A new species of Isodictya (Porifera: Poecilosclerida) from the Southern Ocean

We discovered a new species of Porifera belonging to the genus Isodictya Bowerbank, 1864 during cruises aboard R/V Hesperides in Antarctica. Collected samples are mostly part of the surveys of the Spanish project BENTART whose main objective has been to study the benthic communities inhabiting sea bottoms of Livingston and Deception Island in the South Shetlands archipelago and the Antarctic Peninsula. Isodictya filiformis sp. nov., described here, is characterized by its fragile and thin morphology (very different from other known species in the area) and by having microxeas as additional microscleres. Three specimens were collected from Marguerite Bay, Low Island and Deception Island (Antarctic Peninsula) and one specimen at Peter I Island (Bellingshausen Sea). Its presence in Peter Island is quite relevant as this location is 390 km away from the nearest coast in the Bellingshausen Sea, an area that has scarcely been investigated in the past. However, results from the Bentart 03 Expedition seem to indicate that Peter I Island has a wide variety of benthic organisms, in contrast to the deep adjacent areas of Bellingshausen Sea. Apart from the morphological analyses, we place the new Isodictya species within its phylogenetic context using two nuclear markers (18S rDNA and 28S rDNA) and provide some information about the ecological preferences of the new speciesPostprint1,44

Evolutionary origins of sensation in metazoans: functional evidence for a new sensory organ in sponges

Background: One of the hallmarks of multicellular organisms is the ability of their cells to trigger responses to the environment in a coordinated manner. In recent years primary cilia have been shown to be present as 'antennae' on almost all animal cells, and are involved in cell-to-cell signaling in development and tissue homeostasis; how this sophisticated sensory system arose has been little-studied and its evolution is key to understanding how sensation arose in the Animal Kingdom. Sponges (Porifera), one of the earliest evolving phyla, lack conventional muscles and nerves and yet sense and respond to changes in their fluid environment. Here we demonstrate the presence of non-motile cilia in sponges and studied their role as flow sensors. Results: Demosponges excrete wastes from their body with a stereotypic series of whole-body contractions using a structure called the osculum to regulate the water-flow through the body. In this study we show that short cilia line the inner epithelium of the sponge osculum. Ultrastructure of the cilia shows an absence of a central pair of microtubules and high speed imaging shows they are non-motile, suggesting they are not involved in generating flow. In other animals non-motile, 'primary', cilia are involved in sensation. Here we show that molecules known to block cationic ion channels in primary cilia and which inhibit sensory function in other organisms reduce or eliminate sponge contractions. Removal of the cilia using chloral hydrate, or removal of the whole osculum, also stops the contractions; in all instances the effect is reversible, suggesting that the cilia are involved in sensation. An analysis of sponge transcriptomes shows the presence of several transient receptor potential (TRP) channels including PKD channels known to be involved in sensing changes in flow in other animals. Together these data suggest that cilia in sponge oscula are involved in flow sensation and coordination of simple behaviour. Conclusions: This is the first evidence of arrays of non-motile cilia in sponge oscula. Our findings provide support for the hypothesis that the cilia are sensory, and if true, the osculum may be considered a sensory organ that is used to coordinate whole animal responses in sponges. Arrays of primary cilia like these could represent the first step in the evolution of sensory and coordination systems in metazoans. © 2014 Ludeman et al.; licensee BioMed Central Ltd

Characterization and modeling of link loss for an outdoor free-space optics transmission system

In this paper we propose three low-complexity algorithms to estimate the time-varying loss of an outdoor 1550-nm free-space optics (FSO) link with 55-m transmission length. Longterm experimental measurements taken for different weather conditions demonstrate that the link loss can be predicted accurately while still using low-complexity algorithms

Hematoma epidural cervical tras latigazo cervical

Se describe un hematoma epidural a nivel cervical en un varón de 43 años, tras un traumatismo menor tipo latigazo cervical. Su sintomatología inicial obligó a descartar patología cardiaca llegándose al diagnóstico tras estudio mediante resonancia nuclear magnética. El cuadro clínico parcial y no progresivo desaconsejó la cirugía, observándose su reabsorción con nuevo control de resonancia. Se realza una revisión de la bibliografía, señalándose las principales características de esta entidad poco frecuente.We repor a case of cervical epidural hematoma in a 43 year-old man, after soft-tissue cervical spine strain (known as a “whiplast”). At the beginnig, because previous presumptive cardiac pain in this patient, we need to discart cardiac cause. We made the diagnostic of cervical epidural hematoma with the use of magnetic resonance imaging. The incomplete, not severe and nonprogressing defficits led us to conservative treatment; and the hematoma resolved spontaneously, as documented with a new magnetic resonance imaging. The medical literature relating to this uncommon entity has been reviewe

Some Like It Fat: Comparative Ultrastructure of the Embryo in Two Demosponges of the Genus Mycale (Order Poecilosclerida) from Antarctica and the Caribbean

0000-0002-7993-1523© 2015 Riesgo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License [4.0], which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article

Adaptive probabilistic shaped modulation for high-capacity free-space optical links

Infrared free-space optics (FSO) provide an attractive solution for ultra-high-capacity wireless communications. However, the full potential of FSO is still being hindered by the apparent random fluctuations on the received optical power, which can be triggered by external factors such as atmospheric turbulence, weather instability, and pointing errors. Through the analysis of long-term experimental measurements, we identify the existence of significant time-domain memory in outdoor FSO links, which is found to be particularly strong under rainy weather conditions. Following this observation, we demonstrate that these memory effects can be effectively utilized to design accurate FSO channel estimation algorithms. Taking advantage of the arbitrary bit-rate granularity provided by probabilistic constellation shaping (PCS), and resorting to a simple moving average channel estimator, we demonstrate 400G+ transmission over a seamless fiber-FSO 55-m link with enhanced resilience towards adverse weather conditions. Comparing with unsupervised fixed modulation, we demonstrate a significant increase in average bit-rate (>35 Gbps) after continuous measurement over 3 hours, including raining periods

Comparative description of ten transcriptomes of newly sequenced invertebrates and efficiency estimation of genomic sampling in non-model taxa

Traditionally, genomic or transcriptomic data have been restricted to a few model or emerging model organisms, and to a handful of species of medical and/or environmental importance. Next-generation sequencing techniques have the capability of yielding massive amounts of gene sequence data for virtually any species at a modest cost. Here we provide a comparative analysis of de novo assembled transcriptomic data for ten non-model species of previously understudied animal taxa.Peer reviewe

The metallicity gradient of M 33: chemical abundances of HII regions

We present spectroscopic observations of a sample of 72 emission-line objects, including mainly HII regions, in the spiral galaxy M 33. Spectra were obtained with the multi-object, wide field spectrograph AF2/WYFFOS at the 4.2m WHT telescope. Line intensities, extinction, and electron density were determined for the whole sample of objects. The aim of the present work was to derive chemical and physical parameters of a set of HII regions, and from them the metallicity gradient. Electron temperatures and chemical abundances were derived for the 14 HII regions where both [OII] and [OIII] emission line fluxes were measured, including the electron temperature sensitive emission line [OIII] 436.3 nm and in a few cases [NII] 575.5 nm. The ionization correction factor (ICF) method was used to derive the total chemical abundances. The presence of abundance gradients was inferred from the radial behaviour of several emission-line ratios, and accurately measured from chemical abundances directly derived in 14 HII regions. The oxygen abundances of our HII regions, located in the radial region from ~2 to ~7.2 kpc, gave an oxygen gradient -0.054+/-0.011 dex/kpc The overall oxygen gradient for M 33 obtained using ours and previous oxygen determinations in a large number of HII regions with direct electron temperature determination as well as abundance in young stars presented a two slope shape: -0.19 dex/kpc for the central regions (R<3kpc), and -0.038dex/kpc for the outer regions (R>=3kpc).Comment: 16 pages, 14 figures, A&A accepted 10/05/200

Secure, Mobile Visual Sensor Networks Architecture

As Wireless Sensor Network-based solutions are proliferating they are facing new challenges: they must be capable of adapting to rapidly changing environments and requirements while their nodes should have low power consumption as they usually run on batteries. Moreover, the security aspect is crucial since they frequently transmit and process very sensitive data, while it is important to be able to support real-time video or processed images over their limited bandwidth links. SMART targets to design and implement a highly reconfigurable Wireless Visual Sensor Node (WVSN) defined as a miniaturized, light-weight, secure, low-cost, battery powered sensing device, enriched with video and data compression capabilities