Hearing in the Juvenile Green Sea Turtle (Chelonia mydas): A Comparison of Underwater and Aerial Hearing Using Auditory Evoked Potentials

Sea turtles spend much of their life in aquatic environments, but critical portions of their life cycle, such as nesting and hatching, occur in terrestrial environments, suggesting that it may be important for them to detect sounds in both air and water. In this study we compared underwater and aerial hearing sensitivities in five juvenile green sea turtles (Chelonia mydas) by measuring auditory evoked potential responses to tone pip stimuli. Green sea turtles detected acoustic stimuli in both media, responding to underwater stimuli between 50 and 1600 Hz and aerial stimuli between 50 and 800 Hz, with maximum sensitivity between 200 and 400 Hz underwater and 300 and 400 Hz in air. When underwater and aerial hearing sensitivities were compared in terms of pressure, green sea turtle aerial sound pressure thresholds were lower than underwater thresholds, however they detected a wider range of frequencies underwater. When thresholds were compared in terms of sound intensity, green sea turtle sound intensity level thresholds were 2–39 dB lower underwater particularly at frequencies below 400 Hz. Acoustic stimuli may provide important environmental cues for sea turtles. Further research is needed to determine how sea turtles behaviorally and physiologically respond to sounds in their environment

Spectroscopy and Dynamics of the Predissociated, Quasi-linear S2 State of Chlorocarbene

In this work, we report on the spectroscopy and dynamics of the quasi-linear S2 state of chlorocarbene, CHCl, and its deuterated isotopologue using optical-optical double resonance (OODR) spectroscopy through selected rovibronic levels of the S1 state. This study, which represents the first observation of the S2 state in CHCl, builds upon our recent examination of the corresponding state in CHF, where pronounced mode specificity was observed in the dynamics, with predissociation rates larger for levels containing bending excitation. In the present work, a total of 14 S2 state vibrational levels with angular momentum ℓ = 1 were observed for CHCl, and 34 levels for CDCl. The range of ℓ in this case was restricted by the pronounced Renner-Teller effect in the low-lying S1 levels, which severely reduces the fluorescence lifetime for levels with Ka \u3e 0. Nonetheless, by exploiting different intermediate S1 levels, we observed progressions involving all three fundamental vibrations. For levels with long predissociation lifetimes, rotational constants were determined by measuring spectra through different intermediate J levels of the S1 state. Plots of the predissociation linewidth (lifetime) vs. energy for various S2 levels show an abrupt onset, which lies near the calculated threshold for elimination to form C(3P) + HCl on the triplet surface. Our experimental results are compared with a series of high level ab initio calculations, which included the use of a dynamically weighted full-valence CASSCF procedure, focusing maximum weight on the state of interest (the singlet and triplet states were computed separately). This was used as the reference for subsequent Davidson-corrected MRCI(+Q) calculations. These calculations reveal the presence of multiple conical intersections in the singlet manifold

‘Silence is the sentence’: adult learners’ experiences of a co-created curriculum constructed through free writing tasks

This paper outlines the pedagogical approaches taken on a University Access course, teaching predominantly mature students on a 12-week ‘inclusion in education’ module. The methods aimed to validate and develop literacy and academic skills for students undertaking undergraduate courses. Practice on the programme of study, replicated over three years, is informed by transformative learning theories. We outline how our developing praxis situates students’ self-concepts in confronting past biographical experiences of education and empowers them to improved literacy and purpose. We further propose that such andragogical approaches to teaching and learning can potentially serve as a model for improved literacy practices in post-compulsory education in England – a curriculum and qualification regime in radical need of overhaul and replacement.&nbsp

Mapping Low-Density Intergalactic Gas: a Third Helium Lyman-alpha Forest

We present a new HST/STIS spectrum of the z=3.18 quasar PKS 1935-692 and summarize the spectral features shortwards of 304A in the rest frame likely to be caused by foreground HeII Lyman-alpha absorption. In accord with previous results on two other quasars at similar redshifts, we demonstrate a correlation with the HI Lyman-alpha forest absorption, and show that much of the helium absorption is caused by a comparable quantity of more diffuse gas with Omega~0.01, that is not detected in HI. The helium ionization zone around the quasar is detected as well as a void seen in both HI and HeII. The properties of the absorption are in broad agreement with those of the other quasars and with models of the protogalactic gas distribution and ionization at this redshift.Comment: 17 pages including 5 figures. As accepted for publication in The Astronomical Journal (minor revisions

What features of a nutrition resource are important to adolescents of a low socioeconomic status?

Acknowledgements: The authors would like to thank Dr Mary Bellizzi, Dr Julia Allan, Julia Clark, Karen Tosh, Dr Heather Morgan and Neil Hendry for their contributions during the development of structured interview questions. We would like to thank Hannah Clews for her continued support during the Streetsport sessions, both prior to and during data collection. Additionally, we would like to thank the staff at Streetsport for their feedback on structured interview questions. Financial support: This work was supported by the University of Aberdeen.Peer reviewedPostprin

Is Gifted Education a Bright Idea? Assessing the Impact of Gifted and Talented Programs on Achievement

In this paper we determine how the receipt of gifted and talented (GT) services affects student outcomes. We identify the causal relationship by exploiting a discontinuity in eligibility requirements and find that for students on the margin there is no discernable impact on achievement even though peers improve substantially. We then use randomized lotteries to examine the impact of attending a GT magnet program relative to GT programs in other schools and find that, despite being exposed to higher quality teachers and peers that are one standard deviation higher achieving, only science achievement improves. We argue that these results are consistent with an invidious comparison model of peer effects offsetting other benefits. Evidence of large reductions in course grades and rank relative to peers in both regression discontinuity and lottery models are consistent with this explanation.