Constraining a companion of the galactic center black hole, Sgr A*

We use 23 years of astrometric and radial velocity data on the orbit of the star S0-2 to constrain a hypothetical intermediate-mass black hole orbiting the massive black hole Sgr A* at the Galactic center. The data place upper limits on variations of the orientation of the stellar orbit (inclination, nodal angle, and pericenter) at levels between 0.02 and 0.07 degrees per year. We use a combination of analytic estimates and full numerical integrations of the orbit of S0-2 in the presence of a black-hole binary. For a companion IMBH whose semi-major axis $a_c$ is larger than that of S0-2 (1020 a.u.), we find that in the region between 1000 and 4000 a.u., a companion black hole with mass $m_c$ between $10^3$ and $10^5 M_\odot$ is excluded, with a boundary behaving as $a_c \sim m_c^{1/3}$. For a companion with $a_c < 1020$ a.u., we find that a black hole with mass between $10^3$ and $10^5 \, M_\odot$ is again excluded, with a boundary behaving as $a_c \sim m_c^{-1/2}$. These bounds arise from quadrupolar perturbations of the orbit of S0-2. However, significantly stronger bounds on the mass of an inner companion arise from the fact that the location of S0-2 is measured relative to the bright emission of Sgr A*. As a consequence, that separation is perturbed by the ``wobble'' of Sgr A* about the center of mass between it and the companion, leading to ``apparent'' perturbations of S0-2's orbit that also include a dipole component. The result is a set of bounds as small as $400 \, M_\odot$ at 200 a.u.; the numerical simulations suggest a bound from these effects varying as $a_c \sim m_c^{-1}$. We compare and contrast our results with those from a recent analysis by the GRAVITY collaboration.Comment: 9 pages, 4 figure

Neural correlates and determinants of approach-avoidance conflict in the prelimbic prefrontal cortex

The recollection of environmental cues associated with threat or reward allows animals to select the most appropriate behavioral responses. Neurons in the prelimbic cortex (PL) respond to both threat-and reward-associated cues. However, it remains unknown whether PL regulates threat-avoidance vs. reward-approaching responses when an animals’ decision depends on previously associated memories. Using a conflict model in which male Long-Evans rats retrieve memories of shock and food-paired cues, we observed two distinct phenotypes during conflict: I) rats that continued to press a lever for food (Pressers); and ii) rats that exhibited a complete suppression in food seeking (Non-pressers). Single-unit recordings revealed that increased risk-taking behavior in Pressers is associated with persistent food-cue responses in PL, and reduced spontaneous activity in PL glutamatergic (PLGLUT) neurons during conflict. Activating PLGLUT neurons in Pressers attenuated foodseeking responses in a neutral context, whereas inhibiting PLGLUT neurons in Non pressers reduced defensive responses and increased food approaching during conflict. Our results establish a causal role for PLGLUT neurons in mediating individual variability in memory-based risky decision making by regulating threat-avoidance vs. reward-approach behaviors.Fil: Fernandez Leon, Jose Alberto. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires; Argentina. University of Texas Health Science Center at Houston; Estados UnidosFil: Engelke, Douglas S.. University of Texas Health Science Center at Houston; Estados UnidosFil: Aquino Miranda, Guillermo. University of Texas Health Science Center at Houston; Estados UnidosFil: Goodson, Alexandria. University of Texas Health Science Center at Houston; Estados Unidos. Rice University; Estados UnidosFil: Rasheed, María N.. University of Texas Health Science Center at Houston; Estados UnidosFil: Do Monte, Fabricio H.. University of Texas Health Science Center at Houston; Estados Unidos. Rice University; Estados Unido

Sterically Induced Binding Selectivity of Single m-Terphenyl Isocyanide Ligands

Sterically encumbering m-terphenyl isocyanides are a class of metal-binding group that foster low-coordinate metal-center environments in coordination chemistry by exerting considerable intermolecular steric pressures between neighboring ligands. In the context of metal surfaces, the encumbering steric properties of the m-terphenyl isocyanides are shown to weaken the interaction between the metal-binding group and a planar substrate, leading to a preference for molecular adsorption at sites with convex curvature, such as the step edges and herringbone elbow sites on Au(111). Here, we investigate the site-selective binding of individual m-terphenyl isocyanide ligands on a Au(111) surface through scanning tunneling microscopy (STM) and inelastic electron tunneling spectroscopy (IETS). The site-dependent steric pressure alters the vibrational fingerprint of the m-terphenyl isocyanides, which is characterized with single-molecule precision through joint experimental and theoretical approaches. This study for the first time provides molecular-level insights into the steric-pressure-enabled surface binding selectivity as well as its effect on the chemical properties of individual m-terphenyl isocyanide ligands, thereby highlighting the potential to control the physical and chemical properties of metal surfaces through tailored ligand design

Violência obstétrica na perspectiva dos profissionais de enfermagem envolvidos na assistência ao parto

Objetivo: Avaliar o conhecimento de profissionais de enfermagem envolvidos na assistência ao parto sobre violência obstétrica. Método: Estudo de natureza qualitativa em que participaram da pesquisa enfermeiros(as) que atenderam aos critérios de inclusão: ser enfermeiro(a) da maternidade lócus do estudo, possuir graduação por um período mínimo de seis meses e trabalhar diretamente na assistência ao parto. Realizou-se entrevista semiestruturada, utilizando-se do critério de saturação dos dados para encerramento da coleta. Para a organização dos resultados foi utilizada a técnica de análise de conteúdo. Resultados: Os enfermeiros participantes apontaram quais as técnicas, práticas e manobras que consideram ser violência obstétrica. Foi identificado diante das experiências dos profissionais que a ocorrência da violência obstétrica ainda é bastante praticada. Percebeu-se que profissionais da enfermagem possuem conhecimentos acerca da violência obstétrica, como também as suas práticas. Conclusão: Aponta-se assim a necessidade de que tais agravos, em sua assistência, possam ser reduzidos a partir de ações estratégicas e protocolos assistenciais.Objective: Evaluate the knowledge of nursing professionals involved in childbirth care about obstetric violence. Method: This was a qualitative study in which nurses met the following inclusion criteria: being a nurse in the maternity hospital of the study, graduating for a minimum period of six months and working directly in childbirth care. A semi-structured interview was performed using the data saturation criterion to close the collection. For the organization of the results the content analysis technique was used. Results: The participating nurses pointed out the techniques, practices and manoeuvres they consider to be obstetric violence. It was identified from the experiences of professionals that the occurrence of obstetric violence is still quite practiced. It was noticed that nursing professionals have knowledge about obstetric violence, as well as their practices. Conclusion: Thus, it is pointed out that these problems, in their assistance, can be reduced through strategic actions and assistance protocols.Objetivo: Evaluar el conocimiento de profesionales de enfermería involucrados en la asistencia al parto acerca de la violencia obstétrica. Método: Se trata de un estudio cualitativo en que participaron enfermeros que atendieron a los criterios de inclusión: ser enfermero (a) de la maternidad locus del estudio, poseer graduación por un período mínimo de seis meses y trabajar directamente en la asistencia al parto. Se realizó una entrevista semiestructurada, utilizando el criterio de saturación de los datos para el cierre de la recolección. Para la organización de los resultados se utilizó la técnica de análisis de contenido. Resultados: Los enfermeros participantes apuntar cuáles son las técnicas, prácticas y maniobras que consideran ser violencia obstétrica. Fue identificado ante las experiencias de los profesionales que la ocurrencia de la violencia obstétrica todavía es bastante practicada. Se percibió que profesionales de enfermería poseen conocimientos acerca de la violencia obstétrica, así como sus prácticas. Conclusión: Se apunta así la necesidad de que tales agravios, en su asistencia, puedan ser reducidos a partir de acciones estratégicas y protocolos asistenciales

Quatro décadas após a epidemia de HIV/AIDS: conquistas e desafios

Considered a public health problem on a global scale, the HIV/AIDS pandemic has created a great challenge for authorities to develop public health policies. Since its first registered case in the early 1980s, it has been considered an inextinguishable mark on health, society and economic growth. This is an integrative bibliographic review research, the objective of which was established based on the need to list the main discoveries and challenges after the Human Immunodeficiency Virus and Acquired Immunodeficiency Syndrome epidemic that occurred in the 1980s. of 1400 publications with the descriptors defined for the research. In its first registration it was labeled as a virus associated with lymphadenopathy, and in the following year, after the issuance of a report indicating approximately 75 million infected people and around 32 million deaths, the first concerns of public health authorities were established. In 1983, it was discovered that the retrovirus was the cause of AIDS, and in the same year, it was named Human Immunodeficiency Virus (HIV). From this, there was a need to develop a diagnostic method, the Enzyme Immunoassay (EIA) to identify carriers who did not yet show clinical manifestations, that is, the asymptomatic form. To control the progression of the disease and reduce the damage caused by the impairment of the immune system as a result of the infection, at the end of the 80s and 90s, the FDA approved the first drugs, which were used in monotherapy regimens. Due to the high power of replication and mutation of the virus, resistance mechanisms have emerged and new means of protection and treatment have been created. Curing HIV was once considered an unattainable goal, but with the advancement of research and new discoveries, the eradication of the Human Immunodeficiency Virus is an achievable goal. The biggest hope of research points to the use of antibodies and development of vaccines.Considerada un problema de salud pública a escala global, la pandemia del VIH/SIDA ha creado un gran desafío para las autoridades a la hora de desarrollar políticas de salud pública. Desde su primer caso registrado a principios de los años 1980, se ha considerado una marca inextinguible en la salud, la sociedad y el crecimiento económico. Se trata de una investigación de revisión bibliográfica integradora, cuyo objetivo se estableció a partir de la necesidad de enumerar los principales descubrimientos y desafíos posteriores a la epidemia del Virus de Inmunodeficiencia Humana y Síndrome de Inmunodeficiencia Adquirida ocurrida en la década de 1980. De 1400 publicaciones con los descriptores definidos para el investigación. En su primer registro fue etiquetado como un virus asociado a linfadenopatía, y al año siguiente, tras la emisión de un informe que indicaba aproximadamente 75 millones de personas infectadas y alrededor de 32 millones de muertes, se establecieron las primeras preocupaciones de las autoridades de salud pública. En 1983 se descubrió que el retrovirus era la causa del SIDA y ese mismo año se le denominó Virus de Inmunodeficiencia Humana (VIH). A partir de esto, surgió la necesidad de desarrollar un método de diagnóstico, el Inmunoensayo Enzimático (EIA) para identificar a los portadores que aún no presentaban manifestaciones clínicas, es decir, la forma asintomática. Para controlar la progresión de la enfermedad y reducir los daños causados ​​por el deterioro del sistema inmunológico como consecuencia de la infección, a finales de los años 80 y 90, la FDA aprobó los primeros fármacos, que se utilizaban en regímenes de monoterapia. Debido al alto poder de replicación y mutación del virus, han surgido mecanismos de resistencia y se han creado nuevos medios de protección y tratamiento. Curar el VIH alguna vez se consideró un objetivo inalcanzable, pero con el avance de la investigación y los nuevos descubrimientos, la erradicación del Virus de Inmunodeficiencia Humana es un objetivo alcanzable. La mayor esperanza de la investigación apunta al uso de anticuerpos y al desarrollo de vacunas.Considerado um problema de saúde pública em escala global, a pandemia de HIV/AIDS tem gerado grande desafio para as autoridades desenvolverem as políticas públicas de saúde. Desde o seu primeiro caso registrado no início dos anos 80, considerado uma marca inextinguível na saúde, na sociedade e no crescimento econômico. Trata-se de pesquisa de revisão bibliográfica do tipo integrativa, cujo objetivo estabeleceu-se a partir da necessidade de elencar as principais descobertas e desafios após a epidemia do Vírus da Imunodeficiência Humana e Síndrome da Imunodeficiência Adquirida ocorrida na década de 1980. Foram encontradas mais de 1400 publicações com os descritores definidos para a pesquisa. Em seu primeiro registro foi rotulado como vírus associado a linfadenopatia, e já no ano seguinte, após a emissão de um relatório apontando aproximadamente 75 milhões de infectados e cerca de 32 milhões de mortes, e assim se instalou as primeiras preocupações das autoridades de saúde pública. Em 1983 foi desvendado que o retrovírus era o causador da AIDS, e no mesmo ano, foi designado o nome de Vírus da Imunodeficiência Humana (HIV). A partir disto, houve a necessidade de desenvolver um método de diagnóstico, o Imunoensaio Enzimático (EIA) para identificar os portadores que ainda não apresentavam manifestações clínicas, ou seja, a forma assintomática. Para controlar a progressão da doença e reduzir os prejuízos desencadeados pelo comprometimento do sistema imune em decorrência da infecção, no final da década de 80 e 90, a FDA aprovou os primeiros fármacos, que eram utilizados em esquemas de monoterapia. Devido ao alto poder de replicação e mutação do vírus, mecanismos de resistência foram surgindo e novos meios de proteção e tratamento sendo criados. A cura do HIV já foi considerada um objetivo inatingível, mas com o avanço das pesquisas e novas descobertas, a erradicação do vírus da Imunodeficiência Humana é um objetivo alcançável. A maior esperando das pesquisas apontam para a utilização de anticorpos e desenvolvimento de vacinas

Diet-Derived Metabolites and Mucus Link the Gut Microbiome to Fever After Cytotoxic Cancer Treatment

Not all patients with cancer and severe neutropenia develop fever, and the fecal microbiome may play a role. In a single-center study of patients undergoing hematopoietic cell transplant (n = 119), the fecal microbiome was characterized at onset of severe neutropenia. A total of 63 patients (53%) developed a subsequent fever, and their fecal microbiome displayed increased relative abundances of Akkermansia muciniphila, a species of mucin-degrading bacteria (P = 0.006, corrected for multiple comparisons). Two therapies that induce neutropenia, irradiation and melphalan, similarly expanded A. muciniphila and additionally thinned the colonic mucus layer in mice. Caloric restriction of unirradiated mice also expanded A. muciniphila and thinned the colonic mucus layer. Antibiotic treatment to eradicate A. muciniphila before caloric restriction preserved colonic mucus, whereas A. muciniphila reintroduction restored mucus thinning. Caloric restriction of unirradiated mice raised colonic luminal pH and reduced acetate, propionate, and butyrate. Culturing A. muciniphila in vitro with propionate reduced utilization of mucin as well as of fucose. Treating irradiated mice with an antibiotic targeting A. muciniphila or propionate preserved the mucus layer, suppressed translocation of flagellin, reduced inflammatory cytokines in the colon, and improved thermoregulation. These results suggest that diet, metabolites, and colonic mucus link the microbiome to neutropenic fever and may guide future microbiome-based preventive strategies