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Full-Text Articles in Life Sciences

Physiological Performance Measures And Tolerance Limits Of Estuarine Indicator Species In South Florida, Pamela Marie Bachman Nov 2009

Physiological Performance Measures And Tolerance Limits Of Estuarine Indicator Species In South Florida, Pamela Marie Bachman

FIU Electronic Theses and Dissertations

Current water management practices in South Florida have negatively impacted many species inhabiting Florida Bay. Variable and high salinity has been identified as a key stressor in these estuaries. The comprehensive Everglades Restoration Plan (CERP) includes water redistribution projects that will restore natural freshwater flows to northeastern Florida Bay. My studies focused on the following central theme and hypotheses: Biological performance measures (i.e., growth, reproduction, survival), behavior (i.e., habitat preference and locomotor behavior) and diversity of estuarine fish will be controlled by changes in salinity and water quality that will occur as a result of the restoration of freshwater flow …


Seed Dispersal And Reproduction Patterns Among Everglades Plants, Ronald E. Mossman Nov 2009

Seed Dispersal And Reproduction Patterns Among Everglades Plants, Ronald E. Mossman

FIU Electronic Theses and Dissertations

In this study three aspects of sexual reproduction in Everglades plants were examined to more clearly understand seed dispersal and the allocation of resources to sexual reproduction— spatial dispersal process, temporal dispersal of seeds (seedbank), and germination patterns in the dominant species, sawgrass (Cladium jamaicense). Community assembly rules for fruit dispersal were deduced by analysis of functional traits associated with this process. Seedbank ecology was investigated by monitoring emergence of germinants from sawgrass soil samples held under varying water depths to determine the fate of dispersed seeds. Fine-scale study of sawgrass fruits yielded information on contributions to variation in sexually …


Interactions Between Endothelin Receptor B And Transcription Factors Sox10 And Pax3 In The Melanocyte Lineage, Marcia Lowenstein Nov 2009

Interactions Between Endothelin Receptor B And Transcription Factors Sox10 And Pax3 In The Melanocyte Lineage, Marcia Lowenstein

FIU Electronic Theses and Dissertations

Genetic interactions that underlie developmental processes such as cell differentiation and pattern formation are complex and difficult to elucidate. Neural Crest (NC) cells and their derivatives offer an optimal system in which to probe for these complex interactions as they acquire different cell fates and constitute a variety of structures. The transcription factors Sox10 and Pax3 as well as the transmembrane receptor Endothelin receptor b (Ednrb) are temporally and spatially co-expressed early in NC cells and mutations in these genes lead to similar hypopigmentation phenotypes due to a reduced number of NC-derived melanocyte precursors, the melanoblasts. The goal of this …


Absolute Configuration And Biosynthesis Of Pahayokolide A From Lyngbya Sp. Strain 15-2 Of The Florida Everglades, Li Liu Nov 2009

Absolute Configuration And Biosynthesis Of Pahayokolide A From Lyngbya Sp. Strain 15-2 Of The Florida Everglades, Li Liu

FIU Electronic Theses and Dissertations

Pahayokolides A-D are cytotoxic cyclic polypeptides produced by the freshwater cyanobacterium Lyngbya sp. strain 15-2 that possess an unusual β-amino acid, 3-amino-2,5,7,8-tetrahydroxy-10-methylundecanoic acid (Athmu). The absolute configuration of pahayokolides A-D was determined using advanced Marfey’s method. It was also confirmed that a pendant N-acetyl-N-methyl leucine moiety in pahayokolide A was absent in pahayokolides B and pahayokolides C-D were conformers of pahayokolide A. Feeding experiments indicated that the biosynthesis of the Athmu sidechain arises from leucine or α-ketoisovalerate, however could not be further extended by three rounds of condensation with malonate units. Putative four peptide and one unique polyketide synthetases in …


The Effect Of Male-Male Competition And Its Underlying Regulatory Mechanisms On The Electric Signal Of The Gymnotiform Fish Brachyhypopomus Gauderio, Vielka Lineth Salazar Oct 2009

The Effect Of Male-Male Competition And Its Underlying Regulatory Mechanisms On The Electric Signal Of The Gymnotiform Fish Brachyhypopomus Gauderio, Vielka Lineth Salazar

FIU Electronic Theses and Dissertations

Sexually-selected communication signals can be used by competing males to settle contests without incurring the costs of fighting. The ability to dynamically regulate the signal in a context-dependent manner can further minimize the costs of male aggressive interactions. Such is the case in the gymnotiform fish Brachyhypopomus gauderio, which, by coupling its electric organ discharge (EOD) waveform to endocrine systems with circadian, seasonal, and behavioral drivers, can regulate its signal to derive the greatest reproductive benefit. My dissertation research examined the functional role of the EOD plasticity observed in male B. gauderio and the physiological mechanisms that regulate the enhanced …


The Use Of Hyphenated Spectrometric Techniques For The Environmental Forensic Assessment Of Non-Traditional Pollutants And Degradates In The Greater Florida Everglades, Luis E. Arroyo-Mora Feb 2009

The Use Of Hyphenated Spectrometric Techniques For The Environmental Forensic Assessment Of Non-Traditional Pollutants And Degradates In The Greater Florida Everglades, Luis E. Arroyo-Mora

FIU Electronic Theses and Dissertations

A comprehensive investigation of sensitive ecosystems in South Florida with the main goal of determining the identity, spatial distribution, and sources of both organic biocides and trace elements in different environmental compartments is reported. This study presents the development and validation of a fractionation and isolation method of twelve polar acidic herbicides commonly applied in the vicinity of the study areas, including e.g. 2,4-D, MCPA, dichlorprop, mecroprop, picloram in surface water. Solid phase extraction (SPE) was used to isolate the analytes from abiotic matrices containing large amounts of dissolved organic material. Atmospheric-pressure ionization (API) with electrospray ionization in negative mode …