cssi/SciSciGPT-SciSciNet huggingface dataset:
Kidney stone incidence and metabolic urinary changes after modern bariatric surgery: review of clinical studies, experimental models, and prevention strategies.

Bariatric surgery has been associated with increased metabolic kidney stone risk and post-operative stone formation. A MEDLINE search, performed for articles published between January 2005 and November 2013, identified 24 pertinent studies containing 683 bariatric patients with 24-hour urine profiles, 6,777 bariatric patients with kidney stone incidence, and 7,089 non-stone forming controls. Of all procedures reviewed, only Roux-en-Y gastric bypass (RYGB) was linked to post-operative kidney stone development, increasing stone incidence two-fold in non-stone formers (8.5%) and four-fold in patients with previous stone history (16.7%). High quality evidence from 7 studies (n=277 patients) before and after RYGB identified the following post-RYGB urinary lithogenic risk factors: 30% reduction in urine volume (the main driver of urinary crystal saturation), 40% reduction in urinary citrate (a potent stone inhibitor), and 50% increase in urinary oxalate (a stone promotor). Based on this, a summary of strategies to reduce calcium oxalate stone risk following RYGB is provided. Furthermore, recent experimental RYGB studies are assessed for insights into the pathophysiology of oxalate handling, and the literature in gut anion (oxalate) transport is reviewed. Finally, as a potential probiotic therapy for hyperoxaluria, primary data from our laboratory is presented, demonstrating a 70% reduction in urinary oxalate levels in four experimental RYGB animals after colonization with Oxalobacter formigines, a non-pathogenic gut commensal that uses oxalate as an energy source.Overall, urine profiles and kidney stone risk following bariatric surgery appear modifiable by dietary adjustments, appropriate supplementation, and lifestyle changes. For hyperoxaluria resistant to dietary oxalate restriction and calcium binding, well-designed human investigations are needed to identify additional means of lowering urinary oxalate, such as Oxalobacter colonization or empiric pyridoxine therapy. Further investigations are also needed to determine tolerability and compliance of stone prevention strategies, such as citrate supplementation and hydration, in this population.
Difference in conformation of fibrinogen degradation products as revealed by hydrogen exchange and spectropolarimetry

Abstract 1. 1.|Bovine fibrinogen was treated with plasmin for 24 h. Two degradation products of high molecular weight (Fragments D and E) were isolated. Their conformation in 0.3 M NaCl at pH 7.5 was compared with that of fibrinogen using hydrogen exchange and spectropolarimetry. 2. 2.|Hydrogen-deuterium and hydrogen-tritium exchange both revealed that the exchange of peptide hydrogen atoms was slower in Fragment D and faster in Fragment E than that in fibrinogen throughout the reaction. 3. 3.|Data derived from ultraviolet optical rotatory dispersion and from far ultraviolet circular dichroism indicated that Fragments D and E contained more α-helical structure (approximately 40% and 34%, respectively) than does fibrinogen (approximately 32%). Near ultraviolet circular dichroic spectra suggested similar conformations for Fragment D and fibrinogen; Fragment E appears to differ and may contain other structural chromophores in addition to the α-helix. 4. 4.|It has been concluded that proteolytic degradation of fibrinogen splits off a considerable portion of disordered structure. The remaining high molecular weight degradation products differ in conformation. Fragment E seems to be a loosely assembled molecule with hydrophylic character and penetrable conformation. Fragment D however, seems to be a compact molecule with hydrophobic character retaining a great part of the native conformation of fibrinogen.
Energetics and bias-dependent scanning tunneling microscopy images of Si ad-dimers on Ge(001)

We report an ab initio study of the energetics and scanning tunneling microscopy (STM) images of Si ad-dimers on Ge(001) and energetics of Ge ad-dimers on Si(001). As in the case of Si dimers on Si(001), we find for both systems that the D dimer configuration, lying between the substrate dimer rows and parallel to them, is highest in energy. Conversely, recent STM experiments for Si ad-dimers on Ge(001) deduce the D configuration to be most stable. Our theoretical STM images for this system find that both the D and C configurations (the latter also between the rows) have similar STM images for the experimental voltages. We propose an experimental test (low-bias STM imaging) which would unambiguously distinguish between the D and C configurations.
Assessing the VANET's Local Information Storage Capability under Different Traffic Mobility

Wireless networking enabled vehicles can form vehicular ad hoc mesh networks (VMeshs). Using cooperative communication among VMeshs, a local transient information could be "retained" within a given geographic region for a certain period of time, without any infrastructure help. In this paper, we study this "storage capability" of VMeshs. We analyze the scenarios of highway traffic (both one-way and two-way highway free flow traffic) and vehicular traffic in a city environment. For highway traffic, we study different properties of the "VMesh storage", using a simulation tool that accurately models the freeway vehicular mobility. For city traffic, we first perform simulations based on real traffic trace of San Francisco Yellow Cabs. Then we compare the results with the scenario where a general Random Way Point (RWP) mobility model is used. Our results show that transmission range has high impact on the storage lifetime for one-way highway traffic, and the size of the region in which we want the information stored has high impact for two-way highway traffic. For city-wide traffic, the storage's lifetime generated using San Francisco Yellow Cab trace is shorter than that obtained using the RWP mobility model. This is due to the regular movement of the cabs as compared to the random vehicle movement in the RWP mobility model.
'Wireless networks without edges': Dynamic radio resource clustering and user scheduling

Cellular systems using Coordinated Multi-Point (CoMP) transmissions leveraging clusters of spatially distributed radio antennas as Virtual Base Stations (VBSs) have the potential to realize overall throughput gains and, perhaps more impor- tantly, can deliver substantial enhancement to poor performing "edge" users. In this paper we propose a novel framework aimed at fully exploiting the potential of such systems through dynamic radio resource clustering and user scheduling which maximize system utility. The dynamic clustering problem is modeled as a maximum weight clustering problem which is NP- hard, however, we show that by structuring the set of possible VBSs to be "2-decomposable" it can be efficiently computed. We also propose to optimize over a class of power allocation policies to radio resources, and thus VBSs, which allow dynamic user scheduling and flexible power allocations depending on instantaneous channel realizations. We use simulation to compare our approach with a state-of-the-art baseline which exploits dynamic frequency reuse and opportunistic user scheduling, but no clustering, and show edge users' throughput gains are as high as 80% without degrading the performance of others. I. INTRODUCTION
A simple method for constructing phase envelopes for multicomponent mixtures

Abstract A simple method for constructing vapor—liquid equilibrium phase envelopes is described. Dew and bubble points are calculated throughout the critical and retrograde regions by stepping around the envelope in suitably small increments of T or P . The technique is simpler than previous methods because the dew and bubble points are determined by iterating on a single variable through the entire critical region. Criteria are presented which allow determination of whether this iteration variable should be T or P . Phase envelopes, together with critical points, cricondentherms and cricondenbars, have been calculated using this method for ten different mixtures.
Establishing Operating Limits in a Commercial Lean Premixed Combustor Operating on Synthesis Gas Pertaining to Flashback and Blowout

Operability issues such as flashback and lean blow out are phenomena that must be addressed for successful commercial operation of stationary gas turbines. The present work focuses on flashback and lean blow out of premixed jet flames in a combustor from a commercially available gas turbine operating on synthesis gas compositions. The issue of flashback is exacerbated when operating on fuels with high hydrogen content due to the increased reactivity of hydrogen, thus increasing the propensity for flashback. Operating margins for mixtures of natural gas and carbon monoxide in hydrogen are reported. The results interestingly demonstrate reduced stability for mixtures of H2/NG than for H2/CO. Increasing H2 percentage from 0% to 100% reduced blowout equivalence ratios from Φ = 0.63 to Φ = 0.29 for H2/NG and Φ = 0.42 to Φ = 0.29 for H2/CO. In addition, results obtained for inlet temperatures of 300K and 623K are compared and show an upward shift of the stability limits for higher preheats. Modeling of the experimental data using a perfectly stirred reactor predicts the effect of the addition of H2 to natural gas on the blowout limits. With regards to flashback some key factors that dominate the characteristics are identified and attempts to correlate data are carried out. The results show that lean blowout and flashback occur at the same AFT, regardless of preheat temperatures. AFT at flashback and lean blowout are compared to a more fundamental burner [1] with results indicating reasonable scalability.Copyright © 2012 by ASME
Mixing supersymmetry and family symmetry breakings

We present a toy model in which the Higgs sector fields transform as non-Abelian representations of a family symmetry group, and consider the possibility that the extra family partners of the Higgs particles act as messengers for both supersymmetry and family symmetry breakings. Although such mediation schemes generically produce family dependent soft supersymmetry breaking terms at the messenger scale, we demonstrate the existence of a focusing mechanism which may erase such hierarchies through renormalization group running.
Phase III trial comparing whole-pelvic versus prostate-only radiotherapy and neoadjuvant versus adjuvant combined androgen suppression: Radiation Therapy Oncology Group 9413.

Purpose: This trial tested the hypothesis that combined androgen suppression (CAS) and whole-pelvic (WP) radiotherapy (RT) followed by a boost to the prostate improves progression-free survival (PFS) by 10% compared with CAS and prostate-only (PO) RT. This trial also tested the hypothesis that neoadjuvant and concurrent hormonal therapy (NCHT) improves PFS compared with adjuvant hormonal therapy (AHT) by 10%. Materials and Methods: Eligibility included localized prostate cancer with an elevated prostate-specific antigen (PSA) ≤ 100 ng/mL and an estimated risk of lymph node (LN) involvement of 15%. Between April 1, 1995, and June 1, 1999, 1,323 patients were accrued. Patients were randomly assigned to WP + NCHT, PO + NCHT, WP + AHT, or PO + AHT. Failure for PFS was defined as the first occurrence of local, regional, or distant disease; PSA failure; or death for any cause. Results: With a median follow-up of 59.5 months, WP RT was associated with a 4-year PFS of 54% compared with 47% in patients treated wit...
Effect of Stem Termination on Soybean Traits in Southern U.S. Production Systems

Southern U.S. soybean [Glycine max (L.) Merr.] are primarily determinate and are grown in a diverse array of environments. Understanding the yield response of different plant types to southern environments may lead to improved yield. Our objective was to determine if varying stem termination could increase yield in some environments. Eleven pairs of isolines varying for determinate and indeterminate growth habit were derived from two crosses. All lines and controls were grown at two locations for 2 yr, planted in May and June and with or without irrigation. Seven pairs were grown for a third year. Yield, height, lodging, and maturity data were collected. In all crosses and production systems, determinate lines were shorter, earlier maturing, and had less lodging than indeterminate lines. Yields of determinate and indeterminate lines were equal in all irrigation-planting date combinations. There was a trend for determinate lines to yield better than indeterminate lines with early planting and irrigation. The yield difference between growth habits was conditioned primarily by a complex interaction of random genetic and environment effects. The indeterminate growth habit may confer a yield advantage over the determinate growth habit in environments with limited yield and growth potential. This was due to the lower yield response to increasing environment productivity of indeterminate vs. determinate lines. Perhaps 10 to 15% of southern production environments have conditions where indeterminate types may yield better than determinate types. The yield advantage of indeterminate types in such environments appears small. The success of deploying indeterminate cultivars to low-yield, low-growth southern environments to maximize yield will depend on accurately predicting where these environments will occur.
Market approaches to education: Vouchers and school choice

Abstract The debate over educational vouchers has heated up in recent years, but there has been little empirical evidence on the many issues. The purpose of this article is to set the background for that debate and introduce a number of original empirical works of recent vintage on issues of market choice. These include studies of choice and payment by results in England and Scotland as well as econometric simulation and case studies of public choice and public/private choice in the U.S.A. In addition, there are four essay reviews of recent books on public and market choice and a theoretical attempt to explain why public and private schools have similar curriculum and organization.
A Nonlinear Signal Analysis Scheme for Localization of a Moving Acoustic Source

The synthesis of coupled systems including linear propagation media and nonlinear lumped subsystems is investigated. The resulting coupled system is expected to exhibit improved dynamic behavior. Such improvements are sought after by designing exclusively the lumped nonlinear subsystem and not by modifying the propagation medium. The lumped subsystem can be static or dynamic as well as passive or active. The design method is based on the Volterra-Wiener theory of nonlinear systems combined with the Linear Fractional Transformation employed for the analysis of uncertain linear systems. Although the techniques are applicable to a variety of practical engineering and physical systems, this work addresses acoustic source localization. Indeed, a moving acoustic source can be considered to nonlinearly modify the characteristics of a carrier acoustic wave. Such an acoustic carrier might be a monochromatic or polychromatic tone as well as other broadband signals such as band-limited white or colored noise. The sound source position signal is propagated through a nonlinear operator and then, under noise-free environment assumptions, determines the sound pressure level at the receiver location. In this paper, the proposed method is applied to the simplified case of a one-dimensional acoustic cavity defined by totally reflective barriers. Furthermore, the lossless wave equation is assumed to govern the sound pressure level in the homogeneous domain of interest. However, even in this simple scenario, only the additional assumptions of negligible source velocity and acceleration allow the derivation of an expression for the sound pressure level containing exclusively source displacement. In this context, simulation data series or analytical solutions, approximate or exact, are post-processed in order to determine the Volterra kernels, which effectively are a convenient extension of the impulse response concept in the nonlinear case, of the operator connecting source displacement to sound pressure level at the receiver. The outcome is Linear Time Invariant models depicting the dominant sound propagation dynamics. Then the synthesis stage is based on the properties of interconnected nonlinear systems that are described in the Volterra-Wiener framework. By using such properties, the signal processing algorithm for the estimation of the acoustic source position based on the received sound pressure level is finally developed.Copyright © 2009 by ASME
Cardinality, completeness, and decomposability of sets of endpoints of chainable continua

Abstract In this paper, we construct chainable continua called zigzags. These provide us with examples of decomposable and indecomposable continua with three or more endpoints. By using these zigzags, we can also show that the set of endpoints may or may not be complete.
Linewidths of the electronic excitation spectra of donors in silicon

The excitation spectra of phosphorus, arsenic, isolated interstitial lithium, and lithium oxygen donors in silicon have been investigated under the high resolution of a Fourier-transform spectrometer. Using a "strain-free" mounting technique, the linewidths are observed to be much narrower than those reported earlier in the literature; the observed linewidths appear to be limited by the "lifetime" effects. The linewidths and shapes of the excitation lines of phosphorus donors in silicon, introduced by the nuclear transmutation of $^{30}\mathrm{Si}$ into $^{31}\mathrm{P}$ by the capture of a slow neutron followed by a ${\ensuremath{\beta}}^{\ensuremath{-}}$ decay, are studied; the influence of the charged defects produced by neutron irradiation is demonstrated and explained in terms of the electric fields due to charged impurities and defects.
Vaccines for viral hemorrhagic fevers--progress and shortcomings

With a few exceptions, vaccines for viruses that cause hemorrhagic fever remain unavailable or lack well-documented efficacy. In the past decade this has not been due to a lack of the ability to develop vaccine platforms against highly pathogenic viruses, but rather the lack of will/interest to invest in platforms that have the potential to become successful vaccines. The two exceptions to this are vaccines against Dengue virus (DENV) and Rift Valley fever virus (RVFV), which recently have seen significant progress in putting forward new and improved vaccines, respectively. Experimental vaccines for filoviruses and Lassa virus (LASV) do exist but are hindered by a lack of financial interest and only partially or ill-defined correlates/mechanisms of protection that could be assessed in clinical trials.
Clinical system for simultaneous external superficial microwave hyperthermia and cobalt-60 radiation

A system for simultaneous thermoradiotherapy was devised to investigate the possible benefits and/or complications of thermal radiosensitization in human superficial tumours. The system combines the well-known treatment modalities of external 915 MHz microwave hyperthermia and cobalt-60 teletherapy. Single waveguide applicators are utilized either attached to blocking trays, so that the gamma beam travels through a waveguide and into the patient (en face setup), or in a conventional way with the microwave propagation vector orthogonal to the gamma beam (orthogonal setup). With these setups a radiation fraction can be delivered in the middle of a 60-min, non-interrupted hyperthermia treatment. Temperatures and power level are remotely monitored and recorded outside the Cobalt room. Extensive measurements and testing showed that the operation of the hyperthermia system (generator, applicators, thermometry unit and temperature sensors) was not disrupted by irradiation and that the microwaves were confined to...
Novel actions of cardiac ankyrin repeat protein

Abstract Gene expression profiling of mouse skin wounds has led to the discovery of numerous target genes that may have therapeutic or diagnostic value. Cardiac ankyrin repeat protein (CARP, ankrd1 ) expression is markedly and persistently elevated in cutaneous wounds. This article provides a summary and perspective on CARP with particular reference to tissue repair. CARP plays a role as a nuclear transcription co-factor in many cell types including vascular endothelium. It is also a structural component of the sarcomere. CARP transcription is active in cardiogenesis and muscle injury, and in the latter context, ankrd1 is under complex regulation by cytokines, hypoxia, doxorubicin and other forms of stress. We have investigated the pharmacology of CARP in wounds by adenoviral gene transfer. Overexpression of CARP leads to a high vascular density, consistent with multiple effects on endothelial behavior. The activity of CARP makes it a novel candidate gene in tissue repair.
H-2 alleles contribute to antigen 85-specific interferon-gamma responses during Mycobacterium tuberculosis infection.

Abstract The in vitro immune responses to mycobacterial antigens have been linked to the H-2 loci in mice. We evaluated in vitro and in vivo immune responses during early Mycobacterium tuberculosis ( M.tb ) pulmonary infection of C57BL/6 (H-2 b ), C57BL/6 (H-2 k ), CBA/J (H-2 k ), and C3H/HeJ (H-2 k ) mice to determine H-2 k -dependent and -independent effects. H-2 k -dependent effects included delayed and diminished Ag85-specific Th1 cell priming, a reduced frequency of Ag85-specific IFN-γ producing cells, reduced IFN-γ protein in vivo, and increased M.tb lung burden as demonstrated by C57BL/6 H-2 k mice vs. C57BL/6 mice. H-2 k -independent factors controlled the amount of Ag85-specific IFN-γ produced by each cell, T cell numbers, granuloma size, and lymphocytic infiltrates in the lungs. Overall, these results suggest that an H-2 k -dependent suboptimal generation of Ag85-specific cells impairs control of early M.tb growth in the lungs. H-2 k -independent factors influence the potency of IFN-γ producing cells and immune cell trafficking during pulmonary M.tb infection.
Transient response of ground surface due to incident SH waves

The amplification of ground motion on the surfaces of two semi-elliptical alluvial valleys due to incident SH waves in homogeneous and layered half-spaces is investigated in time as well as in frequency domains by using a hybrid method combining the finite element discretization of the near-field with boundary integral representation of the far-field outside a contour enclosing completely the scatterers. First, the response in frequency domain is obtained from solving a set of large sparse unsymmetric complex matrix equations, which are stored in a compacted data structure, by the biconjugate gradient method with good initial guess, and then it is transformed into the time domain by using FFT. An efficient quadrature scheme is adopted to compute the Green's functions in a layered half-space. The study shows that an important role is played by the trapped surface waves (Love waves) that produce much larger amplification than the disturbance associated with the direct incident signal. These Love waves can propagate inside the valley back and forth resulting in a long duration when the impedance contrast is high. In the lower impedance contrast case, the Love waves produce disturbances on the outer sides of the valley. The P and SV cases will be presented in another paper.
Bias and efficiency loss due to categorizing an explanatory variable

It is a common situation in biomedical research that one or more variables are known to be associated with the outcome of interest. Researchers often discretize some variables and fit a regression model using these discretized variables. Although convenient for illustration purposes, such an approach can be biased and lead to loss of efficiency. In this article, we consider the situation of a regression model with two explanatory variables under an assumption of multivariate normality. We investigate the effect of dichotomizing or categorizing one variable on the estimate of the coefficient of the other continuous variable and on prediction from the models. Algebraic expressions are presented for the asymptotic bias and variance of the coefficient of the continuous explanatory variable and for the residual sum of squares for prediction. Some numerical examples are presented in which we find that the bias of the coefficient of the continuous explanatory variable is always smaller for the categorized model than that for the dichotomized model. The size of the test of a zero coefficient for the continuous variable only depends on the correlations between the response variable, the discretized variable, and the continuous variable. The size of the test for the categorized model is always smaller than for the dichotomized model, however, both can differ substantially from the nominal level if the correlation between the response and the categorical variable or between the two explanatory variables is high. The (predictive) relative efficiency of models also only depends on correlations amongst the three variables. There is a substantial loss of efficiency due to categorization if the correlation between the categorized and response variable is high. The predictive relative efficiency is always higher for the categorized model. The relative predictive efficiency due to dichotomization depends on the choice of cut points, with the least loss of efficency being achieved at the median.
Potential Use of Dylox and Other Insecticides in a Control Program for Field Crop Pests in California

Dylox® ( O,O -dimethyl 2,2,2-trichloro-1-hydroxyethylphosphonate) and several standard insecticides were evaluated for effectiveness on a rather wide range of insects damaging field crops in California. At varying dosages Dylox was effective in controlling the following pests on alfalfa hay: Alfalfa caterpillar, Colias philodice eurytheme Bdv.; webworm, Loxostege spp.; beet armyworm, Laphygma exigua. (Hbn.); and variegated cutworm, Peridroma margaritosa (Haw.). On seed alfalfa Dylox gave high mortalities of lygus bugs, Say stink bug, Chlorochroa sayi Stal, and Euschistus sp. In addition to the above-mentioned pests on seed alfalfa, on cotton Dylox was effective on cotton leaf perforator, Bucculatrix thurberiella Busck, salt-marsh caterpillar, Estigmene acrea (Drury), and was promising for control of southern garden leafhopper, Empoasca Solana DeL., and omniverous leafroller, Platynota stultana Wlshm. This chemical gave suits when applied to cotton for control of cabbage looper, Trichoplusia ni (Hbn.), and bollworm, Heliothis zea (Boddie). In general, the residual period of toxic activity in the field lasted only a few days. Dylox residues on alfalfa hay were below 1 p.p.m. 4 days after application at dosages of as much as 1 pound per acre. Only trace amounts were detected 10 days after application. Dylox was no more effective than some of the other compounds evaluated. In view of the fact, however, that it is relatively nontoxic to honey bee, Apis mellifera L., populations and, depending upon dosage applied, less toxic to most entomophagous arthropods than many chemicals currently in use, Dylox appears to be a potentially useful compound for use on many California field crops.
Self-assembly of a bis-urea macrocycle into a columnar nanotube

A bis-urea macrocycle 1 was synthesized and shown to form extended nanotubular columns by X-ray crystallography.
INFLUENCE OF AN SiO2/CYCLOHEXANE INTERFACE ON THE PHOTOCHEMISTRY OF ANTHRACENE

We have investigated the effect of added Si02 on the photochemistry of anthracene, 1, in cyclohexane. Adsorption of 1 onto the Si02 surface from cyclohexane follows a Freundlich adsorption isotherm indicating interactions between 1 and the surface over a distribution of adsorption sites. In the absence of oxygen, addition of Si02 to a cyclohexane solution of 1 leads to a significant increase in the rate of photolysis without a large concomitant change in product identity. The 9,10-photodimer of 1 is the major product under oxygen-deficient conditions. In the presence of oxygen, added Si02 has dramatic effects on both the photoproduct distribution and the kinetics of photodecomposition. The complicated mixture of oxygenated products formed from photolysis in oxygen-containing slurries is proposed to arise from thermal decomposition of a single primary photoproduct, anthracene-9,10-endo-peroxide. The polarity/polarizability of the Si02/cyclohexane interface is considered to be a major factor influencing the rate of photolysis in the oxygenated Si02/cyclohexane slurries.
Optical conductivity of aluminum

Abstract Energies and wave functions obtained from a recent band calculation are used in a computation of the interband optical conductivity of aluminum. The results are combined with a Drude term and compared with experiment.
Characterizing weekly self-reported antihypertensive medication nonadherence across repeated occasions.

BACKGROUND Little is known about weekly variability in medication nonadherence both between and within persons. PURPOSE To characterize medication nonadherence across repeated, closely spaced occasions. METHODS This prospective cohort study comprised four unannounced telephone assessment occasions, each separated by approximately 2 weeks. On each occasion, adult outpatients taking at least a single antihypertensive medication completed a measure of extent of, and reasons for, nonadherence. RESULTS Two hundred and sixty-one participants completed 871 (83%) of 1,044 occasions. Nonadherence was reported on 152 (17.5%) of 871 occasions by 93 (36%) of 261 participants. The most commonly endorsed reasons for nonadherence were forgetting (39.5%), being busy (23.7%), and traveling (19.7%). Among 219 participants completing at least three occasions, 50% of the variability in extent of nonadherence was a result of within-person fluctuations, and 50% was a result of between-person differences. CONCLUSION Interventions to reduce nonadherence should be informed by variability in the extent of nonadherence and specific reasons for nonadherence.
Control of Persistent Nonequilibrium Adsorbed Polymer Layer Structure by Transient Exposure to Surfactants

By adsorbing polymers in the form of polymer/surfactant complexes, it is possible to control the nonequilibrium structure of adsorbed polymer layers. At moderate NaCI concentrations, the extent of poly(ethylene oxide )-b-( propylene oxide)-b-(ethylene oxide) triblock copolymer adsorption to silica surfaces is increased by a sequential sodium dodecyl sulfate (SDS) complex coadsorption procedure, when compared to the extent of adsorption in the absence of surfactant. The complex adsorption procedure entails polymer/ surfactant complex formation and coadsorption at high SDS concentrations, followed by SDS dilution and eventually complete SDS removal, while maintaining a constant polymer concentration in solution. The amount of polymer that remains adsorbed after the complex adsorption procedure is nearly 40% greater than the amount that ordinarily adsorbs for the same polymer concentration in the absence of surfactant. We use independent atomic force microscopy and streaming current techniques to measure the polymer layer thicknesses. Both techniques indicate that polymer layers that were produced by the complex adsorption procedure followed by thorough rinsing in surfactant-free polymer solutions are significantly denser than the ordinary layers produced by adsorption in the absence of surfactant. Layers produced by complex adsorption contain more mass per unit area but are only approximately 70% as thick as the ordinary layers. The differences between the two adsorption procedures persist even during continued bathing of the layers in identical surfactant-free polymer solutions for 6 h. Polymer/surfactant complex adsorption thereby provides a tool for guiding adsorbed polymer layers into persistent nonequilibrium structures that might not be accessible by ordinary adsorption procedures.
Distribution of births in an abrupt sequence: a stochastic model

A probability model for the distribution of number of births in a time segment (T0, T0 + T), where T0 is a distant time point since the start of the process, has been derived. The provision that birth propensities in the process of human reproduction may change over time has been considered. The model is illustrated with a set of observed data.
Guided inference of nested monotone Boolean functions

This paper addresses the problem of minimizing the average query complexity of inferring a pair of nested monotone Boolean functions defined on {0, 1}n using a pair of oracles. Here, nested refers to the case when one of the functions is always greater than or equal to the other function. It is shown that the nested case is equivalent to inferring the single function case defined on {0, 1}n+1 when access to the two oracles is unrestricted. Two common examples of restricted oracles, namely sequential oracles and a single three-valued oracle, are also analyzed. The most efficient known approach to minimizing the average query complexity in inferring a single monotone Boolean function is based on a query selection criterion. It is shown that the selection criterion approach is easily modified for use with restricted oracles. Several real world examples illustrate the necessity and sufficiency of the nested monotone Boolean function model. Extensive computational results indicate that the nestedness assumption reduces the average query complexity by a few percent. This is a dramatic improvement considering the fact that this complexity is exponential in n.
Trends in Substandard Housing 1940–1980

“A decent home and a suitable living environment for every American family” has remained an elusive goal since it was first stated by Congress in the Housing Act of 1949. This owes in large part to the difficulty of translating the goal into practical definitions of housing objectives, and of developing reasonably precise estimates of U.S. housing quality, especially as these estimates may be changing over time. This paper discusses the difficulties involved in measuring housing (in)adequacy, reviews previous definitions of U.S. housing quality, and delineates a measure of housing inadequacy. Then, based upon this current measure, the numbers of inadequate housing units are calculated for 1973–1978 (years for which complete Annual Housing Survey data are available), melded with the traditional measure of “substandard” housing for the years 1940–1970, and predicted for 1979–1980 (years for which only core AHS data were currently available). The study's principal findings are twofold: First, The U.S. housing stock has shown a fairly steady improvement in average quality during the last forty years, a trend that appears to be continuing. Second, while the search for better measures of housing quality must continue, HUD's current definition of physically inadequate housing represents the state of the art and, with proper calibration, provides a reasonably consistent basis for measuring U.S. housing quality over time.
Regarding asymmetric induction on the schift bases: a correction

Abstract The condensation of racemic 2-norbornanone and chiral α-phenylethylamine has been shown to produce four diastereomeric Schiff bases rather than only one as previously reported.
Price of technology. A blind spot.

WE ARE responsible for knowing the risks and benefits of the care we recommend. But we often do not know the price, especially for new technology. Researchers usually report new technology in our journals without mention of the expected charges. Patients are seldom concerned with the price of technology when the charges are covered by third-party payers. There are problems with price. It varies with marketplace, regulations, and negotiations. It may not reflect the true value of a service. It does not reflect the nonmedical expenses of seeking care, indirect costs of morbidity, or the intangible costs of suffering. 1 Despite these problems, we need to consider the charges that are used to measure health care expenses and transfers of wealth in our society. Others certainly do it for us. 2 Debate over payment for health services begins when we know the charges. The Case of Photopheresis for Systemic Sclerosis
In Situ Redox Manipulation by Dithionite Injection: Intermediate-Scale Laboratory Experiments.

The goal of in situ redox manipulation (ISRM) is to create a permeable treatment zone capable of removing redox-sensitive contaminants from ground water. The objective of this study was to evaluate the effectiveness of one promising ISRM technology: chemical reduction of aquifer sediments by sodium dithionite (Na{sub 2}S{sub 2}O{sub 4}) injection. The technology was evaluated in intermediate-scale laboratory experiments designed to investigate the kinetics of Fe(III)-reduction and dithionite-disproportionation reactions in a radial flow field over similar transport distances ({approximately}7 m) and time scales ({approximately}72 hours) as those used in a field trial for remediation of chromate contaminated ground water at the Department of Energy Hanford site in Washington state. Four hundred liters ({approximately} 1 pore volume) of 0.1 M Na{sub 2}S{sub 2}O{sub 4} in a 0.4 M K{sub 2}CO{sub 3}/0.04 M KHCO{sub 3} buffer were injected at a rate scaled to field values. Dithionite breakthrough curves at sampling ports were approximately described by the advection-dispersion equation with a two-part reaction model containing first-order rate coefficients for dithionite reaction with sediment Fe(III) (k{sub 1} = 0.13 hr{sup {minus}1}) and dithionite disproportionation (k{sub 2} = 0.05 hr{sup {minus}1}). Analyses on sediment cores collected from the physical model indicated that substantial Fe(III) wasmore » reduced to Fe(II) and that the dithionite-treated sediment was capable of removing 2 mg/L chromate from {approximately} 100 column pore volumes of synthetic ground water. These results indicate that the ISRM technology is a potentially feasible method for removing chromate from Hanford ground water.« less
Quantum chemical and RRKM/master equation studies of cyclopropene ozonolysis

Abstract The cycloalkene–ozone reaction impacts atmospheric chemistry as a non-photochemical source of hydroxyl radical ( OH) and as a source of secondary organic aerosol. Unlike in the ozonolysis of acyclic alkenes, the Criegee Intermediates (CI’s) formed in cycloalkene ozonolysis retain all of the energy released in the reaction, enabling these CI’s to access reaction pathways with high activation barriers. We used CBS-QB3, MCG3, RRKM/master equation, and transition state theory (TST) calculations to perform a detailed analysis of cyclopropene ozonolysis, treating all possible conformers of all intermediates and transition structures (TS’s). The total TST rate constant for O3 cycloaddition to cyclopropene is 2.3 × 10−14 cm3 molecule−1 s−1, with ∼90% of the reaction proceeding through the endo TS. We predict that ∼35% of chemically activated syn CI’s will cyclize to dioxiranes, even though the barriers against dioxirane formation are 5–12 kcal mol−1 higher than the barriers against the 1,4-hydrogen shift that leads to vinyl hydroperoxides and OH. This helps reduce the predicted OH yield for cyclopropene ozonolysis to 44%. We also predict ∼20% of either the endo primary ozonide (PO) or its syn CI derivatives will isomerize to the exo PO or anti CI’s. Further work is required to predict the extent to which these reactivity patterns apply to the ozonolysis of larger cycloalkenes.
Stimulated electronic Raman and hyper-Raman scattering in potassium vapor

Abstract Stimulated electronic Raman scattering and hyper-Raman processes in potassium vapor near the D 1 and D 2 lines have been observed using a stable resonator and pulsed laser excitation. First and second order Stokes and anti-Stokes lines were observed simultaneously and independently for a pump laser tuning range exceeding 70 cm −1 . The output energy increases by more than a factor of 10 3 as the potassium concentration increases from 0.25 to 2.2×0 16 cm −3 . When the pump is tuned between the K D 1 and D 2 lines, an efficient hyper-Raman process dominates with a slope efficiency that exceeds 10%. The threshold for the hyper-Raman process is about 6 mJ per pulse, or 3.8 MW/cm 2 peak intensity. This Raman shifted laser may be useful as a target illuminator or atmospheric compensation beacon for a high power diode pumped alkali laser.
Effects of suppressing the DNA mismatch repair system on homeologous recombination in tomato

In plant breeding, the ability to manipulate genetic (meiotic) recombination would be beneficial for facilitating gene transfer from wild relatives of crop plants. The DNA mismatch repair (MMR) system helps maintain genetic integrity by correcting base mismatches that arise via DNA synthesis or damage, and antagonizes recombination between homeologous (divergent) DNA sequences. Previous studies have established that the genomes of cultivated tomato (Solanum lycopersicum) and the wild relative S.lycopersicoides are substantially diverged (homeologous) such that recombination between their chromosomes is strongly reduced. Here, we report the effects on homeologous recombination of suppressing endogenous MMR genes in S.lycopersicum via RNAi-induced silencing of SlMSH2 and SlMSH7 or overexpressing dominant negatives of ArabidopsisMSH2 (AtMSH2-DN) in an alien substitution line (SL-8) of S. lycopersicoides in tomato. We show that certain inhibitions of MMR (RNAi of SlMSH7, AtMSH2-DN) are associated with modest increases in homeologous recombination, ranging from 3.8 to 29.2% (average rate of 17.8%) compared to controls. Unexpectedly, only the AtMSH2-DN proteins but not RNAi-induced silencing of MSH2 was found to increase homeologous recombination. The ratio of single to double crossovers (SCO:DCO ratio) decreased by approximately 50% in progeny of the AtMSH2-DN parents. An increase in the frequency of heterozygous SL-8 plants was also observed in the progeny of the SlMSH7-RNAi parents. Our findings may contribute to acceleration of introgression in cultivated tomato.
Life Role Salience Dimensions and Mental Health Outcomes Among Female Expatriate Spouses in Turkey

Using life role salience theory, we investigated the extent to which occupational, parental, marital, and home care roles explained mental health outcomes among female expatriate spouses. Participants (N = 86) were from English-speaking Northern American or Western European countries; the average age was 38. Results of a two-way within-subject analysis of variance suggested that the occupational role was least important. In a comparison of role expectations, participants had greater value for (than commitment to) their parental role; the reverse was true for the marital role. Results of a path analysis explained 10% of the variance in psychological distress via a direct path from career role importance (β = .14) and an indirect path from the marital role importance through marital satisfaction (β = −.12). Three paths (parental role importance, β = .14; home care role importance, β = .15; indirectly from marital role importance through marital satisfaction, β = .18) explained 24% of the variance in psychol...
Warfarin maintenance dose in older patients: higher average dose and wider dose frequency distribution in patients of African ancestry than those of European ancestry.

Abstract Studies report that warfarin doses required to maintain therapeutic anticoagulation decrease with age; however, these studies almost exclusively enrolled patients of European ancestry. Consequently, universal application of dosing paradigms based on such evidence may be confounded because ethnicity also influences dose. Therefore, we determined if warfarin dose decreased with age in Americans of African ancestry, if older African and European ancestry patients required different doses, and if their daily dose frequency distributions differed. Our chart review examined 170 patients of African ancestry and 49 patients of European ancestry cared for in our anticoagulation clinic. We calculated the average weekly dose required for each stable, anticoagulated patient to maintain an international normalized ratio of 2.0 to 3.0, determined dose averages for groups 80 years of age and plotted dose as a function of age. The maintenance dose in patients of African ancestry decreased with age ( P P = 0.006) and 52% in the >80-year-old group (33.2 ± 1.7 vs. 21.8 ± 3.8 mg; P = 0.011). Therefore, 43% of older patients of African ancestry required daily doses > 5 mg and hence would have been under-dosed using current starting-dose guidelines. The dose frequency distribution was wider for older patients of African ancestry compared to those of European ancestry ( P
Implicit language equations: existence and uniqueness of solutions

We introduce a new type of language equation, namely implicit equations, and derive a number of properties which clearly demonstrate that the behavior of implicit equations differs substantially from that of conventional or explicit ones. Explicit language equations express each variable as a regular expression in terms of their variables and constant languages; implicit language equations express constant languages as regular expressions in terms of their variables and constant languages. An algorithm is given for determining a solution of a given system of implicit language equations, if one exists, provided all constant languages are regular and the operations permitted in the regular expressions are unrestricted union and concatenation from the left by a constant. A characterization of the uniqueness of a solution of such a system and a method for determining all solutions are also provided.
Usefulness of Subnormal Midwall Fractional Shortening in Predicting Left Ventricular Exercise Dysfunction in Asymptomatic Patients With Systemic Hypertension

Abstract We have recently shown that a subgroup of asymptomatic hypertensive patients exhibit subnormal left ventricular (LV) midwall fiber shortening at rest and that this finding predicts morbidity and mortality independently of age, blood pressure (BP), or the presence of LV hypertrophy. However, it is unknown whether abnormal midwall fractional shortening predicts either subnormal LV functional reserve or extracardiac damage in asymptomatic hypertensive patients. Accordingly, we compared radionuclide cineangiographic LV ejection fraction at rest and maximum exercise as well as clinical findings between 89 patients with normal and 16 patients with subnormal midwall fractional shortening by echocardiogram. Patients with low midwall fractional shortening were similar in gender, age, and systolic BP to those with normal shortening but had higher mean diastolic BP and body mass indexes (both p Radionuclide cineangiographic left ventricular (LV) ejection fraction at rest and maximum exercise were compared between 89 patients with normal and 16 patients with subnormal midwall fractional shortening by echocardiogram. Patients with subnormal midwall fractional shortening had higher LV mass and were more likely to have subnormal (