1,572 research outputs found
Radial velocities and metallicities from infrared Ca II triplet spectroscopy of open clusters II. Berkeley 23, King 1, NGC 559, NGC 6603 and NGC 7245
Context: Open clusters are key to studying the formation and evolution of the
Galactic disc. However, there is a deficiency of radial velocity and chemical
abundance determinations for open clusters in the literature. Aims: We intend
to increase the number of determinations of radial velocities and metallicities
from spectroscopy for open clusters. Methods: We acquired medium-resolution
spectra (R~8000) in the infrared region Ca II triplet lines (~8500 AA) for
several stars in five open clusters with the long-slit IDS spectrograph on the
2.5~m Isaac Newton Telescope (Roque de los Muchachos Observatory, Spain).
Radial velocities were obtained by cross-correlation fitting techniques. The
relationships available in the literature between the strength of infrared Ca
II lines and metallicity were also used to derive the metallicity for each
cluster. Results: We obtain = 48.6+/-3.4, -58.4+/-6.8, 26.0+/-4.3 and
-65.3+/-3.2 km s-1 for Berkeley 23, NGC 559, NGC 6603 and NGC 7245,
respectively. We found [Fe/H] =-0.25+/-0.14 and -0.15+/-0.18 for NGC 559 and
NGC 7245, respectively. Berkeley 23 has a low metallicity, [Fe/H]
=-0.42+/-0.13, similar to other open clusters in the outskirts of the Galactic
disc. In contrast, we derived a high metallicity ([Fe/H] =+0.43+/-0.15) for NGC
6603, which places this system among the most metal rich known open clusters.
To our knowledge, this is the first determination of radial velocities and
metallicities from spectroscopy for these clusters, except NGC 6603, for which
radial velocities had been previously determined. We have also analysed ten
stars in the line of sight to King 1. Because of the large dispersion obtained
in both radial velocity and metallicity, we cannot be sure that we have sampled
true cluster members.Comment: 10 pages, 5 figures, accepted for publication in A&A (minor
modifications
The origin of the LMC stellar bar: clues from the SFH of the bar and inner disk
We discuss the origin of the LMC stellar bar by comparing the star formation
histories (SFH) obtained from deep color-magnitude diagrams (CMDs) in the bar
and in a number of fields in different directions within the inner disk. The
CMDs, reaching the oldest main sequence turnoffs in these very crowded fields,
have been obtained with VIMOS on the VLT in service mode, under very good
seeing conditions. We show that the SFHs of all fields share the same patterns,
with consistent variations of the star formation rate as a function of time in
all of them. We therefore conclude that no specific event of star formation can
be identified with the formation of the LMC bar, which instead likely formed
from a redistribution of disk material that occurred when the LMC disk became
bar unstable, and shared a common SFH with the inner disk thereafter. The
strong similarity between the SFH of the center and edge of the bar rules out
significant spatial variations of the SFH across the bar, which are predicted
by scenarios of classic bar formation through buckling mechanisms.Comment: MNRAS Letters, accepte
Development, Characterization, and In Vitro Evaluation of Tamoxifen Microemulsions
Microemulsions (MEs) were designed by an innovative rational development, characterized, and used to load up to 20 mM of Tamoxifen citrate (TMX). They were made with acceptable and well-characterized excipients for all the routes of administration. Some of their properties, such as nanometric mean size and long stability shelf life, make them interesting drug delivery systems. The results obtained after the in vitro inhibition of estradiol-induced proliferation in MCF-7 breast cancer cells demonstrated a significant effect in cell growth. A decreasing of at least 90% in viable cells was shown after the incubation with MEs containing 20 mM of TMX. Besides, two compositions which loaded 10 mM of drug showed a cytotoxic effect higher than 70%. These results encourage the evaluation of alternative protocols for this drug administration, not only for estrogen receptor (ER) positive tumors, but also for ER negative
Host association of cryptosporidium parvum populations infecting domestic ruminants in Spain
A stock of 148 Cryptosporidium parvum DNA extracts from lambs and goat kids selected from a previous study examining the occurrence of Cryptosporidium species and GP60 subtypes in diarrheic lambs and goat kids in northeastern Spain was further characterized by a multilocus fragment typing approach with six mini- and microsatellite loci. Various degrees of polymorphism were seen at all but the MS5 locus, although all markers exhibited two major alleles accounting for more than 75% of isolates. A total of 56 multilocus subtypes (MLTs) from lambs (48 MLTs) and goat kids (11 MLTs) were identified. Individual isolates with mixed MLTs were detected on more than 25% of the farms, but most MLTs (33) were distinctive for individual farms, revealing the endemicity of cryptosporidial infections on sheep and goat farms. Comparison with a previous study in calves in northern Spain using the same six-locus subtyping scheme showed the presence of host-associated alleles, differences in the identity of major alleles, and very little overlap in MLTs between C. parvum isolates from lambs and those from calves (1 MLT) or isolates from lambs and those from goat kids (3 MLTs). The Hunter-Gaston index of the multilocus technique was 0.976 (95% confidence interval [CI], 0.970 to 0.982), which supports its high discriminatory power for strain typing and epidemiological tracking. Population analyses revealed the presence of two host-associated subpopulations showing epidemic clonality among the C. parvum isolates infecting calves and lambs/goat kids, respectively, although evidence of genetic flow between the two subpopulations was also detected
Intra-Species Diversity and Panmictic Structure of Cryptosporidium parvum Populations in Cattle Farms in Northern Spain
The intra-herd and intra-host genetic variability of 123 Cryptosporidium parvum isolates was investigated using a multilocus fragment typing approach with eleven variable-number tandem-repeat (VNTR) loci and the GP60 gene. Isolates were collected from intensively farmed diarrheic pre-weaned calves originating from 31 dairy farms in three adjoining regions in northern Spain (País Vasco, Cantabria and Asturias). The multilocus tool demonstrated an acceptable typeability, with 104/123 samples amplifying at all twelve loci. The ML2, TP14, GP60 and the previously un-described minisatellite at locus cgd2_3850 were the most discriminatory markers, while others may be dismissed as monomorphic (MSB) or less informative (CP47, ML1 and the novel minisatellites at loci Cgd1_3670 and Cgd6_3940). The 12-satellite typing tool provided a Hunter-Gaston index (HGDI) of 0.987 (95% CI, 0.982–0.992), and differentiated a total of 70 multilocus subtypes (MLTs). The inclusion of only the four most discriminatory markers dramatically reduced the number of MLTs (n: 44) but hardly reduced the HGDI value. A total of 54 MLTs were distinctive for individual farms, indicating that cryptosporidiosis is an endemic condition on most cattle farms. However, a high rate of mixed infections was detected, suggesting frequent meiotic recombination. Namely, multiple MLTs were seen in most farms where several specimens were analyzed (90.5%), with up to 9 MLTs being found on one farm, and individual specimens with mixed populations being reported on 11/29 farms. Bayesian Structure analysis showed that over 35% of isolates had mixed ancestry and analysis of evolutionary descent using the eBURST algorithm detected a high rate (21.4%) of MLTs appearing as singletons, indicating a high degree of genetic divergence. Linkage analysis found evidence of linkage equilibrium and an overall panmictic structure within the C. parvum population in this discrete geographical area
Optimized polarization build-up times in dissolution DNP-NMR using a benzyl amino derivative of BDPA
The synthesis of two novel BDPA-like radicals, a benzyl amino (BAm-BDPA, 7) and a cyano (CN-BDPA, 5)
derivative, is reported and their behaviour as polarizing agents for fast dissolution Dynamic Nuclear
Polarization (DNP) is evaluated. The radical 7 is a promising candidate for DNP studies since it is soluble
in neat [1-13C]pyruvic acid (PA), and therefore the use of an additional glassing agent for sample
homogeneity is avoided. In addition, a 60 mM sample of 7 offers optimum 13C NMR signal
enhancements using fairly short polarization times (about 1800 s). It is shown that DNP-NMR
measurements using 7 can be performed much more efficiently in terms of the signal enhancement per
polarization build-up time unit than when using the reference OX63 or BDPA radicals. These enhanced
features are translated to a substantial reduction of polarization times that represents an optimum
temporary use of the DNP polarizer and allow economized liquid helium consumption.This research was supported by the DGI Grants “POMAs”
(CTQ2010-19501) and “Be-Well” (CTQ2013-40480 R), MINECO
(CTQ2012-32436), AGAUR Grant (2014SGR-0017) and MINECO
Grant (PTA 2011-5037-I) for the subprogram Personal T´ecnico
de Apoyo. We also thank the Networking Research Center on
Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN),
the Consejo Superior de Investigaciones Cient´ıcas for the JAE
Grant, and Amable Bernab´e for his work in MALDI spectrometry.
NMR studies were carried out at the joint NMR facility of
the Universitat Aut`onoma de Barcelona and CIBER-BBN (Cerdanyola
del Vall`es).Peer reviewe
Gender bias in ecosystem restoration: from science to practice
The declaration of the United Nations Decade on Ecosystem Restoration 2020–2030 has established the need to focus on human rights in restoration initiatives, including gender equality. Although this goal raises a need to monitor gender biases on ecosystem restoration, we still lack basic gender information and evaluations on the current situation. The main purpose of this study is to analyze gender bias in ecosystem restoration covering three dimensions: research, outreach, and practice. We used scientific publications from the Restoration Ecology journal, mentions of these articles in Altmetric Explorer and Twitter, and projects from the Society for Ecological Restoration's database. First, we study gender bias among people leading ecosystem restoration initiatives in the three dimensions. Second, we assessed factors that could influence gender bias, including year, target ecosystem, and socioeconomic country development. Third, we analyzed whether the impact of scientific knowledge in society depends on the gender of the scientific team. Our results indicate that men were primary leaders in research, outreach, and practice initiatives in ecosystem restoration. There seems to be a trend over time toward equality in research, but gender inequality is still present in most types of ecosystems, with women leading more projects in more developed countries. The impact of scientific knowledge is independent of the author's gender, but research of male senior authors seems to reach society more easily. This broad perspective of inequality in the three dimensions can evolve toward gender equality, by applying gender approaches in restoration policies and initiatives. © 2022 Society for Ecological Restoration.Raw data is publicly available thanks to Web of Science, Altmetrics, Twitter and SER. Data and scripts used for the analysis are available via Figshare (Cruz‐Alonso et al. 2022 ). Funding: V.C.‐A.—Real Colegio Complutense postdoc fellowship; A.R.‐U.—Spanish State Research Agency through María de Maeztu Excellence Unit accreditation 2018–2022 (MDM‐2017‐0714); L.M.—Swiss National Science Foundation (PCEFP2_181115) and a Margarita Salas Postdoctoral Fellowship from Universidad de Alcalá; L.M.‐B.—Ministerio de Ciencia e Innovación (PID2019‐106806GB‐I00) and a Margarita Salas Postdoctoral Fellowship from Universidad de Alcalá; N.M.—predoctoral grant from Universidad de Alcalá; E.V.‐A.—European Commission (project SHOWCASE, H2020: 862480). We appreciate the support of the FIRE Foundation and the comments of M. Almaraz, M. Pajares, A. S. Moya, and D. Rohrer to improve the manuscript.Raw data is publicly available thanks to Web of Science, Altmetrics, Twitter and SER. Data and scripts used for the analysis are available via Figshare (Cruz‐Alonso et al. 2022 ). Funding: V.C.‐A.—Real Colegio Complutense postdoc fellowship; A.R.‐U.—Spanish State Research Agency through María de Maeztu Excellence Unit accreditation 2018–2022 (MDM‐2017‐0714); L.M.—Swiss National Science Foundation (PCEFP2_181115) and a Margarita Salas Postdoctoral Fellowship from Universidad de Alcalá; L.M.‐B.—Ministerio de Ciencia e Innovación (PID2019‐106806GB‐I00) and a Margarita Salas Postdoctoral Fellowship from Universidad de Alcalá; N.M.—predoctoral grant from Universidad de Alcalá; E.V.‐A.—European Commission (project SHOWCASE, H2020: 862480). We appreciate the support of the FIRE Foundation and the comments of M. Almaraz, M. Pajares, A. S. Moya, and D. Rohrer to improve the manuscript
Sirolimus enhances the protection achieved by a DNA vaccine against Leishmania infantum
Background
Leishmaniases are a group of neglected tropical parasitic diseases, mainly affecting vulnerable populations of countries with poor socioeconomic status. Development of efficient vaccines is a priority due to the increasing incidence of drug resistance and toxicity to current treatments. In the search for a safe and efficient protective vaccine for human and dog visceral leishmaniases, we analyzed the suitability of the immunomodulatory drug sirolimus (SIR) to boost a preventive DNA vaccine against leishmaniasis. SIR is an already marketed drug that has been described to boost immune protection against different disease models and has also emerged as a promising therapeutic drug against L. major.
Methods
Syrian hamsters were treated with SIR concomitantly with the administration of a DNA vaccine formulation consisting in four plasmids carrying the Leishmania genes LACK, TRYP, PAPLE22 and KMPII, respectively. Two weeks after the last vaccination, the animals were infected intraperitoneally with L. infantum parasites. Five weeks post-infection the parasite load was measured by real-time PCR in target tissues and immune response was evaluated by determining anti-Leishmania specific antibodies in combination with cytokine expression in the spleen.
Results
Our results show that the DNA vaccine itself efficiently reduced the burden of parasites in the skin (P = 0.0004) and lymph nodes (P = 0.0452). SIR administration also enhanced the protection by reducing the parasite load in the spleen (P = 0.0004). Vaccinated animals with or without SIR co-treatment showed lower IFN-γ expression levels than those found in the spleen of control animals. mRNA expression levels of NOS2 and IL-10 were found to be significantly higher in the vaccinated plus SIR treated group.
Conclusions
Co-administration of SIR enhances a DNA vaccination regimen against L. infantum, improving the reduction of parasite load in skin, lymph node and spleen. The analysis of immune markers in the spleen after challenge suggests that the trend to recover naïve levels of IFN-γ and IL-10, and the concurrent higher expression of NOS2, may be responsible for the protection induced by our vaccine co-administered with SIR.info:eu-repo/semantics/publishedVersio
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