Search results for "interactions."
showing 10 items of 1865 documents
Arbuscular mycorrhizal fungi influence host infection during epidemics in a wild plant pathosystem
2022
SummaryWhile pathogenic and mutualistic microbes are ubiquitous across ecosystems and often co-occur within hosts, how they interact to determine patterns of disease in genetically diverse wild populations is unknown.To test whether microbial mutualists provide protection against pathogens, and whether this varies among host genotypes, we conducted a field experiment in three naturally-occurring epidemics of a fungal pathogen, Podosphaera plantaginis, infecting a host plant, Plantago lanceolata, in the Åland Islands, Finland. In each population, we collected epidemiological data on experimental plants from six allopatric populations that had been inoculated with a mixture of mutualistic arb…
Are Sick Individuals Weak Competitors? Competitive Ability of Snails Parasitized by a Gigantism-Inducing Trematode
2013
Parasitized individuals are often expected to be poor competitors because they are weakened by infections. Many trematode species, however, although extensively exploiting their mollusc hosts, also induce gigantism (increased host size) by diverting host resources towards growth instead of reproduction. In such systems, alternatively to reduced competitive ability due to negative effects of parasitism on host performance, larger size could allow more efficient resource acquisition and thus increase the relative competitive ability of host individuals. We addressed this hypothesis by testing the effect of a trematode parasite Diplostomum pseudospathaceum on the competitive ability of its sna…
Effects of environment and genotype on dispersal differ across departure, transfer and settlement in a butterfly metapopulation
2022
Active dispersal is driven by extrinsic and intrinsic factors at the three stages of departure, transfer and settlement. Most empirical studies capture only one stage of this complex process, and knowledge of how much can be generalized from one stage to another remains unknown. Here we use genetic assignment tests to reconstruct dispersal across 5 years and 232 habitat patches of a Glanville fritillary butterfly ( Melitaea cinxia ) metapopulation. We link individual dispersal events to weather, landscape structure, size and quality of habitat patches, and individual genotype to identify the factors that influence the three stages of dispersal and post-settlement survival. We found that ne…
s-wave charmed baryon resonances from a coupled-channel approach with heavy quark symmetry
2009
We study charmed baryon resonances which are generated dynamically within a unitary meson-baryon coupled channel model that treats the heavy pseudoscalar and vector mesons on equal footing as required by heavy-quark symmetry. It is an extension of recent SU(4) models with t-channel vector meson exchanges to a SU(8) spin-flavor scheme, but differs considerably from the SU(4) approach in how the strong breaking of the flavor symmetry is implemented. Some of our dynamically generated states can be readily assigned to recently observed baryon resonances, while others do not have a straightforward identification and require the compilation of more data as well as an extension of the model to d-w…
Properties of D and D-* mesons in the nuclear medium
2009
We study the properties of D and D-* mesons in nuclear matter within a simultaneous self-consistent coupled-channel unitary approach that implements heavy-quark symmetry. The in-medium solution accounts for Pauli blocking effects and for the D and D-* self-energies in a self-consistent manner. We pay special attention to renormalization of the intermediate propagators in the medium beyond the usual cutoff scheme. We analyze the behavior in the nuclear medium of the rich spectrum of dynamically generated baryonic resonances in the C=1 and S=0 sector and their influence on the self-energy and, hence, the spectral function of D and D-* mesons. The D meson quasiparticle peak mixes with Sigma(c)…
Infracommunity level aggregation in the monogenean communities of crucian carp (Carassius carassius).
2005
Aggregation is one of the distinctive features in parasite-host relationships, which has generally been studied at the level of host communities. Parasite aggregation at the infracommunity level may nevertheless be important for intraspecific interactions such as parasite mating success and opportunities for cross-fertilization. In the present paper, we studied the infracommunity aggregation of 3 highly abundantDactylogyrus(Monogenea) species occurring on the gills of crucian carp (Carassius carassius). In line with the previous work on monogenean communities, we observed no competition between the species. At the species level, parasites were distributed unevenly on the gills showing aggre…
Genomic determinants of speciation and spread of the Mycobacterium tuberculosis complex
2019
14 páginas, 6 figuras
Induced Dipoles and Possible Modulation of Wireless Effects in Implanted Electrodes. Effects of Implanting Insulated Electrodes on an Animal Test to …
2021
There is evidence that Deep Brain Stimulation (DBS) produces health benefits in patients even before initiating stimulation. Furthermore, DBS electrode insertion in rat infralimbic cortex (ILC) provokes antidepressant-like effects before stimulation, due to local inflammation and astrogliosis. Consequently, a significant effect of implanting electrodes is suspected. External fields, similar in magnitude to the brain’s endogenous fields, induce electric dipoles in conducting materials, in turn influencing neural cell growth through wireless effects. To elucidate if such dipoles influence depressive-like behavior, without external stimulation, the comparative effect of conducting and insulate…
[Pharmacological treatment of depression after acute myocardial infarction].
2005
Depressed mood and other depressive symptoms frequently appear after acute myocardial infarction and it is known how these patients have an increased risk for morbidity and mortality compared to patients without depression. Many risk factors promote the development of clinical depression in patients with recent myocardial infarction. Although a large number of studies underline the negative prognostic impact of depression on the infarcted patient, only rarely depressed patients are appropriately diagnosed and treated. Furthermore it should be borne in mind that the use of psychotropics in medically ill patients requires attention. These compounds, in fact, may interact with the disease caus…
Development of stir bar sorptive-dispersive microextraction mediated by magnetic nanoparticles and its analytical application to the determination of…
2014
A novel microextraction technique combining the principles of stir bar sorptive extraction (SBSE) and dispersive micro-solid phase extraction (DμSPE) is presented. The main feature of the method is the use of a neodymium-core stirring bar physically coated with a hydrophobic magnetic nanosorbent. Depending on stirring speed, the magnetic sorbent either acts as a coating material to the stir bar, thus affording extraction alike SBSE, or as a dispersed nanosorbent medium for the collection and extraction of the target analytes, in close analogy to DμSPE. Once the stirring process is finished, the strong magnetic field of the stir bar prevails again and rapidly retrieves the dispersed MNPs. Al…