cssi/SciSciGPT-SciSciNet huggingface dataset:
Development of the gastrointestinal mucosal barrier. Evidence for structural differences in microvillus membranes from newborn and adult rabbits

Abstract Electron spin resonance (ESR) and spin label methods with 5-doxylstearic acid as a probe were used to investigate the structure of microvillus membrane from the small intestine of adult and newborn rabbits. The spin label in microvillus membrane of newborns appeared to be in a more disordered environment than spin label in microvillus membrane of adult animals in the temperature range from 4 to 56°C. In addition, a temperature transition at 39.6 ± 0.3°C was observed in the temperature dependence of the hyperfine splitting parameter for microvillus membrane from adult animals whereas a linear temperature dependence of the hyperfine splitting parameter was found for microvillus membrane from newborns. Cholera toxin was used as an external stimulus to test for the structural response in these two membrane preparations. Cholera toxin at 6 pM caused a decrease in the hyperfine splitting parameter at temperatures below 40°C and a shift in the temperature break from 39.6°C to 30.7°C in microvillus membrane from adults. Using microvillus membrane from newborns, the temperature dependence of the hyperfine splitting parameter remained linear with a cholera toxin stimulus and the disordering effect of cholera toxin was only observed below 30°C. These studies suggested that microvillus membrane from newborns were inherently more disordered than microvillus membrane from adult animals and that this difference in membrane organization might in part account for the increased attachment and penetration of macromolecules noted during the perinatal period.
Toward Ultrafast In Situ X-ray Studies of Interfacial Photoelectrochemistry

Picosecond time-resolved in situ X-ray absorption and X-ray photoelectron spectroscopy techniques for atomic site-specific real-time studies of interfacial photoelectrochemistry are developed at the Advanced Light Source (ALS). First experiments monitor electronic dynamics in films of dye-sensitized nanocrystals and at hematite-electrolyte interfaces.
Composting by-products from a bleached kraft pulping process: effect of type and amount of nitrogen amendments

Over 70% of solid wastes (by-products) generated in the manufacture of paper pulp are presently disposed of in landfills. Most of these by-products are compostable and reusable in horticulture, landscaping and agriculture. This work addresses the questions of nitrogen amendments required for composting a mix of four bleached kraft pulp mill by-products — namely, primary sludge, bark, grit and ash. Two nitrogen amendments, ammonium nitrate and chicken litter were compared to determine which provided a more rapid mass reduction and stabilization. Different amounts of ammonium nitrate addition were evaluated to determine if decreasing the C:N ratio of the initial mix (from 130.9 to 28.3) resulted in more rapid composting. A blend of sludge, grit, bark and ash in dry weight percentages of 56, 25, 6 and 13% respectively, stabilized (measured using oxygen respirometry) in a period of 28 days. Although in the initial stages of composting there were differences resulting from the effect of the two types of nitrog...
Catalytic mechanism of Sep-tRNA:Cys-tRNA synthase: sulfur transfer is mediated by disulfide and persulfide.

Sep-tRNA:Cys-tRNA synthase (SepCysS) catalyzes the sulfhydrylation of tRNA-bound O-phosphoserine (Sep) to form cysteinyl-tRNACys (Cys-tRNACys) in methanogens that lack the canonical cysteinyl-tRNA synthetase (CysRS). A crystal structure of the Archaeoglobus fulgidus SepCysS apoenzyme provides information on the binding of the pyridoxal phosphate cofactor as well as on amino acid residues that may be involved in substrate binding. However, the mechanism of sulfur transfer to form cysteine was not known. Using an in vivo Escherichia coli complementation assay, we showed that all three highly conserved Cys residues in SepCysS (Cys64, Cys67, and Cys272 in the Methanocaldococcus jannaschii enzyme) are essential for the sulfhydrylation reaction in vivo. Biochemical and mass spectrometric analysis demonstrated that Cys64 and Cys67 form a disulfide linkage and carry a sulfane sulfur in a portion of the enzyme. These results suggest that a persulfide group (containing a sulfane sulfur) is the proximal sulfur donor for cysteine biosynthesis. The presence of Cys272 increased the amount of sulfane sulfur in SepCysS by 3-fold, suggesting that this Cys residue facilitates the generation of the persulfide group. Based upon these findings, we propose for SepCysS a sulfur relay mechanism that recruits both disulfide and persulfide intermediates.
Assessing the validity of contingent valuation: Three field experiments

Abstract Contingent valuation, in social psychological terms, is a measure of behavioral intention (BI), or what people say they will do on surveys. Market values, on the other hand, are obtained through observable buying and selling behaviors (B). The relationship between BI and B was explored in three field experiments. Hunters had an opportunity to sell their free but difficult to obtain hunting permits or buy such a permit. When it came to selling permits in a take it or leave it situation, the amount people said they would take was 60 percent higher in one experiment and 200 percent higher in the other than what they actually sold it for. Willingness to sell values were greatly inflated by using a sealed bid auction, and in this case hunters said they would take less than they really would take. For selling we conclude contingent valuation is not a good substitute for market behaviors. In contrast, willingness to pay is a much better indicator of what hunters actually paid to buy a permit. In two experiments, BI was 25 percent and 33 percent higher than B (N.S.). Further, the sealed bid auction gave the same results as dichotomous choice. Bidding in the willingness to pay situation increased the difference between BI and B. We speculated that because of repeated buying behaviors consumers have a pretty good idea of what they will pay and can answer correctly on a survey. In contrast they seldom sell things, especially hunting permits, and do not have a good idea of what they really will sell for until confronted with cash.
Medical students' attitudes toward underserved patients: a longitudinal comparison of problem-based and traditional medical curricula.

Medical education has been shown to negatively influence student attitudes toward certain types of patient populations. Past research does not inform current educational practice because today’s medical school environment is different from when most of the published research was conducted. There are more female students, curricular innovations such as problem-based learning have changed the framework for educational delivery, and longitudinal studies, which could inform when interventions may be needed, are uncommon. The purposes of this longitudinal, prospective cohort study were to compare the attitudes of Problem-based learning and Traditional curriculum students toward providing care for medically indigent patients as they progressed through the four-year undergraduate medical education curriculum, and to determine if gender differences were apparent and persisted over time. Attitudes of one cohort of students enrolled in separate curricula were studied. The outcome measure was the Medical Student Attitudes Toward the Underserved questionnaire, which was administered three times. A linear mixed effects regression analysis was performed to examine changes in factor scores over time and whether these changes differed between Problem-based and Traditional students, and males and females. Longitudinal findings revealed that commitment to caring for the medically underserved was greater when students entered medical school than when they graduated. Students in both curricula, as well as male and female students, experienced increasingly negative attitudes over the four year period. Decline in attitudes toward medically underserved patients was similar to previous research results. This study showed that attitudes of students were not influenced by the preclinical curriculum they experienced.
Migrant Women Crossing Borders: The Role of Gender and Religion in Internal and External Mexican Migration

Abstract This article examines the migration experience of women crossing two different borders, international‐national and rural‐urban. Two ethnographic examples are provided to document women's transformations through migration. The first case deals with Mexican women crossing Mexico's northern border into Texas. The second case focuses on Maya women crossing the rural border of a Maya community to urban Cancun. The core of the study is the analysis of the parallelisms between these two cases, mainly expressed in the connections between religious conversion and socioeconomic transformations resulting from these women's migration experiences. The ethnographic method allows the comparison of the two cases of female migration and facilitates the understanding of the ideological transformation, expressed through the religious conversion, interwoven with changes in their migrant socioeconomic dynamics.
CAVAN'S CONTINUUM OF BEHAVIOR: A PROPOSED CONCEPTUAL MODEL FOR THE EXPANSION OF NARROWLY FOCUSED CRIMINOLOGICAL THEORY

ABSTRACT This paper is an effort to illustrate how Ruth Shonle Cavan's (1961) concept of the “continuum of behavior” can be used as another way to broaden criminological theory. Cavan's work was selected because her conceptualization lends itself most readily to a visual expansion of traditional theories. In addition, her “continuum of behavior” was chosen to highlight the work of an early pioneer woman in criminology whose contributions have been ignored and/or trivalized by mainstream theorists.
On the preferred orientation and microstructural manipulation of molecular sieve films prepared by secondary growth

MFI-supported films were prepared using secondary growth of precursor layers. The precursor layers were prepared free of additives and no calcination step was used before secondary growth. Combined microstructural control over film thickness, orientation, continuity, and surface roughness was achieved. Hydrothermal conditions were identified, such as film growth proceeds predominantly by direct growth of the particles of the precursor layer. The prepared polycrystalline films have a columnar microstructure. The out-of-plane grain orientation can be manipulated by secondary growth conditions, and is such that the c-axes of the grains range from perpendicular to the substrate to an angle of ∼34° from the direction normal to the substrate, whereas the in-plane grain orientation is random. Initial film growth rates were sustained at a constant value for extended periods of time with an activation energy of 70 kJ/mol. The degree of out-of-plane orientation increases with film thickness up to a point where chan...
Mary Chesnut's Civil War Epic

Mary Chesnut's Civil War Epic JULIA A. STERN Chicago: University of Chicago Press, 2010 Pp. 352, $45.00 (hbk), ISBN 978 0 2267 7328 5 Like numerous other ex-Confederates after the American Civil Wa...
Effective behavior of polycrystals that undergo martensitic phase transformation

The shape-memory effect is the ability of a material to recover, on heating, apparently plastic deformations that it suffers below a critical temperature. These apparently plastic strains are not caused by slip or dislocation, but by deformation twinning and the formation of other coherent microstructures by the symmetry-related variants of martensite. In single crystals, these strains depend on the transformation strain and can be quite large. However, in polycrystals made up of a large number of randomly oriented grains, the various grains may not deform cooperatively. Consequently, these recoverable strains depend on the texture and may be severely reduced or even eliminated. Thus, the shape-memory behavior of polycrystals may be significantly different from that of a single crystal. We address this issue by studying some model problems in the setting of anti-plane shear.
Community-Level Service Integration Within Home Visiting Programs:

National surveys were obtained from 193 programs serving children eligible for Part H who were identified by state-level administrators as demonstrating successful efforts in integrating services for families. Descriptive analyses were conducted to determine the service system models in place, the strategies used to facilitate service integration, the perceived barriers, and the relationship between the state-level systems and the community-level systems. A variety of successful strategies to facilitate integrated services were reported as being implemented at the community level, although there was limited coordination with hospitals, medical specialists, and mental health services. Insufficient funding for lower caseloads and compensation for service coordination efforts were perceived as the greatest barriers to system integration efforts. States supported communities primarily through the provision of information concerning policies and regulations; the use of other support strategies (e.g., needs ass...
Exploiting large register sets

Abstract The paper examines problems associated with the application of load-store RISC architectures with large register sets or compiler-driven register assignment to realtime system design methodologies involving many tasks and frequent context switches. Approaches to on-chip storage are reviewed and the threaded windows concept introduced as an efficient mechanism for managing register resources. Under this system the structure and use of registers may be dictated by the programmer, compiler and operating system according to the demands of procedure activation records, hardware-supported stacks, hardware-supported queues, and concurrent task contexts, as well as task and system global storage. The use and benefits of the system with sequential programs and in concurrent tasking environments are explored. The abilities and attributes of similar architectures are evaluated and planned developments of the threaded windows system are outlined.
Structure-reactivity correlation in atom transfer radical polymerization

Kinetics of atom transfer radical polymerization (ATRP) with the special emphasis on dynamics of activation and deactivation is discussed. Various mechanistic features of ATRP related to electron transfer processes are presented. Elementary reactions of ATRP process are analyzed.
TH‐E‐218‐02: Deformable Registration Techniques for Dual Energy Imaging in Clinical Radiotherapy

Purpose: To demonstrate a deformable registration algorithm to reduce cardiac and respiratory motion artifacts in planar dual energy (DE) subtraction images obtained using a clinical on‐board imaging (OBI) system. Methods: A Demons‐based deformable registration algorithm was developed to reduce motion artifacts between sequential planar x‐ray images obtained on the OBI. The algorithm was applied to paired (120 kVp and 60 kVp) chest x‐rays, deforming the low energy image to the high energy image. To test the algorithm, a total of 20‐paired scans were obtained from 6 lungcancer patients. All images were obtained using respiratory gating (RPM, Varian Medical Systems, Palo Alto, CA). In order to quantify the reduction in image artifacts, homologous landmarks were chosen using soft‐tissue features on both sets of images. Landmarks were placed throughout the images to examine both cardiac and respiratory motion. The root‐mean‐square (RMS) difference between the individual points was calculated both before and after application of deformable registration. Results: A total of 160 landmarks were evaluated. Measurement of the RMS distances between the landmarks in the high and low energy deformed images showed improvement in all sectors. For points with 2 mm RMS difference, the corresponding reduction was 64%. Qualitatively, DE images produced using Demons deformation showed fewer artifacts, and more defined tumor edges. Conclusions: The Demons algorithm reduced motion artifacts across all DE planar images. The greatest improvements were observed in regions near the diaphragm and the heart. In particular, artifacts due to cardiac motion showed the most improvement as these are not taken into account when performing respiratory gating. The iterative, matrix‐based algorithm would greatly benefit from integration of GPU parallel‐processing and will be implemented in future investigations. Supported by a grant from Varian Medical Systems.
Quantification of constraint on elastic–plastic 3D crack front by the J–A2 three-term solution

Abstract Three-dimensional (3D) modified boundary layer analyses are performed using the finite element method to study the crack-front constraint for an elastic–plastic thin plate. Far field loading is applied through the plane-stress displacement fields based on the elastic K I -field, and specimen constraint levels are varied through the T -stress applied on the far field boundary. Numerical stresses at the crack front at different planes of the plate are compared with those determined by the J–A 2 three-term solution. Results show that the in-plane-stress fields at the crack front for various K I – T loads possess the plane-strain nature throughout the thickness except for the region near the free surface, and can be characterized by the J–A 2 three-term solution under the small scale yielding condition. The transition of the stress field from the far field, in the plane-stress state, to the near crack-front field, dominated by the plane-strain state, is explained by the iso-contours of effective stress and the plane-strain constraint parameter. At the plane near the free surface, the crack-front field is close to the plane-stress state provided that the applied load is high and the plastic zone size is relatively large. Additional aspects of the 3D fields at the crack front through the thickness are also analyzed. In particular, a linear relationship between the constraint parameter A 2 and the hydrostatic stress is found in the 3D crack-front fields. It is also found that unlike the two-dimensional case where the J at the crack tip is not affected by the T -stress, the J -integrals at the crack front in the 3D case vary with the applied far field T -stress.
Cosmogenic nuclide methods for measuring long-term rates of physical erosion and chemical weathering

Understanding the evolution of geochemical and geomorphic systems requires measurements of long-term rates of physical erosion and chemical weathering. Erosion and weathering rates have traditionally been estimated from measurements of sediment and solute fluxes in streams. However, modern sediment and solute fluxes are often decoupled from long-term rates of erosion and weathering, due to storage or re-mobilization of sediment and solutes upstream from the sampling point. Recently, cosmogenic nuclides such as 10Be and 26Al have become important new tools for measuring long-term rates of physical erosion and chemical weathering. Cosmogenic nuclides can be used to infer the total denudation flux (the sum of the rates of physical erosion and chemical weathering) in actively eroding terrain. Here we review recent work showing how this total denudation flux can be partitioned into its physical and chemical components, using the enrichment of insoluble tracers (such as Zr) in regolith relative to parent rock. By combining cosmogenic nuclide measurements with the bulk elemental composition of rock and soil, geochemists can measure rates of physical erosion and chemical weathering over 1000- to 10,000-year time scales.
Modeling heterogeneous media with microstructures of different scales

The objective of this paper is to extend the framework of the continuum theory so that it can capture the properties that are embedded in the microstructure or nanostructure and still keep its simplicity and efficiency. The model thus developed is capable of accounting for local deformation of microstructures in solids especially their micro- (local) inertia effect. The essence underlying this approach is the introduction of a set of bridging functions that relate the local deformation of microstructures to the macrokinematic variables. Once the solution of the macroscopically homogeneous continuum is obtained, the solutions in the microstructures are obtained through the use of these bridging functions. Propagation of waves of different wavelengths is considered and the dispersion curve is used to evaluate the accuracy of the model. The model is also employed to study wave reflection and transmission at the boundary of two media with microstructures of very different scales.
Current immunosuppressive agents: efficacy, side effects, and utilization

Advances in immunosuppressive therapy over the past decade have led to dramatic improvements in graft survival. With the development of new agents, the focus of the transplant community is to establish regimens that maintain excellent graft survival rates but with fewer toxicities including infection, nephrotoxicity, malignancy, and cosmetic effects. Examples include the use of steroid-free protocols and calcineurin avoidance regimens, which are currently being studied by NAPRTCS. The ultimate goal of transplant immunosuppressive therapy is the induction of tolerance. As we learn more about immune function from basic and clinical research, tolerance to allografts seems a more reachable goal.
The first few hours off a respirator.

Fourteen patients receiving prolonged assisted ventilation were studied during their first trial period off the respirator. To avoid artifacts due to valves, mouthpieces, and noseclips, tidal volume off the respirator was measured continuously by electromagnetic sensors which detected changes in the anterior and posterior diameter of the rib cage and abdomen. Within five minutes of withdrawal from the respirator tidal volume fell, often to surprisingly low values, and respiratory frequency rose. Mean ventilation did not change. The changes in tidal volume, respiratory frequency, and heart rate did not indicate the changes which were occurring in the arterial blood gas levels. Furthermore, the magnitude of the changes in the breathing pattern did not predict whether or not the trial off the respirator would be successful. The changes in tidal volume, respiratory frequency, heart rate and the blood gas values did not correlate well with the subjective sensation of dyspnea.
Requirement for Serratia marcescens Cytolysin in a Murine Model of Hemorrhagic Pneumonia

Serratia marcescens, a member of the carbapenem-resistant Enterobacteriaceae, is an important emerging pathogen that causes a wide variety of nosocomial infections, spreads rapidly within hospitals, and has a systemic mortality rate of ≤41%. Despite multiple clinical descriptions of S. marcescens nosocomial pneumonia, little is known regarding the mechanisms of bacterial pathogenesis and the host immune response. To address this gap, we developed an oropharyngeal aspiration model of lethal and sublethal S. marcescens pneumonia in BALB/c mice and extensively characterized the latter. Lethal challenge (>4.0 × 106 CFU) was characterized by fulminate hemorrhagic pneumonia with rapid loss of lung function and death. Mice challenged with a sublethal dose (<2.0 × 106 CFU) rapidly lost weight, had diminished lung compliance, experienced lung hemorrhage, and responded to the infection with extensive neutrophil infiltration and histopathological changes in tissue architecture. Neutrophil extracellular trap formation and the expression of inflammatory cytokines occurred early after infection. Mice depleted of neutrophils were exquisitely susceptible to an otherwise nonlethal inoculum, thereby demonstrating the requirement for neutrophils in host protection. Mutation of the genes encoding the cytolysin ShlA and its transporter ShlB resulted in attenuated S. marcescens strains that failed to cause profound weight loss, extended illness, hemorrhage, and prolonged lung pathology in mice. This study describes a model of S. marcescens pneumonia that mimics known clinical features of human illness, identifies neutrophils and the toxin ShlA as a key factors important for defense and infection, respectively, and provides a solid foundation for future studies of novel therapeutics for this important opportunistic pathogen.
Engineering, Liberal Arts, and Technological Literacy in Higher Education

A small private liberal arts college with engineering, is experimenting with a new undergraduate paradigm for integrating the arts, humanities, and sciences with modern technology and engineering in a way that will enhance student's technological literacy for the 21st century. Union College brings together faculty from engineering and the liberal arts so that students graduate with an understanding beyond that provided by a traditional disciplinary major.
The total synthesis of allamandin

Abstract The first synthesis of (±)-allamandin is accomplished as a result of the successful one step conversion of plumericin.
Stress and metabolic control in diabetes mellitus: Methodological issues and an illustrative analysis

Rationale: The purpose of this article was twofold: a) to review studies of stress and glycemic control in diabetes, and b) to present a data analysis that illustrates the complexities of investigating stress in relation to blood glucose. The literature review emphasized human studies and the strengths and weaknesses of alternative designs. Special consideration was given to longitudinal investigations, and an analysis of data from the Diabetes Control and Complications Trial (DCCT) was presented to exemplify this approach. Nine individuals with Type 1 diabetes who participated in this project at the University of Iowa were studied over a period of 2 years. Stress was multiply measured (Life Experiences Survey, Hassles Scale, Perceived Stress Scale) as was blood glucose control (daily reflectance meter readings; monthly HbA1c). Within-subject time-series analyses and a combined longitudinal/cross-sectional model were used to analyze data. Two of the nine subjects manifested significant correlations between stress and HbA1c, and six subjects exhibited significant associations between stress and daily level or variability of glucose readings. The latter correlations varied in sign and appeared to cluster around specific individuals rather than a particular measure of stress or blood glucose. Conclusion: While the subjects may not represent the full spectrum of individuals with Type 1 diabetes, results were consistent with earlier longitudinal research in suggesting that the strength and direction of the relationship between stress and blood glucose control varies considerably between individuals.
Effects of the Nitric Oxide Donor Sodium Nitroprusside on Intracellular pH and Contraction in Hypertrophied Myocytes

Background We compared the effects of the nitric oxide donor sodium nitroprusside (SNP) on intracellular pH (pHi), intracellular calcium concentration ([Ca2+]i) transients, and cell contraction in hypertrophied adult ventricular myocytes from aortic-banded rats and age-matched controls. Methods and Results pHi was measured in individual myocytes with SNARF-1, and [Ca2+]i transients were measured with indo 1 simultaneously with cell motion. Experiments were performed at 37°C in myocytes paced at 0.5 Hz in HEPES-buffered solution (extracellular pH=7.40). At baseline, calibrated pHi, diastolic and systolic [Ca2+]i values, and the amplitude of cell contraction were similar in hypertrophied and control myocytes. Exposure of the control myocytes to 10−6 mol/L SNP caused a decrease in the amplitude of cell contraction (72±7% of baseline, P<.05) that was associated with a decrease in pHi (−0.10±0.03 U, P<.05) with no change in peak systolic [Ca2+]i. In contrast, in the hypertrophied myocytes exposure to SNP did n...
Statistical dynamics of boundary motion

Abstract Motion of a domain wall between two magnetic domains of the Ising model induced by an external magnetic field is investigated by means of the technique of statistical dynamics developed by the author. It is assumed that each magnetic spin has a finite kinetic probability for changing its sign per unit time and that the spin system is in thermal contact with a heat bath. The path probability g for the change of state of the system for a short time interval is written in terms of a set of path parameters using the point approximation (the Bragg-Williams approximation) of the cluster-variation method, and then g is maximized with respect to the path parameters to determine the most probable change of state. When the profile of the domain wall is smooth, it is approximated by a continuous function of the distance; the change of the profile is then written as a differential equation. In the steady state when the domain wall is displaced parallel to itself, the differential equation takes the form of an eigenvalue equation with the velocity of the wall v playing the role of the eigenvalue. This eigenvalue equation is nonlinear, but it can be linearized when the applied magnetic field is weak and v is small. The equation for this case is solved and v is expressed in terms of known quantities. The technique developed in this paper is applicable to more realistic models of domain boundaries and also can be combined with better approximations of the cluster-variation method.
Damage in carbon fibre composites due to repetitive low-velocity impact loads

The effect of repetitive impacting with increasing impact energy on unsupported thermoset matrix and thermoplastic matrix carbon fibre laminates was studied. In the case of the thermoset laminates, there were two abrupt losses in stiffness, the first corresponding to through-the-thickness damage and the second to the damage extending to the specimen edges. The thermoplastic matrix laminates exhibited a continuous decline in stiffness but again the damage sequence was through-the-thickness followed by extension to the specimen edges. Static bend testing of these composites resulted in the same type and extent of damage as was observed for impact loading. The effect of increasing the unsupported area and laminate thickness were investigated. Impacting with increasing impact energy was compared to repetitive impacting at a constant impact energy.
TEST OF AN ASSUMPTION IN COGNITIVE CONSISTENCY THEORIES

Research was conducted to determine whether ratings of source trustworthiness are more strongly related to attitudinal congruency between the source's expected position and S's own, the shorter the...
Effect of α-Lactalbumin on Aerosol-OT Phase Structures in Oil/Water Mixtures

The ability of water-soluble, globular proteins to tune surfactant/oil/water self-assemblies has potential for the formation of biocompatible microemulsions and also plays a role in protein function at biological interfaces. In this work, we examined the effect of the protein alpha-lactalbumin on Aerosol-OT (AOT) phase structures in equivolume mixtures of oil and 0.1 M brine. In this pseudo-ternary system, surfactants are free to move to either oil or water phase to adopt phase structures close to the spontaneous curvature of the surfactants. Using small-angle X-ray scattering, we observed that addition of this protein changed the spontaneous curvature of the surfactant monolayer substantially. In the absence of protein, AOT adopted a negative spontaneous curvature to form spherical w/o microemulsion droplets. When less than 1 wt % of alpha-lactalbumin was added into the system, the w/o droplets became nonspherical and larger in volume, corresponding to an increase in water uptake into the droplets. As the protein-to-surfactant ratio increased, protein, surfactant, and oil increasingly partitioned toward the aqueous phase. There the protein triggered the formation of o/w microemulsions with a positive spontaneous curvature. These protein-containing structures exhibited significant interparticle attraction. We also compared the influence of two oil types, isooctane and cyclohexane, on the protein/surfactant interactions. We propose that the more negative natural curvature of the AOT/cyclohexane monolayer in the absence of protein prevented protein incorporation within organic phase structures and consequently pushed the system self-assembly toward aqueous aggregate formation.
Influence of lithological heterogeneity, mechanical anisotropy, and magmatism on the rheology of an arc, North Cascades, Washington

Abstract Many aspects of crustal dynamics are dependent on changes in rheology and strength with depth in the lithosphere. Several of the controlling factors for rheology are difficult to study experimentally, particularly lithological heterogeneity, mechanical anisotropy, and magmatism, and we focus on these in a study of the deformation patterns in a thick crustal section (∼5- to 40-km paleodepth) through the Cretaceous Cascades core of the NW Cordillera. This magmatic arc consists of metamorphosed oceanic and arc terranes intruded by magmatic bodies ranging from Heterogeneous brittle deformation marked by serpentinite melange characterizes the shallowest part of the crustal section, and the remainder of the section is characterized by heterogeneous, fold-dominated ductile deformation. Early tight to isoclinal recumbent folds and associated axial-planar fabrics are refolded by one or more cycles of nearly coaxial, open to isoclinal, upright to overturned folds. Layering played a mechanically active role during folding at all levels, as indicated by cleavage refraction, boudinaged layers, and kinematic indicators that record fold-related shear. Ductile deformation intensifies in the narrow structural aureoles of plutons, and SW-directed, reverse shear was partitioned into some of the aureoles. The poor strain memory of these magmatic bodies makes it difficult to determine if deformation was focused in the pluton magma chambers before they reached the solidus, as commonly predicted. All of the plutons have magmatic foliations that at least in part reflect regional strains, and these foliations are strong in the deeper plutons. The thinner sheets acted as competent bodies during folding and boudinage, after they reached the solidus, but generally did not cause marked strain gradients in their hosts. A relative strength profile constructed for the Cascades crustal section shows an overall decrease in strength with depth for the ductile part of the arc that fits idealized strength profiles. However, in more detail relative strengths are markedly variable. Units were able to accumulate large ductile strains, but even small variations in the physical properties of interlayered rock types exerted a strong influence on deformation patterns throughout the mid- to deep-crustal part of the profile. This profile thus emphasizes the complex vertical rheological stratification of arcs at the crustal to thin section scale, and should be applicable to many other magmatic arcs.
On the use of diffusion maps for image fusion

This work considers the problem of combining high dimensional data acquired from multiple sensors for the purpose of detection and classification. The sampled data are viewed as a geometric object living in a highdimensional space. Through an appropriate, distance preserving projection, those data are reduced to a lowdimensional space. In this reduced space it is shown that different physics of the sampled phenomena reside on different portions of the resulting "manifold" allowing for classification. Moreover, we show that data acquired from multiple sources collected from the same underlying physical phenomenon can be readily combined in the low-dimensional space i.e. fused. The process is demonstrated on maritime imagery collected from a visible-band camera.
Using Concept Maps to Assess Student Learning in the Science Classroom: Must Different Methods Compete?.

This yearlong study was implemented in seventh-grade life science classes with the stu- dents' regular teacher serving as teacher/researcher. In the study, a method of scoring concept maps was developed to assess knowledge and comprehension levels of science achievement. By linking scoring of concept maps to instructional objectives, scores were based upon the correctness of propositions. High cor- relations between the concept map scores and unit multiple choice tests provided strong evidence of the content validity of the map scores. Similarly, correlations between map scores and state criterion-refer- enced and national norm-referenced standardized tests were indicators of high concurrent validity. The ap- proach to concept map scoring in the study represents a distinct departure from traditional methods that focus on characteristics such as hierarchy and branching. A large body of research has demonstrated the utility of such methods in the assessment of higher-level learning outcomes. The results of the study sug- gest that a concept map might be used in assessing declarative and procedural knowledge, both of which have a place in the science classroom. One important implication of these results is that science curricu- lum and its corresponding assessment need not be dichotomized into knowledge/comprehension versus higher-order outcomes. © 1998 John Wiley & Sons, Inc. J Res Sci Teach 35: 1103-1127, 1998.
Initiation and engagement in chronic disease management care for substance dependence.

Abstract Background Substance dependence treatment is often episodic and not well coordinated with healthcare for common comorbidities. Chronic disease/care management (CDM), longitudinal, patient-centered care delivered by multidisciplinary health professionals, may be well suited to treat substance dependence (SD). Objective To examine initiation and engagement with CDM care for SD located in a primary medical setting. Methods We prospectively studied substance dependent participants enrolled in a trial of CDM addiction care. Primary study outcomes, based upon Washington Circle performance measures, were 14-day initiation of CDM care and 30-day engagement with CDM care. Factors associated with these outcomes were determined using multivariable logistic regression models. We also estimated the proportion of participants who eventually attended at least two visits and four visits by the end of the study (Kaplan–Meier method). Results Of 282 participants, approximately half of the cohort (45%, 95% Confidence Interval [CI] 39–51%) met criteria for 14-day initiation and 23% (95% CI 18–28%) for 30-day engagement with CDM care. Most participants attended two or more (81%, 95% CI 76–85%) and four or more CDM visits (62%, 95% CI 56–68%). Major depressive episode (AOR 2.60, 95% CI 1.39, 4.87) was associated with higher odds of 14-day initiation; younger age, female sex, and higher alcohol addiction severity were associated with lower odds of 30-day engagement with CDM care. Conclusion : People with SD appear to be willing to initiate and engage with CDM care in a primary medical care setting. CDM care has the potential to improve the quality of care for people with addictions.
The pairwise-correlated generalized valence bond model of electronic structure. V. A multiconfiguration overlap approximation for gvb pair energies

A multiconfiguration overlap approximation for GVB pair correlation energies is developed and applied to the ground states of H2 and LiH. The exploratory studies presented indicate that if we explicitly include the effects from three low-lying excitations beyond the GVB wave function, we obtain an overlap approximation for GVB molecular pair correlation energies that is accurate to 0.001 hartree (0.5 kcal/mole) for all internuclear distances from 0 to ∞, and gives the proper asymptotic form for van der Waals interactions.
Stability of solutions of differential equations with retarded arguments

A criterion is given for the stability of trivial solutions of the differential equations with the variable coefficients and variable delays. The derivation is based on Lyapunov's direct method.
Interaction of low-energy electrons with surface lattice vibrations

Abstract In the present article, we examine the interaction of low-energy electrons near the crystal surface with lattice vibrations of the surface region. Our primary attention is devoted to the use of the inelastic scattering of low-energy electrons to elucidate the nature of this interaction, and to obtain information about the nature of atomic vibrations in and near the surface. We review both the theoretical and the experimental literature in this area, within the framework of a discussion of the concepts which are required to interpret the data. We also present a discussion of a number of closely related topics, such as the origin of the image potential in ionic crystals, the properties of the surface polaron, the surface dynamic effective charge and its possible relation to the phenomenon of surface reconstruction, and the scattering by electronic excitations of low-energy electrons incident on the surface.
Groups with a Steinberg character

Let G be a finite group and p a rational prime. If G is a simple Lie type group of characteristic p then G has the following property. G has an absolutely irreducible character )~ whose degree is the order of a p-Sylow subgroup of G, and all other characters are in the principal p-block, Bo (P). (Z is called the Steinberg character. See [4, 5, 9] and [12].) For simple groups G, this property seems to hold only if G has Lie type of characteristic p. The most general conjecture that can be made from this observation, namely that the above property about the characters of G forces G to be of Lie type at characteristic p, seems too difficult at present. In fact to prove anything in this direction, I have had to make arithemtical assumptions about G as well as assumptions about a subgroup which ultimately corresponds to the normalizer of a torus. In Section 4 1 will indicate why such assumptions may be inevitable.
Benzocyclobutenes as crosslinking agents in synthetic polyolefins

4-Allylbenzocyclobutene was synthesized and copolymerized with 1-hexene and a non-conjugated diene, and the resulting terpolymer was cured thermally, under pressure, in the presence of carbon black. Mechanical properties of the crosslinked polymer containing allylbenzocyclobutene with two different dienes (5-methyl-1,4-hexadiene and 7-methyl-1,6-octadiene) were studied and are presented. Similar properties of a standard sulfurcured polymer composed of 1-hexene and the two dienes were measured for comparison.
Coronary Artery Spasm Induced by Stent Implantation: Studies in a Swine Model

Mechanical stimulation is a known cause of arterial spasm. Since stent implantation in the coronary arteries imparts mechanical trauma, we investigated, in an animal model that simulates human coronary anatomy and physiology, the frequency of occurrence and factors that influence the development of spasm. In 28 Hanford miniature swine, 9 of which were atherosclerotic and 19 of which were nonatherosclerotic, spasm occurred in 15 (54%). Stent-induced spasm directly caused the death of one animal and was implicated in the death of two others. Factors that significantly contributed to coronary spasm were the stent: artery ratio (more spasm with oversized stents) and the size of the artery (more spasm with smaller arteries). There was a trend toward more spasm in atherosclerotic arteries. Spasm occurred despite the use of antispasmodic agents before, during, and after the scenting procedure. Our data suggest that coronary artery spasm may be an important clinical accompaniment to stent implantation in man and may be minimized by the judicious selection of stent size to avoid overdistention of the artery and the avoidance of stent placement in smaller arteries. (J Interven Cardiol 1993; 6:149–155)
Cobalt(III) complexes of stereospecific linear NSNN tetradentate ligands. Synthesis and characterization of ternary amino acid complexes containing tetradentate ligands with terminal amine donors

Abstract The preparation and characterization of cis-β-[Co(gee)(gly)]+ (geeHN-{2-[(2-aminoethyl)thio]ethyl}-2-aminoacetamide) and cis-β-[Co(ege)(AA)]+ (egeHN-(2-aminoethyl)-2-[(2-aminoethyl)thio]acetamide; AAgly, L -ala, L -leu, L -ile) complexes as PF6− or mixed Cl−/PF6− salts are described. 1H and 13C NMR spectra of the new cobalt complexes demonstrate that only one geometrical isomer (with respect to the bidentate chelate) is obtained with very high stereoselectivity. X-ray structural studies revealed that orientation of the amino acidato chelate is the β1 configuration; that is, the isomer with the carboxylate donor of the amino acid coordinated trans to the amido function to the tetradentate backbone ligand. β1-[Co(gee)(gly)]PF6·H2O (I) crystallized in the monoclinic space group P21/a with a=11.748(2), b=11.810(2), c=12.341(3) A, β=101.43(2)° and Z=4 and was refined to R=0.042. β1-[Co(ege)(gly)]PF6 (II) crystallized in the monoclinic space group P21/n with a=11.467(2), b=8.173(1), c=17.421(3) A, β=106.69(2)° and Z=4 and was refined to R=0.052. The complexes, β-[Co(L)Cl2] (Lgee or ege), were found to be convenient precursors for the hydrolysis of the peptide bond of glygly to give β1-[Co(L)(gly)]+ under mild conditions.
Methods for decreasing the statistical variance of stereological estimates.

Three methods are described for decreasing the statistical variance of stereological estimates. Method 1 uses profile boundaries and surface densities of nuclear membranes, measured in thin sections, to estimate the mean diameter, surface area, and numerical density of spherical and nonspherical nuclei. For the guinea pig pancreas (number(m) = 4), the standard deviations (s.d.) as a percent of the mean for the estimates of the diameters of the exocrine, duct, and endothelial cell nuclei were 1.5%, 3.3% and 1.4%. The estimate for the mean diameter of exocrine nuclei (6.4 +/- 0.1 micron) was based on a spherical model, whereas the estimates for the diameters of the nonspherical (and nonconvex) nuclei of the duct (6.4 +/- 0.2 micron) and endothelial (6.7 +/- 0.1 micron) cells were calculated from the numerical density of the exocrine cells and the relative frequencies of the three cell types (determined from serial reconstructions). In an average cubic centimeter, there were 6.17 X 10(8) +/- 0.32 X 10(8) (s.d. 5.1% of mean) exocrine cells, 1.64 X 10(8) +/- 0.18 X 10(8) (10.9%) duct cells, and 0.803 X 10(8) +/- 0.13 X 10(8) (16.6%) endothelial cells. In contrast to method 1, conventional stereological approaches were found to have standard deviations two- to eightfold larger. Method 2 uses a mean nuclear surface area and a ratio of surface densities to estimate the surface area of a membrane compartment in an average cell. A s.d. equal to 6.5% of the mean was found for the surface area of the outer mitochondrial membrane in an average exocrine cell (672 +/- 43.6 micron 2), which represented an almost fourfold reduction in the s.d. compared with an earlier estimate (Bolender, 1974). Method 3 relates the surface area of a membrane compartment to a standard number of cells. Referenced to 10(6) cells, for example, the surface area of the inner nuclear membrane of endothelial cells had a s.d. equal to 2.9% of the mean, whereas the surface density of the same membrane compartment-referenced to a cm3 of cells-had a s.d. at 19.1% of the mean. In this case, method 3 produced almost a sevenfold reduction in the standard deviation. Similar results were found for exocrine and duct cells. The results of the study indicate that the standard deviation of a stereological estimate can be reduced to a minimum by using a mean nuclear profile boundary to generate an estimate for a nuclear numerical density, which, in turn, can be combined with a surface density to obtain average cell information.