cssi/SciSciGPT-SciSciNet huggingface dataset:
Robust Estimation of Image Flow

Motion is a key visual cue for segmentation. A particularly difficult problem is the segmentation of objects that are camouflaged and match the background perfectly. In such situations, it is critical that the boundaries of the object be determined accurately since the outline (silhouette) will be the only visual information available for segmentation and recognition. Image flow is the velocity field in the image plane caused by the motion of the observer, objects in the scene, or apparent motion. The image flow velocity field can be used for segmentation if the motion boundaries can be accurately estimated. When an object moves against a background, the motion constraints are distorted along the boundary and the motion estimation problem is very difficult to solve. The distorted motion data would be called outliers by workers in the field of robust statistics. Recent work has been done on robust algorithms for image flow estimation and segmentation. New algorithms based on robust regression show promise in handling the difficult problems associated with discontinuities in the image flow velocity field. The results point toward better methods for handling discontinuities in other vision problems. In particular, algorithms for sensor fusion will face the task of combining information that contains outliers and discontinuities. The material presented in this paper may indicate directions for future research on sensor fusion.
Damage Symptoms and Abundance of Diuraphis noxia (Homoptera: Aphididae) for Four Wheat Cultivars at Three Irrigation Levels

In Montpellier, France, the effects of wheat cultivar and irrigation level on damage symptoms and Diuraphis noxia (Mordvilko) abundance were tested in screenhouse and field experiments. Four cultivars were used: ‘Mondur’ and ‘Arcour’, which are drought susceptible, and ‘Agathe’ and ‘Ardente’, which are drought tolerant. Previous preliminary observations had also indicated that ‘Arcour’ might be more susceptible to D. noxia than ‘Ardente’. Each cultivar was irrigated at three levels in the screenhouse (25, 50, and 75% soil saturation) and in the field (sheltered from rain, rainfall, and irrigation plus rainfall). In the screenhouse, D. noxia density increased throughout the experiment, but did not vary with cultivar. In the field, although D. noxia density increased initially, densities were much lower than in the screenhouse, perhaps because of natural enemy impact. ‘Arcour’ and ‘Agathe’ trended to have higher densities in the field than ‘Mondur’ and ‘Ardente’. Although aphid densities were lower with lowest level of irrigation in the screenhouse, irrigation level did not affect aphid density in the field. Irrigation level did not significantly affect damage symptoms in the screenhouse or field. Although cultivar did not affect leaf streaking in the screen house or field, ‘Ardente’ and ‘Agathe’ showed significantly greater leaf rolling than ‘Mondur’ and ‘Arcour’ in the screenhouse, despite lack of differences in aphid density. The results of these experiments suggest that neither irrigation nor drought tolerance directly reduce density or impact of D. noxia , and one must look at other mechanisms to explain the negative correlation between high rainfall and D. noxia abundance.
Piecewise potential vorticity inversion

Abstract The treatment of the potential vorticity (PV) distribution as a composite of individual perturbations is central to the diagnostic and conceptual utility of PV. Nonlinearity in the inversion operator for Ertel's potential vorticity renders quantitative piecewise inversion (inversion of individual portions of the potential vorticity field) ambiguous. Several methods of piecewise inversion are compared for idealized and observed potential vorticity anomalies of varying strengths. Even as the Rossby number of the balanced solutions increases well past unity, relative differences among the more plausible methods do not increase significantly near the anomaly. These relative differences are also found to be smaller than those obtained by comparing any of the methods to quasigeostrophic inversion. However, differences above and below anomalies increase with increasing Rossby number, suggesting that one cannot uniquely diagnose the interaction of large amplitude PV anomalies.
A method to reduce interference by sucrose in the detection of thiobarbituric acid-reactive substances☆

A thiobarbituric acid (TBA) reaction for measuring lipid peroxidation products was evaluated for interference by several ingredients commonly used in solutions to prepare or analyze tissue homogenates or subcellular organelles. These included sucrose (up to 100 mM final concentration in the assay medium), Tris-maleate (up to 40 mM), imidazole (up to 20 mM), inorganic phosphate (up to 10 mM), and 4- morpholinepropanesulfonic acid (up to 20 mM). When the samples were heated at 95 degrees C as recommended in some procedures, only sucrose significantly affected color development. Sucrose concentrations as low as 10 mM significantly increased absorbance at 532 nm of aqueous tetramethoxypropane (TMP) standards, and so the assay could not be applied reliably to tissue samples prepared in sucrose. Sucrose interference was only partially reduced by subsequent organic extraction (n-butanol plus pyridine), with measured absorbances remaining significantly greater (50-100%) than sucrose-free controls at sucrose concentrations of 20 mM or more. Modifying the assay to include sucrose in blanks and TMP standards failed to adequately correct for interference when the absorbance of unextracted (aqueous) solutions was measured. Further modification by adding sucrose to blanks and TMP standards, followed by butanol-pyridine extraction, gave standard curves that were linear, through the origin, and had slopes equivalent to those of sucrose-free standards. This modification enabled almost complete recovery (average 2% error) of known amounts of TMP added to aliquots of tissue homogenates containing amounts of sucrose that otherwise significantly interfered. Also, with the modified method the content of TBA-reactive substances in tissues homogenized in sucrose was found to be not significantly different from that measured in tissues homogenized in a noninterfering substance, KCl.
Volatility, price resolution, and the effectiveness of price limits

Following the market crash in 1987, there has been increased interest in the usefulness of price limits as well as other forms of market controls. The purpose of this research is to investigate price limits and the empirical behavior of futures prices for a selected group of commodities around price limits. For the group of commodities examined in this research, the empirical results show that for the time periods analyzed, in general: 1 The period of time immediately preceding limit moves is characterized by major changes in the direction of the limit price while following the limit move; prices tend to either stabilize or reverse directions, thus suggesting that price limits may provide a cooling-off period for the market. 2 Price limits also appear to be accompanied by substantial reductions in volatility. This attenuation of volatility in the post-limit period and the maintenance of volume in the post-limit period tend to suggest that liquidity may not be severely impaired by the limit move process.
Ca2+ flux in retinal rod and cone outer segments: differences in Ca2+ selectivity of the cGMP-gated ion channels and Ca2+ clearance rates.

Abstract In intact rod and cone photoreceptors of various vertebrate species, depolarization in the dark to ≥+20 mV specifically activates the cGMP-dependent conductance in the outer segment. This activation reflects a voltage-dependent decrease in cytoplasmic Ca 2+ and the consequent activation of a Ca 2+ -dependent guanylyl cyclase. The conductance activation in cones in much faster in time course and larger in extent than that in rods. Simulations of the experimental results suggest that these differences arise from differences in Ca 2+ homeostasis in the rod and cone outer segments. Direct measurements demonstrate that, indeed, the Ca 2+ permeability of the cGMP-gated channels is higher in cones than in rods. Also, as was previously known, the rate of Ca 2+ efflux from cone outer segments is higher than that in rods. Therefore, a given light-dependent change in membrane current should cause a much larger and much quicker decrease in Ca 2+ concentration in cones than in rods. The activity of every Ca 2+ -dependent biochemical event in the outer segment should, hence, change more rapidly and to a larger extent in cones than in rods. We propose that these kinetic and stoichiometric differences in the function of Ca 2+ -dependent processes is important in explaining the difference in the transduction signal of the two receptor types.
Disassembly of actin networks by filament severing

The disassembly of actin networks by filament severing is studied by simulation of a model in which the actin filaments are crosslinked in a periodic network and begin to sever as soon as they are created at the cell membrane. The actin network is defined as the set of all sites which have a connecting path leading to the membrane. An extension of this model including annealing effects, corresponding to restoration of links between nodes, is studied as well. The simulations show that in the presence of only severing, the network density drops abruptly at a critical distance from the network, which is inversely proportional to the severing rate. This result is explained by a mean-field theory based on a layer-by-layer approach in which the average size of an in-layer connected cluster is used to calculate the probability of a given site having a connected path to the membrane, via the next layer in. Inclusion of annealing effects leads to a broadening of the attached portion of the network. At a critical value of the annealing rate, the network density develops a component that does not decay away from the membrane.
Commentary: Hypovitaminosis D in patients undergoing kyphoplasty is associated with increased risk of subsequent vertebral fractures.

COMMENTARY ON Zafeiris CP, Lyritis GP, Papaioannou NA, et al. Hypovitaminosis D as a risk factor of subsequent vertebral fractures after kyphoplasty. Spine J 2012;12:304–12 ( in this issue ).
Quantitative analysis of sugars in wood hydrolyzates with 1H NMR during the autohydrolysis of hardwoods

The focus of this work was to determine the utility of (1)H NMR spectroscopy in the quantification of sugars resulting from the solubilization of hemicelluloses during the autohydrolysis of hardwoods and the use of this technique to evaluate the kinetics of this process over a range of temperatures and times. Yields of residual xylan, xylooligomers, xylose, glucose, and the degraded products of sugars, i.e., furfural and HMF (5-hydroxymethyl furfural), were determined. The monosaccharide and oligomer contents were quantified with a recently developed high resolution (1)H NMR spectroscopic analysis. This method provided precise measurement of the residual xylan and cellulose remaining in the extracted wood samples and xylose and glucose in the hydrolyzates. NMR was found to exhibit good repeatability and provided carbohydrate compositional results comparable to published methods for sugar maple and aspen woods.
Comments on Sydney Shoemaker’s Physical Realization

This paper interprets and criticizes some of the views presented in Sydney Shoemaker’s book, Physical Realization (Oxford University Press, 2007), on the topic of how mental properties are realized by physical properties, given that, on his view, human persons are not even token-identical with human bodies.
Reduction of processing losses in on-line or off-line acquisition of random counts at high rates

Abstract Experiments in which random events are counted at rapidly varying event rates are subject to deadtime errors which cannot be readily corrected for. Such losses can be minimized, however, through the use of a fast prescaler or distributor. The deadtime loss for prescalers and distributors is calculated here, under very general assumptions, and a practical prescaler is described.
Direct Numerical Simulation of Turbulent Flow Separation from a Wall-Mounted Hump

A high-order-accurate numerical method for solving the incompressible Navier‐Stokes equations in general orthogonal coordinates is presented. The method is applied to a test case of the NASA Langley Computational Fluid Dynamics Validation Workshop 2004, a turbulent flow over a wall-mounted hump geometry. Results of direct numerical simulations (DNS) for the unforced flow as well as for a case with steady suction are presented and compared to the available experimental data. The DNS predictions are shown to agree well with the experiments, except in the vicinity of the experimental reattachment locations. The simulations predict slightly longer recirculation regions for both the unforced and the controlled case. The results presented in this work suggest that, with the rapidly increasing computational resources of modern supercomputers such as the Cray X1, DNS is becoming a viable alternative to the use of turbulence models for investigating complex turbulent flows at moderately high Reynolds numbers.
Structures, Realities, and Blind Spots

In discussing the exchange between Caws and Hanson (AA, Vol. 78, 1976) the nature of the theory and reality that anthropologists must consider in dealing with social and cultural phenomena is examined. There is no objective structure in the phenomena we study, our constructs always being colored by changing conditions. The assumption of an unchanging human nature has long been an obstacle to progress in the anthropological enterprise. [semantics, language, models, structure, anthropological theory]
Generational Status and Academic Achiev Ement among Latino High School Students: Evaluating the Segmented Assimilation Theory:

In this study, the author evaluates some of the key assertions of the segmented assimilation theory by examining the generational pattern of achievement among Latino high school students. Segmented assimilation theory posits that the outcomes of immigrants will not necessarily improve monotonically across generations, especially in disadvantaged contexts, and that maintaining familial and ethnic ties can have a protective effect on immigrant students. The author tests these ideas by examining variation in the generational pattern of achievement in low-income schools among Latino high school students. The author finds that changes in achievement across generations generally follow a pattern of classical assimilation with small, though not statistically significant, improvements in achievement from the first to the second generation and from the second to the third generation in both poor and nonpoor schools. Contrary to hypotheses derived from segmented assimilation theory, the author finds no evidence of ...
Comparative study of the genotoxic properties of Eastern and Western U.S. shale oils, crude petroleum, and coal-derived oil.

Abstract A multiple bioassay approach was used to characterize and compare the genotoxicities of an Eastern U.S. (Kentucky) shale oil with the genotoxicities of Western U.S. shale oil, petroleum crude oil, and a coal-derived fuel oil. While the coal-derived oil was mutagenic in the Salmonella/microsome mutagenicity (Ames) assay, the shale oils had negligible to weak mutagenicity, and petroleum crude oil was not mutagenic. All the samples were also tested in the following mammalian test systems: an in vitro sister-chromatid exchange (SCE) assay in human lymphocytes and in vivo tests for induction of sperm abnormalities, micronuclei, and SCE in bone marrow of mice. Slight but statistically significant increases ( P Eastern and Western shale oil > petroleum crude oil.
Coronary hemodynamics during reperfusion following acute coronary ligation in dogs.

Abstract The coronary hemodynamic effects of re-establishing blood flow to ischemic myocardium and the regional distribution of myocardial flow during reperfusion were studied in anesthetized open-chest dogs. A large portion of the left ventricular wall was rendered ischemic by occlusion of the left anterior descending coronary artery for 2 hours. During reperfusion of the LAD, coronary resistance in the reperfused vasculature increased progressively for the first 3 hours, while resistance in the intact LC vasculature was unchanged. Minimal resistances in the reperfused vascular bed, calculated from mean aortic pressure and peak coronary reactive hyperemic blood flow following a 90 sec. LAD occlusion, were elevated significantly during reperfusion. The increased minimal resistance values, which reflect the passive physical component of resistance, indicate structural changes in the reperfused vascular bed which were evident shortly after the initiation of reperfusion and persisted throughout the experimental period. Coronary resistances (R H ) in the reperfused (LAD) and intact (LC) vasculatures during the reactive hyperemia following 10 sec. coronary occlusions were evaluated. During reperfusion, R H in the reperfused vasculature increased progressively while R H in the intact bed was unchanged. The marked increase in R H in the LAD indicates that the reactive hyperemic flow response to a consistent period of coronary occlusion progressively diminished, and reflects a gradual reduction in the vasodilatory potential of the reperfused coronary circulation. The regional distribution of myocardial blood flow following 5 minutes, 2 hours, and 4 hours of reperfusion was measured with multiple injections of radioactive microspheres. These measurements demonstrated a progressive reduction of blood flow to the reperfused myocardium with no significant change in flow to the control myocardium. In contrast to the uniform transmural distribution of flow in the normal myocardium, the reperfused region showed a distinctly nonuniform distribution of flow after 2 hours and 4 hours of reperfusion, with more severe reduction of flow to the endocardial layer. These studies would suggest that rechannelling blood flow distal to an acute coronary occlusion in human subjects might not in itself be capable of reversing the myocardial injury. It is hoped that additional therapeutic measures might be applied to salvage the injured myocardium.
Contour-Mode Ring-Shaped AlN Microresonator on Si and Feasibility of Its Application in Series-Resonant Converter

Microelectromechanical systems (MEMS) resonators on Si have the potential to replace the discrete passive components in a power converter. The main intention of this paper is to present a ring-shaped aluminum nitride (AlN) piezoelectric microresonator that can be used as an energy-transferring device to replace inductors/capacitors in low-power resonant converters for biomedical applications. Finite-element simulation results have been provided, showing the mode of vibration at resonant frequency. The zero-voltage switching (ZVS) condition for a series-resonant converter incorporating the proposed MEMS resonator has been presented analytically and verified through experiment. This ZVS condition can be found in terms of the equivalent circuit parameters of the resonator. To the knowledge of the authors, ZVS analysis based on the equivalent electrical circuit model of the thin piezoelectric film resonators has not yet been reported in the literature. A CMOS-compatible fabrication process has been proposed and implemented. In addition, the fabricated devices have been characterized and experimental results are included in this paper. The first contour-mode AlN MEMS resonator with moderately low resonant frequency and motional resistance is reported in this paper with measured resonant frequency and motional resistance of 87.28 MHz and 36.728 Ω, respectively.
Metabolic rate and evaporative water loss in the least seed-snipe, Thinocorus rumicivorus

Abstract 1. 1. Metabolic rate and evaporative water loss (EWL) were determined in Thinororus rumicivorus, a xerophilous shorebird, over an ambient temperature range of 20–44°C. 2. 2. Standard metabolism was 38% lower than predicted for a 55 g, non-passerine bird. 3. 3. The thermoneutral zone extended from 33 to 38°C. 4. 4. EWL was maximally efficient at 42°C, with dissipation of 134% of total heat produced. 5. 5. The low metabolic rate of T. rumicivorus is adaptive for existence in arid environments, but it must drink or eat succulent vegetation to maintain water balance.
ELECTRON IMPACT IONIZATION OF ATOMIC NITROGEN

The total cross sections for the ionization of atomic nitrogen by electron impact have been measured between 25 and 750 eV using a modulated molecular beam technique. The neutral beam source was a pulsed dc discharge which dissociated about 20% of the molecules. The number of ions formed in a region defined by the intersection of an electron beam and the modulated molecular beam was compared with the number of ions formed when the neutral beam was partially dissociated. All ions were collected, including those energetic ones formed in the dissociative ionization of molecular nitrogen. The degree of dissociation was measured with a mass spectrometer. From the data, the ratios of the atomic to the molecular ionization cross sections were obtained. The absolute atomic values were calculated by multiplying these ratios by the molecular ionization cross sections measured by Tate and Smith. The atomic cross sections are lower than those calculated by Seaton.
Conforming versus non‐conforming boundary elements in three‐dimensional elastostatics

A critical comparison of two basic formulations in three-dimensional elastostatics, using conforming and nonconforming boundary elements, is presented. The basic structure of the boundary element method is developed. The peculiarities that both types of boundary elements present in relation to the numerical implementation are discussed. Through selected examples, key issues such as the computational advantages and disadvantages of both formulations, mesh discretization and accuracy questions, and optimal location of the collocation nodes in the case of nonconforming elements are addressed. It is shown that conforming elements are able to produce more accurate results than nonconforming ones, with substantial economy in the final size of the system equations.
Generalized hypergeometric functions: product identities and weighted norm inequalities

We describe a method of obtaining weighted norm inequalities for generalized hypergeometric functions. This method is based upon our recent convolution theorem and some classical hypergeometric identities. In particular, it is shown that some product identities involving the divergent hypergeometric series lead to the convergent hypergeometric inequalities. A number of the new weighted norm inequalities for the Gaussian hypergeometric function, confluent hypergeometric function, and other generalized hypergeometric functions are presented.
Estimating discharge in rivers using remotely sensed hydraulic information

Abstract A methodology to estimate in-bank river discharge exclusively from remotely sensed hydraulic data is developed. Water-surface width and maximum channel width measured from 26 aerial and digital orthophotos of 17 single channel rivers and 41 SAR images of three braided rivers were coupled with channel slope data obtained from topographic maps to estimate the discharge. The standard error of the discharge estimates were within a factor of 1.5–2 (50–100%) of the observed, with the mean estimate accuracy within 10%. This level of accuracy was achieved using calibration functions developed from observed discharge. The calibration functions use reach specific geomorphic variables, the maximum channel width and the channel slope, to predict a correction factor. The calibration functions are related to channel type. Surface velocity and width information, obtained from a single C-band image obtained by the Jet Propulsion Laboratory's (JPL's) AirSAR was also used to estimate discharge for a reach of the Missouri River. Without using a calibration function, the estimate accuracy was +72% of the observed discharge, which is within the expected range of uncertainty for the method. However, using the observed velocity to calibrate the initial estimate improved the estimate accuracy to within +10% of the observed. Remotely sensed discharge estimates with accuracies reported in this paper could be useful for regional or continental scale hydrologic studies, or in regions where ground-based data is lacking.
Supporting Sustainability: Teachers’ Advice Networks and Ambitious Instructional Reform

Scaling up instructional improvement remains a central challenge for school systems. While existing research suggests that teachers’ social networks play a crucial role, we know little about what dimensions of teachers’ social networks matter for sustainability. Drawing from a longitudinal study of the scale-up of mathematics reform, we use qualitative social network analysis and qualitative comparative analysis (QCA) to investigate the relationship between teachers’ social networks and sustainability. Teachers’ social networks in the first 2 years of the initiative influenced their ability to sustain reform-related instructional approaches after supports for reform were withdrawn. Social networks with combinations of strong ties, high-depth interaction, and high expertise enabled teachers to adjust instruction to new conditions while maintaining the core pedagogical approach. This research contributes to our understanding of the dynamics of sustainability and to social network theory and research.
Performance of PMS model LAS-X optical particle counter

Abstract Performance characteristics of a Particle Measuring System (PMS) Model LAS-X (0.12–7.5 μm) optical particle counter were evaluated. The effect of particle refractive index was determined theoretically by calculating response curves for 32 refractive indexes. Nonabsorbing organic particles with unknown refractive index have measurement errors that range from −50 to +20%. Unknown particles (including absorbing particles) may have measurement errors from −60 to +250%. An aerodynamic calibration of range 3 (0.12–7.5 μm) with oleic acid particles found the indicated sizes to be within ±2 channel widths of the correct aerodynamic diameters. Measurements of the effect of coincidence on measured size found errors in CMD to be less than 10% for concentrations below 10,000 cm −3 . Experimental measurements of inlet losses showed a dependence on particle size and sample flow rate with about 50% loss of 12 μm particles at a sampling rate of 5 cm 3 s −1 .
Cytokine therapy for craniosynostosis

The birth prevalence of craniosynostosis (premature suture fusion) is 300 – 500 per 1,000,000 live births. Surgical management involves the release of the synostosed suture. In many cases, however, the suturectomy site rapidly reossifies, further restricts the growing brain and alters craniofacial growth. This resynostosis requires additional surgery, which increases patient morbidity and mortality. New findings in bone biology and molecular pathways involved with suture fusion, combined with novel tissue engineering techniques, may allow the design of targeted and complementary therapies to decrease complications inherent in high-risk surgical procedures. This paper selectively reviews recent advances in i) identifying genetic mutations and the aetiopathogenesis of a number of craniosynostotic conditions; ii) cranial suture biology and molecular biochemical pathways involved in suture fusion; and iii) the design, development and application of various vehicles and tissue engineered constructs to deliver ...
Long‐Term Application of Biosolids on Apricot Production

Abstract The use and disposal of biosolids, or wastewater treatment sludge, as a fertilizer and soil amendment is becoming increasingly widespread. We evaluated the multiyear use of biosolids in apricot (Prunus armeniaca L.) production, grown on productive agricultural soils. Class A biosolids were initially applied annually at rates of 0, 1.9, 5.8, and 11.7 Mg · ha−1 (dry basis) to a 2‐year‐old apricot orchard on the USDA‐ARS research site on the eastern side of the San Joaquin Valley, CA. These application rates provided estimated rates of 0 (control), 57, 170, and 340 kg total N · ha−1 yr−1, respectively. Compared to the control treatment, the applications of biosolids significantly increased soil salinity (electrical conductivity from 1:1 soil–water extract) and total concentrations of nutrients [e.g., calcium (Ca), magnesium (Mg), sulfur (S), phosphorus (P), zinc (Zn), and copper (Cu)] after 7 years but did not increase the concentrations of selected metals [cadmium (Cd), chromium (Cr), cobalt (Co), ...
Generation and characterization of a recombinant human CCR5-specific antibody. A phage display approach for rabbit antibody humanization.

We describe the isolation of a CCR5-specific antibody, ST6, from an antibody phage display library generated from an immune rabbit. ST6 was previously shown to efficiently prevent the surface expression of CCR5 when expressed intracellularly (Steinberger, P., Andris-Widhopf, J., Buhler, B., Torbett, B. E., and Barbas, C. F., III (2000) Proc. Natl. Acad. Sci. U. S. A.97, 805–810). Because ST6 has therapeutic potential in human immunodeficiency virus, type 1 disease, its humanization was desired to minimize the potential for immunogenicity. ST6 was humanized using a phage display-based approach. Like the parental rabbit clone, the humanized version ST6/34 efficiently prevented the surface expression of CCR5. The conserved linear peptide epitope bound by these antibodies was mapped using phage display. Both ST6 as well as the humanized anti-CCR5 antibody ST6/34 were produced as complete IgG antibodies and shown to bind to cell surface CCR5.
Nitrification Inhibitor Influences on Potato

Nitrification inhibitors may reduce loss of fertilizer N from the root zone by reducing leaching and denitrification. This reduced N loss should be reflected in increased crop yields. These studies were conducted to determine if potato yield, specific gravity, or leaf N at flowering would be increased by use of nitrification inhibitors. Nitrification inhibitors dicyandiamide (DCD) and 2-chloro-6-(trichloromethyl)- pyridine (nitrapyrin) were evaluated in five studies on potato (Solanum tuberosum L- cv- Atlantic) in Northeast Morida on an Arenic Ochraqualf, a Grossarenic Paleudult, and a Grossarenic Paleaquult [...]
Ganciclovir-resistant cytomegalovirus clinical isolates: mode of resistance to ganciclovir.

Cytomegalovirus strains with reduced in vitro susceptibilities to ganciclovir have been recovered from patients who failed long-term ganciclovir therapy. The ganciclovir-resistant clinical isolates in this study were unable to induce ganciclovir phosphorylation in virus-infected cells. The viral DNA polymerase function appeared unaltered in one genetically pure ganciclovir-resistant strain, compared with that of its wild-type ganciclovir-sensitive counterpart. All nine of the ganciclovir-resistant strains were susceptible to foscarnet. Moreover, these strains were sensitive to inhibition both by vidarabine and 1-(29-deoxy-29-fluoro-beta-D-arabinofuranosyl)-5-iodocytosine (FIAC), antiviral agents that are activated by cellular enzymes, and by (S)-1(3-hydroxy-2-phosphonylmethoxypropyl)cytosine (HPMPC), which is a monophosphate nucleoside analog. The in vitro resistance to ganciclovir of the ganciclovir-resistant clinical isolates studied was attributed to the inability of the cells infected with these isolates to phosphorylate ganciclovir; the virally encoded DNA polymerase did not appear to play a role in this ganciclovir resistance. Images
High brightness InP micropillars grown on silicon with Fermi-level splits larger than 1 eV

The synthesis of III-V nanowires on silicon substrates is promising for reducing the manufacturing and balance-of-systems costs of III-V based photovoltaics. However, performances of III-V nanowire based solar cells have not yet been close to their bulk counterparts as nanostructures are fundamentally challenged by enhanced non-radiative losses due to their large surface-to-volume ratios, resulting in significantly reduced external fluorescence yields for spontaneous emission and therewith serious penalties in the open-circuit voltage. In this work, we report characteristics of micron-sized, single-crystalline, Wurzite-phased InP crystals directly grown on silicon substrates for photovoltaics applications. We found that under illumination intensities equivalent to 1 sun Fermi level splits can reach 0.89 eV in undoped InP pillars, 0.53 eV below the bandgap of wurtzite InP material at 1.42 e V. The brightness of pillars can be improved by doping the pillars which boosts radiative recombination rates inside the material and increases the brightness by more than an order of magnitude. In n-doped pillars, whose absorption edge is shifted to 1.49 eV due to the Burstein-Moss effect, Fermi-level splits larger than 1 eV are found, 0.46 eV below the absorption edge. Long non-radiative carrier lifetimes of 6.9 ns at room temprature further attest to the quality of the pillars. These results confirm that InP is a promising materials choice for photovoltaic devices in which the light absorber exhibits large surface-to-volume ratios.
Statistical Mechanics of Developable Ribbons

We investigate the statistical mechanics of long developable ribbons of finite width and very small thickness. The constraint of isometric deformations in these ribbonlike structures that follows from the geometric separation of scales introduces a coupling between bending and torsional degrees of freedom. Using analytical techniques and Monte Carlo simulations, we find that the tangent-tangent correlation functions always exhibit an oscillatory decay at any finite temperature implying the existence of an underlying helical structure even in the absence of a preferential zero-temperature twist. In addition, the persistence length is found to be over 3 times larger than that of a wormlike chain having the same bending rigidity. Our results are applicable to many ribbonlike objects in polymer physics and nanoscience that cannot be described by the classical wormlike chain model.
Efficient Articulated Model Fitting on a Single Image or a Sequence

Models that can efficiently, compactly, and semantically represent potential users are important tools for human-robot interaction applications. We model a person as a projection of a generic 3D articulated model and propose a method to estimate its joint positions from image data in an optimization framework. This is done by constructing a function that grades a configuration of joints according to how well it matches the underlying image and model based priors. We then search for local optimum in this space both efficiently and exhaustively by assembling partial configurations in a bottom-up manner. Working from the leaves of the tree to its root, we maintain a list of locally optimal, yet sufficiently distinct candidate configurations for the body pose. We then adapt this algorithm for use on a sequence of images to make it even more efficient by considering configurations that are near their position in the previous frame. This way, the number of partial configurations generated and evaluated significantly reduces. These algorithms are validated on real image data.
Bio-inspired artificial muscle structure for integrated sensing and actuation

In this paper, a novel artificial muscle/tendon structure is developed for achieving bio-inspired actuation and self-sensing. The hybrid structure consists of a dielectric elastomer (DE) material connected with carbon fibers, which incorporates the built-in sensing and actuation capability of DE and mechanical, electrical interfacing capability of carbon fibers. DEs are light weight artificial muscles that can generate compliant actuation with low power consumption. Carbon fibers act as artificial tendon due to their high electro-conductivity and mechanical strength. PDMS material is used to electrically and mechanically connect the carbon fibers with the DE material. A strip actuator was fabricated to verify the structure design and characterize its actuation and sensing capabilities. A 3M VHB 4905 tape was used as the DE material. To make compliant electrodes on the VHB tape, carbon black was sprayed on the surface of VHB tape. To join the carbon fibers to the VHB tape, PDMS was used as bonding material. Experiments have been conducted to characterize the actuation and sensing capabilities. The actuation tests have shown that the energy efficiency of artificial muscle can reach up to 0.7% and the strain can reach up to 1%. The sensing tests have verified that the structure is capable of self-sensing through the electrical impedance measurement.
Immune Mediators of protective and pathogenic immune responses in patients with mild and fatal human monocytotropic ehrlichiosis

Ehrlichia chaffeens is is a bacterial pathogen that causes fatal human monocytic ehrlichiosis (HME) that mimic toxic shock-like syndrome. Murine studies indicate that over activation of cellular immunity followed by immune suppression plays a central role in mediating tissue injury and organ failure during fatal HME. However, there are no human studies that examine the correlates of resistance or susceptibility to severe and fatal HME. In this study, we compared the immune responses in two patients with mild/non fatal and severe/fatal HME who had marked lymphopenia, thrombocytopenia and elevated liver enzymes. The levels of different immunological factors in the blood of those patients were examined and compared to healthy controls. Our data showed that fatal HME is associated with defective production of Th1 cytokines such as ( IFNγ and IL-2), increased anti-inflammatory (IL-10 and IL-13) and pro-inflammatory (TNF-α, IL-1α, IL-1β, and IL-6) cytokines, increased levels of macrophages, T cells, and NK cells chemokines such as MCP-1, MIP-1α, MIP-1β, but not RANTES and IP-10, increased levels of neutrophils chemokine and growth factor (IL-8 and G-CSF), and elevated expression of tumor necrosis factor receptor (TNFR), and toll like receptors 2 and 4 compared to patients with non fatal HME and healthy controls. Fatal Ehrlichia-induced toxic shock is associated with defective Th1 responses, possible immune suppression mediated by IL-10. In addition, marked leukopenia observed in patients with fatal disease could be attributed to enhanced apoptosis of leukocytes and/or elevated chemokine production that could promote migration of immune cells to sites of infection causing tissue injury.
Facilitating word-finding skills of language-impaired children.

Two language-impaired children and their controls participated in a preliminary study designed to examine the effects of treatment on word-finding skills. The 2 children participated in activities ...
Adaptive time-staged strategies for transportation investment

Typically, investments in transportation have involved large-scale, durable facilities with significant long-term consequences on both the environment and even the very lifestyle of a region. Traditional solutions to transportation problems have ignored the fact that significant changes have occurred over the last few years, however, in the demand for transportation, in the transportation technologies available, and most importantly in the way people value transportation service. The value of many current approaches to investment planning has been severely limited because they ignore these changes and the other uncertainties inherent in the planning environment. This paper presents an application of the general sequential decision model and an adaptive strategic approach to transport planning which lends itself to handling both uncertainties in future demands, technologies and values and to a more incremental staged sequential solution to the transport investment problem. A Bayesian learning model is developed which considers both the flexibility of the staged strategic approach as well as the flexibility and adaptability of technologies.
Regeneration of a tonic avian muscle: Transformation to a twitch morphology

Abstract The tonic anterior latissimus dorsi muscle of the pigeon was excised, minced into fine pieces, replaced into its original bed, and allowed to regenerate for periods up to 37 weeks. Although regeneration was asynchronous, regeneration patterns of the muscle fibers suggested the following sequence of fiber development: undifferentiated to tonic to twitch. Fiber types were identified on the basis of Z-line morphology and qualitative development and organization of the sarcotubular system as demonstrated by electron microscopy. Histochemical demonstration of myofibrillar adenosine triphosphatase and succinic dehydrogenase activities corroborated the morphological evidence, suggesting a transformation to a twitch morphology. In addition to the transformation to the twitch morphology, other alterations were observed in these regenerating fibers. Among these were large numbers of closely-packed 60-nm-diameter tubules, thought to be derived from the sarcoplasmic reticulum; mitochondria with intermembraneous dense material; and Z-line streaming. The transformation of the muscle fibers from tonic to twitch morphology is discussed in terms of alterations in nerve impulse activity to the regenerating muscle.
Predicting outcomes for cardiac surgery patients after intensive care unit admission.

Most performance assessments of cardiac surgery programs use models based on preoperative risk factors. Models that were primarily developed to assess performance in general intensive care unit (IC...
Rapid Semantic Annotation as an Evaluative Tool for Warning Symbol Design

A key step in the stereotype production method, and in other methods of warning symbol development, is the evaluation of symbol sketches produced by naive design participants. These sketches provide valuable insight into the expectations of potential warning symbol users about the content and design of the symbol. Until recently, the symbol development process depended heavily on designers’ expertise to judge the intent of a participant’s sketch and its similarities to other participants’ drawings. However, mathematical and computational techniques have been introduced that assist symbol designers by clustering similar sketches by their graphical attributes and evolving new designs from prior sketches based on the most preferred symbolic components. Semantic annotation is used to attach standardized descriptive terms to the sketches which the clustering process uses to discriminate between the otherwise very subjective symbol drawings. Unfortunately, semantic annotation can be a lengthy process of annotators studying the nuances of each sketch. This is incongruent with the real-world usage of warning symbols where an individual’s attention is fixated on a symbol for only a few seconds during which time the message must be received. The process of Rapid Semantic Annotation is proposed to better match the field experience of symbol users to the design process and to reduce the designers’ time spent on semantic annotation. Symbol sketches for two warning referents (“hot exhaust” and “do not touch with wet hands”) were taken from a previous study involving semantic annotation by an expert panel. Thirty sketches were randomly chosen from a larger pool for each referent and presented independently to 6 participants. Participants were given only 5 seconds to view the sketch before recording their semantic annotations in the form of textual terms (e.g. “person” or “flame”). A list of these “attributes” was aggregated from all participants for each of the 30 sketches in a referent, and an annotation matrix was created containing the count (0-6) of participants who annotated each attribute for each sketch. In total, 54 attributes were annotated for the “Hot Exhaust” referent (a 30 x 54 matrix) and 37 attributes were annotated for the “Wet Hands” referent (a 30 x 37 matrix). Weka Simple K-Means clustering was performed on the matrices, and the clustering results are compared to the results produced from the expert panel semantic annotation in the previous study.
The adsorption and thermal decomposition of PH3 on Si(111)-(7 × 7)

Abstract The adsorption of PH3, on Si(111)-(7 × 7) has been studied by Auger electron spectroscopy and temperature programmed desorption. PH3 was found to exhibit two kinds of behavior on the surface. A small surface coverage of molecularly adsorbed PH3 desorbs without any dissociative surface chemistry. For the majority of the adsorbed PHx species (3 ⩾ x ⩾ 1) dissociation occurs to form P(a) and H(a). At 120 K, PH3 initially adsorbs as the reactive species with a sticking coefficient of S ≅ 1 up to ∼75% saturation. The reactive PHx species surface concentration saturates at (1.9 ± 0.3) × 1014 PHx cm−2. Surface H(a), produc thermal decomposition, desorbs as H2(g) at T > 700 K., and P(a) desorbs as P2(g) at T > 900 K. Capping the Si-dangling bonds with atomic deuterium prevents PH3 adsorption, indicating that the dangling bonds are the PH3 adsorption sites. Isotopic studies involving Si-D surface species mixed with adsorbed PHx species indicate that PH3 desorption does not occur through a recombination process. Finally, additional PH3 may be adsorbed if the surface hydrogen produced by dissociation of PH3 is removed. Evidence for P penetration into bulk Si(111) at 875 K is presented.
Low-Moisture Blocks: A Tool to Promote Uniform Utilization by Cattle?

Learn how to achieve uniform utilization across pastures that are partially burned. DOI:10.2458/azu_rangelands_v29i2_thrift
Kinetics of inhibition of β-amyloid aggregation by transthyretin

Deposition of beta-amyloid (Abeta) fibrils is an early event in the neurodegenerative processes associated with Alzheimer's disease. According to the "amyloid cascade" hypothesis, Abeta aggregation, and its subsequent deposition as fibrils, is the underlying cause of disease. Abeta is a proteolytic product of amyloid precursor protein (APP); several mutations in APP have been identified that are associated with early onset of disease. Transgenic mice overexpressing APP with the Swedish mutation develop numerous plaques but, surprisingly, lack the neurofibrillary tangles and neuronal loss characteristic of Alzheimer's disease, in apparent contradiction of the amyloid cascade hypothesis. However, recent studies suggest that coproduction of sAPPalpha, an alternative proteolytic product of APP, increases synthesis of transthyretin that, in turn, interacts directly with Abeta to inhibit its toxicity. Here we report results from biophysical analysis of Abeta aggregation kinetics in the presence of transthryetin. At substoichiometric ratios, transthyretin drastically decreased the rate of aggregation without affecting the fraction of Abeta in the aggregate pool. Detailed analysis of the data using a mathematical model demonstrated that the decrease in aggregation rate was due to both a decrease in the rate of elongation relative to the rate of initiation of filaments and a decrease in lateral association of filaments to fibrils. Tryptophan quenching data indicated that transthyretin binds weakly to Abeta, with an estimated apparent KS of 2300 M-1. Taken together, the data support a hypothesis wherein transthyretin preferentially binds to aggregated rather than monomeric Abeta and arrests further growth of the aggregates.