cssi/SciSciGPT-SciSciNet huggingface dataset:
A machine learning approach to investigate the relationship between shape features and numerically predicted risk of ascending aortic aneurysm

Geometric features of the aorta are linked to patient risk of rupture in the clinical decision to electively repair an ascending aortic aneurysm (AsAA). Previous approaches have focused on relationship between intuitive geometric features (e.g., diameter and curvature) and wall stress. This work investigates the feasibility of a machine learning approach to establish the linkages between shape features and FEA-predicted AsAA rupture risk, and it may serve as a faster surrogate for FEA associated with long simulation time and numerical convergence issues. This method consists of four main steps: (1) constructing a statistical shape model (SSM) from clinical 3D CT images of AsAA patients; (2) generating a dataset of representative aneurysm shapes and obtaining FEA-predicted risk scores defined as systolic pressure divided by rupture pressure (rupture is determined by a threshold criterion); (3) establishing relationship between shape features and risk by using classifiers and regressors; and (4) evaluating such relationship in cross-validation. The results show that SSM parameters can be used as strong shape features to make predictions of risk scores consistent with FEA, which lead to an average risk classification accuracy of 95.58% by using support vector machine and an average regression error of 0.0332 by using support vector regression, while intuitive geometric features have relatively weak performance. Compared to FEA, this machine learning approach is magnitudes faster. In our future studies, material properties and inhomogeneous thickness will be incorporated into the models and learning algorithms, which may lead to a practical system for clinical applications.
Intentional learning: A concept analysis.

Aim To use a concept analysis to determine a clear definition of the term “intentional learning” for use in nursing. Background The term intentional learning has been used for years in educational, business, and even nursing literature. It has been used to denote processes leading to higher order thinking and the ability to use knowledge in new situations; both of which are important skills to develop in nursing students. But the lack of a common, accepted definition of the term makes it difficult for nurse educators to base instruction and learning experiences on or to evaluate its overall effectiveness in educating students for diverse, fast-paced clinical practices. Design and Review Methods A concept analysis following the eight-step method developed by Walker and Avant (2011). Data Sources Empirical and descriptive literature. Results Five defining attributes were identified: (1) self-efficacy for learning, (2) active, effortful, and engaged learning, (3) mastery of goals where learning is the goal, (4) self-directed learning, and (5) self-regulation of learning. Conclusion Through this concept analysis, nursing will have a clear definition of intentional learning. This will enable nurse educators to generate, evaluate, and test learning experiences that promote further development of intentional learning in nursing students. Nurses in practice will also be able to evaluate if the stated benefits are demonstrated and how this impacts patient care and outcomes.
Effects of a chirped bias voltage on ion energy distributions in inductively coupled plasma reactors

The metrics for controlling reactive fluxes to wafers for microelectronics processing are becoming more stringent as feature sizes continue to shrink. Recent strategies for controlling ion energy distributions to the wafer involve using several different frequencies and/or pulsed powers. Although effective, these strategies are often costly or present challenges in impedance matching. With the advent of matching schemes for wide band amplifiers, other strategies to customize ion energy distributions become available. In this paper, we discuss results from a computational investigation of biasing substrates using chirped frequencies in high density, electronegative inductively coupled plasmas. Depending on the frequency range and chirp duration, the resulting ion energy distributions exhibit components sampled from the entire frequency range. However, the chirping process also produces transient shifts in the self-generated dc bias due to the reapportionment of displacement and conduction with frequency to...
Optimizing surgical placement of the HeartWare ventricular assist device in children and adolescents by virtual implantation

Abstract Background In order to safely place adult-size intracorporeal devices into small patients, innovative techniques such as virtual implantation are necessary to assess proper fit. We assessed the hypothesis that virtual implantation of the HeartWare ventricular assist device will facilitate safe placement in patients at or below industry size guidelines. Methods Five patients (ages 3–17 years; BSA 0.67–1.5 m2) with a body surface area at or below the minimum body surface area of ≤ 1.5 m2 as stated in the device instructions for use were identified as potential candidates for HeartWare device underwent virtual implantation. Results Three patients went on to have successful HeartWare device placement based on virtual implantation techniques despite not meeting standard device criteria or standard apical position. Each case description demonstrates the individual benefit of utilizing virtual implantation for HeartWare device placement. Conclusion Pre-operative assessment with virtual implantation successfully predicted and optimized device placement in the pediatric population despite not meeting standard device fit criteria or standard apical position.
Scanning resonator microscopy integrating phase sensitive detection

Scanning resonator microscopy (SRM) is a scanning probe technique that uses a small, optical resonator attached to the end of a conventional atomic force microscopy cantilever to simultaneously measure optical and topography properties of sample surfaces. In SRM, whispering gallery mode (WGM) resonances excited in the attached optical resonator shift in response to changes in surface refractive index (RI), providing a mechanism for mapping RI with high spatial resolution. In our initial report, the SRM tip was excited with a fixed excitation wavelength during sample scanning, which limits the approach. An improved method based on a wavelength modulation coupled with phase sensitive detection is reported here. This results in real-time characterization of WGM spectral shifts while eliminating complications arising from measurements based solely on signal intensity. This improved approach, combined with a modified tip design enabling integration of smaller resonators, is shown to enhance signal-to-noise and lead to sub-100 nm spatial resolution in the SRM optical image. The improved capabilities are demonstrated through measurements on thin dielectric and polymer films.
Correlation matrix renormalization theory for correlated-electron materials with application to the crystalline phases of atomic hydrogen

Developing accurate and computationally efficient methods to calculate the electronic structure and total energy of correlated-electron materials has been a very challenging task in condensed matter physics and materials science. Recently, we have developed a correlation matrix renormalization (CMR) method which does not assume any empirical Coulomb interaction $U$ parameters and does not have double counting problems in the ground-state total energy calculation. The CMR method has been demonstrated to be accurate in describing both the bonding and bond breaking behaviors of molecules. In this study, we extend the CMR method to the treatment of electron correlations in periodic solid systems. Using a linear hydrogen chain as a benchmark system, we show that the results from the CMR method compare very well with those obtained recently by accurate quantum Monte Carlo (QMC) calculations. We also study the equation of states of three-dimensional crystalline phases of atomic hydrogen. We show that the results from the CMR method agree much better with the available QMC data in comparison with those from density functional theory and Hartree-Fock calculations.
Downhole wireless communication using magnetic induction technique

This paper presents a novel method utilizing magnetic induction (MI) for wireless data transmission in oilfield borehole systems. Compared with conventional techniques, MI telemetry can achieve massive data transmission with low cost. Three coil configurations in borehole system are investigated, and most effective one is selected out based on numerical simulations. Through equivalent circuit model analysis, path loss and channel capacity are derived.
Conclusion: Power and Industrial Capitalism, Past and Present

There is a growing interest in historical archaeology to bridge the gap between archaeology and anthropology, and to simultaneously link past and present power relationships engendered by capitalism. Anthropologists and archaeologists working at industrial sites are well positioned to study socioeconomic power and industrial capitalism, whether they approach their work with Marxian, postmodern, feminist, intersectional identity, practice, or other theories. Those working at industrial sites are increasingly interested in doing social archaeology and contributing to other disciplines’ goals of developing global contexts, remembering community heritage, and addressing the significance of identity in laboring communities. Moreover, it has been vividly demonstrated that archaeology is inherently political, and that archaeology can challenge society regarding today’s power relations stemming from historical antecedents. Research at Fayette contributes to these goals, while integrating a variety of theoretical approaches including class, hegemony, biopower, intersectional identities, and noneconomic capital. The goal in combining these diverse ideas is to explore the plurality of power relationships in past contexts of industrial capitalism with reference to the present. The notion of pluralistic power encompasses both productive and oppressive forms of power, and acknowledges that nuanced and multifaceted power relations exist in combination with binary dynamics such as domination and resistance. Those laboring within past and present contexts of industrial capitalism have certainly been oppressed and dominated in various contexts, and we should strive to illuminate those stories. At the same time, we should also highlight their skillful improvisation in everyday practices and the creative strategies they employed to achieve significant goals. These struggles involved many different manifestations of power.
A Deadline and Budget Constrained Cost and Time Optimization Algorithm for Cloud Computing

Cloud computing is a rapidly developing area. In that, resource allocation is an important enabling technology for cloud computing environments. The users will submit the service requests to clouds for computation. Along with the service requests user may give some constraints like deadline, budget, reliability, trust/security, etc. In this paper, we are considering two constraints deadline and budget. To improve the resource utilization and QoS, we are using the concept of RAINBOW service computing framework. We propose a cost and time optimization algorithm for allocating resources to service requests by considering multiple clouds, using the concept of RAINBOW framework in such a way that the user’s requirements are met with minimum cost. In cloud computing there is need for sharing resources like storage, processing time, memory, network bandwidth, etc. In this paper, we consider processing time as the main resource, which is to be allocated to competing clients.
A Forensic Accounting Examination of Financial Reporting Fraud at the Segment Level

The purpose of this study is to assess various financial reporting frauds that occurred at the segment-level. This study describes firm characteristics, the types of fraudulent activities, some of the financial effects, as well as the perpetrator of the fraud. Although one of the primary objectives of segment reporting is to increase the transparency of the firm, most of the emphasis in financial reporting is at the consolidated level. As the analysis here suggests, a more thorough examination of the segment level may uncover fraudulent transactions in a timelier manner. The data suggests that firms with significant bill and hold transactions may be more at risk for fraud at the segment level. We find that during the fraud period our sample firms appear to be performing better on average than comparable firms. This is not to say all above-average performing firms are committing fraud, but rather suggesting it could be one of many indicators that fraud may be occurring. These are possible fraud indicators that could be explored in future segment fraud research.
Accurate Transfer-Power Measurement for Wireless Charging of Electric Vehicles Under Misalignment

Transfer-power measurement (TPM) provides fair metering for wireless power transfer (WPT) in electric vehicles (EVs). TPM employs sense coils between the transmitter coils (Tx) and receiver coils (Rx) to estimate the transferred power from the magnetic field. Two sense coils are enough for power estimation when the transmitter and receiver positions are always fixed. However, misalignment of coils leads to errors which can be corrected by using more sense coils. In this paper, TPM under misalignment using multiple sense coils is introduced, which give implicit information about the misalignment. A quadratic approximation of coupling coefficients under misalignment is used to correct the errors. Numerical models from precise theory confirm the fidelity of the approximation and experimental results concur.
Stem cell models of human synapse development and degeneration

Many brain disorders exhibit altered synapse formation in development or synapse loss with age. To understand the complexities of human synapse development and degeneration, scientists now engineer neurons and brain organoids from human-induced pluripotent stem cells (hIPSC). These hIPSC-derived brain models develop both excitatory and inhibitory synapses and functional synaptic activity. In this review, we address the ability of hIPSC-derived brain models to recapitulate synapse development and insights gained into the molecular mechanisms underlying synaptic alterations in neuronal disorders. We also discuss the potential for more accurate human brain models to advance our understanding of synapse development, degeneration, and therapeutic responses.
Simulation optimization for Bayesian multi-arm multi-stage clinical trial with binary endpoints

Multi-arm multi-stage designs, in which multiple active treatments are compared to a control and accumulated information from interim data are used to add or remove arms from the trial, may reduce development costs and shorten the drug development timeline. As such, this adaptive update is a natural complement to Bayesian methodology in which the prior clinical belief is sequentially updated using the observed probability of success. Simulation is often required for planning clinical trials to accommodate the complexity of the design and to optimize key design characteristics. This paper addresses two key limiting factors in simulations, namely the computational burden and the time needed to obtain results. We first introduce a generic process for simulating Bayesian multi-arm multi-stage designs with binary endpoints. Then, to address the computational burden and time, we optimize the method for calculating the posterior probability and posterior predictive probability of success.
DC Kerr Effect and Limits for Silicon Photonic Modulators

We experimentally demonstrate the universal presence of the DC Kerr effect in silicon modulators and report performance trends and theoretical limits for DC Kerr effect optimization with implications for both digital and analog applications.
A Low-Cost, Point-of-Care Sickle Cell Anemia Screening Device for Use in Low and Middle-Income Countries

Sickle cell disease (SCD) is a common and life-threatening inherited blood disorder which can cause anemia, pain, organ damage, increased risk for infection, and reduced life expectancy. This disease is especially common in sub-Saharan Africa, where estimates suggest that the mortality rate among children is as high as 50–90% depending on the location. Despite this high mortality, universal screening and early intervention programs in high-income countries have proven to be effective at reducing the probability of death. The primary SCD diagnostic methods used in these areas, however, are expensive and resource-heavy. As a result, implementing SCD screening programs in sub-Saharan Africa has thus far been challenging, expensive, and limited only to small-scale programs. In order to address this need, this project is currently in the concept stage of designing a low-cost, easy-to-use, lateral flow sickle cell anemia diagnostic test to be used as a screening device in low and middle-income countries (LMICs). Efforts have so far focused on finding sensitive and specific capture and detection antibody pairs targeting normal hemoglobin A and sickle cell hemoglobin S. In addition, progress has been made in testing different lateral flow device configurations in order to establish a design which meets the economic, usability, and reliability demands of a sickle cell screening device for use in LMICs.
A Glucose Monitoring System With Remote Data Access

A cost-effective portable glucose monitoring system with remote data access based on a novel e-oscilloscope was developed using a glucose biofuel cell and a capacitor circuit interfaced to an ESP8266 microcontroller programmed to convert the charge/discharge rates of the capacitor functioning as a transducer. The capacitor charge/discharge rates were converted into glucose concentration readings that is monitored remotely. The glucose monitoring system comprise a glucose biofuel cell, a charge pump circuit, a capacitor and an ESP microcontroller. The anode was fabricated by modifying a gold microwire with nanoporous colloidal platinum (Au-co-Pt) and the cathode was constructed using a mesh dense network of multiwalled carbon nanotubes modified with bilirubin oxidase, respectively. The glucose monitoring system showed sensitivity of 1.18 Hz/mM $\cdot $ cm2 with a correlation coefficient of 0.9939 with increasing glucose concentration from 1 mM to 25 mM. In addition, the glucose monitoring system exhibited optimal operation at a pH of 7.4 and 37 °C, which is ideal for physiological glucose monitoring.
Quasi-elliptic dual-band bandpass filters based on series-cascaded multi-resonant cells

This paper reports on quasi-elliptic dual-band bandpass filters (BPFs) that were designed for the Filter Student Design Competition of the 2019 European Microwave Week. The proposed lumped-element (LE) BPF concept is based on two dual-band transversal cells and one multi-resonant cell that allow the realization of symmetric and asymmetric dual-band transfer functions shaped by six poles and five transmission zeros. A compact implementation scheme based on LE series resonators is proposed for size compactness and wide spurious free out-of-band response. For proof-of-concept demonstration purposes, a dual-band LE prototype with two passbands centered 1 and 1.5 GHz was designed, manufactured, and measured. It exhibited the following radio frequency measured performance characteristics. Passbands centered at 1.02 and 1.45 GHz, minimum insertion loss levels of 2.0 and 2.7 dB, and bandwidth of 146 and 105 MHz, respectively, for the first and the second passband, and out-of-band rejection >30 dB between 0 and 894 MHz, 1.17–1.34 GHz, and 1.72–6.9 GHz.
Denial-of-Service Vulnerability of Hash-based Transaction Sharding: Attacks and Countermeasures.

Since 2016, sharding has become an auspicious solution to tackle the scalability issue in legacy blockchain systems. Despite its potential to strongly boost the blockchain throughput, sharding comes with its own security issues. To ease the process of deciding which shard to place transactions, existing sharding protocols use a hash-based transaction sharding in which the hash value of a transaction determines its output shard. Unfortunately, we show that this mechanism opens up a loophole that could be exploited to conduct a single-shard flooding attack, a type of Denial-of-Service (DoS) attack, to overwhelm a single shard that ends up reducing the performance of the system as a whole. To counter the single-shard flooding attack, we propose a countermeasure that essentially eliminates the loophole by rejecting the use of hash-based transaction sharding. The countermeasure leverages the Trusted Execution Environment (TEE) to let blockchain's validators securely execute a transaction sharding algorithm with a negligible overhead. We provide a formal specification for the countermeasure and analyze its security properties in the Universal Composability (UC) framework. Finally, a proof-of-concept is developed to demonstrate the feasibility and practicality of our solution.
COVID-19 and the kidney

COVID-19 is primarily considered a respiratory illness, but the kidney may be one of the targets of SARS-CoV-2 infection, since the virus enters cells through the angiotensin-converting enzyme 2 receptor, which is found in abundance in the kidney. Information on kidney involvement in COVID-19 is limited but is evolving rapidly. This article discusses the pathogenesis of acute kidney injury (AKI) in COVID-19, its optimal management, and the impact of COVID-19 on patients with chronic kidney disease, patients with end-stage kidney disease on dialysis, and kidney transplant recipients.
Severity of Peri-ictal Respiratory Dysfunction With Epilepsy Duration and Patient Age at Epilepsy Onset

Respiratory dysfunction preceding death is fundamental in sudden unexpected death in epilepsy (SUDEP) pathophysiology. Hypoxia occurs with one-third of seizures. In temporal lobe epilepsy, there is volume loss in brainstem regions involved in autonomic control and increasing neuropathological changes with duration of epilepsy suggesting increasingly impaired regulation of ventilation. In animal models, recurrent hypoxic episodes induce long-term facilitation (LTF) of ventilatory function, however, LTF is less robust in older animals. LTF of ventilation may, to some degree, ameliorate the deleterious effects of progressive brainstem atrophy. We investigated the possibility that the duration of epilepsy, or age at epilepsy onset, may impact the severity of seizure-associated respiratory dysfunction. Patients with focal epilepsy undergoing video-EEG telemetry in the epilepsy monitoring unit (EMU) were studied. We found a significant relationship between age at epilepsy onset and duration of peri-ictal oxygen desaturation for focal seizures not progressing to bilateral tonic-clonic seizures, with longer duration of peri-ictal oxygen desaturation in patients with epilepsy onset at an older age but no significant relationships between duration of epilepsy or age at EMU admission and ventilatory dysfunction. Our findings suggest an intriguing possibility that LTF of ventilation may be protective when epilepsy starts at a younger age.
Do Innovations Really Pay Off? Total Stock Market Returns to Innovation

Critics often decry an earnings-focused short-term orientation of management that eschews spending on risky, long-term projects such as innovation to boost a firm's stock price. Such critics assume that stock markets react positively to announcements of immediate earnings but negatively to announcements of investments in innovation that have an uncertain long-term pay off. Contrary to this position, we argue that the market's true appreciation of innovation can be estimated by assessing the total market returns to the entire innovation project. We demonstrate this approach via the Fama-French 3-factor model (including Carhart's momentum factor) on 5,481 announcements from 69 firms in five markets and 19 technologies between 1977 and 2006. The total market returns to an innovation project are $643 million, more than 13 times the $49 million from an average innovation event. Returns to negative events are higher in absolute value than those to positive events. Returns to initiation occur 4.7 years ahead of launch. Returns to development activities are the highest and those to commercialization the lowest of all activities. Returns to new product launch are the lowest among all eight events tracked. Returns are higher for smaller firms than larger firms. Returns to the announcing firm are substantially greater than those to competitors across all stages. We discuss the implications of these results.
A Discussion of Artificial Intelligence Applications in SiC MOSFET Device Operation

Despite the several advantages, SiC MOSFETs suffer from issues such as low current carrying capacity, device degradation, etc. In this study, we explore the applications of Artificial Intelligence algorithms in optimizing the operation of SiC MOSFETs. We introduce the different notions of learning algorithms and provide a summary on their applications. In particular, we discuss earlier applications of AI algorithms in studying the properties of SiC MOSFETs, and highlight some challenges associated with parallel operation of SiC MOSFETs.
Forces that Shape the Cell

Systems biomechanics of the cell is a new area of study that focuses on system-level mechanical phenomena in the cell, notably involving interaction of the cell boundary with the cytoskeleton that it confines. Mechanical effects are reviewed that are associated with the conformations adopted by constrained microtubule fibers, including interphase asters of microtubules, mitotic cytoskeletons consisting of two coupled asters, and the cytoskeleton in interacting cells. Mechanical origin of stability and instability of symmetry, asymmetry, and structural multistability is highlighted. Dynamical effects of emergent irreversibility, hysteresis, and multiperiodic dissipative oscillations are also analyzed, leading to a discussion of the central place of systems biomechanics of the cell in the organization of living matter.
Catecholamine Receptors: Structure, Function, and Regulation

The various receptors for catecholamines, termed adrenergic receptors, represent excellent model systems for the study of receptor-mediated transmembrane signaling systems because of their ubiquity, coupling to well-defined effector mechanisms, and the clinical importance of drugs which interact with them. The β 1 and β 2-adrenergic receptors stimulate adenylyl cyclase via the guanine nucleotide regulatory protein Gs. The α 2-adrenergic receptors inhibit adenylyl cyclase via Gi. The α 1-adrenergic receptors stimulate hydrolysis of polyphosphoinositides by activating phospholipase C, thus generating inositol triphosphate and diacylglycerol. Each of these systems is in turn analogous to the retinal light transduction system which consists of the prototypic receptor rhodopsin, a G-protein transducin, and an effector enzyme, which is a cyclic GMP phosphodiesterase.
CHOOSING AN ADHESIVE FOR EXTERIOR WOODWORK THROUGH MECHANICAL TESTING

Through mechanical testing, an appropriate adhesive was found for reuniting the fragments of exterior wooden capitals. The adhesive needed to have superior weather resistance, flexibility, gap-filling capability, reversibility, longevity, and workability. From four different adhesive classes, a candidate adhesive was chosen for testing: Butvar B98 with granulated cork, ConServ Flexible Epoxy Patch 200, 3M Marine Adhesive Sealant 5200, DAP Dynaflex 230, and Dow Corning 738 Silicone Rubber with microballoons. The test program included cyclical tensile and compression tests, a uniaxial tensile test, and accelerated weathering. The Epoxy proved to be the most brittle, Butvar showed fatigue until failure, while 3M had excellent properties such as a low elastic modulus (high ductility), (visco)elastic behavior, and longevity. Both DAP and Dow Corning developed fissures in the paint prematurely and were eliminated from extensive cycling tests.
ON THE CONSERVATION OF TIBETAN THANG-KAS

A survey is given of problems encountered in the conservation of Tibetan painted banners. Deterioration of the binding medium can be treated with polyvinyl acetate solutions, but a thang-ka should not be glossy. Methods of reinforcing the fabric of the painting are described. Original borders should be saved and inscriptions on the back should be left exposed.
Compositional variations in the common pentanucleotide from transfer ribonucleic acids of Escherichia coli.

Abstract The common tetranucleotide T-Ψ-C-G was isolated from various Escherichia coli tRNA fractions and examined for the presence of uridine in the first (ribothymidine) or second (pseudouridine) positions. Approximately 13% uridine was found in the first position, and 30% uridine in the second position, of tetranucleotide from unfractionated tRNA, the aminoacylatable and nonaminoacylatable fractions, and from purified valine tRNA. Formylmethionine tRNA1, which possesses the sequence T-Ψ-C-A, was found to contain little if any uridine in these positions. E. coli was grown in the presence of 2-14C-uracil and 5-3H-uracil. Uridine was isolated from the ribothymidine and pseudouridine positions of the tetranucleotide, and the 3H:14C ratios compared with that of uridine from the bulk of the tRNA. No decrease in ratio was observed in either case, which indicates that modifications in the first and second positions are not reversible under our conditions of growth. We conclude that uridine is present in the first and second positions of T-Ψ-C-G because of incomplete modification at these sites. Tritium in the C-5 position of dihydrouridine and 4-thiouridine was also stable.
Early Education, Poverty, and Parental Circumstances among Hispanic Children: Pointing Toward Needed Public Policies

This article presents findings from two research projects concerning the educational achievement and well-being of Hispanic children. The first set of findings is from the first-ever study to calculate high school graduation rates for children with different levels of reading skill in third grade, by race-ethnicity and poverty experience. This research analyzes data from the 1979 National Longitudinal Survey of Youth (NLSY79) and is funded by the Annie E. Casey Foundation. The second set of findings draws on indicators from the Foundation for Child Development’s Child Well-Being Index (CWI), which is the nation’s most comprehensive measure of the overall well-being of children. Results for these indicators presented here measure poverty, median family income, Prekindergarten enrollment, and NAEP fourth-grade reading test scores (for data sources, see Hernandez & Napierala, 2012). Additional indicators measure parents’ educational attainments and fluency in speaking English. Finally, policy and program initiatives are recommended to improve the educational achievement and outcomes of Hispanic and other children, and to increase the economic security and well-being of their families.
The chvátal-gomory closure of an ellipsoid is a polyhedron

It is well-know that the Chvatal-Gomory (CG) closure of a rational polyhedron is a rational polyhedron. In this paper, we show that the CG closure of a bounded full-dimensional ellipsoid, described by rational data, is a rational polytope. To the best of our knowledge, this is the first extension of the polyhedrality of the CG closure to a non-polyhedral set. A key feature of the proof is to verify that all non-integral points on the boundary of ellipsoids can be separated by some CG cut. Given a point u on the boundary of an ellipsoid that cannot be trivially separated using the CG cut parallel to its supporting hyperplane, the proof constructs a sequence of CG cuts that eventually separates u. The polyhedrality of the CG closure is established using this separation result and a compactness argument. The proof also establishes some sufficient conditions for the polyhedrality result for general compact convex sets.
Experimental and theoretical investigations of a 17 GHz RF gun

Abstract We report on experimental and theoretical investigations of a 17 GHz RF photocathode electron gun. This is the first photocathode electron gun to operate at a frequency above 2.856 GHz. The 1.5 cell, π mode, copper cavity was tested with 50 ns pulses from a 17.150 GHz klystron amplifier built by Haimson Research Corp. A Bragg filter was used at the RF gun to reduce the reflection of parasitic modes back into the klystron. Coupling hole theory in conjunction with cold test measurements was used to determine the field profile in the RF gun. The particle in cell code MAGIC as well as coupled envelope equations were used to simulate the beam dynamics in the RF gun. With power levels of 4 MW, the on axis electric field at the cathode exceeds 300 MV/m, corresponding to an average accelerating gradient of 200 MV/m over the first half cell of the gun. Breakdown was observed at power levels above 5 MW. Electron bunches were produced by 20 μJ, 1 ps UV laser pulses impinging on the RF gun copper photocathode and were measured with a Faraday cup to have up to 0.1 nC of charge. This corresponds to a peak current of about 100 A, and a density at the cathode of 8.8 kA/cm2. Multiple output electron bunches were obtained for multiple laser pulses incident on the cathode. Phase scans of laser-induced electron emission reveal an overall phase stability of better than ±20°, corresponding to ±3 ps synchronization of the laser pulses to the phase of the microwave field. A Browne–Buechner magnetic spectrometer indicated that the RF gun generated 1 MeV electrons with a single shot rms energy spread of less than 2.5%, in good agreement with theoretical predictions.
Surface engineering superparamagnetic nanoparticles for aqueous applications: design and characterization of tailored organic bilayers

Engineered superparamagnetic nanoparticles (NPs) have broad potential in biotechnologies, high contrast magnetic resonance imaging, and advanced environmental sensing and remediation technologies, among others. For successful environmental, aqueous-based applications, particle stability (as highly monodisperse and single domain nanocrystals) and specific surface functionality are critical to control. In this report, aqueous stabilization of 8 nm superparamagnetic iron oxide NPs is described and optimized using a series of surface engineered bilayers, exploring 13 ionic surfactants, which are systematically varied with regard to hydrophobic tail (size and properties) and polar head groups. As monodispersed aqueous suspensions, material libraries were evaluated through particle–particle aggregation kinetics (with varied ionic types and strengths) and long-term aqueous stabilities (up to one year). Optimal phase transfer approaches are presented, along with corresponding particle stability characterization data sets for each of the 13 ligands studied, which, when taken together, allow for flexible surface design strategies for a variety of superparamagnetic particle-based aqueous applications.
From cultural diversity to group creativity: using language-retrieved pictures to support computer-mediated intercultural brainstorming

International and intercultural groups increasingly perform various kinds of knowledge work that require groups to brainstorm or generate new ideas, such as problem solving, intelligence analysis and design. One observation based on the understanding of cultural differences and group idea generation suggests that cultures, or socially shared systems of concepts and practices among communities of people, introduce both benefits and obstacles to intercultural brainstorming. Cultural diversity in concepts and ways of thinking is in general beneficial, while cultural discrepancy in social norms, communication styles and language can be detrimental to idea sharing and brainstorming outcomes. The major goal of this dissertation is to reconcile the tension between the benefits and obstacles of intercultural collaboration. In this dissertation, I investigate how people with different cultural backgrounds communicate to perform brainstorming. I further propose brainstorming support tools accordingly, and evaluate the designs in the contexts of cross-cultural and cross-lingual brainstorming. The dissertation considers that using computers to retrieve and display language-retrieved pictures, which are pictures relevant to the ongoing conversation, can effectively support intercultural brainstorming. As individuals from different cultures vary in terms of how they perceive and interpret image content, the design attempts to present pictures to elicit diverse thoughts from members of intercultural groups. A study confirms the usefulness of this design for American-Chinese intercultural groups. The dissertation further considers to bridge cultures at the language level, using machine translation (MT) to allow group members to produce and read ideas in their native languages. Another study shows that MT supports the production of ideas but not the comprehension of ideas. The results point to the need to further investigate the detailed processes for producing and comprehending ideas in intercultural groups to inform future designs. The dissertation contributes to the understanding of computer-mediated intercultural brainstorming with behavioral studies and design work, and shows the need for technical designs to take understanding of various aspects of culture, such as social and communicative norms, cognition and languages spoken, into consideration.
Modeling and simulation of morphogenesis by cell rearrangement

A mechanical model for studying tissue morphogenesis by directed cell neighbor change is proposed. The model describes cell rearrangements by accounting for the balance of forces between neighboring cells that are functionally coupled. It allows for the testing of assumptions and theories in a precise and rigorous manner incorporating known biological and physical principles. The model is applied to two embryological processes: epiboly in the killyfish Fundulus and notochord extension in the frog Xenopus. It is noted that changing model parameters, such as the boundary conditions of the mechanical properties of a motile or adhesive cell subpopulation, allows the model to be applied in a wide range of settings in developmental and cell biology. It can be used as a testbed for investigating the mechanical conditions underlying normal embryonic development and for investigating the cellular mechanical properties responsible for developmental abnormalities. >
An Examination of Student Engagement, Knowledge Creation and Expansive Learning in a Virtual World

This chapter examines engagement, creation of knowledge, and expansive learning of undergraduate students using a virtual world. After creating a 3D, didactic, constructivist virtual world, researchers recorded and analysed student conversations within the environment. Using Hara et al. (Instr Sci, 28:115–152, 2000) framework for student engagement and Nonaka and Takeuchi (The knowledge-creating company: how Japanese companies create the dynamics of innovation, The Oxford University Press, New York, 1995) knowledge creation theory the data were analysed. The theory of expansive learning served as a framework for exploring transformations in the environment (Engestrom, Sannino, Educ Res Rev, 5(1):1–24, 2010). Findings revealed that five forms of student engagement amplified the learning process and that a complete knowledge spiral occurred emphasising the four modes of knowledge conversion and hinting at elements of expansive learning (Engestrom, Sannino, Educ Res Rev, 5(1):1–24, 2010) occurring. Though limited in time and scope, results further suggest that a highly engaged community of learners with the ability to solve problems critically was created within the 3D virtual world.
Assessing wind wave spectrum representations in a shallow lake

Abstract This paper presents an objective assessment of three published wave spectrum formulas for the shallow sea. It compares wave spectra estimated by these formulas with those calculated from actual field measurements made in Lake Erie during 1981 in depths ranging from 1.4 to 14.0 m. The results show that the models each have various degrees of effectiveness and applicability. The choice of which model to use may depend upon the availability of input parameters, and is still basically subjective. The models specifically developed for the shallow depth are found to be less effective. The form of spectral representation may remain similar at all depths, with depth affecting only the wave parameters that characterize the spectrum form.
NOVEL PLANT SECONDARY METABOLITES IMPACT DIETARY SPECIALISTS MORE THAN GENERALISTS (NEOTOMA SPP)

Theory predicts that dietary specialization is limited in part because of phys- iological trade-offs associated with specialization. Specifically, dietary specialists are pre- dicted to evolve mechanisms that reduce costs and enhance excretion of plant secondary metabolites (PSMs) that they frequently consume, but are less energetically and/or mech- anistically efficient at eliminating novel PSMs. Although examples of trade-offs associated with dietary specialization have been documented among insects, trade-offs have not been investigated in mammalian herbivores. To initially investigate the physiological trade-offs associated with specialization in mammalian herbivores, we determined the impact of in- gesting novel PSMs on the energy budgets of a juniper specialist (Neotoma stephensi) and generalist (N. albigula) woodrat. These results were then compared to the impact of juniper intake, the plant species preferred by the specialist, on energy budgets in these same species. Energy budgets were evaluated by measuring apparent metabolizable energy intake (AMEI, energy consumed 2 energy excreted) and energy expended on basal metabolic rate (BMR) and voluntary wheel running in specialist and generalist woodrats fed a formulated diet with and without PSMs from the novel plant creosote (Larrea tridentata). Both specialists and generalists were energetically impacted by the intake of a diet containing novel PSMs, primarily through decreased intake of creosote diet and increased excretion of energy in the urine. However, specialists were impacted to a greater extent than generalists. Specialists decreased body mass, whereas generalists maintained body mass. Specialists also reduced intake and AMEI when consuming creosote diet compared to control to a greater extent than generalists. In turn, specialists had one-sixth the energy available for energy dependent activities than generalists on a diet containing novel PSMs. These results are in stark contrast to the comparisons between specialists and generalists consuming PSMs from their natural diet. Specialists consumed more juniper, had higher AMEI and available energy than gen- eralists when fed diets containing juniper foliage. These data provide the first support that physiological trade-offs associated with dietary specialization may exist in mammalian
Basin-scale relations via conditioning

A rainfall-runoff model is used in conjunction with a probabilistic description of the input to this model to obtain simple regression-like relations for basin runoff in terms of basin and storm characteristics. These relations, similar to those sought in regionalization studies, are computed by evaluating the conditional distribution of model output given basin and storm characteristics. This method of conditioning provides a general way of examining model sensitivity to various components of model input. The resulting relations may be expected to resemble corresponding relations obtained by regionalization using actual runoff to the extent that the rainfall-runoff model and the model input specification are physically realistic. The probabilistic description of model input is an extension of so-called “random-model” of channel networks and involves postulating an ensemble of basins and associated probability distributions that mimic the variability of basin characteristics seen in nature. Application is made to small basins in the State of Wyoming. Parameters of the input variable distribution are estimated using data from Wyoming, and basin-scale relations are estimated both, parametrically and nonparametrically using model-generated runoff from simulated basins. Resulting basin-scale relations involving annual flood quantiles are in reasonable agreement with those presented in a previous regionalization study, but error estimates are smaller than those in the previous study, an artifact of the simplicity of the rainfall-runoff model used in this paper. We also obtain relations for peak of the instantaneous unit hydrograph which agree fairly well with theoretical relations given in the literature. Finally, we explore the issues of sensitivity of basin-scale, relations and error estimates to parameterization of the model input probability distribution and of how this sensitivity is related to making inferences about a particular ungaged basin.
The structure of synaptosomal plasma membrane

Synaptosomal plasma membrane (SPM), like other plasma membranes, is composed of lipids and proteins and appears to conform to the "fluid mosaic" model proposed by Singer and Nicolson. SPM components show a marked asymmetry with respect to their inside-outside distribution, with the majority of proteins being external. The lateral distribution of proteins is also somewhat asymmetric; this asymmetry is maintained by the immobilization of species at the junction.
Corrosion behaviour of a steel surface laser alloyed with chromium borides

The corrosion behaviour of a carbon steel surface laser alloyed with chromium borides was investigated using electrochemical and surface analytical methods. Chromium and boron were unevenly distributed in the laser-alloyed layer. The distribution of chromium controlled the anodic dissolution of the alloy. Iron was dissolved preferentially from the surface and a loose corrosion product layer enriched in chromium was formed during active dissolution in 0.1m H2SO4. The chromium boride inclusions on the surface promoted hydrogen evolution and controlled cathodic behaviour. In neutral and basic solutions, the corrosion behaviour of the laser-alloyed surface was very close to that of the matrix steel. The effects of the alloying elements on corrosion behaviour are discussed.