cssi/SciSciGPT-SciSciNet huggingface dataset:
The Luminescence and Display Division (LDM) of The Electrochemical Society

Luminescence, the emission of light by a material after it has been exposed to ultraviolet radiation (UV) radiation, electron bombardment, X-rays or some other method of excitation, has fascinated people since ancient times. Even as late as the early 1900s, Thomas Edison and E. L. Nichols concluded "unless someone discovers a means of making luminescent bodies that are vastly brighter than the best known now, luminescence may be excluded altogether as a factor in artificial lighting."
Hybrid-pair ratio adjustable power splitters for add-on RF shimming and array-compressed parallel transmission.

PURPOSE A ratio adjustable power splitter (RAPS) circuit was recently proposed for add-on RF shimming and array-compressed parallel transmission. Here we propose a new RAPS circuit design based on off-the-shelf components for improved performance and manufacturability. THEORY AND METHODS The original RAPS used a pair of home-built Wilkinson splitter and hybrid coupler connected by a pair of connectorized coaxial cables. Here we propose a new hybrid-pair RAPS (or HP-RAPS) circuit that replaces the home-built circuits with two commercially available hybrid couplers and replaces connectorized cables with interchangeable microstrip lines. We derive the relation between the desired splitting ratio and the required phase shifts for HP-RAPS and investigate how to generate arbitrary splitting ratios using paired meandering and straight lines. Several HP-RAPSs with different splitting ratios were fabricated and tested on the workbench and MRI experiments. RESULTS The splitting ratio of an HP-RAPS circuit has a tan or cot dependence on the meandering line's additional length compared to the straight line. The fabricated HP-RAPSs exhibit accurate splitting ratios as expected (<4% deviations) and generate transmit fields that well agree with predicted fields. They also demonstrated a low insertion loss of 0.33 dB, high output isolation of -26 dB, and acceptable impedance matching of -16 dB. CONCLUSION A novel HP-RAPS circuit was developed and implemented. It is easy-to-fabricate/reproduce with minimal expertise. It also preserves the features of the original RAPS circuit (ratio-adjustable, small footprint, etc.) with lower insertion loss.
The potential of Hudson Valley glacial floods to drive abrupt climate change

The periodic input of meltwater into the ocean from a retreating Laurentide Ice Sheet is often hypothesized to have weakened the Atlantic meridional overturning circulation (AMOC) and triggered several cold periods during the last deglaciation (21,000 to 8,000 years before present). Here, we use a numerical model to investigate whether the Intra-Allerod Cold Period was triggered by the drainage of Glacial Lake Iroquois, ~13,300 years ago. Performing a large suite of experiments with various combinations of single and successive, short (1 month) and long (1 year) duration flood events, we were unable to find any significant weakening of the AMOC. This result suggests that although the Hudson Valley floods occurred close to the beginning of the Intra-Allerod Cold Period, they were unlikely the sole cause. Our results have implications for re-evaluating the relationship of meltwater flood events (past and future) to periods of climatic cooling, particularly with regards to flood input location, volume, frequency, and duration. Drainage of Glacial Lake Iroquois via the Hudson Valley about 13,300 years ago did not weaken the Atlantic Meridional Overturning Circulation substantially, suggests a suite of simulations with a global-ocean general circulation model.
Detecting continuous gravitational waves with superfluid 4He

Institute for Quantum Information and Matter; NSF Physics Frontiers Center [NSF IQIM-1125565]; Gordon and Betty Moore Foundation [GBMF-1250]; NSF [DMR-1052647]; DARPA-QUANTUM [HR0011-10-1-0066]; NSF ITAMP grant; Army Research Office
Metadamping enhancement and tunability via scissor-like electromechanical metamaterials

We report on a novel scissor-like electromechanical metamaterial (SEMM) with enhanced and tunable damping properties, stemming from its electromechanical resonant effects. The displacement amplification mechanism of the scissor-like structure in SEMM is exploited to amplify the damping ratio for stronger vibration mitigation through the enhanced electrical dissipation of the amplified voltage of the piezoelectric element. The relative dissipation performance, termed as metadamping, is quantified based on complex band structures, which allow frequencies to be complex valued. Using different shunting circuits, the overall damping performance of SEMM is demonstrated to be higher than a statically equivalent traditional systems, such as acoustic metamaterials and monatomic lattices. The dissipation performance of SEMM is numerically verified via finite structure analysis and found to be in an excellent agreement with Bloch’s wave analysis. Furthermore, the electromechanical nature of the piezoelectric material in SEMM provides a convenient way to tune the metadamping by adjusting the piezoelectric shunting circuit.
How Virginia Public School Superintendents Spend Their Time

HOW VIRGINIA PUBLIC SCHOOL SUPERINTENDENTS SPEND THEIR TIME By Eric Timothy Armbruster, Ph.D. A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University. Virginia Commonwealth University, 2011 Major Director: Whitney H. Sherman, Ph.D. Associate Professor and Dissertation chair Department of Educational Leadership School of Education The purpose of this research is to examine how Virginia public school superintendents spend their time. The primary goal of this study is to determine the differences in how superintendents allocate their time in regards to their involvement with specific tasks. This descriptive study is designed to determine the level of involvement of superintendents throughout the state of Virginia in the areas of fiscal management, facility management, personnel, student personnel and special services, support services, instruction and curriculum, and community relations. This study investigates how much time is spent by superintendents in specific performance areas as defined by the Guidelines for Uniform Performance Standards and Evaluation Criteria for Superintendents. It also examines differences in superintendents’ time and task apportionment related to differences in superintendent experiences, as defined by gender, years in current position, size of school division, and student achievement of the school division. Furthermore, it investigates to what extent the experiences of superintendents as defined by gender, years in current position, size of school division, and student achievement of the school division explain a need for professional development in each of the criteria of the Guidelines for Uniform Performance Standards and Evaluation Criteria for Superintendents? The results of this study may reveal a need for professional development in specific evaluation criteria areas related to planning and assessment, instructional leadership, and safety and organizational management for learning. The identified superintendent levels of time and task apportionment for professional development in specific performance criteria may assist superintendents, school board members, and professional support organizations in planning and implementing professional development for superintendents to meet specific learning needs. Recommendations of the study may include: differentiated professional development offerings for superintendents, more executive training opportunities for superintendents, replication of this study in other states, establishment of national standards for performance and evaluation, and a follow-up study of why superintendents desire professional development in specific criteria areas.
System Identification of Frames under Seismic Loads

In this paper system identification algorithms are employed to construct appropriate nonlinear models of real structures, undergoing seismic disturbances. A three-story half-scale steel frame of the moment resisting type is modeled as a “shear” frame. The data for this frame were obtained from the Earthquake Engineering Research Center of the University of California. The restoring forces in this model are assumed to be of the viscous differential type, containing four unknown parameters. The solution of the problem, that is, the identification of state parameters, is sought by nonlinear filtering methods. The invariant imbedding filter is presented as a special case of a novel dynamic programming filter. In a purely experimental fashion, it is shown that the adopted model is identifiable and stable by utlizing simulated and real data. Abundant numerical experiments are performed; some of the results are presented. By adding corrective nonlinear terms to the basic linear model, the predictive ability of the model is demonstrated.
Superstrings — A Brief History

In this lecture I will present a brief history of the development of superstring theory, with an emphasis on my own contributions. I will not attempt to give a comprehensive history of string theory, which would deserve an entire dedicated conference of its own. Also, this talk will neither teach you string theory nor try to convince you that it is correct.
Dickens Redux: How American Child Labor Law Became a Con Game

Millions of American teens are employed today in a variety of workplaces. The jobs they hold typically provide little human capital for their future economic self-sufficiency and pose substantial immediate and long-term safety, academic, and behavioral risks for this generation. This Article seeks to answer the question of how American law and society reached this situation, which has disastrous effects for working youth, their families, and society as a whole. Three main themes are developed. First, child labor has always been part of the American economy, from colonial times until today. While there has been more than 150 years of effort to curtail youth employment, this movement has been generally unsuccessful at both federal and state levels. Second, the federal courts, and particularly the United States Supreme Court, defeated repeated statutory attempts to restrict child labor. This judicial activism is demonstrated by the previously untold factual and legal history of several cases, especially the decision in Hammer v. Dagenhart. Finally, with Locknerism demolished by the Great Depression of the 1930s, the passage of the Fair Labor Standards Act of 1938 was to be the death knell for child labor. This victory was, in fact, pyrrhic. The weaknesses of the FLSA resulted in the continuation of youth employment. These statutory deficiencies were the outcome of a toxic combination of factors: profits from cheap labor, entrenched and powerful economic interests, and racism.
Comparison of the 2011 Mississippi River Flood to the MR-T Project Design Flood

AbstractDuring the period of April 19 to May 4, 2011, an unusually large amount of precipitation fell across the middle to lower portion of the Mississippi River basin and resulted in record flooding in many locations. The greatest amount of moisture, with rainfall totals near or in excess of 508 mm (20 in.), was located throughout northern Arkansas, southern Missouri, far southern Illinois, and western Kentucky. This study determined, using the procedures outlined in the Manual on Estimation of Probable Maximum Precipitation of the World Meteorological Organization (WMO), the extent of how much more precipitation could have occurred in the same region from the same storms if the maximum possible amount of moisture had been available. A detailed examination of the synoptic weather conditions from mid-April through early May in 2011 indicated that two distinct systems affected the region with heavy rainfall during that period. National Weather Service radar and surface observation data from each storm was ...
A Discussion of Technology and Productivity in the Firm

We begin this discussion by summarizing the findings/contributions of each paper and then raise several questions with regard to methodology/ findings. We close with suggestions for additional research. We start with the paper by Wolff.
Issues in State Newborn Screening Programs

These are heady times for newborn screening. Articles in the medical literature and speakers at grand rounds urge us to test babies for disorders, including cystic fibrosis, 1 biotinidase deficiency, 2 and medium-chain acyl coenzyme A dehydrogenase deficiency. 3 States are expanding the batteries of tests they perform. My own state of Tennessee just began testing neonates for galactosemia this year. And this is no doubt just the beginning. New techniques are being developed that will make it possible to look for a host of genetic characteristics using microscopic amounts of blood. We soon may be able to discern many conditions and characteristics of our children.
A two-dimensional ultrasonic model study of compressional and shear-wave diffraction patterns produced by a circular cavity

Diffraction patterns of compressional (P) and shear (SV) waves produced by a circular hole were experimentally obtained on a two-dimensional ultrasonic model. The shapes of the Fresnel patterns were found to depend on, 1) α/λ, the ratio of the radius of the cylinder to the wavelength; and, 2) the wave type. The transitional zone between the illuminated and the shadow regions broadens, and the half-amplitude point shifts away from the geometrical shadow as α/λ decreases. For comparable α/λ, the shadow boundary of the SV wave appears to start much earlier than that of the P wave.
Anesthesia Oral Board Review: Knocking Out The Boards

The accreditation process for anesthesia in the United States is considered one of the most difficult in all medical specialties, with residents required to pass both an oral and written exam to gain certification. This book is specially designed for the American Board of Anesthesiology Oral Examination. The evidence-based approach is presented in a concise outline-oriented format, with an emphasis on test results and visual images. The Knockout Treatment Plan demonstrates the correct method of managing the case to the satisfaction of the examiners, while the Technical Knockout sections give additional tips for successfully passing the examination. The straightforward format of this book makes it suitable not only as an oral review book but also as an introduction to anesthesia rotations for medical students, medical interns, and nurse anesthetist students; furthermore, the book can be used as a technical study guide for anesthesia residents. More than 100 topics in this book have already been board-review tested by residents.
Dechlorination of trichlorofluoromethane (CFC-11) by sulfate-reducing bacteria from an aquifer contaminated with halogenated aliphatic compounds.

Groundwater samples were obtained from a deep aquifer contaminated with halogenated aliphatic compounds. One-milliliter samples contained 9.2 x 10(5) total bacteria (by acridine orange microscopic counts) and 2.5 x 10(3) sulfate-reducing bacteria (by most probable number analysis). Samples were incubated anaerobically in a basal salts medium with acetate as the electron donor and nitrate and sulfate as the electron acceptors. Residual levels of trichlorofluoromethane (CFC-11) in samples were biotically degraded, while trichloroethylene was not. When successively higher levels of CFC-11 were added, increasingly rapid degradation rates were observed. Concomitant with CFC-11 degradation was the near stoichiometric production of fluorodichloromethane (HCFC-21); the production of HCFC-21 was verified by mass spectrometry. CFC-11 degradation was dependent on the presence of acetate (or butyrate) and sulfate but was independent of nitrate. Other carbon sources such as lactate and isopropanol did not support the degradation. The addition of 1 mM sodium sulfide completely inhibited CFC-11 degradation; however, degradation occurred in the presence of 2 mM 2-bromoethanesulfonic acid. These results indicate that the anaerobic dechlorination of CFC-11 is carried out by sulfate-reducing bacteria and not by denitrifying or methanogenic bacteria. Images
The easy way to move windows profiles and data

The idea of replacing faculty and staff computers can be daunting, to say the least, and data transfers have always been an inefficient monster. This year, Bucknell University has integrated the latest version of Microsoft's free User State Migration Tool into our desktop replacement process, allowing us to migrate multiple users and their data from one machine to another without any need for the client's presence.The User State Migration Tool has allowed us to drastically reduce the amount of time and user interaction required to replace faculty and staff computers.In order to successfully use this tool in our workflow, we needed to perform several important customizations: 1. Create custom INF files so the tool will only migrate the data we wanted to keep. 2. Create GUI front ends to either remotely back up a client's profile to a network drive or remotely back up a profile to a new machine and automatically load the profile on the new machine. 3. Create a webpage that allows us to view the status of all the profile transfers that are currently in progress. By customizing and automating the User State Migration Tool, we have been able to streamline our desktop replacement process and reduce the time spent and manpower needed to re-image existing computers and setup newly deployed computers.
Effects of vitamin A deficiency on the levels and distribution of retinol-binding protein and marker enzymes in homogenates and Golgi-rich fractions of rat liver.

Abstract The levels of retinol-binding protein, prealbumin, and several ‘marker’ enzymes were determined in homogenates, crude subcellular fractions and isolated Golgi apparatus prepared from the livers of vitamin A-deficient and control rats. Vitamin A deficiency led to a marked increase (3.5-fold) in hepatic retinol-binding protein concentration and to slight increases in hepatic prealbumin levels, without affecting the levels of a number of marker enzymes localized in various subcellular compartments. The distributions of total protein and marker enzymes among various subcellular fractions were nearly identical in control and vitamin A-deficient preparations. In particular, vitamin A deficiency had no effect on the yield or enzymatic composition of isolated Golgi-rich fractions. In vitamin A-deficient rats, where the normal secretion of retinol-binding protein was blocked, a maximum of less than 10% of the total liver retinol-binding protein was accounted for in the Golgi. In contrast, in control rats, where the secretion of retinol-binding protein was proceeding at the normal rate, the relative amount of retinol-binding protein in Golgi increased to about 23% of the total liver pool. The data suggest that the Golgi apparatus is involved in the pathway of retinol-binding protein secretion from the liver, but demonstrate that the Golgi is not the major subcellular locus for retinol-binding protein in either normal or vitamin A-deficients rats.
NUMERICAL RESULTS FOR THE AUXILIARY EQUATION OF RADIATIVE TRANSFER

Abstract A basic problem is astrophysics, meteorology and neutron transport theory us the determination of the internal intensity produced when uniform parallel rays illuminate a slab of finite thickness which both absorbs and scatters radiation isotropically. One approach to this problem is through the intermediate step of determining the source function which represents the rate of production of scattered radiation per unit volume per unit solid angle as a function of the depth below the top surface. Ordinarily this function is characterized as the solution of a singular integral equation, which presents difficulties from the numerical viewpoint. In earlier memoranda the authors derived other differential integral equations for the source function viewed as a function of the thickness of the slab. In this memorandum they present the results of extensive calculations of source functions in both graphical and tabular form.
Low-intensity exercise as a modifier of physical frailty in older adults.

Brown M, Sinacore DR, Ehsani AA, Binder EF, Holloszy JO, Kohrt WM. Low-intensity exercise as a modifier of physical frailty in older adults. Arch Phys Med Rehabil 2000;81:960-5. Objective: To examine the effects of a 3-month low-intensity exercise program on physical frailty. Design: Randomized clinical trial. Setting: Regional tertiary-care hospital and academic medi- cal center with an outpatient rehabilitation fitness center. Participants: Eighty-four physically frail older adults (mean age, 83 6 4yrs). Intervention: Three-month low-intensity supervised exer- cise (n 5 48) versus unsupervised home-based flexibility activi- ties (n 5 36). Main Outcome Measures: Physical performance test, mea- sures of balance, strength, flexibility, coordination, speed of reaction, peripheral sensation. Results: Significant improvement was made by the exercise group on our primary indicator of frailty, a physical perfor- mance test (PPT) (29 6 4v s 316 4 out of a possible 36 points), as well as many of the risk factors previously identified as contributors to frailty; eg, reductions in flexibility, strength, gait speed, and poor balance. Although the home exercise control group showed increases in range of motion, the improvements in flexibility did not translate into improvements in physical performance capacity as assessed by the PPT. Conclusions: Our results suggest that physical frailty is modifiable with a program of modest activities that can be performed by virtually all older adults. They also indicate that exercise programs consisting primarily of flexibility activities are not likely to reverse or attenuate physical frailty. Although results suggest that frailty is modifiable, it is not likely to be eliminated with exercise, and efforts should be directed toward preventing the condition.
Proteins of Ovarian Cyst Fluid and Serum from Hypothyroid Gonadotrophin-Treated Rats.

SummaryThiouracil feeding increased total protein and gamma globulin in the serum of female rats above that of their euthyroid controls. Ovarian cyst fluid in these gonadotropin treated hypothyroid rats had an electrophoretic protein pattern which simulated the serum and was characterized by an increase in gamma globulin. Total glycoprotein of serum was greater than cyst fluid but total protein to polysaccharide ratio and ratios of respective fractions did not differ. Following injection of S35 DL-methionine, serum reached peak specific activity in 4 hours; however, cyst fluid activity, negligible for 12 hours, did not reach that of serum until 24 hours. Increasing specific activity of cyst fluid was not coincident with a drop in activity of ovarian residue. Thus these data suggest that protein portion of cyst fluid may be of plasma origin.
Ergonomics of UAV/UCAV Mission Success: Considerations for Data Link, Control, and Display Issues

The United States Armed Forces are turning to Unmanned Aerial Vehicles (UAVs), and their combat-modified counterparts (UCAVs), to support human pilots and improve electronic surveillance and weapon...
New Species of Bretzia (Cervidae; Artiodactyla) from the Latest Pleistocene or Earliest Holocene of Nebraska and South Dakota

A new species of Bretzia is described from eastcentral Nebraska and southeastern South Dakota. Both localities in the Great Plains are latest Pleistocene or earliest Holocene in age. Bretzia is previously known only from Blancan-aged (Pliocene) sediments in Washington and California. New specimens of Bretzia described here extend both the temporal and geographic range of this rare cervid.
Influence of nonequilibrium radiation on heating of an ablating Jovian entry probe

The influence of non-local thermodynamic equilibrium (NLTE) radiative transfer on the entire shock-layer flow phenomena around a Jovian entry body is investigated. The flow in the shock layer is assumed to be viscous, axisymmetric, laminar, and in chemical equilibrium. The entry body considered is a 35-deg hyperboloid and the results have been obtained for the peak heating entry conditions. The results indicate that the radiative heating of the entry body is significantly higher under NLTE conditions.
A combinatory logic approach to higher-order E -unification

Let E be a first-order equational theory. A translation of higher-order E-unification problems into a combinatory logic framework is presented and justified. The case in which E admits presentation as a convergent term rewriting system is treated in detail: in this situation, a modification of ordinary narrowing is shown to be a complete method for enumerating higher-order E-unifiers. In fact, we treat a more general problem, in which the types of terms contain type variables.
The Usable Past, the Comfortable Past, and the Civic Past: Memory in Contemporary America

"What is importantfor us ? " asked cultural critic Van Wyck Brooks in his influential 1918 essay, "On Creating a Usable Past": "What, out of all the multifarious achievements and impulses and desires of the American literary mind, ought we to elect to remember?" (1993:225, emphasis in original). Brooks was concerned with his country's literary history, but his desire to approach the past "from the point of view not of the successful fact but of the creative impulse" was shared by many Progressive-era intellectuals who sought to mobilize American memory as a resource for a more democratic future (Brooks 1993:225). To think of the American past as "usable," as opposed to a dry collection of facts or a completed tradition deserving mute reverence, was to take an essentially pragmatic approach to the study of history. "For the spiritual past has no objective reality," Brooks asserted; "it yields only what we are able to look for in it" (1993:220). The past would become "usable" when it allowed Americans to pry open spaces in the present for future innovation. Such aspirations marked the approach taken to the past by at least two generations of liberal and radical intellectual-activists. Charles and Mary Beard's magisterial Rise of American Civilization (1927) and the multiple editions of The Growth of the American Republic (1930) by Samuel Eliot Morison and Henry Steele Commager offered a "usable" metanarrative for confident progressives and
Physical activity and quality of life in older adults: influence of health status and self-efficacy.

Background: Physical activity has been positively linked to quality of life (QOL) in older adults. Measures of health status and global well-being represent common methods of assessing QOL outcomes, yet little has been done to determine the nature of the relationship of these outcomes with physical activity.Purpose: We examined the roles played by physical activity, health status, and self-efficacy in global QOL (satisfaction with life) in a sample of older Black and White women.Method: Participants (N = 249, M age = 68.12 years) completed multiple indicators of physical activity, self-efficacy, health status, and QOL at baseline of a 24-month prospective trial. Structural equation modeling examined the fit of 3 models of the physical activity and QOL relationship.Results: Analyses indicated that relationships between physical activity and QOL, self-efficacy and QOL were all indirect. Specifically, physical activity influenced self-efficacy and QOL through physical and mental health status, which in turn influenced global QOL.Conclusions: Our findings support a social cognitives model of physical activity’s relationship with QOL. Subsequent tests of hypothesized relationships across time are recommended.
Functional interaction and partial homology between human immunodeficiency virus and neuroleukin

Dementia is common in patients with AIDS, but the mechanism by which the human immunodeficiency virus type 1 (HIV-1) causes the neurological impairment is unknown. In this study the possibility that an antigen of HIV-1 suppresses neuronal responses to neurotrophic factors was examined. Both HIV-1 and a related retrovirus, simian immunodeficiency virus (SIV), inhibited the growth of sensory neurons from chick dorsal root ganglia in medium containing neuroleukin (NLK) but not in medium containing nerve growth factor. An unrelated type D retrovirus, simian acquired immunodeficiency syndrome virus, did not affect the growth of neurons in the presence of either neurotrophic factor. The inhibition by HIV-1 of neuron growth in the presence of NLK was found to be due to the gp120 envelope glycoprotein. Regions of sequence homology between gp120 and NLK may account for this inhibitory property of gp120 and functional interactions between gp120 and NLK may be important in the pathogenesis of the AIDS dementia complex.
Spontaneous crossed phrenic activity in the neonatal respiratory network.

Abstract Hemisection of the cervical spinal cord causes paralysis of the ipsilateral hemidiaphragm in adult rats. Activation of a latent crossed phrenic motor pathway can restore diaphragmatic function, although structural changes take place before the pathway can be activated. Since mechanisms are employed to eliminate non-functional projections during development, we predicted that this latent neural pathway might be active during development. Therefore, we examined the effect of spinal hemisection (C2) on respiratory-like activity bilaterally using the brainstem–spinal cord preparation from neonatal rats (0–4 days). Spontaneous crossed phrenic activity (respiratory-like activity recorded from the ipsilateral C4 or C5 ventral roots following C2 hemisection) was observed in an age-dependent manner; younger preparations exhibited more than older preparations. Increasing drive (increasing [K+] or superfusion of theophylline) either increased or induced crossed phrenic activity. Hemisection caused no change in the frequency, the burst area, duration or peak amplitude contralateral to hemisection. Unlike adult rats, this study shows that crossed phrenic activity is present in the in vitro respiratory network of neonatal rats suggesting that a crossed neural pathway may be functionally active in neonates.
Measurement of bow tie profiles in CT scanners using a real‐time dosimeter

Purpose: Several areas of computed tomography (CT) research require knowledge about the intensity profile of the x-ray fan beam that is introduced by a bow tie filter. This information is considered proprietary by CT manufacturers, so noninvasive measurement methods are required. One method using real-time dosimeters has been proposed in the literature. A commercially available dosimeter was used to apply that method, and analysis techniques were developed to extract fan beam profiles from measurements. Methods: A real-time ion chamber was placed near the periphery of an empty CT gantry and the dose rate versus time waveform was recorded as the x-ray source rotated about the isocenter. In contrast to previously proposed analysis methods that assumed a pointlike detector, the finite-size ion chamber received varying amounts of coverage by the collimated x-ray beam during rotation, precluding a simple relationship between the source intensity as a function of fan beam angle and measured intensity. A two-parameter model for measurement intensity was developed that included both effective collimation width and source-to-detector distance, which then was iteratively solved to minimize the error between duplicate measurements at corresponding fan beam angles, allowing determination of the fan beam profile from measured dose-rate waveforms. Measurements were performed on five different scanner systems while varying parameters such as collimation, kVp, and bow tie filters. On one system, direct measurements of the bow tie profile were collected for comparison with the real-time dosimeter technique. Results: The data analysis method for a finite-size detector was found to produce a fan beam profile estimate with a relative error between duplicate measurement intensities of <5%. It was robust over a wide range of collimation widths (e.g., 1–40 mm), producing fan beam profiles that agreed with a relative error of 1%–5%. Comparison with a direct measurement technique on one system produced agreement with a relative error of 2%–6%. Fan beam profiles were found to differ for different filter types on a given system and between different vendors. Conclusions: A commercially available real-time dosimeter probe was found to be a convenient and accurate instrument for measuring fan beam profiles. An analysis method was developed that could handle a wide range of collimation widths by explicitly considering the finite width of the ion chamber. Relative errors in the profiles were found to be less than 5%. Measurements of five different clinical scanners demonstrate the variation in bow tie designs, indicating that generic bow tie models will not be adequate for CT system research.
Liquid crystalline states for two-dimensional electrons in strong magnetic fields

Based on the Kosterlitz-Thouless-Halperin-Nelson-Young theory of two-dimensional melting and the analogy between Laughlin states and the two-dimensional one-component plasma, we investigate the possibility of liquid crystalline states in a single Landau level (LL). We introduce many-body trial wave functions that are translationally invariant but possess twofold (i.e., nematic), fourfold (tetratic), or sixfold (hexatic) broken rotational symmetry at respective filling factors v= 1/3, 1/5, and 1/7 of the valence LL. We find that the above liquid crystalline states exhibit a soft charge-density wave (CDW) which underlies the translationally invariant state but which is destroyed by quantum fluctuations. By means of Monte Carlo simulations, we determine that, for a considerable variety of interaction potentials, the anisotropic states are energetically unfavorable for the lowest and first excited LL's (with index L=0,1), whereas the nematic is favorable at the second excited LL (L=2).
Reducing within-subject variation in chewing cycle kinematics--a statistical approach.

Summary Objectives: High levels of within-subject variability have limited the use of chewing cycle kinematics in the experimental and clinical context. The purpose of this study was to validate a new strategy for reducing within-subject variability in chewing cycle kinematics, based on the 10 most representative cycles from a chewing sequence. Methods: This prospective study included 25 young subjects, with normal class I occlusions. An optoelectronic recording system was used to track chin movements of subjects chewing gum (2.5 g). Computer programs provided estimates for duration and movement as well as the 3D coordinates of the chin point. The total output files were further processed for selection of 10 representative cycles based on standard scores for total duration, excursive ranges in the lateral, vertical and antero-posterior directions. Multilevel modelling procedures were used to test for significant differences. Results: There were no significant differences in cycle duration or excursions between the estimates for all cycles versus the 10 most representative cycles. Cycle shapes were very similar. There were no statistically significant differences in between-subject variances. All within-subject variances were smaller when using data from the 10 most representative cycles. The reduction of variance was approximately 33% for total duration and 75% for total 3D excursion. Conclusions: The results validate the pre-processing strategy that selects the 10 most representative cycles from a sequence without altering cycle duration, excursions or shape or affecting between-subject variation but reducing within-subject variation substantially.
Over 100 years of environmental change recorded by foraminifers and sediments in Mobile Bay, Alabama, Gulf of Mexico, USA

Abstract The marine microfauna of Mobile Bay has been profoundly influenced by the development and expansion of the primary shipping channel over the last ∼100 years. Foraminifers and sediments from seven box cores with excess lead-210 chronology document that channel dredging and spoil disposal have altered circulation, reduced estuarine mixing, changed sedimentation patterns, and caused a faunal turnover within the bay. Beginning in the late 1800s, changes in estuarine mixing allowed for greater low-pH freshwater influence in the bay, and ultimately began environmental changes that resulted in the loss of calcareous foraminifers. By the early 1900s, box cores throughout Mobile Bay record a ∼100-year trend of increasing calcareous test dissolution that continues to the present. Since the completion of the current shipping channel in the 1950s, restricted tidal flushing and increased terrestrial organic matter, documented by carbon-to-nitrogen ratios, stimulated an increase in agglutinated foraminiferal densities. However, in deeper areas of the bay, hypoxic water has negatively impacted the marine microfauna. Comparisons of the present-day foraminiferal assemblage with foraminifers collected in the early 1970s indicate that the continued biologic loss of calcareous foraminifers in the bay has allowed the introduction of a new agglutinated foraminiferal species into the bay.
TH‐C‐BRB‐07: Treatment Planning with Multiple Spot Sizes to Improve Delivery Efficiency in Intensity Modulated Proton Therapy

Purpose: Intensity modulated proton therapy (IMPT) has the potential to deliver highly conformal dose distributions to target volumes via the superposition of a large number of independently weighted proton pencil beam spots. While smaller proton spots offer superior dose conformity, the increase in treatment time can be significant. The purpose of this study is to develop treatment planning strategies for IMPT that employ proton spots of different sizes, and evaluate the potential reduction in total number of spots and/or improvement in dose conformity given the same treatment time. Methods: Two patient cases (prostate and lung) were analyzed by comparing three spot scanning strategies. Plans A and B use uniform spot sizes (standard deviation of the Gaussian profile) of 3mm and 6mm, respectively. Plan C uses a combination of 3mm and 9mm spots, placed close to the target surface and in the target center, respectively. Slight overlap between the two spot grids was allowed to provide adequate target coverage. The spot spacing was chosen to ensure uniform dose coverage to the target. Treatment plans were created to minimize dose to all normal structures while maintaining similar dose uniformity within the target. Results: Target uniformity was similar for all planning techniques. Plan C achieved nearly the same conformity as plan A, but resulted in spot reductions of 58% and 71% for the prostate and lung cases respectively. Plan B required about the same number of spots as Plan A; however, the D20% to normal tissues near the target increased by 59.6% and 25.6% for the two cases compared with plan C. Conclusions: Combining proton spots of various sizes in IMPT treatment planning allows for the same plan quality as with only using smaller spots. Depending on the target volume, up to a 70% reduction of number of spots can be achieved.
What is the Role of Third Generation Regimens for Initial Therapy of Non-Hodgkin's Lymphomas?

The advances in therapy for aggressive non-Hodgkin's lymphoma have improved the long-term outlook for patients with this disease. However, many questions still remain such as: which combination chemotherapy protocol is the best? Is is necessary to use a third generation regimen, or is CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone) adequate? And finally is the extent of dose intensity that can be achieved with conventional therapy adequate in poor prognosis patients?Although several smaller comparative trials have been done, the four arm trial currently being performed by the South West Oncology Group (SWOG) will represent the largest trial designed to address this issue. One best protocol has not yet been identified as being superior to others for the therapy of patients with aggressive non-Hodgkin's lymphomas. However, certain subsets of patients may benefit from specific protocols. This information can hopefully be gleaned from subset analysis of the SWOG study in the future.At the present t...
Biological Agents for Controlling Excessive Scarring

The potential of various biological agents to reduce or prevent excessive scar formation has now been evaluated in numerous in-vitro studies, experimental animal models and preliminary clinical trials, in some cases with particularly promising results. Perhaps prominent among this group of biological agents, and, to some degree, possibly representing marketed compounds already being used ‘off label’ to manage excessive scarring, are the tumor necrosis factor alpha antagonist etanercept, and immune-response modifiers such as IFNα2b and imiquimod. Additional assessment of these novel agents is now justified with a view to reducing or preventing hypertrophic scars, keloid scars and the recurrence of post-excision keloid lesions.
Students With Intellectual Disabilities: Predictors of Transition Outcomes

This study examined the outcomes of 409 students with mental retardation or multiple disabilities from 177 school districts in a Great Lakes state. These students with intellectual disabilities wer...
High-Temperature Oxidation Behavior of Iridium-Rhenium Alloys

The life-limiting mechanism for radiation-cooled rockets made from iridium-coated rhenium (Ir/Re) is the diffusion of Re into the Ir layer and the subsequent oxidation of the resulting Ir-Re alloy from the inner surface. In a previous study, a life model for Ir/Re rockets was developed. It incorporated Ir-Re diffusion and oxidation data to predict chamber lifetimes as a function of temperature and oxygen partial pressure. Oxidation testing at 1540 deg C suggested that a 20-wt percent Re concentration at the inner wall surface should be established as the failure criterion. The present study was performed to better define Ir-oxidation behavior as a function of Re concentration and to supplement the data base for the life model. Samples ranging from pure Ir to Ir-40 wt percent Re (Ir-40Re) were tested at 1500 deg C, in two different oxygen environments. There were indications that the oxidation rate of the Ir-Re alloy increased significantly when it went from a single-phase solid solution to a two-phase mixture, as was suggested in previous work. However, because of testing anomalies in this study, there were not enough dependable oxidation data to definitively raise the Ir/Re rocket failure criterion from 20-wt percent Re to a Re concentration corresponding to entry into the two-phase region.
Birefringent Dispersion and the Nuclear Quadrupole Interaction

This paper is an addendum to a paper by the author which presented a relation between the gradient of the electric field at the nucleus and dipole matrix elements. A scheme is suggested to take advantage of the result.
Spline fusion: A continuous-time representation for visual-inertial fusion with application to rolling shutter cameras

This paper describes a general continuous-time framework for visual-inertial simultaneous localization and mapping and calibration. We show how to use a spline parameterization that closely matches the torque-minimal motion of the sensor. Compared to traditional discrete-time solutions, the continuous-time formulation is particularly useful for solving problems with high-frame rate sensors and multiple unsynchronized devices. We demonstrate the applicability of the method for multi-sensor visual-inertial SLAM and calibration by accurately establishing the relative pose and internal parameters of multiple unsynchronized devices. We also show the advantages of the approach through evaluation and uniform treatment of both global and rolling shutter cameras within visual and visual-inertial SLAM systems.
The enhancement of heat transfer by waves in stratified gas-liquid flow

Abstract An experimental investigation of heat transfer from a flat plate to horizontal cocurrent airwater flow has been carried out to assess the effects of the different flow regimes on the effectiveness of the heat transfer. The results for smooth liquid film flow and two-dimensional wavy flow of the liquid phase are shown to agree with the theoretical analysis of heat transfer to smooth films. Three-dimensional waves and roll waves are shown to increase the Nusselt number (compared with smooth films) by more than 100 per cent. By using a surface-active agent to stabilize the flow direct comparison between wavy flow heat transfer and smooth flow heat transfer is obtained. At sufficiently low gas phase Reynolds numbers and at sufficiently high wall heat fluxes Rayleigh-like instability due to buoyant forces is shown to occur.
Evaluation of equivalent vision technologies for supersonic aircraft operations

Twenty-four air transport-rated pilots participated as subjects in a fixed-based simulation experiment to evaluate the use of Synthetic/Enhanced Vision (S/EV) and eXternal Vision System (XVS) technologies as enabling technologies for future all-weather operations. Three head-up flight display concepts were evaluated — a monochromatic, collimated Head-up Display (HUD) and a color, non-collimated XVS display with a field-of-view (FOV) equal to and also, one significantly larger than the collimated HUD. Approach, landing, departure, and surface operations were conducted. Additionally, the apparent angle-of-attack (AOA) was varied (high/low) to investigate the vertical field-of-view display requirements and peripheral, side window visibility was experimentally varied. The data showed that lateral approach tracking performance and lateral landing position were excellent regardless of the display type and AOA condition being evaluated or whether or not there were peripheral cues in the side windows. Longitudinal touchdown and glideslope tracking were affected by the display concepts. Larger FOV display concepts showed improved longitudinal touchdown control, superior glideslope tracking, significant situation awareness improvements and workload reductions compared to smaller FOV display concepts.
Academic libraries in the age of MOOCs

Purpose – The article aims to report on the current development of Massive Open Online Courses (MOOCs), explore the strengths and weaknesses of MOOCs, and reflect on the possible relationships between academic libraries and MOOCs. Design/methodology/approach – The paper is based on a mix of literature review (mostly current news) and personal observations. The author discusses the unique characteristics of MOOCs, speculates on the benefits of MOOCs on higher education, and explores the impact of MOOCs on academic libraries and how librarians can respond to it. Findings – MOOCs create global learning communities that benefit both students and universities, and generate unique challenges and opportunities for academic libraries. It is recommended that librarians stay informed of the latest developments and get involved in the MOOC movement on an institutional as well as personal level. Research limitations/implications – Further research needs to be done to evaluate the efficacy of MOOCs (especially in the non‐STEM areas), to explore best practices in instruction design and pedagogy, and to rethink on strategic positioning of traditional universities vis‐a‐vis MOOCs. Practical implications – The author speculates on a possible “iTunization of information” and how that might impact academic libraries as well as the open access movement. The author also calls for academic libraries to be fully engaged in the discussion and action on their own campus related to MOOCs, and to support individual librarians' exploration of MOOCs. Originality/value – This article is based on the author's personal experience as a MOOC student and her opinions and speculations on issues related to MOOCs. The article also explores the relationship between MOOCs and academic libraries, which has not been extensively discussed in the library literature.