Modeling the skin pattern of fishes

Complicated patterns showing various spatial scales have been obtained in the past by coupling Turing systems in such a way that the scales of the independent systems resonate. This produces superimposed patterns with different length scales. Here we propose a model consisting of two identical reaction-diffusion systems coupled together in such a way that one of them produces a simple Turing pattern of spots or stripes, and the other traveling wave fronts that eventually become stationary. The basic idea is to assume that one of the systems becomes fixed after some time and serves as a source of morphogens for the other system. This mechanism produces patterns very similar to the pigmentation patterns observed in different species of stingrays and other fishes. The biological mechanisms that support the realization of this model are discussed

Changes in pain knowledge, attitudes and beliefs of osteopathy students after completing a clinically focused pain education module.

Background: Chronic pain is a substantial burden on the Australian healthcare system with an estimated 19.2% of Australians experiencing chronic pain. Knowledge of the neurophysiology and multidimensional aspects of pain is imperative to ensure health professionals apply a biopsychosocial approach to pain. Questionnaires may be used to assess learner changes in neurophysiology knowledge and beliefs and attitudes towards pain after education interventions.The aim of this study was to evaluate changes in pain neurophysiology knowledge, beliefs and attitudes following a 12 week clinically-focused pain module in year 3 osteopathy students as measured by the Neurophysiology of Pain (NPQ) Questionnaire and Health Care Providers Pain and Impairment Relationship scale (HC-PAIRS). Methods: A pre-post design was utilised. Learners completed a demographic information survey pre-module, and completed the NPQ & HC-PAIRS prior to undertaking, and after completing, a twelve week clinically-focused pain module. Results: Learners (n = 55) completed the NPQ & HC-PAIRS at both time points. The median NPQ score was significantly increased with a large effect size (p < 0.001, z = - 5.71, r = 0.78) following the completion of the module. In contrast, the HC-PAIRS total score was significantly increased after the completion of the module (p < 0.01, z = - 6.95, r = 0.91) suggesting an increase in negative pain attitudes and beliefs. Results indicate that a clinically-focused pain module can increase pain neurophysiology knowledge. However the HC-PAIRS results suggest an increase in negative pain attitudes and beliefs. The HC-PAIRS questionnaire was developed for use with chronic low back pain attitudes & beliefs in practitioners, rather than pre-clinical students. Students were provided with general principles of pain management, rather than condition specific pain management. This study is the first comparing pain neurophysiology knowledge and changes in attitudes and beliefs towards pain pre-post a clinically-focused pain module using the NPQ & HC-PAIRS. Conclusions: There was a significant improvement in NPQ score after the 12 week clinically-focused pain module. The HC-PAIRS result was paradoxical and may reflect issues with the module design or the measurement tool. The module duration is longer than that reported in the literature and demonstrates effectiveness in increasing pain neurophysiology knowledge

Changes in pain knowledge, attitudes and beliefs of osteopathy students after completing a clinically focused pain education module

Abstract Background Chronic pain is a substantial burden on the Australian healthcare system with an estimated 19.2% of Australians experiencing chronic pain. Knowledge of the neurophysiology and multidimensional aspects of pain is imperative to ensure health professionals apply a biopsychosocial approach to pain. Questionnaires may be used to assess learner changes in neurophysiology knowledge and beliefs and attitudes towards pain after education interventions. The aim of this study was to evaluate changes in pain neurophysiology knowledge, beliefs and attitudes following a 12 week clinically-focused pain module in year 3 osteopathy students as measured by the Neurophysiology of Pain (NPQ) Questionnaire and Health Care Providers Pain and Impairment Relationship scale (HC-PAIRS). Methods A pre-post design was utilised. Learners completed a demographic information survey pre-module, and completed the NPQ & HC-PAIRS prior to undertaking, and after completing, a twelve week clinically-focused pain module. Results Learners (n = 55) completed the NPQ & HC-PAIRS at both time points. The median NPQ score was significantly increased with a large effect size (p < 0.001, z = − 5.71, r = 0.78) following the completion of the module. In contrast, the HC-PAIRS total score was significantly increased after the completion of the module (p < 0.01, z = − 6.95, r = 0.91) suggesting an increase in negative pain attitudes and beliefs. Results indicate that a clinically-focused pain module can increase pain neurophysiology knowledge. However the HC-PAIRS results suggest an increase in negative pain attitudes and beliefs. The HC-PAIRS questionnaire was developed for use with chronic low back pain attitudes & beliefs in practitioners, rather than pre-clinical students. Students were provided with general principles of pain management, rather than condition specific pain management. This study is the first comparing pain neurophysiology knowledge and changes in attitudes and beliefs towards pain pre-post a clinically-focused pain module using the NPQ & HC-PAIRS. Conclusions There was a significant improvement in NPQ score after the 12 week clinically-focused pain module. The HC-PAIRS result was paradoxical and may reflect issues with the module design or the measurement tool. The module duration is longer than that reported in the literature and demonstrates effectiveness in increasing pain neurophysiology knowledge

Does the student-led osteopathy clinical learning environment prepare students for practice?

BACKGROUND: For many allied health disciplines, pre-professional clinical education takes place in student-led, on-campus clinic environments. In these environments, pre-professional students undertake patient care under the supervision of qualified health professionals. Literature exploring the benefits of the student-led clinical learning environment is limited and little is known about the role student-led clinics play in preparing pre-professional osteopathy students for professional practice. AIM: To explore the perceptions of osteopathy clinical educators about the role of the student-led clinic at Victoria University (VU) in preparing pre-professional students for professional practice. METHODS: A qualitative collective case study methodology was utilised to explore clinical educator perceptions. Individual interviews were conducted with clinical educators employed in the university osteopathy clinic. Interview questions were framed around the Capabilities for Osteopathic Practice which set the Australian osteopathy practice standards. Data were assessed by two of the authors using thematic analysis. RESULTS: Nine clinical educators out of 31 employed at the university clinic (29%) agreed to participate. Qualitative analysis generated three themes: perceptions of the student-led clinic (SLC) as a learning environment; clinical educator perception of their role in the SLC; and, challenges to and of the SLC environment. CONCLUSIONS: Clinical educators perceived that the student-led osteopathy clinical learning environment develops pre-professional learners to meet some, but not all, of the capabilities for professional practice as an osteopath in Australia. The environment may be improved through faculty development, fostering a proactive learning approach, addressing system-based issues, and providing opportunities to interact with other health professions

A long hard look at MCG-6-30-15 with XMM-Newton

We present first results from a 325 ks observation of the Seyfert 1 galaxy MCG-6-30-15 with XMM-Newton and BeppoSAX. The strong, broad, skewed iron line is clearly detected and is well characterised by a steep emissivity profile within 6r_g (i.e. 6GM/c^2) and a flatter profile beyond. The inner radius of the emission appears to lie at about 2r_g, consistent with results reported from both an earlier XMM-Newton observation of MCG-6-30-15 by Wilms et al. and part of an ASCA observation by Iwasawa et al. when the source was in a lower flux state. The radius and steep emissivity profile do depend however on an assumed incident power-law continuum and a lack of complex absorption above 2.5 keV. The blue wing of the line profile is indented, either by absorption at about 6.7 keV or by a hydrogenic iron emission line. The broad iron line flux does not follow the continuum variations in a simple manner.Comment: 5 pages, accepted by MNRAS Letter

Fluctuation scaling in complex systems: Taylor's law and beyond

Complex systems consist of many interacting elements which participate in some dynamical process. The activity of various elements is often different and the fluctuation in the activity of an element grows monotonically with the average activity. This relationship is often of the form "$fluctuations \approx const.\times average^\alpha$", where the exponent $\alpha$ is predominantly in the range $[1/2, 1]$. This power law has been observed in a very wide range of disciplines, ranging from population dynamics through the Internet to the stock market and it is often treated under the names \emph{Taylor's law} or \emph{fluctuation scaling}. This review attempts to show how general the above scaling relationship is by surveying the literature, as well as by reporting some new empirical data and model calculations. We also show some basic principles that can underlie the generality of the phenomenon. This is followed by a mean-field framework based on sums of random variables. In this context the emergence of fluctuation scaling is equivalent to some corresponding limit theorems. In certain physical systems fluctuation scaling can be related to finite size scaling.Comment: 33 pages, 20 figures, 2 tables, submitted to Advances in Physic

Cortical depth dependent functional responses in humans at 7T: improved specificity with 3D GRASE

Ultra high fields (7T and above) allow functional imaging with high contrast-to-noise ratios and improved spatial resolution. This, along with improved hardware and imaging techniques, allow investigating columnar and laminar functional responses. Using gradient-echo (GE) (T2* weighted) based sequences, layer specific responses have been recorded from human (and animal) primary visual areas. However, their increased sensitivity to large surface veins potentially clouds detecting and interpreting layer specific responses. Conversely, spin-echo (SE) (T2 weighted) sequences are less sensitive to large veins and have been used to map cortical columns in humans. T2 weighted 3D GRASE with inner volume selection provides high isotropic resolution over extended volumes, overcoming some of the many technical limitations of conventional 2D SE-EPI, whereby making layer specific investigations feasible. Further, the demonstration of columnar level specificity with 3D GRASE, despite contributions from both stimulated echoes and conventional T2 contrast, has made it an attractive alternative over 2D SE-EPI. Here, we assess the spatial specificity of cortical depth dependent 3D GRASE functional responses in human V1 and hMT by comparing it to GE responses. In doing so we demonstrate that 3D GRASE is less sensitive to contributions from large veins in superficial layers, while showing increased specificity (functional tuning) throughout the cortex compared to GE

New SPB stars in the field of the young open cluster NGC 2244 discovered by the MOST photometric satellite

During two weeks of nearly continuous optical photometry of the young open cluster NGC 2244 obtained by the MOST satellite, we discovered two new SPB stars, GSC 00154-00785 and GSC 00154-01871. We present frequency analyses of the MOST light curves of these stars, which reveal two oscillation frequencies (0.61 and 0.71 c/d) in GSC 00154-00785 and two (0.40 and 0.51 c/d) in GSC 00154-01871. These frequency ranges are consistent with g-modes of $\ell \leq 2$ excited in models of main-sequence or pre-main-sequence (PMS) stars of masses 4.5 - 5 $M_{\odot}$ and solar composition $(X, Z)= (0.7, 0.02)$. Published proper motion measurements and radial velocities are insufficient to establish unambiguously cluster membership for these two stars. However, the PMS models which fit best their eigenspectra have ages consistent with NGC 2244. If cluster membership can be confirmed, these would be the first known PMS SPB stars, and would open a new window on testing asteroseismically the interior structures of PMS stars.Comment: accepted for publication in MNRA

XMM-Newton and Swift observations of WZ Sge: spectral and timing analysis

WZ Sagittae is the prototype object of a subclass of dwarf novae, with rare and long (super)outbursts, in which a white dwarf primary accretes matter from a low mass companion. High-energy observations offer the possibility of a better understanding of the disk-accretion mechanism in WZ Sge-like binaries. We used archival XMM-Newton and Swift data to characterize the X-ray spectral and temporal properties of WZ Sge in quiescence. We performed a detailed timing analysis of the simultaneous X-ray and UV light curves obtained with the EPIC and OM instruments on board XMM-Newton in 2003. We employed several techniques in this study, including a correlation study between the two curves. We also performed an X-ray spectral analysis using the EPIC data, as well as Swift/XRT data obtained in 2011. We find that the X-ray intensity is clearly modulated at a period of about 28.96 s, confirming previously published preliminary results. We find that the X-ray spectral shape of WZ Sge remains practically unchanged between the XMM-Newton and Swift observations. However, after correcting for inter-stellar absorption, the intrinsic luminosity is estimated to be about 2.65X10^ 30 erg/s/cm^2 and 1.57X10^30 erg/s/cm^2 in 2003 and 2011, respectively. During the Swift/XRT observation, the observed flux is a factor of about 2 lower than that observed by XMM-Newton, but is similar to the quiescent levels observed various times before the 2001 outburst.Comment: Accepted for publication on A&A.10 pages, 9 figure

United classification of cosmic gamma-ray bursts and their counterparts

United classification of gamma-ray bursts and their counterparts is established on the basis of measured characteristics: photon energy E and emission duration T. The founded interrelation between the mentioned characteristics of events consists in that, as the energy increases, the duration decreases (and vice versa). The given interrelation reflects the nature of the phenomenon and forms the E-T diagram, which represents a natural classification of all observed events in the energy range from 10E9 to 10E-6 eV and in the corresponding interval of durations from about 10E-2 up to 10E8 s. The proposed classification results in the consequences, which are principal for the theory and practical study of the phenomenon.Comment: Keywords Gamma rays: burst