cssi/SciSciGPT-SciSciNet huggingface dataset:
Electro-enzymatic reduction of dioxygen to water in the cathode compartment of a biofuel cell

Abstract Due to slow kinetics of electron transfer, dioxygen is reduced at a platinum cathode several hundred millivolts negative of its formal potential. Biological catalysts, in combination with redox mediators, have the potential to circumvent the overpotential for the direct electroreduction of dioxygen to water. This paper describes how the redox mediator, 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonate), is used to reduce dioxygen to water using the fungal enzyme, laccase, as the catalyst for homogeneous electron transfer and the results obtained when this chemistry is used in the cathode compartment of a biofuel cell.
A scanning tunneling microscopy study of PH3 adsorption on Si(111)-7x7 surfaces, P-segregation and thermal desorption

Abstract PH3 adsorption on Si(1 1 1)-7 × 7 was studied after various exposures between 0.3 and 60 L at room temperature by means of scanning tunneling microscopy (STM). PH3-, PH2-, H-reacted, and unreacted adatoms can be identified by analyzing empty-state STM images at different sample biases. PHx-reacted rest-atoms can be observed in empty-state STM images if neighboring adatoms are hydrogen terminated. Most of the PH3 adsorbs dissociatively on the surface, generating H- and PH2-adsorbed rest-atom and adatom sites. Dangling-bonds at rest-atom sites are more reactive than adatom sites and the faulted half of the 7 × 7 unit cell is more reactive than the unfaulted half. Center adatoms are overwhelmingly preferred over corner adatoms for PH2 adsorption. The saturation P coverage is ∼0.18 ML. Annealing of PH3-reacted 7 × 7 surfaces at 900 K generates disordered, partially P-covered surfaces, but dosing PH3 at 900 K forms P/Si(1 1 1)- 6 3 surfaces. Si deposition at 510 K leaves disordered clusters on the surface, which cannot be reordered by annealing up to 800 K. However, annealing above 900 K recreates P/Si(1 1 1)- 6 3 surfaces. Surface morphologies formed by sequential rapid thermal annealing are also presented.
Strategies of Cultural Adaption in Intercultural Parenting

Twenty-one participants were interviewed about their experiences of parenting as intercultural couples, to understand how they navigate cultural differences within the family. Intercultural couples are defined in this study as heterosexual couples who have different sociocultural heritages with distinct cultures of origin as identified by the participants. All couples identified that either they or their parents were born and raised in a different country of origin from that of their partner’s. A grounded theory method was used for data analysis resulting in the development of a typology of cross-cultural parenting. The diverse strategies used by intercultural parents to negotiate diversity based on their cultural differences and their degree of mutual acculturation emerged to support this model. These strategies of adaptation included assimilation, cultural tourism, cultural transition, cultural amalgamation, and dual biculturalism. This framework can be used by mental health professionals to better unde...
An entropy-like index of bifurcational robustness for metabolic systems

Natural and synthetic metabolic pathways need to retain stability when faced against random changes in gene expression levels and kinetic parameters. In the presence of large parameter changes, a robust system should specifically avoid moving to an unstable region, an event that would dramatically change system behavior. Here we present an entropy-like index, denoted as S, for quantifying the bifurcational robustness of metabolic systems against loss of stability. We show that S enables the optimization of a metabolic model with respect to both bifurcational robustness and experimental data. We then demonstrate how the coupling of ensemble modeling and S enables us to discriminate alternative designs of a synthetic pathway according to bifurcational robustness. Finally, we show that S enables the identification of a key enzyme contributing to the bifurcational robustness of yeast glycolysis. The different applications of S demonstrated illustrate the versatile role it can play in constructing better metabolic models and designing functional non-native pathways.
Getting It Together: Temporal Coordination and Conflict Management in Global Virtual Teams

In this study, we examined the effects of temporal coordination on virtual teams supported by an asynchronous communication technology (Lotus Notes). Specifically, we evaluated the moderating role of a temporal coordination mechanism, process structure, on the relationship between conflict management behavior and virtual team performance. An experiment was conducted with 35 five-person teams in the United States and Japan. Our findings show that the way virtual teams manage internal conflict is a crucial factor in their success and that temporal coordination has some significant moderating effects.
Child abuse by adolescent caregivers

The purpose of this analysis was to estimate the frequency and severity of child abuse committed by adolescents who were in nonparental caregiving roles. The sample was composed of cases in which either physical or sexual abuse was substantiated through child welfare investigation. The main comparisons were between adolescent and adult caregivers. While caregiver age did not appear to have a consistent effect on the occurrence of physical abuse, notable differences between adolescents and adults were found in the area of sexual abuse. Not only were adolescents observed to commit substantially more sexual abuse than older caregiver cohorts, but the sexual abuse they committed was more likely to involve intercourse and physical assault. These findings have implications for future research and practice.
Comparison of ab initio , semiempirical, and molecular mechanics calculations for the conformational analysis of ring systems

The potential energy surfaces of four cyclic alkanes have been examined using molecular mechanics, semiempirical, and ab initio methods to determine if they produce mutually consistent results and investigate the source of any errors between the methods. The C5 C8 cyclic alkanes were chosen since these structures present a finite set of conformations and transition-state geometries and are still within the computational time and memory limits of the quantum mechanical approaches. We also examined several conformations of 1,2-dideoxyribose to determine the effect of heteroatoms on the results for the 5-membered ring. The molecular mechanics and ab initio calculations are consistent in the relative energies and geometries determined for the conformers of all ring systems. While the semiempirical calculations yielded geometries consistent with the other methods (except for 5-membered rings), the relative energies often deviated substantially. A decomposition analysis of the semiempirical and molecular mechanics energies revealed that the disparities are mainly due to errors in the 1-center energies of the semiempirical calculations. The 2-center bonding and nonbonding energies followed reasonable trends for the conformers. The core-repulsion function, however, is suspected of producing anomalies. A minimum in the attractive Gaussian of this term at 2.1 A for HH interactions partly explains the propensity of the 5-membered rings to optimize to near planarity (decreasing 1,2-diaxial hydrogen distances to 2.3 A) and the underestimation of the relative energy of the boat structure of cyclohexane.
A generalized approach to the analysis of infinite planar array antennas

In this paper a generalized expression for the complex power radiated by an element in an infinite planar array antenna is derived. Since this power formula applies to a large class of phased array antennas where the aperture field distribution can be completely specified (in normal mode form), it proves to be a powerful, unifying principle. The utility of this approach is illustrated by the simplicity with which previously known results can be derived; e.g., an infinite array of slots in a ground plane and an infinite array of flat dipoles with or without a ground plane. Further demonstrations of the usefulness of the power formula are provided by the systematic and straightforward solutions of the less-well-known problems of infinite arrays of crossed-dipole pairs and infinite arrays of open-ended rectangular waveguides. The waveguide array solution is particularly interesting because it reduces to a set of equations which are identical to those one would use to characterize an N-port network on an admittance basis (N is the number of waveguide modes). Since the power formula is derived for a parallelogram element Lattice, the resultant solution for a specific type of element is in its most general form. Expressions for the scan-dependent, dominant mode radiation admittance and the element gain function for a multimode rectangular waveguide radiator are also derived. In addition, various aspects of the waveguide array solution are investigated in the light of previous studies of infinite arrays.
Molecular dynamics simulations of consolidation processes during fabrication of nanophase palladium

Abstract Consolidation processes during fabrication of nanophase palladium from atom clusters are simulated using molecular statics (MS), molecular dynamics (MD), and a potential from the emebedded atom ,ethod (EAM). The MD simulations are conducte3d under conditions similar experimental conditions, i.e., at room temperature (300 K) and under compressive pressures of 10–50 kbar (1–5 GPa). Several dynamic phenomena have been observed during the simulations, such as “neck” formation, surface rounding, void formation and shrinking, and cluster extrusion. The effect of applied compressive pressures on the final structures of nanophase materials during considation is demonstrated.
The role of convection in drying

Abstract An analytical solution is presented for drying a material from one side. The material intially contains a solid or liquid phase. A quasi-steady model is adopted since the usual drying situation is slow and sensible heating effects are small compared to the latent heat of phase change. The thermal properties are constant and the thermal boundary conditions involve constant temperatures at the following positions: the heated surface, the interface between the dry and frozen regions and the back surface of the material. An ‘exact’ solution is found for the drying rate and temperature distribution in the drying material. A partially numerical solution and an approximate closed form solution are presented for the drying time. All equations are presented in non-dimensional form. For the usual range of parameters involved in drying problems of this type, the results show that the approximate solution for drying time is accurate within 2 per cent. The analysis can be used in a simple manner to extend and check and the validity of the approximate solution.
Disordered Eating in Female Alcohol-Dependent Inpatients: Prevalence and Associated Psychopathology

Abstract This study's aims were twofold: to examine the prevalence rate of eating disorders in women hospitalized for substance abuse treatment and to analyze differences in psychopathology of three patient groups: 25 alcohol-dependent women without comorbid eating disorders, 15 alcohol-dependent women with partial syndromes of eating disorders, and 41 eating-disordered women without comorbid psychoactive substance use disorders. A higher prevalence rate of eating disorder synptomatology (38%) was detected among inpatient alcohol-dependent women than is found in studies examining community samples. Subjects diagnosed with comorbid eating disorder symptoms and alcohol dependence scored signijicantly higher than those with alcohol dependence alone on scales measuring borderline personality disorder. Subjects with comorbidity also scored significantly higher on bonlerline, antisocial, and bbolar scales than those with single diagnoses of eating disorders. Results indicate that, for better assessment and trea...
AGGREGATION AND COMPLETION OF RANDOM SETS WITH DISTRIBUTIONAL FUZZY MEASURES

The two known information theories, probability and possibility theory, are based on t-conorm decomposable fuzzy measures, so that bijective mappings exist between their set-valued measures and their point-valued distributions. Further, their random set (Dempster-Shafer evidence theoretical) interpretations have simple topological structures, with bijective mappings between the subset focal elements and the point singletons. We introduce the concepts of distributional and aggregable random sets and random set completion, and first use them as a model in which to cast probability and possibility measures and distributions. Then, towards the goal of deriving new forms of information theory, general Sugeno conorm decomposable fuzzy measures and ring-like aggregable random sets with set-intersection structural aggregation are examined, but it is shown that in these two cases no new information theories are forthcoming.
Electrophoretic profiles and amino acid composition of rice endosperm proteins of a mutant with enhanced lysine and total protein after backcrosses for germplasm improvements

Seed storage proteins from in vitro-derived rice mutants improved by several backcrosses to ‘Calrose 76’ and BC2 and BC3 were characterized for changes in five different solubility classes. Albumins, rsealb (water-soluble globulins), true salt-soluble globulins, prolamins and glutelins were SDS-PAGE separated in a single dimension, and some two-dimensionally, to identify protein modifications. The genetic transmission of the enhanced-lysine mutants in backcrosses and the linkage of lysine with grain chalkiness were confirmed. Advanced lines had altered globulin profiles similar to those of unimproved lines. Chalky/ enhanced-lysine phenotypes had similar prolamin and glutelin profiles in the mutant and controls at the same protein level. Mutants had increased levels of globulins at 50 kDa and 33 kDa but had substantially less protein at 25 kDa than the controls. High protein in the mutant contributed to an increase in prolamins and the major storage proteins in both the globulins and glutelins. A significant decrease in low-molecular-weight, 15- to 18-kDa albumins was associated with the chalky/enhanced-lysine mutant phenotype. Two proteins in the 15- to 18-kDa group were amino acid sequenced, and database comparisons identified these proteins as allergens. Advanced lines downregulated for allergens and with enhanced-lysine/protein but with normal fertility and seed weight should be useful in breeding programs for nutritional quality.
Propagation of Longitudinal Waves in Circularly Cylindrical Bone Elements

TWO-PHASE POROELASTIC MATERIAL IS TAKEN AS A MODEL OF THE LIVING BONE IN THE SENSE THAT THE OSSEOUS TISSUE IS TREATED AS A LINEAR, ISOTROPIC, PERFECTLY ELASTIC SOLID, AND THE FLUID SUBSTANCES FILLING THE PORES AS A PERFECT FLUID. USING BIOT'S EQUATIONS, DERIVED IN HIS CONSOLIDATION THEORY, FOUR COUPLED GOVERNING DIFFERENTIAL EQUATIONS FOR THE PROPAGATION OF HARMONIC LONGITUDINAL WAVES IN CIRCULARLY CYLINDRICAL BARS OF POROELASTIC MATERIAL ARE DERIVED. A LONGER MANIPULATION REDUCES THE TASK OF SOLUTION TO A SINGLED ORDINARY DIFFERENTIAL EQUATION WITH VARIABLE COEFFICIENTS AND A REGULAR SINGULAR POINT. THE EQUATION IS SOLVED BY FROBENIUS' METHOD. THREE BOUNDARY CONDITIONS ON THE CURVED SURFACE OF THE BAR, EXPRESSING THE ABSENCE OF EXTERNAL LOADING AND THE PERMEABILITY OF THE SURFACE, SUPPLY A SYSTEM OF THREE LINEAR EQUATIONS IN THREE UNKNOWN COEFFICIENTS. A NONTRIVIAL SOLUTION OF THE SYSTEM GIVES TWO PHASE VELOCITIES OF PROPAGATION OF LONGITUDINAL WAVES IN AGREEMENT WITH THE FINDING OF BIOT FOR AN INFINITE MEDIUM. A SIMPLIFICATION OF THE PURELY ELASTIC CASE YIELDS THE ELEMENTARY CLASSICAL RESULT FOR THE LONGITUDINAL WAVES. /AUTHOR/
Contribution of Calcium Oxalate to Soil-Exchangeable Calcium

AbstractAcid deposition and repeated biomass harvest have decreased soil calcium (Ca) availability in many temperate forests worldwide, yet existing methods for assessing available soil Ca do not fully characterize soil Ca forms. To account for discrepancies in ecosystem Ca budgets, it has been hypo
DETERMINATION OF CERTAIN AMINO ACIDS IN CHYMOTRYPSINOGEN, AND ITS MOLECULAR WEIGHT.

1. A preparation of chymotrypsinogen, obtained from Dr. M. Kunitz, was analyzed for sulfur, the sulfur amino acids, tyrosine, and tryptophane. 2. The protein sulfur of chymotrypsinogen was accounted for as methionine, cysteine, and cystine. 3. A method is presented for calculating the minimum molecular weight of a protein from the distribution of the sulfur amino acids. In the case of chymotrypsinogen, the calculated minimum molecular weight was found to be the actual molecular weight. 4. The molecular weight of chymotrypsinogen is 36,700 by amino acid analysis as compared to 36,000 by osmotic pressure measurements of Kunitz and Northrop. Chymotrypsinogen contains per mol 17 atoms of sulfur, 3 residues of methionine, 4 of cysteine, 10 of half-cystine ( i.e . 5 S—S linkages), 6 of tyrosine, and 10 of tryptophane. 5. The tryptophane content of chymotrypsinogen (5.51 per cent) is the highest of any protein so far on record. 6. Chymotrypsinogen contains no reactive SH groups, although it yields cysteine on hydrolysis. This may be due either to preformed but unreactive SH groups or to S—X groups. The term S—X group is used to denote the substitution of the sulfhydryl hydrogen by a constituent X; hydrolysis yields SH groups: S—X + HOH = SH + X—OH.
Patients Discharged Against Medical Advice from a General Medicine Service

This study compares the demographic features and hospital course of all 472 patients discharged against medical advice from the general medicine service of an urban teaching hospital between 1984 and 1995 and 1,113 control patients discharged with physician approval. In the multivariate analysis, younger age (odds ratio [OR] 0.97 per year; 95% confidence interval [CI] 0.96, 0.98), male gender (OR 1.9; 95% CI 1.4, 2.4), lack of health insurance (OR 2.0; 95% CI 1.3, 3.1), Medicaid applicant or recipient status (OR 2.2; 95% CI 1.6, 3.1), admission through the emergency department (OR 2.2; 95% CI 1.4, 3.5), and lack of a personal attending physician at the time of admission (OR 2.1; 95% CI 1.6, 2.8) increased the odds of discharge against medical advice. Fifty-four percent of patients who left against medical advice were readmitted to the hospital during the study period; 98% were then discharged with physician approval. Patients who left the hospital against medical advice included many disadvantaged individuals without ongoing primary care.
Epinephrine-stimulated phosphorylation of pyruvate kinase in hepatocytes

Abstract Incubation of rat liver parenchymal cells with 10 −5 m epinephrine or norepinephrine resulted in a rapid incorporation of 32 P into pyruvate kinase. Inclusion of α-adrenergic blocking agents (phenoxybenzamine or phentolamine) in the hepatocyte incubation medium prior to addition of epinephrine suppressed the subsequent phosphorylation of pyruvate kinase. On the other hand, inclusion of the β-adrenergic antagonist, propranolol, in the hepatocyte incubation medium prior to addition of epinephrine did not suppress the epinephrine-elicited phosphorylation of pyruvate kinase. Exogenous addition of either cyclic AMP or cyclic GMP to the hepatocyte incubation medium also resulted in increased phosphorylation of pyruvate kinase. To investigate whether the same amino acid residue(s) of liver pyruvate kinase was being phosphorylated in each instance, 32 P-labeled pyruvate kinase was isolated from hepatocytes after incubation in the presence or absence of either glucagon or epinephrine. In addition, purified liver pyruvate kinase was phosphorylated in vitro with a rat liver cyclic AMP-dependent protein kinase. Each 32 P-labeled pyruvate kinase was then subjected to tryptic digestion, two-dimensional thin-layer peptide mapping, and autoradiography. Each 32 P-labeled pyruvate kinase sample yielded 44 to 48 tryptic peptides upon staining with ninhydrin and 4 peptides that contain 32 P as detected by autoradiography. Furthermore, the same 4 peptides of pyruvate kinase were radiolabeled in each instance. Thus phosphorylation of pyruvate kinase in vitro with [γ- 32 P]ATP or upon addition of either glucagon or epinephrine to hepatocytes incubated with 32 P i resulted in phosphorylation of the same amino acid residues.
An Appeal for Additional Research About the Development of Heterosexual Male Sexual Identity

Abstract For many heterosexual males, heterosexual male sexual identity is unmarked. That is, although it may motivate actions and behaviors (it is central), it does not appear to be cognitively available as an identity category (it is not salient). This contrasts with the marked sexual identity of most gay and bisexual males. By reviewing the scant research and theories about heterosexual male sexual identity development, and incorporating relevant studies of gay and bisexual male identity development, about masculinity, about puberty, and about general identity development, this article provides specific explanations for the unmarked nature of heterosexual male sexual identity and advocates for future research on this topic.
Synthesis and characterization of single-ion graft copolymer electrolytes

A microphase-separating single-ion conductor, poly[(oxyethylene)9 methacrylate-ran-lithium methacrylate]-graft-poly(dimethyl siloxane), P(OEM-r-LiMA)-g-PDMS, was prepared by lithiating a precursor polymer synthesized by free radical methods using commercially available macromonomers. This material possessed a low conductivity, stemming from high ion-pairing interactions that severely restricted the number of charge carriers available for conduction. Subsequent conversion of the LiMA units via the addition of BF 3 , a Lewis acid, resulted in a 2 orders-of-magnitude rise in conductivity, a gain that could be attributed to a large increase in the number of mobile cations. By blending this material with uncharged POEM-g-PDMS, the room-temperature conductivity was optimized to 7 X 10 - 6 S/cm. With a lithium transference number of unity, these materials exhibit higher dc-measured conductivities at elevated currents than their salt-doped counterparts and are electrochemically stable to -4.5 V.
Private tutoring in Eastern Europe and Central Asia: policy choices and implications

Private tutoring has become increasingly visible in Eastern Europe and Central Asia since the collapse of the socialist bloc in the early 1990s. Yet, this unprecedented growth of private tutoring, in its varied forms and arrangements, has remained largely unnoticed by policymakers in the region. Based on the data from the cross‐national studies of private tutoring in 12 countries, this explorative study examines factors driving the demand for private tutoring and discusses government responses to private tutoring in Azerbaijan, Bosnia and Herzegovina, Croatia, Georgia, Lithuania, Mongolia, Poland, Slovakia, and Ukraine (research conducted in 2004–2005) and Kazakhstan, Kyrgyzstan, and Tajikistan (research conducted in 2005–2006). The article analyzes various policy contexts and examines challenges that confront education stakeholders and policymakers as they formulate their responses to the rapidly‐spreading and constantly‐changing phenomenon of private tutoring. Finally, the article discusses whether, and...
A bottom-up control on fresh-bedrock topography under landscapes

The depth to unweathered bedrock beneath landscapes influences subsurface runoff paths, erosional processes, moisture availability to biota, and water flux to the atmosphere. Here we propose a quantitative model to predict the vertical extent of weathered rock underlying soil-mantled hillslopes. We hypothesize that once fresh bedrock, saturated with nearly stagnant fluid, is advected into the near surface through uplift and erosion, channel incision produces a lateral head gradient within the fresh bedrock inducing drainage toward the channel. Drainage of the fresh bedrock causes weathering through drying and permits the introduction of atmospheric and biotically controlled acids and oxidants such that the boundary between weathered and unweathered bedrock is set by the uppermost elevation of undrained fresh bedrock, Zb. The slow drainage of fresh bedrock exerts a “bottom up” control on the advance of the weathering front. The thickness of the weathered zone is calculated as the difference between the predicted topographic surface profile (driven by erosion) and the predicted groundwater profile (driven by drainage of fresh bedrock). For the steady-state, soil-mantled case, a coupled analytical solution arises in which both profiles are driven by channel incision. The model predicts a thickening of the weathered zone upslope and, consequently, a progressive upslope increase in the residence time of bedrock in the weathered zone. Two nondimensional numbers corresponding to the mean hillslope gradient and mean groundwater-table gradient emerge and their ratio defines the proportion of the hillslope relief that is unweathered. Field data from three field sites are consistent with model predictions.
The Effect of Low Temperature and Fasting during the Winter on Growth and Smoltification of Coho Salmon

Abstract This study examined the effect of winter feeding and fasting, under both warm (10°C) and cold (2.5°C) water temperatures, on smoltification of juvenile coho salmon Oncorhynchus kisutch. Treatments were warm–fed, warm–not fed, cold–fed, and cold–not fed during the winter (January–February) before smoltification in March–May. All groups were fed and maintained at 10°C during the smoltification period. The following variables were measured: Fork length, weight, condition factor, smolt-associated appearance, whole-body lipid levels, and gill Na+, K+-ATPase activity. Warm–fed fish grew continuously throughout the winter and were larger than fish from the other treatments. Fish from the other groups showed little or no growth during January and February. Although condition factors decreased significantly in the winter-fasted groups under both warm and cold temperatures, winter whole-body lipid levels and smoltification-associated gill Na+, K+-ATPase activities were not different among groups. These dat...
The Photo-Ionization of Potassium Vapor

Using a space-charge-neutralization method described in a recent publication the variation with wave-length of the ionization per unit light intensity ${B}_{\ensuremath{\nu}}$ in potassium vapor has been studied. ${B}_{\ensuremath{\nu}}$ exhibits maxima in the range 2100A to 3000A, one at the series limit, 2856A, and another at 2340A, the magnitude of the latter maximum being three times the former. A minimum value of ${B}_{\ensuremath{\nu}}$ occurs close to 2700A. Former results are shown to agree with the present much more accurate data though, because of the wide bands of wave-lengths used and the scantiness of observations, the earlier work failed to reveal the salient features here presented. The decrease of the ionization efficiency on both sides of the series limit is similar to the corresponding variation in caesium and rubidium and it seems probable, though not here proved, that the ionization by wave-lengths longer than the series limit is due to absorption of principal series lines. The increase of ${B}_{\ensuremath{\nu}}$ beyond the series limit has been attributed in the past to ionization of molecules. The present work shows that on this view the apparent molecular threshold occurs at 2700A and not at 2550A as estimated from earlier work. This fact in itself constitutes a serious objection to interpreting the observed variation of ${B}_{\ensuremath{\nu}}$ as a molecular phenomenon. It is pointed out that Williamson's observations of the emergent velocities of the photo-electrons show no evidence of molecularionization involving dissociation of the molecule and ionization of one of the atoms. Also Ditchburn's observations of the continuous optical absorption due to potassium atoms agree qualitatively with the present results. It thereby appears probable that the observed dependence on wave-length of ${B}_{\ensuremath{\nu}}$ is an atomic property of potassium.
Effects of Problem Definition and Formulation on the Generation of Alternatives in the Social Problem-Solving Process

The main purpose of the present study was to investigate the effects of training in D'Zurilla and Goldfried's (1971)procedure for defining and formulating socially oriented problems on performance in generating alternative solutions for such problems. A second objective was to replicate findings of a previous study which found support for the quantity principle on which the generation of alternatives component of this model is based. Results generally confirmed the original hypotheses, i.e., training in both these procedures independently increased the quality of solutions generated for two stimulus problems.
Hot for Teacher: Using Digital Music to Enhance Students' Experience in Online Courses

This article provides a review of the instructional potential of digital music to enhance postsecondary students’ experience in online courses by involving them in music-driven instructional activities. The authors describe how music-driven instructional activities, when used appropriately, can (a) humanize, personalize, and energize online courses by enhancing social presence through student-to-student interaction; (b) tap into students’ interests, and elicit positive feelings and associations; and (c) involve students in relevant and meaningful student-to-content interaction by engaging them in active knowledge construction. This article includes descriptions of several music-driven instructional activities that rely on digital music resources to engage students in generative, multisensory student-content interactions that leverage their interest in music, as well as a set of guidelines to support the design and use of music-driven instructional activities in online courses.
Effects of procainamide on strength-interval relations in normal and chronically infarcted canine myocardium

Abstract The effects of procainamide on strength-interval relations in normal and chronically infarcted canine myocardium were determined in nine adult mongrel dogs susceptible to sustained ventricular tachyarrhythmias. The dogs were studied at 3 to 30 days after two stage occlusion and reperfusion of the mid left anterior descending coronary artery. Unipolar cathodal stimulation (pulse duration 2 ms, drive cycle length 300 ms) was used to evaluate excitability and refractoriness at a total of 19 normal and 22 infarct sites both before and 15 to 30 minutes after intravenous infusion of procainamide, 20 to 25 mg/kg body weight. The electrophysiologic effects of procainamide were evaluated at the time of the plateau phase of procainamide's antiarrhythmic activity in this model. At normal sites, procainamide had only a minimal effect on the mean diastolic excitability threshold (increased from a mean [± standard deviation]of 0.07 ± 0.02 to 0.08 ± 0.02 mA [probability (p) = not significant (NS)], the mean effective refractory period (increased from 137 ± 10 to 139 ± 11 ms [p = NS]) and the mean ventricular refractory period at twice diastolic threshold (increased from 156 ± 12 to 163 ± 16 ms [p Thus, the antiarrhythmic activity of procainamide in this canine model of chronic myocardial infarction was not explained by an effect on the excitability or refractoriness of normal myocardium, by changes in the diastolic excitability of infarcted tissue or by an effect on the dispersion of refractoriness. The most prominent effect of procainamide was to decrease the excitability of abnormal myocardium during the relative refractory period and to prolong the refractoriness of abnormal myocardium.
Segmentations of MRI images of the female pelvic floor: a study of inter- and intra-reader reliability.

Qualitative and quantitative differences in the three-dimensional (3D) depiction of pelvic floor anatomy of asymptomatic nulliparous (1,2) and symptomatic women (3) have been reported. The transformation of two dimensional (2D) magnetic resonance imaging (MRI) data, obtained from thin-section images, to a 3D rendering is accomplished by manual segmentation, that is, serial outlining of each anatomic structure to be displayed in the 3D rendering. Subsequently, a series of advanced imaging processing techniques based on triangle decimation and the marching cubes algorithm is applied to form 3D objects that can be given color and opacity, and can be rotated and manipulated in space (4,5). The volume of any given 3D structure can be readily calculated, using voxel size information from the original MR scan. Image-based 3D reconstruction has proven to be a useful research technique for localizing and measuring the volume of tumors in the brain, kidneys and bladder (5–8). In several pelvic floor imaging studies, 3D renderings have been used to measure the volume of the levator ani in healthy women and those with incontinence, prolapse and other measures of pelvic floor dysfunction (1,3,6). In another study, 3D renderings were used to quantify diminished levator ani muscle mass in women with pelvic floor dysfunction (9). It is hypothesized that evaluation of 3D renderings may improve understanding of anatomical and pathophysiologic changes in women with pelvic floor disorders, However, the research utility of such comparisons depends on a standardized and reproducible technique for creating and measuring the 3D renderings (4). The purpose of the present analysis is to evaluate the inter- and intra-observer reliability of the segmentation technique used to generate the 3D renderings, applied to the bony and soft tissue structures of the female pelvis, as derived from MR images obtained using a standardized protocol.
Sucrose transport in plants

Physiological studies show that the driving force for long distance transport and the control of nutrient movement in plants resides largely in the regulated, membrane transport of a few carbohydrates, principally sucrose. The evidence is reviewed here and biochemical studies on sucrose carrier proteins are discussed.
Retinoid X receptor is a nonsilent major contributor to vitamin D receptor-mediated transcriptional activation

The vitamin D receptor (VDR) belongs to the thyroid hormone/retinoid receptor subfamily of nuclear receptors and functions as a heterodimer with retinoid X receptor (RXR). The RXR-VDR heterodimer, in contrast to other members of the class II nuclear receptor subfamily, is nonpermissive where RXR does not bind its cognate ligand, and therefore its role in VDR-mediated transactivation by liganded RXR-VDR has not been fully characterized. Here, we show a unique facet of the intermolecular RXR-VDR interaction, in which RXR actively participates in vitamin D3-dependent gene transcription. Using helix 3 and helix 12 mutants of VDR and RXR, we provide functional evidence that liganded VDR allosterically modifies RXR from an apo (unliganded)- to a holo (liganded)-receptor conformation, in the absence of RXR ligand. As a result of the proposed allosteric modification of RXR by liganded VDR, the heterodimerized RXR shows the "phantom ligand effect" and thus acquires the capability to recruit coactivators steroid receptor coactivator 1, transcriptional intermediary factor 2, and amplified in breast cancer-1. Finally, using a biochemical approach with purified proteins, we show that RXR augments the 1,25-dihydroxyvitamin D3-dependent recruitment of transcriptional intermediary factor 2 in the context of RXR-VDR heterodimer. These results confirm and extend the previous observations suggesting that RXR is a significant contributor to VDR-mediated gene expression and provide a mechanism by which RXR acts as a major contributor to vitamin D3-dependent transcription.
Modeling the interaction of electric current and tissue: Importance of accounting for time varying electric properties

Time varying computer models of the interaction of electric current and tissue are very valuable in helping to understand the complexity of the human body and biological tissue. The electrical properties of tissue, permittivity and conductivity, are vital to accurately modeling the interaction of the human tissue with electric current. Past models have represented the electric properties of the tissue as constant or temperature dependent. This paper presents time dependent electric properties that change as a result of tissue damage, temperature, blood flow, blood vessels, and tissue property. Six models are compared to emphasize the importance of accounting for these different tissue properties in the computer model. In particular, incorporating the time varying nature of the electric properties of human tissue into the model leads to a significant increase in tissue damage. An important feature of the model is the feedback loop created between the electric properties, tissue damage, and temperature.
Spatio-Temporal Sensor Graphs (STSG): A data model for the discovery of spatio-temporal patterns

Developing a model that facilitates the representation and knowledge discovery on sensor data presents many challenges. With sensors reporting data at a very high frequency, resulting in large volumes of data, there is a need for a model that is memory efficient. Since sensor data is spatio-temporal in nature, the model must also support the time dependence of the data. Balancing the conflicting requirements of simplicity, expressiveness and storage efficiency is challenging. The model should also provide adequate support for the formulation of efficient algorithms for knowledge discovery. Though spatio-temporal data can be modeled using time expanded graphs, this model replicates the entire graph across time instants, resulting in high storage overhead and computationally expensive algorithms. In this paper, we propose Spatio-Temporal Sensor Graphs (STSG) to model sensor data at the conceptual. logical and physical levels. This model allows the properties of edges and nodes to be modeled as a time series of measurement data. Data at each instant would consist of the measured value and the expected error. Also, we evaluate the model using methods to find interesting patterns such as growing hotspots in sensor data and present analytical comparison of the algorithms with methods based on existing models.
A selective and sensitive chromogenic and fluorogenic detection of a sulfur mustard simulant

A simple and highly selective chromogenic and fluorogenic detection of sulfur mustard (SM) simulants is reported. Dithiol 1, in the presence and absence of a mustard simulant behaves differently toward a squaraine dye (SQ), and thus provides a visual and spectroscopic signal for mustard gas. The sensor responds to the SM simulant, but not to the O-analog of mustard stimulant or nerve agent mimics and other electrophilic agents. The visual and fluorescent detection with less than 50 μM of SM simulant shows good sensitivity. The utility of the sensor was demonstrated by analysis of SM simulant on surfaces, in soil, and in the gas phase.
Report from the ASCB Education Committee.

The Education Committee of the American Society for Cell Biology is delighted to participate in the launch of Cell Biology Education. We plan to provide a regular column with information on our plans and programs, soliciting your input and participation. The Education Committee is one of the standing committees of the Society, as described in the Constitution and Bylaws. The Committee has undertaken a number of projects, sponsoring publications in cell biology such as the “Cellebrations” videotape edited by Rachel Fink, and the “Methods in Cell Biology” series edited by Leslie Wilson and Paul Matsudaira, published by Academic Press. We also sponsor publication of career information, for example “Exploring the cell: what cells do and how cell biologists study them,” for high school students, as well as the “How to get Get a Job . . . ” series for our younger members. Most recently, the Committee sponsored a study of education/workforce/career structure issues under the leadership of past chairman Frank Solomon. The results of this effort, funded by a grant from the Sloan Fondation, were published in Science (Freeman et al., 2001, “Competition and careers in biosciences,” 294, 2293–2294); the complete report “Careers and rewards in bio sciences: the disconnect between scientific progress and career progression,” by R.B. Freeman, E. Weinstein, E. Marincola, J. Rosenbaum, and F. Solomon, can be found on the ASCB web site at www.ascb.org/publications/competition.html. The Education Committee sponsors a number of events at the ASCB Annual Meeting. These are designed to showcase some of the outstanding work that our members are doing in life science education at every level to provide opportunities for networking among members interested in different issues in science education and to support the career development of our younger ASCB members. Committee members are now hard at work, planning/ organizing events for the ASCB Annual Meeting, to be held this year in San Francisco on December 14–18. We want your suggestions and your participation! The Education Poster Session this year will be scheduled for Monday, December 9. Education posters can cover a wide variety of topics, including descriptions of new programs, innovative teaching approaches and laboratory and/or computer-based investigations by students. Work in graduate education, undergraduate education, and K–12 outreach are all appropriate. Remember that all ASCB members can contribute a poster in Education in addition to a poster on laboratory research, and we encourage you to do so. The Education Committee will continue to sponsor the Education Initiative Forum on Monday–Wednesday from 9:45 to
Experimental study of the response of 1–5 mm thick CdTe/CZT detectors inside strong magnetic field

In this study, we experimentally investigated the detailed charge collection process in CdTe ERPC detectors that are operated inside a strong magnetic field for MRI-compatible SPECT imaging system. As one of the key objectives, we quantitatively assessed the effect of the Lorenz force on the migration of charge carriers and signal induced inside the detector bulk. During the study, the ERPC detectors were set on a non-magnetic gantry that can be rotated inside a 3T MR scanner. Two collimations were used to form incident gamma ray events traveling onto the detector with known incident points and angles. One of them is a highly machined Tungsten collimator and the other one is the nine-pinhole aperture. Multiply studies were performed using the same experimental detection setup with and without the magnetic field to estimate the charge collection behavior in MRI environment. In addition, the detector coupled with collimator was placed at the different angular position in SPECT scanning to evaluate the second-order distortions caused by the inhomogeneity of the magnetic field. Meanwhile, we used a Monte Carlo simulation model to reproduce the charge collection behavior with and without presence of magnetic field. This accurate modeling of the ERPC detectors energy response helps to compensate the event-positioning error induced by the strong magnetic field and also evaluate effects of several physics factors in charge collection. Through this process, we derived an accurate system response function for the MRI-compatible SPECT system, which allows us to achieve ultrahigh spatial resolution of images obtained inside the MRI.
A rational synthesis of bullvalene barbaralone and derivatives; bullvalone☆

Abstract A rational synthesis of bullvalene (I) proceeds in seven steps from cycloheptatriene-7-carboxylic acid by way of cycloheptatriene-7-carbonyl chloride, cycloheptatrien-7-yl diazomethyl ketone (B-1), barbaralone (VI), bullvalone (V), 9-hydroxytricyclo [3.3.2.02, 8]deca-3,6-diene and 9-acetoxytricyclo-[3.3.2.02, 8]deca-3,6-diene (F-4). Discussion is concerned mainly with (a) an attempt to synthesize bullvalone (V) from cycloheptatriene-7-ylacetic acid (A-1) which instead produced the isomeric tricyclo[5.3.0.02, 10]-deca-3,5-dien-9-one (A-3); (b) the divinylcyclopropane rearrangement in barbaralone (V) and the theoretical relation of its very rapid rate to Cope rearrangement in acyclic systems; (c) the preparation and fluxional quality of barbaralane (VII); (d) the thermal reorganization of bullvalene (I) to cis-9,10-dihydronaphthalene (IX); (e) the preparation of methyl- and phenyl-bullvalene; and (f) the exchange of all ten hydrogen atoms in bullvalone (V) by deuterium and the bearing of this observation on the fluxionality of bullvalene (I).
Osteoporosis prevention and therapy: preserving and building strength through bone quality

While bone mineral density measurements play a central role in osteoporosis management, the degree to which increases in this parameter contribute to bone fragility, fracture risk, and the therapeutic efficacy of osteoporosis agents is controversial. Indeed, bone strength is also significantly dependent upon bone turnover and bone quality, including microarchitecture, mineralization, and geometry. Given the critical role of these factors, it is essential to understand how they are affected by therapeutic agents. Even though a number of technological advances, such as microcomputed tomography, magnetic resonance imaging, and computerized analysis of radiographic patterns, help to provide critical information toward a more comprehensive assessment of bone turnover and bone quality, clinical trials addressing these factors are scarce. This article provides a review of studies relating to how osteoporosis therapies impact parameters of bone strength and quality.
Improving the lazy Krivine machine

Krivine presents the $\mathcal {K}$ machine, which produces weak head normal form results. Sestoft introduces several call-by-need variants of the ${\mathcal {K}}$ machine that implement result sharing via pushing update markers on the stack in a way similar to the TIM and the STG machine. When a sequence of consecutive markers appears on the stack, all but the first cause redundant updates. Improvements related to these sequences have dealt with either the consumption of the markers or the removal of the markers once they appear. Here we present an improvement that eliminates the production of marker sequences of length greater than one. This improvement results in the ${\mathcal {C}}$ machine, a more space and time efficient variant of ${\mathcal {K}}$ . We then apply the classic optimization of short-circuiting operand variable dereferences to create the call-by-need ${\mathcal {S}}$ machine. Finally, we combine the two improvements in the ${\mathcal {CS}}$ machine. On our benchmarks this machine uses half the stack space, performs one quarter as many updates, and executes between 27% faster and 17% slower than our ? variant of Sestoft's lazy Krivine machine. More interesting is that on one benchmark ?, ${\mathcal {S}}$ , and ${\mathcal {C}}$ consume unbounded space, but ${\mathcal {CS}}$ consumes constant space. Our comparisons to Sestoft's Mark 2 machine are not exact, however, since we restrict ourselves to unpreprocessed closed lambda terms. Our variant of his machine does no environment trimming, conversion to deBruijn-style variable access, and does not provide basic constants, data type constructors, or the recursive let. (The Y combinator is used instead.)