92 research outputs found
Tower models for power systems transients. A Review
Fast-front transients play an important role in the insulation design of any power system. When a stroke hits the shield wire or the tower of high-voltage overhead power lines, flashover may occur either along the span or across tower insulators, depending on the relevant voltages and insulation strength. As a result, backflashover may take place from the tower structure to the phase conductor whenever a huge impulse current flows along the tower towards considerably high footing impedances. For these reasons, tower modeling for transients studies is an important step in the insulation design, and also for lower voltage applications, where indirect lightning effects may play a predominant role. However, after decades of research on tower modeling, starting from the 1930s with the first model proposed by Jordan, no consensus has been reached neither on a widely accepted tower model nor on the quantitative effect of the tower models on insulation design. Moreover, the fundamental mechanisms at the base of the transient response of towers and the definition of some fundamental parameters have not been totally clarified yet. The aim of this review is to present the available tower models developed through the years in the power community, focussing mainly on lumped/distributed circuit models, and to help the reader to obtain a deeper understanding of them
Genetics, odor perception and food liking: The intriguing role of cinnamon
Humans use a repertoire of > 400 olfactory receptors (ORs) to perceive odorants. The sense of smell is a complex trait whereby genetics and environmental factors interplay. To date, still little is known regarding the genetics of smell, even though the high genetic variability of ORs genes has already been demonstrated. Recently a significant association between cinnamon odorant recognition and the rs317787 polymorphism, located in a cluster of OR genes, has been described. Based on this data, here, we replicated the effect of the same variant (rs317787) on cinnamon odorant identification as well as looked at any possible association with liking for wine whose bouquet frequently smells of cinnamon. Our analysis in a cohort of individuals from two Italian genetic isolates confirmed that rs317787-T allele is associated with an improved cinnamon detection (p-value 5.18
7 10 1206, n = 971) but also with a greater liking for red wine (p-value 0.017, n = 2374). Present results further confirm the association of rs31778 SNP and cinnamon odorants detection and provide additional details about the role of the ORs genes in food liking. Overall, our work contributes to better deciphering the genetic basis of smell and food liking aimed at a more in-depth elucidation of the role of the ORs genes
The Impact of Requirements on Systems Development Speed: A Multiple-Case Study in Automotive
Automotive\ua0manufacturers have historically adopted rigid\ua0requirements\ua0engineering processes. This allowed them to meet safety-critical\ua0requirements\ua0when producing\ua0a\ua0highly complex and differentiated product out of the integration of thousands of physical and software components. Nowadays, few software-related domains are as rapidly changing as the\ua0automotive\ua0industry.\ua0In\ua0particular, the needs of improving\ua0development\ua0speed\ua0are increasingly pushing companies\ua0in\ua0this domain toward new ways of developing software.\ua0In\ua0this paper, we investigate how the goal to increase\ua0development\ua0speed\ua0impacts how\ua0requirements\ua0are managed\ua0in\ua0the\ua0automotive\ua0domain. We start from\ua0a\ua0manager perspective, which we then complement with\ua0a\ua0more general perspective. We used\ua0a\ua0qualitative\ua0multiple-case\ua0study, organized\ua0in\ua0two steps.\ua0In\ua0the first step, we had 20 semi-structured interviews, at two\ua0automotive\ua0manufacturers. Our sampling strategy focuses on manager roles, complemented with technical specialists.\ua0In\ua0the second step, we validated our results with 12 more interviews, covering nine additional respondents and three recurring from the first step.\ua0In\ua0addition to validating our qualitative model, the second step of interviews broadens our perspective with technical experts and change managers. Our respondents indicate and rank six aspects of the current\ua0requirements\ua0engineering approach that\ua0impact\ua0development\ua0speed. These aspects include the negative\ua0impact\ua0of\ua0a\ua0requirements\ua0style dominated by safety concerns as well as decomposition of\ua0requirements\ua0over many levels of abstraction. Furthermore, the use of\ua0requirements\ua0as part of legal contracts with suppliers is seen as hindering fast collaboration. Six additional suggestions for potential improvements include domain-specific tooling, model-based\ua0requirements, test automation, and\ua0a\ua0combination of lightweight upfront\ua0requirements\ua0engineering preceding\ua0development\ua0with precise specifications post-development. Out of these 12 aspects, seven can likely be addressed as part of an ongoing agile transformation. We offer an empirical account of expectations and needs for new\ua0requirements\ua0engineering approaches\ua0in\ua0the\ua0automotive\ua0domain, necessary to coordinate hundreds of collaborating organizations developing software-intensive and potentially safety-critical\ua0systems
Triplet schedule of weekly 5-Fluorouracil and alternating irinotecan or oxaliplatin in advanced colorectal cancer: A dose-finding and phase II study
A weekly administration of alternating irinotecan or oxaliplatin associated to 5-Fluorouracil in advanced colorectal cancer was planned in order to evaluate a new schedule maintaining dose intensities of each drug as in double combinations and tolerability of the triplet association. The following weekly schedule was administered: irinotecan, days 1 and 15; oxaliplatin, days 8 and 22; 5-fluorouracil (5-FU) over 12-h (from 10:00 p.m. to 10:00 a.m.) timed flat infusion, days 1-2, 8-9, 15-16 and 22-23, every 4 weeks. Dosefinding and phase II study were planned. Thirteen patients were enrolled in the dose-finding study and 23 in the phase II study. The recommended doses of our study are: irinotecan 160 mg/m2; oxaliplatin 80 mg/m2; 5-FU 900 mg/m2. The doselimiting toxicity was diarrhea (35% of patients) but no cases of febrile neutropenia were observed. In 30 patients assessable for response two complete (6.7%) and 18 partial (60%) responses were observed, for an overall response rate of 66.7% (α0.05, CI±7). The triplet association using this weekly alternating schedule is an active and well-tolerated outpatient regimen. Surgical removal of residual disease was considered in 5 patients and a radical resection was performed in 5 patients (14%)
Application-Layer Connector Synthesis
International audienceThe heterogeneity characterizing the systems populating the Ubiquitous Computing environment prevents their seamless interoperability. Heterogeneous protocols may be willing to cooperate in order to reach some common goal even though they meet dynamically and do not have a priori knowledge of each other. Despite numerous e orts have been done in the literature, the automated and run-time interoperability is still an open challenge for such environment. We consider interoperability as the ability for two Networked Systems (NSs) to communicate and correctly coordinate to achieve their goal(s). In this chapter we report the main outcomes of our past and recent research on automatically achieving protocol interoperability via connector synthesis. We consider application-layer connectors by referring to two conceptually distinct notions of connector: coordinator and mediator. The former is used when the NSs to be connected are already able to communicate but they need to be speci cally coordinated in order to reach their goal(s). The latter goes a step forward representing a solution for both achieving correct coordination and enabling communication between highly heterogeneous NSs. In the past, most of the works in the literature described e orts to the automatic synthesis of coordinators while, in recent years the focus moved also to the automatic synthesis of mediators. Within the Connect project, by considering our past experience on automatic coordinator synthesis as a baseline, we propose a formal theory of mediators and a related method for automatically eliciting a way for the protocols to interoperate. The solution we propose is the automated synthesis of emerging mediating connectors (i.e., mediators for short)
Klinefelter syndrome: cardiovascular abnormalities and metabolic disorders
Klinefelter syndrome (KS) is one of the most common genetic causes of male infertility. This condition is associated with much comorbidity and with a lower life expectancy. The aim of this review is to explore more in depth cardiovascular and metabolic disorders associated to KS. KS patients have an increased risk of cerebrovascular disease (standardized mortality ratio, SMR, 2.2; 95% confidence interval, CI, 1.6–3.0), but it is not clear whether the cause of the death is of thrombotic or hemorrhagic nature. Cardiovascular congenital anomalies (SMR, 7.3; 95% CI, 2.4–17.1) and the development of thrombosis or leg ulcers (SMR, 7.9; 95% CI, 2.9–17.2) are also more frequent in these subjects. Moreover, cardiovascular abnormalities may be at least partially reversed by testosterone replacement therapy (TRT). KS patients have also an increased probability of endocrine and/or metabolic disease, especially obesity, metabolic syndrome and type 2 diabetes mellitus. The effects of TRT on these abnormalities are not entirely clear
Genetic analyses of the electrocardiographic QT interval and its components identify additional loci and pathways
The QT interval is an electrocardiographic measure representing the sum of ventricular depolarization and repolarization, estimated by QRS duration and JT interval, respectively. QT interval abnormalities are associated with potentially fatal ventricular arrhythmia. Using genome-wide multi-ancestry analyses (>250,000 individuals) we identify 177, 156 and 121 independent loci for QT, JT and QRS, respectively, including a male-specific X-chromosome locus. Using gene-based rare-variant methods, we identify associations with Mendelian disease genes. Enrichments are observed in established pathways for QT and JT, and previously unreported genes indicated in insulin-receptor signalling and cardiac energy metabolism. In contrast for QRS, connective tissue components and processes for cell growth and extracellular matrix interactions are significantly enriched. We demonstrate polygenic risk score associations with atrial fibrillation, conduction disease and sudden cardiac death. Prioritization of druggable genes highlight potential therapeutic targets for arrhythmia. Together, these results substantially advance our understanding of the genetic architecture of ventricular depolarization and repolarization
Genetic analyses of the electrocardiographic QT interval and its components identify additional loci and pathways.
The QT interval is an electrocardiographic measure representing the sum of ventricular depolarization and repolarization, estimated by QRS duration and JT interval, respectively. QT interval abnormalities are associated with potentially fatal ventricular arrhythmia. Using genome-wide multi-ancestry analyses (>250,000 individuals) we identify 177, 156 and 121 independent loci for QT, JT and QRS, respectively, including a male-specific X-chromosome locus. Using gene-based rare-variant methods, we identify associations with Mendelian disease genes. Enrichments are observed in established pathways for QT and JT, and previously unreported genes indicated in insulin-receptor signalling and cardiac energy metabolism. In contrast for QRS, connective tissue components and processes for cell growth and extracellular matrix interactions are significantly enriched. We demonstrate polygenic risk score associations with atrial fibrillation, conduction disease and sudden cardiac death. Prioritization of druggable genes highlight potential therapeutic targets for arrhythmia. Together, these results substantially advance our understanding of the genetic architecture of ventricular depolarization and repolarization
Radiations and male fertility
During recent years, an increasing percentage of male infertility has to be attributed to an array of environmental,
health and lifestyle factors. Male infertility is likely to be affected by the intense exposure to heat and extreme
exposure to pesticides, radiations, radioactivity and other hazardous substances. We are surrounded by several types
of ionizing and non-ionizing radiations and both have recognized causative effects on spermatogenesis. Since it is
impossible to cover all types of radiation sources and their biological effects under a single title, this review is
focusing on radiation deriving from cell phones, laptops, Wi-Fi and microwave ovens, as these are the most
common sources of non-ionizing radiations, which may contribute to the cause of infertility by exploring the effect
of exposure to radiofrequency radiations on the male fertility pattern. From currently available studies it is clear that
radiofrequency electromagnetic fields (RF-EMF) have deleterious effects on sperm parameters (like sperm count,
morphology, motility), affects the role of kinases in cellular metabolism and the endocrine system, and produces
genotoxicity, genomic instability and oxidative stress. This is followed with protective measures for these radiations
and future recommendations. The study concludes that the RF-EMF may induce oxidative stress with an increased
level of reactive oxygen species, which may lead to infertility. This has been concluded based on available
evidences from in vitro and in vivo studies suggesting that RF-EMF exposure negatively affects sperm quality
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