115 research outputs found
Comparison of fish assemblages in two littoral habitats in a Neotropical morichal stream in Venezuela
Morichales are lowland streams in South American savannas with riparian forest dominated by the moriche palm (Mauritia flexuosa). We sampled littoral habitats from ten flooded vegetated patches (dominated by Mauritiella aculeate) and six sand banks in two months of the dry season (Feb-Mar 2005) in a stream in the savannas of Apure State, Venezuela. We collected samples that compromised 12,407 individual fishes of 107 species. Small-bodied fishes (\u3c 100 mm), representing diverse trophic and life history strategies, were abundant. The most abundant species were in the families Characidae and Cichlidae. Fish assemblages from flooded vegetated patches differed significantly from those on adjacent sand banks. High structural complexity along vegetated shoreline habitats of morichal streams likely contributes to species richness and affects assemblage composition
The Casiquiare river acts as a corridor between the Amazonas and Orinoco river basins: biogeographic analysis of the genus Cichla
The Casiquiare River is a unique biogeographic corridor between the Orinoco and Amazonas basins. We investigated the importance of this connection for Neotropical fishes using peacock cichlids ( Cichla spp.) as a model system. We tested whether the Casiquiare provides a conduit for gene flow between contemporary populations, and investigated the origin of biogeographic distributions that span the Casiquiare. Using sequences from the mitochondrial control region of three focal species ( C. temensis , C. monoculus , and C. orinocensis ) whose distributions include the Amazonas, Orinoco, and Casiquiare, we constructed maximum likelihood phylograms of haplotypes and analyzed the populations under an isolation-with-migration coalescent model. Our analyses suggest that populations of all three species have experienced some degree of gene flow via the Casiquiare. We also generated a mitochondrial genealogy of all Cichla species using >2000 bp and performed a dispersal-vicariance analysis (DIVA) to reconstruct the historical biogeography of the genus. This analysis, when combined with the intraspecific results, supports two instances of dispersal from the Amazonas to the Orinoco. Thus, our results support the idea that the Casiquiare connection is important across temporal scales, facilitating both gene flow and the dispersal and range expansion of species.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79059/1/j.1365-294X.2010.04540.x.pd
LMT/AzTEC observations of Vega
Vega is the prototypical debris disc system. Its architecture has been extensively studied at optical to millimetre wavelengths, revealing a near face-on, broad, and smooth disc with multiple distinct components. Recent millimetre-wavelength observations from ALMA spatially resolved the inner edge of the outer, cold planetesimal belt from the star for the first time. Here we present early science imaging observations of the Vega system with the AzTEC instrument on the 32-m LMT, tracing extended emission from the disc out to 150 au from the star. We compare the observations to three models of the planetesimal belt architecture to better determine the profile of the outer belt. A comparison of these potential architectures for the disc does not significantly differentiate between them with the modelling results being similar in many respects to the previous ALMA analysis, but differing in the slope of the outer region of the disc. The measured flux densities are consistent between the LMT (single dish) and ALMA (interferometric) observations after accounting for the differences in wavelength of observation. The LMT observations suggest the outer slope of the planetesimal belt is steeper than was suggested in the ALMA analysis. This would be consistent with the interferometric observations being mostly blind to structure at the disc outer edges, but the overall low signal to noise of the LMT observations does not definitively resolve the structure of the outer planetesimal belt.FK and JPM acknowledge research support by the Ministry of Science and Technology of Taiwan under grant MOST107-2119-M-001-031-MY3, and Academia Sinica under grant AS-IA-106-M03. JPM acknowledges research support by the Ministry of Science and Technology of Taiwan under grant MOST109-2112-M-001-036-MY3. MC thanks Consejo Nacional de Ciencia y Tecnología (CONACyT) for financial support through grant CB-2015-256961
Khuri-Treiman analysis of
We study the decay within the framework of
the Khuri-Treiman equations. We find that the BESIII experimental di-pion mass
distribution in the -region is well reproduced with a
once-subtracted -wave amplitude. Furthermore, we show that -wave
contributions to the amplitude improve the description of the data in the
mass region around 1.5 GeV. We also present predictions for the
transition form factor.Comment: 20 pages, 9 figure
Extensive Sheep and Goat Production: The Role of Novel Technologies towards Sustainability and Animal Welfare
ReviewSheep and goat extensive production systems are very important in the context of global
food security and the use of rangelands that have no alternative agricultural use. In such systems,
there are enormous challenges to address. These include, for instance, classical production issues, such
as nutrition or reproduction, as well as carbon-efficient systems within the climate-change context.
An adequate response to these issues is determinant to economic and environmental sustainability.
The answers to such problems need to combine efficiently not only the classical production aspects,
but also the increasingly important health, welfare, and environmental aspects in an integrated fashion. The purpose of the study was to review the application of technological developments,
in addition to remote-sensing in tandem with other state-of-the-art techniques that could be used
within the framework of extensive production systems of sheep and goats and their impact on
nutrition, production, and ultimately, the welfare of these species. In addition to precision livestock
farming (PLF), these include other relevant technologies, namely omics and other areas of relevance
in small-ruminant extensive production: heat stress, colostrum intake, passive immunity, newborn
survival, biomarkers of metabolic disease diagnosis, and parasite resistance breeding. This work
shows the substantial, dynamic nature of the scientific community to contribute to solutions that
make extensive production systems of sheep and goats more sustainable, efficient, and aligned with
current concerns with the environment and welfareinfo:eu-repo/semantics/publishedVersio
Evaluation of subclinical cardiovascular disease in patients with DM1
La diabetes mellitus tipo 1 (DM1) se caracteriza por un déficit absoluto de insulina. Los pa-cientes con DM1, poseen mayor riesgo de enfermedad cardiovascular (ECV) (enfermedad coronaria, miocar-diopatías, accidente cerebrovascular - ACV), y arterio-patía periférica (calcificaciones arteriales, enfermedad arterial oclusiva, presencia de amputaciones no trau-máticas). En estudios realizados con DM1 se observa que la Enfermedad coronaria se presenta en edades más tempranas, entre los 28-38 años, comparado con la población general donde el primer evento ocurre a partir de los 44 años. La asociación de anomalías vas-culares y aterosclerosis es muy frecuente en pacientes con DM1, siendo la detección del engrosamiento de ín-tima media carotideo un método útil para realizar diag-nóstico de enfermedad aterosclerótica subclínica.
Objetivos: realizar diagnóstico precoz de ECV subclí-nica e instaurar medidas terapéuticas tempranas
Early Science with the Large Millimeter Telescope: observations of dust continuum and CO emission lines of cluster-lensed submillimetre galaxies at z=2.0-4.7
We present Early Science observations with the Large Millimeter Telescope, AzTEC 1.1mm continuum images and wide bandwidth spectra (73-111GHz) acquired with the Redshift Search Receiver, towards four bright lensed submillimetre galaxies identified through the Herschel Lensing Survey-snapshot and the Submillimetre Common-User Bolometer Array-2 Cluster Snapshot Survey. This pilot project studies the star formation history and the physical properties of the molecular gas and dust content of the highest redshift galaxies identified through the benefits of gravitational magnification. We robustly detect dust continuum emission for the full sample and CO emission lines for three of the targets. We find that one source shows spectroscopic multiplicity and is a blend of three galaxies at different redshifts (z=2.040, 3.252, and 4.680), reminiscent of previous high-resolution imaging follow-up of unlensed submillimetre galaxies, but with a completely different search method, that confirm recent theoretical predictions of physically unassociated blended galaxies. Identifying the detected lines as 12CO (Jup=2-5) we derive spectroscopic redshifts, molecular gas masses, and dust masses from the continuum emission. The mean H2 gas mass of the full sample is (2.0±0.2)×1011 M⊙/μ, and the mean dust mass is (2.0±0.2)×109 M⊙/μ, where μ≈2-5 is the expected lens amplification. Using these independent estimations we infer a gas-to-dust ratio of δGDR≈55-75, in agreement with other measurements of submillimetre galaxies. Our magnified high-luminosity galaxies fall on the same locus as other high-redshift submillimetre galaxies, extending the -LFIR correlation observed for local luminous and ultraluminous infrared galaxies to higher far-infrared and CO luminositie
- …