cssi/SciSciGPT-SciSciNet huggingface dataset:
Design and Simulation of a T-Vane Relativistic Inverted Magnetron

A design for a high-power relativistic inverted magnetron oscillator (IMO) is presented and modeled numerically using the massively parallel electromagnetic particle-in-cell code, improved concurrent electromagnetic particle in cell (ICEPIC). The inverted magnetron presented here is designed to operate in the $L$ -band for magnetic fields ranging from 0.07 to 0.1 T with voltages ranging from ~250 to 480 kV. Simulations in that voltage/magnetic field range demonstrate that the inverted magnetron is capable of fast startup, $\pi $ -mode dominance with little-to-no mode competition, as well as high output power, exceeding 2.5 GW at the high end of voltages examined. End-loss current, a common source of energy loss in relativistic magnetrons, is not present for this IMO design. The IMO radiates RF energy axially through the use of a novel dual-ring radiator that excites the TM01 mode in the downstream waveguide. This approach yields nominal RF output power efficiencies near 20%. ICEPIC simulations predict that the above features combined with the IMO’s stable, robust, and reliable performance in the desired mode over a large voltage range yield a class of high-power microwave source notable for its inverted geometry and T-vane slow-wave structure.
Chemotherapeutic Drug‐Conjugated Microbeads Demonstrate Preferential Binding to Methylated Plasmid DNA

Plasmid DNA (pDNA) is an attractive therapeutic biomolecule in several diseases including cancer, AIDS, cystic fibrosis, Parkinson's disease, and Alzheimer's disease. Increasing demand for plasmid DNA as a therapeutic biomolecule for transgene expression or vaccine applications necessitate novel approaches to bioprocessing. The synthesis, characterization and evaluation of aminoglycoside-derived hydrogel microbeads (Amikabeads) for pDNA binding is described previously. Here, the generation and evaluation of novel chemotherapeutic drug-conjugated microbeads for application in pDNA binding and recovery is described. Chemotherapeutic drug-conjugated Amikabeads demonstrate higher binding of methylated pDNA compared to unmethylated pDNA in presence of high salt concentrations. Desorption of plasmids from drug-conjugated microbeads is facilitated by the use of organic modifiers. The observed differences in binding methylated versus unmethylated DNA can make drug-conjugated microbeads useful in diagnostic as well as therapeutic applications. These results demonstrate that anti-cancer drugs represent a diverse set of ligands that may be exploited for molecular engineering of novel DNA binding materials for applications in delivery, diagnostics, and biomanufacturing.
The Therapist Personal Reaction Questionnaire: A Cluster Analysis.

Analyses of the 15-item Therapist Personal Reaction Questionnaire (TPRQ) produced 2 clusters—the first related to counselor feelings toward the client, and the second related to counselor feelings ...
Options for Revascularization: Artery Versus Vein : Technical Considerations

Vascular grafts, as either interpositional conduits or bypass grafts, can be used for revascularization procedures in the upper extremity. Vein grafts are more readily available and can be easier to harvest. Arterial grafts may provide superior patency rates compared with vein grafts. Arterial grafts can be located and harvested with consistent and reliable anatomy throughout the body.
Neutron Scattering in 239Pu from 0.2 to 1.0 MeV

Neutron elastic and inelastic scattering in 239Pu has been studied via the time-of-flight technique. Neutrons were produced via the 7Li(p,n)7Be reaction at the University of Lowell 5.5 MV Van de Graaff Accelerator Laboratory. An angular distribution was measured at 570 keV for two level groups, ground plus first excited state and second plus third excited state. The scattering sample was a circular disk of 3.5-cm diameter and 0.2-cm thickness containing 28.7 g of plutonium. Extensive modifications were made to our accelerator-target-sample-detector configuration in order to accommodate the small scatterer. Elastic scattering from a vanadium scatterer provided line shapes for yield extraction from the time-of-flight spectra. Results are compared to ENDF/B-VI.
Immunologic abnormalities in HIV infection.

A variety of immunologic abnormalities have been reported in human immunodeficiency virus (HIV) infection, the most characteristic being a progressive decline in the number and function of circulating CD4 + T lymphocytes. Other defects in the immune response have been described, including abnormalities in the number and function of CD8 + T lymphocytes, polyclonal B-cell activation, defective soluble antigen recognition, decreased cytotoxicity, abnormal monocyte/macrophage function, and a number of serologic abnormalities. HIV infection of cells other than CD4 + T lymphocytes may provide a reservoir for the propagation of virus. Although most HIV-infected md1v1duals develop a humoral immune response to HIV, and although cellular immune mechanisms directed toward HIV have been described in some patients, such responses are generally ineffective in preventing progression of disease. Further elucidation of the nature of these defects will provide the basis for the development of better therapeutic strategies.
A comparative study of topology design approaches for HPC interconnects

The recent interconnect topology designs for High Performance Computing (HPC) systems have followed two directions, one characterized by low diameter and the other by high path diversity. The low diameter design focuses on building large networks with small diameters, guaranteeing one short path between each pair of nodes. Examples include Slim Fly and Dragonfly. The high path diversity design takes into account not only other topological metrics such as diameter but also path diversity between pairs of nodes. Examples include fat tree, Random Regular Graph (RRG) and Generalized De Bruin Graph (GDBG). Topologies designed from these two approaches have distinct features and require very different routing schemes to exploit the network capacity. In this work, we study the performance-related topological features of representative topologies of the two design approaches, including Slim Fly, Dragonfly, RRG, and GDBG, and compare HPC application performance on these topologies with a set of routing schemes. The study uncovers new knowledge about the topologies designed by these two approaches. Findings of the study include (1) the load balance routing technique designed for low diameter topologies, known as the Universal Globally Adaptive Load-balanced routing (UGAL), can be effectively adapted for the high path diversity topologies, and (2) high path diversity topologies in general achieve higher performance than low diameter topologies for networks built by a similar number of the same type of switches.
A Low-Temperature Materials Research Program for Magnetic Fusion Energy

Demonstration models of fusion power plants using a deuterium—tritium cycle are proposed for operation by the end of this century. One of the most promising approaches to achieving this goal uses magnetic confinement of the reacting plasma. Economic considerations lead to the conclusion that the magnetic fields required for confinement must be produced by very large superconducting magnets. Furthermore, in the tokamak devices, a number of these large coils will be required to produce time-varying magnetic fields. The production of these large magnets will require a significant extension of existing cryogenic materials technology, as well as the solution of new problems, primarily associated with the large neutron fluence which results from the D-T reaction. The ERDA-supported program described here is an attempt by NBS and its contractors to develop a research program for solving anticipated materials problems to facilitate magnet development. The completed portion of the program is a detailed survey [1] of published designs, which evaluates the present materials choices, determines some alternatives, and proposes a comprehensive five-year research program on magnet materials. The first year of actual research began during 1977. The projects and their goals for 1977 and 1978 are presented. This program is modeled after the very successful one conducted for ARPA on materials for superconducting machinery [2]. In both programs, the active collaboration of researchers, designers, users, and manufacturers has been enlisted to determine the best existing material for a given task, the development of new materials, and the establishment of a definitive low-temperature data base adequate for the design of dependable devices.
Direct Numerical Simulation Database for Supersonic and Hypersonic Turbulent Boundary Layers

In this paper, we present a direct numerical simulation database of high-speed zero-pressure-gradient turbulent boundary layers developing spatially over a flat plate with nominal freestream Mach number ranging from 2.5 to 14 and wall-to-recovery temperature ranging from 0.18 to 1.0. The flow conditions of the DNS are representative of the operational conditions of the Purdue Mach 6 quiet tunnel, the Sandia Hypersonic Wind Tunnel at Mach 8, and the AEDC Hypervelocity Tunnel No. 9 at Mach 14. The DNS database is used to gauge the performance of compressibility transformations, including the classical Morkovin's scaling and strong Reynolds analogy as well as the newly proposed mean velocity and temperature scalings that explicitly account for wall heat flux. Several insights into the effect of direct compressibility are gained by inspecting the thermodynamic fluctuations and the Reynolds stress budget terms. Precomputed flow statistics, including Reynolds stresses and their budgets, will be available at the website of the NASA Langley Turbulence Modeling Resource, allowing other investigators to query any property of interest.
The effectiveness of antiviral agents with broad-spectrum activity against chikungunya virus varies between host cell lines:

Chikungunya virus (CHIKV) is a mosquito-borne virus that has recently emerged in the Western Hemisphere. Approved antiviral therapies or vaccines for the treatment or prevention of CHIKV infections...
A 10 year retrospective review of fine needle aspiration cytology of cystic lesions of the breast with emphasis on papillary cystic lesions.

Background Fine needle aspiration cytology (FNA) is a simple, safe, cost effective, and accurate method for diagnosis of cystic lesions of the breast. Our study aims to correlate FNA cytology of cystic lesions of the breast with the histologic diagnosis. Methods During a period of 10 years (2007-2017), 314 cases of breast cystic lesions were retrieved from a total 1073 cases of breast FNAs. Of these, 78 cases from 77 patients (mean age = 54.6, female: male = 76:1) with simultaneous FNA and core needle biopsy (CNB) and/or excision specimen were reviewed. The FNA cytology reports were correlated with the histology results of CNB (n = 72) and breast excision (n = 20). Results Overall, 73 of 78 (93.6%) FNA cases were concordant with CNB and/or excision results. Fifty-five benign FNAs were all concordant with histology and reported as benign (negative predictive value = 100%). The positive predictive value of FNA with a malignant diagnosis was 100%, 71.4% for a suspicious diagnosis, and 33.3% for atypical cytologic diagnosis. Two of six papillary lesions were discordant with the concurrent CNB, but the FNA results were concordant with the final histology on excision. Conclusions FNA allows accurate diagnosis of benign cystic lesions. FNA also plays a prominent role in evaluating cystic papillary lesions of the breast and helps to prevent false negative results on the simultaneous CNB. It is essential that FNA and CNB diagnoses be used in combination to make the correct diagnosis and for clinical management.
Letter to The Editor: Rebuttal to “Comments to the paper, Variability of absorption heat pump efficiency for domestic water heating and space heating based on time-weighted bin analysis”

Abstract This rebuttal in the form of a letter to the Editor is prepared by the corresponding author of the paper, “Variability of absorption heat pump efficiency for domestic water heating and space heating based on time-weighted bin analysis, Applied Thermal Engineering, Volume 130, 5 February 2018, 515–527. https://orproxy.lib.utk.edu:2113/10.1016/j.applthermaleng.2017.10.142” in response to the “concerns“ sent to the Editor by Dr. Chris Keinath and Mr. Michael Garrabrant of Stone Mountain Technologies, Inc., (SMTI) Johnson City, TN.
Exploring the Role of Ubiquitination in Progesterone Receptor Transcriptional Activation and Turnover in Breast Cancer Cells

Abstract : Progesterone Receptors (PR) play important roles in both normal breast development and in the development and progression of breast cancers. PR action contributes to cell growth and survival in the presence of progestins and/or growth factors. The growth factor inputs can create receptors with increased transcription in response to lower concentrations of progestins, or receptors hypersensitive to ligand. Post-translational modifications such as ubiquitination and SUMOylation may be mediating these effects. The goal of these studies is to elucidate the functional consequences of the post-translational modifications, specifically, phosphorylationubiquitination and SUMOylation on PR, and to determine the temporal and functional relationship between these modifications. To accomplish this goal mutants of various phosphorylation sites, conjugation sites and consensus sequences have been generated to create receptors deficient in one or more of these modifications. Our preliminary data suggests that S294A PR-B has increased sumoylation relative to wt PR-B, whereas S294A PR-B is unable to be ubiquitinated. Phosphorylation may be differentially regulating these modifications. Transcription reporter assays with S294 phosphomimic mutant PR-B display heightened transcription and the mutant deficient in sumoylation indicate SUMO is a negative regulator of PR transcriptional activity. Phosphorylation of PR by growth factor pathways differentially regulates ubiquitination and SUMOylation of the receptor mediating changes in hormone responsiveness of breast caner.
AttentivU: Designing EEG and EOG Compatible Glasses for Physiological Sensing and Feedback in the Car

Several research projects have recently explored the use of physiological sensors such as electroencephalography (EEG) or electrooculography (EOG) to measure the engagement and vigilance of a user in context of car driving. However, these systems still suffer from limitations such as an absence of a socially acceptable form-factor and use of impractical, gel-based electrodes. We present AttentivU, a device using both EEG and EOG for real-time monitoring of physiological data. The device is designed as a socially acceptable pair of glasses and employs silver electrodes. It also supports real-time delivery of feedback in the form of an auditory signal via a bone conduction speaker embedded in the glasses. A detailed description of the hardware design and proof of concept prototype is provided, as well as preliminary data collected from 20 users performing a driving task in a simulator in order to evaluate the signal quality of the physiological data.
In Pursuit of Consonance: Science and Religion in Modern Works of tafsīr

One of the most important types of scholarly literature to highlight the contentious debate on the relationship between Islam and modern science has been modern commentary on the Qur'an (tafsīr). T...
Fighting with the Fourth Estate: A Framework of Organization-Media Rivalry for Narrative Control

In this article, I develop a theoretical framework to explain rivalry for narrative control between transgressing organizations and media outlets. I do so by integrating and advancing key insights ...
A [White] Cyborg’s Manifesto: the overwhelmingly Western ideology driving technofeminist theory:

‘A Cyborg Manifesto’ is a required reading in many graduate programs to explore technofeminism, transhumanism, and studies of science and technology to explore notions of gender, race, and other mi...
Native Mass Spectrometry Reveals the Simultaneous Binding of Lipids and Zinc to Rhodopsin

Rhodopsin, a prototypical G-protein-coupled receptor, is responsible for scoptic vision at low-light levels. Although rhodopsin's photoactivation cascade is well understood, it remains unclear how lipid and zinc binding to the receptor are coupled. Using native mass spectrometry, we developed a novel data analysis strategy to deconvolve zinc and lipid bound to the proteoforms of rhodopsin and investigated the allosteric interaction between lipids and zinc binding. We discovered that phosphatidylcholine bound to rhodopsin with a greater affinity than phosphatidylserine or phosphatidylethanolamine, and that binding of all lipids was influenced by zinc but with different effects. In contrast, zinc binding was relatively unperturbed by lipids. Overall, these data reveal that lipid binding can be strongly and differentially influenced by metal ions.
Computational Thinking for STEM Teacher Leadership Training at Louisiana State University

We developed and piloted a new course titled Computer Science Teaching Methods (CSM) in the fall semester of 2019. This course was based on materials developed from a previous program that trained high school teachers in computational thinking and programming through LSU's Cain Center. Pedagogical content knowledge informed the design of this course. Also, data gathered from teacher and instructor interaction at multiple sites during the summer STEM professional development program contributed to the courses' design. The CS Methods course targeted undergraduate computer science majors who were considering a career in teaching or who were interested in CS pedagogy. We encountered several challenges recruiting and retaining students and found that computer science students attracted to teaching careers do not fall into the stereotype of most computer science majors. Participation of women was higher than the average undergraduate CS courses. A disconnect appeared between the pedagogical practices promoted for teaching computing at the high school level and those being practiced at the college level. After learning about the 5E pedagogical model for teaching computing, students expressed interest in the potential of using more student-centered instruction, not only for high school instruction, but also for their own college courses. An area of disconnect also emerged in the programming formats, as all the students were comfortable with Java but all were unfamiliar with popular block-based programming platforms, such as Scratch. The transition from the CS curriculum taught in high schools to what follows in college needs to be smoother.
A financial benefit-cost analysis of different community solar approaches in the Northeastern US

Abstract Community solar farms (CSF) have the potential to expand solar access and improve financial viability compared to traditional residential and commercial solar options. The Cook County Community Solar Project created and made publicly available 26 benefit-cost analysis spreadsheets and associated white papers for 15 case study CSF locations in Illinois with proposed panel leasing financial models. We update these spreadsheets to reflect current federal incentives, fix some key errors, and compare the net present value, annual cash flow, return on investment, and simple payback period for all 26 panel leasing financial models; apply the panel leasing model to a Maine-based location; develop and apply to Maine three additional financial models: lease-to-own, panel purchase with developer, and grassroots “true ownership”; and provide a comparative analysis of the effects of federal and state incentives on CSF panel leasing in Maine and Illinois. Illinois panel lease results for subscribers, owners, and hosts, respectively, include net present values ($2019 thousands) of -$127 to $27, $6 to $450, -$490 to $473; return on investment of −53% to 295%, 8% to 117%, −44% to 474%; and simple payback period (years) of 0 to 20, 3.6 to 20, 0 to 20, (with system owner internal rate of return set at 10%). Respective Maine results include: $5 to $9, $4 to $201, $193 to $209; 84% to 262%, 26% to 207%, 116% to 309%; 0 to 8, 1 to 14, 0 to 3. Holding all else equal, higher electricity prices, a lower labor rate, and a 1:1 net metering bill credit policy yield greater subscriber and host (anchor subscriber) benefits for Maine than Illinois. Although the panel purchase model yields the greatest net present value (NPV) for subscriber and host in the Maine analysis, it yields the lowest developer NPV and requires a large upfront cost to subscribers that may limit participation to those with higher income. Therefore, we recommend the lease-to-own model for the Maine case study site, as it provides positive substantial NPV for all three stakeholder types without large upfront costs for subscribers and with a path to ownership.
Myocardial infarct size and sex-related angiographic differences in myocardial infarction in nonobstructive coronary artery disease.

BACKGROUND Myocardial infarction in nonobstructive coronary artery disease (MINOCA) is a recently described infarct subtype. There are few studies that examine coronary artery disease (CAD) extent, MI size and type, and treatment differences at hospital discharge compared to myocardial infarction in obstructive coronary artery disease (MICAD), or that explore sex-specific MINOCA attributes of coronary anatomy and infarct size. METHODS Our study population consisted of a single tertiary-center of consecutive patients that had coronary angiography for acute MI between 2005 and 2015. The MI type at presentation, MI size and ejection fraction (post-MI), and gender differences between MINOCA patients were examined. RESULT Among 1698 cases with acute MI, 95 had MINOCA (5.6%). MINOCA patients were younger, more often had NSTEMI, lower peak cardiac troponin (cTn) values, and greater ejection fraction than MICAD patients (all P-values <0.005). At hospital discharge, 30-day re-admission rates were similar. MINOCA patients less frequently received optimal medical therapy. When women were analyzed, the 45 women with MINOCA had smaller MIs (P < 0.001) and greater ejection fraction (P = 0.002) than the 358 women with MICAD. Sex comparisons of the 95 MINOCA patients revealed women were older than men (P < 0.001), had lower mean peak cTn values (P < 0.001), greater ejection fraction (P = 0.02), and more single-vessel disease involvement than men (P < 0.0001). CONCLUSION The average MI size is smaller in MINOCA than MICAD patients, and there are sex-related differences in clinical presentation, coronary artery disease extent, and MI size. Re-admission rates are similar and MINOCA patients are less likely to receive guideline recommended medical therapy at discharge.
Electrolyte conditions in lithium-ion batteries in presence of a thermal gradient

Heat release within a Li-ion battery is a significant safety concern. If the temperature rises above a certain threshold, secondary chemical reactions begin with potential thermal runaway outcomes. This work investigates spatially dependent electrolyte conditions in the presence of a thermal gradient to produce an electrolyte-centric thermal runaway model in the absence of passage of electrical current. Li ions, momentum, and thermal flux are the main components of the analysis, which accounts for free convection within the electrolyte. Numerical simulation techniques are used for this purpose. The model shows that hot spots can be found at the interface between the anode and the liquid electrolyte. The temperature trends are in line with previous thermal models for an entire Li-ion cylindrical battery. A thorough comprehension of the transport processes inside the battery contributes to mitigate damage induced due to thermal abuse conditions.
Using a Communication Passport within a Multidisciplinary Genetics Clinic.

Multiple clinic models for Down syndrome exist; one model is the multidisciplinary, specialty clinic, such as the Massachusetts General Hospital Down Syndrome Program (MGH DSP). Methods Intrateam communication was identified as an area for improvement. Our team developed an intervention, the Passport, a paper-based communication tool passed by parents between clinical teams who evaluated the same patients in different locations. Metrics included an electronic survey of parents and clinicians and tracking the frequency of Passport use. The analysis included the use of Statistical Process Control charts and rules. Results The parental suggestions for communication-based interactions improved from 54% (32/60) to 17% (3/18) (P < 0.01). Communication scores within the MGH DSP team and between the team and parents were high at 86% and 96%, respectively. Overall satisfaction with the MGH DSP remained consistently high during our project, with a mean score of 6.49 out of 7. The MGH DSP team members reported communication scores with a mean of 85 out of 100. Conclusions Implementation of a paper Passport tool incorporated parents in the real-time, intraclinic communication between our MGH DSP teams, leading to improved communication suggestions and high marks on the other metrics followed. Such a tool could be useful for other multidisciplinary clinics where team members evaluate the same patients at different locations on the same day.
A Glossary of Terms Used for PLEDs (Periodic Lateralized Epileptiform Discharges) and Related EEG Patterns

ABSTRACT.Since the term periodic lateralized epileptiform discharges (PLEDs) was first coined by Chatrian et dl. in 1964, there has been an evolution of terms used to describe variants of this EEG pattern. This article is an attempt to collect and define various terms used to describe these patterns.
Current-Induced Intermediate State in Superconducting Strips of Lead and Indium

We have investigated the magnetic structure, the electrical resistance, and the electrical noise power spectra in the current-induced intermediate state of superconducting strips of lead and indium. The specimens were microstrips 60–300 µm wide, 0.3–10 µm thick, and 3–6 mm long. The samples were made by vacuum deposition on a glass or fused quartz substrate using starting materials with 99.9999% purity and a tunable mask with two razor blade sections. The samples carried electrical current and voltage leads attached to rather wide sections at both ends of the strip. The experiments were performed in zero applied external magnetic field. Electrical transport currents with an average density up to 106 A/cm2 were applied to the strips. The samples were in direct contact with the liquid helium bath. In order to protect the microstrips against destruction by thermal runaway, a shunt was attached parallel to the sample. The shunt resistance was 3–5 times the normal resistance of the samples at 4.2°K, being at least 1–2 orders of magnitude larger than the current-induced sample resistance for the current range investigated. In the electrical noise power measurements the primary coil of a stepup transformer in the liquid helium bath provided the protective shunt.
Abstract 14049: High-Molecular-Weight Polyethylene Glycol (PEG) Inhibits Myocardial Ischemia-Reperfusion Injury and Improves Ventricular Function and Survival

Cardiac ischemia-reperfusion (I-R) injury remains a significant clinical problem as there are no therapies available to minimize the cell death that can lead to impaired function and heart failure. We have shown that high-molecular-weight PEG (15-20kD) can protect cardiac myocytes in vitro from hypoxia-reoxygenation injury. In this study, we investigated the potential protective effects of PEG in vivo. Adult male rats underwent left thoracotomy and LAD occlusion for 60 minutes followed by either 48 hours (hrs) or 4 weeks (wks) of reperfusion. 1 mL of 10% PEG solution or saline (PBS) control (n=10 per group) was administered intravenously (IV) immediately prior to reperfusion. Fluorescein-labeled PEG was robustly visualized in the myocardium 1 hr after IV delivery. Survival at 4 wks post-I-R was greater in the PEG group: 90% vs. 60% in PBS controls. The PEG group had full recovery of LV ejection fraction at 4 wks vs. 20% decline from baseline in the PBS group (p
Comparative study of optical networks with grid flexibility and traffic grooming

We comparatively investigated among different optical network architectures characterized by grid flexibility and sub-wavelength traffic grooming. Simulation shows that the elastic models are more effective than fixed-grid models in terms of spectrum efficiency, but the trade-off between grooming gain and its additional cost should be considered especially in elastic models.
Interactions of 111In → 111Cd probe atoms on GaAs(111)B reconstructed surfaces measured using perturbed-angular-correlation spectroscopy

We have used 111In → 111Cd perturbed-angular-correlation (PAC) spectroscopy to measure hyperfine interactions at surface sites on GaAs(111)B (As-terminated) surfaces. The (111)B surfaces form two reconstructions, 2 × 2, which is formed under As-rich conditions and is stable below ∼700 K, and √19 × √19R23.4°, which is formed under Ga-rich conditions above this temperature. These nearly-atomically-flat surfaces were grown using molecular beam epitaxy. During each experiment, the 111In probe atoms were effused onto the GaAs surface, and a series of thermal anneals was performed. A laboratory-temperature PAC measurement was made after each anneal. The PAC measurements performed on the 2 × 2 reconstructed surfaces show two well-defined nuclear electric-quadrupole interactions that occur at two inequivalent Ga-sites on the surface. The corresponding electric-field gradients (EFGs) are large and asymmetric: Vzz ≈ 8.6 × 1017V cm−2, and η ≈ 0.47 and Vzz ≈ 16.5 × 1017V cm−2 and η ≈ 0.85; the respective site fractions are ∼50% and ∼30%. The measurements performed on the √19 × √19R23.4° reconstructed surfaces show one well-defined interaction that involved ∼82% of the probes. The corresponding EFG is also large and asymmetric: Vzz ≈ 16.7 × 1017V cm−2 and η ≈ 0.8, and the EFG z-axis is oriented essentially perpendicular to the surface. Annealing experiments were performed to convert one reconstruction to the other and then to reconvert it back to the original reconstruction, e.g., 2 × 2 → √19 × √19R23.4° → 2 × 2.. The PAC measurements that followed each annealing step show the characteristic frequencies for each reconstruction. This result indicates that these probe sites are thermodynamically stable. Additionally, at high annealing temperatures and during these thermal-cycling experiments, a small fraction of the probes appear to diffuse into the bulk crystal. The interpretation of the probe-site assignments does not agree with a model of the √19 × √19R23.4° reconstructed surface developed using scanning tunneling microscopy. These experiments represent the first measurements of group III bonding symmetries on a compound III–V semiconductor surface. The corresponding analysis indicates that these symmetries differ qualitatively from the conventional picture.
Special Issue on Pan American Biofuel and Bioenergy Sustainability

This editorial will introduce a set of seven articles appearing in this Special Issue on Pan American biofuel and bioenergy sustainability. We will discuss the importance of sustainability in biofuel and bioenergy development and rationale for a focus on the Pan American region. These articles are one outcome of a US National Science Foundation-funded project, and we will list the project goal, objectives, and activities. We will also provide short overviews of the articles. The implications of large-scale biofuels and bioenergy production on environmental systems and social conditions are largely unknown. Yet despite this lack of fundamental sustainability knowledge, there is sustained interest in development of biofuels and bioenergy production systems that will concomitantly lead to changes in extant human and natural systems. These changes may be beneficial or detrimental, and may involve: land ownership and management, creation of new employment opportunities, occupational safety, unforeseen transportation and logistical challenges, impacts on water availability and quality, potential competition with food production, among others. The Pan American region is of interest to study for biofuel and bioenergy sustainability because of its dominance in global biofuel production, its large biofuel production capacity because of abundant land area and favorable soils and climate, its possession of a significant fraction of the world’s biodiversity, large agricultural sectors, and rich policy experience. The articles in this Special Issue are organized into two main categories: natural and social sciences; and systems analyses.
Circuit models of PWM DC-DC converters

A systematic method is presented for including parasitic resistances and offset voltage sources of power switches into averaged dynamic large-signal, DC, and small-signal circuit models of PWM converters operating in continuous conduction mode. This method is based on the principle of energy conservation. It is shown that the equivalent circuits can be manipulated, using the reflection rule, to simplify the models. A procedure of modeling the buck converter is detailed. Models of all buck-derived converters have the same structure as that for the buck converter, but expressions for averaged components are different. These expressions are given. A design equation for selecting the value of the filter capacitance is derived, and it is shown that the ripple voltage can be made dependent only on the equivalent series resistance of the filter capacitor. >
Approach to photorealistic halo simulations

A multiple-scattering Monte Carlo model that can produce near-photographic quality images is developed and used to simulate several dramatic halo displays. The model atmosphere contains an absorbing ozone layer plus two clear, molecular air layers with Rayleigh scattering surrounding a cloud layer and an atmospheric boundary layer with aerosol particles subject to Lorentz–Mie scattering. Halos are produced by right hexagonal or pyramidal crystals that reflect and refract according to geometric optics without diffraction, although “junk” crystals with a pronounced forward-scattering peak but no halo peaks may be included to simulate typical, faint halos. Model parameters include ozone height and content, surface and cloud pressure, cloud optical thickness, crystal shapes, orientations and abundances, atmospheric turbidity, aerosol radius, and albedo. Beams for each wavelength are sorted into small bins as halo beams if they have been scattered once only by a single crystal and otherwise as sky beams, which are smoothed and combined with the halo beams to produce images. Multiple scattering generally vitiates halos, but extremely rare halos, such as Kern’s arc, can be produced if a significant fraction of crystals in optically thick clouds have identical shapes and are highly oriented. Albedo is a model by-product with potential value in climate studies.
Sexual and physical abuse in women with fibromyalgia: Association with outpatient health care utilization and pain medication usage

Objective. To evaluate the relationship between sexual and/or physical abuse and health care usage in patients with fibromyalgia (FM) and identify variables that may influence this relationship. Methods. We assessed history of sexuall physical abuse, health care utilization, and medication usage, as well as related variables in 75 women with FM using standardized questionnaires, structured interviews, and laboratory pain perception tasks. Results. Fifty-seven percent of FM patients reported a history of sexuall physical abuse. Compared to non-abused patients, abused patients reported significantly greater utilization of outpatient health care services for problems other than FM and greater use of medications for pain (P ≤ 0.025). Consistent with our expectations, abused patients also were characterized by significantly greater pain, fatigue, functional disability, and stress, as well as by a tendency to label dolorimeter stimuli as painful regardless of their intensities (P ≤ 0.05). Additional analyses suggested that the high frequency of sexuall physical abuse in our patients was associated primarily with seeking health care for chronic pain rather than the FM syndrome itself or genetic factors. Conclusion. There is an association in FM patients between sexuall physical abuse and increased use of outpatient health care services and medications for pain. This association may be influenced by clinical symptoms, functional disability, psychiatric disorders, stress, and abnormal pain perception. The relationships among these variables should be further tested in prospective, population-based studies.
An Analysis of Changes in the Risk of Mortality from Chronic Obstructive Lung Disease, 1968‐1977

Nonlinear hazard models are used to examine temporal trends in the age-specific mortality risks of chronic obstructive lung diseases for the U.S. population. These hazard functions are fit to age-specific mortality rates for 1968 and 1977 for four race/sex groups. Changes in the parameters of these models are used to assess two types of differences in the age pattern of the rates between 1968 and 1977. The first measure of trend in the age-specific mortality rates is the temporal change in the proportionality constant in the function used to model their age variation. By allowing only this proportionality parameter to vary between 1968 and 1977, it is possible to determine an age-constant percentage increase or decrease. The second measure reflects the absolute displacement in terms of years of life of the fitted mortality curves for the two time points. This second index can be interpreted as the acceleration or deceleration of mortality risks over the life span, i.e., the number of years that is needed for mortality rates to achieve the same level as in the comparison group. The analysis showed that the age changes in chronic obstructive lung disease mortality rates differed by race/sex group and for both measures of change over the period. Adjustment of the fitted curves for the effects of individual variability in risk was significant for three of four groups.
On Case Method and Classroom Management

Abstract Teacher educators who seek to help their students become reflective practitioners can themselves engage in reflection on practice. This article is a reflection on the use of case method in teacher education. The author describes her use of case method with one class of secondary student teachers and her efforts to assess and better understand the effects of case method in teacher education. The challenges and possibilities of reflection on practice are discussed through this examination of case method.
Some aspects of adaptation in a polymorphism for breeding colours in the Threespine stickleback (Gasterosteus aculeatus))

Polymorphism in the nuptial colouration of male Threespine sticklebacks (Garterosteus aculeatus L.) was studied. In Lake Wapato in Eastern Washington, approximately 14% of the breeding males develop typical red nuptial colouration while others develop various colours which were grouped into a non-red category. The hypothesis was tested that red males are adaptive in Lake Wapato as a result of sexual selection and differential egg predation. In a series of mate preference tests, females demonstrated a significant preference for red males over non-red males. In a second experiment, using artiticially coloured non-red males, it was shown that the females are responding to the red colouration alone. This evidence suggests that one of the selective pressures maintaining the red morph is sexual selection. In a stomach analysis of male and female sticklebacks collected from a breeding colony it was found that 51 % of the fish examined had stickleback eggs in their stomachs. Both male and female sticklebacks eat a large number of eggs; however, males eat significantly more eggs than females. Eggs were found to be most susceptible to predation during their first four days of development. Given that red ventral colouration has threat value, red males may also be adaptive because of a reduction in egg predation within their territories in contrast to non-red males. One of the selective forces against red males is probably differential predation by trout (Salmo gairdneri). This trout predation has been shown to be extensive in Lake Wapato. The opposing selective forces discussed in this paper cannot maintain the polymorphism; they are only components of fitness of the colour morphs.
Recurrent ovarian carcinoma: is there a place for surgery?

The role of cytoreductive surgery is well established in patients with primary ovarian carcinoma. Minimal residual disease translates to improved response to adjuvant treatment and prolonged survival. For close clinical follow-up, different approaches may be helpful in detecting recurrent disease, including regular physical/pelvic examination, serial CA-125 levels, and imaging studies using computerized tomography, magnetic resonance imaging, or positron emission testing. At recurrence, those patients with a good performance status, a good response to primary therapy, and a macronodular tumor distribution pattern may be candidates for a secondary cytoreductive procedure. Data suggests that secondary cytoreduction is superior to chemotherapy alone in patients who have a significant disease-free interval (6 to 12 months). Survival after secondary cytoreduction is optimized with cytoreduction to microscopic disease, yet there is a recognized risk of surgical morbidity. Therefore, a strong relationship between the gynecologic oncology surgeon and the patient is key to obtaining appropriate informed consent and relaying appropriate outcome expectations.
Alternative and low sulfur fuel options: Boundary lubrication performance and potential problems

Studies of alternative fuels at Penn State include biodiesel, dimethyl ether (DME) and low sulfur diesel fuels. The fuel studies include bench tests, laboratory engine tests and vehicle tests. DME was evaluated in a campus shuttle bus operating on its regular campus route. A 25:75 vol% mixture of DME and diesel fuel was used. Laboratory engine tests of oxygenated fuels, including biodiesel, resulted in significant particulate reductions. However, some alternative fuels exhibit low lubricity. Bench tests comparing friction and wear characteristics of the fuels are described.
Robust Optimization Based Economic Dispatch for Managing System Ramp Requirement

The increasing penetration of renewable generation poses a challenge to the power system operator's task of balancing demand with generation due to the increased inter-temporal variability and uncertainty from renewables. Recently major system operators have been testing approaches to managing inter-temporal ramping requirement. In this paper we propose a robust optimization based economic dispatch model for ensuring adequate system ramp capability. The proposed model is critically assessed with the ramp product which is currently under consideration by several system operators. We conduct theoretical assessment based on a proposed lack-of-ramp probability (LORP) index and numerical assessment using Monte Carlo simulations. It is shown that compared with the recently proposed industry model, the proposed robust formulation of ramp requirement yields more smoothed generation cost variation and is capable of ensuring lower lack of ramp probability.
Adenosine A1 receptors heterodimerize with β1- and β2-adrenergic receptors creating novel receptor complexes with altered G protein coupling and signaling

G protein coupled receptors play crucial roles in mediating cellular responses to external stimuli, and increasing evidence suggests that they function as multiple units comprising homo/heterodimers and hetero-oligomers. Adenosine and β-adrenergic receptors are co-expressed in numerous tissues and mediate important cellular responses to the autocoid adenosine and sympathetic stimulation, respectively. The present study was undertaken to examine whether adenosine A1ARs heterodimerize with β1- and/or β2-adrenergic receptors (β1R and β2R), and whether such interactions lead to functional consequences. Co-immunoprecipitation and co-localization studies with differentially epitope-tagged A1, β1, and β2 receptors transiently co-expressed in HEK-293 cells indicate that A1AR forms constitutive heterodimers with both β1R and β2R. This heterodimerization significantly influenced orthosteric ligand binding affinity of both β1R and β2R without altering ligand binding properties of A1AR. Receptor-mediated ERK1/2 phosphorylation significantly increased in cells expressing A1AR/β1R and A1AR/β2R heteromers. β-Receptor-mediated cAMP production was not altered in A1AR/β1R expressing cells, but was significantly reduced in the A1AR/β2R cells. The inhibitory effect of the A1AR on cAMP production was abrogated in both A1AR/β1R and A1AR/β2R expressing cells in response to the A1AR agonist CCPA. Co-immunoprecipitation studies conducted with human heart tissue lysates indicate that endogenous A1AR, β1R, and β2R also form heterodimers. Taken together, our data suggest that heterodimerization between A1 and β receptors leads to altered receptor pharmacology, functional coupling, and intracellular signaling pathways. Unique and differential receptor cross-talk between these two important receptor families may offer the opportunity to fine-tune crucial signaling responses and development of more specific therapeutic interventions.
Different Aspects and Design Considerations of PLC Based ROADM/WSS

ROADM and WSS are key network elements in intelligent network. PLC plays an essential role in providing either integrated or hybrid solutions. We examine the trade-offs and challenges between monolithically integrated and hybrid systems.
Social constructivism, individual constructivism and the role of computers in mathematics education

Abstract By asking the question: “Can computers do mathematics?” this paper investigates the relationship between computers and views of mathematics from both individual and social constructivist perspectives. Although these two perspectives ask many of the same questions, they frame these questions in quite different ways of viewing the interaction between individual, subject matter, culture, and cultural tools (e.g. computers). I argue that whereas social constructivist are more likely to take the position that computers alter the way we do mathematics, individual constructivists would more likely say that computers changes the mathematics that we do. Individual constructivists, by placing mathematics itself within the actions carried out by an individual, provide a theoretical framework that allows for the richness and diversity of student constructions that can expand our understanding of mathematics beyond the bounds of any one particular culture.
The Distributional Effects of Public Higher Education in New York City

This paper is concerned with determining the effects of public higher education on the distribution of income in New York City. Distributional effects are determined by distributing the current expenditures of New York City and New York State for public higher education according to the percentage distribution of New York City and New York State taxes by income class and the percentage income distribution of students' families. This provides an estimate of the taxes paid by families in each income class to support public higher education, and the direct monetary benefits received by families in each income class from public higher education. Net benefits for each income class are obtained by subtracting total costs from total benefits for each income class. The net benefits from the public higher education system in New York City are positive for each income class below $15,000. There is a redistribution of income from the $15,000 and above income class to all income classes below $15,000. Distributional ...