34 research outputs found

    FDG-PET-positive lower-extremity sebaceous-gland carcinoma in a patient with Muir-Torre syndrome

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    Sebaceous-gland carcinoma can occur alone or as one of the defining features of the Muir-Torre syndrome. Cases occurring below the head and neck are extremely rare. Here we describe the case of a 70-year-old male with Muir-Torre syndrome who had a recurrent sebaceous-gland carcinoma in the left lower extremity that demonstrated 18F-FDG avidity. An 18F-FDG-avid lower-extremity sebaceous-gland carcinoma has not been previously reported

    Shifting journalistic roles in democratic transitions: Lessons from Egypt

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    While in the case of the Arab Spring the focus of research and debate was very much on the role of social media in enabling political change both during the uprisings and in their immediate aftermath, the impact of traditional national mass media and journalism on framing this political change has been less addressed. In this article, we investigate the role of Egyptian journalists in shaping Egypt’s complex and fast-moving political transition. Based on a thematic analysis of in-depth interviews and a conceptual framework building on Christians et al.’s normative roles of the media, it can be concluded that the monitorial and facilitative roles, which were prevalent in the early stages of the post-Mubarak era, were quickly overturned in favor of a radical and collaborative role. Egyptian journalists working in private media thus demonized their political adversaries, mainly the Islamists, transforming this political ‘other’ into the ultimate enemy. At the same time, the new military regime was being revered and celebrated. This arguably contributed to further destabilize the fragile transition to democracy. It is furthermore concluded that for democracy to succeed in an Egyptian context, antagonistic political conflicts need to be transformed into agonistic ones both at the level of political culture and media culture

    Diffractive Dissociation In The Interacting Gluon Model

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    We have extended the Interacting Gluon Model (IGM) to calculate diffractive mass spectra generated in hadronic collisions. We show that it is possible to treat both diffractive and non-diffractive events on the same footing, in terms of gluon-gluon collisions. A systematic analysis of available data is performed. The energy dependence of diffractive mass spectra is addressed. They show a moderate narrowing at increasing energies. Predictions for LHC energies are presented.Comment: 12 pages, latex, 14 figures (PostScript Files included); accepted for publication in Phys. Rev. D (Feb.97

    Which medical error to disclose to patients and by whom? Public preference and perceptions of norm and current practice

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    <p>Abstract</p> <p>Background</p> <p>Disclosure of near miss medical error (ME) and who should disclose ME to patients continue to be controversial. Further, available recommendations on disclosure of ME have emerged largely in Western culture; their suitability to Islamic/Arabic culture is not known.</p> <p>Methods</p> <p>We surveyed 902 individuals attending the outpatient's clinics of a tertiary care hospital in Saudi Arabia. Personal preference and perceptions of norm and current practice regarding which ME to be disclosed (5 options: don't disclose; disclose if associated with major, moderate, or minor harm; disclose near miss) and by whom (6 options: any employee, any physician, at-fault-physician, manager of at-fault-physician, medical director, or chief executive director) were explored.</p> <p>Results</p> <p>Mean (SD) age of respondents was 33.9 (10) year, 47% were males, 90% Saudis, 37% patients, 49% employed, and 61% with college or higher education. The percentage (95% confidence interval) of respondents who preferred to be informed of harmful ME, of near miss ME, or by at-fault physician were 60.0% (56.8 to 63.2), 35.5% (32.4 to 38.6), and 59.7% (56.5 to 63.0), respectively. Respectively, 68.2% (65.2 to 71.2) and 17.3% (14.7 to 19.8) believed that as currently practiced, harmful ME and near miss ME are disclosed, and 34.0% (30.7 to 37.4) that ME are disclosed by at-fault-physician. Distributions of perception of norm and preference were similar but significantly different from the distribution of perception of current practice (P < 0.001). In a forward stepwise regression analysis, older age, female gender, and being healthy predicted preference of disclosure of near miss ME, while younger age and male gender predicted preference of no-disclosure of ME. Female gender also predicted preferring disclosure by the at-fault-physician.</p> <p>Conclusions</p> <p>We conclude that: 1) there is a considerable diversity in preferences and perceptions of norm and current practice among respondents regarding which ME to be disclosed and by whom, 2) Distributions of preference and perception of norm were similar but significantly different from the distribution of perception of current practice, 3) most respondents preferred to be informed of ME and by at-fault physician, and 4) one third of respondents preferred to be informed of near-miss ME, with a higher percentage among females, older, and healthy individuals.</p

    An Imperfect Dopaminergic Error Signal Can Drive Temporal-Difference Learning

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    An open problem in the field of computational neuroscience is how to link synaptic plasticity to system-level learning. A promising framework in this context is temporal-difference (TD) learning. Experimental evidence that supports the hypothesis that the mammalian brain performs temporal-difference learning includes the resemblance of the phasic activity of the midbrain dopaminergic neurons to the TD error and the discovery that cortico-striatal synaptic plasticity is modulated by dopamine. However, as the phasic dopaminergic signal does not reproduce all the properties of the theoretical TD error, it is unclear whether it is capable of driving behavior adaptation in complex tasks. Here, we present a spiking temporal-difference learning model based on the actor-critic architecture. The model dynamically generates a dopaminergic signal with realistic firing rates and exploits this signal to modulate the plasticity of synapses as a third factor. The predictions of our proposed plasticity dynamics are in good agreement with experimental results with respect to dopamine, pre- and post-synaptic activity. An analytical mapping from the parameters of our proposed plasticity dynamics to those of the classical discrete-time TD algorithm reveals that the biological constraints of the dopaminergic signal entail a modified TD algorithm with self-adapting learning parameters and an adapting offset. We show that the neuronal network is able to learn a task with sparse positive rewards as fast as the corresponding classical discrete-time TD algorithm. However, the performance of the neuronal network is impaired with respect to the traditional algorithm on a task with both positive and negative rewards and breaks down entirely on a task with purely negative rewards. Our model demonstrates that the asymmetry of a realistic dopaminergic signal enables TD learning when learning is driven by positive rewards but not when driven by negative rewards

    A Comparative Study of Iliotibial Band Tenodesis for Extra-articular Augmentation of ACL Reconstruction Using Staple Versus Interference Screw

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    Background: Rotational laxity has been demonstrated to persist, even in the face of a well-performed Anterior Cruciate Ligament (ACL) reconstruction. The iliotibial band (ITB) has also been shown to have an impact on the control of anterolateral rotational laxity. In particular, recent research would suggest that the capsulo-osseous layer of the ITB, is a major contributor to anterolateral rotational control. Methods: From December 2018 to December 2020, a prospective randomized (simple randomization) analytical clinical study was done to compare the functional outcome of group of patients undergoing ITB for extra articular augmentation of ACL Reconstruction using staple versus group of patients using interference screw. Results: Upon comparing the postoperative, the primary finding is there was significant improvement of pivot shift in both groups with (100 % grade A pivot shift) in group A and (85 % grade A pivot shift) and (15% grade B pivot shift) in group B. So, the primary finding in this study is significant rotational control. The secondary finding is there was statistically significant difference in the postoperative IKDC objective score between the 2 groups (p= 0.004)
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