Parametric Hull Design with Rational Bézier Curves and Estimation of Performances

In this paper, a tool able to support the sailing yacht designer during the early stage of the design process has been developed. Cubic Rational Bézier curves have been selected to describe the main curves defining the hull of a sailing yacht. The adopted approach is based upon the definition of a set of parameters, say the length of waterline, the beam of the waterline, canoe body draft and some dimensionless coefficients according to the traditional way of the yacht designer. Some geometrical constraints imposed on the curves (e.g., continuity, endpoint angles, curvature) have been conceived aimed to avoid unreasonable shapes. These curves can be imported into any commercial Computer Aided Design (CAD) software and used as a frame to fit with a surface. The resistance of the hull can be calculated and plotted in order to have a real time estimation of the performances. The algorithm and the related Graphical User Interface (GUI) have been written in Visual Basic for Excel. To test the usability and the precision of the tool, two existing sailboats with different characteristics have been successfully replicated and a new design, taking advantages of both the hulls, has been developed. The new design shows good performances in terms of resistance values in a wide range of Froude numbers with respect to the original hulls

Parametric Hull Design with Rational Bézier Curves

AbstractIn this paper, a tool able to support the sailing yacht designer during the early stage of the design process has been developed. Quadratic and cubic Rational Bézier curves have been selected to describe the main curves defining the hull of a sailing yacht. The adopted approach is based upon the definition of a set of parameters, say the length of water line, the beam of the waterline, canoe body draft and some dimensionless coefficients according to the traditional way of the yacht designer. Some geometrical constraints imposed on the curves (e.g. continuity, endpoint angles) have been conceived aimed to avoid unreasonable shapes. These curves can be imported in any commercial CAD software and used as a frame to fit with a surface. The algorithm and the related Graphical User Interface (GUI) have been written in Visual Basic for Excel. To test the usability and the precision of the tool, two sailboats with different characteristics have been replicated. The rebuilt version of the hulls is very close to the original ones both in terms of shape and dimensionless coefficients

Topology Optimization Design of Internal Reinforcements in a Sailing Dinghy

AbstractIn this paper, a novel approach has been followed based on FEM simulation and Topology Optimization tools to locate and model the reinforcements inside the hull of a sailing dinghy. This process assumes that the inner volume included between the hull and the deck is, at the beginning of the simulation, filled with material; then a portion of this inner volume is eroded until a final free form shape of the reinforcements is obtained. A key point of this procedure is the definition of the optimization constrains because the final shape of the reinforcements must fulfill several requirements such as weight, stiffness and stress. At the end of the optimization procedure, the final shape of internal reinforcements consists of a truss-like web frame with a final weight equal to the 18% of the initial full body

Lo sviluppo dei sistemi di trasporto stradale e dell’incidentalità nei paesi a basso e medio reddito

Questo articolo presenta lo sviluppo dei sistemi di trasporto stradale e dell’incidentalità nei paesi a basso e medio reddito, prendendo l’Africa come un caso di studio, basato sui risultati del progetto SaferAfrica. Il Progetto SaferAfrica mira a stabilire una piattaforma di dialogo tra Africa ed Europa. Ciò è incentrato sulle questioni di sicurezza stradale e di gestione del traffico con l’obiettivo principale di fornire raccomandazioni per l’aggiornamento del piano d’azione per la sicurezza stradale africana, nonché di supportare i responsabili politici e le parti interessate con prove su fattori di rischio critici, azioni correlate e buone pratiche tratte da dati e conoscenze di qualità. Successivamente, il documento si focalizza sulla relazione tra della sicurezza stradale e livelli di reddito, la sicurezza stradale e livello di motorizzazione, e il trend di lungo periodo degli incidenti stradali nei paesi a basso e medio reddito.This paper presents the development of road transport systems and road traffic crashes rates in developing countries, taking Africa as a case study based on the results of the SaferAfrica project. The SaferAfrica EC funded project aims at establishing a Dialogue Platform between Africa and Europe. This is focused on road safety and traffic management issues with the main objective of providing recommendations to update the African Road Safety Action Plan, as well as supporting policymakers and stakeholders with evidence on critical risk factors, related actions, and good practices drawn from high-quality data and knowledge. Subsequently, the paper focuses on the relationship between road safety and income levels, road safety and the level of motorization, and the long- term trend of road accidents in low- and middle-income countries

The problem of women’s “road unsafety” in Africa

Different studies have indicated that demographic factors (i.e., gender, educational level, age) plays a role in driving style. Gender has been considered in relation to risky driving behaviour in young drivers and in general, it has been found that, in terms of risk behaviour in road traffic, males are more willing to take risks than female. The data from the World Health Organization finds that many more males than females are casualties of road traffic crashes in Africa. In addition, while gender issues have been considered in a number of policy areas, little progress has been made in the transport and road safety sector. In this regard, this paper explores the involvement and perception of crash risk, attitudes and behaviours of African women, involvement in road traffic accidents, and the role of women in improving safety conditions in Africa. Several data sources were considered by the study and analysed: Road traffic crash data from the WHO road safety report; data on risk perceptions and attitudes from the international ESRA survey; and data on women's participation in the SaferAfrica dialogue platform. According to WHO data, 70% of the road traffic crash fatalities were male (202,029) and 30% of the fatalities were female (84,665) in Africa. For the descriptive comparison at the country by country level using data from ESRA survey, the results show that gender differences are evident in most countries, dependent on the question being asked. Women make up just 20% of stakeholders in Africa according to data from the SaferAfrica dialogue platform

The Increasing Challenge of Multidrug-Resistant Gram-Negative Bacilli: Results of a 5-Year Active Surveillance Program in a Neonatal Intensive Care Unit

Colonization and infection by multidrug-resistant gram-negative bacilli (MDR GNB) in neonatal intensive care units (NICUs) are increasingly reported.We conducted a 5-year prospective cohort surveillance study in a tertiary NICU of the hospital "Paolo Giaccone," Palermo, Italy. Our objectives were to describe incidence and trends of MDR GNB colonization and the characteristics of the most prevalent organisms and to identify the risk factors for colonization. Demographic, clinical, and microbiological data were prospectively collected. Active surveillance cultures (ASCs) were obtained weekly. Clusters of colonization by extended spectrum β-lactamase (ESBL) producing Escherichia coli and Klebsiella pneumoniae were analyzed by conventional and molecular epidemiological tools.During the study period, 1152 infants were enrolled in the study. Prevalences of colonization by MDR GNB, ESBL-producing GNB and multiple species/genera averaged, respectively, 28.8%, 11.7%, and 3.7%. Prevalence and incidence density of colonization by MDR GNB and ESBL-producing GNB showed an upward trend through the surveillance period. Rates of ESBL-producing E coli and K pneumoniae colonization showed wide fluctuations peaking over the last 2 years. The only independent variables associated with colonization by MDR GNB and ESBL-producing organisms and multiple colonization were, respectively, the days of NICU stay (odds ratio [OR] 1.041), the days of exposure to ampicillin-sulbactam (OR 1.040), and the days of formula feeding (OR 1.031). Most clusters of E coli and K pneumoniae colonization were associated with different lineages. Ten out of 12 clusters had an outborn infant as their index case.Our study confirms that MDR GNB are an increasing challenge to NICUs. The universal once-a-week approach allowed us to understand the epidemiology of MDR GNB, to timely detect new clones and institute contact precautions, and to assess risk factors. Collection of these data can be an important tool to optimize antimicrobials use and control the emergence and dissemination of resistances in NICU

Candida SPP. Colonization in NICU: A 2-Year Surveillance Study

Introduction: Fungal infections are an important cause of increased morbidity and mortality in infants admitted to neonatal intensive care units (NICUs). In VLBW infants, Candida (C.) albicans is the third most common cause of neonatal late onset sepsis (LOS). The overall incidence of candidemia in NICU is increasing because of the longer survival and the invasive procedures related with the intensive care of extremely preterm infants. Prevention of candidemia in neonates is supported by the identification and adequate management of specific risk factors, including low birth weight, use of invasive devices, prolonged hospitalization and use of broad-spectrum antimicrobial agents. Effective prophylactic strategies have recently become available, but the identification of the best possible strategies to manage high-risk infants is still a priority. Prior colonization is a key risk factor for candidemia. For this reason, surveillance studies to monitor incidence, species distribution, and antifungal susceptibility profiles are mandatory. Materials and Methods: In 2013 and 2014, we performed a cohort, prospective surveillance study in our NICU, collecting weekly nasal and rectal swabs. For each patient, clinical and demographic data expected to affect Candida colonization were recorded. We evaluated Candida spp. colonization rate and assessed the related risk factors. Swabs were placed on Sabouraud agar and incubated at 30°C for 4 days. Candida growth on agar was confirmed by microscopic observation. Moreover, Candida spp. were identified through Candida chromogenic agar (ChromAgar Candida, Laboratorios Conda) and API® 20C AUX (Biomérieux). Statistical analysis was performed by EpiInfo (CDC software) using the chi square or the Fisher’s exact method, when indicated. We assumed as statistically significant a p-value < 0.05. Results: In this 2-year study, we enrolled 520 patients and we analyzed 1,259 nasal and 1,255 rectal swabs. From 472 out of 520 patients we collected complete microbiological, clinical and demographic data. 48 out of 472 (10.17%) patients tested positive for Candida spp. at least once. In particular, 26 patients tested positive for C. albicans, 16 for C. parapsilosis, 6 for C. glabrata and 1 each for C. guilliermondii and an environmental mold. All the colonized patients had their rectal samples positive, and 7 their nasal samples as well. 15 patients out of 472 (3.18%) had more than one rectal or nasal swab positive during their NICU stay. Importantly, 9 patients out of 15 tested negative at the first sampling, suggesting that they have acquired Candida spp. colonization during their stay. Table 1 summarizes data about risk factors for Candida colonization in the patients under study. No systemic infection by Candida spp. was reported during the study. Conclusion: Our experience suggest that an effective microbiological surveillance can allow for implementing proper, effective and timely control measures in a high-risk setting

Dissemination of patient blood management practices in Swiss intensive care units: a cross-sectional survey

BACKGROUND Patient blood management (PBM) promotes the routine detection and treatment of anaemia before surgery, optimising the management of bleeding disorders, thus minimising iatrogenic blood loss and pre-empting allogeneic blood utilisation. PBM programmes have expanded from the elective surgical setting to nonsurgical patients, including those in intensive care units (ICUs), but their dissemination in a whole country is unknown. METHODS We performed a cross-sectional, anonymous survey (10 October 2018 to 13 March 2019) of all ordinary medical members of the Swiss Society of Intensive Care Medicine and the registered ICU nurses from the 77 certified adult Swiss ICUs. We analysed PBM-related interventions adopted in Swiss ICUs and related them to the spread of PBM in Swiss hospitals. We explored blood test ordering policies, blood-sparing strategies and red blood cell-related transfusion practices in ICUs. RESULTS A total of 115 medical doctors and 624 nurses (response rates 27% and 30%, respectively) completed the surveys. Hospitals had implemented a PBM programme according to 42% of physicians, more commonly in Switzerland's German-speaking regions (Odds Ratio [OR] 3.39, 95% confidence interval [CI] 1.23-9.35; p = 0.018) and in hospitals with more than 500 beds (OR 3.91, 95% CI 1.48-10.4; p = 0.006). The PBM programmes targeted the detection and correction of anaemia before surgery (79%), minimising perioperative blood loss (94%) and optimising anaemia tolerance (98%). Laboratory tests were ordered in 70.4% by the intensivist during morning rounds; the nurses performed arterial blood gas analyses autonomously in 48.4%. Blood-sparing techniques were used by only 42.1% of nurses (263 of 624, missing: 6) and 47.0% of physicians (54 of 115). Approximately 60% of respondents used an ICU-specific transfusion guideline. The reported haemoglobin threshold for the nonbleeding ICU population was 70 g/l and, therefore, was at the lower limit of current guidelines. CONCLUSIONS Based on this survey, the estimated proportion of the intensivists working in hospitals with a PBM initiative is 42%, with significant variability between regions and hospitals of various sizes. The risk of iatrogenic anaemia is relevant due to liberal blood sample collection practices and the underuse of blood-sparing techniques. The reported transfusion threshold suggests excellent adherence to current international ICU-specific transfusion guidelines

A Snapshot on MRSA epidemiology in a neonatal intensive care unit network, Palermo, Italy

Objectives: We performed a 1-year prospective surveillance study on MRSA colonization within the five NICUs of the metropolitan area of Palermo, Italy. The purpose of the study was to assess epidemiology of MRSA in NICU from a network perspective. Methods: Transfer of patients between NICUs during 2014 was traced based on the annual hospital discharge records. In the period February 2014-January 2015, in the NICU B, at the University teaching hospital, nasal swabs from all infants were collected weekly, whereas in the other four NICUs (A, C, D, E) at 4 week-intervals of time. MRSA isolates were submitted to antibiotic susceptibility testing, SCCmec typing, PCR to detect lukS-PV and lukF-PV (lukS/F-PV) genes and the gene encoding the toxic shock syndrome toxin (TSST-1), multilocus variable number tandem repeat fingerprinting (MLVF), and multilocus sequence typing (MLST). Results: In the period under study, 587 nasal swabs were obtained from NICU B, whereas 218, 180, 157, and 95 from NICUs A, C, D, and E, respectively. Two groups of NICUs at high prevalence and low prevalence of MRSA colonization were recognized. Overall, 113 isolates of MRSA were identified from 102 infants. Six MLVF types (A-F) were detected, with type C being subdivided into five subtypes. Five sequence types (STs) were found with ST22-IVa being the most frequent type in all NICUs. All the MRSA molecular subtypes, except for ST1-IVa, were identified in NICU B. Conclusions: Our findings support the need to approach surveillance and infection control in NICU in a network perspective, prioritizing referral healthcare facilities

Telecardiology and Remote Monitoring of Implanted Electrical Devices: The Potential for Fresh Clinical Care Perspectives

Telecardiology may help confront the growing burden of monitoring the reliability of implantable defibrillators/pacemakers. Herein, we suggest that the evolving capabilities of implanted devices to monitor patients’ status (heart rhythm, fluid overload, right ventricular pressure, oximetry, etc.) may imply a shift from strictly device-centered follow-up to perspectives centered on the patient (and patient-device interactions). Such approaches could provide improvements in health care delivery and clinical outcomes, especially in the field of heart failure. Major professional, policy, and ethical issues will have to be overcome to enable real-world implementation. This challenge may be relevant for the evolution of our health care systems