31 research outputs found

    Analysis and implementation of the multiprocessor bandwidth inheritance protocol

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    The Multiprocessor Bandwidth Inheritance (M-BWI) protocol is an extension of the Bandwidth Inheritance (BWI) protocol for symmetric multiprocessor systems. Similar to Priority Inheritance, M-BWI lets a task that has locked a resource execute in the resource reservations of the blocked tasks, thus reducing their blocking time. The protocol is particularly suitable for open systems where different kinds of tasks dynamically arrive and leave, because it guarantees temporal isolation among independent subsets of tasks without requiring any information on their temporal parameters. Additionally, if the temporal parameters of the interacting tasks are known, it is possible to compute an upper bound to the interference suffered by a task due to other interacting tasks. Thus, it is possible to provide timing guarantees for a subset of interacting hard real-time tasks. Finally, the M-BWI protocol is neutral to the underlying scheduling policy: it can be implemented in global, clustered and semi-partitioned scheduling. After introducing the M-BWI protocol, in this paper we formally prove its isolation properties, and propose an algorithm to compute an upper bound to the interference suffered by a task. Then, we describe our implementation of the protocol for the LITMUS RT real-time testbed, and measure its overhead. Finally, we compare M-BWI against FMLP and OMLP, two other protocols for resource sharing in multiprocessor systems

    On the integration of application level and resource level QoS control for real-time applications

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    We consider a dynamic set of soft real-time applications using a set of shared resources. Each application can execute in different modes, each one associated with a level of Quality of Service (QoS). Resources, in their turn, have different modes, each one with a speed and a power consumption, and are managed by a Reservation Based scheduler enabling a dynamic allocation of the fraction of resources (bandwidth) assigned to each application. To cope with dynamic changes of the application, we advocate an adaptive resource allocation policy organised in two nested feedback loops. The internal loop operates on the scheduling parameter to obtain a resource allocation that meets the temporal constraints of the applications. The external loop operates on the QoS level of the applications and on the power level of the resources to strike a good trade-off between the global QoS and the energy consumption. This loop comes into play whenever the workload of the application exceeds the bounds that permit the internal loop to operate correctly, or whenever it decreases below a level that permit more aggressive choices for the QoS or substantial energy saving

    Sexually Transmitted Diseases: Diagnosis and Control

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    : Sexually transmitted diseases (STDs)-or sexually transmitted infections (STIs)-are generally acquired through sexual contact [...]

    Modular software architecture for flexible reservation mechanisms on heterogeneous resources

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    Management, allocation and scheduling of heterogeneous resources for complex distributed real-time applications is a chal- lenging problem. Timing constraints of applications may be fulfilled by a proper use of real-time scheduling policies, admission control and enforcement of timing constraints. However, it is not easy to design basic infrastructure services that allow for an easy access to the allocation of multiple heterogeneous resources in a distributed environment. In this paper, we present a middleware for providing distributed soft real-time applications with a uniform API for reserving heterogeneous resources with real-time scheduling capabilities in a distributed environment. The architecture relies on standard POSIX OS facilities, such as time management and standard TCP/IP networking services, and it is designed around CORBA, in order to facilitate modularity, flexibility and portability of the applications using it. However, real-time scheduling is supported by proper extensions at the kernel-level, plugged within the framework by means of dedicated resource managers. Our current implementation on Linux supports reservation of CPU, disk and network bandwidth. However, additional resource managers supporting alternative real-time schedulers for these resources, as well as additional types of resources, may be easily added. We present experimental results gathered on both synthetic applications and a real multimedia video streaming case study, showing advantages deriving from the use of the proposed middleware. Finally, overhead figures are reported, showing sustainability of the approach for a wide class of complex, distributed, soft real-time applications

    Helicobacter pylori and Epstein-Barr virus infection in gastric diseases: Correlation with IL-10 and IL1RN polymorphism.

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    Introduction: Helicobacter pylori and Epstein-Barr virus (EBV) infection have recently 23 been shown to be associated with gastric diseases. Polymorphisms in genes encoding 24 cytokines such as interleukin 10 (IL-10) and interleukin 1 Receptor (IL-1RN) influence 25 cytokine secretion levels and appear to contribute to the risk of developing gastroduodenal 26 diseases. 27 To our knowledge, this is the first preliminary study to address the association of 28 coinfection with H. pylori and EBV and their correlation with genetic predisposition in the 29 development of gastric diseases. 30 Methods: Gastric biopsy samples of 96 patients with different gastric diseases were used. 31 Results: Our results showed that the rate of co-infection was higher in patients with 32 gastric cancer than in patients with normal gastric mucosa, active chronic gastritis and 33 MALT lymphoma. As regards the characterization of H. pilory strains, the 34 polymorphism s1m1i1 of vacA gene was more frequent in patients with MALT 35 Lymphoma in comparison to others, while the polymorphism s2m2i2 was most 36 frequent in patients with normal gastric mucosa. In addition, patients who tested 37 positivefor the cagA gene were more frequently those affected with gastric cancer than 38 those with inactive chronic gastritis. Similarly, the patients with oipA gene ON were more 39 frequently those with gastric cancer than those with inactive chronic gastritis. 40 Conclusion: According to our analysis, there was no correlation between coinfection 41 and polymorphisms in genes encoding IL-10 and IL-1RN. We conclude that various 42 factors can be involved in the development of gastric diseases

    On the integration of application level and resource level QoS control for realtime applications

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    Abstract We consider a dynamic set of soft real-time applications using a set of shared resources. Each application can execute in different modes, each one associated with a level of Quality of Service (QoS). Resources, in their turn, have different modes, each one with a speed and a power consumption, and are managed by a Reservation Based scheduler enabling a dynamic allocation of the fraction of resources (bandwidth) assigned to each application. To cope with dynamic changes of the application, we advocate an adaptive resource allocation policy organised in two nested feedback loops. The internal loop operates on the scheduling parameter to obtain a resource allocation that meets the temporal constraints of the applications. The external loop operates on the QoS level of the applications and on the power level of the resources to strike a good trade-off between the global QoS and the energy consumption. This loop comes into play whenever the workload of the application exceeds the bounds that permit the internal loop to operate correctly, or whenever it decreases below a level that permit more aggressive choices for the QoS or substantial energy saving

    Surveillance of Influenza and Other Airborne Transmission Viruses during the 2021/2022 Season in Hospitalized Subjects in Tuscany, Italy

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    Winter in the northern hemisphere is characterized by the circulation of influenza viruses, which cause seasonal epidemics, generally from October to April. Each influenza season has its own pattern, which differs from one year to the next in terms of the first influenza case notification, the period of highest incidence, and the predominant influenza virus subtypes. After the total absence of influenza viruses in the 2020/2021 season, cases of influenza were again recorded in the 2021/2022 season, although they remained below the seasonal average. Moreover, the co-circulation of the influenza virus and the SARS-CoV-2 pandemic virus was also reported. In the context of the DRIVE study, oropharyngeal swabs were collected from 129 Tuscan adults hospitalized for severe acute respiratory infection (SARI) and analyzed by means of real-time polymerase chain reaction (RT-PCR) for SARS-CoV-2 and 21 different airborne pathogens, including influenza viruses. In total, 55 subjects tested positive for COVID-19, 9 tested positive for influenza, and 3 tested positive for both SARS-CoV-2 and the A/H3N2 influenza virus. The co-circulation of different viruses in the population requires strengthened surveillance that is no longer restricted to the winter months. Indeed, constant, year-long monitoring of the trends of these viruses is needed, especially in at-risk groups and elderly people

    There is a correlation between nutritional status, Self-Rated Health and Life Satisfaction? Evidence from 2018 Health Behaviour in School-aged Children cross sectional study in a sample of Italian Adolescents living in Tuscany Region

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    Background: Overweight has been associated with several social and phycological problems and is perceived as one of the major health care challenges to focus on in the future. The purpose of the study is to investigate the correlations among nutritional status, assessed by the Body Mass Index, the perception of one's own health status and Life Satisfaction, detected in Italian adolescents living in Tuscany Region, and to investigate the influence of gender on them; Methods: A statistically representative sample of 2760 Tuscan adolescents aged 11, 13 and 15 was involved in the 2018 Health Behaviours at School-aged Children survey. The participants were divided into three nutritional status class: underweight, normal weight and overweight (overweight + obese); Results: The results show that there is a statistically significant difference in all categories between boys and girls aged 13 and 15 years; in girls aged 11 and 13 years, the Life Satisfaction of the overweight group is statistically lower than that of normal and underweight groups; Self-Rated Health is statistically lower in all age groups for overweight individuals compared to normal weight children, except for 11-year-old females; Conclusions: Viewing the psychosocial problems related to overweight, more attention and care must be placed on adolescents to ensure their healthier developmen

    Trend of Correlations between Psychological Symptoms and Socioeconomic Inequalities among Italian Adolescents: Cross-Sectional Study from 2006 to 2018 in Tuscany Region

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    Abstract: Adolescence is a critical moment in life; people become individuals, create new relationships, develop social skills and learn behaviours that they will use for the rest of their lives. During this phase, adolescents establish patterns of behaviour that can protect their health. This study aims to 1. assess the presence of psychological disorders in adolescents of both genders, 2. determine their relation to socio-economic differences based on the Family Affluence Scale (FAS), and 3. assess trends from 2006 to 2018. Data were collected from the Italian Health Behaviour in School-aged Children survey given to a representative sample of Tuscan adolescents aged 11–15 years. Participants (n. 12,550) filled out questionnaires to assess whether psychological symptoms such as feeling low, irritability, nervousness, or sleeping difficulties manifested weekly or more often over the past six months. For the study we utilized a cross-sectional survey method and linear regression to examine the association between psychological symptoms (dependent variable measured on an interval scale (0–16)), gender and FAS. We conducted similar analyses using logistic regressions for each of the four symptoms. An increase in psychological symptoms in both genders was revealed between 2006 and 2018, with a statistically significant presence in females: 0.29 (95% Confidence Interval [CI], 0.17 to 0.41), 1.43 (95% CI, 1.37 to 1.48) and 1.43 (95% CI, 1.34 to 1.52) in low-, medium- and high-affluence families, respectively; whereas males presented 0.14 (95% CI, 0.01 to 0.27), 0.71 (95% CI, 0.65 to 0.77) and 0.31 (95% CI, 0.22 to 0.39), respectively. The probability of a predictive episode of psychological symptoms (feeling low, irritability, nervousness, sleeping difficulties) occurring weekly, or more, often was greatly increased in females of all socioeconomic classes. These findings suggest that the increase in psychological disorders in adolescents should be considered a public health problem and further investigated through longitudinal studies and continuous monitoring of health trends

    Endovascular Aneurysm Repair Using Anaconda Repositionable Aortic Stent Graft Assisted Exclusively by Intravascular Ultrasound Imaging

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    Arteriography with contrast medium (CM) injection is normally employed to visualise the lowest renal artery during endovascular aneurysm repair (EVAR). Intravascular ultrasound (IVUS) has been proposed as an alternative, real-time imaging diagnostic technique to arteriography. In this study, we evaluated the feasibility of EVAR using Anaconda repositionable aortic stent graft (Vascutek) assisted by IVUS (Volcano Visions, Philips) during intraluminal navigation without CM. From January 2016 to December 2017, 25 patients with infrarenal abdominal aortic aneurysms, identified through anatomical inclusion criteria, underwent EVAR. All of the patients had an arteriogram at the end of the EVAR procedure to confirm aortic stent graft patency and to exclude type 1 endoleaks. The primary objective was the technical and clinical success of this CM-free aortic stent graft delivery procedure. At the end of the period, 150 target vessels were evaluated. IVUS versus angio-CT sensitivity and specificity rate were 97.3% and 100%, respectively. The primary technical success was obtained in 88% of the cases. Three patients (12%) needed CM injection to complete the procedure and there were no cases of type 1 endoleak. Primary clinical success was 100%. During follow-up at a mean of 20 months, none of the patients died or had complications. We conclude that a full EVAR procedure is feasible using only IVUS navigation and repositionable aortic stent graft without CM injection in anatomically selected cases
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