Life Sciences Commons^™

The Effects Of Oxygen On The Electrophysiology Of Co2/H+-Chemosensitive And -Insensitive Neurons Of The Solitary Complex Of The Rat, Michael Patrick Matott

USF Tampa Graduate Theses and Dissertations

This study tested the hypothesis that decreasing the control O₂ level from 95% to 40% (5% CO₂ + 55% N₂) maintains viability in caudal solitary complex (cSC) neurons in transverse slices (~300-400ꝳ) prepared from neonatal rat (P2-22) maintained at 32-34°C. The underlying rationale is to reduce exposure to redox and nitrosative stimuli generated during several hours of exposure to 95% O₂ that produces a tissue O₂ tension throughout the slice which is in excess of 203 kPa (2.0 atmospheres absolute,ATA) oxygen. Whole cell recordings of cSC neurons maintained in 40% O₂ exhibited spontaneous …

Evaluation Of Release-05 Grace Time-Variable Gravity Coefficients Over The Ocean, D. P. Chambers, J. A. Bonin

Marine Science Faculty Publications

The latest release of GRACE (Gravity Recovery and Climate Experiment) gravity field coefficients (Release-05, or RL05) are evaluated for ocean applications. Data have been processed using the current methodology for Release-04 (RL04) coefficients, and have been compared to output from two different ocean models. Results indicate that RL05 data from the three Science Data Centers – the Center for Space Research (CSR), GeoForschungsZentrum (GFZ), and Jet Propulsion Laboratory (JPL) – are more consistent among themselves than the previous RL04 data. Moreover, the variance of residuals with the output of an ocean model is 50–60% lower for RL05 data than for …

Decadal Changes In The Aragonite And Calcite Saturation State Of The Pacific Ocean, Richard A. Feely, Christopher L. Sabine, Robert H. Byrne, Frank J. Millero, Andrew G. Dickson, Rik Wanninkhof, Akihiko Murata, Lisa A. Miller, Dana Greeley

Marine Science Faculty Publications

Based on measurements from the WOCE/JGOFS global CO₂ survey, the CLIVAR/CO₂ Repeat Hydrography Program and the Canadian Line P survey, we have observed an average decrease of 0.34% yr⁻¹ in the saturation state of surface seawater in the Pacific Ocean with respect to aragonite and calcite. The upward migrations of the aragonite and calcite saturation horizons, averaging about 1 to 2 m yr⁻¹, are the direct result of the uptake of anthropogenic CO₂ by the oceans and regional changes in circulation and biogeochemical processes. The shoaling of the saturation horizon is regionally variable, with …

Exploring Trade-Offs Between Fisheries And Conservation Of The Vaquita Porpoise (Phocoena Sinus) Using An Atlantis Ecosystem Model, Hem Nalini Morzaria-Luna, Cameron H. Ainsworth, Isaac C. Kaplan, Phillip S. Levin, Elizabeth A. Fulton

Marine Science Faculty Publications

Background: Minimizing fishery bycatch threats might involve trade-offs between maintaining viable populations and economic benefits. Understanding these trade-offs can help managers reconcile conflicting goals. An example is a set of bycatch reduction measures for the Critically Endangered vaquita porpoise (Phocoena sinus), in the Northern Gulf of California, Mexico. The vaquita is an endemic species threatened with extinction by artisanal net bycatch within its limited range; in this area fisheries are the chief source of economic productivity.

Methodology/Principal Findings: We analyze trade-offs between conservation of the vaquita and fisheries, using an end-to-end Atlantis ecosystem model for the Northern Gulf of California. …

Modelling Reef Fish Population Responses To Fisheries Restrictionsin Marine Protected Areas In The Coral Triangle, Divya Varkey, Cameron H. Ainsworth, Tony J. Pitcher

Marine Science Faculty Publications

Marine ecosystem models are used to investigate marine protected area (MPA) benefits for coral reef ecosystems located in Raja Ampat, in the heart of the Coral Triangle. Field data from an integrated and diverse research project is used to develop a spatial ecosystem model using Ecopath, Ecosim, and Ecospace modelling software. The ecological and fisheries responses of a reef ecosystem to different levels of fishing effort restrictions inside MPAs are explored. The trade-offs of allowing some fisheries to operate inside the MPAs versus designating the MPAs as no-take zones are highlighted. The results show that rapid rebuilding of reef fish …

Cell Wall Antibiotics Provoke Accumulation Of Anchored Mcherry In The Cross Wall Of Staphylococcus Aureus, Wenqi Yu, Friedrich Götz

Molecular Biosciences Faculty Publications

A fluorescence microscopy method to directly follow the localization of defined proteins in Staphylococcus was hampered by the unstable fluorescence of fluorescent proteins. Here, we constructed plasmid (pCX) encoded red fluorescence (RF) mCherry (mCh) hybrids, namely mCh-cyto (no signal peptide and no sorting sequence), mCh-sec (with signal peptide), and mCh-cw (with signal peptide and cell wall sorting sequence). The S. aureus clones targeted mCh-fusion proteins into the cytosol, the supernatant and the cell envelope respectively; in all cases mCherry exhibited bright fluorescence. In staphylococci two types of signal peptides (SP) can be distinguished: the +YSIRK motif SPlip and the −YSIRK …

Discovery Of Marinopyrrole A (Maritoclax) As A Selective Mcl-1 Antagonist That Overcomes Abt-737 Resistance By Binding To And Targeting Mcl-1 For Proteasomal Degradation*, Kenichiro Doi, Rongshi Li, Shen-Shu Sung, Hongwei Wu, Yan Liu, Wanda Manieri, Gowdahalli Krishnegowda, Andy Awwad, Alden Dewey, Xin Liu, Shantu Amin, Chunwei Cheng, Yong Qin, Ernst Schonbrunn, Gary W. Daughdrill, Thomas P. Loughran Jr., Said M. Sebti, Hong-Gang Wang

Molecular Biosciences Faculty Publications

The anti-apoptotic Bcl-2 family of proteins, including Bcl-2, Bcl-XL and Mcl-1, are well-validated drug targets for cancer treatment. Several small molecules have been designed to interfere with Bcl-2 and its fellow pro-survival family members. While ABT-737 and its orally active analog ABT-263 are the most potent and specific inhibitors to date that bind Bcl-2 and Bcl-XL with high affinity but have a much lower affinity for Mcl-1, they are not very effective as single agents in certain cancer types because of elevated levels of Mcl-1. Accordingly, compounds that specifically target Mcl-1 may overcome this resistance. In this study, we identified …

The Role Of Epigenetics In Evolution: The Extended Synthesis, Aaron W. Schrey, Christina L. Richards, Victoria Meller, Vincent Sollars, Douglas M. Ruden

Integrative Biology Faculty and Staff Publications

No abstract provided.

Epigenetic Variation May Compensate For Decreased Genetic Variation With Introductions: A Case Study Using House Sparrows (Passer Domesticus) On Two Continents, Aaron W. Schrey, Courtney A. C. Coon, Michael T. Grispo, Mohammed Awad, Titus Imboma, Earl D. Mccoy, Henry R. Mushinsky, Christina L. Richards, Lynn B. Martin

Integrative Biology Faculty and Staff Publications

Epigenetic mechanisms impact several phenotypic traits and may be important for ecology and evolution. The introduced house sparrow (Passer domesticus) exhibits extensive phenotypic variation among and within populations. We screened methylation in populations from Kenya and Florida to determine if methylation varied among populations, varied with introduction history (Kenyan invasion < 50 years old, Florida invasion ~150 years old), and could potentially compensate for decrease genetic variation with introductions. While recent literature has speculated on the importance of epigenetic effects for biological invasions, this is the first such study among wild vertebrates. Methylation was more frequent in Nairobi, and outlier loci suggest that populations may be differentiated. Methylation diversity was similar between populations, in spite of known lower genetic diversity in Nairobi, which suggests that epigenetic variation may compensate for decreased genetic diversity as a source of phenotypic variation during introduction. Our results suggest that methylation differences may be common among house sparrows, but research is needed to discern whether methylation impacts phenotypic variation.

Storm-Induced Upwelling Of High PCo2 Waters Onto The Continental Shelf Of The Western Arctic Ocean And Implications For Carbonate Mineral Saturation States, Jeremy T. Mathis, Robert S. Pickart, Robert H. Byrne, Craig L. Mcneil, G. W. Moore, Laurie W. Juranek, Xuewu Liu, Jian Ma, Regina A. Easley, Matthew M. Elliot, Jessica N. Cross, Stacey C. Reisdorph, Frank Bahr, Jamie Morison, Trina Lichendorf, Richard A. Feely

Marine Science Faculty Publications

The carbon system of the western Arctic Ocean is undergoing a rapid transition as sea ice extent and thickness decline. These processes are dynamically forcing the region, with unknown consequences for CO₂ fluxes and carbonate mineral saturation states, particularly in the coastal regions where sensitive ecosystems are already under threat from multiple stressors. In October 2011, persistent wind-driven upwelling occurred in open water along the continental shelf of the Beaufort Sea in the western Arctic Ocean. During this time, cold (<−1.2°C), salty (>32.4) halocline water—supersaturated with respect to atmospheric CO₂ (pCO₂ > 550 μatm) and undersaturated …

The Metabolic Response Of Pteropods To Acidification Reflects Natural Co2-Exposure In Oxygen Minimum Zones, A. E. Maas, K. F. Wishner, B. A. Seibel

Marine Science Faculty Publications

Shelled pteropods (Thecosomata) are a group of holoplanktonic mollusks that are believed to be especially sensitive to ocean acidification because their aragonitic shells are highly soluble. Despite this concern, there is very little known about the physiological response of these animals to conditions of elevated carbon dioxide. This study examines the oxygen consumption and ammonia excretion of five pteropod species, collected from tropical regions of the Pacific Ocean, to elevated levels of carbon dioxide (0.10%, 1000 ppm). Our results show that pteropods that naturally migrate into oxygen minimum zones, such as Hyalocylis striata, Clio pyramidata, Cavolinia longirostris and Creseis virgula …

Direct Measurement Of Riverine Particulate Organic Carbon Age Structure, Brad E. Rosenheim, Valier Galy

Marine Science Faculty Publications

[1] Carbon cycling studies focusing on transport and transformation of terrigenous carbon sources toward marine sedimentary sinks necessitate separation of particulate organic carbon (OC) derived from many different sources and integrated by river systems. Much progress has been made on isolating and characterizing young biologically-formed OC that is still chemically intact, however quantification and characterization of old, refractory rock-bound OC has remained troublesome. Quantification of both endmembers of riverine OC is important to constrain exchanges linking biologic and geologic carbon cycles and regulating atmospheric CO₂ and O₂. Here, we constrain petrogenic OC proportions in suspended sediment from …

Salinity Gradient Power (Sgp): A Developmental Roadmap Covering Existing Generation Technologies And Recent Investigative Results Into The Feasibility Of Bipolar Membrane-Based Salinity Gradient Power Generation, Clifford R. Merz, Wilfrido A. Moreno, Marilyn Barger, Stephen M. Lipka

Marine Science Faculty Publications

Besides wind and solar-based renewable energy technologies, marine sources are being actively discussed. Sources of marine renewable energy traditionally have included ocean currents, ocean waves, tides, thermal gradients, and salinity gradients. Salinity gradient power (SGP) is an attractive marine renewable resource because it possesses not only the largest energy potential but likely the largest total available resource as well. SGP is instantly available when diluted and concentrated ionic solutions are mixed; is renewable, sustainable, and produces no CO₂ emissions or other significant effluents that may interfere with global climate. The ultimate challenge is in the economics of the recovery …

Phisigns: An Online Tool To Identify Signaturegenes In Phages And Design Pcr Primers Forexamining Phage Diversity, Bhakti Dwivedi, Robert Schmieder, Dawn Goldsmith, Robert Edwards, Mya Breitbart

Marine Science Faculty Publications

Background

Phages (viruses that infect bacteria) have gained significant attention because of their abundance, diversity and important ecological roles. However, the lack of a universal gene shared by all phages presents a challenge for phage identification and characterization, especially in environmental samples where it is difficult to culture phage-host systems. Homologous conserved genes (or "signature genes") present in groups of closely-related phages can be used to explore phage diversity and define evolutionary relationships amongst these phages. Bioinformatic approaches are needed to identify candidate signature genes and design PCR primers to amplify those genes from environmental samples; however, there is currently …

Human Induced Turbidity Changes In Poyang Lake Between 2000 And 2010: Observations From Modis, Lian Feng, Chuanmin Hu, Xiaoling Chen, Liqiao Tian, Liqiong Chen

Marine Science Faculty Publications

A robust retrieval algorithm to estimate concentrations of total suspended sediments (TSS) in Poyang Lake (the largest freshwater lake in China) was developed using Moderate Resolution Imaging Spectroradiometer (MODIS) medium-resolution (250 m) data from 2000 to 2010 and in situ data collected during two cruise surveys. The algorithm was based on atmospherically corrected surface reflectance at 645 nm, with 1240 nm data serving as a reference for aerosols and a nearest-neighbor method was used to avoid land adjacency effect. The algorithm showed an uncertainty of 30–40% for TSS ranging between 3 and 200 mg L⁻¹. Long-term TSS distribution …

An Ims/Atp Assay For The Detection Of Mycobacterium Tuberculosis In Urine, Dawn M. Hunter, Daniel V. Lim

Molecular Biosciences Faculty Publications

Background. Although sputum smears are the gold standard for diagnosis of tuberculosis, sensitivity in HIV/TB coinfection cases is low, indicating a need for alternative methods. Urine is being increasingly evaluated. Materials and Methods. A novel method for detecting Mycobacterium tuberculosis (MTB) in synthetic urine using a combined IMS/ATP assay was evaluated. Preliminary work established standard ATP conditions and the sensitivity and specificity of the MTB antibody. Eighty-four blinded samples in four replicate assays were evaluated for the presence of MTB using labeled immunomagnetic beads for capture. Beads were separated, washed, and resuspended in broth and added to a …

Identification Of New Cell Size Control Genes In S. Cerevisiae, Huzefa Dungrawala, Hui Hua, Jill Wright, Lesley Abraham, Thivakorn Kasemsri, Anthony Mcdowell, Jessica Stilwell, Brandt L. Schneider

Molecular Biosciences Faculty Publications

Cell size homeostasis is a conserved attribute in many eukaryotic species involving a tight regulation between the processes of growth and proliferation. In budding yeast S. cerevisiae, growth to a “critical cell size” must be achieved before a cell can progress past START and commit to cell division. Numerous studies have shown that progression past START is actively regulated by cell size control genes, many of which have implications in cell cycle control and cancer. Two initial screens identified genes that strongly modulate cell size in yeast. Since a second generation yeast gene knockout collection has been generated, we screened …

The Two-Component Signal Transduction System Arlrs Regulates Staphylococcus Epidermidis Biofilm Formation In An Ica-Dependent Manner, Yang Wu, Jiaxue Wang, Tao Xu, Jingran Liu, Wenqi Yu, Qiang Lou, Tao Zhu, Nianan He, Haijing Ben, Jian Hu, Friedrich Götz, Di Qu

Molecular Biosciences Faculty Publications

Due to its ability to form biofilms on medical devices, Staphylococcus epidermidis has emerged as a major pathogen of nosocomial infections. In this study, we investigated the role of the two-component signal transduction system ArlRS in regulating S. epidermidis biofilm formation. An ArlRS-deficient mutant, WW06, was constructed using S. epidermidis strain 1457 as a parental strain. Although the growth curve of WW06 was similar to that of SE1457, the mutant strain was unable to form biofilms in vitro. In a rabbit subcutaneous infection model, sterile disks made of polymeric materials were implanted subcutaneously followed with inoculation of WW06 or SE1457. …

Wipi-1 Positive Autophagosome-Like Vesicles Entrap Pathogenic Staphylococcus Aureus For Lysosomal Degradation, Mario Mauthe, Wenqi Yu, Oleg Krut, Martin Krönke, Friedrich Götz, Horst Robenek, Tassula Proikas-Cezanne

Molecular Biosciences Faculty Publications

Invading pathogens provoke the autophagic machinery and, in a process termed xenophagy, the host cell survives because autophagy is employed as a safeguard for pathogens that escaped phagosomes. However, some pathogens can manipulate the autophagic pathway and replicate within the niche of generated autophagosome-like vesicles. By automated fluorescence-based high content analyses, we demonstrate that Staphylococcus aureus strains (USA300, HG001, SA113) stimulate autophagy and become entrapped in intracellular PtdIns(3)P-enriched vesicles that are decorated with human WIPI-1, an essential PtdIns(3)P effector of canonical autophagy and membrane protein of both phagophores and autophagosomes. Further, agr-positive S. aureus (USA300, HG001) strains were more efficiently …

Guide To Agave, Cinnamomum, Corymbia, Eucalyptus, Pandanus, And Sansevieria In The Flora Of Florida, Alan R. Franck

Molecular Biosciences Faculty Publications

Several species-rich groups of non-native taxa occur in Florida and can be difficult to identify. This synopsis provides identification keys and brief discussions of the naturalized species of six genera in Florida: Agave, Cinnamomum, Corymbia, Eucalyptus, Pandanus, and Sansevieria. Of the genera treated here, only one taxon is presumed to be a pre-Columbian native, Agave decipiens, and all others are considered exotic. Agave neglecta is treated as a synonym of A. weberi. Cinnamomum burmannii, Pandanus odorifer, and Sansevieria trifasciata are here reported for the first time in the flora …

Chemical Defense In The Cave-Dwelling Millipede Brachydesmus Troglobius Daday, 1889 (Diplopoda, Polydesmidae), Slobodan E. Makarov, Ljubodrag V. Vujisić, Božidar P. M. Ćurčić, Bojan S. Ilić, Vele V. Tešević, Vlatka E. Vajs, Ivan M. Vučković, Bojan M. Mitić, Luka R. Lučić, Iris Ž. Đorđević

International Journal of Speleology

The troglomorphic millipede Brachydesmus troglobius Daday, 1889 (Polydesmida: Polydesmidae) secretes allomones from glands on both lateral surfaces of its body segments. The secretion was identified by gas chromatography-mass spectrometry (GC-MS) analysis with electron and chemical ionization, and was shown to be composed of a mixture of benzaldehyde, benzyl alcohol, benzoylnitrile, benzoic acid and mandelonitrile benzoate. Hydrogen cyanide was qualitatively identified by the picric acid test. This is the first identification of these compounds in a cave-dwelling polydesmid.

Chemoorganotrophic Bacteria Isolated From Biodeteriorated Surfaces In Cave And Catacombs, Filomena De Leo, Agnese Iero, Gabrielle Zammit, Clara E. Urzi

International Journal of Speleology

The main objective of this work was the comparative analysis of a large number of bacterial strains isolated from biodeteriorated surfaces in three different sites, namely the catacombs of St. Callistus in Rome, Italy, the catacombs dedicated to St. Agatha in Rabat, Malta and the Cave of Bats in Zuheros, Spain. Our results showed that even considering only culturable chemoorganotrophic bacteria the variability is very high, reflecting the great variety of microhabitats present. Hence any strategies to prevent, control or eliminate the biofilm-embedded microbiota from an archeological surface should take into account a number of considerations as stipulated in our …

Duality Of Terrestrial Subterranean Fauna, Tone Novak, Matjaž Perc, Saška Lipovšek, Franc Janžekovič

International Journal of Speleology

Terrestrial animals in subterranean habitats are often classified according to their degree of morphological or ecological specialization to the subterranean environment. The commonly held view is that, as distance into a cave increases, the frequency of morphologically specialized, i.e., troglomorphic, species or ecological specialization will increase. We tested this hypothesis for the fauna in 54 caves in Slovenia–the classical land for subterranean biology. We found that there exist two ecologically well separated terrestrial subsurface faunas: one shallow and one deep. 1) The shallow subterranean fauna, adapted to the terrestrial shallow subterranean habitats (SSHs) in the upper 10 m of subsurface …

Reply To Comment By W. R. Peltier Et Al. On “Ocean Mass From Grace And Glacial Isostatic Adjustment”, D. P. Chambers, John Wahr, Mark E. Tamisiea, R. Steven Nerem

Marine Science Faculty Publications

No abstract provided.

Is There A 60-Year Oscillation In Global Mean Sea Level?, Don P. Chambers, Mark A. Merrifield, R. Steven Nerem

Marine Science Faculty Publications

[1] We examine long tide gauge records in every ocean basin to examine whether a quasi 60-year oscillation observed in global mean sea level (GMSL) reconstructions reflects a true global oscillation, or an artifact associated with a small number of gauges. We find that there is a significant oscillation with a period around 60-years in the majority of the tide gauges examined during the 20th Century, and that it appears in every ocean basin. Averaging of tide gauges over regions shows that the phase and amplitude of the fluctuations are similar in the North Atlantic, western North Pacific, and Indian …

Energetic Plasticity Underlies A Variable Response To Ocean Acidification In The Pteropod, Limacina Helicina Antarctica, Brad A. Seibel, Amy E. Maas, Heidi M. Dierssen

Marine Science Faculty Publications

Ocean acidification, caused by elevated seawater carbon dioxide levels, may have a deleterious impact on energetic processes in animals. Here we show that high PCO₂ can suppress metabolism, measured as oxygen consumption, in the pteropod, L. helicina forma antarctica, by ∼20%. The rates measured at 180–380 µatm (MO₂  = 1.25 M^−0.25, p = 0.007) were significantly higher (ANCOVA, p  =  0.004) than those measured at elevated target CO₂ levels in 2007 (789–1000 µatm,  =  0.78 M^−0.32, p  =  0.0008; Fig. 1). However, we further demonstrate metabolic plasticity in response to regional …

Bacterial Community Survey Of Sediments At Naracoorte Caves, Australia, Eric M. Adetutu, Krystal Thorpe, Esmaeil Shahsavari, Steven Bourne, Xiangsheng Cao, Ramin Mazaheri Nezhad Fard, Greg Kirby, Andrew S. Ball

International Journal of Speleology

Bacterial diversity in sediments at UNESCO World Heritage listed Naracoorte Caves was surveyed as part of an investigation carried out in a larger study on assessing microbial diversity in caves. Cave selection was based on tourist accessibility; Stick Tomato and Alexandra Cave (> 15000 annual visits) and Strawhaven Cave was used as control (no tourist access). Microbial analysis showed that Bacillus was the most commonly detected microbial genus by culture dependent and independent survey of tourist accessible and inaccessible areas of show (tourist accessible) and control caves. Sediment bacterial groups were assigned to the Firmicutes, Actinobacteria and Proteobacteria. The survey …

The World’S Deepest Subterranean Community - Krubera-Voronja Cave (Western Caucasus), Alberto Sendra, Ana Sofia P.S. Reboleira

International Journal of Speleology

Subsurface biota extends over a wide variety of habitats that can be spatially interconnected. The largest communities of this subsurface biota inhabit cavities and are well known mainly in caves where biologists are able to have access. Data about deep subterranean communities and arthropods living under one thousand meters was unknown.

An expedition to world’s deepest cave, Krubera-Voronja in Western Caucasus, revealed an interesting subterranean community, living below 2000 meters and represented by more than 12 species of arthropods, including several new species for science. This deep cave biota is composed of troglobionts and also epigean species, that can penetrate …

Diversity And Community Assembly Patterns Of Epigean Vs. Troglobiont Spiders In The Iberian Peninsula, Pedro Cardoso

International Journal of Speleology

Cave-obligate organisms usually have smaller ranges and their assemblages have higher beta diversity than their epigean counterparts. Phylogenetic and functional diversity is usually low in cave communities, leading to taxonomic and functional disharmony, with entire groups missing from the subterranean realm. The objective of this work is to compare range, beta diversity, phylogenetic and functional diversity, taxonomic and functional disharmony of epigean versus troglobiont spiders in the Iberian Peninsula.

The median extent of occurrence was found to be 33 times higher for epigean than for cave species. Beta diversity was significantly higher for troglobiont assemblages. Cave assemblages present lower phylogenetic …

Consequences Of Kleptoplasty On The Distribution, Ecology, And Behavior Of The Sacoglossan Sea Slug, Elysia Clarki, Michael Louis Middlebrooks

USF Tampa Graduate Theses and Dissertations

The sacoglossan sea slug Elysia clarki is able to photosynthesize for three to four months using chloroplasts sequestered from its algal food sources. Furthermore, the slug is able to store multiple chloroplasts from different algal species within the same cell. This research, consisting of several related studies, explores the role that provision of organic nutrients via photosynthesis plays in the biology of the slug. The first chapter demonstrates that, under conditions of starvation, photosynthetic activity in E. clarki remains fully functional for one month after which it then declines. During the first month of starvation the slug exhibits similar feeding …