2,019 research outputs found
Detection of Methyl Radicals in a Flat Flame by Degenerate Four-Wave Mixing
We report the spatially resolved detection of methyl radicals in a methane–air f lat flame, using degenerate four-wave mixing (DFWM). A frequency-tripled dye laser pumped with a frequency-doubled Nd:YAG laser was used to access the Herzberg b1 band of methyl near 216 nm. Using a nearly phase-conjugate geometry, we detected methyl with high spatial resolution [0.2 mm (0.3 mm) vertical (horizontal) and ,6 mm longitudinal] and with good signal-to-noise ratio in a rich sf _ 1.55d flame. Compared with laser absorption spectra, DFWM spectra were much less influenced by a broad featureless background. From the absorption data, we measured the peak methyl concentration to be 650 parts in 106, resulting in an estimated DFWM detection limit of 65 parts in 106.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86762/1/Sick48.pd
Systematic perturbation approach for a dynamical scaling law in a kinetically constrained spin model
The dynamical behaviours of a kinetically constrained spin model
(Fredrickson-Andersen model) on a Bethe lattice are investigated by a
perturbation analysis that provides exact final states above the nonergodic
transition point. It is observed that the time-dependent solutions of the
derived dynamical systems obtained by the perturbation analysis become
systematically closer to the results obtained by Monte Carlo simulations as the
order of a perturbation series is increased. This systematic perturbation
analysis also clarifies the existence of a dynamical scaling law, which
provides a implication for a universal relation between a size scale and a time
scale near the nonergodic transition.Comment: 17 pages, 7 figures, v2; results have been refined, v3; A figure has
been modified, v4; results have been more refine
Dependence of Deodorant Usage on ABCC11 Genotype:Scope for Personalized Genetics in Personal Hygiene
Earwax type and axillary odor are genetically determined by rs17822931, a single-nucleotide polymorphism (SNP) located in the ABCC11 gene. The literature has been concerned with the Mendelian trait of earwax, although axillary odor is also Mendelian. Ethnic diversity in rs17822931 exists, with higher frequency of allele A in east Asians. Influence on deodorant usage has not been investigated. In this work, we present a detailed analysis of the rs17822931 effect on deodorant usage in a large (N∼17,000 individuals) population cohort (the Avon Longitudinal Study of Parents and Children (ALSPAC)). We found strong evidence (P=3.7 × 10(−20)) indicating differential deodorant usage according to the rs17822931 genotype. AA homozygotes were almost 5-fold overrepresented in categories of never using deodorant or using it infrequently. However, 77.8% of white European genotypically nonodorous individuals still used deodorant, and 4.7% genotypically odorous individuals did not. We provide evidence of a behavioral effect associated with rs17822931. This effect has a biological basis that can result in a change in the family's environment if an aerosol deodorant is used. It also indicates potential cost saving to the nonodorous and scope for personalized genetics usage in personal hygiene choices, with consequent reduction of inappropriate chemical exposures for some
Vertical Jump Performance as a Discriminator of Playing Ability in Collegiate Female Soccer Players
Previous studies have assessed the importance of physical characteristics to soccer playing ability by comparing performance-based outcomes between starters and non-starters. Starters are often considered the most skilled players on the team. These players get more playing time than non-starters and have been shown to achieve higher performance outcomes on intermittent fitness tests. However, it remains unclear whether starters can achieve higher performance outcomes on a countermovement vertical jump. PURPOSE: The purpose of this study was to investigate the efficacy of countermovement vertical jump height and peak power to discriminate between starters and non-starters in collegiate female soccer. METHODS: Twenty-seven collegiate female soccer players (age = 19.56 ± 1.28 years; height = 164.26 ± 5.74 cm; body mass = 66.65 ± 8.43 kg) were recruited to participate in the present study. All testing was completed during the 2021 preseason training period. The players were classified as starters (n = 12) or non-starters (n = 15) according to their average number of minutes played per game during the subsequent exhibition season. Each participant reported to the laboratory for a single visit where they performed three countermovement vertical jump tests on a jump mat. For each jump, participants stood on the mat with feet shoulder width apart and hands positioned on the hips. Participants were not allowed to take any steps prior to performing the vertical jump and a quick descending quarter-squat countermovement was allowed before the ascending takeoff phase. The participants were instructed to jump as explosively as possible with both feet at the same time and land on the jump mat in the starting position. Vertical jump height (cm) was estimated from the flight time recorded by the jump mat. Peak power output was estimated using a previously validated regression equation: peak power (W) = 51.9 × vertical jump height (cm) + 48.9 × body mass (kg) - 2007. Independent samples t-tests were used to compare vertical jump height and peak power between the starting and non-starting groups. RESULTS: Vertical jump height was significantly greater (P = 0.039) for the starters (38.60 ± 6.11 cm) compared to the non-starters (34.43 ± 3.75 cm). There was no significant difference (P = 0.448) between the starters (3076.72 ± 331.98 W) and non-starters (3182.23 ± 369.67 W) for peak power. CONCLUSION: These findings suggest that vertical jump height is an effective measure for discriminating between starters and non-starters in collegiate female soccer. Vertical jump characteristics are critical to a player’s performance on the field. Because the starters in this study were able to jump higher than the non-starters, vertical jump height may be an important parameter for identifying players with a high degree of soccer playing ability
Epithelial mesenchymal transition (EMT): a universal process in lung diseases with implications for cystic fibrosis pathophysiology
Cystic Fibrosis (CF) is a genetic disorder that arises due to mutations in the Cystic Fibrosis Transmembrane Conductance Regulator gene, which encodes for a protein responsible for ion transport out of epithelial cells. This leads to a disruption in transepithelial Cl-, Na + and HCO3- ion transport and the subsequent dehydration of the airway epithelium, resulting in infection, inflammation and development of fibrotic tissue. Unlike in CF, fibrosis in other lung diseases including asthma, chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis has been well characterised. One of the driving forces behind fibrosis is Epithelial Mesenchymal Transition (EMT), a process where epithelial cells lose epithelial proteins including E-Cadherin, which is responsible for tight junctions. The cell moves to a more mesenchymal phenotype as it gains mesenchymal markers such as N-Cadherin (providing the cells with migration potential), Vimentin and Fibronectin (proteins excreted to help form the extracellular matrix), and the fibroblast proliferation transcription factors Snail, Slug and Twist. This review paper explores the EMT process in a range of lung diseases, details the common links that these have to cystic fibrosis, and explores how understanding EMT in cystic fibrosis may open up novel methods of treating patients with cystic fibrosis.Nathan Rout-Pitt, Nigel Farrow, David Parsons and Martin Donnelle
Predicted waiting times for orthopaedic surgery : an urgent need to address the deficit in capacity
The authors received no financial or material support for the research, authorship, and/or publication of this article.Peer reviewedPublisher PD
Death receptor 3 regulates distinct pathological attributes of acute versus chronic murine allergic lung inflammation
The Death Receptor 3 (DR3)/Tumour Necrosis Factor-like cytokine 1A (TL1A) axis stimulates effector T cells and type 2 innate lymphocytes (ILC2) that trigger cytokine release and drive disease pathology in several inflammatory and autoimmune diseases, including murine models of acute allergic lung inflammation (ALI). The aim of this study was to elucidate the role of DR3 in chronic ALI compared to acute ALI, using mice genetically deficient in the DR3 gene (DR3ko). Results showed DR3 expression in the lungs of wild-type mice was up-regulated following induction of acute ALI and this increased expression was maintained in chronic disease. DR3ko mice were resistant to cellular accumulation within the alveolar passages in acute, but not chronic ALI. However, DR3ko mice displayed reduced immuno-histopathology and goblet cell hyperplasia; hallmarks of the asthmatic phenotype; in chronic, but not acute ALI. These data suggest DR3 is a potential therapeutic target, involved in temporally distinct aspects of ALI progression and pathogenesis
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