660 research outputs found
Spatiotemporal Overlap Of Spiny Dogfish (Squalus Acanthias) And Commercial Fisheries In The Northeast Us Shelf Large Marine Ecosystem
Commercial fishermen have argued that localized concentrations of spiny dogfish (Squalus acanthias) in the northeast U.S. shelf large marine ecosystem (NES LME) have impeded their fishing operations when monitoring surveys estimated lower relative abundances. Fishery-dependent and -independent data were analyzed simultaneously to examine whether increased spatial overlap between spiny dogfish and commercial fisheries may explain high catches of this species on fishing grounds. Spatial overlap was quantified between spiny dogfish distribution and commercial fisheries from 1989 to 2009 during autumn and spring in the NES LME. Combined, the sink gillnet (SGN) and otter trawl (OT) fisheries accounted for the majority of spiny dogfish catch (autumn: 85%; spring: 92%), either retained (SGN) or discarded (OT). Centers of spiny dogfish abundance illustrated spatial differences in local density within the NES LME and revealed seasonal differences in spiny dogfish density. Recent increases in spatial overlap indicate that a growing portion of the spiny dogfish stock was available to each fishery over the time series. Availability, estimated as the percentage of spiny dogfish present on fishing grounds, also increased and was generally higher during autumn than spring. Abundance of mature (total length.80 cm) female spiny dogfish was significantly related to availability, but trends were variable between fisheries and seasons. Although recent increases in abundance indicate recovery, research regarding the mechanisms behind these changes may help explain why abundance in the NES LME appears highly variable
Superelastic damping at nanoscale in ternary and quaternary Cu-based shape memory alloys
Superelasticity is a characteristic thermomechanical property in shape memory alloys (SMA), which is due to a reversible stress-induced martensitic transformation. Nano-compression experiments made possible the study of this property in Cu–Al–Ni SMA micropillars, showing an outstanding ultra-high mechanical damping capacity reproducible for thousands of cycles and reliable over the years. This scenario motivated the present work, where a comparative study of the damping capacity on four copper-based SMA: Cu–Al–Ni, Cu–Al–Be, Cu–Al–Ni–Be and Cu–Al–Ni–Ga is approached. For this purpose, [001] oriented single-crystal micropillars of comparable dimensions (around 1 µm in diameter) were milled by focused ion beam technique. All micropillars were cycled up to two hundred superelastic cycles, exhibiting a remarkable reproducibility. The damping capacity was evaluated through the dimensionless loss factor η, calculated for each superelastic cycle, representing the dissipated energy per cycle and unit of volume. The calculated loss factor was averaged between three micro-pillars of each alloy, obtaining the following results: Cu–Al–Ni η = 0.20 ± 0.01; Cu–Al–Be η = 0.100 ± 0.006; Cu–Al–Ni–Be η = 0.072 ± 0.004 and Cu–Al–Ni–Ga η = 0.042 ± 0.002. These four alloys exhibit an intrinsic superelastic damping capacity and offer a wide loss factor band, which constitutes a reference for engineering, since this kind of micro/nano structures can potentially be integrated not only as sensors and actuators but also as dampers in the design of MEMS to improve their reliability. In addition, the study of the dependence of the superelastic loss factor on the diameter of the pillar was approached in the Cu–Al–Ni–Ga alloy, and here we demonstrate that there is a size effect on damping at the nanoscale.Fil: GĂłmez CortĂ©s, J.F.. Universidad del PaĂs Vasco; EspañaFil: Fuster, Valeria de Los Angeles. Universidad del PaĂs Vasco; España. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; ArgentinaFil: PĂ©rez Cerrato, M.. Universidad del PaĂs Vasco; EspañaFil: Lorenzo, P.. Universidad del PaĂs Vasco; EspañaFil: Ruiz Larrea, I.. Universidad del PaĂs Vasco; EspañaFil: Breczewski, T.. Universidad del PaĂs Vasco; EspañaFil: NĂł, M. L.. Universidad del PaĂs Vasco; EspañaFil: San Juan, J. M.. Universidad del PaĂs Vasco; Españ
Evolution of realized Eltonian niches across Rajidae species
The notion that closely related species resemble each other in ecological niche space (i.e., phylogenetic dependence) has been a long-standing, contentious paradigm in evolutionary biology, the incidence of which is important for predicting the ecosystem-level effects of species loss. Despite being examined across a multitude of terrestrial taxa, many aspects of niche conservatism have yet to be explored in marine species, especially for characteristics related to resource use and trophic behavior (Eltonian niche characteristics, ENCs). We combined ENCs derived from stable isotope ratios at assemblage- and species-levels with phylogenetic comparative methods, to test the hypotheses that benthic marine fishes (1) exhibit similar assemblage-wide ENCs regardless of geographic location and (2) display phylogenetically dependent ENCs at the species level. We used a 12-species sub-set of the monophyletic group Rajidae sampled from three independent assemblages (Central California, Gulf of Alaska, and Northwest Atlantic), which span two ocean basins. Assemblage-level ENCs implied low trophic diversity and high evenness, suggesting that Rajidae assemblages may exhibit a well-defined trophic role, a trend consistent regardless of geographic location. At the species level, we found evidence for phylogenetic dependence of ENCs relating to trophic diversity (i.e., isotopic niche width; SEAc). Whether individuals can be considered functional equivalents across assemblages is hard to ascertain because we did not detect a significant phylogenetic signal for ENCs relating to trophic function (e.g., trophic position). Thus, additional, complimentary approaches are required to further examine the phylogenetic dependence of species functionality. Our approach illustrates the potential of stable isotope-derived niche characteristics to provide insight on macroecological processes occurring across evolutionary time, which could help predict how assemblages may respond to the effects of species loss
The Spanish SpaceWeather Service SeNMEs. A Case Study on the Sun-Earth Chain
ComunicaciĂłn presentada en el Coimbra Solar Physics Meeting, 5-9 October 2015, Coimbra, PortugalThe Spanish Space Weather Service SeNMEs, www.senmes.es, is a portal
created by the SRG-SW of the Universidad de Alcalá, Spain, to meet societal needs
of near real-time space weather services. This webpage-portal is divided in different
sections to fulfill users needs about space weather effects: radio blackouts, solar energetic
particle events, geomagnetic storms and presence of geomagnetically induced
currents.
In less than one year of activity, this service has released a daily report concerning
the solar current status and interplanetary medium, informing about the chances of a
solar perturbation to hit the Earth’s environment. There are also two different forecasting
tools for geomagnetic storms, and a daily ionospheric map. These tools allow us
to nowcast a variety of solar eruptive events and forecast geomagnetic storms and their
recovery, including a new local geomagnetic index, LDiñ, along with some specific new
scaling.
In this paper we also include a case study analysed by SeNMEs. Using different
high resolution and cadence data from space-borne solar telescopes SDO, SOHO and
GOES, along with ionospheric and geomagnetic data, we describe the Sun-Earth feature
chain for the event.MINECO project AYA2013-47735PPeer reviewe
Tbx1 expression in pharyngeal epithelia is necessary for pharyngeal arch artery development.
During embryonic life, the initially paired pharyngeal arch arteries (PAAs) follow a precisely orchestrated program of persistence and regression that leads to the formation of the mature aortic arch and great vessels. When this program fails, specific cardiovascular defects arise that may be life threatening or mild, according to the identity of the affected artery. Fourth PAA-derived cardiovascular defects occur commonly in DiGeorge syndrome and velocardiofacial syndrome (22q11DS), and in Tbx1(+/-) mice that model the 22q11DS cardiovascular phenotype. Tbx1 is expressed in pharyngeal mesoderm, endoderm and ectoderm, and, in addition, we show that it is expressed in precursors of the endothelial cells that line the PAAs, thus expanding the number of tissues in which Tbx1 is potentially required for fourth PAA development. In this study, we have used cell fate mapping and tissue-specific gene deletion, driven by six different Cre lines, to explore Tbx1 gene-dosage requirements in the embryonic pharynx for fourth PAA development. Through this approach, we have resolved the spatial requirements for Tbx1 in this process, and we show pharyngeal epithelia to be a critical tissue. We also thereby demonstrate conclusively that the role of Tbx1 in fourth PAA development is cell non-autonomous
Chromatin accessibility dynamics across C. elegans development and ageing
An essential step for understanding the transcriptional circuits that control development and physiology is the global identification and characterization of regulatory elements. Here we present the first map of regulatory elements across the development and ageing of an animal, identifying 42,245 elements accessible in at least one C. elegans stage. Based on nuclear transcription profiles, we define 15,714 protein-coding promoters and 19,231 putative enhancers, and find that both types of element can drive orientation-independent transcription. Additionally, more than 1000 promoters produce transcripts antisense to protein coding genes, suggesting involvement in a widespread regulatory mechanism. We find that the accessibility of most elements changes during development and/or ageing and that patterns of accessibility change are linked to specific developmental or physiological processes. The map and characterization of regulatory elements across C. elegans life provides a platform for understanding how transcription controls development and ageing
Sex differences in treatment strategy for coronary artery aneurysms: Insights from the international Coronary Artery Aneurysm Registry
INTRODUCTION: Sex disparities exist in coronary artery disease (CAD) in terms of risk profile, clinical management and outcome. It is unclear if differences are also present in coronary aneurysms, a rare variant of CAD.
METHODS: Patients were selected from the international Coronary Artery Aneurysm Registry (CAAR; ClinicalTrials.gov: NCT02563626), and differences between groups were analysed according to sex. The CAAR database is a prospective multicentre registry of 1565 patients with coronary aneurysms (336 females). Kaplan-Meier method was used for event-free survival analysis for death, major adverse cardiac events (MACE: composite endpoint of death, heart failure and acute coronary syndrome) and bleeding.
RESULTS: Female patients were older, were more often hypertensive and less frequently smoker. They were treated conservatively more often compared to male patients and received significantly less frequently aspirin (92% vs 88%, p = 0.002) or dual antiplatelet therapy (DAPT) (67% vs 58%, p = 0.001) at discharge. Median DAPT duration was also shorter (3 vs 9 months, p = 0.001). Kaplan-Meier analysis revealed no sex differences in death, MACE or bleeding during a median follow-up duration of 37 months, although male patients did experience acute coronary syndrome (ACS) more often during follow-up (15% vs 10%, p = 0.015).
CONCLUSIONS: These CAAR findings showed a comparable high-risk cardiovascular risk profile for both sexes. Female patients were treated conservatively more often and received DAPT less often at discharge, with a shorter DAPT duration. ACS was more prevalent among male patients; however, overall clinical outcome was not different between male and female patients during follow-up
Molecular Interactions of Prodiginines with the BH3 Domain of Anti-Apoptotic Bcl-2 Family Members
Prodigiosin and obatoclax, members of the prodiginines family, are small molecules with anti-cancer properties that are
currently under preclinical and clinical trials. The molecular target(s) of these agents, however, is an open question.
Combining experimental and computational techniques we find that prodigiosin binds to the BH3 domain in some BCL-2
protein families, which play an important role in the apoptotic programmed cell death. In particular, our results indicate
a large affinity of prodigiosin for MCL-1, an anti-apoptotic member of the BCL-2 family. In melanoma cells, we demonstrate
that prodigiosin activates the mitochondrial apoptotic pathway by disrupting MCL-1/BAK complexes. Computer simulations
with the PELE software allow the description of the induced fit process, obtaining a detailed atomic view of the molecular
interactions. These results provide new data to understand the mechanism of action of these molecules, and assist in the
development of more specific inhibitors of anti-apoptotic BCL-2 proteins.Spanish government and the European Union (FIS-PI10/00338) and from the ERC-2009-Adg
25027-PELE European project
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