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Articles 1441 - 1470 of 1820

Full-Text Articles in Life Sciences

Comparison Of Soil Chemistry And Microbial Communities That Inhabit The Rhizosphere Of Native And Non-Native Grasses Of The Lower Rio Grande Valley, Jacqueline Valencia Jul 2011

Comparison Of Soil Chemistry And Microbial Communities That Inhabit The Rhizosphere Of Native And Non-Native Grasses Of The Lower Rio Grande Valley, Jacqueline Valencia

Theses and Dissertations - UTB/UTPA

Non-native grasses can modify the soils they invade. This study investigated microbial variation among native and non-native grasses in the Lower Rio Grande Valley. We hypothesized that rhizospheres of non-native grasses would support a higher density of microorganisms; therefore microbial communities of invasive plants would exploit more carbon sources than those of native plants. A second hypothesis stated that Streptomyces bacteria from the rhizosphere of non-native grasses would be better competitors. Samples of grasses, and soil from their respective rhizospheres were obtained in Arroyo City, TX. Results indicated a higher bacterial colony density, total activity and number of substrates utilized …


Color Polymorphism Of Sand Crabs, Lepidopa Benedicti (Decapoda: Anomura: Albuneidae), Unnam Nasir, Zen Faulkes Apr 2011

Color Polymorphism Of Sand Crabs, Lepidopa Benedicti (Decapoda: Anomura: Albuneidae), Unnam Nasir, Zen Faulkes

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

Sand crabs (Lepidopa benedicti) are highly specialized digging animals that spend the vast majority of their adult life submerged in fine sand. The carapace color of L. benedicti varies from gray to white. Given that the environment in which they live is uniform and dark, most of the functional scenarios to explain color variation seem unlikely to apply. Carapace color has a bimodal distribution, indicating that it is better characterized as a polymorphism than simply as normal variation. Gray crabs are larger and more common than white ones. Crabs mostly swim ventral-side up, which suggests that countershading does …


Soil Nitrogen Transformations Under Elevated Atmospheric Co2 And O3 During The Soybean Growing Season, Engil Isadora Pujol Pereira, Haegeun Chung, Kate Scow, Michael J. Sadowsky, Chris Van Kessel Feb 2011

Soil Nitrogen Transformations Under Elevated Atmospheric Co2 And O3 During The Soybean Growing Season, Engil Isadora Pujol Pereira, Haegeun Chung, Kate Scow, Michael J. Sadowsky, Chris Van Kessel

School of Earth, Environmental, & Marine Sciences Faculty Publications

We investigated the influence of elevated CO2 and O3 on soil N cycling within the soybean growing season and across soil environments (i.e., rhizosphere and bulk soil) at the Soybean Free Air Concentration Enrichment (SoyFACE) experiment in Illinois, USA. Elevated O3 decreased soil mineral N likely through a reduction in plant material input and increased denitrification, which was evidenced by the greater abundance of the denitrifier gene nosZ. Elevated CO2 did not alter the parameters evaluated and both elevated CO2 and O3 showed no interactive effects on nitrifier and denitrifier abundance, nor on total and mineral N concentrations. These results …


A Phylogenetic Assessment Of Breeding Systems And Floral Morphology Of North American Ipomoea (Convolvulaceae), J. Andrew Mcdonald, Joshua R. Mcdill, Debra R. Hansen, Beryl B. Simpson Jan 2011

A Phylogenetic Assessment Of Breeding Systems And Floral Morphology Of North American Ipomoea (Convolvulaceae), J. Andrew Mcdonald, Joshua R. Mcdill, Debra R. Hansen, Beryl B. Simpson

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

A phylogenetic investigation of 68 species and two varieties of tropical and temperate North American Ipomoea (Convolvulaceae) using sequence data from the internal transcribed spacer region (ITS) with parsimony and Bayesian analyses revealed multiple origins of autogamy. By assessing breeding systems and floral morphological characters in the context of this phylogeny, we estimate 16 independent origins of autogamy and 4 subsequent reversions to xenogamy. Transitions to autogamy are associated with reduced pollen-ovule ratios, decreased anther-stigma distance, and small flower size. Although the relationship between floral traits and breeding systems has been described in previous studies, this is the first investigation …


Techniques To Facilitate The Acquisition Of Accurate Spectral Measurements And Multispectral Imagery Of Plant Foliage Under Artificial Lighting Conditions, Yuridia Patricia Gandy, Ashish Mamachen, Adarsh Mamachen, Jonathan Lieman, Michael W. Persans, Jason Parsons, Elamin E. Ibrahim, James H. Everitt, Christopher R. Little, Kenneth R. Summy Jan 2011

Techniques To Facilitate The Acquisition Of Accurate Spectral Measurements And Multispectral Imagery Of Plant Foliage Under Artificial Lighting Conditions, Yuridia Patricia Gandy, Ashish Mamachen, Adarsh Mamachen, Jonathan Lieman, Michael W. Persans, Jason Parsons, Elamin E. Ibrahim, James H. Everitt, Christopher R. Little, Kenneth R. Summy

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

Spectral measurements obtained in the laboratory under artificial lighting sources have been used for many years to develop spectral ‘libraries’ for various soil types, rocks and minerals, and other inanimate features occurring on or near the earth’s surface. Quartz halogen lamps have been shown to emit all of the electromagnetic (EMR) wavelengths required for the acquisition of quality multispectral imagery, and various techniques have been developed to facilitate the acquisition of accurate spectral measurements using such artificial lighting sources. Our objectives in this study were to evaluate the several factors of critical importance in obtaining accurate spectral measurements for plant …


Effects Of Leaf Excision And Sample Storage Methods On Spectral Reflectance By Foliage Of Giant Reed, Arundo Donax, Kenneth R. Summy, Jonathan Lieman, Yuridia Patricia Gandy, Adarsh Mamachen, Ashish Mamachen, John A. Goolsby, Patricia J. Moran Jan 2011

Effects Of Leaf Excision And Sample Storage Methods On Spectral Reflectance By Foliage Of Giant Reed, Arundo Donax, Kenneth R. Summy, Jonathan Lieman, Yuridia Patricia Gandy, Adarsh Mamachen, Ashish Mamachen, John A. Goolsby, Patricia J. Moran

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

Research was conducted to evaluate the effects of leaf excision and sample storage methods on spectral reflectance by foliage of giant reed, Arundo donax, an invasive weed which has caused extensive damage in many areas of the Rio Grande Basin in Texas and Mexico. Within 24 hours of excision, A. donax leaves exposed to ambient laboratory conditions (room temperature under natural lighting conditions) exhibited two trends indicative of physiological stress: 1) small but significant increases in reflectance of blue and red wavelengths (400-500 nm and 600-700 nm, respectively) and 2) a substantial reduction in reflectance of near-infrared (NIR) wavelengths (700-1,100 …


Due Diligence And Demographic Disparities: Effects Of The Planning Of U.S.- Mexico Border Fence On Marginalized Populations, J. Gaines Wilson, Jude A. Benavides, Karen Engle, Denise Gilman, Anthony Reisinger, Jessica Spangler, Joe Lemen Dec 2010

Due Diligence And Demographic Disparities: Effects Of The Planning Of U.S.- Mexico Border Fence On Marginalized Populations, J. Gaines Wilson, Jude A. Benavides, Karen Engle, Denise Gilman, Anthony Reisinger, Jessica Spangler, Joe Lemen

School of Earth, Environmental, & Marine Sciences Faculty Publications

In the buildup to the construction the U.S.-Mexico border fence by the United States Department of Homeland Security (USDHS), much attention was drawn to security, drug enforcement, and immigration issues. However, there was little quantitative analysis regarding which populations were most likely to be affected by the proposed fence. Using a geographic information system, we classified census blocks in Cameron County, Texas into one of two categories: either ‘fence’ or ‘gap’. A total of 14 demographic factors were tested for disparities between those living in gap areas and those living in areas exposed to the fence. Twelve of fourteen factors …


Investigating Heavy Metal Accumulation And Oxidative Stress Tolerance Of Non-Accumulators And Hyperaccumulators In The Brassicaceae Plant Family, Fritzie Joy Into Dec 2010

Investigating Heavy Metal Accumulation And Oxidative Stress Tolerance Of Non-Accumulators And Hyperaccumulators In The Brassicaceae Plant Family, Fritzie Joy Into

Theses and Dissertations - UTB/UTPA

Physiological and enzymatic analysis indicated that the non-accumulator A. thaliana showed an oxidative stress response in all assays except for protein carbonylation. Other non-accumulator plant species showed a significant difference in oxidative stress response in the TBARS assay; however, for some assays no stress response was evident. The hyperaccumulator plant species showed no significant difference in oxidative stress as indicated by the all of the assays with the exception of T. montanum var. montanum which showed an oxidative stress response in the SOD assay. Basal catalase enzyme activity was notably higher in the hyperaccumulators T. montanum var. montanum and T. …


Molecular Mechanisms Of Persistence Of Mutualistic Bacteria Photorhabdus In The Entomopathogenic Nematode Host, Ruisheng An, Parwinder Grewal Oct 2010

Molecular Mechanisms Of Persistence Of Mutualistic Bacteria Photorhabdus In The Entomopathogenic Nematode Host, Ruisheng An, Parwinder Grewal

School of Earth, Environmental, & Marine Sciences Faculty Publications

Symbioses between microbes and animals are ubiquitous, yet little is known about the intricate mechanisms maintaining such associations. In an emerging mutualistic model system, insect-pathogenic bacteria Photorhabdus and their insect-parasitic nematode partner Heterorhabditis, we found that the bacteria undergo major transcriptional reshaping in the nematode intestine. Besides general starvation mechanisms, the bacteria induce cellular acidification to slow down growth, switch to pentose phosphate pathway to overcome oxidative stress and nutrition limitation, and shed motility but develop biofilm to persist in the nematode intestine until being released into the insect hemolymph. These findings demonstrate how the symbiotic bacteria reduce their …


Use Of Archive Aerial Photography For Monitoring Black Mangrove Populations, James H. Everitt, C. Yang, Frank W. Judd, Kenneth R. Summy Jul 2010

Use Of Archive Aerial Photography For Monitoring Black Mangrove Populations, James H. Everitt, C. Yang, Frank W. Judd, Kenneth R. Summy

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

A study was conducted on the South Texas Gulf Coast to evaluate archive aerial color-infrared (CIR) photography combined with supervised image analysis techniques to quantify changes in black mangrove [Avicennia germinans (L.) L.] populations over a 26-year period. Archive CIR film from two study sites (sites 1 and 2) was studied. Photographs of site 1 from 1976,1988, and 2002 showed that black mangrove populations made up 16.2%, 21.1%, and 29.4% of the study site, respectively. Photographs of site 2 from 1976 and 2002 showed that black mangrove populations made up 0.4% and 2.7% of the study site, respectively. Over the …


Ethnobotanical History And Seed Oil Chemistry Of The Physic Nut, Jatropha Curcas, Nathan M. Leclear May 2010

Ethnobotanical History And Seed Oil Chemistry Of The Physic Nut, Jatropha Curcas, Nathan M. Leclear

Theses and Dissertations - UTB/UTPA

Jatropha curcas L., Euphorbiaceae, is a small tree native to the neotropics. Despite renewed economic interests in Physic Nut, mainly for biodiesel production, a comprehensive analysis of the ethnobotanical history of J. curcas is lacking. An account of the pre-Columbian neotropical distribution of this species and its historical uses are presented. Using capillary gas chromatography, studies were conducted to quantify the natural variation in seed oil content and fatty acid composition of the seed oil from several species of Jatropha, including assessment of how these parameters change during seed maturation. Natural variation in seed oil content was detected (F7,93 = …


Does The Manipulation Of Tail Position Facilitate Extinction Of Canine Phobic Behavior?, Rebecca A. Zarate May 2010

Does The Manipulation Of Tail Position Facilitate Extinction Of Canine Phobic Behavior?, Rebecca A. Zarate

Theses and Dissertations - UTB/UTPA

The phobic behavior of interest is tail tucking which is indicative of submission. In this study the tail was physically manipulated by the use of a custom made harness to hold the tail up in a dominant position to ideally extinguish phobic behavior through reciprocal inhibition. The harness did not hold the tail up the entire duration of the interventions, although it still held the base of the tail up. The intervention did not appear to have an affect on the two of the five subjects. The three more phobic canines did display some behavioral changes, although the changes noticed …


Bronzed Cowbird (Molothrus Aeneus) Habitat Use And Differential Response To Playback Of Host Song, Mary Jennifer Gorton May 2010

Bronzed Cowbird (Molothrus Aeneus) Habitat Use And Differential Response To Playback Of Host Song, Mary Jennifer Gorton

Theses and Dissertations - UTB/UTPA

During the breeding seasons of 2008 - 2009, 180 fixed-radius point-count surveys and broadcasts of host song were conducted in Santa Ana (SANWR) and Laguna Atascosa (LANWR, 2009 only) National Wildlife Refuges to identify Bronzed Cowbird (Molothrus aeneus) habitat use and test the predictions of the host activity hypothesis. Surveys demonstrated that Bronzed Cowbirds were distributed across all habitat types in both refuges, although there were differences in abundance between the sexes for interior and edge habitats and between habitat types. Bronzed Cowbirds responded differentially to host species playbacks based on suitability and abundance of the host species. The results …


Dna Staged Self-Assembly At Temperature 1, Nicholas H. Guiterrez May 2010

Dna Staged Self-Assembly At Temperature 1, Nicholas H. Guiterrez

Theses and Dissertations - UTB/UTPA

We introduce alternate temperature 1 self-assembly constructions of an n x n square by efficiently utilizing bins and stages to achieve desirable results. These bins are able to contain a variety of tiles or supertiles, which are then mixed together in a pre-determined sequence of distinct stages. The basic 2D tile assembly model at temperature 1 uses 2n-1 tile types to construct a square. The model only utilizes one bin and occurs all in one stage. We will demonstrate how the use of bins and stages will allow for the construction of these squares more efficiently.


Do Decapod Crustaceans Have Nociceptors For Extreme Ph?, Sakshi Puri, Zen Faulkes Apr 2010

Do Decapod Crustaceans Have Nociceptors For Extreme Ph?, Sakshi Puri, Zen Faulkes

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

Background: Nociception is the physiological detection of noxious stimuli. Because of its obvious importance, nociception is expected to be widespread across animal taxa and to trigger robust behaviours reliably. Nociception in invertebrates, such as crustaceans, is poorly studied.

Methodology/Principal Findings: Three decapod crustacean species were tested for nociceptive behaviour: Louisiana red swamp crayfish (Procambarus clarkii), white shrimp (Litopenaeus setiferus), and grass shrimp (Palaemonetes sp.). Applying sodium hydroxide, hydrochloric acid, or benzocaine to the antennae caused no change in behaviour in the three species compared to controls. Animals did not groom the stimulated antenna, and there was no difference in movement …


Parity-Induced Decrease In Systemic Growth Hormone Alters Mammary Gland Signaling: A Potential Role In Pregnancy Protection From Breast Cancer, Robert K. Dearth, David A. Delgado, Jill K. Hiney, Thushangi Pathiraja, Steffi Oesterreich, Dan Medina, W. Les Dees, Adrian V. Lee Mar 2010

Parity-Induced Decrease In Systemic Growth Hormone Alters Mammary Gland Signaling: A Potential Role In Pregnancy Protection From Breast Cancer, Robert K. Dearth, David A. Delgado, Jill K. Hiney, Thushangi Pathiraja, Steffi Oesterreich, Dan Medina, W. Les Dees, Adrian V. Lee

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

Early full-term pregnancy is an effective natural protection against breast cancer in both humans and experimental rodents. The protective effect of an early pregnancy is in part linked to changes in circulating hormones that are involved in both normal breast development and breast cancer. For example, a reduction in circulating growth hormone (GH) has been shown to protect rats from carcinogen-induced mammary tumors. We examined the ability of a full-term pregnancy to alter the endocrine GH/IGF-I axis and how this change affected normal mammary gland function in two commonly used rat models (Sprague-Dawley and Wistar-Furth). Circulating GH and IGF-I were …


Are Beaches' Suitability As Sand Crab Habitat Affected By Human Recreation?, Jessica H. Murph, Zen Faulkes Mar 2010

Are Beaches' Suitability As Sand Crab Habitat Affected By Human Recreation?, Jessica H. Murph, Zen Faulkes

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

METHODS We compared the populations of sand crabs (Lepidopa benedicti, family Albuneidae) at two locations on the popular tourist destination South Padre Island: one which is reasonably developed, having many hotels and restaurants and one which is not so developed, at a more northern point on the island. At each site, 10 m transects were dug starting at the top of the swash zone (parallel to the surf). Each shovel of sand were carefully sifted. The carapace length, sex, color, and reproductive status of each sand crab found were recorded on site. Samples were collected regularly from August 2009 to …


Molecular Cloning And Characterization Of Cdnas Encoding Metalloproteinases From Snake Venom Glands, Ying Jia, John C. Perez Mar 2010

Molecular Cloning And Characterization Of Cdnas Encoding Metalloproteinases From Snake Venom Glands, Ying Jia, John C. Perez

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

Snake venom metalloproteinases (SVMPs) are a superfamily of zinc-dependent proteases and participate in a number of important biological, physiological and pathophysiological processes. In this work, we simultaneously amplified 9 cDNAs encoding different classes of metalloproteinases from glands of four different snake species (Agkistrodon contortrix laticinctus, Crotalus atrox, Crotalus viridis viridis and Agkistrodon piscivorus leucostoma) by RT-PCR with a pair of primers. Among the encoded metalloproteinases, two enzymes (AclVMP-I and AplVMP-I), three enzymes (CaVMP-II, CvvVMP-II and AplVMP-II) and four enzymes (AclVMP-III, CaVMP-III, CvvVMP-III and AplVMP-III) …


The Spread Of The Parthenogenetic Marbled Crayfish, Marmorkrebs (Procambarus Sp.), In The North American Pet Trade, Zen Faulkes Jan 2010

The Spread Of The Parthenogenetic Marbled Crayfish, Marmorkrebs (Procambarus Sp.), In The North American Pet Trade, Zen Faulkes

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

The parthenogenetic marbled crayfish Marmorkrebs was discovered in the pet trade in Europe in the 1990s. Since then, its distribution through the pet trade has spread from Europe to other continents, including North America. North American pet owners were surveyed online with the aims of trying to track when Marmorkrebs entered the North American pet trade, the ways in which it spread through the pet trade, and how widely distributed Marmorkrebs are throughout the continent. Marmorkrebs have been in the North American pet trade since at least 2004, with the number of people increasing every year. While many Marmorkrebs are …


Common Algogenic Chemicals Do Not Cause Nociceptive Responses In Louisiana Red Swamp Crayfish (Procambarus Clarkii), Sakshi Puri, Zen Faulkes Jan 2010

Common Algogenic Chemicals Do Not Cause Nociceptive Responses In Louisiana Red Swamp Crayfish (Procambarus Clarkii), Sakshi Puri, Zen Faulkes

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

Do crustaceans feel pain? This is hard to answer, because pain is complicated. A more tractable question is whether crustaceans have nociceptors: neurons specialized to detect tissue damage.

Algogenic chemicals bind to nociceptors and cause them to fire, often causing pain without tissue damage. For example, capsaicin is the algogenic chemical that makes peppers spicy; isothiocyanate is the chemical that makes wasabi pungent. Both can cause nociceptive responses in some invertebrates (capsaicin: Pastor et al. 1996, Wittenburg & Baumeister 1999, isothiocyanate: Al-Anzi et al. 2006).


Factors Affecting The Spatial Distribution Of Black Mangrove On The Dredged-Material Or “Spoil” Islands In The Lower Laguna Madre Of Texas, Violet Yeager, Kenneth R. Summy, Frank W. Judd, Robert I. Lonard, Ruben A. Mazariegos, James H. Everitt, Michael R. Heep, Thomas Whelan Jan 2010

Factors Affecting The Spatial Distribution Of Black Mangrove On The Dredged-Material Or “Spoil” Islands In The Lower Laguna Madre Of Texas, Violet Yeager, Kenneth R. Summy, Frank W. Judd, Robert I. Lonard, Ruben A. Mazariegos, James H. Everitt, Michael R. Heep, Thomas Whelan

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

Research was conducted to evaluate the spatial distribution of black mangrove (Avicennia germinans) on the dredged-material or “spoil” islands of the Lower Laguna Madre of Texas. Aerial color-infrared (CIR) photographs revealed the presence of black mangrove stands on many of the islands located south of the Arroyo Colorado (a distributary of the Rio Grande which empties into the Laguna Madre), but failed to detect significant mangrove stands on islands located north of the Arroyo. Analysis of CIR photographs and supervised image classifications for individual islands suggested a concentration of black mangrove along western shorelines and relatively low interior areas of …


Detection Of Incipient Pest Infestations On Glasshouse Crops Using Multispectral Imagery And A Common Vegetation Index, Kenneth R. Summy, Christopher R. Little, James H. Everitt, Ruben A. Mazariegos, J. V. French, Mamoudou Setamou, Jesus Mata Jan 2010

Detection Of Incipient Pest Infestations On Glasshouse Crops Using Multispectral Imagery And A Common Vegetation Index, Kenneth R. Summy, Christopher R. Little, James H. Everitt, Ruben A. Mazariegos, J. V. French, Mamoudou Setamou, Jesus Mata

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

Research was conducted to evaluate the effectiveness of multispectral (conventional color and color infrared) imagery and a common vegetation index (simple ratio) for detecting incipient infestations of spider mites (Tetranychus spp.; Acari: Tetranychidae) and false spider mites (Brevipalpus spp.; Acari: Tenupalpidae) on selected crops under glasshouse conditions. Although damaging infestations of both mite species were associated with intense feeding injury which was readily detectable by visual inspection, subtle levels of foliar damage caused by the two mite species were difficult to detect by visual inspection and were not readily distinguishable from undamaged (healthy) foliage in conventional color (CC) or color …


Population Ecology And Reproductive Biology Of The Diamondback Watersnake, Nerodia Rhombifer (Serpentes: Colubridae), In Southernmost Texas, Ruben D. Zamora Dec 2009

Population Ecology And Reproductive Biology Of The Diamondback Watersnake, Nerodia Rhombifer (Serpentes: Colubridae), In Southernmost Texas, Ruben D. Zamora

Theses and Dissertations - UTB/UTPA

Nerodia rhombifer is a polytypic, semi-aquatic snake with a broad geographical distribution ranging from the American Midwest southward to Chiapas, Mexico. Although relatively abundant throughout much of its range, few ecological studies of the species have been conducted. This study provides basic population ecology information in a subtropical habitat. Population data were obtained in a mark-recapture study at Santa Ana National Wildlife Refuge, Hidalgo County, Texas, from August 1995 to December 1998. Specimens taken elsewhere in Hidalgo County provided information on the reproductive biology. This study provides the first absolute density estimates from anywhere within the species’ range. Quantitative information …


Age Comparisons Of Bone Density And Geometry In Men, Vanessa D. Sherk, Murat Karabulut, Michael G. Bemben, Debra A. Bemben Dec 2009

Age Comparisons Of Bone Density And Geometry In Men, Vanessa D. Sherk, Murat Karabulut, Michael G. Bemben, Debra A. Bemben

Health & Human Performance Faculty Publications

Objectives: The purposes of this study were to examine tibia bone density and geometry in young and middle aged men, and to explore relationships between pQCT- and DXA-derived body composition variables.

Methods: Healthy males (18-30 years old, n=31; 50-64 years old, n=37) had their total body areal bone mineral density (aBMD) and body composition measured with Dual Energy X-ray Absorptiometry (DXA). Volumetric bone characteristics, muscle cross-sectional area (MCSA) and fat cross-sectional area (FCSA) of the leg were measured with peripheral Quantitative Computed Tomography (pQCT).

Results: Young men were significantly (p<0.05) lighter and had less fat mass than older men. Total volumetric BMD (vBMD) at 66% of the tibia length was significantly lower (p<0.05) in older men. Bone-free lean body mass values were useful predictors of total and cortical area and content (R(2)=0.338-0.467). MCSA was more predictive of leg BFLBM than total body BFLBM, and those relationships were stronger in older men.

Conclusions: Differences in tibial bone area and density existed between …


Seasonality And Movement Of Adventive Populations Of The Arundo Wasp (Hymenoptera: Eurytomidae), A Biological Control Agent Of Giant Reed In The Lower Rio Grande Basin In South Texas, Alexis Racelis, Carol Goolsby, Patrick J. Moran Dec 2009

Seasonality And Movement Of Adventive Populations Of The Arundo Wasp (Hymenoptera: Eurytomidae), A Biological Control Agent Of Giant Reed In The Lower Rio Grande Basin In South Texas, Alexis Racelis, Carol Goolsby, Patrick J. Moran

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

The arundo wasp, Tetramesa romana Walker, has been permitted as a biological control agent for the invasive perennial grass, the giant reed, Arundo donax L. Evidence of adventive populations of the arundo wasp in the Lower Rio Grande Basin was confirmed with a spatio-temporal survey spanning more than 350 river miles. A total of 2,414 adult females of T. romana was collected during a 14month period of study in 2008–2009. This study documents the initial locations and regional expansion of two adventive populations of T. romana, centered around the cities of Eagle Pass and Laredo, TX. Peaks in T. …


Characterization Of Arsenic-Tolerant Bacterial Cultures From The Lower Laguna Madre Of South Texas, Gemma A. Berlanga, Michael W. Persans, Thomas Eubanks, Kristine L. Lowe Nov 2009

Characterization Of Arsenic-Tolerant Bacterial Cultures From The Lower Laguna Madre Of South Texas, Gemma A. Berlanga, Michael W. Persans, Thomas Eubanks, Kristine L. Lowe

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

Two forms of arsenic are found in the environment: As(V) and As(III), the latter being more toxic, water-soluble, and mobile. Microorganisms may increase the mobility of arsenic by reducing As(V) to As(III); however, detoxification and immobilization can occur via the oxidation of As(III) to As(V). The US EPA has set a minimum contaminant level of 10 parts per billion (ppb) for arsenic in drinking water. The research objective was to confirm the presence of arsenic-tolerant bacteria in the Lower Laguna Madre of south Texas. Sediment samples were collected and inoculated into growth media which contained either 2 mM As(III) or …


Endogenous N-3 Fatty Acids Protect Ovariectomy Induced Bone Loss By Attenuating Osteoclastogenesis, Md Mizanur Rahman, Arunabh Bhattacharya, Jameela Banu, Jing X. Kang, Gabriel Fernandes Oct 2009

Endogenous N-3 Fatty Acids Protect Ovariectomy Induced Bone Loss By Attenuating Osteoclastogenesis, Md Mizanur Rahman, Arunabh Bhattacharya, Jameela Banu, Jing X. Kang, Gabriel Fernandes

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

Beneficial effects of n-3 fatty acids (FA) on bone mineral density (BMD) have been reported in mice, rats and human beings, but the precise mechanisms involved have not been described. This study used the Fat-1 mouse, a transgenic model that synthesizes n-3 FA from n-6 FA to directly determine if outcome of bone health were correlated with n-3 FA. Ovariectomized (Ovx) and sham operated wild-type (WT) and Fat-1 mice were fed an AIN-93M diet containing 10% corn oil for 24 weeks. BMD was analysed by dual energy x-ray absorptiometry. Fat-1 Ovx mice exhibited significantly lower level of osteotropic factors like …


Indicadores Funcionales Y Estructurales Para Evaluar El Estado De Conservación De Humedales Costeros En El Sur De Tamaulipas, Alejandro Fierro-Cabo Sep 2009

Indicadores Funcionales Y Estructurales Para Evaluar El Estado De Conservación De Humedales Costeros En El Sur De Tamaulipas, Alejandro Fierro-Cabo

School of Earth, Environmental, & Marine Sciences Faculty Publications

El manejo adecuado de las zonas costeras requiere de herramientas que permitan detectar procesos degradantes en los ecosistemas estratégicos prestadores de servicios ambientales. Los indicadores ecológicos responden adecuadamente a esta necesidad en humedales costeros. Se estudiaron ocho humedales de origen y características distintas, con afectaciones contrastantes conocidas. Se seleccionaron los indicadores que mejor discriminaron los sitios y se utilizaron para evaluar la evolución del estado de conservación de los mismos. La correspondencia ecológica entre indicadores funcionales y estructurales no se confirmó en todos los casos, por lo que es necesario utilizar ambos tipos para obtener un mejor diagnóstico. En dicha …


Large-Scale Patterns In Trematode Richness And Infection Levels In Marine Crustacean Hosts, David W. Thieltges, Brian L. Fredensborg, Anja Studer, Robert Poulin Sep 2009

Large-Scale Patterns In Trematode Richness And Infection Levels In Marine Crustacean Hosts, David W. Thieltges, Brian L. Fredensborg, Anja Studer, Robert Poulin

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

Little is known about the patterns of variation in parasitism in marine hosts. Trematodes, the dominant parasites in intertidal systems, are transmitted from their first intermediate hosts (snails) to a range of second intermediate hosts, including crustaceans. Using published studies of trematode infections in crustacean hosts, we investigated general patterns of variation in trematode species richness and infection levels (i.e. percentage of hosts infected and mean number of individual parasites per host). Since the production and release of infective stages in snails is strongly temperature dependent, we also investigated a potential decrease in trematode infection levels with increasing latitude (as …


Cdna Cloning, Expression And Fibrin(Ogen)Olytic Activity Of Two Low-Molecular Weight Snake Venom Metalloproteinases, Ying Jia, Sara E. Lucena, Esteban Cantu, Elda E. Sánchez, John C. Perez Sep 2009

Cdna Cloning, Expression And Fibrin(Ogen)Olytic Activity Of Two Low-Molecular Weight Snake Venom Metalloproteinases, Ying Jia, Sara E. Lucena, Esteban Cantu, Elda E. Sánchez, John C. Perez

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

Two cDNA clones, AplVMP1 and AplVMP2, were isolated from a snake (Agkistrodon piscivorus leucostoma) venom gland cDNA library. The full-length cDNA sequence of AplVMP1 with a calculated molecular mass of 46.61 kDa is 1,233 bp in length. AplVMP1 encodes PI class metalloproteinase with an open reading frame of 411 amino acid residues that includes signal peptide, pro-domain and metalloproteinase domains. The full-length cDNA of the AplVMP2 (1,371bp) has a calculated molecular mass of 51.16 kDa and encodes PII class metalloproteinase. The open reading frame of AplVMP2 with a 457 amino acid residues is composed of signal peptide, pro-domain, …