The northernmost record of the blue-spotted cornetfish from the Mediterranean Sea

A school of Fistularia commersonii was sighted off Laigueglia (Italy), Northwestern Ligurian Sea, inAugust 2008. This fast spreading invasive Indo-Pacific fish was first recorded in the Mediterranean fromIsrael, and it has since spread clear across the sea. This is the northernmost record from the Mediterranean

Diurnal variation of phytoplankton production and solar radiation in coastal waters off Cananéia

O presente trabalho é uma primeira estimativa da produtividade primária na região de Cananéia. Tem por principal objetivo obter resultados preliminares sobre as variações diurnas da produção da população natural que vive nas águas costeiras, em função dos fatores ambientais. Com esta finalidade a maioria dos fatores que intervém na produtividade primária foram medidos e observados durante 2 dias, no período diurno em intervalo de 2 em 2 horas. Os principais fatores considerados na avaliação da produção primária foram: a - "Taxa de produção bruta" (gross production rate) dos organismos marinhos. b - Ambientes físico e químico. c - Relação entre a energia total incidente e a produção orgânica. O equipamento, os métodos e procedimentos empregados na obtenção dos resultados são apresentados. A produção orgânica foi determinada pela técnica do oxigênio de Gaarden & Gran (1927), a concentração de oxigênio foi medida pelo método de Winkler. O método empregado na dosagem da concentração de pigmentos foi o de Richards com Thompson (1952), Creitz & Richards (1955), Davis (1957) e o cômputo efetuado por meio das equações de Richards com Thompson. Os coeficientes de extinção foram obtidos pela observação do disco de Secchi e computados pela expressão de Poole & Atkins. A análise quantitativa do fitoplâncton foi efetuada pelo método de filtração "filtro milipóro" (millipore filter) e contagem microscópica de acordo com o "método de contagem de grupos" (clump count method). Os demais fatores foram obtidos através de medidas diretas ou por métodos usuais. A análise dos resultados e das observações permite as seguintes conclusões: A população fitoplanctônica natural que vive nas águas túrbidas costeiras da Ilha de Bom Abrigo foi encontrada em boas condições fisiológicas e é constituída principalmente por diatomáceas. s sais nutrientes (fosfatos) são encontrados em quantidades suficientes. A taxa máxima de produção orgânica é aproximadamente 93 mg C/m³/2 h na superfície de 131,25 mg C/m ³/2 h a 2,0 m de profundidade. A variação diurna da produção orgânica mostrou ser controlada principalmente pela variação diurna da intensidade de radiação solar global. A intensidade instantânea média saturante da radiação global é de 0.27 ly.min-i e a intensidade de iluminamento saturante varia entre 1.700 e 2.200 lúmen . pé-². A taxa média da produção orgânica para a energia saturante é aproximadamente de 22 mg C /mg de clorofila / 2 horas. Os resultados obtidos mostram ser compatíveis com os esperados para o "plâncton de sor' (sun plankton), que vive nas águas superficiais dos mares tropicais (Steemann Nielsen & Hansen, 1959)

Optical phase coherent timing of the Crab nebula pulsar with Iqueye at the ESO New Technology Telescope

The Crab nebula pulsar was observed in 2009 January and December with a novel very fast optical photon counter, Iqueye, mounted at the ESO 3.5 m New Technology Telescope. Thanks to the exquisite quality of the Iqueye data, we computed accurate phase coherent timing solutions for the two observing runs and over the entire year 2009. Our statistical uncertainty on the determination of the phase of the main pulse and the rotational period of the pulsar for short (a few days) time intervals are $\approx 1 \, \mu$s and ~0.5 ps, respectively. Comparison with the Jodrell Bank radio ephemerides shows that the optical pulse leads the radio one by ~240 $\mu$s in January and ~160 $\mu$s in December, in agreement with a number of other measurements performed after 1996. A third-order polynomial fit adequately describes the spin-down for the 2009 January plus December optical observations. The phase noise is consistent with being Gaussian distributed with a dispersion $\sigma$ of $\approx 15 \, \mu$s in most observations, in agreement with theoretical expectations for photon noise-induced phase variability.Comment: 10 pages, 5 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Societ

Septin Phosphorylation and Coiled-Coil Domains Function in Cell and Septin Ring Morphology in the Filamentous Fungus Ashbya Gossypii

Septins are a class of GTP-binding proteins conserved throughout many eukaryotes. Individual septin subunits associate with one another and assemble into heteromeric complexes that form filaments and higher-order structures in vivo. The mechanisms underlying the assembly and maintenance of higher-order structures in cells remain poorly understood. Septins in several organisms have been shown to be phosphorylated, although precisely how septin phosphorylation may be contributing to the formation of high-order septin structures is unknown. Four of the five septins expressed in the filamentous fungus, Ashbya gossypii, are phosphorylated, and we demonstrate here the diverse roles of these phosphorylation sites in septin ring formation and septin dynamics, as well as cell morphology and viability. Intriguingly, the alteration of specific sites in Cdc3p and Cdc11p leads to a complete loss of higher-order septin structures, implicating septin phosphorylation as a regulator of septin structure formation. Introducing phosphomimetic point mutations to specific sites in Cdc12p and Shs1p causes cell lethality, highlighting the importance of normal septin modification in overall cell function and health. In addition to discovering roles for phosphorylation, we also present diverse functions for conserved septin domains in the formation of septin higher-order structure. We previously showed the requirement for the Shs1p coiled-coil domain in limiting septin ring size and reveal here that, in contrast to Shs1p, the coiled-coil domains of Cdc11p and Cdc12p are required for septin ring formation. Our results as a whole reveal novel roles for septin phosphorylation and coiled-coil domains in regulating septin structure and function

The non-indigenous Paranthura japonica Richardson, 1909 in the Mediterranean Sea: travelling with shellfish?

An anthurid isopod new to the Mediterranean Sea has recently been observed in samples from three localities of the Italian coast: the Lagoon of Venice (North Adriatic Sea), La Spezia (Ligurian Sea) and Olbia (Sardinia, Tyrrhenian Sea). The specimens collected showed strong affinity to a species originally described from the NW Pacific Ocean: Paranthura japonica Richardson, 1909. The comparison with specimens collected from the Bay of Arcachon (Atlantic coast of France), where P. japonica had been recently reported as non-indigenous, confirmed the identity of the species. This paper reports the most relevant morphological details of the Italian specimens, data on the current distribution of the species and a discussion on the pathways responsible for its introduction. The available data suggest that the presence of this Pacific isopod in several regions of coastal Europe might be due to a series of aquaculture-mediated introduction events that occurred during the last decades of the 1900s. Since then, established populations of P. japonica, probably misidentified, remained unnoticed for a long time

QuantEYE: The Quantum Optics Instrument for OWL

QuantEYE is designed to be the highest time-resolution instrument on ESO:s planned Overwhelmingly Large Telescope, devised to explore astrophysical variability on microsecond and nanosecond scales, down to the quantum-optical limit. Expected phenomena include instabilities of photon-gas bubbles in accretion flows, p-mode oscillations in neutron stars, and quantum-optical photon bunching in time. Precise timescales are both variable and unknown, and studies must be of photon-stream statistics, e.g., their power spectra or autocorrelations. Such functions increase with the square of the intensity, implying an enormously increased sensitivity at the largest telescopes. QuantEYE covers the optical, and its design involves an array of photon-counting avalanche-diode detectors, each viewing one segment of the OWL entrance pupil. QuantEYE will work already with a partially filled OWL main mirror, and also without [full] adaptive optics.Comment: 7 pages; Proceedings from meeting 'Instrumentation for Extremely Large Telescopes', held at Ringberg Castle, July 2005 (T.Herbst, ed.