Women of African descent: Persistence in completing doctorates

This study examines the educational persistence of women of African descent (WOAD) in pursuit of a doctorate degree at universities in the southeastern United States. WOAD are women of African ancestry born outside the African continent. These women are heirs to an inner dogged determination and spirit to survive despite all odds (Pulliam, 2003, p. 337).This study used Ellis’s (1997) Three Stages for Graduate Student Development as the conceptual framework to examine the persistent strategies used by these women to persist to the completion of their studies. Semi-structured interviews were conducted, transcribed, and analyzed for the 10 study participants. The study examined their beliefs, roles, and support systems utilized during their studies to help propel them to succeed. Interview data were analyzed using cross-case analysis to discover emerging themes and patterns. A comparative analysis was used to analyze the participants’ experiences and discover themes and patterns to review against the historical data. The findings showed that WOAD experienced feelings of isolation, neglect and racial prejudice as doctoral students. Their ability to formulate supportive relationships among each other and in their communities outside the university was key to their persistence to graduation. There still remains a need to create a more engaging and inclusive environment for nontraditional students, particularly those who are WOAD. The study concludes with six strategies of success used by these WOAD to persist to completion. Those six strategies include 1. Keeping the goal of earning a doctorate and graduating foremost on your mind. 2. Set a class and study schedule that allows you to balance family, work and study. 3. Take care of yourself, physically, mentally and emotionally. 4. Keep a goal chart to track your strides toward completion/graduation. 5. Establish a strong support system among your family, friends, colleagues and community; and 6. Do not let the “isms” (racism, sexism, and ageism) deter you.

Students of Haitian Descent in American Schools: Challenges and Issues

This paper examines the ways the reception of students of Haitian descent in this country has shaped their educational careers. Additionally, this paper explores the racial, cultural, and individual differences that need to be understood in order to help educators, parents, and students make their schooling a positive experience.

Expression of the Myod and T-Box Families of Transcription Factors in the Developing Purkinje Fiber

The coordinated beating of the heart depends on a group ofhighly specialized cells that constitute the cardiac conduction system. Among these cells, the Purkinje fibers are responsible for propagation of the electric impulse into the ventricles. In early stages of development, Purkinje fibers and skeletal muscle fibers originate from similar but separate populations of myocytes. The role of the MyoD family of transcription factors in the development of the myotube is well known, but the role of these factors in the development of the Purkinje fiber is not. Members of the T-Box family of transcription.The coordinated beating of the heart depends on a group ofhighly specialized cells that constitute the cardiac conduction system. Among these cells, the Purkinje fibers are responsible for propagation of the electric impulse into the ventricles. In early stages of development, Purkinje fibers and skeletal muscle fibers originate from similar but separate populations of myocytes. The role of the MyoD family of transcription factors in the development of the myotube is well known, but the role of these factors in the development of the Purkinje fiber is not. Members of the T-Box family of transcription factors are also involved in the development of various cardiac tissues, including the conduction system but little is known about their role in the development of the Purkinje fiber. We explored the expression of members of the MyoD and T-Box families in the developing cardiac conduction system in vivo and in vitro. We showed that the expression of these factors changes as the myocyte differentiates into the Purkinje fiber. We also showed that NRG-1, a secreted protein involved in the development of the Purkinje fiber, features a dose-dependent response in the differentiation of cultured ventricular myocytes.

Substructuring in four populations of African descent

When a suspect's DNA profile is admitted into court as a match to evidence the probability of the perpetrator being another individual must be calculated from database allele frequencies. The two methods used for this calculation are phenotypic frequency and likelihood ratio. Neither of these calculations takes into account substructuring within populations. In these substructured populations the frequency of homozygotes increases and that of heterozygotes usually decreases. The departure from Hardy- Weinberg expectation in a sample population can be estimated using Sewall Wright's Fst statistic. Fst values were calculated in four populations of African descent by comparing allele frequencies at three short tandem repeat loci. This was done by amplifying the three loci in each sample using the Polymerase Chain Reaction and separating these fragments using polyacrylamide gel electrophoresis. The gels were then silver stained and autoradiograms taken, from which allele frequencies were estimated. Fst values averaged 0.007+- 0.005 within populations of African descent and 0.02+- 0.01 between white and black populations.

An automated method for the determination of electroreception thresholds in weakly electric fish

Weakly electric fish produce a dual function electric signal that makes them ideal models for the study of sensory computation and signal evolution. This signal, the electric organ discharge (EOD), is used for communication and navigation. In some families of gymnotiform electric fish, the EOD is a dynamic signal that increases in amplitude during social interactions. Amplitude increase could facilitate communication by increasing the likelihood of being sensed by others or by impressing prospective mates or rivals. Conversely, by increasing its signal amplitude a fish might increase its sensitivity to objects by lowering its electrolocation detection threshold. To determine how EOD modulations elicited in the social context affect electrolocation, I developed an automated and fast method for measuring electroreception thresholds using a classical conditioning paradigm. This method employs a moving shelter tube, which these fish occupy at rest during the day, paired with an electrical stimulus. A custom built and programmed robotic system presents the electrical stimulus to the fish, slides the shelter tube requiring them to follow, and records video of their movements. I trained the electric fish of the genus Sternopygus was trained to respond to a resistive stimulus on this apparatus in 2 days. The motion detection algorithm correctly identifies the responses 91% of the time, with a false positive rate of only 4%. This system allows for a large number of trials, decreasing the amount of time needed to determine behavioral electroreception thresholds. This novel method enables the evaluation the evolutionary interplay between two conflicting sensory forces, social communication and navigation.

The use of the Dade County student assistance profile in the identification of at -risk students at a minority senior high school

Current high school completion rates in Dade County and across the nation are considered to be unacceptable. This has led to the development of student assistance profiles to aid in the early identification of students considered to be at risk to allow for some form of intervention. The purpose of this research was to examine the current Dade County Public Schools profile as applied to one specific high school in which most of the students are Hispanic (mostly of Mexican descent) and Black (African-Americans, as well as recent Haitian immigrants). Additionally, the effectiveness of the alternative intervention program provided at this high school--a school within a school--were evaluated. School records of the 1992 in-coming ninth grade class became the initial data base. The individual student records of this cohort were then examined over a four-year period until their expected date or graduation. The DCPS profile used to identify potential dropouts from this group was evaluated, using chi-square and multivariate analysis, to determine its overall effectiveness, as well as the effectiveness of the individual indicators which comprise the profile. The Student Assistance Profile was found to an effective predictor, but it over-identified students from this cohort, particularly minorities, to the extent that it became largely ineffective, especially considering the limited resources available for intervention. The intervention program was found to be ineffective in reducing the dropout rate. Further analysis of the individual indicators used in the DCPS profile as they applied to this school population resulted in the development of an improved profile. By reducing the number of indicators to those found to be most highly associated with failure to graduate--academic performance and absences--a simpler student assistance profile was developed which appears to be better suited to high schools with similar demographics and budget restraints. ^

Novel analytical methodologies for the monitoring of traditional and non-traditional pollutants in different environmental compartments of South Florida

Routine monitoring of environmental pollution demands simplicity and speed without sacrificing sensitivity or accuracy. The development and application of sensitive, fast and easy to implement analytical methodologies for detecting emerging and traditional water and airborne contaminants in South Florida is presented. A novel method was developed for quantification of the herbicide glyphosate based on lyophilization followed by derivatization and simultaneous detection by fluorescence and mass spectrometry. Samples were analyzed from water canals that will hydrate estuarine wetlands of Biscayne National Park, detecting inputs of glyphosate from both aquatic usage and agricultural runoff from farms. A second study describes a set of fast, automated LC-MS/MS protocols for the analysis of dioctyl sulfosuccinate (DOSS) and 2-butoxyethanol, two components of Corexit®. Around 1.8 million gallons of those dispersant formulations were used in the response efforts for the Gulf of Mexico oil spill in 2010. The methods presented here allow the trace-level detection of these compounds in seawater, crude oil and commercial dispersants formulations. In addition, two methodologies were developed for the analysis of well-known pollutants, namely Polycyclic Aromatic Hydrocarbons (PAHs) and airborne particulate matter (APM). PAHs are ubiquitous environmental contaminants and some are potent carcinogens. Traditional GC-MS analysis is labor-intensive and consumes large amounts of toxic solvents. My study provides an alternative automated SPE-LC-APPI-MS/MS analysis with minimal sample preparation and a lower solvent consumption. The system can inject, extract, clean, separate and detect 28 PAHs and 15 families of alkylated PAHs in 28 minutes. The methodology was tested with environmental samples from Miami. Airborne Particulate Matter is a mixture of particles of chemical and biological origin. Assessment of its elemental composition is critical for the protection of sensitive ecosystems and public health. The APM collected from Port Everglades between 2005 and 2010 was analyzed by ICP-MS after acid digestion of filters. The most abundant elements were Fe and Al, followed by Cu, V and Zn. Enrichment factors show that hazardous elements (Cd, Pb, As, Co, Ni and Cr) are introduced by anthropogenic activities. Data suggest that the major sources of APM were an electricity plant, road dust, industrial emissions and marine vessels.

Environmental analysis of polar herbicides in complex organic-rich matrices by high performance liquid chromatography atmospheric pressure ionization mass spectrometry (HPLC-API-MS)

A comprehensive forensic investigation of sensitive ecosystems in the Everglades Area is presented. Assessing the background levels of contamination in these ecosystems represents a vital resource to build up forensic evidence required to enforce future environmental crimes within the studied areas. This investigation presents the development and validation of a fractionation and isolation method for two families of herbicides commonly applied in the vicinity of the study area, including phenoxy acids like 2,4-D, MCPA, and silvex; as well as the most common triazine-based herbicides like atrazine, prometyne, simazine and related metabolites like DIA and DEA. Accelerated solvent extraction (ASE) and solid phase extraction (SPE) were used to isolate the analytes from abiotic matrices containing large amounts of organic material. Atmospheric-pressure ionization (API) with electrospray ionization in negative mode (ESP-), and Chemical Ionization in the positive mode (APCI+) were used to perform the characterization of the herbicides of interest.

What are the effects of the 6 +1 Writing Traits on the Attitudes and Writing Skills of Fifth Grade ELLs?

In the Bahamas, ELLs consist mainly of Haitian descent students. Unfortunately, this demographic of students continuously score below their Bahamian counterparts in Creative Writing. This research examined the affects the 6 + 1 Writing Traits assessment had on the attitudes and writing abilities of fifteen, fifth grade, Haitian descent students.

Cultural identity in landscape architecture, renovation of Managua's lakeside

This thesis examines a design approach in landscape architecture in which cultural and historical values are reinterpreted in a contemporary urban environment. The site of this project is located in Managua's lakeside area, which was destroyed by hurricane Mitch in 1998. The lakeside area has been an attraction to Managua's residents because of its beautiful views and fresh breezes. The majority of Nicaragua's population is of indigenous descent; however, Managua's urban environment is predominantly of European influence. The pre-Columbian heritage of Nicaraguans is hidden in their cultural expressions, such as the names of places and religious rituals. This project provides a new lakeside area for Managua in which cultural identity in landscape architecture is represented in the use of the site and in a rescue of Managua's residents' pride in their pre-Columbian heritage. The lakeside renovation was planned using pre-Columbian design methodology and vocabulary to create a functional and environmentally sens~velandscape.

Novel Analytical Methodologies for the Monitoring of Traditional and Non-traditional Pollutants in different Environmental Compartments of South Florida

Routine monitoring of environmental pollution demands simplicity and speed without sacrificing sensitivity or accuracy. The development and application of sensitive, fast and easy to implement analytical methodologies for detecting emerging and traditional water and airborne contaminants in South Florida is presented. A novel method was developed for quantification of the herbicide glyphosate based on lyophilization followed by derivatization and simultaneous detection by fluorescence and mass spectrometry. Samples were analyzed from water canals that will hydrate estuarine wetlands of Biscayne National Park, detecting inputs of glyphosate from both aquatic usage and agricultural runoff from farms. A second study describes a set of fast, automated LC-MS/MS protocols for the analysis of dioctyl sulfosuccinate (DOSS) and 2-butoxyethanol, two components of Corexit®. Around 1.8 million gallons of those dispersant formulations were used in the response efforts for the Gulf of Mexico oil spill in 2010. The methods presented here allow the trace-level detection of these compounds in seawater, crude oil and commercial dispersants formulations. In addition, two methodologies were developed for the analysis of well-known pollutants, namely Polycyclic Aromatic Hydrocarbons (PAHs) and airborne particulate matter (APM). PAHs are ubiquitous environmental contaminants and some are potent carcinogens. Traditional GC-MS analysis is labor-intensive and consumes large amounts of toxic solvents. My study provides an alternative automated SPE-LC-APPI-MS/MS analysis with minimal sample preparation and a lower solvent consumption. The system can inject, extract, clean, separate and detect 28 PAHs and 15 families of alkylated PAHs in 28 minutes. The methodology was tested with environmental samples from Miami. Airborne Particulate Matter is a mixture of particles of chemical and biological origin. Assessment of its elemental composition is critical for the protection of sensitive ecosystems and public health. The APM collected from Port Everglades between 2005 and 2010 was analyzed by ICP-MS after acid digestion of filters. The most abundant elements were Fe and Al, followed by Cu, V and Zn. Enrichment factors show that hazardous elements (Cd, Pb, As, Co, Ni and Cr) are introduced by anthropogenic activities. Data suggest that the major sources of APM were an electricity plant, road dust, industrial emissions and marine vessels.