37 research outputs found
CCD BVI photometry and Coravel observations of stars in the open cluster NGC 2489
We present CCD BVI photometry for the southern open cluster NGC 2489 and its surrounding field. The sample consists of 2182 stars measured in an area of 13.6 × 13.6 arcmin2, extending down to V∼ 21.5. These data are supplemented with CORAVEL radial-velocity observations for seven red giant candidates. A cluster angular radius of 6.7 ± 0.6 arcmin, equivalent to 3.5 ± 0.3 pc, is estimated from star counts carried out inside and outside the cluster region. The comparison of the cluster colour-magnitude diagrams with isochrones of the Padova group yields E(B−V) = 0.30 ± 0.05, E(V−I) = 0.40 ± 0.05 and V−MV= 12.20 ± 0.25 for log t= 8.70 (t= 500+130−100 Myr) and Z= 0.019. NGC 2489 is then located at 1.8 ± 0.3 kpc from the Sun and 25 pc below the Galactic plane. The analysis of the kinematical data allowed us to confirm cluster membership for six red giants, one of them being a spectroscopic binary. A mean radial velocity of 38.13 ± 0.33 km s−1 was derived for the cluster red giants. The properties of a sample of open clusters aligned along the line of sight of NGC 2489 are examine
Left ventricular thrombus mimicking primary cardiac tumor in a patient with primary antiphospholipid syndrome and recurrent systemic embolism
Primary antiphospholipid syndrome (APS) is a well-defined entity characterized by spontaneous
and recurrent abortion, thrombocytopenia and recurrent vascular thromboses (arterial
and venous). Left ventricular thrombus mimicking primary cardiac tumor with recurrent
systemic embolism has not been previously reported.
In this report we describe a 39 year-old man admitted to hospital presenting with left hemiparesis
and a peripheral embolism. He had no history of thrombotic events. Transthoracic
echocardiography showed a large, polypoid and mobile mass (4.0 × 1.2 cm) attached to the
apex of the left ventricle, highly suggestive of primary cardiac tumor. The patient subsequently
underwent open heart surgery. The histological examination showed an older thrombus and
a fresh thrombus. Post-operative laboratory tests showed lupus anticoagulant activity, confirming
the primary APS diagnosis. The patient initiated treatment with oral anticoagulation
(INR levels between 2 and 3) and was discharged 29 days after surgery. At ten month follow-up, he was symptom-free with long-term anticoagulation therapy. No evidence of intracardiac
mass recurrence on two-dimensional echocardiography was seen.
Intracardiac thrombus has been rarely reported as a complication of primary APS. Left ventricular
mass mimicking primary cardiac tumor with recurrent systemic embolism has not
been previously reported. Pre-operative investigations could not distinguish such a thrombus
from a cardiac tumor and the diagnosis was made post-operatively
Elevada Incidencia de Insuficiencia de Vitamina D en los Adultos Sanos Mayores de 65 Años en Diferentes Regiones de la Argentina
Con el objetivo de evaluar el estado nutricional de vitamina D en la población urbana clínicamente sana ambulatoria de Argentina se invitó a participar a 386 sujetos mayores de 65 años de 7 ciudades (entre 26 y 55º latitud Sur) entre fines del invierno y principios de la primavera. De ellos, 369 aceptaron, 30 presentaron criterios de exclusión clínicos o bioquímicos. Finalmente, se incluyeron 339 sujetos (226 mujeres y 113 hombres), con edad 71,3± 5,2 años (X ± SD). Los resultados fueron los siguientes: los niveles séricos de 25 hidroxivitamina D (25OHD) fueron menores en el Sur (latitud: 41- 55°S): 14,2± 5,6 ng/ml (p<0,0001 vs. las regiones Norte y Central); mayores en el Norte (26-27°S): 20,7±7,4 ng/ml (p<0,03 vs .Central; p<0,0001 vs. Sur); e intermedio en la región Central (33-34°S): 17,9±8,2 ng/ml. Se encontró una correlación negativa entre los niveles séricos de hormona paratiroidea (PTH) y 25OHD: r = -0,24 (p<0,001). El nivel de corte de 25OHD en el cual comenzaban a elevarse los niveles de PTH fue establecido en 27 ng/ml. En las diferentes regiones se observó una alta incidencia (52 a 87%) de niveles de insuficiencia de vitamina D (25OHD <20ng/ml) y solamente entre el 2 y 17% tenían niveles considerados como mínimos deseables de 25OHD (≥ 30 ng/ml). Conclusión: la deficiencia/insuficiencia de vitamina D en adultos mayores es un problema de escala mundial, incluida la población argentina. La corrección del déficit mencionado tendría un impacto positivo en la salud ósea de este grupo etarioFil: Oliveri, María Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. División Osteopatías; ArgentinaFil: Plantalech, Luisa. Hospital Italiano; ArgentinaFil: Bagur, Alicia Cristina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. División Osteopatías; ArgentinaFil: Wittich, Ana C.. No especifíca;Fil: Rovai, Gloria. No especifíca;Fil: Pusiol, Eduardo. No especifíca;Fil: Lopez Giovanelli, Jorge. No especifíca;Fil: Ponce, Graciela. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Nieva, Alfonso. No especifíca;Fil: Chaperon, Adriana. Sanatorio San Jorge; ArgentinaFil: Ladizesky, Marta Graciela. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. División Osteopatías; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Somoza, Julia Isabel. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. División Osteopatías; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Casco, Cristina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. División Osteopatías; ArgentinaFil: Zeni, Susana Noemi. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. División Osteopatías; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Parisi, Muriel Solange. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. División Osteopatías; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mautalen, Carlos Alfredo. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín. División Osteopatías; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
VISTA Variables in the <i>Vía Láctea</i> (VVV): Halfway Status and Results
The VISTA Variables in the Vía Láctea (VVV) survey is one of six near-infrared ESO public surveys, and is now in its fourth year of observing. Although far from being complete, the VVV survey has already delivered many results, some directly connected to the intended science goals (detection of variable stars, microlensing events, new star clusters), others concerning more exotic objects, e.g., novae. Now, at the end of the fourth observing period, and comprising roughly 50% of the proposed observations, the status of the survey, as well some of results based on the VVV data, are presented.Facultad de Ciencias Astronómicas y Geofísica
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Distribution of mosquitoes in the South East of Argentina and first report on the analysis based on 18S rDNA and COI sequences
Although Mar del Plata is the most important city on the Atlantic coast of Argentina, mosquitoes inhabiting such area are almost uncharacterized. To increase our knowledge in their distribution, we sampled specimens of natural populations. After the morphological identification based on taxonomic keys, sequences of DNA from small ribosomal subunit (18S rDNA) and cytochrome c oxidase I (COI) genes were obtained from native species and the phylogenetic analysis of these sequences were done. Fourteen species from the genera Uranotaenia, Culex, Ochlerotatus and Psorophora were found and identified. Our 18S rDNA and COI-based analysis indicates the relationships among groups at the supra-species level in concordance with mosquito taxonomy. The introduction and spread of vectors and diseases carried by them are not known in Mar del Plata, but some of the species found in this study were reported as pathogen vectors
A Mitosis Block Links Active Cell Cycle with Human Epidermal Differentiation and Results in Endoreplication
How human self-renewal tissues co-ordinate proliferation with differentiation is unclear. Human epidermis undergoes continuous cell growth and differentiation and is permanently exposed to mutagenic hazard. Keratinocytes are thought to arrest cell growth and cell cycle prior to terminal differentiation. However, a growing body of evidence does not satisfy this model. For instance, it does not explain how skin maintains tissue structure in hyperproliferative benign lesions. We have developed and applied novel cell cycle techniques to human skin in situ and determined the dynamics of key cell cycle regulators of DNA replication or mitosis, such as cyclins E, A and B, or members of the anaphase promoting complex pathway: cdc14A, Ndc80/Hec1 and Aurora kinase B. The results show that actively cycling keratinocytes initiate terminal differentiation, arrest in mitosis, continue DNA replication in a special G2/M state, and become polyploid by mitotic slippage. They unambiguously demonstrate that cell cycle progression coexists with terminal differentiation, thus explaining how differentiating cells increase in size. Epidermal differentiating cells arrest in mitosis and a genotoxic-induced mitosis block rapidly pushes epidermal basal cells into differentiation and polyploidy. These observations unravel a novel mitosis-differentiation link that provides new insight into skin homeostasis and cancer. It might constitute a self-defence mechanism against oncogenic alterations such as Myc deregulation
RepeatsDB in 2021: improved data and extended classification for protein tandem repeat structures
The RepeatsDB database (URL: https://repeatsdb.org/) provides annotations and classification for protein tandem repeat structures from the Protein Data Bank (PDB). Protein tandem repeats are ubiquitous in all branches of the tree of life. The accumulation of solved repeat structures provides new possibilities for classification and detection, but also increasing the need for annotation. Here we present RepeatsDB 3.0, which addresses these challenges and presents an extended classification scheme. The major conceptual change compared to the previous version is the hierarchical classification combining top levels based solely on structural similarity (Class > Topology > Fold) with two new levels (Clan > Family) requiring sequence similarity and describing repeat motifs in collaboration with Pfam. Data growth has been addressed with improved mechanisms for browsing the classification hierarchy. A new UniProt-centric view unifies the increasingly frequent annotation of structures from identical or similar sequences. This update of RepeatsDB aligns with our commitment to develop a resource that extracts, organizes and distributes specialized information on tandem repeat protein structures.Facultad de Ciencias ExactasInstituto de Biotecnologia y Biologia Molecula
Rare coding variants in PLCG2, ABI3, and TREM2 implicate microglial-mediated innate immunity in Alzheimer's disease
We identified rare coding variants associated with Alzheimer’s disease (AD) in a 3-stage case-control study of 85,133 subjects. In stage 1, 34,174 samples were genotyped using a whole-exome microarray. In stage 2, we tested associated variants (P<1×10-4) in 35,962 independent samples using de novo genotyping and imputed genotypes. In stage 3, an additional 14,997 samples were used to test the most significant stage 2 associations (P<5×10-8) using imputed genotypes. We observed 3 novel genome-wide significant (GWS) AD associated non-synonymous variants; a protective variant in PLCG2 (rs72824905/p.P522R, P=5.38×10-10, OR=0.68, MAFcases=0.0059, MAFcontrols=0.0093), a risk variant in ABI3 (rs616338/p.S209F, P=4.56×10-10, OR=1.43, MAFcases=0.011, MAFcontrols=0.008), and a novel GWS variant in TREM2 (rs143332484/p.R62H, P=1.55×10-14, OR=1.67, MAFcases=0.0143, MAFcontrols=0.0089), a known AD susceptibility gene. These protein-coding changes are in genes highly expressed in microglia and highlight an immune-related protein-protein interaction network enriched for previously identified AD risk genes. These genetic findings provide additional evidence that the microglia-mediated innate immune response contributes directly to AD development
New insights into the genetic etiology of Alzheimer's disease and related dementias
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo
Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level