The Role of Recharge and Evapotranspiration as Hydraulic Drivers of Ion Concentrations in Shallow Groundwater on Everglades Tree Islands, Florida (USA)

Recently, evapotranspiration has been hypothesized to promote the secondary formation of calcium carbonate year-round on tree islands in the Everglades by influencing groundwater ions concentrations. However, the role of recharge and evapotranspiration as drivers of shallow groundwater ion accumulation has not been investigated. The goal of this study is to develop a hydrologic model that predicts the chloride concentrations of shallow tree island groundwater and to determine the influence of overlying biomass and underlying geologic material on these concentrations. Groundwater and surface water levels and chloride concentrations were monitored on eight constructed tree islands at the Loxahatchee Impoundment Landscape Assessment (LILA) from 2007 to 2010. The tree islands at LILA were constructed predominately of peat, or of peat and limestone, and were planted with saplings of native tree species in 2006 and 2007. The model predicted low shallow groundwater chloride concentrations when inputs of regional groundwater and evapotranspiration-to-recharge rates were elevated, while low evapotranspiration-to-recharge rates resulted in a substantial increase of the chloride concentrations of the shallow groundwater. Modeling results indicated that evapotranspiration typically exceeded recharge on the older tree islands and those with a limestone lithology, which resulted in greater inputs of regional groundwater. A sensitivity analysis indicated the shallow groundwater chloride concentrations were most sensitive to alterations in specific yield during the wet season and hydraulic conductivity in the dry season. In conclusion, the inputs of rainfall, underlying hydrologic properties of tree islands sediments and forest structure may explain the variation in ion concentration seen across Everglades tree islands.

Seasonal Fish Dispersal in Ephemeral Wetlands of the Florida Everglades

We hypothesized that fishes in short-hydroperiod wetlands display pulses in activity tied to seasonal flooding and drying, with relatively low activity during intervening periods. To evaluate this hypothesis, sampling devices that funnel fish into traps (drift fences) were used to investigate fish movement across the Everglades, U.S.A. Samples were collected at six sites in the Rocky Glades, a seasonally flooded karstic habitat located on the southeastern edge of the Everglades. Four species that display distinct recovery patterns following drought in long-hydroperiod wetlands were studied: eastern mosquitofish (Gambusia holbrooki) and flagfish (Jordanella floridae) (rapid recovery); and bluefin killifish (Lucania goodei) and least killifish (Heterandria formosa) (slow recovery). Consistent with our hypothesized conceptual model, fishes increased movement soon after flooding (immigration period) and just before drying (emigration period), but decreased activity in the intervening foraging period. We also found that eastern mosquitofish and flagfish arrived earlier and showed stronger responses to hydrological variation than either least killifish or bluefin killifish. We concluded that these fishes actively colonize and escape ephemeral wetlands in response to flooding and drying, and display species-specific differences related to flooding and drying that reflect differences in dispersal ability. These results have important implications for Everglades fish metacommunity dynamics.

Socio-ecological vulnerability to climate change in South Florida

Awareness of extreme high tide flooding in coastal communities has been increasing in recent years, reflecting growing concern over accelerated sea level rise. As a low-lying, urban coastal community with high value real estate, Miami often tops the rankings of cities worldwide in terms of vulnerability to sea level rise. Understanding perceptions of these changes and how communities are dealing with the impacts reveals much about vulnerability to climate change and the challenges of adaptation. ^ This empirical study uses an innovative mixed-methods approach that combines ethnographic observations of high tide flooding, qualitative interviews and analysis of tidal data to reveal coping strategies used by residents and businesses as well as perceptions of sea level rise and climate change, and to assess the relationship between measurable sea levels and perceptions of flooding. I conduct a case study of Miami Beach's storm water master planning process which included sea level rise projections, one of the first in the nation to do so, that reveals the different and sometimes competing logics of planners, public officials, activists, residents and business interests with regards to climate change adaptation. By taking a deeply contextual account of hazards and adaptation efforts in a local area I demonstrate how this approach can be effective at shedding light on some of the challenges posed by anthropogenic climate change and accelerated rates of sea level rise. ^ The findings highlight challenges for infrastructure planning in low-lying, urban coastal areas, and for individual risk assessment in the context of rapidly evolving discourse about the threat of sea level rise. Recognition of the trade-offs and limits of incremental adaptation strategies point to transformative approaches, at the same time highlighting equity concerns in adaptation governance and planning. This new impact assessment method contributes to the integration of social and physical science approaches to climate change, resulting in improved understanding of socio-ecological vulnerability to environmental change.^

Investigation of escape and negative student behaviors related to Florida state high stakes test preparation in Miami-Dade County Public High Schools

The purpose of this study was to determine whether there was a relationship between pressure to perform on state mandated, high-stakes tests and the rate of student escape behavior defined as the number of school suspensions and absences. The state assigned grade of a school was used as a surrogate measure of pressure with the assumption that pressure increased as the school grade decreased. Student attendance and suspension data were gathered from all 33 of the regular public high schools in Miami-Dade County Public Schools. The research questions were: Is the number of suspensions highest in the third quarter, when most FCAT preparation takes place for each of the 3 school years 2007-08 through 2009-10? How accurately does the high school's grade predict the number of suspensions and number of absences during each of the 4 school years 2005-06 through 2008-09? The research questions were answered using repeated measures analysis of variance for research question #1 and non-linear multiple regression for research question #2. No significant difference could be found between the numbers of suspensions in each of the grading periods nor was there a relationship between the number of suspensions and school grade. A statistically significant relationship was found between student attendance and school grade. When plotted, this relationship was found to be quadratic in nature and formed a loose inverted U for each of the four years during which data were collected. This indicated that students in very high and very low performing schools had low levels of absences while those in the midlevel of the distribution of school performance (C schools) had the greatest rates of absence. Identifying a relationship between the pressures associated with high stakes testing and student escape behavior suggests that it might be useful for building administrators to reevaluate test preparation activities and procedures being used in their building and to include anxiety reducing strategies. As a relationship was found, it sets the foundation for future studies to identify whether testing related activities are impacting some students emotionally and are causing unintended consequences of testing mandates.

Syndemic health disparities and resilience processes related to HIV transmission risk among African American/Black men in south Florida

Rates of HIV infection continue to climb among minority populations and men who have sex with men (MSM), with African American/Black MSM being especially impacted. Numerous studies have found HIV transmission risk to be associated with many health and social disparities resulting from larger environmental and structural forces. Using anthropological and social environment-based theories of resilience that focus on individual agency and larger social and environmental structures, this dissertation employed a mixed methods design to investigate resilience processes among African American/Black MSM.^ Quantitative analyses compared African American/Black (N=108) and Caucasian/White (N=250) MSM who participated in a previously conducted randomized controlled trial (RCT) of sexual and substance use risk reduction interventions. At RCT study entry, using past 90 day recall periods, there were no differences in unprotected sex frequency, however African American/Black MSM reported higher frequencies of days high (P<0.000), and drugs and sex used in combination (P<0.000), and substance dependence (P<0.000) and lower levels of social support (P<0.024) compared to Caucasian/White MSM. At 12- month follow-up, multi-level statistical models found that African American/Black MSM reduced their frequencies of days high and unprotected sex at greater rates than Caucasian/White MSM (P<0.001).^ Qualitative data collected among a sub-sample of African American/Black MSM from the RCT (N=21) described the men's experiences of living with multiple health and social disparities and the importance of RCT study assessments in facilitating reductions in risk behaviors. A cross-case analysis showed different resilience processes undertaken by men who experienced low socioeconomic status, little family support, and homophobia (N=16) compared to those who did not (N=5).^ The dissertation concludes that resilience processes to HIV transmission risk and related health and social disparities among African American/Black MSM varies and are dependent on specific social environmental factors, including social relationships, structural homophobia, and access to social, economic, and cultural capital. Men define for themselves what it means to be resilient within their social environment. These conclusions suggest that both individual and structural-level resilience-based HIV prevention interventions are needed.^

FIU Little Caesars Pizza Bowl Celebration

Function held at Graham Center Ballrooms to celebrate the victory of FIU's Golden Panther Football Team in the Little Caesar's Pizza Bowl. Event held on January 28,2011 and sponsored by the Student Government Association.

Using stable isotopes to investigate trophic interactions of bottlenose dolphins (Tursiops truncatus) in the Florida Coastal Everglades

Top predators are known for their ability to 1) affect their communities through predation and 2) induce behavioral modifications. Recent research suggests that they may also play “bottom-up” roles in ecosystems, including transporting materials within and across habitat boundaries. The Florida Coastal Everglades (FCE) is an “upside-down” oligotrophic estuary where productivity decreases from the mouth of the estuary to freshwater marshes. Therefore, movements of predators may be important in ecosystem dynamics. While other estuarine predators in the FCE have been shown to potentially move nutrients among ecosystems, the potential for bottlenose dolphins (Tursiops truncatus) to play a similar role in the systems has not been investigated. Stable isotope analysis of biopsy samples were used to investigate spatial variation in trophic interactions of dolphins to see if they might transport nutrients. Values of δ15 N suggest dolphins feed at a trophic level similar to other top predators in the ecosystem while δ13 C suggest that dolphins forage largely within food webs where they were sampled rather than transporting nutrients across ecosystem boundaries. The exception may be dolphins foraging in rivers, which may transport nutrients downstream; a pattern opposite to that of bull sharks and alligators in these habitats. Further research is necessary to predict how future changes occurring due to restoration and climate will affect the ecological roles of dolphins.

Federal Priorities: Investing in South Florida's Innovative Solutions Center

This report provides details about FIU's federally funded activities.

Investigating the Outcomes of a Physical Activity Program offered to Older Adults in South Florida and Understanding the Correlates of Completion

Despite the well-known benefits of physical activity, in 2012, only 37.5% of older adults aged 60 years or older met recommended aerobic physical activity levels and 16.1% met muscle-strengthening guidelines. Effective exercise programs can help combat the problem of inactivity but 50% of those who start participating in an exercise program drop out within first few weeks, preventing them from gaining any health benefits. Since fall 2008, the Healthy Aging Regional Collaborative of South Florida has offered EnhanceFitness (EF), an evidence-based physical activity program to older adults. This dissertation compared EF effectiveness at 4-, 8-, and 12-months and examined the factors that were associated with program completion. A paired sample t-test identified changes at 4-months and repeated measures design was used to identify changes from baseline to 4-, 8-, and 12- months. Logistic regression was used to identify correlates associated with completion. Between October 1, 2008 and December 31, 2012, 4,531 older adults (>=60 years) attended one or more EF sessions. Participants showed significant improvement in the number of chair stands performed in 30-seconds with mean change of 1.7, 1.6, and 2.0 respectively at 4-,8-,and 12- months (pp<0.001). Results suggest Black, non-Haitian men were less likely to complete the program when compared to white, non-Hispanic men (OR=0.41, p=0.02). Men who self-reported having at least one risk factor were more likely to complete the program (OR=1.81, p= 0.03). In addition, women who lived in Miami-Dade County (OR=2.13, ppppp<0.01). Effectiveness results revealed that all participants improved on outcome measures. However, improvement is more than double for those who completed recommended sessions (p

Can minority language proficiency pay: a study on the return on English-Spanish fluent bilingualism in South Florida

This thesis studies the economic return for fluent-bilingualism in South Florida among native-born whites using IPUMS (Integrated Public Use Microdata Series) data for Miami-Dade County (1990). Previous mainstream-oriented theories focus on the benefit in English acquisition for immigrants and their descendants, either denying or ignoring the possible benefit of minority language retention in addition to English acquisition. An alternative literature, on the other hand, suggests that minority language retention can be beneficial in at least three areas: 1) enhancing cognitive ability; 2) accessing community-level social capital; and 3) serving as human capital. This study assesses economic returns in employment and earnings, using logistic and OLS (Ordinary Least Square) regression respectively. The results, countering the mainstream-oriented theories, suggest that fluent bilingualism does have economic consequences. Rather than fully supporting the positive effects thesis, the patterns shown are much more complicated, contingent on an individual's ethnic membership and educational level. Theoretical and substantive implications are discussed and suggestions for future research are made.

Infant feeding practices of Cuban mothers residing in Dade County, Florida

Research has shown that infant feeding practices differ between cultures. A convenience sample of 51 first generation Cuban mothers with infants birth to 12 months of age were surveyed to identify their infant feeding practices, and why they introduce foods to their infants in the manner in which they do. Data obtained from the mothers' responses to an English/Spanish Questionnaire were summarized by frequencies. Findings revealed that Cuban mothers consider a variety of foods from the major four food groups to be suitable for their infants. They introduced solids to their infants at the average age of four months and fed their infants in the manner in which they did because they thought it was healthy/nutritious. Cuban mothers may feed their infants as taught by health care professionals if their infant feeding practices are incorporated in the culture specific infant feeding programmes developed by the health team.

Development and evaluation of a geographic information system based method to estimate flooding susceptibility in an area of Broward County, Florida

The objective of this study was to develop a GIS-based multi-class index overlay model to determine areas susceptible to inland flooding during extreme precipitation events in Broward County, Florida. Data layers used in the method include Airborne Laser Terrain Mapper (ALTM) elevation data, excess precipitation depth determined through performing a Soil Conservation Service (SCS) Curve Number (CN) analysis, and the slope of the terrain. The method includes a calibration procedure that uses "weights and scores" criteria obtained from Hurricane Irene (1999) records, a reported 100-year precipitation event, Doppler radar data and documented flooding locations. Results are displayed in maps of Eastern Broward County depicting types of flooding scenarios for a 100-year, 24-hour storm based on the soil saturation conditions. As expected the results of the multi-class index overlay analysis showed that an increase for the potential of inland flooding could be expected when a higher antecedent moisture condition is experienced. The proposed method proves to have some potential as a predictive tool for flooding susceptibility based on a relatively simple approach.

A Cultural Historical Study of Land Use in Dade County, Florida

Humans have used the land within the area currently defined as Dade County, Florida since around 11,000 B.P., but did not significantly alter the local environment until less than one hundred years ago. These recent changes greatly affected many critical ecological factors, thereby reducing the sustainability of many types of life, including humans. This study explains how land use evolved from earlier sustainable systems for satisfying human needs into the current menacing patterns. This is done by examining the environmental, technological, social, and cognitive contexts of land use through time. Changes in all these areas have followed a general trend leading to increasing intensity of land use and environmental change driven by population growth and technological innovation.