shortest paths, the union of all shortest path trees G∪SPT can be regarded as the “transport overlay network.” Overlay networks such as peer-to-peer networks or virtual private networks can be considered as a subgraph of G∪SPT . The traffic through the network is examined by the betweenness Bl of links in the overlay G∪SPT . The strength of disorder can be controlled by, e.g., tuning the extreme value index α of the independent and identically distributed polynomial link weights. In the strong disorder limit (α→0) , all transport flows over a critical backbone, the minimum spanning tree (MST). We investigate the betweenness distributions of wide classes of trees, such as the MST of those well-known network models and of various real-world complex networks. All these trees with different degree distributions (e.g., uniform, exponential, or power law) are found to possess a power law betweenness distribution Pr[Bl=j]˜j-c . The exponent c seems to be positively correlated with the degree variance of the tree and to be insensitive of the size N of a network. In the weak disorder regime, transport in the network traverses many links. We show that a link with smaller link weight tends to carry more traffic. This negative correlation between link weight and betweenness depends on α and the structure of the underlying topology.

Analysis of trace inorganic anions in weak acid salts by single pump cycling-column-switching ion chromatography.

PubMed

Huang, Zhongping; Ni, Chengzhu; Zhu, Zhuyi; Pan, Zaifa; Wang, Lili; Zhu, Yan

2015-05-01

The application of ion chromatography with the single pump cycling-column-switching technique was described for the analysis of trace inorganic anions in weak acid salts within a single run. Due to the hydrogen ions provided by an anion suppressor electrolyzing water, weak acid anions could be transformed into weak acids, existing as molecules, after passing through the suppressor. Therefore, an anion suppressor and ion-exclusion column were adopted to achieve on-line matrix elimination of weak acid anions with high concentration for the analysis of trace inorganic anions in weak acid salts. A series of standard solutions consisting of target anions of various concentrations from 0.005 to 10 mg/L were analyzed, with correlation coefficients r ≥ 0.9990. The limits of detection were in the range of 0.67 to 1.51 μg/L, based on the signal-to-noise ratio of 3 and a 25 μL injection volume. Relative standard deviations for retention time, peak area, and peak height were all less than 2.01%. A spiking study was performed with satisfactory recoveries between 90.3 and 104.4% for all anions. The chromatographic system was successfully applied to the analysis of trace inorganic anions in five weak acid salts. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Entanglement and Weak Values: A Quantum Miracle Cookbook

NASA Astrophysics Data System (ADS)

Botero, Alonso

The concept of the weak value has proved to be a powerful and operationally grounded framework for the assignment of physical properties to a quantum system at any given time. More importantly, this framework has allowed us to identify a whole range of surprising quantum effects, or "miracles", which are readily testable but which lie buried "under the noise" when the results of measurements are not post-selected. In all cases, these miracles have to do with the fact that weak values can take values lying outside the conventional ranges of quantum expectation values. We explore the extent to which such miracles are possible within the weak value framework. As we show, given appropriate initial and final states, it is generally possible to produce any set of weak values that is consistent with the linearity of weak values, provided that the states are entangled states of the system with some external ancillary system. Through a simple constructive proof, we obtain a recipe for arbitrary quantum miracles, and give examples of some interesting applications. In particular, we show how the classical description of an infinitely-localized point in phase-space is contained in the weak-value framework augmented by quantum entanglement. [Editor's note: for a video of the talk given by Prof. Botero at the Aharonov-80 conference in 2012 at Chapman University, see http://quantum.chapman.edu/talk-27.

International health policy and stagnating maternal mortality: is there a causal link?

PubMed

Unger, Jean-Pierre; Van Dessel, Patrick; Sen, Kasturi; De Paepe, Pierre

2009-05-01

This paper examines why progress towards Millennium Development Goal 5 on maternal health appears to have stagnated in much of the global south. We contend that besides the widely recognised existence of weak health systems, including weak services, low staffing levels, managerial weaknesses, and lack of infrastructure and information, this stagnation relates to the inability of most countries to meet two essential conditions: to develop access to publicly funded, comprehensive health care, and to provide the not-for-profit sector with needed political, technical and financial support. This paper offers a critical perspective on the past 15 years of international health policies as a possible cofactor of high maternal mortality, because of their emphasis on disease control in public health services at the expense of access to comprehensive health care, and failures of contracting out and public-private partnerships in health care. Health care delivery cannot be an issue both of trade and of right. Without policies to make health systems in the global south more publicly-oriented and accountable, the current standards of maternal and child health care are likely to remain poor, and maternal deaths will continue to affect women and their families at an intolerably high level.

More Frequent Weak Stratospheric Polar Vortex States Linked to Cold Extremes

NASA Astrophysics Data System (ADS)

Kretschmer, M.; Coumou, D.; Agel, L. A.; Barlow, M. A.; Tziperman, E.; Cohen, J. L.

2016-12-01

The extra-tropical stratosphere in boreal winter is characterized by a strong circumpolar westerly jet, referred to as the stratospheric polar vortex (SPV) which confines cold temperatures at high latitudes. Previous studies showed that a weak SPV can lead to cold-air outbreaks in the mid-latitudes but the exact relationships and mechanisms are still unclear. Particularly, it is unclear whether stratospheric variability has contributed to the observed anomalous cooling trends in Central and eastern Asia. Using hierarchical clustering, we show that over the last 37 years, the frequency of weak vortex states in mid to late winter (January and February) has increased significantly accompanied by subsequent cold surface temperatures in the mid-latitudes. Furthermore, we show that stratospheric and El Niño/Southern Oscillation (ENSO) variability can explain most of the observed spatially heterogenic winter temperature trends in the era of Arctic amplification but the contribution of ENSO is less important. We show that the weakening of the SPV was related to a strengthening Siberian high and poleward heat flux. These findings support the hypothesis that a warming Arctic has weakened the SPV and thereby increased the frequency of cold-air outbreaks.

Electric organ discharge diversification in mormyrid weakly electric fish is associated with differential expression of voltage-gated ion channel genes.

PubMed

Nagel, Rebecca; Kirschbaum, Frank; Tiedemann, Ralph

2017-03-01

In mormyrid weakly electric fish, the electric organ discharge (EOD) is used for species recognition, orientation and prey localization. Produced in the muscle-derived adult electric organ, the EOD exhibits a wide diversity across species in both waveform and duration. While certain defining EOD characteristics can be linked to anatomical features of the electric organ, many factors underlying EOD differentiation are yet unknown. Here, we report the differential expression of 13 Kv1 voltage-gated potassium channel genes, two inwardly rectifying potassium channel genes, two previously studied sodium channel genes and an ATPase pump in two sympatric species of the genus Campylomormyrus in both the adult electric organ and skeletal muscle. Campylomormyrus compressirostris displays a basal EOD, largely unchanged during development, while C. tshokwe has an elongated, putatively derived discharge. We report an upregulation in all Kv1 genes in the electric organ of Campylomormyrus tshokwe when compared to both skeletal muscle and C. compressirostris electric organ. This pattern of upregulation in a species with a derived EOD form suggests that voltage-gated potassium channels are potentially involved in the diversification of the EOD signal among mormyrid weakly electric fish.

Efficient Wide Baseline Structure from Motion

NASA Astrophysics Data System (ADS)

Michelini, Mario; Mayer, Helmut

2016-06-01

This paper presents a Structure from Motion approach for complex unorganized image sets. To achieve high accuracy and robustness, image triplets are employed and (an approximate) camera calibration is assumed to be known. The focus lies on a complete linking of images even in case of large image distortions, e.g., caused by wide baselines, as well as weak baselines. A method for embedding image descriptors into Hamming space is proposed for fast image similarity ranking. The later is employed to limit the number of pairs to be matched by a wide baseline method. An iterative graph-based approach is proposed formulating image linking as the search for a terminal Steiner minimum tree in a line graph. Finally, additional links are determined and employed to improve the accuracy of the pose estimation. By this means, loops in long image sequences are implicitly closed. The potential of the proposed approach is demonstrated by results for several complex image sets also in comparison with VisualSFM.

Community resilience and health: the role of bonding, bridging, and linking aspects of social capital.

PubMed

Poortinga, Wouter

2012-03-01

The current study draws on data from the 2007 and 2009 Citizenship Survey collected in England (n=17,572) to explore the role of social capital in building community resilience and health, using the bonding, bridging, and linking social capital framework of Szreter and Woolcock (2004). The results show that the indicators of the different types of social capital are only weakly interrelated, suggesting that they capture different aspects of the social environment. In line with the expectations, most indicators of bonding, bridging, and linking social capital were significantly associated with neighbourhood deprivation and self-reported health. In particular bonding and bridging social cohesion, civic participation, heterogeneous socio-economic relationships, and political efficacy and trust appeared important for community health after controlling for neighbourhood deprivation. However, no support was found for the hypothesis that the different aspects help buffer against the detrimental influences of neighbourhood deprivation. Copyright © 2011 Elsevier Ltd. All rights reserved.

The costs of racism for marriage: how racial discrimination hurts, and ethnic identity protects, newlywed marriages among Latinos.

PubMed

Trail, Thomas E; Goff, Phillip Atiba; Bradbury, Thomas N; Karney, Benjamin R

2012-04-01

The experience of racial or ethnic discrimination is a salient and severe stressor that has been linked to numerous disparities in important outcomes. Yet, the link between perceived discrimination and marital outcomes has been overlooked by research on relationship stressors. The current study examined this link and tested whether ethnic identity buffered the relation between discrimination and ratings of marital quality and verbal aggression. A sample of 330 Latino newlyweds completed measures of perceived discrimination, ethnic identity, spouse's verbal aggression, and marital quality. Each spouse's interviewer also independently rated marital quality. Dyadic analyses revealed that husbands' experience of discrimination negatively predicted wives' marital quality, but only for husbands with weak ethnic identity. Wives whose husbands had strong ethnic identity were buffered from this effect. Identity also buffered the relation between husbands' discrimination and verbal aggression toward their wives, and this effect mediated the association between discrimination, identity, and marital quality.

Development Issues on Linked Data Weblog Enrichment

NASA Astrophysics Data System (ADS)

Ruiz-Rube, Iván; Cornejo, Carlos M.; Dodero, Juan Manuel; García, Vicente M.

In this paper, we describe the issues found during the development of LinkedBlog, a Linked Data extension for WordPress blogs. This extension enables to enrich text-based and video information contained in blog entries with RDF triples that are suitable to be stored, managed and exploited by other web-based applications. The issues have to do with the generality, usability, tracking, depth, security, trustiness and performance of the linked data enrichment process. The presented annotation approach aims at maintaining web-based contents independent from the underlying ontological model, by providing a loosely coupled RDFa-based approach in the linked data application. Finally, we detail how the performance of annotations can be improved through a semantic reasoner.

5-Benzoyl-13-bromo-4-hy­droxy[2.2]paracyclo­phane

PubMed Central

Ma, Kelin; Duan, Wenzeng; He, Fuyan; Ma, Yudao

2012-01-01

The title compound, C23H19BrO2, was synthesized from 13-bromo-4-hy­droxy[2.2]paracyclo­phane and benzoyl chloride. The hy­droxy and carbonyl groups are involved in intra­molecular O—H⋯O hydrogen bonding. The crystal packing exhibits weak C—H⋯O inter­actions, which link the mol­ecules into sheets parallel to the bc plane. PMID:22590271

Predicting the recruitment of established regeneration into the sapling size class following partial cutting in the Acadian Forest Region: Using long-term observations to assess the performance of FVS-NE

Treesearch

David Ray; Chad Keyser; Robert Seymour; John Brissette

2008-01-01

Forest managers are increasingly called upon to provide long-term predictions of forest development. The dynamics of regeneration establishment, survival and subsequent recruitment of established seedlings to larger size classes is a critical component of these forecasts, yet remains a weak link in available models. To test the reliability of FVS-NE for simulating...

catena-Poly[[[4,6-bis-(2-pyrid-yl)-1,3,5-triazin-2-olato]copper(II)]-μ-chlorido].

PubMed

Cao, Man-Li

2011-06-01

The title compound, [Cu(C(13)H(8)N(5)O)Cl](n), has a chain structure parallel to [100] with Cu(2+) cations in a trigonal-bipyramidal coordination environment. The ligand adopts a tridentate tripyridyl coordination mode and a chloride ion acts as a bridge. The chains are linked via weak C-H⋯O and C-H⋯Cl hydrogen bonds into a three-dimensional supra-molecular network.

1,5-Bis[(E)-cyclo-pentyl-idene]thio-carbono-hydrazide.

PubMed

Guo, Qingliang; Sun, Junshan; Li, Jikun; Wu, Rentao; Duan, Wenzeng

2009-03-25

In the title mol-ecule, C(11)H(18)N(4)S, an intra-molecular N-H⋯N hydrogen bond [N⋯N = 2.558 (3)Å] is observed. The two cyclo-pentyl rings are disordered between two conformations in 1:1 and 2:1 ratios. In the crystal structure, weak inter-molecular N-H⋯S hydrogen bonds [N⋯S = 3.547 (3) Å] link pairs of mol-ecules into centrosymmetric dimers.

Calculations of predissociative lifetimes of RG...Hal2 Van der Waals complexes

NASA Astrophysics Data System (ADS)

Buchachenko, Alexei A.; Stepanov, N. F.

1992-07-01

Good examples of combined energy- and time-resolved techniques linked by the theoretical solution of a nuclear problem may be found in investigations of the dynamics of weakly bound Van der Waals (VdW) complexes, such as Ar-OH and He-stilbene. Our report concerns only the theoretical aspect of this complex approach. However, we shall stress the importance of energy-resolved spectroscopy for the dynamics and try to illustrate this with some numerical results.

Mine safety assessment using gray relational analysis and bow tie model

PubMed Central

2018-01-01

Mine safety assessment is a precondition for ensuring orderly and safety in production. The main purpose of this study was to prevent mine accidents more effectively by proposing a composite risk analysis model. First, the weights of the assessment indicators were determined by the revised integrated weight method, in which the objective weights were determined by a variation coefficient method and the subjective weights determined by the Delphi method. A new formula was then adopted to calculate the integrated weights based on the subjective and objective weights. Second, after the assessment indicator weights were determined, gray relational analysis was used to evaluate the safety of mine enterprises. Mine enterprise safety was ranked according to the gray relational degree, and weak links of mine safety practices identified based on gray relational analysis. Third, to validate the revised integrated weight method adopted in the process of gray relational analysis, the fuzzy evaluation method was used to the safety assessment of mine enterprises. Fourth, for first time, bow tie model was adopted to identify the causes and consequences of weak links and allow corresponding safety measures to be taken to guarantee the mine’s safe production. A case study of mine safety assessment was presented to demonstrate the effectiveness and rationality of the proposed composite risk analysis model, which can be applied to other related industries for safety evaluation. PMID:29561875

Contribution of oxidative stress to pathology in diaphragm and limb muscles with Duchenne muscular dystrophy.

PubMed

Kim, Jong-Hee; Kwak, Hyo-Bum; Thompson, LaDora V; Lawler, John M

2013-02-01

Duchenne muscular dystrophy (DMD) is a degenerative skeletal muscle disease that makes walking and breathing difficult. DMD is caused by an X-linked (Xp21) mutation in the dystrophin gene. Dystrophin is a scaffolding protein located in the sarcolemmal cytoskeleton, important in maintaining structural integrity and regulating muscle cell (muscle fiber) growth and repair. Dystrophin deficiency in mouse models (e.g., mdx mouse) destabilizes the interface between muscle fibers and the extracellular matrix, resulting in profound damage, inflammation, and weakness in diaphragm and limb muscles. While the link between dystrophin deficiency with inflammation and pathology is multi-factorial, elevated oxidative stress has been proposed as a central mediator. Unfortunately, the use of non-specific antioxidant scavengers in mouse and human studies has led to inconsistent results, obscuring our understanding of the importance of redox signaling in pathology of muscular dystrophy. However, recent studies with more mechanistic approaches in mdx mice suggest that NAD(P)H oxidase and nuclear factor-kappaB are important in amplifying dystrophin-deficient muscle pathology. Therefore, more targeted antioxidant therapeutics may ameliorate damage and weakness in human population, thus promoting better muscle function and quality of life. This review will focus upon the pathobiology of dystrophin deficiency in diaphragm and limb muscle primarily in mouse models, with a rationale for development of targeted therapeutic antioxidants in DMD patients.

Study of strong turbulence effects for optical wireless links

NASA Astrophysics Data System (ADS)

Yuksel, Heba; Meric, Hasim; Kunter, Fulya

2012-10-01

Strong turbulence measurements that are taken using real time optical wireless experimental setups are valuable when studying the effects of turbulence regimes on a propagating optical beam. In any kind of FSO system, for us to know the strength of the turbulence thus the refractive index structure constant, is beneficial for having an optimum bandwidth of communication. Even if the FSO Link is placed very well-high-above the ground just to have weak enough turbulence effects, there can be severe atmospheric conditions that can change the turbulence regime. Having a successful theory that will cover all regimes will give us the chance of directly processing the image in existing or using an additional hardware thus deciding on the optimum bandwidth of the communication line at firsthand. For this purpose, Strong Turbulence data has been collected using an outdoor optical wireless setup placed about 85 centimeters above the ground with an acceptable declination and a path length of about 250 meters inducing strong turbulence to the propagating beam. Variations of turbulence strength estimation methods as well as frame image analysis techniques are then been applied to the experimental data in order to study the effects of different parameters on the result. Such strong turbulence data is compared with existing weak and intermediate turbulence data. Aperture Averaging Factor for different turbulence regimes is also investigated.

Crystallographic orientation mapping with an electron backscattered diffraction technique in (Bi, Pb)2Sr2Ca2Cu3O10 superconductor tapes

NASA Astrophysics Data System (ADS)

Tan, T. T.; Li, S.; Oh, J. T.; Gao, W.; Liu, H. K.; Dou, S. X.

2001-02-01

It is believed that grain boundaries act as weak links in limiting the critical current density (Jc) of bulk high-Tc superconductors. The weak-link problem can be greatly reduced by elimination or minimization of large-angle grain boundaries. It has been reported that the distribution of the Jc in (Bi, Pb)2Sr2Ca2Cu3O10+x (Bi2223) superconductor tapes presents a parabolic relationship in the transverse cross section of the tapes, with the lowest currents occurring at the centre of the tapes. It was proposed that the Jc distribution is strongly dependent on the local crystallographic orientation distribution of the Bi2223 oxides. However, the local three-dimensional crystallographic orientation distribution of Bi2223 crystals in (Bi, Pb)2Sr2Ca2Cu3O10+x superconductor tapes has not yet been experimentally determined. In this work, the electron backscattered diffraction technique was employed to map the crystallographic orientation distribution, determine the misorientation of grain boundaries and also map the misorientation distribution in Bi2223 superconductor tapes. Through crystallographic orientation mapping, the relationship between the crystallographic orientation distribution, the boundary misorientation distribution and the fabrication parameters may be understood. This can be used to optimize the fabrication processes thus increasing the critical current density in Bi2223 superconductor tapes.

Spontaneous ultra-weak photon emission in correlation to inflammatory metabolism and oxidative stress in a mouse model of collagen-induced arthritis.

PubMed

He, Min; van Wijk, Eduard; van Wietmarschen, Herman; Wang, Mei; Sun, Mengmeng; Koval, Slavik; van Wijk, Roeland; Hankemeier, Thomas; van der Greef, Jan

2017-03-01

The increasing prevalence of rheumatoid arthritis has driven the development of new approaches and technologies for investigating the pathophysiology of this devastating, chronic disease. From the perspective of systems biology, combining comprehensive personal data such as metabolomics profiling with ultra-weak photon emission (UPE) data may provide key information regarding the complex pathophysiology underlying rheumatoid arthritis. In this article, we integrated UPE with metabolomics-based technologies in order to investigate collagen-induced arthritis, a mouse model of rheumatoid arthritis, at the systems level, and we investigated the biological underpinnings of the complex dataset. Using correlation networks, we found that elevated inflammatory and ROS-mediated plasma metabolites are strongly correlated with a systematic reduction in amine metabolites, which is linked to muscle wasting in rheumatoid arthritis. We also found that increased UPE intensity is strongly linked to metabolic processes (with correlation co-efficiency |r| value >0.7), which may be associated with lipid oxidation that related to inflammatory and/or ROS-mediated processes. Together, these results indicate that UPE is correlated with metabolomics and may serve as a valuable tool for diagnosing chronic disease by integrating inflammatory signals at the systems level. Our correlation network analysis provides important and valuable information regarding the disease process from a system-wide perspective. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular motors interacting with their own tracks

NASA Astrophysics Data System (ADS)

Artyomov, Max N.; Morozov, Alexander Yu.; Kolomeisky, Anatoly B.

2008-04-01

Dynamics of molecular motors that move along linear lattices and interact with them via reversible destruction of specific lattice bonds is investigated theoretically by analyzing exactly solvable discrete-state “burnt-bridge” models. Molecular motors are viewed as diffusing particles that can asymmetrically break or rebuild periodically distributed weak links when passing over them. Our explicit calculations of dynamic properties show that coupling the transport of the unbiased molecular motor with the bridge-burning mechanism leads to a directed motion that lowers fluctuations and produces a dynamic transition in the limit of low concentration of weak links. Interaction between the backward biased molecular motor and the bridge-burning mechanism yields a complex dynamic behavior. For the reversible dissociation the backward motion of the molecular motor is slowed down. There is a change in the direction of the molecular motor’s motion for some range of parameters. The molecular motor also experiences nonmonotonic fluctuations due to the action of two opposing mechanisms: the reduced activity after the burned sites and locking of large fluctuations. Large spatial fluctuations are observed when two mechanisms are comparable. The properties of the molecular motor are different for the irreversible burning of bridges where the velocity and fluctuations are suppressed for some concentration range, and the dynamic transition is also observed. Dynamics of the system is discussed in terms of the effective driving forces and transitions between different diffusional regimes.

Superconductivity in highly disordered NbN nanowires.

PubMed

Arutyunov, K Yu; Ramos-Álvarez, A; Semenov, A V; Korneeva, Yu P; An, P P; Korneev, A A; Murphy, A; Bezryadin, A; Gol'tsman, G N

2016-11-25

The topic of superconductivity in strongly disordered materials has attracted significant attention. These materials appear to be rather promising for fabrication of various nanoscale devices such as bolometers and transition edge sensors of electromagnetic radiation. The vividly debated subject of intrinsic spatial inhomogeneity responsible for the non-Bardeen-Cooper-Schrieffer relation between the superconducting gap and the pairing potential is crucial both for understanding the fundamental issues of superconductivity in highly disordered superconductors, and for the operation of corresponding nanoelectronic devices. Here we report an experimental study of the electron transport properties of narrow NbN nanowires with effective cross sections of the order of the debated inhomogeneity scales. The temperature dependence of the critical current follows the textbook Ginzburg-Landau prediction for the quasi-one-dimensional superconducting channel I c  ∼ (1-T/T c ) 3/2 . We find that conventional models based on the the phase slip mechanism provide reasonable fits for the shape of R(T) transitions. Better agreement with R(T) data can be achieved assuming the existence of short 'weak links' with slightly reduced local critical temperature T c . Hence, one may conclude that an 'exotic' intrinsic electronic inhomogeneity either does not exist in our structures, or, if it does exist, it does not affect their resistive state properties, or does not provide any specific impact distinguishable from conventional weak links.

(Carbonyl-1κC)bis-[2,3(η)-cyclo-penta-dien-yl][μ(3)-(S-methyl trithio-carbonato)methylidyne-1:2:3κC,S'':C:C](triphenyl-phosphine-1κP)(μ(3)-sulfido-1:2:3κS)dicobalt(II)iron(II) trifluoro-methane-sulfonate.

PubMed

Manning, Anthony R; McAdam, C John; Palmer, Anthony J; Simpson, Jim

2008-04-10

The asymmetric unit of the title compound, [FeCo(2)(C(5)H(5))(2)(C(3)H(3)S(3))S(C(18)H(15)P)(CO)]CF(3)SO(3), consists of a triangular irondicobalt cluster cation and a trifluoro-methane-sulfonate anion. In the cation, the FeCo(2) triangle is symmetrically capped on one face by an S atom and on the other by a C atom linked to a methyl trithio-carbonate residue that bridges the Fe-C bond. Each Co atom carries a cyclo-penta-dienyl ligand while the Fe atom coordinates to one carbonyl and one triphenyl-phosphine ligand. In the crystal structure, the cation is linked to the anion by a number of weak non-classical C-H⋯O and C-H⋯F hydrogen bonds and weak S⋯O (3.317 Å) and S⋯F (3.198 Å) inter-actions. The structure is further stabilized by additional inter-molecular C-H⋯O, C-H⋯F and O⋯O (2.942 Å) contacts, together with an unusual S⋯π(Cp) inter-action (S⋯centroid distance = 3.385 Å), generating an extended network.

Vitamin D deficiency, oxidative stress and antioxidant status: only weak association seen in the absence of advanced age, obesity or pre-existing disease.

PubMed

Wang, Erica W; Siu, Parco M; Pang, Marco Y; Woo, Jean; Collins, Andrew R; Benzie, Iris F F

2017-07-01

Vitamin D deficiency (plasma 25-hydroxycholecalciferol (25(OH)D)70 % of participants were vitamin D deficient. No significant correlations and no biomarker differences across 25(OH)D quartiles or groups were seen except for total antioxidant status. A weak direct association (r 0·252, P<0·05) was observed between 25(OH)D and FRAP, and those in the lowest 25(OH)D quartile and group had significantly lower FRAP values. Results did not reveal a clear link between vitamin D status and oxidative stress biomarkers in the absence of advanced age, obesity and disease, though some evidence of depleted antioxidant status in those with vitamin D deficiency was seen. Poor antioxidant status may pre-date increased oxidative stress. Study of effects of correction of deficiency on antioxidant status and oxidative stress in vitamin D-deficient but otherwise healthy subjects is needed.

[Motor neglect of thalamic origin: report on two cases (author's transl)].

PubMed

Laplane, D; Escourolle, R; Degos, J D; Sauron, B; Massiou, H

1982-01-01

Two cases of thalamic lesions with motor neglect are presented. The syndrome of motor neglect was complete in those cases with a) underutilization of left limbs, but good utilization upon verbal orders, b) loss of placement reaction, c) weakness of movement when hand was approaching the target, d) weakness of motor reaction to nociceptive stimuli. Those cases confirm that motor neglect exists after thalamic lesions and bring pathologic clues for topographic discussion. Motor neglect seems to be a particular case of partial unilateral neglect throwing some doubt on the hypothesis of a global trouble of hemispheric activation. Prevalence of left motor neglects suggests some linkage between propositional motility and language. One may suppose that in the right hemisphere language is able to have a vicarious action when spontaneous activation is lost; at the opposite, in the left hemisphere language and motility would be too linked to let this dissociation be generally possible.

Durbolota (weakness), chinta rog (worry illness), and poverty: explanations of white discharge among married adolescent women in an urban slum in Dhaka, Bangladesh.

PubMed

Rashid, Sabina Faiz

2007-03-01

I carried out ethnographic fieldwork among 153 married adolescent girls, aged 15-19, in a Dhaka slum from December 2001 to January 2003, including 50 in-depth interviews and eight case studies. I also held discussions with family and community members. In this article, I focus on popular understandings of vaginal discharge being caused by durbolota (weakness) and chinta rog (worry illness), as mentioned by young women. Eighty-eight young women reported that they had experienced white discharge, blaming it on a number of factors such as stress and financial hardships, tensions in the household, marital instability, hunger anxiety, and reproductive burdens. For married adolescent women in the urban slum, white discharge has many levels of meaning linked to the broader social, political, and material inequalities in their everyday lives.

Long-distance thermal temporal ghost imaging over optical fibers

NASA Astrophysics Data System (ADS)

Yao, Xin; Zhang, Wei; Li, Hao; You, Lixing; Wang, Zhen; Huang, Yidong

2018-02-01

A thermal ghost imaging scheme between two distant parties is proposed and experimentally demonstrated over long-distance optical fibers. In the scheme, the weak thermal light is split into two paths. Photons in one path are spatially diffused according to their frequencies by a spatial dispersion component, then illuminate the object and record its spatial transmission information. Photons in the other path are temporally diffused by a temporal dispersion component. By the coincidence measurement between photons of two paths, the object can be imaged in a way of ghost imaging, based on the frequency correlation between photons in the two paths. In the experiment, the weak thermal light source is prepared by the spontaneous four-wave mixing in a silicon waveguide. The temporal dispersion is introduced by single mode fibers of 50 km, which also could be looked as a fiber link. Experimental results show that this scheme can be realized over long-distance optical fibers.

Polychromatic spectral pattern analysis of ultra-weak photon emissions from a human body.

PubMed

Kobayashi, Masaki; Iwasa, Torai; Tada, Mika

2016-06-01

Ultra-weak photon emission (UPE), often designated as biophoton emission, is generally observed in a wide range of living organisms, including human beings. This phenomenon is closely associated with reactive oxygen species (ROS) generated during normal metabolic processes and pathological states induced by oxidative stress. Application of UPE extracting the pathophysiological information has long been anticipated because of its potential non-invasiveness, facilitating its diagnostic use. Nevertheless, its weak intensity and UPE mechanism complexity hinder its use for practical applications. Spectroscopy is crucially important for UPE analysis. However, filter-type spectroscopy technique, used as a conventional method for UPE analysis, intrinsically limits its performance because of its monochromatic scheme. To overcome the shortcomings of conventional methods, the authors developed a polychromatic spectroscopy system for UPE spectral pattern analysis. It is based on a highly efficient lens systems and a transmission-type diffraction grating with a highly sensitive, cooled, charge-coupled-device (CCD) camera. Spectral pattern analysis of the human body was done for a fingertip using the developed system. The UPE spectrum covers the spectral range of 450-750nm, with a dominant emission region of 570-670nm. The primary peak is located in the 600-650nm region. Furthermore, application of UPE source exploration was demonstrated with the chemiluminescence spectrum of melanin and coexistence with oxidized linoleic acid. Copyright © 2016 Elsevier B.V. All rights reserved.

Correlation of the Rock Mass Rating (RMR) System with the Unified Soil Classification System (USCS): Introduction of the Weak Rock Mass Rating System (W-RMR)

NASA Astrophysics Data System (ADS)

Warren, Sean N.; Kallu, Raj R.; Barnard, Chase K.

2016-11-01

Underground gold mines in Nevada are exploiting increasingly deeper ore bodies comprised of weak to very weak rock masses. The Rock Mass Rating (RMR) classification system is widely used at underground gold mines in Nevada and is applicable in fair to good-quality rock masses, but is difficult to apply and loses reliability in very weak rock mass to soil-like material. Because very weak rock masses are transition materials that border engineering rock mass and soil classification systems, soil classification may sometimes be easier and more appropriate to provide insight into material behavior and properties. The Unified Soil Classification System (USCS) is the most likely choice for the classification of very weak rock mass to soil-like material because of its accepted use in tunnel engineering projects and its ability to predict soil-like material behavior underground. A correlation between the RMR and USCS systems was developed by comparing underground geotechnical RMR mapping to laboratory testing of bulk samples from the same locations, thereby assigning a numeric RMR value to the USCS classification that can be used in spreadsheet calculations and geostatistical analyses. The geotechnical classification system presented in this paper including a USCS-RMR correlation, RMR rating equations, and the Geo-Pick Strike Index is collectively introduced as the Weak Rock Mass Rating System (W-RMR). It is the authors' hope that this system will aid in the classification of weak rock masses and more usable design tools based on the RMR system. More broadly, the RMR-USCS correlation and the W-RMR system help define the transition between engineering soil and rock mass classification systems and may provide insight for geotechnical design in very weak rock masses.

Quantitative detection of the respective concentrations of chiral compounds with weak measurements

NASA Astrophysics Data System (ADS)

Xie, Linguo; Qiu, Xiaodong; Luo, Lan; Liu, Xiong; Li, Zhaoxue; Zhang, Zhiyou; Du, Jinglei; Wang, Deqiang

2017-11-01

In this letter, we determine the respective concentrations of glucose and fructose in the mixed chiral solution by simultaneously measuring the optical rotation angle (ORA) and the refractive index change (RIC) with weak measurements. The photonic spin Hall effect (PSHE) serves as a probe in our scheme. The measurement of ORA is based on the high sensitivity of the amplification factor to the polarization state in weak measurements. The measurement of RIC is based on the rapid variation of spin splitting of the PSHE. The measurement precision of the respective concentrations can be achieved to be 0.02 mg/ml. This method can detect traces of enantiomeric impurities and has a potential application in chiral sensing.

Alternative method of quantum state tomography toward a typical target via a weak-value measurement

NASA Astrophysics Data System (ADS)

Chen, Xi; Dai, Hong-Yi; Yang, Le; Zhang, Ming

2018-03-01

There is usually a limitation of weak interaction on the application of weak-value measurement. This limitation dominates the performance of the quantum state tomography toward a typical target in the finite and high-dimensional complex-valued superposition of its basis states, especially when the compressive sensing technique is also employed. Here we propose an alternative method of quantum state tomography, presented as a general model, toward such typical target via weak-value measurement to overcome such limitation. In this model the pointer for the weak-value measurement is a qubit, and the target-pointer coupling interaction is no longer needed within the weak interaction limitation, meanwhile this interaction under the compressive sensing can be described with the Taylor series of the unitary evolution operator. The postselection state at the target is the equal superposition of all basis states, and the pointer readouts are gathered under multiple Pauli operator measurements. The reconstructed quantum state is generated from an optimization algorithm of total variation augmented Lagrangian alternating direction algorithm. Furthermore, we demonstrate an example of this general model for the quantum state tomography toward the planar laser-energy distribution and discuss the relations among some parameters at both our general model and the original first-order approximate model for this tomography.

SUPG Finite Element Simulations of Compressible Flows for Aerothermodynamic Applications

NASA Technical Reports Server (NTRS)

Kirk, Benjamin S.

2007-01-01

This viewgraph presentation reviews the Streamline-Upwind Petrov-Galerkin (SUPG) Finite Element Simulation. It covers the background, governing equations, weak formulation, shock capturing, inviscid flux discretization, time discretization, linearization, and implicit solution strategies. It also reviews some applications such as Type IV Shock Interaction, Forward-Facing Cavity and AEDC Sharp Double Cone.

[Family characteristics and the labor market in developed countries: a clear distinction between north and south].

PubMed

Barrere-maurisson, M; Marchand, O

1990-09-01

The relationship between family characteristics and the labor market is explored using data concerning 15 OECD countries. Several distinct geographical groupings are identified, including the Mediterranean countries, Scandinavia, North America, and Japan and West Germany. Belgium, France, the Netherlands, and the United Kingdom occupy a middle ground and are less specifically defined. Furthermore, "the statistical map shows a strong relationship which manifests itself in two opposite ways. On the one hand, it shows the link between a traditional family structure and a weak integration of women in the working population (Spain, Ireland), and, on the other hand, it shows a close link between a divided family and the fact women have a paying job, often just part time (Sweden, Denmark)." (SUMMARY IN ENG AND SPA) excerpt

Non-Gaussian statistics and optical rogue waves in stimulated Raman scattering.

PubMed

Monfared, Yashar E; Ponomarenko, Sergey A

2017-03-20

We explore theoretically and numerically optical rogue wave formation in stimulated Raman scattering inside a hydrogen filled hollow core photonic crystal fiber. We assume a weak noisy Stokes pulse input and explicitly construct the input Stokes pulse ensemble using the coherent mode representation of optical coherence theory, thereby providing a link between optical coherence and rogue wave theories. We show that the Stokes pulse peak power probability distribution function (PDF) acquires a long tail in the limit of nearly incoherent input Stokes pulses. We demonstrate a clear link between the PDF tail magnitude and the source coherence time. Thus, the latter can serve as a convenient parameter to control the former. We explain our findings qualitatively using the concepts of statistical granularity and global degree of coherence.

Tricyclic [1,2,4]triazine 1,4-dioxides as hypoxia selective cytotoxins.

PubMed

Hay, Michael P; Hicks, Kevin O; Pchalek, Karin; Lee, Ho H; Blaser, Adrian; Pruijn, Frederik B; Anderson, Robert F; Shinde, Sujata S; Wilson, William R; Denny, William A

2008-11-13

A series of novel tricyclic triazine-di- N-oxides (TTOs) related to tirapazamine have been designed and prepared. A wide range of structural arrangements with cycloalkyl, oxygen-, and nitrogen-containing saturated rings fused to the triazine core, coupled with various side chains linked to either hemisphere, resulted in TTO analogues that displayed hypoxia-selective cytotoxicity in vitro. Optimal rates of hypoxic metabolism and tissue diffusion coefficients were achieved with fused cycloalkyl rings in combination with both the 3-aminoalkyl or 3-alkyl substituents linked to weakly basic soluble amines. The selection was further refined using pharmacokinetic/pharmacodynamic model predictions of the in vivo hypoxic potency (AUC req) and selectivity (HCD) with 12 TTO analogues predicted to be active in vivo, subject to the achievement of adequate plasma pharmacokinetics.

Tricyclic [1,2,4]Triazine 1,4-Dioxides As Hypoxia Selective Cytotoxins

PubMed Central

Hay, Michael P.; Hicks, Kevin O.; Pchalek, Karin; Lee, Ho H.; Blaser, Adrian; Pruijn, Frederik B.; Anderson, Robert F.; Shinde, Sujata S.; Wilson, William R.; Denny, William A.

2009-01-01

A series of novel tricyclic triazine-di-N-oxides (TTOs) related to tirapazamine have been designed and prepared. A wide range of structural arrangements with cycloalkyl, oxygen- and nitrogen-containing saturated rings fused to the triazine core, coupled with various side chains linked to either hemisphere, resulted in TTO analogues that displayed hypoxia-selective cytotoxicity in vitro. Optimal rates of hypoxic metabolism and tissue diffusion coefficients were achieved with fused cycloalkyl rings in combination with both the 3-aminoalkyl or 3-alkyl substituents linked to weakly basic soluble amines. The selection was further refined using pharmacokinetic/pharmacodynamic model predictions of the in vivo hypoxic potency (AUCreq) and selectivity (HCD) with 12 TTO analogues predicted to be active in vivo, subject to the achievement of adequate plasma pharmacokinetics. PMID:18847185

Kinetic chain abnormalities in the athletic shoulder.

PubMed

Sciascia, Aaron; Thigpen, Charles; Namdari, Surena; Baldwin, Keith

2012-03-01

Overhead activities require the shoulder to be exposed to and sustain repetitive loads. The segmental activation of the body's links, known as the kinetic chain, allows this to occur effectively. Proper muscle activation is achieved through generation of energy from the central segment or core, which then transfers the energy to the terminal links of the shoulder, elbow, and hand. The kinetic chain is best characterized by 3 components: optimized anatomy, reproducible efficient motor patterns, and the sequential generation of forces. However, tissue injury and anatomic deficits such as weakness and/or tightness in the leg, pelvic core, or scapular musculature can lead to overuse shoulder injuries. These injuries can be prevented and maladaptations can be detected with a thorough understanding of biomechanics of the kinetic chain as it relates to overhead activity.

Immediate effects of form-class constraints on spoken word recognition

PubMed Central

Magnuson, James S.; Tanenhaus, Michael K.; Aslin, Richard N.

2008-01-01

In many domains of cognitive processing there is strong support for bottom-up priority and delayed top-down (contextual) integration. We ask whether this applies to supra-lexical context that could potentially constrain lexical access. Previous findings of early context integration in word recognition have typically used constraints that can be linked to pair-wise conceptual relations between words. Using an artificial lexicon, we found immediate integration of syntactic expectations based on pragmatic constraints linked to syntactic categories rather than words: phonologically similar “nouns” and “adjectives” did not compete when a combination of syntactic and visual information strongly predicted form class. These results suggest that predictive context is integrated continuously, and that previous findings supporting delayed context integration stem from weak contexts rather than delayed integration. PMID:18675408

7 CFR 1735.30 - Hardship loans.

Code of Federal Regulations, 2012 CFR

2012-01-01

... be used by the Administrator to rank, from high to low, applications that have been determined to.... (v) Distance Learning and Medical Link Facilities. Borrowers will receive 2 points for loan funds included in the application for the purpose of providing distance learning or medical link transmission...

7 CFR 1735.30 - Hardship loans.

Code of Federal Regulations, 2014 CFR

2014-01-01

... be used by the Administrator to rank, from high to low, applications that have been determined to.... (v) Distance Learning and Medical Link Facilities. Borrowers will receive 2 points for loan funds included in the application for the purpose of providing distance learning or medical link transmission...

7 CFR 1735.30 - Hardship loans.

Code of Federal Regulations, 2011 CFR

2011-01-01

... be used by the Administrator to rank, from high to low, applications that have been determined to.... (v) Distance Learning and Medical Link Facilities. Borrowers will receive 2 points for loan funds included in the application for the purpose of providing distance learning or medical link transmission...

7 CFR 1735.30 - Hardship loans.

Code of Federal Regulations, 2013 CFR

2013-01-01

... be used by the Administrator to rank, from high to low, applications that have been determined to.... (v) Distance Learning and Medical Link Facilities. Borrowers will receive 2 points for loan funds included in the application for the purpose of providing distance learning or medical link transmission...

7 CFR 1735.30 - Hardship loans.

Code of Federal Regulations, 2010 CFR

2010-01-01

... be used by the Administrator to rank, from high to low, applications that have been determined to.... (v) Distance Learning and Medical Link Facilities. Borrowers will receive 2 points for loan funds included in the application for the purpose of providing distance learning or medical link transmission...

The Power of Real-World Application

ERIC Educational Resources Information Center

Stam, Brad

2011-01-01

Linked learning transforms students' high school experience by linking a college preparatory course sequence with demanding technical education, and linking real-world experiences with classroom learning to help students gain an advantage in high school, postsecondary education, and careers. With linked learning, students follow industry-themed…

Nilsson's Power Model connecting speed and road trauma: applicability by road type and alternative models for urban roads.

PubMed

Cameron, M H; Elvik, R

2010-11-01

Nilsson (1981) proposed power relationships connecting changes in traffic speeds with changes in road crashes at various levels of injury severity. Increases in fatal crashes are related to the 4(th) power of the increase in mean speed, increases in serious casualty crashes (those involving death or serious injury) according to the 3(rd) power, and increases in casualty crashes (those involving death or any injury) according to the 2(nd) power. Increases in numbers of crash victims at cumulative levels of injury severity are related to the crash increases plus higher powers predicting the number of victims per crash. These relationships are frequently applied in OECD countries to estimate road trauma reductions resulting from expected speed reductions. The relationships were empirically derived based on speed changes resulting from a large number of rural speed limit changes in Sweden during 1967-1972. Nilsson (2004) noted that there had been very few urban speed limit changes studied to test his power model. This paper aims to test the assumption that the model is equally applicable in all road environments. It was found that the road environment is an important moderator of Nilsson's power model. While Nilsson's model appears satisfactory for rural highways and freeways, the model does not appear to be directly applicable to traffic speed changes on urban arterial roads. The evidence of monotonically increasing powers applicable to changes in road trauma at increasing injury severity levels with changes in mean speed is weak. The estimated power applicable to serious casualties on urban arterial roads was significantly less than that on rural highways, which was also significantly less than that on freeways. Alternative models linking the parameters of speed distributions with road trauma are reviewed and some conclusions reached for their use on urban roads instead of Nilsson's model. Further research is needed on the relationships between serious road trauma and urban speeds. 2010 Elsevier Ltd. All rights reserved.

Crystal structures of (2E)-1-(3-bromo-thio-phen-2-yl)-3-(2-meth-oxy-phen-yl)prop-2-en-1-one and (2E)-1-(3-bromo-thio-phen-2-yl)-3-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one.

PubMed

Naik, Vasant S; Shettigar, Venkataraya; Berglin, Tyler S; Coburn, Jillian S; Jasinski, Jerry P; Yathirajan, Hemmige S

2015-08-01

In the mol-ecules of the title compounds, (2E)-1-(3-bromo-thio-phen-2-yl)-3-(2-meth-oxy-phen-yl)prop-2-en-1-one, C14H11BrO2S, (I), which crystallizes in the space group P-1 with four independent mol-ecules in the asymmetric unit (Z' = 8), and (2E)-1-(3-bromo-thio-phen-2-yl)-3-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one, C15H13BrO3S, (II), which crystallizes with Z' = 8 in the space group I2/a, the non-H atoms are nearly coplanar. The mol-ecules of (I) pack with inversion symmetry stacked diagonally along the a-axis direction. Weak C-H⋯Br intra-molecular inter-actions in each of the four mol-ecules in the asymmetric unit are observed. In (II), weak C-H⋯O, bifurcated three-center inter-molecular inter-actions forming dimers along with weak C-H⋯π and π-π stacking inter-actions are observed, linking the mol-ecules into sheets along [001]. A weak C-H⋯Br intra-molecular inter-action is also present. There are no classical hydrogen bonds present in either structure.

Linking potential heat source and sink to urban heat island: Heterogeneous effects of landscape pattern on land surface temperature.

PubMed

Li, Weifeng; Cao, Qiwen; Lang, Kun; Wu, Jiansheng

2017-05-15

Rapid urbanization has significantly contributed to the development of urban heat island (UHI). Regulating landscape composition and configuration would help mitigate the UHI in megacities. Taking Shenzhen, China, as a case study area, we defined heat source and heat sink and identified strong and weak sources as well as strong and weak sinks according to the natural and socioeconomic factors influencing land surface temperature (LST). Thus, the potential thermal contributions of heat source and heat sink patches were differentiated. Then, the heterogeneous effects of landscape pattern on LST were examined by using semiparametric geographically weighted regression (SGWR) models. The results showed that landscape composition has more significant effects on thermal environment than configuration. For a strong source, the percentage of patches has a positive impact on LST. Additionally, when mosaicked with some heat sink, even a small improvement in the degree of dispersion of a strong source helps to alleviate UHI. For a weak source, the percentage and density of patches have positive impacts on LST. For a strong sink, the percentage, density, and degree of aggregation of patches have negative impacts on LST. The effects of edge density and patch shape complexity vary spatially with the fragmentation of a strong sink. Similarly, the impacts of a weak sink are mainly exerted via the characteristics of percent, density, and shape complexity of patches. Copyright © 2017 Elsevier B.V. All rights reserved.

FOOTPRINTS FOR SUSTAINABILITY: THE NEXT STEPS

EPA Science Inventory

This paper discusses the strengths and weaknesses of the ecological footprint as an ecological accounting method, points out research needs for improvement of the analysis, and suggests potential new applications.

Colossal magnetoresistance in amino-functionalized graphene quantum dots at room temperature: manifestation of weak anti-localization and doorway to spintronics

NASA Astrophysics Data System (ADS)

Roy, Rajarshi; Thapa, Ranjit; Kumar, Gundam Sandeep; Mazumder, Nilesh; Sen, Dipayan; Sinthika, S.; Das, Nirmalya S.; Chattopadhyay, Kalyan K.

2016-04-01

In this work, we have demonstrated the signatures of localized surface distortions and disorders in functionalized graphene quantum dots (fGQD) and consequences in magneto-transport under weak field regime (~1 Tesla) at room temperature. Observed positive colossal magnetoresistance (MR) and its suppression is primarily explained by weak anti-localization phenomenon where competitive valley (inter and intra) dependent scattering takes place at room temperature under low magnetic field; analogous to low mobility disordered graphene samples. Furthermore, using ab-initio analysis we show that sub-lattice sensitive spin-polarized ground state exists in the GQD as a result of pz orbital asymmetry in GQD carbon atoms with amino functional groups. This spin polarized ground state is believed to help the weak anti-localization dependent magneto transport by generating more disorder and strain in a GQD lattice under applied magnetic field and lays the premise for future graphene quantum dot based spintronic applications.In this work, we have demonstrated the signatures of localized surface distortions and disorders in functionalized graphene quantum dots (fGQD) and consequences in magneto-transport under weak field regime (~1 Tesla) at room temperature. Observed positive colossal magnetoresistance (MR) and its suppression is primarily explained by weak anti-localization phenomenon where competitive valley (inter and intra) dependent scattering takes place at room temperature under low magnetic field; analogous to low mobility disordered graphene samples. Furthermore, using ab-initio analysis we show that sub-lattice sensitive spin-polarized ground state exists in the GQD as a result of pz orbital asymmetry in GQD carbon atoms with amino functional groups. This spin polarized ground state is believed to help the weak anti-localization dependent magneto transport by generating more disorder and strain in a GQD lattice under applied magnetic field and lays the premise for future graphene quantum dot based spintronic applications. Electronic supplementary information (ESI) available: UV-Vis spectrum of synthesized fGQDs, reconstructed false color surface topographic images from a high-resolution fGQD TEM lattice; Raman spectra with corresponding Breit-Wigner-Fano (BWF) line fitting of `G band' before and after the application of sTMF, spin density distribution (SDD) with different shapes of a functionalized graphene quantum dot, SDD of the main simulated fGQD model obtained using different exchange correlation functional (PW91, RBPE and LDA). Models of (a) two NH2 molecules adsorbed on a graphene sheet (periodic structure), (b) representing corresponding SPDOS are also provided. Charge density distribution (CDD) with two-dimensional side view contour plots of adsorbed -NH2 and O&z.dbd;C-NH2 on GQD lattice and SPDOS of a main fGQD model with 0.2% strain. See DOI: 10.1039/c5nr09292b