Shear Stabilization of a Solidifying Front

The manufacturing of multi-component single crystals with uniform material properties is frequently hampered by the presence of morphological instabilities during the solidification. We discuss the influence of shear flows on the linear and nonlinear stability of the solid/liquid interface during the directional solidification of binary alloys. The flows are generated by nonplanar harmonic translations of the crystal parallel to the mean interface position. Oscillations with physically realizable amplitudes and frequencies are found useful for stabilization purposes

Integral field spectroscopy of nearby QSOs II. The molecular gas content and condition for star formation

We present single-dish 12CO(1 − 0) and 12CO(2 − 1) observations for 14 low-redshift quasi-stellar objects (QSOs). In combination with optical integral field spectroscopy we study how the cold gas content relates to the star formation rate (SFR) and black hole accretion rate. 12CO(1 − 0) is detected in 8 of 14 targets and 12CO(2 − 1) is detected in 7 out of 11 cases. The majority of disc-dominated QSOs reveal gas fractions and depletion times well matching normal star forming systems. Two gas-rich major mergers show clear starburst signatures with higher than average gas fractions and shorter depletion times. Bulge-dominated QSO hosts are mainly undetected in 12CO(1 − 0) which corresponds, on average, to lower gas fractions than in disc-dominated counterparts. Their SFRs however imply shorter than average depletion times and higher star formation efficiencies. Negative QSO feedback through removal of cold gas seems to play a negligible role in our sample. We find a trend between black hole accretion rate and total molecular gas content for disc-dominated QSOs when combined with literature samples. We interpret this as an upper envelope for the nuclear activity and is well represented by a scaling relation between the total and circum-nuclear gas reservoir accessible for accretion. Bulge-dominated QSOs significantly differ from that scaling relation and appear uncorrelated with the total molecular gas content. This could be explained either by a more compact gas reservoir, blow out of the gas envelope through outflows, or a different ISM phase composition

Live-Fly, Large-Scale Field Experimentation for Large Numbers of Fixed-Wing UAVs

In this paper, we present extensive advances in live-fly field experimentation capabilities of large numbers of fixed-wing aerial robots, and highlight both the enabling technologies as well as the challenges addressed in such large-scale flight operations. We showcase results from recent field tests, including the autonomous launch, flight, and landing of 50 UAVs, which illuminate numerous operational lessons learned and generate rich multi-UAV datasets. We detail the design and open architecture of the testbed, which intentionally leverages low-cost and open-source components, aimed at promoting continued advances and alignment of multi-robot systems research and practice

Geographic Disparity of Female Athlete Triad Awareness and Access to Resources in the NCAA

The Female Athlete Triad is a pervasive, multifactorial morbidity among college athletes. The geographic disparity of female athlete triad awareness and access to resources in NCAA is unknown. PURPOSE: To determine geographic disparities in awareness of Triad components and resource access in the National Collegiate Athletic Association (NCAA). METHOD: Division I-III NCAA compliance officers were sent an email containing a request to disseminate a web-based survey to cross country coaches in their respective conferences. The web-linked instrument included: a study synopsis; an informed consent statement, and; the IRB-approved survey tool. Respondents were grouped geographically based upon conference headquarters location, regions included; Northeast, Midwest, South, and West. Statistical analysis, using JMP software, included frequency distributions and chi-square tests for categorical association. RESULTS: Coaches (n = 143; age = 40.7 ± 11.9 years; coaching experience = 14.1 ± 10.3 years) from 45 conferences participated. Location impacted coaches’ awareness of the term “female athlete triad” (p = 0.0183), which was highest in the West (90%), and; lowest in the South (74%). Geography did not influence Triad component recognition (p = 0.3907) (i.e. low energy availability, amenorrhea, low bone mineral density), however; only 54% of coaches correctly identified all Triad components. Coaches who had Triad awareness were more likely to possess understanding that menstrual irregularities are not a normal result of exercise (p = \u3c0.001). No relationship was identified between location and access to body composition technology (p = 0.2031), or; a registered dietician (p = 0.4869). However, only 30% and 53% of coaches had access to these biometric and dietetic resources, respectively. Western cross-country athletes (p = 0.0276) had the highest access to sport psychologists (50%); lowest access was in the Midwest (20%). CONCLUSION: Triad awareness and geographic resource disparities exist: Western coaches have a higher level of Triad awareness and superior access to psychological counseling, whereas; the South and Midwest had the lowest, respectively. Greater uniform access to resources amongst NCAA schools, regardless of geographic region, may positively impact Triad prevalence and outcomes

2018 – 2019 Kentucky Agricultural Economic Situation and Outlook

This publication covers the situation and outlook for 2018-2019 in the following areas: U.S. Agricultural Economy; Kentucky’s Agricultural Economy; Selected Commodity Profiles - Cattle; Poultry; Hogs; Equine; Dairy; Corn; Soybeans; Wheat; Tobacco; Fruits, Vegetables and Greenhouse; and Forestry

A single and rapid calcium wave at egg activation in Drosophila.

Activation is an essential process that accompanies fertilisation in all animals and heralds major cellular changes, most notably, resumption of the cell cycle. While activation involves wave-like oscillations in intracellular Ca(2+) concentration in mammals, ascidians and polychaete worms and a single Ca(2+) peak in fish and frogs, in insects, such as Drosophila, to date, it has not been shown what changes in intracellular Ca(2+) levels occur. Here, we utilise ratiometric imaging of Ca(2+) indicator dyes and genetically encoded Ca(2+) indicator proteins to identify and characterise a single, rapid, transient wave of Ca(2+) in the Drosophila egg at activation. Using genetic tools, physical manipulation and pharmacological treatments we demonstrate that the propagation of the Ca(2+) wave requires an intact actin cytoskeleton and an increase in intracellular Ca(2+) can be uncoupled from egg swelling, but not from progression of the cell cycle. We further show that mechanical pressure alone is not sufficient to initiate a Ca(2+) wave. We also find that processing bodies, sites of mRNA decay and translational regulation, become dispersed following the Ca(2+) transient. Based on this data we propose the following model for egg activation in Drosophila: exposure to lateral oviduct fluid initiates an increase in intracellular Ca(2+) at the egg posterior via osmotic swelling, possibly through mechano-sensitive Ca(2+) channels; a single Ca(2+) wave then propagates in an actin dependent manner; this Ca(2+) wave co-ordinates key developmental events including resumption of the cell cycle and initiation of translation of mRNAs such as bicoid.This work was supported by the University of Cambridge, ISSF to T.T.W. [grant number 097814]; and Wellcome Trust Senior Research Fellowship to I.D. [grant number 096144].This is the final version of the article. It first appeared from the Company of Biologists via http://dx.doi.org/10.1242/bio.20141129

2016 – 2017 Kentucky Agricultural Economic Situation and Outlook

Topics: U.S. Agricultural Economy; Kentucky’s Agricultural Economy