Molecular orientational dynamics of the endohedral fullerene Sc3_{3}N@C80_{80} as probed by 13^{13}C and 45^{45}Sc NMR

We measure 13C and 45Sc NMR lineshapes and spin-lattice relaxation times (T1) to probe the orientational dynamics of the endohedral metallofullerene Sc3N@C80. The measurements show an activated behavior for molecular reorientations over the full temperature range with a similar behavior for the temperature dependence of the 13C and 45Sc data. Combined with spectral data from Magic Angle Spinning (MAS) NMR, the measurements can be interpreted to mean the motion of the encapsulated Sc3N molecule is independent of that of the C80 cage, although this requires the similar temperature dependence of the 13C and 45Sc spin-lattice relaxation times to be coincidental. For the Sc3N to be fixed to the C80 cage, one must overcome the symmetry breaking effect this has on the Sc3N@C80 system since this would result in more than the observed two 13C lines.Comment: 6 pages, 5 figure

Chronic opioid pretreatment potentiates the sensitization of fear learning by trauma.

Despite the large comorbidity between PTSD and opioid use disorders, as well as the common treatment of physical injuries resulting from trauma with opioids, the ability of opioid treatments to subsequently modify PTSD-related behavior has not been well studied. Using the stress-enhanced fear learning (SEFL) model for PTSD, we characterized the impact of chronic opioid regimens on the sensitization of fear learning seen following traumatic stress in mice. We demonstrate for the first time that chronic opioid pretreatment is able to robustly augment associative fear learning. Highlighting aversive learning as the cognitive process mediating this behavioral outcome, these changes were observed after a considerable period of drug cessation, generalized to learning about multiple aversive stimuli, were not due to changes in stimulus sensitivity or basal anxiety, and correlated with a marker of synaptic plasticity within the basolateral amygdala. Additionally, these changes were not observed when opioids were given after the traumatic event. Moreover, we found that neither reducing the frequency of opioid administration nor bidirectional manipulation of acute withdrawal impacted the subsequent enhancement in fear learning seen. Given the fundamental role of associative fear learning in the generation and progression of PTSD, these findings are of direct translational relevance to the comorbidity between opioid dependence and PTSD, and they are also pertinent to the use of opioids for treating pain resulting from traumas involving physical injuries

Distributed fibre optic sensors for measuring strain and temperature of cast-in-situ concrete test piles

In this paper we present the use of distributed fibre optic sensor (DFOS) technology to measure the temperature and strain of reinforced concrete test piles during construction and during static load tests. Eight test piles were recently instrumented with DFOS, on three construction sites in London, by the Cambridge Centre for Smart Infrastructure and Construction (CSIC), in collaboration with Ove Arup & Partners Ltd. The concrete curing temperature profiles of the piles were used to detect the presence of significant defects in the piles. The load test strain profiles along the length of the piles were used to determine the load capacity of the piles and estimate the design parameters of the various soil strata, as well as the internal relative displacement of the piles under various loads. Being distributed in nature, DFOS give a much more detailed picture of the performance of a test pile, as compared to traditional embedded point sensors, such as vibrating wire strain gauges and extensometers. This is demonstrated with a sample of data obtained from one of the instrumented test piles.This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by ICE Publishing

No classical limit of quantum decay for broad states

Though the classical treatment of spontaneous decay leads to an exponential decay law, it is well known that this is an approximation of the quantum mechanical result which is a non-exponential at very small and large times for narrow states. The non exponential nature at large times is however hard to establish from experiments. A method to recover the time evolution of unstable states from a parametrization of the amplitude fitted to data is presented. We apply the method to a realistic example of a very broad state, the sigma meson and reveal that an exponential decay is not a valid approximation at any time for this state. This example derived from experiment, shows the unique nature of broad resonances

Obstacles to Success of Students with Autism Spectrum Disorder in General Education Settings

The purpose of this study was to survey teacher opinions of 14 potential obstacles to teaching in general education classes attended by students with autism spectrum disorder (ASD). The anonymous participant responses were received from 16 elementary school teachers, 60 middle school teachers, and 131 high school teachers. Participants completed a questionnaire in which they rated 14 items. Rating data were uploaded to STATA data analysis software. The Kruskal-Wallis (K-W) statistic was used to analyze and interpret the data. Results identified items that significantly discriminated among teachers of the three grade levels and show a difference in the perceptions of teachers at different grade levels for some obstacles. Teachers at the elementary school level generally perceived greater obstacles than teachers at the middle school level, who perceived greater obstacles than those at the high school level. The results can be considered by educators and service providers when identifying professional development topics and resources to assist educators and service providers in the provision of instruction to maximize the potential for academic and social success for students with ASD in general education settings

On the precision of the theoretical predictions for pi pi scattering

In a recent paper, Pelaez and Yndurain evaluate some of the low energy observables of pi pi scattering and obtain flat disagreement with our earlier results. The authors work with unsubtracted dispersion relations, so that their results are very sensitive to the poorly known high energy behaviour of the scattering amplitude. They claim that the asymptotic representation we used is incorrect and propose an alternative one. We repeat their calculations on the basis of the standard, subtracted fixed-t dispersion relations, using their asymptotics. The outcome fully confirms our earlier findings. Moreover, we show that the Regge parametrization proposed by these authors for the region above 1.4 GeV violates crossing symmetry: Their ansatz is not consistent with the behaviour observed at low energies.Comment: Added more material, mostly in Sects. 7, 8 and 9, in support of the same conclusions. Latex, 28 pages, 3 figure

“What’s the Middle Ground? Am I Ever Going to be the Perfect Teacher?:” Self-Study of a Doctoral Student’s Acculturation Process

In higher education, doctoral training has been identified as a process of stewardship development whereby individuals learn the knowledge and skills required to advance their respective disciplines. Self-study of teacher education practices is one approach that has gained the interest of doctoral students to help them understand their own development whilst also forging recommendations for others in publications. In this self-study, we worked to understand the experiences of Shrehan, a teacher from England beginning doctoral study in the USA. Shrehan had no experience teaching at the college level prior to moving to the USA, and she saw self-study as an opportunity to understand her development and acculturation into an unfamiliar system of higher education. Data were collected through journaling, critical-friend discussions, and artefacts, as well as student data in the form of surveys, exit slips, and focus-group interviews. Qualitative data analysis of Shrehan’s experiences was guided by the four stages of acculturation theory – honeymoon, culture shock, adjustment, and recovery. Shrehan’s journey emphasizes the importance of getting to know undergraduate students and building rapport as key aspects of teaching at the college level. Self-study provided Shrehan with a heightened personal-identity awareness that increased her cultural sensitivity and broadened her worldview. Results are discussed with reference to acculturation theory and future directions for research are provided

Analytic perturbation theory in QCD and Schwinger's connection between the beta-function and the spectral density

We argue that a technique called analytic perturbation theory leads to a well-defined method for analytically continuing the running coupling constant from the spacelike to the timelike region, which allows us to give a self-consistent definition of the running coupling constant for timelike momentum. The corresponding $\beta$-function is proportional to the spectral density, which confirms a hypothesis due to Schwinger.Comment: 11 pages, 2 figure

A systematic review of interventions to boost social relations through improvements in community infrastructure (places and spaces)

The aim of this systematic review is to synthesise the available evidence, and describe the quality of that evidence, in relation to interventions that improve or create the community infrastructure that impacts on social relations and/ or community wellbeing. For this review, we are defining community infrastructure as the physical places and spaces where people can come together, formally or informally, to interact and participate in the social life of the community. We intend to produce a synthesis which is accessible and will inform practice and future research in the area