Nurse practitioner coverage is associated with a decrease in length of stay in a pediatric chronic ventilator dependent unit

PubMed Central

Rowan, Courtney M; Cristea, A Ioana; Hamilton, Jennifer C; Taylor, Nicole M; Nitu, Mara E; Ackerman, Veda L

2016-01-01

AIM: To hypothesize a dedicated critical care nurse practitioner (NP) is associated with a decreased length of stay (LOS) from a pediatric chronic ventilator dependent unit (PCVDU). METHODS: We retrospectively reviewed patients requiring care in the PCVDU from May 2001 through May 2011 comparing the 5 years prior to the 5 years post implementation of the critical care NP in 2005. LOS and room charges were obtained. RESULTS: The average LOS decreased from a median of 55 d [interquartile range (IQR): 9.8-108.3] to a median of 12 (IQR: 4.0-41.0) with the implementation of a dedicated critical care NP (P < 1.0001). Post implementation of a dedicated NP, a savings of 25738049 in room charges was noted over 5 years. CONCLUSION: Our data demonstrates a critical care NP coverage model in a PCVDU is associated with a significantly reduced LOS demonstrating that the NP is an efficient and likely cost-effective addition to a medically comprehensive service. PMID:27170929

Core verbal working-memory capacity: the limit in words retained without covert articulation.

PubMed

Chen, Zhijian; Cowan, Nelson

2009-07-01

Verbal working memory may combine phonological and conceptual units. We disentangle their contributions by extending a prior procedure (Chen & Cowan, 2005) in which items recalled from lists of previously seen word singletons and of previously learned word pairs depended on the list length in chunks. Here we show that a constant capacity of about 3 chunks holds across list lengths and list types, provided that covert phonological rehearsal is prevented. What remains is a core verbal working-memory capacity.

Studying the Dependency of Interfacial Formation with Carbon Nanotube

DTIC Science & Technology

2014-08-27

PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND...duration of this project toward understanding the interfacial formation and dependency on SWNT and its relationship to the nanotube length. SECTION II...obtained from Kuraray America Inc. Dimethyl sulfoxide (DMSO) was purchased from Sigma -Aldrich Corporation (CAS# 67-68-5, lot# 472301). Methanol was

Laser induced damage thresholds and laser safety levels. Do the units of measurement matter?

NASA Astrophysics Data System (ADS)

Wood, R. M.

1998-04-01

The commonly used units of measurement for laser induced damage are those of peak energy or power density. However, the laser induced damage thresholds, LIDT, of all materials are well known to be absorption, wavelength, spot size and pulse length dependent. As workers using these values become divorced from the theory it becomes increasingly important to use the correct units and to understand the correct scaling factors. This paper summarizes the theory and highlights the danger of using the wrong LIDT units in the context of potentially hazardous materials, laser safety eyewear and laser safety screens.

Upscaling of Solute Transport in Heterogeneous Media with Non-uniform Flow and Dispersion Fields

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

Xu, Zhijie; Meakin, Paul

2013-10-01

An analytical and computational model for non-reactive solute transport in periodic heterogeneous media with arbitrary non-uniform flow and dispersion fields within the unit cell of length ε is described. The model lumps the effect of non-uniform flow and dispersion into an effective advection velocity Ve and an effective dispersion coefficient De. It is shown that both Ve and De are scale-dependent (dependent on the length scale of the microscopic heterogeneity, ε), dependent on the Péclet number Pe, and on a dimensionless parameter α that represents the effects of microscopic heterogeneity. The parameter α, confined to the range of [-0.5, 0.5]more » for the numerical example presented, depends on the flow direction and non-uniform flow and dispersion fields. Effective advection velocity Ve and dispersion coefficient De can be derived for any given flow and dispersion fields, and . Homogenized solutions describing the macroscopic variations can be obtained from the effective model. Solutions with sub-unit-cell accuracy can be constructed by homogenized solutions and its spatial derivatives. A numerical implementation of the model compared with direct numerical solutions using a fine grid, demonstrated that the new method was in good agreement with direct solutions, but with significant computational savings.« less

Adaptive upstream optical power adjustment depending on required power budget in PON access

NASA Astrophysics Data System (ADS)

Yeh, C. H.; Chow, C. W.; Liu, Y. L.

2012-11-01

According to the present passive optical network (PON) standard, the fiber transmission lengths are from 500 m to 20 km between the optical line terminal (OLT) and different optical network units (ONUs). It will result in difference power losses (ΔPloss) from 4 to 5 dB. Hence, we propose to adjust adaptively the output optical power of the upstream laser diode (LD) depending on the different fiber lengths. With the different fiber transmission lengths, we can properly adjust the bias current and modulation index of upstream LD for energy-saving. We characterize and analyze experimentally the relationship of output optical power and modulation amplitude Vamp under different fiber transmissions in PON access. Moreover, due to the adaptive power control of upstream signal, the optical upstream equalization also can be retrieved with power variation of 1.1 dB in this experiment.

Postfledging nest dependence period for bald eagles in Florida

USGS Publications Warehouse

Wood, P.B.; Collopy, Michael W.; Sekerak, C.M.

1998-01-01

We studied the postfledging dependency period in bald eagles (Haliaeetus leucocephalus), a little studied but important period in the life cycle of avian species. Bald eagles in Florida had a postfledging dependency period of 4-11 weeks (15-22 weeks old). The length of the dependency period did not vary by year of study, sex, number of fledgings, timing of fledging, or hatch order (P > 0.05). Mean distance fledglings ranged from the nest increased with age, but they were observed in the nest or nest tree throughout the postfledging dependency period. Distance from the nest did not vary by sex, number of fledglings, or timing of fledging (P > 0.05). Over 80% of the fledgling observations were within 229 m of the nest. The boundary of the primary protection zone specified in the bald eagle habitat management guidelines for the southeastern United States is 229 m. Restrictions on human disturbance around nest sites should remain in place during the postfledging dependency period because of the close association of fledglings with the nest site. Restrictions also should be flexible because of the varying length of the dependency period.

Determination of the paraxial focal length using Zernike polynomials over different apertures

NASA Astrophysics Data System (ADS)

Binkele, Tobias; Hilbig, David; Henning, Thomas; Fleischmann, Friedrich

2017-02-01

The paraxial focal length is still the most important parameter in the design of a lens. As presented at the SPIE Optics + Photonics 2016, the measured focal length is a function of the aperture. The paraxial focal length can be found when the aperture approaches zero. In this work, we investigate the dependency of the Zernike polynomials on the aperture size with respect to 3D space. By this, conventional wavefront measurement systems that apply Zernike polynomial fitting (e.g. Shack-Hartmann-Sensor) can be used to determine the paraxial focal length, too. Since the Zernike polynomials are orthogonal over a unit circle, the aperture used in the measurement has to be normalized. By shrinking the aperture and keeping up with the normalization, the Zernike coefficients change. The relation between these changes and the paraxial focal length are investigated. The dependency of the focal length on the aperture size is derived analytically and evaluated by simulation and measurement of a strong focusing lens. The measurements are performed using experimental ray tracing and a Shack-Hartmann-Sensor. Using experimental ray tracing for the measurements, the aperture can be chosen easily. Regarding the measurements with the Shack-Hartmann- Sensor, the aperture size is fixed. Thus, the Zernike polynomials have to be adapted to use different aperture sizes by the proposed method. By doing this, the paraxial focal length can be determined from the measurements in both cases.

Chain Length Dependence of Energies of Electron and Triplet Polarons in Oligofluorenes

DOE PAGES

Chen, Hung Cheng; Sreearunothai, Paiboon; Cook, Andrew R.; ...

2017-03-01

Bimolecular equilibria measured the one-electron reduction potentials and triplet free energies (ΔG° T) of oligo(9,9-dihexyl)fluorenes and a polymer with lengths of n = 1–10 and 57 repeat units. We can accurately measure one-electron potentials electrochemically only for the shorter oligomers. Starting at n = 1 the free energies change rapidly with increasing length and become constant for lengths longer than the delocalization length. Both the reduction potentials and triplet energies can be understood as the sum of a free energy for a fixed polaron and a positional entropy. Furthermore, the positional entropy increases gradually with length beyond the delocalization lengthmore » due to the possible occupation sites of the charge or the triplet exciton. Our results reinforce the view that charges and triplet excitons in conjugated chains exist as polarons and find that positional entropy can replace a popular empirical model of the energetics.« less

Muscle structure, sarcomere length and influences on meat quality: A review.

PubMed

Ertbjerg, Per; Puolanne, Eero

2017-10-01

The basic contractile unit of muscle, the sarcomere, will contract as the muscle goes into rigor post-mortem. Depending on the conditions, such as the rate of pH decline, the cooling rate and the mechanical restraints on the muscles, this longitudinal shortening will result in various post-mortem sarcomere lengths as well as lateral differences in the distances between the myosin and actin filaments. This shortening is underlying the phenomena described as rigor contraction, thaw rigor, cold shortening and heat shortening. The shortening in combination with the molecular architecture of the sarcomere as defined by the myosin filaments and their S-1 and S-2 units, the interaction with the actin filaments, and the boundaries formed by the Z-disks will subsequently influence basic meat quality traits including tenderness and water-holding capacity. Biochemical reactions from proteolysis and glycogen metabolism interrelate with the sarcomere length in a complex manner. The sarcomere length is also influencing the eating quality of cooked meat and the water-holding in meat products. Copyright © 2017 Elsevier Ltd. All rights reserved.

Measurement of intercolumnar forces between parallel guanosine four-stranded helices.

PubMed Central

Mariani, P; Saturni, L

1996-01-01

The deoxyguanosine-5'-monophosphate in aqueous solution self-associates into stable structures, which include hexagonal and cholesteric columnar phases. The structural unit is a four-stranded helix, composed of a stacked array of Hoogsteen-bonded guanosine quartets. We have measured by osmotic stress method the force per unit length versus interaxial distance between helices in the hexagonal phase under various ionic conditions. Two contributions have been recognized: the first one is purely electrostatic, is effective at large distances, and shows a strong dependence on the salt concentration of the solution. The second contribution is short range, dominates at interaxial separations smaller than about 30-32 A, and rises steeply as the columns approach each other, preventing the coalescence of the helices. This repulsion has an exponential nature and shows a magnitude and a decay length insensitive to the ionic strength of the medium. Because these features are distinctive of the hydration force detected between phospholipid bilayers or between several linear macromolecules (DNA, polysaccharides, collagen), we conclude that the dominant force experienced by deoxyguanosine helices approaching contact is hydration repulsion. The observed decay length of about 0.7 A has been rationalized to emerge from the coupling between the 3-A decay length of water solvent and the helically ordered structure of the hydrophilic groups on the opposing surfaces. The present results agree with recent measurements, also showing the dependence of the hydration force decay on the structure of interacting surfaces and confirm the correlations between force and structure. Images FIGURE 1 PMID:8744324

Strength of visual interpolation depends on the ratio of physically specified to total edge length.

PubMed

Shipley, T F; Kellman, P J

1992-07-01

We report four experiments in which the strength of edge interpolation in illusory figure displays was tested. In Experiment 1, we investigated the relative contributions of the lengths of luminance-specified edges and the gaps between them to perceived boundary clarity as measured by using a magnitude estimation procedure. The contributions of these variables were found to be best characterized by a ratio of the length of luminance-specified contour to the length of the entire edge (specified plus interpolated edge). Experiment 2 showed that this ratio predicts boundary clarity for a wide range of ratio values and display sizes. There was no evidence that illusory figure boundaries are clearer in displays with small gaps than they are in displays with larger gaps and equivalent ratios. In Experiment 3, using a more sensitive pairwise comparison paradigm, we again found no such effect. Implications for boundary interpolation in general, including perception of partially occluded objects, are discussed. The dependence of interpolation on the ratio of physically specified edges to total edge length has the desirable ecological consequence that unit formation will not change with variations in viewing distance.

Length-dependence of intramolecular electron transfer in σ-bonded rigid molecular rods: an ab initio molecular orbital study

NASA Astrophysics Data System (ADS)

Pati, Ranjit; Karna, Shashi P.

2002-01-01

The dependence of electron transfer (ET) coupling element, VAB, on the length of rigid-rod-like systems consisting of bicyclo[1.1.1]pentane (BCP), cubane (CUB), and bicyclo[2.2.2]octane (BCO) monomers, has been investigated with the use of ab initio Hartree-Fock (HF) method employing Marcus-Hush two-state (TS) model. The value of VAB decreases exponentially with increase in the number of the cage units of the σ-bonded molecules. The calculated decay constant, β, shows good agreement with previously reported data. For molecular length⩾15 Å, the value of VAB becomes negligibly small, suggesting complete suppression of the through bond direct tunneling contribution to ET process.

Line length dependencies in interconnect optimization

NASA Astrophysics Data System (ADS)

Kadoch, Daniel; Duane, Michael; Lee, Yohan

1997-09-01

Metal line delay has become increasingly important for ULSI devices. Numerous expressions and software tools have been developed to describe interconnect delay as a function of the geometry and layout. Although many of these formulas have line length effects, this has not been explored in depth. Most software tools are either geared towards circuit designers, or involve more complex and CPU-intensive 3D modeling. In this work, PISCES (a 2D device simulator) was used to extract metal capacitance per unit length. We extend this approach for various lengths by creating a ladder network of the RC components and simulating in SPICE, or using simple closed-form Elmore delay equations. A new key result is that there are optimum metal line width/space for a fixed pitch and height/space ratios that are metal length dependent. For metal lines shorter than about 1500 micrometers , it is better to have narrower metal lines, and for lengths less than 500 micrometers , shrinking metal height is desirable because the penalty in resistance is more than compensated by the decrease in capacitance. For longer lines, the time delay is dominated by resistance, and wider, taller lines are better. Increasing metal spacing or reducing dielectric constant were beneficial for both long and short metal lines.

Charge transfer fluorescence and 34 nm exciton diffusion length in polymers with electron acceptor end traps

DOE PAGES

Zaikowski, Lori; Mauro, Gina; Bird, Matthew; ...

2014-12-22

Photoexcitation of conjugated poly-2,7-(9,9-dihexylfluorene) polyfluorenes with naphthylimide (NI) and anthraquinone (AQ) electron-acceptor end traps produces excitons that form charge transfer states at the end traps. Intramolecular singlet exciton transport to end traps was examined by steady state fluorescence for polyfluorenes of 17 to 127 repeat units in chloroform, dimethylformamide (DMF), tetrahydrofuran (THF), and p-xylene. End traps capture excitons and form charge transfer (CT) states at all polymer lengths and in all solvents. The CT nature of the end-trapped states is confirmed by their fluorescence spectra, solvent and trap group dependence and DFT descriptions. Quantum yields of CT fluorescence are asmore » large as 46%. This strong CT emission is understood in terms of intensity borrowing. Energies of the CT states from onsets of the fluorescence spectra give the depths of the traps which vary with solvent polarity. For NI end traps the trap depths are 0.06 (p-xylene), 0.13 (THF) and 0.19 eV (CHCl 3). For AQ, CT fluorescence could be observed only in p-xylene where the trap depth is 0.27 eV. Quantum yields, emission energies, charge transfer energies, solvent reorganization and vibrational energies were calculated. Fluorescence measurements on chains >100 repeat units indicate that end traps capture ~50% of the excitons, and that the exciton diffusion length L D =34 nm, which is much larger than diffusion lengths reported in polymer films or than previously known for diffusion along isolated chains. As a result, the efficiency of exciton capture depends on chain length, but not on trap depth, solvent polarity or which trap group is present.« less

Diradicals acting through diamagnetic phenylene vinylene bridges: Raman spectroscopy as a probe to characterize spin delocalization

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

González, Sandra Rodríguez; Nieto-Ortega, Belén; González Cano, Rafael C.

2014-04-28

We present a complete Raman spectroscopic study in two structurally well-defined diradical species of different lengths incorporating oligo p-phenylene vinylene bridges between two polychlorinated triphenylmethyl radical units, a disposition that allows sizeable conjugation between the two radicals through and with the bridge. The spectroscopic data are interpreted and supported by quantum chemical calculations. We focus the attention on the Raman frequency changes, interpretable in terms of: (i) bridge length (conjugation length); (ii) bridge conformational structure; and (iii) electronic coupling between the terminal radical units with the bridge and through the bridge, which could delineate through-bond spin polarization, or spin delocalization.more » These items are addressed by using the “oligomer approach” in conjunction with pressure and temperature dependent Raman spectroscopic data. In summary, we have attempted to translate the well-known strategy to study the electron (charge) structure of π−conjugated molecules by Raman spectroscopy to the case of electron (spin) interactions via the spin delocalization mechanism.« less

Nonlinear susceptibilities of finite conjugated organic polymers

NASA Technical Reports Server (NTRS)

Beratan, David N.; Onuchic, Jose Nelson; Perry, Joseph W.

1987-01-01

Tight-binding calculations of the length dependence of the third-order molecular hyperpolarizability for polyenes and polyynes are reported. The pi-electron wave functions were determined by exploiting the limited translational symmetry of the molecules. Perturbation theory was used to calculate the longitudinal component of the electronic nonresonant hyperpolarizability. This is the first two-'band' calculation of third-order hyperpolarizabilities on finite pi-electron systems of varying length. In contrast to the results of the one-'band' models, the hyperpolarizability densities increase rapidly and then, after about 10-15 repeating units, approach an asymptotic value.

Efficient analysis of mode profiles in elliptical microcavity using dynamic-thermal electron-quantum medium FDTD method.

PubMed

Khoo, E H; Ahmed, I; Goh, R S M; Lee, K H; Hung, T G G; Li, E P

2013-03-11

The dynamic-thermal electron-quantum medium finite-difference time-domain (DTEQM-FDTD) method is used for efficient analysis of mode profile in elliptical microcavity. The resonance peak of the elliptical microcavity is studied by varying the length ratio. It is observed that at some length ratios, cavity mode is excited instead of whispering gallery mode. This depicts that mode profiles are length ratio dependent. Through the implementation of the DTEQM-FDTD on graphic processing unit (GPU), the simulation time is reduced by 300 times as compared to the CPU. This leads to an efficient optimization approach to design microcavity lasers for wide range of applications in photonic integrated circuits.

Tunable two-dimensional acoustic meta-structure composed of funnel-shaped unit cells with multi-band negative acoustic property

NASA Astrophysics Data System (ADS)

Cho, Sungjin; Kim, Boseung; Min, Dongki; Park, Junhong

2015-10-01

This paper presents a two-dimensional heat-exhaust and sound-proof acoustic meta-structure exhibiting tunable multi-band negative effective mass density. The meta-structure was composed of periodic funnel-shaped units in a square lattice. Each unit cell operates simultaneously as a Helmholtz resonator (HR) and an extended pipe chamber resonator (EPCR), leading to a negative effective mass density creating bandgaps for incident sound energy dissipation without transmission. This structure allowed large heat-flow through the cross-sectional area of the extended pipe since the resonance was generated by acoustic elements without using solid membranes. The pipes were horizontally directed to a flow source to enable small flow resistance for cooling. Measurements of the sound transmission were performed using a two-load, four-microphone method for a unit cell and small reverberation chamber for two-dimensional panel to characterize the acoustic performance. The effective mass density showed significant frequency dependent variation exhibiting negative values at the specific bandgaps, while the effective bulk modulus was not affected by the resonator. Theoretical models incorporating local resonances in the multiple resonator units were proposed to analyze the noise reduction mechanism. The acoustic meta-structure parameters to create broader frequency bandgaps were investigated using the theoretical model. The negative effective mass density was calculated to investigate the creation of the bandgaps. The effects of design parameters such as length, cross-sectional area, and volume of the HR; length and cross-sectional area of the EPCR were analyzed. To maximize the frequency band gap, the suggested acoustic meta-structure panel, small neck length, and cross-sectional area of the HR, large EPCR length was advantageous. The bandgaps became broader when the two resonant frequencies were similar.

Size Dependence of Residual Thermal Stresses in Micro Multilayer Ceramic Capacitors by Using Finite Element Unit Cell Model Including Strain Gradient Effect

NASA Astrophysics Data System (ADS)

Jiang, W. G.; Xiong, C. A.; Wu, X. G.

2013-11-01

The residual thermal stresses induced by the high-temperature sintering process in multilayer ceramic capacitors (MLCCs) are investigated by using a finite-element unit cell model, in which the strain gradient effect is considered. The numerical results show that the residual thermal stresses depend on the lateral margin length, the thickness ratio of the dielectrics layer to the electrode layer, and the MLCC size. At a given thickness ratio, as the MLCC size is scaled down, the peak shear stress reduces significantly and the normal stresses along the length and thickness directions change slightly with the decrease in the ceramic layer thickness t d as t d > 1 μm, but as t d < 1 μm, the normal stress components increase sharply with the increase in t d. Thus, the residual thermal stresses induced by the sintering process exhibit strong size effects and, therefore, the strain gradient effect should be taken into account in the design and evaluation of MLCC devices

Neonates and Infants Discharged Home Dependent on Medical Technology: Characteristics and Outcomes.

PubMed

Toly, Valerie Boebel; Musil, Carol M; Bieda, Amy; Barnett, Kimberly; Dowling, Donna A; Sattar, Abdus

2016-10-01

Preterm neonates and neonates with complex conditions admitted to a neonatal intensive care unit (NICU) may require medical technology (eg, supplemental oxygen, feeding tubes) for their continued survival at hospital discharge. Medical technology introduces another layer of complexity for parents, including specialized education about neonatal assessment and operation of technology. The transition home presents a challenge for parents and has been linked with greater healthcare utilization. To determine incidence, characteristics, and healthcare utilization outcomes (emergency room visits, rehospitalizations) of technology-dependent neonates and infants following initial discharge from the hospital. This descriptive, correlational study used retrospective medical record review to examine technology-dependent neonates (N = 71) upon discharge home. Study variables included demographic characteristics, hospital length of stay, and type of medical technology used. Analysis of neonates (n = 22) with 1-year postdischarge data was conducted to identify relationships with healthcare utilization. Descriptive and regression analyses were performed. Approximately 40% of the technology-dependent neonates were between 23 and 26 weeks' gestation, with birth weight of less than 1000 g. Technologies used most frequently were supplemental oxygen (66%) and feeding tubes (46.5%). The mean total hospital length of stay for technology-dependent versus nontechnology-dependent neonates was 108.6 and 25.7 days, respectively. Technology-dependent neonates who were female, with a gastrostomy tube, or with longer initial hospital length of stay were at greater risk for rehospitalization. Assessment and support of families, particularly mothers of technology-dependent neonates following initial hospital discharge, are vital. Longitudinal studies to determine factors affecting long-term outcomes of technology-dependent infants are needed.

Optimizing the use of a sensor resource for opponent polarization coding

PubMed Central

Heras, Francisco J.H.

2017-01-01

Flies use specialized photoreceptors R7 and R8 in the dorsal rim area (DRA) to detect skylight polarization. R7 and R8 form a tiered waveguide (central rhabdomere pair, CRP) with R7 on top, filtering light delivered to R8. We examine how the division of a given resource, CRP length, between R7 and R8 affects their ability to code polarization angle. We model optical absorption to show how the length fractions allotted to R7 and R8 determine the rates at which they transduce photons, and correct these rates for transduction unit saturation. The rates give polarization signal and photon noise in R7, and in R8. Their signals are combined in an opponent unit, intrinsic noise added, and the unit’s output analysed to extract two measures of coding ability, number of discriminable polarization angles and mutual information. A very long R7 maximizes opponent signal amplitude, but codes inefficiently due to photon noise in the very short R8. Discriminability and mutual information are optimized by maximizing signal to noise ratio, SNR. At lower light levels approximately equal lengths of R7 and R8 are optimal because photon noise dominates. At higher light levels intrinsic noise comes to dominate and a shorter R8 is optimum. The optimum R8 length fractions falls to one third. This intensity dependent range of optimal length fractions corresponds to the range observed in different fly species and is not affected by transduction unit saturation. We conclude that a limited resource, rhabdom length, can be divided between two polarization sensors, R7 and R8, to optimize opponent coding. We also find that coding ability increases sub-linearly with total rhabdom length, according to the law of diminishing returns. Consequently, the specialized shorter central rhabdom in the DRA codes polarization twice as efficiently with respect to rhabdom length than the longer rhabdom used in the rest of the eye. PMID:28316880

Stigma predicts residential treatment length for substance use disorder

PubMed Central

Luoma, Jason B.; Kulesza, Magdalena; Hayes, Steven C.; Kohlenberg, Barbara; Larimer, Mary

2016-01-01

Background Stigma has been suggested as a possible contributor to the high rates of treatment attrition in substance-dependent individuals, but no published empirical studies have examined this association. Objectives The present paper assessed the relationship between baseline stigma variables and length of treatment stay in a sample of patients in a residential addictions treatment unit. Methods The relationship between baseline stigma variables (self-stigma, enacted stigma, and shame) and length of stay for participants (n = 103) in a residential addictions treatment unit was examined. Results Higher self-stigma predicted longer stay in residential addictions treatment, even after controlling for age, marital status, race, overall mental health, social support, enacted stigma, and internalized shame. However, other stigma variables (i.e. internalized shame, stigma-related rejection) did not reliably predict length of treatment stay. Conclusion These results are consistent with other findings suggesting that people with higher self-stigma may have a lowered sense of self-efficacy and heightened fear of being stigmatized and therefore retreat into more protected settings such as residential treatment, potentially resulting in higher treatment costs. Specialized clinical interventions may be necessary to help participants cope with reduced self-efficacy and fear of being stigmatized. PMID:24766087

Exploring the prevalence and variance of cognitive impairment, pain, neuropsychiatric symptoms and ADL dependency among persons living in nursing homes; a cross-sectional study.

PubMed

Björk, Sabine; Juthberg, Christina; Lindkvist, Marie; Wimo, Anders; Sandman, Per-Olof; Winblad, Bengt; Edvardsson, David

2016-08-22

Earlier studies in nursing homes show a high prevalence of cognitive impairment, dependency in activities of daily living (ADL), pain, and neuropsychiatric symptoms among residents. The aim of this study was to explore the prevalence of the above among residents in a nationally representative sample of Swedish nursing homes, and to investigate whether pain and neuropsychiatric symptoms differ in relation to gender, cognitive function, ADL-capacity, type of nursing-home unit and length of stay. Cross-sectional data from 188 randomly selected nursing homes were collected. A total of 4831 residents were assessed for cognitive and ADL function, pain and neuropsychiatric symptoms. Data were analysed using descriptive statistics and the chi-square test. The results show the following: the prevalence of cognitive impairment was 67 %, 56 % of residents were ADL-dependent, 48 % exhibited pain and 92 % exhibited neuropsychiatric symptoms. The prevalence of pain did not differ significantly between male and female residents, but pain was more prevalent among cognitively impaired and ADL-dependent residents. Pain prevalence was not significantly different between residents in special care units for people with dementia (SCU) and general units, or between shorter-and longer-stay residents. Furthermore, the prevalence of neuropsychiatric symptoms did not differ significantly between male and female residents, between ADL capacities or in relation to length of stay. However, residents with cognitive impairment and residents in SCUs had a significantly higher prevalence of neuropsychiatric symptoms than residents without cognitive impairment and residents in general units. The prevalence rates ascertained in this study could contribute to a greater understanding of the needs of nursing-home residents, and may provide nursing home staff and managers with trustworthy assessment scales and benchmark values for further quality assessment purposes, clinical development work and initiating future nursing assessments.

Estimating the board foot to cubic foot ratio

Treesearch

Steve P. Verrill; Victoria L. Herian; Henry N. Spelter

2004-01-01

Certain issues in recent softwood lumber trade negotiations have centered on the method for converting estimates of timber volumes reported in cubic meters to board feet. Such conversions depend on many factors; three of the most important of these are log length, diameter, and taper. Average log diameters vary by region and have declined in the western United States...

Custom map projections for regional groundwater models

USGS Publications Warehouse

Kuniansky, Eve L.

2017-01-01

For regional groundwater flow models (areas greater than 100,000 km2), improper choice of map projection parameters can result in model error for boundary conditions dependent on area (recharge or evapotranspiration simulated by application of a rate using cell area from model discretization) and length (rivers simulated with head-dependent flux boundary). Smaller model areas can use local map coordinates, such as State Plane (United States) or Universal Transverse Mercator (correct zone) without introducing large errors. Map projections vary in order to preserve one or more of the following properties: area, shape, distance (length), or direction. Numerous map projections are developed for different purposes as all four properties cannot be preserved simultaneously. Preservation of area and length are most critical for groundwater models. The Albers equal-area conic projection with custom standard parallels, selected by dividing the length north to south by 6 and selecting standard parallels 1/6th above or below the southern and northern extent, preserves both area and length for continental areas in mid latitudes oriented east-west. Custom map projection parameters can also minimize area and length error in non-ideal projections. Additionally, one must also use consistent vertical and horizontal datums for all geographic data. The generalized polygon for the Floridan aquifer system study area (306,247.59 km2) is used to provide quantitative examples of the effect of map projections on length and area with different projections and parameter choices. Use of improper map projection is one model construction problem easily avoided.

The relationship between organizational culture and family satisfaction in critical care.

PubMed

Dodek, Peter M; Wong, Hubert; Heyland, Daren K; Cook, Deborah J; Rocker, Graeme M; Kutsogiannis, Demetrios J; Dale, Craig; Fowler, Robert; Robinson, Sandra; Ayas, Najib T

2012-05-01

Family satisfaction with critical care is influenced by a variety of factors. We investigated the relationship between measures of organizational and safety culture, and family satisfaction in critical care. We further explored differences in this relationship depending on intensive care unit survival status and length of intensive care unit stay of the patient. Cross-sectional surveys. Twenty-three tertiary and community intensive care units within three provinces in Canada. One thousand two-hundred eighty-five respondents from 2374 intensive care unit clinical staff, and 880 respondents from 1381 family members of intensive care unit patients. None. Intensive care unit staff completed the Organization and Management of Intensive Care Units survey and the Hospital Survey on Patient Safety Culture. Family members completed the Family Satisfaction in the Intensive Care Unit 24, a validated survey of family satisfaction. A priori, we analyzed adjusted relationships between each domain score from the culture surveys and either satisfaction with care or satisfaction with decision-making for each of four subgroups of family members according to patient descriptors: intensive care unit survivors who had length of intensive care unit stay <14 days or >14 days, and intensive care unit nonsurvivors who had length of stay <14 days or ≥14 days. We found strong positive relationships between most domains of organizational and safety culture, and satisfaction with care or decision-making for family members of intensive care unit nonsurvivors who spent at least 14 days in the intensive care unit. For the other three groups, there were only a few weak relationships between domains of organizational and safety culture and family satisfaction. Our findings suggest that the effect of organizational culture on care delivery is most easily detectable by family members of the most seriously ill patients who interact frequently with intensive care unit staff, who are intensive care unit nonsurvivors, and who spend a longer time in the intensive care unit. Positive relationships between measures of organizational and safety culture and family satisfaction suggest that by improving organizational culture, we may also improve family satisfaction.

Stability of polyelectrolyte-coated iron nanoparticles for T2-weighted magnetic resonance imaging

NASA Astrophysics Data System (ADS)

McGrath, Andrew J.; Dolan, Ciaran; Cheong, Soshan; Herman, David A. J.; Naysmith, Briar; Zong, Fangrong; Galvosas, Petrik; Farrand, Kathryn J.; Hermans, Ian F.; Brimble, Margaret; Williams, David E.; Jin, Jianyong; Tilley, Richard D.

2017-10-01

Iron nanoparticles are highly-effective magnetic nanoparticles for T2 magnetic resonance imaging (MRI). However, the stability of their magnetic properties is dependent on good protection of the iron core from oxidation in aqueous media. Here we report the synthesis of custom-synthesized phosphonate-grafted polyelectrolytes (PolyM3) of various chain lengths, for efficient coating of iron nanoparticles with a native iron oxide shell. The size of the nanoparticle-polyelectrolyte assemblies was investigated by transmission electron microscopy and dynamic light scattering, while surface attachment was confirmed by Fourier transform infrared spectroscopy. Low cytotoxicity was observed for each of the nanoparticle-polyelectrolyte ("Fe-PolyM3") assemblies, with good cell viability (>80%) remaining up to 100 μg mL-1 Fe in HeLa cells. When applied in T2-weighted MRI, corresponding T2 relaxivities (r2) of the Fe-PolyM3 assemblies were found to be dependent on the chain length of the polyelectrolyte. A significant increase in contrast was observed when polyelectrolyte chain length was increased from 6 to 65 repeating units, implying a critical chain length required for stabilization of the α-Fe nanoparticle core.

Dynamic Quantum Allocation and Swap-Time Variability in Time-Sharing Operating Systems.

ERIC Educational Resources Information Center

Bhat, U. Narayan; Nance, Richard E.

The effects of dynamic quantum allocation and swap-time variability on central processing unit (CPU) behavior are investigated using a model that allows both quantum length and swap-time to be state-dependent random variables. Effective CPU utilization is defined to be the proportion of a CPU busy period that is devoted to program processing, i.e.…

Emergence of gamma motor activity in an artificial neural network model of the corticospinal system.

PubMed

Grandjean, Bernard; Maier, Marc A

2017-02-01

Muscle spindle discharge during active movement is a function of mechanical and neural parameters. Muscle length changes (and their derivatives) represent its primary mechanical, fusimotor drive its neural component. However, neither the action nor the function of fusimotor and in particular of γ-drive, have been clearly established, since γ-motor activity during voluntary, non-locomotor movements remains largely unknown. Here, using a computational approach, we explored whether γ-drive emerges in an artificial neural network model of the corticospinal system linked to a biomechanical antagonist wrist simulator. The wrist simulator included length-sensitive and γ-drive-dependent type Ia and type II muscle spindle activity. Network activity and connectivity were derived by a gradient descent algorithm to generate reciprocal, known target α-motor unit activity during wrist flexion-extension (F/E) movements. Two tasks were simulated: an alternating F/E task and a slow F/E tracking task. Emergence of γ-motor activity in the alternating F/E network was a function of α-motor unit drive: if muscle afferent (together with supraspinal) input was required for driving α-motor units, then γ-drive emerged in the form of α-γ coactivation, as predicted by empirical studies. In the slow F/E tracking network, γ-drive emerged in the form of α-γ dissociation and provided critical, bidirectional muscle afferent activity to the cortical network, containing known bidirectional target units. The model thus demonstrates the complementary aspects of spindle output and hence γ-drive: i) muscle spindle activity as a driving force of α-motor unit activity, and ii) afferent activity providing continuous sensory information, both of which crucially depend on γ-drive.

Photophysical and morphological implications of single-strand conjugated polymer folding in solution

DOE PAGES

Fauvell, Thomas J.; Zheng, Tianyue; Jackson, Nicholas E.; ...

2016-04-08

Organic semiconductors have garnered substantial interest in optoelectronics, but their device performances exhibit strong dependencies on material crystallinity and packing. In an effort to understand the interactions dictating the morphological and photophysical properties of a high-performing photovoltaic polymer, PTB7, a series of short oligomers and low molecular weight polymers of PTB7 were synthesized. Chain-length dependent optical studies of these oligomers demonstrate that PTB7’s low-energy visible absorption is largely due to self-aggregation-induced ordering, rather than in-chain charge transfer, as previously thought. By examining molecular weight and concentration dependent optical properties, supplemented by molecular dynamics simulations, we attribute polymeric PTB7’s unique midgapmore » fluorescence and concentration independent absorption spectrum to an interplay between low molecular weight unaggregated strands and high-molecular weight self-aggregated (folded) strands. Specifically, we propose that the onset of PTB7 self-folding occurs between 7 and 13 repeat units, but the aggregates characteristic of polymeric PTB7 only develop at lengths of ~30 repeat units. Atomistic molecular dynamics simulations of PTB7 corroborate these conclusions, and a simple relation is proposed which quantifies the free-energy of conjugated polymer folding. Lastly, this study provides detailed guidance in the design of intra- and interchain contributions to the photophysical and morphological properties of polymeric semiconductors.« less

Structure and Dynamics of Polymers in Cylindrical Nanoconfinement: A Molecular Dynamics Study

NASA Astrophysics Data System (ADS)

Pressly, James; Riggleman, Robert; Winey, Karen

The structure and dynamics of polymers under nanoconfinement is critical for understanding how polymers behave in applications from hydraulic fracking to fabricating integrated circuits. We previously used simulations to explore the effect of the diameter of cylindrical pores (d = 10-40 σ, where σ is the unit length in reduced units) on polymer end-to-end distance (Ree,perp, Ree,par) , entanglement density, melt diffusion coefficient (D), and local relaxation time (τperp, τpar) at fixed polymer chain length (N = 350). These studies found D, Ree,par, and τperp increased with increasing confinement while entanglement density, Ree,perp, and τpar decreased. Experiments also found that D increased but to a lesser extent. Here, we examine the molecular weight dependence of these properties using N = 25, 50, 100, 200, 350, and 500 confined to pores of diameter 14 σ to examine a range of confinements. Our preliminary results show that as N increases D and Ree,par, increase as well, relative to the unconfined state, while entanglement density and Ree,perp decrease, consistent with our previous work. Interestingly, τ is shown to be independent of chain length indicating the impact of confinement imposed by reducing pore diameter is distinct from that imposed by increasing chain length.

Cross-language diversity, head-direction and grammars. Comment on "Dependency distance: A new perspective on syntactic patterns in natural languages" by Haitao Liu et al.

NASA Astrophysics Data System (ADS)

Hudson, Richard

2017-07-01

This paper [4] - referred to below as 'LXL' - is an excellent example of cross-disciplinary work which brings together three very different disciplines, each with its different methods: quantitative computational linguistics (exploring big data), psycholinguistics (using experiments with human subjects) and theoretical linguistics (building models based on language descriptions). The measured unit is the dependency between two words, as defined by theoretical linguistics, and the question is how the length of this dependency affects the choices made by writers, as revealed in big data from a wide range of languages.

Caffeine and length dependence of staircase potentiation in skeletal muscle.

PubMed

Rassier, D E; Tubman, L A; MacIntosh, B R

1998-01-01

Skeletal muscle sensitivity to Ca2+ is greater at long lengths, and this results in an optimal length for twitch contractions that is longer than optimal length for tetanic contractions. Caffeine abolishes this length dependence of Ca2+ sensitivity. Muscle length (ML) also affects the degree of staircase potentiation. Since staircase potentiation is apparently caused by an increased Ca2+ sensitivity of the myofilaments, we tested the hypothesis that caffeine depresses the length dependence of staircase potentiation. In situ isometric twitch contractions of rat gastrocnemius muscle before and after 10 s of 10-Hz stimulation were analyzed at seven different lengths to evaluate the length dependence of staircase potentiation. In the absence of caffeine, length dependence of Ca2+ sensitivity was observed, and the degree of potentiation after 10-Hz stimulation showed a linear decrease with increased length (DT = 1.47 - 0.05 ML, r2 = 0.95, where DT is developed tension). Length dependence of Ca2+ sensitivity was decreased by caffeine when caffeine was administered in amounts estimated to result in 0.5 and 0.75 mM concentrations. Furthermore, the negative slope of the relationship between staircase potentiation and muscle length was diminished at the lower caffeine dose, and the slope was not different from zero after the higher dose (DT = 1.53 - 0.009 ML, r2 = 0.43). Our study shows that length dependence of Ca2+ sensitivity in intact skeletal muscle is diminished by caffeine. Caffeine also suppressed the length dependence of staircase potentiation, suggesting that the mechanism of this length dependence may be closely related to the mechanism for length dependence of Ca2+ sensitivity.

Synthesis and antiviral activity of certain second generation methylenecyclopropane nucleosides

PubMed Central

Williams, John D.; Khan, Atiyya R.; Harden, Emma A.; Hartline, Caroll B.; Jefferson, Geraldine M.; Keith, Kathy A.; Prichard, Mark N.; Zemlicka, Jiri; Peet, Norton P.; Bowlin, Terry L.

2012-01-01

A second-generation series of substituted methylenecyclopropane nucleosides (MCPNs) has been synthesized and evaluated for antiviral activity against a panel of human herpesviruses, and for cytotoxicity. Although alkylated 2,6-diaminopurine analogs showed little antiviral activity, the compounds containing ether and thioether substituents at the 6-position of the purine did demonstrate potent and selective antiviral activity against several different human herpesviruses. In the 6-alkoxy series, antiviral activity depended on the length of the ether carbon chain, with the optimum chain length being about four carbon units long. For the corresponding thioethers, compounds containing secondary thioethers were more potent than those with primary thioethers. PMID:22607883

Effect of accelerated crucible rotation on melt composition in high-pressure vertical Bridgman growth of cadmium zinc telluride

NASA Astrophysics Data System (ADS)

Yeckel, Andrew; Derby, Jeffrey J.

2000-02-01

Three-dimensional axisymmetric, time-dependent simulations of the high-pressure vertical Bridgman growth of large-diameter cadmium zinc telluride are performed to study the effect of accelerated crucible rotation (ACRT) on crystal growth dynamics. The model includes details of heat transfer, melt convection, solid-liquid interface shape, and dilute zinc segregation. Application of ACRT greatly improves mixing in the melt, but causes an overall increased deflection of the solid-liquid interface. The flow exhibits a Taylor-Görtler instability at the crucible sidewall, which further enhances melt mixing. The rate of mixing depends strongly on the length of the ACRT cycle, with an optimum half-cycle length between 2 and 4 Ekman time units. Significant melting of the crystal occurs during a portion of the rotation cycle, caused by periodic reversal of the secondary flow at the solid-liquid interface, indicating the possibility of compositional striations.

Unit and internal chain profiles of maca amylopectin.

PubMed

Zhang, Ling; Li, Guantian; Yao, Weirong; Zhu, Fan

2018-03-01

Unit chain length distributions of amylopectin and its φ, β-limit dextrins, which reflect amylopectin internal structure from three maca starches, were determined by high-performance anion-exchange chromatography with pulsed amperometric detection after debranching, and the samples were compared with maize starch. The amylopectins exhibited average chain lengths ranging from 16.72 to 17.16, with ranges of total internal chain length, external chain length, and internal chain length of the maca amylopectins at 12.49 to 13.68, 11.24 to 11.89, and 4.27 to 4.48. The average chain length, external chain length, internal chain length, and total internal chain length were comparable in three maca amylopectins. Amylopectins of the three maca genotypes studied here presented no significant differences in their unit chain length profiles, but did show significant differences in their internal chain profiles. Additional genetic variations between different maca genotypes need to be studied to provide unit- and internal chain profiles of maca amylopectin. Copyright © 2017. Published by Elsevier Ltd.

Myosin filament activation in the heart is tuned to the mechanical task

PubMed Central

Reconditi, Massimo; Caremani, Marco; Pinzauti, Francesca; Powers, Joseph D.; Narayanan, Theyencheri; Stienen, Ger J. M.; Linari, Marco; Lombardi, Vincenzo

2017-01-01

The mammalian heart pumps blood through the vessels, maintaining the dynamic equilibrium in a circulatory system driven by two pumps in series. This vital function is based on the fine-tuning of cardiac performance by the Frank–Starling mechanism that relates the pressure exerted by the contracting ventricle (end systolic pressure) to its volume (end systolic volume). At the level of the sarcomere, the structural unit of the cardiac myocytes, the Frank–Starling mechanism consists of the increase in active force with the increase of sarcomere length (length-dependent activation). We combine sarcomere mechanics and micrometer–nanometer-scale X-ray diffraction from synchrotron light in intact ventricular trabeculae from the rat to measure the axial movement of the myosin motors during the diastole–systole cycle under sarcomere length control. We find that the number of myosin motors leaving the off, ATP hydrolysis-unavailable state characteristic of the diastole is adjusted to the sarcomere length-dependent systolic force. This mechanosensing-based regulation of the thick filament makes the energetic cost of the systole rapidly tuned to the mechanical task, revealing a prime aspect of the Frank–Starling mechanism. The regulation is putatively impaired by cardiomyopathy-causing mutations that affect the intramolecular and intermolecular interactions controlling the off state of the motors. PMID:28265101

The cellular level of O-antigen polymerase Wzy determines chain length regulation by WzzB and WzzpHS-2 in Shigella flexneri 2a.

PubMed

Carter, Javier A; Jiménez, Juan C; Zaldívar, Mercedes; Alvarez, Sergio A; Marolda, Cristina L; Valvano, Miguel A; Contreras, Inés

2009-10-01

The lipopolysaccharide O antigen of Shigella flexneri 2a has two preferred chain lengths, a short (S-OAg) composed of an average of 17 repeated units and a very long (VL-OAg) of about 90 repeated units. These chain length distributions are controlled by the chromosomally encoded WzzB and the plasmid-encoded Wzz(pHS-2) proteins, respectively. In this study, genes wzzB, wzz(pHS-2) and wzy (encoding the O-antigen polymerase) were cloned under the control of arabinose- and rhamnose-inducible promoters to investigate the effect of varying their relative expression levels on O antigen polysaccharide chain length distribution. Controlled expression of the chain length regulators wzzB and wzz(pHS-2) revealed a dose-dependent production of each modal length. Increase in one mode resulted in a parallel decrease in the other, indicating that chain length regulators compete to control the degree of O antigen polymerization. Also, when expression of the wzy gene is low, S-OAg but not VL-OAg is produced. Production of VL-OAg requires high induction levels of wzy. Thus, the level of expression of wzy is critical in determining O antigen modal distribution. Western blot analyses of membrane proteins showed comparable high levels of the WzzB and Wzz(pHS-2) proteins, but very low levels of Wzy. In vivo cross-linking experiments and immunoprecipitation of membrane proteins did not detect any direct interaction between Wzy and WzzB, suggesting the possibility that these two proteins may not interact physically but rather by other means such as via translocated O antigen precursors.

A pragmatic implementation of a 6-day physiotherapy service in a mixed inpatient rehabilitation unit.

PubMed

Caruana, Erin L; Kuys, Suzanne S; Clarke, Jane; Bauer, Sandra G

2017-08-01

This study determined the impact of a pragmatic 6-day physiotherapy service on length of stay, functional independence, gait and balance in people undergoing inpatient rehabilitation, compared to a 5-day service. A prospective cohort study with historical comparison was undertaken in a mixed inpatient rehabilitation unit. Intervention period participants (2011) meeting inclusion criteria were eligible for a 6-day physiotherapy service. All other participants, including the historical cohort (2010) received usual care (5-day physiotherapy). Length of stay, functional independence, gait and balance performance were measured. A total of 536 individuals participated in this study; 270 in 2011 (60% received 6-day physiotherapy) and 266 in 2010. Participants in 2011 showed a trend for reduced length of stay (1.7 days, 95%CI -0.53 to 3.92) compared to 2010. Other measures showed no significant differences between cohorts. In 2011, those receiving 6-day physiotherapy were more dependent, but showed significantly improved functional independence and balance compared to those receiving 5-day physiotherapy (p < 0.040) without impacting length of stay. Implementing a 6-day physiotherapy service in a "real-world" rehabilitation setting demonstrated a trend towards reduced length of stay, and improved functional gains. This service could lead to cost-savings for hospitals and improved patient flow. Implications for Rehabilitation "Real-world" implementation of a 6-day physiotherapy service in rehabilitation shows a trend for reducing length of stay. This reduction in length of stay may lead to cost-savings for the hospital system, and improve patient flow into rehabilitation. Patients receiving 6-day physiotherapy made significant gains in balance and functional independence compared to patients receiving 5-day physiotherapy services in the rehabilitation setting.

Depressed Frank-Starling mechanism in the left ventricular muscle of the knock-in mouse model of dilated cardiomyopathy with troponin T deletion mutation ΔK210.

PubMed

Inoue, Takahiro; Kobirumaki-Shimozawa, Fuyu; Kagemoto, Tatsuya; Fujii, Teruyuki; Terui, Takako; Kusakari, Yoichiro; Hongo, Kenichi; Morimoto, Sachio; Ohtsuki, Iwao; Hashimoto, Kazuhiro; Fukuda, Norio

2013-10-01

It has been reported that the Frank-Starling mechanism is coordinately regulated in cardiac muscle via thin filament "on-off" equilibrium and titin-based lattice spacing changes. In the present study, we tested the hypothesis that the deletion mutation ΔK210 in the cardiac troponin T gene shifts the equilibrium toward the "off" state and accordingly attenuate the sarcomere length (SL) dependence of active force production, via reduced cross-bridge formation. Confocal imaging in isolated hearts revealed that the cardiomyocytes were enlarged, especially in the longitudinal direction, in ΔK210 hearts, with striation patterns similar to those in wild type (WT) hearts, suggesting that the number of sarcomeres is increased in cardiomyocytes but the sarcomere length remains unaltered. For analysis of the SL dependence of active force, skinned muscle preparations were obtained from the left ventricle of WT and knock-in (ΔK210) mice. An increase in SL from 1.90 to 2.20μm shifted the mid-point (pCa50) of the force-pCa curve leftward by ~0.21pCa units in WT preparations. In ΔK210 muscles, Ca(2+) sensitivity was lower by ~0.37pCa units, and the SL-dependent shift of pCa50, i.e., ΔpCa50, was less pronounced (~0.11pCa units), with and without protein kinase A treatment. The rate of active force redevelopment was lower in ΔK210 preparations than in WT preparations, showing blunted thin filament cooperative activation. An increase in thin filament cooperative activation upon an increase in the fraction of strongly bound cross-bridges by MgADP increased ΔpCa50 to ~0.21pCa units. The depressed Frank-Starling mechanism in ΔK210 hearts is the result of a reduction in thin filament cooperative activation. © 2013.

Turbulent kinetic energy and a possible hierarchy of length scales in a generalization of the Navier-Stokes alpha theory.

PubMed

Fried, Eliot; Gurtin, Morton E

2007-05-01

We present a continuum-mechanical formulation and generalization of the Navier-Stokes alpha theory based on a general framework for fluid-dynamical theories with gradient dependencies. Our flow equation involves two additional problem-dependent length scales alpha and beta. The first of these scales enters the theory through the internal kinetic energy, per unit mass, alpha2|D|2, where D is the symmetric part of the gradient of the filtered velocity. The remaining scale is associated with a dissipative hyperstress which depends linearly on the gradient of the filtered vorticity. When alpha and beta are equal, our flow equation reduces to the Navier-Stokes alpha equation. In contrast to the original derivation of the Navier-Stokes alpha equation, which relies on Lagrangian averaging, our formulation delivers boundary conditions. For a confined flow, our boundary conditions involve an additional length scale l characteristic of the eddies found near walls. Based on a comparison with direct numerical simulations for fully developed turbulent flow in a rectangular channel of height 2h, we find that alphabeta approximately Re(0.470) and lh approximately Re(-0.772), where Re is the Reynolds number. The first result, which arises as a consequence of identifying the internal kinetic energy with the turbulent kinetic energy, indicates that the choice alpha=beta required to reduce our flow equation to the Navier-Stokes alpha equation is likely to be problematic. The second result evinces the classical scaling relation eta/L approximately Re(-3/4) for the ratio of the Kolmogorov microscale eta to the integral length scale L . The numerical data also suggests that l < or = beta . We are therefore led to conjecture a tentative hierarchy, l < or = beta < alpha , involving the three length scales entering our theory.

An evaluation of the impact of the ventilator care bundle.

PubMed

Crunden, Eddie; Boyce, Carolyn; Woodman, Helen; Bray, Barbara

2005-01-01

A number of interventions have been shown to improve the outcomes of patients who are invasively ventilated in intensive care units (ICUs). However, significant problems still exist in implementing research findings into clinical practice. The aim of this study was to assess whether the systematic and methodical implementation of evidence-based interventions encapsulated in a care bundle influenced length of ventilation and ICU length of stay (LOS). A ventilator care bundle was introduced within a general ICU and evaluated 1 year later. The care bundle was composed of four protocols that consisted of prophylaxis against peptic ulceration, prophylaxis against deep vein thrombosis, daily cessation of sedation and elevation of the patient's head and chest to at least 30 degrees to the horizontal. Compliance with the bundle was assessed, as was ICU LOS, ICU mortality and ICU/high-dependency unit patient throughput. Mean ICU LOS was reduced from 13-75 [standard deviation (SD) 19.11] days to 8.36 (SD 10.21) days (p<0.05). Mean ventilator days were reduced from 10.8 (SD 15.58) days to 6.1 (SD 8.88) days. Unit patient throughput increased by 30.1% and the number of invasively ventilated patients increased by 39.5%. Care bundles encourage the consistent and systematic application of evidence-based protocols used in particular treatment regimes. Since the introduction of the ventilator care bundle, length of ventilation and ICU LOS have reduced significantly.

Spatial confinement of active microtubule networks induces large-scale rotational cytoplasmic flow

PubMed Central

Suzuki, Kazuya; Miyazaki, Makito; Takagi, Jun; Itabashi, Takeshi; Ishiwata, Shin’ichi

2017-01-01

Collective behaviors of motile units through hydrodynamic interactions induce directed fluid flow on a larger length scale than individual units. In cells, active cytoskeletal systems composed of polar filaments and molecular motors drive fluid flow, a process known as cytoplasmic streaming. The motor-driven elongation of microtubule bundles generates turbulent-like flow in purified systems; however, it remains unclear whether and how microtubule bundles induce large-scale directed flow like the cytoplasmic streaming observed in cells. Here, we adopted Xenopus egg extracts as a model system of the cytoplasm and found that microtubule bundle elongation induces directed flow for which the length scale and timescale depend on the existence of geometrical constraints. At the lower activity of dynein, kinesins bundle and slide microtubules, organizing extensile microtubule bundles. In bulk extracts, the extensile bundles connected with each other and formed a random network, and vortex flows with a length scale comparable to the bundle length continually emerged and persisted for 1 min at multiple places. When the extracts were encapsulated in droplets, the extensile bundles pushed the droplet boundary. This pushing force initiated symmetry breaking of the randomly oriented bundle network, leading to bundles aligning into a rotating vortex structure. This vortex induced rotational cytoplasmic flows on the length scale and timescale that were 10- to 100-fold longer than the vortex flows emerging in bulk extracts. Our results suggest that microtubule systems use not only hydrodynamic interactions but also mechanical interactions to induce large-scale temporally stable cytoplasmic flow. PMID:28265076

Neuromuscular organization of avian flight muscle: architecture of single muscle fibres in muscle units of the pectoralis (pars thoracicus) of pigeon (Columba livia)

PubMed Central

Sokoloff, A. J.

1999-01-01

The M. pectoralis (pars thoracicus) of pigeons (Columba livia) is comprised of short muscle fibres that do not extend from muscle origin to insertion but overlap 'in-series'. Individual pectoralis motor units are limited in territory to a portion of muscle length and are comprised of either fast twitch, oxidative and glycolytic fibres (FOG) or fast twitch and glycolytic fibres (FG). FOG fibres make up 88 to 90% of the total muscle population and have a mean diameter one-half of that of the relatively large FG fibres. Here we report on the organization of individual fibres identified in six muscle units depleted of glycogen, three comprised of FOG fibres and three comprised of FG fibres. For each motor unit, fibre counts revealed unequal numbers of depleted fibres in different unit cross-sections. We traced individual fibres in one unit comprised of FOG fibres and a second comprised of FG fibres. Six fibres from a FOG unit (total length 15.45 mm) ranged from 10.11 to 11.82 mm in length and averaged (± s.d.) 10.74 ± 0.79 mm. All originated bluntly (en mass) from a fascicle near the proximal end of the muscle unit and all terminated intramuscularly. Five of these ended in a taper and one ended bluntly. Fibres coursed on average for 70% of the muscle unit length. Six fibres from a FG unit (total length 34.76 mm) ranged from 8.97 to 18.38 mm in length and averaged 15.32 ± 3.75 mm. All originated bluntly and terminated intramuscularly; one of these ended in a taper and five ended bluntly. Fibres coursed on average for 44% of the muscle unit length. Because fibres of individual muscle units do not extend the whole muscle unit territory, the effective cross-sectional area changes along the motor unit length. These non-uniformities in the distribution of fibres within a muscle unit emphasize that the functional interactions within and between motor units are complex.

Hydrodynamic Force on a Cylinder Oscillating at Low Frequency

NASA Technical Reports Server (NTRS)

Berg, Robert F.; Yao, Minwu; Panzarella, Charles H.

2007-01-01

The hydrodynamic force on a cylinder oscillating transversely to its axis is a nonlinear function of the displacement amplitude x0. We report measurements and numerical calculations of the force at frequencies low enough that delta > R, where delta is the viscous penetration length and R is the cylinder radius. For small amplitudes, the numerically calculated Fourier transform of the force per unit length, F(sub small), agrees with Stokes' analytical calculation. For larger amplitudes, the force per unit length found by both calculation and measurement is F = F(sub small)C (x(sub 0)/delta,R/delta). The complex function C depends only weakly on R/delta, indicating that x0/delta is more appropriate as a scaling variable than the Keulegan-Carpenter number KC = pi*x(sub 0)/R. The measurements used a torsion oscillator driven at frequencies from 1 to 12 Hz while immersed in dense xenon. The oscillator comprised cylinders with an effective radius of R = 13.4 micron and oscillation amplitudes as large as x(sub 0)/delta = 4 (corresponding to KC as large as 71). The calculations used similar conditions except that the amplitudes were as large as x0/delta = 28.

Effect of arch length on the functional well-being of dentate adults.

PubMed

Montero, J; Bravo, M; Hernández, L A; Dib, A

2009-05-01

The aim of this study was to assess the influence of arch length and the number of occlusal units on the oral functions and general satisfaction perceived by dentate adults without dentures who had all their aesthetic units intact. We performed an epidemiological study at randomly chosen health centres on populations of adults without dentures. The subjects (n = 624) were classified as complete dental arch (CDA), interrupted dental arch (IDA) or shortened dental arches (SDA), depending on the length and continuity of the dental arches. We gathered clinical data and data on functional ability and oral satisfaction, plotting them on a scale of 0-10. The individuals with a shortened dental arch were found to have longer-lasting, more frequent and more severe functional limitations upon chewing, smiling and speaking than those with a complete or interrupted arch. The prevalance rate ratio (95% CI) of functional limitations in the SDA group was higher than in the aggregated CDA-IDA group, the values ranging between 1.56 (1.22-12.01) as regards chewing and 2.35 (1.45-3.85) in the case of smiling. However, in general all groups were satisfied with their oral status.

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

Assenberg, René; Delmas, Olivier; Graham, Stephen C.

The expression, purification and crystallization of the full-length matrix protein from three lyssaviruses is described. The matrix (M) proteins of lyssaviruses (family Rhabdoviridae) are crucial to viral morphogenesis as well as in modulating replication and transcription of the viral genome. To date, no high-resolution structural information has been obtained for full-length rhabdovirus M. Here, the cloning, expression and purification of the matrix proteins from three lyssaviruses, Lagos bat virus (LAG), Mokola virus and Thailand dog virus, are described. Crystals have been obtained for the full-length M protein from Lagos bat virus (LAG M). Successful crystallization depended on a number ofmore » factors, in particular the addition of an N-terminal SUMO fusion tag to increase protein solubility. Diffraction data have been recorded from crystals of native and selenomethionine-labelled LAG M to 2.75 and 3.0 Å resolution, respectively. Preliminary analysis indicates that these crystals belong to space group P6{sub 1}22 or P6{sub 5}22, with unit-cell parameters a = b = 56.9–57.2, c = 187.9–188.6 Å, consistent with the presence of one molecule per asymmetric unit, and structure determination is currently in progress.« less

Optimal pricing and lot-sizing for perishable inventory with price and time dependent ramp-type demand

NASA Astrophysics Data System (ADS)

Panda, S.; Saha, S.; Basu, M.

2013-01-01

Product perishability is an important aspect of inventory control. To minimise the effect of deterioration, retailers in supermarkets, departmental store managers, etc. always want higher inventory depletion rate. In this article, we propose a dynamic pre- and post-deterioration cumulative discount policy to enhance inventory depletion rate resulting low volume of deterioration cost, holding cost and hence higher profit. It is assumed that demand is a price and time dependent ramp-type function and the product starts to deteriorate after certain amount of time. Unlike the conventional inventory models with pricing strategies, which are restricted to a fixed number of price changes and to a fixed cycle length, we allow the number of price changes before as well as after the start of deterioration and the replenishment cycle length to be the decision variables. Before start of deterioration, discounts on unit selling price are provided cumulatively in successive pricing cycles. After the start of deterioration, discounts on reduced unit selling price are also provided in a cumulative way. A mathematical model is developed and the existence of the optimal solution is verified. A numerical example is presented, which indicates that under the cumulative effect of price discounting, dynamic pricing policy outperforms static pricing strategy. Sensitivity analysis of the model is carried out.

Length dependence of staircase potentiation: interactions with caffeine and dantrolene sodium.

PubMed

Rassier, D E; MacIntosh, B R

2000-04-01

In skeletal muscle, there is a length dependence of staircase potentiation for which the mechanism is unclear. In this study we tested the hypothesis that abolition of this length dependence by caffeine is effected by a mechanism independent of enhanced Ca2+ release. To test this hypothesis we have used caffeine, which abolishes length dependence of potentiation, and dantrolene sodium, which inhibits Ca2+ release. In situ isometric twitch contractions of rat gastrocnemius muscle before and after 20 s of repetitive stimulation at 5 Hz were analyzed at optimal length (Lo), Lo - 10%, and Lo + 10%. Potentiation was observed to be length dependent, with an increase in developed tension (DT) of 78 +/- 12, 51 +/- 5, and 34 +/- 9% (mean +/- SEM), at Lo - 10%, Lo, and Lo + 10%, respectively. Caffeine diminished the length dependence of activation and suppressed the length dependence of staircase potentiation, giving increases in DT of 65+/-13, 53 +/- 11, and 45 +/- 12% for Lo - 10%, Lo, and Lo + 10%, respectively. Dantrolene administered after caffeine did not reverse this effect. Dantrolene alone depressed the potentiation response, but did not affect the length dependence of staircase potentiation, with increases in DT of 58 +/- 17, 26 +/- 8, and 18 +/- 7%, respectively. This study confirms that there is a length dependence of staircase potentiation in mammalian skeletal muscle which is suppressed by caffeine. Since dantrolene did not alter this suppression of the length dependence of potentiation by caffeine, it is apparently not directly modulated by Ca2+ availability in the myoplasm.

Risk stratification for malignant progression in Barrett's esophagus: Gender, age, duration and year of surveillance.

PubMed

Gatenby, Piers; Bhattacharjee, Santanu; Wall, Christine; Caygill, Christine; Watson, Anthony

2016-12-28

To clarify risk based upon segment length, diagnostic histological findings, patient age and year of surveillance, duration of surveillance and gender. Patients registered with the United Kingdom Barrett's Oesophagus Registry from 9 United Kingdom centers were included. The outcome measures were (1) development of all grades of dysplasia; (2) development of high-grade of dysplasia or adenocarcinoma; and (3) development of adenocarcinoma. Prevalent cases and subjects with < 1 year of follow-up were excluded. The covariates examined were segment length, previous biopsy findings, age at surveillance, duration of surveillance, year of surveillance and gender. One thousand and one hundred thirty six patients were included (total 6474 patient-years). Fifty-four patients developed adenocarcinoma (0.83% per annum), 70 developed high-grade dysplasia/adenocarcinoma (1.1% per annum) and 190 developed any grade of dysplasia (3.5% per annum). High grade dysplasia and adenocarcinoma increased with age and duration of surveillance. The risk of low-grade dysplasia development was not dependent on age at surveillance. Segment length and previous biopsy findings were also significant factors for development of dysplasia and adenocarcinoma. The risk of development of low-grade dysplasia is independent of age at surveillance, but high-grade dysplasia and adenocarcinoma were more commonly found at older age. Segment length and previous biopsy findings are also markers of risk. This study did not demonstrate stabilisation of the metaplastic segment with prolonged surveillance.

[Effectiveness of special stroke units in treatment of acute stroke].

PubMed

Nikolaus, T; Jamour, M

2000-04-01

In Germany the implementation of specialized wards for the care of stroke patients is proposed. However, which type of organized inpatient stroke unit care is most effective and which group of patients will benefit most remains unclear. Based on the analyses of the Stroke Unit Trialists' Collaboration this paper reports results of randomized and quasi-randomized trials that compared organized inpatient (stroke unit) care with contemporary conventional care. The primary analyses examined death, dependency and institutionalization. Secondary outcome measures included patient quality of life, patient and carer satisfaction and length of stay in hospital and/or institution. The analysis of twenty trails with 3864 patients showed a reduction in the rate of deaths in the stroke unit group as compared with the control group (OR 0.83, 95% CI 0.71-0.97). The odds of death or institutionalized care were lower (OR 0.76, 95% CI 0.65-0.90) as were death or dependency (OR 0.75, 95% CI 0.65-0.87). The results were independent of patient age, sex, stroke severity, and type of stroke unit organization. Organized care in stroke units resulted in benefits for stroke patients with regard to survival, independence, and probability of living at home. However, these results refer exclusively to Anglo-American and Scandinavian trials. German stroke unit services are organized in a different way. No data about the effectiveness of the German model is yet available.

Do critical care units play a role in the management of gynaecological oncology patients? The contribution of gynaecologic oncologist in running critical care units.

PubMed

Davidovic-Grigoraki, Miona; Thomakos, Nikolaos; Haidopoulos, Dimitrios; Vlahos, Giorgos; Rodolakis, Alexandros

2017-03-01

Routine post-operative care in high dependency unit (HDU), surgical intensive care unit (SICU) and intensive care unit (ICU) after high-risk gynaecological oncology surgical procedures may allow for greater recognition and correct management of post-operative complications, thereby reducing long-term morbidity and mortality. On the other hand, unnecessary admissions to these units lead to increased morbidity - nosocomial infections, increased length of hospital stay and higher hospital costs. Gynaecological oncology surgeons continue to look after their patient in the HDU/SICU and have the final role in decision-making on day-to-day basis, making it important to be well versed in critical care management and ensure the best care for their patients. Post-operative monitoring and the presence of comorbid illnesses are the most common reasons for admission to the HDU/SICU. Elderly and malnutritioned patients, as well as, bowel resection, blood loss or greater fluid resuscitation during the surgery have prolonged HDU/SICU stay. Patients with ovarian cancer have a worse survival outcome than the patients with other types of gynaecological cancer. Dependency care is a part of surgical management and it should be incorporated formally into gynaecologic oncology training programme. © 2016 John Wiley & Sons Ltd.

Average focal length and power of a section of any defined surface.

PubMed

Kaye, Stephen B

2010-04-01

To provide a method to allow calculation of the average focal length and power of a lens through a specified meridian of any defined surface, not limited to the paraxial approximations. University of Liverpool, Liverpool, United Kingdom. Functions were derived to model back-vertex focal length and representative power through a meridian containing any defined surface. Average back-vertex focal length was based on the definition of the average of a function, using the angle of incidence as an independent variable. Univariate functions allowed determination of average focal length and power through a section of any defined or topographically measured surface of a known refractive index. These functions incorporated aberrations confined to the section. The proposed method closely approximates the average focal length, and by inference power, of a section (meridian) of a surface to a single or scalar value. It is not dependent on the paraxial and other nonconstant approximations and includes aberrations confined to that meridian. A generalization of this method to include all orthogonal and oblique meridians is needed before a comparison with measured wavefront values can be made. Copyright (c) 2010 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Silicon nitride directional coupler interferometer for surface sensing

NASA Astrophysics Data System (ADS)

Okubo, Kyohei; Uchiyamada, Ken; Asakawa, Kiyoshi; Suzuki, Hiroaki

2017-01-01

A silicon nitride directional coupler (DC) used to create a biosensing device is presented. The DC detects changes in the refractive index of the cladding (nclad) as changes in the relative output intensity. The DC length (L), nclad-dependent sensitivities of the DC, and preferred dimensions of the single-mode DC waveguides are obtained through numerical simulations. The performance of the DC is evaluated through end-fire coupling measurements. The intensities measured after varying the nclad using air, water, and glycerol solutions agree well with the fitting for a wide range of L values between 60 and 600 μm, i.e., corresponding to 6 to 60 times the coupling length. The bulk refractive index sensitivity was investigated using glycerol solutions of different concentrations and was found to be 18.9 optical intensity units per refractive index unit (OIU/RIU). Biotin/streptavidin bindings were detected with a sensitivity of 60 OIU/RIU and a detection limit of 0.13 μM, suggesting the feasibility of the DC for immunosensing.

Analysis and selection of magnitude relations for the Working Group on Utah Earthquake Probabilities

USGS Publications Warehouse

Duross, Christopher; Olig, Susan; Schwartz, David

2015-01-01

Prior to calculating time-independent and -dependent earthquake probabilities for faults in the Wasatch Front region, the Working Group on Utah Earthquake Probabilities (WGUEP) updated a seismic-source model for the region (Wong and others, 2014) and evaluated 19 historical regressions on earthquake magnitude (M). These regressions relate M to fault parameters for historical surface-faulting earthquakes, including linear fault length (e.g., surface-rupture length [SRL] or segment length), average displacement, maximum displacement, rupture area, seismic moment (Mo ), and slip rate. These regressions show that significant epistemic uncertainties complicate the determination of characteristic magnitude for fault sources in the Basin and Range Province (BRP). For example, we found that M estimates (as a function of SRL) span about 0.3–0.4 units (figure 1) owing to differences in the fault parameter used; age, quality, and size of historical earthquake databases; and fault type and region considered.

Self-imposed length limits in recreational fisheries

USGS Publications Warehouse

Chizinski, Christopher J.; Martin, Dustin R.; Hurley, Keith L.; Pope, Kevin L.

2014-01-01

A primary motivating factor on the decision to harvest a fish among consumptive-orientated anglers is the size of the fish. There is likely a cost-benefit trade-off for harvest of individual fish that is size and species dependent, which should produce a logistic-type response of fish fate (release or harvest) as a function of fish size and species. We define the self-imposed length limit as the length at which a captured fish had a 50% probability of being harvested, which was selected because it marks the length of the fish where the probability of harvest becomes greater than the probability of release. We assessed the influences of fish size, catch per unit effort, size distribution of caught fish, and creel limit on the self-imposed length limits for bluegill Lepomis macrochirus, channel catfish Ictalurus punctatus, black crappie Pomoxis nigromaculatus and white crappie Pomoxis annularis combined, white bass Morone chrysops, and yellow perch Perca flavescens at six lakes in Nebraska, USA. As we predicted, the probability of harvest increased with increasing size for all species harvested, which supported the concept of a size-dependent trade-off in costs and benefits of harvesting individual fish. It was also clear that probability of harvest was not simply defined by fish length, but rather was likely influenced to various degrees by interactions between species, catch rate, size distribution, creel-limit regulation and fish size. A greater understanding of harvest decisions within the context of perceived likelihood that a creel limit will be realized by a given angler party, which is a function of fish availability, harvest regulation and angler skill and orientation, is needed to predict the influence that anglers have on fish communities and to allow managers to sustainable manage exploited fish populations in recreational fisheries.

Leucocytes DNA damage in mice exposed to JS-118 by the comet assay.

PubMed

Zhang, Tao; Hu, Jiye; Zhang, Yuchao; Zhao, Qianfei; Ning, Jun

2011-09-01

JS-118 is an extensively used insecticide in China. The present study investigated the genotoxic effect of JS-118 on whole blood at 24, 48, 72 and 96 h by using alkaline comet assay. Male Kunming mice were given 6.25, 12.5, 25, 50 and 100 mg/kg BW of JS-118 intraperitoneally. A statistically significant increase in all comet parameters indicating DNA damage was observed at 24 h post-treatment (p < 0.05). A clear concentration-dependent increase of DNA damage was revealed as evident by the OTM (arbitrary units), tail length (µm) and tail DNA (%). From 48 h post-treatment, a gradual decrease in mean comet parameters was noted. By 96 h of post-treatment, the mean comet tail length reached control levels indicating repair of damaged DNA. This study on mice showed different DNA damage depending on the concentration of JS-118 and the period of treatment. The present study provided further information of the potential risk of the genetic damage caused by JS-118.

Time-dependent probability density functions and information geometry in stochastic logistic and Gompertz models

NASA Astrophysics Data System (ADS)

Tenkès, Lucille-Marie; Hollerbach, Rainer; Kim, Eun-jin

2017-12-01

A probabilistic description is essential for understanding growth processes in non-stationary states. In this paper, we compute time-dependent probability density functions (PDFs) in order to investigate stochastic logistic and Gompertz models, which are two of the most popular growth models. We consider different types of short-correlated multiplicative and additive noise sources and compare the time-dependent PDFs in the two models, elucidating the effects of the additive and multiplicative noises on the form of PDFs. We demonstrate an interesting transition from a unimodal to a bimodal PDF as the multiplicative noise increases for a fixed value of the additive noise. A much weaker (leaky) attractor in the Gompertz model leads to a significant (singular) growth of the population of a very small size. We point out the limitation of using stationary PDFs, mean value and variance in understanding statistical properties of the growth in non-stationary states, highlighting the importance of time-dependent PDFs. We further compare these two models from the perspective of information change that occurs during the growth process. Specifically, we define an infinitesimal distance at any time by comparing two PDFs at times infinitesimally apart and sum these distances in time. The total distance along the trajectory quantifies the total number of different states that the system undergoes in time, and is called the information length. We show that the time-evolution of the two models become more similar when measured in units of the information length and point out the merit of using the information length in unifying and understanding the dynamic evolution of different growth processes.

Chain conformations dictate multiscale charge transport phenomena in disordered semiconducting polymers

PubMed Central

Noriega, Rodrigo; Salleo, Alberto; Spakowitz, Andrew J.

2013-01-01

Existing models for the electronic properties of conjugated polymers do not capture the spatial arrangement of the disordered macromolecular chains over which charge transport occurs. Here, we present an analytical and computational description in which the morphology of individual polymer chains is dictated by well-known statistical models and the electronic coupling between units is determined using Marcus theory. The multiscale transport of charges in these materials (high mobility at short length scales, low mobility at long length scales) is naturally described with our framework. Additionally, the dependence of mobility with electric field and temperature is explained in terms of conformational variability and spatial correlation. Our model offers a predictive approach to connecting processing conditions with transport behavior. PMID:24062459

Chain conformations dictate multiscale charge transport phenomena in disordered semiconducting polymers.

PubMed

Noriega, Rodrigo; Salleo, Alberto; Spakowitz, Andrew J

2013-10-08

Existing models for the electronic properties of conjugated polymers do not capture the spatial arrangement of the disordered macromolecular chains over which charge transport occurs. Here, we present an analytical and computational description in which the morphology of individual polymer chains is dictated by well-known statistical models and the electronic coupling between units is determined using Marcus theory. The multiscale transport of charges in these materials (high mobility at short length scales, low mobility at long length scales) is naturally described with our framework. Additionally, the dependence of mobility with electric field and temperature is explained in terms of conformational variability and spatial correlation. Our model offers a predictive approach to connecting processing conditions with transport behavior.

Risk stratification for malignant progression in Barrett’s esophagus: Gender, age, duration and year of surveillance

PubMed Central

Gatenby, Piers; Bhattacharjee, Santanu; Wall, Christine; Caygill, Christine; Watson, Anthony

2016-01-01

AIM To clarify risk based upon segment length, diagnostic histological findings, patient age and year of surveillance, duration of surveillance and gender. METHODS Patients registered with the United Kingdom Barrett’s Oesophagus Registry from 9 United Kingdom centers were included. The outcome measures were (1) development of all grades of dysplasia; (2) development of high-grade of dysplasia or adenocarcinoma; and (3) development of adenocarcinoma. Prevalent cases and subjects with < 1 year of follow-up were excluded. The covariates examined were segment length, previous biopsy findings, age at surveillance, duration of surveillance, year of surveillance and gender. RESULTS One thousand and one hundred thirty six patients were included (total 6474 patient-years). Fifty-four patients developed adenocarcinoma (0.83% per annum), 70 developed high-grade dysplasia/adenocarcinoma (1.1% per annum) and 190 developed any grade of dysplasia (3.5% per annum). High grade dysplasia and adenocarcinoma increased with age and duration of surveillance. The risk of low-grade dysplasia development was not dependent on age at surveillance. Segment length and previous biopsy findings were also significant factors for development of dysplasia and adenocarcinoma. CONCLUSION The risk of development of low-grade dysplasia is independent of age at surveillance, but high-grade dysplasia and adenocarcinoma were more commonly found at older age. Segment length and previous biopsy findings are also markers of risk. This study did not demonstrate stabilisation of the metaplastic segment with prolonged surveillance. PMID:28082811

Refractive Index Sensing with D-Shaped Plastic Optical Fibers for Chemical and Biochemical Applications

PubMed Central

Sequeira, Filipa; Duarte, Daniel; Bilro, Lúcia; Rudnitskaya, Alisa; Pesavento, Maria; Zeni, Luigi; Cennamo, Nunzio

2016-01-01

We report the optimization of the length of a D-shaped plastic optical fiber (POF) sensor for refractive index (RI) sensing from a numerical and experimental point of view. The sensing principle is based on total internal reflection (TIR). POFs with 1 mm in diameter were embedded in grooves, realized in planar supports with different lengths, and polished to remove the cladding and part of the core. All D-shaped POF sensors were tested using aqueous medium with different refractive indices (from 1.332 to 1.471) through intensity-based configuration. Results showed two different responses. Considering the refractive index (RI) range (1.33–1.39), the sensitivity and the resolution of the sensor were strongly dependent on the sensing region length. The highest sensitivity (resolution of 6.48 × 10−3 refractive index units, RIU) was obtained with 6 cm sensing length. In the RI range (1.41–1.47), the length of the sensing region was not a critical aspect to obtain the best resolution. These results enable the application of this optical platform for chemical and biochemical evanescent field sensing. The sensor production procedure is very simple, fast, and low-cost. PMID:27983608

Refractive Index Sensing with D-Shaped Plastic Optical Fibers for Chemical and Biochemical Applications.

PubMed

Sequeira, Filipa; Duarte, Daniel; Bilro, Lúcia; Rudnitskaya, Alisa; Pesavento, Maria; Zeni, Luigi; Cennamo, Nunzio

2016-12-13

We report the optimization of the length of a D-shaped plastic optical fiber (POF) sensor for refractive index (RI) sensing from a numerical and experimental point of view. The sensing principle is based on total internal reflection (TIR). POFs with 1 mm in diameter were embedded in grooves, realized in planar supports with different lengths, and polished to remove the cladding and part of the core. All D-shaped POF sensors were tested using aqueous medium with different refractive indices (from 1.332 to 1.471) through intensity-based configuration. Results showed two different responses. Considering the refractive index (RI) range (1.33-1.39), the sensitivity and the resolution of the sensor were strongly dependent on the sensing region length. The highest sensitivity (resolution of 6.48 × 10 -3 refractive index units, RIU) was obtained with 6 cm sensing length. In the RI range (1.41-1.47), the length of the sensing region was not a critical aspect to obtain the best resolution. These results enable the application of this optical platform for chemical and biochemical evanescent field sensing. The sensor production procedure is very simple, fast, and low-cost.

Self-organization of polymerizable bolaamphiphiles bearing diacetylene mesogenic group.

PubMed

Yin, Shouchun; Song, Bo; Liu, Guanqing; Wang, Zhiqiang; Zhang, Xi

2007-05-22

We report herein the synthesis of a series of polymerizable bolaamphiphiles containing a diacetylene group and mesogenic unit and their self-organization behaviors in bulk and at interface. The polymerizable bolaamphiphiles are noted as DPDA-n, where n refers to the spacer length of alkyl chain. DPDA-10 with suitable spacer length can self-organize into stable cylindrical micellar nanostructures, and these nanostructures have preferred orientation regionally when adsorbed at the mica/water interface. It is confirmed that the micellar nanostructure of DPDA-10 can be polymerized both in the bulk solution and in the film by UV irradiation. The emission property of DPDA-10 after UV irradiation has been significantly enhanced in comparison to that before polymerization, which may be due to the extension of the conjugated system arising from the transformation of the diacetylene group into polydiacetylene upon polymerization. In addition, the self-organization of DPDA-n is dependent on the spacer length. DPDA-7 with a short spacer length forms an irregular flat sheet structure with many defects; DPDA-15 with a long spacer length forms rodlike micellar structures. Thus, this work may provide a new approach for designing and fabricating organic functional nanostructured materials.

Laboratory on Legs: An Architecture for Adjustable Morphology with Legged Robots

DTIC Science & Technology

2012-04-01

fit within the body of the robot. Additional capabilities will largely depend upon a given activity, and should be easily reconfigurable to maximize...mobile robots, the essential units of actuation, computation, and sensing must be designed to fit within the body of the robot. Additional...PackBot,36 among others. Two parallel rails, 40 cm long and spaced at a center-to-center distance of 14 cm, span the length of the each robot’s body

The Sensetivity of Flood Frequency Analysis on Record Length in Continuous United States

NASA Astrophysics Data System (ADS)

Hu, L.; Nikolopoulos, E. I.; Anagnostou, E. N.

2017-12-01

In flood frequency analysis (FFA), sufficiently long data series are important to get more reliable results. Compared to return periods of interest, at-site FFA usually needs large data sets. Generally, the precision of at site estimators and time-sampling errors are associated with the length of a gauged record. In this work, we quantify the difference with various record lengths. we use generalized extreme value (GEV) and Log Pearson type III (LP3), two traditional methods on annual maximum stream flows to undertake FFA, and propose quantitative ways, relative difference in median and interquartile range (IQR) to compare the flood frequency performances on different record length from selected 350 USGS gauges, which have more than 70 years record length in Continuous United States. Also, we group those gauges into different regions separately based on hydrological unit map and discuss the geometry impacts. The results indicate that long record length can avoid imposing an upper limit on the degree of sophistication. Working with relatively longer record length may lead accurate results than working with shorter record length. Furthermore, the influence of hydrologic unites for the watershed boundary dataset on those gauges also be presented. The California region is the most sensitive to record length, while gauges in the east perform steady.

Scale and time dependence of serial correlations in word-length time series of written texts

NASA Astrophysics Data System (ADS)

Rodriguez, E.; Aguilar-Cornejo, M.; Femat, R.; Alvarez-Ramirez, J.

2014-11-01

This work considered the quantitative analysis of large written texts. To this end, the text was converted into a time series by taking the sequence of word lengths. The detrended fluctuation analysis (DFA) was used for characterizing long-range serial correlations of the time series. To this end, the DFA was implemented within a rolling window framework for estimating the variations of correlations, quantified in terms of the scaling exponent, strength along the text. Also, a filtering derivative was used to compute the dependence of the scaling exponent relative to the scale. The analysis was applied to three famous English-written literary narrations; namely, Alice in Wonderland (by Lewis Carrol), Dracula (by Bram Stoker) and Sense and Sensibility (by Jane Austen). The results showed that high correlations appear for scales of about 50-200 words, suggesting that at these scales the text contains the stronger coherence. The scaling exponent was not constant along the text, showing important variations with apparent cyclical behavior. An interesting coincidence between the scaling exponent variations and changes in narrative units (e.g., chapters) was found. This suggests that the scaling exponent obtained from the DFA is able to detect changes in narration structure as expressed by the usage of words of different lengths.

Isometric contractions of motor units in a fast twitch muscle of the cat

PubMed Central

Bagust, J.; Knott, Sarah; Lewis, D. M.; Luck, J. C.; Westerman, R. A.

1973-01-01

1. Isosmetric contractions of cat flexor digitorum longus whole muscles and of functionally isolated motor units have been measured under conditions similar to those used by Buller & Lewis (1965a). 2. Motor unit twitch time to peak was inversely related to axonal conduction velocity. The logarithm of tetanic tension was directly related to conduction velocity. These relationships suggest that each motoneurone has an influence on the muscle fibres which it innervates. 3. The ratio of twitch to tetanic tension was directly related to the time to peak of the motor unit. This fact might be explained by variation between motor units of the duration of `active state'. 4. The muscle length at which tension was maximal varied between motor units and the optima were found over the range of muscle lengths which could occur in the body. Slow motor units had longer optimal lengths. 5. The sample of motor units was considered to be unbiased because the distribution of axon conduction velocities was compatible with reported motor fibre diameter spectra of the muscle nerve. The mean motor unit tetanic tension gave a reasonable estimate of the number of α-motor axons in the muscle nerve. Twitch tensions gave a value that was 40% higher. 6. Motor unit and whole muscle data were in good agreement for length-tetanus tension curves, for times to peak and for twitch-tetanus ratios at long muscle lengths. PMID:4715372

Plot-scale effects on runoff and erosion along a slope degradation gradient

NASA Astrophysics Data System (ADS)

Moreno-de Las Heras, Mariano; Nicolau, José M.; Merino-MartíN, Luis; Wilcox, Bradford P.

2010-04-01

In Earth and ecological sciences, an important, crosscutting issue is the relationship between scale and the processes of runoff and erosion. In drylands, understanding this relationship is critical for understanding ecosystem functionality and degradation processes. Recent work has suggested that the effects of scale may differ depending on the extent of degradation. To test this hypothesis, runoff and sediment yield were monitored during a hydrological year on 20 plots of various lengths (1-15 m). These plots were located on a series of five reclaimed mining slopes in a Mediterranean-dry environment. The five slopes exhibited various degrees of vegetative cover and surface erosion. A general decrease of unit area runoff was observed with increasing plot scale for all slopes. Nevertheless, the amount of reinfiltrated runoff along each slope varied with the extent of degradation, being highest at the least degraded slope and vice versa. In other words, unit area runoff decreased the least on the most disturbed site as plot length increased. Unit area sediment yield declined with increasing plot length for the undisturbed and moderately disturbed sites, but it actually increased for the highly disturbed sites. The different scaling behavior of the most degraded slopes was especially clear under high-intensity rainfall conditions, when flow concentration favored rill erosion. Our results confirm that in drylands, the effects of scale on runoff and erosion change with the extent of degradation, resulting in a substantial loss of soil and water from disturbed systems, which could reinforce the degradation process through feedback mechanisms with vegetation.

Expression, purification and crystallization of a lyssavirus matrix (M) protein

PubMed Central

Assenberg, René; Delmas, Olivier; Graham, Stephen C.; Verma, Anil; Berrow, Nick; Stuart, David I.; Owens, Raymond J.; Bourhy, Hervé; Grimes, Jonathan M.

2008-01-01

The matrix (M) proteins of lyssaviruses (family Rhabdoviridae) are crucial to viral morphogenesis as well as in modulating replication and transcription of the viral genome. To date, no high-resolution structural information has been obtained for full-length rhabdovirus M. Here, the cloning, expression and purification of the matrix proteins from three lyssaviruses, Lagos bat virus (LAG), Mokola virus and Thailand dog virus, are described. Crystals have been obtained for the full-length M protein from Lagos bat virus (LAG M). Successful crystallization depended on a number of factors, in particular the addition of an N-terminal SUMO fusion tag to increase protein solubility. Diffraction data have been recorded from crystals of native and selenomethionine-labelled LAG M to 2.75 and 3.0 Å resolution, respectively. Preliminary analysis indicates that these crystals belong to space group P6122 or P6522, with unit-cell parameters a = b = 56.9–57.2, c = 187.9–188.6 Å, consistent with the presence of one molecule per asymmetric unit, and structure determination is currently in progress. PMID:18391421

Predictors of retention in a drug-free unit/substance abuse treatment in prison.

PubMed

Casares-López, María José; González-Menéndez, Ana; Festinger, David S; Fernández-García, Paula; Fernández-Hermida, José Ramón; Secades, Roberto; Matejkowski, Jason

2013-01-01

The high rate of dropout from treatment programs is a recurring problem in the field of drug dependence. The purpose of this study was to identify the predictors of retention in a prison-based drug-free unit (DFU). The relationships among subscales of the Addiction Severity Index (ASI) as well as motivation and personality profiles and length of stay in a DFU, of 57 prisoners admitted for the first time to the program were analyzed. The mean dropout rates were 52.9% at six months and 67.8% at one year. The mean length of stay was 195.05 days. Predictors of retention at six months included the ASI Family Composite Score, the motivation subscale Taking Steps, and Narcissistic personality trait score. Predictors of retention at one year included lower ASI Psychological Composite Score, higher scores on the motivation subscale Ambivalence, and higher number of charges pending at the time of admission to the program. Identification of these predictor variables may be useful for developing strategies to increase retention in the context of in-prison substance abuse treatment. Copyright © 2013. Published by Elsevier Ltd.

Carbachol dimers as homobivalent modulators of muscarinic receptors.

PubMed

Matucci, Rosanna; Nesi, Marta; Martino, Maria Vittoria; Bellucci, Cristina; Manetti, Dina; Ciuti, Elisa; Mazzolari, Angelica; Dei, Silvia; Guandalini, Luca; Teodori, Elisabetta; Vistoli, Giulio; Romanelli, Maria Novella

2016-05-15

A series of homodimers of the well-known cholinergic agonist carbachol have been synthesized, showing the two agonist units symmetrically connected through a methylene chain of variable length. The new compounds have been tested on the five cloned muscarinic receptors (hM1-5) expressed in CHO cells by means of equilibrium binding studies, showing an increase in affinity by rising the number of methylene units up to 7 and 9. Functional experiments on guinea-pig ileum and assessment of ERK1/2 phosphorylation on hM1, hM2 and hM3 on CHO cells have shown that the new compounds are endowed with muscarinic antagonistic properties. Kinetic binding studies have revealed that some of the tested compounds are able to slow the rate of dissociation of NMS, suggesting a bitopic behavior. Docking simulations, performed on the hM1 and hM2 receptors, give a sound rationalization of the experimental data revealing how these compounds are able to interact with both orthosteric and allosteric binding sites depending on the length of their connecting chain. Copyright © 2016 Elsevier Inc. All rights reserved.

Ultrathin SWCNT Films Enabled Multi-modal Fiber Sensors

DTIC Science & Technology

2014-09-30

Eq.  (12)  has  been  successfully  used   to  describe  the  length  dependent GEP  mobility for a variety of  biopolymers , such as DNAs with a broad...NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES...8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR

Formation of Monolayer Films by the Spontaneous Assembly of Organic Thiols from Solution onto Gold

DTIC Science & Technology

1988-09-01

we estimated a theoretical slope of 1.27 A per CH2 unit and an intercept of 4 A. The dashed line represents the thickness expected for a monolayer...a scale of only a few hundred angstroms--well below the length scale expected theoretically to give rise to hysteresis.31 ,78 Figure 4 plots contact... photoionization cross-sections calculated by Scofield117 , corrected for the dependence of the escape depth on the kinetic energy of the electrons (assumed to have

The role of skin biopsy in differentiating small-fiber neuropathy from ganglionopathy.

PubMed

Provitera, V; Gibbons, C H; Wendelschafer-Crabb, G; Donadio, V; Vitale, D F; Loavenbruck, A; Stancanelli, A; Caporaso, G; Liguori, R; Wang, N; Santoro, L; Kennedy, W R; Nolano, M

2018-06-01

We aimed to test the clinical utility of the leg:thigh intraepidermal nerve-fiber (IENF) density ratio as a parameter to discriminate between length-dependent small-fiber neuropathy (SFN) and small-fiber sensory ganglionopathy (SFSG) in subjects with signs and symptoms of small-fiber pathology. We retrospectively evaluated thigh and leg IENF density in 314 subjects with small-fiber pathology (173 with distal symmetrical length-dependent SFN and 141 with non-length-dependent SFSG). A group of 288 healthy subjects was included as a control group. The leg:thigh IENF density ratio was calculated for all subjects. We used receiver operating characteristic curve analyses to assess the ability of this parameter to discriminate between length-dependent SFN and SFSG, and the decision curve analysis to estimate its net clinical benefit. In patients with neuropathy, the mean IENF density was 14.8 ± 6.8/mm at the thigh (14.0 ± 6.9/mm in length-dependent SFN and 15.9 ± 6.7/mm in patients with SFSG) and 7.5 ± 4.5/mm at the distal leg (5.4 ± 3.2/mm in patients with length-dependent SFN and 10.1 ± 4.6/mm in patients with SFSG). The leg:thigh IENF density ratio was significantly (P < 0.01) lower in patients with length-dependent SFN (0.44 ± 0.23) compared with patients with SFSG (0.68 ± 0.28). The area under the curve of the receiver operating characteristic analysis to discriminate between patients with length-dependent SFN and SFSG was 0.79. The decision curve analysis demonstrated the clinical utility of this parameter. The leg:thigh IENF ratio represents a valuable tool in the differential diagnosis between SFSG and length-dependent SFN. © 2018 EAN.

Energy loss of fast quarks in nuclei.

PubMed

Johnson, M B; Kopeliovich, B Z; Potashnikova, I K; McGaughey, P L; Moss, J M; Peng, J C; Garvey, G T; Leitch, M J; Adams, M R; Alde, D M; Baer, H W; Barlett, M L; Brown, C N; Cooper, W E; Carey, T A; Danner, G; Hoffmann, G W; Hsiung, Y B; Kaplan, D M; Klein, A; Lee, C; Lillberg, J W; McCarthy, R L; Mishra, C S; Wang, M J

2001-05-14

We report an analysis of the nuclear dependence of the yield of Drell-Yan dimuons from the 800 GeV/c proton bombardment of 2H, C, Ca, Fe, and W targets. Employing a new formulation of the Drell-Yan process in the rest frame of the nucleus, this analysis examines the effect of initial-state energy loss and shadowing on the nuclear-dependence ratios versus the incident proton's momentum fraction and dimuon effective mass. The resulting energy loss per unit path length is -dE/dz = 2.32+/-0.52+/-0.5 GeV/fm. This is the first observation of a nonzero energy loss of partons traveling in a nuclear environment.

Octasaccharide is the minimal length unit required for efficient binding of cyclophilin B to heparin and cell surface heparan sulphate.

PubMed

Vanpouille, Christophe; Denys, Agnès; Carpentier, Mathieu; Pakula, Rachel; Mazurier, Joël; Allain, Fabrice

2004-09-01

Cyclophilin B (CyPB) is a heparin-binding protein first identified as a receptor for cyclosporin A. In previous studies, we reported that CyPB triggers chemotaxis and integrin-mediated adhesion of T-lymphocytes by way of interaction with two types of binding sites. The first site corresponds to a signalling receptor; the second site has been identified as heparan sulphate (HS) and appears crucial to induce cell adhesion. Characterization of the HS-binding unit is critical to understand the requirement of HS in pro-adhesive activity of CyPB. By using a strategy based on gel mobility shift assays with fluorophore-labelled oligosaccharides, we demonstrated that the minimal heparin unit required for efficient binding of CyPB is an octasaccharide. The mutants CyPB(KKK-) [where KKK- refers to the substitutions K3A(Lys3-->Ala)/K4A/K5A] and CyPB(DeltaYFD) (where Tyr14-Phe-Asp16 has been deleted) failed to interact with octasaccharides, confirming that the Y14FD16 and K3KK5 clusters are required for CyPB binding. Molecular modelling revealed that both clusters are spatially arranged so that they may act synergistically to form a binding site for the octasaccharide. We then demonstrated that heparin-derived octasaccharides and higher degree of polymerization oligosaccharides inhibited the interaction between CyPB and fluorophore-labelled HS chains purified from T-lymphocytes, and strongly reduced the HS-dependent pro-adhesive activity of CyPB. However, oligosaccharides or heparin were unable to restore adhesion of heparinase-treated T-lymphocytes, indicating that HS has to be present on the cell membrane to support the pro-adhesive activity of CyPB. Altogether, these results demonstrate that the octasaccharide is likely to be the minimal length unit required for efficient binding of CyPB to cell surface HS and consequent HS-dependent cell responses.

Octasaccharide is the minimal length unit required for efficient binding of cyclophilin B to heparin and cell surface heparan sulphate

PubMed Central

2004-01-01

Cyclophilin B (CyPB) is a heparin-binding protein first identified as a receptor for cyclosporin A. In previous studies, we reported that CyPB triggers chemotaxis and integrin-mediated adhesion of T-lymphocytes by way of interaction with two types of binding sites. The first site corresponds to a signalling receptor; the second site has been identified as heparan sulphate (HS) and appears crucial to induce cell adhesion. Characterization of the HS-binding unit is critical to understand the requirement of HS in pro-adhesive activity of CyPB. By using a strategy based on gel mobility shift assays with fluorophore-labelled oligosaccharides, we demonstrated that the minimal heparin unit required for efficient binding of CyPB is an octasaccharide. The mutants CyPBKKK− [where KKK− refers to the substitutions K3A(Lys3→Ala)/K4A/K5A] and CyPBΔYFD (where Tyr14-Phe-Asp16 has been deleted) failed to interact with octasaccharides, confirming that the Y14FD16 and K3KK5 clusters are required for CyPB binding. Molecular modelling revealed that both clusters are spatially arranged so that they may act synergistically to form a binding site for the octasaccharide. We then demonstrated that heparin-derived octasaccharides and higher degree of polymerization oligosaccharides inhibited the interaction between CyPB and fluorophore-labelled HS chains purified from T-lymphocytes, and strongly reduced the HS-dependent pro-adhesive activity of CyPB. However, oligosaccharides or heparin were unable to restore adhesion of heparinase-treated T-lymphocytes, indicating that HS has to be present on the cell membrane to support the pro-adhesive activity of CyPB. Altogether, these results demonstrate that the octasaccharide is likely to be the minimal length unit required for efficient binding of CyPB to cell surface HS and consequent HS-dependent cell responses. PMID:15109301

Understanding the length dependence of molecular junction thermopower.

PubMed

Karlström, Olov; Strange, Mikkel; Solomon, Gemma C

2014-01-28

Thermopower of molecular junctions is sensitive to details in the junction and may increase, decrease, or saturate with increasing chain length, depending on the system. Using McConnell's theory for exponentially suppressed transport together with a simple and easily interpretable tight binding model, we show how these different behaviors depend on the molecular backbone and its binding to the contacts. We distinguish between resonances from binding groups or undercoordinated electrode atoms, and those from the periodic backbone. It is demonstrated that while the former gives a length-independent contribution to the thermopower, possibly changing its sign, the latter determines its length dependence. This means that the question of which orbitals from the periodic chain that dominate the transport should not be inferred from the sign of the thermopower but from its length dependence. We find that the same molecular backbone can, in principle, show four qualitatively different thermopower trends depending on the binding group: It can be positive or negative for short chains, and it can either increase or decrease with length.

Modeling of a bimetallic eccentric cylindrical plasma waveguide based on a transmission line for TEM-mode

NASA Astrophysics Data System (ADS)

Golharani, Saeedeh; Jazi, Bahram; Jahanbakht, Sajad; Moeini-Nashalji, Azam

2018-07-01

In this paper, a plasma waveguide made of two eccentric cylindrical metallic walls have been studied according to the theory of transmission lines. The inductance per unit length L, the capacitance per unit length C, the resistance per unit length R and the shunt conductance per unit length G are obtained. The graphs of variations of the mentioned parameters vs. geometrical dimensions of waveguide are investigated. This investigations have been done for two different types of plasma waveguide. At first stage, plasma region will be considered in cold and collisional approximation and in second stage, a drift plasma in cold collisionless approximation will be considered. Also, graphs of phase velocity variation vs. the main parameters of the waveguide are presented.

A dynamic population model to investigate effects of climate and climate-independent factors on the lifecycle of the tick Amblyomma americanum (Acari: Ixodidae)

USGS Publications Warehouse

Ludwig, Antoinette; Ginsberg, Howard; Hickling, Graham J.; Ogden, Nicholas H.

2016-01-01

The lone star tick, Amblyomma americanum, is a disease vector of significance for human and animal health throughout much of the eastern United States. To model the potential effects of climate change on this tick, a better understanding is needed of the relative roles of temperature-dependent and temperature-independent (day-length-dependent behavioral or morphogenetic diapause) processes acting on the tick lifecycle. In this study, we explored the roles of these processes by simulating seasonal activity patterns using models with site-specific temperature and day-length-dependent processes. We first modeled the transitions from engorged larvae to feeding nymphs, engorged nymphs to feeding adults, and engorged adult females to feeding larvae. The simulated seasonal patterns were compared against field observations at three locations in United States. Simulations suggested that 1) during the larva-to-nymph transition, some larvae undergo no diapause while others undergo morphogenetic diapause of engorged larvae; 2) molted adults undergo behavioral diapause during the transition from nymph-to-adult; and 3) there is no diapause during the adult-to-larva transition. A model constructed to simulate the full lifecycle of A. americanum successfully predicted observed tick activity at the three U.S. study locations. Some differences between observed and simulated seasonality patterns were observed, however, identifying the need for research to refine some model parameters. In simulations run using temperature data for Montreal, deterministic die-out of A. americanum populations did not occur, suggesting the possibility that current climate in parts of southern Canada is suitable for survival and reproduction of this tick.

A Dynamic Population Model to Investigate Effects of Climate and Climate-Independent Factors on the Lifecycle of Amblyomma americanum (Acari: Ixodidae).

PubMed

Ludwig, Antoinette; Ginsberg, Howard S; Hickling, Graham J; Ogden, Nicholas H

2016-01-01

The lone star tick, Amblyomma americanum, is a disease vector of significance for human and animal health throughout much of the eastern United States. To model the potential effects of climate change on this tick, a better understanding is needed of the relative roles of temperature-dependent and temperature-independent (day-length-dependent behavioral or morphogenetic diapause) processes acting on the tick lifecycle. In this study, we explored the roles of these processes by simulating seasonal activity patterns using models with site-specific temperature and day-length-dependent processes. We first modeled the transitions from engorged larvae to feeding nymphs, engorged nymphs to feeding adults, and engorged adult females to feeding larvae. The simulated seasonal patterns were compared against field observations at three locations in United States. Simulations suggested that 1) during the larva-to-nymph transition, some larvae undergo no diapause while others undergo morphogenetic diapause of engorged larvae; 2) molted adults undergo behavioral diapause during the transition from nymph-to-adult; and 3) there is no diapause during the adult-to-larva transition. A model constructed to simulate the full lifecycle of A. americanum successfully predicted observed tick activity at the three U.S. study locations. Some differences between observed and simulated seasonality patterns were observed, however, identifying the need for research to refine some model parameters. In simulations run using temperature data for Montreal, deterministic die-out of A. americanum populations did not occur, suggesting the possibility that current climate in parts of southern Canada is suitable for survival and reproduction of this tick. © Crown copyright 2015.

Unexpected electronic perturbation effects of simple PEG environments on the optical properties of small cadmium chalcogenide clusters

NASA Astrophysics Data System (ADS)

Fukunaga, Naoto; Konishi, Katsuaki

2015-12-01

Poly(ethylene glycol) (PEG) has been widely used for the surface protection of inorganic nanoobjects because of its virtually `inert' nature, but little attention has been paid to its inherent electronic impacts on inorganic cores. Herein, we definitively show, through studies on optical properties of a series of PEG-modified Cd10Se4(SR)10 clusters, that the surrounding PEG environments can electronically affect the properties of the inorganic core. For the clusters with PEG units directly attached to an inorganic core (R = (CH2CH2O)nOCH3, 1-PEGn, n = 3, ~7, ~17, ~46), the absorption bands, associated with the low-energy transitions, continuously blue-shifted with the increasing PEG chain length. The chain length dependencies were also observed in the photoluminescence properties, particularly in the excitation spectral profiles. By combining the spectral features of several PEG17-modified clusters (2-Cm-PEG17 and 3) whose PEG and core units are separated by various alkyl chain-based spacers, it was demonstrated that sufficiently long PEG units, including PEG17 and PEG46, cause electronic perturbations in the cluster properties when they are arranged near the inorganic core. These unique effects of the long-PEG environments could be correlated with their large dipole moments, suggesting that the polarity of the proximal chemical environment is critical when affecting the electronic properties of the inorganic cluster core.Poly(ethylene glycol) (PEG) has been widely used for the surface protection of inorganic nanoobjects because of its virtually `inert' nature, but little attention has been paid to its inherent electronic impacts on inorganic cores. Herein, we definitively show, through studies on optical properties of a series of PEG-modified Cd10Se4(SR)10 clusters, that the surrounding PEG environments can electronically affect the properties of the inorganic core. For the clusters with PEG units directly attached to an inorganic core (R = (CH2CH2O)nOCH3, 1-PEGn, n = 3, ~7, ~17, ~46), the absorption bands, associated with the low-energy transitions, continuously blue-shifted with the increasing PEG chain length. The chain length dependencies were also observed in the photoluminescence properties, particularly in the excitation spectral profiles. By combining the spectral features of several PEG17-modified clusters (2-Cm-PEG17 and 3) whose PEG and core units are separated by various alkyl chain-based spacers, it was demonstrated that sufficiently long PEG units, including PEG17 and PEG46, cause electronic perturbations in the cluster properties when they are arranged near the inorganic core. These unique effects of the long-PEG environments could be correlated with their large dipole moments, suggesting that the polarity of the proximal chemical environment is critical when affecting the electronic properties of the inorganic cluster core. Electronic supplementary information (ESI) available: Details of synthetic procedures and characterisation data of the PEGylated thiols and clusters and additional absorption, photoluminescence emission and excitation spectral data. See DOI: 10.1039/c5nr06307h

Minimization of dependency length in written English.

PubMed

Temperley, David

2007-11-01

Gibson's Dependency Locality Theory (DLT) [Gibson, E. 1998. Linguistic complexity: locality of syntactic dependencies. Cognition, 68, 1-76; Gibson, E. 2000. The dependency locality theory: A distance-based theory of linguistic complexity. In A. Marantz, Y. Miyashita, & W. O'Neil (Eds.), Image, Language, Brain (pp. 95-126). Cambridge, MA: MIT Press.] proposes that the processing complexity of a sentence is related to the length of its syntactic dependencies: longer dependencies are more difficult to process. The DLT is supported by a variety of phenomena in language comprehension. This raises the question: Does language production reflect a preference for shorter dependencies as well? I examine this question in a corpus study of written English, using the Wall Street Journal portion of the Penn Treebank. The DLT makes a number of predictions regarding the length of constituents in different contexts; these predictions were tested in a series of statistical tests. A number of findings support the theory: the greater length of subject noun phrases in inverted versus uninverted quotation constructions, the greater length of direct-object versus subject NPs, the greater length of postmodifying versus premodifying adverbial clauses, the greater length of relative-clause subjects within direct-object NPs versus subject NPs, the tendency towards "short-long" ordering of postmodifying adjuncts and coordinated conjuncts, and the shorter length of subject NPs (but not direct-object NPs) in clauses with premodifying adjuncts versus those without.

Excitation energy migration processes in various multi-porphyrin assemblies.

PubMed

Yang, Jaesung; Kim, Dongho

2012-08-13

The electronic interactions and excitation energy transfer (EET) processes of a variety of multi-porphyrin arrays with linear, cyclic and box architectures have been explored. Directly meso-meso linked linear arrays (Z(N)) exhibit strong excitonic coupling with an exciton coherence length of approximately 6 porphyrin units, while fused linear arrays (T(N)) exhibit extensive π-conjugation over the whole array. The excitonic coherence length in directly linked cyclic porphyrin rings (CZ(N)) was determined to be approximately 2.7 porphyrin units by simultaneous analysis of fluorescence intensities and lifetimes at the single-molecule level. By performing transient absorption (TA) and TA anisotropy decay measurements, the EET rates in m-phenylene linked cyclic porphyrin wheels C12ZA and C24ZB were determined to be 4 and 36 ps(-1), respectively. With increasing the size of C(N)ZA, the EET efficiencies decrease owing to the structural distortions that produce considerable non-radiative decay pathways. Finally, the EET rates of self-assembled porphyrin boxes consisting of directly linked diporphyrins, B1A, B2A and B3A, are 48, 98 and 361 ps(-1), respectively. The EET rates of porphyrin boxes consisting of alkynylene-bridged diporphyrins, B2B and B4B, depend on the conformation of building blocks (planar or orthogonal) rather than the length of alkynylene linkers.

Quantifying Interfacial pH Variation at Molecular Length Scales Using a Concurrent Non-Faradaic Reaction.

PubMed

Ryu, Jaeyune; Wuttig, Anna; Surendranath, Yogesh

2018-05-15

We quantify changes in the interfacial pH local to the electrochemical double layer during electrocatalysis, using a concurrent non-faradaic probe reaction. In the absence of electrocatalysis, nanostructured Pt/C surfaces mediate the reaction of H2 with cis-2-butene-1,4-diol to form a mixture of 1,4-butanediol and n-butanol with a selectivity that is linearly dependent on the bulk solution pH. We show that kinetic branching occurs from a common surface-bound intermediate, ensuring that this probe reaction is uniquely sensitive to the interfacial pH within molecular length scales of the surface. We use the pH-dependent selectivity of this reaction to track changes in interfacial pH during concurrent hydrogen oxidation electrocatalysis and find that the local pH can vary dramatically, > 3 units, relative to the bulk value even at modest current densities in well-buffered electrolytes. This work highlights the key role that interfacial pH variation plays in modulating inner-sphere electrocatalysis. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

From Concrete to Abstract in the Measurement of Length

NASA Astrophysics Data System (ADS)

Stephanou, Andreas; Fisher, William P., Jr.

2013-09-01

The concatenation of units of length is widely viewed as the paradigmatic expression of fundamental measurement. Survey, assessment, and test scores in educational and psychological measurement are often interpreted in ways that assume a concatenation of units to have been established, even though these assumptions are rarely stated or tested. A concatenation model for measurement is shown to be equivalent to a Rasch model: any two units of measurement placed end to end must together be of the same length as either one of them added to itself. This additive principle and a concatenation model of measurement together serve as a heuristic guide for organizing two experimental approaches to calibrating instruments for measuring length. The capacity to reproduce the unit of measurement from theory with no need for repeated empirical calibration experiments, as in the geometrical bisection of the line and the resultant halving of the length measure, is highlighted as essential to demonstrating a thorough understanding of the construct.

Bisphenol A (BPA) binding on full-length architectures of estrogen receptor.

PubMed

Liu, Yaquan; Qu, Kaili; Hai, Ying; Zhao, Chunyan

2018-08-01

Previous research has shown that the major toxicity mechanism for many environment chemicals is binding with estrogen receptor (ER) and blocking endogenous estrogen access, including bisphenol A (BPA). However, the molecular level understanding the global consequence of BPA binding on the full-length architectures of ER is largely unknown, which is a necessary stage to evaluate estrogen-like toxicity of BPA. In the present work, the consequence of BPA on full-length architectures of ER was firstly modeled based on molecular dynamics, focusing on the cross communication between multi-domains including ligand binding domain (LBD) and DNA binding domain (DBD). The study proved consequence of BPA upon full-length ER structure was dependent on long-range communications between multiple protein domains. The allosteric effects occurring in LBD units could alter dimerization formation through a crucial change in residue-residue connections, which resulted in relaxation of DBD. It indicated BPA could present consequence on the full-size receptor, not only on the separate domains, but also on the cross communication among LBD, DBD, and DNA molecules. It might provide detailed insight into the knowledge about the structural characteristics of ER and its role in gene regulation, which eventually helped us evaluate the estrogen-like toxicity upon BPA binding with full-length ER. © 2018 Wiley Periodicals, Inc.

Factors Affecting the Length of Stay in the Intensive Care Unit: Our Clinical Experience

PubMed Central

Sengul Samanci, Nilay; Akkoc, İbrahim; Yucetas, Esma; Cebeci, Egemen; Ozturk, Savas

2018-01-01

Background and Aim Long hospital days in intensive care unit (ICU) due to life-threatening diseases are increasing in the world. The primary goal in ICU is to decrease length of stay in order to improve the quality of medical care and reduce cost. The aim of our study is to identify and categorize the factors associated with prolonged stays in ICU. Materials and Method We retrospectively analyzed 3925 patients. We obtained the patients' demographic, clinical, diagnostic, and physiologic variables; mortality; lengths of stay by examining the intensive care unit database records. Results The mean age of the study was 61.6 ± 18.9 years. The average length of stay in intensive care unit was 10.2 ± 25.2 days. The most common cause of hospitalization was because of multiple diseases (19.5%). The length of stay was positively correlated with urea, creatinine, and sodium. It was negatively correlated with uric acid and hematocrit levels. Length of stay was significantly higher in patients not operated on than in patients operated on (p < 0.001). Conclusion Our study showed a significantly increased length of stay in patients with cardiovascular system diseases, multiple diseases, nervous system diseases, and cerebrovascular diseases. Moreover we showed that when urea, creatinine, and sodium values increase, in parallel the length of stay increases. PMID:29750174

Fluoride sensing by catechol-based π-electron systems.

PubMed

An, Byeong-Kwan; Wang, Xin; Burn, Paul L; Meredith, Paul

2010-11-15

We have developed new catechol-based sensors that can detect fluoride via fluorescence or optical absorption even in the presence of other halides. The level and sensitivity of detection of the sensing molecules is dependent on the chromophore length, which is controlled by the number of thiophene units (one to three) within the chromophore. The sensor with three thiophene units, (E)-2-(2,2'-terthiophen-5-yl)-3-(3,4-dihydroxyphenyl)acrylonitrile, gives the best response to fluoride. By using fluorescence measurements fluoride is detectable over the concentration range 1.7 μM to 200 μM. Importantly, when adsorbed onto a solid support the fluorescent catechol dye can be used to detect the presence of fluoride in aqueous solution.

Wrapping conformations of a polymer on a curved surface

NASA Astrophysics Data System (ADS)

Lin, Cheng-Hsiao; Tsai, Yan-Chr; Hu, Chin-Kun

2007-03-01

The conformation of a polymer on a curved surface is high on the agenda for polymer science. We assume that the free energy of the system is the sum of bending energy of the polymer and the electrostatic attraction between the polymer and surface. As is also assumed, the polymer is very stiff with an invariant length for each segment so that we can neglect its tensile energy and view its length as a constant. Based on the principle of minimization of free energy, we apply a variation method with a locally undetermined Lagrange multiplier to obtain a set of equations for the polymer conformation in terms of local geometrical quantities. We have obtained some numerical solutions for the conformations of the polymer chain on cylindrical and ellipsoidal surfaces. With some boundary conditions, we find that the free energy profiles of polymer chains behave differently and depend on the geometry of the surface for both cases. In the former case, the free energy of each segment distributes within a narrower range and its value per unit length oscillates almost periodically in the azimuthal angle. However, in the latter case the free energy distributes in a wider range with larger value at both ends and smaller value in the middle of the chain. The structure of a polymer wrapping around an ellipsoidal surface is apt to dewrap a polymer from the endpoints. The dependence of threshold lengths for a polymer on the initially anchored positions is also investigated. With initial conditions, the threshold wrapping length is found to increase with the electrostatic attraction strength for the ellipsoidal surface case. When a polymer wraps around a sphere surface, the threshold length increases monotonically with the radius without the self-intersection configuration for a polymer. We also discuss potential applications of the present theory to DNA/protein complex and further researches on DNA on the curved surface.

Self-assembly behavior of poly(fluorenyl styrene)-block-poly(2-vinyl pyridine) and their blends with single wall carbon nanotubes (SWCNT)

NASA Astrophysics Data System (ADS)

Mezzenga, Raffaele; Li, Chaoxu; Hsu, Jung-Ching; Chen, Wen-Chang; Sugiyama, Kenji; Hirao, Akira

2010-03-01

We describe a supramolecular strategy to disperse carbon nanotubes in block copolymer matrices. To achieve the desired functions and morphologies, comb-type architectures in which one and two fluorene units attached on the styrene ring of polystyrene-block-poly(2-vinyl pyridine) were studied. Depending on the pendant fluorene units, the block ratio, the casting solvent and thermal annealing history, multiple morphologies were found. The phase diagram, compared to PS-b-P2VP, was interpreted in terms of the conformational asymmetry arising from grafting of fluorene units of variable lengths. Hydrogen bonds between COOH-SWCNT and P2VP favor miscibility of SWCNT within P2VP domains and the blending of these two components is reflected both on the final morphologies and on the electron conductivity of the blends.

'But one must not legalize the mentioned sin': Phenomenological vs. dynamical treatments of rods and clocks in Einstein's thought

NASA Astrophysics Data System (ADS)

Giovanelli, Marco

2014-11-01

This paper offers a historical overview of Einstein's vacillating attitude towards 'phenomenological' and 'dynamical' treatments of rods and clocks in relativity theory. In Einstein's view, a realistic microscopic model of rods and clocks was needed to account for the very existence of measuring devices of identical construction that always measure the same unit of time and the same unit of length. It will be shown that the empirical meaningfulness of both relativity theories depends on what, following Max Born, one might call the 'principle of the physical identity of the units of measure'. In an attempt to justify the validity of such a principle, Einstein was forced by different interlocutors, in particular Hermann Weyl and Wolfgang Pauli, to deal with the genuine epistemological, rather than the physical question of whether a theory should be required to describe the material devices needed for its own verification.

Modeling Stone Columns.

PubMed

Castro, Jorge

2017-07-11

This paper reviews the main modeling techniques for stone columns, both ordinary stone columns and geosynthetic-encased stone columns. The paper tries to encompass the more recent advances and recommendations in the topic. Regarding the geometrical model, the main options are the "unit cell", longitudinal gravel trenches in plane strain conditions, cylindrical rings of gravel in axial symmetry conditions, equivalent homogeneous soil with improved properties and three-dimensional models, either a full three-dimensional model or just a three-dimensional row or slice of columns. Some guidelines for obtaining these simplified geometrical models are provided and the particular case of groups of columns under footings is also analyzed. For the latter case, there is a column critical length that is around twice the footing width for non-encased columns in a homogeneous soft soil. In the literature, the column critical length is sometimes given as a function of the column length, which leads to some disparities in its value. Here it is shown that the column critical length mainly depends on the footing dimensions. Some other features related with column modeling are also briefly presented, such as the influence of column installation. Finally, some guidance and recommendations are provided on parameter selection for the study of stone columns.

Modeling Stone Columns

PubMed Central

2017-01-01

This paper reviews the main modeling techniques for stone columns, both ordinary stone columns and geosynthetic-encased stone columns. The paper tries to encompass the more recent advances and recommendations in the topic. Regarding the geometrical model, the main options are the “unit cell”, longitudinal gravel trenches in plane strain conditions, cylindrical rings of gravel in axial symmetry conditions, equivalent homogeneous soil with improved properties and three-dimensional models, either a full three-dimensional model or just a three-dimensional row or slice of columns. Some guidelines for obtaining these simplified geometrical models are provided and the particular case of groups of columns under footings is also analyzed. For the latter case, there is a column critical length that is around twice the footing width for non-encased columns in a homogeneous soft soil. In the literature, the column critical length is sometimes given as a function of the column length, which leads to some disparities in its value. Here it is shown that the column critical length mainly depends on the footing dimensions. Some other features related with column modeling are also briefly presented, such as the influence of column installation. Finally, some guidance and recommendations are provided on parameter selection for the study of stone columns. PMID:28773146

Outcomes of telemedicine intervention in a regional intensive care unit: a before and after study.

PubMed

Panlaqui, O M; Broadfield, E; Champion, R; Edington, J P; Kennedy, S

2017-09-01

Telemedicine consultations in remote intensive care units (ICUs) overseas were found to be effective in reducing mortality and hospital length of stay (LOS). In Australia, there were anecdotal reports of these clinical outcomes. This retrospective before and after study assessed the improvement in patient outcomes with the implementation of a telemedicine program in a regional high dependency unit. Daily virtual consultations were conducted between the rural facility and the intensivists at the regional centre. A total of 525 patients received intensive care support between 2010 and 2015. Hospital and High Dependency Unit mortality showed no evidence of significant differences between the telemedicine group and the baseline (relative risk 1.02, 95% confidence interval [CI] 0.99-1.06, P =0.25 and relative risk 1.00, 95% CI 0.98-1.03, P =0.67 respectively). The hospital LOS was lower in the baseline group by 1.5 days. There was no significant difference in High Dependency Unit LOS. To adjust for the covariates in LOS, log linear regression analysis was performed. The telemedicine intervention, Acute Physiology and Chronic Health Evaluation II scores and inter-hospital transfers were found to contribute significantly to hospital LOS. The most important result of the study was that the proportion of inter-hospital transfers was lower in the telemedicine group (relative risk 0.88, 95% CI 0.80-0.98, P =0.03) compared to baseline. This means that critically ill patients in our regional centre can continue to receive specialist care remotely through tele-ICU consultations thus avoiding the need for patient transport. However, further study is needed to establish the benefits and risks of telemedicine intervention in ICUs in Australia.

Muscle force loss and soreness subsequent to maximal eccentric contractions depend on the amount of fascicle strain in vivo.

PubMed

Guilhem, G; Doguet, V; Hauraix, H; Lacourpaille, L; Jubeau, M; Nordez, A; Dorel, S

2016-06-01

Defining the origins of muscle injury has important rehabilitation and exercise applications. However, current knowledge of muscle damage mechanics in human remains unclear in vivo. This study aimed to determine the relationships between muscle-tendon unit mechanics during maximal eccentric contractions and the extent of subsequent functional impairments induced by muscle damage. The length of the muscle-tendon unit, fascicles and tendinous tissues was continuously measured on the gastrocnemius medialis using ultrasonography, in time with torque, during 10 sets of 30 maximal eccentric contractions of plantar flexors at 45°s(-1) , in seventeen participants. Muscle-tendon unit, fascicles and tendinous tissues were stretched up to 4.44 ± 0.33 cm, 2.31 ± 0.64 cm and 1.92 ± 0.61 cm respectively. Fascicle stretch length, lengthening amplitude and negative fascicle work beyond slack length were significantly correlated with the force decrease 48 h post-exercise (r = 0.51, 0.47 and 0.68, respectively; P < 0.05). This study demonstrates that the strain applied to human muscle fibres during eccentric contractions strongly influences the magnitude of muscle damage in vivo. Achilles tendon compliance decreases the amount of strain, while architectural gear ratio may moderately contribute to attenuating muscle fascicle lengthening and hence muscle damage. Further studies are necessary to explore the impact of various types of task to fully understand the contribution of muscle-tendon interactions during active lengthening to muscle damage. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

PEG-poly(amino acid) block copolymer micelles for tunable drug release.

PubMed

Ponta, Andrei; Bae, Younsoo

2010-11-01

To achieve tunable pH-dependent drug release in tumor tissues. Poly(ethylene glycol)-poly(aspartic acid) [PEG-p(Asp)] containing 12 kDa PEG and pAsp (5, 15, and 35 repeating units) were prepared. Hydrazide linkers with spacers [glycine (Gly) and 4-aminobenzoate (Abz)] were introduced to PEG-p(Asp), followed by drug conjugation [doxorubicin (DOX)]. The block copolymer-drug conjugates were either reconstituted or dialyzed in aqueous solutions to prepare micelles. Drug release patterns were observed under sink conditions at pH 5.0 and 7.4, 37°C, for 48 h. A collection of six block copolymers with different chain lengths and spacers was synthesized. Drug binding yields were 13-43.6%. The polymer-drug conjugates formed <50 nm polymer micelles irrespective of polymer compositions. Gly-introduced polymer micelles showed marginal change in particle size (40 ± 10 nm), while the size of Abz-micelles increased gradually from 10 to 40 nm as the polymer chain lengths increased. Drug release patterns of both Gly and Abz micelles were pH-dependent and tunable. The spacers appear to play a crucial role in controlling drug release and stability of polymer micelles in combination with block copolymer chain lengths. A drug delivery platform for tunable drug release was successfully developed with polymer micelles possessing spacer-modified hydrazone drug-binding linkers.

Defects in Nonlinear Elastic Crystals: Differential Geometry, Finite Kinematics, and Second-Order Analytical Solutions

DTIC Science & Technology

2015-04-01

of unit length: da = F L a αδ α Ad A , da = F L−1αaδ A α dA . (2.12) The metric tensor associated with the deformed... A spatial density tensor θ and Frank vector ω̂ of the following forms are consistent with geometry of the problem: θ = θzzgz ⊗ gz = ω̂δ(r)gz ⊗ gz = δ...stress depends quadratically on strain, with the elastic potential cubic in strain and including elastic constants of

Modeling and characterization of shielded low loss CPWs on 65 nm node silicon

NASA Astrophysics Data System (ADS)

Hongrui, Wang; Dongxu, Yang; Li, Zhang; Lei, Zhang; Zhiping, Yu

2011-06-01

Coplanar waveguides (CPWs) are promising candidates for high quality passive devices in millimeter-wave frequency bands. In this paper, CPW transmission lines with and without ground shields have been designed and fabricated on 65 nm CMOS technology. A physical-based model is proposed to describe the frequency-dependent per-unit-length L, C, R and G parameters. Starting with a basic CPW structure, the slow-wave effect and ground-shield influence have been analyzed and incorporated into the general model. The accuracy of the model is confirmed by experimental results.

Artificial neural network predictions of lengths of stay on a post-coronary care unit.

PubMed

Mobley, B A; Leasure, R; Davidson, L

1995-01-01

To create and validate a model that predicts length of hospital unit stay. Ex post facto. Seventy-four independent admission variables in 15 general categories were utilized to predict possible stays of 1 to 20 days. Laboratory. Records of patients discharged from a post-coronary care unit in early 1993. An artificial neural network was trained on 629 records and tested on an additional 127 records of patients. The absolute disparity between the actual lengths of stays in the test records and the predictions of the network averaged 1.4 days per record, and the actual length of stay was predicted within 1 day 72% of the time. The artificial neural network demonstrated the capacity to utilize common patient admission characteristics to predict lengths of stay. This technology shows promise in aiding timely initiation of treatment and effective resource planning and cost control.

Implementation and evaluation of a clinical pathway for TRAM breast reconstruction.

PubMed

Hwang, T G; Wilkins, E G; Lowery, J C; Gentile, J

2000-02-01

Among strategies recently proposed to reduce practice variation, promote quality, and control costs in health care delivery, the concept of the clinical pathway has received considerable attention. Because transverse rectus abdominis musculocutaneous (TRAM) breast reconstruction is a common and often costly intervention, this institution sought to evaluate cost and quality outcomes of a clinical pathways program for this procedure. The TRAM reconstruction clinical pathway was implemented in April of 1996 to standardize postoperative care in this patient population. Outcomes of consecutive pathway cases for the first 14 months of the program were assessed in a retrospective cohort design, by using all nonpathway TRAM cases from the 18 months immediately before pathway implementation as controls. Outcomes assessed included length of hospital stay, postoperative complications, total postoperative charges, and total postoperative costs in relative value units. Data on these dependent variables were collected from hospital charts and billing records. The effects of pathway implementation on the outcomes of interest were analyzed by using analysis of covariance to control for potential confounding by other independent variables, including surgical site (unilateral versus bilateral reconstructions), technique (pedicle versus free TRAMs), timing (immediate versus delayed reconstructions), and patient age. Finally, a comparison of variances in the outcomes of interest between the two groups was analyzed by using an Ftest. For all statistical tests, p values of < or = 0.05 were considered significant. Twenty-nine patients were treated in the TRAM pathway group, whereas the control population included 40 nonpathway patients. After implementation of the TRAM pathway, length of stay decreased from 6.0 to 5.2 days; total postoperative charges were reduced from $8587 to $7744; and total postoperative relative value unit utilization declined from 1686 to 1104. Analysis of covariance showed that the decreases in length of hospital stay and relative value units in the TRAM pathway were statistically significant (p = 0.05 and p = 0.007, respectively). By contrast, no significant increase in complications was observed after pathway implementation. Variability in the TRAM pathway group, as measured by SD, decreased significantly for both length of hospital stay (p = 0.039) and relative value units (p = 0.023). Implementation of the TRAM reconstruction clinical pathway resulted in significant declines in length of hospital stay and total costs. These decreases in resource utilization had no significant effect on postoperative complication rates. Although additional research is needed to further assess the impact of clinical pathways, this approach offers considerable promise for improving the cost-effectiveness of health care.

Investigations on Laser Beam Welding of Different Dissimilar Joints of Steel and Aluminum Alloys for Automotive Lightweight Construction

NASA Astrophysics Data System (ADS)

Seffer, Oliver; Pfeifer, Ronny; Springer, André; Kaierle, Stefan

Due to the enormous potential of weight saving, and the consequential reduction of pollutant emissions, the use of hybrid components made of steel and aluminum alloys is increasing steadily, especially concerning automotive lightweight construction. However, thermal joining of steel and aluminum is still being researched, due to a limited solubility of the binary system of iron and aluminum causing the formation of hard and brittle intermetallic phases, which decrease the strength and the formability of the dissimilar seam. The presented results show the investigation of laser beam welding for joining different dissimilar hybrid components of the steel materials HX220LAD+Z100, 22MnB5+AS150 and 1.4301, as well as the aluminum alloy AA6016-T4 as a lap joint. Among other things, the influences of the energy per unit length, the material grade, the sheet thickness t, the weld type (lap weld, fillet weld) and the arrangement of the base materials in a lap joint (aluminum-sided irradiation, steel-sided irradiation) on the achievable strengths are analyzed. The characterization of the dissimilar joints includes tensile shear tests and metallographic analyses, depending on the energy per unit length.

Parallel design of JPEG-LS encoder on graphics processing units

NASA Astrophysics Data System (ADS)

Duan, Hao; Fang, Yong; Huang, Bormin

2012-01-01

With recent technical advances in graphic processing units (GPUs), GPUs have outperformed CPUs in terms of compute capability and memory bandwidth. Many successful GPU applications to high performance computing have been reported. JPEG-LS is an ISO/IEC standard for lossless image compression which utilizes adaptive context modeling and run-length coding to improve compression ratio. However, adaptive context modeling causes data dependency among adjacent pixels and the run-length coding has to be performed in a sequential way. Hence, using JPEG-LS to compress large-volume hyperspectral image data is quite time-consuming. We implement an efficient parallel JPEG-LS encoder for lossless hyperspectral compression on a NVIDIA GPU using the computer unified device architecture (CUDA) programming technology. We use the block parallel strategy, as well as such CUDA techniques as coalesced global memory access, parallel prefix sum, and asynchronous data transfer. We also show the relation between GPU speedup and AVIRIS block size, as well as the relation between compression ratio and AVIRIS block size. When AVIRIS images are divided into blocks, each with 64×64 pixels, we gain the best GPU performance with 26.3x speedup over its original CPU code.

Mid-21st- century climate changes increase predicted fire occurrence and fire season length, Northern Rocky Mountains, United States

Treesearch

Karin L. Riley; Rachel A. Loehman

2016-01-01

Climate changes are expected to increase fire frequency, fire season length, and cumulative area burned in the western United States. We focus on the potential impact of mid-21st- century climate changes on annual burn probability, fire season length, and large fire characteristics including number and size for a study area in the Northern Rocky Mountains....

Microwave absorption in substances that form hydration layers with water

NASA Astrophysics Data System (ADS)

Garner, H. R.; Ohkawa, T.; Tuason, O.; Lee, R. L.

1990-12-01

The microwave absorption of certain water soluble polymers (polyethylene glycol, polyvinyl pyrrolidone, proteins, and DNA) in solution is composed of three parts: absorption in the free water, absorption in the substance, and absorption in the hydration layer. Ethanol, sucrose, glycerol, and sodium acetate, which form weak hydrogen bonds or have an ionic nature in aqueous solutions, also have microwave absorption signatures similar to polymers that form hydration layers. The frequency-dependent absorption of the free water and of the hydration layer water is described by a simple Debye relaxation model. The absorption per unit sample volume attributable to the hydration layer is solute concentration dependent, and a simple model is used to describe the dependence. The hydration-layer relaxation time was found to vary from substance to substance and with solute concentration. The relaxation time was also found to be independent of solute length.

Immunonutrition - the influence of early postoperative glutamine supplementation in enteral/parenteral nutrition on immune response, wound healing and length of hospital stay in multiple trauma patients and patients after extensive surgery.

PubMed

Lorenz, Kai J; Schallert, Reiner; Daniel, Volker

2015-01-01

In the postoperative phase, the prognosis of multiple trauma patients with severe brain injuries as well as of patients with extensive head and neck surgery mainly depends on protein metabolism and the prevention of septic complications. Wound healing problems can also result in markedly longer stays in the intensive care unit and general wards. As a result, the immunostimulation of patients in the postoperative phase is expected to improve their immunological and overall health. A study involving 15 patients with extensive ENT tumour surgery and 7 multiple-trauma patients investigated the effect of enteral glutamine supplementation on immune induction, wound healing and length of hospital stay. Half of the patients received a glutamine-supplemented diet. The control group received an isocaloric, isonitrogenous diet. In summary, we found that total lymphocyte counts, the percentage of activated CD4+DR+ T helper lymphocytes, the in-vitro response of lymphocytes to mitogens, as well as IL-2 plasma levels normalised faster in patients who received glutamine-supplemented diets than in patients who received isocaloric, isonitrogenous diets and that these parameters were even above normal by the end of the second postoperative week. We believe that providing critically ill patients with a demand-oriented immunostimulating diet is fully justified as it reduces septic complications, accelerates wound healing, and shortens the length of ICU (intensive care unit) and general ward stays.

Repetition rate multiplication of frequency comb using all-pass fiber resonator

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

Yang, Lijun; Yang, Honglei; Zhang, Hongyuan

2016-09-15

We propose a stable method for repetition rate multiplication of a 250-MHz Er-fiber frequency comb by a phase-locked all-pass fiber ring resonator, whose phase-locking configuration is simple. The optical path length of the fiber ring resonator is automatically controlled to be accurately an odd multiple of half of the original cavity length using an electronical phase-locking unit with an optical delay line. As for shorter cavity length of the comb, high-order odd multiple is preferable. Because the power loss depends only on the net-attenuation of the fiber ring resonator, the energetic efficiency of the proposed method is high. The inputmore » and output optical spectrums show that the spectral width of the frequency comb is clearly preserved. Besides, experimental results show less pulse intensity fluctuation and 35 dB suppression ratio of side-modes while providing a good long-term and short-term frequency stability. Higher-order repetition rate multiplication to several GHz can be obtained by using several fiber ring resonators in cascade configuration.« less

Factors associated with ureteral burn injury from an electrified guidewire.

PubMed

Capello, Seth A; Gordetsky, Jennifer; Erturk, Erdal; Yao, Jorge; Joseph, Jean V

2008-06-01

During ureteroscopic procedures, electrocautery is often utilized in the presence of an intra-ureteral guidewire. Inadvertent electrification of the guidewire may occur if the active electrode comes into contact with the guidewire, potentially resulting in a ureteral burn injury. This study investigates under what conditions electrification of a ureteral guidewire would result in ureteral burn injury. Porcine kidney/ureter units were tested in a saline bath using a guidewire within the ureter. The collecting system was filled with either saline or water and the guidewire was electrified with varying power and mode settings. The contact area between the wire and ureter was adjusted to 1/2 or 1/4 of the total ureteral length. The ureters were then inspected for evidence of burn injury microscopically by a pathologist in a blinded fashion. Ten kidney/ureter units were tested. Four units were filled with saline and none of these demonstrated any burn injury. Six kidney/ureter units were filled with water prior to electrification of the wire. Small amounts of burned tissue were noted in those with the full length of the ureter exposed. Moderate to severe burning was present in those with 1/2 of the ureter exposed. Ureters exposed to 120-W cutting current had more injury than those exposed to 80-W coagulation current. Inadvertent electrification of a ureteral guidewire does not necessarily result in ureteral burn injury. The presence and extent of ureteral injury depends primarily on the irrigating fluid used, as well as the amount of ureter exposed to the electrified guidewire.

Optimal parameters of leader development in lightning

NASA Technical Reports Server (NTRS)

Petrov, N. I.; Petrova, G. N.

1991-01-01

The dependences between the different parameters of a leader in lightning are obtained theoretically. The physical mechanism of the instability leading to the formation of the streamer zone is proposed. The instability has the wave nature and is caused by the self-influence effects of the space charge. Using a stability condition of the leader propagation, a dependence is obtained between the current across the leader head and its velocity of motion. The dependence of the streamer zone length on the gap length is also obtained. It is shown that the streamer zone length is saturated with the increasing of the gap length. A comparison between the obtained dependences and the experimental data is presented.

Determining the transfer length in prestressed concrete railroad ties produced in the United States.

DOT National Transportation Integrated Search

2012-05-01

This paper presents results from transfer length measurements on prestressed concrete railroad ties. Results are shown from : the four main producers of concrete ties in the United States. Six prestressed concrete tie plants were visited by the : res...

Stalk-length-dependence of the contractility of Vorticella convallaria

NASA Astrophysics Data System (ADS)

Gul Chung, Eun; Ryu, Sangjin

2017-12-01

Vorticella convallaria is a sessile protozoan of which the spasmoneme contracts on a millisecond timescale. Because this contraction is induced and powered by the binding of calcium ions (Ca2+), the spasmoneme showcases Ca2+-powered cellular motility. Because the isometric tension of V. convallaria increases linearly with its stalk length, it is hypothesized that the contractility of V. convallaria during unhindered contraction depends on the stalk length. In this study, the contractile force and energetics of V. convallaria cells of different stalk lengths were evaluated using a fluid dynamic drag model which accounts for the unsteadiness and finite Reynolds number of the water flow caused by contracting V. convallaria and the wall effect of the no-slip substrate. It was found that the contraction displacement, peak contraction speed, peak contractile force, total mechanical work, and peak power depended on the stalk length. The observed stalk-length-dependencies were simulated using a damped spring model, and the model estimated that the average spring constant of the contracting stalk was 1.34 nN µm-1. These observed length-dependencies of Vorticella’s key contractility parameters reflect the biophysical mechanism of the spasmonemal contraction, and thus they should be considered in developing a theoretical model of the Vorticella spasmoneme.

Synchronization in a chaotic neural network with time delay depending on the spatial distance between neurons

NASA Astrophysics Data System (ADS)

Tang, Guoning; Xu, Kesheng; Jiang, Luoluo

2011-10-01

The synchronization is investigated in a two-dimensional Hindmarsh-Rose neuronal network by introducing a global coupling scheme with time delay, where the length of time delay is proportional to the spatial distance between neurons. We find that the time delay always disturbs synchronization of the neuronal network. When both the coupling strength and length of time delay per unit distance (i.e., enlargement factor) are large enough, the time delay induces the abnormal membrane potential oscillations in neurons. Specifically, the abnormal membrane potential oscillations for the symmetrically placed neurons form an antiphase, so that the large coupling strength and enlargement factor lead to the desynchronization of the neuronal network. The complete and intermittently complete synchronization of the neuronal network are observed for the right choice of parameters. The physical mechanism underlying these phenomena is analyzed.

Large-scale evidence of dependency length minimization in 37 languages

PubMed Central

Futrell, Richard; Mahowald, Kyle; Gibson, Edward

2015-01-01

Explaining the variation between human languages and the constraints on that variation is a core goal of linguistics. In the last 20 y, it has been claimed that many striking universals of cross-linguistic variation follow from a hypothetical principle that dependency length—the distance between syntactically related words in a sentence—is minimized. Various models of human sentence production and comprehension predict that long dependencies are difficult or inefficient to process; minimizing dependency length thus enables effective communication without incurring processing difficulty. However, despite widespread application of this idea in theoretical, empirical, and practical work, there is not yet large-scale evidence that dependency length is actually minimized in real utterances across many languages; previous work has focused either on a small number of languages or on limited kinds of data about each language. Here, using parsed corpora of 37 diverse languages, we show that overall dependency lengths for all languages are shorter than conservative random baselines. The results strongly suggest that dependency length minimization is a universal quantitative property of human languages and support explanations of linguistic variation in terms of general properties of human information processing. PMID:26240370

GFP-based fluorescence assay for CAG repeat instability in cultured human cells.

PubMed

Santillan, Beatriz A; Moye, Christopher; Mittelman, David; Wilson, John H

2014-01-01

Trinucleotide repeats can be highly unstable, mutating far more frequently than point mutations. Repeats typically mutate by addition or loss of units of the repeat. CAG repeat expansions in humans trigger neurological diseases that include myotonic dystrophy, Huntington disease, and several spinocerebellar ataxias. In human cells, diverse mechanisms promote CAG repeat instability, and in mice, the mechanisms of instability are varied and tissue-dependent. Dissection of mechanistic complexity and discovery of potential therapeutics necessitates quantitative and scalable screens for repeat mutation. We describe a GFP-based assay for screening modifiers of CAG repeat instability in human cells. The assay exploits an engineered intronic CAG repeat tract that interferes with expression of an inducible GFP minigene. Like the phenotypes of many trinucleotide repeat disorders, we find that GFP function is impaired by repeat expansion, in a length-dependent manner. The intensity of fluorescence varies inversely with repeat length, allowing estimates of repeat tract changes in live cells. We validate the assay using transcription through the repeat and engineered CAG-specific nucleases, which have previously been reported to induce CAG repeat instability. The assay is relatively fast and should be adaptable to large-scale screens of chemical and shRNA libraries.

GFP-Based Fluorescence Assay for CAG Repeat Instability in Cultured Human Cells

PubMed Central

Santillan, Beatriz A.; Moye, Christopher; Mittelman, David; Wilson, John H.

2014-01-01

Trinucleotide repeats can be highly unstable, mutating far more frequently than point mutations. Repeats typically mutate by addition or loss of units of the repeat. CAG repeat expansions in humans trigger neurological diseases that include myotonic dystrophy, Huntington disease, and several spinocerebellar ataxias. In human cells, diverse mechanisms promote CAG repeat instability, and in mice, the mechanisms of instability are varied and tissue-dependent. Dissection of mechanistic complexity and discovery of potential therapeutics necessitates quantitative and scalable screens for repeat mutation. We describe a GFP-based assay for screening modifiers of CAG repeat instability in human cells. The assay exploits an engineered intronic CAG repeat tract that interferes with expression of an inducible GFP minigene. Like the phenotypes of many trinucleotide repeat disorders, we find that GFP function is impaired by repeat expansion, in a length-dependent manner. The intensity of fluorescence varies inversely with repeat length, allowing estimates of repeat tract changes in live cells. We validate the assay using transcription through the repeat and engineered CAG-specific nucleases, which have previously been reported to induce CAG repeat instability. The assay is relatively fast and should be adaptable to large-scale screens of chemical and shRNA libraries. PMID:25423602

Standardization of methods of expressing lengths and weights of fish

USGS Publications Warehouse

Hile, Ralph

1948-01-01

Fishery workers in the United States and Canada are unable to think readily in terms of the metric system of weights and measurements. Even long experience does not make it possible to form a clear idea as to the actual size of fish for which lengths and weights are given in metric units, without first converting to the English system. A more general adoption of the English system of weights and measurements in fishery work is recommended. The use of English units exclusively is suggested for articles of a popular or semi-popular nature, but in more formal publications the key information, at least, should be recorded in both systems. In highly technical papers metric units alone may prove satisfactory. Agreement is also lacking as to which length measurement of fish is suited best for uniform adoption. The total length is recommended here for the reason that it is the only measurement that includes all of the fish. This length is defined as the distance from the tip of the head (jaws closed) to the tip of the tail with the lobes compressed so as to give the maximum possible measurement.

Dialysis Dependence Predicts Complications, Intensive Care Unit Care, Length of Stay, and Skilled Nursing Needs in Elective Primary Total Knee and Hip Arthroplasty.

PubMed

Patterson, Joseph T; Tillinghast, Kyle; Ward, Derek

2018-07-01

Limited data describe risks and perioperative resource needs of total joint arthroplasty (TJA) in dialysis-dependent patients. Retrospective multiple cohort analysis of dialysis-dependent American College of Surgeons National Surgical Quality Improvement Program patients undergoing primary elective total hip and knee arthroplasty compared to non-dialysis-dependent controls from 2005 to 2015. Relative risks (RRs) of 30-day adverse events were determined by multivariate regression adjusting for baseline differences. Six hundred forty-five (0.2%) dialysis-dependent patients of 342,730 TJA patients were dialysis-dependent and more likely to be dependent, under weight, anemic, hypoalbuminemic, and have cardiopulmonary disease. In total hip arthroplasty patients, dialysis was associated with greater risk of any adverse event (RR = 1.1, P < .001), mortality (RR = 2.8, P = .012), intensive care unit (ICU) care (RR = 9.8, P < .001), discharge to facility (RR = 1.3, P < .001), and longer admission (1.5×, P < .001). In total knee arthroplasty patients, dialysis conferred greater risk of any adverse event (RR = 1.1, P < .001), ICU care (RR = 6.0, P < .001), stroke (RR = 7.6, P < .001), cardiac arrest (RR = 4.8, P = .014), discharge to facility (RR = 1.5, P < .001), readmission (RR = 1.8, P = .002), and longer admission (1.3×, P < .001). Dialysis-dependence is an independent risk factor for 30-day adverse events, ICU care, longer admission, and rehabilitation needs in TJA patients. Thirty days is not sufficient to detect infectious complications among these patients. These findings inform shared decision-making, perioperative resource planning, and risk adjustment under alternative reimbursement models. Copyright © 2018 Elsevier Inc. All rights reserved.

A Technique for Mapping Characteristic Lengths to Preserve Energy Dissipated via Strain Softening in a Multiscale Analysis

NASA Technical Reports Server (NTRS)

Pineda, Evan J.; Bednarcyk, Brett A.; Arnold, Steven M.

2014-01-01

It is often advantageous to account for the microstructure of the material directly using multiscale modeling. For computational tractability, an idealized repeating unit cell (RUC) is used to capture all of the pertinent features of the microstructure. Typically, the RUC is dimensionless and depends only on the relative volume fractions of the different phases in the material. This works well for non-linear and inelastic behavior exhibiting a positive-definite constitutive response. Although, once the material exhibits strain softening, or localization, a mesh objective failure theories, such as smeared fracture theories, nodal and element enrichment theories (XFEM), cohesive elements or virtual crack closure technique (VCCT), can be utilized at the microscale, but the dimensions of the RUC must then be defined. One major challenge in multiscale progressive damage modeling is relating the characteristic lengths across the scales in order to preserve the energy that is dissipated via localization at the microscale. If there is no effort to relate the size of the macroscale element to the microscale RUC, then the energy that is dissipated will remain mesh dependent at the macroscale, even if it is regularized at the microscale. Here, a technique for mapping characteristic lengths across the scales is proposed. The RUC will be modeled using the generalized method of cells (GMC) micromechanics theory, and local failure in the matrix constituent subcells will be modeled using the crack band theory. The subcell characteristic lengths used in the crack band calculations will be mapped to the macroscale finite element in order to regularize the local energy in a manner consistent with the global length scale. Examples will be provided with and without the regularization, and they will be compared to a baseline case where the size and shape of the element and RUC are coincident (ensuring energy is preserved across the scales).

Role of hyaluronan chain length in buffering interstitial flow across synovium in rabbits

PubMed Central

Coleman, P J; Scott, D; Mason, R M; Levick, J R

2000-01-01

Synovial fluid drains out of joints through an interstitial pathway. Hyaluronan, the major polysaccharide of synovial fluid, attenuates this fluid drainage; it creates a graded opposition to outflow that increases with pressure (outflow ‘buffering’). This has been attributed to size-related molecular reflection at the interstitium-fluid interface. Chain length is reduced in inflammatory arthritis. We therefore investigated the dependence of outflow buffering on hyaluronan chain length.Hyaluronan molecules of mean molecular mass ≈2200, 530, 300 and 90 kDa and concentration 3.6 mg ml−1 were infused into the knees of anaesthetized rabbits, with Ringer solution as control in the contralateral joint. Trans-synovial drainage rate was recorded at known joint pressures. Pressure was raised in steps every 30–60 min (range 2–24 cmH2O).With hyaluronan-90 and hyaluronan-300 the fluid drainage rate was reduced relative to Ringer solution (P < 0.001, ANOVA) but increased steeply with pressure. The opposition to outflow, defined as the pressure required to drive unit outflow, did not increase with pressure, i.e. there was no outflow buffering.With hyaluronan-530 and hyaluronan-2000 the fluid drainage rate became relatively insensitive to pressure, causing a near plateau of flow. Opposition to outflow increased markedly with pressure, by up to 3.3 times over the explored pressures.Hyaluronan concentration in the joint cavity increased over the drainage period, indicating partial reflection of hyaluronan by synovial interstitium. Reflected fractions were 0.12, 0.33, 0.25 and 0.79 for hyaluronan-90, -300, -530 and -2200, respectively.Thus the flow-buffering effect of hyaluronan depended on chain length, and shortening the chains reduced the degree of molecular reflection. The latter should reduce the concentration polarization at the tissue interface, and hence the local osmotic pressure opposing fluid drainage. In rheumatoid arthritis the reduced chain length will facilitate the escape of hyaluronan and fluid. PMID:10896731

A model for attenuation and scattering in the Earth's crust

NASA Astrophysics Data System (ADS)

Toksöz, M. Nafi; Dainty, Anton M.; Reiter, Edmund; Wu, Ru-Shan

1988-03-01

The mechanisms contributing to the attenuation of earthquake ground motion in the distance range of 10 to 200 km are studied with the aid of laboratory data, coda waves Rg attenuation, strong motion attenuation measurements in the northeast United States and Canada, and theoretical models. The frequency range 1 10 Hz has been studied. The relative contributions to attenuation of anelasticity of crustal rocks (constant Q), fluid flow and scattering are evaluated. Scattering is found to be strong with an albedo B 0=0.8 0.9 and a scattering extinction length of 17 32 km. The albedo is defined as the ratio of the total extinction length to the scattering extinction length. The Rg results indicate that Q increases with depth in the upper kilometer or two of the crust, at least in New England. Coda Q appears to be equivalent to intrinsic (anelastic) Q and indicates that this Q increases with frequency as Q=Q o f n , where n is in the range of 0.2 0.9. The intrinsic attenuation in the crust can be explained by a high constant Q (500≤ Q o≤2000) and a frequency dependent mechanism most likely due to fluid effects in rocks and cracks. A fluid-flow attenuation model gives a frequency dependence ( Q≃ Q o f 0.5) similar to those determined from the analysis of coda waves of regional seismograms. Q is low near the surface and high in the body of the crust.

Oligosaccharide Substrate Preferences of Human Extracellular Sulfatase Sulf2 Using Liquid Chromatography-Mass Spectrometry Based Glycomics Approaches

PubMed Central

Huang, Yu; Mao, Yang; Buczek-Thomas, Jo Ann; Nugent, Matthew A.; Zaia, Joseph

2014-01-01

Sulfs are extracellular endosulfatases that selectively remove the 6-O-sulfate groups from cell surface heparan sulfate (HS) chain. By altering the sulfation at these particular sites, Sulfs function to remodel HS chains. As a result of the remodeling activity, HSulf2 regulates a multitude of cell-signaling events that depend on interactions between proteins and HS. Previous efforts to characterize the substrate specificity of human Sulfs (HSulfs) focused on the analysis of HS disaccharides and synthetic repeating units. In this study, we characterized the substrate preferences of human HSulf2 using HS oligosaccharides with various lengths and sulfation degrees from several naturally occurring HS sources by applying liquid chromatography mass spectrometry based glycomics methods. The results showed that HSulf2 preferentially digests highly sulfated HS oligosaccharides with zero acetyl groups and this preference is length dependent. In terms of length of oligosaccharides, HSulf2 digestion induced more sulfation decrease on DP6 (DP: degree of polymerization) compared to DP2, DP4 and DP8. In addition, the HSulf2 preferentially digests the oligosaccharide domain located at the non-reducing end (NRE) of the HS and heparin chain. In addition, the HSulf2 digestion products were altered only for specific isomers. HSulf2 treated NRE oligosaccharides also showed greater decrease in cell proliferation than those from internal domains of the HS chain. After further chromatographic separation, we identified the three most preferred unsaturated hexasaccharide for HSulf2. PMID:25127119

Association between length of storage of red blood cell units and outcome of critically ill children: a prospective observational study

PubMed Central

2010-01-01

Introduction Transfusion is a common treatment in pediatric intensive care units (PICUs). Studies in adults suggest that prolonged storage of red blood cell units is associated with worse clinical outcome. No prospective study has been conducted in children. Our objectives were to assess the clinical impact of the length of storage of red blood cell units on clinical outcome of critically ill children. Methods Prospective, observational study conducted in 30 North American centers, in consecutive patients aged <18 years with a stay ≥ 48 hours in a PICU. The primary outcome measure was the incidence of multiple organ dysfunction syndrome after transfusion. The secondary outcomes were 28-day mortality and PICU length of stay. Odds ratios were adjusted for gender, age, number of organ dysfunctions at admission, total number of transfusions, and total dose of transfusion, using a multiple logistic regression model. Results The median length of storage was 14 days in 296 patients with documented length of storage. For patients receiving blood stored ≥ 14 days, the adjusted odds ratio for an increased incidence of multiple organ dysfunction syndrome was 1.87 (95% CI 1.04;3.27, P = 0.03). There was also a significant difference in the total PICU length of stay (adjusted median difference +3.7 days, P < 0.001) and no significant change in mortality. Conclusions In critically ill children, transfusion of red blood cell units stored for ≥ 14 days is independently associated with an increased occurrence of multiple organ dysfunction syndrome and prolonged PICU stay. PMID:20377853

Variability and trends in dry day frequency and dry event length in the southwestern United States

USGS Publications Warehouse

McCabe, Gregory J.; Legates, David R.; Lins, Harry F.

2010-01-01

Daily precipitation from 22 National Weather Service first-order weather stations in the southwestern United States for water years 1951 through 2006 are used to examine variability and trends in the frequency of dry days and dry event length. Dry events with minimum thresholds of 10 and 20 consecutive days of precipitation with less than 2.54 mm are analyzed. For water years and cool seasons (October through March), most sites indicate negative trends in dry event length (i.e., dry event durations are becoming shorter). For the warm season (April through September), most sites also indicate negative trends; however, more sites indicate positive trends in dry event length for the warm season than for water years or cool seasons. The larger number of sites indicating positive trends in dry event length during the warm season is due to a series of dry warm seasons near the end of the 20th century and the beginning of the 21st century. Overall, a large portion of the variability in dry event length is attributable to variability of the El Niño–Southern Oscillation, especially for water years and cool seasons. Our results are consistent with analyses of trends in discharge for sites in the southwestern United States, an increased frequency in El Niño events, and positive trends in precipitation in the southwestern United States.

Length dependence of force generation exhibit similarities between rat cardiac myocytes and skeletal muscle fibres.

PubMed

Hanft, Laurin M; McDonald, Kerry S

2010-08-01

According to the Frank-Starling relationship, increased ventricular volume increases cardiac output, which helps match cardiac output to peripheral circulatory demand. The cellular basis for this relationship is in large part the myofilament length-tension relationship. Length-tension relationships in maximally calcium activated preparations are relatively shallow and similar between cardiac myocytes and skeletal muscle fibres. During twitch activations length-tension relationships become steeper in both cardiac and skeletal muscle; however, it remains unclear whether length dependence of tension differs between striated muscle cell types during submaximal activations. The purpose of this study was to compare sarcomere length-tension relationships and the sarcomere length dependence of force development between rat skinned left ventricular cardiac myocytes and fast-twitch and slow-twitch skeletal muscle fibres. Muscle cell preparations were calcium activated to yield 50% maximal force, after which isometric force and rate constants (k(tr)) of force development were measured over a range of sarcomere lengths. Myofilament length-tension relationships were considerably steeper in fast-twitch fibres compared to slow-twitch fibres. Interestingly, cardiac myocyte preparations exhibited two populations of length-tension relationships, one steeper than fast-twitch fibres and the other similar to slow-twitch fibres. Moreover, myocytes with shallow length-tension relationships were converted to steeper length-tension relationships by protein kinase A (PKA)-induced myofilament phosphorylation. Sarcomere length-k(tr) relationships were distinct between all three cell types and exhibited patterns markedly different from Ca(2+) activation-dependent k(tr) relationships. Overall, these findings indicate cardiac myocytes exhibit varied length-tension relationships and sarcomere length appears a dominant modulator of force development rates. Importantly, cardiac myocyte length-tension relationships appear able to switch between slow-twitch-like and fast-twitch-like by PKA-mediated myofibrillar phosphorylation, which implicates a novel means for controlling Frank-Starling relationships.

Merchantable sawlog and bole-length equations for the Northeastern United States

Treesearch

Daniel A. Yaussy; Martin E. Dale; Martin E. Dale

1991-01-01

A modified Richards growth model is used to develop species-specific coefficients for equations estimating the merchantable sawlog and bole lengths of trees from 25 species groups common to the Northeastern United States. These regression coefficients have been incorporated into the growth-and-yield simulation software, NE-TWIGS.

Dual tunneling-unit scanning tunneling microscope for length measurement based on crystalline lattice

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

Zhang, H.; Higuchi, T.; Nishioki, N.

1997-01-01

A dual tunneling-unit scanning tunneling microscope (DTU STM) was developed for nm order length measurement with wide scan range. The crystalline lattice of highly oriented pyrolitic graphite (HOPG) was used as reference scale. A reference unit was set up on top of a test unit. The reference sample holder and the probe tip of test unit were attached to one single XY scanner on either surface, while the test sample holder was open. This enables simultaneous acquisition of wide images of HOPG and test sample. The length in test sample image was measured by counting the number of HOPG lattices.more » An inchworm actuator and an impact drive mechanism were introduced to roughly position probe tips. The XY scanner was designed to be elastic to eliminate image distortion. Some comparison experiments using two HOPG chips were carried out in air. The DTU STM is confirmed to be a stable and more powerful device for length measurement which has nanometer accuracy when covering a wide scan range up to several micrometers, and is capable of measuring comparatively large and heavy samples. {copyright} {ital 1997 American Vacuum Society.}« less

Retirada do leito após a descontinuação da ventilação mecânica: há repercussão na mortalidade e no tempo de permanência na unidade de terapia intensiva?

PubMed

Soares, Thiago Rios; Avena, Kátia de Miranda; Olivieri, Flávia Milholo; Feijó, Luciana Ferreira; Mendes, Kristine Menezes Barberino; Souza Filho, Sydney Agareno de; Gomes, André Mansur de Carvalho Guanaes

2010-03-01

To describe the withdrawal of the bed frequency in mechanic ventilation patients and its impact on mortality and length of stay in the intensive care unit. This was a retrospective cohort study in mechanical ventilation patients. Clinical and epidemiological variables, withdrawal of bed related motor therapy, intensive care unit length of stay and mortality were evaluated. We studied 91 patients, mean age of 62.5± 18.8 years, predominantly female (52%) and mean intensive care unit length of stay of 07 days (95% CI, 8-13 days). Considering the withdrawal of the bed or not, no difference was observed between groups regarding length of stay in intensive care unit. Patients who were withdrawn of bed had a lower clinical severity. Their mortality rate was 29.7%. The not withdrawn of bed group had higher both actual and expected mortality. Patients withdrawn of bed following mechanical ventilation discontinuation showed lower mortality. It is suggested that early intensive care unit mobilization and withdrawal of bed should be stimulated.

Dependence of Ion Dynamics on the Polymer Chain Length in Poly(ethylene oxide)-Based Polymer Electrolytes.

PubMed

Chattoraj, Joyjit; Knappe, Marisa; Heuer, Andreas

2015-06-04

It is known from experiments that in the polymer electrolyte system, which contains poly(ethylene oxide) chains (PEO), lithium-cations (Li(+)), and bis(trifluoromethanesulfonyl)imide-anions (TFSI(-)), the cation and the anion diffusion and the ionic conductivity exhibit a similar chain-length dependence: with increasing chain length, they start dropping steadily, and later, they saturate to constant values. These results are surprising because Li-cations are strongly correlated with the polymer chains, whereas TFSI-anions do not have such bonding. To understand this phenomenon, we perform molecular dynamics simulations of this system for four different polymer chain lengths. The diffusion results obtained from our simulations display excellent agreement with the experimental data. The cation transport model based on the Rouse dynamics can successfully quantify the Li-diffusion results, which correlates Li diffusion with the polymer center-of-mass motion and the polymer segmental motion. The ionic conductivity as a function of the chain length is then estimated based on the chain-length-dependent ion diffusion, which shows a temperature-dependent deviation for short chain lengths. We argue that in the first regime, counterion correlations modify the conductivity, whereas for the long chains, the system behaves as a strong electrolyte.

History-dependence of muscle slack length following contraction and stretch in the human vastus lateralis.

PubMed

Stubbs, Peter W; Walsh, Lee D; D'Souza, Arkiev; Héroux, Martin E; Bolsterlee, Bart; Gandevia, Simon C; Herbert, Robert D

2018-06-01

In reduced muscle preparations, the slack length and passive stiffness of muscle fibres have been shown to be influenced by previous muscle contraction or stretch. In human muscles, such behaviours have been inferred from measures of muscle force, joint stiffness and reflex magnitudes and latencies. Using ultrasound imaging, we directly observed that isometric contraction of the vastus lateralis muscle at short lengths reduces the slack lengths of the muscle-tendon unit and muscle fascicles. The effect is apparent 60 s after the contraction. These observations imply that muscle contraction at short lengths causes the formation of bonds which reduce the effective length of structures that generate passive tension in muscles. In reduced muscle preparations, stretch and muscle contraction change the properties of relaxed muscle fibres. In humans, effects of stretch and contraction on properties of relaxed muscles have been inferred from measurements of time taken to develop force, joint stiffness and reflex latencies. The current study used ultrasound imaging to directly observe the effects of stretch and contraction on muscle-tendon slack length and fascicle slack length of the human vastus lateralis muscle in vivo. The muscle was conditioned by (a) strong isometric contractions at long muscle-tendon lengths, (b) strong isometric contractions at short muscle-tendon lengths, (c) weak isometric contractions at long muscle-tendon lengths and (d) slow stretches. One minute after conditioning, ultrasound images were acquired from the relaxed muscle as it was slowly lengthened through its physiological range. The ultrasound image sequences were used to identify muscle-tendon slack angles and fascicle slack lengths. Contraction at short muscle-tendon lengths caused a mean 13.5 degree (95% CI 11.8-15.0 degree) shift in the muscle-tendon slack angle towards shorter muscle-tendon lengths, and a mean 5 mm (95% CI 2-8 mm) reduction in fascicle slack length, compared to the other conditions. A supplementary experiment showed the effect could be demonstrated if the muscle was conditioned by contraction at short lengths but not if the relaxed muscle was held at short lengths, confirming the role of muscle contraction. These observations imply that muscle contraction at short lengths causes the formation of bonds which reduce the effective length of structures that generate passive tension in muscles. © 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.

Electrowetting-driven variable-focus microlens on flexible surfaces

NASA Astrophysics Data System (ADS)

Li, Chenhui; Jiang, Hongrui

2012-06-01

We demonstrate a flexible, electrowetting-driven, variable-focus liquid microlens. The microlens is fabricated using a soft polymer polydimethylsiloxane. The lens can be smoothly wrapped onto a curved surface. A low-temperature fabrication process was developed to reduce the stress on and to avoid any damage to the polymer. The focal length of the microlens varies between -15.0 mm to +28.0 mm, depending on the applied voltage. The resolving power of the microlens is 25.39 line pairs per mm using a 1951 United States Air Force resolution chart. The typical response time of the lens is around 50 ms.

Ballistic heat conduction and mass disorder in one dimension.

PubMed

Ong, Zhun-Yong; Zhang, Gang

2014-08-20

It is well-known that in the disordered harmonic chain, heat conduction is subballistic and the thermal conductivity (κ) scales asymptotically as lim(L--> ∞) κ ∝ L(0.5) where L is the chain length. However, using the nonequilibrium Green's function (NEGF) method and analytical modelling, we show that there exists a critical crossover length scale (LC) below which ballistic heat conduction (κ ∝ L) can coexist with mass disorder. This ballistic-to-subballistic heat conduction crossover is connected to the exponential attenuation of the phonon transmittance function Ξ i.e. Ξ(ω, L) = exp[-L/λ(ω)], where λ is the frequency-dependent attenuation length. The crossover length can be determined from the minimum attenuation length, which depends on the maximum transmitted frequency. We numerically determine the dependence of the transmittance on frequency and mass composition as well as derive a closed form estimate, which agrees closely with the numerical results. For the length-dependent thermal conductance, we also derive a closed form expression which agrees closely with numerical results and reproduces the ballistic to subballistic thermal conduction crossover. This allows us to characterize the crossover in terms of changes in the length, mass composition and temperature dependence, and also to determine the conditions under which heat conduction enters the ballistic regime. We describe how the mass composition can be modified to increase ballistic heat conduction.

Designing Drug Conjugates Based on Sugar Decorated V-Shape and Star Polymethacrylates: Influence of Composition and Architecture of Polymeric Carrier.

PubMed

Mielańczyk, Anna; Neugebauer, Dorota

2015-12-16

Amphiphilic ethylenediamine (EDA)-functionalized V-shape and star copolymers with centrally placed methyl-α,D-glucopyranoside were designed as nanocarriers. Anticancer doxorubicin (DOX) was conjugated in water via amine groups in copolymers to form ketimine linkers. Variations of arm length and number (40-65 units per arm and 2 vs 3 vs 4 arms), DOX feed amount, and conjugation site content (50-160 units of EDA groups), as responsible for efficiency of drug attachment (10-60 units of conjugated DOX) and its release at various pH (5.0 vs 7.4), were studied to demonstrate potential for drug delivery. Size of conjugate particles (10-195 nm) formed in aqueous solution was strongly dependent on the polymer composition and topology. The broad range of drug amounts (25-95%) were detected by the precipitation method, showing pH sensitivity by some polymeric conjugates with faster DOX release in acidic conditions.

Computationally efficient models of neuromuscular recruitment and mechanics.

PubMed

Song, D; Raphael, G; Lan, N; Loeb, G E

2008-06-01

We have improved the stability and computational efficiency of a physiologically realistic, virtual muscle (VM 3.*) model (Cheng et al 2000 J. Neurosci. Methods 101 117-30) by a simpler structure of lumped fiber types and a novel recruitment algorithm. In the new version (VM 4.0), the mathematical equations are reformulated into state-space representation and structured into a CMEX S-function in SIMULINK. A continuous recruitment scheme approximates the discrete recruitment of slow and fast motor units under physiological conditions. This makes it possible to predict force output during smooth recruitment and derecruitment without having to simulate explicitly a large number of independently recruited units. We removed the intermediate state variable, effective length (Leff), which had been introduced to model the delayed length dependency of the activation-frequency relationship, but which had little effect and could introduce instability under physiological conditions of use. Both of these changes greatly reduce the number of state variables with little loss of accuracy compared to the original VM. The performance of VM 4.0 was validated by comparison with VM 3.1.5 for both single-muscle force production and a multi-joint task. The improved VM 4.0 model is more suitable for the analysis of neural control of movements and for design of prosthetic systems to restore lost or impaired motor functions. VM 4.0 is available via the internet and includes options to use the original VM model, which remains useful for detailed simulations of single motor unit behavior.

Computationally efficient models of neuromuscular recruitment and mechanics

NASA Astrophysics Data System (ADS)

Song, D.; Raphael, G.; Lan, N.; Loeb, G. E.

2008-06-01

We have improved the stability and computational efficiency of a physiologically realistic, virtual muscle (VM 3.*) model (Cheng et al 2000 J. Neurosci. Methods 101 117-30) by a simpler structure of lumped fiber types and a novel recruitment algorithm. In the new version (VM 4.0), the mathematical equations are reformulated into state-space representation and structured into a CMEX S-function in SIMULINK. A continuous recruitment scheme approximates the discrete recruitment of slow and fast motor units under physiological conditions. This makes it possible to predict force output during smooth recruitment and derecruitment without having to simulate explicitly a large number of independently recruited units. We removed the intermediate state variable, effective length (Leff), which had been introduced to model the delayed length dependency of the activation-frequency relationship, but which had little effect and could introduce instability under physiological conditions of use. Both of these changes greatly reduce the number of state variables with little loss of accuracy compared to the original VM. The performance of VM 4.0 was validated by comparison with VM 3.1.5 for both single-muscle force production and a multi-joint task. The improved VM 4.0 model is more suitable for the analysis of neural control of movements and for design of prosthetic systems to restore lost or impaired motor functions. VM 4.0 is available via the internet and includes options to use the original VM model, which remains useful for detailed simulations of single motor unit behavior.

Perturbed length-dependent activation in human hypertrophic cardiomyopathy with missense sarcomeric gene mutations.

PubMed

Sequeira, Vasco; Wijnker, Paul J M; Nijenkamp, Louise L A M; Kuster, Diederik W D; Najafi, Aref; Witjas-Paalberends, E Rosalie; Regan, Jessica A; Boontje, Nicky; Ten Cate, Folkert J; Germans, Tjeerd; Carrier, Lucie; Sadayappan, Sakthivel; van Slegtenhorst, Marjon A; Zaremba, Ruud; Foster, D Brian; Murphy, Anne M; Poggesi, Corrado; Dos Remedios, Cris; Stienen, Ger J M; Ho, Carolyn Y; Michels, Michelle; van der Velden, Jolanda

2013-05-24

High-myofilament Ca(2+) sensitivity has been proposed as a trigger of disease pathogenesis in familial hypertrophic cardiomyopathy (HCM) on the basis of in vitro and transgenic mice studies. However, myofilament Ca(2+) sensitivity depends on protein phosphorylation and muscle length, and at present, data in humans are scarce. To investigate whether high myofilament Ca(2+) sensitivity and perturbed length-dependent activation are characteristics for human HCM with mutations in thick and thin filament proteins. Cardiac samples from patients with HCM harboring mutations in genes encoding thick (MYH7, MYBPC3) and thin (TNNT2, TNNI3, TPM1) filament proteins were compared with sarcomere mutation-negative HCM and nonfailing donors. Cardiomyocyte force measurements showed higher myofilament Ca(2+) sensitivity in all HCM samples and low phosphorylation of protein kinase A (PKA) targets compared with donors. After exogenous PKA treatment, myofilament Ca(2+) sensitivity was similar (MYBPC3mut, TPM1mut, sarcomere mutation-negative HCM), higher (MYH7mut, TNNT2mut), or even significantly lower (TNNI3mut) compared with donors. Length-dependent activation was significantly smaller in all HCM than in donor samples. PKA treatment increased phosphorylation of PKA-targets in HCM myocardium and normalized length-dependent activation to donor values in sarcomere mutation-negative HCM and HCM with truncating MYBPC3 mutations but not in HCM with missense mutations. Replacement of mutant by wild-type troponin in TNNT2mut and TNNI3mut corrected length-dependent activation to donor values. High-myofilament Ca(2+) sensitivity is a common characteristic of human HCM and partly reflects hypophosphorylation of PKA targets compared with donors. Length-dependent sarcomere activation is perturbed by missense mutations, possibly via posttranslational modifications other than PKA hypophosphorylation or altered protein-protein interactions, and represents a common pathomechanism in HCM.

Mechanical properties of regular porous biomaterials made from truncated cube repeating unit cells: Analytical solutions and computational models.

PubMed

Hedayati, R; Sadighi, M; Mohammadi-Aghdam, M; Zadpoor, A A

2016-03-01

Additive manufacturing (AM) has enabled fabrication of open-cell porous biomaterials based on repeating unit cells. The micro-architecture of the porous biomaterials and, thus, their physical properties could then be precisely controlled. Due to their many favorable properties, porous biomaterials manufactured using AM are considered as promising candidates for bone substitution as well as for several other applications in orthopedic surgery. The mechanical properties of such porous structures including static and fatigue properties are shown to be strongly dependent on the type of the repeating unit cell based on which the porous biomaterial is built. In this paper, we study the mechanical properties of porous biomaterials made from a relatively new unit cell, namely truncated cube. We present analytical solutions that relate the dimensions of the repeating unit cell to the elastic modulus, Poisson's ratio, yield stress, and buckling load of those porous structures. We also performed finite element modeling to predict the mechanical properties of the porous structures. The analytical solution and computational results were found to be in agreement with each other. The mechanical properties estimated using both the analytical and computational techniques were somewhat higher than the experimental data reported in one of our recent studies on selective laser melted Ti-6Al-4V porous biomaterials. In addition to porosity, the elastic modulus and Poisson's ratio of the porous structures were found to be strongly dependent on the ratio of the length of the inclined struts to that of the uninclined (i.e. vertical or horizontal) struts, α, in the truncated cube unit cell. The geometry of the truncated cube unit cell approaches the octahedral and cube unit cells when α respectively approaches zero and infinity. Consistent with those geometrical observations, the analytical solutions presented in this study approached those of the octahedral and cube unit cells when α approached respectively 0 and infinity. Copyright © 2015 Elsevier B.V. All rights reserved.

Thick Filament Length and Isoform Composition Determine Self-Organized Contractile Units in Actomyosin Bundles

PubMed Central

Thoresen, Todd; Lenz, Martin; Gardel, Margaret L.

2013-01-01

Diverse myosin II isoforms regulate contractility of actomyosin bundles in disparate physiological processes by variations in both motor mechanochemistry and the extent to which motors are clustered into thick filaments. Although the role of mechanochemistry is well appreciated, the extent to which thick filament length regulates actomyosin contractility is unknown. Here, we study the contractility of minimal actomyosin bundles formed in vitro by mixtures of F-actin and thick filaments of nonmuscle, smooth, and skeletal muscle myosin isoforms with varied length. Diverse myosin II isoforms guide the self-organization of distinct contractile units within in vitro bundles with shortening rates similar to those of in vivo myofibrils and stress fibers. The tendency to form contractile units increases with the thick filament length, resulting in a bundle shortening rate proportional to the length of constituent myosin thick filament. We develop a model that describes our data, providing a framework in which to understand how diverse myosin II isoforms regulate the contractile behaviors of disordered actomyosin bundles found in muscle and nonmuscle cells. These experiments provide insight into physiological processes that use dynamic regulation of thick filament length, such as smooth muscle contraction. PMID:23442916

Effect of Variable Chord Length on Transonic Axial Rotor Performance Investigated

NASA Technical Reports Server (NTRS)

Suder, Kenneth L.

2002-01-01

During the life of any gas turbine, blade erosion is present, especially for those units that are exposed to unfiltered air, such as aviation turbofan engines. The effect of this erosion is to reduce the blade chord progressively from the midspan to the tip region and to roughen and distort the blade surface. The effects of roughness on rotor performance have been documented by Suder et al. and Roberts. These papers indicate that the penalty for leading-edge roughness and erosion can be significant. Turbofan operators, therefore, restore chord length at routine maintenance intervals to regain performance before deterioration is too severe to salvage blades. As the rotor blades erode, the leading edge becomes rough - blunt and distorted from the nominal shape - and the aerodynamic performance suffers. Nominal performance can be recovered by recontouring the leading edges. This process, which inherently shortens the blade chord, can be used until the blade chord erodes to the stall limit. Below this chord length, which varies among engine-compressor types, a decrease of stall margin is likely. After compressor blade rework that includes leading edge recontouring, the blades have different chord lengths, ranging from blades that are near nominal chord length down to those near the stall chord limit. Furthermore, as blades erode below the stall limit, they must be replaced with new blades that have the full nominal chord length. Consequently, a set of compressor blades with varying chord lengths will be installed into each turbofan engine that goes through a complete maintenance cycle. The question arises, "Does fan or compressor performance depend on the order in which mixed-chord blades are installed into a fan or compressor disk?"

The scaling of urban surface water abundance and impairment with city size

NASA Astrophysics Data System (ADS)

Steele, M. K.

2018-03-01

Urbanization alters surface water compared to nonurban landscapes, yet little is known regarding how basic aquatic ecosystem characteristics, such as the abundance and impairment of surface water, differ with population size or regional context. This study examined the abundance, scaling, and impairment of surface water by quantifying the stream length, water body area, and impaired stream length for 3520 cities in the United States with populations from 2500 to 18 million. Stream length, water body area, and impaired stream length were quantified using the National Hydrography Dataset and the EPA's 303(d) list. These metrics were scaled with population and city area using single and piecewise power-law models and related to biophysical factors (precipitation, topography) and land cover. Results show that abundance of stream length and water body area in cities actually increases with city area; however, the per person abundance decreases with population size. Relative to population, impaired stream length did not increase until city populations were > 25,000 people, then scaled linearly with population. Some variation in abundance and impairment was explained by biophysical context and land cover. Development intensity correlated with stream density and impairment; however, those relationships depended on the orientation of the land covers. When high intensity development occupied the local elevation highs (+ 15 m) and undeveloped land the elevation lows, the percentage of impaired streams was less than the opposite land cover orientation (- 15 m) or very flat land. These results show that surface water abundance and impairment across contiguous US cities are influenced by city size and by biophysical setting interacting with land cover intensity.

Comparing Observations, 1st Experimental Edition.

ERIC Educational Resources Information Center

Butts, David P.

Objectives for this module include the ability to: (1) order objects by comparing a property which the objects have in common (such as length, area, volume or mass), (2) describe objects (length, area, volume, mass, etc.) by comparing them quantitatively using either arbitrary units of comparison or standard units of comparison, and (3) describe…

Solving the negative impact of congestion in the postanesthesia care unit: a cost of opportunity analysis.

PubMed

Ruiz-Patiño, Alejandro; Acosta-Ospina, Laura Elena; Rueda, Juan-David

2017-04-01

Congestion in the postanesthesia care unit (PACU) leads to the formation of waiting queues for patients being transferred after surgery, negatively affecting hospital resources. As patients recover in the operating room, incoming surgeries are delayed. The purpose of this study was to establish the impact of this phenomenon in multiple settings. An operational mathematical study based on the queuing theory was performed. Average queue length, average queue waiting time, and daily queue waiting time were evaluated. Calculations were based on the mean patient daily flow, PACU length of stay, occupation, and current number of beds. Data was prospectively collected during a period of 2 months, and the entry and exit time was recorded for each patient taken to the PACU. Data was imputed in a computational model made with MS Excel. To account for data uncertainty, deterministic and probabilistic sensitivity analyses for all dependent variables were performed. With a mean patient daily flow of 40.3 and an average PACU length of stay of 4 hours, average total lost surgical opportunity time was estimated at 2.36 hours (95% CI: 0.36-4.74 hours). Cost of opportunity was calculated at $1592 per lost hour. Sensitivity analysis showed that an increase of two beds is required to solve the queue formation. When congestion has a negative impact on cost of opportunity in the surgical setting, queuing analysis grants definitive actions to solve the problem, improving quality of service and resource utilization. Copyright © 2016 Elsevier Inc. All rights reserved.

Testing a model of componential processing of multi-symbol numbers-evidence from measurement units.

PubMed

Huber, Stefan; Bahnmueller, Julia; Klein, Elise; Moeller, Korbinian

2015-10-01

Research on numerical cognition has addressed the processing of nonsymbolic quantities and symbolic digits extensively. However, magnitude processing of measurement units is still a neglected topic in numerical cognition research. Hence, we investigated the processing of measurement units to evaluate whether typical effects of multi-digit number processing such as the compatibility effect, the string length congruity effect, and the distance effect are also present for measurement units. In three experiments, participants had to single out the larger one of two physical quantities (e.g., lengths). In Experiment 1, the compatibility of number and measurement unit (compatible: 3 mm_6 cm with 3 < 6 and mm < cm; incompatible: 3 cm_6 mm with 3 < 6 but cm > mm) as well as string length congruity (congruent: 1 m_2 km with m < km and 2 < 3 characters; incongruent: 2 mm_1 m with mm < m, but 3 > 2 characters) were manipulated. We observed reliable compatibility effects with prolonged reaction times (RT) for incompatible trials. Moreover, a string length congruity effect was present in RT with longer RT for incongruent trials. Experiments 2 and 3 served as control experiments showing that compatibility effects persist when controlling for holistic distance and that a distance effect for measurement units exists. Our findings indicate that numbers and measurement units are processed in a componential manner and thus highlight that processing characteristics of multi-digit numbers generalize to measurement units. Thereby, our data lend further support to the recently proposed generalized model of componential multi-symbol number processing.

The Scales of Time, Length, Mass, Energy, and Other Fundamental Physical Quantities in the Atomic World and the Use of Atomic Units in Quantum Mechanical Calculations

ERIC Educational Resources Information Center

Teo, Boon K.; Li, Wai-Kee

2011-01-01

This article is divided into two parts. In the first part, the atomic unit (au) system is introduced and the scales of time, space (length), and speed, as well as those of mass and energy, in the atomic world are discussed. In the second part, the utility of atomic units in quantum mechanical and spectroscopic calculations is illustrated with…

Change in muscle fascicle length influences the recruitment and discharge rate of motor units during isometric contractions.

PubMed

Pasquet, Benjamin; Carpentier, Alain; Duchateau, Jacques

2005-11-01

This study examines the effect of fascicle length change on motor-unit recruitment and discharge rate in the human tibialis anterior (TA) during isometric contractions of various intensities. The torque produced during dorsiflexion and the surface and intramuscular electromyograms (EMGs) from the TA were recorded in eight subjects. The behavior of the same motor unit (n = 59) was compared at two ankle joint angles (+10 and -10 degrees around the ankle neutral position). Muscle fascicle length of the TA was measured noninvasively using ultrasonography recordings. When the ankle angle was moved from 10 degrees plantarflexion to 10 degrees dorsiflexion, the torque produced during maximal voluntary contraction (MVC) was significantly reduced [35.2 +/- 3.3 vs. 44.3 +/- 4.2 (SD) Nm; P < 0.001] and the average surface EMG increased (0.47 +/- 0.08 vs. 0.43 +/- 0.06 mV; P < 0.05). At reduced ankle joint angle, muscle fascicle length declined by 12.7% (P < 0.01) at rest and by 18.9% (P < 0.001) during MVC. Motor units were activated at a lower recruitment threshold for short compared with long muscle fascicle length, either when expressed in absolute values (2.1 +/- 2.5 vs. 3.6 +/- 3.7 Nm; P < 0.001) or relative to their respective MVC (5.2 +/- 6.1 vs. 8.8 +/- 9.0%). Higher discharge rate and additional motor-unit recruitment were observed at a given absolute or relative torque when muscle fascicles were shortened. However, the data indicate that increased rate coding was mainly present at low torque level (<10% MVC), when the muscle-tendon complex was compliant, whereas recruitment of additional motor units played a dominant role at higher torque level and decreased compliance (10-35% MVC). Taken together, the results suggest that the central command is modulated by the afferent proprioceptive information during submaximal contractions performed at different muscle fascicle lengths.

Deflate decompressor

DOEpatents

Hamlet, Jason R [Albuquerque, NM; Robertson, Perry J [Albuquerque, NM; Pierson, Lyndon G [Albuquerque, NM; Olsberg, Ronald R [Albuquerque, NM

2012-02-28

A deflate decompressor includes at least one decompressor unit, a memory access controller, a feedback path, and an output buffer unit. The memory access controller is coupled to the decompressor unit via a data path and includes a data buffer to receive the data stream and temporarily buffer a first portion the data stream. The memory access controller transfers fixed length data units of the data stream from the data buffer to the decompressor unit with reference to a memory pointer pointing into the memory buffer. The feedback path couples the decompressor unit to the memory access controller to feed back decrement values to the memory access controller for updating the memory pointer. The decrement values each indicate a number of bits unused by the decompressor unit when decoding the fixed length data units. The output buffer unit buffers a second portion of the data stream after decompression.

Using the UKROC dataset to make the case for resources to improve cost-efficiency in neurological rehabilitation

PubMed Central

2012-01-01

Purpose A key challenge for providers and commissioners of rehabilitation services is to find optimal balance between service costs and outcomes. This article presents a “real-lifeâ application of the UK Rehabilitation Outcomes Collaborative (UKROC) dataset. We undertook a comparative cohort analysis of case-episode data (n = 173) from two specialist neurological rehabilitation units (A and B), to compare the cost-efficiency of two service models. Key messages (i) Demographics, casemix and levels of functional dependency on admission and discharge were broadly similar for the two units. (ii) The mean length of stay for Unit A was 1.5 times longer than Unit B, which had 85% higher levels of therapy staffing in relation to occupied bed days so despite higher bed-day costs, Unit B was 20% more cost-efficient overall, for similar gain. (iii) Following analysis, engagement with service commissioners led to successful negotiation of a business plan for service reconfiguration with increased staffing levels for Unit A and further development of local community rehabilitation services. Conclusion (i) Lower front-end service costs do not always signify optimal cost-efficiency. (ii) Analysis of routinely collected clinical data can be used to engage commissioners and to make the case for resources to maximise efficiency and improve patient care. PMID:22506504

Using the UKROC dataset to make the case for resources to improve cost-efficiency in neurological rehabilitation.

PubMed

Turner-Stokes, Lynne; Poppleton, Rob; Williams, Heather; Schoewenaars, Katie; Badwan, Derar

2012-01-01

A key challenge for providers and commissioners of rehabilitation services is to find optimal balance between service costs and outcomes. This article presents a "real-life" application of the UK Rehabilitation Outcomes Collaborative (UKROC) dataset. We undertook a comparative cohort analysis of case-episode data (n = 173) from two specialist neurological rehabilitation units (A and B), to compare the cost-efficiency of two service models. (i) Demographics, casemix and levels of functional dependency on admission and discharge were broadly similar for the two units. (ii) The mean length of stay for Unit A was 1.5 times longer than Unit B, which had 85% higher levels of therapy staffing in relation to occupied bed days so despite higher bed-day costs, Unit B was 20% more cost-efficient overall, for similar gain. (iii) Following analysis, engagement with service commissioners led to successful negotiation of a business plan for service reconfiguration with increased staffing levels for Unit A and further development of local community rehabilitation services. (i) Lower front-end service costs do not always signify optimal cost-efficiency. (ii) Analysis of routinely collected clinical data can be used to engage commissioners and to make the case for resources to maximise efficiency and improve patient care.

Fluence-dependent singlet exciton dynamics in length-sorted chirality-enriched single-walled carbon nanotubes.

PubMed

Park, Jaehong; Deria, Pravas; Olivier, Jean-Hubert; Therien, Michael J

2014-02-12

We utilize individualized, length-sorted (6,5)-chirality enriched single-walled carbon nanotubes (SWNTs) having dimensions of 200 and 800 nm, femtosecond transient absorption spectroscopy, and variable excitation fluences that modulate the exciton density per nanotube unit length, to interrogate nanotube exciton/biexciton dynamics. For pump fluences below 30 μJ/cm(2), transient absorption (TA) spectra of (6,5) SWNTs reveal the instantaneous emergence of the exciton to biexciton transition (E11 → E11,BX) at 1100 nm; in contrast, under excitation fluences exceeding 100 μJ/cm(2), this TA signal manifests a rise time (τ rise ∼ 250 fs), indicating that E11 state repopulation is required to produce this signal. Femtosecond transient absorption spectroscopic data acquired over the 900-1400 nm spectral region of the near-infrared (NIR) region for (6,5) SWNTs, as a function of nanotube length and exciton density, reveal that over time delays that exceed 200 fs exciton-exciton interactions do not occur over spatial domains larger than 200 nm. Furthermore, the excitation fluence dependence of the E11 → E11,BX transient absorption signal demonstrates that relaxation of the E11 biexciton state (E11,BX) gives rise to a substantial E11 state population, as increasing delay times result in a concomitant increase of E11 → E11,BX transition oscillator strength. Numerical simulations based on a three-state model are consistent with a mechanism whereby biexcitons are generated at high excitation fluences via sequential SWNT ground- and E11-state excitation that occurs within the 980 nm excitation pulse duration. These studies that investigate fluence-dependent TA spectral evolution show that SWNT ground → E11 and E11 → E11,BX excitations are coresonant and provide evidence that E11,BX → E11 relaxation constitutes a significant decay channel for the SWNT biexciton state over delay times that exceed 200 fs, a finding that runs counter to assumptions made in previous analyses of SWNT biexciton dynamical data where exciton-exciton annihilation has been assumed to play a dominant role.

Role of medium heterogeneity and viscosity contrast in miscible flow regimes and mixing zone growth: A computational pore-scale approach

NASA Astrophysics Data System (ADS)

Afshari, Saied; Hejazi, S. Hossein; Kantzas, Apostolos

2018-05-01

Miscible displacement of fluids in porous media is often characterized by the scaling of the mixing zone length with displacement time. Depending on the viscosity contrast of fluids, the scaling law varies between the square root relationship, a sign for dispersive transport regime during stable displacement, and the linear relationship, which represents the viscous fingering regime during an unstable displacement. The presence of heterogeneities in a porous medium significantly affects the scaling behavior of the mixing length as it interacts with the viscosity contrast to control the mixing of fluids in the pore space. In this study, the dynamics of the flow and transport during both unit and adverse viscosity ratio miscible displacements are investigated in heterogeneous packings of circular grains using pore-scale numerical simulations. The pore-scale heterogeneity level is characterized by the variations of the grain diameter and velocity field. The growth of mixing length is employed to identify the nature of the miscible transport regime at different viscosity ratios and heterogeneity levels. It is shown that as the viscosity ratio increases to higher adverse values, the scaling law of mixing length gradually shifts from dispersive to fingering nature up to a certain viscosity ratio and remains almost the same afterwards. In heterogeneous media, the mixing length scaling law is observed to be generally governed by the variations of the velocity field rather than the grain size. Furthermore, the normalization of mixing length temporal plots with respect to the governing parameters of viscosity ratio, heterogeneity, medium length, and medium aspect ratio is performed. The results indicate that mixing length scales exponentially with log-viscosity ratio and grain size standard deviation while the impact of aspect ratio is insignificant. For stable flows, mixing length scales with the square root of medium length, whereas it changes linearly with length during unstable flows. This scaling procedure allows us to describe the temporal variation of mixing length using a generalized curve for various combinations of the flow conditions and porous medium properties.

Influence of nanotube length and density on the plasmonic terahertz response of single-walled carbon nanotubes

NASA Astrophysics Data System (ADS)

Karlsen, P.; Shuba, M. V.; Beckerleg, C.; Yuko, D. I.; Kuzhir, P. P.; Maksimenko, S. A.; Ksenevich, V.; Viet, Ho; Nasibulin, A. G.; Tenne, R.; Hendry, E.

2018-01-01

We measure the conductivity spectra of thin films comprising bundled single-walled carbon nanotubes (CNTs) of different average lengths in the frequency range 0.3-1000 THz and temperature interval 10-530 K. The observed temperature-induced changes in the terahertz conductivity spectra are shown to depend strongly on the average CNT length, with a conductivity around 1 THz that increases/decreases as the temperature increases for short/long tubes. This behaviour originates from the temperature dependence of the electron scattering rate, which we obtain from Drude fits of the measured conductivity in the range 0.3-2 THz for 10 μm length CNTs. This increasing scattering rate with temperature results in a subsequent broadening of the observed THz conductivity peak at higher temperatures and a shift to lower frequencies for increasing CNT length. Finally, we show that the change in conductivity with temperature depends not only on tube length, but also varies with tube density. We record the effective conductivities of composite films comprising mixtures of WS2 nanotubes and CNTs versus CNT density for frequencies in the range 0.3-1 THz, finding that the conductivity increases/decreases for low/high density films as the temperature increases. This effect arises due to the density dependence of the effective length of conducting pathways in the composite films, which again leads to a shift and temperature dependent broadening of the THz conductivity peak.

Electron elevator: Excitations across the band gap via a dynamical gap state

DOE PAGES

Lim, Anthony; Foulkes, W. M. C.; Horsfield, A. P.; ...

2016-01-27

We use time-dependent density functional theory to study self-irradiated Si. We calculate the electronic stopping power of Si in Si by evaluating the energy transferred to the electrons per unit path length by an ion of kinetic energy from 1 eV to 100 keV moving through the host. Electronic stopping is found to be significant below the threshold velocity normally identified with transitions across the band gap. A structured crossover at low velocity exists in place of a hard threshold. Lastly, an analysis of the time dependence of the transition rates using coupled linear rate equations enables one of themore » excitation mechanisms to be clearly identified: a defect state induced in the gap by the moving ion acts like an elevator and carries electrons across the band gap.« less

Plasmonic nanoshell functionalized etched fiber Bragg gratings for highly sensitive refractive index measurements.

PubMed

Burgmeier, Jörg; Feizpour, Amin; Schade, Wolfgang; Reinhard, Björn M

2015-02-15

A novel fiber optical refractive index sensor based on gold nanoshells immobilized on the surface of an etched single-mode fiber including a Bragg grating is demonstrated. The nanoparticle coating induces refractive index dependent waveguide losses, because of the variation of the evanescently guided part of the light. Hence the amplitude of the Bragg reflection is highly sensitive to refractive index changes of the surrounding medium. The nanoshell functionalized fiber optical refractive index sensor works in reflectance mode, is suitable for chemical and biochemical sensing, and shows an intensity dependency of 4400% per refractive index unit in the refractive index range between 1.333 and 1.346. Furthermore, the physical length of the sensor is smaller than 3 mm with a diameter of 6 μm, and therefore offers the possibility of a localized refractive index measurement.

Electron Elevator: Excitations across the Band Gap via a Dynamical Gap State.

PubMed

Lim, A; Foulkes, W M C; Horsfield, A P; Mason, D R; Schleife, A; Draeger, E W; Correa, A A

2016-01-29

We use time-dependent density functional theory to study self-irradiated Si. We calculate the electronic stopping power of Si in Si by evaluating the energy transferred to the electrons per unit path length by an ion of kinetic energy from 1 eV to 100 keV moving through the host. Electronic stopping is found to be significant below the threshold velocity normally identified with transitions across the band gap. A structured crossover at low velocity exists in place of a hard threshold. An analysis of the time dependence of the transition rates using coupled linear rate equations enables one of the excitation mechanisms to be clearly identified: a defect state induced in the gap by the moving ion acts like an elevator and carries electrons across the band gap.

Utterance rate and linguistic properties as determinants of lexical dysfluencies in children who stutter

PubMed Central

Howell, Peter; Au-Yeung, James; Pilgrim, Lesley

2007-01-01

Two important determinants of variation in stuttering frequency are utterance rate and the linguistic properties of the words being spoken. Little is known how these determinants interrelate. It is hypothesized that those linguistic factors that lead to change in word duration, alter utterance rate locally within an utterance that then gives rise to an increase in stuttering frequency. According to the hypothesis, utterance rate variation should occur locally within the linguistic segments in an utterance that is known to increase the likelihood of stuttering. The hypothesis is tested using length of tone unit as the linguistic factor. Three predictions are confirmed: Utterance rate varies locally within the tone units and this local variation affects stuttering frequency; stuttering frequency is positively related to the length of tone units; variations in utterance rate are correlated with tone unit length. Alternative theoretical formulations of these findings are considered. PMID:9921672

Hospitalization for congestive heart failure: is it still a cardiology business?

PubMed

Grigioni, Francesco; Carinci, Valeria; Favero, Luca; Bacchi Reggiani, Letizia; Magnani, Gaia; Potena, Luciano; Barbieri, Alessandra; Magelli, Carlo; Branzi, Angelo; Magnani, Bruno

2002-01-01

Hospital management of CHF and predictors of hospital mortality remain unclear. To address these issues, we analyzed the hospital admissions for CHF during 1996 in a large university hospital. Patients discharged with the principal diagnosis of CHF were considered eligible for the study. Among the 1511 patients (3% of all discharges) who satisfied the inclusion criteria, 75% were treated in general medicine departments (GMD) and 22% in cardiology units (CU). Patients admitted to GMD were older than those treated in CU (79+/-10 vs. 68+/-15 years, P<0.001), included a higher proportion of females (56% vs. 37%, P<0.001), and presented a higher rate of hospital mortality (13% vs. 4%, P<0.001). The overall mean length of stay was 11+/-9 days. At multivariate analysis, length of stay was not associated with the department (i.e. GMD/CU) (P=0.273). CHF is a common lethal condition often requiring treatment in GMD. Length of stay appears to depend more on patients' characteristics than on differences in practice between GMD and CU. Patients admitted to GMD present higher rates of comorbidity and hospital mortality. Strategies are urgently needed to improve hospital management of CHF.

Generalized extended Navier-Stokes theory: multiscale spin relaxation in molecular fluids.

PubMed

Hansen, J S

2013-09-01

This paper studies the relaxation of the molecular spin angular velocity in the framework of generalized extended Navier-Stokes theory. Using molecular dynamics simulations, it is shown that for uncharged diatomic molecules the relaxation time decreases with increasing molecular moment of inertia per unit mass. In the regime of large moment of inertia the fast relaxation is wave-vector independent and dominated by the coupling between spin and the fluid streaming velocity, whereas for small inertia the relaxation is slow and spin diffusion plays a significant role. The fast wave-vector-independent relaxation is also observed for highly packed systems. The transverse and longitudinal spin modes have, to a good approximation, identical relaxation, indicating that the longitudinal and transverse spin viscosities have same value. The relaxation is also shown to be isomorphic invariant. Finally, the effect of the coupling in the zero frequency and wave-vector limit is quantified by a characteristic length scale; if the system dimension is comparable to this length the coupling must be included into the fluid dynamical description. It is found that the length scale is independent of moment of inertia but dependent on the state point.

Crown development in a pioneer tree, Rhus trichocarpa, in relation to the structure and growth of individual branches.

PubMed

Osada, Noriyuki

2006-01-01

Based on an allometric reconstruction, the structure and biomass-allocation patterns of branches and current-year shoots were investigated in branches of various heights in the pioneer tree Rhus trichocarpa, to evaluate how crown development is achieved and limited in association with height. Path analysis was conducted to explore the effects of light availability, basal height and size of individual branches on branch structure and growth. Branch angle was affected by basal height, whereas branch mass was influenced primarily by light availability. This result suggests that branch structure is strongly constrained by basal height, and that trees mediate such constraints under different light environments. Previous-year leaf area and light availability showed positive effects on current-year stem mass. In contrast, branch basal height and mass negatively affected current-year stem mass. Moreover, the length of stems of a given diameter decreased with increasing branch height. Therefore the cost of biomass investment for a unit growth in length is greater for branches of larger size and at upper positions. Vertical growth rate in length decreased with increasing height. Height-dependent changes in stem allometry and angle influenced the reduction in vertical growth rate to a similar degree.

Microphase separation of comb copolymers with two different lengths of side chains

NASA Astrophysics Data System (ADS)

Aliev, M. A.; Kuzminyh, N. Yu.

2009-10-01

The phase behavior of the monodisperse AB comb copolymer melt contained the macromolecules of special architecture is discussed. Each macromolecule is assumed to be composed of two comb blocks which differ in numbers of side chains and numbers of monomer units in these chains. It is shown (by analysis of the structure factor of the melt) that microphase separation at two different length scales in the melt is possible. The large and small length scales correspond to separation between comb blocks and separation between monomer units in repeating fragments of blocks, respectively. The classification diagrams indicated which length scale is favored for a given parameters of chemical structure of macromolecules are constructed.

Effects of Ionic Dependence of DNA Persistence Length on the DNA Condensation at Room Temperature

NASA Astrophysics Data System (ADS)

Mao, Wei; Liu, Yan-Hui; Hu, Lin; Xu, Hou-Qiang

2016-05-01

DNA persistence length is a key parameter for quantitative interpretation of the conformational properties of DNA and related to the bending rigidity of DNA. A series of experiments pointed out that, in the DNA condensation process by multivalent cations, the condensed DNA takes elongated coil or compact globule states and the population of the compact globule states increases with an increase in ionic concentration. At the same time, single molecule experiments carried out in solution with multivalent cations (such as spermidine, spermine) indicated that DNA persistence length strongly depends on the ionic concentration. In order to revolve the effects of ionic concentration dependence of persistence length on DNA condensation, a model including the ionic concentration dependence of persistence length and strong correlation of multivalent cation on DNA is provided. The autocorrelation function of the tangent vectors is found as an effective way to detect the ionic concentration dependence of toroidal conformations. With an increase in ion concentration, the first periodic oscillation contained in the autocorrelation function shifts, the number of segment contained in the first periodic oscillation decreases gradually. According to the experiments, the average long-axis length is defined to estimate the ionic concentration dependence of condensation process further. The relation between long-axis length and ionic concentration matches the experimental results qualitatively. Supported by National Natural Science Foundation of China under Grant Nos. 11047022, 11204045, 11464004 and 31360215; The Research Foundation from Ministry of Education of China (212152), Guizhou Provincial Tracking Key Program of Social Development (SY20123089, SZ20113069); The General Financial Grant from the China Postdoctoral Science Foundation (2014M562341); The Research Foundation for Young University Teachers from Guizhou University (201311); The West Light Foundation (2015) and College Innovation Talent Team of Guizhou Province, (2014) 32

A computational algorithm addressing how vessel length might depend on vessel diameter

Treesearch

Jing Cai; Shuoxin Zhang; Melvin T. Tyree

2010-01-01

The objective of this method paper was to examine a computational algorithm that may reveal how vessel length might depend on vessel diameter within any given stem or species. The computational method requires the assumption that vessels remain approximately constant in diameter over their entire length. When this method is applied to three species or hybrids in the...

Unified description of the slip phenomena in sheared polymer films: A molecular dynamics study

NASA Astrophysics Data System (ADS)

Priezjev, Nikolai

2010-03-01

The dynamic behavior of the slip length in shear flow of polymer melts past atomically smooth surfaces is investigated using MD simulations. The polymer melt was modeled as a collection of FENE-LJ bead-spring chains. We consider shear flow conditions at low pressures and weak wall-fluid interaction energy so that fluid velocity profiles are linear throughout the channel at all shear rates examined. In agreement with earlier studies we confirm that for shear- thinning fluids the slip length passes through a local minimum at low shear rates and then increases rapidly at higher shear rates. We found that the rate dependence of the slip length depends on the lattice orientation at high shear rates. The MD results show that the ratio of slip length to viscosity follows a master curve when plotted as a function of a single variable that depends on the structure factor, contact density and temperature of the first fluid layer near the solid wall. The universal dependence of the slip length holds for a number of parameters of the interface: fluid density and structure (chain length), wall-fluid interaction energy, wall density, lattice orientation, thermal or solid walls.

On the Impact of Widening Vector Registers on Sequence Alignment

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

Daily, Jeffrey A.; Kalyanaraman, Anantharaman; Krishnamoorthy, Sriram

2016-09-22

Vector extensions, such as SSE, have been part of the x86 since the 1990s, with applications in graphics, signal processing, and scientific applications. Although many algorithms and applications can naturally benefit from automatic vectorization techniques, there are still many that are difficult to vectorize due to their dependence on irregular data structures, dense branch operations, or data dependencies. Sequence alignment, one of the most widely used operations in bioinformatics workflows, has a computational footprint that features complex data dependencies. In this paper, we demonstrate that the trend of widening vector registers adversely affects the state-of-the-art sequence alignment algorithm based onmore » striped data layouts. We present a practically efficient SIMD implementation of a parallel scan based sequence alignment algorithm that can better exploit wider SIMD units. We conduct comprehensive workload and use case analyses to characterize the relative behavior of the striped and scan approaches and identify the best choice of algorithm based on input length and SIMD width.« less

Equivalent chain lengths of all C4-C23 saturated monomethyl branched fatty acid methyl esters on methylsilicone OV-1 stationary phase.

PubMed

Kubinec, Róbert; Blaško, Jaroslav; Górová, Renáta; Addová, Gabriela; Ostrovský, Ivan; Amann, Anton; Soják, Ladislav

2011-04-01

Isomer mixtures of monomethyl branched saturated C7-C23 fatty acid methyl esters (FAME) were prepared by performing a methylene insertion reaction to the straight chain FAME and this study model was completed by using commercially available standards of C4-C7 FAME. The equivalent chain lengths (ECL) of all 220 C4-C23 monomethyl branched FAME on OV-1 stationary phase were measured, achieving an average repeatability of ±0.0004 ECL units. The monomethyl branched FAME was identified by GC on the basis of regularity of the fractional chain lengths (FCL) dependence on the number of carbon atoms (C(z)) of individual homologous series of methyl 2-, 3-, …, 21-FAME. The prediction of retention of the first homologues, having the new position of methyl group beginning at higher carbon atoms number, and analogously for the second, third, fourth, and other members of the homologous series, allowed the dependence FCL=f(C(z)) for the first and subsequent members of beginning homologous of monomethyl derivatives of FAME. The identification was confirmed by mass spectrometry. All of the methyl isomers of FAME, which could not be completely separated by gas chromatography due to having a methyl group in surroundings of the middle of the carbon chain, were resolved by mass spectrometry using deconvolution in a SIM-mode. Measured gas chromatographic and mass spectrometric data were applied for identification of the monomethyl branched saturated FAME in tongue coating. Copyright © 2011 Elsevier B.V. All rights reserved.

Multiscale Multiphysics Caprock Seal Analysis: A Case Study of the Farnsworth Unit, Texas, USA

NASA Astrophysics Data System (ADS)

Heath, J. E.; Dewers, T. A.; Mozley, P.

2015-12-01

Caprock sealing behavior depends on coupled processes that operate over a variety of length and time scales. Capillary sealing behavior depends on nanoscale pore throats and interfacial fluid properties. Larger-scale sedimentary architecture, fractures, and faults may govern properties of potential "seal-bypass" systems. We present the multiscale multiphysics investigation of sealing integrity of the caprock system that overlies the Morrow Sandstone reservoir, Farnsworth Unit, Texas. The Morrow Sandstone is the target injection unit for an on-going combined enhanced oil recovery-CO2 storage project by the Southwest Regional Partnership on Carbon Sequestration (SWP). Methods include small-to-large scale measurement techniques, including: focused ion beam-scanning electron microscopy; laser scanning confocal microscopy; electron and optical petrography; core examinations of sedimentary architecture and fractures; geomechanical testing; and a noble gas profile through sealing lithologies into the reservoir, as preserved from fresh core. The combined data set is used as part of a performance assessment methodology. The authors gratefully acknowledge the U.S. Department of Energy's (DOE) National Energy Technology Laboratory for sponsoring this project through the SWP under Award No. DE-FC26-05NT42591. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Addiction and suicidal behavior in acute psychiatric inpatients.

PubMed

Ries, Richard K; Yuodelis-Flores, Christine; Roy-Byrne, Peter P; Nilssen, Odd; Russo, Joan

2009-01-01

This study aims to evaluate the relationship of alcohol/drug use and effect severities to the degree of suicidality in acutely admitted psychiatric patients. Both degree of substance dependency and degree of substance-induced syndrome were analyzed. In addition, length of stay, involuntary status, and against medical advice discharge status were determined as they related to these variables. Structured clinical admissions and discharge ratings were gathered from 10,667 consecutive, single-case individual records, from an urban acute care county psychiatric hospital. Data indicate that of the most severely suicidal group, 56% had substance abuse or dependence, 40% were rated as having half or more of their admission syndrome substance induced, and most had nonpsychotic diagnoses. There was an inverse relationship between degree of substance problem and length of stay. Although these patients more commonly left against medical advice, and were readmitted more frequently, they were less likely to be involuntarily committed. A large, potentially lethal, and highly expensive subgroup of patients has been characterized, which might be called the "New Revolving Door acute psychiatric inpatient." This group, which uses the most expensive level of care in the mental health system but is substantially addiction related, poses special challenges for inpatient psychiatric units, addiction treatment providers, and health care planners.

Thick filament length and isoform composition determine self-organized contractile units in actomyosin bundles.

PubMed

Thoresen, Todd; Lenz, Martin; Gardel, Margaret L

2013-02-05

Diverse myosin II isoforms regulate contractility of actomyosin bundles in disparate physiological processes by variations in both motor mechanochemistry and the extent to which motors are clustered into thick filaments. Although the role of mechanochemistry is well appreciated, the extent to which thick filament length regulates actomyosin contractility is unknown. Here, we study the contractility of minimal actomyosin bundles formed in vitro by mixtures of F-actin and thick filaments of nonmuscle, smooth, and skeletal muscle myosin isoforms with varied length. Diverse myosin II isoforms guide the self-organization of distinct contractile units within in vitro bundles with shortening rates similar to those of in vivo myofibrils and stress fibers. The tendency to form contractile units increases with the thick filament length, resulting in a bundle shortening rate proportional to the length of constituent myosin thick filament. We develop a model that describes our data, providing a framework in which to understand how diverse myosin II isoforms regulate the contractile behaviors of disordered actomyosin bundles found in muscle and nonmuscle cells. These experiments provide insight into physiological processes that use dynamic regulation of thick filament length, such as smooth muscle contraction. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Observation of thermodynamic phase noise using a slow-light resonance in a fiber Bragg grating

NASA Astrophysics Data System (ADS)

Skolianos, George; Arora, Arushi; Bernier, Martin; Digonnet, Michel

2017-02-01

Thermodynamic phase noise in passive fiber devices is generally so weak that in most devices, in particular fiber sensors, it has only been observed in fiber lengths in the range of 1 meter or much longer. Here we present a passive fiber strain sensor only 4.5 mm in length in which the noise in the frequency range of 1 kHz to 12 kHz is limited by thermal phase noise in the fiber. The phase noise could be measured in such a short fiber by utilizing a slow-light fiber Bragg grating (FBG) resonator in which the phase noise is magnified by the resonator's slowing-down factor ng/n ≈ 370, where ng is the group index. At the same time, the usually dominant laser frequency noise was brought below the level of the phase noise by using a short fiber and a low-noise laser with a linewidth under 200 Hz. At 4 kHz, the total measured noise expressed in units of strain is 110 fɛ/√Hz, and the phase noise accounts for 77% of it. This sensor resolves a single-pass thermodynamic length fluctuation of only 5 x10-16 m/√Hz. These measurements provide experimental support for the dependencies of the phase noise on the fiber resonator length and group index predicted by a recent model.

Length-dependent modulation of cytoskeletal remodeling and mechanical energetics in airway smooth muscle.

PubMed

Kim, Hak Rim; Liu, Katrina; Roberts, Thomas J; Hai, Chi-Ming

2011-06-01

Actin cytoskeletal remodeling is an important mechanism of airway smooth muscle (ASM) contraction. We tested the hypothesis that mechanical strain modulates the cholinergic receptor-mediated cytoskeletal recruitment of actin-binding and integrin-binding proteins in intact airway smooth muscle, thereby regulating the mechanical energetics of airway smooth muscle. We found that the carbachol-stimulated cytoskeletal recruitment of actin-related protein-3 (Arp3), metavinculin, and talin were up-regulated at short muscle lengths and down-regulated at long muscle lengths, suggesting that the actin cytoskeleton--integrin complex becomes enriched in cross-linked and branched actin filaments in shortened ASM. The mechanical energy output/input ratio during sinusoidal length oscillation was dependent on muscle length, oscillatory amplitude, and cholinergic activation. The enhancing effect of cholinergic stimulation on mechanical energy output/input ratio at short and long muscle lengths may be explained by the length-dependent modulation of cytoskeletal recruitment and crossbridge cycling, respectively. We postulate that ASM functions as a hybrid biomaterial, capable of switching between operating as a cytoskeleton-based mechanical energy store at short muscle lengths to operating as an actomyosin-powered mechanical energy generator at long muscle lengths. This postulate predicts that targeting the signaling molecules involved in cytoskeletal recruitment may provide a novel approach to dilating collapsed airways in obstructive airway disease.

Length and sequence heterogeneity in 5S rDNA of Populus deltoides.

PubMed

Negi, Madan S; Rajagopal, Jyothi; Chauhan, Neeti; Cronn, Richard; Lakshmikumaran, Malathi

2002-12-01

The 5S rRNA genes and their associated non-transcribed spacer (NTS) regions are present as repeat units arranged in tandem arrays in plant genomes. Length heterogeneity in 5S rDNA repeats was previously identified in Populus deltoides and was also observed in the present study. Primers were designed to amplify the 5S rDNA NTS variants from the P. deltoides genome. The PCR-amplified products from the two accessions of P. deltoides (G3 and G48) suggested the presence of length heterogeneity of 5S rDNA units within and among accessions, and the size of the spacers ranged from 385 to 434 bp. Sequence analysis of the non-transcribed spacer (NTS) revealed two distinct classes of 5S rDNA within both accessions: class 1, which contained GAA trinucleotide microsatellite repeats, and class 2, which lacked the repeats. The class 1 spacer shows length variation owing to the microsatellite, with two clones exhibiting 10 GAA repeat units and one clone exhibiting 16 such repeat units. However, distance analysis shows that class 1 spacer sequences are highly similar inter se, yielding nucleotide diversity (pi) estimates that are less than 0.15% of those obtained for class 2 spacers (pi = 0.0183 vs. 0.1433, respectively). The presence of microsatellite in the NTS region leading to variation in spacer length is reported and discussed for the first time in P. deltoides.

Computational procedure of optimal inventory model involving controllable backorder rate and variable lead time with defective units

NASA Astrophysics Data System (ADS)

Lee, Wen-Chuan; Wu, Jong-Wuu; Tsou, Hsin-Hui; Lei, Chia-Ling

2012-10-01

This article considers that the number of defective units in an arrival order is a binominal random variable. We derive a modified mixture inventory model with backorders and lost sales, in which the order quantity and lead time are decision variables. In our studies, we also assume that the backorder rate is dependent on the length of lead time through the amount of shortages and let the backorder rate be a control variable. In addition, we assume that the lead time demand follows a mixture of normal distributions, and then relax the assumption about the form of the mixture of distribution functions of the lead time demand and apply the minimax distribution free procedure to solve the problem. Furthermore, we develop an algorithm procedure to obtain the optimal ordering strategy for each case. Finally, three numerical examples are also given to illustrate the results.

Data collection as the first step in program development: the experience of a chronic care palliative unit.

PubMed

Munn, B; Worobec, F

1997-01-01

This retrospective descriptive study of 73 patients who died in St. Peter's Hospital examines and contrasts the patients profile and referral sources of a palliative care unit in a chronic care hospital over two six-month periods during 1994 and 1995. Shortened length of stay (83.8 and 43.2 days respectively), documentation issues, CPR practices (CPR was desired by seven patients up to the time of death), and lack of referrals from long-term care facilities have led St. Peter's Hospital to ask further questions of its palliative care program, e.g. given the lack of referrals from long-term care facilities, how is palliative care being managed in this sector? In Ontario, palliative care has been placed under the domain of chronic care and program development depends in part on the knowledge of the population it serves. This study is a first step.

Differential effect of birthplace and length of residence on body mass index (BMI) by education, gender and race/ethnicity.

PubMed

Sanchez-Vaznaugh, Emma V; Kawachi, Ichiro; Subramanian, S V; Sánchez, Brisa N; Acevedo-Garcia, Dolores

2008-10-01

Although birthplace and length of residence have been found to be associated with Body Mass Index (BMI)/obesity in the USA, their effects may not be the same across groups defined by education, gender and race/ethnicity. Using cross-sectional population based data from the 2001 California Health Interview Survey, we investigated the associations of birthplace and US length of residence with BMI, and whether the influence of birthplace-US length of residence on BMI varied by education, gender and race/ethnicity. Our sample included 37,350 adults aged 25-64 years. Self-reported weight and height were used to calculate BMI. Birthplace and length of residence were combined into a single variable divided into five levels: US-born, foreign-born living in the United States for more than 15, 10-14, 5-9, and less than 5 years. Controlling for age, gender, marital status, race/ethnicity, education, income, fruit and vegetable consumption, current smoking and alcohol use, we found that: (1) foreign-born adults had lower BMI than US-born adults; (2) among foreign-born adults, longer residence in the United States was associated with higher BMI; and (3) the effect of birthplace-length of US residence on BMI differed by education level, gender and race/ethnicity. Specifically, longer residence in the United States was associated with the greatest percent increases in BMI among the lowest educated groups than higher educated groups, among women (vs. men) and among Hispanics (vs. other racial/ethnic groups). These findings suggest that a protective effect of foreign birthplace on BMI appears to attenuate with length of residence in the United States, and also reveal that BMI/obesity trajectories associated with length of US residence vary by education, gender and race/ethnicity. Immigrant status, independently and in combination with education, gender and race/ethnicity should be considered in future obesity prevention and reduction efforts.

The Snakelike Chain Character of Unstructured RNA

PubMed Central

Jacobson, David R.; McIntosh, Dustin B.; Saleh, Omar A.

2013-01-01

In the absence of base-pairing and tertiary structure, ribonucleic acid (RNA) assumes a random-walk conformation, modulated by the electrostatic self-repulsion of the charged, flexible backbone. This behavior is often modeled as a Kratky-Porod “wormlike chain” (WLC) with a Barrat-Joanny scale-dependent persistence length. In this study we report measurements of the end-to-end extension of poly(U) RNA under 0.1 to 10 pN applied force and observe two distinct elastic-response regimes: a low-force, power-law regime characteristic of a chain of swollen blobs on long length scales and a high-force, salt-valence-dependent regime consistent with ion-stabilized crumpling on short length scales. This short-scale structure is additionally supported by force- and salt-dependent quantification of the RNA ion atmosphere composition, which shows that ions are liberated under stretching; the number of ions liberated increases with increasing bulk salt concentration. Both this result and the observation of two elastic-response regimes directly contradict the WLC model, which predicts a single elastic regime across all forces and, when accounting for scale-dependent persistence length, the opposite trend in ion release with salt concentration. We conclude that RNA is better described as a “snakelike chain,” characterized by smooth bending on long length scales and ion-stabilized crumpling on short length scales. In monovalent salt, these two regimes are separated by a characteristic length that scales with the Debye screening length, highlighting the determining importance of electrostatics in RNA conformation. PMID:24314087

Electrowetting-driven variable-focus microlens on flexible surfaces.

PubMed

Li, Chenhui; Jiang, Hongrui

2012-06-04

We demonstrate a flexible, electrowetting-driven, variable-focus liquid microlens. The microlens is fabricated using a soft polymer polydimethylsiloxane. The lens can be smoothly wrapped onto a curved surface. A low-temperature fabrication process was developed to reduce the stress on and to avoid any damage to the polymer. The focal length of the microlens varies between -15.0 mm to +28.0 mm, depending on the applied voltage. The resolving power of the microlens is 25.39 line pairs per mm using a 1951 United States Air Force resolution chart. The typical response time of the lens is around 50 ms.

Electrowetting-driven variable-focus microlens on flexible surfaces

PubMed Central

Li, Chenhui; Jiang, Hongrui

2012-01-01

We demonstrate a flexible, electrowetting-driven, variable-focus liquid microlens. The microlens is fabricated using a soft polymer polydimethylsiloxane. The lens can be smoothly wrapped onto a curved surface. A low-temperature fabrication process was developed to reduce the stress on and to avoid any damage to the polymer. The focal length of the microlens varies between −15.0 mm to +28.0 mm, depending on the applied voltage. The resolving power of the microlens is 25.39 line pairs per mm using a 1951 United States Air Force resolution chart. The typical response time of the lens is around 50 ms. PMID:22904571

Stochastic treatment of electron multiplication without scattering in dielectrics

NASA Technical Reports Server (NTRS)

Lin, D. L.; Beers, B. L.

1981-01-01

By treating the emission of optical phonons as a Markov process, a simple analytic method is developed for calculating the electronic ionization rate per unit length for dielectrics. The effects of scattering from acoustic and optical phonons are neglected. The treatment obtains universal functions in recursive form, the theory depending on only two dimensionless energy ratios. A comparison of the present work with other numerical approaches indicates that the effect of scattering becomes important only when the electric potential energy drop in a mean free path for optical-phonon emission is less than about 25% of the ionization potential. A comparison with Monte Carlo results is also given for Teflon.

Finite element analysis of electromagnetic propagation in an absorbing wave guide

NASA Technical Reports Server (NTRS)

Baumeister, Kenneth J.

1986-01-01

Wave guides play a significant role in microwave space communication systems. The attenuation per unit length of the guide depends on its construction and design frequency range. A finite element Galerkin formulation has been developed to study TM electromagnetic propagation in complex two-dimensional absorbing wave guides. The analysis models the electromagnetic absorptive characteristics of a general wave guide which could be used to determine wall losses or simulate resistive terminations fitted into the ends of a guide. It is believed that the general conclusions drawn by using this simpler two-dimensional geometry will be fundamentally the same for other geometries.

76 FR 8772 - Cut-to-Length Carbon Steel Plate From India, Indonesia, Italy, Japan and Korea

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-15

... Review)] Cut-to-Length Carbon Steel Plate From India, Indonesia, Italy, Japan and Korea AGENCY: United...-year reviews concerning the countervailing duty orders on cut-to-length carbon steel plate from India, Indonesia, Italy, and Korea and the antidumping duty orders on cut-to-length carbon steel plate from India...

Analysis of bulk arrival queueing system with batch size dependent service and working vacation

NASA Astrophysics Data System (ADS)

Niranjan, S. P.; Indhira, K.; Chandrasekaran, V. M.

2018-04-01

This paper concentrates on single server bulk arrival queue system with batch size dependent service and working vacation. The server provides service in two service modes depending upon the queue length. The server provides single service if the queue length is at least `a'. On the other hand the server provides fixed batch service if the queue length is at least `k' (k > a). Batch service is provided with some fixed batch size `k'. After completion of service if the queue length is less than `a' then the server leaves for working vacation. During working vacation customers are served with lower service rate than the regular service rate. Service during working vacation also contains two service modes. For the proposed model probability generating function of the queue length at an arbitrary time will be obtained by using supplementary variable technique. Some performance measures will also be presented with suitable numerical illustrations.

Toxicological Profiling of Highly Purified Single-Walled Carbon Nanotubes with Different Lengths in the Rodent Lung and Escherichia Coli.

PubMed

Wang, Xiang; Lee, Jae-Hyeok; Li, Ruibin; Liao, Yu-Pei; Kang, Joohoon; Chang, Chong Hyun; Guiney, Linda M; Mirshafiee, Vahid; Li, Linjiang; Lu, Jianqin; Xia, Tian; Hersam, Mark C; Nel, André E

2018-06-01

Carbon nanotubes (CNTs) exhibit a number of physicochemical properties that contribute to adverse biological outcomes. However, it is difficult to define the independent contribution of individual properties without purified materials. A library of highly purified single-walled carbon nanotubes (SWCNTs) of different lengths is prepared from the same base material by density gradient ultracentrifugation, designated as short (318 nm), medium (789 nm), and long (1215 nm) SWCNTs. In vitro screening shows length-dependent interleukin-1β (IL-1β) production, in order of long > medium > short. However, there are no differences in transforming growth factor-β1 production in BEAS-2B cells. Oropharyngeal aspiration shows that all the SWCNTs induce profibrogenic effects in mouse lung at 21 d postexposure, but there are no differences between tube lengths. In contrast, these SWCNTs demonstrate length-dependent antibacterial effects on Escherichia coli, with the long SWCNT exerting stronger effects than the medium or short tubes. These effects are reduced by Pluronic F108 coating or supplementing with glucose. The data show length-dependent effects on proinflammatory response in macrophage cell line and antibacterial effects, but not on collagen deposition in the lung. These data demonstrate that over the length scale tested, the biological response to highly purified SWCNTs is dependent on the complexity of the nano/bio interface. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Entanglement entropy in a one-dimensional disordered interacting system: the role of localization.

PubMed

Berkovits, Richard

2012-04-27

The properties of the entanglement entropy (EE) in one-dimensional disordered interacting systems are studied. Anderson localization leaves a clear signature on the average EE, as it saturates on the length scale exceeding the localization length. This is verified by numerically calculating the EE for an ensemble of disordered realizations using the density matrix renormalization group method. A heuristic expression describing the dependence of the EE on the localization length, which takes into account finite-size effects, is proposed. This is used to extract the localization length as a function of the interaction strength. The localization length dependence on the interaction fits nicely with the expectations.

Self-assembly Controls Self-cleavage of HHR from ASBVd (-): a Combined SANS and Modeling Study

NASA Astrophysics Data System (ADS)

Leclerc, Fabrice; Zaccai, Giuseppe; Vergne, Jacques; Řìhovà, Martina; Martel, Anne; Maurel, Marie-Christine

2016-07-01

In the Avocado Sunblotch Viroid (ASBVd: 249-nt) from the Avsunviroidae family, a symmetric rolling-circle replication operates through an autocatalytic mechanism mediated by hammerhead ribozymes (HHR) embedded in both polarity strands. The concatenated multimeric ASBVd (+) and ASBVd (-) RNAs thus generated are processed by cleavage to unit-length where ASBVd (-) self-cleaves with more efficiency. Absolute scale small angle neutron scattering (SANS) revealed a temperature-dependent dimer association in both ASBVd (-) and its derived 79-nt HHR (-). A joint thermodynamic analysis of SANS and catalytic data indicates the rate-determining step corresponds to the dimer/monomer transition. 2D and 3D models of monomeric and dimeric HHR (-) suggest that the inter-molecular contacts stabilizing the dimer (between HI and HII domains) compete with the intra-molecular ones stabilizing the active conformation of the full-length HHR required for an efficient self-cleavage. Similar competing intra- and inter-molecular contacts are proposed in ASBVd (-) though with a remoter region from an extension of the HI domain.

Characteristics of the electrical explosion of fine metallic wires in vacuum

NASA Astrophysics Data System (ADS)

Wang, Kun; Shi, Zongqian; Shi, Yuanjie; Zhao, Zhigang

2017-09-01

The experimental investigations on the electrical explosion of aluminum, silver, tungsten and platinum wires are carried out. The dependence of the parameters related to the specific energy deposition on the primary material properties is investigated. The polyimide coatings are applied to enhance the energy deposition for the exploding wires with percent of vaporized energy less than unit. The characteristics of the exploding wires of different materials with and without insulating coatings are studied. The effect of wire length on the percent of vaporization energy for exploding coated wires is presented. A laser probe is employed to construct the shadowgraphy, schlieren and interferometry diagnostics. The optical diagnostics demonstrate the morphology of the exploding products and structure of the energy deposition. The influence of insulating coatings on different wire materials is analyzed. The expansion trajectories of the exploding wires without and with insulating coatings are estimated from the shadowgram. More specific energy is deposited into the coated wires of shorter wire length, leading to faster expanding velocity of the high-density products.

Antimicrobial resistance in Hispanic patients hospitalized in San Antonio, TX with community-acquired pneumonia.

PubMed

Restrepo, Marcos I; Velez, Maria I; Serna, Gloria; Anzueto, Antonio; Mortensen, Eric M

2010-11-01

Limited information is available on the antimicrobial resistance of patients with community-acquired pneumonia (CAP) depending on their ethnicity. Our aim was to compare the clinical characteristics, etiology, and microbiological resistance of Hispanic versus non-Hispanic white patients. A retrospective cohort of 601 patients with a diagnosis of CAP included 288 non-Hispanic whites and 313 Hispanics. Penicillin-resistant Streptococcus pneumoniae was more common among Hispanic patients (21.7% vs 0%; P=0.03) but there were no significant differences in macrolide-resistant S pneumoniae, drug-resistant S pneumoniae, or potential or actual multidrug-resistant pathogens (eg, drug-resistant S pneumoniae, methicillin-resistant Staphylococcus aureus, Pseudomonas spp., and Acinetobacter spp.). There were no differences among groups in length of hospital stay, intensive care unit (ICU) admission, or 30-day mortality. This study suggests that Hispanic patients with CAP have a higher rate of penicillin-resistant S pneumoniae, but no differences in antimicrobial resistance, 30-day mortality, ICU admission, or length of stay when compared with non-Hispanic white patients.

Crystal structure of full-length Zika virus NS5 protein reveals a conformation similar to Japanese encephalitis virus NS5

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

Upadhyay, Anup K.; Cyr, Matthew; Longenecker, Kenton

The rapid spread of the recentZika virus(ZIKV) epidemic across various countries in the American continent poses a major health hazard for the unborn fetuses of pregnant women. To date, there is no effective medical intervention. The nonstructural protein 5 ofZika virus(ZIKV-NS5) is critical for ZIKV replication through the 5'-RNA capping and RNA polymerase activities present in its N-terminal methyltransferase (MTase) and C-terminal RNA-dependent RNA polymerase (RdRp) domains, respectively. The crystal structure of the full-length ZIKV-NS5 protein has been determined at 3.05 Å resolution from a crystal belonging to space groupP2 12 12 and containing two protein molecules in the asymmetricmore » unit. The structure is similar to that reported for the NS5 protein fromJapanese encephalitis virusand suggests opportunities for structure-based drug design targeting either its MTase or RdRp domain.« less

Enhanced central venous catheter bundle for pediatric parenteral-dependent intestinal failure.

PubMed

Ormsby, Jennifer A; Bukoye, Bola; Lajoie, Debra; Shermont, Herminia; Martin, Lisa; Leger, Kierrah; Mahoney, Judy; Potter-Bynoe, Gail; Carpenter, Jane; Ozonoff, Al; Lee, Grace M

2018-05-16

Central line-associated bloodstream infections (CLABSIs) cause substantial morbidity and increase antimicrobial use and length of stay among hospitalized children in the United States. CLABSI occurs more frequently among high-risk pediatric patients, such as those with intestinal failure (IF) who are parenteral nutrition (PN) dependent. Following an increase in CLABSI rates, a quality improvement (QI) initiative was implemented. Using QI methodology, an enhanced central venous catheter (CVC) maintenance bundle was developed and implemented on 2 units for pediatric PN-dependent patients with IF. CLABSI rates were prospectively monitored pre- and postimplementation, and bundle element adherence was monitored. Enhanced bundle elements included chlorhexidine-impregnated patch, daily bathing, ethanol locks, 2 nurses for CVC care in a distraction-free zone, peripheral laboratory draws, bundling routine laboratory tests, and PN administration set changes every 24 hours. Adherence to enhanced bundle elements increased to >90% over 3 months. CLABSI rates averaged 1.41 per 1,000 central line days preimplementation compared with 0.40 per 1,000 device days postimplementation (P = .003), an 85% absolute reduction in CLABSI rates over 12 months. Patients with IF are at an increased risk for CLABSI. Enhanced CVC maintenance bundles that specifically target prevention practices in this population may be beneficial. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Band Gaps for Elastic Wave Propagation in a Periodic Composite Beam Structure Incorporating Microstructure and Surface Energy Effects

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

Zhang, G. Y.; Gao, X. -L.; Bishop, J. E.

Here, a new model for determining band gaps for elastic wave propagation in a periodic composite beam structure is developed using a non-classical Bernoulli–Euler beam model that incorporates the microstructure, surface energy and rotational inertia effects. The Bloch theorem and transfer matrix method for periodic structures are employed in the formulation. The new model reduces to the classical elasticity-based model when both the microstructure and surface energy effects are not considered. The band gaps predicted by the new model depend on the microstructure and surface elasticity of each constituent material, the unit cell size, the rotational inertia, and the volumemore » fraction. To quantitatively illustrate the effects of these factors, a parametric study is conducted. The numerical results reveal that the band gap predicted by the current non-classical model is always larger than that predicted by the classical model when the beam thickness is very small, but the difference is diminishing as the thickness becomes large. Also, it is found that the first frequency for producing the band gap and the band gap size decrease with the increase of the unit cell length according to both the current and classical models. In addition, it is observed that the effect of the rotational inertia is larger when the exciting frequency is higher and the unit cell length is smaller. Furthermore, it is seen that the volume fraction has a significant effect on the band gap size, and large band gaps can be obtained by tailoring the volume fraction and material parameters.« less

Band Gaps for Elastic Wave Propagation in a Periodic Composite Beam Structure Incorporating Microstructure and Surface Energy Effects

DOE PAGES

Zhang, G. Y.; Gao, X. -L.; Bishop, J. E.; ...

2017-11-20

Here, a new model for determining band gaps for elastic wave propagation in a periodic composite beam structure is developed using a non-classical Bernoulli–Euler beam model that incorporates the microstructure, surface energy and rotational inertia effects. The Bloch theorem and transfer matrix method for periodic structures are employed in the formulation. The new model reduces to the classical elasticity-based model when both the microstructure and surface energy effects are not considered. The band gaps predicted by the new model depend on the microstructure and surface elasticity of each constituent material, the unit cell size, the rotational inertia, and the volumemore » fraction. To quantitatively illustrate the effects of these factors, a parametric study is conducted. The numerical results reveal that the band gap predicted by the current non-classical model is always larger than that predicted by the classical model when the beam thickness is very small, but the difference is diminishing as the thickness becomes large. Also, it is found that the first frequency for producing the band gap and the band gap size decrease with the increase of the unit cell length according to both the current and classical models. In addition, it is observed that the effect of the rotational inertia is larger when the exciting frequency is higher and the unit cell length is smaller. Furthermore, it is seen that the volume fraction has a significant effect on the band gap size, and large band gaps can be obtained by tailoring the volume fraction and material parameters.« less

The use of enhanced recovery after surgery (ERAS) principles in Scottish orthopaedic units--an implementation and follow-up at 1 year, 2010-2011: a report from the Musculoskeletal Audit, Scotland.

PubMed

Scott, Nicholas B; McDonald, David; Campbell, Jane; Smith, Richard D; Carey, A Kate; Johnston, Ian G; James, Kate R; Breusch, Steffen J

2013-01-01

To establish whether a nationally guided programme can lead to more widespread implementation of enhanced recovery after surgery (ERAS), a well-established optimised care pathway for lower limb arthroplasty. In 2010, National Services Scotland's Musculoskeletal Audit was asked to perform a 'snapshot' audit of the current peri-operative management of patients undergoing total hip and knee arthroplasty in all 22 Scottish orthopaedic units with an identical follow-up audit in 2011 after input and support from the national steering group. Audit 1 and audit 2 involved 1,345 and 1,278 patients, respectively. The number of Scottish units that developed an ERAS programme increased from 8 (36 %) to 15 (68 %). Units that included more ERAS patients had earlier mobilisation rates (146/474, 36 % ERAS patients mobilised same day vs. 34/873, 4 % non-ERAS; n = 22 units, r = 0.55, p = 0.008) and shorter post-operative length of stay (median 4 days vs. ERAS, 5 days non-ERAS, n = 22 units, r = -0.64, p = 0.001). ERAS knee arthroplasty patients had lower blood transfusion rates (5/205, 2 % vs. 51/399, 13 %, n = 22 units, r = -0.62, p = 0.002). Units that restricted the use of IV fluids post-operatively had higher early mobilisation rates (n = 22 units, r = 0.48, p = 0.03) and shorter post-operative length of stay (n = 22 units, r = -0.56, p = 0.007). Reduced use of patient-controlled analgesia was also associated with earlier mobilisation (n = 22 units, r = 0.49, p = 0.02) and shorter length of stay (n = 22 units, r = -0.39, p = 0.07). Urinary catheterisation rates also dropped from 468/1,345 (35 %) in 2010 to 337/1,278 (26 %) in 2011 (n = 22 units, z = 2.19, p = 0.03). A clinically guided and nationally supported process has proven highly successful in achieving a further uptake of enhanced recovery principles after lower limb arthroplasty in Scotland, which has resulted in clinical benefits to patients and reduced length of hospital stay.

Differences in Pedaling Technique in Cycling: A Cluster Analysis.

PubMed

Lanferdini, Fábio J; Bini, Rodrigo R; Figueiredo, Pedro; Diefenthaeler, Fernando; Mota, Carlos B; Arndt, Anton; Vaz, Marco A

2016-10-01

To employ cluster analysis to assess if cyclists would opt for different strategies in terms of neuromuscular patterns when pedaling at the power output of their second ventilatory threshold (PO VT2 ) compared with cycling at their maximal power output (PO MAX ). Twenty athletes performed an incremental cycling test to determine their power output (PO MAX and PO VT2 ; first session), and pedal forces, muscle activation, muscle-tendon unit length, and vastus lateralis architecture (fascicle length, pennation angle, and muscle thickness) were recorded (second session) in PO MAX and PO VT2 . Athletes were assigned to 2 clusters based on the behavior of outcome variables at PO VT2 and PO MAX using cluster analysis. Clusters 1 (n = 14) and 2 (n = 6) showed similar power output and oxygen uptake. Cluster 1 presented larger increases in pedal force and knee power than cluster 2, without differences for the index of effectiveness. Cluster 1 presented less variation in knee angle, muscle-tendon unit length, pennation angle, and tendon length than cluster 2. However, clusters 1 and 2 showed similar muscle thickness, fascicle length, and muscle activation. When cycling at PO VT2 vs PO MAX , cyclists could opt for keeping a constant knee power and pedal-force production, associated with an increase in tendon excursion and a constant fascicle length. Increases in power output lead to greater variations in knee angle, muscle-tendon unit length, tendon length, and pennation angle of vastus lateralis for a similar knee-extensor activation and smaller pedal-force changes in cyclists from cluster 2 than in cluster 1.

An Ancient Relation between Units of Length and Volume Based on a Sphere

PubMed Central

Zapassky, Elena; Gadot, Yuval; Finkelstein, Israel; Benenson, Itzhak

2012-01-01

The modern metric system defines units of volume based on the cube. We propose that the ancient Egyptian system of measuring capacity employed a similar concept, but used the sphere instead. When considered in ancient Egyptian units, the volume of a sphere, whose circumference is one royal cubit, equals half a hekat. Using the measurements of large sets of ancient containers as a database, the article demonstrates that this formula was characteristic of Egyptian and Egyptian-related pottery vessels but not of the ceramics of Mesopotamia, which had a different system of measuring length and volume units. PMID:22470489

Sunspot rotation. II. Effects of varying the field strength and twist of an emerging flux tube

NASA Astrophysics Data System (ADS)

Sturrock, Z.; Hood, A. W.

2016-09-01

Context. Observations of flux emergence indicate that rotational velocities may develop within sunspots. However, the dependence of this rotation on sub-photospheric field strength and twist remains largely unknown. Aims: We investigate the effects of varying the initial field strength and twist of an emerging sub-photospheric magnetic flux tube on the rotation of the sunspots at the photosphere. Methods: We consider a simple model of a stratified domain with a sub-photospheric interior layer and three overlying atmospheric layers. A twisted arched flux tube is inserted in the interior and is allowed to rise into the atmosphere. To achieve this, the magnetohydrodynamic equations are solved using the Lagrangian-remap code, Lare3d. We perform a parameter study by independently varying the sub-photospheric magnetic field strength and twist. Results: Altering the initial magnetic field strength and twist of the flux tube significantly affects the tube's evolution and the rotational motions that develop at the photosphere. The rotation angle, vorticity, and current show a direct dependence on the initial field strength. We find that an increase in field strength increases the angle through which the fieldlines rotate, the length of the fieldlines extending into the atmosphere, and the magnetic energy transported to the atmosphere. This also affects the amount of residual twist in the interior. The length of the fieldlines is crucial as we predict the twist per unit length equilibrates to a lower value on longer fieldlines. No such direct dependence is found when we modify the twist of the magnetic field owing to the complex effect this has on the tension force acting on the tube. However, there is still a clear ordering in quantities such as the rotation angle, helicity, and free energy with higher initial twist cases being related to sunspots that rotate more rapidly, transporting more helicity and magnetic energy to the atmosphere.

Olefin unit primary fractionator on-line Petro-Blast Lancing

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

Adams, W.D.; Rutan, C.R.

1994-12-31

Today`s commodity chemicals market forces companies to find innovative ways to extend unit on line operation between turnarounds such that they will remain economically competitive. At the OxyChem Chocolate Bayou facility the Primary Fractionator, quench oil column, fouling defined the length of the run between Olefin Unit turnarounds. Polymer growth on the valve trays restricted vapor flow through the column. This increased the column pressure drop which resulted in severe flooding. The inability to cool the furnace effluent while separating the fuel oil and gasoline components would cause premature shutdowns. Fouling locations were defined using gamma scan techniques and pressuremore » surveys. Nozzles were welded and hot tapped at strategic locations around the column. A high pressure Petro-Blast Lancing technique, inserted through the nozzles, was then used to clean the trays. The operation has extended the unit run length although the column may require additional Petro-Blast Lancing before the next scheduled plant turnaround. If this schedule holds, a two year extension in the unit run length will be realized.« less

Patient safety culture at neonatal intensive care units: perspectives of the nursing and medical team 1

PubMed Central

Tomazoni, Andréia; Rocha, Patrícia Kuerten; de Souza, Sabrina; Anders, Jane Cristina; de Malfussi, Hamilton Filipe Correia

2014-01-01

OBJECTIVE: to verify the assessment of the patient safety culture according to the function and length of experience of the nursing and medical teams at Neonatal Intensive Care Units. METHOD: quantitative survey undertaken at four Neonatal Intensive Care Units in Florianópolis, Brazil. The sample totaled 141 subjects. The data were collected between February and April 2013 through the application of the Hospital Survey on Patient Safety Culture. For analysis, the Kruskal-Wallis and Chi-Square tests and Cronbach's Alpha coefficient were used. Approval for the research project was obtained from the Ethics Committee, CAAE: 05274612.7.0000.0121. RESULTS: differences in the number of positive answers to the Hospital Survey on Patient Safety Culture, the safety grade and the number of reported events were found according to the professional characteristics. A significant association was found between a shorter Length of work at the hospital and Length of work at the unit and a larger number of positive answers; longer length of experience in the profession represented higher grades and less reported events. The physicians and nursing technicians assessed the patient safety culture more positively. Cronbach's alpha demonstrated the reliability of the instrument. CONCLUSION: the differences found reveal a possible relation between the assessment of the safety culture and the subjects' professional characteristics at the Neonatal Intensive Care Units. PMID:25493670

Proposed standard-weight equations for brook trout

USGS Publications Warehouse

Hyatt, M.W.; Hubert, W.A.

2001-01-01

Weight and length data were obtained for 113 populations of brook trout Salvelinus fontinalis across the species' geographic range in North America to estimate a standard-weight (Ws) equation for this species. Estimation was done by applying the regression-line-percentile technique to fish of 120-620 mm total length (TL). The proposed metric-unit (g and mm) equation is log10Ws = -5.186 + 3.103 log10TL; the English-unit (lb and in) equivalent is log10Ws = -3.483 + 3.103 log10TL. No systematic length bias was evident in the relative-weight values calculated from these equations.

Understanding linear measurement: A comparison of filipino and new zealand children

NASA Astrophysics Data System (ADS)

Irwin, Kathryn C.; Ell, Fiona R.; Vistro-Yu, Catherine P.

2004-06-01

An understanding of linear measurement depends on principles that include standard unit size, iteration of units, numbering of a unit at its end, and partial units for measuring continuous length. Children may learn these principles at school, for example through experience with informal measurement, or they may learn them through use of measurement in society. This study compared the application of these principles by children aged 8 and 9 from the Philippines and New Zealand. These countries were selected because they have quite different curricula, societal influences and economies. Ninety-one children were interviewed individually on a common set of unusual tasks that were designed to tap underlying principles. Results showed many similarities and some differences between countries. Most tasks requiring visualisation and informal units were done more accurately by New Zealand children. Some tasks involving the use of a conventional ruler were done more accurately by Filipino children. These differences appear to be related to differences in curricula and possibly to differences in societal use of measurement. We suggest that these results, like those of other writers cited, demonstrate the need for extensive work on the underlying concepts in measurement through work on informal measurement and a careful transition between informal and formal measurement.

Thermally induced charge current through long molecules

NASA Astrophysics Data System (ADS)

Zimbovskaya, Natalya A.; Nitzan, Abraham

2018-01-01

In this work, we theoretically study steady state thermoelectric transport through a single-molecule junction with a long chain-like bridge. Electron transmission through the system is computed using a tight-binding model for the bridge. We analyze dependences of thermocurrent on the bridge length in unbiased and biased systems operating within and beyond the linear response regime. It is shown that the length-dependent thermocurrent is controlled by the lineshape of electron transmission in the interval corresponding to the HOMO/LUMO transport channel. Also, it is demonstrated that electron interactions with molecular vibrations may significantly affect the length-dependent thermocurrent.

The Changing Nature of the Chemical Bond

NASA Astrophysics Data System (ADS)

Angel, R. J.; Ross, N. L.; Zhao, J.

2006-12-01

It is commonly assumed that the relationship between bond strength and bond length for a particular pair of atoms is a simple and single-valued one for a given coordination environment; longer bonds are weaker. This is the basis of the concept of bond valence, for example. Indeed, in strongly-bonded oxide minerals, the range of bond lengths found for a given cation-anion polyhedron is so small that it was long thought that the polyhedral bulk moduli were essentially independent of structure type and thus the environment of the polyhedron. This view is incompatible with the discovery that the response of the perovskite structure to high pressures is controlled by the equipartition of bond-valence strain between the A and B cation sites within the structure [1]. The same appears to be true, within experimental uncertainties, for all framework structures with rigid-unit modes. In perovskites, this explicitly implies that the octahedral compressibility depends not only upon the octahedral cation, but also upon the compressibility of the cation-oxygen bonds of the extra-framework (nominally dodecahedral) site. Thus the octahedral compressibility of a B cation site must change as the A- site cation is changed, whether or not the B-O bond lengths change as a result of the substitution on the A site. The strength of bonds is thus dependent upon the crystal environment and not solely upon the bond length. The observation of a plateau effect in the variation of octahedral compressibilities in perovskite solid solutions suggests that the bond-valence matching principle is followed not just globally, but on a local scale as well. Such observations should allow the change with pressure of the excess thermodynamic properties of solid solutions to be directly related to the microscopic (atomic scale) evolution of the structure. [1] Zhao, Ross, & Angel (2004). Acta Cryst. B60:263

[Correlation between body mass index and development of pressure ulcers in intensive care medicine].

PubMed

Catalá Espinosa, A I; Hidalgo Encinas, Y; Cherednichenko, T; Flores Lucas, I; González Tamayo, R; García-Martínez, M Á; Herrero-Gutiérrez, E

2014-01-01

This study aims to evaluate the association between body mass index (BMI), incidence and severity of pressure ulcers (PU) in patients admitted to the Intensive Care Unit (ICU), and describe the differential prognosis of patients with PU and factors that modify it. Case-control study with observation period of 15 months. We collected baseline variables, prognostic scales, therapies and clinical outcome. Univariate analysis was performed for each outcome variable between cases and controls using the appropriate hypothesis test depending on the nature of the variables. ROC curve for BMI and PU. Logistic regression with PU as dependent variable and the covariates that reached p<0.05 in the bivariate analysis. Correlation using Pearson or Spearman was made between BMI, albumin, days to diagnosis of UPP, immobilization, and PU degree. Significance level at p <0.05. 77 patients developed PU and 231 controls were chosen. The cases had higher APACHE II (p=0.043) and SAPS 3 (p=0.023), length of stay in ICU and mechanical ventilation (p<0.001). BMI≥40 was associated with UPP (p=0.024 OR=3.23 CI95% 1.17-8.93). There was a significant association between PU degree, length of stay and MV (p<0,001), but not with immobilization, dynamic support surface and death rate. Multivariate analysis found association between PU, length of MV (p=0.013, OR 1.08, CI95% 1.01-1.16) and kidney replacement therapy (p=0.013, OR 3.55 CI95% 1.31-9.64), with BMI≥40 as a confounding factor. Length of mechanical ventilation and renal replacement therapy are risk factors for pressure ulcer development, and BMI≥40 acts as a confounding factor. PU development and its maximum degree are not associated with a worse prognosis. Copyright © 2013 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

Assessment of the Sensitivity to the Thermal Roughness Length in Noah and Noah-MP Land Surface Model Using WRF in an Arid Region

NASA Astrophysics Data System (ADS)

Weston, Michael; Chaouch, Naira; Valappil, Vineeth; Temimi, Marouane; Ek, Michael; Zheng, Weizhong

2018-06-01

Atmospheric models are known to underestimate land surface temperature and, by association, 2 m air temperature over dry arid regions during the day due to the treatment of the thermal roughness length also known as roughness length of heat. The thermal roughness length can be controlled by the Zilitinkevich parameter, known as Czil, which is a tunable parameter within the models. Three different scenarios with the WRF model are run to test the impact of the Czil parameter on the simulations using two land surface models: the Noah and Noah-MP models. In this study, a modified version of the Noah-MP model is tested, in which the Czil parameter, and, therefore, the thermal roughness length varies depending on the land cover and vegetation height. The model domain is over the United Arab Emirates (UAE) where the major land cover type is desert. The following configurations are tested: the Noah model with Czil = 0.1, Noah model with Czil = 0.5 and the Noah-MP model with Czil = 0.5 over desert. Results of 2 m air temperature are verified against three stations in the UAE. Mean gross error of the diurnal 2 m temperature was reduced by up to 1.48 and 1.54 °C in the 24 and 48 h forecasts, respectively. This reduced the cold bias in the model. This improvement in air temperature showed to improve the diurnal cycle of relative humidity at the three monitoring stations as well as the duration of the sea breeze in some cases.

Local atomic and magnetic structure of dilute magnetic semiconductor (Ba ,K ) (Zn,Mn ) 2As2

NASA Astrophysics Data System (ADS)

Frandsen, Benjamin A.; Gong, Zizhou; Terban, Maxwell W.; Banerjee, Soham; Chen, Bijuan; Jin, Changqing; Feygenson, Mikhail; Uemura, Yasutomo J.; Billinge, Simon J. L.

2016-09-01

We have studied the atomic and magnetic structure of the dilute ferromagnetic semiconductor system (Ba ,K )(Zn ,Mn )2As2 through atomic and magnetic pair distribution function analysis of temperature-dependent x-ray and neutron total scattering data. We detected a change in curvature of the temperature-dependent unit cell volume of the average tetragonal crystallographic structure at a temperature coinciding with the onset of ferromagnetic order. We also observed the existence of a well-defined local orthorhombic structure on a short length scale of ≲5 Å , resulting in a rather asymmetrical local environment of the Mn and As ions. Finally, the magnetic PDF revealed ferromagnetic alignment of Mn spins along the crystallographic c axis, with robust nearest-neighbor ferromagnetic correlations that exist even above the ferromagnetic ordering temperature. We discuss these results in the context of other experiments and theoretical studies on this system.

Tunable thermoresponsive pyrrolidone-based polymers from pyroglutamic acid, a bio-derived resource.

PubMed

Bhat, Rajani; Pietrangelo, Agostino

2013-03-12

A series of pyrrolidone-based polymers is prepared from pyroglutamic acid, a bio-derived resource. Polymers bearing simple alkoxy substituents (e.g., methoxy, ethoxy, and butoxy) are soluble in common organic solvents and possess glass transition temperatures that are dependent on the length of the alkoxy residue. Replacing these substituents with an ether moiety (CH3 OCH2 CH2 O-) affords a highly sensitive and reversible thermoresponsive polymer with a lower critical solution temperature (LCST) of 42 °C in water. Copolymers composed of repeat units bearing both the ether and simple alkoxy residues are found to exhibit LCSTs that are highly dependent on the nature of the hydrophobic alkoxy residue suggesting that the LCSTs of these polymers can be successfully tuned by simply tailoring the copolymer structure. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cosmic-ray elemental abundances from 1 to 10 GeV per amu for boron through nickel

NASA Technical Reports Server (NTRS)

Dwyer, Robert; Meyer, Peter

1987-01-01

The relative abundances of cosmic-ray nuclei in the charge range boron through nickel over the energy range 1-10 GeV per amu were measured with a balloon-borne detector. The instrument consists of a scintillation and Cerenkov counter telescope with a multiwire proportional chamber hodoscope and has been flown in four high-altitude balloon flights. Good charge resolution (sigma = 0.2 charge units at iron) and high statistical accuracy have been achieved. These data are used to derive the energy dependence of the leakage path length using the leaky box model of propagation and confinement in the galaxy. This energy dependence is found to be best fit by lambda = E(tot) exp -n, where n = 0.49 + or - 0.06 over 1-10 GeV per amu. Relative abundances at the source are consistent with an energy-independent composition.

Invariance of single-file water mobility in gramicidin-like peptidic pores as function of pore length.

PubMed

Portella, Guillem; Pohl, Peter; de Groot, Bert L

2007-06-01

We investigated the structural and energetic determinants underlying water permeation through peptidic nanopores, motivated by recent experimental findings that indicate that water mobility in single-file water channels displays nonlinear length dependence. To address the molecular mechanism determining the observed length dependence, we studied water permeability in a series of designed gramicidin-like channels of different length using atomistic molecular dynamics simulations. We found that within the studied range of length the osmotic water permeability is independent of pore length. This result is at variance with textbook models, where the relationship is assumed to be linear. Energetic analysis shows that loss of solvation rather than specific water binding sites in the pore form the main energetic barrier for water permeation, consistent with our dynamics results. For this situation, we propose a modified expression for osmotic permeability that fully takes into account water motion collectivity and does not depend on the pore length. Different schematic barrier profiles are discussed that explain both experimental and computational interpretations, and we propose a set of experiments aimed at validation of the presented results. Implications of the results for the design of peptidic channels with desired permeation characteristics are discussed.

The snakelike chain character of unstructured RNA.

PubMed

Jacobson, David R; McIntosh, Dustin B; Saleh, Omar A

2013-12-03

In the absence of base-pairing and tertiary structure, ribonucleic acid (RNA) assumes a random-walk conformation, modulated by the electrostatic self-repulsion of the charged, flexible backbone. This behavior is often modeled as a Kratky-Porod "wormlike chain" (WLC) with a Barrat-Joanny scale-dependent persistence length. In this study we report measurements of the end-to-end extension of poly(U) RNA under 0.1 to 10 pN applied force and observe two distinct elastic-response regimes: a low-force, power-law regime characteristic of a chain of swollen blobs on long length scales and a high-force, salt-valence-dependent regime consistent with ion-stabilized crumpling on short length scales. This short-scale structure is additionally supported by force- and salt-dependent quantification of the RNA ion atmosphere composition, which shows that ions are liberated under stretching; the number of ions liberated increases with increasing bulk salt concentration. Both this result and the observation of two elastic-response regimes directly contradict the WLC model, which predicts a single elastic regime across all forces and, when accounting for scale-dependent persistence length, the opposite trend in ion release with salt concentration. We conclude that RNA is better described as a "snakelike chain," characterized by smooth bending on long length scales and ion-stabilized crumpling on short length scales. In monovalent salt, these two regimes are separated by a characteristic length that scales with the Debye screening length, highlighting the determining importance of electrostatics in RNA conformation. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Sequence-Dependent Persistence Length of Long DNA

NASA Astrophysics Data System (ADS)

Chuang, Hui-Min; Reifenberger, Jeffrey G.; Cao, Han; Dorfman, Kevin D.

2017-12-01

Using a high-throughput genome-mapping approach, we obtained circa 50 million measurements of the extension of internal human DNA segments in a 41 nm ×41 nm nanochannel. The underlying DNA sequences, obtained by mapping to the reference human genome, are 2.5-393 kilobase pairs long and contain percent GC contents between 32.5% and 60%. Using Odijk's theory for a channel-confined wormlike chain, these data reveal that the DNA persistence length increases by almost 20% as the percent GC content increases. The increased persistence length is rationalized by a model, containing no adjustable parameters, that treats the DNA as a statistical terpolymer with a sequence-dependent intrinsic persistence length and a sequence-independent electrostatic persistence length.

Complex myograph allows the examination of complex muscle contractions for the assessment of muscle force, shortening, velocity, and work in vivo

PubMed Central

Rahe-Meyer, Niels; Pawlak, Matthias; Weilbach, Christian; Osthaus, Wilhelm Alexander; Ruhschulte, Hainer; Solomon, Cristina; Piepenbrock, Siegfried; Winterhalter, Michael

2008-01-01

Background The devices used for in vivo examination of muscle contractions assess only pure force contractions and the so-called isokinetic contractions. In isokinetic experiments, the extremity and its muscle are artificially moved with constant velocity by the measuring device, while a tetanic contraction is induced in the muscle, either by electrical stimulation or by maximal voluntary activation. With these systems, experiments cannot be performed at pre-defined, constant muscle length, single contractions cannot be evaluated individually and the separate examination of the isometric and the isotonic components of single contractions is not possible. Methods The myograph presented in our study has two newly developed technical units, i.e. a). a counterforce unit which can load the muscle with an adjustable, but constant force and b). a length-adjusting unit which allows for both the stretching and the contraction length to be infinitely adjustable independently of one another. The two units support the examination of complex types of contraction and store the counterforce and length-adjusting settings, so that these conditions may be accurately reapplied in later sessions. Results The measurement examples presented show that the muscle can be brought to every possible pre-stretching length and that single isotonic or complex isometric-isotonic contractions may be performed at every length. The applied forces act during different phases of contraction, resulting into different pre- and after-loads that can be kept constant – uninfluenced by the contraction. Maximal values for force, shortening, velocity and work may be obtained for individual muscles. This offers the possibility to obtain information on the muscle status and to monitor its changes under non-invasive measurement conditions. Conclusion With the Complex Myograph, the whole spectrum of a muscle's mechanical characteristics may be assessed. PMID:18616815

[Assessment of Three Risk Adjustment Systems as Predictors of the Consumption of Medicines and Medical Supplies at Polyvalent Hospitalization Units. Spain].

PubMed

Mera Flores, Ana María; Del Busto Bonifaz, Sebastián; Bernal Sobrino, José Luis

2016-09-26

The use of medicines and medical supplies is a significant component of health expenditure, linked to healthcare quality and efficient resource allocation. This study aimed to evaluate three risk adjustment systems predictive power of the consumption of medicines and medical supplies at polyvalent hospitalization units (PHU). This is an observational, retrospective study of the resources utilization in PHU between 2010 and 2013. We fitted linear regression models and evaluated their goodness of fit for three different predictors: Charlson Comorbidity Index (CCI), All Patients DRG (AP-DRG) and All Patients Refined DRG (APR-DRG) relative weights, and each one of them corrected by the length of stay. We analyzed hospitalization episodes included in the Minimum Basic Data Set (MBDS) from Fuenlabrada University Hospital. Data about the use of medicines and medical supplies were obtained from pharmacy and supply chain management information systems. Significant correlation was found between the annual consumption and the predictors considered (r=0,879 for CCI; r=0,622 for AP-DRG and r=0,514 for APR-DRG). The CCI corrected by length of stay was the variable that best fit presented (Ṝ2=0,863). The best predictive ability of CCI indicates that resource utilization depends more of the concurrent presence of additional pathology than the case mix calculated for iso-resource groups.

Morphological variation and zoogeography of racers (Coluber constrictor) in the central Rocky Mountains

USGS Publications Warehouse

Corn, Paul Stephen; Bury, R. Bruce

1986-01-01

We examined 63 specimens of Coluber constrictor from Colorado and Utah using eight external morphological characters that have been used to distinguish C. c. mormon from C. c. flaviventris. We grouped the snakes into three Operational Taxonomic Units (OTU's) in a transect across the Rocky Mountains: the eastern Front Range foothills in Colorado; the inter-mountain region (western slope of Colorado and northeastern Utah); and the western foothills of the Wasatch Mountains in Utah. Statistically significant variation among the OTU's was discovered for ration of tail length to total length, number of central and subcaudal scales, and number of dentary teeth. However, variation is clinal with nearly complete overlap from one end f the transect to the other for each character, suggesting a wide zone of intergradiation in the inter-mountain region. We do not believe reported differences in reproductive parameters between Great Plains and Great Basin racers are sufficient grounds for recognition of species, because clutch size is both geographically variable and dependent on the environment. The distribution of C. constrictor is similar to that of other reptiles with transmontane distributions in the western United States, and we suggest two possible routes of dispersal across the Continental Divide in southwestern Wyoming. Thus, elevation of C. c. mormon to species status is not supported by morphological, reproductive, or zoogeographic evidence.

7 CFR 28.303 - Standards for length of staple for American upland cotton.

Code of Federal Regulations, 2013 CFR

2013-01-01

... cotton. 28.303 Section 28.303 Agriculture Regulations of the Department of Agriculture AGRICULTURAL... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.303 Standards for length of staple for...

7 CFR 28.303 - Standards for length of staple for American upland cotton.

Code of Federal Regulations, 2011 CFR

2011-01-01

... cotton. 28.303 Section 28.303 Agriculture Regulations of the Department of Agriculture AGRICULTURAL... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.303 Standards for length of staple for...

7 CFR 28.303 - Standards for length of staple for American upland cotton.

Code of Federal Regulations, 2014 CFR

2014-01-01

... cotton. 28.303 Section 28.303 Agriculture Regulations of the Department of Agriculture AGRICULTURAL... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.303 Standards for length of staple for...

7 CFR 28.303 - Standards for length of staple for American upland cotton.

Code of Federal Regulations, 2012 CFR

2012-01-01

... cotton. 28.303 Section 28.303 Agriculture Regulations of the Department of Agriculture AGRICULTURAL... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.303 Standards for length of staple for...

7 CFR 28.303 - Standards for length of staple for American upland cotton.

Code of Federal Regulations, 2010 CFR

2010-01-01

... cotton. 28.303 Section 28.303 Agriculture Regulations of the Department of Agriculture AGRICULTURAL... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.303 Standards for length of staple for...

5 CFR 838.441 - Computing lengths of service.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Computing lengths of service. 838.441... Affecting Refunds of Employee Contributions Procedures for Computing the Amount Payable § 838.441 Computing lengths of service. (a) The smallest unit of time that OPM will calculate in computing a formula in a...

Education on invasive mechanical ventilation involving intensive care nurses: a systematic review.

PubMed

Guilhermino, Michelle C; Inder, Kerry J; Sundin, Deborah

2018-03-26

Intensive care unit nurses are critical for managing mechanical ventilation. Continuing education is essential in building and maintaining nurses' knowledge and skills, potentially improving patient outcomes. The aim of this study was to determine whether continuing education programmes on invasive mechanical ventilation involving intensive care unit nurses are effective in improving patient outcomes. Five electronic databases were searched from 2001 to 2016 using keywords such as mechanical ventilation, nursing and education. Inclusion criteria were invasive mechanical ventilation continuing education programmes that involved nurses and measured patient outcomes. Primary outcomes were intensive care unit mortality and in-hospital mortality. Secondary outcomes included hospital and intensive care unit length of stay, length of intubation, failed weaning trials, re-intubation incidence, ventilation-associated pneumonia rate and lung-protective ventilator strategies. Studies were excluded if they excluded nurses, patients were ventilated for less than 24 h, the education content focused on protocol implementation or oral care exclusively or the outcomes were participant satisfaction. Quality was assessed by two reviewers using an education intervention critical appraisal worksheet and a risk of bias assessment tool. Data were extracted independently by two reviewers and analysed narratively due to heterogeneity. Twelve studies met the inclusion criteria for full review: 11 pre- and post-intervention observational and 1 quasi-experimental design. Studies reported statistically significant reductions in hospital length of stay, length of intubation, ventilator-associated pneumonia rates, failed weaning trials and improvements in lung-protective ventilation compliance. Non-statistically significant results were reported for in-hospital and intensive care unit mortality, re-intubation and intensive care unit length of stay. Limited evidence of the effectiveness of continuing education programmes on mechanical ventilation involving nurses in improving patient outcomes exists. Comprehensive continuing education is required. Well-designed trials are required to confirm that comprehensive continuing education involving intensive care nurses about mechanical ventilation improves patient outcomes. © 2018 British Association of Critical Care Nurses.

Relation of Callous-Unemotional Traits to Length of Stay among Youth Hospitalized at a State Psychiatric Inpatient Facility

ERIC Educational Resources Information Center

Stellwagen, Kurt K.; Kerig, Patricia K.

2010-01-01

We examined the association of callous-unemotional (C/U) traits with length of psychiatric hospitalization among two samples each with 50 participants: a group of 7-11 year-olds (39 males and 11 females) receiving services on a children's unit, and a group of 12-17 year-olds (27 males and 23 females) receiving services on an adolescent unit. Our…

Fractal-Based Lightning Channel Length Estimation from Convex-Hull Flash Areas for DC3 Lightning Mapping Array Data

NASA Technical Reports Server (NTRS)

Bruning, Eric C.; Thomas, Ronald J.; Krehbiel, Paul R.; Rison, William; Carey, Larry D.; Koshak, William; Peterson, Harold; MacGorman, Donald R.

2013-01-01

We will use VHF Lightning Mapping Array data to estimate NOx per flash and per unit channel length, including the vertical distribution of channel length. What s the best way to find channel length from VHF sources? This paper presents the rationale for the fractal method, which is closely related to the box-covering method.

Temperature-sensitive elastin-mimetic dendrimers: Effect of peptide length and dendrimer generation to temperature sensitivity.

PubMed

Kojima, Chie; Irie, Kotaro; Tada, Tomoko; Tanaka, Naoki

2014-06-01

Dendrimers are synthetic macromolecules with unique structure, which are a potential scaffold for peptides. Elastin is one of the main components of extracellular matrix and a temperature-sensitive biomacromolecule. Previously, Val-Pro-Gly-Val-Gly peptides have been conjugated to a dendrimer for designing an elastin-mimetic dendrimer. In this study, various elastin-mimetic dendrimers using different length peptides and different dendrimer generations were synthesized to control the temperature dependency. The elastin-mimetic dendrimers formed β-turn structure by heating, which was similar to the elastin-like peptides. The elastin-mimetic dendrimers exhibited an inverse phase transition, largely depending on the peptide length and slightly depending on the dendrimer generation. The elastin-mimetic dendrimers formed aggregates after the phase transition. The endothermal peak was observed in elastin-mimetic dendrimers with long peptides, but not with short ones. The peptide length and the dendrimer generation are important factors to tune the temperature dependency on the elastin-mimetic dendrimer. Copyright © 2013 Wiley Periodicals, Inc.

Dependence of the bit error rate on the signal power and length of a single-channel coherent single-span communication line (100 Gbit s{sup -1}) with polarisation division multiplexing

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

Gurkin, N V; Konyshev, V A; Novikov, A G

2015-01-31

We have studied experimentally and using numerical simulations and a phenomenological analytical model the dependences of the bit error rate (BER) on the signal power and length of a coherent single-span communication line with transponders employing polarisation division multiplexing and four-level phase modulation (100 Gbit s{sup -1} DP-QPSK format). In comparing the data of the experiment, numerical simulations and theoretical analysis, we have found two optimal powers: the power at which the BER is minimal and the power at which the fade margin in the line is maximal. We have derived and analysed the dependences of the BER on themore » optical signal power at the fibre line input and the dependence of the admissible input signal power range for implementation of the communication lines with a length from 30 – 50 km up to a maximum length of 250 km. (optical transmission of information)« less

Elasticity of short DNA molecules: theory and experiment for contour lengths of 0.6-7 microm.

PubMed

Seol, Yeonee; Li, Jinyu; Nelson, Philip C; Perkins, Thomas T; Betterton, M D

2007-12-15

The wormlike chain (WLC) model currently provides the best description of double-stranded DNA elasticity for micron-sized molecules. This theory requires two intrinsic material parameters-the contour length L and the persistence length p. We measured and then analyzed the elasticity of double-stranded DNA as a function of L (632 nm-7.03 microm) using the classic solution to the WLC model. When the elasticity data were analyzed using this solution, the resulting fitted value for the persistence length p(wlc) depended on L; even for moderately long DNA molecules (L = 1300 nm), this apparent persistence length was 10% smaller than its limiting value for long DNA. Because p is a material parameter, and cannot depend on length, we sought a new solution to the WLC model, which we call the "finite wormlike chain (FWLC)," to account for effects not considered in the classic solution. Specifically we accounted for the finite chain length, the chain-end boundary conditions, and the bead rotational fluctuations inherent in optical trapping assays where beads are used to apply the force. After incorporating these corrections, we used our FWLC solution to generate force-extension curves, and then fit those curves with the classic WLC solution, as done in the standard experimental analysis. These results qualitatively reproduced the apparent dependence of p(wlc) on L seen in experimental data when analyzed with the classic WLC solution. Directly fitting experimental data to the FWLC solution reduces the apparent dependence of p(fwlc) on L by a factor of 3. Thus, the FWLC solution provides a significantly improved theoretical framework in which to analyze single-molecule experiments over a broad range of experimentally accessible DNA lengths, including both short (a few hundred nanometers in contour length) and very long (microns in contour length) molecules.

Intraflagellar transport particle size scales inversely with flagellar length: revisiting the balance-point length control model.

PubMed

Engel, Benjamin D; Ludington, William B; Marshall, Wallace F

2009-10-05

The assembly and maintenance of eukaryotic flagella are regulated by intraflagellar transport (IFT), the bidirectional traffic of IFT particles (recently renamed IFT trains) within the flagellum. We previously proposed the balance-point length control model, which predicted that the frequency of train transport should decrease as a function of flagellar length, thus modulating the length-dependent flagellar assembly rate. However, this model was challenged by the differential interference contrast microscopy observation that IFT frequency is length independent. Using total internal reflection fluorescence microscopy to quantify protein traffic during the regeneration of Chlamydomonas reinhardtii flagella, we determined that anterograde IFT trains in short flagella are composed of more kinesin-associated protein and IFT27 proteins than trains in long flagella. This length-dependent remodeling of train size is consistent with the kinetics of flagellar regeneration and supports a revised balance-point model of flagellar length control in which the size of anterograde IFT trains tunes the rate of flagellar assembly.

Underscreening in concentrated electrolytes.

PubMed

Lee, Alpha A; Perez-Martinez, Carla S; Smith, Alexander M; Perkin, Susan

2017-07-01

Screening of a surface charge by an electrolyte and the resulting interaction energy between charged objects is of fundamental importance in scenarios from bio-molecular interactions to energy storage. The conventional wisdom is that the interaction energy decays exponentially with object separation and the decay length is a decreasing function of ion concentration; the interaction is thus negligible in a concentrated electrolyte. Contrary to this conventional wisdom, we have shown by surface force measurements that the decay length is an increasing function of ion concentration and Bjerrum length for concentrated electrolytes. In this paper we report surface force measurements to test directly the scaling of the screening length with Bjerrum length. Furthermore, we identify a relationship between the concentration dependence of this screening length and empirical measurements of activity coefficient and differential capacitance. The dependence of the screening length on the ion concentration and the Bjerrum length can be explained by a simple scaling conjecture based on the physical intuition that solvent molecules, rather than ions, are charge carriers in a concentrated electrolyte.

The Optimal Lateral Root Branching Density for Maize Depends on Nitrogen and Phosphorus Availability1[C][W][OPEN

PubMed Central

Postma, Johannes Auke; Dathe, Annette; Lynch, Jonathan Paul

2014-01-01

Observed phenotypic variation in the lateral root branching density (LRBD) in maize (Zea mays) is large (1–41 cm−1 major axis [i.e. brace, crown, seminal, and primary roots]), suggesting that LRBD has varying utility and tradeoffs in specific environments. Using the functional-structural plant model SimRoot, we simulated the three-dimensional development of maize root architectures with varying LRBD and quantified nitrate and phosphorus uptake, root competition, and whole-plant carbon balances in soils varying in the availability of these nutrients. Sparsely spaced (less than 7 branches cm−1), long laterals were optimal for nitrate acquisition, while densely spaced (more than 9 branches cm−1), short laterals were optimal for phosphorus acquisition. The nitrate results are mostly explained by the strong competition between lateral roots for nitrate, which causes increasing LRBD to decrease the uptake per unit root length, while the carbon budgets of the plant do not permit greater total root length (i.e. individual roots in the high-LRBD plants stay shorter). Competition and carbon limitations for growth play less of a role for phosphorus uptake, and consequently increasing LRBD results in greater root length and uptake. We conclude that the optimal LRBD depends on the relative availability of nitrate (a mobile soil resource) and phosphorus (an immobile soil resource) and is greater in environments with greater carbon fixation. The median LRBD reported in several field screens was 6 branches cm−1, suggesting that most genotypes have an LRBD that balances the acquisition of both nutrients. LRBD merits additional investigation as a potential breeding target for greater nutrient acquisition. PMID:24850860

Length of urban residence and obesity among within-country rural-to-urban Andean migrants.

PubMed

Antiporta, Daniel A; Smeeth, Liam; Gilman, Robert H; Miranda, J Jaime

2016-05-01

To evaluate the association between length of residence in an urban area and obesity among Peruvian rural-to-urban migrants. Cross-sectional database analysis of the migrant group from the PERU MIGRANT Study (2007). Exposure was length of urban residence, analysed as both a continuous (10-year units) and a categorical variable. Four skinfold site measurements (biceps, triceps, subscapular and suprailiac) were used to calculate body fat percentage and obesity (body fat percentage >25% males, >33% females). We used Poisson generalized linear models to estimate adjusted prevalence ratios and 95 % confidence intervals. Multicollinearity between age and length of urban residence was assessed using conditional numbers and correlation tests. A peri-urban shantytown in the south of Lima, Peru. Rural-to-urban migrants (n 526) living in Lima. Multivariable analyses showed that for each 10-year unit increase in residence in an urban area, rural-to-urban migrants had, on average, a 12 % (95 % CI 6, 18 %) higher prevalence of obesity. This association was also present when length of urban residence was analysed in categories. Sensitivity analyses, conducted with non-migrant groups, showed no evidence of an association between 10-year age units and obesity in rural (P=0·159) or urban populations (P=0·078). High correlation and a large conditional number between age and length of urban residence were found, suggesting a strong collinearity between both variables. Longer lengths of urban residence are related to increased obesity in rural-to-urban migrant populations; therefore, interventions to prevent obesity in urban areas may benefit from targeting migrant groups.

Structural and rectifying junction properties of self-assembled ZnO nanoparticles in polystyrene diblock copolymers on (1 0 0)Si substrates

NASA Astrophysics Data System (ADS)

Ali, H. A.; Iliadis, A. A.; Martinez-Miranda, L. J.; Lee, U.

2006-06-01

The structural and electronic transport properties of self-assembled ZnO nanoparticles in polystyrene-acrylic acid, [PS] m/[PAA] n, diblock copolymer on p-type (1 0 0)Si substrates are reported for the first time. Four different block repeat unit ratios ( m/ n) of 159/63, 139/17,106/17, and 106/4, were examined in order to correlate the physical parameters (size, density) of the nanoparticles with the copolymer block lengths m and n. We established that the self-assembled ZnO nanoparticle average size increased linearly with minority block length n, while the average density decreased exponentially with majority block length m. Average size varied from 20 nm to 250 nm and average density from 3.5 × 10 7 cm -2 to 1 × 10 10 cm -2, depending on copolymer parameters. X-ray diffraction studies showed the particles to have a wurtzite crystal structure with the (1 0 0) being the dominant orientation. Room temperature current-voltage characteristics measured for an Al/ZnO-nanocomposite/Si structure exhibited rectifying junction properties and indicated the formation of Al/ZnO-nanocomposite Schottky type junction with a barrier height of 0.7 V.

Impact of length of cryopreservation and origin of cord blood units on hematologic recovery following cord blood transplantation.

PubMed

Kurita, N; Frassoni, F; Chiba, S; Podestà, M

2015-06-01

As the history of the cord blood banking system has lengthened, the number of cord blood units (CBUs) cryopreserved for years has increased. The global expansion of cord blood banking resulted in active international exchange of CBUs. To determine whether long-term cryopreservation and international shipment of CBUs affect the quality of the units and outcome after transplantation, we retrospectively analyzed the quality of 95 CBUs and the hematologic recovery of 127 patients with hematological malignancy following single-unit cord blood transplantation. Of the 127 CBUs used to transplant, 42 units were cryopreserved for long periods (5-11.8 years), and 44 units were shipped from distant countries. We found that length of cryopreservation and origin of CBUs did not affect the ratio of viable total-nucleated cells after thawing. Also, neutrophil engraftment was not affected by long-term cryopreservation (> 5 years) or origin (from distant countries), (hazard ratio, 0.91 and 1.2; P=0.65 and 0.41; respectively). The number of CD34(+) cells before freezing (> 1.4 cells/kg recipient) was the only factor that enhanced neutrophil engraftment (hazard ratio, 1.8; P<0.01). This suggests that length of cryopreservation and origin need not be prioritized over the CD34(+) cell dose when selecting CBUs.

Thermoelectric efficiency of single-molecule junctions with long molecular linkers.

PubMed

Zimbovskaya, Natalya A

2018-06-18

We report results of theoretical studies of thermoelectric efficiency of single-molecule junctions with long molecular linkers. The linker is simulated by a chain of identical sites described using a tight-binding model. It is shown that thermoelectric figure of merit ZT strongly depends on the bridge length, being controlled by the lineshape of electron transmission function within the tunnel energy range corresponding to HOMO/LUMO transport channel. Using the adopted model we demonstrate that ZT may significantly increase as the linker lengthens, and that gateway states on the bridge (if any) may noticeably affect the length-dependent ZT. Temperature dependences of ZT for various bridge lengths are analyzed. It is shown that broad minima emerge in ZT versus temperature curves whose positions are controlled by the bridge lengths. © 2018 IOP Publishing Ltd.

Modernization of Koesters interferometer and high accuracy calibration gauge blocks

NASA Astrophysics Data System (ADS)

França, R. S.; Silva, I. L. M.; Couceiro, I. B.; Torres, M. A. C.; Bessa, M. S.; Costa, P. A.; Oliveira, W., Jr.; Grieneisen, H. P. H.

2016-07-01

The Optical Metrology Division (Diopt) of Inmetro is responsible for maintaining the national reference of the length unit according to International System of Units (SI) definitions. The length unit is realized by interferometric techniques and is disseminated to the dimensional community through calibrations of gauge blocks. Calibration of large gauge blocks from 100 mm to 1000 mm has been performed by Diopt with a Koesters interferometer with reference to spectral lines of a krypton discharge lamp. Replacement of this lamp by frequency stabilized lasers, traceable now to the time and frequency scale, is described and the first results are reported.

PyMUS: Python-Based Simulation Software for Virtual Experiments on Motor Unit System

PubMed Central

Kim, Hojeong; Kim, Minjung

2018-01-01

We constructed a physiologically plausible computationally efficient model of a motor unit and developed simulation software that allows for integrative investigations of the input–output processing in the motor unit system. The model motor unit was first built by coupling the motoneuron model and muscle unit model to a simplified axon model. To build the motoneuron model, we used a recently reported two-compartment modeling approach that accurately captures the key cell-type-related electrical properties under both passive conditions (somatic input resistance, membrane time constant, and signal attenuation properties between the soma and the dendrites) and active conditions (rheobase current and afterhyperpolarization duration at the soma and plateau behavior at the dendrites). To construct the muscle unit, we used a recently developed muscle modeling approach that reflects the experimentally identified dependencies of muscle activation dynamics on isometric, isokinetic and dynamic variation in muscle length over a full range of stimulation frequencies. Then, we designed the simulation software based on the object-oriented programing paradigm and developed the software using open-source Python language to be fully operational using graphical user interfaces. Using the developed software, separate simulations could be performed for a single motoneuron, muscle unit and motor unit under a wide range of experimental input protocols, and a hierarchical analysis could be performed from a single channel to the entire system behavior. Our model motor unit and simulation software may represent efficient tools not only for researchers studying the neural control of force production from a cellular perspective but also for instructors and students in motor physiology classroom settings. PMID:29695959

PyMUS: Python-Based Simulation Software for Virtual Experiments on Motor Unit System.

PubMed

Kim, Hojeong; Kim, Minjung

2018-01-01

We constructed a physiologically plausible computationally efficient model of a motor unit and developed simulation software that allows for integrative investigations of the input-output processing in the motor unit system. The model motor unit was first built by coupling the motoneuron model and muscle unit model to a simplified axon model. To build the motoneuron model, we used a recently reported two-compartment modeling approach that accurately captures the key cell-type-related electrical properties under both passive conditions (somatic input resistance, membrane time constant, and signal attenuation properties between the soma and the dendrites) and active conditions (rheobase current and afterhyperpolarization duration at the soma and plateau behavior at the dendrites). To construct the muscle unit, we used a recently developed muscle modeling approach that reflects the experimentally identified dependencies of muscle activation dynamics on isometric, isokinetic and dynamic variation in muscle length over a full range of stimulation frequencies. Then, we designed the simulation software based on the object-oriented programing paradigm and developed the software using open-source Python language to be fully operational using graphical user interfaces. Using the developed software, separate simulations could be performed for a single motoneuron, muscle unit and motor unit under a wide range of experimental input protocols, and a hierarchical analysis could be performed from a single channel to the entire system behavior. Our model motor unit and simulation software may represent efficient tools not only for researchers studying the neural control of force production from a cellular perspective but also for instructors and students in motor physiology classroom settings.

Accuracy of acoustic velocity metering systems for measurement of low velocity in open channels

USGS Publications Warehouse

Laenen, Antonius; Curtis, R. E.

1989-01-01

Acoustic velocity meter (AVM) accuracy depends on equipment limitations, the accuracy of acoustic-path length and angle determination, and the stability of the mean velocity to acoustic-path velocity relation. Equipment limitations depend on path length and angle, transducer frequency, timing oscillator frequency, and signal-detection scheme. Typically, the velocity error from this source is about +or-1 to +or-10 mms/sec. Error in acoustic-path angle or length will result in a proportional measurement bias. Typically, an angle error of one degree will result in a velocity error of 2%, and a path-length error of one meter in 100 meter will result in an error of 1%. Ray bending (signal refraction) depends on path length and density gradients present in the stream. Any deviation from a straight acoustic path between transducer will change the unique relation between path velocity and mean velocity. These deviations will then introduce error in the mean velocity computation. Typically, for a 200-meter path length, the resultant error is less than one percent, but for a 1,000 meter path length, the error can be greater than 10%. Recent laboratory and field tests have substantiated assumptions of equipment limitations. Tow-tank tests of an AVM system with a 4.69-meter path length yielded an average standard deviation error of 9.3 mms/sec, and the field tests of an AVM system with a 20.5-meter path length yielded an average standard deviation error of a 4 mms/sec. (USGS)

Effect of short wavelength illumination on the characteristic bulk diffusion length in ribbon silicon solar cells

NASA Technical Reports Server (NTRS)

Ho, C. T.; Mathias, J. D.

1981-01-01

The influence of short wavelength light on the characteristic bulk minority carrier diffusion length of the ribbon silicon photovoltaic cell has been investigated. We have measured the intensity and wavelength dependence of the diffusion length in an EFG ribbon cell, and compared it with a standard Czochralski grown silicon cell. While the various short wavelength illuminations have shown no influence on the diffusion length in the CZ cell, the diffusion lengths in the ribbon cell exhibit a strong dependence on the volume generation rate as well as on the wavelength of the superimposed lights. We have concluded that the trap-filling phenomenon at various depths in the bulk neutral region of the cell is consistent with the experimental observation.

5 CFR 838.242 - Computing lengths of service.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Computing lengths of service. 838.242... Affecting Employee Annuities Procedures for Computing the Amount Payable § 838.242 Computing lengths of service. (a)(1) The smallest unit of time that OPM will calculate in computing a formula in a court order...

Recombinational Cloning Using Gateway and In-Fusion Cloning Schemes

PubMed Central

Throop, Andrea L.; LaBaer, Joshua

2015-01-01

The comprehensive study of protein structure and function, or proteomics, depends on the obtainability of full-length cDNAs in species-specific expression vectors and subsequent functional analysis of the expressed protein. Recombinational cloning is a universal cloning technique based on site-specific recombination that is independent of the insert DNA sequence of interest, which differentiates this method from the classical restriction enzyme-based cloning methods. Recombinational cloning enables rapid and efficient parallel transfer of DNA inserts into multiple expression systems. This unit summarizes strategies for generating expression-ready clones using the most popular recombinational cloning technologies, including the commercially available Gateway® (Life Technologies) and In-Fusion® (Clontech) cloning technologies. PMID:25827088

Odijk excluded volume interactions during the unfolding of DNA confined in a nanochannel.

PubMed

Reifenberger, Jeffrey G; Cao, Han; Dorfman, Kevin D

2018-02-13

We report experimental data on the unfolding of human and E. coli genomic DNA molecules shortly after injection into a 45 nm nanochannel. The unfolding dynamics are deterministic, consistent with previous experiments and modeling in larger channels, and do not depend on the biological origin of the DNA. The measured entropic unfolding force per friction per unit contour length agrees with that predicted by combining the Odijk excluded volume with numerical calculations of the Kirkwood diffusivity of confined DNA. The time scale emerging from our analysis has implications for genome mapping in nanochannels, especially as the technology moves towards longer DNA, by setting a lower bound for the delay time before making a measurement.

Fetal Biometry Studies of Malaysian Pregnant Women and Comparison with International Charts

NASA Astrophysics Data System (ADS)

Adam, N.; Ramli, R. M.; Jaafar, M. S.

2010-07-01

Fetal biometry is a measurement done on fetus anatomy to relate the fetus growth with gestational age (GA). In this study [1], fetal biometry that was studied consists of biparietal diameter (BPD), abdominal circumference (AC) and femur length (FL). Studies were carried out at Maternity Unit, Hospital Pulau Penang. From the finding, it is understood that fetal biometry distinguish the normal from abnormal fetal structures and it vary among different populations, depending upon their racial [2,3] and nutrition [4,5,6]. True findings are valuable in estimating the gestational age of the fetus, abnormalities in fetus and the consideration of maternal health specific to the Malaysian population.

Monte Carlo Simulation of Endlinking Oligomers

NASA Technical Reports Server (NTRS)

Hinkley, Jeffrey A.; Young, Jennifer A.

1998-01-01

This report describes initial efforts to model the endlinking reaction of phenylethynyl-terminated oligomers. Several different molecular weights were simulated using the Bond Fluctuation Monte Carlo technique on a 20 x 20 x 20 unit lattice with periodic boundary conditions. After a monodisperse "melt" was equilibrated, chain ends were linked whenever they came within the allowed bond distance. Ends remained reactive throughout, so that multiple links were permitted. Even under these very liberal crosslinking assumptions, geometrical factors limited the degree of crosslinking. Average crosslink functionalities were 2.3 to 2.6; surprisingly, they did not depend strongly on the chain length. These results agreed well with the degrees of crosslinking inferred from experiment in a cured phenylethynyl-terminated polyimide oligomer.

Relativity of Scales: Application to AN Endo-Perspective of Temporal Structures

NASA Astrophysics Data System (ADS)

Nottale, Laurent; Timar, Pierre

The theory of scale relativity is an extension of the principle of relativity to scale transformations of the reference system, in a fractal geometry framework where coordinates become explicitly dependent on resolutions. Applied to an observer perspective, it means that the scales of length and of time, usually attributed to the observed object as being intrinsic to it, have actually no existence by themselves, since only the ratio between an external scale and an internal scale, which serves as unit, is meaningful. Oliver Sacks' observations on patients suffering from temporal and spatial distortions in Parkinson's and encephalitis lethargica disease offer a particularly relevant field of application for such a scale-relativistic view.

Mid-Infrared Long-Baseline Interferometry of the Symbiotic Mira Star RX Pup with the VLTI/MIDI Instrument

NASA Astrophysics Data System (ADS)

Driebe, T.; Hofmann, K.-H.; Ohnaka, K.; Schertl, D.; Weigelt, G.; Wittkowski, M.

We present mid-infrared long-baseline interferometric observations of the symbiotic Mira star RX Pup obtained with the VLTI/MIDI instrument in prism mode within the framework of the Science Demonstration Time (SDT) program in Feb. 2004. Four visibility measurements have been carried out using the unit telescopes UT2 and UT3, with projected baseline lengths ranging from 34.7 to 46.5 m.As we show by means of radiative transfer modelin with the code DUSTY [3], the wavelength dependence of the visibility and the N-band spectrum measured with MIDI can be interpreted as thesignature of a circumstellar dust shell which is dominated by silicate dust.

Context-free parsing with connectionist networks

NASA Astrophysics Data System (ADS)

Fanty, M. A.

1986-08-01

This paper presents a simple algorithm which converts any context-free grammar into a connectionist network which parses strings (of arbitrary but fixed maximum length) in the language defined by that grammar. The network is fast, O(n), and deterministicd. It consists of binary units which compute a simple function of their input. When the grammar is put in Chomsky normal form, O(n3) units needed to parse inputs of length up to n.

2002 Controls Design Challenge

NASA Technical Reports Server (NTRS)

Hess, Ronald A.; Vetter, T. K.; Wells, S. R.

2002-01-01

This document is intended to provide the specifications and requirements for a flight control system design challenge. The response to the challenge will involve documenting whether the particular design has met the stated requirements through analysis and computer simulation. The response should be written in the general format of a technical publication with corresponding length limits, e.g., an approximate maximum length of 45 units, with each full-size figure and double-spaced typewritten page constituting one unit.

Temporal and spatial variability of frost-free seasons in the Great Lakes region of the United States

Treesearch

Lejiang Yu; Shiyuan Zhong; Xindi Bian; Warren E. Heilman; Jeffrey A. Andresen

2014-01-01

The frequency and timing of frost events and the length of the growing season are critical limiting factors in many human and natural ecosystems. This study investigates the temporal and spatial variability of the date of last spring frost (LSF), the date of first fall frost (FFF), and the length of the frost-free season (FFS) in the Great Lakes region of the United...

Specialized Inpatient Psychiatry Units for Children with Autism and Developmental Disorders: A United States Survey

ERIC Educational Resources Information Center

Siegel, Matthew; Doyle, Kathleen; Chemelski, Bruce; Payne, David; Ellsworth, Beth; Harmon, Jamie; Robbins, Douglas; Milligan, Briana; Lubetsky, Martin

2012-01-01

A cross sectional survey was performed to obtain the characteristics of specialized inpatient psychiatry units exclusively serving children with autism and other developmental disorders in the United States. Identified units were surveyed on basic demographic characteristics, clinical challenges and therapeutic modalities. Average length of stay…

Transfusion of red blood cells: no impact on length of hospital stay in moderately anaemic parturients.

PubMed

Palo, R; Ahonen, J; Salo, H; Salmenperä, M; Krusius, T; Mäki, T

2007-05-01

In a search for information to improve decision making on red blood cell (RBC) transfusion, we examined the impact of RBC transfusion on the length of hospital stay for delivery in moderately anaemic women (haemoglobin, 7-10 g/dl). This was a retrospective, observational study covering 2 years (2002 and 2003), and included major blood-transfusing hospitals from four university and five central hospital districts managing 67.5% of Finnish in-hospital deliveries. The impact of the transfusion of 1-2 RBC units vs. no transfusion on the length of hospital stay was evaluated for three different haemoglobin levels: 7-7.9, 8-8.9 and 9-10 g/dl. Of the 1954 moderately anaemic mothers in hospital for delivery, 13.3% were transfused with RBC. The mean length of hospital stay was 5.2 days vs. the average Finnish hospital delivery stay of 3.5 days. No differences in stay were found between patients with comparable anaemia transfused with 1-2 RBC units or none (at the three haemoglobin levels: P= 0.50, P= 0.07 and P= 0.54, respectively). The final haemoglobin value was higher (P < 0.001) in transfused patients. The duration of admission for delivery in moderately anaemic parturients was longer than the average length of hospital stay in Finnish parturients. However, 1-2 RBC units had no impact on the length of stay, suggesting that unnecessary RBCs are transfused after delivery. Thus, transfusion practices in obstetrics are not always optimal.

Branch length mediates flower production and inflorescence architecture of Fouquieria splendens (ocotillo)

USGS Publications Warehouse

Bowers, Janice E.

2006-01-01

The capacity of individual branches to store water and fix carbon can have profound effects on inflorescence size and architecture, thus on floral display, pollination, and fecundity. Mixed regression was used to investigate the relation between branch length, a proxy for plant resources, and floral display of Fouquieria splendens (ocotillo), a woody, candelabraform shrub of wide distribution in arid North America. Long branches produced three times as many flowers as short branches, regardless of overall plant size. Long branches also had more complex panicles with more cymes and cyme types than short branches; thus, branch length also influenced inflorescence architecture. Within panicles, increasing the number of cymes by one unit added about two flowers, whereas increasing the number of cyme types by one unit added about 21 flowers. Because flower production is mediated by branch length, and because most plants have branches of various lengths, the floral display of individual plants necessarily encompasses a wide range of inflorescence size and structure. ?? Springer 2006.

A maximum pseudo-profile likelihood estimator for the Cox model under length-biased sampling

PubMed Central

Huang, Chiung-Yu; Qin, Jing; Follmann, Dean A.

2012-01-01

This paper considers semiparametric estimation of the Cox proportional hazards model for right-censored and length-biased data arising from prevalent sampling. To exploit the special structure of length-biased sampling, we propose a maximum pseudo-profile likelihood estimator, which can handle time-dependent covariates and is consistent under covariate-dependent censoring. Simulation studies show that the proposed estimator is more efficient than its competitors. A data analysis illustrates the methods and theory. PMID:23843659

The influence of severe malnutrition on rehabilitation in patients with severe head injury.

PubMed

Dénes, Zoltán

2004-10-07

The purpose of the study was to evaluate the consequences of severe malnutrition in patients with severe head injury during rehabilitation. The data were collected from medical records of patients admitted to the neurorehabilitation unit over the last 5 years. Twenty of 1850 patients had severe malnutrition, the body mass index (BMI) of these patients were under 15 (10-14) kg/m2. The majority of patients suffered traumatic brain damage (17/20). Thirteen patients arrived with percutaneous endoscopic gastrotomy /PEG, three nasogastric tube in 3 cases we placed PEG. The nutritional strategy included a high-calorie diet, by means of bolus feeding five times during the day, continuous feeding during the night; the daily intake target being more than 2500 kcal. During rehabilitation treatment the majority of patients (13/20) revealed weight gain with a rate of 0.5-2 kg/week. The following complications were treated during the rehabilitation phase: 20 pressure sores, 20 contractures, 11 urinal infections, 6 cases of pneumonia, 2 of purulent bronchitis, 6 of sepsis, 1 penoscrotal abscess, epidydymitis, and 1 case of purulent arthritis. The patients required total assistance at the time of admission. At discharge 10 patients remained completely dependent, 6 patients needed minimal assistance, and 4 patients could perform daily activities independently. The average length of stay in our unit was 78/6-150/days. Patients with head injury suffering from severe malnutrition exhibit serious complications at the time of admission as well as during rehabilitation treatment. The patients were very difficult to mobilize. The length of stay at the rehabilitation unit was 28 days longer when complicated by malnutrition, than head injuries showing normal nutritional status. These findings underline the importance of adequate nutrition in patients with head injury in both the acute ward and in the rehabilitation unit.

Early-Life Telomere Dynamics Differ between the Sexes and Predict Growth in the Barn Swallow (Hirundo rustica)

PubMed Central

Parolini, Marco; Romano, Andrea; Khoriauli, Lela; Nergadze, Solomon G.; Caprioli, Manuela; Rubolini, Diego; Santagostino, Marco; Saino, Nicola; Giulotto, Elena

2015-01-01

Telomeres are conserved DNA-protein structures at the termini of eukaryotic chromosomes which contribute to maintenance of genome integrity, and their shortening leads to cell senescence, with negative consequences for organismal functions. Because telomere erosion is influenced by extrinsic and endogenous factors, telomere dynamics may provide a mechanistic basis for evolutionary and physiological trade-offs. Yet, knowledge of fundamental aspects of telomere biology under natural selection regimes, including sex- and context-dependent variation in early-life, and the covariation between telomere dynamics and growth, is scant. In this study of barn swallows (Hirundo rustica) we investigated the sex-dependent telomere erosion during nestling period, and the covariation between relative telomere length and body and plumage growth. Finally, we tested whether any covariation between growth traits and relative telomere length depends on the social environment, as influenced by sibling sex ratio. Relative telomere length declined on average over the period of nestling maximal growth rate (between 7 and 16 days of age) and differently covaried with initial relative telomere length in either sex. The frequency distribution of changes in relative telomere length was bimodal, with most nestlings decreasing and some increasing relative telomere length, but none of the offspring traits predicted the a posteriori identified group to which individual nestlings belonged. Tail and wing length increased with relative telomere length, but more steeply in males than females, and this relationship held both at the within- and among-broods levels. Moreover, the increase in plumage phenotypic values was steeper when the sex ratio of an individual’s siblings was female-biased. Our study provides evidence for telomere shortening during early life according to subtly different dynamics in either sex. Furthermore, it shows that the positive covariation between growth and relative telomere length depends on sex as well as social environment, in terms of sibling sex ratio. PMID:26565632

Courgette Production: Pollination Demand, Supply, and Value.

PubMed

Knapp, Jessica L; Osborne, Juliet L

2017-10-01

Courgette (Cucurbita pepo L.) production in the United Kingdom is estimated to be worth £6.7 million. However, little is known about this crop's requirement for insect-mediated pollination (pollinator dependence) and if pollinator populations in a landscape are able to fulfil its pollination needs (pollination deficit). Consequently, pollination experiments were conducted over 2 yr to explore pollinator dependence and pollination deficit in field-grown courgette in the United Kingdom. Results showed that pollination increased yield by 39% and there was no evidence of pollination limitation on crop yield. This was evidenced by a surprisingly low pollination deficit (of just 3%) and no statistical difference in yield (length grown, circumference, and weight) between open- and hand-pollinated crops. Nonetheless, the high economic value of courgettes means that reducing even the small pollination deficit could still increase profit by ∼£166/ha. Interestingly, 56% of fruit was able to reach marketable size and shape without any pollination. Understanding a crop's requirement for pollinators can aid growers in their decision-making about what varieties and sites should be used. In doing so, they may increase their agricultural resilience and further their economic advantage. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

Ads' click-through rates predicting based on gated recurrent unit neural networks

NASA Astrophysics Data System (ADS)

Chen, Qiaohong; Guo, Zixuan; Dong, Wen; Jin, Lingzi

2018-05-01

In order to improve the effect of online advertising and to increase the revenue of advertising, the gated recurrent unit neural networks(GRU) model is used as the ads' click through rates(CTR) predicting. Combined with the characteristics of gated unit structure and the unique of time sequence in data, using BPTT algorithm to train the model. Furthermore, by optimizing the step length algorithm of the gated unit recurrent neural networks, making the model reach optimal point better and faster in less iterative rounds. The experiment results show that the model based on the gated recurrent unit neural networks and its optimization of step length algorithm has the better effect on the ads' CTR predicting, which helps advertisers, media and audience achieve a win-win and mutually beneficial situation in Three-Side Game.

Length-dependent thermal transport in one-dimensional self-assembly of planar π-conjugated molecules

NASA Astrophysics Data System (ADS)

Tang, Hao; Xiong, Yucheng; Zu, Fengshuo; Zhao, Yang; Wang, Xiaomeng; Fu, Qiang; Jie, Jiansheng; Yang, Juekuan; Xu, Dongyan

2016-06-01

This work reports a thermal transport study in quasi-one-dimensional organic nanostructures self-assembled from conjugated planar molecules via π-π interactions. Thermal resistances of single crystalline copper phthalocyanine (CuPc) and perylenetetracarboxylic diimide (PTCDI) nanoribbons are measured via a suspended thermal bridge method. We experimentally observed the deviation from the linear length dependence for the thermal resistance of single crystalline β-phase CuPc nanoribbons, indicating possible subdiffusion thermal transport. Interestingly, a gradual transition to the linear length dependence is observed with the increase of the lateral dimensions of CuPc nanoribbons. The measured thermal resistance of single crystalline CuPc nanoribbons shows an increasing trend with temperature. However, the trend of temperature dependence of thermal resistance is reversed after electron irradiation, i.e., decreasing with temperature, indicating that the single crystalline CuPc nanoribbons become `amorphous'. Similar behavior is also observed for PTCDI nanoribbons after electron irradiation, proving that the electron beam can induce amorphization of single crystalline self-assembled nanostructures of planar π-conjugated molecules. The measured thermal resistance of the `amorphous' CuPc nanoribbon demonstrates a roughly linear dependence on the nanoribbon length, suggesting that normal diffusion dominates thermal transport.This work reports a thermal transport study in quasi-one-dimensional organic nanostructures self-assembled from conjugated planar molecules via π-π interactions. Thermal resistances of single crystalline copper phthalocyanine (CuPc) and perylenetetracarboxylic diimide (PTCDI) nanoribbons are measured via a suspended thermal bridge method. We experimentally observed the deviation from the linear length dependence for the thermal resistance of single crystalline β-phase CuPc nanoribbons, indicating possible subdiffusion thermal transport. Interestingly, a gradual transition to the linear length dependence is observed with the increase of the lateral dimensions of CuPc nanoribbons. The measured thermal resistance of single crystalline CuPc nanoribbons shows an increasing trend with temperature. However, the trend of temperature dependence of thermal resistance is reversed after electron irradiation, i.e., decreasing with temperature, indicating that the single crystalline CuPc nanoribbons become `amorphous'. Similar behavior is also observed for PTCDI nanoribbons after electron irradiation, proving that the electron beam can induce amorphization of single crystalline self-assembled nanostructures of planar π-conjugated molecules. The measured thermal resistance of the `amorphous' CuPc nanoribbon demonstrates a roughly linear dependence on the nanoribbon length, suggesting that normal diffusion dominates thermal transport. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr09043a

Correlating the internal length in strain gradient plasticity theory with the microstructure of material

NASA Astrophysics Data System (ADS)

Zhao, Jianfeng; Zhang, Xu; Konstantinidis, Avraam A.; Kang, Guozheng

2015-06-01

The internal length is the governing parameter in strain gradient theories which among other things have been used successfully to interpret size effects at the microscale. Physically, the internal length is supposed to be related with the microstructure of the material and evolves during the deformation. Based on Taylor hardening law, we propose a power-law relationship to describe the evolution of the variable internal length with strain. Then, the classical Fleck-Hutchinson strain gradient theory is extended with a strain-dependent internal length, and the generalized Fleck-Hutchinson theory is confirmed here, by comparing our model predictions to recent experimental data on tension and torsion of thin wires with varying diameter and grain size. Our work suggests that the internal length is a configuration-dependent parameter, closely related to dislocation characteristics and grain size, as well as sample geometry when this affects either the underlying microstructure or the ductility of the material.

Descriptive Writing: A Thematic Unit.

ERIC Educational Resources Information Center

Smith, Joanna J.

This thematic unit for teaching descriptive writing is organized around 10 days of lesson plans. The unit begins by asking key questions about descriptive writing and providing information on grade level, ability level, number of lessons and length of classes, and prior knowledge students should have. It also offers a unit rationale and key…

Electrostatic contribution to the persistence length of a semiflexible dipolar chain.

PubMed

Podgornik, Rudi

2004-09-01

We investigate the electrostatic contribution to the persistence length of a semiflexible polymer chain whose segments interact via a screened Debye-Hückel dipolar interaction potential. We derive the expressions for the renormalized persistence length on the level of a 1/D-expansion method already successfully used in other contexts of polyelectrolye physics. We investigate different limiting forms of the renormalized persistence length of the dipolar chain and show that, in, general, it depends less strongly on the screening length than in the context of a monopolar chain. We show that for a dipolar chain the electrostatic persistence length in the same regime of the parameter phase space as the original Odijk-Skolnick-Fixman (OSF) form for a monopolar chain depends logarithmically on the screening length rather than quadratically. This can be understood solely on the basis of a swifter decay of the dipolar interactions with separation compared to the monopolar electrostatic interactions. We comment also on the general contribution of higher multipoles to the electrostatic renormalization of the bending rigidity.

Mechanical properties of kinked silicon nanowires

NASA Astrophysics Data System (ADS)

Jing, Yuhang; Zhang, Chuan; Liu, Yingzhi; Guo, Licheng; Meng, Qingyuan

2015-04-01

Molecular dynamics simulations are used to investigate the mechanical properties of KSiNWs. Our results show that KSiNWs have a much larger fracture strain compared to straight SiNWs. The effects of the periodic length of KSiNWs with symmetric arms and the arm length of the KSiNW with asymmetric arms on the mechanical properties of KSiNWs are studied. The fracture stress of KSiNWs decrease as the periodic length increases. However, the fracture strain of KSiNWs is not dependent on the short periodic length and the fracture strain of KSiNWs will abruptly increase to very large value and then vary slightly as the periodic length increases. In addition, the fracture stress is not dependent on arm length while the fracture strain monotonically increases as the arm length increases. We also investigate the fracture process of KSiNWs. The results in this paper suggest that the KSiNWs with larger fracture strain can be a promising anode materials in high performance Li-ion batteries.

Turbulent flows over superhydrophobic surfaces with shear-dependent slip length

NASA Astrophysics Data System (ADS)

Khosh Aghdam, Sohrab; Seddighi, Mehdi; Ricco, Pierre

2015-11-01

Motivated by recent experimental evidence, shear-dependent slip length superhydrophobic surfaces are studied. Lyapunov stability analysis is applied in a 3D turbulent channel flow and extended to the shear-dependent slip-length case. The feedback law extracted is recognized for the first time to coincide with the constant-slip-length model widely used in simulations of hydrophobic surfaces. The condition for the slip parameters is found to be consistent with the experimental data and with values from DNS. The theoretical approach by Fukagata (PoF 18.5: 051703) is employed to model the drag-reduction effect engendered by the shear-dependent slip-length surfaces. The estimated drag-reduction values are in very good agreement with our DNS data. For slip parameters and flow conditions which are potentially realizable in the lab, the maximum computed drag reduction reaches 50%. The power spent by the turbulent flow on the walls is computed, thereby recognizing the hydrophobic surfaces as a passive-absorbing drag-reduction method, as opposed to geometrically-modifying techniques that do not consume energy, e.g. riblets, hence named passive-neutral. The flow is investigated by visualizations, statistical analysis of vorticity and strain rates, and quadrants of the Reynolds stresses. Part of this work was funded by Airbus Group. Simulations were performed on the ARCHER Supercomputer (UKTC Grant).

76 FR 22725 - Cut-to-Length Carbon Steel Plate From India, Indonesia, Italy, Japan, and Korea; Scheduling of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-22

... Review)] Cut-to-Length Carbon Steel Plate From India, Indonesia, Italy, Japan, and Korea; Scheduling of...-Length Carbon Steel Plate From India, Indonesia, Italy, Japan, and Korea AGENCY: United States... from India, Indonesia, Italy, and Korea and/or therevocation of the antidumping duty orders on cut-to...

Maximizing the Functional Status of Geriatric Patients in an Acute Community Hospital Setting.

ERIC Educational Resources Information Center

Meissner, Paul; And Others

1989-01-01

Compared patients (N=103) admitted to inpatient geriatric care unit focusing on restoration of functional status to control-unit patients (N=75). Found greater improvement in basic functional capabilities of study-unit than control-unit patients. Found mixed picture when length of stay and total charges of study- and control-unit patients were…

The length and time scales of water's glass transitions

NASA Astrophysics Data System (ADS)

Limmer, David T.

2014-06-01

Using a general model for the equilibrium dynamics of supercooled liquids, I compute from molecular properties the emergent length and time scales that govern the nonequilibrium relaxation behavior of amorphous ice prepared by rapid cooling. Upon cooling, the liquid water falls out of equilibrium whereby the temperature dependence of its relaxation time is predicted to change from super-Arrhenius to Arrhenius. A consequence of this crossover is that the location of the apparent glass transition temperature depends logarithmically on cooling rate. Accompanying vitrification is the emergence of a dynamical length-scale, the size of which depends on the cooling rate and varies between angstroms and tens of nanometers. While this protocol dependence clarifies a number of previous experimental observations for amorphous ice, the arguments are general and can be extended to other glass forming liquids.

The length and time scales of water's glass transitions.

PubMed

Limmer, David T

2014-06-07

Using a general model for the equilibrium dynamics of supercooled liquids, I compute from molecular properties the emergent length and time scales that govern the nonequilibrium relaxation behavior of amorphous ice prepared by rapid cooling. Upon cooling, the liquid water falls out of equilibrium whereby the temperature dependence of its relaxation time is predicted to change from super-Arrhenius to Arrhenius. A consequence of this crossover is that the location of the apparent glass transition temperature depends logarithmically on cooling rate. Accompanying vitrification is the emergence of a dynamical length-scale, the size of which depends on the cooling rate and varies between angstroms and tens of nanometers. While this protocol dependence clarifies a number of previous experimental observations for amorphous ice, the arguments are general and can be extended to other glass forming liquids.

Length divergence of the lattice thermal conductivity in suspended graphene nanoribbons

NASA Astrophysics Data System (ADS)

Majee, Arnab K.; Aksamija, Zlatan

2016-06-01

Thermal properties of graphene have attracted much attention, culminating in a recent measurement of its length dependence in ribbons up to 9 μ m long. In this paper, we use the improved Callaway model to solve the phonon Boltzmann transport equation while capturing both the resistive (umklapp, isotope, and edge roughness) and nonresistive (normal) contributions. We show that for lengths smaller than 100 μ m , scaling the ribbon length while keeping the width constant leads to a logarithmic divergence of thermal conductivity. The length dependence is driven primarily by a ballistic-to-diffusive transition in the in-plane (LA and TA) branches, while in the hydrodynamic regime when 10 μ m 100 μ m due to the coupling between in-plane and flexural modes. This coupling leads to renormalization of ZA phonon dispersion in the long-wavelength range, preventing further divergence of thermal conductivity. We also uncover a strong dependence on sample width, which we attribute to the interplay between nonresistive normal and diffusive edge scattering in the Poisseuille flow regime. We conclude that normal processes play a crucial role in the length and width dependence of thermal transport in graphene in the hydrodynamic regime and dictate the relative in-plane (LA+TA) to out-of-plane (ZA) contribution to transport.

Techniques for estimating streamflow characteristics in the Eastern and Interior coal provinces of the United States

USGS Publications Warehouse

Wetzel, Kim L.; Bettandorff, J.M.

1986-01-01

Techniques are presented for estimating various streamflow characteristics, such as peak flows, mean monthly and annual flows, flow durations, and flow volumes, at ungaged sites on unregulated streams in the Eastern Coal region. Streamflow data and basin characteristics for 629 gaging stations were used to develop multiple-linear-regression equations. Separate equations were developed for the Eastern and Interior Coal Provinces. Drainage area is an independent variable common to all equations. Other variables needed, depending on the streamflow characteristic, are mean annual precipitation, mean basin elevation, main channel length, basin storage, main channel slope, and forest cover. A ratio of the observed 50- to 90-percent flow durations was used in the development of relations to estimate low-flow frequencies in the Eastern Coal Province. Relations to estimate low flows in the Interior Coal Province are not presented because the standard errors were greater than 0.7500 log units and were considered to be of poor reliability.

Molecular weight-dependent degradation of D-lactate-containing polyesters by polyhydroxyalkanoate depolymerases from Variovorax sp. C34 and Alcaligenes faecalis T1.

PubMed

Sun, Jian; Matsumoto, Ken'ichiro; Tabata, Yuta; Kadoya, Ryosuke; Ooi, Toshihiko; Abe, Hideki; Taguchi, Seiichi

2015-11-01

Polyhydroxyalkanoate depolymerase derived from Variovorax sp. C34 (PhaZVs) was identified as the first enzyme that is capable of degrading isotactic P[67 mol% (R)-lactate(LA)-co-(R)-3-hydroxybutyrate(3HB)] [P(D-LA-co-D-3HB)]. This study aimed at analyzing the monomer sequence specificity of PhaZVs for hydrolyzing P(LA-co-3HB) in comparison with a P(3HB) depolymerase from Alcaligenes faecalis T1 (PhaZAf) that did not degrade the same copolymer. Degradation of P(LA-co-3HB) by action of PhaZVs generated dimers, 3HB-3HB, 3HB-LA, LA-3HB, and LA-LA, and the monomers, suggesting that PhaZVs cleaved the linkages between LA and 3HB units and between LA units. To provide a direct evidence for the hydrolysis of these sequences, the synthetic methyl trimers, 3HB-3HB-3HB, LA-LA-3HB, LA-3HB-LA, and 3HB-LA-LA, were treated with the PhaZs. Unexpectedly, not only PhaZVs but also PhaZAf hydrolyzed all of these substrates, namely PhaZAf also cleaved LA-LA linkage. Considering the fact that both PhaZs did not degrade P[(R)-LA] (PDLA) homopolymer, the cleavage capability of LA-LA linkage by PhaZs was supposed to depend on the length of the LA-clustering region in the polymer chain. To test this hypothesis, PDLA oligomers (6 to 40 mer) were subjected to the PhaZ assay, revealing that there was an inverse relationship between molecular weight of the substrates and their hydrolysis efficiency. Moreover, PhaZVs exhibited the degrading activity toward significantly longer PDLA oligomers compared to PhaZAf. Therefore, the cleaving capability of PhaZs used here toward the D-LA-based polymers containing the LA-clustering region was strongly associated with the substrate length, rather than the monomer sequence specificity of the enzyme.

Identification of Simple Sequence Repeats in Chloroplast Genomes of Magnoliids Through Bioinformatics Approach.

PubMed

Srivastava, Deepika; Shanker, Asheesh

2016-12-01

Basal angiosperms or Magnoliids is an important clade of commercially important plants which mainly include spices and edible fruits. In this study, 17 chloroplast genome sequences belonging to clade Magnoliids were screened for the identification of chloroplast simple sequence repeats (cpSSRs). Simple sequence repeats or microsatellites are short stretches of DNA up to 1-6 base pair in length. These repeats are ubiquitous and play important role in the development of molecular markers and to study the mapping of traits of economic, medical or ecological interest. A total of 479 SSRs were detected, showing average density of 1 SSR/6.91 kb. Depending on the repeat units, the length of SSRs ranged from 12 to 24 bp for mono-, 12 to 18 bp for di-, 12 to 26 bp for tri-, 12 to 24 bp for tetra-, 15 bp for penta- and 18 bp for hexanucleotide repeats. Mononucleotide repeats were the most frequent (207, 43.21 %) followed by tetranucleotide repeats (130, 27.13 %). Penta- and hexanucleotide repeats were least frequent or absent in these chloroplast genomes.

Characterizing Spatial Organization of Cell Surface Receptors in Human Breast Cancer with STORM

NASA Astrophysics Data System (ADS)

Lyall, Evan; Chapman, Matthew R.; Sohn, Lydia L.

2012-02-01

Regulation and control of complex biological functions are dependent upon spatial organization of biological structures at many different length scales. For instance Eph receptors and their ephrin ligands bind when opposing cells come into contact during development, resulting in spatial organizational changes on the nanometer scale that lead to changes on the macro scale, in a process known as organ morphogenesis. One technique able to probe this important spatial organization at both the nanometer and micrometer length scales, including at cell-cell junctions, is stochastic optical reconstruction microscopy (STORM). STORM is a technique that localizes individual fluorophores based on the centroids of their point spread functions and then reconstructs a composite image to produce super resolved structure. We have applied STORM to study spatial organization of the cell surface of human breast cancer cells, specifically the organization of tyrosine kinase receptors and chemokine receptors. A better characterization of spatial organization of breast cancer cell surface proteins is necessary to fully understand the tumorigenisis pathways in the most common malignancy in United States women.

Evaluation of a Progressive Mobility Protocol in Postoperative Cardiothoracic Surgical Patients.

PubMed

Floyd, Shawn; Craig, Sarah W; Topley, Darla; Tullmann, Dorothy

2016-01-01

Cardiothoracic surgical patients are at high risk for complications related to immobility, such as increased intensive care and hospital length of stay, intensive care unit readmission, pressure ulcer development, and deep vein thrombosis/pulmonary embolus. A progressive mobility protocol was started in the thoracic cardiovascular intensive care unit in a rural academic medical center. The purpose of the progressive mobility protocol was to increase mobilization of postoperative patients and decrease complications related to immobility in this unique patient population. A matched-pairs design was used to compare a randomly selected sample of the preintervention group (n = 30) to a matched postintervention group (n = 30). The analysis compared outcomes including intensive care unit and hospital length of stay, intensive care unit readmission occurrence, pressure ulcer prevalence, and deep vein thrombosis/pulmonary embolism prevalence between the 2 groups. Although this comparison does not achieve statistical significance (P < .05) for any of the outcomes measured, it does show clinical significance in a reduction in hospital length of stay, intensive care unit days, in intensive care unit readmission rate, and a decline in pressure ulcer prevalence, which is the overall goal of progressive mobility. This study has implications for nursing, hospital administration, and therapy services with regard to staffing and cost savings related to fewer complications of immobility. Future studies with a larger sample size and other populations are warranted.

Implementation of a flow-dependent background error correlation length scale formulation in the NEMOVAR OSTIA system

NASA Astrophysics Data System (ADS)

Fiedler, Emma; Mao, Chongyuan; Good, Simon; Waters, Jennifer; Martin, Matthew

2017-04-01

OSTIA is the Met Office's Operational Sea Surface Temperature (SST) and Ice Analysis system, which produces L4 (globally complete, gridded) analyses on a daily basis. Work is currently being undertaken to replace the original OI (Optimal Interpolation) data assimilation scheme with NEMOVAR, a 3D-Var data assimilation method developed for use with the NEMO ocean model. A dual background error correlation length scale formulation is used for SST in OSTIA, as implemented in NEMOVAR. Short and long length scales are combined according to the ratio of the decomposition of the background error variances into short and long spatial correlations. The pre-defined background error variances vary spatially and seasonally, but not on shorter time-scales. If the derived length scales applied to the daily analysis are too long, SST features may be smoothed out. Therefore a flow-dependent component to determining the effective length scale has also been developed. The total horizontal gradient of the background SST field is used to identify regions where the length scale should be shortened. These methods together have led to an improvement in the resolution of SST features compared to the previous OI analysis system, without the introduction of spurious noise. This presentation will show validation results for feature resolution in OSTIA using the OI scheme, the dual length scale NEMOVAR scheme, and the flow-dependent implementation.

Predicting Length of Stay in Intensive Care Units after Cardiac Surgery: Comparison of Artificial Neural Networks and Adaptive Neuro-fuzzy System.

PubMed

Maharlou, Hamidreza; Niakan Kalhori, Sharareh R; Shahbazi, Shahrbanoo; Ravangard, Ramin

2018-04-01

Accurate prediction of patients' length of stay is highly important. This study compared the performance of artificial neural network and adaptive neuro-fuzzy system algorithms to predict patients' length of stay in intensive care units (ICU) after cardiac surgery. A cross-sectional, analytical, and applied study was conducted. The required data were collected from 311 cardiac patients admitted to intensive care units after surgery at three hospitals of Shiraz, Iran, through a non-random convenience sampling method during the second quarter of 2016. Following the initial processing of influential factors, models were created and evaluated. The results showed that the adaptive neuro-fuzzy algorithm (with mean squared error [MSE] = 7 and R = 0.88) resulted in the creation of a more precise model than the artificial neural network (with MSE = 21 and R = 0.60). The adaptive neuro-fuzzy algorithm produces a more accurate model as it applies both the capabilities of a neural network architecture and experts' knowledge as a hybrid algorithm. It identifies nonlinear components, yielding remarkable results for prediction the length of stay, which is a useful calculation output to support ICU management, enabling higher quality of administration and cost reduction.

Relational experiences of partnered Japanese immigrant women with affect disorders.

PubMed

Kozuki, Yoriko; Kennedy, Michael G; Tsai, Jenny Hsin-Chun

2006-03-01

This paper reports the findings of a study that explored characteristics of relationships of Japanese immigrant women partnered both intraculturally and interculturally, and analysed the role of Japanese culture in these relationships. Immigration can cause shifts in interpersonal structures with partners. When there are large discrepancies in gender roles and communication styles between the original and host cultures, the psychological impact on both partners may be significant. However, currently no empirical data are available to support this assumption. Ten cases selected from the 68 medical records of Japanese-speaking women seen at a mental health clinic from September 2001 to September 2004 were analysed. All of the 10 women met DSM IV-TR criteria of major depressive disorder and were taking antidepressants. Half of the 10 women were in intimate intercultural partnered relationships and the remainder of the matched cases were in intracultural relationships at the time of treatment. The two cohorts were matched in age (36.2 and 43.2 years), length of stay in the United States of America (12 and 16.2 years), and length of treatment (1.2 and 1 years). The length of time of the sample in individual psychodynamic psychotherapy ranged from 20 to 317 hours, depending on the intensity of therapy. Inductive data analysis revealed two themes: (1) Lack of awareness of differences in culturally bound communication by Japanese women in intercultural partnerships; (2) Lack of individuality in Japanese women in intracultural partnerships. Neither group appeared to consider relational aspects of partnership, or to make efforts to improve direct communication with their partners. The influence of Japanese culture on gender role and communication styles functions contrary to the mainstream Western culture of the United States of America. In the future, interpersonal elements of cultural differences between host and original cultures in immigration should be considered in research related to immigrants' mental health. This approach should lead to effective interventions to facilitate mental health among immigrants, and regardless of purposes of immigration or length of stay in a psychosocially foreign environment.

Randomised trial of glutamine, selenium, or both, to supplement parenteral nutrition for critically ill patients.

PubMed

Andrews, Peter J D; Avenell, Alison; Noble, David W; Campbell, Marion K; Croal, Bernard L; Simpson, William G; Vale, Luke D; Battison, Claire G; Jenkinson, David J; Cook, Jonathan A

2011-03-17

To determine whether inclusion of glutamine, selenium, or both in a standard isonitrogenous, isocaloric preparation of parenteral nutrition influenced new infections and mortality among critically ill patients. Randomised, double blinded, factorial, controlled trial. Level 2 and 3 (or combined) critical care units in Scotland. All 22 units were invited, and 10 participated. 502 adults in intensive care units and high dependency units for ≥ 48 hours, with gastrointestinal failure and requiring parenteral nutrition. Parenteral glutamine (20.2 g/day) or selenium (500 μg/day), or both, for up to seven days. Primary outcomes were participants with new infections in the first 14 days and mortality. An intention to treat analysis and a prespecified analysis of patients who received ≥ 5 days of the trial intervention are presented. Secondary outcomes included critical care unit and acute hospital lengths of stay, days of antibiotic use, and modified SOFA (Sepsis-related Organ Failure Assessment) score. Selenium supplementation did not significantly affect patients developing a new infection (126/251 v 139/251, odds ratio 0.81 (95% CI 0.57 to 1.15)), except for those who had received ≥ 5 days of supplementation (odds ratio 0.53 (0.30 to 0.93)). There was no overall effect of glutamine on new infections (134/250 v 131/252, odds ratio 1.07 (0.75 to 1.53)), even if patients received ≥ 5 days of supplementation (odds ratio 0.99 (0.56 to 1.75)). Six month mortality was not significantly different for selenium (107/251 v 114/251, odds ratio 0.89 (0.62 to 1.29)) or glutamine (115/250 v 106/252, 1.18 (0.82 to 1.70)). Length of stay, days of antibiotic use, and modified SOFA score were not significantly affected by selenium or glutamine supplementation. The primary (intention to treat) analysis showed no effect on new infections or on mortality when parenteral nutrition was supplemented with glutamine or selenium. Patients who received parenteral nutrition supplemented with selenium for ≥ 5 days did show a reduction in new infections. This finding requires confirmation. Trial registration Current Controlled Trials ISRCTN87144826.

Pennies (Nickels and Dimes) from Heaven. Unit Plans.

ERIC Educational Resources Information Center

United States Mint (Dept. of Treasury), Washington, DC.

This unit of study walks early elementary students through the basics of counting and using the smallest U.S. coin denominations (penny, nickel, and dime). The unit provides keywords; recommends subject areas and approximate length of time; poses an essential question or problem; provides a unit introduction; outlines five individual lessons ((1)…

Creative Coin Combinations. Unit Plans.

ERIC Educational Resources Information Center

United States Mint (Dept. of Treasury), Washington, DC.

This unit of study for grades K-2 focuses on counting coins and coin equivalencies up to 50 cents, making use of a literature connection. The unit provides key words; recommends subject areas and approximate length of time; poses an essential question or problem; provides a unit introduction; notes four individual lessons ((1) For Sale!; (2)…

Exhaust gas purification system for lean burn engine

DOEpatents

Haines, Leland Milburn

2002-02-19

An exhaust gas purification system for a lean burn engine includes a thermal mass unit and a NO.sub.x conversion catalyst unit downstream of the thermal mass unit. The NO.sub.x conversion catalyst unit includes at least one catalyst section. Each catalyst section includes a catalytic layer for converting NO.sub.x coupled to a heat exchanger. The heat exchanger portion of the catalyst section acts to maintain the catalytic layer substantially at a desired temperature and cools the exhaust gas flowing from the catalytic layer into the next catalytic section in the series. In a further aspect of the invention, the exhaust gas purification system includes a dual length exhaust pipe upstream of the NO.sub.x conversion catalyst unit. The dual length exhaust pipe includes a second heat exchanger which functions to maintain the temperature of the exhaust gas flowing into the thermal mass downstream near a desired average temperature.

75 FR 22384 - Ball Bearings and Parts Thereof From France, Germany, Italy, Japan, and the United Kingdom...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-28

... orders cover all the subject bearings and parts thereof (inner race, outer race, cage, rollers, balls... producer, i.e., sales were made at arm's-length prices. See 19 CFR 351.403(c). We excluded from our... arm's-length prices. To test whether these sales were made at arm's-length prices, we compared the...

Leaf vein length per unit area is not intrinsically dependent on image magnification: avoiding measurement artifacts for accuracy and precision.

PubMed

Sack, Lawren; Caringella, Marissa; Scoffoni, Christine; Mason, Chase; Rawls, Michael; Markesteijn, Lars; Poorter, Lourens

2014-10-01

Leaf vein length per unit leaf area (VLA; also known as vein density) is an important determinant of water and sugar transport, photosynthetic function, and biomechanical support. A range of software methods are in use to visualize and measure vein systems in cleared leaf images; typically, users locate veins by digital tracing, but recent articles introduced software by which users can locate veins using thresholding (i.e. based on the contrasting of veins in the image). Based on the use of this method, a recent study argued against the existence of a fixed VLA value for a given leaf, proposing instead that VLA increases with the magnification of the image due to intrinsic properties of the vein system, and recommended that future measurements use a common, low image magnification for measurements. We tested these claims with new measurements using the software LEAFGUI in comparison with digital tracing using ImageJ software. We found that the apparent increase of VLA with magnification was an artifact of (1) using low-quality and low-magnification images and (2) errors in the algorithms of LEAFGUI. Given the use of images of sufficient magnification and quality, and analysis with error-free software, the VLA can be measured precisely and accurately. These findings point to important principles for improving the quantity and quality of important information gathered from leaf vein systems. © 2014 American Society of Plant Biologists. All Rights Reserved.

Changing structure and resources in a rheumatology combined unit during 1977-1999.

PubMed

Kvalvik, A G; Larsen, S; Aadland, H A; Høyeraal, H M

2007-01-01

The aim was to study the changing structure and resources in a rheumatism hospital during the period 1977-1999 when rheumatology care was decentralized and new treatment strategies were introduced. Data on hospital management and production were retrieved retrospectively. The number of beds was stepwise reduced from 133 to 44 and the average length of stay declined from 48 to 16 days. The combined unit and multidisciplinary team organization was kept, ensuring the combined effort of rheumatologists, rheumasurgeons, registered nurses, physiotherapists, occupational therapists, and social workers. One-third of the total staff was rheumateam members in 1977 compared to one-half in 1999. The proportions of physicians and registered nurses increased while the proportion of physiotherapists was stable. The number of discharges remained relatively unchanged and the number of outpatient consultations increased. Inflammatory rheumatic diseases remained the largest diagnostic group of in- and outpatients. Hospitalized care was received primarily by patients with arthritis and spondylitis. Patients with vasculitis and diffuse disorders of connective tissue accounted for an increasing proportion of the outpatient clinic production. Surgical procedures became more prevalent. Since 1995 approximately 50 large joint replacements have been performed annually. The length of stay declined and patient care was shifted towards the outpatient clinic. The multidisciplinary team was strengthened. More resources were dedicated to physician-led and nurse-dependent procedures, but physiotherapy and rehabilitation remained part of inpatient care throughout the period. The expertise concentrated on inflammatory rheumatic disorders. The modesty of the large joint replacement caseload may challenge decentralized care.

Evaluation of predicted Medfly ( Ceratitis capitata) quarantine length in the United States utilizing degree-day and agent-based models.

PubMed

Collier, Travis; Manoukis, Nicholas

2017-01-01

Invasions by pest insects pose a significant threat to agriculture worldwide. In the case of Ceratitis capitata incursions on the US mainland, where it is not officially established, repeated detections are followed by quarantines and treatments to eliminate the invading population. However, it is difficult to accurately set quarantine duration because non-detection may not mean the pest is eliminated. Most programs extend quarantine lengths past the last fly detection by calculating the amount of time required for 3 generations to elapse under a thermal unit accumulation development model ("degree day"). A newer approach is to use an Agent-Based Simulation (ABS) to explicitly simulate population demographics and elimination. Here, predicted quarantine lengths for 11 sites in the continental United States are evaluated using both approaches. Results indicate a strong seasonality in quarantine length, with longer predictions in the second half of the year compared with the first; this pattern is more extreme in degree day predictions compared with ABS. Geographically, quarantine lengths increased with latitude, though this was less pronounced under the ABS. Variation in quarantine lengths for particular times and places was dramatically larger for degree day than ABS, generally spiking in the middle of the year for degree day and peaking in second half of the year for ABS. Analysis of 34 C. capitata quarantines from 1975 to 2017 in California shows that, for all but two, quarantines were started in the second half of the year, when degree day quarantine lengths are longest and have the highest uncertainty. For a set of hypothetical outbreaks based on these historical quarantines, the ABS produced significantly shorter quarantines than degree day calculations. Overall, ABS quarantine lengths were more consistent than degree day predictions, avoided unrealistically long values, and captured effects of rare events such as cold snaps.

Does a specialist unit improve outcomes for hospitalized patients with Parkinson's disease?

PubMed Central

Skelly, Rob; Brown, Lisa; Fakis, Apostolos; Kimber, Lindsey; Downes, Charlotte; Lindop, Fiona; Johnson, Clare; Bartliff, Caroline; Bajaj, Nin

2014-01-01

Objective Suboptimal management of Parkinson's disease (PD) medication in hospital may lead to avoidable complications. We introduced an in-patient PD unit for those admitted urgently with general medical problems. We explored the effect of the unit on medication management, length of stay and patient experience. Methods We conducted a single-center prospective feasibility study. The unit's core features were defined following consultation with patients and professionals: specially trained staff, ready availability of PD drugs, guidelines, and care led by a geriatrician with specialty PD training. Mandatory staff training comprised four 1 h sessions: PD symptoms; medications; therapy; communication and swallowing. Most medication was prescribed using an electronic Prescribing and Administration system (iSOFT) which provided accurate data on time of administration. We compared patient outcomes before and after introduction of the unit. Results The general ward care (n = 20) and the Specialist Parkinson's Unit care (n = 24) groups had similar baseline characteristics. On the specialist unit: less Parkinson's medication was omitted (13% vs 20%, p < 0.001); of the medication that was given, more was given on time (64% vs 50%, p < 0.001); median length of stay was shorter (9 days vs 13 days, p = 0.043) and patients' experience of care was better (p = 0.01). Discussion If replicated and generalizable to other hospitals, reductions in length of stay would lead to significant cost savings. The apparent improved outcomes with Parkinson's unit care merit further investigation. We hope to test the hypothesis that specialized units are cost-effective and improve patient care using a randomized controlled trial design. PMID:25264022

Bond Length Dependence on Quantum States as Shown by Spectroscopy

ERIC Educational Resources Information Center

Lim, Kieran F.

2005-01-01

A discussion on how a spreadsheet simulation of linear-molecular spectra could be used to explore the dependence of rotational band spacing and contours on average bond lengths in the initial and final quantum states is presented. The simulation of hydrogen chloride IR, iodine UV-vis, and nitrogen UV-vis spectra clearly show whether the average…

INTERPRETATION OF THE CANCER RESPONSE TO POTENTIAL RENTAL CARCINOGENS IN THE TSC2 KNOCKOUT (EKER) RAT IS DEPENDENT ON LENGTH OF TREATMENT.

EPA Science Inventory

INTERPRETATION OF THE CANCER RESPONSE TO POTENTIAL RENAL CARCINOGENS IN THE TSC2 KNOCKOUT (EKER) RAT IS DEPENDENT ON LENGTH OF TREATMENT.

Genetically increasing the function of oncogenes or knocking out the function of a tumor supressor gene has dramatically increased the...

A probabilistic tornado wind hazard model for the continental United States

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

Hossain, Q; Kimball, J; Mensing, R

A probabilistic tornado wind hazard model for the continental United States (CONUS) is described. The model incorporates both aleatory (random) and epistemic uncertainties associated with quantifying the tornado wind hazard parameters. The temporal occurrences of tornadoes within the continental United States (CONUS) is assumed to be a Poisson process. A spatial distribution of tornado touchdown locations is developed empirically based on the observed historical events within the CONUS. The hazard model is an aerial probability model that takes into consideration the size and orientation of the facility, the length and width of the tornado damage area (idealized as a rectanglemore » and dependent on the tornado intensity scale), wind speed variation within the damage area, tornado intensity classification errors (i.e.,errors in assigning a Fujita intensity scale based on surveyed damage), and the tornado path direction. Epistemic uncertainties in describing the distributions of the aleatory variables are accounted for by using more than one distribution model to describe aleatory variations. The epistemic uncertainties are based on inputs from a panel of experts. A computer program, TORNADO, has been developed incorporating this model; features of this program are also presented.« less

New two-tier low pressure turbine for heavy duty steam turbines

NASA Astrophysics Data System (ADS)

Zaryankin, A. E.; Rogalev, A. N.; Osipov, S. K.; Bychkov, N. M.

2017-11-01

Among factors characterising steam turbine units of power plants, a specific metal content which value decreases inversely to turbine power is of substantive importance. In turn, their maximum power depends on the capacity of low pressure turbines. It is traditionally managed to increase either by installation of larger number of low pressure turbines or by lengthening the exhaust blades. It is worth noting that the above-mentioned methods have some technical restrictions by the number of rotors to be connected. Currently some works aimed at solving the stated technical problems appear in the literature for the purpose of increasing the unit power of turbomachines, for example, by using exhaust blades with the length of 1 500 mm and longer. However, it is to be understood that increasing the exhaust area of turbomachine only by lengthening exhaust blades cannot provide a cost-effective and reliable work of the turbine flow part. Here new problems appear: losses rise abruptly due to the stage fan-out, the turbomachine dimensions increase, etc. In this connection, an issue of development of new, technically implementable ways of turbo-units power increase is very acute today.

Length-dependent transport in molecular junctions based on SAMs of alkanethiols and alkanedithiols: effect of metal work function and applied bias on tunneling efficiency and contact resistance.

PubMed

Engelkes, Vincent B; Beebe, Jeremy M; Frisbie, C Daniel

2004-11-03

Nanoscopic tunnel junctions were formed by contacting Au-, Pt-, or Ag-coated atomic force microscopy (AFM) tips to self-assembled monolayers (SAMs) of alkanethiol or alkanedithiol molecules on polycrystalline Au, Pt, or Ag substrates. Current-voltage traces exhibited sigmoidal behavior and an exponential attenuation with molecular length, characteristic of nonresonant tunneling. The length-dependent decay parameter, beta, was found to be approximately 1.1 per carbon atom (C(-1)) or 0.88 A(-)(1) and was independent of applied bias (over a voltage range of +/-1.5 V) and electrode work function. In contrast, the contact resistance, R(0), extrapolated from resistance versus molecular length plots showed a notable decrease with both applied bias and increasing electrode work function. The doubly bound alkanedithiol junctions were observed to have a contact resistance approximately 1 to 2 orders of magnitude lower than the singly bound alkanethiol junctions. However, both alkanethiol and dithiol junctions exhibited the same length dependence (beta value). The resistance versus length data were also used to calculate transmission values for each type of contact (e.g., Au-S-C, Au/CH(3), etc.) and the transmission per C-C bond (T(C)(-)()(C)).

Thixotropy and Rheopexy of Muscle Fibers Probed Using Sinusoidal Oscillations

PubMed Central

Altman, David; Minozzo, Fabio C.; Rassier, Dilson E.

2015-01-01

Length changes of muscle fibers have previously been shown to result in a temporary reduction in fiber stiffness that is referred to as thixotropy. Understanding the mechanism of this thixotropy is important to our understanding of muscle function since there are many instances in which muscle is subjected to repeated patterns of lengthening and shortening. By applying sinusoidal length changes to one end of single permeabilized muscle fibers and measuring the force response at the opposite end, we studied the history-dependent stiffness of both relaxed and activated muscle fibers. For length change oscillations greater than 1 Hz, we observed thixotropic behavior of activated fibers. Treatment of these fibers with EDTA and blebbistatin, which inhibits myosin-actin interactions, quashed this effect, suggesting that the mechanism of muscle fiber thixotropy is cross-bridge dependent. We modeled a half-sarcomere experiencing sinusoidal length changes, and our simulations suggest that thixotropy could arise from force-dependent cross-bridge kinetics. Surprisingly, we also observed that, for length change oscillations less than 1 Hz, the muscle fiber exhibited rheopexy. In other words, the stiffness of the fiber increased in response to the length changes. Blebbistatin and EDTA did not disrupt the rheopectic behavior, suggesting that a non-cross-bridge mechanism contributes to this phenomenon. PMID:25880774

Channel length dependence of negative-bias-illumination-stress in amorphous-indium-gallium-zinc-oxide thin-film transistors

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

Um, Jae Gwang; Mativenga, Mallory; Jang, Jin, E-mail: jjang@khu.ac.kr

2015-06-21

We have investigated the dependence of Negative-Bias-illumination-Stress (NBIS) upon channel length, in amorphous-indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs). The negative shift of the transfer characteristic associated with NBIS decreases for increasing channel length and is practically suppressed in devices with L = 100-μm. The effect is consistent with creation of donor defects, mainly in the channel regions adjacent to source and drain contacts. Excellent agreement with experiment has been obtained by an analytical treatment, approximating the distribution of donors in the active layer by a double exponential with characteristic length L{sub D} ∼ L{sub n} ∼ 10-μm, the latter being the electron diffusion length. The model alsomore » shows that a device with a non-uniform doping distribution along the active layer is in all equivalent, at low drain voltages, to a device with the same doping averaged over the active layer length. These results highlight a new aspect of the NBIS mechanism, that is, the dependence of the effect upon the relative magnitude of photogenerated holes and electrons, which is controlled by the device potential/band profile. They may also provide the basis for device design solutions to minimize NBIS.« less

Zonal Articular Cartilage Possesses Complex Mechanical Behavior Spanning Multiple Length Scales: Dependence on Chemical Heterogeneity, Anisotropy, and Microstructure

NASA Astrophysics Data System (ADS)

Wahlquist, Joseph A.

This work focused on characterizing the mechanical behavior of biological material in physiologically relevant conditions and at sub millimeter length scales. Elucidating the time, length scale, and directionally dependent mechanical behavior of cartilage and other biological materials is critical to adequately recapitulate native mechanosensory cues for cells, create computational models that mimic native tissue behavior, and assess disease progression. This work focused on three broad aspects of characterizing the mechanical behavior of articular cartilage. First, we sought to reveal the causes of time-dependent deformation and variation of mechanical properties with distance from the articular surface. Second, we investigated size dependence of mechanical properties. Finally, we examined material anisotropy of both the calcified and uncalcified tissues of the osteochondral interface. This research provides insight into how articular cartilage serves to support physiologic loads and simultaneously sustain chondrocyte viability.

Anomalous transport in fluid field with random waiting time depending on the preceding jump length

NASA Astrophysics Data System (ADS)

Zhang, Hong; Li, Guo-Hua

2016-11-01

Anomalous (or non-Fickian) transport behaviors of particles have been widely observed in complex porous media. To capture the energy-dependent characteristics of non-Fickian transport of a particle in flow fields, in the present paper a generalized continuous time random walk model whose waiting time probability distribution depends on the preceding jump length is introduced, and the corresponding master equation in Fourier-Laplace space for the distribution of particles is derived. As examples, two generalized advection-dispersion equations for Gaussian distribution and lévy flight with the probability density function of waiting time being quadratic dependent on the preceding jump length are obtained by applying the derived master equation. Project supported by the Foundation for Young Key Teachers of Chengdu University of Technology, China (Grant No. KYGG201414) and the Opening Foundation of Geomathematics Key Laboratory of Sichuan Province, China (Grant No. scsxdz2013009).

Co:MgF2 laser ablation of tissue: effect of wavelength on ablation threshold and thermal damage.

PubMed

Schomacker, K T; Domankevitz, Y; Flotte, T J; Deutsch, T F

1991-01-01

The wavelength dependence of the ablation threshold of a variety of tissues has been studied by using a tunable pulsed Co:MgF2 laser to determine how closely it tracks the optical absorption length of water. The Co:MgF2 laser was tuned between 1.81 and 2.14 microns, a wavelength region in which the absorption length varies by a decade. For soft tissues the ablation threshold tracks the optical absorption length; for bone there is little wavelength dependence, consistent with the low water content of bone. Thermal damage vs. wavelength was also studied for cornea and bone. Thermal damage to cornea has a weak wavelength dependence, while that to bone shows little wavelength dependence. Framing-camera pictures of the ablation of both cornea and liver show explosive removal of material, but differ as to the nature of the explosion.

Application of a single root-scale model to improve macroscopic modeling of root water uptake: focus on osmotic stress

NASA Astrophysics Data System (ADS)

Jorda, Helena; Perelman, Adi; Lazarovitch, Naftali; Vanderborght, Jan

2017-04-01

Root water uptake is a fundamental process in the hydrological cycle and it largely regulates the water balance in the soil vadose zone. Macroscopic stress functions are currently used to estimate the effect of salinity on root water uptake. These functions commonly assume stress to be a function of bulk salinity and of the plant sensitivity to osmotic stress expressed as the salinity at which transpiration is reduced by half or so called tolerance value. However, they fail to integrate additional relevant factors such as atmospheric conditions or root architectural traits. We conducted a comprehensive simulation study on a single root using a 3-D physically-based model that resolves flow and transport to individual root segments and that couples flow in the soil and root system. The effect of salt concentrations on root water uptake was accounted for by including osmotic water potential gradients between the solution at the soil root interface and the root xylem sap in the hydraulic gradient between the soil and root. A large set of factors were studied, namely, potential transpiration rate and dynamics, root length density (RLD), irrigation water quality and irrigation frequency, and leaching fraction. Results were fitted to the macroscopic function developed by van Genuchten and Hoffman (1984) and the dependency of osmotic stress and the fitted macroscopic parameters on the studied factors was evaluated. Osmotic stress was found to be highly dependent on RLD. Low RLDs result in a larger stress to the plant due to high evaporative demand per root length unit. In addition, osmotic stress was positively correlated to potential transpiration rate, and sinusoidal potential transpiration lead to larger stress than when imposed as a constant boundary condition. Macroscopic parameters are usually computed as single values for each crop and used for the entire growing season. However, our study shows that both tolerance value and shape parameter p from the van Genuchten and Hoffman (1984) function were highly dependent on both potential transpiration and RLD. Plant salt tolerance was lower under high evaporative demand and lower RLD. In addition, the shape of the stress curve, which is defined by p, was found to be steeper under larger RLD and low transpiration rate. Time-variant macroscopic parameters based on knowledge of current potential transpiration rate per root unit length would be more convenient to accurately predict osmotic stress, and hence root water uptake, during a growing season. In a next step, simulations considering the whole root systems will be conducted to assess how macroscopic parameters are also related to root architectural characteristics. van Genuchten, M.T., Hoffman, G., 1984. Analysis of crop production. Soil Salin. Irrig. Springer Berl. 258-271.

Telomere length in alcohol dependence: A role for impulsive choice and childhood maltreatment.

PubMed

Kang, Jee In; Hwang, Syung Shick; Choi, Jong Rak; Lee, Seung-Tae; Kim, Jieun; Hwang, In Sik; Kim, Hae Won; Kim, Chan-Hyung; Kim, Se Joo

2017-09-01

Telomere shortening, a marker of cellular aging, has been considered to be linked with psychosocial stress as well as with chronic alcohol consumption, possibly mediated by oxidative stress and inflammatory response. Recent findings suggested that early life adversity on telomere dynamics may be related to impulsive choice. To further our understanding of the association of impulsive choice and childhood trauma on telomere length, we examined whether delayed discounting and childhood trauma or their interaction is related to leukocyte telomere length, while controlling for multiple potential confounding variables, in patients with alcohol dependence who are considered to have higher impulsive choice and shorter telomere length. We recruited 253 male patients with chronic alcohol dependence. All participants performed the delay discounting task, and the area under curve was used as a measure of delay discounting. Steeper delay discounting represents more impulsive choices. The modified Parent-Child Conflict Tactics Scale was used to measure childhood maltreatment. In addition, confounding factors, including socio-demographic characteristics, the Alcohol Use Disorders Identification Test, the Buss-Perry Aggression Questionnaire, the Resilience Quotient, the Beck Depression Inventory, and the Beck Anxiety Inventory, were also assessed. Hierarchical regression analyses showed a significant main effect of delay discounting (β=0.161, t=2.640, p=0.009), and an interaction effect between delay discounting and childhood maltreatment on leukocyte telomere length (β=0.173, t=2.138, p=0.034). In subsequent analyses stratified by childhood maltreatment, patients with alcohol dependence and high childhood trauma showed a significant relationship between delay discounting and leukocyte telomere length (β=0.279, t=3.183, p=0.002), while those with low trauma showed no association between them. Our findings suggest that higher impulsive choice is associated with shorter telomere length, and childhood trauma may exert a moderating effect in the relationship between impulsive choice and telomere length. Copyright © 2017. Published by Elsevier Ltd.

Sarcomere length-dependence of activity-dependent twitch potentiation in mouse skeletal muscle

PubMed Central

Rassier, Dilson E; MacIntosh, Brian R

2002-01-01

Background It has been reported that potentiation of a skeletal muscle twitch response is proportional to muscle length with a negative slope during staircase, and a positive slope during posttetanic potentiation. This study was done to directly compare staircase and posttetanic responses with measurement of sarcomere length to compare their length-dependence. Methods Mouse extensor digitorum longus (EDL) muscles were dissected to small bundles of fibers, which permit measurement of sarcomere length (SL), by laser diffraction. In vitro fixed-end contractions of EDL fiber bundles were elicited at 22°C and 35°C at sarcomere lengths ranging from 2.35 μm to 3.85 μm. Twitch contractions were assessed before and after 1.5 s of 75 Hz stimulation at 22°C or during 10 s of 10 Hz stimulation at 22°C or 35°C. Results Staircase potentiation was greater at 35°C than 22°C, and the relative magnitude of the twitch contraction (Pt*/Pt) was proportional to sarcomere length with a negative slope, over the range 2.3 μm – 3.7 μm. Linear regression yielded the following: Pt*/Pt = -0.59·SL+3.27 (r2 = 0.74); Pt*/Pt = -0.39·SL+2.34 (r2 = 0.48); and Pt*/Pt = -0.50·SL+2.45 (r2 = 0.80) for staircase at 35°C, and 22°C and posttetanic response respectively. Posttetanic depression rather than potentiation was present at long SL. This indicates that there may be two processes operating in these muscles to modulate the force: one that enhances and a second that depresses the force. Either or both of these processes may have a length-dependence of its mechanism. Conclusion There is no evidence that posttetanic potentiation is fundamentally different from staircase in these muscles. PMID:12475395

Subtle charge balance controls surface-nucleated self-assembly of designed biopolymers.

PubMed

Charbonneau, Céline; Kleijn, J Mieke; Cohen Stuart, Martien A

2014-03-25

We report the surface-nucleated self-assembly into fibrils of a biosynthetic amino acid polymer synthesized by the yeast Pichia pastoris. This polymer has a block-like architecture, with a central silk-like block labeled SH, responsible for the self-assembly into fibrils, and two collagen-like random coil end blocks (C) that colloidally stabilize the fibers in aqueous solution. The silk-like block contains histidine residues (pKa≈6) that are positively charged in the low pH region, which hinders self-assembly. In aqueous solution, CSHC self-assembles into fibers above a pH-dependent critical nucleation concentration Ccb. Below Ccb, where no self-assembly occurs in solution, fibril formation can be induced by a negatively charged surface (silica) in the pH range of 3.5-7. The density of the fibers at the surface and their length are controlled by a subtle balance in charge between the protein polymer and the silica surface, which is evidenced from the dependence on pH. With increasing number density of the fibers at the surface, their average length decreases. The results can be explained on the basis of a nucleation-and-growth mechanism: the surface density of fibers depends on the rate of nucleation, while their growth rate is limited by transport of proteins from solution. Screening of the charges on the surface and histidine units by adding NaCl influences the nucleation-and-growth process in a complicated fashion: at low pH, the growth is improved, while at high pH, the nucleation is limited. Under conditions where nucleation in the bulk solution is not possible, growth of the surface-nucleated fibers into the solution--away from the surface--can still occur.

In Vivo Imaging of Human Sarcomere Twitch Dynamics in Individual Motor Units.

PubMed

Sanchez, Gabriel N; Sinha, Supriyo; Liske, Holly; Chen, Xuefeng; Nguyen, Viet; Delp, Scott L; Schnitzer, Mark J

2015-12-16

Motor units comprise a pre-synaptic motor neuron and multiple post-synaptic muscle fibers. Many movement disorders disrupt motor unit contractile dynamics and the structure of sarcomeres, skeletal muscle's contractile units. Despite the motor unit's centrality to neuromuscular physiology, no extant technology can image sarcomere twitch dynamics in live humans. We created a wearable microscope equipped with a microendoscope for minimally invasive observation of sarcomere lengths and contractile dynamics in any major skeletal muscle. By electrically stimulating twitches via the microendoscope and visualizing the sarcomere displacements, we monitored single motor unit contractions in soleus and vastus lateralis muscles of healthy individuals. Control experiments verified that these evoked twitches involved neuromuscular transmission and faithfully reported muscle force generation. In post-stroke patients with spasticity of the biceps brachii, we found involuntary microscopic contractions and sarcomere length abnormalities. The wearable microscope facilitates exploration of many basic and disease-related neuromuscular phenomena never visualized before in live humans. Copyright © 2015 Elsevier Inc. All rights reserved.

Relationship between the tensile strengths and diameters of human umbilical cords.

PubMed

Fernando, D M G; Gamage, S M K; Ranmohottige, S; Weerakkody, I; Abeyruwan, H; Parakrama, H

2018-05-01

Mothers of alleged infanticides might claim that umbilical cord broke during precipitate delivery causing injuries detected on baby at autopsy. There is paucity of evidence regarding this possibility. The objective of the study was to determine relationship between tensile strength and diameter or weight per unit length of cord. Diameters and weights per unit length of fresh umbilical cords were determined. Tensile strengths were measured by Hounsfield Testing Machine. Relationship between tensile strength versus cord diameter and weight per unit length were analyzed. Of 122 cords, average tensile strength, diameter and weight per centimeter were 50.4 N, 7.73 mm and 6.87 g respectively. The tensile strengths were directly proportional to diameter. There was no association between tensile strength and weight per centimeter. Measurement of the diameter of cord is important during autopsy to predict tensile strength and thereby to presume whether cord could have broken by the weight of the baby. Copyright © 2018 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Molecular modeling of proteinlike inclusions in lipid bilayers: lipid-mediated interactions.

PubMed

Kik, Richard A; Leermakers, Frans A M; Kleijn, J Mieke

2010-02-01

We investigated the insertion of transmembrane structures in a lipid bilayer and their interactions using self-consistent field theory. The lipids are coarse-grained on a united-atom level and consist of a phosphatidylcholinelike headgroup and two hydrophobic tails. The inclusions, acting as simple models for proteins that span biological membranes, are rigid rods (radius R ) with a hydrophobic surface and hydrophilic end caps. The insertion free energy Omega of an individual rod is strongly regulated by the affinity between its hydrophobic surface and the lipid tails. This affinity also controls the best match of the hydrophobic length of the rod with that of the bilayer. The line tension tau(=Omega/2piR) is practically independent of R . The perturbations in the bilayer as a function of distance from the inclusion, have the shape of a damped oscillation. The wavelength and decay length are related to the elastic properties of the bilayer and do not depend on R . These results are used to analyze how the lipid matrix affects the interaction between transmembrane objects, for computational reasons considering the limit of R-->infinity . Contributions on different length scales can be distinguished: (i) a long-range elastic interaction, which is an exponentially decaying oscillation; (ii) an exponentially decaying repulsion on an intermediate length scale, resulting from the loss of conformational entropy of the lipid tails; and (iii) a short-range interaction due to the finite compressibility of the lipid tails, which manifests either as a depletion attraction if there is no affinity between the tails and the inclusions' surface or, otherwise, as an oscillatory structural force.

Spin-transistor action in waveguides with periodically modulated strength of the spin-orbit interaction

NASA Astrophysics Data System (ADS)

Vasilopoulos, P.; Wang, X. F.

2004-03-01

Spin-polarized electron transport through waveguides, in which the strength a of the spin-orbit interaction is varied periodically, is studied using the transfer-matrix technique. It is shown that the transmission T exhibits a spin-transistor action, as a function of a or of the length of one of the two subunits of the unit cell if only one mode is allowed to propagate in the waveguide. A similar but not periodic behavior is shown by T as a function of the elec-tron energy E. In a waveguide with only one segment, of strength a2 and length l2, comprised between two segments of strength a1, the total transmission, obtained as T=1/[cos2(D2*l2)+r*sin2(D2*l2)], shows a sinusoidal dependence. The spin-up (T+) and spin-down (T-) transmissions are given by T+=T cos2x and T-=T sin2x, where x is a measure of the spin precession. The total phase acquired by electrons in different branches during propagation is x=2[d1*(L-l2)+ d2*l2] with di=2m*a1/h2 and L the waveguide length. The transmission through a superlattice, with alternating segments of lengths l1, l2, and strengths a1, a2, is also a periodic function of aj and lj, j=1,2. As the strength a can be controlled by applying gates, the structure considered is a good candidate for the establishment of a realistic spin transistor.

Vitamin D serum levels are associated with handgrip strength but not with muscle mass or length of hospital stay after hip fracture.

PubMed

Gumieiro, David Nicoletti; Murino Rafacho, Bruna Paola; Buzati Pereira, Bruna Letícia; Cavallari, Karelin Alvisi; Tanni, Suzana Erico; Azevedo, Paula Schmidt; Polegato, Bertha Furlan; Mamede Zornoff, Leonardo Antonio; Dinhane, Daniel Innocenti; Innocenti Dinhane, Kandir Genésio; Cação Pereira, Gilberto José; de Paiva, Sergio Alberto Rupp; Minicucci, Marcos Ferreira

2015-01-01

The aim of this study was to evaluate the association between serum levels of 25(OH) vitamin D3 with midupper arm muscle circumference (MUAMC), handgrip strength and length of hospital stay (LOS) after hip fracture. In total, 102 consecutive patients with hip fracture over the age of 65 were admitted to the orthopedic unit and prospectively evaluated. All of the patients were treated according to specific protocols depending on the type of fracture. Anthropometric measurements and handgrip strength were performed, and blood samples were taken for serum biochemistry and 25(OH) vitamin D3 analysis within the first 72 h of admission. All of the patients were followed during their hospital stay, and the length of stay was recorded. Of the patients, two were excluded because of pathologic fractures. In total, 100 patients with a mean age of 80 ± 7 y were included in the analysis. Among these patients, 73% were female, and 37% had vitamin D deficiency. The median LOS was 7 (5-11) d. Patients with vitamin D deficiency had lower handgrip strength in univariate analysis. In the multiple linear regression analysis with robust standard error, serum vitamin D levels adjusted by age and sex were associated with handgrip strength but not with MUAMC and LOS after hip fracture. In conclusion, vitamin D serum levels were associated with handgrip strength but not with muscle mass or length of hospital stay after hip fracture. Copyright © 2015 Elsevier Inc. All rights reserved.

Engineered superlattices with crossover from decoupled to synthetic ferromagnetic behavior

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

Chopdekar, Rajesh V.; Malik, Vivek K.; Kane, Alexander M.

The extent of interfacial charge transfer and the resulting impact on magnetic interactions were investigated as a function of sublayer thickness in La 0.7Sr 0.3MnO 3/La 0.7Sr 0.3CoO 3 ferromagnetic superlattices. Element-specific soft x-ray magnetic spectroscopy reveals that the electronic structure is altered within 5–6 unit cells of the chemical interface, and can lead to a synthetic ferromagnet with strong magnetic coupling between the sublayers. The saturation magnetization and coercivity depends sensitively on the sublayer thickness due to the length scale of this interfacial effect. For larger sublayer thicknesses, the La 0.7Sr 0.3MnO 3 and La 0.7Sr 0.3CoO 3 sublayersmore » are magnetically decoupled, displaying two independent magnetic transitions with little sublayer thickness dependence. Lastly, these results demonstrate how interfacial phenomena at perovskite oxide interfaces can be used to tailor their functional properties at the atomic scale.« less

Local atomic and magnetic structure of dilute magnetic semiconductor ( Ba , K ) ( Zn , Mn ) 2 As 2

DOE PAGES

Frandsen, Benjamin A.; Gong, Zizhou; Terban, Maxwell W.; ...

2016-09-06

We studied the atomic and magnetic structure of the dilute ferromagnetic semiconductor system (Ba,K)(Zn,Mn) 2As 2 through atomic and magnetic pair distribution function analysis of temperature-dependent x-ray and neutron total scattering data. Furthermore, we detected a change in curvature of the temperature-dependent unit cell volume of the average tetragonal crystallographic structure at a temperature coinciding with the onset of ferromagnetic order. We also observed the existence of a well-defined local orthorhombic structure on a short length scale of ≲5Å, resulting in a rather asymmetrical local environment of the Mn and As ions. Finally, the magnetic PDF revealed ferromagnetic alignment ofmore » Mn spins along the crystallographic c axis, with robust nearest-neighbor ferromagnetic correlations that exist even above the ferromagnetic ordering temperature. Finally, we discuss these results in the context of other experiments and theoretical studies on this system.« less

Statistical and hydrodynamic properties of double-ring polymers with a fixed linking number between twin rings.

PubMed

Uehara, Erica; Deguchi, Tetsuo

2014-01-28

For a double-ring polymer in solution we evaluate the mean-square radius of gyration and the diffusion coefficient through simulation of off-lattice self-avoiding double polygons consisting of cylindrical segments with radius rex of unit length. Here, a self-avoiding double polygon consists of twin self-avoiding polygons which are connected by a cylindrical segment. We show numerically that several statistical and dynamical properties of double-ring polymers in solution depend on the linking number of the constituent twin ring polymers. The ratio of the mean-square radius of gyration of self-avoiding double polygons with zero linking number to that of no topological constraint is larger than 1, in particular, when the radius of cylindrical segments rex is small. However, the ratio is almost constant with respect to the number of vertices, N, and does not depend on N. The large-N behavior of topological swelling is thus quite different from the case of knotted random polygons.

Surface structure analysis of BaSi2(100) epitaxial film grown on Si(111) using CAICISS

NASA Astrophysics Data System (ADS)

Okasaka, Shouta; Kubo, Osamu; Tamba, Daiki; Ohashi, Tomohiro; Tabata, Hiroshi; Katayama, Mitsuhiro

2015-05-01

Geometry and surface structure of a BaSi2(100) film on Si(111) formed by reactive deposition epitaxy (RDE) have been investigated using coaxial impact-collision ion scattering spectroscopy and atomic force microscopy. BaSi2(100) film can be grown only when the Ba deposition rate is sufficiently fast. It is revealed that a BaSi2(100) film grown at 600 °C has better crystallinity than a film grown at 750 °C owing to the mixture of planes other than (100) in the RDE process at higher temperatures. The azimuth angle dependence of the scattering intensity from Ba shows sixfold symmetry, indicating that the minimum height of surface steps on BaSi2(100) is half of the length of unit cell. By comparing the simulated azimuth angle dependences for more than ten surface models with experimental one, it is strongly indicated that the surface of a BaSi2(100) film grown on Si(111) is terminated by Si tetrahedra.

Engineered superlattices with crossover from decoupled to synthetic ferromagnetic behavior

DOE PAGES

Chopdekar, Rajesh V.; Malik, Vivek K.; Kane, Alexander M.; ...

2017-12-04

The extent of interfacial charge transfer and the resulting impact on magnetic interactions were investigated as a function of sublayer thickness in La 0.7Sr 0.3MnO 3/La 0.7Sr 0.3CoO 3 ferromagnetic superlattices. Element-specific soft x-ray magnetic spectroscopy reveals that the electronic structure is altered within 5–6 unit cells of the chemical interface, and can lead to a synthetic ferromagnet with strong magnetic coupling between the sublayers. The saturation magnetization and coercivity depends sensitively on the sublayer thickness due to the length scale of this interfacial effect. For larger sublayer thicknesses, the La 0.7Sr 0.3MnO 3 and La 0.7Sr 0.3CoO 3 sublayersmore » are magnetically decoupled, displaying two independent magnetic transitions with little sublayer thickness dependence. Lastly, these results demonstrate how interfacial phenomena at perovskite oxide interfaces can be used to tailor their functional properties at the atomic scale.« less

Sexual size dimorphism in three North Sea gadoids.

PubMed

Keyl, F; Kempf, A J; Sell, A F

2015-01-01

Existing biological data on whiting Merlangius merlangus, cod Gadus morhua and haddock Melanogrammus aeglefinus from a long-term international survey were analysed to address sexual size dimorphism (SSD) and its effect on their ecology and management. Results show that SSD, with larger females of the same age as males, is a result of higher growth rates in females. A direct consequence of SSD is the pronounced length-dependent female ratio that was found in all three gadoids in the North Sea. Female ratios of the three species changed from equality to female dominance at specific dominance transition lengths of c. 30, 35 and 60 cm for M. merlangus, G. morhua and M. aeglefinus, respectively. An analysis by area for M. merlangus also revealed length dependence of female ratios. SSD and length-dependent female ratios under most circumstances are inseparable. Higher overall energy demand as well as a higher energy uptake rate must result from the observed SSD and dimorphism in growth rates. Potential processes related to feeding, locomotion and physiology are proposed that could balance the increased energy investment of females. Potential consequences of SSD and length dependency of female ratios are the reduction of the reproductive potential of a stock due to size-selective fishing and biased assessment of the true size of the female spawning stock that could distort decisions in fisheries management. © 2014 The Fisheries Society of the British Isles.

Ethnomathematics study: uncovering units of length, area, and volume in Kampung Naga Society

NASA Astrophysics Data System (ADS)

Septianawati, T.; Turmudi; Puspita, E.

2017-02-01

During this time, mathematics is considered as something neutral and not associated with culture. It can be seen from mathematics learning in the school which adopt many of foreign mathematics learning are considered more advanced (western). In fact, Indonesia is a rich country in cultural diversity. In the cultural activities, there are mathematical ideas that were considered a important thing in the mathematics learning. A study that examines the idea or mathematical practices in a variety of cultural activities are known as ethnomathematics. In Indonesia, there are some ethnic maintain their ancestral traditions, one of them is Kampung Naga. Therefore, this study was conducted in Kampung Naga. This study aims to uncover units of length, area, and volume used by Kampung Naga society. This study used a qualitative approach and ethnography methods. In this research, data collection is done through the principles of ethnography such as observation, interviews, documentation, and field notes. The results of this study are units of length, area, and volume used by Kampung Naga society and its conversion into standard units. This research is expected to give information to the public that mathematics has a relationship with culture and become recommendation to mathematics curriculum in Indonesia.

Reliability-based management of buried pipelines considering external corrosion defects

NASA Astrophysics Data System (ADS)

Miran, Seyedeh Azadeh

Corrosion is one of the main deteriorating mechanisms that degrade the energy pipeline integrity, due to transferring corrosive fluid or gas and interacting with corrosive environment. Corrosion defects are usually detected by periodical inspections using in-line inspection (ILI) methods. In order to ensure pipeline safety, this study develops a cost-effective maintenance strategy that consists of three aspects: corrosion growth model development using ILI data, time-dependent performance evaluation, and optimal inspection interval determination. In particular, the proposed study is applied to a cathodic protected buried steel pipeline located in Mexico. First, time-dependent power-law formulation is adopted to probabilistically characterize growth of the maximum depth and length of the external corrosion defects. Dependency between defect depth and length are considered in the model development and generation of the corrosion defects over time is characterized by the homogenous Poisson process. The growth models unknown parameters are evaluated based on the ILI data through the Bayesian updating method with Markov Chain Monte Carlo (MCMC) simulation technique. The proposed corrosion growth models can be used when either matched or non-matched defects are available, and have ability to consider newly generated defects since last inspection. Results of this part of study show that both depth and length growth models can predict damage quantities reasonably well and a strong correlation between defect depth and length is found. Next, time-dependent system failure probabilities are evaluated using developed corrosion growth models considering prevailing uncertainties where three failure modes, namely small leak, large leak and rupture are considered. Performance of the pipeline is evaluated through failure probability per km (or called a sub-system) where each subsystem is considered as a series system of detected and newly generated defects within that sub-system. Sensitivity analysis is also performed to determine to which incorporated parameter(s) in the growth models reliability of the studied pipeline is most sensitive. The reliability analysis results suggest that newly generated defects should be considered in calculating failure probability, especially for prediction of long-term performance of the pipeline and also, impact of the statistical uncertainty in the model parameters is significant that should be considered in the reliability analysis. Finally, with the evaluated time-dependent failure probabilities, a life cycle-cost analysis is conducted to determine optimal inspection interval of studied pipeline. The expected total life-cycle costs consists construction cost and expected costs of inspections, repair, and failure. The repair is conducted when failure probability from any described failure mode exceeds pre-defined probability threshold after each inspection. Moreover, this study also investigates impact of repair threshold values and unit costs of inspection and failure on the expected total life-cycle cost and optimal inspection interval through a parametric study. The analysis suggests that a smaller inspection interval leads to higher inspection costs, but can lower failure cost and also repair cost is less significant compared to inspection and failure costs.

The Metric System of Measurement (SI). Federal Register Notice of December 10, 1976.

ERIC Educational Resources Information Center

National Bureau of Standards (DOC), Washington, DC.

This document provides a diagram illustrating the relationships between base units in the metric system and derived units with special names. Twenty-one derived units are included. The base units used are: measures of mass, length, time, amount of substance, electric current, thermo-dynamic temperature, luminous intensity, and plane and solid…

Length of Residence in the United States is Associated With a Higher Prevalence of Cardiometabolic Risk Factors in Immigrants: A Contemporary Analysis of the National Health Interview Survey.

PubMed

Commodore-Mensah, Yvonne; Ukonu, Nwakaego; Obisesan, Olawunmi; Aboagye, Jonathan Kumi; Agyemang, Charles; Reilly, Carolyn M; Dunbar, Sandra B; Okosun, Ike S

2016-11-04

Cardiometabolic risk (CMR) factors including hypertension, overweight/obesity, diabetes mellitus, and hyperlipidemia are high among United States ethnic minorities, and the immigrant population continues to burgeon. Hypothesizing that acculturation (length of residence) would be associated with a higher prevalence of CMR factors, the authors analyzed data on 54, 984 US immigrants in the 2010-2014 National Health Interview Surveys. The main predictor was length of residence. The outcomes were hypertension, overweight/obesity, diabetes mellitus, and hyperlipidemia. The authors used multivariable logistic regression to examine the association between length of US residence and these CMR factors.The mean (SE) age of the patients was 43 (0.12) years and half were women. Participants residing in the United States for ≥10 years were more likely to have health insurance than those with <10 years of residence (70% versus 54%, P<0.001). After adjusting for region of birth, poverty income ratio, age, and sex, immigrants residing in the United States for ≥10 years were more likely to be overweight/obese (odds ratio [OR], 1.19; 95% CI, 1.10-1.29), diabetic (OR, 1.43; 95% CI, 1.17-1.73), and hypertensive (OR, 1.18; 95% CI, 1.05-1.32) than those residing in the United States for <10 years. In an ethnically diverse sample of US immigrants, acculturation was associated with CMR factors. Culturally tailored public health strategies should be developed in US immigrant populations to reduce CMR. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Essential energy space random walks to accelerate molecular dynamics simulations: Convergence improvements via an adaptive-length self-healing strategy

NASA Astrophysics Data System (ADS)

Zheng, Lianqing; Yang, Wei

2008-07-01

Recently, accelerated molecular dynamics (AMD) technique was generalized to realize essential energy space random walks so that further sampling enhancement and effective localized enhanced sampling could be achieved. This method is especially meaningful when essential coordinates of the target events are not priori known; moreover, the energy space metadynamics method was also introduced so that biasing free energy functions can be robustly generated. Despite the promising features of this method, due to the nonequilibrium nature of the metadynamics recursion, it is challenging to rigorously use the data obtained at the recursion stage to perform equilibrium analysis, such as free energy surface mapping; therefore, a large amount of data ought to be wasted. To resolve such problem so as to further improve simulation convergence, as promised in our original paper, we are reporting an alternate approach: the adaptive-length self-healing (ALSH) strategy for AMD simulations; this development is based on a recent self-healing umbrella sampling method. Here, the unit simulation length for each self-healing recursion is increasingly updated based on the Wang-Landau flattening judgment. When the unit simulation length for each update is long enough, all the following unit simulations naturally run into the equilibrium regime. Thereafter, these unit simulations can serve for the dual purposes of recursion and equilibrium analysis. As demonstrated in our model studies, by applying ALSH, both fast recursion and short nonequilibrium data waste can be compromised. As a result, combining all the data obtained from all the unit simulations that are in the equilibrium regime via the weighted histogram analysis method, efficient convergence can be robustly ensured, especially for the purpose of free energy surface mapping.

40 CFR Table 28 to Subpart G of... - Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Deck Seam Length Factors a (SD) for... (SD) for Internal Floating Roof Tanks Deck construction Typical deck seam length factor Continuous... decks only. Units for SD are feet per square feet. b SD=1/W, where W = sheet width (feet). c If no...

40 CFR Table 28 to Subpart G of... - Deck Seam Length Factors a (SD) for Internal Floating Roof Tanks

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Deck Seam Length Factors a (SD) for... (SD) for Internal Floating Roof Tanks Deck construction Typical deck seam length factor Continuous... decks only. Units for SD are feet per square feet. b SD=1/W, where W = sheet width (feet). c If no...

16 CFR 500.12 - Measurement of commodities by length and width, how expressed.

Code of Federal Regulations, 2013 CFR

2013-01-01

... square foot (929 cm2) be expressed in terms of length and width in linear measure. The customary inch... of 1 square foot (929 cm2) or more, but less than 4 square feet (37.1 dm2), be expressed in terms of... in square inches with length and width expressed in the largest whole unit (yard or foot) with any...

16 CFR 500.12 - Measurement of commodities by length and width, how expressed.

Code of Federal Regulations, 2011 CFR

2011-01-01

... square foot (929 cm2) be expressed in terms of length and width in linear measure. The customary inch... of 1 square foot (929 cm2) or more, but less than 4 square feet (37.1 dm2), be expressed in terms of... in square inches with length and width expressed in the largest whole unit (yard or foot) with any...

16 CFR 500.12 - Measurement of commodities by length and width, how expressed.

Code of Federal Regulations, 2014 CFR

2014-01-01

... square foot (929 cm2) be expressed in terms of length and width in linear measure. The customary inch... of 1 square foot (929 cm2) or more, but less than 4 square feet (37.1 dm2), be expressed in terms of... in square inches with length and width expressed in the largest whole unit (yard or foot) with any...

16 CFR 500.12 - Measurement of commodities by length and width, how expressed.

Code of Federal Regulations, 2012 CFR

2012-01-01

... square foot (929 cm2) be expressed in terms of length and width in linear measure. The customary inch... of 1 square foot (929 cm2) or more, but less than 4 square feet (37.1 dm2), be expressed in terms of... in square inches with length and width expressed in the largest whole unit (yard or foot) with any...

Telomere length profiles in primary human peritoneal mesothelial cells are consistent with senescence.

PubMed

Lopez-Anton, Melisa; Rudolf, András; Baird, Duncan M; Roger, Laureline; Jones, Rhiannon E; Witowski, Janusz; Fraser, Donald J; Bowen, Timothy

2017-06-01

Mesothelial cell (MC) senescence contributes to malignancy and tissue fibrosis. The role of telomere erosion in MC senescence remains controversial, with evidence for both telomere-dependent and telomere-independent mechanisms reported. Single telomere length analysis revealed considerable telomere length heterogeneity in freshly isolated human peritoneal MCs, reflecting a heterogeneous proliferative history and providing high-resolution evidence for telomere-dependent senescence. By contrast the attenuated replicative lifespan, lack of telomere erosion and induction of p16 expression in in vitro-aged cells was consistent with stress-induced senescence. Given the potential pathophysiological impact of senescence in mesothelial tissues, high-resolution MC telomere length analysis may provide clinically useful information. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Agribusiness Management. The Connecticut Vocational Agriculture Curriculum.

ERIC Educational Resources Information Center

EASTCONN Regional Educational Services Center, North Windham, CT.

These materials in agribusiness management for the Connecticut Vocational Agriculture Curriculum were designed for use in the following areas: Animal Science; Plant Science; Agricultural Mechanics; and Natural Resources and Aquaculture. Each unit of this competency-based guide contains title of unit, unit length, grade level, objectives, teacher…

Optimal Hydrophobicity in Ring-Opening Metathesis Polymerization-Based Protein Mimics Required for siRNA Internalization.

PubMed

deRonde, Brittany M; Posey, Nicholas D; Otter, Ronja; Caffrey, Leah M; Minter, Lisa M; Tew, Gregory N

2016-06-13

Exploring the role of polymer structure for the internalization of biologically relevant cargo, specifically siRNA, is of critical importance to the development of improved delivery reagents. Herein, we report guanidinium-rich protein transduction domain mimics (PTDMs) based on a ring-opening metathesis polymerization scaffold containing tunable hydrophobic moieties that promote siRNA internalization. Structure-activity relationships using Jurkat T cells and HeLa cells were explored to determine how the length of the hydrophobic block and the hydrophobic side chain compositions of these PTDMs impacted siRNA internalization. To explore the hydrophobic block length, two different series of diblock copolymers were synthesized: one series with symmetric block lengths and one with asymmetric block lengths. At similar cationic block lengths, asymmetric and symmetric PTDMs promoted siRNA internalization in the same percentages of the cell population regardless of the hydrophobic block length; however, with 20 repeat units of cationic charge, the asymmetric block length had greater siRNA internalization, highlighting the nontrivial relationships between hydrophobicity and overall cationic charge. To further probe how the hydrophobic side chains impacted siRNA internalization, an additional series of asymmetric PTDMs was synthesized that featured a fixed hydrophobic block length of five repeat units that contained either dimethyl (dMe), methyl phenyl (MePh), or diphenyl (dPh) side chains and varied cationic block lengths. This series was further expanded to incorporate hydrophobic blocks consisting of diethyl (dEt), diisobutyl (diBu), and dicyclohexyl (dCy) based repeat units to better define the hydrophobic window for which our PTDMs had optimal activity. High-performance liquid chromatography retention times quantified the relative hydrophobicities of the noncationic building blocks. PTDMs containing the MePh, diBu, and dPh hydrophobic blocks were shown to have superior siRNA internalization capabilities compared to their more and less hydrophobic counterparts, demonstrating a critical window of relative hydrophobicity for optimal internalization. This better understanding of how hydrophobicity impacts PTDM-induced internalization efficiencies will help guide the development of future delivery reagents.

Relationship Between Labor and Delivery Unit Management Practices and Maternal Outcomes.

PubMed

Plough, Avery C; Galvin, Grace; Li, Zhonghe; Lipsitz, Stuart R; Alidina, Shehnaz; Henrich, Natalie J; Hirschhorn, Lisa R; Berry, William R; Gawande, Atul A; Peter, Doris; McDonald, Rory; Caldwell, Donna L; Muri, Janet H; Bingham, Debra; Caughey, Aaron B; Declercq, Eugene R; Shah, Neel T

2017-08-01

To define, measure, and characterize key competencies of managing labor and delivery units in the United States and assess the associations between unit management and maternal outcomes. We developed and administered a management measurement instrument using structured telephone interviews with both the primary nurse and physician managers at 53 diverse hospitals across the United States. A trained interviewer scored the managers' interview responses based on management practices that ranged from most reactive (lowest scores) to most proactive (highest scores). We established instrument validity by conducting site visits among a subsample of 11 hospitals and established reliability using interrater comparison. Using a factor analysis, we identified three themes of management competencies: management of unit culture, patient flow, and nursing. We constructed patient-level regressions to assess the independent association between these management themes and maternal outcomes. Proactive management of unit culture and nursing was associated with a significantly higher risk of primary cesarean delivery in low-risk patients (relative risk [RR] 1.30, 95% CI 1.02-1.66 and RR 1.47, 95% CI 1.13-1.92, respectively). Proactive management of unit culture was also associated with a significantly higher risk of prolonged length of stay (RR 4.13, 95% CI 1.98-8.64), postpartum hemorrhage (RR 2.57, 95% CI 1.58-4.18), and blood transfusion (RR 1.87, 95% CI 1.12-3.13). Proactive management of patient flow and nursing was associated with a significantly lower risk of prolonged length of stay (RR 0.23, 95% CI 0.12-0.46 and RR 0.27, 95% CI 0.11-0.62, respectively). Labor and delivery unit management varies dramatically across and within hospitals in the United States. Some proactive management practices may be associated with increased risk of primary cesarean delivery and maternal morbidity. Other proactive management practices may be associated with decreased risk of prolonged length of stay, indicating a potential opportunity to safely improve labor and delivery unit efficiency.

In vitro cytotoxicity of Manville Code 100 glass fibers: Effect of fiber length on human alveolar macrophages

PubMed Central

Zeidler-Erdely, Patti C; Calhoun, William J; Ameredes, Bill T; Clark, Melissa P; Deye, Gregory J; Baron, Paul; Jones, William; Blake, Terri; Castranova, Vincent

2006-01-01

Background Synthetic vitreous fibers (SVFs) are inorganic noncrystalline materials widely used in residential and industrial settings for insulation, filtration, and reinforcement purposes. SVFs conventionally include three major categories: fibrous glass, rock/slag/stone (mineral) wool, and ceramic fibers. Previous in vitro studies from our laboratory demonstrated length-dependent cytotoxic effects of glass fibers on rat alveolar macrophages which were possibly associated with incomplete phagocytosis of fibers ≥ 17 μm in length. The purpose of this study was to examine the influence of fiber length on primary human alveolar macrophages, which are larger in diameter than rat macrophages, using length-classified Manville Code 100 glass fibers (8, 10, 16, and 20 μm). It was hypothesized that complete engulfment of fibers by human alveolar macrophages could decrease fiber cytotoxicity; i.e. shorter fibers that can be completely engulfed might not be as cytotoxic as longer fibers. Human alveolar macrophages, obtained by segmental bronchoalveolar lavage of healthy, non-smoking volunteers, were treated with three different concentrations (determined by fiber number) of the sized fibers in vitro. Cytotoxicity was assessed by monitoring cytosolic lactate dehydrogenase release and loss of function as indicated by a decrease in zymosan-stimulated chemiluminescence. Results Microscopic analysis indicated that human alveolar macrophages completely engulfed glass fibers of the 20 μm length. All fiber length fractions tested exhibited equal cytotoxicity on a per fiber basis, i.e. increasing lactate dehydrogenase and decreasing chemiluminescence in the same concentration-dependent fashion. Conclusion The data suggest that due to the larger diameter of human alveolar macrophages, compared to rat alveolar macrophages, complete phagocytosis of longer fibers can occur with the human cells. Neither incomplete phagocytosis nor length-dependent toxicity was observed in fiber-exposed human macrophage cultures. In contrast, rat macrophages exhibited both incomplete phagocytosis of long fibers and length-dependent toxicity. The results of the human and rat cell studies suggest that incomplete engulfment may enhance cytotoxicity of fiber glass. However, the possibility should not be ruled out that differences between human versus rat macrophages other than cell diameter could account for differences in fiber effects. PMID:16569233

Primary Beam Air Kerma Dependence on Distance from Cargo and People Scanners

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

Strom, Daniel J.; Cerra, Frank

The distance dependence of air kerma or dose rate of the primary radiation beam is not obvious for security scanners of cargo and people in which there is relative motion between a collimated source and the person or object being imaged. To study this problem, one fixed line source and three moving-source scan-geometry cases are considered, each characterized by radiation emanating perpendicular to an axis. The cases are 1) a stationary line source of radioactive material, e.g., contaminated solution in a pipe; 2) a moving, uncollimated point source of radiation that is shuttered or off when it is stationary; 3)more » a moving, collimated point source of radiation that is shuttered or off when it is stationary; and 4) a translating, narrow “pencil” beam emanating in a flying-spot, raster pattern. Each case is considered for short and long distances compared to the line source length or path traversed by a moving source. The short distance model pertains mostly to dose to objects being scanned and personnel associated with the screening operation. The long distance model pertains mostly to potential dose to bystanders. For radionuclide sources, the number of nuclear transitions that occur a) per unit length of a line source, or b) during the traversal of a point source, is a unifying concept. The “universal source strength” of air kerma rate at a meter from the source can be used to describe x-ray machine or radionuclide sources. For many cargo and people scanners with highly collimated fan or pencil beams, dose varies as the inverse of the distance from the source in the near field and with the inverse square of the distance beyond a critical radius. Ignoring the inverse square dependence and using inverse distance dependence is conservative in the sense of tending to overestimate dose.« less

Primary Beam Air Kerma Dependence on Distance from Cargo and People Scanners.

PubMed

Strom, Daniel J; Cerra, Frank

2016-06-01

The distance dependence of air kerma or dose rate of the primary radiation beam is not obvious for security scanners of cargo and people in which there is relative motion between a collimated source and the person or object being imaged. To study this problem, one fixed line source and three moving-source scan-geometry cases are considered, each characterized by radiation emanating perpendicular to an axis. The cases are 1) a stationary line source of radioactive material, e.g., contaminated solution in a pipe; 2) a moving, uncollimated point source of radiation that is shuttered or off when it is stationary; 3) a moving, collimated point source of radiation that is shuttered or off when it is stationary; and 4) a translating, narrow "pencil" beam emanating in a flying-spot, raster pattern. Each case is considered for short and long distances compared to the line source length or path traversed by a moving source. The short distance model pertains mostly to dose to objects being scanned and personnel associated with the screening operation. The long distance model pertains mostly to potential dose to bystanders. For radionuclide sources, the number of nuclear transitions that occur a) per unit length of a line source or b) during the traversal of a point source is a unifying concept. The "universal source strength" of air kerma rate at 1 m from the source can be used to describe x-ray machine or radionuclide sources. For many cargo and people scanners with highly collimated fan or pencil beams, dose varies as the inverse of the distance from the source in the near field and with the inverse square of the distance beyond a critical radius. Ignoring the inverse square dependence and using inverse distance dependence is conservative in the sense of tending to overestimate dose.

All-optical, thermo-optical path length modulation based on the vanadium-doped fibers.

PubMed

Matjasec, Ziga; Campelj, Stanislav; Donlagic, Denis

2013-05-20

This paper presents an all-fiber, fully-optically controlled, optical-path length modulator based on highly absorbing optical fiber. The modulator utilizes a high-power 980 nm pump diode and a short section of vanadium-co-doped single mode fiber that is heated through absorption and a non-radiative relaxation process. The achievable path length modulation range primarily depends on the pump's power and the convective heat-transfer coefficient of the surrounding gas, while the time response primarily depends on the heated fiber's diameter. An absolute optical length change in excess of 500 µm and a time-constant as short as 11 ms, were demonstrated experimentally. The all-fiber design allows for an electrically-passive and remote operation of the modulator. The presented modulator could find use within various fiber-optics systems that require optical (remote) path length control or modulation.

Factors associated with mortality and length of stay in the Oporto burn unit (2006-2009).

PubMed

Bartosch, Isabel; Bartosch, Carla; Egipto, Paula; Silva, Alvaro

2013-05-01

Retrospective studies are essential to evaluate and improve the efficiency of care of burned patients. This study analyses the work done in the burn unit of Hospital de S. João in the north of Portugal. A retrospective review was performed in patients admitted from 2006 to 2009. The study population was characterised regarding patient demographics, admissions profile, burn aetiology, burn site, extension and treatment. Multiple linear and logistic regression models were done in order to elucidate which of these factors influenced the mortality and length of stay. The characteristics before and after the creation of the burn unit, as well as the similarities and differences with the published data of other national and international burn units, are analysed. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

Significance of DNA bond strength in programmable nanoparticle thermodynamics and dynamics.

PubMed

Yu, Qiuyan; Hu, Jinglei; Hu, Yi; Wang, Rong

2018-04-04

Assembly of nanoparticles (NPs) coated with complementary DNA strands leads to novel crystals with nanosized basic units rather than classic atoms, ions or molecules. The assembly process is mediated by hybridization of DNA via specific base pairing interaction, and is kinetically linked to the disassociation of DNA duplexes. DNA-level physiochemical quantities, both thermodynamic and kinetic, are key to understanding this process and essential for the design of DNA-NP crystals. The melting transition properties are helpful to judge the thermostability and sensitivity of relative DNA probes or other applications. Three different cases are investigated by changing the linker length and the spacer length on which the melting properties depend using the molecular dynamics method. Melting temperature is determined by sigmoidal melting curves based on hybridization percentage versus temperature and the Lindemann melting rule simultaneously. We provide a computational strategy based on a coarse-grained model to estimate the hybridization enthalpy, entropy and free energy from percentages of hybridizations which are readily accessible in experiments. Importantly, the lifetime of DNA bond dehybridization based on temperature and the activation energy depending on DNA bond strength are also calculated. The simulation results are in good agreement with the theoretical analysis and the present experimental data. Our study provides a good strategy to predict the melting temperature which is important for the DNA-directed nanoparticle system, and bridges the dynamics and thermodynamics of DNA-directed nanoparticle systems by estimating the equilibrium constant from the hybridization of DNA bonds quantitatively.

Short-term outcome and differences between rural and urban trauma patients treated by mobile intensive care units in Northern Finland: a retrospective analysis.

PubMed

Raatiniemi, Lasse; Liisanantti, Janne; Niemi, Suvi; Nal, Heini; Ohtonen, Pasi; Antikainen, Harri; Martikainen, Matti; Alahuhta, Seppo

2015-11-05

Emergency medical services are an important part of trauma care, but data comparing urban and rural areas is needed. We compared 30-day mortality and length of intensive care unit (ICU) stay for trauma patients injured in rural and urban municipalities and collected basic data on trauma care in Northern Finland. We examined data from all trauma patients treated by the Finnish Helicopter Emergency Medical Services in 2012 and 2013. Only patients surviving to hospital were included in the analysis but all pre-hospital deaths were recorded. All data was retrieved from the national Helicopter Emergency Medical Services database, medical records, and the Finnish Causes of Death Registry. Patients were defined as urban or rural depending on the type of municipality where the injury occurred. A total of 472 patients were included. Age and Injury Severity Score did not differ between rural and urban patients. The pre-hospital time intervals and distances to trauma centers were longer for rural patients and a larger proportion of urban patients had intentional injuries (23.5% vs. 9.3%, P <0.001). The 30-day mortality for severely injured patients (Injury Severity Score >15) was 23.9% in urban and 13.3% in rural municipalities. In the multivariate regression analysis the odds ratio (OR) for 30-day mortality was 2.8 (95% confidence interval 1.0 to 7.9, P = 0.05) in urban municipalities. There was no difference in the length of ICU stay or scores. Twenty patients died on scene or during transportation and 56 missions were aborted because of pre-hospital death. The severely injured urban trauma patients had a trend toward higher 30-day mortality compared with patients injured in rural areas but the length of ICU stay was similar. However, more pre-hospital deaths occurred in rural municipalities. The time before mobile ICU arrival appears to be critical for trauma patients' survival, especially in rural areas.

Damage and recovery characteristics of lithium-containing solar cells.

NASA Technical Reports Server (NTRS)

Faith, T. J.

1971-01-01

Damage and recovery characteristics were measured on lithium-containing solar cells irradiated by 1-MeV electrons. Empirical expressions for cell recovery time, diffusion-length damage coefficient immediately after irradiation, and diffusion-length damage coefficient after recovery were derived using results of short-circuit current, diffusion-length, and reverse-bias capacitance measurements. The damage coefficients were expressed in terms of a single lithium density parameter, the lithium gradient. A fluence dependence was also established, this dependence being the same for both the immediate-post-irradiation and post-recovery cases. Cell recovery rates were found to increase linearly with lithium gradient.

Long-Term Care in Small Rural Hospitals.

ERIC Educational Resources Information Center

Bowlyow, Joyce E.

1989-01-01

Compared small rural hospitals with long-term care units to those without units. Found both hospital and community differences. Hospitals with such units were smaller and differed in length of stay, personnel, and expenses. Their counties were smaller in population and less urban, but did not have proportionally more elderly or different…

Distributive Education: Secondary, Course Outline. Revised 1972.

ERIC Educational Resources Information Center

Washington State Coordinating Council for Occupational Education, Olympia.

The document is a revision of earlier units, updated to include behavioral or performance objectives. Divided into 22 units of instruction, the course outline for distributive education presents suggested length of time for each part of a unit, prerequisites, a description of the part, objectives, sources, outline for the section, activities,…

Development of an adaptive harvest management program for Taiga bean geese

USGS Publications Warehouse

Johnson, Fred A.; Alhainen, Mikko; Fox, Anthony D.; Madsen, Jesper

2016-01-01

This report describes recent progress in specifying the elements of an adaptive harvest program for taiga bean goose. It describes harvest levels appropriate for first rebuilding the population of the Central Management Unit and then maintaining it near the goal specified in the AEWA International Single Species Action Plan (ISSAP). This report also provides estimates of the length of time it would take under ideal conditions (no density dependence and no harvest) to rebuild depleted populations in the Western and Eastern Management Units. We emphasize that our estimates are a first approximation because detailed demographic information is lacking for taiga bean geese. Using allometric relationships, we estimated parameters of a thetalogistic matrix population model. The mean intrinsic rate of growth was estimated as r = 0.150 (90% credible interval: 0.120 – 0.182). We estimated the mean form of density dependence as   2.361 (90% credible interval: 0.473 – 11.778), suggesting the strongest density dependence occurs when the population is near its carrying capacity. Based on expert opinion, carrying capacity (i.e., population size expected in the absence of hunting) for the Central Management Unit was estimated as K  87,900 (90% credible interval: 82,000 – 94,100). The ISSAP specifies a population goal for the Central Management Unit of 60,000 – 80,000 individuals in winter; thus, we specified a preliminary objective function as one which would minimize the difference between this goal and population size. Using the concept of stochastic dominance to explicitly account for uncertainty in demography, we determined that optimal harvest rates for 5, 10, 15, and 20-year time horizons were h = 0.00, 0.02, 0.05, and 0.06, respectively. These optima represent a tradeoff between the harvest rate and the time required to achieve and maintain a population size within desired bounds. We recognize, however, that regulation of absolute harvest rather than harvest rate is more practical, but our matrix model does not permit one to calculate an exact harvest associated with a specific harvest rate. Approximate harvests for current population size in the Central Management Unit are 0, 1,200, 2,300, and 3,500 for the 5, 10, 15, and 20-year time horizons, respectively. Populations of taiga bean geese in the Western and Eastern Units would require at least 10 and 13 years, respectively, to reach their minimum goals under the most optimistic of scenarios. The presence of harvest, density dependence, or environmental variation could extend these time frames considerably. Finally, we stress that development and implementation of internationally coordinated monitoring programs will be essential to further development and implementation of an adaptive harvest management program.

Body height and ocular dimensions in the adult population in rural Central India. The Central India Eye and Medical Study.

PubMed

Nangia, Vinay; Jonas, Jost B; Matin, Arshia; Kulkarni, Maithili; Sinha, Ajit; Gupta, Rajesh

2010-11-01

To investigate associations between anthropomorphic parameters and ocular dimensions in a typical rural society untouched by the effects of urbanization. The Central India Eye and Medical Study performed in rural Central India included 4,711 participants aged 30 or more years. The participants underwent a detailed ophthalmic and medical examination. After controlling for age, gender, level of education, and body mass index (BMI), taller subjects were more likely to have larger eyes with a longer axial length (+0.23 mm for each 10 cm increase in height), lower corneal refractive power (-0.50 diopters for each 10 cm increase in height), deeper anterior chambers (+0.03 mm for each 10 cm increase in height), and longer vitreous cavity (+0.20 mm for each 10 cm increase in height). Central corneal thickness (P = 0.97) and lens thickness (P = 0.08) were not significantly associated with body height. After controlling for age, gender, level of education and height, subjects with a higher BMI had shorter globes (-0.02 mm for each unit increase in BMI), flatter corneas (-0.03 diopters for each unit increase in BMI) and thicker corneas (+0.49 μm for each unit increase in BMI), thicker lenses and longer vitreous cavities. Body height as compared with the BMI had a stronger influence on the ocular biometric data. After correcting for age, gender, level of education and axial length, for each increase in body height by 10 cm or for each increase in BMI by one unit, the refractive error significantly increased by 0.23 diopters (P < 0.001) and by 0.40 diopters (P < 0.001) respectively. In the rural population of Central India without urbanization-associated myopization, body height and size of the eye were associated with each other: taller subjects had larger eyes with a flatter cornea. An increase in body height per 10 cm was associated with an increase in anterior chamber depth by 1% and an increase in vitreous cavity length by 1%. Subjects with a higher body mass index had shorter eyes, flatter and thicker corneas, and thicker lenses. Taller subjects and subjects with a higher BMI were more hyperopic. Since the occurrence of some ocular diseases depends on eye size and refractive error, the results may be helpful for screening examinations and for elucidating pathogenic associations.

Tolman lengths and rigidity constants of multicomponent fluids: Fundamental theory and numerical examples

NASA Astrophysics Data System (ADS)

Aasen, Ailo; Blokhuis, Edgar M.; Wilhelmsen, Øivind

2018-05-01

The curvature dependence of the surface tension can be described by the Tolman length (first-order correction) and the rigidity constants (second-order corrections) through the Helfrich expansion. We present and explain the general theory for this dependence for multicomponent fluids and calculate the Tolman length and rigidity constants for a hexane-heptane mixture by use of square gradient theory. We show that the Tolman length of multicomponent fluids is independent of the choice of dividing surface and present simple formulae that capture the change in the rigidity constants for different choices of dividing surface. For multicomponent fluids, the Tolman length, the rigidity constants, and the accuracy of the Helfrich expansion depend on the choice of path in composition and pressure space along which droplets and bubbles are considered. For the hexane-heptane mixture, we find that the most accurate choice of path is the direction of constant liquid-phase composition. For this path, the Tolman length and rigidity constants are nearly linear in the mole fraction of the liquid phase, and the Helfrich expansion represents the surface tension of hexane-heptane droplets and bubbles within 0.1% down to radii of 3 nm. The presented framework is applicable to a wide range of fluid mixtures and can be used to accurately represent the surface tension of nanoscopic bubbles and droplets.

Coarsening of stripe patterns: variations with quench depth and scaling.

PubMed

Tripathi, Ashwani K; Kumar, Deepak

2015-02-01

The coarsening of stripe patterns when the system is evolved from random initial states is studied by varying the quench depth ε, which is a measure of distance from the transition point of the stripe phase. The dynamics of the growth of stripe order, which is characterized by two length scales, depends on the quench depth. The growth exponents of the two length scales vary continuously with ε. The decay exponents for free energy, stripe curvature, and densities of defects like grain boundaries and dislocations also show similar variation. This implies a breakdown of the standard picture of nonequilibrium dynamical scaling. In order to understand the variations with ε we propose an additional scaling with a length scale dependent on ε. The main contribution to this length scale comes from the "pinning potential," which is unique to systems where the order parameter is spatially periodic. The periodic order parameter gives rise to an ε-dependent potential, which can pin defects like grain boundaries, dislocations, etc. This additional scaling provides a compact description of variations of growth exponents with quench depth in terms of just one exponent for each of the length scales. The relaxation of free energy, stripe curvature, and the defect densities have also been related to these length scales. The study is done at zero temperature using Swift-Hohenberg equation in two dimensions.

Sample Length Affects the Reliability of Language Sample Measures in 3-Year-Olds: Evidence from Parent-Elicited Conversational Samples

ERIC Educational Resources Information Center

Guo, Ling-Yu; Eisenberg, Sarita

2015-01-01

Purpose: The goal of this study was to investigate the extent to which sample length affected the reliability of total number of words (TNW), number of different words (NDW), and mean length of C-units in morphemes (MLCUm) in parent-elicited conversational samples for 3-year-olds. Method: Participants were sixty 3-year-olds. A 22-min language…

Tensile testing of thin-film microstructures

NASA Astrophysics Data System (ADS)

Greek, Staffan; Johansson, Stefan A. I.

1997-09-01

The mechanical properties of thin film microstructures depend on size and shape and on the film manufacturing process. Hence, the test structures that are used to measure mechanical properties should have dimensions of the same order of magnitude as an application structure. The microstructures are easily monitored in a scanning electron microscope (SEM), but to be handled and tested in situ a micromanipulator was developed. The parts of the micromanipulator essential to the tests are two independently moveable tables driven by electric motors. The test structures and a testing unit are mounted on the tables. A testing unit was designed to measure force and displacement with high resolution. The testing unit consists of an arm actuated by a piezoelectric element and equipped with a probe. An optical encoder measures the movement of the arm, while strain gauges measure the force in the arm. Test structures consist typically of a released beam fixed at one end with a ring at the other. The micromanipulator is used to position the probe of the testing unit in the ring. The testing unit then executed a tensile test of the beam. Test structures of polysilicon films produced under various process conditions were used to verify the possibility of measuring Young's modulus with an accuracy of +/- 5 percent, as well as fracture strength.Young's modulus is calculated using the difference in elongation for different beam lengths. The fracture strength of the beams was evaluated with Weibull statistics.

Mapping Optimal Charge Density and Length of ROMP-Based PTDMs for siRNA Internalization.

PubMed

Caffrey, Leah M; deRonde, Brittany M; Minter, Lisa M; Tew, Gregory N

2016-10-10

A fundamental understanding of how polymer structure impacts internalization and delivery of biologically relevant cargoes, particularly small interfering ribonucleic acid (siRNA), is of critical importance to the successful design of improved delivery reagents. Herein we report the use of ring-opening metathesis polymerization (ROMP) methods to synthesize two series of guanidinium-rich protein transduction domain mimics (PTDMs): one based on an imide scaffold that contains one guanidinium moiety per repeat unit, and another based on a diester scaffold that contains two guanidinium moieties per repeat unit. By varying both the degree of polymerization and, in effect, the relative number of cationic charges in each PTDM, the performances of the two ROMP backbones for siRNA internalization were evaluated and compared. Internalization of fluorescently labeled siRNA into Jurkat T cells demonstrated that fluorescein isothiocyanate (FITC)-siRNA internalization had a charge content dependence, with PTDMs containing approximately 40 to 60 cationic charges facilitating the most internalization. Despite this charge content dependence, the imide scaffold yielded much lower viabilities in Jurkat T cells than the corresponding diester PTDMs with similar numbers of cationic charges, suggesting that the diester scaffold is preferred for siRNA internalization and delivery applications. These developments will not only improve our understanding of the structural factors necessary for optimal siRNA internalization, but will also guide the future development of optimized PTDMs for siRNA internalization and delivery.

Effect of a prehop on the muscle-tendon interaction during vertical jumps.

PubMed

Aeles, Jeroen; Lichtwark, Glen; Peeters, Dries; Delecluse, Christophe; Jonkers, Ilse; Vanwanseele, Benedicte

2018-05-01

Many movements use stretch-shortening cycles of a muscle-tendon unit (MTU) for storing and releasing elastic energy. The required stretching of medial gastrocnemius (MG) tendinous tissue during jumps, however, requires large length changes of the muscle fascicles because of the lack of MTU length changes. This has a negative impact on the force-generating capacity of the muscle fascicles. The purpose of this study was to induce a MG MTU stretch before shortening by adding a prehop to the squat jump. Eleven well-trained athletes specialized in jumping performed a prehop squat jump (PHSJ) and a standard squat jump (SSJ). Kinematic data were collected using a 3D motion capture system and were used in a musculoskeletal model to calculate MTU lengths. B-mode ultrasonography of the MG was used to measure fascicle length and pennation angle during the jumps. By combining the muscle-tendon unit lengths, fascicle lengths, and pennation angles, the stretch and recoil of the series elastic element of MG were calculated using a simple geometric muscle-tendon model. Our results show less length changes of the muscle fascicles during the upward motion and lower maximal shortening velocities, increasing the moment-generating capacity of the plantar flexors, reflected in the higher ankle joint moment in the PHSJ compared with the SSJ. Although muscle-tendon interaction during the PHSJ was more optimal, athletes were not able to increase their jump height compared with the SSJ. NEW & NOTEWORTHY This is the first study that aimed to improve the muscle-tendon interaction in squat jumping. We effectively introduced a stretch to the medial gastrocnemius muscle-tendon unit resulting in lower maximal shortening velocities and thus an increase in the plantar flexor force-generating capacity, reflected in the higher ankle joint moment in the prehop squat jump compared with the standard squat jump. Here, we demonstrate an effective method for mechanical optimization of the muscle-tendon interaction in the medial gastrocnemius during squat jumping.

Surface tension of droplets and Tolman lengths of real substances and mixtures from density functional theory

NASA Astrophysics Data System (ADS)

Rehner, Philipp; Gross, Joachim

2018-04-01

The curvature dependence of interfacial properties has been discussed extensively over the last decades. After Tolman published his work on the effect of droplet size on surface tension, where he introduced the interfacial property now known as Tolman length, several studies were performed with varying results. In recent years, however, some consensus has been reached about the sign and magnitude of the Tolman length of simple model fluids. In this work, we re-examine Tolman's equation and how it relates the Tolman length to the surface tension and we apply non-local classical density functional theory (DFT) based on the perturbed chain statistical associating fluid theory (PC-SAFT) to characterize the curvature dependence of the surface tension of real fluids as well as mixtures. In order to obtain a simple expression for the surface tension, we use a first-order expansion of the Tolman length as a function of droplet radius Rs, as δ(Rs) = δ0 + δ1/Rs, and subsequently expand Tolman's integral equation for the surface tension, whereby a second-order expansion is found to give excellent agreement with the DFT result. The radius-dependence of the surface tension of increasingly non-spherical substances is studied for n-alkanes, up to icosane. The infinite diameter Tolman length is approximately δ0 = -0.38 Å at low temperatures. For more strongly non-spherical substances and for temperatures approaching the critical point, however, the infinite diameter Tolman lengths δ0 turn positive. For mixtures, even if they contain similar molecules, the extrapolated Tolman length behaves strongly non-ideal, implying a qualitative change of the curvature behavior of the surface tension of the mixture.

Cavity length dependence of mode beating in passively Q-switched Nd-solid state lasers

NASA Astrophysics Data System (ADS)

Zameroski, Nathan D.; Wanke, Michael; Bossert, David

2013-03-01

The temporal intensity profile of pulse(s) from passively Q-switched and passively Q-switched mode locked (QSML) solid-state lasers is known to be dependent on cavity length. In this work, the pulse width, modulation depth, and beat frequencies of a Nd:Cr:GSGG laser using a Cr+4:YAG passive Q-switch are investigated as function cavity length. Measured temporal widths are linearly correlated with cavity length but generally 3-5 ns larger than theoretical predictions. Some cavity lengths exhibit pulse profiles with no modulation while other lengths exhibit complete amplitude modulation. The observed beat frequencies at certain cavity lengths cannot be accounted for with passively QSML models in which the pulse train repetition rate is τRT-1, τRT= round-trip time. They can be explained, however, by including coupled cavity mode-locking effects. A theoretical model developed for a two section coupled cavity semiconductor laser is adapted to a solid-state laser to interpret measured beat frequencies. We also numerically evaluate the temporal criterion required to achieve temporally smooth Q-switched pulses, versus cavity length and pump rate. We show that in flash lamp pumped systems, the difference in buildup time between longitudinal modes is largely dependent on the pump rate. In applications where short pulse delay is important, the pumping rate may limit the ability to achieve temporally smooth pulses in passively Q-switched lasers. Simulations support trends in experimental data. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Surface tension of droplets and Tolman lengths of real substances and mixtures from density functional theory.

PubMed

Rehner, Philipp; Gross, Joachim

2018-04-28

The curvature dependence of interfacial properties has been discussed extensively over the last decades. After Tolman published his work on the effect of droplet size on surface tension, where he introduced the interfacial property now known as Tolman length, several studies were performed with varying results. In recent years, however, some consensus has been reached about the sign and magnitude of the Tolman length of simple model fluids. In this work, we re-examine Tolman's equation and how it relates the Tolman length to the surface tension and we apply non-local classical density functional theory (DFT) based on the perturbed chain statistical associating fluid theory (PC-SAFT) to characterize the curvature dependence of the surface tension of real fluids as well as mixtures. In order to obtain a simple expression for the surface tension, we use a first-order expansion of the Tolman length as a function of droplet radius R s , as δ(R s ) = δ 0 + δ 1 /R s , and subsequently expand Tolman's integral equation for the surface tension, whereby a second-order expansion is found to give excellent agreement with the DFT result. The radius-dependence of the surface tension of increasingly non-spherical substances is studied for n-alkanes, up to icosane. The infinite diameter Tolman length is approximately δ 0 = -0.38 Å at low temperatures. For more strongly non-spherical substances and for temperatures approaching the critical point, however, the infinite diameter Tolman lengths δ 0 turn positive. For mixtures, even if they contain similar molecules, the extrapolated Tolman length behaves strongly non-ideal, implying a qualitative change of the curvature behavior of the surface tension of the mixture.

Effective ergodicity breaking in an exclusion process with varying system length

NASA Astrophysics Data System (ADS)

Schultens, Christoph; Schadschneider, Andreas; Arita, Chikashi

2015-09-01

Stochastic processes of interacting particles in systems with varying length are relevant e.g. for several biological applications. We try to explore what kind of new physical effects one can expect in such systems. As an example, we extend the exclusive queueing process that can be viewed as a one-dimensional exclusion process with varying length, by introducing Langmuir kinetics. This process can be interpreted as an effective model for a queue that interacts with other queues by allowing incoming and leaving of customers in the bulk. We find surprising indications for breaking of ergodicity in a certain parameter regime, where the asymptotic growth behavior depends on the initial length. We show that a random walk with site-dependent hopping probabilities exhibits qualitatively the same behavior.

Cochlear implants and medical tourism.

PubMed

McKinnon, Brian J; Bhatt, Nishant

2010-09-01

To compare the costs of medical tourism in cochlear implant surgery performed in India as compared to the United States. In addition, the cost savings of obtaining cochlear implant surgery in India were compare d to those of other surgical interventions obtained as a medical tourist. Searches were conducted on Medline and Google using the search terms: 'medical tourism', 'medical offshoring', 'medical outsourcing', 'cochlear implants' and 'cochlear implantation'. The information regarding cost of medical treatment was obtained from personal communication with individuals familiar with India's cochlear implantation medical tourism industry. The range of cost depended on length of stay as well as the device chosen. Generally the cost, inclusive of travel, surgery and device, was in the range of $21,000-30,000, as compared to a cost range of $40,000-$60,000 in the US. With the escalating cost of healthcare in the United States, it is not surprising that some patients would seek to obtain surgical care overseas at a fraction of the cost. Participants in medical tourism often have financial resources, but lack health insurance coverage. While cardiovascular and orthopedic surgery performed outside the United States in India at centers that cater to medical tourists are often performed at one-quarter to one-third of the cost that would have been paid in the United States, the cost differential for cochlear implants is not nearly as favorable.

Automated detection of physiologic deterioration in hospitalized patients

PubMed Central

Evans, R Scott; Kuttler, Kathryn G; Simpson, Kathy J; Howe, Stephen; Crossno, Peter F; Johnson, Kyle V; Schreiner, Misty N; Lloyd, James F; Tettelbach, William H; Keddington, Roger K; Tanner, Alden; Wilde, Chelbi; Clemmer, Terry P

2015-01-01

Objective Develop and evaluate an automated case detection and response triggering system to monitor patients every 5 min and identify early signs of physiologic deterioration. Materials and methods A 2-year prospective, observational study at a large level 1 trauma center. All patients admitted to a 33-bed medical and oncology floor (A) and a 33-bed non-intensive care unit (ICU) surgical trauma floor (B) were monitored. During the intervention year, pager alerts of early physiologic deterioration were automatically sent to charge nurses along with access to a graphical point-of-care web page to facilitate patient evaluation. Results Nurses reported the positive predictive value of alerts was 91–100% depending on erroneous data presence. Unit A patients were significantly older and had significantly more comorbidities than unit B patients. During the intervention year, unit A patients had a significant increase in length of stay, more transfers to ICU (p = 0.23), and significantly more medical emergency team (MET) calls (p = 0.0008), and significantly fewer died (p = 0.044) compared to the pre-intervention year. No significant differences were found on unit B. Conclusions We monitored patients every 5 min and provided automated pages of early physiologic deterioration. This before–after study found a significant increase in MET calls and a significant decrease in mortality only in the unit with older patients with multiple comorbidities, and thus further study is warranted to detect potential confounding. Moreover, nurses reported the graphical alerts provided information needed to quickly evaluate patients, and they felt more confident about their assessment and more comfortable requesting help. PMID:25164256

Spatial distribution of surface action potentials generated by individual motor units in the human biceps brachii muscle.

PubMed

Rodriguez-Falces, Javier; Negro, Francesco; Gonzalez-Izal, Miriam; Farina, Dario

2013-08-01

This study analyses the spatial distribution of individual motor unit potentials (MUPs) over the skin surface and the influence of motor unit depth and recording configuration on this distribution. Multichannel surface (13×5 electrode grid) and intramuscular (wire electrodes inserted with needles of lengths 15 and 25mm) electromyographic (EMG) signals were concurrently recorded with monopolar derivations from the biceps brachii muscle of 10 healthy subjects during 60-s isometric contractions at 20% of the maximum torque. Multichannel monopolar MUPs of the target motor unit were obtained by spike-triggered averaging of the surface EMG. Amplitude and frequency characteristics of monopolar and bipolar MUPs were calculated for locations along the fibers' direction (longitudinal), and along the direction perpendicular (transverse) to the fibers. In the longitudinal direction, monopolar and bipolar MUPs exhibited marked amplitude changes that extended for 16-32mm and 16-24mm over the innervation and tendon zones, respectively. The variation of monopolar and bipolar MUP characteristics was not symmetrical about the innervation zone. Motor unit depth had a considerable influence on the relative longitudinal variation of amplitude for monopolar MUPs, but not for bipolar MUPs. The transverse extension of bipolar MUPs ranged between 24 and 32mm, whereas that of monopolar MUPs ranged between 72 and 96mm. The mean power spectral frequency of surface MUPs was highly dependent on the transverse electrode location but not on depth. This study provides a basis for the interpretation of the contribution of individual motor units to the interference surface EMG signal. Copyright © 2013 Elsevier Ltd. All rights reserved.

pKa prediction from an ab initio bond length: part 3--benzoic acids and anilines.

PubMed

Harding, A P; Popelier, P L A

2011-06-21

The prediction of pK(a) from a single ab initio bond length has been extended to provide equations for benzoic acids and anilines. The HF/6-31G(d) level of theory is used for all geometry optimisations. Similarly to phenols (Part 2 of this series of publications), the meta-/para-substituted benzoic acids can be predicted from a single model constructed from one bond length. This model had an impressive RMSEP of 0.13 pK(a) units. The prediction of ortho-substituted benzoic acids required the identification of high-correlation subsets, where the compounds in the same subset have at least one of the same (e.g. halogens, hydroxy) ortho substituent. Two pK(a) equations are provided for o-halogen benzoic acids and o-hydroxybenzoic acids, where the RMSEP values are 0.19 and 0.15 pK(a) units, respectively. Interestingly, the bond length that provided the best model differed between these two high-correlation subsets. This demonstrates the importance of investigating the most predictive bond length, which is not necessarily the bond involving the acid hydrogen. Three high-correlation subsets were identified for the ortho-substituted anilines. These were o-halogen, o-nitro and o-alkyl-substituted aniline high-correlation subsets, where the RMSEP ranged from 0.23 to 0.44 pK(a) units. The RMSEP for the meta-/para-substituted aniline model was 0.54 pK(a) units. This value exceeded our threshold of 0.50 pK(a) units and was higher than both the m-/p-benzoic acids in this work and the m-/p-phenols (RMSEP = 0.43) of Part 2. Constructing two separate models for the meta- and para- substituted anilines, where RMSEP values of 0.63 and 0.33 pK(a) units were obtained respectively, revealed it was the meta-substituted anilines that caused the large RMSEP value. For unknown reasons the RMSEP value increased with the addition of a further twenty meta-substituted anilines to this model. The C-N bond always produced the best correlations with pK(a) for all the high-correlation subsets. A higher level of theory and an ammonia probe improved the statistics only marginally for the hydroxybenzoic acid high-correlation subsets.

In Vivo Imaging of Human Sarcomere Twitch Dynamics in Individual Motor Units

PubMed Central

Sanchez, Gabriel N.; Sinha, Supriyo; Liske, Holly; Chen, Xuefeng; Nguyen, Viet; Delp, Scott L.; Schnitzer, Mark J.

2017-01-01

SUMMARY Motor units comprise a pre-synaptic motor neuron and multiple post-synaptic muscle fibers. Many movement disorders disrupt motor unit contractile dynamics and the structure of sarcomeres, skeletal muscle’s contractile units. Despite the motor unit’s centrality to neuromuscular physiology, no extant technology can image sarcomere twitch dynamics in live humans. We created a wearable microscope equipped with a microendoscope for minimally invasive observation of sarcomere lengths and contractile dynamics in any major skeletal muscle. By electrically stimulating twitches via the microendoscope and visualizing the sarcomere displacements, we monitored single motor unit contractions in soleus and vastus lateralis muscles of healthy individuals. Control experiments verified that these evoked twitches involved neuromuscular transmission and faithfully reported muscle force generation. In post-stroke patients with spasticity of the biceps brachii, we found involuntary microscopic contractions and sarcomere length abnormalities. The wearable microscope facilitates exploration of many basic and disease-related neuromuscular phenomena never visualized before in live humans. PMID:26687220

Similar and functionally typical kinematic reaching parameters in 7- and 15-month-old in utero cocaine-exposed and unexposed infants.

PubMed

Tronick, E Z; Fetters, Linda; Olson, Karen L; Chen, Yuping

2004-04-01

This study examined the effects of intrauterine cocaine exposure on the reaches of 19 exposed and 15 unexposed infants at 7 and 15 months using kinematic measures. Infants sat at a table and reached for a rattle, a toy doll, and a chair. Videotaped reaches were digitized using the Peak Performance system. Kinematic movement variables were extracted (e.g., reach duration, peak velocity, movement units, path length) and ratios computed (e.g., path length divided by number of movement units). Regardless of exposure status, reaches of older infants were faster, more direct, had fewer movement units, and covered more distance with the first movement unit. Exposed infants covered more distance per movement unit than unexposed infants, but there were no other significant differences. Reaches of exposed and unexposed infants were essentially similar. Importantly, reach parameters for these high-risk infants were similar to reach parameters for infants at lower social and biological risk. Copyright 2004 Wiley Periodicals, Inc.

SSmiles.

ERIC Educational Resources Information Center

Sunal, Dennis W., Ed.; Tracy, Dyanne M., Ed.

1992-01-01

Presents activities to supplement lessons on length and mass measurement or as part of a unit on atoms or orders of magnitude. Provides a lesson plan using aluminum foil to estimate unit measures, calculate the foil's thickness, and do an atom count. (MDH)

Length-dependent corrosion behavior, Ni2+ release, cytocompatibility, and antibacterial ability of Ni-Ti-O nanopores anodically grown on biomedical NiTi alloy.

PubMed

Hang, Ruiqiang; Liu, Yanlian; Bai, Long; Zhang, Xiangyu; Huang, Xiaobo; Jia, Husheng; Tang, Bin

2018-08-01

In the present work, nickel-titanium-oxygen nanopores with different length (0.55-114 μm) were anodically grown on nearly equiatomic nickel-titanium (NiTi) alloy. Length-dependent corrosion behavior, nickel ion (Ni 2+ ) release, cytocompatibility, and antibacterial ability were investigated by electrochemical, analytical chemistry, and biological methods. The results show constructing nanoporous structure on the NiTi alloy improve its corrosion resistance. However, the anodized samples release more Ni 2+ than that of the bare NiTi alloy, suggesting chemical dissolution of the nanopores rather than electrochemical corrosion governs the Ni 2+ release. In addition, the Ni 2+ release amount increases with nanopore length. The anodized samples show good cytocompatibility when the nanopore length is <11 μm. Encouragingly, the length scale covers the one (1-11 μm) that the nanopores showing favorable antibacterial ability. Consequently, the nanopores with length in the range of 1-11 μm are promising as coatings of biomedical NiTi alloy for anti-infection, drug delivery, and other desirable applications. Copyright © 2018 Elsevier B.V. All rights reserved.

46 CFR 401.400 - Calculation of pilotage units and determination of weighting factor.

Code of Federal Regulations, 2010 CFR

2010-10-01

... weighting factor. 401.400 Section 401.400 Shipping COAST GUARD (GREAT LAKES PILOTAGE), DEPARTMENT OF... § 401.400 Calculation of pilotage units and determination of weighting factor. The equivalent pilotage... meters) Pilot Unit=(Length×Breadth×Depth)/10,000 (measured in feet) (b) Weighting factor table: Range of...

75 FR 74674 - Updates to Vessel Inspection Fees

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-01

... Certificate of Inspection and foreign tankships and mobile offshore drilling units required to maintain a... offshore drilling units trading in U.S. ports. Subpart 2.10 also sets forth fees for inspections conducted...: Length not greater than 200 feet 1,435 More than 200 feet 2,550 Mobile Offshore Drilling Units (MODUs...

23 CFR 658.23 - LCV freeze; cargo-carrying unit freeze.

Code of Federal Regulations, 2014 CFR

2014-04-01

... allow the operation on the NN of any CMV combination with two or more cargo-carrying units (not... before June 1, 1991; or (ii) The length of the cargo-carrying units of those CMV combinations, by...) Notwithstanding paragraph (a)(2) of this section, the following CMV combinations with two or more cargo-carrying...

23 CFR 658.23 - LCV freeze; cargo-carrying unit freeze.

Code of Federal Regulations, 2013 CFR

2013-04-01

... allow the operation on the NN of any CMV combination with two or more cargo-carrying units (not... before June 1, 1991; or (ii) The length of the cargo-carrying units of those CMV combinations, by...) Notwithstanding paragraph (a)(2) of this section, the following CMV combinations with two or more cargo-carrying...

23 CFR 658.23 - LCV freeze; cargo-carrying unit freeze.

Code of Federal Regulations, 2011 CFR

2011-04-01

... allow the operation on the NN of any CMV combination with two or more cargo-carrying units (not... before June 1, 1991; or (ii) The length of the cargo-carrying units of those CMV combinations, by...) Notwithstanding paragraph (a)(2) of this section, the following CMV combinations with two or more cargo-carrying...

23 CFR 658.23 - LCV freeze; cargo-carrying unit freeze.

Code of Federal Regulations, 2012 CFR

2012-04-01

... allow the operation on the NN of any CMV combination with two or more cargo-carrying units (not... before June 1, 1991; or (ii) The length of the cargo-carrying units of those CMV combinations, by...) Notwithstanding paragraph (a)(2) of this section, the following CMV combinations with two or more cargo-carrying...

Decision Making. Level Two/Three. Career Guidance.

ERIC Educational Resources Information Center

Cooper, Irene; And Others

Materials contained in this career guidance unit are designed to provide the seven-, eight-, or nine-year-old student with a framework of logical steps for decision making and problem solving. The seventeen activities included in the unit vary in length from thirty to sixty minutes; the entire unit requires approximately ten hours of instructional…

Superconducting Cavity Development for Free Electron Lasers.

DTIC Science & Technology

1986-06-30

effects have been modeled extensively using the code PARMELA, including finite space charge . The conflict is resolved through the use of harmonically...depends on the specifics of how the whole accelerator is run, i.e., bunch length, interpulse spacing , macrobunch length, charge per bunch, external...this indicates that the bunch length should be as long as possible. 2.4 OPTIMUM BUNCH LENGTH 20 Although wakefield, HOM excitation and space charge

Anomalous Flexural Behaviors of Microtubules

PubMed Central

Liu, Xiaojing; Zhou, Youhe; Gao, Huajian; Wang, Jizeng

2012-01-01

Apparent controversies exist on whether the persistence length of microtubules depends on its contour length. This issue is particularly challenging from a theoretical point of view due to the tubular structure and strongly anisotropic material property of microtubules. Here we adopt a higher order continuum orthotropic thin shell model to study the flexural behavior of microtubules. Our model overcomes some key limitations of a recent study based on a simplified anisotropic shell model and results in a closed-form solution for the contour-length-dependent persistence length of microtubules, with predictions in excellent agreement with experimental measurements. By studying the ratio between their contour and persistence lengths, we find that microtubules with length at ∼1.5 μm show the lowest flexural rigidity, whereas those with length at ∼15 μm show the highest flexural rigidity. This finding may provide an important theoretical basis for understanding the mechanical structure of mitotic spindles during cell division. Further analysis on the buckling of microtubules indicates that the critical buckling load becomes insensitive to the tube length for relatively short microtubules, in drastic contrast to the classical Euler buckling. These rich flexural behaviors of microtubules are of profound implication for many biological functions and biomimetic molecular devices. PMID:22768935

Estimating the spin diffusion length and the spin Hall angle from spin pumping induced inverse spin Hall voltages

NASA Astrophysics Data System (ADS)

Roy, Kuntal

2017-11-01

There exists considerable confusion in estimating the spin diffusion length of materials with high spin-orbit coupling from spin pumping experiments. For designing functional devices, it is important to determine the spin diffusion length with sufficient accuracy from experimental results. An inaccurate estimation of spin diffusion length also affects the estimation of other parameters (e.g., spin mixing conductance, spin Hall angle) concomitantly. The spin diffusion length for platinum (Pt) has been reported in the literature in a wide range of 0.5-14 nm, and in particular it is a constant value independent of Pt's thickness. Here, the key reasonings behind such a wide range of reported values of spin diffusion length have been identified comprehensively. In particular, it is shown here that a thickness-dependent conductivity and spin diffusion length is necessary to simultaneously match the experimental results of effective spin mixing conductance and inverse spin Hall voltage due to spin pumping. Such a thickness-dependent spin diffusion length is tantamount to the Elliott-Yafet spin relaxation mechanism, which bodes well for transitional metals. This conclusion is not altered even when there is significant interfacial spin memory loss. Furthermore, the variations in the estimated parameters are also studied, which is important for technological applications.

Design-of-experiments to Reduce Life-cycle Costs in Combat Aircraft Inlets

NASA Technical Reports Server (NTRS)

Anderson, Bernhard H.; Baust, Henry D.; Agrell, Johan

2003-01-01

It is the purpose of this study to demonstrate the viability and economy of Design- of-Experiments (DOE), to arrive at micro-secondary flow control installation designs that achieve optimal inlet performance for different mission strategies. These statistical design concepts were used to investigate the properties of "low unit strength" micro-effector installation. "Low unit strength" micro-effectors are micro-vanes, set a very low angle-of incidence, with very long chord lengths. They are designed to influence the neat wall inlet flow over an extended streamwise distance. In this study, however, the long chord lengths were replicated by a series of short chord length effectors arranged in series over multiple bands of effectors. In order to properly evaluate the performance differences between the single band extended chord length installation designs and the segmented multiband short chord length designs, both sets of installations must be optimal. Critical to achieving optimal micro-secondary flow control installation designs is the understanding of the factor interactions that occur between the multiple bands of micro-scale vane effectors. These factor interactions are best understood and brought together in an optimal manner through a structured DOE process, or more specifically Response Surface Methods (RSM).

Magnetic exchange coupling through superconductors: A trilayer study

NASA Astrophysics Data System (ADS)

Sá de Melo, C. A.

2000-11-01

The possibility of magnetic exchange coupling between two ferromagnets (F) separated by a superconductor (S) spacer is analyzed using the functional integral method. For this coupling to occur three prima facie conditions need to be satisfied. First, an indirect exchange coupling between the ferromagnets must exist when the superconductor is in its normal state. Second, superconductivity must not be destroyed due to the proximity to ferromagnetic boundaries. Third, roughness of the F/S interfaces must be small. Under these conditions, when the superconductor is cooled to below its critical temperature, the magnetic coupling changes. The appearance of the superconducting gap introduces a new length scale (the coherence length of the superconductor) and modifies the temperature dependence of the indirect exchange coupling existent in the normal state. The magnetic coupling is oscillatory both above and below the the critical temperature of the superconductor, as well as strongly temperature-dependent. However, at low temperatures the indirect exchange coupling decay length is controlled by the coherence length of the superconductor, while at temperatures close to and above the critical temperature of the superconductor the magnetic coupling decay length is controlled by the thermal length.

Metric System Resource Units = Unidades de Trabajo del Sistema Metrico Decimal. K-12. Project C.A.M.B.I.O., Changing Attitudes towards Metrics for Bilingual Instruction & Operations.

ERIC Educational Resources Information Center

Pulido, Josefina; Almendares, Simon

Four resource units are included in this document. For each, general objectives on knowledge and concepts, skills, and attitudes are given; content is outlined; and some suggestions for initiating the unit are listed. The first unit, on measuring length, provides six lesson plans, to teach about the meter, the smaller units of the meter, units…

Novel odd/even effect of alkylene chain length on the photopolymerizability of organogelators.

PubMed

Aoki, Ken'ichi; Kudo, Masabumi; Tamaoki, Nobuyuki

2004-10-28

[reaction: see text] Starting from diactylene diacarboxylic acids, we have synthesized a series of photopolymerizable organogelators that possess simple amide structures, different alkylene chain lengths, and either optically active or racemic 3,7-dimethyl-1-octylamine units. The alkylene chain length of these compounds exhibits a prominent odd/even effect with respect to the photopolymerization in the gel state and is accompanied by a stereostructural effect on the gelation ability.

Is scanning in probed order recall articulatory?

PubMed

Farrell, Simon; Lelièvre, Anna

2009-09-01

We consider how theories of serial recall might apply to other short-term memory tasks involving recall of order. In particular, we consider the possibility that when participants are cued to recall an item at an arbitrary position in a sequence, they covertly serially recall the list up to the cued position. One question is whether such "scanning" is articulatory in nature. Two experiments are presented in which the syllabic length of words preceding and following target positions were manipulated, to test the prediction of an articulatory-based mechanism that time to recall an item at a particular position will depend on the number of preceding long words. Although latency was dependent on target position, no word length effects on latency were observed. Additionally, the effects of word length on accuracy replicate recent demonstrations in serial recall that recall accuracy is dependent on the word length of all list items, not just that of target items, in line with distinctiveness assumptions. It is concluded that if scanning does occur, it is not carried out by covert or overt articulation.

Line length dependence of threshold current density and driving force in eutectic SnPb and SnAgCu solder electromigration

NASA Astrophysics Data System (ADS)

Yoon, Min-Seung; Ko, Min-Ku; Kim, Bit-Na; Kim, Byung-Joon; Park, Yong-Bae; Joo, Young-Chang

2008-04-01

The relationship between the threshold current density and the critical line length in eutectic SnPb and SnAgCu electromigrations were examined using solder lines with the various lengths ranging from 100to1000μm. When the electron wind-force was balanced by the back-stress gradient force, the net flux of electromigration is zero, at which the current density and line length are defined as the threshold current density and the critical length, respectively. It was found that in SnAgCu electromigration, the 1/L dependence on the threshold current density showed good agreement, whereas the threshold current densities of the eutectic SnPb deviated from the 1/L dependence. The balance between the electron wind-force and the back-stress gradient force was the main factor determining the threshold product of SnAgCu electromigration. On the other hand, in the case of eutectic SnPb, the chemical driving force is contributed as a back-flux force in addition to the back-stress gradient force. The existence of the chemical driving force was caused by the nonequilibrium Pb concentration inside the Pb-rich phases between the cathode and anode during the electromigration procedure.

Independence and mobility after infrainguinal lower limb bypass surgery for critical limb ischemia.

PubMed

Ambler, Graeme K; Dapaah, Andrew; Al Zuhir, Naail; Hayes, Paul D; Gohel, Manjit S; Boyle, Jonathan R; Varty, Kevin; Coughlin, Patrick A

2014-04-01

Critical limb ischemia (CLI) is a common condition associated with high levels of morbidity and mortality. Most work to date has focused on surgeon-oriented outcomes such as patency, but there is increasing interest in patient-oriented outcomes such as mobility and independence. This study was conducted to determine the effect of infrainguinal lower limb bypass surgery (LLBS) on postoperative mobility in a United Kingdom tertiary vascular surgery unit and to investigate causes and consequences of poor postoperative mobility. We collected data on all patients undergoing LLBS for CLI at our institution during a 3-year period and analyzed potential factors that correlated with poor postoperative mobility. During the study period, 93 index LLBS procedures were performed for patients with CLI. Median length of stay was 11 days (interquartile range, 11 days). The 12-month rates of graft patency, major amputation, and mortality were 75%, 9%, and 6%, respectively. Rates of dependence increased fourfold during the first postoperative year, from 5% preoperatively to 21% at 12 months. Predictors of poor postoperative mobility were female sex (P = .04) and poor postoperative mobility (P < .001), initially and at the 12-month follow-up. Patients with poor postoperative mobility had significantly prolonged hospital length of stay (15 vs 8 days; P < .001). Patients undergoing LLBS for CLI suffer significantly impaired postoperative mobility, and this is associated with prolonged hospital stay, irrespective of successful revascularization. Further work is needed to better predict patients who will benefit from revascularization and in whom a nonoperative strategy is optimal. Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Approximate sample sizes required to estimate length distributions

USGS Publications Warehouse

Miranda, L.E.

2007-01-01

The sample sizes required to estimate fish length were determined by bootstrapping from reference length distributions. Depending on population characteristics and species-specific maximum lengths, 1-cm length-frequency histograms required 375-1,200 fish to estimate within 10% with 80% confidence, 2.5-cm histograms required 150-425 fish, proportional stock density required 75-140 fish, and mean length required 75-160 fish. In general, smaller species, smaller populations, populations with higher mortality, and simpler length statistics required fewer samples. Indices that require low sample sizes may be suitable for monitoring population status, and when large changes in length are evident, additional sampling effort may be allocated to more precisely define length status with more informative estimators. ?? Copyright by the American Fisheries Society 2007.

7 CFR 28.304 - Original representation of American Pima cotton staple lengths.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Original representation of American Pima cotton staple... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.304 Original representation of American...

7 CFR 28.304 - Original representation of American Pima cotton staple lengths.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Original representation of American Pima cotton staple... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.304 Original representation of American...

7 CFR 28.304 - Original representation of American Pima cotton staple lengths.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Original representation of American Pima cotton staple... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.304 Original representation of American...

7 CFR 28.304 - Original representation of American Pima cotton staple lengths.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Original representation of American Pima cotton staple... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.304 Original representation of American...

7 CFR 28.304 - Original representation of American Pima cotton staple lengths.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Original representation of American Pima cotton staple... STANDARDS AND STANDARD CONTAINER REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Official Cotton Standards of the United States for Length of Staple § 28.304 Original representation of American...

Plantation thinning systems in the Southern United States

Treesearch

Bryce J. Stokes; William F. Watson

1996-01-01

This paper reviews southern pine management and thinning practices, describes three harvesting systems for thinning, and presents production and cost estimates, and utilization rates. The costs and product recoveries were developed from published sources using a spreadsheet analysis. Systems included tree-length, flail/chip, and cut-to-length. The estimated total...

SU-E-I-16: Scan Length Dependency of the Radial Dose Distribution in a Long Polyethylene Cylinder

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

Bakalyar, D; McKenney, S; Feng, W

Purpose: The area-averaged dose in the central plane of a long cylinder following a CT scan depends upon the radial dose distribution and the length of the scan. The ICRU/TG200 phantom, a polyethylene cylinder 30 cm in diameter and 60 cm long, was the subject of this study. The purpose was to develop an analytic function that could determine the dose for a scan length L at any point in the central plane of this phantom. Methods: Monte Carlo calculations were performed on a simulated ICRU/TG200 phantom under conditions of cylindrically symmetric conditions of irradiation. Thus, the radial dose distributionmore » function must be an even function that accounts for two competing effects: The direct beam makes its weakest contribution at the center while the scatter begins abruptly at the outer radius and grows as the center is approached. The scatter contribution also increases with scan length with the increase approaching its limiting value at the periphery faster than along the central axis. An analytic function was developed that fit the data and possessed these features. Results: Symmetry and continuity dictate a local extremum at the center which is a minimum for the ICRU/TG200 phantom. The relative depth of the minimum decreases as the scan length grows and an absolute maximum can occur between the center and outer edge of the cylinders. As the scan length grows, the relative dip in the center decreases so that for very long scan lengths, the dose profile is relatively flat. Conclusion: An analytic function characterizes the radial and scan length dependency of dose for long cylindrical phantoms. The function can be integrated with the results expressed in closed form. One use for this is to help determine average dose distribution over the central cylinder plane for any scan length.« less

Effect of base sequence on the DNA cross-linking properties of pyrrolobenzodiazepine (PBD) dimers

PubMed Central

Rahman, Khondaker M.; James, Colin H.; Thurston, David E.

2011-01-01

Pyrrolo[2,1-c][1,4]benzodiazepine (PBD) dimers are synthetic sequence-selective DNA minor-groove cross-linking agents that possess two electrophilic imine moieties (or their equivalent) capable of forming covalent aminal linkages with guanine C2-NH2 functionalities. The PBD dimer SJG-136, which has a C8–O–(CH2)3–O–C8′′ central linker joining the two PBD moieties, is currently undergoing phase II clinical trials and current research is focused on developing analogues of SJG-136 with different linker lengths and substitution patterns. Using a reversed-phase ion pair HPLC/MS method to evaluate interaction with oligonucleotides of varying length and sequence, we recently reported (JACS, 2009, 131, 13 756) that SJG-136 can form three different types of adducts: inter- and intrastrand cross-linked adducts, and mono-alkylated adducts. These studies have now been extended to include PBD dimers with a longer central linker (C8–O–(CH2)5–O–C8′), demonstrating that the type and distribution of adducts appear to depend on (i) the length of the C8/C8′-linker connecting the two PBD units, (ii) the positioning of the two reactive guanine bases on the same or opposite strands, and (iii) their separation (i.e. the number of base pairs, usually ATs, between them). Based on these data, a set of rules are emerging that can be used to predict the DNA–interaction behaviour of a PBD dimer of particular C8–C8′ linker length towards a given DNA sequence. These observations suggest that it may be possible to design PBD dimers to target specific DNA sequences. PMID:21427082

Length of stay benchmarks for inpatient rehabilitation after stroke.

PubMed

Meyer, Matthew; Britt, Eileen; McHale, Heather A; Teasell, Robert

2012-01-01

In Canada, no standardized benchmarks for length of stay (LOS) have been established for post-stroke inpatient rehabilitation. This paper describes the development of a severity specific median length of stay benchmarking strategy, assessment of its impact after one year of implementation in a Canadian rehabilitation hospital, and establishment of updated benchmarks that may be useful for comparison with other facilities across Canada. Patient data were retrospectively assessed for all patients admitted to a single post-acute stroke rehabilitation unit in Ontario, Canada between April 2005 and March 2008. Rehabilitation Patient Groups (RPGs) were used to establish stratified median length of stay benchmarks for each group that were incorporated into team rounds beginning in October 2009. Benchmark impact was assessed using mean LOS, FIM(®) gain, and discharge destination for each RPG group, collected prospectively for one year, compared against similar information from the previous calendar year. Benchmarks were then adjusted accordingly for future use. Between October 2009 and September 2010, a significant reduction in average LOS was noted compared to the previous year (35.3 vs. 41.2 days; p < 0.05). Reductions in LOS were noted in each RPG group including statistically significant reductions in 4 of the 7 groups. As intended, reductions in LOS were achieved with no significant reduction in mean FIM(®) gain or proportion of patients discharged home compared to the previous year. Adjusted benchmarks for LOS ranged from 13 to 48 days depending on the RPG group. After a single year of implementation, severity specific benchmarks helped the rehabilitation team reduce LOS while maintaining the same levels of functional gain and achieving the same rate of discharge to the community. © 2012 Informa UK, Ltd.

Persistence length of wormlike micelles composed of ionic surfactants: self-consistent-field predictions.

PubMed

Lauw, Y; Leermakers, F A M; Stuart, M A Cohen

2007-07-19

The persistence length of a wormlike micelle composed of ionic surfactants C(n)E(m)X(k) in an aqueous solvent is predicted by means of the self-consistent-field theory where C(n)E(m) is the conventional nonionic surfactant and X(k) is an additional sequence of k weakly charged (pH-dependent) segments. By considering a toroidal micelle at infinitesimal curvature, we evaluate the bending modulus of the wormlike micelle that corresponds to the total persistence length, consisting of an elastic/intrinsic and an electrostatic contribution. The total persistence length increases with pH and decreases with increasing background salt concentration. We estimate that the electrostatic persistence length l(p,e)(0) scales with respect to the Debye length kappa(-1) as l(p,e)(0) approximately kappa(-p) where p approximately 1.98 for wormlike micelles consisting of C(20)E(10)X(1) surfactants and p approximately 1.54 for wormlike micelles consisting of C(20)E(10)X(2) surfactants. The total persistence length l(p,t)(0) is a weak function of the head group length m but scales with the tail length n as l(p,t)(0) approximately n(x) where x approximately 2-2.6, depending on the corresponding head group length. Interestingly, l(p,t)(0) varies nonmonotonically with the number of charged groups k due to the opposing trends in the electrostatic and elastic bending rigidities upon variation of k.

A Pearson Random Walk with Steps of Uniform Orientation and Dirichlet Distributed Lengths

NASA Astrophysics Data System (ADS)

Le Caër, Gérard

2010-08-01

A constrained diffusive random walk of n steps in ℝ d and a random flight in ℝ d , which are equivalent, were investigated independently in recent papers (J. Stat. Phys. 127:813, 2007; J. Theor. Probab. 20:769, 2007, and J. Stat. Phys. 131:1039, 2008). The n steps of the walk are independent and identically distributed random vectors of exponential length and uniform orientation. Conditioned on the sum of their lengths being equal to a given value l, closed-form expressions for the distribution of the endpoint of the walk were obtained altogether for any n for d=1,2,4. Uniform distributions of the endpoint inside a ball of radius l were evidenced for a walk of three steps in 2D and of two steps in 4D. The previous walk is generalized by considering step lengths which have independent and identical gamma distributions with a shape parameter q>0. Given the total walk length being equal to 1, the step lengths have a Dirichlet distribution whose parameters are all equal to q. The walk and the flight above correspond to q=1. Simple analytical expressions are obtained for any d≥2 and n≥2 for the endpoint distributions of two families of walks whose q are integers or half-integers which depend solely on d. These endpoint distributions have a simple geometrical interpretation. Expressed for a two-step planar walk whose q=1, it means that the distribution of the endpoint on a disc of radius 1 is identical to the distribution of the projection on the disc of a point M uniformly distributed over the surface of the 3D unit sphere. Five additional walks, with a uniform distribution of the endpoint in the inside of a ball, are found from known finite integrals of products of powers and Bessel functions of the first kind. They include four different walks in ℝ3, two of two steps and two of three steps, and one walk of two steps in ℝ4. Pearson-Liouville random walks, obtained by distributing the total lengths of the previous Pearson-Dirichlet walks according to some specified probability law are finally discussed. Examples of unconstrained random walks, whose step lengths are gamma distributed, are more particularly considered.

Incentive spirometry decreases respiratory complications following major abdominal surgery.

PubMed

Westwood, K; Griffin, M; Roberts, K; Williams, M; Yoong, K; Digger, T

2007-12-01

Pulmonary complications are the leading cause of morbidity and mortality following major abdominal surgery. Chest physiotherapy aims to decrease the likelihood of these complications and hasten recovery. Exercises aimed at maximising inspiratory effort are the most beneficial for the patients. The incentive spirometer is a handheld device that patients use to achieve effective inspiration. In a nonrandomised pilot study of 263 patients we have found that the addition of the incentive spirometer, as part of an intensive post-operative physiotherapy programme, decreased the occurrence of pulmonary complications (6 vs 17%, p = 0.01) and length of stay on the surgical high dependency unit (3.1 vs 4 days p = 0.03). The two groups were comparable when age, sex, smoking history, the need for emergency surgery and post-operative analgesia were compared.

Epidermal Growth Factor-Dependent Transformation by a Human EGF Receptor Proto-Oncogene

NASA Astrophysics Data System (ADS)

Velu, Thierry J.; Beguinot, Laura; Vass, William C.; Willingham, Mark C.; Merlino, Glenn T.; Pastan, Ira; Lowy, Douglas R.

1987-12-01

The epidermal growth factor (EGF) receptor gene EGFR has been placed in a retrovirus vector to examine the growth properties of cells that experimentally overproduce a full-length EGF receptor. NIH 3T3 cells transfected with the viral DNA or infected with the corresponding rescued retrovirus developed a fully transformed phenotype in vitro that required both functional EGFR expression and the presence of EGF in the growth medium. Cells expressing 4 × 105 EGF receptors formed tumors in nude mice, while control cells did not. Therefore, the EGFR retrovirus, which had a titer on NIH 3T3 cells that was greater than 107 focus-forming units per milliliter, can efficiently transfer and express this gene, and increased numbers of EGF receptors can contribute to the transformed phenotype.

Structure, bonding nature, and binding energy of alkanethiolate on As-rich GaAs (001) surface: a density functional theory study.

PubMed

Voznyy, Oleksandr; Dubowski, Jan J

2006-11-30

Chemisorption of alkanethiols on As-rich GaAs (001) surface under a low coverage condition was studied using first principles density functional calculations in a periodic supercell approach. The thiolate adsorption site, tilt angle and its direction are dictated by the high directionality of As dangling bond and sulfur 3p orbital participating in bonding and steric repulsion of the first three CH2 units from the surface. Small charge transfer between thiolate and surface, strong dependence of total energy on tilt angle, and a relatively short length of 2.28 A of the S-As bond indicate the highly covalent nature of the bonding. Calculated binding energy of 2.1 eV is consistent with the available experimental data.

Effects of Surface Electron Doping and Substrate on the Superconductivity of Epitaxial FeSe Films.

PubMed

Zhang, W H; Liu, X; Wen, C H P; Peng, R; Tan, S Y; Xie, B P; Zhang, T; Feng, D L

2016-03-09

Superconductivity in FeSe is greatly enhanced in films grown on SrTiO3 substrates, although the mechanism behind remains unclear. Recently, surface potassium (K) doping has also proven able to enhance the superconductivity of FeSe. Here, by using scanning tunneling microscopy, we compare the K doping dependence of the superconductivity in FeSe films grown on two substrates: SrTiO3 (001) and graphitized SiC (0001). For thick films (20 unit cells (UC)), the optimized superconducting (SC) gaps are of similar size (∼9 meV) regardless of the substrate. However, when the thickness is reduced to a few UC, the optimized SC gap is increased up to ∼15 meV for films on SrTiO3, whereas it remains unchanged for films on SiC. This clearly indicates that the FeSe/SrTiO3 interface can further enhance the superconductivity, beyond merely doping electrons. Intriguingly, we found that this interface enhancement decays exponentially as the thickness increases, with a decay length of 2.4 UC, which is much shorter than the length scale for relaxation of the lattice strain, pointing to interfacial electron-phonon coupling as the likely origin.

Cohesive zone finite element analysis of crack initiation from a butt joint’s interface corner

DOE PAGES

Reedy, E. D.

2014-09-06

The Cohesive zone (CZ) fracture analysis techniques are used to predict the initiation of crack growth from the interface corner of an adhesively bonded butt joint. In this plane strain analysis, a thin linear elastic adhesive layer is sandwiched between rigid adherends. There is no preexisting crack in the problem analyzed, and the focus is on how the shape of the traction–separation (T–U) relationship affects the predicted joint strength. Unlike the case of a preexisting interfacial crack, the calculated results clearly indicate that the predicted joint strength depends on the shape of the T–U relationship. Most of the calculations usedmore » a rectangular T–U relationship whose shape (aspect ratio) is defined by two parameters: the interfacial strength σ* and the work of separation/unit area Γ. The principal finding of this study is that for a specified adhesive layer thickness, there is any number of σ*, Γ combinations that generate the same predicted joint strength. For each combination there is a corresponding CZ length. We developed an approximate CZ-like elasticity solution to show how such combinations arise and their connection with the CZ length.« less

Nucleon axial charge in (2+1)-flavor dynamical-lattice QCD with domain-wall fermions.

PubMed

Yamazaki, T; Aoki, Y; Blum, T; Lin, H W; Lin, M F; Ohta, S; Sasaki, S; Tweedie, R J; Zanotti, J M

2008-05-02

We present results for the nucleon axial charge g{A} at a fixed lattice spacing of 1/a=1.73(3) GeV using 2+1 flavors of domain wall fermions on size 16;{3} x 32 and 24;{3} x 64 lattices (L=1.8 and 2.7 fm) with length 16 in the fifth dimension. The length of the Monte Carlo trajectory at the lightest m_{pi} is 7360 units, including 900 for thermalization. We find finite volume effects are larger than the pion mass dependence at m{pi}=330 MeV. We also find a scaling with the single variable m{pi}L which can also be seen in previous two-flavor domain wall and Wilson fermion calculations. Using this scaling to eliminate the finite-volume effect, we obtain g{A}=1.20(6)(4) at the physical pion mass, m_{pi}=135 MeV, where the first and second errors are statistical and systematic. The observed finite-volume scaling also appears in similar quenched simulations, but disappear when V>or=(2.4 fm);{3}. We argue this is a dynamical quark effect.

Memory for tonal pitches: a music-length effect hypothesis.

PubMed

Akiva-Kabiri, Lilach; Vecchi, Tomaso; Granot, Roni; Basso, Demis; Schön, Daniele

2009-07-01

One of the most studied effects of verbal working memory (WM) is the influence of the length of the words that compose the list to be remembered. This work aims to investigate the nature of musical WM by replicating the word length effect in the musical domain. Length and rate of presentation were manipulated in a recognition task of tone sequences. Results showed significant effects for both factors (length and presentation rate) as well as their interaction, suggesting the existence of different strategies (e.g., chunking and rehearsal) for the immediate memory of musical information, depending upon the length of the sequences.

The use of 'arms-length' organizations for health system change in Ontario, Canada: some observations by insiders.

PubMed

Pink, George H; Leatt, Peggy

2003-01-01

During the past decade, there has been substantial health system reform in the United States, United Kingdom, New Zealand, and many other countries. For the most part, Canada has not pursued 'big bang' health system change but rather a variety of strategies to achieve incremental change. In this paper, we present the ways in which three arms-length organizations have been used by government to effect incremental system change in Ontario during the past several years. We observe that, (1) the influence of politics and political interference can be reduced through an arms-length organization; (2) an arms-length organization with the power to make decisions entails more political risk for government and encounters more scrutiny and criticism by providers and the media than an organization with the power to recommend only; (3) an arms-length organization with a limited lifespan faces more delaying tactics by adversely affected parties than an organization without a limited lifespan; (4) an arms-length organization with perceived influence may attract causes that are not related to its mandate; (5) the importance and difficulty of communicating complex information about system change to a wide variety of audiences cannot be overstated; (6) system change informed by the use of expert opinion encounters less provider resistance and may result in better decisions; and (7) the reputation of the Chair and the perceived competence and experience of the CEO are critical success factors in the success of an arms-length organization.

Effect of altering starting length and activation timing of muscle on fiber strain and muscle damage.

PubMed

Butterfield, Timothy A; Herzog, Walter

2006-05-01

Muscle strain injuries are some of the most frequent injuries in sports and command a great deal of attention in an effort to understand their etiology. These injuries may be the culmination of a series of subcellular events accumulated through repetitive lengthening (eccentric) contractions during exercise, and they may be influenced by a variety of variables including fiber strain magnitude, peak joint torque, and starting muscle length. To assess the influence of these variables on muscle injury magnitude in vivo, we measured fiber dynamics and joint torque production during repeated stretch-shortening cycles in the rabbit tibialis anterior muscle, at short and long muscle lengths, while varying the timing of activation before muscle stretch. We found that a muscle subjected to repeated stretch-shortening cycles of constant muscle-tendon unit excursion exhibits significantly different joint torque and fiber strains when the timing of activation or starting muscle length is changed. In particular, measures of fiber strain and muscle injury were significantly increased by altering activation timing and increasing the starting length of the muscle. However, we observed differential effects on peak joint torque during the cyclic stretch-shortening exercise, as increasing the starting length of the muscle did not increase torque production. We conclude that altering activation timing and muscle length before stretch may influence muscle injury by significantly increasing fiber strain magnitude and that fiber dynamics is a more important variable than muscle-tendon unit dynamics and torque production in influencing the magnitude of muscle injury.

Polariton resonances in multilayered piezoelectric superlattices

NASA Astrophysics Data System (ADS)

Piliposyan, D.

2018-04-01

Coupled electro-elastic SH waves propagating in a periodic piezoelectric finite-length superlattice with identical piezoelectric materials in a unit cell are considered in the framework of the full system of Maxwell’s electrodynamic equations. In the long wavelength region, coupling between electro-magnetic and elastic waves creates frequency band gaps. It is shown that for piezoelectric superlattice at acoustic frequencies, acousto-optic coupling gives rise to polariton behavior at wavelengths much larger than the length of the unit cell. The results of the paper may be useful in design of narrow band filters or multi-channel piezoelectric filters.

Application of CFD Modeling to Room Fire Growth on Walls

DTIC Science & Technology

2003-04-01

to each particle. For fires of other geometries, expressions must be available for representing the characteristic velocity and flame length , in the...burning time, z , is the flame length , ri,, is the selected particle rate. The velocity of the particles generally depends on their launch site. But if...over the characteristic flame length , We used R* = 0.05 or 20 cells over the characteristic flame length . In FDS 2.0 the stoichiometric mixture

Country-specific birth weight and length in type 1 diabetes high-risk HLA genotypes in combination with prenatal characteristics.

PubMed

Sterner, Y; Törn, C; Lee, H-S; Larsson, H; Winkler, C; McLeod, W; Lynch, K; Simell, O; Ziegler, A; Schatz, D; Hagopian, W; Rewers, M; She, J-X; Krischer, J P; Akolkar, B; Lernmark, A

2011-12-01

To examine the relationship between high-risk human leukocyte antigen (HLA) genotypes for type 1 diabetes and birth size in combination with prenatal ch aracteristics in different countries. Four high-risk HLA genotypes were enrolled in the Environmental determinants of Diabetes in the Young study newborn babies from the general population in Finland, Germany, Sweden and the United States. Stepwise regression analyses were used to adjust for country, parental physical characteristics and environmental factors during pregnancy. Regression analyses did not reveal differences in birth size between the four type 1 diabetes high-risk HLA genotypes. Compared with DQ 4/8 in each country, (1) DQ 2/2 children were heavier in the United States (P=0.028) mostly explained however, by parental weight; (2) DQ 2/8 (P=0.023) and DQ 8/8 (P=0.046) children were longer in Sweden independent of parents height and as well as (3) in the United States for DQ 2/8 (P=0.023), but again dependent on parental height. Children born with type 1 diabetes high-risk HLA genotypes have comparable birth size. Longitudinal follow-up of these children should reveal whether birth size differences between countries contribute to the risk for islet autoimmunity and type 1 diabetes.

Crystal structure, thermochromic and magnetic properties of organic-inorganic hybrid compound: (C7H7N2S)2CuCl4

NASA Astrophysics Data System (ADS)

Vishwakarma, Ashok K.; Kumari, Reema; Ghalsasi, Prasanna S.; Arulsamy, Navamoney

2017-08-01

The synthesis, thermal analysis, crystal structure and magnetic properties of (2-aminobenzothiazolium)2CuCl4, organic-inorganic hybrid compound, have been described. The compound crystallizes in the monoclinic space group P21/c with two formula units in a unit cell of dimensions a = 6.9522(4) Å, b = 9.6979(4) Å, c = 13.9633(6) Å, β = 97.849(3)° and volume 930.83(8) Å3 at 150(2) K. The structure consists of isolated nearly square planer [CuC14]2- units, with somewhat longer than normal Cusbnd Cl bond lengths [Cusbnd Cl (average) = 2.2711 Å]. The magnetic measurements of (2-aminobenzothiazolium)2CuCl4 using SQUID magnetometer show paramagnetic nature of the compound. Thermal measurements (TG-DTA and DSC) on this compound showed reversible phase transition at 83 °C. This transition is accompanied by the reversible change in colour of the prismatic crystal from green to dark brown, thermochromic behaviour. Temperature dependent EPR measurements on powdered sample ascertain change in coordination sphere around Cu(II) with shift in g|| = 2.150 and g⊥ = 2.071 at room temperature, typical of square planar, to g|| = 2.201 and g⊥ = 2.182 at 170 °C, typical of distorted tetrahedral geometry.

Comparison of aerodynamically and model-derived roughness lengths (zo) over diverse surfaces, central Mojave Desert, California, USA

USGS Publications Warehouse

MacKinnon, D.J.; Clow, G.D.; Tigges, R.K.; Reynolds, R.L.; Chavez, P.S.

2004-01-01

The vulnerability of dryland surfaces to wind erosion depends importantly on the absence or the presence and character of surface roughness elements, such as plants, clasts, and topographic irregularities that diminish wind speed near the surface. A model for the friction velocity ratio has been developed to account for wind sheltering by many different types of co-existing roughness elements. Such conditions typify a monitored area in the central Mojave Desert, California, that experiences frequent sand movement and dust emission. Two additional models are used to convert the friction velocity ratio to the surface roughness length (zo) for momentum. To calculate roughness lengths from these models, measurements were made at 11 sites within the monitored area to characterize the surface roughness element. Measurements included (1) the number of roughness species (e.g., plants, small-scale topography, clasts), and their associated heights and widths, (2) spacing among species, and (3) vegetation porosity (a measurement of the spatial distribution of woody elements of a plant). Documented or estimated values of drag coefficients for different species were included in the modeling. At these sites, wind-speed profiles were measured during periods of neutral atmospheric stability using three 9-m towers with three or four calibrated anemometers on each. Modeled roughness lengths show a close correspondence (correlation coefficient, 0.84-0.86) to the aerodynamically determined values at the field sites. The geometric properties of the roughness elements in the model are amenable to measurement at much higher temporal and spatial resolutions using remote-sensing techniques than can be accomplished through laborious ground-based methods. A remote-sensing approach to acquire values of the modeled roughness length is particularly important for the development of linked surface/atmosphere wind-erosion models sensitive to climate variability and land-use changes in areas such as the southwestern United States, where surface roughness has large spatial and temporal variations. ?? 2004 Elsevier B.V. All rights reserved.

The Influence of Item Calibration Error on Variable-Length Computerized Adaptive Testing

ERIC Educational Resources Information Center

Patton, Jeffrey M.; Cheng, Ying; Yuan, Ke-Hai; Diao, Qi

2013-01-01

Variable-length computerized adaptive testing (VL-CAT) allows both items and test length to be "tailored" to examinees, thereby achieving the measurement goal (e.g., scoring precision or classification) with as few items as possible. Several popular test termination rules depend on the standard error of the ability estimate, which in turn depends…

Positional signaling and expression of ENHANCER OF TRY AND CPC1 are tuned to increase root hair density in response to phosphate deficiency in Arabidopsis thaliana.

PubMed

Savage, Natasha; Yang, Thomas J W; Chen, Chung Ying; Lin, Kai-Lan; Monk, Nicholas A M; Schmidt, Wolfgang

2013-01-01

Phosphate (Pi) deficiency induces a multitude of responses aimed at improving the acquisition of Pi, including an increased density of root hairs. To understand the mechanisms involved in Pi deficiency-induced alterations of the root hair phenotype in Arabidopsis (Arabidopsis thaliana), we analyzed the patterning and length of root epidermal cells under control and Pi-deficient conditions in wild-type plants and in four mutants defective in the expression of master regulators of cell fate, CAPRICE (CPC), ENHANCER OF TRY AND CPC 1 (ETC1), WEREWOLF (WER) and SCRAMBLED (SCM). From this analysis we deduced that the longitudinal cell length of root epidermal cells is dependent on the correct perception of a positional signal ('cortical bias') in both control and Pi-deficient plants; mutants defective in the receptor of the signal, SCM, produced short cells characteristic of root hair-forming cells (trichoblasts). Simulating the effect of cortical bias on the time-evolving probability of cell fate supports a scenario in which a compromised positional signal delays the time point at which non-hair cells opt out the default trichoblast pathway, resulting in short, trichoblast-like non-hair cells. Collectively, our data show that Pi-deficient plants increase root hair density by the formation of shorter cells, resulting in a higher frequency of hairs per unit root length, and additional trichoblast cell fate assignment via increased expression of ETC1.

Positional Signaling and Expression of ENHANCER OF TRY AND CPC1 Are Tuned to Increase Root Hair Density in Response to Phosphate Deficiency in Arabidopsis thaliana

PubMed Central

Savage, Natasha; Yang, Thomas J. W.; Chen, Chung Ying; Lin, Kai-Lan; Monk, Nicholas A. M.; Schmidt, Wolfgang

2013-01-01

Phosphate (Pi) deficiency induces a multitude of responses aimed at improving the acquisition of Pi, including an increased density of root hairs. To understand the mechanisms involved in Pi deficiency-induced alterations of the root hair phenotype in Arabidopsis (Arabidopsis thaliana), we analyzed the patterning and length of root epidermal cells under control and Pi-deficient conditions in wild-type plants and in four mutants defective in the expression of master regulators of cell fate, CAPRICE (CPC), ENHANCER OF TRY AND CPC 1 (ETC1), WEREWOLF (WER) and SCRAMBLED (SCM). From this analysis we deduced that the longitudinal cell length of root epidermal cells is dependent on the correct perception of a positional signal (‘cortical bias’) in both control and Pi-deficient plants; mutants defective in the receptor of the signal, SCM, produced short cells characteristic of root hair-forming cells (trichoblasts). Simulating the effect of cortical bias on the time-evolving probability of cell fate supports a scenario in which a compromised positional signal delays the time point at which non-hair cells opt out the default trichoblast pathway, resulting in short, trichoblast-like non-hair cells. Collectively, our data show that Pi-deficient plants increase root hair density by the formation of shorter cells, resulting in a higher frequency of hairs per unit root length, and additional trichoblast cell fate assignment via increased expression of ETC1. PMID:24130712

La determination du rayon terrestre par J. PICARD en 1669 1671

NASA Astrophysics Data System (ADS)

Levallois, J. J.

1983-03-01

The French astronomer Jean PICARD (1620 1682) was certainly one of the leading scientists of his time. Friend of Huygens, of Hevelius, of Oldenburg, master of Römer, indefatigable traveller, he played a very important part in the development of positional astronomy and geodesy. - He first, had the idea of comparing the length units to a reproductible physical quantity, namely the length of the one second pendulum at Paris, and measured that length.

Temperature and composition dependence of short-range order and entropy, and statistics of bond length: the semiconductor alloy (GaN)(1-x)(ZnO)(x).

PubMed

Liu, Jian; Pedroza, Luana S; Misch, Carissa; Fernández-Serra, Maria V; Allen, Philip B

2014-07-09

We present total energy and force calculations for the (GaN)1-x(ZnO)x alloy. Site-occupancy configurations are generated from Monte Carlo (MC) simulations, on the basis of a cluster expansion model proposed in a previous study. Local atomic coordinate relaxations of surprisingly large magnitude are found via density-functional calculations using a 432-atom periodic supercell, for three representative configurations at x = 0.5. These are used to generate bond-length distributions. The configurationally averaged composition- and temperature-dependent short-range order (SRO) parameters of the alloys are discussed. The entropy is approximated in terms of pair distribution statistics and thus related to SRO parameters. This approximate entropy is compared with accurate numerical values from MC simulations. An empirical model for the dependence of the bond length on the local chemical environments is proposed.

Charge dependence of the plasma travel length in atmospheric-pressure plasma

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

Yambe, Kiyoyuki; Konda, Kohmei; Masuda, Seiya

Plasma plume is generated using a quartz tube, helium gas, and foil electrode by applying AC high voltage under the atmosphere. The plasma plume is released into the atmosphere from inside of the quartz tube and is seen as the continuous movement of the plasma bullet. The travel length of plasma bullet is defined from plasma energy and force due to electric field. The drift velocity of plasma bullet has the upper limit under atmospheric-pressure because the drift velocity is determined from the balance between electric field and resistive force due to collisions between plasma and air. The plasma plumemore » charge depends on the drift velocity. Consequently, in the laminar flow of helium gas flow state, the travel length of the plasma plume logarithmically depends on the plasma plume charge which changes with both the electric field and the resistive force.« less

Smooth muscle length adaptation and actin filament length: a network model of the cytoskeletal dysregulation.

PubMed

Silveira, Paulo S P; Fredberg, Jeffrey J

2005-10-01

Length adaptation of the airway smooth muscle cell is attributable to cytoskeletal remodeling. It has been proposed that dysregulated actin filaments may become longer in asthma, and that such elongation would prevent a parallel-to-series transition of contractile units, thus precluding the well-known beneficial effects of deep inspirations and tidal breathing. To test the potential effect that actin filament elongation could have in overall muscle mechanics, we present an extremely simple model. The cytoskeleton is represented as a 2-D network of links (contractile filaments) connecting nodes (adhesion plaques). Such a network evolves in discrete time steps by forming and dissolving links in a stochastic fashion. Links are formed by idealized contractile units whose properties are either those from normal or elongated actin filaments. Oscillations were then imposed on the network to evaluate both the effects of breathing and length adaptation. In response to length oscillation, a network with longer actin filaments showed smaller decreases of force, smaller increases in compliance, and higher shortening velocities. Taken together, these changes correspond to a network that is refractory to the effects of breathing and therefore approximates an asthmatic scenario. Thus, an extremely simple model seems to capture some relatively complex mechanics of airway smooth muscle, supporting the idea that dysregulation of actin filament length may contribute to excessive airway narrowing.

Programmable Pulse Generator

NASA Technical Reports Server (NTRS)

Rhim, W. K.; Dart, J. A.

1982-01-01

New pulse generator programmed to produce pulses from several ports at different pulse lengths and intervals and virtually any combination and sequence. Unit contains a 256-word-by-16-bit memory loaded with instructions either manually or by computer. Once loaded, unit operates independently of computer.

An ALMA study of the Orion Integral Filament. I. Evidence for narrow fibers in a massive cloud

NASA Astrophysics Data System (ADS)

Hacar, A.; Tafalla, M.; Forbrich, J.; Alves, J.; Meingast, S.; Grossschedl, J.; Teixeira, P. S.

2018-03-01

Aim. We have investigated the gas organization within the paradigmatic Integral Shape Filament (ISF) in Orion in order to decipher whether or not all filaments are bundles of fibers. Methods: We combined two new ALMA Cycle 3 mosaics with previous IRAM 30m observations to produce a high-dynamic range N2H+ (1-0) emission map of the ISF tracing its high-density material and velocity structure down to scales of 0.009 pc (or 2000 AU). Results: From the analysis of the gas kinematics, we identify a total of 55 dense fibers in the central region of the ISF. Independently of their location in the cloud, these fibers are characterized by transonic internal motions, lengths of 0.15 pc, and masses per unit length close to those expected in hydrostatic equilibrium. The ISF fibers are spatially organized forming a dense bundle with multiple hub-like associations likely shaped by the local gravitational potential. Within this complex network, the ISF fibers show a compact radial emission profile with a median FWHM of 0.035 pc systematically narrower than the previously proposed universal 0.1 pc filament width. Conclusions: Our ALMA observations reveal complex bundles of fibers in the ISF, suggesting strong similarities between the internal substructure of this massive filament and previously studied lower-mass objects. The fibers show identical dynamic properties in both low- and high-mass regions, and their widespread detection in nearby clouds suggests a preferred organizational mechanism of gas in which the physical fiber dimensions (width and length) are self-regulated depending on their intrinsic gas density. Combining these results with previous works in Musca, Taurus, and Perseus, we identify a systematic increase of the surface density of fibers as a function of the total mass per-unit-length in filamentary clouds. Based on this empirical correlation, we propose a unified star-formation scenario where the observed differences between low- and high-mass clouds, and the origin of clusters, emerge naturally from the initial concentration of fibers. The movie associated to Fig. 2 is available at http://https://www.aanda.orgThe data products of this work are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/610/A77

Minimization of Dependency Length in Written English

ERIC Educational Resources Information Center

Temperley, David

2007-01-01

Gibson's Dependency Locality Theory (DLT) [Gibson, E. 1998. "Linguistic complexity: locality of syntactic dependencies." "Cognition," 68, 1-76; Gibson, E. 2000. "The dependency locality theory: A distance-based theory of linguistic complexity." In A. Marantz, Y. Miyashita, & W. O'Neil (Eds.), "Image,…

Tendon Contraction After Cyclic Elongation Is an Age-Dependent Phenomenon: In Vitro and In Vivo Comparisons.

PubMed

Lavagnino, Michael; Bedi, Asheesh; Walsh, Christopher P; Sibilsky Enselman, Elizabeth R; Sheibani-Rad, Shahin; Arnoczky, Steven P

2014-06-01

Tendons are viscoelastic tissues that deform (elongate) in response to cyclic loading. However, the ability of a tendon to recover this elongation is unknown. Tendon length significantly increases after in vivo or in vitro cyclic loading, and the ability to return to its original length through a cell-mediated contraction mechanism is an age-dependent phenomenon. Controlled laboratory study. In vitro, rat tail tendon fascicles (RTTfs) from Sprague-Dawley rats of 3 age groups (1, 3, and 12 months) underwent 2% cyclic strain at 0.17 Hz for 2 hours, and the percentages of elongation were determined. After loading, the RTTfs were suspended for 3 days under tissue culture conditions and photographed daily to determine the amount of length contraction. In vivo, healthy male participants (n = 29; age, 19-49 years) had lateral, single-legged weightbearing radiographs taken of the knee at 60° of flexion immediately before, immediately after, and 24 hours after completing eccentric quadriceps loading exercises on the dominant leg to fatigue. Measurements of patellar tendon length were taken from the radiographs, and the percentages of tendon elongation and subsequent contraction were calculated. In vitro, cyclic loading increased the length of all RTTfs, with specimens from younger (1 and 3 months) rats demonstrating significantly greater elongation than those from older (12 months) rats (P = .009). The RTTfs contracted to their original length significantly faster (P < .001) and in an age-dependent fashion, with younger animals contracting faster. In vivo, repetitive eccentric loading exercises significantly increased patellar tendon length (P < .001). Patellar tendon length decreased 24 hours after exercises (P < .001) but did not recover completely (P < .001). There was a weak but significant (R (2) = 0.203, P = .014) linear correlation between the amount of tendon contraction and age, with younger participants (<30 years) demonstrating significantly more contraction (P = .014) at 24 hours than older participants (>30 years). Cyclic tendon loading results in a significant increase in tendon elongation under both in vitro and in vivo conditions. Tendons in both conditions demonstrated an incomplete return to their original length after 24 hours, and the extent of this return was age dependent. The age- and time-dependent contraction of tendons, elongated after repetitive loading, could result in transient alterations in the mechanobiological environment of tendon cells. This, in turn, could induce the onset of catabolic changes associated with the pathogenesis of tendinopathy. These results suggest the importance of allowing time for contraction between bouts of repetitive exercise and may explain why age is a predisposing factor in tendinopathy. © 2014 The Author(s).

Efficiency of specialist rehabilitation in reducing dependency and costs of continuing care for adults with complex acquired brain injuries

PubMed Central

Turner‐Stokes, L; Paul, S; Williams, H

2006-01-01

Objectives To examine functional outcomes from a rehabilitation programme and to compare two methods for evaluating cost efficiency of rehabilitation in patients with severe complex disability. Subjects and setting Two hundred and ninety seven consecutive admissions to a specialist inpatient rehabilitation unit following severe acquired brain injury. Methods Retrospective analysis of routinely collected data, including the Functional Independence Measure (FIM), Barthel Index, and Northwick Park Dependency Score and Care Needs Assessment (NPDS/NPCNA), which provides a generic estimation of dependency, care hours. and weekly cost of continuing care in the community. Patients were analysed in three groups according to dependency on admission: “low” (NPDS<10 (n = 83)); “medium” (NPDS10–24 (n = 112)); “high” (NPDS >24 (n = 102)). Results Mean length of stay (LOS) 112 (SD 66) days. All groups showed significant reduction in dependency between admission and discharge on all measures (paired t tests: p<0.001). Mean reduction in “weekly cost of care” was greatest in the high dependency group at £639 per week (95% CI 488 to 789)), as compared with the medium (£323/week (95% CI 217 to 428)), and low (£111/week (95% CI 42 to 179)) dependency groups. Despite their longer LOS, time taken to offset the initial cost of rehabilitation was only 16.3 months in the high dependency group, compared with 21.5 months (medium dependency) and 38.8 months (low dependency). FIM efficiency (FIM gain/LOS) appeared greatest in the medium dependency group (0.25), compared with the low (0.17) and high (0.16) dependency groups. Conclusions The NPDS/NPCNA detected changes in dependency potentially associated with substantial savings in the cost of ongoing care, especially in high dependency patients. Floor effects in responsiveness of the FIM may lead to underestimation of efficiency of rehabilitation in higher dependency patients. PMID:16614023

A systematic review and meta-analysis of acute stroke unit care: What’s beyond the statistical significance?

PubMed Central

2013-01-01

Background The benefits of stroke unit care in terms of reducing death, dependency and institutional care were demonstrated in a 2009 Cochrane review carried out by the Stroke Unit Trialists’ Collaboration. Methods As requested by the Belgian health authorities, a systematic review and meta-analysis of the effect of acute stroke units was performed. Clinical trials mentioned in the original Cochrane review were included. In addition, an electronic database search on Medline, Embase, the Cochrane Central Register of Controlled Trials, and Physiotherapy Evidence Database (PEDro) was conducted to identify trials published since 2006. Trials investigating acute stroke units compared to alternative care were eligible for inclusion. Study quality was appraised according to the criteria recommended by Scottish Intercollegiate Guidelines Network (SIGN) and the GRADE system. In the meta-analysis, dichotomous outcomes were estimated by calculating odds ratios (OR) and continuous outcomes were estimated by calculating standardized mean differences. The weight of a study was calculated based on inverse variance. Results Evidence from eight trials comparing acute stroke unit and conventional care (general medical ward) were retained for the main synthesis and analysis. The findings from this study were broadly in line with the original Cochrane review: acute stroke units can improve survival and independency, as well as reduce the chance of hospitalization and the length of inpatient stay. The improvement with stroke unit care on mortality was less conclusive and only reached borderline level of significance (OR 0.84, 95% CI 0.70 to 1.00, P = 0.05). This improvement became statistically non-significant (OR 0.87, 95% CI 0.74 to 1.03, P = 0.12) when data from two unpublished trials (Goteborg-Ostra and Svendborg) were added to the analysis. After further also adding two additional trials (Beijing, Stockholm) with very short observation periods (until discharge), the difference between acute stroke units and general medical wards on death remained statistically non-significant (OR 0.86, 95% CI 0.74 to 1.01, P = 0.06). Furthermore, based on figures reported by the clinical trials included in this study, a slightly higher proportion of patients became dependent after receiving care in stroke units than those treated in general medical wards – although the difference was not statistically significant. This result could have an impact on the future demand for healthcare services for individuals that survive a stroke but became dependent on their care-givers. Conclusions These findings demonstrate that a well-conducted meta-analysis can produce results that can be of value to policymakers but the choice of inclusion/exclusion criteria and outcomes in this context needs careful consideration. The financing of interventions such as stroke units that increase independency and reduce inpatient stays are worthwhile in a context of an ageing population with increasing care needs. One limitation of this study was the selection of trials published in only four languages: English, French, Dutch and German. This choice was pragmatic in the context of this study, where the objective was to support health authorities in their decision processes. PMID:24164771

Language Sample Analysis and Elicitation Technique Effects in Bilingual Children with and without Language Impairment

ERIC Educational Resources Information Center

Kapantzoglou, Maria; Fergadiotis, Gerasimos; Restrepo, M. Adelaida

2017-01-01

Purpose: This study examined whether the language sample elicitation technique (i.e., storytelling and story-retelling tasks with pictorial support) affects lexical diversity (D), grammaticality (grammatical errors per communication unit [GE/CU]), sentence length (mean length of utterance in words [MLUw]), and sentence complexity (subordination…

Impacts of oak pollen on allergic asthma in the United States and potential influence of future climate change

EPA Science Inventory

Oak pollen season length for moderate (RCP4.5) and severe climate change scenarios (RCP8.5) are estimated through 2090 using five climate models and published relationships between temperature, precipitation, and oak pollen season length. We calculated asthma ED visit counts asso...

Curricular Treatments of Length Measurement in the United States: Do They Address Known Learning Challenges?

ERIC Educational Resources Information Center

Smith, John P., III; Males, Lorraine M.; Dietiker, Leslie C.; Lee, KoSze; Mosier, Aaron

2013-01-01

Extensive research has shown that elementary students struggle to learn the basic principles of length measurement. However, where patterns of errors have been documented, the origins of students' difficulties have not been identified. This study investigated the hypothesis that written elementary mathematics curricula contribute to the…

76 FR 58681 - Migratory Bird Hunting; Final Frameworks for Late-Season Migratory Bird Hunting Regulations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-21

... shooting hours, the season lengths, the earliest opening and latest closing season dates, and hunting areas... amending 50 CFR part 20 to reflect seasons, limits, and shooting hours for the conterminous United States... lengths, shooting hours, bag and possession limits, and outside dates within which States may select...

The Language of Fifty Commonly Used Forms.

ERIC Educational Resources Information Center

Abbass, Mazin

The study analyzes, for readability and difficulty, the language of 50 commonly used application forms. The forms were compared with respect to length, readability, t-unit density, and word-length variables. Forms were also compared against two word-frequency lists. Results show that many of the words appearing often on forms do not appear on the…

76 FR 56797 - Cut-to-Length Carbon-Quality Steel Plate From India, Indonesia, Italy, Japan, and Korea; Revised...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-14

... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 701-TA-388-391 and 731-TA-817-821 ;Second Review] Cut-to-Length Carbon-Quality Steel Plate From India, Indonesia, Italy, Japan, and Korea; Revised schedule for the subject reviews. AGENCY: United States International Trade Commission. ACTION: Notice...

Direct extraction of electron parameters from magnetoconductance analysis in mesoscopic ring array structures

NASA Astrophysics Data System (ADS)

Sawada, A.; Faniel, S.; Mineshige, S.; Kawabata, S.; Saito, K.; Kobayashi, K.; Sekine, Y.; Sugiyama, H.; Koga, T.

2018-05-01

We report an approach for examining electron properties using information about the shape and size of a nanostructure as a measurement reference. This approach quantifies the spin precession angles per unit length directly by considering the time-reversal interferences on chaotic return trajectories within mesoscopic ring arrays (MRAs). Experimentally, we fabricated MRAs using nanolithography in InGaAs quantum wells which had a gate-controllable spin-orbit interaction (SOI). As a result, we observed an Onsager symmetry related to relativistic magnetic fields, which provided us with indispensable information for the semiclassical billiard ball simulation. Our simulations, developed based on the real-space formalism of the weak localization/antilocalization effect including the degree of freedom for electronic spin, reproduced the experimental magnetoconductivity (MC) curves with high fidelity. The values of five distinct electron parameters (Fermi wavelength, spin precession angles per unit length for two different SOIs, impurity scattering length, and phase coherence length) were thereby extracted from a single MC curve. The methodology developed here is applicable to wide ranges of nanomaterials and devices, providing a diagnostic tool for exotic properties of two-dimensional electron systems.

A proposal for unification of fatigue crack growth law

NASA Astrophysics Data System (ADS)

Kobelev, V.

2017-05-01

In the present paper, the new fractional-differential dependences of cycles to failure for a given initial crack length upon the stress amplitude in the linear fracture approach are proposed. The anticipated unified propagation function describes the infinitesimal crack length growths per increasing number of load cycles, supposing that the load ratio remains constant over the load history. Two unification fractional-differential functions with different number of fitting parameters are proposed. An alternative, threshold formulations for the fractional-differential propagation functions are suggested. The mean stress dependence is the immediate consequence from the considered laws. The corresponding formulas for crack length over the number of cycles are derived in closed form.

Damping factor estimation using spin wave attenuation in permalloy film

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

Manago, Takashi, E-mail: manago@fukuoka-u.ac.jp; Yamanoi, Kazuto; Kasai, Shinya

2015-05-07

Damping factor of a Permalloy (Py) thin film is estimated by using the magnetostatic spin wave propagation. The attenuation lengths are obtained by the dependence of the transmission intensity on the antenna distance, and decrease with increasing magnetic fields. The relationship between the attenuation length, damping factor, and external magnetic field is derived theoretically, and the damping factor was determined to be 0.0063 by fitting the magnetic field dependence of the attenuation length, using the derived equation. The obtained value is in good agreement with the general value of Py. Thus, this estimation method of the damping factor using spinmore » waves attenuation can be useful tool for ferromagnetic thin films.« less

Size-dependent elastic/inelastic behavior of enamel over millimeter and nanometer length scales.

PubMed

Ang, Siang Fung; Bortel, Emely L; Swain, Michael V; Klocke, Arndt; Schneider, Gerold A

2010-03-01

The microstructure of enamel like most biological tissues has a hierarchical structure which determines their mechanical behavior. However, current studies of the mechanical behavior of enamel lack a systematic investigation of these hierarchical length scales. In this study, we performed macroscopic uni-axial compression tests and the spherical indentation with different indenter radii to probe enamel's elastic/inelastic transition over four hierarchical length scales, namely: 'bulk enamel' (mm), 'multiple-rod' (10's microm), 'intra-rod' (100's nm with multiple crystallites) and finally 'single-crystallite' (10's nm with an area of approximately one hydroxyapatite crystallite). The enamel's elastic/inelastic transitions were observed at 0.4-17 GPa depending on the length scale and were compared with the values of synthetic hydroxyapatite crystallites. The elastic limit of a material is important as it provides insights into the deformability of the material before fracture. At the smallest investigated length scale (contact radius approximately 20 nm), elastic limit is followed by plastic deformation. At the largest investigated length scale (contact size approximately 2 mm), only elastic then micro-crack induced response was observed. A map of elastic/inelastic regions of enamel from millimeter to nanometer length scale is presented. Possible underlying mechanisms are also discussed. (c) 2009 Elsevier Ltd. All rights reserved.

Prevalence of obesity and the effect on length of mechanical ventilation and length of stay in intensive care patients: A single site observational study.

PubMed

Dennis, Diane M; Bharat, Chrianna; Paterson, Timothy

2017-05-01

To provide a snapshot of the prevalence of abnormal body mass index (BMI) in a sample of intensive care unit (ICU) patients; to identify if any medical specialty was associated with abnormal BMI and to explore associations between BMI and ICU-related outcomes. Obesity is an escalating public health issue across developed nations but there is little data pertaining to critically ill patients who require care that is expensive. Retrospective observational audit of 735 adult patients (median age 58 years) admitted to the Sir Charles Gairdner Hospital 23 bed tertiary ICU between November 2012 and June 2014. Primary outcome measure was patient BMI: underweight (<18.5kg/m 2 ), normal weight (18.5-24.99kg/m 2 ), overweight (25-29.99kg/m 2 ), obese (30-39.99kg/m 2 ) or extreme obese (40kg/m 2 or above). Other measures included gender, acute physiology and chronic health evaluation II score, admission specialty, length of mechanical ventilation (MV), length of stay (LOS) and mortality. Compared to the general population there was a higher proportion of obese patients within the cohort with the majority of patients overweight (33.9%) or obese (36.5%) and median BMI of 27.9 (IQR 7.9). There were no significant differences between specialties for BMI (p=0.103) and abnormal BMI was not found to impact negatively on mortality (ICU, p=0.373; hospital, p=0.330). Normal BMI patients had shorter length of MV than other BMI categories and the impact of BMI on ICU LOS was dependent on length of MV. Overweight patients ventilated for five days or more had a shorter LOS, and extremely obese non-ventilated patients had a longer LOS, compared to normal weight patients. Although the obesity-disease relationship is increasingly complex and data presented reflects categorical BMI for patients admitted to a single ICU site it may be important to consider the cost implications of caring for this cohort especially with regard to MV and LOS. Copyright © 2016 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.

SI units.

PubMed

Lehmann, H P

1979-01-01

The development of the International System of Units (Systeme International d'Unites--SE Units), based on seven fundamental quantities--length, mass, time, electric current, thermodynamic temperature, luminous intensity, and amount of substance is described. Units (coherent and noncoherent) for other measurable quantities that are derived from the seven basic quantities are reviewed. The rationale for the use of SE units in medicine, primarily as applied to clinical laboratory data, is discussed, and arguments are presented for the rigid adoption of SI units in medicine and for exceptions. Tables are given for the basic and derived SI units used in medicine and for conversion factors from the quantities and units in current use to those in SI units.

Exploring Linear Measure.

ERIC Educational Resources Information Center

Cox, Philip L.

This material is an instructional unit on measuring and estimating. A variety of activities are used with manipulative devices, worksheets, and discussion questions included. Major topics are estimating lengths, accuracy of measurement, metric system, scale drawings, and conversion between different units. A teacher's guide is also available.…

Gravitational lensing effects of vacuum strings - Exact solutions

NASA Technical Reports Server (NTRS)

Gott, J. R., III

1985-01-01

Exact interior and exterior solutions to Einstein's field equations are derived for vacuum strings. The exterior solution for a uniform density vacuum string corresponds to a conical space while the interior solution is that of a spherical cap. For Mu equals 0-1/4 the external metric is ds-squared = -dt-squared + dr-squared + (1-4 Mu)-squared r-squared dphi-squared + dz-squared, where Mu is the mass per unit length in the string in Planck masses per Planck length. A maximum mass per unit length for a string is 6.73 x 10 to the 27th g/cm. It is shown that strings cause temperature fluctuations in the cosmic microwave background and produce equal brightness double QSO images separated by up to several minutes of arc. Formulae for lensing probabilities, image splittings, and time delays are derived for strings in a realistic cosmological setting. String searches using ST, the VLA, and the COBE satellite are discussed.

The Effects of Delirium Prevention Guidelines on Elderly Stroke Patients.

PubMed

Song, Jihye; Lee, Minkyung; Jung, Dukyoo

2017-07-01

This study aimed to evaluate the effectiveness of the delirium prevention interventions recommended by the Delirium Prevention Guidelines for Elderly Stroke Patients (DPGESP). The DPGESP comprises nine dimensions with 28 interventions, including risk factor assessment, orientation disorder prevention, sleeping pattern maintenance, sensory interventions, constipation, dehydration, hypoxia and infection prevention, pain management, and appropriate nutrition maintenance. This quasi-experimental study used a nonequivalent control group and a pretest-posttest design. The experimental and control groups each included 54 patients, and the participants were elderly patients who were admitted to the stroke unit. The study outcomes were the delirium incidence and severity, stroke impact, and length of hospitalization. Posttest values for delirium incidence, severity, stroke impact, and length of hospitalization were significantly improved in the experimental group. Implementation of the DPGESP had beneficial effects on the delirium incidence and severity, stroke impact, and length of hospitalization among elderly patients admitted to a stroke unit.

Predicting long-term citation impact of articles in social and personality psychology.

PubMed

Haslam, Nick; Koval, Peter

2010-06-01

The citation impact of a comprehensive sample of articles published in social and personality psychology journals in 1998 was evaluated. Potential predictors of the 10-yr. citation impact of 1580 articles from 37 journals were investigated, including number of authors, number of references, journal impact factor, author nationality, and article length, using linear regression. The impact factor of the journal in which articles appeared was the primary predictor of the citations that they accrued, accounting for 30% of the total variance. Articles with greater length, more references, and more authors were cited relatively often, although the citation advantage of longer articles was not proportionate to their length. A citation advantage was also enjoyed by authors from the United States of America, Canada, and the United Kingdom. 37% of the variance in the total number of citations was accounted for by the study variables.

Load-dependent regulation of neuromuscular system

NASA Technical Reports Server (NTRS)

Ohira, Yoshinobu; Kawano, Fuminori; Stevens, James L.; Wang, Xiao D.; Ishihara, Akihiko

2004-01-01

Roles of gravitational loading, sarcomere length, and/or tension development on the electromyogram (EMG) of soleus and afferent neurogram recorded at the L5 segmental level of spinal cord were investigated during parabolic flight of a jet airplane or hindlimb suspension in conscious rats. Both EMG and neurogram levels were increased when the gravity levels were elevated from 1-G to 2-G during the parabolic flight. They were decreased when the hindlimbs were unloaded by exposure to actual microgravity or by suspension. These phenomena were related to passive shortening of muscle fibers and/or sarcomeres. Unloading-related decrease in sarcomere length was greater at the central rather than the proximal and distal regions of fibers. These activities and tension development were not detected when the mean sarcomere length was less than 2.03 micrometers. It is suggested that load-dependent regulation of neuromuscular system is related to the tension development which is influenced by sarcomere length.

Clove oil as an anaesthetic for adult sockeye salmon: Field trials

USGS Publications Warehouse

Woody, C.A.; Nelson, Jack L.; Ramstad, K.

2002-01-01

Wild migrating sockeye salmon Oncorhynchus nerka exposed to 20, 50 and 80 mg 1-1 of clove oil could be handled within 3 min, recovered within 10 min, and survived 15 min exposure trials. Fish tested at 110 mg 1-1 did not recover from 15 min exposure trials. Response curves developed for induction and recovery time considered the following predictors: clove oil concentration, sex, fish length and depth. A significant positive dependence was observed between induction time and fish length for 20, 50 and 80 mg 1-1 test concentrations; no dependence was observed between induction time and length at 110 and 140 mg 1-1. Recovery time differed as a function of clove oil concentration, but not fish size. A concentration of 50 mg 1-1 is recommended for anaesthetizing sockeye salmon ranging in length from 400 to 550 mm at water temperatures averaging 9-10??C.

On the physics of electron ejection from laser-irradiated overdense plasmas

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

Thévenet, M.; Vincenti, H.; Faure, J.

2016-06-15

Using 1D and 2D PIC simulations, we describe and model the backward ejection of electron bunches when a laser pulse reflects off an overdense plasma with a short density gradient on its front side. The dependence on the laser intensity and gradient scale length is studied. It is found that during each laser period, the incident laser pulse generates a large charge-separation field, or plasma capacitor, which accelerates an attosecond bunch of electrons toward vacuum. This process is maximized for short gradient scale lengths and collapses when the gradient scale length is comparable to the laser wavelength. We develop amore » model that reproduces the electron dynamics and the dependence on laser intensity and gradient scale length. This process is shown to be strongly linked with high harmonic generation via the Relativistic Oscillating Mirror mechanism.« less

On the relationship between acoustic energy density flux near the jet axis and far field acoustic intensity

NASA Technical Reports Server (NTRS)

Maestrello, L.

1973-01-01

By measurement and analysis, the relationship between the distribution of the outflow of acoustic energy over the jet boundary and the far-field intensity is considered. The physical quantity used is the gradient of the pressure evaluated on a geometrical plane at the smallest possible radial distance from the jet axis, but outside the vortical region, in the area where the homogeneous wave equation is reasonably well satisfied. The numerical and experimental procedures involved have been checked out by using a known source. Results indicate that the acoustic power output per unit length of the jet, in the region from which the sound emanates, peaks at approximately 9 diameters downstream. The acoustic emission for a jet Strouhal number of about 0.3 exceeds the emission for all other Strouhal numbers nearly everywhere along the measurement plane. However, the far-field peak intensity distribution obtained from the contribution of each station was found to depend on the spatial extent of the region where sound emanates from the jet, which, in turn, depends more on the far-field angle than on the Strouhal number.

Optimal control of M/M/1 two-phase queueing system with state-dependent arrival rate, server breakdowns, delayed repair, and N-policy

NASA Astrophysics Data System (ADS)

Rao, Hanumantha; Kumar, Vasanta; Srinivasa Rao, T.; Srinivasa Kumar, B.

2018-04-01

In this paper, we examine a two-stage queueing system where the arrivals are Poisson with rate depends on the condition of the server to be specific: vacation, pre-service, operational or breakdown state. The service station is liable to breakdowns and deferral in repair because of non-accessibility of the repair facility. The service is in two basic stages, the first being bulk service to every one of the customers holding up on the line and the second stage is individual to each of them. The server works under N-policy. The server needs preliminary time (startup time) to begin batch service after a vacation period. Startup times, uninterrupted service times, the length of each vacation period, delay times and service times follows an exponential distribution. The closed form of expressions for the mean system size at different conditions of the server is determined. Numerical investigations are directed to concentrate the impact of the system parameters on the ideal limit N and the minimum base expected unit cost.

Mid-Infrared Long-Baseline Interferometry of the Symbiotic Mira Star RX Pup with the VLTI/MIDI Instrument

NASA Astrophysics Data System (ADS)

Driebe, T.; Hofmann, K.-H.; Ohnaka, K.; Schertl, D.; Weigelt, G.

2007-11-01

We present mid-infrared long-baseline interferometric observations of the symbiotic Mira star RX Pup obtained with the VLTI/MIDI instrument within the framework of the Science Demonstration Time (SDT) program in February 2004. Four visibility measurements have been carried out using the unit telescopes UT2 and UT3, with projected baseline lengths ranging from 34.7 to 46.5 m. All visibility measurements show a distinct wavelength dependence: a rather steep decrease between 8 and 10 μm, and a shallower monotonic increase longward of 10 μm. For the corresponding uniform disk diameter, this visibility shape translates into a diameter increase by a factor of 2 from 25 to 50 mas between 8 and 10 μm and an almost wavelength-independent diameter between 10 and 13 μm. As we show by means of radiative transfer modeling with the code dusty, this wavelength dependence measured with VLTI/MIDI can be interpreted as the mid-infrared signature of a circumstellar dust shell which is dominated by silicate dust.

Emerging and Submerging Shorelines: Impacts of Physical Change on Bioband Length

NASA Astrophysics Data System (ADS)

Kruger, L. E.; Johnson, A. C.; Gregovich, D.; Buma, B.; Noel, J.

2017-12-01

We approximated shifts in coastal benthic species for shoreline length units undergoing both sea level rise and relative sea level lowering (often post-glacial, termed isostatic rebound) where subsistence-based, southeast Alaska Natives reside. From six community centers, we examined 30 km radii shoreline reaches by merging relevant portions of the NOAA ShoreZone database with near shore bathymetry and measures of mean global sea level rise with local global positioning system information (GIS) of tectonic shift and isostatic rebound. For our analysis, we estimated change for 9,868 assessed shoreline length units having uniform substrate and biologic type over a 100-yr time span (2008-2108) using geometric analysis of shoreline attributes. For each shoreline length unit we assessed relationships among substrate, slope, exposure, and presence of five benthic species including eel grass (Zostera marina), blue mussel (Mytilus edulis), butter clams (Saxidomus gigantean), bull kelp (Nereocytis leutkeana), and foliose red algae including ribbon kelp (Palmaria sp.). Our research indicates that both emergence, up to 1.8 m, and submergence, up 0.2 m, of the land will result in disportionately larger shoreline length segment alterations for habitats in protected low-slope gradient bays and estuaries (dominated by eelgrass and butter clam habitats) with less change for rocky steep-gradient exposed penninsulas (red algae and canopy kelp). This trend, holding true regardless of isostatic rebound, tectonic shift or sea level rise rate, highlights the importance of initial geomorphology-based assessments serving to improve bio-physical, chemical, and socially-related coastal research. Where shorelines are emerging 30% decreases in estuary lengths are predicted, but where shorelines are submerging up to 3% increases in estuaries are expected. Our research results are consistent with anthropology studies assessing past coastal change. Coastal change, influencing subsistance foods, salmon rearing areas, ocean acidification rate, and ocean carbon sequestration rate, have relevance to community resilience.

Impact from Magnitude-Rupture Length Uncertainty on Seismic Hazard and Risk

NASA Astrophysics Data System (ADS)

Apel, E. V.; Nyst, M.; Kane, D. L.

2015-12-01

In probabilistic seismic hazard and risk assessments seismic sources are typically divided into two groups: fault sources (to model known faults) and background sources (to model unknown faults). In areas like the Central and Eastern United States and Hawaii the hazard and risk is driven primarily by background sources. Background sources can be modeled as areas, points or pseudo-faults. When background sources are modeled as pseudo-faults, magnitude-length or magnitude-area scaling relationships are required to construct these pseudo-faults. However the uncertainty associated with these relationships is often ignored or discarded in hazard and risk models, particularly when faults sources are the dominant contributor. Conversely, in areas modeled only with background sources these uncertainties are much more significant. In this study we test the impact of using various relationships and the resulting epistemic uncertainties on the seismic hazard and risk in the Central and Eastern United States and Hawaii. It is common to use only one magnitude length relationship when calculating hazard. However, Stirling et al. (2013) showed that for a given suite of magnitude-rupture length relationships the variability can be quite large. The 2014 US National Seismic Hazard Maps (Petersen et al., 2014) used one magnitude-rupture length relationship (Somerville, et al., 2001) in the Central and Eastern United States, and did not consider variability in the seismogenic rupture plane width. Here we use a suite of metrics to compare the USGS approach with these variable uncertainty models to assess 1) the impact on hazard and risk and 2) the epistemic uncertainty associated with choice of relationship. In areas where the seismic hazard is dominated by larger crustal faults (e.g. New Madrid) the choice of magnitude-rupture length relationship has little impact on the hazard or risk. However away from these regions, the choice of relationship is more significant and may approach the size of the uncertainty associated with the ground motion prediction equation suite.

Prenatal Exposure to Traffic Pollution: Associations with Reduced Fetal Growth and Rapid Infant Weight Gain

PubMed Central

Fleisch, Abby F.; Rifas-Shiman, Sheryl L.; Koutrakis, Petros; Schwartz, Joel D.; Kloog, Itai; Melly, Steven; Coull, Brent A.; Zanobetti, Antonella; Gillman, Matthew W.; Gold, Diane R.; Oken, Emily

2014-01-01

Background Prenatal air pollution exposure inhibits fetal growth, but implications for postnatal growth are unknown. Methods We assessed weights and lengths of US infants in the Project Viva cohort at birth and 6 months. We estimated third-trimester residential air pollution exposures using spatiotemporal models. We estimated neighborhood traffic density and roadway proximity at birth address using geographic information systems. We performed linear and logistic regression adjusted for sociodemographic variables, fetal growth, and gestational age at birth. Results Mean birth weight-for-gestational age z-score (fetal growth) was 0.17 (SD = 0.97; n=2,114), 0-6 month weight-for-length gain was 0.23 z-units (SD = 1.11; n=689), and 17% had weight-for-length ≥95th percentile at 6 months of age. Infants exposed to the highest (vs. lowest) quartile of neighborhood traffic density had lower fetal growth (−0.13 units [95% confidence interval (CI) = −0.25 to −0.01]), more rapid 0-6 month weight-for-length gain (0.25 units [95% CI = 0.01 to 0.49]), and higher odds of weight-for-length ≥95th percentile at 6 months (1.84 [95% CI = 1.11 to 3.05]). Neighborhood traffic density was additionally associated with an infant being in both the lowest quartile of fetal growth and highest quartile of 0-6 month weight-for-length gain (Q4 vs. Q1, OR = 3.01 [95% CI = 1.08 to 8.44]). Roadway proximity and third-trimester black carbon exposure were similarly associated with growth outcomes. For third-trimester PM2.5, effect estimates were in the same direction, but smaller and imprecise. Conclusions Infants exposed to higher traffic-related pollution in early life may exhibit more rapid postnatal weight gain in addition to reduced fetal growth. PMID:25437317

Prenatal exposure to traffic pollution: associations with reduced fetal growth and rapid infant weight gain.

PubMed

Fleisch, Abby F; Rifas-Shiman, Sheryl L; Koutrakis, Petros; Schwartz, Joel D; Kloog, Itai; Melly, Steven; Coull, Brent A; Zanobetti, Antonella; Gillman, Matthew W; Gold, Diane R; Oken, Emily

2015-01-01

Prenatal air pollution exposure inhibits fetal growth, but implications for postnatal growth are unknown. We assessed weights and lengths of US infants in the Project Viva cohort at birth and 6 months. We estimated 3rd-trimester residential air pollution exposures using spatiotemporal models. We estimated neighborhood traffic density and roadway proximity at birth address using geographic information systems. We performed linear and logistic regression adjusted for sociodemographic variables, fetal growth, and gestational age at birth. Mean birth weight-for-gestational age z-score (fetal growth) was 0.17 (standard deviation [SD] = 0.97; n = 2,114), 0- to 6-month weight-for-length gain was 0.23 z-units (SD = 1.11; n = 689), and 17% had weight-for-length ≥95th percentile at 6 months of age. Infants exposed to the highest (vs. lowest) quartile of neighborhood traffic density had lower fetal growth (-0.13 units [95% confidence interval (CI) = -0.25 to -0.01]), more rapid 0- to 6-month weight-for-length gain (0.25 units [95% CI = 0.01 to 0.49]), and higher odds of weight-for-length ≥95th percentile at 6 months (1.84 [95% CI = 1.11 to 3.05]). Neighborhood traffic density was additionally associated with an infant being in both the lowest quartile of fetal growth and the highest quartile of 0- to 6-month weight-for-length gain (Q4 vs. Q1, odds ratio = 3.01 [95% CI = 1.08 to 8.44]). Roadway proximity and 3rd-trimester black carbon exposure were similarly associated with growth outcomes. For 3rd-trimester particulate matter (PM2.5), effect estimates were in the same direction, but smaller and imprecise. Infants exposed to higher traffic-related pollution in early life may exhibit more rapid postnatal weight gain in addition to reduced fetal growth.

The dependence of the properties of optical fibres on length

NASA Astrophysics Data System (ADS)

Poppett, C. L.; Allington-Smith, J. R.

2010-05-01

We investigate the dependence on length of optical fibres used in astronomy, especially the focal ratio degradation (FRD) which places constraints on the performance of fibre-fed spectrographs used for multiplexed spectroscopy. To this end, we present a modified version of the FRD model proposed by Carrasco & Parry to quantify the number of scattering defects within an optical fibre using a single parameter. The model predicts many trends which are seen experimentally, for example, a decrease in FRD as core diameter increases, and also as wavelength increases. However, the model also predicts a strong dependence on FRD with length that is not seen experimentally. By adapting the single fibre model to include a second fibre, we can quantify the amount of FRD due to stress caused by the method of termination. By fitting the model to experimental data, we find that polishing the fibre causes more stress to be induced in the end of the fibre compared to a simple cleave technique. We estimate that the number of scattering defects caused by polishing is approximately double that produced by cleaving. By placing limits on the end effect, the model can be used to estimate the residual-length dependence in very long fibres, such as those required for Extremely Large Telescopes, without having to carry out costly experiments. We also use our data to compare different methods of fibre termination.

On the electrostatic deceleration of argon atoms in high Rydberg states by time-dependent inhomogeneous electric fields

NASA Astrophysics Data System (ADS)

Vliegen, E.; Merkt, F.

2005-06-01

Argon atoms in a pulsed supersonic expansion are prepared in selected Stark components of Rydberg states with effective principal quantum number in the range n* = 15-25. When traversing regions of inhomogeneous electric fields, these atoms get accelerated or decelerated depending on whether the Stark states are low- or high-field seeking states. Using a compact electrode design, which enables the application of highly inhomogeneous and time-dependent electric fields, the Rydberg atoms experience kinetic energy changes of up to 1.2 × 10-21 J (i.e. 60 cm-1 in spectroscopic units) in a single acceleration/deceleration stage of 3 mm length. The resulting differences in the velocities of the low- and high-field seeking states are large enough that the corresponding distributions of times of flight to the Rydberg particle detector are fully separated. As a result, efficient spectral searches of the Rydberg states best suited for acceleration/deceleration experiments are possible. Numerical simulations of the particle trajectories are used to analyse the time-of-flight distributions and to optimize the time dependence of the inhomogeneous electric fields. The decay of the Rydberg states by fluorescence, collisions and transitions induced by black-body radiation takes place on a timescale long enough not to interfere significantly with the deceleration during the first ~5 µs.

Levee Presence and Wetland Areas within the 100-Year Floodplain of the Wabash Basin

NASA Astrophysics Data System (ADS)

Morrison, R. R.; Dong, Q.; Nardi, F.; Grantham, T.; Annis, A.

2016-12-01

Wetlands have declined over the past century due to land use changes and water management activities in the United States. Levees have been extensively built to provide protection against flooding events, and can fundamentally alter the water distribution and hydrologic dynamics within floodplains. Although levees can reduce wetlands in many places, it is unclear how much wetland areas are impacted at a basin-scale. This study explores the relationship between wetlands, levee presence, and other important hydrologic metrics within a 100-year floodplain. We estimated total wetland area, levee length, floodplain area and other variables, in discrete 12-digit hydrologic units (HUC-12) of the Wabash Basin (n=854) and examined the relationship between these variables using non-parametric statistical tests. We found greater areas of wetland habitat in HUC12 units that contain levees compared to those without levees when we aggregated the results across the entire basin. Factors such as stream order, mean annual flow, and HUC12 area are not correlated with the wetland area in HUC-12 units that contain levees. In addition, median wetland area in HUC12 units with levees is surprisingly consistent regardless of maximum stream order. Visual observations of wetland distributions indicate that wetland presence may be dependent on its location relative to levees. These results indicate that refined geospatial analyses may be necessary to explore the complex influence of levees on wetland habitat, and that additional basins should be explored to develop more generalized trends. This information is preliminary and subject to revision.

Magnetic exchange coupling through superconductors : a trilayer study.

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

Sa de Melo, C. A. R.; Materials Science Division

1997-09-08

The possibility of magnetic exchange coupling between two ferromagnets (F) separated by a superconductor (S) spacer is analyzed using the functional integral method. For this coupling to occur three prima facie conditions need to be satisfied. First, an indirect exchange coupling between the ferromagnets must exist when the superconductor is in its normal state. Second, superconductivity must not be destroyed due to the proximity to ferromagnetic boundaries. Third, roughness of the F/S interfaces must be small. Under these conditions, when the superconductor is cooled to below its critical temperature, the magnetic coupling changes. The appearance of the superconducting gap introducesmore » a new length scale (the coherence length of the superconductor) and modifies the temperature dependence of the indirect exchange coupling existent in the normal state. The magnetic coupling is oscillatory both above and below the critical temperature of the superconductor, as well as strongly temperature-dependent. However, at low temperatures the indirect exchange coupling decay length is controlled by the coherence length of the superconductor, while at temperatures close to and above the critical temperature of the superconductor the magnetic coupling decay length is controlled by the thermal length.« less

Percentiles of the run-length distribution of the Exponentially Weighted Moving Average (EWMA) median chart

NASA Astrophysics Data System (ADS)

Tan, K. L.; Chong, Z. L.; Khoo, M. B. C.; Teoh, W. L.; Teh, S. Y.

2017-09-01

Quality control is crucial in a wide variety of fields, as it can help to satisfy customers’ needs and requirements by enhancing and improving the products and services to a superior quality level. The EWMA median chart was proposed as a useful alternative to the EWMA \\bar{X} chart because the median-type chart is robust against contamination, outliers or small deviation from the normality assumption compared to the traditional \\bar{X}-type chart. To provide a complete understanding of the run-length distribution, the percentiles of the run-length distribution should be investigated rather than depending solely on the average run length (ARL) performance measure. This is because interpretation depending on the ARL alone can be misleading, as the process mean shifts change according to the skewness and shape of the run-length distribution, varying from almost symmetric when the magnitude of the mean shift is large, to highly right-skewed when the process is in-control (IC) or slightly out-of-control (OOC). Before computing the percentiles of the run-length distribution, optimal parameters of the EWMA median chart will be obtained by minimizing the OOC ARL, while retaining the IC ARL at a desired value.

Comparative study of the Aristotle Comprehensive Complexity and the Risk Adjustment in Congenital Heart Surgery scores.

PubMed

Bojan, Mirela; Gerelli, Sébastien; Gioanni, Simone; Pouard, Philippe; Vouhé, Pascal

2011-09-01

The Aristotle Comprehensive Complexity (ACC) and the Risk Adjustment in Congenital Heart Surgery (RACHS-1) scores have been proposed for complexity adjustment in the analysis of outcome after congenital heart surgery. Previous studies found RACHS-1 to be a better predictor of outcome than the Aristotle Basic Complexity score. We compared the ability to predict operative mortality and morbidity between ACC, the latest update of the Aristotle method and RACHS-1. Morbidity was assessed by length of intensive care unit stay. We retrospectively enrolled patients undergoing congenital heart surgery. We modeled each score as a continuous variable, mortality as a binary variable, and length of stay as a censored variable. We compared performance between mortality and morbidity models using likelihood ratio tests for nested models and paired concordance statistics. Among all 1,384 patients enrolled, 30-day mortality rate was 3.5% and median length of intensive care unit stay was 3 days. Both scores strongly related to mortality, but ACC made better prediction than RACHS-1; c-indexes 0.87 (0.84, 0.91) vs 0.75 (0.65, 0.82). Both scores related to overall length of stay only during the first postoperative week, but ACC made better predictions than RACHS-1; U statistic=0.22, p<0.001. No significant difference was noted after adjusting RACHS-1 models on age, prematurity, and major extracardiac abnormalities. The ACC was a better predictor of operative mortality and length of intensive care unit stay than RACHS-1. In order to achieve similar performance, regression models including RACHS-1 need to be further adjusted on age, prematurity, and major extracardiac abnormalities. Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

[Risk factors for nosocomial pneumonia in patients with abdominal surgery].

PubMed

Evaristo-Méndez, Gerardo; Rocha-Calderón, César Haydn

2016-01-01

The risk of post-operative pneumonia is a latent complication. A study was conducted to determine its risk factors in abdominal surgery. A cross-sectional study was performed that included analysing the variables of age and gender, chronic obstructive pulmonary disease and smoking, serum albumin, type of surgery and anaesthesia, emergency or elective surgery, incision site, duration of surgery, length of hospital stay, length of stay in the intensive care unit, and time on mechanical ventilation. The adjusted odds ratio for risk factors was obtained using multivariate logistic regression. The study included 91 (9.6%) patients with pneumonia and 851 (90.4%) without pneumonia. Age 60 years or over (OR=2.34), smoking (OR=9.48), chronic obstructive pulmonary disease (OR=3.52), emergency surgery (OR=2.48), general anaesthesia (OR=3.18), surgical time 120 minutes or over (OR=5.79), time in intensive care unit 7 days or over (OR=1.23), time on mechanical ventilation greater than or equal to 4 days (OR=5.93) and length of post-operative hospital stay of 15 days or over (OR=1.20), were observed as independent predictors for the development of postoperative pneumonia. Identifying risk factors for post-operative pneumonia may prevent their occurrence. The length in the intensive care unit of greater than or equal to 7 days (OR=1.23; 95% CI 1.07 - 1.42) and a length postoperative hospital stay of 15 days or more (OR=1.20; 95% CI 1.07 - 1.34) were the predictive factors most strongly associated with lung infection in this study. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

Geometric contribution leading to anomalous estimation of two-dimensional electron gas density in GaN based heterostructures

NASA Astrophysics Data System (ADS)

Upadhyay, Bhanu B.; Jha, Jaya; Takhar, Kuldeep; Ganguly, Swaroop; Saha, Dipankar

2018-05-01

We have observed that the estimation of two-dimensional electron gas density is dependent on the device geometry. The geometric contribution leads to the anomalous estimation of the GaN based heterostructure properties. The observed discrepancy is found to originate from the anomalous area dependent capacitance of GaN based Schottky diodes, which is an integral part of the high electron mobility transistors. The areal capacitance density is found to increase for smaller radii Schottky diodes, contrary to a constant as expected intuitively. The capacitance is found to follow a second order polynomial on the radius of all the bias voltages and frequencies considered here. In addition to the quadratic dependency corresponding to the areal component, the linear dependency indicates a peripheral component. It is further observed that the peripheral to areal contribution is inversely proportional to the radius confirming the periphery as the location of the additional capacitance. The peripheral component is found to be frequency dependent and tends to saturate to a lower value for measurements at a high frequency. In addition, the peripheral component is found to vanish when the surface is passivated by a combination of N2 and O2 plasma treatments. The cumulative surface state density per unit length of the perimeter of the Schottky diodes as obtained by the integrated response over the distance between the ohmic and Schottky contacts is found to be 2.75 × 1010 cm-1.

An Analysis of Unit Costs at a Consolidated Supply Depot

DTIC Science & Technology

1990-12-01

Not-For-Profit Setting,"The Accounting Review,July 1990. Horngren , C. T., Cost Accountinq:A Managerial Emphasis,3rd ed, Prentice-Hall Inc.,1972...sector has used concepts of unit costs for 4 decades. Any managerial or cost accounting text discusses in some length unit costs . For Defense contractors...the Cost Accounting Standards Board (CASB) provides guidance for contract costs . Unit costs include direct, indirect, and general and administrative

Automated detection of physiologic deterioration in hospitalized patients.

PubMed

Evans, R Scott; Kuttler, Kathryn G; Simpson, Kathy J; Howe, Stephen; Crossno, Peter F; Johnson, Kyle V; Schreiner, Misty N; Lloyd, James F; Tettelbach, William H; Keddington, Roger K; Tanner, Alden; Wilde, Chelbi; Clemmer, Terry P

2015-03-01

Develop and evaluate an automated case detection and response triggering system to monitor patients every 5 min and identify early signs of physiologic deterioration. A 2-year prospective, observational study at a large level 1 trauma center. All patients admitted to a 33-bed medical and oncology floor (A) and a 33-bed non-intensive care unit (ICU) surgical trauma floor (B) were monitored. During the intervention year, pager alerts of early physiologic deterioration were automatically sent to charge nurses along with access to a graphical point-of-care web page to facilitate patient evaluation. Nurses reported the positive predictive value of alerts was 91-100% depending on erroneous data presence. Unit A patients were significantly older and had significantly more comorbidities than unit B patients. During the intervention year, unit A patients had a significant increase in length of stay, more transfers to ICU (p = 0.23), and significantly more medical emergency team (MET) calls (p = 0.0008), and significantly fewer died (p = 0.044) compared to the pre-intervention year. No significant differences were found on unit B. We monitored patients every 5 min and provided automated pages of early physiologic deterioration. This before-after study found a significant increase in MET calls and a significant decrease in mortality only in the unit with older patients with multiple comorbidities, and thus further study is warranted to detect potential confounding. Moreover, nurses reported the graphical alerts provided information needed to quickly evaluate patients, and they felt more confident about their assessment and more comfortable requesting help. © The Author 2014. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Contextual Factors, Indoor Tanning, and Tanning Dependence in Young Women

PubMed Central

Heckman, Carolyn J.; Darlow, Susan D.; Kloss, Jacqueline D.; Munshi, Teja; Manne, Sharon L.

2015-01-01

Objectives The study's purpose was to investigate the association of contextual factors such as cost, tanning accessibility, regulations, or marketing and indoor tanning or tanning dependence. Methods One hundred thirty-nine college-aged female indoor tanners completed a questionnaire between 2009 and 2011. Results Higher scores on tanning dependence and assessment in the spring/summer (versus the fall/winter) were associated with more frequent indoor tanning in the last 30 days (ps < .05). More frequent indoor tanning, greater session length, and more trouble paying for tanning were associated with higher scores on tanning dependence (ps < .05). Conclusions Public health research and practice could benefit from attention to such contextual factors as tanning cost and regulations regarding session length. PMID:25741682

Stimulus-dependent modulation of spike burst length in cat striate cortical cells.

PubMed

DeBusk, B C; DeBruyn, E J; Snider, R K; Kabara, J F; Bonds, A B

1997-07-01

Burst activity, defined by groups of two or more spikes with intervals of < or = 8 ms, was analyzed in responses to drifting sinewave gratings elicited from striate cortical neurons in anesthetized cats. Bursting varied broadly across a population of 507 simple and complex cells. Half of this population had > or = 42% of their spikes contained in bursts. The fraction of spikes in bursts did not vary as a function of average firing rate and was stationary over time. Peaks in the interspike interval histograms were found at both 3-5 ms and 10-30 ms. In many cells the locations of these peaks were independent of firing rate, indicating a quantized control of firing behavior at two different time scales. The activity at the shorter time scale most likely results from intrinsic properties of the cell membrane, and that at the longer scale from recurrent network excitation. Burst frequency (bursts per s) and burst length (spikes per burst) both depended on firing rate. Burst frequency was essentially linear with firing rate, whereas burst length was a nonlinear function of firing rate and was also governed by stimulus orientation. At a given firing rate, burst length was greater for optimal orientations than for nonoptimal orientations. No organized orientation dependence was seen in bursts from lateral geniculate nucleus cells. Activation of cortical contrast gain control at low response amplitudes resulted in no burst length modulation, but burst shortening at optimal orientations was found in responses characterized by supersaturation. At a given firing rate, cortical burst length was shortened by microinjection of gamma-aminobutyric acid (GABA), and bursts became longer in the presence of N-methyl-bicuculline, a GABA(A) receptor blocker. These results are consistent with a model in which responses are reduced at nonoptimal orientations, at least in part, by burst shortening that is mediated by GABA. A similar mechanism contributes to response supersaturation at high contrasts via recruitment of inhibitory responses that are tuned to adjacent orientations. Burst length modulation can serve as a form of coding by supporting dynamic, stimulus-dependent reorganization of the effectiveness of individual network connections.

Multiple bottlenecks in hierarchical control of action sequences: what does "response selection" select in skilled typewriting?

PubMed

Yamaguchi, Motonori; Logan, Gordon D; Li, Vanessa

2013-08-01

Does response selection select words or letters in skilled typewriting? Typing performance involves hierarchically organized control processes: an outer loop that controls word level processing, and an inner loop that controls letter (or keystroke) level processing. The present study addressed whether response selection occurs in the outer loop or the inner loop by using the psychological refractory period (PRP) paradigm in which Task1 required typing single words and Task2 required vocal responses to tones. The number of letters (string length) in the words was manipulated to discriminate selection of words from selection of keystrokes. In Experiment 1, the PRP effect depended on string length of words in Task1, suggesting that response selection occurs in the inner loop. To assess contributions of the outer loop, the influence of string length was examined in a lexical-decision task that also involves word encoding and lexical access (Experiment 2), or to-be-typed words were preexposed so outer-loop processing could finish before typing started (Experiment 3). Response time for Task2 (RT2) did not depend on string length with lexical decision, and RT2 still depended on string length with typing preexposed strings. These results support the inner-loop locus of the PRP effect. In Experiment 4, typing was performed as Task2, and the effect of string length on typing RT interacted with stimulus onset asynchrony superadditively, implying that another bottleneck also exists in the outer loop. We conclude that there are at least two bottleneck processes in skilled typewriting. 2013 APA, all rights reserved

Inventory of a Neurological Intensive Care Unit: Who Is Treated and How Long?

PubMed Central

Backhaus, Roland; Aigner, Franz; Steffling, Dagmar; Jakob, Wolfgang; Steinbrecher, Andreas; Kaiser, Bernhard; Hau, Peter; Boy, Sandra; Fuchs, Kornelius; Bogdahn, Ulrich; Ritzka, Markus

2015-01-01

Purpose. To characterize indications, treatment, and length of stay in a stand-alone neurological intensive care unit with focus on comparison between ventilated and nonventilated patient. Methods. We performed a single-center retrospective cohort study of all treated patients in our neurological intensive care unit between October 2006 and December 2008. Results. Overall, 512 patients were treated in the surveyed period, of which 493 could be included in the analysis. Of these, 40.8% had invasive mechanical ventilation and 59.2% had not. Indications in both groups were predominantly cerebrovascular diseases. Length of stay was 16.5 days in mean for ventilated and 3.6 days for nonventilated patient. Conclusion. Most patients, ventilated or not, suffer from vascular diseases with further impairment of other organ systems or systemic complications. Data reflects close relationship and overlap of treatment on nICU with a standardized stroke unit treatment and suggests, regarding increasing therapeutic options, the high impact of acute high-level treatment to reduce consequential complications. PMID:26199757

Determination of the electrical resistivity of vertically aligned carbon nanotubes by scanning probe microscopy

NASA Astrophysics Data System (ADS)

Ageev, O. A.; Il'in, O. I.; Rubashkina, M. V.; Smirnov, V. A.; Fedotov, A. A.; Tsukanova, O. G.

2015-07-01

Techniques are developed to determine the resistance per unit length and the electrical resistivity of vertically aligned carbon nanotubes (VA CNTs) using atomic force microscopy (AFM) and scanning tunneling microscopy (STM). These techniques are used to study the resistance of VA CNTs. The resistance of an individual VA CNT calculated with the AFM-based technique is shown to be higher than the resistance of VA CNTs determined by the STM-based technique by a factor of 200, which is related to the influence of the resistance of the contact of an AFM probe to VA CNTs. The resistance per unit length and the electrical resistivity of an individual VA CNT 118 ± 39 nm in diameter and 2.23 ± 0.37 μm in height that are determined by the STM-based technique are 19.28 ± 3.08 kΩ/μm and 8.32 ± 3.18 × 10-4 Ω m, respectively. The STM-based technique developed to determine the resistance per unit length and the electrical resistivity of VA CNTs can be used to diagnose the electrical parameters of VA CNTs and to create VA CNT-based nanoelectronic elements.

Artificially controlled backscattering in single mode fibers based on femtosecond laser fabricated reflectors

NASA Astrophysics Data System (ADS)

Wang, Xiaoliang; Chen, Daru; Li, Haitao; Wu, Qiong

2018-04-01

A novel method to artificially control the backscattering of the single-mode fiber (SMF) is proposed and investigated for the first time. This method can help to fabricate a high backscattering fiber (HBSF), such as by fabricating reflectors in every one meter interval of an SMF based on the exposure of the femtosecond laser beam. The artificially controlled backscattering (ACBS) can be much higher than the natural Rayleigh backscattering (RB) of the SMF. The RB power and ACBS power in the unit length fiber are derived according to the theory of the RBS. The total relative power and the relative back power reflected in the unit length of the HBSF have been simulated and presented. The simulated results show that the HBSF has the characteristics of both low optical attenuation and high backscattering. The relative back power reflected in the unit length of the HBSF is 25dB larger than the RB power of the SMF when the refractive index modulation quantity of the reflectors is 0.009. Some preliminary experiments also indicate that the method fabricating reflectors to increase the backscattering power of the SMF is practical and promising.

Study on Edge Thickening Flow Forming Using the Finite Elements Analysis

NASA Astrophysics Data System (ADS)

Kim, Young Jin; Park, Jin Sung; Cho, Chongdu

2011-08-01

This study is to examine the forming features of flow stress property and the incremental forming method with increasing the thickness of material. Recently, the optimized forming method is widely studied through the finite element analysis to optimize forming process conditions in many different forming fields. The optimal forming method should be adopted to meet geometric requirements as the reduction in volume per unit length of material such as forging, rolling, spinning etc. However conventional studies have not dealt with issue regarding volume per unit length. For the study we use the finite element method and model a gear part of an automotive engine flywheel as the study model, which is a weld assembly of a plate and a gear with respective different thickness. In simulation of the present study, a optimized forming condition for gear machining, considering the thickness of the outer edge of flywheel is studied using the finite elements analysis for the increasing thickness of the forming method. It is concluded from the study that forming method to increase the thickness per unit length for gear machining is reasonable using the finite elements analysis and forming test.

Force-Induced Rupture of a DNA Duplex: From Fundamentals to Force Sensors.

PubMed

Mosayebi, Majid; Louis, Ard A; Doye, Jonathan P K; Ouldridge, Thomas E

2015-12-22

The rupture of double-stranded DNA under stress is a key process in biophysics and nanotechnology. In this article, we consider the shear-induced rupture of short DNA duplexes, a system that has been given new importance by recently designed force sensors and nanotechnological devices. We argue that rupture must be understood as an activated process, where the duplex state is metastable and the strands will separate in a finite time that depends on the duplex length and the force applied. Thus, the critical shearing force required to rupture a duplex depends strongly on the time scale of observation. We use simple models of DNA to show that this approach naturally captures the observed dependence of the force required to rupture a duplex within a given time on duplex length. In particular, this critical force is zero for the shortest duplexes, before rising sharply and then plateauing in the long length limit. The prevailing approach, based on identifying when the presence of each additional base pair within the duplex is thermodynamically unfavorable rather than allowing for metastability, does not predict a time-scale-dependent critical force and does not naturally incorporate a critical force of zero for the shortest duplexes. We demonstrate that our findings have important consequences for the behavior of a new force-sensing nanodevice, which operates in a mixed mode that interpolates between shearing and unzipping. At a fixed time scale and duplex length, the critical force exhibits a sigmoidal dependence on the fraction of the duplex that is subject to shearing.

Electrophoresis of semiflexible heteropolymers and the ``hydrodynamic Kuhn length''

NASA Astrophysics Data System (ADS)

Chubynsky, Mykyta V.; Slater, Gary W.

Semiflexible polymers, such as DNA, are rodlike for short lengths and coil-like for long lengths. For purely geometric properties, such as the end-to-end distance, the crossover between these two behaviors occurs when the polymer length is on the order of the Kuhn length. On the other hand, for the hydrodynamic friction coefficient it is easy to see by comparing the expressions for a rod and a coil that the crossover should occur at the polymer length, termed by us the hydrodynamic Kuhn length, which is larger than the ordinary Kuhn length by a logarithmic factor that can be quite significant. We show that for the problem of electrophoresis of a heteropolymer consisting of several blocks of (in general) different stiffnesses, both of these length scales can be important depending on the details of the problem.

Amperometric biosensor based on glassy carbon electrode modified with long-length carbon nanotube and enzyme

NASA Astrophysics Data System (ADS)

Furutaka, Hajime; Nemoto, Kentaro; Inoue, Yuki; Hidaka, Hiroki; Muguruma, Hitoshi; Inoue, Hitoshi; Ohsawa, Tatsuya

2016-05-01

An amperometric biosensor based on a glassy carbon electrode modified with long-length multiwalled carbon nanotubes (MWCNTs) and enzyme nicotinamide-adenine-dinucleotide-dependent glucose dehydrogenase (GDH) is presented. We demonstrate the effect of the MWCNT length on the amperometric response of the enzyme biosensor. The long length of MWCNT is 200 µm (average), whereas the normal length of MWCNT is 1 µm (average). The response of the long MWCNT-GDH electrode is 2 times more sensitive than that of the normal-length MWCNT-GDH electrode in the concentration range from 0.25-35 mM. The result of electrochemical impedance spectroscopy measurements suggest that the long-length MWCNT-GDH electrode formed a better electron transfer network than the normal-length one.

Ecological Differences in Weight, Length, and Weight for Length of Mexican American Children in the WIC Program

PubMed Central

Ritsema, Melanie

2016-01-01

PURPOSE Examine factors common in the environments of children who obtain services from a WIC program to determine if differences in ecological/environmental factors can be found in the children who differ in weight, length, and weight for length. DESIGN AND METHODS Cross-sectional study of 300 children, 100 each who were stunted, normal weight for length, or overweight. Instruments used were NCATS, ARSMA II, 24-hr diet recall, and Baecke Activity Questionnaire. RESULTS Significant differences were present in children’s diet, parents’ BMI, parents’ generation in United States, parents’ activity levels, and maternal–child relationship. PRACTICE IMPLICATIONS Encourage parents to adopt family approaches to encourage normal body size in children. PMID:18638046

Assessing Children's Understanding of Length Measurement: A Focus on Three Key Concepts

ERIC Educational Resources Information Center

Bush, Heidi

2009-01-01

In this article, the author presents three different tasks that can be used to assess students' understanding of the concept of length. Three important measurement concepts for students to understand are transitive reasoning, use of identical units, and iteration. In any teaching and learning process it is important to acknowledge students'…

Determinants of Length of Stay in Stroke Patients: A Geriatric Rehabilitation Unit Experience

ERIC Educational Resources Information Center

Atalay, Ayce; Turhan, Nur

2009-01-01

The objective was to identify the predictors of length of stay--the impact of age, comorbidity, and stroke subtype--on the outcome of geriatric stroke patients. One hundred and seventy stroke patients (129 first-ever ischemic, 25 hemorrhagic, and 16 ischemic second strokes) were included in the study. The Oxfordshire Community Stroke Project…

Length of Stay of Pediatric Mental Health Emergency Department Visits in the United States

ERIC Educational Resources Information Center

Case, Sarah D.; Case, Brady G.; Olfson, Mark; Linakis, James G.; Laska, Eugene M.

2011-01-01

Objective: To compare pediatric mental health emergency department visits to other pediatric emergency department visits, focusing on length of stay. Method: We analyzed data from the National Hospital Ambulatory Medical Care Survey, a nationally representative sample of US emergency department visits from 2001 to 2008, for patients aged less than…

Current sheet extension and reconnection scaling in collisionless, hyperresistive, Hall MHD

NASA Astrophysics Data System (ADS)

Sullivan, B. P.; Bhattacharjee, A.; Huang, Y. M.

2009-11-01

We present Sweet-Parker type scaling arguments in the context of collisionless, hyper-resistive, Hall magnetohyrdodynamics (MHD). The predicted steady state scalings are consistent with those found by Chac'on et al. [PRL 99, 235001 (2007)], and Uzdensky, [PoP 16, 040702 (2009)], though our methods differ slightly. As with those studies, no prediction of electron dissipation region length is made. Numerical experiments confirm that both cusp like & extended geometries are realizable. Importantly, the length of the electron dissipation region (taken as a parameter by several recent studies) is found to depend on the level of hyper-resistivity. Although hyper-resistivity can produce modestly extended dissipation regions, the dissipation regions observed here are much shorter than those seen in many kinetic studies. The thickness of the dissipation region scales in a similar way as the length,so that the reconnection rate is not strongly sensitive to the level of hyperresistivity. The length of the electron dissipation region depends on electron inertia as well.The limitations of scaling theories that do not predict the length of the electron dissipation region are emphasized.

StratBAM: A Discrete-Event Simulation Model to Support Strategic Hospital Bed Capacity Decisions.

PubMed

Devapriya, Priyantha; Strömblad, Christopher T B; Bailey, Matthew D; Frazier, Seth; Bulger, John; Kemberling, Sharon T; Wood, Kenneth E

2015-10-01

The ability to accurately measure and assess current and potential health care system capacities is an issue of local and national significance. Recent joint statements by the Institute of Medicine and the Agency for Healthcare Research and Quality have emphasized the need to apply industrial and systems engineering principles to improving health care quality and patient safety outcomes. To address this need, a decision support tool was developed for planning and budgeting of current and future bed capacity, and evaluating potential process improvement efforts. The Strategic Bed Analysis Model (StratBAM) is a discrete-event simulation model created after a thorough analysis of patient flow and data from Geisinger Health System's (GHS) electronic health records. Key inputs include: timing, quantity and category of patient arrivals and discharges; unit-level length of care; patient paths; and projected patient volume and length of stay. Key outputs include: admission wait time by arrival source and receiving unit, and occupancy rates. Electronic health records were used to estimate parameters for probability distributions and to build empirical distributions for unit-level length of care and for patient paths. Validation of the simulation model against GHS operational data confirmed its ability to model real-world data consistently and accurately. StratBAM was successfully used to evaluate the system impact of forecasted patient volumes and length of stay in terms of patient wait times, occupancy rates, and cost. The model is generalizable and can be appropriately scaled for larger and smaller health care settings.

Optical lenses design and experimental investigations of a dynamic focusing unit for a CO2 laser scanning system

NASA Astrophysics Data System (ADS)

Chen, Wei; Xu, Yue; Zhang, Huaxin; Liu, Peng; Jiao, Guohua

2016-09-01

Laser scanners are critical components in material processing systems, such as welding, cutting, and drilling. To achieve high-accuracy processing, the laser spot size should be small and uniform in the entire objective flat field. However, traditional static focusing method using F-theta objective lens is limited by the narrow flat field. To overcome these limitations, a dynamic focusing unit consisting of two lenses is presented in this paper. The dual-lens system has a movable plano-concave lens and a fixed convex lens. As the location of the movable optical elements is changed, the focal length is shifted to keep a small focus spot in a broad flat processing filed. The optical parameters of the two elements are theoretical analyzed. The spot size is calculated to obtain the relationship between the moving length of first lens and the shift focus length of the system. Also, the Zemax model of the optical system is built up to verify the theoretical design and optimize the optical parameter. The proposed lenses are manufactured and a test system is built up to investigate their performances. The experimental results show the spot size is smaller than 450um in all the 500*500mm 2 filed with CO2 laser. Compared with the other dynamic focusing units, this design has fewer lenses and no focusing spot in the optical path. In addition, the focal length minimal changes with the shit of incident laser beam.

The Effect on Melanoma Risk of Genes Previously Associated With Telomere Length

PubMed Central

Bishop, D. Timothy; Taylor, John C.; Hayward, Nicholas K.; Brossard, Myriam; Cust, Anne E.; Dunning, Alison M.; Lee, Jeffrey E.; Moses, Eric K.; Akslen, Lars A.; Andresen, Per A.; Avril, Marie-Françoise; Azizi, Esther; Scarrà, Giovanna Bianchi; Brown, Kevin M.; Dębniak, Tadeusz; Elder, David E.; Friedman, Eitan; Ghiorzo, Paola; Gillanders, Elizabeth M.; Goldstein, Alisa M.; Gruis, Nelleke A.; Hansson, Johan; Harland, Mark; Helsing, Per; Hočevar, Marko; Höiom, Veronica; Ingvar, Christian; Kanetsky, Peter A.; Landi, Maria Teresa; Lang, Julie; Lathrop, G. Mark; Lubiński, Jan; Mackie, Rona M.; Martin, Nicholas G.; Molven, Anders; Montgomery, Grant W.; Novaković, Srdjan; Olsson, Håkan; Puig, Susana; Puig-Butille, Joan Anton; Radford-Smith, Graham L.; Randerson-Moor, Juliette; van der Stoep, Nienke; van Doorn, Remco; Whiteman, David C.; MacGregor, Stuart; Pooley, Karen A.; Ward, Sarah V.; Mann, Graham J.; Amos, Christopher I.; Pharoah, Paul D. P.; Demenais, Florence; Law, Matthew H.; Newton Bishop, Julia A.; Barrett, Jennifer H.

2014-01-01

Telomere length has been associated with risk of many cancers, but results are inconsistent. Seven single nucleotide polymorphisms (SNPs) previously associated with mean leukocyte telomere length were either genotyped or well-imputed in 11108 case patients and 13933 control patients from Europe, Israel, the United States and Australia, four of the seven SNPs reached a P value under .05 (two-sided). A genetic score that predicts telomere length, derived from these seven SNPs, is strongly associated (P = 8.92x10-9, two-sided) with melanoma risk. This demonstrates that the previously observed association between longer telomere length and increased melanoma risk is not attributable to confounding via shared environmental effects (such as ultraviolet exposure) or reverse causality. We provide the first proof that multiple germline genetic determinants of telomere length influence cancer risk. PMID:25231748

Dependence of the Linker Histone and Chromatin Condensation on the Nucleosome Environment.

PubMed

Perišić, Ognjen; Schlick, Tamar

2017-08-24

The linker histone (LH), an auxiliary protein that can bind to chromatin and interact with the linker DNA to form stem motifs, is a key element of chromatin compaction. By affecting the chromatin condensation level, it also plays an active role in gene expression. However, the presence and variable concentration of LH in chromatin fibers with different DNA linker lengths indicate that its folding and condensation are highly adaptable and dependent on the immediate nucleosome environment. Recent experimental studies revealed that the behavior of LH in mononucleosomes markedly differs from that in small nucleosome arrays, but the associated mechanism is unknown. Here we report a structural analysis of the behavior of LH in mononucleosomes and oligonucleosomes (2-6 nucleosomes) using mesoscale chromatin simulations. We show that the adapted stem configuration heavily depends on the strength of electrostatic interactions between LH and its parental DNA linkers, and that those interactions tend to be asymmetric in small oligonucleosome systems. Namely, LH in oligonucleosomes dominantly interacts with one DNA linker only, as opposed to mononucleosomes where LH has similar interactions with both linkers and forms a highly stable nucleosome stem. Although we show that the LH condensation depends sensitively on the electrostatic interactions with entering and exiting DNA linkers, other interactions, especially by nonparental cores and nonparental linkers, modulate the structural condensation by softening LH and thus making oligonucleosomes more flexible, in comparison to to mono- and dinucleosomes. We also find that the overall LH/chromatin interactions sensitively depend on the linker length because the linker length determines the maximal nucleosome stem length. For mononucleosomes with DNA linkers shorter than LH, LH condenses fully, while for DNA linkers comparable or longer than LH, the LH extension in mononucleosomes strongly follows the length of DNA linkers, unhampered by neighboring linker histones. Thus, LH is more condensed for mononucleosomes with short linkers, compared to oligonucleosomes, and its orientation is variable and highly environment-dependent. More generally, the work underscores the agility of LH whose folding dynamics critically controls genomic packaging and gene expression.

Molecular Modeling of Thermosetting Polymers: Effects of Degree of Curing and Chain Length on Thermo-Mechanical Properties

DTIC Science & Technology

2012-08-01

paper, we will first briefly discuss our recent results, using coarse-grained bead - spring model , on the dependence of failure stress and failure...length of the resin strands. In the coarse-grained model used here the polymer network is treated as a bead - spring system. To create highly cross...simulations of Thermosets We have used a coarse-grained bead - spring model to study the dependence of the mechanical properties of thermosets on chain

A non-modular type B feruloyl esterase from Neurospora crassa exhibits concentration-dependent substrate inhibition.

PubMed Central

Crepin, Valerie F; Faulds, Craig B; Connerton, Ian F

2003-01-01

Feruloyl esterases, a subclass of the carboxylic acid esterases (EC 3.1.1.1), are able to hydrolyse the ester bond between the hydroxycinnamic acids and sugars present in the plant cell wall. The enzymes have been classified as type A or type B, based on their substrate specificity for aromatic moieties. We show that Neurospora crassa has the ability to produce multiple ferulic acid esterase activities depending upon the length of fermentation with either sugar beet pulp or wheat bran substrates. A gene identified on the basis of its expression on sugar beet pulp has been cloned and overexpressed in Pichia pastoris. The gene encodes a single-domain ferulic acid esterase, which represents the first report of a non-modular type B enzyme (fae-1 gene; GenBank accession no. AJ293029). The purified recombinant protein has been shown to exhibit concentration-dependent substrate inhibition (K(m) 0.048 mM, K (i) 2.5 mM and V(max) 8.2 units/mg against methyl 3,4-dihydroxycinnamate). The kinetic behaviour of the non-modular enzyme is discussed in terms of the diversity in the roles of the feruloyl esterases in the mobilization of plant cell wall materials and their respective modes of action. PMID:12435269

Tracheid length prediction in Pinus palustris by means of near infrared spectroscopy: the influence of age

Treesearch

Brian K. Via; Todd F. Shupe; Michael Stine; Chi-Leung So; Leslie H. Groom

2005-01-01

The predidion of tracheid Length using near infrared (NIR) wavelengths can provide either useful or misleading calibrations depending on the context. This can happen since tracheid length is not directly related to the absorbance at any wavelength but is instead the result of a seondary correlation with some unknown chemical constituent. In this work, the effect of...

[Lung protective ventilation - pathophysiology and diagnostics].

PubMed

Uhlig, Stefan; Frerichs, Inéz

2008-06-01

Mechanical ventilation may lead to lung injury depending on the ventilatory settings (e.g. pressure amplitudes, endexpiratory pressures, frequency) and the length of mechanical ventilation. Particularly in the inhomogeneously injured lungs of ARDS patients, alveolar overextension results in volutrauma, cyclic opening and closure of alveolar units in atelectrauma. Particularly important appears to be the fact that these processes may also cause biotrauma, i.e. the ventilator-induced hyperactivation of inflammatory responses in the lung. These side effects are reduced, but not eliminated with the currently recommended ventilation strategy with a tidal volume of 6 ml/kg idealized body weight. It is our hope that in the future optimization of ventilator settings will be facilated by bedside monitoring of novel indices of respiratory mechanics such as the stress index or the Slice technique, and by innovative real-time imaging technologies such as electrical impedance tomography.

On Multiscale Modeling: Preserving Energy Dissipation Across the Scales with Consistent Handshaking Methods

NASA Technical Reports Server (NTRS)

Pineda, Evan J.; Bednarcyk, Brett A.; Arnold, Steven M.; Waas, Anthony M.

2013-01-01

A mesh objective crack band model was implemented within the generalized method of cells micromechanics theory. This model was linked to a macroscale finite element model to predict post-peak strain softening in composite materials. Although a mesh objective theory was implemented at the microscale, it does not preclude pathological mesh dependence at the macroscale. To ensure mesh objectivity at both scales, the energy density and the energy release rate must be preserved identically across the two scales. This requires a consistent characteristic length or localization limiter. The effects of scaling (or not scaling) the dimensions of the microscale repeating unit cell (RUC), according to the macroscale element size, in a multiscale analysis was investigated using two examples. Additionally, the ramifications of the macroscale element shape, compared to the RUC, was studied.

SU-E-J-252: A Motion Algorithm to Extract Physical and Motion Parameters of a Mobile Target in Cone-Beam Computed Tomographic Imaging Retrospective to Image Reconstruction

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

Ali, I; Ahmad, S; Alsbou, N

Purpose: A motion algorithm was developed to extract actual length, CT-numbers and motion amplitude of a mobile target imaged with cone-beam-CT (CBCT) retrospective to image-reconstruction. Methods: The motion model considered a mobile target moving with a sinusoidal motion and employed three measurable parameters: apparent length, CT number level and gradient of a mobile target obtained from CBCT images to extract information about the actual length and CT number value of the stationary target and motion amplitude. The algorithm was verified experimentally with a mobile phantom setup that has three targets with different sizes manufactured from homogenous tissue-equivalent gel material embeddedmore » into a thorax phantom. The phantom moved sinusoidal in one-direction using eight amplitudes (0–20mm) and a frequency of 15-cycles-per-minute. The model required imaging parameters such as slice thickness, imaging time. Results: This motion algorithm extracted three unknown parameters: length of the target, CT-number-level, motion amplitude for a mobile target retrospective to CBCT image reconstruction. The algorithm relates three unknown parameters to measurable apparent length, CT-number-level and gradient for well-defined mobile targets obtained from CBCT images. The motion model agreed with measured apparent lengths which were dependent on actual length of the target and motion amplitude. The cumulative CT-number for a mobile target was dependent on CT-number-level of the stationary target and motion amplitude. The gradient of the CT-distribution of mobile target is dependent on the stationary CT-number-level, actual target length along the direction of motion, and motion amplitude. Motion frequency and phase did not affect the elongation and CT-number distributions of mobile targets when imaging time included several motion cycles. Conclusion: The motion algorithm developed in this study has potential applications in diagnostic CT imaging and radiotherapy to extract actual length, size and CT-numbers distorted by motion in CBCT imaging. The model provides further information about motion of the target.« less

Copper Coordination in the Full-Length, Recombinant Prion Protein†

PubMed Central

Burns, Colin S.; Aronoff-Spencer, Eliah; Legname, Giuseppe; Prusiner, Stanley B.; Antholine, William E.; Gerfen, Gary J.; Peisach, Jack; Millhauser, Glenn L.

2010-01-01

The prion protein (PrP) binds divalent copper at physiologically relevant conditions and is believed to participate in copper regulation or act as a copper-dependent enzyme. Ongoing studies aim at determining the molecular features of the copper binding sites. The emerging consensus is that most copper binds in the octarepeat domain, which is composed of four or more copies of the fundamental sequence PHGGGWGQ. Previous work from our laboratory using PrP-derived peptides, in conjunction with EPR and X-ray crystallography, demonstrated that the HGGGW segment constitutes the fundamental binding unit in the octarepeat domain [Burns et al. (2002) Biochemistry 41, 3991–4001; Aronoff-Spencer et al. (2000) Biochemistry 39, 13760–13771]. Copper coordination arises from the His imidazole and sequential deprotonated glycine amides. In this present work, recombinant, full-length Syrian hamster PrP is investigated using EPR methodologies. Four copper ions are taken up in the octarepeat domain, which supports previous findings. However, quantification studies reveal a fifth binding site in the flexible region between the octarepeats and the PrP globular C-terminal domain. A series of PrP peptide constructs show that this site involves His96 in the PrP(92–96) segment GGGTH. Further examination by X-band EPR, S-band EPR, and electron spin–echo envelope spectroscopy, demonstrates coordination by the His96 imidazole and the glycine preceding the threonine. The copper affinity for this type of binding site is highly pH dependent, and EPR studies here show that recombinant PrP loses its affinity for copper below pH 6.0. These studies seem to provide a complete profile of the copper binding sites in PrP and support the hypothesis that PrP function is related to its ability to bind copper in a pH-dependent fashion. PMID:12779334

Evolution dependence of vanadium nitride nanoprecipitates on directionality of ion irradiation

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

Tan, L.; Kim, B. K.; Was, G. S.

The influence of the directionality of Fe 2+ ion irradiation on the evolution of vanadium nitride platelet–shaped nanoprecipitates at 500 °C was investigated in this paper in a ferritic alloy using transmission electron microscopy. When the ion-irradiation direction was approximately aligned with the initial particle length, particles grew longer and sectioned into shorter lengths at higher doses, resulting in increased particle densities. As ion-irradiation direction deviated from particle-length direction, some particles sectioned lengthwise and then dissolved, resulting in decreased particle densities. Surviving particles were transformed into parallelograms with a different orientation relationship with the matrix. Finally, nanoprecipitate evolution dependence onmore » beam-nanoprecipitate orientation is a process that may be different from reactor irradiation.« less

Evolution dependence of vanadium nitride nanoprecipitates on directionality of ion irradiation

DOE PAGES

Tan, L.; Kim, B. K.; Was, G. S.

2017-09-06

The influence of the directionality of Fe 2+ ion irradiation on the evolution of vanadium nitride platelet–shaped nanoprecipitates at 500 °C was investigated in this paper in a ferritic alloy using transmission electron microscopy. When the ion-irradiation direction was approximately aligned with the initial particle length, particles grew longer and sectioned into shorter lengths at higher doses, resulting in increased particle densities. As ion-irradiation direction deviated from particle-length direction, some particles sectioned lengthwise and then dissolved, resulting in decreased particle densities. Surviving particles were transformed into parallelograms with a different orientation relationship with the matrix. Finally, nanoprecipitate evolution dependence onmore » beam-nanoprecipitate orientation is a process that may be different from reactor irradiation.« less

33 CFR 107.210 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 107.210 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MARITIME SECURITY... Territorial Waters § 107.210 Applicability. (a) This subpart applies to: (1) Vessels of the United States less... territorial waters; (2) Vessels of the United States less than 100 meters (328 feet) in length (and all...

Responses of stream nitrate and DOC loadings to hydrological forcing and climate change in an upland forest of the northeastern United States

Treesearch

Stephen D. Sebestyen; Elizabeth W. Boyer; James B. Shanley

2009-01-01

In coming decades, higher annual temperatures, increased growing season length, and increased dormant season precipitation are expected across the northeastern United States in response to anthropogenic forcing of global climate. We synthesized long-term stream hydrochemical data from the Sleepers River Research Watershed in Vermont, United States, to explore the...

Is There a Career Penalty for Mothers' Time Out? A Comparison of Germany, Sweden and the United States

ERIC Educational Resources Information Center

Aisenbrey, Silke; Evertsson, Marie; Grunow, Daniela

2009-01-01

This article focuses on three countries with distinct policies toward motherhood and work: Germany, Sweden and the United States. We analyze the length of mothers' time out of paid work after childbirth and the short-term career consequences for mothers. In the United States, we identify a career punishment even for short time-out periods; long…

Quick Reads: The Unit Makes All the Difference

ERIC Educational Resources Information Center

Rollick, Mary Beth

2014-01-01

"What's the unit?" The answer to this question makes all the difference. A young child who is asked to count shoes needs to know if the unit to be counted is "pairs" of shoes or individual shoes. A middle school student who is asked for the length of a table will want to know if the number should be in inches, feet, or…

Micropillar Compression Technique Applied to Micron-Scale Mudstone Elasto-Plastic Deformation

NASA Astrophysics Data System (ADS)

Dewers, T. A.; Boyce, B.; Buchheit, T.; Heath, J. E.; Chidsey, T.; Michael, J.

2010-12-01

Mudstone mechanical testing is often limited by poor core recovery and sample size, preservation and preparation issues, which can lead to sampling bias, damage, and time-dependent effects. A micropillar compression technique, originally developed by Uchic et al. 2004, here is applied to elasto-plastic deformation of small volumes of mudstone, in the range of cubic microns. This study examines behavior of the Gothic shale, the basal unit of the Ismay zone of the Pennsylvanian Paradox Formation and potential shale gas play in southeastern Utah, USA. Precision manufacture of micropillars 5 microns in diameter and 10 microns in length are prepared using an ion-milling method. Characterization of samples is carried out using: dual focused ion - scanning electron beam imaging of nano-scaled pores and distribution of matrix clay and quartz, as well as pore-filling organics; laser scanning confocal (LSCM) 3D imaging of natural fractures; and gas permeability, among other techniques. Compression testing of micropillars under load control is performed using two different nanoindenter techniques. Deformation of 0.5 cm in diameter by 1 cm in length cores is carried out and visualized by a microscope loading stage and laser scanning confocal microscopy. Axisymmetric multistage compression testing and multi-stress path testing is carried out using 2.54 cm plugs. Discussion of results addresses size of representative elementary volumes applicable to continuum-scale mudstone deformation, anisotropy, and size-scale plasticity effects. Other issues include fabrication-induced damage, alignment, and influence of substrate. This work is funded by the US Department of Energy, Office of Basic Energy Sciences. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

Global cost analysis on adaptation to sea level rise based on RCP/SSP scenarios

NASA Astrophysics Data System (ADS)

Kumano, N.; Tamura, M.; Yotsukuri, M.; Kuwahara, Y.; Yokoki, H.

2017-12-01

Low-lying areas are the most vulnerable to sea level rise (SLR) due to climate change in the future. In order to adapt to SLR, it is necessary to decide whether to retreat from vulnerable areas or to install dykes to protect them from inundation. Therefore, cost- analysis of adaptation using coastal dykes is one of the most essential issues in the context of climate change and its countermeasures. However, few studies have globally evaluated the future costs of adaptation in coastal areas. This study tries to globally analyze the cost of adaptation in coastal areas. First, global distributions of projected inundation impacts induced by SLR including astronomical high tide were assessed. Economic damage was estimated on the basis of the econometric relationship between past hydrological disasters, affected population, and per capita GDP using CRED's EM-DAT database. Second, the cost of adaptation was also determined using the cost database and future scenarios. The authors have built a cost database for installed coastal dykes worldwide and applied it to estimating the future cost of adaptation. The unit costs of dyke construction will increase with socio-economic scenario (SSP) such as per capita GDP. Length of vulnerable coastline is calculated by identifying inundation areas using ETOPO1. Future cost was obtained by multiplying the length of vulnerable coastline and the unit cost of dyke construction. Third, the effectiveness of dyke construction was estimated by comparing cases with and without adaptation.As a result, it was found that incremental adaptation cost is lower than economic damage in the cases of SSP1 and SSP3 under RCP scenario, while the cost of adaptation depends on the durability of the coastal dykes.

Quantitative analysis of the role of fiber length on phagocytosis and inflammatory response by alveolar macrophages

PubMed Central

Padmore, Trudy; Stark, Carahline; Turkevich, Leonid A.; Champion, Julie A.

2017-01-01

Background In the lung, macrophages attempt to engulf inhaled high aspect ratio pathogenic materials, secreting inflammatory molecules in the process. The inability of macrophages to remove these materials leads to chronic inflammation and disease. How the biophysical and biochemical mechanisms of these effects are influenced by fiber length remains undetermined. This study evaluates the role of fiber length on phagocytosis and molecular inflammatory responses to non-cytotoxic fibers, enabling development of quantitative length-based models. Methods Murine alveolar macrophages were exposed to long and short populations of JM-100 glass fibers, produced by successive sedimentation and repeated crushing, respectively. Interactions between fibers and macrophages were observed using time-lapse video microscopy, and quantified by flow cytometry. Inflammatory biomolecules (TNF-α, IL-1 α, COX-2, PGE2) were measured. Results Uptake of short fibers occurred more readily than for long, but long fibers were more potent stimulators of inflammatory molecules. Stimulation resulted in dose-dependent secretion of inflammatory biomolecules but no cytotoxicity or strong ROS production. Linear cytokine dose-response curves evaluated with length-dependent potency models, using measured fiber length distributions, resulted in identification of critical fiber lengths that cause frustrated phagocytosis and increased inflammatory biomolecule production. Conclusion Short fibers played a minor role in the inflammatory response compared to long fibers. The critical lengths at which frustrated phagocytosis occurs can be quantified by fitting dose-response curves to fiber distribution data. PMID:27784615

Financial impact of nosocomial infections in the intensive care units of a charitable hospital in Minas Gerais, Brazil

PubMed Central

Nangino, Glaucio de Oliveira; de Oliveira, Cláudio Dornas; Correia, Paulo César; Machado, Noelle de Melo; Dias, Ana Thereza Barbosa

2012-01-01

Objective Infections in intensive care units are often associated with a high morbidity and mortality in addition to high costs. An analysis of these aspects can assist in optimizing the allocation of relevant financial resources. Methods This retrospective study analyzed the hospital administration and quality in intensive care medical databases [Sistema de Gestão Hospitalar (SGH)] and RM Janus®. A cost analysis was performed by evaluating the medical products and materials used in direct medical care. The costs are reported in the Brazilian national currency (Real). The cost and length of stay analyses were performed for all the costs studied. The median was used to determine the costs involved. Costs were also adjusted by the patients' length of stay in the intensive care unit. Results In total, 974 individuals were analyzed, of which 51% were male, and the mean age was 57±18.24 years. There were 87 patients (8.9%) identified who had nosocomial infections associated with the intensive care unit. The median cost per admission and the length of stay for all the patients sampled were R$1.257,53 and 3 days, respectively. Compared to the patients without an infection, the patients with an infection had longer hospital stays (15 [11-25] versus 3 [2-6] days, p<0.01), increased costs per patient in the intensive care unit (median R$9.763,78 [5445.64 - 18,007.90] versus R$1.093,94 [416.14 - 2755.90], p<0.01) and increased costs per day of hospitalization in the intensive care unit (R$618,00 [407.81 - 838.69] versus R$359,00 [174.59 - 719.12], p<0.01). Conclusion Nosocomial infections associated with the intensive care unit were determinants of increased costs and longer hospital stays. However, the study design did not allow us to evaluate specific aspects of cause and effect. PMID:23917933

Trends of Heller myotomy hospitalizations for achalasia in the United States, 1993-2005: effect of surgery volume on perioperative outcomes.

PubMed

Wang, Y Richard; Dempsey, Daniel T; Friedenberg, Frank K; Richter, Joel E

2008-10-01

Achalasia is a rare chronic disorder of esophageal motor function. Single-center reports suggest that there has been greater use of laparoscopic Heller myotomy for achalasia in the United States since its introduction in 1992. We aimed to study the trends of Heller myotomy and the relationship between surgery volume and perioperative outcomes. The Healthcare Cost and Utilization Project Nationwide Inpatient Sample (NIS) is a 20% stratified sample of all hospitalizations in the United States. It was used to study the macro-trends of Heller myotomy hospitalizations during 1993-2005. We also used the NIS 2003-2005 micro-data to study the perioperative outcomes of Heller myotomy hospitalizations, using other achalasia and laparoscopic cholecystectomy hospitalizations as control groups. The generalized linear model with repeated observations from the same unit was used to adjust for multiple hospitalizations from the same hospital. The national estimate of Heller myotomy hospitalizations increased from 728 to 2,255 during 1993-2005, while its mean length of stay decreased from 9.9 to 4.3 days. Of the 1,117 Heller myotomy hospitalizations in the NIS 2003-2005, 10 (0.9%) had the diagnosis of esophageal perforation at discharge. Length of stay was negatively correlated with a hospital's number of Heller myotomy per year (correlation coefficient -0.171, P < 0.001). In multivariate log-linear regressions with a control group, a hospital's number of Heller myotomy per year was negatively associated with length of stay (coefficient -0.215 to -0.119, both P < 0.001) and total charges (coefficient -0.252 to -0.073, both P < 0.10). These findings were robust in alternative statistical models, specifications, and subgroup analyses. On a national level, the introduction of laparoscopic Heller myotomy for achalasia was associated with greater use of surgery and shorter length of stay. A larger volume of Heller myotomy in a hospital was associated with better perioperative outcomes in terms of shorter length of stay and lower total charges.