Observation of gravitational waves from the coalescence of a 2.5–4.5 M ⊙ compact object and a neutron star

We report the observation of a coalescing compact binary with component masses 2.5–4.5 M ⊙ and 1.2–2.0 M ⊙ (all measurements quoted at the 90% credible level). The gravitational-wave signal GW230529_181500 was observed during the fourth observing run of the LIGO–Virgo–KAGRA detector network on 2023 May 29 by the LIGO Livingston observatory. The primary component of the source has a mass less than 5 M ⊙ at 99% credibility. We cannot definitively determine from gravitational-wave data alone whether either component of the source is a neutron star or a black hole. However, given existing estimates of the maximum neutron star mass, we find the most probable interpretation of the source to be the coalescence of a neutron star with a black hole that has a mass between the most massive neutron stars and the least massive black holes observed in the Galaxy. We provisionally estimate a merger rate density of 55−47+127Gpc−3yr−1 for compact binary coalescences with properties similar to the source of GW230529_181500; assuming that the source is a neutron star–black hole merger, GW230529_181500-like sources may make up the majority of neutron star–black hole coalescences. The discovery of this system implies an increase in the expected rate of neutron star–black hole mergers with electromagnetic counterparts and provides further evidence for compact objects existing within the purported lower mass gap

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

Immunogenicity of a killed Leishmania vaccine with saponin adjuvant in dogs.

Cellular and humoral immune responses of dogs to a candidate vaccine, composed of Leishmania braziliensis promastigote protein plus saponin as adjuvant, have been investigated as a pre-requisite to understanding the mechanisms of immunogenicity against canine visceral leishmaniasis (CVL). The candidate vaccine elicited strong antigenicity related to the increases of anti- Leishmania IgG isotypes, together with higher levels of lymphocytes, particularly of circulating CD8 + T-lymphocytes and Leishmania chagasi antigen-specific CD8 + T-lymphocytes. As indicated by the intense cell proliferation and increased nitric oxide production during in vitro stimulation by L. chagasisoluble antigens, the candidate vaccine elicited an immune activation status potentially compatible with effective control of the etiological agent of CVL

A representação social do ser adolescente: um passo decisivo na promoção da saúde The social representation to be adolescent: a decisive step to health promotion

Este artigo aborda a adolescência de forma original: o sentimento que o adolescente possui sobre si mesmo, seus valores e competência. Apresenta os resultados de um inquérito epidemiológico que investiga o autoconceito e a auto-estima de 1.686 adolescentes escolares das escolas públicas e particulares de São Gonçalo, município do Estado do Rio de Janeiro. Objetiva conhecer a representação social que esses adolescentes fazem de si próprios. Utiliza-se a técnica denominada "teoria do núcleo central" como arcabouço metodológico. Os resultados indicam que os adolescentes têm uma visão muito positiva de si próprios, conjugando a idéia de alegria/bom humor/extroversão e satisfação com o corpo, a despeito da visão que os adultos e a sociedade em geral têm deles. A partir disso, conclui-se que a otimista visão de si do adolescente precisa ser reconhecida e implementada nas estratégias de promoção da saúde, prevenção e atenção dos agravos à saúde.<br>This article approaches the adolescence in an original perspective: the feeling that the adolescent possesses on himself, the values and competence. It is a survey that investigates the self-concept and self esteem of 1.686 adolescents studying in private and public schools in a municipal district of Rio de Janeiro, São Gonçalo. It aims to know the social representation that adolescents do about themselves. As approach methodological the technique used is "theory of the central nucleus". The results indicate that the adolescents have the positive vision of themselves, conjugating the idea of happiness/good mood and satisfaction with the body, in spite of the vision that the adults and the society in general have of them. The optimist self vision of the adolescents need to be recognized and implemented in the strategies of promotion of the health, prevention and attention to the health