New Limits on Local Lorentz Invariance in Mercury and Cesium

We report new bounds on Local Lorentz Invariance (LLI) violation in Cs and Hg. The limits are obtained through the observation of the the spin- precession frequencies of 199Hg and 133Cs atoms in their ground states as a function of the orientation of an applied magnetic field with respect to the fixed stars. We measure the amplitudes of the dipole couplings to a preferred direction in the equatorial plane to be 19(11) nHz for Hg and 9(5) microHz for Cs. The upper bounds established here improve upon previous bounds by about a factor of four. The improvement is primarily due to mounting the apparatus on a rotating table. New bounds are established on several terms in the standard model extension including the first bounds on the spin-couplings of the neutron and proton to the z direction, <7e-30 GeV and <7e-29 GeV, respectively.Comment: 17 pages, 6 figure

Entrainment and chaos in a pulse-driven Hodgkin-Huxley oscillator

The Hodgkin-Huxley model describes action potential generation in certain types of neurons and is a standard model for conductance-based, excitable cells. Following the early work of Winfree and Best, this paper explores the response of a spontaneously spiking Hodgkin-Huxley neuron model to a periodic pulsatile drive. The response as a function of drive period and amplitude is systematically characterized. A wide range of qualitatively distinct responses are found, including entrainment to the input pulse train and persistent chaos. These observations are consistent with a theory of kicked oscillators developed by Qiudong Wang and Lai-Sang Young. In addition to general features predicted by Wang-Young theory, it is found that most combinations of drive period and amplitude lead to entrainment instead of chaos. This preference for entrainment over chaos is explained by the structure of the Hodgkin-Huxley phase resetting curve.Comment: Minor revisions; modified Fig. 3; added reference

A developmental investigation of the relationship between appraisals and peer self-esteem in children experiencing peer-aggression

Transactional models of stress and coping emphasize the role played by cognitive appraisals in determining psychological adjustment (Lazarus, 1999). This proposition has been supported by research examining young people's adjustment in relation to family conflict and break-up (Grych et al., 1992). Furthermore, this literature suggests that there is a change in the relationship between appraisals and adjustment at around 10 years of age: specificity of appraisal type (e.g. threat, blame) becomes relevant to outcome after 10 years, whereas before 10 there are either no effects of appraisal on adjustment or a diffuse effect of 'negative' appraisals more generally (Jouriles et al., 2000). However, it is currently unclear whether this developmental progression can be generalized from familial- to social-stressors experienced by children and young people. The current study therefore evaluates the model within the context of a commonly experienced social childhood stressor: peer-aggression

Facing up to the challenge of behavioural observation in infant hearing assessment

The ability to assess detection and discrimination of speech by infants has proved elusive. Dr Iain Jackson and colleagues discuss how new technologies and fresh approaches might offer valuable insight into young infants’ behavioural responses to sound

A novel ingress node design for video streaming over optical burst switching networks

This paper introduces a novel ingress node design which takes advantage of video data partitioning in order to deliver enhanced video streaming quality when using H.264/AVC codec over optical burst switching networks. Ns2 simulations show that the proposed scheme delivers improved video traffic quality without affecting other traffic, such as best effort traffic. Although the extra network load is comparatively small, the average gain in video PSNR was 5 dB over existing burst cloning schemes, with a maximum end-to-end delay of 17 ms, and jitter of less than 0.35 ms

Building service capacity within a Regional District Mental Health Service: recommendations from an indigenous mental health symposium

[Abstract]: In response to recent developments within the mental health services of south-east Queensland, the Toowoomba District Mental Health Service (TDMHS) has developed a Model of Service Delivery, which outlines the range of services provided for consumers across their lifespan. Indigenous consumers of the TDMHS come from a wide area of communities in the surrounding shires (Rural, remote and metropolitan areas (RRMA) 4-7). It was recognised by the service that Indigenous mental health consumers have unique needs and, because of these needs, this area of service delivery required greater attention and further development. In December 2004, a symposium was organised by the service to bring together a range of speakers and delegates working in the area of Indigenous mental health to discuss issues and work towards developing strategies to enable the service to better meet the needs of Indigenous consumers in this region of south-east Queensland. Issues: The symposium program consisted of keynote speakers and invited papers and culminated with an afternoon workshop that collated the symposium’s main issues and themes around building service capacity for Indigenous mental health consumers. The objective of the workshop was ‘Identifying ways to meet Indigenous mental health needs’. This workshop gave the delegates a chance to reflect, discuss and brainstorm the major issues of concern relating to this question. A group facilitator guided the discussion and organised the delegates into groups to evaluate, debate and propose recommendations for each of the major issues that emerged. Lessons learned: The feedback and discussion arising from the workshop is presented. Sixteen major themes emerged from the workshop. Seven of these were voted by the participants as being dominant and in greatest need of discussion: (1) communication; (2) cultural respect; (3) culturally appropriate clinical tools; (4) supportive management; (5) patient compliance; (6) career structure; and (7) empowerment. These seven themes are discussed and recommendations arising from the workshop are noted

Impaired Hyperemic Response to Exercise Post Stroke

Individuals with chronic stroke have reduced perfusion of the paretic lower limb at rest; however, the hyperemic response to graded muscle contractions in this patient population has not been examined. This study quantified blood flow to the paretic and non-paretic lower limbs of subjects with chronic stroke after submaximal contractions of the knee extensor muscles and correlated those measures with limb function and activity. Ten subjects with chronic stroke and ten controls had blood flow through the superficial femoral artery quantified with ultrasonography before and immediately after 10 second contractions of the knee extensor muscles at 20, 40, 60, and 80% of the maximal voluntary contraction (MVC) of the test limb. Blood flow to the paretic and non-paretic limb of stroke subjects was significantly reduced at all load levels compared to control subjects even after normalization to lean muscle mass. Of variables measured, increased blood flow after an 80% MVC was the single best predictor of paretic limb strength, the symmetry of strength between the paretic and non-paretic limbs, coordination of the paretic limb, and physical activity. The impaired hemodynamic response to high intensity contractions was a better predictor of lower limb function than resting perfusion measures. Stroke-dependent weakness and atrophy of the paretic limb do not explain the reduced hyperemic response to muscle contraction alone as the response is similarly reduced in the non-paretic limb when compared to controls. These data may suggest a role for perfusion therapies to optimize rehabilitation post stroke

Stroke-related Changes in Neuromuscular Fatigue of the Hip Flexors and Functional Implications

Objective: The aim of this study was to compare stroke-related changes in hip flexor neuromuscular fatigue of the paretic leg during a sustained isometric submaximal contraction with those of the nonparetic leg and controls and to correlate fatigue with clinical measures of function. Design: Hip torques were measured during a fatiguing hip flexion contraction at 20% of the hip flexion maximal voluntary contraction in the paretic and nonparetic legs of 13 people with chronic stroke and 10 age-matched controls. In addition, the participants with stroke performed a fatiguing contraction of the paretic leg at the absolute torque equivalent to 20% maximal voluntary contraction of the nonparetic leg and were tested for self-selected walking speed (10-m Walk Test) and balance (Berg). Results: When matching the nonparetic target torque, the paretic hip flexors had a shorter time to task failure compared with the nonparetic leg and controls (P \u3c 0.05). The time to failure of the paretic leg was inversely correlated with the reduction of hip flexion maximal voluntary contraction torque. Self-selected walking speed was correlated with declines in torque and steadiness. Berg-Balance scores were inversely correlated with the force fluctuation amplitude. Conclusions: Fatigue and precision of contraction are correlated with walking function and balance after stroke

All things being equal: Does it matter for equity how you organise and pay for health care? A review of the International Evidence

Over the last 25 years, the health care systems of most high-income countries have experienced extensive—usually market-based—organizational and financial reforms. The impact of these system changes on health equity has been hotly debated. Examining evidence from systematic reviews of the effects of health care system organizational and financial reforms will add empirical information to this debate, identify any evidence gaps, and help policy development. Systematic review methodology was used to locate and evaluate published systematic reviews of quantitative intervention studies (experimental and observational) of the effects on equity in health care access and/or health status of health care system organizational and financial reforms (system financing, funding allocations, direct purchasing arrangements, organization of service provision, and health and social care system integration) in high-income countries. Nine systematic reviews were identified. Private insurance and out-of-pocket payments as well as the marketization and privatization of services have either negative or inconclusive equity effects. The evidence base on the health equity effects of managed care programs or integrated partnerships between health and social services is inconclusive. There were no relevant studies located that related to resource allocation reforms. The systematic review-level evidence base suggests that financial and organizational health care system reforms have had either inconclusive or negative impacts on health equity both in terms of access relative to need and in terms of health outcomes