262 research outputs found
Revealing the last 13,500 years of environmental history from the multiproxy record of a mountain lake (Lago Enol, northern Iberian Peninsula)
This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s10933-009-9387-7.We present the Holocene sequence from Lago Enol (43°16′N, 4°59′W, 1,070 m a.s.l.), Cantabrian Mountains, northern Spain. A multiproxy analysis provided comprehensive information about regional humidity and temperature changes. The analysis included sedimentological descriptions, physical properties, organic carbon and carbonate content, mineralogy and geochemical composition together with biological proxies including diatom and ostracod assemblages. A detailed pollen study enabled reconstruction of variations in vegetation cover, which were interpreted in the context of climate changes and human impact. Four distinct stages were recognized for the last 13,500 years: (1) a cold and dry episode that includes the Younger Dryas event (13,500–11,600 cal. year BP); (2) a humid and warmer period characterizing the onset of the Holocene (11,600–8,700 cal. year BP); (3) a tendency toward a drier climate during the middle Holocene (8,700–4,650 cal. year BP); and (4) a return to humid conditions following landscape modification by human activity (pastoral activities, deforestation) in the late Holocene (4,650–2,200 cal. year BP). Superimposed on relatively stable landscape conditions (e.g. maintenance of well established forests), the typical environmental variability of the southern European region is observed at this site.The Spanish Inter-Ministry Commission of Science and
Technology (CICYT), the
Spanish National Parks agency, the European Commission, the
Spanish Ministry of Science, and the European
Social Fund
Revealing the last 13,500 years of environmental history from the multiproxy record of a mountain lake (Lago Enol, northern Iberian Peninsula)
This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s10933-009-9387-7.We present the Holocene sequence from Lago Enol (43°16′N, 4°59′W, 1,070 m a.s.l.), Cantabrian Mountains, northern Spain. A multiproxy analysis provided comprehensive information about regional humidity and temperature changes. The analysis included sedimentological descriptions, physical properties, organic carbon and carbonate content, mineralogy and geochemical composition together with biological proxies including diatom and ostracod assemblages. A detailed pollen study enabled reconstruction of variations in vegetation cover, which were interpreted in the context of climate changes and human impact. Four distinct stages were recognized for the last 13,500 years: (1) a cold and dry episode that includes the Younger Dryas event (13,500–11,600 cal. year BP); (2) a humid and warmer period characterizing the onset of the Holocene (11,600–8,700 cal. year BP); (3) a tendency toward a drier climate during the middle Holocene (8,700–4,650 cal. year BP); and (4) a return to humid conditions following landscape modification by human activity (pastoral activities, deforestation) in the late Holocene (4,650–2,200 cal. year BP). Superimposed on relatively stable landscape conditions (e.g. maintenance of well established forests), the typical environmental variability of the southern European region is observed at this site.The Spanish Inter-Ministry Commission of Science and
Technology (CICYT), the
Spanish National Parks agency, the European Commission, the
Spanish Ministry of Science, and the European
Social Fund
Simple large wood structures promote hydromorphological heterogeneity and benthic macroinvertebrate diversity in low-gradient rivers
This work has been carried out within the SMART Joint Doctorate Programme ‘Science for the MAnagement of Rivers and their Tidal systems’ funded by the Erasmus Mundus programme of the European Union
Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection
We have systematically made a set of precisely defined, single-gene deletions of all nonessential genes in Escherichia coli K-12. Open-reading frame coding regions were replaced with a kanamycin cassette flanked by FLP recognition target sites by using a one-step method for inactivation of chromosomal genes and primers designed to create in-frame deletions upon excision of the resistance cassette. Of 4288 genes targeted, mutants were obtained for 3985. To alleviate problems encountered in high-throughput studies, two independent mutants were saved for every deleted gene. These mutants—the ‘Keio collection'—provide a new resource not only for systematic analyses of unknown gene functions and gene regulatory networks but also for genome-wide testing of mutational effects in a common strain background, E. coli K-12 BW25113. We were unable to disrupt 303 genes, including 37 of unknown function, which are candidates for essential genes. Distribution is being handled via GenoBase (http://ecoli.aist-nara.ac.jp/)
Rotating biological contactors : a review on main factors affecting performance
Rotating biological contactors (RBCs)
constitute a very unique and superior alternative
for biodegradable matter and nitrogen removal on
account of their feasibility, simplicity of design and
operation, short start-up, low land area requirement,
low energy consumption, low operating and maintenance
cost and treatment efficiency. The present
review of RBCs focus on parameters that affect
performance like rotational speed, organic and
hydraulic loading rates, retention time, biofilm support
media, staging, temperature, influent wastewater
characteristics, biofilm characteristics, dissolved oxygen
levels, effluent and solids recirculation, stepfeeding
and medium submergence. Some RBCs
scale-up and design considerations, operational problems
and comparison with other wastewater treatment
systems are also reported.Fundação para a Ciência e a Tecnologia (FCT
Sodium-Glucose Cotransporter-2 Inhibitors and Major Adverse Cardiovascular Outcomes: A SMART-C Collaborative Meta-Analysis
BACKGROUND: Sodium-glucose cotransporter-2 inhibitors (SGLT2i) consistently improve heart failure and kidney-related outcomes; however, effects on major adverse cardiovascular events (MACE) across different patient populations are less clear. METHODS: This was a collaborative trial-level meta-analysis from the SGLT2i Meta-analysis Cardio-Renal Trialists Consortium, which includes all phase 3, placebo-controlled, outcomes trials of SGLT2i across 3 patient populations (patients with diabetes at high risk for atherosclerotic cardiovascular disease, heart failure [HF], or chronic kidney disease). The outcomes of interest were MACE (composite of cardiovascular death, myocardial infarction , or stroke), individual components of MACE (inclusive of fatal and nonfatal events), all-cause mortality, and death subtypes. Effect estimates for SGLT2i versus placebo were meta-analyzed across trials and examined across key subgroups (established atherosclerotic cardiovascular disease, previous myocardial infarction, diabetes, previous HF, albuminuria, chronic kidney disease stages, and risk groups). RESULTS: A total of 78 607 patients across 11 trials were included: 42 568 (54.2%), 20 725 (26.4%), and 15 314 (19.5%) were included from trials of patients with diabetes at high risk for atherosclerotic cardiovascular disease, HF, or chronic kidney disease, respectively. SGLT2i reduced the rate of MACE by 9% (hazard ration [HR], 0.91 [95% CI, 0.87-0.96], P<0.0001) with a consistent effect across all 3 patient populations (I2=0%) and across all key subgroups. This effect was primarily driven by a reduction in cardiovascular death (HR, 0.86 [95% CI, 0.81-0.92], P<0.0001), with no significant effect for myocardial infarction in the overall population (HR, 0.95 [95% CI, 0.87-1.04], P=0.29), and no effect on stroke (HR, 0.99 [95% CI, 0.91-1.07], P=0.77). The benefit for cardiovascular death was driven primarily by reductions in HF death and sudden cardiac death (HR, 0.68 [95% CI, 0.46-1.02] and HR, 0.86 [95% CI, 0.78-0.95], respectively) and was generally consistent across subgroups, with the possible exception of being more apparent in those with albuminuria (Pinteraction=0.02). CONCLUSIONS: SGLT2i reduce the risk of MACE across a broad range of patients irrespective of atherosclerotic cardiovascular disease, diabetes, kidney function, or other major clinical characteristics at baseline. This effect is driven primarily by a reduction of cardiovascular death, particularly HF death and sudden cardiac death, without a significant effect on myocardial infarction in the overall population, and no effect on stroke. These data may help inform selection for SGLT2i therapies across the spectrum of cardiovascular-kidney-metabolic disease
Sodium-Glucose Cotransporter 2 Inhibitors and Risk of Hyperkalemia in People with Type 2 Diabetes: A Meta-Analysis of Individual Participant Data from Randomized, Controlled Trials
Background: Hyperkalemia increases risk of cardiac arrhythmias and death and limits the use of renin-angiotensin-aldosterone system inhibitors and mineralocorticoid receptor antagonists, which improve clinical outcomes in people with chronic kidney disease or systolic heart failure. Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of cardiorenal events in people with type 2 diabetes at high cardiovascular risk or with chronic kidney disease. However, their effect on hyperkalemia has not been systematically evaluated. Methods: A meta-analysis was conducted using individual participant data from randomized, double-blind, placebo-controlled clinical outcome trials with SGLT2 inhibitors in people with type 2 diabetes at high cardiovascular risk or with chronic kidney disease in whom serum potassium levels were routinely measured. The primary outcome was time to serious hyperkalemia, defined as central laboratory-determined serum potassium ≥6.0 mmol/L, with other outcomes including investigator-reported hyperkalemia events and hypokalemia (serum potassium ≤3.5 mmol/L). Cox regression analyses were performed to estimate treatment effects from each trial with hazards ratios and corresponding 95% CIs pooled with random-effects models to obtain summary treatment effects, overall and across key subgroups. Results: Results from 6 trials were included comprising 49 875 participants assessing 4 SGLT2 inhibitors. Of these, 1754 participants developed serious hyperkalemia, and an additional 1119 investigator-reported hyperkalemia events were recorded. SGLT2 inhibitors reduced the risk of serious hyperkalemia (hazard ratio, 0.84 [95% CI, 0.76-0.93]), an effect consistent across studies (Pheterogeneity=0.71). The incidence of investigator-reported hyperkalemia was also lower with SGLT2 inhibitors (hazard ratio, 0.80 [95% CI, 0.68-0.93]; Pheterogeneity=0.21). Reductions in serious hyperkalemia were observed across a range of subgroups, including baseline kidney function, history of heart failure, and use of renin-angiotensin-aldosterone system inhibitor, diuretic, and mineralocorticoid receptor antagonist. SGLT2 inhibitors did not increase the risk of hypokalemia (hazard ratio, 1.04 [95% CI, 0.94-1.15]; Pheterogeneity=0.42). Conclusions: SGLT2 inhibitors reduce the risk of serious hyperkalemia in people with type 2 diabetes at high cardiovascular risk or with chronic kidney disease without increasing the risk of hypokalemia
Acute Treatment Effects on GFR in Randomized Clinical Trials of Kidney Disease Progression
Background Acute changes in GFR can occur after initiation of interventions targeting progression of CKD. These acute changes complicate the interpretation of long-term treatment effects. Methods To assess the magnitude and consistency of acute effects in randomized clinical trials and explore factors that might affect them, we performed a meta-analysis of 53 randomized clinical trials for CKD progression, enrolling 56,413 participants with at least one estimated GFR measurement by 6 months after randomization. We defined acute treatment effects as the mean difference in GFR slope from baseline to 3 months between randomized groups. We performed univariable and multivariable metaregression to assess the effect of intervention type, disease state, baseline GFR, and albuminuria on the magnitude of acute effects. Results The mean acute effect across all studies was 20.21 ml/min per 1.73 m2 (95% confidence interval, 20.63 to 0.22) over 3 months, with substantial heterogeneity across interventions (95% coverage interval across studies, 22.50 to 12.08 ml/min per 1.73 m2). We observed negative average acute effects in renin angiotensin system blockade, BP lowering, and sodium-glucose cotransporter 2 inhibitor trials, and positive acute effects in trials of immunosuppressive agents. Larger negative acute effects were observed in trials with a higher mean baseline GFR. Conclusion The magnitude and consistency of acute GFR effects vary across different interventions, and are larger at higher baseline GFR. Understanding the nature and magnitude of acute effects can help inform the optimal design of randomized clinical trials evaluating disease progression in CKD
Mechanical testing of a device for subcutaneous internal anterior pelvic ring fixation versus external pelvic ring fixation
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