Crystallization and preliminary X-ray analysis of gamma-glutamyltranspeptidase from Escherichia coli K-12.

PubMed

Kumagai, H; Nohara, S; Suzuki, H; Hashimoto, W; Yamamoto, K; Sakai, H; Sakabe, K; Fukuyama, K; Sakabe, N

1993-12-20

gamma-Glutamyltranspeptidase (EC 2.3.2.2) from Escherichia coli K-12 has been purified and crystallized by means of vapor diffusion in hanging drops. Two kinds of crystals on cell dimensions were found for X-ray diffraction analysis, one from ammonium sulfate and the other from polyethylene glycol 6000 as precipitants. The crystals of the orthorhombic form grown in the presence of 15% polyethylene glycol and 20 mM sodium acetate buffer were chosen for further analysis. The crystals belonged to space group P2(1)2(1)2(1), with cell dimensions of a = 128.1, b = 129.9 and c = 79.2 A, and two molecules constitute an asymmetric unit. These crystals diffracted to 2.0 A resolution and were suitable for X-ray crystallographic studies.

Validating Future Force Performance Measures (Army Class): In-Unit Performance Longitudinal Validation

DTIC Science & Technology

2012-09-01

adjusted for shrinkage using Burket’s (1964) formula ρc = (NR2 – k)/[R(N – k)], while estimates in the “Uncorrected” columns were not adjusted. Shaded cells ...identify predictors with higher values for a given statistic with the darker shaded cells containing the highest values. No information is provided...Dimensions • Emotional Stamina • Bravery and Courage • Vigilance In the early stages of CDPRS development, we included relevant AW PRS

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.

49 CFR Appendix C to Part 564 - Information Applicable to Standardized Sealed Beam Headlamp Units

Code of Federal Regulations, 2013 CFR

2013-10-01

... Standardized Sealed Beam Unit. A. Dimensions marked “I”, indicating interchangeability, for which conformance is mandatory. B. All other dimensions which are for design purposes. II. Dimensional Information... Sealed Beam Unit A. Dimensions marked “I”, indicating interchangeability, for which conformance is...

Neural networks with local receptive fields and superlinear VC dimension.

PubMed

Schmitt, Michael

2002-04-01

Local receptive field neurons comprise such well-known and widely used unit types as radial basis function (RBF) neurons and neurons with center-surround receptive field. We study the Vapnik-Chervonenkis (VC) dimension of feedforward neural networks with one hidden layer of these units. For several variants of local receptive field neurons, we show that the VC dimension of these networks is superlinear. In particular, we establish the bound Omega(W log k) for any reasonably sized network with W parameters and k hidden nodes. This bound is shown to hold for discrete center-surround receptive field neurons, which are physiologically relevant models of cells in the mammalian visual system, for neurons computing a difference of gaussians, which are popular in computational vision, and for standard RBF neurons, a major alternative to sigmoidal neurons in artificial neural networks. The result for RBF neural networks is of particular interest since it answers a question that has been open for several years. The results also give rise to lower bounds for networks with fixed input dimension. Regarding constants, all bounds are larger than those known thus far for similar architectures with sigmoidal neurons. The superlinear lower bounds contrast with linear upper bounds for single local receptive field neurons also derived here.

Metamaterial composition comprising frequency-selective-surface resonant element disposed on/in a dielectric flake, methods, and applications

DOEpatents

Shelton, David; Boreman, Glenn; D'Archangel, Jeffrey

2015-11-10

Infrared metamaterial arrays containing Au elements immersed in a medium of benzocyclobutene (BCB) were fabricated and selectively etched to produce small square flakes with edge dimensions of approximately 20 .mu.m. Two unit-cell designs were fabricated: one employed crossed-dipole elements while the other utilized square-loop elements.

Analytical relationships for prediction of the mechanical properties of additively manufactured porous biomaterials

PubMed Central

Hedayati, Reza

2016-01-01

Abstract Recent developments in additive manufacturing techniques have motivated an increasing number of researchers to study regular porous biomaterials that are based on repeating unit cells. The physical and mechanical properties of such porous biomaterials have therefore received increasing attention during recent years. One of the areas that have revived is analytical study of the mechanical behavior of regular porous biomaterials with the aim of deriving analytical relationships that could predict the relative density and mechanical properties of porous biomaterials, given the design and dimensions of their repeating unit cells. In this article, we review the analytical relationships that have been presented in the literature for predicting the relative density, elastic modulus, Poisson's ratio, yield stress, and buckling limit of regular porous structures based on various types of unit cells. The reviewed analytical relationships are used to compare the mechanical properties of porous biomaterials based on different types of unit cells. The major areas where the analytical relationships have improved during the recent years are discussed and suggestions are made for future research directions. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 3164–3174, 2016. PMID:27502358

Developments in Acoustic Metamaterials for Acoustic Ground Cloaks

NASA Astrophysics Data System (ADS)

Kerrian, Peter Adam

The objective of acoustic cloaking is to eliminate both the back scattered and forward scattered acoustic fields by redirecting the incident wave around an object. Acoustic ground cloaks, which conceal an object on a rigid reflecting surface, utilize a linear coordinate transformation to map the flat surface to a void by compressing space into two cloaking regions consisting of a homogeneous anisotropic acoustic metafluid. Transformation acoustics allows for the realization of a coordinate transformation through a reinterpretation of the scale factors as a new material in the original coordinate system. Previous work has demonstrated at least three types of unit cells exhibit homogeneous anisotropic mass density and homogeneous isotropic bulk modulus: alternating layers of homogeneous isotropic fluids, perforated plates and solid inclusions. The primary focus of this dissertation is to demonstrate underwater anisotropic mass density with a solid inclusion unit cell and realize an underwater perforated plate acoustic ground cloak. An in depth analysis into the methods used to characterize the effective material parameters of solid inclusion unit cells with water as the background fluid was performed for both single inclusion unit cells as well as multi-inclusion unit cells. The degree of density anisotropy obtainable for a rigid single inclusion unit cell is limited by the size of the inclusion. However, a greater degree of anisotropy can be achieved by introducing additional inclusions into the unit cell design. For example, including a foam material that is less dense than the background fluid, results in an anisotropic density tensor with one component greater than and one component less than the value of the background fluid. The results of a parametric study determined that for a multi-inclusion unit cell, the effective material parameters can be controlled by the dimensions of the rigid inclusion as well as the material parameters and dimensions of the foam inclusions. Non-destructive acoustic excitation techniques were used to extract the material parameters of different grades of foam to identify the ideal grade for use in a multi-inclusion unit cell. Single inclusion and multi-inclusion bulk metamaterial samples were constructed and tested to characterize the effective material properties to determine if they exhibited the desired homogeneous anisotropic behavior. The single steel inclusion metamaterial behaved as expected, demonstrating anisotropic mass density and isotropic bulk modulus. Almost no sound energy was transmitted through the multi-inclusion metamaterial, contrary to expectation, because of the presence of air bubbles, both on the surface of the foam as well as potentially in between the inclusions. Finally, an underwater acoustic ground cloak was constructed from perforated steel plates and experimentally tested to conceal an object on a pressure release surface. The perforated plate acoustic ground cloak successfully cloaked the scattered object over a broad frequency range of 7 [kHz] to 12 [kHz]. There was excellent agreement between the phase of the surface reflection and the cloak reflection with a small amplitude difference attributed to the difference between a water - air and a water - mylar - air boundary. Above 15 [kHz], the cloaking performance decreased as the effective material parameters of the perforated plate metamaterial deviated from the required material parameters.

Efficient Parameter Searches for Colloidal Materials Design with Digital Alchemy

NASA Astrophysics Data System (ADS)

Dodd, Paul, M.; Geng, Yina; van Anders, Greg; Glotzer, Sharon C.

Optimal colloidal materials design is challenging, even for high-throughput or genomic approaches, because the design space provided by modern colloid synthesis techniques can easily have dozens of dimensions. In this talk we present the methodology of an inverse approach we term ''digital alchemy'' to perform rapid searches of design-paramenter spaces with up to 188 dimensions that yield thermodynamically optimal colloid parameters for target crystal structures with up to 20 particles in a unit cell. The method relies only on fundamental principles of statistical mechanics and Metropolis Monte Carlo techniques, and yields particle attribute tolerances via analogues of familiar stress-strain relationships.

Low-loss and broadband anomalous Floquet topological insulator for airborne sound

NASA Astrophysics Data System (ADS)

Peng, Yu-Gui; Shen, Ya-Xi; Zhao, De-Gang; Zhu, Xue-Feng

2017-04-01

Anomalous Floquet topological insulators (AFIs) for airborne sound have recently been realized in experiments. However, the implemented version suffers from significant loss and narrowband due to thermal viscosity and dispersive coupling strength between unit-cells. Here, we propose a solution for realizing low-loss and broadband acoustic AFI. We show that the loss after passing through one unit-cell can be less than 2% for the topological edge states. It is also theoretically unveiled that in the frequency range of nearly unitary coupling (˜0.97 from 4.8 kHz to 7.0 kHz in our case), around 84% corresponds to topological bands. Our proposal may promote the application of large-dimension acoustic topological devices.

Cation substitution in synthetic meridianiite (MgSO4·11H2O) I: X-ray powder diffraction analysis of quenched polycrystalline aggregates

NASA Astrophysics Data System (ADS)

Fortes, A. Dominic; Browning, Frank; Wood, Ian G.

2012-05-01

Meridianiite, MgSO4·11H2O, is the most highly hydrated phase in the binary MgSO4-H2O system. Lower hydrates in the MgSO4-H2O system have end-member analogues containing alternative divalent metal cations (Ni2+, Zn2+, Mn2+, Cu2+, Fe2+, and Co2+) and exhibit extensive solid solution with MgSO4 and with one another, but no other undecahydrate is known. We have prepared aqueous MgSO4 solutions doped with these other cations in proportions up to and including the pure end-members. These liquids have been solidified into fine-grained polycrystalline blocks of metal sulfate hydrate + ice by rapid quenching in liquid nitrogen. The solid products have been characterised by X-ray powder diffraction, and the onset of partial melting has been quantified using a thermal probe. We have established that of the seven end-member metal sulfates studied, only MgSO4 forms an undecahydrate; ZnSO4 forms an orthorhombic heptahydrate (synthetic goslarite), MnSO4, FeSO4, and CoSO4 form monoclinic heptahydrates (syn. mallardite, melanterite, bieberite, respectively), and CuSO4 crystallises as the well-known triclinic pentahydrate (syn. chalcanthite). NiSO4 forms a new hydrate which has been indexed with a triclinic unit cell of dimensions a = 6.1275(1) Å, b = 6.8628(1) Å, c = 12.6318(2) Å, α = 92.904(2)°, β = 97.678(2)°, and γ = 96.618(2)°. The unit-cell volume of this crystal, V = 521.74(1) Å3, is consistent with it being an octahydrate, NiSO4·8H2O. Further analysis of doped specimens has shown that synthetic meridianiite is able to accommodate significant quantities of foreign cations in its structure; of the order 50 mol. % Co2+ or Mn2+, 20-30 mol. % Ni2+ or Zn2+, but less than 10 mol. % of Cu2+ or Fe2+. In three of the systems we examined, an `intermediate' phase occurred that differed in hydration state both from the Mg-bearing meridianiite end-member and the pure dopant end-member hydrate. In the case of CuSO4, we observed a melanterite-structured heptahydrate at Cu/(Cu + Mg) = 0.5, which we identify as synthetic alpersite [(Mg0.5Cu0.5)SO4·7H2O)]. In the NiSO4- and ZnSO4-doped systems we characterised an entirely new hydrate which could also be identified to a lesser degree in the CuSO4- and the FeSO4-doped systems. The Ni-doped substance has been indexed with a monoclinic unit-cell of dimensions a = 6.7488(2) Å, b = 11.9613(4) Å, c = 14.6321(5) Å, and β = 95.047(3)°, systematic absences being indicative of space-group P21/ c with Z = 4. The unit-cell volume, V = 1,176.59(5) Å3, is consistent with it being an enneahydrate [i.e. (Mg0.5Ni0.5)SO4·9H2O)]. Similarly, the new Zn-bearing enneahydrate has refined unit cell dimensions of a = 6.7555(3) Å, b = 11.9834(5) Å, c = 14.6666(8) Å, β = 95.020(4)°, V = 1,182.77(7) Å3, and the new Fe-bearing enneahydrate has refined unit cell dimensions of a = 6.7726(3) Å, b = 12.0077(3) Å, c = 14.6920(5) Å, β = 95.037(3)°, and V = 1,190.20(6) Å3. The observation that synthetic meridianiite can form in the presence of, and accommodate significant quantities of other ions increases the likelihood that this mineral will occur naturally on Mars—and elsewhere in the outer solar system—in metalliferous brines.

Global mammal beta diversity shows parallel assemblage structure in similar but isolated environments

PubMed Central

Graham, Catherine H.; Brooks, Thomas M.; Rondinini, Carlo; Hedges, S. Blair; Davidson, Ana D.; Costa, Gabriel C.

2016-01-01

The taxonomic, phylogenetic and trait dimensions of beta diversity each provide us unique insights into the importance of historical isolation and environmental conditions in shaping global diversity. These three dimensions should, in general, be positively correlated. However, if similar environmental conditions filter species with similar trait values, then assemblages located in similar environmental conditions, but separated by large dispersal barriers, may show high taxonomic, high phylogenetic, but low trait beta diversity. Conversely, we expect lower phylogenetic diversity, but higher trait biodiversity among assemblages that are connected but are in differing environmental conditions. We calculated all pairwise comparisons of approximately 110 × 110 km grid cells across the globe for more than 5000 mammal species (approx. 70 million comparisons). We considered realms as units representing geographical distance and historical isolation and biomes as units with similar environmental conditions. While beta diversity dimensions were generally correlated, we highlight geographical regions of decoupling among beta diversity dimensions. Our analysis shows that assemblages from tropical forests in different realms had low trait dissimilarity while phylogenetic beta diversity was significantly higher than expected, suggesting potential convergent evolution. Low trait beta diversity was surprisingly not found between isolated deserts, despite harsh environmental conditions. Overall, our results provide evidence for parallel assemblage structure of mammal assemblages driven by environmental conditions at a global scale. PMID:27559061

Imaging System For Measuring Macromolecule Crystal Growth Rates in Microgravity

NASA Technical Reports Server (NTRS)

Corder, Eric L.; Briscoe, Jeri

2004-01-01

In order to determine how macromolecule crystal quality improvement in microgravity is related to crystal growth characteristics, a team of scientists and engineers at NASA's Marshal Space Flight Center (MSFC) developed flight hardware capable of measuring the crystal growth rates of a population of crystals growing under the same conditions. As crystal growth rate is defined as the change or delta in a defined dimension or length (L) of crystal over time, the hardware was named Delta-L. Delta-L consists of three sub assemblies: a fluid unit including a temperature-controlled growth cell, an imaging unit, and a control unit (consisting of a Data Acquisition and Control Unit (DACU), and a thermal control unit). Delta-L will be used in connection with the Glovebox Integrated Microgravity Isolation Technology (g-LIMIT) inside the Microgravity Science Glovebox (MSG), onboard the International Space Station. This paper will describe the Delta-L imaging system. The Delta-L imaging system was designed to locate, resolve, and capture images of up to 10 individual crystals ranging in size from 10 to 500 microns with a point-to-point accuracy of +/- 2.0 microns within a quartz growth cell observation area of 20 mm x 10 mm x 1 mm. The optical imaging system is comprised of a video microscope camera mounted on computer controlled translation stages. The 3-axis translation stages and control units provide crewmembers the ability to search throughout the growth cell observation area for crystals forming in size of approximately 10 microns. Once the crewmember has selected ten crystals of interest, the growth of these crystals is tracked until the size reaches approximately 500 microns. In order to resolve these crystals an optical system with a magnification of 10X was designed. A black and white NTSC camera was utilized with a 20X microscope objective and a 0.5X custom designed relay lens with an inline light to meet the magnification requirement. The design allows a 500 pm crystal to be viewed in the vertical dimension on a standard NTSC monitor (4:3 aspect ratio). Images of the 10 crystals are collected periodically and stored in sets by the DACU.

Analytical relationships for prediction of the mechanical properties of additively manufactured porous biomaterials.

PubMed

Zadpoor, Amir Abbas; Hedayati, Reza

2016-12-01

Recent developments in additive manufacturing techniques have motivated an increasing number of researchers to study regular porous biomaterials that are based on repeating unit cells. The physical and mechanical properties of such porous biomaterials have therefore received increasing attention during recent years. One of the areas that have revived is analytical study of the mechanical behavior of regular porous biomaterials with the aim of deriving analytical relationships that could predict the relative density and mechanical properties of porous biomaterials, given the design and dimensions of their repeating unit cells. In this article, we review the analytical relationships that have been presented in the literature for predicting the relative density, elastic modulus, Poisson's ratio, yield stress, and buckling limit of regular porous structures based on various types of unit cells. The reviewed analytical relationships are used to compare the mechanical properties of porous biomaterials based on different types of unit cells. The major areas where the analytical relationships have improved during the recent years are discussed and suggestions are made for future research directions. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 3164-3174, 2016. © 2016 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc.

Design criteria for small coded aperture masks in gamma-ray astronomy

NASA Technical Reports Server (NTRS)

Sembay, S.; Gehrels, Neil

1990-01-01

Most theoretical work on coded aperture masks in X-ray and low-energy gamma-ray astronomy has concentrated on masks with large numbers of elements. For gamma-ray spectrometers in the MeV range, the detector plane usually has only a few discrete elements, so that masks with small numbers of elements are called for. For this case it is feasible to analyze by computer all the possible mask patterns of given dimension to find the ones that best satisfy the desired performance criteria. A particular set of performance criteria for comparing the flux sensitivities, source positioning accuracies and transparencies of different mask patterns is developed. The results of such a computer analysis for masks up to dimension 5 x 5 unit cell are presented and it is concluded that there is a great deal of flexibility in the choice of mask pattern for each dimension.

The Representation of Three-Dimensional Space in Fish

PubMed Central

Burt de Perera, Theresa; Holbrook, Robert I.; Davis, Victoria

2016-01-01

In mammals, the so-called “seat of the cognitive map” is located in place cells within the hippocampus. Recent work suggests that the shape of place cell fields might be defined by the animals’ natural movement; in rats the fields appear to be laterally compressed (meaning that the spatial map of the animal is more highly resolved in the horizontal dimensions than in the vertical), whereas the place cell fields of bats are statistically spherical (which should result in a spatial map that is equally resolved in all three dimensions). It follows that navigational error should be equal in the horizontal and vertical dimensions in animals that travel freely through volumes, whereas in surface-bound animals would demonstrate greater vertical error. Here, we describe behavioral experiments on pelagic fish in which we investigated the way that fish encode three-dimensional space and we make inferences about the underlying processing. Our work suggests that fish, like mammals, have a higher order representation of space that assembles incoming sensory information into a neural unit that can be used to determine position and heading in three-dimensions. Further, our results are consistent with this representation being encoded isotropically, as would be expected for animals that move freely through volumes. Definitive evidence for spherical place fields in fish will not only reveal the neural correlates of space to be a deep seated vertebrate trait, but will also help address the questions of the degree to which environment spatial ecology has shaped cognitive processes and their underlying neural mechanisms. PMID:27014002

Mechanics of additively manufactured porous biomaterials based on the rhombicuboctahedron unit cell.

PubMed

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

2016-01-01

Thanks to recent developments in additive manufacturing techniques, it is now possible to fabricate porous biomaterials with arbitrarily complex micro-architectures. Micro-architectures of such biomaterials determine their physical and biological properties, meaning that one could potentially improve the performance of such biomaterials through rational design of micro-architecture. The relationship between the micro-architecture of porous biomaterials and their physical and biological properties has therefore received increasing attention recently. In this paper, we studied the mechanical properties of porous biomaterials made from a relatively unexplored unit cell, namely rhombicuboctahedron. We derived analytical relationships that relate the micro-architecture of such porous biomaterials, i.e. the dimensions of the rhombicuboctahedron unit cell, to their elastic modulus, Poisson's ratio, and yield stress. Finite element models were also developed to validate the analytical solutions. Analytical and numerical results were compared with experimental data from one of our recent studies. It was found that analytical solutions and numerical results show a very good agreement particularly for smaller values of apparent density. The elastic moduli predicted by analytical and numerical models were in very good agreement with experimental observations too. While in excellent agreement with each other, analytical and numerical models somewhat over-predicted the yield stress of the porous structures as compared to experimental data. As the ratio of the vertical struts to the inclined struts, α, approaches zero and infinity, the rhombicuboctahedron unit cell respectively approaches the octahedron (or truncated cube) and cube unit cells. For those limits, the analytical solutions presented here were found to approach the analytic solutions obtained for the octahedron, truncated cube, and cube unit cells, meaning that the presented solutions are generalizations of the analytical solutions obtained for several other types of porous biomaterials. Copyright © 2015 Elsevier Ltd. All rights reserved.

Clay Mineral Crystal Structure Tied to Composition

NASA Image and Video Library

2016-12-13

This diagram illustrates how the dimensions of clay minerals' crystal structure are affected by which ions are present in the composition of the mineral. Different clay minerals were identified this way at two sites in Mars' Gale Crater: "Murray Buttes" and "Yellowknife Bay." In otherwise identical clay minerals, a composition that includes aluminum and ferric iron ions (red dots) results in slightly smaller crystalline unit cells than one that instead includes magnesium and ferrous iron ions (green dots). Ferric iron is more highly oxidized than ferrous iron. Crystalline cell units are the basic repeating building blocks that define minerals. X-ray diffraction analysis, a capability of the Chemistry and Mineralogy (CheMin) instrument on NASA's Curiosity Mars rover, identifies minerals from their crystalline structure. http://photojournal.jpl.nasa.gov/catalog/PIA21148

Yolk-platelet crystals in three ancient bony fishes: Polypterus bichir (Polypteri), Amia calva L., and Lepisosteus osseus (L.) (Holostei).

PubMed

Lange, R H; Grodziński, Z; Kilarski, W

1982-01-01

Yolk-platelet crystals in Amia calva L., Lepisosteus osseus (L.) and Polypterus bichir have orthorhombic features with unit-cell dimensions a = 8.3 ... 8.8 nm, b = 16.4 ... 16.9 nm and c = 18.6 ... 19.8 nm as determined in electron-diffracted patterns of fixed, epoxy-resin embedded and thin-sectioned material. Electron-diffraction patterns, crystal projections and the above unit-cell data make them extremely similar to the orthorhombic yolk-platelet crystals known for amphibians and teleosts. This observation fills a gap in yolk-platelet research and supports the view that the general architecture of yolk platelets has been conserved for nearly 400 million years. It follows that the peculiar platelet architecture itself has physiological significance.

Light-dependent governance of cell shape dimensions in cyanobacteria.

PubMed

Montgomery, Beronda L

2015-01-01

The regulation of cellular dimension is important for the function and survival of cells. Cellular dimensions, such as size and shape, are regulated throughout the life cycle of bacteria and can be adapted in response to environmental changes to fine-tune cellular fitness. Cell size and shape are generally coordinated with cell growth and division. Cytoskeletal regulation of cell shape and cell wall biosynthesis and/or deposition occurs in a range of organisms. Photosynthetic organisms, such as cyanobacteria, particularly exhibit light-dependent regulation of morphogenes and generation of reactive oxygen species and other signals that can impact cellular dimensions. Environmental signals initiate adjustments of cellular dimensions, which may be vitally important for optimizing resource acquisition and utilization or for coupling the cellular dimensions with the regulation of subcellular organization to maintain optimal metabolism. Although the involvement of cytoskeletal components in the regulation of cell shape is widely accepted, the signaling factors that regulate cytoskeletal and other distinct components involved in cell shape control, particularly in response to changes in external light cues, remain to be fully elucidated. In this review, factors impacting the inter-coordination of growth and division, the relationship between the regulation of cellular dimensions and central carbon metabolism, and consideration of the effects of specific environment signals, primarily light, on cell dimensions in cyanobacteria will be discussed. Current knowledge about the molecular bases of the light-dependent regulation of cellular dimensions and cell shape in cyanobacteria will be highlighted.

Filling in the GAPS: evaluating completeness and coverage of open-access biodiversity databases in the United States

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

Troia, Matthew J.; McManamay, Ryan A.

Primary biodiversity data constitute observations of particular species at given points in time and space. Open-access electronic databases provide unprecedented access to these data, but their usefulness in characterizing species distributions and patterns in biodiversity depend on how complete species inventories are at a given survey location and how uniformly distributed survey locations are along dimensions of time, space, and environment. Our aim was to compare completeness and coverage among three open-access databases representing ten taxonomic groups (amphibians, birds, freshwater bivalves, crayfish, freshwater fish, fungi, insects, mammals, plants, and reptiles) in the contiguous United States. We compiled occurrence records frommore » the Global Biodiversity Information Facility (GBIF), the North American Breeding Bird Survey (BBS), and federally administered fish surveys (FFS). In this study, we aggregated occurrence records by 0.1° × 0.1° grid cells and computed three completeness metrics to classify each grid cell as well-surveyed or not. Next, we compared frequency distributions of surveyed grid cells to background environmental conditions in a GIS and performed Kolmogorov–Smirnov tests to quantify coverage through time, along two spatial gradients, and along eight environmental gradients. The three databases contributed >13.6 million reliable occurrence records distributed among >190,000 grid cells. The percent of well-surveyed grid cells was substantially lower for GBIF (5.2%) than for systematic surveys (BBS and FFS; 82.5%). Still, the large number of GBIF occurrence records produced at least 250 well-surveyed grid cells for six of nine taxonomic groups. Coverages of systematic surveys were less biased across spatial and environmental dimensions but were more biased in temporal coverage compared to GBIF data. GBIF coverages also varied among taxonomic groups, consistent with commonly recognized geographic, environmental, and institutional sampling biases. Lastly, this comprehensive assessment of biodiversity data across the contiguous United States provides a prioritization scheme to fill in the gaps by contributing existing occurrence records to the public domain and planning future surveys.« less

Filling in the GAPS: evaluating completeness and coverage of open-access biodiversity databases in the United States

DOE PAGES

Troia, Matthew J.; McManamay, Ryan A.

2016-06-12

Primary biodiversity data constitute observations of particular species at given points in time and space. Open-access electronic databases provide unprecedented access to these data, but their usefulness in characterizing species distributions and patterns in biodiversity depend on how complete species inventories are at a given survey location and how uniformly distributed survey locations are along dimensions of time, space, and environment. Our aim was to compare completeness and coverage among three open-access databases representing ten taxonomic groups (amphibians, birds, freshwater bivalves, crayfish, freshwater fish, fungi, insects, mammals, plants, and reptiles) in the contiguous United States. We compiled occurrence records frommore » the Global Biodiversity Information Facility (GBIF), the North American Breeding Bird Survey (BBS), and federally administered fish surveys (FFS). In this study, we aggregated occurrence records by 0.1° × 0.1° grid cells and computed three completeness metrics to classify each grid cell as well-surveyed or not. Next, we compared frequency distributions of surveyed grid cells to background environmental conditions in a GIS and performed Kolmogorov–Smirnov tests to quantify coverage through time, along two spatial gradients, and along eight environmental gradients. The three databases contributed >13.6 million reliable occurrence records distributed among >190,000 grid cells. The percent of well-surveyed grid cells was substantially lower for GBIF (5.2%) than for systematic surveys (BBS and FFS; 82.5%). Still, the large number of GBIF occurrence records produced at least 250 well-surveyed grid cells for six of nine taxonomic groups. Coverages of systematic surveys were less biased across spatial and environmental dimensions but were more biased in temporal coverage compared to GBIF data. GBIF coverages also varied among taxonomic groups, consistent with commonly recognized geographic, environmental, and institutional sampling biases. Lastly, this comprehensive assessment of biodiversity data across the contiguous United States provides a prioritization scheme to fill in the gaps by contributing existing occurrence records to the public domain and planning future surveys.« less

Enantioselective Synthesis of Strobamine and its Analogues

DTIC Science & Technology

2010-01-01

of bis[(R,R)- or (S,S)- phenylethylamine ]·HCl (0.30 g, 1.2 mmol) in dry THF (28 mL) at 0 °C. The resulting mixture was stirred at 0 °C for 1 h, then...absorption effects . The crystal was orthorhombic in space group P21212 with unit cell dimensions a = 11.2517(6) Å, b = 21.5455(12) Å, c = 6.5032(4) Å

Crystallization and preliminary X-ray diffraction analysis of a novel Arg49 phospholipase A{sub 2} homologue from Zhaoermia mangshanensis venom

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

Murakami, Mário T.; Center for Applied Toxinology, CAT-CEPID, São Paulo, SP; Advanced Center for Genomics and Proteomics, UNESP-State University of São Paulo, São José do Rio Preto 15054-000

2007-07-01

A single crystal of zhaoermiatoxin with maximum dimensions of 0.2 × 0.2 × 0.5 mm was used for X-ray diffraction data collection to a resolution of 2.05 Å using synchrotron radiation and the diffraction pattern was indexed in the hexagonal space group P6{sub 4}, with unit-cell parameters a = 72.9, b = 72.9, c = 93.9 Å. Zhaoermiatoxin, an Arg49 phospholipase A{sub 2} homologue from Zhaoermia mangshanensis (formerly Trimeresurus mangshanensis, Ermia mangshanensis) venom is a novel member of the PLA{sub 2}-homologue family that possesses an arginine residue at position 49, probably arising from a secondary Lys49→Arg substitution that does notmore » alter the catalytic inactivity towards phospholipids. Like other Lys49 PLA{sub 2} homologues, zhaoermiatoxin induces oedema and strong myonecrosis without detectable PLA{sub 2} catalytic activity. A single crystal with maximum dimensions of 0.2 × 0.2 × 0.5 mm was used for X-ray diffraction data collection to a resolution of 2.05 Å using synchrotron radiation and the diffraction pattern was indexed in the hexagonal space group P6{sub 4}, with unit-cell parameters a = 72.9, b = 72.9, c = 93.9 Å.« less

BRLSC: An Advanced Eulerian Code for Predicting Shaped Charges. Volume 1

DTIC Science & Technology

1975-12-01

of cell. sec sec sec cm 124 J 𔃽 Variable Name Location Dimension Units Definition ECK ■2(76)- -1 -f n n EMI.V »Z(8S) EMOB =Z...energy sum: (2-r Ek - ETI1 j/ETII; where E^ is total energy in cell K. If | ECK | > DMIN, execution is stopped. INPUT parameter. Mininum specific...NMXCLS 74. BBOUND 75. UN 7 5 76. ECK 77. NECYCL 78. NTPMX 79. UN 7 9 80. UVMAX 81. NTCC 82. UN S 2 83. IVARDX 84. T Sb. EM IN S6. PMIN

GUIDING PRINCIPLES FOR GOOD PRACTICES IN HOSPITAL-BASED HEALTH TECHNOLOGY ASSESSMENT UNITS.

PubMed

Sampietro-Colom, Laura; Lach, Krzysztof; Pasternack, Iris; Wasserfallen, Jean-Blaise; Cicchetti, Americo; Marchetti, Marco; Kidholm, Kristian; Arentz-Hansen, Helene; Rosenmöller, Magdalene; Wild, Claudia; Kahveci, Rabia; Ulst, Margus

2015-01-01

Health technology assessment (HTA) carried out for policy decision making has well-established principles unlike hospital-based HTA (HB-HTA), which differs from the former in the context characteristics and ways of operation. This study proposes principles for good practices in HB-HTA units. A framework for good practice criteria was built inspired by the EFQM excellence business model and information from six literature reviews, 107 face-to-face interviews, forty case studies, large-scale survey, focus group, Delphi survey, as well as local and international validation. In total, 385 people from twenty countries have participated in defining the principles for good practices in HB-HTA units. Fifteen guiding principles for good practices in HB-HTA units are grouped in four dimensions. Dimension 1 deals with principles of the assessment process aimed at providing contextualized information for hospital decision makers. Dimension 2 describes leadership, strategy and partnerships of HB-HTA units which govern and facilitate the assessment process. Dimension 3 focuses on adequate resources that ensure the operation of HB-HTA units. Dimension 4 deals with measuring the short- and long-term impact of the overall performance of HB-HTA units. Finally, nine core guiding principles were selected as essential requirements for HB-HTA units based on the expertise of the HB-HTA units participating in the project. Guiding principles for good practices set up a benchmark for HB-HTA because they represent the ideal performance of HB-HTA units; nevertheless, when performing HTA at hospital level, context also matters; therefore, they should be adapted to ensure their applicability in the local context.

A Negative Index Metamaterial-Inspired UWB Antenna with an Integration of Complementary SRR and CLS Unit Cells for Microwave Imaging Sensor Applications

PubMed Central

Islam, Mohammad Tariqul; Islam, Md. Moinul; Samsuzzaman, Md.; Faruque, Mohammad Rashed Iqbal; Misran, Norbahiah

2015-01-01

This paper presents a negative index metamaterial incorporated UWB antenna with an integration of complementary SRR (split-ring resonator) and CLS (capacitive loaded strip) unit cells for microwave imaging sensor applications. This metamaterial UWB antenna sensor consists of four unit cells along one axis, where each unit cell incorporates a complementary SRR and CLS pair. This integration enables a design layout that allows both a negative value of permittivity and a negative value of permeability simultaneous, resulting in a durable negative index to enhance the antenna sensor performance for microwave imaging sensor applications. The proposed MTM antenna sensor was designed and fabricated on an FR4 substrate having a thickness of 1.6 mm and a dielectric constant of 4.6. The electrical dimensions of this antenna sensor are 0.20 λ × 0.29 λ at a lower frequency of 3.1 GHz. This antenna sensor achieves a 131.5% bandwidth (VSWR < 2) covering the frequency bands from 3.1 GHz to more than 15 GHz with a maximum gain of 6.57 dBi. High fidelity factor and gain, smooth surface-current distribution and nearly omni-directional radiation patterns with low cross-polarization confirm that the proposed negative index UWB antenna is a promising entrant in the field of microwave imaging sensors. PMID:26007721

A Negative Index Metamaterial-Inspired UWB Antenna with an Integration of Complementary SRR and CLS Unit Cells for Microwave Imaging Sensor Applications.

PubMed

Islam, Mohammad Tariqul; Islam, Md Moinul; Samsuzzaman, Md; Faruque, Mohammad Rashed Iqbal; Misran, Norbahiah

2015-05-20

This paper presents a negative index metamaterial incorporated UWB antenna with an integration of complementary SRR (split-ring resonator) and CLS (capacitive loaded strip) unit cells for microwave imaging sensor applications. This metamaterial UWB antenna sensor consists of four unit cells along one axis, where each unit cell incorporates a complementary SRR and CLS pair. This integration enables a design layout that allows both a negative value of permittivity and a negative value of permeability simultaneous, resulting in a durable negative index to enhance the antenna sensor performance for microwave imaging sensor applications. The proposed MTM antenna sensor was designed and fabricated on an FR4 substrate having a thickness of 1.6 mm and a dielectric constant of 4.6. The electrical dimensions of this antenna sensor are 0.20 λ × 0.29 λ at a lower frequency of 3.1 GHz. This antenna sensor achieves a 131.5% bandwidth (VSWR < 2) covering the frequency bands from 3.1 GHz to more than 15 GHz with a maximum gain of 6.57 dBi. High fidelity factor and gain, smooth surface-current distribution and nearly omni-directional radiation patterns with low cross-polarization confirm that the proposed negative index UWB antenna is a promising entrant in the field of microwave imaging sensors.

A Miniaturized Antenna with Negative Index Metamaterial Based on Modified SRR and CLS Unit Cell for UWB Microwave Imaging Applications.

PubMed

Islam, Md Moinul; Islam, Mohammad Tariqul; Samsuzzaman, Md; Faruque, Mohammad Rashed Iqbal; Misran, Norbahiah; Mansor, Mohd Fais

2015-01-23

A miniaturized antenna employing a negative index metamaterial with modified split-ring resonator (SRR) and capacitance-loaded strip (CLS) unit cells is presented for Ultra wideband (UWB) microwave imaging applications. Four left-handed (LH) metamaterial (MTM) unit cells are located along one axis of the antenna as the radiating element. Each left-handed metamaterial unit cell combines a modified split-ring resonator (SRR) with a capacitance-loaded strip (CLS) to obtain a design architecture that simultaneously exhibits both negative permittivity and negative permeability, which ensures a stable negative refractive index to improve the antenna performance for microwave imaging. The antenna structure, with dimension of 16 × 21 × 1.6 mm³, is printed on a low dielectric FR4 material with a slotted ground plane and a microstrip feed. The measured reflection coefficient demonstrates that this antenna attains 114.5% bandwidth covering the frequency band of 3.4-12.5 GHz for a voltage standing wave ratio of less than 2 with a maximum gain of 5.16 dBi at 10.15 GHz. There is a stable harmony between the simulated and measured results that indicate improved nearly omni-directional radiation characteristics within the operational frequency band. The stable surface current distribution, negative refractive index characteristic, considerable gain and radiation properties make this proposed negative index metamaterial antenna optimal for UWB microwave imaging applications.

Negative extensibility metamaterials: phase diagram calculation

NASA Astrophysics Data System (ADS)

Klein, John T.; Karpov, Eduard G.

2017-12-01

Negative extensibility metamaterials are able to contract against the line of increasing external tension. A bistable unit cell exhibits several nonlinear mechanical behaviors including the negative extensibility response. Here, an exact form of the total mechanical potential is used based on engineering strain measure. The mechanical response is a function of the system parameters that specify unit cell dimensions and member stiffnesses. A phase diagram is calculated, which maps the response to regions in the diagram using the system parameters as the coordinate axes. Boundary lines pinpoint the onset of a particular mechanical response. Contour lines allow various material properties to be fine-tuned. Analogous to thermodynamic phase diagrams, there exist singular "triple points" which simultaneously satisfy conditions for three response types. The discussion ends with a brief statement about how thermodynamic phase diagrams differ from the phase diagram in this paper.

Microwave metamaterials made by fused deposition 3D printing of a highly conductive copper-based filament

NASA Astrophysics Data System (ADS)

Xie, Yangbo; Ye, Shengrong; Reyes, Christopher; Sithikong, Pariya; Popa, Bogdan-Ioan; Wiley, Benjamin J.; Cummer, Steven A.

2017-05-01

This work reports a method for fabricating three-dimensional microwave metamaterials by fused deposition modeling 3D printing of a highly conductive polymer composite filament. The conductivity of such a filament is shown to be nearly equivalent to that of a perfect conductor for microwave metamaterial applications. The expanded degrees-of-freedom made available by 3D metamaterial designs are demonstrated by designing, fabricating, and testing a 3D-printed unit cell with a broadband permittivity as high as 14.4. The measured and simulated S-parameters agree well with a mean squared error smaller than 0.1. The presented method not only allows reliable and convenient fabrication of microwave metamaterials with high conductivity but also opens the door to exploiting the third dimension of the unit cell design space to achieve enhanced electromagnetic properties.

On domain symmetry and its use in homogenization

DOE PAGES

Barbarosie, Cristian A.; Tortorelli, Daniel A.; Watts, Seth E.

2017-03-08

The present study focuses on solving partial differential equations in domains exhibiting symmetries and periodic boundary conditions for the purpose of homogenization. We show in a systematic manner how the symmetry can be exploited to significantly reduce the complexity of the problem and the computational burden. This is especially relevant in inverse problems, when one needs to solve the partial differential equation (the primal problem) many times in an optimization algorithm. The main motivation of our study is inverse homogenization used to design architected composite materials with novel properties which are being fabricated at ever increasing rates thanks to recentmore » advances in additive manufacturing. For example, one may optimize the morphology of a two-phase composite unit cell to achieve isotropic homogenized properties with maximal bulk modulus and minimal Poisson ratio. Typically, the isotropy is enforced by applying constraints to the optimization problem. However, in two dimensions, one can alternatively optimize the morphology of an equilateral triangle and then rotate and reflect the triangle to form a space filling D 3 symmetric hexagonal unit cell that necessarily exhibits isotropic homogenized properties. One can further use this D 3 symmetry to reduce the computational expense by performing the “unit strain” periodic boundary condition simulations on the single triangle symmetry sector rather than the six fold larger hexagon. In this paper we use group representation theory to derive the necessary periodic boundary conditions on the symmetry sectors of unit cells. The developments are done in a general setting, and specialized to the two-dimensional dihedral symmetries of the abelian D 2, i.e. orthotropic, square unit cell and nonabelian D 3, i.e. trigonal, hexagon unit cell. We then demonstrate how this theory can be applied by evaluating the homogenized properties of a two-phase planar composite over the triangle symmetry sector of a D 3 symmetric hexagonal unit cell.« less

Characterization and Measurement of Passive and Active Metamaterial Devices

DTIC Science & Technology

2010-03-01

A periodic bound- ary mirrors the computational domain along an axis. Unit cell boundary conditions mirror the computational domain along two axes... mirrored a number of times in each direction to create a square matrix of ring resonators. Figure 33(b) shows a 4× 4 array. The frequency domain...created by mirroring the previous structure three times. Thus, the dimensions of the particles are identical. The same boundary conditions and spacing

Molecular characterization of organic electronic films.

PubMed

DeLongchamp, Dean M; Kline, R Joseph; Fischer, Daniel A; Richter, Lee J; Toney, Michael F

2011-01-18

Organic electronics have emerged as a viable competitor to amorphous silicon for the active layer in low-cost electronics. The critical performance of organic electronic materials is closely related to their morphology and molecular packing. Unlike their inorganic counterparts, polymers combine complex repeat unit structure and crystalline disorder. This combination prevents any single technique from being able to uniquely solve the packing arrangement of the molecules. Here, a general methodology for combining multiple, complementary techniques that provide accurate unit cell dimensions and molecular orientation is described. The combination of measurements results in a nearly complete picture of the organic film morphology. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fabrication of 3D Reconstituted Organoid Arrays by DNA-programmed Assembly of Cells (DPAC)

PubMed Central

Todhunter, Michael E; Weber, Robert J; Farlow, Justin; Jee, Noel Y; Cerchiari, Alec E; Gartner, Zev J

2016-01-01

Tissues are the organizational units of function in metazoan organisms. Tissues comprise an assortment of cellular building blocks, soluble factors, and extracellular matrix (ECM) that are composed into specific three dimensional (3D) structures. The capacity to reconstitute tissues in vitro with the structural complexity observed in vivo is key to understanding processes such as morphogenesis, homeostasis, and disease. In this unit, we describe DNA-programmed Assembly of Cells (DPAC), a method to fabricate viable, functional arrays of organoid-like tissues within 3D ECM gels. In DPAC, dissociated cells are chemically functionalized with degradable oligonucleotide “velcro,” allowing rapid, specific, and reversible cell adhesion to a two-dimensional (2D) template patterned with complementary DNA. An iterative assembly process builds up organoids, layer-by-layer, from this initial 2D template and into the third dimension. Cleavage of the DNA releases the completed array of tissues that are captured and fully embedded in ECM gels for culture and observation. DPAC controls the size, shape, composition, and spatial heterogeneity of organoids, and permits positioning constituent cells with single-cell resolution even within cultures several centimeters long. PMID:27622567

Surface structure of Bi2Sr2CaCu2O(8+delta) high-temperature superconductors studied using low-energy electron diffraction

NASA Astrophysics Data System (ADS)

Lindberg, P. A. P.; Shen, Z.-X.; Wells, B. O.; Mitzi, D. B.; Lindau, I.

1988-12-01

The surface structure of Bi2Sr2CaCu2O(8+delta) has been studied using low-energy electron diffraction (LEED). Sharp diffraction spots indicative of a well-ordered surface are observed. The LEED patterns unequivocally show that this type of material preferentially cleaves along the a-b planes of the nearly tetragonal unit cell. A superstructure extending along one of the axes in the a-b plane (b) is found to have a periodicity of 27 + or - 0.5 A, in good agreement with earlier studies of the three-dimensional crystal structure. The superstructure at the surface is nonlocal in character and reflects the long-range superlattice of the bulk along the b axis. Intensity modulations of the diffraction spots oriented along the b axis are also reported and discussed in terms of the cell dimension of the unit cell along the b axis.

Towards 3D mapping of BO₆ octahedron rotations at perovskite heterointerfaces, unit cell by unit cell

DOE PAGES

He, Qian; Ishikawa, Ryo; Lupini, Andrew R.; ...

2015-07-15

The rich functionalities in the ABO₃ perovskite oxides originate at least partly from the ability of the corner-connected BO₆ octahedral network to host a large variety of cations through distortions and rotations. Characterizing these rotations, which significantly affect both fundamental aspects of materials behavior and possible applications, remains a major challenge. In this work, we have developed a unique method of investigating BO₆ rotation patterns in complex oxides ABO₃ with unit cell resolution at heterointerfaces, where novel properties often emerge. Our method involves column shape analysis in annular bright field - scanning transmission electron microscope images of the ABO₃ heterointerfacesmore » taken in specific orientations. The rotating phase of BO₆ octahedra can be identified for all three spatial dimensions without the need of case-by-case simulation. In several common rotation systems, it is now possible to quantitatively measure all three rotation angles. With this method, we examined interfaces between perovskites with distinct tilt systems as well as interfaces between tilted and untilted perovskites, identifying an unusual coupling behavior at the CaTiO₃/LSAT interface. We believe this unique method will significantly improve our knowledge of the complex oxide heterointerfaces.« less

Development of a Chemically Reacting Flow Solver on the Graphic Processing Units

DTIC Science & Technology

2011-05-10

been implemented on the GPU by Schive et al. (2010). The outcome of their work is the GAMER code for astrophysical simulation. Thibault and...Euler equations at each cell. For simplification, consider the Euler equations in one dimension with no source terms; the discretized form of the...is known to be more diffusive than the other fluxes due to the large bound of the numerical signal velocities: b+, b-. 3.4 Time Marching Methods

Tuning and synthesis of metallic nanostructures by mechanical compression

DOEpatents

Fan, Hongyou; Li, Binsong

2015-11-17

The present invention provides a pressure-induced phase transformation process to engineer metal nanoparticle architectures and to fabricate new nanostructured materials. The reversible changes of the nanoparticle unit cell dimension under pressure allow precise control over interparticle separation in 2D or 3D nanoparticle assemblies, offering unique robustness for interrogation of both quantum and classic coupling interactions. Irreversible changes above a threshold pressure of about 8 GPa enables new nanostructures, such as nanorods, nanowires, or nanosheets.

Crystal structures, in-silico study and anti-microbial potential of synthetic monocarbonyl curcuminoids

NASA Astrophysics Data System (ADS)

Ud Din, Zia; Serrano, N. F. G.; Ademi, Kastriot; Sousa, C. P.; Deflon, Victor Marcelo; Maia, Pedro Ivo da Silva; Rodrigues-Filho, Edson

2017-09-01

In this work the screening of 20 unsymmetrical chalcone and curcuminoids analogues in regard of their antimicrobial properties was conducted. Electron donating groups in the aromatic rings in the chalcone and curcuminoid derivatives produced higher antimicrobial effect. Compounds 1, 9 and 15 exhibited good activity against Escherichia coli and Staphylococcus aureus. These compounds were further evaluated against nine micro-organisms of pathological interest. Pharmmaper was used for target fishing of compounds against important bacterial targets. Molecular Docking helped to verify the results of these compounds against the selected bacterial target D-alanyl-D-alanine carboxypeptidase (PDB ID: 1PW1). The crystal structure of ligand and docked conformers in the active site of 1PW1 were analyzed. As a result structure-activity relationships are proposed. Structures of compounds 14 and 16 were obtained through single crystals X-ray diffraction studies. Compound 14 crystallizes in monoclinic space group P21/c with unit cell dimensions a = 13.1293(3) Å, b = 17.5364(4) Å, c = 15.1433(3) Å, β = 95.6440(10), V = 3469.70(13) Å3 and Z = 8. Compound 16 crystallizes in triclinic space group Pī with unit cell dimensions a = 6.8226(4) Å, b = 7.2256(4) Å, c = 18.1235(12) Å, β = 87.322(4), V = 850.57(9) Å3 and Z = 2.

IOTA: integration optimization, triage and analysis tool for the processing of XFEL diffraction images.

PubMed

Lyubimov, Artem Y; Uervirojnangkoorn, Monarin; Zeldin, Oliver B; Brewster, Aaron S; Murray, Thomas D; Sauter, Nicholas K; Berger, James M; Weis, William I; Brunger, Axel T

2016-06-01

Serial femtosecond crystallography (SFX) uses an X-ray free-electron laser to extract diffraction data from crystals not amenable to conventional X-ray light sources owing to their small size or radiation sensitivity. However, a limitation of SFX is the high variability of the diffraction images that are obtained. As a result, it is often difficult to determine optimal indexing and integration parameters for the individual diffraction images. Presented here is a software package, called IOTA , which uses a grid-search technique to determine optimal spot-finding parameters that can in turn affect the success of indexing and the quality of integration on an image-by-image basis. Integration results can be filtered using a priori information about the Bravais lattice and unit-cell dimensions and analyzed for unit-cell isomorphism, facilitating an improvement in subsequent data-processing steps.

Conceptual Model of Quantities, Units, Dimensions, and Values

NASA Technical Reports Server (NTRS)

Rouquette, Nicolas F.; DeKoenig, Hans-Peter; Burkhart, Roger; Espinoza, Huascar

2011-01-01

JPL collaborated with experts from industry and other organizations to develop a conceptual model of quantities, units, dimensions, and values based on the current work of the ISO 80000 committee revising the International System of Units & Quantities based on the International Vocabulary of Metrology (VIM). By providing support for ISO 80000 in SysML via the International Vocabulary of Metrology (VIM), this conceptual model provides, for the first time, a standard-based approach for addressing issues of unit coherence and dimensional analysis into the practice of systems engineering with SysML-based tools. This conceptual model provides support for two kinds of analyses specified in the International Vocabulary of Metrology (VIM): coherence of units as well as of systems of units, and dimension analysis of systems of quantities. To provide a solid and stable foundation, the model for defining quantities, units, dimensions, and values in SysML is explicitly based on the concepts defined in VIM. At the same time, the model library is designed in such a way that extensions to the ISQ (International System of Quantities) and SI Units (Systeme International d Unites) can be represented, as well as any alternative systems of quantities and units. The model library can be used to support SysML user models in various ways. A simple approach is to define and document libraries of reusable systems of units and quantities for reuse across multiple projects, and to link units and quantity kinds from these libraries to Unit and QuantityKind stereotypes defined in SysML user models.

A Miniaturized Antenna with Negative Index Metamaterial Based on Modified SRR and CLS Unit Cell for UWB Microwave Imaging Applications

PubMed Central

Islam, Md. Moinul; Islam, Mohammad Tariqul; Samsuzzaman, Md.; Faruque, Mohammad Rashed Iqbal; Misran, Norbahiah; Mansor, Mohd Fais

2015-01-01

A miniaturized antenna employing a negative index metamaterial with modified split-ring resonator (SRR) and capacitance-loaded strip (CLS) unit cells is presented for Ultra wideband (UWB) microwave imaging applications. Four left-handed (LH) metamaterial (MTM) unit cells are located along one axis of the antenna as the radiating element. Each left-handed metamaterial unit cell combines a modified split-ring resonator (SRR) with a capacitance-loaded strip (CLS) to obtain a design architecture that simultaneously exhibits both negative permittivity and negative permeability, which ensures a stable negative refractive index to improve the antenna performance for microwave imaging. The antenna structure, with dimension of 16 × 21 × 1.6 mm3, is printed on a low dielectric FR4 material with a slotted ground plane and a microstrip feed. The measured reflection coefficient demonstrates that this antenna attains 114.5% bandwidth covering the frequency band of 3.4–12.5 GHz for a voltage standing wave ratio of less than 2 with a maximum gain of 5.16 dBi at 10.15 GHz. There is a stable harmony between the simulated and measured results that indicate improved nearly omni-directional radiation characteristics within the operational frequency band. The stable surface current distribution, negative refractive index characteristic, considerable gain and radiation properties make this proposed negative index metamaterial antenna optimal for UWB microwave imaging applications. PMID:28787945

High temperature hydrothermal synthesis of rare-earth titanates: synthesis and structure of RE5Ti4O15(OH) (RE = La, Er), Sm3TiO5(OH)3, RE5Ti2O11(OH) (RE = Tm-Lu) and Ce2Ti4O11.

PubMed

Fulle, Kyle; Sanjeewa, Liurukara D; McMillen, Colin D; Kolis, Joseph W

2018-05-15

Reactions of rare-earth oxides with TiO2 were performed in high temperature (650-700 °C) hydrothermal fluids. Two different mineralizer fluids were examined, 20 M KOH and 30 M CsF, and their respective products analyzed. When concentrated KOH fluids were used, single crystals of a variety of new OH- containing species were isolated and structurally characterized: RE5Ti4O15(OH) (RE = La, Er) I, Sm3TiO5(OH)3II and RE5Ti2O11(OH) (RE = Tm-Lu) III. La5Ti4O15(OH) I crystallizes in the orthorhombic space group Pnnm with unit cell dimensions of a = 30.5152(12) Å, b = 5.5832(2) Å, c = 7.7590(3) Å and V = 1321.92(9) Å3, Z = 4. Sm3TiO5(OH)3II crystallizes in the monoclinic space group P21/m with unit cell parameters of a = 5.6066(2) Å, b = 10.4622(4) Å, c = 6.1258(2) Å and β = 104.7390(10)°, V = 347.50(2) Å3, Z = 2. Lu5Ti2O11(OH) III crystallizes in the monoclinic space group C2/m with unit cell dimensions of a = 12.1252(9) Å, b = 5.8243(4) Å, c = 7.0407(5) Å, β = 106.939(3)° and V = 475.65(6) Å3, Z = 2. When concentrated fluoride solutions are used, mostly RE2Ti2O7 type compounds were isolated in either cubic or monoclinic phases. In the case of cerium, Ce2Ti4O11IV was isolated that crystallizes in the monoclinic space group C2/c with unit cell parameters of a = 13.6875(7) Å, b = 5.0955(3) Å, c = 12.8592(7) Å, β = 108.964(2)° and V = 848.18(8) Å3, Z = 4. The synthesis, structural characterization, and supporting characterization are reported for all compounds. The work highlights the complementary nature of hydroxide and fluoride fluids in studying the reactivity of refractory oxides.

[Analysis of the safety culture in a Cardiology Unit managed by processes].

PubMed

Raso-Raso, Rafael; Uris-Selles, Joaquín; Nolasco-Bonmatí, Andreu; Grau-Jornet, Guillermo; Revert-Gandia, Rosa; Jiménez-Carreño, Rebeca; Sánchez-Soriano, Ruth M; Chamorro-Fernández, Carlos I; Marco-Francés, Elvira; Albero-Martínez, José V

2017-04-04

Safety culture is one of the requirements for preventing the occurrence of adverse effects. However, this has not been studied in the field of cardiology. The aim of this study is to evaluate the safety culture in a cardiology unit that has implemented and certified an integrated quality and risk management system for patient safety. A cross-sectional observational study was conducted in 2 consecutive years, with all staff completing the Spanish version of the questionnaire, "Hospital Survey on Patient Safety Culture" of the "Agency for Healthcare Research and Quality", with 42 items grouped into 12 dimensions. The percentage of positive responses in each dimension in 2014 and 2015 were compared, as well as national data and United States data, following the established rules. The overall assessment out of a possible 5, was 4.5 in 2014 and 4.7 in 2015. Seven dimensions were identified as strengths. The worst rated were: staffing, management support and teamwork between units. The comparison showed superiority in all dimensions compared to national data, and in 8 of them compared to American data. The safety culture in a Cardiology Unit with an integrated quality and risk management patient safety system is high, and higher than nationally in all its dimensions and in most of them compared to the United States. Copyright © 2017 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

Phase equilibria and crystal chemistry of rubidium niobates and rubidium tantalates

NASA Technical Reports Server (NTRS)

Minor, D. B.; Roth, R. S.; Parker, H. S.; Brower, W. S.

1977-01-01

The phase equilibria relations and crystal chemistry of portions of the Rb2O-Nb2O5 and Rb2O-Ta2O5 systems were investigated for structures potentially useful as ionic conductors. A hexagonal tungsten bronze-type (HTB) structure was found in both systems as well as three hexagonal phases with mixed HTB-pyrochlore type structures. Ion exchange experiments between various alkali ions are described for several phases. Unit cell dimensions and X-ray diffraction powder patterns are reported.

Problems with Generalising: Pythagoras in N Dimensions

ERIC Educational Resources Information Center

Foster, Colin

2013-01-01

Pythagoras' theorem in two and three dimensions appears in General Mathematics, Units 1-2, section 6 (Geometry and trigonometry: Shape and measurement) in the Victorian Certificate of Education Mathematics Study Design (Victorian Curriculum Assessment Authority, 2010). It also comes in Further Mathematics, Units 3-4 (Applications: Geometry and…

Optimization of solar cell contacts by system cost-per-watt minimization

NASA Technical Reports Server (NTRS)

Redfield, D.

1977-01-01

New, and considerably altered, optimum dimensions for solar-cell metallization patterns are found using the recently developed procedure whose optimization criterion is the minimum cost-per-watt effect on the entire photovoltaic system. It is also found that the optimum shadow fraction by the fine grid is independent of metal cost and resistivity as well as cell size. The optimum thickness of the fine grid metal depends on all these factors, and in familiar cases it should be appreciably greater than that found by less complete analyses. The optimum bus bar thickness is much greater than those generally used. The cost-per-watt penalty due to the need for increased amounts of metal per unit area on larger cells is determined quantitatively and thereby provides a criterion for the minimum benefits that must be obtained in other process steps to make larger cells cost effective.

The European Dimension in Education. Thematic Bibliography No. 1/96.

ERIC Educational Resources Information Center

EURYDICE European Unit, Brussels (Belgium).

This booklet provides a selection of the publications on the "European Dimension in Education" included in the documentary archives of the Eurydice European Unit. "European dimension" addresses those documents dealing with educational initiatives whose aim is to promote the European dimension in schools in the context of…

Comparative analysis of ex-situ and operando X-ray diffraction experiments for lithium insertion materials

NASA Astrophysics Data System (ADS)

Brant, William R.; Li, Dan; Gu, Qinfen; Schmid, Siegbert

2016-01-01

A comparative study of ex-situ and operando X-ray diffraction techniques using the fast lithium ion conductor Li0.18Sr0.66Ti0.5Nb0.5O3 is presented. Ex-situ analysis of synchrotron X-ray diffraction data suggests that a single phase material exists for all discharges to as low as 0.422 V. For samples discharged to 1 V or lower, i.e. with higher lithium content, it is possible to determine the lithium position from the X-ray data. However, operando X-ray diffraction from a coin cell reveals that a kinetically driven two phase region occurs during battery cycling below 1 V. Through monitoring the change in unit cell dimension during electrochemical cycling the dynamics of lithium insertion are explored. A reduction in the rate of unit cell expansion of 22(2)% part way through the first discharge and 13(1)% during the second discharge is observed. This reduction may be caused by a drop in lithium diffusion into the bulk material for higher lithium contents. A more significant change is a jump in the unit cell expansion by 60(2)% once the lithium content exceeds one lithium ion per vacant site. It is suggested that this jump is caused by damping of octahedral rotations, thus establishing a link between lithium content and octahedral rotations.

Friendships of Indonesian and United States Youth

ERIC Educational Resources Information Center

French, Doran C.; Pidada, Sri; Victor, Andrea

2005-01-01

Issues in the study of friendship across cultures were explored by reviewing a set of studies focusing on the friendships of Indonesian and United States youth. Four topics are considered: similarity of friendships across cultures, dimensions of friendships that vary across cultures, the utility of the individualism/collectivism dimension for…

What Does a Hospital Survey on Patient Safety Reveal About Patient Safety Culture of Surgical Units Compared With That of Other Units?

PubMed Central

Shu, Qin; Cai, Miao; Tao, Hong-bing; Cheng, Zhao-hui; Chen, Jing; Hu, Yin-huan; Li, Gang

2015-01-01

Abstract The objective of this study was to examine the strengths and weaknesses of surgical units as compared with other units, and to provide an opportunity to improve patient safety culture in surgical settings by suggesting targeted actions using Hospital Survey on Patient Safety Culture (HSOPSC) investigation. A Hospital Survey on Patient Safety questionnaire was conducted to physicians and nurses in a tertiary hospital in Shandong China. 12 patient safety culture dimensions and 2 outcome variables were measured. A total of 23.5% of respondents came from surgical units, and 76.5% worked in other units. The “overall perceptions of safety” (48.1% vs 40.4%, P < 0.001) and “frequency of events reported” (63.7% vs 60.7%, P = 0.001) of surgical units were higher than those of other units. However, the communication openness (38.7% vs 42.5%, P < 0.001) of surgical units was lower than in other units. Medical workers in surgical units reported more events than those in other units, and more respondents in the surgical units assess “patient safety grade” to be good/excellent. Three dimensions were considered as strengths, whereas 5 other dimensions were considered to be weaknesses in surgical units. Six dimensions have potential to aid in improving events reporting and patient safety grade. Appropriate working times will also contribute to ensuring patient safety. Medical staff with longer years of experience reported more events. Surgical units outperform the nonsurgical ones in overall perception of safety and the number of events reported but underperform in the openness of communication. Four strategies, namely deepening the understanding about patient safety of supervisors, narrowing the communication gap within and across clinical units, recruiting more workers, and employing the event reporting system and building a nonpunitive culture, are recommended to improve patient safety in surgical units in the context of 1 hospital. PMID:26166083

What Does a Hospital Survey on Patient Safety Reveal About Patient Safety Culture of Surgical Units Compared With That of Other Units?

PubMed

Shu, Qin; Cai, Miao; Tao, Hong-Bing; Cheng, Zhao-Hui; Chen, Jing; Hu, Yin-Huan; Li, Gang

2015-07-01

The objective of this study was to examine the strengths and weaknesses of surgical units as compared with other units, and to provide an opportunity to improve patient safety culture in surgical settings by suggesting targeted actions using Hospital Survey on Patient Safety Culture (HSOPSC) investigation.A Hospital Survey on Patient Safety questionnaire was conducted to physicians and nurses in a tertiary hospital in Shandong China. 12 patient safety culture dimensions and 2 outcome variables were measured.A total of 23.5% of respondents came from surgical units, and 76.5% worked in other units. The "overall perceptions of safety" (48.1% vs 40.4%, P < 0.001) and "frequency of events reported" (63.7% vs 60.7%, P = 0.001) of surgical units were higher than those of other units. However, the communication openness (38.7% vs 42.5%, P < 0.001) of surgical units was lower than in other units. Medical workers in surgical units reported more events than those in other units, and more respondents in the surgical units assess "patient safety grade" to be good/excellent. Three dimensions were considered as strengths, whereas 5 other dimensions were considered to be weaknesses in surgical units. Six dimensions have potential to aid in improving events reporting and patient safety grade. Appropriate working times will also contribute to ensuring patient safety. Medical staff with longer years of experience reported more events.Surgical units outperform the nonsurgical ones in overall perception of safety and the number of events reported but underperform in the openness of communication. Four strategies, namely deepening the understanding about patient safety of supervisors, narrowing the communication gap within and across clinical units, recruiting more workers, and employing the event reporting system and building a nonpunitive culture, are recommended to improve patient safety in surgical units in the context of 1 hospital.

Hardwood Dimension Stock and Furniture Parts Including Export Opportunities

Treesearch

Philip A. Araman; Fred Lamb

1990-01-01

This article gives a description of dimension stock and its uses as well as its marketing potential for Virginia and the United States. It also briefly explains the production process for dimension stock and furniture parts.

Crystallization of phycoerythrocyanin from the cyanobacterium Mastigocladus laminosus and preliminary characterization of two crystal forms.

PubMed

Rümbeli, R; Schirmer, T; Bode, W; Sidler, W; Zuber, H

1985-11-05

The light-harvesting protein phycoerythrocyanin from the cyanobacterium Mastigocladus laminosus Cohn has been crystallized in two different crystal forms by vapour diffusion. In 5% (w/v) polyethylene glycol at pH 8.5, hexagonal crystals of space group P63 with cell constants a = b = 158 A, c = 40.6 A were obtained, which turned out to be almost isomorphous with the hexagonal crystals of C-phycocyanin from the same organism. Consequently, the conformation of both phycobiliproteins must be very similar. From 1.5 M-ammonium sulfate (pH 8.5), orthorhombic crystals of space group P2221 with cell constants a = 60.5 A, b = 105 A, c = 188 A could be grown. Density measurements of these crystals indicate that the unit cell contains 18 (alpha beta)-units. A detailed packing scheme is proposed that is consistent with the observed pseudo-hexagonal X-ray intensity pattern and with the known size and shape of (alpha beta)3-trimers of C-phycocyanin. Accordingly, disc-like (alpha beta)3-trimers are associated face-to-face and stacked one upon another in rods with a period of 60.5 A, corresponding to the cell dimension a.

Fifth dimension of life and the 4/5 allometric scaling law for human brain.

PubMed

He, Ji-Huan; Zhang, Juan

2004-01-01

Brain cells are not spherical. The basal metabolic rate (B) of a spherical cell scales as B approximately r2, where r is the radius of the cell; that of a brain cell scales as B approximately r(d), where r is the characteristic radius of the cell and d is the fractal dimensionality of its contour. The fractal geometry of the cell leads to a 4/5 allometric scaling law for human brain, uniquely endowing humans with a 5th dimension and successfully explains why the scaling exponent varies during rest and exercise. A striking analogy between Kleiber's 3/4 law and Newton's second law is heuristically illustrated. A physical explanation is given for the 4th dimension of life for three-dimensional organisms and the 5th dimension for human brain.

Hydrodynamic interaction of two particles in confined linear shear flow at finite Reynolds number

NASA Astrophysics Data System (ADS)

Yan, Yiguang; Morris, Jeffrey F.; Koplik, Joel

2007-11-01

We discuss the hydrodynamic interactions of two solid bodies placed in linear shear flow between parallel plane walls in a periodic geometry at finite Reynolds number. The computations are based on the lattice Boltzmann method for particulate flow, validated here by comparison to previous results for a single particle. Most of our results pertain to cylinders in two dimensions but some examples are given for spheres in three dimensions. Either one mobile and one fixed particle or else two mobile particles are studied. The motion of a mobile particle is qualitatively similar in both cases at early times, exhibiting either trajectory reversal or bypass, depending upon the initial vector separation of the pair. At longer times, if a mobile particle does not approach a periodic image of the second, its trajectory tends to a stable limit point on the symmetry axis. The effect of interactions with periodic images is to produce nonconstant asymptotic long-time trajectories. For one free particle interacting with a fixed second particle within the unit cell, the free particle may either move to a fixed point or take up a limit cycle. Pairs of mobile particles starting from symmetric initial conditions are shown to asymptotically reach either fixed points, or mirror image limit cycles within the unit cell, or to bypass one another (and periodic images) indefinitely on a streamwise periodic trajectory. The limit cycle possibility requires finite Reynolds number and arises as a consequence of streamwise periodicity when the system length is sufficiently short.

Crystallization and preliminary X-ray analysis of a low density lipoprotein from human plasma.

PubMed

Prassl, R; Chapman, J M; Nigon, F; Sara, M; Eschenburg, S; Betzel, C; Saxena, A; Laggner, P

1996-11-15

Single crystals of human plasma low density lipoprotein (LDL), the major transport vehicle for cholesterol in blood, have been produced with a view to analysis of the three-dimensional structure by x-ray crystallography. Crystals with dimensions of approximately 200 x 100 x 50 microm have been reproducibly obtained from highly homogeneous LDL particle subspecies, isolated in the density ranges d = 1.0271-1. 0297 g/ml and d = 1.0297-1.0327 g/ml. Electron microscopic imaging of ultrathin-sectioned preparations of the crystals confirmed the existence of a regular, quasihexagonal arrangement of spherical particles of approximately 18 nm in diameter, thereby resembling the dimensions characteristic of LDL after dehydration and fixation. X-ray diffraction with synchrotron radiation under cryogenic conditions revealed the presence of well resolved diffraction spots, to a resolution of about 29 A. The diffraction patterns are indexed in terms of a triclinic lattice with unit cell dimensions of a = 16. 1 nm, b = 39.0 nm, c = 43.9 nm; alpha = 96.2 degrees, beta = 92.1 degrees, gamma = 102 degrees, and with space group P1.

Patient safety culture in obstetrics and gynecology and neonatology units: the nurses' and the midwives' opinion.

PubMed

Ribeliene, Janina; Blazeviciene, Aurelija; Nadisauskiene, Ruta Jolanta; Tameliene, Rasa; Kudreviciene, Ausrele; Nedzelskiene, Irena; Macijauskiene, Jurate

2018-04-22

Patients treated in health care facilities that provide services in the fields of obstetrics, gynecology, and neonatology are especially vulnerable. Large multidisciplinary teams of physicians, multiple invasive and noninvasive diagnostic and therapeutic procedures, and the use of advanced technologies increase the probability of adverse events. The evaluation of knowledge about patient safety culture among nurses and midwives working in such units and the identification of critical areas at a health care institution would reduce the number of adverse events and improve patient safety. The aim of the study was to evaluate the opinion of nurses and midwives working in clinical departments that provide services in the fields of obstetrics, gynecology, and neonatology about patient safety culture and to explore potential predictors for the overall perception of safety. We used the Hospital Survey on Patient Safety Culture (HSOPSC) to evaluate nurses' and midwives' opinion about patient safety issues. The overall response rate in the survey was 100% (n = 233). The analysis of the dimensions of safety on the unit level showed that the respondents' most positive evaluations were in the Organizational Learning - Continuous Improvement (73.2%) and Feedback and Communication about Error (66.8%) dimensions, and the most negative evaluations in the Non-punitive Response to Error (33.5%) and Staffing (44.6%) dimensions. On the hospital level, the evaluation of the safety dimensions ranged between 41.4 and 56.8%. The percentage of positive responses in the outcome dimensions Frequency of Events Reported was 82.4%. We found a significant association between the outcome dimension Frequency of Events Reported and the Hospital Management Support for Patient Safety and Feedback and Communication about Error Dimensions. On the hospital level, the critical domains in health care facilities that provide services in the fields of obstetrics, gynecology, and neonatology were Teamwork Across Hospital Units, and on the unit level - Communication Openness, Teamwork Within Units, Non-punitive Response to Error, and Staffing. The remaining domains were seen as having a potential for improvement.

Phenotypic Dimensions of Spirituality: Implications for Mental Health in China, India, and the United States

PubMed Central

McClintock, Clayton H.; Lau, Elsa; Miller, Lisa

2016-01-01

While the field of empirical study on religion and spirituality in relation to mental health has rapidly expanded over the past decade, little is known about underlying dimensions of spirituality cross-culturally conceived. We aimed to bridge this gap by inductively deriving potential universal dimensions of spirituality through a large-scale, multi-national data collection, and examining the relationships of these dimensions with common psychiatric conditions. Five-thousand five-hundred and twelve participants from China, India, and the United States completed a two-hour online survey consisting of wide-ranging measures of the lived experience of spirituality, as well as clinical assessments. A series of inductive Exploratory Factor Analysis (EFA) and cross-validating Exploratory Structural Equation Modeling (ESEM) were conducted to derive common underlying dimensions of spirituality. Logistic regression analyses were then conducted with each dimension to predict depression, suicidal ideation, generalized anxiety, and substance-related disorders. Preliminary EFA results were consistently supported by ESEM findings. Analyses of 40 spirituality measures revealed five invariant factors across countries which were interpreted as five dimensions of universal spiritual experience, specifically: love, in the fabric of relationships and as a sacred reality; unifying interconnectedness, as a sense of energetic oneness with other beings in the universe; altruism, as a commitment beyond the self with care and service; contemplative practice, such as meditation, prayer, yoga, or qigong; and religious and spiritual reflection and commitment, as a life well-examined. Love, interconnectedness, and altruism were associated with less risk of psychopathology for all countries. Religious and spiritual reflection and commitment and contemplative practice were associated with less risk in India and the United States but associated with greater risk in China. Education was directly associated with dimensions of spiritual awareness in India and China but inversely associated with dimensions in the United States. Findings support the notion that spirituality is a universal phenomenon with potentially universal dimensions. These aspects of spirituality may each offer protective effects against psychiatric symptoms and disorders and suggest new directions for treatment. PMID:27833570

Phenotypic Dimensions of Spirituality: Implications for Mental Health in China, India, and the United States.

PubMed

McClintock, Clayton H; Lau, Elsa; Miller, Lisa

2016-01-01

While the field of empirical study on religion and spirituality in relation to mental health has rapidly expanded over the past decade, little is known about underlying dimensions of spirituality cross-culturally conceived. We aimed to bridge this gap by inductively deriving potential universal dimensions of spirituality through a large-scale, multi-national data collection, and examining the relationships of these dimensions with common psychiatric conditions. Five-thousand five-hundred and twelve participants from China, India, and the United States completed a two-hour online survey consisting of wide-ranging measures of the lived experience of spirituality, as well as clinical assessments. A series of inductive Exploratory Factor Analysis (EFA) and cross-validating Exploratory Structural Equation Modeling (ESEM) were conducted to derive common underlying dimensions of spirituality. Logistic regression analyses were then conducted with each dimension to predict depression, suicidal ideation, generalized anxiety, and substance-related disorders. Preliminary EFA results were consistently supported by ESEM findings. Analyses of 40 spirituality measures revealed five invariant factors across countries which were interpreted as five dimensions of universal spiritual experience, specifically: love, in the fabric of relationships and as a sacred reality; unifying interconnectedness, as a sense of energetic oneness with other beings in the universe; altruism, as a commitment beyond the self with care and service; contemplative practice, such as meditation, prayer, yoga, or qigong; and religious and spiritual reflection and commitment, as a life well-examined. Love, interconnectedness, and altruism were associated with less risk of psychopathology for all countries. Religious and spiritual reflection and commitment and contemplative practice were associated with less risk in India and the United States but associated with greater risk in China. Education was directly associated with dimensions of spiritual awareness in India and China but inversely associated with dimensions in the United States. Findings support the notion that spirituality is a universal phenomenon with potentially universal dimensions. These aspects of spirituality may each offer protective effects against psychiatric symptoms and disorders and suggest new directions for treatment.

Crystallization and preliminary crystallographic analysis of an Enterococcus faecalis repressor protein, CylR2, involved in regulating cytolysin production through quorum-sensing

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

Ni, Shuisong; McAteer, Kathleen; Bussiere, Dirksen E.

2004-06-01

CylR2 is one of the two regulatory proteins associated with the quorum-sensing-dependent synthesis of cytolysin for the common pathogen Enterococcus faecalis. The protein was expressed with a C-terminal 6-histidine tag and purified to homogeneity with a cobalt affinity column followed by another size exclusion column. Both native and SeMet proteins were crystallized. A complete X-ray diffraction data set from the native crystal was collected to 2.3 resolution. The crystal was tetragonal, belonging to space group P41/43, with unit-cell dimensions a=b=66.2 , c=40.9 and a=b=g=90. The asymmetric unit contained two molecules of CylR2.

Mesoporous stilbene-based lanthanide metal organic frameworks: synthesis, photoluminescence and radioluminescence characteristics.

PubMed

Mathis Ii, Stephan R; Golafale, Saki T; Bacsa, John; Steiner, Alexander; Ingram, Conrad W; Doty, F Patrick; Auden, Elizabeth; Hattar, Khalid

2017-01-03

Ultra large pore isostructural metal organic frameworks (MOFs) which exhibit both photoluminescence and scintillation properties, were synthesized from trans-4,4'-stilbenedicarboxylic acid (H 2 L) and trivalent lanthanide (Ln) metal salts under solvothermal conditions (Ln = Er 3+ (1) and Tm 3+ (2)). This new class of mesoporous materials is a non-interpenetrating network that features ultra-large diamond shaped pores of dimensions with approximate cross-sectional dimensions of 28 Å × 12 Å. The fully deprotonated ligand, L, is isolated and rigidified as it serves as the organic linker component of the MOF structure. Its low density unit cells possess asymmetric units with two crystallographically independent Ln 3+ ions in seven coordinate arrangements. A distinct feature of the structure is the bis-bidentate carboxylate groups. They serve as a ligand that coordinates two Ln(iii) ions while each L connects four Ln(iii) ions yielding an exceptionally large diamond-shaped rectangular network. The structure exhibits ligand-based photoluminescence with increased lifetime compared to free stilbene molecules on exposure to UV radiation, and also exhibits strong scintillation characteristics, comprising of both prompt and delayed radioluminescence features, on exposure to ionizing radiation.

Molecular structure of dextran sulphate sodium in aqueous environment

NASA Astrophysics Data System (ADS)

Yu, Miao; Every, Hayley A.; Jiskoot, Wim; Witkamp, Geert-Jan; Buijs, Wim

2018-03-01

Here we propose a 3D-molecular structural model for dextran sulphate sodium (DSS) in a neutral aqueous environment based on the results of a molecular modelling study. The DSS structure is dominated by the stereochemistry of the 1,6-linked α-glucose units and the presence of two sulphate groups on each α-glucose unit. The structure of DSS can be best described as a helix with various patterns of di-sulphate substitution on the glucose rings. The presence of a side chain does not alter the 3D-structure of the linear main chain much, but affects the overall spatial dimension of the polymer. The simulated polymers have a diameter similar to or in some cases even larger than model α-hemolysin nano-pores for macromolecule transport in many biological processes, indicating a size-limited translocation through such pores. All results of the molecular modelling study are in line with previously reported experimental data. This study establishes the three-dimensional structure of DSS and summarizes the spatial dimension of the polymer, serving as the basis for a better understanding on the molecular level of DSS-involved electrostatic interaction processes with biological components like proteins and cell pores.

Interrogating the Escherichia coli cell cycle by cell dimension perturbations

PubMed Central

Zheng, Hai; Ho, Po-Yi; Jiang, Meiling; Tang, Bin; Liu, Weirong; Li, Dengjin; Yu, Xuefeng; Kleckner, Nancy E.; Amir, Ariel; Liu, Chenli

2016-01-01

Bacteria tightly regulate and coordinate the various events in their cell cycles to duplicate themselves accurately and to control their cell sizes. Growth of Escherichia coli, in particular, follows a relation known as Schaechter’s growth law. This law says that the average cell volume scales exponentially with growth rate, with a scaling exponent equal to the time from initiation of a round of DNA replication to the cell division at which the corresponding sister chromosomes segregate. Here, we sought to test the robustness of the growth law to systematic perturbations in cell dimensions achieved by varying the expression levels of mreB and ftsZ. We found that decreasing the mreB level resulted in increased cell width, with little change in cell length, whereas decreasing the ftsZ level resulted in increased cell length. Furthermore, the time from replication termination to cell division increased with the perturbed dimension in both cases. Moreover, the growth law remained valid over a range of growth conditions and dimension perturbations. The growth law can be quantitatively interpreted as a consequence of a tight coupling of cell division to replication initiation. Thus, its robustness to perturbations in cell dimensions strongly supports models in which the timing of replication initiation governs that of cell division, and cell volume is the key phenomenological variable governing the timing of replication initiation. These conclusions are discussed in the context of our recently proposed “adder-per-origin” model, in which cells add a constant volume per origin between initiations and divide a constant time after initiation. PMID:27956612

Interrogating the Escherichia coli cell cycle by cell dimension perturbations.

PubMed

Zheng, Hai; Ho, Po-Yi; Jiang, Meiling; Tang, Bin; Liu, Weirong; Li, Dengjin; Yu, Xuefeng; Kleckner, Nancy E; Amir, Ariel; Liu, Chenli

2016-12-27

Bacteria tightly regulate and coordinate the various events in their cell cycles to duplicate themselves accurately and to control their cell sizes. Growth of Escherichia coli, in particular, follows a relation known as Schaechter's growth law. This law says that the average cell volume scales exponentially with growth rate, with a scaling exponent equal to the time from initiation of a round of DNA replication to the cell division at which the corresponding sister chromosomes segregate. Here, we sought to test the robustness of the growth law to systematic perturbations in cell dimensions achieved by varying the expression levels of mreB and ftsZ We found that decreasing the mreB level resulted in increased cell width, with little change in cell length, whereas decreasing the ftsZ level resulted in increased cell length. Furthermore, the time from replication termination to cell division increased with the perturbed dimension in both cases. Moreover, the growth law remained valid over a range of growth conditions and dimension perturbations. The growth law can be quantitatively interpreted as a consequence of a tight coupling of cell division to replication initiation. Thus, its robustness to perturbations in cell dimensions strongly supports models in which the timing of replication initiation governs that of cell division, and cell volume is the key phenomenological variable governing the timing of replication initiation. These conclusions are discussed in the context of our recently proposed "adder-per-origin" model, in which cells add a constant volume per origin between initiations and divide a constant time after initiation.

Negative refraction imaging of acoustic metamaterial lens in the supersonic range

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

Han, Jianning; Wen, Tingdun; Key Laboratory of Electronic Testing Technology, North University of China, Taiyuan 030051

2014-05-15

Acoustic metamaterials with negative refraction index is the most promising method to overcome the diffraction limit of acoustic imaging to achieve ultrahigh resolution. In this paper, we use localized resonant phononic crystal as the unit cell to construct the acoustic negative refraction lens. Based on the vibration model of the phononic crystal, negative quality parameters of the lens are obtained while excited near the system resonance frequency. Simulation results show that negative refraction of the acoustic lens can be achieved when a sound wave transmiting through the phononic crystal plate. The patterns of the imaging field agree well with thatmore » of the incident wave, while the dispersion is very weak. The unit cell size in the simulation is 0.0005 m and the wavelength of the sound source is 0.02 m, from which we show that acoustic signal can be manipulated through structures with dimensions much smaller than the wavelength of incident wave.« less

Band Gap Optimization Design of Photonic Crystals Material

NASA Astrophysics Data System (ADS)

Yu, Y.; Yu, B.; Gao, X.

2017-12-01

The photonic crystal has a fundamental characteristic - photonic band gap, which can prevent light to spread in the crystals. This paper studies the width variation of band gaps of two-dimension square lattice photonic crystals by changing the geometrical shape of the unit cells’ inner medium column. Using the finite element method, we conduct numerical experiments on MATLAB 2012a and COMSOL 3.5. By shortening the radius in vertical axis and rotating the medium column, we design a new unit cell, with a 0.3*3.85e-7 vertical radius and a 15 degree deviation to the horizontal axis. The new cell has a gap 1.51 percent wider than the circle medium structure in TE gap and creates a 0.0124 wide TM gap. Besides, the experiment shows the first TM gap is partially overlapped by the second TE gap in gap pictures. This is helpful to format the absolute photonic band gaps and provides favorable theoretical basis for designing photonic communication material.

The Crystal and Molecular Structure of an Asymmetric Diacetylene Monomer, 6-(2-methyl-4-nitroanilino)-2,4-hexadiyne-1-ol

NASA Technical Reports Server (NTRS)

Vlasse, Marcus; Paley, Mark S.

1993-01-01

The crystal and molecular structure of an asymmetric diacetylene monomer has been determined from x-ray diffraction data. The crystals, obtained from an acetone/pentane solution, are orthorhombic, Fdd2 with Z = 16 in a unit cell having dimensions of a = 42.815(6) A, b = 22.224(5) A, c = 4.996(l) A. The structure was solved by direct methods and refined by least- squares techniques to an R(sub F) of 6.4% for 988 reflections and 171 variables. The diacetylene chains are disposed in the unit cell in a complex manner in order to satisfy the hydrogen- bonding, crystal packing, and symmetry requirements of the system. The solid state polymerization mechanism is discussed with respect to the geometric disposition of the diacetylene chains. These chains are far apart and incorrectly oriented with respect to each other to permit polymerization in the crystal by means of 1,4-addition, consistent with the Baughman mechanistic model.

Unit cell parameters of wurtzite InP nanowires determined by x-ray diffraction.

PubMed

Kriegner, D; Wintersberger, E; Kawaguchi, K; Wallentin, J; Borgström, M T; Stangl, J

2011-10-21

High resolution x-ray diffraction is used to study the structural properties of the wurtzite polytype of InP nanowires. Wurtzite InP nanowires are grown by metal-organic vapor phase epitaxy using S-doping. From the evaluation of the Bragg peak position we determine the lattice parameters of the wurtzite InP nanowires. The unit cell dimensions are found to differ from the ones expected from geometric conversion of the cubic bulk InP lattice constant. The atomic distances along the c direction are increased whereas the atomic spacing in the a direction is reduced in comparison to the corresponding distances in the zinc-blende phase. Using core/shell nanowires with a thin core and thick nominally intrinsic shells we are able to determine the lattice parameters of wurtzite InP with a negligible influence of the S-doping due to the much larger volume in the shell. The determined material properties will enable the ab initio calculation of electronic and optical properties of wurtzite InP nanowires.

Ethical Dimensions of Quality of Life in Aging: Autonomy vs. Collectivism in the United States and Canada.

ERIC Educational Resources Information Center

Clark, Phillip G.

1991-01-01

Compares and contrasts value orientations of personal independence and collectivism in the United States and Canada and examines their relationship to concept of quality of life in aging. Explores implications of the analysis for expanding understanding of importance of value dimensions in comparative gerontology, and suggests ways of integrating…

Motor unit firing rates and synchronisation affect the fractal dimension of simulated surface electromyogram during isometric/isotonic contraction of vastus lateralis muscle.

PubMed

Mesin, Luca; Dardanello, Davide; Rainoldi, Alberto; Boccia, Gennaro

2016-12-01

During fatiguing contractions, many adjustments in motor units behaviour occur: decrease in muscle fibre conduction velocity; increase in motor units synchronisation; modulation of motor units firing rate; increase in variability of motor units inter-spike interval. We simulated the influence of all these adjustments on synthetic EMG signals in isometric/isotonic conditions. The fractal dimension of the EMG signal was found mainly influenced by motor units firing behaviour, being affected by both firing rate and synchronisation level, and least affected by muscle fibre conduction velocity. None of the calculated EMG indices was able to discriminate between firing rate and motor units synchronisation. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Psychosocial factors and mental work load: a reality perceived by nurses in intensive care units1

PubMed Central

Ceballos-Vásquez, Paula; Rolo-González, Gladys; Hérnandez-Fernaud, Estefanía; Díaz-Cabrera, Dolores; Paravic-Klijn, Tatiana; Burgos-Moreno, Mónica

2015-01-01

OBJECTIVE: To analyse the perception of psychosocial factors and mental workload of nurses who work in intensive care units. It is hypothesised that nurses in these units could perceive psychosocial risks, manifesting in a high mental work load. The psychosocial dimension related to the position's cognitive demands is hypothesised to mostly explain mental work load. METHOD: Quantitative study, with a descriptive, cross-sectional, and comparative design. A total of 91% of the intensive care unit populations of three Chilean hospitals was surveyed, corresponding to 111 nurses. The instruments utilised included (A) a biosociodemographic history questionnaire; (b) the SUSESO-ISTAS 21 questionnaire; and (c) the Mental Work Load Subjective Scale (ESCAM, in Spanish). RESULTS: In total, 64% and 57% of participants perceived high levels of exposure to the psychosocial risks Psychosocial demands and Double shift, respectively. In addition, a medium-high level of overall mental load was observed. Positive and significant correlations between some of the SUSESO-ISTAS 21 and ESCAM dimensions were obtained. Using a regression analysis, it was determined that three dimensions of the psychosocial risk questionnaire helped to explain 38% of the overall mental load. CONCLUSION: Intensive care unit nurses felt that inadequate psychosocial factors and mental work overload existed in several of the tested dimensions. PMID:26039303

Psychosocial factors and mental work load: a reality perceived by nurses in intensive care units.

PubMed

Ceballos-Vásquez, Paula; Rolo-González, Gladys; Hérnandez-Fernaud, Estefanía; Díaz-Cabrera, Dolores; Paravic-Klijn, Tatiana; Burgos-Moreno, Mónica

2015-01-01

To analyse the perception of psychosocial factors and mental workload of nurses who work in intensive care units. It is hypothesised that nurses in these units could perceive psychosocial risks, manifesting in a high mental work load. The psychosocial dimension related to the position's cognitive demands is hypothesised to mostly explain mental work load. Quantitative study, with a descriptive, cross-sectional, and comparative design. A total of 91% of the intensive care unit populations of three Chilean hospitals was surveyed, corresponding to 111 nurses. The instruments utilised included (A) a biosociodemographic history questionnaire; (b) the SUSESO-ISTAS 21 questionnaire; and (c) the Mental Work Load Subjective Scale (ESCAM, in Spanish). In total, 64% and 57% of participants perceived high levels of exposure to the psychosocial risks Psychosocial demands and Double shift, respectively. In addition, a medium-high level of overall mental load was observed. Positive and significant correlations between some of the SUSESO-ISTAS 21 and ESCAM dimensions were obtained. Using a regression analysis, it was determined that three dimensions of the psychosocial risk questionnaire helped to explain 38% of the overall mental load. Intensive care unit nurses felt that inadequate psychosocial factors and mental work overload existed in several of the tested dimensions.

Two-dimensional frequency scanning from a metasurface-based Fabry–Pérot resonant cavity

NASA Astrophysics Data System (ADS)

Yang, Pei; Yang, Rui

2018-06-01

A spatial angular filtering metasurface is introduced into a Fabry–Pérot (FP) resonant cavity design for the frequency scanning performance in this paper. More specifically, asymmetrical unit cells printed on the metasurface enable the radiation energy to move in different directions as the frequency changes, and the released emissions, meanwhile, are split into dual-beams from the initial pencil beam. We continue to implement a patch array to provide excitation with the aim of achieving scanned beams in another dimension, and the proposed design ultimately demonstrates a two-dimensional dual-beam scanning performance with 42° and 9° scanning angles respectively in two dimensions of the coordinate system over a frequency range from 10.50 GHz–11.25 GHz. The proposed technique, by integrating a spatial angular filtering metasurface with a patch array feed to generate steerable beams, should offer an efficient way to fulfill FP resonant cavities with reconfigurable radiation.

Changes in patient safety culture after restructuring of intensive care units: Two cross-sectional studies.

PubMed

Vifladt, Anne; Simonsen, Bjoerg O; Lydersen, Stian; Farup, Per G

2016-02-01

Compare changes in registered nurses' perception of the patient safety culture in restructured and not restructured intensive care units during a four-year period. Two cross-sectional surveys were performed, in 2008/2009 (time 1) and 2012/2013 (time 2). During a period of 0-3 years after time 1, three of six hospitals merged their general and medical intensive care units (restructured). The other hospitals maintained their structure of the intensive care units (not restructured). Intensive care units in hospitals at one Norwegian hospital trust. The safety culture was measured with Hospital Survey on Patient Safety Culture. At times 1 and 2, 217/302 (72%) and 145/289 (50%) registered nurses participated. Restructuring was negatively associated with change in the safety culture, in particular, the dimensions of the safety culture within the unit level. The dimensions most vulnerable for restructuring were manager expectations and actions promoting safety, teamwork within hospital units and staffing. In this study, the restructuring of intensive care units was associated with a negative impact on the safety culture. When restructuring, the management should be particularly aware of changes in the safety culture dimensions manager expectations and actions promoting safety, teamwork within hospital units and staffing. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Standard Sizes for Rough-Dimension Exports to Europe and Japan

Treesearch

Philip A. Araman

1987-01-01

In this article, European and Japanese standard-sized rough dimension products are described, and their apparent sizes are listed. One set of proposed standard sizes of rough dimension that could be manufactured in the United States for these markets is presented. Also, the benefits of the production and sale of standard sizes of export rough dimension are highlighted...

How Does Patient Safety Culture in the Surgical Departments Compare to the Rest of the County Hospitals in Xiaogan City of China?

PubMed Central

Wang, Manli; Tao, Hongbing

2017-01-01

Objectives: Patient safety culture affects patient safety and the performance of hospitals. The Hospital Survey on Patient Safety Culture (HSOPSC) is generally used to assess the safety culture in hospitals and unit levels. However, only a few studies in China have measured surgical settings compared with other units in county hospitals using the HSOPSC. This study aims to assess the strengths and weaknesses of surgical departments compared with all other departments in county hospitals in China with HSOPSC. Design: This research is a cross-sectional study. Methods: In 2015, a Chinese translation of HSOPSC was administered to 1379 staff from sampled departments from 19 county hospitals in Xiaogan City (Hubei Province, China) using a simple random and cluster sampling method. Outcome Measures: The HSOPSC was completed by 1379 participants. The percent positive ratings (PPRs) of 12 dimensions (i.e., teamwork within units, organizational learning and continuous improvement, staffing, non-punitive response to errors, supervisor/ manager expectations and actions promoting patient safety, feedback and communication about errors, communication openness, hospital handoffs and transitions, teamwork across hospital units, hospital management support for patient safety, overall perception of safety, as well as frequency of events reported) and the positive proportion of outcome variables (patient safety grade and number of events reported) between surgical departments and other departments were compared with t-tests and X2 tests, respectively. A multiple regression analysis was conducted, with the outcome dimensions serving as dependent variables and basic characteristics and other dimensions serving as independent variables. Similarly, ordinal logistic regression was used to explore the influencing factors of two categorical outcomes. Results: A total of 56.49% of respondents were from surgical departments. The PPRs for “teamwork within units” and “organizational learning and continuous improvement” were ≥75%, which denoted strengths, and the PPRs for “staffing” and “non-punitive response to errors” were ≤50%, which denoted weaknesses in surgical units and other units. Three dimensions for surgical departments were weaker than those for other departments (p < 0.05). The staff from surgical units reported more events compared with the other units, but only a few respondents in surgical settings evaluated patient safety grade as good/excellent. Four dimensions influenced patient safety grade, and three dimensions influenced event reporting in surgical units. Conclusions: Strategies including recruiting workers, using the reporting system, and building a non-punitive culture should be adopted in the surgical units of county hospitals in China to improve safety culture. Supervisors should also prioritise patient safety. PMID:28954427

Polymorphism of Alprazolam (Xanax): a review of its crystalline phases and identification, crystallographic characterization, and crystal structure of a new polymorph (form III).

PubMed

de Armas, Héctor Novoa; Peeters, Oswald M; Van den Mooter, Guy; Blaton, Norbert

2007-05-01

A new polymorphic form of Alprazolam (Xanax), 8-chloro-1-methyl-6-phenyl-4H-[1,2,4]triazolo-[4,3-alpha][1,4]benzodiazepine, C(17)H(13)ClN(4), has been investigated by means of X-ray powder diffraction (XRPD), single crystal X-ray diffraction, and differential scanning calorimetry (DSC). This polymorphic form (form III) was obtained during DSC experiments after the exothermic recrystallization of the melt of form I. The crystal unit cell dimensions for form III were determined from diffractometer methods. The monoclinic unit cell found for this polymorph using XRPD after indexing the powder diffractogram was confirmed by the cell parameters obtained from single crystal X-ray diffractometry on a crystal isolated from the DSC pans. The single crystal unit cell parameters are: a = 28.929(9), b = 13.844(8), c = 7.361(3) angstroms, beta = 92.82(3) degrees , V = 2944(2) angstroms(3), Z = 8, space group P2(1) (No.4), Dx = 1.393 Mg/m(3). The structure obtained from single crystal X-ray diffraction was used as initial model for Rietveld refinement on the powder diffraction data of form III. The temperature phase transformations of alprazolam were also studied using high temperature XRPD. A review of the different phases available in the Powder Diffraction File (PDF) database for this drug is described bringing some clarification and corrections. (c) 2007 Wiley-Liss, Inc. and the American Pharmacists Association.

Thermodynamic Mixing Behavior Of F-OH Apatite Crystalline Solutions

NASA Astrophysics Data System (ADS)

Hovis, G. L.

2011-12-01

It is important to establish a thermodynamic data base for accessory minerals and mineral series that are useful in determining fluid composition during petrologic processes. As a starting point for apatite-system thermodynamics, Hovis and Harlov (2010, American Mineralogist 95, 946-952) reported enthalpies of mixing for a F-Cl apatite series. Harlov synthesized all such crystalline solutions at the GFZ-Potsdam using a slow-cooled molten-flux method. In order to expand thermodynamic characterization of the F-Cl-OH apatite system, a new study has been initiated along the F-OH apatite binary. Synthesis of this new series made use of National Institute of Standards and Technology (NIST) 2910a hydroxylapatite, a standard reference material made at NIST "by solution reaction of calcium hydroxide with phosphoric acid." Synthesis efforts at Lafayette College have been successful in producing fluorapatite through ion exchange between hydroxylapatite 2910a and fluorite. In these experiments, a thin layer of hydroxylapatite powder was placed on a polished CaF2 disc (obtained from a supplier of high-purity crystals for spectroscopy), pressed firmly against the disc, then annealed at 750 °C (1 bar) for three days. Longer annealing times did not produce further change in unit-cell dimensions of the resulting fluorapatite, but it is uncertain at this time whether this procedure produces a pure-F end member (chemical analyses to be performed in the near future). It is clear from the unit-cell dimensions, however, that the newly synthesized apatite contains a high percentage of fluorine, probably greater than 90 mol % F. Intermediate compositions for a F-OH apatite series were made by combining 2910a hydroxylapatite powder with the newly synthesized fluorapatite in various proportions, then conducting chemical homogenization experiments at 750 °C on each mixture. X-ray powder diffraction data indicated that these experiments were successful in producing chemically homogeneous intermediate series members, as doubled peaks merged into single diffraction maxima, the latter changing position systematically with bulk composition. All of the resulting F-OH apatite series members have hexagonal symmetry. The "a" unit-cell dimension behaves linearly with composition, and "c" is nearly constant across the series. Unit-cell volume also is linear with F:OH ratio, thus behaving in a thermodynamically ideal manner. Solution calorimetric experiments have been conducted in 20.0 wt % HCl at 50 °C on all series members. Enthalpies of F-OH mixing are nonexistent at F-rich compositions but have small negative values toward the hydroxylapatite end member. There is no enthalpy barrier, therefore, to complete F-OH mixing across the series, indicated as well by the ease of chemical homogenization for intermediate F:OH series members. In addition to the synthetic specimens described above, natural samples of hydroxylapatite, fluorapatite, and chlorapatite have been obtained for study from the U.S. National Museum of Natural History, as well as the American Museum of Natural History (our sincere appreciation to both museums for providing samples). Solution calorimetric results for these samples will be compared with data for the synthetic OH, F, and Cl apatite analogs noted above.

Symptom changes in five dimensions of the Positive and Negative Syndrome Scale in refractory psychosis.

PubMed

Woodward, Todd S; Jung, Kwanghee; Smith, Geoffrey N; Hwang, Heungsun; Barr, Alasdair M; Procyshyn, Ric M; Flynn, Sean W; van der Gaag, Mark; Honer, William G

2014-12-01

Refractory psychosis units currently have little information regarding which symptoms profiles should be expected to respond to treatment. In the current study, we provide this information using structural equation modeling of Positive and Negative Syndrome Scale (PANSS) ratings at admission and discharge on a sample of 610 patients admitted to a treatment refractory psychosis program at a Canadian tertiary care unit between 1990 and 2011. The hypothesized five-dimensional structure of the PANSS fit the data well at both admission and discharge, and the latent variable scores are reported as a function of symptom dimension and diagnostic category. The results suggest that, overall, positive symptoms (POS) responded to treatment better than all other symptoms dimensions, but for the schizoaffective and bipolar groups, greater response on POS was observed relative to the schizophrenia and major depression groups. The major depression group showed the most improvement on negative symptoms and emotional distress, and the bipolar group showed the most improvement on disorganization. Schizophrenia was distinct from schizoaffective disorder in showing reduced treatment response on all symptom dimensions. These results can assist refractory psychosis units by providing information on how PANSS symptom dimensions respond to treatment and how this depends on diagnostic category.

Foam metal metamaterial panel for mechanical waves isolation

NASA Astrophysics Data System (ADS)

Hua, Lei; Sun, Hongwei; Gu, Jinliang

2016-04-01

This paper presents modeling, analysis techniques and experiment of foam metal metamaterial panel for Broadband Vibration Absorption. For a unit cell of an infinite foam metal metamaterial panel, governing equations are derived using the extended Hamilton principle. The concepts of negative effective mass and stiffness and how the spring-mass-damper subsystems create a stopband are explained in detail. Numerical simulations reveal that the actual working mechanism of the proposed metamaterial panel is based on the concept of conventional mechanical vibration absorbers. It uses the incoming elastic wave in the panel to resonate the integrated membrane-mass-damper absorbers to vibrate in their optical mode at frequencies close to but above their local resonance frequencies to create shear forces and bending moments to straighten the panel and stop the wave propagation. Moreover, a two-dimension acoustic foam metal metamaterial panel consisting of lumped mass and elastic membrane is proposed in the lab. We do experiments on the model and The results validate the concept and show that, for two-dimension acoustic foam metal metamaterial panel do exist two vibration modes. For the wave absorption, the mass of each cell should be considered in the design. With appropriate design calculations, the proposed two-dimension acoustic foam metal metamaterial panel can be used for absorption of low-frequency waves and hence expensive micro-manufacturing techniques are not needed for design and manufacturing of such foam metal metamaterial panel for low-frequency waves absorption/isolation.

Ternary and quaternary oxides of Bi, Sr and Cu

NASA Technical Reports Server (NTRS)

Casais, M. T.; Millan, P.; Rasines, I.; Campa, J. A.

1991-01-01

Before the discovery of superconductivity in an oxide of Bi, Sr, and Cu, the system Bi-Sr-Cu-O had not been studied, although several solid phases had been identified in the two-component regions of the ternary system Bi2O3-Si-O-CuO. The oxides Sr2CuO3, SrCu2O2, SrCuO2, and Bi2CuO4 were then well known and characterized, and the phase diagram of the binary system Bi2O3-SrO had been established in the temperature range 620 to 1000 C. Besides nine solutions of compositions Bi(2-2x) Sr(x) O(3-2x) and different symmetries, this diagram includes three definite compounds of stoichiometries Bi(2)BrO4. Bi2Sr2O5, and Bi2Sr3O6 (x - 0.50, 0.67 and 0.75 respectively), only the second of which with known unit-cell of orthorhombic symmetry, dimensions (A) a = 14.293(2), b = 7.651(2), c = 6.172(1), and z = 4. The first superconducting oxide in the system Bi-Sr-Cu-O was initially formulated as Bi2Sr2Cu2O(7+x), with an orthorhombic unit-cell of parameters (A) a = 5.32, b = 26.6, c = 48.8. In a preliminary study the same oxide was formulated with half the copper content, Bi(2)Sr(2)CuO(6+x), and index its reflections assuming an orthorhombic unit-cell of dimensions (A) a = 5.390(2), b = 26.973(8), c = 24.69(4). Subsequent studies by diffraction techniques have confirmed the composition 2:2:1. A new family of oxygen-deficient perovskites, was characterized, after identifying by x ray diffraction the phases present in the products of thermal treatments of about 150 mixtures of analytical grade Bi2O3, Sr(OH)2-8H2O and CuO at different molar ratios. X ray diffraction data are presented for some other oxides of Bi and Sr, as well as for various quaternary oxides, among them an oxide of Bi, Sr, and Cu.

X-ray diffraction and infrared spectroscopy studies of Ba(Fe1/2Nb1/2)O3-(Na1/2Bi1/2)TiO3 ceramics

NASA Astrophysics Data System (ADS)

Chandra, K. P.; Yadav, Anjana; Prasad, K.

2018-05-01

Ceramics (1-x)Ba(Fe1/2Nb1/2)O3-x(Na1/2Bi1/2)TiO3; 0≤x≤1.0 were prepared by conventional ceramic synthesis technique. Rietveld refinements of X-ray diffraction data of these ceramics were carried out using FullProf software and determined their crystal symmetry, space group and unit cell dimensions. Rietveld refinement revealed that Ba(Fe1/2Nb1/2)O3 has cubic structure with space group Pm 3 ¯ m and Na1/2Bi1/2)TiO3 has rhombohedral structure with space group R3c. Addition of (Na1/2Bi1/2)TiO3 to Ba(Fe1/2Nb1/2)O3 resulted in the change of unit cell structure from cubic to tetragonal (P4/mmm) for x = 0.75 and the X-Ray diffraction peaks slightly shift towards higher Bragg's angle, suggesting slight decrease in unit cell volume. SEM studies were carried out in order to access the quality of the prepared ceramics which showed a change in grain shapes with the increase of (Na1/2Bi1/2)TiO3 content. FTIR spectra confirmed the formation of perovskite type solid solutions.

A Review of the Literature on the Multiple Dimensions of Chronic Pain in Adults with Sickle Cell Disease

PubMed Central

Taylor, Lou Ella V.; Stotts, Nancy A.; Humphreys, Janice; Treadwell, Marsha J.; Miaskowski, Christine

2010-01-01

Sickle cell disease (SCD) is a major healthcare and societal problem that affects millions of people worldwide. In Nigeria, 45,000 to 90,000 babies are born each year with SCD. In the United States, SCD is the most common genetic disorder, affecting more than 80,000 people, the majority of whom are African American. Sickle cell pain is the hallmark feature of SCD. Most of the research on pain from SCD has focused on children with acute pain associated with sickle cell crisis. Consequently, very little is known about the occurrence and characteristics of chronic pain, especially in adults with SCD. Individuals with SCD who experience chronic pain are often underserved and their pain is under-treated. This under-treatment may result in millions of dollars per year spent on emergency room visits, hospitalizations, and lost work productivity. The primary purpose of this literature review was to summarize the findings from studies that evaluated the characteristics of chronic pain in adults with SCD. Each of the studies included in this review was evaluated to determine if it provided data on the following multidimensional characteristics of chronic pain: occurrence, number of pain episodes, duration, pattern, quality, location, intensity, aggravating factors, relieving factors, and impact of pain on function. A secondary purpose was to identify gaps in knowledge and directions for future research on the multiple dimensions of chronic pain in adults with SCD. PMID:20656451

Electromagnetically induced transparency metamaterial based on spoof localized surface plasmons at terahertz frequencies

PubMed Central

Liao, Zhen; Liu, Shuo; Ma, Hui Feng; Li, Chun; Jin, Biaobing; Cui, Tie Jun

2016-01-01

We numerically and experimentally demonstrate a plasmonic metamaterial whose unit cell is composed of an ultrathin metallic disk and four ultrathin metallic spiral arms at terahertz frequencies, which supports both spoof electric and magnetic localized surface plasmon (LSP) resonances. We show that the resonant wavelength is much larger than the size of the unit particle, and further find that the resonant wavelength is very sensitive to the particle’s geometrical dimensions and arrangements. It is clearly illustrated that the magnetic LSP resonance exhibits strong dependence to the incidence angle of terahertz wave, which enables the design of metamaterials to achieve an electromagnetically induced transparency effect in the terahertz frequencies. This work opens up the possibility to apply for the surface plasmons in functional devices in the terahertz band. PMID:27277417

Crystallization and preliminary crystallographic study of 3 alpha, 20 beta-hydroxysteroid dehydrogenase from Streptomyces hydrogenans.

PubMed

Fitzgerald, P M; Duax, W L; Punzi, J S; Orr, J C

1984-05-15

3 alpha, 20 beta-Hydroxysteroid dehydrogenase, an NADH-dependent oxidoreductase isolated from Streptomyces hydrogenans , is a tetramer containing four subunits each of Mr 25,000. The enzyme has been crystallized by the vapor diffusion technique using either phosphate or borate buffered ammonium sulfate (pH between 6.0 and 8.7) as the precipitant. The crystals are hexagonal bipyramids ; they have the symmetry of space group P6(4)22 (or P6(2)22), with unit cell dimensions a = 127.3 A, c = 112.2 A. Volume and density considerations imply that the crystallographic asymmetric unit contains two monomers, and therefore that the tetramer possesses a 2-fold axis of symmetry that is coincident with a crystallographic 2-fold symmetry element.

Visualization of drug-nucleic acid interactions at atomic resolution v. structure of two aminoacridine/dinucleoside monophosphate crystalline complexes, proflavine: 5-iodocytidylyl(3'-5') guanosine and acridine orange: 5-iodocytidylyl(3'-5') guanosine

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

Reddy, B.S.; Seshadri, T.P.; Sakore, T.D.

1979-01-01

Acridine orange and proflavine form complexes with the dinucleoside monophosphate, 5-iodocytidylyl(3'-5') guanosine (iodoCpG). The acridine orange-iodoCpG crystals are monoclinic, space group P2/sub 1/, with unit cell dimensions a = 14.36 A, b = 19.64 A, c = 20.67 A, ..beta.. = 102.5. The proflavine-iodoCpG crystals are monoclinic, space group C2, with unit cell dimensions a = 32.14 A, b = 22.23 A, c = 18.42 A, ..beta.. = 123.3. Both structures have been solved to atomic resolution by Patterson and Fourier methods, and refined by full matrix least squares. Acridine orange forms an intercalative structure with iodoCpG but the acridinemore » nucleus lies asymmetrically in the intercalation site. This asymmetric intercalation is accompanied by a sliding of base-pairs upon the acridine nucleus. Base-pairs above and below the drug are separated by about 6.8 A and are twisted about 10/sup 0/. Proflavine demonstrates symmetric intercalation with iodoCpG. Hydrogen bonds connect amino- groups on proflavine with phosphate oxygen atoms on the dinucleotide. Base-pairs above and below the intercalative proflavine molecule are twisted about 36/sup 0/. The altered magnitude of this angular twist reflects the sugar puckering pattern that is observed. We propose a proflavine-DNA and an acridine orange-DNA binding model. We will describe these models in detail in this paper.« less

Phytotoxicity, structural and computational analysis of 2-methyl-1,5-diarylpentadienones

NASA Astrophysics Data System (ADS)

Din, Zia Ud; Rodrigues-Filho, Edson; de Cassia Pereira, Viviane; Gualtieri, Sonia Cristina Juliano; Deflon, Victor Marcelo; da Silva Maia, Pedro Ivo; Kuznetsov, Aleksey E.

2017-08-01

In our studies aimed to produce new chemicals used in weed control, 2-methyl-1,5-diarylpentadienones were synthesized by the reaction of p-methoxybenzaldehyde, p-nitrobenzaldehyde and p-N,N-dimethylbenzaldehyde, respectively, with 2-butanone, resulting in four model compounds. The phytotoxicity of these compounds against wheat coleoptiles and Sesame seedling was observed at μM concentrations, indicating good potential for their usage in weed management in the field. Spectroscopic and computational studies were performed in order to gain understanding on their mechanisms of action and to clarify some structural complexities due existence of conformers and substituent effects. These compounds probably act as hydroxyphenylpyruvate dioxygenase inhibitors. The tested compounds were characterized by spectroscopic and single crystal X-ray diffraction analyses. Solid crystalline state of the compound A (2-Methyl-1-(p-methophyphenyl)-5-(phenyl)-diarylpentadienone) is observed in the monoclinic space group P21/c with unit cell dimensions a = 14.3366(4) Å, b = 11.3788(4) Å, c = 9.6319(3) Å, β = 96.596, V = 1560.88(9) Å3 and Z = 4. Compound C (2-Methyl-1-(p-methophyphenyl)-5-(p-nitrophenyl)-diarylpentadienone) crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 17.8276(9) Å, b = 7.3627(4) Å, c = 12.9740(6) Å, β = 107.6230(10), V = 1623.04(14) Å3 and Z = 4. LC-UV-MS analysis furnished important data helpful for their characterization. The spectroscopic data and computational (DFT) analysis revealed the fact that each of the compounds A-D occurs in solution as four conformers.

Comparing two safety culture surveys: safety attitudes questionnaire and hospital survey on patient safety.

PubMed

Etchegaray, Jason M; Thomas, Eric J

2012-06-01

To examine the reliability and predictive validity of two patient safety culture surveys-Safety Attitudes Questionnaire (SAQ) and Hospital Survey on Patient Safety Culture (HSOPS)-when administered to the same participants. Also to determine the ability to convert HSOPS scores to SAQ scores. Employees working in intensive care units in 12 hospitals within a large hospital system in the southern United States were invited to anonymously complete both safety culture surveys electronically. All safety culture dimensions from both surveys (with the exception of HSOPS's Staffing) had adequate levels of reliability. Three of HSOPS's outcomes-frequency of event reporting, overall perceptions of patient safety, and overall patient safety grade-were significantly correlated with SAQ and HSOPS dimensions of culture at the individual level, with correlations ranging from r=0.41 to 0.65 for the SAQ dimensions and from r=0.22 to 0.72 for the HSOPS dimensions. Neither the SAQ dimensions nor the HSOPS dimensions predicted the fourth HSOPS outcome-number of events reported within the last 12 months. Regression analyses indicated that HSOPS safety culture dimensions were the best predictors of frequency of event reporting and overall perceptions of patient safety while SAQ and HSOPS dimensions both predicted patient safety grade. Unit-level analyses were not conducted because indices did not indicate that aggregation was appropriate. Scores were converted between the surveys, although much variance remained unexplained. Given that the SAQ and HSOPS had similar reliability and predictive validity, investigators and quality and safety leaders should consider survey length, content, sensitivity to change and the ability to benchmark when selecting a patient safety culture survey.

Random-Walk Model of Diffusion in Three Dimensions in Brain Extracellular Space: Comparison with Microfiberoptic Photobleaching Measurements

PubMed Central

Jin, Songwan; Zador, Zsolt; Verkman, A. S.

2008-01-01

Diffusion through the extracellular space (ECS) in brain is important in drug delivery, intercellular communication, and extracellular ionic buffering. The ECS comprises ∼20% of brain parenchymal volume and contains cell-cell gaps ∼50 nm. We developed a random-walk model to simulate macromolecule diffusion in brain ECS in three dimensions using realistic ECS dimensions. Model inputs included ECS volume fraction (α), cell size, cell-cell gap geometry, intercellular lake (expanded regions of brain ECS) dimensions, and molecular size of the diffusing solute. Model output was relative solute diffusion in water versus brain ECS (Do/D). Experimental Do/D for comparison with model predictions was measured using a microfiberoptic fluorescence photobleaching method involving stereotaxic insertion of a micron-size optical fiber into mouse brain. Do/D for the small solute calcein in different regions of brain was in the range 3.0–4.1, and increased with brain cell swelling after water intoxication. Do/D also increased with increasing size of the diffusing solute, particularly in deep brain nuclei. Simulations of measured Do/D using realistic α, cell size and cell-cell gap required the presence of intercellular lakes at multicell contact points, and the contact length of cell-cell gaps to be least 50-fold smaller than cell size. The model accurately predicted Do/D for different solute sizes. Also, the modeling showed unanticipated effects on Do/D of changing ECS and cell dimensions that implicated solute trapping by lakes. Our model establishes the geometric constraints to account quantitatively for the relatively modest slowing of solute and macromolecule diffusion in brain ECS. PMID:18469079

Random-walk model of diffusion in three dimensions in brain extracellular space: comparison with microfiberoptic photobleaching measurements.

PubMed

Jin, Songwan; Zador, Zsolt; Verkman, A S

2008-08-01

Diffusion through the extracellular space (ECS) in brain is important in drug delivery, intercellular communication, and extracellular ionic buffering. The ECS comprises approximately 20% of brain parenchymal volume and contains cell-cell gaps approximately 50 nm. We developed a random-walk model to simulate macromolecule diffusion in brain ECS in three dimensions using realistic ECS dimensions. Model inputs included ECS volume fraction (alpha), cell size, cell-cell gap geometry, intercellular lake (expanded regions of brain ECS) dimensions, and molecular size of the diffusing solute. Model output was relative solute diffusion in water versus brain ECS (D(o)/D). Experimental D(o)/D for comparison with model predictions was measured using a microfiberoptic fluorescence photobleaching method involving stereotaxic insertion of a micron-size optical fiber into mouse brain. D(o)/D for the small solute calcein in different regions of brain was in the range 3.0-4.1, and increased with brain cell swelling after water intoxication. D(o)/D also increased with increasing size of the diffusing solute, particularly in deep brain nuclei. Simulations of measured D(o)/D using realistic alpha, cell size and cell-cell gap required the presence of intercellular lakes at multicell contact points, and the contact length of cell-cell gaps to be least 50-fold smaller than cell size. The model accurately predicted D(o)/D for different solute sizes. Also, the modeling showed unanticipated effects on D(o)/D of changing ECS and cell dimensions that implicated solute trapping by lakes. Our model establishes the geometric constraints to account quantitatively for the relatively modest slowing of solute and macromolecule diffusion in brain ECS.

Units for quantities of dimension one

NASA Astrophysics Data System (ADS)

Dybkaer, René

2004-02-01

All quantities of dimension one are said to have the SI coherent derived unit "one" with the symbol '1'. (Single quotation marks are used here sometimes to indicate a quote, name, term or symbol; double quotation marks flag a concept when necessary.) Conventionally, the term and symbol may not be combined with the SI prefixes (except for the special terms and symbols for one and 1: radian, rad, and steradian, sr). This restriction is understandable, but leads to correct yet impractical alternatives and ISO deprecated symbols such as ppm or in some cases redundant combinations of units, such as mg/kg. "Number of entities" is dimensionally independent of the current base quantities and should take its rightful place among them. The corresponding base unit is "one". A working definition is given. Other quantities of dimension one are derived as fraction, ratio, efficiency, relative quantity, relative increment or characteristic number and may also use the unit "one", whether considered to be base or derived. The special term 'uno' and symbol 'u' in either case are proposed, allowing combination with SI prefixes.

Challenges of small-pixel infrared detectors: a review.

PubMed

Rogalski, A; Martyniuk, P; Kopytko, M

2016-04-01

In the last two decades, several new concepts for improving the performance of infrared detectors have been proposed. These new concepts particularly address the drive towards the so-called high operating temperature focal plane arrays (FPAs), aiming to increase detector operating temperatures, and as a consequence reduce the cost of infrared systems. In imaging systems with the above megapixel formats, pixel dimension plays a crucial role in determining critical system attributes such as system size, weight and power consumption (SWaP). The advent of smaller pixels has also resulted in the superior spatial and temperature resolution of these systems. Optimum pixel dimensions are limited by diffraction effects from the aperture, and are in turn wavelength-dependent. In this paper, the key challenges in realizing optimum pixel dimensions in FPA design including dark current, pixel hybridization, pixel delineation, and unit cell readout capacity are outlined to achieve a sufficiently adequate modulation transfer function for the ultra-small pitches involved. Both photon and thermal detectors have been considered. Concerning infrared photon detectors, the trade-offs between two types of competing technology-HgCdTe material systems and III-V materials (mainly barrier detectors)-have been investigated.

Power Scaling of the Mainland Shoreline of the Atlantic Coast of the United States

NASA Astrophysics Data System (ADS)

Vasko, E.; Barton, C. C.; Geise, G. R.; Rizki, M. M.

2017-12-01

The fractal dimension of the mainland shoreline of the Atlantic coast of the United Stated from Maine to Homestead, FL has been measured in 1000 km increments using the box-counting method. The shoreline analyzed is the NOAA Medium Resolution Shoreline (https://shoreline.noaa.gov/data/datasheets/medres.html). The shoreline was reconstituted into sequentially numbered X-Y coordinate points in UTM Zone 18N which are spaced 50 meters apart, as measured continuously along the shoreline. We created a MATLAB computer code to measure the fractal dimension by box counting while "walking" along the shoreline. The range of box sizes is 0.7 to 450 km. The fractal dimension ranges from 1.0 to1.5 along the mainland shoreline of the Atlantic coast. The fractal dimension is compared with beach particle sizes (bedrock outcrop, cobbles, pebbles, sand, clay), tidal range, rate of sea level rise, rate and direction of vertical crustal movement, and wave energy, looking for correlation with the measured fractal dimensions. The results show a correlation between high fractal dimensions (1.3 - 1.4) and tectonically emergent coasts, and low fractal dimensions (1.0 - 1.2) along submergent and stable coastal regions. Fractal dimension averages 1.3 along shorelines with shoreline protection structures such as seawalls, jetties, and groins.

Dimension- and space-based intertrial effects in visual pop-out search: modulation by task demands for focal-attentional processing.

PubMed

Krummenacher, Joseph; Müller, Hermann J; Zehetleitner, Michael; Geyer, Thomas

2009-03-01

Two experiments compared reaction times (RTs) in visual search for singleton feature targets defined, variably across trials, in either the color or the orientation dimension. Experiment 1 required observers to simply discern target presence versus absence (simple-detection task); Experiment 2 required them to respond to a detection-irrelevant form attribute of the target (compound-search task). Experiment 1 revealed a marked dimensional intertrial effect of 34 ms for an target defined in a changed versus a repeated dimension, and an intertrial target distance effect, with an 4-ms increase in RTs (per unit of distance) as the separation of the current relative to the preceding target increased. Conversely, in Experiment 2, the dimension change effect was markedly reduced (11 ms), while the intertrial target distance effect was markedly increased (11 ms per unit of distance). The results suggest that dimension change/repetition effects are modulated by the amount of attentional focusing required by the task, with space-based attention altering the integration of dimension-specific feature contrast signals at the level of the overall-saliency map.

Patient safety culture perceptions in the college of dentistry

PubMed Central

Al Sweleh, Fahad Saleh; Al Saedan, Abdullah Mohammed; Al Dayel, Omar Abdullah

2018-01-01

Abstract A positive safety culture is essential to patient safety because it improves quality of care. The aim of this study was to assess staff and student perceptions of the patient safety culture in the clinics of the College of Dentistry at King Saud University in Saudi Arabia. A cross-sectional study was conducted in the College of Dentistry at King Saud University in Saudi Arabia. It included 4th and 5th year students, interns, general practitioners, and dental assistants. The data were collected by using paper-based questionnaire of modified version of the Agency for Healthcare Research and Quality Hospital Survey on Patient Safety Culture. Data were entered into SPSS Version 20. Score on a particular safety culture dimension was calculated. The overall response rate was 72.8% (390/536). Team work dimension had the highest average percent positive dimension score (72.3%) while staffing had the lowest score (10%). Dental assistant had high agreement in Teamwork dimension (87.8%); Supervisor/Manager Expectations and Actions Promoting Patient Safety dimension (66.9%); Organizational Learning—Continuous Improvement dimension (79.1%); Management Support for Patient Safety dimension (84.5%); Feedback and Communication About Error dimension (58.3%); Frequency of Events Reported dimension (54.0%); Teamwork Across Units dimension (73.2%). Most of areas perceived that there is no event reported (76.1-85.3%) in the past 12 months. Overall patient safety grade is more than moderate in the clinic. Teamwork within Units and Organizational Learning—Continuous Improvement dimension had the highest score while staffing had the lowest score. Dental assistants perceived positive score in most dimensions while students perceived slight negative score in most dimensions. PMID:29480849

First principle calculation in FeCo overlayer on GaAs substrate

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

Jain, Vishal, E-mail: vjain045@gmail.com; Lakshmi, N.; Jain, Vivek Kumar

In this work the first principle electronic structure calculation is reported for FeCo/GaAs thin film system to investigate the effect of orientation on the electronic structural properties. A unit cell describing FeCo layers and GaAs layers is constructed for (100), (110), (111) orientation with vacuum of 30Å to reduce dimensions. It is found that although the (110) orientation is energetically more favorable than others, the magnetic moment is quite large in (100) and (111) system compared to the (110) and is due to the total DOS variation with orientation.

Consumption symbols as carriers of culture: a study of Japanese and Spanish brand personality constructs.

PubMed

Aaker, J L; Benet-Martínez, V; Garolera, J

2001-09-01

This research argues that the meaning embedded in consumption symbols, such as commercial brands, can serve to represent and institutionalize the values and beliefs of a culture. Relying on a combined emic-etic approach, the authors conducted 4 studies to examine how symbolic and expressive attributes associated with commercial brands are structured and how this structure varies across 3 cultures. Studies 1 and 2 revealed a set of "brand personality" dimensions common to both Japan and the United States (Sincerity, Excitement, Competence, and Sophistication), as well as culture-specific Japanese (Peacefulness) and American (Ruggedness) dimensions. Studied 3 and 4, which extended this set of findings to Spain, yielded brand personality dimensions common to both Spain and the United States (Sincerity, Excitement, and Sophistication), plus nonshared Spanish (Passion) and American (Competence and Ruggedness) dimensions. The meaning of these brand personality dimensions is discussed in the context of cross-cultural research on values and affect, globalization issues, and cultural frame shifting.

Integration trumps selection in object recognition.

PubMed

Saarela, Toni P; Landy, Michael S

2015-03-30

Finding and recognizing objects is a fundamental task of vision. Objects can be defined by several "cues" (color, luminance, texture, etc.), and humans can integrate sensory cues to improve detection and recognition [1-3]. Cortical mechanisms fuse information from multiple cues [4], and shape-selective neural mechanisms can display cue invariance by responding to a given shape independent of the visual cue defining it [5-8]. Selective attention, in contrast, improves recognition by isolating a subset of the visual information [9]. Humans can select single features (red or vertical) within a perceptual dimension (color or orientation), giving faster and more accurate responses to items having the attended feature [10, 11]. Attention elevates neural responses and sharpens neural tuning to the attended feature, as shown by studies in psychophysics and modeling [11, 12], imaging [13-16], and single-cell and neural population recordings [17, 18]. Besides single features, attention can select whole objects [19-21]. Objects are among the suggested "units" of attention because attention to a single feature of an object causes the selection of all of its features [19-21]. Here, we pit integration against attentional selection in object recognition. We find, first, that humans can integrate information near optimally from several perceptual dimensions (color, texture, luminance) to improve recognition. They cannot, however, isolate a single dimension even when the other dimensions provide task-irrelevant, potentially conflicting information. For object recognition, it appears that there is mandatory integration of information from multiple dimensions of visual experience. The advantage afforded by this integration, however, comes at the expense of attentional selection. Copyright © 2015 Elsevier Ltd. All rights reserved.

Can One Take the Logarithm or the Sine of a Dimensioned Quantity or a Unit? Dimensional Analysis Involving Transcendental Functions

ERIC Educational Resources Information Center

Matta, Cherif F.; Massa, Lou; Gubskaya, Anna V.; Knoll, Eva

2011-01-01

The fate of dimensions of dimensioned quantities that are inserted into the argument of transcendental functions such as logarithms, exponentiation, trigonometric, and hyperbolic functions is discussed. Emphasis is placed on common misconceptions that are not often systematically examined in undergraduate courses of physical sciences. The argument…

You and Man in the Western World. A Cultural Approach. Eighth Grade Social Studies.

ERIC Educational Resources Information Center

Parsippany - Troy Hills Board of Education, Parsippany, NJ.

GRADES OR AGES: Grade 8. SUBJECT MATTER: Social Studies--You and Man in the Western World. ORGANIZATION AND PHYSICAL APPEARANCE: The guide contains five units: 1) cultural orientation; 2) social studies dimensions in Western Europe; 3) social studies dimensions in Eastern Europe and Soviet Union; 4) social studies dimensions in Latin America; and…

Quantification of structural changes in acute inflammation by fractal dimension, angular second moment and correlation.

PubMed

Stankovic, Marija; Pantic, Igor; De Luka, Silvio R; Puskas, Nela; Zaletel, Ivan; Milutinovic-Smiljanic, Sanja; Pantic, Senka; Trbovich, Alexander M

2016-03-01

The aim of the study was to examine alteration and possible application of fractal dimension, angular second moment, and correlation for quantification of structural changes in acutely inflamed tissue. Acute inflammation was induced by injection of turpentine oil into the right and left hind limb muscles of mice, whereas control animals received intramuscular saline injection. After 12 h, animals were anesthetised and treated muscles collected. The tissue was stained by hematoxylin and eosin, digital micrographs produced, enabling determination of fractal dimension of the cells, angular second moment and correlation of studied tissue. Histopathological analysis showed presence of inflammatory infiltrate and tissue damage in inflammatory group, whereas tissue structure in control group was preserved, devoid of inflammatory infiltrate. Fractal dimension of the cells, angular second moment and correlation of treated tissue in inflammatory group decreased in comparison to the control group. In this study, we were first to observe and report that fractal dimension of the cells, angular second moment, and correlation were reduced in acutely inflamed tissue, indicating loss of overall complexity of the cells in the tissue, the tissue uniformity and structure regularity. Fractal dimension, angular second moment and correlation could be useful methods for quantification of structural changes in acute inflammation. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

High-level expression, purification, crystallization and preliminary X-ray crystallographic studies of the receptor binding domain of botulinum neurotoxin serotype D

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

Zhang, Yanfeng; Gao, Xiaoli; Qin, Lin

2010-12-01

Botulinum neurotoxins (BoNTs) are highly toxic proteins for humans and can cause neuroparalytic disease botulism. Due to the limitations of production and manipulation of holoenzymes, expressing non-toxic heavy chain receptor binding domains (HCR) has become a common strategy for vaccine and antibody development. Meanwhile, large quantities and highly purified soluble proteins are required for research areas such as antibody maturation and structural biology. We present high level expression and purification of the BoNT serotype D HCR in E. coli using a codon-optimized cDNA. By varying expression conditions, especially at low temperature, the protein was expressed at a high level withmore » high solubility. About 150-200 mg protein was purified to >90% purity from 1 L cell culture. The recombinant D_HCR was crystallized and the crystals diffracted to 1.65 Å resolution. The crystals belong to space group P212121 with unit cell dimensions a = 60.8 Å, b = 89.7 Å, c = 93.9 Å. Preliminary crystallographic data analysis revealed one molecule in asymmetric unit.« less

Temporal and spatial tuning of dorsal lateral geniculate nucleus neurons in unanesthetized rats

PubMed Central

Sriram, Balaji; Meier, Philip M.

2016-01-01

Visual response properties of neurons in the dorsolateral geniculate nucleus (dLGN) have been well described in several species, but not in rats. Analysis of responses from the unanesthetized rat dLGN will be needed to develop quantitative models that account for visual behavior of rats. We recorded visual responses from 130 single units in the dLGN of 7 unanesthetized rats. We report the response amplitudes, temporal frequency, and spatial frequency sensitivities in this population of cells. In response to 2-Hz visual stimulation, dLGN cells fired 15.9 ± 11.4 spikes/s (mean ± SD) modulated by 10.7 ± 8.4 spikes/s about the mean. The optimal temporal frequency for full-field stimulation ranged from 5.8 to 19.6 Hz across cells. The temporal high-frequency cutoff ranged from 11.7 to 33.6 Hz. Some cells responded best to low temporal frequency stimulation (low pass), and others were strictly bandpass; most cells fell between these extremes. At 2- to 4-Hz temporal modulation, the spatial frequency of drifting grating that drove cells best ranged from 0.008 to 0.18 cycles per degree (cpd) across cells. The high-frequency cutoff ranged from 0.01 to 1.07 cpd across cells. The majority of cells were driven best by the lowest spatial frequency tested, but many were partially or strictly bandpass. We conclude that single units in the rat dLGN can respond vigorously to temporal modulation up to at least 30 Hz and spatial detail up to 1 cpd. Tuning properties were heterogeneous, but each fell along a continuum; we found no obvious clustering into discrete cell types along these dimensions. PMID:26936980

Crystallization and preliminary X-ray diffraction studies of θ-toxin (perfringolysin O), a pore-forming cytolysin of Clostridium perfringens

NASA Astrophysics Data System (ADS)

Sugahara, Mitsuaki; Sekino-Suzuki, Naoko; Ohno-Iwashita, Yoshiko; Miki, Kunio

1996-10-01

θ-Toxin (perfringolysin O), a cholesterol-binding, pore-forming cytolysin of Clostridium perfringens type A was crystallized by the vapor diffusion procedure using polyethyleneglycol 4000 and sodium chloride as precipitants in 2-(cyclohexylamino)ethanesulfonic acid (CHES) buffer at pH 9.5. The diffraction patterns of precession photographs indicated that the crystals belong to the orthorhombic system and the space group C222 1 with unit-cell dimensions of a = 47.7 Å, b = 182.0 Å and c = 175.8 Å. Assuming that the asymmetric unit contains one or two molecules (Mw 52 700), the Vm value is calculated as 3.6 or 1.8 Å 3/dalton, respectively. The crystals diffract X-rays to at least 3 Å resolution and are suitable for high resolution X-ray crystal structure determination.

Crystallization and preliminary X-ray analysis of copper amine oxidase from Escherichia coli K-12.

PubMed

Roh, J H; Suzuki, H; Kumagai, H; Yamashita, M; Azakami, H; Murooka, Y; Mikami, B

1994-05-13

Copper-containing monoamine oxidase (MAO) from Escherichia coli was overproduced in the periplasmic space by expression of the cloned gene. The purified MAO has been crystallized by means of the hanging drop technique using sodium citrate as a precipitant. The crystals belong to the orthorhombic system, space group P2(1)2(1)2(1), with unit cell dimensions of a = 136.1 A, b = 168.4 A and c = 81.6 A. The asymmetric unit contains one molecule of MAO, with a crystal volume per protein mass (Vm) of 2.88 A3/Da and a solvent content of 58% by volume. The crystals diffract X-rays to a resolution limit of at least 2.7 A and are resistant to X-ray radiation damage. They appear to be suitable for X-ray structure analysis.

Large-cell renormalisation and systems of dimensionality larger than the upper marginal dimension

NASA Technical Reports Server (NTRS)

Nakanishi, H.

1984-01-01

A recent argument dismissing the applicability of large-cell renormalization schemes to systems whose dimensionality is larger than the upper marginal dimension is critically discussed. In this connection, new large-cell renormalization results for the random walk for a dimensionality of 3 and 4 are presented which indicate convergence to the correct results.

The ``False Colour'' Problem

NASA Astrophysics Data System (ADS)

Serra, Jean

The emergence of new data in multidimensional function lattices is studied. A typical example is the apparition of false colours when (R,G,B) images are processed. Two lattice models are specially analysed. Firstly, one considers a mixture of total and marginal orderings where the variations of some components are governed by other ones. This constraint yields the “pilot lattices”. The second model is a cylindrical polar representation in n dimensions. In this model, data that are distributed on the unit sphere of n - 1 dimensions need to be ordered. The proposed orders, and lattices are specific to each image. They are obtained from Voronoi tesselation of the unit sphere The case of four dimensions is treated in detail and illustrated.

Analysis of beach morphodynamics on the Bragantinian mangrove peninsula (Pará, North Brazil) as prerequisite for coastal zone management recommendations

NASA Astrophysics Data System (ADS)

Krause, Gesche; Soares, Cidiane

2004-05-01

A beach profile monitoring programme was initiated in 1997 as a contribution to the development of recommendations for an integrated coastal zone management scheme of the mangrove peninsula of Bragança, State of Pará (North Brazil). It was the first scientific investigation on the coastal morphodynamics in a mangrove environment, which was opened for human use only since the mid-1970s. The observations were carried out on five sections for 4 years, on a fortnightly basis whenever possible. Temporal evolution of the beach morphology was assessed using time series of beach height, changes in profile shape, sediment transport calculations, and photographs. This unique data set for new settlement areas in this mangrove-dominated coastal zone illuminates the role of the interaction between human activities and natural coastal dynamics. Four coastal cells were identified as coastal management units, each with specific dynamic behaviour and utilisation by humans. The cells are rather small with dimensions in the order of 1-3 km. Only one of the units (cell 1) had a stable coastline during the 4 years of observation, while all others are eroding. Clearing of vegetation is the principal reason for the enhancement of the natural chronic erosion at these sites. In the wake of increasing tourism, housing was erected on the first dune ridge (cell 2) with much damage to the natural vegetation. In this unit, erosion is predominantly targeted on the dunes. In cell 3, the most important reason for the increased erosion is clearing of the adjacent fringing mangroves. This is also true for cell 4, but additionally the construction of large fishing traps, which artificially entrap sand and create sandbanks and thereby increase velocities in the tidal channel tend to enhance erosion at the shoreline. Only for cell 1 can protection measures for the still available vegetation be recommended while a planned retreat of many tourism facilities and fishermen's housings should be included in management recommendations.

Computational Homogenization of Mechanical Properties for Laminate Composites Reinforced with Thin Film Made of Carbon Nanotubes

NASA Astrophysics Data System (ADS)

El Moumen, A.; Tarfaoui, M.; Lafdi, K.

2018-06-01

Elastic properties of laminate composites based Carbone Nanotubes (CNTs), used in military applications, were estimated using homogenization techniques and compared to the experimental data. The composite consists of three phases: T300 6k carbon fibers fabric with 5HS (satin) weave, baseline pure Epoxy matrix and CNTs added with 0.5%, 1%, 2% and 4%. Two step homogenization methods based RVE model were employed. The objective of this paper is to determine the elastic properties of structure starting from the knowledge of those of constituents (CNTs, Epoxy and carbon fibers fabric). It is assumed that the composites have a geometric periodicity and the homogenization model can be represented by a representative volume element (RVE). For multi-scale analysis, finite element modeling of unit cell based two step homogenization method is used. The first step gives the properties of thin film made of epoxy and CNTs and the second is used for homogenization of laminate composite. The fabric unit cell is chosen using a set of microscopic observation and then identified by its ability to enclose the characteristic periodic repeat in the fabric weave. The unit cell model of 5-Harness satin weave fabric textile composite is identified for numerical approach and their dimensions are chosen based on some microstructural measurements. Finally, a good comparison was obtained between the predicted elastic properties using numerical homogenization approach and the obtained experimental data with experimental tests.

Structure, thermal, and impedance study of a new organic-inorganic hybrid [(CH2)7(NH3)2]CoCl4

NASA Astrophysics Data System (ADS)

Mostafa, M. F.; El-khiyami, Sh. S.; Alal, S. K.

2018-07-01

[(CH2)7(NH3)2]CoCl4 crystallizes in the triclinic system, space group P-1 with two molecules per asymmetric unit cell (Z = 2). The unit cell dimensions are a = 7.3107 (2) Å, b = 10.1841 (3) Å, c = 11.2690 (4) Å, α = 66.81 (2), β = 78.85 (12), and γ = 87.66 (2). The unit cell volume and the calculated density are 756.11 (4) Å3 and 1.463 Mg m-3, respectively. The structure of the hybrid is characterized by alternating layers of inorganic [CoCl4]2- anion and heptane diammonium cation. The organic hydrocarbon layers are packed in a stacked herring-bone manner with hydrogen bonds to the halide ions. The lattice potential energy Upot and the cation molecular volume V+ are 1856.2 kJ/mol and 0.37 nm3, respectively. DSC showed a compound (broad) peak at T1 = 331 K, T2 = 328 K with total entropy ΔS = 36.2 J/K. mol, and a λ-like endothermic peak at T3 = 296 K (ΔS = 24.9 J/K. mol). Dielectric properties are investigated at different temperatures and frequencies [260 K < T < 360 K and 0.06 kHz < f < 60 kHz, respectively]. Super-linear power law is observed for the AC conductivity, which is analyzed based on the jump relaxation model.

Computational Homogenization of Mechanical Properties for Laminate Composites Reinforced with Thin Film Made of Carbon Nanotubes

NASA Astrophysics Data System (ADS)

El Moumen, A.; Tarfaoui, M.; Lafdi, K.

2017-08-01

Elastic properties of laminate composites based Carbone Nanotubes (CNTs), used in military applications, were estimated using homogenization techniques and compared to the experimental data. The composite consists of three phases: T300 6k carbon fibers fabric with 5HS (satin) weave, baseline pure Epoxy matrix and CNTs added with 0.5%, 1%, 2% and 4%. Two step homogenization methods based RVE model were employed. The objective of this paper is to determine the elastic properties of structure starting from the knowledge of those of constituents (CNTs, Epoxy and carbon fibers fabric). It is assumed that the composites have a geometric periodicity and the homogenization model can be represented by a representative volume element (RVE). For multi-scale analysis, finite element modeling of unit cell based two step homogenization method is used. The first step gives the properties of thin film made of epoxy and CNTs and the second is used for homogenization of laminate composite. The fabric unit cell is chosen using a set of microscopic observation and then identified by its ability to enclose the characteristic periodic repeat in the fabric weave. The unit cell model of 5-Harness satin weave fabric textile composite is identified for numerical approach and their dimensions are chosen based on some microstructural measurements. Finally, a good comparison was obtained between the predicted elastic properties using numerical homogenization approach and the obtained experimental data with experimental tests.

Cohesion in Multinational Military Units

DTIC Science & Technology

2010-12-10

Assertiveness for Hofstede’s Masculinity dimension and added three dimensions: Humanistic , Performance, and Future Orientation. GLOBE researchers...values. It addresses the most profound existential issues of human life; e.g. freedom and inevitability, fear and faith, security and insecurity, right

Factors associated with student learning processes in primary health care units: a questionnaire study.

PubMed

Bos, Elisabeth; Alinaghizadeh, Hassan; Saarikoski, Mikko; Kaila, Päivi

2015-01-01

Clinical placement plays a key role in education intended to develop nursing and caregiving skills. Studies of nursing students' clinical learning experiences show that these dimensions affect learning processes: (i) supervisory relationship, (ii) pedagogical atmosphere, (iii) management leadership style, (iv) premises of nursing care on the ward, and (v) nursing teachers' roles. Few empirical studies address the probability of an association between these dimensions and factors such as student (a) motivation, (b) satisfaction with clinical placement, and (c) experiences with professional role models. The study aimed to investigate factors associated with the five dimensions in clinical learning environments within primary health care units. The Swedish version of Clinical Learning Environment, Supervision and Teacher, a validated evaluation scale, was administered to 356 graduating nursing students after four or five weeks clinical placement in primary health care units. Response rate was 84%. Multivariate analysis of variance is determined if the five dimensions are associated with factors a, b, and c above. The analysis revealed a statistically significant association with the five dimensions and two factors: students' motivation and experiences with professional role models. The satisfaction factor had a statistically significant association (effect size was high) with all dimensions; this clearly indicates that students experienced satisfaction. These questionnaire results show that a good clinical learning experience constitutes a complex whole (totality) that involves several interacting factors. Supervisory relationship and pedagogical atmosphere particularly influenced students' satisfaction and motivation. These results provide valuable decision-support material for clinical education planning, implementation, and management. Copyright © 2014 Elsevier Ltd. All rights reserved.

CSE-MECC two-dimensional capillary electrophoresis analysis of proteins in the mouse tumor cell (AtT-20) homogenate

PubMed Central

Chen, Xingguo; Fazal, Md. Abul; Dovichi, Norman J.

2007-01-01

Two-dimensional capillary electrophoresis was used for the separation of proteins and biogenic amines from the mouse AtT-20 cell line. The first-dimension capillary contained a TRIS-CHES-SDS-dextran buffer to perform capillary sieving electrophoresis, which is based on molecular weight of proteins. The second-dimension capillary contained a TRIS-CHES-SDS buffer for micel1ar electrokinetic capillary chromatography. After a 61 seconds preliminary separation, fractions from the first-dimension capillary were successively transferred to the second-dimension capillary, where they further separated by MECC. The two-dimensional separation required 60 minutes. PMID:17637850

The fractal dimension of cell membrane correlates with its capacitance: A new fractal single-shell model

PubMed Central

Wang, Xujing; Becker, Frederick F.; Gascoyne, Peter R. C.

2010-01-01

The scale-invariant property of the cytoplasmic membrane of biological cells is examined by applying the Minkowski–Bouligand method to digitized scanning electron microscopy images of the cell surface. The membrane is found to exhibit fractal behavior, and the derived fractal dimension gives a good description of its morphological complexity. Furthermore, we found that this fractal dimension correlates well with the specific membrane dielectric capacitance derived from the electrorotation measurements. Based on these findings, we propose a new fractal single-shell model to describe the dielectrics of mammalian cells, and compare it with the conventional single-shell model (SSM). We found that while both models fit with experimental data well, the new model is able to eliminate the discrepancy between the measured dielectric property of cells and that predicted by the SSM. PMID:21198103

Design of metamirrors for linear to circular polarization conversion with super-octave bandwidth

NASA Astrophysics Data System (ADS)

Fartookzadeh, Mahdi

2017-10-01

In this paper, bandwidth improvement of reflection-mode linear to circular polarization converters (RMCPs) is studied. The proposed RMCP is based on multi-layer rectangular patches. Equivalent transmission line circuit of multi-layer reflection-mode polarization converters is used for designing the proposed metamirror. In addition, the approximate equation of axial ratio (AR) of the reflected wave is obtained from the structures containing rectangular patches on each layer. Polarization converters containing multi-layer rectangular patches can be utilized for different ranges of frequencies. However, the frequency range of 2-8 THz is considered in this paper without losing generality. The incident wave is assumed to be linearly polarized with 45° polarization angle. AR equation is used for initial optimization of the dimensions of rectangular patches to obtain the widest possible bandwidth of RMCPs with two- and three-layer patches. Secondary optimization is applied after specifying largest dimensions of the unit cell and excluding them from the variables of optimization. Finally, modified dimensions of the three-layer RMCP are obtained using parametrical study in simulations. The proposed three-layer polarization converter has the 3 dB axial ratio bandwidth of more than 116% and the permitted incident angle of higher than 25°.

The complexity of translationally invariant low-dimensional spin lattices in 3D

NASA Astrophysics Data System (ADS)

Bausch, Johannes; Piddock, Stephen

2017-11-01

In this theoretical paper, we consider spin systems in three spatial dimensions and consider the computational complexity of estimating the ground state energy, known as the local Hamiltonian problem, for translationally invariant Hamiltonians. We prove that the local Hamiltonian problem for 3D lattices with face-centered cubic unit cells and 4-local translationally invariant interactions between spin-3/2 particles and open boundary conditions is QMAEXP-complete, where QMAEXP is the class of problems which can be verified in exponential time on a quantum computer. We go beyond a mere embedding of past hard 1D history state constructions, for which the local spin dimension is enormous: even state-of-the-art constructions have local dimension 42. We avoid such a large local dimension by combining some different techniques in a novel way. For the verifier circuit which we embed into the ground space of the local Hamiltonian, we utilize a recently developed computational model, called a quantum ring machine, which is especially well suited for translationally invariant history state constructions. This is encoded with a new and particularly simple universal gate set, which consists of a single 2-qubit gate applied only to nearest-neighbour qubits. The Hamiltonian construction involves a classical Wang tiling problem as a binary counter which translates one cube side length into a binary description for the encoded verifier input and a carefully engineered history state construction that implements the ring machine on the cubic lattice faces. These novel techniques allow us to significantly lower the local spin dimension, surpassing the best translationally invariant result to date by two orders of magnitude (in the number of degrees of freedom per coupling). This brings our models on par with the best non-translationally invariant construction.

Static compression of Ca(OH)2 at room temperature - Observations of amorphization and equation of state measurements to 10.7 GPa

NASA Technical Reports Server (NTRS)

Meade, Charles; Jeanloz, Raymond

1990-01-01

X-ray diffraction measurements are reported for Ca(OH)2 portlandite as it is compressed to 37.6 GPa in the diamond cell at room temperature. Between 10.7 and 15.4 GPa crystalline Ca(OH)2 transforms to a glass, and on decompression the glass recrystallizes between 3.6 and 5.1 GPa. Below pressures of 10.7 GPa the elastic compression of crystalline Ca(OH)2 was measured. A finite strain analysis of these data shows that the isothermal bulk modulus and its pressure derivative are 37.8 + or - 1.8 GPa and 5.2 + or - 0.7 at zero pressure. The change in the unit cell dimensions indicates that the linear incompressibilities of Ca(OH)2 differ by a factor of three.

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.

Validation of the French version of the Hospital Survey on Patient Safety Culture questionnaire.

PubMed

Occelli, P; Quenon, J-L; Kret, M; Domecq, S; Delaperche, F; Claverie, O; Castets-Fontaine, B; Amalberti, R; Auroy, Y; Parneix, P; Michel, P

2013-09-01

To assess the psychometric properties of the French version of the Hospital Survey on Patient Safety Culture questionnaire (HSOPSC) and study the hierarchical structure of the measured dimensions. Cross-sectional survey of the safety culture. 18 acute care units of seven hospitals in South-western France. Full- and part-time healthcare providers who worked in the units. None. Item responses measured with 5-point agreement or frequency scales. Data analyses A principal component analysis was used to identify the emerging components. Two structural equation modeling methods [LInear Structural RELations (LISREL) and Partial Least Square (PLS)] were used to verify the model and to study the relative importance of the dimensions. Internal consistency of the retained dimensions was studied. A test-retest was performed to assess reproducibility of the items. Overall response rate was 77% (n = 401). A structure in 40 items grouped in 10 dimensions was proposed. The LISREL approach showed acceptable data fit of the proposed structure. The PLS approach indicated that three dimensions had the most impact on the safety culture: 'Supervisor/manager expectations & actions promoting safety' 'Organizational learning-continuous improvement' and 'Overall perceptions of safety'. Internal consistency was above 0.70 for six dimensions. Reproducibility was considered good for four items. The French HSOPSC questionnaire showed acceptable psychometric properties. Classification of the dimensions should guide future development of safety culture improving action plans.

40 CFR 270.23 - Specific part B information requirements for miscellaneous units.

Code of Federal Regulations, 2010 CFR

2010-07-01

... requirements for miscellaneous units. 270.23 Section 270.23 Protection of Environment ENVIRONMENTAL PROTECTION... characteristics, materials of construction, and dimensions of the unit; (2) Detailed plans and engineering reports... address and ensure compliance of the unit with each factor in the environmental performance standards of...

Small-cluster renormalization group in Ising and Blume-Emery-Griffiths models with ferromagnetic, antiferromagnetic, and quenched disordered magnetic interactions

NASA Astrophysics Data System (ADS)

Antenucci, F.; Crisanti, A.; Leuzzi, L.

2014-07-01

The Ising and Blume-Emery-Griffiths (BEG) models' critical behavior is analyzed in two dimensions and three dimensions by means of a renormalization group scheme on small clusters made of a few lattice cells. Different kinds of cells are proposed for both ordered and disordered model cases. In particular, cells preserving a possible antiferromagnetic ordering under renormalization allow for the determination of the Néel critical point and its scaling indices. These also provide more reliable estimates of the Curie fixed point than those obtained using cells preserving only the ferromagnetic ordering. In all studied dimensions, the present procedure does not yield a strong-disorder critical point corresponding to the transition to the spin-glass phase. This limitation is thoroughly analyzed and motivated.

The patient safety culture: a systematic review by characteristics of Hospital Survey on Patient Safety Culture dimensions.

PubMed

Reis, Cláudia Tartaglia; Paiva, Sofia Guerra; Sousa, Paulo

2018-05-08

To learn the weaknesses and strengths of safety culture as expressed by the dimensions measured by the Hospital Survey on Patient Safety Culture (HSOPSC) at hospitals in the various cultural contexts. The aim of this study was to identify studies that have used the HSOPSC to collect data on safety culture at hospitals; to survey their findings in the safety culture dimensions and possible contributions to improving the quality and safety of hospital care. Medline (via PubMed), Web of Science and Scopus were searched from 2005 to July 2016 in English, Portuguese and Spanish. Studies were identified using specific search terms and inclusion criteria. A total of 33 articles, reporting on 21 countries, was included. Scores were extracted by patient safety culture dimensions assessed by the HSOPSC. The quality of the studies was evaluated by the STROBE Statement. The dimensions that proved strongest were 'Teamwork within units' and 'Organisational learning-continuous improvement'. Particularly weak dimensions were 'Non-punitive response to error', 'Staffing', 'Handoffs and transitions' and 'Teamwork across units'. The studies revealed a predominance of hospital organisational cultures that were underdeveloped or weak as regards patient safety. For them to be effective, safety culture evaluation should be tied to strategies designed to develop safety culture hospital-wide.

Generation of a composite grid for turbine flows and consideration of a numerical scheme

NASA Technical Reports Server (NTRS)

Choo, Y.; Yoon, S.; Reno, C.

1986-01-01

A composite grid was generated for flows in turbines. It consisted of the C-grid (or O-grid) in the immediate vicinity of the blade and the H-grid in the middle of the blade passage between the C-grids and in the upstream region. This new composite grid provides better smoothness, resolution, and orthogonality than any single grid for a typical turbine blade with a large camber and rounded leading and trailing edges. The C-H (or O-H) composite grid has an unusual grid point that is connected to more than four neighboring nodes in two dimensions (more than six neighboring nodes in three dimensions). A finite-volume lower-upper (LU) implicit scheme to be used on this grid poses no problem and requires no special treatment because each interior cell of this composite grid has only four neighboring cells in two dimensions (six cells in three dimensions). The LU implicit scheme was demonstrated to be efficient and robust for external flows in a broad flow regime and can be easily applied to internal flows and extended from two to three dimensions.

Work culture among healthcare personnel in a palliative medicine unit.

PubMed

André, Beate; Sjøvold, Endre; Rannestad, Toril; Holmemo, Marte; Ringdal, Gerd I

2013-04-01

Understanding and assessing health care personnel's work culture in palliative care is important, as a conflict between "high tech" and "high touch" is present. Implementing necessary changes in behavior and procedures may imply a profound challenge, because of this conflict. The aim of this study was to explore the work culture at a palliative medicine unit (PMU). Healthcare personnel (N = 26) at a PMU in Norway comprising physicians, nurses, physiotherapists, and others filled in a questionnaire about their perception of the work culture at the unit. The Systematizing Person-Group Relations (SPGR) method was used for gathering data and for the analyses. This method applies six different dimensions representing different aspects of a work culture (Synergy, Withdrawal, Opposition, Dependence, Control, and Nurture) and each dimension has two vectors applied. The method seeks to explore which aspects dominate the particular work culture, identifying challenges, limitations, and opportunities. The findings were compared with a reference group of 347 ratings of well-functioning Norwegian organizations, named the "Norwegian Norm." The healthcare personnel working at the PMU had significantly higher scores than the "Norwegian Norm" in both vectors in the "Withdrawal" dimension and significant lower scores in both vectors in the "Synergy," "Control," and "Dependence" dimensions. Healthcare personnel at the PMU have a significantly different perception of their work culture than do staff in "well-functioning organizations" in several dimensions. The low score in the "Synergy" and "Control" dimensions indicate lack of engagement and constructive goal orientation behavior, and not being in a position to change their behavior. The conflict between "high tech" and "high touch" at a PMU seems to be an obstacle when implementing new procedures and alternative courses of action.

Multiprofessional Primary Care Units: What Affects the Clinical Performance of Italian General Practitioners?

PubMed

Armeni, Patrizio; Compagni, Amelia; Longo, Francesco

2014-08-01

Multiprofessional primary care models promise to deliver better care and reduce waste. This study evaluates the impact of such a model, the primary care unit (PCU), on three outcomes. A multilevel analysis within a "pre- and post-PCU" study design and a cross-sectional analysis were conducted on 215 PCUs located in the Emilia-Romagna region in Italy. Seven dimensions captured a set of processes and services characterizing a well-functioning PCU, or its degree of vitality. The impact of each dimension on outcomes was evaluated. The analyses show that certain dimensions of PCU vitality (i.e., the possibility for general practitioners to meet and share patients) can lead to better outcomes. However, dimensions related to the interaction and the joint works of general practitioners with other professionals tend not to have a significant or positive impact. This suggests that more effort needs to be invested to realize all the potential benefits of the PCU's multiprofessional approach to care. © The Author(s) 2014.

Which functional unit to identify sustainable foods?

PubMed

Masset, Gabriel; Vieux, Florent; Darmon, Nicole

2015-09-01

In life-cycle assessment, the functional unit defines the unit for calculation of environmental indicators. The objective of the present study was to assess the influence of two functional units, 100 g and 100 kcal (420 kJ), on the associations between three dimensions for identifying sustainable foods, namely environmental impact (via greenhouse gas emissions (GHGE)), nutritional quality (using two distinct nutrient profiling systems) and price. GHGE and price data were collected for individual foods, and were each expressed per 100 g and per 100 kcal. Two nutrient profiling models, SAIN,LIM and UK Ofcom, were used to assess foods' nutritional quality. Spearman correlations were used to assess associations between variables. Sustainable foods were identified as those having more favourable values for all three dimensions. The French Individual and National Dietary Survey (INCA2), 2006-2007. Three hundred and seventy-three foods highly consumed in INCA2, covering 65 % of total energy intake of adult participants. When GHGE and price were expressed per 100 g, low-GHGE foods had a lower price and higher SAIN,LIM and Ofcom scores (r=0·59, -0·34 and -0·43, respectively), suggesting a compatibility between the three dimensions; 101 and 100 sustainable foods were identified with SAIN,LIM and Ofcom, respectively. When GHGE and price were expressed per 100 kcal, low-GHGE foods had a lower price but also lower SAIN,LIM and Ofcom scores (r=0·67, 0·51 and 0·47, respectively), suggesting that more environment-friendly foods were less expensive but also less healthy; thirty-four sustainable foods were identified with both SAIN,LIM and Ofcom. The choice of functional unit strongly influenced the compatibility between the sustainability dimensions and the identification of sustainable foods.

Electromagnetic reprogrammable coding-metasurface holograms.

PubMed

Li, Lianlin; Jun Cui, Tie; Ji, Wei; Liu, Shuo; Ding, Jun; Wan, Xiang; Bo Li, Yun; Jiang, Menghua; Qiu, Cheng-Wei; Zhang, Shuang

2017-08-04

Metasurfaces have enabled a plethora of emerging functions within an ultrathin dimension, paving way towards flat and highly integrated photonic devices. Despite the rapid progress in this area, simultaneous realization of reconfigurability, high efficiency, and full control over the phase and amplitude of scattered light is posing a great challenge. Here, we try to tackle this challenge by introducing the concept of a reprogrammable hologram based on 1-bit coding metasurfaces. The state of each unit cell of the coding metasurface can be switched between '1' and '0' by electrically controlling the loaded diodes. Our proof-of-concept experiments show that multiple desired holographic images can be realized in real time with only a single coding metasurface. The proposed reprogrammable hologram may be a key in enabling future intelligent devices with reconfigurable and programmable functionalities that may lead to advances in a variety of applications such as microscopy, display, security, data storage, and information processing.Realizing metasurfaces with reconfigurability, high efficiency, and control over phase and amplitude is a challenge. Here, Li et al. introduce a reprogrammable hologram based on a 1-bit coding metasurface, where the state of each unit cell of the coding metasurface can be switched electrically.

Characterization of low-frequency acoustic wave propagation through a periodic corrugated waveguide

NASA Astrophysics Data System (ADS)

Jiang, Changyong; Huang, Lixi

2018-03-01

In this paper, a periodic corrugated waveguide structure is proposed, and its unit-cell is analyzed by the wave finite element method. In low-frequency range, the unit-cell is treated as an equivalent fluid through a homogenization process, and the equivalent acoustic parameters are obtained, which are validated by finite structure simulations and experiments. The proposed structure is shown to add tortuosity to the waveguide, hence higher equivalent fluid density is achieved, while the system elastic modulus remains unchanged. As a result, the equivalent speed of sound is smaller than normal air. The application of such change of speed of sound is demonstrated in the classic quarter-wavelength resonator based on the corrugated waveguide, which gives a lower resonance frequency with the same side branch length. When the waveguide is filled with porous materials, the added tortuosity enhances the broadband, low-frequency sound absorption by increasing the equivalent mass without bringing in excess damping, the latter being partly responsible for the poor performance of usual porous materials in the low-frequency region. Therefore, the proposed structure provides another dimension for the design and optimization of porous sound absorption materials.

The Conditioning Influence of Organization Size Upon Managerial Practice

ERIC Educational Resources Information Center

Mahoney, Thomas A.; And Others

1972-01-01

Two dimensions of organization size -- unit size and size of parent organization -- are analyzed for independent and joint relationships with various dimensions of organizational behavior and managerial practice. Results suggest that managerial practices of delegation, staffing, and direction vary with size and moderate expected size influences…

Ethical Misconduct of Business Students: Some New Evidence

ERIC Educational Resources Information Center

Deshpande, Satish P.; Joseph, Jacob; Berry, Kevin

2012-01-01

This study examines ethical misconduct of 193 business students in four universities in the United States. In addition to self-reported ethical behavior, two dimensions of emotional intelligence (self-emotions appraisal and others emotions appraisal) significantly impacted student misconduct. None of the other dimensions of emotional intelligence…

The Technological Dimensions of International Competitiveness.

ERIC Educational Resources Information Center

National Academy of Engineering, Washington, DC. Committee on Technology Issues That Impact International Competitiveness.

This report focuses primarily on the technological dimensions of competitiveness in the United States with its capability to: create and effectively use technology; increase the value added to goods and services through the application of technology; manage technology in industry for more effective relationships among companies, universities, and…

Organization Structure and Administrative Control: A Question of Dimensionality.

ERIC Educational Resources Information Center

Montanari, John R.; Freedman, Sara M.

1981-01-01

Used a sample of national firms (N=836) to investigate the relationship between specialization, formalization, and centralization in the functional work unit. Data indicated that the three variables compose a single dimension of organizational structure. Another finding was that, within this dimension, specialization, formalization, and…

Sunnybrook's matrix organizational model--moving ahead.

PubMed

Ellis, P H; Gaskin, P M

1988-01-01

Traditionally, hospitals have denied the true intricacy of their organization by forcing all reporting relationships into a single structure. To address this complexity, Sunnybrook has developed three independent, yet interrelated, organization dimensions. Three structures--the traditional, the clinical unit and the programmatic dimension--provide a better link of accountability by holding departments responsible for the efficiency of their operations, holding physicians accountable for the resource implication of volume and case mix, and ensuring that the activities of the hospital's departments and clinical units are in line with hospital's overall mission and programs.

Conformational analysis of (1. -->. 4)-. beta. -D-mannan triacetate

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

Deslandes, Y.; Marchessault, R.H.; Bluhm, T.L.

1983-01-01

In wood, algae, and tubers, glucomannans have varying mannose-to-glucose ratios (M/G). Since diffraction on glucomannans of widely varying M/G do not show significant change in unit-cell base plane dimensions, the authors have suggested that isomorphous replacement may occur in glucomannans. To further investigate this point, it has been undertaken conformational analysis of glucomannan triacetate in which the X-ray fiber diagram suggests that two nonequivalent residues make up the asymmetric unit. X-ray fiber diagrams of the triacetate of glucomannan from Tubera salep show twofold symmetry along the chain axis with a fiber repeat of 1.6 nm. This implies that the asymmetricmore » unit is composed of two pyranose rings since the virtual bond length of a single pyranose ring cannot be greater than approximately 0.54 nm. By using empirical potential functions, it could be shown that the minimum internal energy of a mannan triacetate chain corresponds to a state where contiguous mannose triacetate units are not conformationally equivalent. This supports the hypothesis of mannobiose hexaacetate as the asymmetric unit. Furthermore, introduction of glucose triacetate into the backbone did not change the minimum energy conformation, thereby lending support to the isomorphous replacement concept in crystalline glucomannans. 19 references, 13 figures, 2 tables.« less

Characteristics of unit-level patient safety culture in hospitals in Japan: a cross-sectional study.

PubMed

Fujita, Shigeru; Seto, Kanako; Kitazawa, Takefumi; Matsumoto, Kunichika; Hasegawa, Tomonori

2014-10-22

Patient safety culture (PSC) has an important role in determining safety and quality in healthcare. Currently, little is known about the status of unit-level PSC in hospitals in Japan. To develop appropriate strategies, characteristics of unit-level PSC should be investigated. Work units may be classified according to the characteristics of PSC, and common problems and appropriate strategies may be identified for each work unit category. This study aimed to clarify the characteristics of unit-level PSC in hospitals in Japan. In 2012, a cross-sectional study was conducted at 18 hospitals in Japan. The Hospital Survey on Patient Safety Culture questionnaire, developed by the United States Agency for Healthcare Research and Quality, was distributed to all healthcare workers (n =12,076). Percent positive scores for 12 PSC sub-dimensions were calculated for each unit, and cluster analysis was used to categorise the units according to the percent positive scores. A generalised linear mixed model (GLMM) was used to analyse the results of the cluster analysis, and odds ratios (ORs) for categorisation as high-PSC units were calculated for each unit type. A total of 9,124 respondents (75.6%) completed the questionnaire, and valid data from 8,700 respondents (72.0%) were analysed. There were 440 units in the 18 hospitals. According to the percent positive scores for the 12 sub-dimensions, the 440 units were classified into 2 clusters: high-PSC units (n =184) and low-PSC units (n =256). Percent positive scores for all PSC sub-dimensions for high-PSC units were significantly higher than those for low-PSC units. The GLMM revealed that the combined unit type of 'Obstetrics and gynaecology ward, perinatal ward or neonatal intensive care unit' was significantly more likely to be categorised as high-PSC units (OR =9.7), and 'Long-term care ward' (OR =0.2), 'Rehabilitation unit' (OR =0.2) and 'Administration unit' (OR =0.3) were significantly less likely to be categorised as high-PSC units. Our study findings demonstrate that PSC varies considerably among different unit types in hospitals in Japan. Factors contributing to low PSC should be identified and possible measures for improving PSC should be developed and initiated.

Negotiating Identity Development among Undocumented Immigrant Students

ERIC Educational Resources Information Center

Ellis, Lauren Marie

2010-01-01

This purpose of this qualitative dissertation study was to capture the meaning and various dimensions related to being an undocumented immigrant youth in the United States, and to develop a grounded theory regarding how undocumented immigrant students negotiate their identity development in light of these dimensions. A semi-structured interview…

7 CFR 51.320 - Diameter.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Apples Definitions § 51.320 Diameter. When measuring for minimum size, “diameter” means the greatest dimension of the apple measured at right angles to... dimension of the apple determined by passing the apple through a round opening in any position. U.S...

7 CFR 51.320 - Diameter.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Apples Definitions § 51.320 Diameter. When measuring for minimum size, “diameter” means the greatest dimension of the apple measured at right angles to... dimension of the apple determined by passing the apple through a round opening in any position. U.S...

Economic Dimension of Ferry Operations in Missouri, Kentucky and Tennessee : the Dorena-Hickman Ferry.

DOT National Transportation Integrated Search

Ferries have a long-standing role in moving people and commerce on the nations waterways and rivers and continue to play a vital economic role in many areas across the United States. This analysis considers the economic dimensions of the Dorena-Hi...

An Approach to Embedded Training for Future Leaders and Staff

DTIC Science & Technology

2009-10-01

13. SUPPLEMENTARY NOTES See also ADA562526. RTO-MP-HFM-169 Human Dimensions in Embedded Virtual Simulation (Les dimensions humaines dans la...order to better capitalize on follow-on operations. 4.10 Theme 7: Sustain Unit Operations Theme 7 is defined as the ability of Soldiers and

Practicum Students' Verbal Responses to Different Clients

ERIC Educational Resources Information Center

Palisi, Anthony T.; Ruzicka, Mary F.

1974-01-01

Counselor trainees' verbal behavior in two initial interview settings, one each with an active and passive client, was significantly different. Verbal behavior was viewed from two perspectives; along the dimension of broad classification by categories of behavior and along the dimension of 3-6 second units of verbal interaction. (Author)

Definition and Measures of Individual and Unit Readiness and Family Phenomena Affecting It

DTIC Science & Technology

1991-02-01

deployability (Army task/mission) is a new dimension that emerged from the content analysis of the critical incidents. It assesses whether deployment would be...or were brought up by only one or two workshop participants, we decided to include them anyway in the new , expanded list of dimensions. In that way...incidents. Although the 41 participants in the workshops wrote 172 individual readiness critical incidents, no new dimensions were apparent in the content

Emotion categories and dimensions in the facial communication of affect: An integrated approach.

PubMed

Mehu, Marc; Scherer, Klaus R

2015-12-01

We investigated the role of facial behavior in emotional communication, using both categorical and dimensional approaches. We used a corpus of enacted emotional expressions (GEMEP) in which professional actors are instructed, with the help of scenarios, to communicate a variety of emotional experiences. The results of Study 1 replicated earlier findings showing that only a minority of facial action units are associated with specific emotional categories. Likewise, facial behavior did not show a specific association with particular emotional dimensions. Study 2 showed that facial behavior plays a significant role both in the detection of emotions and in the judgment of their dimensional aspects, such as valence, arousal, dominance, and unpredictability. In addition, a mediation model revealed that the association between facial behavior and recognition of the signaler's emotional intentions is mediated by perceived emotional dimensions. We conclude that, from a production perspective, facial action units convey neither specific emotions nor specific emotional dimensions, but are associated with several emotions and several dimensions. From the perceiver's perspective, facial behavior facilitated both dimensional and categorical judgments, and the former mediated the effect of facial behavior on recognition accuracy. The classification of emotional expressions into discrete categories may, therefore, rely on the perception of more general dimensions such as valence and arousal and, presumably, the underlying appraisals that are inferred from facial movements. (c) 2015 APA, all rights reserved).

Transverse Tensile Properties of 3 Dimension-4 Directional Braided Cf/SiC Composite Based on Double-Scale Model

NASA Astrophysics Data System (ADS)

Niu, Xuming; Sun, Zhigang; Song, Yingdong

2017-11-01

In this thesis, a double-scale model for 3 Dimension-4 directional(3D-4d) braided C/SiC composites(CMCs) has been proposed to investigate mechanical properties of it. The double-scale model involves micro-scale which takes fiber/matrix/porosity in fibers tows into consideration and the unit cell scale which considers the 3D-4d braiding structure. Basing on the Micro-optical photographs of composite, we can build a parameterized finite element model that reflects structure of 3D-4d braided composites. The mechanical properties of fiber tows in transverse direction are studied by combining the crack band theory for matrix cracking and cohesive zone model for interface debonding. Transverse tensile process of 3D-4d CMCs can be simulated by introducing mechanical properties of fiber tows into finite element of 3D-4d braided CMCs. Quasi-static tensile tests of 3D-4d braided CMCs have been performed with PWS-100 test system. The predicted tensile stress-strain curve by the double scale model finds good agreement with the experimental results.

Crystallization of beef heart cytochrome c oxidase

NASA Astrophysics Data System (ADS)

Yoshikawa, Shinya; Shinzawa, Kyoko; Tsukihara, Tomitake; Abe, Toshio; Caughey, Winslow S.

1991-03-01

The three-dimensional structure of cytochrome c oxidase, a complex (multimetal, multisubunit) membrane protein is critical to elucidation of the mechanism of the enzymic reactions and their control. Our recent developments in the crystallization of the enzyme isolated from beef hearts are presented. The crystals appeared more readily at higher protein concentration, lower ionic strength, higher detergent concentration (Brij-35) and lower temperature. Large crystals were obtained by changing one of these parameters to the crystallization point as slowly as possible, keeping the other parameters constant. Increasing the detergent concentration was the most successful method, producing green crystals of the resting oxidized form as hexagonal bipyramids with typical dimensions of 0.6 mm. The usual procedures for crystallization of water soluble proteins, such as increasing ionic strength by vapor diffusion, were not applicable for this enzyme. Crystals of the resting oxidized enzyme belong to a space group of P6 2 or P6 4 with cell dimensions, a = b = 208.7 Å and c = 282.3 Å. The Patterson function shows that the crystal exhibited a non-crystallographic two-fold axis parallel to the c-axis in the asymmetric unit.

Incommensurate crystallography without additional dimensions.

PubMed

Kocian, Philippe

2013-07-01

It is shown that the Euclidean group of translations, when treated as a Lie group, generates translations not only in Euclidean space but on any space, curved or not. Translations are then not necessarily vectors (straight lines); they can be any curve compatible with the parameterization of the considered space. In particular, attention is drawn to the fact that one and only one finite and free module of the Lie algebra of the group of translations can generate both modulated and non-modulated lattices, the modulated character being given only by the parameterization of the space in which the lattice is generated. Moreover, it is shown that the diffraction pattern of a structure is directly linked to the action of that free and finite module. In the Fourier transform of a whole structure, the Fourier transform of the electron density of one unit cell (i.e. the structure factor) appears concretely, whether the structure is modulated or not. Thus, there exists a neat separation: the geometrical aspect on the one hand and the action of the group on the other, without requiring additional dimensions.

Three-dimensional single-particle tracking in live cells: news from the third dimension

NASA Astrophysics Data System (ADS)

Dupont, A.; Gorelashvili, M.; Schüller, V.; Wehnekamp, F.; Arcizet, D.; Katayama, Y.; Lamb, D. C.; Heinrich, D.

2013-07-01

Single-particle tracking (SPT) is of growing importance in the biophysical community. It is used to investigate processes such as drug and gene delivery, viral uptake, intracellular trafficking or membrane-bound protein mobility. Traditionally, SPT is performed in two dimensions (2D) because of its technical simplicity. However, life occurs in three dimensions (3D) and many methods have been recently developed to track particles in 3D. Now, is the third dimension worth the effort? Here we investigate the differences between the 2D and 3D analyses of intracellular transport with the 3D development of a time-resolved mean square displacement (MSD) analysis introduced previously. The 3D trajectories, and the 2D projections, of fluorescent nanoparticles were obtained with an orbital tracking microscope in two different cell types: in Dictyostelium discoideum ameba and in adherent, more flattened HuH-7 human cells. As expected from the different 3D organization of both cells’ cytoskeletons, a third of the active transport was lost upon projection in the ameba whereas the identification of the active phases was barely affected in the HuH-7 cells. In both cell types, we found intracellular diffusion to be anisotropic and the diffusion coefficient values derived from the 2D analysis were therefore biased.

A new high pressure sapphire nuclear magnetic resonance cell

NASA Astrophysics Data System (ADS)

Bai, Shi; Taylor, Craig M.; Mayne, Charles L.; Pugmire, Ronald J.; Grant, David M.

1996-01-01

A new version of a single-crystal sapphire high pressure nuclear magnetic resonance (NMR) cell is described that is capable of controlling the sample pressure independent of the temperature. A movable piston inside the cell adjusts and controls the sample pressure from ambient conditions to 200 atm within ±0.3 atm. The linewidth at half-height for a 13C spectrum of carbon dioxide at 15 °C and 57.8 atm is found to be 0.5 Hz. The carbon dioxide gas/liquid phase transition is clearly observed by measuring 13C chemical shifts as the sample pressure approaches equilibrium. The time required for this NMR cell to reach equilibrium with its surroundings is relatively short, usually 15-30 min. The cell body has the same outer dimensions of a standard spinning turbine and fits into a standard 10 mm commercial probehead capable of controlling the sample temperature using the spectrometer's variable temperature unit. The flexibility of the device and the increased speed in making the measurement is demonstrated. Such control of important thermodynamic variables facilitates the NMR study of important biochemical and chemical reactions in gas, liquid, and supercritical fluid environments.

Scale-up of Carbon/Carbon Bipolar Plates

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

David P. Haack

2009-04-08

This project was focused upon developing a unique material technology for use in PEM fuel cell bipolar plates. The carbon/carbon composite material developed in this program is uniquely suited for use in fuel cell systems, as it is lightweight, highly conductive and corrosion resistant. The project further focused upon developing the manufacturing methodology to cost-effectively produce this material for use in commercial fuel cell systems. United Technology Fuel Cells Corp., a leading fuel cell developer was a subcontractor to the project was interested in the performance and low-cost potential of the material. The accomplishments of the program included the developmentmore » and testing of a low-cost, fully molded, net-shape carbon-carbon bipolar plate. The process to cost-effectively manufacture these carbon-carbon bipolar plates was focused on extensively in this program. Key areas for cost-reduction that received attention in this program was net-shape molding of the detailed flow structures according to end-user design. Correlations between feature detail and process parameters were formed so that mold tooling could be accurately designed to meet a variety of flow field dimensions. A cost model was developed that predicted the cost of manufacture for the product in near-term volumes and long-term volumes (10+ million units per year). Because the roduct uses lowcost raw materials in quantities that are less than competitive tech, it was found that the cost of the product in high volume can be less than with other plate echnologies, and can meet the DOE goal of $4/kW for transportation applications. The excellent performance of the all-carbon plate in net shape was verified in fuel cell testing. Performance equivalent to much higher cost, fully machined graphite plates was found.« less

Selective modulation of cell response on engineered fractal silicon substrates

PubMed Central

Gentile, Francesco; Medda, Rebecca; Cheng, Ling; Battista, Edmondo; Scopelliti, Pasquale E.; Milani, Paolo; Cavalcanti-Adam, Elisabetta A.; Decuzzi, Paolo

2013-01-01

A plethora of work has been dedicated to the analysis of cell behavior on substrates with ordered topographical features. However, the natural cell microenvironment is characterized by biomechanical cues organized over multiple scales. Here, randomly rough, self-affinefractal surfaces are generated out of silicon,where roughness Ra and fractal dimension Df are independently controlled. The proliferation rates, the formation of adhesion structures, and the morphology of 3T3 murine fibroblasts are monitored over six different substrates. The proliferation rate is maximized on surfaces with moderate roughness (Ra ~ 40 nm) and large fractal dimension (Df ~ 2.4); whereas adhesion structures are wider and more stable on substrates with higher roughness (Ra ~ 50 nm) and lower fractal dimension (Df ~ 2.2). Higher proliferation occurson substrates exhibiting densely packed and sharp peaks, whereas more regular ridges favor adhesion. These results suggest that randomly roughtopographies can selectively modulate cell behavior. PMID:23492898

Entrepreneurship: A Senior High School Home Economics Career Exploration Unit.

ERIC Educational Resources Information Center

Fanslow, Alyce M.; Compton, Cheryl W.

Entrepreneurship is a career option through which home economics teachers can challenge their students who have the independence, skills, and self-discipline necessary to succeed as small business owners. This unit was developed to assist home economics teachers in incorporating an entrepreneurial dimension into their programs. The unit contains…

Morphogenesis and Complexity of the Tumor Patterns

NASA Astrophysics Data System (ADS)

Izquierdo-Kulich, E.; Nieto-Villar, J. M.

A mechanism to describe the apoptosis process at mesoscopic level through p53 is proposed in this paper. A deterministic model given by three differential equations is deduced from the mesoscopic approach, which exhibits sustained oscillations caused by a supercritical Andronov-Hopf bifurcation. Taking as hypothesis that the p53 sustained oscillation is the fundamental mechanism for apoptosis regulation; the model predicts that it is necessary a strict control of p53 to stimulated it, which is an important consideration to established new therapy strategy to fight cancer. The mathematical modeling of tumor growth allows us to describe the most important regularities of these systems. A stochastic model, based on the most important processes that take place at the level of individual cells, is proposed to predict the dynamical behavior of the expected radius of the tumor and its fractal dimension. It was found that the tumor has a characteristic fractal dimension, which contains the necessary information to predict the tumor growth until it reaches a stationary state. The mathematical modeling of tumor growth is an approach to explain the complex nature of these systems. A model that describes tumor growth was obtained by using a mesoscopic formalism and fractal dimension. This model theoretically predicts the relation between the morphology of the cell pattern and the mitosis/apoptosis quotient that helps to predict tumor growth from tumoral cells fractal dimension. The relation between the tumor macroscopic morphology and the cell pattern morphology is also determined. This could explain why the interface fractal dimension decreases with the increase of the cell pattern fractal dimension and consequently with the increase of the mitosis/apoptosis relation. Indexes to characterize tumoral cell proliferation and invasion capacities are proposed and used to predict the growth of different types of tumors. These indexes also show that the proliferation capacity is directly proportional to the invasion capacity. The proposed model assumes: i) only interface cells proliferate and invade the host, and ii) the fractal dimension of tumoral cell patterns, can reproduce the Gompertzian growth law. A mathematical model was obtained to describe the relation between the tissue morphology of cervix carcinoma and both dynamic processes of mitosis and apoptosis, and an expression to quantify the tumor aggressiveness, which in this context is associated with the tumor growth rate. The proposed model was applied to Stage III cervix carcinoma in vivo studies. In this study we found that the apoptosis rate was significantly smaller in the tumor tissues and both the mitosis rate and aggressiveness index decrease with Stage III patient's age. These quantitative results correspond to observed behavior in clinical and genetics studies. Finally, the entropy production rate was determined for avascular tumor growth. The proposed formula relates the fractal dimension of the tumor contour with the quotient between mitosis and apoptosis rate, which can be used to characterize the degree of proliferation of tumor cells. The entropy production rate was determined for fourteen tumor cell lines as a physical function of cancer robustness. The entropy production rate is a hallmark that allows us the possibility of prognosis of tumor proliferation and invasion capacities, key factors to improve cancer therapy.

Fragmentation scaling of percolation clusters in two and three dimensions: Large-cell Monte Carlo RG approach

NASA Astrophysics Data System (ADS)

Cheon, M.; Chang, I.

1999-04-01

The scaling behavior for a binary fragmentation of critical percolation clusters is investigated by a large-cell Monte Carlo real-space renormalization group method in two and three dimensions. We obtain accurate values of critical exponents λ and phi describing the scaling of fragmentation rate and the distribution of fragments' masses produced by a binary fragmentation. Our results for λ and phi show that the fragmentation rate is proportional to the size of mother cluster, and the scaling relation σ = 1 + λ - phi conjectured by Edwards et al. to be valid for all dimensions is satisfied in two and three dimensions, where σ is the crossover exponent of the average cluster number in percolation theory, which excludes the other scaling relations.

On the Hausdorff dimension faithfulness connected with Q_{\\infty} -expansion

NASA Astrophysics Data System (ADS)

Liu, Jia; Zhang, Zhenliang

2017-06-01

In this paper, we show that, the family of all possible unions of finitely many consecutive cylinders of the same rank of a Q∞ -expansion is faithful for the Hausdorff dimension calculations. Applying this result, we give a necessary and sufficient condition for the family of all cylinders of the Q∞ -expansion to be faithful for Hausdorff dimension calculation on the unit interval. This answers an open problem mentioned in Albeverio et al (2016 Math. Nachr. at press (https//:doi.org/10.1002/mana.201500471)).

Key Considerations for the Success of Medical Education Research and Innovation Units in Canada: Unit Director Perceptions

ERIC Educational Resources Information Center

Varpio, Lara; Bidlake, Erin; Humphrey-Murto, Sue; Sutherland, Stephanie; Hamstra, Stanley J.

2014-01-01

Growth in the field of medical education is evidenced by the proliferation of units dedicated to advancing Medical Education Research and Innovation (MERI). While a review of the literature discovered narrative accounts of MERI unit development, we found no systematic examinations of the dimensions of and structures that facilitate the success of…

Neutron diffraction determination of the cell dimensions and thermal expansion of the fluoroperovskite KMgF3 from 293 to 3.6 K

NASA Astrophysics Data System (ADS)

Mitchell, Roger H.; Cranswick, Lachlan M. D.; Swainson, Ian

2006-11-01

The cell dimensions of the fluoroperovskite KMgF3 synthesized by solid state methods have been determined by powder neutron diffraction and Rietveld refinement over the temperature range 293 3.6 K using Pt metal as an internal standard for calibration of the neutron wavelength. These data demonstrate conclusively that cubic Pmoverline{3} m KMgF3 does not undergo any phase transitions to structures of lower symmetry with decreasing temperature. Cell dimensions range from 3.9924(2) Å at 293 K to 3.9800(2) Å at 3.6 K, and are essentially constant within experimental error from 50 to 3.6 K. The thermal expansion data are described using a fourth order polynomial function.

Science in Primary Schools: The Multicultural Dimension.

ERIC Educational Resources Information Center

Peacock, Alan, Ed.

This book brings together a number of perspectives on building a multicultural dimension into science teaching in the United Kingdom. Part 1 gives a variety of practical ideas for use in multi-ethnic and all-white classrooms, heeding the constraints of the National Curriculum. Part 2 examines the underlying rationale for a multicultural approach…

BOX-COUNTING DIMENSION COMPUTED BY α-DENSE CURVES

NASA Astrophysics Data System (ADS)

García, G.; Mora, G.; Redtwitz, D. A.

We introduce a method to reduce to the real case the calculus of the box-counting dimension of subsets of the unit cube In, n > 1. The procedure is based on the existence of special types of α-dense curves (a generalization of the space-filling curves) in In called δ-uniform curves.

Semantic Differential Comparisons of Attributions and Dimensions among Seven Nations.

ERIC Educational Resources Information Center

Chandler, Theodore A.; Spies, Carl J.

The classifications of 11 attributions according to dimensions of locus, stability, controllability, predictability, and globality by participants in 7 countries (China, France, Germany, Hong Kong, Israel, Spain, and the United States) were compared in a cross-cultural study. The attributions were: (1) bias; (2) help; (3) luck; (4) ability; (5)…

The Iron Law of Hierarchy? Institutional Differentiation in UK Higher Education

ERIC Educational Resources Information Center

Croxford, Linda; Raffe, David

2015-01-01

This paper maps the main dimensions of differentiation among institutions and "faculties" (subject areas within institutions) of higher education in the United Kingdom. It does so through a principal components analysis based on the characteristics of applicants and entrants. A single status dimension accounts for a quarter of the…

Development and comparison of multiple regression models to predict bankfull channel dimensions for use in hydrologic models

USDA-ARS?s Scientific Manuscript database

Bankfull hydraulic geometry relationships are used to estimate channel dimensions for streamflow simulation models, which require channel geometry data as input parameters. Often, one nationwide curve is used across the entire United States (U.S.) (e.g., in Soil and Water Assessment Tool), even tho...

Anxiety sensitivity and intolerance of uncertainty as potential risk factors for cyberchondria: A replication and extension examining dimensions of each construct.

PubMed

Fergus, Thomas A

2015-09-15

Preliminary findings suggest that anxiety sensitivity (AS) and intolerance of uncertainty (IU) may confer vulnerability for cyberchondria, defined as repeated internet searches for medical information that exacerbates health anxiety. Prior studies are limited because it remains unclear whether specific AS or IU dimensions differentially relate to certain cyberchondria dimensions. The present study examined associations among AS, IU, and cyberchondria dimensions using a sample of community adults (N = 578) located in the United States. As predicted, physical AS and inhibitory IU were the only AS or IU dimensions to share unique associations with the distress cyberchondria dimension after controlling for the overlap among the AS dimensions, IU dimensions, and health anxiety. Cognitive AS and social AS unexpectedly evidenced unique associations with cyberchondria dimensions. The results are limited by the cross-sectional study design and use of a community, rather than clinical, sample. This study provides evidence that specific AS and IU dimensions may confer vulnerability to certain cyberchondria dimensions. Further clarifying associations among AS, IU, and cyberchondria may lead to improvements in our conceptualization and, ultimately, treatment of cyberchondria. Copyright © 2015 Elsevier B.V. All rights reserved.

An amyloid-forming peptide from the yeast prion Sup35 reveals a dehydrated β-sheet structure for amyloid

PubMed Central

Balbirnie, Melinda; Grothe, Robert; Eisenberg, David S.

2001-01-01

X-ray diffraction and other biophysical tools reveal features of the atomic structure of an amyloid-like crystal. Sup35, a prion-like protein in yeast, forms fibrillar amyloid assemblies intrinsic to its prion function. We have identified a polar peptide from the N-terminal prion-determining domain of Sup35 that exhibits the amyloid properties of full-length Sup35, including cooperative kinetics of aggregation, fibril formation, binding of the dye Congo red, and the characteristic cross-β x-ray diffraction pattern. Microcrystals of this peptide also share the principal properties of the fibrillar amyloid, including a highly stable, β-sheet-rich structure and the binding of Congo red. The x-ray powder pattern of the microcrystals, extending to 0.9-Å resolution, yields the unit cell dimensions of the well-ordered structure. These dimensions restrict possible atomic models of this amyloid-like structure and demonstrate that it forms packed, parallel-stranded β-sheets. The unusually high density of the crystals shows that the packed β-sheets are dehydrated, despite the polar character of the side chains. These results suggest that amyloid is a highly intermolecularly bonded, dehydrated array of densely packed β-sheets. This dry β-sheet could form as Sup35 partially unfolds to expose the peptide, permitting it to hydrogen-bond to the same peptide of other Sup35 molecules. The implication is that amyloid-forming units may be short segments of proteins, exposed for interactions by partial unfolding. PMID:11226247

High-resolution laser spectroscopy of hot Cs and Rb vapor confined in a thin optical cell

NASA Astrophysics Data System (ADS)

Todorov, P.; Krasteva, A.; Vartanyan, T.; Todorov, G.; Sarkisyan, D.; Cartaleva, S.

2018-03-01

We propose a novel use of an optical cell of micrometer thickness filled with Cs vapor in view of studying the collisions between two different alkali atoms of strongly different densities. We demonstrate narrow and good-contrast sub-Doppler resonances at the Rb D2 line for a mean-free-path of the Cs atoms comparable to the optical cell longitudinal dimension; the resonances are completely destroyed when the mean-free-path of the Cs atoms is more than two orders of magnitude shorter than the longitudinal dimension of the thin cell.

Fundamental Dimensions and Essential Elements of Exemplary Local Extension Units

ERIC Educational Resources Information Center

Terry, Bryan D.; Osborne, Edward

2015-01-01

Collaborative efforts between federal, state, and local government agencies enable local Extension units to deliver a high level of educational opportunities to local citizens. These units represent land-grant institutions by delivering non-formal education that aim to address local, regional, and state concerns. The purpose of this study was to…

Absorbed dose evaluation of Auger electron-emitting radionuclides: impact of input decay spectra on dose point kernels and S-values

NASA Astrophysics Data System (ADS)

Falzone, Nadia; Lee, Boon Q.; Fernández-Varea, José M.; Kartsonaki, Christiana; Stuchbery, Andrew E.; Kibédi, Tibor; Vallis, Katherine A.

2017-03-01

The aim of this study was to investigate the impact of decay data provided by the newly developed stochastic atomic relaxation model BrIccEmis on dose point kernels (DPKs - radial dose distribution around a unit point source) and S-values (absorbed dose per unit cumulated activity) of 14 Auger electron (AE) emitting radionuclides, namely 67Ga, 80mBr, 89Zr, 90Nb, 99mTc, 111In, 117mSn, 119Sb, 123I, 124I, 125I, 135La, 195mPt and 201Tl. Radiation spectra were based on the nuclear decay data from the medical internal radiation dose (MIRD) RADTABS program and the BrIccEmis code, assuming both an isolated-atom and condensed-phase approach. DPKs were simulated with the PENELOPE Monte Carlo (MC) code using event-by-event electron and photon transport. S-values for concentric spherical cells of various sizes were derived from these DPKs using appropriate geometric reduction factors. The number of Auger and Coster-Kronig (CK) electrons and x-ray photons released per nuclear decay (yield) from MIRD-RADTABS were consistently higher than those calculated using BrIccEmis. DPKs for the electron spectra from BrIccEmis were considerably different from MIRD-RADTABS in the first few hundred nanometres from a point source where most of the Auger electrons are stopped. S-values were, however, not significantly impacted as the differences in DPKs in the sub-micrometre dimension were quickly diminished in larger dimensions. Overestimation in the total AE energy output by MIRD-RADTABS leads to higher predicted energy deposition by AE emitting radionuclides, especially in the immediate vicinity of the decaying radionuclides. This should be taken into account when MIRD-RADTABS data are used to simulate biological damage at nanoscale dimensions.

The dimensions of crash risk : combination-unit vs. single-unit trucks vs. other vehicles

DOT National Transportation Integrated Search

2013-06-01

This report highlights four metropolitan planning organizations (MPOs) that embrace transportation demand management (TDM) and nonmotorized transportation in an ambitious, conscious, and holistic manner at both regional and local scales. These MPOs, ...

All-angle negative refraction and active flat lensing of ultraviolet light.

PubMed

Xu, Ting; Agrawal, Amit; Abashin, Maxim; Chau, Kenneth J; Lezec, Henri J

2013-05-23

Decades ago, Veselago predicted that a material with simultaneously negative electric and magnetic polarization responses would yield a 'left-handed' medium in which light propagates with opposite phase and energy velocities--a condition described by a negative refractive index. He proposed that a flat slab of left-handed material possessing an isotropic refractive index of -1 could act like an imaging lens in free space. Left-handed materials do not occur naturally, and it has only recently become possible to achieve a left-handed response using metamaterials, that is, electromagnetic structures engineered on subwavelength scales to elicit tailored polarization responses. So far, left-handed responses have typically been implemented using resonant metamaterials composed of periodic arrays of unit cells containing inductive-capacitive resonators and conductive wires. Negative refractive indices that are isotropic in two or three dimensions at microwave frequencies have been achieved in resonant metamaterials with centimetre-scale features. Scaling the left-handed response to higher frequencies, such as infrared or visible, has been done by shrinking critical dimensions to submicrometre scales by means of top-down nanofabrication. This miniaturization has, however, so far been achieved at the cost of reduced unit-cell symmetry, yielding a refractive index that is negative along only one axis. Moreover, lithographic scaling limits have so far precluded the fabrication of resonant metamaterials with left-handed responses at frequencies beyond the visible. Here we report the experimental implementation of a bulk metamaterial with a left-handed response to ultraviolet light. The structure, based on stacked plasmonic waveguides, yields an omnidirectional left-handed response for transverse magnetic polarization characterized by a negative refractive index. By engineering the structure to have a refractive index close to -1 over a broad angular range, we achieve Veselago flat lensing, in free space, of arbitrarily shaped, two-dimensional objects beyond the near field. We further demonstrate active, all-optical modulation of the image transferred by the flat lens.

The effects of loading on the preload and dimensions of the abutment screw for a 3-unit cantilever-fixed prosthesis design.

PubMed

Setia, Gaurav; Yousef, Hoda; Ehrenberg, David; Luke, Allyn; Weiner, Saul

2013-08-01

The purpose of this study was to use an in vitro model system to compare the effects on the screw torque and screw dimensions within 2 commercially available implant systems from occlusal loading on a cantilevered-fixed partial denture. Cantilevered implant-supported 3-unit prostheses with 2 premolar abutments and 1 premolar pontic (7.3 mm in length) were made on resin casts containing 2 implant analogs for 2 implant systems: BioLok Silhouette Tapered Implant System (Birmingham, AL) and Zimmer Tapered Screw-Vent Implant System (Carlsbad, CA) with 10 samples in each group. Each sample was loaded with either of 2 protocols: (1) a load of 50 N on the cantilevered pontic unit and (2) a loading of 150 N on all 3 units. The outcome measures were (1) changes in residual torque of the abutment screws and (2) changes in screw dimension. The BioLok Silhouette Tapered Implant group demonstrated slight but statistically significant torque loss 18.8% to 28.5% in both abutment screws for both protocols, P ≤ 0.05, without any changes in screw dimension. In the Zimmer Tapered Screw-Vent Implant group, there was a significant elongation of the abutment screws and a markedly significant 44.4%, (P ≤ 0.01) loss in torque in the mesial screw and a 28.5%, (P ≤ 0.05) loss in torque in the distal screw when the cantilever alone was loaded. Differences in screw design influence the maintenance of preload and distortion of the shank. The influence of the interface design, namely an internal hex of 1 mm versus an external hex did not influence the preload. Cantilevered prostheses can cause loss of torque and dimensional changes in abutment screws.

Image of the United States as a travel destination: a case study of United Kingdom college students

Treesearch

Sung Hee Park; Pavlina Latkova; Sarah Nicholls

2007-01-01

The youth travel market is a major growth segment of international tourism. The purpose of this study was to explore the travel behaviors and perceptions of United Kingdom college students with regards to the United States as a travel destination. Two objectives were formulated, to determine whether image dimensions differed based on (1) travel behavior, and (2) socio-...

Study of plasma meniscus and beam halo in negative ion sources using three dimension in real space and three dimension in velocity space particle in cell model

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

Nishioka, S., E-mail: nishioka@ppl.appi.keio.ac.jp; Goto, I.; Hatayama, A.

2014-02-15

Our previous study by two dimension in real space and three dimension in velocity space-particle in cell model shows that the curvature of the plasma meniscus causes the beam halo in the negative ion sources. The negative ions extracted from the periphery of the meniscus are over-focused in the extractor due to the electrostatic lens effect, and consequently become the beam halo. The purpose of this study is to verify this mechanism with the full 3D model. It is shown that the above mechanism is essentially unchanged even in the 3D model, while the fraction of the beam halo ismore » significantly reduced to 6%. This value reasonably agrees with the experimental result.« less

Crystallization and preliminary X-ray diffraction analysis of restriction endonuclease EcoRII

NASA Technical Reports Server (NTRS)

Karpova, E. A.; Meehan, E.; Pusey, M. L.; Chen, L.

1999-01-01

Crystals of the restriction endonuclease EcoRII have been obtained by the vapor-diffusion technique in the presence of ammonium sulfate or polyethylene glycol. The best crystals were grown with ammonium sulfate as a precipitant. Crystals with dimensions of up to 0.6 x 0. 6 x 0.6 mm have been observed. The crystals diffract to about 4.0 A resolution at a cryo-temperature of 100 K using a rotating-anode X-ray source and a Rigaku R-AXIS IV imaging-plate detector. The space group has been determined to be either I23 or I2(1)3, with unit-cell parameters a = b = c = 160.3 A, alpha = beta = gamma = 90 degrees. The crystal asymmetric unit contains two protein molecules, and self-rotation function analysis shows a pseudo-twofold symmetry relating the two monomers. Attempts to improve the resolution of crystal diffraction and to search for heavy-atom derivatives are under way.

Mnemonic neuronal activity in somatosensory cortex.

PubMed Central

Zhou, Y D; Fuster, J M

1996-01-01

Single-unit activity was recorded from the hand areas of the somatosensory cortex of monkeys trained to perform a haptic delayed matching to sample task with objects of identical dimensions but different surface features. During the memory retention period of the task (delay), many units showed sustained firing frequency change, either excitation or inhibition. In some cases, firing during that period was significantly higher after one sample object than after another. These observations indicate the participation of somatosensory neurons not only in the perception but in the short-term memory of tactile stimuli. Neurons most directly implicated in tactile memory are (i) those with object-selective delay activity, (ii) those with nondifferential delay activity but without activity related to preparation for movement, and (iii) those with delay activity in the haptic-haptic delayed matching task but no such activity in a control visuo-haptic delayed matching task. The results indicate that cells in early stages of cortical somatosensory processing participate in haptic short-term memory. PMID:8927629

The morphology and classification of α ganglion cells in the rat retinae: a fractal analysis study.

PubMed

Jelinek, Herbert F; Ristanović, Dušan; Milošević, Nebojša T

2011-09-30

Rat retinal ganglion cells have been proposed to consist of a varying number of subtypes. Dendritic morphology is an essential aspect of classification and a necessary step toward understanding structure-function relationships of retinal ganglion cells. This study aimed at using a heuristic classification procedure in combination with the box-counting analysis to classify the alpha ganglion cells in the rat retinae based on the dendritic branching pattern and to investigate morphological changes with retinal eccentricity. The cells could be divided into two groups: cells with simple dendritic pattern (box dimension lower than 1.390) and cells with complex dendritic pattern (box dimension higher than 1.390) according to their dendritic branching pattern complexity. Both were further divided into two subtypes due to the stratification within the inner plexiform layer. In the present study we have shown that the alpha rat RCGs can be classified further by their dendritic branching complexity and thus extend those of previous reports that fractal analysis can be successfully used in neuronal classification, particularly that the fractal dimension represents a robust and sensitive tool for the classification of retinal ganglion cells. A hypothesis of possible functional significance of our classification scheme is also discussed. Copyright © 2011 Elsevier B.V. All rights reserved.

Liberal red blood cell transfusions impair quality of life after cardiac surgery.

PubMed

González-Pérez, A; Al-Sibai, J Z; Álvarez-Fernández, P; Martínez-Camblor, P; Argüello-Junquera, M; García-Gala, J M; Martínez-Revuelta, E; Silva, J; Morís, C; Albaiceta, G M

2018-03-12

The optimal blood management after cardiac surgery remains controversial. Moreover, blood transfusions may have an impact on long-term outcomes. The aim of this study is to characterize the impact of liberal red blood cell transfusions on Health-Related Quality of life (HRQoL) after cardiac surgery. We studied a cohort of 205 consecutive patients after ICU discharge. Baseline characteristics and clinical data were recorded, and HRQoL was assessed using the EuroQoL-5D instrument, applied 6 months after ICU discharge. A specific question regarding the improvement in the quality of life after the surgical intervention was added to the HRQoL questionnaire. Risk factors related to impaired quality of life were identified using univariate comparisons and multivariate regression techniques. The median (interquartile range, IQR) of transfused red blood cells was 3 (1-4). Among 205 patients, 178 were studied 6 months after discharge. Impairment in at least one dimension of the EuroQoL-5D questionnaire was observed in 120 patients, with an overall score of 0.8 (IQR 0.61-1). The number of red blood cell transfusions was related to an impaired HRQoL (OR 1.17 per additional unit, 95% confidence interval 1.03-1.36, p=0.03), a trend to lower visual analog scale score (coefficient -0.75 per additional unit, 95% confidence interval -1.61 to 0.1, p=0.09) and an absence of improvement in HRQoL after surgery compared to the previous status (OR 1.13, 95% confidence interval 1.03-1.25, p=0.01). Liberal red blood cell transfusions increase the risk of impaired HRQoL after cardiac surgery. Copyright © 2018 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

Organizational climate configurations: relationships to collective attitudes, customer satisfaction, and financial performance.

PubMed

Schulte, Mathis; Ostroff, Cheri; Shmulyian, Svetlana; Kinicki, Angelo

2009-05-01

Research on organizational climate has tended to focus on independent dimensions of climate rather than studying the total social context as configurations of multiple climate dimensions. The authors examined relationships between configurations of unit-level climate dimensions and organizational outcomes. Three profile characteristics represented climate configurations: (1) elevation, or the mean score across climate dimensions; (2) variability, or the extent to which scores across dimensions vary; and (3) shape, or the pattern of the dimensions. Across 2 studies (1,120 employees in 120 bank branches and 4,317 employees in 86 food distribution stores), results indicated that elevation was related to collective employee attitudes and service perceptions, while shape was related to customer satisfaction and financial performance. With respect to profile variability, results were mixed. The discussion focuses on future directions for taking a configural approach to organizational climate. (c) 2009 APA, all rights reserved.

Use of Direct and Indirect Estimates of Crown Dimensions to Predict One Seed Juniper Woody Biomass Yield for Alternative Energy Uses

USDA-ARS?s Scientific Manuscript database

Throughout the western United States there is increased interest in utilizing woodland biomass as an alternative energy source. We conducted a pilot study to predict one seed juniper (Juniperus monosperma) chip yield from tree-crown dimensions measured on the ground or derived from Very Large Scale ...

Rhythm in Number: Exploring the Affective, Social and Mathematical Dimensions of Using "TouchCounts"

ERIC Educational Resources Information Center

Sinclair, Nathalie; Chorney, Sean; Rodney, Sheree

2016-01-01

In this paper, we investigate the mathematical, social and affective nature of children's engagement with "TouchCounts," a multitouch application for counting and doing arithmetic. In order to study these dimensions of engagement in a way that recognizes their fundamental intertwinement, we use rhythm as a primary unit of analysis.…

Fractionated analysis of paired-electrode nerve recordings.

PubMed

Fiore, Lorenzo; Lorenzetti, Walter; Ratti, Giovannino; Geppetti, Laura

2003-12-30

Multi-unit activity recorded from two electrodes positioned at a distance on a nerve may be analysed by cross-correlation, but units similar in direction and velocity of propagation cannot be distinguished and separately evaluated by this method. To overcome this limit, we added two features, represented by the impulse amplitudes of the paired recordings, to the dimension given by the impulse delay. The analysis was fractionated according to the new dimensions. In experimental recordings from the locomotor appendage of the lobster Homarus americanus, the fractionated analysis proved capable of identifying the contributions of single active units, even if these were superimposed and indiscernible in the global cross-correlation histogram. Up to 5 motor and 10 sensory units could be identified. The shape of the paired impulses was evaluated by an averaging procedure. Analogous evaluations on simulated recordings made it possible to estimate the influences exerted on performance by variations in noise level and in the number and firing rate of active units. The global signal could be resolved into single units even under the worst conditions. Accuracy in evaluating the amount of unit activity varied, exceeding 90% in about half of the cases tested; a similar performance was attained by evaluation of the impulse shapes.

Cameron's Dimensions of Effectiveness in Higher Education in the U.K.: A Cross-Cultural Comparison.

ERIC Educational Resources Information Center

Lysons, Art; Hatherly, David

1992-01-01

An approach to organizational effectiveness in higher education developed in the United States was applied to institutions in the United Kingdom and Australia to establish a basis for policy and organizational analysis. Higher reliability was found for the United Kingdom than for Australia, apparently related to cultural differences regarding…

A Comparative Study of Child Temperament and Parenting in Beijing, China and the Western United States

ERIC Educational Resources Information Center

Porter, Christian L.; Hart, Craig H.; Yang, Chongming; Robinson, Clyde C.; Olsen, Susanne Frost; Zeng, Qing; Olsen, Joseph A.; Jin, Shenghua

2005-01-01

The purpose of this investigation was to examine comparable dimensions and linkages between child temperament and parenting styles with samples from Beijing, China and the western United States. Participants included 404 mothers and fathers from Beijing, China and 325 mothers and fathers from the western United States. Both mothers and fathers…

A geometric projection method for designing three-dimensional open lattices with inverse homogenization

DOE PAGES

Watts, Seth; Tortorelli, Daniel A.

2017-04-13

Topology optimization is a methodology for assigning material or void to each point in a design domain in a way that extremizes some objective function, such as the compliance of a structure under given loads, subject to various imposed constraints, such as an upper bound on the mass of the structure. Geometry projection is a means to parameterize the topology optimization problem, by describing the design in a way that is independent of the mesh used for analysis of the design's performance; it results in many fewer design parameters, necessarily resolves the ill-posed nature of the topology optimization problem, andmore » provides sharp descriptions of the material interfaces. We extend previous geometric projection work to 3 dimensions and design unit cells for lattice materials using inverse homogenization. We perform a sensitivity analysis of the geometric projection and show it has smooth derivatives, making it suitable for use with gradient-based optimization algorithms. The technique is demonstrated by designing unit cells comprised of a single constituent material plus void space to obtain light, stiff materials with cubic and isotropic material symmetry. Here, we also design a single-constituent isotropic material with negative Poisson's ratio and a light, stiff material comprised of 2 constituent solids plus void space.« less

A geometric projection method for designing three-dimensional open lattices with inverse homogenization

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

Watts, Seth; Tortorelli, Daniel A.

Topology optimization is a methodology for assigning material or void to each point in a design domain in a way that extremizes some objective function, such as the compliance of a structure under given loads, subject to various imposed constraints, such as an upper bound on the mass of the structure. Geometry projection is a means to parameterize the topology optimization problem, by describing the design in a way that is independent of the mesh used for analysis of the design's performance; it results in many fewer design parameters, necessarily resolves the ill-posed nature of the topology optimization problem, andmore » provides sharp descriptions of the material interfaces. We extend previous geometric projection work to 3 dimensions and design unit cells for lattice materials using inverse homogenization. We perform a sensitivity analysis of the geometric projection and show it has smooth derivatives, making it suitable for use with gradient-based optimization algorithms. The technique is demonstrated by designing unit cells comprised of a single constituent material plus void space to obtain light, stiff materials with cubic and isotropic material symmetry. Here, we also design a single-constituent isotropic material with negative Poisson's ratio and a light, stiff material comprised of 2 constituent solids plus void space.« less

Ba0.06(Na,Bi)0.94Ti1-x(Ni1/3Nb2/3)xO3 ceramics: X-ray diffraction and infrared spectroscopy studies

NASA Astrophysics Data System (ADS)

Mishra, R. K.; Prasad, Ashutosh; Chandra, K. P.; Prasad, K.

2018-05-01

Non-lead ceramic samples of Ba0.06(Na0.5Bi0.5)0.94Ti1-x(Ni1/3Nb2/3)xO3; 0 ≤ x ≤ 1.0 were prepared by standard high temperature ceramic synthesis method. Rietveld refinements of X-ray diffraction data of these ceramics were carried out using FullProf software and determined their crystal symmetry, space group and unit cell dimensions. Rietveld refinement revealed that Ba0.06(Na0.5Bi0.5)0.94TiO3 has a monoclinic structure with space group P4/m while B0.06(Na0.5Bi0.5)0.94(Ni1/3Nb2/3)O3 has tetragonal (pseudo-cubic) structure with space group P4/mmm. Partial replacement of Ti4+ ion by pseudo-cation (Ni1/33 +Nb2/3 5 +) 4 + resulted in the change of unit cell structure from monoclinic to tetragonal. SEM studies were carried out in order to access the quality of the prepared ceramics which showed a change in grain sizes with the increase of (Ni1/33 +Nb2/3 5 +) 4 + content. FTIR spectra confirmed the formation of perovskite type solid solutions.

Human 17β-hydroxysteroid dehydrogenase-ligand complexes: crystals of different space groups with various cations and combined seeding and co-crystallization

NASA Astrophysics Data System (ADS)

Zhu, D.-W.; Han, Q.; Qiu, W.; Campbell, R. L.; Xie, B.-X.; Azzi, A.; Lin, S.-X.

1999-01-01

Human estrogenic 17β-hydroxysteroid dehydrogenase (17β-HSD1) is responsible for the synthesis of active estrogens that stimulate the proliferation of breast cancer cells. The enzyme has been crystallized using a Mg 2+/PEG (3500)/β-octyl glucoside system [Zhu et al., J. Mol. Biol. 234 (1993) 242]. The space group of these crystals is C2. Here we report that cations can affect 17β-HSD1 crystallization significantly. In the presence of Mn 2+ instead of Mg 2+, crystals have been obtained in the same space group with similar unit cell dimensions. In the presence of Li + and Na + instead of Mg 2+, the space group has been changed to P2 12 12 1. A whole data set for a crystal of 17ß-HSD1 complex with progesterone grown in the presence of Li + has been collected to 1.95 Å resolution with a synchrotron source. The cell dimensions are a=41.91 Å, b=108.21 Å, c=117.00 Å. The structure has been preliminarily determined by molecular replacement, yielding important information on crystal packing in the presence of different cations. In order to further understand the structure-function relationship of 17β-HSD1, enzyme complexes with several ligands have been crystallized. As the steroids have very low aqueous solubility, we used a combined method of seeding and co-crystallization to obtain crystals of 17β-HSD1 complexed with various ligands. This method provides ideal conditions for growing complex crystals, with ligands such as 20α-hydroxysteroid progesterone, testosterone and 17β-methyl-estradiol-NADP +. Several complex structures have been determined with reliable electronic density of the bound ligands.

Reference ranges of kidney dimensions in term newborns: sonographic measurements.

PubMed

Erdemir, Aydin; Kahramaner, Zelal; Arik, Bilal; Bilgili, Gokmen; Tekin, Mehmet; Genc, Yeliz

2014-11-01

Ultrasonographic measurement of kidney dimensions is important in evaluation of renal disease during the neonatal period, when renal abnormalities are common and renal size rapidly changes with age. To determine the reference ranges of kidney dimensions in newborns and to provide a reference chart for daily practice. In this prospective study, kidney dimensions were evaluated in 385 healthy newborns with a gestational age ≥37 weeks. Each neonate seen at an obstetrics clinic and neonatal intensive care unit was examined with sonography within the first week of life. Relationships of all dimensions with gender, gestational age, height and weight were statistically analyzed. All dimensions of the kidneys were smaller in girls than in boys (P < 0.05). The dimensions of the left kidney were larger than those in the right kidney in both genders (P < 0.01). Longitudinal and anteroposterior dimensions of the right and left kidneys showed no correlation with the gestational age in either gender. The dimensions correlated with the height in boys (P < 0.01), while no correlation was seen between the dimensions and height in girls (P < 0.05). Weight had the best correlation with all dimensions in both genders. The reference values of kidney lengths and diagrams from this study may be useful in the sonographic evaluation of kidneys in newborns.

New methods for indexing multi-lattice diffraction data

PubMed Central

Gildea, Richard J.; Waterman, David G.; Parkhurst, James M.; Axford, Danny; Sutton, Geoff; Stuart, David I.; Sauter, Nicholas K.; Evans, Gwyndaf; Winter, Graeme

2014-01-01

A new indexing method is presented which is capable of indexing multiple crystal lattices from narrow wedges of diffraction data. The method takes advantage of a simplification of Fourier transform-based methods that is applicable when the unit-cell dimensions are known a priori. The efficacy of this method is demonstrated with both semi-synthetic multi-lattice data and real multi-lattice data recorded from crystals of ∼1 µm in size, where it is shown that up to six lattices can be successfully indexed and subsequently integrated from a 1° wedge of data. Analysis is presented which shows that improvements in data-quality indicators can be obtained through accurate identification and rejection of overlapping reflections prior to scaling. PMID:25286849

New methods for indexing multi-lattice diffraction data.

PubMed

Gildea, Richard J; Waterman, David G; Parkhurst, James M; Axford, Danny; Sutton, Geoff; Stuart, David I; Sauter, Nicholas K; Evans, Gwyndaf; Winter, Graeme

2014-10-01

A new indexing method is presented which is capable of indexing multiple crystal lattices from narrow wedges of diffraction data. The method takes advantage of a simplification of Fourier transform-based methods that is applicable when the unit-cell dimensions are known a priori. The efficacy of this method is demonstrated with both semi-synthetic multi-lattice data and real multi-lattice data recorded from crystals of ∼1 µm in size, where it is shown that up to six lattices can be successfully indexed and subsequently integrated from a 1° wedge of data. Analysis is presented which shows that improvements in data-quality indicators can be obtained through accurate identification and rejection of overlapping reflections prior to scaling.

New methods for indexing multi-lattice diffraction data

DOE PAGES

Gildea, Richard J.; Waterman, David G.; Parkhurst, James M.; ...

2014-09-27

A new indexing method is presented which is capable of indexing multiple crystal lattices from narrow wedges of diffraction data. The method takes advantage of a simplification of Fourier transform-based methods that is applicable when the unit-cell dimensions are known a priori. The efficacy of this method is demonstrated with both semi-synthetic multi-lattice data and real multi-lattice data recorded from crystals of ~1 µm in size, where it is shown that up to six lattices can be successfully indexed and subsequently integrated from a 1° wedge of data. Analysis is presented which shows that improvements in data-quality indicators can bemore » obtained through accurate identification and rejection of overlapping reflections prior to scaling.« less

Study of a Flexible Low Profile Tunable Dipole Antenna Using Barium Strontium Titanate Varactors

NASA Technical Reports Server (NTRS)

Cure, David; Weller, Thomas; Miranda, Felix A.

2014-01-01

In this paper a flexible low profile dipole antenna using a frequency selective surface (FSS) with interdigital barium strontium titanate (BST) varactor-tuned unit cells is presented. The varactor chips were placed only along one dimension of the FSS to avoid the use of vias and simplify the DC bias network. The antenna uses overlapping metallic plates that resemble fish scales as a ground plane to improve the flexibility of the multi-material stack structure. The measured data of the antenna demonstrate tunability from 2.42 GHz to 2.66 GHz and 1.3 dB gain drop when using overlapping metallic plates instead of continuous ground plane. The total antenna thickness is approximately lambda/24.

Tree-shaped fractal meta-surface with left-handed characteristics for absorption application

NASA Astrophysics Data System (ADS)

Faruque, M. R. I.; Hasan, M. M.; Islam, M. T.

2018-02-01

A tri-band fractal meta-surface absorber composed of metallic branches of a tree connected with a straight metal strip has been presented in this paper for high absorption application. The proposed tree-shaped structure shows resonance in C-, X-, and Ku-bands and left-handed characteristics in 14.15 GHz. The dimension of the tree-shaped meta-surface single unit cell structure is 9 × 9 mm2 and the effective medium ratio is 5.50. In addition, the designed absorber structure shows absorption above 84%, whereas the absorber structure printed on epoxy resin fiber substrate material. The FIT-based CST-MWS has been utilized for the design, simulation, and analysis purposes. Fabrication is also done for the experimental validation.

Pumping power considerations in the designs of NASA-Redox flow cells

NASA Technical Reports Server (NTRS)

Hoberecht, M. A.

1981-01-01

Pressure drop data for six different cell geometries of various flow port, manifold, and cavity dimensions are presented. The redox/energy/storage system uses two fully soluble redox couples as anode and cathode fluids. Both fluids are pumped through a redox cell, or stack of cells, where the electrochemical reactions take place at porous carbon felt electrodes. Pressure drop losses are therefore associated with this system due to the continuous flow of reactant solutions. The exact pressure drop within a redox flow cell is directly dependent on the flow rate as well as the various cell dimensions. Pumping power requirements for a specific set of cell operating conditions are found for various cell geometries once the flow rate and pressure drop are determined. These pumping power requirements contribute to the overall system parasitic energy losses which must be minimized, the choice of cell geometry becomes critical.

Precise Dimensions; A history of units from 1791-2018

NASA Astrophysics Data System (ADS)

Cooper, Malcolm; Grozier, Jim

2017-11-01

Units are the foundation for all measurement of the natural world, and from which standard, our understanding develops. This book, stemming from a conference on the history of units organised by the editors, provides a detailed and discursive examination of the history of units within physics, in advance of the proposed redefinition of the SI base units at the General Conference on Weights and Measures in 2018. It features contributions from leading researchers in metrology and history.

Viral epidemics in a cell culture: novel high resolution data and their interpretation by a percolation theory based model.

PubMed

Gönci, Balázs; Németh, Valéria; Balogh, Emeric; Szabó, Bálint; Dénes, Ádám; Környei, Zsuzsanna; Vicsek, Tamás

2010-12-20

Because of its relevance to everyday life, the spreading of viral infections has been of central interest in a variety of scientific communities involved in fighting, preventing and theoretically interpreting epidemic processes. Recent large scale observations have resulted in major discoveries concerning the overall features of the spreading process in systems with highly mobile susceptible units, but virtually no data are available about observations of infection spreading for a very large number of immobile units. Here we present the first detailed quantitative documentation of percolation-type viral epidemics in a highly reproducible in vitro system consisting of tens of thousands of virtually motionless cells. We use a confluent astroglial monolayer in a Petri dish and induce productive infection in a limited number of cells with a genetically modified herpesvirus strain. This approach allows extreme high resolution tracking of the spatio-temporal development of the epidemic. We show that a simple model is capable of reproducing the basic features of our observations, i.e., the observed behaviour is likely to be applicable to many different kinds of systems. Statistical physics inspired approaches to our data, such as fractal dimension of the infected clusters as well as their size distribution, seem to fit into a percolation theory based interpretation. We suggest that our observations may be used to model epidemics in more complex systems, which are difficult to study in isolation.

Viral Epidemics in a Cell Culture: Novel High Resolution Data and Their Interpretation by a Percolation Theory Based Model

PubMed Central

Gönci, Balázs; Németh, Valéria; Balogh, Emeric; Szabó, Bálint; Dénes, Ádám; Környei, Zsuzsanna; Vicsek, Tamás

2010-01-01

Because of its relevance to everyday life, the spreading of viral infections has been of central interest in a variety of scientific communities involved in fighting, preventing and theoretically interpreting epidemic processes. Recent large scale observations have resulted in major discoveries concerning the overall features of the spreading process in systems with highly mobile susceptible units, but virtually no data are available about observations of infection spreading for a very large number of immobile units. Here we present the first detailed quantitative documentation of percolation-type viral epidemics in a highly reproducible in vitro system consisting of tens of thousands of virtually motionless cells. We use a confluent astroglial monolayer in a Petri dish and induce productive infection in a limited number of cells with a genetically modified herpesvirus strain. This approach allows extreme high resolution tracking of the spatio-temporal development of the epidemic. We show that a simple model is capable of reproducing the basic features of our observations, i.e., the observed behaviour is likely to be applicable to many different kinds of systems. Statistical physics inspired approaches to our data, such as fractal dimension of the infected clusters as well as their size distribution, seem to fit into a percolation theory based interpretation. We suggest that our observations may be used to model epidemics in more complex systems, which are difficult to study in isolation. PMID:21187920

Nuclear patterns of human breast cancer cells during apoptosis: characterisation by fractal dimension and co-occurrence matrix statistics.

PubMed

Losa, Gabriele A; Castelli, Christian

2005-11-01

An analytical strategy combining fractal geometry and grey-level co-occurrence matrix (GLCM) statistics was devised to investigate ultrastructural changes in oestrogen-insensitive SK-BR3 human breast cancer cells undergoing apoptosis in vitro. Apoptosis was induced by 1 microM calcimycin (A23187 Ca(2+) ionophore) and assessed by measuring conventional cellular parameters during the culture period. SK-BR3 cells entered the early stage of apoptosis within 24 h of treatment with calcimycin, which induced detectable changes in nuclear components, as documented by increased values of most GLCM parameters and by the general reduction of the fractal dimensions. In these affected cells, morphonuclear traits were accompanied by the reduction of distinct gangliosides and loss of unidentifiable glycolipid molecules at the cell surface. All these changes were shown to be involved in apoptosis before the detection of conventional markers, which were only measurable during the active phases of apoptotic cell death. In overtly apoptotic cells treated with 1 microM calcimycin for 72 h, most nuclear components underwent dramatic ultrastructural changes, including marginalisation and condensation of chromatin, as reflected in a significant reduction of their fractal dimensions. Hence, both fractal and GLCM analyses confirm that the morphological reorganisation of nuclei, attributable to a loss of structural complexity, occurs early in apoptosis.

New Models for Predicting Diameter at Breast Height from Stump Dimensions

Treesearch

James A. Westfall

2010-01-01

Models to predict dbh from stump dimensions are presented for 18 species groups. Data used to fit the models were collected across thirteen states in the northeastern United States. Primarily because of the presence of multiple measurements from each tree, a mixed-effects modeling approach was used to account for the lack of independence among observations. The...

Multiple Dimensions to the Application for the Effectiveness of Team Building in ROTC

ERIC Educational Resources Information Center

Chen, Yin-Che; Chen, Yun-Chi; Tsao, Ya-Lun

2009-01-01

Team building has been given increasing attention and applied in diverse disciplines in recent years. The purpose of this study was to determine the multiple dimensions to the application for the effectiveness of team building in the military units such as ROTC since not many existing literature has investigated this in such an expectedly high…

Dimensions of the Community College: International, Intercultural, and Multicultural Perspectives. Garland Studies in Higher Education, Volume 6. Garland Reference Library of Social Science, Volume 1075.

ERIC Educational Resources Information Center

Raby, Rosalind Latiner, Ed.; Tarrow, Norma, Ed.

This two-part monograph provides a theoretical and practical analyses of intercultural and multicultural education programs. The first part describes inter- and multicultural educational programs in the United States and Canada and includes the following eight chapters: "International, Intercultural, and Multicultural Dimensions of Community…

Participating on Equal Terms? The Gender Dimensions of Direct Participation in Organisational Change: Findings from the EPOC Survey.

ERIC Educational Resources Information Center

Schnabel, Annette; Webster, Juliet

The gender dimensions of direct participation in organizational change were examined in a survey of general managers at 32,582 workplaces in the following European countries: Denmark, France, Germany, Ireland, Italy, the Netherlands, Portugal, Spain, Sweden, and the United Kingdom. Responses were received from 5,786 managers (response rate,…

Association of Safety Culture with Surgical Site Infection Outcomes.

PubMed

Fan, Caleb J; Pawlik, Timothy M; Daniels, Tania; Vernon, Nora; Banks, Katie; Westby, Peggy; Wick, Elizabeth C; Sexton, J Bryan; Makary, Martin A

2016-02-01

Hospital workplace culture may have an impact on surgical outcomes; however, this association has not been established. We designed a study to evaluate the association between safety culture and surgical site infection (SSI). Using the Hospital Survey on Patient Safety Culture and National Healthcare Safety Network definitions, we measured 12 dimensions of safety culture and colon SSI rates, respectively, in the surgical units of Minnesota community hospitals. A Pearson's r correlation was calculated for each of 12 dimensions of surgical unit safety culture and SSI rate and then adjusted for surgical volume and American Society of Anesthesiologists (ASA) classification. Seven hospitals participated in the study, with a mean survey response rate of 43%. The SSI rates ranged from 0% to 30%, and surgical unit safety culture scores ranged from 16 to 92 on a scale of 0 to 100. Ten dimensions of surgical unit safety culture were associated with colon SSI rates: teamwork across units (r = -0.96; 95% CI [-0.76, -0.99]), organizational learning (r = -0.95; 95% CI [-0.71, -0.99]), feedback and communication about error (r = -0.92; 95% CI [-0.56, -0.99]), overall perceptions of safety (r = -0.90; 95% CI [-0.45, -0.99]), management support for patient safety (r = -0.90; 95% CI [-0.44, -0.98]), teamwork within units (r = -0.88; 95% CI [-0.38, -0.98]), communication openness (r = -0.85; 95% CI [-0.26, -0.98]), supervisor/manager expectations and actions promoting safety (r = -0.85; 95% CI [-0.25, -0.98]), non-punitive response to error (r = -0.78; 95% CI [-0.07, -0.97]), and frequency of events reported (r = -0.76; 95% CI [-0.01, -0.96]). After adjusting for surgical volume and ASA classification, 9 of 12 dimensions of surgical unit safety culture were significantly associated with lower colon SSI rates. These data suggest an important role for positive safety and teamwork culture and engaged hospital management in producing high-quality surgical outcomes. Copyright © 2016. Published by Elsevier Inc.

Speciation, Sources and Bioavailability of Copper and Zinc in DoD-Impacted Harbors and Estuaries

DTIC Science & Technology

2007-03-01

Bioavailability Studies Summary: We developed robust trace metal bioassays using two species of marine phytoplankton (Thalassiosira weissflogi, and Emiliania ...centrales diatom. Cells are 10-12 µm in dimension, and (2) Emiliania huxleyi, a prymnesiophyte with CaCO3 coccoliths. Cells are 4-8 µm in dimension...Thalassiosira weissflogi Centrales Diatom with SiO2 frustules. 10-12 µm. Widely Distributed Emiliania huxleyi Prymnesiophyte with CaCO3 coccoliths

Kinetics of biochemical sensing by single cells and populations of cells

NASA Astrophysics Data System (ADS)

Saakian, David B.

2017-10-01

We investigate the collective stationary sensing using N communicative cells, which involves surface receptors, diffusive signaling molecules, and cell-cell communication messengers. We restrict the scenarios to the signal-to-noise ratios (SNRs) for both strong communication and extrinsic noise only. We modified a previous model [Bialek and Setayeshgar, Proc. Natl. Acad. Sci. USA 102, 10040 (2005), 10.1073/pnas.0504321102] to eliminate the singularities in the fluctuation correlations by considering a uniform receptor distribution over the surface of each cell with a finite radius a . The modified model enables a simple and rigorous mathematical treatment of the collective sensing phenomenon. We then derive the scaling of the SNR for both juxtacrine and autocrine cases in all dimensions. For the optimal locations of the cells in the autocrine case, we find identical scaling for both two and three dimensions.

Estimation of Fractal Dimension in Differential Diagnosis of Pigmented Skin Lesions

NASA Astrophysics Data System (ADS)

Aralica, Gorana; Milošević, Danko; Konjevoda, Paško; Seiwerth, Sven; Štambuk, Nikola

Medical differential diagnosis is a method of identifying the presence of a particular entity (disease) within a set of multiple possible alternatives. The significant problem in dermatology and pathology is the differential diagnosis of malignant melanoma and other pigmented skin lesions, especially of dysplastic nevi. Malignant melanoma is the most malignant skin neoplasma, with increasing incidence in various parts of the world. It is hoped that the methods of quantitative pathology, i.e. morphometry, can help objectification of the diagnostic process, since early discovery of melanoma results in 10-year survival rate of 90%. The aim of the study was to use fractal dimension calculated from the perimeter-area relation of the cell nuclei as a tool for the differential diagnosis of pigmented skin lesions. We analyzed hemalaun-eosin stained pathohistological slides of pigmented skin lesions: intradermal naevi (n = 45), dysplastic naevi (n = 47), and malignant melanoma (n = 50). It was found that fractal dimension of malignant melanoma cell nuclei differs significantly from the intradermal and dysplastic naevi (p ≤ 0. 001, Steel-Dwass Multiple Comparison Test). Additionaly, ROC analysis confirmed the value of fractal dimension based evaluation. It is suggested that the estimation of fractal dimension from the perimeter-area relation of the cell nuclei may be a potentially useful morphometric parameter in the medical differential diagnosis of pigmented skin lesions.

Current advances in synchrotron radiation instrumentation for MX experiments

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

Owen, Robin L.; Juanhuix, Jordi; Fuchs, Martin

2016-07-01

Following pioneering work 40 years ago, synchrotron beamlines dedicated to macromolecular crystallography (MX) have improved in almost every aspect as instrumentation has evolved. Beam sizes and crystal dimensions are now on the single micron scale while data can be collected from proteins with molecular weights over 10 MDa and from crystals with unit cell dimensions over 1000 Å. Furthermore it is possible to collect a complete data set in seconds, and obtain the resulting structure in minutes. The impact of MX synchrotron beamlines and their evolution is reflected in their scientific output, and MX is now the method of choicemore » for a variety of aims from ligand binding to structure determination of membrane proteins, viruses and ribosomes, resulting in a much deeper understanding of the machinery of life. A main driving force of beamline evolution have been advances in almost every aspect of the instrumentation comprising a synchrotron beamline. In this review we aim to provide an overview of the current status of instrumentation at modern MX experiments. The most critical optical components are discussed, as are aspects of endstation design, sample delivery, visualisation and positioning, the sample environment, beam shaping, detectors and data acquisition and processing.« less

Current advances in synchrotron radiation instrumentation for MX experiments.

PubMed

Owen, Robin L; Juanhuix, Jordi; Fuchs, Martin

2016-07-15

Following pioneering work 40 years ago, synchrotron beamlines dedicated to macromolecular crystallography (MX) have improved in almost every aspect as instrumentation has evolved. Beam sizes and crystal dimensions are now on the single micron scale while data can be collected from proteins with molecular weights over 10 MDa and from crystals with unit cell dimensions over 1000 Å. Furthermore it is possible to collect a complete data set in seconds, and obtain the resulting structure in minutes. The impact of MX synchrotron beamlines and their evolution is reflected in their scientific output, and MX is now the method of choice for a variety of aims from ligand binding to structure determination of membrane proteins, viruses and ribosomes, resulting in a much deeper understanding of the machinery of life. A main driving force of beamline evolution have been advances in almost every aspect of the instrumentation comprising a synchrotron beamline. In this review we aim to provide an overview of the current status of instrumentation at modern MX experiments. The most critical optical components are discussed, as are aspects of endstation design, sample delivery, visualisation and positioning, the sample environment, beam shaping, detectors and data acquisition and processing. Copyright © 2016. Published by Elsevier Inc.

Current advances in synchrotron radiation instrumentation for MX experiments

PubMed Central

Owen, Robin L.; Juanhuix, Jordi; Fuchs, Martin

2017-01-01

Following pioneering work 40 years ago, synchrotron beamlines dedicated to macromolecular crystallography (MX) have improved in almost every aspect as instrumentation has evolved. Beam sizes and crystal dimensions are now on the single micron scale while data can be collected from proteins with molecular weights over 10 MDa and from crystals with unit cell dimensions over 1000 Å. Furthermore it is possible to collect a complete data set in seconds, and obtain the resulting structure in minutes. The impact of MX synchrotron beamlines and their evolution is reflected in their scientific output, and MX is now the method of choice for a variety of aims from ligand binding to structure determination of membrane proteins, viruses and ribosomes, resulting in a much deeper understanding of the machinery of life. A main driving force of beamline evolution have been advances in almost every aspect of the instrumentation comprising a synchrotron beamline. In this review we aim to provide an overview of the current status of instrumentation at modern MX experiments. The most critical optical components are discussed, as are aspects of endstation design, sample delivery, visualization and positioning, the sample environment, beam shaping, detectors and data acquisition and processing. PMID:27046341

Current advances in synchrotron radiation instrumentation for MX experiments

DOE PAGES

Owen, Robin L.; Juanhuix, Jordi; Fuchs, Martin

2016-04-01

Following pioneering work 40 years ago, synchrotron beamlines dedicated to macromolecular crystallography (MX) have improved in almost every aspect as instrumentation has evolved. Beam sizes and crystal dimensions are now on the single micron scale while data can be collected from proteins with molecular weights over 10 MDa and from crystals with unit cell dimensions over 1000 Å. Moreover, it is possible to collect a complete data set in seconds, and obtain the resulting structure in minutes. The impact of MX synchrotron beamlines and their evolution is reflected in their scientific output, and MX is now the method of choicemore » for a variety of aims from ligand binding to structure determination of membrane proteins, viruses and ribosomes, resulting in a much deeper understanding of the machinery of life. One main driving force of beamline evolution have been advances in almost every aspect of the instrumentation comprising a synchrotron beamline. In this review we aim to provide an overview of the current status of instrumentation at modern MX experiments. Furthermore, we discuss the most critical optical components, aspects of endstation design, sample delivery, visualisation and positioning, the sample environment, beam shaping, detectors and data acquisition and processing.« less

Imaging retinal progenitor lineages in developing zebrafish embryos.

PubMed

Jusuf, Patricia; Harris, William A; Poggi, Lucia

2013-03-01

In this protocol, we describe how to make and analyze four dimensional (4D) movies of retinal lineage in the zebrafish embryo in vivo. 4D consists of three spatial dimensions (3D) reconstructed from stacks of confocal planes plus one time dimension. Our imaging is performed on transgenic cells that express fluorescent proteins under the control of cell-specific promoters or on cells that transiently express such reporters in specific retinal cell progenitors. An important aspect of lineage tracing is the ability to follow individual cells as they undergo multiple cell divisions, final migration, and differentiation. This may mean many hours of 4D imaging, requiring that cells be kept healthy and maintained under conditions suitable for normal development. The longest movies we have made are ∼50 h. By analyzing these movies, we can see when a specific cell was born and who its sister was, allowing us to reconstruct its retinal lineages in vivo.

Cell wall-related bionumbers and bioestimates of Saccharomyces cerevisiae and Candida albicans.

PubMed

Klis, Frans M; de Koster, Chris G; Brul, Stanley

2014-01-01

Bionumbers and bioestimates are valuable tools in biological research. Here we focus on cell wall-related bionumbers and bioestimates of the budding yeast Saccharomyces cerevisiae and the polymorphic, pathogenic fungus Candida albicans. We discuss the linear relationship between cell size and cell ploidy, the correlation between cell size and specific growth rate, the effect of turgor pressure on cell size, and the reason why using fixed cells for measuring cellular dimensions can result in serious underestimation of in vivo values. We further consider the evidence that individual buds and hyphae grow linearly and that exponential growth of the population results from regular formation of new daughter cells and regular hyphal branching. Our calculations show that hyphal growth allows C. albicans to cover much larger distances per unit of time than the yeast mode of growth and that this is accompanied by strongly increased surface expansion rates. We therefore predict that the transcript levels of genes involved in wall formation increase during hyphal growth. Interestingly, wall proteins and polysaccharides seem barely, if at all, subject to turnover and replacement. A general lesson is how strongly most bionumbers and bioestimates depend on environmental conditions and genetic background, thus reemphasizing the importance of well-defined and carefully chosen culture conditions and experimental approaches. Finally, we propose that the numbers and estimates described here offer a solid starting point for similar studies of other cell compartments and other yeast species.

Cell Wall-Related Bionumbers and Bioestimates of Saccharomyces cerevisiae and Candida albicans

PubMed Central

de Koster, Chris G.; Brul, Stanley

2014-01-01

Bionumbers and bioestimates are valuable tools in biological research. Here we focus on cell wall-related bionumbers and bioestimates of the budding yeast Saccharomyces cerevisiae and the polymorphic, pathogenic fungus Candida albicans. We discuss the linear relationship between cell size and cell ploidy, the correlation between cell size and specific growth rate, the effect of turgor pressure on cell size, and the reason why using fixed cells for measuring cellular dimensions can result in serious underestimation of in vivo values. We further consider the evidence that individual buds and hyphae grow linearly and that exponential growth of the population results from regular formation of new daughter cells and regular hyphal branching. Our calculations show that hyphal growth allows C. albicans to cover much larger distances per unit of time than the yeast mode of growth and that this is accompanied by strongly increased surface expansion rates. We therefore predict that the transcript levels of genes involved in wall formation increase during hyphal growth. Interestingly, wall proteins and polysaccharides seem barely, if at all, subject to turnover and replacement. A general lesson is how strongly most bionumbers and bioestimates depend on environmental conditions and genetic background, thus reemphasizing the importance of well-defined and carefully chosen culture conditions and experimental approaches. Finally, we propose that the numbers and estimates described here offer a solid starting point for similar studies of other cell compartments and other yeast species. PMID:24243791

Experimental models to study cholangiocyte biology

PubMed Central

Tietz, Pamela S.; Chen, Xian-Ming; Gong, Ai-Yu; Huebert, Robert C.; Masyuk, Anatoliy; Masyuk, Tatyana; Splinter, Patrick L.; LaRusso, Nicholas F.

2002-01-01

Cholangiocytes-the epithelial cells which line the bile ducts-are increasingly recognized as important transporting epithelia actively involved in the absorption and secretion of water, ions, and solutes. This recognition is due in part to the recent development of new experimental models. New biologic concepts have emerged including the identification and topography of receptors and flux proteins on the apical and/or basolateral membrane which are involved in the molecular mechanisms of ductal bile secretion. Individually isolated and/or perfused bile duct units from livers of rats and mice serve as new, physiologically relevant in vitro models to study cholangiocyte transport. Biliary tree dimensions and novel insights into anatomic remodeling of proliferating bile ducts have emerged from three-dimensional reconstruction using CT scanning and sophisticated software. Moreover, new pathologic concepts have arisen regarding the interaction of cholangiocytes with pathogens such as Cryptosporidium parvum. These concepts and associated methodologies may provide the framework to develop new therapies for the cholangiopathies, a group of important hepatobiliary diseases in which cholangiocytes are the target cell. PMID:11833061

The Mediating Effects of Basic Psychological Needs at Work on the Relationship between the Dimensions of the Learning Organization and Organizational Commitment in Registered Nurses

ERIC Educational Resources Information Center

Baird, Bonni Lynn

2012-01-01

The purpose of this study was to determine the mediating effects of the Basic Psychological Needs at Work, comprised of competence, autonomy and relatedness, on the relationship between the Dimensions of the Learning Organization and affective and normative organizational commitment in the United States nursing population. The study incorporated…

Human Dimensions of Strategic Leadership : A Selected Bibliogrpahy

DTIC Science & Technology

2013-09-01

2011. 27pp. (AD-A553-001) http://handle.dtic.mil/100.2/ADA553001 Michelson, Brian M. Character Development of U.S. Army Leaders: A Laissez Faire ...Maxime A. “ Fairness Perceptions and Trust as Mediators on the Relationship between Leadership Style, Unit Commitment, and Turnover Intentions of Canadian...HUMAN DIMENSIONS OF STRATEGIC LEADERSHIP A Selected Bibliography U.S. ARMY WAR COLLEGE LIBRARY September 2013

Comparative analysis of age dynamics of average values of body dimensions in children from birth to 7 years.

PubMed

Deryabin, Vasily E; Krans, Valentina M; Fedotova, Tatiana K

2005-07-01

Mean values of different body dimensions in different age cohorts of children make it possible to learn a lot about their dynamic changes. Their comparative analysis, as is usually practiced, in fact leads to a simple description of changes in measurement units (mm or cm) at the average level of some body dimension during a shorter or longer period of time. To estimate comparative intensity of the growth process of different body dimensions, the authors use the analogue of Mahalanobis distance, the so-called Kullback divergence (1967), which does not demand stability of dispersion or correlation coefficients of dimensions in compared cohorts of children. Most of the dimensions, excluding skinfolds, demonstrate growth dynamics with gradually reducing increments from birth to 7 years. Body length has the highest integrative increment, leg length about 94% of body length, body mass 77%, and trunk and extremities circumferences 56%. Skinfolds have a non-monotonic pattern of accumulated standardized increments with some increase until 1-2 years of age.

Black Hole Entropy Calculated via Wavefunction Approximations on a Schwarzschild Spacetime

DTIC Science & Technology

2015-05-18

dimension of μA is kg2m2s−2 which is the expected dimension . The μ2B has an extra unit of length in the numerator but is also divided by another factor...phenomena. The two ideas were General Relativity (GR) and Quantum Mechanics (QM). General relativity describes physics on large scales with masses the size...operator ̂L = ̂r × ̂p. These operators can be written in three dimensions in a compact way by using the del operator4 ∇ = ∂xî+ ∂y ĵ + ∂zk̂, ̂p

Control of cellular organization in three dimensions using a microfabricated polydimethylsiloxane-collagen composite tissue scaffold.

PubMed

Norman, James J; Desai, Tejal A

2005-01-01

Parallel channels of various dimensions have been shown to cause a monolayer of cells in culture to align in the direction of the channels. For the engineering of complex organ systems to become a reality, similar control over the cellular microenvironment in three dimensions must be achieved. Using microfabrication, a polydimethylsiloxane (PDMS) scaffold (40 microm wide, 70-microm-deep parallel channels separated by 25-microm-wide walls) was created. A fibroblast-seeded collagen matrix was then molded around this PDMS scaffold. The PDMS scaffold served as an internal skeleton to guide the cells to grow in the prescribed three-dimensional pattern. Organization, aspect ratio, and the z diameter of the cells were analyzed by confocal microscopy. Fibroblasts elongated and organized in the direction of the channels throughout the height of the scaffold. The mean angle of the cells off of the long axis of the channels was 4.3 +/- 0.7 degrees as opposed to 32.6 +/- 2.2 degrees in controls. The morphology of the cells was also affected by the PDMS scaffold. The nuclei were longer (1.25x) and thinner (0.75x) than in control gels; however, no changes in diameter of the cells in the z direction were seen.

[Comparative study of burnout in Intensive Care and Emergency Care nursing staff].

PubMed

Ríos Risquez, M I; Godoy Fernández, C; Peñalver Hernández, F; Alonso Tovar, A R; López Alcaraz, F; López Romera, A; Garnés González, S; Salmerón Saura, E; López Real, M D; Ruiz Sánchez, R; Simón Domingo, P; Manzanera Nicolás, J L; Menchón Almagro, M A; Liébanas Bellón, R

2008-01-01

To assess and compare the burnout level between Intensive Care Unit and Emergency Unit, and study its association with the sociodemographic and work characteristics of the professionals surveyed. Cross-sectional, descriptive study. Emplacement. Intensive Care Unit of the university hospital Morales Meseguer, Murcia-Spain. STUDIED SAMPLE: 97 nursing professionals: 55 professionals belong to the Emergency Department, and 42 professionals belong to the Intensive Care Department. Two evaluation tools were used: a sociodemographic and work survey, and the Maslach Burnout Inventory, 1986. Quantitative variables expressed as mean +/- SD compared with the Student's T test and qualitative variables compared with the chi2 test. SPSS 12.0(c). The comparative analysis of the burnout dimensions shows that emotional exhaustion level is significantly higher in the intensive care service than in the emergency one (25.45 +/- 11.15 vs 22.09 +/- 10.99) p < 0.05. The rest of burnout dimensions do not show significant differences between both departments. The masculine gender obtains a higher score in the depersonalization dimension of burnout (10.12 +/- 5.38) than female one (6.7 +/- 5.21) p < 0.01. There is greater vulnerability to emotional exhaustion among the professional group with more than 15 years of work experience (F = 3.592; p = 0.031). The burnout levels are moderate to high among the nursing professionals studied. A total of 5.15% of the sample studied achieves a high score in the three dimensions of the burnout syndrome. The intensive care professionals are the most vulnerable to suffering high levels of emotional exhaustion, and the masculine gender is more susceptible to depersonalization attitudes.

Limits on the Time Evolution of Space Dimensions from Newton's Constant

NASA Astrophysics Data System (ADS)

Nasseri, Forough

Limits are imposed upon the possible rate of change of extra spatial dimensions in a decrumpling model Universe with time variable spatial dimensions (TVSD) by considering the time variation of (1+3)-dimensional Newton's constant. Previous studies on the time variation of (1+3)-dimensional Newton's constant in TVSD theory had not include the effects of the volume of the extra dimensions and the effects of the surface area of the unit sphere in D-space dimensions. Our main result is that the absolute value of the present rate of change of spatial dimensions to be less than about 10-14 yr-1. Our results would appear to provide a prima facie case for ruling the TVSD model out. We show that based on observational bounds on the present variation of Newton's constant, one would have to conclude that the spatial dimension of the Universe when the Universe was "at the Planck scale" to be less than or equal to 3.09. If the dimension of space when the Universe was "at the Planck scale" is constrained to be fractional and very close to 3, then the whole edifice of TVSD model loses credibility.

Detectability index of differential phase contrast CT compared with conventional CT: a preliminary channelized Hotelling observer study

NASA Astrophysics Data System (ADS)

Tang, Xiangyang; Yang, Yi; Tang, Shaojie

2013-03-01

Under the framework of model observer with signal and background exactly known (SKE/BKE), we investigate the detectability of differential phase contrast CT compared with that of the conventional attenuation-based CT. Using the channelized Hotelling observer and the radially symmetric difference-of-Gaussians channel template , we investigate the detectability index and its variation over the dimension of object and detector cells. The preliminary data show that the differential phase contrast CT outperforms the conventional attenuation-based CT significantly in the detectability index while both the object to be detected and the cell of detector used for data acquisition are relatively small. However, the differential phase contrast CT's dominance in the detectability index diminishes with increasing dimension of either object or detector cell, and virtually disappears while the dimension of object or detector cell approaches a threshold, respectively. It is hoped that the preliminary data reported in this paper may provide insightful understanding of the differential phase contrast CT's characteristic in the detectability index and its comparison with that of the conventional attenuation-based CT.

Cell type classifiers for breast cancer microscopic images based on fractal dimension texture analysis of image color layers.

PubMed

Jitaree, Sirinapa; Phinyomark, Angkoon; Boonyaphiphat, Pleumjit; Phukpattaranont, Pornchai

2015-01-01

Having a classifier of cell types in a breast cancer microscopic image (BCMI), obtained with immunohistochemical staining, is required as part of a computer-aided system that counts the cancer cells in such BCMI. Such quantitation by cell counting is very useful in supporting decisions and planning of the medical treatment of breast cancer. This study proposes and evaluates features based on texture analysis by fractal dimension (FD), for the classification of histological structures in a BCMI into either cancer cells or non-cancer cells. The cancer cells include positive cells (PC) and negative cells (NC), while the normal cells comprise stromal cells (SC) and lymphocyte cells (LC). The FD feature values were calculated with the box-counting method from binarized images, obtained by automatic thresholding with Otsu's method of the grayscale images for various color channels. A total of 12 color channels from four color spaces (RGB, CIE-L*a*b*, HSV, and YCbCr) were investigated, and the FD feature values from them were used with decision tree classifiers. The BCMI data consisted of 1,400, 1,200, and 800 images with pixel resolutions 128 × 128, 192 × 192, and 256 × 256, respectively. The best cross-validated classification accuracy was 93.87%, for distinguishing between cancer and non-cancer cells, obtained using the Cr color channel with window size 256. The results indicate that the proposed algorithm, based on fractal dimension features extracted from a color channel, performs well in the automatic classification of the histology in a BCMI. This might support accurate automatic cell counting in a computer-assisted system for breast cancer diagnosis. © Wiley Periodicals, Inc.

Emotional Availability Scale Among Three U.S. Race/Ethnic Groups.

PubMed

Derscheid, Della J; Fogg, Louis F; Julion, Wrenetha; Johnson, Mary E; Tucker, Sharon; Delaney, Kathleen R

2018-05-01

This study used a cross-sectional design to conduct a subgroup psychometric analysis of the Emotional Availability Scale among matched Hispanic ( n = 20), African American ( n = 20), and European American ( n = 10) English-speaking mother-child dyads in the United States. Differences by race/ethnicity were tested ( p < .05) among (a) Emotional Availability Scale dimensions with ANOVA, and (b) relationships of Emotional Availability Scale dimensions with select Dyadic Parent-Child Interaction Coding System variables with Pearson correlation and matched moderated regression. Internal consistency was .950 (Cronbach's α; N = 50). No significant differences in the six Emotional Availability Scale dimension scores by race/ethnicity emerged. Two Dyadic Parent-Child Interaction Coding System behaviors predicted two Emotional Availability Scale dimensions each for Hispanic and African American mother-child dyads. Results suggest emotional availability similarity among race/ethnic subgroups with few predictive differences of emotional availability dimensions by specific behaviors for Hispanic and African American subgroups.

Dimensions of Oppression in the Lives of Impoverished Black Women Who Use Drugs

PubMed Central

Windsor, Liliane Cambraia; Benoit, Ellen; Dunlap, Eloise

2010-01-01

Oppression against Black women continues to be a significant problem in the United States. The purpose of this study is to use grounded theory to identify multiple dimensions of oppression experienced by impoverished Black women who use drugs by examining several settings in which participants experience oppression. Three case studies of drug using, impoverished Black women were randomly selected from two large scale consecutive ethnographic studies conducted in New York City from 1998 to 2005. Analysis revealed five dimensions of oppression occurring within eight distinct settings. While dimensions constitute different manifestations of oppression, settings represented areas within participants’ lives or institutions with which participants interact. Dimensions of oppression included classism, sexism, familism, racism, and drugism. Settings included the school system, correction system, welfare system, housing and neighborhood, relationship with men, family, experiences with drug use, and employment. Findings have important implications for social justice, welfare, drug, and justice system policy. PMID:21113410

Modeling human development in 3D culture.

PubMed

Ader, Marius; Tanaka, Elly M

2014-12-01

Recently human embryonic stem cell research has taken on a new dimension - the third dimension. Capitalizing on increasing knowledge on directing pluripotent cells along different lineages, combined with ECM supported three-dimensional culture conditions, it has become possible to generate highly organized tissues of the central nervous system, gut, liver and kidney. Each system has been used to study different aspects of organogenesis and function including physical forces underlying optic cup morphogenesis, the function of disease related genes in progenitor cell control, as well as interaction of the generated tissues with host tissue upon transplantation. Pluripotent stem cell derived organoids represent powerful systems for the study of how cells self-organize to generate tissues with a given shape, pattern and form. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ancient Egypt.

ERIC Educational Resources Information Center

Evers, Virginia

This four-week fourth grade social studies unit dealing with religious dimensions in ancient Egyptian culture was developed by the Public Education Religion Studies Center at Wright State University. It seeks to help students understand ancient Egypt by looking at the people, the culture, and the people's world view. The unit begins with outlines…

Acculturation Experiences of Taiwanese Students during Exchanges in the United States

ERIC Educational Resources Information Center

Lee, Annie (Ya-Ping); Bei, Lienti; DeVaney, Sharon A.

2007-01-01

This phenomenological study examined the acculturation experience of Taiwanese students who attended universities in the United States as exchange students. Hofstede's four dimensions of culture provided a framework for developing questions. Eight exchange students were interviewed. Taiwanese students realized there was a lower power distance…

Preferred Styles of Conflict Resolution. Mexico and the United States.

ERIC Educational Resources Information Center

Gabrielidis, Cristina; Stephan, Walter G.; Ybarra, Oscar; Pearson, Virginia Dos Santos; Villareal, Lucila

1997-01-01

Examined cultural differences in preferences for conflict resolution styles using the dual-concern model with 103 college students in Mexico (collectivistic culture) and 91 college students in the United States (individualistic culture). Results suggest that independence of the self and interdependence of the self may be separate dimensions,…

Names: A New Dimension of Transformation

ERIC Educational Resources Information Center

Payne, Keisha E.; Philyaw, Zackary; Rabow, Jerome; Yazdanfar, Sara

2018-01-01

This paper examines the impact and consequences on college students in the United States whose names are Americanized ('Americanization' is used throughout this paper to apply only to residents of the United States and has two possible meanings: within the US, it refers to acculturation of immigrants, whereas internationally it refers to the…

All unital qubit channels are 4-noisy operations

NASA Astrophysics Data System (ADS)

Müller-Hermes, Alexander; Perry, Christopher

2018-06-01

We show that any unital qubit channel can be implemented by letting the input system interact unitarily with a four-dimensional environment in the maximally mixed state and then tracing out the environment. We also provide an example where the dimension of such an environment has to be at least 3.

Crisis in Feminism: The United States and France.

ERIC Educational Resources Information Center

Hogsett, Charlotte

Feminism is experiencing a similar dual crisis in the United States and France. One aspect of this crisis, the movement's alignment with other groups, is destructive, inevitably leading to the subordination of women's issues to "human" issues. The other dimension of the crisis, internal differences, is potentially creative, offering the…

Better understanding work unit goal orientation: Its emergence and impact under different types of work unit structure.

PubMed

Dragoni, Lisa; Kuenzi, Maribeth

2012-09-01

With a multisource sample comprising 1,150 employees and 230 supervisors, we investigate the effect of leader goal orientation on leader's perceptions of unit performance. We propose that a leader's goal orientation indirectly impacts performance perceptions via the shared achievement goal adopted within the unit (i.e., unit goal orientation). Further, we hypothesize that the presence and impact of unit goal orientation depend on the work unit structure. We find general support for this moderated mediation model, with the strongest evidence being associated with the learning and prove dimensions of goal orientation.

Predictive Management of Asian Carps in the Upper Mississippi River System

USGS Publications Warehouse

Vondracek, Bruce C.; Carlson, Andrew K.

2014-01-01

Prolific non-native organisms pose serious threats to ecosystems and economies worldwide. Nonnative bighead carp (Hypophthalmichthys nobilis) and silver carp (H. molitrix), collectively referred to as Asian carps, continue to colonize aquatic ecosystems throughout the central United States. These species are r-selected, exhibiting iteroparous spawning, rapid growth, broad environmental tolerance, high density, and long-distance movement. Hydrological, thermal, and physicochemical conditions are favorable for establishment beyond the current range, rendering containment and control imperative. Ecological approaches to confine Asian carp populations and prevent colonization characterize contemporary management in the United States. Foraging and reproduction of Asian carps govern habitat selection and movement, providing valuable insight for predictive control. Current management approaches are progressive and often anticipatory but deficient in human dimensions. We define predictive management of Asian carps as synthesis of ecology and human dimensions at regional and local scales to develop strategies for containment and control. We illustrate predictive management in the Upper Mississippi River System and suggest resource managers integrate predictive models, containment paradigms, and human dimensions to design effective, socially acceptable management strategies. Through continued research, university-agency collaboration, and public engagement, predictive management of Asian carps is an auspicious paradigm for preventing and alleviating consequences of colonization in the United States.

Quality of work life as a predictor of nurses' intention to leave units, organisations and the profession.

PubMed

Lee, Ya-Wen; Dai, Yu-Tzu; McCreary, Linda L

2015-05-01

To examine the relationships between quality of work life (QWL) and nurses' intention to leave their unit (ITLunit), organisation (ITLorg) and profession (ITLpro). The high turnover rate among nurses presents a major challenge to health care systems across the globe. QWL plays a significant role in nurses' turnover. A descriptive cross-sectional survey design was conducted via purposive sampling of 1283 hospital nurses and administering the Chinese version of the Quality of Nursing Work Life scale (C-QNWL), a three-ITL-type scale questionnaire, and a demographic questionnaire for individual- and work-related variables. Descriptive data, correlations, and ordinal regression models were analyzed. QWL predicted ITLpro and ITLorg better than ITLunit. Three QWL dimensions (work arrangement and workload, nursing staffing and patient care, and work-home life balance) were significantly predictive of all three ITL measures. However, the dimension of teamwork and communication was only predictive for ITLunit, not for ITLorg and ITLpro. Different patterns of QWL dimensions are predictive of ITLunit, ITLorg, and ITLpro. The study provides important information to nurse administrators about the aspects of QWL that most commonly lead nurses to leave their units, organisations, and even the profession itself. © 2013 John Wiley & Sons Ltd.

Abstract feature codes: The building blocks of the implicit learning system.

PubMed

Eberhardt, Katharina; Esser, Sarah; Haider, Hilde

2017-07-01

According to the Theory of Event Coding (TEC; Hommel, Müsseler, Aschersleben, & Prinz, 2001), action and perception are represented in a shared format in the cognitive system by means of feature codes. In implicit sequence learning research, it is still common to make a conceptual difference between independent motor and perceptual sequences. This supposedly independent learning takes place in encapsulated modules (Keele, Ivry, Mayr, Hazeltine, & Heuer 2003) that process information along single dimensions. These dimensions have remained underspecified so far. It is especially not clear whether stimulus and response characteristics are processed in separate modules. Here, we suggest that feature dimensions as they are described in the TEC should be viewed as the basic content of modules of implicit learning. This means that the modules process all stimulus and response information related to certain feature dimensions of the perceptual environment. In 3 experiments, we investigated by means of a serial reaction time task the nature of the basic units of implicit learning. As a test case, we used stimulus location sequence learning. The results show that a stimulus location sequence and a response location sequence cannot be learned without interference (Experiment 2) unless one of the sequences can be coded via an alternative, nonspatial dimension (Experiment 3). These results support the notion that spatial location is one module of the implicit learning system and, consequently, that there are no separate processing units for stimulus versus response locations. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

[Parental stressors in a Pediatric Intensive Care Unit].

PubMed

Ramírez, Muriel; Navarro, Sandra; Clavería, Cristián; Molina, Yerko; Cox, Alfonso

2018-04-01

The hospitalization of a child is a situation that produces a high level of stress on parents, especially at the Pediatric Intensive Care Unit (PICU). To determine which are the main stressors perceived by the parents of children hospitalized at PICU and the associated variables. A quantitative, cross-sectional and correlational study, which considers the secondary analysis of data from the IDA project # 201403 of UC School of Nursing: Validation of "The parental stressor scale infant hospitalization in Spanish" (PSSIH modified). Sampling was non probabilistic by convenience, with 217 parents of children at the PICU of a University hospital, who answered a demographic questionnaire and the modified PSSIH instrument to measure stressors in the PICU environment. Three dimensions of stressors were identified: Clinical, Emotional and Communication with the professional team. The clinical dimension was the most stressful, with the factors images or sounds, procedures and interventions and the aspect of the child, dimensions related to behavior and communication with the team were less stressful. In addition, it is associated with a greater perception of stress in the different dimensions, when having: previous experiences in PICU, programmed admission, admission due tocardiac pathology, single child, higher educational level and no partner. The modified PSSIH instrument made it possible to determine the main stressors perceived by the parents of children in the PICU, the Clinical dimension being the major stressor. These results are useful for developing local intervention programs according to the particular characteristics of the PICU.

Tension and Elasticity Contribute to Fibroblast Cell Shape in Three Dimensions.

PubMed

Brand, Christoph A; Linke, Marco; Weißenbruch, Kai; Richter, Benjamin; Bastmeyer, Martin; Schwarz, Ulrich S

2017-08-22

The shape of animal cells is an important regulator for many essential processes such as cell migration or division. It is strongly determined by the organization of the actin cytoskeleton, which is also the main regulator of cell forces. Quantitative analysis of cell shape helps to reveal the physical processes underlying cell shape and forces, but it is notoriously difficult to conduct it in three dimensions. Here we use direct laser writing to create 3D open scaffolds for adhesion of connective tissue cells through well-defined adhesion platforms. Due to actomyosin contractility in the cell contour, characteristic invaginations lined by actin bundles form between adjacent adhesion sites. Using quantitative image processing and mathematical modeling, we demonstrate that the resulting shapes are determined not only by contractility, but also by elastic stress in the peripheral actin bundles. In this way, cells can generate higher forces than through contractility alone. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Comparison between cylindrical and prismatic lithium-ion cell costs using a process based cost model

NASA Astrophysics Data System (ADS)

Ciez, Rebecca E.; Whitacre, J. F.

2017-02-01

The relative size and age of the US electric vehicle market means that a few vehicles are able to drive market-wide trends in the battery chemistries and cell formats on the road today. Three lithium-ion chemistries account for nearly all of the storage capacity, and half of the cells are cylindrical. However, no specific model exists to examine the costs of manufacturing these cylindrical cells. Here we present a process-based cost model tailored to the cylindrical lithium-ion cells currently used in the EV market. We examine the costs for varied cell dimensions, electrode thicknesses, chemistries, and production volumes. Although cost savings are possible from increasing cell dimensions and electrode thicknesses, economies of scale have already been reached, and future cost reductions from increased production volumes are minimal. Prismatic cells, which are able to further capitalize on the cost reduction from larger formats, can offer further reductions than those possible for cylindrical cells.

Effect of Microstructural Parameters on the Relative Densities of Metal Foams

NASA Technical Reports Server (NTRS)

Raj, S. V.; Kerr, Jacob A.

2010-01-01

A detailed quantitative microstructural analyses of primarily open cell FeCrAlY and 314 stainless steel metal foams with different relative densities and pores per inch (p.p.i.) were undertaken in the present investigation to determine the effect of microstructural parameters on the relative densities of metal foams. Several elements of the microstructure, such as longitudinal and transverse cell sizes, cell areas and perimeters, ligament dimensions, cell shapes and volume fractions of closed and open cells, were measured. The cross-sections of the foam ligaments showed a large number of shrinkage cavities, and their circularity factors and average sizes were determined. The volume fractions of closed cells increased linearly with increasing relative density. In contrast, the volume fractions of the open cells and ligaments decreased with increasing relative density. The relative densities and p.p.i. were not significantly dependent on cell size, cell perimeter and ligament dimensions within the limits of experimental scatter. A phenomenological model is proposed to rationalize the present microstructural observations.

Factors influencing intracranial vessel densities on unenhanced computed tomography: differences between hemispheres.

PubMed

Grams, Astrid E; Rehwald, Rafael; Schmittnägel, Charlotte; Schmidt, Thorsten; Tanislav, Christian; Berghoff, Martin; Krombach, Gabriele A; Moritz, Regina; Obert, Martin; Gizewski, Elke R; Glodny, Bernhard

The aim was to identify the factors influencing intracranial vessel density (VD). The Hounsfield units of the dense vessel and the contralateral side were measured in 34 patients with arterial clots, 20 with venous clots, and 196 without clots and correlated with skull thickness, density and dimensions, gender, age, red blood cell count (RBC), hemoglobin (HB), hematocrit (HT), creatinine, and sodium. Positive correlations were found between VD and HT, RBC, HB, creatinine, and occipital bone density. Density differences between the right and left intracranial vessels were more accurate (sensitivity/specificity/accuracy=0.91/0.93/0.93 and 0.75/0.87/0.85, respectively) for detecting clots than VD alone. HT, RBC, and HB are the main factors that correlate with VD. Copyright © 2016 Elsevier Inc. All rights reserved.

Phase Equilibria and Crystal Chemistry in Portions of the System SrO-CaO-Bi2O3-CuO, Part IV— The System CaO-Bi2O3-CuO

PubMed Central

Burton, B. P.; Rawn, C. J.; Roth, R. S.; Hwang, N. M.

1993-01-01

New data are presented on the phase equilibria and crystal chemistry of the binary systems CaO-Bi2O3 and CaO-CuO and the ternary CaO-Bi2O3-CuO. Symmetry data and unit cell dimensions based on single crystal and powder x-ray diffraction measurements are reported for several of the binary CaO-Bi2O3 phases, including corrected compositions for Ca4Bi6O13 and Ca2Bi2O5. The ternary system contains no new ternary phases which can be formed in air at ~700–900 °C. PMID:28053484

Crystal structure of κ-Ag2Mg5

NASA Astrophysics Data System (ADS)

Castro, Facundo J.; Primo, Gastón A.; Urretavizcaya, Guillermina

2018-02-01

The structure of κ-Ag2Mg5 has been refined based on X-ray powder diffraction measurements (Rwp = 0.083). The compound has been prepared by combining mechanical alloying techniques and thermal treatments. The intermetallic presents the prototypical structure of Co2Al5, an hexagonal crystal with the symmetries of space group P63/mmc, and belongs to the family of kappa-phase structure compounds. The unit cell dimensions are a=8.630(1) Å and c=8.914(1) Å. Five crystallographically independent sites are occupied, Wyckoff positions 12k, 6h and 2a are filled with Mg, another 6h site is occupied with Ag, and the 2c site presents mixed Ag/Mg occupancy. The crystal chemistry of the structure and bonding are briefly discussed in the paper.

TEM study on a new Zr-(Fe, Cu) phase in furnace-cooled Zr-1.0Sn-0.3Nb-0.3Fe-0.1Cu alloy

NASA Astrophysics Data System (ADS)

Liu, Yushun; Qiu, Risheng; Luan, Baifeng; Hao, Longlong; Tan, Xinu; Tao, Boran; Zhao, Yifan; Li, Feitao; Liu, Qing

2018-06-01

A new Zr-(Fe, Cu) phase was found in furnace-cooled Zr-1.0Sn-0.3Nb-0.3Fe- 0.1Cu alloy and alloys aged at 580 °C for 10min, 2 h and 10 h. Electron diffraction experiment shows the crystal structure of this phase to be body-centered tetragonal with unit cell dimensions determined to be a = b = 6.49 Å, c = 5.37 Å. Its possible space groups have been discussed and the reason accounting for its formation is believed to be the addition of Cu according to the atom-level images. In addition, no crystal structural or chemical composition changes were observed throughout the aging process.

Active control of a plasmonic metamaterial for quantum state engineering

NASA Astrophysics Data System (ADS)

Uriri, S. A.; Tashima, T.; Zhang, X.; Asano, M.; Bechu, M.; Güney, D. Ö.; Yamamoto, T.; Özdemir, Ş. K.; Wegener, M.; Tame, M. S.

2018-05-01

We experimentally demonstrate the active control of a plasmonic metamaterial operating in the quantum regime. A two-dimensional metamaterial consisting of unit cells made from gold nanorods is investigated. Using an external laser, we control the temperature of the metamaterial and carry out quantum process tomography on single-photon polarization-encoded qubits sent through, characterizing the metamaterial as a variable quantum channel. The overall polarization response can be tuned by up to 33% for particular nanorod dimensions. To explain the results, we develop a theoretical model and find that the experimental results match the predicted behavior well. This work goes beyond the use of simple passive quantum plasmonic systems and shows that external control of plasmonic elements enables a flexible device that can be used for quantum state engineering.

Scalable Production of Glioblastoma Tumor-initiating Cells in 3 Dimension Thermoreversible Hydrogels

NASA Astrophysics Data System (ADS)

Li, Qiang; Lin, Haishuang; Wang, Ou; Qiu, Xuefeng; Kidambi, Srivatsan; Deleyrolle, Loic P.; Reynolds, Brent A.; Lei, Yuguo

2016-08-01

There is growing interest in developing drugs that specifically target glioblastoma tumor-initiating cells (TICs). Current cell culture methods, however, cannot cost-effectively produce the large numbers of glioblastoma TICs required for drug discovery and development. In this paper we report a new method that encapsulates patient-derived primary glioblastoma TICs and grows them in 3 dimension thermoreversible hydrogels. Our method allows long-term culture (~50 days, 10 passages tested, accumulative ~>1010-fold expansion) with both high growth rate (~20-fold expansion/7 days) and high volumetric yield (~2.0 × 107 cells/ml) without the loss of stemness. The scalable method can be used to produce sufficient, affordable glioblastoma TICs for drug discovery.

Higher Education into the 1990s: New Dimensions. To Commemorate the Jubilee of the Society for Research into Higher Education, 1964-1989.

ERIC Educational Resources Information Center

Ball, Christopher, Ed.; Eggins, Heather, Ed.

This collection of essays aims to contribute to the understanding of the present predicament and future potential of higher education in the United Kingdom. It considers the new dimensions being introduced into higher education which are likely to have marked effects in the 1990s. It explores the tensions between the past and future, tradition and…

An Evaluation of an Attitudinal Model to Measure the Potential for Combat Effectiveness of U.S. Air Force Organizations.

DTIC Science & Technology

1982-09-01

Fight Combat Effectiveness Organizational Assessment Package Morale Combat Effectiveness Model Cohesion Leadership 20. AIISTRACT (COe/Mie do ,eae aide If...of combat readiness. The major psychosocial dimensions which contribute to combat effectiveness of a military unit (morale leadership , cohesion, and...psychosocial dimensions in the combat effectiveness model (morale, leadership , and cohesion) in addition to training, logistics, alienation, and work group

Interpersonal problems, dependency, and self-criticism in major depressive disorder.

PubMed

Dinger, Ulrike; Barrett, Marna S; Zimmermann, Johannes; Schauenburg, Henning; Wright, Aidan G C; Renner, Fritz; Zilcha-Mano, Sigal; Barber, Jacques P

2015-01-01

The goal of the present research was the examination of overlap between 2 research traditions on interpersonal personality traits in major depression. We hypothesized that Blatt's (2004) dimensions of depressive experiences around the dimensions of relatedness (i.e., dependency) and self-definition (i.e., self-criticism) are associated with specific interpersonal problems according to the interpersonal circumplex model (Leary, 1957). In addition, we examined correlations of interpersonal characteristics with depression severity. Analyses were conducted on 283 patients with major depressive disorder combined from 2 samples. Of the patients, 151 participated in a randomized controlled trial in the United States, and 132 patients were recruited in an inpatient unit in Germany. Patients completed measures of symptomatic distress, interpersonal problems, and depressive experiences. Dependency was associated with more interpersonal problems related to low dominance and high affiliation, while self-criticism was associated with more interpersonal problems related to low affiliation. These associations were independent of depression severity. Self-criticism showed high overlap with cognitive symptoms of depression. The findings support the interpersonal nature of Blatt's dimensions of depressive experiences. Self-criticism is associated with being too distant or cold toward others as well as greater depression severity, but is not related to the dimension of dominance. © 2014 Wiley Periodicals, Inc.

Capturing the Two Dimensions of Residential Segregation at the Neighborhood Level for Health Research

PubMed Central

Oka, Masayoshi; Wong, David W. S.

2014-01-01

Two conceptual and methodological foundations of segregation studies are that (i) segregation involves more than one group, and (ii) segregation measures need to quantify how different population groups are distributed across space. Therefore, percentage of population belonging to a group is not an appropriate measure of segregation because it does not describe how populations are spread across different areal units or neighborhoods. In principle, evenness and isolation are the two distinct dimensions of segregation that capture the spatial patterns of population groups. To portray people’s daily environment more accurately, segregation measures need to account for the spatial relationships between areal units and to reflect the situations at the neighborhood scale. For these reasons, the use of local spatial entropy-based diversity index (SHi) and local spatial isolation index (Si) to capture the evenness and isolation dimensions of segregation, respectively, are preferable. However, these two local spatial segregation indexes have rarely been incorporated into health research. Rather ineffective and insufficient segregation measures have been used in previous studies. Hence, this paper empirically demonstrates how the two measures can reflect the two distinct dimensions of segregation at the neighborhood level, and argues conceptually and set the stage for their future use to effectively and meaningfully examine the relationships between residential segregation and health. PMID:25202687

Material nature versus structural nurture: the embodied carbon of fundamental structural elements.

PubMed

Purnell, P

2012-01-03

The construction industry is under considerable legislative pressure to reduce its CO(2) emissions. The current focus is on operational CO(2) emissions, but as these are compulsorily reduced, the embodied CO(2) of structural components, overwhelmingly attributable to the material from which they are manufactured, will become of greater interest. Choice of structural materials for minimal embodied CO(2) is currently based either on subjective narrative arguments, or values of embodied CO(2) per unit volume or mass. Here we show that such arguments are invalid. We found that structural design parameters (dimensions, section choice, and load capacity) for fundamental structural components (simple beams and columns) are at least as important as material choice with regard to their effect on embodied CO(2) per unit load capacity per unit dimension, which can vary over several decades within and between material choices. This result demonstrates that relying on apparently objective analyses based on embodied CO(2) per unit volume or mass will not lead to minimum carbon solutions; a formal definition of the correct functional unit for embodied CO(2) must be used. In short, there is no such thing as a green structural material.

A cost-benefit analysis of demand for food.

PubMed Central

Hursh, S R; Raslear, T G; Shurtleff, D; Bauman, R; Simmons, L

1988-01-01

Laboratory studies of consumer demand theory require assumptions regarding the definition of price in the absence of a medium of exchange (money). In this study we test the proposition that the fundamental dimension of price is a cost-benefit ratio expressed as the effort expended per unit of food value consumed. Using rats as subjects, we tested the generality of this "unit price" concept by varying four dimensions of price: fixed-ratio schedule, number of food pellets per fixed-ratio completion, probability of reinforcement, and response lever weight or effort. Two levels of the last three factors were combined in a 2 x 2 x 2 design giving eight groups. Each group was studied under a series of six FR schedules. Using the nominal values of all factors to determine unit price, we found that grams of food consumed plotted as a function of unit price followed a single demand curve. Similarly, total work output (responses x effort) conformed to a single function when plotted in terms of unit price. These observations provided a template for interpreting the effects of biological factors, such as brain lesions or drugs, that might alter the cost-benefit ratio. PMID:3209958

Velocity Profiles of Slow Blood Flow in a Narrow Tube

NASA Astrophysics Data System (ADS)

Chen, Jinyu; Huang, Zuqia; Zhuang, Fengyuan; Zhang, Hui

1998-04-01

A fractal model is introduced into the slow blood motion. When blood flows slowly in a narrow tube, red cell aggregation results in the formation of an approximately cylindrical core of red cells. By introducing the fractal model and using the power law relation between area fraction φ and distance from tube axis ρ, rigorous velocity profiles of the fluid in and outside the aggregated core and of the core itself are obtained analytically for different fractal dimensions. It shows a blunted velocity distribution for a relatively large fractal dimension (D ˜ 2), which can be observed in normal blood; a pathological velocity profile for moderate dimension (D = 1), which is similar to the Segre-Silberberg effect; and a parabolic profile for negligible red cell concentration (D = 0), which likes in the Poiseuille flow. The project supported by the National Basic Research Project "Nonlinear Science", National Natural Science Foundation of China and the State Education Commission through the Foundation of Doctoral Training

Modification of the semitransparent Prunus serrula bark film: Making rubber out of bark

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

Xu, X.; Zaremba, C.; Stucky, G.D.

1998-11-01

The authors report an extensive structural and mechanical characterization of the semitransparent bark of Prunus serrula. Variations in the properties were observed. Mechanical properties along the fiber axis of these films are strongly related to the cell dimensions. Several trends can be seen with increasing cell length: tensile strength and Young`s modulus increase; ductility decreases. Perpendicular to the fiber axis, similar radial dimensions of the bark cells contributes to similar mechanical properties. Plasticization not only shrinks the dimension of the bulk films along the tangential axis, which is unique, but also dramatically changes the mechanical properties. The authors have shown,more » for the first time, that the mechanical properties of the Prunus serrula bark can be effectively tailored with different plasticization and modification agents. The plastic bark can be successfully converted to rubberlike material either temporally or permanently, or it can be strengthened by tensile deformation of the plasticized bark.« less

Reverse depletion effects and the determination of ligand density on some spherical bioparticles

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

Wang, Chunxiang; Liu, Yanhui, E-mail: ionazati@itp.ac.cn; Fan, Yangtao

In cell environments crowded with macromolecules, the depletion effects act and assist in the assembly of a wide range of cellular structures, from the cytoskeleton to the chromatin loop, which are well accepted. But a recent quantum dot experiment indicated that the dimensions of the receptor–ligand complex have strong effects on the size-dependent exclusion of proteins in cell environments. In this article, a continuum elastic model is constructed to resolve the competition between the dimension of the receptor–ligand complex and depletion effects in the endocytosis of a spherical virus-like bioparticle. Our results show that the depletion effects do not alwaysmore » assist endocytosis of a spherical virus-like bioparticle; while the dimension of the ligand–receptor complex is larger than the size of a small bioparticle in cell environments, the depletion effects do not work and reverse effects appear. The ligand density covered on the virus can be identified quantitatively.« less

Roughness threshold for cell attachment and proliferation on plasma micro-nanotextured polymeric surfaces: the case of primary human skin fibroblasts and mouse immortalized 3T3 fibroblasts

NASA Astrophysics Data System (ADS)

Bourkoula, A.; Constantoudis, V.; Kontziampasis, D.; Petrou, P. S.; Kakabakos, S. E.; Tserepi, A.; Gogolides, E.

2016-08-01

Poly(methyl methacrylate) surfaces have been micro-nanotextured in oxygen plasmas with increasing ion energy, leading to micro-nanotopography characterized by increased root mean square roughness, correlation length and fractal dimension. Primary human skin fibroblasts and mouse immortalized 3T3 fibroblasts were cultured on these surfaces and the number of adhering cells, their proliferation rate and morphology (cytoplasm and nucleus area) were evaluated as a function of roughness height, correlation length, and fractal dimension. A roughness threshold behavior was observed for both types of cells leading to dramatic cell number decrease above this threshold, which is almost similar for the two types of cells, despite their differences in size and stiffness. The results are discussed based on two theoretical models, which are reconciled and unified when the elastic moduli and the size of the cells are taken into account.

Bicycle Education, A New Dimension in 4-H Programs for 8-11 Year Olds: Designed into Three Teaching Units.

ERIC Educational Resources Information Center

Borst, William H.

The three teaching units in this packet are designed to help children ages 8 to 11 enjoy, utilize, and safely ride bicycles by mastering skills and knowledge pertaining to their bicycles, their driving ability, and the traffic system. Unit I is concerned with the bicycle and its parts, various kinds of bicycles, and proper size and maintenance.…

Molecular cloning of Brevundimonas diminuta for efficacy assessment of reverse osmosis devices.

PubMed

Donofrio, Robert; Saha, Ratul; Bestervelt, Lori; Bagley, Susan

2012-06-01

Brevundimonas diminuta is the test organism specified in the United States Environmental Protection Agency's (USEPA) reverse osmosis (RO) treatment device verification protocol. As non-selective growth medium is employed, enumeration of B. diminuta may be impaired due to interference by indigenous heterotrophic bacteria. Thus the microbial removal capability of the filtration system may be incorrectly assessed. As these treatment devices are used in emergency situations, the health of the public could be compromised. The objective of this study was to develop selective approaches for enumerating viable B. diminuta in test water. Two molecular approaches were investigated: expression of a kanamycin resistance gene and expression of a fluorescent protein gene. The USEPA protocol specifies a 0.3 μm cell size, so the expression of the selective markers were assessed following growth on media designed to induce this small cell diameter. The kan(R) strain was demonstrated to be equivalent to the wild type in cell dimension and survival following exposure to the test water. The kan(R) strain showed equivalent performance to the wild type in the RO protocol indicating that it is a viable alternative surrogate. By utilizing this strain, a more accurate validation of the RO system can be achieved.

Biomaterials for 4D stem cell culture

PubMed Central

Hilderbrand, Amber M.; Ovadia, Elisa M.; Rehmann, Matthew S.; Kharkar, Prathamesh M.; Guo, Chen; Kloxin, April M.

2017-01-01

Stem cells reside in complex three-dimensional (3D) environments within the body that change with time, promoting various cellular functions and processes such as migration and differentiation. These complex changes in the surrounding environment dictate cell fate yet, until recently, have been challenging to mimic within cell culture systems. Hydrogel-based biomaterials are well suited to mimic aspects of these in vivo environments, owing to their high water content, soft tissue-like elasticity, and often-tunable biochemical content. Further, hydrogels can be engineered to achieve changes in matrix properties over time to better mimic dynamic native microenvironments for probing and directing stem cell function and fate. This review will focus on techniques to form hydrogel-based biomaterials and modify their properties in time during cell culture using select addition reactions, cleavage reactions, or non-covalent interactions. Recent applications of these techniques for the culture of stem cells in four dimensions (i.e., in three dimensions with changes over time) also will be discussed for studying essential stem cell processes. PMID:28717344

Synthesis of strongly fluorescent molybdenum disulfide nanosheets for cell-targeted labeling.

PubMed

Wang, Nan; Wei, Fang; Qi, Yuhang; Li, Hongxiang; Lu, Xin; Zhao, Guoqiang; Xu, Qun

2014-11-26

MoS2 nanosheets with polydispersity of the lateral dimensions from natural mineral molybdenite have been prepared in the emulsions microenvironment built by the water/surfactant/CO2 system. The size, thickness, and atomic structure are characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), and laser-scattering particle size analysis. Meanwhile, by the analysis of photoluminescence spectroscopy and microscope, the MoS2 nanosheets with smaller lateral dimensions exhibit extraordinary photoluminescence properties different from those with relatively larger lateral dimensions. The discovery of the excitation dependent photoluminescence for MoS2 nanosheets makes them potentially of interests for the applications in optoelectronics and biology. Moreover, we demonstrate that the fabricated MoS2 nanosheets can be a nontoxic fluorescent label for cell-targeted labeling application.

Distance Higher Education Experiences of Arab Gulf Students in the United States: A Cultural Perspective

ERIC Educational Resources Information Center

Al-Harthi, Aisha S.

2005-01-01

This article reports on a phenomenological research study that was undertaken to provide cultural understanding about the nature of distance education experiences of Arab graduate students pursuing degree programs in the United States. As a theoretical framework, Hofstede's international difference dimensions and Hall's concept of low and high…

U.S. Media and Thai Society.

ERIC Educational Resources Information Center

Thongprayoon, Boonchan; Hill, L. Brooks

A study investigated the effects of U.S. mass media on three dimensions of Thai society: lifestyles, social problems, and value conflict. A total of 100 two-part questionnaires were distributed to Thai students at southwestern public universities in the United States. Forty males and 28 females, whose lengths of stay in the United States varied…

Lived Body Knowledge: Disciplinary Knowledge for Preservice Physical Education Teachers

ERIC Educational Resources Information Center

Johnson, Tyler G.

2015-01-01

The American Kinesiology Association has constructed an undergraduate core for degree programs that reside in kinesiology-based academic units. Since many Physical Education Teacher Education programs are housed in such units, there is a need to prioritize the areas of the undergraduate core, particularly the place of the scientific dimensions of…

Organisational Culture and Values and the Adaptation of Academic Units in Australian Universities

ERIC Educational Resources Information Center

de Zilwa, Deanna

2007-01-01

This study explores connections between the organisational culture and values of academic units in Australian universities and their efforts to adapt to external environmental pressures. It integrates empirical findings from case studies with theories of organisational culture and values and adaptation. It identifies seven dimensions of academic…

A Comparison of Geometry Problems in Middle-Grade Mathematics Textbooks from Taiwan, Singapore, Finland, and the United States

ERIC Educational Resources Information Center

Yang, Der-Ching; Tseng, Yi-Kuan; Wang, Tzu-Ling

2017-01-01

This study analyzed geometry problems in four middle-grade mathematics textbook series from Taiwan, Singapore, Finland, and the United States, while exploring the expectations for students' learning experiences with these problems. An analytical framework developed for mathematics textbook problem analysis had three dimensions: representation…

Economic Objects: How Policy Discourse in the United Kingdom Represents International Students

ERIC Educational Resources Information Center

Lomer, Sylvie

2014-01-01

Despite the significant and increasing presence of international students in the United Kingdom, on a national level there has been a lack of formal policy towards international students. Instead, in policy discourse, international students are represented in economic terms to the exclusion of other dimensions of experience and action. This…

Human dimensions of early successional landscapes in the eastern United States

Treesearch

Paul H. Gobster

2001-01-01

People interactions wit early successional landscapes are varied and diverse. I review 3 key ways thta people perceive, use, and value forest landscapes, emphasizing selected types of early successional landscapes in the eastern United States(U.S.): production and comsumption of timber and nontimber forest products, visual and aesthetic perceptions , and recreational...

Heterogeneity in iota-carrageenan molecular structure: insights for polymorph II→III transition in the presence of calcium ions

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

Janaswamy, Srinivas; Chandrasekaran, Rengaswami

2008-06-24

Iota-carrageenan is used in pharmaceutical and food applications due to its ability to complex with other hydrocolloids and proteins. Six distinct cation dependent allomorphs, consistent with its versatile functionality, have so far been observed in the solid state. In this contribution, X-ray structural details of calcium iota-carrageenan (form III) are reported. The polysaccharide retains the half-staggered, parallel, 3-fold, right-handed double helix stabilized by interchain hydrogen bonds from O-2H and O-6H in the Galp units. Results show that there are four helices, rather than one in I or three in II, organized in a larger pseudo-trigonal unit cell of dimensions a=27.44,more » c=13.01 A, and gamma=120 degrees . The four helices have similar core structures, but their sulfate group orientations are quite different. Fifteen calcium ions and 64 water molecules hold the helices together and promote helix-helix interactions. The results portray how the helices would shuffle around in an orchestrated manner to yield calcium iota-carrageenan III from II.« less

Crystallization and preliminary X-ray crystallographic analysis of a carbonyl reductase from Candida parapsilosis

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

Zhang, Rongzhen; Xu, Yan, E-mail: biosean@yahoo.com.cn; Sun, Ying

2008-04-01

A novel short-chain NADPH-dependent (S)-1-phenyl-1,2-ethanediol dehydrogenase (SCR) has been crystallized. A novel short-chain NADPH-dependent (S)-1-phenyl-1,2-ethanediol dehydrogenase (SCR) has been crystallized. Two distinct but related crystal forms of SCR were obtained using the hanging-drop vapour-diffusion method and a reservoir solution consisting of 18%(w/v) polyethylene glycol 2000 monomethyl ether and 8%(v/v) 2-propanol as the precipitant. The crystals were rhomboid in shape with average dimensions of 0.3 × 0.3 × 0.4 mm and diffracted to a resolution of 2.7–3.0 Å. The crystal forms both belong to space group P2{sub 1}2{sub 1}2{sub 1} and have unit-cell parameters a = 104.7, b = 142.8, cmore » = 151.8 Å and a = 101.1, b = 146.0, c = 159.8 Å. The calculated values of V{sub M}, rotation-function and translation-function solutions and consideration of potential crystal packing suggest that there are eight protein subunits per asymmetric unit.« less

Photovoltaic Performance Characterization of Textured Silicon Solar Cells Using Luminescent Down-Shifting Eu-Doped Phosphor Particles of Various Dimensions.

PubMed

Ho, Wen-Jeng; Deng, Yu-Jie; Liu, Jheng-Jie; Feng, Sheng-Kai; Lin, Jian-Cheng

2017-01-01

This paper reports on efforts to enhance the photovoltaic performance of textured silicon solar cells through the application of a layer of Eu-doped silicate phosphor with particles of various dimensions using the spin-on film technique. We examined the surface profile and dimensions of the Eu-doped phosphors in the silicate layer using optical microscopy with J-image software. Optical reflectance, photoluminescence, and external quantum efficiency were used to characterize the luminescent downshifting (LDS) and light scattering of the Eu-doped silicate phosphor layer. Current density-voltage curves under AM 1.5G simulation were used to confirm the contribution of LDS and light scattering produced by phosphor particles of various dimensions. Experiment results reveal that smaller phosphor particles have a more pronounced effect on LDS and a slight shading of incident light. The application of small Eu-doped phosphor particles increased the conversion efficiency by 9.2% (from 12.56% to 13.86%), far exceeding the 5.6% improvement (from 12.54% to 13.32%) achieved by applying a 250 nm layer of SiO₂ and the 4.5% improvement (from 12.37% to 12.98%) observed in cells with large Eu-doped phosphor particles.

Photovoltaic Performance Characterization of Textured Silicon Solar Cells Using Luminescent Down-Shifting Eu-Doped Phosphor Particles of Various Dimensions

PubMed Central

Ho, Wen-Jeng; Deng, Yu-Jie; Liu, Jheng-Jie; Feng, Sheng-Kai; Lin, Jian-Cheng

2017-01-01

This paper reports on efforts to enhance the photovoltaic performance of textured silicon solar cells through the application of a layer of Eu-doped silicate phosphor with particles of various dimensions using the spin-on film technique. We examined the surface profile and dimensions of the Eu-doped phosphors in the silicate layer using optical microscopy with J-image software. Optical reflectance, photoluminescence, and external quantum efficiency were used to characterize the luminescent downshifting (LDS) and light scattering of the Eu-doped silicate phosphor layer. Current density-voltage curves under AM 1.5G simulation were used to confirm the contribution of LDS and light scattering produced by phosphor particles of various dimensions. Experiment results reveal that smaller phosphor particles have a more pronounced effect on LDS and a slight shading of incident light. The application of small Eu-doped phosphor particles increased the conversion efficiency by 9.2% (from 12.56% to 13.86%), far exceeding the 5.6% improvement (from 12.54% to 13.32%) achieved by applying a 250 nm layer of SiO2 and the 4.5% improvement (from 12.37% to 12.98%) observed in cells with large Eu-doped phosphor particles. PMID:28772384

The dimensions and characteristics of the subepidermal nerve plexus in human skin--terminal Schwann cells constitute a substantial cell population within the superficial dermis.

PubMed

Reinisch, Christina M; Tschachler, Erwin

2012-03-01

The skin constitutes the largest sensorial organ. Its nervous system consists of different types of afferent nerve fibers which spread out immediately beneath the skin surface to sense temperature, touch and pain. Our aim was to investigate the dimension and topographic relationship of the different nerve fibers of the subepidermal nerve plexus in human hairy skin and to analyze numbers and marker expression of terminal Schwann cells. Nerve fibers and Schwann cells were investigated on dermal sheet preparations and thick sections of skin from various body regions of 10 individuals. The dimension of subepidermal nerve fibers varied between different body sites with highest values in chest skin (100 ± 18 mm/mm(2)) and lowest in posterior forearm skin (53 ± 10 mm/mm(2)). The majority of fibers (85.79%) were unmyelinated, thus representing C-fibers, of which 7.84% were peptidergic. Neurofilament-positive fibers (A-fibers) accounted for 14.21% and fibers positive for both neurofilament and myelin (Aβ-fibers) for only 0.18%. The number of Schwann cells varied in accordance with nerve fiber length from 453 ± 108 on chest skin to 184 ± 58/mm(2) in skin of the posterior forearm. Terminal Schwann cells showed a marker profile comparable to Schwann cells in peripheral nerves with the notable exception of expression of NGFr, NCAM, L1CAM and CD146 on myelinating Schwann cells in the dermis but not in peripheral nerves. Our data show that terminal Schwann cells constitute a substantial cell population within the papillary dermis and that both nerve fiber length and Schwann cell numbers vary considerably between different body sites. Copyright © 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

PCA-HOG symmetrical feature based diseased cell detection

NASA Astrophysics Data System (ADS)

Wan, Min-jie

2016-04-01

A histogram of oriented gradient (HOG) feature is applied to the field of diseased cell detection, which can detect diseased cells in high resolution tissue images rapidly, accurately and efficiently. Firstly, motivated by symmetrical cellular forms, a new HOG symmetrical feature based on the traditional HOG feature is proposed to meet the condition of cell detection. Secondly, considering the high feature dimension of traditional HOG feature leads to plenty of memory resources and long runtime in practical applications, a classical dimension reduction method called principal component analysis (PCA) is used to reduce the dimension of high-dimensional HOG descriptor. Because of that, computational speed is increased greatly, and the accuracy of detection can be controlled in a proper range at the same time. Thirdly, support vector machine (SVM) classifier is trained with PCA-HOG symmetrical features proposed above. At last, practical tissue images is detected and analyzed by SVM classifier. In order to verify the effectiveness of this new algorithm, it is practically applied to conduct diseased cell detection which takes 200 pieces of H&E (hematoxylin & eosin) high resolution staining histopathological images collected from 20 breast cancer patients as a sample. The experiment shows that the average processing rate can be 25 frames per second and the detection accuracy can be 92.1%.

Cell phone use while driving in North Carolina

DOT National Transportation Integrated Search

2001-11-01

This study explored several dimensions of the growing trend of talking on a cell phone while driving. It did so by (1) reviewing the recent research epidemiological studies; case analyses of cell phone-related crashes; and driver performance studies;...

Floral nectar production and carbohydrate composition and the structure of receptacular nectaries in the invasive plant Bunias orientalis L. (Brassicaceae).

PubMed

Denisow, Bożena; Masierowska, Marzena; Antoń, Sebastian

2016-11-01

The data relating to the nectaries and nectar secretion in invasive Brassicacean taxa are scarce. In the present paper, the nectar production and nectar carbohydrate composition as well as the morphology, anatomy and ultrastructure of the floral nectaries in Bunias orientalis were investigated. Nectary glands were examined using light, fluorescence, scanning electron and transmission electron microscopy. The quantities of nectar produced by flowers and total sugar mass in nectar were relatively low. Total nectar carbohydrate production per 10 flowers averaged 0.3 mg. Nectar contained exclusively glucose (G) and fructose (F) with overall G/F ratio greater than 1. The flowers of B. orientalis have four nectaries placed at the base of the ovary. The nectarium is intermediate between two nectary types: the lateral and median nectary type (lateral and median glands stay separated) and the annular nectary type (both nectaries are united into one). Both pairs of glands represent photosynthetic type and consist of epidermis and glandular tissue. However, they differ in their shape, size, secretory activity, dimensions of epidermal and parenchyma cells, thickness of secretory parenchyma, phloem supply, presence of modified stomata and cuticle ornamentation. The cells of nectaries contain dense cytoplasm, plastids with starch grains and numerous mitochondria. Companion cells of phloem lack cell wall ingrowths. The ultrastructure of secretory cells indicates an eccrine mechanism of secretion. Nectar is exuded throughout modified stomata.

Quantitative characterization of 3D deformations of cell interactions with soft biomaterials

NASA Astrophysics Data System (ADS)

Franck, Christian

In recent years, the importance of mechanical forces in directing cellular function has been recognized as a significant factor in biological and physiological processes. In fact, these physical forces are now viewed equally as important as biochemical stimuli in controlling cellular response. Not only do these cellular forces, or cell tractions, play an important role in cell migration, they are also significant to many other physiological and pathological processes, both at the tissue and organ level, including wound healing, inflammation, angiogenesis, and embryogenesis. A complete quantification of cell tractions during cell-material interactions can lead to a deeper understanding of the fundamental role these forces play in cell biology. Thus, understanding the function and role of a cell from a mechanical framework can have important implications towards the development of new implant materials and drug treatments. Previous research has contributed significant descriptions of cell-tissue interactions by quantifying cell tractions in two-dimensional environments; however, most physiological processes are three-dimensional in nature. Recent studies have shown morphological differences in cells cultured on two-dimensional substrates versus three-dimensional matrices, and that the intrinsic extracellular matrix interactions and migration behavior are different in three dimensions versus two dimensions. Hence, measurement techniques are needed to investigate cellular behavior in all three dimensions. This thesis presents a full-field imaging technique capable of quantitatively measuring cell traction forces in all three spatial dimensions, and hence addresses the need of a three-dimensional quantitative imaging technique to gain insight into the fundamental role of physical forces in biological processes. The technique combines laser scanning confocal microscopy (LSCM) with digital volume correlation (DVC) to track the motion of fluorescent particles during cell-induced or externally applied deformations. This method is validated by comparing experimentally measured non-uniform deformation fields near hard and soft spherical inclusions under uniaxial compression with the corresponding analytical solution. Utilization of a newly developed computationally efficient stretch-correlation and deconvolution algorithm is shown to improve the overall measurement accuracy, in particular under large deformations. Using this technique, the full three-dimensional substrate displacement fields are experimentally determined during the migration of individual fibroblast cells on polyacrylamide gels. This is the first study to show the highly three-dimensional structure of cell-induced displacement and traction fields. These new findings suggest a three-dimensional push-pull cell motility, which differs from the traditional theories based on two-dimensional data. These results provide new insight into the dynamic cell-matrix force exchange or mechanotransduction of migrating cells, and will aid in the development of new three-dimensional cell motility and adhesion models. As this study reveals, the mechanical interactions of cells and their extracellular matrix appear to be highly three-dimensional. It also shows that the LSCM-DVC technique is well suited for investigating the mechanics of cell-matrix interactions while providing a platform to access detailed information of the intricate biomechanical coupling for many cellular responses. Thus, this method has the capability to provide direct quantitative experimental data showing how cells interact with their surroundings in three dimensions and might stimulate new avenues of scientific thought in understanding the fundamental role physical forces play in regulating cell behavior.

A nationwide hospital survey on patient safety culture in Belgian hospitals: setting priorities at the launch of a 5-year patient safety plan.

PubMed

Vlayen, Annemie; Hellings, Johan; Claes, Neree; Peleman, Hilde; Schrooten, Ward

2012-09-01

To measure patient safety culture in Belgian hospitals and to examine the homogeneous grouping of underlying safety culture dimensions. The Hospital Survey on Patient Safety Culture was distributed organisation-wide in 180 Belgian hospitals participating in the federal program on quality and safety between 2007 and 2009. Participating hospitals were invited to submit their data to a comparative database. Homogeneous groups of underlying safety culture dimensions were sought by hierarchical cluster analysis. 90 acute, 42 psychiatric and 11 long-term care hospitals submitted their data for comparison to other hospitals. The benchmark database included 55 225 completed questionnaires (53.7% response rate). Overall dimensional scores were low, although scores were found to be higher for psychiatric and long-term care hospitals than for acute hospitals. The overall perception of patient safety was lower in French-speaking hospitals. Hierarchical clustering of dimensions resulted in two distinct clusters. Cluster I grouped supervisor/manager expectations and actions promoting safety, organisational learning-continuous improvement, teamwork within units and communication openness, while Cluster II included feedback and communication about error, overall perceptions of patient safety, non-punitive response to error, frequency of events reported, teamwork across units, handoffs and transitions, staffing and management support for patient safety. The nationwide safety culture assessment confirms the need for a long-term national initiative to improve patient safety culture and provides each hospital with a baseline patient safety culture profile to direct an intervention plan. The identification of clusters of safety culture dimensions indicates the need for a different approach and context towards the implementation of interventions aimed at improving the safety culture. Certain clusters require unit level improvements, whereas others demand a hospital-wide policy.

Full-field Strain Methods for Investigating Failure Mechanisms in Triaxial Braided Composites

NASA Technical Reports Server (NTRS)

Littell, Justin D.; Binienda, Wieslaw K.; Goldberg, Robert K.; Roberts, Gary D.

2008-01-01

Composite materials made with triaxial braid architecture and large tow size carbon fibers are beginning to be used in many applications, including composite aircraft and engine structures. Recent advancements in braiding technology have led to commercially viable manufacturing approaches for making large structures with complex shape. Although the large unit cell size of these materials is an advantage for manufacturing efficiency, the fiber architecture presents some challenges for materials characterization, design, and analysis. In some cases, the static load capability of structures made using these materials has been higher than expected based on material strength properties measured using standard coupon tests. A potential problem with using standard tests methods for these materials is that the unit cell size can be an unacceptably large fraction of the specimen dimensions. More detailed investigation of deformation and failure processes in large unit cell size triaxial braid composites is needed to evaluate the applicability of standard test methods for these materials and to develop alternative testing approaches. In recent years, commercial equipment has become available that enables digital image correlation to be used on a more routine basis for investigation of full field 3D deformation in materials and structures. In this paper, some new techniques that have been developed to investigate local deformation and failure using digital image correlation techniques are presented. The methods were used to measure both local and global strains during standard straight-sided coupon tensile tests on composite materials made with 12 and 24 k yarns and a 0/+60/-60 triaxial braid architecture. Local deformation and failure within fiber bundles was observed, and this local failure had a significant effect on global stiffness and strength. The matrix material had a large effect on local damage initiation for the two matrix materials used in this investigation. Premature failure in regions of the unit cell near the edge of the straight-sided specimens was observed for transverse tensile tests in which the braid axial fibers were perpendicular to the specimen axis and the bias fibers terminated on the cut edges in the specimen gage section. This edge effect is one factor that could contribute to a measured strength that is lower than the actual material strength in a structure without edge effects.

The development of computer-aided system for tissue scaffolds (CASTS) system for functionally graded tissue-engineering scaffolds.

PubMed

Sudarmadji, Novella; Chua, Chee Kai; Leong, Kah Fai

2012-01-01

Computer-aided system for tissue scaffolds (CASTS) is an in-house parametric library of polyhedral units that can be assembled into customized tissue scaffolds. Thirteen polyhedral configurations are available to select, depending on the biological and mechanical requirements of the target tissue/organ. Input parameters include the individual polyhedral units and overall scaffold block as well as the scaffold strut diameter. Taking advantage of its repeatability and reproducibility, the scaffold file is then converted into .STL file and fabricated using selective laser sintering, a rapid prototyping system. CASTS seeks to fulfill anatomical, biological, and mechanical requirements of the target tissue/organ. Customized anatomical scaffold shape is achieved through a Boolean operation between the scaffold block and the tissue defect image. Biological requirements, such as scaffold pore size and porosity, are unique for different type of cells. Matching mechanical properties, such as stiffness and strength, between the scaffold and target organ is very important, particularly in the regeneration of load-bearing organ, i.e., bone. This includes mimicking the compressive stiffness variation across the bone to prevent stress shielding and ensuring that the scaffold can withstand the load normally borne by the bone. The stiffness variation is tailored by adjusting the scaffold porosity based on the porosity-stiffness relationship of the CASTS scaffolds. Two types of functional gradients based on the gradient direction include radial and axial/linear gradient. Radial gradient is useful in the case of regenerating a section of long bones while the gradient in linear direction can be used in short or irregular bones. Stiffness gradient in the radial direction is achieved by using cylindrical unit cells arranged in a concentric manner, in which the porosity decreases from the center of the structure toward the outside radius, making the scaffold stiffer at the outer radius and more porous at the center of the scaffold. On the other hand, the linear gradient is accomplished by varying the strut diameter along the gradient direction. The parameters to vary in both gradient types are the strut diameter, the unit cell dimension, and the boundaries between two scaffold regions with different stiffness.

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.

Effect of water stress on cotton leaves : I. An electron microscopic stereological study of the palisade cells.

PubMed

Berlin, J; Quisenberry, J E; Bailey, F; Woodworth, M; McMichael, B L

1982-07-01

Palisade cells from fully expanded leaves from irrigated and nonirrigated, field grown cotton (Gossypium hirsutum L. cv. Paymaster 266) were subjected to a microscopic examination to evaluate the effect of water stress on subcellular structures. The water potential difference between the two treatments was 13 bars at the time of sampling. The dimensions of the palisade cells and their density per unit leaf area were determined by light microscopy. Palisade cells from stressed plants had the same diameter, but were taller than their counterparts in irrigated plants. The density of the palisade cells was the same in both treatments as was the fractional volume of the intercellular space. It was concluded that the reduced leaf area observed in the stressed plants resulted primarily from a mitotic sensitivity to water stress. Further, expansion of palisade cells was not inhibited by the stress imposed in this study.Morphometric analysis of electron micrographs was used to evaluate the subcellular structure of palisade cells from nonstressed and stressed plants. The fractional volumes of cell walls, total cytoplasm, chloroplasts, starch granules, intrachloroplast bodies, mitochondria, peroxisomes, and central vacuoles were determined. The surface densities of grana and stroma lamellae, outer chloroplast membranes, mitochondrial cristae, endoplasmic reticulum and Golgi cisternae were also measured. The number of chloroplasts, mitochondria, and peroxisomes were determined. These data were expressed as actual volumes, areas, and numbers per palisade cell for each treatment. Palisade cells from stressed plants had thinner cell walls, larger central vacuoles and approximately the same amount of cytoplasm compared to cells from nonstressed plants. Within the cytoplasm, stressed plants had more but smaller chloroplasts with increased grana and stroma lamellae surfaces, larger mithchondria with reduced cristae surfaces, smaller peroxisomes and reduced membrane surfaces of endoplasmic reticulum and Golgi cisternae.

Size characteristics of stones ingested by common loons

USGS Publications Warehouse

Franson, J. Christian; Hansen, Scott P.; Pokras, Mark; Miconi, Rose

2001-01-01

Common Loon (Gavia immer) carcasses recovered in New England had more stones of greater combined mass in their stomachs than loons from the southeastern United States. Stones retained in sieves with mesh sizes between 4.75 and 8.00 mm accounted for the greatest percentage (by mass) of grit in loon stomachs. The median longest dimension of the largest single stone in each stomach was 12.5 mm in loons from New England and 10.7 mm in loons from the southeast (maximum = 23.1 mm and 16.8 mm, respectively). A recent national proposal to restrict the use of certain fishing weights in the United States called for a ban on lead fishing sinkers of 25.4 mm or less in any dimension. Our findings suggest it is unlikely that Common Loons would ingest lead fishing weights greater than 25.4 mm in any dimension, if such ingestion was solely the result of their search for replacement stones for their stomachs. However, this does not preclude the possibility that loons may ingest larger fishing weights under other circumstances, such as the consumption of fish with attached sinkers.

Continuity of care from the perspective of users.

PubMed

Mendes, Felismina Rosa P; Gemito, Maria Laurência G Parreirinha; Caldeira, Ermelinda do Carmo; Serra, Isaura da Conceição; Casas-Novas, Maria Vitória

2017-03-01

Continuity of care, in addition to ensuring improvement of the quality of care, contributes to the reduction of health costs. The objective of this study was to analyse the continuity of care in health units in the municipality of Évora (south of Portugal), from the perspective of users. This is across-sectional, exploratory and descriptive study with a quantitative approach, with a sample consisting of 342 users of health units. The instrument was a questionnaire adapted from English and Spanish studies. The results show that elements of continuity were identified in the different dimensions of the continuity of care - relational, management, information and some items of flexible continuity. Longitudinal continuity has the lowest values in nursing care. In conclusion, what stands out positively, and in its different dimensions, is relational continuity, in which most users recommend their family doctor and nurse to family and friends, and flexible continuity, which translates into reduced waiting times to be attended by a doctor or nurse and access to care. What stands out negatively is the weak involvement of the user in care by health professionals, in the dimensions of relational continuity.

Criterion learning in rule-based categorization: Simulation of neural mechanism and new data

PubMed Central

Helie, Sebastien; Ell, Shawn W.; Filoteo, J. Vincent; Maddox, W. Todd

2015-01-01

In perceptual categorization, rule selection consists of selecting one or several stimulus-dimensions to be used to categorize the stimuli (e.g, categorize lines according to their length). Once a rule has been selected, criterion learning consists of defining how stimuli will be grouped using the selected dimension(s) (e.g., if the selected rule is line length, define ‘long’ and ‘short’). Very little is known about the neuroscience of criterion learning, and most existing computational models do not provide a biological mechanism for this process. In this article, we introduce a new model of rule learning called Heterosynaptic Inhibitory Criterion Learning (HICL). HICL includes a biologically-based explanation of criterion learning, and we use new category-learning data to test key aspects of the model. In HICL, rule selective cells in prefrontal cortex modulate stimulus-response associations using pre-synaptic inhibition. Criterion learning is implemented by a new type of heterosynaptic error-driven Hebbian learning at inhibitory synapses that uses feedback to drive cell activation above/below thresholds representing ionic gating mechanisms. The model is used to account for new human categorization data from two experiments showing that: (1) changing rule criterion on a given dimension is easier if irrelevant dimensions are also changing (Experiment 1), and (2) showing that changing the relevant rule dimension and learning a new criterion is more difficult, but also facilitated by a change in the irrelevant dimension (Experiment 2). We conclude with a discussion of some of HICL’s implications for future research on rule learning. PMID:25682349

Measuring surface topography by scanning electron microscopy. II. Analysis of three estimators of surface roughness in second dimension and third dimension.

PubMed

Bonetto, Rita Dominga; Ladaga, Juan Luis; Ponz, Ezequiel

2006-04-01

Scanning electron microscopy (SEM) is widely used in surface studies and continuous efforts are carried out in the search of estimators of different surface characteristics. By using the variogram, we developed two of these estimators that were used to characterize the surface roughness from the SEM image texture. One of the estimators is related to the crossover between fractal region at low scale and the periodic region at high scale, whereas the other estimator characterizes the periodic region. In this work, a full study of these estimators and the fractal dimension in two dimensions (2D) and three dimensions (3D) was carried out for emery papers. We show that the obtained fractal dimension with only one image is good enough to characterize the roughness surface because its behavior is similar to those obtained with 3D height data. We show also that the estimator that indicates the crossover is related to the minimum cell size in 2D and to the average particle size in 3D. The other estimator has different values for the three studied emery papers in 2D but it does not have a clear meaning, and these values are similar for those studied samples in 3D. Nevertheless, it indicates the formation tendency of compound cells. The fractal dimension values from the variogram and from an area versus step log-log graph were studied with 3D data. Both methods yield different values corresponding to different information from the samples.

Criterion learning in rule-based categorization: simulation of neural mechanism and new data.

PubMed

Helie, Sebastien; Ell, Shawn W; Filoteo, J Vincent; Maddox, W Todd

2015-04-01

In perceptual categorization, rule selection consists of selecting one or several stimulus-dimensions to be used to categorize the stimuli (e.g., categorize lines according to their length). Once a rule has been selected, criterion learning consists of defining how stimuli will be grouped using the selected dimension(s) (e.g., if the selected rule is line length, define 'long' and 'short'). Very little is known about the neuroscience of criterion learning, and most existing computational models do not provide a biological mechanism for this process. In this article, we introduce a new model of rule learning called Heterosynaptic Inhibitory Criterion Learning (HICL). HICL includes a biologically-based explanation of criterion learning, and we use new category-learning data to test key aspects of the model. In HICL, rule selective cells in prefrontal cortex modulate stimulus-response associations using pre-synaptic inhibition. Criterion learning is implemented by a new type of heterosynaptic error-driven Hebbian learning at inhibitory synapses that uses feedback to drive cell activation above/below thresholds representing ionic gating mechanisms. The model is used to account for new human categorization data from two experiments showing that: (1) changing rule criterion on a given dimension is easier if irrelevant dimensions are also changing (Experiment 1), and (2) showing that changing the relevant rule dimension and learning a new criterion is more difficult, but also facilitated by a change in the irrelevant dimension (Experiment 2). We conclude with a discussion of some of HICL's implications for future research on rule learning. Copyright © 2015 Elsevier Inc. All rights reserved.

Revisiting special relativity: a natural algebraic alternative to Minkowski spacetime.

PubMed

Chappell, James M; Iqbal, Azhar; Iannella, Nicolangelo; Abbott, Derek

2012-01-01

Minkowski famously introduced the concept of a space-time continuum in 1908, merging the three dimensions of space with an imaginary time dimension [Formula: see text], with the unit imaginary producing the correct spacetime distance [Formula: see text], and the results of Einstein's then recently developed theory of special relativity, thus providing an explanation for Einstein's theory in terms of the structure of space and time. As an alternative to a planar Minkowski space-time of two space dimensions and one time dimension, we replace the unit imaginary [Formula: see text], with the Clifford bivector [Formula: see text] for the plane that also squares to minus one, but which can be included without the addition of an extra dimension, as it is an integral part of the real Cartesian plane with the orthonormal basis [Formula: see text] and [Formula: see text]. We find that with this model of planar spacetime, using a two-dimensional Clifford multivector, the spacetime metric and the Lorentz transformations follow immediately as properties of the algebra. This also leads to momentum and energy being represented as components of a multivector and we give a new efficient derivation of Compton's scattering formula, and a simple formulation of Dirac's and Maxwell's equations. Based on the mathematical structure of the multivector, we produce a semi-classical model of massive particles, which can then be viewed as the origin of the Minkowski spacetime structure and thus a deeper explanation for relativistic effects. We also find a new perspective on the nature of time, which is now given a precise mathematical definition as the bivector of the plane.

Revisiting Special Relativity: A Natural Algebraic Alternative to Minkowski Spacetime

PubMed Central

Chappell, James M.; Iqbal, Azhar; Iannella, Nicolangelo; Abbott, Derek

2012-01-01

Minkowski famously introduced the concept of a space-time continuum in 1908, merging the three dimensions of space with an imaginary time dimension , with the unit imaginary producing the correct spacetime distance , and the results of Einstein’s then recently developed theory of special relativity, thus providing an explanation for Einstein’s theory in terms of the structure of space and time. As an alternative to a planar Minkowski space-time of two space dimensions and one time dimension, we replace the unit imaginary , with the Clifford bivector for the plane that also squares to minus one, but which can be included without the addition of an extra dimension, as it is an integral part of the real Cartesian plane with the orthonormal basis and . We find that with this model of planar spacetime, using a two-dimensional Clifford multivector, the spacetime metric and the Lorentz transformations follow immediately as properties of the algebra. This also leads to momentum and energy being represented as components of a multivector and we give a new efficient derivation of Compton’s scattering formula, and a simple formulation of Dirac’s and Maxwell’s equations. Based on the mathematical structure of the multivector, we produce a semi-classical model of massive particles, which can then be viewed as the origin of the Minkowski spacetime structure and thus a deeper explanation for relativistic effects. We also find a new perspective on the nature of time, which is now given a precise mathematical definition as the bivector of the plane. PMID:23300566

High speed CMOS/SOS standard cell notebook

NASA Technical Reports Server (NTRS)

1978-01-01

The NASA/MSFC high speed CMOS/SOS standard cell family, designed to be compatible with the PR2D (Place, Route in 2-Dimensions) automatic layout program, is described. Standard cell data sheets show the logic diagram, the schematic, the truth table, and propagation delays for each logic cell.

Universal, developmental, and variable aspects of young children's play: a cross-cultural comparison of pretending at home.

PubMed

Haight, W L; Wang, X L; Fung, H H; Williams, K; Mintz, J

1999-01-01

Using longitudinal data from five Irish American families in the United States and nine Chinese families in Taiwan, in conjunction with an emerging body of evidence in the cultural psychology literature, we propose universal, culturally variable, and developmental dimensions of young children's pretend play. Possible universal dimensions include the use of objects, and the predominantly social nature of pretend play. Developmental dimensions include increases in the proportion of social pretend play initiated by the child, the proportion of partner initiations elaborated upon by the child, and caregivers' use of pretend play initiations to serve other, nonplay social functions. Culturally variable dimensions include the centrality of objects, the participation of specific play partners, the extent of child initiations of social pretend play with caregivers, the various functions of social pretend play in interaction, and specific themes. These findings raise the theoretical issue of how universal and variable dimensions of pretend play interact in specific communities to create distinctive development pathways.

Measuring Contextual Characteristics for Community Health

PubMed Central

Hillemeier, Marianne M; Lynch, John; Harper, Sam; Casper, Michele

2003-01-01

Objective To conceptualize and measure community contextual influences on population health and health disparities. Data Sources We use traditional and nontraditional secondary sources of data comprising a comprehensive array of community characteristics. Study Design Using a consultative process, we identify 12 overarching dimensions of contextual characteristics that may affect community health, as well as specific subcomponents relating to each dimension. Data Collection An extensive geocoded library of data indicators relating to each dimension and subcomponent for metropolitan areas in the United States is assembled. Principal Findings We describe the development of community contextual health profiles, present the rationale supporting each of the profile dimensions, and provide examples of relevant data sources. Conclusions Our conceptual framework for community contextual characteristics, including a specified set of dimensions and components, can provide practical ways to monitor health-related aspects of the economic, social, and physical environments in which people live. We suggest several guiding principles useful for understanding how aspects of contextual characteristics can affect health and health disparities. PMID:14727793

Introducing Blended Learning: An Experience of Uncertainty for Students in the United Arab Emirates

ERIC Educational Resources Information Center

Kemp, Linzi J.

2013-01-01

The cultural dimension of Uncertainty Avoidance is analysed in this study of an introduction to blended learning for international students. Content analysis was conducted on the survey narratives collected from three cohorts of management undergraduates in the United Arab Emirates. Interpretation of certainty with blended learning was found in:…

[Quality of life and life project, two inseparable concepts?].

PubMed

Deconstanza, Patrice

2010-01-01

The construction of a life project within a long-stay unit for people living with chronic psychiatric disorders must take into account a dimension of care centred around the quality of life and the care provided "here and now". Here, the concept of care finds its full meaning. The example of a long-stay psychiatric unit.

Participation Structures as a Mediational Means: Learning Balinese Gamelan in the United States through Intent Participation, Mediated Discourse, and Distributed Cognition

ERIC Educational Resources Information Center

Jocuns, Andrew

2009-01-01

Participation has presented a complex unit of analysis for interactional sociolinguistics. In this study I add another dimension to participation by considering recent theories related to sociocultural activity theory--mediated discourse analysis and distributed cognition. Drawing on examples from "maguru panggul", the traditional…

Sexual Trafficking in the United States: A Domestic Problem with Transnational Dimensions

ERIC Educational Resources Information Center

Hodge, David R.

2008-01-01

The trafficking of young women and children for prostitution and other forms of sexual exploitation is one of the most significant human rights abuses in contemporary society. In keeping with the social work profession's commitment to social justice, this article examines the issue of sexual trafficking in the United States. The transnational…

Packing in Two and Three Dimensions

DTIC Science & Technology

2003-06-01

square on the pallet is either completely covered or uncovered by a box. We first observe there must be at least one unit column with zero waste because...66 ( , , , , )EW N X Y a b X′ ′ ′ ′ ′ ′< . Any such unit column with zero waste must be covered with H-boxes because this corresponds to the

Toward a Working Model for the Analysis of Cohesion and Coherence in Writing.

ERIC Educational Resources Information Center

Marzano, Robert J.

Although most models of connected discourse are strikingly similar in the types of relationships they describe, they are strikingly different in two areas: the unit of analysis and the dimensions on which cohesion versus coherence are described. Common systems for analyzing written text use the sentence, T-unit, clause, or proposition as the unit…

An emerging paradigm for managing protected areas with examples from Europe and the United States

Treesearch

James Absher; Carsten Mann

2010-01-01

Parks and Protected Areas (PPA) have become increasingly important for societal well-being in Europe and the United States. Urbanization, detachment from nature, and demographic changes are fostering discussions about strengthening the social and cultural dimensions of management. The complexities and subtleties of incorporating PPAs into existing government and...

Softwood lumber products in the United States: substitutes, complements, or unrelated?

Treesearch

Rao V. Nagubadi; Daowei Zhang; Jeffrey P. Prestemon; David N. Wear

2004-01-01

This study addresses an important dimension concerning the softwood lumber trade dispute between United States and Canada-substitutability among imported and domestically produced species. We employ the restricted translog subcost function approach to study this issue based on the monthly data of US softwood products consumption and prices between Jan. 1989 and July...

Effect of Water Stress on Cotton Leaves 1

PubMed Central

Berlin, Jerry; Quisenberry, J. E.; Bailey, Franklin; Woodworth, Margaret; McMichael, B. L.

1982-01-01

Palisade cells from fully expanded leaves from irrigated and nonirrigated, field grown cotton (Gossypium hirsutum L. cv. Paymaster 266) were subjected to a microscopic examination to evaluate the effect of water stress on subcellular structures. The water potential difference between the two treatments was 13 bars at the time of sampling. The dimensions of the palisade cells and their density per unit leaf area were determined by light microscopy. Palisade cells from stressed plants had the same diameter, but were taller than their counterparts in irrigated plants. The density of the palisade cells was the same in both treatments as was the fractional volume of the intercellular space. It was concluded that the reduced leaf area observed in the stressed plants resulted primarily from a mitotic sensitivity to water stress. Further, expansion of palisade cells was not inhibited by the stress imposed in this study. Morphometric analysis of electron micrographs was used to evaluate the subcellular structure of palisade cells from nonstressed and stressed plants. The fractional volumes of cell walls, total cytoplasm, chloroplasts, starch granules, intrachloroplast bodies, mitochondria, peroxisomes, and central vacuoles were determined. The surface densities of grana and stroma lamellae, outer chloroplast membranes, mitochondrial cristae, endoplasmic reticulum and Golgi cisternae were also measured. The number of chloroplasts, mitochondria, and peroxisomes were determined. These data were expressed as actual volumes, areas, and numbers per palisade cell for each treatment. Palisade cells from stressed plants had thinner cell walls, larger central vacuoles and approximately the same amount of cytoplasm compared to cells from nonstressed plants. Within the cytoplasm, stressed plants had more but smaller chloroplasts with increased grana and stroma lamellae surfaces, larger mithchondria with reduced cristae surfaces, smaller peroxisomes and reduced membrane surfaces of endoplasmic reticulum and Golgi cisternae. Images Fig. 1 PMID:16662453

Time-dependent combinatory effects of active mechanical loading and passive topographical cues on cell orientation.

PubMed

Wang, Qian; Huang, Hanyang; Wei, Kang; Zhao, Yi

2016-10-01

Mechanical stretching and topographical cues are both effective mechanical stimulations for regulating cell morphology, orientation, and behaviors. The competition of these two mechanical stimulations remains largely underexplored. Previous studies have suggested that a small cyclic mechanical strain is not able to reorient cells that have been pre-aligned by relatively large linear microstructures, but can reorient those pre-aligned by small linear micro/nanostructures if the characteristic dimension of these structures is below a certain threshold. Likewise, for micro/nanostructures with a given characteristic dimension, the strain must exceed a certain magnitude to overrule the topographic cues. There are however no in-depth investigations of such "thresholds" due to the lack of close examination of dynamic cell orientation during and shortly after the mechanical loading. In this study, the time-dependent combinatory effects of active and passive mechanical stimulations on cell orientation are investigated by developing a micromechanical stimulator. The results show that the cells pre-aligned by linear micro/nanostructures can be altered by cyclic in-plane strain, regardless of the structure size. During the loading, the micro/nanostructures can resist the reorientation effects by cyclic in-plane strain while the resistive capability (measured by the mean orientation angle change and the reorientation speed) increases with the increasing characteristic dimension. The micro/nanostructures also can recover the cell orientation after the cessation of cyclic in-plane strain, while the recovering capability increases with the characteristic dimension. The previously observed thresholds are largely dependent on the observation time points. In order to accurately evaluate the combinatory effects of the two mechanical stimulations, observations during the active loading with a short time interval or endpoint observations shortly after the loading are preferred. This study provides a microengineering solution to investigate the time-dependent combinatory effects of the active and passive mechanical stimulations and is expected to enhance our understanding of cell responses to complex mechanical environments. Biotechnol. Bioeng. 2016;113: 2191-2201. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

China’s Military Support Facility in Djibouti: The Economic and Security Dimensions of China’s First Overseas Base

DTIC Science & Technology

2017-07-01

Cleared for Public Release China’s Military Support Facility in Djibouti: The Economic and Security Dimensions of China’s...paper provides a preliminary look at the origins of China’s military support facility in Djibouti. It explores the evolution of the economic and security...military facilities abroad. It also assesses the implications of the growing economic and military ties between the two countries for the United

Dimensions of Oppositionality in a Brazilian Community Sample: Testing the DSM-5 Proposal and Etiological Links

PubMed Central

Krieger, Fernanda Valle; Polanczyk, Guilherme Vanoni; Goodman, Robert; Rohde, Luis Augusto; Graeff-Martins, Ana Soledade; Salum, Giovanni; Gadelha, Ary; Pan, Pedro; Stahl, Daniel; Stringaris, Argyris

2013-01-01

Objective Investigating dimensions of oppositional symptoms may help to explain heterogeneity of etiology and outcomes for mental disorders across development and provide further empirical justification for the DSM-5–proposed modifications of oppositional defiant disorder (ODD). However, dimensions of oppositionality have not previously been tested in samples outside Europe or the United States. In this study, we used a large Brazilian community sample to compare the fit of different models for dimensions of oppositional symptoms; to examine the association of psychiatric diagnoses and symptoms with dimensions of oppositionality; and to examine the associations between dimensions of oppositionality and parental history of mental disorders. Method A Brazilian community sample of 2,512 children 6 through 12 years old were investigated in this study. Confirmatory factorial analyses were performed to compare the fit of alternative models, followed by linear and logistic regression analyses of associations with psychiatric diagnosis and parental history of psychopathology. Results A three-factor model with irritable, headstrong, and hurtful dimensions fitted best. The irritable dimension showed a strong association with emotional disorders in the child (p<.001) and history of depression (p<.01) and suicidality (p<.05) in the mother. The headstrong dimension was uniquely associated with attention-deficit/hyperactivity disorder (ADHD) in the child (p<.001) and with maternal history of ADHD symptoms (p<.05). The hurtful dimension was specifically associated with conduct disorder (p< .05). Conclusions Our findings from a large community sample of Brazilian children support a distinction between dimensions of oppositionality consistent with current DSM-5 recommendations and provide further evidence for etiological distinctions between these dimensions. PMID:23582870

Joint Geophysical Inversion With Multi-Objective Global Optimization Methods

NASA Astrophysics Data System (ADS)

Lelievre, P. G.; Bijani, R.; Farquharson, C. G.

2015-12-01

Pareto multi-objective global optimization (PMOGO) methods generate a suite of solutions that minimize multiple objectives (e.g. data misfits and regularization terms) in a Pareto-optimal sense. Providing a suite of models, as opposed to a single model that minimizes a weighted sum of objectives, allows a more complete assessment of the possibilities and avoids the often difficult choice of how to weight each objective. We are applying PMOGO methods to three classes of inverse problems. The first class are standard mesh-based problems where the physical property values in each cell are treated as continuous variables. The second class of problems are also mesh-based but cells can only take discrete physical property values corresponding to known or assumed rock units. In the third class we consider a fundamentally different type of inversion in which a model comprises wireframe surfaces representing contacts between rock units; the physical properties of each rock unit remain fixed while the inversion controls the position of the contact surfaces via control nodes. This third class of problem is essentially a geometry inversion, which can be used to recover the unknown geometry of a target body or to investigate the viability of a proposed Earth model. Joint inversion is greatly simplified for the latter two problem classes because no additional mathematical coupling measure is required in the objective function. PMOGO methods can solve numerically complicated problems that could not be solved with standard descent-based local minimization methods. This includes the latter two classes of problems mentioned above. There are significant increases in the computational requirements when PMOGO methods are used but these can be ameliorated using parallelization and problem dimension reduction strategies.

Cohesin organizes chromatin loops at DNA replication factories

PubMed Central

Guillou, Emmanuelle; Ibarra, Arkaitz; Coulon, Vincent; Casado-Vela, Juan; Rico, Daniel; Casal, Ignacio; Schwob, Etienne; Losada, Ana; Méndez, Juan

2010-01-01

Genomic DNA is packed in chromatin fibers organized in higher-order structures within the interphase nucleus. One level of organization involves the formation of chromatin loops that may provide a favorable environment to processes such as DNA replication, transcription, and repair. However, little is known about the mechanistic basis of this structuration. Here we demonstrate that cohesin participates in the spatial organization of DNA replication factories in human cells. Cohesin is enriched at replication origins and interacts with prereplication complex proteins. Down-regulation of cohesin slows down S-phase progression by limiting the number of active origins and increasing the length of chromatin loops that correspond with replicon units. These results give a new dimension to the role of cohesin in the architectural organization of interphase chromatin, by showing its participation in DNA replication. PMID:21159821

Filling-enforced nonsymmorphic Kondo semimetals in two dimensions

NASA Astrophysics Data System (ADS)

Pixley, J. H.; Lee, SungBin; Brandom, B.; Parameswaran, S. A.

2017-08-01

We study the competition between Kondo screening and frustrated magnetism on the nonsymmorphic Shastry-Sutherland Kondo lattice at a filling of two conduction electrons per unit cell. This model is known to host a set of gapless partially Kondo screened phases intermediate between the Kondo-destroyed paramagnet and the heavy Fermi liquid. Based on crystal symmetries, we argue that (i) both the paramagnet and the heavy Fermi liquid are semimetals protected by a glide symmetry; and (ii) partial Kondo screening breaks the symmetry, removing this protection and allowing the partially Kondo screened phase to be deformed into a Kondo insulator via a Lifshitz transition. We confirm these results using large-N mean-field theory and then use nonperturbative arguments to derive a generalized Luttinger sum rule constraining the phase structure of two-dimensional nonsymmorphic Kondo lattices beyond the mean-field limit.

Synthesis, crystal structure and antioxidant evaluation of C-4-acetamidophenylcalix[4]pyrogallolarene

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

Abosadiya, Hamza M.; Hasbullah, Siti Aishah; Yamin, Bohari M.

2015-09-25

C-4-acetamidophenylcalix[4]pyrogallolarene was synthesized by an acid catalyzed condensation reaction of pyrogallol with 4-acetamidobenzaldehyde. The compound was characterized by IR, {sup 1}H and {sup 13}C NMR spectroscopy. Single crystal X-ray analysis revealed that the molecule crystallized in a triclinic system with space group Pī and the unit cell dimensions a= 12.2948(16) Å, b= 13.4423(17) Å, c= 13.5906(18) Å, α =107.549(4)°, β =102.034(4)°, γ =90.535(4)°, Z= 1 and V= 2088.2(5) Å{sup 3}. The macrocyclic calix adopts a chair (C{sub 2h}) conformation and the molecule is associated with eight DMSO molecules of crystallization. Antioxidant test by DPPH method showed that the compound exhibitsmore » good antioxidant activity of about 72%.« less

Glide-Plane Symmetry and Superconducting Gap Structure of Iron-Based Superconductors

NASA Astrophysics Data System (ADS)

Maier, Thomas

This talk will provide a review of the implications of the glide plane symmetry of a single Fe-pnictide/chalcogen plane on the structure of the superconducting gap. It will be shown that `` η-pairing'' with non-zero total momentum occurs inevitably in this system, but that its contribution to the superconducting condensate has the usual even parity symmetry and time reversal symmetry is preserved. I will demonstrate that for a single plane the gap function, which appears in physical quantities, is identical to that found in 1 Fe per unit cell pseudo-crystal momentum calculations and discuss the effects of the symmetry breaking out-of-plane hopping integrals in three dimensions. A portion of this research was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility.

A New Type of Great Power Relationship Between the United States and China: The Military Dimension

DTIC Science & Technology

2014-09-01

multipolar world system and a pro - spective security and economic partner of the United States. This stands midway between the panda-hug- ging and dragon...actually played different roles in East Asia, from victim to suzerain, from pro - moting the policies of openness and mutual respect characteristic of... Finlandization of Asia would be a profoundly destabilizing development that needs to be deterred. The United States therefore must steer a complex

Determining the Molecular Growth Mechanisms of Protein Crystal Faces by Atomic Force Microscopy

NASA Technical Reports Server (NTRS)

Nadarajah, Arunan; Li, Huayu; Pusey, Marc L.

1999-01-01

A high resolution atomic force microscopy (AFM) study had shown that the molecular packing on the tetragonal lysozyme (110) face corresponded to only one of two possible packing arrangements, suggesting that growth layers on this face were of bimolecular height. Theoretical analyses of the packing also indicated that growth of this face should proceed by the addition of growth units of at least tetramer size corresponding to the 43 helices in the crystal. In this study an AFM linescan technique was devised to measure the dimensions of individual growth units on protein crystal faces as they were being incorporated into the lattice. Images of individual growth events on the (110) face of tetragonal lysozyme crystals were observed, shown by jump discontinuities in the growth step in the linescan images as shown in the figure. The growth unit dimension in the scanned direction was obtained from these images. A large number of scans in two directions on the (110) face were performed and the distribution of lysozyme growth unit sizes were obtained. A variety of unit sizes corresponding to 43 helices, were shown to participate in the growth process, with the 43 tetramer being the minimum observed size. This technique represents a new application for AFM allowing time resolved studies of molecular process to be carried out.

Differentially-dimensioned furrow formation by zygotic gene expression and the MBT

PubMed Central

Xie, Yi

2018-01-01

Despite extensive work on the mechanisms that generate plasma membrane furrows, understanding how cells are able to dynamically regulate furrow dimensions is an unresolved question. Here, we present an in-depth characterization of furrow behaviors and their regulation in vivo during early Drosophila morphogenesis. We show that the deepening in furrow dimensions with successive nuclear cycles is largely due to the introduction of a new, rapid ingression phase (Ingression II). Blocking the midblastula transition (MBT) by suppressing zygotic transcription through pharmacological or genetic means causes the absence of Ingression II, and consequently reduces furrow dimensions. The analysis of compound chromosomes that produce chromosomal aneuploidies suggests that multiple loci on the X, II, and III chromosomes contribute to the production of differentially-dimensioned furrows, and we track the X-chromosomal contribution to furrow lengthening to the nullo gene product. We further show that checkpoint proteins are required for furrow lengthening; however, mitotic phases of the cell cycle are not strictly deterministic for furrow dimensions, as a decoupling of mitotic phases with periods of active ingression occurs as syncytial furrow cycles progress. Finally, we examined the turnover of maternal gene products and find that this is a minor contributor to the developmental regulation of furrow morphologies. Our results suggest that cellularization dynamics during cycle 14 are a continuation of dynamics established during the syncytial cycles and provide a more nuanced view of developmental- and MBT-driven morphogenesis. PMID:29337989

7 CFR 51.1174 - Diameter.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Florida Oranges and Tangelos Definitions § 51.1174 Diameter. Diameter means the greatest dimension measured at right angles to a line from stem...

7 CFR 51.1174 - Diameter.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Florida Oranges and Tangelos Definitions § 51.1174 Diameter. Diameter means the greatest dimension measured at right angles to a line from stem...

7 CFR 51.3152 - Standard pack.

Code of Federal Regulations, 2010 CFR

2010-01-01

... with cell compartments, cardboard fillers or molded trays shall be of the proper size for the cells.... (g) “Diameter” means the greatest dimension measured at right angles to a line from stem to blossom...

7 CFR 51.3152 - Standard pack.

Code of Federal Regulations, 2012 CFR

2012-01-01

... with cell compartments, cardboard fillers or molded trays shall be of the proper size for the cells.... (g) “Diameter” means the greatest dimension measured at right angles to a line from stem to blossom...

7 CFR 51.3152 - Standard pack.

Code of Federal Regulations, 2011 CFR

2011-01-01

... with cell compartments, cardboard fillers or molded trays shall be of the proper size for the cells.... (g) “Diameter” means the greatest dimension measured at right angles to a line from stem to blossom...

Does genome organization matter in spermatozoa? A refined hypothesis to awaken the silent vessel.

PubMed

Ioannou, Dimitrios; Tempest, Helen G

2018-01-02

The spermatozoon is considered by many to be a silent vessel whose only function is to safely deliver the paternal genome to the maternal oocyte. As a result, the paternal contribution to fertilization and embryogenesis is frequently overlooked. However, the spermatozoon is a highly elaborate and specialized cell that is formed through the process of spermatogenesis. Spermatogenesis is a complex cellular program of differentiation that produces mature spermatozoa, which are essential for reproduction, fertilization, and normal embryonic development. The sperm cell is unique in morphology, chromatin structure, and function. Increasing evidence demonstrates that perturbations in chromatin integrity and organization could have a significant clinical impact on fertilization and embryogenesis. In this article we will review the evidence that demonstrates the paternal genome to be highly packaged and uniquely organized. We will postulate how the integrity and organization of the paternal genome likely has functional consequences that are critical for the establishment and maintenance of a viable pregnancy. In doing so, we hope to dispel the common myth that the sperm cell is a silent vessel; instead we will demonstrate the sperm cell to be a highly segmentally organized, epigenetically primed cell. 2D: two-dimension; 3C: chromosome conformation capture; 3D: three-dimension; 4D: four-dimension; CTs: chromosome territories; FISH: fluorescence in situ hybridization; IMSI: intra cytoplasmic morphologically selected sperm injection; ICSI: intracytoplasmic sperm injection; IVF: in-vitro fertilization; mESCs: mouse embryonic stem cells; NORs: nuclear organizing regions; TADs: topologically associated domain.

What characterizes the work culture at a hospital unit that successfully implements change - a correlation study.

PubMed

André, Beate; Sjøvold, Endre

2017-07-14

To successfully achieve change in healthcare, a balance between technology and "people ware", the human recourses, is necessary. However, the human aspect of the change implementation process has received less attention than the technological issues. The aim was to explore the factors that characterize the work culture in a hospital unit that successfully implemented change compared with the factors that characterize the work culture of a hospital unit with unsuccessful implementation. The Systematizing Person-Group Relations method was used for gathering and analyzing data to explore what dominate the behavior in a particular work environment identifying challenges, limitations and opportunities. This method applied six different dimensions, each representing different behavior in a work culture: Synergy, Withdrawal, Opposition, Dependence, Control and Nurture. We compared two different units at the same hospital, one that successfully implemented change and one that was unsuccessful. There were significant statistical differences between healthcare personnel working at a unit that successfully implemented change contrasted with the unit with unsuccessful implementation. These significant differences were found in both the synergy and control dimensions, which are important positive qualities in a work culture. The results of this study show that healthcare personnel at a unit with a successful implementation of change have a working environment with many positive qualities. This indicates that a work environment with a high focus on goal achievement and task orientation can handle the challenges of implementing changes.

Patient Safety Culture in Intensive Care Units from the Perspective of Nurses: A Cross-Sectional Study.

PubMed

Farzi, Sedigheh; Moladoost, Azam; Bahrami, Masoud; Farzi, Saba; Etminani, Reza

2017-01-01

One of the goals of nursing is providing safe care, prevention of injury, and health promotion of patients. Patient safety in intensive care units is threatened for various reasons. This study aimed to survey patient safety culture from the perspective of nurses in intensive care units. This cross-sectional study was conducted in 2016. Sampling was done using the convenience method. The sample consisted of 367 nurses working in intensive care units of teaching hospitals affiliated to Isfahan University of Medical Sciences. Data collection was performed using a two-part questionnaire that included demographic and hospital survey on Patient Safety Culture (HSOPSC) questionnaire. Data analysis was done using descriptive statistics (mean and standard deviation). Among the 12 dimensions of safety culture, the nurses assigned the highest score to "team work within units" (97.3%) and "Organizational learning-continuous improvement" (84%). They assigned the least score to "handoffs and transitions"(21.1%), "non-punitive response to errors" (24.7%), "Staffing" (35.6%), "Communication openness" (47.5%), and "Teamwork across units" (49.4%). The patient safety culture dimensions have low levels that require adequate attention and essential measures of health care centers including facilitating teamwork, providing adequate staff, and developing a checklist of handoffs and transitions. Furthermore, to increase reporting error and to promote a patient safety culture in intensive care units, some strategies should be adopted including a system-based approach to deal with the error.

Phytoremediation of explosives in groundwater using innovative wetlands-based treatment technologies

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

Sikora, F.J.; Behrends, L.L.; Coonrod, H.S.

1997-12-31

Many army ammunition plants across the country have problems with groundwater contaminated with explosives. A field demonstration was initiated at the Milan Army Ammunition Plant near Milan, Tennessee early in 1996 to demonstrate the feasibility of treating contaminated groundwater with constructed wetlands. Two different systems were designed and installed. A lagoon system consisted of two cells in series with each cell having dimensions of 24 x 9.4 x 0.6 m (L x W x H). A gravel-bed system consisted of three gravel-beds operated in series with a primary anaerobic cell having dimensions of 32 x 11 x 1.4 m (Lmore » x W x H), followed by a pair of secondary cells each with dimensions of 5.5 x 11 x 1.4 m (L x W x H). The primary cell is maintained anaerobic by adding powdered milk to the water every two weeks. The secondary cells are maintained aerobic via reciprocation, whereby water is pumped back and forth from one cell to another to cause a recurrent fill and drain action. The lagoons were planted with sago pond weed, water stargrass, elodea, and parrot feather. The gravel-bed wetlands were planted with canary grass, wool grass, sweet flag, and parrot feather. Water began flowing to each of the wetland treatment systems at 19 L min{sup {minus}1} starting in June 1996. The design hydraulic retention time through each treatment system was approximately 10 days. Influent and effluent water samples were collected every 2 weeks. Intensive sampling of water interior to the wetlands occurred every 2 months.« less

Green Tool

EPA Pesticide Factsheets

The Green Tool represents infiltration-based stormwater control practices. It allows modelers to select a BMP type, channel shape and BMP unit dimensions, outflow control devices, and infiltration method. The program generates an HSPF-formatted FTABLE.

7 CFR 51.783 - Diameter.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Florida Grapefruit Definitions § 51.783 Diameter. Diameter means the greatest dimension measured at right angles to a line from stem to blossom end. ...

7 CFR 51.783 - Diameter.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Florida Grapefruit Definitions § 51.783 Diameter. Diameter means the greatest dimension measured at right angles to a line from stem to blossom end. ...

7 CFR 51.1836 - Diameter.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Florida Tangerines Definitions § 51.1836 Diameter. Diameter means the greatest dimension measured at right angles to a line from stem to blossom end. ...

7 CFR 51.1836 - Diameter.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Florida Tangerines Definitions § 51.1836 Diameter. Diameter means the greatest dimension measured at right angles to a line from stem to blossom end. ...

Theoretical Dimensions of Small Unit Resilience

DTIC Science & Technology

2010-12-01

ending process and everyday and every experience offers a new education. Keep learning and keep moving forward. To my brother and sister Soldiers...strategies and coping mechanisms. 13 Unit Leadership and Coping Willingness to Seek Care Reducing Barriers to Care Family and Marital Support...identifies the following 10 combat skills: Buddies (Cohesion) Accountability Targeted Aggression 14 15 Tactical Awareness Lethally Armed Emotional

Educating for Peace and Justice: Religious Dimensions, K-6. 8th Edition.

ERIC Educational Resources Information Center

McGinnis, James

This revised teacher's manual focuses on the need to develop compassionate concern in students if they are to be moved to action. The 12-step processes in the 8 units promote a personal relationship or friendship with the persons or groups involved. The units include: (1) "Of Dreams and Vision"; (2) "Interpersonal Peacemaking/Reconciliation"; (3)…

Significant Learning Experiences for English Foreign Language Students (Experiencias significativas para estudiantes de inglés como lengua extranjera)

ERIC Educational Resources Information Center

Becerra, Luz María; McNulty, Maria

2010-01-01

This action research examines experiences that students in a grade 10 EFL class had with redesigning a grammar-unit into a topic-based unit. Strategies were formulating significant learning goals and objectives, and implementing and reflecting on activities with three dimensions of Dee Fink's (2003) taxonomy of significant learning: the human…

Climate-induced changes in vulnerability to biological threats in the southern United States

Treesearch

Rabiu Olatinwo; Qinfeng Guo; Songlin Fei; William Otrosina; Kier Klepzig; Douglas Streett

2014-01-01

Forest land managers face the challenges of preparing their forests for the impacts of climate change. However, climate change adds a new dimension to the task of developing and testing science-based management options to deal with the effects of stressors on forest ecosystems in the southern United States. The large spatial scale and complex interactions make...

Profile 2003: softwood sawmills in the United States and Canada

Treesearch

Henry Spelter; Matthew Alderman

2003-01-01

About 160 fewer softwood sawmills are operating in the United States and Canada than were 8 years ago. Nevertheless, the combined capacity of the remaining mills has increased by 16%, to over 173 million cubic meters. Of the approximately 1,140 mills, about 470 characterize their output as dimension lumber, accounting for 67% of capacity; 136 list studs as their...

The Rise of the "Blended Professional" in Higher Education: A Comparison between the United Kingdom, Australia and the United States

ERIC Educational Resources Information Center

Whitchurch, Celia

2009-01-01

This paper builds on earlier work by the author to explore the international dimensions of a study of the changing roles and identities of professional staff in higher education (Whitchurch 2008a, b). It further develops the concept of the "blended professional," characterising individuals with identities drawn from both professional and…

Origin of the OFF state variability in ReRAM cells

NASA Astrophysics Data System (ADS)

Salaoru, Iulia; Khiat, Ali; Li, Qingjiang; Berdan, Radu; Papavassiliou, Christos; Prodromakis, Themistoklis

2014-04-01

This work exploits the switching dynamics of nanoscale resistive random access memory (ReRAM) cells with particular emphasis on the origin of the observed variability when cells are consecutively cycled/programmed at distinct memory states. It is demonstrated that this variance is a common feature of all ReRAM elements and is ascribed to the formation and rupture of conductive filaments that expand across the active core, independently of the material employed as the active switching core, the causal physical switching mechanism, the switching mode (bipolar/unipolar) or even the unit cells' dimensions. Our hypothesis is supported through both experimental and theoretical studies on TiO2 and In2O3 : SnO2 (ITO) based ReRAM cells programmed at three distinct resistive states. Our prototypes employed TiO2 or ITO active cores over 5 × 5 µm2 and 100 × 100 µm2 cell areas, with all tested devices demonstrating both unipolar and bipolar switching modalities. In the case of TiO2-based cells, the underlying switching mechanism is based on the non-uniform displacement of ionic species that foster the formation of conductive filaments. On the other hand, the resistive switching observed in the ITO-based devices is considered to be due to a phase change mechanism. The selected experimental parameters allowed us to demonstrate that the observed programming variance is a common feature of all ReRAM devices, proving that its origin is dependent upon randomly oriented local disorders within the active core that have a substantial impact on the overall state variance, particularly for high-resistive states.

Carbon nanopipettes for cell probes and intracellular injection

NASA Astrophysics Data System (ADS)

Schrlau, Michael G.; Falls, Erica M.; Ziober, Barry L.; Bau, Haim H.

2008-01-01

We developed integrated, carbon-based pipettes with nanoscale dimensions (CNP) that can probe cells with minimal intrusion, inject fluids into the cells, and concurrently carry out electrical measurements. Our manufacturing technique does not require cumbersome nanoassembly and is amenable to mass production. Using CNPs, we demonstrate the injection of reagents into cells with minimal intrusion and without inhibiting cell growth.

Carbon nanopipettes for cell probes and intracellular injection.

PubMed

Schrlau, Michael G; Falls, Erica M; Ziober, Barry L; Bau, Haim H

2008-01-09

We developed integrated, carbon-based pipettes with nanoscale dimensions (CNP) that can probe cells with minimal intrusion, inject fluids into the cells, and concurrently carry out electrical measurements. Our manufacturing technique does not require cumbersome nanoassembly and is amenable to mass production. Using CNPs, we demonstrate the injection of reagents into cells with minimal intrusion and without inhibiting cell growth.

Electrolysis cell stimulation

NASA Technical Reports Server (NTRS)

Gordon, L. H.; Phillips, B. R.; Evangelista, J.

1978-01-01

Computer program represents attempt to understand and model characteristics of electrolysis cells. It allows user to determine how cell efficiency is affected by temperature, pressure, current density, electrolyte concentration, characteristic dimensions, membrane resistance, and electrolyte circulation rate. It also calculates ratio of bubble velocity to electrolyte velocity for anode and cathode chambers.

Modelling cell motility and chemotaxis with evolving surface finite elements

PubMed Central

Elliott, Charles M.; Stinner, Björn; Venkataraman, Chandrasekhar

2012-01-01

We present a mathematical and a computational framework for the modelling of cell motility. The cell membrane is represented by an evolving surface, with the movement of the cell determined by the interaction of various forces that act normal to the surface. We consider external forces such as those that may arise owing to inhomogeneities in the medium and a pressure that constrains the enclosed volume, as well as internal forces that arise from the reaction of the cells' surface to stretching and bending. We also consider a protrusive force associated with a reaction–diffusion system (RDS) posed on the cell membrane, with cell polarization modelled by this surface RDS. The computational method is based on an evolving surface finite-element method. The general method can account for the large deformations that arise in cell motility and allows the simulation of cell migration in three dimensions. We illustrate applications of the proposed modelling framework and numerical method by reporting on numerical simulations of a model for eukaryotic chemotaxis and a model for the persistent movement of keratocytes in two and three space dimensions. Movies of the simulated cells can be obtained from http://homepages.warwick.ac.uk/∼maskae/CV_Warwick/Chemotaxis.html. PMID:22675164

Development and validation of an observation tool for the assessment of nursing pain management practices in intensive care unit in a standardized clinical simulation setting.

PubMed

Gosselin, Emilie; Bourgault, Patricia; Lavoie, Stephan; Coleman, Robin-Marie; Méziat-Burdin, Anne

2014-12-01

Pain management in the intensive care unit is often inadequate. There is no tool available to assess nursing pain management practices. The aim of this study was to develop and validate a measuring tool to assess nursing pain management in the intensive care unit during standardized clinical simulation. A literature review was performed to identify relevant components demonstrating optimal pain management in adult intensive care units and to integrate them in an observation tool. This tool was submitted to an expert panel and pretested. It was then used to assess pain management practice during 26 discrete standardized clinical simulation sessions with intensive care nurses. The Nursing Observation Tool for Pain Management (NOTPaM) contains 28 statements grouped into 8 categories, which are grouped into 4 dimensions: subjective assessment, objective assessment, interventions, and reassessment. The tool's internal consistency was calculated at a Cronbach's alpha of 0.436 for the whole tool; the alpha varies from 0.328 to 0.518 for each dimension. To evaluate the inter-rater reliability, intra-class correlation coefficient was used, which was calculated at 0.751 (p < .001) for the whole tool, with variations from 0.619 to 0.920 (p < .01) between dimensions. The expert panel was satisfied with the content and face validity of the tool. The psychometric qualities of the NOTPaM developed in this study are satisfactory. However, the tool could be improved with slight modifications. Nevertheless, it was useful in assessing intensive care nurses' pain management in a standardized clinical simulation. The NOTPaM is the first tool created for this purpose. Copyright © 2014 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

A four-dimensional virtual hand brain-machine interface using active dimension selection.

PubMed

Rouse, Adam G

2016-06-01

Brain-machine interfaces (BMI) traditionally rely on a fixed, linear transformation from neural signals to an output state-space. In this study, the assumption that a BMI must control a fixed, orthogonal basis set was challenged and a novel active dimension selection (ADS) decoder was explored. ADS utilizes a two stage decoder by using neural signals to both (i) select an active dimension being controlled and (ii) control the velocity along the selected dimension. ADS decoding was tested in a monkey using 16 single units from premotor and primary motor cortex to successfully control a virtual hand avatar to move to eight different postures. Following training with the ADS decoder to control 2, 3, and then 4 dimensions, each emulating a grasp shape of the hand, performance reached 93% correct with a bit rate of 2.4 bits s(-1) for eight targets. Selection of eight targets using ADS control was more efficient, as measured by bit rate, than either full four-dimensional control or computer assisted one-dimensional control. ADS decoding allows a user to quickly and efficiently select different hand postures. This novel decoding scheme represents a potential method to reduce the complexity of high-dimension BMI control of the hand.

7 CFR 51.1016 - Diameter.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Persian (Tahiti) Limes Definitions § 51.1016 Diameter. Diameter means the greatest dimension measured at right angles to a line from stem to blossom end of the...

7 CFR 51.2656 - Diameter.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Grades for Sweet Cherries 1 Definitions § 51.2656 Diameter. Diameter means the greatest dimension measured at right angles to a line from the stem to the...

7 CFR 51.2656 - Diameter.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Grades for Sweet Cherries 1 Definitions § 51.2656 Diameter. Diameter means the greatest dimension measured at right angles to a line from the stem to the...

7 CFR 51.1016 - Diameter.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Persian (Tahiti) Limes Definitions § 51.1016 Diameter. Diameter means the greatest dimension measured at right angles to a line from stem to blossom end of the...

Development and design of experiments optimization of a high temperature proton exchange membrane fuel cell auxiliary power unit with onboard fuel processor

NASA Astrophysics Data System (ADS)

Karstedt, Jörg; Ogrzewalla, Jürgen; Severin, Christopher; Pischinger, Stefan

In this work, the concept development, system layout, component simulation and the overall DOE system optimization of a HT-PEM fuel cell APU with a net electric power output of 4.5 kW and an onboard methane fuel processor are presented. A highly integrated system layout has been developed that enables fast startup within 7.5 min, a closed system water balance and high fuel processor efficiencies of up to 85% due to the recuperation of the anode offgas burner heat. The integration of the system battery into the load management enhances the transient electric performance and the maximum electric power output of the APU system. Simulation models of the carbon monoxide influence on HT-PEM cell voltage, the concentration and temperature profiles within the autothermal reformer (ATR) and the CO conversion rates within the watergas shift stages (WGSs) have been developed. They enable the optimization of the CO concentration in the anode gas of the fuel cell in order to achieve maximum system efficiencies and an optimized dimensioning of the ATR and WGS reactors. Furthermore a DOE optimization of the global system parameters cathode stoichiometry, anode stoichiometry, air/fuel ratio and steam/carbon ratio of the fuel processing system has been performed in order to achieve maximum system efficiencies for all system operating points under given boundary conditions.

Association between body mass index and health-related quality of life, and the impact of self-reported long-term conditions - cross-sectional study from the south Yorkshire cohort dataset.

PubMed

Kearns, Benjamin; Ara, Roberta; Young, Tracey; Relton, Clare

2013-10-25

We sought to quantify the relationship between body mass index (BMI) and health-related quality (HRQoL) of life, as measured by the EQ-5D, whilst controlling for potential confounders. In addition, we hypothesised that certain long-term conditions (LTCs), for which being overweight or obese is a known risk factor, may mediate the association between BMI and HRQoL. Hence the aim of our study was to explore the association between BMI and HRQoL, first controlling for confounders and then exploring the potential impact of LTCs. We used baseline data from the South Yorkshire Cohort, a cross-sectional observational study which uses a cohort multiple randomised controlled trial design. For each EQ-5D health dimension we used logistic regression to model the probability of responding as having a problem for each of the five health dimensions. All continuous variables were modelled using fractional polynomials. We examined the impact on the coefficients for BMI of removing LTCs from our model. We considered the self-reported LTCs: diabetes, heart disease, stroke, cancer, osteoarthritis, breathing problems and high blood pressure. The dataset used in our analysis had data for 19,460 individuals, who had a mean EQ-5D score of 0.81 and a mean BMI of 26.3 kg/m². For each dimension, BMI and all of the LTCs were significant predictors. For overweight or obese individuals (BMI ≥ 25 kg/m²), each unit increase in BMI was associated with approximately a 3% increase in the odds of reporting a problem for the anxiety/depression dimension, a 8% increase for the mobility dimension, and approximately 6% for the remaining dimension s. Diabetes, heart disease, osteoarthritis and high blood pressure were identified as being potentially mediating variables for all of the dimensions. Compared to those of a normal weight (18.5 < BMI < 25 kg/m²), overweight and obese individuals had a reduced HRQoL, with each unit increase in BMI associated with approximately a 6% increase in the odds of reporting a problem on any of the EQ-5D health dimensions. There was evidence to suggest that diabetes, heart disease, osteoarthritis and high blood pressure may mediate the association between being overweight and HRQoL.

3D correlative light and electron microscopy of cultured cells using serial blockface scanning electron microscopy

PubMed Central

Lerner, Thomas R.; Burden, Jemima J.; Nkwe, David O.; Pelchen-Matthews, Annegret; Domart, Marie-Charlotte; Durgan, Joanne; Weston, Anne; Jones, Martin L.; Peddie, Christopher J.; Carzaniga, Raffaella; Florey, Oliver; Marsh, Mark; Gutierrez, Maximiliano G.

2017-01-01

ABSTRACT The processes of life take place in multiple dimensions, but imaging these processes in even three dimensions is challenging. Here, we describe a workflow for 3D correlative light and electron microscopy (CLEM) of cell monolayers using fluorescence microscopy to identify and follow biological events, combined with serial blockface scanning electron microscopy to analyse the underlying ultrastructure. The workflow encompasses all steps from cell culture to sample processing, imaging strategy, and 3D image processing and analysis. We demonstrate successful application of the workflow to three studies, each aiming to better understand complex and dynamic biological processes, including bacterial and viral infections of cultured cells and formation of entotic cell-in-cell structures commonly observed in tumours. Our workflow revealed new insight into the replicative niche of Mycobacterium tuberculosis in primary human lymphatic endothelial cells, HIV-1 in human monocyte-derived macrophages, and the composition of the entotic vacuole. The broad application of this 3D CLEM technique will make it a useful addition to the correlative imaging toolbox for biomedical research. PMID:27445312

7 CFR 51.344 - Size.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Apples for Processing Size § 51.344 Size. (a... buyer and seller. (c) Size is the dimension of the apples determined by the smallest opening through...

7 CFR 51.344 - Size.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Apples for Processing Size § 51.344 Size. (a... buyer and seller. (c) Size is the dimension of the apples determined by the smallest opening through...

7 CFR 51.1359 - Diameter.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Pears for Canning Definitions § 51.1359 Diameter. Diameter means the greatest dimension of the pear taken at right angles to a line running from the stem to...

7 CFR 51.1359 - Diameter.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., CERTIFICATION, AND STANDARDS) United States Standards for Pears for Canning Definitions § 51.1359 Diameter. Diameter means the greatest dimension of the pear taken at right angles to a line running from the stem to...

[Integration of a psychologist into Nephrology-Dialysis-Hypertension Operative Unit: from needs evaluation to the definition of an intervention model].

PubMed

Monica, Ratti Maria; Delli Zotti, Giulia Bruna; Spotti, Donatella; Sarno, Lucio

2014-01-01

Chronic Kidney Disease (CKD) and the dialytic treatment cause a significant psychological impact on patients, their families and on the medical-nursing staff too. The psychological aspects linked to the chronic condition of Kidney Disease generate the need to integrated a psychologist into the healthcare team of the Nephrology, Dialysis and Hypertension Operative Unit, in order to offer a specific and professional support to the patient during the different stages of the disease, to their caregivers and to the medical team. The aim of this collaboration project between Nephrology and Psychology is to create a global and integrated healthcare model. It does not give attention simply to the physical dimension of patients affected by CKD, but also to the emotional-affective, cognitive and social dimensions and to the health environment.

Enhanced precision of ankle torque measure with an open-unit dynamometer mounted with a 3D force-torque sensor.

PubMed

Toumi, A; Leteneur, S; Gillet, C; Debril, J-F; Decoufour, N; Barbier, F; Jakobi, J M; Simoneau-Buessinger, Emilie

2015-11-01

Many studies have focused on maximum torque exerted by ankle joint muscles during plantar flexion. While strength parameters are typically measured with isokinetic or isolated ankle dynamometers, these devices often present substantial limitations for the measurement of torque because they account for force in only 1 dimension (1D), and the device often constrains the body in a position that augments torque through counter movements. The purposes of this study were to determine the contribution of body position to ankle plantar-flexion torque and to assess the use of 1D and 3D torque sensors. A custom designed 'Booted, Open-Unit, Three dimension, Transportable, Ergometer' (B.O.T.T.E.) was used to quantify plantar flexion in two conditions: (1) when the participant was restrained within the unit (locked-unit) and (2) when the participant's position was independent of the ankle dynamometer (open-unit). Ten young males performed maximal voluntary isometric plantar-flexion contractions using the B.O.T.T.E. in open and locked-unit mechanical configurations. The B.O.T.T.E. was reliable with ICC higher than 0.90, and CV lower than 7 %. The plantar-flexion maximal resultant torque was significantly higher in the locked-unit compared with open-unit configuration (P < 0.001; +61 to +157 %) due to the addition of forces from the body being constrained within the testing device. A 1D compared with 3D torque sensor significantly underestimated the proper capacity of plantar-flexion torque production (P < 0.001; -37 to -60 %). Assessment of plantar-flexion torque should be performed with an open-unit dynamometer mounted with a 3D sensor that is exclusive of accessory muscles but inclusive of all ankle joint movements.

Optimal degrees of synaptic connectivity

PubMed Central

Litwin-Kumar, Ashok; Harris, Kameron Decker; Axel, Richard; Sompolinsky, Haim; Abbott, L. F.

2017-01-01

Summary Synaptic connectivity varies widely across neuronal types. Cerebellar granule cells receive five orders of magnitude fewer inputs than the Purkinje cells they innervate, and cerebellum-like circuits including the insect mushroom body also exhibit large divergences in connectivity. In contrast, the number of inputs per neuron in cerebral cortex is more uniform and large. We investigate how the dimension of a representation formed by a population of neurons depends on how many inputs they each receive and what this implies for learning associations. Our theory predicts that the dimensions of the cerebellar granule-cell and Drosophila Kenyon-cell representations are maximized at degrees of synaptic connectivity that match those observed anatomically, showing that sparse connectivity is sometimes superior to dense connectivity. When input synapses are subject to supervised plasticity, however, dense wiring becomes advantageous, suggesting that the type of plasticity exhibited by a set of synapses is a major determinant of connection density. PMID:28215558

Effects of distribution density and cell dimension of 3D vegetation model on canopy NDVI simulation base on DART

NASA Astrophysics Data System (ADS)

Tao, Zhu; Shi, Runhe; Zeng, Yuyan; Gao, Wei

2017-09-01

The 3D model is an important part of simulated remote sensing for earth observation. Regarding the small-scale spatial extent of DART software, both the details of the model itself and the number of models of the distribution have an important impact on the scene canopy Normalized Difference Vegetation Index (NDVI).Taking the phragmitesaustralis in the Yangtze Estuary as an example, this paper studied the effect of the P.australias model on the canopy NDVI, based on the previous studies of the model precision, mainly from the cell dimension of the DART software and the density distribution of the P.australias model in the scene, As well as the choice of the density of the P.australiass model under the cost of computer running time in the actual simulation. The DART Cell dimensions and the density of the scene model were set by using the optimal precision model from the existing research results. The simulation results of NDVI with different model densities under different cell dimensions were analyzed by error analysis. By studying the relationship between relative error, absolute error and time costs, we have mastered the density selection method of P.australias model in the simulation of small-scale spatial scale scene. Experiments showed that the number of P.australias in the simulated scene need not be the same as those in the real environment due to the difference between the 3D model and the real scenarios. The best simulation results could be obtained by keeping the density ratio of about 40 trees per square meter, simultaneously, of the visual effects.

The impact of servant leadership dimensions on leader-member exchange among health care professionals.

PubMed

Hanse, Jan Johansson; Harlin, Ulrika; Jarebrant, Caroline; Ulin, Kerstin; Winkel, Jörgen

2016-03-01

The aim of the current study was to investigate the impact of servant leadership dimensions on leader-member exchange (LMX) among health-care professionals. Leadership support and the quality of the dyadic relationship between the leader and the employee are essential regarding the work environment and turnover intentions in health care. A questionnaire-based cross-sectional study was undertaken at four hospital units in Sweden. The study sample included 240 employees. Significant bivariate correlations were found between all servant leadership dimensions and LMX. The strongest correlations were found between 'humility' and LMX (r = 0.69, P < 0.001), and 'empowerment' and LMX (r = 0.67, P < 0.001). The hierarchical regression analyses indicated that 'empowerment', 'humility' and 'stewardship' explained about 55% of the variance in LMX. In our study servant leadership dimensions were strongly related to LMX. The results identify specific servant leadership dimensions that are likely to be useful for developing a stronger exchange relationship between the leader (e.g. nursing manager) and individual subordinates in health care. © 2015 John Wiley & Sons Ltd.

Consumer Finance: Factors Affecting the Financial Literacy of Individuals with Limited English Proficiency. Report to Congressional Committees. GAO-10-518

ERIC Educational Resources Information Center

Cackley, Alicia Puente

2010-01-01

According to Census data, more than 12 million adults in the United States report they do not speak English well or at all. Proficiency in reading, writing, speaking, and understanding the English language appears to be linked to multiple dimensions of adult life in the United States, including financial literacy--the ability to make informed…

The Relationship between Quality of Work Life and Job Satisfaction: A Study of the Nation's Municipal Clerks.

ERIC Educational Resources Information Center

Bruce, Willa

This study empirically examined the quality of work life and job satisfaction of municipal clerks employed in cities in the United States. Questionnaires were sent to a random sample of 10 percent of the membership in the United States of the International Institute of Municipal Clerks. Results of factor analysis produced 12 distinct dimensions of…

An Evaluation and Ranking of Children's Hospital Websites in the United States.

PubMed

Huerta, Timothy R; Walker, Daniel M; Ford, Eric W

2016-08-22

Children's hospitals are faced with the rising need for technological innovation. Their prospective health care consumers, who increasingly depend on the Web and social media for communication and consumer engagement, drive this need. As patients and family members navigate the Web presence of hospitals, it is important for these specialized organizations to present themselves and their services efficiently. The purpose of this study was to evaluate the website content of children's hospitals in order to identify opportunities to improve website design and create benchmarks to judge improvement. All websites associated with a children's hospital were identified using a census list of all children's hospitals in the United States. In March of 2014, each website and its social media were evaluated using a Web crawler that provided a 5-dimensional assessment that included website accessibility, marketing, content, technology, and usability. The 5-dimensional assessment was scored on a scale ranging from 0 to 10 with positive findings rated higher on the scale. Websites were ranked by individual dimensions as well as according to their average ranking across all dimensions. Mean scores of 153 websites ranged from 5.05 to 8.23 across all 5 dimensions. Results revealed that no website scored a perfect 10 on any dimension and that room exists for meaningful improvement. Study findings allow for the establishment of baseline benchmarks for tracking future website and social media improvements and display the need for enhanced Web-based consumer engagement for children's hospitals.

Challenging patient safety culture: survey results.

PubMed

Hellings, Johan; Schrooten, Ward; Klazinga, Niek; Vleugels, Arthur

2007-01-01

The purpose of this paper is to measure patient safety culture in five Belgian general hospitals. Safety culture plays an important role in the approach towards greater patient safety in hospitals. The Patient Safety Culture Hospital questionnaire was distributed hospital-wide in five general hospitals. It evaluates ten patient safety culture dimensions and two outcomes. The scores were expressed as the percentage of positive answers towards patient safety for each dimension. The survey was conducted from March through November 2005. In total, 3,940 individuals responded (overall response rate = 77 per cent), including 2,813 nurses and assistants, 462 physicians, 397 physiotherapists, laboratory and radiology assistants, social workers and 64 pharmacists and pharmacy assistants. The dimensional positive scores were found to be low to average in all the hospitals. The lowest scores were "hospital management support for patient safety" (35 per cent), "non-punitive response to error" (36 per cent), "hospital transfers and transitions" (36 per cent), "staffing" (38 per cent), and "teamwork across hospital units" (40 per cent). The dimension "teamwork within hospital units" generated the highest score (70 per cent). Although the same dimensions were considered problematic in the different hospitals, important variations between the five hospitals were observed. A comprehensive and tailor-made plan to improve patient safety culture in these hospitals can now be developed. Results indicate that important aspects of the patient safety culture in these hospitals need improvement. This is an important challenge to all stakeholders wishing to improve patient safety.

Sense of place and place identity: review of neuroscientific evidence.

PubMed

Lengen, Charis; Kistemann, Thomas

2012-09-01

The aim of this review is to bring the phenomenological sense of place approach together with current results from neuroscience. We searched in neuroscientific literature for ten dimensions which were beforehand identified to be important in a phenomenological sense of place/place identity model: behaviour, body, emotion, attention, perception, memory, orientation, spirituality, meaning/value and culture/sociality. Neuroscience has identified many neurobiological correlates of phenomenological observations concerning sense of place. The human brain comprises specific and specialised structures and processes to perceive, memorise, link, assess and use spatial information. Specific parts (hippocampus, entorhinal, parahippocampal and parietal cortex), subregions (parahippocampal place area, lingual landmark area), and cells (place cells, grid cells, border cells, head direction cells) have been identified, their specific function could be understood and their interaction traced. Neuroscience has provided evidence that place constitutes a distinct dimension in neuronal processing. This reinforces the phenomenological argumentation of human geography and environmental psychology. Copyright © 2012 Elsevier Ltd. All rights reserved.

Two-dimensional computer simulation of EMVJ and grating solar cells under AMO illumination

NASA Technical Reports Server (NTRS)

Gray, J. L.; Schwartz, R. J.

1984-01-01

A computer program, SCAP2D (Solar Cell Analysis Program in 2-Dimensions), is used to evaluate the Etched Multiple Vertical Junction (EMVJ) and grating solar cells. The aim is to demonstrate how SCAP2D can be used to evaluate cell designs. The cell designs studied are by no means optimal designs. The SCAP2D program solves the three coupled, nonlinear partial differential equations, Poisson's Equation and the hole and electron continuity equations, simultaneously in two-dimensions using finite differences to discretize the equations and Newton's Method to linearize them. The variables solved for are the electrostatic potential and the hole and electron concentrations. Each linear system of equations is solved directly by Gaussian Elimination. Convergence of the Newton Iteration is assumed when the largest correction to the electrostatic potential or hole or electron quasi-potential is less than some predetermined error. A typical problem involves 2000 nodes with a Jacobi matrix of order 6000 and a bandwidth of 243.

Lateral dimension-dependent antibacterial activity of graphene oxide sheets.

PubMed

Liu, Shaobin; Hu, Ming; Zeng, Tingying Helen; Wu, Ran; Jiang, Rongrong; Wei, Jun; Wang, Liang; Kong, Jing; Chen, Yuan

2012-08-21

Graphene oxide (GO) is a promising precursor to produce graphene-family nanomaterials for various applications. Their potential health and environmental impacts need a good understanding of their cellular interactions. Many factors may influence their biological interactions with cells, and the lateral dimension of GO sheets is one of the most relevant material properties. In this study, a model bacterium, Escherichia coli ( E. coli ), was used to evaluate the antibacterial activity of well-dispersed GO sheets, whose lateral size differs by more than 100 times. Our results show that the antibacterial activity of GO sheets toward E. coli cells is lateral size dependent. Larger GO sheets show stronger antibacterial activity than do smaller ones, and they have different time- and concentration-dependent antibacterial activities. Large GO sheets lead to most cell loss after 1 h incubation, and their concentration strongly influences antibacterial activity at relative low concentration (<10 μg/mL). In contrast, when incubating with small GO sheets up to 4 h, the inactivation rate of E. coli cells continues increasing. The increase of small GO sheet concentration also results in persistent increases in their antibacterial activity. In this study, GO sheets with different lateral sizes are all well dispersed, and their oxidation capacity toward glutathione is similar, consistent with X-ray photoelectron spectroscopy and ultraviolet-visible absorption spectroscopy results. This suggests the lateral size-dependent antibacterial activity of GO sheets is caused by neither their aggregation states, nor oxidation capacity. Atomic force microscope analysis of GO sheets and cells shows that GO sheets interact strongly with cells. Large GO sheets more easily cover cells, and cells cannot proliferate once fully covered, resulting in the cell viability loss observed in the followed colony counting test. In contrast, small GO sheets adhere to the bacterial surfaces, which cannot effectively isolate cells from environment. This study highlights the importance of tailoring the lateral dimension of GO sheets to optimize the application potential with minimal risks for environmental health and safety.

Anti-cancer evaluation of quercetin embedded PLA nanoparticles synthesized by emulsified nanoprecipitation.

PubMed

Pandey, Sanjeev K; Patel, Dinesh K; Thakur, Ravi; Mishra, Durga P; Maiti, Pralay; Haldar, Chandana

2015-04-01

This study was carried out to synthesize quercetin (Qt) embedded poly(lactic acid) (PLA) nanoparticles (PLA-Qt) and to evaluate anti-cancer efficacy of PLA-Qt by using human breast cancer cells. PLA-Qt were synthesized by using novel emulsified nanoprecipitation technique with varying dimension of 32 ± 8 to 152 ± 9 nm of PLA-Qt with 62 ± 3% (w/w) entrapment efficiency by varying the concentration of polymer, emulsifier, drug and preparation temperature. The dimension of PLA-Qt was measured through transmission electron microscopy indicating larger particle size at higher concentration of PLA. The release rate of Qt from PLA-Qt was found to be more sustained for larger particle dimension (152 ± 9 nm) as compared to smaller particle dimension (32 ± 8 nm). Interaction between Qt and PLA was verified through spectroscopic and calorimetric methods. Delayed diffusion and stronger interaction in PLA-Qt caused the sustained delivery of Qt from the polymer matrix. In vitro cytotoxicity study indicate the killing of ∼ 50% breast cancer cells in two days at 100 μg/ml of drug concentration while the ∼ 40% destruction of cells require 5 days for PLA-Qt (46 ± 6 nm; 20mg/ml of PLA). Thus our results propose anticancer efficacy of PLA-Qt nanoparticles in terms of its sustained release kinetics revealing novel vehicle for the treatment of cancer. Copyright © 2015 Elsevier B.V. All rights reserved.

An 11-Year Climatology of Storms in Which Most Cloud-to-Ground Flashes Lower Positive Charge

NASA Astrophysics Data System (ADS)

MacGorman, D. R.; Eddy, A.; Williams, E. R.; Calhoun, K. M.

2017-12-01

Previous studies have shown that storms which produce frequent cloud-to-ground (CG) lightning dominated by flashes lowering positive charge to ground (+CG flashes) tend to have a so called "inverted" vertical distribution of charge. Such storms have implications for our understanding of electrification processes. We have analyzed eleven years of National Lightning Detection Network data to count +CG and -CG flashes having peak currents ≥15 kA in grid cells with dimensions of 15 km x 15 km x 15 min, with overlapping grid boxes every 5 km along both x and y over the contiguous United States and grids every 5 min in time. These dimensions were chosen because 15 km corresponds roughly to the horizontal size of typical storm cells and 15 min is roughly half the typical duration of a cell. To focus on storms dominated by +CG flashes, we identified all grid cells satisfying one of four sets of thresholds: cells in which +CG flashes for 15 min constitute ≥80%, 90%, or 100% of ≥10 CG flashes or 100% of ≥20 CG flashes. These percentages are larger than those used in most previous studies of +CG flashes. Our primary goal is to investigate the environmental and storm characteristics conducive to +CG flashes and "inverted-polarity" charge distributions, but here we concentrate on the interannual and seasonal distributions of storms satisfying the above thresholds and examine also their relationship to severe weather. As in previous climatological studies of geographic variations in the +CG fraction of total CG flashes, most storms satisfying our thresholds were in a swath stretching from far eastern Colorado and western Kansas roughly northward through Nebraska, the Dakotas, and Minnesota. This region overlaps much of the region in which radar inferred that hail larger than 2.9 cm in diameter most often occurs, but is shifted westward and northward from maxima of observer reports of large-hail occurrence. Although the relationship with radar-inferred large-hail frequency suggests a common dependence on some storm characteristics, storms satisfying our thresholds for +CG flashes also occurred, although less frequently, in regions in which few storms were inferred to have produced large hail, such as east of mountain ranges in northwestern states, so relationships with severe weather will need to be examined on a storm-by-storm basis.

Visual motion integration by neurons in the middle temporal area of a New World monkey, the marmoset

PubMed Central

Solomon, Selina S; Tailby, Chris; Gharaei, Saba; Camp, Aaron J; Bourne, James A; Solomon, Samuel G

2011-01-01

Abstract The middle temporal area (MT/V5) is an anatomically distinct region of primate visual cortex that is specialized for the processing of image motion. It is generally thought that some neurons in area MT are capable of signalling the motion of complex patterns, but this has only been established in the macaque monkey. We made extracellular recordings from single units in area MT of anaesthetized marmosets, a New World monkey. We show through quantitative analyses that some neurons (35 of 185; 19%) are capable of signalling pattern motion (‘pattern cells’). Across several dimensions, the visual response of pattern cells in marmosets is indistinguishable from that of pattern cells in macaques. Other neurons respond to the motion of oriented contours in a pattern (‘component cells’) or show intermediate properties. In addition, we encountered a subset of neurons (22 of 185; 12%) insensitive to sinusoidal gratings but very responsive to plaids and other two-dimensional patterns and otherwise indistinguishable from pattern cells. We compared the response of each cell class to drifting gratings and dot fields. In pattern cells, directional selectivity was similar for gratings and dot fields; in component cells, directional selectivity was weaker for dot fields than gratings. Pattern cells were more likely to have stronger suppressive surrounds, prefer lower spatial frequencies and prefer higher speeds than component cells. We conclude that pattern motion sensitivity is a feature of some neurons in area MT of both New and Old World monkeys, suggesting that this functional property is an important stage in motion analysis and is likely to be conserved in humans. PMID:21946851

Determination of morphological parameters of biological cells by analysis of scattered-light distributions

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

Burger, D.E.

1979-11-01

The extraction of morphological parameters from biological cells by analysis of light-scatter patterns is described. A light-scattering measurement system has been designed and constructed that allows one to visually examine and photographically record biological cells or cell models and measure the light-scatter pattern of an individual cell or cell model. Using a laser or conventional illumination, the imaging system consists of a modified microscope with a 35 mm camera attached to record the cell image or light-scatter pattern. Models of biological cells were fabricated. The dynamic range and angular distributions of light scattered from these models was compared to calculatedmore » distributions. Spectrum analysis techniques applied on the light-scatter data give the sought after morphological cell parameters. These results compared favorably to shape parameters of the fabricated cell models confirming the mathematical model procedure. For nucleated biological material, correct nuclear and cell eccentricity as well as the nuclear and cytoplasmic diameters were determined. A method for comparing the flow equivalent of nuclear and cytoplasmic size to the actual dimensions is shown. This light-scattering experiment provides baseline information for automated cytology. In its present application, it involves correlating average size as measured in flow cytology to the actual dimensions determined from this technique. (ERB)« less

English Validation of the Parental Socialization Scale—ESPA29

PubMed Central

Martínez, Isabel; Cruise, Edie; García, Óscar F.; Murgui, Sergio

2017-01-01

Parenting styles have traditionally been studied following the classical two-dimensional orthogonal model of parental socialization. The Parental Socialization Scale ESPA29 is used to measure the four styles of parental socialization through the acceptance/involvement and strictness/imposition dimensions. The ESPA29 scale is a developmentally appropriate measure of parenting styles, which has been validated in several languages including Spanish, Italian, and Brazilian Portuguese. In this study, the English translation of the ESPA29 was evaluated. The objective of the work is to test the ESPA29’s structure of parenting practices with a United States sample measuring parenting practices using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). The scores of fathers’ and mothers’ behavioral practices toward their children were obtained for a sample of 911 United States adolescents between 14 and 18 years of age. First, the total sample was split and a principal components analysis with varimax rotation was carried out with one of the two halves. EFA showed a two-factor structure fully congruent with the theoretical model for mothers’ and fathers’ scores. Next, a CFA was calculated on the second half by using the factor structure obtained in the previous EFA. The CFA replicated the two-factor structure with appropriate fit index. The seven parenting practices that were measured loaded appropriately on the acceptance/involvement and strictness/imposition dimensions. Then, the multigroup analysis between girls and boys showed equal loading in the factors and equal covariation between the acceptance/involvement and the strictness/imposition dimensions. Additionally, the two dimensions of the ESPA29 scale were related to self-esteem in order to obtain an external validity index. The findings confirm the invariant structure of the ESPA29 was in the United States and their equivalence in both fathers’ and mothers’ scores. These findings validate the instrument and confirm its applicability in cross-cultural research on parenting practices and child adjustment. PMID:28611711

English Validation of the Parental Socialization Scale-ESPA29.

PubMed

Martínez, Isabel; Cruise, Edie; García, Óscar F; Murgui, Sergio

2017-01-01

Parenting styles have traditionally been studied following the classical two-dimensional orthogonal model of parental socialization. The Parental Socialization Scale ESPA29 is used to measure the four styles of parental socialization through the acceptance/involvement and strictness/imposition dimensions. The ESPA29 scale is a developmentally appropriate measure of parenting styles, which has been validated in several languages including Spanish, Italian, and Brazilian Portuguese. In this study, the English translation of the ESPA29 was evaluated. The objective of the work is to test the ESPA29's structure of parenting practices with a United States sample measuring parenting practices using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). The scores of fathers' and mothers' behavioral practices toward their children were obtained for a sample of 911 United States adolescents between 14 and 18 years of age. First, the total sample was split and a principal components analysis with varimax rotation was carried out with one of the two halves. EFA showed a two-factor structure fully congruent with the theoretical model for mothers' and fathers' scores. Next, a CFA was calculated on the second half by using the factor structure obtained in the previous EFA. The CFA replicated the two-factor structure with appropriate fit index. The seven parenting practices that were measured loaded appropriately on the acceptance/involvement and strictness/imposition dimensions. Then, the multigroup analysis between girls and boys showed equal loading in the factors and equal covariation between the acceptance/involvement and the strictness/imposition dimensions. Additionally, the two dimensions of the ESPA29 scale were related to self-esteem in order to obtain an external validity index. The findings confirm the invariant structure of the ESPA29 was in the United States and their equivalence in both fathers' and mothers' scores. These findings validate the instrument and confirm its applicability in cross-cultural research on parenting practices and child adjustment.

Alternatives to Weight Tolerance Permits

DOT National Transportation Integrated Search

2000-10-01

A complex web of government regulations in the United States establishes maximum weights for vehicles on public roads. The primary purpose is to ensure compatibility of roadway design and operations with vehicle weight and dimensions. Of particular c...

Towards early detection of cervical cancer: Fractal dimension of AFM images of human cervical epithelial cells at different stages of progression to cancer.

PubMed

Guz, Nataliia V; Dokukin, Maxim E; Woodworth, Craig D; Cardin, Andrew; Sokolov, Igor

2015-10-01

We used AFM HarmoniX modality to analyse the surface of individual human cervical epithelial cells at three stages of progression to cancer, normal, immortal (pre-malignant) and carcinoma cells. Primary cells from 6 normal strains, 6 cancer, and 6 immortalized lines (derived by plasmid DNA-HPV-16 transfection of cells from 6 healthy individuals) were tested. This cell model allowed for good control of the cell phenotype down to the single cell level, which is impractical to attain in clinical screening tests (ex-vivo). AFM maps of physical (nonspecific) adhesion are collected on fixed dried cells. We show that a surface parameter called fractal dimension can be used to segregate normal from both immortal pre-malignant and malignant cells with sensitivity and specificity of more than 99%. The reported method of analysis can be directly applied to cells collected in liquid cytology screening tests and identified as abnormal with regular optical methods to increase sensitivity. Despite cervical smear screening, sometimes it is very difficult to differentiate cancers cells from pre-malignant cells. By using AFM to analyze the surface properties of human cervical epithelial cells, the authors were able to accurately identify normal from abnormal cells. This method could augment existing protocols to increase diagnostic accuracy. Copyright © 2015. Published by Elsevier Inc.

Apple cuticle: the perfect interface

NASA Astrophysics Data System (ADS)

Curry, Eric; Arey, Bruce

2010-06-01

The domestic apple might well be called an 'extreme' fruit. In the arid Northwest United States, the fruit often tolerates surface temperatures ranging from -2 °C in the early spring to 50 °C in the heat of summer, and again to -2 °C during controlled postharvest storage for up to 12 months. During its 18-month existence, the apple maintains a cuticle that is dynamic and environmentally responsive to protect against 1) cellular water loss during desiccation stress and 2) excessive uptake of standing surface moisture. Physiological disorders of the peel such as russeting, cracking, splitting, flecking and lenticel marking, develop as epidermal cells respond to rapid changes in ambient conditions at specific developmental stages during the growing season. Resultant market losses underlie research investigating the nature of apple cuticle growth and development. Ultrastructural analysis of the pro-cuticle using scanning electron microscopy indicates an overlapping network of lipid-based distally-elongating microtubules--produced by and connected to epidermal cells--which co-polymerize to form an organic solvent-insoluble semi-permeable cutin matrix. Microtubule elongation, aggregation, and polymerization function together as long as the fruit continues to enlarge. The nature of lipid transport from the epidermal cells through the cell wall to become part of the cuticular matrix was explored using an FEI Helios NanoLabTM DualBeamTM focused ion beam/scanning electron microscope on chemically- and cryo-fixed peel tissue from mature or freshly harvested apples. Based on microtubule dimensions, regular projections found at the cell/cuticle interface suggest an array of microtubule-like structures associated with the epidermal cell.

Landsat 8 Data Modeled as DGGS Data Cubes

NASA Astrophysics Data System (ADS)

Sherlock, M. J.; Tripathi, G.; Samavati, F.

2016-12-01

In the context of tracking recent global changes in the Earth's landscape, Landsat 8 provides high-resolution multi-wavelength data with a temporal resolution of sixteen days. Such a live dataset can benefit novel applications in environmental monitoring. However, a temporal analysis of this dataset in its native format is a challenging task mostly due to the huge volume of geospatial images and imperfect overlay of different day Landsat 8 images. We propose the creation of data cubes derived from Landsat 8 data, through the use of a Discrete Global Grid System (DGGS). DGGS referencing of Landsat 8 data provides a cell-based representation of the pixel values for a fixed area on earth, indexed by keys. Having the calibrated cell-based Landsat 8 images can speed up temporal analysis and facilitate parallel processing using distributed systems. In our method, the Landsat 8 dataset hosted on Amazon Web Services (AWS) is downloaded using a web crawler and stored on a filesystem. We apply the cell-based DGGS referencing (using Pyxis SDK) to Landsat 8 images which provide a rhombus based tessellation of equal area cells for our use-case. After this step, the cell-images which overlay perfectly on different days, are stacked in the temporal dimension and stored into data cube units. The depth of the cube represents the number of temporal images of the same cell and can be updated when new images are received each day. Harnessing the regular spatio-temporal structure of data cubes, we want to compress, query, transmit and visualize big Landsat 8 data in an efficient way for temporal analysis.

Safety culture in the maternity unit of hospitals in Ilam province, Iran: a census survey using HSOPSC tool.

PubMed

Akbari, Nahid; Malek, Marzieh; Ebrahimi, Parvin; Haghani, Hamid; Aazami, Sanaz

2017-01-01

Improving quality of maternal care as well as patients' safety are two important issues in health-care service. Therefore, this study aimed to assess the culture of patient safety at maternity units. This cross-sectional study was conducted among staffs working at maternity units in seven hospitals of Ilam city, Iran. The staffs included in this study were gynecologists and midwifes working in different positions including matron, supervisors, head of departments and staffs. Data were collected using the Hospital Survey on Patient Safety Culture (HSOPSC). This study indicated that 59.1% of participants reported fair level of overall perceptions of safety and 67.1% declared that no event was reported during the past 12 months. The most positively perceived dimension of safety culture was teamwork within departments in view of managers (79.41) and personnel (81.10). However, the least positively perceived dimensions of safety culture was staffing levels. The current study revealed areas of strength (teamwork within departments) and weakness (staffing, punitive responses to error) among managers and personnel. In addition, we found that staffs in Ilam's hospitals accept the patient safety culture in maternity units, but, still are far away from excellent culture of patient safety. Therefore, it is necessary to promote culture of patient's safety among professions working in the maternity units of Ilam's hospitals.

Structural and optical properties of furfurylidenemalononitrile thin films

NASA Astrophysics Data System (ADS)

Ali, H. A. M.

2013-03-01

Thin films of furfurylidenemalononitrile (FMN) were deposited on different substrates at room temperature by thermal evaporation technique under a high vacuum. The structure of the powder was confirmed by Fourier transformation infrared (FTIR) technique. The unit cell dimensions were determined from X-ray diffraction (XRD) studies. The optical properties were investigated using spectrophotometric measurements of the transmittance and reflectance at normal incidence of light in the wavelength range from 200 to 2500 nm. The refractive index (n), the absorption index (k) and the absorption coefficient (α) were calculated. The analysis of the spectral behavior of the absorption coefficient in the absorption region revealed an indirect allowed transition. The refractive index dispersion was analyzed using the single oscillator model. Some dispersion parameters were estimated. Complex dielectric function and optical conductivity were determined. The influence of the irradiation with high-energy X-rays (6 MeV) on the studied properties was also investigated.

Magnetic properties of M0.3Fe2.7O4 (M = Fe, Zn and Mn) ferrites nanoparticles

NASA Astrophysics Data System (ADS)

Modaresi, Nahid; Afzalzadeh, Reza; Aslibeiki, Bagher; Kameli, Parviz

2018-06-01

In the present article a comparative study on the structural and magnetic properties of nano-sized M0.3Fe0.7Fe2O4 (M = Fe, Zn and Mn) ferrites have been reported. The X-ray diffraction (XRD) patterns show that the crystallite size depends on the cation distribution. The Rietveld refinement of XRD patterns using MAUD software determines the distribution of cations and unit cell dimensions. The magnetic measurements show that the maximum and minimum value of saturation magnetization is obtained for Zn and Mn doped samples, respectively. The peak temperature of AC magnetic susceptibility of Zn and Fe doped samples below 300 K shows the superparamagnetic behavior in these samples at room temperature. the AC susceptibility results confirm the presence of strong interactions between the nanoparticles which leads to a superspin glass state in the samples at low temperatures.

Crystallization of the Na+-translocating NADH:quinone oxidoreductase from Vibrio cholerae

PubMed Central

Casutt, Marco S.; Wendelspiess, Severin; Steuber, Julia; Fritz, Günter

2010-01-01

The Na+-translocating NADH:quinone oxidoreductase (Na+-NQR) from the human pathogen Vibrio cholerae couples the exergonic oxidation of NADH by membrane-bound quinone to Na+ translocation across the membrane. Na+-NQR consists of six different subunits (NqrA–NqrF) and contains a [2Fe–2S] cluster, a noncovalently bound FAD, a noncovalently bound riboflavin, two covalently bound FMNs and potentially Q8 as cofactors. Initial crystallization of the entire Na+-NQR complex was achieved by the sitting-drop method using a nanolitre dispenser. Optimization of the crystallization conditions yielded flat yellow-coloured crystals with dimensions of up to 200 × 80 × 20 µm. The crystals diffracted to 4.0 Å resolution and belonged to space group P21, with unit-cell parameters a = 94, b = 146, c = 105 Å, α = γ = 90, β = 111°. PMID:21139223

Micromagnetic simulation of energy consumption and excited eigenmodes in elliptical nanomagnetic switches

NASA Astrophysics Data System (ADS)

Carlotti, G.; Madami, M.; Gubbiotti, G.; Tacchi, S.

2014-02-01

Sub-200 nm patterned magnetic dots are key elements for the design of magnetic switches, memory cells or elementary units of nanomagnetic logic circuits. In this paper, we analyse by micromagnetic simulations the magnetization reversal, the dissipated energy and the excited spin eigenmodes in bistable magnetic switches, consisting of elliptical nanodots with 100×60 nm lateral dimensions. Two different strategies for reversal are considered and the relative results compared: (i) the irreversible switching obtained by the application of an external field along the easy axis, in the direction opposite to the initial magnetization; (ii) the precessional switching accomplished by the application of a short magnetic field pulse, oriented perpendicular to the initial magnetization direction. The obtained results are discussed in terms of deviation from the macrospin behavior, energy dissipation and characteristics of the spectrum of spin eigenmodes excited during the magnetization reversal process.

Pulsed electron nuclear double resonance studies of the photoexcited triplet state of pentacene in p-terphenyl crystals at room temperature.

PubMed

Yago, Tomoaki; Link, Gerhard; Kothe, Gerd; Lin, Tien-Sung

2007-09-21

Pulsed electron nuclear double resonance (ENDOR) using a modified Davies-type [Phys. Lett. 47A, 1 (1974)] sequence is employed to study the hyperfine (HF) structure of the photoexcited triplet state of pentacene dispersed in protonated and deuterated p-terphenyl single crystals. The strong electron spin polarization and long phase memory time of triplet pentacene enable us to perform the ENDOR measurements on the S=1 spin system at room temperature. Proton HF tensor elements and spin density values of triplet pentacene are extracted from a detailed angular-dependent study in which the orientation of the magnetic field is varied systematically in two different pentacene planes. Analysis reveals that the pentacene molecule is no longer planar in the p-terphenyl host lattice. The distortion is more pronounced in the deuterated crystal where the unit cell dimensions are slightly smaller than those of the protonated crystal.

A Double-Negative Metamaterial-Inspired Mobile Wireless Antenna for Electromagnetic Absorption Reduction.

PubMed

Alam, Touhidul; Faruque, Mohammad Rashed Iqbal; Islam, Mohammad Tariqul

2015-07-29

A double-negative metamaterial-inspired antenna is presented for mobile wireless applications. The antenna consists of a semi-circular radiating patch and a 3 × 4 hexagonal shaped metamaterial unit cell array in the ground plane. The antenna is fed with a 50 Ω microstrip feed line. The electric dimensions of the proposed antenna are 0.20λ × 0.26λ × 0.004λ, at the low-end frequency. The proposed antenna achieves a -10 dB impedance with a bandwidth of 2.29 GHz at the lower band and 1.28 GHz at the upper band and can operate for most of the mobile applications such as upper GSM bands, WiMAX, Bluetooth, and wireless local area network (WLAN) frequency bands. The focused novelties of the proposed antenna are its small size, multi-standard operating bands, and electromagnetic absorption reduction at all the operating frequencies using the double-negative metamaterial ground plane.

Membrane-constrained acoustic metamaterials for low frequency sound insulation

NASA Astrophysics Data System (ADS)

Wang, Xiaole; Zhao, Hui; Luo, Xudong; Huang, Zhenyu

2016-01-01

We present a constrained membrane-type acoustic metamaterial (CMAM) that employs constraint sticks to add out-of-plane dimensions in the design space of MAM. A CMAM sample, which adopts constraint sticks to suppress vibrations at the membrane center, was fabricated to achieve a sound transmission loss (STL) peak of 26 dB at 140 Hz, with the static areal density of 6.0 kg/m2. The working mechanism of the CMAM as an acoustic metamaterial is elucidated by calculating the averaged normal displacement, the equivalent areal density, and the effective dynamic mass of a unit cell through finite element simulations. Furthermore, the vibration modes of the CMAM indicate that the eigenmodes related to STL dips are shifted into high frequencies, thus broadening its effective bandwidth significantly. Three samples possessing the same geometry and material but different constraint areas were fabricated to illustrate the tunability of STL peaks at low frequencies.

Isolation and characterization of a bacteriophage for Vibrio fetus.

PubMed

Bryner, J H; Ritchie, A E; Foley, J W; Berman, D T

1970-07-01

Bacteriophages were isolated from 22 of 38 strains of Vibrio fetus by an enrichment process, utilizing the donor and host strains growing together in fluid thioglycollate medium. One phage, V-45, isolated by the conventional lawn-spot method, was characterized by stability in broth, growth kinetics, and morphology. It was sensitive to rapid thermal inactivation, chloroform, and pH values above 6.5. Calcium was required for phage replication and stability in broth. Magnesium provided the best protection against thermal inactivation at 50 C in the pH range of 6.5 to 7.5. The minimum latent period was 135 min, rise time was 75 min, and average burst size was 35 plaque-forming units per infected cell. Phage V-45 resembled Bradley's morphological group B, having a long tail without contractile sheath. Dimensions were: head, about 50 nm; tail, about 7 by 240 nm; and tail lumen, 2 to 3 nm.

Metrication study for large space telescope

NASA Technical Reports Server (NTRS)

Creswick, F. A.; Weller, A. E.

1973-01-01

Various approaches which could be taken in developing a metric-system design for the Large Space Telescope, considering potential penalties on development cost and time, commonality with other satellite programs, and contribution to national goals for conversion to the metric system of units were investigated. Information on the problems, potential approaches, and impacts of metrication was collected from published reports on previous aerospace-industry metrication-impact studies and through numerous telephone interviews. The recommended approach to LST metrication formulated in this study cells for new components and subsystems to be designed in metric-module dimensions, but U.S. customary practice is allowed where U.S. metric standards and metric components are not available or would be unsuitable. Electrical/electronic-system design, which is presently largely metric, is considered exempt from futher metrication. An important guideline is that metric design and fabrication should in no way compromise the effectiveness of the LST equipment.

Lightweight Solar Paddle with High Specific Power of 150 W/Kg

NASA Astrophysics Data System (ADS)

Shimazaki, Kazunori; Takahashi, Masato; Imaizumi, Mitsuru; Takamoto, Tatsuya; Ito, Takehiko; Nozaki, Yukishige; Kusawake, Hiroaki

2014-08-01

A lightweight solar paddle using space solar sheet (SSS) is currently being developed, which uses glass-type SSS (G-SSS) comprising InGaP/GaAs/InGaAs triple- junction high-efficiency thin-film solar cells. To avoid damage to the G-SSS due to vibration during launch, we adopted a new architecture on a panel. This panel employed a curved frame-type structure, on which the G-SSS is mounted and test models were manufactured to evaluate the vibration tolerance. The dimensions of the 1.0-cm-thick unit panel were about 1.0 × 1.0 m. Acoustic and sine vibration tests were performed on the model and the results demonstrated the high durability of the curved panel in an acoustic and vibration environments. The specific power of the solar paddle using the curved panel is estimated at approximately 150 W/kg at an array power of about 10 kW.

Modified Sierpenski Antenna With Metamaterial For Wireless Applications

NASA Astrophysics Data System (ADS)

Aggarwal, Ishita; Pandey, Sujata

2017-08-01

This paper presents a multiband antenna based on modified sierpenski fractal structure along with metamaterials for wireless applications. Multi bands are obtained at 2.1 GHz, 5.73 GHz, 7.6 GHz and 8.4 GHz with return losses -21.49 dB,-36.36 dB,-45dB, and -23.46 dBrespectively. The dimension of the substrate used for this antenna is 52 x 60 x 1.6 mm3 and dielectric constant is 4.4 with tanδ of 0.002. The peak gain of 6.6 dB, return loss of -45 dB and VSWR of 1 are obtained at 7.6 GHz. Metamaterial unit cells are loaded on ground to improve the antenna parameters. This is a simple and compact design and has multiband features suitable for WIMAX, WLAN, C-band and X-band applications. This design is simulated by using HFSS 14.

Dimensions of care for dementia sufferers in long-term care institutions: are they related to outcomes?

PubMed

Chappell, N L; Reid, R C

2000-07-01

This study empirically examined whether dimensions of care cluster in special care units (SCUs) compared with non-SCUs. The relationship between SCU status plus separate measures of the dimensions of care and outcomes for dementia sufferers was then investigated. Data were drawn from the Intermediate Care Facility Project. The sample (N = 510) included residents with dementia, aged 65 and older, in intermediate care facilities throughout the province of British Columbia. Canada. Longitudinal data included 6 outcomes: cognitive function, behavioral problems of agitation and social skills, physical functioning, and quality of life measured through affect and expressive language skills. Separate multiple linear regression equations were estimated, relating each of these outcomes to 5 dimensions of care: preadmission and admission procedures. staff training and education, nonuse of physical and chemical restraints, flexible care routines and resident-relevant activities, and the environment. The results showed there is virtually no clustering of dimensions along SCU/non-SCU lines. Neither SCU status nor the individual dimensions were highly predictive of outcomes. Residents' affect at t1 emerged as a characteristic that was significantly correlated with other outcomes. This Canadian research can be added to the few but growing number of rigorous studies that suggest SCUs are not homogeneous and do not necessarily provide better care than non-SCUs. Moreover, it raises questions about the benefits of "best practice" dimensions of care, regardless of SCU status.

Mechanoreceptor afferent activity compared with receptor field dimensions and pressure changes in feline urinary bladder.

PubMed

Downie, J W; Armour, J A

1992-11-01

The relationship between vesical mechanoreceptor field dimensions and afferent nerve activity recorded in pelvic plexus nerve filaments was examined in chloralose-anesthetized cats. Orthogonal receptor field dimensions were monitored with piezoelectric ultrasonic crystals. Reflexly generated bladder contractile activity made measurements difficult, therefore data were collected from cats subjected to actual sacral rhizotomy. Afferent activity was episodic and was initiated at different pressure and receptor field dimension thresholds. Maximum afferent activity did not correlate with maximum volume or pressure. Furthermore, activity was not linearly related to intravesical pressure, receptor field dimensions, or calculated wall tension. Pressure-length hysteresis of the receptor fields occurred. The responses of identified afferent units and their associated receptor field dimensions to brief contractions elicited by the ganglion stimulant 1,1-dimethyl-4-phenylpiperazinium iodide (2.5-20 micrograms i.a.), studied under constant volume or constant pressure conditions, are compatible with bladder mechanoreceptors behaving as tension receptors. Because activity generated by bladder mechanoreceptors did not correlate in a simple fashion with intravesical pressure or receptor field dimensions, it is concluded that such receptors are influenced by the viscoelastic properties of the bladder wall. Furthermore, as a result of the heterogeneity of the bladder wall, receptor field tension appears to offer a more precise relationship with the activity of bladder wall mechanoreceptors than does intravesical pressure.

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

Kim, G. H.; Pesaran, A.; Spotnitz, R.

To understand further the thermal abuse behavior of large format Li-ion batteries for automotive applications, the one-dimensional modeling approach formulated by Hatchard et al. was reproduced. Then it was extended to three dimensions so we could consider the geometrical features, which are critical in large cells for automotive applications. The three-dimensional model captures the shapes and dimensions of cell components and the spatial distributions of materials and temperatures, and is used to simulate oven tests, and to determine how a local hot spot can propagate through the cell. In simulations of oven abuse testing of cells with cobalt oxide cathodemore » and graphite anode with standard LiPF6 electrolyte, the three-dimensional model predicts that thermal runaway will occur sooner or later than the lumped model, depending on the size of the cell. The model results showed that smaller cells reject heat faster than larger cells; this may prevent them from going into thermal runaway under identical abuse conditions. In simulations of local hot spots inside a large cylindrical cell, the three-dimensional model predicts that the reactions initially propagate in the azimuthal and longitudinal directions to form a hollow cylinder-shaped reaction zone.« less

Characterization of hydrogel printer for direct cell-laden scaffolds

NASA Astrophysics Data System (ADS)

Whulanza, Yudan; Arsyan, Rendria; Saragih, Agung Shamsuddin

2018-02-01

The additive manufacturing technology has been massively developed since the last decade. The technology was previously known as rapid prototyping techniques that aimed to produce a prototyping product in fast and economical way. Currently, this technique is also applied to fabricate microstructure utilized in tissue engineering technology. Here, we introduce a 3D printer which using hydrogel gelatin to realize cell laden scaffold with dimension around 50-100 µm. However, in order to fabricate such a precise dimension, an optimum working parameters are required to control the physical properties of gelatin. At the end of our study, we formulated the best parameters to perform the product as we desired.

User handbook for block IV silicon solar cell modules

NASA Technical Reports Server (NTRS)

Smokler, M. I.

1982-01-01

The essential electrical and mechanical characteristics of block 4 photovoltaic solar cell modules are described. Such module characteristics as power output, nominal operating voltage, current-voltage characteristics, nominal operating cell temperature, and dimensions are tabulated. The limits of the environmental and other stress tests to which the modules are subjected are briefly described.

Wood

Treesearch

David W. Green; Robert H. White; Antoni TenWolde; William Simpson; Joseph Murphy; Robert J. Ross; Roland Hernandez; Stan T. Lebow

2006-01-01

Wood is a naturally formed organic material consisting essentially of elongated tubular elements called cells arranged in a parallel manner for the most part. These cells vary in dimensions and wall thickness with position in the tree, age, conditions of growth, and kind of tree. The walls of the cells are formed principally of chain molecules of cellulose, polymerized...

viSNE enables visualization of high dimensional single-cell data and reveals phenotypic heterogeneity of leukemia.

PubMed

Amir, El-ad David; Davis, Kara L; Tadmor, Michelle D; Simonds, Erin F; Levine, Jacob H; Bendall, Sean C; Shenfeld, Daniel K; Krishnaswamy, Smita; Nolan, Garry P; Pe'er, Dana

2013-06-01

New high-dimensional, single-cell technologies offer unprecedented resolution in the analysis of heterogeneous tissues. However, because these technologies can measure dozens of parameters simultaneously in individual cells, data interpretation can be challenging. Here we present viSNE, a tool that allows one to map high-dimensional cytometry data onto two dimensions, yet conserve the high-dimensional structure of the data. viSNE plots individual cells in a visual similar to a scatter plot, while using all pairwise distances in high dimension to determine each cell's location in the plot. We integrated mass cytometry with viSNE to map healthy and cancerous bone marrow samples. Healthy bone marrow automatically maps into a consistent shape, whereas leukemia samples map into malformed shapes that are distinct from healthy bone marrow and from each other. We also use viSNE and mass cytometry to compare leukemia diagnosis and relapse samples, and to identify a rare leukemia population reminiscent of minimal residual disease. viSNE can be applied to any multi-dimensional single-cell technology.

The Reconstruction Problem Revisited

NASA Technical Reports Server (NTRS)

Suresh, Ambaby

1999-01-01

The role of reconstruction in avoiding oscillations in upwind schemes is reexamined, with the aim of providing simple, concise proofs. In one dimension, it is shown that if the reconstruction is any arbitrary function bounded by neighboring cell averages and increasing within a cell for increasing data, the resulting scheme is monotonicity preserving, even though the reconstructed function may have overshoots and undershoots at the cell edges and is in general not a monotone function. In the special case of linear reconstruction, it is shown that merely bounding the reconstruction between neighboring cell averages is sufficient to obtain a monotonicity preservinc,y scheme. In two dimensions, it is shown that some ID TVD limiters applied in each direction result in schemes that are not positivity preserving, i.e. do not give positive updates when the data are positive. A simple proof is given to show that if the reconstruction inside the cell is bounded by the neighboring cell averages (including corner neighbors), then the scheme is positivity preserving. A new limiter that enforces this condition but is not as dissipative as the Minmod limiter is also presented.

Surface-modified CMOS IC electrochemical sensor array targeting single chromaffin cells for highly parallel amperometry measurements.

PubMed

Huang, Meng; Delacruz, Joannalyn B; Ruelas, John C; Rathore, Shailendra S; Lindau, Manfred

2018-01-01

Amperometry is a powerful method to record quantal release events from chromaffin cells and is widely used to assess how specific drugs modify quantal size, kinetics of release, and early fusion pore properties. Surface-modified CMOS-based electrochemical sensor arrays allow simultaneous recordings from multiple cells. A reliable, low-cost technique is presented here for efficient targeting of single cells specifically to the electrode sites. An SU-8 microwell structure is patterned on the chip surface to provide insulation for the circuitry as well as cell trapping at the electrode sites. A shifted electrode design is also incorporated to increase the flexibility of the dimension and shape of the microwells. The sensitivity of the electrodes is validated by a dopamine injection experiment. Microwells with dimensions slightly larger than the cells to be trapped ensure excellent single-cell targeting efficiency, increasing the reliability and efficiency for on-chip single-cell amperometry measurements. The surface-modified device was validated with parallel recordings of live chromaffin cells trapped in the microwells. Rapid amperometric spikes with no diffusional broadening were observed, indicating that the trapped and recorded cells were in very close contact with the electrodes. The live cell recording confirms in a single experiment that spike parameters vary significantly from cell to cell but the large number of cells recorded simultaneously provides the statistical significance.

A comparative analysis of the relationship between organizational climate and job satisfaction of medical technologists.

PubMed

McMahon, J T; Ivancevich, J M; Matteson, M T

1977-01-01

This study examines the quality of the total workplace enviroment (organizational climate) as a correlate of six dimensions of job satisfaction for a sample of 344 medical technologists. The main focus is upon comparisons of administrators versus nonadministrators, hospital laboratory personnel versus nonhospital laboratory personnel, and men versus women. Various dimensions or organizational climate were found to be important correlates of job satisfaction, and similarities and differences between the units of analysis are noted. Also discussed are the implications for the managers of medical technologists.

On the complexity of turbulence near a wall

NASA Technical Reports Server (NTRS)

Moin, Parviz

1992-01-01

Some measures of the intrinsic complexity of the near wall turbulence are reviewed. The number of modes required in an 'optimal' eigenfunction expansion is compared with the dimension obtained from the calculation of Liapunov exponents. These measures are of the same order, but they are very large. It is argued that the basic building block element of the near wall turbulence can be isolated in a small region of space (minimal flow unit). When the size of the domain is taken into account, the dimension becomes more manageable.

Fabrication of high gradient insulators by stack compression

DOEpatents

Harris, John Richardson; Sanders, Dave; Hawkins, Steven Anthony; Norona, Marcelo

2014-04-29

Individual layers of a high gradient insulator (HGI) are first pre-cut to their final dimensions. The pre-cut layers are then stacked to form an assembly that is subsequently pressed into an HGI unit with the desired dimension. The individual layers are stacked, and alignment is maintained, using a sacrificial alignment tube that is removed after the stack is hot pressed. The HGI's are used as high voltage vacuum insulators in energy storage and transmission structures or devices, e.g. in particle accelerators and pulsed power systems.

Optimization of Selected Remote Sensing Algorithms for Embedded NVIDIA Kepler GPU Architecture

NASA Technical Reports Server (NTRS)

Riha, Lubomir; Le Moigne, Jacqueline; El-Ghazawi, Tarek

2015-01-01

This paper evaluates the potential of embedded Graphic Processing Units in the Nvidias Tegra K1 for onboard processing. The performance is compared to a general purpose multi-core CPU and full fledge GPU accelerator. This study uses two algorithms: Wavelet Spectral Dimension Reduction of Hyperspectral Imagery and Automated Cloud-Cover Assessment (ACCA) Algorithm. Tegra K1 achieved 51 for ACCA algorithm and 20 for the dimension reduction algorithm, as compared to the performance of the high-end 8-core server Intel Xeon CPU with 13.5 times higher power consumption.

A four-dimensional virtual hand brain-machine interface using active dimension selection

NASA Astrophysics Data System (ADS)

Rouse, Adam G.

2016-06-01

Objective. Brain-machine interfaces (BMI) traditionally rely on a fixed, linear transformation from neural signals to an output state-space. In this study, the assumption that a BMI must control a fixed, orthogonal basis set was challenged and a novel active dimension selection (ADS) decoder was explored. Approach. ADS utilizes a two stage decoder by using neural signals to both (i) select an active dimension being controlled and (ii) control the velocity along the selected dimension. ADS decoding was tested in a monkey using 16 single units from premotor and primary motor cortex to successfully control a virtual hand avatar to move to eight different postures. Main results. Following training with the ADS decoder to control 2, 3, and then 4 dimensions, each emulating a grasp shape of the hand, performance reached 93% correct with a bit rate of 2.4 bits s-1 for eight targets. Selection of eight targets using ADS control was more efficient, as measured by bit rate, than either full four-dimensional control or computer assisted one-dimensional control. Significance. ADS decoding allows a user to quickly and efficiently select different hand postures. This novel decoding scheme represents a potential method to reduce the complexity of high-dimension BMI control of the hand.

A four-dimensional virtual hand brain-machine interface using active dimension selection

PubMed Central

Rouse, Adam G.

2018-01-01

Objective Brain-machine interfaces (BMI) traditionally rely on a fixed, linear transformation from neural signals to an output state-space. In this study, the assumption that a BMI must control a fixed, orthogonal basis set was challenged and a novel active dimension selection (ADS) decoder was explored. Approach ADS utilizes a two stage decoder by using neural signals to both i) select an active dimension being controlled and ii) control the velocity along the selected dimension. ADS decoding was tested in a monkey using 16 single units from premotor and primary motor cortex to successfully control a virtual hand avatar to move to eight different postures. Main Results Following training with the ADS decoder to control 2, 3, and then 4 dimensions, each emulating a grasp shape of the hand, performance reached 93% correct with a bit rate of 2.4 bits/s for eight targets. Selection of eight targets using ADS control was more efficient, as measured by bit rate, than either full four-dimensional control or computer assisted one-dimensional control. Significance ADS decoding allows a user to quickly and efficiently select different hand postures. This novel decoding scheme represents a potential method to reduce the complexity of high-dimension BMI control of the hand. PMID:27171896

Regulation of Cell Diameter, For3p Localization, and Cell Symmetry by Fission Yeast Rho-GAP Rga4p

PubMed Central

Das, Maitreyi; Wiley, David J.; Medina, Saskia; Vincent, Helen A.; Larrea, Michelle; Oriolo, Andrea

2007-01-01

Control of cellular dimensions and cell symmetry are critical for development and differentiation. Here we provide evidence that the putative Rho-GAP Rga4p of Schizosaccharomyces pombe controls cellular dimensions. rga4Δ cells are wider in diameter and shorter in length, whereas Rga4p overexpression leads to reduced diameter of the growing cell tip. Consistent with a negative role in cell growth control, Rga4p protein localizes to the cell sides in a “corset” pattern, and to the nongrowing cell tips. Additionally, rga4Δ cells show an altered growth pattern similar to that observed in mutants of the formin homology protein For3p. Consistent with these observations, Rga4p is required for normal localization of For3p and for normal distribution of the actin cytoskeleton. We show that different domains of the Rga4p protein mediate diverse morphological functions. The C-terminal GAP domain mediates For3p localization to the cell tips and maintains cell diameter. Conversely, overexpression of the N-terminal LIM homology domain of Rga4p promotes actin cable formation in a For3p-dependent manner. Our studies indicate that Rga4p functionally interacts with For3p and has a novel function in the control of cell diameter and cell growth. PMID:17377067

The Integration of International Agricultural Concepts into Agricultural Science Programs in the North Central Region of the United States. Summary of Research 78.

ERIC Educational Resources Information Center

Ibezim, Don O.; McCracken, J. David

A study examined the extent to which international agricultural dimensions were taught in secondary agricultural programs and factors associated with the extent of integration. A systematic sampling technique was used to select a random sample of 332 of the 2,612 secondary agricultural teachers in 12 states of the North Central United States. Of…

Body Dimensions and Proportions, White and Negro Children, 6-11 Years; United States. National Health Survey Series 11, No. 143

ERIC Educational Resources Information Center

Malina, Robert M.; And Others

The fifth in a series of reports presenting analyses and discussions of data on height, weight, and 28 other body measurements taken from a probability sample of noninstitutionalized children in the United States aged 6-11 years, this document compares the growth patterns of white and Negro children for 20 body measurements. Emphasis is placed on…

The PR2D (Place, Route in 2-Dimensions) automatic layout computer program handbook

NASA Technical Reports Server (NTRS)

Edge, T. M.

1978-01-01

Place, Route in 2-Dimensions is a standard cell automatic layout computer program for generating large scale integrated/metal oxide semiconductor arrays. The program was utilized successfully for a number of years in both government and private sectors but until now was undocumented. The compilation, loading, and execution of the program on a Sigma V CP-V operating system is described.

49 CFR 587.14 - Deformable face component dimensions and material specifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... tolerance of ±2.5 mm (0.1 in) unless otherwise specified. (a) Main honeycomb block. (1) Dimensions. The main honeycomb block has a height of 650 mm (25.6 in) (in the direction of honeycomb ribbon axis), a width of 1,000 mm (39.4 in), and a depth of 450 mm (17.7 in)(in the direction of honeycomb cell axis). (2...

49 CFR 587.14 - Deformable face component dimensions and material specifications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... tolerance of ±2.5 mm (0.1 in) unless otherwise specified. (a) Main honeycomb block. (1) Dimensions. The main honeycomb block has a height of 650 mm (25.6 in) (in the direction of honeycomb ribbon axis), a width of 1,000 mm (39.4 in), and a depth of 450 mm (17.7 in)(in the direction of honeycomb cell axis). (2...

49 CFR 587.14 - Deformable face component dimensions and material specifications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... tolerance of ±2.5 mm (0.1 in) unless otherwise specified. (a) Main honeycomb block. (1) Dimensions. The main honeycomb block has a height of 650 mm (25.6 in) (in the direction of honeycomb ribbon axis), a width of 1,000 mm (39.4 in), and a depth of 450 mm (17.7 in)(in the direction of honeycomb cell axis). (2...

49 CFR 587.14 - Deformable face component dimensions and material specifications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... tolerance of ±2.5 mm (0.1 in) unless otherwise specified. (a) Main honeycomb block. (1) Dimensions. The main honeycomb block has a height of 650 mm (25.6 in) (in the direction of honeycomb ribbon axis), a width of 1,000 mm (39.4 in), and a depth of 450 mm (17.7 in)(in the direction of honeycomb cell axis). (2...

49 CFR 587.14 - Deformable face component dimensions and material specifications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... tolerance of ±2.5 mm (0.1 in) unless otherwise specified. (a) Main honeycomb block. (1) Dimensions. The main honeycomb block has a height of 650 mm (25.6 in) (in the direction of honeycomb ribbon axis), a width of 1,000 mm (39.4 in), and a depth of 450 mm (17.7 in)(in the direction of honeycomb cell axis). (2...

Physical dimensions, torsional performance, bending properties, and metallurgical characteristics of rotary endodontic instruments. VI. Canal Master drills.

PubMed

Luebke, N H; Brantley, W A; Sabri, Z I; Luebke, F L; Lausten, L L

1995-05-01

A laboratory study was performed on machine-driven Canal Master drills to determine their physical dimensions, torsional performance, bending properties, and metallurgical characteristics in fracture. Physical dimensions were determined for each of the available sizes (#50 to #100) of Canal Master drills from the manufacturer that distributes these instruments in the United States. Samples were also tested in clockwise torsion using a Maillefer memocouple. Bending properties of cantilever specimens were measured with a Tinius Olsen stiffness tester. Bending fatigue testing was performed on a unique laboratory apparatus. Scanning electron microscope examination confirmed visual observations that the stainless steel Canal Master drills exhibited ductile torsional fracture. This study is part of a continuing investigation to establish standards for all machine-driven rotary endodontic instruments.

Mathematical structure of unit systems

NASA Astrophysics Data System (ADS)

Kitano, Masao

2013-05-01

We investigate the mathematical structure of unit systems and the relations between them. Looking over the entire set of unit systems, we can find a mathematical structure that is called preorder (or quasi-order). For some pair of unit systems, there exists a relation of preorder such that one unit system is transferable to the other unit system. The transfer (or conversion) is possible only when all of the quantities distinguishable in the latter system are always distinguishable in the former system. By utilizing this structure, we can systematically compare the representations in different unit systems. Especially, the equivalence class of unit systems (EUS) plays an important role because the representations of physical quantities and equations are of the same form in unit systems belonging to an EUS. The dimension of quantities is uniquely defined in each EUS. The EUS's form a partially ordered set. Using these mathematical structures, unit systems and EUS's are systematically classified and organized as a hierarchical tree.

Electrospun Polycaprolactone Scaffolds for Small-Diameter Tissue Engineered Blood Vessels

NASA Astrophysics Data System (ADS)

Lee, Carol Hsiu-Yueh

Cardiovascular disease is the leading cause of death in the United States with many patients requiring coronary artery bypass grafting. The current standard is using autografts such as the saphenous vein or intimal mammary artery, however creating a synthetic graft could eliminate this painful and inconvenient procedure. Large diameter grafts have long been established with materials such as DacronRTM and TeflonRTM, however these materials have not proved successful in small-diameter (< 6 mm) grafts where thrombosis and intimal hyperplasia are common in graft failure. With the use of a synthetic biodegradable polymer (polycaprolactone) we utilize our expertise in electrospinning and femtosecond laser ablation to create a novel tri-layered tissue engineered blood vessel containing microchannels. The benefits of creating a tri-layer is to mimic native arteries that contain an endothelium to prevent thrombosis in the inner layer, aligned smooth muscle cells in the middle to control vasodilation and constriction, and a mechanically robust outer layer. The following work evaluates the mechanical properties of such a graft (tensile, fatigue, burst pressure, and suture retention strength), the ability to rapidly align cells in laser ablated microchannels in PCL scaffolds, and the biological integration (co-culture of endothelial and smooth muscle cells) with electrospun PCL scaffolds. The conclusions from this work establish that the electrospun tri-layers provide adequate mechanical strength as a tissue engineered blood vessel, that laser ablated microchannels are able to contain the smooth muscle cells, and that cells are able to adhere to PCL fibers. However, future work includes adjusting microchannel dimensions to properly align smooth muscle cells along with perfect co-cultures of endothelial and smooth muscle cells on the electrospun tri-layer.

Biological length scale topography enhances cell-substratum adhesion of human corneal epithelial cells

PubMed Central

Karuri, Nancy W.; Liliensiek, Sara; Teixeira, Ana I.; Abrams, George; Campbell, Sean; Nealey, Paul F.; Murphy, Christopher J.

2006-01-01

Summary The basement membrane possesses a rich 3-dimensional nanoscale topography that provides a physical stimulus, which may modulate cell-substratum adhesion. We have investigated the strength of cell-substratum adhesion on nanoscale topographic features of a similar scale to that of the native basement membrane. SV40 human corneal epithelial cells were challenged by well-defined fluid shear, and cell detachment was monitored. We created silicon substrata with uniform grooves and ridges having pitch dimensions of 400-4000 nm using X-ray lithography. F-actin labeling of cells that had been incubated for 24 hours revealed that the percentage of aligned and elongated cells on the patterned surfaces was the same regardless of pitch dimension. In contrast, at the highest fluid shear, a biphasic trend in cell adhesion was observed with cells being most adherent to the smaller features. The 400 nm pitch had the highest percentage of adherent cells at the end of the adhesion assay. The effect of substratum topography was lost for the largest features evaluated, the 4000 nm pitch. Qualitative and quantitative analyses of the cells during and after flow indicated that the aligned and elongated cells on the 400 nm pitch were more tightly adhered compared to aligned cells on the larger patterns. Selected experiments with primary cultured human corneal epithelial cells produced similar results to the SV40 human corneal epithelial cells. These findings have relevance to interpretation of cell-biomaterial interactions in tissue engineering and prosthetic design. PMID:15226393

Device for monitoring cell voltage

DOEpatents

Doepke, Matthias [Garbsen, DE; Eisermann, Henning [Edermissen, DE

2012-08-21

A device for monitoring a rechargeable battery having a number of electrically connected cells includes at least one current interruption switch for interrupting current flowing through at least one associated cell and a plurality of monitoring units for detecting cell voltage. Each monitoring unit is associated with a single cell and includes a reference voltage unit for producing a defined reference threshold voltage and a voltage comparison unit for comparing the reference threshold voltage with a partial cell voltage of the associated cell. The reference voltage unit is electrically supplied from the cell voltage of the associated cell. The voltage comparison unit is coupled to the at least one current interruption switch for interrupting the current of at least the current flowing through the associated cell, with a defined minimum difference between the reference threshold voltage and the partial cell voltage.

A low-background piston-cylinder-type hybrid high pressure cell for muon-spin rotation/relaxation experiments

NASA Astrophysics Data System (ADS)

Shermadini, Z.; Khasanov, R.; Elender, M.; Simutis, G.; Guguchia, Z.; Kamenev, K. V.; Amato, A.

2017-10-01

A low background double-wall piston-cylinder-type pressure cell is developed at the Paul Scherrer Institute. The cell is made from BERYLCO-25 (beryllium copper) and MP35N nonmagnetic alloys with the design and dimensions which are specifically adapted to muon-spin rotation/relaxation (μSR) measurements. The mechanical design and performance of the pressure cell are evaluated using finite-element analysis (FEA). By including the measured stress-strain characteristics of the materials into the finite-element model, the cell dimensions are optimized with the aim to reach the highest possible pressure while maintaining the sample space large (6 mm in diameter and 12 mm high). The presented unconventional design of the double-wall piston-cylinder pressure cell with a harder outer MP35N sleeve and a softer inner CuBe cylinder enables pressures of up to 2.6 GPa to be reached at ambient temperature, corresponding to 2.2 GPa at low temperatures without any irreversible damage to the pressure cell. The nature of the muon stopping distribution, mainly in the sample and in the CuBe cylinder, results in a low-background μSR signal.

Dynamical Mechanism of Scaling Behaviors in Multifractal Structure

NASA Astrophysics Data System (ADS)

Kim, Kyungsik; Jung, Jae Won; Kim, Soo Yong

2010-03-01

The pattern of stone distribution in the game of Go (Baduk, Weiqi, or Igo) can be treated in the mathematical and physical languages of multifractals. The concepts of fractals and multifractals have relevance to many fields of science and even arts. A significant and fascinating feature of this approach is that it provides a proper interpretation for the pattern of the two-colored (black and white) stones in terms of the numerical values of the generalized dimension and the scaling exponent. For our case, these statistical quantities can be estimated numerically from the black, white, and mixed stones, assuming the excluded edge effect that the cell form of the Go game has the self-similar structure. The result from the multifractal structure allows us to find a definite and reliable fractal dimension, and it precisely verifies that the fractal dimension becomes larger, as the cell of grids increases. We also find the strength of multifractal structures from the difference in the scaling exponents in the black, white, and mixed stones.

The role of the sca-1+/CD31- cardiac progenitor cell population in postinfarction left ventricular remodeling.

PubMed

Wang, Xiaohong; Hu, Qingsong; Nakamura, Yasuhiro; Lee, Joseph; Zhang, Ge; From, Arthur H L; Zhang, Jianyi

2006-07-01

Cardiac stem cell-like populations exist in adult hearts, and their roles in cardiac repair remain to be defined. Sca-1 is an important surface marker for cardiac and other somatic stem cells. We hypothesized that heart-derived Sca-1(+)/CD31(-) cells may play a role in myocardial infarction-induced cardiac repair/remodeling. Mouse heart-derived Sca-1(+)/CD31(-) cells cultured in vitro could be induced to express both endothelial cell and cardiomyocyte markers. Immunofluorescence staining and fluorescence-activated cell sorting analysis indicated that endogenous Sca-1(+)/CD31(-) cells were significantly increased in the mouse heart 7 days after myocardial infarction (MI). Western blotting confirmed elevated Sca-1 protein expression in myocardium 7 days after MI. Transplantation of Sca-1(+)/CD31(-) cells into the acutely infarcted mouse heart attenuated the functional decline and adverse structural remodeling initiated by MI as evidenced by an increased left ventricular (LV) ejection fraction, a decreased LV end-diastolic dimension, a decreased LV end-systolic dimension, a significant increase of myocardial neovascularization, and modest cardiomyocyte regeneration. Attenuation of LV remodeling was accompanied by remarkably improved myocardial bioenergetic characteristics. The beneficial effects of cell transplantation appear to primarily depend on paracrine effects of the transplanted cells on new vessel formation and native cardiomyocyte function. Sca-1(+)/CD31(-) cells may hold therapeutic possibilities with regard to the treatment of ischemic heart disease.

Selective Individual Primary Cell Capture Using Locally Bio-Functionalized Micropores

PubMed Central

Liu, Jie; Bombera, Radoslaw; Leroy, Loïc; Roupioz, Yoann; Baganizi, Dieudonné R.; Marche, Patrice N.; Haguet, Vincent; Mailley, Pascal; Livache, Thierry

2013-01-01

Background Solid-state micropores have been widely employed for 6 decades to recognize and size flowing unlabeled cells. However, the resistive-pulse technique presents limitations when the cells to be differentiated have overlapping dimension ranges such as B and T lymphocytes. An alternative approach would be to specifically capture cells by solid-state micropores. Here, the inner wall of 15-µm pores made in 10 µm-thick silicon membranes was covered with antibodies specific to cell surface proteins of B or T lymphocytes. The selective trapping of individual unlabeled cells in a bio-functionalized micropore makes them recognizable just using optical microscopy. Methodology/Principal Findings We locally deposited oligodeoxynucleotide (ODN) and ODN-conjugated antibody probes on the inner wall of the micropores by forming thin films of polypyrrole-ODN copolymers using contactless electro-functionalization. The trapping capabilities of the bio-functionalized micropores were validated using optical microscopy and the resistive-pulse technique by selectively capturing polystyrene microbeads coated with complementary ODN. B or T lymphocytes from a mouse splenocyte suspension were specifically immobilized on micropore walls functionalized with complementary ODN-conjugated antibodies targeting cell surface proteins. Conclusions/Significance The results showed that locally bio-functionalized micropores can isolate target cells from a suspension during their translocation throughout the pore, including among cells of similar dimensions in complex mixtures. PMID:23469221

Structural and Process Factors That Influence Clinical Nurse Specialist Role Implementation.

PubMed

Kilpatrick, Kelley; Tchouaket, Eric; Carter, Nancy; Bryant-Lukosius, Denise; DiCenso, Alba

2016-01-01

The aim of this study was to examine the influence of structure and process on clinical nurse specialist (CNS) role implementation. We conducted a secondary analysis of cross-sectional survey data. The study was performed in Canada. The authors included 445 of 471 questionnaires (94.5%) of graduate-prepared CNSs. Based on Donabedian's framework, we conducted a secondary analysis of CNS responses using hierarchical regression. The internal consistency of the 6 CNS role dimensions and team dynamics subscales was excellent. The use of a framework to guide CNS role implementation influences all the role dimensions. Employer understanding of the CNS role, working in an urban catchment area, specialty certification, and more years in a CNS role had a direct positive influence on team dynamics. Full-time employment exerted a direct negative influence on this dimension. Furthermore, team dynamics (as a mediator variable), seeing patients in practice, and having an office in the clinical unit exerted a direct positive influence on the clinical dimension. Having an annual performance appraisal and a job description exerted a direct negative influence on the clinical dimension. Employer understanding, working in an urban area, full-time employment, and specialty certification had an indirect effect on the clinical dimension. Accountability to a nonnurse manager exerted a direct negative influence on the education dimension. The research and scholarly/professional development dimensions were influenced by more years in a CNS role. Accountability to a nurse manager exerted a direct positive influence on the organizational leadership dimension; unionization and seeing patients in practice had a direct negative influence on this dimension. Seeing patients in practice and full-time employment exerted a direct positive influence on the consultation dimension. The identification of structures and processes that influence CNS role implementation may inform strategies used by providers and decision makers to optimize these roles across healthcare settings and support the delivery of high-quality care.

In vitro synthesis of a crystalline (1-->3,1-->4)-beta-D-glucan by a mutated (1-->3,1-->4)-beta-D-glucanase from Bacillus.

PubMed Central

Faijes, Magda; Imai, Tomoya; Bulone, Vincent; Planas, Antoni

2004-01-01

Oligo- and poly-saccharides have a large number of important biological functions, and they occur in natural composite materials, such as plant cell walls, where they self-assemble during biosynthesis in a poorly understood manner. They can also be used for the formation of artificial composite materials with industrial applications. Fundamental and applied research in biology and nanobiotechnology would benefit from the possibility of synthesizing tailor-made oligo-/poly-saccharides. In the present paper, we demonstrate that such syntheses are possible using genetically modified glycoside hydrolases, i.e. glycosynthases. The ability of the endoglycosynthase derived from Bacillus (1-->3,1-->4)-beta-D-glucanase to catalyse self-condensation of sugar donors was exploited for the in vitro synthesis of a regular polysaccharide. The specificity of the enzyme allowed the polymerization of alpha-laminaribiosyl fluoride via the formation of (1-->4)-beta-linkages to yield a new linear crystalline (1-->3,1-->4)-beta-D-glucan with a repeating 4betaG3betaG unit. MS and methylation analyses indicated that the in vitro product consisted of a mixture of oligosaccharides, the one having a degree of polymerization of 12 being the most abundant. Morphological characterization revealed that the (1-->3,1-->4)-beta-D-glucan forms spherulites which are composed of platelet crystals. X-ray and electron diffraction analyses allowed the proposition of a putative crystallographic structure which corresponds to a monoclinic unit cell with a =0.834 nm, b =0.825 nm, c =2.04 nm and gamma=90.5 degrees. The dimensions of the ab plane are similar to those of cellulose I(beta), but the length of the c -axis is nearly twice that of cellulose I. It is proposed that four glucose residues are present in an extended conformation along the c -axis of the unit cell. The data presented show that glycosynthases represent promising enzymic systems for the synthesis of novel polysaccharides with specific and controlled structures, and for the analysis in vitro of the mechanisms of polymerization and crystallization of polysaccharides. PMID:15038792

Performance and Safety Testing of Varta Li-Ion Polymer Cells

NASA Technical Reports Server (NTRS)

Patel, Pranav; Jeevarajan, Judith

2009-01-01

Varta Cell Characteristics: Voltage : 3.7 V Capacity : 1.21 Ah Dimensions : 5mm X 37mm X 38.5 mm MOSFET switches for Overvoltage and Undervoltage. Initial Screening Results 29 Cells delivered: Statistics on Ph ysical Screening: Thickness (mm): Average- 5.08; Weight(g)- 22.8938; OCV (V)- 3.787; CCV (V)- 3.491.

From Learning Object to Learning Cell: A Resource Organization Model for Ubiquitous Learning

ERIC Educational Resources Information Center

Yu, Shengquan; Yang, Xianmin; Cheng, Gang; Wang, Minjuan

2015-01-01

This paper presents a new model for organizing learning resources: Learning Cell. This model is open, evolving, cohesive, social, and context-aware. By introducing a time dimension into the organization of learning resources, Learning Cell supports the dynamic evolution of learning resources while they are being used. In addition, by introducing a…

The Star Schema Benchmark and Augmented Fact Table Indexing

NASA Astrophysics Data System (ADS)

O'Neil, Patrick; O'Neil, Elizabeth; Chen, Xuedong; Revilak, Stephen

We provide a benchmark measuring star schema queries retrieving data from a fact table with Where clause column restrictions on dimension tables. Clustering is crucial to performance with modern disk technology, since retrievals with filter factors down to 0.0005 are now performed most efficiently by sequential table search rather than by indexed access. DB2’s Multi-Dimensional Clustering (MDC) provides methods to "dice" the fact table along a number of orthogonal "dimensions", but only when these dimensions are columns in the fact table. The diced cells cluster fact rows on several of these "dimensions" at once so queries restricting several such columns can access crucially localized data, with much faster query response. Unfortunately, columns of dimension tables of a star schema are not usually represented in the fact table. In this paper, we show a simple way to adjoin physical copies of dimension columns to the fact table, dicing data to effectively cluster query retrieval, and explain how such dicing can be achieved on database products other than DB2. We provide benchmark measurements to show successful use of this methodology on three commercial database products.

Drafting. Advanced Print Reading--Electrical.

ERIC Educational Resources Information Center

Oregon State Dept. of Education, Salem.

This document is a workbook for drafting students learning advanced print reading for electricity applications. The workbook contains seven units covering the following material: architectural working drawings; architectural symbols and dimensions; basic architectural electrical symbols; wiring symbols; riser diagrams; schematic diagrams; and…

Learning about the Unit Cell and Crystal Lattice with Computerized Simulations and Games: A Pilot Study

ERIC Educational Resources Information Center

Luealamai, Sutha; Panijpan, Bhinyo

2012-01-01

The authors have developed a computer-based learning module on the unit cell of various types of crystal. The module has two components: the virtual unit cell (VUC) part and the subsequent unit cell hunter part. The VUC is a virtual reality simulation for students to actively arrive at the unit cell from exploring, from a broad view, the crystal…

Care needs of older patients in the intensive care units.

PubMed

Chang, Ching-Wen; Chen, Yuh-Min; Su, Ching-Ching

2012-03-01

To explore the care needs of older patients in the intensive care units. Background.  As the numbers of older patients admitted to the intensive care units are growing, care quality of critically ill older patients has become an important issue. However, there are few studies directly investigating perceived care needs of hospitalised older patients and the studies on care needs of older patients in the intensive care units are even fewer. The identification of care needs from older patients' perspective will help develop qualified nursing practice. A qualitative exploratory design. Purposive sampling was performed to recruit 35 older patients from three hospitals in Taiwan. The interview transcripts were analysed by qualitative content analysis. The results revealed that care needs of older patients in the intensive care units are multidimensional, including physical, informational and psychosocial dimensions. Older patients' needs of the physical dimension included relieving pain and discomfort, starting oral intake as soon as possible and having continuous sleep. Informational needs included adequate explanations about their disease progression and prognosis and information on recovery-promoting activity. Psychosocial needs included caring behaviour of intensive care units staff, flexible visiting hours, increase in control ability and maintenance of good communication with intensive care units staff. The findings can assist nurses in understanding the interventions necessary to meet care needs of critically ill older patients. The critically ill older adults need more than medical-technical care. They need more holistic care. The psychosocial and informational needs must be considered commensurate with the presenting physical needs. Nurses have an important role in meeting intensive care units older patients' care needs. Intensive care units nurses should conduct comprehensive assessment regarding older patients' needs at the beginning and at various points in their intensive care units stay and match these needs with appropriate nursing interventions. © 2011 Blackwell Publishing Ltd.

The relationship between patient safety climate and occupational safety climate in healthcare - A multi-level investigation.

PubMed

Pousette, Anders; Larsman, Pernilla; Eklöf, Mats; Törner, Marianne

2017-06-01

Patient safety climate/culture is attracting increasing research interest, but there is little research on its relation with organizational climates regarding other target domains. The aim of this study was to investigate the relationship between patient safety climate and occupational safety climate in healthcare. The climates were assessed using two questionnaires: Hospital Survey on Patient Safety Culture and Nordic Occupational Safety Climate Questionnaire. The final sample consisted of 1154 nurses, 886 assistant nurses, and 324 physicians, organized in 150 work units, within hospitals (117units), primary healthcare (5units) and elderly care (28units) in western Sweden, which represented 56% of the original sample contacted. Within each type of safety climate, two global dimensions were confirmed in a higher order factor analysis; one with an external focus relative the own unit, and one with an internal focus. Two methods were used to estimate the covariation between the global climate dimensions, in order to minimize the influence of bias from common method variance. First multilevel analysis was used for partitioning variances and covariances in a within unit part (individual level) and a between unit part (unit level). Second, a split sample technique was used to calculate unit level correlations based on aggregated observations from different respondents. Both methods showed associations similar in strength between the patient safety climate and the occupational safety climate domains. The results indicated that patient safety climate and occupational safety climate are strongly positively related at the unit level, and that the same organizational processes may be important for the development of both types of organizational climate. Safety improvement interventions should not be separated in different organizational processes, but be planned so that both patient safety and staff safety are considered concomitantly. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.

A powder neutron diffraction study of the crystal structure of the fluoroperovskite NaMgF3 (neighborite) from 300 to 3.6 K

NASA Astrophysics Data System (ADS)

Mitchell, Roger H.; Alexander, Malcolm; Cranswick, Lachlan M. D.; Swainson, Ian P.

2007-12-01

The cell dimensions and crystal structures of the fluoroperovskite NaMgF3 (neighborite), synthesized by solid state methods, have been determined by powder neutron diffraction and Rietveld refinement over the temperature range 300 3.6 K using Pt metal as an internal standard for calibration of the neutron wavelength. These data show that Pbnm NaMgF3 does not undergo any phase transitions to structures of lower symmetry with decreasing temperature. The cell dimensions and atomic coordinates together with polyhedron volumes and distortion indices are given for Pbnm NaMgF3 at 25 K intervals from 300 to 3.6 K. Decreases in the a and c cell dimensions reach a saturation point at 50 K, whereas the b dimension becomes saturated at 150 K. The distortion of the structure of Pbnm NaMgF3 from the aristotype cubic Pmifmmodeexpandafterbarelseexpandafter\\=fi{3}m structure is described in terms of the tilting of the MgF6 octahedra according to the tilt scheme a - a - c + . With decreasing temperature the antiphase tilt ( a -) increases from 14.24° to 15.39°, whereas the in-phase tilt ( c + ) remains effectively constant at ˜10.7°. Changes in the tilt angles are insufficient to cause changes in the coordination sphere of Na that might induce a low temperature phase transition. The structure of Pbnm NaMgF3 is also described in terms of normal mode analysis and displacements of the condensed normal modes are compared with those of Pbnm KCaF3.

The nature and role of advection in advection-diffusion equations used for modelling bed load transport

NASA Astrophysics Data System (ADS)

Ancey, Christophe; Bohorquez, Patricio; Heyman, Joris

2016-04-01

The advection-diffusion equation arises quite often in the context of sediment transport, e.g., for describing time and space variations in the particle activity (the solid volume of particles in motion per unit streambed area). Stochastic models can also be used to derive this equation, with the significant advantage that they provide information on the statistical properties of particle activity. Stochastic models are quite useful when sediment transport exhibits large fluctuations (typically at low transport rates), making the measurement of mean values difficult. We develop an approach based on birth-death Markov processes, which involves monitoring the evolution of the number of particles moving within an array of cells of finite length. While the topic has been explored in detail for diffusion-reaction systems, the treatment of advection has received little attention. We show that particle advection produces nonlocal effects, which are more or less significant depending on the cell size and particle velocity. Albeit nonlocal, these effects look like (local) diffusion and add to the intrinsic particle diffusion (dispersal due to velocity fluctuations), with the important consequence that local measurements depend on both the intrinsic properties of particle displacement and the dimensions of the measurement system.

An Evaluation and Ranking of Children’s Hospital Websites in the United States

PubMed Central

Walker, Daniel M; Ford, Eric W

2016-01-01

Background Children’s hospitals are faced with the rising need for technological innovation. Their prospective health care consumers, who increasingly depend on the Web and social media for communication and consumer engagement, drive this need. As patients and family members navigate the Web presence of hospitals, it is important for these specialized organizations to present themselves and their services efficiently. Objective The purpose of this study was to evaluate the website content of children’s hospitals in order to identify opportunities to improve website design and create benchmarks to judge improvement. Methods All websites associated with a children’s hospital were identified using a census list of all children’s hospitals in the United States. In March of 2014, each website and its social media were evaluated using a Web crawler that provided a 5-dimensional assessment that included website accessibility, marketing, content, technology, and usability. The 5-dimensional assessment was scored on a scale ranging from 0 to 10 with positive findings rated higher on the scale. Websites were ranked by individual dimensions as well as according to their average ranking across all dimensions. Results Mean scores of 153 websites ranged from 5.05 to 8.23 across all 5 dimensions. Results revealed that no website scored a perfect 10 on any dimension and that room exists for meaningful improvement. Conclusions Study findings allow for the establishment of baseline benchmarks for tracking future website and social media improvements and display the need for enhanced Web-based consumer engagement for children’s hospitals. PMID:27549074

The relationship between emotional regulation and eating behaviour: a multidimensional analysis of obesity psychopathology.

PubMed

Micanti, Fausta; Iasevoli, Felice; Cucciniello, Claudia; Costabile, Raimondo; Loiarro, Giuseppe; Pecoraro, Giuseppe; Pasanisi, Fabrizio; Rossetti, GianLuca; Galletta, Diana

2017-03-01

The aim of this study is to show that the differences among eating behaviours are related to the emotional dysregulation connected to the mental dimensions being part of the obese psychopathology. Eating behaviours can be considered a diagnostic feature at the initial screening for determining the obesity treatment: nutritional or bariatric surgery. 1828 Obese subjects underwent psychiatric assessment before entering obesity nutritional treatment or bariatric surgery following the multidisciplinary programme. 1121 subjects were selected and enrolled in this study: 850 were inpatients visited or hospitalised at the Obesity Centre or at the Bariatric Surgery Units, 271 were outpatients visited at the Eating Disorder and Obesity Unit. Psychiatric examination was used to exclude psychiatric disorders and investigate eating behaviours distinguished on the basis of food intake rhythm in: gorging, snacking, grazing and binge. They are related to the mental dimensions: impulsiveness, body image, mood and anxiety, taking part in the emotional regulation system. Specific psychometric tools were used to investigate the different mental dimensions of the single eating behaviours and their differences. Statistical analysis of the psychopathological features was performed using ANOVA, ANCOVA, Levene test, Bonferroni's and Tamhane post hoc test. Significance was set at p < 0.05. Data analysis shows significant differences of psychopathology among all the eating behaviours and an increase in the emotional dysregulation determining maladaptive behaviours. Eating behaviours are connected to the balance of the different features of mental dimensions implicated in the emotional regulation system. They could provide significant clinical information and therefore be part of the obesity diagnostic criteria and therapeutic programme.

Providing Doctors With High-Quality Information: An Updated Evaluation of Web-Based Point-of-Care Information Summaries

PubMed Central

Kwag, Koren Hyogene; González-Lorenzo, Marien; Banzi, Rita; Bonovas, Stefanos

2016-01-01

Background The complexity of modern practice requires health professionals to be active information-seekers. Objective Our aim was to review the quality and progress of point-of-care information summaries—Web-based medical compendia that are specifically designed to deliver pre-digested, rapidly accessible, comprehensive, and periodically updated information to health care providers. We aimed to evaluate product claims of being evidence-based. Methods We updated our previous evaluations by searching Medline, Google, librarian association websites, and conference proceedings from August 2012 to December 2014. We included Web-based, regularly updated point-of-care information summaries with claims of being evidence-based. We extracted data on the general characteristics and content presentation of products, and we quantitatively assessed their breadth of disease coverage, editorial quality, and evidence-based methodology. We assessed potential relationships between these dimensions and compared them with our 2008 assessment. Results We screened 58 products; 26 met our inclusion criteria. Nearly a quarter (6/26, 23%) were newly identified in 2014. We accessed and analyzed 23 products for content presentation and quantitative dimensions. Most summaries were developed by major publishers in the United States and the United Kingdom; no products derived from low- and middle-income countries. The main target audience remained physicians, although nurses and physiotherapists were increasingly represented. Best Practice, Dynamed, and UptoDate scored the highest across all dimensions. The majority of products did not excel across all dimensions: we found only a moderate positive correlation between editorial quality and evidence-based methodology (r=.41, P=.0496). However, all dimensions improved from 2008: editorial quality (P=.01), evidence-based methodology (P=.015), and volume of diseases and medical conditions (P<.001). Conclusions Medical and scientific publishers are investing substantial resources towards the development and maintenance of point-of-care summaries. The number of these products has increased since 2008 along with their quality. Best Practice, Dynamed, and UptoDate scored the highest across all dimensions, while others that were marketed as evidence-based were less reliable. Individuals and institutions should regularly assess the value of point-of-care summaries as their quality changes rapidly over time. PMID:26786976

Providing Doctors With High-Quality Information: An Updated Evaluation of Web-Based Point-of-Care Information Summaries.

PubMed

Kwag, Koren Hyogene; González-Lorenzo, Marien; Banzi, Rita; Bonovas, Stefanos; Moja, Lorenzo

2016-01-19

The complexity of modern practice requires health professionals to be active information-seekers. Our aim was to review the quality and progress of point-of-care information summaries-Web-based medical compendia that are specifically designed to deliver pre-digested, rapidly accessible, comprehensive, and periodically updated information to health care providers. We aimed to evaluate product claims of being evidence-based. We updated our previous evaluations by searching Medline, Google, librarian association websites, and conference proceedings from August 2012 to December 2014. We included Web-based, regularly updated point-of-care information summaries with claims of being evidence-based. We extracted data on the general characteristics and content presentation of products, and we quantitatively assessed their breadth of disease coverage, editorial quality, and evidence-based methodology. We assessed potential relationships between these dimensions and compared them with our 2008 assessment. We screened 58 products; 26 met our inclusion criteria. Nearly a quarter (6/26, 23%) were newly identified in 2014. We accessed and analyzed 23 products for content presentation and quantitative dimensions. Most summaries were developed by major publishers in the United States and the United Kingdom; no products derived from low- and middle-income countries. The main target audience remained physicians, although nurses and physiotherapists were increasingly represented. Best Practice, Dynamed, and UptoDate scored the highest across all dimensions. The majority of products did not excel across all dimensions: we found only a moderate positive correlation between editorial quality and evidence-based methodology (r=.41, P=.0496). However, all dimensions improved from 2008: editorial quality (P=.01), evidence-based methodology (P=.015), and volume of diseases and medical conditions (P<.001). Medical and scientific publishers are investing substantial resources towards the development and maintenance of point-of-care summaries. The number of these products has increased since 2008 along with their quality. Best Practice, Dynamed, and UptoDate scored the highest across all dimensions, while others that were marketed as evidence-based were less reliable. Individuals and institutions should regularly assess the value of point-of-care summaries as their quality changes rapidly over time.

How does patient safety culture in the operating room and post-anesthesia care unit compare to the rest of the hospital?

PubMed

Kaafarani, Haytham M A; Itani, Kamal M F; Rosen, Amy K; Zhao, Shibei; Hartmann, Christine W; Gaba, David M

2009-07-01

A strong patient safety culture in the operating room (OR) and post-anesthesia care unit (PACU) is essential to promote safe care. The Patient Safety Climate in Healthcare Organizations (PSCHO) survey was administered to employees at 30 Veterans Affairs (VA) hospitals. The survey consisted of 42 close-ended items representing 12 different dimensions of safety. We measured percent problematic response (PPR); higher PPR values reflect weaker safety culture. The "OR/PACU" and the "Other Work Areas" groups' item-specific, dimension-specific, and overall problematic responses were compared. The overall and dimension-specific PPRs were similar between the OR/PACU and the Other Work Areas group (overall: 20.2% and 18.1%, respectively; P = .41). When the 2 groups were compared on an item-by-item level, the OR/PACU staff reported more frequent witnessing of unsafe patient care (PPR 55.1% vs 43.2%; P = .01), and perceived less understanding by senior leadership of clinical care (PPR 28.3% vs 17.1%; P = .01) and less hospital interest in quality of care (PPR 20.4% vs 12.5%; P = .03). Specific areas of safety culture in the OR/PACU were found that should be targeted for improvement.

Structured Ordinary Least Squares: A Sufficient Dimension Reduction approach for regressions with partitioned predictors and heterogeneous units.

PubMed

Liu, Yang; Chiaromonte, Francesca; Li, Bing

2017-06-01

In many scientific and engineering fields, advanced experimental and computing technologies are producing data that are not just high dimensional, but also internally structured. For instance, statistical units may have heterogeneous origins from distinct studies or subpopulations, and features may be naturally partitioned based on experimental platforms generating them, or on information available about their roles in a given phenomenon. In a regression analysis, exploiting this known structure in the predictor dimension reduction stage that precedes modeling can be an effective way to integrate diverse data. To pursue this, we propose a novel Sufficient Dimension Reduction (SDR) approach that we call structured Ordinary Least Squares (sOLS). This combines ideas from existing SDR literature to merge reductions performed within groups of samples and/or predictors. In particular, it leads to a version of OLS for grouped predictors that requires far less computation than recently proposed groupwise SDR procedures, and provides an informal yet effective variable selection tool in these settings. We demonstrate the performance of sOLS by simulation and present a first application to genomic data. The R package "sSDR," publicly available on CRAN, includes all procedures necessary to implement the sOLS approach. © 2016, The International Biometric Society.

Dimensions of operational stress and forms of unacceptable risk taking with small arms and munitions.

PubMed

Ben-Shalom, Uzi

2015-01-01

Accidents with small arms and munitions during deployment is a significant safety concern for leaders and safety specialists in combat units. Operational stress may lead to forms of unacceptable risk taking with small arms that may underlie some of these accidents. The present research studied the correlation between two dimensions of operational stress, two forms of risk taking with small arms among combat unit soldiers and possible mediators. The dimensions of operational threat, negative affect and personality profile from the EPQ-R-S were predictors; "exaggerated preparedness" and "risky games with small arms and munitions" were dependent variables; safety climate of the platoon served as a mediator variable. The participants were 461 compulsory service combat soldiers in 31 companies. This field study was conducted during period of top security alert. The results reveal that perceived threat is indeed correlated with exaggerated operational preparedness whereas general emotional state was correlated with risky games with small arms. Safety climate mediated only the correlation between general emotional state and risky games with small arms and munitions. Preparedness and risky games were predicted by the interaction of Psychoticism and the Lie Scale from the EPQ-R-S. The results may enhance the efforts in reducing risk taking and prevention of accidents with small arms and munitions during and following deployment.

Contribution of high-resolution correlative imaging techniques in the study of the liver sieve in three-dimensions.

PubMed

Braet, Filip; Wisse, Eddie; Bomans, Paul; Frederik, Peter; Geerts, Willie; Koster, Abraham; Soon, Lilian; Ringer, Simon

2007-03-01

Correlative microscopy has become increasingly important for the analysis of the structure, function, and dynamics of cells. This is largely due to the result of recent advances in light-, probe-, laser- and various electron microscopy techniques that facilitate three-dimensional studies. Furthermore, the improved understanding in the past decade of imaging cell compartments in the third dimension has resulted largely from the availability of powerful computers, fast high-resolution CCD cameras, specifically developed imaging analysis software, and various probes designed for labeling living and or fixed cells. In this paper, we review different correlative high-resolution imaging methodologies and how these microscopy techniques facilitated the accumulation of new insights in the morpho-functional and structural organization of the hepatic sieve. Various aspects of hepatic endothelial fenestrae regarding their structure, origin, dynamics, and formation will be explored throughout this paper by comparing the results of confocal laser scanning-, correlative fluorescence and scanning electron-, atomic force-, and whole-mount electron microscopy. Furthermore, the recent advances of vitrifying cells with the vitrobot in combination with the glove box for the preparation of cells for cryo-electron microscopic investigation will be discussed. Finally, the first transmission electron tomography data of the liver sieve in three-dimensions are presented. The obtained data unambiguously show the involvement of special domains in the de novo formation and disappearance of hepatic fenestrae, and focuses future research into the (supra)molecular structure of the fenestrae-forming center, defenestration center and fenestrae-, and sieve plate cytoskeleton ring by using advanced cryo-electron tomography. (c) 2007 Wiley-Liss, Inc.

Spatial dimensions of the electron diffusion region in anti-parallel magnetic reconnection

NASA Astrophysics Data System (ADS)

Nakamura, Takuma; Nakamura, Rumi; Haseagwa, Hiroshi

2016-03-01

Spatial dimensions of the detailed structures of the electron diffusion region in anti-parallel magnetic reconnection were analyzed based on two-dimensional fully kinetic particle-in-cell simulations. The electron diffusion region in this study is defined as the region where the positive reconnection electric field is sustained by the electron inertial and non-gyrotropic pressure components. Past kinetic studies demonstrated that the dimensions of the whole electron diffusion region and the inner non-gyrotropic region are scaled by the electron inertial length de and the width of the electron meandering motion, respectively. In this study, we successfully obtained more precise scalings of the dimensions of these two regions than the previous studies by performing simulations with sufficiently small grid spacing (1/16-1/8 de) and a sufficient number of particles (800 particles cell-1 on average) under different conditions changing the ion-to-electron mass ratio, the background density and the electron βe (temperature). The obtained scalings are adequately supported by some theories considering spatial variations of field and plasma parameters within the diffusion region. In the reconnection inflow direction, the dimensions of both regions are proportional to de based on the background density. Both dimensions also depend on βe based on the background values, but the dependence in the inner region ( ˜ 0.375th power) is larger than the whole region (0.125th power) reflecting the orbits of meandering and accelerated electrons within the inner region. In the outflow direction, almost only the non-gyrotropic component sustains the positive reconnection electric field. The dimension of this single-scale diffusion region is proportional to the ion-electron hybrid inertial length (dide)1/2 based on the background density and weakly depends on the background βe with the 0.25th power. These firm scalings allow us to predict observable dimensions in real space which are indeed in reasonable agreement with past in situ spacecraft observations in the Earth's magnetotail and have important implications for future observations with higher resolutions such as the NASA Magnetospheric Multiscale (MMS) mission.

Grid generation in three dimensions by Poisson equations with control of cell size and skewness at boundary surfaces

NASA Technical Reports Server (NTRS)

Sorenson, R. L.; Steger, J. L.

1983-01-01

An algorithm for generating computational grids about arbitrary three-dimensional bodies is developed. The elliptic partial differential equation (PDE) approach developed by Steger and Sorenson and used in the NASA computer program GRAPE is extended from two to three dimensions. Forcing functions which are found automatically by the algorithm give the user the ability to control mesh cell size and skewness at boundary surfaces. This algorithm, as is typical of PDE grid generators, gives smooth grid lines and spacing in the interior of the grid. The method is applied to a rectilinear wind-tunnel case and to two body shapes in spherical coordinates.

Reliable Cellular Automata with Self-Organization

NASA Astrophysics Data System (ADS)

Gács, Peter

2001-04-01

In a probabilistic cellular automaton in which all local transitions have positive probability, the problem of keeping a bit of information indefinitely is nontrivial, even in an infinite automaton. Still, there is a solution in 2 dimensions, and this solution can be used to construct a simple 3-dimensional discrete-time universal fault-tolerant cellular automaton. This technique does not help much to solve the following problems: remembering a bit of information in 1 dimension; computing in dimensions lower than 3; computing in any dimension with non-synchronized transitions. Our more complex technique organizes the cells in blocks that perform a reliable simulation of a second (generalized) cellular automaton. The cells of the latter automaton are also organized in blocks, simulating even more reliably a third automaton, etc. Since all this (a possibly infinite hierarchy) is organized in "software," it must be under repair all the time from damage caused by errors. A large part of the problem is essentially self-stabilization recovering from a mess of arbitrary size and content. The present paper constructs an asynchronous one-dimensional fault-tolerant cellular automaton, with the further feature of "self-organization." The latter means that unless a large amount of input information must be given, the initial configuration can be chosen homogeneous.

Holland in Iceland revisited: an emic approach to evaluating U.S. vocational interest models.

PubMed

Einarsdóttir, Sif; Rounds, James; Su, Rong

2010-07-01

An emic approach was used to test the structural validity and applicability of Holland's (1997) RIASEC (Realistic, Investigative, Artistic, Social, Enterprising, Conventional) model in Iceland. Archival data from the development of the Icelandic Interest Inventory (Einarsdóttir & Rounds, 2007) were used in the present investigation. The data included an indigenous pool of occupations and work-task items representing Iceland's world of work that had been administered to a sample of 597 upper secondary school students. Multidimensional scaling analysis and property vector fitting using Prediger's (1981) work-task dimensions were applied to the item responses to test if the RIASEC model could be identified. The results indicated that a 4-dimensional solution better explains the interest space in Iceland than Holland's 2-dimensional RIASEC representation. The work-task dimension of People-Things and the Sex-Type and Prestige dimensions were located in the 1st and 2nd dimensions of the multidimensional scaling solution, but Data-Ideas, a dimension critical to the RIASEC model, was not. The 3rd and 4th dimensions did not correspond to any dimensions previously detected in structural studies in the United States and seem to be related to specific ecological, cultural, and political forces in Iceland. These results demonstrate the importance of selecting representative indigenous occupations and work tasks when evaluating the RIASEC model. The present study is an example of the next step in a comprehensive cross-cultural research program on vocational interests, an emic investigation. (c) 2010 APA, all rights reserved.

Death by Segregation: Does the Dimension of Racial Segregation Matter?

PubMed

Yang, Tse-Chuan; Matthews, Stephen A

2015-01-01

The county-level geographic mortality differentials have persisted in the past four decades in the United States (US). Though several socioeconomic factors (e.g., inequality) partially explain this phenomenon, the role of race/ethnic segregation, in general, and the different dimensions of segregation, more specifically, has been underexplored. Focusing on all-cause age-sex standardized US county-level mortality (2004-2008), this study has two substantive goals: (1) to understand whether segregation is a determinant of mortality and if yes, how the relationship between segregation and mortality varies by racial/ethnic dyads (e.g., white/black), and (2) to explore whether different dimensions of segregation (i.e., evenness, exposure, concentration, centralization, and clustering) are associated with mortality. A third goal is methodological: to assess whether spatial autocorrelation influences our understanding of the associations between the dimensions of segregation and mortality. Race/ethnic segregation was found to contribute to the geographic mortality disparities. Moreover, the relationship with mortality differed by both race/ethnic group and the dimension of segregation. Specifically, white/black segregation is positively related to mortality, whereas the segregation between whites and non-black minorities is negatively associated with mortality. Among the five dimensions of segregation, evenness and exposure are more strongly related to mortality than other dimensions. Spatial filtering approaches also identified six unique spatial patterns that significantly affect the spatial distribution of mortality. These patterns offer possible insights that help identify omitted variables related to the persistent patterning of mortality in the US.

An accelerated framework for the classification of biological targets from solid-state micropore data.

PubMed

Hanif, Madiha; Hafeez, Abdul; Suleman, Yusuf; Mustafa Rafique, M; Butt, Ali R; Iqbal, Samir M

2016-10-01

Micro- and nanoscale systems have provided means to detect biological targets, such as DNA, proteins, and human cells, at ultrahigh sensitivity. However, these devices suffer from noise in the raw data, which continues to be significant as newer and devices that are more sensitive produce an increasing amount of data that needs to be analyzed. An important dimension that is often discounted in these systems is the ability to quickly process the measured data for an instant feedback. Realizing and developing algorithms for the accurate detection and classification of biological targets in realtime is vital. Toward this end, we describe a supervised machine-learning approach that records single cell events (pulses), computes useful pulse features, and classifies the future patterns into their respective types, such as cancerous/non-cancerous cells based on the training data. The approach detects cells with an accuracy of 70% from the raw data followed by an accurate classification when larger training sets are employed. The parallel implementation of the algorithm on graphics processing unit (GPU) demonstrates a speedup of three to four folds as compared to a serial implementation on an Intel Core i7 processor. This incredibly efficient GPU system is an effort to streamline the analysis of pulse data in an academic setting. This paper presents for the first time ever, a non-commercial technique using a GPU system for realtime analysis, paired with biological cluster targeting analysis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Analogue solution for electrical capacity of membrane covered square cylinders in square array at high concentration.

PubMed

Cole, K S

1975-12-01

Analytical solutions of Laplace equations have given the electrical characteristics of membranes and interiors of spherical, ellipsoidal, and cylindrical cells in suspensions and tissues from impedance measurements, but the underlying assumptions may be invalid above 50% volume concentrations. However, resistance measurements on several nonconducting, close-packing forms in two and three dimensions closely predicted volume concentrations up to 100% by equations derived from Maxwell and Rayleigh. Calculations of membrane capacities of cells in suspensions and tissues from extensions of theory, as developed by Fricke and by Cole, have been useful but of unknown validity at high concentrations. A resistor analogue has been used to solve the finite difference approximation to the Laplace equation for the resistance and capacity of a square array of square cylindrical cells with surface capacity. An 11 x 11 array of resistors, simulating a quarter of the unit structure, was separated into intra- and extra-cellular regions by rows of capacitors corresponding to surface membrane areas from 3 x 3 to 11 x 11 or 7.5% to 100%. The extended Rayleigh equation predicted the cell concentrations and membrane capacities to within a few percent from boundary resistance and capacity measurements at low frequencies. This single example suggests that analytical solutions for other, similar two- and three-dimensional problems may be approximated up to near 100% concentrations and that there may be analytical justifications for such analogue solutions of Laplace equations.

Structure and spectra of H/sub 2/O in hydrated. beta. -alumina

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

Bates, J.B.; Dudney, N.J.; Brown, G.M.

1982-11-15

The structure and spectra of hydrated Li and Na ..beta..-alumina were investigated using neutron diffraction, infrared absorption, and Raman scattering. The dimensions of the hexagonal unit cell of a hydrated Li ..beta..-alumina crystal containing 1.55 H/sub 2/O molecules per unit cell are a = 5.591 A and c = 22.715 A. The oxygen atoms of the water molecules are located in the conduction plane between the mO, and the aBR sites; the protons, located above the below the plane, form bent hydrogen bonds with the O(4) oxygen ions. The HOH bond angle of water in Li ..beta..-alumina is 114/sup 0/more » and the Vertical BarO--HVertical Bar bond distance is 0.992 A. Based on polarized infrared spectra, H/sub 2/O adopts a similar structure and orientation in Na ..beta..-alumina. Spectra of absorbed H/sub 2/O, D/sub 2/O, and HDO species show that water molecules dissociate in Li ..beta..-alumina to form OH/sup -/ and H(H/sub 2/O)/sup +//sub n/ species. No evidence was found for the dissociation of water in Na ..beta..-alumina. The absorption coefficients determined for OH/sup -/ and H/sub 2/O in Li ..beta..-alumina include local field corrections. A large local field anisotropy at the protons of H/sub 2/O is responsible for the large ratio of the intensities of ..nu../sub 3/ and ..nu../sub 1/ observed for water in Li and Na ..beta..-alumina.« less

Atomic Scale Control of Competing Electronic Phases in Ultrathin Correlated Oxides

NASA Astrophysics Data System (ADS)

Shen, Kyle

2015-03-01

Ultrathin epitaxial thin films offer a number of unique advantages for engineering the electronic properties of correlated transition metal oxides. For example, atomically thin films can be synthesized to artificially confine electrons in two dimensions. Furthermore, using a substrate with a mismatched lattice constant can impose large biaxial strains of larger than 3% (Δa / a), much larger than can achieved in bulk single crystals. Since these dimensionally confined or strained systems may necessarily be less than a few unit cells thick, investigating their properties and electronic structure can be particularly challenging. We employ a combination of reactive oxide molecular beam epitaxy (MBE) and angle-resolved photoemission spectroscopy (ARPES) to investigate how dimensional confinement and epitaxial strain can be used to manipulate electronic properties and structure in correlated transition metal oxide thin films. We describe some of our recent work manipulating and studying the electronic structure of ultrathin LaNiO3 through a thickness-driven metal-insulator transition between three and two unit cells (Nature Nanotechnology 9, 443, 2014), where coherent Fermi liquid-like quasiparticles are suppressed at the metal-insulator transition observed in transport. We also will describe some recent unpublished work using epitaxial strain to drive a Lifshitz transition in atomically thin films of the spin-triplet ruthenate superconductor Sr2RuO4, where we also can dramatically alter the quasiparticle scattering rates and drive the system towards non-Fermi liquid behavior near the critical point (B. Burganov, C. Adamo, in preparation). Funding provided by the Office of Naval Research and Air Force Office of Scientific Research.

Voltage gating by molecular subunits of Na+ and K+ ion channels: higher-dimensional cubic kinetics, rate constants, and temperature

PubMed Central

2015-01-01

The structural similarity between the primary molecules of voltage-gated Na and K channels (alpha subunits) and activation gating in the Hodgkin-Huxley model is brought into full agreement by increasing the model's sodium kinetics to fourth order (m3 → m4). Both structures then virtually imply activation gating by four independent subprocesses acting in parallel. The kinetics coalesce in four-dimensional (4D) cubic diagrams (16 states, 32 reversible transitions) that show the structure to be highly failure resistant against significant partial loss of gating function. Rate constants, as fitted in phase plot data of retinal ganglion cell excitation, reflect the molecular nature of the gating transitions. Additional dimensions (6D cubic diagrams) accommodate kinetically coupled sodium inactivation and gating processes associated with beta subunits. The gating transitions of coupled sodium inactivation appear to be thermodynamically irreversible; response to dielectric surface charges (capacitive displacement) provides a potential energy source for those transitions and yields highly energy-efficient excitation. A comparison of temperature responses of the squid giant axon (apparently Arrhenius) and mammalian channel gating yields kinetic Q10 = 2.2 for alpha unit gating, whose transitions are rate-limiting at mammalian temperatures; beta unit kinetic Q10 = 14 reproduces the observed non-Arrhenius deviation of mammalian gating at low temperatures; the Q10 of sodium inactivation gating matches the rate-limiting component of activation gating at all temperatures. The model kinetics reproduce the physiologically large frequency range for repetitive firing in ganglion cells and the physiologically observed strong temperature dependence of recovery from inactivation. PMID:25867741

3D modeling of cancer stem cell niche

PubMed Central

He, Jun; Xiong, Li; Li, Qinglong; Lin, Liangwu; Miao, Xiongying; Yan, Shichao; Hong, Zhangyong; Yang, Leping; Wen, Yu; Deng, Xiyun

2018-01-01

Cancer stem cells reside in a distinct microenvironment called niche. The reciprocal interactions between cancer stem cells and niche contribute to the maintenance and enrichment of cancer stem cells. In order to simulate the interactions between cancer stem cells and niche, three-dimensional models have been developed. These in vitro culture systems recapitulate the spatial dimension, cellular heterogeneity, and the molecular networks of the tumor microenvironment and show great promise in elucidating the pathophysiology of cancer stem cells and designing more clinically relavant treatment modalites. PMID:29416698

Characterization of solar cells for space applications. Volume 5: Electrical characteristics of OCLI 225-micron MLAR wraparound cells as a function of intensity, temperature, and irradiation

NASA Technical Reports Server (NTRS)

Anspaugh, B. E.; Miyahira, T. F.; Weiss, R. S.

1979-01-01

Computed statistical averages and standard deviations with respect to the measured cells for each intensity temperature measurement condition are presented. Display averages and standard deviations of the cell characteristics in a two dimensional array format are shown: one dimension representing incoming light intensity, and another, the cell temperature. Programs for calculating the temperature coefficients of the pertinent cell electrical parameters are presented, and postirradiation data are summarized.

Micropatterning of a nanoporous alumina membrane with poly(ethylene glycol) hydrogel to create cellular micropatterns on nanotopographic substrates.

PubMed

Lee, Hyun Jong; Kim, Dae Nyun; Park, Saemi; Lee, Yeol; Koh, Won-Gun

2011-03-01

In this paper, we describe a simple method for fabricating micropatterned nanoporous substrates that are capable of controlling the spatial positioning of mammalian cells. Micropatterned substrates were prepared by fabricating poly(ethylene glycol) (PEG) hydrogel microstructures on alumina membranes with 200 nm nanopores using photolithography. Because hydrogel precursor solution could infiltrate and become crosslinked within the nanopores, the resultant hydrogel micropatterns were firmly anchored on the substrate without the use of adhesion-promoting monolayers, thereby allow tailoring of the surface properties of unpatterned nanoporous areas. For mammalian cell patterning, arrays of microwells of different dimensions were fabricated. These microwells were composed of hydrophilic PEG hydrogel walls surrounding nanoporous bottoms that were modified with cell-adhesive Arg-Gly-Asp (RGD) peptides. Because the PEG hydrogel was non-adhesive towards proteins and cells, cells adhered selectively and remained viable within the RGD-modified nanoporous regions, thereby creating cellular micropatterns. Although the morphology of cell clusters and the number of cells inside one microwell were dependent on the lateral dimension of the microwells, adhered cells that were in direct contact with nanopores were able to penetrate into the nanopores by small extensions (filopodia) for all the different sizes of microwells evaluated. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Cancer cell migration within 3D layer-by-layer microfabricated photocrosslinked PEG scaffolds with tunable stiffness.

PubMed

Soman, Pranav; Kelber, Jonathan A; Lee, Jin Woo; Wright, Tracy N; Vecchio, Kenneth S; Klemke, Richard L; Chen, Shaochen

2012-10-01

Our current understanding of 3-dimensional (3D) cell migration is primarily based on results from fibrous scaffolds with randomly organized internal architecture. Manipulations that change the stiffness of these 3D scaffolds often alter other matrix parameters that can modulate cell motility independently or synergistically, making observations less predictive of how cells behave when migrating in 3D. In order to decouple microstructural influences and stiffness effects, we have designed and fabricated 3D polyethylene glycol (PEG) scaffolds that permit orthogonal tuning of both elastic moduli and microstructure. Scaffolds with log-pile architectures were used to compare the 3D migration properties of normal breast epithelial cells (HMLE) and Twist-transformed cells (HMLET). Our results indicate that the nature of cell migration is significantly impacted by the ability of cells to migrate in the third dimension. 2D ECM-coated PEG substrates revealed no statistically significant difference in cell migration between HMLE and HMLET cells among substrates of different stiffness. However, when cells were allowed to move along the third dimension, substantial differences were observed for cell displacement, velocity and path straightness parameters. Furthermore, these differences were sensitive to both substrate stiffness and the presence of the Twist oncogene. Importantly, these 3D modes of migration provide insight into the potential for oncogene-transformed cells to migrate within and colonize tissues of varying stiffness. Copyright © 2012 Elsevier Ltd. All rights reserved.

Analysis of Factors Limiting Bacterial Growth in PDMS Mother Machine Devices.

PubMed

Yang, Da; Jennings, Anna D; Borrego, Evalynn; Retterer, Scott T; Männik, Jaan

2018-01-01

The microfluidic mother machine platform has attracted much interest for its potential in studies of bacterial physiology, cellular organization, and cell mechanics. Despite numerous experiments and development of dedicated analysis software, differences in bacterial growth and morphology in narrow mother machine channels compared to typical liquid media conditions have not been systematically characterized. Here we determine changes in E. coli growth rates and cell dimensions in different sized dead-end microfluidic channels using high resolution optical microscopy. We find that E. coli adapt to the confined channel environment by becoming narrower and longer compared to the same strain grown in liquid culture. Cell dimensions decrease as the channel length increases and width decreases. These changes are accompanied by increases in doubling times in agreement with the universal growth law. In channels 100 μm and longer, cell doublings can completely stop as a result of frictional forces that oppose cell elongation. Before complete cessation of elongation, mechanical stresses lead to substantial deformation of cells and changes in their morphology. Our work shows that mechanical forces rather than nutrient limitation are the main growth limiting factor for bacterial growth in long and narrow channels.

Analysis of Factors Limiting Bacterial Growth in PDMS Mother Machine Devices

DOE PAGES

Yang, Da; Jennings, Anna D.; Borrego, Evalynn; ...

2018-05-01

The microfluidic mother machine platform has attracted much interest for its potential in studies of bacterial physiology, cellular organization, and cell mechanics. Despite numerous experiments and development of dedicated analysis software, differences in bacterial growth and morphology in narrow mother machine channels compared to typical liquid media conditions have not been systematically characterized. Here we determine changes in E. coli growth rates and cell dimensions in different sized dead-end microfluidic channels using high resolution optical microscopy. We find that E. coli adapt to the confined channel environment by becoming narrower and longer compared to the same strain grown in liquidmore » culture. Cell dimensions decrease as the channel length increases and width decreases. These changes are accompanied by increases in doubling times in agreement with the universal growth law. In channels 100 μm and longer, cell doublings can completely stop as a result of frictional forces that oppose cell elongation. Before complete cessation of elongation, mechanical stresses lead to substantial deformation of cells and changes in their morphology. Lastly, our work shows that mechanical forces rather than nutrient limitation are the main growth limiting factor for bacterial growth in long and narrow channels.« less

Analysis of Factors Limiting Bacterial Growth in PDMS Mother Machine Devices

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

Yang, Da; Jennings, Anna D.; Borrego, Evalynn

The microfluidic mother machine platform has attracted much interest for its potential in studies of bacterial physiology, cellular organization, and cell mechanics. Despite numerous experiments and development of dedicated analysis software, differences in bacterial growth and morphology in narrow mother machine channels compared to typical liquid media conditions have not been systematically characterized. Here we determine changes in E. coli growth rates and cell dimensions in different sized dead-end microfluidic channels using high resolution optical microscopy. We find that E. coli adapt to the confined channel environment by becoming narrower and longer compared to the same strain grown in liquidmore » culture. Cell dimensions decrease as the channel length increases and width decreases. These changes are accompanied by increases in doubling times in agreement with the universal growth law. In channels 100 μm and longer, cell doublings can completely stop as a result of frictional forces that oppose cell elongation. Before complete cessation of elongation, mechanical stresses lead to substantial deformation of cells and changes in their morphology. Lastly, our work shows that mechanical forces rather than nutrient limitation are the main growth limiting factor for bacterial growth in long and narrow channels.« less

Emergence and patterning of the five cell types of the Zea mays anther locule

PubMed Central

Kelliher, Timothy; Walbot, Virginia

2011-01-01

One fundamental difference between plants and animals is the existence of a germ-line in animals and its absence in plants. In flowering plants the sexual organs (stamens and carpels) are composed almost entirely of somatic cells, a small subset of which switch to meiosis, however, the mechanism of meiotic cell fate acquisition is a long-standing botanical mystery. In the maize (Zea mays) anther microsporangium the somatic tissues consist of four concentric cell layers which surround and support reproductive cells as they progress through meiosis and pollen maturation. Male sterility, defined as the absence of viable pollen, is a common phenotype in flowering plants, and many male sterile mutants have defects in somatic and reproductive cell fate acquisition. However, without a robust model of anther cell fate acquisition based on careful observation of wild type anther ontogeny, interpretation of cell fate mutants is limited. To address this, the pattern of cell proliferation, expansion, and differentiation was tracked in three dimensions over thirty days of wild type (W23) anther development, using anthers stained with propidium iodide (PI) and/or 5-ethynyl-2′-deoxyuridine (EdU) (S-phase label) and imaged by confocal microscopy. The pervading lineage model of anther development claims that new cell layers are generated by coordinated, oriented cell divisions in transient precursor cell types. In reconstructing anther cell division patterns, however, we can only confirm this for the origin of the middle layer (ml) and tapetum, while young anther development appears more complex. We find that each anther cell type undergoes a burst of cell division after specification with a characteristic pattern of both cell expansion and division. Comparisons between two inbreds lines and between ab- and adaxial anther florets indicated near identity: anther development is highly canalized and synchronized. Three classical models of plant organ development are tested and ruled out; however, local clustering of developmental events was identified for several processes, including the first evidence for a direct relationship between the development of ml and tapetal cells. We speculate that small groups of ml and tapetum cells function as a developmental unit dedicated to the development of a single pollen grain. PMID:21070762

Optical Antenna-Based Fluorescence Correlation Spectroscopy to Probe the Nanoscale Dynamics of Biological Membranes.

PubMed

Winkler, Pamina M; Regmi, Raju; Flauraud, Valentin; Brugger, Jürgen; Rigneault, Hervé; Wenger, Jérôme; García-Parajo, María F

2018-01-04

The plasma membrane of living cells is compartmentalized at multiple spatial scales ranging from the nano- to the mesoscale. This nonrandom organization is crucial for a large number of cellular functions. At the nanoscale, cell membranes organize into dynamic nanoassemblies enriched by cholesterol, sphingolipids, and certain types of proteins. Investigating these nanoassemblies known as lipid rafts is of paramount interest in fundamental cell biology. However, this goal requires simultaneous nanometer spatial precision and microsecond temporal resolution, which is beyond the reach of common microscopes. Optical antennas based on metallic nanostructures efficiently enhance and confine light into nanometer dimensions, breaching the diffraction limit of light. In this Perspective, we discuss recent progress combining optical antennas with fluorescence correlation spectroscopy (FCS) to monitor microsecond dynamics at nanoscale spatial dimensions. These new developments offer numerous opportunities to investigate lipid and protein dynamics in both mimetic and native biological membranes.

Geometrical optics approach in liquid crystal films with three-dimensional director variations.

PubMed

Panasyuk, G; Kelly, J; Gartland, E C; Allender, D W

2003-04-01

A formal geometrical optics approach (GOA) to the optics of nematic liquid crystals whose optic axis (director) varies in more than one dimension is described. The GOA is applied to the propagation of light through liquid crystal films whose director varies in three spatial dimensions. As an example, the GOA is applied to the calculation of light transmittance for the case of a liquid crystal cell which exhibits the homeotropic to multidomainlike transition (HMD cell). Properties of the GOA solution are explored, and comparison with the Jones calculus solution is also made. For variations on a smaller scale, where the Jones calculus breaks down, the GOA provides a fast, accurate method for calculating light transmittance. The results of light transmittance calculations for the HMD cell based on the director patterns provided by two methods, direct computer calculation and a previously developed simplified model, are in good agreement.

Evaluation of the impact of banking umbilical cord blood units with high cell dose for ethnically diverse patients.

PubMed

Stritesky, Gretta; Wadsworth, Kimberly; Duffy, Merry; Buck, Kelly; Dehn, Jason

2018-02-01

Umbilical cord blood units provide an important stem cell source for transplantation, particularly for patients of ethnic diversity who may not have suitably matched available, adult-unrelated donors. However, with the cost of cord blood unit acquisition from public banks significantly higher than that for adult-unrelated donors, attention is focused on decreasing cost yet still providing cord blood units to patients in need. Historical practices of banking units with low total nucleated cell counts, including units with approximately 90 × 10 7 total nucleated cells, indicates that most banked cord blood units have much lower total nucleated cell counts than are required for transplant. The objective of this study was to determine the impact on the ability to identify suitable cord blood units for transplantation if the minimum total nucleated cell count for banking were increased from 90 × 10 7 to 124 or 149 × 10 7 . We analyzed ethnically diverse patients (median age, 3 years) who underwent transplantation of a single cord blood unit in 2005 to 2016. A cord blood unit search was evaluated to identify units with equal or greater human leukocyte antigen matching and a greater total nucleated cell count than that of the transplanted cord blood unit (the replacement cord blood unit). If the minimum total nucleated cell count for banking increased to 124 or 149 × 10 7 , then from 75 to 80% of patients would still have at least 1 replacement cord blood unit in the current (2016) cord blood unit inventory. The best replacement cord blood units were often found among cords with the same ethnic background as the patient. The current data suggest that, if the minimum total nucleated cell count were increased for banking, then it would likely lead to an inventory of more desirable cord blood units while having minimal impact on the identification of suitable cord blood units for transplantation. © 2017 AABB.

Child poverty and regional disparities in Turkey.

PubMed

Eryurt, Mehmet Ali; Koç, Ismet

2013-01-01

The United Nations Children's Fund (UNICEF) defines child poverty as the inability of the child to realize their existing potential due to their inability to access resources across different dimensions of life (income, health, nutrition, education, environment, etc.). On the basis of this definition, an attempt has been made in this study to put forth the disadvantaged positions children have in different dimensions of their lives, specifically by taking regional disparities into account. As the data source, the Turkey Demographic and Health Survey 2008 is used, a survey that consists of detailed information about the different dimensions of child poverty. In this study, in order to measure poverty in four different dimensions (education and work, health and nutrition, family environment, and domestic environment), a total of 25 variables were used and descriptive and multivariate analyses were made in order to highlight the regional disparities in child poverty. Principle components analysis conducted through the use of a deficit approach reveals that the variables closely related with education and health and nutrition were the critical dimensions behind child poverty in Turkey. The results of this study indicate that 22.4% of children in Turkey are poor when various dimensions of life are taken into account; the region with the highest child poverty is Central East Anatolia, at 34.9%, while the region with the lowest rate is East Marmara, at 15.6%.

Optical detection system for MEMS-type pressure sensor

NASA Astrophysics Data System (ADS)

Sareło, K.; Górecka-Drzazga, A.; Dziuban, J. A.

2015-07-01

In this paper a special optical detection system designed for a MEMS-type (micro-electro-mechanical system) silicon pressure sensor is presented. The main part of the optical system—a detection unit with a perforated membrane—is bonded to the silicon sensor, and placed in a measuring system. An external light source illuminates the membrane of the pressure sensor. Owing to the light reflected from the deflected membrane sensor, the optical pattern consisting of light points is visible, and pressure can be estimated. The optical detection unit (20   ×   20   ×   20.4 mm3) is fabricated using microengineering techniques. Its dimensions are adjusted to the dimensions of the pressure sensor (5   ×   5 mm2 silicon membrane). Preliminary tests of the optical detection unit integrated with the silicon pressure sensor are carried out. For the membrane sensor from 15 to 60 µm thick, a repeatable detection of the differential pressure in the range of 0 to 280 kPa is achieved. The presented optical microsystem is especially suitable for the pressure measurements in a high radiation environment.

The fourth dimension of life: fractal geometry and allometric scaling of organisms.

PubMed

West, G B; Brown, J H; Enquist, B J

1999-06-04

Fractal-like networks effectively endow life with an additional fourth spatial dimension. This is the origin of quarter-power scaling that is so pervasive in biology. Organisms have evolved hierarchical branching networks that terminate in size-invariant units, such as capillaries, leaves, mitochondria, and oxidase molecules. Natural selection has tended to maximize both metabolic capacity, by maximizing the scaling of exchange surface areas, and internal efficiency, by minimizing the scaling of transport distances and times. These design principles are independent of detailed dynamics and explicit models and should apply to virtually all organisms.

Islamic Concept of Just War and Laws of Armed Conflict (LoAC): A Contemplative Perspective towards Better Understanding of Jihad and Humanistic Dimensions of Islam

DTIC Science & Technology

2013-04-18

Dimensions of Islam 5a. CONTRACT NUMBER N/A 5b. GRANT NUMBER N/A 5c. PROGRAM ELEMENT NUMBER N/A 6. AUTHOR( S ) Hayat, Amer, Major 5d. PROJECT...NUMBER N/A 5e. TASK NUMBER N/A 5f. WORK UNIT NUMBER N/A 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) USMC Command and Staff College...Marine Corps University 2076 South Street Quantico, VA 22134-5068 8. PERFORMING ORGANIZATION REPORT NUMBER N/A 9. SPONSORING/MONITORING AGENCY NAME( S

Considering the significance of ancestry through the prism of mixed-race identity.

PubMed

Tashiro, Cathy J

2002-12-01

People of mixed ancestry promise to be a significant percentage of the population of the United States in the 21st century. This article describes a qualitative study of 20 older mixed-race adults of African-American-white and Asian-American-white ancestries and focuses on how the participants construct identity. Using grounded theory methodology, racial identity did not emerge as a singular, distinct entity in this study, and five dimensions of racial identity were observed. Significant differences in patterns of identity dimensions were noted for the two mixed groups. Implications for nursing practice are discussed.

An "ASYMPTOTIC FRACTAL" Approach to the Morphology of Malignant Cell Nuclei

NASA Astrophysics Data System (ADS)

Landini, Gabriel; Rippin, John W.

To investigate quantitatively nuclear membrane irregularity, 672 nuclei from 10 cases of oral cancer (squamous cell carcinoma) and normal cells from oral mucosa were studied in transmission electron micrographs. The nuclei were photographed at ×1400 magnification and transferred to computer memory (1 pixel = 35 nm). The perimeter of the profiles was analysed using the "yardstick method" of fractal dimension estimation, and the log-log plot of ruler size vs. boundary length demonstrated that there exists a significant effect of resolution on length measurement. However, this effect seems to disappear at higher resolutions. As this observation is compatible with the concept of asymptotic fractal, we estimated the parameters c, L and Bm from the asymptotic fractal formula Br = Bm {1 + (r / L)c}-1 , where Br is the boundary length measured with a ruler of size r, Bm is the maximum boundary for r → 0, L is a constant, and c = asymptotic fractal dimension minus topological dimension (D - Dt) for r → ∞. Analyses of variance showed c to be significantly higher in the normal than malignant cases (P < 0.001), but log(L) and Bm to be significantly higher in the malignant cases (P < 0.001). A multivariate linear discrimination analysis on c, log(L) and Bm re-classified 76.6% of the cells correctly (84.8% of the normal and 67.5% of the tumor). Furthermore, this shows that asymptotic fractal analysis applied to nuclear profiles has great potential for shape quantification in diagnosis of oral cancer.

Cell electrospinning: a novel tool for functionalising fibres, scaffolds and membranes with living cells and other advanced materials for regenerative biology and medicine.

PubMed

Jayasinghe, Suwan N

2013-04-21

Recent years have seen interest in approaches for directly generating fibers and scaffolds following a rising trend for their exploration in the health sciences. In this review the author wishes to briefly highlight the many approaches explored to date for generating such structures, while underlining their advantages and disadvantages, and their contribution in particular to the biomedical sciences. Such structures have been demonstrated as having implications in both the laboratory and the clinic, as they mimic the native extra cellular matrix. Interestingly the only materials investigated until very recently for generating fibrous architectures employed either natural or synthetic polymers with or without the addition of functional molecule(s). Arguably although such constructs have been demonstrated to have many applications, they lack the one unit most important for carrying out the ability to directly reconstruct a three-dimensional functional tissue, namely living cells. Therefore recent findings have demonstrated the ability to directly form cell-laden fibers and scaffolds in useful quantities from which functional three-dimensional living tissues can be conceived. These recent developments have far-reaching ramifications to many areas of research and development, a few of which range from tissue engineering and regenerative medicine, a novel approach to analyzing cell behavior and function in real time in three-dimensions, to the advanced controlled and targeted delivery of experimental and/or medical cells and/or genes for localized treatment. At present these developments have passed all in vitro and in vivo mouse model based challenge trials and are now spearheading their journey towards initiating human clinical trials.

Development of an ATP assay for rapid onboard testing to detect living microorganisms in ballast water

NASA Astrophysics Data System (ADS)

Hyun, Bonggil; Cha, Hyung-Gon; Lee, Nayoung; Yum, Seungshic; Baek, Seung Ho; Shin, Kyoungsoon

2018-03-01

Ballast water is a principal pathway for the introduction of pathogens and non-indigenous species to ports worldwide. The International Maritime Organization (IMO) and the United States Coast Guard (USCG) have adopted ballast water management regulations that require, e.g., the installation of shipboard ballast water management systems (BWMS). Rapid and simple analytical methods are needed to monitor whether ballast water disinfection ensures compliance with the discharge standards. In this study laboratory and full scale land-based testing was used to investigate the suitability of an adenosine triphosphate (ATP) assay for quantifying living organisms (≥ 10 and < 50 μm minimum dimension) in ballast water. In laboratory experiments the ATP assay was highly sensitive, with a detection limit of < 5 cells 0.1 mL- 1. Diatom species (Chaetoceros simplex and Skeletonema costatum) had low ATP concentrations compared with dinoflagellate, Raphidophyceae, and Chrysophyceae species. This was because of differences in cell volume, as the ATP concentration increased exponentially with increasing cell volume. Using a regression model between ATP concentration and cell volume, an estimated the pass and fail ATP concentration in this study (788-98,610 pg mL- 1) was developed for the discharge of ballast water. In land-based testing the ATP assay also showed a good correlation with the presence of living natural plankton cells in control samples, but the ATP concentration (137 pg mL- 1) was much lower than the ATP guideline. The low ATP concentration in natural plankton cells may reflect a decline in their biological activity because of extended exposure to dark conditions. Although our results need further validation, the ATP assay is a suitable tool for monitoring compliance of ballast water treatment.

Topological quantization in units of the fine structure constant.

PubMed

Maciejko, Joseph; Qi, Xiao-Liang; Drew, H Dennis; Zhang, Shou-Cheng

2010-10-15

Fundamental topological phenomena in condensed matter physics are associated with a quantized electromagnetic response in units of fundamental constants. Recently, it has been predicted theoretically that the time-reversal invariant topological insulator in three dimensions exhibits a topological magnetoelectric effect quantized in units of the fine structure constant α=e²/ℏc. In this Letter, we propose an optical experiment to directly measure this topological quantization phenomenon, independent of material details. Our proposal also provides a way to measure the half-quantized Hall conductances on the two surfaces of the topological insulator independently of each other.

Geographic deaggregation of seismic hazard in the United States

USGS Publications Warehouse

Harmsen, S.; Frankel, A.

2001-01-01

The seismic hazard calculations for the 1996 national seismic hazard maps have been geographically deaggregated to assist in the understanding of the relative contributions of sources. These deaggregations are exhibited as maps with vertical bars whose heights are proportional to the contribution that each geographical cell makes to the ground-motion exceedance hazard. Bar colors correspond to average source magnitudes. We also extend the deaggregation analysis reported in Harmsen et al. (1999) to the western conterminous United States. In contrast to the central and eastern United States (CEUS); the influence of specific faults or characteristic events can be clearly identified. Geographic deaggregation for 0.2-sec and 1.0-sec pseudo spectral acceleration (SA) is performed for 10% probability of exceedance (PE) in 50 yr (475-yr mean return period) and 2% PE in 50 yr (2475-yr mean return period) for four western U.S. cities, Los Angeles, Salt Lake City, San Francisco, and Seattle, and for three central and eastern U.S. cities, Atlanta, Boston, and Saint Louis. In general, as the PE is lowered, the sources of hazard closer to the site dominate. Larger, more distant earthquakes contribute more significantly to hazard for 1.0-sec SA than for 0.2-sec SA. Additional maps of geographically deaggregated seismic hazard are available on the Internet for 120 cities in the conterminous United States (http://geohazards. cr.usgs.gov/eq/) for 1-sec SA and for 0.2-sec SA with a 2% PE in 50 yr. Examination of these maps of hazard contributions enables the investigator to determine the distance and azimuth to predominant sources, and their magnitudes. This information can be used to generate scenario earthquakes and corresponding time histories for seismic design and retrofit. Where fault density is lower than deaggregation cell dimensions, we can identify specific faults that contribute significantly to the seismic hazard at a given site. Detailed fault information enables investigators to include rupture information such as source directivity, radiation pattern, and basin-edge effects into their scenario earthquakes used in engineering analyses.

Nanotopography guides and directs cell migration in amoeboid and epithelial cells

NASA Astrophysics Data System (ADS)

Lee, Rachel; Das, Satarupa; Hourwitz, Matthew; Sun, Xiaoyu; Parent, Carole; Fourkas, John; Losert, Wolfgang

Cell migration plays a critical role in development, angiogenesis, immune response, wound healing, and cancer metastasis. In many cases, cells also move in the context of a matrix of collagen fibers, and the alignment of these fibers can both affect the migration phenotype and guide cells. Here we show that both fast and slow migrating cells - amoeboid HL-60 and epithelial MCF10A - are affected in similar ways by micro/nanostructures with dimensions similar to those of collagen fibers. Cell alignment enhances the efficiency of migration by increasing directional persistence.

Cell Culture in Microgravity: Opening the Door to Space Cell Biology

NASA Technical Reports Server (NTRS)

Pellis, Neal R.; Dawson, David L. (Technical Monitor)

1999-01-01

Adaptational response of human cell populations to microgravity is investigated using simulation, short-term Shuttle experiments, and long-term microgravity. Simulation consists of a clinostatically-rotated cell culture system. The system is a horizontally-rotated cylinder completely filled with culture medium. Low speed rotation results in continuous-fall of the cells through the fluid medium. In this setting, cells: 1) aggregate, 2) propagate in three dimensions, 3) synthesize matrix, 4) differentiate, and 5) form sinusoids that facilitate mass transfer. Space cell culture is conducted in flight bioreactors and in static incubators. Cells grown in microgravity are: bovine cartilage, promyelocytic leukemia, kidney proximal tubule cells, adrenal medulla, breast and colon cancer, and endothelium. Cells were cultured in space to test specific hypotheses. Cartilage cells were used to determine structural differences in cartilage grown in space compared to ground-based bioreactors. Results from a 130-day experiment on Mir revealed that cartilage grown in space was substantially more compressible due to insufficient glycosaminoglycan in the matrix. Interestingly, earth-grown cartilage conformed better to the dimensions of the scaffolding material, while the Mir specimens were spherical. The other cell populations are currently being analyzed for cell surface properties, gene expression, and differentiation. Results suggest that some cells spontaneously differentiate in microgravity. Additionally, vast changes in gene expression may occur in response to microgravity. In conclusion, the transition to microgravity may constitute a physical perturbation in cells resulting in unique gene expressions, the consequences of which may be useful in tissue engineering, disease modeling, and space cell biology.

Sociocultural dimensions of supply and demand for natural aggregate; examples from the Mid-Atlantic region, United States

USGS Publications Warehouse

Robinson, Gilpin R.; Brown, William M.

2002-01-01

The United States uses large quantities of natural aggregate to build and maintain a continuously expanding infrastructure. In recent years, per capita demand for aggregate in the United States has grown to about 9.7 metric tons (10.7 tons) per person per year. Over the next 25 years, the aggregate industry expects to mine quantities equivalent to all aggregate mined in the United States over the past 100 years. The issues surrounding supply and demand for aggregate in the mid-Atlantic states of Maryland, Pennsylvania, Virginia, and West Virginia illustrate competing requirements for industrial minerals and many simultaneous social and environmental objectives.

77 FR 16165 - United States Savings Bonds and Notes; Payments

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-20

... security by imprinting the word ``PAID'' on its face and entering the amount and date of the actual payment... imprint of a payment stamp. The stamp may not exceed 1\\1/8\\ inches in any dimension and must include the...

A framework for modeling uncertainty in regional climate change

EPA Science Inventory

In this study, we present a new modeling framework and a large ensemble of climate projections to investigate the uncertainty in regional climate change over the United States associated with four dimensions of uncertainty. The sources of uncertainty considered in this framework ...

Help Wanted: More Cosmopolitan Managers.

ERIC Educational Resources Information Center

Hayden, Rose L.

The government role in internationalizing business education in the United States is minimal for several reasons: the limited federal role in public education curriculum, limited government-industry collaboration at state and local levels, little effort to standardize the international dimension of college business administration programs, and…

Thermal Hotspots in CPU Die and It's Future Architecture

NASA Astrophysics Data System (ADS)

Wang, Jian; Hu, Fu-Yuan

Owing to the increasing core frequency and chip integration and the limited die dimension, the power densities in CPU chip have been increasing fastly. The high temperature on chip resulted by power densities threats the processor's performance and chip's reliability. This paper analyzed the thermal hotspots in die and their properties. A new architecture of function units in die - - hot units distributed architecture is suggested to cope with the problems of high power densities for future processor chip.

Numerical simulation on dimension decrease for annular casing of one centrifugal boiler circulation pump

NASA Astrophysics Data System (ADS)

Fan, Y. Z.; Zuo, Z. G.; Liu, S. H.; Wu, Y. L.; Sha, Y. J.

2012-11-01

Primary formulation derivation indicates that the dimension of one existing centrifugal boiler circulation pump casing is too large. As great manufacture cost can be saved by dimension decrease, a numerical simulation research is developed in this paper on dimension decrease for annular casing of this pump with a specific speed equaling to 189, which aims at finding an appropriately smaller dimension of the casing while hydraulic performance and strength performance will hardly be changed according to the requirements of the cooperative company. The research object is one existing centrifugal pump with a diffuser and a semi-spherical annular casing, working as the boiler circulation pump for (ultra) supercritical units in power plants. Dimension decrease, the modification method, is achieved by decreasing the existing casing's internal radius (marked as "Ri0") while keeping the wall thickness. The research analysis is based on primary formulation derivation, CFD (Computational Fluid Dynamics) simulation and FEM (Finite Element Method) simulation. Primary formulation derivation estimates that a design casing's internal radius should be less than 0.75 Ri0. CFD analysis indicates that smaller casing with 0.75 Ri0 has a worse hydraulic performance when working at large flow rates and a better hydraulic performance when working at small flow rates. In consideration of hydraulic performance and dimension decrease, an appropriate casing's internal radius is determined, which equals to 0.875 Ri0. FEM analysis then confirms that modified pump casing has nearly the same strength performance as the existing pump casing. It is concluded that dimension decrease can be an economical method as well as a practical method for large pumps in engineering fields.

Determining the Molecular Growth Mechanisms of Protein Crystal faces by Atomic Force Microscopy

NASA Technical Reports Server (NTRS)

Li, Huayu; Nadarajah, Arunan; Pusey, Marc L.

1998-01-01

A high resolution atomic force microscopy (AFM) study had shown that the molecular packing on the tetragonal lysozyme (110) face corresponded to only one of two possible packing arrangements, suggesting that growth layers on this face were of bimolecular height (Li et al., 1998). Theoretical analyses of the packing had also indicated that growth of this face should proceed by the addition of growth units of at least tetramer size corresponding to the 43 helices in the crystal. In this study an AFM linescan technique was devised to measure the dimensions of individual growth units on protein crystal faces. The growth process of tetragonal lysozyme crystals was slowed down by employing very low supersaturations. As a result images of individual growth events on the (110) face were observed, shown by jump discontinuities in the growth step in the linescan images. The growth unit dimension in the scanned direction was obtained by suitably averaging these images. A large number of scans in two directions on the (110) face were performed and the distribution of lysozyme aggregate sizes were obtained. A variety of growth units, all of which were 43 helical lysozyme aggregates, were shown to participate in the growth process with a 43 tetramer being the minimum observed size. This technique represents a new application for AFM allowing time resolved studies of molecular process to be carried out.

Rhombicuboctahedron unit cell based scaffolds for bone regeneration: geometry optimization with a mechanobiology - driven algorithm.

PubMed

Boccaccio, Antonio; Fiorentino, Michele; Uva, Antonio E; Laghetti, Luca N; Monno, Giuseppe

2018-02-01

In a context more and more oriented towards customized medical solutions, we propose a mechanobiology-driven algorithm to determine the optimal geometry of scaffolds for bone regeneration that is the most suited to specific boundary and loading conditions. In spite of the huge number of articles investigating different unit cells for porous biomaterials, no studies are reported in the literature that optimize the geometric parameters of such unit cells based on mechanobiological criteria. Parametric finite element models of scaffolds with rhombicuboctahedron unit cell were developed and incorporated into an optimization algorithm that combines them with a computational mechanobiological model. The algorithm perturbs iteratively the geometry of the unit cell until the best scaffold geometry is identified, i.e. the geometry that allows to maximize the formation of bone. Performances of scaffolds with rhombicuboctahedron unit cell were compared with those of other scaffolds with hexahedron unit cells. We found that scaffolds with rhombicuboctahedron unit cell are particularly suited for supporting medium-low loads, while, for higher loads, scaffolds with hexahedron unit cells are preferable. The proposed algorithm can guide the orthopaedic/surgeon in the choice of the best scaffold to be implanted in a patient-specific anatomic region. Copyright © 2017 Elsevier B.V. All rights reserved.

Nurses' views of shared leadership in ICU: a case study.

PubMed

Rosengren, Kristina; Bondas, Terese; Nordholm, Lena; Nordström, Gun

2010-08-01

New management models develop; one of them is shared leadership where two nurse managers share tasks and responsibility for a unit. The overall aim of this study was to describe the view of the staff about shared leadership at an ICU in Sweden and to study if there were any differences in perceptions between staff groups. This unit had changed the management organisation from single leadership (one nurse manager) to shared leadership (two nurse managers). Sixty-four (79%) registered nurses and assistant nurses responded to a 72 item questionnaire measuring social and organisational factors at work, especially leadership and shared leadership. The results showed that staff reported positive views in relation to the dimensions 'Organisational culture', 'Social interactions', 'Work satisfaction', 'Leadership', 'Shared leadership' and 'Work motives'. Registered nurses reported more positive views than assistant nurses in relation to the dimensions: 'Organisational culture', 'Social interactions', 'Work satisfaction' and 'Leadership'. Further, females had more positive views than males on the dimension 'Social interactions'. Staff described that shared leadership positively influenced the work in terms of confidence. In conclusion, staff reported positive views of work and the model shared leadership in the investigated ICU. One implication is that nurse managers have to be conscious of different health professionals in the unit and it is important to offer a good working environment for all staff. However, more research is needed within the area of shared leadership. A future research project could be to add a qualitative research question about how work and shared leadership affects different health professionals in the day to day practice both at the managerial as well as the team level to improve health care. Copyright 2010 Elsevier Ltd. All rights reserved.

Dynamic microenvironments: the fourth dimension.

PubMed

Tibbitt, Mark W; Anseth, Kristi S

2012-11-14

The extracellular space, or cell microenvironment, choreographs cell behavior through myriad controlled signals, and aberrant cues can result in dysfunction and disease. For functional studies of human cell biology or expansion and delivery of cells for therapeutic purposes, scientists must decipher this intricate map of microenvironment biology and develop ways to mimic these functions in vitro. In this Perspective, we describe technologies for four-dimensional (4D) biology: cell-laden matrices engineered to recapitulate tissue and organ function in 3D space and over time.

An enteroendocrine cell-enteric glia connection revealed by 3D electron microscopy.

PubMed

Bohórquez, Diego V; Samsa, Leigh A; Roholt, Andrew; Medicetty, Satish; Chandra, Rashmi; Liddle, Rodger A

2014-01-01

The enteroendocrine cell is the cornerstone of gastrointestinal chemosensation. In the intestine and colon, this cell is stimulated by nutrients, tastants that elicit the perception of flavor, and bacterial by-products; and in response, the cell secretes hormones like cholecystokinin and peptide YY--both potent regulators of appetite. The development of transgenic mice with enteroendocrine cells expressing green fluorescent protein has allowed for the elucidation of the apical nutrient sensing mechanisms of the cell. However, the basal secretory aspects of the enteroendocrine cell remain largely unexplored, particularly because a complete account of the enteroendocrine cell ultrastructure does not exist. Today, the fine ultrastructure of a specific cell can be revealed in the third dimension thanks to the invention of serial block face scanning electron microscopy (SBEM). Here, we bridged confocal microscopy with SBEM to identify the enteroendocrine cell of the mouse and study its ultrastructure in the third dimension. The results demonstrated that 73.5% of the peptide-secreting vesicles in the enteroendocrine cell are contained within an axon-like basal process. We called this process a neuropod. This neuropod contains neurofilaments, which are typical structural proteins of axons. Surprisingly, the SBEM data also demonstrated that the enteroendocrine cell neuropod is escorted by enteric glia--the cells that nurture enteric neurons. We extended these structural findings into an in vitro intestinal organoid system, in which the addition of glial derived neurotrophic factors enhanced the development of neuropods in enteroendocrine cells. These findings open a new avenue of exploration in gastrointestinal chemosensation by unveiling an unforeseen physical relationship between enteric glia and enteroendocrine cells.