A note on the Krylov solvability of compact normal operators on Hilbert space

We analyse the Krylov solvability of inverse linear problems on Hilbert space $\mathcal{H}$ where the underlying operator is compact and normal. Our results explicitly describe the Krylov subspace for such operators given any datum vector $g\in\mathcal{H}$, as well as prove that all inverse linear problems are Krylov solvable provided that $g$ is in the range of the operator. We close the study by proving an isomorphism between the closed Krylov subspace for a general bounded normal operator and an $L^2$-measure space based on the scalar spectral measure

On Krylov Methods in Infinite-dimensional Hilbert Space

This thesis contains the development of key features for the solution to inverse linear problems Af = g on infinite-dimensional Hilbert space H using projection methods. Particular attention is paid to Krylov subspace methods. Intrinsic, key operator-theoretic constructs that guarantee the \u2018Krylov solvability\u2019 of the problem Af = g are developed and investigated for this class of projection methods. This theory is supported by numerous examples, counterexamples, and some numerical tests. Results for both bounded and unbounded operators on general Hilbert spaces are considered, with special attention paid to the Krylov method of conjugate-gradients in the unbounded setting

The Adoption of Information Systems in SMEs: Organizational Issues and Success Factors

This research approaches the issues of introducing ICTs (Information and Communication Technologies) into Small and Medium Enterprises, with the aim of finding some conditions that make the organizational context able to manage the change process needed to really get the potential benefits of these technologies. The final objective is to propose a theoretical base for a methodology able to improve analytical and diagnostic capabilities of organizational realities before and during planning and evaluation phases of their Information Technology investments. The study is planned to go through two phases. The first one is aimed to look for reliable indicators to forecast readiness and adequacy of a specific organizational context towards the positive adoption of I.T. systems through a deep analysis of five significant cases. The second phase will test such indicators through questionnaire research on a larger sample of Italian SMEs

ASTRONOMICAL CALIBRATION OF THE SERRAVALLIAN/TORTONIANCASE PELACANI SECTION (SICILY, ITALY)

We performed a cyclostratigraphic study of a sedimentary sequence (Case Pelacani section) outcropping in the south-eastern margin of Sicily (Italy) and covering the Upper Serravallian/Lower Tortonian stratigraphic interval. Calcareous plankton biostratigraphic data reported in another paper proved that all the sequence of bio-events generally reported from just below and above the S/T boundary is present in the section. They allowed a detailed correlation with the Gibliscemi section.  Preliminary paleomagnetic data suggest that a secondary remagnetization  component prevents the recognition of the correct sequence of paleomagnetic chrons along the studied interval. The sedimentary record has been compared, on the basis of an integrated calcareous plankton biostratigraphy, with that of the Gibliscemi section. Cyclostratigraphic analysis of the lithological patterns recognized throughout the succession and the application of spectral methodologies to the abundance fluctuations of the planktonic foraminifer Globigerinoides quadrilobatus highlighted the presence in the signal of the classic Milankovitch frequencies (precession, obliquity and eccentricity). Correlation of the lithological patterns and of the different frequency bands extracted by numerical filtering from the faunal record with the same components modulating the insolation curve provided an astronomic calibration of the sedimentary record and, consequently, a precise age for all the calcareous plankton bioevents recognized throughout the studied interval.&nbsp

Endoscopic Submucosal Dissection of Gastric Neoplastic Lesions. An Italian, Multicenter Study

Endoscopic submucosal dissection (ESD) allows removing neoplastic lesions on gastric mucosa, including early gastric cancer (EGC) and dysplasia. Data on ESD from Western countries are still scanty. We report results of ESD procedures performed in Italy. Data of consecutive patients who underwent ESD for gastric neoplastic removal were analyzed. The en bloc resection rate and the R0 resection rates for all neoplastic lesions were calculated, as well as the curative rate (i.e., no need for surgical treatment) for EGC. The incidence of complications, the one‐month mortality, and the recurrence rate at one‐year follow‐up were computed. A total of 296 patients with 299 gastric lesions (80 EGC) were treated. The en bloc resection was successful for 292 (97.6%) and the R0 was achieved in 266 (89%) out of all lesions. In the EGC group, the ESD was eventually curative in 72.5% (58/80) following procedure. A complication occurred in 30 (10.1%) patients. Endoscopic treatment was successful in all 3 perforations, whereas it failed in 2 out of 27 bleeding patients who were treated with radiological embolization (1 case) or surgery (1 case). No procedure‐related deaths at one‐month follow‐up were observed. Lesion recurrence occurred in 16 (6.2%) patients (6 EGC and 10 dysplasia). In conclusion, the rate of both en bloc and R0 gastric lesions removal was very high in Italy. However, the curative rate for EGC needs to be improved. Complications were acceptably low and amenable at endoscopy

Recent jaguar records confirm the conservation value of the Baritú–Tariquía corridor between Argentina and Bolivia

Effective transboundary corridors play a crucial role in jaguar Panthera onca conservation. Local residents reported jaguar sightings along the Baritú–Tariquía Biological Corridor, which prompted us to carry out this camera-trap survey. We surveyed an area of 1,243 km2 across the corridor to confirm jaguar presence. We used 50 single camera stations, with cameras placed c. 5 km apart. We placed the cameras along trails, streams and mountain ridges. We recorded jaguars at seven sites across the Corridor; at least three different individuals were identified. These records confirm the presence of the jaguar in the Baritú–Tariquía Biological Corridor between Argentina and Bolivia, a trans-frontier area of the Austral Yungas facing multiple threats but hosting one of the southernmost jaguar populations. Conservation efforts in border regions can promote collaboration and synergies between agencies and other conservation stakeholders, with important implications for wide-ranging predators such as jaguars and their habitats

Predictors of Response to Intradetrusor Botulinum Toxin-A Injections in Patients with Idiopathic Overactive Bladder

Objectives. To evaluate whether there are any demographic or urodynamic differences in patients with idiopathic overactive bladder (I-OAB) that respond and do not respond to intradetrusor injections of botulinum toxin-A (BTX-A). Methods. This represents a secondary analysis of data collected from an investigator initiated randomized trial designed to evaluate clinical differences in outcomes for 100 versus 150 U BTX-A in patients with I-OAB. Preinjection demographic and urodynamic data were collected. Patients were evaluated 12 weeks after injection and were determined to be responders or nonresponders as defined by our criteria. Statistical comparisons were made between groups. Results. In patients with overactive bladder without incontinence (OAB-Dry), there were no variables that could be used to predict response to BTX-A. On univariate analysis, younger patients with overactive bladder with incontinence (OAB-Wet) were more likely to respond to BTX-A than older patients. However, this relationship was no longer statistically significant on multivariate analysis. Conclusions. We were unable to identify any preinjection demographic or urodynamic parameters that could aid in predicting which patients will achieve clinical response to BTX-A. Future studies are necessary to further evaluate this question

Double localization and multiple recurrences of dermatofibrosarcoma protuberans of the female breast: A rare clinical case

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