77 research outputs found

    Myxoid fibroblastic tumor of the maxillary sinus in a 21-month-old child: An unusual diagnosis.

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    Myxoid tumors of the soft tissue are a heterogeneous group of lesions with significant differences in behavior, from being totally harmless to malignant tumors with metastasizing potential. We describe the unusual case of a 21-month-old boy who developed a paranasal low-grade myxoid neoplasm with recurrent potential. The histological findings showed a proliferation of spindle cells within a vascular and myxoid background. The immunohistochemistry had the features of myofibroblasts and fibroblasts with strong Vimentin and light Smooth Muscle Actin reactivity. Close collaboration between clinician and pathologist is necessary to deal with these unusual lesions to predict their local aggressiveness and long-term behavior. Most of these cellular myxomas have been described in adults, involving primarily the limbs, but this case shows that any localization is possible

    Distinguishing among Scalar Field Models of Dark Energy

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    We show that various scalar field models of dark energy predict degenerate luminosity distance history of the Universe and thus cannot be distinguished by supernovae measurements alone. In particular, models with a vanishing cosmological constant (the value of the potential at its minimum) are degenerate with models with a positive or negative cosmological constant whose magnitude can be as large as the critical density. Adding information from CMB anisotropy measurements does reduce the degeneracy somewhat but not significantly. Our results indicate that a theoretical prior on the preferred form of the potential and the field's initial conditions may allow to quantitatively estimate model parameters from data. Without such a theoretical prior only limited qualitative information on the form and parameters of the potential can be extracted even from very accurate data.Comment: 15 pages, 5 figure

    First results from the Very Small Array -- IV. Cosmological parameter estimation

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    We investigate the constraints on basic cosmological parameters set by the first compact-configuration observations of the Very Small Array (VSA), and other cosmological data sets, in the standard inflationary LambdaCDM model. Using a weak prior 40 < H_0 < 90 km/s/Mpc and 0 < tau < 0.5 we find that the VSA and COBE_DMR data alone produce the constraints Omega_tot = 1.03^{+0.12}_{-0.12}, Omega_bh^2 = 0.029^{+0.009}_{-0.009}, Omega_cdm h^2 = 0.13^{+0.08}_{-0.05} and n_s = 1.04^{+0.11}_{-0.08} at the 68 per cent confidence level. Adding in the type Ia supernovae constraints, we additionally find Omega_m = 0.32^{+0.09}_{-0.06} and Omega_Lambda = 0.71^{+0.07}_{-0.07}. These constraints are consistent with those found by the BOOMERanG, DASI and MAXIMA experiments. We also find that, by combining all the recent CMB experiments and assuming the HST key project limits for H_0 (for which the X-ray plus Sunyaev--Zel'dovich route gives a similar result), we obtain the tight constraints Omega_m=0.28^{+0.14}_{-0.07} and Omega_Lambda= 0.72^{+0.07}_{-0.13}, which are consistent with, but independent of, those obtained using the supernovae data.Comment: 10 pages, 6 figures, MNRAS in pres

    Interacting Ghost Dark Energy in Non-Flat Universe

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    A new dark energy model called "ghost dark energy" was recently suggested to explain the observed accelerating expansion of the universe. This model originates from the Veneziano ghost of QCD. The dark energy density is proportional to Hubble parameter, ρD=αH\rho_D=\alpha H, where α\alpha is a constant of order ΛQCD3\Lambda_{\rm QCD}^3 and ΛQCD100MeV\Lambda_{\rm QCD}\sim 100 MeV is QCD mass scale. In this paper, we extend the ghost dark energy model to the universe with spatial curvature in the presence of interaction between dark matter and dark energy. We study cosmological implications of this model in detail. In the absence of interaction the equation of state parameter of ghost dark energy is always wD>1w_D > -1 and mimics a cosmological constant in the late time, while it is possible to have wD<1w_D < -1 provided the interaction is taken into account. When k=0k = 0, all previous results of ghost dark energy in flat universe are recovered. To check the observational consistency, we use Supernova type Ia (SNIa) Gold sample, shift parameter of Cosmic Microwave Background radiation (CMB) and the Baryonic Acoustic Oscillation peak from Sloan Digital Sky Survey (SDSS). The best fit values of free parameter at 1σ1\sigma confidence interval are: Ωm0=0.350.03+0.02\Omega_m^0= 0.35^{+0.02}_{-0.03}, ΩD0=0.750.04+0.01\Omega_D^0=0.75_{-0.04}^{+0.01} and b2=0.080.03+0.03b^2=0.08^{+0.03}_{-0.03}. Consequently the total energy density of universe at present time in this model at 68% level equates to Ωtot0=1.100.05+0.02\Omega_{\rm tot}^0=1.10^{+0.02}_{-0.05}.Comment: 19 pages, 9 figures. V2: Added comments, observational consequences, references, figures and major corrections. Accepted for publication in General Relativity and Gravitatio

    Vector field as a quintessence partner

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    We derive generic equations for a vector field driving the evolution of flat homogeneous isotropic universe and give a comparison with a scalar filed dynamics in the cosmology. Two exact solutions are shown as examples, which can serve to describe an inflation and a slow falling down of dynamical ``cosmological constant'' like it is given by the scalar quintessence. An attractive feature of vector field description is a generation of ``induced mass'' proportional to a Hubble constant, which results in a dynamical suppression of actual cosmological constant during the evolution.Comment: 14 pages, LaTeX file, iopart class, discussion extended, reference adde

    Change in basic motor abilities, quality of movement and everyday activities following intensive, goal-directed, activity-focused physiotherapy in a group setting for children with cerebral palsy

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    Background: The effects of intensive training for children with cerebral palsy (CP) remain uncertain. The aim of the study was to investigate the impact on motor function, quality of movements and everyday activities of three hours of goal-directed activity-focused physiotherapy in a group setting, five days a week for a period of three weeks. Methods: A repeated measures design was applied with three baseline and two follow up assessments; immediately and three weeks after intervention. Twenty-two children with hemiplegia (n = 7), diplegia (n = 11), quadriplegia (n = 2) and ataxia (n = 2) participated, age ranging 3-9 y. All levels of Gross Motor Function Classification System (GMFCS) and Manual Ability Classification System (MACS) were represented. Parents and professionals participated in goal setting and training. ANOVA was used to analyse change over repeated measures. Results: A main effect of time was shown in the primary outcome measure; Gross Motor Function Measure-66 (GMFM- 66), mean change being 4.5 (p < 0.01) from last baseline to last follow up assessment. An interaction between time and GMFCS-levels was found, implying that children classified to GMFCS-levels I-II improved more than children classified to levels III-V. There were no main or interaction effects of age or anti-spastic medication. Change scores in the Pediatric Evaluation of Disability Inventory (PEDI) ranged 2.0-6.7, p < 0.01 in the Self-care domain of the Functional Skills dimension, and the Self-care and Mobility domains of the Caregiver Assistance dimension. The children's individual goals were on average attained, Mean Goal Attainment Scaling (GAS) T-score being 51.3. Non-significant improved scores on the Gross Motor Performance Measure (GMPM) and the Quality of Upper Extremities Skills Test (QUEST) were demonstrated. Significant improvement in GMPM scores were found in improved items of the GMFM, not in items that maintained the same score. Conclusions: Basic motor abilities and self-care improved in young children with CP after goal-directed activityfocused physiotherapy with involvement of their local environment, and their need for caregiver assistance in self-care and mobility decreased. The individualized training within a group context during a limited period of time was feasible and well-tolerated. The coherence between acquisition of basic motor abilities and quality of movement should be further examined

    Clinical evaluation of restoration margins by an endoscopic microscope.

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    A method is presented for high magnification, clinical examination and recording of the marginal fit of dental restorations. An endoscopic microscope used in conjunction with video recording facilities affords acceptable colour records of restorative procedures for monitoring purposes. The suggestion is made that the concept of 'fit' in the clinical context has not been adequately addressed. The technique described has other clinical and research implications

    Complications liées aux piercings [Complications of body piercing].

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    Au sein de la population générale, de plus en plus de personnes arborent des piercings, en particulier parmi les jeunes adultes. Hormis les réactions inflammatoires et les infections locales, les complications liées à ces piercings sont méconnues. Les personnes ne sont en général pas informées des risques avant de réaliser un piercing et leurs antécédents, traitements médicamenteux ou comorbidités éventuelles, sont largement négligés par les personnes qui réalisent le geste. Les complications sont le plus souvent locales et bénignes, mais des complications sérieuses et parfois mortelles ont été décrites dans la littérature. Cet article propose une revue des problématiques possibles auxquelles pourrait être confronté un médecin de premier recours, face à un patient qui souhaiterait réaliser un piercing ou présenterait des complications suite à la mise en place d'un tel dispositif. The trend of body piercing has grown in popularity in the past decade within the general population and especially among young adults. Complications of body piercing include local inflammation and infections, but severe complications are also possible and largely underestimated. People are usually not aware of the risks before making a piercing, and their medical history, medication and comorbidities are largely neglected by the people who realise the piercing. This article presents a review of the complications that a primary care physician may observe, for a patient who wishes to make a piercing, or presents complications due to the implementation of such a device

    Precarious solidarities: ‘poisonous knowledge’ and the Academics for Peace in times of authoritarianism

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    Based on the case of Academics for Peace (BAK) in Turkey, this article reveals the conditions and trajectories that constitute precariousness and solidarity in the academic context of Turkey and the United Kingdom. Reflecting on a self‐ethnographic narrative, the main focus of the article revolves around the question of how to live an academic life when what we do and what we produce is perceived by both the public and the state as acts of potential threat to the integrity of nations and the well‐being of societies. What types of solidarity and forms of vulnerability and resilience emerge from these situations? How might the production of knowledge be transformed into a means and a place of solidarity? In the context of these questions, the article continues the search for possibilities that could emerge from precarious conditions and lead to another ethics or policy of coexistence in/outside the academic world
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