Flower morphology, gender functionality, and pollinator dynamics in Solanum carolinense: implications for the evolution of andromonoecy

Morphological differences in flowers have important evolutionary consequences; they influence the plant's relationship with pollinators and are strongly correlated with sexual function in some breeding systems. Here, I explore the functional relationship between flower morphology and pollination dynamics (e.g. pollen receipt / export) in Solanum carolinense (Solanaceae) and evaluate whether this relationship varies with pollinator taxa. I also investigate if flower morphology determines fruit setting ability of flowers under different pollination regimes. Solanum carolinense has been characterized as having an andromonoecious sexual system where individual plants bear both hermaphroditic and male flowers. This species presents an ideal system to study the relationship between floral morphology, functionality and pollinators because flowers in natural populations vary in their style length and grow in diverse array of environments that vary in their pollinator fauna composition. I conducted a series of greenhouse experiments, pollinator observations and natural population surveys to test these relationships. My results demonstrate that long styled flowers serve as pollen recipients and short styled flowers as pollen donors. However, only bumblebees when (Bombus impatiens) are the pollinators I observe a positive relationship between style length and pollen deposition and a negative relationship with pollen removal. These findings support the female/male interference hypothesis and suggest that when plants are visited by species of species of Bombus, the differences in fitness could favor the evolution of andromonoecy. In contrast, when plants arevisited either by Augochloropsis metallica or Lassioglossum spp. there is no selection for the dimorphism (or any particular style length). I also found that flower morphology, in particular style length, determines the fruit setting ability of the flowers in S. carolinense under different pollination regimes. However, in some flowers sexual functionality varies and does not accord with traditional classification of the flowers. The variation observed for style length, functionality and production of staminate flowers among individuals in natural populations of S. carolinense could be due to variation in abundance and visitation rate of pollinator taxa. Future studies should not neglect taxa-specific plant-pollinator interactions because the evolution of plant breeding systems can be determined by taxa specific interactions

Sensibilidad a los antibióticos en bacterias Gram negativas de bulbos de cebolla en Tierra Blanca de Cartago

El objetivo de este estudio fue identificar géneros bacterianos en bulbos de cebolla sanos y bulbos que presentaban síntomas, de la zona de Tierra Blanca de Cartago y determinar la susceptibilidad a los antibióticos gentamicina y tetraciclina, dos de los antibióticos más usados en la agricultura en Costa Rica. El cultivo de la cebolla se practica en diferentes regiones del país, principalmente en la zona de Cartago. Este cultivo puede ser atacado por una gran variedad de plagas y enfermedades que pueden disminuir el crecimiento y la producción, causar daños y desfigurar los bulbos impidiendo su comercialización. Las bacterias que atacan los cultivos causan grandes pérdidas económicas, por eso se han buscado diversos métodos para controlarlas, entre ellos, el uso de antibióticos como tetraciclina y gentamicina. La selección y diseminación en la naturaleza de cepas resistentes a los antibióticos es una práctica que se debe controlar, con el fin de mantener un balance ecológico que favorezca el predominio de bacterias susceptibles y asegurar el tratamiento efectivo de las enfermedades infecciosas humanas

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe

Toxin B Variants from Clostridium difficile Strains VPI 10463 and NAP1/027 Share Similar Substrate Profile and Cellular Intoxication Kinetics but Use Different Host Cell Entry Factors

Clostridium difficile induces antibiotic-associated diarrhea due to the release of toxin A (TcdA) and toxin B (TcdB), the latter being its main virulence factor. The epidemic strain NAP1/027 has an increased virulence attributed to different factors. We compared cellular intoxication by TcdBNAP1 with that by the reference strain VPI 10463 (TcdBVPI). In a mouse ligated intestinal loop model, TcdBNAP1 induced higher neutrophil recruitment, cytokine release, and epithelial damage than TcdBVPI. Both toxins modified the same panel of small GTPases and exhibited similar in vitro autoprocessing kinetics. On the basis of sequence variations in the frizzled-binding domain (FBD), we reasoned that TcdBVPI and TcdBNAP1 might have different receptor specificities. To test this possibility, we used a TcdB from a NAP1 variant strain (TcdBNAP1v) unable to glucosylate RhoA but with the same receptor-binding domains as TcdBNAP1. Cells were preincubated with TcdBNAP1v to block cellular receptors, prior to intoxication with either TcdBVPI or TcdBNAP1. Preincubation with TcdBNAP1v blocked RhoA glucosylation by TcdBNAP1 but not by TcdBVPI, indicating that the toxins use different host factors for cell entry. This crucial difference might explain the increased biological activity of TcdBNAP1 in the intestine, representing a contributing factor for the increased virulence of the NAP1/027 strain.Universidad de Costa Rica/[803-B8-117]/UCR/Costa RicaUniversidad de Costa Rica/[803-B7-183]/UCR/Costa RicaUniversidad de Costa Rica/[803-B7-158]/UCR/Costa RicaUniversidad de Costa Rica/[803-B6-657]/UCR/Costa RicaUCR::Vicerrectoría de Docencia::Salud::Facultad de MicrobiologíaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET)UCR::Vicerrectoría de Docencia::Salud::Facultad de FarmaciaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Laboratorio de Ensayos Biológicos (LEBI)UCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de Medicin

REVISTA SERENGUETI 1(2)

Se destaca, de manera general, que la revista Serengueti se compone como una herramienta capaz de incentivar la participación estudiantil, en el cual principalmente se tiene como fin evidenciar y reconocer los esfuerzos realizados por parte de los estudiantes activos de la carrera de Estadística mediante artículos que son calificados y recomendados por los profesores del curso respectivo. Se promueve la revista como modelo para desarrollar en un futuro propuestas de enseñanza que permitan brindar diferentes formas y técnicas de aprendizaje. El volumen 2 se toma como eje temático el análisis multivariado, cuya finalidad es mediante un conjunto de métodos estadísticos y matemáticos, describir e interpretar los datos que provienen de la observación de variables estadísticas y que han sido analizadas simultáneamente (Cuadras, 2007, p.9)2. A partir de ello, se proponen algunas técnicas multivariantes como lo son el análisis factorial, técnicas de agrupamiento y minería de datos para predicción. Además, se realiza un apartado de simulaciones en el que se asocia al análisis factorial por la cercanía de los temas propuestos, pero la técnica de análisis se elabora desde un enfoque distinto.UCR::Vicerrectoría de Docencia::Ciencias Sociales::Facultad de Ciencias Económicas::Escuela de Estadístic

Prospective cohort study of incidence and risk factors for catheter-associated urinary tract infections in 145 intensive care units of 9 Latin American countries: INICC findings

Purpose: Identify urinary catheter (UC)-associated urinary tract infections (CAUTI) incidence and risk factors (RF) in Latin American Countries. Methods: From 01/01/2014 to 02/10/2022, we conducted a prospective cohort study in 145 ICUs of 67 hospitals in 35 cities in nine Latin American countries: Argentina, Brazil, Colombia, Costa Rica, Dominican Republic, Ecuador, Mexico, Panama, and Peru. To estimate CAUTI incidence, we used the number of UC-days as the denominator, and the number of CAUTIs as numerator. To estimate CAUTI RFs, we analyzed the following 10 variables using multiple logistic regression: gender, age, length of stay (LOS) before CAUTI acquisition, UC-days before CAUTI acquisition, UC-device utilization (DU) ratio, UC-type, hospitalizationtype, ICU type, facility ownership, and time period. Results: 31,631 patients, hospitalized for 214,669 patient-days, acquired 305 CAUTIs. The pooled CAUTI rate per 1000 UC-days was 2.58, for those using suprapubic catheters, it was 2.99, and for those with indwelling catheters, it was 2.21. The following variables were independently associated with CAUTI: age, rising risk 1% yearly (aOR = 1.01; 95% CI 1.01–1.02; p < 0.0001 female gender (aOR = 1.28; 95% CI 1.01–1.61; p = 0.04), LOS before CAUTI acquisition, rising risk 7% daily (aOR = 1.07; 95% CI 1.06–1.08; p < 0.0001, UC/DU ratio (aOR = 1.14; 95% CI 1.08–1.21; p < 0.0001, public facilities (aOR = 2.89; 95% CI 1.75–4.49; p < 0.0001. The periods 2014–2016 and 2017–2019 had significantly higher risks than the period 2020–2022. Suprapubic catheters showed similar risks as indwelling catheters. Conclusion: The following CAUTI RFs are unlikely to change: age, gender, hospitalization type, and facility ownership. Based on these findings, it is suggested to focus on reducing LOS, UC/DU ratio, and implementing evidence-based CAUTI prevention recommendations.Revisión por pare

Multinational prospective cohort study of incidence and risk factors for central line-associated bloodstream infections in ICUs of 8 Latin American countries

Background: Our objective was to identify central line (CL)-associated bloodstream infections (CLABSI) rates and risk factors in Latin-America. Methods: From January 1, 2014 to February 10, 2022, we conducted a multinational multicenter prospective cohort study in 58 ICUs of 34 hospitals in 21 cities in 8 Latin American countries (Argentina, Brazil, Colombia, Costa Rica, Dominican Republic, Ecuador, Mexico, Panama). We applied multiple-logistic regression. Outcomes are shown as adjusted-odds ratios (aOR). Results: About 29,385 patients were hospitalized during 92,956 days, acquired 400 CLABSIs, and pooled CLABSI rate was 4.30 CLABSIs per 1,000 CL-days. We analyzed following 10 variables: Gender, age, length of stay (LOS) before CLABSI acquisition, CL-days before CLABSI acquisition, CL-device utilization (DU) ratio, CL-type, tracheostomy use, hospitalization type, intensive care unit (ICU) type, and facility ownership, Following variables were independently associated with CLABSI: LOS before CLABSI acquisition, rising risk 3% daily (aOR=1.03;95%CI=1.02-1.04; P < .0001); number of CL-days before CLABSI acquisition, rising risk 4% per CL-day (aOR=1.04;95%CI=1.03-1.05; P < .0001); publicly-owned facility (aOR=2.33;95%CI=1.79-3.02; P < .0001). ICU with highest risk was medical-surgical (aOR=2.61;95%CI=1.41-4.81; P < .0001). CL with the highest risk were femoral (aOR=2.71;95%CI=1.61-4.55; P < .0001), and internal-jugular (aOR=2.62;95%CI=1.82-3.79; P < .0001). PICC (aOR=1.25;95%CI=0.63-2.51; P = .52) was not associated with CLABSI risk. Conclusions: Based on these findings it is suggested to focus on reducing LOS, CL-days, using PICC instead of femoral or internal-jugular; and implementing evidence-based CLABSI prevention recommendations.Revisión por pare