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

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

Síndrome metabólico y su relación con hipogonadismo tardío

Existen evidencias clínicas y experimentales que muestran una asociación entre niveles bajos de testosterona (T) e insulino resistencia (IR), síndrome metabólico y diabetes tipo 2. La etiología no ha sido completamente dilucidada pero, diversos estudios muestran que el mecanismo sería bidireccional. La IR puede manifestarse en el eje hipotálamo-hipófisis-testículo (HHT), disminuyendo la respuesta testicular a LH y la secreción de testosterona (T). Por otra parte, la disminudón de T favorece la IR muscular y los depósitos de grasa visceral. La grasa visceral secreta en exceso adipokinas como leptina y TNF-α que influyen negativamente sobre el eje HHT determinando disminución de secreción de T. En cuanto a la terapia de reemplazo con testosterona, los trabajos publicados a la fecha no han sido concluyentes y aún faltan trabajos con un diseño adecuado, que clarifiquen los riesgos y beneficios reales. Por Io tanto, en pacientes con DM2 o SM y niveles de T bap lo normal, se recomienda que la terapia de sustitución sea evaluada e indicada por un especialista en endocrinología o andrología. Conclusiones: En todo paciente con un hipogonadismo demostrado se debe buscar elementos del SM pero, en los pacientes con SM o DM2, la medición de T se debe considerar sólo si hay otros elementos clínicos que orienten a una deficiencia de andrógenos. En cuanto a la indicación de terapia de reemplazo en los pacientes diabéticos o con SM, aún faltan estudios controlados, a largo plazo que evalúen los beneficios reales, metabólicos y cardiovasculares. Lo fundamental en estos pacientes es la prevención, promoviendo un estilo de vida saludable

Immunohistochemistry for pituitary hormones and Ki-67 in growth hormone producing pituitary adenomas Evaluación por inmunohistoquímica de la expresión de hormonas hipofisiarias y del marcador de proliferación celular Ki-67 en tejido de adenomas causantes

Background: Growth hormone (GH) producing adenomas, frequently express several hormones. This condition could confer them a higher proliferative capacity. Ki-67 is a nuclear protein antigen that is a marker for proliferative activity. Aim: To measure the immunohistochemical hormone expression in pituitary adenomas, excised from patients with acromegaly. To determine if the plurihormonal condition of these adenomas is associated with a higher proliferative capacity, assessed through the expression of Ki-67. Material and methods: Forty one paraffin embedded surgical samples of pituitary adenomas from patients with acromegalia were studied. Immunohistochemistry for GH, prolactin (PRL), follicle stimulating hormone (FSH), luteinizing hormone (LH), thyroid stimulating hormone (TSH), adrenocorticotropin (ACTH) and for the expression of Ki-67 was carried out. Results: All samples were positive for GH. Twenty seven had positive staining for PRL, 12 had positive staining for glycoproteic hormo