cssi/SciSciGPT-SciSciNet huggingface dataset:
SKOPE-IT (Shareable Knowledge Objects as Portable Intelligent Tutors): overlaying natural language tutoring on an adaptive learning system for mathematics

This study investigated learning outcomes and user perceptions from interactions with a hybrid intelligent tutoring system created by combining the AutoTutor conversational tutoring system with the Assessment and Learning in Knowledge Spaces (ALEKS) adaptive learning system for mathematics. This hybrid intelligent tutoring system (ITS) uses a service-oriented architecture to combine these two web-based systems. Self-explanation tutoring dialogs were used to talk students through step-by-step worked examples to algebra problems. These worked examples presented an isomorphic problem to the preceding algebra problem that the student could not solve in the adaptive learning system. Due to crossover issues between conditions, experimental versus control condition assignment did not show significant differences in learning gains. However, strong dose-dependent learning gains were observed that could not be otherwise explained by either initial mastery or time-on-task. User perceptions of the dialog-based tutoring were mixed, and survey results indicate that this may be due to the pacing of dialog-based tutoring using voice, students judging the agents based on their own performance (i.e., the quality of their answers to agent questions), and the students’ expectations about mathematics pedagogy (i.e., expecting to solving problems rather than talking about concepts). Across all users, learning was most strongly influenced by time spent studying, which correlated with students’ self-reported tendencies toward effort avoidance, effective study habits, and beliefs about their ability to improve in mathematics with effort. Integrating multiple adaptive tutoring systems with complementary strengths shows some potential to improve learning. However, managing learner expectations during transitions between systems remains an open research area. Finally, while personalized adaptation can improve learning efficiency, effort and time-on-task for learning remains a dominant factor that must be considered by interventions.
Racism toward Hispanics

The topic of prejudice and racism is one that has occupied social psychology for many years. Almost every contemporary social psychology textbook has a chapter devoted to prejudice, discrimination, or interracial group relations, with numerous references to the studies conducted in these areas. How many of the studies discussed in these chapters, however, are based on research conducted with or about Hispanics? In order to answer this question, the present writer surveyed the relevant chapters of 17 contemporary and widely used social psychology textbooks. In the hundreds of studies referred to in these 17 textbooks in their discussion of prejudice and discrimination, only 4 studies dealt specifically with Hispanics. Does this mean that no research relevant to or indicative of prejudice against Hispanics has been conducted? Hardly. What this exclusion of Hispanics in social psychology textbooks demonstrates is an almost total lack of awareness concerning Hispanics as victims of prejudice and discrimination, and of the psychological literature that exists that is relevant to the Hispanic experience in this country.
Distributed Tree Structures for N-Body Simulation

Several particle simulation algorithms, such as the Barnes-Hut [1] and the Fast Multipole method [2], proceed by hierarchically decomposing the simulation space and representing the distribution of the simulated particles in an adaptive tree data structure which varies as the simulation proceeds. Such tree structures are also used in radiosity calculation, computational fluid mechanics, and other applications. Managing such a structure on a distributed-memory machine poses significant difficulties in terms of communication costs and partitioning strategies. The irregular nature of the structures rules out the usual optimization techniques used with arrays. Hand-coding these irregular and dynamic data structures is error-prone and not easily portable.
Circulating DNA in Cancer Diagnosis and Prognosis

Abstract The standard diagnostic approach to cancer relies on the analysis of a surgical or biopsy tumor sample from a primary or metastatic site obtained at a given time point. However, due to intratumoral heterogeneity and selection of different subpopulations in metastatic lesions, the analysis of a single tissue specimen will provide only a limited characterization of the molecular makeup of the disease. Monitoring of the molecular tumor characteristics by serial analyses of cell-free, circulating nucleic acids promises to capture the dynamic nature and heterogeneity of the disease and support monitoring and treatment decisions. The analysis of circulating cell-free tumor DNA is continuously evolving with improvements in detection limits and reduction of the operating costs and represents a set of research tools that is poised to enter clinical care. Here we will discuss cell-free circulating DNA, potential clinical applications, and current limitations and challenges.
Lung cancer staging: accuracy is critical.

Complete and accurate staging for patients diagnosed with lung cancer to assess the extent of disease is of critical importance so that appropriate treatment recommendations may be provided (1). An incorrect clinical staging classification can lead to wrong decisions on withholding potentially curative resection as well as inappropriate nonsurgical definitive therapy and palliative treatment options. In their study, Navani and colleagues analyzed the accuracy of clinical staging for stage I–IIIa non-small cell lung cancer (NSCLC) (2).
Two-Dimensional Beamforming Automotive Radar with Orthogonal Linear Arrays

We propose a new automotive radar architecture that achieves high resolution in range, range rate, azimuth and elevation angles while requiring smaller antenna aperture and fewer reception channels as compared to conventional digital beamforming planar arrays. This is achieved by leveraging two orthogonally-placed digital beamforming arrays using the frequency modulation continuous waveform. The high-resolution range-Doppler images generated by azimuth and elevation beams of the two arrays isolate each physical scatterer, thus, the azimuth and elevation angles can be precisely measured. To match the measurements of an object from azimuth and elevation beams, a deep learning based beam matching method is proposed, which converts the beam matching problem to an image patch matching problem in the range-Doppler domain. Furthermore, a new radar resource management algorithm is proposed, which schedules radar jobs by their time urgency as well as beam locations. Jobs fall into the same beams are scheduled together to optimally use the radar time resource and also reduces the computation introduced by the beam matching procedure. The advantage of the proposed radar is demonstrated by simulations.
Telepsychiatry and integrated primary care: setting expectations and creating an effective process for success

Telepsychiatry, especially in the form of live interactive videoconferencing, has greatly advanced the availability and use of specialist psychiatric consultations in primary care settings. Nevertheless, reliance on telepsychiatry, with corresponding decreases in direct face-to-face interaction between primary care providers and psychiatrists, can create unique challenges such as reducing the availability of non-verbal cues, and preventing the informal interactions that are so necessary for clarifying clinical and process details and for building essential team-based trust and rapport. Written from the perspective of an integrated psychiatrist, this article offers recommendations for a formal process to optimize virtual care coordination by setting clear expectations and providing communication tools for an effective and efficient telepsychiatry enabled integrated service.
Right Heart Failure from Carcinoid Syndrome

A 64-year old female with a prior history of a neuroendocrine tumor presented with exertional dyspnea and lower extremity edema. She previously was diagnosed with carcinoid syndrome, with frequent episodes of flushing, and was on monthly octreotide intramuscular injections. Physical exam was consistent with right-sided heart failure. Transthoracic echocardiography demonstrated findings consistent with carcinoid heart disease (CHD), including thickened, retracted tricuspid valve leaflets, severe tricuspid and pulmonary valve regurgitation, and severe right atrial and ventricular enlargement. Further imaging revealed extensive metastatic disease related to her underlying neuroendocrine tumor, with progression despite long-term therapy with a somatostatin analogue. Peptide Receptor Radionuclide Therapy (PRRT) was planned to slow the progression of her metastatic disease, with future surgical consultation for consideration of tricuspid and pulmonary valve replacements.
El teatro como ejercicio terapéutico en Todos somos el rey Lear, de Guillermo Schmidhuber

En Todos somos el rey Lear, escrita en 1979 y publicada en 1982, el dramaturgo mexicano Guillermo Schmidhuber de la Mora plantea clara intertextualidad con William Shakespeare. El presente estudio es una exploracion de como Schmidhuber teatraliza la creacion de hiperrealidad como proceso terapeutico no solo para ciertos personajes de la obra, sino tambien para el publico e, incluso, para el dramaturgo mismo. Con esta finalidad se emplean los conceptos de Jean Baudrillard sobre la hiperrealidad y el simulacro, las afirmaciones del mismo Schmidhuber sobre la dramaturgia, asi como tambien los conceptos psicologicos de Phil Jones sobre la drama-terapia y los efectos transformativos de este ejercicio teatral. Por medio de este proceso que resulta terapeutico, los personajes Millonario verdadero y Alvaro intentan enmendar los conflictos vitales que inquietan a ambos, a la par que el autor mismo negocia su identidad como dramaturgo.Theather as therapeutic exercise in We are all King Lear from Guillermo SchmidhuberAbstractIn We are all King Lear, written in 1979 and published in 1982, the Mexican playwright Guillermo Schmidhuber de la Mora clearly lays out an intertextuality exercise in front of William Shakespeare’s work. This study is an exploration of how Schmidhuber dramatizes the creation of hyperreality as a therapeutic process not only for certain characters of the play, but also for the audience and even for the playwright himself. To carry out this exploration, the paper applies Baudrillard’s concepts of hyperreality and simulation, as well as some affirmations from Schmidhuber himself about dramaturgy, and some of Phil Jones’ psychological concepts regarding drama therapy and its transformative effects as a theatrical exercise. Through this therapeutic process, the characters Real Millionaire and Alvaro attempt to rectify the vital conflicts that unsettle them both, while the author himself negotiates his identity as a playwright.Recibido: 05 de octubre de 2020Aceptado: 01 de febrero de 2021
Mesoscopic Modeling and Rapid Simulation of Incremental Changes in Epidemic Scenarios

In simulation-based studies and analyses of epidemics, a major challenge lies in resolving the conflict between fidelity of models and the speed of their simulation. Another related challenge arises in dealing with the large number of what–if scenarios that need to be explored. Here, we describe new computational methods that together provide an approach to dealing with both challenges. A mesoscopic modeling approach is described that strikes a middle ground between macroscopic models based on coupled differential equations and microscopic models built on fine-grained behaviors at the individual entity level. The mesoscopic approach offers the ability to incorporate complex compositions of multiple layers of dynamics even while retaining the potential for aggregate behaviors at varying levels. It also is an excellent match to the accelerator-based architectures of modern computing platforms in which graphical processing units (GPUs) can be exploited for fast simulation via the parallel execution mode of single instruction multiple thread (SIMT). The challenge of simulating a large number of scenarios is addressed via a method of sharing model state and computation across a tree of what–if scenarios that are localized, incremental changes to a large base simulation. A combination of the mesoscopic modeling approach and the incremental what–if scenario tree evaluation has been implemented in the software on modern GPUs. Synthetic simulation scenarios are presented to demonstrate the computational characteristics of our approach. Results from the experiments with large population data, including USA, UK, and India, illustrate the modeling methodology and computational performance on thousands of synthetically generated what–if scenarios. Execution of our implementation scaled to 8192 GPUs of supercomputing platforms demonstrates the ability to rapidly evaluate what–if scenarios several orders of magnitude faster than the conventional methods.
Aliquoting of isobaric labeling reagents for low concentration and single cell proteomics samples

The introduction of isobaric tagging reagents enabled more accurate, high-throughput quantitative proteomics by enabling multiple samples to be multiplexed. One drawback of these workflows is the relative expense of the proprietary isobaric reagents, which is often only second to the expense of the instruments themselves. These highly reactive chemical tags are only commercially available in relatively large aliquots compared to the typical amounts of peptides analyzed in proteomic workflows today. Excess reagents are typically disposed of following a single labeling experiment or those performed within a few days of opening a new kit. We present a simple procedure to aliquot commercial isobaric tagging reagents and demonstrate the successful and high efficiency labeling of multiple samples over a period of six months. The samples presented herein were selected as the most diverse ones labeled by prepared aliquots from a single labeling reagent kit over this period. We observe comparable labeling efficiency from 100 microgram to 100 picograms of peptide when labeling samples from both human digest standards, cancer cell lines prepared in-house and from cells directly obtained from human organ donors, despite differences in cell type, lysis, and digestion procedures. No labeling experiment of whole human proteomics samples achieved less than 92% labeling efficiency over this period. When preparing phosphoproteomic samples 6 months after the date of the aliquoting procedure, we observed a decrease in labeling efficiency to approximately 86%, indicating the end of the useful lifetime of aliquots prepared in this manner. Over this period, we have effectively reduced the reagent costs of each experiment to less than 10% of the predicted costs when following the manufacturer instructions for use and disposal. While aliquoting of reagents can be performed by hand, we provide a complete template for automatic aliquoting using an affordable liquid handling robot, including plans for 3D printing of two parts we have found useful for streamlining this procedure. Abstract Graphic O_FIG O_LINKSMALLFIG WIDTH=197 HEIGHT=200 SRC="FIGDIR/small/449560v1_ufig1.gif" ALT="Figure 1"> View larger version (51K): org.highwire.dtl.DTLVardef@18cd7eeorg.highwire.dtl.DTLVardef@1b48065org.highwire.dtl.DTLVardef@159761forg.highwire.dtl.DTLVardef@5a0896_HPS_FORMAT_FIGEXP M_FIG C_FIG
Machinery-Canopy Interactions in Tree Fruit Crops

Labor shortage has been and will continue to be one of the greatest challenges faced by agricultural industry worldwide. This issue is specifically concerning in specialty crop production, which often needs massive workforce during a short period of the growing season such as fruit harvesting and crop thinning. To address this issue, tree fruit industry is moving toward developing and adopting more mechanized and automated technologies for all kinds of field operations. However, despite all the efforts, the progress in commercially adopting mechanical or automated solutions in tree fruit crops has been slow, mainly because of the complex crop structures. Therefore, the utilization of machine-friendly tree architectures could be one of the critical ways to facilitate further advancement and adoption of automated solutions in tree fruit production. This chapter provides a unique perspective on a critical aspect of automation and robotics in agricultural fields: interaction and integration of machinery-canopy systems into developing a systems solution for agricultural robotics. The role of tree fruit crop architectures in orchard mechanization has been reviewed by comparing conventional and modern SNAP (i.e., simple, narrow, accessible, and productive) tree architectures such as a fruiting-wall system. Evidently, SNAP tree architecture minimizes the complexity of crop canopies, which can facilitate machine operations in orchards. In addition, to enable farmers to perform time-sensitive, site-specific operations precisely, various tools and technologies are essential to provide decision support based on both spatial and temporal crop variabilities. This chapter, therefore, also reviews some of the critical technologies in relation to machine-canopy interaction, such as various sensing technologies and machine/deep learning that can help us better understand interactions between machineries and crops and help us make better farming decisions in timely manner. Finally, three different case studies have been discussed in this chapter that provide specific suggestions and examples of machinery-canopy interaction and integration, thus reinforcing the understanding of the proposed concept.
Covid-19 Chest CT Scan Image Classification Using LCKSVD and Frozen Sparse Coding

The coronavirus disease 2019 (COVID-19) is a fast transmitting virus spreading throughout the world and causing a pandemic. Early detection of the disease is crucial in preventing the rapid propagation of the virus. Although Computed Tomography (CT) technology is not considered to be a reliable first-line diagnostic tool, it does have the potential to detect the disease. While several high performing deep learning networks have been proposed for the automated detection of the virus using CT images, deep networks lack the explainability, clearness, and simplicity of other machine learning methods. Sparse representation is an effective tool in image processing tasks with an efficient algorithm for implementation. In addition, the output sparse domain can be easily mapped to the original input signal domain, thus the features provide information about the signal in the original domain. This work utilizes two sparse coding algorithms, frozen dictionary learning, and label-consistent k-means singular value decomposition (LC-KSVD), to help classify Covid-19 CT lung images. A framework for image sparse coding, dictionary learning, and classifier learning is proposed and an accuracy of \(89\%\) is achieved on the cleaned CC-CCII CT lung image dataset.
Using Linear Interpolation to Implement the Change of Variables in Double Integrals

A double integral, ∬Df(x,y) dA, often can be solved by a change of variables. Typically, what makes an integral difficult to evaluate is either the form of the integrand, f, or the shape of the reg...
Results of an Opioid Hazard Awareness Training Intervention for Stone, Sand, and Gravel Miners

In the USA, miners are at higher risk for work-related disorders that could precipitate an opioid prescription, injury-related opioid prescriptions, and opioid overdose. We aimed to support prevention of these outcomes with an “opioid hazard awareness” miner safety training module. In January and February 2020, the training module was embedded within required mining safety and health training for stone, sand, and gravel miners in Massachusetts (USA). Training impact and reception were assessed with a pre- and post-training survey of trainee characteristics, training content knowledge, and attitudes. Over 800 miners were trained and over 600 responded to surveys. We found statistically significant improvements in opioid risk factor knowledge and knowledge of resources to help a coworker. Nonstigmatizing attitudes were high both at baseline and following the training. The training was perceived as relevant and useful by trainees. Improving opioid hazard awareness in high-risk worker populations has potential to reduce opioid dependence and downstream impacts including overdose death. Employer injury-prevention efforts should be reinforced while worker health and safety training enhances awareness of opioid-related harms and prevention strategies for miners and other high-risk worker populations.
ANALYTICAL METHODS IN TRANSPORTATION : MATHEMATICAL CAR-FOLLOWING THEORY OF TRAFFIC FLOW

A mathematical theory that attempts to describe the detailed manner in which one vehicle follows another in a single lane is reviewed. According to this theory, the motion of a line of cars is described by a system of differential difference equations. The parameters entering these equations have been obtained by a series of car-following experiments. Stability criteria, as well as steady state flow relationships between density, speed, and volume of traffic, are presented. In order to test the validity of this car-following model in the case of single lane traffic flow, comparisons are made with a number of experiments and observations.
Religious-Commitment Signaling and Impression Management amongst Pentecostals: Relationships to Salivary Cortisol and Alpha-Amylase

Religious-commitment signaling is thought to indicate willingness to cooperate with a religious group. It follows that a desire to signal affiliation and reap concomitant benefits would lend itself to acting in socially desirable ways. Success or failure in such areas, especially where there is conscious intent, should correspond to proximal indicators of well-being, such as psychosocial or biological stress. To test this model, we assessed religious-commitment signaling and socially desirable responding among a sample of Pentecostals with respect to salivary biomarkers of stress and arousal. Results indicate that cortisol levels on worship and non-worship days were significantly influenced by religious-commitment signaling when moderated by impression management, a conscious form of socially desirable responding. No significant influences on salivary alpha-amylase were detected. These findings are important for understanding how religious-commitment signaling mechanisms may influence stress response when moderated by socially desirable responding and the role of communal orientation to psychosocial health.
Complications associated with carbon dioxide laser surgery in gynecology.

Abstract Complications associated with the use of the carbon dioxide laser in 624 gynecologic patients are presented. Bleeding and pain were the most common side effects of this new modality. Although bleeding occurred in 63 patients, it was considered minor, i.e., requiring no treatment in 56 women. ain was rather mild and could be dealt with easily by allowing heat buildup to dissipate. Only one laser accident was observed in the entire series. Interestingly, scar formation, e.g., cervical stenosis, was essentially nonexistent. Similarly, no infections were reported. The carbon dioxide laser compares favorably to conventional treatment methods insofar as complications are concerned; however, it future complications are to be avoided, careful training in CO 2 laser technology must precede clinical use of the instrument.
An I/O-Conscious Tiling Strategy for Disk-Resident Data Sets

This paper describes a tiling technique that can be used by application programmers and optimizing compilers to obtain I/O-efficient versions of regular scientific loop nests. Due to the particular characteristics of I/O operations, a straightforward extension of the traditional tiling method to I/O-intensive programs may result in poor I/O performance. Therefore, the technique presented in this paper adapts iteration space tiling for I/O-performing loop nests to deliver high I/O performance. The generated code results in huge savings in the number of I/O calls as well as the volume of data transferred between the disk subsystem and main memory. Our experimental results on the IBM SP-2 distributed-memory message-passing multiprocessor demonstrate that the reduction in these two parameters, namely, the number of I/O calls and the transferred data volume, can lead to a marked decrease in overall execution times of I/O-intensive loop nests. In a number of loop nests extracted from several benchmarks and math libraries, we were able to improve the execution times by an average 42.5% for one data set and by an average 47.4% for another.
Composition Variations in the Solar Corona and Solar Wind

Order of magnitude variations in relative elemental abundances are observed in the solar corona and solar wind. The instruments aboard SOHO make it possible to explore these variations in detail to determine whether they arise near the solar surface or higher in the corona. A substantial enhancement of low First Ionization Potential (FIP) elements relative to high FIP elements is often seen in both the corona and the solar wind, and that must arise in the chromosphere. Several theoretical models have been put forward to account for the FIP effect, but as yet even the basic physical mechanism responsible remains an open question. Evidence for gravitational settling is also found at larger heights in quiescent streamers. The question is why the heavier elements don’t settle out completely.
Hall, electrical resistivity and magnetoresistivity measurements in MoSi3N4 and TiSi3N4 multilayered thin films

Multilayered thin films of a metal layer (Mo,Ti) alternating with an insulator layer (Si3N4) were prepared in an RF diode sputtering sustem. The modulation wavelength Λ was kept constant at 100 A, although the metal/insulator ratio was varied between .49 to .9. The dc resistivity, magnetoresistance and Hall coefficient were measured from 1.6 to 300K and for magnetic fields up to 2 T. A logarithmic increase of the resistance at low temperatures, a positive magnetoresistance, increased logarithmically for large magnetic fields, and a temperature dependent Hall coefficient indicate that electron interaction effects are the dominant mechanism for a positive TCR below Tmin.
World Bank Group Entrepreneurship and Economic Development: Presentation

The 2007 World Bank Group Entrepreneurship Survey database includes cross-country, time-series data on the number of total and newly registered businesses, collected directly from Registrar of Companies around the world.
Tension between Internal and External Modes of Stabilization in Carbocations Relevant to Terpene Biosynthesis: Modulating Minima Depth via C–H···π Interactions

Density functional theory calculations on a carbocation rearrangement relevant to the biosynthesis of the sesquiterpenoid trefolane A are described, with a focus on the viability of altering the curvature of the potential energy surface through C–H···π interactions of the sort likely to be found at the active site of a terpene synthase enzyme. These interactions are able to remove a deep minimum from a pathway to product.
Evolution on a desert island: Body size divergence between the reptiles of Nevada's Anaho Island and the mainland around Pyramid Lake

Patterns of body size evolution on islands provide compelling cases of rapid and dramatic phenotypic evolution in terrestrial vertebrates, yet debate remains over the relative roles of predation and resource availability in driving such evolution. We compared the morphology of five reptile species (four lizards, one snake) from Anaho Island, a desert island in Pyramid Lake, Nevada, and the nearby mainland, using museum and live-caught animals. We also examined head-shape allometries to make inferences about dietary shifts and recorded tail-regeneration frequencies (in lizards) to examine predation intensity. Compared with mainland samples, two phyrnosomatid lizard species are larger on Anaho (Callisaurus draconoides and Sceloporus occidentalis), whereas the largest (S. uniformis) is not different on the island. Conversely, the teiid lizard Aspidoscelis tigris is smaller in body and head size on the island, and the pitviper Crotalus oreganus is especially diminutive on the island, with males and females 25 and 15% smaller, respectively. Our results appear consistent with the hypothesis that body size is related to resource availability. The change in body size of the two smaller phrynosomatids may be due to interference competition. The reduction in body and head size in A. tigris suggests a dietary shift, and the dramatic difference in C. oreganus is likely due to a switch in diet from mammals to lizards. Future work is needed to determine whether body size differences reflect genetic evolution or environmental differences in growth rates or resource use. Regardless, Anaho Island, although remarkably young (early Holocene), appears to harbour a unique community of reptiles with distinct morphologies and possibly divergent life histories.
Self-Regulated Exposure to Light by Dark- or Light-Treated Rats

Rats allowed to expose themselves to light do so for a rather constant length of time each day. This duration of exposure depends upon both the brightness of the light used for testing and the illumination in which the rats were maintained before testing.
Meromorphic extension of the resolvent on complete spaces with asymptotically constant negative curvature

Abstract We give a detailed description of the Schwartz kernel of the resolvent of the Laplacian on a certain class of complete Riemannian manifolds with negative sectional curvature near infinity. These manifolds have compactifications as C∞ manifolds with boundary on which the metric is conformai to a C∞ metric (up to the boundary) with conformal factor ϱ−2, where ϱ is a defining function for the boundary. The modified resolvent R(ζ) = (Δ + s −2 ζ(ζ − n)) −1 defined and analytic in R (ζ > n is shown to extend to be meromorphic in the whole complex plane, when − s 2 is equal to the sectional curvature at infinity. For hyperbolic spaces obtained as quotients Γ⧹Hn + 1, where Γ is a discrete group of fractional linear transformations having a geometrically finite fundamental domain without cusps at infinity, s is constant. We then deduce from the existence of this meromorphic extension of the resolvent the existence of a similar extension for the Eisenstein series. The basic method used to produce a parametrix for the Laplacian is part of a more general construction, by G. Mendoza and the second author, but since this is not yet available the present paper has been made essentially self-contained.
Silyl rotors and amorphous silicon

Abstract Deuteron magnetic resonance is used to observe deuterated rotating silyl SiD3 groups in plasma-deposited a-Si:D films. Persistence of the rotor signal from 300 K down to less than 2 K, and comparisons with deuterated amorphous carbon, indicate that the silyl rotors do not lie within the amorphous silicon network. Comparisons of spin relaxation times also show that the rotors do not extend into deuterium-filled microvoids. The silyl rotor signals are not observed in the highest-quality a-Si:D and a-Si:D,H samples. It is concluded that SiD3 rotating groups extend into deuterium-free spaces between microcrystalline surfaces.
On the Nusselt Number in Heat Transfer Between Multiple Parallel Blood Vessels

Arrays of two or more parallel blood vessels in a tissue matrix have been studied extensively in the context of bioheat transfer. The average vessel Nusselt number (based on the difference between the mixed-mean blood temperature and the average vessel surface temperature) is a crucial parameter in such studies. Various workers have noted tht in particular cases the average Nusselt number is identical to that for fully developed flow in a single vessel in an infinite medium. In other words, the Nusselt number is unaffected by the presence of other vessels. It is proven here that this surprising result holds true for arbitrary number, size, flow direction, and velocity profile in the blood vessels, and for very general boundary conditions on the outer tissue boundary. A useful corollary is that the average wall temperature in a particular vessel may be found by evaluating the temperature fields due to the other vessels and the tissue boundaries at a single point, the center of the vessels in question.
High-throughput assay optimization and statistical interpolation of rubella-specific neutralizing antibody titers

Rubella remains a social and economic burden due to the high incidence of congenital rubella syndrome (CRS) in some countries. For this reason, an accurate and efficient high-throughput measure of antibody response to vaccination is an important tool. In order to measure rubella-specific neutralizing antibodies in a large cohort of vaccinated individuals, a high-throughput immunocolorimetric system was developed. Statistical interpolation models were applied to the resulting titers to refine quantitative estimates of neutralizing antibody titers relative to the assayed neutralizing antibody dilutions. This assay, including the statistical methods developed, can be used to assess the neutralizing humoral immune response to rubella virus and may be adaptable for assessing the response to other viral vaccines and infectious agents.
Trade deficit surprises and the ex ante volatility of foreign exchange rates

Abstract We investigate the effects of US balance of trade deficit announcements on the ex ante volatility of foreign exchange rates. Specifically, we analyze the association between currency option implied standard deviation (ISDs) and the surprise component of monthly merchandise trade deficit disclosures. Our results indicate that larger surprises, regardless of their sign, are associated with increased currency ISDs. We also find that deficit disclosures, regardless of their content, temper market uncertainty on average. Finally, we find that larger than expected deficits tend to depreciate the US dollar. (JEL F31)
Electrophysiologic effects of encainide on acutely ischemic rabbit myocardial cells.

Abstract The electrophysiologic effects of encainide were determined in normal and acutely ischemic (30 min) rabbit ventricular muscle cells. Encainide (10−6, 5 × 10−5 M) had no effect on resting potential (RP); 10−6 encainide reduced overshoot and action potential (AP) amplitude of cells in normal left ventricles and cells in normal areas of ischemic ventricles. Encainide, 5 × 10−6 M and 10−5M, depressed Vmax and prolonged AP duration of normalcells. Surviving cells within ischemic areas displayed AP with reduced RP, overshoot, AP amplitude, Vmax and shorterned AP duration. All encainide concentrations reduced overshoot, AP amplitude and Vmax of depressed AP. Encainide's lengthening of AP duration was greater in cells within ischemic areas than in surrounding normal cells. Encainide (10−6 M) prolonged effective refractory period and often AP in ischematic cells. Encanides also caused depression in membrane responsiveness. Encainide's differential effect upon AP may significantly contribute to its antiarrhythmic activity in ischemic heart disease.
Ornithine decarboxylase activity in rabbit retina following treatment with alpha-difluoromethylornithine

The rabbit retina has been utilized as a model for the study of abnormal cellular proliferation on the retinal surface and into the vitreous, a process commonly initiated by trauma and generally leading to retinal detachment. This study characterizes the ability of alpha-difluoromethylornithine (alpha-DFMO), a suicide inactivator of L-ornithine decarboxylase (EC 4.1.1.17) to inactivate normal retinal ornithine decarboxylase (ODC) activity in the crude supernatant fraction after incubation with different concentrations of alpha-DFMO and at various times after intraocular administration. Partial inactivation of ODC activity occurred following preincubation of crude retinal supernatant fraction with 10(-5) M alpha-DFMO (N = 3; 34 +/- 6.9% of control), whereas preincubation with 10(-8) M alpha-DFMO did not alter ODC activity significantly (N = 3; 94 +/- 2% of control). Different concentrations of alpha-DFMO administered intraocularly inactivated retinal ODC activity to varying degrees with different rates of recovery. No gross toxicity occurred with ocular tissues following intravitreal administration of alpha-DFMO as determined by electrophysiologic measurements, by indirect examination of the retina, and by measurement of intraocular pressure. These results suggest that alpha-DFMO may be a useful tool in which to define the physiologic role of ODC and polyamines in intraocular cellular proliferative diseases.
Head circumference and incident Alzheimer's disease: modification by apolipoprotein E.

Background: The clinical expression of AD likely occurs when the accumulation of degeneration in specific brain regions leads to the descent below a critical threshold of “brain reserve” beyond which normal cognitive function cannot be maintained. The association between head circumference (HC), a measure of brain reserve, and the incidence of probable AD was examined in a large nondemented cohort that has been followed since 1992 and its modification by APOE e4 genotype. Methods: Fifty-nine incident cases of probable AD were identified from 1,869 initially nondemented individuals seen at the baseline examination (1992 to 1994) and followed for a mean of 3.8 years. Variables measured at baseline included age, education, gender, HC, height, weight, and score on the National Adult Reading Test–Revised. APOE was genotyped at the time of the first biennial examination (1994 to 1996) and was available for 1,111 individuals in the cohort. Cox proportional hazard regression was performed to estimate hazard ratios (HR) for probable AD for HC and other covariates. Results: Incident cases were significantly older, less educated, shorter, and lighter, had lower estimated verbal IQ scores, and were more likely to have at least one APOE e4 allele than unaffected individuals. The HR associated with the lowest tertile of HC ( Conclusions: Smaller HC, in the presence of the APOE e4 allele, hastens the age at onset of AD. These results support the brain reserve hypothesis and its importance in precipitating the clinical expression of AD among genetically predisposed individuals.
Fire dynamics simulations of a one-meter diameter methane fire

A one-meter diameter-methane fire was simulated to validate a fire dynamics simulation code for large-scale fires. A uniform grid size of 2.5 cm in the entire computational domain is used. Therefore, only large-scale motions of the fire are resolved. The subgrid-scale heat release is modeled using a mixture-fraction-based combustion model. The radiative heat loss is computed using two methods: a fixed radiative fraction method and a finite volume method. The computed puffing cycle frequency is affected very weakly by the radiation heat loss. The vertical velocity magnitudes without considering radiation heat loss are about 15% higher, particularly at locations farther away from the burner exit. Good agreement between the predictions and the recent data from Tieszen and co-workers at Sandia National Laboratory confirms the feasibility of fire dynamics simulations of relatively large fires.
Second generation transition state analogue inhibitors of human 5′-methylthioadenosine phosphorylase

The polyamine biosynthetic pathway is a therapeutic target for proliferative diseases because cellular proliferation requires elevated levels of polyamines. A byproduct of the synthesis of spermidine and spermine is 5‘-methylthioadenosine (MTA). In humans MTA is processed by 5‘-methylthioadenosine phosphorylase (MTAP) so that significant amounts of MTA do not accumulate. Products of the MTAP reaction (adenine and 5-methylthio-α-d-ribose-1-phosphate) are recycled to S-adenosylmethionine, the precursor for polyamine synthesis. Potent inhibitors of MTAP might allow the build-up of sufficient levels of MTA to generate feedback inhibition of polyamine biosynthesis and/or reduce S-adenosylmethionine levels. We recently reported the design and synthesis of a family of potent transition state analogue inhibitors of MTAP. We now report the synthesis of a second generation of stable transition state analogues with increased distance between the ribooxocarbenium ion and purine mimics. These compounds are potent inhi...
MECHANISMS OF STEROID HORMONE ACTION

The molecular biology of steroid hormone action is reviewed. Topics discussed include the chick oviduct system as a model for exploring the effects of steroid hormones the nature of steroid hormone receptors the nuclear uptake of receptor-hormone complexes nuclear retention of the receptor-hormone complex the initiation of RNA synthesis by steroid hormones the synthesis modification and export of messenger RNA and translation of mRNA. It has been possible to induce ovalbumin mRNA synthesis in vitro by combining purified steroid hormone-receptor complexes with RNA polymerase interphase chromosomes and necessary substrates. A similar effect is observed in vivo with progesterone treatment. It is suggested that steroid hormone receptors act directly on the cells genetic apparatus to promote gene expression.
Studies on choline transport enhancement into fibroblasts from normals and Alzheimer's donors.

Human dental fibroblasts transport choline actively. This transport is inhibitable by hemicholinium-3. In this paper, choline transport into fibroblasts of normal donors (four cell lines) and into those of Alzheimer victims (four cell lines, age and sex matched to the normals) is accelerated by methylated xanthines, nicotine, and dexamethasone. At a caffeine concentration of 10 μM the stimulation of choline transport into normal cells averages 128% and into Alzheimer donor cells, 45%. 1 μM Dexamethasone stimulates choline influx by 86% in normal cells and 36% in Alzheimer cells. Nicotine enhances choline transport by 35% in normal cells and by 16% in Alzheimer cells. The implication is that if Alzheimer's disease is a cholinergic disorder, it may be amenable to transport-directed chemotherapies.
Restriction endonuclease banding of rainbow trout chromosomes

Rainbow trout chromosomes were treated with nine restriction endonucleases, stained with Giemsa, and examined for banding patterns. The enzymes AluI, MboI, HaeIII, HinfI (recognizing four base sequences), and PvuII (recognizing a six base sequence) revealed banding patterns similar to the C-bands produced by treatment with barium hydroxide. The PvuII recognition sequence contains an internal sequence of 4 bp identical to the recognition sequence of AluI. Both enzymes produced centromeric and telomeric banding patterns but the interstitial regions stained less intensely after AluI treatment. After digestion with AluI, silver grains were distributed on chromosomes labeled with [3H]thymidine in a pattern like that seen after AluI-digested chromosomes are stained with Giemsa. Similarly, acridine orange (a dye specific for DNA) stained chromosomes digested with AluI or PvuII in patterns resembling those produced with Giemsa stain. These results support the theory that restriction endonucleases produce bands by cutting the DNA at specific base pairs and the subsequent removal of the fragments results in diminished staining by Giemsa. This technique is simple, reproducible, and in rainbow trout produces a more distinct pattern than that obtained with conventional C-banding methods.
SURGERY FOR ADOLESCENT AND PRADER-WILLI |[lpar]|P-W|[rpar]| OBESITY

We have done gastric bypass surgery on 10 morbidly obese adolescents, three of whom also had P-W syndrome. Surgical criteria included a weight > 200% of ideal body weight for height (IBW), significant morbidity from the disease such as hypertension, diabetes or Pickwickian syndrome, and failure of medical therapy. No acute surgical morbidity occurred. One patient has been lost to followup. Two P-W patients have plateaued after losing 49.7 kg and 25.9 kg. One P-W patient has regained the 20 kg he lost after surgery. The mean degree of obesity in the P-W patients decreased from 261% to 206% IBW, whereas mean weights for the non P-W group have decreased from 221% to 157% IBW. Mean weight losses in the non P-W group = 36.5 kg and are continuing. Lean body mass, studied by H218O, decreased by 5-10% in the first three post operative months but repleted thereafter. In all non P-W cases, plateaus in weight occurred 6-12 months post-operatively, but, in contrast to pre-operative circumstances, patients were able to alter their diets and resume weight loss. Staple line separation occurred by one year in three patients, and required reoperation in one. These results indicate that gastric by-pass surgery may be of considerable benefit to carefully selected obese adolescent patients.
Environmental injustice in America and its politics of scale

Abstract Environmental burdens, such as proximity to hazardous sites, tend to be inequitably borne by poor Americans in general, and by Americans of color in particular. So argues a loose coalition of grassroots organizations and public-interest groups known as the Environmental Justice (EJ) movement. Prompted by that movement, the national government and some state legislatures have established policies to address future inequity. Those policies assume that the scope of environmental injustice spans the country, with many hazardous facilities dotting the landscape in communities of color and/or of the poor. However, various industries and also some social scientists call into question the argument that inequities occur on a national, or even state-wide, scale. Their counter-arguments typically espouse a market-based explanation that localizes the problem: any inequitable risks result from the impersonal forces of the marketplace functioning within individual communities. The politics of EJ pivot around defining the scales of inequity and its resolution. This paper examines the debates over environmental justice in terms of the tension between the scale(s) of the problem itself and the scale(s) at which the problem is to be resolved (or at least ameliorated) via government policy. The paper also sketches several theoretical and political implications of the debates. Theoretically speaking, market-based explanations tend to privilege the local scale, thereby ignoring vital factors that help us to understand environmental inequity as a phenomenon operating at a multitude of scales from the local to the national and international scales. Politically speaking, if the inequities were particular to discrete locales, then extensive governmental involvement would be unnecessary.
Competitiveness of Agrostis interspecific hybrids in turfgrass swards.

Transgenic herbicide-resistant cultivars of creeping bentgrass (Agrostis stolonifera L.) have been developed and are being considered for commercial release. Concerns regarding transgenic species include potential for outcrossing of the crop, which may produce novel genotypes with increased weediness. Persistence and multiyear growth of interspecific hybrids between creeping bentgrass and velvet bentgrass (A. canina L.), colonial bentgrass (A. capillaris L.), dryland bentgrass (A. castellana Boiss. and Reut.), and redtop bentgrass (A. gigantea Roth) and the backcross progeny of the hybrids were compared with the parental species in field experiments. The plants were evaluated over 2 yr in residential Kentucky bluegrass (Poa pratensis L.) and a low maintenance roadside turf of mixed species. With the exception of redtop bentgrass by creeping bentgrass interspecific hybrids, all interspecific hybrids between creeping bentgrass and colonial, dryland, and velvet bentgrasses were equally or less competitive relative to their parental species. Backcross progeny of interspecific hybrids, including those of redtop bentgrass by creeping bentgrass hybrids, were equally or less competitive than parental species. Bentgrasses that were highly competitive in residential turf were also competitive under roadside maintenance, suggesting bentgrasses have weediness potential regardless of management intensity.