2,270 research outputs found
Galaxy populations in the Antlia cluster - III. Properties of faint early-type galaxies
(Abridge) We present a new analysis of the early-type galaxy population in
the central region of the Antlia cluster, focusing on the faint systems like
dwarf ellipticals (dE) and dwarf spheroidals (dSph). We confirm 22 early-type
galaxies as Antlia members, using GEMINI-GMOS and MAGELLAN-MIKE spectra. Among
them, 2 belong to the rare type of compact ellipticals (cE), and 5 are new
faint dwarfs that had never been catalogued before. In addition, we present 16
newly identified low surface brightness galaxy candidates, almost half of them
displaying morphologies consistent with being Antlia's counterparts of Local
Group dSphs, that extend the faint luminosity limit of our study down to MB =
-10.1 (BT = 22.6) mag. We built an improved CMR in the Washington photometric
system, i.e. integrated T1 magnitudes versus (C - T1) colours, which extends
\sim 4 mag faintwards the limit of spectroscopically confirmed Antlia members.
When only confirmed early-type members are considered, this relation extends
over 10 mag in luminosity with no apparent change in slope or increase in
colour dispersion towards its faint end. The intrinsic colour scatter of the
relation is compared with those reported for other clusters of galaxies; we
argue that it is likely that the large scatter of the CMR, usually reported at
faint magnitudes, is mostly due to photometric errors along with an improper
membership/morphological classification. The distinct behaviour of the
luminosity versus mean effective surface brightness relation at the bright and
faint ends is analyzed, while it is confirmed that dE galaxies on the same
relation present a very similar effective radius, regardless of their colour.
The projected spatial distribution of the member sample confirms the existence
of two groups in Antlia, each one dominated by a giant elliptical galaxy and
with one cE located close to each giant.Comment: 19 pages, 9 figures, 5 tables. Accepted for publication in MNRA
Volumetric capnography and chronic obstructive pulmonary disease staging
Spirometry is difficult for some COPD patient to perform. Volumetric capnography could be a second choice test to evaluate the severity of functional disturbances. The aim of this work is to test this hypothesis. A total number of 98 subjects were classified either as normal ex-smokers (N=14) or COPD patients. The latter were staged following GOLD recommendations. Spirometry and volumetric capnography recordings were obtained from each patient. Spirometry parameters, Bohr Dead Space (V(D)Bohr), Airways Dead Space from the pre-interface expirate corrected curve (V(D)aw), Phase III slope (Sl(III)) and Volume of alveolar ejection (V(AE)) were measured. Index of Ventilatory Efficiency (IVE), and Index of Airways Heterogeneity (IAH) were calculated as: IVE = V(AE)/(V(T) - V(D)aw) and IAH = 1-[(V(T)-V(D)Bohr)/(V(T) - V(D)aw)]. In ANOCOVA analysis IAH showed the greatest association with stage (F >40), with no significant covariant dependence on V(T). A receiver operating characteristics curve analysis showed values of the area under the curve greater than 0.9 for IAH and IVE at all stage levels, with a sensitivity = specificity value greater than 80%. We conclude that IAH and IVE can be used when spirometry cannot be reliably performed, as an alternative test to evaluate the degree of functional involvement in COPD patients
Discard and by-catch of the shrimper fleet in a West African fishing ground: towards an Ecosystem Approach to Fisheries Management.
It is widely recognized that discards and overexploitation produced by intense fishing activities are not only a risk for fisheries sustainability but also the cause of the marine resources decline, this involving significant changes in the trophic webs and habitats. This is especially the case of bottom trawl fisheries, and more specifically shrimp trawls, which produce average discards that can be higher than 70% of catches.
A Spanish shrimp fishery has been traditionally developed in West African fishing grounds, being especially relevant in Mauritanian waters, due to their high productivity. Since 2010, discards produced by this fishery have been studied from the information obtained through a “Program of scientific observers onboard” carried out by the Spanish Institute of Oceanography (IEO). Two annual observation cycles (2010 and 2014) have been conducted in Mauritania, giving information on catches and discards from a total of 996 (2014) and 1143 hauls (2010). More than 250 species were identified in the discards produced by this fleet. Cluster analyses and multidimensional scaling (MDS) revealed the occurrence of three well-defined assemblages, related to the depth fishery of the three main target species: one coastal shelf assemblage, in fishing depths of the southern pink shrimp Penaeus notialis (30-60 m depth), one slope assemblage in fishing depths of the deep-water rose shrimp Parapenaeus longirostris (90-300 m) and a deep slope assemblage in fishing depths of the striped red shrimp Aristeus varidens (300-900 m). The structure of each assemblage is presented in this work.
Quantifying the bycatch and discard and identifying the main species are key steps to address a solution to effectively reduce their effects and to maintain healthy marine ecosystems.Fondo Europeo MarĂtimo y de Pesca (FEMP
Understanding the mechanisms of lung mechanical stress
Physical forces affect both the function and phenotype of cells in the lung. Bronchial, alveolar, and other parenchymal cells, as well as fibroblasts and macrophages, are normally subjected to a variety of passive and active mechanical forces associated with lung inflation and vascular perfusion as a result of the dynamic nature of lung function. These forces include changes in stress (force per unit area) or strain (any forced change in length in relation to the initial length) and shear stress (the stress component parallel to a given surface). The responses of cells to mechanical forces are the result of the cell's ability to sense and transduce these stimuli into intracellular signaling pathways able to communicate the information to its interior. This review will focus on the modulation of intracellular pathways by lung mechanical forces and the intercellular signaling. A better understanding of the mechanisms by which lung cells transduce physical forces into biochemical and biological signals is of key importance for identifying targets for the treatment and prevention of physical force-related disorders
High-Throughput Sequence Analysis of Turbot (Scophthalmus maximus) Transcriptome Using 454-Pyrosequencing for the Discovery of Antiviral Immune Genes
Turbot (Scophthalmus maximus L.) is an important aquacultural resource both in Europe and Asia. However, there is little information on gene sequences available in public databases. Currently, one of the main problems affecting the culture of this flatfish is mortality due to several pathogens, especially viral diseases which are not treatable. In order to identify new genes involved in immune defense, we conducted 454-pyrosequencing of the turbot transcriptome after different immune stimulations
First observations of oblique ionospheric sounding chirp signal in Mexico
The results of the first experiment of oblique ionospheric sounding (OIS) chirp signal reception in Mexico are
reported. Maximal and Lowest Observed Frequencies variations were studied under the quiet Space Weather
conditions. The diurnal ionospheric variations by OIS signal confirm the results based on GNSS data in the
Mexican region. The best HF radio propagation conditions along the considered path are during morning and
daytime hours. The multi-hop propagation is frequent. The interlayer propagation modes are present at nighttime
The Arabidopsis thioredoxin TRXh5regulates the S-nitrosylation pattern of the TIRK receptor being both proteins essential in the modulation of defences to Tetranychus urticae
The interaction between plants and phytophagous arthropods encompasses a complex network of molecules, signals, and pathways to overcome defences generated by each interacting organism. Although most of the elements and modulators involved in this interplay are still unidentified, plant redox homeostasis and signalling are essential for the establishment of defence responses. Here, focusing on the response of Arabidopsis thaliana to the spider mite Tetranychus urticae, we demonstrate the involvement in plant defence of the thioredoxin TRXh5, a small redox protein whose expression is induced by mite infestation. TRXh5 is localized in the cell membrane system and cytoplasm and is associated with alterations in the content of reactive oxygen and nitrogen species. Protein S-nitrosylation signal in TRXh5 over-expression lines is decreased and alteration in TRXh5 level produces changes in the JA/SA hormonal crosstalk of infested plants. Moreover, TRXh5 interacts and likely regulates the redox state of an uncharacterized receptor-like kinase, named THIOREDOXIN INTERACTING RECEPTOR KINASE (TIRK), also induced by mite herbivory. Feeding bioassays performed withTRXh5 over-expression plants result in lower leaf damage and reduced egg accumulation after T. urticae infestation than in wild-type (WT) plants. In contrast, mites cause a more severe injury in trxh5 mutant lines where a greater number of eggs accumulates. Likewise, analysis of TIRK-gain and -loss-of-function lines demonstrate the defence role of this receptor in Arabidopsis against T. urticae. Altogether, our findings demonstrate the interaction between TRXh5 and TIRK and highlight the importance of TRXh5 and TIRK in the establishment of effective Arabidopsis defences against spider mite herbivory.Grants PID2020-115219RB-I00, RED2018-102397-T and RyC17MESFB funded by MCIN/AEI/10.13039/501100011033, as appropriate, by “ERDF A way of making Europe” and by the “European Union” supported this work. Grants, SIMQG-263-1HWZ8Q UPM-Banco Santander Universidades, RyC2017-21814 and PRE2018-083375 from MCIN/AEI supported AA, MES and IRD, respectively. The Spanish Ministry of Science and Innovation (MCIN), the State Research Agency (AEI) and the European Regional Development Fund (ERDF; grant MEC-PID2021-122280NB-I00) financed MCRP and LMS. The Government of Canada through the Ontario Research Fund (RE08-067) and the Natural Sciences and Engineering Research Council of Canada (NSERC, RGPIB-2018-04538) supported VG
Nivel de conocimientos y su relación con las actitudes y prácticas preventivas del Zika
Objetivo. Este estudio descriptivo correlacional de corte transversal; se realizó para determinar el nivel de conocimientos y su relación con las actitudes y prácticas preventivas del Zika en el distrito de Chepen - La Libertad Perú. 2017. Materiales y métodos. Se aplicó un cuestionario sobre conocimiento, actitudes y prácticas preventivas en una muestra de 284 personas adultas, con una edad promedio de 37 años. Resultados. Los resultados demuestran que el nivel de conocimiento general sobre zika fue regular en un 79% y bueno en un 21%. En cuanto a las prácticas preventivas de zika más comunes que realizan los habitantes de Chepén, un 83% mencionan que lavan frecuentemente los depósitos de agua, 77% usan cepillo y detergente para lavar los depósitos con agua y 75% coloca una tapa sobre los depósitos con agua. Conclusiones. El nivel de conocimiento tiene una relación significativa con las practicas preventivas del zika (p0.05)
Properties of polyplexes formed between a cationic polymer derived from l-arabinitol and nucleic acids
In this work a sugar-based cationic polymer derived from l-arabinitol, PUArab, was prepared and its interactions with the linear calf thymus DNA and with the circular plasmid pEGFP-C1 were investigated at different N/P ratios. The polyplexes were characterized by using several techniques. For both nucleic acids, a charge inversion was observed, together with a conformational change from a coiled structure to a more compacted one. However, the N/P ratio required to observe the DNA condensation depended on the nucleic acid architecture. PUArab presents low toxicity in several cell lines. The transfection efficiency, TE, of the PUArab/pEGFP-C1 polyplexes was investigated at several N/P ratios in order to study their potential as vectors in gene transfection
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