75 research outputs found

    Evaluating clinician acceptability of the prototype CanRisk tool for predicting risk of breast and ovarian cancer: A multi-methods study.

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    BACKGROUND:There is a growing focus on the development of multi-factorial cancer risk prediction algorithms alongside tools that operationalise them for clinical use. BOADICEA is a breast and ovarian cancer risk prediction model incorporating genetic and other risk factors. A new user-friendly Web-based tool (CanRisk.org) has been developed to apply BOADICEA. This study aimed to explore the acceptability of the prototype CanRisk tool among two healthcare professional groups to inform further development, evaluation and implementation. METHOD:A multi-methods approach was used. Clinicians from primary care and specialist genetics clinics in England, France and Germany were invited to use the CanRisk prototype with two test cases (either face-to-face with a simulated patient or via a written vignette). Their views about the tool were examined via a semi-structured interview or equivalent open-ended questionnaire. Qualitative data were subjected to thematic analysis and organised around Sekhon's Theoretical Framework of Acceptability. RESULTS:Seventy-five clinicians participated, 21 from primary care and 54 from specialist genetics clinics. Participants were from England (n = 37), France (n = 23) and Germany (n = 15). The prototype CanRisk tool was generally acceptable to most participants due to its intuitive design. Primary care clinicians were concerned about the amount of time needed to complete, interpret and communicate risk information. Clinicians from both settings were apprehensive about the impact of the CanRisk tool on their consultations and lack of opportunities to interpret risk scores before sharing them with their patients. CONCLUSIONS:The findings highlight the challenges associated with developing a complex tool for use in different clinical settings; they also helped refine the tool. This prototype may not have been versatile enough for clinical use in both primary care and specialist genetics clinics where the needs of clinicians are different, emphasising the importance of understanding the clinical context when developing cancer risk assessment tools

    Hadronization in heavy ion collisions: recombination or fragmentation?

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    We show that hadron production in relativistic heavy ion collisions at transverse momenta larger than 2 GeV/c can be explained by the competition of two different hadronization mechanisms. Above 5 GeV/c hadron production can be described by fragmentation of partons that are created perturbatively. Below 5 GeV/c recombination of partons from the dense and hot fireball dominates. This can explain some of the surprising features of RHIC data like the constant baryon-to-meson ratio of about one and the small nuclear suppression for baryons between 2 to 4 GeV/c.Comment: Contribution to the 7th Conference on Strange Quark Matter (SQM 2003), submitted to J.Phys.G; 6 pages LaTeX, 4 eps figures, uses iopart.cl

    Thermal analysis of production of resonances in relativistic heavy-ion collisions

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    Production of resonances is considered in the framework of the single-freeze-out model of ultra-relativistic heavy ion collisions. The formalism involves the virial expansion, where the probability to form a resonance in a two-body channel is proportional to the derivative of the phase-shift with respect to the invariant mass. The thermal model incorporates longitudinal and transverse flow, as well as kinematic cuts of the STAR experiment at RHIC. We find that the shape of the pi+ pi- spectral line qualitatively reproduces the preliminary experimental data when the position of the rho peak is lowered. This confirms the need to include the medium effects in the description of the RHIC data. We also analyze the transverse-momentum spectra of rho, K*(892), and f_0(980), and find that the slopes agree with the observed values. Predictions are made for eta, eta', omega, phi, Lambda(1520), and Sigma(1385).Comment: minor modifications, a reference adde

    Baryon phase-space density in heavy-ion collisions

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    The baryon phase-space density at mid-rapidity from central heavy-ion collisions is estimated from proton spectra with interferometry and deuteron coalescence measurements. It is found that the mid-rapidity phase-space density of baryons is significantly lower at the SPS than the AGS, while those of total particles (pion + baryon) are comparable. Thermal and chemical equilibrium model calculations tend to over-estimate the phase-space densities at both energies.Comment: 5 pages, 2 tables, no figure. RevTeX style. Accepted for publication in Phys. Rev. C Rapid Communicatio

    Strange particle production at RHIC in a single-freeze-out model

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    Strange particle ratios and pT-spectra are calculated in a thermal model with single freeze-out, previously used successfully to describe non-strange particle production at RHIC. The model and the recently released data for phi, Lambda, anti-Lambda, and K*(892) are in very satisfactory agreement, showing that the thermal approach can be used to describe the strangeness production at RHIC.Comment: We have added the comparison of the model predictions to the newly released Lambda and K*(892) pT-spectra from STA

    (Anti)Proton and Pion Source Sizes and Phase Space Densities in Heavy Ion Collisions

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    NA44 has measured mid-rapidity deuteron spectra from AA collisions at sqrt{s}=18GeV/A at the CERN SPS. Combining these spectra with published proton, antiproton and antideuteron data allows us to calculate, within a coalescence framework, proton and antiproton source sizes and phase space densities. These results are compared to pion source sizes and densities, pA results and to lower energy (AGS) data. The antiproton source is larger than the proton source at sqrt{s}=18GeV/A. The phase space densities of pions and protons are not constant but grow with system size. Both pi+ and proton radii decrease with transverse mass and increase with sqrt{s}. Pions and protons do not freeze-out independently. The nature of their interaction changes as sqrt{s}, and the pion/proton ratio increases.Comment: 4 pages, Latex 2.09, 3 eps figures. Changes for January 2001. The proton source size is now calculated assuming a more realistic Hulthen, rather than Gaussian, wavefunction. A new figure shows the effect of this change which is important for small radii. A second new figure shows the results of RQMD calculations of the proton source size and phase density. Because of correlations between position and momentum coalesence does not show the full proton source size. The paper has been streamlined and readability improve

    Mass dependence of light nucleus production in ultrarelativistic heavy ion collisions

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    Light nuclei can be produced in the central reaction zone via coalescence in relativistic heavy ion collisions. E864 at BNL has measured the production of ten light nuclei with nuclear number of A=1 to A=7 at rapidity y1.9y\simeq1.9 and pT/A300MeV/cp_{T}/A\leq300MeV/c. Data were taken with a Au beam of momentum of 11.5 A GeV/cGeV/c on a Pb or Pt target with different experimental settings. The invariant yields show a striking exponential dependence on nuclear number with a penalty factor of about 50 per additional nucleon. Detailed analysis reveals that the production may depend on the spin factor of the nucleus and the nuclear binding energy as well.Comment: (6 pages, 3 figures), some changes on text, references and figures' lettering. To be published in PRL (13Dec1999

    Measurements of Light Nuclei Production in 11.5 A GeV/c Au+Pb Heavy-Ion Collisions

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    We report on measurements by the E864 experiment at the BNL-AGS of the yields of light nuclei in collisions of Au(197) with beam momentum of 11.5 A GeV/c on targets of Pb(208) and Pt(197). The yields are reported for nuclei with baryon number A=1 up to A=7, and typically cover a rapidity range from y(cm) to y(cm)+1 and a transverse momentum range of approximately 0.1 < p(T)/A < 0.5 GeV/c. We calculate coalescence scale factors B(A) from which we extract model dependent source dimensions and collective flow velocities. We also examine the dependences of the yields on baryon number, spin, and isospin of the produced nuclei.Comment: 21 figures-to be published in Phys. Rev.

    Demographic, clinical and antibody characteristics of patients with digital ulcers in systemic sclerosis: data from the DUO Registry

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    OBJECTIVES: The Digital Ulcers Outcome (DUO) Registry was designed to describe the clinical and antibody characteristics, disease course and outcomes of patients with digital ulcers associated with systemic sclerosis (SSc). METHODS: The DUO Registry is a European, prospective, multicentre, observational, registry of SSc patients with ongoing digital ulcer disease, irrespective of treatment regimen. Data collected included demographics, SSc duration, SSc subset, internal organ manifestations, autoantibodies, previous and ongoing interventions and complications related to digital ulcers. RESULTS: Up to 19 November 2010 a total of 2439 patients had enrolled into the registry. Most were classified as either limited cutaneous SSc (lcSSc; 52.2%) or diffuse cutaneous SSc (dcSSc; 36.9%). Digital ulcers developed earlier in patients with dcSSc compared with lcSSc. Almost all patients (95.7%) tested positive for antinuclear antibodies, 45.2% for anti-scleroderma-70 and 43.6% for anticentromere antibodies (ACA). The first digital ulcer in the anti-scleroderma-70-positive patient cohort occurred approximately 5 years earlier than the ACA-positive patient group. CONCLUSIONS: This study provides data from a large cohort of SSc patients with a history of digital ulcers. The early occurrence and high frequency of digital ulcer complications are especially seen in patients with dcSSc and/or anti-scleroderma-70 antibodies

    Antideuteron and antihelion production in root(s) = 130 GeV Au+Au collisions

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    The first measurements of light antinucleus production in Au+Au collisions at RHIC are reported. The observed production rates for antideuterons and antihelions are much larger than in lower energy nucleus-nucleus collisions. A coalescence model analysis of the yields indicates that there is little or no increase in the antinucleon freeze-out volume compared to collisions at SPS energy. These analyses also indicate that the antihelion freeze-out volume is smaller than the antideuteron freeze-out volume.Comment: Submitted to Phys. Rev. Let
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