1,191 research outputs found

    Revised time-of-flight calculations for high-latitude geomagnetic pulsations using a realistic magnetospheric magnetic field model

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    We present a simple time-of-flight analysis of Alfvén pulsations standing on closed terrestrial magnetic field lines. The technique employed in this study in order to calculate the characteristic period of such oscillations builds upon earlier time-of-flight estimates via the implementation of a more recent magnetospheric magnetic field model. In this case the model employed is the Tsyganenko (1996) field model, which includes realistic magnetospheric currents and the consequences of the partial penetration of the interplanetary magnetic field into the dayside magnetopause. By employing a simple description of magnetospheric plasma density, we are therefore able to estimate the period of standing Alfvén waves on geomagnetic field lines over a significantly wider range of latitudes and magnetic local times than in previous studies. Furthermore, we investigate the influence of changing season and upstream interplanetary conditions upon the period of such pulsations. Finally, the eigenfrequencies of magnetic field lines computed by the time-of-flight technique are compared with corresponding numerical solutions to the wave equation and experimentally observed pulsations on geomagnetic field lines

    Empathic understanding : mythical or mystical an exploratory study into the nature of empathy and the relationship between empathy, perceived similarity and compatibility

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    The objectives of this exploratory study into the nature of empathy were two-fold. First, to investigate the association between two measures of counsellor empathy, the Barrett-Lennard Relationship Inventory (BLRI), rated from the perspectives of counsellors and clients and the Truax/Carkhuff Accurate Empathy Scale (TCAE) rated from the perspectives of observers, counselling supervisors and counsellors. Secondly, to investigate whether there was a relationship between empathy and dyadic compatibility (as measured by the FIRO-F scales), or empathy and the occasions, nature and degree of counsellor and client perceived similarity to the other (as described in post-counselling interviews). Sixty counsellor-client dyads (24 dyads across 1 - 3 sessions per dyad) were videotaped during counselling. Counsellors and clients were then interviewed independently, subsequent to each counselling session. The results of the study were described in three sections. Part 1 reported that while the BLRI and the TCAE scale both exhibited a high degree of reliability, they appeared to be measures of different constructs. Results of a factor analysis suggested that not only must the two instruments be treated as independent measures of empathy, but that ratings made from differing counselling perspectives (counsellor, client, external judge) using the same instrument, must also be treated independently. Client ratings of perceived similarity to their counsellors, and client ratings of counsellor (BLRI) empathy were highly correlated although there was no correlation between counsellors' perceived similarity to clients, and counsellor, observer or supervisor ratings of empathy. There was no correlation between FIRO-F dyadic compatibility and either perceived similarity or empathy. Part II involved an intensive case 3tudy comparison of specific dyadic rating patterns across measures of empathy, with patterns obtained from a content analysis of counsellor interview responses to questions on the occasions, nature and degree of similarity perceived between self and other. A complex matrix of findings was obtained which suggested that the link between empathy and counsellor perceived similarity to clients was not uniform and differed across both levels of empathy and perceived similarity. Part III presented an historical review of the nature of empathy, undertaken in order to clarify and interpret earlier reported findings. It was suggested that conceptualizations of empathy have altered markedly over time, largely as a result of researcher's and counselling trainer's need for observable, measurable and trainable processes within counselling. An eight phase model of the process by which empathic understanding may occur was presented, and the manner and extent to which the model could be deemed accountable for the findings of the present study was discussed. It was suggested that the divergent state of research associated with empathy may be largely attributable to the emphasis placed on one or several phases of the process to the exclusion of other phases. Suggestions for further research were offered, and the question was raised as to whether either the BLRI or the TCAE scale were in fact tapping any of the phases of empathy described in the present study

    The representation of scientific research in the national curriculum and secondary school pupils’ perceptions of research, its function, usefulness and value to their lives

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    Young people’s views on what research is, how it is conducted and whether it is important, influences the decisions they make about their further studies and career choices. In this paper we report the analysis of questionnaire data with a particular focus on pupil perceptions of research in the sciences and of the scientific method. The questionnaire was a 25-item Likert Scale (1-5) distributed to seven collaborating schools. We received 2634 returns from pupils across key stages 3, 4 and 5. We also asked teachers to complete the questionnaire in order to explore how they thought their pupils would respond. We received 54 teacher responses. Statistically significant differences in the responses were identified through a chi-square test on SPSS. As what is being taught influences secondary pupil views on research we also consider how the term ‘research’ appears in the national curriculum for England and Wales and the three main English exam boards. The main theoretical construct that informs our analysis of the questionnaire data and the national curriculum is Angela Brew’s 4-tier descriptor of perceptions of research (domino, trading, layer, journey). We use this framework in order to map what, when and how research is presented to school pupils in England and Wales. We also use this framework in order to highlight and discuss certain pupil views that emerged from the questionnaire data and which indicate areas where curriculum and pedagogy intervention may be necessary: pupils seem less confident in their understanding of research as involving the identification of a research question; and, they often see research as a means to confirm one’s own opinion. They do however understand research as involving the generation of new knowledge and the collection of new data, such as interviews and questionnaires as well as laboratory work, field trips and library searches and they appear relatively confident in their statements about their ability to do research, their school experiences of research and the importance of research in their future career choice

    Changes in murine anorectum signaling across the life course

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    Background: Increasing age is associated with an increase in the incidence of chronic constipation and fecal impaction. The contribution of the natural aging process to these conditions is not fully understood. This study examined the effects of increasing age on the function of the murine anorectum.Methods: The effects of increasing age on cholinergic, nitrergic, and purinergic signaling pathways in the murine anorectum were examined using classical organ bath assays to examine tissue function and electrochemical sensing to determine age‐related changes in nitric oxide and acetylcholine release.Key Results: Nitrergic relaxation increased between 3 and 6 months, peaked at 12 months and declined in the 18 and 24 months groups. These changes were in part explained by an age‐related decrease in nitric oxide (NO) release. Cholinergic signaling was maintained with age by an increase in acetylcholine (ACh) release and a compensatory decrease in cholinesterase activity. Age‐related changes in purinergic relaxation were qualitatively similar to nitrergic relaxation although the relaxations were much smaller. Increasing age did not alter the response of the anorectum smooth muscle to exogenously applied ACh, ATP, sodium nitroprusside or KCl. Similarly, there was no change in basal tension developed by the anorectum.Conclusions and Inferences: The decrease in nitrergic signaling with increasing age may contribute to the age‐related fecal impaction and constipation previously described in this model by partially obstructing defecation

    Interstitial cell network volume is reduced in the terminal bowel of ageing mice

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    Ageing is associated with impaired neuromuscular function of the terminal gastrointestinal (GI) tract, which can result in chronic constipation, faecal impaction and incontinence. Interstitial cells of cajal (ICC) play an important role in regulation of intestinal smooth muscle contraction. However, changes in ICC volume with age in the terminal GI tract (the anal canal including the anal sphincter region and rectum)have not been studied. Here, the distribution, morphology and network volume of ICC in the terminal GI tract of 3‐to 4‐month‐old and 26‐to 28‐month‐old C57BL/6mice were investigated. ICC were identified by immunofluorescence labelling of wholemount preparations with an antibody against c‐Kit. ICC network volume was measured by software‐based 3D volume rendering of confocal Z stacks. A significant reduction in ICC network volume per unit volume of muscle was measured in aged animals. No age‐associated change in ICC morphology was detected. The thickness of the circular muscle layer of the anal sphincter region and rectum increased with age, while that in the distal colon decreased. These results suggest that ageing is associated with a reduction in the network volume of ICC in the terminal GI tract, which may influence the normal function of these regions

    A statistical survey of dayside pulsed ionospheric flows as seen by the CUTLASS Finland HF radar

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    International audienceNearly two years of 2-min resolution data and 7- to 21-s resolution data from the CUTLASS Finland HF radar have undergone Fourier analysis in order to study statistically the occurrence rates and repetition frequencies of pulsed ionospheric flows in the noon-sector high-latitude ionosphere. Pulsed ionospheric flow bursts are believed to be the ionospheric footprint of newly reconnected geomagnetic field lines, which occur during episodes of magnetic flux transfer to the terrestrial magnetosphere - flux transfer events or FTEs. The distribution of pulsed ionospheric flows were found to be well grouped in the radar field of view, and to be in the vicinity of the radar signature of the cusp footprint. Two thirds of the pulsed ionospheric flow intervals included in the statistical study occurred when the interplanetary magnetic field had a southward component, supporting the hypothesis that pulsed ionospheric flows are a reconnection-related phenomenon. The occurrence rate of the pulsed ionospheric flow fluctuation period was independent of the radar scan mode. The statistical results obtained from the radar data are compared to occurrence rates and repetition frequencies of FTEs derived from spacecraft data near the magnetopause reconnection region, and to ground-based optical measurements of poleward moving auroral forms. The distributions obtained by the various instruments in different regions of the magnetosphere were remarkably similar. The radar, therefore, appears to give an unbiased sample of magnetopause activity in its routine observations of the cusp footprint

    A statistical survey of dayside pulsed ionospheric flows as seen by the CUTLASS Finland HF radar

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