26 research outputs found
STOCHASTIC DYNAMICS OF LARGE-SCALE INFLATION IN DE~SITTER SPACE
In this paper we derive exact quantum Langevin equations for stochastic
dynamics of large-scale inflation in de~Sitter space. These quantum Langevin
equations are the equivalent of the Wigner equation and are described by a
system of stochastic differential equations. We present a formula for the
calculation of the expectation value of a quantum operator whose Weyl symbol is
a function of the large-scale inflation scalar field and its time derivative.
The unique solution is obtained for the Cauchy problem for the Wigner equation
for large-scale inflation. The stationary solution for the Wigner equation is
found for an arbitrary potential. It is shown that the large-scale inflation
scalar field in de Sitter space behaves as a quantum one-dimensional
dissipative system, which supports the earlier results. But the analogy with a
one-dimensional model of the quantum linearly damped anharmonic oscillator is
not complete: the difference arises from the new time dependent commutation
relation for the large-scale field and its time derivative. It is found that,
for the large-scale inflation scalar field the large time asymptotics is equal
to the `classical limit'. For the large time limit the quantum Langevin
equations are just the classical stochastic Langevin equations (only the
stationary state is defined by the quantum field theory).Comment: 21 pages RevTex preprint styl
Environmentally Realistic Exposure to the Herbicide Atrazine Alters Some Sexually Selected Traits in Male Guppies
Male mating signals, including ornaments and courtship displays, and other sexually selected traits, like male-male aggression, are largely controlled by sex hormones. Environmental pollutants, notably endocrine disrupting compounds, can interfere with the proper functioning of hormones, thereby impacting the expression of hormonally regulated traits. Atrazine, one of the most widely used herbicides, can alter sex hormone levels in exposed animals. I tested the effects of environmentally relevant atrazine exposures on mating signals and behaviors in male guppies, a sexually dimorphic freshwater fish. Prolonged atrazine exposure reduced the expression of two honest signals: the area of orange spots (ornaments) and the number of courtship displays performed. Atrazine exposure also reduced aggression towards competing males in the context of mate competition. In the wild, exposure levels vary among individuals because of differential distribution of the pollutants across habitats; hence, differently impacted males often compete for the same mates. Disrupted mating signals can reduce reproductive success as females avoid mating with perceptibly suboptimal males. Less aggressive males are at a competitive disadvantage and lose access to females. This study highlights the effects of atrazine on ecologically relevant mating signals and behaviors in exposed wildlife. Altered reproductive traits have important implications for population dynamics, evolutionary patterns, and conservation of wildlife species
Factors affecting perceptions in transport – A deep dive into the motorbike ban in Hanoi, Vietnam
The dependence on motorbikes has contributed to traffic problems in Hanoi, Vietnam. Policymakers have considered a controversial ban on nonelectric motorbikes in parts of the city in an effort to reduce congestion and pollution. However, understanding of individual perceptions on critical transport policies, such as this potential ban is lacking, especially in the Global South, with implications for evidence-based policy making. This paper presents the results of some exploratory data analysis and a machine learning application using a travel survey recently conducted in Hanoi. It aims to understand how residents perceive a potential motorbike ban, their perceptions of different mobility modes, as well as their future plans for mobility if motorbikes are banned. This data-driven analysis of policy scenarios shows that awareness of the potential ban, distance to public transport, and individual transport modal choice determine the acceptability of the proposed motorbike ban and its likely success. It also shows that policymakers in Hanoi should also consider citizens’ plans for future vehicle ownership, as the analysis results suggest that cars are likely to replace motorbikes if the ban is implemented
Institutional logics and curriculum decision making: enacting the Australian Curriculum English and NAPLAN literacy
Integrating biodiversity, remote sensing, and auxiliary information for the study of ecosystem functioning and conservation at large spatial scales
Assessing patterns and processes of plant functional, taxonomic, genetic, and structural biodiversity at large scales is essential across many disciplines, including ecosystem management, agriculture, ecosystem risk and service assessment, conservation science, and forestry. In situ data housed in databases necessary to perform such assessments over large parts of the world are growing steadily. Integrating these in situ data with remote sensing (RS) products helps not only to improve data completeness and quality but also to account for limitations and uncertainties associated with each data product. Here, we outline how auxiliary environmental and socioeconomic data might be integrated with biodiversity and RS data to expand our knowledge about ecosystem functioning and inform the conservation of biodiversity. We discuss concepts, data, and methods necessary to assess plant species and ecosystem properties across scales of space and time and provide a critical discussion of outstanding issues
Implementation of day of surgery admission for rectal cancer surgery in Ireland following a national centralisation programme
Genetic relationships among NE Turkish Lilium L. (Liliaceae) species based on Random Amplified Polymorphic DNA (RAPD) analysis
Random amplified polymorphic DNA (RAPD) fingerprinting was used to study species boundaries in six closely related NE Turkish Lilium (Liliaceae) taxa of the section Liriotypus. The investigated taxa were L. ciliatum, L. akkusianum, L. ponticum, L. kesselringianum, L. armenum, and L. szovitsianum. Of the 108 primers screened, 11 provided polymorphic and reproducible bands. A total of 93 polymorphic bands were scored for 122 individuals from 18 populations of the six Lilium taxa and principle coordinate analysis and neighbour-joining cluster analysis based on these RAPD profiles were performed. The results demonstrate a clear distinction between the two species L. ciliatum and L. akkusianum, and the other four species. While populations of the two species groups are found to be allopatrically distributed, the two species groups overlap in their geographical ranges. Analysis of molecular variance (AMOVA) indicated that nearly half of the total molecular variance is found within the individual populations and that the molecular variance among species is as high as the variance within the individual species, indicating that genetic differentiation of the species is rather weak