825 research outputs found

    Prospects of herbivore egg-killing plant defenses for sustainable crop protection

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    Due to a growing demand of food production worldwide, new strategies are suggested to allow for sustainable production of food with minimal effects on natural resources. A promising alternative to the application of chemical pesticides is the implementation of crops resistant to insect pests. Plants produce compounds that are harmful to a wide range of attackers, including insect pests; thus, exploitation of their natural defense system can be the key for the development of pest-resistant crops. Interestingly, some plants possess a unique first line of defense that eliminates the enemy before it becomes destructive: egg-killing. Insect eggs can trigger (1) direct defenses, mostly including plant cell tissue growth or cell death that lead to eggs desiccating, being crushed or falling off the plant or (2) indirect defenses, plant chemical cues recruiting natural enemies that kill the egg or hatching larvae (parasitoids). The consequences of plant responses to eggs are that insect larvae do not hatch or that they are impeded in development, and damage to the plant is reduced. Here, we provide an overview on the ubiquity and evolutionary history of egg-killing traits within the plant kingdom including crops. Up to now, little is known on the mechanisms and on the genetic basis of egg-killing traits. Making use of egg-killing defense traits in crops is a promising new way to sustainably reduce losses of crop yield. We provide suggestions for new breeding strategies to grow egg-killing crops and improve biological control

    Relationship of glycaemic control and hypoglycaemic episodes to 4-year cardiovascular outcomes in people with type 2 diabetes starting insulin

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    AIMS: To examine the relationships between glycated haemoglobin (HbA1c) and cardiovascular (CV) events in people beginning insulin in routine clinical practice in Europe, North America and Asia in a non-interventional study, the Cardiovascular Risk Evaluation in people with Type 2 Diabetes on Insulin Therapy (CREDIT) study. METHODS: Data on 2999 people were collected prospectively over 4 years from physician reports. The primary outcome was the composite of stroke or myocardial infarction (MI) or CV-specific death. Events were blindly adjudicated. The relative hazards of CV events were described from Cox proportional hazards models incorporating patient risk factors, with updated average HbA1c as a time-dependent covariate. The relationship of severe and symptomatic hypoglycaemia (collected during the 6 months before yearly ascertainment) with CV and all-cause mortality was examined. RESULTS: A total of 147 primary events were accrued during up to 54 months of follow-up. In all, 60 CV-specific deaths, 44 non-fatal MIs and 57 non-fatal strokes occurred, totalling 161 events. There was a significant positive relationship between updated mean HbA1c and primary outcome: hazard ratio (HR) 1.25 [95% confidence interval (CI) 1.12-1.40; p < 0.0001]. CV death [HR 1.31 (95% CI 1.10-1.57); p = 0.0027] and stroke [HR 1.36 (95% CI 1.17-1.59); p < 0.0001] were both strongly associated with HbA1c, while MI was not [HR 1.05 (95% CI 0.83-1.32)]. One or more severe hypoglycaemic episodes affected 175 participants, while 1508 participants experienced one or more symptomatic hypoglycaemic events. We found no relationship between severe/symptomatic hypoglycaemic events and CV-specific/all-cause death. CONCLUSIONS: Ongoing poorer glucose control was associated with CV events; hypoglycaemia was not associated with CV-specific/all-cause death

    On the global well-posedness of a class of Boussinesq- Navier-Stokes systems

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    In this paper we consider the following 2D Boussinesq-Navier-Stokes systems \partial_{t}u+u\cdot\nabla u+\nabla p+ |D|^{\alpha}u &= \theta e_{2} \partial_{t}\theta+u\cdot\nabla \theta+ |D|^{\beta}\theta &=0 \quad with divu=0\textrm{div} u=0 and 0<β<α<10<\beta<\alpha<1. When 664<α<1\frac{6-\sqrt{6}}{4}<\alpha< 1, 1α<βf(α)1-\alpha<\beta\leq f(\alpha) , where f(α)f(\alpha) is an explicit function as a technical bound, we prove global well-posedness results for rough initial data.Comment: 23page

    Oral health in relation to all-cause mortality: the IPC cohort study

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    We evaluated the association between oral health and mortality. The study population comprised 76,188 subjects aged 16–89 years at recruitment. The mean follow-up time was 3.4 ± 2.4 years. Subjects with a personal medical history of cancer or cardiovascular disease and death by casualty were excluded from the analysis. A full-mouth clinical examination was performed in order to assess dental plaque, dental calculus and gingival inflammation. The number of teeth and functional masticatory units 10 missing teeth and functional masticatory units 10 missing teeth (HR = 2.31, [95% CI: 1.40–3.82]) and functional masticatory units <5 (HR = 2.40 [95% CI 1.55–3.73]). Moreover, when ≥3 oral diseases were cumulated in the model, the risk increased for all-cause mortality (HR = 3.39, [95% CI: 2.51–5.42]), all-cancer mortality (HR = 3.59, [95% CI: 1.23–10.05]) and non-cardiovascular and non-cancer mortality (HR = 4.71, [95% CI: 1.74–12.7]). The present study indicates a postive linear association between oral health and mortality

    A rigorous method for multigenic families' functional annotation: the peptidyl arginine deiminase (PADs) proteins family example

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    BACKGROUND: large scale and reliable proteins' functional annotation is a major challenge in modern biology. Phylogenetic analyses have been shown to be important for such tasks. However, up to now, phylogenetic annotation did not take into account expression data (i.e. ESTs, Microarrays, SAGE, ...). Therefore, integrating such data, like ESTs in phylogenetic annotation could be a major advance in post genomic analyses. We developed an approach enabling the combination of expression data and phylogenetic analysis. To illustrate our method, we used an example protein family, the peptidyl arginine deiminases (PADs), probably implied in Rheumatoid Arthritis. RESULTS: the analysis was performed as follows: we built a phylogeny of PAD proteins from the NCBI's NR protein database. We completed the phylogenetic reconstruction of PADs using an enlarged sequence database containing translations of ESTs contigs. We then extracted all corresponding expression data contained in EST database This analysis allowed us 1/To extend the spectrum of homologs-containing species and to improve the reconstruction of genes' evolutionary history. 2/To deduce an accurate gene expression pattern for each member of this protein family. 3/To show a correlation between paralogous sequences' evolution rate and pattern of tissular expression. CONCLUSION: coupling phylogenetic reconstruction and expression data is a promising way of analysis that could be applied to all multigenic families to investigate the relationship between molecular and transcriptional evolution and to improve functional annotation

    Association Between Clinical Pathways Leading to Medical Management and Prognosis in Patients With NSTEACS.

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    : A large proportion of patients with non-ST-segment elevation acute coronary syndrome (NSTEACS) are initially selected for medical management (MM) and do not undergo coronary revascularization during or immediately after the index event. The aim of this study was to explore the clinical pathways leading to MM in NSTEACS patients and their influence on prognosis. : Patient characteristics, pathways leading to MM, and 2-year outcomes were recorded in a prospective cohort of 5591 NSTEACS patients enrolled in 555 hospitals in 20 countries across Europe and Latin America. Cox models were used to assess the impact of hospital management on postdischarge mortality. : Medical management was the selected strategy in 2306 (41.2%) patients, of whom 669 (29%) had significant coronary artery disease (CAD), 451 (19.6%) had nonsignificant disease, and 1186 (51.4%) did not undergo coronary angiography. Medically managed patients were older and had higher risk features than revascularized patients. Two-year mortality was higher in medically managed patients than in revascularized patients (11.0% vs 4.4%; P &lt; .001), with higher mortality rates in patients who did not undergo angiography (14.6%) and in those with significant CAD (9.3%). Risk-adjusted mortality was highest for patients who did not undergo angiography (HR = 1.81; 95%CI, 1.23-2.65), or were not revascularized in the presence of significant CAD (HR = 1.90; 95%CI, 1.23-2.95) compared with revascularized patients. : Medically managed NSTEACS patients represent a heterogeneous population with distinct risk profiles and outcomes. These differences should be considered when designing future studies in this population.<br/

    B-blockers, calcium antagonists, and mortality in stable coronary artery disease: An international cohort study

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    Aims: The effect of first-line antianginal agents, β-blockers, and calcium antagonists on clinical outcomes in stable coronary artery disease (CAD) remains uncertain. Methods and results We analysed the use of β-blockers or calcium antagonists (baseline and annually) and outcomes in 22 006 stable CAD patients (enrolled 2009–2010) followed annually to 5 years, in the CLARIFY registry (45 countries). Primary outcome was all-cause death. Secondary outcomes were cardiovascular death and the composite of cardiovascular death/non-fatal myocardial infarction (MI). After multivariable adjustment, baseline β-blocker use was not associated with lower all-cause death [1345 (7.8%) in users vs. 407 (8.4%) in non-users; hazard ratio (HR) 0.94, 95% confidence interval (CI) 0.84–1.06; P = 0.30]; cardiovascular death [861 (5.0%) vs. 262 (5.4%); HR 0.91, 95% CI 0.79–1.05; P = 0.20]; or cardiovascular death/non-fatal MI [1272 (7.4%) vs. 340 (7.0%); HR 1.03, 95% CI 0.91–1.16; P = 0.66]. Sensitivity analyses according to β-blocker use over time and to prescribed dose produced similar results. Among prior MI patients, for those enrolled in the year following MI, baseline β-blocker use was associated with lower all-cause death [205 (7.0%) vs. 59 (10.3%); HR 0.68, 95% CI 0.50–0.91; P = 0.01]; cardiovascular death [132 (4.5%) vs. 49 (8.5%); HR 0.52, 95% CI 0.37–0.73; P = 0.0001]; and cardiovascular death/non-fatal MI [212 (7.2%) vs. 59 (10.3%); HR 0.69, 95% CI 0.52–0.93; P = 0.01]. Calcium antagonists were not associated with any difference in mortality. Conclusion In this contemporary cohort of stable CAD, β-blocker use was associated with lower 5-year mortality only in patients enrolled in the year following MI. Use of calcium antagonists was not associated with superior mortality, regardless of history of MI

    Interaction of vortices in viscous planar flows

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    We consider the inviscid limit for the two-dimensional incompressible Navier-Stokes equation in the particular case where the initial flow is a finite collection of point vortices. We suppose that the initial positions and the circulations of the vortices do not depend on the viscosity parameter \nu, and we choose a time T > 0 such that the Helmholtz-Kirchhoff point vortex system is well-posed on the interval [0,T]. Under these assumptions, we prove that the solution of the Navier-Stokes equation converges, as \nu -> 0, to a superposition of Lamb-Oseen vortices whose centers evolve according to a viscous regularization of the point vortex system. Convergence holds uniformly in time, in a strong topology which allows to give an accurate description of the asymptotic profile of each individual vortex. In particular, we compute to leading order the deformations of the vortices due to mutual interactions. This allows to estimate the self-interactions, which play an important role in the convergence proof.Comment: 39 pages, 1 figur
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