169,739 research outputs found
Le fonti storico-educative per il rinnovamento della didattica universitaria. L'esperienza del laboratorio di Storia dell'Educazione dell'Università degli Studi di Macerata
No full textNegli ultimi anni la ricerca storico-educativa ha subìto profonde trasformazioni, dovute a un rinnovamento tematico e metodologico e all’individuazione di nuovi filoni d’indagine, tra cui quello legato alla valorizzazione e alla tutela del patrimonio materiale scolastico. Numerose sono le ricerche finalizzate all’esaltazione del potenziale euristico di tale fonte, mentre limitate sono quelle relative alla sua pratica applicazione in ambito scolastico e universitario. A questo proposito, il presente contributo intende descrivere un’innovativa esperienza didattica, svolta sia in presenza sia in modalità telematica, e rivolta agli studenti del primo anno del corso di laurea in Scienze dell’Educazione e della Formazione – presso l’Università degli Studi di Macerata –, dedicata all’indagine e all’osservazione di fonti storico-educative novecentesche, diverse per tipologia e fine educativo. Nello specifico, attraverso un’attività di cooperative learning, il cospicuo pubblico di studenti ha direttamente sperimentato l’analisi storico-educativa di fonti materiali, al fine di evidenziarne le principali caratteristiche e il valore pedagogico assunto nel contesto preso in esame
Book embeddings of k-framed graphs and k-map graphs
No full textAn embedding of a graph in a book, called book embedding, consists of a linear ordering of its vertices along the spine of the book and an assignment of its edges to the pages of the book, so that no two edges on the same page cross. The book thickness of a graph is the minimum number of pages over all its book embeddings. For planar graphs, a fundamental result is due to Yannakakis, who proposed an algorithm to compute embeddings of planar graphs in books with four pages. Our main contribution is a technique that generalizes this result to a much wider family of nonplanar graphs, namely to k-map graphs. In fact, our technique can deal with any nonplanar graph having a biconnected skeleton of crossingfree edges whose faces have bounded degree. We prove that this family of graphs has book thickness bounded in k, and as a corollary, we obtain the first constant upper bound for the book thickness of optimal 2-planar graphs. (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons .org /licenses /by /4 .0/)
Placing Arrows in Directed Graph Layouts: Algorithms and Experiments
No full textWe study how to place arrow heads in directed graph drawings aiming at minimizing their overlaps and avoiding intersections between arrow heads and edges. The objective is to support users to correctly and quickly recognize edge orientations, i.e. to deduce unambiguously the edge orientations. Our contribution is two-fold: (i) We present exact and heuristic algorithms for this arrow placement problem, along with an extensive experimental analysis of these techniques; and (ii) we report on a user study aimed to understand the impact of different arrow placement strategies on performing global and local analysis tasks on directed graph layouts
Spastic paraplegia type 4: A novel SPAST splice site donor mutation and expansion of the phenotype variability
No full textMutations in SPG4/SPAST are the most frequent molecular aetiology in the autosomal dominant form of hereditary spastic paraplegia (HSP). Loss-of-function and haploinsufficiency in SPAST have been demonstrated and the pure form of spastic paraplegia is a main clinical manifestation. This study is to explore the novel SPAST splice site donor variant, c.1004+3A>C, in seven patients from two families, one from Italy and the other from Japan. Exon 6 is skipped out by the variant, leading to a premature termination of translation, p.Gly290Trpfs*5. Measurement of SPAST transcripts in lymphocytes demonstrated a reduction through nonsense-mediated mRNA decay (NMD). Intra- and inter-familial phenotypic variations were observed, including age-at-onset, severity of spasticity, and scoliosis. Our study demonstrated further evidence of allelic heterogeneity in SPG4, dosage effects through NMD, and broad clinical features of the SPAST mutation
Vin, enfants et éducation: premiers essais sur l’imaginaire éducatif italien entre 1800 et 1900
No full textMinimally invasive versus standard extracorporeal circulation system in minimally invasive aortic valve surgery: a propensity score-matched study
No full textOBJECTIVES: The impact of minimally invasive extracorporeal circulation (MiECC) systems on the clinical outcomes of patients undergoing minimally invasive aortic valve replacement (MI-AVR) has still to be defined. This study compared in-hospital and 1 year outcomes of MI-AVR interventions using MiECC systems versus conventional extracorporeal circulation (c-ECC). METHODS: Data from 288 consecutive patients undergoing primary isolated MI-AVR using MiECC (n = 102) or c-ECC (n = 186) were prospectively collected. Treatment selection bias was addressed by the use of propensity score matching (MiECC vs c-ECC). After propensity score matching, 2 groups of 93 patients each were created. RESULTS: Compared with c-ECC, MiECC was associated with a higher rate of autologous priming (82.4% vs 0%; P < 0.001) and a greater nadir haemoglobin (9.3 vs 8.7 g/dl; P = 0.021) level and haematocrit (27.9% vs 26.4%; P = 0.023). Patients who had MiECC were more likely to receive ultra-fast-track management (60.8% vs 26.9%; P < 0.001) and less likely to receive blood transfusions (32.7% vs 44%; P = 0.04). The in-hospital mortality rate was 1.1% in the MiECC group and 0% in the c-ECC group (P = 0.5). Those in the MiECC group had reduced rates of bleeding requiring revision (0% vs 5.3%; P = 0.031) and postoperative atrial fibrillation (AF) (30.1% vs 44.1%; P = 0.034). The 1-year survival rate was 96.8% and 97.5% for MiECC and c-ECC patients, respectively (P = 0.4). CONCLUSIONS: MiECC systems were a safe and effective tool in patients who had MI-AVR. Compared with c-ECC, MiECC promotes ultra-fast-track management and provides better clinical outcomes as regards bleeding, blood transfusions and postoperative AF. Thus, by reducing surgical injury and promoting faster recovery, MiECC may further validate MI-AVR interventions
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Spastic paraplegia type 31: A novel REEP1 splice site donor variant and expansion of the phenotype variability
No full textMutations in REEP1 have been identified in three types of neurological disorders, autosomal dominant form of Hereditary Spastic Paraplegia type 31 (SPG31), autosomal dominant distal hereditary motor neuronopathy type VB (HMN5B), and autosomal recessive form of congenital axonal neuropathy and diaphragmatic palsy. Previous studies demonstrated different molecular pathogenesis in SPG31, including loss-of-function, gain-of-function and haploinsufficiency. A four-generation family from Japan, including 12 members, was investigated clinically and genetically. Seven affected members displayed pure spastic paraplegia. Impression of genetic anticipation was observed in the family, including tendency of earlier age-at-onset and increasing severity in subsequent generations. Genetic analysis revealed a heterozygous intronic variant, c.303+2T > A, in REEP1, which segregated with disease, and was also identified in one unaffected member. The variant causes exon 4 skipping leading to frame shift and a truncated transcript identified by complementary DNA sequencing of reverse transcription polymerase chain reaction products. Measurement of REEP1 transcripts in lymphocytes demonstrated a reduction through nonsense mediated mRNA decay (NMD). Our study demonstrated further evidence of allelic heterogeneity in SPG31, mutant REEP1 mRNA dosage effects through NMD and intra-familial phenotype variability
Planar graphs of bounded degree have bounded queue number
No full textA queue layout of a graph consists of a linear order of its vertices and a partition of its edges into queues, so that no two independent edges of the same queue are nested. The queue number of a graph is the minimum number of queues required by any of its queue layouts. A long-standing conjecture by Heath, Leighton and Rosenberg [SIAM J. Discrete Math., 5 (1992), pp. 398--412] states that the queue number of planar graphs is bounded. This conjecture has been partially settled in the positive for several subfamilies of planar graphs (most of which have bounded treewidth). In this paper, we make a further important step towards settling this conjecture. We prove that planar graphs of bounded degree (which may have unbounded treewidth) have bounded queue number. A notable implication of this result is that every planar graph of bounded degree admits a three-dimensional straight-line grid drawing in linear volume. Further implications are that every planar graph of bounded degree has bounded track number, and that every -planar graph (i.e., every graph that can be drawn in the plane with at most crossings per edge) of bounded degree has bounded queue number
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