cssi/SciSciGPT-SciSciNet huggingface dataset:
Resolution-limiting factors in 2-deoxyglucose autoradiography. I. Factors other than diffusion.

Abstract We measured the extent to which factors other than the diffusion of the radioactive label during tissue preparation limits the spatial resolving power of 2-deoxyglucose (2-DG) autoradiography. Radioactive swept frequency gratings were created using microcircuit lithography. The gratings consisted of alternating equal width radioactive and non-radioactive bars in groups of narrowing bar width (effective range 500-20 μm). The vertical thickness of the gratings ranged from 2.25 to 20 μm. The isotope in the radioactive bars was either14C or3H. A variety of X-ray films were exposed to these gratings and the resulting images scanned with microdensitometers or video digitizers to determine the fall oof in image contrast (dark-bar values minus light-bar values) as a function of the number of dark bars (lines) per millimeter. The power of the isotope was the resolution limiting factor. Grating thickness and type of film made little difference. The limit of resolution with14C was 10 lines/mm; with3H, it was 25 lines/mm. The microdensitometer itself is apt to be a resolution limiting factor; the resolving power of those commonly used in autoradiography is unlikely to exceed 10 lines/mm. From measurements of the steepness of gray-matter to white-matter transitions in the image from a tissue section, we conclude that the resolution in the image is no worse than 1.6–3.2 lines/mm. Either the isotope or diffusion of the 2-DG during tissue preparation must be the factor that limits resolution.
The tephra stratigraphy of two lakes in south-central British Columbia, Canada and its implications for mid-late Holocene volcanic activity at Glacier Peak and Mount St. Helens, Washington, USA

Several mid-late Holocene Glacier Peak tephras along with Mazama and Mount St. Helens Wn and P tephras were found in cores from Cooley and Rockslide lakes in southeastern British Columbia, ∼300 km northeast of Glacier Peak. The sediments in Cooley Lake host the late Holocene Glacier Peak A tephra (2010 calibrated (cal) years BP), four separate Glacier Peak Dusty Creek (GPDC) tephras (57805830 cal years BP), and a Glacier Peak set D tephra (6060 cal years BP). This is the first report of Glacier Peak A and D tephras in British Columbia. The A tephra has been correlated on the basis of glass composition and age to a late Holocene Glacier Peak tephra in the sediments of Big Twin Lake, 75 km northeast of Glacier Peak. The glasses in the four GPDC tephra layers from Cooley Lake are compositionally indistinguishable from those in Mount Barr Cirque and Frozen lakes in southwestern British Columbia. The layers likely represent four eruptions taking place over 50 years. Although set D tephra has not been correlat...
Competition and Coexistence among the Grazing Snail Lymnaea, Chironomidae, and Mircrocrustacea in an Arctic Epilithic Lacustrine Community

Effects of the grazing activity of the gastropod Lymnaea elodes (arctica?) on animal community structure in the rocky littoral of an arctic lake were examined. In situ caging experiments on natural substrates with various snail densities resulted in shifts in faunal biomass abundance and distribution. Chironomids living in fixed tubes (Paratanytarsus) were greatly reduced at high snail loads. Free—living scrapers (Corynoneura, Crictopus cf. sylvestris, Zalutschia trigonocies, and others) fared only slightly better, while predators (Arctopelopia and Ablabesmyia) were relatively less sensitive to changes in snail density. Trichoptera larvae, Acari, and copepods were unaffected by the snails. Ostracoda and Cladocera biomass was significantly reduced by Lymnaea. All of the less sensitive groups were relatively more mobile. Reduced algal biomass and chlorophyll concentration were correlated with increased snail densities. Lymnaea production was limited by conspecific density and food. See full-text article at ...
Mechanisms of formation of nitrogen-containing polycyclic aromatic compounds in low-temperature environments of planetary atmospheres: A theoretical study

Polycyclic aromatic hydrocarbons (PAHs) are believed to be responsible for the formation of organic haze layers in Titan's atmosphere, but the nature of PAHs on Titan and their formation and growth mechanisms are not well understood. Considering the high abundance of nitrogen in Titan's atmosphere, it is likely that the haze layers hold not only pure hydrocarbon PAHs but also their nitrogenated analogs, N-containing polycyclic aromatic compounds (N-PACs) with ‘hetero’ N atoms in aromatic rings. Laboratory studies of Titan's tholins also support the hypothesis that, together with pure PAHs and their cations, N-PACs may be the fundamental building blocks of microphysical tholin particles. In the present work, we carried out ab initio quantum chemical calculations of potential energy surfaces for various reaction mechanisms of incorporation of nitrogen atoms into aromatic rings of polycyclic aromatic compounds, which may lead to the formation of N-PACs under the low-temperature and low-pressure conditions of Titan's atmosphere. This includes mechanisms analogous to the Ethynyl Addition Mechanism (EAM) recently proposed by us for the growth of PAH by sequential C2H additions to benzene. We consider consecutive C2H and CN additions to C6H6, C6H6 + CN → C6H5CN + H, C6H5CN + C2H → C6H4(CN)(C2H) + H, C6H5CN + CN → C6H4(CN)2 + H, C6H4(CN)(C2H) + C2H → 2-aza-4-ethynyl-1-naphthyl/2-aza-1-ethynyl-4-naphthyl, C6H4(CN)2 + C2H → C6H4(CN)(NCCCH), and C6H4(CN)(NCCCH) + C2H → 1,4-diethynylphthalazine. Although these reactions are found to be barrierless and exothermic and therefore feasible at low temperatures, the steps leading to the aza-ethynyl-naphthyl radicals, C6H4(CN)(NCCCH), and 1,4-diethynylphthalazine can give N-PACs as final products only upon their collisional or radiational stabilization. Alternatively, an N-PAC can be synthesized via the reaction of 2-methyleneaminobenzonitrile with C2H, producing 4-ethynyl-quinoline + H without an entrance barrier via a three-step sequence including C2H addition to C of CN, ring closure, and H elimination. 2-Methyleneaminobenzonitrile itself can be formed in the reaction of methyleneaminobenzene with cyano radical, C6H5(NCH2) + CN → C6H5(NCH2)(CN) → C6H4(NCH2)(CN) + H, which also does not have any entrance barrier. Methyleneaminobenzene can be produced through recombination of phenyl and methylene-amidogen radicals followed by collisional stabilization of the product, via the barrierless C6H5 + CH3N → C6H5(NCH3) → C6H5(NCH2) + H reaction, or in the reaction of phenyl with methyleneimine, C6H5 + CH2NH → C6H5(NHCH3) → C6H5(NCH2) + H. The latter would be slow at low-temperature conditions owing to the barriers of 4.5 and 2.8 kcal mol−1 relative to the initial reactants, but feasible if the reactants possess sufficient internal energy to overcome these barriers. We anticipate that the presented mechanisms are viable to form N-PACs in hydrocarbon and nitrogen rich, low temperature atmospheres of planets and their moons such as Titan.
Clinical evaluation of an a-amylase assay with insoluble starch labeled with Remazolbrilliant Blue (amylopectin-azure)

Summary 1. A simple, rapid and highly reproducible amylase assay for diagnostic use is presented. 2. The procedure is based on an insoluble starch labeled with Remazolbrilliant Blue which has been reported previously. 3. Detailed methodology and kinetic studies with the new substrate are described. 4. A clinical evaluation of the new method was made by comparing it with two other widely used procedures in concurrent determinations of serum and urinary amylase of normal subjects and patients with acute pancreatitis. 5. Statistical analysis of the results demonstrates the diagnostic validity of the new assay.
Cultivar and Climatic Effects on the Protein Content of Soft White Winter Wheat

High-protein wheats (Triticum aestivum L.) are not preferred for Oriental diets. Because the protein content of soft white winter wheat grown extensively in the U.S. Pacific Northwest is often higher than the optimum (100 g kg −1 ) for export, there has been a decline of wheat exports to Japan and other Pacific Rim countries. The present study was undertaken to examine the trends in protein levels during 1979 to 1988 and to evaluate the influence of wheat cultivars and climatic parameters on protein content of SWW wheat in the Pacific North-west. The maximum and minimum temperatures, precipitation, and evaporation during each of 9 wk prior to crop harvest were tested for their effect on protein content [...]
Observations of Time-dependent Errors in Long-period Instrument Gain at Global Seismic Stations

We present evidence for significant deviations of the true instrument gain from that reported for several modern broad-band permanent seismograph stations. Our result derives from a systematic comparison of observed and synthetic long-period seismograms for approximately 600 large earthquakes. Seismograms were collected from globally distributed stations and analyzed using the centroid-moment-tensor (CMT) algorithm for estimating earthquake parameters. Following the source inversion, synthetic seismograms corresponding to the final earthquake parameters were compared with the observed seismograms and an optimal amplitude-scaling coefficient for each seismogram was determined. Scaling coefficients for earthquakes occurring in a given calendar year were then averaged to investigate the temporal stability of instrument gain. Data for up to 15 years (1990–2004) for more than 200 stations were processed. Most stations show good agreement (±10%) between the observed and reported gains. A small number of stations display a larger constant offset in the gain, probably caused by errors in the reported absolute gain or, potentially, by unmodeled systematic effects resulting from the Earth's lateral heterogeneity. The existence of errors in the reported long-period gain is confirmed through a station-by-station comparison with results from an independent analysis of station-gain bias at similar periods. More than 15 stations display significant reductions in the true long-period gain that occur gradually over several months to a few years. At ∼250-s period, these changes are as large as 50% of the reported gain. The changes are smaller at shorter periods, suggesting a frequency-dependent modification of the instrument response. All of the affected stations showing a time-dependent deterioration are equipped with the Streckeisen STS-1 seismometer, suggesting a common cause for the observed behavior. Modern broad-band observatory seismometers are generally believed to have very stable instrument parameters. Earlier seismological instruments were less stable, with mechanical and electronic systems that tended to drift over time, leading to …
REVERSIBLE DIOXYGEN BINDING TO HEMERYTHRIN. 1. ELECTRONIC STRUCTURES OF DEOXY- AND OXYHEMERYTHRIN

Studies on the electronic structure of the two physiologically relevant forms of hemerythrin (Hr), i.e., deoxyHr (possessing a hydroxo-bridged diferrous site) and oxyHr (having an oxo-bridged diferric site with a terminal hydroperoxide), are presented and discussed. SQUID magnetic susceptibility data for deoxyHr confirm that the two ferrous ions are weakly antiferromagnetically coupled, J = −14(2) cm-1 (ℋ = −2JS1·S2), indicating that at 300 K the entire manifold of ground-state spin sublevels is available for the reaction with O2. From density functional calculations on deoxyHr, evaluated on the basis of experimental data, the redox active orbital on the five-coordinate iron (Fe2) is favorably oriented for a π-bonding interaction with O2 approaching along the open coordination site of that center, and reorientation of the redox active orbital on the six-coordinate iron (Fe1) for electron transfer to O2 through superexchange with Fe2 is energetically accessible. Analysis of existing spectroscopic data for ...
Mediated transfer as a function of associative directionality and meaningfulness of the mediated items

The relative effectiveness of forward and backward associations in mediating paired-associate learning was assessed under conditions where the mediated items were of low or high meaningfulness. Previous results indicating superior mediational effectiveness of forward associations were found to be due primarily to sources of transfer which are independent of mediational processes. However, slightly stronger mediation effects were found in the paradigm involving forward mediated association (A-B, B-C, A-C) than in the paradigm where the mediational effect was due entirely to backward associations (A-B, B-C, C-A). These results were found for both levels of meaningfulness. In addition, stronger mediational effects were found when the mediated items were of high (as compared with low) meaningfulness.
The second filter is real, but how does it work?

The following speculative suggestions are offered informally concerning the “second filter” in the cochlea. Increased sensitivity is an advantage as important as increased sharpness of tuning. These two features and the “cochlear echo” strongly suggest a resonant system with high Q, which would also explain the prolonged latency near threshold of the action potential of the auditory nerve. The viscous damping of a mechanical resonator in the organ of Corti might be overcome by positive feedback. The second filter is mechanically fragile and is vulnerable to anoxia. The source of the energy for positive feedback might be the cochlear microphonic of the outer hair cells. A possible transducer is hyaluronic acid located between the cilia and known to have piezoelectric properties.
Initial-recall grouping in free-recall learning

In the course of a demonstration free-recall learning (FRL) experiment, it was noted that Ss differed markedly in the extent to which they grouped initially recalled words together in subsequent recall periods. Further examination indicated that the degree of such grouping was inversely related to both rate and asymptote of learning. These results were interpreted as the consequence of persisting in the use of an inappropriate encoding and retrieval scheme.
Asymptotic viscoelastic rays in a thick plate

The high frequency behaviour of generalized ray arrivals is discussed with a view towards material characterization by means of measurements of the dispersion of ultrasonic pulses. The effect of beam spreading is treated exactly. Signal processing algorithms are developed. They are demonstrated with a synthetic signal obtained in an elastic material
Self-complexity and psychological distress: A test of the buffering model

Abstract Previous research by Linville (1987) has suggested that an individual's cognitive self-complexity can moderate his or her response to stressful life events. We sought to replicate and extend this finding by testing the ability of three distinct measures of self-complexity (a trait-sort procedure, a repertory grid task, and an analysis of the complexity of a narrative self-description) to function as buffers in a multiple regression model against variations over time in depression, stress, and physical symptoms in 127 college students. The three measures of self-complexity were substantially unrelated either to one another or to a measure of general intelligence. Moreover, results supporting the buffer hypothesis were approximated only when the trait-sort operationalization of self-complexity employed by Linville was used. Clearer confirmation of the buffer hypothesis might be obtained through further prospective studies that measure self-complexity in terms of the number and similarity of self-re...
Establishing a pedagogical framework for the multicultural course in communication sciences and disorders.

Purpose To provide an overview of a model for teaching a foundational course in multicultural (MC) issues and to demonstrate how it can be modified for use in communication sciences and disorders (CSD) by integrating 3 primary dimensions of cultural competence: awareness, knowledge, and skills. Method This tutorial begins by establishing the need for a basic foundational course in MC issues for CSD. Next, the authors describe a framework for MC instruction developed in the field of clinical counseling. Finally, the framework is modified and applied to the implementation of an MC course in CSD. Conclusion The MC course in CSD can provide a useful foundation for facilitating the cultural competence of students in university training programs that have infused MC material across the American Speech-Language-Hearing Association’s 9 content areas.
Symbols for alleles controlling the human ABO blood groups

(1990). Symbols for alleles controlling the human ABO blood groups. Journal of Biological Education: Vol. 24, No. 1, pp. 3-3.
Mechanism for the large conductance modulation in electrolyte-gated thin gold films

Electrolyte gating using ionic liquid electrolytes has recently generated considerable interest as a method to achieve large carrier density modulations in a variety of materials. In noble metal thin films, electrolyte gating results in large changes in sheet resistance. The widely accepted mechanism for these changes is the formation of an electric double layer with a charged layer of ions in the liquid and accumulation or depletion of carriers in the thin film. We report here a different mechanism. In particular, we show using x-ray absorption near edge structure (XANES) that the previously reported large conductance modulation in gold films is due to reversible oxidation and reduction of the surface rather than the charging of an electric double layer. We show that the double layer capacitance accounts for less than 10% of the observed change in transport properties. These results represent a significant step towards understanding the mechanisms involved in electrolyte gating.
Requirement of the Lipopolysaccharide O-Chain Biosynthesis Gene wxocB for Type III Secretion and Virulence of Xanthomonas oryzae pv. Oryzicola

ABSTRACT Xanthomonas oryzae pv. oryzicola causes bacterial leaf streak of rice. A mutant disrupted in wxocB , predicted to encode an enzyme for lipopolysaccharide (LPS) synthesis, was previously shown to suffer reduced virulence. Here, we confirm a role for wxocB in virulence and demonstrate its requirement for LPS O-chain assembly. Structure analysis indicated that wild-type LPS contains a polyrhamnose O chain with irregular, variant residues and a core oligosaccharide identical to that of other Xanthomonas spp. and that the wxocB mutant lacks the O chain. The mutant also showed moderate impairment in exopolysaccharide (EPS) production, but comparison with an EPS-deficient mutant demonstrated that this impairment could not account entirely for the reduced virulence. The wxocB mutant was not detectably different from the wild type in its induction of pathogenesis-related rice genes, type II secretion competence, flagellar motility, or resistance to two phytoalexins or resveratrol, and it was more, not less, resistant to oxidative stress and a third phytoalexin, indicating that none of these properties is involved. The mutant was more sensitive to SDS and to novobiocin, so increased sensitivity to some host-derived antimicrobials cannot be ruled out. However, the mutant showed a marked decrease in type III secretion into plant cells. This was not associated with any change in expression of genes for type III secretion or the ability to attach to plant cells in suspension. Thus, virulence of the wxocB mutant is likely reduced due primarily to a direct, possibly structural, effect of the loss of the O chain on type III delivery of effector proteins.
Influence of environment on the electronic structure of cob(III)alamins : Time-resolved absorption studies of the S1 state spectrum and dynamics

Transient absorption spectroscopy has been used to elucidate the nature of the S1 intermediate state populated following excitation of cob(III)alamin (Cbl(III)) compounds. This state is sensitive both to axial ligation and to solvent polarity. The excited-state lifetime as a function of temperature and solvent environment is used to separate the dynamic and electrostatic influence of the solvent. Two distinct types of excited states are identified, both assigned to π3d configurations. The spectra of both types of excited states are characterized by a red absorption band (ca. 600 nm) assigned to Co 3d → 3d or Co 3d → corrin π* transitions and by visible absorption bands similar to the corrin π→π* transitions observed for ground state Cbl(III) compounds. The excited state observed following excitation of nonalkyl Cbl(III) compounds has an excited-state spectrum characteristic of Cbl(III) molecules with a weakened bond to the axial ligand (Type I). A similar excited-state spectrum is observed for adenosylcob...
Diffusion in sodium mordenite

The rates of diffusion of CH4, nC4H10, iso-C4H10, and C4F10 into well-characterized single crystals of sodium mordenite were studied at 25°C to 100°C., using a rapidly responding constant-volume system. The diffusion coefficients are of the order of 10−8 to 10−9 sq. cm/sec. and exhibit a maximum value with time, probably due to an initial temperature increase caused by the heat of sorption. The implications to catalysis of these and other studies of diffusion in zeolites are discussed.
Bright ultrashort X-rays from intense subpicosecond laser-plasma interactions

Summary form only given. Short-pulse, high-intensity lasers interacting with solid targets make possible the study of a new class of laser-plasma interactions. They are unique because during the ultrashort laser pulse relatively little expansion occurs, and the density scale length remains much less than the laser wavelength. This makes possible the direct deposition of a significant amount of the laser energy at close to solid density. Steep plasma temperature and density gradients subsequently cause rapid cooling, resulting in highly non-equilibrium conditions and the concurrent emission of extremely bright ultrashort X-ray pulses. In this study, the latter are investigated experimentally with temporally and spectrally resolved soft X-ray diagnostics. The emitted X-ray spectra from solid targets with various atomic numbers are characterized for a laser pulse width /spl tau//sub l//spl sim/400 fs. With low contrast (10/sup 5/), the X-ray spectrum in the /spl lambda/=40-100 /spl Aring/ spectral region is dominated by line emission, and the X-ray pulse duration is found to be characteristic of a long-scale-length, low-density plasma. Bright, picosecond, broadband emission, characteristic of a short-scale-length, high-density plasma, is produced only when a high laser contrast (10/sup 10/) is used. It is demonstrated experimentally that the pulse width of laser-produced X-ray radiation may be varied down to the picosecond time scale by adjusting the incident ultrashort-pulse laser flux.
Dietary Acculturation and Predictors of Anthropometric Indicators Among Filipino Americans

The aim of this study was to explore the relationship of the demographic variables, level of acculturation, dietary consumption of fat, sugar, fruits and vegetables and dietary acculturation to the anthropometric measurement of Filipino Americans (FAs) in the United States. The study sample consisted of 128 FAs (N = 128) residing in the southeastern part of the United States. Participants completed the demographics, the Block’s Short Food Frequency Questionnaire (SFFQ), a Short Acculturation Scale for Filipino Americans (ASASFA), and the Dietary Acculturation Questionnaire for Filipino Americans (DAQFA). Anthropometric measurements (waist circumference, hip circumference, weight, and height) were also taken. Descriptive statistics analyses and partial least squares (PLS) were used to explore the predictive relationships among the variables constructed. The most important positive predictors of the anthropometric indicators were the Western Scale (path coefficient = .503, p < .05) and the intake of fats and sugars (path coefficient = .282, p < .05).
Principled parsing for indentation-sensitive languages: revisiting landin's offside rule

Several popular languages, such as Haskell, Python, and F#, use the indentation and layout of code as part of their syntax. Because context-free grammars cannot express the rules of indentation, parsers for these languages currently use ad hoc techniques to handle layout. These techniques tend to be low-level and operational in nature and forgo the advantages of more declarative specifications like context-free grammars. For example, they are often coded by hand instead of being generated by a parser generator.This paper presents a simple extension to context-free grammars that can express these layout rules, and derives GLR and LR(k) algorithms for parsing these grammars. These grammars are easy to write and can be parsed efficiently. Examples for several languages are presented, as are benchmarks showing the practical efficiency of these algorithms.
Discriminative training of variable-parameter HMMs for noise robust speech recognition.

We propose a new type of variable-parameter hidden Markov model (VPHMM) whose mean and variance parameters vary each as a continuous function of additional environmentdependent parameters. Different from the polynomialfunction-based VPHMM proposed by Cui and Gong (2007), the new VPHMM uses cubic splines to represent the dependency of the means and variances of Gaussian mixtures on the environment parameters. Importantly, the new model no longer requires quantization in estimating the model parameters and it supports parameter sharing and instantaneous conditioning parameters directly. We develop and describe a growth-transformation algorithm that discriminatively learns the parameters in our cubic-splinebased VPHMM (CS-VPHMM), and evaluate the model on the Aurora-3 corpus with our recently developed MFCCMMSE noise suppressor applied. Our experiments show that the proposed CS-VPHMM outperforms the discriminatively trained and maximum-likelihood trained conventional HMMs with relative word error rate (WER) reduction of 14% and 20% respectively under the well-matched conditions when both mean and variances are updated. Index Terms: speech recognition, variable-parameter hidden Markov model, discriminative training, cubic spline, growth transformation
Rationale For Surface Extraction From Solid Three Dimensional Volume Images

In many clinical fields (e.g. craniofacial surgery), the subject of interest is the surface of only one type of body tissue. Volume images of the overlying soft tissue merely obscure the subject. Further in surgical simulation programs used in these disciplines, interactivity is of paramount importance. The relative simplicity of the surface image makes real time image generation more tractable. Further surface normal calculations may be combined with a good lighting model for extremely realistic images. Surface extractions are a requirement for statistical comparisons of volume images with a normative data set.
Estimation of spectral reflectance curves from multispectral image data

A technique is presented for estimating spectral reflectance curves from multispectral image data even if the spectral samples are obtained from channels whose spectral responsivity is not narrowband. It is demonstrated that these reflectance estimates can be written as a linear combination of the spectral samples and that, analogous to Shannon's sampling theorem, if the spectral reflectance is a natural cubic spline, it can be estimated exactly provided the number of spectral channels is sufficiently large. Simulation results suggest that the accuracy of the spectral reflectance estimates is quite good and very insensitive to the spectral responsivity shapes.
Drawing crowds and bit welfare

Tit-for-tat style file sharing systems such as BitTorrent have proven to be remarkably effective in dealing with highly popular content. By explicitly addressing free-riding behavior, a "greedy" tit-for-tat approach encourages sharing and succeeds in providing a higher quality of service. However, in situations where a file is not as popular, or the rate of demand is not high, it is frequently difficult to obtain the file in a timely manner. In this paper we demonstrate how additionally greedy behavior on the part of some peers can counterintuitively address this problem. In particular we discuss two possible techniques by which peers, with complete file copies, strategically reduce their effort while improving total network performance by various metrics.
Bayesian tactile face

Computer users with visual impairment cannot access the rich graphical contents in print or digital media unless relying on visual-to-tactile conversion, which is done primarily by human specialists. Automated approaches to this conversion are an emerging research field, in which currently only simple graphics such as diagrams are handled. This paper proposes a systematic method for automatically converting a human portrait image into its tactile form. We model the face based on deformable active shape model (ASM) (Cootes et al., 1995), which is enriched by local appearance models in terms of gradient profiles along the shape. The generic face model including the appearance components is learnt from a set of training face images. Given a new portrait image, the prior model is updated through Bayesian inference. To facilitate the incorporation of a pose-dependent appearance model, we propose a statistical sampling scheme for the inference task. Furthermore, to compensate for the simplicity of the face model, edge segments of a given image are used to enrich the basic face model in generating the final tactile printout. Experiments are designed to evaluate the performance of the proposed method.
Structure and Significance of Planar Deformation Features in Synthetic Quartz

Creep tests were performed on three polished cylinders of synthetic quartz stressed normal to(10l). Observations of slip bands in reflected light, orientations of planar deformation features on a universal stage, and dislocation structures of these features on a transmission electron microscope are used to deduce slip mechanisms and deformation structures. Experimental conditions of temperature, pressure, and stress were 600° and 800°C, 3 kb, and between 1.3 and 7 kb. Slip band data imply the operation of thejbllowing slip systems (100)[ c ], (011)[ a i ],(012)[ a 1 ],(101)[ a 3 ], (102) [ a 3 ], and possibly (112). Two sets of planar deformation features are developed, which are termed laminas and lamellas. Laminas are dense tangles of dislocations subparallel to (0001), probably caused by interference between minor slip on (0001) and slip on (101) and (112). Lamellas form subparallel to the major slip planes. Those near (100) comprise dense associations of dislocations generally parallel to [ a 2 ]. They are probably edge dislocations and are of undetermined sign. The observations support the model of Christie and others (1964) that explains the optical properties of such features.
Development of an underwater robot, ODIN-III

During the last decade, the first autonomous underwater robot of the Autonomous Systems Laboratory of the University of Hawaii, ODIN (Omni-Directional Intelligent Navigator) built in 1991 has produced a lot of valuable results in development and control methods [(S.K. Choi et al., July 1994), (Choi, S.K. et al., March 1995), (S.K. Choi et al., April 1996), (Yang, K.C. et al., September 1999), (J. Yuh et al., 2000)]. Recently, ODIN was born again in the 3rd generation with unique features under recent technologies such as abundant system resources owing to a PC104+, new vehicle system software architectures with an object-oriented concept and its implementation, a graphical user interface and an independent algorithm module using a dynamic linking library (DLL) based on the Windows operating system. These give us an ideal environment for developing various algorithms which are needed for developing an advanced underwater robotic vehicle. This paper describes details of the development of ODIN-III and presents initial experimental results for fine motion control.
A Pilot Study of Core Topics in Introductory Social Psychology and Developmental Psychology Textbooks

This study examined the similarities and differences in the topics and references in selected chapters of eight introductory social psychology textbooks and six developmental psychology textbooks. We wanted to determine the extent to which there were core concepts and references presented in these chapters. We found a relatively small set of core topics and references in all of the selected chapters, indicating a lack of consensus among textbook authors as to the core concepts and references in the topic areas. These findings have implications for scholarly agreement about the knowledge base of psychology and the assessment of it.
Heracles: improving resource efficiency at scale

User-facing, latency-sensitive services, such as websearch, underutilize their computing resources during daily periods of low traffic. Reusing those resources for other tasks is rarely done in production services since the contention for shared resources can cause latency spikes that violate the service-level objectives of latency-sensitive tasks. The resulting under-utilization hurts both the affordability and energy-efficiency of large-scale datacenters. With technology scaling slowing down, it becomes important to address this opportunity. We present Heracles, a feedback-based controller that enables the safe colocation of best-effort tasks alongside a latency-critical service. Heracles dynamically manages multiple hardware and software isolation mechanisms, such as CPU, memory, and network isolation, to ensure that the latency-sensitive job meets latency targets while maximizing the resources given to best-effort tasks. We evaluate Heracles using production latency-critical and batch workloads from Google and demonstrate average server utilizations of 90% without latency violations across all the load and colocation scenarios that we evaluated.
A study of the kinetics of the reduction of neptunium(VI) by acetohydroxamic acid in perchloric acid

The kinetics of reduction of NpO22+ to NpO2+ by acetohydroxamic acid in 1 mol?L?1perchloric acid media at 10 and 22?C were studied. The reaction rate was monitored using stopped-flow and standard infrared spectroscopy. Under conditions such that acetohydroxamic acid was in excess relative to Np, the reduction rate of NpO22+ is described by the following: where k = 2.57x103 mol?1?L?sec?1 at 10?C. However, when neptunium is in a significant molar excess relative to acetohydroxamic acid, the reduction mechanism is dictated by two distinct reactions. An initial and incomplete reduction occurs as the result of the oxidation of AHA, while a slower and partial reduction of NpO22+ is likely caused by the oxidation products of AHA. The reaction rate of this first-order mechanism was calculated as 3.7x10?4 sec?1 at 10?C and 0.001 sec?1 at 22?C.
Autoradiographic and small-animal PET comparisons between 18F-FMISO, 18F-FDG, 18F-FLT and the hypoxic selective 64Cu-ATSM in a rodent model of cancer

Abstract Introduction Copper(II)-diacetyl-bis( N 4 -methylthiosemicarbazone), or Cu-ATSM, a hypoxia imaging agent, has been shown to be predictive of response to traditional cancer therapies in patients with a wide range of tumors. It is known that the environment of the tumor results in a myriad of physiological consequences, including hypoxia, alterations in metabolism and proliferation. In an effort to better characterize the relationships between Cu-ATSM and other prominent radiopharmaceuticals, this current study was undertaken to compare the regional distribution of 64 Cu-ATSM with [ 18 F]fluoromisonidazole ( 18 F-FMISO), [ 18 F]fluoro-2-deoxy-d-glucose ( 18 F-FDG) and [ 18 F]fluorothymidine ( 18 F-FLT) in 9L tumors. Methods Taking advantage of the different half-life of 18 F ( t 1/2 =110 min) in comparison to 64 Cu ( t 1/2 =12.7 h), we undertook a dual-tracer autoradiography study in 9L tumors. Four groups were examined: (a) 18 F-FMISO, 2 h postinjection (p.i.) and 64 Cu-ATSM, 10 min p.i.; (b) 18 F-FMISO, 2 h p.i. and 64 Cu-ATSM, 24 h p.i.; (c) 18 F-FDG, 1 h p.i. and 64 Cu-ATSM, 10 min p.i.; and (d) 18 F-FLT, 1 h p.i. and 64 Cu-ATSM, 10 min p.i. Small-animal PET imaging was performed in 9L tumor-bearing rats with imaging on concurrent days comparing 64 Cu-ATSM with 18 F-FMISO and 18 F-FLT. Results It was shown that the regional distribution of 18 F-FMISO and 64 Cu-ATSM showed an excellent correlation when the 64 Cu-ATSM had been allowed to distribute for either 10 min ( R 2 =.84) or 24 h ( R 2 =.86). The regional comparisons between 64 Cu-ATSM (10 min) and 18 F-FDG (1 h) resulted in a very poor correlation ( R 2 =.08) between the regional uptake of the two agents. The comparison between 18 F-FLT and 64 Cu-ATSM showed a strong relationship ( R 2 =.83) between the two tracers. The small-animal PET images for the distribution comparisons between 64 Cu-ATSM and 18 F-FMISO and 18 F-FLT were in agreement with the data generated from the autoradiography studies. Conclusions The data show that it is important to remember that a number of different metabolic situations can exist when considering the relationship between regions of high glucose uptake, proliferation and hypoxia.
Fabrication of permeable tubular constructs from chemically modified chitosan with enhanced antithrombogenic property.

The failure of artificial vascular grafts in small diameter vessel replacement is mainly due to the early formation of thrombosis. To prevent the occurrence of thrombosis, much effort has been focused on developing an anti-thrombogenic coating of synthetic vascular prostheses or artificial conduits with improved anti-thrombogenic properties. Because surface coatings may be unstable for long-term applications, a bulk material with anti-thrombogenic property is desirable for the fabrication of vascular grafts or conduits. To this end, we have chemically modified chitosan by phthalization to derive an anti-thrombogenic material for the fabrication of vascular grafts. The chemical structure of phthalized chitosan was characterized with infrared spectroscopy. The hydrophilicity was examined with contact angle measurement, and the molecular weight distribution was measured using gel permeation chromatography (GPC). Protein adsorption, hemolysis, and platelet adhesion assays were used to confirm the enhanced anti-thrombogenic properties of this phthalized chitosan. Cytotoxicity and proliferation assays were performed to test its high biocompatibility. With its improved solubility and processibility, this phthalized chitosan was fabricated into selective permeable tubular constructs of varying sizes and morphology through a wet phase-inversion process. With improved anti-thrombogenic property, biocompatibility, and great processibility, phthalized chitosan has great potential as the material for the fabrication of small diameter vascular grafts. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
A novel leucine zipper targets AKAP15 and cyclic AMP-dependent protein kinase to the C terminus of the skeletal muscle Ca2+ channel and modulates its function.

In skeletal muscle, voltage-dependent potentiation of L-type Ca2+ channel (CaV1.1) activity requires phosphorylation by cyclic AMP-dependent protein kinase (PKA) anchored via an A kinase-anchoring protein (AKAP15). However, the mechanism by which AKAP15 targets PKA to L-type Ca2+ channels has not been elucidated. Here we report that AKAP15 directly interacts with the C-terminal domain of the α1 subunit of CaV1.1 via a leucine zipper (LZ) motif. Disruption of the LZ interaction effectively inhibits voltage-dependent potentiation of L-type Ca2+ channels in skeletal muscle cells. Our results reveal a novel mechanism whereby anchoring of PKA to Ca2+channels via LZ interactions ensures rapid and efficient phosphorylation of Ca2+ channels in response to local signals such as cAMP and depolarization.
A Presynaptic Voltage Clamp Study in the Squid Stellate Ganglion

The importance of extracellular calcium in synaptic transmission was first recognized by Locke (29) in 1894. Working with a frog nerve-muscle preparation, he observed that if calcium was removed from the bathing medium, stimulation of the nerve did not elicit muscle contraction, although the muscle did contract when stimulated directly. Addition of calcium to the bathing medium restored the effectiveness of nerve stimulation. More recently, further work with the neuromuscular junction has elucidated the role of calcium in synaptic transmission (cf. 9). This work established the effective location (calcium must be present at the site of the junction itself) (7,10,11) and the timing (calcium must be present immediately before or during nerve stimulation) (13) of the calcium action.
Constructing the Digitalized Sporting Body Black and White Masculinity in NBA/NHL Internet Memes

In this article, I examine the ways sport fans construct and circulate discourses of race and masculinity in cyberspace. I do this through an examination of a set of Internet memes that juxtapose the bodies of National Hockey League players with National Basketball Association players in one single image. I argue these memes celebrate White masculinity, while at the same time constructing African American athletes as individualistic, selfish, and unwilling to sacrifice their bodies for the greater good of the team. More so, I argue that these memes construct a form of racial ideology that is representative of White backlash politics.
The Renaissance Road: Redesigning the Legal Writing Instructional Model

The status quo in the required legal writing curriculum of legal education is a two-semester program in the first year of law school. However, this program requires that students simultaneously rethink and develop their legal writing skills while being taught an entirely new language. This program expects mastery from all students without accounting for their necessary rebirths or providing multiple opportunities for depth on various assignments. By contrast, institutions can rethink how they educate future lawyers and transition to a three semester program, which allows more opportunity for growth and vertical advancement beyond the standard curriculum. Starting by an analysis of the two-semester model, the article discusses the pedagogical value in transitioning to a three-semester system. The article also compares three-semester programs at various institutions, draws conclusions regarding which elements of a three-semester program should be in an ideal program, and makes recommendations for how an institution can redesign its program's structure and content.
Evaluation of MRI protocols for the assessment of lumbar facet joints after MR-guided focused ultrasound treatment

MR-guided focused ultrasound (MRgFUS) might be a very safe and effective minimally invasive technique to treat facet joint pain caused by arthritis and other degenerative changes. However, there are still safety concerns for this treatment and challenges regarding MR imaging and temperature mapping due to susceptibility effects between the bone and soft tissue near the joint, which has resulted in poor MR image quality. The goal of this research was to evaluate multiple magnetic resonance imaging (MRI) pulse sequences for characterizing ablated lumbar facet joint lesions created by high-intensity focused ultrasound (FUS) and compare the findings to histological tissue assessment. In particular, we investigated the use of T2-weighted MRI to assess treatment effects without contrast administration. An IACUC approved study (n = 6 pigs) was performed using a 3T widebore MRI system equipped with an MRgFUS system. Facet joints of the lumbar vertebra were ablated using 1-MHz frequency and multiple sonication energies (300–800 J). In addition to T2-weighted MRI for treatment planning, T1-, T2-, and T2*-weighted and perfusion MRI sequences were applied. Signal intensity ratios of the lesions were determined. Histopathology was used to characterize cellular changes. Ablation of the facet joint, using MRgFUS, was successful in all animals. T2-weighted images showed high signal intensity in the edematous facet joint and adjacent muscle, while delayed contrast-enhanced T1-weighted images showed an enhanced ring surrounding the target volume. T2*-weighted GRE images revealed inconsistent lesion visualization. Histopathology confirmed the presence of cellular coagulation (shrinkage), extracellular expansion (edema), and hemorrhage in the bone marrow. MRgFUS provided sufficient precision and image quality for visualization and characterization of ablated facet joints directly after ablation. MRI may help in monitoring the efficacy of FUS ablation without contrast after treating patients with back pain.
Comparison of Endothelial Function in Asian Indians Versus Caucasians.

Abstract Background: Asian Indians have markedly increased mortality due to coronary artery disease (CAD). Impaired endothelial function has been linked to an increased risk of acute cardiovascular events. We tested the hypothesis that endothelial function was attenuated in Asian Indians and Caucasians. Methods: We studied 14 Asian Indians [mean age: 30 ± 6 years; mean body mass index (BMI): 25 ± 3 kg/m2] and 11 Caucasians (mean age: 30 ± 5 years; mean BMI: 26 ± 2 kg/m2). All 25 subjects were healthy men and nonsmokers without any history of CAD or diabetes and were not taking medications. Endothelial function was evaluated by ultrasound measures of flow-mediated dilatation (FMD) and endothelium-independent nonflow mediated vasodilatation (NFMD) of the brachial artery, in the morning immediately after awakening (6 a.m.) in a fasting state. Results: Mean age, BMI, apnea–hypopnea index, heart rate, and blood pressure were similar in both groups (P = >0.05). When correcting for body surface area, brachial ar...
Pathological fractures of the spine. Etiology and diagnosis. A review of one hundred and five cases.

The records were reviewed of 162 patients who had been admitted to the Hospital for Special Surgery since 1950 with compression fractures of the spine and demineralization. Fifty-seven of the patients were excluded from this study because the diagnosis was known at the time of admission, adequate trauma to cause fracture had occurred, or the diagnostic study or follow-up had been inadequate. In the remaining 105 patients, osteoporosis was thought to be responsible for the vertebral collapse in fifty-five patients, malignant bone disease in twenty-five, hypercorticism with rheumatoid arthritis in nine, and osteomalacia in six patients. Other conditions were responsible for vertebral collapse in ten patients. The chances of a patient having primary or metastatic malignant bone disease were markedly increased if fewer than three vertebrae were collapsed and the patient was less than fifty-five years of age. In the younger-age group especially, a variety of unusual conditions other than osteoporosis produced the demineralization. In order to make a final diagnosis, complete and, often, repeated studies are necessary. It is important to establish an exact diagnosis since some conditions that produce vertebral collapse respond to specific treatment.
Accelerated disulfide reduction with polyunsaturated fatty acids: a mechanism of ionic channel modulation?

Polyunsaturated fatty acids (PUFAs) have been shown to modulate the activity of ionic channels by an unknown mechanism. Some channels are activated (i.e. certain delayed-rectifier, potassium channels) and others are inhibited (i.e. certain calcium, sodium and other potassium channels). We have previously demonstrated that PUFAs can act as electron carriers. It is known that ionic channels can be redox modulated. The ability of fatty acids to serve as electron shuttling agents is proportional to their unsaturation. These PUFAs cause reduction of disulfides through a superoxide radical-independent mechanism, probably related to enhanced electron delocalization. The present study shows that there is a strong correlation between the ability of a PUFA to transfer an electron to a disulfide and its reported ability to modulate ionic channels. This suggests that electron transfer could be the mechanism of PUFAs action on particular ionic channels.