cssi/SciSciGPT-SciSciNet huggingface dataset:
Phase response properties of half-center oscillators.

We examine the phase response properties of half-center oscillators (HCOs) that are modeled by a pair of Morris-Lecar-type neurons connected by strong fast inhibitory synapses. We find that the two basic mechanisms for half-center oscillations, “release” and “escape”, give rise to strikingly different phase response curves (PRCs). Release-type HCOs are most sensitive to perturbations delivered to cells at times when they are about to transition from the active to the suppressed state, and PRCs are dominated by a large negative peak (phase delays) at corresponding phases. On the other hand, escape-type HCOs are most sensitive to perturbations delivered to cells at times when they are about to transition from the suppressed to the active state, and PRCs are dominated by a large positive peak (phase advances) at corresponding phases. By analyzing the phase space structure of Morris-Lecar-type HCO models with fast synaptic dynamics, we identify the dynamical mechanisms underlying the shapes of the PRCs. To demonstrate the significance of the different shapes of the PRCs for the release-type and escape-type HCOs, we link the shapes of the PRCs to the different frequency modulation properties of release-type and escape-type HCOs, and we show that the different shapes of the PRCs for the release-type and escape-type HCOs can lead to fundamentally different phase-locking dynamics.
The bicyclomycin sensitivities of 38 bicyclomycin-resistant mutants of transcription termination protein rho and the location of their mutations support a structural model of rho based on the F1 ATPase

Abstract A total of 38 bicyclomycin-resistant mutants of Escherichia coli transcription termination protein Rho have been isolated. The locations of their mutations identify the ATP-binding region as the functional domain inhibited by bicyclomycin. Strains containing the S266C, S266A and L208R Rho mutations are very resistant to bicyclomycin in vivo. In a similar way, the mutant Rho proteins containing these mutations are very resistant to bicyclomycin in vitro. These data suggest that Ser266 and Leu208 might make direct contact with the antibiotic. These two residues are close to each other in the tertiary structure of a model of Rho based on the alpha and beta subunits of the F1 ATPase, supporting the validity of the model. The strain containing the G337S Rho mutation also has high bicyclomycin resistance, and the proximity of L208, S266 and G337 in the quaternary structure of the Rho model has enabled a candidate bicyclomycin-binding pocket to be delineated. As a whole, the bicyclomycin sensitivities of the mutants are consistent with the locations of their respective mutations in the model of Rho based on the F1 ATPase, therefore supporting the emerging consensus model of Rho structure.
Potential theory: reformulating boundary-value problems as integral equations

We give an intuitive physical explanation showing how the Neumann and Dirichlet boundary‐value problems for Laplace's equation can be rewritten as integral equations by the use of single‐ and double‐layer boundary potentials. The ideas presented here are representative of some of the basic ideas of potential theory.
Autoregressive conditional heteroscedasticity in commodity spot prices

Muth's (1961) rational expectations model of commodity markets implies that inventory carryover creates ARCH processes in prices. The model also indicates that the expected price variance is an explanatory variable in price regressions. Hypotheses were tested on price data of twenty commodities using a variation of Engle et al. (1987) ARCH–M technique. An ARCH process was found in storable and not in non-storable commodity data, as expected. However, changes in expected price variance have no significant impact on price. Copyright © 2001 John Wiley & Sons, Ltd.
Cross-layer information sharing for wireless networks with asymmetric links

In this paper we discuss cross-layer information sharing for power- and location aware wireless networks with asymmetric links and focus on the Medium Access Control (MAC) and Network Layer protocols.
Recurrence in infinite partial words

The recurrence function R w ( n ) of an infinite word w was introduced by Morse and Hedlund in relation to symbolic dynamics. It is the size of the smallest window such that, wherever its position on w, all length n subwords of w will appear at least once inside that window. The recurrence quotient ? ( w ) of w, defined as lim sup R w ( n ) n , is useful for studying the growth rate of R w ( n ) . It is known that if w is periodic, then ? ( w ) = 1 , while if w is not, then ? ( w ) ? 3 . A long standing conjecture from Rauzy states that the latter can be improved to ? ( w ) ? 5 + 5 2 ~ 3.618 , this bound being true for each Sturmian word and being reached by the Fibonacci word. In this paper, we study in particular the spectrum of values taken by the recurrence quotients of infinite partial words, which are sequences that may have some undefined positions. In this case, we determine exactly the spectrum of values, which turns out to be 1, every real number greater than or equal to 2, and ∞. More precisely, if an infinite partial word w is "ultimately factor periodic", then ? ( w ) = 1 , while if w is not, then ? ( w ) ? 2 , and we give constructions of infinite partial words achieving each value.
SMART-games: a video game intervention for children with Autism Spectrum Disorders

In this paper, we describe the design of a preliminary prototype and pilot results of the SMART-Games suite, a video game intervention for children with Autism Spectrum Disorders (ASDs). The prototype, consisting of a stuffed animal game controller with an on-screen video game, emphasizes empathy and related social skills. The proposed design aims to accommodate users across the autism spectrum through adaptive modules focused on core deficits: sensory and motor skills, imitation and turn-taking, joint attention and theory of mind. Response from the preliminary pilot suggests that the application appeals to the target audience and further development is underway.
Augmented Exercise in the Treatment of Deconditioning From Major Burn Injury

Abstract de Lateur BJ, Magyar-Russell G, Bresnick MG, Bernier FA, Ober MS, Krabak BJ, Ware L, Hayes MP, Fauerbach JA. Augmented exercise in the treatment of deconditioning from major burn injury. Objective To investigate the efficacy of a 12-week exercise program in producing greater improvement in aerobic capacity in adult burn survivors, relative to usual care. Design Randomized, controlled, double-blinded trial. Setting Burn center. Participants A population-based sample of 35 adult patients admitted to a burn center for treatment of a serious burn injury. Intervention A 12-week, 36-session, aerobic treadmill exercise program where work to quota (WTQ) participants intensified their exercise according to preset quotas and work to tolerance (WTT) participants continued to their tolerance. Participants completed a maximal stress test at baseline and 12 weeks to measure physical fitness. Main Outcome Measure Maximal aerobic capacity. Results The WTT and the WTQ exercise groups both made significant improvements in aerobic capacity from baseline to 12 weeks ( t= −3.60, P ≤.01; t= −3.17, P ≤.01, respectively). The control group did not ( t= −1.39, P =.19). WTT and WTQ participants demonstrated significantly greater improvements in aerobic capacity in comparison to the control group members (F=4.6, P ≤.05). The WTT and WTQ groups did not differ significantly from each other with regard to their respective improvements in aerobic capacity (F=.014, P =.907). Conclusions The aerobic capacity of adult burn survivors can be improved with participation in a structured, 12-week exercise program after injury.
Cavities in dense random packings

Abstract The structure of dense random packings of hard spheres is analyzed in terms of the polyhedral cavities between spheres. Two different self-consistent schemes of polyhedron classification and identification are presented: polyhedra with all triangular faces, called deltahedra; and local arrangements allowing both triangular and four-edged faces. Two models were analyzed according to these schemes: the mechanical model of Finney Proc. R. Soc. 319A , 479 (1970), and the computer-generated model of Bennett J. appl. Phys. 43 , 2727 (1972). In addition, the number and sizes of the sites for small interstitial spheres were calculated for both models, without regard to the polyhedral classification of the cavities. The structural units described and the results may be applicable to the structure of liquid metals and metallic glasses.
Barium potassium bismuth oxide: A review

Ba1−x K x BiO3(BKBO) has aT c (onset) of 34 K. It is the highest-temperature oxide superconductor which is cubic, with a coherence length of 30–60 A. The basic properties of this compound are reviewed.
The Effect of Chain Length Compatibility on Molecular Area, Intermolecular Spacing, Dispersion Energies and Evaporation Resistance of Mixed Monolayers

Using mixed monolayers of alkyl alcohols, it was established that the unequal chain lengths cause an expansion in the area/molecule in mixed monolayers. Assuming the cross-sectional area of molecules to be circles, it was shown that a difference of two methylene groups between the two components of the mixed monolayer causes an increase in the intermolecular spacing of about 0.05 A. The small increase in intermolecular spacing strikingly decreases the resistance of mixed monolayers to evaporation of water. The surface viscosity was found to be maximum when the chain-lengths of the components were equal. The dispersion energy between alcohol molecules in the mixed monolayer was calculated using Salem's approach. It was found that a small increase in intermolecular spacing (0.05A) can decrease the dispersion energy by 6.7 kJ/mol. The magnitude of this decrease is about 1/4 of the energy of a hydrogen bond. It was further shown that the small increase in intermolecular spacing, decreases the melting point of mixed crystals by about 9°C. The chainlength compatibility of mixed surfactants also influences the bubble size, bubble stability, emulsion stability, lubrication, contact angle and wettability. In summary, using the monolayer approach, it was experimentally shown that a small change of 0.05 A in intermolecular spacing, brought about by a difference of 2 methylene groups between the two surfactant molecules, can strikingly influence the dispersion energy between the molecules. The small change in dispersion energy influences the characteristics of many engineering processes such as bubbles, foams, emulsions, lubrication and wettability.
Cardiac Resynchronization Therapy in Patients With End-Stage Inotrope-Dependent Class IV Heart Failure

Although cardiac resynchronization therapy (CRT) is beneficial in patients with drug-refractory New York Heart Association (NYHA) class III/IV heart failure (HF) and left ventricular (LV) dyssynchrony, CRT efficacy is not well established in patients with more advanced HF on inotropic support. Ten patients (age 55 ± 13 years) with inotrope-dependent class IV HF (nonischemic [n = 6] and ischemic [n = 4]) received a CRT implantable cardioverter-defibrillator device. QRS duration was 153 ± 25 ms (left branch bundle block [n = 7], intraventricular conduction delay [n = 2], and QRS
Kindergarten child care experiences and child achievement and socioemotional skills

Abstract Young children's experiences outside of both home and school are important for their development. As women have entered the labor force, child care has become an increasingly important context for child development. Child care experiences prior to school entry have been well-documented as important influences on children's academic and socioemotional development. However, less is known about the importance of non-parental, out-of-school care for young school-age children's development. Using a nationally representative sample of kindergartners (n = 16,888), this study examined the relationship between child care experiences during the kindergarten year and children's academic and socioemotional skills. Given that the amount of time available for child care is by definition related to the type of kindergarten a child attends, differences in the relationship between child care and child development were explored separately by full- and part-day kindergarten. Results showed that across both types of kindergarten, more hours of center care during the kindergarten year were associated with small improvements in math test scores for all children. Any center child care during the kindergarten year was associated with increased problem behavior and decreased prosocial skills, even after accounting for a large number of confounding factors. Differences by family income and child gender were also investigated. Implications for policy and practice are discussed.
The rise and rule of a trade-based strategy: Historical institutionalism and the international regulation of intellectual property

ABSTRACT One of the most dramatic instances of international market regulation in the twentieth century was the adoption of a multilateral, enforceable, intellectual property protection regime at the end of the Uruguay Round of trade negotiations in 1994. The Agreement on Trade-Related Aspects of Intellectual Property (TRIPS) ushered in a new era of high standards of intellectual property protection, requiring profound and costly domestic institutional changes in many, many countries. International market regulation has increasingly penetrated domestic regulatory environments in ways that have compromised domestic political bargains. Historical institutionalism can help to explain the emergence of a global regime for intellectual property protection as a product of institutional change in the US. Historical institutionalism provides a lens to examine the directly political (rather than technocratic or efficiency maximizing) processes establishing domestic and international power relations.
NUCLEAR GLORY SCATTERING.

Abstract A simple model in terms of surface waves for nuclear back-scattering analogous to the optical explanation of the meteorological glory is derived for spin-0 and spin - 1 2 particles from spin-0 targets. Numerous examples of α scattering from spinless nuclei in the energy range from 18 to 50 MeV and π+ scattering from protons in the range 2 to 8 GeV are fit successfully with the model. The model yields estimates of the radius of interaction whose values are in agreement with radii determined by other means. Other theories and models relating to backscattering are discussed and attention is called to the similarity between our model and the Regge-pole treatment of this problem by Ceuleneer, Demeur, and Reignier.
Periodane: A wealth of structural possibilities revealed by the Kick procedure

Twenty seven new isomers, considerably lower in energy than the two previously reported structures of the novel molecule periodane, LiBeBCNOF, are found theoretically using a stochastic search methodology at the B3LYP/6–31G(d) level of theory. The global minimum is predicted to lie 122 kcal/mol lower in energy than the previously claimed lowest energy structure. The importance of an automated isomer search method to help find isomers on the potential energy surface of molecules in the gas phase is emphasized. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Ordinary Passions and Philosophic Morality: On the Uniqueness of Montesquieu's Commercial Republic

Abstract Near the outset of The Spirit of Laws, Montesquieu introduces what he calls the “laws of morality,” enticingly describes these laws as philosophic and self-regarding, and then lets them go missing at length. How do we account for the early disappearance and late return of Montesquieu's moral laws? This article makes the attempt by dwelling on their connection to the human being's natural passions as the philosophe presents it. The Spirit of Laws is read as an invitation to seek a government that allows humanity's passionate nature its expression, and it is shown that, alone among the governments studied in Montesquieu's work, the commercial republic of separate powers provides the venue. When ordinary passions flourish, the “laws of morality” come into play and guide them. Here is philosophic morality as commercial morality.
A Novel Bone Morphogenetic Protein 2 Mutant Mouse, , Displays Impaired Intracellular Handling in Skeletal Muscle

We recently reported a novel form of BMP2, designated nBMP2, which is translated from an alternative downstream start codon and is localized to the nucleus rather than secreted from the cell. To examine the function of nBMP2 in the nucleus, we engineered a gene-targeted mutant mouse model () in which nBMP2 cannot be translocated to the nucleus. Immunohistochemistry demonstrated the presence of nBMP2 staining in the myonuclei of wild type but not mutant skeletal muscle. The mouse exhibits altered function of skeletal muscle as demonstrated by a significant increase in the time required for relaxation following a stimulated twitch contraction. Force frequency analysis showed elevated force production in mutant muscles compared to controls from 10 to 60&#x2009;Hz stimulation frequency, consistent with the mutant muscle&#x2019;s reduced ability to relax between rapidly stimulated contractions. Muscle relaxation after contraction is mediated by the active transport of Ca2
Direct Detection Submillimeter Spectrometer for CCAT

We present a trade study for a submillimeter direct-detection spectrometer operating at the background limit for the Cornell Caltech Atacama Telescope (CCAT). In this study we compare the classical echelle spectrometer ZEUS with the waveguide grating spectrometer Z-Spec. The science driver for this instrument is spectroscopic investigation of high redshift galaxies as their far-IR fine structure line emission is redshifted into the telluric submillimeter windows. The baseline detector consists of SQUID multiplexed TES bolometers and the ideal spectrometer to detect weak lines from distant extragalactic sources is a grating with a resolution of ~103 and a large bandwidth, covering an entire telluric submillimeter window instantaneously. Since the density of high-z sources on the sky is ~100 within a 10'×10' field of view and a redshift range of Δz~0.2 we also explore multi-object (~50 objects) capability, including articulated mirrors and flexible waveguide fibers.
A phase II trial of induction epirubicin, oxaliplatin, and fluorouracil, followed by surgery and postoperative concurrent cisplatin and fluorouracil chemoradiotherapy in patients with locoregionally advanced adenocarcinoma of the esophagus and gastroesophageal junction.

Introduction Preoperative chemoradiotherapy improves local control in patients with locoregionally advanced adenocarcinoma of the esophagus and gastroesophageal junction (GEJ). Distant failure remains common, however, suggesting potential benefit from additional chemotherapy. This phase II study investigated the addition of induction chemotherapy to surgery and adjuvant chemoradiotherapy. Methods Patients with cT3-4 or N1 or M1a (American Joint Committee on Cancer 6th edition) adenocarcinoma of the esophagus and GEJ were eligible. Induction chemotherapy, with epirubicin 50 mg/m 2 /d, oxaliplatin 130 mg/m 2 /d, and fluorouracil 200 mg/m 2 /d continuous infusion for 3 weeks, was given every 21 days for three courses, followed by surgery. Adjuvant chemoradiotherapy consisted of 50 to 55 Gy at 1.8 to 2.0 Gy/d and two courses of cisplatin (20 mg/m 2 /d) and fluorouracil (1000 mg/m 2 /d) during weeks 1 and 4 of radiotherapy. Results Between February 2008 and January 2012, 60 evaluable patients enrolled. Resection was accomplished in 54 patients (90%) and adjuvant chemoradiotherapy in 48 (80%) patients. Toxicity included unplanned hospitalization in 18% of patients during induction chemotherapy and 19% of patients during adjuvant chemoradiotherapy. There was one chemotherapy-related and two postoperative deaths. With a median follow-up of 43 months, the projected 3-year locoregional control is 88%, distant metastatic control 46%, relapse-free survival 41%, and overall survival 47%. Symptomatic response to chemotherapy and the percentage of remaining viable tumor at surgery proved the strongest predictors of survival and distant control. Conclusions Chemotherapy, surgery, and adjuvant chemoradiotherapy are feasible and produce outcomes similar to other multimodality treatment schedules in locoregionally advanced adenocarcinoma of the esophagus and GEJ. Symptomatic response and less residual tumor at surgery were associated with improved outcomes.
The action of gonadotropic hormones upon rabbit testis in vitro

1. Slices of rabbit testis have been shown to incorporate [1-14C]acetate into [14C]testosterone in vitro. This incorporation is variable but is increased by interstitial cell-stimulating hormone and follicle-stimulating hormone added in vitro or by interstitial cell-stimulating hormone and human gonadotropin administered in vivo. 2. Interstitial cell-stimulating hormone did not stimulate the conversion of [4-14C]cholesterol to [14C]testosterone by homogenate of testis but reduced TPN was shown to increase this conversion. 3. The response of slices of testis to interstitial cell-stimulating hormone in vitro was inhibited by chloramphenicol and puromycin. 4. Interstitial cell-stimulating hormone increased the incorporation of [1-14C]-valine and [1-14C]tryptophan into protein by slices of testis when the hormone was administered in vivo or added in vitro. 5. These findings suggest that interstitial cell-stimulating hormone stimulates proteins synthesis by testis and raise the possibility that this hormone may share with ACTH a mechanism of action based on increased provision of reduced TPN although it is not at present possible to conclude that both hormones produced this effect by the same means.
Eight Centuries of Sampling Inspection: The Trial of the Pyx

Abstract A sampling inspection scheme bearing striking similarities to modern procedures has been in more or less continuous operation at the Royal Mint in London for about eight centuries. The history of this scheme is reviewed, and a defect in the manner in which the critical levels were set is noted. The possibility that Master of the Mint, Isaac Newton might have grasped the nature of the defect is discussed. Finally, we review the situation at the United States Mint, where similar trials have long been held, but where steps to correct the defect were taken early in the nineteenth century.
Increase in C3 plant water-use efficiency and biomass over Glacial to present C0 2 concentrations

ATMOSPHERIC CO2 concentration was 160 to 200 μmol mol−1 during the Last Glacial Maximum (LGM; about 18,000 years ago)1, rose to about 275 (μmol mol−1 10,000 years ago2,3, and has increased to about 350 μmol mol−1 since 1800 (ref. 4). Here we present data indicating that this increase in CO2 has enhanced biospheric carbon fixation and altered species abundances by increasing the water-use efficiency of biomass production of C3 plants, the bulk of the Earth's vegetation. We grew oats (Avena sativa), wild mustard (Brassica kaber) and wheat (Triticum aes-tivum cv. Seri M82 and Yaqui 54), all C3 annuals, and selected C4 grasses along daytime gradients of Glacial to present atmospheric CO2 concentrations in a 38-m-long chamber. We calculated parameters related to leaf photosynthesis and water-use efficiency from stable carbon isotope ratios (13C/12C) of whole leaves. Leaf water-use efficiency and above-ground biomass/plant of C3 species increased linearly and nearly proportionally with increasing CO2 concentrations. Direct effects of increasing CO2 on plants must be considered when modelling the global carbon cycle and effects of climate change on vegetation.
Stopping power measurements of 20–180 keV 1H and 4He in indium phosphide using thick target backscattering

Abstract The stopping power of InP for 20–180 keV 1 H and 4 He was determined by measuring the absolute backscattering yield of thick InP targets. Several nonideal aspects of surface barrier detectors were observed which should be accounted for when making low to medium energy backscattering yield measurements. These are: non-Gaussian detector resolution, nonlinear detector energy calibration, and ion reflection in the detector Au window. The present 1 H in InP stopping cross section measurements are in good agreement with those recently obtained by Khodyrev et al. using a relative, bulk yield, single spectrum approach. The 4 He in InP stopping cross section measurements were found to be velocity proportional below 30 keV/amu. The estimated standard error of the measurements is ±7% at 20 keV and ± 4% at 180 keV.
An antioxidant function for DMSP and DMS in marine algae

The algal osmolyte dimethylsulphoniopropionate (DMSP) and its enzymatic cleavage product dimethylsulphide (DMS) contribute significantly to the global sulphur cycle, yet their physiological functions are uncertain. Here we report results that, together with those in the literature, show that DMSP and its breakdown products (DMS, acrylate, dimethylsulphoxide, and methane sulphinic acid) readily scavenge hydroxyl radicals and other reactive oxygen species, and thus may serve as an antioxidant system, regulated in part by enzymatic cleavage of DMSP. In support of this hypothesis, we found that oxidative stressors, solar ultraviolet radiation, CO(2) limitation, Fe limitation, high Cu(2+) (ref. 9) and H(2)O(2) substantially increased cellular DMSP and/or its lysis to DMS in marine algal cultures. Our results indicate direct links between such stressors and the dynamics of DMSP and DMS in marine phytoplankton, which probably influence the production of DMS and its release to the atmosphere. As oxidation of DMS to sulphuric acid in the atmosphere provides a major source of sulphate aerosols and cloud condensation nuclei, oxidative stressors--including solar radiation and Fe limitation--may be involved in complex ocean atmosphere feedback loops that influence global climate and hydrological cycles.
Ranking Doctoral Programs by Journal Contributions of Recent Graduates

The productivity of graduate agricultural economics programs in the United States is measured by the number of pages and articles that recent graduates have published in the American Journal of Agricultural Economics during the last ten years. In both rankings the University of California, Berkeley, leads, followed by the University of California, Davis, Wisconsin, Minnesota, and Michigan State or Purdue. When pages are divided by the number of graduates, the University of Chicago ranks first, followed by Massachusetts Institute of Technology, Berkeley, Davis, and Rhode Island.
Effective similarity measures for expression profiles

It is commonly accepted that genes with similar expression profiles are functionally related. However, there are many ways one can measure the similarity of expression profiles, and it is not clear a priori what is the most effective one. Moreover, so far no clear distinction has been made as for the type of the functional link between genes as suggested by microarray data. Similarly expressed genes can be part of the same complex as interacting partners; they can participate in the same pathway without interacting directly; they can perform similar functions; or they can simply have similar regulatory sequences. Here we conduct a study of the notion of functional link as implied from expression data. We analyze different similarity measures of gene expression profiles and assess their usefulness and robustness in detecting biological relationships by comparing the similarity scores with results obtained from databases of interacting proteins, promoter signals and cellular pathways, as well as through sequence comparisons. We also introduce variations on similarity measures that are based on statistical analysis and better discriminate genes which are functionally nearby and faraway. Our tools can be used to assess other similarity measures for expression profiles, and are accessible at biozon.org/tools/expression/ Contact: golan@cs.technion.ac.il Supplementary information: Supplementary data are available at Bioinformatics online.
A genetic algorithm approach to solving the anti‐covering location problem

: In this paper we address the problem of locating a maximum weighted number of facilities such that no two are within a specified distance from each other. A natural process of evolution approach, more specifically a genetic algorithm, is proposed to solve this problem. It is shown that through the use of a commercially available spreadsheet-based genetic algorithm software package, the decision-maker with a fundamental knowledge of spreadsheets can easily set up and solve this optimization problem. Also, we report on our extensive computational experience using three different data sets.
Computer analysis of cardiac radionuclide data

HE impact of computers on Nuclear Cardiology and the progress which has been made through computer applications is perhaps best illustrated by several historical observations. First, it is of note that all clinically important types of nuclear cardiologic procedures were initially performed without the aid of a computer. For example, the first gated equilibrium, blood pool ventriculograms performed by Zaret et al.‘** were accomplished by analog imaging. A physiologic trigger or gate was used to turn the gamma camera image recording system on and off to define “end systole” and “end diastole” which were the only two images obtained. The gating “window” used for end diastole was the 60-msec interval immediately prior to the Rwave. For end systole, data were recorded during the T-wave. Quantitative analysis was then accomplished manually. The analog images were projected to life size and the ventricular borders traced by hand. Ventricular volumes and ejection fractions were calculated using area length formulae adapted from contrast angiography. The data obtained in this fashion correlated well with results from contrast angiography and provided a strong motivation for further technical development. Likewise, in early applications of the first pass technique, computers were not used. Rather, data were recorded on video tape for subsequent replay and analysis.3 These analog imaging techniques were extremely time consuming, particularly for purposes of quantitative analysis, took advantage of only a small fraction of the potentially available data, and provided limited visual appreciation of cardiac dynamics. The first logical adaptation of the computer to radionuclide ventriculography was simply to acquire the gated end diastolic and end systolic frames into computer memory, instead of onto film, one frame at a time. Initially the data analysis was again performed by hand by tracing ventricular contours on the computer screen. As before, this analytic approach was quite tedious and partly for this reason very little clinical use was made of radionuclide ventriculography, initially. However, several breakthroughs in computer techniques occurred in the early 1970s which established radionuclide ventriculography as a feasible clinical procedure. First, Seeker-Walker and Parker4,’ recognized that after equilibration in the blood pool the net ventricular count rate resulting from an intravascular tracer (e.g., Tc-99m albumin or Tc-99m RBC) at any time in the cardiac cycle is proportional to ventricular blood volume. This germinal observation permits calculation of the ventricular ejection fraction and other quantitative parameters through analysis of net counts (i.e., background corrected) in the ventricles (a task for which the computer is uniquely suited) rather than by the more laborious geometric technique. The formula for the count based ejection fraction is:
Uncovering a New Guilty Pleasure: A Qualitative Study of the Emotions of Personal Web Usage at Work

This longitudinal field study uncovers the emotional meaning that defines personal Web usage (PWU) at work. To explore this emergent workplace phenomenon, the author conducted 67 semistructured int...
Structural and vibrational characterization of the organic semiconductor tetracene as a function of pressure and temperature

Abstract Neutron powder diffraction and inelastic neutron scattering measurements were performed on crystalline tetracene, a molecular semiconductor of triclinic crystal structure that adopts a herringbone layered motif, as a function of pressure up to 358 MPa. In combination with theoretical and simulated computations, these measurements permit detailed characterization of the structural and vibrational changes of tetracene as a function of pressure. Powder diffraction at 295 K reveals anisotropic modification of the crystal structure with increasing pressure. Particularly, the unit cell parameters associated with the two-dimensional herringbone layers of the solid state structure displayed continuous change at all measured pressures, whereas perpendicular to the herringbone layers the structure remains relatively unchanged. The measured compressibilities along the [1 0 0], [0 1 0], and [0 0 1] crystal axes are −3.8 × 10 −4 , −1.9 × 10 −4 , and −3.4 × 10 −4 A/MPa, respectively. Inelastic neutron scattering spectra were collected at several pressures in the 25–75 and 0–25 meV energy ranges using a filter analyzer and a Fermi chopper time-of-flight spectrometer, respectively. Assignment of the spectral peaks to specific intramolecular vibrational modes has been accomplished using ab initio density functional theory calculations and the low energy lattice phonon modes were interpreted from the results of molecular dynamics simulations at 1 atm and 358 MPa. Anisotropic behavior parallel to that observed in the structural measurements is also apparent in both the intramolecular and lattice phonon vibrational dynamics. Intramolecular vibrations having atomic displacements entirely within the plane of the molecule’s aromatic ring remain unchanged with increasing pressure while vibrations with atomic displacements perpendicular to the molecular plane shift to higher energy. The lattice phonons display a similar anisotropy with increasing pressure. Phonon modes propagated within the herringbone layer are significantly shifted to higher energy with increasing pressure relative to the modes with displacements primarily perpendicular to the layers. Overall, both the planar internal geometry and the layered arrangement of the tetracene molecules significantly influence the observed structural and vibrational behavior with increasing pressure.
Unified constant-frequency integration control of three-phase standard bridge boost rectifiers with power-factor correction

In this paper, a three-phase six-switch standard boost rectifier with unity-power-factor correction is investigated. A general equation is derived that relates the input phase voltages, output DC voltage, and duty ratios of the switches in continuous conduction mode. Based on one of the solutions and using one-cycle control, a unified constant-frequency integration controller for PFC is proposed. For the standard bridge boost rectifier, a unity power factor and low total harmonic distortion can be realized in all three phases with a simple circuit that is composed of one integrator with reset along with several flips-flops, comparators, and some logic and linear components. It does not require multipliers and three-phase voltage sensors, which are required in many other control approaches. In addition, it employs constant-switching-frequency modulation that is desirable for industrial applications. The proposed control approach is simple and reliable. All findings are supported by experiments.
Understanding mitochondrial disease and goals for its treatment.

Mitochondrial disease is a progressive, debilitating, incurable illness that results from mutation of genes that regulate mitochondrial function. The disease can manifest in utero or at birth, during childhood, or have a delayed onset in adulthood. Mitochondrial disease can be transmitted as a genetically carried mutation or develop as a spontaneous genetic mutation later in life. As a multisystem disease with a highly variable clinical presentation, mitochondrial disease can present as ‘any disease with any symptoms at any age’. Consequently, all patients with progressive, unexplained multisystem illness should be evaluated for mitochondrial disease. Treatment goals include slowing of disease progression and maximising quality of life. There is no cure for this illness. Effective interdisciplinary care includes energy management, nutritional support, physical therapy and emotional support for the patient and their family.
Flow diversion and the almighty dollar.

.S. health care is too expensive and its quality too inconsistent. Patients have greater deductibles now U than ever before. The public is learning there are no demonstrable correlations between cost of service and quality (in fact, the opposite may often be true). Although there is no debate that health care costs have skyrocketed, there is legitimate debate over the real reasons and the real solutions. One of the drivers of health care costs is technology. Our country has been remarkably prolific in the development of new diagnostic tools, imaging studies, drugs, and procedures—and remarkably undisciplined in their deployment. New diagnostic and therapeutic procedures and the more liberal application of established ones account for two thirds of the growth in health care expenditures.
Review, Revise, and Resubmit:The Effects of Self-Critique, Peer Review, and Instructor Feedback on Student Writing

These experiments examined the common practice of allowing students to revise and resubmit papers after receiving feedback. Blind graders evaluated students’ first and second drafts of an introduct...
Does brightness contrast really affect the Mueller-Lyer illusion.

Summary.-Several writers have hypothesized that the Mueller-Lyer illusion is influenced by brightness contrast between figure and background. According to them, lateral inhibition in the retina causes displacement in Mueller-Lyer figures at the intersections of lines. They argue that the strength of the displacement varies with brightness contrast between the background and the figure, and they cite research by Pollack and others for support. The experiments reported here show that the Mueller-Lyer illusion is no more affected by changes in contrast than are judgments of single straight lines. These results are not consistent with the view that lateral. inhibition in the retina has an effect on the illusion. The present paper concerns Coren and Girgus's (1978) hypothesis that lateral inhibition in the retina is one of the mechanisms in producing the Mueller-Lyer illusion. Similar, though less detailed, arguments have also been made by Pollack ( 1970), Robinson ( 1972), and Watson ( 1977). According to Coren and Girgus, displacement of contour in the direction of the observed illusion is produced by lateral inhibition at and near the intersections of the fins and the shaft of the Mueller-Lyer figure. Since lateral inhibition is a function of brightness contrast, it follows that the Mueller-Lyer illusion should be a function of brightness contrast. Coren and Girgus cite as evidence a number of studies (Ebert & Pollack, 1972a, 1972b; Pollack, 1970) which have shown that the Mueller-Lyer illusion decreases as brightness contrast decreases. Thus Coren and Girgus argue that the Mueller-Lyer illusion is produced, at least in part, by lateral inhibition. Pollack ( 1970) has argued that individuals with darker ocular fundus pigmentation experience less brightness contrast between figures and background than individuals with lighter pigmentation because less light is reflected off the back of the eyes. Several studies (Ebert & Pollack, 1972a, 1972b; Pollack, 1970; Pollack & Silvar, 1967) have supported Pollack's hypothesis by demonstrating that the judgments of the Mueller-Lyer shafts were smaller for individuals with dark pigmentation. There is some evidence for questioning Pollack's conclusions. These studies used only obtuse-aAgled figures, but Bayer and Pressey (1972), in the only study which used a measure of relative illusion, not just judgments of obtuse-angled figures, found that darkness of pigmentation was not significantly related to the illusion.
Thermooxidatively stable articulated benzobisoxazole and benzobisthiazole polymers

Articulated all-para polymers with 2,6-benzobisoxazole and 2,6-benzobisthiazole units in the backbone weree synthesized by copolycondensation in polyphosphoric acid of 4,6-diamino-1,3-benzenediol dihydrochloride and 2,5-diamino-1,4-benzenedithiol dihydrochloride, respectively, with terephthalic acid and reactive 3,3′-biphenyl or 4,4′-(2,2′-bipyridyl) monomers. Inherent viscosities of up to 13.18 dL/g (CH3SO3H, 25°C, 0.2 g/dL) were achieved. The average length of the rodlike all-para segments between the relatively flexible biphenyl or bipyridyl units was controlled by the stoichiometry of the copolycondensation reactions. Dependent upon the solids content of the polymerization mixture and the mole proportion of the flexible units in the polymer backbone, copolycondensation proceeded in the liquid-crystalline state to give polymerization mixtures which exhibited lower bulk viscosities than comparable copolycondensation reactions that remained in the isotropic state. Films which exhibited optical birefringence under crossed polars could be cast from methanesulfonic acid solutions of the polymers. Thermooxidative stability of the articulated polymers was evaluated by isothermal aging in air at 371°C. Stability for the polymers was found to decrease slightly with increased content of the flexible biphenyl structure in the polymer backbone. The biphenyl structure was found to be more thermooxidatively stable than the bipyridyl structure.
A simple, predictable method for repositioning a complete denture for soft-lining procedures.

The use of implants and bone grafting procedures require an increased reduction of the intaglio of the prosthesis.1-3 This frequently compromises occlusal stability. The variability in the viscosity of the soft liner often requires the clinician to perform the reline procedure in multiple increments until the desired position is attained. The disadvantages of incremental buildups include excessive chair time and lack of control over the vertical and horizontal relationships of the arches. This article presents a dual-stage technique for applying a soft liner to ensure that a proper horizontal and vertical relationship is established for the prosthesis during its use in the transitional phase of treatment. PROCEDURE 1. Trim the intaglio of the denture to eliminate undercuts and overextensions. Try the prosthesis in the mouth to ensure smooth, comfortable seating (Fig. 1). 2. Use green stick modeling plastic (Kerr, Romulus, Mich.) to stabilize the denture. Place 3 increments of the material in the intaglio of the denture with a tripoded distribution (Fig. 2). Repair acrylic resin may be used instead of compound to shim the prosthesis. The anterior increment engages the implant’s healing cap as a
A study of the accuracy of a commercially available volumeter

Abstract This study evaluated the accuracy of the Hand Volumeter manufactured by Volumeters Unlimited. Following the method recommended by the manufacturer, water displacement measurements were taken on 13 edematous and 16 normal hands and a rubber model. Standard deviation, 95% probability range, and coefficient of variation were established for each data set. Inter- and intrarater reliability were determined for each group. The volumeter was found to be accurate to within 1% of the total volume when successive measurements are performed by one examiner. Data were also subjected to analysis to rule out inherent test error and to establish a true representation in milliliters (ml) of an actual change in tissue volume. It was determined that measurements must differ by 10 ml in a normal hand and by 12 ml in an edematous hand when taken by a given tester. Additionally factors leading to possible inaccuracies in measuring are discussed.
Flows of Electrolytes Through Charged Hydrated Biological Tissue

In this paper, analyses of the flows of water and electrolytes through charged hydrated biologic tissues (e.g., articular cartilage) are presented. These analyses are based on the triphasic mechano-electrochemical theory developed by Lai and coworkers (1991). The problems analyzed are 1-D steady permeation flows generated by a hydraulic pressure difference and/or by an osmotic pressure difference across a finite thickness layer of the tissue. The theory allows for the complete determination of the ion concentration field, the matrix strain field as well as the ion and water velocity field inside the tissue during the steady permeation. For flows generated by a hydraulic pressure difference, the frictional drag induces a compaction of the solid matrix causing the fixed charge density (FCD) to increase and the neutral salt concentration to decrease in the downstream direction. Further, while both ions move downstream, but relative to the solvent (water), the anions (Cl− ) move with the flow while the cations (Na+ ) move against the flow. The theory also predicts a well-known experimental finding that the apparent permeability decreases nonlinearly with FCD. For flows generated by an osmotic pressure difference, first, fluid flow varies with the FCD in a nonlinear and non-monotonic manner. Second, there exists a critical FCD below which negative osmosis takes place.
Evidence of Tropical Forcing of the 6.5-Day Wave from Lightning Observations over Africa

A study employing observations and climatic reanalysis data is concerned with links between convection and the well-documented 6.5-day stratospheric global wave. Observations from a long-range lightning detection network, known as ZEUS, reveal an in-phase behavior between the maximization of daily lightning activity over Africa and the intensification of the wave. To extend the observations on a climatological basis, the authors make use of the outgoing longwave radiation (OLR) as proxy for convection and the surface level pressure (SLP) as an indicator of atmospheric column forcing. Cross-spectral analysis shows significant peaks in coherency between OLR and SLP, apparent only over equatorial Africa and South America (Amazon basin), while strong coherency in this frequency band is absent over the Maritime Continent.
Dynamic responses of PCB under product level free drop impact

The peak value of out-of-plane displacement of printed circuit board (PCB), when it is subjected to drop impact, is a major concern to electronic manufacturers as it relates to the maximum stress causing failure for the solder balls. In this work, the full-field dynamic responses of printed circuit boards (PCBs) of product level are measured and analyzed in detail with the aid of Digital Image Correlation (DIC) method. In contrast to the board level drop test, which can be more easily instrumented by following the JEDEC test standards, the product-level drop test requires great effort in controlling the impact orientation, which is critical to ensure the consistency of test results. Moreover, carefully guided free drop condition is essential in investigating the mechanical dynamic behaviors of PCBs to capture the realistic dynamic behaviors during free drop impact. Several effects of test variables, such as drop height, PCB supports, casing shape, and battery weight distribution, are carefully studied case by case. Along with the free drop impact experiments, the 3D FEA models are analyzed using ANSYS/LS-DYNA™. The simulation studies and experimental results are useful for improving the design of cellular phones with lower PCB deflection under impact shock.