cssi/SciSciGPT-SciSciNet huggingface dataset:
Investigating flow properties of partially cemented fractures in Travis Peak Formation using image‐based pore‐scale modeling

Natural fractures can provide preferred flow pathways in otherwise low-permeability reservoirs. In deep subsurface reservoirs including tight oil and gas reservoirs, as well as in hydrothermal systems, fractures are frequently lined or completely filled with mineral cement that reduces or occludes fracture porosity and permeability. Fracture cement linings potentially reduce flow connectivity between the fracture and host rock and increase fracture wall roughness, which constricts flow. We combined image-based fracture space characterization, mercury injection capillary pressure and permeability experiments, and numerical simulations to evaluate the influence of fracture-lining cement on single-phase and multiphase flows along a natural fracture from the Travis Peak Formation, a tight gas reservoir sandstone in East Texas. Using X-ray computed microtomographic image analysis, we characterized fracture geometry and the connectivity and geometric tortuosity of the fracture pore space. Combining level set method-based progressive quasistatic and lattice Boltzmann simulations, we assessed the capillary-dominated displacement properties and the (relative) permeability of a cement-lined fracture. Published empirical correlations between aperture and permeability for barren fractures provide permeability estimates that vary among each other, and differ from our results, vary by several orders of magnitude. Compared to barren fractures, cement increases the geometric tortuosity, aperture variation of the pore space, and capillary pressure while reducing the single-phase permeability by up to 2 orders of magnitude. For multiphase displacement, relative permeability and fluid entrapment geometry resemble those of porous media and differ from those characteristic of barren fractures.
Structural and property studies of high Zr-content lead zirconate titanate

Abstract Lead zirconate titanate (PZT) ceramics with Zr Ti ratios between 95 5 and 55 45 have been examined by transmission electron microscopy (TEM), dielectric spectroscopy, and Sawyer-Tower polarization measurements. It is believed that in the high Zr-content end of PZT phase diagram, that the relative phase stability is directly related to a coupling of the polarization to various oxygen octahedral rotational systems. The transformation between the high and low temperature rhombohedral ferroelectric phases (FER(HT)-FER(LT)) in PZT 90/10 was found to be associated with a transition between a high temperature M-type and a low temperature R-type oxygen rotational system. However, with increasing Ti-content ( Zr Ti 80 20 ) a transition between a disordered R-type tilted state to a low temperature ordered R-type tilted state was found near the FER(HT)-FER(LT) boundary. The transition between the disordered and ordered R-type tilted states became increasingly gradual with increased Ti-content. In the FER(LT) state, local strains due to random octahedral rotations are believed to disrupt the long-range polar order, resulting in metastability effects characterized by dielectric relaxation.
Diamond powders as neutron filters

Low-energy band-pass filters are essential components for many neutron-scattering measurements, particularly cold-neutron inelastic scattering. There has been widespread use of polycrystalline Be filters for typical cutoff energies near 5 meV. The need to cool the filters to minimize thermal diffuse scattering is inconvenient for many experiments and for this reason we have investigated alternatives. Polycrystalline diamond appears to be an excellent candidate, with the large Debye temperature reducing the need for cooling, an abundant supply of inexpensive material, and a large scattering length density. Using the ORELA pulsed neutron source and the HFIR at ORNL, we have characterized the energy dependence of the room temperature neutron transmission for several commercially available powders of both natural and artificial diamond with homogeneous particle sizes ranging from single digits to hundreds of microns. Sharp cutoffs are observed near neutron energies of 5 meV. The low-energy transmission is reduced by small-angle scattering from voids, and we have begun to investigate methods of overcoming this limitation. Nevertheless, for some applications room temperature diamond powders are viable neutron filters.
Nonequilibrium Solvation Effects for a Polyatomic Reaction in Solution

We present a general linear-response method for including nonequilibrium solvation effects (solvent friction effects) in variational transition state theory with multidimensional tunneling (VTST/MT) for calculating reaction rate constants in solution. The generalized Langevin approach is used to include a collective solvent coordinate into VTST/MT, and a general prescription is suggested for coupling this collective solvent coordinate to the solute, which is treated in its full dimensionality. The new formalism is illustrated by application to the aqueous free radical reaction H + CH3OH → H2 + CH2OH at 298 K. This reaction is treated with a linear mixing of Hartree−Fock theory and Austin Model 1 with specific reaction parameters (HF||AM1-SRP). The results with nonequilibrium solvation (NES) are compared to those obtained earlier with the separable equilibrium solvation (SES) and the equilibrium solvation path (ESP) approximations. We focus on the speedup due to solvation and on the kinetic isotope effects...
Systemic acquired resistance in moss: further evidence for conserved defense mechanisms in plants.

Vascular plants possess multiple mechanisms for defending themselves against pathogens. One well-characterized defense mechanism is systemic acquired resistance (SAR). In SAR, a plant detects the presence of a pathogen and transmits a signal throughout the plant, inducing changes in the expression of various pathogenesis-related (PR) genes. Once SAR is established, the plant is capable of mounting rapid responses to subsequent pathogen attacks. SAR has been characterized in numerous angiosperm and gymnosperm species; however, despite several pieces of evidence suggesting SAR may also exist in non-vascular plants6–8, its presence in non-vascular plants has not been conclusively demonstrated, in part due to the lack of an appropriate culture system. Here, we describe and use a novel culture system to demonstrate that the moss species Amblystegium serpens does initiate a SAR-like reaction upon inoculation with Pythium irregulare, a common soil-borne oomycete. Infection of A. serpens gametophores by P. irregulare is characterized by localized cytoplasmic shrinkage within 34 h and chlorosis and necrosis within 7 d of inoculation. Within 24 h of a primary inoculation (induction), moss gametophores grown in culture became highly resistant to infection following subsequent inoculation (challenge) by the same pathogen. This increased resistance was a response to the pathogen itself and not to physical wounding. Treatment with β-1,3 glucan, a structural component of oomycete cell walls, was equally effective at triggering SAR. Our results demonstrate, for the first time, that this important defense mechanism exists in a non-vascular plant, and, together with previous studies, suggest that SAR arose prior to the divergence of vascular and non-vascular plants. In addition, this novel moss – pathogen culture system will be valuable for future characterization of the mechanism of SAR in moss, which is necessary for a better understanding of the evolutionary history of SAR in plants.
Nonresponse error in injury-risk surveys.

Background Nonresponse is a potentially serious source of error in epidemiologic surveys concerned with injury control and risk. This study presents the findings of a records-matching approach to investigating the degree to which survey nonresponse may bias indicators of violence-related and unintentional injuries in a random-digit-dialed (RDD) telephone survey. Methods Data from a statewide RDD survey of 4155 individuals aged 16 years and older conducted in Illinois in 2003 were merged with ZIP code–level data from the 2000 Census. Using hierarchical linear models, ZIP code–level indicators were used to predict survey response propensity at the individual level. Additional models used the same ZIP code measures to predict a set of injury-risk indicators. Results Several ZIP code measures were found to be predictive of both response propensity and the likelihood of reporting partner violence. For example, people residing in high-income areas were less likely to participate in the survey and less likely to report forced sex by partner, processes that suggest an over-estimation of this form of violence. In contrast, estimates of partner isolation may be under-estimated, as those residing in geographic areas with smaller-sized housing were less likely to participate in the survey but more likely to report partner isolation. No ZIP code–level correlates of survey response propensity, however, were found also to be associated with driving-under-the-influence (DUI) indicators. Conclusions There is evidence of a linkage between survey response propensity and one variety of injury prevention measure (partner violence) but not another (DUI). The approach described in this paper provides an effective and inexpensive tool for evaluating nonresponse error in surveys of injury prevention and other health-related conditions.
Calculation of solar pond thermal efficiency with a diffusely reflecting bottom

Abstract A calculational procedure is given to determine the thermal efficiency of a solar pond with a diffusely reflecting bottom. The results are presented in terms of four universal curves and includes the effect of rereflected light from the pond surface. The procedure is compared with previous calculational methods that assume a specularly reflecting bottom or no rereflection term. Results of the calculational method indicate that decreasing the bottom reflectivity from R = 0.20, typical of dirt, to R = 0.05 significantly increases pond thermal efficiency.
Design of novel σ*-π* conjugated polysilanes

Abstract Electronic structures of two novel σ * -π * conjugated polysilanes, poly(1,1-silole) and poly(1,1-benzo[ c ] silole), have been studied theoretically using the one-dimensional tight-binding self-consistent field-crystal orbital (SCF-CO) method at the modified neglect of diatomic overlap, Austin Model 1 (MNDO-AM1) level of approximation. It is found that the bandgaps corresponding to the σ-σ * transition of the polymers are smaller than that of the conventional polysilanes. The σ-σ * bandgaps of these two polymers are essentially determined by the lower-lying conduction band derived from the mixing of the delocalized σ * -band of the silicon skeleton and the localized π * -band of the side chains. Results suggest that the σ * -π * conjugation may be more effective for the reduction of the bandgap than the σ-π conjugation in a polysilane with aryl side chains.
Magnetic Rotation Spectrum and Heat of Dissociation of the Potassium Molecule

The magnetic rotation spectrum of the near red, $^{1}\ensuremath{\Pi}\ensuremath{-}^{1}\ensuremath{\Sigma}$ band system of ${\mathrm{K}}_{2}$ has been photographed with the apparatus previously used for ${\mathrm{Li}}_{2}$. In this way the series of upper vibrational levels has been extended from the 16th, the last one observed by Crane and Christy, to the 27th. This permits an accurate extrapolation to convergence, which is estimated to occur at ${v}^{\ensuremath{'}}=31.6$, the corresponding energy being 17160 ${\mathrm{cm}}^{\ensuremath{-}1}$ = 2.12 volts. It follows that the heat of dissociation of the normal molecule is 0.51\ifmmode\pm\else\textpm\fi{}0.02 volt. From this and other data the percentage of molecules in the vapor at various temperatures is calculated. An improved Franck-Condon diagram for the red and infrared systems of ${\mathrm{K}}_{2}$ has been constructed. It gives a good representation of the observed distribution of bands and predicts the existence of an infrared edge. This is confirmed by observation. Magnetic rotation spectra have been found in the regions of the infrared and blue $^{1}\ensuremath{\Sigma}\ensuremath{-}^{1}\ensuremath{\Sigma}$ systems. They are probably analogous to the red magnetic rotation spectrum of sodium, and like it, are not yet understood.
On meridional transports of heat and freshwater in the pacific ocean. Über den Wärme- und Süßwassertransport im Pazifischen Ozean

For the Pacific Ocean estimates of meridional heat and freshwater transport are available from three independent approaches, namely (a) evaluation of the surface budget and subsequent integration with latitude; (b) direct evaluation from zonal hydrographic sections, and (c) estimate of the divergence of zonal property transport in the Antarctic Circumpolar Current from meridional hydrographic sections. The latter two methods (b) and (c) do not account for interannual variability and annual cycle and are thus not directly comparable to method (a) which refers to multi-annual mean conditions. Concerning the Pacific heat transport, a southward directed flux across 30 °N computed from a zonal hydrographic section (method b) is inconsistent with the surface energy budget. Zonal hydrographic sections at 28 and 43 °S (method b), as well as method (c) for 40 °S yield much smaller poleward heat transports than evaluation from the surface heat budget (a).
Alkali Earth Metal Binding Properties of Ionic Microgels

Spherical micron-sized (4−10 μm in diameter) poly(methacrylic acid-co-acrylic acid) microgels were synthesized by precipitation polymerization, and their chelation reactions with chloride salts of Mg2+, Ca2+, Sr2+, and Ba2+ were investigated by isothermal titration calorimetry (ITC). Ion concentrations obtained by inductively coupled-plasma mass spectrometry (ICP-MS) were used to obtain binding constants and to verify the results obtained by ITC. Although the two methods agreed within 20%, the ITC measurements were experimentally easier to obtain and more accurate. Interference contrast microscopy and micropipet manipulation techniques were used to measure the volume change and corresponding dehydration of the microgels as a function of divalent ion type and concentration. The ITC results showed that the addition of MCl2 electrolytes, where M represents a divalent metal, with the microgels was an entropy driven reaction in that ΔG ∼ −20 kJ/mol ≅ TΔS. These data suggest that the free energy driving the ion...
Identification of structural dynamics systems using least-square lattice filters

A new approach for identifying the dynamics of large space structures with noisy measurements is presented. In this approach the system's order is recursively determined on-line, along with mode shapes using recursive lattice filters that are widely used in adaptive signal processing. Order determination results are presented using both statistical hypothesis testing and threshold testing. The approach is illustrated for the problem of identifying the structural dynamic characteristics of a free-free beam. Simulation results are presented on the effectiveness and accuracy of the identification scheme for various noise levels, sampling rates, and data window sizes. Experimental results are presented for order and mode shape estimation. The mode shape estimation is compared with that obtained by an alternate nonlinear least-square algorithm.
Volumetric Mixing in Anionic/Nonionic, Cationic/Nonionic, and Anionic/Cationic Mixed Micelles

Abstract The volumetric mixing in anionic/nonionic, cationic/nonionic, and anionic/cationic mixed micelles was determined by examining the total surfactant apparent molar volumes (φ V,tot ) at total surfactant concentrations ( C T ) much greater than the mixture critical micelle concentration (CMC m ). The mixed surfactant systems investigated were sodium dodecyl sulfate and a polyethoxylated nonylphenol, at 0.15 M NaCl and with no added NaCl; cetyl pyridinium chloride and polyethoxylated nonylphenol, at 0.03 M NaCl; and sodium dodecyl sulfate and dodecyl pyridinium chloride, at 0.15 M NaCl. For all of the mixed surfactant systems investigated, the volumetric mixing in the mixed micelles at C T >> CMC m was ideal, even though the free energies of mixing at the onset of mixed micelle formation (as indicated by the mixture critical micelle concentrations at C T = CMC m ) exhibited strong negative deviations from ideality. Furthermore, added electrolyte was shown to have virtually no effect on the φ V,tot data (nor, consequently, the volumetric mixing) for the anionic/nonionic mixed surfactant system. The results of this study suggest that at C T >> CMC m , the electrostatic interactions do not significantly affect the molar volume of the mixed micelle. Therefore, the micelle hydrophobic core dominates the volumetric mixing in mixed micelles at C T >> CMC m .
Role for Fe(III) minerals in nitrate-dependent microbial U(IV) oxidation.

Microbiological reduction of soluble U(VI) to insoluble U(IV) is a means of preventing the migration of that element in groundwater, but the presence of nitrate in U(IV)-containing sediments leads to U(IV) oxidation and remobilizaton. Nitrite or iron(III) oxyhydroxides may oxidize U(IV) under nitrate-reducing conditions, and we determined the rate and extent of U(IV) oxidation by these compounds. Fe(III) oxidized U(IV) at a greater rate than nitrite (130 and 10 μM U(IV)/day, respectively). In aquifer sediments, Fe(III) may be produced during microbial nitrate reduction by oxidation of Fe(II) with nitrite, or by enzymatic Fe(II) oxidation coupled to nitrate reduction. To determine which of these mechanisms was dominant, we isolated a nitrate-dependent acetate- and Fe(II)-oxidizing bacterium from a U(VI)- and nitrate-contaminated aquifer. This organism oxidized U(IV) at a greater rate and to a greater extent under acetate-oxidizing (where nitrite accumulated to 50 mM) than under Fe(II)-oxidizing conditions....
Squeezable bases: local orthogonal bases on nonuniform grids

We describe a method for adapting local shift-invariant bases to non-uniform grids via what we call a squeeze map. When the shift-invariant basis is orthogonal there is a squeeze map such that the nonuniform basis is orthogonal and has the same smoothness and same approximation order as the shift-invariant basis. When the smoothness or approximation order is large enough the squeeze map is uniquely determined and may be calculated locally in terms of the ratios of adjacent intervals. Therefore a basis may be rapidly generated for a given grid. Furthermore local changes in a grid (for example knot insertion or deletion) only affect a few of the basis functions. When starting with a refinable scaling vector the squeeze map machinery gives a procedure for generating orthogonal wavelets on semi-regular grids (that is, an arbitrary non-uniform coarse space with uniform refinements) with the same polynomial reproduction and smoothness as the shift-invariant space.
Recursive Implementation of a Two-Step Nonparametric Decision Rule

The two-step approach to nonparametric discrimination is that of estimating class-conditional densities and deriving the Bayes decision rule as if the estimates were true. Direct implementation of such a decision rule ecounters two computational problems. Complexity increases with sample size, and finite precision limits the decision rule domain. Here a recursive algorithm to reduce the expected number of operations and word-length limitations below that of the direct approach is developed. A special case of the formulation reduces to the weighted k-nearest-neighbor rule.
Genome mining of a prenylated and immunosuppressive polyketide from pathogenic fungi

Activation of the polycyclic polyketide prenyltransferase (pcPTase)-containing silent clusters in Aspergillus fumigatus and Neosartorya fischeri led to isolation of a new metabolite neosartoricin (3). The structure of 3 was solved by X-ray crystallography and NMR to be a prenylated anthracenone. 3 exhibits T-cell antiproliferative activity with an IC50 of 3 μM, suggestive of a physiological role as an immunosuppressive agent.
Development of a multi-tiered recycling strategy with a sodium-cooled Heterogeneous Innovative Burner Reactor

Abstract The Sodium-Cooled Heterogeneous Innovative Burner Reactor (SCHIBR) model created at the University of South Carolina uses heterogeneous minor actinide targets. To improve minor actinide transmutation, a hybrid fuel management scheme is utilized involving initially moderated assemblies on the core periphery followed by a second period of irradiation in a fast flux with the moderating rods removed. A multi-tiered recycling strategy was developed to increase plutonium utilization in the SCHIBR model through the recycle of the driver fuel. An equilibrium fuel cycle was evaluated with the computer code ERANOS to determine the improvements in fuel utilization, reduction in high level waste, and safety of the SCHIBR design. Fuel depletion studies were conducted to determine the composition of input and output streams in order to develop reactor recipes for use in the fuel cycle simulation code, VISION. The once-through SCHIBR model reduces the radiotoxicity of high level waste by 66% of the once-through LWR model after 300 years in storage. The multi-tiered recycling strategy offers improvements over the previous once-through SCHIBR model by reducing the radiotoxicity by 86% after 300 years in storage.
Comparison of low-energy collisionally induced dissociation of n-butyl benzene ions with photodissociation

Abstract The collisionally induced dissociation of n-butyl benzene ions to form C7H7+ or C7H8+ fragments has been examined at centre-of-mass collision energies in the range 0–30 eV using a triple quadrupole. The target gases were methane, nitrogen, argon, propane and krypton. The ratio of the intensities of the fragment ions has previously been shown by photodissociation experiments to be a very sensitive function of the internal excitation energy of the parent ion. For all the target gases, the ratio of C7H7+ to C7H8+ rose almost linearly with centre-of-mass collision energy above the threshold for C7H7+ formation, but the ratio reached a maximum at an energy of ∼ 9 eV and slowly declined at higher energies. The maximum ratio was target-dependent and a comparison with the photodissociation data suggests that slightly lower amounts of excitation energy are available when the target is polyatomic. The equivalent internal excitation energies are much higher than those found in high-energy collisional activation, indicating the efficiency of the direct translational to vibrational energy conversion that occurs at low collision energies. Measurements of fragmention energy distributions show distinct differences between C7H7+ and C7H8+
Socializing Identities through Speech Style: Learners of Japanese as a Foreign Language by COOK, HARUKO MINEGISHI

The article reviews the book "Socializing Identities Through Speech Style: Learners of Japanese as a Foreign Language," by Haruko Minegishi Cook.
Perceived Stress in Multiple Sclerosis The Potential Role of Mindfulness in Health and Well-Being

Stressful life events are associated with worsening neurological symptoms and decreased quality of life in multiple sclerosis (MS). Mindful consciousness can alter the impact of stressful events and has potential to improve health outcomes in MS. This study evaluated the relationship between trait mindfulness and perceived stress, coping, and resilience in people with MS. Quality of life was assessed as a secondary outcome. One hundred nineteen people with confirmed MS completed the Five-Facet Mindfulness Questionnaire, Perceived Stress Scale, Brief Coping Orientation for Problem Experiences, Connor-Davidson Resilience Scale, and Medical Outcome Study Short Form–36. Greater trait mindfulness was significantly associated with decreased psychological stress, better coping skills, increased resilience, and higher quality of life. After investigators controlled for confounders, mindfulness accounted for 25% of the variation in perceived stress scores and 44% of the variation in resilience scores. Results supp...
SIMULATION OF SPUTTERING INDUCED BY HIGH ENERGY GOLD CLUSTERS

Recently Andersen et al. reported exceptionally large nonlinear sputtering yields following the bombardment of gold targets with small, high energy gold clusters (H.H. Andersen, A. Brunelle, S. Della-Negra, J. Depauw, Y. LeBeyec, Phys. Rev. Lett. 80 (1998) 5433). Nonlinearities up to ∼1000% were observed for Au_5 clusters with a total energy of 800 keV. We have carried out molecular dynamics simulations on a massively parallel computer to model the Au_n → Au system. The results suggest that both collisional and thermal spike mechanisms contribute to the large nonlinear yields observed by Andersen et al. Our simulations also indicate that sputtering statistics are very important at high cluster bombarding energies. A substantial fraction of the simulated impacts produce no sputtered atoms, while individual sputtering events producing very large numbers of sputtered atoms contribute significantly to the total sputtering yield at high energy.
Polarized scattered light as a probe for structure and change in bioparticles

Polarized light scattered from small particles -- spheres, fibers, dust, defects and biomaterial -- carries information about the optical and geometrical properties and even more esoteric properties of the scatterer. This highly developed, powerful, but under used technique is sensitive enough to detect a 0.5 nanometer radius change in a 1.0 micron diameter quartz fiber. The complete set of 16 polarized light scattering signals from any scatterer form a 16- element Mueller matrix, Sij, which is the signature of the scatterer's status quo. Changes in cell morphology, internal arrangement and metabolic activity cause changes in radius, refractive index and absorption and therefore changes in the polarization signals Sij which act as the probe. We demonstrate how the Sij can type human red blood cells, do bacteria autopsies, distinguish between different types of white blood cells, bacteria, spores, and study cell life cycle and degradation as biomaterial undergoes biologically significant change.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Ammonia utilization by the bruchid beetle, Caryedes brasiliensis [Bruchidae]

The seed predator,Caryedes brasiliensis [Bruchidae] generates appreciable ammonia in its dietary use and detoxification ofl-canavanine and its catabolic product,l-canaline.l-Canavanine is a toxic allelochemical ofDioclea megacarpa seeds, the food of the developing larvae. Bruchid beetle larvae rely upon glutamic acid dehydrogenase and glutamine synthetase to use ammonia for glutamic acid synthesis from 2-oxoglutaric acid and conversion of the former to glutamine. These reactions provide the larvae with a means for metabolically eliminating ammonia. Proline serves as a carbon skeleton source for glutamic acid formation.
Central Hypertensive Effects of Aldosterone

The soluble mineralocorticoid receptor bound to an agonist acts as a transcription factor for several genes relevant to ion transport by kidney and colon epithelial cells and is a major regulator of electrolyte and fluid homeostasis. Mineralocorticoids, the most prominent of which is aldosterone, also influence the activity of nonepithelial target cells, including vascular smooth muscle cells, by altering intracellular ion transport and content. Evidence is summarized for mineralocorticoid modulation of neuronal activity in a center or centers within the brain, probably in the periventricular area of the anterior hypothalamus, where information on electrolyte, fluid, and cardiovascular status is received and integrated, resulting in alterations in central sympathetic efferent activity. These functions are distinct from central aldosterone effects on salt appetite and peripheral trophic effects on cardiovascular tissue. The isolated mineralocorticoid receptor binds several adrenal steroids, including aldosterone and the major glucocorticoids, with equal affinity. Ligand specificity for the mineralocorticoid receptor differs between tissues, including different organs in the brain. Specificity is conferred extrinsically by the 11-β-hydroxysteroid dehydrogenase enzymes in transport epithelia, but mechanisms for mineralocorticoid ligand specificity have not been completely defined in the brain. The functional interaction between the mineralocorticoid receptor bound to different ligands and between the mineralocorticoid and glucocorticoid receptors is complex and as yet unresolved. Evidence is presented for thede novosynthesis of adrenal corticosteroids in the brain which may, by paracrine regulation of central control mechanisms, be relevant for certain clinical and experimental forms of hypertension characterized by low circulating levels of mineralocorticoids which respond to mineralocorticoid receptor antagonists.
Long QT Mutations and KCNE1 β-Subunit Modulate S4 Movement in KCNQ1 Channel

The KCNQ1 potassium channel is expressed in many different cell types and plays widely different physiological roles. For example, in the heart KCNQ1 forms part of the voltage-gated IKs channels that contributes to limiting the duration of the cardiac action potential. The different functions of the KCNQ1 channel are mainly due to the co-assembly of the KCNQ1 channel with different beta subunits from the KCNE family. The IKS channel consists of 4 α-subunits (KCNQ1) which assemble with 2 to 4 β subunits (KCNE1). Mutations in either KCNQ1 or KCNE1 subunit cause multiple cardiac arrhythmia syndromes such as long QT syndrome, short QT syndrome, and familial atrial fibrillation. Here we use Voltage clamp fluorometry (VCF) to directly study the effects of wild type, mutant KCNQ1 and KCNE1 subunits on the voltage sensor movement in KCNQ1 channel. We assess the voltage sensor movement (fluorescence) and channel opening (current), in order to understand the coupling between the KCNQ1 voltage sensor and channel gate in the presence of KCNE1. Our data show that KCNE1 splits the voltage sensor movement in two separates phases. An early phase (1) involving voltage sensor movements to its active state upon changes in the membrane potential occurs at hyperpolarized potentials. A second phase (2) that happens at much more depolarized potentials involves an additional voltage sensor movement which is tightly coupled to channel opening. Mutations in KCNE1 that cause arrhythmia shift the voltage dependence of the voltage sensor movements of either phases 1 or 2 (or both), revealing some of the molecular mechanisms underlying the pathophysiology of these arrhythmia-causing mutations. Our data suggests a putative mechanism for how KCNE1 exerts its effects on the voltage sensor movement during IKs channel activation.
A Survey of Economic Understanding in U.S. High Schools

The recent widespread adoption of online competitions in economic education provides a unique opportunity to make frequent assessments of economic literacy in U.S. classrooms. In this survey, student responses to test items from the Test of Economic Literacy (TEL) are used to create economic concept and content area achievement benchmarks. These benchmarks provide an interim renorming of the TEL and allow the authors to gauge the status of economic understanding among high school students. The data also allow the authors to compare learning outcomes between regular and advanced economics classes. Finally, the authors find that students in advanced economics classes significantly outperform students in regular classes.
Upregulation of Endothelial and Inducible Nitric Oxide Synthase Expression by Reactive Oxygen Species

BACKGROUND: The effect of reactive oxygen species (ROS) on nitric oxide synthase (NOS) expression remains uncertain. This study explored the effect of increased ROS activity on NOS expression in vitro in human coronary artery endothelial cells (HCAECs) grown in culture and in intact animals. METHODS: Endothelial NOS (eNOS) expression and nuclear factor kappaB (NFkappaB) activation were determined in HCAECs grown in culture and exposed to oxidative stress with xanthine-xanthine oxidase (X-XO) generated superoxide, H(2)O(2), or glutathione depletion with buthionine sulfoximine (BSO) for 24 h. In parallel experiments, cells were treated with a nitric oxide (NO) scavenger (hemoglobin), and with an NO donor S-nitroso-N-acetyl penicillamine (SNAP)]. In addition, eNOS and inducible NOS (iNOS) expressions were determined in rats treated with either BSO or vehicle for 48 h. RESULTS: Increases in ROS activity, achieved by exogenous superoxide and H(2)O(2) or by glutathione depletion, upregulated the expression of eNOS at both transcriptional and translational levels in HCAECs. Similar effects were seen with the non-radical NO scavenger, hemoglobin. The upregulatory action of hemoglobin on eNOS messenger RNA (mRNA) and protein expressions was overcome by the NO donor, SNAP, thereby suggesting that there is a negative feedback regulation of eNOS by NO. Nuclear translocation of NFkappaB (p65) was noted within 5 min of exposure to H(2)O(2) and at least 15 min after exposure to superoxide or BSO. Induction of oxidative stress by glutathione depletion led to upregulation of renal and aorta eNOS and iNOS in live animals. CONCLUSIONS: An increase in ROS activity upregulates NOS expression in vitro in HCAECs grown in culture, and also in vivo in animals. This effect appears to be, in part, mediated by limiting the availability of NO, thereby exerting a negative feedback influence on NOS expression through activation of NFkappaB.
Long-term local effects of intraosseous infusion on tibial bone marrow in the weanling pig model

Abstract The weanling pig model was used to determine the long-term local effects, if any, on tibial bone marrow after intraosseous (IO) infusion of resuscitation fluid and drugs at standard dosages. One of six IO treatments (two normal saline boluses [20 mL/kg]; bolus sodium bicarbonate [1 mEq/kg]; 10% sodium bicarbonate infusion at a maintenance rate for 1 hour; bolus 1:10,000 epinephrine [0.01 mg/kg]; 1:10,000 epinephrine solution infusion, 1 μg/kg/min for 1 hour; or dopamine infusion, 10 μg/kg/min for 1 hour) was randomly administered via the left tibia to 18 pigs at 4 weeks of age. The animals were subsequently followed for 3 months, after which marrow from the same space and peripheral blood were examined. Marrow from the right tibia of each animal served as control; untreated historic controls were also used for comparison. Examination of the marrow revealed normal cell differentials in all limbs in all groups. Overall cellularity was somewhat decreased in the experimental limbs of the normal saline bolus group when compared with same-animal control limbs, perhaps due to the pressure effect from rapid injection. Peripheral blood counts and differentials in these and all other animals were normal. The authors conclude that IO administration of commonly used resuscitative medications does not result in significant adverse effects in the tibial bone marrow in this model.
Thoracic Impedance Gradient with Respect to Breathing

The transthoracic mutual-impedance responses to lung ventilation were measured for 37 normal subjects with 14 orthogonal lead systems. Spatial intravariability resulted from small errors in electrode placement on the thoracic surface. Temporal intravariability was determined by repeating the measurements for one subject on five consecutive days. Insignificant correlation coefficients were obtained between impedance sensitivity to lung ventilation and either age, height, weight, or chest-to-back distance of the subject. Intra-and intersubject variability were found to be of the same size for a given lead system. While the significant spatial intervariability can be easily correlated with local resistance changes due to lung volume shifts, the intersubject variability did not lend itself to correlation with subject somatotype variables.
The decline of communist power: Elements of a theory of institutional change

There is considerable irony in the current search for the causes of the rapid political changes sweeping the communist world after 1988. In retrospect, it is not hard to single out a number of macrosocietal trends that led eventually to regime change: economic stagnation and consumer deprivation, deeply eroded commitment to official ideology and the growth of widespread cynicism, the corruption and weakening of the apparatus of rule, and the gradual enlargement of autonomous, self-organized spheres of social and intellectual life. It is ironic, however, that each of these macrosocietal developments, now the cornerstones of emerging explanations of rapid political change, were only recently treated as evidence of the remarkable comparative stability of communist regimes throughout the world in the last half-century. Economic inefficiency, consumer deprivation, and housing shortages were well evident in these societies for decades. The official ideology of these regimes was long met with public indifference and private derision. The party apparatus for decades operated as a collection of local political machines founded upon venality and patronage. Beginning as early as the mid-1950s, observers noted a gradual enlargement of tolerated private spheres of independent intellectual and political discourse: today's independent political groups are the descendants of yesterday's dissidents; and yesterday's dissidents are the descendents of yesteryear's prison camp inmates. While today we can look back upon an inexorable cumulative crisis; a few years ago one could just as easily be struck by how little all of these deeply rooted problems seemed to shake these stable and stagnant regimes.
Recovery of 1,3-, 2,3-dichloropropenes, 1,2-dibromo-3-chloropropane, and o-, p-dichlorobenzenes from fatty and non-fat foodstuffs by liquid extraction technique.

Food samples including fatty, non-fatty, grainbased, and nongrain-based types were fortified with the following five nematocides and fumigants: 1,3-dichloropropene, 2,3-dichloropropene, 1,2-dibromo-3-chloropropane,o-dichlorobenzene, andp-dichlorobenzene. Then, depending on sample consistency and type, the samples were diluted in, or extracted with organic solvent such as isooctane. A few of the high-fat extracts were passed through Florisil® to remove excess fat or endogenous interferences. Analysis of the initial or cleaned up extracts was done by gas chromatography (GC) at 90°C. The dichloropropenes were determined on 20% OV-101 columns with electron-capture and Hall electroconductivity detectors. The dichlorobenzenes and 1,2-dibromo-3-chloropropane, which elute beyond 30 min on the above columns, were determined on 5%-loaded columns using the same detectors. All five analytes were recovered from these techniques. Mean analyte recovery following a direct dilution or extraction was 83%, and following the Florisil® cleanup step, was 52%. In 1986, a fumigant survey of about 200 foodstuffs by using this overall technique gave no findings of the five compounds studied here.
Role of an apical K,Cl cotransporter in urine formation by renal tubules of the yellow fever mosquito (Aedes aegypti)

The K,Cl cotransporters (KCCs) of the SLC12 superfamily play critical roles in the regulation of cell volume, concentrations of intracellular Cl−, and epithelial transport in vertebrate tissues. To...
Kinetics of submonolayer and multilayer epitaxial growth

Abstract An introductory review of the central ideas in the kinetics of submonolayer and multilayer epitaxial growth is followed by a more detailed discussion of some recent developments in the field. The concepts of a critical island size, dynamical scaling of the island-size distribution, and the barrier to interlayer diffusion (Ehrlich-Schwoebel barrier) are introduced. The results of kinetic Monte Carlo simulations of a realistic model of submonolayer epitaxial growth are presented and compared with rate-equation analyses and recent experiments. We also present an analytical expression for the scaled island-size distribution as a function of the critical island size which agrees well with our simulations as well as with experiments. Our results provide a quantitative explanation for the variation of the submonolayer island density, critical island size, island-size distribution and morphology as a function of temperature and deposition rate found in recent experiments. We also present the results of a realistic model for multilayer growth which includes a finite barrier to interlayer diffusion. A method for determining the Ehrlich-Schwoebel barrier based on a comparison of simulations with experimental results for the reflection high-energy electron diffraction intensity, surface width, layer densities, and surface morphology is discussed. In particular, we find that for Fe Fe(100) the interlayer diffusion barrier is significantly less than the activation energy for diffusion on a flat terrace.
Correspondence principles and a generalized J integral for large deformation and fracture analysis of viscoelastic media

Methods of quasi-static deformation and fracture analysis are developed for a class of nonlinear viscoelastic media and sample applications are given. Selection of the class of media is guided by actual rheological behavior of monolithic and composite materials as well as the need for simplicity to be able to understand the effect of primary material and continuum parameters on crack growth behavior. First, pertinent aspects of J integral and energy release rate theory for nonlinear elastic media are discussed. Nonlinear viscoelastic constitutive equations are then given, and correspondence principles which establish a simple relationship between mechanical states of elastic and viscoelastic media are developed. These principles provide the basis for the subsequent extension of J integral theory to crack growth in viscoelastic materials. Emphasis is on predicting mechanical work available at the crack tip for initiation and continuation of growth; some examples show how viscoelastic properties and the J integral affect growth behavior. Included is the problem of a crack in a thin layer having different viscoelastic properties than the surrounding continuum. The Appendix gives an apparently new constitutive theory for elastic and viscoelastic materials with changing microstructure (e.g. distributed damage) and indicates the conditions under which the fracture theory in the body of the paper is applicable.
On coil–stretch transitions in dilute polymer solutions

In this paper we examine molecular stretching in the inception of uniaxial elongational flow of dilute polymer solutions. The polymer molecules are modeled as bead–spring chains with finitely extensible nonlinear elastic springs, and we use the Peterlin approximation. This work is distinguished from earlier work because we model the macromolecules with chains instead of dumbbells, and we examine the time dependence of three average quantities describing the chain conformation in unsteady flows: root‐mean‐square end‐to‐end distance, root‐mean‐square extensions of the individual links, and mean moment of inertia about the axis of elongation. We observe a gradual transition from the coiled equilibrium state of the chain to the stretched state after the inception of strong uniaxial elongational flow, and we describe the nature of this transition which takes place in roughly four stages: I equilibrium coil; II deformed coil; III spring stretched (‘‘locally unraveled’’); and IV unfolded chain. Inclusion of hydrodynamic interaction changes the macromolecular response quantitatively but not qualitatively.
Cross-layer optimization made practical

Limited resources and time-varying nature of wireless ad hoc networks demand optimized use of resources across layers. Cross-layer optimization (CLO) for wireless networks, an approach that coordinates protocol behaviors at different layers with a goal to maximize a utility function, has received considerable attention lately. However, most existing work remains as theory and no practical CLO based on utility optimization exists today. The main difficulties in implementing theoretical CLO designs arise often from impractical assumptions about the characteristics of the wireless medium and also from computational and communication overhead of proposed solutions to achieve or approximate the optimality. In contrast, many existing practical approaches for CLO (not necessarily utility optimization) are rather ad hoc in nature and developed mostly based on intuitions. Thus, a clear gap between theory and practice in CLO exists. This paper addresses this dichotomy to close the gap by taking an optimal solution from utility-based CLO and applying practical approximation to enable a practical implementation in a wireless mesh network where nodes are statically positioned in an ad hoc fashion. We focus on the utility of maximizing throughput. We identify the impractical or computationally-intensive components of a theoretically-derived optimal throughput-maximizing solution and then propose, in most cases, practical approximation with O(1) complexity for MAC, scheduling, routing and congestion control. The result is a practical CLO solution that approximates the theoretically-derived optimal solution, but achieves much improved performance over existing practical CLO implementations.
Compact spectrometer based on a disordered photonic chip

Light scattering in disordered media has been studied extensively due to its prevalence in natural and artificial systems. In photonics most of the research has focused on understanding and mitigating the effects of scattering, which are often detrimental. For certain applications, however, intentionally introducing disorder can actually improve device performance, as in photovoltaics. Here, we demonstrate a spectrometer based on multiple light scattering in a silicon-on-insulator chip featuring a random structure. The probe signal diffuses through the chip generating wavelength-dependent speckle patterns, which are detected and used to recover the input spectrum after calibration. A spectral resolution of 0.75 nm at a wavelength of 1,500 nm in a 25-μm-radius structure is achieved. Such a compact, high-resolution spectrometer is well suited for lab-on-a-chip spectroscopy applications. A miniature spectrometer has been developed that employs light scattering in a photonic chip with a random structure. It generates wavelength-dependent speckle patterns, which are detected and analysed to recover the spectrum of the input signal. It has a resolution of 0.75 nm in the 1,500 nm wavelength region.
Continuity of pediatrician: new support for an old shibboleth.

An experimental design permitted comparison of ambulatory pediatric care in a traditional comprehensive clinic with similar care in an experimental clinic emphasizing continuity of physician. The results of a survey of all staff and a sample of patients' mothers indicated that provision of pediatrician continuity yields higher staff and client satisfaction, better patient-practitioner relationships, and greater efficiency. It is suggested that such an arrangement be made a requirement in pediatric clinic programs. Implications of the findings for further research are discussed.
A new RISM integral equation for solvated polymers

Abstract A new RISM integral equation suitable for treating solute-solvent interactions when the solute contains periodicity is presented. The essential feature is the introduction of a new intramolecular correlation function for the solute, which is a sum of the intramolecular correlation functions in the old theory over the periodic cells of the solute. The theory can be used to study polyelectrolyte properties in solution, including solvent effects on biopolymers. As a first application, simple models are considered in which atoms are arranged along a linear chain and on a helix. The results are compared with computer simulations for a linear chain of ions in water.