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

Corrosión en soldaduras de aparatos de ortodoncia

Reaction dynamics of O({sup 1}D) atoms with H{sub 2} molecules was reinvestigated using the crossed molecular beams technique with pulsed beams. The O({sup 1}D) beam was generated by photodissociating O{sub 3} molecules at 248 nm. Time-of-flight spectra and the laboratory angular distribution of the OH products were measured. The derived OH product center-of-mass flux-velocity contour diagram shows more backward scattered intensity with respect to the O({sup 1}D) beam. In contrast to previous studies which show that the insertion mechanism is the dominant process, our results indicate that the contribution from the collinear approach of the O({sup 1}D) atom to the H{sub 2} molecule on the first excited state potential energy surface is significant and the energy barrier for the collinear approach is therefore minimal. Despite the increased time resolution in this experiment, no vibrational structure in the OH product time-of-flight spectra was resolved. This is in agreement with LIF studies, which have shown that the rotational distributions of the OH products in all vibrational states are broad and highly inverted

Adaptable Security in Wireless Sensor Networks by Using Reconfigurable ECC Hardware Coprocessors

Specific features of Wireless Sensor Networks (WSNs) like the open accessibility to nodes, or the easy observability of radio communications, lead to severe security challenges. The application of traditional security schemes on sensor nodes is limited due to the restricted computation capability, low-power availability, and the inherent low data rate. In order to avoid dependencies on a compromised level of security, a WSN node with a microcontroller and a Field Programmable Gate Array (FPGA) is used along this work to implement a state-of-the art solution based on ECC (Elliptic Curve Cryptography). In this paper it is described how the reconfiguration possibilities of the system can be used to adapt ECC parameters in order to increase or reduce the security level depending on the application scenario or the energy budget. Two setups have been created to compare the software- and hardware-supported approaches. According to the results, the FPGA-based ECC implementation requires three orders of magnitude less energy, compared with a low power microcontroller implementation, even considering the power consumption overhead introduced by the hardware reconfiguratio

Study of star-forming galaxies in SDSS up to redshift 0.4 II. Evolution from the fundamental parameters: mass, metallicity & SFR

To understand the formation and evolution of galaxies, it is important to have a full comprehension of the role played by the metallicity, star formation rate (SFR), morphology, and color. The interplay of these parameters at different redshifts will substantially affect the evolution of galaxies and, as a consequence, the evolution of them will provide important clues and constraints on the galaxy evolution models. In this work we focus on the evolution of the SFR, metallicity of the gas, and morphology of galaxies at low redshift in search of signs of evolution. We use the S2N2 diagnostic diagram as a tool to classify star--forming, composite, and AGN galaxies. We analyzed the evolution of the three principal BPT diagrams, estimating the SFR and specific SFR (SSFR) for our samples of galaxies, studying the luminosity and mass-metallicity relations, and analyzing the morphology of our sample of galaxies through the g-r color, concentration index, and SSFR. We found that the S2N2 is a reliable diagram to classify star--forming, composite, and AGNs galaxies. We demonstrate that the three principal BPT diagrams show an evolution toward higher values of [OIII]5007/Hb due to a metallicity decrement. We found an evolution in the mass-metallicity relation of ~ 0.2 dex for the redshift range 0.3 < z < 0.4 compared to our local one. From the analysis of the evolution of the SFR and SSFR as a function of the stellar mass and metallicity, we discovered a group of galaxies with higher SFR and SSFR at all redshift samples, whose morphology is consistent with those of late-type galaxies. Finally, the comparison of our local (0.04<z<0.1) with our higher redshift sample (0.3<z<0.4), show that the metallicity, the SFR and morphology, evolve toward lower values of metallicity, higher SFRs, and late--type morphologies for the redshift range 0.3<z<0.4Comment: 16 pages, 15 figures. Accepted for publication in A&

Bright Planetary Nebulae and their Progenitors in Galaxies Without Star Formation

We present chemical abundances for planetary nebulae in M32, NGC 185, and NGC 205 based upon spectroscopy obtained at the Canada-France-Hawaii Telescope using the Multi-Object Spectrograph. From these and similar data compiled from the literature for other Local Group galaxies, we consider the origin and evolution of the stellar progenitors of bright planetary nebulae in galaxies where star formation ceased long ago. The ratio of neon to oxygen abundances in bright planetary nebulae is either identical to that measured in the interstellar medium of star-forming dwarf galaxies or at most changed by a few percent, indicating that neither abundance is significantly altered as a result of the evolution of their stellar progenitors. Several planetary nebulae appear to have dredged up oxygen, but these are the exception, not the rule. The progenitors of bright planetary nebulae typically enhance their original helium abundances by less than 50%. In contrast, nitrogen enhancements can reach factors of 100. However, nitrogen often shows little or no enhancement, suggesting that nitrogen enrichment is a random process. The helium, oxygen, and neon abundances argue that the typical bright planetary nebulae in all of the galaxies considered here are the progeny of stars with initial masses of approximately 1.5 Msun or less, based upon the nucleosynthesis predictions of current theoretical models. These models, however, are unable to explain the nitrogen enrichment or its scatter. Similar conclusions hold for the bright planetary nebulae in galaxies with ongoing star formation. Thus, though composition varies significantly, there is unity in the sense that the progenitors of typical bright planetary nebulae appear to have undergone similar physical processes. (Abridged)Comment: accepted for publication in the Astrophysical Journa

Implications of population connectivity studies for the design of marine protected areas in the deep sea: An example of a demosponge from the Clarion-Clipperton Zone

The abyssal demosponge Plenaster craigi inhabits the Clarion‐Clipperton Zone (CCZ) in the northeast Pacific, a region with abundant seafloor polymetallic nodules with potential mining interest. Since P. craigi is a very abundant encrusting sponge on nodules, understanding its genetic diversity and connectivity could provide important insights into extinction risks and design of marine protected areas. Our main aim was to assess the effectiveness of the Area of Particular Environmental Interest 6 (APEI‐6) as a potential genetic reservoir for three adjacent mining exploration contract areas (UK‐1A, UK‐1B and OMS‐1A). As in many other sponges, COI showed extremely low variability even for samples ~900 km apart. Conversely, the 168 individuals of P. craigi, genotyped for 11 microsatellite markers, provided strong genetic structure at large geographical scales not explained by isolation by distance (IBD). Interestingly, we detected molecular affinities between samples from APEI‐6 and UK‐1A, despite being separated ~800 km. Although our migration analysis inferred very little progeny dispersal of individuals between areas, the major differentiation of OMS‐1A from the other areas might be explained by the occurrence of predominantly northeasterly transport predicted by the HYCOM hydrodynamic model. Our study suggests that although APEI‐6 does serve a conservation role, with species connectivity to the exploration areas, it is on its own inadequate as a propagule source for P. craigi for the entire eastern portion of the CCZ. Our new data suggest that an APEI located to the east and/or the south of the UK‐1, OMS‐1, BGR, TOML and NORI areas would be highly valuable

Meeting the International Health Regulations (2005) surveillance core capacity requirements at the subnational level in Europe: the added value of syndromic surveillance

BACKGROUND: The revised World Health Organization's International Health Regulations (2005) request a timely and all-hazard approach towards surveillance, especially at the subnational level. We discuss three questions of syndromic surveillance application in the European context for assessing public health emergencies of international concern: (i) can syndromic surveillance support countries, especially the subnational level, to meet the International Health Regulations (2005) core surveillance capacity requirements, (ii) are European syndromic surveillance systems comparable to enable cross-border surveillance, and (iii) at which administrative level should syndromic surveillance best be applied? DISCUSSION: Despite the ongoing criticism on the usefulness of syndromic surveillance which is related to its clinically nonspecific output, we demonstrate that it was a suitable supplement for timely assessment of the impact of three different public health emergencies affecting Europe. Subnational syndromic surveillance analysis in some cases proved to be of advantage for detecting an event earlier compared to national level analysis. However, in many cases, syndromic surveillance did not detect local events with only a small number of cases. The European Commission envisions comparability of surveillance output to enable cross-border surveillance. Evaluated against European infectious disease case definitions, syndromic surveillance can contribute to identify cases that might fulfil the clinical case definition but the approach is too unspecific to comply to complete clinical definitions. Syndromic surveillance results still seem feasible for comparable cross-border surveillance as similarly defined syndromes are analysed. We suggest a new model of implementing syndromic surveillance at the subnational level. In this model, syndromic surveillance systems are fine-tuned to their local context and integrated into the existing subnational surveillance and reporting structure. By enhancing population coverage, events covering several jurisdictions can be identified at higher levels. However, the setup of decentralised and locally adjusted syndromic surveillance systems is more complex compared to the setup of one national or local system. SUMMARY: We conclude that syndromic surveillance if implemented with large population coverage at the subnational level can help detect and assess the local and regional effect of different types of public health emergencies in a timely manner as required by the International Health Regulations (2005)