cssi/SciSciGPT-SciSciNet huggingface dataset:
Coadsorption of ethylene and hydrogen on (2 × 1) Pt(110): Observation of a weakly bound form of ethylene

Abstract Previous work has shown that the hydrogenation of ethylene on a hydrogen covered platinum surface is significantly different than ethylene hydrogenation on clean platinum. However, it is unclear why the difference occurs. In this paper, the coadsorption of ethylene and hydrogen on (2 × 1) Pt(110) was examined using mainly EELS. It is found that adsorbed hydrogen substantially modifies the adsorption of ethylene. While ethylene adsorption on a clean 93 K (2 × 1) Pt(110) sample results in the production of a mixture of di-σ and π-bound ethylene, little di-σ ethylene is observed if the sample is exposed to 100 L of H2 before the surface is exposed to ethylene. Instead, a new form of adsorbed ethylene is seen. The new form of adsorbed ethylene has a vibrational spectrum very similar to that of gas phase ethylene suggesting it is weakly bound. There is also a new ethane desorption peak at 180 K when ethylene is adsorbed onto a hydrogen saturated (2 × 1) Pt(110) surface. By comparison, the new form of ethylene and the 180 K ethane desorption peak are not observed when ethylene is adsorbed onto a clean (2 × 1) Pt(110) surface, then hydrogen is added to the layer. Nevertheless, there is an inhibition of ethylene decomposition and an enhancement of the ethylene and ethane desorption when hydrogen is added to a surface which was partially covered with ethylene. These results suggest that hydrogen acts as a site blocker on the (2 × 1) Pt(110) surface to prevent di-σ ethylene formation, and to inhibit ethylene decomposition on the (2 × 1) Pt(110) surface.
N‐acetylglucosamine and adenosine derivatized surfaces for cell culture: 3T3 fibroblast and chicken hepatocyte response

3T3 fibroblasts and primary chicken hepatocytes were cultured on derivatized polystyrene surfaces to examine the effect of cell-specific ligands on cellular morphology and growth. Surfaces were prepared by derivatizing chloromethylated polystyrene with N-acetylglucosamine (GlcNAc; recognized by the chicken asialoglycoprotein receptor) and adenosine (not recognized by adult hepatocytes). These surfaces were compared with tissue culture polystyrene (TCPS), acid-cleaned glass, and the unmodified chloromethylated polystyrene. The spreading, cytoskeletal structure and growth of the fibroblasts following attachment to these surfaces were examined. The extent of attachment, total protein levels, and DNA contents for surfaces-attached chicken hepatocytes were also measured. Fibroblast spreading was greatest on polymer surfaces derivatized with GlcNAc, whereas cytoskeletal structure and growth rate were independent of surface chemistry. Although chicken hepatocytes attached most efficiently to the GlcNAc derivatized polymer, the total protein and DNA levels of the surface-attached cells were not affected. In anticipation of the application of these polymers for cell culture and hybrid artificial organ design, the GlcNAc-derivatized polystryrene was fabricated into porous microcarriers. Fibroblasts grew avidly on the microcarriers, whereas chicken hepactocytes adhered well to the formed large aggregates arounds the microcarriers.
Effects of organic matter removal, soil compaction, and vegetation control on Collembolan populations

Abstract Collembola can be among the most numerous meso-invertebrates in the forest floor and, through their interaction with primary decomposers in the decomposition food web, may affect litter decomposition and consequently site productivity. This study was conducted to determine whether Collembolan abundance could be impacted by organic matter removal, compaction, and vegetation control on a loblolly pine (Pinus taeda L.) plantation. Monthly soil and litter samples were taken over 2 years and the fauna extracted from them using modified Tulgren funnels. Organic matter removal and vegetation control generally caused a significant decrease in Collembolan populations, while compaction did not significantly affect Collembolan populations. These results indicate that habitat was the primary influence on population abundance in this experiment, possibly via its influence on desiccation. Sensitivity of collembolan populations to habitat changes caused by organic matter removal indicates a potential effect on long-term site productivity.
Corticosterone mitigates the stress response in an animal model of PTSD

Activation of glucocorticoid receptor signaling in the stress response to traumatic events has been implicated in the pathogenesis of stress-associated psychiatric disorders such as post-traumatic stress disorder (PTSD). Elevated startle response and hyperarousal are hallmarks of PTSD, and are generally considered to evince fear (DSM V). To further examine the efficacy of corticosterone in treating hyperarousal and elevated fear, the present study utilized a learned helplessness stress model in which rats are restrained and subjected to tail shock for three days. These stressed rats develop a delayed long-lasting exaggeration of the acoustic startle response (ASR) and retarded body weight growth, similar to symptoms of PTSD patients (Myers et al., 2005; Speed et al., 1989). We demonstrate that both pre-stress and post-stress administration of corticosterone (3 mg/kg/day) mitigates a subsequent exaggeration of the ASR measured 14 days after cessation of the stress protocol. Furthermore, the mitigating efficacy of pre-stress administration of corticosterone (3 mg/kg/day for three days) appeared to last significantly longer, up to 21 days after the cessation of the stress protocol, in comparison to that of post-stress administration of corticosterone. However, pre-stress administration of corticosterone at 0.3 mg/kg/day for three days did not mitigate stress-induced exaggeration of the ASR measured at both 14 and 21 days after the cessation of the stress protocol. In addition, pre-stress administration of corticosterone (3 mg/kg/day for three days) mitigates the retardation of body weight growth otherwise resulting from the stress protocol. Congruently, co-administration of the corticosterone antagonist RU486 (40 mg/kg/day for three days) with corticosterone (3 mg/kg/day) prior to stress diminished the mitigating efficacy of the exogenous corticosterone on exaggerated ASR and stress-retarded body weight. The relative efficacy of pre versus post administration of corticosterone and high versus low dose of corticosterone on stress-induced exaggeration of innate fear response and stress-retarded body weight growth indicate that exogenous corticosterone administration within an appropriate time window and dosage are efficacious in diminishing traumatic stress induced pathophysiological processes. Clinical implications associated with the efficacy of prophylactic and therapeutic corticosterone therapy for mitigating symptoms of PTSD are discussed, particularly in relation to diminishing hyperarousal and exaggerated innate fear response.
Sensitivity analysis of energy management strategies for hydraulic hybrid vehicles

This paper presents a study of how different methods for designing energy management strategies (EMS) are affected by variations in drive cycle and system parameters. Specifically a rule-based strategy extracted from analysis of dynamic programming results over the Federal Urban Drive Cycle and a model predicative controller are considered. These strategies were validated on a hydraulic hybrid powertrain testbed. The hydraulic hybrid powertrain utilizes a high pressure accumulator for energy storage which has superior power density than conventional battery technology. This makes fluid power attractive for urban driving applications in which there are frequent starts and stops. Through a simulation study we will demonstrate the need to carefully consider the application and confidence one has in knowledge of the drive cycle and system model when choosing an EMS design method.Copyright © 2012 by ASME
Modeling transit bus fuel consumption on the basis of cycle properties.

ABSTRACT A method exists to predict heavy-duty vehicle fuel economy and emissions over an “unseen” cycle or during unseen on-road activity on the basis of fuel consumption and emissions data from measured chassis dynamometer test cycles and properties (statistical parameters) of those cycles. No regression is required for the method, which relies solely on the linear association of vehicle performance with cycle properties. This method has been advanced and examined using previously published heavy-duty truck data gathered using the West Virginia University heavy-duty chassis dynamometer with the trucks exercised over limited test cycles. In this study, data were available from a Washington Metropolitan Area Transit Authority emission testing program conducted in 2006. Chassis dynamometer data from two conventional diesel buses, two compressed natural gas buses, and one hybrid diesel bus were evaluated using an expanded driving cycle set of 16 or 17 different driving cycles. Cycle properties and vehicle f...
Use of risk measures in design and licensing of future reactors

Use of information and insights from probabilistic risk assessments (PRAs) in nuclear reactor safety applications has been increasing by the nuclear industry and the regulators, both domestically and internationally. This is a desirable trend, as PRAs have demonstrated capability to improve safety and operational flexibility beyond that provided through deterministic approaches alone. But there can be potential pitfalls. The limitations of risk assessment technology can be lost through approaches that rely heavily on quantitative PRA results (referred to as risk measures in this paper), because of the unambiguous but potentially misleading message that can be delivered by risk-based numbers. This is particularly true for future reactors, where PRAs are used during the design and licensing processes. For these applications, it is important to ensure that the actual, de facto, or even perceived use of risk measures in the context of either regulatory or design acceptance criteria is avoided. While the issues discussed here can have a significant influence on design certification or combined license applications for future reactors, they can also have secondary impacts on currently operating reactors.
Microwave extraction in analytical chemistry of pollutants: Chlorinated benzenes†

The microwave energy produced in a cavity of the magnetron was used to extract chlorinated benzenes from water samples. This dynamic extraction method employs a stream of helium. Results were compared with those obtained by liquid-liquid and the large volume extractions. The microwave extraction provides results that are comparable with those obtained using other techniques, while offering the advantages of speed. The preconcentration factors are approx. 1000 and corresponding detection limits for 1 liter of water are in the pg/L range, when determination of individual polychlorinated benzene congeners is performed using HRGC/MS/ selected ion monitoring. © 1995 John Wiley & Sons, Inc.
Evidence for droplet reorientation and interfacial charges in a polymer-dispersed liquid-crystal cell.

We observe a new feature ( plateau), sandwiched between two exponentially decaying components, in the switching response of a polymer-dispersed liquid-crystal (PDLC) cell. Upon application of square-wave electrical pulses, the cell response exhibits a complex decay whose characteristics are significantly different within and outside the applied field. We interpret these results in terms of reorientation dynamics of nonspherical droplets in the PDLC. Irradiation of the PDLC with gamma rays induces significant changes in the cell response in a manner that is consistent with redistribution of charges at the liquid-crystal--polymer interface in the PDLC.
Direct laser trapping for measuring the behavior of transfused erythrocytes in a sickle cell anemia patient

Using a laser trap, we have studied the properties of erythrocytes from a sickle cell anemia patient (SCA) after receiving an intravenous blood transfusion, and a normal adult individual carrying normal adult hemoglobin. The hemoglobin type and quantitation assessment was carried out by high performance liquid chromatography (HPLC). We conducted an analysis of the size distributions of the cells. By targeting those erythrocytes in the overlapping regions of size distributions, we have investigated their properties when the cells are trapped and released. The efficacy of the transfusion treatment is also studied by comparing the relative changes in deformation and the relaxation-time of the cells in the two samples.
Nonsingular Lagrangians for two-dimensional black holes.

We introduce a large class of modifications of the standard Lagrangian for two-dimensional dilaton gravity, whose general solutions are nonsingular black holes. A subclass of these Lagrangians have extremal solutions which are nonsingular analogues of the extremal Reissner-Nordstr\"om spacetime. It is possible that quantum deformations of these extremal solutions are the end point of Hawking evaporation when the models are coupled to matter, and that the resulting evolution may be studied entirely within the framework of the semiclassical approximation. Numerical work to verify this conjecture is in progress. We point out however that the nonextremal solutions always contain Cauchy horizons, and may be sensitive to small perturbations.
How do polymers prolong circulation time of liposomes

AbstractProtective effect of poly(ethylene glycol) and some other polymers on liposomes is considered in terms of statistical behavior of macromolecules in solution. According to the mechanism proposed, liposome-grafted chains of flexible and hydrophilic polymers form dense “conformational clouds” preventing other macromolecules from the surrounding solution from interaction with the liposome surface even at low concentration of protecting polymer. The scale of protective effect is interpreted as the balance between the energy of hydrophobic anchor interaction with the membrane core and the energy of polymer chain free motion in solution. Experimental evidences are presented for the importance of protecting polymer flexibility in preventing liposome opsonization, and possible further theoretical applications of the suggested model are discussed. The possibility of using protecting polymers other than poly(ethylene glycol) is analyzed, and examples of such polymers are given basing on polymer-coated liposo...
Discriminators of mouse bladder response to intravesical Bacillus Calmette-Guerin (BCG).

Intravesical Bacillus Calmette-Guerin (BCG) is an effective treatment for bladder superficial carcinoma and it is being tested in interstitial cystitis patients, but its precise mechanism of action remains poorly understood. It is not clear whether BCG induces the release of a unique set of cytokines apart from its pro-inflammatory effects. Therefore, we quantified bladder inflammatory responses and alterations in urinary cytokine protein induced by intravesical BCG and compared the results to non-specific pro-inflammatory stimuli (LPS and TNF-α). We went further to determine whether BCG treatment alters cytokine gene expression in the urinary bladder. C57BL/6 female mice received four weekly instillations of BCG, LPS, or TNF-α. Morphometric analyses were conducted in bladders isolated from all groups and urine was collected for multiplex analysis of 18 cytokines. In addition, chromatin immune precipitation combined with real-time polymerase chain reaction assay (CHIP/Q-PCR) was used to test whether intravesical BCG would alter bladder cytokine gene expression. Acute BCG instillation induced edema which was progressively replaced by an inflammatory infiltrate, composed primarily of neutrophils, in response to weekly administrations. Our morphological analysis suggests that these polymorphonuclear neutrophils are of prime importance for the bladder responses to BCG. Overall, the inflammation induced by BCG was higher than LPS or TNF-α treatment but the major difference observed was the unique granuloma formation in response to BCG. Among the cytokines measured, this study highlighted the importance of IL-1β, IL-2, IL-3, IL-4, IL-6, IL-10, IL-17, GM-CSF, KC, and Rantes as discriminators between generalized inflammation and BCG-specific inflammatory responses. CHIP/Q-PCR indicates that acute BCG instillation induced an up-regulation of IL-17A, IL-17B, and IL-17RA, whereas chronic BCG induced IL-17B, IL-17RA, and IL-17RB. To the best of our knowledge, the present work is the first to report that BCG induces an increase in the IL-17 family genes. In addition, BCG induces a unique type of persisting bladder inflammation different from TNF-α, LPS, and, most likely, other classical pro-inflammatory stimuli.
Tuning the Hemolytic and Antibacterial Activities of Amphiphilic Polynorbornene Derivatives

Amphiphilic cationic polynorbornene derivatives, soluble in water, were prepared from modular norbornene monomers, with a wide range of molecular weights (Mn = 1600−137 500 g/mol) and narrow polydispersities (PDI = 1.1−1.3). The antibacterial activity determined by growth inhibition assays and the hemolytic activity against human red blood cells were measured and compared to determine the selectivity of the polymers for bacterial over mammalian cells. The effects of monomer repeat unit hydrophobicity and polymer molecular weight on antibacterial and hemolytic activities were determined. The hydrophobicity of the repeat unit was observed to have dramatic effects on antibacterial and hemolytic activities. Lipid membrane disruption activities of the polymers was confirmed by measuring polymer-induced dye leakage from large unilamellar vesicles. By tuning the overall hydrophobicity of the polymer through random copolymerizations of modular norbornene derivatives, highly selective, nonhemolytic antibacterial a...
Co3O4 nanocrystals coupled with O- and N-doped carbon nanoweb as a synergistic catalyst for hybrid Li-air batteries

Abstract Expensive Pt-based catalysts are usually required to achieve a high discharge voltage and long operation life for hybrid Li-air batteries. However, the cost of the catalysts needs to be lowered by either reducing the Pt loading in the catalysts or replacing Pt with less expensive catalysts. Here, we report the strong coupling of Co 3 O 4 nanocrystals with an O- and N-doped carbon nanoweb (ON-CNW) as a low-cost, highly-efficient catalyst for hybrid Li-air batteries with an alkaline catholyte. Co 3 O 4 /ON-CNW greatly reduces the discharge overpotential compared to ON-CNW and exhibits longer cycle life, which is even better than that of the best reported N-doped mesoporous carbon (0.016% decrease in efficiency per cycle for 130 cycles compared to 0.017% decrease per cycle for 100 cycles obtained with N-doped mesoporous carbon). Although Pt/C exhibits a slightly higher initial discharge voltage (3.02 V compared to 3.00 V for Co 3 O 4 /ON-CNW), the cycle life of Pt/C is 3 O 4 /ON-CNW as a viable, stable cathode for hybrid Li-air batteries.
Non-electrolyte probes of membrane structure in ADH-treated toad urinary bladder.

ALTHOUGH it is well known that antidiuretic hormone (ADH) increases the permeability of amphibian urinary bladders to water and small polar non-electrolytes such as urea and acetamide1,2, there is much uncertainty about the mechanisms involved. To gain further insight into the interaction of ADH with this membrane, we have studied the permeation of lipophilic molecules in the presence and absence of the hormone. It has long been recognised that permeability measurements may offer unique clues about the nature of biological membranes3,4.
Isothermal and Multithermal Analysis of Coronal Loops Observed with AIA

The coronal filters in the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory peak at different temperatures; the series covers the entire active region temperature range, making AIA ideal for multithermal analysis. Here, we analyze coronal loops from several active regions that have been observed by AIA. We have specifically targeted cool loops (or at least loops with a cool component) that were chosen in the 171 A channel of AIA, which has a peak response temperature of log T = 5.8. We wanted to determine if the loops could be described as isothermal or multithermal. We find that several of our 12 loops have narrow temperature distributions, which may be consistent with isothermal plasma; these can be modeled with a single flux tube. Other loops have intermediate-width temperature distributions, appear well-constrained, and should be multi-stranded. The remaining loops, however, have unrealistically broad differential emission measures. We find that this problem is the result of missing low-temperature lines in the AIA 131 A channel. If we repeat the analysis without the 131 A data, these loops also appear to be well-constrained and multi-stranded.
Winkler boundary conditions for three-point bending tests on 1D nanomaterials.

Bending tests with atomic force microscopes (AFM) is a common method for elasticity measurements on 1D nanomaterials. Interpretation of the force and deflection data is necessary to determine the Young's modulus of the tested material and has been done assuming either of two classic boundary conditions that represent two extreme possibilities for the rigidity of the sample–anchor interface. The elasticity results from the two boundary conditions differ by a factor of four. Furthermore, both boundary conditions ignore the effects of deflections in the anchors themselves. The Winkler model for beams on elastic foundations is developed here for three-point bending tests to provide a more realistic representation. Equations for computing sample elasticity are derived from two sets of boundary conditions for the Winkler model. Application of this model to interpret the measurement of mechanical stiffness of a silica nanowire at multiple points in a three-point bending is discussed. With the correct choice of boundary conditions, the Winkler model gives a better fit for the observed stiffness profile than the classical beam models while providing a result that differs from both by a factor of two and is comparable to the bulk elasticity.
Demography as the human story.

Demography has played a supporting role in the study of human history but relatively few demographers have chosen to view history broadly through a demographic lens. Demographers like Massimo Livi Bacci have made clear that while demographic analysis has considerable power in the study of history the study of long-term human change requires new demographic tools. Following the work by Livi Bacci the author studies Polynesian and particularly the Hawaiian islands to better understand the trajectory of population and social change in the early history of the islands their state before European contact and what drove their populations to follow divergent trajectories after contact. In his discussion of the islands and the broader parallels between other stories of contact around the world the author shows that Hawaii illustrates a range of historical questions that should be answered about early human populations and the challenges the experience of these populations poses for demographic theory. The author outlines an approach to the formal demography of prehistory and discusses its application to Hawaii and its potential for broader application and the demographic challenges that still remain.
Lattice-based access control models

Lattice-based access control models were developed in the early 1970s to deal with the confidentiality of military information. In the late 1970s and early 1980s, researchers applied these models to certain integrity concerns. Later, application of the models to the Chinese Wall policy, a confidentiality policy unique to the commercial sector, was demonstrated. A balanced perspective on lattice-based access control models is provided. Information flow policies, the military lattice, access control models, the Bell-LaPadula model, the Biba model and duality, and the Chinese Wall lattice are reviewed. The limitations of the models are identified. >
Joint space narrowing and Kellgren-Lawrence progression in knee osteoarthritis : an analytic literature synthesis

Summary Objective While the interpretation of cartilage findings on magnetic resonance imaging (MRI) evolves, plain radiography remains the standard method for assessing progression of knee osteoarthritis (OA). We sought to describe factors that explain variability in published estimates of radiographic progression in knee OA. Design We searched PubMed between January 1985 and October 2006 to identify studies that assessed radiographic progression using either joint space narrowing (JSN) or the Kellgren–Lawrence (K–L) scale. We extracted cohort characteristics [age, gender, and body mass index (BMI)] and technical and other study factors (radiographic approach, study design, OA-related cohort composition). We performed meta-regression analyses of the effects of these variables on both JSN and K–L progression. Results Of 239 manuscripts identified, 34 met inclusion criteria. The mean estimated annual JSN rate was 0.13±0.15mm/year. While we found no significant association between JSN and radiographic approach among observational studies, full extension was associated with greater estimated JSN among randomized control trials (RCTs). Overall, observational studies that used the semi-flexed approach reported greater JSN than RCTs that used the same approach. The overall mean risk of K–L progression by at least one grade was 5.6±4.9%, with higher risk associated with shorter study duration, OA definition (K–L≥2 vs K–L≥1) and cohorts composed of subjects with both incident and prevalent OA. Conclusion While radiographic approach and study design were associated with JSN, OA definition, cohort composition and study duration were associated with risk of K–L progression. These findings may inform the design of disease modifying osteoarthritis drug (DMOAD) trials and assist clinicians in optimal timing of OA treatments.
Kinetic study of thermoelectric currents in the SOL plasmas

Abstract The thermoelectric current instability in SOL plasma is one of the candidates to explain inner–outer plate asymmetries in tokamaks. This phenomenon is usually treated in the fluid approximation based on short mean free path assumptions, which may be violated for typical SOL plasma conditions. We applied a one-dimensional in space and two-dimensional in velocity Fokker–Planck code to study the problem assuming a uniform heat source and the absence of radiation. Kinetic simulation shows that although there does exist a collisionality range in which only asymmetric temperature solutions exist, the magnitude of the standard asymmetry is smaller than obtained from a fluid description and the corresponding thermoelectric currents in the SOL are suppressed.
Innovative Method for Teaching Manual Expression of Breast Milk in a Laboratory Setting

A demonstration breast model was devised and constructed for nursing students to use in practicing manual expression of colostrum and milk. It can also be used for demonstration and practice of exercises for preparation for breastfeeding. The 15 × 27 inch model has proved to be an excellent teaching device. It is economical, can be conveniently stored and is available to students in the audiovisual setting at all times, Instructions for construction are given.
Can computers really help students understand electromagnetics

Some motivations and experiences of a professor who became active twelve years ago in the development of educational software for use in teaching and learning engineering electromagnetics are described. Categories of educational tools are defined, exemplified, discussed, and ranked in order of effectiveness. The author provides opinions as to what has and has not been accomplished. >
Thermoplastic Fusion Bonding of Polymer-Based Micro Devices Using a Pressure Cooker

A novel method of thermoplastic fusion bonding (TPFB), or thermal bonding, for polymer fluidic devices was demonstrated. A pressure cooker was used in a simple sealing and packaging process with precise control of the critical parameters. Polymer devices were enclosed in a vacuum-sealed polymer container. This produced an even pressure distribution and a precise temperature boundary condition over the whole surface of the device. Deformation indicators were integrated on the devices to provide a rapid means of checking deformation and pressure distribution with the naked eye. Temperature, pressure, and time are the fundamental parameters of TPFB. The temperature and pressure are dominated by the material and contact area of the device. The temperature and pressure can be manipulated by controlling the water vapor pressure. The boiling solution guarantees an accurate, constant temperature boundary condition. Time can be eliminated as a variable by choosing a sufficient time to achieve good bonding, since there was no apparent damage to the microstructures after one hour. This new method of TPFB was demonstrated for sealing and packaging a PMMA (polymethylmethacrylate) microfluidic device. Good results were obtained using the vacuum sealed polymer container in the pressure cooker. This method is also suitable for scaling up for mass production.Copyright © 2009 by ASME
The Centers of Early- to Intermediate-Type Spiral Galaxies: A Structural Analysis

A recent Hubble Space Telescope (HST)/WFPC2 visual survey of early- and intermediate-type spiral galaxies has unveiled a great complexity in the inner regions of these systems, which include a high fraction of photometrically distinct compact sources sitting at the galactic centers (nuclei). The faint nuclei (MV -12) are typically hosted by rather amorphous, quiescent, bulgelike structures with an exponential (rather than the classical R1/4) light profile. These exponential bulges are commonly found inside the intermediate-type disks, consistent with previous studies. Brighter nuclei (MV -12) are typically found instead in the centers of galaxies with circumnuclear rings/arms of star formation or dust and an active, i.e., H II- or AGN-type, central spectrum at ground-based resolution. On the structural plane of half-light radius (Re) versus mean surface brightness within the half-light radius (μe), faint and bright nuclei overlap with, and fill the region of parameter space between, the old Milky Way globular clusters and the young star clusters, respectively, with typical Re of about a few up to ≈20 pc. On the same plane, the exponential bulges have significantly fainter μe than R1/4 bulges for any given radius and follow a μe-Re relation typical of disks, which strengthens the suggestion that the exponential bulges grow inside the disks as a result of the secular evolution of the latter. Under the likely assumption that the visual light from the faint nuclei embedded in the quiescent exponential bulges is of stellar origin and of a similar (1 Gyr) age for the central star clusters and their host bulges, the masses inferred for the former agree with those required to disrupt bars comparable in size to the latter. This offers support to scenarios in which the exponential bulges grow inside the disks owing to the orbital disruption of progenitor bars caused by the growth of a central concentration of mass and suggests that this specific mode of bulge formation is (still) active in the present-day universe. On the other hand, the presence of the massive clusters at the very center of the low-density exponential bulges should prevent any other nuclear bar from forming, thereby preventing further infall of dissipative fuel to the nuclear regions. This may argue against the possibility of evolving the exponential bulges into denser, R1/4 bulges by a simple looping for several cycles of the bar formation/disruption mechanism.
Nonuniversal Gaugino Masses and Natural Supersymmetry

We demonstrate that natural supersymmetry is readily realized in the framework of SU(4)c ×SU(2)L ×SU(2)R with nonuniversal gaugino masses. Focusing on ameliorating the little hierarchy problem, we explore the parameter space of this model which yields small fine-tuning measuring parameters (natural supersymmetry) at the electroweak scale (ΔEW) as well as at high scale (ΔHS). It is possible to have both ΔEW and ΔHS less than 100 in these models, (2% or better fine-tuning), while keeping the light CP-even (Standard Model-like) Higgs mass in the 123–127 GeV range. The light stop quark mass lies in the range , and the range for the light stau lepton mass is . The first two family squarks are in the mass range , and for the gluino we find . We do not find any solution with natural supersymmetry which yields significant enhancement for Higgs production and decay in the diphoton channel.
Personal, Farm and Value Orientations in Conversion to Organic Farming

Despite the 20% annual increase in consumption of organic foods, the price premiums for organic produce, and the critical mass of organic production and producers in North Dakota, the level of adoption of organic farming remains quite low. The goal of this research is to assist organic farming agencies and organizations in developing programming targeted to potential adopters of organic farming. It accomplishes this by identifying variables which classify producers as either organic or conventional. While environmental-ethical motivating factors explained the classification of producers into organic and conventional farming categories, none of the farm structural variables and only one personal demographic variable were able to classify producers. In examining the logistic regression analysis, the three most important classificatory factors were environmental-ethical reasons, production orientation, and farming orientation. The implications of the results for programming to target potential adopters of or...
Regulation of epithelial tight junction permeability by cyclic AMP.

In ‘leaky‘ epithelia, ions move through both a transcellular and a paracellular (serial alignment of tight junction and intercellular space) path. The efficiency of transepithelial transport could therefore be regulated if the cell was able to alter reversibly the permeability of tight junctions. (These are specialized regions of the apical cell membranes common to all epithelia.) We now report that such a mechanism indeed exists in the Necturus gallbladder. It is effected by cyclic AMP, which is already known to mediate surface membrane phenomena in a variety of cell systems through its interaction with the cytoskeletal system1,2. In gallbladders mounted and perfused with electrolyte solutions in an Ussing-type chamber, exposure of the mucosal surface to cyclic AMP analogues increased transepithelial electrical resistance, potential difference and short-circuit current and decreased NaCl dilution potentials in a rapid and reversible manner. We also observed rapid depolarization of cell membrane electrical potentials and a slow decline in intracellular K+ activity. Freeze-fracture electron microscopy of tissues fixed with glutaraldehyde during the peak electrical response showed a reorientation of intramembranous junctional fibrils, suggesting that cyclic AMP reduces the ionic permeability of the paracellular pathway in this epithelium by altering the structure of tight junctions.
Relation of Dieting and Voluntary Weight Loss to Psychological Functioning and Binge Eating

Voluntary weight loss in obese patients consistently reduces negative emotions such as depression and anxiety in the short term. Dieting by persons of normal weight is associated with low self-esteem and depressive symptoms. Dieting is linked to the development and maintenance of eating disorders such as anorexia nervosa and bulimia nervosa, although the precise nature of this association is unclear. Dieting cannot be a sufficient causal condition and must combine with other still undetermined vulnerabilities to cause eating disorders. Identification of these risk factors must precede the development of effective programs to prevent eating disorders.
Effects of soybean hulls and lignosulfonate-treated soybean meal on ruminal fermentation in lactating dairy cows.

Abstract Four Holstein cows were used in a 4 × 4 Latin square design to investigate the effects of soybean hulls and lignosulfonate-treated soybean meal on ruminal fermentation and nutrient passage to the duodenum. Diets contained 32% corn silage, 19.8% alfalfa-grass hay, and 48.2% concentrate (DM basis). Treatments, arranged in a 2 x 2 factorial, were concentrate mixes based on 1) corn and soybean meal, 2) corn and treated soybean meal, 3) soybean hulls and soybean meal, and 4) soybean hulls and treated soybean meal. Individual protein supplements supplied 40% of dietary CP, and corn or soybean hulls constituted 28% of dietary DM. Intake of OM (mean 18.9 kg/d) was similar among treatments, but intake of NDF was 42% greater, and intake of nonstructural carbohydrate was 55% less, for cows fed soybean hulls. Passage of OM to the duodenum was similar among diets, but flow of NDF was 43% greater, and flow of nonstructural carbohydrate was 56% less, for cows fed soybean hulls. Ruminal pH was similar, but total concentrations of VFA increased 7% when soybean hulls replaced corn. Ruminal digestion of dietary CP was 15% less for cows fed treated soybean meal, but bacterial N flows were similar among treatments. Soybean hulls were digested to a similar extent as corn, but few interactions occurred between supplemental carbohydrate and protein sources.
Surgical management of double inlet ventricle.

The modified Fontan—Kreutzer procedure and the septation procedure are the two definitive techniques available for managing patients with double-inlet ventricle and two atrioventricular (AV) valves. Other more palliative surgical procedures, such as systemic to pulmonary artery shunts, pulmonary artery banding, AV valve repair, or replacement, and procedures designed to relieve or bypass subaortic stenosis, may be useful either as preparatory procedures or during definitive repair—depending on the specific anatomic and physiologic status of the individual patient. The application of any preliminary palliative procedure should lie within an overall plan leading toward definitive surgical repair [1].
A comparison of predicted and measured aeroheating on a reentry vehicle flap geometry

The purpose of this paper is to illustrate the applicability of two different techniques for predicting flap heating, and to compare the results of these techniques with wind tunnel data obtained on a flap model. The wind tunnel data was obtained in the Naval Surface Weapons Center's Tunnel 9 using an RV model equipped with six drag flaps. One flap and the RV surface surrounding the flap were instrumented with heat transfer gages to measure the heating distributions on the flap surface and side walls and on the surrounding RV surface. The two analytical techniques are related in that they both use an inviscid/boundary layer solution technique to predict aeroheating. The first and less sophisticated of these two techniques uses an inviscid/boundary layer program to predict the heating on the RV surface, as well as the Mach number distribution through the boundary layer and the rotational inviscid layer just upstream of the flap. The technique of Cassel and Jarrett, which makes use of two dimensional oblique shock wave relations, is then used with the predicted upstream Mach number distribution to predict the heating distribution on the flap surface and side walls. The second technique used to predict the flap heatingmore » uses an inviscid and boundary layer approach in which the complete RV and flap geometry is modeled. This technique is significantly more complicated than the first technique, and is capable of modeling the three dimensional aspects of the flowfield in the region of the flap. Thus this approach should produce significantly more accurate solutions than the technique of Cassel and Jarrett which is essentially two dimensional in nature.« less
Hypertrophic cardiomyopathy and its management in children

Summary Hypertrophic cardiomyopathy is a heterogeneous disorder, both from a phenotypic and genotypic standpoint. Predicting which pediatric patients are at greatest risk for disease progression and sudden death may be very difficult clinically. In the future, genetic analysis may become more clinically useful in identifying the high risk patient.
Complex ordering in ternary wurtzite nitride alloys

Abstract Atomic ordering in AlGaN films produced by plasma assisted molecular beam epitaxy (PA-MBE) was investigated with X-ray diffraction (XRD) and transmission electron microscopy selected area diffraction (TEM-SAD). Under nitrogen-rich growth conditions, films undergo 1×1 monolayer cation ordering along the [0001] growth direction. This type of ordering is stronger in N-polar films than in Ga-polar films and is sensitive to the growth ratio of group-III to group-V flux. These observations are in qualitative agreement with the first principal calculations by Northrup and co-workers. Under group-III rich growth conditions of Ga-polar films, the XRD data is consistent with the quasi-random stacking of spontaneously formed 14-ML and 12-ML superlattice structures. Reciprocal space mapping shows a small tilt (0.25°) between the crystallographic c-axis of the wurtzite structure and the superlattice axis. This result can be explained by the presence of c-axis oriented superlattice domains with a parallel step translation between neighboring domains. This result is in qualitative agreement with a recently proposed model by Venezuela and co-workers of self-organized superlattice formation during step flow growth of strained alloys on vicinal surfaces.
Cardiovascular genomics: Outcomes and implications

The application of genomics technology to clinical cardiovascular research is producing fundamentally new insights concerning the etiology of cardiovascular disease phenotypes. Recent genome-wide association studies demonstrate clear associations between single nucleotide polymorphisms and important cardiovascular phenotypes. However, risk alleles for the single nucleotide polymorphisms in question do not explain a sufficient portion of individual risk to be useful for screening purposes. Therefore, clinicians should continue to make use of family history to augment risk stratification and emphasize established forms of prevention for their patients with, or at risk for, cardiovascular disease.
Positive exercise thallium-201 test responses in patients with less than 50% maximal coronary stenosis: Angiographic and clinical predictors

The incidence and causes of abnormal thallium-201 (TI-201) myocardial perfusion studies in the absence of significant coronary artery disease were examined. The study group consisted of 100 consecutive patients undergoing exercise TI-201 testing and coronary angiography who were found to have maximal coronary artery diameter narrowing of less than 50%. Maximal coronary stenosis ranged from 0 to 40%. The independent and relative influences of patient clinical, exercise and angiographic data were assessed by logistic regression analysis. Significant predictors of a positive stress TI-201 test result were: (1) percent maximal coronary stenosis (p less than 0.0005), (2) propranolol use (p less than 0.01), (3) interaction of propranolol use and percent maximal stenosis (p less than 0.005), and (4) stress-induced chest pain (p = 0.05). No other patient variable had a significant influence. Positive TI-201 test results were more common in patients with 21 to 40% maximal stenosis (59%) than in patients with 0 to 20% maximal stenosis (27%) (p less than 0.01). Among patients with 21 to 40% stenosis, a positive test response was more common when 85% of maximal predicted heart rate was achieved (75%) than when it was not (40%) (p less than 0.05). Of 16 nonapical perfusion defects seen in patients with 21 to 40% maximal stenosis, 14 were in the territory that corresponded with such a coronary stenosis. Patients taking propranolol were more likely to have a positive TI-201 test result (45%) than patients not taking propranolol (22%) (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Induction of rat ovarian 20α-hydroxysteroid dehydrogenase activity by gonadotrophic hormone administration

Abstract The increased activity of rat ovarian 20α-hydroxysteroid dehydrogenase observed during proestrus and estrus results in an increased secretion of the biologically weaker or impotent steroid, 20α-hydroxypregn-4-en-3-one, from the gland. The decreased activity of this enzyme during pseudopregnancy allows the progestational potency of the ovarian secretion to rise commensurate with the need. The present study, performed on hypophysectomized prepubertal female rats, was designed to study gonadotrophic hormone action responsible for regulation of 200-hydroxysteroid dehydrogenase and glucose-6-P dehydrogenase activities. Both enzyme activities correlate positively with the process of interstitial cell and thecal cell luteinization achieved either by HCG administration or by simultaneous administration of FSH and LH. Levels of glucose6-P debydrogenase normally present in immature or adult rats are in excess of those required for estrogen biogenesis.
Fine structure of the photoreceptor of the ascidian tadpole during development

The eye of the tadpole larva of Amaroucium constellatum consists of 15–20 photoreceptor cells, a single pigment cup cell, and three lens cells. Each photoreceptor cell during its development gives rise apically to a neck process and basally to an axon, which is thought to extend to the cerebral ganglion. At the tip of the neck a sensory cilium differentiates to produce the photoreceptor membranes. This process begins as a balloon-shaped evagination of the cell membrane above the ciliary basal body. This evagination infolds to form the presumptive photosensitive lamellae which increase in number, length, and regularity as the eye matures. Microvilli also arise from the tip of this cell and intermingle with the ciliary membranes. The neck process itself elongates, narrows, and becomes filled with microtubules during development. The pigment cell, initially long, flat, and electron lucent, develops into a cupshape. Its cytoplasm becomes packed with pigment granules, forming an effective light shield. The development of the lens cells involves formation of the lens vesicles and elongation of the cells into the lumen of the pigment cup. Differentiation of ascidian photoreceptor cells is compared with that of the vertebrate rod and cone.
Multifunction - Laser speckle blood flow and deoxy-hemoglobin saturation - Imaging of cerebrovascular response

A laser speckle imaging (LSI) technique, with high spatio-temporal resolution, is presented for studying cerebrovascular response to stimulation. LSI is evaluated in a rodent model of cerebrovascular activity, in a model of migraine, by eliciting functional response to brain trigeminal nerve stimulation. The specific haemodynamic response, including deoxy-hemoglobin saturation and blood flow responses in cortical vessels to the abnormal activation of the trigeminal system, are obtained from the processed LSI images. The simultaneous optical imaging methods for imaging blood flow and deoxygenation saturation changes could be of great use in basic investigation of functional brain responses in conditions such as migraine and for evaluating investigational therapeutic solutions.
Reflected optical harmonics from dielectric mirrors

Optical second and third harmonics were generated in reflection from commercially available laser dielectric mirrors. Although most dielectric coatings on laser mirrors are centrosymmetric, the inversion symmetry is broken at the dielectric–air interface. When intense femtosecond laser pulses are reflected off the dielectric mirrors, a second-order dipole contribution to surface second-harmonic generation can exist and is detected. More dramatically, at a laser fluence of ~ 10 GW/cm2 the normally much weaker electric-dipole-allowed third-harmonic generation that originated in the bulk accentuates the second-harmonic generation. These reflected harmonics are, in some cases, nonnegligible in many sensitive experiments.