3,201 research outputs found
A Primer on Laplacian Dynamics in Directed Graphs
We analyze the asymptotic behavior of general first order Laplacian processes
on digraphs. The most important ones of these are diffusion and consensus with
both continuous and discrete time. We treat diffusion and consensus as dual
processes. This is the first complete exposition of this material in a single
work.Comment: 24 pages, 5 figures, summer-school/conference on mathematical
modeling of complex systems in Pescara, 201
Potential Commercial Applications from Combustion and Fire Research in Space
The near-zero (microgravity) environment of orbiting spacecraft minimizes buoyant flows, greatly simplifying combustion processes and isolating important phenomena ordinarily concealed by the overwhelming gravity-driven forces and flows. Fundamental combustion understanding - the focus to date of the NASA microgravity-combustion program - has greatly benefited from analyses and experiments conducted in the microgravity environment. Because of the economic and commercial importance of combustion in practice, there is strong motivation to seek wider applications for the microgravity-combustion findings. This paper reviews selected technology developments to illustrate some emerging applications. Topics cover improved fire-safety technology in spacecraft and terrestrial systems, innovative combustor designs for aerospace and ground propulsion, applied sensors and controls for combustion processes, and self-sustaining synthesis techniques for advanced materials
Identification of the Genomic Insertion Site of the Thyroid Peroxidase Promoter–Cre Recombinase Transgene Using a Novel, Efficient, Next-Generation DNA Sequencing Method
Background: It can be useful to know the transgene insertion site in transgenic mice for a variety of reasons, but determining the insertion site generally is a time consuming, expensive, and laborious task. Methods: A simple method is presented to determine transgene insertion sites that combines the enrichment of a sequencing library by polymerase chain reaction (PCR) for sequences containing the transgene, followed by next-generation sequencing of the enriched library. This method was applied to determine the site of integration of the thyroid peroxidase promoter?Cre recombinase mouse transgene that is commonly used to create thyroid-specific gene deletions. Results: The insertion site was found to be between bp 12,372,316 and 12,372,324 on mouse chromosome 9, with the nearest characterized genes being Cntn5 and Jrkl, ?1.5 and 0.9?Mbp from the transgene, respectively. One advantage of knowing a transgene insertion site is that it facilitates distinguishing hemizygous from homozygous transgenic mice. Although this can be accomplished by real-time quantitative PCR, the expected Ct difference is only one cycle, which is challenging to assess accurately. Therefore, the transgene insertion site information was used to develop a 3-primer qualitative PCR assay that readily distinguishes wild type, hemizygous, and homozygous TPO-Cre mice based upon size differences of the wild type and transgenic allele PCR products. Conclusions: Identification of the genomic insertion site of the thyroid peroxidase promoter?Cre mouse transgene should facilitate the use of these mice in studies of thyroid biology.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140267/1/thy.2015.0215.pd
Scaled Quail Reproduction in the Trans-Pecos Region of Texas
Scaled quail (Callipepla squamata) populations have declined markedly throughout their range. We monitored hatch rates and nest placement of radio-marked female scaled quail (n 1⁄4 210) in Pecos County, Texas relative to the availability and location of ‘spreader dams’ (i.e., shallow water catchments) through the nesting seasons of 1999 and 2000. Hatch rates were high both years (i.e., 67 and 84% for 1999 and 2000, respectively). The predominant nesting microhabitat was tobosa (Pleuraphis mutica), which accounted for 85% of the nests located. We failed to document any direct impacts of spreader dams on nesting ecology of scaled quail
Quantification of global myocardial oxygenation in humans: initial experience
<p>Abstract</p> <p>Purpose</p> <p>To assess the feasibility of our newly developed cardiovascular magnetic resonance (CMR) methods to quantify global and/or regional myocardial oxygen consumption rate (MVO<sub>2</sub>) at rest and during pharmacologically-induced vasodilation in normal volunteers.</p> <p>Methods</p> <p>A breath-hold T<sub>2 </sub>quantification method is developed to calculate oxygen extraction fraction (OEF) and MVO<sub>2 </sub>rate at rest and/or during hyperemia, using a two-compartment model. A previously reported T<sub>2 </sub>quantification method using turbo-spin-echo sequence was also applied for comparison. CMR scans were performed in 6 normal volunteers. Each imaging session consisted of imaging at rest and during adenosine-induced vasodilation. The new T<sub>2 </sub>quantification method was applied to calculate T<sub>2 </sub>in the coronary sinus (CS), as well as in myocardial tissue. Resting CS OEF, representing resting global myocardial OEF, and myocardial OEF during adenosine vasodilation were then calculated by the model. Myocardial blood flow (MBF) was also obtained to calculate MVO<sub>2</sub>, by using a first-pass perfusion imaging approach.</p> <p>Results</p> <p>The T<sub>2 </sub>quantification method yielded a hyperemic OEF of 0.37 ± 0.05 and a hyperemic MVO<sub>2 </sub>of 9.2 ± 2.4 μmol/g/min. The corresponding resting values were 0.73 ± 0.05 and 5.2 ± 1.7 μmol/g/min respectively, which agreed well with published literature values. The MVO<sub>2 </sub>rose proportionally with rate-pressure product from the rest condition. The T<sub>2 </sub>sensitivity is approximately 95% higher with the new T<sub>2 </sub>method than turbo-spin-echo method.</p> <p>Conclusion</p> <p>The CMR oxygenation method demonstrates the potential for non-invasive estimation of myocardial oxygenation, and should be explored in patients with altered myocardial oxygenation.</p
Important Updates to Submission Types in Topics in Exercise Science and Kinesiology
Topics in Exercise Science and Kinesiology Volume 2: Issue 1, Article 1, 2021. While Topics in Exercise Science and Kinesiology (TESK) was originally designed to fill a void in publishing applied information for practitioners in physical activity and sport, the TESK editors have determined a need to update the submission categories. The categories of Process of Science and Implementation Strategies have been retained, and three new types of submissions now will be accepted: Expedited Articles, Review Articles, and Case Studies. Process of Science submissions should seek to answer the question, “What was learned from the experience of performing the investigation?”, while Implementation Strategies should address, “How can what was carried out be explained?” Required elements for both submission types are outlined along with guidelines for conducting peer-reviews. Expedited Articles can be submitted to TESK and undergo an accelerated review by the editors. Required elements and the peer review processes are also outlined for Review Articles and Case Studies
Method and Apparatus for Non-Destructive Evaluation of Materials
Methods and apparatus for characterizing composite materials for manufacturing quality assurance (QA), periodic inspection during the useful life, or for forensic analysis/material testing. System are provided that relate eddy-current sensor responses to the fiber layup of a composite structure, the presence of impact damage on a composite structure with or without a metal liner, volumetric stress within the composite, fiber tow density, and other NDE inspection requirements. Also provided are systems that determine electromagnetic material properties and material dimensions of composite materials from capacitive sensor inspection measurements. These properties are related to the presence of buried defects in non-conductive composite materials, moisture ingress, aging of the material due to service or environmental/thermal exposure, or changes in manufacturing quality
Guidelines for Reviewers: Topics in Exercise Science and Kinesiology
The purpose of this document is to serve as a guide for evaluators who agree to review work submitted to Topics in Exercise Science and Kinesiology. To assist evaluators, a Reviewer Rubric has been created with the following sections: Title Page and Abstract, Introduction and Methods Page, Point of Application Page(s), Other Considerations, and Reviewer Decisions. Point of application: Reviewing the Title and Abstract page – rubric shared for title, author list, affiliations, the abstract, and key words. Point of application: Reviewing the Introduction and Methods page – evaluation of introductory paragraph, paragraph for methodology and/or results. Point of application: Reviewing the Point of Application pages – rubric for Each Point of Application, which should consist of a title, written text, and a figure or table. Point of application: Reviewing the Figures and Tables, and Making a Decision – rubric for the evaluation of figures or tables, others comments, and decisions that can be made
Assessing Causes of Change in the Freshwater Mussels (Bivalvia: Unionidae) in the Black River, Ohio
Habitat destruction is believed to be the number one cause of the decline in unionid mussels. Around the world, cities, towns and agriculture alter the structure of watersheds, and the Black River in Ohio may be a typical example. We investigated the diversity and abundance of unionid mussels in this watershed and compared results to urbanization locations, to site-specific appearance of the habitat and to a 1997 fish survey, as host species are another factor important to the distribution of unionid mussels. Although shells were found for 21 species, only 11 of these species were found alive. Seven of the species represented only by shells occurred only in the urbanized lower main stem of the river and less than five shells were found for each. Most of these shells were old and worn. Furthermore, the present assemblage in the main stem varied from shells obtained at a nearby archeological site, and from a voucher set of species obtained at the turn of the 20th Century. Mussel communities higher in the river and those in tributaries were less diverse, but abundance of the species present was higher than in the main stem. A lack of fish hosts may limit mussel diversity, as hosts for several species present in the main stem do not reside higher in the watershed. Overall, mussel assemblages in the Black River appear typical for the region with relatively abundant, but low diversity communities upstream of the cities that line Lake Erie\u27s coast and diverse, but small and potentially threatened, populations in the urban regions
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