1,125 research outputs found
Permutation patterns in genome rearrangement problems
In the context of the genome rearrangement problem, we analyze two well known
models, namely the block transposition and the prefix block transposition
models, by exploiting the connection with the notion of permutation pattern.
More specifically, for any , we provide a characterization of the set of
permutations having distance from the identity (which is known to be a
permutation class) in terms of what we call generating permutations and we
describe some properties of its basis, which allow to compute such a basis for
small values of .Comment: 8 pages. In: L. Ferrari, M. Vamvakari (eds.): Proceedings of the
GASCom 2018 Workshop, Athens, Greece, 18--20 June 2018, published at
http://ceur-ws.or
A regularity result for a class of non-uniformly elliptic operators
We obtain an explicit H\"older regularity result for viscosity solutions of a
class of second order fully nonlinear equations leaded by operator that are
neither convex/concave nor uniformly elliptic.Comment: 9 page
Double-Biguanide Therapy for Resistant Acanthamoeba Keratitis
Aims: To report the clinical and diagnostic findings of a patient with Acanthamoeba keratitis resistant to both polyhexamethylene biguanide (PHMB)-hexamidine and chlorhexidine-hexamidine treatment. Methods: Slit-lamp biomicroscopy, corneal cell scraping and histopathology were performed on a 39-year-old woman presenting with corneal ulcer in her left eye. Results: The patient was successfully treated with PHMB-chlorhexidine association therapy. Subsequent perforating keratoplasty remained clear at the last follow-up visit after 7 months and increased visual acuity to 20/20 with correction. Conclusions: This case emphasizes the proteiform aspects of Acanthamoeba drug resistance, and suggests that PHMB-chlorhexidine association might represent an additional option for cases resistant to standard therapy
Conductance crossovers in coherent surface transport on y nanojunctions
Conductance characteristics of a nonplanar two-dimensional electron gas (2DEG) can expose the role of its bending on the 2DEG electronic states. In particular, the presence of an effective geometric potential can be revealed. Here, we present a numerical study of the coherent electron transport on Y nanojunctions of three cylindrical 2DEGs, including a proposal for the experimental detection of the geometric potential. We describe the analytical approach leading to the reduction of the problem dimensionality from 3D to 2D and sketch our simulation scheme. © 2009 IOP Publishing Ltd
VesselJ: A New Tool for Semiautomatic Measurement of Corneal Neovascularization
PURPOSE. To quantify blood and lymph angiogenesis in mouse corneal flat mounts by means of a novel plug-in for ImageJ, called VesselJ, based on a dynamic threshold algorithm. METHODS. Corneal neovascularization (CNV) was induced in the right corneas of 20 C57BL6/N mice by means of alkali burn (n ¼ 10) or intrastromal sutures (n ¼ 10). All corneal flat mounts were stained for blood vessels with CD31 and for lymphatics with LYVE1. Three independent operators measured blood and lymphatic CNV with both a published manual method (mCNV) and VesselJ (automatic method; aCNV). RESULTS. Both methods showed a strong reliability, defined as intraclass correlation coefficient (ICC) > 0.90, in quantifying hemangiogenesis for sutures and alkali burn. However, reliability of lymphatic mCNV varied from moderate in alkali burn (ICC: 0.700) to poor in sutures (ICC: 0.415), whereas it remained high in aCNV (alkali ICC: 0.996; sutures ICC: 0.959). Among sutures, a significant correlation between mCNV and aCNV was found among all the three operators for blood vessels and just for one operator for lymphatic vessels (P < 0.001). In the alkali burn model, correlation between blood mCNV and aCNV was significant for all operators after excluding three noisy flat mounts (P < 0.001), whereas no significant correlation was seen for lymphatic vessels. CONCLUSIONS. VesselJ is a semiautomatic, reliable, and fast method to quantify corneal hem-and lymphangiogenesis in corneal flat mounts. VesselJ can be easily used in the sutures model; it should be applied to other models (e.g., alkali burn) only after checking for background hyperfluorescence. Keywords: corneal neovascularization, blood vessels, lymphatics, plug-in, ImageJ SCOPO. Quantificare l'angiogenesi e la linfangiogenesi su cornee murine tramite un nuovo plugin per ImageJ, chiamato VesselJ, basato su un algoritmo dinamico per la determinazione di un valore soglia. METODI. La neovascolarizzazione corneale (CNV)è stata indotta nella cornea destra di 20 topi C57BL6/N tramite ustione da alcali (n ¼ 10) o applicazione di suture intrastromali (n ¼ 10). Le cornee sono state marcate per i vasi sanguigni con CD31 e per i linfatici con LYVE1. Tre operatori indipendenti hanno misurato la CNV ematica e linfatica con un metodo manuale precedentemente pubblicato (mCNV) e con VesselJ (aCNV). RISULTATI. Entrambi i metodi hanno mostrato una forte riproducibilità , definita da valori di Coefficiente di Correlazione Intraclasse (ICC) > 0.90, nel quantificare l'angiogenesi in entrambi i modelli. Tuttavia, la riproducibilità del mCNV linfatico variava da moderata nell'ustione da alcali (ICC: 0.700) a scarsa nelle suture (ICC:0.415), mentre rimaneva sempre alta nell'aCNV (ICC alcali: 0.996; ICC suture: 0.959). Riguardo il modello suture,è stata osservata una correlazione significativa tra mCNV e aCNV per tutti gli operatori riguardo i vasi ematici e per solo un operatore per i vasi linfatici (P < 0.001). Nel modello dell'ustioneè stata osservata una correlazione significativa tra mCNV e aCNV ematici per tutti gli operatori dopo aver escluso 3 immagini con elevato rapporto segnale/rumore (P < 0.001), viceversa nessuna correlazione significativaè stata osservata per i vasi linfatici. CONCLUSIONI. VesselJè un metodo semi-automatico, preciso e rapido per quantificare angiogenesi e linfangiogenesi su cornee murine. VesselJ può essere agevolmente impiegato nel modello suture, ma dovrebbe essere applicato ad altri modelli (es. ustione da alcali) solo dopo aver controllato l'iperfluorescenza di fondo
Sorting with pattern-avoiding stacks : the 132-machine
This paper continues the analysis of the pattern-avoiding sorting machines recently introduced by Cerbai, Claesson and Ferrari (2020). These devices consist of two stacks, through which a permutation is passed in order to sort it, where the content of each stack must at all times avoid a certain pattern. Here we characterize and enumerate the set of permutations that can be sorted when the first stack is 132-avoiding, solving one of the open problems proposed by the above mentioned authors. To that end we present several connections with other well known combinatorial objects, such as lattice paths and restricted growth functions (which encode set partitions). We also provide new proofs for the enumeration of some sets of pattern-avoiding restricted growth functions and we expect that the tools introduced can be fruitfully employed to get further similar results
Electronic and magnetic states in core multishell nanowires: Edge localization, Landau levels and Aharonov-Bohm oscillations
We study the electronic states of hexagonal core multishell semiconductor nanowires, including the effect of magnetic fields. We find that the two dimensional electron states formed at the interface between different layers are mostly localized at the six edges of the hexagonal prism, and behave as a set of quasi-1D quantum channels. They can be manipulated by magnetic fields either parallel or perpendicular to the wire axis. These results can be rationalized in terms of Aharonov-Bohm oscillations or Landau level formation. We also show that inter-channel coupling and magnetic behavior is influenced by the geometric details of the nanowires. © 2009 IOP Publishing Ltd
4.0 technologies in city logistics: an empirical investigation of contextual factors
Industry 4.0 technologies, originally developed in the manufacturing sector, can be purposefully implemented to improve City Logistics (CL) processes by automatizing some of their operational tasks and enabling real-time exchange of information, with the ultimate goal of providing better interconnection among the actors involved. This work aims to identify the main social and economic contextual drivers for investing in the application of Industry 4.0 technologies to urban logistics. To this end, a dataset based on the primary collection of 105 CL projects exploiting the main 4.0 technologies has been built. After that, a regression model has been completed including potential economic, strategic, and demographic determinants of investments in CL 4.0. According to the obtained outcomes, Gross Domestic Product, Foreign Direct Investments, R&D Expenditure, Employment Rate, and Number of Inhabitants are significant contextual factors for the adoption of Industry 4.0 technologies in last mile logistics. The study might support academicians to investigate novel application fields of Industry 4.0 technologies. Also, it can serve as a roadmap for orienting the investments of private organizations and public entities to promote CL innovation and digitalization. Moreover, Industry 4.0 technology providers might find this study interesting to uncover prospective business sectors and markets. Future research efforts will analyse the impacts of internal business factors on CL 4.0 and the satisfaction levels of urban logistics stakeholders
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