27 - Effects of temperature during non-breeding months on size of three species of sparrow

Earth’s climate has warmed at an average rate of 0.17°C (0.31°F) per decade since 1970, and many scientists question how birds might adapt to this temperature change. Vertebrate body size likely has been associated with temperature based on two prominent hypotheses. Bergmann’s rule states that body size is larger in cooler climates because larger-bodied animals are better able to maintain stable internal temperatures. Allen’s rule states that appendages are smaller in cooler climates to decrease the amount surface area to lose heat. We hypothesize that as temperatures increase, body mass will decrease and wing chord will increase. We captured 932 swamp sparrows, 794 song sparrows, and 373 field sparrows at Panola Mountain State Park, in Stockbridge, GA between 2007-2017. We recorded the hatch year by back-calculating from age at capture, body mass, and wing chord length. We compared these measurements to the average temperature during non-breeding months at Panola Mountain, obtained from the National Oceanic and Atmospheric Administration database. Swamp sparrows born in warmer years were smaller in eight out of the nine years, as predicted by Bergmann’s rule. Similarly, Swamp sparrows born in warmer years had larger wing chords in eight out of nine years, as predicted by Allen’s rule. Neither Song sparrow nor Field sparrow mass or wing chord length were associated with temperature in any years. Our study shows that Swamp sparrow size may be affected by the temperature during their first winter and may be more susceptible to climate changes than other sparrow species

Online identification and nonlinear control of the electrically stimulated quadriceps muscle

A new approach for estimating nonlinear models of the electrically stimulated quadriceps muscle group under nonisometric conditions is investigated. The model can be used for designing controlled neuro-prostheses. In order to identify the muscle dynamics (stimulation pulsewidth-active knee moment relation) from discrete-time angle measurements only, a hybrid model structure is postulated for the shank-quadriceps dynamics. The model consists of a relatively well known time-invariant passive component and an uncertain time-variant active component. Rigid body dynamics, described by the Equation of Motion (EoM), and passive joint properties form the time-invariant part. The actuator, i.e. the electrically stimulated muscle group, represents the uncertain time-varying section. A recursive algorithm is outlined for identifying online the stimulated quadriceps muscle group. The algorithm requires EoM and passive joint characteristics to be known a priori. The muscle dynamics represent the product of a continuous-time nonlinear activation dynamics and a nonlinear static contraction function described by a Normalised Radial Basis Function (NRBF) network which has knee-joint angle and angular velocity as input arguments. An Extended Kalman Filter (EKF) approach is chosen to estimate muscle dynamics parameters and to obtain full state estimates of the shank-quadriceps dynamics simultaneously. The latter is important for implementing state feedback controllers. A nonlinear state feedback controller using the backstepping method is explicitly designed whereas the model was identified a priori using the developed identification procedure

Processingâ Dependent Microstructure of AgClâ CsAgCl2 Eutectic Photonic Crystals

Directional solidification of a eutectic melt allows control over the resultant eutectic microstructure, which in turn impacts both the mechanical and optical properties of the material. These selfâ organized phaseâ separated eutectic materials can be tuned to have periodicities from tens of micrometers down to nanometers. Furthermore, the two phases possess differences in their refractive index leading to interesting optical properties that can be tailored within the visible to infrared wavelength regime. It is found the binary salt eutectic AgClâ CsAgCl2 system forms a rod microstructure with sample draw rates up to 0.2 mm sâ 1 which transitions to a lamellar microstructure at draw rates greater than 0.36 mm sâ 1. Heatâ transfer simulations reveal a draw rateâ dependent direction of motion of the solidification front, which for a range of draw rates requires nucleation of the minority solid phase at the sample wall. Phaseâ field modeling indicates that the initial eutectic structure at the sample boundary, either rod or lamellar, dictates the bulk eutectic morphology. These samples contain submicrometer periodicities which coupled with their optical transparency results in them exhibiting draw rateâ dependent nearâ IR reflectance peaks consistent with stop bands for 2D hexagonal (rod) and 1D planar (lamellar) photonic crystals.The eutectic composition of the molten salts AgCl and CsCl exhibits a microstructural transition from rod to lamellar upon varying the draw rates controlled by directional solidification. This transition is dominated by the initial formation at the surface of either the rod or lamellar structure. The resultant eutectic microstructures have optical properties consistent with their being 2D and 1D photonic crystals.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145412/1/adom201701316.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145412/2/adom201701316_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145412/3/adom201701316-sup-0001-S1.pd

Fluid flow at the interface between elastic solids with randomly rough surfaces

I study fluid flow at the interface between elastic solids with randomly rough surfaces. I use the contact mechanics model of Persson to take into account the elastic interaction between the solid walls and the Bruggeman effective medium theory to account for the influence of the disorder on the fluid flow. I calculate the flow tensor which determines the pressure flow factor and, e.g., the leak-rate of static seals. I show how the perturbation treatment of Tripp can be extended to arbitrary order in the ratio between the root-mean-square roughness amplitude and the average interfacial surface separation. I introduce a matrix D(Zeta), determined by the surface roughness power spectrum, which can be used to describe the anisotropy of the surface at any magnification Zeta. I present results for the asymmetry factor Gamma(Zeta) (generalized Peklenik number) for grinded steel and sandblasted PMMA surfaces.Comment: 16 pages, 14 figure

Sexual dimorphism of human vallate papillae: an in vivo study of normative morphology

The perimeters of vallate papillae (VP) house approximately half of the taste buds on the human tongue. However, little information exists regarding perimeter measurements of VP. Likewise, great diversity exists among reports of the number of VP and diameter of VP, in general. The research presents an analysis of the perimeters, counts, and diameters of VP in vivo. Endoscopic examination was performed on 79 individuals (40 females, 39 males) between 18 and 26 years of age. A total of 583 VP were counted, 565 of which were able to be measured. Data revealed a statistically significant difference between male and female VP count (t(75.6) = 4.5; p = 0.00003). Females had, on average, 2.22 more VP than males. Males were found to have larger mean VP diameter per person and mean VP perimeter per person than females (t(58.9) = –2.4; p = 0.021 and t(59.3) = –2.4; p = 0.019, respectively). The report demonstrates that VP are sexually dimorphic at the gross anatomical level

Preparing to Participate: An Exploration of Student Engagement through Student Work and Instructors’ Observations

The present study investigates two instructional strategies that promote student preparation for and participation in class: reading objectives and participation sheets. In the first study, students were asked to complete the reading objectives (knowledge level questions about the assigned reading) and write the extended comments. Extended comments move beyond the knowledge level by demonstrating comprehension, application, or evaluation of the content. These include personal examples, insights, or questions about the course material. A content analysis of the students’ ex-tended comments found evidence of student engagement as 76.3% of the comments moved beyond the “knowledge” level. Study 2 examined instructors’ perceptions of student preparation for and participation in class. Instructors were asked to reflect on the differences between their classes that used and did not use the graded participation strategies. Instructors reported that the graded participation strategies resulted in more insightful discussions, a more positive class climate, and more knowledge of their students com-pared to their class sections that did not use these instructional tools