cssi/SciSciGPT-SciSciNet huggingface dataset:
The Contractile and Control Sites of Natural Actomyosin

The various contractile and control sites of natural actomyosin gel were studied by comparing the kinetics of ATP hydrolysis with those of gel contraction, measured as an increase in turbidity. Contraction of actomyosin gel seems to require the cooperative reaction of ATP (with Mg) at two different sites. One of these sites catalyzes the hydrolysis of ATP and most probably contributes the driving force for contraction; the binding of ATP to the other site appears to break certain links that retard movement of the gel components. At limiting concentrations of ATP, the rate of contraction seems to depend on the rate of breaking these links as well as on the rate of ATP hydrolysis. But when both sites are saturated, the rate of contraction appears to be limited only by the rate of ATP hydrolysis. In addition to these two contractile sites, there are also two different control sites. At one, the relaxing site, the binding of ATP with Mg inhibits ATP hydrolysis and gel contraction. At the other, the binding of calcium activates contraction by overcoming the inhibitory action of Mg and ATP at the relaxing site. This control system—inhibition by substrate and disinhibition by calcium—can be selectively inactivated by heat and reactivated by dithiothreitol, a disulfide-reducing agent. These observations on the isolated contractile system are discussed in relation to the contraction and relaxation of muscle.
Massive embryonal cell carcinoma of testes.

Abstract A search of the literature failed to yield previous reports of malignant testicular tumors as large as the 2,730-Gm. embryonal cell testicular carcinoma reported here.
Production of a cell-associated and secreted plasminogen activator by cultured rat granulosa cells.

The localization and time-related production of plasminogen activator (PA) by ovarian granulosa cells was studied by measuring the plasmin-mediated lysis of the chromogenic substrate H-d-norleucyl-hexahydrotyrosyl-lysine-p-nitroanilide diacetate. Granulosa cells from diethylstilbestrol-implanted immature rats produced both a cell-associated and a secreted PA, as indicated by increased hydrolysis of the substrate by the cells or extracellular medium. The formation of cellular PA was induced by FSH and was detectable as early as 2 h during a 72-h culture, with 80% of the maximal activity present by 6 h. In contrast, negligible PA activity was detected in the extracellular medium until 6–20 h of culture, after which time the secreted PA activity continued to rise throughout the 72-h culture period. Control cells also produced both cellular and secreted PA, but in lower amounts than cells stimulated by FSH. The presence of cellular PA was further indicated by a 2-fold rise in PA activity after solubilization ...
Epsilon-N-dimethyllysine in amoeba actin.

AMOEBA actin, a protein that shares many of the chemical, physical, and ultrastructural properties of muscle actin, has recently been isolated from Acanthamoeba castellanii1,2. The final steps in the purification procedure are the sedimentation of polymerized amoeba F-actin, its depolymerization by prolonged dialysis against a solution of ATP, and separation by molecular filtration on ‘Sephadex G-200’ of a minor excluded fraction and a major included fraction (amoeba G-actin). The product is monodisperse as judged by sedimentation equilibrium centrifugation in 5 M guanidine1 and has a molecular weight of about 39,500. Polyacrylamide gel electrophoresis at pH. 9.5 in 8.5 M urea of the reduced, carboxymethylated protein shows one major band that accounts for more than 90 per cent of the stainable protein. The amino-acid composition of amoeba actin was found to be very similar to that of other act ins including approximately 1 mole of the rare amino-acid 3-methylhistidine (3-MH) per mole of protein1. In addition, an unidentified component was detected which had the same elution time as e-N-methyllysine in the chromatographic system used1 which does not separate monomethyllysine from dimethyllysine.
FATTY ACID SPECIFICITIES AND RATES OF CHOLESTEROL ESTERIFICATION IN VIVO AND IN VITRO.

Abstract The esterification of cholesterol and the formation of different fatty acid esters of cholesterol were studied after the administration of radiomevalonate or cholesterol-4-C14 to rats or Cebus monkeys. Cholesterol-4-C14 in the free form for intravenous injection was prepared by incubation of plasma at 0 ° C with radiocholesterol on Celite. After injection of mevalonate-2-C14 into rats or monkeys or cholesterol-4-C14 into rats, the specific activity of plasma cholesteryl arachidonate was higher and that of cholesteryl oleate lower than the specific activity of total plasma cholesterol esters for at least 6 hours. After the administration of cholesterol-4-C14 intravenously, the free cholesterol specific activity of liver was equal to that of plasma within 1 hour, but the ester cholesterol specific activity of plasma was three times greater than that of liver at 1 hour. The liver and plasma cholesterol ester specific activities did not become equal for nearly 12 hours. Cholesterol-4-C14 esterification by plasma in vitro resulted in a heterogeneous pattern similar to that seen in the early periods of the in vivo experiments. Esterification of radiocholesterol with different fatty acids by liver preparations in vitro was not similar to that seen in plasma. It was concluded from estimates of the rates of cholesterol esterification in plasma in vivo and in vitro that the plasma esterification activity was of considerable significance in maintenance of the level of plasma cholesterol esters. It was proposed that the early heterogeneity of labeling of different cholesterol esters in vivo resulted from the initial preponderant effect of the plasma esterification activity.
Design of vessel ligation simulator for deliberate practice.

Abstract Background Surgical residents develop technical skills at variable rates, often based on random chance of cases encountered. One such skill is tying secure knots without exerting excessive force. This study describes the design of a simulator using a force sensor to measure instantaneous forces exerted on a blood vessel analog during vessel ligation and the development of expert-derived performance goals. Materials and methods Vessel ligations were performed on Silastic tubing at an offset from a Vernier Force Sensor. Nine experts (surgical faculty and senior residents) and 10 novices (junior residents) were recruited to each perform 10 vessel ligations (two square knots each) with two-handed and one-handed techniques. Internal consistency for the series of vessel ligations was tested with Cronbach alpha. Maximum forces exerted by novices and experts were compared using Student t-test. Results Internal consistency across the 10 ligations on the simulator was excellent (Cronbach alpha = 0.91). The expert group on average exerted a significantly lower maximum force when compared with novices while performing two-handed (0.76 ± 0.39 N versus 1.12 ± 0.49 N, P Conclusions Although the expert group performed vessel ligations with significantly lower peak force than the novice group, there were novices who performed at the expert level. This is consistent with the conceptual framework of milestones and suggests that the skill of gentle knot-tying can be measured and develops at different chronologic levels of training in different individuals. This simulator can be used as part of a deliberate practice curriculum with instantaneous visual feedback.
On the thermodynamics of precipitate plate formation by shear above T0 assisted by solute adsorption effects

The concept of the T{sub o} temperature, at which the free energies of the matrix and product phases with the same composition are identical in the absence of stress, appears to have been introduced by Zener in 1946. He suggested that this is the upper temperature limit for the formation of martensite and also of bainite without a change in composition, with the M{sub s} falling at a lower, system-dependent temperature. To first-order, the solute-depleted or solute-enriched regions adjacent to intragranular dislocations or to grain boundaries should have no effect upon the driving force for nucleation once sufficient local diffusion has taken place to make the partial molar free energies of solutes in these regions equal to those in the bulk. Before such diffusion has taken place, the average T{sub o} temperature of the matrix in the immediate vicinity of solute-poor precipitate plates, e.g., ferrite/bainite plates in steel and {alpha}{sub 1} plates in Cu-Zn alloys, will be lower than that in the bulk alloy. Hence formation of such plates by shear at temperatures above the martensite range will then become even more difficult. Thus attempts which have been recently made to circumvent the T{sub o} restriction upon the temperature rangemore » of shear transformations by means of solute segregation to dislocations and to grain boundaries lead to either very little advantage (due to possible but weak second-order effects) or to further disadvantage thermodynamically for such transformations.« less
Image-guided technologies to facilitate the dissection of microsurgical autologous tissue-free flaps.

Many extirpative cancer operations can produce surgical wounds that are not amenable to simple primary closure techniques, and can result in visible body contour defects and deformities that are physically and psychologically unappealing to the patient. These factors lead many patients to desire the incorporation of reconstruction measures at the time of such operations. In this regard, the principle goals of the reconstructive plastic surgeon participating in extirpative cancer surgery have been to attempt to achieve optimal restoration of visible body-contour defects and deformities, thus making the patient whole after such operations. The reconstructive plastic surgeon generally accomplishes this by transferring autologous tissues from one part of the patient’s body to the area that is in need of reconstruction or repair. The main goals in these tissue-transfer operations are to minimize morbidity to the donor site and to transfer autologous tissues that resemble the original tissues removed during the extirpative cancer operation. Unfortunately, in many instances, attempts to minimize morbidity to the donor site can compromise the blood supply to the autologous tissue flap that is being transferred and can lead to an unfavorable outcome. Breast reconstruction after mastectomy represents one of the best examples of this delicate equilibrium and the resultant opposing nature of these goals. The transverse rectus abdominus myocutaneous (TRAM) flap has long been the workhorse for reconstruction in this particular setting since its introduction in 1982 by Hartrampf, Scheflan and Black [1]. In this operation, a composite flap of tissue, consisting of skin, fat and muscle from the lower abdomen, is transferred to the mastectomy defect. The blood supply to this tissue flap is from the superior epigastric artery, which courses through the rectus abdominus muscle and sends perforating vessels superficially into the overlying fat and skin. In this traditional pedicled TRAM procedure, the lower attachments of the rectus muscle are divided, allowing the skin. Fat and muscle of the lower abdomen to be rotated superiorly to the chest wall while maintaining blood supply from the superior epigastric vessels.
Anomalies in acoustical properties of mercury near the liquid–gas critical point

Abstract Results of measurements of sound velocity and attenuation in fluid mercury at sub- and supercritical parameters of state (at temperatures up to 2100 K and pressures up to 190 MPa) are reviewed. Discussion is concentrated on anomalies observed near the liquid–gas critical point. These are: (1) peculiarities in sound velocity and attenuation revealed in the close vicinity of the critical point, which can be attributed to an effect of fluctuation-induced forces in a prewetting film on the cell walls. (2) A maximum in sound attenuation in a region of a metal–dielectric transition, testifying for fluctuations accompanying the opening of a band gap. (3) A pressure dependence of sound velocity in superheated vapor, which changes sign near the critical temperature.
Observations of stacking-fault tetrahedra in an austenitic alloy after high-temperature neutron irradiation

Abstract In a recent experiment, a model austenitic alloy with a composition of 0·17Cr-0·167Ni-0·025Mo was irradiated to about five displacements per atom in the Oak Ridge Research Reactor at 550 and 600°C. Some of the specimens had been implanted with 10–50 at.p.p.m. helium and subjected to various post-implantation anneals prior to irradiation. At this low dose, relatively little void formation was observed in the specimens. However, a surprising observation was that a large number of stacking-fault tetrahedra were seen. These defects were observed in specimens irradiated at 550 and 600°C, with and without helium pre-injection, and with and without post-helium-implantation heat treatment. The average edge length was 15 to 20nm and the density varied between 8 × 1018 and 4 × 1020 m−3. The highest density was observed in a solution-annealed specimen irradiated at 600°C with no helium pre-injection. The results of this experiment support theoretical calculations which indicate that stacking-fault tetrahedr...
Estrategias técnicas para el tratamiento de la estenosis recurrente de la carótida tras angioplastia e implantación de un stent

A medida que aumenta el numero de procedimientos de angioplastia e implantacion de stents en la arteria carotida, los cirujanos vasculares deben prever la necesidad de un mayor numero de correcciones quirurgicas de las complicaciones de estas tecnicas y, en particular, la reestenosis en el stent. En el presente estudio se revisan las alternativas quirurgicas para estenosis recurrentes despues de una angioplastia e implantacion de stent. Se han usado cuatro tecnicas distintas: 1) arteriotomia longitudinal a traves del stent y angioplastia con parche, 2) bypass desde arteria carotida comun a carotida interna distal (ACI) con injerto de politetrafluoroetileno (PTFE), 3) bypass desde arteria subclavia a ACI distal con injerto de PTFE y 4) endarterectomia carotidea con extraccion completa del stent y angioplastia con parche. Las intervenciones se efectuaron con monitorizacion electroencefalografica continua. En dos pacientes se extrajeron los dispositivos. Los tiempos operatorios fueron de 133 ± 22 min y el seguimiento medio de 27,5 ± 29 meses. No se produjeron ictus, infartos de miocardio, muertes postoperatorias, ni lesiones de los pares craneales. Ningun paciente desarrollo hematomas postoperatorios del cuello con la necesidad de revision quirurgica. Todos los pacientes permanecieron estables en el seguimiento sin pruebas de estenosis recurrente en el eco-Doppler. Puede conseguirse la reparacion de una reestenosis de la carotida tras angioplastia e implantacion de un stent, con o sin la extraccion completa del dispositivo, aunque en ocasiones es necesario combinar varias tecnicas en funcion de la longitud y la localizacion de la lesion y de los dispositivos, la presencia de oclusion completa de la carotida comun y el grado de inflamacion circundante.
Spectral Analysis of Wave Motion in Plane Solids With Boundaries

A spectral formulation is employed whereby in-plane stress waves are synthesized from the superposition of components at discrete frequencies and wavenumbers. The summations are performed using the fast Fourier transform and the Fourier series, respectively. Because the components are discrete, the solution to problems (over the entire field) with completely arbitrary loading, both in time and space, is made tractable. Waves generated from a line load acting on an infinite and semiinfinite plane are first considered. A cascade approach is then adopted for the treatment of these waves incident on a free, fixed, and elastic boundary. At each stage, the results are compared with those obtained from the available classical solutions and/or finite element results. These studies will form the basis for the investigation of in-plane stress waves in multiply layered media.
Clinical outcomes following stent implantation in internal mammary artery grafts.

We evaluated our experience with percutaneous coronary intervention (PCI) of internal mammary artery (IMA) grafts. From the institution's database we identified 288 patients with 311 IMA lesions. Of these, 82 (26.4%) had stents placed during PCI. Angiographic success was 92%. Mortality at 1 month was 1.7%, myocardial infarction (MI) 15.7%, and target lesion revascularization (TLR) 0.4%. Cumulative 1-year event rates were mortality 6.4%, MI 20.4%, and TLR 8.0%. TLR rates were significantly higher in the stented lesions than lesions treated with angioplasty alone (19.2% vs. 4.9%; P = 0.004). The higher TLR rate in stented lesions was most apparent at the anastomotic site (25.0% vs. 4.2%; P = 0.006). Percutaneous revascularization of IMA grafts can be performed safely with high procedural success and excellent short- and long-term results. Stenting, particularly at the anastomotic site, was associated with significantly greater rates of TLR than angioplasty alone. Cathet Cardiovasc Intervent 2003;59:436–441. © 2003 Wiley-Liss, Inc.
The Bethany Traditions in the Gospel Narratives

el-'Azariyeh is probably on or near the site of the ancient New Testament village. The Arab name means "the place of Lazarus," and his traditional tomb has been located nearby since about A.D. 300, according to Gustaf Dalman.1 Through the centuries this has been traditionally regarded as the home of Lazarus and his sisters, Martha and Mary, but it is not quite so generally known as the residence of one Simon, a Pharisee and former leper, who was perhaps the husband of one of these sisters, or else the father of this well-known New Testament family. There are eleven references to Bethany in the Gospels: four in Mark, three in John, and two each in Matthew and Luke.2 In addition, there are two further incidents in Luke3 which lack definite geographic location but which from their contexts seem to refer to Bethany. All these stories appear in scattered order through the four gospels, but they are generally concentrated in the Passion Narratives. The disarranged order of the different events may have an important bearing on their meaning, both separately and collectively. The stories suggest a striking indefiniteness of locale or lack of fixity in the growing body of remembered tradition about the activities and associations of Jesus in his travels. They also indicate the probability of a second home in Bethany where Jesus maintained headquarters of a sort for his frequent visits to the Holy City.
Is three-dimensional computed tomography reconstruction justified before endovascular aortic aneurysm repair?

Objectives The endovascular management of abdominal aortic aneurysm (AAA) relies on accurate preoperative imaging for proper patient selection and operative planning. Three-dimensional (3-D) computed tomography (CT) with reformatted images perpendicular to blood flow has gained popularity as a method of AAA assessment and image-based planning before endovascular aneurysm repair (EVAR). The current study was undertaken to determine the interobserver agreement of AAA measurements obtained with axial CT and reformatted 3-D CT and to compare the consistency of the 2 methods in selecting patients for EVAR. Methods Eight observers assessed the axial CT and reformatted 3-D CT scans for 5 patients with AAAs to determine whether the patients were candidates for EVAR. 3-D CT with multiplanar reformatted images was performed by Medical Media Systems (MMS). Each observer measured the length and diameter of the proximal neck, maximal AAA, aortic bifurcation, common iliac diameter, and aortic angulation. The proximal neck and common iliac arteries were also assessed for thrombus, calcification, and tortuosity. Agreement of the measurements on axial CT scans was compared with those on MMS CT scans by calculating the κ statistic. Complete agreement was defined as κ = 1.0. The limits of agreement between observers were also calculated. Results The cumulative interobserver agreement of MMS CT scans (κ = .81) was greater than for axial CT scans (κ = .59). The κ value for each of the diameter measurements was greater with the MMS CT scans. In 79% of cases the observers' measurements were less than 2 mm from the mean with MMS CT, compared with 59% for axial CT. The κ value for deciding whether a patient was an endograft candidate on the basis of aortic neck was greater with the MMS CT (0.92 vs 0.63). The limits of agreement between observers were also better with the MMS CT. Conclusions The interobserver agreement in planning EVAR is significantly better with MMS CT compared with traditional axial CT. The routine use of MMS CT appears justified before EVAR to improve the accuracy and consistency of patient selection.
Maturational trends of EEG-sleep measures in the healthy preterm neonate.

Five physiologic groupings of 45 EEG-sleep measures were acquired from serial 24-channel EEG-sleep recordings (i.e., sleep architecture, continuity, EEG spectral, phasic, and autonomic measures), utilizing 129 studies on 56 healthy preterm infants from 28 to 43 weeks postconceptional age (PCA) who were neurodevelopmentally normal on follow-up. Regression analyses chose the least number of measures that best reflected maturation. Four of 45 variables (i.e., spectral α energy during quiet sleep, total spectral EEG energy, arousal number during active sleep, and percentage of EEG discontinuity) most significantly explained brain maturation in neonates <36 weeks PCA. Three of 45 variables (i.e., spectral θ and β energies during active sleep and spectral α energy during quiet sleep) were most representative after 36 weeks PCA. Spectral EEG energies were the strongest indicators of maturation compared with other measures, particularly in near-term neonates.
Optimal control and simulation of multidimensional crystallization processes

The optimal batch control of a multidimensional crystallization process is investigated. A high resolution algorithm is used to simulate the multidimensional crystal size distribution under the operations defined by two optimal control trajectories. It is shown that a subtle change in the optimal control objective can have a very large effect on the crystal size and shape distribution of the product crystals. The effect of spatial variation is investigated using a compartmental model. The effect of differing numbers of compartments on the size and shape distribution of the product crystals is investigated. It is shown that the crystal size distribution can be very different along the height of the crystallizer and that a solution concentration gradient exists due to imperfect mixing. The nucleation rate can be significantly larger at the bottom of the crystallizer and the growth rate can be much larger at the top. The high resolution method provides high simulation accuracy and fast speed, with the ability to solve large numbers of highly nonlinear coupled multidimensional partial differential equations over a wide range of length scales. A parallel programming implementation results in simulation times that are short enough for using the simulation program to compute optimal control trajectories.
Performance of a compact adaptive-optics system.

The design of an adaptive-optics system for correction of a beam propagating through high-speed, unpredictable optical turbulence required the use of a robust controller rather than a conventional least-squares controller. We describe the 37-channel, 50-Hz adaptive-optical system and its performance (λ/75 rms).
63Ni half-life: a new experimental determination and critical review

Abstract The 63Ni half-life has been determined to be 101.06 ± 1.97 a based on three independent measurements, conducted over the past 27 years, of the massic activity of gravimetrically-related 63Ni sources. The 63Ni assays were performed initially (in 1968) by microcalorimetry using an assumed mean β− energy per decay, and subsequently (in 1984 and 1995) by 4πβ liquid scintillation spectrometry with 3H-standard efficiency tracing. The present result is the first and only determination of the 63Ni half-life which is based on actually following the radioactive decay of 63Ni. All previously reported determinations were derived from specific activity evaluations. These earlier determinations have been scutinizingly reviewed as part of this work. Some of these previous values can be revised in lieu of more recent nuclear data and on consideration of the experimental details. Based on a critical evaluation of the extant data set, a 63Ni half-life value of T=101.1 ± 1.4 a is recommended.
TGF-beta and epithelial-to-mesenchymal transitions.

Remarkable phenotype plasticity of epithelial cells underlies morphogenesis, epithelial repair and tumor invasiveness. Detailed understanding of the contextual cues and molecular mediators that control epithelial plasticity will be required in order to develop viable therapeutic approaches targeting epithelial-to-mesenchymal transition (EMT), an advanced manifestation of epithelial plasticity. Members of the transforming growth factor (TGF-β) family of growth factors can initiate and maintain EMT in a variety of biological systems and pathophysiological context by activating major signaling pathways and transcriptional regulators integrated in extensive signaling networks. Here we will review the distinct physiological contexts of EMT and the underlying molecular signaling networks controlled by TGF-β.
Texture synthesis models and material perception in the visual periphery

The feature vocabularies used to support texture synthesis algorithms are increasingly being used to examine various aspects of human visual perception. These algorithms offer both a rich set of features that are typically sufficient to capture the appearance of complex natural inputs and a means of carrying out psychophysical experiments using synthetic textures as a proxy for the transformations ostensibly carried out by the visual system when processing natural images using summary statistics. Texture synthesis algorithms have recently been successfully applied to a wide range of visual tasks including texture perception, visual crowding, visual search, among others. Presently, we used both nonparametric and parametric texture synthesis models to investigate the nature of material perception in the visual periphery. We asked participants to classify images of four natural materials (metal, stone, water, and wood) when briefly presented in the visual periphery and compared the errors made under these viewing conditions to the errors made when judging the material category of synthetic images made from the original targets. We found that the confusions made under these two scenarios were substantially different, suggesting that these particular models do not appear to account for material perception in the periphery.
Scattering of a Rayleigh wave by an elastic three-quarter space

The steady state problem of the scattering of an incident Rayleigh wave by an elastic three-quarter space (270° wedge) is considered. The problem is reduced to the numerical solution of a pair of Fredholm integral equations of the second kind. The kernels of these equations consist of elementary functions. The reflection and transmission coefficients can be computed from two independent equations, which provides a check on both the accuracy and correctness of the results. The method used can be extended to other wedge angles.
Identification of the Putative Staphylococcal AgrB Catalytic Residues Involving the Proteolytic Cleavage of AgrD to Generate Autoinducing Peptide

The P2 operon of the staphylococcal accessory gene regulator (agr) encodes four genes (agrA, -B, -C, and -D) whose products compose a quorum sensing system: AgrA and AgrC resemble a two-component signal transduction system of which AgrC is a sensor kinase and AgrA is a response regulator; AgrD, a polypeptide that is integrated into the cytoplasmic membrane via an amphipathic α-helical motif in its N-terminal region, is the propeptide for an autoinducing peptide that is the ligand for AgrC; and AgrB is a novel membrane protein that involves in the processing of AgrD propeptide and possibly the secretion of the mature autoinducing peptide. In this study, we demonstrated that AgrB had endopeptidase activity, and identified 2 amino acid residues in AgrB (cysteine 84 and histidine 77) that might form a putative cysteine endopeptidase catalytic center in the proteolytic cleavage of AgrD at its C-terminal processing site. Computer analysis revealed that the cysteine and histidine residues were conserved among the potential AgrB homologous proteins, suggesting that the Agr quorum sensing system homologues might also exist in other Gram-positive bacteria.
Dispersion of analysts' forecasts, precision of earnings, and trading volume reaction

Abstract We examine the relation between trading volume and belief dispersion and earnings precision around earnings announcement dates. No study to date has included both information factors (i.e., belief dispersion and earnings precision) simultaneously to explain trading volume behavior. Theoretical studies such as Dontoh and Ronen (1993) and Kim and Verrechia (1991) show that trading volume depends on (a) the contemporaneous dispersion of beliefs, (b) the prior dispersion of beliefs, and (c) the precision of earnings. We model the volume response coefficient on unexpected earnings as a function of earnings precision and the volume response coefficient on contemporaneous dispersion as a function of relative change in dispersion. Contemporaneous (prior) belief dispersion is measured using the coefficient of variation of analysts' forecasts for the next fiscal year during (one month prior to) the earnings announcement month. Earnings precision is measured by (a) the inverse of the coefficient of variation of the analysts' forecast errors for five years, and (b) earnings response coefficient to abnormal earnings. We find that trading volume is (a) positively associated with earnings precision and contemporaneous dispersion of beliefs, and (b) negatively associated with the relative change in dispersion. The results are robust to changes in the measures of trading volume; i.e., similar results are obtained when trading volume levels and abnormal trading volume measures are used. The results are also robust to the number of analysts' forecasts that are available for the firms.
Surface melting in Ni55

The phenomenon of surface melting in a Ni55 cluster is predicted from results of molecular dynamics simulations.
Glucose transport in isolated mammalian pigment epithelium

Abstract The isolated retinal pigment epithelium-choroid of sheep was studied in vitro as a single membrane mounted in a Ussing chamber. The average potential of 40 tissue preparations was 6·3 mV. In all preparations the retina (apical) side was positive with respect to the choroid (basal) side. Changes in Na + , K + , or Ca 2+ concentration on the choroid side did not affect the tissue potential, whereas a ten-fold increase in K + concentration or Ca 2+ chelation by EGTA on the retina side decreased the potential. The potential was also decreased by 0·75 m m -phloridzin and 1·0 m m -dinitrophenol. Utilizing a glucose concentration gradient of 4 m m -choroid to 1 m m -retina side, the unidirectional glucose fluxes were found to be 883 nmol/cm 2 · hr choroid to retina and 222 nmol/cm 2 · hr retina to choroid. Both unidirectional fluxes were decreased by 65% Na + replacement with choline Cl. The retina to choroid flux was also decreased by 0·75 m m -phloridzin and 1·0 m m -dinitrophenol. The sodium dependence and inhibitor effects suggest that mechanisms of glucose transport other than simple diffusion are operative in sheep retinal pigment epithelium.
Classifying Maritime Vessels from Satellite Imagery with HyperNEAT

Maritime data uniquely challenges imagery analysis. Such data suffers from degradation, limited samples, and varied formats. To this end, the Hypercube-based NeuroEvolution of Augmenting Topologies (HyperNEAT) approach is investigated in addressing such challenges for classifying maritime vessels in a satellite imagery data set. The results show that HyperNEAT learns to extract features that allows better classification than those from Principal Component Analysis (PCA) and robust to differences in presentation of data. Furthermore, HyperNEAT enables a unique capability to scale trained solutions to different image resolutions.
CORRUPTION AND POLITICAL AND ECONOMIC REFORMS: A STRUCTURAL BREAKS APPROACH

In this paper we look at the impact of broad policy reforms on the levels of corruption. We use a structural break approach to identify country-specific time periods in which significant shifts in corruption levels take place. We then correlate these times of change with a set of covariates with specific focus on the impact of democratization, and trade and equity market liberalization. We find robust support for the hypothesis that episodes of reduction in corruption levels tend to be correlated with democratization and equity market liberalization.
Some properties of phototransformation of rye phytochrome in vitro.

— Much of the experimental data in the phytochrome literature has been obtained using a small-molecular-weight protein fragment. Hence, several properties of phototransformation were re-examined using large-molecular-weight rye phytochrome. The kinetics of phototransformation are first-order, both for the conversion of Pr to Pfr and for the reverse reaction. The quantum yield of phototransformation was found to be 0·28 mol Einstein-1 for the conversion of Pr to Pfr and 0·20 mol Einstein-1 for the conversion of Pfr to Pr. Intermediates in phototransformation were measured by cycling the pigment with high-intensity mixed red and far–red light. The difference spectrum of these intermediates between 367 and 575 nm was found to be similar to that previously reported for oat and pea phytochrome. Analysis of intermediate decay indicated complex kinetics and not a single first-order species. Transient absorbancy changes in the blue region of the spectrum upon actinic illumination could be attributed to differential rates of initial bleaching of the two forms of the pigment and a consequent alteration in the proportion of the two forms in the mixture until photostationary equilibrium is re-established.
Indirect Measurement of Hydrocarbon Aerosols Across the United States by Nonsulfate Hydrogen-Remaining Gravimetric Mass Correlations

In order to determine the levels of fine organic aerosols at remote sites, two methods were devised to calculate organic concentration from data collected on chemically inert teflon filters by the 34-site National Park Service (NPS) Fine Particle Network from 1982 to 1986. The remaining mass method is based on the difference between the measured gravimetric mass and the sum of the ammonium sulfate, soil, and soot carbon components, derived from measured parameters. This remaining mass is between 53% and 67% organic matter, based on two studies measuring organic carbon directly in the arid west. The nonsulfate hydrogen method is based on the concentration of particulate hydrogen, which has been measured on NPS samples since 1984, using techniques developed at Davis, CA. After removing the contribution associated with ammonium sulfate, the remaining nonsulfate hydrogen is predominantly due to organic matter. The two methods are in good agreement, with a sample to sample correlation of 0.76. For each western...
An algorithm for the dependence of sea surface radar cross section and modulation transfer function on winds, atmospheric stability and sea state

An extensive set of X-band microwave backscatter measurements has been analyzed to determine its dependence on winds near the surface, atmospheric stability, and long-wave slopes. Model functions for the radar cross section and the MTF are developed that depend on the geophysical variables. Statistical analysis shows that these models functions yield a significantly smaller error when fit to the RCS data than a simple wind speed function displays. A Taylor series expansion of the returned power from a small area provides a unified function that demonstates the complementary roles of wave slope and atmospheric fluctuations on both the RCS, the MTF and the coherence. These results have direct application to the remote sensing of the mean and fluctating winds, and the wave spectrum with coherent and incoherent active radars.
Toluene Formation from Coadsorbed Methanethiol and Benzenethiol on the Ni(111) Surface

We report our observation of interspecies carbon-carbon bond formation during the reaction of coadsorbed methanethiol and benzenethiol on the Ni(III) surface. Toluene formation has been detected between 250 and 320 K in addition to methane and benzene, the hydrogenolysis products. Increased concentrations of benzenethiolate and methanethiolate, the surface intermediates, increase the amount of toluene formed. Water formation below the toluene formation temperature decreases surface hydrogen, causing toluene yield to increase substantially compared to methane and benzene yield. Toluene increases up to a factor of 20 were observed for high coadsorbed coverages. Together, these results clearly indicate that competition between hydrogen addition and alkylation controls toluene formation. 28 refs., 3 figs.
Stage of physical activity and approach-avoidance achievement goals in university students

Abstract Objectives The main purpose of the present investigation was to examine approach-avoidance achievement goal patterns across stages of physical activity participation. In addition, sex differences in the approach and avoidance goals were examined as well as goal contrast scores (i.e., approach minus avoidance) as secondary purposes. Design The research was cross-sectional in design. Method Participants were 804 university students who completed a questionnaire assessing their stage of physical activity, 2 × 2 achievement goals, and demographics. Results MANOVA results revealed hypothesized and significant (p Conclusions Findings suggested that interventions targeting physical activity in university students should emphasize approach goals relative to the avoidance goals. Particular attention should be paid to the performance goals in the maintenance and long-term maintenance stages as they appeared theoretically inconsistent for the female participants. Last, the split in the preparation stage (active, non-active) should be incorporated into future stage based investigations as the split demonstrated two meaningfully different subgroups.
The Selective Aryl Hydrocarbon Receptor Modulator 6-Methyl-1,3,8-Trichlorodibenzofuran Inhibits Prostate Tumor Metastasis in TRAMP Mice

The aryl hydrocarbon receptor (AhR) is a basic-helix-loop-helix transcription factor that binds halogenated aromatic hydrocarbons, polycyclic aromatic hydrocarbons, and endogenous compounds. We previously reported that AhR null (Ahr(-/-)) transgenic adenocarcinoma of the mouse prostate (TRAMP) mice on a C57BL/6J background develop prostate tumors with much greater frequency than AhR wild-type (Ahr(+/+)) TRAMP mice, suggesting that the AhR has tumor suppressor properties. Because AhR signaling pathway inactivation increased susceptibility to prostate tumorigenesis, we tested the hypothesis that a selective AhR modulator (SAhRM), 6-methyl-1,3,8-trichlorodibenzofuran (6-MCDF), can protect against prostate tumorigenesis. TRAMP mice on the standard C57BL/6JxFVB genetic background were fed 0, 10, or 40mg 6-MCDF/kg diet beginning at 8 weeks of age. Tumor incidence, pelvic lymph node metastasis, and serum vascular endothelial growth factor (VEGF) concentrations were determined at 140 days of age. Prostate tumor incidence and size were not significantly reduced in mice fed 6-MCDF. However, the frequency of pelvic lymph node metastasis was reduced fivefold in mice fed the 40mg 6-MCDF/kg diet. Serum VEGF concentrations were also reduced by 6-MCDF treatment, particularly in mice without prostate tumors, and 6-MCDF was shown to act directly on cultured prostates to inhibit VEGF secretion. Together, these results suggest that 6-MCDF inhibits metastasis, in part, by inhibiting prostatic VEGF production prior to tumor formation. This is the first report that 6-MCDF can confer protection against prostate cancer in vivo.
Modal and characteristics-based approaches for modeling elastic waves induced by time-dependent boundary conditions

In this paper, we present a characteristics-based approach for solving elastic wave problems with time-dependent traction boundary conditions. A generalized mathematical model for this important class of problems is expressed as a set of first-order, linear, hyperbolic partial differential equations. We analyze the mathematical structure of this first-order linear system, verify its hyperbolicity, derive its characteristic form, and deduce its eigenvalues, eigenvectors, and Riemann invariants. The eigenvalues correspond to the wave speeds, while the Riemann invariants are used to construct a solution by the method of characteristics. We benchmark the method of characteristics against several popular modal approaches. Two of these, which we refer to as the concentrated body force method (CBFM) and the homogeneous eigenfunction expansion method (HEEM), were developed to simplify the well-established but tedious Mindlin–Goodman method. To homogenize the boundary conditions and enable modal analysis, the CBFM and HEEM forgo the usual formalism of linear transformations (a la Mindlin–Goodman) in favor of intuitive modeling assumptions and postulated solution structures. We find, however, that these approaches introduce an artificial stress discontinuity at the forced boundary in their reformulated problems. When these reformulated problems are solved by modal analysis, spurious oscillations and significant overshoot, similar to the Gibbs phenomenon, emerge in the stress profile at the artificial discontinuity. We demonstrate that these oscillations and overshoot are physical manifestations of a series solution for stress, obtained from term-by-term differentiation, that is not uniformly convergent, as required by the formalism of mathematical analysis. The method of characteristics solution, on the other hand, is exact to within machine precision, yielding no artificial discontinuities, spurious oscillations, or unphysical overshoot. Unlike the modal approaches, the method of characteristics solves the first-order problem with time-dependent boundary conditions ‘as is’ without any reformulation, restructuring, or postulated solution structures. Further, its solutions require no post-processing: no a posteriori solution treatment like l'Hopital's rule to accommodate resonance (resonant behavior is inherently captured without the emergence of singularities), no term-by-term differentiation to deduce stress (stress is primitive in a first-order velocity–stress formulation of elastodynamics), and no convergence tests.
The Effect of the Fat Solvent upon the Assay of Vitamin D for Poultry

Abstract THE method for the assay of vitamin D for poultry as it is described by the Association of Official Agricultural Chemists (1945) leaves the choice of fat solvent for the extraction of the bones to the assayer. The suggested method advocates 20 hours of extraction with hot alcohol followed by 20 hours with ether. Because of the fire hazard when ether is used, the laboratory at the Connecticut Agricultural Experiment Station has preferred to use carbon tetrachloride. From time to time the question has been raised as to whether the two methods of extraction yield the same results. To test this point, the bones and toes from six assays were used. The thoroughly dried left tibiae and toes were extracted with carbon tetrachloride as in the past; the right tibiae and toes with alcohol and ether. The fat extracted dried bones were ashed in the usual way and the group . . .
Micro- and macrodevelopmental changes in language acquisition and other representational systems

In this paper, it will be argued that each time a procedure in a representational system is functioning adequately and automatically, the child steps up to a metaprocedural level and considers the procedure as a unit in its own right. Data will be drawn from microdevelopment in children's creation of external memory devices (i.e., changes in representation of a spatial task during a one hour's session) as well as from macrodevelopment in language acquisition (i.e., changes occurring over age in a study of nominal determiners, pronouns and gender markers). These two aspects of development of representational systems are examined with respect to the spontaneous passage from concrete reference to abstract systems, from idiosyncratic to conventional notations, from redundant to economic marking, from unifunctional to plurifunctional meaningful units. These micro- and macrodevelopmental changes take place in a spontaneous fashion despite the fact that the child's earlier system is adequate for successfully conveying the information required. A discussion will be made of the way in which children tend to indicate externally, by unifunctional markers, information which was implicit in their earlier use of an adult-like system. They appear to be striving for the delicate balance between encoding and decoding efforts, ultimately leading to a felicitous representational system. Metaprocedural behavior is hypothesized to act as a control mechanism in the striving for this delicate balance of information content and information processing effort. It also appears to act as a control mechanism for the interprocedural organization of what was previously a plethora of juxtaposed, unconnected procedures yielding superficially analogous behavior. The stepping-up to a metaprocedural level seems to occur each time the child has a handle on his currently functioning, goal-oriented system. This enables the child to treat the system, or procedures which are part thereof, as units functioning in their own right. Thus there appears to be a deep-rooted psychological tendency for a representational tool which functions well procedurally to become subsequently a problem-space per se.
Delayed treatment of basilar thrombosis in a patient with a basilar aneurysm: a case report

Acute occlusion of the basilar artery is a neurological emergency that has a high risk of severe disability and mortality. Delayed thrombolysis or endovascular therapy has been performed with some success in patients who present after 3 hours of symptom onset. Here we present the first case of delayed intra-arterial thrombolysis of a basilar artery thrombosis associated with a large saccular aneurysm. A 73-year-old Caucasian man with a history of smoking and alcohol abuse presented to the Emergency Department complaining of diplopia and mild slurred speech and who progressed over 12 hours to coma and quadriparesis. He was found to have a large basilar tip aneurysm putting him at high risk for hemorrhage with lytic treatment. The treatment options for basilar thrombosis are discussed. Aggressive treatment options should be considered despite long durations of clinical symptoms in basilar thrombosis, even in extremely high risk patients.