Explore the vast range of titles available.

Percutaneous coronary intervention of severely calcified lesions has historically been associated with major adverse cardiac event (MACE) rates as high as 30%. In the ORBIT II (Evaluate the Safety and Efficacy of OAS in Treating Severely Calcified Coronary Lesions) trial, treatment of de novo severely calcified lesions with the Diamondback 360° Coronary Orbital Atherectomy System (OAS) resulted in low rates of procedural and 30-day adverse ischemic events. The long-term results from this trial have not been reported. We sought to determine the 1-year outcomes after orbital atherectomy of severely calcified coronary lesions. ORBIT II was a single-arm trial enrolling 443 subjects at 49 US sites with severely calcified lesions usually excluded from randomized trials. OAS utilizes a centrifugal differential sanding mechanism of action for plaque modification prior to stent implantation. After OAS drug-eluting stents were implanted in 88.2% of the patients. The primary safety end point was 30-day MACE, the composite of cardiac death, myocardial infarction, or target vessel revascularization [TVR]. The present analysis reports the 1-year follow-up results from ORBIT II. One-year data were available in 433 of 443 patients (97.7%), with median follow-up time of 16.7 months. The 1-year MACE rate was 16.4%, including cardiac death (3.0%), myocardial infarction (9.7%), and target vessel revascularization (5.9%). The 1-year target lesion revascularization rate was 4.7%, and stent thrombosis occurred in 1 patient (0.2%). Independent predictors of 1-year MACE and target vessel revascularization were diameter stenosis at baseline and the use of bare-metal stents. In patients with severely calcified lesions who underwent percutaneous coronary intervention, the use of OAS was associated with low rates of 1-year adverse ischemic events compared with historical controls. This finding has important clinical implications for the selection of optimum treatment strategies for patients with severely calcified lesions.

Isoprene (Is) emissions by plants represent a loss of carbon and energy resources leading to the initial hypothesis that fast growing pioneer species in secondary tropical forests allocate carbon primarily to growth at the expense of isoprenoid defenses. In this study, we quantified leaf isoprene and methanol emissions from the abundant pantropical pioneer tree species Vismia guianensis and ambient isoprene concentrations above a diverse secondary forest in the central Amazon. As photosynthetically active radiation (PAR) was varied (0 to 3000 µmol m−2 s−1) under standard leaf temperature (30 °C), isoprene emissions from V. guianensis increased without saturation up to 80 nmol m−2 s−1. A nonlinear increase in isoprene emissions with respect to net photosynthesis (Pn) resulted in the fraction of Pn dedicated to isoprene emissions increasing with light intensity (up to 2 % of Pn). Emission responses to temperature under standard light conditions (PAR of 1000 µmol m−2 s−1) resulted in the classic uncoupling of isoprene emissions (Topt, iso > 40 °C) from net photosynthesis (Topt, Pn = 30.0–32.5 °C) with up to 7 % of Pn emitted as isoprene at 40 °C. Under standard environmental conditions of PAR and leaf temperature, young V. guianensis leaves showed high methanol emissions, low Pn, and low isoprene emissions. In contrast, mature leaves showed high Pn, high isoprene emissions, and low methanol emissions, highlighting the differential control of leaf phenology over methanol and isoprene emissions. High daytime ambient isoprene concentrations (11 ppbv) were observed above a secondary Amazon rainforest, suggesting that isoprene emissions are common among neotropical pioneer species. The results are not consistent with the initial hypothesis and support a functional role of methanol during leaf expansion and the establishment of photosynthetic machinery and a protective role of isoprene for photosynthesis during high temperature extremes regularly experienced in secondary rainforest ecosystems.

In order to extend the study of community social disorganization and crime beyond its exclusive focus on large urban centers, we present an analysis of structural correlates of arrest rates for juvenile violence in 264 nonmetropolitan counties of four states. Findings support the generality of social disorganization theory: Juvenile violence was associated with rates of residential instability, family disruption, and ethnic heterogeneity. Though rates of poverty were not related to juvenile violence, this is also in accord with social disorganization theory because, unlike urban settings, poverty was negatively related to residential instability. Rates of juvenile violence varied markedly with population size through a curvilinear relationship in which counties with the smallest juvenile populations had exceptionally low arrest rates. Analyses used negative binomial regression (a variation of Poisson regression) because the small number of arrests in many counties meant that arrest rates would be ill suited to least‐squares regression.

Tree mortality rates appear to be increasing in moist tropical forests (MTFs) with significant carbon cycle consequences. Here, we review the state of knowledge regarding MTF tree mortality, create a conceptual framework with testable hypotheses regarding the drivers, mechanisms and interactions that may underlie increasing MTF mortality rates, and identify the next steps for improved understanding and reduced prediction. Increasing mortality rates are associated with rising temperature and vapor pressure deficit, liana abundance, drought, wind events, fire and, possibly, CO2 fertilization-induced increases in stand thinning or acceleration of trees reaching larger, more vulnerable heights. The majority of these mortality drivers may kill trees in part through carbon starvation and hydraulic failure. The relative importance of each driver is unknown. High species diversity may buffer MTFs against large-scale mortality events, but recent and expected trends in mortality drivers give reason for concern regarding increasing mortality within MTFs. Models of tropical tree mortality are advancing the representation of hydraulics, carbon and demography, but require more empirical knowledge regarding the most common drivers and their subsequent mechanisms. We outline critical datasets and model developments required to test hypotheses regarding the underlying causes of increasing MTF mortality rates, and improve prediction of future mortality under climate change.

Deep-water access is arguably the most effective, but under-studied, mechanism that plants employ to survive during drought. Vulnerability to embolism and hydraulic safety margins can predict mortality risk at given levels of dehydration, but deep-water access may delay plant dehydration. Here, we tested the role of deep-water access in enabling survival within a diverse tropical forest community in Panama using a novel data-model approach.We inversely estimated the effective rooting depth (ERD, as the average depth of water extraction), for 29 canopy species by linking diameter growth dynamics (1990-2015) to vapor pressure deficit, water potentials in the whole-soil column, and leaf hydraulic vulnerability curves. We validated ERD estimates against existing isotopic data of potential water-access depths.Across species, deeper ERD was associated with higher maximum stem hydraulic conductivity, greater vulnerability to xylem embolism, narrower safety margins, and lower mortality rates during extreme droughts over 35 years (1981-2015) among evergreen species. Species exposure to water stress declined with deeper ERD indicating that trees compensate for water stress-related mortality risk through deep-water access.The role of deep-water access in mitigating mortality of hydraulically-vulnerable trees has important implications for our predictive understanding of forest dynamics under current and future climates.

Coronary artery calcification is common among patients undergoing percutaneous coronary intervention (PCI), and severe coronary artery lesion calcification is associated with increased procedural complexity, stent under-expansion, and high rates of intraprocedural complications and out-of-hospital adverse events. Whether calcium ablation before stent implantation can mitigate these adverse events is not currently established. We aimed to prospectively compare orbital atherectomy with a balloon angioplasty-based strategy before stent implantation for the treatment of severely calcified coronary lesions. In this multicentre, open-label, randomised controlled trial conducted at 104 medical centres in the USA, patients (aged ≥18 years) with severely calcified coronary lesions were randomly assigned (1:1) to orbital atherectomy or balloon angioplasty before PCI with drug-eluting stents using a web-based system (block sizes of four and six) and stratified by intended treatment of single versus multiple lesions and enrolling site. Randomly assigned lesions were deemed by operators to be eligible for both treatment strategies. Operators and patients were not masked to treatment. The two powered coprimary study endpoints were target vessel failure at 1 year (a composite of cardiac death, target vessel myocardial infarction, or ischaemia-driven target vessel revascularisation) and post-procedural minimal stent area at the site of maximal calcification, as assessed by intravascular optical coherence tomography in an imaging patient cohort. Primary analyses were by intention-to-treat. The trial is registered at ClinicalTrials.govNCT03108456, and 2-year follow-up is ongoing. From March 27, 2017, to April 13, 2023, 2005 patients with 2492 lesions were randomly assigned to lesion preparation with orbital atherectomy (1008 patients with 1250 lesions) or balloon angioplasty (997 with 1242 lesions) before stent implantation. Median patient age was 70·0 years (IQR 64·0–76·0). 541 (27·0%) of 2005 patients were female and 1464 (73·0%) were male. Angiographically severe calcium was confirmed by the core laboratory in 1088 (97·1%) of 1120 lesions assigned to orbital atherectomy and 1068 (97·0%) of 1101 lesions assigned to balloon angioplasty. PCI was guided by intravascular imaging in 627 (62·2%) of 1008 patients in the orbital atherectomy group and 619 (62·1%) of 997 in the balloon angioplasty group. Target vessel failure events within 1 year occurred in 113 of 1008 patients in the orbital atherectomy group (1-year target vessel failure 11·5% [95% CI 9·7 to 13·7]) and in 97 of 997 patients in the balloon angioplasty group (10·0% [8·3 to 12·1]; absolute difference 1·5% [96% CI –1·4 to 4·4]; hazard ratio 1·16 [96% CI 0·87 to 1·54], p=0·28). Among those in the optical coherence tomography substudy cohort (276 patients with 286 lesions in the orbital atherectomy group and 279 patients with 292 lesions in the balloon angioplasty group), the mean minimal stent area at the site of maximal calcification was 7·67 mm2 (SD 2·27) in the orbital atherectomy group and 7·42 mm2 (2·54) in the balloon angioplasty group (mean difference 0·26 [99% CI –0·31 to 0·82]; p=0·078). Cardiac death events within 1 year occurred in 39 of 1008 patients in the orbital atherectomy group and in 26 of 997 in the balloon angioplasty group. Routine treatment with orbital atherectomy before drug-eluting stent implantation did not increase minimal stent area or reduce the rate of target vessel failure at 1 year compared with a balloon angioplasty-based approach in severely calcified lesions deemed eligible for both treatment strategies. These data support a balloon-first approach for most calcified coronary artery lesions that can be crossed and dilated before stent implantation, guided by intravascular imaging. Abbott Vascular (Abbott).

Isoprene (Is) emissions by plants represent a loss of carbon and energy resources leading to the initial hypothesis that fast growing pioneer species in secondary tropical forests allocate carbon primarily to growth at the expense of isoprenoid defenses. In this study, we quantified leaf isoprene and methanol emissions from the abundant pantropical pioneer tree species Vismia guianensis and ambient isoprene concentrations above a diverse secondary forest in the central Amazon. As photosynthetically active radiation (PAR) was varied (0 to 3000 µmol m.sup.-2  s.sup.-1) under standard leaf temperature (30 °C), isoprene emissions from V. guianensis increased without saturation up to 80 nmol m.sup.-2  s.sup.-1 . A nonlinear increase in isoprene emissions with respect to net photosynthesis (Pn) resulted in the fraction of Pn dedicated to isoprene emissions increasing with light intensity (up to 2 % of Pn). Emission responses to temperature under standard light conditions (PAR of 1000 µmol m.sup.-2  s.sup.-1) resulted in the classic uncoupling of isoprene emissions (T.sub.opt, iso  > 40 °C) from net photosynthesis (T.sub.opt, Pn  = 30.0-32.5 °C) with up to 7 % of Pn emitted as isoprene at 40 °C. Under standard environmental conditions of PAR and leaf temperature, young V. guianensis leaves showed high methanol emissions, low Pn, and low isoprene emissions. In contrast, mature leaves showed high Pn, high isoprene emissions, and low methanol emissions, highlighting the differential control of leaf phenology over methanol and isoprene emissions. High daytime ambient isoprene concentrations (11 ppbv) were observed above a secondary Amazon rainforest, suggesting that isoprene emissions are common among neotropical pioneer species. The results are not consistent with the initial hypothesis and support a functional role of methanol during leaf expansion and the establishment of photosynthetic machinery and a protective role of isoprene for photosynthesis during high temperature extremes regularly experienced in secondary rainforest ecosystems.

In order to extend the study of community social disorganization & crime beyond its exclusive focus on large urban centers, we present an analysis of structural correlates of arrest rates for juvenile violence in 264 nonmetropolitan counties of four states. Findings support the generality of social disorganization theory: juvenile violence was associated with rates of residential instability, family disruption, & ethnic heterogeneity. Though rates of poverty were not related to juvenile violence, this is also in accord with social disorganization theory because, unlike urban settings, poverty was negatively related to residential instability. Rates of juvenile violence varied markedly with population size through a curvilinear relationship in which counties with the smallest juvenile populations had exceptionally low arrest rates. Analyses used negative binomial regression (a variation of Poisson regression) because the small number of arrests in many counties meant that arrest rates would be ill suited to least-squares regression. Adapted from the source document.