cssi/SciSciGPT-SciSciNet huggingface dataset:
Flexibility of superstructures and supports in the seismic analysis of simple bridges

This paper addresses the elastic dynamic response of simply supported bridges to ground motion in their transverse direction. The interaction between superstructure and support flexibilities is studied in a systematic manner for symmetric spans. The bridges are modelled as beams with uniformly distributed mass and elasticity, simply supported at the ends by elastic springs. It is shown that a dimensionless stiffness index, which reflects the relative stiffness of the superstructure compared to the stiffness of the substructure, completely defines the dynamic mode shapes of the model. Useful closed-form expressions, based on approximate shape functions, are derived for the dynamic parameters of the first mode, and their accuracy is assessed. The effect of the stiffness index on these dynamic parameters is investigated. Numerical case studies are presented to illustrate the use of proposed equations in the seismic analysis of bridges. Copyright © 2000 John Wiley & Sons, Ltd.
Excretion of Nitrogen by Leguminous Plants

SINCE 1927. Virtanen and co-workers1 have published results of numerous experiments which confirm and greatly extend the observation of Lipman2 that certain leguminous plants when fixing nitrogen excrete part of this into the quartz sand subtrate, and if a non-leguminous plant is present, it may utilize the excreted form. The extensive data Compiled by Virtanen and collaborators prove definitely that true excretion occurs with several of the legumes, but there exists an equally impressive body of experimental data which demonstrates conclusively that excretion is not universally obtained.
The Participation of Two Rhythms in the Leaf Movements of Xanthium Plants Given Various Light-Dark Cycles

We have shown Xanthium strumarium exhibit two distinct leaf movement rhythms with one occurring in continuous light and presumably related to an endogenous rhythm initiated by the “light-on” signal and the other occurring in continuous dark and presumably related to an endogenous rhythm initiated by the “light-off” signal. Characteristic of the light-on rhythm is a sudden and rapid downward movement of the leaf occurring about 16 hours after the light-on signal. Characteristic of the light-off rhythm is an immediate and sudden upward movement following the light-off signal. Under certain photoperiodic treatments, the two movements seem to be in conflict. The characteristic light-on downward movement was predominant in the light-dark 14: 10 and 16: 8 treatments while the light-off upward movement was predominant in light-dark 8: 16 and 10: 14 treatments. In the light-dark 12: 12 treatment, one movement was predominant in about half of the cases and vice versa . Thus leaf movements of X. strumarium plants given these light-dark treatments were found to fit a hypothesis based on the participation of both a light-on and a light-off rhythm. The over-all leaf movement rhythm may be controlled by what might be called two clocks. Both of these clocks may have essentially the same basic mechanism with one important distinction. One is rephased by the light-on signal and the other by the light-off signal. Furthermore, the leaf movements related to each clock are distinctive. The hypothesis of the participation of a light-on and a light-off rhythm was also found to be applicable to published data (M. Holdsworth, 1959. Effects of day length on the movements of pulvinate leaves. New Phytol. 58: 29-45). Interpretation of the Bauhinia leaf movements along this line is also presented.
Initiation, growth, and mitigation of UV-laser-induced damage in fused silica

Laser damage of large fused silica optics initiates at imperfections. Possible initiation mechanisms are considered. We demonstrate that a model based on nanoparticle explosions is consistent with the observed initiation craters. Possible mechanisms for growth upon subsequent laser irradiation, including material modification and laser intensification, are discussed. Large aperture experiments indicate an exponential increase in damage size with number of laser shots. Physical processes associated with this growth and a qualitative explanation of self-accelerated growth is presented. Rapid growth necessitates damage growth mitigation techniques. Several possible mitigation techniques are mentioned, with special emphasis on CO2 processing. Analysis of material evaporation, crack healing, and thermally induced stress are presented.
Structural Bases Supporting the Critical Role of the CRAC Motif Nearest to the N-End of Slo1 Cytosolic C-Tail in Determining the BK Channel Sensitivity to Membrane Cholesterol

We demonstrated that the CRAC domain nearest the N-end of BK channel-forming cbv1 subunits (CRAC4) is the main region that provides cholesterol (CLR) sensitivity to cbv1, the signature CRAC4 Y450 being critical. Here we combined amino acid substitutions in CRAC4, bilayer electrophysiology, and computational dynamics to advance structural bases of CRAC4-CLR interactions. First, trcbv1-CRAC4 constructs including V444A or K453A were insensitive to CLR. Second, trcbv1-CRAC4 K453R retained CLR sensitivity. Third, trcbv1-CRAC4 Y450F was CLR-resistant. However, Y429F in the S6-CRAC4 linker rendered CLR-sensitive channels. Therefore, CLR sensitivity of trcbv1-CRAC4 is determined by the key residues that define a CRAC motif (Epand, 2006). Moreover, the substitution Y450F in CRAC4 was sufficient to blunt the CLR sensitivity of full-length BK channels. Computational simulations of full-length cbv1 CTD and trcbv1 CTD-CRAC4 showed CLR remaining in CRAC4 for the majority of the simulation with CLR D ring near Y450 for over one-third of the simulation. CLR A ring resided predominantly near E417, which hydrogen bonded with CRAC4 through the Y450 hydroxyl, also indicating that CLR stayed close to CRAC4. Conversely, the highest residence for trcbv1 CTD-CRAC4 Y450F was for CLR D ring and tail, which remained near H409 and Y336, respectively, neither of which are part of CRAC4. Notably higher mobility of positions 450 and K453 in CRAC4 were also noted in the simulations of trcbv1-CRAC4 Y450F, indicating that a stable interaction site for CLR is lacking when the Y450 hydroxyl is not present to hydrogen bond to E417. Data provide a structural interpretation for the prominence of CRAC4 and its Y450 in providing CLR-sensitivity to trcbv1-CRAC4 and full-length BK channels. Support: R01-HL104631;R37-AA011560 (AMD); UTHSC NI Fellowship (AKS).
Statistical shape model for manifold regularization: Gleason grading of prostate histology

Gleason patterns of prostate cancer histopathology, characterized primarily by morphological and architectural attributes of histological structures (glands and nuclei), have been found to be highly correlated with disease aggressiveness and patient outcome. Gleason patterns 4 and 5 are highly correlated with more aggressive disease and poorer patient outcome, while Gleason patterns 1-3 tend to reflect more favorable patient outcome. Because Gleason grading is done manually by a pathologist visually examining glass (or digital) slides subtle morphologic and architectural differences of histological attributes, in addition to other factors, may result in grading errors and hence cause high inter-observer variability. Recently some researchers have proposed computerized decision support systems to automatically grade Gleason patterns by using features pertaining to nuclear architecture, gland morphology, as well as tissue texture. Automated characterization of gland morphology has been shown to distinguish between intermediate Gleason patterns 3 and 4 with high accuracy. Manifold learning (ML) schemes attempt to generate a low dimensional manifold representation of a higher dimensional feature space while simultaneously preserving nonlinear relationships between object instances. Classification can then be performed in the low dimensional space with high accuracy. However ML is sensitive to the samples contained in the dataset; changes in the dataset may alter the manifold structure. In this paper we present a manifold regularization technique to constrain the low dimensional manifold to a specific range of possible manifold shapes, the range being determined via a statistical shape model of manifolds (SSMM). In this work we demonstrate applications of the SSMM in (1) identifying samples on the manifold which contain noise, defined as those samples which deviate from the SSMM, and (2) accurate out-of-sample extrapolation (OSE) of newly acquired samples onto a manifold constrained by the SSMM. We demonstrate these applications of the SSMM in the context of distinguish between Gleason patterns 3 and 4 using glandular morphologic features in a prostate histopathology dataset of 58 patient studies. Identifying and eliminating noisy samples from the manifold via the SSMM results in a statistically significant improvement in area under the receiver operator characteristic curve (AUC), 0.832+/-0.048 with removal of noisy samples compared to a AUC of 0.779+/-0.075 without removal of samples. The use of the SSMM for OSE of newly acquired glands also shows statistically significant improvement in AUC, 0.834+/-0.051 with the SSMM compared to 0.779+/-0.054 without the SSMM. Similar results were observed for the synthetic Swiss Roll and Helix datasets.
Search for a light Higgs

Abstract In this talk we discuss the theoretical and experimental constraints on a Higgs boson with mass less than one GeV. We discuss the lifetime, branching ratio and production mechanisms for such a Higgs boson. Note that the expected lifetime and decay branching ratios of the Higgs boson depend crucially on its mass. We focus on the model dependence of these constraints.
Marital Instability Among Mexican Americans: Following the Patterns of Blacks?

While existing literature repeatedly states that rates of marital instability are low among Mexican Americans, data from the 1960 Census suggest otherwise. Furthermore, a comparison of subgroups defined by generation and place of residence indicates a trend toward rapidly increasing rates of marital instability for this population. Third-generation Mexican Americans living in California, the most rapidly growing segment of the minority, have a level of marital instability closely resembling that of blacks. As among blacks, the inability of many Mexican American males to adequately provide for their families at the level they deem necessary, due to low wages and widespread unemployment, appears to be an important source of marital strain. While increasing marital instability may be viewed as an adaptation to their currently deprived circumstances, it is also possible that this may hinder the group's future economic advancement.
Semivacancy pair in crystalline silicon

Abstract A split configuration for the monovacancy in silicon, the semivacancy pair, is proposed. It is argued that the previously proposed ‘divacancy’ should be reidentified as the semivacancy pair, and that it is this defect which is responsible for the diffusion of substitutional atoms in silicon.
TRANSPARENT CARBON NANOTUBE/POLY (3, 4‐ETHYLENEDIOXYTHIOPHENE) COMPOSITE ELECTRICAL CONDUCTORS

A highly stable and processable aqueous dispersion of multi‐wall carbon nanotube/poly (3, 4‐ethylenedioxythiophene) composite was synthesized through the polymerization of 3, 4‐ehtylenedioxythiophene on the surfaces of polystyrene sulfonic acid dispersed carbon nanotubes. Transparent and conductive composite thin films were built on both glass and poly (ethylene terephthalate) substrates through spin‐coating. The composite thin films show low surface resistance with uniform and high transmittance in the visible light range. Furthermore, the surface resistance can be tuned by changing carbon nanotube content in the composite for different technical applications.
Surface Orientation of Magainin 2: Molecular Dynamics Simulation and Sum Frequency Generation Vibrational Spectroscopic Studies

We combined molecular dynamics based free energy calculations with sum frequency generation (SFG) spectroscopy to study the orientational distribution of solvated peptides near hydrophobic surfaces. Using a simplified atomistic model of the polystyrene (PS) surface, molecular dynamics simulations have been applied to compute the orientational probability of an α-helical peptide, magainin 2, with respect to the PS/water interface. Free energy calculations revealed that the preferred (horizontal) peptide orientation was driven by the favorable interactions between the hydrophobic PS surface and the hydrophobic residues on the helix, and additional simulations examined the importance of small aggregate formation. Concentration-dependent measurements obtained via SFG vibrational spectroscopy suggest that, at very low peptide concentrations, magainin molecules tend to lie down at the PS/solution interface, which correlates well with the simulation results. When the concentration is increased, peptides exhibit behavior not captured by MD simulations using single helical peptides. A combination of simulations and experiments was shown to yield more reliable results with molecular-level insights into interaction between peptides and polymer surfaces.
MEMS performance challenges: packaging and shock tests

This paper describes recent advances in the MEMS performance challenges with emphases on packaging and shock tests. In the packaging area, metal to metal bonding processes have been developed to overcome limitations of the glass frit bonding by means of two specific methods: (1) pre-reflow of solder for enhanced bonding adhesion, and (2) the insertion of thin metal layer between parent metal bonding materials. In the shock test area, multiscale analysis for a MEMS package system has been developed with experimental verifications to investigate dynamic responses under drop-shock tests. Structural deformation and stress distribution data are extracted and predicted for device fracture and in-operation stiction analyses for micro mechanical components in various MEMS sensors, including accelerometers and gyroscopes.
A nonstandard proof of a lemma from constructive measure theory

Suppose that fn is a sequence of nonnegative functions with compact support on a locally compact metric space, that T is a nonnegative linear functional, and that T fn < T f0. A result of Bishop, foundational to a constructive theory of functional analysis, asserts the existence of a point x such that fn (x) < f0(x). This paper extends this result to arbitrary Hausdorff spaces, and gives short proofs using nonstandard analysis. While such arguments used are not themselves constructive, they can illuminate where the difficulty lies in finding the point x. An algorithm for constructing x is then given, with a nonstandard proof that the algorithm converges to a correct value. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Collaborative Interaction Behavior in the Era of Open Science Movement

The open science movement has resulted in the post-publication peer-review (PPPR) model that creates a new type of scientific collaboration, in which the authors, the reviewers, and the registered users, share information and shape scientific findings. A new research area is needed to understand collaborative information behaviors in this context and to identify new features needed to design effective PPPR platforms and information retrieval systems (IRs). This paper reports on the preliminary analysis of collaborative interaction behavior (CIB) in open peer-review context. We also suggested special features for IR.
Some evidence for the existence of the liquid‐liquid transition: Melt rheology studies

In 1963 Boyer proposed the existence of a liquid-liquid transition, Tll, in polystyrene above the glass transition Tg. Since that time there has been considerable discussion and disagreement on the existence of this transition. Detailed shear modulus data as a function of temperature in the range 165–215°C will be presented for a series of polystyrenes of various molecular weights. In each case, as the temperature is increased, the modulus gradually decreases until a specific molecular weight dependent temperature is reached and then suddenly the modulus decreases rapidly over a few °C and then returns to its previous gradual decrease with increasing temperature. The response is reminiscent of the modulus behavior going through Tg. It is suggested that the temperature at which this sharp decreased in modulus takes place is Tll. The molecular weight effects on Tll will be discussed in terms of several rheological properties that measure the temperature of this transition.
Using DISE to protect return addresses from attack

Stack-smashing by buffer overflow is a common tactic used by viruses and worms to crash or hijack systems. Exploiting a bounds-unchecked copy into a stack buffer, an attacker can---by supplying a specially-crafted and unexpectedly long input---overwrite a stored return address and trigger the execution of code of her choosing. In this paper, we propose to protect code from this common form of attack using dynamic instruction stream editing (DISE), a previously proposed hardware mechanism that implements binary rewriting in a transparent, efficient, and convenient way by rewriting the dynamic instruction stream rather than the static executable. Simply, we define productions (rewriting rules) that instrument program calls and returns to maintain and verify a "shadow" stack of return addresses in a protected region of memory. When invalid return addresses are detected, the application is terminated.The DISE implementation resembles previous software schemes like StackGuard and the Return Address Defender (RAD), but it can operate without source code and in dynamically-linked libraries and dynamically-generated code. It also has natural facilities for protecting the shadow stack, which provides little security if it itself is vulnerable. Finally, unlike software instrumentation, DISE checks---which are inserted by the processor at runtime---cannot be bypassed or subverted.
Routing table update epoch in packet-switching networks

A computer communication network must be capable of managing its resources efficiently using a routing procedure, flow control, and buffer management techniques. A general network simulator has been developed as a tool in evaluating the many possible combinations of such techniques. It can also be used in evaluating existing strategies in operating networks and investigating new techniques. In this paper the simulator has been used to investigate several strategies of determining an optimum routing table epoch.
Motor cortical decoding performance depends on controlled system order

Recent advances in intracortical brain-machine interfaces (BMIs) for position control have leveraged state estimators to decode intended movements from cortical activity. We revisit the underlying assumptions behind the use of Kalman filters in this context, focusing on the fact that identified cortical coding models capture closed-loop task dynamics. We show that closed-loop models can be partitioned, exposing feedback policies of the brain which are separate from interface and task dynamics. Changing task dynamics may cause the brain to change its control policy, and consequently the closed-loop dynamics. This may degrade performance of decoders upon switching from manual tasks to velocity-controlled BMImediated tasks. We provide experimental results showing that for the same manual cursor task, changing system order affects neural coding of movement. In one experimental condition force determines position directly, and in the other force determines cursor velocity. From this we draw an analogy to subjects transitioning from manual reaching tasks to velocity-controlled BMI tasks. We conclude with suggested principles for improving BMI decoder performance, including matching the controlled system order between manual and brain control, and identifying the brain's controller dynamics rather than complete closed-loop dynamics.
Thermal resistance between the electronic spin system of CuK2(SO4)2·6H2O (powder) and 4He-II from 0.7 to 1.8K to magnetic fields of 15 kG1

Abstract Two magnetothermodynamic methods are described for the measurement of thermal resistance between a paramagnetic sample and 4He-II. Measurements were made on high purity CuK2(SO4)2·6H2O [CPS] in the form of randomly oriented small crystals. The data have the temperature independence and approximate field dependence expected from a phonon bottleneck. Phys.
Are the favorable outcomes of splenectomy predictable inpatients with idiopathic thrombocytopenic purpura (ITP)

BACKGROUND Historically, splenectomy has been an accepted procedure in the management of immune thrombocytopenic purpura (ITP). However, it is also true that the response to splenectomy in patients with ITP seems to be unpredictable. Therefore, the purpose of this study was to identify clinical variables that might predict a favorable response to splenectomy in patients with ITP. METHODS Data were collected retrospectively for 40 adult patients with ITP who underwent laparoscopic (LS) and open (OS) splenectomy at Emory University Hospital between 1992 and 1999. Demographics and outcomes were recorded. Age, sex, disease duration, comorbidities (ASA > 2), previous response to steroids and/or other medications, and preoperative platelet count were analyzed by univariate (t-test, Fisher's exact test) and multivariate statistical methods. RESULTS Of the 20 patients in each group, improved platelet counts were noted in 18 patients (90%) in the LS group and 20 patients (100%) in the OS group. Follow-up (16 +/- 3 months) was obtained in 19 LS patients (95%) and 16 OS patients (80%), with 84% and 87.5% sustained response rates, respectively. After univariate analysis, two variables (age and disease duration) were found to be significantly related to the outcome of splenectomy (p <lt; 0.01). However, after multiple logistic regression analysis, only disease duration (relative risk = 1.083; CI, 1.004-1.167) was an independent prognostic factor for a sustained response to splenectomy. CONCLUSION These results suggest that the response to splenectomy (laparoscopic and open) in patients with ITP cannot be adequately predicted on the basis of presplenectomy clinical variables. However, disease duration and patient age should be taken into consideration when selecting patients for splenectomy.
Properties of a cytochrome P-450-dependent epoxidase in aldrin-resistant western corn rootworms, Diabrotica virgifera virgifera LeConte

Abstract A highly active cytochrome P -450-dependent aldrin epoxidase has been found in cell-free midgut fractions from western corn rootworms (Coleoptera: Chrysomelidae) resistant to cyclodiene insecticides. Optimal in vitro assay conditions for the epoxidase are pH 7.4, 31°C, 10 min of incubation, and a substrate concentration of 0.05 m M . The enzyme is concentrated in the microsomal fraction of midgut tissue, NADPH dependent, and susceptible to established cytochrome P -450 inhibitors such as piperonyl butoxide and 1-phenylimidazole. In rootworm adults, most enzyme activity occurs in gut tissue with much lower amounts in fat body and the remaining carcass. Whole body activity of the enzyme changes markedly throughout development, and is at least 24 times and 6 times more active in adults than in pupae and larvae, respectively. The possible roles of the epoxidase in dietary relationships and aldrin resistance of the rootworms are discussed.
Low-energy-electron escape lengths in SiO2.

The electron escape length, \ensuremath{\lambda}, for low-energy (8\char21{}70 eV) electrons traveling through ${\mathrm{SiO}}_{2}$ was measured with core-level soft-x-ray photoemission. The intensity of the ${\mathrm{Si}}^{4+}$ component of the 2p core level was compared to the bulk ${\mathrm{Si}}^{0+}$ component as a function of the electron final-state energy. Spectra were collected in the constant-final-state mode in order to prevent escape-depth changes within a given spectrum. Two oxides of different thickness were compared, and the extra attenuation resulting from the additional oxide on the thicker sample was used to measure the escape length. The curves resulting from an analysis which employs an exponential-attenuation model shows a minimum at an electron kinetic energy of \ensuremath{\sim}35 eV, which is a result of scattering from the bulk plasmon. Below 35 eV, \ensuremath{\lambda} increases and reaches a local maximum at \ensuremath{\sim}20 eV, at which point \ensuremath{\lambda} begins to decrease again. The decrease in \ensuremath{\lambda} at low electron energies arises in part from electron-phonon scattering. This is confirmed by the shape of the bulk Si 2p photoemission peak observed on the thicker oxide sample, which is distorted by the phonon-induced energy-loss processes. In addition, a more complete analysis of the scattering processes is presented in which elastic scattering is explicitly considered. With this model, it is shown that the small value of \ensuremath{\lambda} measured at low kinetic energies is also, in part, a thin-film effect.
Food deprivation reduces and leptin increases the amplitude of an active sensory and communication signal in a weakly electric fish

Energetic demands of social communication signals can constrain signal duration, repetition, and magnitude. The metabolic costs of communication signals are further magnified when they are coupled to active sensory systems that require constant signal generation. Under such circumstances, metabolic stress incurs additional risk because energy shortfalls could degrade sensory system performance as well as the social functions of the communication signal. The weakly electric fish Eigenmannia virescens generates electric organ discharges (EODs) that serve as both active sensory and communication signals. These EODs are maintained at steady frequencies of 200-600Hz throughout the lifespan, and thus represent a substantial metabolic investment. We investigated the effects of metabolic stress (food deprivation) on EOD amplitude (EODa) and EOD frequency (EODf) in E. virescens and found that only EODa decreases during food deprivation and recovers after restoration of feeding. Cortisol did not alter EODa under any conditions, and plasma cortisol levels were not changed by food deprivation. Both melanocortin hormones and social challenges caused transient EODa increases in both food-deprived and well-fed fish. Intramuscular injections of leptin increased EODa in food-deprived fish but not well-fed fish, identifying leptin as a novel regulator of EODa and suggesting that leptin mediates EODa responses to metabolic stress. The sensitivity of EODa to dietary energy availability likely arises because of the extreme energetic costs of EOD production in E. virescens and also could reflect reproductive strategies of iteroparous species that reduce social signaling and reproduction during periods of stress to later resume reproductive efforts when conditions improve.
PDE4 regulates tissue plasminogen activator expression of human brain microvascular endothelial cells.

Introduction Factors regulating brain tissue plasminogen activator (tPA) are pertinent for stroke. Recent observations have suggested a role for the phosphodiesterase-4 (PDE4) pathway in stroke pathogenesis, via an uncertain mechanism. We studied PDE4 regulation of tPA expression by human brain microvascular endothelial cells in a variety of conditions, including an in vitro model of ischemia.
IDENTIFYING THE WRITING TASKS IMPORTANT FOR ACADEMIC SUCCESS AT THE UNDERGRADUATE AND GRADUATE LEVELS

The authors conducted a large-scale survey to confirm that the writing skills being assessed in the GRE® General Test can be linked to writing tasks that were judged to be important by graduate faculty from a variety of subject areas and across a wide range of institutions at both the graduate and undergraduate levels. The results obtained in this study provide an additional source of validity evidence for using the GRE Analytical Writing Assessment when making admission decisions for graduate school and are also useful in evaluating its relevance for use as an outcomes measure for upper-division undergraduates.
Pacemaker potentials of serotonergic dorsal raphe neurons: contribution of a low-threshold Ca2+ conductance.

Neurons of the dorsal raphe nucleus exhibit intrinsic pacemaker potentials (gradual interspike depolarizing ramps) enabling them to sustain spontaneous rhythmic activity in the absence of synaptic interactions. A depolarizing prepotential (PP) has been observed in these cells, which appears to trigger the spike toward the end of the pacemaker cycle. The purposes of this study, carried out in the rat dorsal raphe nucleus brain slice preparation, were to (1) determine the ionic nature of the PP, (2) investigate its time- and voltage-dependent properties, and (3) investigate the possible modulation of the underlying conductance by the α1-agonist phenylephrine and by serotonin (5-HT), agents that modify dorsal raphe pacemaker activity. During intracellular recording under current clamp, PPs were completely and reversibly blocked by divalent cations indicating that Ca2+ carries a significant portion of the current causing the PPs. Ni2+ specifically inhibited the PP with no effect on high-threshold (−40 mV) Ca2+ spikes or the Ca2+ activated K+ conductance in these neurons. Activation threshold for the PP was found to be approximately −60 mV. Priming by hyperpolarization allowed removal of inactivation (de-inactivation) of the PP in a time- and voltage-dependent manner, with maximal PPs accompanying hyperpolarizing pulses to −90 mV and the de-inactivation beginning to occur between −65 and −75 mV. Single-electrode voltage-clamp experiments demonstrated a region of negative-slope conductance between −60 and −50 mV, which corresponds to the range of PP activation. The results of this study are consistent with a lowthreshold Ca2+ conductance underlying the PP whose role is to enable the membrane potential to rebound to action potential threshold at the end of the pacemaker cycle; neither phenylephrine nor 5-HT directly affected this inward current.
A method for evaluating shockwave propagation in snow

Abstract Shockwaves in snow are analyzed by developing and then solving a set of governing jump equations which are defined in terms of the jump in certain material parameters across the shockwave. This method represents an alternative means to studying shockwaves, since most previous solution techniques have involved direct integration of the governing differential wave equations. However, since this classical means is normally difficult, the use of jump equations represents a viable means of determining stress wave properties. The two methods are compared for propagation of plastic shockwaves in snow, and some comparison to data is made. The use of jump equations is shown to give results which are similar to those obtained with the direct method.
Comparative Activities and Toxicities IV: Dinitro- and Dichloronitro- Phenylamino Acids and Esters

N-2,4-Dinitrophenyl- and N-4,5-dichloro-2-nitrophenyl-α-amino acids and esters have been synthesized in an attempt to remove the toxic effects of the nitro and dichloronitro benzene nucleus to the host without removing antimicrobial activity. The esters were more effective than the free amino acids in reducing acute toxicity to mice. Some antibacterial and antifungal activity was retained in these derivatives, particularly the N-4,5-dichloro-2-nitrophenyl α-amino acids.
A simple hybrid BRDF model for discontinuous plant canopies

The geometric optical (GO) bidirectional reflectance model, combined with a component spectral signature submodel based on radiative transfer, can be used to estimate the bidirectional reflectance over discontinuous canopies. An analytical approximation of radiative transfer within a homogeneous medium derived from two stream method is adopted. A multiple scale-hotspot function that incorporates shadowing effects for smaller canopy objects like branches, stems and leaves was also well-modeled. Comparison of model results with field measurements (POLDER and PARABOLA) over an old black spruce forest in central Canada demonstrated that the model can predict the basic features of the BRDF, i.e. bowl shape and the hotspot. The benefits of the model presented are simplicity, improved treatment of multiple scattering and a new method of estimating the component signatures.
Optimization-based calibration of a triaxial accelerometer-magnetometer

In this paper, we used a robotic arm to calibrate a triaxial accelerometer and magnetometer. In particular, we estimated the sensitivity and bias of each of the three accelerometers and magnetometers that comprise the triaxial sensor. We also determined the angles between each pair of accelerometers and each pair of magnetometers.
Soft Error Rate Determination for Nanometer CMOS VLSI Logic

Nanometer CMOS VLSI circuits are highly sensitive to soft errors due to environmental causes such as cosmic radiation and charged particles. These phenomena, also known as single-event upset (SEU) induce current pulses at random times and random locations in a digital circuit. In this paper we model neutron-induced soft errors using two parameters, namely, frequency and intensity. Our soft error rate (SER) estimation method propagates both frequency (expressed as probability) and intensity as the width of single event transient (SET) pulses expressed as probability density functions through the circuit. With this model we are able to accurately model electrical masking factors in logic circuits. Also, the error pulse width density information at primary outputs of the logic circuit allows evaluation of SER reduction schemes such as time or space redundancy.
What Does the Patient Protection and Affordable Care Act Mean to You and Your Patients

THE PATIENT PROTECTION and Affordable Care Act (PPACA; Public Law 111-148) was passed by Congress last March and signed into law by President Obama. Since then, much of the valuable coverage that is provided or slated to begin over the next few years has been lost in a barrage of negative language. The purpose of this editorial is not to debate the Affordable Care Act, as we all have different opinions, but to provide an overview of what this legislation means to you and your patients from a health care perspective. Personally, with almost 60 million Americans uninsured, including patients whose preexisting conditions kept them from acquiring affordable coverage and others who were dropped from plans after falling ill, I was delighted that we finally made a step forward with a first attempt at meeting the health care needs of those patients. I might have been persuaded to go another direction with another solution, but I didn’t see any political opponents of the law providing any other solutions.
A flow-map method of representing cognitive structure based on respondents' narrative using science content

Increasing interest in science education research has focused on ways of representing cognitive structure in graphical and quantitative terms. A method is presented for displaying the sequential and multirelational ideation of scientific narrative elicited from respondents. The flow map provides a figural representation of the flow of information, the points in the flow where multirelational and recurrent linkages are made, and the time required to retrieve and express the information at major intervals in the sequence and in total. In keeping with constructivist models of information analysis, the elicitation of responses requires minimal intervention by the interviewer, and flow-map representation requires low inference for its construction, providing a convenient diagram of the sequential and multirelational thought patterns expressed by the respondent. The method is illustrated by analyzing interviews from students varying in academic achievement under two interview conditions that varied in emphasis on recall of multiple relationships. The illustrative data show that students of increasing academic ability produce flow maps of more complex patterns with more cross-relational linkages. These kinds of linkages, on the whole, increase with increased emphasis in the interview on recall of relationships.
Shape-based interpolation of multidimensional objects

A shape-based interpolation scheme for multidimensional images is presented. This scheme consists of first segmenting the given image data into a binary image, converting the binary image back into a gray image wherein the gray value of a point represents its shortest distance (positive value for points of the object and negative for those outside) from the cross-sectional boundary, and then interpolating the gray image. The set of all points with nonnegative values associated with them in the interpolated image constitutes the interpolated object. The method not only minimizes user involvement in interactive segmentation, but also leads to more accurate representation and depiction of dynamic as well as static objects. The general methodology and the implementation details of the method are presented and compared on a qualitative and quantitative basis to the existing methods. The generality of the proposed scheme is illustrated with a number of medical imaging examples. >
Interstitial pressure, volume, and flow during infusion into brain tissue.

A model of infusion-induced swelling in the brain is presented, in which gray and white matter are treated as poroelastic media. The distributions of interstitial pressure, flow, and volume are derived for steady-state and transient infusion protocols. A significant percentage increase in interstitial volume is predicted near the injection site, despite only a modest increase in tissue-averaged fluid content there. The model also can be used to estimate mechanical parameters of brain tissue, such as its hydraulic permeability, shear modulus, and Lame constant. A solute transport equation that incorporates tissue swelling is also presented. This work suggests that knowing the distribution of swelling induced by infusion is a prerequisite to describing interstitial transport of solutes.
Detection of Chlamydia Trachomatis in Adolescent Females Using Direct Immunofluorescence

Direct immunofluorescent slide tests for the detection of genital Chlamydia trachomatis have attracted considerable attention because of their speed and economy, but most evaluation trials have concentrated on adult, high-risk populations. Using 152 paired specimens, we compared the Syva Micro Trak direct specimen test with culture in a population of adolescent females attending a general adolescent medicine clinic. The direct slide test was 90 percent sensitive and 95 percent specific overall, with positive and negative predictive values of 74 percent and 98 percent, respectively. Prevalence by culture was 13 percent. Six of our 23 positive slide tests could not be confirmed by culture. A positive chlamydia culture was significantly associated with nonwhite race, a positive Gram's stain, and the presence of mucopurulent endocervical discharge, but not with oral contraceptive pill use, obstetrical history, Pap smear results, multiple sexual partners, coexisting vaginitis or gonorrhea, or a history of prior sexually transmitted diseases. The direct test appears to be an acceptable substitute for culture in higher prevalence adolescent settings and a useful screening adjunct in lower prevalence groups.
Triterpènes Du Latex De Bursera

Les constituants majeure du latex de quatre especes de Bursera sont l'α-amyrine et le 3α-hydroxylupene (epilupeol).
Transport of n-paraffins in zeolite T

Mass transport of n-heptane, n-nonane, and n-dodecane in zeolite T was studied using a gravimetric uptake technique. The sigmoidal shape of the uptake curves indicated the existence of a nondiffusional resistance in the transport process. To compute the transport parameters, an approach based on the temporal moments of the uptake curves was developed. A model involving an external resistance dependent on the local slope of the sorption isotherm best represented the data. No evidence of the window effect reported by Gorring was found. The measured diffusivities decrease with chain length, while the activation energies remain essentially constant. Both resistances (diffusional and nondiffusional) depend strongly on lattice loading, and their relative contributions for the transport time change as saturation is approached.
FROM STAR CHARTS TO STONEFLIES: DETECTING RELATIONSHIPS IN CONTINUOUS BIVARIATE DATA

Within many ecological systems, relationships between controlling factors and associated response variables are complex. In many cases, the response should vary little when the controlling factor exerts strong effects. Conversely, when the effect of the controlling factor is weak or absent, the response may vary greatly with effects of other factors. Correlation or regression analyses often may not be appropriate for testing these relationships, because variance of the response changes with values of the controlling factor. We suggest using a technique from the astronomy literature, a two-dimensional Kolmogorov-Smirnov (2DKS) test, to detect relationships in bivariate data with these patterns of variance. This technique successfully identified simulated bivariate data composed of paired independent values as having nonsignificant relationships and simulated bivariate data in which mean and variance of y was constrained at high levels of x as having significant relationships. Using these simulations and examples from aquatic and terrestrial systems, we demonstrate that the 2DKS is a robust test for detecting nonrandom patterns in bivariate distributions that commonly arise in many ecological systems.
Prostate cancer specific integrin αvβ3 modulates bone metastatic growth and tissue remodeling

The management of pain and morbidity due to the spreading and growth of cancer within bone remains to be a paramount problem in clinical care. Cancer cells actively transform bone, however, the molecular requirements and mechanisms of this process remain unclear. This study shows that functional modulation of the αvβ3 integrin receptor in prostate cancer cells is required for progression within bone and determines tumor-induced bone tissue transformation. Using histology and quantitative microCT analysis, we show that αvβ3 integrin is required not only for tumor growth within the bone but for tumor-induced bone gain, a response resembling bone lesions in prostate cancer patients. Expression of normal, fully functional αvβ3 enabled tumor growth in bone (incidence: 4/4), whereas αvβ3 (−), inactive or constitutively active mutants of αvβ3 did not (incidence: 0/4, 0/6 and 1/7, respectively) within a 35-day-period. This response appeared to be bone-specific in comparison to the subcutis where tumor incidence was greater than 60% for all groups. Interestingly, bone residing prostate cancer cells expressing normal or dis-regulated αvβ3 (either inactive of constitutively active), but not those lacking β3 promoted bone gain or afforded protection from bone loss in the presence or absence of histologically detectable tumor 35 days following implantation. As bone is replete with ligands for β3 integrin, we next demonstrated that αvβ3 integrin activation on tumor cells is essential for the recognition of key bone-specific matrix proteins. As a result, prostate cancer cells expressing fully functional but not dis-regulated αvβ3 integrin are able to control their own adherence and migration to bone matrix, functions that facilitate tumor growth and control bone lesion development.
FoxO transcription factors promote autophagy in cardiomyocytes.

In the heart, autophagy is required for normal cardiac function and also has been implicated in cardiovascular disease. FoxO transcription factors promote autophagy in skeletal muscle and have additional roles in regulation of cell size, proliferation, and metabolism. Here we investigate the role of FoxO transcription factors in regulating autophagy and cell size in cardiomyocytes. In cultured rat neonatal cardiomyocytes, glucose deprivation leads to decreased cell size and induction of autophagy pathway genes LC3, Gabarapl1, and Atg12. Likewise, overexpression of either FoxO1 or FoxO3 reduces cardiomyocyte cell size and induces expression of autophagy pathway genes. Moreover, inhibition of FoxO activity by dominant negative FoxO1 (Δ256) blocks cardiomyocyte cell size reduction upon starvation, suggesting the necessity of FoxO function in cardiomyocyte cell size regulation. Under starvation conditions, endogenous FoxO1 and FoxO3 are localized to the nucleus and bind to promoter sequences of Gabarapl1 and Atg12. In vivo studies show that cellular stress, such as starvation or ischemia/reperfusion in mice, results in induction of autophagy in the heart with concomitant dephosphorylation of FoxO, consistent with increased activity of nuclear FoxO transcription factors. Together these results provide evidence for an important role for FoxO1 and FoxO3 in regulating autophagy and cell size in cardiomyocytes.
Update of human and mouse forkhead box ( FOX ) gene families

The forkhead box (FOX) proteins are transcription factors that play complex and important roles in processes from development and organogenesis to regulation of metabolism and the immune system. There are 50 FOX genes in the human genome and 44 in the mouse, divided into 19 subfamilies. All human FOX genes have close mouse orthologues, with one exception: the mouse has a single Foxd4, whereas the human gene has undergone a recent duplication to a total of seven (FOXD4 and FOXD4L1 → FOXD4L6). Evolutionarily ancient family members can be found as far back as the fungi and metazoans. The DNA-binding domain, the forkhead domain, is an example of the winged-helix domain, and is very well conserved across the FOX family and across species, with a few notable exceptions in which divergence has created new functionality. Mutations in FOX genes have been implicated in at least four familial human diseases, and differential expression may play a role in a number of other pathologies -- ranging from metabolic disorders to autoimmunity. Furthermore, FOX genes are differentially expressed in a large number of cancers; their role can be either as an oncogene or tumour suppressor, depending on the family member and cell type. Although some drugs that target FOX gene expression or activity, notably proteasome inhibitors, appear to work well, much more basic research is needed to unlock the complex interplay of upstream and downstream interactions with FOX family transcription factors.