cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis of superporous hydrogels: Hydrogels with fast swelling and superabsorbent properties

We have been interested in the synthesis of hydrogels with fast swelling kinetics and superabsorbent properties. To increase the water absorption rate, interconnected pores were introduced to the hydrogels. Since the pore size in the dried hydrogels is in the order of hundreds of micrometers, these hydrogels are called "superporous" hydrogels. Superporous hydrogels were synthesized by crosslinking polymerization of various vinyl monomers in the presence of gas bubbles formed by the chemical reaction of acid and NaHCO3. The polymerization process was optimized to capture the gas bubbles inside the synthesized hydrogels. The use of the NaHCO3/acid system allowed easy control of timing for gelation and foam formation. We found that PF127 was the best foam stabilizer for most of the monomer systems used in our study. Scanning electron microscope (SEM) pictures showed interconnected pores forming capillary channels. The capillary channels, which were critical for fast swelling, were preserved during drying by dehydrating water-swollen hydrogels with ethanol before drying. The ethanol-dehydrated superporous hydrogels reached equilibrium swelling within minutes. The equilibrium swelling time could be reduced to less than a minute with the use of a wetting agent. In our study, water moisture was used as a wetting agent since the amount of moisture content in the dried hydrogels easily could be controlled. Preparation of superporous hydrogels using the right blowing system, foam stabilizer, drying method, and wetting agent makes it possible to reduce the swelling time to less than a minute regardless of the size of the dried gels. The superporous hydrogels can be used where fast swelling and superabsorbent properties are critical.
Hole superconductivity: The strong coupling limit

Abstract A Hamiltonian describing hole superconductivity is studied in the limit where the single particle hopping amplitude t goes to zero. It is shown that superconductivity can occur in this regime with purely repulsive Coulomb interactions, similarly to what occurs in the weak coupling case. The critical temperature remains finite as t→0. No bound pairs exist above Tc except for extremely low density of holes, and above Tc holes are localized.
Phenomenology as Insider Trading: Some Stipulations for the Religious "Skin Trade"

This paper examines some of the interpretations of the insider/outsider distinction as it is understood in the study of religion but in light of Jerry Fodor and Ernest Lepore's arguments about semantic holism and atomism. It argues that this application shows that if the outsider/insider distinction is approached as a form of global holism coupled with linguistic determinism, then it is a pseudo-problem and no further energy ought to be wasted on it. Also argued is that radically exclusive insidership or radically inclusive insidership are indefensible positions. Instead, this paper proposes that access to the inside of a worldview is, in principle, no different for a insider than for an outsider; it is a matter of degree and not kind. No variety of religious information is, per se, incommunicable, except that of the individual subject's existential subjecthood. Insidership and outsidership in the academic study of religion indicate positions with respect to agency, thematization, and explanation and should not be defined, primarily, by occupation, material, or methods.
Model of Human Chorionic Gonadotropin and Lutropin Receptor Interaction That Explains Signal Transduction of the Glycoprotein Hormones

Abstract The goal of these studies was to devise a model that explains how human chorionic gonadotropin (hCG) interacts with lutropin (LH) receptors to elicit a hormone signal. Here we show that α-subunit residues near the N terminus, the exposed surface of the cysteine knot, and portions of the first and third loops most distant from the β-subunit interface were recognized by antibodies that bound to hCG-receptor complexes. These observations were combined with similar data obtained for the β-subunit (Cosowsky, L., Rao, S. N. V., Macdonald, G. J., Papkoff, H., Campbell, R. K., and Moyle, W. R.(1995) J. Biol. Chem. 270, 20011-20019), information on residues of hCG that can be changed without disrupting hormone function, the crystal structure of deglycosylated hCG, and the crystal structure of a leucine-repeat protein to devise a model of hCG-receptor interaction. This model suggests that the extracellular domain of the LH receptor is “U-” or “J”-shaped and makes several contacts with the transmembrane domain. High affinity hormone binding results from interactions between residues in the curved portion of the extracellular domain of the receptor and the groove in the hormone formed by the apposition of the second α-subunit loop and the first and third β-subunit loops. Most of the remainder of the hormone is found in the large space between the arms of the extracellular domain and makes few, if any, additional specific contacts with the receptor needed for high affinity binding. Signal transduction is caused by steric or other influences of the hormone on the distance between the arms of the extracellular domain, an effect augmented by the oligosaccharides. Because the extracellular domain is coupled at multiple sites to the transmembrane domain, the change in conformation of the extracellular domain is relayed to the transmembrane domain and subsequently to the cytoplasmic surface of the plasma membrane. While the model does not require the hormone to contact the transmembrane domain to initiate signal transduction, small portions of both subunits may be near the transmembrane domain and assist in initiating the hormonal signal. This is the first model that is consistent with all known information on the activity of the gonadotropins including the amounts of the hormone that are exposed in the hormone-receptor complex, the apparent lack of specific contacts between much of the hormone and the receptor, and the roles of the oligosaccharides in signal transduction. This model differs from existing models of hormone action in that the extracellular domain has a much larger role in hormone action than serving as a high affinity hormone trap.
Image complexity and spatial information

The complexity of an image tells many aspects of the image content and is an important factor in the selection of source material for testing various image processing methods. We explore objective measures of complexity that are based on compression. We show that spatial information (SI) measures strongly correlate with compression-based complexity measures. Among the commonly used SI measures, the mean of the edge magnitude is shown to be the best predictor. Moreover, we find that compression-based complexity of an image normally increases with decreasing resolution.
A mixing model for turbulent reactive flows based on Euclidean minimum spanning trees

In modeling turbulent reactive flows based on the transport equation for the joint probability density function (jpdf) of velocity and composition, the change in fluid composition due to convection and reaction is treated exactly, while molecular mixing has to be modeled. A new mixing model is proposed, which is local in composition space and which seeks to address problems encountered in flows with simultaneous mixing and reaction. In this model the change in particle composition is determined by particle interactions along the edges of a Euclidean minimum spanning tree (EMST) constructed in composition space. Results obtained for the model problem of passive scalars evolving under the influence of a mean scalar gradient in homogeneous turbulence are found to be in reasonable agreement with experimental findings of Sirivat and Warhaft (1983). The model is applied to the diffusion flame test model problem proposed by Norris and Pope (1991) and its performance is found to be superior to that of existing models. The essential feature of the new EMST mixing model, which accounts for its success in the diffusion flame test, is that mixing is modeled locally in composition space.
Aggregation of rose bengal molecules in solution

Abstract Absorption, emission and excitation spectral data support the thesis that rose bengal forms H-type aggregates in water and polar, protic solvents.
Alliance Treaty Obligations and Provisions, 1815-1944

This article introduces the Alliance Treaty Obligations and Provisions (ATOP) dataset. We begin by describing the rationale for collecting the ATOP data, its scope, and some general coding rules for the project. Then we offer some descriptive statistics for phase one of the dataset, which covers the years 1815-1944, and reveal some interesting trends in alliance politics. Finally, we replicate a study of alliance formation originally conducted by Lai and Reiter (2000) to demonstrate the effect the use of ATOP data may have on past inferences about alliance politics.
THE RELATIONSHIP OF TOTAL SERUM CARBON DIOXIDE TO THE SEVERITY OF OBSTRUCTIVE SLEEP APNEA (OSA) IN CHILDREN † 575

Total venous serum carbon dioxide (tCO2) is known to be elevated in some patients with OSA. To determine how reliable it is as a method of diagnosing OSA and predicting its severity, we reviewed retrospectively the charts of all 44 children, mean age 5.9 years, who had a laboratory diagnosis of obstructive sleep apnea in 1994-1995. All of these children underwent a nap sleep study which was positive, with a respiratory disturbance index (RDI)(number of apneas and hypopneas divided by the duration of study in hours)>5 and a mean of 28, and all had random measurements of tCO2 The majority of the children (59%) had elevated tCO2 (>25mg/dl) with a maximum of 31 mg/dl, 18 (41%) children had normal or low tCO2, but there was poor correlation between the RDI and the tCO2 (r 0.05).
TREATMENT PLANNING FOR PULSED REDUCED DOSE-RATE RADIOTHERAPY IN HELICAL TOMOTHERAPY

Purpose Pulsed reduced dose-rate radiotherapy (PRDR) is a valuable method of reirradiation because of its potential to reduce late normal tissue toxicity while still yielding significant tumoricidal effect. A typical method using a conventional linear accelerator (linac) is to deliver a series of 20-cGy pulses separated by 3-min intervals to give an effective dose-rate of just under 7 cGy/min. Such a strategy is fraught with difficulties when attempted on a helical tomotherapy unit. We investigated various means to overcome this limitation. Methods and Materials Phantom and patient cases were studied. Plans were generated with varying combinations of field width (FW), pitch, and modulation factor (MF) to administer 200 cGy per fraction to the planning target in eight subfractions, thereby mimicking the technique used on conventional linacs. Plans were compared using dose–volume histograms, homogeneity indices, conformation numbers, and treatment time. Plan delivery quality assurance was performed to assess deliverability. Results It was observed that for helical tomotherapy, intrinsic limitations in leaf open time in the multileaf collimator deteriorate plan quality and deliverability substantially when attempting to deliver very low doses such as 20-40 cGy. The various permutations evaluated revealed that the combination of small FW (1.0 cm), small MF (1.3–1.5), and large pitch (∼0.86), along with the half-gantry-angle-blocked scheme, can generate clinically acceptable plans with acceptable delivery accuracy (±3%). Conclusion Pulsed reduced dose-rate radiotherapy can be accurately delivered using helical tomotherapy for tumor reirradiation when the appropriate combination of FW, MF, and pitch is used.
High throughput glutathione and Nrf2 assays to assess chemical and biological reactivity of cysteine-reactive compounds

Compounds that inhibit their target through covalent binding offer a number of unique advantages as potential therapeutic agents. They can achieve high ligand efficiency, and thus high potency, which can translate into a reduced drug dosage. In addition, covalent binding can result in a long duration of action of the compound and thus less frequent drug dosing. Despite these advantages, there are several safety concerns about this class of compounds because of their inherent reactivity and potential for non-specific binding to cellular proteins. The primary aim of this study was to establish the thiol reactivity of acrylamides and other cysteine-reactive groups by measuring reactivity against various cysteine-containing cellular components. Compounds were incubated with glutathione, bovine serum albumen (BSA) or human liver microsomes (HLM), and the reduction in thiol levels was quantitated using Ellman's reagent. In addition, the ability of compounds to induce Nrf2 activity in a reporter gene assay was used as a functional readout of compound reactivity. The assays were validated using known thiol-reactive compounds and Nrf2 inducers such as sulforaphane (SFP) and 1,2-dithiole-3-thione (D3T). Our results demonstrate that acrylamides possess low reactivity unless activated by electron-withdrawing N-substituents. Analogous propynamides and vinyl sulphones were more reactive than acrylamides with respect to glutathione activity but were less reactive in the Nrf2 assay. Large drug-like molecules, including irreversible kinase inhibitors targeting BTK and EGFR, were far less reactive than their lower molecular weight counterparts, suggesting that the presence of an electrophile is not sufficient to predict thiol reactivity. These studies demonstrate the utility of multiple thiol sources in addition to glutathione when assessing the thiol reactivity of covalent inhibitors.
Pseudomonas aeruginosa hypoxic or anaerobic biofilm infections within cystic fibrosis airways

The airways of patients afflicted with cystic fibrosis (CF) are colonized by many pathogens, the most predominant of which is the Gram-negative bacterium Pseudomonas aeruginosa. In the thick CF airway mucus, P. aeruginosa forms antibiotic- and phagocyte-resistant structures known as biofilms, which enable the survival and growth of the organism. P. aeruginosa can undergo dramatic genetic, physiological and morphological changes in this milieu. Chronic infection leads to a considerably reduced oxygen tension, and it is believed that some bacteria grow anaerobically, especially during late-stage disease. In this article, factors that enable long-term survival of P. aeruginosa and two novel drug targets (the rhl quorum-sensing circuit and the anti-sigma factor, MucA) are discussed. Mutants lacking these factors might be uniquely susceptible to nitrogen oxide, specifically the nitrite anion (NO2−), in the treatment of P. aeruginosa airway infections in CF.
Analytical beam theory for the in-plane deformation of a composite strip with in-plane curvature

Abstract The variational-asymptotic-method (VAM) provides a mathematically rigorous way to reduce a three-dimensional elasticity formulation to a one-dimensional beam theory without ad hoc assumptions. In this work, the VAM is employed to develop a beam theory to analyze the in-plane deformation of a laminated strip-beam with initial in-plane curvature. The cross-sectional stiffness constants and recovery relations for stress and strain are presented as analytical expressions. For the case of zero initial curvature, consistency of the expressions with those of plate theory is demonstrated. For strip-beams with initial curvature in the in-plane direction, results obtained show explicit dependence on the curvature. Results are verified by comparison with those obtained from VABS, the accuracy and consistency of which with three-dimensional finite elements has been reported in several published works. In addition to the internal consistency check this work provides and its utility in helping to validate VABS (which is based on the principles of VAM), it is hoped that the results obtained herein, since they are all analytical expressions, will help researchers and engineers validate the effect of initial curvature in their beam theories, whether existing or new.
Agonist-stimulated [35S]GTPγS autoradiography : optimization for high sensitivity

Abstract The receptor-stimulated accumulation of [35S]GTPγS provides a measure of functional coupling of G proteins with receptors. Sensitivity for autoradiographic visualization of [35S]GTPγS binding was improved two- to threefold in rat brain sections by optimizing assay conditions. Non-specific (NSB), basal and agonist-stimulated [35S]GTPγS binding were measured, using methadone, 5-carboxamidotryptamine and epinephrine for μ-opiate receptors, 5-HT1A receptors and α2-adrenoceptors. Basal and NSB were low in glycylglycine buffer compared to Tris or HEPES buffers, and agonist-stimulated [35S]GTPγS binding was more easily observed. Further optimization using glycylglycine buffer found increased signal-to-noise ratio with inclusion of dithiothrietol, increased [35S]GTPγS incubation time (2–4 h) and guanosine 5′-diphosphate (GDP) preincubation (20–30 min), and use of [35S]GTPγS at 0.1 nM. Improved sensitivity was due to decreased NSB and basal [35S]GTPγS binding and agonist-stimulated binding were similarly affected for each receptor system. The assay conditions described should extend the use of agonist-stimulated [35S]GTPγS autoradiography to receptors, which produce low levels of [35S]GTPγS binding and to the measurement of changes in receptor–G protein coupling.
The Role of Monoamine Oxidase Inhibitors in Depression Treatment Guidelines

Monoamine oxidase inhibitors (MAOIs) have proven efficacy for treating depression and for decades have been a preferred treatment for patients with atypical depression, high levels of anxiety, anergic bipolar depression, and treatment-resistant depression. However, MAOIs are infrequently used due to safety and tolerability concerns and the need for dietary restrictions. Current guidelines, which are reviewed here, recommend MAOIs as third-, fourth-, or fifth-line treatments due to these concerns. However, a transdermal formulation of selegiline limits the need for dietary restrictions and has fewer side effects than many more widely used antidepressants. The availability of a safer and more tolerable formulation gives clinicians another option in their armamentarium for treating depression.
Effect of the vasodilator trimazosin versus placebo on exercise performance in chronic left ventricular failure

The effect of the vasodilator trimazosin versus placebo on exercise duration until marked dyspnea was evaluated in a double blind randomized study in 16 patients with chronic left ventricular failure despite digitalis and diuretic therapy. Trimazosin caused a reduction in resting systolic and diastolic blood pressures and in resting product of systolic blood pressure times heart rate. The improvement in exercise duration from the average of values during the baseline and single blind placebo periods was greater after 3 and 6 weeks of trimazosin therapy (300 and 450 mg daily) after 3 and 6 weeks of double blind placebo therapy (P < 0.025). Four of eight patients receiving trimazosin had disappearance of pulmonary venous congestion on chest roentgenography compared with none of eight patients receiving placebo. These preliminary data suggest that trimazosin may be effective in treating chronic left ventricular failure.
Experimental verification of a single transducer back-action evading measurement scheme for a gravitational wave detector

Abstract We have demonstrated classical squeezed states which result from a back-action evading measurement on a mechanical harmonic oscillator. This is experimental demonstration of a technique which can be used to explore the “standard” quantum limits of measurement.
Decreased loading after rotator cuff tears leads to improved biceps tendon properties in a rat model.

Background The purpose of this study was to elucidate the mechanism of biceps tendon changes after rotator cuff tears. We hypothesized that increased loading on the biceps tendon after rotator cuff tears will result in further detrimental changes whereas decreased loading will result in increased organization and more normal tendon composition. In addition, we hypothesized that changes with altered loading will begin at the proximal insertion into bone and progress along the tendon length at later time points. Materials and methods Supraspinatus and infraspinatus tendon detachments in rats were followed by various loading protocols at various time points. Regional changes in cellularity, cell shape, collagen organization, and matrix proteins of the long head of the biceps tendon were determined by histologic measures and immunohistochemistry. Results Increased loading after detachments resulted in more disorganized collagen after only 1 week and compositional changes by 4 weeks. By 8 weeks, decreased loading resulted in increased organization, decreased cellularity, a more elongated cell shape, and more normal tendon composition. Organizational changes with increased loading began in the intra-articular space and progressed along the tendon length with time. Conclusions Combined with previous findings of decreased mechanics with increased loading, these results show that increased compressive loading away from the proximal insertion into bone is a mechanism for biceps tendon pathology in the presence of rotator cuff tears. The striking improvements with decreased loading further support increased loading as a mechanism for biceps tendon pathology because removal of this load led to improvements in tendon histology, organization, and composition.
Vocal regulation of use of space by groups of titi monkeys Callicebus moloch

The daily movements and the resulting activity and calling fields are described for three groups of titi monkeys Callicebus moloch. Groups move to the periphery of their home range in the early morning and then call. Playback experiments confirmed that both proximity and location of calling by neighboring animals affect the group's response. Subsequent countercalling often regulates the approach of neighboring groups to a boundary. After encountering adjacent groups, animals return to areas near the home range center. Movements, calling behavior, and the response to neighboring groups all increase the probability of intergroup encounters in the early morning. Encounters define and reinforce the conventional location of boundaries. Boundaries decrease the probability of intergroup encounters at other times and allow exclusive use of space.
Reply to Drury and Theall: No evidence of population stratification.

We appreciate the opportunity to address the five critiques raised by Drury and Theall in their letter (1) concerning our recent article (2). First, Drury and Theall explain that previous studies used saliva to measure telomere length (TL), and they provide two examples in the literature. We indicate that this is the case in our paper [for example, we state that “Our study validates other work showing that multiple tissues, including saliva, can be used to measure TL…” (2)]. We also provide two references following this statement, including one to a paper by Theall et al., which they also referred to in their letter (3). Our study differed in providing a comparison between saliva and mononuclear cell TL (figures S2 and S3 in ref. 2). Second, Drury and Theall point to two other studies using African American children, one of which we also cite (3). One of these two studies (4) did not include an exclusively African American sample, the other (3) did, and we regret the oversight. Third, and most important, Drury and Theall are concerned that we overlook significant differences in allele frequencies between the two extreme groups. However, the authors appear to have treated table S1 in our report (2) as containing cell counts instead of percentages. So doing would grossly overestimate the significance of any apparent difference. In Table 1 we provide the χ2 tests of harsh vs. nurturing environment by gene using cell count (test 1 in Table 1). None is significant. Fourth, Drury and Theall are correct that we did not supply estimates of similarity to African American population or Hardy–Weinberg Equilibrium (HWE). Although HWE is straightforward to estimate (see test 2 in Table 1), comparing our 40-person sample to what is expected of the African American population is more difficult. In test 3 of Table 1 we provide a χ2 test of our 40-person sample to the African American sample in the larger, population-based Fragile Families study (n = 1,393). We have also compared the minor allele frequency of the entire Fragile Families African American sample to estimates available in HapMap and found them to be generally in accord. Finally, the fifth concern was that there was no statistical evidence of differential susceptibility, only visual. As we note in our report (see especially figure 1 of ref. 2), dopaminergic pathway genes do not fit this pattern; however, the serotonergic pathway genes may. Moreover, although we do not indicate that our data confirm the differential susceptibility hypothesis—only that it is consistent with it—the observation that the TL is longest in advantaged subjects with the 2+ sensitizing genotype is inconsistent with the diathesis-stress model. Further statistical testing will await the analysis of many more subjects, which is currently underway. In sum, we feel our results are correct and appreciate the opportunity to provide additional information to support this conclusion.
Inhibitors of tyrosine and ser/thr phosphatases modulate the heat shock response

Following heat shock the expression of heat shock genes is regulated by the heat shock transcription factor, HSF, known to bind to arrays of the heat shock element, NGAAN, upstream of the heat shock genes. Phosphorylation of HSF is necessary for its activation. We report that the treatment of Chinese hamster HA-1 cells with 250 nM of okadaic acid (OA), a ser/thr phosphatase inhibitor, leads to an increase in activated HSF after heat shock. This is followed by the activation of the transcription of heat shock genes as assayed by the increase in the synthesis of β-galactosidase in an HA-1 cell line containing the heat shock promoter ligated to the β-galactosidase gene. To investigate the specificity of OA, we used other phosphatase inhibitors. We found that treatment of HA-1 cells with 500 μM of sodium vanadate, an inhibitor of tyr/phosphatases, resulted in a three to fivefold reduction in HSF activation and binding to the heat shock element following heat shock. Such reduction in HSF activation virtually abolished β-galactosidase induction. Reduced HSP synthesis was further confirmed by SDS-PAGE and Western blot analysis using anti–HSP-70 and 28 antibodies. Sodium vanadate treatment of heat shocked cells greatly reduced levels of thermotolerance. These results show that ser/thr and specifically tyr/phosphatase inhibitors modulate the signal transduction pathway of HSF activation.
Audiogenic convulsions in moderate seizure genetically epilepsy-prone rats (GEPR-3s)

The moderate seizure genetically epilepsy-prone rat (GEPR-3) typically exhibits a generalized clonic convulsion upon acoustical stimulation. The purpose of this report is to document sex-specific distinctions in the seizure characteristics as well as the effect of prior seizure experience on sensitivity to acoustically induced seizures in members of the GEPR-3 colony. Convulsive behavior was evaluated in approximately 3300 GEPR-3s. Each of these animals was stimulated with sound 3 times at weekly intervals. Audiogenic response score (ARS), latency to the onset of wild running and latency to convulsion were recorded for each animal in each of 3 tests given at 1 week intervals. Statistical analysis revealed that compared to their male littermates, females exhibited significantly shorter latencies to onset of running and convulsion for the last of the 3 weekly tests. Also, in both sexes, a significantly higher incidence of clonic convulsions, an increase in audiogenic response scores and a reduction in latencies to running and convulsion were observed in each succeeding audiogenic stimulation test. The mechanism of this increased seizure facilitation with prior seizure experience may have at least some similarity to that of kindling. The factors responsible for sex-specific distinctions in seizure severity are unknown at the present time.
Measurement of multiple unrelated physical quantities using a single magnetic field response sensor

This paper presents a non-contact method for powering and interrogating magnetic field response sensors that facilitates measurement of multiple unrelated physical quantities using the same sensor. The sensors are electrically passive inductive–capacitive or passive inductive–capacitive–resistive circuits that are powered using oscillating magnetic fields, and once electrically active, the sensors respond with their own oscillating magnetic fields. The sensor's magnetic field response frequency, amplitude and bandwidth are correlated to the magnitude of one or more physical quantities that each sensor measures. The magnetic field response sensors and the technique for powering and interrogation alleviate many shortcomings of traditional sensor/measurement systems. The shortcomings are having a data acquisition channel dedicated to each sensor, wiring/circuitry weight associated with measurements, electrical arcing, wire degradations due to wear or chemical decay and the logistics needed to add new sensors. Because measurements can be derived from influences upon the sensor's magnetic field or electrical field, the circuit that forms the sensor need not be in physical contact with the measurand. The method for discerning sensor response frequency, resistance and amplitude is presented herein. The method does not require the sensors to be near or physically connected to acquisition hardware or a power source. The theoretical basis for the measurement acquisition technique is discussed including the influence of key parameters on measurement acquisition. One example of a magnetic field response sensor for measuring the magnitude of three unrelated physical quantities—material phase transition, temperature and position—will be presented. A fluid-level measurement will also be presented.
A prediction for Neptune's exospheric temperature

The temperature of Neptune's exosphere is predicted, using Voyager observations of the exospheric temperatures of the outer planets. The exospheric temperature at Neptune is estimated at about 200 K, compared with about 800 K at Uranus. The implictions of this work for the existence of a Neptune electroglow are discussed.
In situ nuclear magnetic resonance determination of paramagnetic susceptibilities of electrogenerated species

A method is herein described for determining in situ the atomic magnetic susceptibility of a metal ion in an electrogenerated complex (corrected by the diamagnetic susceptibility associated with the ligands) in aqueous solutions by monitoring the shift in the (water) proton resonance present as an adventitious impurity in the D 2 O-based electrolyte. As predicted by Evans formalism, the total shift for mixtures of the diamagnetic [Fe(CN) 6 ] 4- and paramagnetic[Fe(CN) 6 ] 3- prepared electrochemically in situ was found to be proportional to the concentration of [Fe(CN) 6 ] 3-
Assessment of synchronized direct mechanical ventricular actuation in a canine model of left ventricular dysfunction

Direct mechanical ventricular actuation (DMVA) is an experimental procedure that provides biventricular cardiac assistance by intracorporeal pneumatic compression of the heart. The advantages this technique has over other assist devices are biventricular assistance, no direct blood contact, pulsatile blood flow, and rapid, less complicated application. Prior studies of nonsynchronized DMVA support have demonstrated that a subject can be maintained for up to 7 days. The purpose of this study was to determine the acute hemodynamic effects of cardiac synchronized, partial DMVA support in a canine model (RVP) of left ventricular (LV) dysfunction. The study consisted of rapidly pacing seven dogs for 4 weeks to create LV dysfunction. At the conclusion of the pacing period, the DMVA device was positioned around the heart by means of a median sternotomy. The animals were then imaged in a 1.5 T whole body high speed clinical MR system, with simultaneous LV pressure recording. Left ventricular pressure-volume (PV) loops of the nonassisted and DMVA assisted heart were generated and demonstrated that DMVA assist shifted the loops leftward. In addition, assist significantly improved pressure dependent LV systolic parameters (left ventricular peak pressure and dp/dt max, p < 0.05), with no diastolic impairment. This study demonstrates that DMVA can provide synchronized partial assist, resulting in a decrease in the workload of the native heart, thus having a potential application for heart failure patients.
Intensification of externally applied magnetic field around a crack in layered composite

Abstract Dynamic stress intensification around the crack in a layered composite subjected to an externally applied magnetic field is investigated. The effect of magnetic force is accounted for in the analysis as a body force. It tends to introduce damping into the system and reduces the intensification of the crack tip stress field. This is illustrated through the variations of the Mode I and Mode II stress intensity factors with time in addition to the influence of the geometric and material parameters of the composite structure. Numerical results are presented and discussed as the magnetic flux is varied with the physical parameters.
ANALYTICAL SOLUTION OF NON-HOMOGENEOUS WAVE EQUATION

Models for shallow water wave processes are routinely applied in coastal, estuarine and river engineering practice, to problems such as flood waves, tidal circulation, tsunami penetration, and stor...
Influence of combined nitrogen level andEucalyptus competition on dinitrogen fixation in nodulatedCasuarina

Experiments were conducted to determine the effect on biological dinitrogen fixation byCasuarina of available nitrogen (N) in the substrate and competition by interplantedEucalyptus. In these experiments, combined N was applied to the plants after nodules were developed and functioning. Both environmental factors, nitrate and competition, were observed to influence biological dinitrogen fixation byCasuarina, but not yield (total dry weight). In one experiment, the proportion of nitrogen derived byCasuarina from atmospheric fixation (pNdfa) was observed to be inhibited by potassium nitrate in a linear fashion. However, substrate N did not significantly affect the weight of root nodules. Thus nodule dry weight was not highly correlated with the proportion of nitrogen fixed. In a second experiment, the presence of a non-fixing interplanted species,Eucalyptus, increased dinitrogen fixation inCasuarina.Casuarina interplanted withEucalyptus obtained a greater proportion of its nitrogen (94.75%) from fixation than didCasuarina grown alone (86.68%) suggesting that competition for substrate N influences the proportion of nitrogen fixed by this actinorhizal plant.
Values of k for Slab on Winkler Foundation

Using nondimensional parameters for the analysis of a slab on a layered soil medium, a method is developed to evaluate an equivalent modulus of subgrade reaction k to be used in the Winkler model. Here, a constant value of Poisson's ratio for the soil, νs = 0.25 is used. Graphs are provided from which an equivalent value of k can be computed as soon as the complete geometry and the properties of the overall system are known. Numerical examples are given to show the comparisons of results from the equivalent Winkler k parameter with those from a modified Vlasov model and by using the value of k suggested by Biot and Vesic.
Soluble guanylyl cyclase is an ATP sensor coupling nitric oxide signaling to cell metabolism

Defending cellular integrity against disturbances in intracellular concentrations of ATP ([ATP]i) is predicated upon coordinating the selection of substrates and their flux through metabolic pathways (metabolic signaling), ATP transfer from sites of production to utilization (energetic signaling), and the regulation of processes consuming energy (cell signaling). Nitric oxide (NO) and its receptor soluble guanylyl cyclase (sGC) are key mediators of cellular energetics and can regulate ATP supply and demand. However, mechanisms coordinating NO/sGC and energetic signaling remain undefined. Here, we demonstrate that sGC is a nucleotide sensor whose responsiveness to NO is regulated by intracellular ATP ([ATP]i). ATP inhibits purified sGC with a Ki predicting >60% inhibition of NO signaling in cells maintaining physiological [ATP]i. ATP inhibits sGC by interacting with an allosteric site that prefers ATP>GTP. Moreover, in RFL-6 cells, alterations in [ATP]i are coupled to NO/sGC signaling. Indeed, oligomycin, an inhibitor of mitochondrial ATP synthase, reduced [ATP]i 48%, from 1.25 nmol to 0.65 nmol of ATP/mg protein, but increased [cGMP]i 45%, from 42 to 61 pmol/mg protein. Thus, [ATP]i serves as a “gain control” for NO signaling by sGC. At physiological [ATP]i, NO signaling by sGC is repressed, while insults that reduce [ATP]i, such as ischemia, de-repress sGC and amplify responses to NO. Clinical Pharmacology & Therapeutics (2004) 75, P46–P46; doi: 10.1016/j.clpt.2003.11.171
Random mutagenesis of staphylococcal nuclease and phage display selection

Abstract Multiple cycles of mutagenesis and phage display selection have been investigated as a method for obtaining enzymes with altered catalytic properties. A library of staphylococcal nuclease mutants displayed on phage was created by errorprone PCR mutagenesis and selected for binding to thymidine- or guanosine-containing substrate analogs. After discarding non-binders, the binding mutants were then subjected to further mutagenesis and selection rounds. After four mutagenesis and selection cycles, the catalytic properties of some of the resulting nucleases were studied and one nuclease with nine accumulated mutations was found to have a two-fold reduction in k cat for DNA hydrolysis, but a two-fold increase in k cat / K m for hydrolysis of a thymidine containing small molecule substrate. The possibility of this technique for in vitro evolution of enzyme properties is discussed.
Predictive cost-based scheduling for scalable media streaming

We propose a scheduling policy, called Predictive Cost-Based Scheduling (PCS) for scalable video streaming. PCS schedules the waiting requests based on their required delivery costs, predicts future system state, and uses the prediction results to possibly alter the scheduling decisions. We also present two alternative implementations of PCS and analyze its waiting-time predictability. The simulation results show that PCS can achieve significant performance improvements and can provide users with highly accurate expected waiting times.
Sustainable Transportation U.S. Dilemmas and European Experiences

The approach to sustainable transportation issues in the United States was examined in light of findings from a study of sustainable transportation planning in Sweden, Germany, the Netherlands, and Scotland. In the European countries, reducing greenhouse gases has been the initial motivation for most sustainable transportation initiatives, but broader social, economic, and environmental concerns now figure into the idea of sustainability. In the United States, barriers to greenhouse gas reduction and planning for sustainability include uncertainty about the problem and the best ways to address it, uncertainties about public support, and the lack of a clear mandate for action. Nevertheless, efforts are under way locally in the United States to promote sustainable development, and transportation plays a central role in these plans. The European organizations visited are using many of the same strategies as are U.S. planners, but supporting their efforts are strong policy commitments, government incentives, ...
Clostridium difficile colonization and diarrhea at a tertiary care hospital

Clostridium difficile is the major identifiable infectious cause of nosocomial diarrhea. A prospective study was conducted at New England Deaconess Hospital (Boston) to examine risk factors for C. difficile carriage at both admission and follow-up. Specimens from patients admitted to two wards (one medical, one surgical) and three intensive care units (two surgical, one medical) were cultured weekly until discharge. For 89 (18%) of 496 patient admissions, at least one culture was positive. The prevalence of culture positivity within 72 hours of admission was 11%. Risk factors for culture positivity at admission were prior C. difficile diarrhea (adjusted odds ratio [OR] = 9.5), renal insufficiency (OR = 6.7), and recent hospitalization elsewhere (OR = 3.1). Fifteen percent of patients for whom initial cultures were negative and for whom follow-up cultures were performed acquired C. difficile. Admission to the vascular surgery service (relative risk [RR] = 2.3) and liver transplantation (RR = 4.2) were significant risk factors for C. difficile acquisition. Patients asymptomatically colonized on admission had very low risk (1 in 44) for subsequent development of C. difficile diarrhea. In contrast, nine (47%) of 19 patients who acquired toxigenic strains developed C. difficile diarrhea, a finding suggesting that progression to diarrhea occurs early after acquisition or does not occur at all. The relatively high prevalence of culture positivity at admission may be characteristic of tertiary care hospitals and adds to the difficulty of controlling this nosocomial pathogen.
Continuous cognitive dynamics of the evaluation of trustworthiness in williams syndrome

The decision to approach or avoid an unfamiliar person is based in part on one’s evaluation of facial expressions. Individuals with Williams syndrome (WS) are characterized in part by an excessive desire to approach people, but they display deficits in identifying facial emotional expressions. Likert-scale ratings are generally used to examine approachability ratings in WS, but these measures only capture an individual’s final approach/avoid decision. The present study expands on previous research by utilizing mouse-tracking methodology to visually display the nature of approachability decisions via the motor movement of a computer mouse. We recorded mouse movement trajectories while participants chose to approach or avoid computer-generated faces that varied in terms of trustworthiness. We recruited 30 individuals with WS and 30 chronological age-matched controls (mean age = 20 years). Each participant performed 80 trials (20 trials each of four face types: mildly and extremely trustworthy; mildly and extremely untrustworthy). We found that individuals with WS were significantly more likely than controls to choose to approach untrustworthy faces. In addition, the maximum deviation analysis demonstrated that even when ultimately choosing to avoid an untrustworthy face, the individuals with WS were more “tempted” than controls to deviate toward ‘Approach’ before deciding to ‘Avoid’ the face. We also found that the individuals with WS were more likely to choose to avoid trustworthy faces than controls, which might be associated with the neutral facial expressions displayed by the trustworthy faces. Both the WS and control participants were able to discriminate between mild and extreme degrees of trustworthiness and were more likely to make correct approachability decisions as they grew older. These findings increase our understanding of the cognitive processing that underlies approachability decisions in individuals with WS.
Upper-limb evolution and development.

The evolution of human forelimb structure is connected with changes in patterns of human behavior. Two complementary approaches—phylogenetic and functional—are used to analyze and understand these connections. The human forelimb is a mosaic of morphological features that reflect the evolutionary history of locomotor and manipulative behaviors. The phylogenetic approach identifies traits shared with and derived from other species. First, the general sequence of appearance of these features can be traced through a comparative process in which traits shared with other living and fossil species are identified. Some are shared exclusively with the closest relatives of humans, the chimpanzees, indicating their relatively recent appearance, whereas others, for example, the forelimb pattern of the humerus, radius, and ulna, are found among mammals, reptiles, amphibians, and certain fossil fish, indicating that the first appearance of the feature was in a common ancestor approximately 380 million years ago. Second, features unique to humans, termed derived features (indicating that they evolved following the divergence of humans from chimpanzees 6 to 7 million years ago) can be analyzed in order to construct a cladogram, or phylogenetic tree, with nodes representing hypothetical common ancestors of humans and living and fossil nonhuman groups, inferred from the shared elements of the human mosaic pattern (Fig. 1). These groups are increasingly inclusive toward the base of the cladogram; human-derived features evolved after node 6. Fig. 1 Cladogram with nodes representing inferred common ancestors of modern humans and fossil (italics) and living taxa with earliest evidence of forelimb features that are seen today in modern humans. mya = million years ago. The functional analytic approach involves linking the morphology of shared and derived traits to behavior. Evolutionary change in limb morphology occurred as locomotor and manipulative behaviors accommodated to changes in the ecology of successive groups of ancestral species. Functional changes in joint-movement …
Delineation of Borrelia burgdorferi p66 Sequences Required for Integrin αIIbβ3 Recognition

The outer membrane protein p66 of the Lyme disease agent, Borrelia burgdorferi, has been identified as a candidate ligand for beta(3)-chain integrins. To identify portions of p66 required for integrin recognition, fusions of maltose-binding protein to fragments of p66 were tested for binding to integrin alpha(IIb)beta(3), and synthetic peptides derived from the p66 amino acid sequence were tested for the ability to inhibit B. burgdorferi attachment to the same integrin. The data identify two noncontiguous segments of p66 that are important for alpha(IIb)beta(3) recognition, suggesting that, as is true for other integrin ligands, the tertiary structure of p66 is important for receptor recognition.
Failure case studies and ethics in engineering mechanics courses

Often, engineering students do not study engineering failures or discuss ethics until they take upper division undergraduate courses or graduate level courses. One drawback to this approach is that problems analyzed in introductory courses are often contrived, uninteresting, and bear little relation to the problems encountered in actual engineering practice. At the point when educators need to grab the student's interest in engineering most, they should show the excitement and relevance of the profession. Another drawback is that the students encounter the issues of ethics, responsibility, and accountability that are often highlighted by a failure, later in their engineering education. As a result, they may see these issues as secondary to engineering practice rather than fundamentally embedded. Examples of failure case studies and their incorporation into introductory engineering mechanics courses are discussed, along with ethical implications. When possible, problems should be selected so that the students can perform the calculations. By incorporating this material earlier in engineering education, it is possible to forge a stronger link between engineering education and practice.