27,754 research outputs found
The trajectory to diagnosis with pulmonary arterial hypertension: a qualitative study
Objectives To investigate the patient's experience of the trajectory to receiving a diagnosis of pulmonary arterial hypertension (PAH) and inform the provision of care for this patient group.
Design Qualitative study using in-depth one-to-one interviews and pictorial representations. Data were analysed using thematic analysis.
Setting Participants were interviewed in their own homes across England.
Participants 30 patients with a diagnosis of pulmonary hypertension (18 participants were women, mean age 56 and range 26-80 02years and time since diagnosis ranged from a few months to more than 12 02years) participated.
Results All participants, regardless of the time since diagnosis, vividly described the process from manifestation of symptoms to receiving a confirmed diagnosis. The authors present data using three major themes: (i) making sense of symptoms, (ii) process of elimination and (iii) being diagnosed with PAH. Making sense of symptoms represented an early period of perseverance 14people tried to carry-on as usual despite 18unexplained breathlessness 19. As time progressed, this period was punctuated by critical events that triggered seeking medical advice. Once medical contact had been made, patients described a period of 18elimination 19 and convoluted contact with the medical profession. Dyspnoea misdiagnosis was a key factor that delayed the PAH diagnosis. Diagnosis disclosure by some medical professionals was also viewed as lacking empathy. More positive experiences were relayed when the medical team disclosing the diagnosis acknowledged previous limitations.
Conclusions A lack of awareness of this illness from both the sufferer themselves and the medical profession emerged as a central theme and led to prolonged periods of being misdiagnosed. The application of a diagnostic pathway for unexplained dyspnoea that alerts practitioners to rare conditions could expedite the process of correct diagnosis
Effects of Extreme Obliquity Variations on the Habitability of Exoplanets
We explore the impact of obliquity variations on planetary habitability in
hypothetical systems with high mutual inclination. We show that large
amplitude, high frequency obliquity oscillations on Earth-like exoplanets can
suppress the ice-albedo feedback, increasing the outer edge of the habitable
zone. We restrict our exploration to hypothetical systems consisting of a
solar-mass star, an Earth-mass planet at 1 AU, and 1 or 2 larger planets. We
verify that these systems are stable for years with N-body simulations,
and calculate the obliquity variations induced by the orbital evolution of the
Earth-mass planet and a torque from the host star. We run a simplified energy
balance model on the terrestrial planet to assess surface temperature and ice
coverage on the planet's surface, and we calculate differences in the outer
edge of the habitable zone for planets with rapid obliquity variations. For
each hypothetical system, we calculate the outer edge of habitability for two
conditions: 1) the full evolution of the planetary spin and orbit, and 2) the
eccentricity and obliquity fixed at their average values. We recover previous
results that higher values of fixed obliquity and eccentricity expand the
habitable zone, but also find that obliquity oscillations further expand
habitable orbits in all cases. Terrestrial planets near the outer edge of the
habitable zone may be more likely to support life in systems that induce rapid
obliquity oscillations as opposed to fixed-spin planets. Such planets may be
the easiest to directly characterize with space-borne telescopes.Comment: 46 pages, 12 Figures, 5 Table
Higher Twist, Scaling, and Effective for Lepton Scattering in the Few GeV Region
We use a new scaling variable , and add low modifications to
GRV98 leading order parton distribution functions such that they can be used to
model electron, muon and neutrino inelastic scattering cross sections (and also
photoproduction) at both very low and high energies.Comment: 6 pages, 3 figures. To be published in J. Phys. G (Conf. Proceedings)
based on two talks by Arie Bodek at the NuFact conference, Imperial
College, London, England, July 200
A Rapid Method for Observing the Internal Morphology of Amphibian Embryos
A simple, rapid method for visualizing the internal morphology of amphibian embryos is described. Fixed embryos of Ambystoma mexicanum are surrounded with commercial embedding material and are frozen. Internal structure is revealed by cutting the embryos with a cooled scalpel or razor blade, removing the frozen embedment with an aqueous buffer, and processing the halved embryos for scanning electron microscopy (SEM). This technique allows the internal anatomy of the embryo to be viewed but is much simpler and more rapid than previously described techniques. It should therefore prove useful for understanding and teaching the three-dimensional relationship between tissues in developing embryos. In addition, we believe that this technique could be used, with minor changes, as a rapid method for viewing the internal morphology of a variety of specimens
Novel Details of Calsequestrin Gel Conformation in Situ
Calsequestrin (CASQ) is the major component of the sarcoplasmic reticulum (SR) lumen in skeletal and cardiac muscles. This calcium-binding protein localizes to the junctional SR (jSR) cisternae, where it is responsible for the storage of large amounts of Ca2+, whereas it is usually absent, at least in its polymerized form, in the free SR. The retention of CASQ inside the jSR is due partly to its association with other jSR proteins, such as junctin and triadin, and partly to its ability to polymerize, in a high Ca2+ environment, into an intricate gel that holds the protein in place. In this work, we shed some light on the still poorly described in situ structure of polymerized CASQ using detailed EM images from thin sections, with and without tilting, and from deep-etched rotary-shadowed replicas. The latter directly illustrate the fundamental network nature of polymerized CASQ, revealing repeated nodal points connecting short segments of the linear polymer. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc. Published in the U.S.A
Planning a Family:priorities and concerns in rural Tanzanmia
A fertility survey using qualitative and quantitative techniques described a high fertility setting (TFR 5.8) in southern Tanzania where family planning use was 16%. Current use was influenced by rising parity, educational level, age of last born child, breastfeeding status, a\ud
preference for longer than the mean birth interval (32 months), not being related to the household head, and living in a house with a tin roof. Three principal concerns amongst women were outlined from the findings. First, that there is a large unmet need for family planning services in the area particularly among teenagers for whom it is associated with induced abortion. Second, that family planning is being used predominantly for spacing but fears\ud
associated with it often curtail effective use. Third, that service provision is perceived to be lacking in two main areas â regularity of supply, and addressing rumours and fears associated with family planning. Reproductive health interventions in the area should ultimately be more\ud
widespread and, in particular, abortion is highlighted as an urgent issue for further research.\ud
The potential for a fast and positive impact is high, given the simplicity of the perceived needs of\ud
women from this study. (Afr J Reprod Health 2004; 8[2]:111-123)\u
Flexible copper-indium-diselenide films and devices for space applications
With the ever increasing demands on space power systems, it is imperative that low cost, lightweight, reliable photovoltaics be developed. One avenue of pursuit for future space power applications is the use of low cost, lightweight flexible PV cells and arrays. Most work in this area assumes the use of flexible amorphous silicon (a-Si), despite its inherent instability and low efficiencies. However, polycrystalline thin film PV such as copper-indium-diselenide (CIS) are inherently more stable and exhibit better performance than a-Si. Furthermore, preliminary data indicate that CIS also offers exciting properties with respect to space applications. However, CIS has only heretofore only produced on rigid substrates. The implications of flexible CIS upon present and future space power platforms was explored. Results indicate that space qualified CIS can dramatically reduce the cost of PV, and in most cases, can be substituted for silicon (Si) based on end-of-life (EOL) estimations. Furthermore, where cost is a prime consideration, CIS can become cost effective than gallium arsenide (GaAs) in some applications. Second, investigations into thin film deposition on flexible substrates were made, and data from these tests indicate that fabrication of flexible CIS devices is feasible. Finally, data is also presented on preliminary TCO/CdS/CuInSe2/Mo devices
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