Fermionic field perturbations of a three-dimensional Lifshitz black hole in conformal gravity

We study the propagation of massless fermionic fields in the background of a three-dimensional Lifshitz black hole, which is a solution of conformal gravity. The black hole solution is characterized by a null dynamical exponent. Then, we compute analytically the quasinormal modes, the area spectrum, and the absorption cross section for fermionic fields. The analysis of the quasinormal modes shows that the fermionic perturbations are stable in this background. The area and entropy spectrum are evenly spaced. At the low frequency limit, it is observed that there is a range of values of the angular momentum of the mode that contributes to the absorption cross section, whereas it vanishes at the high frequency limit. In addition, by a suitable change of variables a gravitational soliton can also be obtained and the stability of the quasinormal modes are studied and ensured.Comment: 14 pages; 3 figures. arXiv admin note: text overlap with arXiv:1407.639

Nivel de vacilación frente a la vacuna contra COVID-19 en una zona urbano marginal de Lima: Level of hesitancy towards the COVID-19 vaccine in a marginal urban area of Lima

Objective: To determine the frequency and the factors associated with the refusal of vaccination against COVID-19 in the marginal urban area of Lima. Materials and methods: Quantitative, observational and descriptive cross-sectional study carried out in the year 2021. The population was made up of residents of the "Nueva Juventud" Human Settlement located in the district of Carabayllo, in the North of Lima. The study variable was the refusal of vaccination against COVID-19. Results: 405 people of both sexes participated with a median age of 30 years (Q1: 23, Q3: 42, Interquartile range: 19). Of the sample, 47.9% (n=194) were between 18 and 29 years old, 62% (n=251) corresponding to the female sex, most of the participants had a higher education degree and were users of the Comprehensive Health Insurance (SIS). 64% (n=259) reported a history of COVID-19. Regarding the level of hesitation, in 21.5% (n=87) it was low, 48.6% (n=197) moderate and 29.9% (n=121) presented a high level of hesitation. The high level of hesitation occurred in a greater proportion in older residents (p<0.001) and people with a lower level of education (p=0.001). The lowest percentage of high hesitation was presented in users of the SIS (p=0.005). Conclusions: There is a predominance of moderate and high level of hesitation against the COVID-19 vaccine. High hesitation was greater in older people and in those with a lower level of education. It is recommended to improve communication strategies regarding the benefits of the COVID-19 vaccine.  Keywords: Vaccination Refusal; COVID-19; COVID-19 Vaccines; Peru (Source: MeSH, NLM).Objetivo: Determinar la frecuencia y los factores asociados a la negativa de vacunación contra el COVID-19 en una zona urbano marginal de Lima. Materiales y métodos: Estudio cuantitativo, observacional y descriptivo transversal realizado en el año 2021. La población estuvo conformada por residentes del Asentamiento Humano “Nueva Juventud” ubicado en el distrito de Carabayllo, Norte de Lima. La variable de estudio fue la negativa de vacunación contra el COVID-19. Resultados: Participaron 405 personas de ambos sexos con una edad mediana de 30 años (Q1: 23, Q3: 42, Rango intercuartilar:19). De la muestra, el 47,9% (n=194) tenían entre 18 a 29 años de edad, el 62% (n=251) correspondiente al sexo femenino, la mayoría de los participantes tenían grado de instrucción superior y eran usuarios del Seguro Integral de Salud (SIS). El 64% (n=259) reportaron antecedente de COVID-19. Respecto al nivel de vacilación, en el 21,5% (n=87) fue baja, 48,6% (n=197) moderada y el 29,9% (n=121) presentó alto nivel de vacilación. El nivel vacilación alta se presentó en mayor proporción en residentes de mayor edad (p<0,001) y las personas con menor grado de instrucción (p=0,001). El menor porcentaje de vacilación alta se presentó en usuarios del SIS (p=0,005). Conclusiones: Existe un predominio de nivel de vacilación moderada y alta frente a la vacuna contra la COVID-19. La vacilación alta fue mayor en las personas de mayor edad y en aquellos con menor grado de instrucción. Se recomienda mejorar las estrategias de comunicación respecto a los beneficios de la vacuna contra el COVID-19. Palabras clave: Negativa a la Vacunación; COVID-19; Perú (Fuente: DeCS, BIREME)

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

Background Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)