Wing and body motion during flight initiation in Drosophila revealed by automated visual tracking

The fruit fly Drosophila melanogaster is a widely used model organism in studies of genetics, developmental biology and biomechanics. One limitation for exploiting Drosophila as a model system for behavioral neurobiology is that measuring body kinematics during behavior is labor intensive and subjective. In order to quantify flight kinematics during different types of maneuvers, we have developed a visual tracking system that estimates the posture of the fly from multiple calibrated cameras. An accurate geometric fly model is designed using unit quaternions to capture complex body and wing rotations, which are automatically fitted to the images in each time frame. Our approach works across a range of flight behaviors, while also being robust to common environmental clutter. The tracking system is used in this paper to compare wing and body motion during both voluntary and escape take-offs. Using our automated algorithms, we are able to measure stroke amplitude, geometric angle of attack and other parameters important to a mechanistic understanding of flapping flight. When compared with manual tracking methods, the algorithm estimates body position within 4.4±1.3% of the body length, while body orientation is measured within 6.5±1.9 deg. (roll), 3.2±1.3 deg. (pitch) and 3.4±1.6 deg. (yaw) on average across six videos. Similarly, stroke amplitude and deviation are estimated within 3.3 deg. and 2.1 deg., while angle of attack is typically measured within 8.8 deg. comparing against a human digitizer. Using our automated tracker, we analyzed a total of eight voluntary and two escape take-offs. These sequences show that Drosophila melanogaster do not utilize clap and fling during take-off and are able to modify their wing kinematics from one wingstroke to the next. Our approach should enable biomechanists and ethologists to process much larger datasets than possible at present and, therefore, accelerate insight into the mechanisms of free-flight maneuvers of flying insects

Oral Health Intervention: A Multifaceted Approach to Improve Oral Health Care during Pregnancy

Introduction: Early Childhood Caries (ECC) is the most common chronic disease of childhood Mothers’ oral health status is a strong predictor of the oral health status of their children 2009: Vermont spends $2.7 million treating children ages 0-5 with Early Childhood Caries 2012: Vermont lifts the$495 Medicaid cap on reimbursement for a woman’s dental care during pregnancy and up to 60 days after delivery American College of Obstetrics and Gynecology (ACOG) Guidelines on prenatal dental care are published 2013: 74% of surveyed Vermont providers treating pregnant women are unaware of the Medicaid change 82% of these providers are not using guidelines to assess oral health during pregnancy Objective: To improve prenatal dental referral rates from obstetric providers by facilitating Vermont-specific implementation of ACOG guidelineshttps://scholarworks.uvm.edu/comphp_gallery/1212/thumbnail.jp

Theory of temperature dependence of the Fermi surface-induced splitting of the alloy diffuse-scattering intensity peak

The explanation is presented for the temperature dependence of the fourfold intensity peak splitting found recently in diffuse scattering from the disordered Cu3Au alloy. The wavevector and temperature dependence of the self-energy is identified as the origin of the observed behaviour. Two approaches for the calculation of the self-energy, the high-temperature expansion and the alpha-expansion, are proposed. Applied to the Cu3Au alloy, both methods predict the increase of the splitting with temperature, in agreement with the experimental results.Comment: 4 pages, 3 EPS figures, RevTeX, submitted to J. Phys. Condens. Matter (Letter to the Editor

Writing with Elbow

Peter Elbow is one of those scholars who had such an impact on his field that by mid-career he had already attained icon status. As an early proponent of what became known as process theory, Elbow, with others working along similar lines, developed a powerful body of theory that gradually reoriented instruction in writing toward an emphasis on invention and revision-toward the process of writing as a mode of thinking-and consequently toward a focus on the interaction between writer and audience, instead of on the traditionally conceived product of writing, the text. It is not too much to claim that Peter Elbow, like few others, changed the way writing is taught in America. Writing with Elbow is a volume written by leading scholars now working in the field of composition who trace their own scholarship to foundational work done by Peter Elbow over the last thirty years. The book is in that sense a celebration. But it is more than that, too. Elbow and process writing are not without their critics, and the essays collected in Writing with Elbow also test him, extend his work, explore his intellectual forebears, address his critics and contexts, and complicate his legacy across a wide range of issues in current composition research and practice. A thoughtful, comprehensive retrospective on Peter Elbow\u27s legacy, Writing with Elbow is a must-read collection for composition scholars, teachers, English educationists, and graduate students.https://digitalcommons.usu.edu/usupress_pubs/1132/thumbnail.jp

Detailed Spectroscopic and Photometric Analysis of DQ White Dwarfs

We present an analysis of spectroscopic and photometric data for cool DQ white dwarfs based on improved model atmosphere calculations. In particular, we revise the atmospheric parameters of the trigonometric parallax sample of Bergeron et al.(2001), and discuss the astrophysical implications on the temperature scale and mean mass, as well as the chemical evolution of these stars. We also analyze 40 new DQ stars discovered in the first data release of the Sloan Digital Sky Survey.Comment: 6 pages,3 figures, 14th European Workshop on White Dwarfs, ASP Conference Series, in pres

FUSE observations of G226-29: First detection of the H_2 quasi-molecular satellite at 1150A

We present new FUV observations of the pulsating DA white dwarf G226-29 obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). This ZZ Ceti star is the brightest one of its class and the coolest white dwarf observed by FUSE. We report the first detection of the broad quasi-molecular collision-induced satellite of Ly-beta at 1150 A, an absorption feature that is due to transitions which take place during close collisions of hydrogen atoms. The physical interpretation of this feature is based on recent progress of the line broadening theory of the far wing of Ly-beta. This predicted feature had never been observed before, even in laboratory spectra.Comment: Accepted for publication in ApJ Letters; 6 pages, 3 figure

Oxygen superstructures throughout the phase diagram of (Y,Ca)Ba2Cu3O6+x\bf (Y,Ca)Ba_2 Cu_3 O_{6+x}

Short-range lattice superstructures have been studied with high-energy x-ray diffuse scattering in underdoped, optimally doped, and overdoped $\rm (Y,Ca)Ba_2 Cu_3 O_{6+x}$. A new four-unit-cell superstructure was observed in compounds with $x\sim 0.95$. Its temperature, doping, and material dependence was used to attribute its origin to short-range oxygen vacancy ordering, rather than electronic instabilities in the $\rm CuO_2$ layers. No significant diffuse scattering is observed in YBa$_2$Cu$_4$O$_{8}$. The oxygen superstructures must be taken into account when interpreting spectral anomalies in $\rm (Y,Ca)Ba_2 Cu_3 O_{6+x}$

Charge Order in the Falicov-Kimball Model

We examine the spinless one-dimensional Falicov-Kimball model (FKM) below half-filling, addressing both the binary alloy and valence transition interpretations of the model. Using a non-perturbative technique, we derive an effective Hamiltonian for the occupation of the localized orbitals, providing a comprehensive description of charge order in the FKM. In particular, we uncover the contradictory ordering roles of the forward-scattering and backscattering itinerant electrons: the latter are responsible for the crystalline phases, while the former produces the phase separation. We find an Ising model describes the transition between the phase separated state and the crystalline phases; for weak-coupling we present the critical line equation, finding excellent agreement with numerical results. We consider several extensions of the FKM that preserve the classical nature of the localized states. We also investigate a parallel between the FKM and the Kondo lattice model, suggesting a close relationship based upon the similar orthogonality catastrophe physics of the associated single-impurity models.Comment: 39 pages, 6 figure

Spin projection operators and higher-spin Cotton tensors in three dimensions

We elaborate on the spin projection operators in three dimensions and use them to derive a new representation for the linearised higher-spin Cotton tensors.Comment: 17 pages; V2: references and comments added; V3: typos corrected, reference adde