cssi/SciSciGPT-SciSciNet huggingface dataset:
A parametric study of the finite element eigenfunction method for the scattering of SH-waves

Abstract The performance of a coupled Finite Element—Analytic method in solving elastic wave scattering in infinite spaces is studied for plane SH-waves. The influence of several parameters on the accuracy of the results is investigated. These parameters are the number of terms in the series solution, the number of compatibility points across an imaginary circular interface (i.e. the points for which the continuity of both stresses and displacements are enforced), and the ratio of element dimension to wavelength in the direction of propagation. It was found that the method converges rapidly with the number of terms. Furthermore, both element dimension to wavelength ratio and the number of compatibility points significantly influence the accuracy of the approximate solution.
In-Plane Transport and Enhanced Thermoelectric Performance in Thin Films of the Topological Insulators Bi 2 Te 3 and Bi 2 Se 3

Several small-band-gap semiconductors are now known to protect metallic surface states as a consequence of the topology of the bulk electron wave functions. The known ``topological insulators'' with this behavior include the important thermoelectric materials ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ and ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$, whose surfaces are observed in photoemission experiments to have an unusual electronic structure with a single Dirac cone. We study in-plane (i.e., horizontal) transport in thin films made of these materials. The surface states from top and bottom surfaces hybridize, and conventional diffusive transport predicts that the tunable hybridization-induced band gap leads to increased thermoelectric performance at low temperatures. Beyond simple diffusive transport, the conductivity shows a crossover from the spin-orbit-induced antilocalization at a single surface to ordinary localization.
Gonotrophic Age Structure of Host-Seeking Leptoconops carteri (Diptera: Ceratopogonidae) Populations in North-Central California

The gonotrophic age structure of two vertebrate-host-seeking Leptoconops carteri Hoffman (Diptera: Ceratopogonidae) populations from north-central California was determined by examination of ovarian activity. In specimens from the Coast Range ( n = 200), follicle development was arrested at the normal resting stage and weekly parity rates ranged from 8 to 52%. In contrast, weekly parity rates in L. carteri from the Sacramento Valley ( n = 275) averaged 96 to 100% and follicle development advanced beyond the resting stage. These conditions represent significant differences in gonotrophic age structure, and are judged to reflect anautogenous and autogenous reproductive activity, respectively. Follicle development in advance of the resting stage and parity rates <90% also characterized ovarian activity in L. carteri from each of four additional sites in the Sacramento Valley ( n = 150); this shows that autogeny, though previously unreported, is widespread in L. carteri from the region. Advanced follicle development also occurred in non-blood-fed parous Sacramento Valley females, a condition unique among hematophagous Nematocera. Vertebrate host seeking by both nulliparous and parous foothill population L. carteri establishes that anautogenous females survive in nature to seek a second blood meal.
Using Bytecode Instrumentation to Secure Information Flow in Multithreaded Java Applications

Information leakage is considered one of the vulnerabilities that may exist in careless development of software applications or unreliable and untrusted COTS binaries. Providing security at the level of programming development is important because leaking sensitive information such as credit card number, cookies, passwords or SSN does not require a lot of bandwidth to get through. In this paper, we propose a Secure Information Flow for Multithreaded Java (SIF-MJ) model, to enforce security and enhance assurance in all information flows throughout the execution time of the application without violating any rules or properties of multithreaded application. SIF-MJ does not require modification on the underlying Java Virtual Machine (JVM), therefore our proposed model is applicable to the currently existing JVMs.
Analysis of the error associated with grid representation of point sources

The steady-state, three-dimensional transport equation for inert pollutant dispersion in the atmosphere is solved analytically to obtain expressions for pollutant concentrations from both a point source and a rectangular area source. The results of this analysis have application to numerical grid models in which the smallest resolvable source is the size of a single grid. The concentrations at ground level along the plume centerline from the two types of sources are in close agreement with each other at distances greater than 10 km downwind when the horizontal dimension of the rectangular source is not less than 100 m. The dimension of the source in the vertical direction is held constant at 50 m. Similar results are obtained for concentrations along the plume centerline at the effective stack height. When the size of the source in the crosswind direction is increased to 1 km, good agreement between the two concentrations is obtained for downwind distances over 60 km for the ground level case and over 140 km for the concentration at stack height level. For the horizontal dimension equal to 10 km, good agreement between the two cases is only obtained at extremely large downwind distances at both the stack height and ground levels.
Macula densa nitric oxide synthase: Expression, regulation, and function

Macula densa nitric oxide synthase: Expression, regulation, and function. The type 1 brain nitric oxide synthase (bNOS) isoform occurs in macula densa (MD) cells where it functions to vasodilate the afferent arteriole and blunt expression of tubuloglomerular feedback (TGF). Dietary salt restriction enhances bNOS expression, yet microperfusion studies with NOS inhibitors imply that it is functionally inactive. We thus assessed the hypothesis that reduced l-arginine (L-Arg) availability during low salt (LS) intake limits MD NO generation. Maximal TGF responses were recorded during Henle's loop perfusion with artificial tubular fluid (ATF). Microperfusion of L-Arg into the MD of LS, but not normal or high-salt (HS) rats blunted maximal TGF responses (8.0 ± 0.4 to 6.0 ± 0.5mm Hg; N = 23; P + transport, because it was blocked by coperfusion with the competitors l-lysine or l-homoarginine. Absorption of [ 3 H]-L-Arg from the perfused loop, via an L-Arg— or l-homoarginine—inhibitable process, was enhanced during HS. Salt restriction thus diminishes TGF attenuation by NO in the MD despite enhanced bNOS expression because of limited delivery and/or uptake of L-Arg via system y + . This defines a novel mechanism of renal microcirculatory adaptation to salt restriction via L-Arg—dependent changes in TGF.
Non-destructive Inspection of Composites Using Step Heating Thermography

The article explores the use of step heating thermography for defect identification in glass fiber reinforced composites. Step heating methods have potential for increasing the maximum detectable defect depth as compared with pulse heating methods. Inspection of thick fiberglass composites containing flat-bottom holes and resistive embedded defects using step heating thermography is investigated using 1-D analytical models, axisymmetric finite element modes, and experimental methods. 1-D heat transfer models of embedded defects under step heating are developed based on results from previous research of pulse heating thermography. Finite element models are used to explore the range of validity of defect identification techniques based on correlation with 1-D analytical methods, and it is found that accurate results are obtained for a defect radius to thickness ratio greater than two. Experimental results demonstrate the validity of the 1-D models for high defect resistance cases. For low resistance defects...
Development of Resistance in Pseudomonas aeruginosa to Imipenem, Norfloxacin, and Ciprofloxacin During Therapy: Proof Provided by Typing with a DNA Probe

Differentiating reinfection from the acquisition of resistance in strains of Pseudomonas aeruginosa after antimicrobial therapy is difficult because currently used epidemiological markers are not stable genetic markers. We previously established that a 741-base pair Pstl-Nrul restriction fragment upstream from the Exotoxin A structural gene is a sensitive, specific, and stable epidemiological marker for P. aeruginosa.. Therefore, we used this fragment as a probe in Southern hybridization to compare pre- and post-therapy isolates of P. aeruginosa. The susceptible and resistant pairs were recovered from multiple sources (including sputum, blood, and urine) from patients treated with various doses of imipenem (n = 15), norfloxacin (n = 6), and ciprofloxacin (n = 4). Southern blot analysis showed identity between the pre- and post-therapy isolates in 23 of the 25 pairs. In the majority of pairs studied, failure to eradicate P. aeruginosa after therapy with imipenem, norfloxacin, and ciprofloxacin was due to the development of resistance rather than to reinfection.
Studies of thermal cyclizations of polyamic acids and tertiary amine salts

Thermal conversion rates of the polyamic acid derived from pyromellitic dianhydride and 4,4′-diaminodiphenyl ether are presented. Formation of the imide ring proceeds by fast and slow first-order processes. Tertiary amines give ring closures faster by a factor of 10 than the free acid. The enhancement is an activation entropy rather than an activation energy effect.
The environment and economics the impact of restricting the SO2 allowance market

Abstract This paper analyzes the effects of several types of regulatory policy on the operation of the SO2 allowance trading system established in the UC Clean Air Act Amendments of 1990 (CAAA). Theoretically, such a system can achieve environmental goals at least cost. However, regional environmental and employment concerns have suggested regulations in some states that will restrict full market operation, thereby negating many of the efficiency gains that market based regulation is designed to capture. This paper determines the costs of these regulatory interventions. These costs can be compared with employment and environmental impacts to assist policy makers in their regulatory decisions.
Desire for change in one's partner as a predictor of the demand/withdraw pattern of marital communication

Even though the demand/withdraw pattern of marital communication has been implicated as a contributor to marital dissatisfaction and divorce, relatively little research has examined why couples engage in demand/withdraw. Why would individuals engage in this seemingly negative communication pattern? To investigate this issue, a study of married couples was conducted in which the association between spouses’ desire for change in their partner and couples’ demand/withdraw communication was examined. The results indicated that individuals’ desire for change in their partner was positively related to both husband demand/wife withdraw communication and wife demand/husband withdraw communication. This suggested that spouses’ desire for change was associated with them enacting both demanding and withdrawing communication. The link between desire for change and demand/withdraw seemed particularly strong for topics that were salient to the participants. The results imply that no current model of demand/withdraw suf...
Coherent 40Gb/s OFDMA-PON for long-reach (100 + km) high-split ratio (>1:64) optical access/metro networks

We experimentally demonstrate the first coherent 40Gb/s OFDMA-PON over 100km and 130km straight SSMF with 1:128 and 1:64 passive splits, respectively. By satisfying heterogeneous reach/split requirements, the approach addresses key aspects of optical access/metro convergence.
Control of cell fate in a vertebrate neurogenic lineage

The decision of an ectodermal cell to become a neuroepithelial cell initiates the building of a nervous system. The associated choice of which of the many different neuronal lineage pathways to follow begins the process of generating the vast numbers of different neuronal phenotypes that make up these exceptionally heterogeneous systems. Cell ablations and mutations in grasshoppers, flies, and worms have demonstrated a key role for cellular interactions in these events, particularly for neural induction as well as for a process of lateral inhibition-cells preventing the realization of their neighbors' potential for neuronal differentiation. Considerable excitement attends recent progress in the genetic dissection of cellular interactions underlying neuronal differentiation in the Drosophila retina. The importance of intercellular conversations comes as no surprise to vertebrate neuroembryologists, of course, for the role of target tissues in controlling neuronal survival, growth, and differentiation has been widely appreciated for a great many years. Indeed, the molecular basis for one such interaction has been known since the mid fifties-early sixties when Levi-Montalcini and her colleagues discovered the key role played by nerve growth factor (NGF).
Two-way packing model for ribonuclease T1 fluorescence

The fluorescence intensity decay of ribonuclease T1 is biexponential at neutral pH. The lifetimes in nsec and preexponential factors of the exponential components are 3.9 (81%) and 1.7 (19%). The mutations A22L, G23A, L26A, V67G, and V67D, which all neighbor tryptophan-59, have a fairly small effect on this biexponential decay. The lifetime of the long lived component varies from 3.7 to 4.2 nsec and the preexponential varies from 75% to 92%. The emission maximum varies from 319 to 328 nm and the acrylamide quenching rate constant varies from 2.0 to 4.0 x 108 M1s1 for these mutations. Minimum perturbation mapping simulations of the tryptophan-59 side chain in wild type ribonuclease T1 show that the (chi) 2 side chain dihedral angle may adopt either a perpendicular or an antiperpendicular conformation. These computational and spectroscopic results lead us to propose a two- way packing model for tryptophan-59. This model predicts the relative free energies of the perpendicular and antiperpendicular conformations and acrylamide interaction site to indole ring distances for the wild type and mutant ribonucleases.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Model for Comparing Performance of Various Transit Maintenance Repair Policies

This paper presents a simulation model suitable for comparing a bus maintenance system's performance under various repair policies. The scope of the model is restricted to measuring only the performance of a central, heavy maintenance facility, typically found at transit systems with multiple garages. Different activities within a transit maintenance facility are simulated in this effort and a superior repair policy is determined. The numbers of active and spare buses, failure distributions of bus components, and available repair resources are included as parameters in this model because they are directly related to the repair process. The main model consists of three sub‐models: (1) Service sub‐model; (2) repair sub‐model; and (3) status sub‐model. This paper includes a detailed description of each model along with its inputs and outputs. The model is tested with real world data. First‐come‐first‐served repair rule bounded by a waiting time limit is found to be most effective in improving system performa...
Utilization of solid nanomaterials for drug delivery

Background: Solid nanostructures are versatile platforms for constructing hybrid drug delivery systems that have tremendous potential for improving disease prevention and treatment. The rationale and application of solid nanostructures in the context of drug delivery are explored in this article. Objective: The purpose of this paper is to provide a concise review of the major attributes of solid nanostructures as they relate to drug delivery and to describe the outstanding issues that need to be addressed in order to develop these materials into clinically useful reagents. Methods: The scope of this opinion has been restricted to solid nanostructures, where solid nanostructures are defined as those that are not biodegradable. The opinion has been further limited to the three primary types of nanostructures: nanoparticles, nanowires and nanotubes. Results/conclusion: There is a need for cross-disciplinary training and standardized protocols for developing and evaluating the efficacy of solid nanomaterials.
Increased choroidal thickness in patients with Sturge-Weber syndrome.

Importance With the recent development of enhanced depth imaging spectral-domain optical coherence tomography (SD-OCT), it is now possible to measure choroidal thickness in patients with Sturge-Weber syndrome and detect abnormalities that are not visible as part of the fundus examination. Observations We were successful in imaging at least 1 eye in 12 individuals with Sturge-Weber syndrome using enhanced depth imaging SD-OCT. Eyes were defined as affected if they manifested at least one of the following: darkened choroid, glaucomatous optic nerve damage, or conjunctival hyperemia. None of the participants had a clinically visible choroidal hemangioma. The affected eyes had over twice the choroidal thickness of the unaffected eyes (mean [SD], 697 [337] μm vs 331 [94] μm; P = .004, determined by use of an unpaired t test). For the 6 unilaterally affected participants who had both eyes imaged, the choroidal thickness was greater in the affected eyes than in the unaffected eyes of 5 participants (mean [SD], 672 [311] μm vs 329 [88] μm; P = .01, determined by use of a paired t test). Conclusions and Relevance The advent of enhanced depth imaging SD-OCT has allowed us to quantify choroidal thickness in the posterior pole, even in eyes with a markedly thickened choroid, such as those found in individuals with Sturge-Weber syndrome. Spectral-domain OCT has a much higher resolution (5-10 μm) than B-scan ultrasonography (150 μm) and can be used to distinguish between the retina and the choroid. Furthermore, enhanced depth imaging SD-OCT can detect choroidal thickness in eyes without clinically apparent choroidal abnormalities.
On the existence of common quadratic Lyapunov functions for second‐order linear time‐invariant discrete‐time systems

Necessary and sufficient conditions for the existence of a common quadratic Lyapunov function (CQLF) are given for two second-order linear time-invariant discrete-time systems. These conditions are later extended to an arbitrary number of systems. The conditions are readily verifiable both analytically and graphically. The paper also provides a constructive procedure for computing a CQLF when it exists. Copyright © 2002 John Wiley & Sons, Ltd.
Rigidity, global rigidity, and graph decomposition

The recent combinatorial characterization of generic global rigidity in the plane by Jackson and Jordan (2005) [10] recalls the vital relationship between connectivity and rigidity that was first pointed out by Lovasz and Yemini (1982) [13]. The Lovasz-Yemini result states that every 6-connected graph is generically rigid in the plane, while the Jackson-Jordan result states that a graph is generically globally rigid in the plane if and only if it is 3-connected and edge-2-rigid. We examine the interplay between the connectivity properties of the connectivity matroid and the rigidity matroid of a graph and derive a number of structure theorems in this setting, some well known, some new. As a by-product we show that the class of generic rigidity matroids is not closed under 2-sum decomposition. Finally we define the configuration index of the graph and show how the structure theorems can be used to compute it.
Two-component initiator systems for the ring-opening polymerization of oligomeric cyclic bisphenol-A carbonates: The in situ cleavage of disulfides by triarlyphosphines

A two-component initiator system based on the in situ cleavage of phenyl disulfide by a triarylphosphine has been developed for the ring-opening polymerization of cyclic bisphenol-A (BPA) carbonate oligomers. This development has potential use in composite applications such that the prepolymer can suitably wet the composite material before being converted to high-molecular-weight polymer. The initiator precursors (phenyl disulfide and triphenylphosphine) do not independently initiate significant ring-opening polymerization of the oligomeric cyclic BPA carbonate mixture. A mixture of cyclic BPA carbonate oligomers and one of the initiator components (phenyl disulfide), combined and heated at 300°C with a mixture of the cyclics and the other initiator component (triphenylphosphine), does produce a high-molecular-weight polymer (Mw = ∼ 70,000). The polymerization-initiating species is thought to be thiophenyltriphenylphosphonium thiophenoxide. The effects of concentration of the initiator components, reaction temperature, time, and so forth on polymerization were studied; in general, the degree of polymerization ranged from about 65 to 75%. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 2251–2255, 1997
Functional Analysis of the C-terminal Extension of Telomerase Reverse Transcriptase: A PUTATIVE “THUMB” DOMAIN

Telomerase is an RNA-protein complex responsible for the extension of one strand of telomere terminal repeats. The catalytic protein subunit of telomerase, known generically as telomerase reverse transcriptase (TERT), exhibits significant homology to reverse transcriptases (RTs) encoded by retroviruses and retroelements. The mechanisms of telomerase may therefore be similar to those of the conventional reverse transcriptases. In this report, we explore potential similarity between these two classes of proteins in a region with no evident sequence similarity. Previous analysis has implicated a C-terminal domain of retroviral RTs (known as the "thumb" domain) in template-primer binding and in processivity control. The equivalent region of TERTs, although similar to one another, does not exhibit significant sequence homology to retroviral RTs. However, we found that removal of this region of yeast TERT similarly resulted in a decrease in the stability of telomerase-DNA complex and in the processivity of telomerase-mediated nucleotide addition. Moreover, the C-terminal domain of TERT exhibits a nucleic acid binding activity when recombinantly expressed and purified. Finally, amino acid substitutions of conserved residues in this region of TERT were found to impair telomerase activity and processivity. We suggest that mechanistic similarity between telomerase and retroviral RTs may extend beyond the regions with apparent sequence similarity.
Attenuation of soil radiation by vegetation: a physical approach

A model is developed to relate the attenuation through a vegetation canopy, to the geometric and dielectric parameters of the canopy constituents. The model is designed to operate over a wide frequency band in the microwave region and include both deciduous and coniferous trees. The vegetation canopy is represented by a discrete random layer of cylinders and disks having the same geometric and dielectric properties as the vegetation canopy constituents. The Foldy-Twersky Integral Equation is used to relate the attenuation to the scattering amplitude of the vegetation constituent evaluated in the forward direction. Numerical results are presented to show how the level and frequency dependance of the attenuation depend on type of vegetation constituent and its orientation.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Chronic hydrocephalus-induced hypoxia: increased expression of VEGFR-2+ and blood vessel density in hippocampus.

Abstract Chronic hydrocephalus (CH) is a neurological disease characterized by increased cerebrospinal fluid volume and pressure that is often associated with impaired cognitive function. By and large, CH is a complex and heterogeneous cerebrospinal fluid (CSF) disorder where the exact site of brain insult is uncertain. Several mechanisms including neural compression, fiber stretch, and local or global hypoxia have been implicated in the underlying pathophysiology of CH. Specifically, the hippocampus, which plays a significant role in memory processing and is in direct contact with expanding CSF ventricles, may be involved. Using our model of chronic hydrocephalus, we quantified the density of vascular endothelial growth factor receptor 2 (VEGFR-2 + ) neurons, glial, endothelial cells, and blood vessels in hippocampal regions CA1, CA2-3, dentate gyrus and hilus using immunohistochemical and stereological methods. Density and %VEGFR-2 + cell populations were estimated for CH animals (2–3 weeks vs. 12–16 weeks) and surgical controls (SC). Overall, we found approximately six- to eightfold increase in the cellular density of VEGFR-2 + and more than double blood vessel density (BVd) in the hippocampus of CH compared with SC. There were no significant regional differences in VEGFR-2 + cellular and BVd expression in the CH group. VEGFR-2 + and BVds were significantly related to changes in CSF volume ( P ≤0.05), and not intracranial pressure (ICP). The %VEGFR-2 + was significantly greater in CH than SC ( P ≤0.05), and was significantly correlated with BVd ( P ≤0.05). These results showed that CH elicited a profound increase in VEGFR-2 + in hippocampus that corresponded to increased BVd. It was unclear whether increased VEGFR-2 + and blood vessel expression was related to focal compression alone or in combination with global ischemia/hypoxia conditions as previously described. These findings suggest that VEGFR-2 may play an adaptive role in angiogenesis after CH-induced hypoxia. Modulation of vascular endothelial growth factor/VEGFR-2 + may be important in developing treatments for hypoxic conditions including hydrocephalus and other forms of cerebral ischemia.
The cytochrome b6f complex

Abstract The cytochrome b 6 f complex in oxygenic photosynthetic membranes is believed to have many structure-function analogies to the cytochrome bc 1 complex found in the mitochondrial respiratory chain and in chromatophore membranes of purple photosynthetic bacteria. Three polypeptides in the complex, cytochrome f , cytochrome b 6 and the Rieske iron-sulfur protein contain redox prosthetic groups. Cytochromes f and b 6 are anchored to the membrane by one transmembrane helix and four transmembrane helices respectively. Recent studies on the Rieske high-potential iron-sulfur protein suggest that it may be an extrinsic membrane protein. As in mitochondria, the complex that is active in vitro is predominantly dimeric and it has not yet been possible to obtain a monomeric complex that has significant activity. The crystal structure of the major (252 residues, 87% of the protein) lumenal domain of cytochrome f has been solved to high (2.3 A) resolution. The elongate predominantly β-strand structure, reminiscent of the motif of animal cell surface proteins, and the amino-terminal α-amino group acting as an axial heme ligand are unique features of the structure. This ligation provided an unexpected insight into the mechanism of translocation of the protein into the membrane. The structure makes specific predictions about the location of the positively charged docking site for the electron acceptor, plastocyanin.
Relationship of skinfolds and muscle size to growth of children. I. Costa Rica

The relationships between triceps skinfolds and stature and between upper arm muscle size and stature were studied on 874 pairs matched for age derived from a cross-sectional sample of 2,445 Costa Rican rural subjects, aged 0 to 20 years. The results indicate that fatter children for their age, on the average, are not taller than their leaner counterparts. On the other hand, more muscular children, on the average, are taller than their less muscular counterparts of the same age.
Numerical implementation of an adaptive fast-field program for sound propagation in layered media using the chirp z transform

Using the chirp z transform, a numerically efficient adaptive integration algorithm for fast-field programs has been developed. The fast-field program (FFP) is a numerically efficient algorithm for computation of the sound pressure due to a time harmonic point source above a general boundary in a layered medium. The new algorithm allows the user to specify the precise location of the range sample points, or “detectors,” independent of the horizontal wave-number sampling grid. This feature makes the algorithm particularly attractive for use in applications where sampling on a predetermined spatial is required. An example of such an application is the computation of the acoustic frequency response as a function of range. In this case the complex sound pressure must be computed at many frequencies while maintaining a constant range sampling interval. In addition, the algorithm can be used to recompute the sound pressure field with different range resolutions without recomputing the horizontal wave-number spe...
Journey on greener pathways: from the use of alternate energy inputs and benign reaction media to sustainable applications of nano-catalysts in synthesis and environmental remediation

Sustainable synthetic processes developed during the past two decades involving the use of alternate energy inputs and greener reaction media are summarized. These processes include examples of coupling reactions, the synthesis of heterocyclic compounds, and a variety of reactions catalyzed by basic water or recyclable and reusable magnetic nano-catalysts in aqueous media or polyethylene glycol (PEG) using microwave (MW) irradiation or mechanochemical mixing. Micropine-structured catalysts, magnetic nanoferrites and their synthetic modifications with ligands, and decoration with other nano-metals serve as sustainable nano-catalysts in eco-friendly media. Titanium dioxide (TiO2) can be doped with metal (Ag) and nonmetal atoms such as sulfur (S), nitrogen (N) and carbon (C) to enhance its activity in visible light. These strategic approaches attempt to fulfill most of the Green Chemistry Principles in a comprehensive manner and aim to generate sustainable functional chemicals that may find large-scale use with significant waste minimization.
Neurobehavioral evaluations of mixtures of trichloroethylene, heptachlor, and di(2-ethylhexyl)phthlate in a full-factorial design

Abstract One approach to the toxicological evaluation of chemical mixtures is to construct full dose–response curves for each compound in the presence of a range of doses of each of the other compounds, i.e., a factorial design. This study was undertaken as part of an interdisciplinary project to evaluate a mixture of three environmental pollutants. A full-factorial design was undertaken to determine the neurobehavioral consequences of short-term repeated exposure to five dose levels each of three chemicals, in order to characterize potential two- and three-way interactions. Adult female F344 rats received (p.o.) for 10 days either one of five doses of trichloroethylene, di(2-ethylhexyl)phthalate, or heptachlor, or else one of all possible chemical combinations. Neurobehavioral evaluations were conducted using motor activity and an abbreviated functional observational battery. Response-surface analysis was applied to each of the endpoints. Hypotheses were tested based on the estimated model parameters; of primary interest was the overall test for interaction among the three chemicals. In addition, an abbreviated design was created by fitting only a subset of the data to the model. In general, significant overall interactions that deviated from response additivity were detected for most endpoints (11 of 14). All of the interactions on the neurobehavioral endpoints showed either antagonism, or else an interaction that could not be fully characterized. Often the results of the abbreviated dataset analysis were not the same as for the full-factorial design. This study was extremely intensive, in terms of the number of rats and time required for conduct of the study as well as the data analysis. These results underscore the need for more economical approaches to evaluate the toxic effects of mixtures of chemicals.
Adventures of a Rydberg electron in an anisotropic world

The study of subtle interactions in atomic and molecular systems has stirred scientific curiosity since the dawn of quantum mechanics. Even today, research into perturbative long-range interactions continues to push into new territory, driven largely by the experimental capabilities of Rydberg state spectroscopy to detect effects of extremely weak interactions. While static long-range multipole interactions have been studied for years, the presence of dynamic terms that involve both position and momentum operators has been demonstrated only surprisingly recently. In this paper we document the existence of an effective vector interaction term in the long-range potential experienced by a moving charged particle in the presence of an anisotropic ionic core. In contrast to ordinary static quadrupole or dipole interaction terms, the existence of this vector interaction hinges on the motion of the distant charge as it roams beyond the confines of the core.
Religion and prejudice: Lessons not learned from the past.

Altemeyer and Hunsberger (1992) analyzed fundamentalism and prejudice. Unfortunately, their article failed to provide data on several issues that past literature has established as crucial. The use of denominational affiliation, the failure to include intrinsic and extrinsic scales, and the failure to recognize the interaction of different value positions among Christian groups with other religious variables limits the interpretability of the results and thus the major conclusions that the authors attempt to draw.
The structure of the central region in the synaptonemal complexes of hamster and cricket spermatocytes.

The fine structure of bivalents from golden hamster and house cricket spermatocytes has been studied with a whole mount surface-spreading method combined with negative staining. The elements of the synaptonemal complex show detail of structure which is absent in other preparative procedures. The transverse filaments found in the central region of the synaptonemal complex from both species are straight and have a similar width, 1 6–1 8 nm These filaments occur mainly in bundles The central element differs in architecture in the two species In hamster bivalents it is formed of longitudinal stretches of filaments 1.6–1 8 nm wide and a small amount of an amorphous material similar to that of the lateral elements In the cricket, the central element contains transverse fibrils which are continuous with the transverse filaments of the central region, and an amorphous material lying mainly along the sides of the central element All of the components of the central region of the synaptonemal complex are resistant to pancreatic DNase. The overlapping ends of the transverse filaments, together with additional protein material, make up the central element The widespread occurrence and close morphological and histochemical interspecies similarities of the transverse filaments indicate that they serve an essential role, probably one concerned with holding synapsed bivalents together via the lateral elements. Restrictions placed by the observations reported here on current models of the synaptonemal complex are discussed.
Investigations of aerosol impacts on hurricanes: virtual seeding flights

Abstract. This paper examines the feasibility of mitigating the intensity of hurricanes by enhancing the CCN concentrations in the outer rainband region. Increasing CCN concentrations would cause a reduced collision and coalescence, resulting in more supercooled liquid water to be transported aloft which then freezes and enhances convection via enhanced latent heat of freezing. The intensified convection would condense more water ultimately enhancing precipitation in the outer rainbands. Enhanced evaporative cooling from the increased precipitation in the outer rainbands would produce stronger and more widespread areal cold pools which block the flow of energy into the storm core, ultimately inhibiting the intensification of the tropical cyclone. We designed a series of multi-grid for which the time of the "virtual flights" as well as the aerosol release rates are varied. A code that simulates the flight of a plane is used to increase the CCN concentrations as an aircraft flies. Results show a significant sensitivity to both the seeding time and the aerosol release rates and support the aforementioned hypothesis.
Anthracene as a Non-hygroscopic Diluting Agent for Mössbauer Spectroscopy of Silicate Samples in Moisture-Uptake Studies

Anthracene gained no mass when held in a humid chamber and showed no gamma absorption and so appears to be suitable as a replacement for sugars for dilution of moisture-sensitive 57Fe-Mossbauer spectroscopy samples. Applied to studies of moisture effects on a circumstellar silicate dust simulant, anthracene permitted preparation of sample series for experimental determination of optimal 57Fe-Mossbauer areal density.
THE CRYSTAL STRUCTURES OF d-PINITOL AND l-QUEBRACHITOL BY LOW-TEMPERATURE X-RAY DIFFRACTION

The crystal and molecular structures of d-pinitol and l-quebrachitol were determined from low temperature x-ray diffraction data. Pinitol crystallizes in an orthorhombic system, P212121 (Z=4), with unit cell dimensions of a=6.8345(8) A, b=9.3233(10) A, and c=12.8911(14) A. Quebrachitol crystallizes in a monoclinic system, P21 (Z=2), with unit cell dimensions of a=6.6289(4) A, b=7.1895(4) A, c=8.6843(5) A, and β=90.5690(10)°. No unusual bond lengths or valence angles are present within either structure. Both rings are in chair conformations, with the majority of the pendent groups in equatorial orientations. As found for many compounds with multiple hydroxyl groups, the structures have extensive networks of hydrogen bonds. Both structures have infinite chain sequences of hydrogen bonds incorporating the O-1 and O-4 hydroxyl groups and finite chain sequences incorporating the other hydroxyl groups.
A homogeneous isoenzyme of human liver acid phosphatase.

Abstract An isoenzyme of human liver acid phosphatase (orthophosphoric monoester phosphohydrolase (acid optimum), EC 3.1.3.2) has been purified 4560-fold to homogeneity. The purification procedure includes ammonium sulfate fractionation, acid treatment, ion exchange chromatography on O-(carboxymethyl)-cellulose and DEAE-cellulose, Sephacryl S-200 chromatography, and affinity chromatography on Concanavalin A-Sepharose 4B. The homogeneous enzyme is a glycoprotein having 4% carbohydrate by weight in the form of mannose and glucosamine. In polyacrylamide gel electrophoresis under varied conditions of pH and cross-linking, the purified enzyme displays a single protein band coincident with activity. The native enzyme has a molecular weight of 93,000 as determined by gel elution chromatography and consists of two equivalent polypeptide chains. The subunit weight is 50,000–52,000 by sodium dodecyl sulfate gel electrophoresis. l -(+)-Tartrate is a strong competitive inhibitor of the enzyme; Ki is 4.3 × 10−7 m at pH 4.8 in 50 m m sodium acetate/100 m m sodium chloride. Ki values for a number of other inhibitors are given. Although it catalyzes the hydrolysis of a variety of phosphomonoesters, this isoenzyme of human liver acid phosphatase does not hydrolyze adenosine 5′-diphosphate, adenosine 5′-triphosphate, pyrophosphate, or choline phosphate at a detectable rate. The values of V differ with different alcohol or phenol leaving groups. The pH dependence of Km and V values for the hydrolysis of p-nitrophenyl phosphate have been determined together with the pH dependence of Ki for l -(+)-tartrate. The pH dependence of both Km and V indicate the effect of substrate ionization (pK ~ 5.2) and the involvement of a group in the EScomplex having a pKa value of approximately 6–7 which is ascribed either to a phosphoryl-enzyme intermediate or to the ionization of substrate in the ES-complex. An irreversible modification of the enzyme and a rapid loss of enzymic activity occurs upon treatment of the enzyme with Woodward's reagent K. The enzyme is protected against inactivation by the presence of competitive inhibitors. These and other data suggest that at least one carboxylic acid group plays an important role in catalysis.
PACAP and Its Receptors Exert Pleiotropic Effects in The Nervous System by Activating Multiple Signaling Pathways

Pituitary adenylate cyclase-activating polypeptide (PACAP) was originally isolated from the ovine brain in 1989 as a novel hypothalamic hormone that potently activates adenylate cyclase to produce cyclic AMP in pituitary cells. This neuropeptide belongs to the secretin/glucagon/vasoactive intestinal peptide (VIP) superfamily, and exists in two amidated forms as PACAP38 (38-amino acid residues) and PACAP27 derived from the same precursor. The primary structure of PACAP has been remarkably conserved throughout evolution among tunicata, ichthyopsida, amphibia and mammalia, and a PACAP-like neuropeptide has also been determined in Drosophila. Both PACAP and its receptors are mainly distributed in the nervous and endocrine systems showing pleiotropic functions with high potency. There are three types of receptors with high PACAP-binding affinity and with different tissue-distribution patterns. All of them belong to G-protein-coupled receptor superfamily with seven transmembrane domains. PAC(1) is the PACAP-specific receptor and exists in at least eight splice variants which couple to different intracellular signal transduction pathways. VPAC(1) and VPAC(2) are the common receptors for both PACAP and VIP, which are coupled to adenylate cyclase. This review article presents and discusses an update on PACAP research and its pleiotropic physiological functions based on multiple receptor-mediated signaling mechanisms in both the central and peripheral nervous system, including the regulation of hypothalamic neurosecretion, homeostatic control of circadian clock and behavioral actions, involvement in learning and memory processes, neuroprotective effects such as anti-apoptosis and response to injury and inflammation, and neural ontogenetic functions on proliferation/differentiation processes from early stages.
Presenilin expression in the ocular lens

PURPOSE. Mutations in the presenilin (PS) proteins account for the majority of early onset Alzheimer's disease (AD) cases, apparently by influencing the cleavage of the Alzheimer's disease protein (sAPP) to form s-amyloid (As), the major component of plaques in the brains of AD patients. We reported previously that AD proteins are expressed in mammalian lenses, and that sAPP and As increased in the epithelium and outer cortex of lenses subjected to oxidative stress. This increase paralleled the increase in AP1 DNA binding activity, which has been shown to accompany proliferative oxidative stress responses. Both cataract and AD have been closely linked with oxidative stress; further, both AD and cataract occur in a majority of Down Syndrome individuals. Here we investigate the expression and post-translational processing of PS proteins in the ocular lens. METHODS. In situ hybridization, immuohistochemical detection and immunoblot assays were used to localize mRNA and proteins expression products and determ...
Smart tribological coatings with wear sensing capability

Abstract Tribological coatings were developed to allow automatic reporting of remaining wear life while in use. Monitoring of coating health was achieved by embedding sensor layers, known to produce distinctive luminescence spectra when exposed to laser illumination, throughout the thickness of a solid lubricant coating. For the current work, erbium- and samarium-doped yttria stabilized zirconia (YSZ) layers were used as sensor materials. One sensor layer was placed approximately midway through a molybdenum disulfide coating and another was located at the coating/substrate interface. Placement of the luminescent coatings in these positions allowed detection of wear depth and provided a warning of impending coating failure during testing. This smart coating concept is generally applicable to tribological coatings and can easily be implemented to safely increase reliance upon protective materials subject to wear and other damage mechanisms. The soft MoS2 coatings with the imbedded ceramic sensor layers also demonstrated long wear lives (≈200,000 cycles) in humid air compared to monolithic MoS2 coatings (
Vertex-minimal simplicial immersions of the Klein bottle in three space

Although the Klein bottle cannot be embedded inR 3, it can be immersed there, and in more than one way. Smooth examples of these immersions have been studied extensively, but little is known about their simplicial versions. The vertices of a triangulation play a crucial role in understanding immersions, so it is reasonable to ask: How few vertices are required to immerse the Klein bottle inR 3? Several examples that use only nine vertices are given in Section 3, and since any triangulation of the Klein bottle must have at least eight vertices, the question becomes: Can the Klein bottle be immersed inR 3 using only eight vertices? In this paper, we show that, in fact, eight isnot enough, nine are required. The proof consists of three parts: first exhibiting examples of 9-vertex immersions; second determining all possible 8-vertex triangulations ofK 2; and third showing that none of these can be immersed inR 3.
Economic Wellbeing and Where We Live: Accounting for Geographical Cost-of-Living Differences in the US

Regional cost-of-living differences affect the quality of life that individuals and families experience in different metropolitan areas. Yet, lack of metropolitan cost-of-living indexes has left an...
Caveolin regulation of neuronal intracellular signaling

Caveolin proteins physically interact with and compartmentalize membrane-localized signaling proteins to facilitate high-fidelity intracellular signaling. Though primarily studied outside the nervous system, recent investigations have revealed that caveolin proteins are key modulators of a variety of neuronal intracellular signaling pathways. Through both protein aggregation and segregation, caveolin proteins can exert positive and negative influences on intracellular signaling. This review will detail recent findings regarding caveolin function in the brain.