2,817 research outputs found
Organized crime, the quality of local institutions and FDI in Italy: A panel data analysis
This paper examines the impact of crime on foreign direct investment (FDI) inflows in the
Italian provinces. The incidence of organized crime is measured by the number of complaints
regarding criminal offences of different kinds traditionally related to the mafia organizations.
The results show how the correlation between organized crime and FDI is both negative and
significant, even when an indicator of financial incentives for investment is included in the
regressions. Our analysis shows that crime represents a deterrent for foreign investors,
suggesting that high levels of (certain) crimes may be perceived as a signal of a local socioinstitutional
environment unfavourable for FDI
Professor Ugo Carraro and BAM: two friends for life
Not available
Picard group of hypersurfaces in toric 3-folds
We show that the usual sufficient criterion for a generic hypersurface in a
smooth projective manifold to have the same Picard number as the ambient
variety can be generalized to hypersurfaces in complete simplicial toric
varieties. This sufficient condition is always satisfied by generic K3 surfaces
embedded in Fano toric 3-folds.Comment: 14 pages. v2: some typos corrected. v3: Slightly changed title. Final
version to appear in Int. J. Math., incorporates many (mainly expository)
changes suggested by the refere
Grafting Autologous Cortical Bone in Regenerative Therapy: Preliminary Histological Evidence.
Vedasi l'allegat
Time Minimal Trajectories for a Spin 1/2 Particle in a Magnetic Field
In this paper we consider the minimum time population transfer problem for
the -component of the spin of a (spin 1/2) particle driven by a magnetic
field, controlled along the x axis, with bounded amplitude. On the Bloch sphere
(i.e. after a suitable Hopf projection), this problem can be attacked with
techniques of optimal syntheses on 2-D manifolds. Let be the two
energy levels, and the bound on the field amplitude. For
each couple of values and , we determine the time optimal synthesis
starting from the level and we provide the explicit expression of the time
optimal trajectories steering the state one to the state two, in terms of a
parameter that can be computed solving numerically a suitable equation. For
, every time optimal trajectory is bang-bang and in particular the
corresponding control is periodic with frequency of the order of the resonance
frequency . On the other side, for , the time optimal
trajectory steering the state one to the state two is bang-bang with exactly
one switching. Fixed we also prove that for the time needed to
reach the state two tends to zero. In the case there are time optimal
trajectories containing a singular arc. Finally we compare these results with
some known results of Khaneja, Brockett and Glaser and with those obtained by
controlling the magnetic field both on the and directions (or with one
external field, but in the rotating wave approximation). As byproduct we prove
that the qualitative shape of the time optimal synthesis presents different
patterns, that cyclically alternate as , giving a partial proof of a
conjecture formulated in a previous paper.Comment: 31 pages, 10 figures, typos correcte
TRANSFORMATIONAL LEADERSHIP AND ITS EFFECT ON EMPLOYEE PSYCHOLOGICAL WELL-BEING IN SELECTED DELTA STATE BROADCAST STATIONS
Main Objective: This study examined the effect of transformational leadership on the employee psychological well-being in selected Delta State broadcasting stations. Background Problems: Managers and governments across the globe are concerned about employee psychological health. Organizations in Nigeria have paid little attention to their employees' psychological well-being, and the majority of top executives in the broadcasting industry are unaware of the impact that transformational leadership has on the workforce's psychological well-being. The goal of this research is to investigate transformational leadership and its effect on employee psychological well-being in selected sample of Delta State broadcasting stations. Novelty: Transformational leadership is an effective type of leadership that encourages workers to perform better by increasing their levels of competence and self-reinforcement. Research Methods: The cross-sectional research design approach was used in this study. The participants in this study included 173 management and non-management employees from the Nigerian Television Authority in Asaba (47) and the Delta State Broadcasting Services in Asaba (69) and Warri (57) respectively. Using the SPSS software version 23.0, data was analyzed using linear regression. Findings/Results: According to the findings, transformational leadership had a significant and positive effect on employee psychological well-being. Conclusion: Transformational leaders work toward a common goal with followers, often self-sacrificing, prioritize employees, and develop them
Is contrast-enhanced US alternative to spiral CT in the assessment of treatment outcome of radiofrequency ablation in hepatocellular carcinoma?
Purpose: The present study was conducted to assess the efficacy of contrast-enhanced ultrasound with low mechanical index in evaluating the response of percutaneous radiofrequency ablation treatment of hepatocellular carcinoma by comparing it with 4-row spiral computed tomography. Materials and Methods: 100 consecutive patients (65 men and 35 women; age range: 62 – 76 years) with solitary hepatocellular carcinomas (mean lesion diameter: 3.7cm± 1.1cm SD) underwent internally cooled radiofrequency ablation. Therapeutic response was evaluated at one month after the treatment with triple-phasic contrast-enhanced spiral CT and low-mechanical index contrast-enhanced ultrasound following bolus injection of 2.4 ml of Sonovue (Bracco, Milan). 60 out of 100 patients were followed up for another 3 months. Contrast-enhanced sonographic studies were reviewed by two blinded radiologists in consensus. Sensitivity, specificity, NPV and PPV of contrast-enhanced ultrasound examination were determined. Results: After treatment, contrast-enhanced ultrasound identified persistent signal enhancement in 24 patients (24%), whereas no intratumoral enhancement was detected in the remaining 76 patients (76%). Using CT imaging as gold standard, the sensitivity, specificity, NPV, and PPV of contrast enhanced ultrasound were 92.3% (95% CI = 75.9 – 97.9%), 100% (95% CI = 95.2 – 100%), 97.4% (95% CI = 91.1 – 99.3%), and 100% (95% CI = 86.2 – 100%). Conclusion: Contrast-enhanced ultrasound with low mechanical index using Sonovue is a feasible tool in evaluating the response of hepatocellular carcinoma to radiofrequency ablation. Accuracy is comparable to 4-row spiral CT
From eventual to atomic and locally atomic CC programs: A concurrent semantics
We present a concurrent semantics (i.e. a semantics where
concurrency is explicitely represented) for CC programs with atomic tells. This allows to derive concurrency, dependency, and nondeterminism information for such languages. The ability to treat failure information
puts CLP programs also in the range of applicability of our semantics: although such programs are not concurrent, the concurrency information derived in the semantics may be interpreted as possible parallelism, thus allowing to safely parallelize those computation steps which appear to be concurrent in the net. Dually, the dependency information may also be interpreted as necessary sequentialization, thus possibly exploiting it to schedule CC programs. The fact that the semantical structure contains
dependency information suggests a new tell operation, which checks for consistency only the constraints it depends on, achieving a reasonable trade-off between efficiency and atomicity
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