33 research outputs found
Aerobic power and flight capacity in birds: a phylogenetic test of heart-size hypothesis
Flight capacity is one of the most important innovations in animal evolution; it only evolved in insects, birds, mammals and the extinct pterodactyls. Given that powered flight represents a demanding aerobic activity, an efficient cardiovascular system is essential for the continuous delivery of oxygen to the pectoral muscles during flight. It is well known that the limiting step in the circulation is stroke volume (the volume of blood pumped from the ventricle to the body during each beat), which is determined by the size of the ventricle. Thus, the fresh mass of the heart represents a simple and repeatable anatomical measure of the aerobic power of an animal. Although several authors have compared heart masses across bird species, a phylogenetic comparative analysis is still lacking. By compiling heart sizes for 915 species and applying several statistical procedures controlling for body size and/or testing for adaptive trends in the dataset (e.g. model selection approaches, phylogenetic generalized linear models), we found that (residuals of) heart size is consistently associated with four categories of flight capacity. In general, our results indicate that species exhibiting continuous hovering flight (i.e. hummingbirds) have substantially larger hearts than other groups, species that use flapping flight and gliding show intermediate values, and that species categorized as poor flyers show the smallest values. Our study reveals that on a broad scale, routine flight modes seem to have shaped the energetic requirements of birds sufficiently to be anatomically detected at the comparative level
Comparación de la violencia y agresiones sufridas por el personal de salud durante la pandemia de COVID-19 en Argentina y el resto de Latinoamérica
Objetivos. Explorar la frecuencia e impacto de la violencia contra los trabajadores de salud de Argentina y compararlo con el resto de sus pares de LatinoamĂ©rica en el contexto de la pandemia por COVID-19. Materiales y mĂ©todos. Estudio de corte transversal a travĂ©s de una encuesta electrĂłnica al personal mĂ©dico y no mĂ©dico de LatinoamĂ©rica que desempeño tareas asistenciales desde marzo de 2020. Se utilizĂł una regresiĂłn de Poisson para estimar las Razones de Prevalencia crudas (RP) y ajustadas (RPa) con sus respectivos intervalos de confianza al 95%. Resultados. Un total de 3544 participantes de 19 paĂses respondieron la encuesta; 1992 (56,0%) residĂan en Argentina. Entre los mismos, el 62,9% padeciĂł al menos un hecho de violencia: 97,7% refiriĂł violencia verbal y 11,8% violencia fĂsica. El 41,5% de los agredidos padecieron situaciones de violencia al menos una vez por semana. El personal de salud de Argentina vivenciĂł mĂĄs frecuentemente violencia que los de otros paĂses (62,9% vs. 54,6%, p<0,001), siendo estos eventos mĂĄs habituales y estresantes (p<0,05). AdemĂĄs, refirieron mĂĄs frecuentemente haber considerado cambiar sus tareas asistenciales y/o deseos de abandonar su profesiĂłn (p<0,001). En la regresiĂłn de Poisson, los participantes de
Argentina tuvieron una prevalencia de violencia mayor que los trabajadores de salud de la regiĂłn (14,6%; p<0,001). Conclusiones. ExistiĂł una elevada prevalencia de violencia contra el personal de salud de Argentina durante la pandemia por COVID-19. Estos hechos tuvieron un alto impacto negativo entre quienes los padecieron. Nuestros datos sugieren que, esto podrĂa haber sido mĂĄs frecuente en Argentina respecto de otras regiones del continente
Tumor matrix stiffness promotes metastatic cancer cell interaction with the endothelium
Tumor progression alters the composition and physical properties of the extracellular matrix. Particularly, increased matrix stiffness has profound effects on tumor growth and metastasis. While endothelial cells are key players in cancer progression, the influence of tumor stiffness on the endothelium and the impact on metastasis is unknown. Through quantitative mass spectrometry, we find that the matricellular protein CCN1/CYR61 is highly regulated by stiffness in endothelial cells. We show that stiffnessâinduced CCN1 activates ÎČâcatenin nuclear translocation and signaling and that this contributes to upregulate Nâcadherin levels on the surface of the endothelium, in vitro. This facilitates Nâcadherinâdependent cancer cellâendothelium interaction. Using intravital imaging, we show that knockout of Ccn1 in endothelial cells inhibits melanoma cancer cell binding to the blood vessels, a critical step in cancer cell transit through the vasculature to metastasize. Targeting stiffnessâinduced changes in the vasculature, such as CCN1, is therefore a potential yet unappreciated mechanism to impair metastasis
Tumor matrix stiffness promotes metastatic cancer cell interaction with the endothelium
YesTumor progression alters the composition and physical properties of the extracellular matrix. Particularly, increased matrix stiffness has profound effects on tumor growth and metastasis. While endothelial cells are key players in cancer progression, the influence of tumor stiffness on the endothelium and the impact on metastasis is unknown. Through quantitative mass spectrometry, we find that the matricellular protein CCN1/CYR61 is highly regulated by stiffness in endothelial cells. We show that stiffness-induced CCN1 activates ÎČ-catenin nuclear translocation and signaling and that this contributes to upregulate N-cadherin levels on the surface of the endothelium, in vitro This facilitates N-cadherin-dependent cancer cell-endothelium interaction. Using intravital imaging, we show that knockout of Ccn1 in endothelial cells inhibits melanoma cancer cell binding to the blood vessels, a critical step in cancer cell transit through the vasculature to metastasize. Targeting stiffness-induced changes in the vasculature, such as CCN1, is therefore a potential yet unappreciated mechanism to impair metastasis.Cancer Research UK (CRUK Beatson Institute C596/A17196, CRUK Glasgow Centre C596/A18076 and S.Z. C596/A12935
ï»żNotulae to the Italian flora of algae, bryophytes, fungi and lichens: 14
In this contribution, new data concerning bryophytes, fungi and lichens of the Italian flora are presented. It includes new records and confirmations for the algal genus Chara, for the bryophyte genera Bryum, Grimmia, Cephaloziella, Hypnum, Nogopterium, Physcomitrium, Polytrichastrum, Rhynchostegiella, Saelania, and Schistostega, the fungal genera Cortinarius, Lentinellus, Omphalina, and Xerophorus, and the lichen genera Acarospora, Agonimia, Candelariella, Cladonia, Graphis, Gyalolechia, Hypogymnia, Lichinella, Megalaria, Nephroma, Ochrolechia, Opegrapha, Peltigera, Placidium, Ramalina, Rhizoplaca, Ropalospora, Strangospora, Toniniopsis, Usnea, and Zahlbrucknerell
The JWST Galactic Center Survey -- A White Paper
The inner hundred parsecs of the Milky Way hosts the nearest supermassive
black hole, largest reservoir of dense gas, greatest stellar density, hundreds
of massive main and post main sequence stars, and the highest volume density of
supernovae in the Galaxy. As the nearest environment in which it is possible to
simultaneously observe many of the extreme processes shaping the Universe, it
is one of the most well-studied regions in astrophysics. Due to its proximity,
we can study the center of our Galaxy on scales down to a few hundred AU, a
hundred times better than in similar Local Group galaxies and thousands of
times better than in the nearest active galaxies. The Galactic Center (GC) is
therefore of outstanding astrophysical interest. However, in spite of intense
observational work over the past decades, there are still fundamental things
unknown about the GC. JWST has the unique capability to provide us with the
necessary, game-changing data. In this White Paper, we advocate for a JWST
NIRCam survey that aims at solving central questions, that we have identified
as a community: i) the 3D structure and kinematics of gas and stars; ii)
ancient star formation and its relation with the overall history of the Milky
Way, as well as recent star formation and its implications for the overall
energetics of our galaxy's nucleus; and iii) the (non-)universality of star
formation and the stellar initial mass function. We advocate for a large-area,
multi-epoch, multi-wavelength NIRCam survey of the inner 100\,pc of the Galaxy
in the form of a Treasury GO JWST Large Program that is open to the community.
We describe how this survey will derive the physical and kinematic properties
of ~10,000,000 stars, how this will solve the key unknowns and provide a
valuable resource for the community with long-lasting legacy value.Comment: This White Paper will be updated when required (e.g. new authors
joining, editing of content). Most recent update: 24 Oct 202
ConexiĂłn inteligente para la gestiĂłn turĂstica desde el aula al destino (CIGTAD)
Fac. de Comercio y TurismoFac. de Trabajo SocialFALSEsubmitte
Influenza Vaccination for the Prevention of Cardiovascular Disease in the Americas: Consensus document of the Inter-American Society of Cardiology and the Word Heart Federation
Background
Cardiovascular mortality is decreasing but remains the leading cause of death world-wide. Respiratory infections such as influenza significantly contribute to morbidity and mortality in patients with cardiovascular disease. Despite of proven benefits, influenza vaccination is not fully implemented, especially in Latin America.
Objective
The aim was to develop a regional consensus with recommendations regarding influenza vaccination and cardiovascular disease.
Methods
A multidisciplinary team composed by experts in the management and prevention of cardiovascular disease from the Americas, convened by the Inter-American Society of Cardiology (IASC) and the World Heart Federation (WHF), participated in the process and the formulation of statements. The modified RAND/UCLA methodology was used. This document was supported by a grant from the WHF.
Results
An extensive literature search was divided into seven questions, and a total of 23 conclusions and 29 recommendations were achieved. There was no disagreement among experts in the conclusions or recommendations.
Conclusions
There is a strong correlation between influenza and cardiovascular events. Influenza vaccination is not only safe and a proven strategy to reduce cardiovascular events, but it is also cost saving. We found several barriers for its global implementation and potential strategies to overcome them
Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic
This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic