1,833 research outputs found

    Simulated Fire Behavior and Fine-Scale Forest Structure Following Conifer Removal in Aspen-Conifer Forests in the Lake Tahoe Basin, USA

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    Quaking aspen is found in western forests of the United States and is currently at risk of loss due to conifer competition at within-stand scales. Wildfires in these forests are impactful owing to conifer infilling during prolonged fire suppression post-Euro-American settlement. Here, restoration cuttings seek to impact wildfire behavior and aspen growing conditions. In this study, we explored how actual and hypothetical cuttings with a range of conifer removal intensity altered surface fuel and overstory structure at stand and fine scales. We then simulated wildfires, examining fire behavior and effects on post-fire forest structures around aspen trees. We found that conifer removal constrained by lower upper diameter limits (\u3c56 cm) had marginal effects on surface fuel and overstory structure, likely failing to enhance resource conditions sufficiently to sustain aspen. Increasing the diameter limit also led to a higher likelihood of fire spread and a higher rate of spread, owing to greater within-canopy wind speed, though crown fire activity decreased. Our simulations suggest heavier treatments could facilitate reintroduction of fire while also dampening the effects of wildfires on forest structure. Cutting specifications that relax diameter limits and remove a substantial portion of conifer overstory could better promote aspen restoration and mitigate fire hazard

    Fluency Assistance Device (FAD): Masker Upgrades

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    There are around seventy million people internationally who have a stutter, a form of fluency disorder. Some fluency assistance devices are available to the public, but most are highly expensive or unreliable. The Fluency Assistive Device (FAD) team seeks to assist a niche community of these individuals for whom therapy has not worked, and who currently rely on a device known as the Edinburgh Masker. To best reach this community, FAD is partnering with Dave Germeyer, who has invaluable experience repairing these masker devices for his clientele. FAD is redesigning the masker to increase its portability, functionality, and cost-effectiveness by developing an improved analog and new digital version. The Analog Masker v1.3 focuses on updated components and consolidated circuitry to eliminate troublesome wiring of the original. The Digital Masker v1.0 employs a Bluetooth-enabled microcontroller to achieve masker functionality, offering the flexibility of alternative fluency assistance algorithms to assist a broader group of users. An updated prototype of the Analog Masker v1.3 was fabricated and tested for power consumption and overall functional output characteristics versus the original Edinburgh version. The Analog Masker v1.3 has also been fully packaged and enclosed to produce a client testable unit. Bluetooth audio output for the Digital Masker has almost been completed, and two of the alternative algorithms have been coded for the masking output. One of these algorithms, Delayed Altered Feedback (DAF), now produces the expected output in response to an audio test input. Clarity and integrity of the DAF signal output have also been improved. The Masking Altered Feedback (MAF) algorithm that emulates the behavior of the Edinburgh original on the Digital Masker v1.0 is under development. Funding for this work provided by The Collaboratory for Strategic Partnerships and Applied Research.https://mosaic.messiah.edu/engr2022/1006/thumbnail.jp

    Fluency Assistance Device (FAD): Masker Upgrades

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    Around seventy million people internationally have a stutter, a form of a fluency disorder. Some fluency assistance devices are available to the public, but most are highly expensive or unreliable. The Fluency Assistive Device (FAD) team seeks to assist a niche community of these individuals who currently rely on a device known originally as the Edinburgh Masker by partnering with Dave Germeyer. Utilizing his expertise in repairing the Edinburgh Masker, FAD is developing two new versions of the masker to increase its portability, functionality, and cost-effectiveness. The first is an update of the original called the Analog Masker (Version 1.1). A prototype of the Analog Masker v1.1 has been developed, tested and is currently being revised based on the results. Revisions include updating the layout of the board and finalizing the power supply circuitry. The second version, known as the Digital Masker (Version 1.0), will use a Bluetooth-enabled microcontroller to achieve masker functionality. Bluetooth audio output for the Digital Masker has been tested, and two algorithms have been created for the masking output. The supporting software for the Digital Masker is nearing completion. The schematic and the layout design have been started for future implementation of the hardware.https://mosaic.messiah.edu/engr2021/1005/thumbnail.jp

    Value-Driven Analysis of New Paradigms in Space Architectures: An Ilities-Based Approach

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    Current commercial, civil, and military space architecture designs perform exquisitely and reliably. However, today’s architecture paradigms are also characterized by expensive launches, large and expensive high-performance spacecraft, long development cycles, and wide variations in ground architectures. While current assets provide high-quality services, and future assets are slated to improve performance within the same design frameworks, proposed future architectures may not be capitalizing on technology improvements, system innovations, or policy alternatives explored during the last two decades. This paper identifies five “trends” along which space architectures may develop, aimed at granting systems several “ilities,” such as resiliency, robustness, flexibility, scalability, and affordability. The trends examined include: commercialization of space, significant reductions in launch costs and the development of hybrid or reusable launch systems, development of on-orbit infrastructure and servicing, aggregation or disaggregation of orbital assets, and the automation and standardization of ground architectures. Further refinement of these key technological and system trends could result in major paradigm shifts in the development and fielding of space operations as well as lead to space architecture designs in the future that are radically different from those today. Within the framework of systems engineering ilities and risk management, this paper reviews current literature surrounding these new change trends and justifies their potential to cause significant paradigm shifts. By examining the work and research conducted so far through an ilities-based approach, systems engineers can more fully appreciate the value being offered by these trends

    Genotype determination for polymorphisms in linkage disequilibrium

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    <p>Abstract</p> <p>Background</p> <p>Genome-wide association studies with single nucleotide polymorphisms (SNPs) show great promise to identify genetic determinants of complex human traits. In current analyses, genotype calling and imputation of missing genotypes are usually considered as two separated tasks. The genotypes of SNPs are first determined one at a time from allele signal intensities. Then the missing genotypes, i.e., no-calls caused by not perfectly separated signal clouds, are imputed based on the linkage disequilibrium (LD) between multiple SNPs. Although many statistical methods have been developed to improve either genotype calling or imputation of missing genotypes, treating the two steps independently can lead to loss of genetic information.</p> <p>Results</p> <p>We propose a novel genotype calling framework. In this framework, we consider the signal intensities and underlying LD structure of SNPs simultaneously by estimating both cluster parameters and haplotype frequencies. As a result, our new method outperforms some existing algorithms in terms of both call rates and genotyping accuracy. Our studies also suggest that jointly analyzing multiple SNPs in LD provides more accurate estimation of haplotypes than haplotype reconstruction methods that only use called genotypes.</p> <p>Conclusion</p> <p>Our study demonstrates that jointly analyzing signal intensities and LD structure of multiple SNPs is a better way to determine genotypes and estimate LD parameters.</p

    Cefuroxime Pharmacokinetics in Pediatric Cardiovascular Surgery Patients Undergoing Cardiopulmonary Bypass

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    Objectives The objective of this study was to determine the pharmacokinetics of cefuroxime in children undergoing cardiopulmonary bypass (CPB) for cardiovascular surgery. Design A prospective study. Setting A tertiary pediatric teaching hospital. Participants Infants and children undergoing CPB were enrolled in the study. Intervention An initial dose (mean, 24.2 ± 1.6 mg/kg) of cefuroxime was administered before surgical incision, and a second dose (mean, 14.4 ± 7.9 mg/kg) was administered in the CPB prime solution. Serial blood samples were obtained before, during, and after the CPB process. Samples were shipped on dry ice to the analytic laboratory and concentrations determined by a validated high-performance liquid chromatography method. A 2-compartment pharmacokinetic model was fitted to the data using maximum a priori–Bayesian estimation, with weight as a covariate. Monte Carlo simulations of a single-dose (25 mg/kg pre-CPB) approach and a 2-dose (25 mg/kg pre- and 12.5-mg/kg prime solution dose) approach were performed. Measurements and Main Results Fifteen subjects (9 males/6 females) were enrolled in the study, with median (range) age and weight of 11 (3-34) months and 9.5 (4.5-15.4) kg, respectively. The median (range) duration of CPB was 136 (71-243) minutes. Median and range cefuroxime pharmacokinetic parameters were as follows: maximum concentration (Cmax) dose, 1: 328 (150-512) μg/mL; systemic clearance, 0.050 (0.041-0.058) L/h/kg; steady-state volume of distribution, 0.213 (0.081-0.423) L/kg; volume of distribution in the central compartment, 0.081 (0.046-0.162) L/kg; and elimination half-life, 3.76 (1.03-6.81) hours. The median 8-hour post–dose-simulated cefuroxime concentrations were 26.5 and 16.0 mg/L for the 2-dose and single-dose regimens, respectively. Conclusion Manufacturers recommend that pediatric doses of cefuroxime (25-50 mg/kg) can be used in infants and children undergoing CPB to maintain adequate serum concentrations for surgical-site infection prophylaxis. A second intraoperative dose, administered through the CPB circuit, provides no additional prophylactic advantage

    Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

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    This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin

    Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

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    Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts

    Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas

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    Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN

    The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

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    The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected
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