Los niveles glauconíticos de la Formación Salamanca, Chubut : su efectividad agronómica como fuente alternativa de fertilizante potásico

391-398The Maastrichtian-Early Palaeocene Salamanca Formation and equivalent marine sequences show several glaucony levels, which could be used as a source of potassium and could partially replace current fertilizer requirements met from import. First agronomic assays are shown comparing the efficiency of greensands (GL) with a traditional potassium fertilizer (KCl). Prospection and sampling took place in the heads of Rio Chico to east of Lago Colhué Huapi, Chubut, where glauconitic levels thickness reach to 20m. This research was separated in phases: phase 1, prospection, sampling, and sedimentological and chemical routine analyses, phase 2a, concentration and ore treatment assays, and phase 2b, agronomic assays. This last phase, was done in culture chamber, with 125 um and 250 um fractions (2,85 and 2,82 percent K 2O respectively) and KCl. Varying the dose, seven treatments were completed. In successive harvests (four in total) was observed that GL1 and GL2 (125), did not present a significantly differential behavior with the control. Both treatments of GL 250 um showed major accumulated biomass, overcoming the control in 44 and 60 percent respectively. As conclusion, better results were obtained by 250 um overcoming even to the KCl fertilization. Probably the major participation of K feldspars in the 125 um and fast leaching of K in this fraction during successive irrigations of soil would originate the minor observed yield. The great areal extension of the Salamanca Formation and the continuity of the glauconitic levels encourage continuing the evaluation as fertilizer or amendment

Los niveles glauconíticos de la Formación Salamanca, Chubut : su efectividad agronómica como fuente alternativa de fertilizante potásico

391-398The Maastrichtian-Early Palaeocene Salamanca Formation and equivalent marine sequences show several glaucony levels, which could be used as a source of potassium and could partially replace current fertilizer requirements met from import. First agronomic assays are shown comparing the efficiency of greensands (GL) with a traditional potassium fertilizer (KCl). Prospection and sampling took place in the heads of Rio Chico to east of Lago Colhué Huapi, Chubut, where glauconitic levels thickness reach to 20m. This research was separated in phases: phase 1, prospection, sampling, and sedimentological and chemical routine analyses, phase 2a, concentration and ore treatment assays, and phase 2b, agronomic assays. This last phase, was done in culture chamber, with 125 um and 250 um fractions (2,85 and 2,82 percent K 2O respectively) and KCl. Varying the dose, seven treatments were completed. In successive harvests (four in total) was observed that GL1 and GL2 (125), did not present a significantly differential behavior with the control. Both treatments of GL 250 um showed major accumulated biomass, overcoming the control in 44 and 60 percent respectively. As conclusion, better results were obtained by 250 um overcoming even to the KCl fertilization. Probably the major participation of K feldspars in the 125 um and fast leaching of K in this fraction during successive irrigations of soil would originate the minor observed yield. The great areal extension of the Salamanca Formation and the continuity of the glauconitic levels encourage continuing the evaluation as fertilizer or amendment

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Latest Cretaceous climatic and environmental change in the South Atlantic region

Latest Maastrichtian climate change caused by Deccan volcanism has been invoked as a cause of mass extinction at the Cretaceous-Paleogene (K-Pg) boundary (~66.0 Ma). Yet late Maastrichtian climate and ecological changes are poorly documented, in particular on the Southern Hemisphere. Here we present upper Maastrichtian-lower Danian climate and biotic records from the Bajada del Jagüel (BJ) shelf site (Neuquén Basin, Argentina), employing the TEX86 paleothermometer, marine palynology (dinoflagellate cysts), and micropaleontology (foraminifera). These records are correlated to the astronomically tuned Ocean Drilling Program Site 1262 (Walvis Ridge). Collectively, we use these records to assess climatic and ecological effects of Deccan volcanism in the Southern Atlantic region. Both the TEX86-based sea surface temperature (SST) record at BJ and the bulk carbonate δ18O-based SST record of Site 1262 show a latest Maastrichtian warming of ~2.5-4°C, at 450 to 150 kyr before the K-Pg boundary, coinciding with the a large Deccan outpouring phase. Benthic foraminiferal and dinocyst assemblage changes indicate that this warming resulted in enhanced runoff and stratification of the water column, likely resulting from more humid climate conditions in the Neuquén Basin. These climate conditions could have been caused by an expanding and strengthening thermal low over the South American continent. Biotic changes in response to late Maastrichtian environmental changes are rather limited, when compared to the major turnovers observed at many K-Pg boundary sites worldwide. This suggests that environmental perturbations during the latest Maastrichtian warming event were less severe than those following the K-Pg boundary impact