cssi/SciSciGPT-SciSciNet huggingface dataset:
Construction of three-dimensional black-hole initial data via multiquadrics.

Numerical solutions of the 3+1 Hamiltonian constraint equation for single-black-hole initial data are presented. When expressed in Cartesian coordinates the solutions for the conformal factor are fully three-dimensional (3D), and therefore the approach described here can straightforwardly produce initial data for two or more black holes with arbitrary positions, spins, and linear momenta. The numerical method we use is known as the multiquadric approximation scheme, in which a continuous function, {ital f}, is written as {ital f}({ital x},{ital y},{ital z})={ital a}{sub 1}+ {ital tsum}{sub {ital j}=2}{sup {ital N}} a{sub {ital j}{tilde g}{ital j}}({ital x},{ital y},{ital z}), where the {ital a}{sub {ital j}}'s are constants, the {ital {tilde g}}{sub {ital j}}'s are radial basis functions (multiquadrics), and {ital N} is the total number of grid points used. Despite numerical problems with ill-conditioning of the matrix, with care the method is capable of producing highly accurate results and it has a number of distinct advantages over finite-difference methods for problems with complicated boundaries, as is the case here. Typically we can reproduce the York-Bowen analytic solution for a boosted black hole to less than 0.5% maximum error with {ital N}=1057 in 3D. Where no analytic solutions exist comparisons of our 3D resultsmore » with previous axisymmetric 2D numerical calculations show very good agreement.« less
Initiation of meiotic recombination by formation of DNA double-strand breaks: mechanism and regulation

Homologous recombination is essential for accurate chromosome segregation during meiosis in most sexual organisms. Meiotic recombination is initiated by the formation of DSBs (DNA double-strand breaks) made by the Spo11 protein. We review here recent findings pertaining to protein-protein interactions important for DSB formation, the mechanism of an early step in the processing of Spo11-generated DSBs, and regulation of DSB formation by protein kinases.
Increased brain neuropeptide Y1 and Y2 receptor binding in NPY knock out mice does not result in increased receptor function.

Abstract The brain neuropeptide Neuropeptide Y (NPY) is an important modulator of a number of centrally mediated processes including feeding, anxiety-like behaviors, blood pressure and others. NPY produces its effects through at least four functional G-protein coupled receptors termed Y1, Y2, Y4 and Y5. In the brain, the Y1 and Y2 receptor subtypes are the predominant receptor population. To better understand the roles of NPY, genetically modified mice lacking NPY were produced but lacked the expected phenotypes. These mice have previously been reported to have a marked increase in Y2 receptor binding. In the present study, we found an upregulation of both Y1 and Y2 receptor binding and extended these findings to the female. These increases were as large as 10-fold or greater in many brain regions. To assess functional coupling of the receptors, we performed agonist-induced [ 35 S]GTPγS autoradiography. In the mouse brain, the Y1/Y4/Y5 agonist Leu 31 ,Pro 34 -NPY increased [ 35 S]GTPγS binding with a regional distribution consistent with that produced when labeling adjacent sections with [ 125 I]-Leu 31 ,Pro 34 -PYY. In a few brain regions, minor increases were noted in the agonist-induced binding when comparing knock out mice to wild type. The Y2 agonist C2-NPY stimulated [ 35 S]GTPγS binding in numerous brain areas with a regional distribution similar to the binding observed with [ 125 I]-PYY3-36. Again, no major increases were noted in the functional activation of Y2 receptors between knock out and wild type mice. Therefore, the increased Y1 and Y2 binding observed in the NPY knock out mice does not represent an increase in NPY receptor mediated signaling and is likely due to an increase in spare (uncoupled) receptors.
Forecasting radiation rates and exposure from multi-aged fallout

A graphical method for forecasting radiation exposure rates from multi-aged fallout is extended to include a nomogram method. A simple method for forecasting accumulated radiation exposure is also presented. It is shown mathematically that these methods can provide estimates of radiation exposure rates or cumulative exposures for intervals of a few days to a few weeks in the future to within +/- 30% from assumed actual radiation exposure rates or accumulated exposures for fallout that decays according to t-n, where n is any number from 0.8 to 1.6. Because of the self-adjusting feature of the method which results in an estimated effective age for the fallout, it is not necessary to attempt to subtract contributions from separate fallouts with different ages. The method can be applied to composite fallout without knowledge of the previous history of the various-aged contributions.
Quantum-optical properties of polariton waves

We develop a quantum-mechanical Hamiltonian formulation to treat the polariton in the framework of quantum optics. We exploit two specific Hamiltonians: the conventional Hopfield model, and a more general Hamiltonian. For both of these, exciton-polariton quantum states are found to be squeezed (intrinsic polariton squeezing) with respect to states of an intrinsic, nonpolaritonic, mixed photon-exciton boson. The amount and duration of intrinsic squeezing during the polariton period are calculated for exciton polaritons in typical I-VII and III-V semiconductors. Among the noteworthy features is the possibility of tuning the amount of intrinsic squeezing by varying the frequency--wave-vector dispersion of the polariton mode. We further analyze the photon statistics of the electromagnetic component of the polariton. Tunable non-Poissonian photon statistics and squeezing (optical polariton squeezing) are found in the radiative component of the exciton polariton. This entails the reduction of the fluctuations of the polariton electromagnetic field component below the limit set by the vacuum fluctuations. The Mandel Q factor for the number distribution of photons in a polariton coherent state has been evaluated. Although small, for I-VII and III-V materials in the range of modes analyzed, the Q factor could be enhanced for phonon polaritons as well as for other materials. Interpretations of the origin of squeezing in polariton states are presented.
Idiopathic Sudden Sensorineural Hearing Loss

A healthy 58-year-old woman answers the telephone and realizes that her hearing is diminished on the left side. She notices aural fullness and loud tinnitus in the affected ear. Self-administered ear cleaning with the use of an over-the-counter kit does not relieve the symptoms. How should she be evaluated and treated?
Characterization of buried-nitride silicon for integrated circuit applications

We have examined the microstructure and the transport properties of nitrogen-implanted silicon-on-insulator wafers, as well as the performance of integrated-circuit transistors fabricated in this material. The insulating regions were fabricated in silicon by the unpatterned implantation of 4x10/sup 17//cm/sup 2/, 300 keV nitrogen dimers followed by annealing at 1473/sup 0/K for 5 hours. For these parameters, the buried nitrogen-implanted layer crystallized into ..cap alpha..-silicon nitride, and contains approx. =20% excess silicon in the form of silicon inclusions of 5 to 15 nm diameter. The surface silicon layers are characterized by low-mobility, p-type conduction. The buried dielectric has a resistivity of approximately 10/sup 8/ ..cap omega..-cm. Functional p-channel, integrated circuit transistors have been fabricated in n-type epitaxial silicon gorwn over the buried-nitride wafers. These transistors devices are similar in performance to those fabricated in bulk silicon, (hole mobilities in inversion layers of 140 cm/sup 2//V-s), and demonstrate the suitability of the buried nitride process for integrated circuit applications.
SU‐FF‐T‐456: What Is the Optimal Source‐To‐Collimator Distance for An Extendible MLC Designed for Energy‐ and Intensity‐Modulated Electron Radiation Therapy of Superficial Tumors

Purpose: To determine an optimal source‐to‐collimator distance (SCD) for an extendible multi‐leaf collimator (exMLC) designed for energy‐ and intensity‐modulated electron radiotherapy for superficial tumors.Method and Materials: To implement an extendible Modulated Electron Radiation Therapy (exMERT) technique for optimized radiotherapy of superficial tumors, we designed a virtual exMLC and investigated the effect of SCD on the characteristics of resulting electron beams. An exMLC made of tungsten leaves of 15 mm thickness and 5 mm width and with straight leaf ends was modeled as a MLC component module in EGS4/BEAM simulations. Phase space files were scored at the back surface of the exMLC and at 100 cm SSD for 6 to 20 MeV electron beams emerging from a Varian Clinac 21EX treatment head equipped with exMLC located at SCDs of 85, 90 and 95 cm. These phase space files were then analyzed using BEAMDP and used as beam input for further dose calculations in water. Results: At shorter SCD (85 cm), the in‐air scatter and dose overlapping at depth were the worst compared to other SCDs. The 80–20 penumbra of 1 cm × 1 cm beamlet was 0.92 cm at 100 cm SSD and 1.35 cm at 2 cm depth in water for 6 MeV beam. On the other hand, the leaf scatter and leakage from the exMLC located at 95 cm SCD resulted in larger bremsstrahlung photondose (∼4% of maximum dose for 20 MeV electrons). Overall, the exMLC at 90 cm SCD yielded modest leaf scatter and leakage as well as dose overlapping at depths, acceptable to clinical applications of exMERT with good clearance for patient setups. Conclusions: Based on the consideration of beam penumbra, photon contamination, and patient clearance, the SCD of 90 cm was determined to be the best compromise for exMLC to be used in exMERT.
Expression of purinergic receptor channels and their role in calcium signaling and hormone release in pituitary gonadotrophs. Integration of P2 channels in plasma membrane- and endoplasmic reticulum-derived calcium oscillations.

The role of ATP as a positive feedback element in Ca2+ signaling and secretion was examined in female rat pituitary gonadotrophs. ATP and ADP, but not AMP or adenosine, induced a dose- and extracellular Ca2+-dependent rise in [Ca2+]i in identified gonadotrophs in a Mg2+- and suramin-sensitive manner. ATP, adenosine-5′-O-(3-thiotriphosphate), adenosine-5′-O-(1-thiotriphosphate), 2-methylthio-ATP, and 3′-O-(4-benzoyl)benzoyl-ATP were roughly equipotent in rising [Ca2+]i in gonadotrophs, while ADP was effective only at submillimolar concentration range, and none of these compounds permeabilized the cells. On the other hand, α,β-methylene-ATP, β,γ-methylene-ATP, and UTP were unable to induce any rise in [Ca2+]i. This pharmacological profile is consistent with expression of P2X2 and/or P2X5 purinergic receptor channels. Patch-clamp experiments showed that ATP induced an inward depolarizing current in gonadotrophs clamped at −90 mV, associated with an increase in [Ca2+]i. The ATP-induced [Ca2+]i response was partially inhibited by nifedipine, a blocker of voltage-sensitive Ca2+ channels (VSCC), but was not affected by tetrodotoxin, a blocker of voltage-sensitive Na+ channels. Thus, the P2-depolarizing current itself drives Ca2+ into the cell, but also activates Ca2+ entry through VSCC. In accord with this, low [ATP] induced plasma membrane-dependent [Ca2+]i oscillations in quiescent cells, and increased the frequency of spiking in spontaneously active cells. ATP-induced Ca2+ influx also affected agonist-induced and InsP3-dependent [Ca2+]i oscillations by increasing the frequency, base line, and duration of Ca2+ spiking. In addition, ATP stimulated gonadotropin secretion and enhanced agonist-induced gonadotropin release. ATP was found to be secreted by pituitary cells during agonist stimulation and was promptly degraded by ectonucleotidase to adenosine. These observations indicate that ATP represents a paracrine/autocrine factor in the regulation of Ca2+ signaling and secretion in gonadotrophs, and that these actions are mediated by P2 receptor channels.
Optimal laser parameters for port wine stain therapy: a theoretical approach.

The optimal parameters for laser therapy of port wine stains (PWS) have been deduced from temperature calculations on two models: (i) the four-layer model; and (ii) the tube model in which two plane parallel layers, representing the epidermis and dermis, and a dermal rectangular blood vessel are considered. The calculations were performed with a vessel of average cross section 0.06 mm*0.08 mm located in the centre of the laser beam. The numerical calculations were performed by an alternate direction-implicit finite difference method. The optimal parameters were: wavelengths lambda =415, 577 and 540 nm; pulse time, 1 ms 0.1 mm. The energy densities E1 (for t1=1 ms) required to coagulate blood vessels down to a depth of 0.65 mm in order to establish bleaching of the PWS were 0.5, 1.6 and 2 Jcm-2 for the different lambda respectively. The value for the argon laser ( lambda =488 and 514.5 nm) was E1=6.5 J cm-2 (t1=1 ms). Because, for this pulse time, heat summation effects at the boundary of the laser beam cause no drastic increase in local temperature at optimal wavelengths, the stripe technique was again considered and compared with the separated spot technique. The Nd-YAG and CO2 lasers prove even less selective than the argon laser. The influence of cooling the skin with water shows that only for lambda =577 nm and t1=0.1 s is there an increase in E1 from 2.5 to 6 J cm-2 for which dermal damage occurs.
Linear stability analysis of cone and plate flow of an Oldroyd-B fluid

Abstract A linear stability analysis of the cone and plate flow of an Oldroyd- B fluid is carried out. We show that the base flow is stable to a class of axisymmetric perturbations provided that the Deborah number is less than a critical value and that at the critical value there is exchange of stability. The value of the critical Deborah number for both creeping and non-creeping flow is obtained. The critical value of the Deborah number at which instability is predicted for non-creeping flows is shown to be less than the value for creeping flows, indicating that inertia is destabilizing.
Glass microstructure characterization by lazer light scattering, small angle X-ray scattering and electron microscopy

Transmission electron microscopy (TEM), small angle X-ray scattering (SAXS) and laser light scattering (LLS) have been used to characterize the microstructures of mixed alkali-lithia-potassia-silica glasses and soda lime silica glasses. In most cases the three methods complement one another very well. In the mixed alkali silicate glasses LLS measurements of particle size correlate very well with TEM measurements. In addition, there is a direct correlation between particle size measurements by both methods and flaw sizes calculated from strength measurements using the Griffith equation. In the soda lime silica system LLS measurements of the glasses prior to heat treatment in the temperature region of metastable liquid immiscibility correlate very well with SAXS measurements of the heat treated glasses. The merits of each method in studies involving these glass systems will be discussed.
Designer selves: construction of technologically mediated identity within graphical, multiuser virtual environments

The emergence of graphical, multiuser virtual environments has created new forums for the performance of identity, forums in which information system designers' decisions may influence people's presentation of self. Based on ethnographic research, this paper describes designers' actions affecting identity performance within graphical virtual environments, and the manner in which those decisions interact with larger social contexts of dominance based on race, class, and gender. I make explicit the social consequences of designer's decisions, in order to further the dialogue between social scientists and technologists, and make suggestions regarding how designers may approach the construction of virtual environments without unwittingly contributing to patterns of dominance in society.
Two-dimensional Fourier transform ESR in the slow-motional and rigid limits: 2D-ELDOR *

Abstract The two-dimensional Fourier transform ESP techniques of stimulated SECSY and 2D-ELDOR are shown to be powerful methods for the study of slow motions for nitroxides. Stimulated SECSY provides magnetization transfer rates, whereas 2D-ELDOR displays how the rotational motions spread the spins out from their initial spectral positions to new spectral positions, as a function of mixing time. The role of nuclear modulation in studies of structure and dynamics is also considered.
ISOLATION AND CHARACTERIZATION OF THE MAJOR PROTEIN FROM GREAT NORTHERN BEANS (PHASEOLUS VULGARIS)

The major protein of Great Northern beans was isolated through salt extraction, ammonium sulfate fractionation, gel filtration and DEAE-cellulose ion exchange chromatography. Physicochemical properties of the major bean protein were determined. Results from heat stability studies showed that the protein was the most stable at pH values between 4 and 6. A complete unfolding of the bean protein was not essential in order to improve its digestibility. The native protein had a compact structure and therefore was resistant to the attack by proteolytic enzymes. A glycopeptide containing a N-glycosidic protein-carbohydrate linkage, isolated from a protease digestion of the major bean protein was also characterized. Results implied that the carbohydrate moeity might have a negative influence on the digestibility of the native protein.
The annual cycle of stratospheric water vapor in a general circulation model

The application of general circulation models (GCM's) to stratospheric chemistry and transport both permits and requires a thorough investigation of stratospheric water vapor. The National Center for Atmospheric Research has redesigned its GCM, the Community Climate Model (CCM2), to enable studies of the chemistry and transport of tracers including water vapor; the importance of water vapor to the climate and chemistry of the stratosphere requires that it be better understood in the atmosphere and well represented in the model. In this study, methane is carried as a tracer and converted to water; this simple chemistry provides an adequate representation of the upper stratospheric water vapor source. The cold temperature bias in the winter polar stratosphere, which the CCM2 shares with other GCM's, produces excessive dehydration in the southern hemisphere, but this dry bias can be ameliorated by setting a minimum vapor pressure. The CCM2's water vapor distribution and seasonality compare favorably with observations in many respects, though seasonal variations including the upper stratospheric semiannual oscillation are generally too small. Southern polar dehydration affects midlatitude water vapor mixing ratios by a few tenths of a part per million, mostly after the demise of the vortex. The annual cycle of water vapor in the tropical and northern midlatitude lower stratosphere is dominated by drying at the tropical tropopause. Water vapor has a longer adjustment time than methane and had not reached equilibrium at the end of the 9 years simulated here.
Effects of a dairy–yeast prebiotic and water hardness on the growth performance, mineral composition and gut microflora of fathead minnow (Pimephales promelas) in recirculating systems

Abstract We conducted concurrent 8-week feeding trials with fathead minnow (FHM) (Pimephales promelas) fed diets with 0 or 2% dairy–yeast prebiotic in recirculating systems with low (LOW, 35 mg CaCO3 per L water) or moderate (MOD, 141 mg CaCO3 per L water) hardness to determine the effects of the prebiotic and water hardness on general performance, whole-body ash and mineral concentrations, and composition of the gastrointestinal (GI) microflora. Twenty-five fish with mean (± SE) individual weights of 0.34 ± 0.002 g were stocked into each of 4 replicate 110-L tanks per diet per system. Fish were fed to satiation twice daily on weekdays and once daily on weekends. Average individual weight gain (0.89–0.91 g) was higher and feed conversion (2.6–3.1 g) was lower in fish in the MOD system, than weight gain (0.54–0.55 g) and FCR (4.1–4.6) of FHM in the LOW system. Feed conversion was also lower in fish fed the prebiotic diet (2.6–4.1) than the basal diet (3.1–4.6). Survival of FHM (94–97%) was similar among treatments. Whole-body ash was higher in fish from the MOD system (7.9–8.4%) than the LOW system (6.7–7.7%) regardless of diet. Potassium was higher in FHM from the MOD system (9.78–10.07 g per kg diet) than the LOW system (9.45–9.52 g per kg diet), while sodium, iron, zinc and copper were higher in fish from the LOW system. Sodium was lower in FHM fed the prebiotic diet (2.39–2.73 g per kg diet) than the basal diet (2.42–3.42 g per kg diet). The GI microflora contained 626 different species. The Shannon–Wiener (S–W) index of diversity for GI microflora (genus level) was higher in FHM from the MOD system (3.29) than the LOW (2.12) system, but the S–W indices were similar for the basal (2.95) and PREB (2.45) diets. Acinetobacter was more abundant in the microflora of FHM fed the prebiotic diet than the basal diet. The mineral composition of the water had the strongest influence on FHM performance and the GI microflora, and the prebiotic did not increase mineral concentrations in fish fed diets with complete mineral mixes in the LOW or MOD system.
The role of a minor groove spine of hydration in stabilizing poly(dA).poly(dT) against fluctuational interbase H-bond disruption in the premelting temperature regime.

Abstract Experimental estimates of the premelting Adenine-Thymine base pair opening probability for some B-DNA sequences are two orders of magnitude smaller than those of other B-DNA sequences. The AT pairs in the sequence with smaller open probability seem to be those that have a well defined spine of hydration in the minor groove. We show that this spine of hydration can significantly enhance the thermal stability of the base pairs to which they are attached. The effect of this spine of hydration coupled with the possible stabilization effect contributed from neighboring GC pairs can explain the differences in the observed AT pair opening probability for different AT containing B-DNA sequences.
Structure of Bubbly Round Condensing Jets

Injection de bulles de CO 2 dissoutes dans l'eau, dans de l'eau au repos. Mesure des vitesses de phase moyennes et fluctuantes, du diametre moyen des bulles, de l'intensite moyenne du nombre de bulles et de la concentration moyenne de CO 2 dissous; la methode theorique qui permet d'interpreter les mesures doit prendre en compte la vitesse finie de transport de l'interphase et la dispersion turbulente des bulles
Receptor tyrosine phosphatases: The worm clears the picture

Recent work on the Caenorhabditis elegans clr-1 gene shows that the receptor tyrosine phosphatase that it encodes negatively regulates a receptor tyrosine kinase related to mammalian fibroblast growth factor receptors. This opens up a promising system for investigating receptor tyrosine phosphatase function.
Mapping the Research Questions in Technical Communication

Agreement about research questions can strengthen disciplinary identity and give direction to a field that is still maturing. The central research question this article poses foregrounds texts, broadly defined as verbal, visual, and multimedia, and the power of texts to mediate knowledge, values, and action in a variety of contexts. Related questions concern disciplinarity, pedagogy, practice, and social change. These questions overlap and inform each other. Any single study does not necessarily fall exclusively into one area. A mapping of a field's research questions is a political act, emphasizing some questions and marginalizing or excluding others. The emphases may change over time. This mapping illustrates reasons for the tensions between the academic and practitioner areas of the field. It also points out their shared research interests and opportunities for future research.
Structure of Shear Lines near the Tropopause in Summer

A detailed study is made of a shear line in the tropopause region. A summer case was purposely selected, in which the lower half of the atmosphere was relatively barotropic, in order to minimize the role that could possibly be played by a subsiding cold air mass in producing a vertical stretching and consequent concentration of vorticity in the higher atmosphere. During the period studied, the circulation over North America was characterized by the existence of two distinct jet streams, the southernmost of which, though initially having the form of a sinusoidal trough, appears to “buckle”, forming a very sharp trough separating two jet streams of opposite direction. A possible mechanism is suggested for the production of strong northerly flow leading up to shear-line formation, which depends upon a mutual interaction between the mass and velocity fields of the jet-stream systems located at different latitudes. An attempt to determine whether potential absolute vorticity is conserved during formation of the shear line is not wholly conclusive, but indicates a reasonable possibility that vorticity may be generated in the free atmosphere. DOI: 10.1111/j.2153-3490.1951.tb00793.x
Assembly Configurations of Spatial Single-Loop Single-DOF Mechanisms

This paper examines the problem of finding the assembly configurations (ACs), also called circuits, of spatial single-loop single-DOF mechanisms. All six lower pairs are considered: revolute (R), cylindric (C), prismatic (P), helical (H), spheric (S), and planar (E). The RSSR, CSS, RRSC, CCS, and RRSRR mechanisms are covered, along with all variations in which an R joint is replaced with a P or H joint, or an S joint is replaced with an E joint. The RRCRC, RRRCC, and RRRRCR mechanisms are covered, along with all appropriate variations in which an R joint is replaced by a P or H joint. A numerical method is given to _find the ACs, and is illustrated with several examples.
Optical theorem and effective finite-range nuclear interaction for low-energy nuclear-fusion reactions

We describe a new improved formulation of low-energy nuclear-fusion reactions based on the optical theorem. Our formulation is much less model dependent than previous theoretical approaches. We obtain an analytic formula for the cross-section,σ(E), which exhibits explicitly the energy and charge dependence ofσ(E). The formula indicates that some of the anomalous effects observed in deuterated metals may be justified theoretically if the imaginary part of the effective nuclear interaction in the elastic channel has a very weak component with a long finite interaction range.
Parameterized concept weighting in verbose queries

The majority of the current information retrieval models weight the query concepts (e.g., terms or phrases) in an unsupervised manner, based solely on the collection statistics. In this paper, we go beyond the unsupervised estimation of concept weights, and propose a parameterized concept weighting model. In our model, the weight of each query concept is determined using a parameterized combination of diverse importance features. Unlike the existing supervised ranking methods, our model learns importance weights not only for the explicit query concepts, but also for the latent concepts that are associated with the query through pseudo-relevance feedback. The experimental results on both newswire and web TREC corpora show that our model consistently and significantly outperforms a wide range of state-of-the-art retrieval models. In addition, our model significantly reduces the number of latent concepts used for query expansion compared to the non-parameterized pseudo-relevance feedback based models.
The effect of the grain boundary plane on transport properties of grain boundaries in YBa2Cu3O6+x

Abstract We have investigated the effect of the grain boundary plane on superconducting current transport in 90° [1 0 0] YBa 2 Cu 3 O x grain boundaries. In this work, samples containing a single grain boundary with a unique grain boundary plane were isolated from bulk YBa 2 Cu 3 O x samples. Transport measurements at 77 K showed that while both 90° [1 0 0] twist and symmetric tilt grain boundaries exhibit sensitivity of J c to small magnetic fields, the symmetric tilt boundaries have a considerably lower zero field J c and higher grain boundary resistivity, suggesting weaker coupling.
Endocytosis and Intracellular Distribution of PLGA Particles in Endothelial Cells: Effect of Particle Geometry

Targeting, internalization, and intracellular trafficking of carriers are key processes in drug delivery to endothelial cells. We synthesized PLGA particles with spherical and elliptical disk geometries and investigated the effect of particle shape on rate of particle endocytosis and their intracellular distribution in endothelial cells. Elliptical disks (aspect ratio of 5) were endocytosed at a slower rate compared to spheres (1.8 µm diameter) of the same volume. However, both particles were eventually internalized and accumulated around the nucleus. We quantified the orientation of elliptical disks and found that disks, on average, oriented tangentially with the nuclear membrane. The non-spherical geometry of elliptical disks brings unique aspects to the kinetics and equilibrium distribution of these particles in cells.
Modeling OPEC behavior : theories of risk aversion for oil producer decisions

Abstract Theories of OPEC such as price leadership, cartel, or game theoretic models suggest an incentive for OPEC members to expand their production capacity well above current levels in order to maximize revenues. Yet individual OPEC members consistently explore for and develop oil fields at a level well below their potential. The cause of low oil exploration and development efforts among OPEC members, and even some non-OPEC members, may have to do with risk aversion. This paper describes an alternative theory for OPEC behavior based on risk aversion using a two piece non Neumann–Morgenstern utility function similar to Fishburn and Kochenberger (1979, Decision Science 10, 503–518), and Friedman and Savage (1948, Journal of political Economy 56). The model shows possible low oil production behavior.
Leaf Blight of Endive and Escarole, Caused by Rhizoctonia solani, in California.

Endive (Cichorium endivia) and escarole (broad-leaf type of C. endivia) are two of the many leafy vegetables produced commercially in coastal California. For several years, both crops have been aff...
Sensitivity functions for multi-input linear time-invariant systems—II. Minimal-order models†

In Part I, the authors utilized frequency domain techniques to obtain low-order sensitivity models M of m-input, linear, constant, nth-order dynamic systems. The purpose of this paper is to develop a constructive approach for determining the minimal order (ρ) of M. For single-input systems it is demonstrated that ρ = n and for normal systems ρ = inn. For general systems, tight upper and lower bounds on ρ are provided. These bounds are stated in terms of the system structural properties. Procedures for synthesizing the minimal-order sensitivity models are mentioned. Examples motivate and illustrate both the key ideas and applications of the results.
CORRELATION PATTERNS IN CHARACTERISTICS OF SPATIALLY VARIABLE SEISMIC GROUND MOTIONS

A methodology for the investigation of the spatial variation of seismic ground motions is presented; data recorded at the SMART-1 dense instrument array in Lotung, Taiwan, during Events 5 and 39 are used in the analysis. The seismic motions are modeled as superpositions of sinusoidal functions, described by their amplitude, frequency, wavenumber and phase. For each event and direction (horizontal or vertical) analysed, the approach identifies a coherent, common component in the seismic motions at all recording stations, and variabilities in amplitudes and phases around the common component sinusoidal characteristics, that are particular for each recording station. It is shown that the variations in both the amplitudes and the phases of the motions at the station locations around the common component characteristics contribute significantly to the spatially variable nature of the motions, and, furthermore, they are correlated: increase in the variability of the amplitudes of the motions recorded at individual stations around the common amplitude implies increase in the variability of the phases around the common phase. The dispersion range of the amplitude and phase variability around their corresponding common components appear also to be associated with physical parameters. The spatially variable arrival time delays of the waveforms at the stations due to their upward travelling through the site topography, in addition to the wave passage delays identified from signal processing techniques, constitute another important cause for the spatial variation of the motions; their consideration in the approach facilitates also the identification of the correlation patterns in the amplitudes and phases.
Coalitions, cooperation and reproductive tactics among adult male baboons

Male savanna baboons, Papio cynocephalus, form coalitions with each other as a technique for gaining access to a female in consort with another male. Reciprocal altruism has been invoked as the primary mechanism which underlies this reproductive tactic, but a 19-month field study of the reproductive behaviour of olive baboons, P. c. anubis, in Kenya contradicted this interpretation. Males who solicited others for coalition formation were not more likely to gain access to consort females than were their fellow coalition members. Males who refused to participate in a coalition at one time were still sought as coalition partners at other times by the same male. Coalitions were generally formed by older, middle- to lower-ranking males and targeted at younger, higher-ranking males. Coalitions are a low risk reproductive tactic and the benefits are not partitioned according to initiator/joiner status. Coalitions are likely to be an outcome of cooperation between males which results from the pursuit of self-interest.
Mental health courses as a facilitator for change in a rural community.

This study documents a university effort to assist a rural community in developing a mental health educational program for primary interveners within the community. Program goals were established and evaluated on a pre- and postcourse basis and compared with a noncourse-taking group of similar professionals within the community. Results suggest some significant change in the desired direction in the course groups. The satisfaction of program participants, the request for and provision of further programs, and the substantive community changes occurring in association with the courses support the concept of community-university liaison in the development of acceptable and realistic mental health programs in rural communities.
Packaging Double-Helical DNA into Viral Capsids: Structures, Forces, and Energetics

Small, icosahedral double-stranded DNA bacteriophage pack their genomes tightly into preformed protein capsids using an ATP-driven motor. Coarse-grain molecular-mechanics models provide a detailed picture of DNA packaging in bacteriophage, revealing how conformation depends on capsid size and shape, and the presence or absence of a protein core. The forces that oppose packaging have large contributions from both electrostatic repulsions and the entropic penalty of confining the DNA into the capsid, whereas elastic deformations make only a modest contribution. The elastic deformation energy is very sensitive to the final conformation, whereas the electrostatic and entropic penalties are not, so the packaged DNA favors conformations that minimize the bending energy.
Asian American Youth in Poverty: Benefits and Limitations of Ethnic Networks in Postsecondary and Labor Force Options.

Along with the increase and demographic shift of contemporary immigrant populations, there has been a reemergence of research and debate on immigrant adaptation and assimilation theories. Under what contexts newly arriving immigrants actually adopt or resist assimilation as a means of achieving social mobility is one of the more important empirical questions raised. In the midst of this important debate, studies have consistently underscored the benefits of coethnic enclaves and networks as important means of achieving economic mobility for immigrants and their second-generation children. Despite the significance of ethnic networks, however, there is little understanding of how these networks may also be limited, and the ways in which they intersect with class, race, and school contexts to reproduce inequality. Based on a comparative study of high- and low-achieving Korean American youths in New York City public schools, this article examines under what contexts ethnic networks become beneficial and/or li...
“Don’t Let Me Be Misunderstood” Nina Simone’s Africana Womanism

This study sought to move beyond superficial appreciation of Nina Simone’s lyrics to identify and contextualize emergent constructs. A qualitative ethnographic content analysis of 44 songs was cond...
Noise characteristics of polarisation sensitive optically preamplified receivers

Using a new expression for the noise variance of optically amplified systems it is shown that the theoretical SNR degradation caused by uncontrolled polarisation at the input to optically preamplified receivers is minimal for gain sensitivities less than 4dB. This result is experimentally confirmed.
Targeting inflammatory cytokines-androgen receptor (AR) signaling with ASC-J9® to better battle prostate cancer progression

Inflammatory cytokines and chemokines released by macrophages in the prostate cancer microenvironment may signal via the androgen receptor (AR) to influence tumor progression. In particular, macrophages appear to promote tumorigenesis by altering the chemokine (C-C motif) ligand 4 (CCL4)/AR signaling axis. This process can be blocked by ASC-J9®, an enhancer of AR degradation. ASC-J9® also inhibits the CCL2-dependent, signal transducer and activator of transcription 3 (STAT3)-mediated pro-metastatic signaling cascade that is generally activated by androgen deprivation therapy. Thus, targeting inflammatory cytokines signaling via the AR, with ASC-J9®, represents a promising therapeutic approach against prostate cancer progression.
The Effect of Action Valence and Race on 3- to 8-Year-Old Children's Social Cognitive Judgments

The present study investigated children's judgments of actions as a function of the valence of the action and the race of the actor. Three- to 8-year-old children were read an illustrated storybook in which 1 character did not share (a negatively valenced action) and the other character was helpful (a positively valenced action). The race of the characters was manipulated such that in the story, there was 1 Black character and 1 White character. Children were asked to make judgments about how mean/nice the characters were and what consequence (reward or punishment) they should receive for their actions. Despite the fact that children of this age show explicit and implicit pro-White biases (e.g., Baron & Banaji, 2006), children's judgments were based solely on the valence of action and not on character race. The findings are discussed in light of moral development and the development of bias as it pertains to race.
Determination of oxygen in lithium by the vacuum distillation method

Vacuum distillation determination of O in Li, evaluating accuracy through O additions and recoveries, method blank and residue identification
Enhanced antenatal detection of group B streptococcus colonization.

Objective: To improve culture methods for the detection of group B streptococcus colonization. Methods: This study prospectively compared the standard culture medium, a blood agar plate, to a selective culture medium, Todd Hewitt broth with antibiotics, and compared vaginal culture with rectal culture at the first prenatal exam. Results: Of the 383 vaginal swabs received for evaluation of the two culture media, 78 (20.4%) were positive for group B streptococcus. The detection rates of the blood agar plate method and the Todd Hewitt broth with antibiotics were 64.1 and 97.4%, respectively. Using the Todd Hewitt broth with antibiotics, an additional 94 patients were cultured vaginaHy and rectally. Twenty-nine (30.9%) had positive cultures. The rate of detection was 58.6% for the vaginal culture, 89.7% for the rectal culture, and 100% for both culture sites combined. Conclusion: These data indicate that culture detection of group B streptococcus can be improved by using both a selective broth medium and a dual vaginal and rectal culture.
On the psychophysical discriminability of somatosensory nerve action potential patterns with irregular intervals

In this paper we consider the problem of whether or not a series of irregularities in the interpulse intervals in a train of nerve action potentials can be discriminated better than a single gap in a regular train. We also consider the corollary problem-does an increase in the number of impulses in a burst with irregular intervals lead to a decrease in the threshold for irregularity, thus indicating some integrative capacity of the relevant neural decoding mechanism. Answers to these questions are obtained by means of a psychophysical test and are affirmative in both cases. This suggests that the irregularities which have been observed in the intervals between nerve action potentials in animal preparations are true information-carrying codes within a restricted temporal region. Because of certain critical points in the functions relating this sensitivity to the basic frequency of the nerve impulses, a group of seiveral temporal regions is postulated in which time is dealt with differently by the somatosensory system.
Hypothalamic serotonin in the control of meal patterns and macronutrient selection.

Abstract Serotonin (5-HT) is believed to have an inhibitory influence over feeding behavior. The present experiments were designed to investigate the effects of hypothalamic 5-HT on spontaneously motivated feeding and appetite regulation. Freely-feeding rats were injected with 5-HT or norfenfluramine (NORFENF) directly into the paraventricular hypothalamus (PVN), and precise changes in feeding behavior were monitored by a computer. Following PVN 5-HT or NORFENF injection, animals exhibited a marked suppression in food intake, associated with a decrease in meal size, duration and eating rate and no change in the frequency of meals consumed. This suggests that brain 5-HT may influence primarily the induction of satiety rather than the suppression of hunger. The effect of drugs presumed to affect brain 5-HT transmission on diet selection was also investigated in groups of rats injected centrally with 5-HT or NORFENF or peripherally with either fenfluramine, quipazine or cyproheptadine. In a series of 2-diet tests, rats centrally injected with 5-HT or NORFENF exhibited a selective suppression of the carbohydrate-rich diets. In animals provided with three pure macronutrient diets, protein, carbohydrate and fat, systemic administration of serotonergic agents had its greatest impact on fat and carbohydrate ingestion, as compared to protein consumption. These findings support a role for hypothalamic 5-HT in modulating meal patterns and appetite for particular macronutrients.
Electron--phonon scattering in potassium at high magnetic fields

We have measured the temperature dependence of both the zero-field resistivity and the transverse magnetoresistance of polycrystalline potassium wires (ϱ(300 K)/ϱ(4.2 K)=140 to 6000) in fieldsH≲35 kG and at temperaturesT≲4.2 K. Our principal findings are: 1) The presence of a large magnetic fieldH=35 kG does not alter the temperature dependence of ϱ from that observed atH=0; below 4.2 K theT-dependent part of the resistivities,ϱT(H=0) andϱT(H=35 kG), fit well to the function exp (−Θ*/T) with the same Θ*=23K. 2) Deviations from Matthiessen's rule are significantly reduced in a strong field so that the magnitude ofϱT(H=0) approaches that ofϱT(H=35 kG) as sample purity decreases. 3) The slope of the high-field linear magnetoresistance increases slightly (≲8%) from 1.5 K to 4.2 K. We attribute the exponential temperature dependence ofϱT(H) to the freezing out of electron-phonon umklapp processes as has been shown for the zero-field resistivity. The reduction in deviations from Matthiessen's rule at high fields can be understood within semiclassical theory, but the latter cannot explain the failure ofϱT(H) to saturate at high fields. A proposal by Young that electron-phonon umklapp scattering may contribute aT-dependent high-field linear magnetoresistance in potassium is considered.
The effect of magnesium on matrix metalloproteinase-9 activity in umbilical cord blood at delivery of pregnancies complicated by chorioamnionitis

ACTIVITY IN UMBILICAL CORD BLOOD AT DELIVERY OF PREGNANCIES COMPLICATED BY CHORIOAMNIONITIS PETER NAPOLITANO, PATRICK MCNUTT, JAMES WRIGTH, BOBBY HOWARD, ANDREA FISK, PETER NIELSEN, NATHAN HOELDTKE, Madigan Army Medical Center, Obstetrics and Gynecology, Division Maternal-Fetal Medicine, Tacoma, WA Madigan Army Medical Center, Clinical Investigations, Tacoma, WA Madigan Army Medical Center, Obstetrics & Gynecology, Division Maternal-Fetal Medicine, Tacoma, WA Tripler Army Medical Center, OBGYN, Division MFM, Honolulu, HI OBJECTIVE: Matrix metalloproteinase-9 (MMP-9) is an inflammatory cytokine that is increased in preterm intrauterine infection and may be associated with the development of cerebral palsy. Our objective was to determine umbilical cord serum concentrations of MMP-9 in term pregnancies complicated by chorioamnionitis compared to controls, and to determine if magnesium alters MMP-9 enzymatic activity. STUDY DESIGN: Umbilical cord serum was obtained from 6 term pregnancies with chorioamnionitis and 5 term pregnancies without chorioamnionitis. Samples were analyzed using MMP-9 activity assay (Amersham Biosciences) for total enzyme and percent active enzyme. The MMP-9 was then exposed to magnesium (Mg), at concentrations of 6.0 mg/dl and 60.0 mg/dl, and the enzyme activity was re-evaluated. All results are reported as the mean ± SEM. RESULTS: There was no difference in cord serum concentrations of MMP-9 between pregnancies with chorioamnionitis and normal controls (40.8 ± 9.9 ng/ml versus 28.0 ± 1.5 ng/ml, p = 0.26). There was no difference in endogenous MMP-9 enzyme activity between groups (p = 0.78). There was a 40% drop in total measured MMP-9 enzyme activity (p < 0.0001) at a Mg concentration of 6.0 mg/dl and a 97% drop (p < 0.0001) at a Mg concentration of 60.0 mg/dl. CONCLUSION: In term pregnancies the presence of clinical chorioamnionitis does not appear to affect the level of MMP-9 found in umbilical cord blood. However, there is a significant decrease in total measured MMP-9 enzyme activity upon in vitro exposure to Mg at a concentration therapeutically achieved in obstetrics. This decreased activity may be due to Mg competitively inhibiting zinc dependent MMP-9 activity, and this may be one mechanism to explain the association of in utero Mg exposure with a decreased incidence of cerebral palsy in preterm delivery.