50 research outputs found

    Plant trait and vegetation data along a 1314 m elevation gradient with fire history in Puna grasslands, Perú

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    Alpine grassland vegetation supports globally important biodiversity and ecosystems that are increasingly threatened by climate warming and other environmental changes. Trait-based approaches can support understanding of vegetation responses to global change drivers and consequences for ecosystem functioning. In six sites along a 1314 m elevational gradient in Puna grasslands in the Peruvian Andes, we collected datasets on vascular plant composition, plant functional traits, biomass, ecosystem fluxes, and climate data over three years. The data were collected in the wet and dry season and from plots with different fire histories. We selected traits associated with plant resource use, growth, and life history strategies (leaf area, leaf dry/wet mass, leaf thickness, specific leaf area, leaf dry matter content, leaf C, N, P content, C and N isotopes). The trait dataset contains 3,665 plant records from 145 taxa, 54,036 trait measurements (increasing the trait data coverage of the regional flora by 420%) covering 14 traits and 121 plant taxa (ca. 40% of which have no previous publicly available trait data) across 33 families

    Plant trait and vegetation data along a 1314 m elevation gradient with fire history in Puna grasslands, Per\ufa

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    \ua9 2024. The Author(s). Alpine grassland vegetation supports globally important biodiversity and ecosystems that are increasingly threatened by climate warming and other environmental changes. Trait-based approaches can support understanding of vegetation responses to global change drivers and consequences for ecosystem functioning. In six sites along a 1314 m elevational gradient in Puna grasslands in the Peruvian Andes, we collected datasets on vascular plant composition, plant functional traits, biomass, ecosystem fluxes, and climate data over three years. The data were collected in the wet and dry season and from plots with different fire histories. We selected traits associated with plant resource use, growth, and life history strategies (leaf area, leaf dry/wet mass, leaf thickness, specific leaf area, leaf dry matter content, leaf C, N, P content, C and N isotopes). The trait dataset contains 3,665 plant records from 145 taxa, 54,036 trait measurements (increasing the trait data coverage of the regional flora by 420%) covering 14 traits and 121 plant taxa (ca. 40% of which have no previous publicly available trait data) across 33 families

    Effects of alirocumab on types of myocardial infarction: insights from the ODYSSEY OUTCOMES trial

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    Aims  The third Universal Definition of Myocardial Infarction (MI) Task Force classified MIs into five types: Type 1, spontaneous; Type 2, related to oxygen supply/demand imbalance; Type 3, fatal without ascertainment of cardiac biomarkers; Type 4, related to percutaneous coronary intervention; and Type 5, related to coronary artery bypass surgery. Low-density lipoprotein cholesterol (LDL-C) reduction with statins and proprotein convertase subtilisin–kexin Type 9 (PCSK9) inhibitors reduces risk of MI, but less is known about effects on types of MI. ODYSSEY OUTCOMES compared the PCSK9 inhibitor alirocumab with placebo in 18 924 patients with recent acute coronary syndrome (ACS) and elevated LDL-C (≥1.8 mmol/L) despite intensive statin therapy. In a pre-specified analysis, we assessed the effects of alirocumab on types of MI. Methods and results  Median follow-up was 2.8 years. Myocardial infarction types were prospectively adjudicated and classified. Of 1860 total MIs, 1223 (65.8%) were adjudicated as Type 1, 386 (20.8%) as Type 2, and 244 (13.1%) as Type 4. Few events were Type 3 (n = 2) or Type 5 (n = 5). Alirocumab reduced first MIs [hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.77–0.95; P = 0.003], with reductions in both Type 1 (HR 0.87, 95% CI 0.77–0.99; P = 0.032) and Type 2 (0.77, 0.61–0.97; P = 0.025), but not Type 4 MI. Conclusion  After ACS, alirocumab added to intensive statin therapy favourably impacted on Type 1 and 2 MIs. The data indicate for the first time that a lipid-lowering therapy can attenuate the risk of Type 2 MI. Low-density lipoprotein cholesterol reduction below levels achievable with statins is an effective preventive strategy for both MI types.For complete list of authors see http://dx.doi.org/10.1093/eurheartj/ehz299</p

    Effect of alirocumab on mortality after acute coronary syndromes. An analysis of the ODYSSEY OUTCOMES randomized clinical trial

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    Background: Previous trials of PCSK9 (proprotein convertase subtilisin-kexin type 9) inhibitors demonstrated reductions in major adverse cardiovascular events, but not death. We assessed the effects of alirocumab on death after index acute coronary syndrome. Methods: ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) was a double-blind, randomized comparison of alirocumab or placebo in 18 924 patients who had an ACS 1 to 12 months previously and elevated atherogenic lipoproteins despite intensive statin therapy. Alirocumab dose was blindly titrated to target achieved low-density lipoprotein cholesterol (LDL-C) between 25 and 50 mg/dL. We examined the effects of treatment on all-cause death and its components, cardiovascular and noncardiovascular death, with log-rank testing. Joint semiparametric models tested associations between nonfatal cardiovascular events and cardiovascular or noncardiovascular death. Results: Median follow-up was 2.8 years. Death occurred in 334 (3.5%) and 392 (4.1%) patients, respectively, in the alirocumab and placebo groups (hazard ratio [HR], 0.85; 95% CI, 0.73 to 0.98; P=0.03, nominal P value). This resulted from nonsignificantly fewer cardiovascular (240 [2.5%] vs 271 [2.9%]; HR, 0.88; 95% CI, 0.74 to 1.05; P=0.15) and noncardiovascular (94 [1.0%] vs 121 [1.3%]; HR, 0.77; 95% CI, 0.59 to 1.01; P=0.06) deaths with alirocumab. In a prespecified analysis of 8242 patients eligible for ≥3 years follow-up, alirocumab reduced death (HR, 0.78; 95% CI, 0.65 to 0.94; P=0.01). Patients with nonfatal cardiovascular events were at increased risk for cardiovascular and noncardiovascular deaths (P<0.0001 for the associations). Alirocumab reduced total nonfatal cardiovascular events (P<0.001) and thereby may have attenuated the number of cardiovascular and noncardiovascular deaths. A post hoc analysis found that, compared to patients with lower LDL-C, patients with baseline LDL-C ≥100 mg/dL (2.59 mmol/L) had a greater absolute risk of death and a larger mortality benefit from alirocumab (HR, 0.71; 95% CI, 0.56 to 0.90; Pinteraction=0.007). In the alirocumab group, all-cause death declined wit h achieved LDL-C at 4 months of treatment, to a level of approximately 30 mg/dL (adjusted P=0.017 for linear trend). Conclusions: Alirocumab added to intensive statin therapy has the potential to reduce death after acute coronary syndrome, particularly if treatment is maintained for ≥3 years, if baseline LDL-C is ≥100 mg/dL, or if achieved LDL-C is low. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01663402

    Evolution of Pre-Columbian Metallurgy from the North of Peru’ Studied with a Portable Non-Invasive Equipment Using Energy-Dispersive X-Ray Fluorescence

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    On the north coast of present-day Peru, between the Andes and the Pacific Ocean, prospered approximately between 1000 BC and 1375 AD, several relevant cultures: Chavín (1000-200 BC), Vicús and Frías (200 BC - 300 AD), Moche (400 BC-700 AD), Sicán (700-1375 AD). These cultures are interconnected and characterized by a high metallurgical ability, demonstrated by the presence of beautiful artifacts on gold, silver and copper alloys. More than hundred metal artefacts from these cultures were analyzed with a portable equipment which uses the non-destructive and non-invasive technique of energy-dispersive X-ray fluorescence (EDXRF). Following objects were analyzed: (1) gold, silver and copper objects from the Chavín culture (Museo Municipal of Piura and and Museo Enrico Poli in Lima); (2) gold and silver objects from the Vicús and Frías cultures (Museo Municipal of Piura); (3) gold, silver and copper objects from the Moche culture (“Museo Tumbas Reales de Sipán”, “Museo de Sitio de Huaca Rajada” in Lambayeque and Museo Enrico Poli in Lima); (4) gold, silver and copper objects from the Sicán culture (Museum of Sicán, Ferrañafe). Portable equipments were employed, mainly composed of a small size X-ray tube and a thermoelectrically cooled, small size, Si-PIN or Si-drift X-ray detectors. The main characteristics of the EDXRF-technique is of being non destructive and multi-elemental. Standard samples of gold and silver alloys were employed for calibration and quantitative analysis. The aims of this campaign of analysis were: (1) to analyze a large number of objects; (2) to differentiate gold, gilded copper and tumbaga (this last being a poor gold alloy enriched at the surface by depletion gilding); (3) to correlate, when possible, composition of analyzed alloys to the specific culture; (4) to determine a possible evolution of metallurgy; (5) to better determine characteristics and beginning time of tumbaga production. It was determined that the analyzed artefacts are composed of gold, silver and copper alloys, of gilded copper or silver and tumbaga, the last being a poor gold-alloy rich on copper and enriched at the surface by depletion gilding, i.e. by removing copper from the surface. About 120 alloys were analyzed. In the case of gold, silver and copper alloys, their composition was determined by EDXRF-analysis by employing standard alloys. In the case of gilded copper (or gilded silver) and of copper based tumbaga, the ratios Cu(Kα/Kβ) andAu(Lα/Lβ) were determined from the X-ray spectra, first to clearly differentiate gold, gilded metal and tumbaga, and then to determine the gilding thickness. Concerning the correlation composition-culture, it seems that the Chavín did not use to mix copper in the gold alloy. This element, with a mean concentration of 1.5%, is only present in Au-alloys as in nature. Further, silver was measured in all cultures of the north of Peru at relatively high levels of purity, but by the Chavín was associated to Cu and Pb, by the Moche to Cu and Au, by the Sicán to Cu, Au, Pb and Br. Also copper was measured in all cultures of the north of Peru at high levels of purity. However, this element seems to contain small quantities of Zn by the Chavín, is almost pure by the Moche, and contains as by the Sicán. With reference to copper based tumbaga, it is not clear when it was “produced” for the first time in the north of Peru, may be by the Vicús; in any the largest number of tumbaga was produced by the Moche, and are characterized by a mean “equivalent” Au-thickness of ~2.5 μm
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