cssi/SciSciGPT-SciSciNet huggingface dataset:
Pattern and stability in predator-prey communities: How diffusion in spatially variable environments affects the Lotka-Volterra model

Abstract Introducing a spatially heterogeneous environment to the Lotka-Volterra predator-prey diffusion model reveals that spatial pattern is amplified and the dynamics are stabilized by nonlinear environmental heterogeneity and differential species mobility. When predators diffuse and prey are sedentary, heterogeneity in the prey growth rate is amplified in the prey equilibrium distribution. When both species diffuse rapidly, patterns in their distributions are homogenized, but their total abundances are maximized. In contrast to the nonspatial constant Lotka-Volterra model, which features sustained oscillations, perturbations to the heterogeneous environment model decay to equilibrium exponentially fast. When prey are stationary, the rate of decay is proportional to the predator diffusion coefficient. The rate of approach to equilibrium slows as prey mobility increases. These results are interpreted as the creation of a prey refuge by density dependence implicit in the motion of nonuniformly distributed diffusing populations.
Two-phase pressure drop, boiling heat transfer, and critical heat flux to water in a small-diameter horizontal tube

Abstract Two-phase pressure drop, boiling heat transfer, and critical heat flux to water were studied in a small horizontal tube of 2.98-mm inside diameter and 0.91-m heated length. Experiments were performed at a system pressure of 200 kPa, mass fluxes of 50–200 kg/m2s, and inlet temperatures from ambient to 80 °C. Experimental results and comparisons with state-of-the-art predictive correlations are presented. Modifications were made to the Chisholm two-phase multiplier correlation and to the Argonne National Laboratory small-channel boiling heat transfer correlation to better predict the experimental data of the present study.
Tests of hypotheses in discrete models based on the penalized Hellinger distance

Abstract Analogues of the likelihood ratio, Rao, and Wald tests are introduced in discrete parametric models based on the family of penalized Hellinger distances. It is shown that the tests based on a particular member of this family provide attractive alternatives to the tests based on the ordinary Hellinger distance. These tests share the robustness of the Hellinger distance test, but are often closer to the likelihood-based tests at the model, especially in small samples. The convergence of ordinary Hellinger distance tests to limiting χ 2 distributions are quite slow. The proposed tests are improvements in this respect.
THREE SIBLING SPECIES OF ALECTORIS PARTRIDGE

SUMMARY In southeast Europe, two populations of Alectoris partridge meet. These differ sharply in several minor qualitative characters with no evidence of introgression. Morphological, ecological, and behavioural differences suggest that these are separate species, A. graeca and A. chukar. Clinal geographic variation of colour in the eastern Mediterranean within these two species appears to be correlated with climatic factors. The tendencies toward longer bills in southern mainland and island populations may constitute adaptations to drier and insular environments. Habitat preferences, diet, reproduction, and altitudinal distribution of these two forms are discussed and, where possible, contrasted. An additional, but less well documented example of sympatric Alectoris species is found in western China. Display in Alectoris partridge tends to emphasize the morphological patterns which are useful in taxonomy. Species characters may likewise function as warning stimuli and therefore tend to prevent mixed flocks. It is concluded that at least one of the two Balkan species has recently reached Thrace, and that at present altitudinal and possibly slight morphological and behavioural differences act as sufficient isolating mechanisms to prevent hybridization.
Numerosity and number signs in deaf Nicaraguan adults

What abilities are entailed in being numerate? Certainly, one is the ability to hold the exact quantity of a set in mind, even as it changes, and even after its members can no longer be perceived. Is counting language necessary to track and reproduce exact quantities? Previous work with speakers of languages that lack number words involved participants only from non-numerate cultures. Deaf Nicaraguan adults all live in a richly numerate culture, but vary in counting ability, allowing us to experimentally differentiate the contribution of these two factors. Thirty deaf and 10 hearing participants performed 11 one-to-one matching and counting tasks. Results suggest that immersion in a numerate culture is not enough to make one fully numerate. A memorized sequence of number symbols is required, though even an unconventional, iconic system is sufficient. Additionally, we find that within a numerate culture, the ability to track precise quantities can be acquired in adulthood.
Gyrator‐based biquad filters and negative impedance converters for microwaves

We develop and evaluate a new family of active-RC, gyrator-based, voltage-mode, biquadratic filters capable of realizing all standard second-degree filtering functions at microwave frequencies. Each biquad employs two negative second-generation current conveyors (CCII−s) or, equivalently, two infinite-conductance transistors, and we obtain excellent simulated results by implementing each of these perfect elements as a cascaded pair of MMIC GaAs FETs. The transistors in the simulation are modeled using tabulated S parameters of MB3000 (Phillips) devices. In addition, we catalog all known ideal, two-transistor negative impedance converter (NIC) topologies and we show that some are intrinsically better than others with respect to their performance when the active elements are implemented using MMIC GaAs FET CCII−s. © 1998 John Wiley & Sons, Inc. Int J RF and Microwave CAE 8: 86–101, 1998.
Déficit en el reconocimiento de emociones faciales en la esquizofrenia: Implicancias clínicas y neuropsicológicas

Las personas enfermas de esquizofrenia presentan un deficit para identificar las expresiones faciales. Esta alteracion podria estar relacionada con variables clinicas y neuropsicologicas y a su vez influir en el desempeno psicosocial de los pacientes. Objetivos: 1) Comparar el rendimiento de un grupo de personas enfermas de esquizofrenia y un grupo control en una prueba de reconocimiento de emociones faciales; 2) Investigar la relacion entre la capacidad de reconocer las emociones faciales, y variables clinicas y neuropsicologicas. Sujetos y Metodos: Se atendio a 42 personas enfermas de esquizofrenia (28 hombres, edad promedio 35 anos) y 33 controles (19 hombres, edad promedio 37 anos). Los sujetos fueron comparados usando el Test de reconocimiento de emociones de Baron-Cohen, exhibiendo tanto la cara completa como secciones de ojos y boca. Todos los pacientes completan la escala SASS de ajuste social y son evaluados con una bateria neuropsicologica (Test de Inteligencia de WESCHLER, Test de Colores y Palabras de STROOP, Serie de Digitos y Letras, California Verbal Learning Test, Test de Toulouse, COWAT) y la escala PANSS. Resultados: Los pacientes muestran, de manera estadisticamente significativa, un menor numero de aciertos, en todas las categorias evaluadas. En el grupo de pacientes estudiados no se encuentran asociaciones entre el numero de aciertos y los sintomas positivos y negativos, como tampoco con los puntajes de la escala SASS. En cuanto a las funciones cognitivas, se aprecian asociaciones estadisticas con CI, atencion y resistencia a la interferencia, pero no con memoria de trabajo, fluencia ni aprendizaje verbal
A new approach for rock mass cavability modeling

Abstract The proposed approach to study rock mass cavability consists of an attentive caving analysis incorporating main geotechnical parameters that rule this phenomenon. The modeling was elaborated in three main stages. First, numerous simulations, conducted in plasticity with the finite element method, allowed to establish a cavability relation between initial stresses, excavation dimensions and rock mechanical strength. The second step takes over if the rock material is strong enough to avoid caving, and the analysis is pursued taking into account the natural joints as a complementary parameter. The rock joints are analysed in terms of density and block volumes to check if the rock mass is fractured enough or if the block volume distribution allow possible cavability. If rock strength as well as joint density and block volume distribution do not allow to conclude rock cavability, the third stage is required and the motion of the blocks is studied. A model based on the distinct element method, enabled to simulate the caving process and to outline the conditions required for cavability with regard to the excavation's shape and dimensions as well as the orientations and the mechanical characteristics of the joints.
Stability of a Cucumber Mosaic Virus Satellite RNA Sequence Integrated into Tobacco Nuclear DNA Using Agrobacterium tumefaciens

A monomeric cDNA copy of cucumber mosaic virus (CMV) satellite RNA which is non-necrogenic to tomato was introduced into nuclear DNA of tobacco plants with the aid of the binary vector system of Agrobacterium tumefaciens. In order to check the stability of the introduced genes, kanamycin resistance and expression of biologically active satellite RNA upon infection with CMV were assayed up to the fifth generation of the homozygous progeny obtained from a primary transformant. The inserted cDNA in the progeny of the fifth generation was sequenced after cloning of the sequence amplified with the polymerase chain reaction. Neither loss nor mutations of the inserted genes were detected.
Numerical Simulations of an Active-Stressing Technique for Delaying Fracture During Cutting of Alumina

During a variety of high-speed cutting operations that can include both laser and traditional saw methods, full workpiece support is not always practical or even possible. As a result, costly premature fractures and associated damage such as chips, burrs, and cracks (ranging from the micro- all the way to the macroscale) can result. In most instances, the resulting stresses are primarily mechanical in nature and arise from the bending and/or twisting moments from the still attached scrap. Under these conditions, mixed-mode fracture is all but inevitable since the supporting section is continuously diminishing as the cut progresses. Given the predominantly mechanical, and therefore predictable, nature of the resulting stresses, it is conceivable that intentionally induced, compressive stresses due to an off-focus laser might be used to control (or at least, delay) such fractures. In this paper, the possibility of using a tailored laser-heating scenario ahead of a progressing cut to "actively" induce compressive thermal stresses to control fracture of a cantilevered plate was numerically investigated. A simulation of this active-stressing approach was achieved by using a customized finite-element formulation that was previously employed to model dual-beam laser machining. However, in this instance probabilistic fracture mechanics was used to quantify the influence of the induced compressive stresses on the time and nature of the fracture. The effect of important parameters such as CO 2 beam diameter, incident power density, positioning of the laser with respect to cut, as well as timing were then studied with respect to the goal of reducing and/or delaying the likelihood of fracture.
A Phosphatidylcholine Phospholipase C Inhibitor, D609, Blocks Interleukin-3 (IL-3)-Inducedbcl-2Expression But Notc-mycExpression in Human IL-3-Dependent Cells

Activation of the interleukin-3 (IL-3) receptor is required for the induction of cell proliferation and suppression of apoptosis in primitive hematopoietic progenitor cells. A rapid activation of tyrosine kinases and a phosphatidylcholine-specific phospholipase C has been observed in these cells in response to IL-3. The signal transduction cascades regulating cell proliferation and the suppression of apoptosis are poorly understood. Using human IL-3-dependent TF-1 cells, we have found that the tyrosine kinase inhibitor genistein blocks both the IL-3 suppression of apoptosis and the expression of the cell survival genebcl-2.In addition, we have found that D609, a specific inhibitor of phosphatidylcholine-specific phospholipase C, also inhibits IL-3-induced expression of thebcl-2gene without affecting IL-3-induced tyrosine phosphorylation. D609 also drove these cells into apoptosis even in the presence of IL-3. Significantly, genistein inhibited the IL-3 induction of bothbcl-2andc-mycgene. The latter gene is related to the induction of cell proliferation. D609, however, blocked the induction only of the cell survival genebcl-2.Thus, phosphatidylcholine hydrolysis appears linked to the induction of genes related to cell survival. These data fit with the hypothesis that there is a bifurcation in the signaling pathways downstream of IL-3 receptor-induced tyrosine phosphorylation.
“Let Me Tell You a Story”: Teacher Lore and Pre-Service Teachers

Abstract Pre-service teachers on the verge of beginning their careers in the classroom find themselves looking for new and challenging ways of looking at the task set squarely before them; namely, they benefit from a new perspective on the familiar topics of teaching and learning. Using teacher lore in a methods course offers students a number of benefits that might not be addressed through other, more traditional avenues of study. Teacher narratives both provoke and challenge the habitual perceptions that pre-service teachers tend to have just as they enter the classroom. Teacher stories help students to see explicitly the connection between what they believe about good pedagogy and what they have experienced as students in the years leading up to the start of their teaching careers. Teacher lore also increases the chances for empathetic teaching, as well as reflective practice. And finally, using teacher lore affords students the chance to see the richness and complexity of teaching and holds forth the ...
Patatin-Related Phospholipase pPLAIIIβ-Induced Changes in Lipid Metabolism Alter Cellulose Content and Cell Elongation in Arabidopsis

The release of fatty acids from membrane lipids has been implicated in various plant processes, and the patatin-related phospholipases (pPLAs) constitute a major enzyme family that catalyzes fatty acid release. The Arabidopsis thaliana pPLA family has 10 members that are classified into three groups. Group 3 pPLAIII has four members but lacks the canonical lipase/esterase consensus catalytic sequences, and their enzymatic activity and cellular functions have not been delineated. Here, we show that pPLAIIIβ hydrolyzes phospholipids and galactolipids and additionally has acyl-CoA thioesterase activity. Alterations of pPLAIIIβ result in changes in lipid levels and composition. pPLAIIIβ-KO plants have longer leaves, petioles, hypocotyls, primary roots, and root hairs than wild-type plants, whereas pPLAIIIβ-OE plants exhibit the opposite phenotype. In addition, pPLAIIIβ-OE plants have significantly lower cellulose content and mechanical strength than wild-type plants. Root growth of pPLAIIIβ-KO plants is less sensitive to treatment with free fatty acids, the enzymatic products of pPLAIIIβ, than wild-type plants; root growth of pPLAIIIβ-OE plants is more sensitive. These data suggest that alteration of pPLAIIIβ expression and the resulting lipid changes alter cellulose content and cell elongation in Arabidopsis.
Intergenerational equity: The capital-environment trade-off☆

Abstract This paper examines the trade-off between capital accumulation and environmental quality that determines an intergenerationally equitable program according to the Rawls maximin criterion. This trade-off is explored by an analysis of regular maximin programs in the framework developed by Brock. This results in a constant utility path supported by competitive prices with government imposed effluent charges and environmental rentals. Sufficient conditions for a regular maximin path to satisfy a Hartwick rule in deciding on the combination of capital and environmental quality left to future generations are given.
A tandem selected ion flow tube—triple quadrupole instrument

Abstract The design, operation and calibration of a selected ion flow tube (SIFT)—triple quadrupole instrument are described. A detailed examination of the gas-phase reaction between ClCH+2 and CH3Cl has been carried out in order to demonstrate some of the unique experimental capabilities of the new instrument. The primary reactions at room temperature and 0.6 Torr total pressure are thermoneutral Cl-isotope exchange and termolecular association to yield [ClCH2ClCH3]+, with apparent bimolecular rate coefficients of 6.6 x 10−11 and 4.1 x 10−11 cm3 s−1, respectively. Double-labelling experiments with ClCD+2 as the reactant ion identify hydride transfer as the mechanism for the observed Cl-isotope exchange. Collision-induced dissociation (CID) of the addition product yields ClCH+2 with a threshold energy of 31.1 ± 3.0 kcal mol−1. The relative yields of the35ClCH+2 and37ClCH2+ product ions produced by CID of the mass-selected (35Cl,37Cl) isotopomeric adduct have been measured as a function of the CH3Cl concentration in the flow reactor. Analysis of these data with a simple kinetic model indicates that approximately one third of the adduct-forming collisions are accompanied by Cl-exchange via hydride transfer within the collision complex. When the [ClCH2ClCH3]+ ions are formed in the flow tube by a “switching” reaction between ClCH+2(SCO) and CH3Cl, Cl-exchange does not occur, as shown by the complete retention of the original Cl-isotope in the ClCH+2 fragment ion produced by CID.
Ion trajectories in an electrostatic ion guide for external ion source fourier transform ion cyclotron resonance mass spectrometry.

An electrostatic ion guide (EIG) that consists of concentric cylinder and central wire electrodes can transport ions efficiently from an external ion source to an ion cyclotron resonance (ICR) ion trap for mass analysis, with several advantages over current injection methods. Because the electrostatic force of the EIG captures ions in a stable orbit about the wire electrode, ions with initially divergent trajectories may be redirected toward the ICR ion trap for improved ion transmission efficiency. SIMION trajectory calculations (ion kinetic energy, 1–200 eV; elevation angle, 0.30 °; azimuthal angle, 0.360°) predict that ions of m/z 1000 may be transmitted through a strong (0.01 → 3.0-T) magnetic field gradient. Judicious choice of ion source position and EIG potential minimizes the spread in ion axial kinetic energy at the ICR ion trap. Advantages of the EIG include large acceptance angle, even for ions that have large initial kinetic energy and large radial displacement with respect to the central z-axis, low ion extraction voltage (5–20 V), and efficient trapping because ions need not be accelerated to high velocity to pass through the magnetic field gradient.
Predation by Herring Gulls (Larus argentatus Coues) on two rocky intertidal crab species [Carcinus maenas (L.) & Cancer irroratus Say]

Abstract The vulnerability of crabs to predation by Herring Gulls (Larus argentatus Coues) was investigated in mid-intertidal pools. Three tethering experiments tested 1. (1) the importance of spatial refuges (algal and crevice) for the prey population of Carcinus maenas (L.) 2. (2) if Carcinus maenas and Cancer irroratus Say have different mortality rates because Carcinus maenas has a more cryptic carapace on mussel substratum. Carcinus maenas in algal refuges had significantly higher survival than crabs in the exposed treatment. This effect was apparent only in crevices of ≥ 6 cm, where survival was 90%. Comparing the two crab species, mortality of Cancer irroratus was consistently high (≥ 83%) regardless of pool assignment; Carcinus maenas mortality was pool-specific. It ranged from 16 to 50% in the pool with mussel bed, but reached 83% in a pool predominated by coralline algae substratum. This suggests that 1. (1) Cancer irroratus is less cryptic in mid-intertidal habitats where dark backgrounds such as mussel substratum can predominate 2. (2) spatial refuges in the mid-intertidal will buffer the effects of predation, especially for the cryptically colored Carcinus maenas (refuge effectiveness with Cancer irroratus was not tested). We suggest that predation by Herring Gulls (Larus argentatus Coues) in the mid-zone may cause Cancer irroratus to seek refuge in low intertidal pools and sublittoral areas where urchin barrens (lighter substratum) are more common, but inability to withstand high temperatures prevents Cancer irroratus from inhabiting high-intertidal pools.
The effect of small additions of Copper on the aging kinetics of the intermetallic layer and intermetallic particles of eutectic tin-silver solder joints

The effects of small additions of copper to the aging kinetics of eutectic tin-silver solder joints were studied. Aging of joints made with tin-silver solder containing 0.5% and 0.7% copper was carried out at various temperatures ranging to 180°C, at various times ranging to 4000 h. The small differences in the compositions of the two types of solder alloys studied did not produce any significant differences in the aging kinetics of the intermetallic layer, although a noticeable difference in the aging kinetics of the Ag3Sn particles present in the solder was observed. The growth rates of all intermetallics present in the solder joint were insignificant below 120°C. The results obtained were compared to earlier aging experiments involving eutectic tin-silver solder without any copper. It was found that the activation energy of the Cu6Sn5 intermetallic layer growth was about 10% less in the tin-silver solder joints with the small additions of copper added to the composition. Copper from the substrate tended to diffuse through the Cu-Sn intermetallic layer faster than tin from the solder.
Differential incidence in the presence of initial distorting taxes

Abstract This paper extends the two-sector, two-factor, general-equilibrium analysis of differential tax incidence by considering an initial situation where the government finances a fixed commodity bundle by distorting commodity and factor taxes. This alters the traditional analysis of marginal differential incidence in a fundamental way by necessitating the simultaneous determination of the change in the rental-wage ratio, the change in aggregate welfare and the change in an endogenously adjusting tax parameter. This contributes towards an integration of the study of the excess-burden effects and the distributional effects of a given tax situation.
Identification of calmodulin-binding proteins in chicken embryo fibroblasts.

We recently reported the detection of multiple classes of calmodulin-binding proteins in subcellular fractions of chicken embryo fibroblasts by using a gel binding procedure (Van Eldik, L.J., and W.H. Burgess, 1983, J. Biol. Chem., 258:4539-4547). In this report we identify many of these calmodulin-binding proteins and provide further evidence for the existence of multiple classes of calmodulin-binding proteins based on the interaction of these proteins with calmodulin and other calcium-modulated proteins. The fact that, in some cases, the same calmodulin-binding protein can bind troponin C and S100 alpha suggests that similar functional domains may be present in these distinct calcium-modulated proteins. We also have used protocols based on purification steps for calmodulin-binding proteins and calmodulin-regulated activities from other systems, in conjunction with enzymatic assays and various immunological methods, to identify many of the calmodulin-binding proteins in chicken embryo fibroblasts. The identities of these proteins suggest in vivo roles for calmodulin in the regulation of cell shape and motility, cyclic nucleotide metabolism, and possibly nucleic acid and protein turnover in fibroblasts.
Estimating sorption rates of hydrophobic organic compounds in iron oxide- and aluminosilicate clay-coated aquifer sands

We hypothesized that retarded diffusion in coatings controls the rate of sorption of hydrophobic organic compounds (HOCs) on quartzitic aquifer sands. Microscopic examination of three sands was used to quantify the coating thicknesses. With measures of the coatings' organic contents and porosities, we predicted the relative sorption rates for (a) multiple HOCs on one sand and (b) one HOC with three sands. The predicted relative rates and equilibrium coef ficients were assessed using observations of HOC transport through short sand columns operated at varying flow rates. We found that the column Kd values were always much less than predicted from Kocfoc or observed in batch tests. This suggests that diagenetically produced sorbents may include organic matter that is completely inaccessible for HOC sorption; procedures that disaggregate these sands could expose organic matter that does not sorb HOCs in the environment. Second, by modifying our retarded diffusion expectations with the inferred fraction of av...
The thermodynamics of proton hydration and the electrochemical surface potential of water

The free energy change for transferring a single ion across the water liquid/vapor interface includes an electrochemical surface potential contribution. Since this potential is not directly accessible to thermodynamic measurement, several extra-thermodynamic approaches have been employed to infer its sign and magnitude, with a resulting wide spread of values. Here, we examine further the thermodynamics of proton hydration and the electrochemical surface potential of water along three directions: (1) a basic relation of interfacial electrostatics and experimental results on ion distributions near a water/organic interface are employed to infer a solvent contribution to the electrochemical surface potential, (2) a re-analysis is performed of the existing bulk and cluster ion hydration data, and (3) extensive computational modeling is conducted to examine the size dependence of hydration enthalpy differences for the NaF ion pair between the small cluster and the converged bulk limits. The computational studies include classical polarizable models and high-level quantum chemical methods. The new theoretical analysis of existing experimental data and the combined classical/quantum modeling lead to results consistent with our previously derived proton hydration quantities.
“To be Shot at by the Whites and Dodged by the Negroes”: Lyndon Johnson and the Texas NYA

Although Lyndon B. Johnson's presidential record clearly established him as a committed champion of African American civil rights, the origins of this commitment remain less clear. This article examines LBJ's record as head of the Texas National Youth Administration (NYA) in the mid-1930s to argue that he demonstrated a genuine commitment to racial equality much earlier than many accounts suggest. Furthermore, in an attempt to offer a fuller understanding of the future president's civil rights views, it provides the first analysis of this period that places Johnson's record within a comparative framework that considers the performance of other Southern NYA programs at the same time.
Redox regulation of protein kinases

AbstractProtein kinases represent one of the largest families of genes found in eukaryotes. Kinases mediate distinct cellular processes ranging from proliferation, differentiation, survival, and apoptosis. Ligand-mediated activation of receptor kinases can lead to the production of endogenous hydrogen peroxide (H2O2) by membrane-bound NADPH oxidases. In turn, H2O2 can be utilized as a secondary messenger in signal transduction pathways. This review presents an overview of the molecular mechanisms involved in redox regulation of protein kinases and its effects on signaling cascades. In the first half, we will focus primarily on receptor tyrosine kinases (RTKs), whereas the latter will concentrate on downstream non-receptor kinases involved in relaying stimulant response. Select examples from the literature are used to highlight the functional role of H2O2 regarding kinase activity, as well as the components involved in H2O2 production and regulation during cellular signaling. In addition, studies demonstra...
Effects of systemic nicotine on serotonin release in rat brain.

We used in vivo microdialysis to examine the acute effects of systemically administered nicotine (0.8-8.0 mg/kg, s.c.) on extracellular levels of serotonin (5-HT) in the frontal cortex of awake rats and animals anesthetized with chloralose/urethane. In anesthetized animals, 5-HT efflux was elevated during the initial 15 min after nicotine administration (2-8 mg/kg), but then returned to baseline values. All of the effective nicotine doses also lowered and then raised blood pressure in these animals. However, other drugs which raised (methoxamine, 0.07 mg/kg, i.v.) or lowered (mecamylamine, 5 mg/kg, i.p.) blood pressure without directly activating nicotinic receptors failed to alter 5-HT release. Moreover, pretreatment with a centrally active dose of mecamylamine, a known nicotinic antagonist, blocked the effects of nicotine (4 mg/kg) on 5-HT release. For studies on awake rats the perfusion fluid also contained fluoxetine, since basal 5-HT levels were barely detectable without this uptake blocker. In such animals, 1.6 mg/kg of nicotine significantly increased 5-HT release, an effect apparent in the initial 20 min after treatment and persisting for at least 2 h. These observations demonstrate that systemically administered nicotine increases frontocortical 5-HT release, that this effect is independent of the cardiovascular responses to the drug, and that it probably results from the activation of previously described nicotinic receptors on raphe neurons. The present findings are consistent with the hypothesis that the appetitive and mood disturbances associated with nicotine withdrawal may be mediated by diminished serotoninergic transmission.
Breaking boundaries and barriers: Future directions in cross‐cultural research

Abstract The level and degree of understanding of the nature and meaning of leisure in the lives of blacks, native‐Americans, Hispanics, and other ethnic minority populations within the United States is lacking. Most research to date has utilized a social aggregate approach to the study of ethnic/racial differentiation; such research overlooks the dynamics and complexity of ethnicity within poly‐ethnic, pluralistic societies. The objectives of this article are: 1) to present an overview of the types of research which have been conducted among ethnic/racial populations within the U.S., 2) to discuss several ideological and theoretical assumptions which underlie such approaches, and 3) to present several alternative theoretical and methodological approaches which might prove more meaningful in attempts to understand the dynamics of cultural diversity.
Synchronization of hyperventilation with stimulus frequency

Abstract If the temporal pattern of chemical changes in the arterial blood is important in determining respiratory responses, and if such fluctuations are translated into nonpropagated potentials capable of modulating respiratory neural activity, then neural structures should exist which can respond to oscillating potentials of appropriate time course. By polarizing the rat medulla with biased sinusoidal currents, an hyperpnea characterized by the synchronization of respiratory rate with stimulus frequency was obtained. Responsive areas were localized to a small volume in the ventral reticular formation, corresponding to the location of the inspiratory and expiratory centers. The hyperpnea was immediate in onset and cessation with the stimulus. Respiration synchronized with current frequencies between 0.1 and 8 cycles/sec. Certain electrical patterns produced ventilations eight times the ventilation of resting animals. Decreased Paco 2 always resulted, indicating hyper ventilation. Small increases in O 2 consumption resulted, which were probably related to increased work of breathing. The area localized exhibited properties consistent with its being considered a participant in the coordination and control of respiratory rhythmicity, rate and amplitude.
Electron Density Profiles of Nerve Myelin

THE structure of the nerve membranes within the myelin sheath of frog sciatic nerve has been studied by low-angle X-ray diffraction. Many additional orders of diffraction have been recorded from nerve, and, from a structure analysis of this new X-ray data, a twelve-parameter electron density model is proposed. Fourier series representations of the one-dimensional electron density of live nerve myelin at two different resolutions are also presented; these resolutions are 7 A and 4.8 A.
Energy Harvesting by Vibrations With MEMS Piezoelectric Benders

Piezoelectric micro benders are fabricated and tested to demonstrate energy generating performance. Trapezoidal and diagonal unimorph PZT benders with an interdigitated electrode pattern are utilized. The d33 mode design is beneficial for the micro energy harvesting devices because it can generate higher voltage than that of the d31 mode design. It can also eliminate a bottom electrode by only using an interdigitated top electrode which facilitates fabrication, as opposed to the d31 mode design that requires both top and bottom electrodes. The MEMS benders consist of layers of SiO2 /SiNx /ZrO2 /PZT, and a top Au/Cr interdigitated electrode. The experimental results indicate that the fundamental frequencies of the micro benders are about 9.1 kHz for the trapezoidal bender and 18.48 kHz for the diagonal bender, respectively. The micro trapezoidal bender can generate power of approximately 1.4μW into a 680 kΩ resistive load at the resonant frequency. The diagonal bender can generate power of about 18.2 μW into a 100 kΩ resistive load at the resonant frequency.Copyright © 2009 by ASME
Culture of Dermatophytes Upon Stratum Corneum

An in vitro method of culturing dermatophytic spores on stratum corneum alone is described. The stratum corneum is stripped onto a translucent adhesive tape and fixed to a microscope slide. Spores are applied and the tape is incubated under controlled conditions. The technique has been made semiquantitative and applied to the study of a topical anti- fungal agent.
Stratification of alpha ganglion cells and ON/OFF directionally selective ganglion cells in the rabbit retina

The correlation between cholinergic sensitivity and the level of stratification for ganglion cells was examined in the rabbit retina. As examples, we have used ON or OFF α ganglion cells and ON/OFF directionally selective (DS) ganglion cells. Nicotine, a cholinergic agonist, depolarized ON/OFF DS ganglion cells and greatly enhanced their firing rates but it had modest excitatory effects on ON or OFF α ganglion cells. As previously reported, we conclude that DS ganglion cells are the most sensitive to cholinergic drugs. Confocal imaging showed that ON/OFF DS ganglion cells ramify precisely at the level of the cholinergic amacrine cell dendrites, and co-fasciculate with the cholinergic matrix of starburst amacrine cells. However, neither ON or OFF α ganglion cells have more than a chance association with the cholinergic matrix. Z-axis reconstruction showed that OFF α ganglion cells stratify just below the cholinergic band in sublamina a while ON α ganglion cells stratify just below cholinergic b. The latter is at the same level as the terminals of calbindin bipolar cells. Thus, the calbindin bipolar cell appears to be a prime candidate to provide the bipolar cell input to ON α ganglion cells in the rabbit retina. We conclude that the precise level of stratification is correlated with the strength of cholinergic input. Alpha ganglion cells receive a weak cholinergic input and they are narrowly stratified just below the cholinergic bands.
Patient Education vs. Patient Experiences of Self-advocacy: Changing the Discourse to Support Cancer Survivors

A growing emphasis on patient self-advocacy has emerged in the public discourse on cancer survivorship. This discourse shapes patients' conceptualizations about self-advocacy and in turn influences their health care attitudes and behaviors. The purpose of this discourse analysis is to explore the language of self-advocacy by comparing a published self-advocacy guide with the lived experiences of women with ovarian cancer. Data sources include (1) a self-advocacy patient education guide published by the National Coalition for Cancer Survivorship and (2) transcripts of focus groups conducted with ovarian cancer survivors. Discourse analysis techniques were used to take a close look at the language used by both to uncover the meaning each group ascribed to self-advocacy. Challenges and inconsistencies were noted between the patient education guide and transcripts including viewing self-advocacy as a skill set to assert one's needs as opposed to a means by which to preserve a positive attitude and maintain a trusting relationship with health care providers, respectively. Some women saw themselves as self-advocates yet struggled to locate relevant health information and hesitated to upset their relationship with their health care providers. This analysis highlights tensions between the discourses and points to ways in which patient education materials can be adjusted to support cancer survivors in advocating for their needs according to their unique situations and preferences.
Who Serves? Predicting Placement of Management Graduates on Nonprofit, Government, and Business Boards

The authors elaborate on our understanding of the use of the labor market of individuals with MBA and MPA degrees for service on boards. They find that individuals are most likely to have board ser...
The BIG system - synergetic graphics

The recent decrease in the cost of graphics hardware has created an expanded potential opportunity for the use of graphic techniques. However, this potential is reduced by a lack of agreement on the software interface for this graphics environment. In almost every forum that discusses graphical techniques, new systems are introduced that are syntactically unique, but semantically very similar2,8,16. One of the major reasons for this proliferation of graphic systems is the large number of possible tradeoffs that exist between the performance parameters of these devices. Each graphics system can be optimized for a limited number of these parameters by adjusting a feature of the system design until the best results are obtained. Where more than one design feature affects a particular performance parameter, the system designer usually selects a single feature for adjustment and restricts the user's ability to modify any others. The users discover that they cannot adequately adjust that graphics system for their particular problem, leading to the creation of yet another graphics system.An evaluation of the techniques that have been used to provide this design factor optimization reveal that applying these techniques in combination provides a greater degree of user control over the graphics environment. This synergetic behavior leads to benefits that can be derived from a graphics system that allows the user a greater variety of implementation options. This flexibility will also allow the user to somewhat compensate for the present lack of a graphics standard. A system that utilizes this methodology is described and examples of its application are shown.
Effects of prostaglandins and indomethacin on neuromuscular blocking agents

The effects on neuromuscular blockade by d-tubocurarine and succinylcholine of inhibition of prostaglandin biosynthesis by indomethacin and of intra-arterial administration of prostoglandins E2 and F2alpha, before and after inhibition of prostoglandin biosynthesis, were evaluated in the cat sciatic-tibialis preparation. Non-specific inhibition of prostaglandin biosynthesis by indomethacin 3 mg kg-1 did not alter latency, maximal blockade or duration of neuromuscular blockade induced by d-tubocurarine or succinylcholine. Prostaglandin E2 antagonized twitch height depression by d-tubocurarine by an average of six percent before and by 15 percent after indomethacin, but potentiated the neuromuscular block of succinylcholine by an average of five per cent before and 60 per cent after indomethacin. Prostaglandin F2alpha antagonized d-tubocurarine neuromuscular block by an average of 10 per cent before and 18 per cent after indomethacin, but potentiated succinylcholine block by an average of four per cent before and 12 per cent after indomethacin. These results suggest that non-specific inhibition of prostaglandin biosynthesis alone does not influence d-tubocurarine or succinylcholine induced neuromuscular blockades. However, both prostaglandin E2 and F2alpha may induce transmitter release at the neuromuscular junction that may be enhanced by indomethacin, thus antagonizing the non-depolarizing blockade of d-tubocurarine and potentiating the depolarizing blockade of succinylcholine.
Depolarized interferometer fiber optic gyro with improved polarization error suppression

We describe sources of polarization errors in depolarized IFOGs and methods for enhancing their suppression. A test-gyro circuit and associated experimental results showing 0.1 degree/hour (one-sigma) open-loop bias stability over a thermally dynamic environment are presented.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
THE LAST OF LIFE: PSYCHOLOGICAL REFLECTIONS ON OLD AGE AND DEATH

A long-retired psychoanalyst considers his old age and bereavement and the brief span of life remaining. The greater imminence of death now than at any earlier time in life calls for more than currently available satisfactions, however rewarding they may be. Seeing life as a whole is now a possibility, while the death of his wife reveals more than ever their interrelatedness as a pair and strengthens the hope of continuity.
Quantitative cerebral MR perfusion imaging: Preliminary results in stroke

Purpose To evaluate quantitative cerebral blood flow (qCBF) with traditional time-based measurements or metrics of cerebral perfusion: time to peak (Tmax) and mean transit time (MTT) in stroke patients. Materials and Methods Nine ischemic stroke patients (four male, five female, 63 ± 16 years old) were included in the study which was Health Insurance Portability and Accountability Act compliant and institutional review board approved. Cerebral perfusion was quantified using the Bookend method. Mean values of qCBF, Tmax, and MTT were determined in regions of interest (ROIs). ROIs were drawn on diffusion weighted images in diffusion positive, critically ischemic (CI), in ipsilateral normal region immediately surrounding the critically ischemic region, the presumed penumbra (PP), and in contralateral diffusion negative control, presumed normal region (PN) of gray and white matter separately (GM and WM). Results In both GM and WM, qCBF measures distinguished the studied brain regions with the most markedly reduced values in regions corresponding to extent of likely ischemic injury. In planned comparisons, only qCBF measurements differed significantly between CI and PP tissues. ROC analysis supported the utility of qCBF for discriminating brain regions differing in the likely extent of ischemic injury (CI and PN regions – qCBF: area under the curve [AUC] = 0.96, Tmax: AUC = 0.96, MTT: AUC = 0.72). Importantly, qCBF afforded the best discrimination of CI and PP regions (qCBF: AUC = 0.82, Tmax: AUC = 0.65, MTT: AUC = 0.52). Conclusion This initial evaluation indicates that quantitative MRI perfusion is feasible in ischemic stroke patients. qCBF derived with this strategy provide enhanced discrimination of CI and PP compared to time-based imaging metrics. This approach merits investigation in larger clinical studies. J. Magn. Reson. Imaging 2010;32:796–802. © 2010 Wiley-Liss, Inc.
Relation of pulmonary responses induced by 6.6-h exposures to 0.08 ppm ozone and 2-h exposures to 0.30 ppm ozone via chamber and face-mask inhalation.

While direct comparison of pulmonary responses to 6.6-h exposures to 0.08 to 0.12 ppm ozone (O 3) have demonstrated that chamber and face-mask inhalation methods yield closely similar results, no comparative study of responses to 2-h intermittent exercise (IE) exposures to higher O 3 concentrations have been reported. The present study was designed to achieve three primary objectives: (1) to compare pulmonary function and symptoms effects of a 2-h IE exposure to 0.30 ppm O 3 via chamber and via face mask; (2) to compare the pulmonary effects of 6.6-h chamber exposure to 0.08 ppm O 3 to those observed in 2-h IE 0.30 ppm O 3 exposures via chamber and via face mask; and (3) to examine filtered air (FA) recovery pulmonary and symptoms responses following chamber exposures of 6.6 h to 0.08 ppm O 3 and 2 h to 0.30 ppm O 3. A simple regression of postexposure percent change in FEV 1.0 for the 2-h IE, 0.30-ppm O 3 chamber exposure as a function of postexposure percent change in FEV 1.0 for the 2-h IE, 0.30-ppm O ...
Site-directed mutagenesis of lysine 58 in a putative ATP-binding domain of the calmodulin-sensitive adenylate cyclase from Bordetella pertussis abolishes catalytic activity.

Abstract A 2.7-kb cya A gene fragment encoding the amino-terminal end of the calmodulin-sensitive adenylate cyclase from Bordetella pertussis has been placed under the control of the lac promoter for expression in Escherichia coli. Following induction with isopropyl beta-D-thiogalactoside, calmodulin-sensitive adenylate cyclase activity was detected in a cell extract from E. coli. The expression vector directed the synthesis of a 90-kDa polypeptide that was recognized by rabbit polyclonal antibodies raised against the catalytic subunit of B. pertussis adenylate cyclase. Inspection of the deduced amino acid sequence of the cya A gene product revealed a sequence with homology to consensus sequences for an ATP-binding domain found in many ATP-binding proteins. On the basis of the analysis of nucleotide binding proteins, a conserved lysine residue has been implicated in the binding of ATP. A putative ATP-binding domain in the B. pertussis adenylate cyclase possesses an analogous lysine residue at position 58. To test whether lysine 58 of the B. pertussis adenylate cyclase is a crucial residue for enzyme activity, it was replaced with methionine by oligonucleotide-directed mutagenesis. E. coli cells were transformed with the mutant cya A gene, and the expressed gene product was characterized. The mutant protein exhibited neither basal nor calmodulin-stimulated enzyme activity, indicating that lysine 58 plays a critical role in enzyme catalysis.
ON THE ANOMALOUS INTERACTIONS OF LIGANDS WITH RHODOSPIRILLUM HAEM PROTEIN.

Abstract The spectroscopic responses of Rhodospirillum rubrum haem protein to a variety of ligands over the pH range 5.2–12 have been examined. Only small uncharged molecules, e.g. , NO and CO, are able to penetrate to the prosthetic haem groups of the protein. NO reacts not as a ligand, however, but causes changes which appear to be the result of oxidative alterations either of the porphyrin moeities or a reactive groups in the immediate peptide environment, or of both. CO, on the other hand, reacts as a true ligand. However, the affinity of rhodospirillum haem protein for CO is much less than that of most other haem proteins; the half-saturation value for ferro-rhodospririllum haem protein-CO formation is about 0.015 atm at all pH values tested. The atypical variation in photodissociability of ferro-rhodospirillum haem protein-CO with pH, noted previously, is confirmed.