Topological features of massive bosons on two dimensional Einstein space-time

In this paper we tackle the problem of constructing explicit examples of topological cocycles of Roberts' net cohomology, as defined abstractly by Brunetti and Ruzzi. We consider the simple case of massive bosonic quantum field theory on the two dimensional Einstein cylinder. After deriving some crucial results of the algebraic framework of quantization, we address the problem of the construction of the topological cocycles. All constructed cocycles lead to unitarily equivalent representations of the fundamental group of the circle (seen as a diffeomorphic image of all possible Cauchy surfaces). The construction is carried out using only Cauchy data and related net of local algebras on the circle.Comment: 41 pages, title changed, minor changes, typos corrected, references added. Accepted for publication in Ann. Henri Poincare

Morelli-W\l odarczyk cobordism and examples of rooftop flips

We introduce the notion of rooftop flip, namely a small modification among normal projective varieties which is modeled by a smooth projective variety of Picard number 2 admitting two projective bundle structures. Examples include the Atiyah flop and the Mukai flop, modeled respectively by $\mathbb{P}^1\times \mathbb{P}^1$ and by $\mathbb{P}\left(T_{\mathbb{P}^2}\right)$. Using the Morelli-Wlodarczyk cobordism, we prove that any smooth projective variety of Picard number 1, endowed with a $\mathbb{C}^*$-action with only two fixed point components, induces a rooftop flip.Comment: 15 pages, 2 figures. Comments are very welcome

Statistical Process Control techniques to monitor quality determinants in digital Voice-of-Customer

Purpose - Digital Voice-of-Customer (digital VoC) primarily consists of textual feedback posted by users of products or services on the web. Digital VoC may represent a valuable source of information for quality management, and its promising potential is also receiving a lot of attention in the new Quality 4.0 framework. However, manufacturers and service providers still lack operative approaches to fully exploit the value of digital VoC. This study tries to answer the following research question: How Statistical Process Control (SPC) techniques can be used to monitor digital VoC over time? Design/methodology/approach - This article explores the applicability of SPC to support digital VoC analysis. Two types of control charts, for variables and attributes, were applied to a real case study concerning a product-service system (car-sharing). Findings - SPC tools may represent an interesting alternative to traditional quality tracking approaches to analyze the evolution of quality determinants over time. Originality/value – This study shows how Artificial intelligence algorithms and SPC tools may support product and service designers in implementing continuous improvement actions by analyzing digital VoC over time

Study on the Probability Distribution of Pitting for Naturally Corroded Prestressing Strands Accounting for Surface Defects

One of the most urgent scientific needs from a technical and economic engineering point of view is the assessment of concrete structures suffering corrosion deterioration. However, the pursuit of this target in the case of corroded prestressed concrete (PC) members is hindered by the lack of (i) consolidated simplified formulations to be used in the engineering daily practice and (ii) works investigating the uncertainties in the correlation between the damage induced by corrosion and the structural resistance. To this aim, the present study adopts a 3D-scanning technique for the pitting morphology evaluation of several corroded prestressing strands retrieved from 10-year-old PC beams. First, the probabilistic distributions of penetration depths have been investigated. Second, the pitting factors alpha and omega(i) have been proposed and discussed to quantify the level of corrosion in longitudinal and transversal direction, respectively. Finally, correlations have been derived between the maximum and average penetration depth as a function of the level of corrosion and the surface defects mapping has been carried out on the corroded PC beams. The results show that the penetration depth of strands subjected to chloride-induced corrosion can be best fitted by a lognormal distribution function. Additionally, the simultaneous consideration of longitudinal and transversal pitting factor is found out to be essential for an exhaustive comprehension of pitting corrosion. Moreover, the outcomes highlight that the presence of longitudinal splitting cracks plays a fundamental role in the corrosion spatial variability of prestressing strands

Cascaded neural networks improving fish species prediction accuracy: the role of the biotic information

Species distribution is the result of complex interactions that involve environmental parameters as well as biotic factors. However, methodological approaches that consider the use of biotic variables during the prediction process are still largely lacking. Here, a cascaded Artifcial Neural Networks (ANN) approach is proposed in order to increase the accuracy of fsh species occurrence estimates and a case study for Leucos aulain NE Italy is presented as a demonstration case. Potentially useful biotic information (i.e. occurrence of other species) was selected by means of tetrachoric correlation analysis and on the basis of the improvements it allowed to obtain relative to models based on environmental variables only. The prediction accuracy of the L. aulamodel based on environmental variables only was improved by the addition of occurrence data for A. arborellaand S. erythrophthalmus. While biotic information was needed to train the ANNs, the fnal cascaded ANN model was able to predict L. aula better than a conventional ANN using environmental variables only as inputs. Results highlighted that biotic information provided by occurrence estimates for non-target species whose distribution can be more easily and accurately modeled may play a very useful role, providing additional predictive variables to target species distribution models

Acute anterior myocardial infarction: Streptokinase prevents ventricular thrombosis independently of its effect on infarct size

Left ventricular thrombosis (LVT) is a frequent complication after acute anterior myocardial infarction (AMI). The purpose of this study is to evaluate whether streptokinase (SK) therapy prevents LVT, and whether this effect is due to the preservation of left ventricular function or to the fibrinolytic action of the drug. Sixty-five patients who underwent a left ventricular angiography within 2 months after a first AMI were studied. Twenty-eight patients (SK group) received SK 1,500,000 U i.v. administered over 60 min within 6 h from the onset of symptoms. A lower incidence of LVT was found in the SK group (p = 0.0003). We divided patients into two classes according to the value of akinetic-dyskinetic area (AD): the first group with a lower value of AD, the second group with a higher value of AD. In both groups, a reduced incidence of LVT was associated with SK therapy (p = 0.014, p = 0.015, respectively). Early infusion of SK during AMI seems to prevent the development of LVT, with an effect partly independent from its action on infarct size for small to large myocardial infarction

Results obtained with level II oncoplastic surgery spanning 20 years of breast cancer treatment: Do we really need further demonstration of reliability?

Oncoplastic surgery (OPS) has demonstrated its superiority above traditional breast conserving surgery, but is still struggling to consolidate its role in breast cancer therapeutic protocols mainly because of contrasting scientific evidences and reduced follow-up results available. The objective of our contribution is to analyze results obtained with 381 patients consecutively treated in our Multidisciplinary Breast Center by means of level II OPS between January 1998 and January 2018 for unilateral, primary breast cancer. Surgical endpoints were mean specimen weight and volume, mean diameter of main lesion (MLD), rates of positive margins (PMR), re-excision (RR), conversion to mastectomy (CMR), complications (CR) and oncological endpoints as overall survival (OS), disease-free survival (DFS), and local recurrence rate (LR). About 29.1% were treated for multifocal/multicentric disease, and 29.1% previously underwent neo-adjuvant chemotherapy (NACT). Regarding surgical techniques, 53.0% of patients received "inverted T" and 30.1% "J" mammoplasties, whereas 13.6% underwent "round block," 2.3% "Grisotti," and 1% "batwing" techniques. Regarding surgical outcomes, mean specimen weight was 215 g (50-2157) and volume 345 mm3 (21-7980). MLD 23 mm, PMR 7.6%, RR 3.6%, CMR 1.6%, and CR 5.8%. With a mean follow-up of 118 months, oncological outcomes were: OS 93.7%, DFS 82.3%, LR 4.4%. In conclusion, our analysis confirmed level II OPS reliability even for longer follow-up timing and in difficult situations as multifocal disease or after NACT