A new physeteroid cetacean from the Lower Miocene of southern Italy: CT imaging, retrodeformation, systematics and palaeobiology of a sperm whale from the Pietra leccese

Herein we describe a new finding of a medium-sized sperm whale from the Burdigalian (Lower Miocene) of the Pietra leccese formation (southern Italy) on the basis of a partly prepared specimen that includes a partial cranium, seven detached teeth, the fragmentary right mandible and two partial vertebral bodies. Because of the overall compression of the specimen, we carried out a retro deformation of a 3D model of the cranium obtained via CT-scanning. The combined analysis of the original specimen and the retrodeformed model has allowed us to recognise that the studied specimen constitutes a new physeteroid taxon: Angelocetus cursiensis n. gen. n. sp., a longirostrine sperm whale characterised by a sideward projected supracranial basin, as evidenced by the overall displacement of its posteriormost margin. Based on a phylogenetic analysis, A. cursiensis n. gen. n. sp. is determined to be a crown physeteroid that does not belong to either the Physeteridae or the Kogiidae. The wide temporal fossa, elongated rostrum and slender teeth, as well as the skull dimensions (estimated bizygomatic width c. 550 mm) suggest a diet based on medium to large-sized bony fish that were likely captured by a raptorial pierce feeding strategy (as for most of the coeval Burdigalian physeteroids). Despite a seemingly low ecomorphological disparity, the high degree of taxonomic diversity of the Burdigalian physeteroids suggests that this time span represents a crucial phase for the evolutionary history of sperm whales

Age and Depositional Environment of Whale-Bearing Sedimentary Succession from the Lower Pliocene of Tuscany (Italy): Insights from Palaeomagnetism, Calcareous Microfossils and Facies Analyses

A c. 31 m thick section straddling the fossil find of an Early Pliocene baleen whale ("Brunella", hereafter), made in 2007 in the sedimentary fill of the Middle Ombrone Basin of Tuscany, is investigated for depositional age and environment combining palaeomagnetic, micropalaeontological (Foraminifera and calcareous nannofossils) and sedimentary facies analyses. Resting unconformably onto Late Miocene continental deposits, the Early Pliocene marine deposits include, from bottom to top, a coarse-grained wave-winnowing lag, the few metres-thick fossiliferous sandstone bedset from which Brunella was unearthed, and several metres of clays. The stratigraphic organisation of these deposits indicate deposition in a deepening upward inner shelf environment. Successful isolation of characteristic remanent magnetisation and calcareous nannofossil content indicate the investigated marine section was deposited during the interval of polarity Chron C3n.2n corresponding to the basal part of the Mediterranean nannofossil zone MNN13 (between Helicosphaera sellii Base common and the Amaurolithus primus Top) and allow estimating the depositional age of Brunella to c. 4.6 Ma. Sedimentary facies, benthic Foraminifera association and anisotropy of magnetic susceptibility characterising the deposits that embedded Brunella suggest deposition above the fair-weather base level

Toward an Astrochronology-Based Age-Model for a Messinian Pre-Evaporitic Succession: The Example of Torrente Vaccarizzo Section in Sicily (Italy)

Tectonic, paleoenvironmental, and paleoclimatic unstable conditions preceding the onset of the Messinian Salinity Crisis (MSC) highly affected marine life. Changes in calcareous plankton association are overall registered in the Mediterranean. They consist of a general transition from abundant and well-diversified planktonic associations to strictly oligotypic assemblages that precede their total disappearance at the onset of evaporitic precipitation. In this work, an accurate quantitative analysis of calcareous plankton, both foraminifers and nannofossils, has been carried out in the Torrente Vaccarizzo Section of Sicily (southern Italy). The aim is to independently define a chronostratigraphic pattern of bioevents preceding the MSC in the absence of magnetostratigraphic or radiometric constraints. The fluctuating abundance of the genus Orbulina fits well with the 100 ky Eccentricity maxima, and it is successfully applied to build an astronomically calibrated age-model for the section. On this basis, all the biohorizons have been recalibrated and discussed with regard to the previous literature. Abundant influxes of selected species demonstrated to be of local significance since they are highly affected by paleoenvironmental and paleoclimatic conditions. A chronological sequence of foraminifer and nannofossil events marks the onset of the MSC with a derived age of 5.957 My, which agrees well with previous findings from other Mediterranean sections. This methodology and the new biostratigraphic events may be useful for future studies on pre-evaporitic successions of the Mediterranean

Terahertz All-Optical Modulation in a Silicon-Polymer Hybrid System

Although Gigahertz-scale free-carrier modulators have been previously demonstrated in silicon, intensity modulators operating at Terahertz speeds have not been reported because of silicon's weak ultrafast optical nonlinearity. We have demonstrated intensity modulation of light with light in a silicon-polymer integrated waveguide device, based on the all-optical Kerr effect - the same ultrafast effect used in four-wave mixing. Direct measurements of time-domain intensity modulation are made at speeds of 10 GHz. We showed experimentally that the ultrafast mechanism of this modulation functions at the optical frequency through spectral measurements, and that intensity modulation at frequencies in excess of 1 THz can be obtained in this device. By integrating optical polymers through evanescent coupling to high-mode-confinement silicon waveguides, we greatly increase the effective nonlinearity of the waveguide for cross-phase modulation. The combination of high mode confinement, multiple integrated optical components, and high nonlinearities produces all-optical ultrafast devices operating at continuous-wave power levels compatible with telecommunication systems. Although far from commercial radio frequency optical modulator standards in terms of extinction, these devices are a first step in development of large-scale integrated ultrafast optical logic in silicon, and are two orders of magnitude faster than previously reported silicon devices.Comment: Under consideration at Nature Material

Effects of controlled diesel exhaust exposure on apoptosis and proliferation markers in bronchial epithelium – an in vivo bronchoscopy study on asthmatics, rhinitics and healthy subjects

BackgroundEpidemiological evidence demonstrates that exposure to traffic-derived pollution worsens respiratory symptoms in asthmatics, but controlled human exposure studies have failed to provide a mechanism for this effect. Here we investigated whether diesel exhaust (DE) would induce apoptosis or proliferation in the bronchial epithelium in vivo and thus contribute to respiratory symptoms.MethodsModerate (n?=?16) and mild (n?=?16) asthmatics, atopic non-asthmatic controls (rhinitics) (n?=?13) and healthy controls (n?=?21) were exposed to filtered air or DE (100 ?g/m 3 ) for 2 h, on two separate occasions. Bronchial biopsies were taken 18 h post-exposure and immunohistochemically analysed for pro-apoptotic and anti-apoptotic proteins (Bad, Bak, p85 PARP, Fas, Bcl-2) and a marker of proliferation (Ki67). Positive staining was assessed within the epithelium using computerized image analysis.ResultsNo evidence of epithelial apoptosis or proliferation was observed in healthy, allergic or asthmatic airways following DE challenge.ConclusionIn the present study, we investigated whether DE exposure would affect markers of proliferation and apoptosis in the bronchial epithelium of asthmatics, rhinitics and healthy controls, providing a mechanistic basis for the reported increased airway sensitivity in asthmatics to air pollutants. In this first in vivo exposure investigation, we found no evidence of diesel exhaust-induced effects on these processes in the subject groups investigated

Transcriptome sequencing of three Pseudo-nitzschia species reveals comparable gene sets and the presence of Nitric Oxide Synthase genes in diatoms

Diatoms are among the most diverse eukaryotic microorganisms on Earth, they are responsible for a large fraction of primary production in the oceans and can be found in different habitats. Pseudo-nitzschia are marine planktonic diatoms responsible for blooms in coastal and oceanic waters. We analyzed the transcriptome of three species, Pseudo-nitzschia arenysensis, Pseudo-nitzschia delicatissima and Pseudo-nitzschia multistriata, with different levels of genetic relatedness. These species have a worldwide distribution and the last one produces the neurotoxin domoic acid. We were able to annotate about 80% of the sequences in each transcriptome and the analysis of the relative functional annotations allowed comparison of the main metabolic pathways, pathways involved in the biosynthesis of isoprenoids (MAV and MEP pathways), and pathways putatively involved in domoic acid synthesis. The search for homologous transcripts among the target species and other congeneric species resulted in the discovery of a sequence annotated as Nitric Oxide Synthase (NOS), found uniquely in Pseudo-nitzschia multistriata. The predicted protein product contained all the domains of the canonical metazoan sequence. Putative NOS sequences were found in other available diatom datasets, supporting a role for nitric oxide as signaling molecule in this group of microalgae

Photonic band gaps in materials with triply periodic surfaces and related tubular structures

We calculate the photonic band gap of triply periodic bicontinuous cubic structures and of tubular structures constructed from the skeletal graphs of triply periodic minimal surfaces. The effect of the symmetry and topology of the periodic dielectric structures on the existence and the characteristics of the gaps is discussed. We find that the C(I2-Y**) structure with Ia3d symmetry, a symmetry which is often seen in experimentally realized bicontinuous structures, has a photonic band gap with interesting characteristics. For a dielectric contrast of 11.9 the largest gap is approximately 20% for a volume fraction of the high dielectric material of 25%. The midgap frequency is a factor of 1.5 higher than the one for the (tubular) D and G structures