cssi/SciSciGPT-SciSciNet huggingface dataset:
Orthopaedic vs. Neurosurgery - Does a surgeon's specialty have an influence on 90-day complications following surgical intervention of spinal metastases?

Abstract Objectives Spinal metastases are routinely managed and/or operated on by both orthopaedic surgeons and neurological surgeons. However, controversy still exists as to whether the operating surgeon’s specialty has an impact on post-operative complication rates. Patients and methods The 2007–2017 Humana Administrative Claims database was queried using Current Procedural Terminology codes to identify patients undergoing fusions, laminectomies or osteotomy/corpectomy for spinal metastases. Physician taxonomy codes were used to identify the operating surgeon’s specialty (orthopaedic vs. neurosurgery). Multivariate logistic regression analyses were used to assess difference in 90-day complications, readmissions and mortality between the two specialties while controlling for age, gender, race, co-morbidity burden, procedural characteristics (fusion, laminectomy and/or osteotomy/corpectomy) and type of primary cancer. Results A total of 887 patients undergoing surgical intervention for spinal metastases were included – out of which 204 (23.0 %) patients were operated on by orthopaedic surgeons and 683 (77.0 %) by neurosurgeons. Following adjustment for difference in patient demographics and baseline clinical characteristics, no statistically significant differences were noted between the two specialties with regards to wound complications (p = 0.992), pulmonary complications (p = 0.461), cardiac complications (p = 0.631), thrombotic complications (p = 0.177), sepsis (p = 0.463), pneumonia (p = 0.767), urinary tract infection (p = 0.916), acute renal failure (p = 0.934), hardware complications (p = 0.892), emergency department visits (p = 0.934), 90-day readmissions (p = 0.277) and 90-day mortality (p = 0.786). Conclusions Based off our findings, it appears that a surgeon’s specialty has no influence on intermediate-term complications following surgical intervention for spinal metastases. The findings of the study should support the need for maintaining access of patients to both specialties for appropriate surgical consultation.
Psychometric properties of a single-item visual analog scale measuring goals of care in patients with advanced cancer

The purpose of this study was to examine the psychometric properties of a single-item visual analog scale (VAS) to measure goals of care in patients with advanced cancer. Data were obtained from 378 patients with diagnoses of advanced lung, gastrointestinal, or pancreatic cancer. Goal of care was measured at baseline and every 3 months until patient death or completion of the 15-month study period. A single-item VAS ranging from 0 (quality of life is all that matters) to 100 (length of life is all that matters) was used to measure patients’ goals of care for all study subjects; a subsample of subjects also completed the Quality of Life-Length of Life scale which asked patients to select categories of preferences. Test–retest reliability (intra-class correlation) and construct validity (known-groups, convergent, divergent) were evaluated. At 9 and 12 months, the test–retest reliability for patients with stable symptoms (n = 107) was established with the ICC(1,3) = 0.81, p < .001. Known-groups (r = 0.99, p < .001), convergent (r = 0.78, p < .001), and divergent (r = .06, p = 0.24) validity all demonstrated evidence of good construct validity. Preliminary psychometric testing for a single-item VAS that measures goals of care in a sample of patients with advanced cancer met standard requirements for reliability and validity. While further testing with a larger sample size is recommended, the tool’s use in the clinical area to assess cancer patients’ goals of care is appropriate. Such a tool could facilitate goals of care discussions in the clinical area.
Extracting counterexamples induced by safety violation in linear hybrid systems

Abstract Control design for linear systems typically involves pole placement and computing Lyapunov functions. While these tools are useful for ensuring stability, they are not always helpful in ensuring safety. Control designers can employ model checking as a tool for checking safety. We believe that supplementing the model checker to provide various types of counterexamples for the safety specification would help the control designer in the control development process. In this paper, we describe a technique for obtaining the variety of counterexamples for a safety violation in linear hybrid systems. More specifically, we develop algorithms to extract the longest counterexample — the execution that stays in the unsafe set for the longest contiguous time, deepest counterexample — the execution that ventures the most into the unsafe set in a user specified direction, and the robust counterexample — the unsafe execution from which some bounded perturbation yields a new counterexample. These measures for classifying counterexamples can further assist in quantifying controllers’ performance.
Clearing Opacity through Machine Learning

Artificial intelligence and machine learning provide powerful tools in many fields ranging from criminal justice to human biology to climate change. Part of the power of these tools arises from their ability to make predictions and glean useful information about complex real-world systems without the need to understand the workings of those systems. But these machine-learning tools are often as opaque as the underlying systems, whether because they are complex, nonintuitive, deliberately kept secret, or a synergistic combination of those three factors. A burgeoning literature addresses challenges arising from the opacity of machine-learning systems. This literature has largely focused on the benefits and difficulties of providing information to lay individuals, such as citizens impacted by algorithm-driven government decisions. In this Article, we explore the potential of machine learning to clear opacity — that is, to help drive scientific understanding of the frequently complex and nonintuitive real-world systems that machine-learning algorithms examine. Using multiple examples drawn from cutting-edge scientific research, we argue machine-learning algorithms can advance fundamental scientific knowledge and that deliberate secrecy around machine-learning tools restricts that learning enterprise. We examine why developers are likely to keep machine-learning systems secret, and the costs and benefits of that secrecy. Finally, we draw on the innovation policy toolbox to suggest ways to reduce secrecy so that machine learning can help us not only to interact with complex, non-intuitive real-world systems but also to understand them.
Prevalence of Flavored e-Cigarette Use Among Subpopulations of Adults in the United States.

BACKGROUND Evidence of US adult flavored e-cigarette use prevalence stratified by age, smoking status, and purpose for vaping (ie, quitting smoking, to use when or where smoking is not allowed) can inform policies that reduce the tobacco-related cancer burden. METHODS Current flavored e-cigarette use (use 1 or more nontobacco flavors) prevalence estimates were compared across subpopulation groups using 2-sided statistical significance tests in the July 2018 Current Population Survey Tobacco Use Supplement, a nationally representative cross-sectional adult survey (n = 46 759). RESULTS Current flavored e-cigarette use was reported by 1.6% (95% confidence interval [CI] = 1.47% to 1.69%) of all respondents. Among current vapers, the percentage of those who used flavored e-cigarettes was higher for adults aged 18-24 years (89.6%), 25-34 years (86.7%), and 35-44 years (76.0%) than for adults aged 45 years and older (60.4%, Ps < .001); was higher in never smokers (89.8%) than current (72.9%), long-term former (73.9%), and recent former (80.4%) smokers (Ps ≤ .009); was higher in smokers who reportedly did (78.9%) vs did not (71.1%) use e-cigarettes to vape where or when smoking is not allowed (P = .005); and did not differ between smokers who reportedly did (75.0%) vs did not (73.9%) vape to quit smoking (P = .71). Individuals who vaped to quit smoking and currently used flavored e-cigarettes constituted 0.9% (95% CI = 0.82% to 0.99%) of all adults (weighted N = 2 251 000, 95% CI = 2 046 000 to 2 476 000) and 57.2% of current flavored e-cigarette users. CONCLUSIONS Flavored e-cigarette use prevalence was low among US adults overall but common for current vapers. Flavored e-cigarette use was disproportionately prevalent among never smokers and other subpopulations that might experience harm from vaping.
Undergraduate Search for Vocation: Comparative and Interdisciplinary Studies

This paper provides an overview of what comparative studies and interdisciplinary studies are and proposes that, at the proper level of sophistication, they can add considerable value to a liberal arts education and, in the process, help undergraduates find their vocations. Undergraduate programs in comparative and interdisciplinary studies should become a resource for every student in every department and not allow themselves to become, like the disciplines, compartmentalized and isolated from each other, accessible only to a discrete group of students.
Lichen simplex chronicus of the eyelid: A case report and literature review

Abstract Purpose To report a case of Lichen simplex chronicus (LSC) of the eyelid and to perform a literature review on this topic. Observations A 59-year-old African American man presents with chronic and recalcitrant recurrent chalazion of both upper eyelids despite aggressive medical management. An incision and drainage procedure was performed along with biopsy of the eyelid, which was found to be consistent with LSC. A thorough review of the English literature pertaining to LSC of the eyelids was performed by querying PubMed and Google Scholar. Though two clinical reports of LSC of the eyelid are found in older literature, only one such case confirmed by biopsy has been reported until now. Conclusions and Importance: LSC of the eyelid is rare and this is the first reported case that is associated with chronic and recalcitrant chalazion.
Behaviorally-Selective Chemoreceptor Lesions Reveal Two Different Chemically Mediated Orientation Strategies in the Rusty Crayfish, Orconectes Rusticus

Information from environmental stimuli is essential for animals to make behaviorally and ecologically relevant decisions. We sought to determine by studying Orconectes rusticus (Girard, 1852), the relative importance of mechanical and chemical information during orientation of crayfish to food and the type of orientation strategy crayfish employ to locate attractive odor sources. This was achieved through selectively lesioning chemoreceptors, leaving mechanoreceptors intact. Chemoreceptors were lesioned by placing the olfactory appendages in 50 ppt saltwater for two hours, then a deionized water bath for 10 minutes. Crayfish were subsequently used in orientation trials with a food source of fish gelatin. Orientation videos were digitized and orientation parameters (walking speed, heading angles and turning angles) were analyzed at a population level using a polynomial regression to determine how parameters changed as a function of distance from source and experimental treatment. Through the lesioning of chemoreceptors, we determined whether crayfish were orienting using chemotaxis or odor-gated rheotaxis. Lesioned crayfish oriented to the source with significantly decreased upstream heading angles compared to controls. Regression analysis revealed that lesioned crayfish had significantly altered orientation parameters demonstrating a change in orientation strategy. Results suggest that intact crayfish are using chemical information to guide search behavior while lesioned crayfish are performing a rheotactic-type of search.
Food Intake, Water Intake, and Drinking Spout Side Preference of 28 Mouse Strains

Male mice from 28 inbred strains (129P3/J, A/J, AKR/J, BALB/cByJ, BUB/BnJ, C3H/HeJ, C57BL/6J, C57L/J, CAST/Ei, CBA/J, CE/J, DBA/2J, FVB/NJ, I/LnJ, KK/HlJ, LP/J, NOD/LtJ, NZB/BlNJ, P/J, PL/J, RBF/DnJ, RF/J, RIIIS/J, SEA/GnJ, SJL/J, SM/J, SPRET/Ei, and SWR/J) were fed chow and had access to two water bottles. Body weight, food intake, water intake, and drinking spout side preference were measured. There were large strain differences in all the measures collected, with at least a two-fold difference between strains with the lowest and the highest trait values. Estimates of heritability ranged from 0.36 (spout side preference) to 0.87 (body weight). Body weight, food intake, and water intake were interrelated among the strains, although substantial strain variation in food and water intakes independent from body weight was present. The strain differences described here provide useful information for designing mutagenesis screens and choosing strains for genetic mapping studies.
Call admission in power controlled CDMA systems

In power controlled CDMA systems, the number of users that each cell can support is limited by the total interference received at each base station and will vary with time. When a system is congested, admitting a new call can only make the link quality worse for ongoing calls and may result in call dropping. Thus, a system needs a call admission policy for new call requests to maintain acceptable connections for existing users. We use a weighted combination of call blocking and call dropping probabilities as a system performance measure. We study a transmitted power based call admission control (TPCAC) scheme that protects ongoing calls and a received power based call admission control (RPCAC) scheme that blocks new calls when the total received at a base station exceeds a threshold. The proposed schemes are evaluated by simulation of a one dimensional system and the RPCAC scheme is found to offer significant performance improvements.
Parenting Goals and Parenting Styles among Taiwanese Parents: The Moderating Role of Child Temperament

The aim of this study was to understand the moderating role of child temperament in the relationship between parenting goals and parenting styles. To achieve that goal, this study tested the interaction between child temperament (emotionality, activity, sociability, and shyness) and parenting goals (parent-centered goals and child-centered goals) that predicted authoritative and authoritarian parenting styles. One hundred forty-eight Taiwanese parents with kindergarten children were recruited to complete self-report questionnaires. Results showed main effects of parenting goals and child temperament. Child-centered goals positively predicted authoritative parenting styles, but child emotionality negatively predicted authoritative parenting styles. Parent-centered goals positively predicted authoritarian parenting styles, but child emotionality positively predicted authoritarian parenting styles. Additionally, the results showed significant interaction effect between child-centered parenting goals and child activity in predicting parental warmth. That is, parents with child-centered goals were more likely to be warm when their children had higher levels of activity. The results showed that child temperament played a moderating role in parenting styles and parenting goals. Given that child-centered parenting goals interact with child activity, future research should further examine the bidirectional relationship between child-centered parenting goals and child activity.
Movement Disorders in Chronic Regional Pain Syndrome (CRPS) (P5.271)

OBJECTIVE: The goal for this study was to determine the prevalence and clinical characteristics of movement disorders associated with Chronic Regional Pain Syndrome (CRPS) in order to gain information that could aid in development of a prospective treatment study for this condition. BACKGROUND: Chronic regional pain syndrome ( CRPS ) is a disabling disorder that often develops after a minor trauma to a limb and has been associated with a variety of movement disorders including dystonia, tremor and myoclonus. The etiology of abnormal movements in these syndromes in uncertain and to date there has been no convincing evidence for a neuroinflammatory process. Psychogenic factors are thought to be at least contributory to the movement disorder in most cases and treatment is difficult with a guarded long-term prognosis. DESIGN/METHODS: Retrospective, single center case series RESULTS: Seven patients with a diagnosis of CRPS associated movement disorder were identified in our database during 2011-2012. The majority of patients was female (6:1) and age at diagnosis ranged from 19 to 32 years. Reported trauma was often minor and onset of movement disorder followed within a few weeks after the injury, associated with skin changes and pain in the affected limb. The most common movement disorder was dystonia (85.7%) which was fixed in most cases. Treatment interventions included muscle relaxants, anticholinergics and chemodenervation with partial to complete improvement in ~40% cases. All but one patient were disabled and over 50% had associated psychiatric diagnosis. CONCLUSIONS: Movement disorders in CRPS are poorly understood with unknown etiology and are associated with psychiatric comorbidities. Young females are most commonly affected with minor limb injury resulting in significant pain and disability, requiring protracted pain management. The most common movement disorder in our series was dystonia which showed improvement in several cases with a multimodality treatment approach including medications and chemodenervation. Study Supported by: Independent Study Disclosure: Dr. Lotia has nothing to disclose. Dr. LaFaver has nothing to disclose.
The Sullivan Approach to Horizontal Restraints

In considering antitrust law's treatment of horizontal restraints "then" and "now," I am tempted to say that we began with United States v. Addyston Pipe & Steel Co.' in 1898, we are back to Addyston Pipe in 1987, and all the false starts in between have been for naught. We have not gone in a straight line, as Professor Sullivan suggests,2 but in a circle, or by some other geometrical pattern that has taken us back to the starting point. Unfortunately, the problem is not quite so simple. The basic "naked-ancillary" restraint distinction drawn in Addyston Pipe is not the final analysis but a starting point, albeit a fundamental one.3 In the search for standards synthesizing what Professor Sullivan describes as "self-executing" rules,4 on the one hand, and virtually unbridled discretion, on the other, the law is focusing on what Addyston Pipe left unanswered. Courts are attempting to structure antitrust analysis in a way that takes into account a wide variety of factors, confines judicial discretion to acceptable levels, and leads to generally acceptable outcomes.5 I believe that while "self-executing" (or per se) rules may have a place, their role is limited to the relatively few cases in which we are confident both about the characterization such rules require, and about the generalizations upon which they are predicated. In other words, per se rules are legitimate if, and only if, the conduct they prohibit is generally anticompetitive (however we may define it) and presents little oppor-
A Survey of Association-Rule Mining

The standard model for association-rule mining involves a set of "items" and a set of "baskets." The baskets contain items that some customer has purchased at the same time. The problem is to find pairs, or perhaps larger sets, of items that frequently appear together in baskets. We mention the principal approaches to eefficient, large-scale discovery of the frequent itemsets, including the a-priori algorithm, improvements using hashing, and one- and two-pass probabilistic algorithms for finding frequent itemsets. We then turn to techniques for finding highly correlated, but infrequent, pairs of items. These notes were written for CS345 at Stanford University and are reprinted by permission of the author. http://www-db.stanford.edu/~ullman/mining/mining.html gives you access to the entire set of notes, including additional citations and on-line links.
Initiation of Protein Synthesis by Folate-Sufficient and Folate-Deficient Streptococcus faecalis R: Partial Purification and Properties of Methionyl-Transfer Ribonucleic Acid Synthetase and Methionyl-Transfer Ribonucleic Acid Formyltransferase

The initiation of protein synthesis by Streptococcus faecalis R grown in folate-free culture occurs without N-formylation or N-acylation of methionyl-tRNA(f) (Met). Methionyl-tRNA synthetase and methionyl-tRNA formyltransferase were partially purified from S. faecalis grown under normal culture conditions in the presence of folate (plus-folate); the general properties of the enzymes were determined and compared with the properties of the enzymes purified from wild-type cells grown in the absence of folate (minus-folate). S. faecalis methionyl-tRNA synthetase displays optimal activity at pH values between 7.2 and 7.8, requires Mg(2+), and has an apparent molecular weight of 106,000, as determined by gel filtration, and 127,000, as determined by sucrose density gradient centrifugation. The K(m) values of plus-folate methionyl-tRNA synthetase for each of the three substrates in the aminoacylation reaction (l-methionine, adenosine triphosphate, and tRNA) are nearly identical to the respective substrate Michaelis constants of minus-folate methionyl-tRNA synthetase. Furthermore, both plus- and minus-folate S. faecalis methionyl-tRNA synthetases catalyze, at equal rates, the aminoacylation of tRNA(f) (Met) and tRNA(m) (Met) isolated from either plus-folate or minus-folate cells. S. faecalis methionyl-tRNA formyltransferase displays optimal activity at pH values near 7.0, is stimulated by Mg(2+), and has an apparent molecular weight of approximately 29,900 when estimated by sucrose density gradient centrifugation. The K(m) value of plus-folate formyltransferase for plus-folate Met-tRNA(f) (Met) does not differ significantly from that of minus-folate formyltransferase for minus-folate Met-tRNA(f) (Met). Both enzymes can utilize either 10-formyltetrahydrofolate or 10-formyltetrahydropteroyltriglutamate as the formyl donor; the Michaelis constant for the monoglutamyl pteroyl coenzyme is slightly less than that of the triglutamyl pteroyl coenzyme for both transformylases. Tetrahydrofolate and uncharged tRNA(f) (Met) are competitive inhibitors of both plus- and minus-folate S. faecalis formyltransferase; folic acid, pteroic acid, aminopterin, and Met-tRNA(m) (Met) are not inhibitory. These results indicate that the presence or absence of folic acid in the culture medium of S. faecalis has no apparent effect on either methionyl-tRNA synthetase or methionyl-tRNA formyltransferase, the two enzymes directly involved in the formation of formylmethionyl-tRNA(f) (Met). Therefore, the lack of N-formylation of Met-tRNA(f) (Met) in minus-folate S. faecalis is due to the absence of the formyl donor, a 10-formyl-tetrahydropteroyl derivative. Although the general properties of S. faecalis methionyl-tRNA synthetase are similar to those of other aminoacyl-tRNA synthetases, S. faecalis methionyl-tRNA formyltransferase differs from other previously described transformylases in certain kinetic parameters.
Personal noise dosimeters: Accuracy and reliability in varied settings

This study investigated the accuracy, reliability, and characteristics of three brands of personal noise dosimeters (N = 7 units) in both pink noise (PN) environments and natural environments (NEs) through the acquisition of decibel readings, Leq readings and noise doses. Acquisition periods included repeated PN conditions, choir room rehearsals and participant (N = 3) Leq and noise dosages procured during a day in the life of a music student. Among primary results: (a) All dosimeters exhibited very strong positive correlations for PN measurements across all instruments; (b) all dosimeters were within the recommended American National Standard Institute (ANSI) SI.25-1991 standard of ±2 dB (A) of a reference measurement; and (c) all dosimeters were within the recommended ANSI SI.25-1991 standard of ±2 dB (A) when compared with each other. Results were discussed in terms of using personal noise dosimeters within hearing conservation and research contexts and recommendations for future research. Personal noise dosimeters were studied within the contexts of PN environments and NEs (choral classroom and the day in the life of collegiate music students). This quantitative study was a non-experimental correlation design. Three brands of personal noise dosimeters (Cirrus doseBadge, Quest Edge Eg5 and Etymotic ER200D) were tested in two environments, a PN setting and a natural setting. There were two conditions within each environment. In the PN environment condition one, each dosimeter was tested individually in comparison with two reference measuring devices (Ivie and Easera) while PN was generated by a Whites Instrument PN Tube. In condition two, the PN procedures were replicated for longer periods while all dosimeters measured the sound levels simultaneously. In the NE condition one, all dosimeters were placed side by side on a music stand and recorded sound levels of choir rehearsals over a 7-h rehearsal period. In NE, condition two noise levels were measured during a day in the life of college music students. Three participants each wore two types of dosimeters for an 8-h period during a normal school day. Descriptive statistical analyzes including means, standard deviation and Pearson product-moment correlation. The primary finding is that the dosimeters in this study recorded results within ±2 dB of either a reference measurement or within dosimeters in all four conditions examined. All dosimeters studied measured steady noise source accurately and consistently, with strong positive correlations across all instruments. Measurements acquired during choral rehearsals indicated a maximum of 1.5 dB difference across dosimeters. The Etymotic research personal noise dosimeters (ER200D) could provide individuals and schools of music with a relatively inexpensive tool to monitor sound doses. Findings from this study suggest that the three brands of dosimeters tested will provide reliable Leq levels and hearing dosages in both PN and natural settings.
Near-total pancreatectomy for hyperinsulinism. Spontaneous remission of resultant diabetes.

. Persistent hyperinsulinism in the newborn may warrant surgical intervention to prevent neurologic sequelae. Subtotal pancreatectomy may not be adequate, necessitating near-total pancreatectomy with subsequent development of diabetes mellitus. We report an infant with hyperinsulinemic hypoglycemia who underwent near-total pancreatectomy. The postoperative period was characterized by insulin-dependency and extreme insulin sensitivity. Clinical follow-up and C-peptide determinations showed a return of insulin secretory capacity permitting the discontinuation of insulin therapy after five months. This experience reaffirms the potential for a favorable outcome after near-total pancreatectomy in the newborn period for severe hyperinsulinism.
Comparative Reliabilities and Ease of Construction of Thurstone and Likert Attitude Scales

(1962). Comparative Reliabilities and Ease of Construction of Thurstone and Likert Attitude Scales. The Journal of Social Psychology: Vol. 58, No. 1, pp. 109-120.
Asymmetric Acylation Reactions Catalyzed by Conformationally Biased Octapeptides

Abstract Octapeptides capable of adopting β-hairpin conformations have been found to function as efficient catalysts for the kinetic resolution of certain racemic secondary alcohols. Parallel solid phase synthesis of a series of peptides with the common feature of the d -Pro-Gly sequence at the turn region ( i +3 to i +4) was carried out to yield a family of octapeptide catalysts. The peptides were then screened for their efficiency in a number of enantioselective acylation reactions.
Malignant Mesothelioma and Occupational Exposure to Asbestos: A Clinicopathological Correlation of 1445 Cases

Asbestos exposure is indisputably associated with development of mesothelioma. However, relatively few studies have evaluated the type of occupational exposure in correlation with asbestos fiber content and type. This study reports findings in 1445 cases of mesothelioma with known exposure history; 268 of these also had fiber burden analysis. The 1445 cases of mesothelioma were subclassified into 23 predominant occupational or exposure categories. Asbestos body counts per gram of wet lung tissue were determined by light microscopy. Asbestos fiber content and type were determined by scanning electron microscopy and energy dispersive x-ray analysis. Results were compared with a control group of 19 lung tissue samples. Ninety-four percent of the cases occurred among 19 exposure categories. Median asbestos body counts and levels of commercial and noncommercial amphibole fibers showed elevated levels for each of these 19 categories. Chrysotile fibers were detectable in 36 of 268 cases. All but 2 of these also had above-background levels of commercial amphiboles. When compared to commercial amphiboles, the median values for noncommercial amphibole fibers were higher in 4 of the 19 exposure groups. Most mesotheliomas in the United States fall into a limited number of exposure categories. Although a predominant occupation was ascertained for each of these cases, there was a substantial overlap in exposure types. All but 1 of the occupational categories analyzed had above-background levels of commercial amphiboles. Commercial amphiboles are responsible for most of the mesothelioma cases observed in the United States.
Three-dimensional distortion model for magnetic resonance images

Magnetic resonance imaging (MRI) has progressed rapidly within the last decade. In addition to better soft tissue discrimination than CT, MRI is capable of imaging a volume in multiple planes. If these planes can be accurately registered, it is possible to create a 3-D image database. This 3-D database can then be used to generate considerably more accurate target coordinates for use in applications such as stereotaxic neurosurgery or radiation oncology where precise measurements are required. Despite these advantages, use of MRI in these applications has been limited because of fundamental questions about the geometric accuracy of the images. Distortion in MR images is inevitable because of nonlinearities and inhomogeneities in the magnetic gradient fields that are used for spatial encoding of the signal. We have developed a model for this distortion which has allowed us to minimize the localization errors using MR images and to improve the geometric correspondence between images acquired in different planes. A special phantom is imaged and analyzed to determine machine dependent parameters for the distortion model. These parameters may then be applied to the geometric correction of patient images, which are acquired separately. The model has been incorporated into an integrated stereotaxic planning system designed for interactive use in the operating room. In this paper, we present details of the model and experimental results.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The effects of electricity pricing on PHEV competitiveness

Plug-in hybrid electric vehicles (PHEVs) will soon start to be introduced into the transportation sector, thereby raising a host of issues related to their use, adoption and effects on the electricity sector. Their introduction has the potential to significantly reduce carbon emissions from the transportation sector, which has led to government policies aimed at easing their introduction. If their widespread adoption is set as a target it is imperative to consider the effects of existing policies that may increase or decrease their adoption rate. In this study, we present a micro level electricity demand model that can gauge the effects of PHEVs on household electricity consumption and the subsequent economic attractiveness of the vehicles. We show that the electricity pricing policy available to the consumer is a very significant factor in the economic competitiveness of PHEVs. Further analysis shows that the increasing tier electricity pricing system used in California will substantially blunt adoption of PHEVs in the state; and time of use electricity pricing will render PHEVs more economically attractive in any state.
Structure and Evolution of Winter Cyclones in the Central United States and Their Effects on the Distribution of Precipitation. Part I: A Synoptic-Scale Rainband Associated with a Dryline and Lee Trough

Abstract A convective rainband, which was approximately 1500 km in length and affected large areas of the central United States for about 16 h, developed within an evolving winter cyclone. The rainband, which will be referred to as the pre-drytrough rainband, formed approximately 400 km ahead of a developing dryline and lee trough (drytrough, for short) that created an elevated, sloping layer of convective instability. The presence of a deep pool of high-potential-temperature air in the middle troposphere over the south-central United States, advected there from the elevated terrain to the southwest (i.e., an elevated mixed layer), produced a region of warm-air advection downstream of the high terrain. This enhanced the lifting associated with a migrating short wave aloft and generated the pre-drytrough rainband. In previous studies the dryline, the lee trough, the elevated mixed layer, and the low-level jet in the central United States have generally been viewed as isolated features. Here the authors pre...
Nonorthogonal tight-binding molecular-dynamics scheme for silicon with improved transferability

Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506~Received 9 September 1996!A previously proposed @Phys. Rev. B 50, 11 577 ~1994!# generalized tight-binding theory for silicon incor-porating explicit use of nonorthogonality of the basis is modiﬁed to improve transferability. Better agreementis obtained over the original scheme for bond lengths, high-pressure bulk phases, and vibrational frequencies.@S0163-1829~97!03716-8#I. INTRODUCTION
Hot Surface Ignition of Automotive and Aviation Fluids

Although ignition of flammable liquids by hot surfaces is well known in the automotive and aviation industries, little fundamental research has been conducted to understand this ignition mechanism and only limited data is available in the literature. In this paper, we present results from over 2,500 ignition tests using a simple, highly reproducible experimental set-up involving a horizontal flat plate, a single drop of liquid and a quiescent environment. Results from the 14 automotive and aviation fluids tested showed that ignition was probabilistic, that the probabilistic behavior occurs over a relatively broad temperature range and that the data can be treated statistically using logistic regression. This statistical approach offers the advantages of inference and diagnostic techniques which parallel those of linear regression, and provides a well-defined relationship between surface temperature and ignition probability.
Fine Tuning Our Cellular Factories: Sirtuins in Mitochondrial Biology

Sirtuins have emerged in recent years as critical regulators of metabolism, influencing numerous facets of energy and nutrient homeostasis. Here, we review recent advances on the role of this fascinating family of mammalian proteins and their well-orchestrated function in modulating mitochondrial activity.
High electric fields in CdS

Abstract A technique has been developed for measuring and studying high electric fields in CdS crystals. Fields are produced by a transparent blocking electrode in direct contact with a conducting crystal. D.C. field-effect experiments have been used to measure the magnitude of the electric field and its distribution within the crystal. Electro-optic effects occur in fields greater than 10 5 V/cm and dielectric breakdown occurs in fields greater than 10 6 V/cm. The main electro-optic effect is a shift of the optical band edge to longer wavelengths with increasing fields. Dielectric breakdown field strengths have been measured in a variety of crystals. The mechanism of dielectric breakdown has been studied by several kinds of experiments including measurement of pre-breakdown currents as a function of field and study of the behavior of optically injected carriers as breakdown proceeds. A comparison of results with theoretical treatments of dielectric breakdown indicates that the breakdown is due to tunneling.
Quasi-bound states in H2

Abstract A new method for the easy determination of quasi-bound states is proposed. The method is used in a discussion of the two observed quasi-bound levels in molecular hydrogen.
Core-Sets For Canonical Correlation Analysis

Canonical Correlation Analysis (CCA) is a technique that finds how "similar" are the subspaces that are spanned by the columns of two different matrices A έℜ(of size m-x-n) and B έℜ(of size m-x-l). CCA measures similarity by means of the cosines of the so-called principal angles between the two subspaces. Those values are also known as canonical correlations of the matrix pair (A,B). In this work, we consider the over-constrained case where the number of rows is greater than the number of columns (m > max(n,l)). We study the problem of constructing "core-sets" for CCA. A core-set is a subset of rows from A and the corresponding subset of rows from B - denoted by Â and B, respectively. A "good" core-set is a subset of rows such that the canonical correlations of the core-set (Â, B) are "close" to the canonical correlations of the original matrix pair (A, B). There is a natural tradeoff between the core-set size and the approximation accuracy of a core-set. We present two algorithms namely, single-set spectral sparsification and leverage-score sampling, which find core-sets with additive-error guarantees to canonical correlations.
A MODAL APPROACH TO THE TRANSIENT ANALYSIS OF SYNCHRONOUS MACHINES

ABSTRACT A novel method for calculating the transient currents, flux linkages and electromagnetic torque of a synchronous machine following a sudden voltage disturbance is presented. The solution is obtained for a sudden change from an arbitrary balanced to an arbitrary unbalanced voltage condition. Since minimum constraints are placed on the disturbance, many typical types of transients such as three-phase and line-to-line short-circuit faults can be accommodated. Complete solutions for all machine currents are obtained as explicit functions of time. Any number of rotor circuits can be included and full allowance is inherently made for coupling between all stator and rotor circuits. Constant speed is assumed but no additional approximations are made other than those implicit in the derivation of Park's Equations. The technique incorporates the state space concept of modal analysis in its implementation. Closed form solutions obtained by the modal theory are compared with standard solution techniques
Antibody- and receptor-based biosensors for detection and process control

The extension of a generic immobilization technology for the fabrication of antibody- and receptor-based biosensors is reported. The biosensors utilize polymerized protein films containing the antibody or receptor and appropriate stabilizers to coat an interdigitated electrode transducer. Changes in the electrical field of the coated electrodes are related to specific interactions between the immobilized biomolecule and the analyte to be measured. A portable electronics module has been developed into which the coated electrode chips are inserted and challenged with analyte. Within 5–10 s, an output reading (change in impedance, phase angle, current or voltage) is obtained that is related to analyte concentration. The use of parallel, non-antibody or non-receptor containing control chips allows automatic correction for background and non-specific binding. The biosensors can detect low ng ml−1 levels of analyte in serum or other liquids. Such antibody- and receptor-based biosensors are applicable to the determination of a wide range of analytes for analytical, clinical, environmental and process control applications.
Spectral gap for convex planar domains

A sharp lower bound is proved for the spectral gap of convex domains in the plane. Dirichlet boundary conditions are imposed on the Laplacian.
High-performance computing and the cloud: a match made in heaven or hell?

Infrastructure clouds offer tremendous potential for scientific users, however, they face numerous challenges that must be addressed before they are widely adopted by scientific communities.
Rhamnus cathartica (Rosales: Rhamnaceae) Invasion Reduces Ground-Dwelling Insect Abundance and Diversity in Northeast Iowa Forests

European buckthorn (Rhamnus cathartica L.) is an invasive woody shrub in deciduous forests of the Upper Midwest. Studies have suggested buckthorn invasion has negative effects on native plants, soil, and ecosystems, but its impacts on insects are largely unstudied. To test the impact of buckthorn invasion on ground-dwelling insects in forests of northeastern Iowa, pitfall traps were used to sample ground-dwelling insects at five sites four different periods from June to August 2013. Each site had three treatments: areas heavily infested with buckthorn, areas where buckthorn has not established, and areas where buckthorn had been removed within the past 2-10 yr. Most insects were identified to family and quantified; while ground beetles (Coleoptera: Carabidae) and ants (Hymenoptera: Formicidae) were identified to species and quantified. In total, 11,576 insects representing eight orders and 46 families were collected. Areas uninvaded by buckthorn had significantly greater insect abundance and taxonomic richness than areas invaded by buckthorn. Of the 948 ground beetles representing 40 species, abundance, species richness, and Shannon diversity indices were significantly lower in areas invaded by buckthorn compared with areas with no buckthorn. The 2,661 ants from 24 species had similar trends, but treatment differences were not significant because of high variability. These results clearly show a negative impact of buckthorn invasion on the abundance and taxonomic richness of ground-dwelling insects.
Superadiabatic Excess and Gravity Wave Saturation

Abstract Attention is called to a recent calculation of the superadiabatic excess—the ratio of wave amplitude at saturation to wave amplitude at convective instability threshold—caused by a saturated gravity wave. (This excess is also referred to as the degree of supersaturation). The implications of this excess for linear saturation by convective instability are pointed out. Errors and misprints in the recent calculation are also pointed out and corrected.
A new species of Eremogone (Caryophyllaceae) from northern Utah and southeastern Idaho, U.S.A.

A name (Eremogone loisiae) is provided for those plants from northern Utah and southeastern Idaho that have gone under the misapplied name Eremogone kingii subsp. uintahensis. Eremogone loisiae, named in honor of Lois A. Arnow, is distinguished from E. kingii by its longer and narrower, flexuous leaves and its longer sepals, petals, styles, capsules, and seeds.
The Stench of Disease: Public Health and the Environment in Late-Medieval English towns and cities

Normal 0 false false false MicrosoftInternetExplorer4 This article explores the urban environmental concerns of late-medieval English towns and cities and argues that these urban areas had a form of public health. During this period, regulations that focused on maintaining the good health of town and city inhabitants were created and enforced. Among other things, these regulations focused on reducing unsanitary trade practices, protecting water sources, eliminating foul smells from the air, and preventing the consumption of bad food and water. They also represented a practical application of medieval theories and perceptions of disease—namely that disease was linked to bad smells. Rather than lacking any form of public health due to medieval theories of disease, they actively pursued it due to the ancient and medieval link between environmental health and physical health.
Evidence for the absence of gluon orbital angular momentum in the nucleon

The Sivers mechanism for the single-spin asymmetry in unpolarized lepton scattering from a transversely polarized nucleon is driven by the orbital angular momentum carried by its quark and gluon constituents, combined with QCD final-state interactions. Both quark and gluon mechanisms can generate such a single-spin asymmetry, though only the quark mechanism can explain the small single-spin asymmetry measured by the COMPASS collaboration on the deuteron, suggesting the gluon mechanism is small relative to the quark mechanism. We detail empirical studies through which the gluon and quark orbital angular momentum contributions, quark-flavor by quark-flavor, can be elucidated.
Establishing and Maintaining a Library Outreach Program

Although the term ‘outreach’ is used frequently in the library and information science literature, it is by definition not limited to a library setting. Instead, outreach tends to be defined by the...
Information processing using number systems with bases higher than ten

Three groups of S s were given extended training with artificial number systems on bases of 15, 20, and 25, respectively. It was expected that the increased information load per symbol in these higher-than-10 systems would increase memory span efficiency and speed for comparable addition problems as a function of increases in the number base. The results indicated that base-20 S s were significantly superior, in memory span, with base-15 S s about equal to their base-10 performance. Addition tests showed better performance (speed) for base-20 than for base-15 S s. Resignation of S s prevented evaluation of the base-25 condition. It was concluded that an optimal number base for the tasks studied is at least higher than 15.
Examination of the platinum effect on the oxidation behavior of nickel-aluminide coatings

Abstract Oxidation resistant nickel-aluminide coatings are designed to develop a protective alumina scale during high temperature exposure. It is well established that platinum additions, typically about 6–8 at.%, provide substantial improvements in oxidation resistance of such coatings, yet the nature of the platinum effect is still not fully understood. In this work, the oxidation behavior of two commercial NiAl and NiPtAl coatings deposited on the same Ni-base single crystal alloy CMSX-4 was analyzed. Cyclic and isothermal oxidation tests were conducted at 1150 °C in air. Microstructure development and alumina/coating interface chemistry were studied as a function of oxidation time. Numerous voids developed at the Al 2 O 3 /NiAl interface, and sulfur was found to segregate at the void surfaces and at the contact interface, leading to spallation of the scale over the convex areas along ridges on the coating surface. The presence of platinum prevented sulfur segregation and void formation at the Al 2 O 3 /NiPtAl interface. As a result, the Al 2 O 3 scale on the NiPtAl coating remained adherent and virtually no spallation was observed even after prolonged cyclic oxidation.