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Full-Text Articles in Life Sciences

Evolution And Functional Morphology Of The Cephalic Lobes In Batoids, Samantha Lynn Mulvany Dec 2013

Evolution And Functional Morphology Of The Cephalic Lobes In Batoids, Samantha Lynn Mulvany

Graduate Theses and Dissertations

Cephalic lobes are unique structures derived from the anterior pectoral fins, found in select myliobatid stingrays. Many benthic batoids utilize undulatory locomotion and use their pectoral fins for both locomotion and prey capture. Pelagic myliobatids that possess cephalic lobes utilize oscillatory locomotion, using their pectoral fins to locomote and their cephalic lobes for prey capture. Despite differences in habitat usage and locomotor modes, these batoids feed on very similar benthic organisms. The purpose of this study was to 1.) compare the morphology of the cephalic lobes and anterior pectoral fins in lobed and lobeless species, looking at skeletal elements, musculature ...


Correction For Rapid-Growth Vegetation And Testing Of An Upscaling Method With A Cosmos Probe, Samantha Lou Irvin Jan 2013

Correction For Rapid-Growth Vegetation And Testing Of An Upscaling Method With A Cosmos Probe, Samantha Lou Irvin

Graduate Theses and Dissertations

COSMOS (COsmic-ray Soil Moisture Observing System) probes are a developing instrument in the field of remote sensing and are currently the only source of field scale soil moisture data. A COSMOS probe is essentially a hydrogen particle counter with a measurement depth ranging from 10-70 cm and a spatial resolution approaching 700 m in diameter. A majority of the hydrogen detected is in the form of water molecules. As vegetation contains both hydrogen in the vegetative dry matter and water, in addition to sitting above the ground, it may influence what is measured by the COSMOS probe as soil moisture ...


An Analysis Of Technical Assistance Providers In Copanch'orti' Guatemala, Victoria Lebeaux Jan 2013

An Analysis Of Technical Assistance Providers In Copanch'orti' Guatemala, Victoria Lebeaux

Graduate Theses and Dissertations

Guatemala has the fourth highest rate of chronic under-nutrition for children under five in the world. One region particularly impacted is the Copanch'orti' area of eastern Guatemala where chronic under-nutrition affected 61% of the population in 2008. Although efforts to solve the malnutrition problem have been underway for several decades, there is a persistent need for greater and better coordination and integration of food security programming, within and across sectors (agriculture, education, environment, health, etc.), as well as across local, regional, and national platforms. In this dissertation I addressed the question of how the actions of development practitioners can ...


Learning And Power In International Farmer Exchanges, Stephen August Lauer Jan 2013

Learning And Power In International Farmer Exchanges, Stephen August Lauer

Graduate Theses and Dissertations

The "Bridging the Gap" program provides an opportunity to explore the relationships between learning and power in international agricultural development partnerships. A USAID-funded partnership between Iowa State University and Volunteer Efforts for Development Concerns, this farmer-to-farmer program sent groups of Iowan women farmers to Uganda to teach Ugandan women farmers with the objectives that Ugandans would move from subsistence to commercial farming and that both groups would benefit from the cultural exchange. Data were collected primarily through semi-structured qualitative interviews of 28 Ugandan farmers, 7 Iowan farmers, and several program staff, and were analyzed using a grounded-theory approach. This thesis ...


Green Roof Biodiversity In Design: Influence Of Local And Contextual Attributes On Bird Usage, Henry Narigon Jan 2013

Green Roof Biodiversity In Design: Influence Of Local And Contextual Attributes On Bird Usage, Henry Narigon

Graduate Theses and Dissertations

This purpose of this research is to identify how species of birds use urban green roofs in Iowa with the intent to eventually develop a set of guidelines for optimizing habitat on green roofs. Ten green roofs were observed for bird usage five times each between May to August, 2013 for a total of fifty observations. Birds were identified by species and their behavior was recorded during the duration of the observations. Data shows that birds use green roofs for a number of uses including foraging and gathering nest material. Bird diversity data was then compared with both green roof ...


Validation And Calibration Of Self-Report Methods: The Youth Activity Profile, Pedro Frederico De Saint-Maurice Maduro Jan 2013

Validation And Calibration Of Self-Report Methods: The Youth Activity Profile, Pedro Frederico De Saint-Maurice Maduro

Graduate Theses and Dissertations

The development of more accurate and precise methods of assessing physical activity behavior is an important public health research priority. Objective monitoring devices have advantages but the high cost and burden of data processing make them impractical for large scale applications. Subjective (survey-based) tools are inexpensive and easy to use but these suffer from questionable validity. Objective measures are often used to validate less accurate measures such as subjective instruments but this does not directly improve the accuracy or precision of the self-report instrument. The proposed line of research developed and tested a calibration equation approach that enabled data from ...


Immunosenescence And Exercise-Mediated Modulation Of The Innate Immune Response To Influenza Infection In Mice, Shibani Naik Jan 2013

Immunosenescence And Exercise-Mediated Modulation Of The Innate Immune Response To Influenza Infection In Mice, Shibani Naik

Graduate Theses and Dissertations

Influenza virus is a negative sense, single stranded RNA virus that can cause severe respiratory tract infections in humans (along with other host animals such as horses, swine and poultry). Certain populations such as very young children, aged individuals, pregnant women and immunosuppressed individuals are more susceptible to influenza infections. One reason for the increased susceptibility to infection in the aged is a decreased efficacy of the seasonal influenza vaccine. As this particular section of our population continues to increase worldwide, research to improve vaccine efficacy is expanding along with efforts to identify lifestyle changes and interventions that can improve ...


Smallholder Farmer Assets, Extension And Marketing In Uganda, Qian Sun Jan 2013

Smallholder Farmer Assets, Extension And Marketing In Uganda, Qian Sun

Graduate Theses and Dissertations

The study was initiated to understand how asset building, combined with appropriate extension services, can enable smallholder farmers to address marketing problems. Interviews were conducted in 2009 with 317 farm households in Kamuli district, Eastern Uganda, who were participants in a sustainable rural livelihoods program, led by an indigenous non-governmental organization with support from Ugandan and U.S. universities. Training and support provided opportunities to improve production of crops and livestock, income, nutrition and well-being. Key research questions are: (i) How is the level of smallholders' assets associated with access to extension services? (ii) What influence do assets and extension ...


Mechanization Potential For Expanding Midwestern Fruit And Vegetable Enterprises, Nicholas Jon Pates Jan 2013

Mechanization Potential For Expanding Midwestern Fruit And Vegetable Enterprises, Nicholas Jon Pates

Graduate Theses and Dissertations

Midwestern fruit and vegetable farmers face challenges in expanding their farms. Growing fruit and vegetables remains a labor intensive industry and most of the country's commercial production takes place on large scale farms in the Western United States. Mechanization may aid farmers in scaling up production by offsetting labor costs. This report uses a six-farm case study and a survey to examine the trends of both labor and machine use over different levels of production. Larger farms tended to use more labor and machinery but machinery seems to exhibit a degree of labor savings potential. The context of expansions ...


The Trade Effects, Protectionism, And Political Economy Of Non-Tariff Measures, Yuan Li Jan 2013

The Trade Effects, Protectionism, And Political Economy Of Non-Tariff Measures, Yuan Li

Graduate Theses and Dissertations

Non-tariff measures (NTMs) have become increasingly present in markets whereas border tariffs have been reduced from successive rounds of General Agreement on Tariffs and Trade (GATT) and the World Trade Organization (WTO). This emergence of NTMs, especially standards like NTMs, has been also motivated by concerns about market imperfections to address asymmetric information and external effects. Sorting protectionism from legitimate market intervention has been difficult and attempts have lack formalism. In addition, the empirical evidence on the impact of these NTMs on trade flows has been cluttered with few obvious implications for policy design. The first essay takes a meta-analysis ...


Integrated Classroom Physical Activity: Examining Perceived Need Satisfaction And Academic Performance In Children, Miriam Ann Blom Skrade Jan 2013

Integrated Classroom Physical Activity: Examining Perceived Need Satisfaction And Academic Performance In Children, Miriam Ann Blom Skrade

Graduate Theses and Dissertations

Physical activity is related to better academic performance and prevention of childhood obesity. Classroom-based physical activities, based on recent research studies, seem to target both areas successfully. Move for Thought (M4T) is a recently developed kit that integrates physical activities into academic lessons in the classroom. This thesis is the first to examine the kit's impact on children's motivation and math performance. The study aimed to see (a) if eight weeks of M4T integrated with math, compared to traditional lessons (control), would elicit a gain in math performance and (b) if the basic psychological needs in math (autonomy ...


Essays On Agricultural, Financial Economics And Education, Juan Manuel Murguia Baysse Jan 2013

Essays On Agricultural, Financial Economics And Education, Juan Manuel Murguia Baysse

Graduate Theses and Dissertations

This dissertation is devoted to the study of three different topics under the advice of three different mayor professors. The only thing these topics have in common is the interest and curiosity of the author to explain real life events, using applied econometric techniques. Chapter 2 applies financial tools to assess whether stock values reacted across world markets to the announcement of indexes that synthesize the environmental performance of the world's largest publicly-traded companies. The environmental index selected for this purpose is the "Global 100 Ranking" (G100), a ranking of the 100 largest public companies by market capitalization. The ...


Corn Yield Variability On The Des Moines Lobe Of Iowa: Assessment Of Extent And Soil-Related Causes, Matthew Thomas Streeter Jan 2013

Corn Yield Variability On The Des Moines Lobe Of Iowa: Assessment Of Extent And Soil-Related Causes, Matthew Thomas Streeter

Graduate Theses and Dissertations

Precision agriculture techniques are an essential component to modern row crop agriculture in Iowa and can be used to create crop yield variability maps via geographic information systems. The first objective of this thesis was to explore the methodology that could be used to locate significant long-term corn yield variability on the Iowa Des Moines Lobe. A 158-ha site, consisting mainly of Clarion, Nicollet and Webster soil map units and containing multiple years of geo-referenced corn (Zea mays) yield data was selected. A cluster analysis tool was performed to locate spatially consistent corn yield variability (high, low and mean yield ...


"They Come, But They Don't Spend As Much Money": Livelihoods, Dietary Diversity, Food Security, And Nutritional Status In Two Roatan Communities In The Wake Of Global Crises In Food Prices And Finance, Racine Marcus Brown Jan 2013

"They Come, But They Don't Spend As Much Money": Livelihoods, Dietary Diversity, Food Security, And Nutritional Status In Two Roatan Communities In The Wake Of Global Crises In Food Prices And Finance, Racine Marcus Brown

Graduate Theses and Dissertations

ABSTRACT

This dissertation explores the associations between recent global crises in staple food prices and finance and the following aspects of life in two communities on the island of Roatàn, Islas de La Bahia (Bay Islands), Honduras: household livelihoods; food commoditization; dietary diversity; food security; and nutritional status. The aims of this study are: ) assess the geographic and economic source(s) of foods consumed by two different communities on Roatàn; b) discover how the most recent economic and food crises have affected foodways and nutrition on Roatàn; c) assess how these crises have affected economic growth of the tourism sector ...


Connecting Pixels To People: Management Agents And Social-Ecological Determinants Of Changes To Street Tree Distributions, Shawn Landry Jan 2013

Connecting Pixels To People: Management Agents And Social-Ecological Determinants Of Changes To Street Tree Distributions, Shawn Landry

Graduate Theses and Dissertations

Street trees are an important component of the urban forest that can provide direct and indirect benefits to social and ecological sustainability in cities. Temporal and spatial interactions between human and non-human management agents determine the distribution and health of street tree populations in urban areas. This dissertation seeks to enhance our understanding of the spatial patterns and processes affecting street trees by investigating the agents and social-ecological determinants of changes to street tree distributions in urban residential neighborhoods. The research was guided by three primary questions: (1) Are recent changes to the spatial distribution of street trees influenced by ...


Cultivating Local: Building A Local Food System In Western North Carolina, Allison S. Perrett Jan 2013

Cultivating Local: Building A Local Food System In Western North Carolina, Allison S. Perrett

Graduate Theses and Dissertations

This dissertation examines a movement in Western North Carolina to build a local food system, one grounded in the conditions and relationships of place. In 2000, Mountain Family Farms launched the Local Food Campaign to raise public awareness about the region's farms and farming heritage, to educate consumers about the benefits of buying food grown by local farms, and, ultimately, to build markets for locally grown food to sustain the region's farms. The campaign sparked a social movement and over a decade later local farms and locally grown food are a palpable feature of life in the mountains ...


Agricultural And Domestic Waste Contamination In Chilibre Panama And Potential Low-Cost Best Managament Practices, Christopher Etienne Weekes Jan 2013

Agricultural And Domestic Waste Contamination In Chilibre Panama And Potential Low-Cost Best Managament Practices, Christopher Etienne Weekes

Graduate Theses and Dissertations

Abstract

Sanitation coverage in the Republic of Panama is 5 to 10 percent below the Millennium Development Goals targets set for the country. Population growth, urbanization, unplanned development and waste mismanagement have resulted in improvised trash sites and waste discharges into river systems that are important components of the biologically diverse natural environment of Panama. The study sought to investigate and estimate the burden of waste from domestic and agricultural sources in three regions of the Chilibre corrigimiento (district). It was hypothesized that the water quality and land cover data would reflect that the most populated region in the study ...


Prenatal Stress, Depression, And Herpes Viral Titers, Pao-Chu Hsu Jan 2013

Prenatal Stress, Depression, And Herpes Viral Titers, Pao-Chu Hsu

Graduate Theses and Dissertations

Recent studies suggest that some cases of prenatal depression may be associated with reactivation of latent infections of the herpesvirus family. The possible relationships among stress, prenatal depression, and herpes viral reactivation in pregnancy are understudied and the molecular pathways such as the neuroimmune biogenic amine pathway are unidentified. Chronic stress shifts the T helper-1 cell (Th1) cytokine profile to a Th2 profile, which favors virus induced pathogenesis and survival. Pregnancy is also associated with a similar Th2 dominance. In non-pregnant individuals, exposure to psychological or physical stress may be associated with latent herpes viral reactivation and could result in ...


Evaluating Habitat Vulnerability And Sustainability Of Urban Seagrass Resources To Sea Level Rise, Cynthia A. Meyer Jan 2013

Evaluating Habitat Vulnerability And Sustainability Of Urban Seagrass Resources To Sea Level Rise, Cynthia A. Meyer

Graduate Theses and Dissertations

The seagrass resource provides essential ecosystem functions for many marine species. This research evaluated the vulnerability and sustainability of the seagrass resource in an urbanized area to the effects of sea level rise. The assessment required analysis of information regarding the biogeography of the seagrass resource, and developing a method to model the spatial extent of the suitable habitat for seagrass, and applying the model to predict the implications of simulated sea level rise scenarios on the seagrass resource.

Examining the biogeography of the seagrass resource required the development of a seagrass monitoring and assessment field survey and a comprehensive ...