cssi/SciSciGPT-SciSciNet huggingface dataset:
The Effect of Mandatory Information Disclosure on Financial Constraints

This paper studies the effects of the mandatory implementation of a more informative disclosure regime on firms’ financial constraints and investment policies. I run a difference-in-difference analysis and find that firms moving from a voluntary use of the regime to a mandatory use increase debt issuance and investment in tangible assets, and reduce the level of discussion about difficulties in obtaining debt financing. At the same time, they report higher difficulties obtaining external finance through equity. These findings support the hypothesis that mandatory disclosure provides a commitment device to future disclosure but shuts down the signaling value of voluntary disclosure.
Producing Masks Amid COVID-19? How A Pandemic Imprint Affects Firm's New Medical Production

We examine how corporate leaders’ prior pandemic experience influences their response to a later and similar pandemic. Drawing on imprinting theory, we argue that corporate leaders that experienced...
A Framework for Utilizing High Resolution Mass Spectrometry and Non-Targeted Analysis (NTA) in Rapid Response and Emergency Situations

Unknown chemical releases constitute a large portion of the rapid response situations to which the US Environmental Protection Agency is called on to respond. Workflows used to address unknown chemical releases currently involve screening for a large array of known compounds using many different targeted methods. When matches are not found, expert analytical chemistry knowledge is used to propose possible candidates from the available data, which generally includes low-resolution mass spectra and situational clues such as the location of the release, nearby industrial operations, and other field-reported facts. The past decade has witnessed dramatic improvements in capabilities for identifying unknown compounds using high-resolution mass spectrometry (HRMS) and non-targeted analysis (NTA) approaches. Complementary developments in cheminformatics tools have further enabled an increase in NTA throughput and identification confidence. Together with the expanding availability of HRMS instrumentation in monitoring laboratories, these advancements make NTA highly relevant to rapid response scenarios. In this article, we introduce the concept of NTA as it relates to rapid response needs and describe how it can be applied to address unknown chemical releases. We advocate for the consideration of HRMS-based NTA approaches to support future rapid response scenarios. Environ Toxicol Chem 2021;00:1-14. Published 2021. This article is a U.S. Government work and is in the public domain in the USA.
Dynamic Sub-graph Learning for Patch-Based Cortical Folding Classification

Surface mapping techniques have been commonly used for the alignment of cortical anatomy and the detection of gray matter thickness changes in Alzheimer’s disease (AD) imaging research. Two major hurdles exist in further advancing the accuracy in cortical analysis. First, high variability in the topological arrangement of gyral folding patterns makes it very likely that sucal area in one brain will be mapped to the gyral area of another brain. Second, the considerable differences in the thickness distribution of the sulcal and gyral area will greatly reduce the power in atrophy detection if misaligned. To overcome these challenges, it will be desirable to identify brains with cortical regions sharing similar folding patterns and perform anatomically more meaningful atrophy detection. To this end, we propose a patch-based classification method of folding patterns by developing a novel graph convolutional neural network (GCN). We focus on the classification of the precuneus region in this work because it is one of the early cortical regions affected by AD and considered to have three major folding patterns. Compared to previous GCN-based methods, the main novelty of our model is the dynamic learning of sub-graphs for each vertex of a surface patch based on distances in the feature space. Our proposed network dynamically updates the vertex feature representation without overly smoothing the local folding structures. In our experiments, we use a large-scale dataset with 980 precuneus patches and demonstrate that our method outperforms five other neural network models in classifying precuneus folding patterns.
Factoring in ℚ[x], III: mod M

One of the best methods currently available for factoring a polynomial with integer coefficients is to factor it mod M for M a large number and then try to “;lift” the factorization back to one in ℤ[x].
Price Change Causation Across International Stock Markets

This study investigatees whether and to what extent a causal relationship exists among international equity markets. Daily closing values from 1987 to 1989 for markets in New York, London, Tokyo, Toronto, Frankfurt and Hong Kong are examined using Geweke's extension of Granger's causality test. The results suggest that any groupings of five markets significantly influences the sixth market; however, with the exception of New York, individual markets do not causally influence the group. The failure of London and Tokyo to influence the groups from which they were excluded is interesting. Because these causal effects vary over time, it may be difficult to use these results for predictive purposes; nevertheless, this study should enhance understanding of pricing interactions across international stock markets.
Sturge–Weber syndrome

Introduction Sturge–Weber syndrome (SWS) is a rare neurocutaneous syndrome the main clinical features of which are facial, mostly unilateral nevi, leptomeningeal angiomatosis, and congenital glaucoma. The interest of this syndrome for pediatric neurosurgeons is mainly related to the association of SWS with epilepsy in 75–90% of the cases. Seizures are resistant to medical treatment in almost 60% of these patients that consequently should be evaluated for epilepsy surgery.
Thermodynamics of α-Chymotrypsin-Substrate and Inhibitor Complex Formation as a Function of pH HYDROPHOBIC BINDING BY THE LOW AND HIGH pH FORMS OF THE ENZYME

Abstract It has been shown that the pH dependence of the association constant for α-chymotrypsin-methyl hippurate complex formation is different from those of amide substrates and simple hydrocarbon inhibitors in that the values become constant at pH 9 and above. In addition, the association constant for naphthalene goes through a maximum at a pH of 7.5 to 7.8. No binding of the simple aromatic hydrocarbon inhibitors could be shown above pH 9. Evidence is presented which indicates that the alkaline form of the enzyme binds methyl hippurate primarily through the alcoholic moiety of the ester molecule, and that the hydrophobic binding site which is involved in binding the aromatic moiety of the substrate is no longer operative at high pH. Evidence is also presented that, in the case of methyl and isopropyl hippurate, acylation is the rate-governing step over the entire pH range studied. It is shown that either a carbonyl group or an aromatic nucleus is required for Ki for a competitive inhibitor to be pH dependent. Finally it is shown that ionic strength exerts a profound effect upon the pH dependence of both the association constant and kcat for methyl hippurate. At low ionic strength, the dependence of the association constant on pH is greatly decreased. It is suggested that one way of looking at pH dependence is in terms of the effect of pH on ionic strength effects.
Bandwidth-Constrained MAP Estimation for Wireless Sensor Networks

We deal with distributed parameter estimation algorithms for use in wireless sensor networks (WSNs) with a fusion center when only quantized observations are available due to power/bandwidth constraints. The main goal of the paper is to design efficient estimators when the parameter can be modelled as random with a priori information. In particular, we develop maximum a posteriori (MAP) estimators for distributed parameter estimation and formulate the problem under different scenarios. We show that the pertinent objective function is concave and hence, the corresponding MAP estimator can be obtained efficiently through simple numerical maximization algorithms
Autopsy Findings in Botulinum Toxin Poisoning

In the United States, foodborne botulism is most commonly associated with home-canned food products. Between 1950 and 2005, 405 separate outbreaks of botulism were reported to the Centers for Disease Control and Prevention (CDC). Approximately 8% of these outbreaks were attributed to commercially produced canned food products. Overall, 5-10% of persons ingesting botulinum toxin die. Few reports exist pertaining to autopsy findings in cases of foodborne botulism. Here, we report the autopsy findings of a man who died after a prolonged illness caused by botulinum toxin exposure likely attributable to a commercially prepared food source. Despite extensive testing, our histopathologic findings were nonspecific. We therefore conclude that the forensic pathologist must become familiar with the neurotoxicity syndrome associated with this illness. Maintaining vigilance for botulism by carefully reviewing the decedent's clinical history will aid in the early identification and control of outbreaks, either foodborne or terrorism-related.
Cycloheximide-induced apoptosis alters human neutrophil intracellular calcium metabolism and these effects are not reversed by cyclic-AMP exposure. 42

Cycloheximide-induced apoptosis alters human neutrophil intracellular calcium metabolism and these effects are not reversed by cyclic-AMP exposure. 42
Political factors in international economics: an overview

Abstract The intellectual interaction between politics and economics is not new. Theolder term to describe what economists do—political economy— which until recently survived only in French translation and on the masthead of one of the premier professional journals, is a case in point. A more pertinent example is provided by developments over the past two decades in the field of industrial organization, the shift from an exclusively public-interest view of economic regulation to one in which regulation is seen as the result of interaction between utility-maximizing politicians and various interest groups. 1 The extension of such ideas to international economics is, I believe, both necessary and desirable. And, as these papers indicate, with the right experimental design, it can also prove highly illuminating.
12-methylidene-10(Z), 13(Z)-nonadecadienoic acid, a new irreversible inhibitor of soybean lipoxygenase

Abstract Aerobic incubation of soybean lipoxygenase with 12-methylidene-10(Z, 13(Z-nonadecadienoic acid results in irreversible deactivation of the enzyme in a manner consistent with a recently proposed mechanism for lipoxygenation.
Dynamics of small amplitude, off-resonance AFM

Abstract Most current non-contact-atomic force microscopy (nc-AFM) techniques rely on vibrating the measuring lever at resonance using amplitudes that are large compared to typical interaction length scales. Here we present results of simulations that show that off-resonance, small amplitude AFM provides an alternative non-contact technique in which force gradients can be measured directly without the need of mathematical de-convolution. We show that under a wide range of reasonable conditions the measurements are linear and quantitative.
Behavioral and physiological studies of a convulsing mutant chicken (Gallus domesticus).

Female chicks carrying a recessive lethal, sex-linked gene designated px (paroxysm) develop seizures. In a population of px chicks (hemizygous females), the mean age of showing the first seizure is 19 days. The seizure syndrome can be generally divided into four phases: (1) alert phase (vocalization and/or running), (2) clonic phase (wing flapping, legs flex), (3) tonic phase (opisthotonos), and, (4) recovery phase. Seizures are spontaneous and recurrent but can also be precipitated by various environmental stimuli or by electrical stimulation of brain. Electroencephalogram recordings during seizures consistently show repetitive high amplitude spikes. Dilantin and sodium pentobarbital were effective in inhibiting electrically induced convulsions. No gross brain lesions were detected with light microscopy.
WTIP interacts with ASXL2 and blocks ASXL2-mediated activation of retinoic acid signaling.

The Asx-like (ASXL) family proteins are chromatin factors that play dual roles in transcriptional activation and repression. ASXL2 is highly expressed in the heart and is required for proper heart development and function. Here, we identify a novel ASXL2-binding partner, the LIM domain-containing protein WTIP. Genetic and biochemical assays show a direct interaction between ASXL2 and WTIP. In HeLa cells, ASXL2 enhances retinoic acid-dependent luciferase activity, while WTIP represses it. Furthermore, WTIP blocks ASXL2’s stimulatory effect on transcription. In addition, we found that ASXL2 and WTIP are expressed in mouse embryonic epicardial cells, a tissue that is regulated by retinoic acid signaling. Together, these results implicate ASXL2 and WTIP in regulation of retinoic acid signaling during heart development.
A comprehensive study of digital signal processing devices

Abstract Owing to the non-availability of high speed computing devices in the past, the implementation of numerically intensive digital signal processing (DSP) algorithms has been restricted to expensive computing systems within laboratories in non-real-time environments. This has dramatically changed during the last decade because of the introduction of DSP micros as a cost effective and easy solution to the problem. These versatile micros are special purpose microprocessors that manipulate electronic signals at extremely high speeds according to instructions delivered through software. A comprehensive study and discussion on these micros are the main themes of this manuscript. The study reveals various issues of these micros such as architectural overview, benchmarks, characteristics, configuration strategies, definitions, evolution, formulae and method of classification. The architecture of these devices has been changing rapidly to incorporate features giving them general purpose capabilities for the execution of any DSP algorithm in real-time.
Trichloroethylene effects on gene expression during cardiac development

Background: Halogenated hydrocarbon exposure is associated with changes in gene expression in adult and embryonic tissue. The present study was undertaken to identify differentially expressed mRNA transcripts in embryonic hearts from Sprague-Dawley rats exposed to trichloroethylene (TCE) or potential bio-transformation products of TCE, Dichloroethylene (DCE) and Trichloroacetic acid (TCAA). Methods: cDNA subtractive hybridization was used to selectively amplify expressed mRNA in either control or day 11 embryonic rat hearts exposed to one of these halogenated hydrocarbons from day 0 to 11. The doses used were 1100 and 110 ppm (8300 and 830 mu M) TCE, 110 and 11 ppm (1100 and 110 mu M) DCE, 27.3 and 2.75 mg/ml (100 and 10 mM) TCAA. Control animals were given distilled drinking water throughout the period of experiments. Results: Sequencing of over 100 clones derived from halogenated hydrocarbon exposed groups=resulted in identification of numerous differentially regulate gene sequences. Up-regulated transcripts identified include genes associated with stress response (Hsp 70) and homeostasis (several ribosomal proteins). Down-regulated transcripts include extracellular matrix components (GPI-p137 and vimentin) and Ca2 + responsive proteins (Serca-2 Ca2+-ATPase and beta-catenin). Two possible markers for fetal TCE exposure were identified: Serca-2 and GPI-p137, a GPI-linked protein of unknown function. Both markersmore » show a dose-related decrease in mRNA transcript levels associated with fetal exposure to TCE. Differential regulation of expression of both markers by TCE was confirmed by dot blot analysis and semi-quantitative RT-PCR. Levels of exposure between 100 and 250 ppb (0.76 and 1.9 mu M) TCE are sufficient to decrease expression of both the Ca2+-AT Pase and GPI-p137. Conclusion: Sequences down-regulated with TCE exposure appear to be those associated with cellular=housekeeping, cell adhesion and developmental processes, while TCE=exposure up-regulates expression of numerous stress response and homeostatic genes. Two potentially useful marker genes show a correlation between increasing levels of maternal TCE exposure and a decrease in marker transcript levels expressed at E11 in fetal rat heart tissue.« less
Sodium balance in the newt, Notophthalmus viridescens

Abstract 1. 1. Sodium fluxes in Notophthalmus viridescens were found to be higher than those of any amphibian examined to date. 2. 2. The total sodium loss from unfed animals was 49.4 μ-equiv/g/day, or ca . 102% of total body sodium/day. 3. 3. Integumental loss accounted for 68% of the total; urinary loss, 32%. 4. 4. Integumental sodium uptake exhibited saturation kinetics, with a J max = 234 μ-equiv/g/day and a k m = 2.1 m-equiv/l. 5. 5. The high capacity of the transport system allows losses to be replaced at external sodium concentrations approaching 0.1 m-equiv/l.
Potent inhibition of rhabdoid tumor cells by combination of flavopiridol and 4OH-tamoxifen.

Rhabdoid Tumors (RTs) are highly aggressive pediatric malignancies with poor prognosis. There are currently no standard or effective treatments for RTs in part because treatments are not designed to specifically target these tumors. Our previous studies indicated that targeting the cyclin/cdk pathway is a novel therapeutic strategy for RTs and that a pan-cdk inhibitor, flavopiridol, inhibits RT growth. Since the toxicities and narrow window of activity associated with flavopiridol may limit its clinical use, we tested the effect of combining flavopiridol with 4-hydroxy-Tamoxifen (4OH-Tam) in order to reduce the concentration of flavopiridol needed for inhibition of RTs. The effects of flavopiridol, 4OH-Tam, and their combination on RT cell cycle regulation and apoptosis were assessed by: i) cell survival assays, ii) FACS analysis, iii) caspase activity assays, and iv) immunoblot analysis. Furthermore, the role of p53 in flavopiridol- and 4OH-Tam-mediated induction of cell cycle arrest and apoptosis was characterized using RNA interference (siRNA) analysis. The effect of p53 on flavopiridol-mediated induction of caspases 2, 3, 8 and 9 was also determined. We found that the combination of flavopiridol and 4OH-Tam potently inhibited the growth of RT cells. Low nanomolar concentrations of flavopiridol induced G2 arrest, which was correlated to down-modulation of cyclin B1 and up-regulation of p53. Addition of 4OH-Tam did not affect flavopiridol-mediated G2 arrest, but enhanced caspase 3,7-mediated apoptosis induced by the drug. Abrogation of p53 by siRNA abolished flavopiridol-induced G2 arrest, but enhanced flavopiridol- (but not 4OH-Tam-) mediated apoptosis, by enhancing caspase 2 and 3 activities. Combining flavopiridol with 4OH-Tam potently inhibited the growth of RT cells by increasing the ability of either drug alone to induce caspases 2 and 3 thereby causing apoptosis. The potency of flavopiridol was enhanced by abrogation of p53. Our results warrant further studies investigating the combinatorial effects of flavopiridol and 4OH-Tam as a novel therapeutic strategy for RTs and other tumors that have been shown to respond to flavopiridol.
RRR: A Load Balanced Routing Scheme for Slimmed Fat-Trees

Fat-trees are widely adopted in HPC systems. While existing static routing schemes such as destination-mod-k (D-mod-k) routing are load-balanced and effective for full bisection bandwidth fat-trees, they are not load-balanced for many slimmed fat-trees, which have recently been suggested to reduce costs in HPC systems. In this work, we propose a load balanced routing scheme, called Round-Robin Routing (RRR), for 2- and 3-level extended generalized fat-trees (XGFTs), which represent many fat-tree variations including slimmed fat-trees. RRR achieves near perfect load-balancing for any such XGFT in that links at the same level of a tree carry traffic from almost the same number of source-destination pairs. Simulation results show that on many slimmed fat-trees, RRR is significantly better than D-mod-K for majority of traffic patterns.
State mandatory overtime regulations and newly licensed nurses’ mandatory and voluntary overtime and total work hours

Nurse overtime has been used to handle normal variations in patient census and to control chronic understaffing. By 2010, 16 states had regulations to limit nurse overtime. We examined mandatory overtime regulations and their association with mandatory and voluntary overtime and total hours worked by newly licensed registered nurses (NLRNs). For this secondary data analysis, we used a panel survey of NLRNs; the final dataset consisted of 1,706 NLRNs. Nurses working in states that instituted overtime regulations after 2003 or in states that restricted any type of mandatory overtime had a lower probability of experiencing mandatory overtime than those nurses working in states without regulations. Nurses who worked in states with mandatory overtime regulations reported fewer total hours worked per week. The findings of this study provided insight into how mandatory overtime regulations were related to nurse mandatory and voluntary overtime and the total number of hours worked. Future research should investigate institutions' compliance with regulations and the impact of regulations on nurse and patient outcomes.
Evaluation of a reflective polymer film for heliostats

Abstract Commercially available Solar Mirror Film (SMF) 1100 from 3M was evaluated for application in concentrating solar power tower applications, where large arrays of heliostats are used to reflect and concentrate sunlight toward a central receiver at potentially large distances. The reflectance and soiling rate of SMF1100 was compared to silvered glass mirrors during outdoor exposure for over a year. In addition, the reflected beam quality and peak flux resulting from solar reflections from SMF1100 and silvered glass facets at distances up to ∼1700 m were compared. Results showed that the impacts of soiling and outdoor exposure on the solar-weighted reflectance of coupons of SMF1100 did not differ significantly from that of silvered glass over a year of testing. However, the initial (clean) specular reflectance (at 660 nm) of SMF1100 was found to be ∼2–4% lower than that of silvered glass for acceptance angles ranging from 25 mrad to 15 mrad, which contributed to a lower overall heliostat beam power projected onto the tower ∼200 m away when compared to an adjacent heliostat with silvered glass. The peak flux was measured from individual facets with SMF1100 and silvered glass at distances up to ∼1700 m. Slight differences existed in the focal length, specular reflectance, and time of testing of the individual facets, but results showed that the mean of the measured peak fluxes (normalized to the direct normal irradiance at the time of testing) of the SMF100 and silvered glass facets were statistically similar.
Legal Limits on Labor Militancy: U.S. Labor Law and the Right to Strike since the New Deal

Since passage of the Wagner Act in 1935, U.S. labor law has guaranteed workers the right to strike. Three years later, the same system of law assured the employer's right to continue production in spite of a strike. This paper explores how the Wagner Act and its subsequent developments have simultaneously empowered workers and constrained their collective capacity to exercise control over the workplace. Historical legal analysis of Wagner and its applications, interpretations, and amendments indicates that the law has diminished the effectiveness of the strike, reduced the likelihood of its occurrence, and limited its legitimate forms, all the while sustaining the right to strike. I argue that by this careful balance of empowerment and constraint, the state has found the means of reconciling the structural constraints of capitalism—the imperatives of accumulation—with those of democracy— the demands of legitimacy.
Sensory Evaluation of Muffins Prepared With Wheat Germ Substitution for Bran to Increase Magnesium

Abstract This study was conducted to evaluate how the substitution of wheat germ for bran in muffins affects the magnesium content, taste, texture and appearance. Six variations of wheat germ were tested: a control product with 100% bran (C), a 75% bran 25% wheat germ (75B25G), a 50% bran 50% wheat germ (50B50G), a 25% bran 75% wheat germ (25B75G), a 100% wheat germ (G), and a 200% wheat germ (200G). Preference was assessed by sensory evaluation. The evaluation was rated on a scale of: 1=excellent, 3=neutral, 5=extremely poor. The overall acceptance in the G and C were significantly higher than 75B25G (p
Spike phase precession persists after transient intrahippocampal perturbation

Oscillatory spike timing in the hippocampus is regarded as a temporal coding mechanism for space, but the underlying mechanisms are poorly understood. To contrast the predictions of the different models of phase precession, we transiently turned off neuronal discharges for up to 250 ms and reset the phase of theta oscillations by stimulating the commissural pathway in rats. After recovery from silence, phase precession continued. The phase of spikes for the first theta cycle after the perturbation was more advanced than the phase of spikes for the last theta cycle just before the perturbation. These findings indicate that phase advancement that emerges within hippocampal circuitry may be updated at the beginning of each theta cycle by extrahippocampal inputs.
INCORPORATING SUBGRADE LIME STABILIZATION INTO PAVEMENT DESIGN

The benefits of subgrade lime stabilization are incorporated, for the first time, into the design of a major interstate highway pavement in Pennsylvania. The project comprises widening and complete reconstruction of 21 km of the Pennsylvania Turnpike in Somerset County. Field explorations indicated that the subgrade is fairly homogeneous and consists primarily of medium to stiff clayey soils. To safeguard against potential softening due to rain, lime modification has been traditionally utilized as a construction expedience for highway projects with clayey subgrade. Such an approach, however, does not take advantage of the added strength of the lime-stabilized subgrade in pavement design. Lime improves the strength of clay by three mechanisms: hydration, flocculation, and cementation. The first and second mechanisms occur almost immediately upon introducing the lime, and they have been investigated in the study; the third is a prolonged effect. Laboratory tests were performed to accurately capture the immediate benefits of lime stabilization for design. Both treated and natural clayey samples were subjected to resilient modulus and California bearing ratio testing. To prevent cementation, the lime-treated specimens were not allowed to cure. Nevertheless, they showed significant increases in strength, which, when incorporated into design, reduced the pavement thickness and resulted in substantial savings.
cornichon and the EGF receptor signaling process are necessary for both anterior-posterior and dorsal-ventral pattern formation in Drosophila

In Drosophila, the dorsal-ventral polarity of the egg chamber depends on the localization of the oocyte nucleus and the gurken RNA to the dorsal-anterior corner of the oocyte. Gurken protein presumably acts as a ligand for the Drosophila EGF receptor (torpedo/DER) expressed in the somatic follicle cells surrounding the oocyte. cornichon is a gene required in the germline for dorsal-ventral signaling. cornichon, gurken, and torpedo also function in an earlier signaling event that establishes posterior follicle cell fates and specifies the anterior-posterior polarity of the egg chamber. Mutations in all three genes prevent the formation of a correctly polarized microtubule cytoskeleton required for proper localization of the anterior and posterior determinants bicoid and oskar and for the asymmetric positioning of the oocyte nucleus.
Conservative difference formulations of Calogero and Toda Hamiltonian systems

Abstract Calogero and Toda Hamiltonian systems are reformulated using only differences. The formulations prove to have the same fundamental invariants as the continuous systems and, in addition, are readily implementable on modern digital computers.
An essential role for postsynaptic calmodulin and protein kinase activity in long-term potentiation

THE phenomenon of long-term potentiation (LTP), a long lasting increase in the strength of synaptic transmission which is due to brief, repetitive activation of excitatory afferent fibres, is one of the most striking examples of synaptic plasticity in the mammalian brain. In the CA1 region of the hippocampus, the induction of LTP requires activation of NMDA (N-methyl-D-aspartate) receptors by synaptically released glutamate1 with concomitant postsynaptic membrane depolarization2-5. This relieves the voltage-dependent magnesium block of the NMD A-receptor ion channel6,7, allowing calcium to flow into the dendritic spine8-10. Although calcium has been shown to be a necessary trigger for LTP (refs 11,12), little is known about the immediate biochemical processes that are activated by calcium and are responsible for LTP. The most attractive candidates have been calcium/cal-modulin-dependent protein kinase II (CaM-KII) (refs 13-16), protein kinase C (refs 17-19), and the calcium-dependent protease, calpain20. Extracellular application of protein kinase inhibitors to the hippocampal slice preparation blocks the induction of LTP (refs 21-23) but it is unclear whether this is due to a pre- and/or postsynaptic action. We have found that intracellular injection into CA1 pyramidal cells of the protein kinase inhibitor H-7, or of the calmodulin antagonist calmidazolium, blocks LTP. Further-more, LTP is blocked by the injection of synthetic peptides that are potent calmodulin antagonists and inhibit CaM-KII auto- and substrate phosphorylation. These findings demonstrate that in the postsynaptic cell both activation of calmodulin and kinase activity are required for the generation of LTP, and focus further attention on the potential role of CaM-KII in LTP.
Marine nutrient contributions to freshwater apex predators.

Recent investigations into the nutrient cycling of coastal ecosystems have suggested that migratory or anadromous fish could be important vectors of marine nutrients. Anadromous fish have assimilated marine nutrients that would contribute to the nutrient budgets of freshwater systems by excretion, gamete release, or the decay of post-reproductive carcasses. However, the extent to which freshwater predators utilize marine material is not well understood. In systems where anadromous fish temporarily constitute a major portion of the fish community, they may contribute substantially to the diet of piscivorous fish and other predators. Here we show the contribution of anadromous blueback herring, shad, and alewife (Alosa) to diets of large, non-indigenous piscivorous catfish (Ictalurus furcatus) using δ34S and δ13C. The spawning anadromous Alosa, captured in tidal freshwater, had enriched δ34S and δ13C values compared to resident, native freshwater species. As a result of consuming the anadromous Alosa, the I. furcatus isotope signature shifted towards the marine signal. The isotope analysis revealed that anadromous fish contribute substantially to the diet of most captured I. furcatus. The percentage of anadromous Alosa carbon and sulfur that was incorporated into I. furcatus (≥38 cm total length) ranged from 0 to 84% and 10 to 69%, and had means (±SD) of 42 (±24) and 43 (±16)%, respectively. Although the δ15N signal of marine-derived biomass is enriched by approximately 3‰ relative to terrestrial or freshwater biomass, it was not as useful as δ34S and δ13C for nutrient source owing to trophic fractionation. This study demonstrates that anadromous fish may be a significant source of nutrients to tidal freshwater apex predators.
The Zebrafish Cornea: Structure and Development

PURPOSE. To evaluate the zebrafish as a model for the studies of corneal development and disease. METHODS. Zebrafish embryos and larvae at various stages of development were used for documenting corneal morphogenesis and differentiation. Corneal samples were collected from embryos, larvae, and adult zebrafish for histologic and electron microscopy analysis. Expression patterns of corneal polypeptides were investigated by immunostaining of sections. RESULTS. The zebrafish cornea develops rapidly during embryogenesis, so that its three major layers, the epithelium, the stroma, and the endothelium, are well formed by day 3 postfertilization. The subsequent steps of corneal differentiation, such as the thickening of the corneal stroma, proceed relatively slowly. Several polypeptides are highly enriched in the epithelium or the stroma of the larval and adult zebrafish cornea and are excellent markers of corneal differentiation. CONCLUSIONS. Development and differentiation of the zebrafish cornea are easily accessible to analysis. Anatomic and ultrastructural characterization of the zebrafish cornea demonstrates many similarities to the human cornea and provides the basis for the use of the zebrafish model both to analyze the basic genetic mechanisms of corneal development and to study the causes of comeal disease.
Polymer science and technology: An industrial perspective☆

Throughout my more than 40 years’ association and fascination with chemistry, I have been amazed at the value for society this science continues to provide. The promise for the future is truly spectacular. Clothing, shelter, food, transportation, electronics, superconductivity, information storage, the environment, medical progress, i.e. just about everything that is needed to advance the planet’s and its inhabitants’ well being, is inexorably dependent on and enabled by evermore elegant chemistry. And, more often than not, that chemistry is aimed at new or modified polymeric structures.
Major Questions about Derivation of Variance-Covariance Information for Nuclear Data Evaluations

The uncertainties in and correlations among some nuclear data are now evaluated to permit estimation of data-related uncertainties in the outputs of neutronic calculations and to focus data improvement efforts. Questions are discussed that arise in trying to obtain adequate numerical files of variance-covariance uncertainty information. These involve 1) discrepant data, 2) experimental data with incompletely reported uncertainties, 3) uncertainties in nuclear model results, 4) uncertainty data for the resonance regions and for angle and energy distributions, and 5) the role of integral data in nuclear data evaluation. The question also arises whether files of uncertainty data designed for technological applications can suffice to represent past knowledge in an evaluation that includes new data. Directions are indicated toward resolving these questions.
Laboratory Biology and Rearing of Tetrastichus brevistigma (Hymenopera: Eulophidae), a Larval-Pupal Parasitoid of the Elm Leaf Beetle (Coleoptera: Chrysomelidae)

Tetrastichus brevistigma (Gahan) parasitized last in stars, prepupae, and pupae of the elm leaf beetle, Xanthogaleruca (=Pyrrhalta) luteola (Muller). Although T. brevistigma is deuterotokous with males constituting 3.1% of field samples, males were never observed in 21 generations reared in the laboratory. Mean longevity (±SEM) at a 15:9 (L:D) photoperiod and 25 was 21 ± 0.76d. Mean fecundity (±SEM) was 144 ±7.9 offspring. Percentage of parasitization and the number of parasitoids produced per host decreased when elm leaf beetle pupae were older than 72 h. Diapause was 3, 4, 72.5, and 46.7% at 15:9, 14:10, 13: 11, and 12:12 (photo: scotophase), respectively. The photosensitive stage of T. brevistigma appears to be the egg or first in star. Parasitized pupae could be stored at 2°C for 30 d without affecting emergence of T. brevistigma . Feasibility of mass rearing T. brevistigma is discussed.
Molecular Mimicry as a Mechanism of Autoimmune Disease

A variety of mechanisms have been suggested as the means by which infections can initiate and/or exacerbate autoimmune diseases. One mechanism is molecular mimicry, where a foreign antigen shares sequence or structural similarities with self-antigens. Molecular mimicry has typically been characterized on an antibody or T cell level. However, structural relatedness between pathogen and self does not account for T cell activation in a number of autoimmune diseases. A proposed mechanism that could have been misinterpreted for molecular mimicry is the expression of dual T cell receptors (TCR) on a single T cell. These T cells have dual reactivity to both foreign and self-antigens leaving the host vulnerable to foreign insults capable of triggering an autoimmune response. In this review, we briefly discuss what is known about molecular mimicry followed by a discussion of the current understanding of dual TCRs. Finally, we discuss three mechanisms, including molecular mimicry, dual TCRs, and chimeric TCRs, by which dual reactivity of the T cell may play a role in autoimmune diseases.
Applications of nonaqueous colloids

Abstract Four high technology applications of nonaqueous colloids are reviewed. These include magnetic recording, electronic ceramics, reprographics and display devices. Colloidal interactions in nonaqueous media are summarized and related to basic technological requirements. Technological and scientific challenges are analyzed and a prognosis made for each technology.
Clinical impact of lymphadenectomy extent in resectable esophageal cancer.

Esophageal cancer (EC) frequently presents with advanced stages and is associated with high recurrence rates after esophagectomy. The value of an extended lymph node dissection (ELND) remains unclear in this setting. An EC data set was created from the Surveillance, Epidemiology, and End-Results 1973–2003 database. Relationships between the number of lymph nodes (LNs) examined and overall survival (OS) were analyzed. From a cohort of 40,129 EC patients, 5,620 individuals were selected. The median age was 65 (range: 11–102), and 75% were men. The median tumor size was 5.0 cm (0.1–30). On multivariate analysis, total LN count (or negative LN count, respectively) was an independent prognostic variable, aside from age, race, resection status, radiation, T category, N category (all at p 30) and negative LN count (>15) categories were associated with best OS and lowest 90-day mortality (p < 0.0001). The numeric LN effect on OS was independent from nodal status or histology. Greater total and negative LN counts are associated with longer EC survival. Although the mechanism remains uncertain, it does not appear to be limited to stage migration. ELND during potentially curative esophagectomy for EC can be supported by the data.
Kopf-Seitenairbag bei Fahrzeugüberschlägen

Spaetestens im September 2017 muessen Kraftfahrzeuge in den USA das FMVSS-226-Gesetz erfuellen. Mit der neuen Regelung soll der Insassenschutz bei Fahrzeugueberschlaegen verbessert werden. Zentrale Komponente ist dabei der Kopfairbag, der das Herausschleudern der Insassen aus den Seitenfensteroeffnungen verhindern soll. Je groesser das Seitenfenster, umso schwerer ist es fuer den Kopfairbag, den Rueckhalt zu gewaehrleisten. Das Pruefverfahren schreibt zwei Versuchskonstellationen vor, die einen fruehen und einen spaeten Zeitpunkt bei einem realen Fahrzeugueberschlag darstellen. Die hierzu vorgeschriebenen Impaktorpruefungen erfolgen mit 20 km/h bei 1,5 s und mit 16 km/h bei 6 s nach Airbagzuendung. Der Impaktor darf bei der Pruefung das Fahrzeug, gemessen von der Innenflaeche der Seitenscheibe, maximal 100 mm verlassen. Ist dies bei allen ermittelten Positionen und beiden Versuchskonstellationen der Fall, so erfuellt das Fahrzeug die Anforderungen. Mit der Kombination verschiedener Massnahmen sind die Gesetzesanforderungen mit Kopf-Seitenairbags erfuellbar. Als wichtigstes Merkmal hat sich neben der Luftsackgestaltung die Dichtheit des Gesamtsystems herausgestellt. Die Hoehe des Airbaginnendrucks nach 6 s ist entscheidend fuer die Erfuellung der Anforderungen. Der Einsatz von modernen Entwicklungsmethoden ermoeglicht eine schnelle und gezielte Entwicklung fuer jeden individuellen Fahrzeugtyp. Takata hat bereits erste FMVSS-226-taugliche Kopf-Seitenairbags in Produktion und weitere in der Entwicklung.
Mechanisms of platelet function as revealed by the retention of platelets in glass bead columns.

Summary In von Willebrand's disease, the only in vitro abnormality of platelet function is reduced retention of platelets in glass bead columns. Although this finding suggests that the test reflects an important function in normal hemostasis, its mechanism is poorly understood. The method developed by Bowie and colleagues7 has been used to elucidate some of the variables affecting the test. Heparinized blood is passed rapidly through the column and the percentage of platelets retained in the fourth and fifth ml is calculated. In normal subjects, more than 90% is usually retained. Disturbing the blood markedly decreases retention. Retention spontaneously returns to normal in about 45 minutes after disturbance or within ten minutes after addition of apyrase. Addition of 0.1 μM ADP decreases retention with a maximum effect at ten minutes. The lowered retention caused by disturbing blood appears to result from ADP probably sequestered in the platelet membrane. Slow centrifugation and remixing of blood also reduces retention which is restored by apyrase. Platelets in platelet-rich plasma are not retained in the column even after incubation with apyrase or apyrase plus adenosine deaminase, or after adding ADP. Adding red cell ghosts to platelet-rich plasma improves retention, although not as effectively as erythrocytes. Since ghosts contain virtually no ADP, it is suggested that they act by altering hemodynamics, either causing platelets to enter the marginal zone of plasma so that they contact the beads and tubing, or increasing the turnover of plasma in this zone to permit greater interaction of plasma components with the foreign surfaces.
Quantitative correlations of deviations from ideality in binary and pseudobinary solid solutions

Abstract Deviations from ideal mixing in a number of isostructural binary solid solutions are parameterized using regular and subregular thermodynamic mixing models. Linear correlations between calculated interaction parameters and a term representing the volume mismatch of the two end-members are obtained. These correlations apply to a wide variety of structure types and are found to segregate the solid solutions according to the valence of the ions being mixed. Alkali halide systems show smaller relative deviations than oxide and chalcogenide systems. The ratio of the slopes of these correlations agree with predictions made from consideration of the effective charges of the ions being mixed. The correlations are used to predict the variation of critical temperature, and composition, as a function of component volume mismatch. Calculations of the free energies of transformation of rock salt to nickel arsenide structures and of wurtzite/sphalerite (fourfold coordination) to rock salt/nickel arsenide (six-fold coordination) structures are made using the interaction parameters predicted by the correlations and observed terminal solid solubility data.
Singlet oxygen oxidation of methyl linoleate: Isolation and characterization of the NaBH4-reduced products

The mixture of diene hydroperoxides from methylene blue-sensitized oxidation of methyl linoleate was reduced with NaBH4 and the resulting alcohols were separated by high pressure liquid chromatography (HPLC). Four diene alcohols were isolated in approximately equal yields from adsorption and reversed phase HPLC; the isomers were identified as methyl esters of 9-hydroxy-10,12-, 10-hydroxy-8,12-, 12-hydroxy-9,13- and 13-hydroxy-9,11-octadecadienoate. Formation of equal yields of both conjugated and nonconjugated diene alcohols from methyl linoleate is characteristic of singlet oxygen oxidations. The detection of the easily separated nonconjugated isomer methyl 10-hydroxy-trans-8,cis-12-octadecadienoate from methyl linoleate is proposed as a test to probe the involvement of singlet oxygen in biological oxidations.
Lexical Elaboration in Children's Locative Action Expressions.

The spatial locative words used in multiword locative action expressions were tracked longitudinally for 4 children. Children ranged in age from 1–5 to 3–0. Although certain words emerged before others, as previous research has shown, the children were selective about which lexical categories were used to talk about movement events, and their selections changed systematically with age. Source and path words were used most frequently at the earliest ages, and goal words predominated at the oldest ages. The children also increased the specificity with which they talked about locative movement events by combining goal words with source and path words as they got older. The observed developmental shifts in lexical use suggest that lexical acquisition is influenced not only by the meaning of the individual locative words but also by the verb relational roles that such words play when embedded in semantic/syntactic contexts.
Vitroctomy for Macular Pucker

Abstract Vitreous surgery was used to treat 130 consecutive cases with epiretinal membranes causing macular pucker. The membrane: (1) occurred after otherwise successful retinal reattachment surgery in 78 eyes (60%), (2) was idiopathic in 28 eyes (22%), (3) was associated with other ocular disorders in 20 eyes (15%), and (4) in four eyes may have been developmental. The abnormal tissue was successfully removed in 128 of 130 eyes, and vision improved at least two lines on the Snellen chart in 108 eyes (83%). Postoperative visual acuity was 20/20 in five eyes (4%), 20/25 to 20/40 in 41 eyes (31.5%), 20/50 to 20/100 in 64 eyes (49%), 20/200 in 15 eyes (11.5%), and 20/400 in five eyes (4%). Complications included one case of sterile endophthalmitis and one case of infective endophthalmitis (Staphylococcus epidermidis). Peripheral retinal tears occurred in six eyes (5%). No posterior retinal breaks occurred in this series. Later retinal detachment occurred in eight eyes (6%) requiring further retinal surgery. Progressive postoperative nuclear sclerotic lens changes occurred in 31 (34%) of 90 phakic eyes. Sizable amounts of epiretinal tissue recurred postoperatively in four eyes (3%).
The interaction between curvature and lateral shear vorticities in a mean and an instantaneous Florida Current, a comparison

The question of how much of the dynamics of an instantaneous current is retained in the dynamics of a model derived from its mean structure is considered in terms of a comparison between two case studies of the Florida Current. In the mean model, fluid elements are restrained from crossing the speed axis. But in an observation of an instantaneous current there was an interaction between curvature and lateral shear vorticities accompanied by a systematic movement of fluid elements across the speed axis. This difference is considered from two points of view. The first is that of the equations governing the interaction process, particularly the banking mechanism that converts curvature vorticity to lateral shear vorticity and vice versa. The second is that of the dynamics of the geostrophic potential vorticity. It is concluded that, because of the imposed geostrophic constraint, the mean model does not retain the interaction process. DOI: 10.1111/j.2153-3490.1975.tb01714.x