cssi/SciSciGPT-SciSciNet huggingface dataset:
The Precalculus Concept Assessment: A Tool for Assessing Students’ Reasoning Abilities and Understandings

This article describes the development of the Precalculus Concept Assessment (PCA) instrument, a 25-item multiple-choice exam. The reasoning abilities and understandings central to precalculus and foundational for beginning calculus were identified and characterized in a series of research studies and are articulated in the PCA Taxonomy. These include a strong understanding of ideas of rate of change and function, a process view of function, and the ability to use covariational reasoning to examine and represent how two covarying quantities change together. This taxonomy guided the PCA development and now provides the theoretical basis for interpreting and reporting PCA results. A critical element of PCA's design was to identify the constructs essential for learning calculus and to employ methods to assure that PCA items are effective in assessing these constructs. We illustrate the role that cognitive research played during both the design and validation phases of the PCA instrument. We also describe our...
Don't Try This at Home: Exotic Native and Nonnative Species in Our Backyard

“A 600-pound tiger will do what it wants, when it wants.” Tippi Hedren (Kelly, 2002) The exotic animal trade is alive and well in the United States and around the world. Exotic animals enter and ex...
Simultaneously Collected Monopolar and Discrete Bipolar Electrograms: Comparison of Activation Time Detection Algorithms

Designation of the time of local activation is fundamental to electrophysiological mapping. In normal myocardium, the minimum slope in extracellular monopolar (MP) electrograms has been linked through simultaneous intracellular and extracellular recordings to phase 0 of the action potential. However, no similar correlation has been demonstrated for a parameter from bipolar (BP) electrograms, now commonly used during electrophysiological studies and intraoperative mapping. The purpose of this work is to compare the activation time, determined according to several common algorithms applied to BP electrograms, with the time of the minimum slope in MP electrograms. Simultaneous normal epicardial MP and BP electrograms were acquired from subjects undergoing surgery for Wolf-Parkinson-White Syndrome and from dogs. The activation time in BP electrograms was defined by four algorithms: (1) peak (P); (2) greatest absolute slope (S); (3) zero crossing of the segment containing the greatest slope (FZC); and (4) morphological (M). Each was compared to the time of the minimum slope in the simultaneously recorded MP response. The incidence of outliers was tabulated. The distribution of activation times computed using each BP algorithm was statistically different from the distribution of activation times derived from MP electrograms. M performed best (absolute difference: 2.6 +/- 2.9 msec; cor coef: 0.9925 in man). The M, P, FZC, and S algorithms produced 3.2%, 3.5%, 4.7% and 4.7% outliers, respectively. The overall performance of a morphologically based algorithm is superior to simplistic BP algorithms based only on slope or peak.(ABSTRACT TRUNCATED AT 250 WORDS)
Optical properties of anisotropic core-shell pyramidal particles.

This paper describes an approach to fabricate anisotropic core−shell particles by assembling dielectric beads within fabricated noble metal pyramidal structures. Particles with gold (Au) shells and different dielectric cores were generated, and their optical properties were characterized by single particle spectroscopy. Because of their unique geometry, these particles exhibit multiple plasmon resonances from visible to near-IR wavelengths.
The load dependence of rate constants.

As experimental techniques in biophysics have progressed at the single molecule level, there has been considerable interest in understanding how external mechanical influences (such as load) affect chemical reactions. The majority of biophysical studies investigating load-dependent kinetics use an equation where the rate constant exponentially depends on force, which is sometimes called Bell’s equation. This equation requires the determination of two parameters that describe the potential energy-strain function: k0, which is the reaction rate in the absence of load, and xc, which is the difference in strain between the reactant and transition states. However, there have been theoretical studies based on Kramers’ theory suggesting that the rate constant should have load-dependent pre-exponential terms and nonlinear load-dependent terms in the exponential. Kramers’ theory requires an exact knowledge of the potential energy-strain function, which is in general not known for an experimental system. Here, we d...
Photosynthetic sunfleck utilization potential of understory saplings growing under elevated CO2 in FACE.

Few studies have evaluated elevated CO2 responses of trees in variable light despite its prevalence in forest understories and its potential importance for sapling survival. We studied two shade-tolerant species (Acer rubrum, Cornus florida) and two shade-intolerant species (Liquidambar styraciflua, Liriodendron tulipifera) growing in the understory of a Pinus taeda plantation under ambient and ambient+200 ppm CO2 in a free air carbon enrichment (FACE) experiment. Photosynthetic and stomatal responses to artificial changes in light intensity were measured on saplings to determine rates of induction gain under saturating light and induction loss under shade. We expected that growth in elevated CO2 would alter photosynthetic responses to variable light in these understory saplings. The results showed that elevated CO2 caused the expected enhancement in steady-state photosynthesis in both high and low light, but did not affect overall stomatal conductance or rates of induction gain in the four species. Induction loss after relatively short shade periods (<6 min) was slower in trees grown in elevated CO2 than in trees grown in ambient CO2 despite similar decreases in stomatal conductance. As a result leaves grown in elevated CO2 that maintained induction well in shade had higher carbon gain during subsequent light flecks than was expected from steady-state light response measurements. Thus, when frequent sunflecks maintain stomatal conductance and photosynthetic induction during the day, enhancements of long-term carbon gain by elevated CO2 could be underestimated by steady-state photosynthetic measures. With respect to species differences, both a tolerant, A. rubrum, and an intolerant species, L. tulipifera, showed rapid induction gain, but A. rubrum also lost induction rapidly (c. 12 min) in shade. These results, as well as those from independent studies in the literature, show that induction dynamics are not closely related to species shade tolerance. Therefore, it cannot be concluded that shade-tolerant species necessarily induce faster in the variable light conditions common in understories. Although our study is the first to examine dynamic photosynthetic responses to variable light in contrasting species in elevated CO2, studies on ecologically diverse species will be required to establish whether shade-tolerant and -intolerant species show different photosynthetic responses in elevated CO2 during sunflecks. We conclude that elevated CO2 affects dynamic gas exchange most strongly via photosynthetic enhancement during induction as well as in the steady state.
Direct U–Th dating of marine sediments from the two most recent interglacial periods

A KNOWLEDGE of the age of marine sediments is necessary to determine the timing of events and rates of processes in the marine realm, and the relationships among marine and other climatically sensitive records. The establishment of an accurate chronology for Pleistocene marine sediments beyond the range of radiocarbon dating (approximately the past 45 kyr) has therefore been a goal of palaeoceanographers for decades. Early attempts1,2 based on measurements of the radionuclides 230Th and 231Pa were beset with problems, and subsequent studies focused on tying fluctuations in marine sediment oxygen-isotope records to events such as the formation of coral reef terraces and changes in the Earth's magnetic polarity3,4, and tuning the resultant chronologies to the Earth's orbitally driven insolation variations5–8. But these chronologies (especially the age and duration of the last interglacial period) have been challenged by several studies9–12, raising questions about the fundamental cause of Pleistocene climate fluctuations. Here we report the direct U–Th dating of aragonite-rich marine sediments from the Bahamas, and present an accurately dated marine oxygen-isotope record for the last two interglacials. We obtain dates of 120–127 kyr BP for the last interglacial and 189–190 kyr BP for the late stage 7 interglacial. These dates are in accord with the general theory of orbitally forced climate fluctuations and demonstrate the potential of our direct-dating approach for developing an absolute chronology for the Pleistocene marine oxygen-isotope record.
Polymer Surface Modification: Topography Effects Leading to Extreme Wettability Behavior

The surface oxidation of polyethylene (PE) and the surface reduction of Teflon (FEP) were studied with regard to the surface topography of the film samples that were used and the resulting water wettability. Anodized aluminum membranes were used as nanomolds to impart fibrillar topographies to the polymer surfaces. Water contact angles of smooth PE (θA/θR = 93°/75°) decreased to θA/θR = 68°/46° upon oxidation with potassium chlorate/sulfuric acid solution. Smooth FEP film samples changed from θA/θR = 111°/100° to θA/θR = 64°/45° upon reduction with sodium naphthalide solution. Contact angles of PE and FEP increased to 172°/160° and 174°/172°, respectively, upon introduction of the fibrillar topography and both decreased to ∼0°/0° after oxidation and reduction, respectively. That topography can be used as a tool in polymer surface modification is emphasized.
MULTIPLE ELECTRON TUNNELING PATHS ACROSS SELF-ASSEMBLED MONOLAYERS OF ALKANETHIOLS WITH ATTACHED RUTHENIUM(II/III) REDOX CENTERS

Alkanethiol monolayers with pendant redox centers are deposited on gold electrodes by self-assembly. The monolayers are composed of both an electroactive thiol, HS(CH2)nC(O)NHCH2pyRu(NH3)52+/3+, with 10−15 methylene groups, and a diluent thiol, HS(CH2)mCOOH, also with 10−15 methylene groups. The monolayers are classified as “matched” (n = m), “exposed” (n = 15, m = 10−14), and “buried” (n = 10, m = 11−15) according to the relative position of the redox center. Cyclic voltammograms in aqueous Na2SO4 indicate that the monolayers are close-packed with the redox centers residing in the aqueous phase in all but the most buried cases. Measurements of electron transfer kinetics by several methods (cyclic voltammetry, ac impedance spectroscopy, chronoamperometry) yield an internally consistent set of kinetic parameters, the standard rate constant k°, and the reorganization energy λ of the redox centers. The reorganization energies are in good agreement with the theoretically predicted value of 1.0 eV for the pyRu...
A Question of Authority: Religion and Cultural Conflict in the 2004 Election

In this study I adopt a view of cultural conflict that extends beyond the usual set of controversial “moral” issues like abortion and gay rights to include symbolic issues related to patriotism and group affect. Using a set of survey items asking about respondents’ preferences in child-rearing, I create a measure of individuals’ orientations toward authority that proves to be a potent predictor of attitudes on cultural issues, affect toward social groups, party identification, and vote choice. This authority effect persists even in the presence of extensive multivariate controls for demographic and religious variables. I find that both authority measures and religion measures shape political attitudes, suggesting the need for a multi-faceted approach to understanding cultural conflict.
A comparison of the cyclic variation in serum levels of CA125 across the menstrual cycle using two commercial assays

Background: Clinicians use CA125, a tumor-associated antigen, primarily to monitor epithelial ovarian cancer. However, CA125 lacks the sensitivity and specificity necessary for population-based scr...
Insulin and IGF-I attenuate the coronary vasoconstrictor effects of endothelin-1 but not of sarafotoxin 6c

Objective: To examine the hypothesis that insulin and insulin-like growth factor I (IGF-I) attenuate endothelin-induced contraction of porcine coronary epicardial arteries in vitro. Background: Endothelin-induced coronary vasoconstriction is mediated by two types of receptors, A (ETA) and B (ETB), resulting in calcium influx. Both insulin and IGF-I attenuate endothelin-induced calcium influx into porcine coronary artery smooth muscle. Methods: Epicardial arteries harvested from juvenile pigs were contracted with cumulative concentrations of endothelin-1 (ETA- and ETB-receptor agonist; 10−10–10−6 M) or of sarafotoxin-6c (ETB-receptor agonist; 10−11–10−7 M). In additional experiments, endothelin-1 or sarafotoxin-6c were added after incubation with 10−8 M regular insulin or IGF-I. These experiments were repeated in vessels without endothelium. Contraction for each vessel was calculated relative to the response to 60 mM KCl. Results: The maximal contractions to endothelin-1 in vessels with and without endothelium were 158±8 and 200±21%, respectively ( p <0.05 at 10−8.5–10−6.5 M). Both insulin (at 10−7–10−6 M) and IGF-I (at 10−6.5–10−6 M) attenuated the contraction to endothelin-1 in vessels with intact endothelium, as well as in vessels without endothelium (at 10−7 and 10−6 M for insulin and 10−7.5–10−6 M for IGF-I). The maximal contractions to sarafotoxin-6c in vessels with and without endothelium were 54±13 and 84±7%, respectively ( p <0.05 at 10−9, 10−8.5 and 10−7 M). Insulin and IGF-I did not affect the response to sarafotoxin-6c in vessels with and without endothelium. Conclusion: Insulin and IGF-I attenuated ETA-receptor-mediated coronary contraction through an endothelium-independent mechanism. The IGF axis may serve as an endogenous modulator of endothelin-mediated vasoconstriction.
Strategic Collaboration: Building a Major League Technology Infrastructure on a Small College Budget

This chapter describes how a small college with limited resources can provide a competitive multipurpose information technology infrastructure that is at the same level as found at major doctoral research universities.
Atherosclerosis in Cebus albifrons monkeys. 1. Sterol metabolism.

Summary Adult and young male and female Cebus albifrons monkeys exhibit differences in levels of serum cholesterol in response to cholesterol-containing diets; adult males had the highest levels, young males the lowest, and females of either age had values that were intermediate between the two groups of males. No differences were detectable among similar age and sex groups maintained on control diets to which no cholesterol was added. The kinetic characteristics of the disappearance of cholesterol- 14 C-containing lipoprotein were studied treating the system as a two-pool model. These studies indicated that adult males have a larger amount of cholesterol than do the other groups of monkeys in that pool which is represented by plasma plus those tissues that are in ready equilibrium with it. Similarly, adult males clear from their plasma each day a larger absolute amount of cholesterol, up to 200 mg/day, but this amount represents a smaller fraction of the total cholesterol present in this plasma-tissue pool. Using an isotopic method, the excretion of fecal bile acids and neutral sterols was studied. Results suggest that a large percentage of the sterol cleared from the plasma each day is excreted in the feces, and is made up of approximately equal amounts of bile acids and neutral sterols. Analysis of representative tissues of the animals for cholesterol, however, indicate that monkeys which showed the maximum elevation of serum cholesterol also had an expanded whole-body cholesterol pool. The distribution of cholesterol- 14 C in the tissues of the monkeys was studied after the semilogarithmic plasma die-away curve became linear with time. Results indicated a high degree of individuality among the different monkeys, and among different tissues from the same monkey.
Government Access to Private-Sector Data

The paper is discussing government's access to private enterprise data to administer social service schemes, tax calculations, law enforcement and national security purposes.
Structural heterogeneity in the lipopolysaccharide of Salmonella newington

Abstract Salmonella newington lipopolysaccharide extracted from a cell paste grown up from a single smooth clone was fractionated by chromatography on DEAE-cellulose in the presence of 1% Triton X-100 into seven lipopolysaccharide fractions which differed in their degrees of polymerization of the repeating unit of the O -antigen side chain and in their substitution with ester phosphate. Several of the lipopolysaccharide fractions were hydrolyzed in 1% acetic acid at 100 °C to cleave the linkage between the polysaccharide and lipid A parts of the structure. The polysaccharide fractions from each of the purified lipopolysaccharides could be further fractionated on DEAE-cellulose columns to yield a number of peaks of polysaccharide having monosaccharide ratios quite distinct from those of the parent lipopolysaccharide. The results show a high degree of structural heterogeneity in the original lipopolysaccharide.
Intercandidate Agenda Setting in the 2004 Democratic Presidential Primary

This study assesses candidate issue agendas and intercandidate agenda setting during the 2004 Democratic primary campaign. Candidate press releases, downloaded from official Web sites of Wesley Clark (n = 232), Howard Dean (n = 328), John Edwards (n = 512), and John Kerry (n = 459), are used to construct candidate issue agendas for each month spanning October 2003 through February 2004. This study investigates prominent issues among candidate agendas, agenda consistency, and intercandidate agenda-setting effects. Despite consistent issue agendas among the leading primary candidates, intercandidate agenda-setting effects were evidenced in each month of the primary campaign.
Transforming education for peace

edited by Jing Lin, Edward J. Brantmeier and Christa Bruhn, Charlotte, NC, Information Age Publishing, 2008, 340 pp., US$45.99 (paperback) and US$85.99 (hardback), ISBN 978-1-59311-905-8 The editor...
Four Views of the Professional School Counselor-Principal Relationship: A Q-Methodology Study.

This study in this article investigated how school counselors and principals perceive their professional relationship. Q methodology was used to develop 45 opinion statements about the relationship between school counselors and principals, and 39 professional school counselors and principals then sorted the statements. Four factors emerged representing different viewpoints of this relationship. Each contained constructive attributes of the school counselor-principal relationship, but one factor exhibited an appreciation of the context of interpersonal collaboration along with the content of school improvement initiatives.
Red Blood Cell Transfusion for Infants With Single-Ventricle Physiology

The purpose of this study was to assess how red blood cell (RBC) transfusions impact hemodynamic parameters in infants with single-ventricle lesions. This was a retrospective chart review. The setting was a pediatric cardiac intensive care unit at a tertiary care children’s hospital. Fifty-nine patients <1 year of age with single-ventricle physiology who received a blood transfusion between December 2007 and April 2009 were analyzed. They received a total of 183 transfusions. Exclusion criteria included transfusions given within 72 h of cardiac surgery or transfusions given to patients with active bleeding. There were no interventions. The study population was divided into terciles based on pretransfusion hemoglobin (Hgb) concentration. The pretransfusion Hgb concentration in group A was 7.8 to 12.3 gm/dl, in group B was 12.4 to 13.2 gm/dl, and in group C was 13.3 to 15.7 gm/dl. Heart rate, blood pressure, arterial saturation, and cerebral near-infrared spectroscopy (cNIRS) values before transfusion, as well as at 1, 2, 4, 8, and 12 h after transfusion, were collected. There was significant improvement in diastolic blood pressure, arterial saturation, and cNIRS in group A after 12 h. Transfusions given in group B also resulted in improvement in diastolic blood pressure and arterial saturation, with less robust response of cNIRS. In group C, only arterial saturation values increased significantly. RBC transfusions can improve hemodynamics and markers of oxygen delivery in infants with single-ventricle physiology, but further studies are needed to determine an optimal Hgb level in this population. Interventions to increase Hgb above this level may be of limited benefit.
How Accurately Can the Diffusion Profiles Indicate Multiple Fiber Orientations? A Study on General Fiber Crossings in Diffusion MRI

Abstract The q-space imaging techniques and high angular resolution diffusion (HARD) imaging have shown promise to identify intravoxel multiple fibers. The measured orientation distribution function (ODF) and apparent diffusion coefficient (ADC) profiles can be used to identify the orientations of the actual intravoxel fibers. The present study aims to examine the accuracy of these profile-based orientation methods by comparing the angular deviations between the estimated local maxima of the profiles and the real fiber orientation for a fiber crossing simulated with various intersection angles under different b values in diffusion-weighted MRI experiments. Both noisy and noise-free environments were investigated. The diffusion spectrum imaging (DSI), q-ball imaging (QBI), and HARD techniques were used to generate ODF and ADC profiles. To provide a better comparison between ODF and ADC techniques, the phase-corrected angular deviations were also presented for the ADC method based on a circular spectrum mapping method. The results indicate that systematic angular deviations exist between the actual fiber orientations and the corresponding local maxima of either the ADC or ODF profiles. All methods are apt to underestimation of acute intersection and overestimation of obtuse intersection angle. For a typical slow-exchange fiber crossing, the ODF methods have a non-deviation zone around the 90° intersection. Before the phase-correction, the deviation of ADC profiles approaches a peak at the 90° intersection, while after the correction the ADC deviations are significantly reduced. When the b factor is larger than 1000 s/mm2, the ODF methods have smaller angular deviations than the ADC methods for the intersections close to 90°. QBI method demonstrates a slight yet consistent advantage over the DSI method under the same conditions. In the noisy environment, the mean value of the deviation angles shows a high consistency with the corresponding deviation in the nose-free condition.
Changes in water extractable organic matter during incubation of forest floor material in the presence of quartz, goethite and gibbsite surfaces

Abstract The release of dissolved organic matter (DOM) from forest floor material constitutes a significant flux of C to the mineral soil in temperate forest ecosystems, with estimates on the order of 120–500 kg C ha −1 year −1 . Interaction of DOM with minerals and metals results in sorptive fractionation and stabilization of OM within the soil profile. Iron and aluminum oxides, in particular, have a significant effect on the quantity and quality of DOM transported through forest soils due to their high surface area and the toxic effects of dissolved aluminum on microbial communities. We directly examined these interactions by incubating forest floor material, including native microbiota, for 154 days in the presence of (1) goethite (α-FeOOH), (2) gibbsite (γ-Al(OH) 3 ), and (3) quartz (α-SiO 2 ) sand (as a control). Changes in molecular and thermal properties of water extractable organic matter (WEOM, as a proxy for DOM) were evaluated. WEOM was harvested on days 5, 10, 20, 30, 60, 90, and 154, and examined by thermogravimetry/differential thermal analysis (TG/DTA) and diffuse reflectance Fourier transform infrared (DRIFT) spectroscopy. Results indicated significant differences in WEOM quality among treatments, though the way in which oxide surfaces influenced WEOM properties did not seem to change significantly with increasing incubation time. Dissolved organic C concentrations were significantly lower in WEOM from the oxide treatments in comparison to the control treatment. Incubation with goethite produced WEOM with mid-to-high-range thermal lability that was depleted in both protein and fatty acids relative to the control. The average enthalpy of WEOM from the goethite treatment was significantly higher than either the gibbsite or control treatment, suggesting that interaction with goethite surfaces increases the energy content of WEOM. Incubation with gibbsite produced WEOM rich in thermally recalcitrant and carboxyl-rich compounds in comparison to the control treatment. These data indicate that interaction of WEOM with oxide surfaces significantly influences the composition of WEOM and that oxides play an important role in determining the biogeochemistry of forest soil DOM.
Laparoscopic Ureterocalicostomy: Initial Experience

Purpose: Ureterocalicostomy is a reconstructive option in the rare patient with surgically failed or difficult ureteropelvic junction (UPJ) obstruction with fibrosis and significant hydronephrosis. We introduce the technique of laparoscopic ureterocalicostomy. Materials and Methods: Laparoscopic ureterocalicostomy was performed in 2 patients, of whom 1 had UPJ obstruction and multiple secondary calculi in a dilated, dependent lower pole calix, and 1 had surgically failed UPJ obstruction with a scarred pelvis and significant hydronephrosis. Using a transperitoneal technique the UPJ was dismembered and suture ligated, the cut end of the ureter was spatulated, the attenuated lower pole renal parenchyma was amputated and mucosa-to-mucosa ureterocaliceal anastomosis was performed with running 4-zero absorbable suture over a stent. In the first case 32 renal calculi were also removed using a combination of laparoscopic nephroscopy and intraoperative ultrasonography. Results: In cases 1 and 2 operative time was 5.2 and 2.5 hours, estimated blood loss was 200 and 75 cc, and hospital stay was 2 days, respectively. There were no intraoperative complications. The stent was removed at 8 and 5 weeks, respectively. Postoperative retrograde pyelogram and diuretic renal scan confirmed anastomotic patency and improved drainage in each patient. At 9 months patient 1 remains without flank symptoms and a second renal scan at 6 months showed further improvement in drainage. Patient 2, who continued to be symptomatic with flank discomfort despite objective improvement in drainage parameters, elected secondary nephrectomy at 6 months. Conclusions: Laparoscopic ureterocalicostomy is feasible and it effectively duplicates established open surgical principles. To our knowledge the initial experience in the literature is presented.
Neoplastic transformation and DNA damage of mouse mammary epithelial cells by N-methyl-N′-nitrosourea in organ culture

Abstract An appropriate in vitro system was used to study the effect of a direct-acting carcinogen on the transformation of mammary epithelial cells in the organ culture of the whole mammary gland in vitro. Studies were done to determine the ability of N-methyl-N′-nitrosourea (MNU) to transform the mammary cells in organ culture. Mouse mammary glands were treated with single or multiple doses of MNU during various periods of the culture. To assay for neoplastic transformation potential of MNU on mammary cells, mammary glands were dissociated and the cells were injected into the parenchyma-free inguinal mammary fat pad of syngeneic virgin female host mice. Palpable tumors were observed in injected glands of 23% of the mice after 3–4 months and an additional 31% showed serially transplantable hyperplastic alveolar nodules (HANs). Histopathologic examination of the tissues showed that the tumors were mammary adenocarcinoma. All tumors and hyperplasias were secondarily transplanted into syngeneic animals, resulting in tumors and hyperplasias of similar histopathology. In addition, DNA damage of the epithelial cells in organ culture caused by MNU was also measurable using the new nick translation assay. The most extensive DNA damage occurred when the glands were treated on day 4 and day 5 of the mammogenic culture period. These results demonstrate that the mouse mammary epithelial cells are susceptible to the carcinogenic action of the direct-acting carcinogen MNU and that the whole mammary gland culture system offers an appropriate in vitro model for studying the mechanism of carcinogenesis induced by MNU.
THE SYMBOLIC CONSTRUCTION OF RUSSIA AND THE UNITED STATES ON RUSSIAN NATIONAL TELEVISION

Analysis of 1995 Vremya (Russian national television) newscasts reveals few traces of the cold-war framework that dominated news media discourse throughout the world for almost four decades. The ab...
A Distributed Model of the Electrical Response of Organic Molecules

Correlated ab initio calculations of the electrical properties of a large set of organic molecules have been carried out and used in the selection of transferable parameters in an additive model of electrical response. The set of parameters of the model consists of anisotropic atomic dipole polarizabilities for H, C, N, O, and F atoms in different bonding environments and bond dipole moments. The model uses a distribution of atomic dipole polarizabilities and bond dipoles according to the bonding and structure of a molecule. The model describes a molecule's long-range electrostatic potential and the change in that potential from polarization by an external electrostatic potential. To very good accuracy, it yields mean molecular dipole polarizabilities and magnitudes of dipole moments, and to good accuracy, it yields dipole polarizability anisotropies and dipole moment orientations. The capability of the model reinforces the idea that to a good extent molecular polarization is tied to electronic structure ...
Glycosyltransferase activity can be selectively modulated by chemical modifications of acceptor substrates

A range of N-acetyllactosamine derivatives, which are modified by a wide range of functionalities at C-2(') and C-6, have been synthesised and the kinetic parameters of transfer catalysed by recombinant alpha-2,6-sialyltransferase and alpha-1,3-fucoyltransferase VI determined. Several of the chemical modifications led to selective modulate the activity the enzymes and offer promising lead compounds for the development of oligosaccharide primers for selective metabolic inhibition of oligosaccharide biosynthesis.
Performance and complexity tradeoffs of space-time modulation and coding schemes

Wireless communication using multiple-input multiple-output (MIMO) systems improves throughput and enhances reliability for a given total transmit power. Achieving a higher data rate in MIMO systems requires utilizing an effective space-time coding and modulation scheme. The appropriate algorithm to use for a system will depend on parameters such as the number of transmit/receive antennas, target spectral efficiency, complexity limitations, channel environment, and other factors. In this paper, we examine the performance of various two-transmit and four-transmit space-time coding schemes under different channel types and target data rates. We compare the performance of state of the art space-time coding schemes including direct non-binary LDPC GF(q) modulation, bit interleaved coded modulation using iterative detection, and space-time trellis coded modulation. We obtain a tradeoff between performance and complexity of these various schemes.
Structure of pectate lyase A: comparison to other isoforms

Pectate lyase A is a virulence factor secreted by the plant-pathogenic bacteria Erwinia chrysanthemi. The enzyme cleaves the glycosidic bond of pectate polymers by a calcium-dependent β-elimination mechanism. The crystal structure of pectate lyase A from E. chrysanthemi EC16 has been determined in two crystal forms, monoclinic C2 to 1.8 A and rhombohedral R3 to 2.1 A. The protein structure is compared with two other pectate lyase isoforms from E. chrysanthemi EC16, pectate lyase C and pectate lyase E. Pectate lyase A is unique as it is the only acidic pectate lyase and has end products that are significantly more varied in length in comparison to those of the other four major pectate lyase isozymes. Differences and similarities in polypeptide trace, size and volume of the active-site groove and surface electrostatics are discussed.
Policy Instability in a Comparative Perspective: The Context of Heresthetic:

This article studies the factors that affect the likelihood of radical policy changes. Radical policy changes are defined here as acts in which political leaders choose a policy that is contradictory to policies they have committed to during elections and on whose basis they have formed coalitions. The reason for such changes is that quandaries change the policy space that shapes elections and initial coalitions. This change creates incentives for political players to re-bargain over existing coalitions. As the bargaining process decreases the leaders' survival prospects, the likelihood of leaders to opt for the ‘wrong side’ of the policy space will increase. I validate this claim using a case study and a large-N quantitative analysis of 51 cases from 34 countries.
Haplotype diversity in the equine myostatin gene with focus on variants associated with race distance propensity and muscle fiber type proportions

Two variants in the equine myostatin gene (MSTN), including a T/C SNP in the first intron and a 227-bp SINE insertion in the promoter, are associated with muscle fiber type proportions in the Quarter Horse (QH) and with the prediction of race distance propensity in the Thoroughbred (TB). Genotypes from these loci, along with 18 additional variants surrounding MSTN, were examined in 301 horses of 14 breeds to evaluate haplotype relationships and diversity. The C allele of intron 1 was found in 12 of 14 breeds at a frequency of 0.27; the SINE was observed in five breeds, but common in only the TB and QH (0.73 and 0.48 respectively). Haplotype data suggest the SINE insertion is contemporary to and arose upon a haplotype containing the intron 1 C allele. Gluteal muscle biopsies of TBs showed a significant association of the intron 1 C allele and SINE with a higher proportion of Type 2B and lower proportion of Type 1 fibers. However, in the Belgian horse, in which the SINE is not present, the intron 1 SNP was not associated with fiber type proportions, and evaluation of fiber type proportions across the Belgian, TB and QH breeds shows the significant effect of breed on fiber type proportions is negated when evaluating horses without the SINE variant. These data suggest the SINE, rather than the intron 1 SNP, is driving the observed muscle fiber type characteristics and is the variant targeted by selection for short-distance racing.
Sleep Problems in Childhood

Abstract Sleep, like eating and toileting, is an individual physical requirement that changes with time as the child matures. Although much about a child's sleep is biologically determined, extrinsic factors, usually through the parents, also mold the child's sleep behavior. Normal sleep for a child is restful to the child and not excessively disruptive to others. Sleep problems interfere with the quality of the child's sleep and frustrate or frighten caretakers. Several sleep problems have their origins in normal sleep behavior from an earlier age. Some, the parasomnias, are caused by self-limited biologic diatheses. Many sleep problems have psychosocial triggers. Sleep disorders only rarely are a primary medical problem that is adequately treated with medication (e.g., narcolepsy). Good history-taking, often accompanied by diary-keeping, will usually identify the problem— the first step in effective treatment. Treatment of a sleep disorder in the pediatric's office can start with educating caretakers about normative sleep for the age of the child and providing information regarding the cause and natural course of the problem. Treatment also may involve behavioral or psychological intervention or both, but medication is generally not indicated. When needed for short-term treatment, mild sedatives such as antihistamines are used most often. More serious sleep or behavioral problems should be acknowledged by the primary care pediatrician, followed by referral to an appropriate specialist. Inquiry into a child's sleep habits at each well-child visit, coupled with appropriate anticipatory guidance, could make an important contribution to the child and family by preventing problems with sleep and identifying sleep problems early in their evolution. Pediatricians and parents can work together to help chldren develop good sleep habits that fulfill the child's evolving sleep requirements within the context of the family's needs and expectations.
Perspectives on the Study of Man

Hocking’s inquiry into the nature of man, society, and political institutions is philosophical. He sees that “political problems, domestic or international, always involve us in psychological and philosophical issues.”1 His approach is that of the classical political philosophers — philosophical reflection on the basis of personal immersion in political life and dialogue with other thinkers engaged in similar reflection. He is thus a political philosopher in the tradition of Plato and Aristotle, Augustine and Aquinas, Hobbes and Locke. Since this approach may seem dated, it must be justified before a detailed treatment of his political thought can begin. This chapter is, however, more than an apology for a particular style of inquiry. It explores Hocking’s criticism of the method which now dominates the social sciences, and it discusses his justification for the approach of political philosophy.
The Asthma/Mental Health Nexus in a Population-Based Sample of the United States

Background Asthma is one of the most prevalent chronic medical conditions in the United States. The relationship of asthma with psychological factors has been known for centuries, and recently there has been a resurgence of interest in this topic. This study investigates the relationship between current asthma and poor mental health in a nationally representative sample of the US population. Methods This study utilizes data from the 2006 Behavioral Risk Factor Surveillance System survey (n = 355,710). A multinomial logistic regression model was constructed to assess the relationship between current asthma and poor mental health. The relationship between formerly having asthma and poor mental health was also investigated. Results Persons reporting poor mental health have increased risk of currently having asthma compared to persons reporting good mental health. Additionally, this asthma/mental health relationship has a “dose-response” relationship. For every incremental increase in days of poor mental health, there is a corresponding increase in risk of currently having asthma. Previously reported risk factors for asthma ( ie , age, gender, race, marital, smoking, overall health, exercise, obesity, and socioeconomic status) were all found to be important covariates of asthma. The relationship between former asthma and poor mental health is less clear. Conclusions This large, nationally representative sample confirms the relationship between asthma and mental health symptoms. Any degree of poor mental health appears to increase one's risk for asthma. Future research is needed to determine the causal and/or physiologic relationship between asthma and mental health symptoms.
An overview of sport tourism: Building towards a dimensional framework

The notion of people travelling to participate and watch sport dates back to the ancient Olympic Games and the practice of stimulating tourism through sport has existed for over a century. Just recently, however, sport and tourism professionals alike are realizing the significant potential of sport tourism and are aggressively pursuing this market niche. Although the definition of sport tourism may vary based on different people's interpretation of sport and travel, for the purpose of this article sport tourism refers to travel away from home to play sport, watch sport, or to visit a sport attraction including both competitive and non-competitive activities. Sport tourism can be broken down into five main categories: attractions, resorts, cruises, tours, and events. Each of these categories draws from other tourism sectors such as adventure tourism, health tourism, nature tourism, educational tourism, and leisure tourism. This article outlines the benefits and reasons for growth of sport tourism; provides...
Analysis of Cytadherence-Deficient, GapA-Negative Mycoplasma gallisepticum Strain R

Consistent with the interactions of typical noninvasive pathogenic bacteria and their host cells, Mycoplasma gallisepticum must first establish a specific and firm attachment to its target cell through a process known as cytadhesion in order to avoid rapid clearance by innate host defense mechanisms. This is a prerequisite for the initiation of the processes that result in host cell alterations and pathogenesis. Recent studies on the molecular mechanisms of M. gallisepticum cytadherence have revealed a complex multifactorial cytadhesion process involving the coordinate action of the primary cytadhesin molecule, GapA, while implicating additional proteins as potential cytadherence-related molecules in a manner reminiscent of the complex cytadherence mechanism of the human respiratory pathogen Mycoplasma pneumoniae. M. pneumoniae cytadherence has been demonstrated to involve the coordinate action of the primary cytadhesin molecule, P1 (11, 12, 21), in concert with an array of high-molecular-weight accessory proteins (7, 8). Prolonged colonization and survival of M. gallisepticum in the host requires maximal utilization of cytadhesin molecules in association with the cytadherence-related molecules. This ultimately confers a selective advantage for that strain of pathogenic M. gallisepticum over those with diminished cytadherence capacity. The aim of this study was to characterize the molecular basis for the diminished cytadherence capacity as well as to investigate the biochemical and molecular properties of the molecules observed to be involved in the phenotypic alterations in the avirulent R high strain.
Effects of norgestimate in combination with ethinyl estradiol on cervical mucus

The antifertility effect of norgestimate (Ng) 0.125 mg in combination with ethinyl estradiol (EE) 0.035 mg on cervical mucus of 5 apparently normal and ovulatory volunteer women was studied for 2 cycles: a control cycle followed by a study cycle in which the medication was given. Throughout both cycles, basal body temperature, cervical mucus properties, sperm penetration in cervical mucus and karyopyknotic index of vaginal cells were evaluated. Disappearance of cyclicity of these parameters in the study cycle as well as monophasic basal body temperature were suggestive of inhibition of ovulation caused by the combination pill. Deterioration of cervical mucus properties throughout the study cycle and inhibition of sperm penetration may be a reflection of anovulation. However, a direct antifertility effect of Ng on cervical mucus cannot be excluded.
Low-resolution density maps from atomic models: how stepping "back" can be a step "forward".

Abstract Atomic-resolution structures have had a tremendous impact on modern biological science. Much useful information also has been gleaned by merging and correlating atomic-resolution structural details with lower-resolution (15–40 A), three-dimensional (3D) reconstructions computed from images recorded with cryo-transmission electron microscopy (cryoTEM) procedures. One way to merge these structures involves reducing the resolution of an atomic model to a level comparable to a cryoTEM reconstruction. A low-resolution density map can be derived from an atomic-resolution structure by retrieving a set of atomic coordinates editing the coordinate file, computing structure factors from the model coordinates, and computing the inverse Fourier transform of the structure factors. This method is a useful tool for structural studies primarily in combination with 3D cryoTEM reconstructions. It has been used to assess the quality of 3D reconstructions, to determine corrections for the phase-contrast transfer function of the transmission electron microscope, to calibrate the dimensions and handedness of 3D reconstructions, to produce difference maps, to model features in macromolecules or macromolecular complexes, and to generate models to initiate model-based determination of particle orientation and origin parameters for 3D reconstruction.
An investigation on the effect of bending on UC-PBG structures

In this paper, we present the performance of the conventional Uniplanar Compact Photonic Band Gap (UC-PBG) structure operating as an Artificial Magnetic Conductor (AMC) under different bending conditions. The performance of the AMC is mainly characterized by the operational frequency and bandwidth which can be extracted from its reflection phase response. Modeling and numerical analysis of UC-PBG has been carried out using the commercially available software High Frequency Structure Simulator (HFSS) which is based on the Finite Element Method (FEM). We show that the extent of bending affect the reflection phase profile which in turn leads to operational frequency shift and bandwidth degradation. To the best knowledge of the authors, this kind of study is being conducted for the first time.
Supplemental Nutrition Assistance Program Participation Among Child Welfare–Involved Families

Using a national probability sample of families involved in child welfare, we estimated food stamp participation rates based on child placement following maltreatment investigation. Of the 69% of households that retained their child after investigation and were eligible for food stamps, 73% participated in the Supplemental Nutrition Assistance Program; of the 51% of kinship foster homes that were eligible, 58% participated; and of the 22% of traditional foster homes that were eligible, 26% participated. Participation rates for households involved in child welfare were lower than for households in the general population; traditional foster homes participated at the lowest rates. Outreach to child welfare–involved families and child welfare agencies are needed to increase enrollment.
RVBs are required for assembling a functional TIP60 complex.

RVB1/RVB2 (RuvBL1/RuvBL2 or pontin/reptin) are enigmatic AAA+ ATPase proteins that are present in multiple cellular complexes. Although they have been implicated in many cellular functions, the exact molecular function of RVB proteins in the various complexes is not clear. TIP60 complex (TIP60.com) is a tumor suppressor chromatin-remodeling complex containing RVB proteins. RVBs are required for the lysine acetyltransferase activity of TIP60.com but not for that of the pure recombinant TIP60 polypeptide. Here we describe two molecular functions of RVBs in TIP60.com. First, RVBs negate the repression of catalytic activity of TIP60 by another protein in TIP60.com, p400. RVBs competitively displace the SNF2 domain of p400 from the TIP60 polypeptide. In addition RVBs are also required for heat stability of TIP60.com by a p400-independent pathway. RVB1 and RVB2 are redundant with each other for these functions and do not require their ATPase activities. Thus, RVB proteins act as molecular adaptors that can substitute for one another to facilitate the optimal assembly, heat stability, and function of the TIP60 complex.