Life Sciences Commons^™

The Effects Of 11 Yr Of Co2 Enrichment On Roots In A Florida Scrub-Oak Ecosystem, Frank Day, Rachel E. Schroeder, Daniel B. Stover, Alisha L. P. Brown, John R. Butnor, John Dilustro, Bruce A. Hungate, Paul Dijkstra, Benjamn D. Duval, Troy J. Seiler

Biological Sciences Faculty Publications

• Uncertainty surrounds belowground plant responses to rising atmospheric CO₂ because roots are difficult to measure, requiring frequent monitoring as a result of fine root dynamics and long-term monitoring as a result of sensitivity to resource availability.
• We report belowground plant responses of a scrub-oak ecosystem in Florida exposed to 11yr of elevated atmospheric CO₂ using open-top chambers. We measured fine root production, turnover and biomass using minirhizotrons, coarse root biomass using ground-penetrating radar and total root biomass using soil cores.
• Total root biomass was greater in elevated than in ambient plots, and the absolute difference was larger than …

Phytoplankton In Virginia Lakes And Reservoirs, Harold G. Marshall

Biological Sciences Faculty Publications

This study involves a phytoplankton summer/autumn survey in 46 Virginia lakes and reservoirs during 2010-2012. A total of 307 taxa were identified which included several filamentous and colonial cyanabacteria in bloom concentrations. With the exception of one natural lake, the other sites sampled represent impoundments created decades ago, with the majority presently classified as meso- or eutrophic. Among the cyanobacteria were 6 known toxin producers (Anabaena circinalis, Anabaena spiroides, Aphanizomenon flos-aquae, Cylindrospermopsis raciborskii, Limnothrix redekei, and Microcystis aeruginosa). The study characterizes phytoplankton populations in these aging freshwater habitats taken from a large number …

Thalassiosira Spp. Community Composition Shifts In Response To Chemical And Physical Forcing In The Northeast Pacific Ocean, P. Dreux Chappell, Leann P. Whitney, Traci L. Haddock, Susanne Menden-Deuer, Eric G. Roy, Mark L. Wells, Bethany D. Jenkins

Biological Sciences Faculty Publications

Diatoms are genetically diverse unicellular photosynthetic eukaryotes that are key primary producers in the ocean. Many of the over 100 extant diatom species in the cosmopolitan genus Thalassiosira are difficult to distinguish in mixed populations using light microscopy. Here, we examine shifts in Thalassiosira spp. composition along a coastal to open ocean transect that encountered a 3-month-old Haida eddy in the northeast Pacific Ocean. To quantify shifts in Thalassiosira species composition, we developed a targeted automated ribosomal intergenic spacer analysis (ARISA) method to identify Thalassiosira spp. in environmental samples. As many specific fragment lengths are indicative of individual Thalassiosira spp., …

Age-Associated Metabolic And Morphologic Changes In Mitochondria Of Individual Mouse And Hamster Oocytes, Fatma Simsek-Duran, Fang Li, Wentia Ford, R. James Swanson, Howard W. Jones Jr., Frank J. Castora

Biological Sciences Faculty Publications

Background: In human oocytes, as in other mammalian ova, there is a significant variation in the pregnancy potential, with approximately 20% of oocyte-sperm meetings resulting in pregnancies. This frequency of successful fertilization decreases as the oocytes age. This low proportion of fruitful couplings appears to be influenced by changes in mitochondrial structure and function. In this study, we have examined mitochondrial biogenesis in both hamster (Mesocricetus auratus) and mouse (Mus musculus) ova as models for understanding the effects of aging on mitochondrial structure and energy production within the mammalian oocyte.

Methodology/Principal Findings: Individual metaphase …

Wintering Eiders Acquire Exceptional Se And Cd Burdens In The Bering Sea: Physiological And Oceanographic Factors, James R. Lovvorn, Merl F. Raisbeck, Lee W. Cooper, Gregory A. Cutter, Micah W. Miller, Marjorie L. Brooks, Jacqueline M. Grebmeier, Angela C. Matz, Cortney M. Schaefer

OES Faculty Publications

During late winter (March) in the Bering Sea, levels of Se in livers and Cd in kidneys of spectacled eiders Somateria fischeri were exceptionally high (up to 489 and 312 µg g⁻¹ dry mass, respectively). Comparison of organ and blood samples during late winter, early spring migration, and breeding suggests that the eiders’ high Se and Cd burdens were accumulated at sea, with highest exposure during winter. High exposure may have resulted from high metabolic demands and food intake, as well as concentrations in food. In the eiders’ remote wintering area, their bivalve prey contained comparable Se levels and …

Periplasmic Binding Proteins In Thermophiles: Characterization And Potential Application Of An Arginine-Binding Protein From Thermotoga Maritima: A Brief Thermo-Story, Alessio Ausili, Maria Staiano, Jonathan D. Dattelbaum, Antonio Varriale, Alessandro Capo, Sabato D'Auria

Chemistry Faculty Publications

Arginine-binding protein from the extremophile Thermotoga maritima is a 27.7 kDa protein possessing the typical two-domain structure of the periplasmic binding proteins family. The protein is characterized by a very high specificity and affinity to bind to arginine, also at high temperatures. Due to its features, this protein could be taken into account as a potential candidate for the design of a biosensor for arginine. It is important to investigate the stability of proteins when they are used for biotechnological applications. In this article, we review the structural and functional features of an arginine-binding protein from the extremophile Thermotoga maritima …

Structurally Diverse Hamigerans From The New Zealand Marine Sponge Hamigera Tarangaensis: Nmr-Directed Isolation, Structure Elucidation And Antifungal Activity, A. Jonathan Singh, Jonathan D. Dattelbaum, Jessica J. Field, Zlatka Smart, Ethan F. Woolly, Jacqueline M. Barber, Rosemary Heathcott, John H. Miller, Peter T. Northcote

Chemistry Faculty Publications

The NMR-directed investigation of the New Zealand marine sponge Hamigera tarangaensis has afforded ten new compounds of the hamigeran family, and a new 13-epi-verrucosane congener. Notably, hamigeran F (6) possesses an unusual carbon–carbon bond between C-12 and C-13, creating an unprecedented skeleton within this class. In particular, the structural features of 6, hamigeran H (10) and hamigeran J (12) imply a diterpenoid origin, which has allowed the putative biogenesis of three hamigeran carbon skeletons to be proposed based on geranyl geranyl pyrophosphate. All new hamigerans exhibited micromolar activity towards the HL-60 …

Differential Allocation To Photosynthetic And Non-Photosynthetic Nitrogen Fractions Among Native And Invasive Species, Jennifer L. Funk, Lori A. Glenwinkle, Lawren Sack

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Invasive species are expected to cluster on the “high-return” end of the leaf economic spectrum, displaying leaf traits consistent with higher carbon assimilation relative to native species. Intra-leaf nitrogen (N) allocation should support these physiological differences; however, N biochemistry has not been examined in more than a few invasive species. We measured 34 leaf traits including seven leaf N pools for five native and five invasive species from Hawaii under low irradiance to mimic the forest understory environment. We found several trait differences between native and invasive species. In particular, invasive species showed preferential N allocation to metabolism (amino acids) …

Factors Shaping The Ontogeny Of Vocal Signals In A Wild Parrot, Karl S. Berg, Steven R. Beissinger, Jack W. Bradbury

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Parrots rely heavily on vocal signals to maintain their social and mobile lifestyles. We studied vocal ontogeny in nests of wild green-rumped parrotlets (Forpus passerinus) in Venezuela. We identified three successive phases of vocal signaling that corresponded closely to three independently derived phases of physiological development. For each ontogenetic phase, we characterized the relative importance of anatomical constraints, motor skills necessary for responding to specific contexts of the immediate environment, and the learning of signals that are necessary for adult forms of communication. We observed shifts in the relative importance of these three factors as individuals progressed from …

Opportunistic Pathogenic Bacteria Colonize Thorns Of Native Rio Grande Valley Plants, Felicia A. Charles, Sergio Cepeda, J. Andrew Mcdonald, Kristine L. Lowe

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Thorns serve as mechanical defenses of plants against herbivory. However, plant thorns harbor microorganisms that are potentially pathogenic. These pathogens may be transferred to herbivores and other animals and provide an additional defense for the plants. Thorns from 5 plant species native to the Rio Grande Valley of South Texas were collected and used to isolate bacteria colonizing the thorn surface. Thorns, leaves and stems of plants were visualized using Scanning Electron Microscopy (SEM) to observe any bacteria on the plant surface. Isolated bacteria were tested for their ability to grow in aerobic versus anaerobic environments, to produce hemolysis, carbon …

Arthropod Abundance And Diversity In Street Trees Of South Texas, Usa, Alexis Racelis, Ann T. Vacek, Carol Goolsby, John Brush, John A. Goolsby

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

In urban areas, street trees provide a variety of ecological services, including biodiversity conservation. In this study we examined arthropod diversity on native and non-native street trees sampled during the fall of 2010 and spring of 2011 in McAllen, Texas, one of the most rapidly growing urban areas in the country. Eighty-eight street trees were sampled by removing arthropods from the lower canopy foliage using a hand held vacuum. Arthropods were collected into nylon bags, identified to order, and counted by morphospecies. Overall, street trees supported a significant and diverse population of arthropods: a total of 1,971 arthropods were collected, …

Mitigating Predatory Ants Promotes Establishment Of Biological Control Of Arundo By Arundo Scale In The Cattle Fever Tick Quarantine Zone, A. Velez-Bonner, W. L. A. Osbrink, D. W. Thomas, Kenneth R. Summy, A. T. Showler, A. Perez De Leon, John A. Goolsby

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Ant collection, identification, and control experiments were conducted to improve the establishment of the arundo scale, Rhizaspidiotus donacis, a biological control agent of Arundo donax, an invasive weed in the riparian habitats along the Rio Grande in Texas. Observational studies indicated R. donacis immatures are preyed upon by a variety of predator insects, especially ants. A survey of the principle ant species was made at sites along the Rio Grande with Arundo donax to help direct biological control strategies. We conclude that uses of ant baits can effectively control the common ant species found in these habitats and improve the …

Innovative Food Product Development Using Molecular Gastronomy: A Focus On Flavour And Sensory Evaluation, Mark Traynor

Doctoral

The primary goal of this research was to develop novel ice cream products using the principles of molecular gastronomy. An ice cream model system (emulsion) was developed, in which the effects of ingredient levels on stability and formation were investigated and optimised using Response Surface Methodology (RSM). Two characteristic volatiles of banana (isoamyl acetate and furfuryl acetate) were added to the optimised emulsion, and their headspace emission was quantified using Solid Phase Microextraction with Gas Chromatography Mass Spectrometry. RSM was used to investigate the main and interactive effects of ingredient, salt and pH levels on the headspace emission of these …

The Effect Of Acute Beetroot Juice Supplementation On Muscle Fatigue In Knee Extensor Exercise, Seungyong Lee

Theses and Dissertations--Kinesiology and Health Promotion

To examine the effect of acute beetroot juice supplementation on the rate of fatigue as measured by changes in peak torque.

Placebo-controlled, double-blind, cross-over study, 35 recreationally active subjects consumed beetroot (BR) juice or black currant juice (PL) 12 and 2.5 hours before the exercise procedure. Peak torque was measured on the BIODEX dynamometer by performing 50, maximal effort, concentric knee extensions at 90°/s. Blood pressure (BP) was recorded before and after exercise.

No significant difference between BR and PL in the rate of fatigue measured by change in peak torque. By stage 3, subjects retained 87.6±6.9% of strength with …

Cardiorespiratory Responses In Healthy-Weight And Obese Women And Children, Elizabeth Ann Easley

Theses and Dissertations--Kinesiology and Health Promotion

A criterion method to evaluate cardiorespiratory health is measuring peak oxygen consumption (VO₂ peak) from a maximal graded exercise test (GXT). While VO₂ peak is a valuable measure, heart rate recovery (HRRec) and endothelial function (EF) also describe cardiorespiratory health and fitness. The purpose of this study was to investigate whether differences exist in VO₂ peak, HRRec, and EF between healthy-weight (HW) and obese (OB) women and children and to determine if there were significant correlations among these variables. A total of 60 women and children participated in this study. Anthropometric, body composition, resting heart rate and …

The Molecular Basis Of Antibody Mediated Neutralization Of Hepatitis C Virus, Michelle Catherine Sabo

All Theses and Dissertations (ETDs)

Hepatitis C virus: HCV) is positive strand, blood-borne, hepatotropic RNA virus that causes chronic infection in ~170 million people worldwide and is the leading cause of liver transplantation in the United States. HCV entry and attachment is mediated by the envelope protein E2 through interaction with several cellular receptors including CD81, scavenger receptor B1: SRB-1), claudin-1, and occludin, although the exact mechanism by which these receptors facilitate infection remains unclear, largely due to the absence of a structural model of E2. The production of neutralizing antibodies against E2 is thought to be important for controlling HCV infection, likely by blocking …

Menthol Binding And Inhibition Of A7-Nicotinic Acetylcholine Receptors, Abrar Ashoor, Jacob C. Nordman, Daniel Veltri, Keun-Hang Susan Yang, Lina T. Al Kury, Yaroslav M. Shuba, Mohamed Magoub, Frank Christopher Howarth, Bassem Sadek, Amarda Shehu, Nadine Kabbani, Murat Oz

Mathematics, Physics, and Computer Science Faculty Articles and Research

Menthol is a common compound in pharmaceutical and commercial products and a popular additive to cigarettes. The molecular targets of menthol remain poorly defined. In this study we show an effect of menthol on the α7 subunit of the nicotinic acetylcholine (nACh) receptor function. Using a two-electrode voltage-clamp technique, menthol was found to reversibly inhibit α7-nACh receptors heterologously expressed in Xenopus oocytes. Inhibition by menthol was not dependent on the membrane potential and did not involve endogenous Ca2+-dependent Cl− channels, since menthol inhibition remained unchanged by intracellular injection of the Ca2+ chelator BAPTA and perfusion with Ca2+-free bathing solution containing …

Differential Modulation Of Functional Dynamics And Allosteric Interactions In The Hsp90-Cochaperone Complexes With P23 And Aha1: A Computational Study, Kristin Blacklock, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Allosteric interactions of the molecular chaperone Hsp90 with a large cohort of cochaperones and client proteins allow for molecular communication and event coupling in signal transduction networks. The integration of cochaperones into the Hsp90 system is driven by the regulatory mechanisms that modulate the progression of the ATPase cycle and control the recruitment of the Hsp90 clientele. In this work, we report the results of computational modeling of allosteric regulation in the Hsp90 complexes with the cochaperones p23 and Aha1. By integrating protein docking, biophysical simulations, modeling of allosteric communications, protein structure network analysis and the energy landscape theory we …

Inter- And Intra-Annual Variability Of Vegetation In The Northern Hemisphere And Its Association With Precursory Meteorological Factors, Boksoon Myoung, Yong-Sang Choi, Seungbum Hong, Seon Ki Park

Mathematics, Physics, and Computer Science Faculty Articles and Research

Determination of phenological variation is one of the most critical challenges in dynamic vegetation modeling, given the lack of a strong theoretical framework. Previous studies generally focused on the timing of a phenological event (e.g., bud-burst or onset of growing season) and its atmospheric prompts, but not on the interactive variations across phenological stages. This study, therefore, investigated the inter- and intra-annual variability existing in all the phenological stages and the relations of the variability with four meteorological variables (surface temperature (Ts), shortwave radiation (SW ), vapor pressure deficit (VPD), and precipitation (PRCP)) using a 25-year (1982-2006) dataset of leaf …

In The News, Joe N. Caudell

Human–Wildlife Interactions

No abstract provided.

Commentary Managing Risk From Bears And Other Potentially Lethal Wildlife: Predictability, Accountability, And Liability, Stephen Stringham

Human–Wildlife Interactions

No abstract provided.

Commentary Rethinking Airport Land-Cover Paradigms: Agriculture, Grass, And Wildlife Hazards, Travis L. Devault, Michael J. Begier, Jerrold L. Belant, Bradley F. Blackwell, Richard A. Dolbeer, James A. Martin, Thomas W. Seamans, Brian E. Washburn

Human–Wildlife Interactions

No abstract provided.

Effects Of Site Characteristics, Pinyon-Juniper Management, And Precipitation On Habitat Quality For Mule Deer In New Mexico, Louis C. Bender, Jon C. Boren, Heather Halbritter, Shad Cox

Human–Wildlife Interactions

Wildlife enterprises are increasingly important to ranch income in the western United States. Habitat management practices that facilitate wildlife are needed for optimal management of multiple-use ranches, particularly for economically important species, such as mule deer (Odocoileus hemionus), that are declining throughout much of their range. We tested the effects of vegetation cover type, site characteristics, pinyon-juniper management treatments, and precipitation on body condition and size of spring-summer-autumn (SSA) home ranges of mule deer to assess habitat quality on the Corona Range and Livestock Research Center (CRLRC), a multiple-use research ranch in east central New Mexico. Accrual of …

Reliability And Precision Of Pellet-Group Counts For Estimating Landscape-Level Deer Density, David Decalesta

Human–Wildlife Interactions

This study provides hitherto unavailable methodology for reliably and precisely estimating deer density within forested landscapes, enabling quantitative rather than qualitative deer management. Reliability and precision of the deer pellet-group technique were evaluated in 1 small and 2 large forested landscapes. Density estimates, adjusted to reflect deer harvest and overwinter mortality, were compared with a drive count on the small landscape and with aerial counts using forward-looking infrared videography (FLIR) on the large landscapes. Estimates by 2 expert and 2 novice counters (range = 17.6 to 18.6 deer/km²) on the small landscape were not different from each other …

Jaguar And Puma Attacks On Livestock In Costa Rica, Ronit Amit, Elias José Gordillo-Chávez, Raquel Bone

Human–Wildlife Interactions

Human–felid conflicts threaten long-term conservation of jaguars (Panthera onca) and pumas (Puma concolor). We interviewed ranchers from 50 ranches and inspected farms in northern Costa Rica that reported recent attacks on livestock by these 2 felids. We analyzed ranch characteristics, livestock management practices, details of predation, estimated market-value of economic losses, and ranchers’ perception of damage. Ranchers reported 81 felid attacks on livestock, including 60 head of cattle, 16 horses, 3 sheep, 1 pig, and 1 goat. Mean size of ranches was 233 km², and mean livestock herd size was 109, including cattle, horses, …

Consumption Of Whole Cottonseed By White-Tailed Deer And Nontarget Species, Benjamin D. Taylor, Eddie Lyons, Dale Rollins, Cody B. Scott, James E. Huston, Charles A. Taylor

Human–Wildlife Interactions

Supplementing diets of white-tailed deer (Odocoileus virginianus) with pelleted rations is an increasingly common practice aimed at increasing deer antler size on rangelands in Texas. Feed loss to consumption by various nontarget species (e.g., raccoons [Procyon lotor] and feral pigs [Sus scrofa]) raises both ecological and economic concerns. Whole cottonseed is a feedstuff that may afford a more targeted supplemental feeding effort. Accordingly, we determined: (1) consumption rates of whole cottonseed by feral pigs and raccoons in captivity; and (2) species visitation at feed sites and preference for whole cottonseed relative to whole corn …

Deer-Activated Bioacoustic Frightening Device Deters White-Tailed Deer, Aaron M. Hildreth, Scott E. Hygnstrom, Kurt C. Vercauteren

Human–Wildlife Interactions

White-tailed deer (Odocoileus virginianus) damage urban and suburban plantings, as well as crops and stored feed. We tested the efficacy of a frightening device that played pre-recorded distress calls of adult female white-tailed deer when activated by an infrared motion sensor for a period of 13 days. This deer-activated bioacoustic frightening device reduced deer entry into protected sites by 99% (δ = -558, P = 0.09) and bait consumption by 100% (δ = -75, P = 0.06). The frightening device that we evaluated demonstrated potential for reducing damage in disturbed environments and agricultural settings.

Toward An Understanding Of Beaver Management As Human And Beaver Densities Increase, William F. Siemer, Sandra A. Jonker, Daniel J. Decker, John F. Organ

Human–Wildlife Interactions

Estimates of beaver (Castor canadensis) density play an important role in wildlife managers’ decisions about beaver population management, because managers anticipate higher incidence of problem complaints when a beaver population increases. To manage the impacts of beavers in an urbanizing landscape, managers need better information on changes in stakeholder beliefs and attitudes as beaver and human densities reach high levels. We conducted additional analysis of data collected in 2002 through mail surveys of residents in New York and Massachusetts to test hypothesized relationships between beaver density and damage experience, attitudes toward beavers, and norms about beaver management actions. …

Do Artificial Nests Simulate Nest Success Of Greater Sage-Grouse?, Jonathan B. Dinkins, Michael R. Conover, Scott T. Mabray

Human–Wildlife Interactions

Artificial nests have been used to study factors affecting nest success because researchers can manipulate them more than natural bird nests. Many researchers have questioned the validity of generalizing the results from artificial nests onto naturally occurring nests. Other studies have assessed the validity of artificial nest studies by simultaneously comparing overall depredation or daily survival rates, depredation timing, predator species, or habitat characteristics of artificial and natural nests. To evaluate how well artificial nests simulated nest success of greater sage-grouse (Centrocercus urophasianus; hereafter, sagegrouse), we used the unique approach of monitoring artificial nests (n = 69) placed …

Monitoring Microbial Diversity Of A Full-Scale Municipal Wastewater Treatment Plant In Dubai, Munawwar Ali Khan, Javeria Mohsin, Sultan Mohammad Faheem

All Works

In this study, fluorescence in situhybridization (FISH) technique was employedfor monitoring the microbial community in the activated sludge system of a full-scale municipal wastewater treatment plant in Dubai over a period of one year. A total of 96 activated sludge mixed liquor samples were characterized using ribosomal RNA (16S and 23S rRNA) targeted oligonucleotide probes for defined phylogenetic groups of bacteria. Several filamentous and non-filamentous bacteriawere predominantly found throughout the study period in all activated sludge mixed liquor samples. The bacterial species belonging to High G+C group were detected in both branched and single cell morphotypes. The previously published genus …