Search for subsolar-mass black hole binaries in the second part of Advanced LIGO’s and Advanced Virgo’s third observing run

We describe a search for gravitational waves from compact binaries with at least one component with mass 0.2 M⊙–1.0 M⊙ and mass ratio q ≥ 0.1 in Advanced LIGO and Advanced Virgo data collected between 1 November 2019, 15:00 UTC and 27 March 2020, 17:00 UTC. No signals were detected. The most significant candidate has a false alarm rate of 0.2yr−1 ⁠. We estimate the sensitivity of our search over the entirety of Advanced LIGO’s and Advanced Virgo’s third observing run, and present the most stringent limits to date on the merger rate of binary black holes with at least one subsolar-mass component. We use the upper limits to constrain two fiducial scenarios that could produce subsolar-mass black holes: primordial black holes (PBH) and a model of dissipative dark matter. The PBH model uses recent prescriptions for the merger rate of PBH binaries that include a rate suppression factor to effectively account for PBH early binary disruptions. If the PBHs are monochromatically distributed, we can exclude a dark matter fraction in PBHs fPBH ≳ 0.6 (at 90% confidence) in the probed subsolar-mass range. However, if we allow for broad PBH mass distributions we are unable to rule out fPBH = 1. For the dissipative model, where the dark matter has chemistry that allows a small fraction to cool and collapse into black holes, we find an upper bound fDBH < 10−5 on the fraction of atomic dark matter collapsed into black holes

Análisis Plural, segundo semestre 2021: A medio trecho, AMLO y la 4T

Con este número termina la primera época de la colección Análisis Plural y se ofrece un artículo especial para reflexionar sobre lo que ha significado esta publicación desde su fundación, hace 33 años. En lo correspondiente al análisis del segundo semestre del 2021, los artículos llevan a la reflexión sobre los aspectos positivos y negativos de la gestión presidencial de Andrés Manuel López Obrador; se abordan también los rasgos de la política educativa y económica; el caso de los Papeles de Pandora y los resultados de la iniciativa que eliminó el outsourcing; ante la decisión de cerrar las escuelas por la pandemia se analizan los dilemas de la enseñanza remota; se plasman las causas de la migración y las estrategias que miles de familias aplican para garantizar su tránsito por México; con relación al cambio climático se expone la poca relevancia que el gobierno de la 4T ha manifestado sobre esta problemática y, para cerrar el análisis se ofrece una crónica de la resistencia de Temacapulín, Acasico y Palmarejo, para salvar su territorio ante la construcción de la presa El Zapotillo que amenazó con inundar sus pueblos.ITESO, A.C

Enhancing self-regulation and approaches to learning in first-year college students: a narrative-based programme assessed in the Iberian Peninsula

A programme to enhance first-year college students’ self-regulated learning strategies is proposed and assessed in two samples, one from the University of Oviedo (Spain) and the other from the University of Minho (Portugal). Each sample was divided into two groups (experimental and control). The Spanish sample comprised 44 students in the experimental group and 40 in the control group, whereas in the Portuguese sample, the number of students was 48 and 44, respectively. The narrativebased intervention programme is organised around a set of fictional letters from a first-year college student in which he reports his own academic experiences. Each letter focuses on a learning strategy as an opportunity to teach and enhance the students’ deep approaches to learning and their self-regulated learning processes. In both samples, findings confirm the programme efficacy to teach efficient learning strategies and to promote self-regulation. Implications for college students and for teaching are discussed