cssi/SciSciGPT-SciSciNet huggingface dataset:
Mechanism of Intracellular Block of the KcsA K+ Channel by Tetrabutylammonium: Insights from X-ray Crystallography, Electrophysiology and Replica-exchange Molecular Dynamics Simulations

The mechanism of intracellular blockade of the KcsA potassium channel by tetrabutylammonium (TBA) is investigated through functional, structural and computational studies. Using planar-membrane electrophysiological recordings, we characterize the binding kinetics as well as the dependence on the transmembrane voltage and the concentration of the blocker. It is found that the apparent affinity of the complex is significantly greater than that of any of the eukaryotic K(+) channels studied previously, and that the off-rate increases with the applied transmembrane voltage. In addition, we report a crystal structure of the KcsA-TBA complex at 2.9 A resolution, with TBA bound inside the large hydrophobic cavity located at the center of the channel, consistent with the results of previous functional and structural studies. Of particular interest is the observation that the presence of TBA has a negligible effect on the channel structure and on the position of the potassium ions occupying the selectivity filter. Inspection of the electron density corresponding to TBA suggests that the ligand may adopt more than one conformation in the complex, though the moderate resolution of the data precludes a definitive interpretation on the basis of the crystallographic refinement methods alone. To provide a rationale for these observations, we carry out an extensive conformational sampling of an atomic model of TBA bound in the central cavity of KcsA, using the Hamiltonian replica-exchange molecular dynamics simulation method. Comparison of the simulated and experimental density maps indicates that the latter does reflect at least two distinct binding orientations of TBA. The simulations show also that the relative population of these binding modes is dependent on the ion configuration occupying the selectivity filter, thus providing a clue to the nature of the voltage-dependence of the binding kinetics.
Influence of Hydration Temperature on Durability and Mechanical Property Performance of Prestressed and Precast High-Performance Concrete Beams:

Concrete technology has continued to advance throughout the years to meet the demands of designers and innovative structural systems. With the advent of high-performance concrete (HPC), which contains large amounts of cementitious materials, the investigation of the impact of concrete temperature development during hydration on concrete performance is of keen interest. Match-curing technology was used to investigate the influence of concrete temperature development during hydration on the mechanical and material property performance of prestressed and precast HPC beams. These members were fabricated for use in two recently constructed HPC bridges in Texas. The investigation was conducted in conjunction with the design, instrumentation, and construction of the Louetta Road Overpass in Houston, Texas, and the North Concho River US-87 and South Orient Railroad Overpass in San Angelo, Texas. FHWA and the Texas Department of Transportation cosponsored these projects as part of the Strategic Highway Research Pr...
Reviewing definitions of urinary continence in the contemporary spina bifida literature: a call for clarity.

Abstract Background Urinary continence is a common goal for children with spina bifida and their physicians. However, definitions of urinary continence vary widely across published studies. We systematically assessed the utilization of common definitions of urinary continence in the spina bifida literature. Methods We searched library databases for reports (2000–2012) describing urinary continence outcomes in children with spina bifida. We assessed various patient-level factors such as age, lesion level, surgical history, and use of additional therapies, as well as study-level factors such as study design, country of origin, continence definition(s), and method of data collection. Results Of 473 identified articles, 105 met inclusion criteria, comprising a total of 3209 patients. Of these, 1791 patients (56%) were deemed continent by the study authors. Only 60 studies (57%) clearly defined what they considered to be “continent”. The most common definition, used in 24% of all reports, was “always dry”. There was no association between journal of publication ( p = 0.13), publication year ( p = 0.86), study size ( p = 0.26), or study country ( p = 0.43) and likelihood of a continence definition being included in the manuscript. Conclusions The most frequent definition of urinary continence in the spina bifida literature is “always dry”. However, definitions were highly variable, and many authors did not define continence at all. Clinicians and researchers alike would be better able to apply research findings toward improving patient care if continence definitions were more explicitly reported and less variable.
Effects of sequence length and structure on implicit serial learning

Some data suggest that, as in explicit serial learning, longer sequences are more difficult to learn implicitly. These findings have been used to support the inference that implicit learning is capacity-limited. However, investigations of the effect of sequence length on implicit learning have confounded sequence structure with sequence length. These factors were manipulated independently in 3 experiments using a serial reaction time task. The results showed that sequence structure, not sequence length, largely determines the extent of sequence learning.
Advanced refractory metals and composites for extraterrestrial power systems

Concepts for future space power systems include nuclear and focused solar heat sources coupled to static and dynamic power-conversion devices; such systems must be designed for service lives as long as 30 years, despite service temperatures of the order of 1600 K. Materials are a critical technology-development factor in such aspects of these systems as reactor fuel containment, environmental protection, power management, and thermal management. Attention is given to the prospective performance of such refractory metals as Nb, W, and Mo alloys, W fiber-reinforced Nb-matrix composites, and HfC precipitate-strengthened W-Re alloys.
Interparticle influence on size/size distribution evolution of nanocrystals.

This report introduces a Monte Carlo simulation method to quantitatively deconvolute the size-dependent UV−vis absorption spectra of colloidal semiconductor nanocrystals. The method was experimentally verified and then applied for studying the transition stage from net dissolution to Ostwald ripening of CdS nanocrystals in a few nanometers size range quantitatively using the UV−vis spectra recorded in situ. Interparticle interaction in such processes was identified, which strongly affected the temporal evolution of the size and size distribution in a system. A preliminary model was proposed to quantitatively account for these observations by considering both solution−particle and particle−particle diffusion. The results indicate that crystallization processes of nanocrystals are substantially different from that of large-sized crystals.
Dual-Doppler Observation of a Tornadic Storm

Abstract On 20 April 1974 a tornadic storm passed between the two NSSL Doppler radars spaced about 42 km apart. Both radars simultaneously collected Doppler data throughout the storm. Air motions synthesized from these data provide the first three-dimensional display of Doppler-derived wind fields in a tornadic storm. Cyclonic circulation, associated with the tornado, and regions of intense up- and down-drafts are clearly evident.
Paper-and-pencil versus computer-administered MMPIs: A comparison of patient's attitudes

Abstract Attitudinal variables contributing to patients' perceptions of computer-administered MMPIs were examined in a heterogeneous clinical sample. One hundred and eighty-five subjects were randomly assigned to computer or paper-and-pencil administration conditions in which they received both the MMPI and an attitude survey. In general, the computer administered MMPI was perceived as more interesting and less anxiety-provoking than the paper-and-pencil MMPI. Subjects in the computer group felt more positively toward the examiner administering test instructions and felt that the test went more quickly. Subjects in the computer and paper-and-pencil groups did not differ regarding their concerns about privacy and the disposition of test results. Results suggest that cyberphobia does not characterize the general clinical population and that patients' attitudinal and affective responses to computerized versions of the MMPI may enhance the utility of this assessment procedure.
Identification and characterization of ten new water gaps in seeds and fruits with physical dormancy and classification of water-gap complexes.

Background and aims Physical dormancy (PY) occurs in seeds or fruits of 18 angiosperm families and is caused by a water-impermeable palisade cell layer(s) in seed or fruit coats. Prior to germination, the seed or fruit coat of species with PY must become permeable in order to imbibe water. Breaking of PY involves formation of a small opening(s) (water gap) in a morpho-anatomically specialized area in seeds or fruits known as the water-gap complex. Twelve different water-gap regions in seven families have previously been characterized. However, the water-gap regions had not been characterized in Cucurbitaceae; clade Cladrastis of Fabaceae; subfamilies Bombacoideae, Brownlowioideae and Bythnerioideae of Malvaceae; Nelumbonaceae; subfamily Sapindoideae of Sapindaceae; Rhamnaceae; or Surianaceae. The primary aims of this study were to identify and describe the water gaps of these taxa and to classify all the known water-gap regions based on their morpho-anatomical features. Methods Physical dormancy in 15 species was broken by exposing seeds or fruits to wet or dry heat under laboratory conditions. Water-gap regions of fruits and seeds were identified and characterized by use of microtome sectioning, light microscopy, scanning electron microscopy, dye tracking and blocking experiments. Key results Ten new water-gap regions were identified in seven different families, and two previously hypothesized regions were confirmed. Water-gap complexes consist of (1) an opening that forms after PY is broken; (2) a specialized structure that occludes the gap; and (3) associated specialized tissues. In some species, more than one opening is involved in the initial imbibition of water. Conclusions Based on morpho-anatomical features, three basic water-gap complexes (Types-I, -II and -III) were identified in species with PY in 16 families. Depending on the number of openings involved in initial imbibition, the water-gap complexes were sub-divided into simple and compound. The proposed classification system enables understanding of the relationships between the water-gap complexes of taxonomically unrelated species with PY.
Cigarette smoke inhibits endometrial epithelial cell proliferation through a nitric oxide-mediated pathway.

Objective To determine the direct effects of cigarette smoke (CS) on human endometrial surface epithelial cell line proliferation. Design In vitro study using HES cells and primary human endometrial cells. Setting University-based academic center. Patient(s) Premenopausal women in the proliferative phase of the cycle. Intervention(s) The HES cells and primary human endometrial cells were exposed to cigarette smoke–saturated solution. Main Outcome Measure(s) Cell proliferation and expression of different isoforms of nitric oxide synthase. Result(s) Cigarette smoke inhibited HES cell proliferation in a dose- and time-dependant manner. The inhibitory effect of CS was blocked by hemoglobin and enhanced by L-arginine (L-Arg). Cigarette smoking and nicotine stimulated the expression of endothelial NO synthase (eNOS) and inducible NO synthase (iNOS) whereas benzo[a]pyrene (BP) only stimulated the expression of eNOS in HES cells. Cigarette smoke stimulated the expression of eNOS/iNOS in primary human endometrial cells, comprised of epithelial and stromal cells. The effect of CS on eNOS/iNOS expression in HES cells was blocked by ascorbic acid but not by glutathione. Conclusion(s) Cigarette smoke inhibits endometrial cell proliferation through a nitric oxide–mediated pathway.
Segmentation of multiband imagery using minimum spanning trees

We present a new technique for the automatic segmentation of multiband imagery. Our approach is based on the computation of a minimum spanning tree over a graph derived from the image. We use a fast graph-search algorithm and a custom tree-splitting algorithm to provide a high level of performance. This approach captures some of the gestalt characteristics of human perceptual grouping and is easily adaptable to a variety of spectral and spatial criteria. We demonstrate our technique on multispectral and hyperspectral imagery of the earth's surface.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Environmental temperature and the body fluid system of the fresh-water teleost—IV. Water-electrolyte regulation in thermally acclimated carp, Cyprinus carpio☆

Abstract 1. 1. Carp have marked ability to regulate body fluid electrolytes over a wide range of temperatures. 2. 2. There was a seasonal variation in plasma ions; factors other than ions, amino acids or protein may be involved in cold-acclimated animals. 3. 3. The muscle water content was thermostable. 4. 4. The concentration of Cl−, Ca2+ and Mg2+ were relatively stable, while Na+ and K+ varied seasonally and with temperature. 5. 5. Electrolyte changes which occur during temperature acclimation may contribute to accompanying alterations in intermediary metabolism.
Nonrandom Distribution of N-myc Oncogene Genotypes in Neuroblastoma

The distributions of Pvu II and Sph I alleles of the N-myc oncogene (also known as MYCN) were studied in a series of normal individuals and pediatric patients with solid tumors. In the case of Pvu II, where the polymorphic site is located 3' of the gene, the frequencies of the allele were 0.27 (11-kilobase fragment) and 0.73 (8-kilobase fragment) in 43 unrelated normal Caucasians. The frequencies of the allele were similar in 40 non-N-myc-amplified neuroblastomas, 47 Wilms' tumors, and 31 other pediatric tumors. In these cases, the genotypes were in Hardy-Weinberg equilibrium. In 18 N-myc-amplified neuroblastomas, however, the observed genotype frequencies deviated from Hardy-Weinberg equilibrium (P less than .005). Similar observations were made with an Sph I restriction fragment length polymorphism where the polymorphic site is located in intron 2. The differences between amplified and nonamplified neuroblastomas suggest a possible involvement of sequences at or near N-myc in the progression of tumors where the N-myc gene is amplified.
Oxygen Respirometry to Assess Stability and Maturity of Composted Municipal Solid Waste

The stability and maturity of compost prepared from municipal solid waste (MSW) at a full-scale composting plant was assessed through chemical, physical, and biological assays. Respiration bioassays used to determine stability (O{sub 2} and CO{sub 2} respirometry) were sensitive to process control problems at the composting plant and indicated increasing stability with time. Radish (Raphanus sativus L.) and ryegrass (Lolium perenne L.) growth bioassays revealed that immature compost samples inhibited growth. Growth of ryegrass in potting mix prepared with cured compost not amended with fertilizer was enhanced as compared to a pest control. Garden cress (Lepidium sativum L.) seed germination, used as an indicator of phytotoxicity, revealed inhibition of germination at all compost maturity levels. The phytotoxicity was though to be salt-related. Spearman rank-order correlations demonstrated that O{sub 2} respirometry, water-soluble organic C, and the water extract organic C to organic N ratio, significantly correlated with compost age and best indicated an acceptable level of stability. Oxygen respirometry also best predicted the potential for ryegrass growth, and an acceptable level of compost maturity. 31 refs., 4 figs., 5 tabs.
Toward a widely tunable narrow linewidth RF source through heterogenous silicon photonic integration

By mixing two lasers together it, is possible to generate RF signals from near DC to hundreds of GHz. Through the use of a narrow-linewidth low-frequency oscillator, optical modulator, and injection locking, much higher frequency outputs can be produced that still retain the narrow linewidth of the low frequency oscillator. Here we focus on the design and implementation of an integrated device including photonic sources and modulators to realize the system described above. Specifically, we report on the creation and mixing of two tunable lasers on a silicon platform with a heterogeneously integrated gain medium realized in a III-V material system.
Sexually dimorphic expression of multiple doublesex-related genes in the embryonic mouse gonad.

Abstract The only molecular similarity shown so far for sexual regulatory genes among different phyla involves doublesex (dsx) of Drosophila, mab-3 and mab-23 of Caenorhabditis elegans, and Dmrt1 of vertebrates. These genes encode DM domain transcription factors (DM=dsx and mab-3) and are required for sexual differentiation. In the case of dsx and mab-3, the two genes control analogous aspects of sexual development, bind similar DNA sequences, and are capable of functional substitution in vivo. All three phyla have multiple DM domain genes, but it is unknown how many of these are involved in sexual development. Mammals, for example, have at least seven DM domain genes, but embryonic expression has only been examined in detail for Dmrt1(dsx- and mab-3 related transcription factor 1). We have identified additional murine DM domain genes and have examined their expression in the mouse embryo, with emphasis on the developing gonad. At least three murine DM domain genes in addition to Dmrt1 are expressed in the embryonic gonad: Dmrt4 is expressed at similar levels in gonads of both sexes; Dmrt3 is more highly expressed in males; and Dmrt7 is more highly expressed in females. Expression of three other genes is low or absent in the embryonic gonad. Two of these, Dmrt5 and Dmrt6, are expressed primarily in the brain, and the third, Dmrt2, is expressed in presomitic mesoderm and developing somites. Our data suggest that multiple DM domain genes may be involved in mammalian sexual development, and that they may function in both testis and ovary development.
Short communication: inhibiting biofilm formation on paper towels through the use of selenium nanoparticles coatings

Bacterial infections are commonly found on paper towels and other paper products, leading to the potential spread of bacteria and consequent health concerns. The objective of this in vitro study was to introduce antibacterial properties to standard paper towel surfaces by coating them with selenium nanoparticles. Scanning electron microscopy was used to measure the size and distribution of the selenium coatings on the paper towels. Atomic force microscopy was used to measure the surface roughness of paper towels before and after they were coated with selenium nanoparticles. The amount of selenium precipitated on the paper towels was measured by atomic absorption spectroscopy. In vitro bacterial studies with Staphylococcus aureus were conducted to assess the effectiveness of the selenium coating at inhibiting bacterial growth. Results showed that the selenium nanoparticles coated on the paper towel surface were well distributed with semispherical geometries about 50 nm in diameter. Most importantly, the selenium nanoparticle-coated paper towels inhibited S. aureus growth by 90% after 24 and 72 hours compared with the uncoated paper towels. Thus, the study showed that nanoparticle selenium-coated paper towels may lead to an increased eradication of bacteria in a wider range of clinical environments and in the food industry, thus improving human health.
An Integrative Literature Review of Study Abroad Programs for Nursing Students

Abstract Nurse researchers need to explore study abroad programs and identify their impact on the development of cultural competence and global perspectives in nursing students. Despite the anecdotal professional and personal benefits that have been attributed to study abroad in other disciplines, current nursing literature regarding this topic is limited and has only emerged in nursing research within the last decade. There is a significant gap in the existing body of knowledge with respect to American nursing students who study abroad and the reported benefits of and impediments to their experiences. Much of the nursing research conducted with American nursing students has been quantitative as opposed to qualitative studies with European and Australian nursing students. Many samples are homogenous and therefore exclude diverse populations. Further research involving all methodological designs is warranted to better understand this type of engaged learning.
Utterance-based systems: organization and design of AAC interfaces

Augmented and Alternative Communication (AAC) interfaces present many unique design challenges due to the wide variation of physical ability among AAC users. The development of technological aids for AAC users to bridge the communication gap, increase both rate and comprehensiveness of communication [1]. Here we focus on the design of an utterance-based system developed for literate, high-functioning adults interacting in public situations. This research involves the design and development of a coherent and intuitive AAC interface for an utterance-based system built upon theoretical evidence and observation of commercial-grade AAC interface software.
Application of californium-252 plasma desorption mass spectroscopy to chlorophyll studies☆

Applications of 252Cf-PDMS to a variety of chlorophyll problems are described. This form of heavy particle induced desorption mass spectroscopy is highly suitable to the mass measurement of nonvolatile, thermally unstable chlorophylIs and chlorophyll derivatives. 252Cf-PDMS has been applied to the characterization of the products of the classical chlorophyll allomerization reaction, and to the synthesis of linked chlorophyll special pairs designed to mimic the in vivo P700 photoreaction center. The applications of 252Cf-PDMS to the characterization of chlorophyll aggregates and to the examination of the redox properties of the chlorophylls are also described.
Conditioning, Expectation, and Desire for Relief in Placebo Analgesia

The factors that contribute to the magnitude of placebo analgesia have, until recently, been elusive. This review explores the roles of external factors, such as conditioning, and experienced factors, such as expectation and desire for pain reduction, in placebo analgesia. Placebo analgesia effects have been found to reflect decreases in pain beyond that accounted for by the natural history of a pain condition. These effects clearly are influenced by the effectiveness of previous active treatments (ie, conditioning) as well as by environmental factors that provide cues/suggestions for analgesia. However, external factors are effective insofar as they provide expectations for pain reduction and a lowering of desire for relief. Experienced factors, such as expectation and desire for relief, also are integral dimensions of some human emotional states, such as anxiety. We present an explanation of placebo analgesia that suggests that it is the result of mechanisms that also regulate emotional states.
Rechargeable high voltage low temperature molten, salt cell Na/β''-alumina/SCl3+ in AlCl3-NaCl

This paper deals with the rechargeable molten salt cell: Na/β''-alumina/SCl3+ in AlCl3-NaCl, and its underlying chemistry. This cell is operated at 180–250°C, and is characterized by two discharge plateaus: 4Na + SC13AlCl4 + 3AlCl3 = S + 4NaAlCl4 2Na + S + AlCl3 = AlSCl + 2NaCl The AlCl3-NaCl melt is important in stabilizing several sulfur species formed in charge/discharge processes and in maintaining a conducting liquid positive mixture. The cell voltage in the fully charged state is ⪢=4.30 V for the first step and 2.75 V for the second step. The theoretical capacity is in excess of 190 Ah kg−1 , corresponding to a theoretical energy density in excess of 700 Wh kg−1. High energy and power densities have been achieved. Hundreds of deep charge/discharge cycles have been obtained for several cells using Reticulated Vitreous Carbon or tungsten positive current-collectors.
An Improved Prediction Method for Noise Generated by Conventional Profile Coaxial Jets

A semiempirical model for predicting the noise generated by conventional velocity profile jets exhausting from coaxial nozzles is presented and compared with small scale static and simulated flight data. Improvements to the basic circular jet noise prediction are developed which improve the accuracy, especially at high jet velocity and near the jet axis.
In situ observations of the gasification of carbon catalyzed by calcium oxide

Abstract An environmental cell in a transmission electron microscope has been used to examine the gasification of graphite in the presence of calcium oxide formed by hydrolysis and thermal decomposition of calcium nitrate dispersed on the sample. No reaction was observed on exposure to water vapor at 500°C. However, after 90 min of such exposure the environment was changed to a hydrogen-nitrogen mixture and the catalyzed reaction then proceeded according to a “channeling” mode.
The third transmembrane domain of the serotonin transporter contains residues associated with substrate and cocaine binding

Twenty residues in the third transmembrane domain of the serotonin transporter (SERT) were mutated, one at a time, to cysteine. Almost all of these mutants were fully active for serotonin (5-HT) transport and insensitive to inactivation by the positively charged cysteine reagent [2-(trimethylammonium)ethyl]methanethiosul-fonate (MTSET). Two active mutants, I172C and I179C, were sensitive to rapid inactivation by MTSET but were relatively insensitive to the negatively charged reagent (2-sulfonatoethyl)methanethiosulfonate (MTSES). Inactivation of I172C was blocked by 5-HT and cocaine, but I179C was not similarly protected. Replacement of Tyr-175 with cysteine resulted in a mutant with low transport activity, and, at the neighboring Tyr-176, cysteine replacement completely blocked transport. The Y175C and Y176C mutants were expressed on the cell surface at levels 84% and 69%, respectively, that of wild type (C109A) SERT. Mutants Y175C and Y176C had lower cocaine affinity than C109A, as measured by displacement of the high affinity cocaine analog 2beta-carbomethoxy-3beta-(4-[125I]iodophenyl)tropane (beta-CIT). For Y176C, 5-HT affinity also was decreased. MTSET inactivated beta-CIT binding to I172C and Y176C, but only slightly inhibited binding to I179C and C109A. The MTSET sensitivity of cysteine replacements at positions 172, 176, and 179 was not observed when these positions were replaced with alanine, serine, or methionine. The results suggest that Ile-172, Tyr-176 and Ile-179 are on one face of an alpha-helical transmembrane element, and that Ile-172 and Tyr-176 are in proximity to the binding site for 5-HT and cocaine.
Intramolecular hydrogen bonding and calixarene-like structures in p-cresol/formaldehyde resins

Abstract The nature of the strong hydrogen bonds found in p-cresol/formaldehyde (PCF) resins, compared to ordinary phenolic compounds, is studied. The evidence from FTIR spectroscopy indicates that this strong interaction is due to intramolecular hydrogen bonding from “calixarene-like” structures. The formation of this structure in PCF is enabled by its “linear” (all-ortho-linkage) structure, which is not present in branched resins. Additionally, a transition is observed at around 175 to 200°C where the intramolecular hydrogen bonded structure is lost. This structure cannot be recovered upon cooling or annealing due to restrictions on conformational rotations that are coupled to a new pattern of intermolecular hydrogen bonding. However, the structure is reformed by dissolving the resin in solution and casting new films.
Distribution of lunar craters according to morphology from Ranger VIII and IX PHOTOGRAPHS.

Morphology of lunar craters from Ranger photographs, noting distribution and possible competing processes of crater formation and destruction
Impact of Acquisitions on Thrift Performance

This study focuses on the risk and return performance of savings and loans that were active acquirers during the early and mid-eighties relative to that of non-acquirers. Acquirers took on more risks than nonacquirers, but were less profitable. Separating acquirers by the health of their acquisitions, acquirers of both healthy and troubled associations or of troubled associations only were more highly leveraged and saw their profitability erode over the post-acquisition period. These results suggest that the problems of integration are compounded when there are multiple acquisitions over a relatively short period of time and when the acquired association is unhealthy.
The electronic structures of urazole, pyrrole, and their ions. The σ-π separability problem

Ab initio all-electron LCGTO-SCF-MO calculations have been made on the 5-membered ring nitrogen heterocycles urazole (C2H3N3O2), pyrrole (C4H5N), and their ion radicals. Wavefunctions were obtained, population analyses made, and electron density contour maps drawn. The results show that for urazole considerable polarity develops in the σ bonds as a result of a large shift of σ charge towards the nitrogen atoms at the expense of the carbon and hydrogen atom σ-electrons with only little effect on the oxygen atom σ charges. In addition, it is concluded that the π-electron approximation should be used with great caution for this type of molecule since the σ-π separability conditions are not well satisfied.
DCEMRI of breast lesions: is kinetic analysis equally effective for both mass and nonmass-like enhancement?

To perform a pilot study investigating whether the sensitivity and specificity of kinetic parameters can be improved by considering mass and nonmass breast lesions separately. The contrast media uptake and washout kinetics in benign and malignant breast lesions were analyzed using an empirical mathematical model (EMM), and model parameters were compared in lesions with mass-like and nonmass-like enhancement characteristics. 34 benign and 78 malignant breast lesions were selected for review. Dynamic MR protocol: 1 pre and 5 postcontrast images acquired in the coronal plane using a 3D T1-weighted SPGR with 68 s timing resolution. An experienced radiologist classified the type of enhancement as mass, nonmass, or focus, according to the BI-RADS lexicon. The kinetic curve obtained from a radiologist-drawn region within the lesion was analyzed quantitatively using a three parameter EMM. Several kinetic parameters were then derived from the EMM parameters: the initial slope (Slope(ini)), curvature at the peak (kappa(peak)), time to peak (T(peak)), initial area under the curve at 30 s (iAUC30), and the signal enhancement ratio (SER). The BI-RADS classification of the lesions yielded: 70 mass lesions, 38 nonmass, 4 focus. For mass lesions, the contrast uptake rate (alpha), contrast washout rate (beta), iAUC30, SER, Slope(ini), T(peak) and kappa(peak) differed substantially between benign and malignant lesions, and after correcting for multiple tests of significance SER and T(peak) demonstrated significance (p 0.5). Kinetic parameters could distinguish benign and malignant mass lesions effectively, but were not quite as useful in discriminating benign from malignant nonmass lesions. If the results of this pilot study are validated in a larger trial, we expect that to maximize diagnostic utility, it will be better to classify lesion morphology as mass or nonmass-like enhancement prior to kinetic analysis.
Effects of high occupancy vehicle lanes on freeway congestion

Abstract Previous research on the effect of HOV (high occupancy vehicle) lanes on bottleneck flows is extended here to entire freeways using both theory and empirical evidence. The paper shows that if the flows of both high- and low-occupancy vehicles remain invariant before and after a freeway lane is converted to HOV use, then the freeway’s overall traffic density upstream of its bottlenecks is reduced – albeit less than expected – if the HOV lane is underutilized. As a result, HOV lanes can extend queues over longer distances. These expansions can be problematic if the queues’ expanded portions impede traffic on heavily traveled routes that do not pass through the bottleneck. To quantify this effect, the paper analyzes HOV lanes on long, multi-ramp freeways. Formulae are given for the changes in people-hours and vehicle-hours of travel induced by an HOV lane, both when there is uncongested freeway space upstream of the queue to accommodate its expansion, and when there is not. All the inputs to these formulae are either observable or easy to estimate. Hence, the recipes can help evaluate any freeway’s existing, or planned, HOV lane installation. The HOV lanes at all the sites we have analyzed, which are quite typical, add less than 2% to vehicular delay and reduce people delay by more than 10%. These estimates assume no increase in car-pooling. More generally, the paper also suggests how to deploy HOV lanes on city-wide freeway systems and recommends steps to better plan city-wide systems of bus lanes.
Patterns of bisphosphonates utilization in patients under age 45 in a large cohort of commercial insurance beneficiaries in the United States.

Background The effectiveness and safety of bisphosphonates treatment used in the young population have not been well studied. Despite insufficient data on effectiveness and safety of bisphosphonates in young patients, bisphosphonates are still considered in younger patients at high risk for osteoporosis or fracture. The objectives of this study were to identify bisphosphonate initiators aged 10–45 years and describe their clinical characteristics and to assess time trends of bisphosphonate use over the past decade in a large U.S. population-based cohort.
Alternative splicing of HLA-DQB transcripts and secretion of HLA-DQ beta-chain proteins: allelic polymorphism in splicing and polyadenylylation sites

HLA class II antigens are highly polymorphic cell-surface proteins involved in initiation and regulation of the immune response. Allelic sequence variation primarily affects the structure of the first external domains of alpha and beta component chains. Here we provide evidence for other types of allelic polymorphism for the genes encoding these chains. Sequences of two cDNA clones corresponding to HLA-DQB mRNAs from an HLA-homozygous cell line exhibit both alternative splicing and read-through of polyadenylylation. Furthermore, alternative splicing that deletes the transmembrane exon is associated with only a subset of HLA-DQB alleles, while the polyadenylylation-site read-through is found in a larger subset. This suggest that polymorphic cis-acting elements within the HLA-DQB gene control both processing steps. Proteins, presumably encoded by alternatively spliced mRNAs lacking transmembrane exons, are immunoprecipitated with a monomorphic monoclonal antibody directed against HLA-DQ. These proteins are found in supernatants of cultured cell lines for which secretion is predicted, but not in those of cell lines that do not contain alternatively spliced mRNAs.
An estimated cost of lost climate regulation services caused by thawing of the Arctic cryosphere

Recent and expected changes in Arctic sea ice cover, snow cover, and methane emissions from permafrost thaw are likely to result in large positive feedbacks to climate warming. There is little recognition of the significant loss in economic value that the disappearance of Arctic sea ice, snow, and permafrost will impose on humans. Here, we examine how sea ice and snow cover, as well as methane emissions due to changes in permafrost, may potentially change in the future, to year 2100, and how these changes may feed back to influence the climate. Between 2010 and 2100, the annual costs from the extra warming due to a decline in albedo related to losses of sea ice and snow, plus each year's methane emissions, cumulate to a present value cost to society ranging from US$7.5 trillion to US$91.3 trillion. The estimated range reflects uncertainty associated with (1) the extent of warming-driven positive climate feedbacks from the thawing cryosphere and (2) the expected economic damages per metric ton of CO2 equivalents that will be imposed by added warming, which depend, especially, on the choice of discount rate. The economic uncertainty is much larger than the uncertainty in possible future feedback effects. Nonetheless, the frozen Arctic provides immense services to all nations by cooling the earth's temperature: the cryosphere is an air conditioner for the planet. As the Arctic thaws, this critical, climate-stabilizing ecosystem service is being lost. This paper provides a first attempt to monetize the cost of some of those lost services.
Suspension Plasma Spraying of Intermediate Temperature SOFC Components Using an Axial Injection DC Torch

Intermediate temperature SOFC components, such as dense, nanostructured SDC electrolytes (samarium doped ceria) and porous anode sublayers were fabricated by suspension plasma spraying using an axial feed dc plasma torch. The liquid carrier employed in this approach allowed for controlled injection of much finer particles than in conventional thermal spraying, leading to thin coatings with a refined microstructure. Dense, thin (
Teachers' reports of student misbehavior in physical education

Classroom management, and, more specifically, the management of student behavior, is an essential skill for and central concern of physical education teachers. Surprisingly little information is known, however, about the specific nature of student behaviors that might negatively affect the class environment. The purpose of this study was to examine teachers' reports of student behaviors that may create management issues in physical education classes. Over 300 teachers representing a range of grade levels and school contexts completed a survey related to the frequency of potentially negative student behaviors. Many types of misbehaviors were reported, but the most common were mild. Teachers' reports varied by sex, years of teaching experience, and school context.
The synthesis of low temperature phases by the CO-condensation of the elements: A new superconducting A15 compound, V3Al

Abstract A method is described whereby intermetallic phases which are not stable at high temperatures may be formed using controlled vacuum evaporation of the elements. V 3 Al with the A15 structure was formed on substrates held at temperatures in the range 350–450°C. For the as-deposited sample the lattice parameter was 0.483 nm and the superconducting critical temperature was 9.6°K.
Localization in interstitial dosimetry utilizing the CT scanner

Abstract A simple method utilizing CT scanners which were readily available is described in which alignment of the isodose curves can be made directly on the printout of the CT scan. This has obvious practical and theoretical advantages. In particular, the dose to vital structures, such as spinal cord and other critical viscera. can be well described.
Alarm calls of Belding's ground squirrels to aerial predators: nepotism or self-preservation?

Belding's ground squirrels (Spermophilus beldingi) give acoustically distinct alarm calls to aerial and terrestrial predators. The animals typically give multiple-note trills to predatory mammals, and single-note whistles to flying hawks. During a 9-year study of free-living S. beldingi at Tioga Pass, California, the adaptive significance of the whistle call was investigated. Data were gathered on 664 ground squirrel-hawk interactions, most of which were induced by flying trained raptors over individually marked study animals of known sex and age. The sight of a flying hawk and the sound of whistles stimulated widespread calling and running to shelter by the ground squirrels (Fig. 1). Wild raptors were rarely successful at capturing the rodents once a whistle had been given, and fewer callers than noncallers were killed (Table 1). Individuals of both sexes and all ages whistled equally often (Fig. 4), and females' tendencies to whistle were not affected by the presence of relatives, including offspring (Fig. 5). The most frequent callers were animals in exposed positions: far from cover and close to the predatory bird (Table 2). Taken together the data suggest that unlike trills, which increase vulnerability to terrestrial predators (Table 1) and function to warn relatives, whistle directly benefit callers by increasing their chances of escaping from hawks.
Bioassay for siderophore utilization by Candida albicans

A convenient plate assay which is sensitive to medium pH has been developed to evaluate potential siderophores of Candida albicans. Adding a siderophore to a filter paper disk on chemically defined Lee's agar (final pH 7.2) seeded with the test strain reversed the growth inhibitory effects of the supplemented (25-100 micrograms/ml) iron chelator ethylenediaminedi(o-hydroxyphenylacetic acid), to provide a zone of growth stimulation. This bioassay has been used to demonstrate the structure-activity relationships of ferrichrome and several water-soluble hydroxamate peptide building blocks of this natural siderophore. Of all compounds so evaluated, ferrichrome exhibited the best activity.
Salmonella Organisms on and in Chicken Eggs

Abstract THE purpose of this investigation was to obtain information concerning the part played by shell eggs in contributing to the contamination of egg powder with organisms of the genus Salmonella. The common occurrence of Salmonella types other than S. pullorum and S. gallinarum in the meats of chicken eggs has not been conclusively established, although Watt (1945) reported the isolation of S. Montevideo. We are not aware that other types have been isolated from meats of naturally infected chicken eggs in this country. On the other hand, current literature records well over 50 types isolated from spray dried whole egg powder manufactured in the United States (Gibbons and Moore, 1944; Schneider, 1946; Haines, Elliot and Tomlinson, 1947; Solowey et al., 1947). Current literature also reveals that nine of the types found in egg powder, in addition to S. pullorum, have been isolated from shells of chicken eggs within the last three . . .
Spectral albedos of mid-latitude snowpacks

Spectral albedos of impure-nonhomogeneous snowpacks, typical of midlatitudes, from 400 to 2200 nm were modeled through a numerical solution of the radiative transfer equation in the two-stream approximation. Discrete depth-dependent values of density, grain size and impurity concentration were used to characterize the snowpacks. The model is for diffuse incident radiation, and the numerical method is based on doubling and invariant imbedding. The effect of soot impurities on snowpack albedos is illustrated when a snowpack is several centimeters deep and soot reduces the albedos at visible wavelengths, however, when a snowpack is only a few centimeters deep, soot may increase the albedos at visible wavelengths. By adjusting soot content and snow grain size, good quantitative agreement with some observations at the Cascade Mountains (Washington) and at Point Barrow (Alaska) are obtained; however, the model grain sizes are found to be fifty to four hundred percent larger than the measured values. For satellite snowcover observations, a model for effective albedo of partially snow-covered areas was developed and compared with some NOAA-2 observations of the southeastern United States.
Self generated attitude change a person by situation analysis of attitude polarization and attenuation

Abstract The potential moderating effects of differences in the need for cognition on the attitude polarization process were explored. Based on putative schematabased differences in information processing, it was predicted that an increased opportunity for thought would result in (a) more attitude polarization for low need for cognition persons than for high need for cognition persons and (b) more attitude attenuation for high need for cognition persons than for low need for cognition persons. Participants completed the Need for Cognition scale and were given either little or ample time to think about issues toward which they previously held moderate attitudes. Attitudes were reassessed following thought about the issues. The results were consistent with the predicted moderating effects of individual differences in the need for cognition on thought-induced attitude polarization. Implications of and alternative explanations for the findings are discussed.
Differential modulation of auditory thalamocortical and intracortical synaptic transmission by cholinergic agonist.

Abstract To investigate synaptic mechanisms underlying information processing in auditory cortex, we examined cholinergic modulation of synaptic transmission in a novel slice preparation containing thalamocortical and intracortical inputs to mouse auditory cortex. Extracellular and intracellular recordings were made in cortical layer IV while alternately stimulating thalamocortical afferents (via medial geniculate or downstream subcortical stimulation) and intracortical afferents. Either subcortical or intracortical stimulation elicited a fast, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX)-sensitive, monosynaptic EPSP followed by long-duration, polysynaptic activity. The cholinergic agonist carbachol suppressed each of the synaptic potentials to different degrees. At low concentrations (5 μM) carbachol strongly reduced (>60%) the polysynaptic slow potentials for both pathways but did not affect the monosynaptic fast potentials. At higher doses (10–50 μM), carbachol also reduced the fast potentials, but reduced the intracortically-elicited fast potential significantly more than the thalamocortically-elicited fast potential, which at times was actually enhanced. Atropine (0.5 μM) blocked the effects of carbachol, indicating muscarinic receptor involvement. We conclude that muscarinic modulation can strongly suppress intracortical synaptic activity while exerting less suppression, or actually enhancing, thalamocortical inputs. Such differential actions imply that auditory information processing may favor sensory information relayed through the thalamus over ongoing cortical activity during periods of increased acetylcholine (ACh) release.
X-ray diffraction data for graphite to 20 GPa.

X-ray diffraction data have been obtained on polycrystalline graphite at pressures up to 20 GPa. A phase transition is observed at \ensuremath{\sim}11 GPa, as evidenced by softening in the interlayer spacing and the observation of new diffraction lines. Below this pressure the variation of the lattice parameters a and c are compared with elastic stiffnesses obtained from ultrasonic measurements. A new value for ${C}_{13}$ is proposed. The variation c(P) is compared to the recently proposed universal isotherm equation.
The sufficiency of target costing for evaluating production-related decisions

Abstract Target costing is a cost management system designed to develop products with a level of profitability deemed adequate to justify their production. This paper examines whether production-related decisions made with target costing consistently add economic value to the firm. A traditional target costing model is compared to one that incorporates the cost of capital. An analysis of the two models reveals that the traditional target costing model systematically underestimates the marginal cost of invested funds and overestimates the marginal cost of cash-related production resources. A numerical example and graphical analysis demonstrate that a traditional target costing model can lead to accepting products that have a negative net present value, while rejecting products that have a positive net present value. Mathematical analysis of a traditional target costing model indicates that it is a systemic property of the model.