The role of teleost grazers in a relatively pristine seagrass ecosystem

Trophic downgrading of ecosystems necessitates a functional understanding of trophic cascades. Identifying the presence of cascades, and the mechanisms through which they occur, is particularly important for seagrass meadows, which are among the most threatened ecosystems on Earth. Shark Bay, Western Australia provides a model system to investigate the potential importance of top-down effects in a relatively pristine seagrass ecosystem. The role of megagrazers in the Shark Bay system has been previously investigated, but the role of macrograzers (i.e., teleosts), and their importance relative to megagrazers, remains unknown. The objective of my dissertation was to elucidate the importance of teleost macrograzers in transmitting top-down effects in seagrass ecosystems. Seagrasses and macroalgae were the main food of the abundant teleost Pelates octolineatus, but stable isotopic values suggested that algae may contribute a larger portion of assimilated food than suggested by gut contents. Pelates octolineatus is at risk from numerous predators, with pied cormorants (Phalacrocorax varius) taking the majority of tethered P. octolineatus. Using a combination of fish trapping and unbaited underwater video surveillance, I found that the relative abundance of P. octolineatus was greater in interior areas of seagrass banks during the cold season, and that the mean length of P. octolineatus was greater in these areas compared to along edges of banks. Finally, I used seagrass transplants and exclosure experiments to determine the relative effect of megagrazers and macrograzers on the establishment and persistence of three species of seagrasses in interior microhabitats. Teleost grazing had the largest impact on seagrass species with the highest nutrient content, and these impacts were primarily observed during the warm season. My findings are consistent with predictions of a behaviorally-mediated trophic cascade initiated by tiger sharks (Galeocerdo cuvier) and transmitted through herbivorous fishes and their predators.

Human-driven benthic jellyfish blooms: Causes and consequences for coastal marine ecosystems

Coastal marine ecosystems are among the most impacted globally, attributable to individual and cumulative effects of human disturbance. Anthropogenic nutrient loading is one stressor that commonly affects nearshore ecosystems, including seagrass beds, and has positive and negative effects on the structure and function of coastal systems. An additional, previously unexplored mechanistic pathway through which nutrients may indirectly influence nearshore systems is by driving blooms of benthic jellyfish. My dissertation research, conducted on Abaco Island, Bahamas, focused on elucidating the role that benthic jellyfish have in structuring systems in which they are common (i.e., seagrass beds), and explored mechanistic processes that may drive blooms of this taxa. ^ To establish that human disturbances (e.g., elevated nutrient availability) may drive increased abundance and size of benthic jellyfish, Cassiopea spp., I conducted surveys in human-impacted and unimpacted coastal sites. Jellyfish were more abundant (and larger) from human-impacted areas, positively correlated to elevated nutrient availability. In order to elucidate mechanisms linking Cassiopea spp. with elevated nutrients, I evaluated whether zooxanthellae from Cassiopea were higher from human-disturbed systems, and whether Cassiopea exhibited increased size following nutrient input. I demonstrated that zooxanthellae population densities were elevated in human-impacted sites, and that nutrients led to positive jellyfish growth. ^ As heightened densities of Cassiopea jellyfish may exert top-down and bottom-up controls on flora and fauna in impacted seagrass beds, I sought to examine ecological responses to Cassiopea. I evaluated whether there was a relationship between high Cassiopea densities and lower benthic fauna abundance and diversity in shallow seagrass beds. I found that Cassiopea have subtle effects on benthic fauna. However, through an experiment conducted in a seagrass bed in which nutrients and Cassiopea were added, I demonstrated that Cassiopea can result in seagrass habitat modification, with negative consequences for benthic fauna. ^ My dissertation research demonstrates that increased human-driven benthic jellyfish densities may have indirect and direct effects on flora and fauna of coastal marine systems. This knowledge will advance our understanding of how human disturbances shift species interactions in coastal ecosystems, and will be critical for effective management of jellyfish blooms.^

Foreign Language Education in Colombia: A Qualitative Study of Escuela Nueva

Since 2004 the Colombian Ministry of Education has been implementing the Programa Nacional de Biling��ismo (PNB) with the goal of having bilingual high school graduates in English and Spanish by 2019. However, implementation of the PNB has been criticized by English Language Teaching (ELT) specialists in the country who say, among other things, that the PNB introduced a discourse associated exclusively with bilingualism in English and Spanish. This study analyzed interviews with 15 participants of a public school of the Colombian Escuela Nueva, a successful model of community-based education that has begun a process of internationalization, regarding the participants��� perceptions of foreign language education and the policies of the PNB. Six students, five teachers, and four administrators were each interviewed twice using semi-structured interviews. To offer a critique of the PNB, this study tried to determine to what extent the school implemented the elements of Responsible ELT, a model developed by the researcher incorporating the concepts of hegemony of English, critical language-policy research, and resistance in ELT. Findings included the following: (a) students and teachers saw English as the universal language whereas most administrators saw English imposed due to political and economic reasons; (b) some teachers misinterpreted the 1994 General Law of Education mandating the teaching of a foreign language as a law mandating English; and (c) some teachers and administrators saw the PNB���s adoption of competence standards based on the Common European Framework of Reference for languages as beneficial whereas others saw it as arbitrary. Conclusions derived from this study of this Escuela Nueva school were: (a) most participants found the goal of the PNB unrealistic; (b) most teachers and administrators saw the policies of the PNB as top-down policies without assessment or continuity; and (c) teachers and administrators mentioned a disarticulation between elementary and high school ELT policies that may be discouraging students in public schools from learning English. Thus, this study suggests that the policies of the PNB may be contributing to English becoming a gatekeeper for higher education and employment thereby becoming a tool for sustaining inequality in Colombia.

A Study of Teachers' Espoused Instructional Beliefs

The purpose of this study was to investigate teachers��� espoused instructional beliefs and whether they differed in relation to schools��� socioeconomic status, extent of teachers��� educational background, or extent of teachers��� classroom experience. The study comprised a total of 242 Miami-Dade County public school educators who responded to a thirty-nine question Likert scale, Literacy Instructional Practices Questionnaire. Eighteen schools, three from each of the six regions, were purposively selected based on the socioeconomic status of students. Nine participants were interviewed using semi-standardized interview procedures and open-ended questioning techniques. Multivariate Analysis of Variance (MANOVA) results revealed that teachers��� espoused beliefs concerning the instruction of literacy and forces and influences affecting instruction do not significantly differ depending on schools��� socioeconomic status, extent of teachers��� educational background, or extent of teachers��� classroom experience. The majority of teachers appear to follow a top-down generated direct instruction model. Generally, students are taught as a whole class and ability grouped for specific skill instruction utilizing commercially produced reading and language arts texts. There was no evidence of a relationship between teachers��� espoused beliefs concerning the model of instruction that they practice or teachers��� espoused beliefs concerning research and its application to practice and the three independent variables. Interview data corroborated much of the information garnered through the questionnaire. However, interview participants espoused the belief that research did not influence their selection of instructional practices. Although teachers perceive of themselves as eclectic in their espoused instructional beliefs, they appear to follow a skills based direct instruction pedagogy in practice. Much of what teachers believe constitutes effective practice, few researchers recommend, affirming the findings of Calderhead (1993) and the National Educational Research Policy and Priorities Board (U.S. Department of Education, 1998, p. 18) that ���educators rarely know research, seek it out, or act in accordance with its results.���

A Capability Maturity Model to Assess Supply Chain Performance

In an overcapacity world, where the customers can choose from many similar products to satisfy their needs, enterprises are looking for new approaches and tools that can help them not only to maintain, but also to increase their competitive edge. Innovation, flexibility, quality, and service excellence are required to, at the very least, survive the on-going transition that industry is experiencing from mass production to mass customization. In order to help these enterprises, this research develops a Supply Chain Capability Maturity Model named S(CM)2. The Supply Chain Capability Maturity Model is intended to model, analyze, and improve the supply chain management operations of an enterprise. The Supply Chain Capability Maturity Model provides a clear roadmap for enterprise improvement, covering multiple views and abstraction levels of the supply chain, and provides tools to aid the firm in making improvements. The principal research tool applied is the Delphi method, which systematically gathered the knowledge and experience of eighty eight experts in Mexico. The model is validated using a case study and interviews with experts in supply chain management. The resulting contribution is a holistic model of the supply chain integrating multiple perspectives, and providing a systematic procedure for the improvement of a company���s supply chain operations.

The Role of Teleost Grazers in a Relatively Pristine Seagrass Ecosystem

Trophic downgrading of ecosystems necessitates a functional understanding of trophic cascades. Identifying the presence of cascades, and the mechanisms through which they occur, is particularly important for seagrass meadows, which are among the most threatened ecosystems on Earth. Shark Bay, Western Australia provides a model system to investigate the potential importance of top-down effects in a relatively pristine seagrass ecosystem. The role of megagrazers in the Shark Bay system has been previously investigated, but the role of macrograzers (i.e., teleosts), and their importance relative to megagrazers, remains unknown. The objective of my dissertation was to elucidate the importance of teleost macrograzers in transmitting top-down effects in seagrass ecosystems. Seagrasses and macroalgae were the main food of the abundant teleost Pelates octolineatus, but stable isotopic values suggested that algae may contribute a larger portion of assimilated food than suggested by gut contents. Pelates octolineatus is at risk from numerous predators, with pied cormorants (Phalacrocorax varius) taking the majority of tethered P. octolineatus. Using a combination of fish trapping and unbaited underwater video surveillance, I found that the relative abundance of P. octolineatus was greater in interior areas of seagrass banks during the cold season, and that the mean length of P. octolineatus was greater in these areas compared to along edges of banks. Finally, I used seagrass transplants and exclosure experiments to determine the relative effect of megagrazers and macrograzers on the establishment and persistence of three species of seagrasses in interior microhabitats. Teleost grazing had the largest impact on seagrass species with the highest nutrient content, and these impacts were primarily observed during the warm season. My findings are consistent with predictions of a behaviorally-mediated trophic cascade initiated by tiger sharks (Galeocerdo cuvier) and transmitted through herbivorous fishes and their predators.

Middle school teachers perspectives on inclusion: A qualitative study

Historically, research has placed considerable emphasis on developing a systematic body of knowledge about education in which little voice has been given to teachers themselves. The critical role that teachers play in this generative process such as reflecting, acting and theorizing upon practices that shape life in the classroom has largely been ignored in favor of technical innovation and organizational procedure. As schools struggle to reform and restructure, an understanding of how teachers interpret their practices in context and how the culture of schools influence, constrain, or encourage these practices become critical aspects of school success or failure. ^ This study examined the perspectives on inclusion of seven middle school teachers as they attempted to include exceptional students in regular classes. The study utilized three forms of data collection: observations were made of participant interactions as they led their everyday school lives; document analysis was used as a means to gain an understanding of programs affecting exceptional students, and interviews were used to give voice to teacher's perceptions regarding inclusion, allowing description in their own words rather than those imposed by an outside inquirer. Data collection and analysis sought to identify emerging themes, categories and patterns, allowing for the creation of substantive theory grounded in empirical data. ^ The key issues that emerged in the study were considered in terms of three general categories. The first, teaching and learning, revealed stark contrasts in opinions regarding the type of human support thought necessary for successful inclusion. Regular educators clung to the traditional notion of solitary teachers directing all class activity, while exceptional educators preferred a more team-oriented approach. The second, school structure, revealed that highly collaborative structures were only partially successful in creating additional conversation between regular and exceptional educators. Collegiality was affected by lack of staff experience with the process as well as its implementation in a top-down fashion. The third, school culture and climate, revealed that regular educators believed the school was prepared for a limited amount of inclusion. Although exceptional educators acknowledged school readiness, they did not believe that inclusion was an important item on the school's reform agenda. ^

Relative significance of pelagic, benthic and allochthonous organic matter to microbial carbon cycling in a phosphorus-depleted subtropical estuary (Florida Bay)

Heterotrophic bacteria are important decomposers and transformers of primary production and provide an important link between detritus and the aquatic food web. In seagrass ecosystems, much of seagrass primary production is unavailable through direct grazing and must undergo microbial reworking before seagrass production can enter the aquatic food web. The goal of my dissertation research is to understand better the role heterotrophic bacteria play in carbon cycling in seagrass estuaries. My dissertation research focuses on Florida Bay, a seagrass estuary that has experienced recent changes in carbon source availability, which may have altered ecosystem function. My dissertation research investigates the importance of seagrass, algal and/or cyanobacterial, and allochthonous-derived organic matter to heterotrophic bacteria in Florida Bay and helps establish the carbon base of the estuarine food web. ^ A three tiered approach to the study of heterotrophic bacterial carbon cycling and trophic influences in Florida Bay was used: (1) Spatiotemporal observations of environmental parameters (hydrology, nutrients, extracellular enzymes, and microbial abundance, biomass, and production); (2) Microbial grazing experiments under different levels of top-down and bottom-up influence; and (3) Bulk and compound-specific (bacteria-biomarker fatty acid analysis) stable carbon isotope analysis. ^ In Florida Bay, spatiotemporal patterns in microbial extracellular enzyme (also called ectoenzyme) activities indicate that microorganisms hydrolyzed selectively fractions of the estuarine organic matter pool. The microbial community hydrolyzed organic acids, peptides, and phosphate esters and did not use storage and structural carbohydrates. Organic matter use by heterotrophic bacterioplankton in Florida Bay was co-regulated by bottom-up (resource availability) and top-down (grazer mediated) processes. A bacterial carbon budget based on bacterial, epiphytic, and seagrass production indicates that heterotrophic bacterial carbon cycles are supported primarily through epiphytic production with mixing from seagrass production. Stable carbon isotope analysis of bacteria biomarkers and carbon sources in Florida Bay corroborate the results of the bacterial carbon budget. These results support previous studies of aquatic consumers in Florida Bay, indicating that epiphytic/benthic algal and/or cyanobacterial production with mixing from seagrass-derived organic matter is the carbon base of the seagrass estuarine food web. ^

Negotiating identities, striving for state recognition: Blacks in C��rdoba, Argentina 1776���1853

Race in Argentina played a significant role as a highly durable construct by identifying and advancing subjects (1776���1810) and citizens (1811���1853). My dissertation explores the intricacies of power relations by focusing on the ways in which race informed the legal process during the transition from a colonial to national State. It argues that the State���s development in both the colonial and national periods depended upon defining and classifying African descendants. In response, people of African descendent used the State���s assigned definitions and classifications to advance their legal identities. It employs race and culture as operative concepts, and law as a representation of the sometimes, tense relationship between social practices and the State���s concern for social peace. This dissertation examines the dynamic nature of the court. It utilizes the theoretical concepts multicentric legal orders that are analyzed through weak and strong legal pluralisms, and jurisdictional politics, from the late eighteenth to early nineteenth centuries. This dissertation juxtaposes various levels of jurisdiction (canon/state law and colonial/national law) to illuminate how people of color used the legal system to ameliorate their social condition. In each chapter the primary source materials are state generated documents which include criminal, ecclesiastical, civil, and marriage dissent court cases along with notarial and census records. Though it would appear that these documents would provide a superficial understanding of people of color, my analysis provides both a top-down and bottom-up approach that reflects a continuous negotiation for African descendants��� goal for State recognition. These approaches allow for implicit or explicit negotiation of a legal identity that transformed slaves and free African descendants into active agents of their own destinies.

Stable isotopes reveal complex changes in trophic relationships following nutrient addition in a coastal marine ecosystem

Complex links between the top-down and bottomup forces that structure communities can be disrupted by anthropogenic alterations of natural habitats.We used relative abundance and stable isotopes to examine changes in epifaunal food webs in seagrass (Thalassia testudinum) beds following 6 months of experimental nutrient addition at two sites in Florida Bay (USA) with different ambient fertility. At a eutrophic site, nutrient addition did not strongly affect food web structure, but at a nutrient-poor site, enrichment increased the abundances of crustacean epiphyte grazers, and the diets of these grazers became more varied. Benthic grazers did not change in abundance but shifted their diet away from green macroalgae + associated epiphytes and towards an opportunistic seagrass (Halodule wrightii) that occurred only in nutrient addition treatments. Benthic predators did not change in abundance, but their diets were more varied in enriched plots. Food chain length was short and unaffected by site or nutrient treatment, but increased food web complexity in enriched plots was suggested by increasingly mixed diets. Strong bottom-up modifications of food web structure in the nutrient-limited site and the limited top-down influences of grazers on seagrass epiphyte biomass suggest that, in this system, the bottom-up role of nutrient enrichment can have substantial impacts on community structure, trophic relationships, and, ultimately, the productivity values of the ecosystem.

Fire and grazing in a mesic tallgrass prairie: impacts on plant species and functional traits

Fire is a globally distributed disturbance that impacts terrestrial ecosystems and has been proposed to be a global ���herbivore.��� Fire, like herbivory, is a top-down driver that converts organic materials into inorganic products, alters community structure, and acts as an evolutionary agent. Though grazing and fire may have some comparable effects in grasslands, they do not have similar impacts on species composition and community structure. However, the concept of fire as a global herbivore implies that fire and herbivory may have similar effects on plant functional traits. Using 22 years of data from a mesic, native tallgrass prairie with a long evolutionary history of fire and grazing, we tested if trait composition between grazed and burned grassland communities would converge, and if the degree of convergence depended on fire frequency. Additionally, we tested if eliminating fire from frequently burned grasslands would result in a state similar to unburned grasslands, and if adding fire into a previously unburned grassland would cause composition to become more similar to that of frequently burned grasslands. We found that grazing and burning once every four years showed the most convergence in traits, suggesting that these communities operate under similar deterministic assembly rules and that fire and herbivory are similar disturbances to grasslands at the trait-group level of organization. Three years after reversal of the fire treatment we found that fire reversal had different effects depending on treatment. The formerly unburned community that was then burned annually became more similar to the annually burned community in trait composition suggesting that function may be rapidly restored if fire is reintroduced. Conversely, after fire was removed from the annually burned community trait composition developed along a unique trajectory indicating hysteresis, or a time lag for structure and function to return following a change in this disturbance regime. We conclude that functional traits and species-based metrics should be considered when determining and evaluating goals for fire management in mesic grassland ecosystems.

Regional processes in mangrove ecosystems: spatial scaling relationships, biomass, and turnover rates following catastrophic disturbance

Physiological processes and local-scale structural dynamics of mangroves are relatively well studied. Regional-scale processes, however, are not as well understood. Here we provide long-term data on trends in structure and forest turnover at a large scale, following hurricane damage in mangrove ecosystems of South Florida, U.S.A. Twelve mangrove vegetation plots were monitored at periodic intervals, between October 1992 and March 2005. Mangrove forests of this region are defined by a ���1.5 scaling relationship between mean stem diameter and stem density, mirroring self-thinning theory for mono-specific stands. This relationship is reflected in tree size frequency scaling exponents which, through time, have exhibited trends toward a community average that is indicative of full spatial resource utilization. These trends, together with an asymptotic standing biomass accumulation, indicate that coastal mangrove ecosystems do adhere to size-structured organizing principles as described for upland tree communities. Regenerative dynamics are different between areas inside and outside of the primary wind-path of Hurricane Andrew which occurred in 1992. Forest dynamic turnover rates, however, are steady through time. This suggests that ecological, more-so than structural factors, control forest productivity. In agreement, the relative mean rate of biomass growth exhibits an inverse relationship with the seasonal range of porewater salinities. The ecosystem average in forest scaling relationships may provide a useful investigative tool of mangrove community biomass relationships, as well as offer a robust indicator of general ecosystem health for use in mangrove forest ecosystem management and restoration.

Organized labor and U.S. foreign policy: The Solidarity Center in historical context

During the Cold War the foreign policy of the American Federation of Labor and Congress of Industrial Organizations (AFL-CIO), was heavily criticized by scholars and activists for following the lead of the U.S. state in its overseas operations. In a wide range of states, the AFL-CIO worked to destabilize governments selected by the U.S. state for regime change, while in others the Federation helped stabilize client regimes of the U.S. state. In 1997 the four regional organizations that previously carried out AFL-CIO foreign policy were consolidated into the American Center for International Labor Solidarity (Solidarity Center). My dissertation is an attempt to analyze whether the foreign policy of the AFL-CIO in the Solidarity Center era is marked by continuity or change with past practices. At the same time, this study will attempt to add to the debate over the role of non-governmental organizations (NGOs) in the post-Cold War era, and its implications for future study. Using the qualitative "process-tracing" detailed by of Alexander George and Andrew Bennett (2005) my study examines a wide array of primary and secondary sources, including documents from the NED and AFL-CIO, in order to analyze the relationship between the Solidarity Center and the U.S. state from 2002-2009. Furthermore, after analyzing broad trends of NED grants to the Solidarity Center, this study examines three dissimilar case studies including Venezuela, Haiti, and Iraq and the Middle East and North African (MENA) region to further explore the connections between U.S. foreign policy goals and the Solidarity Center operations. The study concludes that the evidence indicates continuity with past AFL-CIO foreign policy practices whereby the Solidarity Center follows the lead of the U.S. state. It has been found that the patterns of NED funding indicate that the Solidarity Center closely tailors its operations abroad in areas of importance to the U.S. state, that it is heavily reliant on state funding via the NED for its operations, and that the Solidarity Center works closely with U.S. allies and coalitions in these regions. Finally, this study argues for the relevance of "top-down" NGO creation and direction in the post-Cold War era.

Deprofessionalization of curriculum decision -making

The purpose of this study was to analyze the evolution of Florida state level policy efforts and to assess the responding educational policy development and implementation at the local school district level. The focus of this study was the secondary language arts curriculum in Miami-Dade County Public Schools. ^ Data was collected using document analysis as a source of meaning making out of the language sets proffered by agencies at each level. A matrix was created based on Klein's levels of curriculum decision-making and Functional Process Theory categories of policy formation. The matrix allowed the researcher to code and classify specific information in terms accountability/high-stakes testing; authority; outside influences; and operational/structural organization. ^ Federal policy documents provided a background and impetus for much of what originated at the State level. The State then produced policy directives which were accepted by the District and specific policy directives and guidelines for practice. No evidence was found indicating the involvement of any other agencies in the development, transmission or implementation of the State level initiated policies. ^ After analyzing the evolutionary process, it became clear that state policy directives were never challenged or discussed. Rather, they were accepted as standards to be met and as such, school districts complied. Policy implementation is shown to be a top-down phenomenon. No evidence was found indicating a dialogue between state and local systems, rather the state, as the source of authority, issued specifically worded policy directives and the district complied. Finally, this study recognizes that outside influences play an important role in shaping the education reform policy in the state of Florida. The federal government, through NCLB and other initiatives created a climate which led almost naturally to the creation of the Florida A+ Plan. Similarly, the concern of the business community, always interested in the production of competent workers, continued to support efforts at raising the minimum skill level of Florida high school graduates. ^ Suggestions are made for future research including the examination of local school sites in order to assess the overall nature of the school experience rather than rely upon performance indicators mandated by state policy. ^

Political strategy, leadership, and policy entrepreneurship in Japanese defense policy and politics: A comparison of three prime ministerships

Since the end of the Cold War, Japan's defense policy and politics has gone through significant changes. Throughout the post cold war period, US-Japan alliance managers, politicians with differing visions and preferences, scholars, think tanks, and the actions of foreign governments have all played significant roles in influencing these changes. Along with these actors, the Japanese prime minister has played an important, if sometimes subtle, role in the realm of defense policy and politics. Japanese prime ministers, though significantly weaker than many heads of state, nevertheless play an important role in policy by empowering different actors (bureaucratic actors, independent commissions, or civil actors), through personal diplomacy, through agenda-setting, and through symbolic acts of state. The power of the prime minister to influence policy processes, however, has frequently varied by prime minister. My dissertation investigates how different political strategies and entrepreneurial insights by the prime minister have influenced defense policy and politics since the end of the Cold War. In addition, it seeks to explain how the quality of political strategy and entrepreneurial insight employed by different prime ministers was important in the success of different approaches to defense. My dissertation employs a comparative case study approach to examine how different prime ministerial strategies have mattered in the realm of Japanese defense policy and politics. Three prime ministers have been chosen: Prime Minister Hashimoto Ryutaro (1996-1998); Prime Minister Koizumi Junichiro (2001-2006); and Prime Minister Hatoyama Yukio (2009-2010). These prime ministers have been chosen to provide maximum contrast on issues of policy preference, cabinet management, choice of partners, and overall strategy. As my dissertation finds, the quality of political strategy has been an important aspect of Japan's defense transformation. Successful strategies have frequently used the knowledge and accumulated personal networks of bureaucrats, supplemented bureaucratic initiatives with top-down personal diplomacy, and used a revitalized US-Japan strategic relationship as a political resource for a stronger prime ministership. Though alternative approaches, such as those that have looked to displace the influence of bureaucrats and the US in defense policy, have been less successful, this dissertation also finds theoretical evidence that alternatives may exist.