cssi/SciSciGPT-SciSciNet huggingface dataset:
On linear differential-algebraic equations and linearizations

On the background of a careful analysis of linear DAEs, linearizations of nonlinear index-2 systems are considered. Finding appropriate function spaces and their topologies allows to apply the standard Implicit Function Theorem again. Both, solvability statements as well as the local convergence of the Newton-Kantorovich method (quasilinearization) result immediately. In particular, this applies also to fully implicit index-1 systems whose leading nullspace is allowed to vary with all its arguments.
Global delivery of education via the Internet

Describes the issues associated with global delivery of education via the Internet, as well as the academic, technical, administrative, instructional, and behavioral considerations. Also presents a course delivery prototype, which has been designed to serve as a shell for the development of full‐length courses. The paper’s position is that eventually a cyber‐academia will be progressively formed, with its own culture and institutions, which will meet the needs of those who are time or place constrained.
Predictors of biting fly harassment and its impact on habitat use by feral horses (Equus caballus) on a barrier island

Feral horses on Assateague Island, Maryland, were observed in June and August 2000 to determine what behavioral and ecological factors affect the intensity of biting fly harassment and whether habitat use by horses was influenced by biting flies. Fly counts and frequencies of comfort movements (i.e., movements designed to dislodge insects) were recorded during focal animal samples, as well as data on sex, group size, habitat type, temperature, humidity, wind speed, and behavior. Seasonal habitat use patterns were assessed using 7 years of monthly census data on the horses. The number of biting flies on the horse was affected by horse sex, habitat, temperature, and group size. The number of comfort movements a horse showed was affected by habitat, temperature, wind speed, group size, and number of horses within one body length of the focal. The number of comfort movements made by a horse was found to be highly correlated with fly numbers. Though marshes were used most throughout the year, the pattern of use of dune, scrub, and human-altered habitats reflects a pattern of biting fly avoidance and refuge-seeking by the horses.
Influence of canopy structure and direct beam solar irradiance on snowmelt rates in a mixed conifer forest

Abstract Sub-canopy snow ablation rates were measured for three years at forested research plots in the Sierra Nevada, California with a network of 24 automated snow depth sensors and monthly snow density surveys. Snow ablation rates, in mm SWE day −1 , specific to each depth sensor location were estimated as the seasonal maximum SWE divided by the number of days from peak SWE to snow disappearance. Estimates of sub-canopy direct beam solar irradiance and sky view factor ( SVF θ ) derived from hemispherical photographs were used to explain the spatial distribution of snow ablation rates. Cumulative direct beam irradiance during the observed snowmelt periods explained the most variability in snow ablation rates for the most cloud-free melt season (58% in 2008; 4 cloudy days; at 15 sensor locations snowmelt duration ranged from 39 days to 88 days and direct irradiance ranged from 96 MJ m −2 to 603 MJ m −2 ) and explained the least ablation variability for the cloudiest melt season of the study (29% in 2009; 23 cloudy days; at 12 sensor locations snowmelt duration ranged from 45 days to 79 days and direct irradiance ranged from 121 MJ m −2 to 410 MJ m −2 ). Conversely, sky view factor ( SVF θ ) explained the most variability in snow ablation rates under cloudier conditions (i.e. 87% in 2009) and the relationships were strongest when developed over the entire hemisphere (i.e. SVF 90° , which ranged from 0.17 to 0.31). Combined, the two metrics studied here (sub-canopy direct beam irradiance and SVF θ ) may be used to explain much of the observed plot-scale variability in SWE ablation at finer time scales relevant to snow and hydrological model applications.
Low power testing of losses in components for the ITER ECH transmission lines

The transmission lines (TLs) for ITER electron cyclotron heating require extremely low losses, since the 24 MW of power generated by the 170 GHz gyrotrons should be delivered to the plasma with an efficiency of 83% or more. We are developing cold-test techniques to precisely measure the losses in the TL components for ITER, before installation. Experimental results on the measurement of the loss in some TL systems with coherent and incoherent techniques are presented and compared. We report a preliminary measurement of loss in the prototype TL components for the ITER 170 GHz transmission line.
Functional reconstitution of an isolated sodium channel from bovine trachea.

Abstract An amiloride-sensitive Na + channel from bovine trachea was isolated using an affinity gel and reconstituted into a planar lipid bilayer. This channel exhibited: 1. 1. Fluctuations with long duration opening and closing times, weak voltage dependence, and a conductance of 6 pS. 2. 2. Selectivity of at least 100-fold for Na + over K + . 3. 3. Saturates at a Na + concentration of 90 mM. 4. 4. Blocked by amiloride, 50% inhibition at 0.1 μM.
New Model for Estimating the Time-Variant Seismic Performance of Corroding RC Bridge Columns

AbstractCorrosion of reinforcement is a predominant reason for reduced service lives of reinforced concrete (RC) structures exposed to aggressive environments. This deterioration process can lead to damage resulting in capacity loss or even structural failure, especially in coastal marine environments or where deicing or antiicing applications occur. Based on data from the National Bridge Inventory in 2010, the average bridge age in the country is 40 years old. Thirty percent of the bridges have exceeded 50 years, 7% have exceeded 75 years, and 25% are deemed deficient. For bridges exposed to chlorides (coastal areas or deicing or antiicing exposure), these older bridges often experience corrosion of the reinforcement. When reinforcement corrodes, the capacity of the structure is likely reduced, although little work has been reported on quantifying the reduction in performance and reliability. In seismic areas, this reduction in capacity may be magnified due to the loading demands during a seismic event. ...
The influence of retrieval processes in verbal overshadowing.

Recent studies of eyewitness memory have observed deleterious effects of producing a verbal description on later identification accuracy of a previously viewed face, an effect termedverbal overshadowing (Schooler & Engstler-Schooler, 1990). The present research investigated whether the phenomenon of verbal overshadowing may be constrained by variation in participants’ initial retrieval processes, such that verbalization of a previously viewed stimulus could produce either positive or negative influences on subsequent attempts at recollection. To assess the validity of this hypothesis, we manipulated participants’ response criterion during the verbal description task. As predicted, variation in response criterion significantly influenced not only the quality of the description generated but also accuracy on a subsequent identification task. This retrieval-based effect was found to persist despite either a postdescription delay (Experiment 1) or source-monitoring instructions at the time of the identification task (Experiment 2). We conclude that retrieval-based processes exert a powerful influence over the accuracy of verbalization and subsequent identification of a target face.
Adolescents’ Response to Parental Efforts to Influence Eating Habits: When Parental Warmth Matters

Previous findings have shown both beneficial and adverse effects of parents' attempts to influence adolescents' eating habits. The current study examined the differential effect of parents' persuasion (e.g., encouragement, giving information) and pressure tactics (e.g., guilt induction, ridicule) and the moderating influence of parental warmth on older adolescents' emotional and behavioral responses. An ethnically diverse sample of 336 older adolescents (M age = 18.6; SD = 1.1; 58.0% female) were surveyed. Adolescents who reported higher levels of pressure tactics by parents reported more negative affect and behavioral resistance. Perceived parental warmth moderated the influence of persuasion tactics, but not pressure tactics. For adolescents with low parental warmth, high levels of persuasion were associated with more negative emotional and behavioral responses; persuasion had the opposite associations for adolescents with high parental warmth. These results suggest that parental warmth plays an important role in how older adolescents respond to parents' persuasion tactics. However, when parents use more forceful pressure tactics to influence eating habits, adolescents react negatively regardless of the overall quality of the parent-adolescent relationship.
Metabolic .beta.-hydroxylation and N-oxidation of n'-nitrosonornicotine

3'-Hydroxy-N'-nitrosonornicotine (2), 4'-hydroxy-N'-nitrosonornicotine (3), N'-nitrosonornicotine 1-N-oxide (4) were synthesized and identified as metabolites in the F-344 rat of the tobacco-specific carcinogen N'-nitrosonornicotine (1). For the synthesis of 2, myosmine (5) was converted to 3'-bromomyosmine (6). Displacement by acetate and hydrolysis gave 3'-hydroxymyosmine (7), which was reduced and nitrosated to give 2. 4'-Hydroxymyosmine (13), the precursor to 3, was prepared by ammonolysis of 1,2-epoxy-4-(N-morpholino)-4-(3-pyridyl)-4-cyanobutane (10). N'-Nitrosonornicotine 1-N-oxide (4) was prepared by m-chloroperbenzoic acid oxidation of 1. When 1 was incubated with liver microsomes from Aroclor-pretreated F-344 rats, trace amounts of 2 and 3 were produced and 4 was a major metabolite. The urine from rats treated with N'-nitrosonornicotine-2'-14C contained only trace amounts of 2 and 3, whereas 4 accounted for 6.7-9.4% of the dose.
Molecular weight distribution functions and virial coefficients from sedimentation equilibrium data.

Abstract A survey of the methods in the literature for determining molecular weight distributions is undertaken. New methods and improvement of the old methods in all instances are proposed for the determination of molecular weight distributions. Special emphasis is laid on biological systems which form concentration dependent aggregates. The use of molecular weight averages to determine the upper and lower bounds of those distributions is invoked as an aid in the determination of the distribution functions. Some of the methods described can also be used to determine the virial coefficients of concentration dependent aggregating systems regardless of the number of virial coefficients involved. In addition, the methods can simultaneously determine virial coefficients and association constants. A number of methods are also described for processing the raw data in the best manner for their future use by the methods proposed herein. Statistics are stressed throughout. In every instance where we determine parameters, whether those parameters are virial coefficients or pertain to molecular weight distributions, we show how the standard errors on those parameters and the confidence intervals on them are determined by using various standard statistical techniques and tests.
Suppression of intragenic transcription requires the MOT1 and NC2 regulators of TATA-binding protein

Chromatin structure in transcribed regions poses a barrier for intragenic transcription. In a comprehensive study of the yeast chromatin remodelers and the Mot1p-NC2 regulators of TATA-binding protein (TBP), we detected synthetic genetic interactions indicative of suppression of intragenic transcription. Conditional depletion of Mot1p or NC2 in absence of the ISW1 remodeler, but not in the absence of other chromatin remodelers, activated the cryptic FLO8 promoter. Likewise, conditional depletion of Mot1p or NC2 in deletion backgrounds of the H3K36 methyltransferase Set2p or the Asf1p-Rtt106p histone H3-H4 chaperones, important factors involved in maintaining a repressive chromatin environment, resulted in increased intragenic FLO8 transcripts. Activity of the cryptic FLO8 promoter is associated with reduced H3 levels, increased TBP binding and tri-methylation of H3K4 and is independent of Spt-Ada-Gcn5-acetyltransferase function. These data reveal cooperation of negative regulation of TBP with specific chromatin regulators to inhibit intragenic transcription.
Convexity and Empirical Option Costs of Mortgage Securities

The fact that mortgage borrowers have an option to prepay has several effects. Because the borrowers hold a call option, the value of mortgage-backed securities is reduced by the value of the option. Also, the effective duration of mortgage-backed securities is reduced. Breeden focuses on the second-order effect of the negative convexity of mortgage-backed securities, which is caused by the presence of the prepayment option.
Effect of fat feeding on human intestinal apolipoprotein B mRNA levels and editing

Our purpose was to assess the effect of a fat-rich meal on intestinal apolipoprotein B (apoB) mRNA levels and editing. We obtained jejunal biopsies from eight healthy adults in the fasting state and 3 h after a meal containing 1 g/kg of fat. In the fasting state, 93% of the apoB mRNA contained the editing sequence resulting in apoB-48 production. Feeding induced no significant changes in apoB mRNA levels or editing. Our data are consistent with the concept that the significant increase in apoB-48 within triglyceride-rich lipoproteins in postprandial plasma is not due to alterations in apoB gene expression or editing.
Drag king magic: performing/becoming the other.

This chapter seeks to theorize drag king practice through the lenses of alterity, liminality, and performance theory, while attempting to complicate and reinvigorate discussions of identity raised by drag. I examine the ways in which drag king performance plumbs the concept of "the Other," and forces confrontation with a complex field of desire. Contemporary "queergirl" existence negotiates a range of desirable and desiring Others, from the polarities (i.e., butch-femme) unique to queer structures of desire, to the desire of those on the cultural margins for the power of those at the center, and vice versa. I employ anthropological theories of performance, mimesis, and liminality to establish a framework through which drag kings may be viewed as crucibles of this desire and agents of this power exchange. By performing maleness, drag kings expand and redraw the definitional boundaries of the male, interfere with the cultural power of mainstream maleness, and simultaneously transfer some of this power to themselves as queer women. At the same time, drag king existence forces a renegotiation of queergirl desire to encompass a range of masculinities. By performing/becoming the Other, drag kings engage in a practice of magic which transforms both margin and center.
Edge-preserving image compression for magnetic-resonance images using dynamic associative neural networks (DANN)-based neural networks

With the tremendous growth in imaging applications and the development of filmless radiology, the need for compression techniques that can achieve high compression ratios with user specified distortion rates becomes necessary. Boundaries and edges in the tissue structures are vital for detection of lesions and tumors, which in turn requires the preservation of edges in the image. The proposed edge preserving image compressor (EPIC) combines lossless compression of edges with neural network compression techniques based on dynamic associative neural networks (DANN), to provide high compression ratios with user specified distortion rates in an adaptive compression system well-suited to parallel implementations. Improvements to DANN-based training through the use of a variance classifier for controlling a bank of neural networks speed convergence and allow the use of higher compression ratios for `simple' patterns. The adaptation and generalization capabilities inherent in EPIC also facilitate progressive transmission of images through varying the number of quantization levels used to represent compressed patterns. Average compression ratios of 7.51:1 with an averaged average mean squared error of 0.0147 were achieved.
The Role of the PAX8/PPARγ Fusion Oncogene in the Pathogenesis of Follicular Thyroid Cancer

When identified at early stages, most well-differentiated thyroid cancers are readily treated and yield excellent outcomes. Follicular thyroid cancer (FTC) however, when diagnosed at a late stage, may be very resistant to treatment, and exhibits 10-year survival rates less than 40%. Despite substantial progress in recent years, we still have limited understanding of the molecular and biological interrelationships between the various subtypes of benign and malignant follicular thyroid neoplasms. In contrast to the wealth of information available regarding papillary thyroid carcinoma (PTC), the triggering mechanisms of FTC development and the major underlying genetic alterations leading to follicular thyroid carcinogenesis remain obscure. Recent studies have focused on a chromosomal translocation, t(2;3) (q13;p25), fusing PAX8, a transcription factor that is essential for normal thyroid gland development, with the peroxisome proliferator-activated receptor gamma (PPARγ), a member of the steroid/thyroid nuclear receptor family. This chromatin rearrangement results in the expression of a PAX8/PPARγ fusion protein, designated PPFP, whose incidence is relatively common in FTC and may represent an initiating event in the genesis of FTC. Here we review progress on the studies of PPFP that assess its involvement in FTC tumorigenesis.
At the leading edge of three-dimensional cell migration.

Cells migrating on flat two-dimensional (2D) surfaces use actin polymerization to extend the leading edge of the plasma membrane during lamellipodia-based migration. This mode of migration is not universal; it represents only one of several mechanisms of cell motility in three-dimensional (3D) environments. The distinct modes of 3D migration are strongly dependent on the physical properties of the extracellular matrix, and they can be distinguished by the structure of the leading edge and the degree of matrix adhesion. How are these distinct modes of cell motility in 3D environments related to each other and regulated? Recent studies show that the same type of cell migrating in 3D extracellular matrix can switch between different leading edge structures. This mode-switching behavior, or plasticity, by a single cell suggests that the apparent diversity of motility mechanisms is integrated by a common intracellular signaling pathway that governs the mode of cell migration. In this Commentary, we propose that the mode of 3D cell migration is governed by a signaling axis involving cell–matrix adhesions, RhoA signaling and actomyosin contractility, and that this might represent a universal mechanism that controls 3D cell migration.
Comparison of Martian and lunar geologic provinces

Mars and the moon have superficially similar dichotomies between old elevated terrain and young low-lying terrain. On Mars the older terrain contains much less basin and crater material and much more plains material than the older terrain on the moon. These elevated Martian plains, constituting the plateau plains province, are believed to be depositional, perhaps volcanic, in origin. Some of the plateau plains are equivalent in crater density to a province of old lunar mare material in Mare Australe but are much more extensive. Like their lunar equivalents, these plateau plains are believed to have formed while the impact flux was declining from an early torrential rate to a later much slower rate. Other, younger Martian plains generally are also considerably more extensive relative to planet size than their lunar equivalents.
Mathematical programming models of closed tandem queueing networks

Closed tandem queueing networks are an important class of queueing models. Common approaches for analyzing these systems include Markov processes, renewal theory, and random walks. This article presents optimization models for sample paths of closed tandem queues. These mathematical models provide a new tool for analyzing these queueing systems using the techniques and algorithms from mathematical programming, and from graph theory in particular. We then apply operators from computer graphics (electronic picture manipulation) to graph theoretic representations of discrete-event system dynamics to establish some fundamental mathematical properties for these queueing systems.
On selecting the best population

This paper deals with the problem of selecting the “best” population from a given number of populations in a decision theoretic framework. The class of selection rules considered is based on a suitable partition of the sample space. A selection rule is given which is shown to have certain optimum properties among the selection rules in the given class for a mal rules are known.
Apoptosis induced by cryo-injury in human colorectal cancer cells is associated with mitochondrial dysfunction.

Cryotherapy, a method of in situ ablation, is used in the treatment of colorectal liver metastases with variable results. During the treatment, the central area of treated tumor undergoes necrotic destruction by lethal cryo-injury; however, the cellular response of tumor exposed to sublethal cryo-injury at the peripheral zone is unclear. In our study, we have identified the induction of apoptosis by cryo-injury at −10°C in 4 colorectal cancer cell lines (HT29, HCT116, KM12C and KM12SM). The apoptosis was characterized by chromatin condensation, transferase-mediated dUTP nick end-labeling (TUNEL) staining, proteolytic cleavage of poly(ADP-ribose) polymerase (PARP) and cytokeratin 18, and activation of caspase-3. The occurrence and intensity of cryo-induced apoptosis did not correlate with the functional status of p53 in the cell lines studied. The expression of anti-apoptotic proteins (Bcl-2, Bcl-XL) and pro-apoptotic proteins (Bax, Bcl-XS, Bad, and Bak) in response to cryo-injury varied in this cell line panel. The basal level of Bcl-2/Bax protein ratio correlated inversely to the apoptotic rate. We further demonstrated that Bax level decreased in cytosol and increased in mitochondria, followed by a loss of mitochondrial membrane potential after cryo-injury in HT29 cells. These findings indicate that cryo-injury induces apoptosis in colorectal cancer cells via disruption of mitochondrial integrity. The cryo-induced apoptosis was also identified in a nude mouse tumor xenograft model. Our elucidation of the apoptosis pathway induced by cryo-injury implies that synergistic combination of cryosurgery with pharmacological agents that augment of apoptosis induction may have clinical relevance in treating colorectal liver metastasis. © 2002 Wiley-Liss, Inc.
Going green doesn't kill jobs

Claims that environmental regulations will worsen the unemployment crisis are false. When the economy is struggling the exact opposite is true, says Josh L. Bivens
MEGA---the maximizing expected generalization algorithm for learning complex query concepts

Specifying exact query concepts has become increasingly challenging to end-users. This is because many query concepts (e.g., those for looking up a multimedia object) can be hard to articulate, and articulation can be subjective. In this study, we propose a query-concept learner that learns query criteria through an intelligent sampling process. Our concept learner aims to fulfill two primary design objectives: (1) it has to be expressive in order to model most practical query concepts and (2) it must learn a concept quickly and with a small number of labeled data since online users tend to be too impatient to provide much feedback. To fulfill the first goal, we model query concepts in k-CNF, which can express almost all practical query concepts. To fulfill the second design goal, we propose our maximizing expected generalization algorithm (MEGA), which converges to target concepts quickly by its two complementary steps: sample selection and concept refinement. We also propose a divide-and-conquer method that divides the concept-learning task into G subtasks to achieve speedup. We notice that a task must be divided carefully, or search accuracy may suffer. Through analysis and mining results, we observe that organizing image features in a multiresolution manner, and minimizing intragroup feature correlation, can speed up query-concept learning substantially while maintaining high search accuracy. Through examples, analysis, experiments, and a prototype implementation, we show that MEGA converges to query concepts significantly faster than traditional methods.
Genome Informatics: The Role of DNA in Cellular Computations

Cells are cognitive entities possessing great computational power. DNA serves as a multivalent information storage medium for these computations at various time scales. Information is stored in sequences, epigenetic modifications, and rapidly changing nucleoprotein complexes. Because DNA must operate through complexes formed with other molecules in the cell, genome functions are inherently interactive and involve two-way communication with various cellular compartments. Both coding sequences (data files) and repetitive sequences (generic formatting signals) contribute to the hierarchical systemic organization of the genome. By virtue of nucleoprotein complexes, epigenetic modifications, and natural genetic engineering activities, the genome can serve as a read‐write storage system. An interactive informatic conceptualization of the genome allows us to understand the functional importance of DNA that does not code for protein or RNA structure, clarifies the essential multidirectional and systemic nature of genomic information transfer, and emphasizes the need to investigate how cellular computation operates in reproduction and evolution.
Regulation of Gβγi-dependent PLC-β3 activity in smooth muscle: inhibitory phosphorylation of PLC-β3 by PKA and PKG and stimulatory phosphorylation of Gαi-GTPase-activating protein RGS2 by PKG.

In gastrointestinal smooth muscle, agonists that bind to Gi-coupled receptors activate preferentially PLC-β3 via Gβγ to stimulate phosphoinositide (PI) hydrolysis and generate inositol 1,4,5-trisphosphate (IP3) leading to IP3-dependent Ca2+ release and muscle contraction. In the present study, we identified the mechanism of inhibition of PLC-β3-dependent PI hydrolysis by cAMP-dependent protein kinase (PKA) and cGMP-dependent protein kinase (PKG). Cyclopentyl adenosine (CPA), an adenosine A1 receptor agonist, caused an increase in PI hydrolysis in a concentration-dependent fashion; stimulation was blocked by expression of the carboxyl-terminal sequence of GRK2(495–689), a Gβγ-scavenging peptide, or Gαi minigene but not Gαq minigene. Isoproterenol and S-nitrosoglutathione (GSNO) induced phosphorylation of PLC-β3 and inhibited CPA-induced PI hydrolysis, Ca2+ release, and muscle contraction. The effect of isoproterenol on all three responses was inhibited by PKA inhibitor, myristoylated PKI, or AKAP inhibitor, Ht-31, whereas the effect of GSNO was selectively inhibited by PKG inhibitor, Rp-cGMPS. GSNO, but not isoproterenol, also phosphorylated Gαi-GTPase-activating protein, RGS2, and enhanced association of Gαi3-GTP and RGS2. The effect of GSNO on PI hydrolysis was partly reversed in cells (i) expressing constitutively active GTPase-resistant Gαi mutant (Q204L), (ii) phosphorylation-site-deficient RGS2 mutant (S46A/S64A), or (iii) siRNA for RGS2. We conclude that PKA and PKG inhibit Gβγi-dependent PLC-β3 activity by direct phosphorylation of PLC-β3. PKG, but not PKA, also inhibits PI hydrolysis indirectly by a mechanism involving phosphorylation of RGS2 and its association with Gαi-GTP. This allows RGS2 to accelerate Gαi-GTPase activity, enhance Gαβγi trimer formation, and inhibit Gβγi-dependent PLC-β3 activity.
The genus Epitrimerus Nalepa, 1898 and the pear rust mite, Epitrimerus pyri (Nalepa, 1891) (Prostigmata: Eriophyidae)

Abstract Confusion and many errors in the literature regarding the genus Epitrimerus and the pear rust mite Epitrimerus pyri (Nalepa, 189Id ), a vagrant eriophyid species sometimes injurious to the leaves of the common pear, Pyrus communis L. (Rosaceae), are discussed. The current taxonomic status is presented.
Twins and other multiples: progress with a price

Progress is not without its price. This saying holds true for the discipline of obstetrics and gynecology, and those interested in multiple births. During the past two decades significant advances have been made in the specific area of infertility treatment. These changes have not been confined solely to in vitro fertilization (IVF) techniques and other operative technologies, but have also resulted from the increasingly widespread use of agents to induce ovulation. Whereas the operative interventions in question were designed by and remain in the hands of ‘specialists’ within our discipline, the use of hormonal agents to stimulate ovulation, originally introduced for use by the specialist, presently are prescribed by general obstetrician-gynecologists and, in many circumstances, by general practitioners with little or no training in obstetrics and gynecology. The combination of these two circumstances has led to at least two clearly identifiable effects. The first is that the number of patients undergoing infertility treatment has increased dramatically; this is the progress. The second is that the number of multiple births has increased in an equal fashion. Justly or unjustly, this latter effect has been characterized as an ‘epidemic and represents the price of progress. To be sure, other factors affecting the rate of multiple births have also been at work, although their effect is not always easy to quantitate. One such factor has been well described however, This is the age of mothers at the time of their first birth. If statistics from the United States are indicative of international trends, and they may well be as more and more developing nations achieve success in their quest for a better quality of life for women, the number of women delaying their first pregnancies by later marriage, contraceptive usage, or both, is increasing at an astounding rate. According to Luke [l], the proportion of all births to American women age 30 and older nearly doubled (from 16.9 to 30.2%) between 1973 and 1990, and
Measurements of loss tangent and permittivity at 60 GHz using an open resonator

A new 60 GHz open resonator system has been developed to measure the permittivity and loss tangent of low-loss microwave and millimeter wave hard substrate materials. The system uses a new measurement method namely the cavity-length variation technique to determine the position difference and the profile of the resonance peak with and without the specimen for the calculation of the permittivity and loss tangent. A 20-nanometer length resolution is reached for the variation of the cavity length. This new technique provides an interferogram containing a number of resonance peaks with and without the specimen each having a complete Gaussian or Lorentzian profile. The real part of the dielectric permittivity and loss tangent can now be determined accurately. It is no longer necessary to use a stable, wide- band and tunable frequency source. The accurate data for some hard substrate materials is obtained, excellent agreement is obtained between the new data and the data extrapolated from the Fourier Transform Spectroscopy technique measurements.
(U–Th)/Ne and multidomain (U–Th)/He systematics of a hydrothermal hematite from eastern Grand Canyon

A hydrothermal hematite from the Redwall Limestone in eastern Grand Canyon (Arizona, USA) was analyzed for (U–Th)/He and (U–Th)/Ne systematics. The dense polycrystalline aggregate has U and Th concentrations of ∼16 ppm each. Neon produced by α particle capture on ^(18)O is abundant in the sample—it constitutes ∼90% of total ^(21)Ne and indicates a (U–Th)/Ne age of 217±5 Ma. This value provides a lower bound for the formation age of the sample but detailed interpretation is not possible given the current absence of neon diffusion data for hematite. The 130±2 Ma (U–Th)/He age is much younger than the Ne age and therefore must be a cooling age. Highly reproducible step-heating He release experiments reveal the existence of a spectrum of diffusion domain sizes spanning about 3 orders of magnitude in radius, corresponding to He closure temperatures ranging from <0 to ∼150 °C. These domains may correspond to crystallites in the specimen, which are observed to range from smaller than a few nm to a few μm. ^4He/^3He age spectra acquired from the same experiments define a distinctive sigmoidal shape with step ages increasing monotonically from 0 to ∼210 Ma. This pattern clearly records the presence of the multiple domains as the hematite acquired its radiogenic helium. Coupling of the ^4He/^3He spectra and the diffusion data allow modeling of permissible time–temperature paths experienced by the hematite. These paths can be compared with independent thermal history reconstructions for eastern Grand Canyon characterized by ∼170 m.yr. of sedimentary burial followed by regional unroofing and canyon incision beginning at ∼80 Ma. The unroofing portion of the path inferred from the hematite is in good agreement with apatite (U–Th)/He and fission-track data. The results permit rapid cooling in Late Cretaceous–early Tertiary time, suggest a subsequent period of slow cooling through temperatures of ∼50–70 °C, with accelerated cooling ensuing after 20 Ma. In contrast, the hematite data demand temperatures in some part(s) of the Mesozoic that are at least 100 °C hotter than expected based on burial depth estimates. This may indicate that the sample experienced a reheating event associated with the passage of fluids similar to those observed at nearby mineralized breccia pipes. Overall these data provide motivation for further work to understand He and Ne behavior in hematite and their potential use in thermochronometry.
Incorporating solid solutions in reactive transport equations using a kinetic discrete-composition approach

Abstract A new approach is proposed for incorporating solid solution reactions into mass conservation equations describing reaction paths in both closed and open systems. The method is applicable to problems involving advective, dispersive, and diffusive transport in a porous medium. By representing the continuously variable solid solution composition with a discrete set of stoichiometric solids that span composition space, combined with a kinetic formulation of their rates of reaction, a self-determining spatial and temporal evolution of the solid solution concentration and composition is obtained. It is demonstrated that equilibrium of an aqueous solution with a stoichiometric solid derived from a solid solution corresponds to equilibrium of the solid solution itself if and only if equilibrium of the stoichiometric solid is stable. One advantage of this approach is that it is unnecessary to introduce any additional compositional variables to represent the solid solution. Discretization may be over the entire range of composition space, or over some subset depending on the system. A major consequence of the kinetic discrete-composition solid solution representation is that modeling solid solutions is similar to modeling pure mineral phases with the exception of a weighting factor applied to reaction rates of stoichiometric solids corresponding to a common solid solution. With this approach, precipitation leads to a discrete zonation of the solid solution that approximates the continuous variation in composition expected for the actual solid solution. The approach is demonstrated for a hypothetical ideal and non-ideal binary solid solution A x B 1− x C for a reaction path formulation and reactive transport involving advection and diffusion.
On Brownian Movement and irreversibility

Abstract The distinction between reversible and irreversible systems is usually made by examining whether the “equations of motion” are invariant or otherwise under time reversal. We consider here instead a criterion in terms of the time-dependence of the spontaneous fluctuations of the system. This leads us subsequently to consider the physical significance of the usual quantum modifications of the Brownian Movement formulae, and we are led to suggest that there are rather fundamental difficulties in dealing with simple irreversible systems when hf > kT. In particular we suggest that an irreversible description in terms of viscosity, friction, etc. in a thermal environment can only be valid over long enough time intervals, t, such that at least t a h kT .
Carotid Artery Stenting Before CABG: A Better Alternative to Treat Concomitant Coronary and Carotid Artery Disease

To the Editor: We read with great interest the article published recently “Is There Any Benefit From Staged Carotid and Coronary Revascularization Using Carotid Stents?” by Randall et al.1 In our institution, we have a clinical research protocol regarding the management of patients with concomitant coronary and carotid artery disease.2 To date we have treated 37 patients who have had concomitant surgical coronary artery disease and significant carotid artery disease with staged-combined …
Subcooled boiling pressure drop with water at low pressure

Abstract Results are presented for an experimental study of pressure drop with subcooled boiling of water at pressures below 100 p.s.i.a. in horizontal round tubes of diameter less than 0·2 in. Test conditions were comparable to those required for the cooling of high power density systems. A correlation is presented in graphical form which satisfactorily accounts for variations in velocity, pressure, and inlet temperature. The correlation is in good agreement with the limited data reported by other investigators for similar conditions. Application of the data to diagnosis of system stability is noted.
Clevelandodendron ohioensis, Gen. et sp. nov., A Slender Upright Lycopsid from the Late Devonian Cleveland Shale of Ohio

Clevelandodendron ohioensis Chitaley & Pigg gen. et sp. nov. is an almost entire lycopsid plant known from a single compressed specimen from the Cleveland Shale member of the Upper Devonian Ohio Shale. This unique specimen is 125 cm long, consisting of an unbranched, slender, monopodial axis with a partially preserved plant base bearing thick appendages at one end, and a compact, terminal ovoid bisporangiate strobilus at the other. The stem is 2 cm wide for most of its length. Visible on the decorticated stem surface are helically arranged, elongate leaf traces and laterally compressed, slender leaves along the stem margin. The plant base bears 4-6 thick appendages. The terminal strobilus is compact, ovoid, 9 cm long and up to 6 cm wide, morphologically similar to those of some Lepidodendrales, and bears helically arranged sporophyll/sporangium complexes with narrow bases and distal laminae up to 18 mm long, turned upward. Megaspores are 320360 lim, trilete and laevigate, lacking a gula; microspores are 30-42 pm, trilete, indistinctly punctate and possibly assignable to Calamospora or Punctatisporites. Clevelandodendron demonstrates that slender unbranched lycopsids with an isoetalean plant habit similar to the Carboniferous genera Chaloneria and Sporangiostrobus and Triassic Pleuromeia-like forms were present as early as the Late Devonian. The early occurrence of this unique habit suggests that diversification within the isoetalean clade sensu Rothwell and Erwin (including both Isoetales and Lepidodendrales) was well established prior to the Carboniferous.
On intracluster Faraday rotation. II - Statistical analysis

The comparison of a reliable sample of radio source Faraday rotation measurements seen through rich clusters of galaxies, with sources seen through the outer parts of clusters and therefore having little intracluster Faraday rotation, indicates that the distribution of rotation in the former population is broadened, but only at the 80% level of statistical confidence. Employing a physical model for the intracluster medium in which the square root of magnetic field strength/turbulent cell per gas core radius number ratio equals approximately 0.07 microgauss, a Monte Carlo simulation is able to reproduce the observed broadening. An upper-limit analysis figure of less than 0.20 microgauss for the field strength/turbulent cell ratio, combined with lower limits on field strength imposed by limitations on the Compton-scattered flux, shows that intracluster magnetic fields must be tangled on scales greater than about 20 kpc.
Helium charged particle radiotherapy for meningioma: Experience at UCLBL

Abstract Purpose: Evaluate the use of helium charged particle radiotherapy in the treatment of residual or unresectable meningioma adjacent to critical structures. Methods and Materials: Twenty-nine patients with meningioma of the skull base or spine were irradiated with helium charged particle radiotherapy at the University of California Lawrence Berkeley Laboratory (UCLBL) during the period 1981–1992. Twenty-six patients were treated for intracranial and three for spinal tumors. Total doses of 53.0–80.4 Gray equivalent (GyE) with a mean of 63 GyE were delivered using the helium ion beam. Results: Ten-year local control and survival rates calculated by the Kaplan-Meier product limit method were 84% and 80% respectively. Doses of 60.0 GyE were delivered with a low rate of complications. The only failures were in massive, recurrent tumors. Conclusion: High doses using helium charged particle radiotherapy can be safely and effectively delivered to large residual or unresectable meningioma near radiosensitive structures.
Stiffness Control of a SMA Actuator

This paper presents a control of stiffness for an actuator that utilizes the properties of shape memory alloy (SMA) wires. The control algorithm is developed based on angular position of the SMA actuated arm. The model for calculation of stiffness is prepared in MATLAB/Simulink environment. In this application, a PID controller is designed to regulate the applied voltage of the SMA wire. For all the experiments, dSPACE hardware-in-the-loop solution is used. Simulation and experimental results are collected to validate system model. Result show good performance and control of stiffness through PID control system.Copyright © 2009 by ASME
WyomingView: No-Cost Remotely Sensed Data for Geographic Education.

Abstract Learning enhanced by visual examples and remotely sensed imagery is a valuable classroom resource for teaching students geographic concepts in a meaningful context. Barriers to the use of imagery include difficulty finding appropriate imagery and the cost of moderate resolution satellite imagery. A program in Wyoming called WyomingView and analogous programs in other states are providing no-cost, preprocessed satellite imagery delivered over the Internet that can help teachers better communicate geospatial knowledge to their students.
Ordered Multilayer Nanocomposites Prepared by Electrostatic Layer-by-Layer Assembly between Aluminosilicate Nanoplatelets and Substituted Ionic Polyacetylenes

Ordered multilayer nanocomposites have been prepared by electrostatic layer-by-layer assembly between exfoliated aluminosilicate nanoplatelets and substituted ionic polyacetylenes. Aluminosilicate saponite particles were exfoliated by means of extensive shaking and sonication of their water suspension. Atomic force microscopy and transmission electron microscopy data suggest that the exfoliated platelets have the shape of ultrathin disks with an average width of 170 ± 30 nm. Conjugated ionic polyacetylene poly(N-octadodecyl-2-ethynylpyridinium bromide) (PEPy-C18) was synthesized by spontaneous polymerization of 2-ethynylpyridine quaternized with 1-bromooctadecane. Linear build-up of multilayer nanocomposites between the exfoliated saponite particles and substituted ionic polyacetylenes was monitored by UV−vis absorption spectroscopy. AFM surface topography of the resulting films indicates that the saponite platelets cover the entire surface of the underlying layers. TEM cross-sectional images of such film...
Kinetics of n-species annihilation: Mean-field and diffusion-controlled limits.

We consider the kinetics of a system where n distinct chemical species ${A}_{i}$ undergo the reactions ${A}_{i}$+${A}_{j}$\ensuremath{\rightarrow}inert (i\ensuremath{\ne}j). In the rate-equation approximation, a conservation law for the reaction is derived, and an explicit solution for the case n=3 is given. At the level of the master equation, Van Kampen's \ensuremath{\Omega} expansion is employed to estimate the magnitude of local fluctuations in density which arise when the basic dynamical variable of the system is the (discrete) particle number, rather than a continuous particle density. We then develop a physical picture for the evolution of the n-species system, when the particles diffuse, which, together with the estimate of the magnitude of the local fluctuations, is used to deduce the form of the decay law when the initial densities of the n species are equal. For a d-dimensional n-species system below an upper critical dimension equal to 4(n-1)/(2n-3), the density is predicted to decay as ${t}^{\mathrm{\ensuremath{-}}\ensuremath{\alpha}(n)}$, with \ensuremath{\alpha}(n)=1/2d{1-1/[2(n-1)]}, and this is verified by numerical simulations. In addition, the simulations reveal a striking symmetry breaking, where the equal-density initial state evolves to a long-time state where one species predominates.
THIN-LAYER AND PAPER CHROMATOGRAPHIC ANALYSES OF THE CARBOHYDRATES IN THE CELL WALL OF CHLORELLA PYRENOIDOSA 7-11-05.

THE monosaccharide composition of isolated cell walls of strain 7–11–05 of Chlorella pyrenoidosa Chick, an organism proposed for life-support systems in space travel, was examined. The two principal methods used were thin-layer chromatography and paper chromatography, accompanied by appropriate staining.
Legislative role performance of female legislators

Women members of the United States House of Representatives for the 91st and 93rd Congresses are compared with male members to test whether there is a significant difference in their legislative behavior in the following areas: liberalism-conservatism, dependency-independence, specialization, and effectiveness. Only in the area of specialization is there reasonable statistical support for the hypothesis of significant difference. Women did introduce legislation relating to health, education, welfare and other social concerns at a slightly higher rate than males, but this still represented only about one-fourth of their legislation.
Computation of phase and chemical equilibrium, part IV: Approach to chemical equilibrium

The Rand algorithm for calculation of compositions in phase and chemical equilibrium is extended to permit specifications of extents of reactions that cannot be taken at equilibrium. Pseudo-Gibbs free energies of formation are introduced to permit specification of temperature approaches. The extended algorithm is demonstrated for methane reforming.