System designs for bulk and user-generated content delivery in the internet

This thesis proposes and evaluates new system designs to support two emerging Internet workloads: (a) bulk content, such as downloads of large media and scientific libraries, and (b) user-generated content (UGC), such as photos and videos that users share online, typically on online social networks (OSNs). Bulk content accounts for a large and growing fraction of today\u27s Internet traffic. Due to the high cost of bandwidth, delivering bulk content in the Internet is expensive. To reduce the cost of bulk transfers, I proposed traffic shaping and scheduling designs that exploit the delay-tolerant nature of bulk transfers to allow ISPs to deliver bulk content opportunistically. I evaluated my proposals through software prototypes and simulations driven by real-world traces from commercial and academic ISPs and found that they result in considerable reductions in transit costs or increased link utilization. The amount of user-generated content (UGC) that people share online has been rapidly growing in the past few years. Most users share UGC using online social networking websites (OSNs), which can impose arbitrary terms of use, privacy policies, and limitations on the content shared on their websites. To solve this problem, I evaluated the feasibility of a system that allows users to share UGC directly from the home, thus enabling them to regain control of the content that they share online. Using data from popular OSN websites and a testbed deployed in 10 households, I showed that current trends bode well for the delivery of personal UGC from users\u27 homes. I also designed and deployed Stratus, a prototype system that uses home gateways to share UGC directly from the home.Schwerpunkt dieser Doktorarbeit ist der Entwurf und die Auswertung neuer Systeme zur Unterstützung von zwei entstehenden Internet-Workloads: (a) Bulk-Content, wie zum Beispiel die Übertragung von großen Mediendateien und wissenschaftlichen Datenbanken, und (b) nutzergenerierten Inhalten, wie zum Beispiel Fotos und Videos, die Benutzer üblicherweise in sozialen Netzwerken veröffentlichen. Bulk-Content macht einen großen und weiter zunehmenden Anteil im heutigen Internetverkehr aus. Wegen der hohen Bandbreitenkosten ist die Übertragung von Bulk-Content im Internet jedoch teuer. Um diese Kosten zu senken habe ich neue Scheduling- und Traffic-Shaping-Lösungen entwickelt, die die Verzögerungsresistenz des Bulk-Verkehrs ausnutzen und es ISPs ermöglichen, Bulk-Content opportunistisch zu übermitteln. Durch Software-Prototypen und Simulationen mit Daten aus dem gewerblichen und akademischen Internet habe ich meine Lösungen ausgewertet und herausgefunden, dass sich die Übertragungskosten dadurch erheblich senken lassen und die Ausnutzung der Netze verbessern lässt. Der Anteil an nutzergenerierten Inhalten (user-generated content, UGC), die im Internet veröffentlicht wird, hat in den letzen Jahren ebenfalls schnell zugenommen. Meistens wird UGC in sozialen Netzwerken (online social networks, OSN) veröffentlicht. Dadurch sind Benutzer den willkürlichen Nutzungsbedingungen, Datenschutzrichtlinien, und Einschränkungen des OSN-Providers unterworfen. Um dieses Problem zu lösen, habe ich die Machbarkeit eines Systems ausgewertet, anhand dessen Benutzer UGC direkt von zu Hause veröffentlichen und die Kontrolle über ihren UGC zurückgewinnen können. Meine Auswertung durch Daten aus zwei populären OSN-Websites und einem Feldversuch in 10 Haushalten deutet darauf hin, dass angesichts der Fortschritte in der Bandbreite der Zugangsnetze die Veröffentlichung von persönlichem UGC von zu Hause in der nahen Zukunft möglich sein könnte.Schließlich habe ich Stratus entworfen und entwickelt, ein System, das auf Home-Gateways basiert und mit dem Benutzer UGC direkt von zu Hause veröffentlichen können

The Coexistence of asthma and Chronic Ostructive Pulmonary Disease (COPD): prevalence and risk factors in young, middle-aged and elderly people from the general population

Background: The joint distribution of asthma and chronic obstructive pulmonary disease (COPD) has not been well described. This study aims at determining the prevalence of self-reported physician diagnoses of asthma, COPD and of the asthma-COPD overlap syndrome and to assess whether these conditions share a common set of risk factors. Methods: A screening questionnaire on respiratory symptoms, diagnoses and risk factors was administered by mail or phone to random samples of the general Italian population aged 20–44 (n = 5163) 45–64 (n = 2167) and 65–84 (n = 1030) in the frame of the multicentre Gene Environment Interactions in Respiratory Diseases (GEIRD) study. Results: A physician diagnosis of asthma or COPD (emphysema/chronic bronchitis/COPD) was reported by 13% and 21% of subjects aged &lt;65 and 65–84 years respectively. Aging was associated with a marked decrease in the prevalence of diagnosed asthma (from 8.2% to 1.6%) and with a marked increase in the prevalence of diagnosed COPD (from 3.3% to 13.3%). The prevalence of the overlap of asthma and COPD was 1.6% (1.3%–2.0%), 2.1% (1.5%–2.8%) and 4.5% (3.2%–5.9%) in the 20–44, 45–64 and 65–84 age groups. Subjects with both asthma and COPD diagnoses were more likely to have respiratory symptoms, physical impairment, and to report hospital admissions compared to asthma or COPD alone (p&lt;0.01). Age, sex, education and smoking showed different and sometimes opposite associations with the three conditions. Conclusion: Asthma and COPD are common in the general population, and they coexist in a substantial proportion of subjects. The asthma-COPD overlap syndrome represents an important clinical phenotype that deserves more medical attention and further research.</br

Do I need training in public health ethics? A survey on Italian residents' beliefs, knowledge and curricula.

Introduction: Ethics is needed to support the decision-making process in public health and to face moral issues during practice. However, professionals are often not adequately trained.Objectives: In 2015, the National Conference of Public Health Medical Residents of the Italian Society of Public Health started the ‘Public Health Ethics’ workgroup to evaluate how the Italian Schools of Public Health train their residents in ethics, and which are residents’ beliefs, knowledge and attitudes about public health ethics. Methods: A survey was built and emailed to the Italian public health residents.Results: Residents are interested in ethics/bioethics (83.2%) and are aware of its importance for professional practice (97.2%). However, few of them (19.6%) evaluated their competence above a satisfactory level. They believe that a training in ethics should be offered during residency (92.1%). Nonetheless, in Italy only two schools required a course on bioethics, and one a course in public health ethics. According to residents, a public health ethics trainer should be a public health professional (23.2%) or a social scientist (22.8%).Conclusions: In Italy, Schools of Public Health do not train future professionals in ethics or public health ethics during residency. Training should be implemented in curricula, and trainers should have a strong competence in both public health and ethics

Latitude variation in the prevalence of asthma and allergic rhinitis in Italy: results from the GEIRD study

BACKGROUND: Earlier studies have pointed out a great variability in the prevalence of asthma and asthma-like symptoms in different geo-climatic areas. AIM: To test the association between latitude and prevalence of asthma and allergic rhinitis in Italian young adults. METHODS: In the frame of Gene-Environment Interaction in Respiratory Diseases study, a postal screening questionnaire on respiratory health and exposure to environmental factors was administered to 18,357 randomly selected subjects aged 20-44 years in 7 centres: 3 in Northern (Torino, Pavia, Verona), 2 in Central (Ancona, Perugia) and 2 in Southern Italy (Salerno, Sassari). RESULTS: 10,494 (57.2%) subjects responded to the questionnaire. The prevalence of self-reported doctor-diagnosed asthma and allergic rhinitis in the lifespan was 10.2% and 26.9%, respectively, and was significantly different across the centres (p&lt;0.05). After adjusting for sex, age, potential risk factors for respiratory diseases and design confounders, the prevalence of asthma (OR: 1.07 per 1°latitude decrease, p&lt;0.001), asthma-like symptoms (wheezing, chest tightness, asthma attacks: OR ranging from 1.04 to 1.06, p&lt;0.05) and allergic rhinitis (OR: 1.03, p=0.04) showed a significant north-to-south trend. Similarly, a 1°C increment in temperature was significantly associated with asthma (OR: 1.10, p&lt;0.001) and asthma-like symptoms (OR from 1.07 to 1.10, p&lt;0.05), but not with allergic rhinitis (OR=1.02, p=0.190). CONCLUSION: The prevalence of asthma and allergic rhinitis increased moving southwards in Italy, suggesting that prolonged exposure to different geo-climatic conditions may affect the onset of asthma and allergic respiratory diseases

Association of Urinary and Plasma Levels of Trimethylamine N-Oxide (TMAO) with Foods

Introduction: Trimethylamine N-oxide (TMAO) may play a key mediator role in the relationship between the diet, gut microbiota and cardiovascular diseases, particularly in people with kidney failure. The aim of this review is to evaluate which foods have a greater influence on blood or urinary trimethylamine N-oxide (TMAO) levels. Methods: 391 language articles were screened, and 27 were analysed and summarized for this review, using the keywords "TMAO" AND "egg" OR "meat" OR "fish" OR "dairy" OR "vegetables" OR "fruit" OR "food" in December 2020. Results: A strong correlation between TMAO and fish consumption, mainly saltwater fish and shellfish, but not freshwater fish, has been demonstrated. Associations of the consumption of eggs, dairy and meat with TMAO are less clear and may depend on other factors such as microbiota or cooking methods. Plant-based foods do not seem to influence TMAO but have been less investigated. Discussion: Consumption of saltwater fish, dark meat fish and shellfish seems to be associated with an increase in urine or plasma TMAO values. Further studies are needed to understand the relationship between increased risk of cardiovascular disease and plasma levels of TMAO due to fish consumption. Interventions coupled with long-term dietary patterns targeting the gut microbiota seem promising

Exploiting natural polysaccharides to enhance in vitro bio-constructs of primary neurons and progenitor cells

Current strategies in Central Nervous System (CNS) repair focus on the engineering of artificial scaffolds for guiding and promoting neuronal tissue regrowth. Ideally, one should combine such synthetic structures with stem cell therapies, encapsulating progenitor cells and instructing their differentiation and growth. We used developments in the design, synthesis, and characterization of polysaccharide-based bioactive polymeric materials for testing the ideal composite supporting neuronal network growth, synapse formation and stem cell differentiation into neurons and motor neurons. Moreover, we investigated the feasibility of combining these approaches with engineered mesenchymal stem cells able to release neurotrophic factors. We show here that composite bio-constructs made of Chitlac, a Chitosan derivative, favor hippocampal neuronal growth, synapse formation and the differentiation of progenitors into the proper neuronal lineage, that can be improved by local and continuous delivery of neurotrophins. Statement of Significance In our work, we characterized polysaccharide-based bioactive platforms as biocompatible materials for nerve tissue engineering. We show that Chitlac-thick substrates are able to promote neuronal growth, differentiation, maturation and formation of active synapses. These observations support this new material as a promising candidate for the development of complex bio-constructs promoting central nervous system regeneration. Our novel findings sustain the exploitation of polysaccharide-based scaffolds able to favour neuronal network reconstruction. Our study shows that Chitlac-thick may be an ideal candidate for the design of biomaterial scaffolds enriched with stem cell therapies as an innovative approach for central nervous system repair

Two naphthalene degrading bacteria belonging to the genera Paenibacillus and Pseudomonas isolated from a highly polluted lagoon perform different sensitivities to the organic and heavy metal contaminants

Two bacterial strains were isolated in the presence of naphthalene as the sole carbon and energy source from sediments of the Orbetello Lagoon, Italy, which is highly contaminated with both organic compounds and metals. 16S rRNA gene sequence analysis of the two isolates assigned the strains to the genera Paenibacillus and Pseudomonas. The effect of different contaminants on the growth behaviors of the two strains was investigated. Pseudomonas sp. ORNaP2 showed a higher tolerance to benzene, toluene, and ethylbenzene than Paenibacillus sp. ORNaP1. In addition, the toxicity of heavy metals potentially present as co-pollutants in the investigated site was tested. Here, strain Paenibacillus sp. ORNaP1 showed a higher tolerance towards arsenic, cadmium, and lead, whereas it was far more sensitive towards mercury than strain Pseudomonas sp. ORNaP2. These differences between the Gram-negative Pseudomonas and the Gram-positive Paenibacillus strain can be explained by different general adaptive response systems present in the two bacteria

Neue Systeme zur Unterstützung von Bulk-Content und nutzergenerierten Inhalten

This thesis proposes and evaluates new system designs to support two emerging Internet workloads: (a) bulk content, such as downloads of large media and scientific libraries, and (b) user-generated content (UGC), such as photos and videos that users share online, typically on online social networks (OSNs). Bulk content accounts for a large and growing fraction of today's Internet traffic. Due to the high cost of bandwidth, delivering bulk content in the Internet is expensive. To reduce the cost of bulk transfers, I proposed traffic shaping and scheduling designs that exploit the delay-tolerant nature of bulk transfers to allow ISPs to deliver bulk content opportunistically. I evaluated my proposals through software prototypes and simulations driven by real-world traces from commercial and academic ISPs and found that they result in considerable reductions in transit costs or increased link utilization. The amount of user-generated content (UGC) that people share online has been rapidly growing in the past few years. Most users share UGC using online social networking websites (OSNs), which can impose arbitrary terms of use, privacy policies, and limitations on the content shared on their websites. To solve this problem, I evaluated the feasibility of a system that allows users to share UGC directly from the home, thus enabling them to regain control of the content that they share online. Using data from popular OSN websites and a testbed deployed in 10 households, I showed that current trends bode well for the delivery of personal UGC from users' homes. I also designed and deployed Stratus, a prototype system that uses home gateways to share UGC directly from the home.Schwerpunkt dieser Doktorarbeit ist der Entwurf und die Auswertung neuer Systeme zur Unterstützung von zwei entstehenden Internet-Workloads: (a) Bulk-Content, wie zum Beispiel die Übertragung von großen Mediendateien und wissenschaftlichen Datenbanken, und (b) nutzergenerierten Inhalten, wie zum Beispiel Fotos und Videos, die Benutzer üblicherweise in sozialen Netzwerken veröffentlichen. Bulk-Content macht einen großen und weiter zunehmenden Anteil im heutigen Internetverkehr aus. Wegen der hohen Bandbreitenkosten ist die Übertragung von Bulk-Content im Internet jedoch teuer. Um diese Kosten zu senken habe ich neue Scheduling- und Traffic-Shaping-Lösungen entwickelt, die die Verzögerungsresistenz des Bulk-Verkehrs ausnutzen und es ISPs ermöglichen, Bulk-Content opportunistisch zu übermitteln. Durch Software-Prototypen und Simulationen mit Daten aus dem gewerblichen und akademischen Internet habe ich meine Lösungen ausgewertet und herausgefunden, dass sich die Übertragungskosten dadurch erheblich senken lassen und die Ausnutzung der Netze verbessern lässt. Der Anteil an nutzergenerierten Inhalten (user-generated content, UGC), die im Internet veröffentlicht wird, hat in den letzen Jahren ebenfalls schnell zugenommen. Meistens wird UGC in sozialen Netzwerken (online social networks, OSN) veröffentlicht. Dadurch sind Benutzer den willkürlichen Nutzungsbedingungen, Datenschutzrichtlinien, und Einschränkungen des OSN-Providers unterworfen. Um dieses Problem zu lösen, habe ich die Machbarkeit eines Systems ausgewertet, anhand dessen Benutzer UGC direkt von zu Hause veröffentlichen und die Kontrolle über ihren UGC zurückgewinnen können. Meine Auswertung durch Daten aus zwei populären OSN-Websites und einem Feldversuch in 10 Haushalten deutet darauf hin, dass angesichts der Fortschritte in der Bandbreite der Zugangsnetze die Veröffentlichung von persönlichem UGC von zu Hause in der nahen Zukunft möglich sein könnte.Schließlich habe ich Stratus entworfen und entwickelt, ein System, das auf Home-Gateways basiert und mit dem Benutzer UGC direkt von zu Hause veröffentlichen können