268 research outputs found

    Outer jet X-ray and radio emission in R Aquarii: 1999.8 to 2004.0

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    Chandra and VLA observations of the symbiotic star R Aqr in 2004 reveal significant changes over the three to four year interval between these observations and previous observations taken with the VLA in 1999 and with Chandra in 2000. This paper reports on the evolution of the outer thermal X-ray lobe-jets and radio jets. The emission from the outer X-ray lobe-jets lies farther away from the central binary than the outer radio jets, and comes from material interpreted as being shock heated to ~10^6 K, a likely result of collision between high speed material ejected from the central binary and regions of enhanced gas density. Between 2000 and 2004, the Northeast (NE) outer X-ray lobe-jet moved out away from the central binary, with an apparent projected motion of ~580 km s^-1. The Southwest (SW) outer X-ray lobe-jet almost disappeared between 2000 and 2004, presumably due to adiabatic expansion and cooling. The NE radio bright spot also moved away from the central binary between 2000 and 2004, but with a smaller apparent velocity than of the NE X-ray bright spot. The SW outer lobe-jet was not detected in the radio in either 1999 or 2004. The density and mass of the X-ray emitting material is estimated. Cooling times, shock speeds, pressure and confinement are discussed.Comment: 23 pages, 8 figure

    Perfluorooctanoic acid exposure assessment on common carp liver through image and ultrastructural investigation

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    Perfluorooctanoic acid (PFOA) poses particular concern as an emerging pollutant in both surface and ground waters. Fish, as a natural inhabitant of these waters and being highly representative of vertebrates, represents an ideal animal model to assess the toxic effects of PFOA. Hereby, liver microscopic texture was comparatively evaluated in individuals of common carp subchronically exposed to PFOA using grayscale differential box counting, a fractal analysis method. Furthermore, liver cytoplasmic glycogen areas and ultrastructure were also evaluated and compared to the image analysis findings. Redundancy Analysis was performed to assess, in summary, how much the variation of fractal dimension and lacunarity was explained by the concentration of PFOA in liver, the mass of liver and the number of proliferating cell nuclear antigen (PCNA)-immunoreactive nuclei. Treatment group ordination was better determined by fractal dimension than lacunarity. Interestingly, a significant complexity increase was associated with the modification of liver microscopic texture due to PFOA exposure. This complexity increase was related to “cloudy swelling”, possibly representing a primarily adaptive strategy against PFOA challenge, rather than a slight, reversible form of degeneration as traditionally proposed. The occurrence of endoplasmic reticulum stress, unfolded protein reaction and hormetic response was proposed and discussed

    The international literature underpinning collaborative practice within practice based experiential learning for the initial education of student pharmacists : a scoping review

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    Abstract Introduction Interprofessional team working within healthcare [1] enables the use of complementary areas of expertise. Collaborative practice (CP) builds on this and enhances recognition and respect for such expertise which facilitates professional synergy. Development of CP needs to be built into initial education programmes and there is global progress. [2] Further, a WHO Framework highlighted the importance of courses developing CP in experiential learning (EL) environments. [1] There is need to develop both CP and EL within pharmacy courses to meet governmental and regulatory aspirations around the clinical and prescribing roles of pharmacists. Aim The aim of this part of a scoping review was to describe the different characteristics of the international literature around the development, implementation and evaluation of CP within practice based EL for initial education of student pharmacists. Methods The six-stage Arksey and O'Malley framework and the PRISMA extension for Scoping Reviews for reporting were followed. Eligibility criteria were defined (Table 1) and electronic searches of relevant databases (Medline, IPA, CINAHL and Google Scholar) conducted from inception to April 2020. MeSH terms and other relevant subject headings and text words were used. First stage involved screening titles / abstracts and second stage involved review of full text articles. A charting tool was developed and used to extract data on: country, study design, methods of evaluation, sector of practice, stage of students, professional groups involved, monitoring and assessment and scope for development. Findings were presented as a descriptive narrative summary. All steps involved independent checks by two of the review team. Results Twenty-eight papers were included with most from the USA (16 papers), with the remainder from Australia (5 papers), UK (5 Papers), Canada and the Netherlands (1 paper each). The majority of papers described quantitative methods using a wide variety of published (some validated) scales (20 scales including RIPLS, SPICE, CPAT) and a number of bespoke survey tools. The main focus was at 'Kirkpatrick model of educational evaluation' level 3 – with 13 papers focussing on changes to professional behaviours. Papers focussed on either hospital (12 papers) or primary care initiatives (12 papers) with the remaining four describing cross-sectoral settings. Only 6 papers stated that they focussed on specific healthcare specialities and the remainder were in general medical facilities. The nature of initiatives and activities varied with a predominance of focus to include later years of study. Only 3 papers included only pharmacy and medicine students.. Detailed information was lacking on methods of student assessment: some reported this involved reflection, with limited reporting of tools to assess competencies. A wide array of further research proposals was articulated. Conclusion This scoping review highlights the range of work already carried out. The diversity highlights the need for consideration of commonality in the nature of activity and tools to evaluate outcomes to ensure transferability to practice. There are many challenges influencing further development and implementation of CP. Facilitating matters by using the evidence base to add to existing placements without restructuring curricula across courses / institutions has been proposed by some authors

    Interprofessional education during experiential learning placements for student pharmacists in Scotland. Exploring current support provision and stakeholder views.

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    Introduction Increasing global awareness that interprofessional team working is essential within modern healthcare systems has led to regulatory bodies mandating the inclusion of interprofessional education (IPE) within undergraduate curricula. The General Pharmaceutical Council specifies in the 2021 initial education and training standards the requirement for an interprofessional learning plan in which “IPE must mirror practice”.1 Pharmacy educators are intensifying their efforts to ensure student pharmacists are presented with opportunities to develop collaborative competencies. Curricular development and implementation initiatives must explore structures and processes to ensure that experiential learning (EL) environments are conducive to supporting student pharmacists’ interprofessional learning. Aim To explore structures and processes needed to support effective planned and unplanned IPE during EL placements for student pharmacists. Methods A mixed methods approach underpinned by the Biggs 3P theoretical framework was adopted.2 This included (1) A document analysis reviewing resources including student pharmacist/EL facilitator university handbooks and NHS Education for Scotland Preparation for Facilitating Experiential Learning (PFEL) training - a mandatory requirement for all EL facilitators hosting student pharmacists on placement in Scotland. (2) A pre-piloted online survey distributed to EL facilitators. Survey development, guided by the Interprofessional Facilitation Scale, aimed to encourage EL facilitators to self-evaluate their own IPE facilitation skills.3 The final survey tool included ten items with responses rated on a 4-point Likert scale (Poor, Fair, Good and Excellent) and a demographic section (3) Online semi-structured focus groups/dyadic interviews conducted with six EL facilitators, four practice educators and two academic staff were recorded and transcribed. Descriptive statistics were employed for quantitative data generated from the survey tool; for qualitative data content analysis was applied to develop emerging themes. Ethical approval was granted (S292) from the School of Pharmacy and Life Sciences Ethics Review Committee at Robert Gordon University. Results (1) The document analysis concluded that although the resources reviewed could not be specifically classed as training to support IPE, data collected provided context to EL placements and the training and pre-activities that student pharmacists and EL facilitators complete. Three main themes emerged: “Lack of specific IPE training focus”, “Varied terminology”, “Lack of IPE pre-learning activities”. (2) The survey was completed by ninety EL facilitators working in various practice settings: hospital 41.1% (n=37); primary care 25.6% (n=23); community 21.1% (n=19); academia 2.2% (n=2); other 8.9% (n=8). Survey responses indicated that 51.1% (n=46) and 42.2% (n=38) of respondents rated their ability to role model positive interactions with other healthcare professionals as good and excellent. However, responses to items relating more specifically to IPE facilitation skills indicated a lower confidence level. (3) Initial themes emerging from focus groups/dyadic interviews include “Profession-related perceptions of IPE”, “Factors influencing IPE delivery and student learning”, “Factors influencing future developments”. Discussion/Conclusion This exploratory study has provided valuable insight into multifactorial aspects affecting IPE during EL placements; this will be used to guide future development of IPE initiatives. One limitation is that student pharmacists were not included in this study; the next phase of this research programme will explore student pharmacists’ perceptions of IPE in EL

    Discovery of Rapid Hard X-ray Variability and New Jet Activity in the Symbiotic Binary R Aqr

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    Two Chandra observations of the R Aqr symbiotic binary system taken 3.3 years apart show dramatic changes in the X-ray morphology and spectral characteristics in the inner 500 AU of this system. The morphology of the soft X-ray emission has evolved from a nearly circular region centered on the binary system to an hourglass shape that indicates the formation of a new southwest jet. Synchrotron radiation from the new jet in contemporaneous VLA radio spectra implies the physical conditions in the early stages of jet development are different from those in the more extended outer thermal jets known to exist for decades in this system. The central binary source has two X-ray spectral components in each of the two epochs, a soft component and a highly absorbed hard component characterized by T ~ 10^8 K if fit with a thermal plasma model. The spectrum hardened considerably between 2000.7 and 2004.0, primarily due to increased flux above 5 keV, suggesting a change in the accretion activity of the white dwarf on a timescale of a few years or less. Point-source Fe K emission is detected at the position of the central binary system in both observations. While the earlier observation shows evidence of only a single emission peak near Fe K alpha at 6.4 keV, the later observation shows a more complex emission structure between 6 and 7 keV. Finally, we have discovered a modulation in the hard X-ray flux with a period of 1734 s at a 95% confidence level in the 2004 observation only. The modulation potentially arises from standing shocks in an accretion column and we have explored the possibility that the white dwarf in R Aqr is analogous to the magnetic white dwarfs in Intermediate Polar.Comment: 31 pages, 14 figures, 1 table To be published in ApJ, expected April 10 issue. AAS LaTex styl

    Predicting Chandra CCD Degradation with the Chandra Radiation Model

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    Not long after launch of the Chandra X-Ray Observatory, it was discovered that the Advanced CCD Imaging Spectrometer (ACIS) detector was rapidly degrading due to radiation. Analysis by Chandra personnel showed that this degradation was due to 10w energy protons (100 - 200 keV) that scattered down the optical path onto the focal plane. In response to this unexpected problem, the Chandra Team developed a radiation-protection program that has been used to manage the radiation damage to the CCDs. This program consists of multiple approaches - scheduled sating of the ACIS detector from the radiation environment during passage through radiation belts, real-time monitoring of space weather conditions, on-board monitoring of radiation environment levels, and the creation of a radiation environment model for use in computing proton flux and fluence at energies that damage the ACIS detector. This radiation mitigation program has been very successful. The initial precipitous increase in the CCDs' charge transfer inefficiency (CTI) resulting from proton damage has been slowed dramatically, with the front-illuminated CCDS having an increase in CTI of only 2.3% per year, allowing the ASIS detector's expected lifetime to exceed requirements. This paper concentrates on one aspect of the Chandra radiation mitigation program, the creation of the Chandra Radiation Model (CRM). Because of Chandra's highly elliptical orbit, the spacecraft spends most of its time outside of the trapped radiation belts that present the severest risks to the ACIS detector. However, there is still a proton flux environment that must be accounted for in all parts of Chandra's orbit. At the time of Chandra's launch there was no engineering model of the radiation environment that could be used in the outer regions of the spacecraft's orbit, so the CRM was developed to provide the flux environment of 100 - 200 keV protons in the outer magnetosphere, magnetosheath, and solar wind regions of geospace. This presentation describes CRM, its role in Chandra operations, and its prediction of the ACIS CTI increase

    Managing Radiation Degradation of CCDs on the Chandra X-Ray Observatory--III

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    The CCDs on the Chandra X-ray Observatory are vulnerable to radiation damage from low-energy protons scattered off the telescope's mirrors onto the focal plane. Following unexpected damage incurred early in the mission, the Chandra team developed, implemented, and maintains a radiation-protection program. This program--involving scheduled radiation safing during radiation-belt passes, intervention based upon real-time space-weather conditions and radiation-environment modeling, and on-board radiation monitoring with autonomous radiation safing--has successfully managed the radiation damage to the CCDs. Since implementing the program, the charge-transfer inefficiency (CTI) has increased at an average annual rate of only 3.2x 10(exp -6) (2.3 percent) for the front-illuminated CCDs and 1.0x10(exp -6) (6.7 percent) for the back-illuminated CCDs. This paper describes the current status of the Chandra radiation-management program, emphasizing enhancements implemented since the previous papers

    Achieving Self-Directed Integrated Cancer Aftercare (ASICA) in melanoma: protocol for a randomised patient-focused pilot trial of delivering the ASICA intervention as a means to earlier detection of recurrent and second primary melanoma.

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    BACKGROUND: Melanoma is common; 15,906 people in the UK were diagnosed with melanoma in 2015 and incidence has increased fivefold in 30 years. Melanoma affects old and young people, with poor prognosis once metastatic. UK guidelines recommend people treated for cutaneous melanoma receive extended outpatient, hospital follow up to detect recurrence or new primaries. Such follow up of the growing population of melanoma survivors is burdensome for both individuals and health services. Follow up is important since approximately 20% of patients with early-stage melanoma experience a recurrence and 4-8% develop a new primary; the risk of either is highest in the first 5 years. Achieving Self-directed Integrated Cancer Aftercare (ASICA) is a digital intervention to increase total-skin-self-examination (TSSE) by people treated for melanoma, with usual follow up. METHODS: We aim to recruit 240 adults with a previous first-stage 0-2C primary cutaneous melanoma, from secondary care in North-East Scotland and the East of England. Participants will be randomised to receive the ASICA intervention (a tablet-based digital intervention to prompt and support TSSE) or control group (treatment as usual). Patient-reported and clinical data will be collected at baseline, including the modified Melanoma Worry Scale (MWS), the Hospital Anxiety and Depression Scale (HADs), the EuroQoL 5-dimension 5-level questionnaire (EQ-5D-5 L), and questions about TSSE practice, intentions, self-efficacy and planning. Participants will be followed up by postal questionnaire at 3, 6 and 12 months following randomization, along with a 12-month review of clinical data. The primary timepoint for outcome analyses will be12 months after randomisation. DISCUSSION: If the ASICA intervention improves the practice of TSSE in those affected by melanoma, this may lead to improved psychological well-being and earlier detection of recurrent and new primary melanoma. This could impact both patients and National Health Service (NHS) resources. This study will determine if a full-scale randomised controlled trial can be undertaken in the UK NHS to provide the high-quality evidence needed to determine the effectiveness of the intervention. ASICA is a pilot study evaluating the effectiveness of the practice of digitally supported TSSE in those affected by melanoma. TRIAL REGISTRATION: Clinical Trials.gov, NCT03328247 . Registered on 1 November 2017
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