cssi/SciSciGPT-SciSciNet huggingface dataset:
Bulk Mechanical Properties Testing of Metallic Marginal Glass Formers

We developed a unique three-point bend testing apparatus to measure bulk mechanical properties of a model metallic glass alloy (SAM2X5 with nominal composition Fe49.7Cr17.1Mn1.9Mo7.4W1.6B15.2C3.8Si2.4) prepared by spark plasma sintering. The relatively large sample sizes in the present work allowed for the preparation of test specimens with a macroscale cross section (in the millimeter range) with well-controlled sample dimensions closer to standardized tests. Wire saw cutting allowed for a relatively sharp notch radius (3x smaller than previous studies) and minimal sample damage. We determined that Young’s modulus and notch fracture toughness measured by our three-point bending apparatus are 230 GPa and 4.9 MPam1/2. Also, Vickers indentation and flexure testing provided consistent results for Young’s modulus. Indentation fracture toughness measured by Vickers indentation produced values at least 50% lower than by flexure. The microscale mechanical properties testing technique presented in this work and subsequent analyses are applicable to specimens of other compositions or ones prepared by other methods.
VCSELs for 10 GB/s optical interconnects

This paper explores the use of vertical cavity surface emitting lasers (VCSEL) for optical interconnects operating at speeds of 10 GB/s and beyond. The application of 10 GB/s optical interconnects is being driven by both the data communications and the telecommunications industry, and the lines of demarcation in application are beginning to blur.
Characterization of ankle function during stair ambulation

The aim of this study was to examine the ankle joint during level walking, stair ascent, and stair descent to determine models for use in the design of prosthetic and orthotic systems. Ten healthy subjects were asked to walk (1) across a level walkway, (2) up, and (3) down an instrumented stairway. Sagittal plane kinematic and kinetic data were analyzed to obtain ankle biomechanics during the stance phase of each task. Each stance phase was broken down into sub-phases based on the power trajectory. The ideal model was taken to be the simplest combination of mechanical elements (springs, dampers, and torque actuators) that could reproduce the patterns observed in ankle biomechanics. Besides, we studied the transitions from level walking to stair ascent and from stair descent to level walking and showed that mechanical elements can be used to model these transitions as well. These results are promising to the design of next generation ankle orthotic and prosthetic systems because they show that relatively simple mechanical elements can be utilized to mimic ankle biomechanics.
Behavioral response of brook trout and brown trout to acidification and species interactions

Many factors have been associated with the decline of brook trout (Salvelinus fontinalis) throughout their native range including acidification and competition with brown trout (Salmo trutta), an introduced species. We observed the behavior of wild, adult brook trout and brown trout (alone and in combination) within study reaches that were manipulated to vary the level of acidity and CO2. The aims of the study were to address 1) if acidification affects the segregation patterns of wild, adult brook trout and brown trout and 2) whether interactions among brook trout and brown trout influence the distribution of brook trout in acidified waters. After manipulating acidity levels, the majority of indwelling fish responded to acidification by moving to more neutral conditions (62 % of brook trout and 68 % of brown trout). Indwelling brook trout spent less time in acidic conditions during the acid treatment (41 ± 5 %) than during the control period (94 ± 2 %). Indwelling brown trout spent less time in the acid conditions during the acid treatment (44 ± 4 %) than during a control period (98 ± 1 %). The proportion of time spent in the acid water by indwelling trout decreased as negative interactions with other fish (such as chasing) increased. Presence of the opposite species did not influence the proportion of time spent in the acidic conditions. The results of this study do not support the hypothesis that acidification mediates the segregation of brook trout and brown trout in streams.
An Interpretive Framework for Narrower Immunity Under Section 230 of the Communications Decency Act

Almost all courts to interpret Section 230 of the Communications Decency Act have construed its ambiguously worded immunity provision broadly, shielding Internet intermediaries from tort liability so long as they are not the literal authors of offensive content. Although this broad interpretation effects the basic goals of the statute, it ignores several serious textual difficulties and mistakenly extends protection too far by immunizing even direct participants in tortuous conduct.This analysis, which examines the text and history of Section 230 in light of two strains of pre-Internet vicarious liability defamation doctrine, concludes that the immunity provision of Section 230, though broad, was not intended to abrogate entirely traditional common law notions of vicarious liability. Some bases of vicarious liability remain, and their continuing validity both explains the textual puzzles courts have faced in applying Section 230 and undergirds the push by a small minority of courts to narrow the section's immunity provision.
Assessing dissolved carbon transport and transformation along an estuarine river with stable isotope analyses

Abstract Estuaries play an important role in the dynamics of dissolved carbon from rivers to coastal oceans. However, our knowledge of dissolved carbon transport and transformation in mixing zones of the world's coastal rivers is still limited. This study aims to determine how dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) concentrations and stable isotopes (δ13CDIC and δ13CDOC) change along an 88-km long estuarine river, the Calcasieu River in Louisiana, southern USA, with salinity ranging from 0.02 to 21.92. The study is expected to elucidate which processes most likely control carbon dynamics in a freshwater-saltwater mixing system, and to evaluate the net metabolism of this estuary. Between May 2015 and February 2016, water samples were collected and in-situ measurements on ambient water conditions were performed during five field trips at six sites from upstream to downstream of the Calcasieu River, which enters the Northern Gulf of Mexico (NGOM). The DIC concentration and δ13CDIC increased rapidly with increasing salinity in the mixing zone. The average DIC concentration and δ13CDIC at the site closest to the NGOM (site 6) were 1.31 mM and −6.34‰, respectively, much higher than those at the site furthest upstream (site 1, 0.42 mM and −20.83‰). The DIC concentrations appeared to be largely influenced by conservative mixing, while high water temperature may have played a role in deviating DIC concentration from the conservative line due likely to increased respiration and decomposition. The δ13CDIC values were close to those suggested by the conservative mixing model for May, June and November, but lower than those for July and February, suggesting that an estuarine river can fluctuate from a balanced to a heterotrophic system (i.e., production/respiration (P/R)
Blending Measures of Programming and Social Behavior into Predictive Models of Student Achievement in Early Computing Courses

Analyzing the process data of students as they complete programming assignments has the potential to provide computing educators with insights into both their students and the processes by which they learn to program. In prior research, we explored the relationship between (a) students’ programming behaviors and course outcomes, and (b) students’ participation within an online social learning environment and course outcomes. In both studies, we developed statistical measures derived from our data that significantly correlate with students’ course grades. Encouraged both by social theories of learning and a desire to improve the accuracy of our statistical models, we explore here the impact of incorporating our predictive measure derived from social behavior into three separate predictive measures derived from programming behaviors. We find that, in combining the measures, we are able to improve the overall predictive power of each measure. This finding affirms the importance of social interaction in the learning process, and provides evidence that predictive models derived from multiple sources of learning process data can provide significantly better predictive power by accounting for multiple factors responsible for student success.
Multiple-channel ultra-violet absorbance detector for two-dimensional chromatographic separations.

Abstract In recent years, much research has gone into developing online comprehensive two-dimensional liquid chromatographic systems allowing for high peak capacities in comparable separation times to that of one-dimensional liquid chromatographic systems. However, the speed requirements in the second dimension (2nd-D) still remain one challenge for complex biological samples due to the current configuration of two column/two detector systems. Utilization of multiple 2nd-D columns can mitigate this challenge. To adapt this approach, we need a multiple channel detector. Here we develop a versatile multichannel ultraviolet (UV) light absorbance detector that is capable of simultaneously monitoring separations in 12 columns. The detector consists of a deuterium lighthouse, a flow cell assembly (a 13-channel flow cell fitted with a 13-photodiode-detection system), and a data acquisition and monitoring terminal. Through the use of a custom high optical quality furcated fiber to improve light transmission, precise machining of a flow cell to reduce background stray light through precision alignment, and sensitive electronic circuitry to reduce electronic noise through an active low pass filter, the background noise level is measured in the tens of µAU. We obtain a linear dynamic range of close to three orders of magnitude. Compared to a commercialized multichannel UV light absorbance detector like the Waters 2488 UV/Vis, our device provides an increase in channel detection while residing within the same noise region and linear range.
Contemporary Surgical Trends in the Management of Symptomatic Meniscal Tears among United States Military Servicemembers from 2010 to 2015.

The purpose of this investigation is to report on trends over time in the treatment of meniscal pathology among military orthopaedic surgeons, as well as to evaluate the impact of patient demographics and concomitant procedure on the type of meniscal procedure performed. We performed a retrospective analysis of all active-duty United States military servicemembers who underwent a meniscal procedure from 2010 to 2015 within the Military Health System. Patient demographics and surgical variables were extracted from the electronic medical record. Treatments were categorized by location and by type of intervention (i.e., repair or debridement). Chi-square and linear regression analyses were performed to identify temporal trends in meniscal procedures and factors that were correlated with the type of meniscal procedure performed. Out of 29,571 meniscal procedures analyzed, partial meniscectomy was performed in 81.3% (n = 24,343) of cases, meniscal repair in 20.3% (n = 6,073), and meniscus allograft transplantation (MAT) in 0.7% (n = 206). The rates of debridement, repair, and concomitant surgeries did not demonstrate any significant temporal trends, whereas MAT demonstrated a significant decrease in overall utilization. Nearly two-thirds of all meniscal procedures were performed in the medial compartment. MAT occurred equally between the medial and lateral compartments. Lateral meniscal lesions demonstrated significantly higher rates of debridement. With each year of advancing age, there was a 3.7% increasing likelihood of meniscectomy and 6.5% decreasing likelihood of repair. Females were more likely to undergo meniscal repair than males. Patients in the military population were more likely to undergo meniscal repair compared with previously reported rates in the civilian population. In this physically active cohort of nearly 30,000 military patients, 1 in 5 meniscal tears were treated with meniscal repair. Meniscal repairs were performed at a higher rate for all age groups compared with previously reported rates in the civilian population. Further research is required to elucidate the causative factors behind these differences and the effect on postoperative outcomes. Level of Evidence: IV, cross-sectional study.
Genome Sequence of JangDynasty, a Newly Isolated Mycobacteriophage.

ABSTRACT JangDynasty is a bacteriophage that infects Mycobacterium smegmatis mc2155. It has a genome length of 70,883 bp, with 124 predicted open reading frames (ORFs), 42 of which have known functions. JangDynasty belongs to cluster O, and like other cluster O phages, it is a siphovirus with a prolate capsid.
Tracheoesophageal Prosthesis Use Is Associated With Improved Overall Quality of Life in Veterans With Laryngeal Cancer.

Objectives:Veterans have an increased risk of laryngeal cancer, yet their oncologic and functional outcomes remain understudied. We sought to determine the longitudinal impact of tracheoesophageal ...
Experimental Study on Deployment of Mobile Edge Computing to Improve Wireless Video Streaming Quality

Due to the rapid increase in wireless network traffic, especially video traffic, innovative network architectures and algorithms need be developed to reduce congestion and improve the quality of service (QoS). Multi-access edge computing or mobile edge computing (MEC) is a new paradigm that integrates computing and storage capabilities at the edge of the wireless network. In this paper, we design and implement a wireless access network-aware video streaming system based on the MEC concept, called Edge-Controlled Adaptive Streaming (ECAS). ECAS employs in-network video bitrate adaptation to improve data delivery efficiency. In our design, a MEC function intercepts HTTP requests from the client, and a rate adaptation mechanism is employed to decide the best video representation for the client. Updated HTTP requests, with modified video rates based on the adaptation decision, are forwarded to the video server. We also design a resource allocation and streaming bitrate adaptation algorithm to achieve the overall optimization of multiple video streams, with fairness, subject to wireless transmission capacity constraint. This network-assisted adaptive streaming approach allows more accurate estimation of wireless network states and can enhance the QoS of multiple video streams. A prototype is implemented to prove the concept, and the experimental results demonstrate that the proposed scheme significantly improves video streaming performance compared to the de facto standard video streaming technique, Dynamic Adaptive Streaming over HTTP (DASH).
Discovering Structure in a Corpus of Schemas.

This paper describes a research program that exploits a large corpus of database schemas, possibly with associated data and meta-data, to build tools that facilitate the creation, querying and sharing of structured data. The key insight is that given a large corpus, we can discover patterns concerning how designers create structures for representing domains. Given these patterns, we can more easily map between disparate structures or propose structures that are appropriate for a given domain. We describe the first application of our approach to the problem of semi-automatic schema matching.
Role of variation in the serotonin transporter protein gene (SLC6A4) in trait disturbances in the ventral anterior cingulate in bipolar disorder.

Bipolar disorder (BD) is associated with abnormalities of the ventral anterior cingulate cortex (vACC) and its connection sites, including the amygdala, which are key components of a corticolimbic neural system that subserves emotional regulation. Decreased functional connectivity from the vACC to the amygdala in healthy individuals is associated with the short “s” allele—as opposed to the long “l” allele—of a well-known serotonin transporter promoter polymorphism (5-HTTLPR, locus SLC6A4), as are features of BD. This study tests the hypothesis that the s allele influences dysfunction in the vACC-amygdala neural system in BD. Thirty euthymic individuals with BD (20 s carriers, 10 ll) and 48 healthy comparison (HC) participants (34 s, 14 ll) participated in an event-related functional magnetic resonance imaging scan while processing fearful, happy, or neutral faces. During fear and happy face processing, vACC activation was significantly lower in the BD compared to the HC group, and in s carriers compared to ll individuals within both the HC and BD groups, such that BD s carriers exhibited the greatest magnitude of vACC dysfunction. No significant differences were detected in amygdala activation. The findings suggest that the 5-HTTLPR s allele may contribute to a trait-related, genetically-derived, neurobiological subgroup within BD characterized by prominent vACC dysfunction. Future treatment may be optimized for this BD subgroup by targeting the serotonergic system and the vACC.
Population assessment of head and neck cancer outcomes by race and HPV status in chance.

6045Background: Growing literature suggests that racial disparities exist in patients with head and neck squamous cell carcinoma (HNSCC). Currently, there are many hospital-based cohorts assessing ...
City with a billion dollar view

The growth and intensification of many urban areas has meant city governments increasingly face pressure to limit development to preserve iconic city views. This is frequently achieved through ‘vie...
Stakeholder Perspectives on the Use of Community Health Workers To Improve Palliative Care Use by African Americans with Cancer.

Abstract Background: African Americans in the United States have worse end-of-life care and cancer outcomes than whites. Palliative care may improve this disparity. Community Health Workers may pro...
Sulfur isotope analysis of microcrystalline iron sulfides using secondary ion mass spectrometry imaging: Extracting local paleo-environmental information from modern and ancient sediments.

Author(s): Bryant, Roger N; Jones, Clive; Raven, Morgan R; Gomes, Maya L; Berelson, William M; Bradley, Alexander S; Fike, David A | Abstract: RATIONALE:Sulfur isotope ratio measurements of bulk sulfide from marine sediments have often been used to reconstruct environmental conditions associated with their formation. In situ microscale spot analyses by secondary ion mass spectrometry (SIMS) and laser ablation multiple-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) have been utilized for the same purpose. However, these techniques are often not suitable for studying small (≤10 μm) grains or for detecting intra-grain variability. METHODS:Here, we present a method for the physical extraction (using lithium polytungstate heavy liquid) and subsequent sulfur isotope analysis (using SIMS; CAMECA IMS 7f-GEO) of microcrystalline iron sulfides. SIMS sulfur isotope ratio measurements were made via Cs+ bombardment of raster squares with sides of 20-130 μm, using an electron multiplier (EM) detector to collect counts of 32 S- and 34 S- for each pixel (128 × 128 pixel grids) for between 20 and 960 cycles. RESULTS:The extraction procedure did not discernibly alter pyrite grain-size distributions. The apparent inter-grain variability in 34 S/32 S in 1-4 μm-sized pyrite and marcasite fragments from isotopically homogeneous hydrothermal crystals was ~ ±2‰ (1σ), comparable with the standard error of the mean for individual measurements (≤ ±2‰, 1σ). In contrast, grain-specific 34 S/32 S ratios in modern and ancient sedimentary pyrites and marcasites can have inter- and intra-grain variability g60‰. The distributions of intra-sample isotopic variability are consistent with bulk 34 S/32 S values. CONCLUSIONS:SIMS analyses of isolated iron sulfide grains yielded distributions that are isotopically representative of bulk 34 S/32 S values. Populations of iron sulfide grains from sedimentary samples record the evolution of the S-isotopic composition of pore water sulfide in their S-isotopic compositions. These data allow past local environmental conditions to be inferred.
Simultaneous multi-wavelength laser spot detection and beam wander measurement using novel polymer imaging system

Comparison of optical propagation properties in different wavelength regimes are difficult to measure, especially in continuous varying environment. Detector and measurement equipment are typically optimized for specific spectral band and utilize matching amplifiers with have different response and process time making it hard or impossible to match time sensitive data. In this paper we propose the use of a wavelength conversion imaging system which has a broad spectral response and large detector size for synchronous multi-wavelength measurement. We showcase the strength of this approach in comparing the effect of turbulence media on a 1.55 μm and a 4 μm lasers at ambient (20 °C), 45 °C and 75 °C air temperature. Recording the movement and size of the lasers spot and comparing it frame to frame allows for extraction of the effect of turbulence on the individual lasers. Furthermore using cross correlation technique the conditions under which a good comparison can be identified. The result shows peak at 0s time shift for 45 °C and 75 °C which confirms the correlated measurement while the beam wander shows no correlation for ambient temperature as it is random.
Prior Experience and the Emergence of Hierarchy in Young Firms

A chief role of firms is to coordinate fragmented information to achieve superior performance. Yet firms differ widely in their abilities to do so. We examine how founding team conditions influence...
Instability in a coiled-coil signaling helix is conserved for signal transduction in soluble guanylyl cyclase

How nitric oxide (NO) activates its primary receptor, α1/β1 soluble guanylyl cyclase (sGC or GC-1), remains unknown. Likewise, how stimulatory compounds enhance sGC activity is poorly understood, hampering development of new treatments for cardiovascular disease. NO binding to ferrous heme near the N-terminus in sGC activates cyclase activity near the C-terminus, yielding cGMP production and physiological response. CO binding can also stimulate sGC, but only weakly in the absence of stimulatory small-molecule compounds, which together lead to full activation. How ligand binding enhances catalysis, however, has yet to be discovered. Here, using a truncated version of sGC from Manduca sexta, we demonstrate that the central coiled-coil domain, the most highly conserved region of the ~150,000 Da protein, not only provides stability to the heterodimer but is also conformationally active in signal transduction. Sequence conservation in the coiled coil includes the expected heptad-repeating pattern for coiled-coil motifs, but also invariant positions that disfavor coiled-coil stability. Full-length coiled coil dampens CO affinity for heme, while shortening of the coiled coil leads to enhanced CO binding. Introducing double mutation αE447L/βE377L, predicted to replace two destabilizing glutamates with leucines, lowers CO binding affinity while increasing overall protein stability. Likewise, introduction of a disulfide bond into the coiled coil results in reduced CO affinity. Taken together, we demonstrate that the heme domain is greatly influenced by coiled-coil conformation, suggesting communication between heme and catalytic domains is through the coiled coil. Highly conserved structural imperfections in the coiled coil provide needed flexibility for signal transduction.
Addressing the carbon footprint, healthfulness, and costs of self-selected diets in the USA: a population-based cross-sectional study.

Summary Background The role of diet in health is well established and, in the past decade, more attention has been given to the role of food choices in the environment. The agricultural sector produces about a quarter of the world's greenhouse gas emissions (GHGE), and meat production, especially beef, is an important contributor to global GHGE. Our study aimed to address a fundamental gap in the diet-climate literature: identifying consumers who are receptive to making dietary changes, and the effect of their potential changes on GHGE, diet healthfulness, and diet costs. Methods Dietary data on US individuals from a nationally representative survey were linked to food-related GHGE. We identified individuals receptive to changing their diets (potential changers) as those who reported trying US dietary guidance and were likely to agree that humans contribute to climate change. We assessed GHGE, diet healthfulness measured by the Healthy Eating Index (HEI), and diet costs before and after hypothetical changes replacing either beef or meats with poultry or plant-protein foods. Findings Our sample comprised 7188 individuals, of whom 16% were potential changers. These were disproportionately women, highly educated, or had higher income compared with individuals deemed not likely to change. Replacing 100% of beef intake in potential changers with poultry reduced mean dietary GHGE by 1·38 kg CO2-equivalents per person per day (95% CI 1·19–1·58), a 35·7% decrease. This replacement also increased mean HEI by 1·7% and reduced mean diet costs by 1·7%. We observed the largest changes when replacing all beef, pork, or poultry intake with plant-protein foods (GHGE decreased by 49·6%, mean HEI increased by 8·7%, and dietary costs decreased by 10·5%). Hypothetical replacements in the potential changers alone resulted in whole population reductions in 1-day dietary GHGE of 1·2% to 6·7%, equivalent to 22–126 million fewer passenger vehicle km. Interpretation Individual-level diet studies that include a variation in response by consumers can improve our understanding of the effects of climate policies such as those that include sustainability information in national dietary guidance. In our study, we found that changes by a small percentage of motivated individuals can modestly reduce the national dietary GHGE. Moreover, these substitutions can modestly improve diet healthfulness and reduce diet costs for individuals who make these changes. Funding Wellcome Trust.
Treating multiple sclerosis and neuromyelitis optica spectrum disorder during the COVID-19 pandemic.

The emergence of novel coronavirus 2019 (COVID-19)1 and the subsequent pandemic present a unique challenge to neurologists managing patients with multiple sclerosis (MS) and related neuroinflammatory disorders, such as neuromyelitis spectrum disorder (NMOSD).
Direct 3D bioprinting of cardiac micro-tissues mimicking native myocardium.

Abstract The heart possesses a complex three-dimensional (3D) laminar myofiber organization; however, because engineering physiologically relevant 3D tissues remains a technical challenge, the effects of cardiomyocyte alignment on excitation-contraction coupling, shortening and force development have not been systematically studied. Cellular shape and orientations in 3D can be controlled by engineering scaffold microstructures and encapsulating cells near these geometric cues. Here, we show that a novel method of cell encapsulation in 3D methacrylated gelatin (GelMA) scaffolds patterned via Microscale Continuous Optical Printing (μCOP) can rapidly micropattern neonatal mouse ventricular cardiomyocytes (NMVCMs) in photocrosslinkable hydrogels. Encapsulated cardiomyocytes preferentially align with the engineered microarchitecture and can display morphology and myofibril alignment phenotypic of myocardium in vivo. Utilizing the μCOP system, an asymmetric, multi-material, cantilever-based scaffold was directly printed, so that the force produced by the microtissue was transmitted onto a single deformable pillar. Aligned 3D encapsulated NMVCM scaffolds produced nearly 2 times the force compared to aligned 2D seeded samples. To further highlight the flexibility of μCOP, NMVCMs were encapsulated in several patterns to compare the effects of varying degrees of alignment on tissue displacement and synchronicity. Well aligned myofiber cultured patterns generated 4–10 times the contractile force of less anisotropically patterned constructs. Finally, normalized fluo-4 fluorescence of NMVCM-encapsulated structures showed characteristic calcium transient waveforms that increased in magnitude and rate of decline during treatment with 100 nM isoproterenol. This novel instrumented 3D cardiac microtissue serves as a physiologically relevant in vitro model system with great potential for use in cardiac disease modeling and drug screening.
Zonal-Based Emission Source Term Model for Predicting Particulate Emission Factors in Wildfire Simulations

A physics/chemistry-based numerical model for predicting the emission of fine particles from wildfires is proposed. This model implements the fundamental mechanisms of soot formation in a combustion environment: soot nucleation, surface growth, agglomeration, oxidation, and particle fragmentation. These mechanisms occur on a scale too fine for the discretization of most wildfire models, which need to simulate landscape-scale dynamics. As a result this model implements a zonal approach, where the computed soot particle distribution is partitioned into process zones within a single resolved grid cell. These process zones include: an inception zone (for nucleation), a heating zone (for coagulation, surface growth, and fragmentation), a reaction zone (for oxidation), and a quenched zone (for atmospheric processes). Governing mechanisms are applied to the appropriate zones to predict total particle growth and emission. The proposed model is implemented into HIGRAD/FIRETEC, a physics-based wildfire simulation code which couples interactions between fire, fuels, atmosphere, and topography on a landscape scale. Fire simulations among grasslands and conifer forests are performed and compared against experimental data for emission factors.
Extended Mittag-Leffler function, series and its sum

This paper introduces first order extended Mittag-Leffler function by using generalized polynomial factorials. By applying generalized l–difference operator, we obtain a formula for the series having extended Mittag-Leffler functions which has several applications in fractional calculus. Suitable examples and numerical verification by MATLAB are inserted to validate our findings.
Development of a World Class Silicon Carbide Substrate Manufacturing Capability

Silicon carbide (SiC) semiconductor substrates provide the foundation for revolutionary improvements in the cost, size, weight and performance of a broad range of military and commercial radio frequency (RF) and power switching devices. Due to the lack of a viable, native gallium nitride (GaN) substrate, semi-insulating (SI) SiC substrates are the substrate of choice for high power AlGaN/GaN High Electron Mobility Transistors (HEMTs) due to their near lattice-match to GaN, superior thermal conductivity and commercial availability. GaN has emerged as the technology of choice for RF power because of its superior output power capability compared to other semiconductors. Similarly, semi-conducting (N+) SiC substrates are required for fabrication of high voltage Schottky Diodes and Metal Oxide Semiconductor Field Effect Transistor (MOSFET) power switching devices. Critical to this realization is the availability of affordable, high quality, large diameter SI and N+ SiC substrates for production of GaN and SiC power semiconductors. SiC is unique in that bulk single crystals cannot be grown via traditional melt-based manufacturing processes such as Czochralski. Rather, a high temperature sublimation process is required. In the late 1980’s, pioneering physical vapor transport research taking place at North Carolina State University ultimately led to the formation of Cree Research and subsequently the wide bandgap semiconductor industry. U.S. Department of Defense investment in wide bandgap semiconductor development has easily exceeded $1B spawning the creation of an entirely new industry. During the early 1990’s, SiC physical vapor transport growth development was fraught with perceived insurmountable technical challenges associated with micropipes, polytype conversion, diameter expansion and crystalline defects. Despite these monumental crystal growth technology hurdles, SiC substrates are now manufactured at a cost and quality never thought possible. This article highlights more than 20 years of Air Force Research Laboratory (AFRL) sponsored development with II-VI aimed at positioning itself as a merchant, world-class manufacturer of SiC substrates.
The escalation in ethanol consumption following chronic intermittent ethanol exposure is blunted in mice expressing ethanol-resistant GluN1 or GluN2A NMDA receptor subunits

N-Methyl-d-aspartate receptors (NMDARs) are glutamate-gated ion channels essential for glutamatergic transmission and plasticity. NMDARs are inhibited by acute ethanol and undergo brain region-specific adaptations after chronic alcohol exposure. In previous studies, we reported that knock-in mice expressing ethanol-insensitive GluN1 or GluN2A NMDAR subunits display altered behavioral responses to acute ethanol and genotype-dependent changes in drinking using protocols that do not produce dependence. A key unanswered question is whether the intrinsic ethanol sensitivity of NMDARs also plays a role in determining behavioral adaptations that accompany the development of dependence. To test this, we exposed mice to repeated cycles of chronic intermittent ethanol (CIE) vapor known to produce a robust escalation in ethanol consumption and preference. As expected, wild-type mice showed a significant increase from baseline in ethanol consumption and preference after each of the four weekly CIE cycles. In contrast, ethanol consumption in male GluN2A(A825W) mice was unchanged following cycles 1, 2, and 4 of CIE with a modest increase appearing after cycle 3. Wild-type and GluN2A(A825W) female mice did not show a clear or consistent escalation in ethanol consumption or preference following CIE treatment. In male GluN1(F639A) mice, the increase in ethanol consumption observed with their wild-type littermates was delayed until later cycles of exposure. These results suggest that the acute ethanol sensitivity of NMDARs especially those containing the GluN2A subunit may be a critical factor in the escalation of ethanol intake in alcohol dependence.
Homomorphic Data Concealment Powered by Clifford Geometric Algebra

We propose general-purpose methods for data representation and data concealment via multivector decompositions and a small subset of functions in the three dimensional Clifford geometric algebra. We demonstrate mechanisms that can be explored for purposes from plain data manipulation to homomorphic data processing with multivectors. The wide variety of algebraic representations in Clifford geometric algebra allow us to explore concepts from integer, complex, vector and matrix arithmetic within a single, compact, flexible and yet powerful algebraic structure in order to propose novel homomorphisms. Our constructions can be incorporated into existing applications as add-ons as well as used to provide standalone data-centric algorithms. We implement our representation and concealment mechanisms in the Ruby programming language to demonstrate the ideas discussed in this work.
Empirical approach to interpreting card-sorting data

Since it was first published 30 years ago, the seminal paper of Chi et al. on expert and novice categorization of introductory problems led to a plethora of follow-up studies within and outside of the area of physics [Cogn. Sci. 5, 121 (1981)]. These studies frequently encompass ``card-sorting'' exercises whereby the participants group problems. While this technique certainly allows insights into problem solving approaches, simple descriptive statistics more often than not fail to find significant differences between experts and novices. In moving beyond descriptive statistics, we describe a novel microscopic approach that takes into account the individual identity of the cards and uses graph theory and models to visualize, analyze, and interpret problem categorization experiments. We apply these methods to an introductory physics (mechanics) problem categorization experiment, and find that most of the variation in sorting outcome is not due to the sorter being an expert versus a novice, but rather due to an independent characteristic that we named ``stacker'' versus ``spreader.'' The fact that the expert-novice distinction only accounts for a smaller amount of the variation may explain the frequent null results when conducting these experiments.
The role of astrocytes in the nucleus tractus solitarii in maintaining central control of autonomic function

The nucleus tractus solitarii (nTS) is the first central site for the termination and integration of autonomic and respiratory sensory information. Sensory afferents terminating in the nTS as well as the embedded nTS neurocircuitry release and utilize glutamate that is critical for maintenance of baseline cardiorespiratory parameters and initiating cardiorespiratory reflexes, including those activated by bouts of hypoxia. nTS astrocytes contribute to synaptic and neuronal activity through a variety of mechanisms, including gliotransmission and regulation of glutamate in the extracellular space via membrane-bound transporters. Here, we aim to highlight recent evidence for the role of astrocytes within the nTS and their regulation of autonomic and cardiorespiratory processes under normal and hypoxic conditions.
Millimeter Wave Frequency Synthesizer Based on Integrated Photonics

Stable and frequency tunable millimeter wave (MMW) signals are important for a variety of applications. MMW synthesizer is a powerful tool for generating high-frequency MMW signals traceable to a low-frequency reference. We introduce a MMW synthesizer design based on microresonator soliton dual-comb photomixing. Allan deviation of the 100 GHz to 300 GHz signals is below 3×10−12 at 1 s averaging time. For example, 251 GHz MMW signal with signal-to-noise ratio of 73 dB is generated. We also demonstrate frequency tuning of 150 GHz signal with step of 1 GHz and 3 Hz. Finally, as the first step towards to on-chip integration, we design an integrated dual-comb generator. The proposed scheme may have great potential for future low-power chip-scale MMW synthesizers.
Computed Tomography Angiography and Magnetic Resonance Angiography of the Carotids

Duplex ultrasonography is usually the initial study used to evaluate carotid artery disease. It provides an accurate noninvasive tool to determine the degree of carotid stenosis and plaque morphology. Although this study has a high sensitivity and specificity, it is an operator-dependent study.
Amphiphilic Distyrylbenzene Derivatives as Potential Therapeutic and Imaging Agents for Soluble and Insoluble Amyloid β Aggregates in Alzheimer's Disease

Alzheimer's Disease (AD) is the most common neurodegenerative disease, and efficient therapeutic and early diagnostic agents for AD are still lacking. Herein, we report the development of a novel amphiphilic compound, LS-4, generated by linking a hydrophobic amyloid-binding distyrylbenzene fragment with a hydrophilic triazamacrocycle, which dramatically increases the binding affinity toward various amyloid β (Aβ) peptide aggregates, especially for soluble Aβ oligomers. Moreover, upon the administration of LS-4 to 5xFAD mice, fluorescence imaging of LS-4-treated brain sections reveals that LS-4 can penetrate the blood-brain barrier and bind to the Aβ oligomers in vivo. In addition, the treatment of 5xFAD mice with LS-4 reduces the amount of both amyloid plaques and associated phosphorylated tau aggregates vs the vehicle-treated 5xFAD mice, while microglia activation is also reduced. Molecular dynamics simulations corroborate the observation that introducing a hydrophilic moiety into the molecular structure of LS-4 can enhance the electrostatic interactions with the polar residues of the Aβ species. Finally, exploiting the Cu2+-chelating property of the triazamacrocycle, we performed a series of imaging and biodistribution studies that show the 64Cu-LS-4 complex binds to the amyloid plaques and can accumulate to a significantly larger extent in the 5xFAD mouse brains vs the wild-type controls. Overall, these results illustrate that the novel strategy, to employ an amphiphilic molecule containing a hydrophilic moiety attached to a hydrophobic amyloid-binding fragment, can increase the binding affinity for both soluble and insoluble Aβ aggregates and can thus be used to detect and regulate various Aβ species in AD.
A Case of Pre-Existing Pregnancy During an In-Vitro Fertilization Cycle.

Serum progesterone levels performed prior to oocyte pick-up is commonly used to guide embryo transfer in in-vitro fertilization (IVF) cycles, as elevated levels can negatively influence pregnancy outcomes. However, levels associated with normal pregnancies should trigger clinicians to consider alternative causes such as a pre-existing pregnancy. We report a case of a 37-year-old patient who underwent controlled ovarian hyperstimulation in a gonadotrophin-releasing hormone antagonist cycle while having an undetected early pregnancy. No oocytes were retrieved at oocyte retrieval despite adequate follicular responses. Her serum progesterone level on the day of her trigger injection was 57.8 nmol/L. She was found to have a pregnancy of unknown location, detected 3 weeks after her oocyte retrieval and was subsequently treated with systemic methotrexate. J Med Cases. 2021;12(9):369-372 doi: https://doi.org/10.14740/jmc3752
Key stakeholder perspectives on obstacles to an autism-specific Medicaid waiver service delivery model

Background Children and youth with autism spectrum disorder have significant, multi-system needs that require supports, such as the autism waiver (AW) service delivery model. This study aimed to identify and describe characteristics of the AW, define obstacles and strengths in the provision of adequate services and provide recommendations for improving overall effectiveness. Methods This mixed-methods exploratory study used an electronic survey to gain information and perceptions of AW provider agency directors (n = 27) and service coordinators (n = 30). Results The key barriers reported were the shortage of qualified staff, inadequate staff training, complexity of cases or symptom severity of clients and lack of communication at multiple levels throughout the agency as well as with parents. Conclusions Recommendations include reinforcing the workforce through higher salaries, greater training and communication interventions. These strategies may reduce staff turnover and shortage, lighten the caseload, reduce the waitlist period and improve the effectiveness and responsiveness of AW services.
Impact of Stereotactic MR-Guided Adaptive Radiation Therapy on Early Clinical and Dosimetric Outcomes in Patients With Pancreatic Cancer.

PURPOSE/OBJECTIVE(S) Dose escalated stereotactic body radiotherapy (SBRT) may improve both local control and overall survival for patients with pancreatic cancer. However, escalated dose cannot be routinely offered because of the risk of injury to adjacent normal organs. Stereotactic magnetic resonance (MR)-guided adaptive radiation therapy (SMART) represents an innovation that may achieve safer delivery of ablative doses and improve outcomes. The goal of the present study is to identify specific dosimetric gains that can be achieved with MR-guided adaptive pancreatic SBRT and describe acute clinical outcomes. MATERIALS/METHODS We performed a single institution IRB approved retrospective analysis of 37 consecutive pancreatic cancer patients treated with 40 Gy in 5 fractions with SMART on a MR-linear accelerator using a light inspiration breath hold. The adaptive workflow starts with an "original" plan which is then adapted daily based on anatomical variation for each fraction. "Predicted" plan dosimetry is generated for each fraction by re-calculating the original plan on the re-contoured pre-treatment anatomy, estimating what would have been delivered without adaptive capabilities. A "re-optimized" plan is developed based on the anatomy of the day to improve target coverage and meet critical organ-at-risk (OAR) metrics, including stomach, duodenum, large bowel and small bowel V33 < 1cc. Acute GI toxicity rates were assessed according to CTCAE v5. RESULTS The median age of our cohort was 71 (range 35-87) with 23/37 (62%) patients having locally advanced disease and 14/37 (38%) having borderline resectable disease. Adaptive planning was used in all cases with a prescription goal of 40 Gy in 5 fractions prescribed to 90% of the target volume. The median CTV was 80.5 cc (range, 10-180cc) and the PTV was a 3mm expansion. Adaptive planning was required in 156/185 fractions to meet either the stomach (63.8%), duodenum (33.5%), large bowel (12.4%) or small bowel (11.4%) V33 < 1cc metric. Of the plans adapted for OAR sparing, 90 plans required adaptation for one gastrointestinal organ, 50 plans for two, 10 plans for three and 1 plan for four. For predicted plans exceeding the V33 < 1cc metric, the median V33 for duodenum was 2.475cc (range: 1.01-10.68cc), stomach was 2.67cc (range: 1.01-8.21cc), small bowel was 2.71cc (range: 1.14-9.54cc) and large bowel was 1.93cc (range: 1.05-8.36cc). All re-optimized plans met the V33 < 1cc metric. No local failure or acute grade 3 toxicities were observed with a median follow-up of 6 months (range 3-15). CONCLUSION Online adaptive re-optimization was necessary for the majority of fractions and improved plan dosimetry was achieved specifically for duodenum, stomach, large and small bowel, achieving low rates of acute toxicity. The clinical benefits of MR-guided adaptive pancreatic SBRT for dose escalation warrant further investigation.
Electron Microscopic Studies on Fuchs' Combined Dystrophy : II. Anterior Portion of the Cornea

Anterior portions of the central corneas of Fuchs' combined dystrophy were studied with the electron microscope, with the use of the same corneal buttons as in Part I of this study 6 , in which changes of the posterior portions were reported. The epithelium showed various grades of cellular edema, mostly in the basal layer. Some of the edematous cells appeared to burst and coalesce to form subepithelial bullae. Possibly as a result, together with proliferation of epithelial cells, marked undulations of the epithelial base and "epithelial quasi islands" toith fissures were formed. Intercellular spaces with desmosomes were usually closed and tight •junctions of the surface layer could be seen as in the controls. Alterations of the subepithelial region paralleled or followed the epithelial changes. Cells appeared in this region at an early stage. Serial sections showed these to come from the anterior stroma. Later, active fibroblasts and collagen fibrils increased, forming large subepithelial masses of connective tissue. These filled all spaces between the irregular epithelial base mentioned above and Bowman's layer, including the fissures separating the epithelial quasi islands. At a later stage fibroblasts became inactive and fewer and the collagen fibrils became thicker. Alterations of Bowman's layer and stroma were less marked, although some changes were seen in the stroma as compared with normal controls. All this indicates that the changes in the anterior cornea in Fuchs' dystrophy are secondary to the involvement of the posterior portions tohich were discussed in Part I, and that the subepithelial alterations are to form a subepithelial connective tissue. Development of anterior bullous changes may be largely dependent upon the balance between the barrier function of the posterior banded region of Descemet's membrane and dysfunction of the altered endothelium.