14,260 research outputs found
Pulsation in carbon-atmosphere white dwarfs: A new chapter in white dwarf asteroseismology
We present some of the results of a survey aimed at exploring the
asteroseismological potential of the newly-discovered carbon-atmosphere white
dwarfs. We show that, in certains regions of parameter space, carbon-atmosphere
white dwarfs may drive low-order gravity modes. We demonstrate that our
theoretical results are consistent with the recent exciting discovery of
luminosity variations in SDSS J1426+5752 and some null results obtained by a
team of scientists at McDonald Observatory. We also present follow-up
photometric observations carried out by ourselves at the Mount Bigelow 1.6-m
telescope using the new Mont4K camera. The results of follow-up spectroscopic
observations at the MMT are also briefly reported, including the surprising
discovery that SDSS J1426+5752 is not only a pulsating star but that it is also
a magnetic white dwarf with a surface field near 1.2 MG. The discovery of
-mode pulsations in SDSS J1426+5752 is quite significant in itself as it
opens a fourth asteroseismological "window", after the GW Vir, V777 Her, and ZZ
Ceti families, through which one may study white dwarfs.Comment: 7 pages, 4 figures, to appear in Journal of Physics Conference
Proceedings for the 16th European White Dwarf Worksho
Use of accelerometry to investigate physical activity in dogs receiving chemotherapy
Objectives:
To perform a preliminary study to assess whether single-agent palliative or adjuvant chemotherapy has an impact on objectively measured physical activity in dogs.
Methods:
Fifteen dogs with neoplasia (treatment group) wore ActiGraphâ„¢ accelerometers for 5-day periods before, during and after receiving single-agent adjuvant or palliative chemotherapy. Mean 5-day total physical activity and time spent in three different intensities of activity (sedentary, light-moderate and vigorous) before, during and after receiving chemotherapy were compared to a group of 15 healthy dogs (control group). Results were also compared within the treatment group across time.
Results:
Prior to chemotherapy, treated dogs tended to be less active than control dogs. Treatment group dogs were slightly more active at restaging than they were prior to treatment but had similar activity levels to control dogs. Marked effects of chemotherapy on physical activity were not detected. Physical activity was slightly lower in treated dogs during chemotherapy when compared to control dogs but there was a slight increase in physical activity of treated dogs during chemotherapy when compared with pretreatment recordings. There was little change in the mean 5-day total physical activity between treated dogs during chemotherapy and at restaging but a mild decrease in time spent sedentary and increase in time spent in light-moderate activity at this comparison of time points.
Clinical Significance:
Single-agent adjuvant or palliative chemotherapy had minimal impact on physical activity levels in dogs with neoplasia
SDSS J142625.71+575218.3: the First Pulsating White Dwarf With A Large Detectable Magnetic Field
We report the discovery of a strong magnetic field in the unique pulsating carbon- atmosphere white dwarf SDSS J142625.71 + 575218.3. From spectra gathered at the MMT and Keck telescopes, we infer a surface field of B(s) similar or equal to 1.2 MG, based on obvious Zeeman components seen in several carbon lines. We also detect the presence of a Zeeman- splitted He I lambda 4471 line, which is an indicator of the presence of a nonnegligible amount of helium in the atmosphere of this "hot DQ" star. This is important for understanding its pulsations, as nonadabatic theory reveals that some helium must be present in the envelope mixture for pulsation modes to be excited in the range of effective temperature where the target star is found. Out of nearly 200 pulsating white dwarfs known today, this is the first example of a star with a large detectable magnetic field. We suggest that SDSS J142625.71 + 575218.3 is the white dwarf equivalent of a rapidly oscillating Ap star.NSERCNSF AST 03-07321Reardon FoundationAstronom
Physiological life history and behavioral responses of a breeding bird community to experimentally reduced nest predation risk
The role of reflective practice in professional development
Reflective practice (RP) is a process of critical evaluation and self-assessment whereby one deeply explores an event in order to learn from experiences, and consequently undertakes a change in perception or behaviour. RP can benefit practice through enhancing professionalism and encouraging self-directed learning (SDL). SDL is an important part of the lifelong learning undertaken by registered veterinary nurses (RVNs) who participate in ongoing continuing professional development (CPD). CPD is traditionally delivered using an input-based model, where the time in attendance of activities, such as lectures and seminars, are accrued. Although this model ensures a learning activity has been undertaken, it does not ensure any actual learning has occurred, and whether there has been a resultant increase in professional competency. As such, an outcome-based model of CPD has been proposed by the Royal College of Veterinary Surgeons (RCVS) which includes planning, doing, recording and reflecting. The addition of RP to this new cycle ensures that RVNs explore the completed CPD activity more deeply, and consider what specific learning has occurred. This learning can then be measured as outcomes, which may include, for example, improvements to patient care, client service delivery, local processes, the wider organisation, or the management of staff or students. There have been concerns expressed within the profession about the proposed move to an outcome-based CPD model, including the increased time that measuring and recording outcomes will add to the process. If the implementation of this new model is to prove successful, these concerns will need to be addressed
The role of reflective practice in professional development
Reflective practice (RP) is a process of critical evaluation and self-assessment whereby one deeply explores an event in order to learn from experiences, and consequently undertakes a change in perception or behaviour. RP can benefit practice through enhancing professionalism and encouraging self-directed learning (SDL). SDL is an important part of the lifelong learning undertaken by registered veterinary nurses (RVNs) who participate in ongoing continuing professional development (CPD). CPD is traditionally delivered using an input-based model, where the time in attendance of activities, such as lectures and seminars, are accrued. Although this model ensures a learning activity has been undertaken, it does not ensure any actual learning has occurred, and whether there has been a resultant increase in professional competency. As such, an outcome-based model of CPD has been proposed by the Royal College of Veterinary Surgeons (RCVS) which includes planning, doing, recording and reflecting. The addition of RP to this new cycle ensures that RVNs explore the completed CPD activity more deeply, and consider what specific learning has occurred. This learning can then be measured as outcomes, which may include, for example, improvements to patient care, client service delivery, local processes, the wider organisation, or the management of staff or students. There have been concerns expressed within the profession about the proposed move to an outcome-based CPD model, including the increased time that measuring and recording outcomes will add to the process. If the implementation of this new model is to prove successful, these concerns will need to be addressed
Becoming a reflective practitioner
Reflective practice (RP) can be defined as the process of considering an event or a situation in order to examine the factors that influenced it so that one can determine what could have been done differently, or to identify what learning occurred. RP has many potential benefits to professional practice including developing critically thoughtful approaches to patient care, influencing professional decision-making, developing emotional intelligence, and stimulating personal and professional growth. Specific skills must be developed to successfully undertake RP including self-awareness, description, critical analysis, synthesis and evaluation. These skills can be developed using a model of reflection. Models encourage a structured and guided approach to RP and encourage individuals to achieve a deeper level of understanding of the event. To make effective use of a model of reflection, a written account is preferred. This can easily be achieved through the use of a journal, which is a personal collection of notes, thoughts, observations and experiences. Journals can enhance learning through the action of writing and critically exploring experiences. Group reflection is another method of RP, and allows participants to learn from the perspectives of others, and to receive feedback on their practice. There are barriers to RP including lack of time and power to implement changes, as such there is a need for organisations to recognise the importance of RP and to allocate appropriate resources to help support its action
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