cssi/SciSciGPT-SciSciNet huggingface dataset:
Beta-Adrenergic Stimulation Increases the Intra-SR Ca Termination Threshold for Spontaneous Ca Release in Cardiac Myocytes

In the heart, beta-adrenergic stimulation is associated with pro-arrhythmic Ca waves that occur as the result of the sarcoplasmic reticulum (SR) Ca content reaching a critical threshold level. Recently, we have shown that beta-adrenergic stimulation increases the intra-SR Ca threshold for Ca wave initiation, potentially serving as a protective mechanism against pro-arrhythmic Ca release during beta-adrenergic stimulation (Domeier et al., 2012). However, data regarding the termination of such release and details on the regulation of this process have yet to be elucidated. In this study we directly and dynamically measured the intra-SR Ca level ([Ca]SR) at which spontaneous Ca waves terminate (termination threshold) under control conditions and during beta-adrenergic stimulation. Application of the beta-adrenergic receptor agonist isoproterenol (ISO; 1 μM) resulted in an increase in basal [Ca]SR. Importantly, in the presence of ISO the [Ca]SR at which spontaneous Ca waves terminated was also increased compared to control conditions. In addition, the depletion amplitude of spontaneous Ca waves was decreased in the presence of ISO compared to control conditions. When [Ca]SR was subsequently lowered in the presence of ISO to that observed under control conditions (by reducing extracellular Ca and partially inhibiting SERCA with cyclopiazonic acid or thapsigargin), the [Ca]SR at which spontaneous release terminated was still increased compared to control conditions. Likewise, the depletion amplitude remained decreased compared to control conditions. These data indicate that during beta-adrenergic stimulation in the heart, both the intra-SR Ca threshold at which spontaneous Ca waves initiate and terminate is increased, while the amount of Ca released during Ca waves is decreased. The Ca wave termination level may represent an important mode of altering diastolic Ca wave amplitude, and thus, the arrhythmogenic potential of the cell during acute beta-adrenergic stimulation.
A new technique for efficient and accurate analysis of arbitrary 3D FSSs, EBGs and Metamaterials

In this paper we present a new numerically efficient and accurate technique for the analysis of doubly-infinite periodic arrays of elements, which find applications as Frequency Selective Surfaces (FSSs), Electronic Bandgap (EBGs) structures and Metamaterials (MTMs). The principal advantages of the proposed method, which is not based on the use of the Periodic Boundary Condition (PBC), are its versatility—since it can analyze 3D inhomogeneous elements—and its ability to handle arbitrary incidence angles in an efficient way, regardless of how large that angle is. It is well known that the Finite Difference Time Domain (FDTD)/PBC runs into difficulties for wide angles—requiring large computation times and becoming unstable for such angles.
Graphical data modeling methods using ceres plots

Identification of curvature in regression models is an important aspect of data analysis. Partial residual plots have played a major role. Recently, Cook developed a new class of plots, called CERES plots, that includes partial residual plots. Implementation of these plots necessitates modeling the relationships between certain covariates. If these relationships are linear, a partial residual plot is obtained. However, if the relationships are nonlinear, the more general CERES plot is obtained. Here, we describe an implementation of interactive methods which construct CERES plots.0
Effects of Heat and Noise on Helping Behavior

48 male and 48 female undergraduates were given an opportunity to aid a confederate both before and after exposure to ambient temperatures of either 73°F (23°C) or 95°F (35°C), and noise levels of 55 dB(A), 95 dB(A) without perceived control, or 95 dB(A) with perceived control. Although heat produced discomfort and led to negative evaluations of the environment and although noise generally increased arousal, neither heat nor noise influenced any measures of helping behavior. Results are discussed in terms of feelings of perceived control imparted by the informed consent procedures and in terms of internal versus external attributions of responsibility for negative feelings.
Case history of a cyst

The case history of a periapical lesion, probably a cyst, observed over a period of 44 years without endodontic treatment is presented. The radiographic appearance of the lesion changed somewhat over the years, and external root resorption became evident. There is no history of fistula, and the tooth remained asymptomatic during the 44 years.
Small Energy Scale for Mixed-Valent Uranium Materials

We investigate a two-channel Anderson impurity model with a ${5f}^{1}$ magnetic and a ${5f}^{2}$ quadrupolar ground doublet and a ${5f}^{2}$ excited triplet. Using the numerical renormalization group method, we find a crossover to a non-Fermi-liquid state below a temperature ${T}^{*}$ varying as the ${5f}^{2}$ triplet-doublet splitting to the 7/2 power. To within numerical accuracy, the nonlinear magnetic susceptibility and the ${5f}^{1}$ contribution to the linear susceptibility are given by universal one-parameter scaling functions. These results may explain ${\mathrm{UBe}}_{13}$ as mixed valent with a small crossover scale ${T}^{*}$.
Operating decisions, supplier availability and quality: An empirical study

Abstract In the just-in-time (JIT) philosophy, purchasing strategies advocate the use of fewer sources of supply to enable a firm to improve the quality of its products. However, there is paucity of empirical evidence in support of the theory. We develop a model by integrating concepts from manufacturing, marketing, and business strategy to better understand the links between operating decisions of the firm, supplier availability, and product quality. We empirically test the hypotheses using cross-sectional PIMS data. Our analysis shows that operating decisions and environmental factors such as wider product lines, lower levels of competition, and greater frequency of product changes increase the likelihood of a firms' reduction of supplier base, which in turn raises quality levels.
The mucin of bovine sublingual glands.

Abstract Extracts of bovine sublingual glands were fractionated and the materials (mucin) responsible for the viscous stringy properties of the extracts were extensively purified. The progress of purification was followed by electrophoretic, ultracentrifugal and viscometric measurements. The purest product contained 23.3 per cent N-acetyl-hexosamine, 17.8 per cent sialic acid, 7.6 per cent 6-deoxyhexose, 20.6 per cent hexose (as galactose), and about 25 par cent protein. The molar ratios were approximately: hexosamine, 2; sialic acid, 1; 6-deoxyhexose, 1; hexose as galactose, 2. The electrophoretic mobility of the product was −4.6 × 10 −5 cm 2 /sec/V at pH 7.4, ionic strength 0.1. The sedimentation constant was 8.6 S in the same buffer. The composition of the mucin clot was also investigated and found to be a dissociable mucoprotein. The mucin appears to act as one of the anionic components in the formation of the mucin clot. The purest mucin itself gave no clot by adjustment of the pH to 3.5 except in the presence of added serum albumin.
The importance of postsecondary training for welfare to work: Initiatives at the community college of aurora

This chapter discusses postsecondary training programs and services for welfare recipients at a Colorado community college.
Application of Rhodamine 800 for Reversed Phase Liquid Chromatographic Detection Using Visible Diode Laser-Induced Fluorescence

This study reports the application of rhodamine 800, a far-red dye, suitable for excitation using visible diode laser-induced fluorescence (VDLIF) detection. A reagent synthesized from rhodamine 800 was evaluated as a precolumn reagent for derivatization with amino-containing analytes. The derivative of this reagent with primary amine analytes showed a loss of fluorescence. Rhodamine 800 was then applied as a mobile phase additive in the indirect mode for quantitation of valproic acid in plasma using reversed phase HPLC in combination with VDLIF detection. A visible diode laser (output power 8.50 mW) temperature-tuned to oscillate at 674.70 nm was used as a light source for a laboratory constructed HPLC fluorescence detector. A liquid/liquid extraction procedure was applied to human blank plasma. The selectivity of this method was validated by demonstration of a lack of interfering peaks in extracts of plasma (n = 3 sources). A calibration curve for valproic acid between 40 and 200 μg/mL was shown to be l...
Sonochemical dechlorination of hazardous wastes in aqueous systems

Physical processes resulting from ultrasonication of aqueous solutions and suspensions produce extreme conditions that can affect the chemistry of dissolved and suspended chemicals. The purpose of this work was to explore the use of sonochemistry in treating chlorinated chemicals in water. The compounds examined for susceptibility to aqueous sonochemical transformation were chlorpyrifos, 3,3{prime},4,4{prime}-tetrachloroazoxybenzene, 2-chlorobiphenyl, 2,4,8-trichlorodibenzofuran, lindane (hexachlorocyclohexane, {gamma}-isomer), hexachlorobenzene, aldrin, and a complex mixture of chlorinated olefins, paraffins, and aromatics from a Louisiana Superfund Site. It was fond that many chemicals were dechlorinated and/or otherwise transformed by sonochemical treatment under minimal conditions. Evidence for sonochemical transformation and dechlorination of the target chemicals and mixtures was obtained from controlled experiments measuring (1) increases in titratable chloride from sonochemical treatment, (2) decreases in pH, (3) changes in aqueous phase UV/visible absorption spectra, (4) changes in aqueous electrochemistry, and (5) generation of sonolysis products and/or decreases in target compounds vs appropriate control in internally standardized GC-MS analysis of extracts.
Massive Hemoptysis: Pathogenesis and Management:

Massive hemoptysis is a life-threatening complication of many pulmonary disorders, and it occurs most com monly in association with longstanding inactive tuber culosis, bronchiectasis, lung abscess, bronchogenic car cinoma, and fungal disease. It is generally a neovascular change or local erosive effect of chronic pulmonary dis ease and may originate from either bronchial or pulmo nary circulation. Recurrent bleeding is unpredictable; therefore, diagnostic and therapeutic intervention must be undertaken with urgency. The immediate priorities must be protection of the airway to the nonbleeding lung and localization of the site of hemorrhage prefera bly by bronchoscopy, which has a high yield when per formed during active hemorrhage. Immediate control of bleeding may be obtained by local tamponade with a balloon-tipped Fogarty catheter, use of a double-lumen endotracheal tube, or angiographically guided emboliza tion. Surgical resection is the preferred definitive treat ment for those who meet operative cri...
Growth Promotion in Broilers by Copolymer CRL87-61

Abstract CRL87-61 is one of a series of nonionic block copolymers which are being developed for use in human and animal medicine. Recent studies have suggested that this compound holds potential as a growth promoter in broiler chickens. Our report details results of further investigation of the efficacy of copolymer CRL87-61 as a growth promoter in broilers. The study consisted of independent field trials in Colorado, Maryland and Mississippi. Results confirmed that CRL87-61 is a growth promoter in broilers: a dietary level of 10 ppm caused an average increase of 2.85% in 42 day body weights, an average improvement of 1.66% in feed conversion, and an average decrease of 0.31% in mortality rate when compared to untreated (control) birds. Improved production parameters were also noted when birds fed 10 ppm of CRL87-61 were compared to broilers that received Bacitracin only.
Early dark adaptation, the receptor potential and lateral effects on the retina.

Abstract The rapid threshold drop in early dark adaptation has been found to slow, following saturating adaptation levels in the rod monochromat, and following cone-saturating flashes in normal subjects. This supports the idea that early dark adaptation reflects the decay of the receptor potential to the adapting light, but contrast effects also influence the shape of the early dark adaptation curve. It is proposed that early dark adaptation reflects both receptor potential decay and loss of lateral effects following an adapting light. Variations of curve shapes are discussed from this point of view, with their theoretical significance.
Use of Serum Procalcitonin in Evaluation of Febrile Infants: A Meta-analysis of 2317 Patients

Abstract Background Serum procalcitonin (PCT) concentrations have been studied as a diagnostic test for serious bacterial infections (SBIs) in children. However, the utility of a single measurement in the evaluation of SBIs in febrile infants younger than 91 days is not clear. Objective Use a systematic review and meta-analysis to determine: 1) the ability of serum PCT concentrations to identify febrile infants Methods The literature search identified studies of febrile infants segregated into risk groups using serum PCT concentrations. Some authors were contacted to provide subgroups Results Seven studies encompassing 2317 patients were identified; five of seven studies used a PCT discriminating concentration of 0.3 ng/mL. No heterogeneity or publication bias was identified. The overall relative risk (RR) was 3.97 (95% confidence interval [CI] 3.41–4.62) and was consistent by sensitivity analysis. The RR from a systematic review of clinical prediction rules was 30.6 (95% CI 7.0–68.13) and 8.75 (95% CI 2.29–15.2) for infants untreated and treated with antibiotics, respectively. Conclusions Alone, measurement of serum PCT concentrations, though able to identify a group of young infants at risk for SBIs, is inferior to the available clinical prediction rules for identifying young, febrile infants at risk for SBIs. Serum concentrations ≤ 0.3 ng/mL may be helpful as an add-on test to current rules for identifying low-risk, febrile infants.
An efficient method for generating unaliased samples of certain signals

In simulating a continuous-time system being driven by a continuous-time signal f(t), we may wish to generate a discrete-time signal whose spectrum agrees with that of f(t) for frequencies up to the Nyquist frequency. One important example is provided by the simulation of the vocal tract driven by a triangularly shaped glottal pulse, although a similar problem arises whenever we simulate a known continuous-time input to a system. We define classes of signals, called H-synchronous signals, which, after sampling, can be "de-aliased" with a fixed digital filter depending on H. The McClellan-Parks-Rabiner algorithm is used to find FIR designs for such de-aliasing filters for the important special cases of piecewise-constant and piecewise-linear signals.
Polyacrylates containing hexafluoroisopropoxy pendant functions

Abstract A series of new polyacrylates was synthesized by incorporating the hexafluoroisopropoxy unit pendant to the backbone. The fluorinated monomers were synthesized by reacting 4-fluoro(2-hydroxyhexafluoroisopropyl)benzene with acrylic or methacrylic acid chlorides. The polymers were obtained by bulk, free-radical polymerization techniques using α,α′-azobisisobutyronitrile as initiator. The polymers had viscosities ranging from 0.15 to 1.41 dl g −1 and had good film-forming properties. Thermogravimetric analysis showed that they had thermal stability up to 370°C in N 2 ; glass transition temperatures were in the range 64 to 119°C.
Really arguing with your computer in natural language

Recently, the computer science community has been hearing a lot about "fifth generation" computers and the Japanese large-scale project to build intelligent software that can "think," "reason," and "understand human languages." It is in the field of artificial intelligence (AI) where such intelligence machines and programs are being designed and created. How far along is the field of AI? How close are AI programs to being able to "reason" or "understand" as humans do? This paper is intended to give scientists outside the field of AI some insight about the problems, issues, and current status of computational models of human argumentation.
Testing for Variation in Animal Preference for Jesup Tall Fescue Hays with Wild‐Type, Novel, or No Fungal Endophyte

ABSTRACTTall fescue [ Schedonorus phoenix (Scop.) Holub.] is an important source of forage but often con-tains a fungal endophyte [ Neotyphodium coeno-phialum (Morgan-Jones and Gams) Glenn, Bacon, and Hanlin] that can produce alkaloids and decrease anmi al perf ormance. Removing the endophyte can reduce agronomic performance and persistence. An improved cultivar (‘Jesup’) with a novel (nontoxic) endophyte (trademark “MaxQ”) has improved agronomic performance. Persistence may be related to agronomic traits and animal feeding preferences. We tested for variation in animal preference among two har-vests by testing each of three hays made from Jesup tall fescue that varied in endophyte sta-tus (no endophyte, containing the novel endo-phyte, or containing a wild-type endophyte that produces alkaloids associated with toxicosis). We tested for preference using goats ( Capra hir-cus ), sheep ( Ovis aries ), and cattle ( Bos taurus ). All possible pairs were tested using traditional analysis of variance as well as multidimensional scaling. Multidimensional scaling of the animal preferences indicated that two dimensions were being used to rank the hays. The fi rst dimension for all three animal species was related to varia-tion in forage nutritive value. The second dimen-sion was not correlated with any of the measured variables. Endophyte status was not a factor in the preferences expressed by the three animal species. It appears that no effective feedback mechanism exists related to endophyte status.D.S. Fisher, USDA-ARS, 1420 Experiment Station Rd., Watkinsville, GA 30677; J.C. Burns, USDA-ARS and Dep. Crop Science and Dep. Animal Science, North Carolina State Univ., Raleigh, NC 27695. Cooperative investigation of the USDA-ARS and the North Carolina ARS, Raleigh, NC 27695-7643. The use of trade names does not imply endorsements by USDA-ARS or by the North Carolina ARS of the products named or criticism of similar ones not mentioned. Received 3 Oct. 2007. *Corresponding author (Dwight.Fisher@ars.usda.gov).
Morphologic response of the rabbit cortical collecting tubule to peritubular hypotonicity: quantitative examination with differential interference contrast microscopy.

The isolated and perfused cortical collecting tubule of the rabbit was examined by differential interference contrast microscopy in order to characterize the morphologic response of this nephron segment to peritubular hypotonicity. Computer-assisted, morphometric procedures were developed to obtain measurements of cell volume and lateral intercellular space geometry from interference contrast images of perfused nephron segments. Following dilution of the bath from 290 to 190 mOsm in the absence of antidiuretic hormone (T=25°C), the cells swelled rapidly to a new steady-state volume which was maintained for at least 20 to 30 min and which was about 90% of that predicted for ideal osmometric behavior. The increase in cell volume was accomplished entirely by bulging of the cells into the lumen; lateral space width and outside tubule diameter were unaffected by peritubular hypotonicity. In addition, the swelling of the cells was associated with an apparent swelling of intracellular organelles, e.g., nuclei and mitochondria. Our results indicate that cells of the mammalian collecting tubule swell without the capacity for significant volume regulation at 25°C and without the cytoplasmic vacuolation and dilation of the lateral intercellular spaces observed following the onset of antidiuretic hormone-dependent volume reabsorption (E. Ganote, J. Grantham, H. Moses, M. Burg and J. Orloff,J. Cell Biol.36:355, 1968).
Effect of anelastic and scattering structures of the lithosphere on the shape of local earthquake coda

A simple model of single acoustic scattering is used to study the dependence of the shape of local earthquake coda on the anelastic and scattering structures of the lithosphere. The model is applied to the coda of earthquakes located near Stone Canyon, central California, and provides an explanation for the features observed in the data, which include an interesting temporal variation in the coda shape. A surficial layer with aQ of 50 and thickness of 10 or 25 km underlain by a zone with aQ of 1000 extending to the bottom of the lithosphere, together with a scattering scale length,a, that varies with depthz according to the relationa=0.3 exp[-(z/45)2] are found to constitute the simplest structure of the medium compatible with the coda data and with body and surface wave attenuation data. The profile of heterogeneity sizes implies that the scattering strength increases strongly with depth, a constraint required by the necessity to boost the energy of the later coda without forcing the intrinsicQ to be excessively high in the uppermost mantle. This constraint is viewed as an artifact of the single scattering model which overstimates the scattering coefficient due to the neglect of multiple scattering. The observed temporal variation of the signal is difficult to explain by a simple change of the intrinsicQ at some depth. Rather, it is suggested that the scattering properties at depth changed with time through a variation of the fractional rms velocity fluctuation on the order of one percent.
Identity matching of consonant-vowel-consonant words by prereaders.

Using an identity matching-to-sample procedure, normally developing prereaders who matched individual letters with high accuracy (e.g., m and s) did not show high accuracy in matching three-letter printed words that differed only in the first letter (e.g., mad and sad). Teachers and researchers should not assume that children who can discriminate individual letters can also discriminate minimally different words that contain those letters.
Immediate and long-term posttherapy neuropsychologic performance in children with acute lymphoblastic leukemia treated without central nervous system radiation

Intellectual and neuropsychologic test performance was studied in 41 children with acute lymphoblastic leukemia within one year of completing multidrug therapy in which intrathecal methotrexate was the sole agent of central nervous system prophylaxis. To control for possible effects of intensive systemic chemotherapy and the disruptive psychosocial effects of treatment on psychometric test function, 33 children with embryonal rhabdomyosarcoma who had no CNS disease or treatment were similarly studied. All patients studied had been in continuous complete remission since diagnosis. Within each diagnostic group, patients were placed in a younger (less than 8 years) or an older (more than 8 years) group depending on age at the time of testing. No significant difference was found in intellectual function between the younger ALL and ERMS groups or between the total ALL and ERMS groups. Further five-year follow-up of 12 of the youngest ALL patients showed no significant long-term change in intellectual or other specific neuropsychologic functions. Children with ALL who remained in continuous complete remission from diagnosis and who were treated with prophylactic intrathecal methotrexate and no CNS radiation did not have global or specific neuropsychologic impairment.
Expanded porphyrins: The synthesis and metal binding properties of novel tripyrrane-containing macrocycles

Abstract Novel tripyrrane macrocycles have been prepared by the Schiff base condensation of 2,5-bis-(3-ethyl-5-formyl-4-methyl-pyrrol-2-ylmethyl)-3,4-diethylpyrrole and simple diamines. The structurally characterized macrocycle 1 forms 1:1 complexes with both Rh(I) and Zn(II) cations in which the metal is coordinated only to the imine nitrogens. In the presence of Cd(II) and oxygen, however, compound 1 is oxidized to the aromatic pentadentate ‘expanded porphyrin’ macrocycle 5, into which the metal cation is fully complexed.
CYP2C9 haplotype structure in European American warfarin patients and association with clinical outcomes.

Objective The goal of this study was to define the haplotype structure of the cytochrome P450 (CYP) 2C9 gene in a European American population and evaluate associations between CYP2C9 haplotypes and anticoagulation-related outcomes. Methods Genomic deoxyribonucleic acid from 192 European American patients stabilized on warfarin therapy was resequenced across 60 kilobases of the CYP2C9 genomic region, including all exons, dense sampling of introns, approximately 10 kilobases of the 5′-flanking region, and approximately 1.7 kilobases of the 3′-untranslated region. Results A total of 132 single nucleotide polymorphisms (SNPs) were detected, of which 47 were present in the 5′-flanking promoter region, 11 in the exonic coding region, and 74 in the intron regions. Nine nonsynonymous SNPs in the coding region consisted of CYP2C9*2, *3, *9, *11, and *12; R125H; and 3 new structural variants. Sixty SNPs were present at a minor allele frequency of greater than 5%, and from this subpopulation, 23 haplotypes were inferred. Clustering analysis identified 6 major groups of related haplotypes that were further designated 1A, 1B, 1C, 1D, 2, or 3. The *2 and *3 SNPs appeared exclusively in groups 2 and 3, and these groups combined were associated with significantly reduced warfarin maintenance doses, longer time to stable dosing, and increased risk of bleeding. In contrast, combinations of haplotypes 1A, 1B, 1C, and 1D were not associated with differences in any of these outcomes. Conclusion These data establish a whole-gene, high-resolution haplotype structure for CYP2C9 in a European American patient population and suggest that genetic variation in exons, rather than the promoter or other regulatory regions, is largely responsible for warfarin sensitivity associated with CYP2C9 variants in this population. Clinical Pharmacology & Therapeutics (2005) 77, 353–364; doi: 10.1016/j.clpt.2005.01.019
Data-parallel abstractions for irregular programs

Client-side applications running on multicore processors are likely to be irregular programs that deal with complex, pointer-based data structures such as graphs and trees. In her 2007 Turing award lecture, Fran Allen raised an important question about such programs: do irregular programs have data parallelism, and if so, how do we exploit it on multicore processors?In this talk, we demonstrate using concrete examples that irregular programs have a generalized data parallelism that arises from the use of iterative algorithms that manipulate worklists of various sorts. We also argue that optimistic parallelization is required for these programs since compile-time parallelization techniques like points-to and shape analysis cannot expose the parallelism in these programs.We then describe the approach taken in the Galois project to exploit this generalized data-parallelism. There are three main aspects to the Galois system: (1) a small number of syntactic constructs for packaging optimistic parallelism as iteration over ordered and unordered sets, (2) assertions about methods in class libraries, and (3) a runtime scheme for detecting and recovering from potentially unsafe accesses to shared memory made by optimistic computations. We present experimental results that demonstrate that the Galois approach is practical, and discuss ongoing work on this system.
Fetal growth rates and the very preterm delivery of twins.

Objective Our objective was to determine whether slow fetal growth rates and twin growth patterns from 20 weeks' gestation to delivery are associated with very preterm delivery. Study design Available charts were reviewed for twin pregnancies, delivered between 1979 and 2002, at 4 U.S. medical centers. The sample of 1612 pregnancies delivered at 28 week's gestation or greater and had at least 2 ultrasound evaluations of fetal size from 20 to 28 weeks or from 28 weeks to delivery for estimation of fetal growth rates (grams per week). Slow fetal growth (below the 10th percentile) was defined as less than 90 grams per week at 20-28 weeks and 168 g/week from 28 weeks to delivery. The main outcome measure was the timing of delivery. Results Of the women delivering twins, 5.3% delivered extremely preterm (28-30 weeks), 8.5% very preterm (31-32 weeks), and 40.1% preterm (33-36 weeks). Patterns of growth for the pair were highly associated with very preterm delivery. Compared with neither growing slowly (1.7%), 4.9% delivered very preterm if only 1 twin grew slowly. Very preterm was 14.6% (adjusted odds ratio 9.81; 95% confidence interval, 3.50-27.48) with both growing slowly from 28 weeks on and 20.0% (adjusted odds ratio 15.04; 95% confidence interval 5.13-44.11) with both growing slowly over both intervals. Survival analyses indicated that twins with normal growth in both intervals remained undelivered for a significantly longer number of days ( P Conclusion Very preterm delivery of twins seems to be preceded by slowed or compromised fetal growth for the pair.
LCL124, a Cationic Analog of Ceramide, Selectively Induces Pancreatic Cancer Cell Death by Accumulating in Mitochondria

Treatment of pancreatic cancer that cannot be surgically resected currently relies on minimally beneficial cytotoxic chemotherapy with gemcitabine. As the fourth leading cause of cancer-related death in the United States with dismal survival statistics, pancreatic cancer demands new and more effective treatment approaches. Resistance to gemcitabine is nearly universal and appears to involve defects in the intrinsic/mitochondrial apoptotic pathway. The bioactive sphingolipid ceramide is a critical mediator of apoptosis initiated by a number of therapeutic modalities. It is noteworthy that insufficient ceramide accumulation has been linked to gemcitabine resistance in multiple cancer types, including pancreatic cancer. Taking advantage of the fact that cancer cells frequently have more negatively charged mitochondria, we investigated a means to circumvent resistance to gemcitabine by targeting delivery of a cationic ceramide (l-t-C6-CCPS [LCL124: ((2S,3S,4E)-2-N-[6′-(1″-pyridinium)-hexanoyl-sphingosine bromide)]) to cancer cell mitochondria. LCL124 was effective in initiating apoptosis by causing mitochondrial depolarization in pancreatic cancer cells but demonstrated significantly less activity against nonmalignant pancreatic ductal epithelial cells. Furthermore, we demonstrate that the mitochondrial membrane potentials of the cancer cells were more negative than nonmalignant cells and that dissipation of this potential abrogated cell killing by LCL124, establishing that the effectiveness of this compound is potential-dependent. LCL124 selectively accumulated in and inhibited the growth of xenografts in vivo, confirming the tumor selectivity and therapeutic potential of cationic ceramides in pancreatic cancer. It is noteworthy that gemcitabine-resistant pancreatic cancer cells became more sensitive to subsequent treatment with LCL124, suggesting that this compound may be a uniquely suited to overcome gemcitabine resistance in pancreatic cancer.
Measurements of the Triple Shock Wave/Turbulent Boundary-Layer Interaction

A joint experimental and computational study has investigated the flowfield structure created by three crossing oblique shock waves interacting with a turbulent boundary layer. Such an interaction is of practical importance in the design of high-speed sidewall-compression inlets. The interaction is created by a test model consisting of two vertical sharp fins mounted at 15-deg angle of attack to a horizontal flat plate. A third compression surface of 10-deg angle is mounted to the plate between the two vertical fins. The Mach 3.85 flowfield is examined experimentally through kerosene lampblack and planar laser scattering visualizations. The results are used to develop a flowfield model of the interaction structure. This structure is found to consist of a complex wave pattern overlying a viscous separated region. The presence of the 10-deg compression ramp reduces the severity of the boundary-layer separation compared to interactions created by the two fins alone. Additionally, the experimental flowfield data are compared with a computational solution using a modified κ-e (Rodi) turbulence model.
Investigating two-photon photophysics with fluorescence correlation spectroscopy

Fluorescence correlation spectroscopy (FCS) is a sensitive research tool for studying molecular dynamics at the single molecule level. Photophysical dynamics often dramatically influence FCS measurements, as we show here in characterizing the role of excitation saturation in two-photon fluorescence correlation measurements. We introduce a physical model that characterizes the influence of excitation saturation on the two-photon fluorescence observation volume, and derive an analytical expression for the correlation function that includes the influence of saturation. With this model, we can accurately describe both the temporal decay and the amplitude of measured fluorescence correlation functions over a wide range of illumination powers.
Role of Amines in Adhesion of Polybutadiene to Glass Substrates. III. Effect of Amines on the Reaction of Peroxide with Olefinic Groups.

Abstract An attempt to elucidate the role of amines in general, and of 3-aminopropyltriethoxysilane in particular, has been made through a study of the title subject by several different approaches. This paper describes a near infrared study of the influence of amines on the reactions of model olefins with dicumyl peroxide. The model olefins were chosen to be representative of typical internal and external double bonds found in polybutadiene. The study has shown that in addition to serving as radical traps the amines participate in other ways. Exactly what occurs depends on the structure of the amine.
Market Model of Financing Higher Education in Sub-Saharan Africa: Examples from Kenya

This paper examines some of the rationales for financial diversification and partial privatization of state universities in Kenya and the different manifestations of market-driven approaches to university education. It highlights the financial diversification activities at Kenya's state universities and raises key questions: Will the market model through financial diversification be able to creatively address the challenges of increased demand for higher education while ensuring that quality is maintained in Kenya's higher education 2 years form? Or will the market model lead to increased enrollment, providing quantity-driven education full of credentials but little academic value in terms of quality? Will students graduate with degrees without learning? Or will students graduate with both? How does the market model define students — are they clients, customers, or students?
The Role of VDAC in Cell Death: Friend or Foe?

As the voltage-dependent anion channel (VDAC) forms the interface between mitochondria and the cytosol, its importance in metabolism is well understood. However, research on VDAC's role in cell death is a rapidly growing field, unfortunately with much confusing and contradictory results. The fact that VDAC plays a role in outer mitochondrial membrane permeabilization is undeniable, however, the mechanisms behind this remain very poorly understood. In this review, we will summarize the studies that show evidence of VDAC playing a role in cell death. To begin, we will discuss the evidence for and against VDAC's involvement in mitochondrial permeability transition (MPT) and attempt to clarify that VDAC is not an essential component of the MPT pore (MPTP). Next, we will evaluate the remaining literature on VDAC in cell death which can be divided into three models: proapoptotic agents escaping through VDAC, VDAC homo- or hetero-oligomerization, or VDAC closure resulting in outer mitochondrial membrane permeabilization through an unknown pathway. We will then discuss the growing list of modulators of VDAC activity that have been associated with induction/protection against cell death. This article is part of a Special Issue entitled: VDAC structure, function, and regulation of mitochondrial metabolism.
A Tree Model for Pricing Convertible Bonds with Equity, Interest Rate, and Default Risk

Black and Scholes modeled stock options assuming the underlying stock was exposed to a single source of risk. Once it is recognized that both stocks and bonds are actually derivatives written on the underlying firm, many kinds of hybrid securities, like convertible bonds, are seen to have exposure to both stock market risk and interest rate risk. Further, as attention has turned to default as a critical risk, it is now apparent that properly valuing and risk-managing these instruments requires dealing formally with that third risk factor, as well. Developing tractable models for these cases seems like a daunting task, but Chambers and Lu present a lattice-based approach that does it. Their approach is easily implemented; it embeds important real world features of the problem, including correlation between stock price and interest rate changes; and it shares the advantage of other tree-based numerical methods, that increasing the number of time steps to improve accuracy does not cause execution time to explode in an unmanageable way. A real world example illustrates the use of the technique to price a convertible bond issued by Lucent.
Refined Solution Structure of the LpxC−TU-514 Complex and pKa Analysis of an Active Site Histidine: Insights into the Mechanism and Inhibitor Design†,‡

Lipopolysaccharide, the major constituent of the outer monolayer of the outer membrane of Gram-negative bacteria, is anchored into the membrane through the hydrophobic moiety lipid A, a hexaacylated disaccharide. The zinc-dependent metalloamidase UDP-3-O-acyl-N-acetylglucosamine deacetylase (LpxC) catalyzes the second and committed step in the biosynthesis of lipid A. LpxC shows no homology to mammalian metalloamidases and is essential for cell viability, making it an important target for the development of novel antibacterial compounds. Recent NMR and X-ray studies of the LpxC from Aquifex aeolicus have provided the first structural information about this family of proteins. Insight into the catalytic mechanism and the design of effective inhibitors could be facilitated by more detailed structural and biochemical studies that define substrate-protein interactions and the roles of specific residues in the active site. Here, we report the synthesis of the (13)C-labeled substrate-analogue inhibitor TU-514, and the subsequent refinement of the solution structure of the A. aeolicus LpxC-TU-514 complex using residual dipolar couplings. We also reevaluate the catalytic role of an active site histidine, H253, on the basis of both its pK(a) as determined by NMR titration and pH-dependent kinetic analyses. These results provide a structural basis for the design of more potent LpxC inhibitors than those that are currently available.
Probing gauge-mediated supersymmetry breaking models at the Fermilab Tevatron via delayed decays of the lightest neutralino

We quantitatively explore, in the context of the D0 detector at the Fermilab Tevatron, three very different techniques for observing delayed decays of the lightest neutralino of a simple gauge-mediated supersymmetry breaking (GMSB) model to photon plus gravitino. It is demonstrated that the delayed-decay signals considered can greatly increase the region of general GMSB parameter space for which supersymmetry can be detected. In the simple class of models considered, the combination of standard supersymmetry signals and delayed-decay signals potentially yields at least one viable signal for nearly all of the theoretically favored parameter space. The importance, for delayed-decay signal detection, of particular detector features and of building a simple photon detector on the roof of the D0 detector building is studied. {copyright} {ital 1998} {ital The American Physical Society}
Site-Specific Transformation of Drosophila via φC31 Integrase-Mediated Cassette Exchange

Position effects can complicate transgene analyses. This is especially true when comparing transgenes that have inserted randomly into different genomic positions and are therefore subject to varying position effects. Here, we introduce a method for the precise targeting of transgenic constructs to predetermined genomic sites in Drosophila using the ϕC31 integrase system in conjunction with recombinase-mediated cassette exchange (RMCE). We demonstrate the feasibility of this system using two donor cassettes, one carrying the yellow gene and the other carrying GFP . At all four genomic sites tested, we observed exchange of donor cassettes with an integrated target cassette carrying the mini-white gene. Furthermore, because RMCE-mediated integration of the donor cassette is necessarily accompanied by loss of the target cassette, we were able to identify integrants simply by the loss of mini-white eye color. Importantly, this feature of the technology will permit integration of unmarked constructs into Drosophila, even those lacking functional genes. Thus, ϕC31 integrase-mediated RMCE should greatly facilitate transgene analysis as well as permit new experimental designs.
Viscoelastic tissue mimicking phantom validation study with shear wave elasticity imaging and viscoelastic spectroscopy

Acoustic radiation force-based shear wave elasticity (SWE) methods are used to characterize soft tissue pathologies by quantifying tissue viscoelastic (VE) properties. To adequately evaluate SWE methods measurements of VE properties, it is important to characterize VE properties of tissue mimicking phantoms with an independent method. In this study a VE tissue mimicking phantom was developed and its concentration was modified to vary the shear viscosity. Three VE phantoms were studied with SWE and hyper frequency viscoelastic spectroscopy (HFVS). The VE properties were quantified by fitting a Kelvin-Voigt fractional derivative model to the measured shear wave speed. The mean shear elasticity of the three phantoms was from 3.4 to 3.7 kPa, the mean shear viscosity was from 1.7 to 17.4 Pa•s and the power of the fractional derivative model varied from 0.6 to 0.9.
Transforming Growth Factor-beta (TGF-β) Binding to the Extracellular Domain of the Type II TGF-β Receptor: Receptor Capture on a Biosensor Surface Using a New Coiled-coil Capture System Demonstrates that Avidity Contributes Significantly to High Affinity Binding

Mature TGF-beta isoforms, which are covalent dimers, signal by binding to three types of cell surface receptors, the type I, II and III TGF-beta receptors. A complex composed of the TGF-beta ligand and the type I and II receptors is required for signaling. The type II receptor is responsible for recruiting TGF-beta into the heteromeric ligand/type I receptor/type II receptor complex. The purpose of this study was to test for the extent that avidity contributes to receptor affinity. Using a surface plasmon resonance (SPR)-based biosensor (the BIACORE), we captured the extracellular domain of the type II receptor (TbetaRIIED) at the biosensor surface in an oriented and stable manner by using a de novo designed coiled-coil (E/K coil) heterodimerizing system. We characterized the kinetics of binding of three TGF-beta isoforms to this immobilized TbetaRIIED. The results demonstrate that the stoichiometry of TGF-beta binding to TbetaRIIED was one dimeric ligand to two receptors. All three TGF-beta isoforms had rapid and similar association rates, but different dissociation rates, which resulted in the equilibrium dissociation constants being approximately 5pM for the TGF-beta1 and -beta3 isoforms, and 5nM for the TGF-beta2 isoform. Since these apparent affinities are at least four orders of magnitude higher than those determined when TGF-beta was immobilized, and are close to those determined for TbetaRII at the cell surface, we suggest that avidity contributes significantly to high affinity receptor binding both at the biosensor and cell surfaces. Finally, we demonstrated that the coiled-coil immobilization approach does not require the purification of the captured protein, making it an attractive tool for the rapid study of any protein-protein interaction.
Metastatic Leydig Cell Tumor With Sarcomatoid Differentiation

Abstract Leydig cell tumors of the testis are uncommon. Only about 10% of cases have a malignant course. It has been stated that the only definite criterion for malignancy is presence of metastasis. We present a 47-year-old patient with metastatic Leydig cell tumor 17 years after initial diagnosis, to our knowledge the longest reported interval between diagnosis and the development of metastasis. The primary tumor did not exhibit convincing features of malignancy. The initial metastasis in the right perirenal fat tissue showed a biphasic tumor with sarcomatoid differentiation not described previously in a metastatic Leydig cell tumor.
An Organization-Driven Approach for Enterprise Security Development and Management

Enterprises security is a complex problem. Pure technology-driven development methods are not sufficient to solve a broad range of enterprise security issues. This paper analyzes the complexity of enterprise security and proposes an organization-driven approach for the problem. The approach combines a set of Unified Modeling Language-based approaches to bridge the gap between enterprise security architecture models and security application development models. It allows an enterprise to coordinate security resources from an enterprise point of view, and develop security applications systematically and efficiently. A comprehensive case study is conducted to illustrate the approach. The study shows through the refinement of enterprise security goals, both software goals and software requirements for a security application can be obtained. In particular, a security application is built to support the specification and automated verification of separation of duty access policies using the Object Constraint Language and formal method Alloy.
Numerical analysis of injection molding of glass fiber reinforced thermoplastics. Part 2: Fiber orientation

Numerical predictions of fiber orientation during injection molding of fiber-filled thermoplastics are compared to measurements. The numerical work successfully describes the flow of fiber-filled plastic during injection molding, using finite-difference solutions for the transport equations and marker particles to track the flow front. The flow is modeled as a 2-D, non-isothermal, free-surface flow with a new viscosity model dependent upon temperature, pressure, and fiber concentration. The fiber orientation is based upon solution to the Fokker-Planke equation. The comparison demonstrates fair agreement between predicted fiber orientation and experimental results for slow and fast injection speeds. For the slow speed case at 10 and 20 wt% fibers, the numerical and experimental works show that the fibers are more random at the flow front than at the centerline, and that the fibers become more aligned as they flow from the gate to the midstream region. At fast injection speeds, the agreement between the numerical and experimental works is not as good as at slow injection speed. Possible explanations for the discrepancies are that the flow is assumed to be simple shear when injection molding is known to be a pressure-driven flow, the fibers have an initial orientation for the runner rather than the assumed random orientation, the fibers that were displayed from the camera were more oriented just behind the flow front (owing to the fast injection speed), and the orientation requires more than a 2-D video image to represent a 3-D fiber orientation.