cssi/SciSciGPT-SciSciNet huggingface dataset:
Transformations of Cauchy Matrices, Trummer's Problem and a Cauchy-Like Linear Solver

Computations with dense structured matrices are ubiquitous in sciences, communication and engineering. Exploitation of structure simplifies the computations dramatically but sometimes leads to irregularity, e.g. to numerical stability problems. We will follow the line of [P90], [PLST93], [PZHY97] by exploiting the transformations among the most celebrated classes of structured matrices (that is, among the matrices of Toeplitz, Hankel, Cauchy and Vandermonde types), as a general tool for avoiding irregularity problems and improving computations with the structured matrices of the above classes. In this paper we apply the transformation techniques to Trummer's problem of multiplication of a Cauchy matrix by a vector and to multipoint polynomial evaluation, which should demonstrate the power of this general approach. In both cases (of Trummer's problem and polynomial evaluation) the resulting algorithms use only a few arithmetic operations, allow their effective parallelization and are stable numerically. The new transformations are described in sections 2–6. Subsequent sections reduce Cauchy-like matrix computations to recursive solution of Trummer's problem.
Coordinate Systems in Riemannian Space-Time: Classifications and Transformations; Generalization of the Poincaré Group

Coordinate conditions that can be specified prior to determination of the geometrical structure of space-time are investigated, and new methods of dividing all coordinate systems into ten parametric classes are introduced. They are based on finding the degree of freedom in specifying the metric tensor and its derivatives to arbitrary high order at one point. These methods are used to present an exact formulation of the following idea: the limitation of geometrical description to gravitation only induces a corresponding restriction on the degree of invariance of the laws of nature. Geodesic Fermi coordinates are studied in detail and the set of transformations between them is shown to form a “quasi-group” which is a natural generalization of the Poincare group to Riemannian space-time.
Soil moisture estimation in a semiarid watershed using RADARSAT-1 satellite imagery and genetic programming

[1] Soil moisture is a critical element in the hydrological cycle especially in a semiarid or arid region. Point measurement to comprehend the soil moisture distribution contiguously in a vast watershed is difficult because the soil moisture patterns might greatly vary temporally and spatially. Space-borne radar imaging satellites have been popular because they have the capability to exhibit all weather observations. Yet the estimation methods of soil moisture based on the active or passive satellite imageries remain uncertain. This study aims at presenting a systematic soil moisture estimation method for the Choke Canyon Reservoir Watershed (CCRW), a semiarid watershed with an area of over 14,200 km2 in south Texas. With the aid of five corner reflectors, the RADARSAT-1 Synthetic Aperture Radar (SAR) imageries of the study area acquired in April and September 2004 were processed by both radiometric and geometric calibrations at first. New soil moisture estimation models derived by genetic programming (GP) technique were then developed and applied to support the soil moisture distribution analysis. The GP-based nonlinear function derived in the evolutionary process uniquely links a series of crucial topographic and geographic features. Included in this process are slope, aspect, vegetation cover, and soil permeability to compliment the well-calibrated SAR data. Research indicates that the novel application of GP proved useful for generating a highly nonlinear structure in regression regime, which exhibits very strong correlations statistically between the model estimates and the ground truth measurements (volumetric water content) on the basis of the unseen data sets. In an effort to produce the soil moisture distributions over seasons, it eventually leads to characterizing local- to regional-scale soil moisture variability and performing the possible estimation of water storages of the terrestrial hydrosphere.
Effects of alcohol on histone deacetylase 2 (HDAC2) and the neuroprotective role of trichostatin A (TSA)

Background: Previous studies have implicated histone deacetylases (HDACs) and HDAC inhibitors (HDIs) such as trichostatin A (TSA) in the regulation of gene expression during drug addiction. Furthermore, an increase in HDAC activity has been linked to neurodegeneration. Alcohol has also been shown to promote abundant generation of reactive oxygen species (ROS) resulting in oxidative stress. TSA inhibits HDACs and has been shown to be neuroprotective in other neurodegenerative disease models. Although HDACs and HDIs have been associated with drug addiction, there is no evidence of the neurodegenerative role of HDAC2 and neuroprotective role of TSA in alcohol addiction. Therefore, we hypothesize that alcohol modulates HDAC2 through mechanisms involving oxidative stress. Methods: To test our hypothesis, the human neuronal cell line, SK-N-MC, was treated with different concentrations of ethanol (EtOH); HDAC2 gene and protein expression were assessed at different time points. Pharmacological inhibition of HDAC2 with TSA was evaluated at the gene level using qRT-PCR and at the protein level using Western blot and flow cytometry. ROS production was measured with a fluorescence microplate reader and fluorescence microscopy. Results: Our results showed a dose-dependent increase in HDAC2 expression with EtOH treatment. Additionally, alcohol significantly induced ROS, and pharmacological inhibition of HDAC2 with TSA was shown to be neuroprotective by significantly inhibiting HDAC2 and ROS. Conclusions: These results suggest that EtOH can upregulate HDAC2 through mechanisms involving oxidative stress and HDACs may play an important role in alcohol use disorders (AUDs). Moreover, the use of HDIs may be of therapeutic significance for the treatment of neurodegenerative disorders including AUDs.
Oracle database filesystem

Modern enterprise, web, and multimedia applications are generating unstructured content at unforeseen volumes in the form of documents, texts, and media files. Such content is generally associated with relational data such as user names, location tags, and timestamps. Storage of unstructured content in a relational database would guarantee the same robustness, transactional consistency, data integrity, data recoverability and other data management features consolidated across files and relational contents. Although database systems are preferred for relational data management, poor performance of unstructured data storage, limited data transformation functionalities, and lack of interfaces based on filesystem standards may keep more than eighty five percent of non-relational unstructured content out of databases in the coming decades.We introduce Oracle Database Filesystem (DBFS) as a consolidated solution that unifies state-of-the-art network filesystem features with relational database management ones. DBFS is a novel shared-storage network filesystem developed in the RDBMS kernel that allows content management applications to transparently store and organize files using standard filesystem interfaces, in the same database that stores associated relational content. The server component of DBFS is based on Oracle SecureFiles, a novel unstructured data storage engine within the RDBMS that provides filesystem like or better storage performance for files within the database while fully leveraging relational data management features such as transaction atomicity, isolation, read consistency, temporality, and information lifecycle management. We present a preliminary performance evaluation of DBFS that demonstrates more than 10TB/hr throughput of filesystem read and write operations consistently over a period of 12 hours on an Oracle Exadata Database cluster of four server nodes. In terms of file storage, such extreme performance is equivalent to ingestion of more than 2500 million 100KB document files a single day. The set of initial results look very promising for DBFS towards becoming the universal storage solution for both relational and unstructured content.
Use of Kalman filter methods in analysis of in-pile LMFBR accident simulations

Kalman filter methodology has been applied to in-pile liquid-metal fast breeder reactor simulation experiments to obtain estimates of the fuel-clad thermal gap conductance. A transient lumped parameter model of the experiment is developed. An optimal estimate of the state vector chosen to characterize the experiment is obtained through the use of the Kalman filter. From this estimate, the fuel-clad thermal gap conductance is calculated as a function of time into the test and axial position along the length of the fuel pin.
Isotretinoin therapy is associated with early skeletal radiographic changes

Eight patients with disorders of keratinization (six with ichthyosis, one with Darier's disease, and one with palmar-plantar keratoderma) were treated with isotretinoin for 9 months (1 patient) to 1 year (7 patients). The patients ranged from 5 to 26 years of age. The average isotretinoin dose was 2 mg/kg/day (range, 1.0–2.9 mg/kg/day). Radiographic skeletal surveys were performed prior to therapy, and after 6 months and 1 year of therapy. After 1 year of isotretinoin treatment, six of the eight patients had small but unequivocal skeletal hyperostoses. Five of the patients had multiple hyperostoses. While only two patients were judged to have hyperostoses after 6 months of isotretinoin therapy during prospective evaluation, retrospective comparison with the radiographs obtained after 1 year revealed skeletal hyperostoses after 6 months of treatment in an additional three patients. Between 6 months and 1 year of therapy, some of the hyperostoses remained unchanged while others had progressed. In three patients, hyperostoses were seen at 12 months that were not detectable at 6 months. Based on this prospective study of skeletal changes during isotretinoin therapy, we recommend that patients taking high doses of isotretinoin for long periods be monitored radiographically.
The effect of varying amounts of exogenous estradiol benzoate on estrous behavior in the rat.

Abstract Female rats were ovariectomized and given either 0.75, 3, 15 or 333 μg of estradiol benzoate (EB) subcutaneously. At varying times after EB injection, progesterone (P) was injected. Four to 6 hr after P injection, the females were tested for sexual receptivity with a male. The latency to exhibit lordosis was not affected by the level of exogenous EB. The length of time that the females remained sexually receptive was related to the level of exogenous EB.
Concerted Reactions of Charge Transfer and Covalent Bond Formation in Ionized Alkylbenzene−Isobutene Clusters. Copolymerization of Styrene−Isobutene and α-Methylstyrene−Isobutene Clusters

Mixed aromatic−isobutene clusters (Am.In, where A = toluene, p-xylene, mesitylene, 1,2,4-trimethylbenzene, styrene, and α-methylstyrene) have been ionized by resonant two-photon ionization in the vicinity of the aromatic's transition, and by two-photon ionization using 248 nm and 193 nm photons. Intracluster reactions leading to the formation of isobutene dimer cation C8H16•+ are observed following the two photon ionization of the binary clusters only when the aromatic precursor has an ionization potential greater than or equal to that of the isobutene dimer. The observation of this process in the gas phase and within clusters suggests that a similar initiation mechanism may take place in solution following the photoionization of an appropriate aromatic initiator. Evidence has been presented that points to the successive covalent additions of isobutene molecules on styrene and α-methylstyrene radical cations within the binary clusters. The intracluster reactions appear to yield two intermediate isomers. O...
Rapid turnover rate of the hippocampal synaptic NMDA-R1 receptor subunits

The decrease in the number of synaptic NMDA receptors produced by prior i.c.v. injections of antisense oligonucleotides was examined in the CA1 stratum radiatum of hippocampal slices. Isolated NMDA and AMPA receptor-mediated components of extracellular synaptic responses were compared in slices obtained from control animals and from animals treated for 48 h with an 18-mer phosphorothioate antisense oligodeoxynucleotide directed against NMDA-R1. In slices ipsilateral to the injected hemisphere, the synaptic NMDA component was decreased by 29% compared with the contralateral side and by 34% compared with animals injected with vehicle alone. At the same time, synaptic AMPA receptor-mediated components were not affected. These results are consistent with a rapid turnover rate of synaptic NMDA-R1 and demonstrate the feasibility of antisense oligonucleotide techniques for the depletion of specific synaptic receptor channels.
China's Push for Energy Raises Regional Security Concerns

China's increasing demand for energy is leading to a push to further exploit its own energy resources deposits, a leveraging of its growth market for favorable energy pricing, and conflicts with neighboring countries. Energy experts discussed China's efforts to bolster its energy resources, during a 17 September forum on energy and security issues in China and the Asia Pacific at the Woodrow Wilson International Center for Scholars in Washington, D. C.
Studies in the radiation resistance of plastic scintillators: review and prospects

With the planned construction of high-luminosity hadron colliders, the SSC (Superconducting Supercollider) and LHC (Large Hadron Collider), the issue of radiation resistance of detector components has arisen as a priority item. The radiation resistance of organic scintillators is discussed, with the dual goals of presenting a review of the problem and pointing the way to possible solutions. It is concluded that progress in producing sufficiently radiation-hard organic scintillators has been significant, but there remain many important details to be investigated. It is feasible that an organic scintillator may be produced within the next few years with a performance specification of 100 Mrad. >
Metal hydrides in engineering systems, processes, and devices: A review of non-storage applications

Abstract Metal hydrides have garnered much interest in scientific and engineering communities since their discovery in 1866 because of the wide range of applications they offer (Bowman et al. and Mueller et al.). A comprehensive review of selected applications involving metal hydrides in engineering systems, processes and devices has been presented in this paper. The applications of metal hydrides can be broadly classified into seven distinct categories, which are: 1) thermal systems, 2) energy systems, 3) actuation and sensing, 4) processing, 5) semiconductors, 6) biomimetic and biomedical systems, and 7) nuclear applications in addition to hydrogen storage. There have been several brilliant reviews published on hydrogen storage in metal hydrides. The focus of this review is on non-storage metal hydride applications. The fundamentals and working principles of engineering systems, processes, and devices based on metal hydrides have been concisely provided. Besides hydrogen storage, metal hydrides have been proposed and demonstrated for applications in hydrogen compressors, refrigerators, and actuators. Optical and electrical properties of hydrides can be exploited in the design of sensors and energy efficient windows. The hydriding and dehydriding processes are effective in preparing implants for osseointegration in addition to being economic. Certain hydride materials are more effective neutron moderators compared to the conventional ones in nuclear power plants. All such applications involving metal hydrides are revised and briefly discussed along with their working principles in this article.
Use of A2 kidneys for B and O kidney transplant recipients: report of a series of patients transplanted at a single center spanning a decade

DURING the past several years there has been an increased concern about the discrepancy in waiting times among patients with different ABO blood groups. Specifically, data from the U.S. Scientific Registry indicate that patients with blood group B wait significantly longer than A or O patients for a kidney transplant. Concurrently, there has been increased recognition of the fact that a subtype of ABO A may be a barrier that is permissible to cross in kidney transplantation. Donors who type for A2 represent approximately 20% of all A donors. These individuals’ red blood cells do not agglutinate with the antisera used to type for A1, their cells have a lower amount of A antigen, and they do not express the subtypes A3 and A4 in their kidneys. There is now a significant accumulated experience with using kidneys from these A2 donors for blood group O and B recipients. Use of A2 kidneys for O and B recipients can increase the donor pool for blood group B and O transplant candidates and decrease their waiting times. Moreover, this practice could increase the use of living donors, which can lead to better graft survival versus a non-living donor transplant. The following is a report of our successful experience with the transplantation of A2 kidneys into blood group O and B recipients.
Spider city sex

In her essay “Dungeon Intimacies” (2005) Susan Stryker offers “autoethnography” as a methodology for theorizing embodiment and politics. She invites us to see how corporeality situates more generalizable knowledges. Following Stryker, this essay explores male-to-female transsexual transitioning in an urban setting, San Francisco's Tenderloin, through bodily experience. These accounts might appear as drifts in personal recollection, but they are meant to suggest, however speculatively, and without aiming toward universalizing, the sensuous transaction between body and environment. Apprehending the interplay of sensation and place, I suggest, requires an attention to streets, buildings, and sidewalks, but also other non-humans. Guided by figural and literal spiders and the effects of hormone replacement therapy in the form of horse urine (Premarin), this essay proffers that transsexuality is relational in terms of social, economic, and political milieus as well as spatial, affective, and speciated registers.
Using Data Labels to Discover Moderating Effects in PLS-Based Structural Equation Modeling

PLS-based structural equation modeling is extensively used in e-collaboration research, as well as in many other fields of research. Two main types of exploratory analyses are frequently employed in the context of PLS-based structural equation modeling: covariance (or correlation) analyses, where the covariances (or correlations) among all variables are inspected; and model-driven exploratory analyses, where one or more variations of theory-supported models are built and adjusted associations among variables are inspected. These analyses, while useful, provide limited insights about the possible presence of moderating effects. We discuss a general approach through which researchers can employ data labels, implemented as symbols that are displayed together with legends on graphs, to uncover moderating relationships among variables. The discussion is illustrated with the software WarpPLS version 4.0. While the approach is illustrated in the context of e-collaboration research, it arguably applies to any field where PLS-based structural equation modeling can be used.
Flux of morphine, fentanyl, and alfentanil through rabbit arteries in vivo. Evidence supporting a vascular route for redistribution of opioids between the epidural space and the spinal cord.

BACKGROUND It has been suggested that opioids may move from the epidural space to the spinal cord by way of the spinal radicular arteries. However, there are no data that address this proposed mechanism. The goal of the current study was to determine whether the radicular arterial supply of the spinal cord is a viable route for movement of opioids between the epidural space and spinal cord. METHODS The carotid and femoral arteries of anesthetized rabbits were exposed, ligated distally, and cannulated proximal to the ligature. A fluid reservoir was placed around the study vessel and filled with saline buffered to pH = 7.4 or 9.0. The study drug (morphine, fentanyl, or alfentanil) and a radiolabeled tracer were added to the reservoir. Blood was collected as it flowed through the arterial segment bathed by the fluid reservoir and analyzed by scintillation counting to determine how much drug diffused through the arterial wall per minute. RESULTS Relative flux rates through the carotid artery at pH = 7.4 were alfentanil flux > fentanyl > morphine. Increasing the pH to 9.0 resulted in a significant decrease in fentanyl's flux, but no significant change in alfentanil's or morphine's flux. In addition, the data demonstrate a biphasic relationship between octanol:buffer distribution coefficient and transarterial flux rates. CONCLUSIONS Because the critical step in transporting drug via radicular arteries is diffusion through the radicular artery wall, these data support the idea that drugs may gain direct access to the spinal cord by diffusing into the radicular arteries as they traverse the epidural space en route to the spinal cord.
Iron Uptake and Release by Macrophages is Sensitive to Propranolol

In this study we have tested the effects of d-propranolol (D-Pro) on the iron uptake, iron release and oxidative response of iron-loaded cells in a cellular model of iron-overload using isolated rat peritoneal macrophages incubated with iron-dextran (Fe-D). Pretreatment of macrophages with D-Pro (5–200 μ M) prior to Fe-D exposure decreased the cellular iron content and partially prevented iron release from latex-activated macrophages. Release of reactive oxygen species from activated cells was detected by dichlorodihydrofluorescein (DCDHF, 5 μ M) oxidation. We found that loading cells with Fe-D increased their response to latex, which was prevented by the lysosomotropic antioxidant agent D-Pro (10 μ M).
Methodology for determining multilayered temperature inversions

Abstract. Temperature sounding of the atmospheric boundary layer (ABL) and lower troposphere exhibits multilayered temperature inversions specially in high latitudes during extreme winters. These temperature inversion layers are originated based on the combined forcing of local- and large-scale synoptic meteorology. At the local scale, the thermal inversion layer forms near the surface and plays a central role in controlling the surface radiative cooling and air pollution dispersion; however, depending upon the large-scale synoptic meteorological forcing, an upper level thermal inversion can also exist topping the local ABL. In this article a numerical methodology is reported to determine thermal inversion layers present in a given temperature profile and deduce some of their thermodynamic properties. The algorithm extracts from the temperature profile the most important temperature variations defining thermal inversion layers. This is accomplished by a linear interpolation function of variable length that minimizes an error function. The algorithm functionality is demonstrated on actual radiosonde profiles to deduce the multilayered temperature inversion structure with an error fraction set independently.
Onset of structural transformation in thorium metal at high pressures

This paper reports that novel phases of metals are formed under high pressures as a result of the rearrangement of electrons in different energy bands. Diamond anvil cells can produce calibrated static pressures of several million atmospheres and materials can be studied in-situ with synchrotron x-ray diffraction sources. Metals, in particular, show a wide variety of phase transformations driven by changes in the electronic structure with pressure. Electron transfer from one band to another is believed to be the cause of several high pressure transformations in rare earth, actinide and transition metals. At one atmosphere, the actinide metal thorium (Th), has an unoccupied 5f band approximately 4 eV wide located 1.5 eV above the Fermi energy. At high pressures, due to the relative movement of various energy bands, the 5f band should cross the Fermi energy. As a result, the 5f band becomes occupied at high pressures due to electron transfer from the sd-band. This electronic transition is expected to cause structural transformation. Th crystallizes into the face centered cubic (FCC) phase at ambient conditions. X-ray diffraction studies have been carried out on Th up to pressures of 30 GPa(6), 65 GPa(7) and 100 GPa(8).
Twenty-first-century drug warriors: the press, privateers and the for-profit waging of the war on drugs

The privatization of war-making — especially in regard to the waging of the war on terror — is well documented, but there are other emerging markets for the burgeoning ‘private security industry’. ...
Exsolution of Ca-amphibole from glaucophane and the miscibility gap between sodic and calcic amphiboles

Transmission and analytical electron microscopy (TEM/AEM) of glaucophane from glaucophane + Ca-amphibole-bearing blueschist and eclogite from two Vermont localities (Ecologite Brook and Tillotson Peak) and one California locality (Cazadero) has revealed the first evidence from exsolution for the miscibility gap between sodie and calcic amphiboles. The Tillotson Peak samples and the Cazadero samples contain coarsegrained glaucophane—actinolite pairs, while the Eclogite Brook samples contain coexisting glaucophane and actinolitic hornblende. Ca-rich glaucophanes contain abundant fine-scale lamellae of Ca-rich amphibole. These lamellae are usually oriented near (100) and \(\overline 2 01\). High-resolution TEM (HRTEM) images show them to be coherent. The exsolution lamellae are so narrow, beyond the resolution of AEM, that their true Ca contents are obscured by analytical contributions from the surrounding host. The AEM data suggest that the lamellae are either winchite or actinolite, depending on the true Ca concentration. In most cases, the exsolution lamellae have very curved interfaces and show variable orientation. This is attributed to the close similarity of unit-cell parameters for the two amphiboles. Three-dimensional optimal phase-boundary calculations using EPLAG (Fleet 1982) show that the observed “100” and “\(\overline 2 01\)” orientations are consistent with the minimization of area strain between the two lattices along the interface. Some samples show evidence for incipient exsolution in the form of homogeneously distributed, fine-scale precipitates. These results suggest that Ca-rich glaucophanes from other glaucophane—actinolite assemblages may be exsolved at the TEM scale. The coexisting amphiboles from Eclogite Brook also have been studied using the electron microprobe (EMP). The compositional gap defined by the Eclogite Brook pairs is consistent with previously reported results, but shows a wider break along the glaucophane—actinolite pseudobinary join, suggesting very limited solid solution up to temper-atures of about 500–550°C. The glaucophanes are relatively poor in Ca, except for one anomalous grain containing Ca-amphibole lamellae. Ferric iron, estimated by normalization to fixed cation numbers, is strongly partitioned into the actinolitic hornblende and the glaucophanes are very poor in the riebeckite component.
The reconstruction of environmental rights in urban South Africa

Rapid and spatially concentrated urbanization in South Africa has brought with it significant health and safety hazards. These hazards are described and analyzed through two optics: environmental rights and community participation. The rights perspective suggests that the system of apartheid led to a collapse of rural livelihoods, driving people to the cities, while apartheid's tight control over African residential location and employment ensured that high density settlement and unemployment would follow. The resulting urban environmental degradation and health and safety hazards are a violation of the human rights of the African residents of townships and informal settlements. The community participation perspective suggests that reconstruction can be linked to development and that community-based hazard identification and mitigation can be a vehicle for kick-starting urban revitalization.
Balancing learning and economies of scale for adaptive clinical trials

Abstract Prior to the start of an adaptive clinical trial, demand for an investigational drug can be highly uncertain. Treatment length, recommended dosages, and forecasted patient recruitment can fluctuate in response to early trial results. While initial demand forecasts can be very wrong, the factors influencing future demand can be learned during the trial. To take advantage of this learning, intra-trial production and/or packaging can be leveraged, but this is done at the expense of scale economies. In this paper, we study the balance between learning and economies of scale for adaptive clinical trials. We characterize the optimal production (or packaging) decisions and through analytical and numerical studies, we develop insights on the impact of fixed costs, learning rates in terms of forecasting future demand, inventory overage costs, and inventory underage costs on the value of having intra-trial flexibility and on decisions regarding quantity and timing of drug supply.
An HMMS Type Interactive Model for Aggregate Planning

For purposes of aggregate production smoothing, quadratic functions often produce good fits to data on some of the relevant incremental costs, such as inventory and overtime costs. However, when costs of hiring and laying off workers are described by smooth quadratic functions, the model solutions tend to involve very frequent minor workforce adjustments. Production managers are often unwilling to actually implement such decisions because changing workforce levels involves a great many intangible costs, many of which seem to defy meaningful analytic representation. In this paper an interactive model is developed where, through parametric analysis of a set of workforce constraints, a manager can establish the appropriate trade-offs between his judgmental estimates of hiring and firing costs and other more tangible production costs.
An electron microscopy and X-ray diffraction study of the microstructures of melt-drawn polyethylene films

Electron microscopy and X-ray diffraction have been used to study microstructures of melt-drawn polyethylene films. During the drawing process, uniplanar structures are formed which consist of crystals with theirb andc axes in the film plane. On annealing the films, the crystal size and orientation increase. Quantitative measures of the crystal thickness, lateral crystallite size and long period were obtained from bright-field and dark-field electron micrographs as well as from wide and small angle X-ray diffraction of stacked layers of the films.
Ionospheric Composition and Reactions: Our present knowledge of what ions are in the ionosphere, and why, is summarized.

Recent measurements of ion densities in the ionosphere seem to be more or less compatible with current data for ion-molecule reaction rates in some parts of the ionosphere under conditions in which a steady state prevails. There is no such agreement for the upper ionosphere, where the densities of He+ and H+ are difficult to understand in terms of present concepts concerning the relevant production and loss processes. Sources of ionizing radiation are needed to explain night- time observations in the E region and perhaps also in the F region. The D region remains a poorly understood laboratory of negative-ion and positiveion chemistry, where neither observation nor theory is as yet adequate.
On some extremal properties of algebraic polynomials

Abstract Let pn be an algebraic polynomial of degree n with real coefficients. Employing an inequality of G. Szegő, we study the extremal property of the integral f−11 (p′n(x))2 (1 − x2) dx subject to the constraint ∥pn∥L∞ ⩽ 1.
PERCEIVED STRESS AND RISK OF DEMENTIA IN OLDER ADULTS WITH AMNESTIC MILD COGNITIVE IMPAIRMENT

Background: Elevated stress is associated with memory deficits and decreased hippocampal volume, which is involved in both episodic and working memory. Stress may be a remediable risk factor for cognitive decline. We hypothesize that stress may predict the transition from aMCI to dementia. Methods: We recruited community residing older adults with aMCI from the Einstein Aging Study and followed them with annual assessments for dementia onset, defined by DSM-IV criteria. The baseline wave is the first wave where participants meet criteria for aMCI and have PSS results. Multivariate Cox regression analyses were conducted to examine the relationship between baseline PSS score and the subsequent onset of dementia. A "high stress" group was defined as the top quintile of PSS scores and the other 4 quintiles formed the "low stress" group. Results: We followed 111 individuals with aMCI and a mean baseline age of 83.2 years over an average of 2.6 years of follow-up (SD1⁄41.5), 30 (27%) participants developed incident dementia. Cox regression analyses showed that the high stress group had a statistically significant increase in risk of dementia (HR1⁄43.05; 95% CI:1.33-6.99) after adjusting for age, gender, race, years of education, and baseline aMCI status. After subsequent additional adjustments for baseline cognitive status, depression, and APOE e4 status, having high stress remained a significant risk for developing dementia (HR1⁄42.67; 95% CI:1.05-6.78). Conclusions: High levels of perceived stress were associated with an increased risk of incident dementia among those with aMCI. There also appears to be a threshold at which high stress increases the vulnerability for dementia. These findings suggest that stress reduction may reduce the risk of dementia in persons with aMCI.
Hierarchical Modeling in Geographic Information Systems: Population Interpolation Over Incompatible Zones

When inference is desired regarding some attribute of a particular geographic region, it often happens that data are not directly available for that region. However, it may be that data are available over the same general area, but reported according to a different set of regional boundaries. Recently, powerful computer programs called geographic information systems (GIS's) have enabled the simultaneous display of such "misaligned" datasets, but these systems address only the descriptive needs of the user, leaving the inferential goal unmet. In this article we describe a hierarchical Bayes approach, implemented via Markov chain Monte Carlo methods, which provides a natural solution to this problem through its ability to sensibly combine information from several sources of data and available prior information. After presenting a simple, idealized example to illustrate the method, we apply it to a dataset on leukemia rates in Tompkins County, New York, wherein we use block group-level covariate information to interpolate disease counts given only aggregate (census tract-level) summaries. We display our results graphically, using both statistical (S-plus) and GIS (ARC/INFO, MapInfo) software packages. The approach emerges as flexible, accurate, and suggestive of promising related methods for spatial smoothing of underlying relative risks.
NMR studies of NbSe3: Electronic structures, static charge-density-wave measurements, and observations of the moving charge-density wave.

We describe a series of $^{93}\mathrm{Nb}$ NMR studies of the charge-density-wave (CDW) conductor ${\mathrm{NbSe}}_{3}$. Using an aligned, multicrystalline sample, we have measured the complete shift tensors for the three Nb sites in the normal state. The results confirm a picture in which one chain is essentially insulating, and the other two are conducting. Studies below the 144-K CDW transition give well-resolved CDW-broadened line shapes, which indicate that the CDW is incommensurate with little or no lock-in to the lattice. Further NMR measurements performed with the CDW driven by electrical currents give information about the moving CDW. Motional narrowing of the NMR line indicates that the CDW conduction phenomena are associated with bulk motion of the ${\mathrm{NbSe}}_{3}$ CDW. On the other hand, the motion is irregular at all voltages, as indicated by the large voltage required for motional narrowing, the short ${T}_{2}$, and the behavior of the magnetization under current-induced saturation. Furthermore, NMR spin-echo measurements of the low-voltage dielectric response indicate a spatially nonuniform response of the CDW under its pinning barriers.
Bargaining power and artists' resale dividends

This paper explores the implications of models of bargaining power for issues having to do with the droit de suite, a legal right of graphic artists to a share in capital gains when a work of art is resold by the first purchaser. It is found that, if both artists and art buyers are risk averse, a positive resale share will be the outcome of a bargaining process that is Pareto-optimal as between the bargainers. This does not depend on bargaining power but is a form of risk-sharing, and to the extent that art buyers are risk averse will be preferred to a zero shareby the buyers. Since resale royalties are not ordinarily a feature of art sale contracts in the absence of legislation, this appears anomalous, and the paper explores alternatives to the received bargaining theory such as might correspond better with casual empiricism.
A re-investigation of evidence for cholinergic neuromuscular transmission in insects.

Although the bulk of recent evidence suggests that acetylcholine is not an excitatory transmitter at insect neuromuscular junctions, certain anomalies exist which required re-evaluation. Several drugs affecting cholinergic transmission were studied in isolated nerve muscle preparations of adult Periplaneta americana, Gromphadorhina portentosa and Locusta migratoria and larval trunk muscle of Samia cecropia. None of the drugs studied appears to affect neuromuscular transmission in these insects. However, eserine, nicotine, and nicotine analogs produce central effects, and several drugs including succinylcholine, nicotine, nicotine analogs and eserine appear to affect motor axons at high concentrations. ACh produced no effect on isolated leg preparations of cockroaches, but did produce a transient increase of kick force in jumping leg preparations of newly molted locusts. ACh (2.5 × 10−8 − 2.5 × 10−4M) had no effect on nerve muscle preparations of Gromphadorhina up to 20 days after nerve section, although spontaneous mechanical activity and deterioration of neuromuscular junctions were observed during this period. All preparations gave contractures to L-glutamate (pH 7.0); the threshold (2.5 × 10−4M) for this response did not change after denervation.
How Teachers Influence What Is Taught and Learned in Classrooms

search on Teaching (IRT) at Michigan State University, concerning how teachers determine the content that their students learn. It considers both the conscious decision making involved in selecting the curriculum to be taught to the students and the unwitting reductions and distortions introduced into this intended curriculum in the process of attempting to teach it. The Content Determinants project at IRT has considered the first question programmatically. This project evolved from earlier studies of the content included in widely used fourth-grade mathematics curricula and tests. These analyses revealed that there was a core of common content included in all or at least most of the three curricula and five tests sampled, but that this core usually consisted of less than half of the material included in any particular curriculum or test. Furthermore, there was wide variation in degree of overlap, so that some tests would be quite appropriate for use with a particular curriculum, but other tests would yield serious underestimates of the achievement actually produced (Freeman et al. 1980). These data raise important practical questions for school districts and individual teachers: should instruction concentrate on the content stressed in the curriculum or on the content stressed in the test? Consideration of this and related dilemmas led the Content Determinants group to study how decisions about the content of instruction are made. Who decides what constitutes the fourth-grade mathematics curriculum and
Patient satisfaction after carotid endarterectomy using a selective policy of local anesthesia.

Abstract Background: Patient satisfaction after carotid endarterectomy has not been specifically studied or reported. Results of carotid endarterectomy using either local or general anesthesia have been widely reported, and outcomes are not significantly different for either technique. Patient satisfaction data were obtained in order to determine whether patients preferred one method of anesthesia over another. Data regarding outcome may be added to the surgical literature as benchmark data when comparing operative carotid endarterectomy to newer techniques. Methods: During a 30-month period, 186 consecutive carotid endarterectomies were performed on 169 patients by a single surgeon with assistance from senior surgical residents. All patients were offered local anesthesia using a cervical block technique with intraoperative supplementation. Patients for whom local anesthesia was inappropriate or who declined were operated on using general endotracheal anesthesia. Results of operation were tabulated including indication for operation, method of anesthesia, intraoperative and postoperative complications, and mortality, and completion of a patient satisfaction survey form either on postoperative visit or by telephone questionnaire. Results: Of 169 patients who underwent carotid endarterectomy, 151 (89%) completed the satisfaction survey form. One hundred fourteen (62%) had local anesthesia and 71 patients (38%) had general anesthesia. There was 1 stroke (0.5%) and 1 death (0.5%) in the series. Perioperative complications including temporary cranial nerve injury, neck hematoma, myocardial infarction, and restenosis were noted and not significantly different in either the general anesthesia or local anesthesia group. Patient satisfaction data including intraoperative discomfort, postoperative pain, attentiveness of the operating room staff, and length of stay were all tabulated. There was no statistically significant difference in satisfaction between the general anesthesia group and the local anesthesia group (chi-square and Fisher’s exact test). Additionally, satisfaction with the procedure was extremely high. Conclusions: Patient outcome and perception of pain and recovery were not statistically significantly different in patients undergoing carotid endarterectomy using local anesthesia compared with general anesthesia. Overall patient satisfaction was extremely high. Patients should be offered carotid endarterectomy using an anesthesia technique with which the surgeon and patients are both comfortable, having confidence that the outcome is not related to anesthesia technique and that patients will be highly satisfied.
Recent developments in magnetocaloric materials

The recent literature concerning the magnetocaloric effect (MCE) has been reviewed. The MCE properties have been compiled and correlations have been made comparing the behaviours of the different families of magnetic materials which exhibit large or unusual MCE values. These families include: the lanthanide (R) Laves phases (RM2, where M = Al, Co and Ni), Gd5(Si1−xGex)4 ,M n(As1−xSbx), MnFe(P1−xAsx), La(Fe13−xSix) and their hydrides and the manganites (R1−xMxMnO3, where R = lanthanide and M = Ca, Sr and Ba). The potential for use of these materials in magnetic refrigeration is discussed, including a comparison with Gd as a near room temperature active magnetic regenerator material. (Some figures in this article are in colour only in the electronic version)
Finite element analysis of the stability of multilayer elastomeric bearings

Abstract The stability of multilayer elastomeric bearings is considered within the framework of two-dimensional finite elasticity. For this purpose, simple constitutive equations which generalize those of a transversally isotropic linear elastic solid are considered. A finite element formulation is discussed which is capable of accounting for very general boundary conditions. For moderate deflections and classical boundary conditions this formulation leads to numerical results in close correspondence with those obtained by Haringx's one-dimensional treatment. It is shown that the presence of boundary conditions in the form of unilateral constraints explains a softening effect which has been experimentally observed during the testing of this type of composite column. Experimental results are also presented which indicate that this softening effect is not produced by a form of material instability. These experimental results provide further justification for the simple constitutive model adopted.
Introspecting Phenomenal States

This paper defends a novel account of how we introspect phenomenal states, the Demonstrative Attention account (DA). First, I present a set of necessary and sufficient conditions for phenomenal state introspection which are not psychological, but purely metaphysical and semantic. Next, to explain how these conditions can be satisfied, I describe how demonstrative reference to a phenomenal content can be achieved through attention alone. This sort of introspective demonstration differs from perceptual demonstration in being non-causal. DA nicely explains key intuitions about phenomenal self-knowledge, makes possible an appealing diagnosis of blindsight cases, and yields a highly plausible view as to the extent of our first-person epistemic privilege. Because these virtues stem from construing phenomenal properties as non-relational features of states, my defense of DA constitutes a challenge to relational construals of phenomenal properties, including functionalism and representationalism. And I provide reason to doubt that they can meet this challenge.
Long-term effect of thrombolytic therapy on left ventricular ejection fraction after acute myocardial infarction.

Abstract To assess the long-term effect of thrombolytic therapy on left ventricular (LV) systolic function, 222 patients with acute myocardial infarction treated with intravenous tissue plasminogen activator within 4 hours of symptom onset underwent assessment of LV ejection fraction (EF) by radionuclide equilibrium angiography at hospital discharge and 1 year later. Mean EF at hospital discharge (46 ± 12) was similar to that at 1 year (45 ± 13). Stepwise multivariate linear regression analysis identified EF at discharge and patency of the infarct-related artery before discharge as independent predictors of EF change at 1 year (p = 0.0002 and 0.003, respectively). Random assignments to invasive versus conservative treatment strategies or to early versus delayed β-blocker therapy did not affect EF change during follow-up. No significant deterioration of EF was observed in patients with larger infarcts. However, EF decreased from 45 ± 10 at hospital discharge to 39 ± 12 (p = 0.005) at 1-year follow-up in a subgroup of patients with history of prior infarction. Thus, patients with acute myocardial infarction, treated with intravenous tissue plasminogen activator early after onset of symptoms, appear to have stable LV function between hospital discharge and 1 year follow-up. The change in EF between hospital discharge and 1 year can be predicted from the EF value at discharge, patency of the infarct-related artery before discharge and history of previous myocardial infarction.