Taxonomic identification of Amazonian tree crowns from aerial photography

Question: To what extent can aerial photography be used for taxonomic identification of Amazonian tree crowns? Objective: To investigate whether a combination of dichotomous keys and a web-based interface is a suitable approach to identify tree crowns. Location: The fieldwork was conducted at Tiputini Biodiversity Station located in the Amazon, eastern Ecuador. Methods: High-resolution imagery was taken from an airplane flying at a low altitude (600 m) above the ground. Imagery of the observable upper layer of the tree crowns was used for the analysis. Dichotomous identification keys for different types of crowns were produced and tested. The identification keys were designed to be web-based interactive, using Google Earth as the main online platform. The taxa analysed were Iriartea, Astrocaryum, Inga, Parkia, Cecropia, Pourouma, Guarea, Otoba, Lauraceae and Pouteria. Results: This paper demonstrates that a combination of photo-imagery, dichotomous keys and a web-based interface can be useful for the taxonomic identification of Amazonian trees based on their crown characteristics. The keys tested with an overall identification accuracy of over 50% for five of the ten taxa with three of them showing accuracy greater than 70% (Iriartea, Astrocaryum and Cecropia). Conclusions: The application of dichotomous keys and a web-based interface provides a new methodological approach for taxonomic identification of various Amazonian tree crowns. Overall, the study showed that crowns with a medium-rough texture are less reliably identified than crowns with smoother or well-defined surfaces

Assessing functional mitral regurgitation with exercise echocardiography: rationale and clinical applications

Secondary or functional mitral regurgitation (FMR) represents an increasing feature of mitral valve disease characterized by abnormal function of anatomically normal leaflets in the context of the impaired function of remodelled left ventricles. The anatomic and pathophysiological basis of FMR are briefly analyzed; in addition, the role of exercise echocardiography for the assessment of FMR is discussed in view of its relevance to clinical practice

Baseline mitral regurgitation predicts outcome in patients referred for dobutamine stress echocardiography

Purpose: A number of parameters recorded during dobutamine stress echocardiography (DSE) are associated with worse outcome. However, the relative importance of baseline mitral regurgitation (MR) is unknown. The aim of this study was to assess the prevalence and associated implications of functional MR with long-term mortality in a large cohort of patients referred for DSE. Methods: 6745 patients (mean age 64.9±12.2 years) were studied. Demographic, baseline and peak DSE data were collected. All-cause mortality was retrospectively analyzed. DSE was successfully completed in all patients with no adverse outcomes. Results: MR was present in 1019 (15.1%) patients. During a mean follow up of 5.1±1.8 years, 1642 (24.3%) patients died and MR was significantly associated with increased all-cause mortality (p<0.001). With Kaplan-Meier analysis, survival was significantly worse for patients with moderate and severe MR (p<0.001). With multivariate Cox regression analysis, moderate and severe MR (HR 2.78; 95% CI 2.17 - 3.57; and HR 3.62; 95% CI 2.89 - 4.53, respectively) were independently associated with all-cause mortality. The addition of MR to C statistic models significantly improved discrimination. Conclusions: MR is associated with all-cause mortality and adds incremental prognostic information among patients referred for DSE. The presence of MR should be taken into account when evaluating the prognostic significance of DSE results

Baseline characteristics of patients in the reduction of events with darbepoetin alfa in heart failure trial (RED-HF)

&lt;p&gt;Aims: This report describes the baseline characteristics of patients in the Reduction of Events with Darbepoetin alfa in Heart Failure trial (RED-HF) which is testing the hypothesis that anaemia correction with darbepoetin alfa will reduce the composite endpoint of death from any cause or hospital admission for worsening heart failure, and improve other outcomes.&lt;/p&gt; &lt;p&gt;Methods and results: Key demographic, clinical, and laboratory findings, along with baseline treatment, are reported and compared with those of patients in other recent clinical trials in heart failure. Compared with other recent trials, RED-HF enrolled more elderly [mean age 70 (SD 11.4) years], female (41%), and black (9%) patients. RED-HF patients more often had diabetes (46%) and renal impairment (72% had an estimated glomerular filtration rate &#60;60 mL/min/1.73 m2). Patients in RED-HF had heart failure of longer duration [5.3 (5.4) years], worse NYHA class (35% II, 63% III, and 2% IV), and more signs of congestion. Mean EF was 30% (6.8%). RED-HF patients were well treated at randomization, and pharmacological therapy at baseline was broadly similar to that of other recent trials, taking account of study-specific inclusion/exclusion criteria. Median (interquartile range) haemoglobin at baseline was 112 (106–117) g/L.&lt;/p&gt; &lt;p&gt;Conclusion: The anaemic patients enrolled in RED-HF were older, moderately to markedly symptomatic, and had extensive co-morbidity.&lt;/p&gt

Combination therapy with oral treprostinil for pulmonary arterial hypertension. A double-blind placebo-controlled clinical trial

Rationale: Oral treprostinil improves exercise capacity in patients with pulmonary arterial hypertension (PAH), but the effect on clinical outcomes was unknown. Objectives: To evaluate the effect of oral treprostinil compared with placebo on time to first adjudicated clinical worsening event in participants with PAH who recently began approved oral monotherapy. Methods: In this event-driven, double-blind study, we randomly allocated 690 participants (1:1 ratio) with PAH to receive placebo or oral treprostinil extended-release tablets three times daily. Eligible participants were using approved oral monotherapy for over 30 days before randomization and had a 6-minute-walk distance 150 m or greater. The primary endpoint was the time to first adjudicated clinical worsening event: death; hospitalization due to worsening PAH; initiation of inhaled or parenteral prostacyclin therapy; disease progression; or unsatisfactory long-term clinical response. Measurements and Main Results: Clinical worsening occurred in 26% of the oral treprostinil group compared with 36% of placebo participants (hazard ratio, 0.74; 95% confidence interval, 0.56–0.97; P = 0.028). Key measures of disease status, including functional class, Borg dyspnea score, and N-terminal pro–brain natriuretic peptide, all favored oral treprostinil treatment at Week 24 and beyond. A noninvasive risk stratification analysis demonstrated that oral treprostinil–assigned participants had a substantially higher mortality risk at baseline but achieved a lower risk profile from Study Weeks 12–60. The most common adverse events in the oral treprostinil group were headache, diarrhea, flushing, nausea, and vomiting. Conclusions: In participants with PAH, addition of oral treprostinil to approved oral monotherapy reduced the risk of clinical worsening. Clinical trial registered with www.clinicaltrials.gov (NCT01560624)

Hétérogénéité spatiale d'une forêt tropicale humide de Sumatra : effet de la topographie sur la structure floristique

International audienc

Hétérogénéité spatiale d'une forêt tropicale humide de Sumatra : effet de la topographie sur la structure floristique

Spatial heterogeneity of a tropical rain forest in Sumatra: effect of topography on floristic structure. Tropical rain forests are characterized by a complex and spatially heterogeneous structure. It is essential to analyze the factors of this heterogeneity in order to set up sustainable management policies in these environments. We have studied the influence of topography on floristic structure, considering 3 ha of forest with contrasted relief. Correspondance analysis has shown that topography acts through drainage, leading to different specific compositions on ridge, slope and valley. It operates also in relation to forest dynamics, favouring pioneer species on steep slopes. In addition, this influence decreases as topographic heterogeneity is reduced; other factors related to forest internal characteristics then govern floristic structure. Moreover, this study brings new data concerning floristic composition and ecology of forests in this area, as well as topographical preferences of many species. Topography appears to be a key factor regarding the structure and the dynamics of tropical rain forests on contrasted relief, and should be considered in modelling.Les forêts tropicales humides se caractérisent par une structure complexe très hétérogène dans l'espace. L'étude des facteurs responsables de cette hétérogénéité est indispensable si l'on veut mettre en place des aménagements durables dans ces milieux. À Sumatra, sur une parcelle forestière de 3 ha au relief contrasté, nous avons étudié l'influence de la topographic sur l'hétérogénéité spatiale de la structure floristique. Les résultats d'une analyse factorielle des correspondances montrent que la topographie intervient par le biais du drainage, en induisant une composition spécifique différente entre vallée, pente et crête. Elle intervient aussi en relation avec le cycle sylvigénétique, en favorisant la présence d'espèces pionnières sur de fortes pentes. L'analyse montre encore que cette influence s'estompe lorsque le niveau d'hétérogénéité du terrain diminue, et que d'autres facteurs liés aux particularités internes à la forêt (dynamique naturelle, diversité spécifique...) régissent alors la structure floristique. Cette étude apporte des données nouvelles sur la composition floristique et l'écologie des forêts de cette région, ainsi que sur les préférences topographiques de nombreuses espèces d'arbres. La topographie apparaît comme un facteur clé de la structure et de la dynamique des forêts tropicales humides sur terrain accidenté, et elle devrait être prise en compte dans leur modélisation