Western Texas Research Articles

Mitochondrial DNA Phylogeography of Black Bears (Ursus americanus) in Central and Southern North America: Conservation Implications

The American black bear (Ursus americanus) experienced a significant range contraction during the 19th and 20th centuries due to a variety of anthropogenic factors. Although previous molecular studies of black bears provided insight into historic and contemporary forces shaping phylogeographic patterns, none included black bears from the central part of the species distribution. Understanding the historical aspects of the connectivity and genetic differentiation of black bears in this region is important for proper management and conservation programs, but this understanding is confounded by poorly documented translocation efforts and population expansion. To address these issues, we generated mitochondrial DNA sequence data for 409 black bears from 15 populations in North America. Two sampling localities (Manitoba, Canada, and Minnesota) were source populations for translocation into western Arkansas and Louisiana. Major conclusions from our study include: black bears in western Arkansas were affected genetically by the translocation program; eastern Oklahoma has been repopulated by westward expansion of bears from Arkansas with a mixture of translocated bears and remnant individuals; black bears in Louisiana were not affected genetically by the translocation program; black bears in western Texas and northern Mexico dispersed there from the southeastern United States; and bears in White River National Wildlife Refuge (eastern Arkansas) share closer genetic affinities with U. a. luteolus than they do with the widespread U. a. americanus.

Efficacy of Antioxidant Overproduction on Fiber Growth and Maturation in Cotton

ABSTRACTElectron transport in plant cells inevitably results in the creation of reactive oxygen species (ROS) that can hinder metabolic processes and cause cellular damage. In spite of the gains additional antioxidants may impart to the cotton (Gossypium hirsutum L.) photosynthetic apparatus, single time point measurements on live plants have not reflected distinguishable phenotypes for key physiological measures. Transgene efficacy may also be quantified by measuring cumulative agronomic performance (lint yield and quality) under conditions that promote photorespiration and ROS production. To test this hypothesis, cotton lines constitutively expressing the ascorbate peroxidase (APX) or glutathione reductase (GR) protein were examined in field trials (2005, 2006, and 2007) under three different irrigation treatments. Yield, gin turnout, and 23 measures of fiber quality were assessed. Transgene (APX and GR) efficacy and in vitro culture effects were estimated by comparing a line's performance with the null and wild‐type checks based on an analysis of variance using a linear mixed model to estimate general least squares and variance components. Significant effects were observed in 18 traits. Despite no significant changes in fiber maturity, all GR and APX transgenic lines produced significantly finer fibers than the wild‐type. Fiber maturity is a problem in western Texas that affects most fiber quality measures especially the fineness measurement micronaire.

Spring and Winter Records of the Eastern Pipistrelle (Perimyotis Subflavus) in Southeastern New Mexico

Eastern pipistrelles (Perimyotis subflavus) were first documented from South Dakota, western Texas, and New Mexico during recent years, suggesting that the distribution of this species is expanding westward across central parts of North America. In New Mexico, only 2 records of P. subflavus previously were known—one from summer and one from autumn. Here we report on 3 new records of P. subflavus from southeastern New Mexico, including the first 2 records from winter and the first record from spring. One individual in winter was observed hibernating in a cave in Chaves County. Our records and previous ones from autumn and summer suggest that this species is resident throughout the year in New Mexico.

Optimizing geologic CO 2 sequestration by injection in deep saline formations below oil reservoirs

The purpose of this research is to present a best-case paradigm for geologic CO 2 storage: CO 2 injection and sequestration in saline formations below oil reservoirs. This includes the saline-only section below the oil–water contact (OWC) in oil reservoirs, a storage target neglected in many current storage capacity assessments. This also includes saline aquifers (high porosity and permeability formations) immediately below oil-bearing formations. While this is a very specific injection target, we contend that most, if not all, oil-bearing basins in the US contain a great volume of such strata, and represent a rather large CO 2 storage capacity option. We hypothesize that these are the best storage targets in those basins. The purpose of this research is to evaluate this hypothesis. We quantitatively compared CO 2 behavior in oil reservoirs and brine formations by examining the thermophysical properties of CO 2, CO 2–brine, and CO 2–oil in various pressure, temperature, and salinity conditions. In addition, we compared the distribution of gravity number ( N), which characterizes a tendency towards buoyancy-driven CO 2 migration, and mobility ratio ( M), which characterizes the impeded CO 2 migration, in oil reservoirs and brine formations. Our research suggests competing advantages and disadvantages of CO 2 injection in oil reservoirs vs. brine formations: (1) CO 2 solubility in oil is significantly greater than in brine (over 30 times); (2) the tendency of buoyancy-driven CO 2 migration is smaller in oil reservoirs because density contrast between oil and CO 2 is smaller than it between brine and oil (the approximate density contrast between CO 2 and crude oil is ∼100 kg/m 3 and between CO 2 and brine is ∼350 kg/m 3); (3) the increased density of oil and brine due to the CO 2 dissolution is not significant (about 7–15 kg/m 3); (4) the viscosity reduction of oil due to CO 2 dissolution is significant (from 5790 to 98 mPa s). We compared these competing properties and processes by performing numerical simulations. Results suggest that deep saline CO 2 injection immediately below oil formations reduces buoyancy-driven CO 2 migration and, at the same time, minimizes the amount of mobile CO 2 compared to conventional deep saline CO 2 injection (i.e., CO 2 injection into brine formations not below oil-bearing strata). Finally, to investigate practical aspects and field applications of this injection paradigm, we characterized oil-bearing formations and their thickness (capacity) as a component of the Southwest Regional Partnership on Carbon Sequestration (SWP) field deployments. The field-testing program includes specific sites in Utah, New Mexico, Wyoming, and western Texas of the United States.

Mexican Long-tongued Bat (Choeronycteris mexicana) in El Paso, Texas

The Mexican long-tongued bat Choeronycteris mexicana is rare in Texas, as well as elsewhere in the United States and in Mexico. A C. mexicana was captured in December 2007 at a residence in El Paso, El Paso County, Texas. This is the first record of this species in western Texas.

The Pediatric Infectous Disease Journal® Newsletter

The Pediatric Infectous Disease Journal® Newsletter

Combining airborne electromagnetic induction and hydrochemistry to quantify salinity contributions to a large basin stream, Colorado River, Texas, USA

ABSTRACTWe combined multifrequency airborne electromagnetic induction (EM) measurements of apparent ground conductivity with chemical analyses of surface water to delineate natural and oilfield salinity sources that degrade surface water quality by elevating total dissolved solids, chloride and sulphate concentrations along several hundred kilometres of the Colorado River (western Texas, USA). To reduce the cost of airborne geophysical surveying over such large areas, we used a helicopter to tow an EM instrument at low altitude along the stream‐axis and measure the apparent electrical conductivity of the ground at multiple frequencies, examined results in the field to identify salinized stream segments and optimal water sampling locations and then flew more detailed surveys over these limited areas rather than over the entire basin as is typical in salinization studies. Minimally processed stream‐axis EM data (including apparent conductivities measured at single frequencies and multifrequency ‘spectrograms’ along the stream‐axis) helped identify salinized streambed segments, discriminate between surface and subsurface sources of salinity and determine water sampling locations upstream and downstream from each segment. We integrated EM, streamflow and hydrochemical data to calculate salinity loads, identify specific natural and oilfield salinity sources and guide and implement remediation efforts.Stream‐axis flight lines offer the advantage of rapidly acquiring high‐resolution subsurface conductivity data along long stream segments where traditional gridded flight‐line surveys and waterborne measurements are impractical or prohibitively expensive. They also overcome difficulties associated with topographic effects when surveying deeply incised streams. Such surveys provide valuable information on location, extent and type of salinization and can guide water sampling and more intensive ground or airborne measurements.

POSSIBLE MANSO OCCUPATION AT SITE LA129533 NEAR EL PASO, TEXAS

The difficulties in recognizing Late El Paso phase or protohistoric occupations in southern New Mexico and western Texas are well known. After the decline of the Puebloan system in the late fourteenth and early fifteenth centuries, the region was not abandoned, as evidenced by populations of mobile hunter-gatherers encountered by Spanish explorers and missionaries in the 1500s and 1600s. Attributing sites to this period is difficult; features are hard to recognize, and ceramic assemblages are difficult to isolate particularly at sites with multicomponent ceramic assemblages. At LA 129533, nine brown ware sherds with attributes fitting mobile hunter-gatherer groups were associated with a feature yielding a calibrated radiocarbon date of A.D. 1310–1360 andA.D. 1390–1440. They show little evidence of formal tool use in production of the vessel, typical of pottery produced using an expedient technology by mobile hunter-gatherers.

CHANGE AND STABILITY IN PERMIAN BRACHIOPOD COMMUNITIES FROM WESTERN TEXAS

The silicified brachiopod faunas collected by G. Arthur Cooper and Richard E. Grant over decades of field work in the Permian Basin of western Texas provide a remarkable resource for studying change in the structure of fossilized ecological communities. Ordination analyses using 511 faunal lists that include 967 species (190 genera) from the Kungurian through the Capitanian Stages of the Guadalupe and Glass Mountains (∼15 myr) reveal four distinct, major stratigraphic clusters, each divisible into two to three subclusters. For the most part, these clusters coincide with third-order depositional sequences bounded by unconformities. Except for the youngest (Capitanian Stage), all the stratigraphic clusters show internal ordination patterns consistent with biogeographic and environmental (i.e., biotic gradients) control on the distribution of taxa. Despite this evidence for environmental sorting of taxa, Mantel tests indicate that patterns of generic co-occurrence break down from cluster to cluster despite sharing many of the same species and genera. This pattern cannot easily be explained by preservational or stratigraphic biases, suggesting that the processes that govern ecological communities may not lead to unique, strictly determined associations despite the presence of broadly similar species under similar environmental conditions. In contrast to the rest of the study interval, Capitanian clusters are less well structured (i.e., they do not show strong biotic gradients) than assemblages from any of the other clusters and do not show significant recurrence of generic associations. This may reflect evolution of carbonate margins in the basin from ramps to shelves with steep slopes over the duration of the study interval, a shift that may have changed the spatial distribution of (and covariation among) the environmental parameters that controlled brachiopod distributions.

Impacts of Multiple Stresses on Water Demand and Supply Across the Southeastern United States1

Abstract: Assessment of long‐term impacts of projected changes in climate, population, and land use and land cover on regional water resource is critical to the sustainable development of the southeastern United States. The objective of this study was to fully budget annual water availability for water supply (precipitation − evapotranspiration + groundwater supply + return flow) and demand from commercial, domestic, industrial, irrigation, livestock, mining, and thermoelectric uses. The Water Supply Stress Index and Water Supply Stress Index Ratio were developed to evaluate water stress conditions over time and across the 666 eight‐digit Hydrologic Unit Code basins in the 13 southeastern states. Predictions from two Global Circulation Models (CGC1 and HadCM2Sul), one land use change model, and one human population model, were integrated to project future water supply stress in 2020. We found that population increase greatly stressed water supply in metropolitan areas located in the Piedmont region and Florida. Predicted land use and land cover changes will have little effect on water quantity and water supply‐water demand relationship. In contrast, climate changes had the most pronounced effects on regional water supply and demand, especially in western Texas where water stress was historically highest in the study region. The simulation system developed by this study is useful for water resource planners to address water shortage problems such as those experienced during 2007 in the study region. Future studies should focus on refining the water supply term to include flow exchanges between watersheds and constraints of water quality and environmental flows to water availability for human use.

Paleogene paleosols and changes in pedogenesis during the initial Eocene thermal maximum: Big Bend National Park, Texas, USA

Research Article| November 01, 2008 Paleogene paleosols and changes in pedogenesis during the initial Eocene thermal maximum: Big Bend National Park, Texas, USA Paul D. White; Paul D. White † 1Physics Department, Community College of Rhode Island, 400 East Avenue, Warwick, Rhode Island, 02886, USA †E-mail: pdwhite1@ccri.edu Search for other works by this author on: GSW Google Scholar Judith Schiebout Judith Schiebout 2Museum of Natural Science and the Department of Geology and Geophysics, Louisiana State University, Baton Rouge, Louisiana 70803, USA Search for other works by this author on: GSW Google Scholar GSA Bulletin (2008) 120 (11-12): 1347–1361. https://doi.org/10.1130/B25987.1 Article history received: 10 Feb 2006 rev-recd: 14 Dec 2006 accepted: 25 Jul 2007 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Paul D. White, Judith Schiebout; Paleogene paleosols and changes in pedogenesis during the initial Eocene thermal maximum: Big Bend National Park, Texas, USA. GSA Bulletin 2008;; 120 (11-12): 1347–1361. doi: https://doi.org/10.1130/B25987.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract This paper tests the hypothesis that continental chemical weathering increased during the initial Eocene thermal maximum (IETM) by comparing paleosols that formed before and during the event in western Texas. The chemical index of alteration (CIA) was used to investigate the weathering of silicate minerals. Paleosols generated before the IETM have CIA values ranging from 62 to 72, and CIA values during the IETM range from 67 to 82. The CIA values for pre–initial Eocene thermal maximum paleosols indicate moderate weathering conditions, and CIA values during the event indicate moderate to extreme weathering conditions. The clay mineralogy of the paleosols is dominated by smectite, and it is only within paleosols that formed during the IETM that there is a change. There is a notable increase in the amount of kaolinite in one paleosol horizon that is associated with the carbon excursion. In addition, there is an increase in the translocation of clays and iron, and an increase in the leaching of calcite and plagioclase in initial Eocene thermal maximum paleosols. The differences between soils that formed before and during the initial Eocene thermal maximum indicate that chemical weathering did increase during this ancient global warming event. The mechanism responsible for increased weathering is interpreted to be an increase in hydrolysis reactions caused by an increase in humidity and an increase of carbonic acid in the soil due to elevated CO2 levels during the initial Eocene thermal maximum. Documentation of an increase in chemical weathering during the initial Eocene thermal maximum is significant because it may have served as a negative feedback to reduce atmospheric CO2. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

First Host-Plant and New Distribution Records of the Plant Bug Larinocerus personatus (Knight), with Notes on the Host and Distribution of the Related Hambletoniola antennata Carvalho (Hemiptera: Miridae: Phylinae)

Three closely related species of phyline plant bugs are unique in the diverse family Miridae because of their remarkable antennae; the third (or second and third) flagellomere is enlarged and bears erect, dark, scalelike setae. Host plants for two of the species—Hambletoniola antennata Carvalho and Larinocerus balius Froeschner—have been known, but no host information has been available for L. personatus (Knight). Escobilla butterflybush, Buddleja scordioides Kunth (Scrophulariaceae), is newly recorded as the host of L. personatus in western (Trans-Pecos) Texas, and new Texas records are given for this seldom-collected mirid. New distribution records also are given for H. antennata in western Texas, in addition to its occurrence on ceniza, Leucophyllum frutescens (Berl.) I.M. Johnston (Scrophulariaceae). Scanning electron micrographs of the antennal setae of L. personatus are provided; included for both mirid species are color photographs of their host plants and an adult on host foliage.

Larger than reported

B ritton and Rose thought the Horse Crippler was special, so much so that they published a new name1 for what Hoppfer first described as Echinocactus texensis in 1842. Their monotypic genus, Homalacephala (meaning flat head), never caught on, but the species remains well known throughout its range under a variety of colorful common names: Candy Cactus, Devil’s Head, Viznaga, Manca Caballo. Hunkered down in the grasslands, often flat to the ground, long 3–6.5 cm (1–2′′) stout spines held in defense, these plants have been known to puncture Jeep tires and cripple horses and cattle. In western Texas it is said that ranchers extirpated them from private lands by dragging chains behind their tractors, ripping the cacti out of the ground by the spines.

Characteristics of oxygen-18 and deuterium composition in waters from the Pecos River in American Southwest

The Pecos River, situated in eastern New Mexico and western Texas, receives snowmelt from winter storms in the headwater region of the southern Rocky Mountains and runoff from warm-season monsoonal rainfall in the lower valley. The isotopic composition of the two water sources differs from each other due to their different geographical origins in the Pacific North and the Gulf of Mexico. To better assess the physical features of the Pecos River, oxygen and hydrogen isotopic compositions (δ 18O and δD), major ion concentrations, and other physical variables (e.g., water temperature and electrical conductivity) were measured on water samples collected from the main stem and its selected tributaries during a growing season (March, May, and July) in 2005. The results of this work indicate that stream water from the Pecos River contains a relatively large magnitude of variations in δ 18O and δD, with δ 18O ranging from − 8.9‰ to 3.6‰ and δD from − 64.5‰ to 1.6‰. The average value of δ 18O is around − 3‰, which is significantly larger than that of the snowmelt but almost identical to that of the Mexican monsoonal rainfall. On the other hand, the average value of δD is around − 30‰, which is significantly larger than that of the snowmelt but lower than that of the Mexican monsoonal rainfall. Application of a dual isotope index, deuterium excess (d-excess), allows us to assess the relative contribution of various hydrologic components and processes that shape the stream hydrology of the Pecos River. The river water from the upper valley is characterized by relatively low values of δ 18O and δD and relatively high values of d-excess ( d = 10‰), documenting the isotopic fingerprint of the snowmelt. The middle basin is topographically gentle and its water quality has been severely affected by anthropogenic disturbances (e.g., water impoundments and diversions). As a result, chemical and isotopic composition of the water from the middle basin is highly variable, depending on its time, location, and degree of disturbances. Both δ 18O and δD increase significantly from upstream to downstream and from cold to warm seasons because of evaporation-induced isotopic enrichments. The average δ 18O value of the heavy-isotope-enriched waters from the middle basin is identical to that of the waters from the lower valley. In contrast, d-excess of the waters from the middle basin usually is negative, and substantially lower than that of the waters from the lower valley. Using a simple d-excess based hydrologic model, we estimated that there was up to 85% of stream flow which was derived from local freshwater sources (mainly from the Mexican monsoonal rainfall) in the lower valley and that there was up to 33% of stream water which was lost through evaporation occurring in stream channels and fields of the middle basin. Additionally, the correlation of d-excess and electrical conductivity further highlights the role of evaporative enrichments in regulating stream chemistry and isotope hydrology. This study demonstrates the usefulness of combined isotopic and geochemical data, especially the applicability of d-excess, for watershed baseline assessments.

Victorio: Apache Warrior and Chief (review)

Reviewed by: Victorio: Apache Warrior and Chief Robert Wooster Victorio: Apache Warrior and Chief. By Kathleen P. Chamberlain. Norman: University of Oklahoma Press, 2007. ISBN 978-0-8061-3843-5. Maps. Photographs. Illustrations. Bibliographic essay. Index. Pp. xxi, 242. $24.95. On October 15, 1880, Mexican soldiers and militiamen commanded by Colonel Joaquin Terrazas attacked a camp of Chihenne (Warm Springs) and Mescalero Apaches at the remote Tres Castillos range, roughly ninety miles north of Chihuahua City. At the cost of three casualties, the Mexicans killed sixty-two warriors and sixteen women and children, and captured sixty-eight persons. Among those slain was the dynamic leader Victorio, guiding force behind his people’s lengthy and ultimately unsuccessful quest to be allowed to live in their traditional homelands in the Warm Springs country of southwestern New Mexico. In the present work, Kathleen P. Chamberlain provides an empathetic and often revealing examination of the man who offered such hope to his followers, and who sowed so much fear among the non-Indian peoples of Chihuahua, Arizona, New Mexico, and western Texas. Victorio: Apache Warrior and Chief admirably meets the goals of the Oklahoma Western Biographies series, of which it is the twenty-second volume. Chamberlain’s informal, often breezy prose style is well-suited to the intended general readership, and the emphasis on Victorio’s persistent quest to secure for the Chihennes a suitable living space in the face of the United States government’s unsympathetic bureaucracy (in this case the Indian Office) and cruelly one-sided Indian policy provides a useful thematic structure. Nonspecialists in American Indian history will find Chamberlain’s having framed her narrative through the context of Apache culture and world-view especially enlightening. In hypothesizing about the incredulous attempts by Victorio and Nana (his brother-in-law) to understand the government’s disastrous effort to force their people to live at ghastly San Carlos, for example, Chamberlain posits: “After all, the whites in Washington were blind, but were they stupid, too?” (p. 155). Alas, they perhaps were. In accord with series guidelines, Victorio: Apache Warrior and Chief has no notes, but it does boast a valuable bibliographic essay. Readers of all backgrounds should glean many insights from the work, but military historians will find Chamberlain’s decision not to attempt a more systematic analysis of issues relating to war and combat somewhat disappointing. After all, it was her subject’s ability to out-think, out-fight, and out-ride the enemies of his people on both sides of the U. S.-Mexican border that caught the attention of contemporary observers, and that distinguished him from his less talented peers. As the author acknowledges, those seeking such an investigation are still probably best served by Dan Thrapp’s earlier biography, Victorio and the Mimbres Apaches (1974). Robert Wooster Texas A&M University-Corpus Christi Corpus Christi, Texas Copyright © 2008 The Society for Military History

Coccidioidomycosis in a 38‑year‑old man: a case report

The present article describes a case of acute pulmonary coccidioidomycosis in a 38-year-old man, a research worker. The disease started during the patient stay in Arizona, USA, and clinical symptoms persisted after his return to Poland. Acute coccidioidomycosis is one the clinical manifestations of Coccidioides immitis strain endemic infections occurring in the south-western regions of USA including California (mainly San Joaquin Valley), Western Texas, New Mexico and the desert areas of Arizona, and Central and South America. The native environment of Coccidioides immitis is soil penetrated by rodents. People, domestic and wild animals suffer from coccidioidomycosis. The infection rate in endemic areas is about 2-4% a year in the healthy population. Coccidioidomycosis can be observed in non-endemic areas due to population mobility and in immunocompromised patients. The Coccidioides immitis infection is caused by inhaled airborne fungal spores and it may occur as primary pulmonary (acute or chronic) asymptomatic form, meningitis, or disseminated disease. The clinical symptoms of coccidioidomycotis like acute pulmonary manifestations may resemble typical, resistant to empiric antibiotic treatment of bacterial pneumonia. In healthy subjects, pulmonary coccidioidomycosis may occur as asymptomatic infection, which resolves spontaneously without medication. Sometimes, slight shadows like local fibrosis and cavities may be visible on the chest X-ray. The Coccidioides immitis infection in people with immunological deficiency syndromes, e.g. HIV/AIDS, manifests itself as disseminated disease and may lead to severe complications including death.

The scale of genetic differentiation in the Dunes Sagebrush-Lizard (Sceloporus arenicolus), an endemic habitat specialist

The Dunes Sagebrush-Lizard (Sceloporus arenicolus) is a North American species endemic to sand-shinnery oak habitats of the Mescalero and Monahans sand dunes in eastern New Mexico and western Texas. This lizard is listed as Endangered in New Mexico and exhibits habitat specificity at several geographic scales. Dunes Sagebrush-Lizards are only found in topographically complex shinnery oak (Quercus havardii) dominated landscapes within their small geographic distribution and are not found in surrounding human-altered landscapes. Within suitable sand-shinnery oak habitat, individuals predominantly occupy non-vegetated sand dune blowouts and utilize blowouts with particular physical characteristics due to thermoregulatory, reproduction, and foraging requirements. Here, we examined historical and contemporary patterns of genetic differentiation with respect to the current distribution of suitable habitat at multiple spatial scales using mitochondrial DNA sequences and microsatellite data from individuals throughout the entire range. We found three genetic clusters of individuals generally concordant with geographic regions and low sequence divergence at mitochondrial loci suggesting a recent origin of these populations. We also found high levels of genetic structure at microsatellite loci among populations within each of these groups indicating restricted gene flow at intermediate scales. Despite high habitat specificity, we did not detect genetic structure among sand blowouts at finer spatial scales. Within each population, matrices comprised of both sand blowouts and vegetated shinnery oak patches are necessary for genetic connectivity, but the fine scale spatial arrangement of blowouts may not be as critical. We discuss our results with respect to the scale of landscape heterogeneity and habitat connectivity and consider the conservation implications for this threatened taxon.

Modelling potential dispersal corridors for cougars in midwestern North America using least-cost path methods

Since 1990, cougar ( Puma concolor) presence in midwestern North America has been increasing, with >130 confirmed cougar occurrences (i.e., tracks, photos, carcasses) being verified by professional wildlife biologists during this time. Because many of these confirmed cougar occurrences (>30%) have been carcasses of juvenile males, it is likely that cougars are dispersing into the Midwest from established western populations. Although several wildlife biologists have acknowledged the possibility of cougar presence in the region, no research has been conducted regarding potential corridors that may facilitate dispersal. Therefore, our goal was to determine potential dispersal corridors for cougars in a 9-state portion of the Midwest using a habitat suitability model and least-cost path analysis. We modelled 2-km wide dispersal corridors from established western cougar populations to (1) large areas (≥2500 km 2) of highly suitable cougar habitat, and (2) locations of confirmed cougar occurrences ( n = 29) in North Dakota, Nebraska, and Missouri. The most likely dispersal corridor to large areas of highly suitable cougar habitat originated in western Texas and branched into the Ouachita and Ozark National Forests of Oklahoma, Arkansas, and Missouri. Within this corridor, road density was low (79 m/km 2) and forests comprised 45% of land cover; these results are consistent with empirical studies that indicate dispersing cougars travel in habitat that provides cover while generally avoiding human influence. Corridor lengths from potential source populations to confirmed cougar occurrences ranged from 3 km to 1100 km, stream density (i.e., an index of riparian zones) ranged from 79 m/km 2 to 249 m/km 2, and grassland cover comprised >40% of corridors from occupied cougar habitat to confirmed occurrences. High grassland cover and riparian zones within these corridors may allow for movement between forest patches while dispersing through the highly agricultural Midwest. Our analysis provides the first description of potential dispersal corridors for cougars from established western populations into the Midwest. Primary benefits from this research include providing an understanding of landscape permeability for large carnivores in a largely unsuitable matrix, and presenting conservation agencies with useful information should cougars continue to disperse into the region.

Hexactinellid and associated sponges from the upper Reef Trail Member of the Bell Canyon Formation, southern Guadalupe Mountains National Park, Texas

A small faunule of silicified hexactinellid sponges and root tufts has been recovered from the upper Guadalupian Reef Trail Member of the Bell Canyon Formation, from the Patterson Hills, in the southwestern part of the Guadalupe Mountains National Park in western Texas. Some demosponges from the type section of the Reef Trail Member, near the mouth of McKittrick Canyon on the front of the Guadalupe Mountains in the park, have also been documented. Included in the faunule from the Patterson Hills localities are the new amphidiscosid hexactinellid pelicasponge Trailospongia reischi n. gen. and sp., the questionable pelicaspongiid Hexirregularia nana n. gen. and sp., and the dictyospongiid hexactinellids Microstaura doliolum Finks, 1960, and Microstaurella minima n. gen. and sp., and Microstaurella parva n. gen. and sp. They are associated with specimens of the lyssacinosid brachiosponges Toomeyospongiella gigantia Rigby and Bell, 2005, Toomeyospongia modica n. sp., and Toomeyospongia minuta n. gen. and sp., and fragments of three different types of root tufts, termed Tufts 1, 3, and 4. Two specimens of the new cylindrical demosponge Mckittrickella pratti n. gen. and sp. are associated with Tuft 2 in the collection from the type section of the Reef Trail Member, and a third specimen was collected from the member in the Patterson Hills. These sponges from Localities 1-7 are the youngest Permian sponges known from the region, and possibly from North America.

Unavailability of wind turbines due to wind-induced accelerations

The malfunctioning of acceleration-sensitive equipment in wind turbines has the potential to affect their annual failure rates during normal operating conditions. Current protective measures for wind turbines are triggered by wind speed. However, this option neglects the structural response of the wind turbines, and limits the possibility of effectively controlling accelerations at the top of the wind towers. In this study, a dynamic model of the wind tower/rotor blade system is used to estimate the acceleration response at the top of the towers. This model is coupled with a probabilistic description of the dynamic properties of the wind turbines, and an annual distribution of the wind hazard to obtain a distribution of the acceleration response for various levels of wind speed. This distribution is used to develop wind-induced acceleration fragility curves for typical wind turbines. Acceleration thresholds of 10, 15, and 20 m/s 2 are likely to be exceeded at the onset of protective cut out wind speeds of 25 m/s, with probabilities as high as 64%, 48%, and 37%, respectively. Several wind turbine subcomponents are sensitive to these levels of acceleration. Some examples, in decreasing order of acceleration susceptibility, include generators, brakes, yaw systems, inverters, mechanical controls, electrical controls, hydraulic systems, gearboxes, shafts, and physical/electrical connections to the power grid. By weighting the fragility curves with the likelihood of observing specific wind speeds during any given year, this study provides unconditional probabilities of failure that represent annual unavailability rates for wind turbines. Exceeding any of the acceleration levels between 10 m/s 2 and 20 m/s 2 has probabilities of 47% and 49% at two locations with different wind regimens: Western Texas, USA, and Northern Ireland. This annual unavailability rate indicates that almost half the units of a wind farm at either location are likely to experience abnormal operation owing to the demands on acceleration-sensitive equipment. The use of fragility curves and the risk of unavailability for wind turbines will continue to grow because they allow performance assessment of future systems which favor larger, more flexible, more massive, and more complex wind turbine units. These new generation units will be able to operate at higher wind speeds and more demanding environmental conditions. A short- term option to reduce acceleration-induced failures in built systems is to establish shutdown criteria based on acceleration, rather than just wind speed. However, long-term handling of acceleration-sensitive equipment requires fragility and reliability analysis at the design stage, and the use of actively controlled protective devices.