The relationship between different email management strategies and the perceived control of time

Time management research, and the psychological construct of perceived control of time, are drawn on to investigate populist claims of the virtues of regularly filing and organising ones electronic mail. Using a process model of time management, it would seem that filing of email may increase ones time control perceptions and thus their job satisfaction and wellbeing. One hundred and sixty five participants were involved in a questionnaire-based field study. Analyses of variance revealed that for some e-mail users, not having a filing system may result in a high perceived control of time. Furthermore, challenging assumptions regarding optimal e-mail organisation, those that tried to frequently file their incoming messages, but did so somewhat unsuccessfully, had significantly less perceived control of time. These results highlight individual differences in control of time perceptions, and recommendations are made regarding organisational e-mail behaviour and training

Is 5-Hydroxymethylcytosine a Suppressor or Activator in Epigenetic Marks?

poster abstractAlcohol has been observed to have teratogenic effects on humans and mice during different stages of embryonic development. These effects can be condensed under fetal alcohol spectrum disorder (FASD), exhibiting a variety of signs from growth retardations to neurobehavioral aberrations. Despite better understanding of several potential mechanisms, the question of how alcohol, as an environmental factor leads to brain growth delay in FASD remains elusive. DNA methylation is key to development and tissue specification. Studies have suggested that alcohol may alter gene expression by affecting DNA and histone methylation. Previous studies have demonstrated that 5-methylcytosine (5mC), a DNA methylation mark, is associated with histone 3 lysine-9me3, (H3K9me3) to play a role in gene repression. Recently another methylation mark, 5hydroxylmethylcytosine (5hmC), was found to prevail in the nervous system. However, its function has not been clear. Global analysis suggests that it is a transition of demethylation leading to transcription. The study will first identify its association with histone 3 lysine-4me3, (H3K4me3) a transcriptional activator in gene expression, and then study the 5hmC under influence of alcohol exposure. This study will utilize both an in vivo model—the vapor chamber, and an in vitro model—the embryonic culture system to address this question. Embryos were exposed to alcohol (400mg/dL, 88mM) from the beginning of embryonic day (E) 8 for 6hrs, harvested at E10, and processed for immunohistochemistry. Compare the DNA methylation marks, and histone modification marks to see if the spatial and/or temporal distribution has been affected by alcohol exposure. It is expected that in the alcohol-treated embryos, an overall retardation of embryonic growth, delayed neural tube formation, and altered expression of epigenetic markers will be observed. This study could indicate that alcohol, through alteration of DNA and histone methylation is a potential mechanism underpinning brain growth delay in FASD

The Navier-Stokes-alpha model of fluid turbulence

We review the properties of the nonlinearly dispersive Navier-Stokes-alpha (NS-alpha) model of incompressible fluid turbulence -- also called the viscous Camassa-Holm equations and the LANS equations in the literature. We first re-derive the NS-alpha model by filtering the velocity of the fluid loop in Kelvin's circulation theorem for the Navier-Stokes equations. Then we show that this filtering causes the wavenumber spectrum of the translational kinetic energy for the NS-alpha model to roll off as k^{-3} for k \alpha > 1 in three dimensions, instead of continuing along the slower Kolmogorov scaling law, k^{-5/3}, that it follows for k \alpha < 1. This rolloff at higher wavenumbers shortens the inertial range for the NS-alpha model and thereby makes it more computable. We also explain how the NS-alpha model is related to large eddy simulation (LES) turbulence modeling and to the stress tensor for second-grade fluids. We close by surveying recent results in the literature for the NS-alpha model and its inviscid limit (the Euler-alpha model).Comment: 22 pages, 1 figure. Dedicated to V. E. Zakharov on the occasion of his 60th birthday. To appear in Physica

The Impact Of Different Lateral Size Of Graphene Oxide On The Performance Of The Emulsified Acrylate-Based Pour Point Depressant And Its Application In Crude Oil

The different lateral size of GOs were obtained through ultrasonication method at 0 min, 10 min, 30 min, 60 min and 100 min. The SEM results shows that the longer the ultrasonication time, the smaller the average lateral size of the GO nanosheets. The results from FTIR is used to shows the presence of the oxygen functional group in the GO nanosheets after subjected to ultrasonication. The addition of different lateral size GO into the emulsified acrylate-based PPD-GO shows that the acrylate-based droplets size increases, more polydisperse and reduce in zeta potential. However, when the emulsified acrylate PPD-GO is at isothermal and freeze thaw condition, the effect of the different lateral size of the GO after aging not that significant. The rheological measurement shows that 10 min is the optimum ultrasonication time to produce the ideal lateral size of GO nanosheets that leads to improvement in flowabiltiy and stability of the emulsified acrylate-based PPD-GO. Besides, it shows the highest reduction of pour point on the crude oil and improve rheological behaviour of the crude oil in terms of shear stress and viscosity. Exceeding the optimum ultrasonication time, the reducing lateral size of GO will produce negative impact on the flowability and the stability of the emusified acrylate PPD-GO and its performance in crude oil. Lastly, the study on Herschel-Buckley model has proven to be more accurate in prediction of yield stress and fluid behaviour of emulsified acrylate-based PPD-GO compare to crude oil

The glucocorticoid-Angptl4-ceramide axis induces insulin resistance through PP2A and PKCζ.

Chronic glucocorticoid exposure is associated with the development of insulin resistance. We showed that glucocorticoid-induced insulin resistance was attenuated upon ablation of Angptl4, a glucocorticoid target gene encoding the secreted protein angiopoietin-like 4, which mediates glucocorticoid-induced lipolysis in white adipose tissue. Through metabolomic profiling, we revealed that glucocorticoid treatment increased hepatic ceramide concentrations by inducing enzymes in the ceramide synthetic pathway in an Angptl4-dependent manner. Angptl4 was also required for glucocorticoids to stimulate the activities of the downstream effectors of ceramide, protein phosphatase 2A (PP2A) and protein kinase Cζ (PKCζ). We further showed that knockdown of PP2A or inhibition of PKCζ or ceramide synthesis prevented glucocorticoid-induced glucose intolerance in wild-type mice. Moreover, the inhibition of PKCζ or ceramide synthesis did not further improve glucose tolerance in Angptl4-/- mice, suggesting that these molecules were major downstream effectors of Angptl4. Overall, our study demonstrates the key role of Angptl4 in glucocorticoid-augmented hepatic ceramide production that induces whole-body insulin resistance

Nonlinear balance and exchange of stability in dynamics of solitons, peakons, ramps/cliffs and leftons in a 1+1 nonlinear evolutionary PDE

We study exchange of stability in the dynamics of solitary wave solutions under changes in the nonlinear balance in a 1+1 evolutionary partial differential equation related both to shallow water waves and to turbulence. We find that solutions of the equation $m_t + um_x +b u_xm = \nu m_{xx}$ with $m = u - \alpha^2 u_{xx}$ for fluid velocity $u(x,t)$ change their behavior at the special values $b=0,\pm1,\pm2,\pm3$.Comment: 15 pages, 8 figures. For this replacement of the original submission, we: (1) Introduced key explanations that clarify the differences between Figs 1 and 2, versus 3 and 4. (2) Expanded the introduction to provide added motivation and precise definitions. (3) Added section and subsection headings to make the plan of the paper more evident. (4) Added a brief summar

Hyaluronan concentration and size distribution in human knee synovial fluid: variations with age and cartilage degeneration.

BackgroundOne potential mechanism for early superficial cartilage wear in normal joints is alteration of the lubricant content and quality of synovial fluid. The purpose of this study was to determine if the concentration and quality of the lubricant, hyaluronan, in synovial fluid: (1) was similar in left and right knees; (2) exhibited similar age-associated trends, whether collected postmortem or antemortem; and (3) varied with age and grade of joint degeneration.MethodsHuman synovial fluid of donors (23-91 years) without osteoarthritis was analyzed for the concentrations of protein, hyaluronan, and hyaluronan in the molecular weight ranges of 2.5-7 MDa, 1-2.5 MDa, 0.5-1 MDa, and 0.03-0.5 MDa. Similarity of data between left and right knees was assessed by reduced major axis regression, paired t-test, and Bland-Altman analysis. The effect of antemortem versus postmortem collection on biochemical properties was assessed for age-matched samples by unpaired t-test. The relationships between age, joint grade, and each biochemical component were assessed by regression analysis.ResultsJoint grade and the concentrations of protein, hyaluronan, and hyaluronan in the molecular weight ranges of 2.5-7 MDa, 1-2.5 MDa, and 0.5-1 MDa in human synovial fluid showed good agreement between left and right knees and were similar between age-matched patient and cadaver knee joints. There was an age-associated decrease in overall joint grade (-15 %/decade) and concentrations of hyaluronan (-10.5 %/decade), and hyaluronan in the molecular weight ranges of 2.5-7 MDa (-9.4 %/decade), 1-2.5 MDa (-11.3 %/decade), 0.5-1 MDa (-12.5 %/decade), and 0.03-0.5 MDa (-13.0 %/decade). Hyaluronan concentration and quality was more strongly associated with age than with joint grade.ConclusionsThe age-related increase in cartilage wear in non-osteoarthritic joints may be related to the altered hyaluronan content and quality of synovial fluid

Intermittency in the Joint Cascade of Energy and Helicity

The statistics of the energy and helicity fluxes in isotropic turbulence are studied using high resolution direct numerical simulation. The scaling exponents of the energy flux agree with those of the transverse velocity structure functions through refined similarity hypothesis, consistent with Kraichnan's prediction \cite{Kr74}. The helicity flux is even more intermittent than the energy flux and its scaling exponents are closer to those of the passive scalar. Using Waleffe's helical decomposition, we demonstrate that the existence of positive mean helicity flux inhibits the energy transfer in the negative helical modes, a non-passive effect