Improved hybrid genetics and more efficient farming techniques have increased corn (Zea mays L.) production and grain yields for Mid-South farmers. Early planting is one technique to mitigate heat and drought stress that negatively influence grain production. The first objective was: a) determine the effect of early planting on grain yield, b) to determine the effects on physiological characteristics and c) determine if some hybrids are better suited for early planting. Data suggest there were yield advantages for early planted treatments. Starkville 2014 yields exhibited the greatest reduction of .80 Mg ha-1 for each week that planting was delayed. A second objective was: a) determine optimum plant density when planting early, b) determine population effects on physiological characteristics, and c) determine hybrid responses. Hybrids were evaluated at seeding rates ranging from 49,400 to 98,800 plants ha-1. Corn grain yield was maximized at 86, 450 to 98,800 plants ha-1.

No description available.

No description available.

No description available.

In July of 2021, thousands of people took to the streets in different cities of the United States in demand of military intervention by the U.S. government and freedom for the people of Cuba. This study aims to explore the motivation behind the Florida-based Cuban American popula-tion to engage in acts of civic protest. The study explains the unique characteristics of the Cuban American Immigrant group in the United States influencing social movement participation. The study provides an analysis of the background of the S.O.S. Cuba movement. To accomplish this, in-depth focus groups were conducted to explore the opinions, reactions, and perspectives among the Cuban American population regarding S.O.S. Cuba. In these focus groups, participants shared their experiences, their Cuban identity, and how that identity has played a major role in informing their actions in the U.S. A qualitative content analysis revealed interviews four major: dictatorship trauma, detachment, gratitude to the U.S. government, and a history of sacrifice, struggles, and sadness. These prominent themes, along with their sub-themes, are used to understand why Cuban Americans, as a group, have been found to refrain from participating in major social movements and the influence of the S.O.S Cuba movement on the changing attitudes of political participation.

The primary purpose of this thesis is a description of some of the major changes which the population of Texas has undergone, particularly in the first half of the twentieth century. Other approaches are possible. For example, it is both possible and important to develop the relationship of population change to social problems. However, it is not the purpose of this thesis to investigate these relationships. It is the purpose here to view the population problem in almost entirely a factual sense, basing observations and interpretations on strictly demographic data.

Fertility decline in Zimbabwe has been driven by an increase in the contraceptive prevalence rate (CPR). However, adolescent childbearing remains a challenge. Adolescent fertility increased from 103 births per 1 000 women in 1988 to 110 births per 1 000 women in 2015. The study aims to examine the trends in contraceptive use, unmet need, method choice, and determinants of contraceptive use and method choice among young women aged 15-24 in Zimbabwe from 1988 to 2015. The study utilises six cross-sectional data sets obtained from the Zimbabwe Demographic and Health Survey (ZDHS) for the years 1988, 1994, 1999, 2005-06, 2010-11, and 2015. Descriptive statistics and multivariate logistic regression were used to achieve the objectives of the study. Results showed that young women are sexually active and mostly outside of marital union. The use of modern contraceptives among sexually active young women increased from 39.7% in 1988 to 58.2% in 2015. Unmet need for modern contraceptives declined from 54.1% in 1994 to 41.6% in 2015. The pill remains the most common method used, and the use of injections and implants has also increased over time. The results show that young women aged 22-24, residing in urban areas, better educated, employed, married or cohabitating, with one or more living children, and those with a desire to have more children after 2 years are more likely to use modern contraceptives compared to other groups. Whereas, widowed, divorced, or separated, and women with a desire to have more children within 2 years are less likely to use modern contraceptives. Young women who are married (OR=2.265), better educated (OR=1.590), and have one or more living children (OR=18.411) are more likely to use injections compared to other groups. Women with secondary or higher education (OR = 2.748) and one or more living children (OR= 22.673) are more likely to use Norplant/Implants compared to other groups. In conclusion, the study demonstrates that young women are sexually active and the unmet need for modern contraceptives remains a challenge. The use of contraceptives is associated with age group, residence, education level, employment status, marital status, parity, and desire for more children. There is need to strengthen young women's universal access to family planning information and services.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Computer-based, mathematical models have significant value in describing the processes behind urban development and its inhabitants. The following research describes the theories and concepts behind modeling and offers insight into the potential future of the field. First, the research covers a brief history of applicable modeling strategies. This is followed by a summary of current popular approaches. The numerical background of geo-social engineering is developed through mathematical techniques. Geo-social engineering is the integration of modeling into the basic design human civilization. The mathematical models will be incorporated into a design of a computer program. From this, a possible geo-social model structure is presented and its architecture is described.

The spread of infectious diseases has been a public concern throughout human history. Historic recorded data has reported the severity of infectious disease epidemics in different ages. Ancient Greek physician Hippocrates was the first to analyze the correlation between diseases and their environment. Nowadays, health authorities are in charge of planning strategies that guarantee the welfare of citizens. The simulation of contagion scenarios contributes to the understanding of the epidemic behavior of diseases. Computational models facilitate the study of epidemics by integrating disease and population data to the simulation. The use of detailed demographic and geographic characteristics allows researchers to construct complex models that better resemble reality and the integration of these attributes permits us to understand the rules of interaction. The interaction of individuals with similar characteristics forms synthetic structures that depict clusters of interaction. The synthetic environments facilitate the study of the spread of infectious diseases in diverse scenarios. The characteristics of the population and the disease concurrently affect the local and global epidemic progression. Every cluster’ epidemic behavior constitutes the global epidemic for a clustered population. By understanding the correlation between structured populations and the spread of a disease, current dissertation research makes possible to identify risk groups of specific characteristics and devise containment strategies that facilitate health authorities to improve mitigation strategies.