104 research outputs found
The diverse nature of island isolation and its effect on land bridge insular faunas
Aim:
Isolation is a key factor in island biology. It is usually defined as the distance to the geographically nearest mainland, but many other definitions exist. We explored how testing different isolation indices affects the inference of impacts of isolation on faunal characteristics. We focused on land bridge islands and compared the relationships of many spatial and temporal (i.e., through time) isolation indices with community‐, population‐ and individual‐level characteristics (species richness, population density and body size, respectively).
Location:
Aegean Sea islands, Greece.
Time period:
Current.
Taxon:
Many animal taxa.
Methods:
We estimated 21 isolation indices for 205 islands and recorded species richness data for 15 taxa (invertebrates and vertebrates). We obtained body size data for seven lizard species and population density data for three. We explored how well indices predict each characteristic, in each taxon, by conducting a series of ordinary least squares regressions (controlling for island area when needed) and a meta‐analysis.
Results:
Isolation was significantly (and negatively) associated with species richness in 10 of 15 taxa. It was significantly (and positively) associated with body size in only one of seven species and was not associated with population density. The effect of isolation on species richness was much weaker than that of island area, regardless of the index tested. Spatial indices generally out‐performed temporal indices, and indices directly related to the mainland out‐performed those related mainly to neighbouring islands. No index was universally superior to others, including the distance to the geographically nearest mainland.
Main conclusions:
The choice of index can alter our perception of the impacts of isolation on biological patterns. The nearly automatic, ubiquitous use of distance to the geographically nearest mainland misrepresents the complexity of the effects of isolation. We recommend the simultaneous testing of several indices that represent different aspects of isolation, in order to produce more constructive and thorough investigations and avoid imprecise inference
PopBERT. Detecting populism and its host ideologies in the German Bundestag
The rise of populism concerns many political scientists and practitioners,
yet the detection of its underlying language remains fragmentary. This paper
aims to provide a reliable, valid, and scalable approach to measure populist
stances. For that purpose, we created an annotated dataset based on
parliamentary speeches of the German Bundestag (2013 to 2021). Following the
ideational definition of populism, we label moralizing references to the
virtuous people or the corrupt elite as core dimensions of populist language.
To identify, in addition, how the thin ideology of populism is thickened, we
annotate how populist statements are attached to left-wing or right-wing host
ideologies. We then train a transformer-based model (PopBERT) as a multilabel
classifier to detect and quantify each dimension. A battery of validation
checks reveals that the model has a strong predictive accuracy, provides high
qualitative face validity, matches party rankings of expert surveys, and
detects out-of-sample text snippets correctly. PopBERT enables dynamic analyses
of how German-speaking politicians and parties use populist language as a
strategic device. Furthermore, the annotator-level data may also be applied in
cross-domain applications or to develop related classifiers
A comparison of Irish set dancing and exercises for people with Parkinson’s disease: A phase II feasibility study
Imaginal Discs – A New Source of Chromosomes for Genome Mapping of the Yellow Fever Mosquito Aedes aegypti
Dengue fever is an emerging health threat to as much as half of the human population around the world. No vaccines or drug treatments are currently available. Thus, disease prevention is largely based on efforts to control its major mosquito vector Ae. aegypti. Novel vector control strategies, such as population replacement with pathogen-incompetent transgenic mosquitoes, rely on detailed knowledge of the genome organization for the mosquito. However, the current genome assembly of Ae. aegypti is highly fragmented and requires additional physical mapping onto chromosomes. The absence of readable polytene chromosomes makes genome mapping for this mosquito extremely challenging. In this study, we discovered and investigated a new source of chromosomes useful for the cytogenetic analysis in Ae. aegypti – mitotic chromosomes from imaginal discs of 4th instar larvae. Using natural banding patterns of these chromosomes, we developed a new band-based approach for physical mapping of DNA probes to the precise chromosomal positions. Further application of this approach for genome mapping will greatly enhance the utility of the existing draft genome sequence assembly for Ae. aegypti and thereby facilitate application of advanced genome technologies for investigating and developing novel genetic control strategies for dengue transmission
Partial baroreceptor dysfunction and low plasma nitric oxide bioavailability as determinants of salt-sensitive hypertension: a reverse translational rat study
An improved strategy for evaluating the extent of chronic arterial baroreceptor denervation in conscious rats
Endoleak and Pseudoaneurysm Formation in the Setting of Stent Graft Infection Following Endovascular Uretero-Arterial Fistula Repair: The Dreaded Complication
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Studies of the role of molten materials in interactions with UO/sub 2/ and graphite. [GCFR type reactors]
Graphite, which is being considered as a lower reactor shield in gas-cooled fast reactors, would be contacted by core debris during a core disruptive accident. Information on the interaction of graphite, UO/sub 2/, and stainless steel is needed in assessing the safety of the GCFR. In an ongoing study of the interaction of graphite, UO/sub 2/, and stainless steel, the effects of the steel components have been investigated by electron microprobe scans, x-ray diffraction, and reaction-rate measurements. Experiments to study the role of the reaction product, FeUC/sub 2/, in the interaction suggested that FeUC/sub 2/ promotes the interaction by acting as a carrier to bring graphite to the reaction site. Additional experiments using pyrolytic graphite show that while the reaction rate is decreased at 2400 K, at higher temperatures the rate is similar to that using other grades of graphite
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