Two-photon absorption in potassium niobate

We report measurements of thermal self-locking of a Fabry-Perot cavity containing a potassium niobate (KNbO3) crystal. We develop a method to determine linear and nonlinear optical absorption coefficients in intracavity crystals by detailed analysis of the transmission lineshapes. These lineshapes are typical of optical bistability in thermally loaded cavities. For our crystal, we determine the one-photon absorption coefficient at 846 nm to be (0.0034 \pm 0.0022) per m and the two-photon absorption coefficient at 846 nm to be (3.2 \pm 0.5) \times 10^{-11} m/W and the one-photon absorption coefficient at 423 nm to be (13 \pm 2) per m. We also address the issue of blue-light-induced-infrared-absorption (BLIIRA), and determine a coefficient for this excited state absorption process. Our method is particularly well suited to bulk absorption measurements where absorption is small compared to scattering. We also report new measurements of the temperature dependence of the index of refraction at 846 nm, and compare to values in the literature.Comment: 8 pages. To appear in J. Opt. Soc. Am.

Poorer mental health is associated with cognitive deficits in old age

Few studies have examined the association between within-person (WP) reaction time (RT) variability and mental health (depression, anxiety, and social dysphoria) in old age. Therefore, we investigated mental health (using the General Health Questionnaire) and cognitive function (mean RT or WP variability) in 257 healthy, community-dwelling adults aged 50-90 years (M = 63.60). The cognitive domains assessed were psychomotor performance, executive function, visual search, and recognition. Structural equation models revealed that for WP variability, but not mean RT, poorer mental health was associated with visual search and immediate recognition deficits in older persons and that these relationships were partially mediated by executive function. The dissociation between mean RT and WP variability provides evidence that the latter measure may be particularly sensitive to the subtle effects of mental health on cognitive function in old age

Translation and Community in the work of Elizabeth Cary

Explores the role of female community within Elizabeth Cary\u27s translations and her play, The Tragedy of Mariam

Coherent Bayesian inference on compact binary inspirals using a network of interferometric gravitational wave detectors

Presented in this paper is a Markov chain Monte Carlo (MCMC) routine for conducting coherent parameter estimation for interferometric gravitational wave observations of an inspiral of binary compact objects using data from multiple detectors. The MCMC technique uses data from several interferometers and infers all nine of the parameters (ignoring spin) associated with the binary system, including the distance to the source, the masses, and the location on the sky. The Metropolis-algorithm utilises advanced MCMC techniques, such as importance resampling and parallel tempering. The data is compared with time-domain inspiral templates that are 2.5 post-Newtonian (PN) in phase and 2.0 PN in amplitude. Our routine could be implemented as part of an inspiral detection pipeline for a world wide network of detectors. Examples are given for simulated signals and data as seen by the LIGO and Virgo detectors operating at their design sensitivity.Comment: 10 pages, 4 figure

Using the Community Readiness Model to Select Communities for a Community-Wide Obesity Prevention Intervention

To build on a growing interest in community-based obesity prevention programs, methods are needed for matching intervention strategies to local needs and assets. We used the Community Readiness Model (CRM), a structured interview guide and scoring system, to assess community readiness to act on childhood obesity prevention, furthering a replication study of a successful intervention

Increased cyclic GMP and decreased cyclic AMP levels in the hyperplastic, abnormally differentiated epidermis of psoriasis

The genetic skin disease psoriasis has been examined as a model system that may provide an understanding of the control of normal epidermal specialization (differentiation) and the perturbed regulatory processes in proliferative diseases. The excessive glycogen accumulation, increased proliferation and decreased tissue specialization characteristic of psoriasis involve cellular processes that have been shown to be regulated by cyclic AMP in other cells and tissues. It has also been suggested that cyclic GMP is a cellular effector that may be involved in promoting cell proliferation and other events that oppose those believed to be mediated by cyclic AMP. It was postulated, therefore, that the epidermis of the psoriasis lesion might exhibit an imbalance in the cellular concentrations of these two cyclic nucleotides. In this study the levels of cyclic AMP were measured in the involved epidermis (IE) and uninvolved epidermis (UE) from 25 psoriasis patients. The concentrations of cyclic AMP were found as reported previously using a different analytical procedure, to be significantly lower in IE based on protein and DNA. A comparison of the levels of cyclic GMP in IE versus UE of 12 other psoriasis patients showed the levels of this cyclic nucleotide to be significantly increased in IE based on protein, DNA and wet weight. We suggest that this imbalance in the ratio of these two cyclic nucleotides may have pathophysiological relevance to the initiation and/or the maintenance of the psoriasis lesion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33811/1/0000067.pd

Evaluation of Rehabilitation of Memory in Neurological Disabilities (ReMiND): a randomized controlled trial

OBJECTIVE:The evidence for the effectiveness of memory rehabilitation is inconclusive. The aim was to compare the effectiveness of two group memory rehabilitation programmes with a self-help group control. DESIGN:Single-blind randomized controlled trial. PARTICIPANTS:Participants with memory problems following traumatic brain injury, stroke or multiple sclerosis were recruited from community settings. INTERVENTIONS:Participants were randomly allocated, in cohorts of four, to compensation or restitution group treatment programmes or a self-help group control. All programmes were manual-based and comprised two individual and ten weekly group sessions. MAIN MEASURES:Memory functions, mood, and activities of daily living were assessed at baseline and five and seven months after randomization. RESULTS:There were 72 participants (mean age 47.7, SD 10.2 years; 32 men). There was no significant effect of treatment on the Everyday Memory Questionnaire (P = 0.97). At seven months the mean scores were comparable (restitution 36.6, compensation 41.0, self-help 44.1). However, there was a significant difference between groups on the Internal Memory Aids Questionnaire (P = 0.002). The compensation and restitution groups each used significantly more internal memory aids than the self-help group (P 0.05). CONCLUSIONS:There results show few statistically significant effects of either compensation or restitution memory group treatment as compared with a self-help group control. Further randomized trials of memory rehabilitation are needed

Coherent Bayesian analysis of inspiral signals

We present in this paper a Bayesian parameter estimation method for the analysis of interferometric gravitational wave observations of an inspiral of binary compact objects using data recorded simultaneously by a network of several interferometers at different sites. We consider neutron star or black hole inspirals that are modeled to 3.5 post-Newtonian (PN) order in phase and 2.5 PN in amplitude. Inference is facilitated using Markov chain Monte Carlo methods that are adapted in order to efficiently explore the particular parameter space. Examples are shown to illustrate how and what information about the different parameters can be derived from the data. This study uses simulated signals and data with noise characteristics that are assumed to be defined by the LIGO and Virgo detectors operating at their design sensitivities. Nine parameters are estimated, including those associated with the binary system, plus its location on the sky. We explain how this technique will be part of a detection pipeline for binary systems of compact objects with masses up to 20 \sunmass, including cases where the ratio of the individual masses can be extreme.Comment: Accepted for publication in Classical and Quantum Gravity, Special issue for GWDAW-1