cssi/SciSciGPT-SciSciNet huggingface dataset:
Improved DCT-based image coding and decoding methods for low-bit-rate applications

Department of Electrical and Computer EngineeringUniversity of California Santa Barbara, CA 93106-9560ABSTRACTThe discrete cosine transform (DCT) is well known for highly efficient coding performance, and it is widely used in many imagecompression applications. However, in low-bit rate coding, it produces undesirable block artifacts that are visually not pleasing.In addition, in many applications, faster computation and easier VLSI implementation of DCT coefficients are also importantissues. The removal of the block artifacts and faster DCT computation are therefore of practical interest.In this paper, we outline a modified DCT computation scheme that provides a simple efficient solution to the reduction of theblock artifacts while achieving faster computation. We also derive a similar solution for the efficient computation of the inverseDCT. We have applied the new approach for the low-bit rate coding and decoding of images. Initial simulation results on realimages have verified the improved performance obtained using the proposed method over the standard JPEG method.1. INTRODUCTIONDiscrete transform of finite-length sequences play an important role in many signal processing applications. To this end, variousdiscrete transform families have been advanced along with the fast algorithms for their computations. Of these transforms, thediscrete cosine transform (DCT) is generally recognized as the best and effective way to encode image information [1]. Forcompression of a highly correlated image, the DCT approaches the optimum performance of the Karhunen Loeve Transform(KLT) [2]. As a result, the DCT has been adopted in the JPEG coding standard for still images [3] and the MPEG coding standardfor video images. However, in very low bit rate coding, the DCT exhibits severe block artifacts which are often undesirable. Anumber of researchers have investigated the reduction of block artifacts [4]-[7]. Likewise, the research for the fast DCTcomputation algorithms also has been carried out [8]-[1 1]. However, all of the work reported so far for reducing the blockartifacts and for fast computation have treated these problems separately. We provide a simultaneous solution to these twoproblems using a subband decomposition of the DCT,First, we describe the general concept of subband DCT (SB-DCT) in Section 2. Next, in Section 3 we use it to compute effi-ciently the approximate values of the dominant DCT samples, and then outline a simple and fast data compression technique usingthe SB-DCT. Then, in Section 4 we apply this new idea to image coding in the framework of the JPEG. Finally in Section 5
Circuit cavity electromechanics in the strong-coupling regime

Demonstrating and exploiting the quantum nature of macroscopic mechanical objects would help us to investigate directly the limitations of quantum-based measurements and quantum information protocols, as well as to test long-standing questions about macroscopic quantum coherence. Central to this effort is the necessity of long-lived mechanical states. Previous efforts have witnessed quantum behaviour, but for a low-quality-factor mechanical system. The field of cavity optomechanics and electromechanics, in which a high-quality-factor mechanical oscillator is parametrically coupled to an electromagnetic cavity resonance, provides a practical architecture for cooling, manipulation and detection of motion at the quantum level. One requirement is strong coupling, in which the interaction between the two systems is faster than the dissipation of energy from either system. Here, by incorporating a free-standing, flexible aluminium membrane into a lumped-element superconducting resonant cavity, we have increased the single-photon coupling strength between these two systems by more than two orders of magnitude, compared to previously obtained coupling strengths. A parametric drive tone at the difference frequency between the mechanical oscillator and the cavity resonance dramatically increases the overall coupling strength, allowing us to completely enter the quantum-enabled, strong-coupling regime. This is evidenced by a maximum normal-mode splitting of nearly six bare cavity linewidths. Spectroscopic measurements of these 'dressed states' are in excellent quantitative agreement with recent theoretical predictions. The basic circuit architecture presented here provides a feasible path to ground-state cooling and subsequent coherent control and measurement of long-lived quantum states of mechanical motion.
The effect of experimental parameters on the synthesis of carbon nanotube/nanofiber supported platinum by polyol processing techniques

Abstract Developing corrosion resistant carbon nanotube (CNT) and carbon nanofiber (CNF) supported Pt catalysts with optimized particle size is important for proton exchange membrane fuel cells. We investigated the effects of deposition technique (conventional refluxing and microwave irradiation), water content, carbon support and metal loading on the average Pt particle size and electrochemically active surface area (ECSA). BET surface area measurements, Fourier transform infrared spectroscopy, X-ray diffraction, thermal gravimetric analysis, transmission electron microscopy and cyclic voltammetry were used to characterize all the CNT/CNF supported catalysts. Processing was accelerated via microwave irradiation without significantly affecting Pt particle size as compared to conventional refluxing especially for high surface area CNT supported low Pt loading (10 wt%) catalyst. Adjusting the water content during synthesis effectively controlled the Pt particle size and size distribution regardless of the heating method, carbon support and metal loading. The ECSA of the samples was found to be dependent on Pt particle size which further depends on the water content during synthesis, support surface area and Pt loading. Optimization of deposition conditions leads to higher ECSA than seen in a commercially available carbon black supported catalyst.
Interaction of the opiate antagonist, naltrexone methyl bromide, with the acetylcholine receptor system of the motor end-plate

Naltrexone methyl bromide (NMB) caused alterations in both the amplitude and the time course of end-plate currents (EPC) recorded from rat muscle. The amplitudes were significantly lower than control, and the EPC decay was no longer singly exponential. There was also a decrease in the voltage dependence of the peak amplitude and the decay time constant of the EPCs. These findings suggest NMB is blocking the open state of the acetylcholine channel.
The finite element method in the solution of unbounded potential flows

A simple, yet effective, finite element approach to aerodynamic problems is presented. A better approximation of the geometry is obtained by the mapping of airfoils into near-circles. The mapping serves in homogenizing the gradients of the problem by magnifying regions of high gradients such as the leading and trailing edges while geometrically condensing the lower gradient regions on the main part of the airfoil. The mapping also permits the use of an effective automated mesh generation scheme that greatly reduces the amount of preparatory work involved in finite elements. To limit the size of the solution domain, an asymptotic analytical solution, with unknown coefficients, is assumed on a finite radius outer contour. The coefficients are obtained along with the finite element nodal unknowns. An accrued advantage of this patching asymptotic procedure is its ability to obtain the lift as a solution variable without having to resort to the numerical integration of the pressure field over the body. Solutions to non-lifting and lifting bodies are obtained.
An Empirical Model for the Complex Dielectric Permittivity of Soils as a Function of Water Content

The recent measurements on the dielectric properties of soils have shown that the variation of dielectric constant with moisture content depends on soil types. The observed dielectric constant increases only slowly with moisture content up to a transition point. Beyond the transition it increases rapidly with moisture content. The moisture value at transition region was found to be higher for high clay content soils than for sandy soils. Many mixing formulas reported in the literature were compared with, and were found incompatible with, the measured dielectric variations of soil-water mixtures. A simple empirical model was proposed to describe the dielectric behavior of the soil-water mixtures. This model employs the mixing of either the dielectric constants or the refraction indices of ice, water, rock, and air, and treats the transition moisture value as an adjustable parameter. The calculated mixture dielectric constants from the model were found to be in reasonable agreement with the measured results over the entire moisture range of 0-0.5 cm3/cm3. The transition moistures derived from the model range from 0.16 to 0.33 and are strongly correlated with the wilting points of the soils estimated from their textures. This relationship between transition moisture and wilting point provides a means of estimating soil dielectric properties on the basis of texture information.
Alterations of Chemosensory Function in End-Stage Liver Disease

Taste and smell dysfunction has been documented in patients with both acute and chronic liver disease. The purpose of this study was to determine if chemosensory function is improved after restoration of hepatic function with liver transplantation. Nine subjects (seven women and two men) with end-stage liver disease participated in the study. Taste and smell detection and recognition thresholds were determined before and after transplantation. A significant improvement in detection of the taste of sodium chloride and the odor of phenethyl alcohol was found after transplantation. These findings may have clinical significance in food choices and nutritional status of these patients.
Robust Circadian Oscillations in Growing Cyanobacteria Require Transcriptional Feedback

The remarkably stable circadian oscillations of single cyanobacteria enable a population of growing cells to maintain synchrony for weeks. The cyanobacterial pacemaker is a posttranslational regulation (PTR) circuit that generates circadian oscillations in the phosphorylation state of the clock protein KaiC. Layered on top of the PTR is transcriptional-translational feedback regulation (TTR), common to all circadian systems, consisting of a negative feedback loop in which KaiC regulates its own production. We found that the PTR circuit is sufficient to generate oscillations in growing cyanobacteria. However, in the absence of TTR, individual oscillators were less stable and synchrony was not maintained in a population of cells. Experimentally constrained mathematical modeling reproduced sustained oscillations in the PTR circuit alone and demonstrated the importance of TTR for oscillator synchrony.
Entrepreneurs in Action: A Web-Case Model.

Much of traditional schooling in America is built around systems of compliance and control, characteristics which stifle the creative and entrepreneurial instincts of the children who are subjected...
Auxin-stimulated somatic embryogenesis from immature cotyledons of white clover.

Cotyledons from immature embryos of white clover (Trifolium repens L.) cv. Osceola were exposed to 2,4-D or NAA to induce somatic embryogenesis. NAA at 10 or 20 mg 1−1 was very inefficient at stimulating embryogenesis, while concentrations of 30 or 40 mg 1−1 resulted in death of the explant tissue. Continuous exposure of cotyledons to 40 mg 1−1 2,4-D resulted in somatic embryos which were arrested at the globular stage, or which underwent cycles of secondary embryogenesis, never proceeding beyond the globular stage. A 10 day exposure time to 2,4-D at the same concentration led to formation of somatic embryos, most of which had poorly developed cotyledons. Almost 10% of the somatic embryos converted into plants following transfer to medium devoid of growth regulators. Attempts to improve morphology of somatic embryos by using shorter exposure times to 2,4-D at 40 mg 1−1, or by maintaining the 10 day exposure time while varying the concentration of 2,4-D, were not successful. Plants were obtained from all parents evaluated, although at different frequencies.
Isolation of estrone and cholesterol from the date palm, Phoenix dactylifera L

Abstract The presence of estrone in date palm seeds and pollen was demonstrated by thin-layer chromatography, isolation, i.r. spectrum, and reduction to estradiol. Cholesterol was obtained from date palm pollen and identified by thin-layer chromatography, isolation, i.r. spectrum, and conversion to cholesterol acetate.
Nestbox availability affects extra-pair fertilizations and conspecific nest parasitism in eastern bluebirds, Sialia sialis

Abstract Eastern bluebird pairs are usually monogamous, cooperating in caring for their offspring. However, alternative reproductive tactics including copulations with more than one partner and the laying of eggs in nests of conspecifics also occur. These alternative reproductive tactics could be adaptive when nest site availability varies, and different predictions have been made of who should employ these tactics, and when. Two experiments involving manipulation of nestboxes discriminated between these possibilities. The first experiment involved placement of nestboxes so that breeding pairs of bluebirds were relatively close together, a standard distance apart or relatively far apart. Nestlings non-descendant (measured using isozyme exclusion analysis) from one or both of their putative parents, the male and female care-givers, were least likely when nesting territories were relatively far apart and scarce, and increased significantly in experimental areas where nesting pairs were relatively close together and abundant, allowing the inference that neighbours were the source of non-directly descendant offspring. This is the first experimental evidence for birds demonstrating that individuals engage in genetically effective alternative reproductive tactics as a function of their opportunity to do so. The second experiment involved removal of nestboxes so that only two-thirds of known breeders had nesting sites. The rate of conspecific nest parasitism increased after removal providing the first experimental evidence for alternative reproduction by females when nest sites were not available. These two experiments were performed sequentially over two years. During these years extra-pair fertilization was significantly more frequent than conspecific nest parasitism.
Discontinuous Galerkin Method for Internal Thermal Radiation Problems

The internal thermal radiation phenomena are described by a first-order integral-differential equation, which poses an intrinsic problem for the popular diffusion-based Galerkin finite element method. By allowing for discontinuity across the internal inter-element boundaries, the finite element procedure can be adapted to solve the integral-differential equation. This paper discusses a numerical procedure based on the discontinuous Galerkin method for the solution of radiation heat transfer involving participating media. Detailed formulation using the discontinuous Galerkin method for internal radiation heat transfer calculations is given. The coupling of the method with the conventional finite element method for mixed heat transfer calculations is also presented.Copyright © 2003 by ASME
Evaluation of a Temperature-Sensitive Mutant of Respiratory Syncytial Virus in Adults

A temperature-sensitive {ts) mutant of respiratory syncytial virus, which was unable to replicate at 37 C in vitro, was administered by the nasopharyngeal route to adults who had low levels of neutralizing antibody in their nasal secretions. The ts mutant appeared to be attenuated under these conditions as indicated by a decrease in infectivity and by the asymptomatic nature of the infections that occurred. The ts mutant was genetically stable in vivo, and there was no evidence of reversion to wild type after replication in the upper respiratory passages of the volunteers. Although the mutant appeared to be attenuated, it did induce a state of resistance to subsequent challenge with wild-type (virulent) virus. These encouraging results suggest that the ts mutant should be further evaluated as a candidate for a vaccine for prevention of serious respiratory syncytial viral disease in the lower respiratory tract of young infants.
SELF‐ESTEEM AND RACIAL PREFERENCE IN BLACK CHILDREN

In the 1950s and early 1960s, studies of racial preference of children consistently showed black children choosing white models and rejecting dark models. The present study of black children growing up since 1963 indicates a reversal of this position. The authors interpret their findings as a reflection of a more accepting incorporation of racial identity and pride within the child's self-concept.
High-numerical-aperture reflecting microscope

A microscope having a high effective numerical aperture is achieved in an apparatus in which a real, 3D image is formed of an object placed along the axis of one of two facing concave mirrors and is acquired by a video camera, preferably a CCD, positioned along the axis of the other mirror. The image acquired by the CCD is electronically stored and then analyzed. Magnification is introduced by the spacing of the sensors of the CCD array. With exemplary CCD sensor spacing of 10 microns, resolution of about 10 microns (10-5 meters) is achievable using commercial 8-inch diameter concave mirrors. The high numerical aperture of the reflecting microscope offers the advantages of being able to more rapidly acquire an image at a lower light level than is possible with a slit lamp microscope which requires that the object be physically scanned with a high intensity light.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The Tempest UAS: The VORTEX2 Supercell Thunderstorm Penetrator

The Tempest UAS was developed to demonstrate the feasibility of in-situ sampling of supercell thunderstorms with small unmanned aircraft, operating under the constraints of FAA certificates of authorization. The UAS and the mission concept of operations were validated with the interceptions and sampling of six supercell thunderstorms during the spring 2010 VORTEX2 field deployment. A description of the science drivers for the engineering requirements is presented. The mission concept of operations that determined the performance requirements for the airframe, and command, control, and communications systems are then discussed, and results of the supercell flights are shown.
Sweet Changes: Glucose Homeostasis Can Be Altered by Manipulating Genes Controlling Hepatic Glucose Metabolism

The liver is responsible for glucose synthesis in the fasting state, and glucose uptake, storage, and utilization in the fed state. A phenotypic switch, normally initiated by insulin or glucagon, controls the transition between the two states, which includes transcriptional alterations that regulate metabolic enzyme abundance for multiple metabolic pathways in a coordinated manner. A network of transcription factors, coactivators, and corepressors direct these changes, thus acting as transcriptional sensors of the nutritional status of an organism. The inability of the hepatocyte to undergo this metabolic reprogramming is characteristic of diabetes mellitus. Modulations that control the amount of individual metabolic enzymes or transcription factors can initiate the fasting-to-fed transition of the hepatocyte in an insulin-independent manner. Alternatively, overexpression of key regulators of metabolism can lock hepatocytes in the fasted state. These manipulations alter hepatic glucose flux, leading to either amelioration or induction of diabetes mellitus. These maneuvers reveal the complexity of the coordinated mechanisms used by the liver to alter its phenotype and provide evidence for the control strength of metabolic signaling.
CoCONet: A collision-free container-based core optical network

Electrical-to-optical domain conversions and vice versa (denoted by O/E/O conversions) for each hop in optical core transport networks impose considerable capital and financial overhead on the providers. In this paper, we propose a full-mesh topology driven core network with a central scheduler that handles the task of signaling and coordination among slot transmissions for every hop to eliminate such O/E/O conversions. We introduce the concept of a container as a macro data unit that forms a separate layer in the protocol stack above the optical layer. A FAST centralized scheduling algorithm is proposed based on a preemptive scheduling technique that can ensure that there are no collisions between the containers. We also analyze the complexity of this algorithm. Next we design the logical architecture for the core and edge switches following the de facto policy of moving the complexity to the edge. We also designed a hierarchical architecture for the edge switch and provide the respective block diagrams. To get a more concrete design prototype, we further proposed a generic (vendor independent) physical architecture for a single port of the switch considering SONET/SDH on the access side. Moreover, we develop a concise delay model for the containers to analyze the packet arrival process and derive the optimal container size, based on the link speed. Finally, we present some simulation results to study the performance of the algorithms and models proposed in our work.
Interactions between the Cytochrome b, Cytochrome c1, and Fe−S Protein Subunits at the Ubihydroquinone Oxidation Site of the bc1 Complex of Rhodobacter capsulatus†

Ubihydroquinone:cytochrome (cyt) c oxidoreductase (bc1 complex and its plant counterpart b6f complex) is a vital component of energy-transducing systems in most organisms from bacteria to eukaryotes. In the facultative phototrophic (Ps) bacterium Rhodobacter capsulatus, it is constituted by the cyt b, cyt c1, and Rieske Fe-S protein subunits and is essential for Ps growth. Of these subunits, cyt b has two nontransmembrane helices, cd1 and cd2, which are critical for its structure and function. In particular, substitution of threonine (T) at position 163 on cd1 with phenylalanine (F) or proline (P) leads to the absence of the bc1 complex. Here, Ps+ revertants of B:T163F were obtained, and their detailed characterizations indicated that position 163 is important for the assembly of the bc1 complex by mediating subunit interactions at the Qo site. The loss of the hydroxyl group at position 163 of cyt b was compensated for by the gain of either a hydroxyl group at position 182 of cyt b or 46 of the Fe-S protein or a sulfhydryl group at position 46 of cyt c1. Examination of the mitochondrial bc1 complex crystal structure [Zhang, Z., Huang, L., Shulmeister, V. M., Chi, Y.-I., Kim, K. K., Hung, L.-W., Crofts, A. R., Berry, E. A., and Kim, S.-H. (1998) Nature 392, 677-684] revealed that the counterparts of B:G182 (i.e., G167) and F:A46 (i.e. , A70) are located close to B:T163 (i.e., T148), whereas the C:R46 (i.e., R28) is remarkably far from it. The revertants contained substoichiometric amounts of the Fe-S protein subunit and exhibited steady-state and single-turnover, electron transfer activities lower than that of a wild-type bc1 complex. Interestingly, their membrane supernatants contained a smaller form of this subunit with physicochemical properties identical to those of its membrane-bound form. Determination of the amino-terminal amino acid sequence of this soluble Fe-S protein revealed that it was derived from the wild-type protein by proteolytic cleavage at V44. This work revealed for the first time that position 163 of cyt b is important both for proper subunit interactions at the Qo site and for inactivation of the bc1 complex by proteolytic cleavage of its Fe-S protein subunit at a region apparently responsible for its mobility during Qo site catalysis.
Electrical Contacts between Cathodes and Metallic Interconnects in Solid Oxide Fuel Cells

In this work, simulated cathode/interconnect structures were used to investigate the effects of different contact materials on the contact resistance between a strontium doped lanthanum ferrite cathode and a Crofer22 APU interconnect. Among the materials studied, Pt, which has a prohibitive cost for the application, demonstrated the best performance as a contact paste. For the relatively cost-effective perovskites, the contact ASR was found to depend on their electrical conductivity, scale growth on the metallic interconnect, and interactions between the contact material and the metallic interconnect or particularly the scale grown on the interconnect. Manganites appeared to promote manganese-containing spinel interlayer formation that helped minimize the increase of contact ASR. Chromium from the interconnects reacted with strontium in the perovskites to form SrCrO4. An improved performance was achieved by application of a thermally grown (Mn,Co)3O4 spinel protection layer on Crofer22 APU that dramatically minimized the contact resistance between the cathodes and interconnects.
Physiological Roles of Glutamate Signaling in Gut and Brain Function

Some ingested nutrients have postingestive effects that modulate food intake and improve mood subconsciously. Here, we provide an overview of the positive postingestive effects of such nutrients, primarily L-glutamate, sugar, and lipids, with respect to behavior and brain function. We also discuss the mechanisms of brain activation resulting from signaling through the gut-brain axis. Recent studies have shown that rats prefer solutions paired with intragastric nutrients that have positive postingestive effects. Using functional magnetic resonance imaging (fMRI), we previously evaluated neural activation in response to ingested glucose, L-glutamate, and corn oil emulsion in rats and found that distinct forebrain regions were activated by these nutrients. Most of the areas activated by intragastric administration of L-glutamate were eliminated by abdominal vagotomy. On the other hand, the areas activated by intragastric administration of glucose were not affected by vagotomy. A behavioral study showed similar results for L-glutamate and glucose. These results indicate that brain activation in response to ingested nutrients occurs through distinct internal signals from the gut to the brain. Distinct regional and temporal activation in the brain determines the variety of postingestive behaviors and physiological responses.
An atomistically-informed dislocation dynamics model for the plastic anisotropy and tension–compression asymmetry of BCC metals

Abstract Atomistic simulations have shown that a screw dislocation in body-centered cubic (BCC) metals has a complex non-planar atomic core structure. The configuration of this core controls their motion and is affected not only by the usual resolved shear stress on the dislocation, but also by non-driving stress components. Consequences of the latter are referred to as non-Schmid effects. These atomic and micro-scale effects are the reason slip characteristics in deforming single and polycrystalline BCC metals are extremely sensitive to the direction and sense of the applied load. In this paper, we develop a three-dimensional discrete dislocation dynamics (DD) simulation model to understand the relationship between individual dislocation glide behavior and macro-scale plastic slip behavior in single crystal BCC Ta. For the first time, it is shown that non-Schmid effects on screw dislocations of both {110} and {112} slip systems must be implemented into the DD models in order to predict the strong plastic anisotropy and tension–compression asymmetry experimentally observed in the stress–strain curves of single crystal Ta. Incorporation of fundamental atomistic information is critical for developing a physics-based, predictive meso-scale DD simulation tool that can connect length/time scales and investigate the underlying mechanisms governing the deformation of BCC metals.
Physical properties and life prediction of TMC at elevated temperatures

Abstract Mechanical performance of titanium matrix composites degrades at elevated temperatures because of the changes in physical properties of the composites (i.e. matrix oxidation, embrittlement and phase transformation). These physical properties of the composites should be taken into account in a life prediction model. The present study was conducted to improve an existing life prediction model (local fiber stress failure model). To achieve this goal, isothermal fatigue tests were performed on [0/±45/90] s SCS-6/Timetal 21S composite at temperatures 400 and 500 °C, and with hold times. The composite lives at 400 and 500 °C increased with increase in hold time. It was observed that the matrix oxidation was accelerated under applied stress amplitude. In addition, the measurement of the surface oxide thickness suggested that the oxidation was much easier and faster at 500 °C than at 400 °C. A modification was made on the life prediction model. Since the oxidation was shown to have a significant effect on the composite life, it was factored into the model. The modified model produced a good correlation between modified single parameter value and the number of cycles to failure.
Laser-based fiberoptic immunosensors

This paper provides a brief overview of the development and application of fiber-optic antibody-based fluoroimmunosensors (FIS) for measuring environmental pollutants and related biomarkers of human exposure and health effects. The FIS combines the excellent specificity of the antigen/antibody reaction, the high sensitivity of laser excitation, and the versatility of fiber-optics technology. Various types of FIS devices were also used to detect toxic chemicals (such as benzo-a-pyrene) and related DNA adducts (e.g., benzo(a)pyrene tetrol).
A one‐year experimental Arctic reanalysis and comparisons with ERA‐40 and NCEP/NCAR reanalyses

[1] A one-year (1998) experimental Arctic reanalysis was produced using an experimental Arctic reanalysis system (EARS), which was based on the MM5 model and 3DVAR data assimilation, implemented in combination with an intermittent nudging scheme. TOVS retrieval data and conventional surface observations and upper-air sounding data are assimilated by EARS, which is driven by the ERA-40 reanalysis. The domain covers a pan-Arctic region at a horizontal resolution of 30 km. The EARS reanalysis results, as well as ERA-40 and NCEP/NCAR reanalyses (NNRP), are verified against station observations. Comparisons show that the ERA-40 analysis is significantly better than NNRP for the metrics of root-mean-square error and bias. The EARS performed significantly better than both ERA-40 and NNRP at lower levels; it produced especially good results for surface wind and upper-air humidity. For the surface temperature, dew point, relative humidity, sea level pressure, as well as upper-air variables, the yearly average of the EARS results lie in between those of the ERA-40 and NNRP, closer to those of ERA-40.
Acoustical effects of endotracheal intubation.

Certain acoustical consequences of endotracheal intubation were examined in 13 male cardiovascular-surgery patients. Each subject recorded three tokens of a sustained vowel 1 day before intubation,...
TEM investigation of the plastic deformation behaviour of calcium fluoride

Abstract Cold–stage transmission electron microscopy is shown to eliminate any observable ionization radiation damage in calcium fluoride, thereby providing conditions suitable for performing TEM of the deformation microstructures. Stage II α consists of dislocation walls composed of primary and secondary dislocations. Work hardening during Stage IIα results from the formation of blocking obstacles, forest interactions and jogs. Stage IIβ is characterized by the formation of a dislocation cell structure and a secondary dislocation density much higher than Stage II α. The shear stress during Stage IIβ is correlated to the secondary dislocation density in a manner consistent with forest dislocation models of work hardening based on repulsive trees. The microstructure of Stage III is composed of a' block' cell structure with a cell size less than that of Stage IIβ. Single–crystalline calcium fluoride has been compressed under an initial strain rate of 5–64 × 10–3 per minute at 200, 300 and 400°C to establish...
Determination of time-resolved MCD spectra: Electronic transitions in the spectrum of the 3Eu excited state in Al(III) trisulfonatephthalocyanine

Abstract A new procedure for the flash photochemical determination of the MCD spectrum of reaction intermediates is reported. The method has been applied to the measurement of the time-resolved MCD of the 3 E u excited state in Al(III) phthalocyanine.
Averaged occipital responses to stimulation of sites in the nasal and temporal halves of the retina

Responses of the right occipital lobe to flashes imposed on the nasal retina of the right eye were smaller than responses to flashes imposed on the temporal retina. Since reaction times are shorter to nasal than to temporal stimulation of the retina, the above result is inconsistent with existing evidence for an inverse relation between evoked response amplitude and reaction time. The inconsistency may be related to the fact that the right occipital lobe receives no projections from the nasal retina of the right eye.
A novel end-to-end binding of two netropsins to the DNA decamers d(CCCCCIIIII)2, d(CCCBr5CCIIIII)2 and d(CBr5CCCCIIIII)2

Netropsin is bound to the DNA decamer d(CCCCCIIIII)2, the C-4 bromo derivative d(CCCBr5CCIIIII)2and the C-2 bromo derivative d(CBr5CCCCIIIII)2in a novel 2:1 mode. Complexes of the native decamer and the C-4 bromo derivative are isomorphous, space group P1, unit cell dimensions a = 32.56 A (32.66), b = 32.59 A (32.77), c = 37.64 A (37.71), alpha = 86.30 degrees (86.01 degrees), beta = 84.50 degrees (84.37 degrees), gamma = 68.58 degrees (68.90 degrees) with two independent molecules (A and B) in the asymmetric unit (values in parentheses are for the derivative). The C-2 bromo derivative is hexagonal P61, unit cell dimensions a = b = 32.13 A, c = 143.92, gamma = 120 degrees with one molecule in the asymmetric unit. The structures were solved by the molecular replacement method. The novelty of the structures is that there are two netropsins bound end-to-end in the minor groove of each B-DNA decamer which has nearly a complete turn. The netropsins are held by hydrogen bonding interactions to the base atoms and by sandwiching van der Waal's interactions from the sugar-phosphate backbones of the double helix similar to every other drug.DNA complex. Each netropsin molecule spans approximately 5 bp. The netropsins refined with their guanidinium heads facing each other at the center, although an orientational disorder for the netropsins cannot be excluded. The amidinium ends stretch out toward the junctions and bind to the adjacent duplexes in the columns of stacked symmetry-related complexes. Both cationic ends of netropsin are bridged by water molecules in one of the independent molecules (molecule A) of the triclinic structures and also the hexagonal structure to form pseudo-continuous drug.decamer helices.
Hepatobiliary Transport: Molecular Mechanisms of Development and Cholestasis

The secretion of bile requires the vectorial transport of organic and inorganic solutes from sinusoidal blood to the canalicular lumen. Hydrostatic forces cannot account for biliary secretion, because secretory pressures within bile ducts exceed that of blood within the sinusoidal space. Instead, the process of bile formation requires active transport across the basolateral membrane, transcellular movement through a variety of mechanisms, and then active transport into the canalicular space between hepatocytes. Separate hepatic and ductular transport mechanisms allow for rapid regulation of bile volume and composition required for changing physiologic needs. The array of transport proteins localized to both poles of the hepatocyte have been characterized physiologically and during development. Many have now been cloned and studied further in transgenic models. The recent identification and characterization of several genes that are mutated in inherited forms of cholestatic liver disease have provided new insight into the normal physiology of bile secretion, the pathophysiology of intrahepatic cholestasis, and an unexpected major role for a novel group of P-type ATPases in human biology and disease.
Pulse-by-pulse measurements of dynamic retention and deposition in NSTX

Abstract Three quartz crystal microbalances have been deployed in NSTX to measure deposition/erosion in plasma shadowed areas at the upper and lower divertor and outboard midplane. These show a complex pattern of material gain and loss. At the time of a plasma discharge a transient increase in mass of order ∼0.1 μg cm −2 is observed that decays in the interpulse period to a level either higher, lower or similar to that prior to the discharge. The first discharge of the day always shows a long term step-up in mass. Some correlations of mass gain with plasma duration, stored energy, and change in the plasma shape are observed. Following a days plasma operations, a slow decay in mass is observed. The results are interpreted in terms of dynamic retention and erosion/deposition.
Personal Computer-Based 3-Dimensional Ultrasound Biomicroscopy of the Anterior Segment

Objective: To develop a practical, inexpensive system for 3-dimensional ultrasound biomicroscopic imaging of the anterior segment with a commercially available high-frequency ultrasound imager and a personal computer. Methods: Sequential, high-frequency, ultrasound biomicroscopic images of the anterior segment were obtained with a motorized scanning control arm designed in our imaging laboratory. Images were acquired by a personal computer—based video capture device. Ultrasound slice data were then reconstructed as 3-dimensional volumetric images by a personal computer and commercially available software. Results: Four 3-dimensional visualization formats were developed to enhance the clinical utility of high-frequency ultrasound. Rotational animation sequences were created that detailed the extent and anatomy of a filtering bleb, intraocular lens subluxation, focal angle closure from an iridociliary cyst, intraocular foreign bodies, and an iris tumor. Conclusions: Three-dimensional, high-frequency ultrasound of the anterior segment enhances our ability to visualize spatial relationships between adjacent anatomic structures. The low cost and ease of use of this system make widespread clinical application practical.
Model Evaluation by Comparison of Model-Based Predictions and Measured Values

The appropriateness of a statistical analysis for evaluating a model depends on the model's purpose. A common purpose for models in agricultural research and environmental management is accurate prediction. In this context, correlation and linear regression are frequently used to test or compare models, including tests of intercept a = 0 and slope b = 1, but unfortunately such results are related only obliquely to the specific matter of predictive success. The mean squared deviation (MSD) between model predictions X and measured values Y thus been proposed as a directly relevant measure of predictive success, with MSD partitioned into three components to gain further insight into model performance. This paper proposes a different and better partitioning of MSD: squared bias (SB), nonunity slope (NU), and lack of correlation (LC). These MSD components are distinct and additive, they have straightforward geometric and analysis of variance (ANOVA) interpretations, and they relate transparently to regression parameters. Our MSD components are illustrated using several models for wheat (Triticum aestivum L.) yield. The MSD statistic and its components nicely complement correlation and linear regression in evaluating the predictive accuracy of models.
Dynamic collusion in an open economy

Abstract This paper provides an example of how opening a country to trade may decrease competition in an industry. This result, counter to conventional theory, occurs when one considers multi-period games.
Mutagenesis of amino acid residues in the SHV-1 β-lactamase: the premier role of Gly238Ser in penicillin and cephalosporin resistance

Abstract The recent availability of the SHV-1 β-lactamase crystal structure provides a framework for the understanding of the functional role of amino acid residues in this enzyme. To that end, we have constructed by site-directed mutagenesis 18 variants of the SHV β-lactamase: an extended spectrum group: Gly238Ser, Gly238Ser-Glu240Lys, Asp104Lys-Gly238Ser, Asp104Lys-Thr235Ser-Gly238Ser, Asp179Asn, Arg164His, and Arg164Ser; an inhibitor resistant group: Arg244Ser, Met69Ile, Met69Leu, and Ser130Gly; mutants that are synergistic with those that confer resistance to oxyimino-cephalosporins: Asp104Glu, Asp104Lys, Glu240Lys, and Glu240Gln; and structurally conserved mutants: Thr235Ser, Thr235Ala and Glu166Ala. Among the extended spectrum group the combination of high-level ampicillin and cephalosporin resistance was demonstrated in the Escherichia coli DH10B strains possessing the Gly238Ser mutation: Gly238Ser, Gly238Ser-Glu240Lys, Asp104Lys-Gly238Ser, and Asp104Lys-Thr235Ser-Gly238Ser. Of the inhibitor resistant group, the Ser130Gly mutant was the most resistant to ampicillin/clavulanate. Using a polyclonal anti-SHV antibody, we assayed steady state protein expression levels of the SHV β-lactamase variants. Mutants with the Gly238Ser substitution were among the most highly expressed. The Gly238Ser substitution resulted in an improved relative kcat/Km value for cephaloridine and oxyimino-cephalosporins compared to SHV-1 and Met69Ile. In our comparative survey, the Gly238Ser and extended spectrum β-lactamase variants containing this substitution exhibited the greatest substrate versatility against penicillins and cephalosporins and greatest protein expression. This defines a unique role of Gly238Ser in broad-spectrum β-lactam resistance in this family of class A β-lactamases.
Temperature scaling method for Markov chains.

The use of ab initio potentials in Monte Carlo simulations aimed at investigating the nucleation kinetics of water clusters is complicated by the computational expense of the potential energy determinations. Furthermore, the common desire to investigate the temperature dependence of kinetic properties leads to an urgent need to reduce the expense of performing simulations at many different temperatures. A method is detailed that allows a Markov chain (obtained via Monte Carlo) at one temperature to be scaled to other temperatures of interest without the need to perform additional large simulations. This Markov chain temperature-scaling (TeS) can be generally applied to simulations geared for numerous applications. This paper shows the quality of results which can be obtained by TeS and the possible quantities which may be extracted from scaled Markov chains. Results are obtained for a 1-D analytical potential for which the exact solutions are known. Also, this method is applied to water clusters consistin...
First Report of Downy Mildew on Nursery-Grown Hellebore Caused by Peronospora pulveracea in California.

Hellebore or Lenten rose (Helleborus × hybridus) is an evergreen, herbaceous perennial in the family Ranunculaceae. Hellebores are sold as decorative, potted plants and as shade-loving landscape plants favored for their attractive and prolonged blooms in late winter or early spring. In April of 2008, downy mildew-like growth was observed on the foliage of approximately 60 containerized plants of Helleborus 'Blue Lady', 'Pink Lady', 'White Lady', and 'Royal Heritage' grown outdoors in a retail nursery in coastal San Mateo County, California. Infected foliage had angular, vein-delimited, dark brown-to-black speckled lesions on adaxial leaf surfaces turning dry and necrotic with age. Young leaves were small and distorted. Affected flowers were spotted and brown. The abaxial sides of affected leaves had light brown-to-purplish downy mildew-like growth. Subhyaline conidia, globose to ellipsoid in shape, ranged from 25 to 31 × 17 to 24 μm (average 28 × 21 μm). Conidiophores ranged from 265 to 375 × 5 to 11.5 μm (average 333 × 8.9 μm), branching dichotomously four to five times in the upper half. Morphological measurements fell within the range previously described for Peronospora pulveracea and P. alpicola, which were reported on Helleborus spp. and Ranunculus aconitifolius, respectively (1,2). DNA sequence of the internal transcribed spacer region of rDNA of our isolate (Genbank Accession No. FJ384778) matched sequences of P. pulveracea (Genbank Accession No. AY198270) and P. alpicola (Genbank Accession No. AY198271) with 100% identity. These two organisms are taxonomically indistinguishable by rDNA sequences and are likely to be the same species (3). To our knowledge, this is the first report of P. pulveracea on Helleborus × hybridus in California and the United States. Lenten rose is commercially propagated by seed, which is a potential pathway for introduction of this pathogen. Mature plants are sold and shipped intra- and interstate as decorative flowering plants or nursery stock. The importance and economic impact of this disease is limited, but significant economic losses could occur during production. References: (1) E. A. Gaumann. Beitr. Kryptogamenflora Schweiz 5:113, 1923. (2) G. Hall. Mycopathologia 126:57, 1994. (3) H. Voglmayr. Mycol. Res. 107:1132, 2003.
Study on the tritium behaviors in the VHTR system. Part 2: Analyses on the tritium behaviors in the VHTR/HTSE system ☆

Abstract Tritium behaviors in the very high temperature gas reactor (VHTR)/high temperature steam electrolysis (HTSE) system have been analyzed by the TPAC developed by Idaho National Laboratory (INL). The reference system design and conditions were based on the indirect parallel configuration between a VHTR and a HTSE. The analyses were based on the SOBOL method, a modern uncertainty and sensitivity analyses method using variance decomposition and Monte Carlo method. A total of 14 parameters have been taken into account associated with tritium sources, heat exchangers, purification systems, and temperatures. Two sensitivity indices (first order index and total index) were considered, and 15,360 samples were totally used for solution convergence. As a result, important parameters that affect tritium concentration in the hydrogen product have been identified and quantified with the rankings. Several guidelines and recommendations for reducing modeling uncertainties have been also provided throughout the discussions along with some useful ideas for mitigating tritium contaminations in the hydrogen product.
Mixed‐enhanced formulation for geometrically linear axisymmetric problems

A four-noded quadrilateral axisymmetric formulation in the context of a mixed-enhanced method is presented. The strain field is represented by two sets of element parameters, which results in enhanced performance and coarse mesh accuracy in bending dominated problems and locking-free response in the near incompressible limit. The mixed fields presented are such that variational stress recovery is permissible. In addition, the formulation is cast such that the mixed parameters are obtained explicitly yielding finite element arrays with the proper rank using standard order quadrature. In this paper our attention is restricted to the area of geometrically linear problems in solid mechanics. Representative simulations show favourable performance of the formulation. Copyright © 2002 John Wiley & Sons, Ltd.
A Theoretical Investigation on the Structure of Fan Wakes

An analytical study is presented of the mean and turbulent characteristics of axial turbulent wakes behind a rotating fan. Simplified solutions are presented governing the mean radial and axial velocity profiles and their decay rate. An estimate is made of the relative order of magnitude of various turbulence quantities. The effect of rotation on the turbulence structure is described. Sufficient physical interpretations and explanations are presented for insight into and formulation of the problem.