Environmental Sciences Commons^™

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 …

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 …

Health Impacts Of Traffic Related Air Pollution, Amit U. Raysoni, Wen-Wahi Li

School of Earth, Environmental, & Marine Sciences Faculty Publications

Ambient air pollution can be a serious cause of concern for any community. Anthropogenic ambient air pollutants can emanate from industries, traffic, geological sources and domestic heating and cooking. However, studies have shown that traffic related air pollution can have far more detrimental health effects than non-combustion sources. These adverse health effects are most profound in sensitive populations like the elderly and young children. The World Health Organization (WHO) attributes more than 300 million deaths every year to ambient air pollution. The WHO’s Air Quality Guidelines (AQG) and the United States Environment Protection Agency’s (USEPA) National Ambient Air Quality Standards …

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 …

Optimization And Validation Of An Enzymatic Method To Quantify Glucose In Potato Tubers, Engil Isadora Pujol Pereira, Tatiana Emanuelli, Dilson Antonio Bisognin, Sergio T. De Freitas

School of Earth, Environmental, & Marine Sciences Faculty Publications

The processing industry requires potato tubers with low levels of reduced sugars, glucose and fructose, which is responsible for the whiteness of the chip color. The objective of this research was to optimize and validate a simple, inexpensive, and precise enzymatic method to quantify glucose in potato tubers. This method will be useful in breeding programs to select clones for processing purposes with low levels of glucose. The validation procedure followed the recommendations described in INMETRO document DOQ-CGCRE-008 in 2003. The method was linear between 1.25 to 40µg of glucose in the sample. The quantification limit was 0.319mg g-1 of …

Rapid Evolution In Introduced Species, ‘Invasive Traits’ And Recipient Communities: Challenges For Predicting Invasive Potential, Kenneth D. Whitney, Christopher A. Gabler

School of Earth, Environmental, & Marine Sciences Faculty Publications

The damaging effects of invasive organisms have triggered the development of Invasive Species Predictive Schemes (ISPS). These schemes evaluate biological and historical characteristics of species and prioritize those that should be the focus of exclusion, quarantine, and/or control. However, it is not clear how commonly these schemes take microevolutionary considerations into account. We review the recent literature and find that rapid evolutionary changes are common during invasions. These evolutionary changes include rapid adaptation of invaders to new environments, effects of hybridization, and evolution in recipient communities. Strikingly, we document 38 species in which the specific traits commonly associated with invasive …

Rapid Evolution In Introduced Species, ‘Invasive Traits’ And Recipient Communities: Challenges For Predicting Invasive Potential, Kenneth D. Whitney, Christopher A. Gabler

School of Earth, Environmental, & Marine Sciences Faculty Publications

The damaging effects of invasive organisms have triggered the development of Invasive Species Predictive Schemes (ISPS). These schemes evaluate biological and historical characteristics of species and prioritize those that should be the focus of exclusion, quarantine, and/or control. However, it is not clear how commonly these schemes take microevolutionary considerations into account. We review the recent literature and find that rapid evolutionary changes are common during invasions. These evolutionary changes include rapid adaptation of invaders to new environments, effects of hybridization, and evolution in recipient communities. Strikingly, we document 38 species in which the specific traits commonly associated with invasive …

An Analysis Of Demographic Disparities Associated With The Proposed U.S.-Mexico Border Fence In Cameron County, Texas, J. Gaines Wilson, Jude A. Benavides, E. Anthony Reisinger, Joseph Lemen, Zachary Hurwitz, Jessica Spangler, Karen Engle

School of Earth, Environmental, & Marine Sciences Faculty Publications

Introduction: The United States Department of Homeland Security (DHS) plans to install a fence along the U.S.-Mexico border by late December 2008. While much attention has been drawn to the environmental, social and political issues surrounding the fence, analysis of demographic data on the populations that will be directly affected has been limited. This paper utilizes geographic information systems (GIS) and U.S. Census Bureau data with the objective of understanding the underlying demographics in areas along the proposed Rio Grande Valley section of the border fence located in Cameron County, Texas.

Data and Methods: Demographic measures of income, education, …

Physiological Aging Of Potato Tubers Produced During Fall And Spring Growing Seasons And Stored Under Different Temperatures, Dilson A. Bisognin, Sergio T. De Freitas, Auri Brackmann, Jeronimo Luiz Andriolo, Engil Isadora Pujol Pereira, Douglas Renator Muller, Mauricio Guerra Bandinelli

School of Earth, Environmental, & Marine Sciences Faculty Publications

Adequate tuber storage is necessary to maintain a good availability of potato tubers in the market and to get seeds with adequate physiological age at planting. The objective of this work was to determine the effect of different storage temperatures on tuber physiological aging of three potato clones produced during fall and spring growing seasons. The experiment was carried out as factorial of three clones (Asterix, SMIJ461-1 and SMINIA793101-3) by four storage temperatures (4, 8, 12 and 25 ºC) and two growing seasons (fall and spring) in a random design with four replications. At 30-day intervals, tubers were evaluated from …

Trampling, Peeling And Nibbling Mussels: An Experimental Assessment Of Mechanical And Predatory Damage To Shells Of Mytilus Trossulus (Mollusca: Mytilidae), Carlos E. Cintra-Buenrostro

School of Earth, Environmental, & Marine Sciences Faculty Publications

Shell damage, if properly recognized, can provide information about biotic interactions between molluscs and their predators. However, it can be difficult to distinguish predatory damage from mechanical breakage, thus making interpretation of damaged modern and fossil shells problematic. To establish a clear-cut distinction between antemortem predatory crab damage and ante- and postmortem mechanical damage in Mytilus trossulus shells, a combined field and experimental approach was used. Mussels were exposed to predation by crabs, tumbled-live, tumbled-dead, and trampled. After 100 h of tumbling, live-collected mussel shells were abraded and disarticulated but not otherwise damaged. Eight percent of the dead-collected shells were …

On The Use Of Modis Evi To Assess Gross Primary Productivity Of North American Ecosystems, Daniel A. Sims, Abdullah Rahman, Vicente D. Cordova, Bassil Z. El-Masri, Dennis D. Baldocchi, Lawrence B. Flanagan, Allen H. Goldstein, David Y. Hollinger, Laurent Misson, Russell K. Monson, Walter C. Oechel, Hans P. Schmid, Steven C. Wofsy, Liukang Xu

School of Earth, Environmental, & Marine Sciences Faculty Publications

[1] Carbon flux models based on light use efficiency (LUE), such as the MOD17 algorithm, have proved difficult to parameterize because of uncertainties in the LUE term, which is usually estimated from meteorological variables available only at large spatial scales. In search of simpler models based entirely on remote‐sensing data, we examined direct relationships between the enhanced vegetation index (EVI) and gross primary productivity (GPP) measured at nine eddy covariance flux tower sites across North America. When data from the winter period of inactive photosynthesis were excluded, the overall relationship between EVI and tower GPP was better than that between …

Study Of Metals In Leached Soils Of A Municipal Dumpsite In Tampico, Tamaulipas, Mexico: Preliminary Results, P. F. Rodríguez-Espinosa, D. Chazaro Mendoza, J. A. Montes De Oca, G. Sánchez Torres E., Alejandro Fierro-Cabo

School of Earth, Environmental, & Marine Sciences Faculty Publications

The Zapote dumpsite measures 420000 m 2 and is 28 years old; an estimated 2.5 millions tons of waste have accumulated on the site (household waste, clinical waste, commercial waste). The thickness of the waste is 3 to 9 meters. Since operations began, no control regulations have existed on the residues received. The Zapote dumpsite is located within a salt-marsh between a system of channels and river lagoons of brackish water, located in a tropical sedimentary environment in the urban zone of Tampico, Tamaulipas, Mexico. Recently, the Zapote has been closed and work is presently underway in its rehabilitation since …

Detecting Submarine Groundwater Discharge With Synoptic Surveys Of Sediment Resistivity, Radium, And Salinity, John A. Breier, Crystaline F. Breier, Henrietta Edmonds

School of Earth, Environmental, & Marine Sciences Faculty Publications

A synoptic geophysical and geochemical survey was used to investigate the occurrence and spatial distribution of submarine discharges of water to upper Nueces Bay, Texas. The 17 km survey incorporated continuous resistivity profiling; measurements of surface water salinity, temperature, and dissolved oxygen; and point measurements of dissolved Ra isotopes. The survey revealed areas of interleaving, vertical fingers of high and low conductivity extending up through 7 m of bay bottom sediments into the surface water, located within 100 m of surface salinity and dissolved Ra maxima along with peaks in water temperature and lows in dissolved oxygen. These results indicate …

Potential Of Modis Evi And Surface Temperature For Directly Estimating Per-Pixel Ecosystem C Fluxes, Abdullah Rahman, Daniel A. Sims, Vicente D. Cordova, Bassil Z. El-Masri

School of Earth, Environmental, & Marine Sciences Faculty Publications

We tested the potential of estimating per-pixel gross primary production (GPP) directly from the MODIS enhanced vegetation index (EVI) and respiration directly from MODIS surface temperature (MOD11). Carbon flux data were obtained from 10 eddy covariance tower sites representing a wide range of North American vegetations. The correlation between across-site tower GPP and EVI was comparable (r = 0.77) to that between tower GPP and MOD17-GPP (r = 0.73), suggesting that EVI could be used to provide reasonably accurate direct estimates of GPP on a truly per-pixel basis. There was also a strong relationship (r2 = 0.67) between respiration and …

Oceanographic Conditions And Diversity Of Sea Stars (Echinodermata: Asteroidea) In The Gulf Of California, México, Carlos E. Cintra-Buenrostro, Hector Reyes-Bonilla, Maria Dinorah Herrero-Perezrul

School of Earth, Environmental, & Marine Sciences Faculty Publications

Species richness is one of the best indicators of biodiversity. However, there are few investigations on concordance of diversity patterns and environmental settings for marine regions. The objectives of this study were to correlate species richness of shallow water (< 200 m deep) sea stars with key oceanographic factors in the Gulf of California, México, and to predict species richness of Asteroidea using multiple regressions. In these analyses the Gulf was divided into nine sections of one degree in latitude (from 23 - 31° N), at each section we recorded: continental shelf area (at 100 and 200 m depth), temperature mean and range at three depth levels (0, 60 and 120 m), thermocline depth, surface nutrient concentrations (nitrates, phosphates and silicates), surface photosynthetic pigment concentration, and integrated productivity. Sea star species richness at each latitudinal section was estimated from literature data, new collections and museum records. Species were assigned to one of the following feeding guilds: predators of small mobile invertebrates (I), detritivores (D), predators of colonial organisms (C), generalist carnivores (G), and planktivores (P). There are 47 shallow water asteroid species in the Gulf of California (16 I, 15 D, eight C, six G, one P and one not assigned). Total species richness and guild species richness showed strong latitudinal attenuation patterns and were higher in the southernmost Gulf, an area characterized by a narrow shelf, high temperature, and low nutrient concentrations. Species diversity for each guild was correlated to a set of oceanographic parameters: temperature, nitrate concentration, and integrated productivity were linked to richness in must cases. We detected that nutrients and surface pigments always presented negative relationships with species richness, indicating that productive environments limit asteroid diversity in the study area. Finally, the postulated regression models to estimate species richness from oceanographic data were significant and highly precise. We conclude that species richness of Asteroidea in the Gulf of California is related to oceanographic conditions and can be estimated from regional oceanographic information.

Tracking The Sea-Level Signature Of The 8.2 Ka Cooling Event: New Constraints From The Mississippi Delta, Torbjörn E. Törnqvist, Scott J. Bick, Juan L. Gonzalez, Klaas Van Der Borg, Arie F. M. De Jong

School of Earth, Environmental, & Marine Sciences Faculty Publications

The ever increasing need for accurate predictions of global environmental change under greenhouse conditions has sparked immense interest in an abrupt, century‐scale cooling around 8200 years ago, with a focal point in the North Atlantic and with hemispheric teleconnections. Despite considerable progress in the unraveling of this striking feature, including a conceivable driving mechanism (rapid drainage of proglacial Lake Agassiz/Ojibway and a resulting reduced strength of North Atlantic thermohaline circulation), several key questions remain unanswered. One salient aspect concerns the total amount of freshwater released during this catastrophic event, likely echoed by a near‐instantaneous eustatic sea‐level rise. So far, no …

Potential Of Modis Ocean Bands For Estimating Co2 Flux From Terrestrial Vegetation: A Novel Approach, Abdullah Rahman, Vicente D. Cordova, John A. Gamon, Hans Peter Schmid, Daniel A. Sims

School of Earth, Environmental, & Marine Sciences Faculty Publications

A physiologically-driven spectral index using two ocean-color bands of MODIS satellite sensor showed great potential to track seasonally changing photosynthetic light use efficiency (LUE) and stress-induced reduction in net primary productivity (NPP) of terrestrial vegetation. Based on these findings, we developed a simple ‘‘continuous field’’ model solely based on remotely sensed spectral data that could explain 88% of variability in flux-tower based daily NPP. For the first time, such a procedure is successfully tested at landscape level using satellite imagery. These findings highlight the unexplored potential of narrow-band satellite sensors to improve estimates of spatial and temporal distribution in terrestrial …

Supplemental Carbon Dioxide And Light Improved Tomato And Pepper Seedling Growth And Yield, Alejandro Fierro, Nicolas Tremblay, André Gosselin

School of Earth, Environmental, & Marine Sciences Faculty Publications

The experiment was conducted to determine the effects of CO, enrichment (900 μl·liter-1, 8 hours/day) in combination with supplementary lighting of 100 μmol·s-1·m-2 (16- h photoperiod) on tomato (Lycopersicon esculentum Mill.) and sweet pepper (Capsicum annuum L.) seedling growth in the greenhouse and subsequent yield in the field. Enrichment with CO2 and supplementary lighting for » 3 weeks before transplanting increased accumulation of dry matter in shoots by » 50% compared with the control, while root dry weight increased 49% for tomato and 6270 for pepper. Early yields increased by =1570 and 11% for tomato and pepper, respectively.