387 research outputs found
An Eulerian Approach to the Analysis of Krause's Consensus Models
Abstract. In this paper we analyze a class of multi-agent consensus dynamical systems inspired by Krause’s original model. As in Krause’s, the basic assumption is the so-called bounded confidence: two agents can influence each other only when their state values are below a given distance threshold R. We study the system under an Eulerian point of view considering (possibly continuous) probability distributions of agents and we present original convergence results. The limit distribution is always necessarily a convex combination of delta functions at least R far apart from each other: in other terms these models are locally aggregating. The Eulerian perspective provides the natural framework for designing a numerical algorithm, by which we obtain several simulations in 1 and 2 dimensions
A unifying look at sequence submodularity
Several real-world problems in engineering and applied science require the selection of sequences that maximize a given reward function. Optimizing over sequences as opposed to sets requires exploring an exponentially larger search space and can become prohibitive in most cases of practical interest. However, if the objective function is submodular (intuitively, it exhibits a diminishing return property), the optimization problem becomes more manageable. Recently, there has been increasing interest in sequence submodularity in connection with applications such as recommender systems and online ad allocation. However, mostly ad hoc models and solutions have emerged within these applicative contexts. In consequence, the field appears fragmented and lacks coherence. In this paper, we offer a unified view of sequence submodularity and provide a generalized greedy algorithm that enjoys strong theoretical guarantees. We show how our approach naturally captures several application domains, and our algorithm encompasses existing methods, improving over them. (C) 2021 The Authors. Published by Elsevier B.V
Through the lens of sequence submodularity
Several real-world problems in engineering and applied science require the selection of sequences that maximize a given reward function. Optimizing over sequences as opposed to sets requires exploring an exponentially larger search space and can become prohibitive in most cases of practical interest. However, if the objective function is submodular (intuitively, it exhibits a diminishing return property), the optimization problem becomes more manageable. Recently, there has been increasing interest in sequence submodularity in connection with applications such as recommender systems and online ad allocation. However, mostly ad hoc models and solutions have emerged within these applicative contexts. In consequence, the field appears fragmented and lacks coherence. In this paper, we offer a unified view of sequence submodularity and provide a generalized greedy algorithm that enjoys strong theoretical guarantees. We show how our approach naturally captures several application domains, and our algorithm encompasses existing methods, improving over them
Screening audiologico
Saranno descritti i principali aspetti organizzativi che devono essere affrontati nello screening audiologico di primo, secondo e terzo livello. L\u2019attuale modello di screening \ue8 quello universale, a due stadi. lo screening uditivo neonatale deve essere eseguito dopo le prime 24 ore di vita e prima della dimissione del neonato. il protocollo diagnostico prevede l\u2019anamnesi, l\u2019osservazione ed esame obiettivo che si svolge mediante i test di audiometria comportamentale (BOR, COR/VRA e play audiometry), la valutazione strumentale e la valutazione delle abilita\u2019 comunicative. Saranno poi descritti nuovi test come l\u2019audiometria motoria, il Matrix sentence test per l\u2019ascolto nel rumore e la verifica della protesizzazione nel bambino e il dichotic digit test Rper la valutazione delle riisposte attentive
Modest genetic influence on bronchodilator response: a study in healthy twins.
AIM: To determine the reasons for large standard deviation of bronchodilator response (BDR) and establish whether there is a potential heritable component in healthy subjects. METHODS: 67 monozygotic and 42 dizygotic adult twin pairs were assessed for bronchodilator response (% change in FEV1 after inhaling 400 microg salbutamol). Univariate quantitative genetic modeling was performed. RESULTS: Multiple regression modeling showed a significant association between BDR and sex and baseline FEV1 (P<0.05), while no association was found with smoking habits, body mass index, or age. Within pair correlation in monozygotic twins was modest (0.332), but higher than in dizygotic twins (0.258). Age-, sex-, and baseline FEV1-adjusted genetic effect accounted for 14.9% (95% confidence interval, CI 0%-53.1%) of the variance of BDR, shared environmental effect for 18.4% (95% CI 0%-46.8%), and unshared environmental effect for 66.8% (95% CI 46.8%-88.7%). CONCLUSION: Our twin study showed that individual differences in BDR can be mostly explained by unshared environmental effects. In addition, it is the first study to show low, insignificant hereditary influences, independently from sex, age, and baseline FEV1
Comparative retrospective study on the modalities of biopsying peripheral neuroblastic tumors: a report from the Italian Pediatric Surgical Oncology Group (GICOP)
Background: Peripheral neuroblastic tumors are the most common extracranial solid neoplasms in children. Early and adequate tissue sampling may speed up the diagnostic process and ensure a prompt start of optimal treatment whenever needed. Different biopsy techniques have been described. The purpose of this multi-center study is to evaluate the accuracy and safety of the various examined techniques and to determine whether a preferential procedure exists. Methods: All children who underwent a biopsy, from January 2010 to December 2014, as a result of being diagnosed with a peripheral neuroblastic tumor, were retrospectively reviewed. Data collected included patients’ demographics, clinical presentation, intraoperative technical details, postoperative parameters, complications, and histology reports. The Mann–Whitney U and Fisher's exact tests were used for statistical analysis. Results: The cohort included 100 patients, 32 of whom underwent an incisional biopsy (performed through open or minimally invasive access) (Group A), and the remaining 68 underwent multiple needle-core biopsies (either imaging-guided or laparoscopy/thoracoscopy-assisted) (Group B). Comparing the two groups revealed that Group A patients had a higher rate of complications, a greater need for postoperative analgesia, and required red blood cell transfusion more often. Overall adequacy rate was 94%, without significant differences between the two groups (100% vs. 91.2% for Group A and Group B, respectively, P = 0.0933). Conclusions: Both incision and needle-core biopsying methods provided sub-optimal to optimal sampling adequacy rates in children affected by peripheral neuroblastic tumors. However, the former method was associated with a higher risk of both intraoperative and postoperative complications compared with the latter
“Bad Mum Guilt”: The Representation of ‘Work-Life Balance’ in UK Women’s Magazines
The social policy climate, labour market trends and gendered arrangements for paid and family work mean that ‘work-life balance’ remains a key social issue in the UK. Media representations of ‘work-life balance’ are a key source for the construction of gender and working motherhood. Despite evidence of gendered representations in media coverage of other social issues, little attention has been paid to the construction of work-life balance in UK women's magazines. Articles from the highest circulating UK women's magazines are analysed using a discursive approach to explicate constructions of work-life balance and working motherhood. The analysis reveals that multiple roles are constructed as a problematic choice leading to stress and guilt. Problems associated with multiple roles are constructed as individual problems, in a way that decontextualises and depoliticises them and normalises gendered assumptions and a gendered division of labour. Parallels can be drawn between this and wider discourses about women's daily lives and to the UK social policy context
Epidemiology and natural history of central venous access device use and infusion pump function in the NO16966 trial
Background: Central venous access devices in fluoropyrimidine therapy are associated with complications; however, reliable data are lacking regarding their natural history, associated complications and infusion pump performance in patients with metastatic colorectal cancer.<p></p>
Methods: We assessed device placement, use during treatment, associated clinical outcomes and infusion pump perfomance in the NO16966 trial.<p></p>
Results: Device replacement was more common with FOLFOX-4 (5-fluorouracil (5-FU)+oxaliplatin) than XELOX (capecitabine+oxaliplatin) (14.1% vs 5.1%). Baseline device-associated events and post-baseline removal-/placement-related events occurred more frequently with FOLFOX-4 than XELOX (11.5% vs 2.4% and 8.5% vs 2.1%). Pump malfunctions, primarily infusion accelerations in 16% of patients, occurred within 1.6–4.3% of cycles. Fluoropyrimidine-associated grade 3/4 toxicity was increased in FOLFOX-4-treated patients experiencing a malfunction compared with those who did not (97 out of 155 vs 452 out of 825 patients), predominantly with increased grade 3/4 neutropenia (53.5% vs 39.8%). Febrile neutropenia rates were comparable between patient cohorts±malfunction. Efficacy outcomes were similar in patient cohorts±malfunction.<p></p>
Conclusions: Central venous access device removal or replacement was common and more frequent in patients receiving FOLFOX-4. Pump malfunctions were also common and were associated with increased rates of grade 3/4 haematological adverse events. Oral fluoropyrimidine-based regimens may be preferable to infusional 5-FU based on these findings
Efecto del almacenamiento en frío, el tiempo y la población de especies de Pseudomonas sobre la lipolisis de la leche
The aim of this study was to evaluate the lipolytic index (LI) of Pseudomonas fluorescens and Pseudomonas putida (2, 5, 6 log CFU/mL) in milk during 96 h by the Lipo R method. The strains were isolated from refrigerated raw milk (30 °C, 48 h), and species were confirmed by PCR, inoculated in reconstituted whole milk, and stored at 2 °C, 4 °C, and 8 °C. The storage time (ST) and temperature were associated with LI of P. putida. The interaction among lipolysis, temperature, and ST occurs even with a low population of P. putida and these variables combined together contributed to about 77% of the free fatty acids (FFA) in milk. The ST, temperature, and population of P. fluorescens showed a significant effect on its LI, and the variables contributed to about 43% of FFA. LI was about 224% higher in milk with P. fluorescens than with P. putida. The reduc-tion in ST and milk temperature resulted in a decrease in lipid lysis and a lower index of FFA by P. putida and P. fluorescens, with P. fluorescens showing a higher lipolytic capacity.El objetivo fue evaluar el índice lipolítico (LI) (por el método Lipo R) de Pseudomonas fluorescens y Pseudomonas putidas (2, 5, 6 log CFU / mL) en leche durante 96 h. Las cepas se aislaron de leche cruda refrigerada (30 °C, 48 h), las especies se confirmaron por PCR, se inocularon en leche entera reconsti-tuida y se almacenaron a 2, 4 y 8 °C. El tiempo de almacenamiento (ST) y la temperatura se asociaron con LI de P. putida. La interacción entre lipólisis, temperatura y ST ocurre incluso con una población baja de P. putida y estas variables combinadas contribuyeron a aproximadamente el 77% de los ácidos grasos libres (FFA) en la leche. El ST, la temperatura y la población de P. fluorescens mostraron un efecto significativo en su LI, y las variables contribuyeron a aproximadamente el 43% de FFA. LI fue aproximadamente un 224% mayor en leche con P. fluorescens que con P. putida. La reducción de la temperatura de ST y de la leche dio como resultado una disminución en la lisis lipídica y un índice más bajo de FFA por P. putida y P. fluorescens, esta última mostrando una mayor capacidad lipolítica
Resection of primary tumor in stage 4S neuroblastoma: a second study by the Italian Neuroblastoma Group
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