245 research outputs found

    Complex community responses underpin biodiversity change following invasion

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    How do invasive species change native biodiversity? One reason why this long-standing question remains challenging to answer could be because the main focus of the invasion literature has been on shifts in species richness (a measure of α-diversity). As the underlying components of community structure—intraspecific aggregation, interspecific density and the species abundance distribution (SAD)—are potentially impacted in different ways during invasion, trends in species richness provide only limited insight into the mechanisms leading to biodiversity change. In addition, these impacts can be manifested in distinct ways at different spatial scales. Here we take advantage of the new Measurement of Biodiversity (MoB) framework to reanalyse data collected in an invasion front in the Brazilian Cerrado biodiversity hotspot. We show that, by using the MoB multi-scale approach, we are able to link reductions in species richness in invaded sites to restructuring in the SAD. This restructuring takes the form of lower evenness in sites invaded by pines relative to sites without pines. Shifts in aggregation also occur. There is a clear signature of spatial scale in biodiversity change linked to the presence of an invasive species. These results demonstrate how the MoB approach can play an important role in helping invasion ecologists, field biologists and conservation managers move towards a more mechanistic approach to detecting and interpreting changes in ecological systems following invasion

    Characterization of polyoxometalate I as an inhibitor of RNA-dependent RNA polymerase of Foot and Mouth Disease virus [abstract]

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    Abstract only availableFoot and Mouth Disease (FMD) is a highly contagious disease that affects a variety of domesticated cloven-hoofed animals including cattle, swine, sheep and goats, as well as several wild animal species. FMD outbreaks are currently controlled with mass-extermination of livestock. The financial cost of potential outbreaks would be immense. This disease is caused by foot-and-mouth disease virus (FMDV), a non-enveloped, single-stranded, positive-sense RNA virus. The purpose of our investigation is to identify chemicals that interfere with the replication of FMDV. As part of this effort we have identified a polyoxometalate inhibitor (polyoxometalate I). We have cloned, expressed and purified FMDV RdRp. We use steady-state kinetic experiments and polymerization assays to characterize the inhibitory activity of the polyoxometalate I, determining the precise inhibitory potential and the mechanism of inhibition. Preliminary results show that polyoxometalate I inhibits the FMDV RdRp surprisingly efficiently with an IC50 of 0.5uM. Current experiments are focusing on a detailed kinetic characterization of the mechanism of action for this inhibitor. This research may provide insights that lead to new treatment options to prevent the further spread of FMD to unaffected animals.USD

    NiII^{II}36_{36}-Containing 54-Tungsto-6-Silicate: Synthesis, Structure, Magnetic and Electrochemical Studies

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    The 36-NiII^{II}-containing 54-tungsto-6-silicate, [Ni36_{36}(OH)18_{18}(H2_{2}O)36_{36}(SiW9_{9}O34_{34})6_{6}]6−^{6-} (Ni36_{36}) was synthesized by a simple one-pot reaction of the Ni2_{2}-pivalate complex [Ni2_{2}(ÎŒ-OH2_{2})(O2_{2}CCMe3_{3})4_{4}(HO2_{2}CCMe3_{3})4_{4}] with the trilacunary [SiW9_{9}O34_{34}]10−^{10-} polyanion precursor in water and structurally characterized by a multitude of physicochemical techniques including single-crystal XRD, FTIR, TGA, elemental analysis, magnetic and electrochemical studies. Polyanion Ni36_{36} comprises six equivalent {NiII^{II}36_{36}SiW9_{9}} units which are linked by Ni−O−W bridges forming a macrocyclic assembly. Magnetic studies demonstrate that the {Ni6_{6}} building blocks in Ni36_{36} remain magnetically intact while forming a hexagonal ring with antiferromagnetic exchange interactions between adjacent {Ni6} units. Electrochemical studies indicate that the first reduction is reversible and associated with the WVI/V couple, whereas the second reduction is irreversible attributed to the NiII/0^{II/0} couple

    Novel Echocardiographic Biomarkers in the Management of Atrial Fibrillation

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    Purpose of Review: Atrial fibrillation (AF) is the most common arrhythmia in adults. The number of patients with AF is anticipated to increase annually, mainly due to the aging population alongside improved arrhythmia detection. AF is associated with a significantly elevated risk of hospitalization, stroke, thromboembolism, heart failure, and all-cause mortality. Echocardiography is one of the key components of routine assessment and management of AF. Therefore, the aim of this review is to briefly summarize current knowledge on “novel” echocardiographic parameters that may be of value in the management of AF patients. Recent Findings: Novel echocardiographic biomarkers and their clinical application related to the management of AF have been taken into consideration. Both standard parameters such as atrial size and volume but also novels like atrial strain and tissue Doppler techniques have been analyzed. Summary: A number of novel echocardiographic parameters have been proven to enable early detection of left atrial dysfunction along with increased diagnosis accuracy. This concerns particularly experienced echocardiographers. Hence, these techniques might improve the prediction of stroke and thromboembolic events among AF patients and need to be further developed and disseminated. Nonetheless, even the standard imaging parameters could be of significant value and should not be discontinued in everyday clinical practice. © 2019, The Author(s)
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