The effects of Facebook and Instagram on the 2020 election: A deactivation experiment.

We study the effect of Facebook and Instagram access on political beliefs, attitudes, and behavior by randomizing a subset of 19,857 Facebook users and 15,585 Instagram users to deactivate their accounts for 6 wk before the 2020 U.S. election. We report four key findings. First, both Facebook and Instagram deactivation reduced an index of political participation (driven mainly by reduced participation online). Second, Facebook deactivation had no significant effect on an index of knowledge, but secondary analyses suggest that it reduced knowledge of general news while possibly also decreasing belief in misinformation circulating online. Third, Facebook deactivation may have reduced self-reported net votes for Trump, though this effect does not meet our preregistered significance threshold. Finally, the effects of both Facebook and Instagram deactivation on affective and issue polarization, perceived legitimacy of the election, candidate favorability, and voter turnout were all precisely estimated and close to zero.

Digging deeper into colonial palaeontological practices in modern day Mexico and Brazil.

Scientific practices stemming from colonialism, whereby middle- and low-income countries supply data for high-income countries and the contributions of local expertise are devalued, are still prevalent today in the field of palaeontology. In response to these unjust practices, countries such as Mexico and Brazil adopted protective laws and regulations during the twentieth century to preserve their palaeontological heritage. However, scientific colonialism is still reflected in many publications describing fossil specimens recovered from these countries. Here, we present examples of 'palaeontological colonialism' from publications on Jurassic-Cretaceous fossils from NE Mexico and NE Brazil spanning the last three decades. Common issues that we identified in these publications are the absence of both fieldwork and export permit declarations and the lack of local experts among authorships. In Mexico, access to many fossil specimens is restricted on account of these specimens being housed in private collections, whereas a high number of studies on Brazilian fossils are based on specimens illegally reposited in foreign collections, particularly in Germany and Japan. Finally, we outline and discuss the wider academic and social impacts of these research practices, and propose exhaustive recommendations to scientists, journals, museums, research institutions and government and funding agencies in order to overcome these practices.

Platelets modulate CD4+ T-cell function in COVID-19 through a PD-L1 dependent mechanism.

Severe COVID-19 is associated with a systemic inflammatory response and progressive CD4+ T-cell lymphopenia and dysfunction. We evaluated whether platelets might contribute to CD4+ T-cell dysfunction in COVID-19. We observed a high frequency of CD4+ T cell-platelet aggregates in COVID-19 inpatients that inversely correlated with lymphocyte counts. Platelets from COVID-19 inpatients but not from healthy donors (HD) inhibited the upregulation of CD25 expression and tumour necrosis factor (TNF)-α production by CD4+ T cells. In addition, interferon (IFN)-γ production was increased by platelets from HD but not from COVID-19 inpatients. A high expression of PD-L1 was found in platelets from COVID-19 patients to be inversely correlated with IFN-γ production by activated CD4+ T cells cocultured with platelets. We also found that a PD-L1-blocking antibody significantly restored platelets' ability to stimulate IFN-γ production by CD4+ T cells. Our study suggests that platelets might contribute to disease progression in COVID-19 not only by promoting thrombotic and inflammatory events, but also by affecting CD4+ T cells functionality.

Hydroxychloroquine / azithromycin in COVID-19: The association between time to treatment and case fatality rate.

BACKGROUND: Currently, there is no formally accepted pharmacological treatment for COVID-19. MATERIALS AND METHODS: We included COVID-19 outpatients of a Peruvian primary care center from Lima, Peru, who were treated between April 30 - September 30, 2020, with hydroxychloroquine and azithromycin. Logistic regression was applied to determine factors associated with case-fatality rate. RESULTS: A total of 1265 COVID-19 patients with an average age of 44.5 years were studied. Women represented 50.1% of patients, with an overall 5.9 symptom days, SpO2 97%, temperature of 37.3 °C, 41% with at least one comorbidity and 96.1% one symptom or sign. No patient treated within the first 72 h of illness died. The factors associated with higher case fatality rate were age (OR = 1.06; 95% CI 1.01-1.11, p = 0.021), SpO2 (OR = 0.87; 95% CI 0.79-0.96, p = 0.005) and treatment onset (OR = 1.16; 95% CI 1.06-1.27, p = 0.002), being the latter the only associated in the multivariate analysis (OR = 1.18; 95% CI 1.05-1.32, p = 0.005). 0.6% of our patients died. CONCLUSIONS: The case fatality rate in COVID-19 outpatients treated with hydroxychloroquine/azithromycin was associated with the number of days of illness on which treatment was started.

Neumonía grave en la comunidad: ¿cuándo pensar en SAMR-AC? / Severe community pneumonia: when to think about CA-MRSA

ntroducción: Aunque la incidencia de neumonía adquirida en la comunidad (NAC) por Staphylococcus aureus meticilino-resistente adquirido en la comunidad (SAMR-AC) es inferior al 10%, por su elevada mortalidad debe considerarse en los pacientes graves.Objetivo: Identificar factores de riesgo asociados con SAMR-AC en pacientes con NAC grave. Material y métodos: Estudio observacional, retrospectivo, que analizó pacientes con NAC con diagnóstico etiológico ingresados en terapia intensiva en un hospital público entre 2006 y 2017.Resultados: Se incluyeron 250 episodios de NAC, 53 por SAMR-AC y 197 por otros agentes. Los pacientes con SAMR fueron más jóvenes (35,6±13,4 vs 43,1±12,4, p<0,001) y mostraron mayores tasas de infecciones de piel y estructuras relacionadas (IPER) (58,4% vs 2,0%, p<0,001), empiema (15,9% vs 5,0%, p=0,006), compromiso radiológico bilateral (81,1% vs 36,0%, p<0,001), promedio de score APACHE II basal (16,7±3,8 vs 13,2±4,3, p<0,001) y requerimiento de ventilación mecánica (VM) (33,9 vs 17,6 p=0,009). La tasa de mortalidad fue significativamente mayor para los pacientes con SAMR-AC (35,8% vs 11,1%, p<0,001). Las variables que se asociaron con SAMR-AC fueron IPER (OR 67,99, IC 5% 21,94-210,65), compromiso radiológico bilateral (OR 7,63, IC 95% 3,67-16,11), scoreAPACHE II ≥ 15 (OR 4,37, IC 95% 2,08-9,16), edad ≤ 35 años RESUMENTRABAJO COMPLETO(OR 3,60, IC 95% 1,77-7,29), empiema (OR 3,32, IC 95% 1,24-8,10) y VM (OR 2,85, IC 95% 1,36-5,86). Conclusión: En pacientes con NAC grave, la presencia de IPER, compromiso radiológico bilateral, score APACHE II ≥ 15, edad ≤ 35 años, empiema y VM se asociaron significativamente con mayor probabilidad de infección por SAMR-AC

ntroduction: Despite the incidence of community-acquired pneumonia (CAP) due to community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) being less than 10%, its presence should be considered in critical patients because of its high rate of mortality.Objectives: To identify risk factors associated with CA-MRSA in patients with severe CAP.Materials and method: A retrospective, observational study analysed episodes of etiological diagnosis in patients admitted in Intensive Care Unit in a public hospital between 2006 and 2017.Results: 250 episodes of NAC were included, among which 53 were caused by SAMR-AC and 197 by other agents. Patients with MRSA were the youngest (35.6±13.4 vs 43.1±12.4, p<0.001), and showed higher rates of skin and skin-structure infections (SSSI) (58.4% vs 2.0%, p<0.001), empyema (15.9% vs 5.0%, p=0.006), bilateral radiological compromise (81.1% vs 36.0%, p<0.001), average base-line APACHE II score (16.7±3.8 vs 13.2±4.3, p<0.001) and mechanical ventilation requirement rate (MV) (33.9 vs 17.6 p=0.009). The mortality rate was significantly higher than the one in CA-MRSA patients (35.8% vs 11.1%, p<0.001). The variables associated with CA-MRSA were SSSI (OR 67.99, IC 5% 21.94-210.65), bilateral radiological compromise (OR 7.63, IC 95% 3.67-16.11), APACHE II score ≥ 15 (OR 4.37, IC 95% 2.08-9.16), age ≤35 years (OR 3.60, IC 95% 1.77-7,29), empyema (OR 3.32, IC 95% 1.24-8.10) and MV (OR 2.85, IC 95% 1.36-5.86).Conclusion: The presence of SSSI, bilateral radiological compromise, APACHE II score ≥ 15, age ≤35 years, empyema and MV in patients with severe CAP was largely associated with higher probability of CA-MRSA infection

Sinus pericranii, petrosquamosal sinus and extracranial sigmoid sinus: Anatomical variations to consider during a retroauricular approach.

Lateral and sigmoid sinus malformations are uncommon and dangerous anatomical variations that surgeons may encounter when performing a retroauricular approach. We report three cases of rare temporal bone venous sinus anomalies seen in patients who underwent cochlear implant surgery. The first patient had a diagnosis of CHARGE syndrome and presented a bilateral persistent petrosquamosal sinus with sigmoid sinus agenesis, which made mastoidectomy for cochlear implantation difficult. The second patient presented an anomalous venous lake in the occipital region, which communicated the left dural venous sinuses with a conglomerate of pericranial vessels in the left nuchal region, also consistent with left sinus pericranii. The third patient presented with an extracranial sigmoid sinus that produced a troublesome bleeding immediately after the muscular-periosteal flap incision was performed.

Tiarajudens eccentricus and Anomocephalus africanus, two bizarre anomodonts (Synapsida, Therapsida) with dental occlusion from the Permian of Gondwana.

Anomodontia was a highly successful tetrapod clade during the Permian and the Triassic. New morphological information regarding two bizarre basal anomodonts is provided and their palaeoecological significance is explored. The osteology of the recently discovered Tiarajudens eccentricus Cisneros et al. 2011, from the Brazilian Permian, is described in detail. The taxon exhibits unusual postcranial features, including the presence of gastralia. Additional preparation and computed tomography scans of the holotype of Anomocephalus africanus Modesto et al. 1999 discovered in the Karoo Basin of South Africa allow a reappraisal of this genus. Anomocephalus is similar to Tiarajudens with regard to several traits, including a battery of large, transversally expanded, palatal teeth. Molariform teeth are present in the mandible of the African taxon, providing additional insight into the function of the earliest tooth-occlusion mechanism known in therapsids. At least two waves of tooth replacement can be recognized in the palate of Anomocephalus. The outsized, blade-like caniniforms of the herbivorous Tiarajudens allow several non-exclusive ecological interpretations, among which we favour intraspecific display or combat. This behaviour was an alternative to the head-butting practised by the contemporary dinocephalians. Combat specializations that are considered typical of Cenozoic herbivores likely evolved during the Middle Permian, at the time the first communities with diverse, abundant tetrapod herbivores were being assembled.

Staphylococcus aureus meticilino resistente adquirido en la comunidad: una nueva amenaza / Community acquired methicillin-resistant Staphylococcus: A new threat

Objetivos: Conocer la frecuencia de Staphylococcus aureus meticilino resistente adquirido en la comunidad (SAMR-AC) en neumonía adquirida en la comunidad (NAC); examinar sus características clínicas - evolutivas y analizar factores de riesgo. Pacientes, material y métodos: Estudio retrospectivo, descriptivo, observacional, realizado en una unidad de cuidados intensivos respiratorios entre 2006 y 2012. Resultados: Se evaluaron 180 pacientes con NAC con diagnóstico etiológico. Etiologías más frecuentes: Streptococcus pneumoniae (50.5%), Haemophillus influenzae (18.3%) ySAMR-AC (12.2%, 22 casos). La neumonía por SAMR-AC se presentó en individuos jóvenes, mayoritariamente hombres. En el 81.8% de los casos el foco primario fue infección de piel y estructuras relacionadas (IPER), 95.4% presentó criterios clínicos de sepsis, 72.7% tuvo compromiso radiológico bilateral y 45.5% desarrolló derrame pleural. El 40.9% requirió ventilación mecánica y el 45.4% utilizó drogas vasoactivas. El 81.8% de los pacientes no alcanzó criterios de estabilidad clínica al cabo de la primer semana y la mortalidad fue del 36.3%, significativamente superior al resto de los microorganismos (8.8%, p<0,001). Los factores clínicos asociados con mayor riesgo de SAMR-AC fueron la presencia de IPER concomitante, compromiso radiológico bilateral, presencia de criterios clínicos de sepsis, edad inferior a 30 años y requerimiento de drogas vasoactivas. Los factores que se asociaron con mortalidad en NAC fueron la etiología por SAMR-AC y el compromiso radiológico bilateral. Conclusiones: La neumonía por SAMR-AC es una patología emergente, asociada a elevada morbimortalidad. Debe ser considerada en pacientes jóvenes, con presencia concomitante de IPER, compromiso radiológico bilateral, criterios clínicos de sepsis o necesidad de drogas vasoactivas.

Objectives: To know the incidence of Community Acquired Pneumonia (CAP) caused by Methicillin Resistant Sthaphylococcus aureus (MRSA), to examine their clinical and developmental characteristics and to analyze risk factors. Materials and Methods: Retrospective, descriptive and observational study carried out at a Respiratory Intensive Care Unit, between 2006 and 2012. Results: 180 patients with etiologic diagnosis of CAP were evaluated. The most common causes were Streptococcus pneumoniae (50.5%), Haemophillus influenzae (18.3%) and MRSA (12.2%, 22 cases). Community Acquired MRSA (CA-MRSA) pneumonia was present in young people, especially in male. In 81.8% of the cases, skin and related structure infections (SRSI) were the primary focus, 95.4% presented clinical criteria of sepsis, 72.7% had bilateral radiology involvement and 45.5% developed pleural effusion. 40.9% needed mechanical ventilation and 45.4% used vasoactive drugs. Clinical stability at the first week was not reached in 81.8% and mortality rate was 36.6%, significantly higher than for pneumonia caused by other microorganisms (8.8% p<0,001). Clinical factors related with high risk of CA-MRSA pneumonia were the concomitant presence of SRSI, bilateral radiology involvement, clinical criteria of sepsis, age <30 years old and need for vasoactive drugs. Factors related to CAP mortality were CA-MRSA aetiology and bilateral radiology involvement. Conclusions: CA-MRSA pneumonia is an emergent disease with high morbidity and mortality. It must be considered in young patients, with SRSI, bilateral radiology involvement, clinical criteria of sepsis or intake of vasoactive drugs.

Staphylococcus aureus meticilino resistente adquirido en la comunidad: una nueva amenaza / Community acquired methicillin-resistant Staphylococcus: A new threat

Objetivos: Conocer la frecuencia de Staphylococcus aureus meticilino resistente adquirido en la comunidad (SAMR-AC) en neumonía adquirida en la comunidad (NAC); examinar sus características clínicas - evolutivas y analizar factores de riesgo. Pacientes, material y métodos: Estudio retrospectivo, descriptivo, observacional, realizado en una unidad de cuidados intensivos respiratorios entre 2006 y 2012. Resultados: Se evaluaron 180 pacientes con NAC con diagnóstico etiológico. Etiologías más frecuentes: Streptococcus pneumoniae (50.5%), Haemophillus influenzae (18.3%) ySAMR-AC (12.2%, 22 casos). La neumonía por SAMR-AC se presentó en individuos jóvenes, mayoritariamente hombres. En el 81.8% de los casos el foco primario fue infección de piel y estructuras relacionadas (IPER), 95.4% presentó criterios clínicos de sepsis, 72.7% tuvo compromiso radiológico bilateral y 45.5% desarrolló derrame pleural. El 40.9% requirió ventilación mecánica y el 45.4% utilizó drogas vasoactivas. El 81.8% de los pacientes no alcanzó criterios de estabilidad clínica al cabo de la primer semana y la mortalidad fue del 36.3%, significativamente superior al resto de los microorganismos (8.8%, p<0,001). Los factores clínicos asociados con mayor riesgo de SAMR-AC fueron la presencia de IPER concomitante, compromiso radiológico bilateral, presencia de criterios clínicos de sepsis, edad inferior a 30 años y requerimiento de drogas vasoactivas. Los factores que se asociaron con mortalidad en NAC fueron la etiología por SAMR-AC y el compromiso radiológico bilateral. Conclusiones: La neumonía por SAMR-AC es una patología emergente, asociada a elevada morbimortalidad. Debe ser considerada en pacientes jóvenes, con presencia concomitante de IPER, compromiso radiológico bilateral, criterios clínicos de sepsis o necesidad de drogas vasoactivas. (AU)

Objectives: To know the incidence of Community Acquired Pneumonia (CAP) caused by Methicillin Resistant Sthaphylococcus aureus (MRSA), to examine their clinical and developmental characteristics and to analyze risk factors. Materials and Methods: Retrospective, descriptive and observational study carried out at a Respiratory Intensive Care Unit, between 2006 and 2012. Results: 180 patients with etiologic diagnosis of CAP were evaluated. The most common causes were Streptococcus pneumoniae (50.5%), Haemophillus influenzae (18.3%) and MRSA (12.2%, 22 cases). Community Acquired MRSA (CA-MRSA) pneumonia was present in young people, especially in male. In 81.8% of the cases, skin and related structure infections (SRSI) were the primary focus, 95.4% presented clinical criteria of sepsis, 72.7% had bilateral radiology involvement and 45.5% developed pleural effusion. 40.9% needed mechanical ventilation and 45.4% used vasoactive drugs. Clinical stability at the first week was not reached in 81.8% and mortality rate was 36.6%, significantly higher than for pneumonia caused by other microorganisms (8.8% p<0,001). Clinical factors related with high risk of CA-MRSA pneumonia were the concomitant presence of SRSI, bilateral radiology involvement, clinical criteria of sepsis, age <30 years old and need for vasoactive drugs. Factors related to CAP mortality were CA-MRSA aetiology and bilateral radiology involvement. Conclusions: CA-MRSA pneumonia is an emergent disease with high morbidity and mortality. It must be considered in young patients, with SRSI, bilateral radiology involvement, clinical criteria of sepsis or intake of vasoactive drugs. (AU)

Carnivorous dinocephalian from the Middle Permian of Brazil and tetrapod dispersal in Pangaea.

The medial Permian (~270-260 Ma: Guadalupian) was a time of important tetrapod faunal changes, in particular reflecting a turnover from pelycosaurian- to therapsid-grade synapsids. Until now, most knowledge on tetrapod distribution during the medial Permian has come from fossils found in the South African Karoo and the Russian Platform, whereas other areas of Pangaea are still poorly known. We present evidence for the presence of a terrestrial carnivorous vertebrate from the Middle Permian of South America based on a complete skull. Pampaphoneus biccai gen. et sp. nov. was a dinocephalian "mammal-like reptile" member of the Anteosauridae, an early therapsid predator clade known only from the Middle Permian of Russia, Kazakhstan, China, and South Africa. The genus is characterized, among other features, by postorbital bosses, short, bulbous postcanines, and strongly recurved canines. Phylogenetic analysis indicates that the Brazilian dinocephalian occupies a middle position within the Anteosauridae, reinforcing the model of a global distribution for therapsids as early as the Guadalupian. The close phylogenetic relationship of the Brazilian species to dinocephalians from South Africa and the Russian Platform suggests a closer faunistic relationship between South America and eastern Europe than previously thought, lending support to a Pangaea B-type continental reconstruction.

Dental occlusion in a 260-million-year-old therapsid with saber canines from the Permian of Brazil.

Anomodonts, a group of herbivorous therapsid "mammal-like reptiles," were the most abundant tetrapods of the Permian. We present a basal anomodont from South America, a new taxon that has transversally expanded palatal teeth and long saber canines. The function of the saber teeth is unknown, but probable uses include deterring attack from predators and intraspecific display or combat. The complex palatal teeth were used to process high-fiber food and represent early evidence of dental occlusion in a therapsid. This discovery provides new insight into the evolution of heterogeneous dentition in therapsids and broadens our understanding of ecological interactions at the end of the Paleozoic.

Spondarthritis in the triassic.

BACKGROUND: The evidence of several forms of arthritis has been well documented in the fossil record. However, for pre-Cenozoic vertebrates, especially regarding reptiles, this record is rather scarce. In this work we present a case report of spondarthritis found in a vertebral series that belonged to a carnivorous archosaurian reptile from the Lower Triassic (∼245 million years old) of the South African Karoo. METHODOLOGY/PRINCIPAL FINDINGS: Neutron tomography confirmed macroscopic data, revealing the ossification of the entire intervertebral disc space (both annulus fibrosus and nucleus pulposus), which supports the diagnosis of spondarthritis. CONCLUSIONS/SIGNIFICANCE: The presence of spondarthritis in the new specimen represents by far the earliest evidence of any form of arthritis in the fossil record. The present find is nearly 100 million years older than the previous oldest report of this pathology, based on a Late Jurassic dinosaur. Spondarthritis may have indirectly contributed to the death of the animal under study.

Terapia intensiva y sida: cambios en la era del TARGA / Intensive care and AIDS: changes in the era of HAART

Analizar las características de la población de pacientes HIV positivos bajo TARGA o con CD4 mayor a 200 mm3 admitidos en una unidad de cuidados intensivos, en comparación con la población de pacientes HIV positivos sin control ni tratamiento.

Neumonía aguda de la comunidad en pacientes HIV positivos: características clínicas y evolución / Community acute pnemonie in HIV positive patients

El objetivo del trabajo es conocer las características de NAC en pacientes hospitalizados con infección por HIV y compararlas con aquellas observadas en pacientes HIV negativos

Neumonía aguda de la comunidad en pacientes HIV positivos: características clínicas y evolución / Community acute pnemonie in HIV positive patients

El objetivo del trabajo es conocer las características de NAC en pacientes hospitalizados con infección por HIV y compararlas con aquellas observadas en pacientes HIV negativos(AU)