cssi/SciSciGPT-SciSciNet huggingface dataset:
Transcatheter Aortic Valve Replacement in Mixed Aortic Valve Disease: A Systematic Review and Meta-analysis

BACKGROUND Utilization of transcatheter aortic valve replacement (TAVR) has expanded from high-risk patients to intermediate and select low-risk candidates with severe aortic stenosis (AS). TAVR is currently not indicated for patients with aortic insufficiency, and its outcomes in mixed aortic valve disease (MAVD) are unclear. METHODS A systematic search of PubMed, Medline, CINHAL and Cochrane databases was performed to identify studies comparing TAVR outcomes in patients with AS vs. MAVD. Primary outcomes included 30-day and late all-cause mortality, and paravalvular regurgitation (PVR). Secondary outcomes were major bleeding, vascular complications, device implantation success, permanent pacemaker and stroke. Pooled odds ratios (OR) and 95% confidence intervals (CIs) were calculated using Der Simonian-Laird random-effects model. RESULTS Six observational studies with 58,879 patients were included in the analysis. There was no significant difference in 30-day all-cause mortality (OR 1.03 [95% CI 0.92-1.15]; p = 0.63), however, MAVD group had higher odds of moderate to severe PVR (1.81 [1.41-2.31]; p<0.01). MAVD patients had lower odds of device implantation success (0.60 [0.40-0.91]; p = 0.02) while other secondary outcomes were similar in the two groups. CONCLUSIONS TAVR in MAVD is associated with increased odds of paravalvular regurgitation and lower odds of device implantation success when compared to severe aortic stenosis.
A Domain-Independent Holistic Approach to Deception Detection

The deception in the text can be of different forms in different domains, including fake news, rumor tweets, and spam emails. Irrespective of the domain, the main intent of the deceptive text is to deceit the reader. Although domain-specific deception detection exists, domain-independent deception detection can provide a holistic picture, which can be crucial to understand how deception occurs in the text. In this paper, we detect deception in a domain-independent setting using deep learning architectures. Our method outperforms the State-of-the-Art performance of most benchmark datasets with an overall accuracy of 93.42% and F1-Score of 93.22%. The domain-independent training allows us to capture subtler nuances of deceptive writing style. Furthermore, we analyze how much in-domain data may be helpful to accurately detect deception, especially for the cases where data may not be readily available to train. Our results and analysis indicate that there may be a universal pattern of deception lying in-between the text independent of the domain, which can create a novel area of research and open up new avenues in the field of deception detection.
Unconfined Aquifer Flow Theory: From Dupuit to Present

Analytic and semi-analytic solution are often used by researchers and practitioners to estimate aquifer parameters from unconfined aquifer pumping tests. The nonlinearities associated with unconfined (i.e., water table) aquifer tests make their analysis more complex than confined tests. Although analytical solutions for unconfined flow began in the mid-1800s with Dupuit, Thiem was possibly the first to use them to estimate aquifer parameters from pumping tests in the early 1900s. In the 1950s, Boulton developed the first transient well test solution specialized to unconfined flow. By the 1970s, Neuman had developed solutions considering both primary transient storage mechanisms (confined storage and delayed yield) without nonphysical fitting parameters. In the last decade, research into developing unconfined aquifer test solutions has mostly focused on explicitly coupling the aquifer with the linearized vadose zone. Despite the many advanced solution methods available, there still exists a need for realism to accurately simulate real-world aquifer tests.
Diffusion effects in eddy current nondestructive evaluation

Transducer response in nondestructive evaluation (NDE) requires fundamental knowledge of the field interaction with the material under test. Specifically, in eddy current NDE the transducer is an inductive coil or some combination of coils with an electromagnetic induction field surrounding the coil. The coil is used predominantly for surface or near-surface inspection of electrical conductors (metals). The change of impedance of the coil at its terminals is used as the criterion for defect detection. The impedance change due to a defect depends upon the relative disruption of the steady state field configuration in a given testing situation. A spatially smaller defect relative to the coil dimensions usually causes a smaller impedance change, therefore, it is more difficult to detect. The eddy currents induced in the metal by the exciting coil decay with distance into the metal due to energy loss in the form of Ohmic heating. Consequently, a defect easily detected at the surface with a given coil becomes undetectable at some distance beneath the metal surface. The distance at which a given defect becomes "invisible" is directly related to the rate of decay of the induced currents and their spatial distribution. The classical skin depth, bs = V2/wJ1.a, is the usual measure of the decay rate of currents in metals, but it is derived assuming a source field of infinite spatial extent and no inhomogeneity. In contrast, coils are often very small relative to the metal object under test and their useful fields are
H- and H 2 -matrix-based fast integral-equation solvers for large-scale electromagnetic analysis

Integral-equation (IE)-based methods generally lead to dense systems of linear equations. The resulting matrices, although dense, can be thought of as ‘data sparse’, that is, they can be specified by few parameters. Based on this observation, two fast IE-based methods were developed for large-scale electromagnetic analysis. One is a centre-point ℋ-matrix-based method of linear complexity for large-scale analysis of static problems or problems having small electric sizes. The other is an ℋ2-matrix-based method of controlled accuracy and linear complexity for large-scale analysis of electrodynamic problems across a wide range of electric sizes. Numerical simulations from a small number of unknowns to over 1 million unknowns, from small electric sizes to over 60 wavelengths have demonstrated the accuracy and efficiency of the proposed methods. The methods are kernel independent, and hence suitable for any IE-based formulation. In addition, they are applicable to arbitrarily shaped structures.
Current role of enzyme analysis for urea cycle disorders

Urea cycle disorders (UCD) are due to defects of any of its six enzymes or two transporters. The definitive diagnosis of defects of the three mitochondrial enzymes, N-acetylglutamate synthase (NAGS), carbamylphosphate synthetase I (CPS1) and ornithine transcarbamylase (OTC) depends on either molecular mutation analysis or measurement of enzyme activity, whereas the diagnosis of deficiencies of the three cytosolic enzymes argininosuccinate synthetase (ASS), argininosuccinate lyase (ASL) and arginase I (ARG1) is usually straightforward, based on marker metabolites. Enzyme assays for all UCD have been used since their first description, for disease confirmation and in some instances even for prenatal diagnosis. The genetic bases of the UCD have only been unraveled from the 1980s; the last gene cloned being the NAGS gene in 2002. In this review we discuss the enzymatic assays for all urea cycle enzymes from a historical perspective, their potential and drawbacks, and the current role of enzymatic analysis in UCD in general.
Model-based approaches to studying fertility and contraceptive efficacy

Statistical methods recently developed to aid in identifying environmental exposures with reproductive toxicity can also be applied to trials of interventions undertaken specifically to impair fertility, i.e. methods of contraception. Although only applicable in a trial that includes a reliable benchmark for identifying the day of ovulution, the proposed measures of contraceptive efficacy derived from such a trial offer certain interpretive advantages over the more traditional approaches of evaluating contraceptives. Extensions of the same models also allow one to evaluate efficacy under any assumed pattern of imperfect use. One can also evaluate methods based on biomarkers for the fertile phase of the cycle, such as hydration of the cervical mucus, that may prove to be enormously helpful to couples who wish to use periodic abstinence as their method. In prospective studies of fertility, couples who occasionally use a barrier method should not be excluded from the study, but can be retained, without biasing the estimates for fertility parameters.
Breastfeeding and Complementary Feeding of Children up to 2 Years of Age

Appropriate breastfeeding and complementary feeding practices are fundamental to children's nutrition, health, and survival during the first 2 years of life. The World Health Organization recommends exclusive breastfeeding until 6 months of age and continued breastfeeding for at least 2 years, along with the timely introduction of adequate amounts of complementary foods of suitable nutritional and microbiological quality. The amounts of energy and micronutrients required from complementary foods have been estimated as the difference between the total physiological requirements of these food components and the amounts transferred to the child in breast milk. Recommendations for the energy density of complementary foods and their frequency of feeding have also been proposed. Intakes of several micronutrients, including iron, zinc, calcium, selected B vitamins and (in some settings) vitamin A, remain problematic because commonly available, low-cost foods contain inadequate amounts of these nutrients to provide the shortfall in breast milk. Alternative strategies to provide these nutrients include adding animal source foods to the diet, providing fortified, processed complementary foods, administering micronutrient supplements, or offering some combination of these approaches. Advantages, disadvantages, and possible risks of these different strategies are discussed.
Pattern of organotin inhibition of methanogenic bacteria.

Seven organotin compounds and tin chloride were tested for their effects on the methanogenic bacteria Methanococcus thermolithotrophicus, Methanococcus deltae delta LH, and Methanosarcina barkeri 227. The methanogens were strongly inhibited by triethyltin, tripropyltin, and monophenyltin compounds, generally at concentrations below 0.05 mM. Less inhibition by tributyltin and diphenyltin was observed at levels below 0.1 mM, but complete inhibition was observed at a 1 mM concentration. Tin chloride inhibited all methanogens, with nearly complete inhibition at a 1 mM concentration. There was no inhibition by tetra-n-butyltin and triphenyltin compounds even at 2 mM, the highest concentration tested. The 50 and 100% inhibitory concentrations of all compounds were estimated; these values varied with both the compound tested and the bacterium tested. The 50% inhibitory concentration estimate generally decreased (i.e., giving a higher toxicity) as the total surface area of the alkyltin molecules decreased. These results differ considerably from those reported previously for aerobic microorganisms (G. Eng, E. J. Tierney, J. M. Bellama, and F. E. Brinckman, Appl. Organometallic Chem. 2:171-175, 1988), where a clear correlation between increasing total molecular surface area and increasing toxicity was documented with a variety of organisms. Using the same procedures as for the methanogens, we examined the effects of organotin compounds on Escherichia coli growing aerobically or anaerobically. The E. coli inhibition pattern clearly resembled that seen in the data of Eng et al., under both aerobic and anaerobic conditions.
Terrain Modeling for Autonomous Underwater Navigation

The main task of perception for autonomous vehicles is to build a representation of the observed environment in order to carry out a mission. in particular, terrain modeling, that is modeling the geometry of the environment observed by the vehicle's sensors, is crucial for autonomous underwater exploration. The purpose of this work is to analyze the components of the terrain modeling task, to investigate the algorithms and representations for this task, and to evaluate them in the context of real applications. Terrain representation is an issue that is of interest in many areas of mobile robotics, such as land vehicles, planetary explorers, etc. This paper surveys some of the ideas developed in those areas and their relevance to the underwater navigation problem. Terrain modeling is divided into three parts: structuring sensor data, extracting features, and merging and updating terrain models.
Preexposure of the Peritoneum to Live Bacteria Increases Later Mixed Intraabdominal Abscess Formation and Delays Mortality

Intraabdominal infections are a major source of morbidity and mortality for the trauma and postoperative patient. Transient peritoneal contamination with bacteria after either intentional or unintentional violation of the gut are common. The effect of this intermittent antigen exposure upon later formation of intraabdominal abscesses is unclear. Previous experiments by others have demonstrated that repeated exposure to Bacteroides fragilis capsular polysaccharide can induce a T lymphocyte-mediated immunity to subsequent induction of pure B. fragilis abscess formation. In a murine mixed intraabdominal abscess model, preexposure to live Escherichia coli, B. fragilis, or both increased the number of later abscesses and in some cases their bacterial composition. Further, immunization with E. coli alone increased late mortality without altering overall mortality. These data suggest that the alterations of immune function produced by live, transient bacteria upon subsequent mixed intraabdominal abscess induction result in fundamentally different consequences from those observed after specific polysaccharide antigen exposure and subsequent monomicrobial abscess induction.
What Kind of operators have few invariant subspaces

Abstract Elementary arguments are used to establish equivalent conditions for an operator on a finite dimensional space to have all invariant subspaces hyperinvariant.
A simulation study of computer-supported inferential analysis under data overload

A simulation study of inferential analysis was conducted with ten professional intelligence analysts. Using a process tracing methodology, patterns in vulnerabilities were identified when analysts were asked to analyze something outside their base of expertise, were tasked with a tight deadline, and had a large data set. First, study participants were vulnerable to missing critical information. All the participants were observed to use relatively primitive search tactics, quickly narrowing in on a set of documents through the addition of keywords to an initial query and then never conducting further searches. All of the participants missed some of the nine documents that were identified as high quality by the investigator. The group of four participants who found and relied upon some of the high quality documents took more time, read more documents, and made fewer inaccurate statements in their verbal briefings than the group of four participants who did not. Next, three sources of inaccurate statements by the study participants were identified. First, participants sometimes relied upon assumptions that would normally be correct, but did not apply in this situation. Second, participants sometimes repeated information that was inaccurate in a document that they had read. Strategies that were aimed at identifying and eliminating inaccuracies were generally resource-intensive and time-consuming, partly because the baseline electronic environment that was used in the study did not provide support for tracking conflicts in the data set. Third, participants were observed to rely upon information that was considered accurate at one point in time, but then was later overturned in subsequent updates. Locating updates is a very difficult task as they can be on themes that are not reflected in the date/title view of the documents in the browser window. At the broadest level, some of the study participants could be viewed as having prematurely closed the analysis process. There was a large variety in the rationales that were provided by the study participants for how they determined when to stop the analysis. Determining when to stop is difficult given that it is difficult to know what information has been missed—the judgment is based on the absence of information. The main contribution from this study is a model of potential vulnerabilities in inferential analysis under challenging conditions. These vulnerabilities are informative because they point to a set of challenging design criteria that human-centered solutions to data overload should meet in order to be useful. These evaluation criteria are interesting, in part, because they are so difficult to address. They are not amenable to simple, straightforward adjustments or feature additions to current tools. Meeting these design criteria will require innovative design concepts.
Situational Awareness for Dynamical Network Processes Using Incidental Measurements

Increasingly, incidental sensing capabilities are being leveraged for wide-area situational awareness of complex network processes. For instance, sensors embedded on miners' body suits are envisioned for sensing for chemical hazards, blog data is being used to track disease spread, and autonomous vehicle platforms can incidentally measure environmental conditions while engaging in mission tasks. This paper explores how sparse incidental measurements can be used in tandem with models for the network processes, to gain situational awareness. Specifically, we study reconstruction and forecasting of a network diffusion process by a single stochastically-transitioning observer (where the transition process is not necessarily Markov). Conditions are obtained on the observer's transition model and the diffusion process, such that the process state (scene) can be recovered from the incidental-measurement sequence. Additionally, the minimum-variance scene estimator and its performance are characterized, when the measurements are subject to additive white Gaussian noise. Two illustrative examples are also developed. The formal analyses and examples indicate that incidental measurements can permit effective reconstruction of network processes under broad conditions, albeit with some delay and error cost.
Preparation of Beating Heart Cells from Adult Rats

Suspensions of cardiac cells have been prepared from fragments of hearts from adult rats by prolonged incubation with trypsin and collagenase. In these preparations, about 50 percent of the viable cells routinely exhibit spontaneous contractions ranging from 20 to 120 beats per minute at room temperature. The contractile activity is essentially lost at 2°C but returns to normal as the temperature is increased. The rate of cellular contractions and the percentage of total cells exhibiting contractility are influenced by experimental conditions of cell preparation and the composition of the suspending medium.
Stochastic Simulation of Free Turbulent Premixed Flames in Isotropic Turbulence

A theoretical investigation of free turbulent permixed flames in isotropic turbulence is described, limited to the wrinkled thin laminar flamelet regime at neutrally-stable preferential diffusion conditions with negligible effects of quenching. The objective was to develop a computationally tractable three-dimensional time-dependent simulation of flame surface properties, capable of treating turbulence Reynolds numbers typical of experiments and practical flames. The approach involved statistical time series simulation of unburned gas velocities in conjunction with a flame advection and propagation algorithm. The following properties of the unburned gas were simulated, assuming that unburned gas turbulence properties were not affected by the flame: mean velocities due to volumetric expansion at the flame surface, and the Gaussian probability density functions and the spatial and temporal correlations of velocity fluctuations, while satisfying the requirement that cross correlations of velocity fluctuations are zero for isotropic turbulence. Predictions were evaluated using existing measurements for free flames propagating in hydrogen/oxygen/nitrogen mixtures having turbulence intensities relative to laminar burning velocities of 0.48–1.60 and turbulence Reynolds numbers of 1965–4195. Both two- and three-dimensional/time-dependent simulations yielded correct trends of measured flame surface statistics. This included the temporal variation of mean flame radius, r.m.s. flame radius fluctuations, and the average perimeter and fractal dimensions of the wrinkled flame surfaces for various relative turbulence intensities. However, performance of the two-dimensional simulation was less satisfactory because flame surface distortion by turbulence in one coordinate direction was suppressed. Additionally, the three-dimensional simulations underestimated effects of turbulence to some extent, a deficiency attributed to effects of volumetric expansion at the flame surface on unburned gas velocities, with approximations used to treat spatial and temporal correlations of velocity fluctuations in the unburned gas being possible contributing factors. Nevertheless, extension of the three-dimensional/time-dependent simulation to treat other flame configurations, as well as effects of quenching and preferential diffusion, appears to be warranted and is feasible due to the computational efficiency of the velocity simulation.
A characterization of triangle-free tolerance graphs

We prove that a triangle-free graph G is a tolerance graph if and only if there exists a set of consecutively ordered stars that partition the edges of G. Since tolerance graphs are weakly chordal, a tolerance graph is bipartite if and only if it is triangle-free. We, therefore, characterize those tolerance graphs that are also bipartite. We use this result to show that in general, the class of interval bigraphs properly contains tolerance graphs that are triangle-free (and hence bipartite).
Mass spectrometric characterization of mitochondrial electron transport complexes: subunits of the rat heart ubiquinol-cytochrome c reductase.

Complex III of the mitochondrial electron transport chain, ubiquinol-cytochrome c reductase, was isolated by blue native polyacrylamide gel electrophoresis. Ten of the 11 polypeptides present in this complex were detected directly by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) following electroelution of the active complex. Tryptic and chymotryptic digestion of the complex permit the identification of specific peptides from all of the protein subunits with 70% coverage of the 250 kDa complex. The mass of all 11 proteins was confirmed by second dimension Tricine sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and elution of the separated polypeptides. Additionally, the identity of the core I, core II, cytochrome c and the Rieske iron-sulfur protein were confirmed by liquid chromatography/tandem mass spectrometry (LC/MS/MS) characterization of the peptides generated by in-gel trypsin digestion of the SDS-PAGE separated proteins. The methodology demonstrated for analyzing this membrane-bound electron transport complex should be applicable to other membrane complexes, particularly the other mitochondrial electron transport complexes. The MS analysis of the peptides obtained by in-gel digestion of the intact complex permits the simultaneous characterization of the native proteins and modifications that contribute to mitochondrial deficits that have been implicated as contributing to pathological conditions.
Is lobular carcinoma in situ as a component of breast carcinoma a risk factor for local failure after breast-conserving therapy? Results of a matched pair analysis.

BACKGROUND The goals of the current study were to compare the clinicopathologic presentations of patients with lobular carcinoma in situ (LCIS) as a component of breast carcinoma who were treated with breast conserving surgery (BCS) and radiation therapy (RT) with those of patients without LCIS as part of their primary tumor and to report rates of local control by overall cohort and specifically in patients with positive margins for LCIS and multifocal LCIS. METHODS Sixty-four patients with Stages 0–II breast carcinoma with LCIS (LCIS-containing tumor group, LCTG) that had received BCS+RT treatment at the University of Michigan between 1989 and 2003 were identified. These patients were matched to 121 patients without LCIS (control group) in a 1:2 ratio. RESULTS The median follow-up time was 3.9 years (range, 0.3–18.9 yrs). There were no significant differences between the two groups with regard to clinical, pathologic, or treatment-related variables or in mammographic presentation, with the exception of a higher proportion of the LCTG patients who received adjuvant hormonal therapy (P = 0.01). The rates of local control at 5 years were 100% in the LCTG group and 99.1% in the control group (P = 0.86). The presence of LCIS at the margins and the size and presence of multifocal LCIS did not alter the rate of local control. CONCLUSIONS The extent of LCIS and its presence at the margins did not reduce the excellent rates of local control after BCS+RT. The data suggest that LCIS in the tumor specimen, even when multifocal, should not affect selection of patients for BCS and whole-breast RT. Cancer 2006. © 2005 American Cancer Society.
A machine-oriented resource management architecture

An architecture for resource management in a computer system is presented. The architecture is a subset of an APL-like higher level language machine architecture. The approach provides for a natural division of function between software and microcode/hardware. Any object in the system can be managed as a resource, and the fact that an object is managed can be transparent to the program using the object. Finally the resource management concepts are related to the current resource management problems of effective third-party control of resources, intelligent work scheduling, and deadlock resolutions.
Membrane Fouling and Molecular Weight Cutoff Effects on the Partitioning of Pectinesterase

The effects of membrane fouling and molecular weight cutoff (MWCO) on the partitioning of pectinesterase (PE) isolated from Marsh grapefruit were evaluated. Statistically higher fouling rates were observed for Marsh grapefruit extracts on 30K and 100K poly(sulfone) UF membranes than on a similar membrane with a MWCO of 10K. A simple logarithmic expression adequately described the fouling phenomena for all three UF membranes. The permeability of PE was also determined by using the same membranes and found to decrease 30−60% during processing regardless of the MWCO of the membrane. Permeability was found to decrease in a fashion similar to permeate flux. A separate logarithmic expression was developed to evaluate the rate of change of permeability on each of the membranes. About 40−50% of the total activity in the permeate of the 30K UF membrane was thermostable PE. Keywords: Polysulfone membrane; thermostable pectinesterase; citrus processing
Exploring Web-Based University Policy Statements on Plagiarism by Research-Intensive Higher Education Institutions

Plagiarism may distress universities in the US, but there is little agreement as to exactly what constitutes plagiarism. While there is ample research on plagiarism, there is scant literature on the content of university policies regarding it. Using a systematic sample, we qualitatively analyzed 20 Carnegie-classified universities that are “Very High in Research.” This included 15 public state universities and five high-profile private universities. We uncovered highly varied and even contradictory policies at these institutions. Notable policy variations existed for verbatim plagiarism, intentional plagiarism and unauthorized student collaboration at the studied institutions. We conclude by advising that the American Association of University Professors (AAUP) and other overarching academic bodies confer and come to accord on the disposition of these issues.
Effect of blocking on estimation of response surface

The conditions under which experimental trials are performed may not, in general, be homogeneous. However, it may be possible to achieve a greater degree of homogeneity by carying out limited groups—or block—of trials. In this case, when fitting a response surface model, the least squares estimates of the model's parameters will generally depend on how the response surface design is blocked. The purpose of this article is to demonstrate the effects of the blocks on estimating the mean response, on the prediction variance and on the optimum of the response surface. These are all shown to be affected by the sizes of the blocks and the allocation of experimental runs to the blocks. In particular, the prediction variance increases as a result of blocking. In the special case of an orthogonally blocked design, the least squares estimates of the fitted model's parameters remain unchanged by the block effect, except possibly for the intercept. The increase in the prediction variance in this case depends only on ...
The Stranger's Return: Strindberg, Kierkegaard, and Nietzsche

The biblical reference contained in its title has led many critics of August Strindberg's seminal drama, To Damascus, I, to regard only the religious influences in its content. This focus has tended often to ignore the substantial contributions of modern philosophy to the composition of Strindberg's work, especially in terms of dramatic structure and characterization. The following article traces and identifies the importance of Kierkegaard's Repetition and Nietzsche's Thus Spake Zarathustra - two philosophical narratives - for both the theme of the “stranger's return” and its rendering within the drama's symmetrical structure and typification of the dramatis personae.
Chromatin remodelling during development

New methods for the genome-wide analysis of chromatin are providing insight into its roles in development and their underlying mechanisms. Current studies indicate that chromatin is dynamic, with its structure and its histone modifications undergoing global changes during transitions in development and in response to extracellular cues. In addition to DNA methylation and histone modification, ATP-dependent enzymes that remodel chromatin are important controllers of chromatin structure and assembly, and are major contributors to the dynamic nature of chromatin. Evidence is emerging that these chromatin-remodelling enzymes have instructive and programmatic roles during development. Particularly intriguing are the findings that specialized assemblies of ATP-dependent remodellers are essential for establishing and maintaining pluripotent and multipotent states in cells.
CLP-type data validation guidelines for neutron activation analysis

Neutron activation analysis data quality must be validated to serve evidentiary purposes for environmental restoration and health protection projects. This paper gives a basis for determining the technical validity of neutron activation analysis data.
Adenyl cyclase stimulation by aspirin in rat gastric mucosa

ASPIRIN consumption is associated with gastric mucosal erosions1,2 and upper gastrointestinal haemorrhage3–5, and has been postulated as a factor in the development of chronic peptic ulcer6,7. It has been reported to cause chronic gastric ulcer in rats8. There is, however, no real understanding of the mechanism of these injuries. Menguy et al.9 suggested that the damage to the gastric mucosa results from lack of energy (ATP) for cell function. The reported antagonism of cholera enterotoxin by aspirin in the rat intestine10 might have been mediated through the inhibition of adenyl cyclase. We have now found, however, that aspirin can stimulate the activity of this enzyme in rat gastric mucosa.
The influence of natural and synthetic ligands on the transport and function of metal ions in the environment

ABSTRACT The environmental effects of coordination compounds are discussed from the point of view of the introduction of unnatural levels of metal ions and ligands into various parts of the ecosystem. The transport of toxic metals, with special reference to mercury, lead, and cadmium, is described, and the available information on the nature of these metals as they exist in the environment is examined. Consideration is given to the occurrence, constitution and properties of natural ligands in the environment. As a guide to the introduction of excessive ligands into the environment, the properties and uses of the ligands now in large scale commercial production are examined. Applications of EDTA, NTA, and sodium tripolyphosphate, all of which are used in large amounts, are considered in detail. An analysis of the current controversy over the substitution of NTA for tripolyphosphate in detergents indicates that NTA should be favoured for this large scale application and that the environmental impact of NTA should be minimal.
Nonlinear optical phenomena in fullerene-doped liquid crystal films and fibers

In this presentation, we shall describe the mechanisms and dynamics of two newly observed phenomena in fullerene C 60 doped liquid crystal, namely, holographic grating formation in thin film structures and nonlinear pulsed propagation and optical limiting in isotropic liquid crystal cored fibers and fiber arrays. The unusually large photorefractive like nonlinearity of C 60 doped nematic film allows us to write permanent holographic gratings which can be electronically modulated. In fullerene-doped liquid crystalline cored fibers, we have observed greatly enhanced nonlinear optical transmission and propagation effects caused by nonlinear scattering, defocusing, increasing absorption and possibly other nonlinear processes. The resulting lower threshold and reduced interaction-length requirement enable one to design practical liquid crystal fiber arrays that could function as imaging faceplate as well as sensor protection devices.
Natural partial fertilization in fasciolaria

Of the eggs laid by Fasciolaria about 1 per cent develop into veligers, about 2 per cent more undergo a few cleavage divisions, and about 97 per cent do not divide at all. The 99 per cent that fail to develop normally are ‘swallowed’ by the veligers. This study concerns itself chiefly with the ova that do not divide. Notes on normal development and on the ova that undergo atypical cleavage are included. All of the ova are found to be typical when passed from the ovary. To each ovum one to several sperms become attached at the vegetal pole in the region of a mass of undifferentiated protoplasm—the ‘polar mass.’ A fertilization cone forms in each ovum and a fertilization membrane. In typical development a yolk lobe is formed, the sperm enters in the usual way, and fertilization is completed as in many other mollusks. In 97 per cent of the ova the yolk lobe is not formed and the sperm does not enter. In these cases the wall of the egg nucleus remains intact a long time. The nucleus itself and the ‘polar mass’ sink into the egg and meet at the center. Then the nuclear wall disappears and an atypical diaster is formed. However, cleavage is not begun and the chromosomes form vesicles that remain near the center of the ovum until it is ‘swallowed’ and digested by the veliger.
Slow light and broadband coherent phonon generation

Recent advance in controlling optical forces using nanostructures suggests that nanoscale optical waveguides are capable of generating coherent acoustic phonons efficiently through a combination of radiation pressure and electrostriction. We discuss the critical roles of group velocity in such processes. This photon-phonon coupling would allow an acoustic intermediary to perform on-chip optical delay with a capacity 10 5 greater than photonic delay lines of the same size.
The Borsuk dimension of a graph and Borsuk's partition conjecture for finite sets

Borsuk's partition conjecture for finite subsets of euclidean space is placed in a graph theoretic setting and equivalent graph theoretic conjectures are raised. The Borsuk dimension of a graph is defined and the Borsuk dimensions of various graphs are tabulated.
Measurement Of The Recombination Lifetime In Semiconductor Lasers Using rf Techniques

Two techniques have been used for determining the recombination lifetime in semiconductor lasers: A capacitance bridge at 10 MHz, or a network analyzer in the range from 45 to 245 MHz. The latter, although more tedious than the former, has the advantage of allowing detection and inclusion of parasitic contributions. The AlGaAs ridge graded-index separate confinement heterostructure lasers studied here are well described by a simple equivalent circuit consisting of an ideal laser and a series resistance. Below threshold, the inverse lifetime squared exhibits a linear dependence on the forward current, as expected from simple theory. The measurements yield non-radiative lifetimes of 2.5 ... 5 ns. The bimolecular recombination constant B = 0.24 ... 0.56 x 10 -10 cm3/s is smaller than the bulk values; possible reasons are discussed.
UPTAKE AND RETENTION OF CESIUM 137 AND ZINC 65 BY SEAWEEDS1

Uptake and retention of Cs137 and Zn by seaweeds were observed under various environmental conditions. Concentration factors and biological half-lives varied widely among species, Zn65 showing generally higher levels of uptake and retention. No significant relationship between growth rate and either concentration factor or biological half-life was found among the species tested. Both uptake and loss of Cs137 were stimulated by light, but some Cs137 movements occurred in the dark. Both exogenous substrate (glutamate) and previous exposure to light stimulated Cs137 uptake in the dark. Exposure to nitrogen in the dark inhibited both influx and efflux of Cs137. Neither darkness nor anoxia caused appreciable net loss of absorbed Cs137. Cs137 was not extensively adsorbed by cell walls or killed tissue. Influx and efflux of Cs were proportional, respectively, to the external and internal Cs concentrations. Intracellular Cs appears to be largely ionic, with Cs movements being closely related to metabolism. Zn65 was highly concentrated by living and killed algae and by cell walls. Light had a variable effect on Zn65 movements. Zinc uptake at different external Zn concentrations agreed with the Freundlich adsorption equation. Adsorption exchange appears to be an important mechanism of Zn movements in seaweeds.
Brownfield Development: Tools for Stewardship

Brownfield development can be a “win-win” situation for the majority of the stakeholders that have an interest in the near- and long-term use of a currently unrealized asset. Further, brownfield development is a complex and time-consuming problem, only part of which is related to environmental concerns. Whereas there seems to be a flurry of brownfield development, both nationally and internationally, tools are lacking that can help to support complex decision making and ultimately expedite site remediation and development. In this research, we have collected data from 75 brownfields in the United States, analyzed the data to be able to distinguish “successful” from “not-so-successful” sites, and developed a logit model that may be used to estimate the probability of development outcomes. Much of the brownfield literature focuses on anecdote and qualitative descriptions of experiences. Therefore this research, which is based on empirical analyses, contributes to the literature by proposing a predictive model that may support rational decision making. Additionally, this research provides recommendations for application and improvement of the model.
Polarization characteristics of low-loss nano-core buried optical waveguides and directional couplers

The characteristics of a low loss buried optical waveguide with a nano-core-layer of SiN is analyzed. With such a low-loss optical waveguide, directional couplers are also designed, fabricated and characterized.
Identification of binding sites for members of the CCAAT/enhancer binding protein transcription factor family in the simian immunodeficiency virus long terminal repeat.

Abstract Members of the CCAAT/enhancer binding protein (C/EBP) transcription factor family are necessary for human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR) activity and viral replication in cells of monocyte/macrophage lineage. The integral roles that HIV-1-infected monocytes and macrophages play in the development and progression of HIV-1-associated disease in the immune and central nervous systems underscore the importance of the C/EBP transcription factor family within the context of regulating HIV-1 gene expression. Although there are considerable similarities between HIV-1 and simian immunodeficiency virus (SIV), including viral-induced immunopathogenesis and neurologic dysfunction, infection of CD4 + T cells and cells of monocyte/macrophage origin, and LTR structure/function, the involvement of C/EBP factors in regulating SIV transcription has not been previously demonstrated. Analyses of the SIV mac 239 LTR sequence indicated the presence of five putative C/EBP binding sites within the LTR. Electrophoretic mobility shift (EMS) analyses demonstrated that four of the five sites within the SIV LTR were able to bind C/EBP factors (α and β) and compete for DNA-protein complexes formed by the HIV-1 C/EBP site located adjacent to the promoter–distal NF-κB site. DNase I protection assays indicated that purified C/EBPβ specifically was able to occupy each of the four binding sites. These studies suggest that C/EBP factors may also have important roles in the regulation of SIV gene expression and replication, and that these factors and signal transduction pathways that regulate their activity may impact SIV-associated pathogenesis.
Mean life measurements using the beam foil light source.

A procedure for making quantitative measurements of the mean lives of electronic levels in beam foil-excited ions is described. Special emphasis is given to the theoretical equations that must be fitted to data and various beam particle monitoring techniques.
Collagen‐based structures containing the peptoid residue N‐isobutylglycine (Nleu): Synthesis and biophysical studies of Gly‐Pro‐Nleu sequences by circular dichroism, ultraviolet absorbance, and optical rotation

A peptoid residue N-isobutylglycine (Nleu) was introduced as a proline surrogate in collagen-like triple helical structures. A series of single chain and template-assembled collagen-based peptide-peptoid structures composed of Gly-Pro-Nleu sequences were prepared by solid-phase segment condensation methods. Both a synthetic route in solution and a solid phase method were employed to couple the KTA (cis,cis-1,3,5-trimethylcyclohexane-1,3,5-tricarboxylic acid, also known as the Kemp triacid) based template, KTA-(Gly-OH)3, to peptide-peptoid chains. Biophysical studies using CD, uv absorbance, and optical rotation measurements demonstrated that these compounds form triple-helical structures when the chains are longer than critical lengths. Results from melting curve measurements indicated that the Gly-Pro-Nleu sequence is comparable to the Gly-Pro-Pro sequence in stabilizing a triple-helical conformation. The KTA-based template stabilized triple-helical structures as can be seen by the increased melting temperatures as compared to equivalent single chain molecules. In addition, the template reduced the minimum chain length necessary to form a triple helix from six to only three trimer repeats. © 1996 John Wiley & Sons, Inc.
Board of Directors' Responsiveness to Shareholders: Evidence from Shareholder Proposals

Using a sample of 620 non-binding, majority-vote (MV) shareholder proposals between 1997 and 2004, we analyze the frequency, determinants and consequences of boards' implementation decisions. The frequency of implementation has almost doubled after 2002, reaching more than 40%. Shareholder pressure (e.g. the voting outcome and the influence of the proponent) and the type of proposals are the main determinants of the implementation decision, while traditional governance indicators do not seem to matter. Outside directors implementing MV shareholder proposals experience a one-fifth reduction in the likelihood of losing their board seat and in the likelihood of losing other directorships.
Functional roles for the slow afterhyperpolarization: inferences from incorporation of features of the slow gK+(Ca) into densely connected artificial neural networks

The functional significance of changes in the size of the afterhyperpolarization, observed in a range of neural contexts, has not been well characterized. Features of the slow afterhyperpolarization, driven by gK+(Ca), were accordingly incorporated into the elements of a densely connected, artificial neural network with a known computational function (autoassociation). The connections among its elements were specified so that the network without these features would respond to a stimulus with a sustained stimulus-specific spatial pattern of spiking. Large magnitudes of gK+(Ca) destabilized these stimulus-specific equilibria. Increases in the transmission delay between elements or in synaptic duration, however, preserved the stimulus-specific outputs of the networks at a corresponding magnitude of gK+(Ca). These simulations may have application to a broad range of topics: the timing of network outputs, accentuation of synaptic plasticity, roles for slow synaptic conductances and neuromodulation and the sel...
Microscope-enlarger for macrophotography of histological sections

A microscope-enlarger is described which can be used to produce 20 cm by 25 cm negatives of histological sections at magnifications up to 1,000 diameters, without loss of image quality or reduction of resolution. Standard flat-field microscope optics are used, and the apparatus is adjustable for Koehler illumination. Various microscope components (nosepiece, condenser carrier, etc.) are mounted upon carriers which ride upon a rigid vertical track. A 20 cm by 25 cm film holder is placed upon the base of the device, and illumination is controlled by a photographic timer. The microscope-enlarger has been used to produce large format negatives of Nissl-stained sections of the barins of sea lamprey larvae and to trace the course of Golgi-impregnated and cobalt-filled cells. Further uses of the device in autoradiographic and histochemical studies are mentioned.
Feedforward digital tracking controllers for motion control applications

This paper reviews digital tracking control algorithms for motion control applications. In tracking control, the control objective is to steer the control object along the time-varying desired output. Two design approaches are presented for the case where the desired signal is known in advance, i.e. previewable. One approach is based on the mathematical inverse of a closed-loop system consisting of a controlled plant and a feedback controller. If the mathematical inverse is asymptotically stable, i.e. the closed-loop system does not possess zeros outside the unit circle (unstable zeros), it is an ideal feedforward controller for achieving perfect tracking under the preview assumption. For closed-loop systems with unstable zeros, a cancellation technique for the phase shift induced by unstable zeros is introduced. Another approach is based on linear quadratic optimal control and is known as finite optimal preview control. In this approach, the feedback controller and feedforward controller are determined s...