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University of Texas Rio Grande Valley

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Articles 481 - 510 of 611

Full-Text Articles in Biology

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 …


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. …


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 …


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 …


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 …


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, …


Assessing Threat Of Introduction Of The Parthenogenetic Marbled Crayfish Marmorkrebs Into North American Waters, Stephanie A. Jimenez, Zen Faulkes Aug 2009

Assessing Threat Of Introduction Of The Parthenogenetic Marbled Crayfish Marmorkrebs Into North American Waters, Stephanie A. Jimenez, Zen Faulkes

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

Background/Question/Methods

Marmorkrebs are parthogenetic crayfish in the genus Procambarus. Their provenance is unknown, but they were discovered in hobbyists' aquaria in Germany in the mid 1990s, and have since been introduced into the North American pet trade. Marmorkrebs are a potential invasive pest species. For example, they have already been introduced into Madagascar, where they may threaten endemic crayfish species. We are trying to estimate the risk, and possible consequences, of any accidental introduction of Marmorkrebs into North American waters. First, we conducted an online survey of hobbyists who keep Marmorkrebs as pets to estimate how widely, and how …


The Influence Of Environmental Factors On The Activity And Movement Of Bufo Nebulifer (Coastal Plain Toad) In A Disturbed Area, Crystal Salinas Jul 2009

The Influence Of Environmental Factors On The Activity And Movement Of Bufo Nebulifer (Coastal Plain Toad) In A Disturbed Area, Crystal Salinas

Theses and Dissertations - UTB/UTPA

Toads in the family Bufonidae are poorly studied in southern Texas. Bufo nebulifir, a native bufonid, has been studied in its northern and southern range limits (east Texas and northern Mexico). South Texas' sub-tropical climate could impact the length of the activity period for B. nebulifer in yet unrecorded ways. This study resolves whether environmental factors correlate to Bufo nebulifer's activity, presence, and movement, using a mark-recapture method. The study was conducted for one year during February 2008 to March 2009. Environmental factors, especially rainfall and temperature were significantly correlated (PB. nebulifer . The active period of B. …


Genetic And Phenotypic Characterization Of Plant Pathogen Inhibitory Streptomyces Isolates, Uylissa A. Rodriguez Jul 2009

Genetic And Phenotypic Characterization Of Plant Pathogen Inhibitory Streptomyces Isolates, Uylissa A. Rodriguez

Theses and Dissertations - UTB/UTPA

Streptomyces are Gram-positive, filamentous bacteria that are readily isolated from soil and produce diverse secondary metabolites such as pigments and antibiotics. A survey of indigenous soil microbes from Rio Grande Valley agricultural soils revealed several isolates with broad inhibitory abilities against a range of soil-borne plant pathogens. The goal of this study was to characterize eleven of these potential biocontrol isolates both biochemically and genetically. Nutrient utilization profiles, 16S rDNA sequencing, and the presence of genes involved in antibiotic biosynthesis pathways (strBl, strR, strF, strN, strS and KS) on plasmids or the chromosome were investigated. Nutrient utilization profiling revealed that …


Stress Responses To Salinity In A Native Fresh Water Snake (Nerodia Rhombifer), Joana A. Cordoba May 2009

Stress Responses To Salinity In A Native Fresh Water Snake (Nerodia Rhombifer), Joana A. Cordoba

Theses and Dissertations - UTB/UTPA

Salinity stress at 0 ppt, 9 ppt, 18 ppt, and 27 ppt was investigated in Nerodia rhombifer, a fresh water snake. The purpose of this study was to establish if exposure to salinity could elicit a hormonal response in the form of corticosterone. Salinity treatment 27 ppt was lethal for 50% of the snakes. Factors such as population and gender differences were not significant, p=0.748 and p=0.135, respectively. Exposure to the different salinities did not significantly affect the overall mass of the animal, p=0.951. A significant increase in circulating corticosterone was noted in salinity treatments 0 ppt and 18 ppt, …


Range Expansions And New Breeding Records Of Birds In Tamaulipas, Mexico, Timothy Brush Mar 2009

Range Expansions And New Breeding Records Of Birds In Tamaulipas, Mexico, Timothy Brush

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

Breeding birds of riparian forests and other habitats in the Ciudad Victoria area were studied, mainly in June 2003 and 2006. Olivaceous woodcreeper (Sittasomus griseicapillus), mangrove swallow (Tachycineta albilinea), and scrub euphonia (Euphonia affinis; nesting) extended their range north to the Ciudad Victoria area. Western kingbird (Tyrannus verticalis) nested for the first time in Tamaulipas and occurred south to the Ciudad Victoria area, and European starlings (Sturnus vulgaris) nested in south-central Tamaulipas for the first time. Great curassow (Crax rubra) and crested guan (Penelope purpurascens) were rediscovered in the Ciudad Victoria area for the first time since 1909. Distributions of …


Observations Of Flotsam Entrapment In The Northern Diamond-Backed Watersnake (Nerodia R. Rhombifer), Jason Ortega, Frederic Zaidan Feb 2009

Observations Of Flotsam Entrapment In The Northern Diamond-Backed Watersnake (Nerodia R. Rhombifer), Jason Ortega, Frederic Zaidan

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

—Small areas of protected land may act as islands of suitable habitat surrounded by human development. Although these areas receive protection, we have observed one way that the surrounding human population can still endanger the welfare of its inhabitants. During our observations of the Northern Diamond-backed Watersnake (Nerodia r. rhombifer) in a semi-protected nature park surrounded by human development, we encountered 13 individuals entangled with flotsam. Of the 220 juvenile through adult snakes that we captured, 12 were encircled by various types of objects (e.g., finger cots; latex sheaths that cover a single digit, dental elastics, and plastic bottle neck …


Establishment Of A Research Colony Of Marmorkrebs, A Parthenogenetic Crayfish Species, Stephanie A. Jimenez, Zen Faulkes Feb 2009

Establishment Of A Research Colony Of Marmorkrebs, A Parthenogenetic Crayfish Species, Stephanie A. Jimenez, Zen Faulkes

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

Marmorkrebs, or marbled crayfish, are recently discovered parthenogenetic crayfish. Its origins are unknown, but it has been introduced into natural ecosystems and could become a highly invasive pest species. Marmorkrebs have potential as a model organism for research in many biological fields because they are genetically uniform. A key element of most successful model organisms is maintaining self-sustaining breeding colonies. We report on our efforts find the best conditions for establishing and maintaining a Marmorkrebs breeding colony for research. The colony was founded by four adults of unknown age (P generation). These foundresses were housed communally in standard aquaria and …


Spectral Reflectance And Digital Image Relations Among Five Aquatic Weeds, James H. Everitt, Kenneth R. Summy, Chenghai Yang Jan 2009

Spectral Reflectance And Digital Image Relations Among Five Aquatic Weeds, James H. Everitt, Kenneth R. Summy, Chenghai Yang

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

This study reports on the use of an artificial quartz halogen lighting source to facilitate the acquisition of spectral light reflectance measurements and digital imaging of invasive aquatic weeds. Spectral leaf or leaf/stem reflectance measurements were made on five aquatic weeds: Eurasian watermilfoil (Myriophyllum spicatum L.), hydrilla [Hydrilla verticillata (L. F.) Royle], parrotfeather [Myriophyllum aquaticum (Vall.), waterhyacinth [Eichhornia crassipes (Mart.) Solms], and waterlettuce (Pistia stratiotes L.). Reflectance measurements were studied at five wavelengths of the electromagnetic spectrum: 450 nm (visible blue), 550 nm (visible green), 650 nm (visible red), 680 nm (visible red edge), and 850 nm (near-infrared). Reflectance values …


Comparison Of Leaf-Clipping And Leaf-Piercing Techniques As Applied To The Seagrass Syringodium Filiforme, Joseph L. Kowalski, Hudson R. Deyoe, Christian P. Krull, Terry C. Allison Jan 2009

Comparison Of Leaf-Clipping And Leaf-Piercing Techniques As Applied To The Seagrass Syringodium Filiforme, Joseph L. Kowalski, Hudson R. Deyoe, Christian P. Krull, Terry C. Allison

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

Leaf elongation rates of the seagrass Syringodium filiforme (Kütz., 1860) were assessed at two sites in a subtropical lagoon of Texas on eleven occasions from January 1996 to April 1997 using two methods, clipping and leaf piercing (marking) to estimate leaf growth. Pierced shoots grew at a significantly faster rate than clipped shoots irrespective of site. Clipping underestimated leaf elongation by 30%–38%, although differences at individual sites were as high as 69%–72%. Underestimation of leaf growth rate derived by clipping could be corrected using a site-specific linear regression relationship between leaf growth rates determined by clipping and piercing methods. The …


Tournefortia Hirsutissima (Boraginaceae) New To The Flora Of Texas, Alfred Richardson, Ken King Jan 2009

Tournefortia Hirsutissima (Boraginaceae) New To The Flora Of Texas, Alfred Richardson, Ken King

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

Toumefortia hirsutissima (Boraginaceae) is reported for extreme south Texas, a new record for the state of Texas.

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Toumefortia hirsutlssima (Boraginaceae) se cita de! extremo sur de Tejas, es el primer registro para el estado de Tejas.