6 research outputs found

    THE GROUND LEVEL CONCENTRATION FROM A POINT SOURCE

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    The Advection-Diffusion Equation (ADE) is solved for a constant pollutant emission from a point-like source placed inside an unstable Atmospheric Boundary Layer (ABL). The solution is obtained adopting the novel analytical approach named Generalized Integral Laplace Transform Technique (GILTT). The concentration solution of the equation is expressed through an infinite series expansion. After setting a realistic scenario through the wind and diffusivity parameterizations the Ground Level Concentration (GLC) is worked out, then an explicit approximate expression is provided for it allowing an analytic simple expression for the position and value of the maximum. Remarks arise on the ability to express value and position of the GLC as an explicit function of the parameters defining the ABL scenario and the source height

    An Analytical Simple Formula for the Ground Level Concentration from a Point Source

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    The Advection-Diffusion Equation is solved for a constant pollutant emission from a point-like source placed inside an unstable Atmospheric Boundary Layer. The solution is obtained adopting the novel analytical approach: Generalized Integral Laplace Transform Technique. The concentration solution of the equation is expressed through an infinite series expansion. After setting a realistic scenario through the wind and diffusivity parameterizations, the Ground Level Concentration (GLC) is determined, and an explicit approximate expression is provided for it, allowing an analytically simple expression for the position and value of the maximum. Remarks arise regarding the ability to express value and position of the GLC as explicit functions of the parameters defining the Atmospheric Boundary Layer scenario and the source height

    CMEMS-Based coastal analyses: Conditioning, coupling and limits for applications

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    Recent advances in numerical modeling, satellite data, and coastal processes, together with the rapid evolution of CMEMS products and the increasing pressures on coastal zones, suggest the timeliness of extending such products toward the coast. The CEASELESS EU H2020 project combines Sentinel and in-situ data with high-resolution models to predict coastal hydrodynamics at a variety of scales, according to stakeholder requirements. These predictions explicitly introduce land discharges into coastal oceanography, addressing local conditioning, assimilation memory and anisotropic error metrics taking into account the limited size of coastal domains. This article presents and discusses the advances achieved by CEASELESS in exploring the performance of coastal models, considering model resolution and domain scales, and assessing error generation and propagation. The project has also evaluated how underlying model uncertainties can be treated to comply with stakeholder requirements for a variety of applications, from storm-induced risks to aquaculture, from renewable energy to water quality. This has led to the refinement of a set of demonstrative applications, supported by a software environment able to provide met-ocean data on demand. The article ends with some remarks on the scientific, technical and application limits for CMEMS-based coastal products and how these products may be used to drive the extension of CMEMS toward the coast, promoting a wider uptake of CMEMS-based predictions

    Internet and social media use among patients with colorectal diseases (ISMAEL): a nationwide survey

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    Aim: Social media are used daily by both healthcare workers and patients. Online platforms have the potential to provide patients with useful information, increase their engagement and potentially revolutionize the patient-physician relationship. This survey aimed to evaluate the impact of the Internet and social media (I&SM) on patients affected by colorectal and proctological diseases to define a pathway to develop an evidence-based communications strategy. Method: A 31-item anonymous electronic questionnaire was designed. It consisted of different sections concerning demographics and education, reason for the visit, knowledge of the diseases, frequency of I&SM use and patients' opinions about physicians' websites. Results: Over a 5-month period, 37 centres and 105 surgeons took part in the survey, and a total of 5800 patients enrolled. Approximately half of them reported using the Internet daily, and 74.6% of the study population used it at least once per week. There was a correlation (P < 0.001) between those who used the Internet for work and those who had knowledge of both symptoms and the likely diagnosis before consultation. Patients who used the Internet daily were more likely to request a consultation within 6 months of symptom onset (P < 0.0001). Patients with anorectal diseases were more likely to know about their disease and symptoms before the visit (P < 0.001). Conclusion: Colorectal patients use I&SM to look for health-related information mainly after their medical visit. Surgeons and hospital networks should plan a tailored strategy to increase patient engagement, delivering appropriate information on social medi

    Internet and social media use among patients with colorectal diseases (ISMAEL): a nationwide survey

    Get PDF
    Aim: Social media are used daily by both healthcare workers and patients. Online platforms have the potential to provide patients with useful information, increase their engagement and potentially revolutionize the patient–physician relationship. This survey aimed to evaluate the impact of the Internet and social media (I&SM) on patients affected by colorectal and proctological diseases to define a pathway to develop an evidence-based communications strategy. Method: A 31-item anonymous electronic questionnaire was designed. It consisted of different sections concerning demographics and education, reason for the visit, knowledge of the diseases, frequency of I&SM use and patients' opinions about physicians' websites. Results: Over a 5-month period, 37 centres and 105 surgeons took part in the survey, and a total of 5800 patients enrolled. Approximately half of them reported using the Internet daily, and 74.6% of the study population used it at least once per week. There was a correlation (P < 0.001) between those who used the Internet for work and those who had knowledge of both symptoms and the likely diagnosis before consultation. Patients who used the Internet daily were more likely to request a consultation within 6 months of symptom onset (P < 0.0001). Patients with anorectal diseases were more likely to know about their disease and symptoms before the visit (P < 0.001). Conclusion: Colorectal patients use I&SM to look for health-related information mainly after their medical visit. Surgeons and hospital networks should plan a tailored strategy to increase patient engagement, delivering appropriate information on social media

    Delayed colorectal cancer care during covid-19 pandemic (decor-19). Global perspective from an international survey

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    Background The widespread nature of coronavirus disease 2019 (COVID-19) has been unprecedented. We sought to analyze its global impact with a survey on colorectal cancer (CRC) care during the pandemic. Methods The impact of COVID-19 on preoperative assessment, elective surgery, and postoperative management of CRC patients was explored by a 35-item survey, which was distributed worldwide to members of surgical societies with an interest in CRC care. Respondents were divided into two comparator groups: 1) ‘delay’ group: CRC care affected by the pandemic; 2) ‘no delay’ group: unaltered CRC practice. Results A total of 1,051 respondents from 84 countries completed the survey. No substantial differences in demographics were found between the ‘delay’ (745, 70.9%) and ‘no delay’ (306, 29.1%) groups. Suspension of multidisciplinary team meetings, staff members quarantined or relocated to COVID-19 units, units fully dedicated to COVID-19 care, personal protective equipment not readily available were factors significantly associated to delays in endoscopy, radiology, surgery, histopathology and prolonged chemoradiation therapy-to-surgery intervals. In the ‘delay’ group, 48.9% of respondents reported a change in the initial surgical plan and 26.3% reported a shift from elective to urgent operations. Recovery of CRC care was associated with the status of the outbreak. Practicing in COVID-free units, no change in operative slots and staff members not relocated to COVID-19 units were statistically associated with unaltered CRC care in the ‘no delay’ group, while the geographical distribution was not. Conclusions Global changes in diagnostic and therapeutic CRC practices were evident. Changes were associated with differences in health-care delivery systems, hospital’s preparedness, resources availability, and local COVID-19 prevalence rather than geographical factors. Strategic planning is required to optimize CRC care
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