Observations of Outflowing UV Absorbers in NGC 4051 with the Cosmic Origins Spectrograph

We present new Hubble Space Telescope (HST)/Cosmic Origins Spectrograph observations of the Narrow-Line Seyfert 1 galaxy NGC 4051. These data were obtained as part of a coordinated observing program including X-ray observations with the Chandra/High Energy Transmission Grating (HETG) Spectrometer and Suzaku. We detected nine kinematic components of UV absorption, which were previously identified using the HST/Space Telescope Imaging Spectrograph. None of the absorption components showed evidence for changes in column density or profile within the \sim 10 yr between the STIS and COS observations, which we interpret as evidence of 1) saturation, for the stronger components, or 2) very low densities, i.e., n_H < 1 cm^-3, for the weaker components. After applying a +200 km s^-1 offset to the HETG spectrum, we found that the radial velocities of the UV absorbers lay within the O VII profile. Based on photoionization models, we suggest that, while UV components 2, 5 and 7 produce significant O VII absorption, the bulk of the X-ray absorption detected in the HETG analysis occurs in more highly ionized gas. Moreover, the mass loss rate is dominated by high ionization gas which lacks a significant UV footprint.Comment: 41 pages, 10 Figures; accepted for publication in the Astrophysical Journa

Efficient creation of molecules from a cesium Bose-Einstein condensate

We report a new scheme to create weakly bound Cs$_2$ molecules from an atomic Bose-Einstein condensate. The method is based on switching the magnetic field to a narrow Feshbach resonance and yields a high atom-molecule conversion efficiency of more than 30%, a factor of three higher than obtained with conventional magnetic-field ramps. The Cs$_2$ molecules are created in a single $g$-wave rotational quantum state. The observed dependence of the conversion efficiency on the magnetic field and atom density shows scattering processes beyond two-body coupling to occur in the vicinity of the Feshbach resonance.Comment: 7 pages, 4 figures, submitted to Europhysics Letter

The evolution of salamander mimicry: Predators, prey, and perception

Batesian mimicry is an interspecific relationship in which a palatable species, the mimic, avoids attacks from predators by resembling an unpalatable species, the model. Mimicry has long been studied to understand the evolutionary dynamics of adaptation, yet many factors affecting the co-evolution of mimics and models are understudied in natural systems. In the first portion of this dissertation, I describe mimicry between two salamander species in which the erythristic color morph of Plethodon cinereus (the mimic) resembles the juvenile eft stage of Notophthalmus viridescens (the model). I found that the coloration of mimics resembles that of models, particularly from the perspective of avian predators. I also discovered that while mimetic phenotype appears to have converged on model phenotype, selection from predators may drive models to appear distinct from mimics, particularly by appearing more conspicuous against common backgrounds. In the second portion of this dissertation, I evaluate how variation in model toxicity may influence the evolution of mimicry by measuring the concentration of the neurotoxin, tetrodotoxin, in N. viridescens individuals from localities with varying degrees of mimicry. I found that despite significant variation in toxicity among localities, model toxicity did not predict either the occurrence of mimicry or variation in mimetic phenotype. These findings suggest that even though theoretical and experimental studies have predicted a link between model toxicity and mimicry, this relationship may not always be strong enough to influence mimic evolution in natural systems. In the final portion of this dissertation, I identify selection on P. cinereus coloration by mammalian predators. I evaluated mammalian selection on P. cinereus color morphs by measuring mammal attacks on clay replicas of P. cinereus and comparing these attacks against predictions of predator behavior under different hypotheses. Intriguingly, selection by mammalian predators was inconsistent with predictions from the hypothesis of mimicry. Instead, after developing a likelihood-based method for combining non-exclusive hypotheses of predator behavior, I found that mammals appear to use visual cues from salamander prey to preferentially attack familiar and conspicuous individuals. These results are important for the evolution of coloration in P. cinereus because they show that multiple predator species may differentially influence the evolution of coloration and thus complicate predictions of mimicry evolution

Jewish Eating and Identity Through the Ages

A lecture by 2010 Scholar in Residence… Dr. David Kraemer, Professor of Talmud & Rabbinics, Jewish Theological Seminary, NY.https://digitalcommons.fairfield.edu/bennettcenter-posters/1280/thumbnail.jp

An Electromyographic Study of Forward and Backward Walking in Normals and in Subjects following Anterior Cruciate Ligament Repair

Physical therapy strives to incorporate innovative and efficient protocols for rehabilitation of anterior cruciate ligament (ACL) surgeries. Research supports the benefits of closed kinetic chain exercises (distal segment of extremity is fixed) over the traditional open kinetic chain exercises (distal segment not fixed). It is theorized that backward walking on inclined surfaces will recruit the knee musculature to a greater extent than forward walking, but there is little research to support this theory. The purpose of this study was to utilize electromyography during treadmill walking to analyze the muscle activity in the lower extremity of individuals were normal and who have had an ACL repair. Seventeen subjects (11 males, 6 females) at the mean age of25 participated in the study. The results for all subjects were that the muscle activity of the vastus medialis, vastus lateralis, semitendinosus and biceps femoris increased during backward walking in comparison to forward walking. The semitendinosus muscle activity remained relatively equal for forward and backward walking. Increasing the angle of treadmill incline during forward and backward walking generally increased muscle activity. The subjects were classified into two groups, the normal group (N=5) and ACL group (N=12). The results from the two groups varied, however, with small subject number in each group being a large reason for the differences. Future research will need to use a larger number of subjects from both types of repair population