1,401 research outputs found

    Preparing students to be doctors: introduction of a sub-internship program.

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    Preparing graduates for the transformation from medical student to doctor provides medical schools with a real challenge. Medical educators advocate a process of graduated delegation of responsibility in the clinical years of medical school. This is best exemplified in the North American system of sub-internship programmes; an educational approach which European medical schools have been slow to adopt. This study reports on the introduction of an intensive two-week surgical sub-internship for final medical year students. \u22Sub-interns\u22 were asked to complete pre and post sub-internship online questionnaires assessing their readiness to perform clinical and practical skills, attitudes towards the program, and how well it prepared students for internship. Forty-nine students completed a questionnaire pre sub-internship and 47 completed the post-questionnaire. Student confidence towards practical and clinical skills and their first day at work increased over the two weeks. Mean Iikert scores for all 6 practical and clinical skills improved post sub-internship. The introduction of a surgical sub-internship is timely and welcomed by medical students. Its development helps bridge the gap in responsibilities between medical student and doctor

    Divergent Mitochondrial Biogenesis Responses in Human Cardiomyopathy

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    Background—Mitochondria are key players in the development and progression of heart failure (HF). Mitochondrial (mt) dysfunction leads to diminished energy production and increased cell death contributing to the progression of left ventricular failure. The fundamental mechanisms that underlie mt dysfunction in HF have not been fully elucidated. Methods and Results—To characterize mt morphology, biogenesis, and genomic integrity in human HF, we investigated left ventricular tissue from nonfailing hearts and end-stage ischemic (ICM) or dilated (DCM) cardiomyopathic hearts. Although mt dysfunction was present in both types of cardiomyopathy, mt were smaller and increased in number in DCM compared with ICM or nonfailing hearts. mt volume density and mtDNA copy number was increased by ≈2-fold (P<0.001) in DCM hearts in comparison with ICM hearts. These changes were accompanied by an increase in the expression of mtDNA-encoded genes in DCM versus no change in ICM. mtDNA repair and antioxidant genes were reduced in failing hearts, suggestive of a defective repair and protection system, which may account for the 4.1-fold increase in mtDNA deletion mutations in DCM (P<0.05 versus nonfailing hearts, P<0.05 versus ICM). Conclusions—In DCM, mt dysfunction is associated with mtDNA damage and deletions, which could be a consequence of mutating stress coupled with a peroxisome proliferator-activated receptor γ coactivator 1α–dependent stimulus for mt biogenesis. However, this maladaptive compensatory response contributes to additional oxidative damage. Thus, our findings support further investigations into novel mechanisms and therapeutic strategies for mt dysfunction in DCM

    Laser ablation loading of a radiofrequency ion trap

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    The production of ions via laser ablation for the loading of radiofrequency (RF) ion traps is investigated using a nitrogen laser with a maximum pulse energy of 0.17 mJ and a peak intensity of about 250 MW/cm^2. A time-of-flight mass spectrometer is used to measure the ion yield and the distribution of the charge states. Singly charged ions of elements that are presently considered for the use in optical clocks or quantum logic applications could be produced from metallic samples at a rate of the order of magnitude 10^5 ions per pulse. A linear Paul trap was loaded with Th+ ions produced by laser ablation. An overall ion production and trapping efficiency of 10^-7 to 10^-6 was attained. For ions injected individually, a dependence of the capture probability on the phase of the RF field has been predicted. In the experiment this was not observed, presumably because of collective effects within the ablation plume.Comment: submitted to Appl. Phys. B., special issue on ion trappin

    Doing gender locally: The importance of ‘place’ in understanding marginalised masculinities and young men’s transitions to ‘safe’ and successful futures

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    Observable anxieties have been developing about the position of boys and young men in contemporary society in recent years. This is expressed as a crisis of masculinity, in which place is often implicitly implicated, but is rarely considered for its role in the shaping of young men’s practices, trajectories and aspirations. Drawing on research conducted with young people who accessed a range of social care support services, this article argues that transition means different things for young men in different locales and that local definitions of masculinity are required to better understand young men’s lives and the opportunities available to them. The authors argue that home life, street life, individual neighbourhoods, regions and nations all shaped the young men’s identities and the practices they (and the staff working with them) drew on in order to create successful futures and ‘safe’ forms of masculinity. It is suggested that this place-based approach has the potential to re-shape the ‘crisis’ discourse surrounding masculinity and the anxieties associated with young men

    Recoil-induced effects in passive and active atomic systems

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    Abstract A theoretical analysis of absorptive optical bistability in a passive atomic medium and bidirectional lasing in an active atomic medium is presented. The atomic medium consists of a collection of cold two-level atoms and the atom-radiation field interaction is described using a one-dimensional semiclassical model. It is shown that when the effects of atomic recoil are included self-consistently, the interaction between the atoms and the radiation can be changed significantly from that when the effects of atomic recoil are neglected.

    Classical and quantum chaos in a circular billiard with a straight cut

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    We study classical and quantum dynamics of a particle in a circular billiard with a straight cut. This system can be integrable, nonintegrable with soft chaos, or nonintegrable with hard chaos, as we vary the size of the cut. We use a quantum web to show differences in the quantum manifestations of classical chaos for these three different regimes.Comment: LaTeX2e, 8 pages including 3 Postscript figures and 4 GIF figures, submitted to Phys. Rev.

    Structure of Colloid-Polymer Suspensions

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    We discuss structural correlations in mixtures of free polymer and colloidal particles based on a microscopic, 2-component liquid state integral equation theory. Whereas in the case of polymers much smaller than the spherical particles the relevant polymer degree of freedom is the center of mass, for polymers larger than the (nano-) particles conformational rearrangements need to be considered. They have the important consequence that the polymer depletion layer exhibits two widely different length scales, one of the order of the particle radius, the other of the order of the polymer radius or the polymer density screening length in dilute or semidilute concentrations, respectively. Their consequences on phase stability and structural correlations are discussed extensively.Comment: 37 pages, 17 figures; topical feature articl
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