Biodiversidad de macrocrustáceos del río Fuerte, Sinaloa, México

The Fuerte river forms large ecosystems in its channel that serve as the habitats for freshwater macrocrustaceans with ecological and economical importance in the Northern area of the state of Sinaloa, Mexico. The objective of this investigation is to generate information about the biodiversity and the spatial patterns of the crustacean community due to the absence of published data of this fauna. Therefore, five sampling stations were established (El Fuerte, San Blas, San Miguel, San José and Las Grullas) along the river channel at different altitudes (m a.s.l.) and distances, beginning at El Fuerte (EI) municipality until its mouth at Las Grullas (EV) in the Ahome municipality. The specific richness was 12 (S=12). Palaemonids and cambarids were the best represented taxa. The diversity (Shannon-Wiener index) was higher (H’=0.92) than the recorded in other Mexican rivers. The Bray Curtis ordination (nMDS) analysis showed that the community was formed by three well defined groups. Macrobrachium tenellum and Potimirin glabra were the most abundant species. Las Grullas sector showed the minor number of individuals, with the presence of species such as Litopenaeus vannamei and Callinectes arcuatus. Furthermore, an exotic species (Procambarus clarkii) was found as well as a species (P. glabra) previously not reported for the region.El río Fuerte, a través de su cauce forma grandes ecosistemas que sirven de hábitat para especies de macrocrustáceos de agua dulce que son de importancia ecológica y económica en la zona norte del estado de Sinaloa, México. El objetivo de esta investigación es generar información acerca de la diversidad de macrocrustáceos y su distribución espacial en el río Fuerte, ya que no existe información publicada al respecto. Se establecieron cinco estaciones de muestreo (El Fuerte, San Blas, San Miguel, San José y Las Grullas) a lo largo de su cauce en función de la altitud (m s.n.m) y distancia entre las mismas, iniciando en el municipio de El Fuerte (EI) hasta su desembocadura en la población de Las Grullas (EV) del municipio de Ahome. La riqueza específica total fue de 12 taxa. Palémonidos y cambáridos fueron los taxa mejor representados. La diversidad (índice de Shannon-Wiener) fue mayor (H ́=0,92) respecto a otros ríos de México. El análisis de ordenación nMDS de Bray Curtis indicó que la comunidad se puede agrupar en tres grupos bien definidos. Macrobrachium tenellum y Potimirim glabra fueron las especies más abundantes. El sector Las Grullas tuvo el menor número de individuos, con presencia de especies como Litopenaeus vannamei y Callinectes arcuatus. Además, se registró la presencia de una especie exótica (Procambarus clarkii) y una no citada previamente para la zona (P. glabra)

Biodiversity of macrocrustaceans of river Fuerte, Sinaloa, Mexico

El río Fuerte, a través de su cauce forma grandes ecosistemas que sirven de hábitat para especies de macrocrustáceos de agua dulce que son de importancia ecológica y económica en la zona norte del estado de Sinaloa, México. El objetivo de esta investigación es generar información acerca de la diversidad de macrocrustáceos y su distribución espacial en el río Fuerte, ya que no existe información publicada al respecto. Se establecieron cinco estaciones de muestreo (El Fuerte, San Blas, San Miguel, San José y Las Grullas) a lo largo de su cauce en función de la altitud (m s.n.m) y distancia entre las mismas, iniciando en el municipio de El Fuerte (EI) hasta su desembocadura en la población de Las Grullas (EV) del municipio de Ahome. La riqueza específica total fue de 12 taxa. Palémonidos y cambáridos fueron los taxa mejor representados. La diversidad (índice de Shannon-Wiener) fue mayor (H´=0,92) respecto a otros ríos de México. El análisis de ordenación nMDS de Bray Curtis indicó que la comunidad se puede agrupar en tres grupos bien definidos. Macrobrachium tenellum y Potimirim glabra fueron las especies más abundantes. El sector Las Grullas tuvo el menor número de individuos, con presencia de especies como Litopenaeus vannamei y Callinectes arcuatus. Además, se registró la presencia de una especie exótica (Procambarus clarkii) y una no citada previamente para la zona (P. glabra).The Fuerte river forms large ecosystems in its channel that serve as the habitats for freshwater macrocrustaceans with ecological and economical importance in the Northern area of the state of Sinaloa, Mexico. The objective of this investigation is to generate information about the biodiversity and the spatial patterns of the crustacean community due to the absence of published data of this fauna. Therefore, five sampling stations were established (El Fuerte, San Blas, San Miguel, San José and Las Grullas) along the river channel at different altitudes (m a.s.l.) and distances, beginning at El Fuerte (EI) municipality until its mouth at Las Grullas (EV) in the Ahome municipality. The specific richness was 12 (S=12). Palaemonids and cambarids were the best represented taxa. The diversity (Shannon-Wiener index) was higher (H’=0.92) than the recorded in other Mexican rivers. The Bray Curtis ordination (nMDS) analysis showed that the community was formed by three well defined groups. Macrobrachium tenellum and Potimirin glabra were the most abundant species. Las Grullas sector showed the minor number of individuals, with the presence of species such as Litopenaeus vannamei and Callinectes arcuatus. Furthermore, an exotic species (Procambarus clarkii) was found as well as a species (P. glabra) previously not reported for the region.Instituto de Limnología "Dr. Raúl A. Ringuelet

Biodiversidad de macrocrustáceos del río Fuerte, Sinaloa, México

El río Fuerte, a través de su cauce forma grandes ecosistemas que sirven de hábitat para especies de macrocrustáceos de agua dulce que son de importancia ecológica y económica en la zona norte del estado de Sinaloa, México. El objetivo de esta investigación es generar información acerca de la diversidad de macrocrustáceos y su distribución espacial en el río Fuerte, ya que no existe información publicada al respecto. Se establecieron cinco estaciones de muestreo (El Fuerte, San Blas, San Miguel, San José y Las Grullas) a lo largo de su cauce en función de la altitud (m s.n.m) y distancia entre las mismas, iniciando en el municipio de El Fuerte (EI) hasta su desembocadura en la población de Las Grullas (EV) del municipio de Ahome. La riqueza específica total fue de 12 taxa. Palémonidos y cambáridos fueron los taxa mejor representados. La diversidad (índice de Shannon-Wiener) fue mayor (H ́=0,92) respecto a otros ríos de México. El análisis de ordenación nMDS de Bray Curtis indicó que la comunidad se puede agrupar en tres grupos bien definidos. Macrobrachium tenellum y Potimirim glabra fueron las especies más abundantes. El sector Las Grullas tuvo el menor número de individuos, con presencia de especies como Litopenaeus vannamei y Callinectes arcuatus. Además, se registró la presencia de una especie exótica (Procambarus clarkii) y una no citada previamente para la zona (P. glabra)

Electrical Conduction Mechanisms in Ethyl Cellulose Films under DC and AC Electric Fields

This work reports the dielectric behavior of the biopolymer ethyl cellulose (EC) observed from transient currents experiments under the action of a direct current (DC) electric field (~107 V/m) under vacuum conditions. The viscoelastic response of the EC was evaluated using dynamic mechanical analysis (DMA), observing a mechanical relaxation related to glass transition of around ~402 K. Furthermore, we propose a mathematical framework that describes the transient current in EC using a fractional differential equation, whose solution involves the Mittag–Leffler function. The fractional order, between 0 and 1, is related to the energy dissipation rate and the molecular mobility of the polymer. Subsequently, the conduction mechanisms are considered, on the one hand, the phenomena that occur through the polymer–electrode interface and, on the other hand, those which manifest themselves in the bulk material. Finally, alternating current (AC) conductivity measurements above the glass transition temperature (~402 K) and in a frequency domain from 20 Hz to 2 MHz were carried out, observing electrical conduction described by the segmental movements of the polymeric chains. Its electrical properties also position EC as a potential candidate for electrical, electronics, and mechatronics applications

Evolution over Time of Ventilatory Management and Outcome of Patients with Neurologic Disease∗

OBJECTIVES: To describe the changes in ventilator management over time in patients with neurologic disease at ICU admission and to estimate factors associated with 28-day hospital mortality. DESIGN: Secondary analysis of three prospective, observational, multicenter studies. SETTING: Cohort studies conducted in 2004, 2010, and 2016. PATIENTS: Adult patients who received mechanical ventilation for more than 12 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among the 20,929 patients enrolled, we included 4,152 (20%) mechanically ventilated patients due to different neurologic diseases. Hemorrhagic stroke and brain trauma were the most common pathologies associated with the need for mechanical ventilation. Although volume-cycled ventilation remained the preferred ventilation mode, there was a significant (p < 0.001) increment in the use of pressure support ventilation. The proportion of patients receiving a protective lung ventilation strategy was increased over time: 47% in 2004, 63% in 2010, and 65% in 2016 (p < 0.001), as well as the duration of protective ventilation strategies: 406 days per 1,000 mechanical ventilation days in 2004, 523 days per 1,000 mechanical ventilation days in 2010, and 585 days per 1,000 mechanical ventilation days in 2016 (p < 0.001). There were no differences in the length of stay in the ICU, mortality in the ICU, and mortality in hospital from 2004 to 2016. Independent risk factors for 28-day mortality were age greater than 75 years, Simplified Acute Physiology Score II greater than 50, the occurrence of organ dysfunction within first 48 hours after brain injury, and specific neurologic diseases such as hemorrhagic stroke, ischemic stroke, and brain trauma. CONCLUSIONS: More lung-protective ventilatory strategies have been implemented over years in neurologic patients with no effect on pulmonary complications or on survival. We found several prognostic factors on mortality such as advanced age, the severity of the disease, organ dysfunctions, and the etiology of neurologic disease

Effects of pre-operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study an international prospective cohort study

We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care. We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care