Presumed PDF Modeling of Early Flame Propagation in Moderate to Intense Turbulence Environments

The present paper describes the results obtained from a one-dimensional time dependent numerical technique that simulates early flame propagation in a moderate to intense turbulent environment. Attention is focused on the development of a spark-ignited, premixed, lean methane/air mixture with the unsteady spherical flame propagating in homogeneous and isotropic turbulence. A Monte-Carlo particle tracking method, based upon the method of fractional steps, is utilized to simulate the phenomena represented by a probability density function (PDF) transport equation. Gaussian distributions of fluctuating velocity and fuel concentration are prescribed. Attention is focused on three primary parameters that influence the initial flame kernel growth: the detailed ignition system characteristics, the mixture composition, and the nature of the flow field. The computational results of moderate and intense isotropic turbulence suggests that flames within the distributed reaction zone are not as vulnerable, as traditionally believed, to the adverse effects of increased turbulence intensity. It is also shown that the magnitude of the flame front thickness significantly impacts the turbulent consumption flame speed. Flame conditions studied have fuel equivalence ratio s in the range phi = 0.6 to 0.9 at standard temperature and pressure

Microgeographic Population Genetic Structure of Baylisascaris Procyonis (Nematoda: Ascaroidae) in Western Michigan Indicates the Grand River is a Barrier to Gene Flow

We developed eight polymorphic microsatellites from the parasitic nematode Baylisascaris procyonis. Amplification of these loci in a sample of 74 worms collected from 10 raccoons in Western Michigan revealed significant population structure. Bayesian clustering indicates two subpopulations, one on either side of the Grand River which bisects the region sampled. Estimates of FST, and results from AMOVA and isolation by distance, further corroborate a scenario whereby the river is acting as a barrier to gene flow, a rather unusual finding given the high vagility of raccoons and microgeographic scale of the analysis. We describe one possible mechanism for how this pattern of structure could have become established

From Mirrors to Wallpapers: A Virtual Math Circle Module on Symmetry

Symmetry is a natural property that children see in their everyday lives; it also has deep mathematical connections to areas like tiling and objects like wallpaper groups. The Tucson Math Circle (TMC) presents a 7-part module on symmetry that starts with reflective symmetry and culminates in the deconstruction of wallpapers into their ‘generating tiles’. This module utilizes a scaffolded, hands-on approach to cover old and new mathematical topics with various interactive activities; all activities are made available through free web-based platforms. In this paper, we provide lesson plans for the various activities used, and discuss their online implementation with Zoom, Miro, and the TMC Widget. We touch on the benefits and disadvantages of the online environment, and provide suggestions for moving these activities to an in-person format. We also include links to files in our Google Drive, where members of the Math Circle community can download our worksheets and Miro board templates

Constraints on Mars Aphelion Cloud Belt Phase Function and Ice Crystal Geometries

This study constrains the lower bound of the scattering phase function of Martian water ice clouds (WICs) through the implementation of a new observation aboard the Mars Science Laboratory (MSL). The Phase Function Sky Survey (PFSS) was a multiple pointing all-sky observation taken with the navigation cameras (Navcam) aboard MSL. The PFSS was executed 35 times during the Aphelion Cloud Belt (ACB) season of Mars Year 34 over a solar longitude range of L_s=61.4{\deg}-156.5{\deg}. Twenty observations occurred in the morning hours between 06:00 and 09:30 LTST, and 15 runs occurred in the evening hours between 14:30 and 18:00 LTST, with an operationally required 2.5 hour gap on either side of local noon due the sun being located near zenith. The resultant WIC phase function was derived over an observed scattering angle range of 18.3{\deg} to 152.61{\deg}, normalized, and compared with 9 modeled phase functions: seven ice crystal habits and two Martian WIC phase functions currently being implemented in models. Through statistical chi-squared probability tests, the five most probable ice crystal geometries observed in the ACB WICs were aggregates, hexagonal solid columns, hollow columns, plates, and bullet rosettes with p-values greater than or equal to 0.60, 0.57,0.56,0.56, and 0.55, respectively. Droxtals and spheres had p-values of 0.35, and 0.2, making them less probable components of Martian WICs, but still statistically possible ones. Having a better understanding of the ice crystal habit and phase function of Martian water ice clouds directly benefits Martian climate models which currently assume spherical and cylindrical particles.Comment: Accepted Manuscript by Planetary and Space Scienc

Utilization of alkyne bioconjugations to modulate protein function

The ability to introduce or modify protein function has widespread application to multiple scientific disciplines. The introduction of unique unnatural amino acids represents an excellent mechanism to incorporate new functionality; however, this approach is limited by ability of the translational machinery to recognize and incorporate the chemical moiety. To overcome this potential limitation, we aimed to exploit the functionality of existing unnatural amino acids to perform bioorthogonal reactions to introduce the desired protein modification, altering its function. Specifically, via the introduction of a terminal alkyne containing unnatural amino acid, we demonstrated chemically programmable protein modification through the Glaser-Hay coupling to other terminal alkynes, altering the function of a protein. In a proof-of-concept experiment, this approach has been utilized to modify the fluorescence spectrum of green fluorescent protein. (C) 2016 Elsevier Ltd. All rights reserved

Emotion Regulation and Positive Affect in the Context of Salivary Alpha-Amylase Response to Pain in Children with Cancer: Physiology, Self-Report, and Behavior

Children with cancer are repeatedly exposed to aversive stimuli including painful procedures. Therefore, emotional regulation techniques may prove useful during such experiences and contribute to pain resilience. This study aimed to determine whether three different emotional regulation strategies (distraction, reappraisal and reassurance) impacted physiological, self- reported and behavioral pain responses in pediatric patients with cancer ages 6 to 18 years (N = 73). The cold pressor task (CPT), an experimental task in which pain is induced by having participants place their hand in cold water, was used to examine pain responses. Patients placed their hand in 7 degree Celsius water for up to 4 minutes. Saliva samples were collected 15 minutes before, immediately after, and then 15 minutes after the CPT. Saliva samples were assayed for alpha amylase, a proxy for sympathetic nervous system activation. Self-reported pain severity was measured upon hand removal. Pain tolerance was assessed by length of time participants kept their hand in the water. Children in the reassurance condition exhibited salivary alpha amylase levels that continued to rise post completion of the CPT as compared to children in the distraction (Beta = -1.68, SE = 0.73, z = -2.30, p = .021, 95% CI [-3.10, -0.25]) and reappraisal (Beta = -1.24, SE = 0.72, z = -1.73, p = .084, 95% CI [-2.65, 0.17]) conditions. However, when self-reported pain and behavior were examined, no differences in pain severity (Wald Chi-squared (2) = 2.47, p = .292), or pain tolerance (Wald Chi-squared (2) = 1.38, p = 0.502) among the emotional regulation strategies were observed. Thus, significant findings were present for physiological markers of distress, but not for self-reported and behavioral measures. These findings suggest that in terms of physiological measures, specific emotional regulation strategies, such as distraction and reappraisal, may be more beneficial in reducing stress responses to painful medical procedures in pediatric patients with cancer as compared to reassurance. These results also demonstrate the importance of examining physiological outcomes in addition to self-report and behavioral outcomes

Cyprus' image—a sun and sea destination—as a detrimental factor to seasonal fluctuations. Exploration into motivational factors for holidaying in Cyprus

Cyprus is established as a summer destination. To aid the destination in developing its winter season as well, this research uses a qualitative inductive approach to explore the tourists’ current image of the island and their motivations of visiting it. The research indicates that the current image, which essentially portrays Cyprus as a sun-and-sea destination is thought to dissuade tourists from perceiving the island as a year-round destination. Nonetheless, increasing the pull factors of the destination through the development of unique special interest products can help in extending the tourism season as well as broaden its narrow image

CXC chemokines in angiogenesis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141036/1/jlb0001.pd