Further characterization of the long-run population distribution of a deleterious gene

1980 ◽  
Vol 18 (1) ◽  
pp. 31-43 ◽  
Author(s):  
K. Lange ◽  
K. Gladstien
2014 ◽  
Vol 6 (2) ◽  
pp. 71-107 ◽  
Author(s):  
Fernando Alvarez ◽  
Francesco Lippi

We present a monetary model with segmented asset markets that implies a persistent fall in interest rates after a once-and-for-all increase in liquidity. The gradual propagation mechanism produced by our model is novel in the literature. We provide an analytical characterization of this mechanism, showing that the magnitude of the liquidity effect on impact, and its persistence, depend on the ratio of two parameters: the long-run interest rate elasticity of money demand and the intertemporal substitution elasticity. The model simultaneously explains the short-run “instability” of money demand estimates as well as the stability of long-run interest-elastic money demand. (JEL E13, E31, E41, E43, E52, E62)


2000 ◽  
Vol 83 (3) ◽  
pp. 287-293 ◽  
Author(s):  
Clifton Gay

There have been many attempts to characterize day-to-day variation in nutrient intake. This variation has a fixed component, associated with particular days of the week, and a random component. Both components were studied for a range of nutrients, using 4 d weighed diary data from a large, nationally representative survey of people aged 65 years or over. Since day-to-day variation may distort the characterization of the population distribution of habitual nutrient intakes, especially when diets are studied over only a small number of days, a statistical method was developed to correct for this distortion. Results suggested that population distributions of habitual nutrient intake could be accurately constructed from 4 d weighed diary data and that the method might be successfully applied to studies based on as little as 2 d of observation. The method is particularly valuable for correcting estimates of extreme nutrient intakes for biases induced by uneven representation of days of the week and by within-person variation.


2008 ◽  
Vol 74 (21) ◽  
pp. 6709-6719 ◽  
Author(s):  
Annette R. Rowe ◽  
Brendan J. Lazar ◽  
Robert M. Morris ◽  
Ruth E. Richardson

ABSTRACT This study sought to characterize bacterial and archaeal populations in a perchloroethene- and butyrate-fed enrichment culture containing hydrogen-consuming “Dehalococcoides ethenogenes” strain 195 and a Methanospirillum hungatei strain. Phylogenetic characterization of this microbial community was done via 16S rRNA gene clone library and gradient gel electrophoresis analyses. Fluorescence in situ hybridization was used to quantify populations of “Dehalococcoides” and Archaea and to examine the colocalization of these two groups within culture bioflocs. A technique for enrichment of planktonic and biofloc-associated biomass was developed and used to assess differences in population distribution and gene expression patterns following provision of substrate. On a per-milliliter-of-culture basis, most D. ethenogenes genes (the hydrogenase gene hupL; the highly expressed gene for an oxidoreductase of unknown function, fdhA; the RNA polymerase subunit gene rpoB; and the 16S rRNA gene) showed no statistical difference in expression between planktonic and biofloc enrichments at either time point studied (1 to 2 and 6 h postfeeding). Normalization of transcripts to ribosome (16S rRNA) levels supported that planktonic and biofloc-associated D. ethenogenes had similar gene expression profiles, with one notable exception; planktonic D. ethenogenes showed higher expression of tceA relative to biofloc-associated cells at 6 h postfeeding. These trends were compared to those for the hydrogen-consuming methanogen in the culture, M. hungatei. The vast majority of M. hungatei cells, ribosomes (16S rRNA), and transcripts of the hydrogenase gene mvrD and the housekeeping gene rpoE were observed in the biofloc enrichments. This suggests that, unlike the comparable activity of D. ethenogenes from both enrichments, planktonic M. hungatei is responsible for only a small fraction of the hydrogenotrophic methanogenesis in this culture.


Author(s):  
Emanuele Crosato ◽  
Mikhail Prokopenko ◽  
Michael S. Harré

Urban dynamics in large metropolitan areas result from complex interactions across social, economic and political factors, including population distribution, flows of wealth and infrastructure requirements. We develop a Census-calibrated model of urban dynamics for the Greater Sydney and Melbourne areas for 2011 and 2016, highlighting the evolution of population distributions and the housing market structure in these two cities in terms of their mortgage and rent distributions. We show that there is a tendency to homophily between renters and mortgage holders: renters tend to cluster nearer commercial centres, whereas mortgagors tend to populate the outskirts of these centres. We also identify a critical threshold at which the long-term evolution of these two cities will bifurcate between a ‘sprawling’ and a ‘polycentric’ configuration, showing that both cities lie on the polycentric side of the critical point in the long-run. Importantly, there is a divergence of these centric tendencies between the renters and mortgage holders. The polycentric patterns characterizing the mortgagors are focused around commercial centres, and we show that the emergent housing patterns follow the major transport routes through the cities.


2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Jayasri Dutta ◽  
Kislaya Prasad

In a number of evolutionary models the presence of mutations, or random components of choice, serve to refine predictions of long-run behavior. We analyze the effects of mutation rates that vary because of the presence of imitation. A full characterization of long-run outcomes is provided for familiar coordination and congestion games, and also a number of other games not previously considered within the evolutionary framework. Our results are often quite distinct from those in the literature. We apply these tools to a series of economic applications, including market games, where imitation can explain excess volatility of prices, and location games, where it leads to greater uniformity in choices.


Author(s):  
Sascha P. Quanz ◽  
Olivier Absil ◽  
Willy Benz ◽  
Xavier Bonfils ◽  
Jean-Philippe Berger ◽  
...  

AbstractExoplanet science is one of the most thriving fields of modern astrophysics. A major goal is the atmospheric characterization of dozens of small, terrestrial exoplanets in order to search for signatures in their atmospheres that indicate biological activity, assess their ability to provide conditions for life as we know it, and investigate their expected atmospheric diversity. None of the currently adopted projects or missions, from ground or in space, can address these goals. In this White Paper, submitted to ESA in response to the Voyage 2050 Call, we argue that a large space-based mission designed to detect and investigate thermal emission spectra of terrestrial exoplanets in the mid-infrared wavelength range provides unique scientific potential to address these goals and surpasses the capabilities of other approaches. While NASA might be focusing on large missions that aim to detect terrestrial planets in reflected light, ESA has the opportunity to take leadership and spearhead the development of a large mid-infrared exoplanet mission within the scope of the “Voyage 2050” long-term plan establishing Europe at the forefront of exoplanet science for decades to come. Given the ambitious science goals of such a mission, additional international partners might be interested in participating and contributing to a roadmap that, in the long run, leads to a successful implementation. A new, dedicated development program funded by ESA to help reduce development and implementation cost and further push some of the required key technologies would be a first important step in this direction. Ultimately, a large mid-infrared exoplanet imaging mission will be needed to help answer one of humankind’s most fundamental questions: “How unique is our Earth?”


2012 ◽  
Vol 127 (4) ◽  
pp. 1927-1969 ◽  
Author(s):  
Philippe Jehiel ◽  
Larry Samuelson

Abstract We consider a repeated interaction between a long-run player and a sequence of short-run players, in which the long-run player may either be rational or may be a mechanical type who plays the same (possibly mixed) action in every stage game. We depart from the classical model in assuming that the short-run players make inferences by analogical reasoning, meaning that they correctly identify the average strategy of each type of long-run player, but do not recognize how this play varies across histories. Concentrating on 2 × 2 games, we provide a characterization of equilibrium payoffs, establishing a payoff bound for the rational long-run player that can be strictly larger than the familiar “Stackelberg” bound. We also provide a characterization of equilibrium behavior, showing that play begins with either a reputation-building or a reputation-spending stage (depending on parameters), followed by a reputation-manipulation stage.


2012 ◽  
Vol 42 (1) ◽  
pp. 179-189 ◽  
Author(s):  
Rajendra Prasad Khajuria ◽  
Shashi Kant ◽  
Susanna Laaksonen-Craig

Proper characterization of the timber price process plays a vital role in forest management decisions. The process of long-run timber prices and its implications for harvesting decisions are analyzed for a forest in Ontario, Canada. Timber prices are modeled as a mean reverting process with stochastic trend. The Kalman filter is used to estimate the state–space model. The forecasted prices from the model are used in real options analysis to determine the optimal investment time and optimal investment rule. The results provide insight different from that of other specifications used in earlier literature.


2020 ◽  
Vol 17 (169) ◽  
pp. 20200620
Author(s):  
Lim Jue Tao ◽  
Borame Sue Lee Dickens ◽  
Mao Yinan ◽  
Chae Woon Kwak ◽  
Ng Lee Ching ◽  
...  

2020 ◽  
Vol 9 (12) ◽  
pp. 746
Author(s):  
Carles Crosas ◽  
Eulàlia Gómez-Escoda

The research analyzes the image of Barcelona and compares differences in quantity, variety and proximity of some essential services in diverse urban fragments. Focusing on food and health premises as critical universal services, series of maps provide overviews on the intensity of use to which each service is subjected, latent logics of their physical proximity and performance in regular urban fabrics due to the combination of activities and population distribution. The research uses a methodological approach and parameterization of the minimum daily urban mixture to highlight the uniqueness of the case of Barcelona, distinguished by the compactness of the urban fabric and the contiguity of activities, and to describe an extensive characterization of areas that from this perspective can be considered hyper-served or under-served. This investigation aims to contribute to the understanding of the necessity of the urban mixture and to provide clues about the distribution of services and activities.


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