3,172 research outputs found

    Lives and Afterlives of the Lithophylacii Britannici ichnographia (1699), the First Illustrated Field Guide to English Fossils

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    The Lithophylacii Britannicii ichnographia [British figured stones] (1699) by Edward Lhwyd, the second keeper of the Ashmolean Museum, was the first illustrated field guide to English fossils. We analyse this book’s physical creation — the collection of specimens, their engravings and their use and reuse in eighteenth-century editions and collections that were in the transition to binomial taxonomy. With particular concentration on the Lithophylacii’s illustrations of fossils, this paper will first analyse how the specimens were collected. We will then examine the use of these specimens and subsequent editions of Lhwyd’s book, with a focus upon how the relationship between them was drawn on by collectors such as Sir Hans Sloane and Daniel Solander from 1680 to 1760. Finally, we will demonstrate how Ashmolean Keeper William Huddesford repurposed the illustrations for Lhwyd’s book for his eighteenth-century edition of the field guide, incorporating new classificatory schemes. Our analysis will give insight into how a late seventeenth-century book of natural philosophy was used and repurposed by natural historians and collectors before and during the development of Linnaean taxonomy.AHRC Churchill College, Cambridg

    Prolapse or incontinence: what affects sexual function the most?

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    Introduction and hypothesis Pelvic organ prolapse (POP) and stress urinary incontinence (SUI) adversely affect sexual function in women. Comparative studies of the two subgroups are few and results are conflicting. The aim of this study was to compare the effect of POP and SUI on the sexual function of women undergoing surgery for these conditions. Methods The study population comprised women with POP or SUI in a tertiary referral hospital in the UK. Women who underwent SUI surgery had no symptoms of POP and had urodynamically proven stress incontinence. Patients with POP had ≥ stage 2 prolapse, without bothersome urinary symptoms. Pre-operative data on sexual function were collected and compared using an electronic pelvic floor assessment questionnaire (ePAQ). The incidence of sexual dysfunction and comparison of symptoms in both groups were calculated using the Mann–Whitney U test. Results Three hundred and forty-three women undergoing surgery for either SUI or POP were included. Patients were age-matched, with 184 undergoing SUI surgery (age range 33–77 years) and 159 POP surgery (age range 27–78 years; p = 0.869). The overall impact of POP and SUI was not significantly different in the two subgroups (p = 0.703). However, both patients (73 % vs 36 %; p = 0.00) and partners (50 % vs 24 %; p = 0.00) avoid intercourse significantly more frequently in cases with POP compared with SUI. This did not have a significant impact on quality of life. Conclusions The impact of bothersome SUI or POP on sexual function was found to be similar, but patient and partner avoidance in women with POP was greater than those with SUI

    Calibrating and testing tissue equivalent proportional counters with 37Ar

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    A method for testing and calibrating tissue equivalent proportional counters with37Ar is described.37Ar is produced by exposure of argon in its normal isotope composition to thermal neutrons. It is shown that - up to volume ratios of 0.01 of argon to the tissue equivalent gas - there is no appreciable effect of the argon admixture on the function of the proportional counter. Conventional calibration methods with characteristic x-rays or with -particles require modifications of the detectors, and they test only small sub-volumes in the counters. In contrast, argon permits calibrations and tests of the resolution that are representative for the entire counter volume and that do not require changes in detector construction. The method is equally applicable to multi-element proportional counters; it is here exemplified by its application to a long cylindrical counter of simplified design that is part of such a multi-element configuration

    Daphnia revisited: Local stability and bifurcation theory for physiologically structured population models explained by way of an example

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    We consider the interaction between a general size-structured consumer population and an unstructured resource. We show that stability properties and bifurcation phenomena can be understood in terms of solutions of a system of two delay equations (a renewal equation for the consumer population birth rate coupled to a delay differetial equation for the resource concentration). As many results for such systems are available, we can draw rigorous conclusions concerning dynamical behaviour from an analysis of a characteristic equation. We derive the characteristic equation for a fairly general class of population models, including those based on the Kooijman-Metz Daphnia model and a model introduced by Gurney-Nisbet and Jones et al., and next obtain various ecological insights by analytical or numerical studies of special cases

    Manganese pigmented anodized copper as solar selective absorber

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    The study concerns the optical and structural properties of layers obtained by a new efficient surface treatment totally free of chromium species. The process is made up of an anodic oxidation of copper in an alkaline solution followed by an alkaline potassium permanganate dipping post-treatment. Coatings, obtained at the lab and pilot scales, are stable up to 220 °C in air and vacuum, present low emissivity (0.14 at 70 °C) and high solar absorptivity (0.96), i.e. a suitable thermal efficiency (0.84 at 70 °C)

    Influence of topography on tide propagation and amplification in semi-enclosed basins

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    An idealized model for tide propagation and amplification in semi-enclosed rectangular basins is presented, accounting for depth differences by a combination of longitudinal and lateral topographic steps. The basin geometry is formed by several adjacent compartments of identical width, each having either a uniform depth or two depths separated by a transverse topographic step. The problem is forced by an incoming Kelvin wave at the open end, while allowing waves to radiate outward. The solution in each compartment is written as the superposition of (semi)-analytical wave solutions in an infinite channel, individually satisfying the depth-averaged linear shallow water equations on the f plane, including bottom friction. A collocation technique is employed to satisfy continuity of elevation and flux across the longitudinal topographic steps between the compartments. The model results show that the tidal wave in shallow parts displays slower propagation, enhanced dissipation and amplified amplitudes. This reveals a resonance mechanism, occurring when\ud the length of the shallow end is roughly an odd multiple of the quarter Kelvin wavelength. Alternatively, for sufficiently wide basins, also Poincaré waves may become resonant. A transverse step implies different wavelengths of the incoming and reflected Kelvin wave, leading to increased amplitudes in shallow regions and a shift of amphidromic points in the direction of the deeper part. Including the shallow parts near the basin’s closed end (thus capturing the Kelvin resonance mechanism) is essential to reproduce semi-diurnal and diurnal\ud tide observations in the Gulf of California, the Adriatic Sea and the Persian Gulf

    The pitfalls and promise of liquid biopsies for diagnosing and treating solid tumors in children : a review

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    Cell-free DNA profiling using patient blood is emerging as a non-invasive complementary technique for cancer genomic characterization. Since these liquid biopsies will soon be integrated into clinical trial protocols for pediatric cancer treatment, clinicians should be informed about potential applications and advantages but also weaknesses and potential pitfalls. Small retrospective studies comparing genetic alterations detected in liquid biopsies with tumor biopsies for pediatric solid tumor types are encouraging. Molecular detection of tumor markers in cell-free DNA could be used for earlier therapy response monitoring and residual disease detection as well as enabling detection of pathognomonic and therapeutically relevant genomic alterations. Conclusion: Existing analyses of liquid biopsies from children with solid tumors increasingly suggest a potential relevance for molecular diagnostics, prognostic assessment, and therapeutic decision-making. Gaps remain in the types of tumors studied and value of detection methods applied. Here we review the current stand of liquid biopsy studies for pediatric solid tumors with a dedicated focus on cell-free DNA analysis. There is legitimate hope that integrating fully validated liquid biopsy-based innovations into the standard of care will advance patient monitoring and personalized treatment of children battling solid cancers

    Knee complaints vary with age and gender in the adult population. Population-based reference data for the Knee injury and Osteoarthritis Outcome Score (KOOS)

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    BACKGROUND: Self-reported knee complaints may vary with age and gender. Reference data from the adult population would help to better interpret the outcome of interventions due to knee complaints. The objectives of the present study were to describe the variation of self-reported knee pain, function and quality of life with age and gender in the adult population and to establish population-based reference data for the Knee injury and Osteoarthritis Outcome Score (KOOS). METHODS: Population-based cohort retrieved from the national population register. The knee-specific Knee injury and Osteoarthritis Outcome Score (KOOS) was mailed to 840 subjects aged 18–84 yrs. RESULTS: 68% response rate. Women in the age group 55–74 reported more knee-related complaints in all the KOOS subscales than age-matched men. The differences were significant for the subscales Pain (p = 0.027), Symptoms (p = 0.003) and ADL function (p = 0.046). In men, worse ADL and Sport and Recreation function was seen in the oldest age group 75–84 years compared to the younger age groups (p < 0.030). In women, worse Pain (p < 0.007), ADL (p < 0.030), Sport and Recreation (p < 0.001) and QOL (p < 0.002) were seen already in the age group 55–74 compared to the younger age groups. CONCLUSION: We found pain and other symptoms, physical function, and knee-related quality of life to vary with age and gender implying the use of age- and gender matched reference values for improved understanding of the outcome after interventions due to knee injury and knee OA

    Medical students' perceptions of their development of ‘soft skills' Part II : The development of ‘soft skills' through ‘guiding and growing'

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    BackgroundThis paper reports on medical students' views on the ways in which their ‘soft skills' were developed. It is the result of a study on soft skills among two groups of students before and after curriculum reform at the School of Medicine of the University of Pretoria. One of the aims of the reform was to provide more teaching and learning opportunities for the development of soft skills. Soft skills include professional interpersonal and social skills, communication skills, and professional and ethical attitudes.MethodsAs symbolic interactionism was used as the theoretical framework to guide the research, qualitative methods were used to collect the data. A purposive-theoretical sample of 42 final-year medical students from the traditional curriculum and 49 from the reformed curriculum was recruited. Data were collected by means of focus groups, individual in-depth interviews and autobiographical sketches. ResultsThe same categories of comments emerged from the data collected from the study participants from both the traditional and the reformed curriculum. The students ascribed their behaviour related to soft skills to personality and innate features. They had varying opinions on whether soft skills could be taught, but there was as a strong feeling that teaching should focus on principles and guidelines for dealing with difficult situations. They believed that, in the end, they should take responsibility for their own development of soft skills. Most participants felt they could at least grow through exposure to teaching activities and the observation of role models. They also indicated that they had developed their soft skills and constructed their own identity through their interaction with others. Their definition of situations was shaped by their interactions with doctors and educators, fellow students and other health professionals. Interaction with patients was considered the most important. For both groups of students their third year was a watershed, as it is the first year of more intensive patient contact and the beginning of serious learning from interaction with patients. The views on the development of soft skills differed very little between the traditional and reformed curriculum groups, except that students who had followed the reformed curriculum felt more prepared through the increased teaching and training efforts. Further consideration needs to be given to the intention of the changed curriculum compared to the actual effect. The way in which the participants in the study described their development of soft skills could be categorised as a complex interplay between ‘being' and ‘becoming'. Instead of using the word ‘acquisition' of soft skills, ‘development' seemed to be more appropriate. The metaphor of ‘guiding' and ‘growing' also captures the development of these skills better than the terms ‘teaching' and ‘learning'.ConclusionTeaching activities in the clinical years should be adapted with a view to facilitating the students' professional growth. New models for the development of medical educators should be created and institutional barriers should be investigated.For full text, click here: SA Fam Pract 2006;48(8):15-15
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