Search results for "Ion density"
showing 10 items of 229 documents
Populated Places and Conspicuous Consumption: High Population Density Cues Predict Consumers’ Luxury-Linked Brand Attitudes
2021
Population density has been identified as an ecological factor with considerable behavioral implications. The present research aimed to examine whether the mere perception of more (vs. less) populated places can change consumers’ luxury-linked brand attitudes. To this end, we experimentally manipulated consumers’ perceptions of population density using pictorial exposure to high (vs. low) population density cues. The results revealed a significant interaction between manipulated population density and perceived brand luxury on brand attitudes. Specifically, exposure to high rather than low population density cues resulted in more positive (negative) attitudes toward brands deemed to be more…
Density-dependent regulation of natural and laboratory rotifer populations
2001
Density-dependent regulation of abundance is fundamentally important in the dynamics of most animal populations. Density effects, however, have rarely been quantified in natural populations, so population models typically have a large uncertainty in their predictions. We used models generated from time series analysis to explore the form and strength of density-dependence in several natural rotifer populations. Population growth rate (r) decreased linearly or non-linearly with increased population density, depending on the rotifer species. Density effects in natural populations reduced r to 0 at densities of 1–101−1 for 8 of the 9 rotifer species investigated. The sensitivities of these spe…
GW170817: Measurements of Neutron Star Radii and Equation of State
2018
On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were neutron stars that are described by the same equation…
Stark level crossing and optical-rf double resonance in NaK D 1 Π
1997
We report here (Lambda) -doubling splitting and permanent electric dipole moment d p measurements for a number of vibrotational levels of NaK D 1 II state. Two different methods, which are not Doppler limited, were used. Stark effect induced level crossing was registered as fluorescence polarization changes with external electric field, which allowed us to obtain, from one fit, the values of electric dipole moment and (Lambda) -doubling splitting (Delta) ef between e, f substates of an individual rotational state. Another method consisted in obtaining the ratio (Delta) ef /d p from electric field dependence of the intensity of forbidden line appeared in fluorescence as a result of e- f Star…
Paleoclimate and bubonic plague: a forewarning of future risk?
2010
Background Human cases of plague (Yersinia pestis) infection originate, ultimately, in the bacterium's wildlife host populations. The epidemiological dynamics of the wildlife reservoir therefore determine the abundance, distribution and evolution of the pathogen, which in turn shape the frequency, distribution and virulence of human cases. Earlier studies have shown clear evidence of climatic forcing on contemporary plague abundance in rodents and humans. Results We find that high-resolution palaeoclimatic indices correlate with plague prevalence and population density in a major plague host species, the great gerbil (Rhombomys opimus), over 1949-1995. Climate-driven models trained on these…
Nested assemblages resulting from host size variation: the case of endoparasite communities in fish hosts
2001
Nested species subsets are a common pattern in many types of communities found in insular or fragmented habitats. Nestedness occurs in some communities of ectoparasites of fish, as does the exact opposite departure from random assembly, anti-nestedness. Here, we looked for nested and anti-nested patterns in the species composition of communities of internal parasites of 23 fish populations from two localities in Finland. We also compared various community parameters of nested and anti-nested assemblages of parasites, and determined whether nestedness may result simply from a size-related accumulation of parasite species by feeding fish hosts. Nested parasite communities were characterised b…
Diel vertical movements of zooplankton in lake La Cruz (Cuenca, Spain)
2000
The study of diel vertical movements of zooplankton in a small meromictic karstic lake (lake La Cruz), presenting highly stratified waters, was performed using two different methodologies: (i) samples were taken along the vertical profile and were compared at different hours in a diel cycle; (ii) some plankton traps were located at different depths, covering different periods of time, to catch organisms going upwards and downwards. The main subject of this study has been the vertical movements affecting rotifers since they were dominant in the zooplankton of this lake, but we have also included the results obtained for other zooplankton groups. The results indicate an almost general movemen…
Forest Fragmentation Increases Nest Predation in the Eurasian Treecreeper
2004
We used long-term breeding data to monitor the influences of fragmentation and habitat composi- tion at different spatial scales on the reproductive success of Eurasian Treecreepers (Certhia familiaris) breeding in nest boxes. We collected data from the same forest patches (2.7-65.1 ha in size) during seven breeding sea- sons. Nest predation varied considerably over the years and was the primary cause of nesting failure (mean annual rate of 21.6 ± 12.8%). Nest predation explained most of the variation in fledgling production during the study period. Landscape-level fragmentation (radius of 500 m from territory center) affected nest predation more than did fragmentation on the territory scal…
Norm-Based Trade Union Membership: Evidence for Germany
2004
AbstractIn the absence of closed shops and discriminatory wage policies, union membership can be explained by the existence of social norms.We describe a model, incorporating institutional features of the German labour market, which explicitly allows for social custom effects in the determination of union membership. Using panel data for Germany, we find evidence for according effects which restrict freeriding. The impact of social norms tends to increase with net union density. Hence, observed reductions in the demand for union membership can weaken the impact of a norm and accentuate the free-rider problem.
Molecular characterisation of Galba truncatula, Lymnaea neotropica and L. schirazensis from Cajamarca, Peru and their potential role in transmission …
2012
Abstract Background Human and animal fascioliasis is emerging in many world regions, among which Andean countries constitute the largest regional hot spot and Peru the country presenting more human endemic areas. A survey was undertaken on the lymnaeid snails inhabiting the hyperendemic area of Cajamarca, where human prevalences are the highest known among the areas presenting a "valley transmission pattern", to establish which species are present, genetically characterise their populations by comparison with other human endemic areas, and discuss which ones have transmission capacity and their potential implications with human and animal infection. Methods Therefore, ribosomal DNA ITS-2 an…