3,814 research outputs found

    Adjoint bi-continuous semigroups and semigroups on the space of measures

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    For a given bi-continuous semigroup T on a Banach space X we define its adjoint on an appropriate closed subspace X^o of the norm dual X'. Under some abstract conditions this adjoint semigroup is again bi-continuous with respect to the weak topology (X^o,X). An application is the following: For K a Polish space we consider operator semigroups on the space C(K) of bounded, continuous functions (endowed with the compact-open topology) and on the space M(K) of bounded Baire measures (endowed with the weak*-topology). We show that bi-continuous semigroups on M(K) are precisely those that are adjoints of a bi-continuous semigroups on C(K). We also prove that the class of bi-continuous semigroups on C(K) with respect to the compact-open topology coincides with the class of equicontinuous semigroups with respect to the strict topology. In general, if K is not Polish space this is not the case

    Level 3 Assessment of Highway Girder Deck Bridges according to the Italian Guidelines: Influence of Transverse Load Distribution

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    The Italian Ministry of Infrastructure and Transportation adopted the guidelines on risk classification and management, safety assessment and monitoring of existing bridges through the Decree No. 578 dated 17 December 2020. This document must be used by all managing entities to prevent damage due to a lack of maintenance to these crucial components of the infrastructure system. The approach of the guidelines for existing bridges is developed across six levels, ranging from Level 0 to Level 5. The research work presented in this article is focused on Level 3, which pertains to preliminary assessments conducted on existing bridges. Through an automated procedure, the preliminary verification is performed by comparing bending and shear stress generated by traffic load schemes extracted from previous standards with the ones based on the current code. These loads are applied to a series of girder deck models, selected through a statistical study conducted on a database of bridges. Performance indices are derived from the comparison to evaluate the adequacy of previously designed and constructed structures by applying the load models specified in the current regulations for designing new bridges. The analysis results highlight a performance gap, which varies depending on the standard code at hand

    Un'applicazione della Social Network Analisys alla rete di relazioni di un Gruppo d’Acquisto Solidale: l’esperienza di Gasualmente

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    The phenomenon of GAS (Solidarity Purchase Groups) in Sicily has in Gasualmente an important actor. This GAS, was created following a structured training program and research by the Faculty of Agriculture of the University of Palermo. It now plays an important role as activator of relationships and ethical affirmation of critical consumption, and promotion of organic products. The study aims through the Social Network Analysis, to investigate Gasualmente network and the role played by all the actors involved

    Mirror Inversion of Quantum States in Linear Registers

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    Transfer of data in linear quantum registers can be significantly simplified with pre-engineered but not dynamically controlled inter-qubit couplings. We show how to implement a mirror inversion of the state of the register in each excitation subspace with respect to the centre of the register. Our construction is especially appealing as it requires no dynamical control over individual inter-qubit interactions. If, however, individual control of the interactions is available then the mirror inversion operation can be performed on any substring of qubits in the register. In this case a sequence of mirror inversions can generate any permutation of a quantum state of the involved qubits.Comment: 4 page

    Long-term ocular biometric variations after scleral buckling surgery in macula-on rhegmatogenous retinal detachment

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    Background: Myopic shift and biometric ocular changes have been previously observed after scleral buckling (SB) surgery in rhegmatogenous retinal detachment (RRD), but long term-term outcomes had not yet been explored. The purpose of present study is to evaluate long term ocular biometric changes in patients with primary macula-on RRD treated with SB. Methods: In this retrospective, observational study, we reviewed the medical records of patients undergoing SB surgery for macula-on RRD. Ocular biometry was performed before and at the most recent visit after surgery. Axial length (AXL), anterior chamber depth (ACD), anterior corneal astigmatism and spherical equivalent in treated eyes were compared before and after surgery as well as with those of fellow eyes. Results: Thirty-four eyes of 17 patients with a mean age of 57.0 ± 8.9 years were included. The mean follow-up duration was 50.9 ± 21.9 months (median 53.0; range 12 to 82 months). A significant postoperative AXL increase of 0.83 mm and a concomitant myopic shift of 1.35 diopters was observed in the operated eyes (p < 0.0001). The preoperative AXL was the only predictive factor of AXL change after surgery (B = 0.152, 95% CI 0.059 to 0.245, β = 0.668, P = 0.003). Compared to fellow eyes, a postoperative ACD shallowing of 0.1 mm was found in operated eyes (p < 0.05), while there were no long-term changes of anterior corneal astigmatism. Conclusions: We show that the preoperative AXL is the only predictive factor of AXL increase after SB surgery. Scleral encircling induces a concomitant long-term shallowing of the AC, therefore fourth generation intraocular lens (IOL) power calculation formulae should be used for patients requiring cataract surgery after SB

    Paraneoplastic Acanthosis Nigricans Maligna

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    Acanthosis Nigricans Maligna (ANM) is a paraneoplastic syndrome, defined as a condition that arises in association with a malignancy elsewhere in the body but without malignant nature per se. It’s a rare dermatopathy that occurs in men and women over age 40, without racial predilection or known familial association. Clinically, ANM showed symmetric,hyperpigmented plaques with variable amounts of epidermal hypertrophy, ranging in color from yellow to brown or black, often with overlaid papillomas. The most common affected sites are body flexures and the posterior neck, but also mucosal surface involvement is frequent and may be the only clinical symptom present. Any mucosal surface can be involved, and as regards the oral cavity, disease affects the lips, tongue, palate, buccal and gingival mucosa.ANM is primarily associated with adenocarcinomas, mostly of gastric origin. Accordingly, the progression of the tumor will lead to a worsening of the ANM, while regress in case of tumour treatment, and resurface with recurrence and metastases. A 62-year-old man was referred for evaluation of papillomatous lesions of the oral mucosa, appeared in previous months. The patient was diagnosed a gastric adenocarcinoma at an advanced stage 6 months before. Clinical examination showed diffuse papillomatous or wart-like areas of normal mucosal color and soft consistency involving lips,oral mucosa and hard palate. The tongue and the vestibular mucosa were thickened and furrowed. The lesions are asymptomatic. A biopsy was performed, and histopathological analysis revealed acanthosis and papillomatosis, hyperkeratosis,and lymphohistiocytic infiltrate. The patient was clinically diagnosed with ANM, according to clinical and histologic findings, and the patient’s medical history. Isotretinoin 0,05% was prescribed for local therapy. The patient did not return to follow-up due to complications of gastric adenocarcinoma, and died 6 months late

    Long-term clinical efficacy of topical treatment with recombinant human nerve growth factor in neurotrophic keratopathy: a novel cure for a rare degenerative corneal disease?

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    Background Neurotrophic keratopathy (NK) is a rare, degenerative ocular disease characterized by reduction or loss of corneal sensitivity and development of non-healing corneal epithelial defects and ulcers. Cenegermin, a recombinant human nerve growth factor (rhNGF) eye drop solution, is the first drug approved for the treatment of NK. The aim of our study is to evaluate the long-term efficacy of this innovative topical treatment in patients with NK. Methods Retrospective, consecutive, observational case series study from a single-center setting (Department of Sense Organs, University Sapienza of Rome, Rome, Italy). 18 patients with diagnosis of stage 2 or 3 NK, treated with Cenegermin 20 mcg/ml eye drops were followed for up to 48 months. Recurrence of lesion during follow-up was evaluated at 12, 24, 36, and 48 months. In addition, corneal sensitivity, Schirmer tear test, and visual acuity (VA) were recorded at baseline, end of treatment, and at 12, 24, 36, and 48 months. Results Three patients experienced recurrence of persistent epithelial defects (PEDs) within 12 months and one patient experienced recurrence of a corneal ulcer within 36 months. Corneal sensitivity was significantly improved at all timepoints (P < 0.05). Significant improvements in visual acuity and tear production were seen at the completion of treatment as well as at 12, 24, and 36 months (P < 0.05) when compared to baseline. Conclusions A single 8-week treatment regimen of Cenegermin eye drops has clinical efficacy that can persist for up to 48 months. The long-term clinical utility of treatment with Cenegermin for NK was demonstrated through the low rate of lesion recurrence along with improvements in corneal sensitivity and tear production

    Generalized Rayleigh and Jacobi processes and exceptional orthogonal polynomials

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    We present four types of infinitely many exactly solvable Fokker-Planck equations, which are related to the newly discovered exceptional orthogonal polynomials. They represent the deformed versions of the Rayleigh process and the Jacobi process.Comment: 17 pages, 4 figure

    The surgical treatment of mandibular peripheral calcifying epithelial odontogenic tumour (pindborg tumor) with Er,Cr:YSGG laser: a case report.\u201d

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    The aim of this case report was to propose a new treatment modality of peripheral calcifying epithelial odontogenic tumour (CEOT) using Er, Cr: YSGG laser

    Lunar laser ranging in infrfared at hte Grasse laser station

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    For many years, lunar laser ranging (LLR) observations using a green wavelength have suffered an inhomogeneity problem both temporally and spatially. This paper reports on the implementation of a new infrared detection at the Grasse LLR station and describes how infrared telemetry improves this situation. Our first results show that infrared detection permits us to densify the observations and allows measurements during the new and the full Moon periods. The link budget improvement leads to homogeneous telemetric measurements on each lunar retro-reflector. Finally, a surprising result is obtained on the Lunokhod 2 array which attains the same efficiency as Lunokhod 1 with an infrared laser link, although those two targets exhibit a differential efficiency of six with a green laser link
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