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Individual neurons in the primary visual cortex respond selectively to different features of visual stimuli, such as spatial orientation or direction of motion. A longstanding goal in systems neuroscience has been to understand the transformations single cells perform as they integrate synaptic inputs to generate spiking output. Recent technological developments have facilitated these lines of investigation by enabling direct measurement of the functional properties of single synaptic inputs to neurons in the neocortex. It remains an outstanding question as to whether the tuning of single neocortical neurons can be predicted by their excitatory synaptic inputs. Here, I show that excitatory synaptic inputs exhibit significant functional diversity with respect to orientation and direction selectivity. I show that cells can use at least two strategies to overcome this functional diversity to achieve selective responses in the face of broadly tuned excitatory input: enhancing responses to the preferred stimuli and suppressing responses to the non-preferred stimuli. In the case of orientation selectivity, synaptic inputs cluster according to orientation preference and evoke local dendritic nonlinearities, thereby enhancing somatic responses to the preferred direction. For direction selectivity, cells receive excitatory synaptic inputs tuned to the preferred and null directions, but selectively suppress inputs tuned for the null direction to enhance direction selectivity. This suppression comes from direction-tuned GABAergic interneurons that make longrange, intercolumnar projections to enhance direction selectivity. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

In this thesis, I examine the structure of developmental or remedial English education at U. S. two-year community colleges, specifically focusing on the disparities between Florida’s English for Academic Purposes (EAP), an English as a Second Language (ESL) program, and Developmental English (Dev English), a Basic Writing program. Both programs supposedly prepare disadvantaged and/or immigrant students for freshman composition, but they employ very different pedagogies. Drawing on existing research and my own experience as a student and a teacher, I present English as it is employed to assimilate and empower second-language users, investigate the role of Florida’s institution in promoting EAP over Dev English, and discuss issues of identity and the categorization of students. I close by recommending the teaching of English as a Second Language – reading, writing, and basic language skills – to all developmental students, immigrant or native, to equip them for higher learning and a competitive workforce. / Includes bibliography. / Thesis (M.A.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

The majority of HIV prevalence is found in Sub-Saharan Africa with 36.9 mil- lion living with HIV/AIDS. The cultural implications such as patient non-compliance or denial of available routine medical care can potentially cause limitations on the ef- fectiveness of detecting such virulent pathogens and manage chronic disease. The lack of access to healthcare and further socioeconomic impacts hinder the ability to ade- quately diagnose and treat infection in resource-limited settings. Intervention through diagnosis and treatment helps prevent the spread of transmission, where pre-exposure prophylaxis or active disease prevention measures are not readily available. The cur- rent gold standard for HIV detection is by molecular detection; Reverse-Transcription Polymerase Chain Reaction is widely used that employs cycles of temperature condi- tions that require a thermal cycling platform and typically laboratory space for RNA extraction separate from RT-PCR space required. Serological detection can be ad- vantageous for surveillance and screening, Lateral Flow Assays and Enzyme-Linked Immunosorbent Assay (ELISA) can detect a viral protein (antigen) or antibodies. The ELISA can require at least 12 hours of assay preparation and takes a diagnostic laboratory many resources to run. There is need to develop Point-of-Care (POC) testing that can potentially be used for decentralized testing that can leverage ex- isting technologies such as smart phone capability and routine medical or diagnostic tests with cutting edge applications leveraging micro uidics, nanotechnology and in- tegrated circuit design. Such technologies allow for automated, rapid turnaround and cost-e ective diagnosis of HIV, where these assays could potentially be read- ily deployed. It is such technology that can potentially change the way diagnostics are performed, as POC technology can be rapidly disseminated, enable decentralized testing and, is user-friendly. A novel smart phone-enabled automated magnetic bead- based platform was developed for a micro uidic ELISA for HIV-1 detection at the POC to meet this demand. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

No description available.

A dual-station high frequency Wellen Radar (WERA), transmitting at 16.045 MHz, has been deployed along the Eastern Florida Shelf (EFS). From September 2004 to June 2005, a moored acoustic Doppler current profiler (ADCP) acquired subsurface current measurements within the radar footprint along the shelf break at 86-m depth. The shallowest ADCP bin located at 14-m depth is used as a comparison for the WERA surface measurements. The RMS differences range from 0.1 to 0.3 m s super -1 between the surface and 14-m depth, with good agreement over most of the period. Regression analyses indicate slopes near unity in the north-south (v-) component and approximately 0.5 for the east-west (u-) component velocities. Following validation of the HF radar surface current measurements, an assessment of the variability and character of eddies in the region is conducted for 2006. Optimal interpolation is utilized to create a uniform 45 km by 45 km grid of surface current data consisting of 1980 points in the inshore portion of the WERA domain. The Okubo-Weiss parameter is used to identify eddies as closed regions with values greater than a threshold of 2*10 super -8 s super -1. This method reveals a total of twenty-two eddy-like features over the year 2006. Given the asymmetric shape of the eddy regions, equivalent radii are computed as an estimate of eddy size with an annual average of 2.6 km. Eddy intensity is measured by maximum relative vorticity in the eddy region with an annual average of approximately 5f, where f is the local Coriolis parameter. Translational velocities are computed from the displacement of peak Okubo-Weiss parameter. This method tends to overestimate eddy speed given the shape-changing nature of the eddy regions. Nonetheless, the average translational velocity is 0.9 m s super -1 with a standard deviation of 0.4 m s super -1. Eddy tracks indicate a unique pattern in which eddies propagate inshore during the period of July to September and offshore during October to December related to position of the FC axis. The periodicity and spatial distribution of eddy events suggest that submesoscale eddy features are "wave-like" and centered along the strong topographical gradients between 200 to 600 m. By applying this methodology to other years of HF radar data, this statement can be tested with statistical confidence. In general, this study has shown the effectiveness of the Okubo-Weiss parameter in identifying eddy regions from a background field with large, ambient vorticity.

First described by Plate (1906), Pyrodinium bahamense is a bioluminescent dinoflagellate species which forms a resting cyst as part of its life cycle.  P. bahamense forms large dense cyst beds in the flocculent layer of sediments and can remain dormant for decades before excysting and forming blooms.  The Atlantic strain has recently been discovered to produce a neurotoxin called saxitoxin.  Although saxitoxins are most commonly associated with paralytic shellfish poisoning, saxitoxin produced by P. bahamense has been implicated in a number of human illnesses following the consumption of contaminated puffer fish originating from the Indian River Lagoon, Florida.  The discovery of P. bahamense cysts on seagrass blades during an ongoing bloom raised the question of whether manatees, whose diet is composed mainly of seagrass, could be at risk of exposure to saxitoxins.  The aim of this study was to determine whether P. bahamense cysts can be digested in the manatee gastrointestinal tract or if they would pass through intact.  There are no known methods for purifying P. bahamense cysts from the contents of the manatee gastrointestinal tract, so it was necessary to develop an appropriate protocol using cysts purified from sediments in Tampa Bay, Florida.  These methods were then to be used to test whether P. bahamense cysts added to manatee digesta break down over time, and also to test archived digesta samples for presence of cysts.  A successful method for purifying cysts from manatee digesta could not be developed during the span of this study, and so no conclusions could be drawn about the likelihood of digestion.  However, archived samples were found to contain P. bahamense cysts, confirming that manatees are ingesting them while feeding.

Thesis (M.S.)--University of West Florida, 2007. / Title from title page of source document. Document formatted into pages; contains 31 pages. Includes bibliographical references.

Thesis (Ed.D.)--University of West Florida, 2007. / Title from title page of source document. Document formatted into pages; contains 87 pages. Includes bibliographical references.

Thesis (M.S.)--Florida State University, 2003. / Advisor: Dr. Michael K. Faught, Florida State University, College of Arts and Sciences, Dept. of Anthropology. Title and description from dissertation home page (viewed Apr. 6, 2004). Includes bibliographical references.