Accuracy of Author Names in Bibliographic Data Sources: An Italian Case Study

We investigate the accuracy of how author names are reported in bibliographic records excerpted from four prominent sources: WoS, Scopus, PubMed, and CrossRef. We take as a case study 44,549 publications stored in the internal database of Sapienza University of Rome, one of the largest universities in Europe. While our results indicate generally good accuracy for all bibliographic data sources considered, we highlight a number of issues that undermine the accuracy for certain classes of author names, including compound names and names with diacritics, which are common features to Italian and other Western languages

Max flow vitality in general and stst-planar graphs

The \emph{vitality} of an arc/node of a graph with respect to the maximum flow between two fixed nodes $s$ and $t$ is defined as the reduction of the maximum flow caused by the removal of that arc/node. In this paper we address the issue of determining the vitality of arcs and/or nodes for the maximum flow problem. We show how to compute the vitality of all arcs in a general undirected graph by solving only $2(n-1)$ max flow instances and, In $st$-planar graphs (directed or undirected) we show how to compute the vitality of all arcs and all nodes in $O(n)$ worst-case time. Moreover, after determining the vitality of arcs and/or nodes, and given a planar embedding of the graph, we can determine the vitality of a `contiguous' set of arcs/nodes in time proportional to the size of the set.Comment: 12 pages, 3 figure

Computing the shapley value in allocation problems: Approximations and bounds, with an application to the Italian VQR research assessment program

In allocation problems, a given set of goods are assigned to agents in such a way that the social welfare is maximized, that is, the largest possible global worth is achieved. When goods are indivisible, it is possible to use money compensation to perform a fair allocation taking into account the actual contribution of all agents to the social welfare. Coalitional games provide a formal mathematical framework to model such problems, in particular the Shapley value is a solution concept widely used for assigning worths to agents in a fair way. Unfortunately, computing this value is a #P-hard problem, so that applying this good theoretical notion is often quite difficult in real-world problems. In this paper, we first review the application of the Shapley value to an allocation problem that models the evaluation of the Italian research structures with a procedure known as VQR. For large universities, the problem involves thousands of agents and goods (here, researchers and their research products). We then describe some useful properties that allow us to greatly simplify many such large instances. Moreover, we propose new algorithms for computing lower bounds and upper bounds of the Shapley value, which in some cases provide the exact result and that can be combined with approximation algorithms. The proposed techniques have been tested on large real-world instances of the VQR research evaluation problem

Computing the Shapley value in allocation problems: approximations and bounds, with an application to the Italian VQR research assessment program

In allocation problems, a given set of goods are assigned to agents in such a way that the social welfare is maximised, that is, the largest possible global worth is achieved. When goods are indivisible, it is possible to use money compensation to perform a fair allocation taking into account the actual contribution of all agents to the social welfare. Coalitional games provide a formal mathematical framework to model such problems, in particular the Shapley value is a solution concept widely used for assigning worths to agents in a fair way. Unfortunately, computing this value is a #P-hard problem, so that applying this good theoretical notion is often quite difficult in real-world problems. We describe useful properties that allow us to greatly simplify the instances of allocation problems, without affecting the Shapley value of any player. Moreover, we propose algorithms for computing lower bounds and upper bounds of the Shapley value, which in some cases provide the exact result and that can be combined with approximation algorithms. The proposed techniques have been implemented and tested on a real-world application of allocation problems, namely, the Italian research assessment program known as VQR (Verifica della Qualità della Ricerca, or Research Quality Assessment)1. For the large university considered in the experiments, the problem involves thousands of agents and goods (here, researchers and their research products). The algorithms described in the paper are able to compute the Shapley value for most of those agents, and to get a good approximation of the Shapley value for all of the

On the Shapley value and its application to the Italian VQR research assessment exercise

Research assessment exercises have now become common evaluation tools in a number of countries. These exercises have the goal of guiding merit-based public funds allocation, stimulating improvement of research productivity through competition and assessing the impact of adopted research support policies. One case in point is Italy's most recent research assessment effort, VQR 2011–2014 (Research Quality Evaluation), which, in addition to research institutions, also evaluated university departments, and individuals in some cases (i.e., recently hired research staff and members of PhD committees). However, the way an institution's score was divided, according to VQR rules, between its constituent departments or its staff members does not enjoy many desirable properties well known from coalitional game theory (e.g., budget balance, fairness, marginality). We propose, instead, an alternative score division rule that is based on the notion of Shapley value, a well known solution concept in coalitional game theory, which enjoys the desirable properties mentioned above. For a significant test case (namely, Sapienza University of Rome, the largest university in Italy), we present a detailed comparison of the scores obtained, for substructures and individuals, by applying the official VQR rules, with those resulting from Shapley value computations. We show that there are significant differences in the resulting scores, making room for improvements in the allocation rules used in research assessment exercises

Max-flow vitality in undirected unweighted planar graphs

We show a fast algorithm for determining the set of relevant edges in a planar undirected unweighted graph with respect to the maximum flow. This is a special case of the \emph{max flow vitality} problem, that has been efficiently solved for general undirected graphs and $st$-planar graphs. The \emph{vitality} of an edge of a graph with respect to the maximum flow between two fixed vertices $s$ and $t$ is defined as the reduction of the maximum flow caused by the removal of that edge. In this paper we show that the set of edges having vitality greater than zero in a planar undirected unweighted graph with $n$ vertices, can be found in $O(n \log n)$ worst-case time and $O(n)$ space.Comment: 9 pages, 4 figure

322 Atrial morphological and functional parameters in hypertrophic cardiomyopathy: cardiovascular outcome implication

Abstract Aims The impact of atrial function measured by standard and advanced echocardiographic techniques is emerging in various clinical settings but remains poorly explored in patients with hypertrophic cardiomyopathy (HCM). Methods and results Consecutive patients with HCM referred to the heart failure outpatient clinic were prospectively enrolled. Complete clinical and echocardiographic evaluation was performed, including fully automated 2D speckle tracking analysis software (AutoStrain, TomTec). Atrial function was assessed by means of left atrial (LA) volume, LA diameter, a'-TDI, and global peak atrial longitudinal strain (PALS). The primary endpoint was a composite of cardiovascular (CV) events (cardiovascular death or hospitalization, new-onset atrial fibrillation, surgical myectomy, sustained ventricular tachycardia or ventricular fibrillation) during the follow-up. A total of 40 patients with confirmed HCM diagnoses and complete follow-up were included, mean age was 61 ± 14 years, 62% male, ejection fraction 64 ± 8%. LA was frequently enlarged (indexed LA volume 43 ± 14 ml/m2, LA diameter 39 ± 7 mm), and dysfunctional (a'-TDI 7.1 ± 2.2 cm/s, PALS 21 ± 7%). During a mean follow-up of 460 ± 300 days, seven patients had a CV event. Among LA parameters, septal a'-TDI seems to characterize patients with events the most (5.5 ± 2.1 vs. 7.5 ± 2.3, P = 0.03). This was confirmed in an age-adjusted survival model [HR: 0.62 (0.39–0.92), P = 0.03]. The spline curve in the Figure illustrates the relationship between a'-TDI and the age-adjusted probability of CV events; the association began at about 7 cm/s and increased steeply for lower values. Of note, the association between PALS and CV events was highly significant in younger patients (<70 years, P < 0.001). Conclusions According to our pilot study, a'-TDI can be considered a simple, feasible, and routinely available parameter of left atrial function, which can help to identify HCM patients at higher risk of CV events

440 Assessing cardiac output by echocardiography: is contrast always better?

Abstract Aims Contrast echocardiography is very useful in clinical cardiology. It is mainly performed for the assessment of global left ventricular (LV) function, left ventricular ejection fraction (LVEF), and stroke volume (SV), thanks to improved visualization of endocardial LV borders. Contrast echocardiography, however, is not always easily available, it is more expensive than an ordinary echocardiography and it can be contraindicated in some situations (e.g. in the presence of egg allergy). This study aimed to compare the estimation of cardiac output during traditional transthoracic echocardiography and after the injection of (Sonovue) contrast. Methods and results Patients who underwent an echocardiography with and without injection of (Sonovue) contrast between April 2019 and September 2021 were enrolled in the study. A complete transthoracic echocardiography was performed and Sonovue contrast was then injected. End-diastolic and end-systolic left ventricular volume in apex 4 and 2 chamber views, biplane LVEF with Simpson's formula, end-diastolic and end-systolic left ventricular diameters in parasternal long axis were measured prior and after injecting contrast. Left ventricular outflow tract diameter (LVOTd) was measured and LV outflow tract velocity time integral was traced in order to calculate LVOT VTI SV, as the product of LVOT cross sectional area (assuming that LVOT is circular) to the LVOT VTI. LVOT VTI SV obtained during traditional echocardiography was compared to LVEF SV, calculated as the difference between end-diastolic and end-systolic volume traced after injecting Sonovue contrast. Seventy-eight patients were enrolled in the study. Forty-two had history of CAD, 22 presented dilatative cardiomyopathy, 2 hypertrophic cardiomyopathy (HMC), 1 arrhythmogenic right ventricular dysplasia; 16 had atrial fibrillation, 66 arterial hypertension, and 20 diabetes. The main indications for contrast echocardiography were measurement of EF (39 cases) and exclusion of thrombi in LV apex (18 cases). Other indications were suspect of HCM, atrial myxoma or LV non-compaction. LVOT VTI stroke volume was calculated in 64 patients (LVOT diameter was not well visualized in 8 patients and LVOT VTI could not be measured in 14 patients due to poor acoustic windows). In the same patients LVEF Stroke Volume was also calculated. A strong correlation (P-value < 0.0001) between LVOT stroke volume and LVEF Stroke Volume was found (Figure 1). Conclusions Contrast echocardiography is very useful in clinical practice, however, requires trained physicians and its use is not widespread. This study demonstrates that estimating cardiac output through LVOT VTI SV, in patients with suboptimal echo images can be equally accurate as measuring LVEF SV with contrast echocardiography. This could be particularly useful in the acute settings when contrast echocardiography isn't always feasible and knowing cardiac output can be important for therapeutic implications

Proof of concept study on coronary microvascular function in low flow low gradient aortic stenosis

ObjectivesWe hypothesised that low flow low gradient aortic stenosis (LFLGAS) is associated with more severe coronary microvascular dysfunction (CMD) compared with normal-flow high-gradient aortic stenosis (NFHGAS) and that CMD is related to reduced cardiac performance. MethodsInvasive CMD assessment was performed in 41 consecutive patients with isolated severe aortic stenosis with unobstructed coronary arteries undergoing transcatheter aortic valve implantation (TAVI). The index of microcirculatory resistance (IMR), resistive reserve ratio (RRR) and coronary flow reserve (CFR) were measured in the left anterior descending artery before and after TAVI. Speckle tracking echocardiography was performed to assess cardiac function at baseline and repeated at 6 months. ResultsIMR was significantly higher in patients with LFLGAS compared with patients with NFHGAS (24.1 (14.6 to 39.1) vs 12.8 (8.6 to 19.2), p=0.002), while RRR was significantly lower (1.4 (1.1 to 2.1) vs 2.6 (1.5 to 3.3), p=0.020). No significant differences were observed in CFR between the two groups. High IMR was associated with low stroke volume index, low cardiac output and reduced peak atrial longitudinal strain (PALS). TAVI determined no significant variation in microvascular function (IMR: 16.0 (10.4 to 26.1) vs 16.6 (10.2 to 25.6), p=0.403) and in PALS (15.9 (9.9 to 26.5) vs 20.1 (12.3 to 26.7), p=0.222). Conversely, left ventricular (LV) global longitudinal strain increased after TAVI (-13.2 (8.4 to 16.6) vs -15.1 (9.4 to 17.8), p=0.047). In LFLGAS, LV systolic function recovered after TAVI in patients with preserved microvascular function but not in patients with CMD. ConclusionsCMD is more severe in patients with LFLGAS compared with NFHGAS and is associated with low-flow state, left atrial dysfunction and reduced cardiac performance

Intracoronary physiology-guided percutaneous coronary intervention in patients with diabetes

Objective: The risk of vessel-oriented cardiac adverse events (VOCE) in patients with diabetes mellitus (DM) undergoing intracoronary physiology-guided coronary revascularization is poorly defined. The purpose of this work is to evaluate the risk of VOCE in patients with and without DM in whom percutaneous coronary intervention (PCI) was performed or deferred based on pressure-wire functional assessment. Methods: This is a retrospective analysis of a multicenter registry of patients evaluated with fractional flow reserve (FFR) and/or non-hyperaemic pressure ratio (NHPR). Primary endpoint was a composite of VOCE including cardiac death, vessel-related myocardial infarction (MI), and ischemia-driven target vessel revascularization (TVR). Results: A large cohort of 2828 patients with 3353 coronary lesions was analysed to assess the risk of VOCE at long-term follow-up (23 [14-36] months). Non-insulin-dependent-DM (NIDDM) was not associated with the primary endpoint in the overall cohort (adjusted Hazard Ratio [aHR] 1.18, 95% CI 0.87-1.59, P = 0.276) or in patients with coronary lesions treated with PCI (aHR = 1.30, 95% CI 0.78-2.16, P = 0.314). Conversely, insulin-dependent diabetes mellitus (IDDM) demonstrated an increased risk of VOCE in the overall cohort (aHR 1.76, 95% CI 1.07-2.91, P = 0.027), but not in coronary lesions undergoing PCI (aHR 1.26, 95% CI 0.50-3.16, P = 0.621). Importantly, in coronary lesions deferred after functional assessment IDDM (aHR 2.77, 95% CI 1.11-6.93, P = 0.029) but not NIDDM (aHR = 0.94, 95% CI 0.61-1.44, P = 0.776) was significantly associated with the risk of VOCE. IDDM caused a significant effect modification of FFR-based risk stratification (P for interaction < 0.001). Conclusion: Overall, DM was not associated with an increased risk of VOCE in patients undergoing physiology-guided coronary revascularization. However, IDDM represents a phenotype at high risk of VOCE