Search results for "Cave"

Multiple nodal solutions for semilinear robin problems with indefinite linear part and concave terms

2017

We consider a semilinear Robin problem driven by Laplacian plus an indefinite and unbounded potential. The reaction function contains a concave term and a perturbation of arbitrary growth. Using a variant of the symmetric mountain pass theorem, we show the existence of smooth nodal solutions which converge to zero in $C^1(\overline{\Omega})$. If the coefficient of the concave term is sign changing, then again we produce a sequence of smooth solutions converging to zero in $C^1(\overline{\Omega})$, but we cannot claim that they are nodal.

The putative sponge aggregation receptor. Isolation and characterization of a molecule composed of scavenger receptor cysteine-rich domains and short…

1998

Porifera (sponges) are the oldest extant metazoan phylum. Dissociated sponge cells serve as a classic system to study processes of cell reaggregation. The reaggregation of dissociated cells is mediated by an extracellularly localized aggregation factor (AF), based on heterophilic interactions of the third order; the AF bridges two cells by ligating a cell-surface-bound aggregation receptor (AR). In the present study we report cloning, expression and immunohistochemical localization of a polypeptide from the marine sponge Geodia cydonium, which very likely represents the AR. The presumed AR gene gives rise to at least three forms of alternatively spliced transcripts of 6.5, 4.9 and 3.9 kb, a…

Evaluating the Effects of the Rill Longitudinal Profile on Flow Resistance Law

2022

In this paper, for the first time, the effect of the longitudinal profile shape of the rill (uniform, concave, and convex) on flow resistance law was studied. The first part of the paper is based on a theoretical equation to estimate the Darcy–Weisbach friction factor f, deduced from the power velocity distribution and rill measurements performed on a plot. At first, the equation to estimate the Γ parameter of the velocity profile was calibrated using all available measurements. Then an analysis of the hydraulic characteristics at reach scale, for comparable values of discharge, was carried out, comparing the different profile shapes. To assess the influence of the rill profile …

Zr, Hf and REE distribution in river water under different ionic strength conditions

2018

International audience; The Platani River flowing in south-central Sicily, interacting with evaporite rocks, generates a wide range of ionic strength in the water catchment from 0.1 to 5.0 mol kg−1. We sampled 38 river sites and analysed the composition for the dissolved fraction filtered through 0.45 μm, the truly dissolved fraction obtained through ultrafiltration (10 kDa) and the relative included colloidal fraction.This study was focused on the recognition of Zr, Hf and REE behaviour under changing ionic strength conditions, since this is one of parameters responsible for colloid stability in natural waters. In turn, this phenomenon leads to REE release from the colloidal fraction and t…

UTILIZZO DEL SILDENAFIL CITRATO NELLA PREVENZIONE DEI CORPI CAVERNOSI NELLA IPP E NELL' INVECCHIAMENTO

2011

Free radical scavenging abilities of flavonoids as mechanism of protection against mutagenicity induced by tert-butyl hydroperoxide or cumene hydrope…

2003

Mutagenicity induced by tert-butyl hydroperoxide (BHP) or cumene hydroperoxide (CHP) in Salmonella typhimurium TA102 was effectively reduced by flavonols with 3',4'-hydroxyl groups such as fisetin, quercetin, rutin, isoquercitrin, hyperoxide, myricetin, myricitrin, robinetin, and to a lesser extent also by morin and kaempferol (ID50=0.25-1.05 micromol per plate). With the exception of isorhamnetin, rhamnetin, morin, and kaempferol, closely similar results were obtained with both peroxides. Hydrogenation of the double bond between carbons 2 and 3 (dihydroquercetin, dihydrorobinetin) as well as the additional elimination of the carbonyl function at carbon 4 (catechins) resulted in a loss of a…

Antropologia filosòfica i literatura (II): TH. W. Adorno i S. Cavell interpreten Fi de partida de S. Beckett

2006

Abstract: This paper is a philosophical reading of Samuel Beckettʼs Endgame, taking into account many of the critic suggestions of Adornoʼs interpretation, from his negative dialectics in the note Versuch, das Endspiel zu verstehen. It deals as well with the acute comments by Stanley Cavell in the chapter V of his book "Must We Mean What We Say?", a view from the philosophy of the ordinary language on this play of the Irish writer. In doing so this paper tries to commemorate the centenary of Beckettʼs birth and claims for the necessary study of the relationships between philosophical anthropology and literature in our present.

L’ENCEINTE NÉOLITHIQUE DE CRAVANT HAUT DE BRÉVIANDE, COMMUNE DE DEUX-RIVIÈRES (YONNE)et la séquence chronologique du début du Néolithique autour de l…

2022

Die von J.-P. Delor anhand von Luftaufnahmen identifizierte Einhegung von Deux-Rivières (Cravant) war 1999 Gegenstand einer kurzen Sondierungskampagne. Sie ist von einer Palissade und möglicherweise einem Graben oder einer zweiten Palisade umgeben und umgrenzt ein ca. 1,5 ha großes Areal. Sie wurde durch den Bau der Rollbahn eines Militärflughafens, bei dem der Innenbereich teilweise abgetragen wurde, stark beschädigt. Das Fundmaterial gestattet keine genauere Datierung. Die seltenen Indizien legen eine Zuordnung zu der in der Region gut vertretenen Cerny-Kultur nahe. Der vorliegende Artikel bietet die Gelegenheit, eine Aktualisierung der chronologischen Sequenz des Sektors Yonne-Cure im 5.…

Submerged speleothems and sea level reconstructions: a global overview and new results from the Mediterranean Sea

2021

This study presents a global overview of the submerged speleothems used to reconstruct paleo sea levels and reports new results from two stalactites collected in the Mediterranean Sea. Coastal cave deposits significantly contributed to the understanding of global and regional sea-level variations during the Middle and Late Quaternary. The studied speleothems cover the last 1.4 Myr and focused mainly on Marine Isotope Stages (MIS) 1, 2, 3, 5.1, 5.3, 5.5, 7.1, 7.2, 7.3 and 7.5. The results indicate that submerged speleothems represent extraordinary archives that can provide detailed information on former sea-level changes. The two stalactites collected in the central Mediterranean Sea, at Fa…

A Taphonomic Perspective on Neolithic Beginnings: Theory, Interpretation, and Empirical Data in the Western Mediterranean

2001

The fills of caves and rockshelters generally comprise complex depositional palimpsests, making fine scale chronological resolution extremely difficult. Nevertheless, these settings remain very important in archaeology because they often preserve long records of cultural change. This is true for the initial appearance of food producing economies in the western Mediterranean. The chronologically ambiguous nature of cave and shelter deposits is one of the reasons for the continued debate over the processes responsible for the beginning of the Neolithic in this region. We employ taphonomic studies of the archeofaunal record from Mesolithic and early Neolithic cave and shelter sites in Mediterr…