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University of Texas Rio Grande Valley

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Articles 1231 - 1260 of 1826

Full-Text Articles in Life Sciences

Molecular Comparison Of Cattle Fever Ticks From Native And Introduced Ranges, With Insights Into Optimal Search Areas For Classical Biological Control Agents, John A. Goolsby, F. D. Guerrero, John F. Gaskin, K. G. Bendele, P. Azhahianambi, D. Amalin, M. Flores-Cruz, J. Kashefi, Alexis Racelis Sep 2016

Molecular Comparison Of Cattle Fever Ticks From Native And Introduced Ranges, With Insights Into Optimal Search Areas For Classical Biological Control Agents, John A. Goolsby, F. D. Guerrero, John F. Gaskin, K. G. Bendele, P. Azhahianambi, D. Amalin, M. Flores-Cruz, J. Kashefi, Alexis Racelis

School of Earth, Environmental, & Marine Sciences Faculty Publications

Cattle fever ticks, the southern cattle tick, Rhipicephalus microplus (Canestrini), and cattle tick, Rhipicephalus annulatus (Say), are livestock pests endemic to Mexico and invasive along the Texas-Mexico border. Resistance to acaricide, alternate wildlife hosts, and pathogenic landscape-forming weeds present challenges for sustainable eradication of this pest in the U.S. Classical biological control is being explored as a strategy to control cattle fever ticks, especially on alternate hosts such as nilgai antelope, Boselaphus tragocamelus (Pallas), and white-tailed deer, Odocoileus virginianus (Zimmermann). Molecular genetic tools were used to compare populations of cattle fever ticks from native and introduced ranges to provide insights …


The Late Quaternary Rio Grande Delta—A Distinctive, Underappreciated Geologic System, Thomas E. Ewing, Juan L. Gonzalez Sep 2016

The Late Quaternary Rio Grande Delta—A Distinctive, Underappreciated Geologic System, Thomas E. Ewing, Juan L. Gonzalez

School of Earth, Environmental, & Marine Sciences Faculty Publications

The delta of the Rio Grande/Rio Bravo in southernmost Texas and northern Tamaulipas is one of the major deltas of North America. Over 600,000 people live on the Holocene delta and river plain, and a million more on its Pleistocene ancestors, yet geo-logic knowledge is limited. Combining available geologic information with global satellite photography gives a balanced view of an important delta. The Holocene delta begins at a point west of San Benito, Texas, forming a classic eastward-opening delta. Over half of the delta lies south of the present Rio Grande drainage. The delta passes westward into a floodplain that …


Expert Elicitation On The Uncertainties Associated With Chronic Wasting Disease, Michael G. Tyshenko, Tamer Oraby, Shalu Darshan, Margit Westphal, Maxine C. Croteau, Willy Aspinall, Susie Elsaadany, Daniel Krewski, Neil Cashman Aug 2016

Expert Elicitation On The Uncertainties Associated With Chronic Wasting Disease, Michael G. Tyshenko, Tamer Oraby, Shalu Darshan, Margit Westphal, Maxine C. Croteau, Willy Aspinall, Susie Elsaadany, Daniel Krewski, Neil Cashman

School of Mathematical & Statistical Sciences Faculty Publications

A high degree of uncertainty exists for chronic wasting disease (CWD) transmission factors in farmed and wild cervids. Evaluating the factors is important as it helps to inform future risk management strategies. Expert opinion is often used to assist decision making in a number of health, science, and technology domains where data may be sparse or missing. Using the "Classical Model" of elicitation, a group of experts was asked to estimate the most likely values for several risk factors affecting CWD transmission. The formalized expert elicitation helped structure the issues and hence provide a rational basis for estimating some transmission …


Analysis Of Protein-Coding Genetic Variation In 60,706 Humans, Monkol Lek, Konrad J. Karczewski, Eric V. Minikel, Kaitlin E. Samocha, Eric Banks, Timothy Fennell, Anne H. O'Donnell-Luria, James S. Ware, Andrew J. Hill, John Blangero Aug 2016

Analysis Of Protein-Coding Genetic Variation In 60,706 Humans, Monkol Lek, Konrad J. Karczewski, Eric V. Minikel, Kaitlin E. Samocha, Eric Banks, Timothy Fennell, Anne H. O'Donnell-Luria, James S. Ware, Andrew J. Hill, John Blangero

Human Genetics Publications

Large-scale reference data sets of human genetic variation are critical for the medical and functional interpretation of DNA sequence changes. Here we describe the aggregation and analysis of high-quality exome (protein-coding region) DNA sequence data for 60,706 individuals of diverse ancestries generated as part of the Exome Aggregation Consortium (ExAC). This catalogue of human genetic diversity contains an average of one variant every eight bases of the exome, and provides direct evidence for the presence of widespread mutational recurrence. We have used this catalogue to calculate objective metrics of pathogenicity for sequence variants, and to identify genes subject to strong …


Characterizing Mesophotic Reef Fish Communities At Five South Texas Relic Coral-Algal Banks, Linda Marie Jordan Aug 2016

Characterizing Mesophotic Reef Fish Communities At Five South Texas Relic Coral-Algal Banks, Linda Marie Jordan

Theses and Dissertations

The South Texas Banks are a mesophotic coral ecosystem (30-150m deep). Understanding the community structure, biodiversity and, geographic connectivity of the South Texas Banks is essential with increasing threats from climate change, ocean acidification, invasive species, and pollution. In this study, a remotely operated vehicle (ROV) was used to examine the fish communities at five of the South Texas Banks: Big Adam, Hospital, Mysterious, North Hospital, and Southern. Reef fish were identified to the lowest possible taxon and enumerated from ROV transect video footage. A total of 3,838 demersal and pelagic fishes were recorded representing 61 species in 22 families …


South Padre Island Beach Management: Assessment Of Dune Restoration, Shelby Rose Bessette Aug 2016

South Padre Island Beach Management: Assessment Of Dune Restoration, Shelby Rose Bessette

Theses and Dissertations

Dune restoration is a common method of increasing coastal resilience. A dune restoration program was initiated by the City of South Padre Island, TX in 2010 consisting primarily of plantings of Sea Oats, Uniola paniculata, and Bitter Panicum, Panicum amarum and has continued approximately annually thereafter. These restoration efforts were evaluated in this study by comparing dune ecological structure and function among reference sites and restoration plots ranging in age from 2 to 5 years. Plant and animal communities were examined using a combination of quadrat sampling, funnel traps, pit-falls and sweep nets. Soil organic content and soil electric …


The Effect Of Manganese (Mn) On Cell Proliferation And Migration In The Michigan Cancer Foundation-7 (Mcf-7) Human Breast Cancer Cell Line In Vitro, Justin Lloyd Wendel Aug 2016

The Effect Of Manganese (Mn) On Cell Proliferation And Migration In The Michigan Cancer Foundation-7 (Mcf-7) Human Breast Cancer Cell Line In Vitro, Justin Lloyd Wendel

Theses and Dissertations

Manganese (Mn) is a common environmental element necessary for mammalian physiological processes. However, dietary excess or deficiency can lead to detrimental health effects. Therefore, I investigated the effect Mn has on breast cancer progression in vitro. Utilizing MCF-7 breast cancer cells an MTT assay was performed to identify proliferative potential. After 5 days, results showed 100 nM manganese chloride (MnCl2) had a significant (p<0.01) increase in cell number over control. Using a scratch wound-healing assay, 100 nM MnCl2 was found to increase cellular motility as well as induce a possible change in morphology and cytoskeletal organization. Given Mn was shown to localize in the mitochondrial, we investigated Mn-induced ROS expression. 500 nM Mn significantly decreased (p<0.05) ROS levels. Collectively, I provide evidence that Mn may potentially drive less aggressive cancer cells towards a more invasive phenotype.


Manganese-Reducing Bacterial Communities From A Hypersaline Estuary In South Texas Under Conditions Of Changing Salinity, Omar R. Elizondo, Rebecca Vasquez Villarreal, Sonia Y. Del Rio, Kristine L. Lowe Aug 2016

Manganese-Reducing Bacterial Communities From A Hypersaline Estuary In South Texas Under Conditions Of Changing Salinity, Omar R. Elizondo, Rebecca Vasquez Villarreal, Sonia Y. Del Rio, Kristine L. Lowe

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

Manganese reducing bacteria were quantified and enriched from sediments at two sites (ABC and LMT050) in the Laguna Madre of South Texas. Bacteria were tested for Mn(IV) reduction under different salinities. Denaturing gradient gel electrophoresis (DGGE) was used to profile bacterial communities from Mn(IV) saline enrichments. Results showed that the density of manganese reducing bacteria at ABC was 30X greater than LMT050. The ABC bacteria were able to reduce Mn(IV) at similar rates at different salinities; however, at LMT050, Mn(IV) reduction rates decreased at higher salinities. Three population genotypes were observed by DGGE. All were present and similarly abundant in …


Assessment Of Indoor And Outdoor Pm Species At Schools And Residences In A High-Altitude Ecuadorian Urban Center, Amit U. Raysoni, Rodrigo X. Armijos, M. Margaret Weigel, Teresa Montoya, Patricia Eschanique, Marcia Racines, Wen-Whai Li Jul 2016

Assessment Of Indoor And Outdoor Pm Species At Schools And Residences In A High-Altitude Ecuadorian Urban Center, Amit U. Raysoni, Rodrigo X. Armijos, M. Margaret Weigel, Teresa Montoya, Patricia Eschanique, Marcia Racines, Wen-Whai Li

School of Earth, Environmental, & Marine Sciences Faculty Publications

An air monitoring campaign to assess children’s environmental exposures in schools and residences, both indoors and outdoors, was conducted in 2010 in three low-income neighborhoods in Z1(north), Z2(central), and Z3(southeast) zones of Quito, Ecuador - a major urban center of 2.2 million inhabitants situated 2850 meters above sea level in a narrow mountainous basin. Z1 zone, located in northern Quito, historically experienced emissions from quarries and moderate traffic. Z2 zone was influenced by heavy traffic in contrast to Z3 zone which experienced low traffic densities. Weekly averages of PM samples were collected at schools (one in each zone) and residences …


Do Some Deep‐Sea, Sediment‐Dwelling Species Of Harpacticoid Copepods Have 1000‐Km‐Scale Range Sizes?, Erin E. Easton, David Thistle Jun 2016

Do Some Deep‐Sea, Sediment‐Dwelling Species Of Harpacticoid Copepods Have 1000‐Km‐Scale Range Sizes?, Erin E. Easton, David Thistle

School of Earth, Environmental, & Marine Sciences Faculty Publications

The range sizes of sediment‐dwelling deep‐sea species are largely unknown. Such knowledge is important because a deep sea composed in large part of species with 100‐km‐scale ranges would be very different from one composed predominantly of species with 1000‐km‐scale ranges. For example, the total species richness would be much greater in the first case than in the second. As a step towards the determination of the distribution of species’ range sizes in the deep sea, we asked whether harpacticoid copepods (Crustacea) on the continental rise in the northeastern Pacific had 1000‐km‐scale range sizes. We chose harpacticoids because they occur widely …


Nesting Ecology Of The Northern Beardless-Tyrannulet (Camptostoma Imberbe) In The Lower Rio Grande Valley Of Texas, Usa, Scott M. Werner, Sallie J. Hejl, Timothy Brush Jun 2016

Nesting Ecology Of The Northern Beardless-Tyrannulet (Camptostoma Imberbe) In The Lower Rio Grande Valley Of Texas, Usa, Scott M. Werner, Sallie J. Hejl, Timothy Brush

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

During 2002–2003, we studied the breeding ecology of the Northern Beardless-Tyrannulet (Camptostoma imberbe), a poorly known and rare permanent resident in the Lower Rio Grande Valley of Texas, United States of America. We found 28 nests in clusters of Spanish moss (Tillandsia usneoides) or ball moss (T. recurvata), 93% of which were in cedar elm (Ulmus crassifolia) trees. Nest-building, incubation, and nestling periods averaged 7.0, 14.0, and 18.5 days, respectively. Of the 28 nests, 43% were successful, while 38% of the failed nests showed obvious signs of depredation. Nests were located in …


A National Strategy For The Conservation Of Native Freshwater Mollusks, Megan Bradley, Robert S. Butler, Heidi L. Dunn, Catherine Gatenby, Patricia A. Morrison, Teresa J. Newton, Matthew Patterson, Kathryn E. Perez May 2016

A National Strategy For The Conservation Of Native Freshwater Mollusks, Megan Bradley, Robert S. Butler, Heidi L. Dunn, Catherine Gatenby, Patricia A. Morrison, Teresa J. Newton, Matthew Patterson, Kathryn E. Perez

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

In 1998, a strategy document outlining the most pressing issues facing the conservation of freshwater mussels was published (NNMCC 1998). Beginning in 2011, the Freshwater Mollusk Conservation Society began updating that strategy, including broadening the scope to include freshwater snails. Although both strategy documents contained 10 issues that were deemed priorities for mollusk conservation, the identity of these issues has changed. For example, some issues (e.g., controlling dreissenid mussels, technology to propagate and reintroduce mussels, techniques to translocate adult mussels) were identified in the 1998 strategy, but are less prominent in the revised strategy, due to changing priorities and progress …


Relationships Between Texas Tortoise Carapace Length, Home Range Size, And Habitat Selection At Sites With Invasive Grass, Kiley V. Briggs May 2016

Relationships Between Texas Tortoise Carapace Length, Home Range Size, And Habitat Selection At Sites With Invasive Grass, Kiley V. Briggs

Theses and Dissertations

Invasive grasses in south Texas have the potential to negatively impact the threatened Texas tortoise (Gopherus berlandieri) by reducing the availability of preferred foods (forbs) and may cause tortoises to travel farther, lead to reduced carapace length, and reduce the availability of refugia from heat stress. I used compositional analysis, regression, and ANOVA to explore relationships between invasive grasses and habitat use, home range size, and carapace length, as well as compared daily maximum temperatures between tussocks of an invasive and native grass. Forbs were ranked higher in use over invasive grasses in compositional analysis, but not strongly so (p …


Apoptotic And Necrotizing Mechanisms Of Recombinant Panton-Valentine Leukocidin In Thp1 Monocytes., Heriberto Deleon Iii May 2016

Apoptotic And Necrotizing Mechanisms Of Recombinant Panton-Valentine Leukocidin In Thp1 Monocytes., Heriberto Deleon Iii

Theses and Dissertations

The Panton-Valentine Leukocidin (PVL) is a highly specialized bacterial exotoxin produced by Staphylococcus aureus. The increased degree of invasiveness of community associated methicillin resistant Staphylococcus aureus (CAMRSA) has been attributed to the relatively high rates of PVL produced by the pathogen, thus increasing pathogenicity and virulence. The increased rates of PVL encoding CAMRSA infections have been correlated with increased rates of necrotizing fasciitis, invasive osteomyelitis and invasive necrotizing pneumococcal infections. Previous research as revealed that PVL has the ability to induce apoptosis at low concentration (5nM-10nM) and necrosis (50-100nM) at high concentrations, with little detail on the mechanism of initiation. …


Elementary Educators' Perspective Of Physical Education And The Physical Education Teacher, Jennifer M. Garcia May 2016

Elementary Educators' Perspective Of Physical Education And The Physical Education Teacher, Jennifer M. Garcia

Theses and Dissertations

Physical education continues to have the reputation it has had for years of being a subject of marginalization and of least importance in the school curriculum. The purpose of this study is to gain a better understanding of the perceptions of educators of physical education and the physical education teacher in the Rio Grande Valley. The researcher attempts to find, understand, and describe the perceptions of the educator’s view of this subject matter. Statistical significance was set at the .05 level for both tests of analyses. The researcher offers the null hypothesis of no difference between educator’s perception of PE …


Jatropha Curcas Protoplast Isolation And Inhibitory Effects Of Culture, Christopher S. Lukaszewski May 2016

Jatropha Curcas Protoplast Isolation And Inhibitory Effects Of Culture, Christopher S. Lukaszewski

Theses and Dissertations

Improvement on the sub-tropical plant Jatropha curcas may increase the use of this drought tolerant oilseed crop for the production of biodiesel. One of the methods for enhancing a species is through genetic manipulation of the protoplast. Isolating protoplasts is challenging and culturing has many obstacles similar to those seen in tissue culture, such as oxidative browning. Successful isolation of J. curcas leaf protoplasts resulted in an average of 3.23 x 106 viable protoplasts/mL. However, protoplasts diminished within 2 days after culturing. A review of the potential solutions used for overcoming the inhibitory effects of culture may reveal further insight …


Potential And Timescales For Oxygen Depletion In Coastal Upwelling Systems: A Box-Model Analysis, Cheryl S. Harrison, B. Hales, S. Siedlecki, R. M. Samelson May 2016

Potential And Timescales For Oxygen Depletion In Coastal Upwelling Systems: A Box-Model Analysis, Cheryl S. Harrison, B. Hales, S. Siedlecki, R. M. Samelson

School of Earth, Environmental, & Marine Sciences Faculty Publications

A simple box model is used to examine oxygen depletion in an idealized ocean-margin upwelling system. Near-bottom oxygen depletion is controlled by a competition between flushing with oxygenated offshore source waters and respiration of particulate organic matter produced near the surface and retained near the bottom. Upwelling-supplied nutrients are consumed in the surface box, and some surface particles sink to the bottom where they respire, consuming oxygen. Steady states characterize the potential for hypoxic near-bottom oxygen depletion; this potential is greatest for faster sinking rates, and largely independent of production timescales except in that faster production allows faster sinking. Timescales …


Characterizing Benthic Invertebrate Communities At Five South Texas Banks, Maria T. Cooksey May 2016

Characterizing Benthic Invertebrate Communities At Five South Texas Banks, Maria T. Cooksey

Theses and Dissertations

On the continental shelf off the coast of South Texas lie a series of hardbottom structures known as the South Texas Banks, which provide critical habitat for benthic organisms and pelagic fish species. The depth of the banks, a persistent nepheloid layer, and strong currents have hindered efforts to collect quantitative data on what inhabits the rocky outcrops and relic coral-algal reefs. Using a remotely operated vehicle, video data from five of the banks were collected in order to characterize the benthic communities. Southern and North Hospital Banks were found to be the most diverse of the studied South Texas …


The Acute Effects Of Aerobic Exercise With Blood Flow Restriction Cuffs On Arterial Compliance In Males And Females, Maria M. Gonzalez May 2016

The Acute Effects Of Aerobic Exercise With Blood Flow Restriction Cuffs On Arterial Compliance In Males And Females, Maria M. Gonzalez

Theses and Dissertations

RESULTS: Significant condition*gender interactions found in in SBP (p<.05), PR (p<.01), SVR (p<.01), SpO2 (p<.05), PWV carotid to femoral (p<.03), and PWV femoral to distal (p<.02). Significant condition*time interactions were found in SBP (p<.01), DBP (p<.01), MAP (p<.01), SV (p<.01), CO (p<.01), SVR (p<.01), TVI (p<.01), HR (p<.01), and SAE (p<.01). Significant condition main effects were found in SBP (p<.02), DBP (p<.03), PR (p<.03), SV (p<.01), CO (p=.01), SVR (p<.01), TVI (p<.01), HR (p<.01), and SAE (p<.03) as well as a condition trend in PWV femoral to distal (p=.06). Significant time main effects were found in SBP (p<.01), MAP (p<.04), PP (p<.01), PR (p<.01), CO (p<.01), SVR (p<.01), TVI (p<.01), HR (p<.01), SpO2 (p<.01), LAE (p<.03), and PWV femoral to distal (p<.01).

CONCLUSION: The 60 min session at a moderate aerobic intensity might have the potential to improve arterial elasticity more than a 20 min BFR session.


Flowering And Seed Production In The Subtropical Seagrass, Halodule Wrightii (Shoal Grass), Joseph L. Kowalski, Hudson R. Deyoe May 2016

Flowering And Seed Production In The Subtropical Seagrass, Halodule Wrightii (Shoal Grass), Joseph L. Kowalski, Hudson R. Deyoe

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

Reproductive structures of the seagrass, Halodule wrightii Ascherson (shoal grass) are cryptic and ephemeral, but were found on several occasions at several sites over more than a decade in the subtropical Laguna Madre (USA). Structures align with descriptions for H. wrightii. Male, but no female flowers were found, but the numerous fruit-bearing shoots imply the occurrence of pistillate flowers. Mean seed bank density was 890 seeds m-2 (1900–5200 m-2). Sexual reproduction in H. wrightii is more common than previously believed and the seed bank reserve may contribute to its ecological role as a colonizer of disturbed sediments.


Genetic Structure Of Faucet Snail, Bithynia Tentaculata Populations In North America, Based On Microsatellite Markers, Kathryn E. Perez, Rebecca L. Werren, Christopher A. Lynum, Levi A. Hartman, Gabor Majoros, Rebecca A. Cole May 2016

Genetic Structure Of Faucet Snail, Bithynia Tentaculata Populations In North America, Based On Microsatellite Markers, Kathryn E. Perez, Rebecca L. Werren, Christopher A. Lynum, Levi A. Hartman, Gabor Majoros, Rebecca A. Cole

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

Bithynia tentaculata is believed to have been extirpated from North America during the last glacial maximum. It was reintroduced into North America via the Great Lakes basin in the 1800’s and has recently been expanding its geographic range. This snail serves as intermediate host for three trematodes that cause extensive recurring morbidity and mortality events in migratory water birds along the Mississippi River. Using twelve microsatellite loci for ~200 individual snails from 11populations in North America and Europe, we examined one of the three major geographic regions from which founding populations into the Great Lakes typically originate. Our data supports …


Translating Ecology, Physiology, Biochemistry And Population Genetics Research To Meet The Challenge Of Tick And Tick-Borne Diseases In North America, Maria Dolores Esteve-Gassent, Ivan Castro-Arellano, Teresa Patricia Feria-Arroyo, Ramiro Patino, Andrew Y. Li, Raul F. Medina, Adalberto A. Pérez De León, Roger Iván Rodríguez-Vivas May 2016

Translating Ecology, Physiology, Biochemistry And Population Genetics Research To Meet The Challenge Of Tick And Tick-Borne Diseases In North America, Maria Dolores Esteve-Gassent, Ivan Castro-Arellano, Teresa Patricia Feria-Arroyo, Ramiro Patino, Andrew Y. Li, Raul F. Medina, Adalberto A. Pérez De León, Roger Iván Rodríguez-Vivas

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

Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The adoption of an evolutionary ecology framework aimed to diminish the impact of tick-borne diseases needs to be part of strategies to protect human and animal populations. We present a review of current knowledge on the adaptation of ticks to their environment, and the impact that global change could have on their geographic distribution in North America. Environmental pressures will affect tick population genetics by selecting genotypes able to withstand new and changing environments and by altering the connectivity and isolation of several …


A Review On The Respiratory System Toxicity Of Carbon Nanoparticles, Maricica Pacurari, Kristine L. Lowe, Paul B. Tchounwou, Ramzi Kafoury Apr 2016

A Review On The Respiratory System Toxicity Of Carbon Nanoparticles, Maricica Pacurari, Kristine L. Lowe, Paul B. Tchounwou, Ramzi Kafoury

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

The respiratory system represents the main gateway for nanoparticles’ entry into the human body. Although there is a myriad of engineered nanoparticles, carbon nanoparticles/nanotubes (CNPs/CNTs) have received much attention mainly due to their light weight, very high surface area, durability, and their diverse applications. Since their discovery and manufacture over two decades ago, much has been learned about nanoparticles’ interactions with diverse biological system models. In particular, the respiratory system has been of great interest because various natural and man-made fibrous particles are known to be responsible for chronic and debilitating lung diseases. In this review, we present up-to-date the …


Variation In Stem Mortality Rates Determines Patterns Of Above-Ground Biomass In Amazonian Forests: Implications For Dynamic Global Vegetation Models, Michelle O. Johnson, David R. Galbraith, Manuel Gloor, Hannes De Deurwaerder, Matthieu Guimberteau, Anja Rammig, Kirsten Thonicke, Hans Verbeeck, Celso Von Randow, Bradley O. Christoffersen Apr 2016

Variation In Stem Mortality Rates Determines Patterns Of Above-Ground Biomass In Amazonian Forests: Implications For Dynamic Global Vegetation Models, Michelle O. Johnson, David R. Galbraith, Manuel Gloor, Hannes De Deurwaerder, Matthieu Guimberteau, Anja Rammig, Kirsten Thonicke, Hans Verbeeck, Celso Von Randow, Bradley O. Christoffersen

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

Understanding the processes that determine above-ground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody productivity [woody net primary productivity (NPP)] and the rate at which carbon is lost through tree mortality. Here, we test whether two direct metrics of tree mortality (the absolute rate of woody biomass loss and the rate of stem mortality) and/or woody NPP, control variation in AGB among 167 plots in intact forest across Amazonia. We then compare these relationships …


Chloroplast Capture In Juniperus Sabina Var. Balkanensis R. P. Adams And A. N. Tashev, From The Balkan Peninsula: A New Variety With A History Of Hybridization With J. Thurifera, Robert P. Adams, Andrea E. Schwarzbach, Alexander N. Tashev Apr 2016

Chloroplast Capture In Juniperus Sabina Var. Balkanensis R. P. Adams And A. N. Tashev, From The Balkan Peninsula: A New Variety With A History Of Hybridization With J. Thurifera, Robert P. Adams, Andrea E. Schwarzbach, Alexander N. Tashev

Health & Biomedical Sciences Faculty Publications

example of chloroplast capture has been identified in Juniperus sabina from Bulgaria and Greece in the Balkan peninsula. Nuclear DNA and overall morphology clearly indicate a close relationship to Juniperus sabina, whereas the cpDNA from these populations is very uniform and is nearly identical to that of J. thurifera, an unrelated species currently growing in France, Spain and Morocco. The new taxon is recognized as Juniperus sabina var. balkanensis R. P. Adams and A. Tashev. At present, this new variety is known only from locations in Bulgaria and Greece.


Evidence Of Relictual Introgression Or Incomplete Lineage Sorting In Nrdna Of Juniperus Excelsa And J. Polycarpos In Asia Minor, Robert P. Adams, Metin Armagan, Adam Boratynski, Bouchra Douaihy, Magda Dou Dagher-Kharrat, Vahid Farzaliyev, Salih Gucel, Tuğrul Mataraci, Andrea E. Schwarzbach Apr 2016

Evidence Of Relictual Introgression Or Incomplete Lineage Sorting In Nrdna Of Juniperus Excelsa And J. Polycarpos In Asia Minor, Robert P. Adams, Metin Armagan, Adam Boratynski, Bouchra Douaihy, Magda Dou Dagher-Kharrat, Vahid Farzaliyev, Salih Gucel, Tuğrul Mataraci, Andrea E. Schwarzbach

Health & Biomedical Sciences Faculty Publications

DNA analysis of Juniperus excelsa from throughout its range revealed that J. polycarpos, instead of J. excelsa occupies central and eastern Turkey. Based on nrDNA (ITS) data, it appears that relictual hybridization has occurred in southeastern Turkey between J. polycarpos and J. turcomanica. Surprisingly, evidence of incomplete lineage sorting or relictual hybridization between J. polycarpos and J. seravschanica was found in central Turkey and northwest Iran.


Chloroplast Capture By A New Variety, Juniperus Sabina Var. Balkanensis R. P. Adams And A. N. Tashev, From The Balkan Peninsula: A Putative Stabilized Relictual Hybrid Between J. Sabina And Ancestral J. Thurifera, Robert P. Adams, Andrea E. Schwarzbach, Alexander N. Tashev Apr 2016

Chloroplast Capture By A New Variety, Juniperus Sabina Var. Balkanensis R. P. Adams And A. N. Tashev, From The Balkan Peninsula: A Putative Stabilized Relictual Hybrid Between J. Sabina And Ancestral J. Thurifera, Robert P. Adams, Andrea E. Schwarzbach, Alexander N. Tashev

Health & Biomedical Sciences Faculty Publications

An example of chloroplast capture has been found in Juniperus sabina from Bulgaria and Greece in the Balkan peninsula. The cpDNA from these populations is very uniform and is nearly identical to that of J. thurifera (currently growing in France, Spain and Morocco). The new taxon is recognized as Juniperus sabina var. balkanensis R. P. Adams and A. Tashev. At present, the variety, with the thurifera cpDNA, is known only from Bulgaria and Greece.


Plasticity In Leaf-Level Water Relations Of Tropical Rainforest Trees In Response To Experimental Drought, Oliver J. Binks, Patrick Meir, Lucy Rowland, Antonio Carlos Lola Da Costa, Steel Silva Vasconcelos, Alex Antonio Ribeiro De Oliveira, Leandro Ferreira, Bradley O. Christoffersen, Andrea Nardini, Maurizio Mencuccini Mar 2016

Plasticity In Leaf-Level Water Relations Of Tropical Rainforest Trees In Response To Experimental Drought, Oliver J. Binks, Patrick Meir, Lucy Rowland, Antonio Carlos Lola Da Costa, Steel Silva Vasconcelos, Alex Antonio Ribeiro De Oliveira, Leandro Ferreira, Bradley O. Christoffersen, Andrea Nardini, Maurizio Mencuccini

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

Summary

  • The tropics are predicted to become warmer and drier, and understanding the sensitivity of tree species to drought is important for characterizing the risk to forests of climate change. This study makes use of a long-term drought experiment in the Amazon rainforest to evaluate the role of leaf-level water relations, leaf anatomy and their plasticity in response to drought in six tree genera.
  • The variables (osmotic potential at full turgor, turgor loss point, capacitance, elastic modulus, relative water content and saturated water content) were compared between seasons and between plots (control and through-fall exclusion) enabling a comparison between short- …


Beyond The Adaptationist Legacy: Updating Our Teaching To Include A Diversity Of Evolutionary Mechanisms, Rebecca M. Price, Kathryn E. Perez Feb 2016

Beyond The Adaptationist Legacy: Updating Our Teaching To Include A Diversity Of Evolutionary Mechanisms, Rebecca M. Price, Kathryn E. Perez

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

A paradigm shift away from viewing evolution primarily in terms of adaptation - the "adaptationist programme" of Gould and Lewontin - began in evolutionary research more than 35 years ago, but that shift has yet to occur within evolutionary education research or within teaching standards. We review three instruments that can help education researchers and educators undertake this paradigm shift. The instruments assess how biology undergraduates understand three evolutionary processes other than natural selection: genetic drift, dominance relationships among allelic pairs, and evolutionary developmental biology (evo-devo). Testing with these instruments reveals that students often explain a diversity of evolutionary mechanisms …


Comparative Analysis Of Xenorhabdus Koppenhoeferi Gene Expression During Symbiotic Persistence In The Host Nematode, Ruisheng An, Parwinder Grewal Jan 2016

Comparative Analysis Of Xenorhabdus Koppenhoeferi Gene Expression During Symbiotic Persistence In The Host Nematode, Ruisheng An, Parwinder Grewal

School of Earth, Environmental, & Marine Sciences Faculty Publications

Species of Xenorhabdus and Photorhabdus bacteria form mutualistic associations with Steinernema and Heterorhabditis nematodes, respectively and serve as model systems for studying microbe-animal symbioses. Here, we profiled gene expression of Xenorhabdus koppenhoeferi during their symbiotic persistence in the newly formed infective juveniles of the host nematode Steinernema scarabaei through the selective capture of transcribed sequences (SCOTS). The obtained gene expression profile was then compared with other nematode-bacteria partnerships represented by Steinernema carpocapsae-Xenorhabdus nematophila and Heterorhabditis bacteriophora-Photorhabdus temperata. A total of 29 distinct genes were identified to be up-regulated and 53 were down-regulated in X. koppenhoeferi while in S. scarabaei infective …