Life Sciences Commons^™

Cytotoxicity And Drug Potentiating Activity Of Phenylheptatriyne, Rachel Arrasmith Gray

FIU Electronic Theses and Dissertations

The purpose of this study was to determine the toxicity of the phototoxin, phenylheptatriyne (PHT) to acute lymphoblastic leukemia cells (ALL) under attenuated light conditions and when exposed to ultraviolet-A light (UVA). The potential of PHT to increase sensitivity of ALL cells to the anti-cancer drug doxorubicin hydrochloride also was evaluated. An in vitro multi-drug resistance model was used consisting of the parental cell line CCRF-CEM and its p-glycoprotein (pgp-170) expressing variant CEM/VLB₁₀₀. Cytotoxicity was measured using the tetrazolium bromide (MTT) reduction assay and the annexin-V-FITC / propidium iodide (PI), flow cytometric assay. The results indicate …

Genetic Variation Among Cultivated Selections Of Mamey Sapote (Pouteria Spp. [Sapotaceae]), Susan Carrara

FIU Electronic Theses and Dissertations

Mamey sapote [Pouteria spp., Sapotaceae] is a tree fruit of economic and cultural importance in Central America, Mexico, and the Caribbean islands. It contributes greatly to local economies, habitats, and human nutrition. This study is among the first to analyze genetic variability among cultivated selections of mamey sapote. The Amplified Fragment Length Polymorphism (AFLP) molecular technique was used to estimate levels of genetic diversity and similarity between individual specimens in the germplasm collections of Fairchild Tropical Botanic Garden and University of Florida. The study found overall low levels of genetic diversity within these collections. However, higher relative levels of …

Vertical Attenuation Of Light Predicts The Sequence To Dawn Song In A Tropical Forest Avifuana, Karl Stephen Berg

FIU Electronic Theses and Dissertations

The concentration of avian song at first light (i.e., the dawn chorus) is widely appreciated but has an enigmatic functional significance. The most widely accepted explanation is that birds are active but light levels are not adequate for foraging. As a consequence, the time of first song should be predictable from the light level of individuals singing at dawn. To test this, I collected data from a tropical forest of Ecuador, involving 130 species. Light intensity at first song was a highly repeatable species' trait (r = 0.57). Foraging height was a good predictor of first song, with canopy birds …

Linking Herbivory And Pollination : Costs And Selection Implications In Centrosema Virginianum Bentham (Fabaceae: Papilionoideae), Yuria Cardel

FIU Electronic Theses and Dissertations

This research first evaluated levels and type of herbivory experienced by Centrosema virginianum plants in their native habitat and how florivory affected the pollinator activity. I found that populations of C. virginianum in two pine rockland habitat fragments experienced higher herbivory levels (15% and 22%) compared with plants in the protected study site (8.6%). I found that bees (Hymenoptera) pollinated butterfly pea. Furthermore, I found that florivores had a negative effect in the pollinators visitation rates and therefore in the seed set of the population.

I then conducted a study using a greenhouse population of C. virginianum. I applied …