cssi/SciSciGPT-SciSciNet huggingface dataset:
Bosonized Wakimoto Construction in the Principal Gradation

It is well known that the bosonized version of the Wakimoto construction allows the explicit realization of any affine algebra $$\widehat g$$ , with arbitrary level k in the homogeneous gradation, in terms of dim $$\left( g \right)$$ free bosonic fields.However, its extension in the principal gradation has been achieved only in the simplest case k=1. In this Letter we show, in the case of the simplest affine algebra $$\widehat{{\text{sl(2)}}}$$ ,that the bosonized Wakimoto realization can be extended to the principal gradation only when k is equal to the critical level, i.e., –2.In this case, this construction can be achieved in terms ofarbitrary number (larger than 1) of free bosonic fields.
Network Dynamics in Cardiac Electrophysiology

In a network perspective, the heart is a network of cells that are composed of subnetworks of genes, proteins, metabolites, and organelles. In this chapter, we provide an overview of the networks in the heart and a current understanding of the network dynamics in the context of cardiac electrophysiology. We first review current knowledge of the genetic, signaling, and metabolic networks in the heart and their links to arrhythmias. We then review the emergent properties from the mitochondrial and calcium release unit networks, the cellular dynamics arising from integrated subnetworks, and the electrical dynamics arising from the cellular networks to manifest as normal rhythms and arrhythmias. Finally, we discuss future challenges and how systems biology approaches can overcome these challenges to uncover the mechanisms of normal heart rhythms and arrhythmias.
Induction and regulation of contact hypersensitivity in Syrian hamsters.

Syrian hamsters were introduced into experimental biology more than 50 years ago when it was found that they were particularly useful for the study of certain parasitic diseases (1). Within a relatively short period of time, their usefulness as experimental subjects was extended into several seemingly unrelated fields. They came to be used extensively for the study of experimental neoplasms (2), virus infections (3), and transplantation immunology (4). After the first 20 years of experience, the hamster came to be regarded as a relatively unique experimental subject because of certain putative aberrations: 1. hamsters reject skin allografts poorly or not at all (4); 2. hamsters are unusually susceptible to induction of tumors with a variety of oncogenic agents (2); 3. hamsters are highly susceptible to infection with viruses from many different species (3). Over the last two decades immunologists have learned that rejection of allografts, resistance to viral infection, and resistance to tumor induction are properties of the immune response that are presided over by the thymus and its cellular progeny. Because of the paramount role played by the thymus-dependent system in these various immune reactivities, it seemed reasonable to question the nature and extent of thymic function in the Syrian hamster. Surprisingly little is known about the T-cell system in this species. It was discovered more than 15 years ago that the ontogenetic maturation of the thymus as studied histologically is delayed (5). Evidence in support of this idea includes the facts that: 1. induction of neonatal transplantation tolerance can be achieved in hamsters up to a week following birth (4); 2. seeding of peripheral lymphoid organs with lymphocytes labeled intrathymically is delayed following birth compared to mice and rats (6); and 3. thymectomy performed as late as four weeks after birth results in a progressive wasting syndrome in hamsters resembling that following neonatal thymectomy in mice and rats (5,7). More recently, it has been found that hamsters fail to regulate certain alloimmune reactions thought to be governed by functional subsets of T lymphocytes in mice and other species. For example, hamsters fail to suppress graft-versus-host reactions in vivo following specific alloimmunization (8), and they do not develop suppressor cells in mixed lymphocyte cultures designed to delineate a putative allogeneic T-cell suppressor (9). In response to alloimmunization in vivo or in vitro, hamster lymphoid cells fail to assume significant cytotoxic activity as measured in vitro (10). Moreover, there is evidence that hamsters fail to develop cytotoxic T cells in response to acute virus infection (11).
Weak-Beam Microscopy

Transmission electron microscopy of thin, crystalline samples has been profitably performed for the past two decades. A significant fraction of the transmission electron microscopy performed has focused on the observation of strain-related defects, such as point defect clusters, dislocations, etc. associated with the microstructure of the crystalline thin sample. Even though these strain-related defects are often considered with reference to an angstrom-unit-sized displacement, for instance a Burgers vector in the case of a dislocation, the transmission electron microscope image of such a defect, observed in bright-field or strong-beam dark-field microscope, can be hundreds of angstroms in size. It is well known that a dislocation has a bright-field image whose peak width at half minimum is between ξg/3 and ξg/5 where ξg is the extinc-tion distance, often many hundreds of angstroms in size (HIRSCH et al., 1965).
Synthesis of Azulenone Skeletons by Reaction of 2-Phenyl-2-acylketenes [RCO(Ph)CCO] with Alkynyl Ethers: Mechanistic Aspects and Further Transformations

A method is described for a mild and efficient synthesis of azulenone skeletons via the addition reactions of 2-phenyl-2-acylketenes with 1-alkynyl ethers. A mechanism is presented to account for both azulenone formation as well as the solvent and substrate dependency of a competitive pyrone formation. The azulenone rings have been subsequently transformed into both substituted azulenes or hydroazulenes by derivatization and/or decarboxylation of an angular carboxyl substituent or by hydrogenation.
COLLECTIVE CHOICE RULES AND PARETO COMPARISONS

This chapter discusses the collective choice rules and Pareto comparisons. It is assumed that X is the set of social states. The preference relation of the i th individual is R i , and there be n such persons, i = 1, …, n . It is supposed that R refer to the social preference relation. It is assumed that each individual has an ordering, for each i, R. is reflexive, transitive, and complete. For the relation of social preference R, no such assumption is easy to make, and indeed it is part of exercise to see whether R will have these characteristics or not. A collective choice rule is a functional relation f such that for any set of n individual orderings R l , …, R n (one ordering for each individual), one and only one social preference relation R is determined, R = f ( R 1 , …, R n ).
The Effects of Energy Drink Consumption on Cognitive and Physical Performance in Elite League of Legends Players

To examine the cognitive and physical changes associated with consuming an energy drink concurrent to video gaming, we examined a convenience sample of nine elite League of Legends (LoL) e-sport players (21 ± 2 y, BMI 25.6 ± 3.4 kg/m2) consuming an energy drink (ReloadTM) or placebo (Placebo) in a randomized, double-blind, placebo-controlled cross-over trial. Participants completed the same test battery prior to treatment consumption and after playing each of three competitive LoL games. Primary outcomes included measures of attention (Erikson Flanker Test), reaction time (Go/No-Go test) and working memory (n-back test). Secondary outcomes examined fatigue (hand grip strength and finger tap speed). Statistical analysis was performed by repeated-measures analysis of variance (RM-ANOVA) and reported as the mean (standard deviation [SD]) or mean change (95% confidence interval [CI]). Participants reported sleeping 8.1 (1.2) h/night, playing LoL 10.3 (2.1) h/d, playing other video games 1.8 (2.8) h/d, and exercising 4.2 (1.7) times per week. Overall, we observed no significant time, group, or group-by-time interactions for any measured performance index with the exception of a significant improvement for the n-back test, where the Reload group demonstrated a significant within-group improvement: Reload [−171 ms (95% CI, −327.91, −14.09), p < 0.004], Placebo [−92 ms (95% CI, −213.63, 29.63)]. However, no between-group differences were noted (38.50 ms, 95% CI, −141.89, 64.89, p = 0.803). Our findings suggest that elite eSport athletes do not demonstrate a mental or physical improvement in performance relative to the treatment supplement or indices measured in this study.
Estimated Life Tables for the United States, 1850–1910

This article presents a series of abridged life tables derived from earlier work by the author and Samuel H. Preston.... These tables provide a superior picture of the mortality situation in the United States from 1850 to 1910. In addition these tables can be of assistance in the following ways: estimating own-children fertility and census-survival migration calculating probabilities for finding certain family structures in the census and making estimates of working life. (EXCERPT)
Estimating causal effects of class size in secondary education: evidence from TIMSS

ABSTRACTThe effectiveness of class size reduction on student performance has been of great research interest and policy debate worldwide. Nevertheless, the evidence has been largely inconclusive pa...
Tissue Dielectric Constant Measures in Women With and Without Clinical Trunk Lymphedema Following Breast Cancer Surgery: A 78-Week Longitudinal Study.

Objective Following breast cancer surgery with lymph node removal, women are at risk of developing lymphedema in the upper extremity or trunk. Currently, trunk lymphedema diagnosis relies on a clinical assessment because no quantifiable standard method exists. Tissue dielectric constant (TDC) values are quantifiable measures of localized skin tissue water and may be able to detect trunk lymphedema. The goal of this study was to (1) compare parameters derived from TDC measurements with those derived from clinically accepted criteria for trunk lymphedema in women following breast cancer surgery and (2) explore the potential utility of TDC to detect trunk lymphedema early in its progression. Methods This prospective longitudinal study, a secondary analysis from a larger study, observed women with and without clinically determined truncal lymphedema following breast cancer surgery. TDC was measured on the lateral trunk wall at post-surgery weeks 2, 4, 12, and 78 in women who had surgical breast cancer treatment with lymph node removal. Clinical assessment for trunk lymphedema was determined at 78 weeks by a lymphedema expert. Comparison of TDC measurements in women with and without clinical trunk lymphedema was analyzed. Results Clinical assessment identified trunk lymphedema in 15 out of 32 women at 78 weeks. These women had TDC ratios statistically higher than women without truncal lymphedema. Conclusion The overall findings indicate that TDC has the ability to quantify trunk lymphedema and might be valuable in early detection. Impact TDC may be a beneficial tool in the early detection of breast cancer related trunk lymphedema which could trigger intervention.
Designing Intrinsically Microporous Polymer (PIM-1) Microfibers with Tunable Morphology and Porosity via Controlling Solvent/Nonsolvent/Polymer Interactions

In this study, we present the fabrication of fibers with tunable morphology and porosity from an intrinsically microporous polymer, PIM-1, using a simple one-step electrospinning technique. The met...
Detonation Structure in Ethylene/Air-Based Non-Premixed Rotating Detonation Engine

Rotating detonation engines (RDEs) are gaining significant interest as a practical approach to increasing the operating efficiency of propulsion systems through pressure gain combustion. To use RDE...
Laparoscopic Roux-en-Y Gastric Bypass

Surgical management of weight loss has gained popularity over the last years. The majority of gastric bypass procedures are done laparoscopically. Knowledge of the surgical anatomy and the steps of the procedure are of paramount importance in order to diagnose potential life threatening complications in these patients. This chapter discussed a laparoscopic roux en y gastric bypass.
Demographic differences on health personality in a United States older adult sample

Abstract The purpose of this study was to explore demographic differences in health personality. Data consisted of 3907 participants, 65 years and older. Multivariate analysis of variance with post hoc testing revealed women had higher health neuroticism scores than men, but men had higher health extraversion scores than women. Those married reported higher health agreeableness than those not married and young-old participants had higher health extraversion and health openness compared to other age groups. Regional differences included Midwest participants reporting higher health openness but lower health conscientiousness scores when compared to participants from other regions. There were also significant region by ethnicity interactions. The results are helpful for healthcare providers who can tailor intervention approaches to specific populations.
Stealth Recapitalization and Bank Risk Taking: Evidence from TLTROs

I study the transmission of unconventional monetary policy through an increase in bank net worth. I examine the ECB’s Targeted Long Term Refinancing Operations (TLTROs), which provided interest rate subsidized loans to banks. First, I measure the rate subsidy and document that it results in equity gains for banks facing high borrowing costs in the private market, especially low capitalized banks. Second, using loan-level data from a sample of thirty-three European banks, I show that weakly capitalized banks receiving TLTRO funding subsequently decreased their risky lending. The effect spills-over to asset classes not targeted by TLTROs and is largest for banks receiving higher interest rate subsidies. In contrast to previous evidence, these results support that subsidized funding can boost bank net worth and offset risk-shifting incentives of banks, resulting in improved ex-post stability of the financial sector. The differences in results can be potentially attributed to differences in asset-side and liability-side recapitalizations as well as the different frictions (limited liability/regulatory scrutiny) faced by weakly capitalized banks in each setting.
Item and scale properties of the Oral Health Literacy Adults Questionnaire assessed by item response theory.

Objectives a) To evaluate the item and scale properties of the Oral Health Literacy Adults Questionnaire (OHL-AQ) in an adult general population. b) To determine precision or accuracy of the respondents' estimated scores along the Oral Health Literacy (OHL) spectrum using item response theory (IRT) modeling. Methods Survey data were collected from a convenience sample of 405 adult attendees of the 2014 Minnesota State Fair. We used the two-parameter logistic (2PL) model for the item response theory (IRT) analyses of OHL-AQ data and calibrated items to estimate model-based item difficulty and discrimination parameters. Item and scale properties were also assessed by plotting and interpreting item characteristic curves (ICCs), test characteristic curve (TCC), and test information function (TIF). Results Based on interpretation of model coefficients, statistical testing, and model fit criteria, we deemed the 2PL model superior and selected this model to examine item and scale properties. Scale reliability was shown to be good through the test information function (TIF). TIF from our analysis showed that higher levels of OHL were measured less precisely than lower levels of OHL. Conclusion We demonstrated OHL-AQ as a whole has promising psychometric properties. However, for equiprecise measurement across the scale range, the scale needs more items for measuring higher levels of OHL.
Like, Comment, or Share? Exploring the Effects of Local Television News Facebook Posts on News Engagement

This study examines the effects of local television stations’ Facebook posts on news engagement. By scraping 4,151 Facebook posts from a local television station’s Facebook page, this investigation...
The Family Context of Toddler Sleep: Routines, Sleep Environment, and Emotional Security Induction in the Hour before Bedtime

Family processes during the pre-bedtime period likely have a crucial influence on toddler sleep, but relatively little previous research has focused on family process in this context. The current s...
What makes space activities commercial

Abstract Between the 1950s and 1980s, U.S. space sector activities were government-driven, government-sponsored, government-managed, and assisted by the industry-sector. Awareness of non-governmental space activities originated in the 1980s and gained prominence in the early 2000s with the founding of well-funded private companies. This paper takes an organizational evolution perspective to refine what is meant by “commercial” space markets and activities and compares the results to previous discussions offered by space community authors. From an organization theory perspective, the three primary forces of the evolution change model (variation, selection, and retention) provide a framework for renewed commercial space activity discussions. Together, the strength of these three forces can indicate how “commercial” a market is. Two case examples are presented to illustrate application of this framework: the U.S. space race era activities during the 1960s, and the current space tourism market. Despite competitions for various contracts awarded to industry-sector firms, the Apollo program was clearly government-driven, and was not “commercial” to any significant extent. The current space tourism market is clearly considered “commercial,” but with qualifications. Conclusions from this review include the appropriate levels of analysis to discuss space market characteristics, a comparative analysis of the “commercial” activities of the U.S. space race era and the current space tourism, the inference of proxies for estimating the strength of the three evolution model forces, and a caution about the accuracy of “commercial” market forecasts.
Alternative Education and Wholehearted Teaching: Revolutionizing How We Learn and Love

Following a circuitous and diverse journey through a nonnormative education that spanned the gamut of our education system—from being tracked into advanced and Gifted and Talented courses, to being...
Optimizing Breast Reconstruction through Integration of Plastic Surgery and Radiation Oncology.

Post-mastectomy radiation therapy (PMRT) is an important adjunct to improve oncologic outcomes and survival in select breast cancer patients at increased risk for local recurrence. As recommendations for PMRT broaden, an increasing number of patients will have it included as part of their breast cancer treatment plan. Methods This overview of the literature strives to broaden the exposure of the plastic surgeon to PMRT and describe the indications, guidelines, and considerations relevant to reconstructive surgery. The primary targets and dosing considerations will also be reviewed. Finally, the short- and long-term toxicities are outlined with the goal of providing the plastic surgeon insights with which to recognize certain toxicities in the clinic during follow up and to develop the fluency to be able to talk to patients about the potential for certain toxicities. Results Generally, PMRT is safe and well tolerated. Considerations in breast reconstruction should be made on a patient-by-patient basis. Plastic surgeon familiarity with PMRT, its indications, and complications will amplify the surgeon's ability to optimize outcomes. Conclusions As more women undergo breast reconstruction, an increasing number of patients will have PMRT as part of their breast cancer treatment plan. By understanding the basic principles of PMRT, plastic surgeons can engage patients in conversations of shared decision-making and maximize outcomes.
Adherence to public institutions that foster cooperation.

Humans typically consider altruism a moral good and condition their social behavior on the moral reputations of others. Indirect reciprocity explains how social norms and reputations support cooperation: individuals cooperate with others who are considered good. Indirect reciprocity works when an institution monitors and publicly broadcasts moral reputations. Here we develop a theory of adherence to public monitoring in societies where individuals are, at first, independently responsible for evaluating the reputations of their peers. Using a mathematical model, we show that adherence to an institution of moral assessment can evolve and promote cooperation under four different social norms, including norms that previous studies found to perform poorly. We determine how an institution’s size and its degree of tolerance towards anti-social behavior affect the rate of cooperation. Public monitoring serves to eliminate disagreements about reputations, which increases cooperation and payoffs, so that adherence evolves by social contagion and remains robust against displacement. Here, the authors examine how altruism can emerge as people come to trust a public institution of moral assessment, which broadcasts whether individuals have good or bad reputations for reciprocity.
On an inverse problem for a fractional semilinear elliptic equation involving a magnetic potential

Abstract We study a class of fractional semilinear elliptic equations and formulate the corresponding Calderon problem. We determine the nonlinearity from the exterior partial measurements of the Dirichlet-to-Neumann map by using first order linearization and the Runge approximation property.
Ketogenic Diet Therapy for Epilepsy Associated With Aicardi Syndrome.

Introduction:Aicardi syndrome is a rare neurodevelopmental disorder associated with epilepsy in females. Ketogenic diet therapy represents a possible nonpharmacologic treatment in Aicardi syndrome ...
Dismantling Studies of Psychotherapy

A dismantling design is one type of therapy outcome study. This design investigates therapies that have multiple components with the goal of trying to identify those features of the therapy that are either the active mechanisms of change or identify the degree to which specific components add to the magnitude of change attributable to other components. Thus, dismantling studies serially decompose a multicomponent therapy. One method of conducting these designs is to compare discrete components of the therapy with the total combined treatment. Depending on the number of identifiable components, individual components may be studied in isolation or in combination with other components of the intervention. They are in contrast to additive designs that attempt to build interventions starting with one component and subsequently adding additional components with the goal of identifying the contribution of each new component. Keywords: additive designs; dismantling designs; methodology; outcome research; psychotherapy outcome research; research; therapy; therapy optimization
Experimental Evaluation of OpenVZ from a Testbed Deployment Perspective

A scalable approach to building large scale experimentation testbeds involves multiplexing the system resources for better utilization. Virtualization provides a convenient means of sharing testbed resources among experimenters. The degree of programmability and isolation achieved with such a setup is largely dependent on the type of technology used for virtualization. We consider OpenVZ and User Mode Linux (UML) for virtualization of the ORBIT wireless testbed and evaluate their relative merit. Our results show that OpenVZ, an operating system level virtualization mechanism significantly outperforms UML in terms of system overheads and performance isolation. We discuss both qualitative and quantitative performance features which could serve as guidelines for selection of a virtualization scheme for similar testbeds.
Organizations, Environmental Statistics

Environmental statistics is by its very nature an international endeavor. Every nation in the world must address environmental issues ranging from pollution assessment to biodiversity, global warming to ecosystem monitoring. To solve these issues, any one nation must cooperate with one or more other nations. It is therefore not surprising that many international organizations have formed to work on solutions to environmental statistical issues. This entry provides brief summaries of the major environmental statistical organizations. The list is not intended to be all-inclusive, rather to provide a short introduction to some of the primary sources for professional information on environmental statistics.
Relocation of shallow earthquakes in southern Alaska using Joint Hypocenter Determination method

A subset of 2660 shallow earthquakes (0–50 km) that occurred from 1988 to 1996 in south central Alaska between 155°W and 145°W and 59°N and 63°N was relocated using the joint hypocenter determination (JHD) method. Both P- and S-wave observations recorded by the regional seismic network were used. Events were relocated in twenty different groups based on their geographic location and depth using two velocity models. As a result of the relocation, the majority of the hypocenters shifted downward, while the epicenter locations did not change significantly. The distribution of the shallow subduction zone earthquakes indicates the existence of two seismically independent blocks, with one block occupying the northeastern part and the other occupying the central and western parts of the study area. The boundary between the blocks is marked by a 15 to 20 km wide seismicity gap to the southeast of 149.5°W and 62°N. The analysis of the fault plane solutions for shallow subduction zone earthquakes shows that an overwhelming majority of the solutions represent normal, oblique-normal or strike-slip faulting with predominant WNW-ESE orientation of T-axes. This indicates a down-dip extensional regime for the subducting slab at shallow depths. Very few earthquakes yielded fault plane solutions consistent with thrusting on a contact zone between the overriding and subducting plates. This result may be an indication that currently either the strain energy is not released at the contact zone or it is associated with aseismic motion.
Discussion of Rundel “Fire of Eros” Paper

Reviewing Rundel’s spectrum model of differentiation–dedifferentiation and its role in sexuality and oceanic experiences, Vaughan discusses another way of conceptualizing Rundel’s clinical material in terms that do not involve a binary with poles. Using Lakoff and Johnson’s work on the body in the mind and on metaphor as arising from properties of the physical and bodily world. In addition, Vaughan notes, the friction produced by the literal and figurative rubbing up against bodies and boundaries in sexuality is partly responsible for the Fire of Eros. In transcendent experiences of sexuality we are at once both most fully ourselves and most interdigitated with and connected to others.
Restriction enzymes: properties and use.

Publisher Summary This chapter lists all commercially available enzymes, to describe their general properties, the basic procedures for their use, and ways of troubleshooting problems encountered in their use. Although the number of enzymes being discussed is large, a few simple rules apply to virtually all the enzymes. The ability of these enzymes that is to cut DNA at a specific sequence of bases has greatly stimulated the growth of recombinant DNA technology. The popularity of these enzymes is, in part, due to their wide commercial availability and the simplicity of their use. This chapter describes that most enzymes can be used successfully without the help of premade kits, colorful charts, complex buffers, or specialized equipment. A restriction digest of DNA will result in degradation. In nearly every case, contaminants in the DNA are the culprits. Cells, including E. coli contain a number of nonspecific nucleases. If these are not eliminated during the preparation of DNA, degradation of DNA will result during the digest. This can be tested by incubating the DNA in the buffer at the appropriate temperature in the absence of any added RE. Phenol extraction followed by removal of the phenol will alleviate the nuclease contamination.
Ultra-low dose CT in the assessment of diffuse lung disease: Comparison with conventional images

Introduction: There is limited information on the effects of significant radiation dose reduction on the diagnostic quality of CT examinations in patients with diffuse lung disease. Since many such patients undergo multiple studies over time, such efforts are important. Aims: We compared very low-dose to conventional CT images in patients with diffuse lung disease using different reconstruction techniques to determine the visibility of relevant findings. Methods: We evaluated 6 patients with a variety of diffuse lung disorders. All patients underwent CT first with 100 kVp and 80 mAs and then again with 80 kVp and 40 mAs. Standard filtered back projection (FBP) and a new model based iterative reconstruction (MBIR) technique were used to reconstruct the raw data into images of 1.25 mm collimation. Three observers compared the images with regard to the conspicuity of relvent findings of fibrosis and interstitial disease. Results: Images reconstructed with MBIR had less noise than the FBP images at all doses, but the low dose images were not of diagnostic quality. In particular, the FBP images were severely degraded by noise, while the low dose MBIR technique caused this noise to appear as ground glass attenuation. Subtle findings of fibrosis were obscured at low dose. CT dose index (CTDI) was 3.61 mGy for conventional and 0.97 mGy for the low dose examinations. Conclusions: MBIR smooths image noise, but there is a dose below which diagnostic quality suffers. While many relevant findings can be depicted at low dose, it appears that imaging below a CTDI of 1 mGy results in reduced diagnostic quality in patients with diffuse lung disease that cannot be improved with MBIR.
Adaptive live video streaming by priority drop

In this paper we explore the use of priority progress streaming (PPS) for video surveillance applications. PPS is an adaptive streaming technique for the delivery of continuous media over variable bit-rate channels. It is based on the simple idea of reordering media components within a time window into priority order before transmission. The main concern when using PPS for live video streaming is the time delay introduced by reordering. In this paper we describe how PPS can be extended to support live streaming and show that the delay inherent in the approach can be tuned to satisfy a wide range of latency constraints while supporting fine-grain adaptation.
Determination of organic nitro compounds using HPLC-UV-PAED

High-performance liquid chromatography with ultra violet and photo-assisted electrochemical detection (HPLC-UV-PAED) has been applied to the sensitive and selective determination of organic nitro compounds. The system was first developed for the determination of nitro explosives, and PAED has shown superior sensitivity over UV detection for these compounds (i.e., <1 part-per-trillion for HMX). The system also shows enhanced selectivity over the traditional UV method in that two detectors can be used for improved analyte identification. Also, having two detectors permits chemometric resolution of overlapping peaks, and this is not addressed in the UV method. Because this method is applicable to a wide range of nitro explosives, it was predicted that PAED would show the same sensitivity and selectivity toward other types of nitro compounds. Since its development, the system's use has been expanded to include the determination of nitro-containing pharmaceuticals and glycosylated nitro compounds in biological matrices. Model compounds were chosen, specifically nitroglycerin and related compounds and nitrophenyl-glucoside, to represent these classes. PAED showed superior detection limits over low wavelength UV detection for nitroglycerin (PAED = 0.3ppb, UV at 220nm = 48ppb), demonstrating PAED"s applicability to determining nitro-pharmaceuticals. Conversely, UV detection at 220nm proved to be more sensitive than PAED for nitrophenyl-glucoside (UV at 220 = 0.6ppb, PAED = 3.6ppb). However, when nitrophenyl-glucoside was spiked into urine, PAED determination resulted in 99+0.3% recovery, while UV at 220nm resulted in 116+0.2% recovery, suggesting that UV determination may suffer from matrix interference.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Conceptual challenges in the study of caregiver-care recipient relationships.

Background In the literature on family caregiving, care receiving and caregiving are generally treated as distinct constructs, suggesting that informal care and support flow in a unidirectional manner from caregiver to care recipient. Yet, informal care dynamics are fundamentally relational and often reciprocal, and caregiving roles can be complex and overlapping. Objectives To illustrate ways care dynamics may depart from traditional notions of dyadic unidirectional family caregiving and to stimulate a discussion of the implications of complex relational care dynamics for caregiving science. Approach Exemplar cases of informal care dynamics were drawn from three ongoing and completed investigations involving persons with serious illness and their family caregivers. The selected cases provide examples of three unique, but not uncommon, care exchange patterns: (a) care dyads who are aging, are chronically ill, and who compensate for one another's deficits in reciprocal relationships; (b) patients who present with a constellation of family members and other informal caregivers, as opposed to one primary caregiver; and (c) family care chains whereby a given individual functions as a caregiver to one relative or friend and care recipient to another. Conclusions These cases illustrate such phenomena as multiple caregivers, shifting and shared caregiving roles, and care recipients as caregivers. As caregiving science enters a new era of complexity and maturity, there is a need for conceptual and methodological approaches that acknowledge, account for, and support the complex, web-like nature of family caregiving configurations. Research that contributes to, and is informed by, a broader understanding of the reality of family caregiving will yield findings that carry greater clinical relevance than has been possible previously.
Role of Arabidopsis LEAFY COTYLEDON genes in seed development

Summary Embryogenesis is a critical period of the higher plant life cycle during which a single-celled zygote undergoes a series of differentiation events, leading to formation of a mature embryo that is generally desiccated and quiescent metabolically. Embryo development consists of two conceptually distinct phases: the early morphogenesis phase and the late maturation phase. Arabidopsis LEAFY COTYLEDON genes are central regulators of embryogenesis that play key roles in processes that occur during both the early and late phases. Evidence is discussed which suggests that the LEAFY COTYLEDON genes coordinate the morphogenesis and maturation phases and confer embryogenic competence to cells.
An Inextensible Association Scheme Associated with a 4-regular Graph

The scheme associated with a graph is an association scheme iff the graph is strongly regular. Consider the problem of extending such an association scheme to a superscheme in the case of a colored, directed graph. If a presuperscheme associated with a graph is of height t, then the graph satisfies the (t+3)-vertex condition. On the other hand, the current paper provides an example of a regular and 3-regular graph, satisfying the 4-vertex condition, whose association scheme cannot be extended to a presuperscheme of height 1.
Query languages for statistical databases

Statistical database management systems keep raw, elementary and/or aggregated data and include query languages with facilities to calculate various statistics from this data. In this article we examine statistical database query languages with respect to the criteria identified and taxonomy developed in Ozsoyoglu and Ozsoyoglu (1985b). The criteria include statistical metadata and objects, aggregation features and interface to statistical packages. The taxonomy of statistical database query languages classifies them with respect to the data model used, the type of user interface and method of implementation. Temporal databases are rich sources of data for statistical analysis. Aggregation features of temporal query languages, as well as the issues in calculating aggregates from temporal data, are also examined.
Automatic generation of strange attractors

Abstract A pair of coupled quadratic difference equations with randomly chosen coefficients is repeatedly iterated by computer to produce a two-dimensional map. The map is tested for stability and sensitivity to initial conditions. The process is repeated until a chaotic solution is found. In this way a computer can generate a large collection of strange attractors that are all different, and most of which have considerable aesthetic appeal. A simple computer program and examples of its output are provided. Many of the attractors have been systematically evaluated for visual appeal, and a correlation is found with the Lyapunov exponent and correlation dimension.
Caring for Patients at the End of Life: Reflections after 12 Years of Practice

Physicians have the privilege and authority to assist patients and their families at the end of life. Regardless of diagnosis, commonalities occur in the dying process, and palliative care benefits patients and families. This perspective chronicles my experience over 12 years caring for 95 patients at the end of life, illustrated in part with six vignettes. I describe interactions with families, discuss logistic issues around dying, examine the do-not-resuscitate issue, and highlight experiences with home visits. I also touch on how I communicate with the family after a death. I hope to express the significance of what I have learned while assisting patients and families at this critical juncture.
Cool flames at terrestrial, partial, and near-zero gravity

Natural convection plays an important role in all terrestrial, Lunar, and Martian-based, unstirred, static reactor cool flame and low-temperature autoignitions, since the Rayleigh number (Ra) associated with the self-heating of the reaction exceeds the critical Ra (approximately 600) for onset of convection. At near-zero gravity, Ra<600 can be achieved and the effects of convection suppressed. To systematically vary the Ra without varying the mixture stoichiometry, reactor pressure, or vessel size, cool flames are studied experimentally in a closed, unstirred, static reactor subject to different gravitational accelerations (terrestrial, 1g; Martian, 0.38g; Lunar, 0.16g; and reduced gravity, {approx}10{sup -2}g). Representative results show the evolution of the visible light emission using an equimolar n-butane:oxygen premixture at temperatures ranging from 320 to 350? deg C (593-623 K) at subatmospheric pressures. For representative reduced-gravity, spherically propagating cool flames, the flame radius based on the peak light intensity is plotted as a function of time and the flame radius (and speed) is calculated from a polynomial fit to data. A skeletal chemical kinetic Gray-Yang model developed previously for a one-dimensional, reactive-diffusive system by Fairlie and co-workers is extended to a two-dimensional axisymmetric, spherical geometry. The coupled species, energy, and momentum equations are solved numerically and themore » spatio-temporal variations in the temperature profiles are presented. A qualitative comparison is made with the experimental results. (author)« less
Identification of the transient response of SMA embedded flexible rods

This paper presents a framework for the identification of the constitutive law for a class of nonlinear models of shape memory alloys (SMA) embedded elastomeric rods. Specifically, a formulation of the transient response of elastomeric rods with embedded shape memory alloy actuators that incorporate the inherent coupling between the dynamics of deformation at the structural level, the thermal response and the constitutive law describing the shape memory alloy is described. Previous work by the authors has shown that the incorporation of shape memory alloy actuation is distributed parameter systems can induce a large class of nonlinearities including hysteresis effects in the SMA constitutive law, nonlinear kinematics of large deformation, and, in some cases, local plasticity effects. To derive a methodology to control the dynamics for the class of SMA embedded elastomeric rods considered in this paper, it is essential that the system characteristics of the nonlinear distributed parameter system be identified accurately. This paper presents an identification theory applicable to the coupled system of partial differential equations. The results are validated using both numerical simulations and experimental results.
Percutaneous translumbar and transhepatic inferior vena caval catheters for prolonged vascular access in children.

Abstract Central venous access for children with caval occlusion remains a major challenge to pediatric surgeons. Traditionally, children with superior and inferior vena cava (SVC, IVC) thrombosis have often required a thoracotomy to directly cannulate the azygos system or right atrium (RA). Recently, the possibility of placing tunneled RA catheters (RACs) by a percutaneous translumbar or transhepatic approach has become available. We report our experience of seven children with SVC and IVC obstruction who have received 11 transhepatic and 4 translumbar RACs from 1987 to 1991. All but one child was less than 2.5 years old and all were chronically dependent on parenteral nutrition. All catheters were placed in the angiography suite under general anesthesia using ultrasound guidance and Seldinger technique. This technique was successful in all seven children. Perioperative complications included accidental extubation in one patient and aspiration pneumonia in another. Mechanical complications requiring RAC replacement occurred 5 times in three infants (> 2,650 catheter days) and included catheter dislodgement (2) and thrombosis (3). In the patients with catheter thrombosis, the existing tract was successfully wired and the catheter exchanged on three occasions. Thrombolytic therapy was effective in restoring catheter patency on three other occassions. Nine episodes of catheter sepsis occurred in five children. Two late deaths occurred from infection. Of the five remaining children, four are dependent on total parenteral nutrition and have a translumbar or transhepatic catheter in situ and one child has adapted successfully to enteral feedings. Percutaneous translumbar or transhepatic IVC catheters provide excellent alternative routes for prolonged central venous access in those patients whose traditional vascular access sites are no longer available. Complications of the technique itself were minimal and although late catheter complications were not infrequent, they appear to be comparable to the standard approaches reported.
Analysis of Off-Peak Traffic Signal Operations

Abstract A traffic signal plays a major role in the overall safety and efficiency of traffic operations at an intersection. The type of operation strategy and signal timings utilized is typically based on the designed operation of the intersection at a desired Level of Service during peak traffic conditions. However, the same strategy could cause extensive vehicle delay as well as safety and security problems when lower traffic volumes are present. The main objective of this study is to define the existing off-peak issues and propose solutions to mitigate those issues. It also entails an evaluation of different traffic signal operation strategies which can be deployed to mitigate the off-peak issues. Computer simulation was utilized to optimize volumes ranging from 5 to 30 percent of peak traffic volumes on one hypothetical and two real intersections. All results showed drastic improvement on such measures of effectiveness as delay per vehicle, average speed, emission, and number of stops.
The control of intra-channel opportunism through the use of inter-channel communication

Abstract Within channels of distribution, there has been some degree of cooperation among channel members. In many cases, channel members actively cooperate with one another in competition against other channels. However, competing channels of distribution also have common interests, including controlling intra-channel opportunism. This research focuses on the use of social mechanisms for controlling intra-channel opportunism. This study investigates whether firms effectively employ inter-channel communication as a method of controlling opportunistic behavior. Under a social control mechanism, firms would pass along information concerning their channel member's reputation. Comparing two different types of firms within a single industry allows for the examination of how firm properties dictate the use of social control mechanisms.
The dynamics of the rapsyn scaffolding protein at individual acetylcholine receptor clusters.

Rapsyn, a cytoplasmic receptor-associated protein, is required for the clustering of acetylcholine receptors (AChRs). Although AChR dynamics have been extensively studied, little is known about the dynamics of rapsyn. Here, we used a rapsyn-green fluorescent protein (GFP) fusion protein and quantitative fluorescent imaging to study the dynamics of rapsyn in transfected C2C12 myotubes. First, we found that rapsyn-GFP expression at clusters did not alter AChR aggregation, function, or turnover. Quantification of rapsyn immunofluorescence indicated that the expression of rapsyn-GFP proteins at clusters does not increase the overall rapsyn density compared with untransfected myotube clusters. Using time lapse imaging and fluorescence recovery after photobleaching, we demonstrated that the recovery of rapsyn-GFP fluorescence at clusters was very fast, with a halftime of about ∼1.5 h (∼3 times faster than AChRs). Inhibition of protein kinase C significantly altered receptor insertion, but it had no effect on rapsyn insertion. When cells were treated with the broad spectrum kinase inhibitor staurosporine, receptor insertion was decreased even further. However, inhibition of protein kinase A had no effect on insertion of either rapsyn or receptors. Finally, when cells were treated with neural agrin, rapsyn and AChRs were both directed away from preexisting clusters and accumulated together in new small clusters. These results demonstrate the remarkable dynamism of rapsyn, which may underlie the stability and maintenance of the postsynaptic scaffold and suggest that the insertion of different postsynaptic proteins may be operating independently.