Browsing by Subject "Population growth"

Now showing 1 - 9 of 9

Evolvability Is Inevitable: Increasing Evolvability without the Pressure to Adapt
(Public Library of Science, 2013-04-24) Lehman, Joel; Stanley, Kenneth O.
Why evolvability appears to have increased over evolutionary time is an important unresolved biological question. Unlike most candidate explanations, this paper proposes that increasing evolvability can result without any pressure to adapt. The insight is that if evolvability is heritable, then an unbiased drifting process across genotypes can still create a distribution of phenotypes biased towards evolvability, because evolvable organisms diffuse more quickly through the space of possible phenotypes. Furthermore, because phenotypic divergence often correlates with founding niches, niche founders may on average be more evolvable, which through population growth provides a genotypic bias towards evolvability. Interestingly, the combination of these two mechanisms can lead to increasing evolvability without any pressure to out-compete other organisms, as demonstrated through experiments with a series of simulated models. Thus rather than from pressure to adapt, evolvability may inevitably result from any drift through genotypic space combined with evolution's passive tendency to accumulate niches.
Fraternalism gone awry : the Ku Klux Klan in Houston, 1920-1925
(1984) Ahlfield, Danny Lee; Not available
Housing Affordability in Austin Brings New Attention to Mobile Home Parks
(2017-11) Amaro, Gabriel, PhD
While steady job growth has made Austin a desirable migration destination, the resulting population growth has put a strain on housing availability and affordability. Recently, community organizations and city leaders have turned their attention to mobile home parks as a way to provide low-income households with affordable living opportunities within the city limits. In this brief, the Latino Research Institute examines the role of mobile home parks in housing affordability in the city of Austin, Texas.
Housing Affordability: The Impact of Single-Family Investment Purchases on Neighborhoods in the Latino Crescent
(2019-05) Amaro, Gabriel, PhD
Despite efforts to address housing affordability, the Austin area continues to experience record housing cost increases and the displacement of residents due to these increases. In this brief, the Latino Research Institute examines how cheaper housing stock in the area of Austin known as the Latino crescent may be targeted by real estate investors and how investor attention may foster a cycle of housing cost increases.
Making place
(2013-12) Yun, Jihye; Atkinson, Simon, Ph. D.; Almy, Dean
As cities across the world have grown and continue to grow in many ways and for many reasons, it is anticipated that the growth of population will come from all over the world. In turn, it will influence on our urban environment economically, socially, culturally, and ecologically. Like other cities, London is making a plan -creating 326,000 new homes and 776,000 jobs - to tackle issues of the city. A series of new emerging developments across London will contribute to the changing face of the city. A lot of interventions spreading through the city are focused on the economic forces and to take advantages of real estate of London by projecting offices, apartment which is mostly market-housing, and hotels. They swept away existing contexts and replaced with higher density buildings obtaining large profits, building high rise, filling gaps between buildings with gated car parks on the ground floors, and building over open spaces. Ground floors remain blind, and tall office blocks make the overshadowed open square inhospitable and wind turbulence. Most initiatives do not seem to contribute to urban life, but may possibly become the slums of tomorrow. Now, it is time to think about how to make sense of an environment which is safe, pleasant and healthy with a sense of identity, and how to contribute to neighborhoods, visitors and new comers. In dense inner city area, since place is an invitation where neighborhood meets city, urban design must meet needs of commuters, visitors, travelers, and residents equally by combining place, amenity, and movement. Therefore, this study is to investigate ‘How city’s agenda combine with, and support local neighborhood needs’, and to redefine the quality of city life through qualities of comfort, accessibility, amenity, education, experience, and nature.
The Many Faces of Fear: Comparing the Pathways and Impacts of Nonconsumptive Predator Effects on Prey Populations
(Public Library of Science, 2008-06-18) Preisser, Evan L.; Bolnick, Daniel I.
Background -- Most ecological models assume that predator and prey populations interact solely through consumption: predators reduce prey densities by killing and consuming individual prey. However, predators can also reduce prey densities by forcing prey to adopt costly defensive strategies. Methodology/Principal Findings -- We build on a simple Lotka-Volterra predator-prey model to provide a heuristic tool for distinguishing between the demographic effects of consumption (consumptive effects) and of anti-predator defenses (nonconsumptive effects), and for distinguishing among the multiple mechanisms by which anti-predator defenses might reduce prey population growth rates. We illustrate these alternative pathways for nonconsumptive effects with selected empirical examples, and use a meta-analysis of published literature to estimate the mean effect size of each pathway. Overall, predation risk tends to have a much larger impact on prey foraging behavior than measures of growth, survivorship, or fecundity. Conclusions/Significance -- While our model provides a concise framework for understanding the many potential NCE pathways and their relationships to each other, our results confirm empirical research showing that prey are able to partially compensate for changes in energy income, mitigating the fitness effects of defensive changes in time budgets. Distinguishing the many facets of nonconsumptive effects raises some novel questions, and will help guide both empirical and theoretical studies of how predation risk affects prey dynamics.
Small lot amnesty tool : evaluating potential population growth benefits and costs in Austin, Texas
(2016-05) Garner, Brianna; Paterson, Robert G.; Mueller, Elizabeth
This study examines the Small Lot Amnesty tool, an infill tool option for single-family neighborhoods in Austin, Texas. After the tool’s misuse and a heated public discussion, City Council chose to close the developer loophole that many argued did not meet the tool’s original intent. The study quantifies potential population growth benefits and costs if the City Council voted the other way, allowing the tool to disaggregate small lots and build multiple homes on what was once only one house. The findings reveal many population growth benefits, such as increased children enrollment into the local school system, but also expose the challenges of such growth, including increased water runoff due to increased impervious cover. Recommendations are made for the City of Austin and City Council to consider, including a public dialogue and outreach participatory program to gather citizen’s input, future research opportunities to better understand the tool’s potential and issues, and reducing the minimum lot size standards for Single-Family development in Austin.
Urban growth in Central Texas : soils and single-family home development
(2011-08) Fasnacht, Steven Benjamin; Moore, Steven A., 1945-; Dooling, Sarah
This study investigates the potential impacts on soils from development practices associated with new single-family residential home construction in the extra territorial jurisdiction (ETJ) of Pflugerville, Texas. My research question is: Are regulations that directly focus on soil conservation advisable within Pflugerville’s ETJ, and what areas of development ought to be primarily targeted by these regulations in order to better ensure the long-term stability of soil health and the minimization of soil loss? The rationale for this question is based on the city’s projected future population growth, the projected future demand for single-family residences, as well as the development and management practices typically associated with new single-family residential development in the ETJ of Pflugerville. I hypothesize that due to Pflugerville’s proximity to Austin and Round Rock, in addition to the relative abundance of available land to the east of the city of Pflugerville, that it is likely to continue experiencing sustained population and residential development growth, particularly in the form of new single-family residences in the ETJ. A population projection was conducted up to the year 2030, which in conjunction with average persons-per-household and single-family home permitting data, estimates potential consumer demand for single-family residences. The imperative to prevent soil loss is conceptually linked to ecosystem service benefits resulting from healthy and intact soils, such as improved water quality and the regulation of peak flow rates during storm events. Single-family residential development is evaluated in terms of conventional on-the-ground construction practices gathered from interviews with developers of single-family homes in the Pflugerville ETJ, as well as planning and regulatory specialists. These analyses are intended to inform regulatory and decision making processes regarding the importance and potential integration of soil preservation and conservation at the individual construction site level.
Urban poverty in Pakistan
(2011-05) Zaidi, Syed Hashim; Wong, Patrick, 1956-; Bussell, Jennifer
This report analyzes the spatial shift occurring in the nature of poverty in Pakistan. Given the rapid urban growth in Pakistan, poor families residing in cities are confronted with limited employment opportunities, poor living conditions, minimal access to services, and face environmental and health risks. Macroeconomic factors such as slow economic growth, Structural Adjustment Programs, food inflation, low job creation rate and housing crisis have all contributed to the rise in urban poverty. The weak local government structure and a lack of community involvement in governance decisions have only worsened the situation. With a burgeoning urban population, it is imperative that the government introduces a holistic pro-poor development package that focuses on interventions in the education, labor and housing markets across Pakistan.