A conspectus of and key to greek isoetes (Isoetaceae), based on a reassessment of haussknecht\u2019s gatherings of 1885

The three Isoetes species recorded from Thessalia (Thessaly) in N Greece by Haussknecht, in 1899, under the names I. setacea, I. heldreichii, and I. phrygia, were reassessed using megaspore and microspore ornamentation in addition to macromorphological features. \u201cIsoetes setacea\u201d is not the SW European I. delilei to which the name I. setacea was generally misapplied, nor \u201cI. echinospora\u201d as it has been called due to a misunderstanding, but a so far undescribed species here named I. haussknechtii; it has not been found again in Haussknecht\u2019s locality but has recently turned up in Peloponnisos and the E Aegean Islands. I. heldreichii, described from Haussknecht\u2019s gathering, is apparently extinct. The record of I. phrygia was based on misidentified I. gymnocarpa. Even so, contrary to prevailing opinion, Haussknecht was justified in raising Boissier\u2019s I. histrix var. phrygia to specific rank; genuine I. phrygia has recently been discovered in Kriti (Crete). The inventory of Greek Isoetes now comprises seven species, of which I. phrygia and I. todaroana are newly recorded here. Greek specimens studied are cited for all of them, and a key for their identification is presented. The names I. heldreichii and I. phrygia are typified

Independent tuning of acoustic and mechanical properties of phantoms for biomedical applications of ultrasound

In this work the preparation of tissue mimicking materials (TMMs) with independently tunable acoustic and elastic properties is reported. Although a large number of hydrogel, synthetic polymer, polysaccharides or other natural based materials have been proposed and used for the realization of TMMs, both for diagnostic and therapeutic applications of ultrasounds, up to today, simulation of acoustic properties was often performed using solid particles, reducing dramatically the transparency and inevitably affecting the homogeneity and the elastic properties of the TMM. By means of concentrated salts solutions and different polysaccharides, an easy method to prepare these TMMs have been developed. This approach would lead to obtain homogenous TMMs with Young modulus ranging over 3 orders of magnitude, i.e. from 2 to 1500 kPa, with independently tunable attenuation properties. An accurate mechanical and acoustic characterization of these TMMs have been performed. Finally, by means of a preliminary trials on protein denaturation induced by a high focused ultrasound transducer in a transparent TMMs with different attenuation values, the mechanism underlying on the formation and propagation of lesion has been investigated. Obtained results suggest that this 'chemical' approach would strongly support in vitro investigations on the open issues related to diagnostic and therapeutic application of ultrasounds

Nonlinear interplay of Alfven instabilities and energetic particles in tokamaks

The confinement of energetic particles (EP) is crucial for an efficient heating of tokamak plasmas. Plasma instabilities such as Alfven Eigenmodes (AE) can redistribute the EP population making the plasma heating less effective, and leading to additional loads on the walls. The nonlinear dynamics of toroidicity induced AE (TAE) is investigated by means of the global gyrokinetic particle-in-cell code ORB5, within the NEMORB project. The nonperturbative nonlinear interplay of TAEs and EP due to the wave-particle nonlinearity is studied. In particular, we focus on the nonlinear modification of the frequency, growth rate and radial structure of the TAE, depending on the evolution of the EP distribution in phase space. For the ITPA benchmark case, we find that the frequency increases when the growth rate decreases, and the mode shrinks radially. This nonlinear evolution is found to be correctly reproduced by means of a quasilinear model, namely a model where the linear effects of the nonlinearly modified EP distribution function are retained.Comment: Submitted to Plasma Phys. Control. Fusio

Aquatic Macrophytes Occurrence in Mediterranean Farm Ponds: Preliminary Investigations in North-Western Sicily (Italy)

Mediterranean wetlands are severely affected by habitat degradation and related loss of biodiversity. In this scenario, the wide number of artificial farm ponds can play a significant role in the biodiversity conservation of aquatic flora. In the present contribution we show the preliminary results of a study on Mediterranean farm ponds of north-western Sicily (Italy), aimed to investigating the environmental factors linked to the occurrence of submerged macrophytes (vascular plants and charophytes). We studied the aquatic flora of 30 ponds and determined the chemical and isotopic composition of their water bodies on a subset of the most representative 10 sites. Results show that (1) farm ponds host few but interesting species, such as Potamogeton pusillus considered threatened at regional level; (2) Chara vulgaris, C. globularis and P. pusillus behave as disturbance-tolerant species, occurring both in nitrates-poor and nitrates-rich waters, whereas Stuckenia pectinata and Zannichellia palustris occur only in nitrates-poor waters. Although farm ponds are artificial and relatively poor habitats, these environments seem to be important for the aquatic flora and for the conservation of the local biodiversity, and can give useful information for the use of macrophytes as ioindicators in the Mediterranean area

Charophytes for description and monitoring of inland waters in Sicily

The island of Sicily, in the center of the Mediterranean basin, is a well-known biodiversity hotspot (M\ue9dail & Qu\ue9zel, 1997). Unfortunately, the knowledge of its charophyte flora is absolutely unsatisfactory. The few available data derive from some scattered phytosociological works and some articles published more than 100 years ago. According to the last national synthesis (Bazzichelli & Abdelahad, 2009) a total of 19 Charophytes species should occur in the island, distributed in 4 genera: Chara L. (11), Nitella Agardh (5), Tolypella (A. Braun) A. Braun (2) and Lamprothamnium J. Groves (1). However an updated list of the species occurring in the island, together with their distributions, is currently lacking. It is noteworthy that, owing to this lack of local knowledge about charophytes, information currently available on these habitats occurring in the sites of the Natura 2000 network in Sicily is absolutely insufficient. We think that the group deserves a better knowledge, both for taxonomic, biogeographic and \u201cpure\u201d science, and for \u201capplied\u201d aspects connected with water quality and biodiversity conservation, also according to important European Directives (2000/60/CE and 92/43/EEC, respectively). So our work started, gathering data and making preliminary surveys. During the preliminary investigations, charophytes have been found in both freshwater and brackish waters, from 0 to 1400 m a.s.l. In particular, Chara vulgaris L. and Lamprothamnium papulosum (Wallr.) J. Groves have been identified in different coastal seasonally flooded habitats, referred to the priority habitat \u201c1150* coastal lagoons\u201d according to the mentioned 92/43 Directive. Chara contraria A. Braun ex K\ufctz. has been identified in springs and streams, referred to the habitat \u201c3140 Hard oligo-mesotrophic waters with benthic vegetation of Chara spp.\u201d. Other species have been found in other habitat types, such as the priority habitat \u201c3170* Mediterranean temporary ponds\u201d. M\ue9dail and Qu\ue9zel (1997). Annals of the Missouri Botanical Garden 84: 112 127. Bazzichelli and Abdelahad (2009). Flora analitica delle Caroficee. Sapienza Universit\ue0 di Roma - Ministero dell'Ambiente e della Tutela del Territorio e del Mare

Elliptic CMB Sky

The ellipticity of the anisotropy spots of the Cosmic Microwave Background measured by the Wilkinson Microwave Anisotropy Probe (WMAP) has been studied. We find an average ellipticity of about 2, confirming with a far larger statistics similar results found first for the COBE-DMR CMB maps, and then for the BOOMERanG CMB maps. There are no preferred directions for the obliquity of the anisotropy spots. The average ellipticity is independent of temperature threshold and is present on scales both smaller and larger than the horizon at the last scattering. The measured ellipticity characteristics are consistent with being the effect of geodesics mixing occurring in an hyperbolic Universe, and can mark the emergence of CMB ellipticity as a new observable constant describing the Universe. There is no way of simulating this effect. Therefore we cannot exclude that the observed behavior of the measured ellipticity can result from a trivial topology in the popular flat $\Lambda$-CDM model, or from a non-trivial topology.Comment: 10 pages, 5 figures, the version to appear in Mod.Phys.Lett.

Improved constraints on primordial non-Gaussianity for the Wilkinson Microwave Anisotropy Probe 5-yr data

We present new constraints on the non-linear coupling parameter fnl with the Wilkinson Microwave Anisotropy Probe (WMAP) data. We use an updated method based on the spherical Mexican hat wavelet (SMHW) which provides improved constraints on the fnl parameter. This paper is a continuation of a previous work by Curto et al. where several third order statistics based on the SMHW were considered. In this paper, we use all the possible third order statistics computed from the wavelet coefficient maps evaluated at 12 angular scales. The scales are logarithmically distributed from 6.9 arcmin to 500 arcmin. Our analysis indicates that fnl is constrained to -18 < fnl < +80 at 95% confidence level (CL) for the combined V+W WMAP map. This value has been corrected by the presence of undetected point sources, which adds a positive contribution of Delta_fnl = 6 +- 5. Our result excludes at ~99% CL the best-fitting value fnl=87 reported by Yadav & Wandelt. We have also constrained fnl for the Q, V and W frequency bands separately, finding compatibility with zero at 95 % CL for the Q and V bands but not for the W band. We have performed some further tests to understand the cause of this deviation which indicate that systematics associated to the W radiometers could be responsible for this result. Finally we have performed a Galactic North-South analysis for fnl. We have not found any asymmetry, i.e. the best-fitting fnl for the northern pixels is compatible with the best-fitting fnl for the southern pixels.Comment: 6 pages, 4 figures, 4 tables. Accepted for publication in Ap