4,489 research outputs found

    Markovian approach to tackle the interaction of simultaneous diseases

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    The simultaneous emergence of several abrupt disease outbreaks or the extinction of some serotypes of multistrain diseases are fingerprints of the interaction between pathogens spreading within the same population. Here, we propose a general and versatile benchmark to address the unfolding of both cooperative and competitive interacting diseases. We characterize the explosive transitions between the disease-free and the epidemic regimes arising from the cooperation between pathogens and show the critical degree of cooperation needed for the onset of such abrupt transitions. For the competing diseases, we characterize the mutually exclusive case and derive analytically the transition point between the full-dominance phase, in which only one pathogen propagates, and the coexistence regime. Finally, we use this framework to analyze the behavior of the former transition point as the competition between pathogens is relaxed

    Two-parameter neutrino mass matrices with two texture zeros

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    We reanalyse Majorana-neutrino mass matrices M_nu with two texture zeros, by searching for viable hybrid textures in which the non-zero matrix elements of M_nu have simple ratios. Referring to the classification scheme of Frampton, Glashow and Marfatia, we find that the mass matrix denoted by A1 allows the ratios (M_nu)_{mu mu} : (Mnu)_{tau tau} = 1:1 and (M_nu)_{e tau} : (Mnu)_{mu tau} = 1:2. There are analogous ratios for texture A2. With these two hybrid textures, one obtains, for instance, good agreement with the data if one computes the three mixing angles in terms of the experimentally determined mass-squared differences Delta m^2_21 and Delta m^2_31. We could not find viable hybrid textures based on mass matrices different from those of cases A1 and A2.Comment: 10 pages, no figures, minor changes, some references adde

    Heart applications of 4D flow

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    Four-dimensional (4D) flow sequences are an innovative type of MR sequences based upon phase contrast (PC) sequences which are a type of application of Angio-MRI together with the Time of Flight (TOF) sequences and Contrast-Enhanced Magnetic Resonance Acquisition (CE-MRA). They share the basic principles of PC, but unlike PC sequences, 4D flow has velocity encoding along all three flow directions and three-dimensional (3D) anatomic coverage. They guarantee the analysis of flow with multiplanarity on a post-processing level, which is a unique feature among MR sequences. Furthermore, this technique provides a completely new level to the in vivo flow analysis as it allows measurements in never studied districts such as intracranial applications or some parts of the heart never studied with echo-color-doppler, which is its sonographic equivalent. Furthermore, this technique provides a completely new level to the in vivo flow analysis as it allows accurate measurement of the flows in different districts (e.g., intracranial, cardiac) that are usually studied with echo-color-doppler, which is its sonographic equivalent. Of note, the technique has proved to be affected by less inter and intra-observer variability in several application. 4D-flow basic principles, advantages, limitations, common pitfalls and artefacts are described. This review will outline the basis of the formation of PC image, the construction of a 4D-flow and the huge impact the technique is having on the cardiovascular non-invasive examination. It will be then studied how this technique has had a huge impact on cardiovascular examinations especially on a central heart level

    Flavour and polarisation in heavy neutrino production at e+ e- colliders

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    We analyse l W nu production at ILC, paying special attention to the role of the final lepton flavour and beam polarisation in the search for a new heavy neutrino N. We show that a sizeable coupling to the electron V_eN ~ 10^-2 is necessary to have an observable signal in any of the channels, despite the fact that the signal may be more visible in muon or tau final states. The non-observation of a heavy neutrino at ILC will improve the present upper bound on its mixing with the electron by more than one order of magnitude, V_eN < 0.007 for m_N between 200 and 400 GeV.Comment: 17 pages, 5 PS figures. References added. To be published in PL

    Large theta_13 from a model with broken L_e-L_mu-L_tau symmetry

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    Recent data in the neutrino sector point towards a relatively large value of the reactor angle, incompatible with a vanishing theta_ 13 at about 3 sigma. In order to explain such a result, we propose a SUSY model based on the broken L_e-L_mu-L_tau symmetry, where large deviations from the symmetric limit theta_12 = pi/4, tan(theta_23) \sim O(1) and theta_13 = 0 mainly come from the charged lepton sector. We show that a description of all neutrino data is possible if the charged lepton mass matrix has a special pattern of complex matrix elements.Comment: 9 pages, 2 figures. v2: comments and references added, as published in JHE

    Patient Involvement in Shared Decision-Making: Do Patients Rate Physicians and Nurses Differently?

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    Background. Shared decision-making implies that patients and healthcare professionals make decisions together about clinical exams, available treatments, choice of options, and the benefit or downside of every choice. Patients involved in the shared decision-making process are more compliant with treatments and have a reduced risk of complications related to the pathology. In Italy, patient involvement in caring processes is still barely investigated. Aim. To investigate patients’ perceptions about shared decision-making with physicians and nurses, respectively, and to examine the relationship between shared decision-making and patient satisfaction and perceived quality of care/treatment. Methods. The study was performed between March and June 2019 in two wards of one Italian hospital. A questionnaire was administered to inpatients at the time of admission and again at discharge, including demographic information and measurement scales regarding patient involvement in shared decision-making, patient satisfaction, and perceived quality of treatment/care. Results. A total of 151 out of 301 patients completed questionnaires at both admission and discharge. Patients’ scores for shared decision-making (information, patient needs, treatment planning) were significantly different for physicians and nurses. At both admission and discharge, patients rated shared decision-making significantly higher for physicians compared to nurses, while there were no differences in their satisfaction ratings. Patient ratings of physicians did not change from admission (information: mean (M) = 3.50, standard deviation (SD) = 0.81; patient need: M = 3.05, SD = 1.05; treatment planning: M = 2.75, SD = 1.23) to discharge (information: M = 3.50, SD = 0.79; patient need: M = 3.17, SD = 1.02; treatment planning: M = 2.66, SD = 1.23) (p = 0.924, p = 0.098, p = 0.293, respectively), but patients’ ratings of nurses’ behavior increased significantly from admission (information: M = 2.44, SD = 1.23; patient need: M = 2.27, SD = 1.17; treatment planning: M = 2.12, SD = 1.19) to discharge (information: M = 2.62, SD = 1.22; patient need: M = 2.53, SD = 1.24; treatment planning: M = 2.35, SD = 1.21) (p = 0.019, p = 0.001, p = 0.003, respectively). Attention to patients’ needs was the key determinant of both satisfaction with nurses (OR = 3.65, 95% CI = 1.31–10.14, p = 0.013) and perceived quality of care (OR = 3.97, 95% CI = 1.49–10.55, p = 0.006). Providing appropriate information about disease progress and treatments was a key determinant of both satisfaction with physicians (OR = 19.75, 95% CI = 7.29–53.55, p &lt; 0.001) and perceived quality of treatment (OR = 8.03, 95% CI = 3.25–19.81, p &lt; 0.001). Discussion. Nurses should be sensitized to involving patients in the decision-making process, especially upon hospital admission. Specific training about effective communication techniques can be implemented to manage relationships with patients in different caring situations. Practical implications and future directions are discussed

    To Splint or Not to Splint Short Dental Implants Under the Same Partial Fixed Prosthesis? One-year Post-loading Data From a Multicentre Randomised Controlled Trial

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    PURPOSE. To compare the clinical outcomes of two adjacent 6-mm-long dental implants splinted under the same prosthesis (control group) versus two identical implants sup-porting single crowns (test group). MATERIALS AND METHODS. Forty-seven patients with edentulous posterior (premolars and/or molars) jaws received two adjacent 6-mm-long dental implants, which were sub-merged. Four months later, at impression taking, patients were randomised to receive splinted or unsplinted definitive cemented metal-composite prostheses. Unfortunately, four patients died before randomisation and three patients lost five implants, so only 40 patients were randomised, according to a parallel-group design, to have both implants splinted under the same partial fixed prosthesis (19 patients) or with two single crowns (21 patients). Outcome measures were: prosthesis and implant failures, any complica-tions, peri-implant marginal bone level changes and patient satisfaction. Patients were followed-up to 1 year after loading. RESULTS. One patient from the splinted group dropped out. No implant failures occurred after randomisation. One complication occurred in the unsplinted group versus no complications at splinted implants, the difference not being statistically different (Fisher’s exact test P = 1.000; difference in proportions =-0.04; 95% CI-0.16 to 0.09). Both groups presented significant peri-implant marginal bone loss at 1 year after loading (P<0.05), respectively-0.36 (0.45) mm at splinted implants and-0.17 (0.31) mm at unsplinted implan-ts, but there were no statistically significant differences between the two groups (mean difference 0.19 mm; 95% CI-0.10 to 0.48; P = 0.194). All patients were fully or reasonably satisfied with the treatment, with the exception of two patients, both from the splinted group: one patient was not sure about the aesthetics, and another would not undergo the same treatment again. CONCLUSIONS. The present data seems to suggest that up to 1 year after loading the prognosis of short implants, mostly placed in mandibles characterised by dense bone quality, may not be influenced by splinting or not under the same fixed prostheses. Howe-ver, these preliminary results need to be confirmed by larger trials with follow-ups of at least 5 years

    Accidental stability of dark matter

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    We propose that dark matter is stable as a consequence of an accidental Z2 that results from a flavour-symmetry group which is the double-cover group of the symmetry group of one of the regular geometric solids. Although model-dependent, the phenomenology resembles that of a generic Higgs portal dark matter scheme.Comment: 12 pages, final version, published in JHE

    Haemolymphatic cancer among children in Sardinia, Italy: 1974-2003 incidence

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    Objectives To explore the time trend and geographical distribution of childhood leukaemia incidence over the territory of the Italian region of Sardinia. Setting All hospitals departments, diagnostic centres and social security agencies in Sardinia were regularly screened in 1974-2003 to identify, register and review the diagnoses of incident cases of haematological malignancies (HM). Participants The whole child population aged 0-14 resident in Sardinia. Primary and secondary outcome measures Incidence and time trend of childhood HM and childhood acute lymphoblastic leukaemia (ALL) over the study period, and use of Bayesian methods to plot the probability of areas with excess incidence on the regional map. Results Overall, 675 HM cases, including 378 ALL cases, occurred among children aged 0-14 years resident in Sardinia in 1974-2003, with an incidence rate of 6.97×10-5 (95% CI 6.47 to 7.51) and 3.85×10-5 (95% CI 3.48 to 4.26), respectively. Incidence of HM and ALL showed an upward trend along the study period especially among females. Three communes out of the 356 existing in 1974, namely Ittiri, Villa San Pietro and Carbonia, stand out as areas with excess incidence of HM and ALL in particular and another, Carloforte, for ALL only. Conclusions Our results might serve as convincing arguments for extending the coverage of routine cancer registration over the whole Sardinian population, while prompting further research on the genetic and environmental determinants in the areas at risk
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