224 research outputs found

    Boundary Spatiotemporal Correlations in a Self-Organized Critical Model of Punctuated Equilibrium

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    In a semi-infinite geometry, a 1D, M-component model of biological evolution realizes microscopically an inhomogeneous branching process for M→∞M \to \infty. This implies in particular a size distribution exponent τ′=7/4\tau'=7/4 for avalanches starting at a free end of the evolutionary chain. A bulk--like behavior with τ′=3/2\tau'=3/2 is restored if `conservative' boundary conditions strictly fix to its critical, bulk value the average number of species directly involved in an evolutionary avalanche by the mutating species located at the chain end. A two-site correlation function exponent τR′=4{\tau_R}'=4 is also calculated exactly in the `dissipative' case, when one of the points is at the border. These results, together with accurate numerical determinations of the time recurrence exponent τfirst′\tau_{first}', show also that, no matter whether dissipation is present or not, boundary avalanches have the same space and time fractal dimensions as in the bulk, and their distribution exponents obey the basic scaling laws holding there.Comment: 5 pages, 3 eps figure

    Superconducting properties of mesoscopic cylinders with enhanced surface superconductivity

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    The superconducting state of an infinitely long superconducting cylinder surrounded by a medium which enhances its superconductivity near the boundary is studied within the nonlinear Ginzburg-Landau theory. This enhancement can be due to the proximity of another superconductor or due to surface treatment. Quantities like the free energy, the magnetization and the Cooper-pair density are calculated. Phase diagrams are obtained to investigate how the critical field and the critical temperature depend on this surface enhancement for different values of the Ginzburg-Landau parameter \kappa. Increasing the superconductivity near the surface leads to higher critical fields and critical temperatures. For small cylinder diameters only giant vortex states nucleate, while for larger cylinders multivortices can nucleate. The stability of these multivortex states also depends on the surface enhancement. For type-I superconductors we found the remarkable result that for a range of values of the surface extrapolation length the superconductor can transit from the Meissner state into superconducting states with vorticity L > 1. Such a behaviour is not found for the case of large \kappa, i.e. type-II superconductivity.Comment: submitted to Phys. Rev.

    Physico-chemical and sensory characterization of a fruit beer obtained with the addition of cv. Lambrusco grapes must

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    In 2015, Italian Grape Ale (IGA) beers have been included as a new provisional sub-category of special-type fruit beers by the Beer Judge Certification Program, including those products whose brewing process is carried out in presence of determined quantities of grape must. However, information on the effects of these additions on the composition of final beers are still scarce. This work is hence focused on the chromatic, volatile, phenolic and sensory characterization of IGA beers obtained with the addition of grape musts during brewing process. To this aim, different amounts of must (5, 10 and 20%) from cv. Lambrusco red grapes were added to a lager wort before primary fermentation. Beers were then characterized by HPLC-MS, GC-MS and sensory analysis in order to determine phenolic and aroma compounds along with their sensory attributes. Results confirmed the addition of must from cv. Lambrusco grapes capable to enrich beers in color, acids, phenolic (up to 7-folded increased) and volatile compounds, while giving complexity to beers. These results, which were confirmed by a trained sensory panel, are among the very first insights on the impact of red grape must in brewing, both from a compositional and sensory point of view

    Management of idiopathic epistaxis in adults: what's new? [Il trattamento dell’epistassi idiopatica nell’adulto: cosa c’è di nuovo?]

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    L’epistassi è uno dei disturbi più comuni per il quale il paziente si rivolge spesso al pronto soccorso. Questa revisione della letteratura sipropone di valutare sistematicamente e criticamente gli studi scientifici riguardo il trattamento dell’epistassi idiopatica al fine di ottenere utili spunti per la pratica clinica. La ricerca è stata eseguita nei database elettronici: PubMed, Embase, Cochrane e Central. I criteri di inclusione sono stati: studi clinici controllati retrospettivi o prospettici o randomizzati o studi su modelli animali che includevano i risultati nella gestione dell’epistassi idiopatica. Sono stati individuati 23 articoli che soddisfano i criteri di inclusione. Il tamponamento nasale rappresenta ancora l’approccio di prima linea all’epistassi, anche se è evidente dalla letteratura che sia il meno efficace ma il più associato a ricoveri ospedalieri di maggior durata rispetto alla chirurgia endoscopica basata sull’elettrocoagulazione. In conclusione appare sempre più evidente che la cauterizzazione dovrebbe essere l’approccio di prima linea per l’alto tasso di costo-efficacia e il basso rischio di complicanze. Tuttavia, ulteriori ricerche urgenti sono necessarie per validare l’efficacia dei nuovi biomateriali nel trattamento dell’epistassi.Epistaxis is one of the most common complaints presenting to emergency departments. The aim of this study is to systematically review and critically evaluate the evidence relating to treatment of idiopathic epistaxis for guiding best practice. A comprehensive review of the English language literature was performed using PubMed, Embase, Cochrane Library and Central electronic databases. The inclusion criteria were: retrospective or prospective or randomised controlled clinical trials which included outcomes in the management of idiopathic epistaxis. Twentythree articles met inclusion criteria and were reviewed. Nasal packing still represents the first-line approach to epistaxis, although, at present, it appears that there is clear evidence in the literature to suggest that it is less effective and associated with more admissions and longer hospital stays than endoscopic electrocoagulation-based management of epistaxis. In conclusion, cauterisation should be the first-line approach for its high cost-effectiveness rate and low risk of complications. Further research is urgently needed to assess the efficacy of new biomaterials

    Physico-chemical and sensory characterization of a fruit beer obtained with the addition of cv. Lambrusco grapes must

    Get PDF
    In 2015, Italian Grape Ale (IGA) beers have been included as a new provisional sub-category of special-type fruit beers by the Beer Judge Certification Program, including those products whose brewing process is carried out in presence of determined quantities of grape must. However, information on the effects of these additions on the composition of final beers are still scarce. This work is hence focused on the chromatic, volatile, phenolic and sensory characterization of IGA beers obtained with the addition of grape musts during brewing process. To this aim, different amounts of must (5, 10 and 20%) from cv. Lambrusco red grapes were added to a lager wort before primary fermentation. Beers were then characterized by HPLC-MS, GC-MS and sensory analysis in order to determine phenolic and aroma compounds along with their sensory attributes. Results confirmed the addition of must from cv. Lambrusco grapes capable to enrich beers in color, acids, phenolic (up to 7-folded increased) and volatile compounds, while giving complexity to beers. These results, which were confirmed by a trained sensory panel, are among the very first insights on the impact of red grape must in brewing, both from a compositional and sensory point of view

    Seasonal variability of the HO.RE.CA. food leftovers employed as a feeding substrate for black soldier fly (Hermetia illucens L.) larvae and effects on the rearing performance

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    The SCALIBUR project (Horizon, 2020) aimed to explore innovative solutions, including the use of black soldier fly larvae, for the bio-urban waste management. This research work describes the evaluation of the variability in water, proteins, fat, ashes, and carbohydrates present in the HO.RE.CA. food leftovers which were withdrawn from a local canteen over a 12-month period and the relationship with (i) the growth parameters of the larvae, (ii) the percentage of substrate reduction and the percentage of frass separated through the mechanical sieve at the end of the rearing process. HO.RE.CA. food leftovers are overall a suitable feeding substrate for larval rearing. Water contained in the HO.RE.CA. food leftovers was sufficient for larval rearing without resorting to further addition. As for water content, a seasonal trend was not observed, on the contrary, it was proved to be totally random. However, high amount of water (>80%) was correlated with higher larval mortality rate. The larval weight was significantly correlated to the amount of protein (r = 0.80; p ≤ 0.001) present in the substrate, and to a lesser extent to the amount of fat (r = 0.43; p ≤ 0.05). The feed conversion rate and bioconversion rate were both in agreement with literature data. The statistical test did not show any significant correlation between the amount of water contained in the initial fresh HO.RE.CA. food leftovers and the percentage of substrate reduction and the percentage of frass separated through the mechanical sieve at the end of the rearing process

    Trans-oral robotic surgery for the management of oropharyngeal carcinomas: A 9-year institutional experience

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    Trans-oral robotic surgery (TORS) has changed surgical management of patients with oropharyngeal squamous cell carcinomas (OPSCC). In this study we present surgical and oncologic outcomes of patients with oropharyngeal squamous cell carcinomas, treated using TORS, with and without an adjuvant therapy. Sixty patients with oropharyngeal squamous cell carcinomas treated with TORS between January 2008 and December 2017 have been retrospectively evaluated considering clinicopathologic features, disease characteristics, adjuvant treatments and oncological outcomes. TORS was performed for OPSCC to the base of tongue in 41.7%, tonsils in 46.7%, soft palate and posterior pharyngeal wall in 3.3% and 5%, respectively. Neck dissection was performed in 43.3% of patients. Management strategies included surgery alone in 30%, TORS and adjuvant radiotherapy in 33.3%, and TORS plus adjuvant chemotherapy in 36.7%. The 5-year overall survival of the total group was 77.6%, the 5-year disease-free survival rate was 85.2%, and the 5-year local recurrence-free survival rate was 90.6%. Finally, in selected patients TORS appears to yield similar oncologic outcomes and functional outcomes to traditional techniques and non-operative treatment with a possible benefit on long-term quality of life. The future offers exciting opportunities to combine TORS and radiotherapy in unique ways. However, further research is urgently needed to clarify the indications for adjuvant therapy following TORS resections

    Palatal surgery in a transoral robotic setting (TORS): preliminary results of a retrospective comparison between uvulopalatopharyngoplasty (UPPP), expansion sphincter pharyngoplasty (ESP) and barbed repositioning pharyngoplasty (BRP)

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    Negli ultimi anni si è diffusa lopinione che la chirurgia multilivello nel trattamento della sindrome delle apnee ostruttive garantisca risultati pià soddisfacenti. Lobiettivo del nostro lavoro è quello di confrontare tre tecniche palatali associate alla TORS: luvulopalatofaringoplastica (UPPP), lexpansion sphincter pharyngoplasy (ESP) e la barbed repositioning pharingoplasty (BRP). Trenta pazienti, trattati con TORS, tonsillectomia e settoturbinoplastica e chirurgia palatale sono stati retrospettivamente studiati. I seguenti valori pre e post-operatori sono stati presi in considerazione: AHI, ESS, VAS per la valutazione del dolore, tempi operatori palatali, data di dimissione e complicanze (tipi ed incidenza). Sia la BRP che lESP hanno garantito dei valori postoperatorio di AHI inferiori rispetto allUPPP con un maggior tasso di successo chirurgico. Dallaltra parte non è stato possibile dimostrare una superiorità della BRP sullESP. I tempi operatori più lunghi sono stati registrati nel gruppo ESP mentre i più brevi sono stati riscontrati nel gruppo BRP. Riassumendo, ESP e BRP sono risultate più efficaci dellUPPP in un setting robotico multilivello. Inoltre, essendo una tecnica rapida, di facile apprendimento e dal basso tasso di complicanze, la BRP si presenta come una valida opzione chirurgica nel trattamento dellOSAS

    Effects of confinement and surface enhancement on superconductivity

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    Within the Ginzburg-Landau approach a theoretical study is performed of the effects of confinement on the transition to superconductivity for type-I and type-II materials with surface enhancement. The superconducting order parameter is characterized by a negative surface extrapolation length bb. This leads to an increase of the critical field Hc3H_{c3} and to a surface critical temperature in zero field, TcsT_{cs}, which exceeds the bulk TcT_c. When the sample is {\em mesoscopic} of linear size LL the surface induces superconductivity in the interior for TTcsT T_{cs}. In analogy with adsorbed fluids, superconductivity in thin films of type-I materials is akin to {\em capillary condensation} and competes with the interface delocalization or "wetting" transition. The finite-size scaling properties of capillary condensation in superconductors are scrutinized in the limit that the ratio of magnetic penetration depth to superconducting coherence length, κ≡λ/ξ\kappa \equiv \lambda/\xi , goes to zero, using analytic calculations. While standard finite-size scaling holds for the transition in non-zero magnetic field HH, an anomalous critical-point shift is found for H=0. The increase of TcT_c for H=0 is calculated for mesoscopic films, cylindrical wires, and spherical grains of type-I and type-II materials. Surface curvature is shown to induce a significant increase of TcT_c, characterized by a shift Tc(R)−Tc(∞)T_c(R)-T_c(\infty) inversely proportional to the radius RR.Comment: 37 pages, 5 figures, accepted for PR

    Phenomenological theory of the 3 Kelvin phase in Sr2RuO4

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    We model the 3K-phase of Sr2RuO4 with Ru-metal inclusion as interface state with locally enhanced transition temperatures. The resulting 3K-phase must have a different pairing symmetry than the bulk phase of Sr2RuO4, because the symmetry at the interface is lower than in the bulk. It is invariant under time reversal and a second transition, in general, above the onset of bulk superconductivity is expected where time reversal symmetry is broken. The nucleation of the 3K-phase exhibits a ``capillary effect'' which can lead to frustration phenomena for the superconducting states on different Ru-inclusions. Furthermore, the phase structure of the pair wave function gives rise to zero-energy quasiparticle states which would be visible in quasiparticle tunneling spectra. Additional characteristic properties are associated with the upper critical field Hc2. The 3K-phase has a weaker anisotropy of Hc2 between the inplane and z-axis orientation than the bulk superconducting phase. This is connected with the more isotropic nature Ru-metal which yields a stronger orbital depairing effect for the inplane magnetic field than in the strongly layered Sr$_2RuO4. An anomalous temperature dependence for the z-axis critical field is found due to the coupling of the magnetic field to the order parameter texture at the interface. Various other experiments are discussed and new measurements are suggested.Comment: 10 pages, 5 figure
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