Vine and Fruit Responses to Supplementary Irrigation and Canopy Management

Drip irrigation at 0.0, 0.2 or 0.4 of weekly Class A Pan evaporation was applied to grapevines cv. Shiraz in the Barossa Valley of South Australia. Irrigation resulted in a significant increase in yield and vegetative growth but also significantly changed wine composition and wine spectral measures. Canopy management by shoot positioning and treatment with ethephon, both designed to increase fruit exposure to sunlight, resulted in significant but small changes in wine quality measures. The implications of these treatments for the improvement of wine quality from irrigated vines are discussed

Postsecondary Re-Entry Programs: Examining Outcomes of Nontraditional Learners of Color

The narratives of nontraditional adult learners of color are explored to understand what contributes to the social, behavioral, and academic outcomes of nontraditional adult learners enrolled in a postsecondary reentry program at a Midwest university. An instrumental case study will capture participants' varied experiences in this program to understand whether student outcomes are affected by their enrollment in the designated postsecondary reentry program. Examining the research from this perspective will provide context into the institutions' role in the success of nontraditional learners of color.Doctor of Education (EdD)College of Education, Health, & Human ServicesUniversity of Michigan-Dearbornhttp://deepblue.lib.umich.edu/bitstream/2027.42/167727/1/Eric McCloud Dissertation Final.pdfDescription of Eric McCloud Dissertation Final.pdf : Dissertatio

Class, race and ethnicity and information avoidance among cancer survivors

Background: Information seeking may increase cancer survivors' ability to make decisions and cope with the disease, but many also avoid cancer information after diagnosis. The social determinants and subsequent communication barriers that lead to avoidance have not been explored. The purpose of this study is to examine the influence of social determinants on information avoidance among cancer survivors. Methods: We examined how health information avoidance is associated with structural and individual factors in a mail-based survey of 519 cancer survivors. Factor analysis was conducted to determine barriers to obtaining cancer information, and multivariable logistic regression models by gender were run to analyze social determinants of avoidance from an intersectional approach. Results: Participants who were younger, female, had greater debt and lower income, and had difficulty finding suitable information were more likely to avoid information. The probability of information avoidance increased when survivors reported barriers to information use or comprehension. Conclusion: These results indicate that survivors' information avoidance may be driven, in part, by social determinants, particularly among those at the intersection of multiple social status categories. Customized strategies are needed that maximize the likelihood that information will be used by vulnerable groups such as those from a lower socioeconomic position

Effectiveness of a Mobile App Intervention for Anxiety and Depression Symptoms in University Students: Randomized Controlled Trial

Background: Depression and anxiety symptoms are common among university students, but many do not receive treatment. This is often because of lack of availability, reluctance to seek help, and not meeting the diagnostic criteria required to access services. Internet-based interventions, including smartphone apps, can overcome these issues. However, a large number of apps are available, each with little evidence of their effectiveness. / Objective: This study aims to evaluate for the first time the effectiveness of a self-guided mobile app, Feel Stress Free, for the treatment of depression and anxiety symptoms in students. / Methods: A web-based randomized controlled trial compared a cognitive behavioral therapy (CBT)–based mobile app Feel Stress Free with a wait-list control. University students self-identified as experiencing symptoms of anxiety or depression and were randomized to 6 weeks of intervention (n=84) or control (n=84), unblinded. The app is self-guided and incorporates behavioral relaxation activities, mood tracking and thought challenging, and minigames. Participants completed the Hospital Anxiety and Depression Scale online at baseline and every fortnight. / Results: At week 6, the primary end point, there was evidence that the Feel Stress Free app reduced depression symptoms (mean difference −1.56; 95% CI −2.67 to −0.44; P=.006) but only very weak evidence that it reduced anxiety symptoms (mean difference −1.36; 95% CI −2.93 to 0.21; P=.09). At week 4, there was evidence to support the effectiveness of the intervention for anxiety symptoms (mean difference −1.94; 95% CI −3.11 to −0.77; P=.001) and, though weaker, depression symptoms (mean difference −1.08; 95% CI −2.12 to −0.04; P=.04). At week 6, 83% (34/41) of participants indicated that they were using the app weekly or more frequently. / Conclusions: The Feel Stress Free app is a promising mobile intervention for treating symptoms of anxiety and depression in students and overcomes many of the barriers to traditional CBT. Further research is needed to establish its effectiveness at and beyond 6 weeks. / Trial Registration: ClinicalTrials.gov NCT03032952; https://clinicaltrials.gov/ct2/show/NCT0303295

Parallel flow in Hele-Shaw cells with ferrofluids

Parallel flow in a Hele-Shaw cell occurs when two immiscible liquids flow with relative velocity parallel to the interface between them. The interface is unstable due to a Kelvin-Helmholtz type of instability in which fluid flow couples with inertial effects to cause an initial small perturbation to grow. Large amplitude disturbances form stable solitons. We consider the effects of applied magnetic fields when one of the two fluids is a ferrofluid. The dispersion relation governing mode growth is modified so that the magnetic field can destabilize the interface even in the absence of inertial effects. However, the magnetic field does not affect the speed of wave propagation for a given wavenumber. We note that the magnetic field creates an effective interaction between the solitons.Comment: 12 pages, Revtex, 2 figures, revised version (minor changes

Quasiperiodic Tip Splitting in Directional Solidification

We report experimental results on the tip splitting dynamics of seaweed growth in directional solidification of succinonitrile alloys with poly(ethylene oxide) or acetone as solutes. The seaweed or dense branching morphology was selected by solidifying grains which are oriented close to the {111} plane. Despite the random appearance of the growth, a quasiperiodic tip splitting morphology was observed in which the tip alternately splits to the left and to the right. The tip splitting frequency f was found to be related to the growth velocity V as a power law f V^{1.5}. This finding is consistent with the predictions of a tip splitting model that is also presented. Small anisotropies are shown to lead to different kinds of seaweed morphologies.Comment: 4 pages, 7 figures, submitted to Physical Review Letter

Gravity-driven instability in a spherical Hele-Shaw cell

A pair of concentric spheres separated by a small gap form a spherical Hele-Shaw cell. In this cell an interfacial instability arises when two immiscible fluids flow. We derive the equation of motion for the interface perturbation amplitudes, including both pressure and gravity drivings, using a mode coupling approach. Linear stability analysis shows that mode growth rates depend upon interface perimeter and gravitational force. Mode coupling analysis reveals the formation of fingering structures presenting a tendency toward finger tip-sharpening.Comment: 13 pages, 4 ps figures, RevTex, to appear in Physical Review

Viscous fingering in liquid crystals: Anisotropy and morphological transitions

We show that a minimal model for viscous fingering with a nematic liquid crystal in which anisotropy is considered to enter through two different viscosities in two perpendicular directions can be mapped to a two-fold anisotropy in the surface tension. We numerically integrate the dynamics of the resulting problem with the phase-field approach to find and characterize a transition between tip-splitting and side-branching as a function of both anisotropy and dimensionless surface tension. This anisotropy dependence could explain the experimentally observed (reentrant) transition as temperature and applied pressure are varied. Our observations are also consistent with previous experimental evidence in viscous fingering within an etched cell and simulations of solidification.Comment: 12 pages, 3 figures. Submitted to PR

Rotating Hele-Shaw cells with ferrofluids

We investigate the flow of two immiscible, viscous fluids in a rotating Hele-Shaw cell, when one of the fluids is a ferrofluid and an external magnetic field is applied. The interplay between centrifugal and magnetic forces in determining the instability of the fluid-fluid interface is analyzed. The linear stability analysis of the problem shows that a non-uniform, azimuthal magnetic field, applied tangential to the cell, tends to stabilize the interface. We verify that maximum growth rate selection of initial patterns is influenced by the applied field, which tends to decrease the number of interface ripples. We contrast these results with the situation in which a uniform magnetic field is applied normally to the plane defined by the rotating Hele-Shaw cell.Comment: 12 pages, 3 ps figures, RevTe