The Paleozoic and Mesozoic vertebrate record of Venezuela: An overview, summary of previous discoveries and report of a mosasaur from the La Luna Formation (Cretaceous)

Most reports of Paleozoic and Mesozoic vertebrates from Venezuela are anecdotical, with few detailed descriptions of mostly ‘fish' groups. Synapsids (e.g., mammals) are totally unknown, and dinosaurs are only reported from the La Quinta Formation. At least 14 formally recognized geological formations contain fossil vertebrates, most from the Central and Western parts of the country. In the Devonian there is a significant contrast between the vertebrates of Venezuela and Colombia and those of more southern parts of South America. Marine reptiles are present in a few localities in western Venezuela, and are very fragmentary, with one exception. A mosasaur from the Cretaceous La Luna Formation, reported here for the first time, is the most complete vertebrate (tetrapod) from the Cretaceous of Venezuela, and includes a partial skull and a few postcranial remain

Efectos de la administración crónica de alcohol sobre la conducta motora y su relación con el sistema colinérgico muscarinico en ratas Sprague Dawley bajo estrés discontinuos

El alcohol y el estrés son problemas de salud pública que afectan el Receptor Colinérgico Muscarínico (RCM). En el presente trabajo se estudia el efecto de ambos fenómenos sobre la funcionalidad y densidad del RCM. Métodos: 43 ratas Sprague Dawley se dividieron en 4 grupos: Control (n=12), Estrés (n=11), Alcohol (n=10) y Alcohol-Estrés (n=10). A los grupos alcohol se le administró diariamente etanol al 10 % ad libitum y los grupos Estrés se sometieron a nado forzado a 5°C por 5 min tres veces/semana. Resultados:las ratas tratadas con alcohol presentaron adicción e hipermotilidad, siendo el efecto mayor en el grupo alcohol-estrés. Escopolamina incremento la motilidad en todos los grupos. No hubo diferencias significativas entre los grupos en el desempeño en el Rotarod. La densidad de los RCM estuvo disminuida significativamente en Hipocampo en el grupo alcohol. Conclusión: el alcohol induce trastornos del RCM relacionados a hipermotilidad.Alcohol consumption and stress are health problems, which affects the Cholinergic Muscarinic Receptor (CMR) system. Here we studied the effect of both phenomena on CMR functionality and densities. Methods: 43 Sprague Dawley rats were divided in 4 groups: Control (n=11), Stress (n=10), Alcohol (n=10) and Alcohol-Stress (n=9). Alcohol groups received 10% ethanol ad libitum in substitution of water every day, stress groups were submitted 3 days at week to 5 min force swimming at 5°C. Results: rats that had alcohol displayedaddiction and hypermotility, the effect was higher at alcohol-stress group. Scopolamine significantly increased motility in all groups. No differences were observed at Rotarod performance. CMR density was decreased in hippocampus of rats belonging to alcohol group. Conclusion: alcohol induces motor disturbances related to CMR system

An Algorithm for Emulsion Stability Simulations: Account of Flocculation, Coalescence, Surfactant Adsorption and the Process of Ostwald Ripening

The first algorithm for Emulsion Stability Simulations (ESS) was presented at the V Conferencia Iberoamericana sobre Equilibrio de Fases y Diseño de Procesos [Luis, J.; García-Sucre, M.; Urbina-Villalba, G. Brownian Dynamics Simulation of Emulsion Stability In: Equifase 99. Libro de Actas, 1st Ed., Tojo J., Arce, A., Eds.; Solucion’s: Vigo, Spain, 1999; Volume 2, pp. 364–369]. The former version of the program consisted on a minor modification of the Brownian Dynamics algorithm to account for the coalescence of drops. The present version of the program contains elaborate routines for time-dependent surfactant adsorption, average diffusion constants, and Ostwald ripening

Comparing lung mechanics of patients with COVID related respiratory distress syndrome versus non-COVID acute respiratory distress syndrome: a retrospective observational study

Background Most patients admitted to the intensive care unit with coronavirus disease (COVID-19) develop severe respiratory failure. Understanding lung mechanics helps to guide protective mechanical ventilation, improve oxygenation, and reduce the ventilator induce lung injury. This study aims to describe lung mechanics characteristics of patients with COVID -19 related acute respiratory distress syndrome (CARDS) and to compare them with non-COVID-19 associated ARDS. Methods We performed a retrospective observational study of lung mechanics: plateau pressure (Pplat), Driving pressure (DP), Mechanical power (MPw), Elastic (dynamic) power (EdPw), Total ventilatory power (TPw), and oxygenation parameters (ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2), the ratio of arterial oxygen partial pressure to fractional inspired oxygen multiplied by PEEP [PaO2/(FiO2 x PEEP)], arterial and venous carbon dioxide partial pressure (PaCO2, PvCO2), and Ventilation dead space (VD) were measured and compared between the two groups after initiation of mechanical ventilation. Results 30 CARDS and 10 ARDS patients fulfilled the study requirements. We observed a significant higher MPw in the CARDS group (29.17 ± 8.29 J/min vs 15.78 ± 4.45 J/min, P 0.007), similarly observed with EdPw (256.7 ± 84.06 mJ/min vs 138.1 ± 39.15 mJ/min, P 0.01) and TPw (289.1 ± 84.51 mJ/min vs 161.5 ± 45.51, P 0.007). Inside the CARDS group, we found 2 subgroups, a low shunt subgroup and a higher shunt (Qs/Qt (%): 6.61 ± 2.46 for vs 40.3 ± 20.6, P 0.0009), however, between these two subgroups we didn’t find statistical differences on lung mechanic parameters but only in oxygenation parameters (PaO2/FiO2 and PaO2/FiO2*PEEP). When comparing these two subgroups with ARDS patients, we found more similarity between the low shunt CARDS and the ARDS patients on MP (R2 0.99, P 0.001), EdPw (R2 0.89, P 0.05) and TPw (R2 0.99, P 0.0009). Conclusions Our study suggests important differences between CARDS and ARDS regarding mechanical parameters that could lead to more complicated management of CARDS patients and a higher prevalence of VILI. However due to the study limitations, a bigger study is necessary to corroborate our findings

Efectos de la administración crónica de alcohol sobre la conducta motora y su relación con el sistema colinérgico muscarinico en ratas Sprague Dawley bajo estrés discontinuos

El alcohol y el estrés son problemas de salud pública que afectan el Receptor Colinérgico Muscarínico (RCM). En el presente trabajo se estudia el efecto de ambos fenómenos sobre la funcionalidad y densidad del RCM. Métodos: 43 ratas Sprague Dawley se dividieron en 4 grupos: Control (n=12), Estrés (n=11), Alcohol (n=10) y Alcohol-Estrés (n=10). A los grupos alcohol se le administró diariamente etanol al 10 % ad libitum y los grupos Estrés se sometieron a nado forzado a 5°C por 5 min tres veces/semana. Resultados:las ratas tratadas con alcohol presentaron adicción e hipermotilidad, siendo el efecto mayor en el grupo alcohol-estrés. Escopolamina incremento la motilidad en todos los grupos. No hubo diferencias significativas entre los grupos en el desempeño en el Rotarod. La densidad de los RCM estuvo disminuida significativamente en Hipocampo en el grupo alcohol. Conclusión: el alcohol induce trastornos del RCM relacionados a hipermotilidad.Alcohol consumption and stress are health problems, which affects the Cholinergic Muscarinic Receptor (CMR) system. Here we studied the effect of both phenomena on CMR functionality and densities. Methods: 43 Sprague Dawley rats were divided in 4 groups: Control (n=11), Stress (n=10), Alcohol (n=10) and Alcohol-Stress (n=9). Alcohol groups received 10% ethanol ad libitum in substitution of water every day, stress groups were submitted 3 days at week to 5 min force swimming at 5°C. Results: rats that had alcohol displayedaddiction and hypermotility, the effect was higher at alcohol-stress group. Scopolamine significantly increased motility in all groups. No differences were observed at Rotarod performance. CMR density was decreased in hippocampus of rats belonging to alcohol group. Conclusion: alcohol induces motor disturbances related to CMR system

New discoveries of vertebrates from a near-shore marine fauna from the Early Miocene of northwestern Venezuela

New discoveries from a recently described nearshore marine fauna from northwestern Venezuela of presumed early Miocene age are reported. The fossils consist of a cranial portion of a crocodile assigned to the Tbmistominae, confirming the presence of this group in South America, and the scapula of a cetacean with affinities to the Platanistoidea. The stratigraphic section of the fossil locality ‘Cerro La Cruz’ consists of ca. 87 m of clayey marls interbedded with thin hardground units, with the upper strata being gypsiferous. The fossils were found in sandstones stratigraphically above this sequence.Museo de La Plat