1,292 research outputs found
Following red blood cells in a pulmonary capillary
The red blood cells or erythrocytes are biconcave shaped cells and consist
mostly in a membrane delimiting a cytosol with a high concentration in
hemoglobin. This membrane is highly deformable and allows the cells to go
through narrow passages like the capillaries which diameters can be much
smaller than red blood cells one. They carry oxygen thanks to hemoglobin, a
complex molecule that have very high affinity for oxygen. The capacity of
erythrocytes to load and unload oxygen is thus a determinant factor in their
efficacy. In this paper, we will focus on the pulmonary capillary where red
blood cells capture oxygen. We propose a camera method in order to numerically
study the behavior of the red blood cell along a whole capillary. Our goal is
to understand how erythrocytes geometrical changes along the capillary can
affect its capacity to capture oxygen. The first part of this document presents
the model chosen for the red blood cells along with the numerical method used
to determine and follow their shapes along the capillary. The membrane of the
red blood cell is complex and has been modelled by an hyper-elastic approach
coming from Mills et al (2004). This camera method is then validated and
confronted with a standard ALE method. Some geometrical properties of the red
blood cells observed in our simulations are then studied and discussed. The
second part of this paper deals with the modeling of oxygen and hemoglobin
chemistry in the geometries obtained in the first part. We have implemented a
full complex hemoglobin behavior with allosteric states inspired from
Czerlinski et al (1999).Comment: 17 page
Observations on the Red Ratsnake / Cornsnake
This is where the abstract of this record would appear. This is only demonstration data
Bridging the Gap: Motivations, Challenges, and Successes of Veteran Entrepreneurs
This exploratory study seeks to better understand veterans\u27 business journey experience. As a result, this research study spans several areas of the business ownership, including finances, mentorships and networks, educational and learning styles, and challenges/barriers. Helpful for anyone who seeks an awareness of the veteran entrepreneurship industry
Calibration of low-level laser therapy equipment
CONTEXTUALIZAÇÃO: A laserterapia de baixa intensidade (LBI) vem sendo cada vez mais utilizada, porém ainda não há consenso na literatura quanto ao tempo em que os equipamentos devem ser submetidos à aferição ou calibragem. OBJETIVO: Analisar a potência média real (PmR) dos equipamentos de LBI na região da Grande São Paulo. MÉTODOS: Para análise dos equipamentos, utilizou-se um potenciômetro (Lasercheck), próprio para aferição de equipamentos contínuos, o qual foi programado com dados referentes ao comprimento de onda do laser a ser avaliado, obtendo-se assim a PmR emitida. Os equipamentos foram analisados de duas formas: uma, com o LBI desaquecido, e outra, após 10 minutos de uso (aquecido), sendo que três análises foram feitas para cada condição. A caneta emissora foi acoplada ao potenciômetro, o qual fornecia a PmR emitida pelo LBI. Todos os dados e informações referentes à aplicação do laser foram coletados por um questionário respondido pelos responsáveis. RESULTADOS: Os 60 equipamentos avaliados mostraram déficit na PmR com os equipamentos desaquecidos e aquecidos. A análise estatística (ANOVA) mostrou diminuição significativa (P<0,05) da PmR aferida em relação à potência média do fabricante (PmF). Em média, a dose mais empregada nas clínicas foi de 4 J/cm², tendo os efeitos de cicatrização e anti-inflamatório como os mais desejados. Segundo a World Association for Laser Therapy (WALT), para atingir esse efeito, necessita-se de 1 a 4 J de energia final, sendo que apenas um dos 60 aparelhos conseguiria atingir a janela terapêutica preconizada. CONCLUSÃO: Os equipamentos de LBI apresentam um déficit acentuado na PmR, o que mostra uma desordem na utilização desse recurso. Neste estudo, observou-se a necessidade de aferição periódica dos aparelhos de LBI bem como melhor conhecimento técnico dos profissionais envolvidos.BACKGROUND: Despite the increase in the use of low-level laser therapy (LLLT), there is still a lack of consensus in the literature regarding how often the equipment must be calibrated. OBJECTIVE: To evaluate the real average power of LLLT devices in the Greater São Paulo area. METHODS: For the evaluation, a LaserCheck power meter designed to calibrate continuous equipment was used. The power meter was programmed with data related to the laser's wavelength to gauge the real average power being emitted. The LLLT devices were evaluated in two ways: first with the device cooled down and then with the device warmed up for 10 minutes. For each condition, three tests were performed. The laser probe was aligned with the power meter, which provided the real average power being emitted by the LLLT device. All of the data and information related to the laser application were collected with the use of a questionnaire filled in by the supervising therapists. RESULTS: The 60 devices evaluated showed deficit in real average power in the cooled-down and warmed-up condition. The statistical analysis (ANOVA) showed a significant decrease (p<0.05) in the real average power measured in relation to the manufacturer's average power. On average, the most common dose in the clinics was 4 J/cm², and the most desired effects were healing and anti-inflammatory effects. According to the World Association for Laser Therapy (WALT), 1 to 4 J of final energy are necessary to achieve these effects, however only one device was able to reach the recommended therapeutic window. CONCLUSION: The LLLT devices showed a deficit in real average power that emphasized a lack of order in the application of this tool. The present study also showed the need for periodical calibration of LLLT equipment and a better technical knowledge of the therapists involved
Spectral analysis of Gene co-expression network of Zebrafish
We analyze the gene expression data of Zebrafish under the combined framework
of complex networks and random matrix theory. The nearest neighbor spacing
distribution of the corresponding matrix spectra follows random matrix
predictions of Gaussian orthogonal statistics. Based on the eigenvector
analysis we can divide the spectra into two parts, first part for which the
eigenvector localization properties match with the random matrix theory
predictions, and the second part for which they show deviation from the theory
and hence are useful to understand the system dependent properties. Spectra
with the localized eigenvectors can be characterized into three groups based on
the eigenvalues. We explore the position of localized nodes from these
different categories. Using an overlap measure, we find that the top
contributing nodes in the different groups carry distinguished structural
features. Furthermore, the top contributing nodes of the different localized
eigenvectors corresponding to the lower eigenvalue regime form different
densely connected structure well separated from each other. Preliminary
biological interpretation of the genes, associated with the top contributing
nodes in the localized eigenvectors, suggests that the genes corresponding to
same vector share common features.Comment: 6 pages, four figures (accepted in EPL
Advancing Veteran Success in Higher Education: Case Highlights of Veteran-Friendly Programs at Professional Schools at Syracuse University
Made possible through support from the Graduate Management Admission Council (GMAC),this paper highlights findings from schools at Syracuse University. The goal of this study and paper is twofold: to identify challenges and best practices with creating, recruiting, and sustaining veteran-friendly programming and initiatives and to share recommendations for other schools and college campuses on how to become more veteran-friendly, with particular emphasis on addressing the needs of today’s student veteran
Enhancing Resource Management through Prediction-based Policies
Task-based programming models are emerging as a promising alternative to make
the most of multi-/many-core systems. These programming models rely on runtime
systems, and their goal is to improve application performance by properly
scheduling application tasks to cores. Additionally, these runtime systems
offer policies to cope with application phases that lack in parallelism to fill
all cores. However, these policies are usually static and favor either
performance or energy efficiency. In this paper, we have extended a task-based
runtime system with a lightweight monitoring and prediction infrastructure that
dynamically predicts the optimal number of cores required for each application
phase, thus improving both performance and energy efficiency. Through the
execution of several benchmarks in multi-/many-core systems, we show that our
prediction-based policies have competitive performance while improving energy
efficiency when compared to state of the art policies.Comment: Postprint submitted and published at Euro-Par2020: International
European Conference on Parallel and Distributed Computing (Springer)
(https://link.springer.com/chapter/10.1007%2F978-3-030-57675-2_31
Two-way multi-lane traffic model for pedestrians in corridors
We extend the Aw-Rascle macroscopic model of car traffic into a two-way
multi-lane model of pedestrian traffic. Within this model, we propose a
technique for the handling of the congestion constraint, i.e. the fact that the
pedestrian density cannot exceed a maximal density corresponding to contact
between pedestrians. In a first step, we propose a singularly perturbed
pressure relation which models the fact that the pedestrian velocity is
considerably reduced, if not blocked, at congestion. In a second step, we carry
over the singular limit into the model and show that abrupt transitions between
compressible flow (in the uncongested regions) to incompressible flow (in
congested regions) occur. We also investigate the hyperbolicity of the two-way
models and show that they can lose their hyperbolicity in some cases. We study
a diffusive correction of these models and discuss the characteristic time and
length scales of the instability
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