522 research outputs found

    Forest vegetation management in Europe: current practice and future requirements

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    The book provides a record of the co-operation within Europe in the field of forest vegetation management through the Cost Action E47. The aims are: i)to provide a summary of the current state of the art' as it applies to forest vegetation management in Europe for scientists, practitioners and policymakers, affiliated to state, non-governmental or private commercial organizations; ii)to document existing forest weed control practices across Europe, and hence provide a resource of alternative solutions for individual countries sharing similar conditions and challenges; and iii)to identify common information gaps and future research needs, and hence potential future areas of collaboration for forest vegetation management scientists across Europe, along with barriers that may need to be overcome to achieve that aim.FORET;PEUPLEMENT FORESTIER;VEGETATION;CONCURRENCE VEGETALE;LUTTE;MODE DE TRAITEMENT;COOPERATION INTERNATIONALE;RECHERCHE DEVELOPPEMENT;DEVELOPPEMENT DURABLE;AMENAGEMENT FORESTIER;MAUVAISE HERBE;CONTROLE DE LA VEGETATION;PESTICIDE;LUTTE PHYTOSANITAIRE;IMPACT SUR L'ENVIRONNEMENT;DYNAMIQUE DE VEGETATION;HERBICIDE;BIODIVERSITE;ECOSYSTEME;HISTOIRE;GESTION FORESTIERE;EUROPE;VEGETATION FORESTIERE;ADVENTICE;ALTERNATIVES AUX HERBICIDES;

    Terminalia bentzoë, a Mascarene Endemic Plant, Inhibits Human Hepatocellular Carcinoma Cells Growth In Vitro via G0/G1 Phase Cell Cycle Arrest

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    Tropical forests constitute a prolific sanctuary of unique floral diversity and potential medicinal sources, however, many of them remain unexplored. The scarcity of rigorous scientific data on the surviving Mascarene endemic taxa renders bioprospecting of this untapped resource of utmost importance. Thus, in view of valorizing the native resource, this study has as its objective to investigate the bioactivities of endemic leaf extracts. Herein, seven Mascarene endemic plants leaves were extracted and evaluated for their in vitro antioxidant properties and antiproliferative effects on a panel of cancer cell lines, using methyl thiazolyl diphenyl-tetrazolium bromide (MTT) and clonogenic cell survival assays. Flow cytometry and comet assay were used to investigate the cell cycle and DNA damaging effects, respectively. Bioassay guided-fractionation coupled with liquid chromatography mass spectrometry (MS), gas chromatography-MS, and nuclear magnetic resonance spectroscopic analysis were used to identify the bioactive compounds. Among the seven plants tested, Terminaliabentzoë was comparatively the most potent antioxidant extract, with significantly (p < 0.05) higher cytotoxic activities. T. bentzoë extract further selectively suppressed the growth of human hepatocellular carcinoma cells and significantly halted the cell cycle progression in the G0/G1 phase, decreased the cells’ replicative potential and induced significant DNA damage. In total, 10 phenolic compounds, including punicalagin and ellagic acid, were identified and likely contributed to the extract’s potent antioxidant and cytotoxic activities. These results established a promising basis for further in-depth investigations into the potential use of T. bentzoë as a supportive therapy in cancer management

    Growth and characterization of heteroepitaxial La-substituted BaSnO3_3 films on SrTiO3_3 (001) and SmScO3_3 (110) substrates

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    Heteroepitaxial growth of BaSnO3_3 (BSO) and Ba1x_{1-x}Lax_xSnO3_3 (x = 7 %) (LBSO) thin films on different perovskite single crystal (SrTiO3_3 (001) and SmScO3_3 (110)) substrates has been achieved by Pulsed Laser Deposition (PLD) under optimized deposition conditions. X-ray diffraction measurements indicate that the films on either of these substrates are relaxed due to the large mismatch and present a high degree of crystallinity with narrow rocking curves and smooth surface morphology while analytical quantification by proton induced x-ray emission (PIXE) confirms the stoichiometric La transfer from a polyphasic target, producing films with La contents above the bulk solubility limit. The films show degenerate semiconducting behavior on both substrates, with the observed room temperature resistivities, Hall mobilities and carrier concentrations of 4.4 mΩcmm \Omega cm, 10.11 cm2V1s1cm^2 V^{-1} s^{-1}, and 1.38 1020cm3\cdot 10^{20} cm^{-3} on SmScO3_3 and 7.8 mΩcmm \Omega cm, 5.8 cm2V1s1cm^2 V^{-1} s^{-1}, and 1.36 1020cm3\cdot 10^{20} cm^{-3} on SrTiO3_3 ruling out any extrinsic contribution from the substrate. The superior electrical properties observed on the SmScO3 substrate are attributed to reduction in dislocation density from the lower lattice mismatch.Comment: 11 pages, 3 figures, supplementary informations 2 figure

    Coupling of ventricular action potential duration and local strain patterns during reverse remodeling in responders and non-responders to cardiac resynchronization therapy

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    BACKGROUND: The high risk of ventricular arrhythmias in heart failure patients remains despite the benefit of cardiac resynchronization therapy (CRT). An electromechanical interaction between regional myocardial strain patterns and the electrophysiological substrate is thought to be important. OBJECTIVE: We investigated the in-vivo relation between left ventricular (LV) activation recovery interval (ARI), as a surrogate measure of activation potential duration (APD), and local myocardial strain patterns in responders and non-responders to CRT. METHODS: ARI were recorded from the left ventricular epicardium in 20 CRT patients 6 weeks and 6 months post implant. Two-dimensional speckle tracking echocardiography was performed at the same time to assess myocardial strains. Patients with ≥15% reduction in end-systolic volume at 6-months were classified as responders. RESULTS: ARI reduced in responders, 263±46ms vs. 246±47ms, p145ms and QRS shortening with biventricular pacing was associated with ARI shortening during CRT. CONCLUSIONS: Changes in ventricular wall mechanics predict local APD lengthening or shortening during CRT. Non-responders have a worsening of myocardial strain and local APD. Baseline QRS >145ms and QRS shortening on biventricular pacing identified patients who exhibited improvement in APD

    Listen to genes : dealing with microarray data in the frequency domain

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    Background: We present a novel and systematic approach to analyze temporal microarray data. The approach includes normalization, clustering and network analysis of genes. Methodology: Genes are normalized using an error model based uniform normalization method aimed at identifying and estimating the sources of variations. The model minimizes the correlation among error terms across replicates. The normalized gene expressions are then clustered in terms of their power spectrum density. The method of complex Granger causality is introduced to reveal interactions between sets of genes. Complex Granger causality along with partial Granger causality is applied in both time and frequency domains to selected as well as all the genes to reveal the interesting networks of interactions. The approach is successfully applied to Arabidopsis leaf microarray data generated from 31,000 genes observed over 22 time points over 22 days. Three circuits: a circadian gene circuit, an ethylene circuit and a new global circuit showing a hierarchical structure to determine the initiators of leaf senescence are analyzed in detail. Conclusions: We use a totally data-driven approach to form biological hypothesis. Clustering using the power-spectrum analysis helps us identify genes of potential interest. Their dynamics can be captured accurately in the time and frequency domain using the methods of complex and partial Granger causality. With the rise in availability of temporal microarray data, such methods can be useful tools in uncovering the hidden biological interactions. We show our method in a step by step manner with help of toy models as well as a real biological dataset. We also analyse three distinct gene circuits of potential interest to Arabidopsis researchers

    Roaring high and low: composition and possible functions of the Iberian stag's vocal repertoire

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    We provide a detailed description of the rutting vocalisations of free-ranging male Iberian deer (Cervus elaphus hispanicus, Hilzheimer 1909), a geographically isolated and morphologically differentiated subspecies of red deer Cervus elaphus. We combine spectrographic examinations, spectral analyses and automated classifications to identify different call types, and compare the composition of the vocal repertoire with that of other red deer subspecies. Iberian stags give bouts of roars (and more rarely, short series of barks) that are typically composed of two different types of calls. Long Common Roars are mostly given at the beginning or at the end of the bout, and are characterised by a high fundamental frequency (F0) resulting in poorly defined formant frequencies but a relatively high amplitude. In contrast, Short Common Roars are typically given in the middle or at the end of the bout, and are characterised by a lower F0 resulting in relatively well defined vocal tract resonances, but low amplitude. While we did not identify entirely Harsh Roars (as described in the Scottish red deer subspecies (Cervus elaphus scoticus), a small percentage of Long Common Roars contained segments of deterministic chaos. We suggest that the evolution of two clearly distinct types of Common Roars may reflect divergent selection pressures favouring either vocal efficiency in high pitched roars or the communication of body size in low-pitched, high spectral density roars highlighting vocal tract resonances. The clear divergence of the Iberian red deer vocal repertoire from those of other documented European red deer populations reinforces the status of this geographical variant as a distinct subspecies

    Coupling models of cattle and farms with models of badgers for predicting the dynamics of bovine tuberculosis (TB)

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    Bovine TB is a major problem for the agricultural industry in several countries. TB can be contracted and spread by species other than cattle and this can cause a problem for disease control. In the UK and Ireland, badgers are a recognised reservoir of infection and there has been substantial discussion about potential control strategies. We present a coupling of individual based models of bovine TB in badgers and cattle, which aims to capture the key details of the natural history of the disease and of both species at approximately county scale. The model is spatially explicit it follows a very large number of cattle and badgers on a different grid size for each species and includes also winter housing. We show that the model can replicate the reported dynamics of both cattle and badger populations as well as the increasing prevalence of the disease in cattle. Parameter space used as input in simulations was swept out using Latin hypercube sampling and sensitivity analysis to model outputs was conducted using mixed effect models. By exploring a large and computationally intensive parameter space we show that of the available control strategies it is the frequency of TB testing and whether or not winter housing is practised that have the most significant effects on the number of infected cattle, with the effect of winter housing becoming stronger as farm size increases. Whether badgers were culled or not explained about 5%, while the accuracy of the test employed to detect infected cattle explained less than 3% of the variance in the number of infected cattle

    Potential conservation of circadian clock proteins in the phylum Nematoda as revealed by bioinformatic searches

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    Although several circadian rhythms have been described in C. elegans, its molecular clock remains elusive. In this work we employed a novel bioinformatic approach, applying probabilistic methodologies, to search for circadian clock proteins of several of the best studied circadian model organisms of different taxa (Mus musculus, Drosophila melanogaster, Neurospora crassa, Arabidopsis thaliana and Synechoccocus elongatus) in the proteomes of C. elegans and other members of the phylum Nematoda. With this approach we found that the Nematoda contain proteins most related to the core and accessory proteins of the insect and mammalian clocks, which provide new insights into the nematode clock and the evolution of the circadian system.Fil: Romanowski, Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; ArgentinaFil: Garavaglia, Matías Javier. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Ing.genética y Biolog.molecular y Celular. Area Virus de Insectos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Goya, María Eugenia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ghiringhelli, Pablo Daniel. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Ing.genética y Biolog.molecular y Celular. Area Virus de Insectos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Golombek, Diego Andres. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Temporal Processing of Vibratory Communication Signals at the Level of Ascending Interneurons in Nezara viridula (Hemiptera: Pentatomidae)

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    During mating, males and females of N. viridula (Heteroptera: Pentatomidae) produce sex- and species-specific calling and courtship substrate-borne vibratory signals, grouped into songs. Recognition and localization of these signals are fundamental for successful mating. The recognition is mainly based on the temporal pattern, i.e. the amplitude modulation, while the frequency spectrum of the signals usually only plays a minor role. We examined the temporal selectivity for vibratory signals in four types of ascending vibratory interneurons in N. viridula. Using intracellular recording and labelling technique, we analyzed the neurons' responses to 30 pulse duration/interval duration (PD/ID) combinations. Two response arrays were created for each neuron type, showing the intensity of the responses either as time-averaged spike counts or as peak instantaneous spike rates. The mean spike rate response arrays showed preference of the neurons for short PDs (below 600 ms) and no selectivity towards interval duration; while the peak spike rate response arrays exhibited either short PD/long ID selectivity or no selectivity at all. The long PD/short ID combinations elicited the weakest responses in all neurons tested. No response arrays showed the receiver preference for either constant period or duty cycle. The vibratory song pattern selectivity matched the PD of N. viridula male vibratory signals, thus pointing to temporal filtering for the conspecific vibratory signals already at level of the ascending interneurons. In some neurons the responses elicited by the vibratory stimuli were followed by distinct, regular oscillations of the membrane potential. The distance between the oscillation peaks matched the temporal structure of the male calling song, indicating a possible resonance based mechanism for signal recognition
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