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Sample records for american southwest desert

  1. Foraging behavior of heritage versus recently introduced herbivores on desert landscapes of the American Southwest

    Science.gov (United States)

    Since the 1800s managed grasslands and shrublands of the arid American Southwest have been grazed predominantly by cattle originally bred for temperate climates in northern Europe. A heritage breed, the criollo cattle, has survived in northern Mexico for more than 400 years under desert-like conditi...

  2. Effects of rapid urbanization on streamflow, erosion, and sedimentation in a desert stream in the American Southwest

    Science.gov (United States)

    Whitney, John W.; Glancy, Patrick A.; Buckingham , Susan E.; Ehrenberg, Arthur C.

    2015-01-01

    Rapid urbanization has resulted in a series of sequential effects on a desert stream in the American Southwest. Lower Las Vegas Wash was a dry wash characterized by infrequent flood deposition when Las Vegas, Nevada was established in 1905. Wastewater effluent was discharged into the wash in low volumes for over 3 decades. Wastewater volumes increased commensurably with accelerated population growth during the late 20th century and created a sequence of feedback effects on the floodplain. Initially slow saturation of the valley fill created a desert oasis of dense floodplain vegetation and wetlands. Annual streamflow began in 1958 and erosion began a decade later with shallow incision in discontinuous channel segments. Increasing baseflow gradually enlarged channels; headcutting was active during the 1970s to 1984. The incised channels concentrated storm runoff, which accelerated local channel erosion, and in 1984 the headcuts were integrated during a series of monsoon floods. Wetlands were drained and most floodplain vegetation destroyed. Channel erosion continued unabated until engineering interventions began in the 21st century. No natural channel recovery occurred after initial urbanization effects because streamflow never stabilized in the late 20th century. A 6.6 M m3 sediment slug, eroded from the wash in ∼25 years, was deposited in Las Vegas Bay in Lake Mead. Falling reservoir levels during the 21st century are responsible for sediment redistribution and infilling of the bay. Close monitoring of impacts is recommended when urban wastewater and storm runoff are discharged on a desert wash. Channel interventions, when necessary, are advised in order to prevent costly engineering schemes of channel stabilization, flood control, and floodplain restoration.

  3. AMS {sup 14}C dating of early Anasazi petroglyphs from the North American southwest desert region

    Energy Technology Data Exchange (ETDEWEB)

    Beck, W.; Donahue, D.; Burr, G.; Jull, A.J.T. [Arizona State Univ., Tempe, AZ (United States). Dept. of Physics

    1997-12-31

    Full text: Since it was first developed in the early 1980`s, direct dating of rock surfaces by AMS radiocarbon analysis has become an integral tool in the fields of geomorphology and archaeology. Recently, the AMS Laboratory at the University of Arizona has become directly involved in a series of measurements in an attempt to determine the age of the petroglyphs found in the Petrified Forest region of NE Arizona, in the American Southwest. There are several generations of these petroglyphs, the most recent of these have been ascribed to the so-called Pueblo Indians which lived in this region between 700-1450 AD. Three earlier epochs of petroglyph makers also inhabited this region which have been grouped into the Basketmaker, Archaic, and Paleo-Indian periods. This original focus of this study was an attempt to identify the timing of development of the Paleo-Indian and Archaic Indian styles of petroglyphs from this region using AMS {sup 14}C measurements. Microscopic examination of samples from these petroglyphs, showed that the samples contained two types of black, carbon-rich materials with distinctly different visual properties. Detailed examination of these particles reveal that one type strongly resembles finely ground bituminous coal, whereas the other strongly resembles ground pyrolized wood. Subsequent measurements of the radiocarbon contents of separated fractions of the two types of materials have shown that they have widely differing radiocarbon ages. In such cases, the radiocarbon age of the entire sample would yield results which are, at best, ambiguous.

  4. Desert basins of the Southwest

    Science.gov (United States)

    Leake, Stanley A.; Konieczki, Alice D.; Rees, Julie A.H.

    2000-01-01

    Ground water is among the Nation’s most important natural resources. It provides drinking water to urban and rural communities, supports irrigation and industry, sustains the flow of streams and rivers, and maintains riparian and wetland ecosystems. In many areas of the Nation, the future sustainability of ground-water resources is at risk from overuse and contamination. Because ground-water systems typically respond slowly to human actions, a long-term perspective is needed to manage this valuable resource. This publication is one in a series of fact sheets that describe ground-water-resource issues across the United States, as well as some of the activities of the U.S. Geological Survey that provide information to help others develop, manage, and protect ground-water resources in a sustainable manner. Ground-water resources in the Southwest are among the most overused in the United States. Natural recharge to aquifers is low and pumping in many areas has resulted in lowering of water tables. The consequences of large-scale removal of water from storage are becoming increasingly evident. These consequences include land subsidence; loss of springs, streams, wetlands and associated habitat; and degradation of water quality. Water managers are now seeking better ways of managing ground-water resources while looking for supplemental sources of water. This fact sheet reviews basic information on ground water in the desert basins of the Southwest. Also described are some activities of the U.S. Geological Survey (USGS) that are providing scientific information for sustainable management of ground-water resources in the Southwest. Ground-water sustainability is defined as developing and using ground water in a way that can be maintained for an indefinite time without causing unacceptable environmental, economic, or social consequences.

  5. Collection Development "Southwest Gardening": The Desert Shall Bloom

    Science.gov (United States)

    Charles, John; Mosley, Shelley; Van Winkle, Sandra

    2008-01-01

    Gardening in the American Southwest (SW) is an extreme sport. Not only are gardeners challenged by geographic extremes from tropical deserts to subalpine locales, they must also deal with a wide range of climates. Winter in the mountains and higher regions means heavy snows, frozen soils, and temperatures that can dip below zero. In contrast,…

  6. 76 FR 59682 - Desert Southwest Customer Service Region-Western Area Lower Colorado Balancing Authority-Rate...

    Science.gov (United States)

    2011-09-27

    ... Area Power Administration Desert Southwest Customer Service Region--Western Area Lower Colorado... the Western Area Power Administration's (Western) Desert Southwest Customer Service Region (DSWR... Murray, Rates Manager, Desert Southwest Customer Service Region, Western Area Power Administration,...

  7. Mitigating Climate Change in the American Southwest

    Science.gov (United States)

    McCarthy, Patrick D.; Enquist, Carolyn A. F.; Garfin, Gregg

    2008-01-01

    New Mexico Climate Change Ecology and Adaptation Workshop; Albuquerque, New Mexico, 22 October 2007; Climate change has had greater impacts on the American Southwest than perhaps anywhere else in the contiguous United States. The future likely holds even more dramatic impacts for the region's ecosystems. Managers of deserts, forests, grasslands, rivers, and streams in this vast and scenic region are under pressure to respond to the unprecedented wildfires, forest dieback, and insect outbreaks that have resulted from years of record warm temperatures and drought. Already faced with urban encroachment and water shortages, managers need to better understand the regional implications of global climate change in order to take informed action to build the adaptive capacity of the landscapes that provide ecosystem services to our communities and habitat for a great diversity of species.

  8. Dramatic Demand Reduction In The Desert Southwest

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert [Univ. of Nevada, Las Vegas, NV (United States); Hsieh, Sean [Univ. of Nevada, Las Vegas, NV (United States); Lee, Joon [Univ. of Nevada, Las Vegas, NV (United States); Baghzouz, Yahia [Univ. of Nevada, Las Vegas, NV (United States); Cross, Andrew [Univ. of Nevada, Las Vegas, NV (United States); Chatterjee, Sarah [NV Energy, Las Vegas, NV (United States)

    2015-07-06

    This report summarizes a project that was funded to the University of Nevada Las Vegas (UNLV), with subcontractors Pulte Homes and NV Energy. The project was motivated by the fact that locations in the Desert Southwest portion of the US demonstrate very high peak electrical demands, typically in the late afternoons in the summer. These high demands often require high priced power to supply the needs, and the large loads can cause grid supply problems. An approach was proposed through this contact that would reduce the peak electrical demands to an anticipated 65% of what code-built houses of the similar size would have. It was proposed to achieve energy reduction through four approaches applied to a development of 185 homes in northwest part of Las Vegas named Villa Trieste. First, the homes would all be highly energy efficient. Secondly, each house would have a PV array installed on it. Third, an advanced demand response technique would be developed to allow the resident to have some control over the energy used. Finally, some type of battery storage would be used in the project. Pulte Homes designed the houses. The company considered initial cost vs. long-term savings and chose options that had relatively short paybacks. HERS (Home Energy Rating Service) ratings for the homes are approximately 43 on this scale. On this scale, code-built homes rate at 100, zero energy homes rate a 0, and Energy Star homes are 85. In addition a 1.764 Wp (peak Watt) rated PV array was used on each house. This was made up of solar shakes that were in visual harmony with the roofing material used. A demand response tool was developed to control the amount of electricity used during times of peak demand. While demand response techniques have been used in the utility industry for some time, this particular approach is designed to allow the customer to decide the degree of participation in the response activity. The temperature change in the residence can be decided by the residents by

  9. Dramatic Demand Reduction In The Desert Southwest

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert [Univ. of Nevada, Las Vegas, NV (United States); Hsieh, Sean [Univ. of Nevada, Las Vegas, NV (United States); Lee, Joon [Univ. of Nevada, Las Vegas, NV (United States); Baghzouz, Yahia [Univ. of Nevada, Las Vegas, NV (United States); Cross, Andrew [Univ. of Nevada, Las Vegas, NV (United States); Chatterjee, Sarah [NV Energy, Las Vegas, NV (United States)

    2015-07-06

    This report summarizes a project that was funded to the University of Nevada Las Vegas (UNLV), with subcontractors Pulte Homes and NV Energy. The project was motivated by the fact that locations in the Desert Southwest portion of the US demonstrate very high peak electrical demands, typically in the late afternoons in the summer. These high demands often require high priced power to supply the needs, and the large loads can cause grid supply problems. An approach was proposed through this contact that would reduce the peak electrical demands to an anticipated 65% of what code-built houses of the similar size would have. It was proposed to achieve energy reduction through four approaches applied to a development of 185 homes in northwest part of Las Vegas named Villa Trieste. First, the homes would all be highly energy efficient. Secondly, each house would have a PV array installed on it. Third, an advanced demand response technique would be developed to allow the resident to have some control over the energy used. Finally, some type of battery storage would be used in the project. Pulte Homes designed the houses. The company considered initial cost vs. long-term savings and chose options that had relatively short paybacks. HERS (Home Energy Rating Service) ratings for the homes are approximately 43 on this scale. On this scale, code-built homes rate at 100, zero energy homes rate a 0, and Energy Star homes are 85. In addition a 1.764 Wp (peak Watt) rated PV array was used on each house. This was made up of solar shakes that were in visual harmony with the roofing material used. A demand response tool was developed to control the amount of electricity used during times of peak demand. While demand response techniques have been used in the utility industry for some time, this particular approach is designed to allow the customer to decide the degree of participation in the response activity. The temperature change in the residence can be decided by the residents by

  10. Chemical mass balance source apportionment of fine and PM10 in the Desert Southwest, USA

    Science.gov (United States)

    The Desert Southwest Coarse Particulate Matter Study was undertaken in Pinal County, Arizona, to better understand the origin and impact of sources of fine and coarse particulate matter (PM) in rural, arid regions of the U.S. southwestern desert. The desert southwest experiences ...

  11. 76 FR 28767 - Desert Southwest Customer Service Region-Rate Order No. WAPA-152

    Science.gov (United States)

    2011-05-18

    ... Area Power Administration Desert Southwest Customer Service Region-Rate Order No. WAPA-152 AGENCY: Western Area Power Administration, DOE. ACTION: Notice of Rate Order Temporarily Extending Network... Region, Western Area Power Administration, P.O. Box 6457, Phoenix, AZ 85005-6457, (602) 605-2522,...

  12. Chemical mass balance source apportionment of fine and PM10 in the Desert Southwest, USA

    Directory of Open Access Journals (Sweden)

    Andrea L. Clements

    2016-03-01

    Full Text Available The Desert Southwest Coarse Particulate Matter Study was undertaken in Pinal County, Arizona, to better understand the origin and impact of sources of fine and coarse particulate matter (PM in rural, arid regions of the U.S. southwestern desert. The desert southwest experiences some of the highest PM10 mass concentrations in the country. To augment previously reported results, 6-week aggregated organic speciation data that included ambient concentrations of n-alkanes, polycyclic aromatic hydrocarbons, organic acids, and saccharides were used in chemical mass balance modeling (CMB. A set of re-suspended soil samples were analyzed for specific marker species to provide locally-appropriate source profiles for the CMB analysis. These profiles, as well as previously collected plant and fungal spore profiles from the region, were combined with published source profiles for other relevant sources and used in the CMB analysis. The six new region-specific source profiles included both organic and inorganic species for four crustal material sources, one plant detritus source, and one fungal spore source.Results indicate that up to half of the ambient PM2.5 was apportioned to motor vehicles with the highest regional contribution observed in the small urban center of Casa Grande. Daily levels of apportioned crustal material accounted for up to 50% of PM2.5 mass with the highest contributions observed at the sites closest to active agricultural areas. Apportioned secondary PM, biomass burning, and road dust typically contributed less than 35% as a group to the apportioned PM2.5 mass. Crustal material was the primary source apportioned to PM10 and accounted for between 50–90% of the apportioned mass. Of the other sources apportioned to PM10, motor vehicles and road dust were the largest contributors at the urban and one of the rural sites, whereas road dust and meat cooking operations were the largest contributors at the other rural site.

  13. Mexican Americans: Sons of the Southwest.

    Science.gov (United States)

    Lamb, Ruth S.

    Concerned with the Mexican Americans, who constitute the largest ethnic group in the southwestern United States, this book traces the history of these people from the early explorations and colonizing efforts of the Spanish in North and South America during the 16th century to the present. Major divisions of this book are the Introduction,…

  14. Evidence of Aqueous Secondary Organic Aerosol Formation from Biogenic Emissions in the North American Sonoran Desert

    Science.gov (United States)

    Sorooshian, A.; Youn, J.; Wang, Z.; Wonaschuetz, A.; Arellano, A. F.; Betterton, E. A.

    2013-12-01

    This study examines the role of aqueous secondary organic aerosol (SOA) formation in the North American Sonoran Desert as a result of intense solar radiation, enhanced moisture, and biogenic volatile organic compounds (BVOCs). The ratio of water-soluble organic carbon (WSOC) to organic carbon (OC) nearly doubles during the monsoon season relative to other seasons of the year. When normalized by mixing height, the WSOC enhancement during monsoon months relative to preceding dry months (May - June) exceeds that of sulfate by nearly a factor of ten. WSOC:OC and WSOC are most strongly correlated with moisture parameters, temperature, and concentrations of ozone and BVOCs. No positive relationship was identified between WSOC or WSOC:OC and anthropogenic tracers such as carbon monoxide over a full year. These results are especially of significance as recent modeling studies suggest that aqueous SOA formation is geographically concentrated in the eastern United States and likely unimportant in other areas such as the Southwest.

  15. Overcrowded motor vehicle trauma from the smuggling of illegal immigrants in the desert of the Southwest.

    Science.gov (United States)

    Lumpkin, Mary F; Judkins, Dan; Porter, John M; Latifi, Rifat; Williams, Mark D

    2004-12-01

    Overcrowded motor vehicle crashes caused by the very active criminal enterprise of smuggling illegal immigrants in the desert of the Southwest is a recent and under-recognized trauma etiology. A computerized database search from 1990 through 2003 of local newspaper reports of overcrowded motor vehicle crashes along the 281 miles of Arizona's border with Mexico was conducted. This area was covered by two level I trauma centers, but since July 2003 is now served only by the University Medical Center. Each of these crashes involved a single motor vehicle in poor mechanical shape packed with illegal immigrants. Speeding out of control on bad tires, high-speed rollovers result in ejection of most passengers. Since 1999, there have been 38 crashes involving 663 passengers (an average of 17 per vehicle) with an injury rate of 49 per cent and a mortality rate of 9 per cent. This relatively recent phenomenon (no reports from before 1998) of trauma resulting from human smuggling is lethal and demonstrates the smugglers' wanton disregard for human life, particularly when facing apprehension. Even a few innocent bystanders have been killed. These crashes overwhelm a region's trauma resources and must be recognized when planning the distribution of trauma resources to border states.

  16. South American mammal zoogeography: evidence from convergent evolution in desert rodents.

    Science.gov (United States)

    Mares, M A

    1975-05-01

    Current theories regarding colonization of South America by mammals are divided between those supported by fossil evidence, which suggest the original mammal fauna of the isolated continent was augmented by early immigrants (primates, caviomorph rodents, and later, procyonids) with a final large influx of northern mammals occurring with the formation of the Panama land bridge, and an opposing view which states that the purported "recent invaders" are too taxonomically and ecologically differentiated to have colonized since the land bridge arose. The second theory suggests that most extant mammals entered before the Plio-Pleistocene land connection. An analysis of degree of physiological adaptation, natural history, distribution patterns, and a multivariate assessment of convergent evolution of Monte Desert rodents indicate that South American cricetine rodents are not highly specialized for desert life. Their degree of adaptation could be accounted for, in large part, by adaptations for arid or semiarid Andean habitats. No Monte Desert rodent has developed the specialized desert traits that have evolved in most desert rodent faunas of the world, although extinct marsupials similar to living bipedal desert rodents were present in the Monte as recently as late Pliocene. Evidence suggests that Monte caviomorphs have been associated with the desert for a longer period than cricetines, and that the latter represent a fairly recent invasion of the Monte Desert. The data thus support the first hypothesis of South American mammal colonization.

  17. Preferred Drug Resistance Strategies of Urban American Indian Youth of the Southwest

    Science.gov (United States)

    Kulis, Stephen; Brown, Eddie F.

    2011-01-01

    This study explored the drug resistance strategies that urban American Indian adolescents consider the best and worst ways to respond to offers of alcohol, cigarettes, and marijuana. Focus group data were collected from 11 female and 9 male American Indian adolescents attending urban middle schools in the southwest. The youth were presented with…

  18. Phylogeography of Declining Relict and Lowland Leopard Frogs in the Desert Southwest of North America

    Science.gov (United States)

    We investigated the phylogeography of the closely related relict leopard frog (Rana onca) and lowland leopard frog (R. yavapaiensis) – two declining anurans from the warm-desert regions of southwestern North America. We used sequence data from two mitochondrial DNA genes to asses...

  19. Regional Landscape System Protection in the Urbanising Desert Southwest: Lessons from the Phoenix Metropolitan Region, USA

    Directory of Open Access Journals (Sweden)

    Laura Musacchio

    2004-12-01

    Full Text Available Through the lens of holistic landscape ecology, the authors present for public consideration a desert landscape typology and plan assessment criteria. As a case study, historical trends in open space planning and two contrasting examples of recent open space plans from the Phoenix metropolitan area were analysed and compared to the typology in order to understand how successfully the open space planning efforts had addressed protection of the regional landscape system in the Sonoran Desert. We also developed an approach for the analysis of the landscape ecological component of plans that was based on Baer's general plan assessment criteria (1997. Our results indicate the desert landscape typology is a valuable step as part of a plan assessment of two regional, open space plans, but more importantly, the assessment criteria presented in this paper could be used as the foundation for a more thorough assessment method of the landscape ecological component of plans. The desert landscape typology and plan assessment criteria presented in this paper can be used to increase understanding about how the decision making of planners and designers has influenced the temporal and spatial dimensions of landscape legacies, trajectories and transformations, such as connectivity and fragmentation of open space.

  20. Hidden Scholars: Woman Anthropologists and the Native American Southwest, edited by Nancy J. Parezo. Foreword by Nathalie F. S. Woodbury and Richard B. Woodbury. University of New Mexico Press, Albuquer­que. 1993

    Directory of Open Access Journals (Sweden)

    Jonathan E. Reyman

    1994-05-01

    Full Text Available A public conference followed by a scholarly symposium was held at Tucson, AZ in March 1986. Co-sponsored by the Wenner-Gren Foundation for Anthropological Research, The Southwest Institute for Research on Women, the Arizona State Museum, and the Department of Anthropology and the Southwest Center at the University of Arizona, "Daughters of the Desert" brought together more than 20 scholars to discuss the history of women in southwestern anthropology. The conference included an exhibit with an illustrated catalogue: Daughters of the Desert (Babcock and Parezo 1988. Now, with the publication of Hidden Scholars: Woman Anthropologists and the Native American Southwest, we have, as the Woodburys state in their Foreword, "a comprehensive survey of southwestern anthropology" with an expanded history and biographical profiles of some 50-60 of the most important of the more than 1,600 women who have worked in southwestern anthropol­ogy.This volume appears when there is renewed interest in the history of anthropology, the history of women within anthropology (especially American anthropology, and the issue of gender in archaeological research. Recent symposia and conferences have focused on these topics, e.g., ''Women in Archaeology: The Second Annual Symposium on the History of American Archaeology" held at the 54th Annual Meeting of the Society for American Archaeology (April 1989, and the entire 22nd Annual Chacmool Conference (November 1989.

  1. Blood group comparisons between European mouflon sheep and north American desert bighorn sheep.

    Science.gov (United States)

    Bunch, T D; Nguyen, T C

    1982-01-01

    Blood group systems in true sheep (Ovis) provide an additional method by which phylogenetic relationships can be measured. Of the eight genetic systems of blood groups identified in domestic sheep, all appeared to have their homologue in European mouflons and at least six might have their equivalent in North American desert bighorns. The red cells of the European mouflon, which is believed to be ancestral to domestic sheep, cross-reacted with domestic sheep blood-group typing reagents much more strongly and extensively than did the red cells of desert bighorn sheep. It also was noted that all the Mexican desert bighorns tested were Da positive, but their blood factor was not observed in the Nelson desert bighorns sampled. This observation indicated that the two subspecies might differ from each other with respect to the D blood group system. Transferrin type D was observed in the mouflons, while Tfs D and E were in the desert bighorns. Hemoglobins B and AB were observed in the mouflons but only Hb B occurred in the desert bighorns. The systematic implications of blood group polymorphisms are discussed.

  2. PLUTONIUM UPTAKE AND BEHAVIOR IN PLANTS OF THE DESERT SOUTHWEST: A PRELIMINARY ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, E.; Duff, M.; Ferguson, C.

    2011-03-01

    Eight species of desert vegetation and associated soils were collected from the Nevada National Security Site (N2S2) and analyzed for 238Pu and 239+240Pu concentrations. Amongst the plant species sampled were: atmospheric elemental accumulators (moss and lichen), the very slow growing, long-lived creosote bush and the rapidly growing, short-lived cheatgrass brome. The diversity of growth strategies provided insight into the geochemical behavior and bio-availability of Pu at the N2S2. The highest concentrations of Pu were measured in the onion moss (24.27 Bq kg-1 238Pu and 52.78 Bq kg-1 239+240Pu) followed by the rimmed navel lichen (8.18 Bq kg-1 and 18.4 Bq kg-1 respectively), pointing to the importance of eolian transport of Pu. Brome and desert globemallow accumulated between 3 and 9 times higher concentrations of Pu than creosote and sage brush species. These results support the importance of species specific elemental accumulation strategies rather than exposure duration as the dominant variable influencing Pu concentrations in these plants. Total vegetation elemental concentrations of Ce, Fe, Al, Sm and others were also analyzed. Strong correlations were observed between Fe and Pu. This supports the conclusion that Pu was accumulated as a consequence of the active accumulation of Fe and other plant required nutrients. Cerium and Pu are considered to be chemical analogs. Strong correlations observed in plants support the conclusion that these elements displayed similar geochemical behavior in the environment as it related to the biochemical uptake process of vegetation. Soils were also sampled in association with vegetation samples. This allowed for the calculation of a concentration ratio (CR). The CR values for Pu in plants were highly influenced by the heterogeneity of Pu distribution among sites. Results from the naturally occurring elements of concern were more evenly distributed between sample sites. This allowed for the development of a pattern of plant

  3. Legally White, Socially "Mexican": The Politics of De Jure and De Facto School Segregation in the American Southwest

    Science.gov (United States)

    Donato, Ruben; Hanson, Jarrod S.

    2012-01-01

    The history of Mexican American school segregation is complex, often misunderstood, and currently unresolved. The literature suggests that Mexican Americans experienced de facto segregation because it was local custom and never sanctioned at the state level in the American Southwest. However, the same literature suggests that Mexican Americans…

  4. From the Treaty of Guadalupe Hidalgo to "Hopwood": The Educational Plight and Struggle of Mexican Americans in the Southwest.

    Science.gov (United States)

    Valencia, Richard R.; San Miguel, Guadalupe, Jr.

    1998-01-01

    Describes four eras in Mexican-American education: (1) schooling in the Southwest, 1848-1890; (2) expansion of Mexican-American education, 1890-1930; (3) changing nature of public education, 1930-1960; and (4) the contemporary period. Explores such themes as exclusion, segregated and inferior schooling, and nativism. (SK)

  5. Cross-sectional geometry in the humeri of foragers and farmers from the prehispanic American Southwest: exploring patterns in the sexual division of labor.

    Science.gov (United States)

    Ogilvie, Marsha D; Hilton, Charles E

    2011-01-01

    The work effort of prehistoric males relative to females has long been of interest to anthropologists, particularly in foraging versus farming groups. This knowledge requires a clear understanding of the sexual division of labor, or the dichotomy in subsistence roles allocated to males and females. Such research in the Prehispanic American Southwest has been limited. As previous work has shown that bone is the osseous template that reflects in vivo activity levels, it is possible to assess gender-based differences in past work effort using analyses of geometric properties of bone and calculations of bilateral asymmetry. Our research comparatively analyzed upper limb work effort by sex and subsistence in two skeletal samples from disparate economic groups, foragers and farmers, both from similar desert environments. The residentially mobile foragers are from the Lower Pecos region of southwest Texas and the farmers are from the aggregated pueblo of Pottery Mound in south central New Mexico. Humeri from 27 adult foragers (n = 11 males; n = 17 females) and 65 adult farmers (n = 38 males; n = 27 females) were selected for study. All humeri were radiographed and/or scanned and digitized. Statistical comparisons using two-way ANOVAs indicate that female farmers exhibited the greatest humeral strength and the least asymmetry. Relative to all other groups examined, female farmers engaged in higher levels of upper limb work effort implying a substantial economic contribution to their agricultural economy.

  6. Abstracts for the October 2012 meeting on Volcanism in the American Southwest, Flagstaff, Arizona

    Science.gov (United States)

    Lowenstern, Jacob B.

    2013-01-01

    Though volcanic eruptions are comparatively rare in the American Southwest, the States of Arizona, Colorado, New Mexico, Nevada, and Utah host Holocene volcanic eruption deposits and are vulnerable to future volcanic activity. Compared with other parts of the western United States, comparatively little research has been focused on this area, and eruption probabilities are poorly constrained. Monitoring infrastructure consists of a variety of local seismic networks, and ”backbone“ geodetic networks with little integration. Emergency response planning for volcanic unrest has received little attention by either Federal or State agencies. On October 18–20, 2012, 90 people met at the U.S. Geological Survey campus in Flagstaff, Arizona, providing an opportunity for volcanologists, land managers, and emergency responders to meet, converse, and begin to plan protocols for any future activity. Geologists contributed data on recent findings of eruptive ages, eruption probabilities, and hazards extents (plume heights, ash dispersal). Geophysicists discussed evidence for magma intrusions from seismic, geodetic, and other geophysical techniques. Network operators publicized their recent work and the relevance of their equipment to volcanic regions. Land managers and emergency responders shared their experiences with emergency planning for earthquakes. The meeting was organized out of the recognition that little attention had been paid to planning for or mitigation of volcanic hazards in the American Southwest. Moreover, few geological meetings have hosted a session specifically devoted to this topic. This volume represents one official outcome of the meeting—a collection of abstracts related to talks and poster presentations shared during the first two days of the meeting. In addition, this report includes the meeting agenda as a record of the proceedings. One additional intended outcome will be greater discussion and coordination among emergency responders, geologists

  7. Jojoba: North American desert shrub; its ecology, possible commercialization, and potential as an introduction into other arid regions. [Simmondsia chinensis

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, W.H.

    1978-09-01

    Jojoba (Simmondsia chinensis (Link.) Schneid.), a North American desert shrub, is the only plant known to produce a liquid wax in its seed. This substance is chemically similar to the oil from the Sperm whale. Industrial and agronomic uses are described as well as currently known economic factors regarding agronomic production. The plants' present distribution is linked with the winter-spring rains of a Mediterranean type of climate in the Sonoran Desert regions of the United States and Sonora and Baja California in Mexico. It is suggested that other arid regions may be quite suitable to its introduction, particularly portions of the Asir Province in western Saudi Arabia.

  8. Projected vegetation changes for the American Southwest: combined dynamic modeling and bioclimatic-envelope approach.

    Science.gov (United States)

    Notaro, Michael; Mauss, Adrien; Williams, John W

    2012-06-01

    This study focuses on potential impacts of 21st century climate change on vegetation in the Southwest United States, based on debiased and interpolated climate projections from 17 global climate models used in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Among these models a warming trend is universal, but projected changes in precipitation vary in sign and magnitude. Two independent methods are applied: a dynamic global vegetation model to assess changes in plant functional types and bioclimatic envelope modeling to assess changes in individual tree and shrub species and biodiversity. The former approach investigates broad responses of plant functional types to climate change, while considering competition, disturbances, and carbon fertilization, while the latter approach focuses on the response of individual plant species, and net biodiversity, to climate change. The dynamic model simulates a region-wide reduction in vegetation cover during the 21st century, with a partial replacement of evergreen trees with grasses in the mountains of Colorado and Utah, except at the highest elevations, where tree cover increases. Across southern Arizona, central New Mexico, and eastern Colorado, grass cover declines, in some cases abruptly. Due to the prevalent warming trend among all 17 climate models, vegetation cover declines in the 21st century, with the greatest vegetation losses associated with models that project a drying trend. The inclusion of the carbon fertilization effect largely ameliorates the projected vegetation loss. Based on bioclimatic envelope modeling for the 21st century, the number of tree and shrub species that are expected to experience robust declines in range likely outweighs the number of species that are expected to expand in range. Dramatic shifts in plant species richness are projected, with declines in the high-elevation evergreen forests, increases in the eastern New Mexico prairies, and a northward shift of the

  9. Native American depopulation, reforestation, and fire regimes in the Southwest United States, 1492-1900 CE.

    Science.gov (United States)

    Liebmann, Matthew J; Farella, Joshua; Roos, Christopher I; Stack, Adam; Martini, Sarah; Swetnam, Thomas W

    2016-02-01

    Native American populations declined between 1492 and 1900 CE, instigated by the European colonization of the Americas. However, the magnitude, tempo, and ecological effects of this depopulation remain the source of enduring debates. Recently, scholars have linked indigenous demographic decline, Neotropical reforestation, and shifting fire regimes to global changes in climate, atmosphere, and the Early Anthropocene hypothesis. In light of these studies, we assess these processes in conifer-dominated forests of the Southwest United States. We compare light detection and ranging data, archaeology, dendrochronology, and historical records from the Jemez Province of New Mexico to quantify population losses, establish dates of depopulation events, and determine the extent and timing of forest regrowth and fire regimes between 1492 and 1900. We present a new formula for the estimation of Pueblo population based on architectural remains and apply this formula to 18 archaeological sites in the Jemez Province. A dendrochronological study of remnant wood establishes dates of terminal occupation at these sites. By combining our results with historical records, we report a model of pre- and post-Columbian population dynamics in the Jemez Province. Our results indicate that the indigenous population of the Jemez Province declined by 87% following European colonization but that this reduction occurred nearly a century after initial contact. Depopulation also triggered an increase in the frequency of extensive surface fires between 1640 and 1900. Ultimately, this study illustrates the quality of integrated archaeological and paleoecological data needed to assess the links between Native American population decline and ecological change after European contact.

  10. An Ecohydrological Approach to Riparian Restoration Planning in the American Southwest

    Science.gov (United States)

    Leverich, G. T.; Orr, B.; Diggory, Z.; Dudley, T.; Hatten, J.; Hultine, K. R.; Johnson, M. P.; Orr, D.

    2014-12-01

    Riparian systems across the American southwest region are under threat from a growing and intertwined cast of natural and anthropogenic stressors, including flooding, drought, invasion by non-native plants, wildfire, urban encroachment, and land- and water-use practices. In relatively remote and unregulated systems like the upper Gila River in Arizona, riparian habitat value has persisted reasonably well despite much of it being densely infested with non-native tamarisk (salt cedar). A new concern in the watershed, however, is the eventual arrival of the tamarisk leaf beetle that is expected to soon colonize the tamarisk-infested riparian corridor as the beetle continues to spread across the southwest region. While there are numerous potential benefits to tamarisk suppression (e.g., groundwater conservation, riparian habitat recovery, fire-risk reduction), short-term negative consequences are also possible, such as altered channel hydraulics and canopy defoliation during bird nesting season (e.g., the endangered southwestern willow flycatcher). In preparation for anticipated impacts following beetle colonization, we developed a holistic restoration framework to promote recovery of native riparian habitat and subsequent local increases in avian population. Pivotal to this process was an ecohydrological assessment that identified sustainable restoration sites based on consideration of natural and anthropogenic factors that, together, influence restoration opportunities—flood-scour dynamics, vegetation community structure and resilience, surface- and groundwater availability, soil texture and salinity, wildfire potential, and land-use activities. Data collected included high-resolution remote-sensing products, GIS-based delineation of geomorphic activity, and vegetation field mapping. These data along with other information generated, including pre-biocontrol vegetation monitoring and flycatcher-habitat modeling, were synthesized to produce a comprehensive

  11. Severe mortality of a population of threatened Agassiz’s desert tortoises: the American badger as a potential predator

    Science.gov (United States)

    Emblidge, Patrick G.; Nussear, Ken E.; Esque, Todd C.; Aiello, Christina M.; Walde, Andrew D.

    2015-01-01

    In the Mojave Desert of the southwestern United States, adult Agassiz’s desert tortoises Gopherus agassizii typically experience high survival, but population declines associated with anthropogenic impacts led to their listing as a threatened Species under the US Endangered Species Act in 1990. Predation of adult tortoises is not often considered a significant threat as they are adapted to deter most predation attempts. Despite these adaptations, some populations have experienced elevated mortality attributed to predators, suggesting that predation pressure may occasionally increase. During the tortoise activity seasons of 2012 and 2013, we observed unsustainably high mortality in 1 of 4 populations of adult desert tortoises (22 and 84%, respectively) in the western Mojave Desert in the vicinity of Barstow, CA. Photographic evidence from trail cameras and examination of carcass condition suggest that American badgers Taxidea taxus— a sometimes cited but unconfirmed predator of adult tortoises — may have been responsible for some of the mortality observed. We discuss the American badger as a plausible predator of a local tortoise population, but recommend further investigation into these events and the impacts such mortality can have on tortoise persistence.

  12. Native American depopulation, reforestation, and fire regimes in the Southwest United States, 1492–1900 CE

    Science.gov (United States)

    Liebmann, Matthew J.; Farella, Joshua; Roos, Christopher I.; Stack, Adam; Martini, Sarah

    2016-01-01

    Native American populations declined between 1492 and 1900 CE, instigated by the European colonization of the Americas. However, the magnitude, tempo, and ecological effects of this depopulation remain the source of enduring debates. Recently, scholars have linked indigenous demographic decline, Neotropical reforestation, and shifting fire regimes to global changes in climate, atmosphere, and the Early Anthropocene hypothesis. In light of these studies, we assess these processes in conifer-dominated forests of the Southwest United States. We compare light detection and ranging data, archaeology, dendrochronology, and historical records from the Jemez Province of New Mexico to quantify population losses, establish dates of depopulation events, and determine the extent and timing of forest regrowth and fire regimes between 1492 and 1900. We present a new formula for the estimation of Pueblo population based on architectural remains and apply this formula to 18 archaeological sites in the Jemez Province. A dendrochronological study of remnant wood establishes dates of terminal occupation at these sites. By combining our results with historical records, we report a model of pre- and post-Columbian population dynamics in the Jemez Province. Our results indicate that the indigenous population of the Jemez Province declined by 87% following European colonization but that this reduction occurred nearly a century after initial contact. Depopulation also triggered an increase in the frequency of extensive surface fires between 1640 and 1900. Ultimately, this study illustrates the quality of integrated archaeological and paleoecological data needed to assess the links between Native American population decline and ecological change after European contact. PMID:26811459

  13. Landscape ecology of plague in the American southwest, September 19-20, 2000, Fort Collins, Colorado

    Science.gov (United States)

    Brand, Christopher J.

    2002-01-01

    During September 19-20, 2000, a workshop titled "Landscape Ecology of Plague in the American Southwest" was held in Fort Collins, Colorado. The workshop was funded by the U.S. Geological Survey (USGS)-Earth Surface Processes Team and sponsored by the USGS National Wildlife Health Center. Forty scientists and natural resource managers and administrators representing 8 federal agencies, 4 state agencies, 6 universities, and other local agencies and nongovernment organizations met to discuss historical and current status of plague in the United States, current activities in plague surveillance, research, and management in wildlife, and research and information needs relative to plague control and management. Eleven individual presentations on plague history, status, and trends; diagnostic technologies; epizootiological studies and observations; and control and management strategies and studies, followed by a panel discussion on the impact of plague on wildlife and ecosystems, led the way to extensive group discussions on important plague-related questions, issues and problems. Workshop attendees participated in identifying important research and information needs relevant to control and management of plague in wildlife, and in the process, established new cooperative and collaborative partnerships and enhanced existing relationships upon which future research and information needs can be met. The proceedings from this workshop are intended to be used by the natural resource managers and researchers from the various participating agencies, research facilities, as well as other stakeholders to aid in the development of future research and information programs and funding initiatives related to both zoonotic and sylvatic plague.

  14. Relative impacts of mitigation, temperature, and precipitation on 21st-century megadrought risk in the American Southwest.

    Science.gov (United States)

    Ault, Toby R; Mankin, Justin S; Cook, Benjamin I; Smerdon, Jason E

    2016-10-01

    Megadroughts are comparable in severity to the worst droughts of the 20th century but are of much longer duration. A megadrought in the American Southwest would impose unprecedented stress on the limited water resources of the area, making it critical to evaluate future risks not only under different climate change mitigation scenarios but also for different aspects of regional hydroclimate. We find that changes in the mean hydroclimate state, rather than its variability, determine megadrought risk in the American Southwest. Estimates of megadrought probabilities based on precipitation alone tend to underestimate risk. Furthermore, business-as-usual emissions of greenhouse gases will drive regional warming and drying, regardless of large precipitation uncertainties. We find that regional temperature increases alone push megadrought risk above 70, 90, or 99% by the end of the century, even if precipitation increases moderately, does not change, or decreases, respectively. Although each possibility is supported by some climate model simulations, the latter is the most common outcome for the American Southwest in Coupled Model Intercomparison 5 generation models. An aggressive reduction in global greenhouse gas emissions cuts megadrought risks nearly in half.

  15. Relative Impacts of Mitigation, Temperature, and Precipitation on 21st-Century Megadrought Risk in the American Southwest

    Science.gov (United States)

    Ault, Toby R.; Mankin, Justin S.; Cook, Benjamin I.; Smerdon, Jason E.

    2015-01-01

    Megadroughts are comparable in severity to the worst droughts of the 20th century but are of much longer duration. A megadrought in the American Southwest would impose unprecedented stress on the limited water resources of the area, making it critical to evaluate future risks not only under different climate change mitigation scenarios but also for different aspects of regional hydroclimate. We find that changes in the mean hydroclimate state, rather than its variability, determine megadrought risk in the American Southwest. Estimates of megadrought probabilities based on precipitation alone tend to underestimate risk. Furthermore, business-as-usual emissions of greenhouse gases will drive regional warming and drying, regardless of large precipitation uncertainties. We find that regional temperature increases alone push megadrought risk above 70, 90, or 99% by the end of the century, even if precipitation increases moderately, does not change, or decreases, respectively. Although each possibility is supported by some climate model simulations, the latter is the most common outcome for the American Southwest in Coupled Model Intercomparison 5 generation models. An aggressive reduction in global greenhouse gas emissions cuts megadrought risks nearly in half.

  16. Relative impacts of mitigation, temperature, and precipitation on 21st-century megadrought risk in the American Southwest

    Science.gov (United States)

    Ault, Toby R.; Mankin, Justin S.; Cook, Benjamin I.; Smerdon, Jason E.

    2016-01-01

    Megadroughts are comparable in severity to the worst droughts of the 20th century but are of much longer duration. A megadrought in the American Southwest would impose unprecedented stress on the limited water resources of the area, making it critical to evaluate future risks not only under different climate change mitigation scenarios but also for different aspects of regional hydroclimate. We find that changes in the mean hydroclimate state, rather than its variability, determine megadrought risk in the American Southwest. Estimates of megadrought probabilities based on precipitation alone tend to underestimate risk. Furthermore, business-as-usual emissions of greenhouse gases will drive regional warming and drying, regardless of large precipitation uncertainties. We find that regional temperature increases alone push megadrought risk above 70, 90, or 99% by the end of the century, even if precipitation increases moderately, does not change, or decreases, respectively. Although each possibility is supported by some climate model simulations, the latter is the most common outcome for the American Southwest in Coupled Model Intercomparison 5 generation models. An aggressive reduction in global greenhouse gas emissions cuts megadrought risks nearly in half. PMID:27713927

  17. Emerging Technologies for Ecohydrological Studies during the North American Monsoon in a Chihuahuan Desert Watershed

    Science.gov (United States)

    Templeton, R. C.; Vivoni, E. R.; Mendez-Barroso, L. A.; Rango, A.; Laliberte, A.; Saripalli, S.

    2010-12-01

    Monsoonal systems are due to seasonal shifts in atmospheric circulation that may result in a large fraction of the annual precipitation falling within a few months. The North American Monsoon System (NAMS) contributes approximately 55% of the annual rainfall in the New Mexico Chihuahuan Desert during the summer period. Relatively frequent storm events during the NAMS result in increased soil moisture that drive greater soil microbial activity and increased ecosystem primary productivity. During severe storms, runoff production can lead to flood events that recharge the subsurface through channel losses. In this study, we present preliminary results from a network of soil, channel, and atmospheric monitoring equipment in a small watershed (~0.05 km2) located in the Jornada Experimental Range (JER) near Las Cruces, New Mexico. Using the instrument network, we characterize the temporal and spatial variability of rainfall (5 rain gauges), soil moisture and temperature (16 profile locations), and channel runoff (4 flumes) within the watershed during the summer of 2010. In addition, we utilize CO2, H2O, and energy flux measurements by an eddy covariance tower to quantify the seasonal changes in land-atmosphere exchanges. These coordinated, spatially-distributed observations are complemented by the novel use of two Unmanned Aerial Vehicle (UAV) platforms for watershed characterization. Using a small airplane (the MLB BAT 3), we obtained a set of very high-resolution images (~7 cm) and created an orthomosaic to characterize vegetation cover and species prior to the NAMS and after full canopy development. Several instrument packages (optical, stereo and LIDAR) on board a SR30 UAV Electric helicopter also provide detailed information on the watershed, including a high-resolution digital elevation model (DEM). The conjunctive use of these datasets will allow for unprecedented analysis of how the onset and progression of the NAMS affects water, energy and carbon fluxes in a

  18. Atherosclerosis and atherosensitivity in two southwest Algerian desert rodents, Psammomys obesus and Gerbillus gerbillus, and in Rattus norvegicus

    Directory of Open Access Journals (Sweden)

    El-Aoufi S

    2012-09-01

    Full Text Available Salima El-Aoufi,1 Mohamed-Amine Lazourgui,1 Lakhdar Griene,2 Boubekeur Maouche31Laboratoire de Biologie et de Physiologie des Organismes/MMDED, Faculté des Sciences Biologiques, USTHB, El-Alia, Dar El Beida, Algeria; 2Laboratoire d'Hormonologie, Centre Pierre et Marie Curie, C.H.U Mustapha, Algeria; 3Laboratoire de Physicochimie Théorique et Chimie Informatique, Faculté de Chimie, USTHB, El-Alia, Dar El Beida, AlgeriaAbstract: Cardiovascular disease, including atherosclerosis, is the leading cause of death in patients with diabetes worldwide; thus, it is a major medical concern. The endothelium contributes to the control of many vascular functions, and clinical observations show that it is a primary target for diabetic syndrome. To get better insight into the mechanisms underlying atherosclerosis, we studied the interspecific differences in the arterial metabolisms of two, Psammomys obesus and Gerbillus gerbillus, as well as Rattus norvegicus (Wistar rat, well known for its atheroresistance. Twenty-two enzymatic activities and six macromolecular substances were histochemically compared in the two desert species and in Wistar aortas (abdominal and thoracic and arteries (femoral and caudal embedded in a common block. In the healthy adult rodents, enzyme activities were very intense. They demonstrated that aortic myocytes are capable of various synthesis and catabolism processes. However, considering the frequency of atherosclerosis and its phenotypes, significant differences appeared between the species studied. Our comparative study shows that aortic atherosensitive animals have several common metabolic characteristics, which are found in Psammomys rich in metachromatic glycosaminoglycans (involved in the inhibition of lipolysis and in calcification of the organic matrix, reduced activity in enzymes related to the Krebs cycle (weakening energetic power, and low lipolytic enzyme, adenosine triphosphatase, and adenosine diphosphatase activities

  19. Economic performance of irrigation capacity development to adapt to climate in the American Southwest

    Science.gov (United States)

    Ward, Frank A.; Crawford, Terry L.

    2016-09-01

    Growing demands for food security to feed increasing populations worldwide have intensified the search for improved performance of irrigation, the world's largest water user. These challenges are raised in the face of climate variability and from growing environmental demands. Adaptation measures in irrigated agriculture include fallowing land, shifting cropping patterns, increased groundwater pumping, reservoir storage capacity expansion, and increased production of risk-averse crops. Water users in the Gila Basin headwaters of the U.S. Lower Colorado Basin have faced a long history of high water supply fluctuations producing low-valued defensive cropping patterns. To date, little research grade analysis has investigated economically viable measures for irrigation development to adjust to variable climate. This gap has made it hard to inform water resource policy decisions on workable measures to adapt to climate in the world's dry rural areas. This paper's contribution is to illustrate, formulate, develop, and apply a new methodology to examine the economic performance from irrigation capacity improvements in the Gila Basin of the American Southwest. An integrated empirical optimization model using mathematical programming is developed to forecast cropping patterns and farm income under two scenarios (1) status quo without added storage capacity and (2) with added storage capacity in which existing barriers to development of higher valued crops are dissolved. We find that storage capacity development can lead to a higher valued portfolio of irrigation production systems as well as more sustained and higher valued farm livelihoods. Results show that compared to scenario (1), scenario (2) increases regional farm income by 30%, in which some sub regions secure income gains exceeding 900% compared to base levels. Additional storage is most economically productive when institutional and technical constraints facing irrigated agriculture are dissolved. Along with

  20. While on My Journey: A Life Story Analysis of African American Women in Pursuit of Their Doctoral Degrees in the Southwest

    Science.gov (United States)

    Manning, Linda

    2013-01-01

    The purpose of this study is to explore the lived experiences of African American women in pursuit of doctoral degrees in the southwest, their challenges and motivations, and plans for the their next chapter. Drawing from critical race theory and a sociocultural framework, this qualitative study uses Dan McAdams' "Life Story Interview"…

  1. Ploidy race distributions since the Last Glacial Maximum in the North American desert shrub, Larrea tridentata

    Science.gov (United States)

    Hunter, K.L.; Betancourt, J.L.; Riddle, B.R.; Van Devender, T. R.; Cole, K.L.; Geoffrey, Spaulding W.

    2000-01-01

    1 A classic biogeographic pattern is the alignment of diploid, tetraploid and hexaploid races of creosote bush (Larrea tridentata) across the Chihuahuan, Sonoran and Mohave Deserts of western North America. We used statistically robust differences in guard cell size of modern plants and fossil leaves from packrat middens to map current and past distributions of these ploidy races since the Last Glacial Maximum (LGM). 2 Glacial/early Holocene (26-10 14C kyr BP or thousands of radiocarbon years before present) populations included diploids along the lower Rio Grande of west Texas, 650 km removed from sympatric diploids and tetraploids in the lower Colorado River Basin of south-eastern California/south-western Arizona. Diploids migrated slowly from lower Rio Grande refugia with expansion into the northern Chihuahuan Desert sites forestalled until after ???4.0 14C kyr BP. Tetraploids expanded from the lower Colorado River Basin into the northern limits of the Sonoran Desert in central Arizona by 6.4 14C kyr BP. Hexaploids appeared by 8.5 14C kyr BP in the lower Colorado River Basin, reaching their northernmost limits (???37??N) in the Mohave Desert between 5.6 and 3.9 14C kyr BP. 3 Modern diploid isolates may have resulted from both vicariant and dispersal events. In central Baja California and the lower Colorado River Basin, modern diploids probably originated from relict populations near glacial refugia. Founder events in the middle and late Holocene established diploid outposts on isolated limestone outcrops in areas of central and southern Arizona dominated by tetraploid populations. 4 Geographic alignment of the three ploidy races along the modern gradient of increasingly drier and hotter summers is clearly a postglacial phenomenon, but evolution of both higher ploidy races must have happened before the Holocene. The exact timing and mechanism of polyploidy evolution in creosote bush remains a matter of conjecture. ?? 2001 Blackwell Science Ltd.

  2. Tree mortality in mature riparian forest: Implications for Fremont cottonwood conservation in the American southwest

    Science.gov (United States)

    Andersen, Douglas

    2015-01-01

    Mature tree mortality rates are poorly documented in desert riparian woodlands. I monitored deaths and calculated annual survivorship probability (Ps) in 2 groups of large (27–114 cm DBH), old (≥40 years old) Fremont cottonwood (Populus fremontii Wats.) in a stand along the free-flowing Yampa River in semiarid northwestern Colorado. Ps = 0.993 year-1 in a group (n = 126) monitored over 2003–2013, whereas Ps = 0.985 year-1 in a group (n = 179) monitored over the same period plus 3 earlier years (2000–2003) that included drought and a defoliating insect outbreak. Assuming Ps was the same for both groups during the 10-year postdrought period, the data indicate that Ps = 0.958 year-1 during the drought. I found no difference in canopy dieback level between male and female survivors. Mortality was equal among size classes, suggesting Ps is independent of age, but published longevity data imply that either Ps eventually declines with age or, as suggested in this study, periods with high Ps are interrupted by episodes of increased mortality. Stochastic population models featuring episodes of low Ps suggest a potential for an abrupt decline in mature tree numbers where recruitment is low. The modeling results have implications for woodland conservation, especially for relictual stands along regulated desert rivers.

  3. Preserving Southwest Virginia's Folklore.

    Science.gov (United States)

    Burgin, Ramond

    1997-01-01

    Describes Southwest Virginia's rich tradition of folklore and culture and the need for its preservation. Summarizes the author's time-consuming process of preparing an inventory and indexing the vast archival collections gathered by students in American Folklore classes at Mountain Empire Community College and by the Southwest Virginia Folklore…

  4. Exploring Indigenous Identities of Urban American Indian Youth of the Southwest

    Science.gov (United States)

    Kulis, Stephen; Wagaman, M. Alex; Tso, Crescentia; Brown, Eddie F.

    2013-01-01

    This study examined the indigenous identities of urban American Indian youth using measures related to three theoretical dimensions of Markstrom's identity model: identification (tribal and ethnic heritage), connection (reservation ties), and involvement in traditional cultural practices and spirituality. Data came from self-administered…

  5. Seed removal in a tropical North American desert: an evaluation of pre- and post-dispersal seed removal in Stenocereus stellatus.

    Science.gov (United States)

    Álvarez-Espino, R; Ríos-Casanova, L; Godínez-Álvarez, H

    2016-12-31

    To determine seed removal influence on seed populations, we need to quantify pre- and post-dispersal seed removal. Several studies have quantified seed removal in temperate American deserts, but few studies have been performed in tropical deserts. These studies have only quantified pre- or post-dispersal seed removal, thus underestimating the influence of seed removal. We evaluated pre- and post-dispersal seed removal in the columnar cactus Stenocereus stellatus in a Mexican tropical desert. We performed selective exclosure experiments to estimate percentage of seeds removed by ants, birds and rodents during the pre- and post-dispersal phases. We also conducted field samplings to estimate abundance of the most common seed removers. Birds (10-28%) removed a higher percentage of seeds than ants (2%) and rodents (1-4%) during pre-dispersal seed removal. Melanerpes hypopolius was probably the main bird removing seeds from fruits. Ants (62-64%) removed a higher percentage of seeds than birds (34-38%) and rodents (16-30%) during post-dispersal seed removal. Pogonomyrmex barbatus was probably the main ant removing seeds from soil. Birds and ants are the main pre- and post-dispersal seed removers in S. stellatus, respectively. Further studies in other S. stellatus populations and plants with different life forms and fruit types will contribute to evaluate seed removal in tropical American deserts.

  6. A Focused Comparison of Soviet and American National Interests in Southwest Asia

    Science.gov (United States)

    1986-06-01

    and Middle Eastern Studies, VI: 1, (Fall 1982), 58. for Arnold, Bradther, Diip ree , aend Newell I ee a bove. t4 canicellation Of debts, land reform...And for the i mpact of the 01 ympic boq.cott Laurence Barton, "The American 01 ympic Bo’jcott of 1 960: The Amalgam of Di plomac’j and Propaganda i n I... Laurence Barton the OlUmpic bogcott did manage to perhaps dent Soviet prestige and public relations goals. It also gave the United Stoteý5 the

  7. Fluvial Transport Model from Spatial Distribution Analysis of Libyan Desert Glass Mass on the Great Sand Sea (Southwest Egypt: Clues to Primary Glass Distribution

    Directory of Open Access Journals (Sweden)

    Nancy Jimenez-Martinez

    2015-04-01

    Full Text Available Libyan Desert Glass (LDG is a natural silica-rich melted rock found as pieces scattered over the sand and bedrock of the Western Desert of Egypt, northeast of the Gilf Kebir. In this work, a population mixture analysis serves to relate the present spatial distribution of LDG mass density with the Late Oligocene–Early Miocene fluvial dynamics in the Western Desert of Egypt. This was verified from a spatial distribution model that was predicted from the log-normal kriging method using the LDG–mass-dependent transformed variable, Y(x. Both low- and high-density normal populations (–9.2 < Y(x < –3.5 and –3.8 < Y(x < 2.1, respectively were identified. The low-density population was the result of an ordinary fluvial LDG transport/deposition sequence that was active from the time of the melting process, and which lasted until the end of activity of the Gilf River. The surface distribution of the high-density population allowed us to restrict the source area of the melting process. We demonstrate the importance of this geostatistical study in unveiling the probable location of the point where the melting of surficial material occurred and the role of the Gilf River in the configuration of the observed strewn field.

  8. Wood decay in desert riverine environments

    Science.gov (United States)

    Andersen, Douglas; Stricker, Craig A.; Nelson, S. Mark

    2016-01-01

    , local weather, and especially the regional climate through its effect on the flow regime. The increased warmth and aridity expected to accompany climate change in the North American southwest will likely retard the already slow wood decay process on naturally functioning desert river floodplains. Our results have implications for designing environmental flows to manage floodplain forest wood budgets, carbon storage, and nutrient cycling along regulated dryland rivers.

  9. “All My Tears Were Gone”: Suffering and Cancer Pain in Southwest American Indians

    Science.gov (United States)

    Haozous, Emily A; Knobf, M. Tish

    2012-01-01

    Context Although minority patients with cancer pain are more likely to be undermedicated for cancer pain than non-Hispanic Whites, little is known about the experience of cancer pain in American Indians (AIs). Objectives To describe the experience of cancer and cancer pain in a sample of southwestern AIs. Methods Ethnographic interviews were conducted with 13 patients and 11 health care providers, caregivers, and community members; two questionnaires were used to collect demographic and pain data. Results Barriers to pain control among AIs included difficulties describing pain, a belief that cancer pain is inevitable and untreatable, and an aversion to taking opioid pain medication. Prescriber inexperience also was cited as a barrier to pain management. AIs described a strong desire to protect their privacy regarding their illness, and many felt that expressing pain was a sign of weakness. The inability to participate in spiritual and cultural activities caused AIs distress, and some discontinued treatment or missed chemotherapy appointments to engage in these activities. Conclusion Results revealed new knowledge about the cancer pain experience in AIs. The observation of the close relationship between treatment compliance and the patient’s ability to participate in ceremonial and spiritual activities provides new insight into the problem of incomplete cancer treatment in this population. The finding that AI patients have a multidimensional conceptualization of pain will assist clinicians with obtaining more detailed and informative pain assessments. PMID:22940564

  10. Thermochronology in southeast Alaska and southwest Yukon: Implications for North American Plate response to terrane accretion

    Science.gov (United States)

    Enkelmann, Eva; Piestrzeniewicz, Adam; Falkowski, Sarah; Stübner, Konstanze; Ehlers, Todd A.

    2017-01-01

    This study presents the first comprehensive dataset of low-temperature thermochronology from 43 bedrock samples collected north of the active Yakutat-North American plate boundary. Our apatite and zircon (U-Th)/He and fission-track data reveal the cooling history of the inboard Wrangellia Composite Terrane that is dominated by rapid cooling after Late Jurassic to Early Cretaceous arc magmatism followed by very little cooling and exhumation until today. Deformation resulting in rock exhumation due to the collision of the Yakutat microplate is spatially very limited (20-30 km) and is concentrated mainly in the Chugach-Prince William Terrane and rocks near the Border Ranges Fault. Focused exhumation from greater depths of ca. 10 km with very high rates (>5 km/Myr) is localized at the syntaxis region, starting ca. 10 Ma and shifted south through time. The rapid exhumation rates are explained by the development of strong feedbacks between tectonically driven surface uplift and erosion, which started already before glaciation of the area. The shift in the location towards the south is a consequence of continuous readjusting between tectonics and climate, which is changing on local and global scales since the Late Miocene.

  11. Desert wetlands—Archives of a wetter past

    Science.gov (United States)

    Pigati, Jeffery S.; Springer, Kathleen B.; Manker, Craig R.

    2015-12-16

    Scientists from the U.S. Geological Survey (USGS) are finding evidence of a much wetter past in the deserts of the American Southwest using a most unlikely source—wetlands. Wetlands form in arid environments where water tables approach or breach the ground surface. Often thought of as stagnant and unchanging, new evidence suggests that springs and wetlands responded dynamically to past episodes of abrupt climate change. Multiple cycles of deposition, erosion, and soil formation show that wetlands in the southwestern United States expanded and contracted many times during the past 35,000 years or so, before disappearing altogether as the last glacial period came to a close. USGS scientists are now studying the deposits to determine how closely conditions in the desert were tied to regional and global climate patterns in the past, and what it might mean for the fragile ecosystems in light of anticipated climate change in the future.

  12. Farming the Desert: agriculture in the World War II-era Japanese-American relocation centers.

    Science.gov (United States)

    Lillquist, Karl

    2010-01-01

    In 1942 over 110,000 Japanese Americans were evacuated from the West Coast to ten inland, barbed wire-enclosed relocation centers in the name of national security. Agriculture was a key component of the eight arid to semi-arid centers located in the western United States. Each center's agricultural program included produce for human consumption, feed crops, and livestock. Some centers also grew seed, ornamental, and war crops. Evacuees raised and consumed five types of livestock and sixty-one produce varieties, including many traditional foods. Seasonal surpluses were preserved, shipped to other centers, or sold on the open market. Short growing seasons, poor soils, initially undeveloped lands, pests, equipment shortages, and labor issues hampered operations. However, imprisoned evacuee farmers proved that diverse agricultural programs could succeed in the harsh settings primarily because of labor-intensive farming methods, ingenuity, and the large markets provided by the centers. These agricultural programs played major roles in feeding, providing meaningful employment, and preparing evacuees for life outside the centers, and readied lands for post-war "homesteaders."

  13. Turbines and Terrestrial Vertebrates: Variation in Tortoise Survivorship Between a Wind Energy Facility and an Adjacent Undisturbed Wildland Area in the Desert Southwest (USA).

    Science.gov (United States)

    Agha, Mickey; Lovich, Jeffrey E; Ennen, Joshua R; Augustine, Benjamin; Arundel, Terence R; Murphy, Mason O; Meyer-Wilkins, Kathie; Bjurlin, Curtis; Delaney, David; Briggs, Jessica; Austin, Meaghan; Madrak, Sheila V; Price, Steven J

    2015-08-01

    With the recent increase in utility-scale wind energy development, researchers have become increasingly concerned how this activity will affect wildlife and their habitat. To understand the potential impacts of wind energy facilities (WEF) post-construction (i.e., operation and maintenance) on wildlife, we compared differences in activity centers and survivorship of Agassiz's desert tortoises (Gopherus agassizii) inside or near a WEF to neighboring tortoises living near a wilderness area (NWA) and farther from the WEF. We found that the size of tortoise activity centers varied, but not significantly so, between the WEF (6.25 ± 2.13 ha) and adjacent NWA (4.13 ± 1.23 ha). However, apparent survival did differ significantly between the habitat types: over the 18-year study period apparent annual survival estimates were 0.96 ± 0.01 for WEF tortoises and 0.92 ± 0.02 for tortoises in the NWA. High annual survival suggests that operation and maintenance of the WEF has not caused considerable declines in the adult population over the past two decades. Low traffic volume, enhanced resource availability, and decreased predator populations may influence annual survivorship at this WEF. Further research on these proximate mechanisms and population recruitment would be useful for mitigating and managing post-development impacts of utility-scale wind energy on long-lived terrestrial vertebrates.

  14. Turbines and Terrestrial Vertebrates: Variation in Tortoise Survivorship Between a Wind Energy Facility and an Adjacent Undisturbed Wildland Area in the Desert Southwest (USA)

    Science.gov (United States)

    Agha, Mickey; Lovich, Jeffrey E.; Ennen, Joshua R.; Augustine, Benjamin; Arundel, Terence R.; Murphy, Mason O.; Meyer-Wilkins, Kathie; Bjurlin, Curtis; Delaney, David; Briggs, Jessica; Austin, Meaghan; Madrak, Sheila V.; Price, Steven J.

    2015-08-01

    With the recent increase in utility-scale wind energy development, researchers have become increasingly concerned how this activity will affect wildlife and their habitat. To understand the potential impacts of wind energy facilities (WEF) post-construction (i.e., operation and maintenance) on wildlife, we compared differences in activity centers and survivorship of Agassiz's desert tortoises ( Gopherus agassizii) inside or near a WEF to neighboring tortoises living near a wilderness area (NWA) and farther from the WEF. We found that the size of tortoise activity centers varied, but not significantly so, between the WEF (6.25 ± 2.13 ha) and adjacent NWA (4.13 ± 1.23 ha). However, apparent survival did differ significantly between the habitat types: over the 18-year study period apparent annual survival estimates were 0.96 ± 0.01 for WEF tortoises and 0.92 ± 0.02 for tortoises in the NWA. High annual survival suggests that operation and maintenance of the WEF has not caused considerable declines in the adult population over the past two decades. Low traffic volume, enhanced resource availability, and decreased predator populations may influence annual survivorship at this WEF. Further research on these proximate mechanisms and population recruitment would be useful for mitigating and managing post-development impacts of utility-scale wind energy on long-lived terrestrial vertebrates.

  15. Turbines and terrestrial vertebrates: variation in tortoise survivorship between a wind energy facility and an adjacent undisturbed wildland area in the desert southwest (USA)

    Science.gov (United States)

    Agha, Mickey; Lovich, Jeffrey E.; Ennen, Joshua R.; Augustine, Benjamin J.; Arundel, Terry; Murphy, Mason O.; Meyer-Wilkins, Kathie; Bjurlin, Curtis; Delaney, David F.; Briggs, Jessica; Austin, Meaghan; Madrak, Sheila V.; Price, Steven J.

    2015-01-01

    With the recent increase in utility-scale wind energy development, researchers have become increasingly concerned how this activity will affect wildlife and their habitat. To understand the potential impacts of wind energy facilities (WEF) post-construction (i.e., operation and maintenance) on wildlife, we compared differences in activity centers and survivorship of Agassiz's desert tortoises (Gopherus agassizii) inside or near a WEF to neighboring tortoises living near a wilderness area (NWA) and farther from the WEF. We found that the size of tortoise activity centers varied, but not significantly so, between the WEF (6.25 ± 2.13 ha) and adjacent NWA (4.13 ± 1.23 ha). However, apparent survival did differ significantly between the habitat types: over the 18 year study period apparent annual survival estimates were 0.96 ± 0.01 for WEF tortoises and 0.92 ± 0.02 for tortoises in the NWA. High annual survival suggests that operation and maintenance of the WEF has not caused considerable declines in the adult population over the past two decades. Low traffic volume, enhanced resource availability and decreased predator populations may influence annual survivorship at this WEF. Further research on these proximate mechanisms and population recruitment would be useful for mitigating and managing post-development impacts of utility scale wind energy on long-lived terrestrial vertebrates.

  16. Sociocultural barriers to medical care among Mexican Americans in Texas: a summary report of research conducted by the Southwest Medical Sociology Ad Hoc Committee.

    Science.gov (United States)

    Quesada, G M; Heller, P L

    1977-05-01

    This paper summarizes research findings from members of the Southwest Medical Sociology Ad Hoc Committee concerning sociocultural barriers to medical care among Mexican Americans in Texas. Committee members individually, or in two-person groups, studied a number of factors concerning Mexican-American medical care in Texas such as: 1) mortality, morbidity, and other health status indicators; 2) health manpower and educational needs; 3) political factors impeding economical health care; 4) alienation, familism, and their relationship to utilization of the health services; 5) language and communication barriers; and 6) folk medicine. Findings include documentation that structural alienation of Mexican-Americans from mainstream Anglo-American middle-class society is carried over into their relation with utilization of the health care delivery system; that their emphasis on familism works alternatively to encourage and discourage their seeking access to health care; the language differences serve to perpetuate certain cultural differences that are inimical to health care delivery; and that curanderismo can be seen as complementing other types of health care. The report concludes with a number of recommendations for accomplishing cultural integration that will lead to better care for this segment of the health population.

  17. Use of Anecdotal Occurrence Data in Species Distribution Models: An Example Based on the White-Nosed Coati (Nasua narica in the American Southwest

    Directory of Open Access Journals (Sweden)

    James N. Stuart

    2013-04-01

    Full Text Available Species distributions are usually inferred from occurrence records. However, these records are prone to errors in spatial precision and reliability. Although influence of spatial errors has been fairly well studied, there is little information on impacts of poor reliability. Reliability of an occurrence record can be influenced by characteristics of the species, conditions during the observation, and observer’s knowledge. Some studies have advocated use of anecdotal data, while others have advocated more stringent evidentiary standards such as only accepting records verified by physical evidence, at least for rare or elusive species. Our goal was to evaluate the influence of occurrence records with different reliability on species distribution models (SDMs of a unique mammal, the white-nosed coati (Nasua narica in the American Southwest. We compared SDMs developed using maximum entropy analysis of combined bioclimatic and biophysical variables and based on seven subsets of occurrence records that varied in reliability and spatial precision. We found that the predicted distribution of the coati based on datasets that included anecdotal occurrence records were similar to those based on datasets that only included physical evidence. Coati distribution in the American Southwest was predicted to occur in southwestern New Mexico and southeastern Arizona and was defined primarily by evenness of climate and Madrean woodland and chaparral land-cover types. Coati distribution patterns in this region suggest a good model for understanding the biogeographic structure of range margins. We concluded that occurrence datasets that include anecdotal records can be used to infer species distributions, providing such data are used only for easily-identifiable species and based on robust modeling methods such as maximum entropy. Use of a reliability rating system is critical for using anecdotal data.

  18. Ecophysiology of two Sonoran Desert evergreen shrubs during extreme drought

    Science.gov (United States)

    Recent drought across the arid Southwest US may be especially problematic for evergreen desert species that maintain leaves through dry periods. In July, 2002 we compared the ecophysiogical performance of the microphyllous creosotebush (Larrea tridentata) to broadleaved jojoba (Simmondisa chinensis...

  19. Intimate Partner Violence and Alcohol, Drug, and Mental Disorders among American Indian Women from Southwest Tribes in Primary Care

    Science.gov (United States)

    Duran, Bonnie; Oetzel, John; Parker, Tassy; Malcoe, Lorraine Halinka; Lucero, Julie; Jiang, Yizhou

    2009-01-01

    The relationship of intimate partner violence (IPV) with mental disorders was investigated among 234 American Indian/Alaska Native female primary care patients. Results indicated that unadjusted prevalence ratios for severe physical or sexual abuse (relative to no IPV) were significant for anxiety, PTSD, mood, and any mental disorder. Adjusted…

  20. Chronology, sedimentology, and microfauna of groundwater discharge deposits in the central Mojave Desert, Valley Wells, California

    Science.gov (United States)

    Pigati, Jeffrey S.; Miller, David M.; Bright, Jordon E.; Mahan, Shannon; Nekola, Jeffrey C.; Paces, James B.

    2011-01-01

    During the late Pleistocene, emergent groundwater supported persistent and long-lived desert wetlands in many broad valleys and basins in the American Southwest. When active, these systems provided important food and water sources for local fauna, supported hydrophilic and phreatophytic vegetation, and acted as catchments for eolian and alluvial sediments. Desert wetlands are represented in the geologic record by groundwater discharge deposits, which are also called spring or wetland deposits. Groundwater discharge deposits contain information on the timing and magnitude of past changes in water-table levels and, thus, are a source of paleohydrologic and paleoclimatic information. Here, we present the results of an investigation of extensive groundwater discharge deposits in the central Mojave Desert at Valley Wells, California. We used geologic mapping and stratigraphic relations to identify two distinct wetland sequences at Valley Wells, which we dated using radiocarbon, luminescence, and uranium-series techniques. We also analyzed the sediments and microfauna (ostracodes and gastropods) to reconstruct the specific environments in which they formed. Our results suggest that the earliest episode of high water-table conditions at Valley Wells began ca. 60 ka (thousands of calendar yr B.P.), and culminated in peak discharge between ca. 40 and 35 ka. During this time, cold (4–12 °C) emergent groundwater supported extensive wetlands that likely were composed of a wet, sedge-rush-tussock meadow mixed with mesic riparian forest. After ca. 35 ka, the water table dropped below the ground surface but was still shallow enough to support dense stands of phreatophytes through the Last Glacial Maximum (LGM). The water table dropped further after the LGM, and xeric conditions prevailed until modest wetlands returned briefly during the Younger Dryas cold event (13.0–11.6 ka). We did not observe any evidence of wet conditions during the Holocene at Valley Wells. The timing

  1. Man Corn: Cannibalism and Violence in the Prehistoric American Southwest. Christy G. Turner and Jacqueline A. Turner. University of Utah Press, Salt Lake City, 1999

    Directory of Open Access Journals (Sweden)

    Charles C. Kolb

    1999-11-01

    Full Text Available Human sacrifice and cannibalism, the potential for institutionalized violence or warfare, witchcraft or sorcery, and ritual executions are emotionally charged issues; but some anthropologists and other learned scholars now suggest that these activities and behaviors occurred in the American Southwest, a region usually depicted for peace, harmony, tranquility, and spirituality. Christy Turner, Regents' Professor in the Department of Anthropology at Arizona State University, and his late wife, Jacqueline (1934-1996, are the co-authors of Man Corn. The book's title derives from the Nahuatl word tlacatlaolli, a "sacred meal of sacrificed human meat, cooked with corn." The Nahuatl and Mesoamerican connections are more than coincidental. The idea for this volume was conceived in 1958, and Christy dedicates the volume to the memory of his wife. They comment (p. 8 that "re­search on cannibalism has not been free of controversy or political and professional censuring" and they cite instances where their work has been disbelieved, dismissed, or admonished.

  2. Preventing desert locust plagues: optimizing management interventions

    NARCIS (Netherlands)

    Huis, van A.; Cressman, K.; Magor, J.I.

    2007-01-01

    Solitarious desert locusts, Schistocerca gregaria (Forskål) (Orthoptera: Acrididae), inhabit the central, arid, and semi-arid parts of the species¿ invasion area in Africa, the Middle East, and South-West Asia. Their annual migration circuit takes them downwind to breed sequentially where winter, sp

  3. Desert Scrublands

    Science.gov (United States)

    Jones, L.L.C.; Halama, K.J.; Lovich, R.E.

    2016-01-01

    Desert scrublands comprise the lower to mid-elevation portions of four different ecosystems including the Chihuahuan, Great Basin, Mojave and Sonoran Deserts. Together the area inside their outer boundaries includes over 8% of the surface area of the United States. Despite significant differences in the flora and fauna of these bioregions they all share the common trait of being arid shrub-steppe ecosystems, receiving, on average, less than 254 mm of rain per year. The austere nature of these landscapes belies their significant biodiversity, the amazing behavioral and physiological adaptations of the biota, and the fragility of the ecosystems to human disturbances. For example, the Mojave Desert alone has at least 250 species of ephemeral plants, mostly winter annuals, and up to 90% are endemic.

  4. Desert and desertification in Iran

    Science.gov (United States)

    Bahrami, M.

    2009-04-01

    One of the greatest environmental concerns in Iran as in other arid and semiarid countries is the transformation of once productive, or marginally productive, land to deteriorated land and soil unable to support plants and animals. Because the land becomes barren and dry, the process is described as desertification, which occurs as a sequence of events. The area of deserts in Iran is about 340,000 Km2 (less than one fifth of its total area), of which 100,000 Km2 is being used for some cultivation, 120,000 Km2 is subjected to moving sands about 40 % of which is active sand dunes. Most of features and processes usual in world famous deserts are also observed in Iran: low precipitation, high evaporation, poor or lack of vegetation, saline and alkaline soils, low population and small and sparse oases. The deserts of Iran are generally classified in the subtropical, warm, arid and semiarid group, but the effect and presence of some geographical and geoclimatical factors such as height, vicinity to Indian Ocean and so on do some changes in climatic conditions and geographical features causing some local and regional differences in them. Geographically, two groups of deserts have been known in Iran: (1) Coastal deserts which, like a ribbon with variable width, stretch from extreme southeast to extreme southwest, at the north parts of Oman Sea and Persian Gulf. One important feature of these deserts is relatively high humidity which differentiates them from other deserts. This causes an increase in vegetation coverage and hence a decrease in eolian erosion and also a dominance of chemical weathering to that of physical. (2) internal deserts, which rest in central, eastern and southeastern plateau of the country and in independent and semi dependent depressions. This situation, which is due to the surrounding high mountains, blocks humidity entry and causes the aridity of these deserts. Wind as a dominant process in the area causes deflated features such as Reg (desert

  5. Genetic diversity in Chihuahuan Desert populations of creosotebush (Zygophyllaceae: Larrea tridentata).

    Science.gov (United States)

    Duran, Kristy L; Lowrey, Timothy K; Parmenter, Robert R; Lewis, Paul O

    2005-04-01

    We examined isozyme variation in the dominant Chihuahuan Desert shrub, Larrea tridentata (creosotebush), to determine the genetic variation within and among populations, the biogeographic relationships of populations, and the potential inbreeding in the species. We surveyed 17 populations consisting of 20 to 50 individuals per population along a 1600-km north-south transect across the Chihuahuan Desert. The southernmost population was near Villa Hidalgo, Mexico, and the northernmost near Isleta Pueblo, New Mexico. All 12 isozyme loci examined were polymorphic (H(t) = 0.416), with up to nine alleles per locus. Despite high levels of variation, we detected moderate inbreeding in L. tridentata populations. Most variation was found within rather than among populations (G(ST) = 0.118). Furthermore, recently established populations in the northern limits of the Chihuahuan Desert did not show decreased levels of genetic variation (H(o) = 0.336). A significant correlation was found between pairwise genetic and geographic distances (r = 0.305). Larrea tridentata showed and continues to show a massive range expansion into the arid and semi-arid regions of the American Southwest, but as shown by the high genetic variation, this expansion took place as a wave, rather than a series of founder events.

  6. Detectable Aspects Of Alaska, and the Southwests Kokopelli, Indicate That Environmental Monitoring By Native Americans Utilized Several Sensory Modes, and That Their Conservation Held Moral Value Within Their Traditional Culture.

    Science.gov (United States)

    Ochs, Michael Ann; Mc Leod, Roger D.

    2004-03-01

    Place-names of Alaska and the Americas, in names like Natick, MA, Matagamon, ME, Matacumbe Key, FL, Tecate Mt, CA, and Tacoma, WA as well as Allapatah, FL, and Issaqua, WA indicate Native Americans all monitored equivalent aspects of the earths EMF. Former coastal and island areas of Native American activity and culture in Alaska show a traditional, historic leader climbed the mountain of one cliff-like island area for weather prediction. We suggest that the ascent onto the mountain and the subsequent significant stay there was for purposes of cultural and religious reverence associated with direct observation of phenomena associated with known weather sequences. Similar cultural awareness of EMF phenomena and weather-making could be related to practices of the MiKmaw/Micmac Indians of the northeast, and the so-called rain-dance of the Hopi of the southwest. *This paper does not necessarily represent the views of the U.S. E.P.A

  7. ¡Salud! Southwest Tour

    Directory of Open Access Journals (Sweden)

    Joanna Mae Mae Souers

    2009-06-01

    Full Text Available During this summer of 2009, 12 American medical students from the Escuela Latinoamericana de Medicina (ELAM – Latin American School of Medicine in Havana, Cuba will board a Recreational Vehicle (RV to travel across the Southwest region of the United States visiting a number of tribal settlements of American Indian Nations, community colleges and universities. While at the various sites the students will share their personal experiences of what it’s like to study at ELAM while promoting the availability of full scholarships for students, volunteer their services while learning about some of the more significant health concerns affecting American Indian populations and to build personal and professional relationships with health care practitioners and members of Native American communities.

  8. Desert Shield and Desert Storm Emerging Observations

    Science.gov (United States)

    1991-10-07

    by identifying activo component an civilian maintenance instructors to replace active component instructors receiving orders for war or other PCS sites...STORM Desert scenarios in UCOFT 81619 /61WY (00687) DESERT STORM Activo Tank Table 911 816sy 90990 (006m) DESERT STloM Degraded Mode Guoery WS1W 4042iA

  9. Desert Operations Tactics, Techniques, and Procedures. Southwest Asia Focus

    Science.gov (United States)

    1990-11-01

    identify and/or kill the snake. Take it to medical personnel for inspection / identification. TREAT ALL SNAKEBITES AS POISONOUS . The treatment prescribed...Reconnaissance .......................................................................... 5-1 BATTLEFIELD AREA OF EVALUATION ...weather, and may be seen coiled in shady spots during the day. DON’T PLAY WITH SNAKES! PIT POISON SAC FANGS EYE EYE Viper Cobra 1-3 ChapterI - The Area

  10. Mapping habitat for multiple species in the Desert Southwest

    Science.gov (United States)

    Inman, Richard D.; Nussear, Kenneth E.; Esque, Todd C.; Vandergast, Amy G.; Hathaway, Stacie A.; Wood, Dustin A.; Barr, Kelly R.; Fisher, Robert N.

    2014-01-01

    Many utility scale renewable energy projects are currently proposed across the Mojave Ecoregion. Agencies that manage biological resources throughout this region need to understand the potential impacts of these renewable energy projects and their associated infrastructure (for example, transmission corridors, substations, access roads, etc.) on species movement, genetic exchange among populations, and species’ abilities to adapt to changing environmental conditions. Understanding these factors will help managers’ select appropriate project sites and possibly mitigate for anticipated effects of management activities. We used species distribution models to map habitat for 15 species across the Mojave Ecoregion to aid regional land-use management planning. Models were developed using a common 1 × 1 kilometer resolution with maximum entropy and generalized additive models. Occurrence data were compiled from multiple sources, including VertNet (http://vertnet.org/), HerpNET (http://www.herpnet.org), and MaNIS (http://manisnet.org), as well as from internal U.S. Geological Survey databases and other biologists. Background data included 20 environmental covariates representing terrain, vegetation, and climate covariates. This report summarizes these environmental covariates and species distribution models used to predict habitat for the 15 species across the Mojave Ecoregion.

  11. ABCC8 R1420H Loss-of-Function Variant in a Southwest American Indian Community: Association With Increased Birth Weight and Doubled Risk of Type 2 Diabetes.

    Science.gov (United States)

    Baier, Leslie J; Muller, Yunhua Li; Remedi, Maria Sara; Traurig, Michael; Piaggi, Paolo; Wiessner, Gregory; Huang, Ke; Stacy, Alyssa; Kobes, Sayuko; Krakoff, Jonathan; Bennett, Peter H; Nelson, Robert G; Knowler, William C; Hanson, Robert L; Nichols, Colin G; Bogardus, Clifton

    2015-12-01

    Missense variants in KCNJ11 and ABCC8, which encode the KIR6.2 and SUR1 subunits of the β-cell KATP channel, have previously been implicated in type 2 diabetes, neonatal diabetes, and hyperinsulinemic hypoglycemia of infancy (HHI). To determine whether variation in these genes affects risk for type 2 diabetes or increased birth weight as a consequence of fetal hyperinsulinemia in Pima Indians, missense and common noncoding variants were analyzed in individuals living in the Gila River Indian Community. A R1420H variant in SUR1 (ABCC8) was identified in 3.3% of the population (N = 7,710). R1420H carriers had higher mean birth weights and a twofold increased risk for type 2 diabetes with a 7-year earlier onset age despite being leaner than noncarriers. One individual homozygous for R1420H was identified; retrospective review of his medical records was consistent with HHI and a diagnosis of diabetes at age 3.5 years. In vitro studies showed that the R1420H substitution decreases KATP channel activity. Identification of this loss-of-function variant in ABCC8 with a carrier frequency of 3.3% affects clinical care as homozygous inheritance and potential HHI will occur in 1/3,600 births in this American Indian population.

  12. Wind modeling of Chihuahuan Desert dust outbreaks

    Science.gov (United States)

    Rivera Rivera, Nancy I.; Gill, Thomas E.; Gebhart, Kristi A.; Hand, Jennifer L.; Bleiweiss, Max P.; Fitzgerald, Rosa M.

    The Chihuahuan Desert region of North America is a significant source of mineral aerosols in the Western Hemisphere, and Chihuahuan Desert dust storms frequently impact the Paso del Norte (El Paso, USA/Ciudad Juarez, Mexico) metropolitan area. A statistical analysis of HYSPLIT back trajectory residence times evaluated airflow into El Paso on all days and on days with synoptic (non-convective) dust events in 2001-2005. The incremental probability—a measure of the areas most likely to have been traversed by air masses arriving at El Paso during dusty days—was only strongly positively associated with the region west-southwest of the city, a zone of known dust source areas. Focused case studies were made of major dust events on 15 April and 15 December 2003. Trajectories approached the surface and MM5 (NCAR/Penn State Mesoscale Model) wind speeds increased at locations consistent with dust sources observed in satellite imagery on those dates. Back trajectory and model analyses suggested that surface cyclones adjacent to the Chihuahuan Desert were associated with the extreme dust events, consistent with previous studies of dust storms in the Southern High Plains to the northeast. The recognition of these meteorological patterns serves as a forecast aid for prediction of dust events likely to impact the Paso del Norte.

  13. Sonoran Desert: Fragile Land of Extremes

    Science.gov (United States)

    Produced and Directed by Wessells, Stephen

    2003-01-01

    'Sonoran Desert: Fragile Land of Extremes' shows how biologists with the U.S. Geological Survey work with other scientists in an effort to better understand native plants and animals such as desert tortoises, saguaro cacti, and Gila monsters. Much of the program was shot in and around Saguaro National Park near Tucson, Arizona. Genetic detective work, using DNA, focuses on understanding the lives of tortoises. Studies of saguaros over many decades clarify how these amazing plants reproduce and thrive in the desert. Threats from fire, diseases in tortoises, and a growing human population motivate the scientists. Their work to identify how these organisms live and survive is a crucial step for the sound management of biological resources on public lands. This 28-minute program, USGS Open-File Report 03-305, was shot entirely in high definition video and produced by the USGS Western Ecological Research Center and Southwest Biological Science Center; produced and directed by Stephen Wessells, Western Region Office of Communications.

  14. The effect of drought on four plant communities in the northern Mojave Desert

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, B.W. [Desert Research Inst., Reno, NV (United States); Ostler, W.K. [EG and G Energy Measurements, Inc., Las Vegas, NV (United States)

    1993-12-31

    Desert plant communities contain many perennial plant species that are well adapted to arid environments; therefore, one would intuitively believe that perennial desert species readily survive drought conditions. Abundant research on plant-soil-water relationships in North American deserts has shown that many species can maintain water uptake and growth when the soil-water potential is low. Little research, however, has focused on how prolonged drought conditions affect plant species in vegetation associations in desert ecosystems. A prolonged and widespread drought occurred in much of the western United States, including the Northern Mojave Desert, from 1987 through 1991. During this drought period vegetation characterization studies, initiated in 1990, by the US Department of Energy (DOE) at Yucca Mountain, Nevada, allowed EG and G Energy Measurements to collect data that could be used to infer how both desert vegetation associations and desert plant species reacted to a prolonged drought. This paper presents the preliminary results.

  15. South and Southwest HSRC

    Data.gov (United States)

    Federal Laboratory Consortium — The Hazardous Substance Research Center/South and Southwest is a competitively awarded, peer-reviewed research consortium led by Louisiana State University with the...

  16. Sensors for Desert Surveillance

    Directory of Open Access Journals (Sweden)

    B. S. Chauhan

    2005-10-01

    Full Text Available Various types of sensors-visible, passive night vision, infrared, synthetic aperture radar, etc can be used for desert surveillance. The surveillance capability of these sensors depends to a large extent, on various atmospheric effects, viz., absorption, scattering, aerosol, turbulence, and optical mirage. In this paper, effects of various atmospheric phenomena on the transmission of signals, merits and demerits of different means of surveillance under desert environmental conditions are discussed. Advanced surveillance techniques, ie, multisensor fusion, multi and hyperspectral imaging, having special significance for desert surveillance, have also been discussed.

  17. Nelson's big horn sheep (Ovis canadensis nelsoni) trample Agassiz's desert tortoise (Gopherus agassizii) burrow at a California wind energy facility

    Science.gov (United States)

    Agha, Mickey; Delaney, David F.; Lovich, Jeffrey E.; Briggs, Jessica; Austin, Meaghan; Price, Steven J.

    2015-01-01

    Research on interactions between Agassiz's desert tortoises (Gopherus agassizii) and ungulates has focused exclusively on the effects of livestock grazing on tortoises and their habitat (Oldemeyer, 1994). For example, during a 1980 study in San Bernardino County, California, 164 desert tortoise burrows were assessed for vulnerability to trampling by domestic sheep (Ovis aries). Herds of grazing sheep damaged 10% and destroyed 4% of the burrows (Nicholson and Humphreys 1981). In addition, a juvenile desert tortoise was trapped and an adult male was blocked from entering a burrow due to trampling by domestic sheep. Another study found that domestic cattle (Bos taurus) trampled active desert tortoise burrows and vegetation surrounding burrows (Avery and Neibergs 1997). Trampling also has negative impacts on diversity of vegetation and intershrub soil crusts in the desert southwest (Webb and Stielstra 1979). Trampling of important food plants and overgrazing has the potential to create competition between desert tortoises and domestic livestock (Berry 1978; Coombs 1979; Webb and Stielstra 1979).

  18. Reclaiming freshwater sustainability in the Cadillac Desert

    Science.gov (United States)

    Sabo, John L.; Sinha, Tushar; Bowling, Laura C.; Schoups, Gerrit H.W.; Wallender, Wesley W.; Campana, Michael E.; Cherkauer, Keith A.; Fuller, Pam L.; Graf, William L.; Hopmans, Jan W.; Kominoski, John S.; Taylor, Carissa; Trimble, Stanley W.; Webb, Robert H.; Wohl, Ellen E.

    2010-01-01

    Increasing human appropriation of freshwater resources presents a tangible limit to the sustainability of cities, agriculture, and ecosystems in the western United States. Marc Reisner tackles this theme in his 1986 classic Cadillac Desert: The American West and Its Disappearing Water. Reisner's analysis paints a portrait of region-wide hydrologic dysfunction in the western United States, suggesting that the storage capacity of reservoirs will be impaired by sediment infilling, croplands will be rendered infertile by salt, and water scarcity will pit growing desert cities against agribusiness in the face of dwindling water resources. Here we evaluate these claims using the best available data and scientific tools. Our analysis provides strong scientific support for many of Reisner's claims, except the notion that reservoir storage is imminently threatened by sediment. More broadly, we estimate that the equivalent of nearly 76% of streamflow in the Cadillac Desert region is currently appropriated by humans, and this figure could rise to nearly 86% under a doubling of the region's population. Thus, Reisner's incisive journalism led him to the same conclusions as those rendered by copious data, modern scientific tools, and the application of a more genuine scientific method. We close with a prospectus for reclaiming freshwater sustainability in the Cadillac Desert, including a suite of recommendations for reducing region-wide human appropriation of streamflow to a target level of 60%.

  19. Journeying the Redshift Desert

    CERN Document Server

    Renzini, Alvio

    2009-01-01

    The cosmic star formation rate, AGN activity, galaxy growth, mass assembly and morphological differentiation all culminate at redshift $\\sim 2$. Yet, the redshift interval $1.4\\lsim z\\lsim 3$ is harder to explore than the closer and the more distant Universe. In spite of so much action taking place in this spacetime portion of the Universe, it has been dubbed the ``Redshift Desert'', as if very little was happening within its boundaries. The difficulties encountered in properly mapping the galaxy populations inhabiting the Desert are illustrated in this paper, along with some possible remedy.

  20. Indian-Spanish Communication Networks: Continuity in the Greater Southwest.

    Science.gov (United States)

    Riley, Carroll L.; Manson, Joni L.

    Trade and communication networks established by Indian groups in the 15th century A.D. linked the Southwest to Mesoamerica, the Plains and the Pacific littoral; these routes were later used by the Spanish and Americans, and today major highways follow ancient Indian routes. The main east-west route had major termini at Cibola (near Zuni) in the…

  1. Southwestern desert resources

    Science.gov (United States)

    Halvorson, William L.; van Riper, Charles; Schwalbe, Cecil R.

    2010-01-01

    The southwestern deserts stretch from southeastern California to west Texas and then south to central Mexico. The landscape of this region is known as basin and range topography featuring to "sky islands" of forest rising from the desert lowlands which creates a uniquely diverse ecology. The region is further complicated by an international border, where governments have caused difficulties for many animal populations. This book puts a spotlight on individual research projects which are specific examples of work being done in the area and when they are all brought together, to shed a general light of understanding the biological and cultural resources of this vast region so that those same resources can be managed as effectively and efficiently as possible. The intent is to show that collaborative efforts among federal, state agency, university, and private sector researchers working with land managers, provides better science and better management than when scientists and land managers work independently.

  2. Aquaporins in desert rodent physiology.

    Science.gov (United States)

    Pannabecker, Thomas L

    2015-08-01

    Desert rodents face a sizeable challenge in maintaining salt and water homeostasis due to their life in an arid environment. A number of their organ systems exhibit functional characteristics that limit water loss above that which occurs in non-desert species under similar conditions. These systems include renal, pulmonary, gastrointestinal, nasal, and skin epithelia. The desert rodent kidney preserves body water by producing a highly concentrated urine that reaches a maximum osmolality nearly three times that of the common laboratory rat. The precise mechanism by which urine is concentrated in any mammal is unknown. Insights into the process may be more apparent in species that produce highly concentrated urine. Aquaporin water channels play a fundamental role in water transport in several desert rodent organ systems. The role of aquaporins in facilitating highly effective water preservation in desert rodents is only beginning to be explored. The organ systems of desert rodents and their associated AQPs are described.

  3. Physiological adaptation in desert birds

    NARCIS (Netherlands)

    Williams, JB; Tieleman, BI; Williams, Joseph B.

    2005-01-01

    We call into question the idea that birds have not evolved unique physiological adaptations to desert environments. The rate at which desert larks metabolize energy is lower than in mesic species within the same family, and this lower rate of living translates into a lower overall energy requirement

  4. CHARACTERISTICS OF AMERICAN ENGLISH

    Institute of Scientific and Technical Information of China (English)

    韦娟; 黄舜

    2007-01-01

    The large scale colonization of America by British settlers took place in the seventeenth century.During the process,the immigrants brought English to America.They desert great influence to the development of American English.After the civil war,American got political independence,and then there arose a tendency to develop an American brand of English.Famous persons like Thomas Jeffe,Benjamin,Franklin,and Noah Webster began to consider that the country should have a language of its own.

  5. Design and fabrication of a prototype system for photovoltaic residences in the Southwest

    Science.gov (United States)

    1982-06-01

    Described are the design of a photovoltaic powered residence for the American Southwest, dubbed Casa fotovoltaica, and the construction of a prototype building at the Southwest Residential Experiment Station for testing the performance of the full size photovoltaic (PV) system. Included are architectural drawings of both the residence and the prototype, analysis of the energy requirements of the residence, prediction of PV system output, description of the electrical system, and history of the construction process of the prototype.

  6. April 2016 Pacific Southwest Newsletter

    Science.gov (United States)

    EPA Pacific Southwest Newsletter for April 2016: University of Arizona Reduces Food Waste, Cleaning Up Underground Fuel Tanks in Fresno, The Argonaut Mine, Ensuring Clean Water in Nevada,Cleaning Up Groundwater in Whittier, California, and more!

  7. Ecological zones of California deserts

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The dataset delineates ecological zones within California deserts. We derived ecological zones by reclassifying LANDFIRE vegetation biophysical setting types, plus...

  8. Vegetation Structure and Function along Ephemeral Streams in the Sonoran Desert

    Science.gov (United States)

    Stromberg, J. C.; Katz, G.

    2011-12-01

    Despite being the most prevalent stream type in the American Southwest, far less is known about riparian ecosystems associated with ephemeral streams than with perennial streams. Patterns of plant composition and structure reflect complex environmental gradients, including water availability and flood intensity, which in turn are related to position in the stream network. A survey of washes in the Sonoran Desert near Tucson, Arizona showed species composition of small ephemeral washes to be comprised largely of upland species, including large seeded shrubs such as Acacia spp. and Larrea tridentata. Small seeded disturbance adapted xerophytic shrubs, such as Baccharis sarothroides, Hymenoclea monogyra and Isocoma tenuisecta, were common lower in the stream network on the larger streams that have greater scouring forces. Because ephemeral streams have multiple water sources, including deep (sometimes perched) water tables and seasonally variable rain and flood pulses, multiple plant functional types co-exist within a stream segment. Deep-rooted phreatophytes, including Tamarix and nitrogen-fixing Prosopis, are common on many washes. Such plants are able to access not only water, but also pools of nutrients, several meters below ground thereby affecting nutrient levels and soil moisture content in various soil strata. In addition to the perennial plants, many opportunistic and shallow-rooted annual species establish during the bimodal wet seasons. Collectively, wash vegetation serves to stabilize channel substrates and promote accumulation of fine sediments and organic matter. In addition to the many streams that are ephemeral over their length, ephemeral reaches also occupy extensive sections of interrupted perennial rivers. The differences in hydrologic conditions that occur over the length of interrupted perennial rivers influence plant species diversity and variability through time. In one study of three interrupted perennial rivers, patterns of herbaceous species

  9. Remote Sensing Field Guide - Desert

    Science.gov (United States)

    1991-09-01

    sea in North America is in the Gran Desierto of northern Sonora, Mexico, which extends northward into the Yuma Desert of Arizona and the Algodones...parallel to the dune chains. PATTERN INDICATOR SHEET - DESERT DUNES PHOTO: AERIAL (OBLIQUE) STAR - COMPOUND LOCATION: Mexico (Northern) El Gran Desierto ...dunes. This field is in the central part of El Gran Desierto about 20 km south of the Arizona-Mexico border Photo B (on back) is a closer view. For orien

  10. Thermodynamic and pedogenic differences between desert microsites

    Science.gov (United States)

    Young, Michael; Caldwell, Todd; Lin, Henry

    2014-05-01

    taken along transects radiating from canopies of perennial shrubs into bare interspaces of structured soils. We augmented these measurements with ground-penetrating radar (GPR), laboratory analyses, and (in some cases) soil trenches. The results showed higher saturated conductivity under canopies versus interspaces, regardless of surface age, with the largest differences observed on older, developed soils. Bulk density, soil structure grade, and silt and clay content increased significantly away from the canopy, and organic content decreased toward interspaces. Trends in soil properties, from canopies to interspaces, were found to be predictable to a distance of 1.35 +/- 0.32 times the canopy radius, regardless of the size or genus of the shrub. The microsite environments, which are separated by only 10s of cm, release energy and mass at different rates—the fluxes differ by microsite locations. They exist with different thermodynamic gradients, with larger upward fluxes to support shrubs under canopy microsites and larger downward fluxes in interspaces. Armoured against change in interspaces can explain progressive structural evolution of pedons, a paradoxically reduced water infiltration capacity, and a contraction of canopy volumes and ecosystem production in older soils. We use these gradients to illustrate the importance of microsite location when considering complex feedbacks that result through currently-observed, time-dependent processes of pedogenesis in arid regions of the desert southwest.

  11. Variations in ADH and ALDH in Southwest California Indians

    Science.gov (United States)

    Ehlers, Cindy L.

    2007-01-01

    Native Americans as a group have the highest rates of alcohol-related deaths of all ethnicities in the United States; however, it remains unclear how and why a greater proportion of individuals in some Native American communities develop alcohol-related problems and alcohol use disorders (AUDs). One potential factor that can influence responses to alcohol are variations in alcohol-metabolizing enzymes. Researchers have analyzed the frequencies of variants in the alcohol-metabolizing enzymes alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) in some Native American populations. So far the studies have yielded no evidence that an ALDH2 variant, which has shown protective effects in other populations, is found in either American Indians or Alaska Natives. A variant of the ALDH1 enzyme that is encoded by the ALDH1A1*2 allele, however, was found in a small proportion of a group of Southwest California Indians and had a protective effect against alcoholism in that population. Furthermore, a variant of the ADH1B enzyme that is encoded by the ADH1B*3 allele was found in a similar proportion of Southwest California Indians and also was associated with a protective effect. However, these findings do not explain the high prevalence of alcoholism in the tribes investigated. PMID:17718395

  12. Southwest Airlines: lessons in loyalty.

    Science.gov (United States)

    D'Aurizio, Patricia

    2008-01-01

    Southwest Airlines continues to garner accolades in the areas of customer service, workforce management, and profitability. Since both the health care and airlines industries deal with a service rather than a product, the customer experience depends on the people who deliver that experience. Employees' commitment or "loyalty" to their customers, their employer, and their work translates into millions of dollars of revenue. What employee wants to work for "the worst employer in town?" Nine loyalty lessons from Southwest can be carried over to the health care setting for the benefit of employees and patients.

  13. Recommended Cross-Desert Driving Route

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Beijing - Duolun - Dalai Nur- Hexigten Banner -Saihanba - Weichang - Luanping - Miyun - Beijing. Along this 1,600-kilometer route is a 150-kin section(between Duolun and Darhan) of desert with no surfaced road - a paradise for desert drivers.

  14. Stone structures in the Syrian Desert

    CERN Document Server

    Sparavigna, Amelia Carolina

    2011-01-01

    An arid land, known as the Syrian Desert, is covering a large part of the Middle East. In the past, this harsh environment, characterized by huge lava fields, the "harraat", was considered as a barrier between Levant and Mesopotamia. When we observe this desert from space, we discover that it is crossed by some stone structures, the "desert kites", which were the Neolithic traps for the game. Several stone circles are visible too, as many Stonehenge sites dispersed in the desert landscape.

  15. Phytoremediation for Oily Desert Soils

    Science.gov (United States)

    Radwan, Samir

    This chapter deals with strategies for cleaning oily desert soils through rhizosphere technology. Bioremediation involves two major approaches; seeding with suitable microorganisms and fertilization with microbial growth enhancing materials. Raising suitable crops in oil-polluted desert soils fulfills both objectives. The rhizosphere of many legume and non-legume plants is richer in oil-utilizing micro-organisms than non-vegetated soils. Furthermore, these rhizospheres also harbour symbiotic and asymbiotic nitrogen-fixing bacteria, and are rich in simple organic compounds exuded by plant roots. Those exudates are excellent nutrients for oil-utilizing microorganisms. Since many rhizospheric bacteria have the combined activities of hydrocarbon-utilization and nitrogen fixation, phytoremediation provides a feasible and environmentally friendly biotechnology for cleaning oil-polluted soils, especially nitrogen-poor desert soils.

  16. Hydrological responses of the Chihuahua Desert of Mexico to possible Heinrich Stadials

    Science.gov (United States)

    Quiroz-Jimenez, Jesús David; Roy, Priyadarsi D.; Lozano-Santacruz, Rufino; Giron-García, Patricia

    2017-01-01

    Hydrological response of the Chihuahua Desert of Mexico to six different Heinrich Stadials (H6 to H1) is inferred with element ratio, carbonate abundance, and oxygen and carbon isotope compositions of lacustrine calcite in sediments collected from the Santiaguillo Basin. Overall runoff and hence precipitation remained below average during H6, H4, H2 and H1, and above average during H5 and H3. Similarly, runoff of H4 showed the least variability and it was most variable during H5. In general, dissolved HCO3- was dominantly sourced from atmospheric CO2 during the intervals of less runoff. However, lacustrine productivity as well as atmospheric CO2 influenced carbon isotope composition of dissolved HCO3- during the regimes of fluctuating hydrological conditions. H2 was an interval of relatively warmer water column and enhanced lacustrine productivity. Comparison with other records indicates occurrence of similar millennial-scale hydrological variability in the southwest US. However, we did not always observe concurrency in proxy records from the Chihuahua Desert of Mexico and southwest US. Similarity in tendencies of runoff into the Santiaguillo Basin and δ18O of speleothem from the Hulu Cave during the six different Heinrich Stadials suggests a possible hemispheric link between hydroclimate of the Chihuahua Desert of Mexico and the East Asian Monsoon.

  17. Cultural Arts in the Southwest.

    Science.gov (United States)

    Cross, Kate

    1998-01-01

    Presents a pottery project for eighth-grade students based on a study of ancient and modern forms of Pueblo Indian pottery of the Southwest United States. Details the process for creating either carved, red clay, or painted white clay pottery typical of these cultural groups. Relates student reactions to the project. (DSK)

  18. Snails, stable iostopes, and southwestern desert paleoclimates

    Energy Technology Data Exchange (ETDEWEB)

    Sharpe, S.E. [Univ. and Community College System of Nevada, Reno, NV (United States); Whelan, J.F.; Forester, R.M.; Burdett, J.

    1995-09-01

    Modern and fossil molluscs (snails) occur in many localities in and semi-arid regions throughout the desert southwest. Live terrestrial snails are found under rocks and in forest litter and aquatic taxa inhabit springs, seeps, and/or wetlands. Molluscs uptake local water during their growing season (spring and summer) and incorporate its delta 180 signature into their shells. Preliminary 180 analysis of modem shells from the southern Great Basin indicates that the shells probably reflect meteoric water 180 values during the growing season. This provides a way to estimate the delta 180 value of precipitation and, thereby, the source of the moisture-bearing air masses. Significant 180 variability in shells analyzed include geographic location, elevation, taxonomy, and habitat (terrestrial, spring, or wetland). We found a rough inverse correlation with elevation in modem shells from the Spring Range in southern Nevada. The delta 180 values of modem and fossil shells are also very different; modem values in this location are much higher than those from nearby late Pleistocene-age molluscs suggesting that the Pleistocene summers were variously colder and wetter than today or less evaporative (more humid). Assuming shell material directly reflects the 180 of the growing-season environment, comparison of modem and fossil shell delta 180 values can potentially identify changes in air-mass moisture sources and can help to define seasonal precipitation change through time. Comprehension and quantification of community and isotopic variability in modem gastropods is required to create probabilistic valid transfer functions with fossil materials. Valid inferences about past environmental conditions can then be established with known confidence limits.

  19. Desert Environmental Handbook. First Edition

    Science.gov (United States)

    1977-11-01

    Department of the Army, February 1972. 2. Analogs of Yuma Climate I-XI, US Army Natick Laboratories, Natick, Massachusetts, 1958-60. 3. Kolb, C. R.; Dornbusch ...Station Atrea, Arizona, Purdue University, March 1955. Kolb, C. R.; Dornbusch , W. K. Jr.; 1. Analogs of Yuma Terrain in the Middle East Desert; 2

  20. Women in the Gobi Desert

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    THE plane flew for about an hour,transporting me from Beijing to adeserted land,the Gobi desert,where sits the China Arms Testing &Training Target Field.For about 40 years,thousands of scientists and technicianshave made hundreds of greatachievements in the history of Chinesearms testing;among them are a lot ofunusual women making their own quietcontributions.

  1. On a Crowded Desert Island.

    Science.gov (United States)

    Rothstein, Samuel

    1989-01-01

    Suggests reference sources most appropriate for a desert island. In addition to "Robinson Crusoe" (Daniel Defoe) and a reference guide to the literature of travel, the list includes basic books on reference work, guides to reference sources, journals, an almanac, encyclopedias, a guide to English usage, and a book of quotations. (14 references)…

  2. Desert Pathfinder at Work

    Science.gov (United States)

    2005-09-01

    The Atacama Pathfinder Experiment (APEX) project celebrates the inauguration of its outstanding 12-m telescope, located on the 5100m high Chajnantor plateau in the Atacama Desert (Chile). The APEX telescope, designed to work at sub-millimetre wavelengths, in the 0.2 to 1.5 mm range, passed successfully its Science Verification phase in July, and since then is performing regular science observations. This new front-line facility provides access to the "Cold Universe" with unprecedented sensitivity and image quality. After months of careful efforts to set up the telescope to work at the best possible technical level, those involved in the project are looking with satisfaction at the fruit of their labour: APEX is not only fully operational, it has already provided important scientific results. "The superb sensitivity of our detectors together with the excellence of the site allow fantastic observations that would not be possible with any other telescope in the world," said Karl Menten, Director of the group for Millimeter and Sub-Millimeter Astronomy at the Max-Planck-Institute for Radio Astronomy (MPIfR) and Principal Investigator of the APEX project. ESO PR Photo 30/05 ESO PR Photo 30/05 Sub-Millimetre Image of a Stellar Cradle [Preview - JPEG: 400 x 627 pix - 200k] [Normal - JPEG: 800 x 1254 pix - 503k] [Full Res - JPEG: 1539 x 2413 pix - 1.3M] Caption: ESO PR Photo 30/05 is an image of the giant molecular cloud G327 taken with APEX. More than 5000 spectra were taken in the J=3-2 line of the carbon monoxide molecule (CO), one of the best tracers of molecular clouds, in which star formation takes place. The bright peak in the north of the cloud is an evolved star forming region, where the gas is heated by a cluster of new stars. The most interesting region in the image is totally inconspicuous in CO: the G327 hot core, as seen in methanol contours. It is a truly exceptional source, and is one of the richest sources of emission from complex organic molecules in the

  3. Assessing shrub encroachment in a grassland-shrubland desert ecotone using the relationship between remote sensed phenology of vegetation and precipitation

    Science.gov (United States)

    Moreno de las Heras, Mariano; Diaz-Sierra, Ruben; Wainwright, John

    2014-05-01

    monsoonal summer rainfall. For shrubs, NPP is better explained by winter plus summer precipitation, overlapping the monsoonal period of rain concentration. Our results suggest that a precipitation drift driven by reductions in monsoonal summer rainfall and increases in winter precipitation may enhance the shrub-encroachment process in the desert grasslands studied in the American Southwest.

  4. Exercise Desert Rock Letter Orders. Army, Camp Desert Rock, Nevada.

    Science.gov (United States)

    1957-08-01

    WILF.iED J MSGT A19032i3 HJ;,ŕWAY, ELLafGzJN 8FC Xf,37791267 INOZ W, P. 1. PVT2 US52401808 KELLEY, JESSIE J SFC R1� EVaS, LOUIS PFC .,53073109...Ord Co (HAM) Camo Desert Rock, Nevada You will preeeed to Reynolds Funeral Vome, Sigourney, Iowa 0/a 24 AU ist 1957 for apprx fourteen (14) days to

  5. Seed dispersal of desert annuals.

    Science.gov (United States)

    Venable, D Lawrence; Flores-Martinez, Arturo; Muller-Landau, Helene C; Barron-Gafford, Greg; Becerra, Judith X

    2008-08-01

    We quantified seed dispersal in a guild of Sonoran Desert winter desert annuals at a protected natural field site in Tucson, Arizona, USA. Seed production was suppressed under shrub canopies, in the open areas between shrubs, or both by applying an herbicide prior to seed set in large, randomly assigned removal plots (10-30 m diameter). Seedlings were censused along transects crossing the reproductive suppression borders shortly after germination. Dispersal kernels were estimated for Pectocarya recurvata and Schismus barbatus from the change in seedling densities with distance from these borders via inverse modeling. Estimated dispersal distances were short, with most seeds traveling less than a meter. The adhesive seeds of P. recurvata went farther than the small S. barbatus seeds, which have no obvious dispersal adaptation. Seeds dispersed farther downslope than upslope and farther when dispersing into open areas than when dispersing into shrubs. Dispersal distances were short relative to the pattern of spatial heterogeneity created by the shrub and open space mosaic. This suggests that dispersal could contribute to local population buildup, possibly facilitating species coexistence. Overall, these results support the hypothesis that escape in time via delayed germination is likely to be more important for desert annuals than escape in space.

  6. Distribution of sand dunes and sand shifts along the southern fringe of the Mu Us Desert since the Ming Dynasty

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This article takes the two segments of the Ming Great Walls, Dabian and Erbian, and their associated barracks and forts as geographical references. Based on a detailed scrutiny of historical records of the Ming and Qing dynasties, and on field surveys, the southern boundaries of the sand dunes and sand shifts of the Mu Us Desert in the Ming and Qing dynasties are carefully reconstructed. A comparison of the southern boundaries of the sand dunes and sand shifts of the Mu Us Desert in Ming and Qing with the modern boundary revealed in remote sensing imagery clearly shows that the southern boundary of dunes and shifts in the Mu us Desert has expanded only in a few areas and on a small scale. In the area to the south of Changle Fort, along the direction of annually prevailing winds, sand drifts have penetrated through the Jialu River valley into the loess region and have formed a sand strip of 32 km long and 3 km wide. To the east of Qingping Fort, sand drifts penetrated toward the eastern loess region through the Luhe River valley and have formed another sand strip of 8 km long and 2 km wide. Generally speaking, though the intensity of human activity has been increasing in this area since the Ming Dynasty, the Mu Us Desert has not significantly expanded toward the southeast or southwest. The sand-loess boundary in the southern fringe of the Mu Us Desert has been almost unchanged since the Ming Dynasty.

  7. Network topology of the desert rose

    Directory of Open Access Journals (Sweden)

    Sigmund Mongstad Hope

    2015-09-01

    Full Text Available Desert roses are gypsum crystals that consist of intersecting disks. We determine their geometrical structure using computer assisted tomography. By mapping the geometrical structure onto a graph, the topology of the desert rose is analyzed and compared to a model based on diffusion limited aggregation. By comparing the topology, we find that the model gets a number of the features of the real desert rose right, whereas others do not fit so well.

  8. EFFECTS OF ELEVATED CO2 ON ROOT FUNCTION AND SOIL RESPIRATION IN A MOJAVE DESERT ECOSYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Robert S.

    2007-12-19

    Increases in atmospheric CO{sub 2} concentration during the last 250 years are unequivocal, and CO{sub 2} will continue to increase at least for the next several decades (Houghton et al. 2001, Keeling & Whorf 2002). Arid ecosystems are some of the most important biomes globally on a land surface area basis, are increasing in area at an alarming pace (Dregne 1991), and have a strong coupling with regional climate (Asner & Heidebrecht 2005). These water-limited ecosystems also are predicted to be the most sensitive to elevated CO{sub 2}, in part because they are stressful environments where plant responses to elevated CO{sub 2} may be amplified (Strain & Bazzaz 1983). Indeed, all C{sub 3} species examined at the Nevada Desert FACE Facility (NDFF) have shown increased A{sub net} under elevated CO{sub 2} (Ellsworth et al. 2004, Naumburg et al. 2003, Nowak et al. 2004). Furthermore, increased shoot growth for individual species under elevated CO{sub 2} was spectacular in a very wet year (Smith et al. 2000), although the response in low to average precipitation years has been smaller (Housman et al. 2006). Increases in perennial cover and biomass at the NDFF are consistent with long term trends in the Mojave Desert and elsewhere in the Southwest, indicating C sequestration in woody biomass (Potter et al. 2006). Elevated CO{sub 2} also increases belowground net primary production (BNPP), with average increases of 70%, 21%, and 11% for forests, bogs, and grasslands, respectively (Nowak et al. 2004). Although detailed studies of elevated CO{sub 2} responses for desert root systems were virtually non-existent prior to our research, we anticipated that C sequestration may occur by desert root systems for several reasons. First, desert ecosystems exhibit increases in net photosynthesis and primary production at elevated CO{sub 2}. If large quantities of root litter enter the ecosystem at a time when most decomposers are inactive, significant quantities of carbon may be stored

  9. Ritual drinks in the pre-Hispanic US Southwest and Mexican Northwest.

    Science.gov (United States)

    Crown, Patricia L; Gu, Jiyan; Hurst, W Jeffrey; Ward, Timothy J; Bravenec, Ardith D; Ali, Syed; Kebert, Laura; Berch, Marlaina; Redman, Erin; Lyons, Patrick D; Merewether, Jamie; Phillips, David A; Reed, Lori S; Woodson, Kyle

    2015-09-15

    Chemical analyses of organic residues in fragments of pottery from 18 sites in the US Southwest and Mexican Northwest reveal combinations of methylxanthines (caffeine, theobromine, and theophylline) indicative of stimulant drinks, probably concocted using either cacao or holly leaves and twigs. The results cover a time period from around A.D. 750-1400, and a spatial distribution from southern Colorado to northern Chihuahua. As with populations located throughout much of North and South America, groups in the US Southwest and Mexican Northwest likely consumed stimulant drinks in communal, ritual gatherings. The results have implications for economic and social relations among North American populations.

  10. Smoking rates low in southwest

    Directory of Open Access Journals (Sweden)

    Robbins RA

    2014-04-01

    Full Text Available No abstract available. Article truncated at 150 words. The Gallup survey confirms that smoking rates in the US are declining and that smoking rates are lower in the Southwest than the US as a whole (1. Nationally, the smoking rate fell to 19.7% in 2013 from 21.1% in 2008. Among the Southwest states California ranked second (15.0%, Colorado ninth (17.4%, and Arizona tenth (17.5%. Only New Mexico was above the Nation's average at 20.0%. Utah remains the state with the lowest percentage of smokers, 12.2 percent, and Kentucky the highest, 30.2 percent. Nine of the 10 states with the lowest smoking rates have outright bans on smoking in private worksites, restaurants, and bars, with California allowing for ventilated rooms. Bans are significantly less common in the 10 states with the highest smoking rates. Kentucky, West Virginia, and Mississippi -- the states with the three highest smoking rates -- do not have statewide smoking bans. In addition, these three ...

  11. Tradeoffs and synergies between biofuel production and large-scale solar infrastructure in deserts

    Science.gov (United States)

    Ravi, S.; Lobell, D. B.; Field, C. B.

    2012-12-01

    Solar energy installations in deserts are on the rise, fueled by technological advances and policy changes. Deserts, with a combination of high solar radiation and availability of large areas unusable for crop production are ideal locations for large scale solar installations. For efficient power generation, solar infrastructures require large amounts of water for operation (mostly for cleaning panels and dust suppression), leading to significant moisture additions to desert soil. A pertinent question is how to use the moisture inputs for sustainable agriculture/biofuel production. We investigated the water requirements for large solar infrastructures in North American deserts and explored the possibilities for integrating biofuel production with solar infrastructure. In co-located systems the possible decline in yields due to shading by solar panels may be offsetted by the benefits of periodic water addition to biofuel crops, simpler dust management and more efficient power generation in solar installations, and decreased impacts on natural habitats and scarce resources in deserts. In particular, we evaluated the potential to integrate solar infrastructure with biomass feedstocks that grow in arid and semi-arid lands (Agave Spp), which are found to produce high yields with minimal water inputs. To this end, we conducted detailed life cycle analysis for these coupled agave biofuel - solar energy systems to explore the tradeoffs and synergies, in the context of energy input-output, water use and carbon emissions.

  12. A River in the Desert

    Institute of Scientific and Technical Information of China (English)

    杨仲言

    1994-01-01

    The Arabian Peninsula today is a barren desert. But 6,000 yearsago, says Farouk El-Baz,a river ran through the heart of the peninsula.From the Hijaz Mountains in western Saudi Arabia, it flowed 530 milesnortheast, emptying into the Persian Gulf through a delta that coveredmost of present day Kuwait. The Kuwait River, as El-Baz has dubbedit, averaged 5 miles wide and 50 feet deep along its entire length, and itcarried gravel from the Hijaz all the way to Kuwait. "It must have been amighty river, "says El-Baz.

  13. Simplified analysis of naturally ventilated desert buildings

    Energy Technology Data Exchange (ETDEWEB)

    Mathews, E.H.; Richards, P.G.; Rousseau, P.G. (Pretoria Univ. (South Africa). Dept. of Mechanical Engineering); Etzion, Y.; Erell, E. (Ben-Gurion Univ. of the Negev, Sede Boqer (Israel). J. Blaustein Inst. for Desert Research)

    1992-10-01

    The verification of a simplified thermal analysis procedure and its application to naturally ventilated desert buildings are discussed. Measurements for buildings in the Negev Desert, made independently by the Desert Architecture Unit of the Jacob Blaustein Institute for Desert Research, were inter alia used to verify the simplified thermal analysis procedure QUICK, developed by the Centre for Experimental and Numerical Thermoflow. As detailed information for validation purposes is not always readily available to researchers, the measurements as well as the buildings' descriptions are given in detail in this paper. The effect of natural ventilation strategies on the indoor air temperatures is also investigated for the desert buildings. A simplified but novel procedure to calculate the air change rates through the building from the measured wind speeds, building geometry and surroundings is proposed. Hourly air change rates determined with the proposed procedure are employed in the simulations with QUICK. (author)

  14. Wildlife conservation and solar energy development in the Desert Southwest, United States

    Science.gov (United States)

    Lovich, Jeffrey E.; Ennen, Josua R.

    2011-01-01

    Large areas of public land are currently being permitted or evaluated for utility-scale solar energy development (USSED) in the southwestern United States, including areas with high biodiversity and protected species. However, peer-reviewed studies of the effects of USSED on wildlife are lacking. The potential effects of the construction and the eventual decommissioning of solar energy facilities include the direct mortality of wildlife; environmental impacts of fugitive dust and dust suppressants; destruction and modification of habitat, including the impacts of roads; and off-site impacts related to construction material acquisition, processing, and transportation. The potential effects of the operation and maintenance of the facilities include habitat fragmentation and barriers to gene flow, increased noise, electromagnetic field generation, microclimate alteration, pollution, water consumption, and fire. Facility design effects, the efficacy of site-selection criteria, and the cumulative effects of USSED on regional wildlife populations are unknown. Currently available peer-reviewed data are insufficient to allow a rigorous assessment of the impact of USSED on wildlife.

  15. Stratospheric contribution to surface ozone in the desert Southwest during the 2013 Las Vegas Ozone Study

    Science.gov (United States)

    Langford, A. O.; Senff, C. J.; Alvarez, R. J. _II, II; Brioude, J. F.; Cooper, O. R.; Holloway, J. S.; Lin, M.; Marchbanks, R.; Pierce, R. B.; Reddy, P. J.; Sandberg, S.; Weickmann, A. M.; Williams, E. J.; Gustin, M. S.; Iraci, L. T.; Leblanc, T.; Yates, E. L.

    2014-12-01

    The 2013 Las Vegas Ozone Study (LVOS) was designed to investigate the potential impact of stratosphere-troposphere transport (STT) and long-range transport of pollution from Asia on surface O3 concentrations in Clark County, NV. This measurement campaign, which took place in May and June of 2013, was conducted at Angel Peak, NV, a high elevation site about 2.8 km above mean sea level and 45 km west of Las Vegas. The study was organized around the NOAA ESRL truck-based TOPAZ scanning ozone lidar with collocated in situ sampling of O3, CO, and meteorological parameters. These measurements were supported by the NOAA/NESDIS real time modelling system (RAQMS), FLEXPART particle dispersion model, and the NOAA GFDL AM3 model. In this talk, I will describe one of several STT events that occurred during the LVOS campaign. This intrusion, which was profiled by TOPAZ on the night of May 24-25, was also sampled by the NASA Alpha Jet, the Table Mountain ozone lidar, and by an ozonesonde flying above southern California. This event also led to significant ozone increases at surface monitors operated by Clark County, the California Air Resources Board, the U.S. National Park Service, and the Nevada Rural Ozone Initiative (NRVOI), and resulted in exceedances of the 2008 75 ppbv O3 NAAQS both in Clark County and in surrounding areas of Nevada and southern California. The potential implications of this and similar events for air quality compliance in the western U.S. will be discussed.

  16. Drug Violence Along the Southwest Border: Another American Punitive Expedition?

    Science.gov (United States)

    2011-03-16

    bilateral relationship between Mexico and the United States. NAFTA brought economic and social benefits to the Mexican economy, such as the growth...42. 25 36 Grupo Aeromovil de Fuerzas Especial 37 Grupo Anfibios de Fuerzas Especial 38 Graham H. Turbiville, Jr., U.S. Military Engagement with

  17. Evidence of cacao use in the Prehispanic American Southwest.

    Science.gov (United States)

    Crown, Patricia L; Hurst, W Jeffrey

    2009-02-17

    Chemical analyses of organic residues in fragments of ceramic vessels from Pueblo Bonito in Chaco Canyon, New Mexico, reveal theobromine, a biomarker for cacao. With an estimated 800 rooms, Pueblo Bonito is the largest archaeological site in Chaco Canyon and was the center of a large number of interconnected towns and villages spread over northwestern New Mexico. The cacao residues come from pieces of vessels that are likely cylinder jars, special containers occurring almost solely at Pueblo Bonito and deposited in caches at the site. This first known use of cacao drinks north of the Mexican border indicates exchange with cacao cultivators in Mesoamerica in a time frame of about A.D. 1000-1125. The association of cylinder jars and cacao beverages suggests that the Chacoan ritual involving the drinking of cacao was tied to Mesoamerican rituals incorporating cylindrical vases and cacao. The importance of Pueblo Bonito within the Chacoan world likely lies in part with the integration of Mesoamerican ritual, including critical culinary ingredients.

  18. Evidence of cacao use in the Prehispanic American Southwest

    OpenAIRE

    Crown, Patricia L.; Hurst, W. Jeffrey

    2009-01-01

    Chemical analyses of organic residues in fragments of ceramic vessels from Pueblo Bonito in Chaco Canyon, New Mexico, reveal theobromine, a biomarker for cacao. With an estimated 800 rooms, Pueblo Bonito is the largest archaeological site in Chaco Canyon and was the center of a large number of interconnected towns and villages spread over northwestern New Mexico. The cacao residues come from pieces of vessels that are likely cylinder jars, special containers occurring almost solely at Pueblo ...

  19. Transition of surface energy budget in the Gobi Desert between spring and summer seasons

    Science.gov (United States)

    Smith, Eric A.; Reiter, Elmar R.; Gao, Youxi

    1986-01-01

    The surface energetics of the southwest Gobi Desert, including the temporal variations and diurnally averaged properties of the surface energy budget components, was investigated. The field program was conducted during the spring and summer of 1984, with the measurement system designed to monitor radiative exchange, heat/moisture storage in the soil, and sensible and latent heat exhange between the ground and the atmosphere. Results of the analysis reveal a seasonal transition feature not expected of a midlatitude desert. Namely, the differences in both surface radiation exchange and the distibution of sensible and latent heat transfer arise within a radiatively forced environment that barely deviates from spring to summer in terms of available solar energy at the surface. Both similarities and differences in the spring and summer surface energy budgets arise from differences imparted to the system by an increase in the summertime atmospheric moisture content. Changes in the near-surface mixing ratio are shown to alter the effectiveness of the desert surface in absorbing radiative energy and redistibuting it to the lower atmosphere through sensible and latent heat exchange.

  20. Competing Interests and Concerns in the Rio Grande Basin: Mountain Hydrology, Desert Ecology, Climate Change, and Population Growth

    Science.gov (United States)

    Rango, A.

    2004-12-01

    In the mountainous American Southwest, the Rio Grande basin is a prime example of how conflicts, misconceptions, and competition regarding water can arise in arid and semi-arid catchments. Much of the Rio Grande runoff originates from snow fields in the San Juan Mountains of southern Colorado and the Sangre De Cristo Mountains of northern New Mexico, far from population centers. Large and rapidly growing cities, like Albuquerque, Las Cruces, El Paso, and Juarez, are located along the Rio Grande where it flows through the Chihuahuan Desert, the largest desert in North America(two NSF Long Term Ecological Research sites are located in the desert portion of the basin). As a result, the importance of snowmelt, which makes up 50-75% or more of the total streamflow in sub-basins above Elephant Butte Reservoir(in south central New Mexico) is hardly known to the general public. Streamflow below Elephant Butte Reservoir is rainfall driven and very limited, with the lower basin receiving only 170-380 mm of precipitation annually, most of it occurring during the months of July-September. Extreme events, such as drought and flooding, are not unusual in arid basins, and they are of increasing concern with regard to changes in frequency of such events under the impending conditions of climate change. Current water demands in the basin already exceed the water supply by 15% or more, so streamflow forecasts(especially from snowmelt runoff) are extremely valuable for efficient water management as well as for proper apportionment of water between Colorado, New Mexico, and Texas under the Rio Grande Compact of 1938 and between the U.S. and Mexico under the Treaty of 1906. Other demands on the water supply include Indian water rights, flood regulation, irrigated agriculture, municipal and industrial demands, water quality, riverine and riparian habitat protection, endangered and threatened species protection, recreation, and hydropower. To assess snow accumulation and cover and to

  1. Deserts

    DEFF Research Database (Denmark)

    Graulund, Rune

    2016-01-01

    examines: •Key debates within the field, including postcolonial studies, gender, sexuality and visual culture •Historical and cultural contexts, tracing the evolution of travel writing across time and over cultures •Different styles, modes and themes of travel writing, from pilgrimage to tourism •Imagined...... geographies, and the relationship between travel writing and the social, ideological and occasionally fictional constructs through which we view the different regions of the world. Covering all of the major topics and debates, this is an essential overview of the field, which will also encourage new...

  2. Development of Hydropower Resources in Southwest China

    Institute of Scientific and Technical Information of China (English)

    Du Zhongming; Wu Yun; Tong Mingdong; Xiao Jinyu

    2009-01-01

    @@ There is a boom of hydropower development in Southwest China recently because of the abundant hydropower resources there,especially in Yunnan and Sichuan provinces,which has attracted the attentions of various major power generation companies and private enterprises.Based on the situation of hydropower development in the Southwest and combined with the analysis of prospective receiving market and the capability of electrical and mechanical equipment's manufacturing,this paper discusses the main problems of the hydropower development in the Southwest and makes some suggestions for its orderly development and efficient utilization.

  3. A long-term vegetation history of the Mojave-Colorado Desert ecotone at Joshua Tree National Park

    Science.gov (United States)

    Holmgren, Camille A.; Betancourt, Julio L.; Rylander, Kate A.

    2010-01-01

    Thirty-eight dated packrat middens were collected from upper desert (930-1357?m) elevations within Joshua Tree National Park near the ecotone between the Mojave Desert and Colorado Desert, providing a 30?ka record of vegetation change with remarkably even coverage for the last 15?ka. This record indicates that vegetation was relatively stable, which may reflect the lack of invasion by extralocal species during the late glacial and the early establishment and persistence of many desert scrub elements. Many of the species found in the modern vegetation assemblages were present by the early Holocene, as indicated by increasing S?renson\\'s Similarity Index values. C4 grasses and summer-flowering annuals arrived later at Joshua Tree National Park in the early Holocene, suggesting a delayed onset of warm-season monsoonal precipitation compared to other Sonoran Desert and Chihuahuan Desert localities to the east, where summer rains and C4 grasses persisted through the last glacial?interglacial cycle. This would suggest that contemporary flow of monsoonal moisture into eastern California is secondary to the core processes of the North American Monsoon, which remained intact throughout the late Quaternary. In the Holocene, northward displacement of the jet stream, in both summer and winter, allowed migration of the subtropical ridge as far north as southern Idaho and the advection of monsoonal moisture both westward into eastern California and northward into the southern Great Basin and Colorado Plateau. Copyright 2009 John Wiley & Sons, Ltd.

  4. Consequences of long-term changes in seasonal precipitation for the biochemistry of photosynthesis in dominant desert shrubs and grasses

    Science.gov (United States)

    Bentley, L. P.; Ogle, K.; Loik, M. E.; Huxman, T. E.; Smith, S. D.; Tissue, D.

    2011-12-01

    Alterations in seasonal precipitation have been demonstrated to have short-term effects on biochemical limitations to photosynthesis, but longer-term effects on plant biochemistry are generally unknown. This study explores the long-term impacts of altered precipitation on the photosynthetic biochemistry of seven dominant desert plants. Seasonal precipitation was experimentally manipulated (addition and/or exclusion) for 5-6 years in four North American deserts prior to a 2-year campaign of photosynthetic measurements. Photosynthetic response curve data were analyzed via a novel hierarchical Bayesian model that enabled the estimation of biochemical limitations to photosynthesis in C3 and C4 plants, while simultaneously incorporating precipitation treatment effects. In the Chihuahuan Desert, an increase in both summer and winter precipitation increased biochemical efficiency in a C3 woody monocot. In the Sonoran Desert, increased winter precipitation increased biochemical efficiency in a C4 non-native grass. Precipitation treatment effects were lacking in the Mojave and Great Basin Deserts, perhaps due to low summer precipitation in these deserts. Seasonal precipitation differentially affects plant- and species-level carbon dynamics over the long-term due to the timing of precipitation and the interaction of precipitation with nitrogen dynamics. Our results emphasize the importance of studying longer-term biochemical responses to changes in environmental conditions because they may not reflect short-term stomatal responses.

  5. Rural childhoods in Egypt's desert lands

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine

    Based on fieldwork in Egypt’s desert lands, this paper discusses rural childhoods in an area experiencing rapid social and cultural change. Since 1987, the Egyptian Government has made new villages in the desert as a means to increase agricultural production and solving problems of unemployment......’s new roles impact upon the children’s lives. The social contexts shaping the desert childhoods are in some ways more similar to contexts in ‘developed’ countries than in other parts of rural Egypt. The paper ends up by contrasting ideas of rural childhoods in Egypt with those found in ‘developed...

  6. Microphytic crusts: 'topsoil' of the desert

    Science.gov (United States)

    Belnap, Jayne

    1990-01-01

    Deserts throughout the world are the home of microphytic, or cryptogamic, crusts. These crusts are dominated by cyanobacteria, previously called blue-green algae, and also include lichens, mosses, green algae, microfungi and bacteria. They are critical components of desert ecosystems, significantly modifying the surfaces on which they occur. In the cold deserts of the Colorado Plateau (including parts of Utah, Arizona, Colorado, and New Mexico), these crusts are extraordinarily well-developed, and may represent 70-80% of the living ground cover.

  7. Problems with the North American Monsoon in CMIP/IPCC GCM Precipitation

    Science.gov (United States)

    Schiffer, N. J.; Nesbitt, S. W.

    2011-12-01

    Successful water management in the Desert Southwest and surrounding areas hinges on anticipating the timing and distribution of precipitation. IPCC AR4 models predict a more arid climate, more extreme precipitation events, and an earlier peak in springtime streamflow in the North American Monsoon region as the area warms. This study aims to assess the summertime skill with which general circulation models (GCMs) simulate precipitation and related dynamics over this region, a necessary precursor to reliable hydroclimate projections. Thirty-year climatologies of several GCMs in the third and fifth Climate Model Intercomparison Projects (CMIP) are statistically evaluated against each other and observed climatology for their skill in representing the location, timing, variability, character, and large-scale forcing of precipitation over the southwestern United States and northwestern Mexico. The results of this study will lend greater credence to more detailed, higher resolution studies, based on the CMIP and IPCC models, of the region's future hydrology. Our ultimate goal is to provide guidance such that decision-makers can plan future water management with more confidence.

  8. Southwest Florida Shelf Ecosystems Analysis Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Southwest Florida Shelf Ecosystems Analysis Study produced grain size analyses in the historic 073 format for 299 sea floor samples collected from October 25,...

  9. Proposed Desert Pupfish Preserve : Supplemental LARC Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document contains supplements to a previous report on the desert pupfish preserve proposal. The attachments are titled: “Vertebrate Animals and Vascular...

  10. Impact of the Desert dust on the summer monsoon system over Southwestern North America

    Directory of Open Access Journals (Sweden)

    C. Zhao

    2012-04-01

    Full Text Available The radiative forcing of dust emitted from the Southwest United States (US deserts and its impact on monsoon circulation and precipitation over the North America monsoon (NAM region are simulated using a coupled meteorology and aerosol/chemistry model (WRF-Chem for 15 years (1995–2009. During the monsoon season, dust has a cooling effect (−0.90 W m−2 at the surface, a warming effect (0.40 W m−2 in the atmosphere, and a negative top-of-the-atmosphere (TOA forcing (−0.50 W m−2 over the deserts on 24-h average. Most of the dust emitted from the deserts concentrates below 800 hPa and accumulates over the western slope of the Rocky Mountains and Mexican Plateau. The absorption of shortwave radiation by dust heats the lower atmosphere by up to 0.5 K day−1 over the western slope of the Mountains. Model sensitivity simulations with and without dust for 15 summers (June-July-August show that dust heating of the lower atmosphere over the deserts strengthens the low-level southerly moisture fluxes on both sides of the Sierra Madre Occidental. It also results in an eastward migration of NAM-driven moisture convergence over the western slope of the Mountains. These monsoonal circulation changes lead to a statistically significant increase of precipitation by up to ~40 % over the eastern slope of the Mountains (Arizona-New~Mexico-Texas regions. This study highlights the interaction between dust and the NAM system and motivates further investigation of possible dust feedback on monsoon precipitation under climate change and the mega-drought conditions projected for the future.

  11. Severe weather during the North American monsoon and its response to rapid urbanization and a changing global climate within the context of high resolution regional atmospheric modeling

    Science.gov (United States)

    Luong, Thang Manh

    The North American monsoon (NAM) is the principal driver of summer severe weather in the Southwest U.S. With sufficient atmospheric instability and moisture, monsoon convection initiates during daytime in the mountains and later may organize, principally into mesoscale convective systems (MCSs). Most monsoon-related severe weather occurs in association with organized convection, including microbursts, dust storms, flash flooding and lightning. The overarching theme of this dissertation research is to investigate simulation of monsoon severe weather due to organized convection within the use of regional atmospheric modeling. A commonly used cumulus parameterization scheme has been modified to better account for dynamic pressure effects, resulting in an improved representation of a simulated MCS during the North American monsoon experiment and the climatology of warm season precipitation in a long-term regional climate model simulation. The effect of urbanization on organized convection occurring in Phoenix is evaluated in model sensitivity experiments using an urban canopy model (UCM) and urban land cover compared to pre-settlement natural desert land cover. The presence of vegetation and irrigation makes Phoenix a "heat sink" in comparison to its surrounding desert, and as a result the modeled precipitation in response to urbanization decreases within the Phoenix urban area and increase on its periphery. Finally, analysis of how monsoon severe weather is changing in association with observed global climate change is considered within the context of a series of retrospectively simulated severe weather events during the period 1948-2010 in a numerical weather prediction paradigm. The individual severe weather events are identified by favorable thermodynamic conditions of instability and atmospheric moisture (precipitable water). Changes in precipitation extremes are evaluated with extreme value statistics. During the last several decades, there has been

  12. Southwest ballot measures affecting healthcare

    Directory of Open Access Journals (Sweden)

    Robbins RA

    2016-11-01

    Full Text Available No abstract available. Article truncated after 150 words. Modern Healthcare (1 has published an article summarizing ballot measures affecting healthcare. Those from the Southwest are listed below: States: Arizona: 1. Recreational marijuana. Proposition 205: Legalizes recreational marijuana use for people 21 and older. Opponents of the measure include the Arizona Health and Hospital Association and Insys Therapeutics, a company that makes a cannabis-based pain medication. California : 1. Medi-Cal hospital fee program. Proposition 52: Requires the legislature to get voter approval to use fee revenue for purposes other than generating federal matching funds and funding enhanced Medicaid payments and grants for hospitals. The initiative, which was written by the California Hospital Association and is supported by most state lawmakers, would also make the program permanent, requiring a supermajority in the legislature to end it. 2. Tobacco tax. Proposition 56: Increases the state's cigarette tax by $2 a pack and impose an "equivalent increase on other tobacco products and ...

  13. Folk medicine in the Southwest. Myths and medical facts.

    Science.gov (United States)

    Trotter, R T

    1985-12-01

    The three folk illnesses described in this article--caida de mollera, susto, and empacho--can all be linked to recognized biologic conditions and therefore cannot be analyzed solely on the basis of sociocultural factors. Clearly, it would be a mistake to continue ignoring these syndromes in the Southwest on the assumption that they are "all in the mind" of Mexican-American patients. They must be assessed from the view that they are culturally different labels for serious medical conditions (eg, caida de mollera), that they are useful screening labels for patients with high disease loads (eg, susto), or that they are harmless in and of themselves but their treatment may have significant medical consequences (eg, empacho).

  14. Historic Distrust and the Counseling of American Indians and Alaska Natives.

    Science.gov (United States)

    Lockart, Barbetta

    1981-01-01

    Since establishment of trust is crucial to counseling relationships, American Indian distrust of non-Indians must be dealt with for successful counseling. Available from: White Cloud Center, Gaines Hall UOHSC, 840 Southwest Gaines Road, Portland, OR 97201. (CM)

  15. Complex Fault Interaction in the Yuha Desert

    Science.gov (United States)

    Kroll, K.; Cochran, E. S.; Richards-Dinger, K. B.; Sumy, D. F.

    2012-12-01

    We determine precise hypocentral locations for over 3,600 aftershocks that occurred in the Yuha Desert (YD) region following the 4 April 2010 Mw 7.2 El Mayor-Cucapah (EMC) earthquake until 14 June 2010 originally located by the Southern California Seismic Network (SCSN). To calculate precise hypocenters we used manually identified phase arrivals and cross-correlation delay times in a series of absolute and relative relocation procedures with algorithms including hypoinverse, velest and hypoDD. We used velest to simultaneously invert for station corrections and the best-fitting velocity model for the event and station distribution. Location errors were reduced with this process to ~20 m horizontally and ~80 m vertically. The locations reveal a complex pattern of faulting with en echelon fault segments trending toward the northwest, approximately parallel to the North American-Pacific plate boundary and en echelon, conjugate features trending to the northeast. The relocated seismicity is highly correlated with the mapped faults that show triggered surface slip in response to the EMC mainshock. Aftershocks are located between depths of 2 km and 11 km, consistent with previous studies of seismogenic thickness in the region. Three-dimensional analysis reveals individual and intersecting fault planes between 5 km and 10 km in the along-strike and along-dip directions. These fault planes remain distinct structures at depth, indicative of conjugate faulting, and do not appear to coalesce onto a through-going fault segment. We observe a complex spatiotemporal migration of aftershocks with individual fault strands that are often active for relatively short time periods. In addition, events relocated by Hauksson et al., (2012) that occur in the two-year period following the 15 June 2010 M5.7 Ocotillo earthquake show majority of seismicity occurred along the Laguna Salada-West branch. At the same time, seismicity along the Laguna Salada-East and other faults in the Yuha Desert

  16. Traditional cultural use as a tool for inferring biogeography and provenance: a case study involving painted turtles (Chrysemys picta) and Hopi Native American culture in Arizona, USA

    Science.gov (United States)

    Lovich, Jeffrey E.; LaRue, Charles T.; Drost, Charles A.; Arundel, Terence R.

    2014-01-01

    Inferring the natural distribution and native status of organisms is complicated by the role of ancient and modern humans in utilization and translocation. Archaeological data and traditional cultural use provide tools for resolving these issues. Although the painted turtle (Chrysemys picta) has a transcontinental range in the United States, populations in the Desert Southwest are scattered and isolated. This pattern may be related to the fragmentation of a more continuous distribution as a result of climate change after the Pleistocene, or translocation by Native Americans who used turtles for food and ceremonial purposes. Because of these conflicting or potentially confounded possibilities, the distribution and status of C. picta as a native species in the state of Arizona has been questioned in the herpetological literature. We present evidence of a population that once occurred in the vicinity of Winslow, Arizona, far from current remnant populations on the upper Little Colorado River. Members of the Native American Hopi tribe are known to have hunted turtles for ceremonial purposes in this area as far back as AD 1290 and possibly earlier. Remains of C. picta are known from several pueblos in the vicinity including Homol'ovi, Awatovi, and Walpi. Given the great age of records for C. picta in Arizona and the concordance of its fragmented and isolated distribution with other reptiles in the region, we conclude that painted turtles are part of the native fauna of Arizona.

  17. Distribution of aquaporins in the nasal passage of Octodon degus, a South-American desert rodent and its implications for water conservation Distribución de acuaporinas en los pasajes nasales de Octodon degus, un roedor de ambientes desérticos sudamericanos: implicaciones en la conservación de agua

    Directory of Open Access Journals (Sweden)

    PEDRO GALLARDO

    2008-03-01

    Full Text Available Rodents from arid and semiarid environments live under conditions where the spatial and temporal availability of water is limited. Octodon degus is a South-American desert-dwelling rodent inhabiting arid and semiarid habitats of central and northern Chile. Its survival depends on morphological, physiological and behavioral adaptations that allow water conservation. This rodent has a high urine concentrating ability, high capacity of fecal dehydration and low evaporative water loss, related to the ability of the nasal passages to condense water from the exhaled air; this water must be absorbed in order to avoid its accumulation in the nasal passages and potential loss through the nostrils. We hypothesize that aquaporins (AQPs might be present in the nasal mucosa; therefore, we studied the distribution of AQP-1, AQP-2, AQP-3 and AQP-4 through immunocytochemistry. Intense AQP-1 labeling was observed throughout the subepithelial vascular network; no AQP-1 immunoreactivity was detected in olfactory and non-olfactory epithelial cells. No signal was detected for AQP-2 and 4. AQP-3 distribution was restricted to the surface non-olfactory epithelial cells lining the turbinates in narrow passages and blind spaces. Therefore, AQP-1 and AQP-3 coincided at the level of the turbinates, although in different cell types which suggest a pathway for water removal from the nasal surface first through AQP-3 in non-olfactory epithelial cells and then into the capillary lumen through AQP-1Los roedores de ambientes áridos y semiáridos viven bajo una disponibilidad limitada de agua tanto espacial como temporal. Octodon degus es un roedor sudamericano que habita ambientes áridos y semiáridos del norte y zona central de Chile. Su supervivencia depende de adaptaciones morfológicas, fisiológicas y conductuales que permiten optimizar la conservación de agua. Este tiene una alta capacidad de concentración urinaria y de deshidratación de la fecas además de una baja

  18. Desert dust hazards: A global review

    Science.gov (United States)

    Middleton, N. J.

    2017-02-01

    Dust storms originate in many of the world's drylands and frequently present hazards to human society, both within the drylands themselves but also outside drylands due to long-range transport of aeolian sediments. Major sources of desert dust include the Sahara, the Middle East, central and eastern Asia, and parts of Australia, but dust-raising occurs all across the global drylands and, on occasion, beyond. Dust storms occur throughout the year and they vary in frequency and intensity over a number of timescales. Long-range transport of desert dust typically takes place along seasonal transport paths. Desert dust hazards are here reviewed according to the three phases of the wind erosion system: where dust is entrained, during the transport phase, and on deposition. This paper presents a synthesis of these hazards. It draws on empirical examples in physical geography, medical geology and geomorphology to discuss case studies from all over the world and in various fields. These include accelerated soil erosion in agricultural zones - where dust storms represent a severe form of accelerated soil erosion - the health effects of air pollution caused by desert aerosols via their physical, chemical and biological properties, transport accidents caused by poor visibility during desert dust events, and impacts on electricity generation and distribution. Given the importance of desert dust as a hazard to human societies, it is surprising to note that there have been relatively few attempts to assess their impact in economic terms. Existing studies in this regard are also reviewed, but the wide range of impacts discussed in this paper indicates that desert dust storms deserve more attention in this respect.

  19. On Separate Paths: The Mexican American and African American Legal Campaigns against School Segregation

    Science.gov (United States)

    Powers, Jeanne M.

    2014-01-01

    "Brown v. Board of Education" (1954) was a landmark decision that was the result of decades of efforts by grassroots activists and civil rights organizations to end legalized segregation. A less well-known effort challenged the extralegal segregation of Mexican American students in the Southwest. I combine original research and research…

  20. Hydrologic Literacy in the Southwest

    Science.gov (United States)

    Washburne, J.; Madden, J.

    2008-12-01

    Improving hydrologic literacy at all levels has been the keystone to the education mission at NSF's SAHRA Science and Technology Center since its inception in 2000. Water issues and water education are particularly relevant in the semi-arid southwest, which has experienced a series of droughts and tremendous growth throughout this period. One of our strategies has been to focus our efforts on the high school and undergraduate level, for which there are far fewer water education materials available. Early on, we worked with local water educators and employed an Understanding by Design methodology to develop a series of Enduring Understandings in the critical areas of water quality, aquatic life, watersheds and urban hydrology. These basic concepts have helped guide our development of content and training opportunities. A prime example of this process is our Watershed Visualization project, which includes a series of animated videos focused on understanding the geographic and hydrologic setting of the Verde Watershed in central Arizona. This series also addresses the interaction of climate and groundwater recharge in this rapidly changing area. This past year, we developed a new program called Arizona Rivers, which emphasizes local and student- based monitoring and research of the interactions between riparian hydrology and ecology. One key feature of this program is an extended summer field trip/research experience for high school students called the Riparian Research Experience. A goal of this program is to raise the level of critical analysis and environmental stewardship among high school students and their teachers. A more comprehensive effort of raising the hydrologic literacy of non-science university freshman has been taking place at the University of Arizona for the past five years through the general education course titled Arizona Water Issues or HWR203. This course focuses equally on fundamental hydrologic understandings, beginning with the water cycle as

  1. Classification of aerosol radiative properties during African desert dust intrusions over southeastern Spain by sector origins and cluster analysis

    Science.gov (United States)

    Valenzuela, A.; Olmo, F. J.; Lyamani, H.; Antón, M.; Quirantes, A.; Alados-Arboledas, L.

    2012-03-01

    The main goal of this study is to analyze the dependence of columnar aerosol optical and microphysical properties on source region and transport pathways during desert dust intrusions over Granada (Spain) from January 2005 to December 2010. Columnar aerosol properties have been derived from a non-spherical inversion code using the solar extinction measurements and sky radiances in the principal plane. Two classification methods of the African air masses ending at the study location were used by means of the HYSPLIT back-trajectories analysis. The first one, based on desert dust origin sources, discriminated the optical properties only for sector B (corresponding to western Sahara, northwest Mauritania and southwest Algeria). The particles present marked absorbing properties (low value of single scattering albedo at all wavelengths) during the desert dust events when the air masses were transported from sector A (north Morocco, northwest Algeria). This result may be related to the mixing of desert dust with anthropogenic pollutants from North African industrial areas in addition to the mixing with local anthropogenic aerosol and pollutants transported from European and Mediterranean areas. The second classification method was based on a statistics technique called cluster classification which allows grouping the air masses back trajectories with similar speed and direction of the trajectory. This method showed slight differences in the optical properties between the several transport pathways of air masses. High values of the aerosol optical depth and low mean values of the Angström parameter were associated with longer transport pathways over desert dust sources and slowly moving air masses. Both classification methods showed that the fine mode was mixed with coarse mode, being the fine mode fraction smaller than 55%.

  2. Desert Amplification in a Warming Climate

    Science.gov (United States)

    Zhou, Liming

    2016-08-01

    Here I analyze the observed and projected surface temperature anomalies over land between 50°S-50°N for the period 1950–2099 by large-scale ecoregion and find strongest warming consistently and persistently seen over driest ecoregions such as the Sahara desert and the Arabian Peninsula during various 30-year periods, pointing to desert amplification in a warming climate. This amplification enhances linearly with the global mean greenhouse gases(GHGs) radiative forcing and is attributable primarily to a stronger GHGs-enhanced downward longwave radiation forcing reaching the surface over drier ecoregions as a consequence of a warmer and thus moister atmosphere in response to increasing GHGs. These results indicate that desert amplification may represent a fundamental pattern of global warming associated with water vapor feedbacks over land in low- and mid- latitudes where surface warming rates depend inversely on ecosystem dryness. It is likely that desert amplification might involve two types of water vapor feedbacks that maximize respectively in the tropical upper troposphere and near the surface over deserts, with both being very dry and thus extremely sensitive to changes of water vapor.

  3. SOUTHWEST REGIONAL PARTNERSHIP ON CARBON SEQUESTRATION

    Energy Technology Data Exchange (ETDEWEB)

    Brian McPherson; Rick Allis; Barry Biediger; Joel Brown; Jim Cappa; George Guthrie; Richard Hughes; Eugene Kim; Robert Lee; Dennis Leppin; Charles Mankin; Orman Paananen; Rajesh Pawar; Tarla Peterson; Steve Rauzi; Jerry Stuth; Genevieve Young

    2004-11-01

    The Southwest Partnership Region includes six whole states, including Arizona, Colorado, Kansas, New Mexico, Oklahoma, and Utah, roughly one-third of Texas, and significant portions of adjacent states. The Partnership comprises a large, diverse group of expert organizations and individuals specializing in carbon sequestration science and engineering, as well as public policy and outreach. The main objective of the Southwest Partnership project is to achieve an 18% reduction in carbon intensity by 2012. The Partnership made great progress in this first year. Action plans for possible Phase II carbon sequestration pilot tests in the region are almost finished, including both technical and non-technical aspects necessary for developing and carrying out these pilot tests. All partners in the Partnership are taking an active role in evaluating and ranking optimum sites and technologies for capture and storage of CO{sub 2} in the Southwest Region. We are identifying potential gaps in all aspects of potential sequestration deployment issues.

  4. Vegetation Mapping of the Mond Protected Area of Bushehr Province (South-west Iran)

    Institute of Scientific and Technical Information of China (English)

    Ahmadreza Mehrabian; Alireza Naqinezhad; Abdolrassoul Salman Mahiny; Hossein Mostafavi; Homan Liaghati; Mohsen Kouchekzadeh

    2009-01-01

    Add regions of the wodd occupy up to 35% of the earth's surface, the basis of various definitions of climatic conditions,vegetation types or potential for food production. Due to their high ecological value, monitoring of add regions is necessary and modem vegetation studies can help in the conservation and management of these areas. The use of remote sensing for mapping of desert vegetation is difficult due to mixing of the spectral reflectance of bright desert soils with the weak spectral response of sparse vegetation. We studied the vegetation types in the semiarid to arid region of Mond Protected Area, south-west Iran, based on unsupervised classification of the Spot XS bands and then produced updated maps.Sixteen map units covering t2 vegetation types were recognized in the area based on both field works and satellite mapping. Halocnemum strobilaceum and Suaeda fruticosa vegetation types were the dominant types and Ephedra foliata,Salicornia europaaa-Suaeda heterophylla vegetation types were the smallest. Vegetation coverage decreased sharply with the increase in salinity towards the coastal areas of the Persian Gulf. The highest vegetation coverage belonged to the riparian vegetation along the Mond River, which represents the northern boundary of the protected area. The location of vegetation types was studied on the separate soil and habitat diversity maps of the study area, which helped in final refinements of the vegetation map produced.

  5. American Religion

    Institute of Scientific and Technical Information of China (English)

    田甜

    2008-01-01

    It is said that American religion,as a great part of American culture,plays an important role in American culture. It is hoped that some ideas can be obtained from this research paper,which focuses on analyzing the great impact is produced to American culture by American religion. Finally, this essay gives two useful standpoints to English learners:Understunding American religion will help understand the American history, culture and American people,and help you to communic.ate with them better. Understanding American religion will help you understand English better.

  6. SOUTHWEST REGIONAL PARTNERSHIP ON CARBON SEQUESTRATION

    Energy Technology Data Exchange (ETDEWEB)

    Brian McPherson

    2005-08-01

    The Southwest Partnership on Carbon Sequestration completed several more tasks during the period of October 1, 2004--March 31, 2005. The main objective of the Southwest Partnership project is to achieve an 18% reduction in carbon intensity by 2012. Action plans for possible Phase 2 carbon sequestration pilot tests in the region are completed, and a proposal was developed and submitted describing how the Partnership may develop and carry out appropriate pilot tests. The content of this report focuses on Phase 1 objectives completed during this reporting period.

  7. A Waste of a Desert: Nevada and the Cold War Chemical Legacy

    Directory of Open Access Journals (Sweden)

    Cinzia Scarpino

    2009-12-01

    Full Text Available Taking the lead from Don DeLillo’s epic novel Underworld (1997 – with its overarching theme of “waste” functioning as its unifying metaphor and its picture of the American deserts turned into hazardous waste dumps or missile depots – this essay provides a close reading of the empty spaces of the Nevada desert, spaces that bear the mark left by the nuclear exploitation and the hazardous waste which have plagued Nevada since the Fifties. By linking the history of Nevada to the Cold War, and to the chemical legacy of those years, with its notions of “containment” and “weather control”, Scarpino argues that they be read as interwoven threads of the same discourse.

  8. Ecological stability of Tarim Desert Highway shelterbelt

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhibin; XU Xinwen; LEI Jiaqiang; LI Shengyu

    2006-01-01

    The Tarim Desert Highway shelterbelt,located in hinterland of Taklimakan Desert, is irrigated by underground saline water, with three to thirty gram per litter mineral degrees. The sustainability and stability are affected by multifarious stress.The structural and functional characteristics of shelterbelt are studied to probe into correlation between environment and shelterbelt. On basis, decision analysis is applied to study ecological stability of the Tarim Desert Highway shelterbelt, to screen out limited factors, to establish general index system, and to evaluate the stability of the shelterbelt nowadays.Finally, the concept of ecological stability is utilized to manage the artificial ecosystem. The results show that the artificial ecosystem is relatively flimsy, whose stability can be increased by adjusting stand structure and improving the nutrient cycle.

  9. 2005 Southwest Florida Water Management District (SWFWMD) Lidar: Manatee District

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) LAS dataset is a survey of select areas within Southwest Florida. These data were produced for the Southwest Florida Water...

  10. The Punitive Paradox: Desert and the Compulsion to Punish.

    Science.gov (United States)

    Clear, Todd R.

    1996-01-01

    Explores the concept of a "just deserts" justice paradox in which carrying out a deserved penalty breaches the values that undergird the theory of just deserts. Examines whether it might ever be proper, from a desert perspective, to choose not to impose a deserved punishment. (KW)

  11. Long-term accumulation of atmospheric dust in rocky deserts

    NARCIS (Netherlands)

    Goossens, D.; Offer, Z.Y.

    2005-01-01

    The spatial pattern of long-term (hundreds to thousands of years) accumulation of dust in rocky deserts was investigated in the northern Negev Desert of Israel. The concentration of dust in the desert subsoil was measured at 41 locations in a 53 ha test area for which detailed information exists on

  12. Predatory bird populations in the east Mojave Desert, California

    Science.gov (United States)

    Knight, R.L.; Camp, R.J.; Boarman, W.I.; Knight, H.A.L.

    1999-01-01

    We surveyed 7 species of predatory birds weekly during a 12-month period (December 1992 through November 1993) in the east Mojave Desert, California. The Common Raven (Corvus corax) was the most frequently observed species with an average of 6.9 sightings per 100 km. Turkey Vultures (Cathartes aura), Red-tailed Hawks (Buteo jamaicensis), Loggerhead Shrikes (Lanius ludovicianus), American Kestrels (Falco sparverius), Golden Eagles (Aquila chrysaetos), and Prairie Falcons (Falco mexicanus) were seen in decreasing order of frequency of observation through the study period. Ravens, Red-tailed Hawks, Loggerhead Shrikes, American Kestrels, and Prairie Falcons were seen throughout the year. Turkey Vultures were not present during winter months, while Golden Eagles were seen only during November and December. Turkey Vultures, Red-tailed Hawks, and ravens were most numerous on agricultural lands, while Loggerhead Shrikes were most Common at urban areas. Raven numbers increased with increasing number of linear rights-of-way parallel to the survey route. Perching was the most common behavior type, although Turkey Vultures and ravens were often observed soaring, flying, or standing on the ground near highways. Transmission powerline towers and telephone poles were used as perch sites disproportionately to availability.

  13. Jojoba could stop the desert creep

    Energy Technology Data Exchange (ETDEWEB)

    1982-03-25

    The Sahara desert is estimated to be expanding at a rate of 5km a year. The Sudanese government is experimenting with jojoba in six different regions as the bush has the potential to stop this ''desert creep''. The plant, a native to Mexico, is long known for its resistance to drought and for the versatile liquid wax that can be extracted from its seeds. It is estimated that one hectare of mature plants could produce 3000 kg of oil, currently selling at $50 per litre, and so earn valuable foreign currency.

  14. Geochemical registers of Late Quaternary paleoclimatic conditions at Sonora and Chihuahua Deserts, Mexico: comparison and synthesis

    Science.gov (United States)

    Roy, P.; Perez-Cruz, L. L.; Lozano-Garcia, S.

    2011-12-01

    Sonora and Chihuahua Deserts form the southwestern and southeastern parts of North American Desert system and spread over at least 5 different states in the northern Mexico. Presently, Sonora Desert receives annual precipitation in a bi-modal distribution, whereas Chihuahua Desert receives dominant summer precipitation. Paleoclimatic registers from Mojave Desert suggest that the spatial extent and magnitude of both the summer and winter precipitation varied during the last glacial period and such fluctuations were linked to the volume of the Laurentide ice sheet, changing winter-summer insolation, North Atlantic climatic variability and ENSO dynamics. We present multi-elemental concentrations, magnetic susceptibility, organic and inorganic carbon from 750 cm long sediment core collected from paleolake San Felipe (31°N, western Sonora Desert) and 970 cm long sediment core collected from paleolake Babicora (29°N, western Chihuahua Desert) in order to understand the paleohydrological and paleoclimatic evolution in the arid region of northern Mexico. 6 AMS 14C dates constrain the San Felipe sediment core between 49 cal kyr BP and present. Similarly, 8 AMS 14C dates put the Babicora core in the age bracket between 76 cal kyr BP and present with two different hiatus at 4-8 cal kyr BP and 40-45 cal kyr BP. Due to the special geomorphology of San Felipe basin, Ti concentration was used as a proxy for pluvial discharge and to differentiate regimes of dominant summer and winter precipitation. Aeolian deposition was constrained at >48 cal kyr BP. Period of lower pluvial discharge during 14-48 cal kyr BP is related to a regime of dominant winter frontal storms. During 3-14 cal kyr BP, higher catchment erosion and transportation of REE bearing heavy minerals into the basin are possibly as a result of higher pluvial discharge related to a regime of dominant summer precipitation. In paleolake Babicora, high resolution Ti suggests higher pluvial inflow prior to 60 cal kyr BP (H

  15. USDA Southwest Regional Hub for Adaptation to and Mitigation of Climate Change

    Science.gov (United States)

    Rango, A.; Elias, E.; Steele, C. M.; Havstad, K.

    2014-12-01

    The USDA Southwest (SW) Climate Hub was created in February 2014 to develop risk adaptation and mitigation strategies for coping with climate change effects on agricultural productivity. There are seven regional hubs across the country with three subsidiary hubs. The SW Climate Hub Region is made up of six states: New Mexico, Arizona, Utah, Nevada, California and Hawaii (plus the Trust Territories of the Pacific Islands). The SW Climate Hub has a subsidiary hub located in Davis, California. The Southwest region has high climatic diversity, with the lowest and highest average annual rainfall in the U.S.(6.0 cm in Death Valley, CA and 1168 cm at Mt. Waialeale, HI). There are major deserts in five of the six states, yet most of the states, with exception of Hawaii, depend upon the melting of mountain snowpacks for their surface water supply. Additionally, many of the agricultural areas of the SW Regional Hub depend upon irrigation water to maintain productivity. Scientific climate information developed by the Hub will be used for climate-smart decision making. To do this, the SW Regional Hub will rely upon existing infrastructure of the Cooperative Extension Service at Land-Grant State Universities. Extension service and USDA-NRCS personnel have existing networks to communicate with stakeholders (farmers, ranchers, and forest landowners) through meetings and workshops which have already started in the six states. Outreach through the development of a weather and climate impact modules designed for seventh grade students and their teachers will foster education of future generations of rural land managers. We will be synthesizing and evaluating existing reports, literature and information on regional climate projections, water resources, and agricultural adaptation strategies related to climate in the Southwest. The results will be organized in a spatial format and provided through the SW Hub website (http://swclimatehub.info) and peer-reviewed articles.

  16. Gun Trafficking and the Southwest Border

    Science.gov (United States)

    2009-07-29

    Source of Narco Syndicates Rising Firepower,” Narcosphere, March 29, 2009. Gun Trafficking and the Southwest Border Congressional Research...50 years old, of museum interest, or derive a substantial amount of their value from the fact that they are novel , rare, bizarre, or because they

  17. Comparison of remote sensing indices for monitoring of desert cienegas

    Science.gov (United States)

    Wilson, Natalie R; Norman, Laura M.; Villarreal, Miguel; Gass, Leila; Tiller, Ron; Salywon, Andrew

    2016-01-01

    This research considers the applicability of different vegetation indices at 30 m resolution for mapping and monitoring desert wetland (cienega) health and spatial extent through time at Cienega Creek in southeastern Arizona, USA. Multiple stressors including the risk of decadal-scale drought, the effects of current and predicted global warming, and continued anthropogenic pressures threaten aquatic habitats in the southwest and cienegas are recognized as important sites for conservation and restoration efforts. However, cienegas present a challenge to satellite-imagery based analysis due to their small size and mixed surface cover of open water, exposed soils, and vegetation. We created time series of five well-known vegetation indices using annual Landsat Thematic Mapper (TM) images retrieved during the April–June dry season, from 1984 to 2011 to map landscape-level distribution of wetlands and monitor the temporal dynamics of individual sites. Indices included the Normalized Difference Vegetation Index (NDVI), the Soil-Adjusted Vegetation Index (SAVI), the Normalized Difference Water Index (NDWI), and the Normalized Difference Infrared Index (NDII). One topographic index, the Topographic Wetness Index (TWI), was analyzed to examine the utility of topography in mapping distribution of cienegas. Our results indicate that the NDII, calculated using Landsat TM band 5, outperforms the other indices at differentiating cienegas from riparian and upland sites, and was the best means to analyze change. As such, it offers a critical baseline for future studies that seek to extend the analysis of cienegas to other regions and time scales, and has broader applicability to the remote sensing of wetland features in arid landscapes.

  18. New Insights in Preservation of Meteorites in Hot Deserts: The Oldest Hot Desert Meteorite Collection.

    Science.gov (United States)

    Hutzler, A.; Rochette, P.; Bourlès, D.; Gattacceca, J.; Merchel, S.; Jull, A. J. T.; Valenzuela, M.

    2016-08-01

    Terrestrial ages of a subset of a chilean meteorite collection have been determined with cosmogenic nuclides. We show here that provided the environnement is favorable enough, hot desert meteorites can survive over a million year.

  19. Using motion-sensor camera technology to infer seasonal activity and thermal niche of the desert tortoise (Gopherus agassizii).

    Science.gov (United States)

    Agha, Mickey; Augustine, Benjamin; Lovich, Jeffrey E; Delaney, David; Sinervo, Barry; Murphy, Mason O; Ennen, Joshua R; Briggs, Jessica R; Cooper, Robert; Price, Steven J

    2015-01-01

    Understanding the relationships between environmental variables and wildlife activity is an important part of effective management. The desert tortoise (Gopherus agassizii), an imperiled species of arid environments in the southwest US, may have increasingly restricted windows for activity due to current warming trends. In summer 2013, we deployed 48 motion sensor cameras at the entrances of tortoise burrows to investigate the effects of temperature, sex, and day of the year on the activity of desert tortoises. Using generalized estimating equations, we found that the relative probability of activity was associated with temperature (linear and quadratic), sex, and day of the year. Sex effects showed that male tortoises are generally more active than female tortoises. Temperature had a quadratic effect, indicating that tortoise activity was heightened at a range of temperatures. In addition, we found significant support for interactions between sex and day of the year, and sex and temperature as predictors of the probability of activity. Using our models, we were able to estimate air temperatures and times (days and hours) that were associated with maximum activity during the study. Because tortoise activity is constrained by environmental conditions such as temperature, it is increasingly vital to conduct studies on how tortoises vary their activity throughout the Sonoran Desert to better understand the effects of a changing climate.

  20. Using motion-sensor camera technology to infer seasonal activity and thermal niche of the desert tortoise (Gopherus agassizii)

    Science.gov (United States)

    Agha, Mickey; Augustine, Benjamin; Lovich, Jeffrey E.; Delaney, David F.; Sinervo, Barry; Murphy, Mason O.; Ennen, Joshua R.; Briggs, Jessica R.; Cooper, Robert J.; Price, Steven J.

    2015-01-01

    Understanding the relationships between environmental variables and wildlife activity is an important part of effective management. The desert tortoise (Gopherus agassizii), an imperiled species of arid environments in the southwest US, may have increasingly restricted windows for activity due to current warming trends. In summer 2013, we deployed 48 motion sensor cameras at the entrances of tortoise burrows to investigate the effects of temperature, sex, and day of the year on the activity of desert tortoises. Using generalized estimating equations, we found that the relative probability of activity was associated with temperature (linear and quadratic), sex, and day of the year. Sex effects showed that male tortoises are generally more active than female tortoises. Temperature had a quadratic effect, indicating that tortoise activity was heightened at a range of temperatures. In addition, we found significant support for interactions between sex and day of the year, and sex and temperature as predictors of the probability of activity. Using our models, we were able to estimate air temperatures and times (days and hours) that were associated with maximum activity during the study. Because tortoise activity is constrained by environmental conditions such as temperature, it is increasingly vital to conduct studies on how tortoises vary their activity throughout the Sonoran Desert to better understand the effects of a changing climate.

  1. Reading the American Landscape. An Index of Books and Images

    NARCIS (Netherlands)

    Jong, de E.; Schreiber, H.; Sijmons, D.F.; Hoogewoning, A.

    2009-01-01

    From city high-rise to southern desert, from urban sprawl to virgin canyons, the American landscape is endless in its variety. On the initiative of the Netherlands Foundation for Visual Arts, Design and Architecture, a group of landscape architects, architects, urban designers, artists and critics t

  2. From desert to deluge in the Mediterranean

    NARCIS (Netherlands)

    McKenzie, Judith A.

    2002-01-01

    Some time between five and six million years ago, the Mediterranean Sea became isolated from the Atlantic Ocean. In consequence some areas dried out -- hence the title of Kenneth Hsü’s book The Mediterranean was a Desert 1 -- and large salty lakes recharged by rivers flowing through deep canyons rep

  3. Spectral reflectance in the Tunisian desert.

    NARCIS (Netherlands)

    Epema, G.F.

    1992-01-01

    .Satellites provide the possibility to give a synoptical view of the earth surface at regular time intervals. Satellites operating in the optical wavelengths have however as disadvantage that monitoring of the surface characteristics becomes impossible as soon as clouds are present. Deserts and dese

  4. Microflora in soils of desert regions

    Science.gov (United States)

    Cameron, R. E.

    1970-01-01

    Desert soil samples, collected using aseptic techniques, are low in organic matter and cation exchange capacity. Aerobic and microaerophilic bacteria are most abundant, next are algae and molds. Chemical and physical properties are determined by standard procedures, including the Kjeldahl method and the use of Munsell soil color charts.

  5. Habitat selection by juvenile Mojave Desert tortoises

    Science.gov (United States)

    Todd, Brian D; Halstead, Brian J.; Chiquoine, Lindsay P.; Peaden, J. Mark; Buhlmann, Kurt A.; Tuberville, Tracey D.; Nafus, Melia G.

    2016-01-01

    Growing pressure to develop public lands for renewable energy production places several protected species at increased risk of habitat loss. One example is the Mojave desert tortoise (Gopherus agassizii), a species often at the center of conflicts over public land development. For this species and others on public lands, a better understanding of their habitat needs can help minimize negative impacts and facilitate protection or restoration of habitat. We used radio-telemetry to track 46 neonate and juvenile tortoises in the Eastern Mojave Desert, California, USA, to quantify habitat at tortoise locations and paired random points to assess habitat selection. Tortoise locations near burrows were more likely to be under canopy cover and had greater coverage of perennial plants (especially creosote [Larrea tridentata]), more coverage by washes, a greater number of small-mammal burrows, and fewer white bursage (Ambrosia dumosa) than random points. Active tortoise locations away from burrows were closer to washes and perennial plants than were random points. Our results can help planners locate juvenile tortoises and avoid impacts to habitat critical for this life stage. Additionally, our results provide targets for habitat protection and restoration and suggest that diverse and abundant small-mammal populations and the availability of creosote bush are vital for juvenile desert tortoises in the Eastern Mojave Desert.

  6. Southwest Regional Partnership on Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Brian McPherson

    2006-03-31

    The Southwest Partnership on Carbon Sequestration completed its Phase I program in December 2005. The main objective of the Southwest Partnership Phase I project was to evaluate and demonstrate the means for achieving an 18% reduction in carbon intensity by 2012. Many other goals were accomplished on the way to this objective, including (1) analysis of CO{sub 2} storage options in the region, including characterization of storage capacities and transportation options, (2) analysis and summary of CO{sub 2} sources, (3) analysis and summary of CO{sub 2} separation and capture technologies employed in the region, (4) evaluation and ranking of the most appropriate sequestration technologies for capture and storage of CO{sub 2} in the Southwest Region, (5) dissemination of existing regulatory/permitting requirements, and (6) assessing and initiating public knowledge and acceptance of possible sequestration approaches. Results of the Southwest Partnership's Phase I evaluation suggested that the most convenient and practical ''first opportunities'' for sequestration would lie along existing CO{sub 2} pipelines in the region. Action plans for six Phase II validation tests in the region were developed, with a portfolio that includes four geologic pilot tests distributed among Utah, New Mexico, and Texas. The Partnership will also conduct a regional terrestrial sequestration pilot program focusing on improved terrestrial MMV methods and reporting approaches specific for the Southwest region. The sixth and final validation test consists of a local-scale terrestrial pilot involving restoration of riparian lands for sequestration purposes. The validation test will use desalinated waters produced from one of the geologic pilot tests. The Southwest Regional Partnership comprises a large, diverse group of expert organizations and individuals specializing in carbon sequestration science and engineering, as well as public policy and outreach. These partners

  7. Palynology of Albian-Cenomanian strata in Mersa Matruh well, Western Desert, Egypt

    Science.gov (United States)

    Sultan, Ismail Z.

    Plant microfossils have been recovered from the Albian and lower Cenomanian strata encountered in Mersa Matruh well No. 1, drilled in the northern part of the Western Desert of Egypt. The microflora includes 56 miospore species belonging to 35 genera; most of them are derived from pteridophyte, gymnosperm and angiosperm vegetations. Differences in miospore assemblages of the Albian and Lower Cenomanian are described. Correlation with coeval palynofloral assemblages in West Africa and South and North America reveals that the Mersa Matruh area, Egypt belongs to the mid-Cretaceous African-South American phytogeoprovince.

  8. Remote sensing of Sonoran Desert vegetation structure and phenology with ground-based LiDAR

    Science.gov (United States)

    Sankey, Joel B.; Munson, Seth M.; Webb, Robert H.; Wallace, Cynthia S.A.; Duran, Cesar M.

    2015-01-01

    Long-term vegetation monitoring efforts have become increasingly important for understanding ecosystem response to global change. Many traditional methods for monitoring can be infrequent and limited in scope. Ground-based LiDAR is one remote sensing method that offers a clear advancement to monitor vegetation dynamics at high spatial and temporal resolution. We determined the effectiveness of LiDAR to detect intra-annual variability in vegetation structure at a long-term Sonoran Desert monitoring plot dominated by cacti, deciduous and evergreen shrubs. Monthly repeat LiDAR scans of perennial plant canopies over the course of one year had high precision. LiDAR measurements of canopy height and area were accurate with respect to total station survey measurements of individual plants. We found an increase in the number of LiDAR vegetation returns following the wet North American Monsoon season. This intra-annual variability in vegetation structure detected by LiDAR was attributable to a drought deciduous shrub Ambrosia deltoidea, whereas the evergreen shrub Larrea tridentata and cactus Opuntia engelmannii had low variability. Benefits of using LiDAR over traditional methods to census desert plants are more rapid, consistent, and cost-effective data acquisition in a high-resolution, 3-dimensional context. We conclude that repeat LiDAR measurements can be an effective method for documenting ecosystem response to desert climatology and drought over short time intervals and at detailed-local spatial scale.

  9. The New Life--La Vida Neuva: The Mexican Americans Today.

    Science.gov (United States)

    Dobrin, Arnold

    Emphasizing present-day Chicanos, this book relates the "new life" of Mexican Americans throughout the United States but with particular reference to the Southwest. A view of Mexican American communities and their peoples' feelings about prejudice, education, and politics is presented. The book contains narrative sketches on individuals involved…

  10. Critical Contexts for Biomedical Research in a Native American Community: Health Care, History, and Community Survival

    Science.gov (United States)

    Sahota, Puneet Chawla

    2012-01-01

    Native Americans have been underrepresented in previous studies of biomedical research participants. This paper reports a qualitative interview study of Native Americans' perspectives on biomedical research. In-depth interviews were conducted with 53 members of a Southwest tribal community. Many interviewees viewed biomedical research studies as a…

  11. A Review of Child Psychiatric Epidemiology With Special Reference to American Indian and Alaska Native Children.

    Science.gov (United States)

    Green, Ben Ezra; And Others

    1981-01-01

    Places the limited knowledge of the psychological problems of American Indian and Alaska Native children in context of general child psychiatric epidemiology, using the taxonomy of the American Psychiatric Association's third "Diagnostic and Statistical Manual." Available from: White Cloud Center, Gaines Hall UOHSC, 840 Southwest Gaines…

  12. Snow, the Great River, and the Desert

    Science.gov (United States)

    Rango, A.

    2005-12-01

    While many major rivers around the world originate from alpine snowpacks in mountain regions, some experience the extreme contrast of flowing through harsh desert environments downriver. One such stream is the Rio Grande which rises in the San Juan and the Sangre de Christo mountains of southern Colorado and northern New Mexico. Eventually, the snow fed Rio Grande flows through North America's largest desert, the Chihuahuan Desert in New Mexico, Texas, and Mexico, and simultaneously becomes part of the border between the United States and Mexico. As is often true, urban areas develop along the river corridors rather than in more inaccessible mountain regions. This demographic preference tends to isolate the vast majority of population in the Rio Grande, who are dependent on water for their livelihoods, from the mountain snowpacks where the flow is generated. Ironically then, snow is seldom viewed as the source of the much needed water flowing through the desert by the majority of the basin's population. In arid regions of the western U.S., water demand far exceeds the water supply, and water use is apportioned under the doctrine of prior appropriation with the oldest right getting the first use of water. The increasing population in urban areas does not usually have a right to use the water flowing through the desert unless water rights have been purchased by municipalities from the major category of water user in these basins, namely, irrigated agriculture. In the entire Rio Grande basin, irrigation makes up 80% of the consumptive use of water. Additionally, basin compacts and international treaties apportion water between states and countries. Because these formal agreements were based on above average runoff years, there is little flexibility in changing the use of water, particularly in dry to normal runoff years. Most of the older water rights in the Rio Grande, especially the upper basin, are supplied by snowmelt. This leaves the lower basin to depend upon

  13. SOUTHWEST REGIONAL PARTNERSHIP FOR CARBON SEQUESTRATION

    Energy Technology Data Exchange (ETDEWEB)

    Brian McPherson

    2004-04-01

    The Southwest Partnership Region includes five states (Arizona, Colorado, New Mexico, Oklahoma, Utah) and contiguous areas from three adjacent states (west Texas, south Wyoming, and west Kansas). This energy-rich region exhibits some of the largest growth rates in the nation, and it contains two major CO{sub 2} pipeline networks that presently tap natural subsurface CO{sub 2} reservoirs for enhanced oil recovery at a rate of 30 million tons per year. The ten largest coal-fired power plants in the region produce 50% (140 million tons CO{sub 2}/y) of the total CO{sub 2} from power-plant fossil fuel combustion, with power plant emissions close to half the total CO{sub 2} emissions. The Southwest Regional Partnership comprises a large, diverse group of expert organizations and individuals specializing in carbon sequestration science and engineering, as well as public policy and outreach. These partners include 21 state government agencies and universities, the five major electric utility industries, seven oil, gas and coal companies, three federal agencies, the Navajo Nation, several NGOs including the Western Governors Association, and data sharing agreements with four other surrounding states. The Partnership is developing action plans for possible Phase II carbon sequestration pilot tests in the region, as well as the non-technical aspects necessary for developing and carrying out these pilot tests. The establishment of a website network to facilitate data storage and information sharing, decision-making, and future management of carbon sequestration in the region is a priority. The Southwest Partnership's approach includes (1) dissemination of existing regulatory/permitting requirements, (2) assessing and initiating public acceptance of possible sequestration approaches, and (3) evaluation and ranking of the most appropriate sequestration technologies for capture and storage of CO{sub 2} in the Southwest Region. The Partnership will also identify potential

  14. The Impacts of Chihuahua Desert Aerosol Intrusions on Convective Clouds and Regional Precipitation

    Science.gov (United States)

    Apodaca, Karina

    Growing up in a desert region influenced by a monsoon system and experiencing, first-hand, dust storms produced by convective thunderstorms stimulated my interest in the study of the impacts of aerosols on clouds. Contrary to other studies which focus more on anthropogenic aerosols, I chose to investigate the role of natural aerosols in the deserts of North America. Moreover, the role played by aerosols in desert regions within the North American Monsoon domain has not received as much attention as in other monsoon regions around the world. This dissertation describes my investigation of the connection between mineral aerosols (dust storms) and monsoon rainfall in the deserts of the Southwestern United States and Northwestern Mexico. To develop the context for the study of the role of mineral dust in summer-time convection on a regional scale, large-scale dynamical processes and their impact on the inter-annual variability of monsoon rainfall were analyzed. I developed the climatology of monsoonal rainfall and dust storms using surface observations to determine which mesoscale features influence North American Monsoon rainfall in the Paso Del Norte region. The strongest correlations were found between sea surface temperatures over the Gulf of California, Gulf of California moisture surges and monsoon rainfall in the Paso Del Norte region. A connection to ENSO could not be clearly established despite analyzing twenty-one years of data. However, by breaking the data into segments, a strong correlation was found for periods of intense rainfall. Twenty-one case studies were identified in which dust storms were produced in conjunction with thunderstorms during the 2005 - 2007 monsoon seasons. However, in some cases all the conditions were there for rainfall to occur but it did not precipitate. I concluded that strong thunderstorm outflow was triggering dust storms. The Weather Research and Forecasting model coupled with Chemistry (WRF-Chem V3.1.1) was used to evaluate

  15. High performance robotic traverse of desert terrain.

    Energy Technology Data Exchange (ETDEWEB)

    Whittaker, William (Carnegie Mellon University, Pittsburgh, PA)

    2004-09-01

    This report presents tentative innovations to enable unmanned vehicle guidance for a class of off-road traverse at sustained speeds greater than 30 miles per hour. Analyses and field trials suggest that even greater navigation speeds might be achieved. The performance calls for innovation in mapping, perception, planning and inertial-referenced stabilization of components, hosted aboard capable locomotion. The innovations are motivated by the challenge of autonomous ground vehicle traverse of 250 miles of desert terrain in less than 10 hours, averaging 30 miles per hour. GPS coverage is assumed to be available with localized blackouts. Terrain and vegetation are assumed to be akin to that of the Mojave Desert. This terrain is interlaced with networks of unimproved roads and trails, which are a key to achieving the high performance mapping, planning and navigation that is presented here.

  16. Introduction and domestication of woody plants for sustainable agriculture in desert areas

    Science.gov (United States)

    Shelef, Oren; Soloway, Elaine; Rachmilevitch, Shimon

    2014-05-01

    High radiation in hot deserts results in high salinity, especially in irrigated fields. Whenever not treated properly, this salinization may harm crops and eventually bring to soil destruction, field abandonment, or literally desertification. Furthermore, the range of crops that can be grown commercially in hot deserts is limited (Nerd et al. 1990). With the globalization of the last century, Introduction of exotic species for commercial use became more accessible. However, these attempts may involve extreme land changes including establishment of potential invasive species. Therefore domestication of native species should be preferred rather than introduction of exotics. In the last six years we did first steps of domesticating several native species, searching for commercial potential (pharmaceutics, food, biomass for energy and desalination of constructed wetlands). We studied aspects of desert plant physiology in drought and saline conditions. We wish to share the knowledge we gained regarding the physiology and commercial potential of the following desert plant species: 1) Bassia indica is an annual halophyte. We proposed to use it for salt phytoremediation in constructed wetlands for wastewater treatment and as feed for livestock; 2) Commiphora gileadensis is considered as the balm tree of Judea, praised for its use as holy oil and in perfumes but also considered as a cure for many diseases. C. gileadensis today grows naturally in southwest Arabia and Somaliland. We found anti-proliferative and apoptotic effect of C. gileadensis extracts on several human cancer cells. Ben Gurion University of the Negev has patented these findings. 3) Artemisia sieberi and A. judaica are both known for various therapeutic traits. While studying effects of irrigation intensity on these traits, some allopathic characters were discovered. 4) Fichus palmate disappeared from Israel, but remind in neighbouring Jordan and Egypt. This tree may serve as a robust stand for fig

  17. Regional signatures of plant response to drought and elevated temperature across a desert ecosystem.

    Science.gov (United States)

    Munson, Seth M; Muldavin, Esteban H; Belnap, Jayne; Peters, Debra P C; Anderson, John P; Reiser, M Hildegard; Gallo, Kirsten; Melgoza-Castillo, Alicia; Herrick, Jeffrey E; Christiansen, Tim A

    2013-09-01

    The performance of many desert plant species in North America may decline with the warmer and drier conditions predicted by climate change models, thereby accelerating land degradation and reducing ecosystem productivity. We paired repeat measurements of plant canopy cover with climate at multiple sites across the Chihuahuan Desert over the last century to determine which plant species and functional types may be the most sensitive to climate change. We found that the dominant perennial grass, Bouteloua eriopoda, and species richness had nonlinear responses to summer precipitation, decreasing more in dry summers than increasing with wet summers. Dominant shrub species responded differently to the seasonality of precipitation and drought, but winter precipitation best explained changes in the cover of woody vegetation in upland grasslands and may contribute to woody-plant encroachment that is widespread throughout the southwestern United States and northern Mexico. Temperature explained additional variability of changes in cover of dominant and subdominant plant species. Using a novel empirically based approach we identified "climate pivot points" that were indicative of shifts from increasing to decreasing plant cover over a range of climatic conditions. Reductions in cover of annual and several perennial plant species, in addition to declines in species richness below the long-term summer precipitation mean across plant communities, indicate a decrease in the productivity for all but the most drought-tolerant perennial grasses and shrubs in the Chihuahuan Desert. Overall, our regional synthesis of long-term data provides a robust foundation for forecasting future shifts in the composition and structure of plant assemblages in the largest North American warm desert.

  18. Modeling the shrub encroachment in the Northern Chihuahuan desert Grasslands using a Cellular Automata model

    Science.gov (United States)

    Caracciolo, Domenico; Istanbulluoglu, Erkan; Noto, Leonardo V.

    2014-05-01

    Arid grasslands of southwestern North America have changed dramatically over the last 150 years as a result of the shrub encroachment, i.e. the increase in density and biomass of indigenous shrubby plants in grasslands. Numerous studies have documented the expansion of shrublands in the southwestern America Grasslands; in particular the encroachment of shrubs in american deserts has strongly occurred in the Chihuahuan deserts from 1860. The Sevilleta National Wildlife Refuge (SNWR), located in the northern Chihuahuan desert shows a dramatic encroachment front of creosote bush (i.e., shrub) into native desert grassland. This encroachment has been here simulated using an Ecohydrological Cellular Automata Model, CATGraSS. CATGraSS is a spatially distributed model driven by spatially explicit irradiance and runs on a fine-resolution gridded domain. In the model, each cell can hold a single plant type or can represent bare soil. Plant competition is modeled by keeping track of mortality and establishment of plants, both calculated probabilistically based on soil moisture stress. For this study, the model is improved with a stochastic fire and a grazing function, and its plant establishment algorithm is modified. CATGraSS is implemented in a small area (7.3 km2) in SNWR, characterized by two vegetation types: grass savanna and creosote bush. The causes that have been considered for the encroachment in this case study are: the fire return period increase, the grazing increase, the seed dispersal caused by animals, the role of wind direction and the shrub-grass inhibition effect. The model is able to reproduce the encroachment occurred in the SNWR basin, simulating an increasing of the shrub from 2% in 1860 to 42% (i.e., current shrub percentage) in 2010 highlighting as more influent factors the reduced fire frequency and the increased grazing intensity. For the future management and encroachment control, the reduction of the fire return period and the grazing removal

  19. Himalayan Mountain Range, Taklimakan Desert, China

    Science.gov (United States)

    1991-01-01

    Looking north from Kashmir India (27.5N, 76.5E) into the Tibetan Plateau and beyond, the Taklimakan Desert of far western China appears to be covered with an extensive layer of haze that blankets the entire region. Reaching even into the western Siberian Plains of the CIS. This rugged land is one of the world's richest treasure troves of mineral wealth but the accessability into this remote area is so difficult that it is not yet economically feasible.

  20. Expansion and contraction of Chinese deserts during the Quaternary

    Institute of Scientific and Technical Information of China (English)

    刘东生; 孙继敏

    2002-01-01

    Episodic dune formations during the Quaternary are found in many deserts of China.The causes of desert expansions on different time scales are not the same. Desert extension atabout 1.1 and 0.9 Ma ago were the response to the active tectonic movements, whereas the de-sert evolutions on the ten-thousand years time scale were the response to the orbital scale climaticchanges. Spatial scale studies on desert evolution indicate that desert margins shifted greatly dur-ing the last glacial maximum (LGM) and the Holocene optimum, its changing from 125°E of theLGM to 105°E of the climatic optimum. Historical desertification in the semiarid China is not a re-sponse to climate drought but largely associated with the human impacts (mainly over-cultivation)since about 2300 years ago, which leads to the reworking of the underlying LGM sands.

  1. The Palm Desert renewable [hydrogen] transportation system

    Energy Technology Data Exchange (ETDEWEB)

    Chamberlin, C.E.; Lehman, P. [Humboldt State Univ., Arcata, CA (United States). Schatz Energy Research Center

    1998-08-01

    This paper describes the Schatz Energy Research Center (SERC) progress on the Palm Desert Renewable Hydrogen Transportation System Project for the period June 1997 through May 1998. The project began in March 1996. The goal of the Palm Desert Project is to develop a clean and sustainable transportation system for a community. The project demonstrates the practical utility of hydrogen as a transportation fuel and the proton exchange membrane (PEM) fuel cell as a vehicle power system. The project includes designing and building 4 fuel cell powered vehicles, a solar hydrogen generating and refueling station, and a fuel cell vehicle diagnostic center. Over this last year, SERC has built a fuel cell powered neighborhood electric vehicle and delivered it to the City of Palm Desert. The design of the hydrogen refueling station is near completion and it is anticipated that construction will be complete in the fall of 1998. The vehicles are currently being refueled at a temporary refueling station. The diagnostic center is being designed and maintenance procedures as well as computer diagnostic programs for the fuel cell vehicles are being developed. City employees are driving the vehicles daily and monitoring data are being collected. The drivers are pleased with the performance of the vehicles.

  2. Adsorption of dyes on Sahara desert sand.

    Science.gov (United States)

    Varlikli, Canan; Bekiari, Vlasoula; Kus, Mahmut; Boduroglu, Numan; Oner, Ilker; Lianos, Panagiotis; Lyberatos, Gerasimos; Icli, Siddik

    2009-10-15

    Sahara desert sand (SaDeS) was employed as a mineral sorbent for retaining organic dyes from aqueous solutions. Natural sand has demonstrated a strong affinity for organic dyes but significantly lost its adsorption capacity when it was washed with water. Therefore, characterization of both natural and water washed sand was performed by XRD, BET, SEM and FTIR techniques. It was found that water-soluble kyanite, which is detected in natural sand, is the dominant factor affecting adsorbance of cationic dyes. The sand adsorbs over 75% of cationic dyes but less than 21% for anionic ones. Among the dyes studied, Methylene Blue (MB) demonstrated the strongest affinity for Sahara desert sand (Q(e)=11.98 mg/g, for initial dye solution concentration 3.5 x 10(-5)mol/L). The effects of initial dye concentration, the amount of the adsorbent, the temperature and the pH of the solution on adsorption capacity were tested by using Methylene Blue as model dye. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models were applied. It was concluded that adsorption of Methylene Blue on Sahara desert sand followed pseudo-second order kinetics. Gibbs free energy, enthalpy change and entropy change were calculated and found -6411 J/mol, -30360 J/mol and -76.58 J/mol K, respectively. These values indicate that the adsorption is an exothermic process and has a spontaneous nature at low temperatures.

  3. CAMEL REARING IN CHOLISTAN DESERT OF PAKISTAN

    Directory of Open Access Journals (Sweden)

    I. ALI, M. SHAFIQ CHAUDHRY1 AND U. FAROOQ

    2009-05-01

    Full Text Available The camel is one of the typical and the best adopted animals of the desert, capable of enduring thirst and hunger for days and is the most patient of land animals. For desert nomads of Pakistani Cholistan, it is a beloved companion, a source of milk and meat, transport facility provider and a racing/dancing animal, thus, playing an important role in the socioeconomic uplift of the local community. Camels of Marrecha or Mahra breed are mainly used for riding and load carrying but may be trained for dancing or racing. Berella is another heavy and milch breed of camel famous for milk production and can produce upto 10-15 liters of milk per day. This breed is also suitable for draught purpose, though comparatively slow due to heavy body. The present paper also describes the traditional camel rearing system used by nomads of Cholistan desert. Some aspects of camel health, production, feeding, socio-economic values, marketing and some constraints and suggestions are also given so that the policy makers may consider them for the welfare of this animal.

  4. Breeding biology and nest-site selection of red-tailed hawks in an altered desert grassland

    Science.gov (United States)

    Hobbs, R.J.; DeStefano, S.; Halvorson, W.L.

    2006-01-01

    Red-tailed Hawks (Buteo jamaicensis) have expanded their range as trees have invaded formerly-open grasslands. Desert grasslands of southern Arizona have been invaded by mesquite trees (Prosopis velutina) since Anglo-American settlement and now support a large population of Red-tailed Hawks. We studied a population of Red-tailed Hawks in an altered desert grassland in southern Arizona. Our objectives were to determine what environmental characteristics influence Red-tailed Hawk habitat selection in mesquite-invaded desert grasslands and to evaluate the habitat quality of these grasslands for Red-tailed Hawks based on nesting density, nest success, and productivity. Red-tailed Hawks had 86% (95% C.I. = 73-99) nest success and 1.82 young per breeding pair (95% C.I. = 1.41-2.23). Nesting density was 0.15 (95% CI = 0.08-0.21) breeding pairs/km2 and the mean nearest-neighbor distance was 1.95 km (95% C.I. = 1.74-2.16). Red-tailed Hawks selected nest-sites with taller nest-trees and greater tree height and cover than were available at random. Mesquite trees in desert grasslands provide abundant potential nesting structures for Red-tailed Hawks. ?? 2006 The Raptor Research Foundation, Inc.

  5. Neogene climate change and uplift in the Atacama Desert, Chile

    Science.gov (United States)

    Rech, Jason A.; Currie, Brian S.; Michalski, Greg; Cowan, Angela M.

    2006-09-01

    The relationship between Andean uplift and extreme desiccation of the west coast of South America is important for understanding the interplay between climate and tectonics in the Central Andes, yet it is poorly understood. Here we use soil morphological characteristics, salt chemistry, and mass independent fractionation anomalies (Δ17O values) in dated paleosols to reconstruct a middle Miocene climatic transition from semiaridity to extreme hyperaridity in the Atacama Desert. Paleosols along the southeastern margin of the Calama Basin change from calcic Vertisols with root traces, slickensides, and gleyed horizons to an extremely mature salic Gypsisol with pedogenic nitrate. We interpret this transition, which occurred between 19 and 13 Ma, to represent a change in precipitation from >200 mm/yr to 2 km; the uplift blocked moisture from the South American summer monsoon from entering the Atacama. The mid-Miocene Gypsisol with pedogenic nitrate is located at elevations between 2900 and 3400 m in the Calama Basin, significantly higher than modern nitrate soils, which occur below ˜2500 m. Modern and Quaternary soils in this elevation zone contain soil carbonate and lack pedogenic gypsum and nitrate. We infer that >900 m of local surface uplift over the past 10 m.y. displaced these nitrate paleosols relative to modern nitrate soils and caused a return to wetter conditions in the Calama Basin by decreasing local air temperatures and creating an orographic barrier to Pacific air masses.

  6. Aerosol direct radiative forcing in desert and semi-desert regions of northwestern China

    Science.gov (United States)

    Xin, Jinyuan; Gong, Chongshui; Wang, Shigong; Wang, Yuesi

    2016-05-01

    The optical properties of dust aerosols were measured using narrow-band data from a portable sun photometer at four desert and semi-desert stations in northwestern China from 2004 to 2007. Ground-based and satellite observations indicated absorbing dust aerosol loading over the region surrounded by eight large-scale deserts. Radiation forcing was identified by using the Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model. The ranges of annual mean aerosol optical depth (AOD), Angström exponents, and single-scattering albedo (SSA) were from 0.25 to 0.35, from - 0.73 to 1.18, and from 0.77 to 0.86, respectively. The ranges of annual mean aerosol direct radiative forcing values at the top of the atmosphere (TOA), mid-atmosphere, and on the surface were from 3.9 to 12.0, from 50.0 to 53.1, and from - 39.1 to - 48.1 W/m2, respectively. The aerosols' optical properties and radiative characteristics showed strong seasonal variations in both the desert and semi-desert regions. Strong winds and relatively low humidity will lead dust aerosols in the atmosphere to an increase, which played greatly affected these optical properties during spring and winter in northwestern China. Based on long-term observations and retrieved data, aerosol direct radiative forcing was confirmed to heat the atmosphere (50-53 W/m2) and cool the surface (- 39 to - 48 W/m2) above the analyzed desert. Radiative forcing in the atmosphere in spring and winter was 18 to 21 W/m2 higher than other two seasons. Based on the dust sources around the sites, the greater the AOD, the more negative the forcing. The annual averaged heating rates for aerosols close to the ground (1 km) were approximately 0.80-0.85 K/day.

  7. The Use of Water During the Crew 144, Mars Desert Research Station, Utah Desert

    Science.gov (United States)

    De Morais Mendonca Teles, Antonio

    2016-07-01

    Well. from November 29th to December 14th, 2014, the author conducted astrobiological and geological surveys, as analog astronaut member of the international Crew 144, at the site of the Mars Society's Mars Desert Research Station, located at a remote location in the Utah desert, United States. The use of water for drinking, bathing, cleaning, etc., in the crew was a major issue for consideration for a human expedition to the planet Mars in the future. The author would like to tell about the factors of the rationalized use of water.

  8. Gender Identity, Ethnicity, Acculturation, and Drug Use: Exploring Differences among Adolescents in the Southwest.

    Science.gov (United States)

    Kulis, Stephen; Marsiglia, Flavio Francisco; Hurdle, Donna

    2003-03-01

    This article presents the findings of a survey completed by 1351 predominantly Mexican American middle school students residing in a large urban center in the U.S. Southwest. The study explores possible associations between drug use attitudes and behaviors and gender (biological sex), gender identity, ethnicity, and acculturation status. Based on the concepts of "machismo" and "marianismo" that have been used to describe Mexican populations, four dimensions of gender identity were measured: aggressive masculinity, assertive masculinity, affective femininity, and submissive femininity. In explaining a variety of indicators of drug use behaviors and anti-drug norms, gender alone had limited explanatory power, while gender identity-often regardless of gender-was a better predictor. Aggressive masculinity was generally associated with higher risk of drug use, while the other three gender identity measures had selected protective effects. However, the impact of gender identity was strongly mediated by acculturation. Less acculturated Mexican American students reported lower aggressive masculinity scores than non-Latinos. Less acculturated Mexican American girls reported both the lowest aggressive masculinity scores and the highest submissive femininity scores. More acculturated Mexican American students, along with the less acculturated Mexican American boys, did not appear to be following a polarized approach to gender identity (machismo and marianismo) as was expected. The findings suggest that some aspects of culturally prescribed gender roles can have a protective effect against drug use behaviors and attitudes, possibly for both girls and boys.

  9. 2012 Southwest Florida Water Management District (SWFWMD) Lidar: Lake Manatee

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Geographic Information System (GIS). Southwest Florida Water Management District (SWFWMD) regularly uses digital topographic information to support regulatory, land...

  10. American Indian and Alaska native aboriginal use of alcohol in the United States.

    Science.gov (United States)

    Abbott, P J

    1996-01-01

    Alcohol beverages prior to White contact originated with the Mayan and the Aztec Nations and spread to the American Indians of the Southwest. Surprisingly, there are a number of accounts of alcohol use among other American Indians and Alaska Natives. Beverages were limited to wine and beer, and included: balche, pulque, and "haren a pitahaya" wines, tulpi beer and other beverages. White contact brought dramatic shifts in the use and function of alcoholic beverages in American Indian and Alaska Native societies.

  11. The Palm Desert Renewable Hydrogen Transportation System

    Energy Technology Data Exchange (ETDEWEB)

    Lehman, P. [Humboldt State Univ., Arcata, CA (United States)

    1996-10-01

    The present paper describes, for purposes of the Department of Energy (DoE) Hydrogen Program Review, Schatz Energy Research Center (SERC) progress on the Palm Desert Renewable Hydrogen Transportation System Project for the period January through June 1996. This period represents the first six months of the three year project. The estimated cost over three years is $3.9M, $1.859M of which is funded by the DoE ($600 k for fiscal year 1996). The goal of the Palm Desert Project is to develop a clean and sustainable transportation system for a community. The project will demonstrate the practical utility of hydrogen as a transportation fuel and proton exchange membrane (PEM) fuel cells as vehicle power plants. This transportation system will be developed in the City of Palm Desert in southern California and will include a fleet of 8 fuel cell powered vehicles, solar and wind powered hydrogen generating facilities, a consumer-ready refueling station, and a service infrastructure. The system holds the promise of a clean environment and an energy supply that is predictable, domestic, safe, and abundant. During, the first part of 1996 SERC has nearly completed building a fuel cell powered personal utility vehicle, which features an upgraded safety and computer system; they have designed and built a test bench that is able to mimic golf cart loads and test fuel cell system auxiliary components; they have begun the design of the solar hydrogen generating station; they have worked with Sandia National Laboratory on an advanced metal hydride storage system; they have increased the power density of the SERC fuel cell by as much as 50%; and they have reached out to the rest of the world with a new fact sheet, world wide web pages, a press release, video footage for a television program. and instruction within the community.

  12. Physiological conjunction of allelochemicals and desert plants.

    Directory of Open Access Journals (Sweden)

    Avital Yosef Friedjung

    Full Text Available Plants exchange signals with other physical and biological entities in their habitat, a form of communication termed allelopathy. The underlying principles of allelopathy and secondary-metabolite production are still poorly understood, especially in desert plants. The coordination and role of secondary metabolites were examined as a cause of allelopathy in plants thriving under arid and semiarid soil conditions. Desert plant species, Origanum dayi, Artemisia sieberi and Artemisia judaica from two different sources (cultivar cuttings and wild seeds were studied in their natural habitats. Growth rate, relative water content, osmotic potential, photochemical efficiency, volatile composition and vital factors of allelopathy were analyzed at regular intervals along four seasons with winter showing optimum soil water content and summer showing water deficit conditions. A comprehensive analysis of the volatile composition of the leaves, ambient air and soil in the biological niche of the plants under study was carried out to determine the effects of soil water conditions and sample plants on the surrounding flora. Significant morpho-physiological changes were observed across the seasons and along different soil water content. Metabolic analysis showed that water deficit was the key for driving selective metabolomic shifts. A. judaica showed the least metabolic shifts, while A. sieberi showed the highest shifts. All the species exhibited high allelopathic effects; A. judaica displayed relatively higher growth-inhibition effects, while O. dayi showed comparatively higher germination-inhibition effects in germination assays. The current study may help in understanding plant behavior, mechanisms underlying secondary-metabolite production in water deficit conditions and metabolite-physiological interrelationship with allelopathy in desert plants, and can help cull economic benefits from the produced volatiles.

  13. Physiological conjunction of allelochemicals and desert plants.

    Science.gov (United States)

    Yosef Friedjung, Avital; Choudhary, Sikander Pal; Dudai, Nativ; Rachmilevitch, Shimon

    2013-01-01

    Plants exchange signals with other physical and biological entities in their habitat, a form of communication termed allelopathy. The underlying principles of allelopathy and secondary-metabolite production are still poorly understood, especially in desert plants. The coordination and role of secondary metabolites were examined as a cause of allelopathy in plants thriving under arid and semiarid soil conditions. Desert plant species, Origanum dayi, Artemisia sieberi and Artemisia judaica from two different sources (cultivar cuttings and wild seeds) were studied in their natural habitats. Growth rate, relative water content, osmotic potential, photochemical efficiency, volatile composition and vital factors of allelopathy were analyzed at regular intervals along four seasons with winter showing optimum soil water content and summer showing water deficit conditions. A comprehensive analysis of the volatile composition of the leaves, ambient air and soil in the biological niche of the plants under study was carried out to determine the effects of soil water conditions and sample plants on the surrounding flora. Significant morpho-physiological changes were observed across the seasons and along different soil water content. Metabolic analysis showed that water deficit was the key for driving selective metabolomic shifts. A. judaica showed the least metabolic shifts, while A. sieberi showed the highest shifts. All the species exhibited high allelopathic effects; A. judaica displayed relatively higher growth-inhibition effects, while O. dayi showed comparatively higher germination-inhibition effects in germination assays. The current study may help in understanding plant behavior, mechanisms underlying secondary-metabolite production in water deficit conditions and metabolite-physiological interrelationship with allelopathy in desert plants, and can help cull economic benefits from the produced volatiles.

  14. The Desert and the Sown Project in Northern Jordan

    DEFF Research Database (Denmark)

    Kerner, Susanne

    2014-01-01

    The desert and sown project, which started in 1999 and continued in 2008-2009, studied the region between the settled areas east of Irbid and Ramtha and the surrounding desert at Mafraq (northern Jordan). Large parts of the material comes from the Palaeolithic period, while some smaller tells date...

  15. From desert to deluge in the Mediterranean

    OpenAIRE

    McKenzie, Judith A.

    2002-01-01

    Some time between five and six million years ago, the Mediterranean Sea became isolated from the Atlantic Ocean. In consequence some areas dried out -- hence the title of Kenneth Hsü’s book The Mediterranean was a Desert 1 -- and large salty lakes recharged by rivers flowing through deep canyons replaced the previously marine basins. During this time, the remaining bodies of water were either too salty or not salty enough for normal marine fauna to flourish. This was the so-called Messinian s...

  16. Morphodynamics of Planetary Deserts: A Laboratory Approach

    Science.gov (United States)

    Garcia, A.; Courrech Du Pont, S.; Rodriguez, S.

    2014-12-01

    Earth deserts show a rich variety of dune shapes from transverse to barchan, star and linear dunes depending on the history of wind regimes (strength and variability) and sand availability [1]. In desert, exposed to one wind direction, dunes perpendicular to the wind direction are found to be transverse or barchans, only sand availability plays a key role on their formation and evolution. However, the evolution time scale of such structures (several years) limits our investigation of their morphodynamics understanding. We use here, a laboratory experiment able to considerably reduce space and time scales by reproducing millimeter to centimeter subaqueous dunes by controlling environmental parameters such as type of wind (multi-winds, bimodal, quasi-bimodal or unidirectional wind) and amount of sediment [2,3]. This set up allows us to characterize more precisely the different modes of dune formation and long-term evolution, and to constrain the physics behind the morphogenesis and dynamics of dunes. Indeed, the formation, evolution and transition between the different dune modes are better understood and quantified thanks to a new setting experiment able to give a remote sediment source in continuous (closer to what happens in terrestrial desert): a sand distributor that controls the input sand flow. Firstly, in a one wind direction conditions, we managed to follow and quantify the growth of the instability of transverse dunes that break into barchans when the sand supply is low and reversely when the sand supply is higher, barchan fields evolve to bars dunes ending to form transverse. The next step will be to perform experiments under two winds conditions in order to better constrain the formation mode of linear dunes, depending also only on the input sand flux. Previous experiments shown that linear "finger" dunes can be triggered by the break of transverse dunes and then the elongating of one barchan's arm [4]. These studies can farther explain more precisely in

  17. 7 CFR 1126.2 - Southwest marketing area.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Southwest marketing area. 1126.2 Section 1126.2 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Milk), DEPARTMENT OF AGRICULTURE MILK IN THE SOUTHWEST MARKETING AREA Order...

  18. An Analysis of the Vocabulary in Southwest Mandarin Dialects

    Institute of Scientific and Technical Information of China (English)

    张辩辩; 李莎

    2016-01-01

    Kunming Dialect as one of Yunnan area of southwest mandarin dialects has certain research value. This paper explores the vocabulary in Kunming dialects. First,it talks about the characteristics of regional vocabulary. Then, it investigates phonetics. Finally it proposes the social meanings of studying southwest regional dialects.

  19. Local extinction and unintentional rewilding of bighorn sheep (Ovis canadensis) on a desert island.

    Science.gov (United States)

    Wilder, Benjamin T; Betancourt, Julio L; Epps, Clinton W; Crowhurst, Rachel S; Mead, Jim I; Ezcurra, Exequiel

    2014-01-01

    Bighorn sheep (Ovis canadensis) were not known to live on Tiburón Island, the largest island in the Gulf of California and Mexico, prior to the surprisingly successful introduction of 20 individuals as a conservation measure in 1975. Today, a stable island population of ∼500 sheep supports limited big game hunting and restocking of depleted areas on the Mexican mainland. We discovered fossil dung morphologically similar to that of bighorn sheep in a dung mat deposit from Mojet Cave, in the mountains of Tiburón Island. To determine the origin of this cave deposit we compared pellet shape to fecal pellets of other large mammals, and extracted DNA to sequence mitochondrial DNA fragments at the 12S ribosomal RNA and control regions. The fossil dung was 14C-dated to 1476-1632 calendar years before present and was confirmed as bighorn sheep by morphological and ancient DNA (aDNA) analysis. 12S sequences closely or exactly matched known bighorn sheep sequences; control region sequences exactly matched a haplotype described in desert bighorn sheep populations in southwest Arizona and southern California and showed subtle differentiation from the extant Tiburón population. Native desert bighorn sheep previously colonized this land-bridge island, most likely during the Pleistocene, when lower sea levels connected Tiburón to the mainland. They were extirpated sometime in the last ∼1500 years, probably due to inherent dynamics of isolated populations, prolonged drought, and (or) human overkill. The reintroduced population is vulnerable to similar extinction risks. The discovery presented here refutes conventional wisdom that bighorn sheep are not native to Tiburón Island, and establishes its recent introduction as an example of unintentional rewilding, defined here as the introduction of a species without knowledge that it was once native and has since gone locally extinct.

  20. Local extinction and unintentional rewilding of bighorn sheep (Ovis canadensis on a desert island.

    Directory of Open Access Journals (Sweden)

    Benjamin T Wilder

    Full Text Available Bighorn sheep (Ovis canadensis were not known to live on Tiburón Island, the largest island in the Gulf of California and Mexico, prior to the surprisingly successful introduction of 20 individuals as a conservation measure in 1975. Today, a stable island population of ∼500 sheep supports limited big game hunting and restocking of depleted areas on the Mexican mainland. We discovered fossil dung morphologically similar to that of bighorn sheep in a dung mat deposit from Mojet Cave, in the mountains of Tiburón Island. To determine the origin of this cave deposit we compared pellet shape to fecal pellets of other large mammals, and extracted DNA to sequence mitochondrial DNA fragments at the 12S ribosomal RNA and control regions. The fossil dung was 14C-dated to 1476-1632 calendar years before present and was confirmed as bighorn sheep by morphological and ancient DNA (aDNA analysis. 12S sequences closely or exactly matched known bighorn sheep sequences; control region sequences exactly matched a haplotype described in desert bighorn sheep populations in southwest Arizona and southern California and showed subtle differentiation from the extant Tiburón population. Native desert bighorn sheep previously colonized this land-bridge island, most likely during the Pleistocene, when lower sea levels connected Tiburón to the mainland. They were extirpated sometime in the last ∼1500 years, probably due to inherent dynamics of isolated populations, prolonged drought, and (or human overkill. The reintroduced population is vulnerable to similar extinction risks. The discovery presented here refutes conventional wisdom that bighorn sheep are not native to Tiburón Island, and establishes its recent introduction as an example of unintentional rewilding, defined here as the introduction of a species without knowledge that it was once native and has since gone locally extinct.

  1. Local extinction and unintentional rewilding of bighorn sheep (Ovis canadensis) on a desert island

    Science.gov (United States)

    Wilder, Benjamin T.; Betancourt, Julio L.; Epps, Clinton W.; Crowhurst, Rachel S.; Mead, Jim I.; Ezcurra, Exequiel

    2014-01-01

    Bighorn sheep (Ovis canadensis) were not known to live on Tiburón Island, the largest island in the Gulf of California and Mexico, prior to the surprisingly successful introduction of 20 individuals as a conservation measure in 1975. Today, a stable island population of ~500 sheep supports limited big game hunting and restocking of depleted areas on the Mexican mainland. We discovered fossil dung morphologically similar to that of bighorn sheep in a dung mat deposit from Mojet Cave, in the mountains of Tiburón Island. To determine the origin of this cave deposit we compared pellet shape to fecal pellets of other large mammals, and extracted DNA to sequence mitochondrial DNA fragments at the 12S ribosomal RNA and control regions. The fossil dung was 14C-dated to 1476–1632 calendar years before present and was confirmed as bighorn sheep by morphological and ancient DNA (aDNA) analysis. 12S sequences closely or exactly matched known bighorn sheep sequences; control region sequences exactly matched a haplotype described in desert bighorn sheep populations in southwest Arizona and southern California and showed subtle differentiation from the extant Tiburón population. Native desert bighorn sheep previously colonized this land-bridge island, most likely during the Pleistocene, when lower sea levels connected Tiburón to the mainland. They were extirpated sometime in the last ~1500 years, probably due to inherent dynamics of isolated populations, prolonged drought, and (or) human overkill. The reintroduced population is vulnerable to similar extinction risks. The discovery presented here refutes conventional wisdom that bighorn sheep are not native to Tiburón Island, and establishes its recent introduction as an example of unintentional rewilding, defined here as the introduction of a species without knowledge that it was once native and has since gone locally extinct.

  2. Concentration and Distribution of Well Drilling in the Amargosa Desert Area of Southern Nevada

    Science.gov (United States)

    Lee, M. P.; Gross, A. J.; Coleman, N. M.

    2002-05-01

    The earliest sources of fresh water supply in the Amargosa Desert area of Southern Nevada were the abundant, naturally occurring (cold) springs. They initially sustained the indigenous Native American populations and later, Euro-American miners, farmers, and ranchers. Prior to 1900, the many local springs and a few (mostly shallow) hand-dug wells were the principal sources of water supply. The first hand-dug well in the area was the Franklin well; it was dug in 1852 for workers performing a survey of the California-Nevada State line. The first mechanically bored wells were drilled for local railroads, along their respective alignments, sometime between 1905-07. About 1917, the first irrigation well in the Amargosa Desert area was drilled for an experimental farm operated by the Tonopah and Tidewater Railroad. In the late 1940s-early 1950s, permanent interest in the area was established, in large measure because of a Federally sponsored desert reclamation program. For the period 1900-1999, a preliminary evaluation of publicly available information (collected principally by the State Engineer) indicates that more than 950 boreholes were drilled in the Amargosa Desert area. Almost half of these boreholes were drilled in the last 20 years. Forty-two percent of the boreholes were drilled to supply fresh drinking water; 26 percent were in support of irrigated agriculture; 21 percent of the wells were drilled for some non-water supply related purpose - ground-water monitoring and testing; and 11 percent were drilled to supply water for commercial or unspecified applications. Most of the well drilling has been concentrated in a parcel of land about 30-40 kilometers south of the proposed geologic repository at Yucca Mountain, Nevada. Most wells have been generally drilled to depths less than 30 meters (100 feet), although deeper wells are uncommon. The main reason is that drilling is expensive and the profitability of finding and extracting potable water, in sufficient

  3. 76 FR 50493 - Notice of Availability of the Record of Decision for the Desert Sunlight Holdings, LLC, Desert...

    Science.gov (United States)

    2011-08-15

    ... right-of-way (ROW) application CACA-48649 for the Desert Sunlight Solar Farm Project (DSSF). The DSSF is..., the project includes a distribution line, a 220-kV electrical gen-tie transmission line, fiber optic... (RMP) for the project site and the surrounding areas, located in the California Desert District....

  4. Plant responses to an edaphic gradient across an active sand dune/desert boundary in the great basin desert.

    NARCIS (Netherlands)

    Rosenthal, D.M.; Ludwig, F.; Donovan, L.A.

    2005-01-01

    In arid ecosystems, variation in precipitation causes broad-scale spatial heterogeneity in soil moisture, but differences in soil texture, development, and plant cover can also create substantial local soil moisture heterogeneity. The boundary between inland desert sand dunes and adjacent desert hab

  5. The Solar Spectrum in the Atacama Desert

    Science.gov (United States)

    Cordero, R. R.; Damiani, A.; Seckmeyer, G.; Jorquera, J.; Caballero, M.; Rowe, P.; Ferrer, J.; Mubarak, R.; Carrasco, J.; Rondanelli, R.; Matus, M.; Laroze, D.

    2016-03-01

    The Atacama Desert has been pointed out as one of the places on earth where the highest surface irradiance may occur. This area is characterized by its high altitude, prevalent cloudless conditions and relatively low columns of ozone and water vapor. Aimed at the characterization of the solar spectrum in the Atacama Desert, we carried out in February-March 2015 ground-based measurements of the spectral irradiance (from the ultraviolet to the near infrared) at seven locations that ranged from the city of Antofagasta (on the southern pacific coastline) to the Chajnantor Plateau (5,100 m altitude). Our spectral measurements allowed us to retrieve the total ozone column, the precipitable water, and the aerosol properties at each location. We found that changes in these parameters, as well as the shorter optical path length at high-altitude locations, lead to significant increases in the surface irradiance with the altitude. Our measurements show that, in the range 0-5100 m altitude, surface irradiance increases with the altitude by about 27% in the infrared range, 6% in the visible range, and 20% in the ultraviolet range. Spectral measurements carried out at the Izaña Observatory (Tenerife, Spain), in Hannover (Germany) and in Santiago (Chile), were used for further comparisons.

  6. Evolutionary Hotspots in the Mojave Desert

    Directory of Open Access Journals (Sweden)

    Sharyn B. Marks

    2013-04-01

    Full Text Available Genetic diversity within species provides the raw material for adaptation and evolution. Just as regions of high species diversity are conservation targets, identifying regions containing high genetic diversity and divergence within and among populations may be important to protect future evolutionary potential. When multiple co-distributed species show spatial overlap in high genetic diversity and divergence, these regions can be considered evolutionary hotspots. We mapped spatial population genetic structure for 17 animal species across the Mojave Desert, USA. We analyzed these in concurrence and located 10 regions of high genetic diversity, divergence or both among species. These were mainly concentrated along the western and southern boundaries where ecotones between mountain, grassland and desert habitat are prevalent, and along the Colorado River. We evaluated the extent to which these hotspots overlapped protected lands and utility-scale renewable energy development projects of the Bureau of Land Management. While 30–40% of the total hotspot area was categorized as protected, between 3–7% overlapped with proposed renewable energy project footprints, and up to 17% overlapped with project footprints combined with transmission corridors. Overlap of evolutionary hotspots with renewable energy development mainly occurred in 6 of the 10 identified hotspots. Resulting GIS-based maps can be incorporated into ongoing landscape planning efforts and highlight specific regions where further investigation of impacts to population persistence and genetic connectivity may be warranted.

  7. Evolutionary hotspots in the Mojave Desert

    Science.gov (United States)

    Vandergast, Amy G.; Inman, Richard D.; Barr, Kelly R.; Nussear, Kenneth E.; Esque, Todd C.; Hathaway, Stacie A.; Wood, Dustin A.; Medica, Philip A.; Breinholt, Jesse W.; Stephen, Catherine L.; Gottscho, Andrew D.; Marks, Sharyn B.; Jennings, W. Bryan; Fisher, Robert N.

    2013-01-01

    Genetic diversity within species provides the raw material for adaptation and evolution. Just as regions of high species diversity are conservation targets, identifying regions containing high genetic diversity and divergence within and among populations may be important to protect future evolutionary potential. When multiple co-distributed species show spatial overlap in high genetic diversity and divergence, these regions can be considered evolutionary hotspots. We mapped spatial population genetic structure for 17 animal species across the Mojave Desert, USA. We analyzed these in concurrence and located 10 regions of high genetic diversity, divergence or both among species. These were mainly concentrated along the western and southern boundaries where ecotones between mountain, grassland and desert habitat are prevalent, and along the Colorado River. We evaluated the extent to which these hotspots overlapped protected lands and utility-scale renewable energy development projects of the Bureau of Land Management. While 30–40% of the total hotspot area was categorized as protected, between 3–7% overlapped with proposed renewable energy project footprints, and up to 17% overlapped with project footprints combined with transmission corridors. Overlap of evolutionary hotspots with renewable energy development mainly occurred in 6 of the 10 identified hotspots. Resulting GIS-based maps can be incorporated into ongoing landscape planning efforts and highlight specific regions where further investigation of impacts to population persistence and genetic connectivity may be warranted.

  8. Scorpions and scorpionism in Iran's central desert.

    Science.gov (United States)

    Nejati, Jalil; Saghafipour, Abedin; Mozaffari, Ehsan; Keyhani, Amir; Jesri, Nahid

    2017-02-01

    Venomous scorpions have extreme importance in field of medicine and public health. This descriptive - analytic study was done to identify scorpion fauna, their ecological aspects as well as scorpionism for risk management and prevention of this health problem in Iran's central desert. Four urban and fifteen rural areas with various climates and topography locations were selected for monthly scorpion collection through a randomly cluster sampling in 2013. The clinical data was obtained from questionnaires provided in 2009-2014. Totally, 1481 scorpion sting cases were recorded. The majority were treated less than 6h after the sting. Statistical tests showed significant difference between season, scorpion's color, living place of patients and scorpionism cases. Plain areas had the most occurrence of scorpionism followed by foothills. Moreover, 311 scorpion samples belonged to 7 species of Buthidae were collected. Mesobuthus eupeus was the dominant species in both rural and urban areas. Most of the collected samples were from indoors, yards and around the houses. The most scorpion activity was recorded in the summer. The studied areas had rich scorpion fauna due to various climates and topography locations. Scorpion stings can be important and fatal in this area, particularly in the plain regions with semi-desert climate. An investigation for assessment of peoples' awareness on prevention methods of scorpionism and also the determination and the assessment of effective factors on reducing the elapsed time between scorpion stings and receiving medical care are here recommended.

  9. Characteristics of PM10 Chemical Source Profiles for Geological Dust from the South-West Region of China

    Directory of Open Access Journals (Sweden)

    Yayong Liu

    2016-11-01

    Full Text Available Ninety-six particulate matter (PM10 chemical source profiles for geological sources in typical cities of southwest China were acquired from Source Profile Shared Service in China. Twenty-six elements (Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Sr, Cd, Sn, Sb, Ba, Be, Tl and Pb, nine ions (F−, Cl−, SO42−, NO3−, Na+, NH4+, K+, Mg2+ and Ca2+, and carbon-containing species (organic carbon and elemental carbon were determined to construct these profiles. Individual source profiles were averaged and compared to quantify similarities and differences in chemical abundances using the profile-compositing method. Overall, the major components of PM10 in geological sources were crustal minerals and undefined fraction. Different chemical species could be used as tracers for various types of geological dust in the region that resulted from different anthropogenic influence. For example, elemental carbon, V and Zn could be used as tracers for urban paved road dust; Al, Si, K+ and NH4+ for agricultural soil; Al and Si for natural soil; and SO42− for urban resuspended dust. The enrichment factor analysis showed that Cu, Se, Sr and Ba were highly enriched by human activities in geological dust samples from south-west China. Elemental ratios were taken to highlight the features of geological dust from south-west China by comparing with northern urban fugitive dust, loess and desert samples. Low Si/Al and Fe/Al ratios can be used as markers to trace geological sources from southwestern China. High Pb/Al and Zn/Al ratios observed in urban areas demonstrated that urban geological dust was influenced seriously by non-crustal sources.

  10. Early Cambrian sipunculan worms from southwest China.

    Science.gov (United States)

    Huang, Di-Ying; Chen, Jun-Yuan; Vannier, Jean; Saiz Salinas, J I

    2004-08-22

    We report the discovery of sipunculan worms from the Lower Cambrian Maotianshan Shale, near Kunming (southwest China). Their sipunculan identity is evidenced by the general morphology of the animals (sausage-shaped body with a slender retractable introvert and a wider trunk) and by other features, both external (e.g. perioral crown of tentacles, and hooks, papillae and wrinkle rings on the body surface) and internal (U-shaped gut, and the anus opening near the introvert-trunk junction). The three fossil forms (Archaeogolfingia caudata gen. et sp. nov., Cambrosipunculus tentaculatus gen. et sp. nov. and Cambrosipunculus sp.) have striking similarities to modern sipunculans, especially the Golfingiidae to which their evolutionary relationships are discussed. This study suggests that most typical features of extant sipunculans have undergone only limited changes since the Early Cambrian, thus indicating a possible evolutionary stasis over the past 520 Myr.

  11. Solar Energy Development on Department of Defense Installations in the Mojave and Colorado Deserts

    Science.gov (United States)

    2012-01-01

    Wildflowers . Retrieved from http://www.blm.gov/ca/st/en/fo/bakersfield/Programs/carrizo/cpnmflowers1.html. BLM. (2010c). California Desert Conservation...2.2 Legal Regime governing Mojave and Colorado Deserts .................................... 2-13 2.2.1 California Desert Conservation Area (CDCA...2-15 2.2.2 California Desert Protection Act (CDPA) of 1994

  12. Southwest Regional Partnership on Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Brian McPherson

    2006-04-01

    The Southwest Partnership on Carbon Sequestration completed several more tasks during the period of April 1, 2005-September 30, 2005. The main objective of the Southwest Partnership project is to evaluate and demonstrate the means for achieving an 18% reduction in carbon intensity by 2012. While Phase 2 planning is well under way, the content of this report focuses exclusively on Phase 1 objectives completed during this reporting period. Progress during this period was focused in the three areas: geological carbon storage capacity in New Mexico, terrestrial sequestration capacity for the project area, and the Integrated Assessment Model efforts. The geologic storage capacity of New Mexico was analyzed and Blanco Mesaverde (which extends into Colorado) and Basin Dakota Pools were chosen as top two choices for the further analysis for CO{sub 2} sequestration in the system dynamics model preliminary analysis. Terrestrial sequestration capacity analysis showed that the four states analyzed thus far (Arizona, Colorado, New Mexico and Utah) have relatively limited potential to sequester carbon in terrestrial systems, mainly due to the aridity of these areas, but the large land area offered could make up for the limited capacity per hectare. Best opportunities were thought to be in eastern Colorado/New Mexico. The Integrated Assessment team expanded the initial test case model to include all New Mexico sinks and sources in a new, revised prototype model in 2005. The allocation mechanism, or ''String of Pearls'' concept, utilizes potential pipeline routes as the links between all combinations of the source to various sinks. This technique lays the groundwork for future, additional ''String of Pearls'' analyses throughout the SW Partnership and other regions as well.

  13. Gopherus agassizii (Desert Tortoise). Non-native seed dispersal

    Science.gov (United States)

    Ennen, J.R.; Loughran, Caleb L.; Lovich, Jeffrey E.

    2011-01-01

    Sahara Mustard (Brassica tournefortii) is a non-native, highly invasive weed species of southwestern U.S. deserts. Sahara Mustard is a hardy species, which flourishes under many conditions including drought and in both disturbed and undisturbed habitats (West and Nabhan 2002. In B. Tellman [ed.], Invasive Plants: Their Occurrence and Possible Impact on the Central Gulf Coast of Sonora and the Midriff Islands in the Sea of Cortes, pp. 91–111. University of Arizona Press, Tucson). Because of this species’ ability to thrive in these habitats, B. tournefortii has been able to propagate throughout the southwestern United States establishing itself in the Mojave and Sonoran Deserts in Arizona, California, Nevada, and Utah. Unfortunately, naturally disturbed areas created by native species, such as the Desert Tortoise (Gopherus agassizii), within these deserts could have facilitated the propagation of B. tournefortii. (Lovich 1998. In R. G. Westbrooks [ed.], Invasive Plants, Changing the Landscape of America: Fact Book, p. 77. Federal Interagency Committee for the Management of Noxious and Exotic Weeds [FICMNEW], Washington, DC). However, Desert Tortoises have never been directly observed dispersing Sahara Mustard seeds. Here we present observations of two Desert Tortoises dispersing Sahara Mustard seeds at the interface between the Mojave and Sonoran deserts in California.

  14. Evolution and Functional Classification of Vertebrate Gene Deserts

    Energy Technology Data Exchange (ETDEWEB)

    Ovcharenko, I; Loots, G; Nobrega, M; Hardison, R; Miller, W; Stubbs, L

    2004-07-14

    Gene deserts, long stretches of DNA sequence devoid of protein coding genes, span approximately one quarter of the human genome. Through human-chicken genome comparisons we were able to characterized one third of human gene deserts as evolutionarily stable - they are highly conserved in vertebrates, resist chromosomal rearrangements, and contain multiple conserved non-coding elements physically linked to their neighboring genes. A linear relationship was observed between human and chicken orthologous stable gene deserts, where the human deserts appear to have expanded homogeneously by a uniform accumulation of repetitive elements. Stable gene deserts are associated with key vertebrate genes that construct the framework of vertebrate development; many of which encode transcription factors. We show that the regulatory machinery governing genes associated with stable gene deserts operates differently from other regions in the human genome and relies heavily on distant regulatory elements. The regulation guided by these elements is independent of the distance between the gene and its distant regulatory element, or the distance between two distant regulatory cassettes. The location of gene deserts and their associated genes in the genome is independent of chromosomal length or content presenting these regions as well-bounded regions evolving separately from the rest of the genome.

  15. Geomorphometirc Segmentation of Shield Deserts by Self-Organizing Maps

    Science.gov (United States)

    Foroutan, M.; Kompanizare, M.; Ehsani, A. H.

    2015-12-01

    Shield deserts have developed on ancient crystalline bedrocks and mainly composed of folded and faulted rocks hardened by heat and pressure over millions of years. They were unearthed by erosion and form steep-sided hills and basins filled with sediments. The Sahara, Arabian, southern African, central Kavir and Australian deserts are in this group. Their ranges usually supply groundwater resources or in some regions contain huge oil reservoirs. Geomorphological segmentation of shield deserts is one of the fundamental tools in their land use or site investigation planning as well as in their surface water and groundwater management. In many studies the morphology of shield deserts has been investigated by limited qualitative and subjective methods using limited number of simple parameters such as surface elevation and slope. However the importance of these regions supports the need for their accurate and quantitative morphologic classification. The present study attempts to implement a quantitative method, Self-Organizing Map (SOM), for geomorphological classification of a typical shield desert within Kavir Desert, Iran. The area is tectonically stable and characterized by flat clay pans, playas, well-developed pediments around scattered and low elevation ranges. Twenty-two multi-scale morphometric parameters were derived from the first- to third-orders partial derivatives of the surface elevation. Seven optimized parameters with their proper scales were selected by Artificial Neural Networks, Optimum Index Factor, Davies-Bouldin Index and statistic models. Finally, the area was segmented to seven homogeneous areas by SOM algorithm. The results revealed the most distinguishing parameter set (MDPS) for morphologic segmentation of shield deserts. The same segmentation results through using MDPS for another shield deserts in Australia proves the applicability of MDPS for shield deserts segmentation.

  16. Properties of Desert Sand and CMAS Glass

    Science.gov (United States)

    Bansal, Narottam P.; Choi, Sung R.

    2014-01-01

    As-received desert sand from a Middle East country has been characterized for its phase composition and thermal stability. X-ray diffraction analysis showed the presence of quartz (SiO2), calcite (CaCO3), gypsum (CaSO4.2H2O), and NaAlSi3O8 phases in as-received desert sand and showed weight loss of approx. 35 percent due to decomposition of CaCO3 and CaSO4.2H2O when heated to 1400 C. A batch of as-received desert sand was melted into calcium magnesium aluminosilicate (CMAS) glass at approx. 1500 C. From inductively coupled plasma-atomic emission spectrometry, chemical composition of the CMAS glass was analyzed to be 27.8CaO-4MgO-5Al2O3-61.6SiO2-0.6Fe2O3-1K2O (mole percent). Various physical, thermal and mechanical properties of the glass have been evaluated. Bulk density of CMAS glass was 2.69 g/cc, Young's modulus 92 GPa, Shear modulus 36 GPa, Poisson's ratio 0.28, dilatometric glass transition temperature (T (sub g)) 706 C, softening point (T (sub d)) 764 C, Vickers microhardness 6.3 +/- 0.4 GPa, indentation fracture toughness 0.75 +/- 0.15 MPa.m (sup 1/2), and coefficient of thermal expansion (CTE) 9.8 x 10 (exp -6)/degC in the temperature range 25 to 700 C. Temperature dependence of viscosity has also been estimated from various reference points of the CMAS glass using the Vogel-Fulcher-Tamman (VFT) equation. The glass remained amorphous after heat treating at 850 C for 10 hr but crystallized into CaSiO3 and Ca-Mg-Al silicate phases at 900 C or higher temperatures. Crystallization kinetics of the CMAS glass has also been investigated by differential thermal analysis (DTA). Activation energies for the crystallization of two different phases in the glass were calculated to be 403 and 483 kJ/mol, respectively.

  17. Desert Research and Technology Studies 2005 Report

    Science.gov (United States)

    Ross, Amy J.; Kosmo, Joseph J.; Janoiko, Barbara A.; Bernard, Craig; Splawn, Keith; Eppler, Dean B.

    2006-01-01

    During the first two weeks of September 2005, the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) Advanced Extravehicular Activity (AEVA) team led the field test portion of the 2005 Research and Technology Studies (RATS). The Desert RATS field test activity is the culmination of the various individual science and advanced engineering discipline areas year-long technology and operations development efforts into a coordinated field test demonstration under representative (analog) planetary surface terrain conditions. The purpose of the RATS is to drive out preliminary exploration concept of operations EVA system requirements by providing hands-on experience with simulated planetary surface exploration extravehicular activity (EVA) hardware and procedures. The RATS activities also are of significant importance in helping to develop the necessary levels of technical skills and experience for the next generation of engineers, scientists, technicians, and astronauts who will be responsible for realizing the goals of the Constellation Program. The 2005 Desert RATS was the eighth RATS field test and was the most systems-oriented, integrated field test to date with participants from NASA field centers, the United States Geologic Survey (USGS), industry partners, and research institutes. Each week of the test, the 2005 RATS addressed specific sets of objectives. The first week focused on the performance of surface science astro-biological sampling operations, including planetary protection considerations and procedures. The second week supported evaluation of the Science, Crew, Operations, and Utility Testbed (SCOUT) proto-type rover and its sub-systems. Throughout the duration of the field test, the Communications, Avionics, and Infomatics pack (CAI-pack) was tested. This year the CAI-pack served to provide information on surface navigation, science sample collection procedures, and EVA timeline awareness. Additionally, 2005 was the first

  18. Seedling establishment in a masting desert shrub parallels the pattern for forest trees

    Science.gov (United States)

    Meyer, Susan E.; Pendleton, Burton K.

    2015-05-01

    The masting phenomenon along with its accompanying suite of seedling adaptive traits has been well studied in forest trees but has rarely been examined in desert shrubs. Blackbrush (Coleogyne ramosissima) is a regionally dominant North American desert shrub whose seeds are produced in mast events and scatter-hoarded by rodents. We followed the fate of seedlings in intact stands vs. small-scale disturbances at four contrasting sites for nine growing seasons following emergence after a mast year. The primary cause of first-year mortality was post-emergence cache excavation and seedling predation, with contrasting impacts at sites with different heteromyid rodent seed predators. Long-term establishment patterns were strongly affected by rodent activity in the weeks following emergence. Survivorship curves generally showed decreased mortality risk with age but differed among sites even after the first year. There were no detectable effects of inter-annual precipitation variability or site climatic differences on survival. Intraspecific competition from conspecific adults had strong impacts on survival and growth, both of which were higher on small-scale disturbances, but similar in openings and under shrub crowns in intact stands. This suggests that adult plants preempted soil resources in the interspaces. Aside from effects on seedling predation, there was little evidence for facilitation or interference beneath adult plant crowns. Plants in intact stands were still small and clearly juvenile after nine years, showing that blackbrush forms cohorts of suppressed plants similar to the seedling banks of closed forests. Seedling banks function in the absence of a persistent seed bank in replacement after adult plant death (gap formation), which is temporally uncoupled from masting and associated recruitment events. This study demonstrates that the seedling establishment syndrome associated with masting has evolved in desert shrublands as well as in forests.

  19. Aesthetic value of aeolian geomorphosites in the Kumtagh Desert, China

    Institute of Scientific and Technical Information of China (English)

    JinFeng Wu; Xin Wang; Feng Guo; Lei Li

    2014-01-01

    Tourism development of aeolian geomorphosites in the Kumtagh Desert is beneficial to both harmonious development of human-nature relationship and the sustainable development of the tourist industry in the Kumtagh Desert and its sur-rounding area. This paper adopts some research methods including field observation, expert assessment, and systematic investigation to analyze and evaluate the aesthetic value of aeolian geomorphosites in the Kumtagh Desert from three aspects of"Beauty of Morphology","Beauty of Color"and"Beauty of Forms". This research is a creative work in the field of aeolian geomorphosites combining the method of aeolian geomorphology and tourism geography.

  20. Southwest Regional Partnership on Carbon Sequestration Phase II

    Energy Technology Data Exchange (ETDEWEB)

    James Rutledge

    2011-02-01

    The Southwest Regional Partnership (SWP) on Carbon Sequestration designed and deployed a medium-scale field pilot test of geologic carbon dioxide (CO2) sequestration in the Aneth oil field. Greater Aneth oil field, Utah's largest oil producer, was discovered in 1956 and has produced over 455 million barrels of oil (72 million m3). Located in the Paradox Basin of southeastern Utah, Greater Aneth is a stratigraphic trap producing from the Pennsylvanian Paradox Formation. Because it represents an archetype oil field of the western U.S., Greater Aneth was selected as one of three geologic pilots to demonstrate combined enhanced oil recovery (EOR) and CO2 sequestration under the auspices of the SWP on Carbon Sequestration, sponsored by the U.S. Department of Energy. The pilot demonstration focuced on the western portion of the Aneth Unit as this area of the field was converted from waterflood production to CO2 EOR starting in late 2007. The Aneth Unit is in the northwestern part of the field and has produced 149 million barrels (24 million m3) of the estimated 450 million barrels (71.5 million m3) of the original oil in place - a 33% recovery rate. The large amount of remaining oil makes the Aneth Unit ideal to demonstrate both CO2 storage capacity and EOR by CO2 flooding. This report summarizes the geologic characterization research, the various field monitoring tests, and the development of a geologic model and numerical simulations conducted for the Aneth demonstration project. The Utah Geological Survey (UGS), with contributions from other Partners, evaluated how the surface and subsurface geology of the Aneth Unit demonstration site will affect sequestration operations and engineering strategies. The UGS-research for the project are summarized in Chapters 1 through 7, and includes (1) mapping the surface geology including stratigraphy, faulting, fractures, and deformation bands, (2) describing the local Jurassic and Cretaceous stratigraphy, (3) mapping the

  1. Holocene climatic change in Hunshandake Desert

    Institute of Scientific and Technical Information of China (English)

    JIN Heling; SU Zhizhu; SUN Liangying; SUN Zhong; ZHANG Hong; JIN Liya

    2004-01-01

    Research on the geological data of Hunshandake Desert in China monsoon region revealed that Holocene summer monsoon had experienced six prevailing periods and seven weakening periods. The climatic humidity and the vegetation had also undergone the similar periodical variation influenced by the monsoon periodicity. The period when summer monsoon prevailed or winter monsoon weakened and climatic humidity and vegetation coverage relatively increased, corresponded to the global warming events;whereas the period when summer monsoon weakened or winter monsoon prevailed and climatic humidity and vegetation coverage relatively decreased, corresponded to the arid events in middle to low latitudes and the cold events in North Atlantic. As for the changing regularity of summer monsoon intensity there were two distinct periodicities of 1456 years and 494 years, also these two periodicities had global significance.

  2. GPUs: An Oasis in the Supercomputing Desert

    CERN Document Server

    Kamleh, Waseem

    2012-01-01

    A novel metric is introduced to compare the supercomputing resources available to academic researchers on a national basis. Data from the supercomputing Top 500 and the top 500 universities in the Academic Ranking of World Universities (ARWU) are combined to form the proposed "500/500" score for a given country. Australia scores poorly in the 500/500 metric when compared with other countries with a similar ARWU ranking, an indication that HPC-based researchers in Australia are at a relative disadvantage with respect to their overseas competitors. For HPC problems where single precision is sufficient, commodity GPUs provide a cost-effective means of quenching the computational thirst of otherwise parched Lattice practitioners traversing the Australian supercomputing desert. We explore some of the more difficult terrain in single precision territory, finding that BiCGStab is unreliable in single precision at large lattice sizes. We test the CGNE and CGNR forms of the conjugate gradient method on the normal equa...

  3. Eating Behaviors among Early Adolescent African American Girls and Their Mothers

    Science.gov (United States)

    Reed, Monique; Dancy, Barbara; Holm, Karyn; Wilbur, JoEllen; Fogg, Louis

    2013-01-01

    African American (AA) girls aged 10-12 living in urban communities designated as food deserts have a significantly greater prevalence of overweight and obesity than girls that age in the general population. The purpose of our study was (a) to examine the agreement in nutritional intake between AA girls aged 10-12 and their mothers and (b) to…

  4. Neotectonics of the southern Amargosa Desert, Nye County, Nevada and Inyo County, California

    Energy Technology Data Exchange (ETDEWEB)

    Donovan, D.E. [Nevada Univ., Reno, NV (United States)

    1991-05-01

    A complex pattern of active faults occurs in the southern Amargosa Desert, southern Nye, County, Nevada. These faults can be grouped into three main fault systems: (1) a NE-striking zone of faults that forms the southwest extension of the left-lateral Rock Valley fault zone, in the much larger Spotted Range-Mine Mountain structural zone, (2) a N-striking fault zone coinciding with a NNW-trending alignment of springs that is either a northward continuation of a fault along the west side of the Resting Spring Range or a N-striking branch fault of the Pahrump fault system, and (3) a NW-striking fault zone which is parallel to the Pahrump fault system, but is offset approximately 5 km with a left step in southern Ash Meadows. These three fault zones suggest extension is occurring in an E-W direction, which is compatible with the {approximately}N10W structural grain prevalent in the Death Valley extensional region to the west.

  5. Late Pleistocene human occupation of the hyperarid core in the Atacama Desert, northern Chile

    Science.gov (United States)

    Latorre, Claudio; Santoro, Calogero M.; Ugalde, Paula C.; Gayo, Eugenia M.; Osorio, Daniela; Salas-Egaña, Carolina; De Pol-Holz, Ricardo; Joly, Delphine; Rech, Jason A.

    2013-10-01

    Few archeological sites in South America contain uncontroversial evidence for when the first peopling of the continent occurred. Largely ignored in this debate, extreme environments are assumed either as barriers to this early wave of migration or without potential for past habitability. Here, we report on a rare 12-13 ka human occupation from Quebrada Maní (site QM12), a plantless, near rainless landscape (1240 m asl and 85 km from the Pacific Ocean) located in the hyperarid core of the Atacama Desert. This location harbored wetlands and riparian woodlands that were fed by increased rainfall further east in the central Andes during the latest Pleistocene. Excavations at QM12 yielded a diverse cultural assemblage of lithics, burned and cut bones, marine gastropods, pigments, plant fibers, and wooden artifacts alongside a prepared fireplace. Sixteen radiocarbon dates from site QM12 on charcoal, marine shells, animal dung, plant remains and wood reveal that the occupation took place between 12.8 and 11.7 ka. These results demonstrate that the Atacama Desert was not a barrier to early American settlement and dispersal, and provide new clues for understanding the cultural complexity and diversity of the peopling of South America during the Last Glacial-interglacial transition.

  6. Southwest Region Experiment Station - Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Rosenthal, A

    2011-08-19

    Southwest Technology Development Institute (SWTDI), an independent, university-based research institute, has been the operator of the Southwest Region Photovoltaic Experiment Station (SWRES) for almost 30 years. The overarching mission of SWTDI is to position PV systems and solar technologies to become cost-effective, major sources of energy for the United States. Embedded in SWTDI's general mission has been the more-focused mission of the SWRES: to provide value added technical support to the DOE Solar Energy Technologies Program (SETP) to effectively and efficiently meet the R&D needs and targets specified in the SETP Multi-Year Technical Plan. : The DOE/SETP goals of growing U.S. PV manufacturing into giga-watt capacities and seeing tera-watt-hours of solar energy production in the U.S. require an infrastructure that is under development. The staff of the SWRES has supported DOE/SETP through a coherent, integrated program to address infrastructural needs inhibiting wide-scale PV deployment in three major technical categories: specialized engineering services, workforce development, and deployment facilitation. The SWRES contract underwent three major revisions during its five year period-of- performance, but all tasks and deliverables fell within the following task areas: Task 1: PV Systems Assistance Center 1. Develop a Comprehensive multi-year plan 2. Provide technical workforce development materials and workshops for PV stakeholder groups including university, professional installers, inspectors, state energy offices, Federal agencies 3. Serve on the NABCEP exam committee 4. Provide on-demand technical PV system design reviews for U.S. PV stakeholders 5. Provide PV system field testing and instrumentation, technical outreach (including extensive support for the DOE Market Transformation program) Task 2: Design-for-Manufacture PV Systems 1. Develop and install 18 kW parking carport (cost share) and PV-thermal carport (Albuquerque) deriving and publishing

  7. Remote Sensing of Sonoran Desert Vegetation Structure and Phenology with Ground-Based LiDAR

    Directory of Open Access Journals (Sweden)

    Joel B. Sankey

    2014-12-01

    Full Text Available Long-term vegetation monitoring efforts have become increasingly important for understanding ecosystem response to global change. Many traditional methods for monitoring can be infrequent and limited in scope. Ground-based LiDAR is one remote sensing method that offers a clear advancement to monitor vegetation dynamics at high spatial and temporal resolution. We determined the effectiveness of LiDAR to detect intra-annual variability in vegetation structure at a long-term Sonoran Desert monitoring plot dominated by cacti, deciduous and evergreen shrubs. Monthly repeat LiDAR scans of perennial plant canopies over the course of one year had high precision. LiDAR measurements of canopy height and area were accurate with respect to total station survey measurements of individual plants. We found an increase in the number of LiDAR vegetation returns following the wet North American Monsoon season. This intra-annual variability in vegetation structure detected by LiDAR was attributable to a drought deciduous shrub Ambrosia deltoidea, whereas the evergreen shrub Larrea tridentata and cactus Opuntia engelmannii had low variability. Benefits of using LiDAR over traditional methods to census desert plants are more rapid, consistent, and cost-effective data acquisition in a high-resolution, 3-dimensional context. We conclude that repeat LiDAR measurements can be an effective method for documenting ecosystem response to desert climatology and drought over short time intervals and at detailed-local spatial scale.

  8. Alluvial basin statistics of the Southwest Principal Aquifers (SWPA) study.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — SWPA_alvbsn is a vector dataset of alluvial-fill basin statistics for the Southwest United States. Statistics for each basin include physical details such as area,...

  9. 2006 Southwest Florida Water Management District (SWFWMD) Lidar: North District

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is one component of a digital terrain model (DTM) for the Southwest Florida Water Management District's FY2006 Digital Orthophoto (B089) and LiDAR...

  10. Hydrogeologic Areas of the Southwest Principal Aquifer (SWPA) study

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster dataset represents the boundaries of the hydrogeologic areas of the Southwest Principal Aquifer (SWPA) study of the National Water Quality Assessment...

  11. Shallow-Water Benthic Habitats of Southwest Puerto Rico

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Shallow-water (<30m) benthic habitat maps of the nearshore marine environment of two areas in Southwest Puerto Rico (PR), including the Guanica Bay/La Parguera...

  12. Final Critical Habitat for the Desert Tortoise (Gopherus agassizii)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — To provide the user with a general idea of areas where final critical habitat for desert tortoise (Gopherus agassizii) occur based on the description provided in the...

  13. The Trail Inventory of Desert NWR [Cycle 2

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this report is to create a baseline inventory of all non-motorized trails on Desert National Wildlife Range. Trails in this inventory are eligible for...

  14. The Trail Inventory of Desert National Wildlife Refuge [Cycle 1

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this report is to create a baseline inventory of all non-motorized trails on Desert National Wildlife Range. Trails in this inventory are eligible for...

  15. Final Critical Habitat for the Desert yellowhead (Yermo xanthocephalus)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify, in general, the areas where final critical habitat for the Desert yellowhead (Yermo xanthocephalus) occur. The geographic extent includes...

  16. Annual plants in arid and semi-arid desert regions

    Institute of Scientific and Technical Information of China (English)

    Xuehua LI; Xiaolan LI; Deming JIANG; Zhimin LIU; Qinghe YU

    2008-01-01

    Annual plants are the main vegetation in arid and semi-arid desert regions.Because of their unique traits,they are the optimal experimental subjects for eco-logical studies.In this article,we summarize annual plants' seed germination strategies,seedling adaptability mechanism to environments,seed dispersal,and soil seed banks.We also discuss the biotic and abiotic factors affecting the composition and dynamics of annual plant populations and communities.Because annual plants have important ecological functions in desert vegetation systems,this study on annual plants will be of great bene-fit to the conservation and restoration of desert ecosys-tems,the rational utilization of resources,and the sustainable development of desert regions.

  17. Proposal for multi-agency facility : High Desert Interagency Partnership

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a proposal to construct a multi-agency facility to house the High Desert Interagency Partnership. The facility would be on federally owned land in Hines,...

  18. Vegetation - Anza-Borrego Desert State Park [ds165

    Data.gov (United States)

    California Department of Resources — The Anza Borrego Desert State Park (ABDSP) Vegetation Map depicts vegetation within the Park and its surrounding environment. The map was prepared by the Department...

  19. Recovery and vulnerability of the Mojave Desert ecosystem:

    Data.gov (United States)

    Oak Ridge National Laboratory — Desert surfaces are inherently fragile, and many land uses disrupt the thin crusts that typically protect the landscape from wind and water erosion. Depiction of the...

  20. Species status assessment for the Sonoran desert tortoise

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Sonoran desert tortoise (Gopherus morafkai) occurs in various habitat types in Arizona and northern Mexico. It was made a candidate for listing in 2010 by the...

  1. Oregon High Desert Interpretive Center : Economic feasibility and impact analysis

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a proposal to construct a High Desert Interpretive Center to inform visitors to Harney County, Oregon of the opportunities for education, recreation and...

  2. The potential of energy farming in the southeastern California desert

    Science.gov (United States)

    Lew, V.

    1980-04-01

    The use of energy forms to provide future sources of energy for California is considered. Marginal desert lands in southeastern California are proposed for the siting of energy farms using acacia, eucalyptus, euphorbia, guayule, jojoba, mesquite, or tamarisk.

  3. Final Critical Habitat for the Desert pupfish (Cyprinodon macularius)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — To provide the user with a general idea of areas where final critical habitat for desert pupfish (Cyprinodon macularius) occur based on the description provided in...

  4. Geothermal studies in southwest New Mexico: technical completion report

    Energy Technology Data Exchange (ETDEWEB)

    Swanberg, C.A.

    1976-11-01

    The research that has been conducted consists of three parts: (1) A detailed water chemistry study of thermal and non thermal waters in Dona Ana County, (2) a reconnaissance water chemistry study of the hot springs of southwest New Mexico, and (3) a detailed gravity and magnetic study of the Lightning Dock KGRA (Known Geothermal Resource Area) located in the Animas Valley of southwest New Mexico. The principal features resulting from this state supported research program are presented.

  5. American ginseng

    Science.gov (United States)

    ... and inflammation of the lining of the stomach (gastritis). American ginseng is also used for low iron ... Dizziness. Pregnancy and childbirth complications. Stress. Anemia. Insomnia. Gastritis. Impotence. Fever. Hangover symptoms. Headaches. Swine flu. Aging. ...

  6. Prediction of Dust Propensity for Military Operations in Desert Areas

    Science.gov (United States)

    1988-11-01

    FWE GOPI TECHNICAL REPORT EL8-1 PREDICTION OF DUST PROPENSITY FOR of Eginers’.MILITARY OPERATIONS IN DESERT AREAS by William K. Dornbusch , John N...11 TTLE~ ~I IAT40 30/069 Prediction of Dust Propensity for Military operations in Desert Areas 12. F"RSONAL AVTNO9(%) Dornbusch . William K.; Strange...Harrison was Chief, EL. The study was performed and this report was written by Messrs. William K. Dornbusch , John N. Strange, and Allen D. Rooke, Jr

  7. A Future for the Past of Desert Vernacular Architecture

    OpenAIRE

    2011-01-01

    Desert vernacular architecture has always been the product of a sustainable building cycle. People inherited the traditional way of building from their ancestors and the knowledge was transferred and developed from one generation to another. Inhabitants responded to their environment and climate through trial and error in a way that satisfied their needs and aspirations to create a developing building tradition. This natural and cultural cycle is about to disappear in many desert vernacular s...

  8. Ecological and evolutionary physiology of desert birds: a progress report.

    Science.gov (United States)

    Williams, Joseph B; Tieleman, B Irene

    2002-02-01

    The adaptive significance of mechanisms of energy and water conservation among species of desert rodents, which avoid temperature extremes by remaining within a burrow during the day, is well established. Conventional wisdom holds that arid-zone birds, diurnal organisms that endure the brunt of their environment, occupy these desert climates because of the possession of physiological design features common to all within the class Aves. We review studies that show that desert birds may have evolved specific features to deal with hot desert conditions including: a reduced basal metabolic rate (BMR) and field metabolic rate (FMR), and lower total evaporative water loss (TEWL) and water turnover (WTO).Previous work on the comparative physiology of desert birds relied primarily on information gathered on species from the deserts of the southwestern U.S., which are semi-arid habitats of recent geologic origin. We include data on species from Old World deserts, which are geologically older than those in the New World, and place physiological responses along an aridity axis that includes mesic, semi-arid, arid, and hyperarid environments.The physiological differences between desert and mesic birds that we have identified using the comparative method could arise as a result of acclimation to different environments, of genetic change mediated by selection, or both. We present data on the flexibility of BMR and TEWL in Hoopoe Larks that suggest that phenotypic adjustments in these variables can be substantial. Finally, we suggest that linkages between the physiology of individual organism and its life-history are fundamental to the understanding of life-history evolution.

  9. Environmental racism: the US nuclear industry and native Americans

    Energy Technology Data Exchange (ETDEWEB)

    Lehtinen, Ulla [Organization of the Fourth World - First Peoples (Finland)

    1997-03-01

    The author argues that the United States nuclear industry has acted in a discriminatory fashion towards Native American peoples and the land they hold as reservations. Both uranium mining and nuclear weapons testing is commonplace and plans now exist to locate a low-level radioactive waste dump in the Mojave desert in California, a sacred site for many native people. Opposition to such plans is growing among the Native Americans, sharpened by their existing commitment to conservation of the environment, but on their own, they are not a lobby powerful enough to oppose the might of the nuclear industry. (UK).

  10. Jurassic zircons from the Southwest Indian Ridge

    Science.gov (United States)

    Cheng, Hao; Zhou, Huaiyang; Yang, Qunhui; Zhang, Lingmin; Ji, Fuwu; Dick, Henry

    2016-05-01

    The existence of ancient rocks in present mid-ocean ridges have long been observed but received less attention. Here we report the discovery of zircons with both reasonably young ages of about 5 Ma and abnormally old ages of approximate 180 Ma from two evolved gabbroic rocks that were dredged from the Southwest Indian Ridge (SWIR) in the Gallieni fracture zone. U-Pb and Lu-Hf isotope analyses of zircons were made using ion probe and conventional laser abrasion directly in petrographic thin sections. Young zircons and their host oxide gabbro have positive Hf isotope compositions (ɛHf = +15.7-+12.4), suggesting a highly depleted mantle beneath the SWIR. The spread ɛHf values (from-2.3 to-4.5) of abnormally old zircons, together with the unradiogenic Nd-Hf isotope of the host quartz diorite, appears to suggest an ancient juvenile magmatism along the rifting margin of the southern Gondwana prior to the opening of the Indian Ocean. A convincing explanation for the origin of the unusually old zircons is yet to surface, however, an update of the theory of plate tectonics would be expected with continuing discovery of ancient rocks in the mid-oceanic ridges and abyssal ocean basins.

  11. TAP Report - Southwest Idaho Juniper Working Group

    Energy Technology Data Exchange (ETDEWEB)

    Gresham, Garold Linn [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    There is explicit need for characterization of the materials for possible commercialization as little characterization data exists. Pinyon-juniper woodlands are a major ecosystem type found in the Southwest and the Intermountain West regions of the United States including Nevada, Idaho and Oregon. These widespread ecosystems are characterized by the presence of several different species of pinyon and juniper as the dominant plant cover. Since the 1800s, pinyon-juniper woodlands have rapidly expanded their range at the expense of existing ecosystems. Additionally, existing woodlands have become denser, progressively creating potential fire hazards as seen in the Soda Fire, which burned more than 400 sq. miles. Land managers responsible for these areas often desire to reduce pinyon-juniper coverage on their lands for a variety of reasons, as stated in the Working Group objectives. However, the cost of clearing thinning pinyon-juniper stands can be prohibitive. One reason for this is the lack of utilization options for the resulting biomass that could help recover some of the cost of pinyon-juniper stand management. The goal of this TAP effort was to assess the feedstock characteristics of biomass from a juniper harvested from Owyhee County to evaluate possible fuel and conversion utilization options.

  12. Jurassic zircons from the Southwest Indian Ridge.

    Science.gov (United States)

    Cheng, Hao; Zhou, Huaiyang; Yang, Qunhui; Zhang, Lingmin; Ji, Fuwu; Dick, Henry

    2016-05-17

    The existence of ancient rocks in present mid-ocean ridges have long been observed but received less attention. Here we report the discovery of zircons with both reasonably young ages of about 5 Ma and abnormally old ages of approximate 180 Ma from two evolved gabbroic rocks that were dredged from the Southwest Indian Ridge (SWIR) in the Gallieni fracture zone. U-Pb and Lu-Hf isotope analyses of zircons were made using ion probe and conventional laser abrasion directly in petrographic thin sections. Young zircons and their host oxide gabbro have positive Hf isotope compositions (εHf = +15.7-+12.4), suggesting a highly depleted mantle beneath the SWIR. The spread εHf values (from-2.3 to-4.5) of abnormally old zircons, together with the unradiogenic Nd-Hf isotope of the host quartz diorite, appears to suggest an ancient juvenile magmatism along the rifting margin of the southern Gondwana prior to the opening of the Indian Ocean. A convincing explanation for the origin of the unusually old zircons is yet to surface, however, an update of the theory of plate tectonics would be expected with continuing discovery of ancient rocks in the mid-oceanic ridges and abyssal ocean basins.

  13. Contraction of the Gobi Desert, 2000–2012

    Directory of Open Access Journals (Sweden)

    Troy Sternberg

    2015-01-01

    Full Text Available Deserts are critical environments because they cover 41% of the world’s land surface and are home to 2 billion residents. As highly dynamic biomes desert expansion and contraction is influenced by climate and anthropogenic factors with variability being a key part of the desertification debate across dryland regions. Evaluating a major world desert, the Gobi in East Asia, with high resolution satellite data and the meteorologically-derived Aridity Index from 2000 to 2012 identified a recent contraction of the Gobi. The fluctuation in area, primarily driven by precipitation, is at odds with numerous reports of human-induced desertification in Mongolia and China. There are striking parallels between the vagueness in defining the Gobi and the imprecision and controversy surrounding the Sahara desert’s southern boundary in the 1980s and 1990s. Improved boundary definition has implications fGobi; desert boundary; expansion and contraction; Aridity Index; NDVI; Mongolia; China or understanding desert “greening” and “browning”, human action and land use, ecological productivity and changing climate parameters in the region. The Gobi’s average area of 2.3 million km2 in the 21st century places it behind only the Sahara and Arabian deserts in size.

  14. Optimization of precipitation and streamflow forecasts in the southwest Contiguous US for warm season convection

    Science.gov (United States)

    Lahmers, T.; Castro, C. L.; Gupta, H. V.; Gochis, D. J.; ElSaadani, M.

    2015-12-01

    Warm season convection associated with the North American Monsoon (NAM) provides an important source of precipitation for much of the Southwest Contiguous US (CONUS) and Northwest Mexico. Convection associated with the NAM can also result in flash flooding, a hazard to metropolitan areas such as Tucson and Phoenix, as well as rural areas where washouts of main roads can sever critical transportation infrastructure. In order to mitigate the effects of this problem, the National Oceanic and Atmospheric Administration (NOAA) National Water Center (NWC) is developing a national distributed hydrologic model using the WRF-Hydro framework with forcing from the High Resolution Rapid Refresh (HRRR) mesoscale atmospheric model. We aim to improve this National hydrologic and atmospheric modeling framework through the calibration of the WRF-Hydro model for the southwest CONUS and the optimization of planetary boundary layer and cloud microphysics schemes for the Weather Research and Forecasting (WRF) model in the same region. The WRF-Hydro model, with a similar structure as the national configuration used by the NWC, has been set up for the Gila River basin in southern Arizona. We demonstrate the utility of the model for forecasting high impact precipitation events in catchments with limited human modification. The WRF-Hydro model is spun up using past precipitation from the NCEP Stage-IV records and TRMM estimates. Atmospheric forcing for WRF-Hydro comes from the NASA Phase 2 North American Land Data Assimilation (NLDAS-2) dataset. WRF-Hydro is forced for selected high-impact events using a 3-km grid resolution Advanced Research WRF (WRF-ARW) atmospheric simulation. WRF-ARW is forced with the operational National Center for Environmental Prediction (NCEP) Global Forecasting System (GFS) operational model. This methodology demonstrates the modeling framework that will be used for future parameter calibration of WRF-Hydro and optimization of WRF-ARW.

  15. American Dream in Early American Literatuer

    Institute of Scientific and Technical Information of China (English)

    屈彩娥; 李小玺

    2008-01-01

    American dream has often been closely rehted to American literature.Many say that the American literary history can be seen as the history of American dreams.In most periods in history,writers,whose dreams have been infused in a variety of characters create the American literature.While in Early American literature,American dream had been presented in a dif-ferent way.

  16. The Republic of Mexico and the United States of America: The Mexican-American War -- In Retrospect. Fulbright-Hays Summer Seminar Abroad 1996 (Mexico).

    Science.gov (United States)

    Juarez, Pablo Hill

    The unit is intended as part of a world cultures curriculum taught at the 10th grade level. The lessons include: (1) "Mexico in Brief"; (2) "The Mexican American War 1846-1848"; and (3) "History and Educational Status of Americans of Mexican Descent (Chicanos) in the Southwest." Additional resources and a 32-item bibliography accompany the unit.…

  17. Respondence and feedback of modern sand deserts to climate change--A case study in Gurbantunggut Desert

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The research on the respondence and feedback of modern sand deserts to the climate change is an important component part in the studies on the global climate change. Deserts respond to the climate change, meanwhile, they affect the climate with their feedback of peculiar environment during the respondence. Many researches on desert climate have been carried out at home and abroad. However, there is little research on the respondence and feedback of modern fixed, semi-fixed and mobile deserts in arid areas to the climate change, in which the factor analysis as well as the parameter changing effects is especially the difficult problem all along. In this note, the parameters of the respondence and feedback of Gurbantunggut Desert to the climate change are measured and analyzed, some variable parameters of water-heat exchange are obtained, and a numerical model of desertification is developed according to a series of climate change of about 40 years and the variable relations of meteorological and physical features of the sand surface in Gurbantunggut Desert.

  18. Remarkable movements of an American crocodile (Crocodylus acutus) in Florida

    Science.gov (United States)

    Cherkiss, Michael S.; Mazzotti, Frank J.; Hord, Lindsey; Aldecoa, Mario

    2014-01-01

    Here we present the remarkable movements of an individual Crocodylus acutus (American Crocodile) over a 14-year period. The crocodile was originally marked in Homestead, FL as a young-of-the-year in 1999, and was later recaptured multiple times more than 388 km away along the southwest coast of Florida. After several relocations and numerous sightings, this individual who has become known as Yellow Number 1 was found back within the same canal system in which it was first captured.

  19. Searching for Life in Death Valley (and Other Deserts) - Microchemical Investigations on Desert Varnish

    Science.gov (United States)

    Andreae, M. O.; Al-Amri, A. M.; Jochum, K. P.; Kappl, M.; Kilcoyne, A. D.; Macholdt, D.; Müller, M.; Pöhlker, C.; Weber, B.; Weigand, M.

    2014-12-01

    Desert varnishes are thin, shiny, blackish to brown coatings frequently found on the surfaces of exposed rocks in deserts around the globe. They have been proposed as terrestrial analogues of superficial hematite enrichments observed on Mars. While the first scientific studies of such varnishes go back to Darwin and von Humboldt, and intensive studies by a variety of techniques have been conducted over the last few decades, their origin is still a matter of debate. Microscopic and molecular studies have shown the presence of fungi and bacteria, but it is still unclear whether they are involved in the formation of the varnish material or just opportunistic colonizers on available surfaces. We have analysed samples of desert varnish from sites in Death Valley, the Mojave Desert, the Negev of Israel, Central Saudi Arabia, and the Succulent Karoo by a variety of microanalytical techniques. Measurements by UV-femtosecond Laser Ablation Inductively Coupled Plasma Mass Spectrometry show enrichments of manganese, iron, barium and other elements. Isotopic and trace chemical signatures show that these enriched elements cannot originate from the rocks that form the substrate on which the crusts have been deposited, but most likely are the result of (bio?)chemical transformation of windblown material. For a more detailed investigation of the internal structure of the crusts, we prepared ultra-thin sections (~100 nm) using focused ion beam slicing and analysed them by Scanning Transmission X-ray Microscopy with Near-Edge X-ray Absorption Fine Structure spectroscopy (STXM-NEXAFS). This technique revealed layered or chaotic structures consisting of alternating Mn and Fe-rich zones. Some of these layers are enriched in organic carbon with spectral features dominated by aromatic and carboxylate functionalities, indicating a biological origin of some of the crust material. Some crusts also show cavities that are lined with similar organic material. Since the age of these crusts is

  20. Southwest Region Experiment Station 1988 report

    Energy Technology Data Exchange (ETDEWEB)

    1989-05-01

    The highlights of tasks performed during 1988 by staff members at the Southwest Region Experiment Station (SWRES) are summarized in this report. During 1988, our staff tested and evaluated photovoltaic systems, designed hardware for data acquisition systems, developed software for data analysis, and demonstrated the uses of Photovoltaics (PVs) to the public. Field evaluations of stand-alone and grid-connected systems were a major project for the SWRES in 1988. The goal was to determine the reliability of PV systems, to identify degradation trends, and to recommend solutions to problems. In 1988, the SWRES staff visited 7 sites and tested and evaluated 11 PV systems. Four of the seven tests were paid for under the DOE contract, the balance paid for by private companies or agencies. They were about 7200 crystalline and 2200 amorphous silicon (a-Si) modules tested in 1988. Forty-eight crystalline modules were nonproducing; thirty-nine of them in the Georgetown array. Some problems with the a-Si modules were found. However, the significance of these various failures is hard to determine. The failures are hard to categorize because of the differences in this newer technology. The system ratings determined by the SWRES continue to be lower than the commonly referenced number. Georgetown is the worst example--being rated at 210 kW compared to the 300kW value used to describe the system. Testing results from other systems show system rating 5 to 15 percent below nameplate. The system testing performed by the SWRES show that module failures rates for crystalline modules is lower than 2/10,000 per year including the high number of failures at Georgetown. For systems that have been operating over seven years, it is still difficult to pinpoint any degradation trend in year to year performance. 23 figs., 2 tabs.

  1. [Estimation of aboveground biomass of desert plants].

    Science.gov (United States)

    Zhao, Chengyi; Song, Yudong; Wang, Yuchao; Jiang, Pinan

    2004-01-01

    Based on the research of plant quadrate in Sangong River Basin in Xinjiang, the fitted equations were given, which could be used to estimate the aboveground biomass of typical desert plant by using the thicket characteristics such as length of crown diameter, width of crown diameter, number of basal branch, length of new branch, basal diameter (D) and plant height (H) as parameters. Using the length of crown diameter and the width of crown diameter as parameters, the fitted equation was set up and tested for estimating the aboveground biomass of Reaumuria soongorica Maxim. It had a relatively high accuracy and a fine linear relationship between the predicted values and measured values. Its coefficient and relative standard deviation was 0.9989 and 4.79%-10.12%, respectively. The results indicated that the fitted equation was easy and available for estimating the aboveground biomass of Reaumuria soongorica Maxim in large scale. The fitted equations were also set up and tested for estimating the aboveground biomass of Haloxylon ammodendron and Tamarix ramosissima by using the basal diameter and height of plant as the parameters. The coefficients and relative standard deviations of these equations were 0.9902, 0.9875 and 6.87%-19.22%, 7.49%-18.47%, respectively. Therefore, estimating the biomass of Reaumuria soongorica in large scale through crown characteristics was available, and estimating the biomass of Halaxylon Ammodendron and Tamarix ramosissima through crown characteristics would produce certain error.

  2. Determination of bioclimatic comfort in Sirjan desert

    Directory of Open Access Journals (Sweden)

    Tayebeh Mahmoodi

    2012-04-01

    Full Text Available Climate plays an important role in assessment of quality of outdoor built environments and bioclimatic comfort physiologically influences on human body's characteristics. In this paper, we present an empirical study on bioclimatic comfort in Sirjan desert located in the province of Kerman, Iran. The results of our study shows that velocity of air can reach one meter per second during the daily hours only during the month of September, which causes comfort on people's body. However, even this velocity cannot cause comfort during the night. During the months of March, April and October, whether maintains a velocity of 0.1 meter/second, which brings comfort and it is possible to live with simple dress. During the months of May, June and July it is possible to reach comfort with simple cover during the night. It is possible to reach the same condition with thicker coverage in nightly hours during the months of May and September. However, it is not possible to reach comfort with thick dress any nightly hours of year.

  3. Copper isotope fractionation by desert shrubs

    Energy Technology Data Exchange (ETDEWEB)

    Navarrete, Jesica U., E-mail: jnavarrete2@miners.utep.edu [University of Texas at El Paso, Department of Geological Sciences, 500 W. University Ave, El Paso, TX 79968 (United States); Viveros, Marian; Ellzey, Joanne T. [University of Texas at El Paso, Department of Biological Sciences, El Paso, TX 79968 (United States); Borrok, David M. [University of Texas at El Paso, Department of Geological Sciences, 500 W. University Ave, El Paso, TX 79968 (United States)

    2011-06-15

    Copper has two naturally occurring stable isotopes of masses 63 and 65 which can undergo mass dependent fractionation during various biotic and abiotic chemical reactions. These interactions and their resulting Cu isotope fractionations can be used to determine the mechanisms involved in the cycling of Cu in natural systems. In this study, Cu isotope changes were investigated at the organismal level in the metal-accumulating desert plant, Prosopis pubescens. Initial results suggest that the lighter Cu isotope was preferentially incorporated into the leaves of the plant, which may suggest that Cu was actively transported via intracellular proteins. The roots and stems show a smaller degree of Cu isotope fractionation and the direction and magnitude of the fractionations was dependent upon the levels of Cu exposure. Based on this and previous work with bacteria and yeast, a trend is emerging that suggests the lighter Cu isotope is preferentially incorporated into biological components, while the heavier Cu isotope tends to become enriched in aqueous solutions. In bacteria, plants and animals, intracellular Cu concentrations are strictly regulated via dozens of enzymes that can bind, transport, and store Cu. Many of these enzymes reduce Cu(II) to Cu(I). These initial results seem to fit into a broader picture of Cu isotope cycling in natural systems where oxidation/reduction reactions are fundamental in controlling the distributions of Cu isotopes.

  4. Closed bioregenerative life support systems: Applicability to hot deserts

    Science.gov (United States)

    Polyakov, Yuriy S.; Musaev, Ibrahim; Polyakov, Sergey V.

    2010-09-01

    Water scarcity in hot deserts, which cover about one-fifth of the Earth's land area, along with rapid expansion of hot deserts into arable lands is one of the key global environmental problems. As hot deserts are extreme habitats characterized by the availability of solar energy with a nearly complete absence of organic life and water, space technology achievements in designing closed ecological systems may be applicable to the design of sustainable settlements in the deserts. This review discusses the key space technology findings for closed biogenerative life support systems (CBLSS), which can simultaneously produce food, water, nutrients, fertilizers, process wastes, and revitalize air, that can be applied to hot deserts. Among them are the closed cycle of water and the acceleration of the cycling times of carbon, biogenic compounds, and nutrients by adjusting the levels of light intensity, temperature, carbon dioxide, and air velocity over plant canopies. Enhanced growth of algae and duckweed at higher levels of carbon dioxide and light intensity can be important to provide complete water recycling and augment biomass production. The production of fertilizers and nutrients can be enhanced by applying the subsurface flow wetland technology and hyper-thermophilic aerobic bacteria for treating liquid and solid wastes. The mathematical models, optimization techniques, and non-invasive measuring techniques developed for CBLSS make it possible to monitor and optimize the performance of such closed ecological systems. The results of long-duration experiments performed in BIOS-3, Biosphere 2, Laboratory Biosphere, and other ground-based closed test facilities suggest that closed water cycle can be achieved in hot-desert bioregenerative systems using the pathways of evapotranspiration, condensation, and biological wastewater treatment technologies. We suggest that the state of the art in the CBLSS design along with the possibility of using direct sunlight for

  5. Information Processing Patterns of Postsecondary American Indian/Alaska Native Students

    Science.gov (United States)

    Aragon, Steven R.

    2004-01-01

    In the last of a three-part series, this study examined the information processing patterns of postsecondary American Indian/Alaska Native students attending community and tribal colleges in the Southwest. Using a survey design, students completed the Kolb Learning Style Inventory, the Briggs and Myers Myers-Briggs Type Indicator, and the Oltman,…

  6. Creating an Instrument to Measure People's Perception of Community Capacity in American Indian Communities

    Science.gov (United States)

    Oetzel, John; Wallerstein, Nina; Solimon, Audrey; Garcia, Bruce; Siemon, Mark; Adeky, Sarah; Apachito, Gracie; Caston, Elissa; Finster, Carolyn; Belone, Lorenda; Tafoya, Greg

    2011-01-01

    The purpose of this study was to develop a measure of community capacity for American Indian communities. The study included development and testing phases to ensure face, content, construct, and predictive validity. There were 500 participants in two southwest tribes who completed a detailed community profile, which contained 21 common items in…

  7. American Culture Reflected in American English

    Institute of Scientific and Technical Information of China (English)

    李华芳

    2013-01-01

    Language is a vehicle for culture. It is also a key component of culture. It not only reflects culture but also influences culture. As a variety of British English, American English, especially American words and expressions can reflect American culture from many aspects. This paper studies some typical traits of American culture reflected in words and expressions of American Eng-lish.

  8. American Connections

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    2015-01-01

    The Danish artist Thomas Bang spent his early years in the USA. The works he created in this formative period were thus profoundly shaped by the contemporary movements in American art of the 1960s and 1970s when sculpture, or to be more precise, three-dimensional work became a hotbed of expansive...... experiments. This article traces how Bang made a radical move from painting to sculpture, which was characteristic of that time, and how he developed his artistic idiom by taking an active part in some of the seminal new departures in American art, in particular process art and post-minimalism. By leaping...... to the lasting impact of Bang's American period, which remains the key to understanding his works....

  9. Water sources for cyanobacteria below desert rocks in the Negev Desert determined by conductivity

    Directory of Open Access Journals (Sweden)

    Christopher P. McKay

    2016-04-01

    Full Text Available We present year round meteorological and conductivity measurements of colonized hypolithic rocks in the Arava Valley, Negev Desert, Israel. The data indicate that while dew is common in the Negev it is not an important source of moisture for hypolithic organisms at this site. The dominance of cyanobacteria in the hypolithic community is consistent with predictions that cyanobacteria are confined to habitats supplied by rain. To monitor the presence of liquid water under the small Negev rocks we developed and tested a simple field conductivity system based on two wires placed about 0.5 cm apart. Based on 21 replicates recorded for one year in the Negev we conclude that in natural rains (0.25 mm to 6 mm the variability between sensor readings is between 20 and 60% decreasing with increasing rain amount. We conclude that the simple small electrical conductivity system described here can be used effectively to monitor liquid water levels in lithic habitats. However, the natural variability of these sensors indicates that several replicates should be deployed. The results and method presented have use in arid desert reclamation programs.

  10. Water Sources for Cyanobacteria Below Desert Rocks in the Negev Desert Determined by Conductivity

    Science.gov (United States)

    McKay, Christopher P.

    2016-01-01

    We present year round meteorological and conductivity measurements of colonized hypolithic rocks in the Arava Valley, Negev Desert, Israel. The data indicate that while dew is common in the Negev it is not an important source of moisture for hypolithic organisms at this site. The dominance of cyanobacteria in the hypolithic community are consistent with predictions that cyanobacteria are confined to habitats supplied by rain. To monitor the presence of liquid water under the small Negev rocks we developed and tested a simple field conductivity system based on two wires placed about 0.5 cm apart. Based on 21 replicates recorded for one year in the Negev we conclude that in natural rains (0.25 mm to 6 mm) the variability between sensor readings is between 20 and 60% decreasing with increasing rain amount. We conclude that the simple small electrical conductivity system described here can be used effectively to monitor liquid water levels in lithic habitats. However, the natural variability of these sensors indicates that several replicates should be deployed. The results and method presented have use in arid desert reclamation programs.

  11. American Houses

    Institute of Scientific and Technical Information of China (English)

    张梦华

    2004-01-01

    American houses usually have private kitchens,a living room and sometimes separate areas for eating and watching television,A house usually has its own mailbox,a yard with plants or perhaps a lawn,and a place to store garbage out of sight.

  12. The Ocean deserts:salt budgets of northern subtropical oceans and their

    KAUST Repository

    Carton, Jim

    2011-04-09

    The Ocean deserts: salt budgets of northern subtropical oceans and their relationship to climate variability The high salinity near surface pools of the subtropical oceans are the oceanic deserts, with high levels of evaporation and low levels of precip

  13. Desert Tortoise Head-start Program at Twentynine Palms Marine Base

    Science.gov (United States)

    2013-04-02

    Hillard. Shell hardness measurement in juvenile desert tortoises, Gopherus agassizii, Herpetological Review, (09 2011): 0. doi: 07/23/2012 2.00...yearlings released to the open desert. Herpetological Conservation and Biology.

  14. 77 FR 65133 - Revisions to the California State Implementation Plan, Mojave Desert Air Quality Management District

    Science.gov (United States)

    2012-10-25

    ... Identification of plan. * * * * * (c) * * * (379) * * * (i) * * * (E) Mojave Desert Air Quality Management... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Mojave Desert Air Quality Management District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA...

  15. Residential Exposure to Nighttime Retained Heat in the El Paso, Texas, USA Desert Metroplex

    Science.gov (United States)

    Amaya, M. A.; Mohammed, M.; Pingitore, N. E.; Aldouri, R. K.; Benedict, B. A.

    2013-12-01

    albedo and elevation as secondary drivers. Using archived satellite imagery we determined that over the last two decades there has been an increase in both day and nighttime temperatures. With no expected change in urban growth and global warming, local residents will be at increasing risk in the future, as will residents in other urban centers in the desert southwest of the US. We currently are evaluating exposure risk in different population sectors. Do the aged or the poor reside in higher risk neighborhoods? Are there simple measures that can be taken to ameliorate nighttime temperatures?

  16. Cryophenomena in the Cold Desert of Atacama

    Science.gov (United States)

    Buchroithner, Dr.; Trombotto, Dr.

    2012-04-01

    The study area of the Valle de Barrancas Blancas in the High Atacama Andes of Chile (68°39' W, 27°02' S), a kind of Patagonian "bajo sin salida", shows well preserved landforms resulting from a combination of slope, eolian, lacustrine/litoral, fluvial, glacial and periglacial regimes. They permit the reconstruction of geomorphological processes within this isolated catchment of approximately 160 km2. The mean annual air temperature varies between -2 and -4 °C and the precipitation is approximately 150 mm/a. Snowfall is frequent but the snow is quickly sublimated, redeposited and/or covered by cryosediments, i.e. mainly pumice pebbles. Water bodies present icings, even in summer. Regarding its climatic conditions the study area represents an extremely cold desertic region. Extremophile microfauna was also found. The area displays both in situ mountain permafrost and creeping permafrost. The active layer is 30 to 45 cm thick. It is a periglacial macro-environment where interdependent processes, and not only cryogenic processes but also erosion and eolian deposition and the action of fluvial washout mainly caused by precipitation, accumulation, retransportation/redeposition and melting of snow, play an important role. The cryogenic geomorphology of the Valle de Barrancas Blancas is varied and contains microforms such as patterned ground and microforms caused by cryoturbation, as well as mesoforms like rockglaciers and cryoplanation surfaces. Slopes are strongly affected by gelifluction. New cryoforms in South America and in the Southern Hemisphere like the Atacama Pingo (Pingo atacamensis) and Permafrosted Dunes ("Dunas heladas") were found. Intense niveo-eolian processes participate in the erosion of preexisting landforms, in the formation of subterraneous ice layers, and the retransportation/redeposition of snow and sediments. Studies of this periglacial environment are crucial for the understanding of Tundrean paleoenvironments and Martian conditions.

  17. Responses of Plants’ Phenology to Climate Warming in the Desert Area in Northwestern China

    OpenAIRE

    Zhaofeng Chang; Shujuan Zhu; Fugui Han; Shengnian Zhong; Qiangqiang Wang

    2013-01-01

    With climate warming, plants’ spring phenology has advanced while autumn phenology has delayed. How does the phenology of desert plants respond to climatic variation? To reveal it, this study analyzed the phenological data of 22 desert species growing in the Minqin Desert Plants Botanical Garden located in the typical desert area in northwest China. The data was observed during the year 1974-2009. Results revealed that comparing with the literatures available, the temperature in the study are...

  18. Condition-dependent clutch desertion in Great Tit (Parus major) females subjected to human disturbance

    OpenAIRE

    Dubiec, Anna

    2011-01-01

    Abstract Nest desertion behaviour in relation to body condition and timing of breeding was studied in Great Tit (Parus major) females during two breeding seasons. Desertion, most likely unintentionally provoked by catching females during the incubation period, occurred at a very high rate with 41.2 and 25.6% of deserted first clutches in the two study years. The association between desertion probability, body condition (index calculated as residuals from the regression of body mass...

  19. A Physical Model for Extreme Drought over Southwest Asia

    Science.gov (United States)

    Hoell, A.; Barlow, M. A.; Funk, C. C.; Cannon, F.

    2015-12-01

    The socioeconomic difficulties of Southwest Asia, defined as the area bound by the domain 25°N-40°N and 40°E-70°E, which includes the countries of Iran, Afghanistan and Pakistan, are exacerbated by extreme precipitation deficits during the November-April rainy season. The precipitation deficits during many Southwest Asia droughts have been examined in terms of the forcing by climate variability originating over the Pacific Ocean as a result of the El Niño-Southern Oscillation (ENSO), Pacific Decadal Variability (PDV) and the long-term warming of Pacific (LT) sea surface temperatures (SST). Here, we 1) examine how the most extreme November-April Southwest Asia droughts relate to global SSTs and the associated large-scale atmospheric circulation anomalies, 2) analyze the specific atmospheric forcing mechanisms responsible for changes in regional Southwest Asian precipitation and 3) examine the causal mechanisms responsible for the increased frequency of Southwest Asia drought in recent decades. The driest November-April seasons during 1948-2012 over Southwest Asia are forced by subsidence and reductions of moisture fluxes as a result of the interaction of the mean flow with anomalous zonally-symmetric high pressure throughout the Northern Hemisphere. The anomalous zonally-symmetric high pressure throughout the Northern Hemisphere occurs simultaneously with cool central and eastern Pacific SST anomalies associated with La Niña and the negative phase of PDV and a warm west Pacific Ocean caused in part by the long-term warming of the west Pacific Ocean. The long-term warming of the Pacific Ocean has driven the regional precipitation declines in recent decades, with the strongest signal occurring over areas bordering the Arabian Sea.

  20. Dating climatic change in hot deserts using desert varnish on meteorite finds

    Science.gov (United States)

    Lee, M. R.; Bland, P. A.

    2003-01-01

    A thin coating of desert varnish occurs on Forrest 009 and Nurina 004, both equilibrated ordinary chondrite (L6) finds from the Nullarbor Plain, Australia. This finely laminated deposit is chemically and petrographically comparable to the varnish found on terrestrial rocks. Forrest 009, which has a terrestrial age of 5.9 kyr, has a 100-130 μm thick coating of desert varnish that has a laterally consistent chemical microstratigraphy comprising a narrow Ba- and Mn-poor lower region, a thick Ba- and Mn-rich central area and a narrow outer zone almost devoid of both cations. The interior of the meteorite contains Fe-oxide and oxyhydroxide veins that have formed by chemical weathering of metals and sulphides. As these veins do not cross-cut the varnish, it must have accreted rapidly relative to the weathering rate of the meteorite. The ≤70 μm thick varnish on Nurina 004, which has a terrestrial age of 33.4 kyr, lacks a consistent chemical microstratigraphy, but it is cross-cut by Fe-oxide and oxyhydroxide veins, some of which have supplied Fe to the varnish. This implies that the chemical weathering rate of Nurina 004's interior was slow in comparison to the accretion rate of the varnish. The petrography and chemical composition of varnish on Forrest 009 indicates that this meteorite may have resided in a relatively humid environment for most of its 5.9 kyr terrestrial history and that the Nullarbor recently became more arid. This conclusion supports results from an analysis of Fe-bearing weathering products in the interior of the meteorite by Mössbauer spectroscopy, which also indicate that Forrest 009 experienced an early period of rapid weathering under relatively humid conditions. The petrography of varnish on Nurina 004 shows that the interior of the meteorite weathered relatively slowly, probably because it fell during an arid time, which is again in agreement with previous Mössbauer spectroscopy results. Results from both meteorites are in agreement with

  1. Advance agriculture in the desert:the Israeli case story

    Institute of Scientific and Technical Information of China (English)

    Raanan Katzir

    2015-01-01

    The Israeli Desert constitutes 60%of the country's total area. Regional annual precipitation is 100–200 mm and evapora-tion reaches 2,500 mm. Traditional desert agriculture of rain fed wheat and sheep, goat and camels grazing is common. Despite the harsh climate conditions, advance agriculture is concentrated in foci where water resources exist. Desert ag-riculture takes advantage of the winter (October–April) due to a mild climate season for growing vegetables, flowers, herbs and fruit which are mostly exported to European countries. The key factor is the sustainable management of the local natural resources. The regional research and development (R&D) system is generating adequate local knowledge and technologies. The most important key factor is developing water resources, and using irrigation saving water systems such as drip irrigation. Technologies of protected agriculture such as greenhouses and plastic tunnels are used. The unfit desert soil is substitute by sand and artificial growing media. For gaining market purposes, introduction of botanical species was implemented for various flowers and vegetable varieties, avocado, pitaya, and jojoba. Controlled drip irrigation and drainage helps to solve salinity problems. Integrated Pest Management (IPM) is used to overcome plant protection issues. Advance raising of milking cows was developed by using reduction heat stress methods. Tilapia are raised in open ponds and greenhouse ponds, and ostriches adapted to desert conditions were introduced. On the southern Judean hills where precipitation is 250 mm, through soil conservation and rain harvesting, significant afforestation is changing the desert scenery. The human factor on this process such as farmers, agricultural extension agents and research scientists is the leading factor.

  2. 76 FR 45606 - Desert Renewable Energy Conservation Plan, Habitat Conservation Plan and Possible Land Use Plan...

    Science.gov (United States)

    2011-07-29

    ... Bureau of Land Management Fish and Wildlife Service Desert Renewable Energy Conservation Plan, Habitat... Policy Act (NEPA) of 1969, as amended, for the proposed Desert Renewable Energy Conservation Plan (DRECP... proposed Desert Renewable Energy Conservation Plan (DRECP). The EIS will be a joint Environmental...

  3. 40 CFR 81.167 - Southeast Desert Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Air Quality Control Regions § 81.167 Southeast Desert Intrastate Air Quality Control Region. The Southeast Desert Intrastate Air Quality Control Region (California) consists of the territorial area... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Southeast Desert Intrastate...

  4. 76 FR 29153 - Revisions to the California State Implementation Plan, Mojave Desert Air Quality Management District

    Science.gov (United States)

    2011-05-20

    ... taking direct final action to approve revisions to the Mojave Desert Air Quality Management District... approving with the dates that they were adopted by the Mojave Desert Air Quality Management District (MDAQMD... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Mojave Desert Air...

  5. Lizard burrows provide thermal refugia for larks in the Arabian desert

    NARCIS (Netherlands)

    Williams, JB; Tieleman, BI; Shobrak, M

    1999-01-01

    A common perception is that desert birds experience greater extremes of heat and aridity than their mammalian counterparts, in part, because birds do not use burrows as a refuge from the desert environment. We report observations of Dunn's Larks (Eremalauda dunni), Bar-tailed Desert Larks (Ammomanes

  6. Mid-to-Late Holocene Hydrologic Variability in the Southeastern Mojave Desert Using Sediments from Ford Lake

    Science.gov (United States)

    Mayer, S. A.; Kirby, M. E.; Anderson, W. T., Jr.; Stout, C.; Palermo, J. A.

    2015-12-01

    The focal point of most lacustrine studies in the Mojave National Preserve (MNP) to date has been on lakes fed by the Mojave River. The source of the Mojave River is found on the northern flank of the San Bernardino Mountains. Consequently, the lakes that receive these waters are predominantly responding to the winter-only coastal southwest United States climate (e.g., Kirby et al., 2015 - Silver Lake); to a lesser degree, these lakes are also influenced by the Mojave's bimodal winter/summer climate. Ford Lake, located in the southeastern Mojave Desert is a small closed basin lake with its drainage basin located exclusively within the Mojave Desert. Therefore, sediment collected from Ford Lake contains a 100% Mojave-only climate signal. A 2.18 m sediment core was collected from the lake's depocenter in May 2015. Sediment analyses at 1 cm contiguous intervals include: magnetic susceptibility (MS), percent total organic matter, percent total carbonate content, and grain size analysis; C:N ratios, C and N isotope (δ13C and δ15N) analyses, and macrofossil counts are determined at 2 cm intervals. The site's age model is based on accelerator mass spectrometry (AMS) radiocarbon ages from discrete organic macrofossils or bulk organic carbon. To deconvolve the coastal climate, winter-only signal from the Mojave-only climate signal the data from Ford Lake will be compared to one Mojave River fed lake (Silver) and several southern California lakes (Lower Bear, Lake Elsinore, Dry Lake, and Zaca Lake). Our results will be analyzed in the context of climate forcings such as insolation and ocean - atmosphere dynamics.

  7. Recovery of compacted soils in Mojave Desert ghost towns.

    Science.gov (United States)

    Webb, R.H.; Steiger, J.W.; Wilshire, H.G.

    1986-01-01

    Residual compaction of soils was measured at seven sites in five Mojave Desert ghost towns. Soils in these Death Valley National Monument townsites were compacted by vehicles, animals, and human trampling, and the townsites had been completely abandoned and the buildings removed for 64 to 75 yr. Recovery times extrapolated using a linear recovery model ranged from 80 to 140 yr and averaged 100 yr. The recovery times were related to elevation, suggesting freeze-thaw loosening as an important factor in ameliorating soil compaction in the Mojave Desert. -from Authors

  8. Researchers Reveal Ecological Roles of Biological Soil Crusts in Desert

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Biological soil crust is a complex organic integrity of cyanobacteria, green algae, lichens and mosses, fungi, and other bacteria. This is a common and widespread phenomenon in desert areas all over the world. Biologically,this kind of soil crust differs a lot from physical ones in terms of physical and chemical properties, and become important biological factors in vegetation succession. Despite its unassuming appearance, the crust plays a significant role in the desert ecosystem, involving the process of soil formation, stability and fertility,the prevention of soil erosion by water or wind, the increased possibility of vascular plants colonization, and the stabilization of sand dunes.

  9. Palynology in a polar desert, eastern North Greenland

    DEFF Research Database (Denmark)

    Funder, Svend Visby; Abrahamsen, Niels

    1988-01-01

    history back to c. 7,000 years calBP (6,000 years convBP) in this·extreme environment, which presents the coldest thermal regime where vascular plants can grow. The diagram shows that polar desert developed from sparse high arctic tundra at c. 4,300 years calBP (3,900 years convBP), owing...... to reduced summer heat. Also adjacent parts of high arctic Greenland, Canada and Svalbard suffered environmental decline, and polar deserts- presently restricted to a narrow fringe of land at the shores of the Arctic Ocean-were even more restricted before this time. Like other arctic vegetation types, polar...

  10. 2005/2006 Southwest Florida Water Management District (SWFWMD) Lidar: Peace River South (including Carter Creek)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) LAS dataset is a survey of select areas within Southwest Florida. These data were produced for the Southwest Florida Water...

  11. Does subterranean flow initiate mud banks off the southwest coast of India?

    Digital Repository Service at National Institute of Oceanography (India)

    Balachandran, K.K.

    Coastal waters off the southwest coast of India draw special attention because of the occurrence of mud banks at certain locations during southwest monsoon period. The present study puts forward a hypothesis of a subterranean flow, which could be a...

  12. Landscape practices and representations in eighteenth-century Dongchuan, Southwest China

    NARCIS (Netherlands)

    Huang, Fei

    2012-01-01

    My doctorial thesis, entitled ‘Landscape Practices and Representations in Dongchuan, Southwest Eighteenth-Century China’, focuses on the interdisciplinary study of landscape, space and architecture in Southwest eighteenth-century China. Through intensive archival research and contemporary ethnograph

  13. 2005 Southwest Florida Water Management District (SWFWMD) Lidar: Little Manatee District

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) LAS dataset is a survey of select areas within Southwest Florida. These data were produced for the Southwest Florida Water...

  14. Determination of actual evapotranspiration and transpiration in desert sand dunes (Negev Desert) using different approaches

    Institute of Scientific and Technical Information of China (English)

    Thomas Littmann; Maik Veste

    2006-01-01

    In an arid environment, especially in sandy areas where surface runoff is of no practical importance in the hydrological budget, it is rainfall, dewfall and evapotranspiration that become the most important variables. To assess actual evapotranspiration,several methods (flux-gradient, BREB, eddy correlation) were applied to data from the Nizzana experimental site in the northwestern Negev Desert. Additionally, a model specifically designed for arid environments is introduced in this paper. This zero plane model shows the most reasonable results compared with the other methods, which overestimate evapotranspiration to a large degree. It is shown that plant transpiration is the dominant process in total evapotranspiration while advective processes do not play a major role in the near-ground boundary layer, although the study area is influenced by a sea breeze. Actual transpiration of Artemisia monosperma was measured in a field experiment to validate the calculated evapotranspiration. The vegetation contributed 41% of the calculated total evapotranspiration in a single month.

  15. Distribution of Natural Perchlorate in a Desert Landscape-Amargosa Desert Research Site, Nevada

    Science.gov (United States)

    Andraski, B. J.; Jackson, A.; Welborn, T.; Stonestrom, D. A.; Bohlke, J. K.

    2011-12-01

    Knowledge of perchlorate (ClO4-) occurrence is important due to health concerns, evolving groundwater-protection regulations, and for forensic investigations. The distribution of natural ClO4- is being studied at the U.S. Geological Survey's Amargosa Desert Research Site to improve understanding of factors that influence its accumulation and cycling in a desert landscape. The first part of the study evaluated the effect of plants on shallow (0-30 cm) soil concentrations in three settings-shoulder slope, footslope, and valley floor; samples were collected adjacent to plants and in interspaces 2.5-5 m from plants. For the valley-floor, there was a 17-fold decrease between interspace (5.0 μg/kg) and plant-adjacent (0.3 μg/kg) ClO4- concentrations. Chloride (Cl-) concentrations also showed large differences and indicated salt accumulation beneath the interspace desert pavement, but localized leaching adjacent to plants. For the shoulder and footslope, differences between interspace and plant-adjacent ClO4- concentrations were smaller (two fold on average) and inverted (interspace 2.0 μg/kg; plant-adjacent 3.8 μg/kg), and differences between interspace and plant-adjacent Cl- were negligible. Shoulder and footslope indications of a localized increase in ClO4- adjacent to plants suggest a cyclic mechanism of plant uptake, bioaccumulation, and leaf drop. The second part of the study examined ClO4- variability across a 9-ha hillslope. Data first were analyzed by assigning each sampling point to one of three elevation bands-upper, middle, or lower. Soil and plant data both showed trends of increasing ClO4- with decreasing elevation. Concentrations were, for soil (μg/kg): upper (1.6) middle (3.9) > lower (3.6). Multiple-linear regression analyses also were used to explore the relative importance of soil, plant, and terrain variables that influenced ClO4- concentrations across the hillslope. Important explanatory variables for soil ClO4- are land-surface elevation and

  16. Rehabilitation and Sustainable Use Pattern of Rocky-desertified Land in Southwest China's Poverty-stricken Karst Mountainous Areas——A Case Study in Benggu Township, Xichou County, Yunnan, China

    Institute of Scientific and Technical Information of China (English)

    YANG Zisheng; LIU Yansui; BAO Guangjing; LI Zhiguo; HE Yimei

    2006-01-01

    The rocky desert in a karst area directly causes the lack of soil, water and forest, hence leading to the poverty there. In 1990, the villagers from the Muzhe Village in Benggu Township, Xichou County,Yunnan declared a war against rocky desert in an attempt to ask the fields for more yields. They invented a distinctive land rehabilitation and sustainable use pattern called "transforming heaven and earth" that had been practiced in Southwest China's karst areas. The key mechanism of the pattern was to develop terraced fields with well conserved soil,water and fertility by exploding rocks in the fields,building stone walls, gathering more soil, and improving soil quality and productivity for the fields in combination with building of irrigation facilities and roads, as well as with forestation and agriculture structure adjustment. The purpose of the pattern was to alleviate poverty in the karst areas by improving soil productivity and promoting agricultural development. A typical area was studied with the help of Participatory Rural Appraisal (PRA) and the pattern was carried out there for fifteen years, have produced excellent ecological benefits and good economic benefits. Its application in the area approved that it was a sustainable land use pattern for rocky desert areas.

  17. Multiple factors affect a population of Agassiz's desert tortoise (Gopherus agassizii) in the Northwestern Mojave Desert

    Science.gov (United States)

    Berry, Kristin H.; Yee, Julie L.; Coble, Ashley A.; Perry, William M.; Shields, Timothy A.

    2013-01-01

    Numerous factors have contributed to declines in populations of the federally threatened Agassiz's Desert Tortoise (Gopherus agassizii) and continue to limit recovery. In 2010, we surveyed a low-density population on a military test facility in the northwestern Mojave Desert of California, USA, to evaluate population status and identify potential factors contributing to distribution and low densities. Estimated densities of live tortoises ranged spatially from 1.2/km2 to 15.1/km2. Although only one death of a breeding-age tortoise was recorded for the 4-yr period prior to the survey, remains of 16 juvenile and immature tortoises were found, and most showed signs of predation by Common Ravens (Corvus corax) and mammals. Predation may have limited recruitment of young tortoises into the adult size classes. To evaluate the relative importance of different types of impacts to tortoises, we developed predictive models for spatially explicit densities of tortoise sign and live tortoises using topography (i.e., slope), predators (Common Raven, signs of mammalian predators), and anthropogenic impacts (distances from paved road and denuded areas, density of ordnance fragments) as covariates. Models suggest that densities of tortoise sign increased with slope and signs of mammalian predators and decreased with Common Ravens, while also varying based on interaction effects involving these predictors as well as distances from paved roads, denuded areas, and ordnance. Similarly, densities of live tortoises varied by interaction effects among distances to denuded areas and paved roads, density of ordnance fragments, and slope. Thus multiple factors predict the densities and distribution of this population.

  18. Retail Demand Response in Southwest Power Pool

    Energy Technology Data Exchange (ETDEWEB)

    Bharvirkar, Ranjit; Heffner, Grayson; Goldman, Charles

    2009-01-30

    In 2007, the Southwest Power Pool (SPP) formed the Customer Response Task Force (CRTF) to identify barriers to deploying demand response (DR) resources in wholesale markets and develop policies to overcome these barriers. One of the initiatives of this Task Force was to develop more detailed information on existing retail DR programs and dynamic pricing tariffs, program rules, and utility operating practices. This report describes the results of a comprehensive survey conducted by LBNL in support of the Customer Response Task Force and discusses policy implications for integrating legacy retail DR programs and dynamic pricing tariffs into wholesale markets in the SPP region. LBNL conducted a detailed survey of existing DR programs and dynamic pricing tariffs administered by SPP's member utilities. Survey respondents were asked to provide information on advance notice requirements to customers, operational triggers used to call events (e.g. system emergencies, market conditions, local emergencies), use of these DR resources to meet planning reserves requirements, DR resource availability (e.g. seasonal, annual), participant incentive structures, and monitoring and verification (M&V) protocols. Nearly all of the 30 load-serving entities in SPP responded to the survey. Of this group, fourteen SPP member utilities administer 36 DR programs, five dynamic pricing tariffs, and six voluntary customer response initiatives. These existing DR programs and dynamic pricing tariffs have a peak demand reduction potential of 1,552 MW. Other major findings of this study are: o About 81percent of available DR is from interruptible rate tariffs offered to large commercial and industrial customers, while direct load control (DLC) programs account for ~;;14percent. o Arkansas accounts for ~;;50percent of the DR resources in the SPP footprint; these DR resources are primarily managed by cooperatives. o Publicly-owned cooperatives accounted for 54percent of the existing DR resources

  19. Dynamic changes of a typical linear dune in the Tengger Desert

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The dynamical processes of a typical linear dune including morphological features, dune ridge swing range and crest height were investigated at different monitoring periods in the hinterland of Tengger Desert. The results indicated that the development of linear dune depends on not only the northwesterly prevailing wind, but also the winds from northeast and southwest. The dune ridge swayed along its fundamental strike and took on an eastward movement gradually. The original dune strike was NW70° on August 3, 1994, and then changed to NE15° on April 21, 2001. The dune crest increased by 1.8 m longitudinally, which manifested strong wind-blown sand activities in this region. Wind erosion frequently occured at the bottom of sand dune, while sand accumulation appeared on its mid-upper section. The mean wind erosion depth was 25 cm on the bottom of linear dune and the height difference of the control points on the dune’s ridge was 1.13 m. Although the linear dune swayed laterally, the horizontal displacement of its ridge moved eastward 5.8 m averagely. The swing range of the dune crest line is very distinct, with a maximum value of 13.2 m. The highest site on the K-profile swayed on both sides of the dune ridge and the heights were 19.88 m at the control point K5, 19.61 m at K6 and 19.05 m at K7, respectively. The results indicated that the lateral swing of the linear dune was distinct under the northwesterly wind and it moved toward east gradually.

  20. Dynamic changes of a typical linear dune in the Tengger Desert

    Institute of Scientific and Technical Information of China (English)

    KeCun ZHANG; KenJi KAI; JianJun QU; YuQuan LING; QingHe NIU

    2010-01-01

    The dynamical processes of a typical linear dune including morphological features,dune ridge swing range and crest height were investigated at different monitoring periods in the hinterland of Tengger Desert.The results indicated that the development of linear dune depends on not only the northwesterly prevailing wind,but also the winds from northeast and southwest.The dune ridge swayed along its fundamental strike and took on an eastward movement gradually.The original dune strike was NW70° on August 3,1994,and then changed to NE15° on April 21,2001.The dune crest increased by 1.8 m longitudinally,which manifested strong wind-blown sand activities in this region.Wind erosion frequently occured at the bottom of sand dune,while sand accumulation appeared on its mid-upper section.The mean wind erosion depth was 25 cm on the bottom of linear dune and the height difference of the control points on the dune's ridge was 1.13 m.Although the linear dune swayed laterally,the horizontal displacement of its ridge moved eastward 5.8 m averagely.The swing range of the dune crest line is very distinct,with a maximum value of 13.2 m.The highest site on the K-profile swayed on both sides of the dune ridge and the heights were 19.88 m at the control point K2,19.61 m at K6 and 19.05 m at K7,respectively.The results indicated that the lateral swing of the linear dune was distinct under the northwesterly wind and it moved toward east gradually.

  1. Environmental Sequencing of Biotic Components of Dust in the Chihuahuan Desert

    Science.gov (United States)

    Walsh, E.; Gill, T. E.; Rivas, J. A., Jr.; Leung, M. Y.; Mohl, J.

    2015-12-01

    A growing number of studies mark the role of wind in dispersing biota. Most of these approaches have used traditional methods to assess taxonomic diversity. Here we used next generation sequencing to characterize microbiota in dust collected from the Chihuahuan Desert. Atmospheric dust was collected during events during 2011-2014 using dry deposition collectors placed at two sites in El Paso Co., TX. In parallel experiments, we rehydrated subsamples of dust and conducted PCR amplifications using conserved primers for 16S and 18S ribosomal genes. Sequenced reads were de-multiplexed, quality filtered, and processed using QIIME. Taxonomy was assigned based on pairwise identity using BLAST for microbial eukaryotes. All samples were rarefied to a set number of sequences per sample prior to downstream analyses. Bioinformatic analysis of four of the dust samples yielded a diversity of biota, including zooplankton, bacteria, fungi, algae, and protists, but fungi predominate (>90% of both 10K and 3K reads). In our rehydrations of dust samples from the U.S. southwest nematodes, gastrotrichs, tardigrades, monogonont and bdelloid rotifers, branchiopods and numerous ciliates have been recovered. Variability in genetic diversity among samples is based, in part, on the source and extent of the particular dust event. We anticipate the same patterns will be seen in the complete data set. These preliminary results indicate that wind is a major transporter of not only fungi, bacteria and other unicellular organisms but may also be important in shaping the distribution patterns of multi-cellular organisms such as those that inhabit aquatic environments in the arid southwestern US.

  2. Structural evolution of the Abu Gharadig field area, Northern Western Desert, Egypt

    Science.gov (United States)

    El Gazzar, A. M.; Moustafa, A. R.; Bentham, P.

    2016-12-01

    Discovered in 1969, the Abu Gharadig (AG) Field was the first large hydrocarbon discovery in the Abu Gharadig Basin of the Western Desert of Egypt. Oil production began in 1973, with gas brought into production in 1975. The field produces mainly from upper Cretaceous clastic reservoirs. The AG Basin is an E-W trending intracratonic rift basin, about 330 km long and 50-75 km wide. It was initially formed as a large half graben basin during the Jurassic time in response to Tethyan rifting and continued to subside throughout the Cretaceous time. The half graben was subsequently inverted during the Late Cretaceous as part of the Syrian Arc deformation which affected northern Egypt. The Mid-Basin Arch, the AG Anticline, and the Mubarak High are three NE-SW oriented main inversion anticlines located within the AG Basin and are controlled by inversion of pre-existing Jurassic rift faults. The AG Anticline has an overall NE-SW orientation with a gentle plunge towards the NE and SW. It is locally bounded by two NE-SW-trending inverted faults on the southwest and northeast, accounting for the asymmetry of the anticline. Reverse offset of Cretaceous horizons is obvious at these inverted faults. Fault propagation folding is developed above the tips of the inverted faults at the Late Cretaceous Abu Roash and Khoman Formations. Based on thickness changes and stratigraphic relationships, inversion started during the Santonian time and continued into the Campanian-Maastrichtian. Inversion continued during deposition of the Paleocene-Middle Eocene Apollonia Formation and the Late Eocene-Oligocene Dabaa Formation.

  3. Carbon, water, and energy fluxes in a semiarid cold desert grassland during and following multiyear drought

    Science.gov (United States)

    Bowling, David R.; Bethers-Marchetti, S.; Lunch, C.K.; Grote, E.E.; Belnap, J.

    2010-01-01

    The net exchanges of carbon dioxide, water vapor, and energy were examined in a perennial Colorado Plateau grassland for 5 years. The study began within a multiyear drought and continued as the drought ended. The grassland is located near the northern boundary of the influence of the North American monsoon, a major climatic feature bringing summer rain. Following rain, evapotranspiration peaked above 8 mm d-1 but was usually much smaller (2-4 mm d-1). Net productivity of the grassland was low compared to other ecosystems, with peak hourly net CO2 uptake in the spring of 4 (mu or u)mol m-2 s-1 and springtime carbon gain in the range of 42 + or - 11 g C m-2 (based on fluxes) to 72 + or - 55 g C m-2 (based on carbon stocks; annual carbon gain was not quantified). Drought decreased gross ecosystem productivity (GEP) and total ecosystem respiration, with a much larger GEP decrease. Monsoon rains led to respiratory pulses, lasting a few days at most, and only rarely resulted in net CO2 gain, despite the fact that C4 grasses dominated plant cover. Minor CO2 uptake was observed in fall following rain. Spring CO2 uptake was regulated by deep soil moisture, which depended on precipitation in the prior fall and winter. The lack of CO2 uptake during the monsoon and the dependence of GEP on deep soil moisture are in contrast with arid grasslands of the warm deserts. Cold desert grasslands are most likely to be impacted by future changes in winter and not summer precipitation.

  4. Carbon, water, and energy fluxes in a semiarid cold desert grassland during and following multiyear drought

    Science.gov (United States)

    Bowling, D. R.; Bethers-Marchetti, S.; Lunch, C. K.; Grote, E. E.; Belnap, J.

    2010-12-01

    The net exchanges of carbon dioxide, water vapor, and energy were examined in a perennial Colorado Plateau grassland for 5 years. The study began within a multiyear drought and continued as the drought ended. The grassland is located near the northern boundary of the influence of the North American monsoon, a major climatic feature bringing summer rain. Following rain, evapotranspiration peaked above 8 mm d-1 but was usually much smaller (2-4 mm d-1). Net productivity of the grassland was low compared to other ecosystems, with peak hourly net CO2 uptake in the spring of 4 μmol m-2 s-1 and springtime carbon gain in the range of 42 ± 11 g C m-2 (based on fluxes) to 72 ± 55 g C m-2 (based on carbon stocks; annual carbon gain was not quantified). Drought decreased gross ecosystem productivity (GEP) and total ecosystem respiration, with a much larger GEP decrease. Monsoon rains led to respiratory pulses, lasting a few days at most, and only rarely resulted in net CO2 gain, despite the fact that C4 grasses dominated plant cover. Minor CO2 uptake was observed in fall following rain. Spring CO2 uptake was regulated by deep soil moisture, which depended on precipitation in the prior fall and winter. The lack of CO2 uptake during the monsoon and the dependence of GEP on deep soil moisture are in contrast with arid grasslands of the warm deserts. Cold desert grasslands are most likely to be impacted by future changes in winter and not summer precipitation.

  5. Silica in a Mars analog environment: Ka u Desert, Kilauea Volcano, Hawaii

    Science.gov (United States)

    Seelos, K.D.; Arvidson, R. E.; Jolliff, B.L.; Chemtob, S.M.; Morris, R.V.; Ming, D. W.; Swayze, G.A.

    2010-01-01

    Airborne Visible/Near-Infrared Imaging Spectrometer (AVIRIS) data acquired over the Ka u Desert are atmospherically corrected to ground reflectance and used to identify the mineralogic components of relatively young basaltic materials, including 250-700 and 200-400 year old lava flows, 1971 and 1974 flows, ash deposits, and solfatara incrustations. To provide context, a geologic surface units map is constructed, verified with field observations, and supported by laboratory analyses. AVIRIS spectral endmembers are identified in the visible (0.4 to 1.2 ??m) and short wave infrared (2.0 to 2.5 ??m) wavelength ranges. Nearly all the spectral variability is controlled by the presence of ferrous and ferric iron in such minerals as pyroxene, olivine, hematite, goethite, and poorly crystalline iron oxides or glass. A broad, nearly ubiquitous absorption feature centered at 2.25 ??m is attributed to opaline (amorphous, hydrated) silica and is found to correlate spatially with mapped geologic surface units. Laboratory analyses show the silica to be consistently present as a deposited phase, including incrustations downwind from solfatara vents, cementing agent for ash duricrusts, and thin coatings on the youngest lava flow surfaces. A second, Ti-rich upper coating on young flows also influences spectral behavior. This study demonstrates that secondary silica is mobile in the Ka u Desert on a variety of time scales and spatial domains. The investigation from remote, field, and laboratory perspectives also mimics exploration of Mars using orbital and landed missions, with important implications for spectral characterization of coated basalts and formation of opaline silica in arid, acidic alteration environments. Copyright 2010 by the American Geophysical Union.

  6. Tradeoffs and Synergies between biofuel production and large solar infrastructure in deserts.

    Science.gov (United States)

    Ravi, Sujith; Lobell, David B; Field, Christopher B

    2014-01-01

    Solar energy installations in deserts are on the rise, fueled by technological advances and policy changes. Deserts, with a combination of high solar radiation and availability of large areas unusable for crop production are ideal locations for large solar installations. However, for efficient power generation, solar infrastructures use large amounts of water for construction and operation. We investigated the water use and greenhouse gas (GHG) emissions associated with solar installations in North American deserts in comparison to agave-based biofuel production, another widely promoted potential energy source from arid systems. We determined the uncertainty in our analysis by a Monte Carlo approach that varied the most important parameters, as determined by sensitivity analysis. We considered the uncertainty in our estimates as a result of variations in the number of solar modules ha(-1), module efficiency, number of agave plants ha(-1), and overall sugar conversion efficiency for agave. Further, we considered the uncertainty in revenue and returns as a result of variations in the wholesale price of electricity and installation cost of solar photovoltaic (PV), wholesale price of agave ethanol, and cost of agave cultivation and ethanol processing. The life-cycle analyses show that energy outputs and GHG offsets from solar PV systems, mean energy output of 2405 GJ ha(-1) year(-1) (5 and 95% quantile values of 1940-2920) and mean GHG offsets of 464 Mg of CO2 equiv ha(-1) year(-1) (375-562), are much larger than agave, mean energy output from 206 (171-243) to 61 (50-71) GJ ha(-1) year(-1) and mean GHG offsets from 18 (14-22) to 4.6 (3.7-5.5) Mg of CO2 equiv ha(-1) year(-1), depending upon the yield scenario of agave. Importantly though, water inputs for cleaning solar panels and dust suppression are similar to amounts required for annual agave growth, suggesting the possibility of integrating the two systems to maximize the efficiency of land and water use to produce

  7. Bilingual Education in Southwest China: A Yingjiang Case

    Science.gov (United States)

    Wang, Ge

    2011-01-01

    Yingjiang is a frontier county in southwest Yunnan, China, with distinctive ethnic and cultural diversity. Bilingual education (BE) has been a prominent feature in Yingjiang since the 1950s due to supportive policies and measures at various levels. BE in Yingjiang developed so well in the 1980s that a bilingual school was awarded the title of…

  8. Benthic fauna of southwest and southeast coasts of India

    Digital Repository Service at National Institute of Oceanography (India)

    Devi, K.S.; Sheba, P.; Balasubramanian, T.; Venugopal, P.; Sankaranarayanan, V.N.

    of substratum viz. clayey silt, clayey sand, silty clay, sandy silt and sandy were noticed from different stations along southwest coast. But sand percentage dominated along southeast coast. The pooled mean organic matter percentage varied from 0.08 to 4...

  9. Evidence of Upwelling along Peninsular Malaysia during Southwest Monsoon

    DEFF Research Database (Denmark)

    Daryabor, Farshid

    2015-01-01

    Upwelling off the east coast of Peninsular Malaysia (PM) was detected from recent cruise data collected during the southwest monsoon. Thermocline lifting was observed at 104˚E from a number of parallel transects. To confirm the presence of upwelling, satellite remote sensing data were used...

  10. Morphological systematics of Serapias L. (Orchidaceae) in Southwest Europe

    NARCIS (Netherlands)

    Venhuis, C.; Venhuis, P.; Oostermeijer, J.G.B.; van Tienderen, P.H.

    2007-01-01

    Abstract. We measured morphological characters and relative DNA contents to assess variation and phylogenetic relationships among Serapias species in three populations of each of the 10 putative taxa that occur in Southwest Europe. DNA contents indicated diploidy for most species, except for tetrapl

  11. Assessing Crop Vulnerability to Climate Change: A Southwest Perspective

    Science.gov (United States)

    The USDA Southwest Regional Climate Hub is one of ten Climate Hubs and Sub-hubs established in 2014. The Hub region includes Arizona, California (partnering with the California Sub-Hub), Nevada, New Mexico and Utah.  Beyond the mainland States, the SW hub also serves Hawaii and the US affiliated Pac...

  12. Nontuberculous mycobacteria: incidence in Southwest Ireland from 1987 to 2000.

    LENUS (Irish Health Repository)

    Kennedy, M P

    2012-02-03

    SETTING: The Southwest of Ireland (Counties Cork and Kerry) 1987-2000, average population 549,500. OBJECTIVE: Nontuberculous mycobacteria (NTM) cause significant morbidity worldwide and the study of epidemiology and characteristics helps in their prevention and treatment. This study was performed to determine the incidence of NTM disease in comparison to Mycobacterium tuberculosis (M. tuberculosis) and Mycobacterium bovis (M. bovis) in Southwest Ireland, over the above time period. DESIGN: A retrospective study was carried out in all human isolates of NTM, M. tuberculosis and M. bovis between 1987 and 2000, in the Southwest Region of Ireland. RESULTS: The mean incidence of NTM (0.4\\/100,000 population) has risen since 1995, principally of pulmonary Mycobacterium avium intracellulare complex (MAC). The annual incidence of M. tuberculosis in humans over 14 years in the same region was 971\\/100,000 population with a significant reduction since 1994 and M. bovis remained constant at 0.5\\/100,000 population. CONCLUSION: The increasing incidence of disease causing NTM noted in Southwest Ireland reflects global data and is surmised to be due to an ageing population, increased incidence related to chronic fibrotic lung disease, and environmental mycobacterial factors.

  13. Morphology of the Somali Current System during the Southwest Monsoon,

    Science.gov (United States)

    wind stress curl. The two-gyre system collapse is highly correlated with a decrease in the westerly component of the equatorial wind stress . The...circulation patterns are strongly influenced by the gradient of the wind stress curl, as well as by the curl itself. The transition from southwest to

  14. Radiotelemetry Study of a Desert Tortoise Population: Sand Hill Training Mea, Marine Corps Air Ground Combat Center, Twentynine Palms, California

    Science.gov (United States)

    1998-05-01

    monitoring landscape integrity and ecological viability. Desert Tortoise Ecology and Behavior The desert tortoise is a herbivorous reptile ...specialized invertebrates. The burrows provide permanent homes, escape from predators, thermoregulation and maintenance of homeostasis, and hiberna...desert reptiles has long been appreciated (Cowles and Bogert 1944). The importance of burrow microclimates to desert vertebrates and invertebrates, and

  15. Desert soil collection at the JPL soil science laboratory

    Science.gov (United States)

    Blank, G. B.; Cameron, R. E.

    1969-01-01

    Collection contains desert soils and other geologic materials collected from sites in the United States and foreign countries. Soils are useful for test purposes in research related to extraterrestrial life detection, sampling, harsh environmental studies, and determining suitable areas for training astronauts for lunar exploration.

  16. Sand harm in taklimakan Desert highway and sand control

    Institute of Scientific and Technical Information of China (English)

    HANZhiwen; WANGTao; SUNQingwei; DONGZhibao; WANGXunming

    2003-01-01

    Reputed as a wonderful achievement of the world’s highway construction history,the Taklimakan Desert highway is nor facing serious sand drift encroachment problems due to its 447-km-long passage of sand sea consisting of crescent dunes,barchan chains,compound transverse dune ridges and complex megadunes.To solve some technical problems in the protection of the highway from sang drift encroachment,desert experts have been conducting the theoretical and applied studies on sand movement laws;causes,severities and time-space differentiation of sand drift damages;and control ways including mechanical,chemical and biological measures.In this paper the authors give an overall summry on the research contents and recent progress in the control of sand drift damages in China and hold that the theoretical researc results and practices in the prevention of sand drift encroachment on the cross-desert highway represnt a breakthrough and has an cpoch-making significance.Since the construction of protective forest along the cross-desert highway requires large amount of ground water,what will be its environmental consequence and whether it can effectively halt sand drift encroachment on the highway forever are the questions to be studied urgently.

  17. AMPHIBIAN DECLINES AND ENVIRONMENTAL CHANGE IN THE EASTERN "MOJAVE DESERT"

    Science.gov (United States)

    A number of amphibian species historically inhabited sparsely distributed wetlands in the Mojave Desert, USA, habitats that have been dramatically altered or eliminated as a result of human activities. The population status and distribution of amphibians were investigated in a 20...

  18. Dynamic response of desert wetlands to abrupt climate change.

    Science.gov (United States)

    Springer, Kathleen B; Manker, Craig R; Pigati, Jeffrey S

    2015-11-24

    Desert wetlands are keystone ecosystems in arid environments and are preserved in the geologic record as groundwater discharge (GWD) deposits. GWD deposits are inherently discontinuous and stratigraphically complex, which has limited our understanding of how desert wetlands responded to past episodes of rapid climate change. Previous studies have shown that wetlands responded to climate change on glacial to interglacial timescales, but their sensitivity to short-lived climate perturbations is largely unknown. Here, we show that GWD deposits in the Las Vegas Valley (southern Nevada, United States) provide a detailed and nearly complete record of dynamic hydrologic changes during the past 35 ka (thousands of calibrated (14)C years before present), including cycles of wetland expansion and contraction that correlate tightly with climatic oscillations recorded in the Greenland ice cores. Cessation of discharge associated with rapid warming events resulted in the collapse of entire wetland systems in the Las Vegas Valley at multiple times during the late Quaternary. On average, drought-like conditions, as recorded by widespread erosion and the formation of desert soils, lasted for a few centuries. This record illustrates the vulnerability of desert wetland flora and fauna to abrupt climate change. It also shows that GWD deposits can be used to reconstruct paleohydrologic conditions at millennial to submillennial timescales and informs conservation efforts aimed at protecting these fragile ecosystems in the face of anthropogenic warming.

  19. Dynamic response of desert wetlands to abrupt climate change

    Science.gov (United States)

    Springer, Kathleen; Manker, Craig; Pigati, Jeff

    2015-01-01

    Desert wetlands are keystone ecosystems in arid environments and are preserved in the geologic record as groundwater discharge (GWD) deposits. GWD deposits are inherently discontinuous and stratigraphically complex, which has limited our understanding of how desert wetlands responded to past episodes of rapid climate change. Previous studies have shown that wetlands responded to climate change on glacial to interglacial timescales, but their sensitivity to short-lived climate perturbations is largely unknown. Here, we show that GWD deposits in the Las Vegas Valley (southern Nevada, United States) provide a detailed and nearly complete record of dynamic hydrologic changes during the past 35 ka (thousands of calibrated 14C years before present), including cycles of wetland expansion and contraction that correlate tightly with climatic oscillations recorded in the Greenland ice cores. Cessation of discharge associated with rapid warming events resulted in the collapse of entire wetland systems in the Las Vegas Valley at multiple times during the late Quaternary. On average, drought-like conditions, as recorded by widespread erosion and the formation of desert soils, lasted for a few centuries. This record illustrates the vulnerability of desert wetland flora and fauna to abrupt climate change. It also shows that GWD deposits can be used to reconstruct paleohydrologic conditions at millennial to submillennial timescales and informs conservation efforts aimed at protecting these fragile ecosystems in the face of anthropogenic warming.

  20. Ecophysiological responses of Chihuahuan desert grasses to fire.

    Science.gov (United States)

    To better understand the effects of fire in the Chihuahuan desert, gas exchange characteristics of two dominant grass species, Bouteloua eriopoda and Aristida purpurea, and soil nitrogen availability were studied in response to prescribed fire at the Jornada Experimental Range in southern New Mexico...

  1. Ecological and evolutionary physiology of desert birds : A progress report

    NARCIS (Netherlands)

    Williams, JB; Tieleman, BI

    2002-01-01

    The adaptive significance of mechanisms of energy and water conservation among species of desert rodents, which avoid temperature extremes by remaining within a burrow during the day, is well established. Conventional wisdom holds that arid-zone birds, diurnal organisms that endure the brunt of thei

  2. Characteristics and source of black carbon aerosol over Taklimakan Desert

    Institute of Scientific and Technical Information of China (English)

    FU; S.Joshua

    2010-01-01

    Black carbon(BC) and PM10 in the center of the Taklimakan Desert were online monitored in the whole year of 2007.In addi-tion,TSP samples were also synchronously daily collected by medium-volume samplers with Whatman41 filters in the spring of 2007.BC in the dust aerosol was up to 1.14%of the total mass of PM10.A remarkable seasonal variation of BC in the aerosol was observed in the order of winter>spring>autumn>summer.The peak value of BC appeared at midnight while the lowest one in the evening each day,which was just the reverse of that in the urban area.The contribution of BC to the total mass of PM10 on non-dust storm days was~11 times of that in dust storm.Through back trajectory and principal component analysis,it was found that BC in the dust aerosol over Taklimakan Desert might be attributed to the emission from the anthropogenic activities,including domestic heating,cooking,combustion of oil and natural gas,and the medium-range transport from those oases located in the margins of the desert.The total BC aerosol from the Taklimakan Desert to be transported to the eastward downstream was estimated to be 6.3×104 ton yr-1.

  3. Solar power at the edge of the Sahara desert

    Energy Technology Data Exchange (ETDEWEB)

    Bresler, Ines

    2012-07-01

    In Morocco, the turn in the energy sector is overseen by His Majesty the King himself: in 2009, the King introduced the Moroccan Solar Plan and created the Moroccan Agency for Solar Energy (MASEN) for its implementation. This year, the construction work for the first project complex will commence at the edge of the Sahara desert. (orig.)

  4. Academic Performance, School Desertion and Emotional Paradigm in University Students

    Science.gov (United States)

    Sosa, Emma Rosa Cruz; Barrientos, Laura Gática; Castro, Patricia Eugenia García; García, Jesús Hernández

    2010-01-01

    The present work aims to describe academic performance, school desertion and the emotional paradigm of the university students of the accounting school of the Benemérita Universidad Autónoma de Puebla (FCPBUAP). We have found that low academic performance is related to students' economic deficiency, which affects their concentration on their…

  5. Potential of energy farming in the southeastern California desert

    Energy Technology Data Exchange (ETDEWEB)

    Lew, V.

    1980-04-01

    The California Energy Commission is currently analyzing the use of energy farms to provide future sources of energy for California. Energy farms can be defined as growing plants and converting them to various forms of energy. The use of marginal desert lands in southeastern California for the siting of energy farms using acacia, Eucalyptus, euphorbia, quayule, jojoba, mesquite, or tamarisk is considered. Two hypothetical scenarios using either rainfall, or rainfall and groundwater as water sources were described to determine the maximum amount of energy produced from estimated amounts of suitable land in this area. Considering both scenarios, the maximum range of energy produced is .03 to 0.4 Quads. It is recommended that (1) genetic research be continued to increase biomass yields of these and other candidate plants grown in the desert; and (2) small test plots be established at varying desert locations to collect yield growth, and survival data. Once this information is known, the identification of the best plant(s) to use for energy farming in the California desert area will be known, as well as the cost and quantity of energy produced.

  6. Erosion resistance of bionic functional surfaces inspired from desert scorpions.

    Science.gov (United States)

    Zhiwu, Han; Junqiu, Zhang; Chao, Ge; Li, Wen; Ren, Luquan

    2012-02-01

    In this paper, a bionic method is presented to improve the erosion resistance of machine components. Desert scorpion (Androctonus australis) is a typical animal living in sandy deserts, and may face erosive action of blowing sand at a high speed. Based on the idea of bionics and biologic experimental techniques, the mechanisms of the sand erosion resistance of desert scorpion were investigated. Results showed that the desert scorpions used special microtextures such as bumps and grooves to construct the functional surfaces to achieve the erosion resistance. In order to understand the erosion resistance mechanisms of such functional surfaces, the combination of computational and experimental research were carried out in this paper. The Computational Fluid Dynamics (CFD) method was applied to predict the erosion performance of the bionic functional surfaces. The result demonstrated that the microtextured surfaces exhibited better erosion resistance than the smooth surfaces. The further erosion tests indicated that the groove surfaces exhibited better erosion performance at 30° injection angle. In order to determine the effect of the groove dimensions on the erosion resistance, regression analysis of orthogonal multinomials was also performed under a certain erosion condition, and the regression equation between the erosion rate and groove distance, width, and height was established.

  7. Enhancing and restoring habitat for the desert tortoise (Gopherus agassizii)

    Science.gov (United States)

    Abella, Scott R.; Berry, Kristin H.

    2016-01-01

    Habitat has changed unfavorably during the past 150 years for the desert tortoise (Gopherus agassizii), a threatened species with declining populations in the Mojave and western Sonoran Desert. To support recovery efforts, we synthesized published information on relationships of desert tortoises with three habitat features (cover sites, forage, and soil) and candidate management practices for improving these features for tortoises. In addition to their role in soil health and facilitating recruitment of annual forage plants, shrubs are used by desert tortoises for cover and as sites for burrows. Outplanting greenhouse-grown seedlings, protected from herbivory, has successfully restored (>50% survival) a variety of shrubs on disturbed desert soils. Additionally, salvaging and re-applying topsoil using effective techniques is among the more ecologically beneficial ways to initiate plant recovery after severe disturbance. Some plant species provide better-quality forage than others. Tortoises selectively forage on particular annual and herbaceous perennial species, such as legumes, with favored plants varying with phenological stage within years. Non-native grasses are non-preferred forage and contribute fuel to spreading wildfires, which damage or kill shrubs that tortoises use for cover. Maintaining a diverse "menu" of native annual forbs and decreasing non-native grasses are priorities for restoring most desert tortoise habitats. Reducing herbivory by non-native animals, carefully timing herbicide applications, and strategically augmenting annual forage plants via seeding show promise for improving tortoise forage quality. Roads, another disturbance, negatively affect habitat in numerous ways (e.g., compacting soil, altering hydrology). Techniques such as re-contouring road berms to reestablish drainage patterns, vertical mulching ("planting" dead plant material), and creating barriers to prevent trespasses can assist natural recovery on decommissioned backcountry

  8. Diversity and Ecology of Viruses in Hyperarid Desert Soils

    Science.gov (United States)

    Zablocki, Olivier; Adriaenssens, Evelien M.

    2015-01-01

    In recent years, remarkable progress has been made in the field of virus environmental ecology. In marine ecosystems, for example, viruses are now thought to play pivotal roles in the biogeochemical cycling of nutrients and to be mediators of microbial evolution through horizontal gene transfer. The diversity and ecology of viruses in soils are poorly understood, but evidence supports the view that the diversity and ecology of viruses in soils differ substantially from those in aquatic systems. Desert biomes cover ∼33% of global land masses, and yet the diversity and roles of viruses in these dominant ecosystems remain poorly understood. There is evidence that hot hyperarid desert soils are characterized by high levels of bacterial lysogens and low extracellular virus counts. In contrast, cold desert soils contain high extracellular virus titers. We suggest that the prevalence of microbial biofilms in hyperarid soils, combined with extreme thermal regimens, exerts strong selection pressures on both temperate and virulent viruses. Many desert soil virus sequences show low values of identity to virus genomes in public databases, suggesting the existence of distinct and as-yet-uncharacterized soil phylogenetic lineages (e.g., cyanophages). We strongly advocate for amplification-free metavirome analyses while encouraging the classical isolation of phages from dominant and culturable microbial isolates in order to populate sequence databases. This review provides an overview of recent advances in the study of viruses in hyperarid soils and of the factors that contribute to viral abundance and diversity in hot and cold deserts and offers technical recommendations for future studies. PMID:26590289

  9. Biological soil crusts as an integral component of desert environments

    Science.gov (United States)

    Belnap, Jayne; Weber, Bettina

    2013-01-01

    The biology and ecology of biological soil crusts, a soil surface community of mosses, lichens, cyanobacteria, green algae, fungi, and bacteria, have only recently been a topic of research. Most efforts began in the western U.S. (Cameron, Harper, Rushforth, and St. Clair), Australia (Rogers), and Israel (Friedmann, Evenari, and Lange) in the late 1960s and 1970s (e.g., Friedmann et al. 1967; Evenari 1985reviewed in Harper and Marble 1988). However, these groups worked independently of each other and, in fact, were often not aware of each other’s work. In addition, biological soil crust communities were seen as more a novelty than a critical component of dryland ecosystems. Since then, researchers have investigated many different aspects of these communities and have shown that although small to microscopic, biological soil crusts are critical in many ecological processes of deserts. They often cover most of desert soil surfaces and substantially mediate inputs and outputs from desert soils (Belnap et al. 2003). They can be a large source of biodiversity for deserts, as they can contain more species than the surrounding vascular plant community (Rosentreter 1986). These communities are important in reducing soil erosion and increasing soil fertility through the capture of dust and the fixation of atmospheric nitrogen and carbon into forms available to other life forms (Elbert et al. 2012). Because of their many effects on soil characteristics, such as external and internal morphological characteristics, aggregate stability, soil moisture, and permeability, they also affect seed germination and establishment and local hydrological cycles. Covering up to 70% of the surface area in many arid and semi-arid regions around the world (Belnap and Lange 2003), biological soil crusts are a key component within desert environments.

  10. Dental Health Care Models of Southwest Cultures. Final Report.

    Science.gov (United States)

    Pettibone, Timothy J.; Solis, Enrique, Jr.

    The major goal of this research was the development and validation of cultural models of dental health practices. The specific objectives were to determine if 3 cultural groups (American Indians, Mexican Americans, and Anglo Americans) differ in the dental health hygiene indices, characteristics, psychological factors, or social factors; to…

  11. Effects of subsidized predators, resource variability, and human population density on desert tortoise populations in the Mojave Desert, USA

    Science.gov (United States)

    Esque, Todd C.; Nussear, Kenneth E.; Drake, K. Kristina; Walde, Andrew D.; Berry, Kristin H.; Averill-Murray, Roy C.; Woodman, A. Peter; Boarman, William I.; Medica, Phil A.; Mack, Jeremy S.; Heaton, Jill S.

    2010-01-01

    Understanding predator–prey relationships can be pivotal in the conservation of species. For 2 decades, desert tortoise Gopherus agassizii populations have declined, yet quantitative evidence regarding the causes of declines is scarce. In 2005, Ft. Irwin National Training Center, California, USA, implemented a translocation project including 2 yr of baseline monitoring of desert tortoises. Unusually high predation on tortoises was observed after translocation occurred. We conducted a retrospective analysis of predation and found that translocation did not affect the probability of predation: translocated, resident, and control tortoises all had similar levels of predation. However, predation rates were higher near human population concentrations, at lower elevation sites, and for smaller tortoises and females. Furthermore, high mortality rates were not limited to the National Training Center. In 2008, elevated mortality (as high as 43%) occurred throughout the listed range of the desert tortoise. Although no temporal prey base data are available for analysis from any of the study sites, we hypothesize that low population levels of typical coyote Canis latrans prey (i.e. jackrabbits Lepus californicus and other small animals) due to drought conditions influenced high predation rates in previous years. Predation may have been exacerbated in areas with high levels of subsidized predators. Many historical reports of increased predation, and our observation of a range-wide pattern, may indicate that high predation rates are more common than generally considered and may impact recovery of the desert tortoise throughout its range.

  12. Geography as destiny? Social and ecological resilience in rangelands of the American southwest

    Science.gov (United States)

    Background/Question/Methods: Social-ecological systems perspectives focus on the reciprocal relationships between human and natural ecosystem elements and how these interactions determine human well-being, ecological state change, and land use change. In the arid southwestern US, which is dominated...

  13. Dominant processes controlling water chemistry of the Pecos River in American southwest

    Science.gov (United States)

    Yuan, Fasong; Miyamoto, Seiichi

    2005-09-01

    Here we show an analysis of river flow and water chemistry data from eleven gauging stations along the Pecos River in eastern New Mexico and western Texas, with time spanning 1959-2002. Analysis of spatial relationship between the long-term average flow and total dissolved solids (TDS) concentration allows us to illuminate four major processes controlling river chemistry, namely saline water addition, evaporative concentration with salt gain or loss, dilution with salt gain or loss, and salt storage. Of the 10 river reaches studied, six reaches exhibit the process dominated by evaporative concentration or freshwater dilution with little change in salt load. Four reaches show considerable salt gains or losses that are induced by surface-ground water interactions. This analysis suggests that the evaporative concentration and freshwater dilution are the prevailing mechanisms, but local processes (e.g., variations in hydrologic flowpath and lithologic formation) also play an important role in regulating the hydrochemistry of the Pecos River.

  14. Complex landscapes in the American Southwest: Under what conditions does desetification lead to novel ecosystems?

    Science.gov (United States)

    Novel ecosystems are often defined as no-analog communities consisting of new combinations of species that assemble under new abiotic conditions. In the Anthropocene, novel systems differ from the historical state as a result of human influences where self-organizational processes prevail to make th...

  15. Moisture transport pathways into the American Southwest from multiple oceanic sources as deduced from hydrogen isotopes.

    Science.gov (United States)

    Strong, M.; Sharp, Z. D.; Gutzler, D. S.

    2006-12-01

    There has been a long-standing controversy regarding the oceanic sources of atmospheric moisture over the southwestern US, especially during the summer monsoon circulation. Past arguments have been made for moisture sources in the Gulf of Mexico, Gulf of California, Eastern Pacific, or some combination thereof. To help resolve this problem, we are using hydrogen isotopes as a tracer to reconstruct the history of moisture being advected into central New Mexico. The hydrogen isotope composition (δD) of water vapor is dependent on many factors, including the temperature of the source ocean, rainout history, contributions from evapotranspiration over the continent, and mixing between air masses. Since April 1, 2005 we have been measuring δD of atmospheric water vapor (δDwv) at ground level 1 to 3 times per day. In addition, we periodically collect water vapor in ~300m vertical increments to ~3km above the surface using a light aircraft. We see significant temporal variations in δDwv on several different scales in the ground-level δDwv measurements. Lower δDwv values in the winter are consistent with moisture transport from the Pacific Ocean, while larger δDwv values in the summer imply moisture from a warmer body of water. During the fall, winter, and spring, large variations in δDwv (up to 80‰) can occur over the period of a few days to a few hours whereas during the summer monsoon season the δDwv values are much less variable. The relationship between δDwv and dew point also varies throughout the year; good correlations exist through portions of spring, fall, and winter, while at other times no correlation is apparent. During the summer monsoon season, a distinctive anticorrelation exists between dew point and δDwv. Using trajectory analyses, we have been able to demonstrate that many of the variations in δDwv can be explained by changes in moisture transport pathways. It appears that the source of the moisture being advected into central New Mexico can switch from the Gulf of Mexico to the Gulf of California in as little as 12 hours. Variations of δDwv are also observed within vertical profiles, where multiple layers of water vapor with distinctive δDwv values are usually noted. Trajectory analyses terminated at different altitudes allow us to correlate these variations of δDwv with different source regions. It appears that within a single column of air, water vapor from multiple source regions may be present. We also conclude that water vapor contributions from evapotranspiration in this semi-arid area are too small to significantly affect δDwv values.

  16. Vulnerability and adaptation to severe weather events in the American southwest

    Directory of Open Access Journals (Sweden)

    Riccardo Boero

    2015-06-01

    In conclusion, our findings suggest that determinants of economic growth support lower vulnerability to the weather and increase options for financing adaptation and recovery policies, but also that only some communities are likely to benefit from those processes.

  17. The Pinto shear zone; a Laramide synconvergent extensional shear zone in the Mojave Desert region of the southwestern United States

    Science.gov (United States)

    Wells, Michael L.; Beyene, Mengesha A.; Spell, Terry L.; Kula, Joseph L.; Miller, David M.; Zanetti, Kathleen A.

    2005-09-01

    The Pinto shear zone is one of several Late Cretaceous shear zones within the eastern fringe of the Mesozoic magmatic arc of the southwest Cordilleran orogen that developed synchronous with continued plate convergence and backarc shortening. We demonstrate an extensional origin for the shear zone by describing the shear-zone geometry and kinematics, hanging wall deformation style, progressive changes in deformation temperature, and differences in hanging wall and footwall thermal histories. Deformation is constrained between ˜74 and 68 Ma by 40Ar/ 39Ar thermochronology of the exhumed footwall, including multi-diffusion domain modeling of K-feldspar. We discount the interpretations, applied in other areas of the Mojave Desert region, that widespread Late Cretaceous cooling results from refrigeration due to subduction of a shallowly dipping Laramide slab or to erosional denudation, and suggest alternatively that post-intrusion cooling and exhumation by extensional structures are recorded. Widespread crustal melting and magmatism followed by extension and cooling in the Late Cretaceous are most consistent with production of a low-viscosity lower crust during anatexis and/or delamination of mantle lithosphere at the onset of Laramide shallow subduction.

  18. Gallic acid and tannase accumulation during fungal solid state culture of a tannin-rich desert plant (Larrea tridentata Cov.).

    Science.gov (United States)

    Treviño-Cueto, B; Luis, M; Contreras-Esquivel, J C; Rodríguez, R; Aguilera, A; Aguilar, C N

    2007-02-01

    Larrea tridentata (Sesse & Mocino ex DC.) Coville, also known as Larrea, gobernadora, chaparral, or creosote bush, is a shrubby plant which dominates some areas of the desert southwest in the United States and Northern Mexico and its use has not been exploited and standardized. In this study, gobernadora was studied to evaluate its potential use for support of solid state culture. Influence of two minimal media added with gobernadora powder as the sole carbon source and inducer of tannin-degrading enzymes was evaluated. Cultures were initially 70% moisture, had a pH of 5.5 and were inoculated with Aspergillus niger Aa-20 at 2 x 10(7) spores per gram of media. Analysis of pH, moisture, tannin uptake, gallic acid accumulation and tannase production were evaluated. Results indicated a high content of condensed (39.4%dm) and hydrolysable (22.8%dm) tannins. Invasion capacity of fungal growth was of 0.15 mmh(-1). Tannase production reached values of 1040 Ul(-1) at 43 h of culture. During the first 48 h of culture, the concentration of gallic acid accumulation was 0.33 gl(-1). Gobernadora is a potential source of gallic acid and tannase production by solid state culture; however, further optimization of the process is needed.

  19. Climate change and climate systems influence and control the atmospheric dispersion of desert dust: implications for human health

    Science.gov (United States)

    Griffin, Dale W.; Ragaini, Richard C.

    2010-01-01

    The global dispersion of desert dust through Earth’s atmosphere is greatly influenced by temperature. Temporal analyses of ice core data have demonstrated that enhanced dust dispersion occurs during glacial events. This is due to an increase in ice cover, which results in an increase in drier terrestrial cover. A shorter temporal analysis of dust dispersion data over the last 40 years has demonstrated an increase in dust transport. Climate systems or events such as the North Atlantic Oscillation, the Indian Ocean subtropical High, Pacific Decadal Oscillation, and El Nino-Sothern Oscillation are known to influence global short-term dust dispersion occurrence and transport routes. Anthropogenic influences on dust transport include deforestation, harmful use of topsoil for agriculture as observed during the American Dust Bowl period, and the creation of dry seas (Aral Sea) and lakes (Lake Owens in California and Lake Chad in North Africa) through the diversion of source waters (for irrigation and drinking water supplies). Constituents of desert dust both from source regions (pathogenic microorganisms, organic and inorganic toxins) and those scavenged through atmospheric transport (i.e., industrial and agricultural emissions) are known to directly impact human and ecosystem health. This presentation will present a review of global scale dust storms and how these events can be both a detriment and benefit to various organisms in downwind environments.

  20. Aftershocks of the 2010 Mw 7.2 El Mayor-Cucapah earthquake revealcomplex faulting in the Yuha Desert, California

    Science.gov (United States)

    Kroll, K.; Cochran, Elizabeth S.; Richards-Dinger, K.; Sumy, Danielle

    2013-01-01

    We detect and precisely locate over 9500 aftershocks that occurred in the Yuha Desert region during a 2 month period following the 4 April 2010 Mw 7.2 El Mayor-Cucapah (EMC) earthquake. Events are relocated using a series of absolute and relative relocation procedures that include Hypoinverse, Velest, and hypoDD. Location errors are reduced to ~40 m horizontally and ~120 m vertically.Aftershock locations reveal a complex pattern of faulting with en echelon fault segments trending toward the northwest, approximately parallel to the North American-Pacific plate boundary and en echelon, conjugate features trending to the northeast. The relocated seismicity is highly correlated with published surface mapping of faults that experienced triggered surface slip in response to the EMC main shock. Aftershocks occurred between 2 km and 11 km depths, consistent with previous studies of seismogenic thickness in the region. Three-dimensional analysis reveals individual and intersecting fault planes that are limited in their along-strike length. These fault planes remain distinct structures at depth, indicative of conjugate faulting, and do not appear to coalesce onto a throughgoing fault segment. We observe a complex spatiotemporal migration of aftershocks, with seismicity that jumps between individual fault segments that are active for only a few days to weeks. Aftershock rates are roughly consistent with the expected earthquake production rates of Dieterich (1994). The conjugate pattern of faulting and nonuniform aftershock migration patterns suggest that strain in the Yuha Desert is being accommodated in a complex manner.

  1. Assessing the impact of fire on the spatial distribution of Larrea tridentata in the Sonoran Desert, USA.

    Science.gov (United States)

    Fuentes-Ramirez, Andres; Mudrak, Erika L; Caragea, Petrutza C; Holzapfel, Claus; Moloney, Kirk A

    2015-06-01

    In southwestern American deserts, fire has been historically uncommon because of insufficient continuity of fuel for spreading. However, deserts have been invaded by exotic species that now connect the empty space between shrubs to carry fire. We hypothesized that fire would change the spatial distribution of surviving Larrea tridentata shrubs. We established two study plots, one each in a burned and unburned area, and recorded location and living status of all shrubs. We performed univariate and bivariate point pattern analyses to characterize the impact of fire on the overall distribution of shrubs. Additionally, we used a simple wildfire model to determine how close we could come to reconstructing the observed spatial pattern of living and dead shrubs. We found a hyper-dispersed pattern of shrubs at finer scales and a random pattern at broader scales for both the unburned plot and for the living and dead shrubs combined in the burned plot, the latter providing an approximation of the pre-burn distribution of shrubs. After fire, living shrubs showed a clustered pattern at scales >2.5 m, whereas dead shrubs were randomly distributed, indicating that fire caused a change in the spatial pattern of the surviving shrubs. The fire model was able to partially reconstruct the spatial pattern of Larrea, but created a more clustered distribution for both living and dead shrubs. Our study reinforces the key role of fire in altering landscapes that had not been habituated to fire, and suggests the existence of potential cascading effects across the entire plant community.

  2. Native Americans with Diabetes

    Science.gov (United States)

    ... Read the MMWR Science Clips Native Americans with Diabetes Better diabetes care can decrease kidney failure Language: ... between 1996 and 2013. Problem Kidney failure from diabetes was highest among Native Americans. Native Americans are ...

  3. Obesity and African Americans

    Science.gov (United States)

    ... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  4. Inversion of the asymmetry factor for desert areas of China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Deserts,which have high surface albedo and wide area,are important components of the earth system.It is very important for the research of surface radiation and energy balance to understand the anisotropic scattering of desert areas.The emergence and development of multi-angle remote sensing made possible the inversion of the anisotropic scattering of desert areas at the regional or global scale.Firstly,this paper explored the accuracy of the inversion of asymmetry factor using the Hapke model and the simulated single-and multi-phase MISR data.Based on the results,the asymmetry factor of representative surface of desert areas in northwestern China was retrieved.The values of the asymmetry factor retrieved from MISR data were compared with the values retrieved from the laboratory data.The results showed that the single-phase MISR data could be used for the inversion of asymmetry parameter of desert areas.The sign of the asymmetry parameter for the laboratory measurements was positive,which suggests that the surface of laboratory samples is forward scattering.The sign of the asymmetry parameter for MISR data was negative;that is,it is backscattering.The values of the asymmetry parameters retrieved from MISR data were related to the character of the land surface.At Loulan,where the surface was smoother than other sites,retrieved values exhibited the largest negative values of asymmetry factor,suggesting the strongest backscattering.The sand dune area of the Kumtag Desert,which has the greatest roughness,had only slightly negative asymmetry factor values.These findings indicated that at the sensor scale,a rough surface(e.g.,dunes) does not necessarily mean more backscattering than a smooth surface.This finding has significant implications for empirical methods(e.g.,using the normalized index of backward-scattered radiance minus forward-scattered radiance as an indicator of surface roughness),which should be used carefully for analyzing surface roughness from the remote

  5. Dynamics and Resilience of Desert Ecosystems under Changing Climate

    Science.gov (United States)

    Stewart, J.; Wainwright, J.; Parsons, A. J.; Okin, G. S.; Bestelmeyer, B.; Fredrickson, E. L.; Schlesinger, W. H.

    2008-12-01

    Ecological models have been used to probe the causes of spatial complexity and predict specific responses of desert ecosystems. However, many models have been limited in their focus: models of dynamics have been developed with no consideration of the inherent patchiness or patterns in the vegetation, or else models have been developed to generate patterns with no consideration of the dynamics. Models that attempt to address both pattern and dynamics have been qualitative and descriptive. Furthermore, if, as is commonly believed, both dynamics and patterns/patchiness are a function of resource (specifically water) limitation, then there has been little integration of this relationship into such models. Consequently, these models have limited utility for understanding resilience of desert ecosystems. Here we present an integrated approach to the observed patchiness and dynamics in desert vegetation that is based on a sound process-based understanding and is formulated to accommodate previous conceptual models within an overarching framework. This framework is implemented as a mathematical model. Our contribution represents an advance over previous work in that we propose a general model framework for the analysis of ecosystem change in deserts that explicitly considers spatial interactions among multiple vegetation types and multiple resources, and predict specific responses to a variety of endogenous and exogenous disturbances. We present an application of this model to investigate conditions the conditions that would result in observed desert vegetation patterns in south-western desert systems of North America. In particular, we investigate the encroachment of shrubs (Larrea tridentata) into formerly pure stands of grass (Bouteloua eriopoda). We present the results of simulations that rest on rainfall data that was reconstructed for the Jornada Basin Long-Term Ecological Research site in southern New Mexico, USA based on 300-year tree- ring records. The results

  6. Eastern desert ware : traces of the inhabitants of the eastern desert in Egypt and Sudan during the 4th-6th centuries CE

    NARCIS (Netherlands)

    Barnard, Hans

    2008-01-01

    Several sites in the desert between the Nile and the Red Sea, in Egypt and Sudan, as well as in the Nubian Nile Valley have produced the sherds of decorated hand-made cups and bowls, now identified as Eastern Desert Ware (EDW). Because of their small number and enigmatic origin these sherds have bee

  7. Echinococcus granulosus Prevalence in Dogs in Southwest Nigeria

    Directory of Open Access Journals (Sweden)

    Oyeduntan Adejoju Adediran

    2014-01-01

    Full Text Available Echinococcosis is a public health parasitic disease that is cosmopolitan (Echinococcus granulosus in its distribution. Domestic dogs (Canis familiaris have been recognised as the definitive host of the parasite. The present study was carried out to determine the prevalence of canine echinococcosis in Southwest Nigeria using direct enzyme linked immunosorbent assay (ELISA to detect sera antigen. Two hundred and seventy-three (273 canine sera were tested for the presence of Echinococcus antigen. Purpose of keeping (hunting or companion, age (young or adult, and sex of each dog were considered during sampling. Total prevalence recorded was 12.45% (34/273. There was significant difference (P0.05 between young and adult dogs. There was no association between sex and prevalence of canine echinococcosis. The result of this study established the presence of canine echinococcosis in Southwest Nigeria; thus there is the possibility of occurrence of zoonotic form of the disease (human cystic hydatid diseases in the region.

  8. Marine mammal strandings in the New Caledonia region, Southwest Pacific

    OpenAIRE

    Borsa, Philippe

    2006-01-01

    International audience; Four hundred twenty three marine mammals, in 72 stranding events, were recorded between 1877 and 2005 in New Caledonia, the Loyalty Islands, and Vanuatu in the southwest Pacific. Sixteen species were represented in this count, including: minke whale, Balaenoptera acutorostrata (1 single stranding), sei whale, B. borealis (1 single stranding), blue whale, B. musculus (1 single stranding), humpback whale, Megaptera novaeangliae (2 single strandings), giant sperm whale, P...

  9. Butterflies and Dragon-Eagles: Processing Epics from Southwest China

    Directory of Open Access Journals (Sweden)

    Mark Bender

    2012-03-01

    Full Text Available In the mountains of southwest China, epic narratives are part of the traditional performance-scapes of many ethnic minority cultures. In some cases locals participate in the preservation of oral or oral-connected epics from their respective areas. This article discusses the dynamics of acquiring and translating texts from two major ethnic minority groups in cooperation with local tradition-bearers, poets, and scholars.

  10. Schistidium sordidum new to Turkey and southwest Asia

    Directory of Open Access Journals (Sweden)

    Batan Nevzat

    2013-01-01

    Full Text Available Schistidium sordidum I. Hagen (Grimmiaceae is recorded for the first time in Southwest Asia (Turkey. The specimen was collected in the south (Ağrı Mountain of Iğdır province, East Anatolia Region of Turkey. The nearest locality to Turkey for this species is Russia. A site description, illustrations, ecology, distribution and diagnostic characters of the species are presented.

  11. Geothermal development in southwest Idaho: the socioeconomic data base

    Energy Technology Data Exchange (ETDEWEB)

    Spencer,S.G.; Russell, B.F. (eds.)

    1979-09-01

    This report inventories, analyzes, and appraises the existing socioeconomic data base for the ten counties in southwest Idaho that would be impacted by any significant geothermal development. The inventory describes key sociological demographic, and economic characteristics, and presents spatial boundaries, housing data, and projections of population and economic activity for the counties. The inventory identifies the significant gaps in the existing data base and makes recommendations for future research.

  12. Geothermal development in southwest Idaho: the socioeconomic data base

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, S.G.; Russell, B.F.

    1979-09-01

    This report inventories, analyzes, and appraises the exiting socioeconomic data base for the ten counties in southwest Idaho that would be impacted by any significant geothermal development. The inventory describes key sociological demographic, and economic characteristics, and presents spatial boundaries, housing data, and projections of population and economic activity for the counties. The inventory identifies the significant gaps in the existing data base and makes recommendations for future research.

  13. ANTS AS INDICATORS OF EXPOSURE TO ENVIRONMENTAL STRESSORS IN NORTH AMERICAN DESERT GRASSLANDS

    Science.gov (United States)

    The relative abundance of ant species was measured by pit-fall trapping at 44 sites in southern New Mexico and southeastern Arizona, U.S.A..Sites were selected for study based on documentation of a history of disturbance or protection from disturbance, exposure to varying intens...

  14. Desert Storm and the New American Way of War: Implications for Air Force 2030

    Science.gov (United States)

    2012-06-01

    8 Alexander Wendt , Social Theory of International Politics (Cambridge: Cambridge University Press, 1999), 374...Alexander. Social Theory of International Politics. Cambridge: Cambridge University Press, 1999. Williams, Mel. Superfighters: The Next Generation...Internal Air Force choices, combined with external fiscal and social constraints, suggest a continuance of the current trend. The question is whether

  15. Wither the Fruited Plain: The Long Expedition and the Description of the "Great American Desert"

    Science.gov (United States)

    Sweeney, Kevin Z.

    2005-01-01

    The view from Pikes Peak is breathtaking. In the summer of 1893, Katherine Lee Bates sat on the summit of Pikes Peak, inspired by the panorama to pen the words to "America the Beautiful." Her poem was set to the tune "Materna" by Samuel Augustus Ward two years later to become one of our nation's most beloved anthems. Many…

  16. Evaluation on Comprehensive Benefit of Natural Forest Protection Project in Southwest China

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    According to the problem of seriously degraded natural forest in Southwest China prior to the implementation of Natural Forest Protection Project, under the guidance of principle of practicality and systematicness, we establish the comprehensive-benefit evaluation index system of restoring the degraded natural forest in Southwest China, including 3 second-level indices, 12 third-level indices and 24 fourth-level indices. In addition, we use the method of Analytic Hierarchy Process to conduct comprehensive-benefit evaluation on implementation of Natural Forest Protection Project in Southwest China. The results show that since ten years of implementation of Natural Forest Protection Project in Southwest China, it has gained considerable comprehensive benefit. The comprehensive evaluation index of Natural Forest Protection Project in Southwest China is 83.08; the ecological benefit index of Natural Forest Protection Project in Southwest China is 56.75; the economic benefit index of Natural Forest Protection Project in Southwest China is 19.05; the social benefit index of Natural Forest Protection Project in Southwest China is 7.28. The effect of construction of Natural Forest Protection Project in Southwest China is good. The evaluation index system and research results in this paper will provide the empirical guidance for comprehensive-benefit evaluation of Natural Forest Protection Project in China, and especially in Southwest China.

  17. Reference intervals and physiologic alterations in hematologic and biochemical values of free-ranging desert tortoises in the Mojave Desert

    Science.gov (United States)

    Christopher, Mary M.; Berry, Kristin H.; Wallis, I.R.; Nagy, K.A.; Henen, B.T.; Peterson, C.C.

    1999-01-01

    Desert tortoise (Gopherus agassizii) populations have experienced precipitous declines resulting from the cumulative impact of habitat loss, and human and disease-related mortality. Evaluation of hematologic and biochemical responses of desert tortoises to physiologic and environmental factors can facilitate the assessment of stress and disease in tortoises and contribute to management decisions and population recovery. The goal of this study was to obtain and analyze clinical laboratory data from free-ranging desert tortoises at three sites in the Mojave Desert (California, USA) between October 1990 and October 1995, to establish reference intervals, and to develop guidelines for the interpretation of laboratory data under a variety of environmental and physiologic conditions. Body weight, carapace length, and venous blood samples for a complete blood count and clinical chemistry profile were obtained from 98 clinically healthy adult desert tortoises of both sexes at the Desert Tortoise Research Natural area (western Mojave), Goffs (eastern Mojave) and Ivanpah Valley (northeastern Mojave). Samples were obtained four times per year, in winter (February/March), spring (May/June), summer (July/August), and fall (October). Years of near-, above- and below-average rainfall were represented in the 5 yr period. Minimum, maximum and median values, and central 95 percentiles were used as reference intervals and measures of central tendency for tortoises at each site and/or season. Data were analyzed using repeated measures analysis of variance for significant (P < 0.01) variation on the basis of sex, site, season, and interactions between these variables. Significant sex differences were observed for packed cell volume, hemoglobin concentration, aspartate transaminase activity, and cholesterol, triglyceride, calcium, and phosphorus concentrations. Marked seasonal variation was observed in most parameters in conjunction with reproductive cycle, hibernation, or seasonal

  18. Relative abundance of desert tortoises on the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Rautenstrauch, K.R.; O`Farrell, T.P.

    1993-12-31

    Seven hundred fifty-nine transects having a total length of 1,191 km were walked during 1981--1986 to determine the distribution and relative abundance of desert tortoises (Gopherus agassizii) on the Nevada Test Site (NTS). The abundance of tortoises on NTS was low to very low relative to other populations in the Mojave Desert. Sign of tortoises was found from 880 to 1,570 m elevation and was more abundant above 1,200 m than has been reported previously for Nevada. Tortoises were more abundant on NTS on the upper alluvial fans and slopes of mountains than in valley bottoms. They also were more common on or near limestone and dolomite mountains than on mountains of volcanic origin.

  19. Biotechnological Applications Derived from Microorganisms of the Atacama Desert

    Directory of Open Access Journals (Sweden)

    Armando Azua-Bustos

    2014-01-01

    Full Text Available The Atacama Desert in Chile is well known for being the driest and oldest desert on Earth. For these same reasons, it is also considered a good analog model of the planet Mars. Only a few decades ago, it was thought that this was a sterile place, but in the past years fascinating adaptations have been reported in the members of the three domains of life: low water availability, high UV radiation, high salinity, and other environmental stresses. However, the biotechnological applications derived from the basic understanding and characterization of these species, with the notable exception of copper bioleaching, are still in its infancy, thus offering an immense potential for future development.

  20. Aircraft and satellite remote sensing of desert soils and landscapes

    Science.gov (United States)

    Petersen, G. W.; Connors, K. F.; Miller, D. A.; Day, R. L.; Gardner, T. W.

    1987-01-01

    Remote sensing data on desert soils and landscapes, obtained by the Landsat TM, Heat Capacity Mapping Mission (HCMM), Simulated SPOT, and Thermal IR Multispectral Scanner (TIMS) aboard an aircraft, are discussed together with the analytical techniques used in the studies. The TM data for southwestern Nevada were used to discriminate among the alluvial fan deposits with different degrees of desert pavement and varnish, and different vegetation cover. Thermal-IR data acquired from the HCMM satellite were used to map the spatial distribution of diurnal surface temperatures and to estimate mean annual soil temperatures in central Utah. Simulated SPOT data for northwestern New Mexico identified geomorphic features, such as differences in eolian sand cover and fluvial incision, while the TIMS data depicted surface geologic features of the Saline Valley in California.

  1. Field Performance of Photovoltaic Systems in the Tucson Desert

    Science.gov (United States)

    Orsburn, Sean; Brooks, Adria; Cormode, Daniel; Greenberg, James; Hardesty, Garrett; Lonij, Vincent; Salhab, Anas; St. Germaine, Tyler; Torres, Gabe; Cronin, Alexander

    2011-10-01

    At the Tucson Electric Power (TEP) solar test yard, over 20 different grid-connected photovoltaic (PV) systems are being tested. The goal at the TEP solar test yard is to measure and model real-world performance of PV systems and to benchmark new technologies such as holographic concentrators. By studying voltage and current produced by the PV systems as a function of incident irradiance, and module temperature, we can compare our measurements of field-performance (in a harsh desert environment) to manufacturer specifications (determined under laboratory conditions). In order to measure high-voltage and high-current signals, we designed and built reliable, accurate sensors that can handle extreme desert temperatures. We will present several benchmarks of sensors in a controlled environment, including shunt resistors and Hall-effect current sensors, to determine temperature drift and accuracy. Finally we will present preliminary field measurements of PV performance for several different PV technologies.

  2. DESERT ECOSYSTEMS: MAPPING, MONITORING & ASSESSMENT USING SATELLITE REMOTE SENSING

    Directory of Open Access Journals (Sweden)

    A. S. Arya

    2012-09-01

    Full Text Available Desert ecosystems are unique but fragile ecosystems , mostly vulnerable to a variety of degradational processes like water erosion, vegetal degradation, salinity, wind erosion , water logging etc. Some researchers consider desertification to be a process of change, while others view it as the end result of a process of change. There is an urgent need to arrest the process of desertification and combat land degradation. Under the auspices of the United Nations Convention to Combat Desertification (UNCCD, Space Applications Centre, Ahmedabad has undertaken the task of mapping, monitoring and assessment of desertification carrying out pilot project in hot and cold desert regions in drylands on 1:50,000 scale followed by systematic Desertification Status Mappaing (DSM of India on 1:500,000 scale.

  3. Ancient photosynthetic eukaryote biofilms in an Atacama Desert coastal cave

    Science.gov (United States)

    Azua-Bustos, A.; Gonzalez-Silva, C.; Mancilla, R.A.; Salas, L.; Palma, R.E.; Wynne, J.J.; McKay, C.P.; Vicuna, R.

    2009-01-01

    Caves offer a stable and protected environment from harsh and changing outside prevailing conditions. Hence, they represent an interesting habitat for studying life in extreme environments. Here, we report the presence of a member of the ancient eukaryote red algae Cyanidium group in a coastal cave of the hyperarid Atacama Desert. This microorganism was found to form a seemingly monospecific biofilm growing under extremely low photon flux levels. Our work suggests that this species, Cyanidium sp. Atacama, is a new member of a recently proposed novel monophyletic lineage of mesophilic "cave" Cyanidium sp., distinct from the remaining three other lineages which are all thermo-acidophilic. The cave described in this work may represent an evolutionary island for life in the midst of the Atacama Desert. ?? Springer Science + Business Media, LLC 2009.

  4. The solar zenith angle dependence of desert albedo

    Science.gov (United States)

    Wang, Zhuo; Barlage, Michael; Zeng, Xubin; Dickinson, Robert E.; Schaaf, Crystal B.

    2005-03-01

    Most land models assume that the bare soil albedo is a function of soil color and moisture but independent of solar zenith angle (SZA). However, analyses of the Moderate Resolution Imaging Spectroradiometer (MODIS) Bidirectional Reflectance Distribution Function (BRDF) and albedo data over thirty desert locations indicate that bare soil albedo does vary with SZA. This is further confirmed using the in situ data. In particular, bare soil albedo normalized by its value at 60° SZA can be adequately represented by a one-parameter formulation (1 + C)/(1 + 2C * cos(SZA)) or a two-parameter formulation (1 + B1 * f1(SZA) + B2 * f2(SZA)). Using the MODIS and in situ data, the empirical parameters C, B1, and B2 are taken as 0.15, 0.346 and 0.063. The SZA dependence of soil albedo is also found to significantly affect the modeling of land surface energy balance over a desert site.

  5. Satellite-Derived Extinction at A Desert Site

    Science.gov (United States)

    Walker, P. L.; Blomshield, F. S.

    2002-12-01

    We have been conducting research aimed at enabling determination of desert optical environments from meteorological and satellite observations. To this end we have been making Rotating Shadowband Radiometer measurements, collecting aerosol size distributions, visibility and meteorological data continuously for the past 2 years in the Indian Wells Valley of the Mojave Desert of California. These data present an opportunity to validate satellite retrieval of atmospheric optical depth. Specifically, MISR-derived optical depths are compared to those derived from Shadowband measurements. A crude measure of extinction can be made by dividing the optical depth by the height of the mixing layer. The validity of this procedure is determined by comparison with extinction directly measured by nephelometers and calculated from measured aerosol size distributions.

  6. Ancient Leishmaniasis in a Highland Desert of Northern Chile

    OpenAIRE

    Maria Antonietta Costa; Carney Matheson; Lucia Iachetta; Agustín Llagostera; Otto Appenzeller

    2009-01-01

    BACKGROUND: Leishmaniasis is an infectious disease endemic today in many areas of South America. METHODOLOGY: We discovered morphologic and molecular evidence of ancient infections in 4 female skulls in the archaeological cemetery of Coyo Oriente, in the desert of San Pedro de Atacama, Northern Chile. The boney facial lesions visible in the skulls could have been caused by a number of chronic infections including chronic Leishmaniasis. This diagnosis was confirmed using PCR-sequenced analyses...

  7. Seed Mucilage Improves Seedling Emergence of a Sand Desert Shrub

    OpenAIRE

    Xuejun Yang; Baskin, Carol C.; Baskin, Jerry M.; Guangzheng Liu; Zhenying Huang

    2012-01-01

    The success of seedling establishment of desert plants is determined by seedling emergence response to an unpredictable precipitation regime. Sand burial is a crucial and frequent environmental stress that impacts seedling establishment on sand dunes. However, little is known about the ecological role of seed mucilage in seedling emergence in arid sandy environments. We hypothesized that seed mucilage enhances seedling emergence in a low precipitation regime and under conditions of sand buria...

  8. Stone circles on the harraat of Syrian desert

    CERN Document Server

    Sparavigna, Amelia Carolina

    2012-01-01

    Recently some stone structures covering the harraat of the Syrian desert had been investigated using satellite imagery (arXiv:1106.4665). Dispersed in an arid landscape, they were probably made during the Neolithic period. Some of these structures are here discussed, which display a possible use as ancient sun observatories. For the analysis, a freely available software is used which can be quite suitable for evaluating the effect of solar radiation on physical features of natural structures too.

  9. Topographic Signatures of Geomorphic Processes at Desert Piedmonts

    Science.gov (United States)

    Farr, T. G.

    2004-12-01

    Geomorphic processes operating on desert piedmonts leave their mark in the topography of the piedmonts, measured at a range of scales. For example, at the km to 10's of m scale, slope, curvature, and dissection give clues to the relative importance of erosional, aggradational, and transport processes. When a desert piedmont is dominated by erosional and transport processes, a pediment is formed. Conversely, when aggradational processes dominate, alluvial fans are formed. The relative rates of uplift vs. aggradation determine the slope of the fan and whether the fan is dissected. Changes in uplift rate or climatic conditions can lead to isolation of the currently forming fan surface through entrenchment and construction of another fan either further from the mountain front (decreased uplift or increased runoff) or closer to the mountain front (increased uplift or decreased runoff). Fitting 3-dimensional surfaces to alluvial fan units allows parameters for the apex position, slope, and radial curvature to be compared with unit age. The topographic signature of individual fan units will help in regional correlation of fan surfaces and may assist in separating the effects of climate and uplift. At scales of m to cm, processes such as salt weathering, aeolian deposition, and desert pavement formation dominate. The lithologies that make up the piedmont determine their susceptibility to processes of disintegration due to salts (e.g. coarse-grained rocks) or dissolution (e.g. limestones). The composition of the source areas also helps determine the relative importance of debris and mud flows. Resistant lithologies tend to form desert pavement surfaces with time, caused by infiltration of aeolian dust below a monolayer of resistant pebbles to cobbles. This leads to local relief of a few cm, while surfaces composed of easily weathered lithologies have much lower relief at that scale. Work performed under contract to NASA.

  10. Ancient Leishmaniasis in a highland desert of Northern Chile.

    Directory of Open Access Journals (Sweden)

    Maria Antonietta Costa

    Full Text Available BACKGROUND: Leishmaniasis is an infectious disease endemic today in many areas of South America. METHODOLOGY: We discovered morphologic and molecular evidence of ancient infections in 4 female skulls in the archaeological cemetery of Coyo Oriente, in the desert of San Pedro de Atacama, Northern Chile. The boney facial lesions visible in the skulls could have been caused by a number of chronic infections including chronic Leishmaniasis. This diagnosis was confirmed using PCR-sequenced analyses of bone fragments from the skulls of the affected individuals.Leishmaniasis is not normally found in the high-altitude desert of Northern Chile; where the harsh climate does not allow the parasite to complete its life cycle. The presence of Leishmaniasis in ancient skulls from the region implies infection by the protozoan in an endemic area-likely, in our subjects, to have been the lowlands of North-Eastern Argentina or in Southern Bolivia. CONCLUSIONS: We propose that the presence of the disease in ancient times in the high altitude desert of San Pedro de Atacama is the result of an exogamic system of patrilocal marriages, where women from different cultures followed their husbands to their ancestral homes, allowing immigrant women, infected early in life, to be incorporated in the Atacama desert society before they became disfigured by the disease. The present globalization of goods and services and the extraordinary facile movement of people across borders and continents have lead to a resurgence of infectious diseases and re-emergence of infections such as Leishmaniasis. We show here that such factors were already present millennia ago, shaping demographic trends and the epidemiology of infections just as they do today.

  11. The Mystery of the Gun Turret in the Desert

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, R. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-11-30

    The mystery of the gun turret in the desert began with an ingenious idea: to develop a reusable open-air line of sight diagnostic device to support LLNL’s early nuclear weapons development efforts. Obtained from the Mare Island Navy Shipyard (MINS) in January 1957, the gun turret traveled by ship to the Naval Construction Battalion base at Port Hueneme, California, and then by truck to Area 2 in the Yucca Flats valley at the Nevada Nuclear Security Site (NNSS).

  12. The evolution of deserts with climatic changes in China since 150 ka B.P.

    Institute of Scientific and Technical Information of China (English)

    董光荣; 陈惠忠; 王贵勇; 李孝泽; 邵亚军; 金炯

    1997-01-01

    According to the bioclimatic zones, dune mobility and the fabric characteristics of stratigraphic sedimentary facies, the deserts in China are divided into Eastern, Western, Central and Northwestern deserts. Based on the records of stratigraphical facies, climatic proxies, historical data, etc. in each desert region, the evolution of deserts with climatic changes in time and space since 150 ka B. P. in China are dealt with; then the evolution of deserts in relation to the glacial climatic fluctuations caused by solar radiation changes, underlying surface variation and their feedback mechanism is discussed through comparison with global records; finally, in consideration of global wanning due to increasing of greenhouse gases such as CO2, the possible tendency of the evolution of deserts and the climatic changes is discussed.

  13. [Research advance in seed germination of desert woody plants].

    Science.gov (United States)

    Chang, Wei; Wu, Jian-guo; Liu, Yan-hong

    2007-02-01

    This paper reviewed the research methods of desert woody plants seed germination, and the effects of internal and external ecological factors on it. Most researchers use incubator and artificial climate chamber to dispose the seeds, while field investigation was few involved. Seed dormancy is the important physiological factor affecting germination, while seed size, mass and color are closely correlated with its maturity and vigor. The poor permeability of seed capsule is a barrier that restrains the germination, which can be weakened or eliminated by shaving, cutting, treating with low temperature, and dipping in chemical reagent, etc. Seed water content has a close correlation with its storage life and water-absorbing capability. Suitable temperature is the prerequisite of seed germination, while changing temperature can accelerate the germination. Soil moisture content is a limiting factor, while illumination is not so essential to the seed germination of most desert woody plants. Sand-burying plays an important role in the seed germination through regulating illumination, temperature, and soil moisture content. Salinity stress restrains the seed germination of desert woody plants observably. In further studies, the effects of multi-factors and the eco-physiological and molecular biological mechanisms of germination should be more concerned.

  14. Patton's tracks in the Mojave Desert, USA: An ecological legacy

    Science.gov (United States)

    Belnap, J.; Warren, S.D.

    2002-01-01

    Recovery of soil properties from World War II-era military training exercises in the Mojave Desert was measured approximately 55 years following disturbance. Tracks from military vehicles were still visible, particularly in areas of desert pavement. Soil penetrability was much lower in visible tracks than outside the tracks. Soils in tracks had fewer rocks in the top 10 cm of the soil profile than adjacent untracked soils. Larger particles (> 4.8 mm) formed a moderately well-developed pavement outside of the tracks, while smaller, loose particles (???4.8 mm) dominated the surface of the tracks. The time required to restore the desert pavement is likely to be measured in centuries. Based on biomass estimates, the cyanobacterial component of biological soil crusts had recovered 46-65% in tracks, compared to outside the tracks. Overall recovery of lichen cover has been much slower. Under plant canopies, cover of Collema tenax was not significantly different between areas inside and outside the tracks; however, recovery of Catapyrenium squamulosum was only 36%. In plant interspaces with less favorable moisture and temperature conditions, C. tenax showed a 6% recovery and C. squamulosum a 3% recovery. Assuming recovery of the biological soil crust is linear, and complete only when the most sensitive species (C. squamulosum) has fully recovered in the most limiting microhabitats (plant interspaces), it may require almost two millennia for full recovery of these areas.

  15. Fungi and bacteria involved in desert varnish formation

    Science.gov (United States)

    Taylor-George, S.; Palmer, F.; Staley, J. T.; Curtiss, B.; Adams, J. B.; Borns, D. J.

    1983-01-01

    Desert varnish is a coating of ferromanganese oxides and clays that develops on rock surfaces in arid to semi-arid regions. Active respiration but not photosynthesis was detected on varnished rock surfaces from the Sonoran Desert. Light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations, and cultivation experiments indicate that both fungi, primarily dematiaceous hyphomycetes, and bacteria are found on and within desert varnish coatings from the arid regions studied. Some fungi grow as microcolonial fungi (MCF) on rocks, and microscopic observations suggest MCF become incorporated in the varnish coating. SEM-EDAX (energy dispersive X-ray systems) analyses indicate the MCF contain 3 of the characteristic elements of varnish: iron, aluminum, and silicon. In some locations, MCF are also enriched in manganese relative to the rock substratum. Furthermore, some of the dematiaceous hyphomycetes that have been cultivated are able to oxidize manganese under laboratory conditions. It is possible that manganese-oxidizing bacteria, which are found in varnish, also play an important role in varnish formation.

  16. Fog deposition to a Tillandsia carpet in the Atacama Desert

    Directory of Open Access Journals (Sweden)

    P. Osses

    2009-09-01

    Full Text Available In the Atacama Desert, one of the driest places on earth, fog deposition plays an important role for the water balance and for the survival of vulnerable ecosystems. The eddy covariance method, previously applied for the quantification of fog deposition to forests in various parts of the world, was used for the first time to measure deposition of fog water to a desert. In this exploratory study we estimate the amount of water available for the ecosystem by deposition and determine the relevant processes driving fog deposition. This is especially important for the species Tillandsia landbecki living in coastal Atacama at the limit of plant existence with fog and dew being the only sources of water. Between 31 July and 19 August 2008 approximately 2.5 L m−2 of water were made available through deposition. Whole-year deposition was estimated as 25 L m−2. Turbulent upward fluxes occurred several times during the evenings and are explained by the formation of radiation fog. In connection with that, underestimates of the deposition are assumed. More detailed studies covering various seasons and all parameters and fluxes contributing to the local energy balance are suggested. This will help to further develop understanding about the processes of (i deposition of water to the desert, and (ii intensification of advection fog through additional formation of radiation fog.

  17. Desert shrub stemflow and its significance in soil moisture replenishment

    Directory of Open Access Journals (Sweden)

    X.-P. Wang

    2011-02-01

    Full Text Available Stemflow of xerophytic shrubs represents a significant component of water replenishment to the soil-root system influencing water utilization of plant roots at the stand scale, especially in water scarce desert ecosystems. In this study, stemflow of Caragana korshinskii was quantified by an aluminum foil collar collection method on re-vegetated sand dunes of the Shapotou restored desert ecosystem in northwestern China. Time domain reflectometry probes were inserted horizontally at 20 different soil profile depths under the C. korshinskii shrub to monitor soil moisture variation at hourly intervals. Results indicated that 2.2 mm precipitation was necessary for the generation of stemflow for C. korshinskii. Stemflow averaged 8% of the gross precipitation and the average funnelling ratio was as high as 90. The soil moisture in the uppermost soil profile was strongly correlated with individual rainfall and the stemflow strengthened this relationship. Therefore, it is favourable for the infiltrated water redistribution in the deeper soil profile of the root zone. Consequently, stemflow contributes significantly to a positive soil moisture balance in the root zone and the replenishment of soil moisture at deeper soil layers. This plays an important role in plant survival and the general ecology of arid desert environments.

  18. Prehistory of the Carson Desert and Stillwater Mountains: Environment, Mobility, and Subsistence in a Great Basin Wetland, by Robert L. Kelly, University of Utah Anthropological Papers Number 123, Salt Lake City, 2001

    Directory of Open Access Journals (Sweden)

    Todd Bostwick

    2001-11-01

    Full Text Available The Great Basin of Western North America is one of the. legendary deserts of the world. This rugged, wide open, and apparently harsh landscape has long served as a backdrop for human drama. Gold seekers and immigrants of the 19th century immortalized the rigors of travelling across the Great Basin on their way to greener grass in California and Oregon. But archaeological research has shown that human occupation of the Great Basin dates back for thousands of years, and ethnographic accounts of Native Americans who lived in this desert have played an important role in the development of concepts of hunter-gatherer subsistence and settlement patterns. It is the Indians of the Great Basin that Julian Steward (1938 studied for his well-known model of sodo-political organiza­tion and evolution (Steward 1955; also see Service 1975, Jesse Jennings (1957 later used Steward's model in his development of the Desert Culture concept, which was widely adapted to other North America deserts.

  19. Global Strategic Mobility: A Decade After Desert Storm. Are We More Capable?

    Science.gov (United States)

    2007-11-02

    USAWC STRATEGY RESEARCH PROJECT GLOBAL STRATEGIC MOBILITY: A DECADE AFTER DESERT STORM. ARE WE MORE CAPABLE? by Lieutenant Colonel Dean A. Nelson...2. REPORT TYPE 3. DATES COVERED (FROM - TO) xx-xx-2002 to xx-xx-2003 4. TITLE AND SUBTITLE Global Strategic Mobility: A Decade After Desert Storm. Are...Air Force TITLE: GLOBAL STRATEGIC MOBILITY: A DECADE AFTER DESERT STORM. ARE WE MORE CAPABLE? FORMAT: Strategy Research Project DATE: 30 January 2003

  20. Vegetation analysis and soil characteristics of five common desert climbing plants in Egypt

    OpenAIRE

    El-Ghani, Monier Abd; EL-KHEIR, Mahmoud ABO; ABDEL-DAYEM, Mahmoud

    2011-01-01

    This study aimed to characterise Egyptian desert vine flora and compare it with that of deserts in other continents, such as Australia and North America. Specifically, 5 common climbing desert plants (Citrullus colocynthis, Cocculus pendulus, Cucumis prophetarum, Pergularia tomentosa, and Periploca angustifolia) were selected for this study. The floristic composition, vegetation heterogeneity, and chorological affinities of the associated species of the studied climbing plants were quantitati...

  1. Validation and Development of a Certification Program for Using K9s to Survey Desert Tortoises

    Science.gov (United States)

    2013-08-01

    Esque, and K. Nussear. Humans vs. K9s: Is fear warranted in the race to save the desert tortoise? 91st Annual Ecological Society of America , August 6-11...desert tortoises, other reptiles (Schwartz et al., 1984; Engeman et al., 1998), or even to 10 distinguish cancer in human subjects (McCulloch et...has yet to be validated in mammals. Therefore, it is not possible to explain precisely how dogs use scent to find desert tortoises, other reptiles

  2. Paleowetlands and regional climate change in the central Atacama Desert, northern Chile

    Science.gov (United States)

    Quade, Jay; Rech, Jason A.; Betancourt, Julio L.; Latorre, Claudio; Quade, Barbra; Rylander, Kate Aasen; Fisher, Timothy

    2008-01-01

    Widespread, organic-rich diatomaceous deposits are evidence for formerly wetter times along the margins of the central Atacama Desert, one of the driest places on Earth today. We mapped and dated these paleowetland deposits at three presently waterless locations near Salar de Punta Negra (24.5°S) on the western slope of the Andes. Elevated groundwater levels supported phreatic discharge into wetlands during two periods: 15,900 to ~ 13,800 and 12,700 to ~ 9700 cal yr BP. Dense concentrations of lithic artifacts testify to the presence of paleoindians around the wetlands late in the second wet phase (11,000?–9700 cal yr BP). Water tables dropped below the surface before 15,900 and since 8100 cal yr BP, and briefly between ~ 13,800 and 12,700 cal yr BP. This temporal pattern is repeated, with some slight differences, in rodent middens from the study area, in both paleowetland and rodent midden deposits north and south of the study area, and in lake level fluctuations on the adjacent Bolivian Altiplano. The regional synchroneity of these changes points to a strengthening of the South American Monsoon — which we term the "Central Andean Pluvial Event" — in two distinct intervals (15,900–13,800 and 12,700–9700 cal yr BP), probably induced by steepened SST gradients across the tropical Pacific (i.e., La Niña-like conditions).

  3. Impact of Empire Expansion on Household Diet: The Inka in Northern Chile's Atacama Desert

    Science.gov (United States)

    Vinton, Sheila Dorsey; Perry, Linda; Reinhard, Karl J.; Santoro, Calogero M.; Teixeira-Santos, Isabel

    2009-01-01

    The impact of expanding civilization on the health of American indigenous societies has long been studied. Most studies have focused on infections and malnutrition that occurred when less complex societies were incorporated into more complex civilizations. The details of dietary change, however, have rarely been explored. Using the analysis of starch residues recovered from coprolites, here we evaluate the dietary adaptations of indigenous farmers in northern Chile's Atacama Desert during the time that the Inka Empire incorporated these communities into their economic system. This system has been described as “complementarity” because it involves interaction and trade in goods produced at different Andean elevations. We find that as local farming societies adapted to this new asymmetric system, a portion of their labor had to be given up to the Inka elite through a corvée tax system for maize production. In return, the Inka system of complementarity introduced previously rare foods from the Andean highlands into local economies. These changes caused a disruption of traditional communities as they instituted a state-level economic system on local farmers. Combined with previously published infection information for the same populations under Inka rule, the data suggest that there may have been a dual health impact from disruption of nutrition and introduction of crowd disease. PMID:19956668

  4. The stratigraphic record of changing hyperaridity in the Atacama desert over the last 10 Ma

    Science.gov (United States)

    Sáez, Alberto; Cabrera, Lluís; Garcés, Miguel; Bogaard, Paul van den; Jensen, Arturo; Gimeno, Domingo

    2012-11-01

    New radiometric and magnetostratigraphic data from Quillagua and Calama basins (Atacama desert) indicate that the stratigraphic record over the last 10 Ma includes two hiatuses, lasting approximately 2 and 4 million years respectively. These sedimentary gaps are thought to represent prolonged periods of hyperaridity in the region, with absence of sediment production and accumulation in the central depressions. Their remarkable synchrony with Antarctic and Patagonian glacial stages, Humboldt cold current enhancement and cold upwelling waters lead us to suggest long-term climate forcing. Higher frequency climate (orbital precession and eccentricity) forcing is thought to control the sequential arrangement of the lacustrine units deposited at times of lower aridity. Hyperaridity trends appear to be modulated by the activity of the South American Summer Monsoon, which drives precipitation along the high altitude areas to the east of Atacama. This precipitation increase combined with the eastward enlargement of the regional drainage during the late Pleistocene enabled water transfer from these high altitude areas to the low lying closed Quillagua basin and resulted in the deposition of the last widespread saline lacustrine deposits in this depression, before its drainage was open to the Pacific Ocean.

  5. Impact of empire expansion on household diet: the Inka in Northern Chile's Atacama Desert.

    Directory of Open Access Journals (Sweden)

    Sheila Dorsey Vinton

    Full Text Available The impact of expanding civilization on the health of American indigenous societies has long been studied. Most studies have focused on infections and malnutrition that occurred when less complex societies were incorporated into more complex civilizations. The details of dietary change, however, have rarely been explored. Using the analysis of starch residues recovered from coprolites, here we evaluate the dietary adaptations of indigenous farmers in northern Chile's Atacama Desert during the time that the Inka Empire incorporated these communities into their economic system. This system has been described as "complementarity" because it involves interaction and trade in goods produced at different Andean elevations. We find that as local farming societies adapted to this new asymmetric system, a portion of their labor had to be given up to the Inka elite through a corvée tax system for maize production. In return, the Inka system of complementarity introduced previously rare foods from the Andean highlands into local economies. These changes caused a disruption of traditional communities as they instituted a state-level economic system on local farmers. Combined with previously published infection information for the same populations under Inka rule, the data suggest that there may have been a dual health impact from disruption of nutrition and introduction of crowd disease.

  6. African-American Biography.

    Science.gov (United States)

    Martin, Ron

    1995-01-01

    Suggests sources of information for African American History Month for library media specialists who work with students in grades four through eight. Gale Research's "African-American Reference Library," which includes "African-America Biography,""African-American Chronology," and "African-American Almanac,"…

  7. Species composition,distribution patterns and ecological functions of biological soil crusts in the Gurbantunggut Desert

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    As one of the most important biological factors that maintain the stability of the largest fixed and semi-fixed desert in China,the Gurbantunggut Desert,the biological soil crusts (BSCs) develop well and play critical ecological roles in the desert ecosystem. In this paper,we briefly summarize our research findings since 2002 including species composition,distribution pattern and ecological functions of BSCs in the desert. Our results indicate abundant species diversity of BSCs in the Gurbantunggut Desert in comparison to other deserts in China. At the scales of sand dune or whole desert,the distribution patterns of BSCs are location-specific. The existence of BSCs in this desert could:(1) accelerate the formation of desert soil and the weathering of minerals; (2) accumulate organic matter in surface soil through related species in soil crusts; (3) enhance the abilities of sand surface to resist wind erosion; (4) influence seed germination of vascular plants; and (5) enhance the production of dew deposition on sandy soil surface.

  8. Study on the Land Reclamation of Oilfield of Gurbantunggut Desert in Junggar Basin

    Institute of Scientific and Technical Information of China (English)

    Liang; LI; Xuezhong; ZHENG; Xusheng; SHAO; Caichuan; WANG; Min; Xu

    2013-01-01

    The exploration and development of oilfield results in damages to land resources. Along with the further development of petroleum in the Gurbantunggut Desert, the fragile ecological environment and land resource was suffering much more damage. Vegetation degradation and desertification become more prominent. In response to the damage to the fragile ecological environment and oilfield in the Gurbantunggut Desert, limit condition method was used to evaluate the suitability of land reclamation suitability. Results suggested that the main restraining factors for land reclamation were soil condition and water resources. Based on the effect and shortage of oilfield in the Gurbantunggut Desert Oilfield, the reclamation of oilfield in the Gurbantunggut desert was discussed.

  9. Epifluorescent direct counts of bacteria and viruses from topsoil of various desert dust storm regions

    Science.gov (United States)

    Gonzalez-Martin, Cristina; Teigell-Perez, Nuria; Lyles, Mark; Valladares, Basilio; Griffin, Dale W.

    2013-01-01

    Topsoil from arid regions is the main source of dust clouds that move through the earth's atmosphere, and microbial communities within these soils can survive long-range dispersion. Microbial abundance and chemical composition were analyzed in topsoil from various desert regions. Statistical analyses showed that microbial direct counts were strongly positively correlated with calcium concentrations and negatively correlated with silicon concentrations. While variance between deserts was expected, it was interesting to note differences between sample sites within a given desert region, illustrating the 'patchy' nature of microbial communities in desert environments.

  10. On scientific expedition tourism of desert region: a case of eastern Ulan Buh Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Desert-based adventure tourism is a rapidly expanding tourism market segment after the late 20th century around the world.Perhaps the most significant factor in the development of desert adventure tourism is the extent to which common tourists are really engaged in scientific expedition.Inner Mongolia has long been considered as the resources accumulation area of desert tourism.The investigation on the Ulan Buh Desert has discovered that the desert animals,the vegetation,the insects,the fungus,the landform and the climate are impressive for both the researchers and the mass tourists.After the resources investigation a survey was carried out in 2007 to get the detailed information of the tourists attitude toward the planning desert scientific product in the Ulan Buh Desert.Based on the resources and market analysis,this paper tries to make a planning of the desert scientific expedition tour of the Ulan Buh Desert.The planning includes the functional division,expedition route design,tour-explaining system,facility of safety guaranty and service planning,and the professional training base.

  11. Regular Cosmogenic Nuclide Dosing of Sediment Moving Down Desert Piedmonts

    Science.gov (United States)

    Nichols, K. K.; Bierman, P. R.; Hooke, R. L.; Eppes, M. C.; Persico, L.; Caffee, M.; Finkel, R.

    2001-12-01

    Low-gradient alluvial piedmonts are common in desert areas throughout the world; however, long-term rates of processes that modify these landscapes are poorly understood. Using cosmogenic 10Be and 26Al, we attempt to quantify the long-term (>103 y) behavior of desert piedmonts in Southern California. We measured the activity of 10Be and 26Al in three samples of drainage basin alluvium and six amalgamated samples from transects spaced at 1-km intervals down a piedmont in Fort Irwin, Mojave Desert, California. Each transect sample consists of sediment from 21 collection sites spaced at 150 m intervals. Such sampling averages the variability of nuclide activity between sub-sample locations and thus gives a long-term dosing history of sediment as it is transported from uplands to the distal piedmont. The piedmont is heavily used during military training exercises during which hundreds of wheeled and tracked vehicles traverse the surface. The piedmont surface is planar, and fan-head incision is minimal at the rangefront decreasing to zero between the first and second transects, 1.5 km from the rangefront. 10Be activity increases steadily from 5.87 X 105 atoms g-1 at the rangefront to 1.02 X 6 atoms g-1 at the piedmont bottom. Nuclide activity and distance are well correlated (r2 = 0.95) suggesting that sediment is dosed uniformly as it is transported down piedmont. We have measured similar increases in nuclide activity in transect samples collected from two other Mojave Desert piedmonts, those fringing the Iron and Granite Mountains (Nichols et al, in press, Geomorphology). These piedmonts have nuclide activities that also correlate well with distance (r2 = 0.98 and 0.96, respectively) from their rangefronts, but nuclides increase at a lower rate down piedmont. Modeled sediment transport speeds for the Iron and Granite Mountain piedmonts are decimeters per year. The regular increase in nuclide activities down three different Mojave Desert piedmonts suggests that

  12. Fire Impacts on the Mojave Desert Ecosystem: Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Fenstermaker Lynn

    2012-01-01

    The Nevada National Security Site (NNSS) is located within the Mojave Desert, which is the driest region in North America. Precipitation on the NNSS varies from an annual average of 130 millimeters (mm; 5.1 inches) with a minimum of 47 mm (1.9 inches) and maximum of 328 mm (12.9 inches) over the past 15 year period to an annual average of 205 mm (8.1 inches) with an annual minimum of 89 mm (3.5 inches) and maximum of 391 mm (15.4 inches) for the same time period; for a Frenchman Flat location at 970 meters (m; 3182 feet) and a Pahute Mesa location at 1986 m (6516 feet), respectively. The combination of aridity and temperature extremes has resulted in sparsely vegetated basins (desert shrub plant communities) to moderately vegetated mountains (mixed coniferous forest plant communities); both plant density and precipitation increase with increasing elevation. Whereas some plant communities have evolved under fire regimes and are dependent upon fire for seed germination, plant communities within the Mojave Desert are not dependent on a fire regime and therefore are highly impacted by fire (Brown and Minnich, 1986; Brooks, 1999). As noted by Johansen (2003) natural range fires are not prevalent in the Mojave and Sonoran Deserts because there is not enough vegetation present (too many shrub interspaces) to sustain a fire. Fire research and hence publications addressing fires in the Southwestern United States (U.S.) have therefore focused on forest, shrub-steppe and grassland fires caused by both natural and anthropogenic ignition sources. In the last few decades, however, invasion of mid-elevation shrublands by non-native Bromus madritensis ssp. rubens and Bromus tectorum (Hunter, 1991) have been highly correlated with increased fire frequency (Brooks and Berry, 2006; Brooks and Matchett, 2006). Coupled with the impact of climate change, which has already been shown to be playing a role in increased forest fires (Westerling et al., 2006), it is likely that the fire

  13. Potential for deserts to supply reliable renewable electric power

    Science.gov (United States)

    Labordena, Mercè; Lilliestam, Johan

    2015-04-01

    To avoid dangerous climate change, the electricity systems must be decarbonized by mid-century. The world has sufficient renewable electricity resources for complete power sector decarbonization, but an expansion of renewables poses several challenges for the electricity systems. First, wind and solar PV power are intermittent and supply-controlled, making it difficult to securely integrate this fluctuating generation into the power systems. Consequently, power sources that are both renewable and dispatchable, such as biomass, hydro and concentrating solar power (CSP), are particularly important. Second, renewable power has a low power density and needs vast areas of land, which is problematic both due to cost reasons and due to land-use conflicts, in particular with agriculture. Renewable and dispatchable technologies that can be built in sparsely inhabited regions or on land with low competition with agriculture would therefore be especially valuable; this land-use competition greatly limits the potential for hydro and biomass electricity. Deserts, however, are precisely such low-competition land, and are at the same time the most suited places for CSP generation, but this option would necessitate long transmission lines from remote places in the deserts to the demand centers such as big cities. We therefore study the potential for fleets of CSP plants in the large deserts of the world to produce reliable and reasonable-cost renewable electricity for regions with high and/or rapidly increasing electricity demand and with a desert within or close to its borders. The regions in focus here are the European Union, North Africa and the Middle East, China and Australia. We conduct the analysis in three steps. First, we identify the best solar generation areas in the selected deserts using geographic information systems (GIS), and applying restrictions to minimize impact on biodiversity, soils, human heath, and land-use and land-cover change. Second, we identify

  14. Compte rendu de: Maggie Morrow, Mike Morrow, Tony Judd, & Geoff Phillipson 2010. Desert RATS. Rock Art Topographical Survey in Egypt's Eastern Desert. Oxford: BAR International Series 2166, 254 p.

    OpenAIRE

    Le Quellec, Jean-Loïc

    2011-01-01

    International audience; Compte rendu de: Maggie Morrow, Mike Morrow, Tony Judd, & Geoff Phillipson 2010. Desert RATS. Rock Art Topographical Survey in Egypt's Eastern Desert. Oxford: BAR International Series 2166, 254 p.

  15. Southwest Indian Ocean Bathymetric Compilation (swIOBC)

    Science.gov (United States)

    Jensen, L.; Dorschel, B.; Arndt, J. E.; Jokat, W.

    2014-12-01

    As result of long-term scientific activities in the southwest Indian Ocean, an extensive amount of swath bathymetric data has accumulated in the AWI database. Using this data as a backbone, supplemented by additional bathymetric data sets and predicted bathymetry, we generate a comprehensive regional bathymetric data compilation for the southwest Indian Ocean. A high resolution bathymetric chart of this region will support geological and climate research: Identification of current-induced seabed structures will help modelling oceanic currents and, thus, provide proxy information about the paleo-climate. Analysis of the sediment distribution will contribute to reconstruct the erosional history of Eastern Africa. The aim of swIOBC is to produce a homogeneous and seamless bathymetric grid with an associated meta-database and a corresponding map for the area from 5° to 39° S and 20° to 44° E. Recently, multibeam data with a track length of approximately 86,000 km are held in-house. In combination with external echosounding data this allows for the generation of a regional grid, significantly improving the existing, mostly satellite altimetry derived, bathymetric models. The collected data sets are heterogeneous in terms of age, acquisition system, background data, resolution, accuracy, and documentation. As a consequence, the production of a bathymetric grid requires special techniques and algorithms, which were already developed for the IBCAO (Jakobsson et al., 2012) and further refined for the IBCSO (Arndt et al., 2013). The new regional southwest Indian Ocean chart will be created based on these methods. Arndt, J.E., et al., 2013. The International Bathymetric Chart of the Southern Ocean (IBCSO) Version 1.0—A new bathymetric compilation covering circum-Antarctic waters. GRL 40, 1-7, doi: 10.1002/grl.50413, 2013. Jakobsson, M., et al., 2012. The International Bathymetric Chart of the Arctic Ocean (IBCAO) Version 3.0. GRL 39, L12609, doi: 10.1029/2012GL052219.

  16. Phylogeographic study of Apodemus ilex (Rodentia: Muridae in Southwest China.

    Directory of Open Access Journals (Sweden)

    Qi Liu

    Full Text Available BACKGROUND: The Mountains of southwest China have complex river systems and a profoundly complex topography and are among the most important biodiversity hotspots in the world. However, only a few studies have shed light on how the mountains and river valleys promote genetic diversity. Apodemus ilex is a fine model for investigating this subject. METHODOLOGY/PRINCIPAL FINDINGS: To assess the genetic diversity and biogeographic patterns of Apodemus ilex, the complete cytochrome b gene sequences (1,140 bp were determined from 203 samples of A. draco/ilex that were collected from southwest China. The results obtained suggested that A. ilex and A. draco are sistergroups and diverged from each other approximately 2.25 million years ago. A. ilex could be divided into Eastern and Western phylogroups, each containing two sub-groups and being widespread in different geographical regions of the southern Hengduan Mountains and the western Yunnan - Guizhou Plateau. The population expansions of A. ilex were roughly from 0.089 Mya to 0.023 Mya. CONCLUSIONS: Our result suggested that A. ilex is a valid species rather than synonym of A. draco. As a middle-high elevation inhabitant, the phylogenetic pattern of A. ilex was strongly related to the complex geographical structures in southwest China, particularly the existence of deep river valley systems, such as the Mekong and Salween rivers. Also, it appears that the evolutionary history of A. ilex, such as lineage divergences and population expansions were strongly affected by climate fluctuation in the Late Pleistocene.

  17. Diet diversity and nutritional status among adults in southwest China

    Science.gov (United States)

    Zhang, Qiang; Chen, Xinguang; Liu, Zhitao; Varma, Deepthi S.; Wan, Rong

    2017-01-01

    Background With rapid urbanization in the past decades, diet diversity continues to increase in China. The present cross-sectional study aims to explore the association between dietary diversity and nutritional status among adults in southwest China. Methods This study used data from 2011–2012 National Nutritional Survey in Yunnan Province, southwest China (N = 1105).Data of three consecutive 24-hour dietary recalls were used to calculate dietary diversity scores (DDS) and nutrient adequacy ratio (NAR). Body mass index and waist circumference were used to determine nutritional status. Surveylogistic procedure of SAS 9.2 software was used to examine the association between DDS and obesity by estimating odds ratio (OR) and 95% confidence intervals (CI). Results The mean DDS was 5.2 (SD 1.1) out of nine points. Being female, younger age, belonging to Han ethnicity, having higher educational level and household income were positively associated with DDS (all Pconsumption also increased in most food groups except grains and vegetables. People with medium and high DDS (DDS = 5 and DDS ≥6, respectively) ingested more energy than the recommended quantity(NAR = 1.1 and 1.2, respectively). However, the intakes of Calcium and Vitamin A were seriously inadequate even for people with high DDS (NAR≤0.5). With potential confounders adjusted, people with medium and high DDS were at higher risk of general and central obesity than people with DDS ≤4 (OR = 1.4–1.9, P<0.01). Conclusions Our data indicated that high DDS was associated with excessive energy intake and obesity among adults in southwest China. Although dietary diversity is widely recommended, public health messages should give less emphasis on dietary diversity. PMID:28231308

  18. Parallel Study on Potential and Existing Geographical Distribution of Haloxylon Dominated Desert Vegetation in China

    Institute of Scientific and Technical Information of China (English)

    GUO Quanshui; WANG Chunling; TAN Deyuan; MA Chao; WANG Xiangfu; HAO Jianxi; HE Hongyan

    2006-01-01

    By applying ARC/INFO(NT version)of the GIS software package,we extracted the existing geographical distribution of Haloxylon dominated desert vegetation and produced a thematic map of geographical distribution of the existing Haloxylon dominated desert vegetation based on the newly published Vegetation Atlas of China;we defined the adaptive parameter range of geographical and climate of Haloxylon dominated desert vegetation to generate the potential geographical distribution map of Haloxylon dominated desert vegetation with the support of GREEN software.We then sliced and compared the existing and the potential distribution maps.The results show that the potential geographical distribution areas of Haloxylon ammodendron and Haloxylon persicum dominated desert vegetation accord with the existing distribution areas in the administration division,and the topographic types in both the distribution areas are similar.However,the borders of different directions of the potential H.ammodendron dominated desert vegetation distribution has surpassed 0.4°to 5.9°of the existing borders.The borders of different directions of the potential H. persicum dominated desert vegetation has surpassed 0.9°to 3.3°of the existing borders.In China,the existing geographical distributional area of H.ammodendron dominated desert vegetation accounts for 9.1% of the potential one in China and the proportion of the existing H.persicum dominated desert vegetation distribution area to the potential area is 34.1%.The result of comparison of the potential and the existing distribution area of Haloxylon dominated desert vegetation can provide important scientific basis for the recovery,reconstruction and introduction of Haloxylon dominated desert vegetation.

  19. The potential of tourism in the Region of Southwest Oltenia

    Directory of Open Access Journals (Sweden)

    Laurenţiu Radu

    2016-12-01

    Full Text Available This study is based on cultural and historical importance of Southwest Oltenia. The region has an attractive potential for tourism development, turning to its advantage both the strategic geographic location and the natural wealth of the Carpathians and the Danube River. Identifying products and services that make up the composition of tourism as a brand is a priority to create an image that can capture the attention of potential investors, travelers and tourists. Analyzing the profile of Oltenia’s tourism offer, we can say that the region provides the most varied forms of tourism

  20. Modern tectonic stress field in Southwest Yunnan, China

    Institute of Scientific and Technical Information of China (English)

    谢富仁; 苏刚; 崔效锋; 舒赛兵; 赵建涛

    2001-01-01

    By means of inversion of fault slip data, the parameters of 20 tectonic stress tensors in Southwest Yunnan region are determined. Compared with the average stress field of the region obtained from focal mechanism solutions, the following characteristics of modern tectonic stress field in this region are obtained. From the west of Zhenyuan- Yingpanshan fault to the south of Longling fault zone, the maximum compressional stress is in NNE direction and the stress regime is mainly of strike-slip type. In Longling fault zone and the area north to it, the direction of maximum compressional stress is near-NS or NNW, the stress regime is of strike-slip type.

  1. Cenozoic tectonic reorganizations of the Death Valley region, southeast California and southwest Nevada

    Science.gov (United States)

    Fridrich, Christopher J.; Thompson, Ren A.

    2011-01-01

    stepped westward during three successive tectonic reorganizations that intervened between four stages of basin-range tectonism, the youngest of which is ongoing. These three tectonic reorganizations also intervened between four stages of volcanic activity, each of which has been distinct in the compositions of magmas erupted, in eruption rates, and in the locus of volcanic activity—which has stepped progressively westward, in close coordination with the step-wise migrations in the locus of basin-range extension. The timing of the Cenozoic tectonic reorganizations in the Death Valley region correlates closely with the documented timing of episodic reorganizations of the boundary between the Pacific and North American plates, to the west and southwest. This supports models that explain the widely distributed transtensional tectonism in southwestern North America since approximately 40 million years ago as resulting from traction imposed by the adjacent, divergent Pacific plate.

  2. Deserts of the southwestern United States, for the Death Valley regional ground-water flow system study, Nevada and California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital data set defines the boundaries of the deserts of the southwestern United States. Those deserts include the Great Basin, Mojave, Colorado, and Sonoran...

  3. Virome Assembly and Annotation: A Surprise in the Namib Desert

    Science.gov (United States)

    Hesse, Uljana; van Heusden, Peter; Kirby, Bronwyn M.; Olonade, Israel; van Zyl, Leonardo J.; Trindade, Marla

    2017-01-01

    Sequencing, assembly, and annotation of environmental virome samples is challenging. Methodological biases and differences in species abundance result in fragmentary read coverage; sequence reconstruction is further complicated by the mosaic nature of viral genomes. In this paper, we focus on biocomputational aspects of virome analysis, emphasizing latent pitfalls in sequence annotation. Using simulated viromes that mimic environmental data challenges we assessed the performance of five assemblers (CLC-Workbench, IDBA-UD, SPAdes, RayMeta, ABySS). Individual analyses of relevant scaffold length fractions revealed shortcomings of some programs in reconstruction of viral genomes with excessive read coverage (IDBA-UD, RayMeta), and in accurate assembly of scaffolds ≥50 kb (SPAdes, RayMeta, ABySS). The CLC-Workbench assembler performed best in terms of genome recovery (including highly covered genomes) and correct reconstruction of large scaffolds; and was used to assemble a virome from a copper rich site in the Namib Desert. We found that scaffold network analysis and cluster-specific read reassembly improved reconstruction of sequences with excessive read coverage, and that strict data filtering for non-viral sequences prior to downstream analyses was essential. In this study we describe novel viral genomes identified in the Namib Desert copper site virome. Taxonomic affiliations of diverse proteins in the dataset and phylogenetic analyses of circovirus-like proteins indicated links to the marine habitat. Considering additional evidence from this dataset we hypothesize that viruses may have been carried from the Atlantic Ocean into the Namib Desert by fog and wind, highlighting the impact of the extended environment on an investigated niche in metagenome studies. PMID:28167933

  4. Sympatric cattle grazing and desert bighorn sheep foraging

    Science.gov (United States)

    Garrison, Kyle R.; Cain, James W.; Rominger, Eric M.; Goldstein, Elise J.

    2015-01-01

    Foraging behavior affects animal fitness and is largely dictated by the resources available to an animal. Understanding factors that affect forage resources is important for conservation and management of wildlife. Cattle sympatry is proposed to limit desert bighorn population performance, but few studies have quantified the effect of cattle foraging on bighorn forage resources or foraging behavior by desert bighorn. We estimated forage biomass for desert bighorn sheep in 2 mountain ranges: the cattle-grazed Caballo Mountains and the ungrazed San Andres Mountains, New Mexico. We recorded foraging bout efficiency of adult females by recording feeding time/step while foraging, and activity budgets of 3 age-sex classes (i.e., adult males, adult females, yearlings). We also estimated forage biomass at sites where bighorn were observed foraging. We expected lower forage biomass in the cattle-grazed Caballo range than in the ungrazed San Andres range and lower biomass at cattle-accessible versus inaccessible areas within the Caballo range. We predicted bighorn would be less efficient foragers in the Caballo range. Groundcover forage biomass was low in both ranges throughout the study (Jun 2012–Nov 2013). Browse biomass, however, was 4.7 times lower in the Caballo range versus the San Andres range. Bighorn in the Caballo range exhibited greater overall daily travel time, presumably to locate areas of higher forage abundance. By selecting areas with greater forage abundance, adult females in the Caballo range exhibited foraging bout efficiency similar to their San Andres counterparts but lower overall daily browsing time. We did not find a significant reduction in forage biomass at cattle-accessible areas in the Caballo range. Only the most rugged areas in the Caballo range had abundant forage, potentially a result of intensive historical livestock use in less rugged areas. Forage conditions in the Caballo range apparently force bighorn to increase foraging effort by

  5. Desert bighorn sheep lambing habitat: Parturition, nursery, and predation sites

    Science.gov (United States)

    Karsch, Rebekah C.; Cain, James W.; Rominger, Eric M.; Goldstein, Elise J.

    2016-01-01

    Fitness of female ungulates is determined by neonate survival and lifetime reproductive success. Therefore, adult female ungulates should adopt behaviors and habitat selection patterns that enhance survival of neonates during parturition and lactation. Parturition site location may play an important role in neonatal mortality of desert bighorn sheep (Ovis canadensis mexicana) when lambs are especially vulnerable to predation, but parturition sites are rarely documented for this species. Our objectives were to assess environmental characteristics at desert bighorn parturition, lamb nursery, and predation sites and to assess differences in habitat characteristics between parturition sites and nursery group sites, and predation sites and nursery group sites. We used vaginal implant transmitters (VITs) to identify parturition sites and capture neonates. We then compared elevation, slope, terrain ruggedness, and visibility at parturition, nursery, and lamb predation sites with paired random sites and compared characteristics of parturition sites and lamb predation sites to those of nursery sites. When compared to random sites, odds of a site being a parturition site were highest at intermediate slopes and decreased with increasing female visibility. Odds of a site being a predation site increased with decreasing visibility. When compared to nursery group sites, odds of a site being a parturition site had a quadratic relationship with elevation and slope, with odds being highest at intermediate elevations and intermediate slopes. When we compared predation sites to nursery sites, odds of a site being a predation were highest at low elevation areas with high visibility and high elevation areas with low visibility likely because of differences in hunting strategies of coyote (Canis latrans) and puma (Puma concolor). Parturition sites were lower in elevation and slope than nursery sites. Understanding selection of parturition sites by adult females and how habitat

  6. Spectral identification and quantification of salts in the Atacama Desert

    Science.gov (United States)

    Harris, J. K.; Cousins, C. R.; Claire, M. W.

    2016-10-01

    Salt minerals are an important natural resource. The ability to quickly and remotely identify and quantify salt deposits and salt contaminated soils and sands is therefore a priority goal for the various industries and agencies that utilise salts. The advent of global hyperspectral imagery from instruments such as Hyperion on NASA's Earth-Observing 1 satellite has opened up a new source of data that can potentially be used for just this task. This study aims to assess the ability of Visible and Near Infrared (VNIR) spectroscopy to identify and quantify salt minerals through the use of spectral mixture analysis. The surface and near-surface soils of the Atacama Desert in Chile contain a variety of well-studied salts, which together with low cloud coverage, and high aridity, makes this region an ideal testbed for this technique. Two forms of spectral data ranging 0.35 - 2.5 μm were collected: laboratory spectra acquired using an ASD FieldSpec Pro instrument on samples from four locations in the Atacama desert known to have surface concentrations of sulfates, nitrates, chlorides and perchlorates; and images from the EO-1 satellite's Hyperion instrument taken over the same four locations. Mineral identifications and abundances were confirmed using quantitative XRD of the physical samples. Spectral endmembers were extracted from within the laboratory and Hyperion spectral datasets and together with additional spectral library endmembers fed into a linear mixture model. The resulting identification and abundances from both dataset types were verified against the sample XRD values. Issues of spectral scale, SNR and how different mineral spectra interact are considered, and the utility of VNIR spectroscopy and Hyperion in particular for mapping specific salt concentrations in desert environments is established. Overall, SMA was successful at estimating abundances of sulfate minerals, particularly calcium sulfate, from both hyperspectral image and laboratory sample spectra

  7. Virome Assembly and Annotation: A Surprise in the Namib Desert.

    Science.gov (United States)

    Hesse, Uljana; van Heusden, Peter; Kirby, Bronwyn M; Olonade, Israel; van Zyl, Leonardo J; Trindade, Marla

    2017-01-01

    Sequencing, assembly, and annotation of environmental virome samples is challenging. Methodological biases and differences in species abundance result in fragmentary read coverage; sequence reconstruction is further complicated by the mosaic nature of viral genomes. In this paper, we focus on biocomputational aspects of virome analysis, emphasizing latent pitfalls in sequence annotation. Using simulated viromes that mimic environmental data challenges we assessed the performance of five assemblers (CLC-Workbench, IDBA-UD, SPAdes, RayMeta, ABySS). Individual analyses of relevant scaffold length fractions revealed shortcomings of some programs in reconstruction of viral genomes with excessive read coverage (IDBA-UD, RayMeta), and in accurate assembly of scaffolds ≥50 kb (SPAdes, RayMeta, ABySS). The CLC-Workbench assembler performed best in terms of genome recovery (including highly covered genomes) and correct reconstruction of large scaffolds; and was used to assemble a virome from a copper rich site in the Namib Desert. We found that scaffold network analysis and cluster-specific read reassembly improved reconstruction of sequences with excessive read coverage, and that strict data filtering for non-viral sequences prior to downstream analyses was essential. In this study we describe novel viral genomes identified in the Namib Desert copper site virome. Taxonomic affiliations of diverse proteins in the dataset and phylogenetic analyses of circovirus-like proteins indicated links to the marine habitat. Considering additional evidence from this dataset we hypothesize that viruses may have been carried from the Atlantic Ocean into the Namib Desert by fog and wind, highlighting the impact of the extended environment on an investigated niche in metagenome studies.

  8. Phylogeography of Libanotis buchtormensis (Umbelliferae) in Disjunct Populations along the Deserts in Northwest China

    Science.gov (United States)

    Wang, Ping; Zhang, Xianzhi; Tang, Nan; Liu, Jianjun; Xu, Langran; Wang, Kai

    2016-01-01

    In Northwest China, aridification and desert expansion play significant roles in promoting desert plant diversification and speciation. However, to date, little is known about the effects of the desert barrier on the population structure of montane, non-desert species in the area. In this study, we sequenced chloroplast DNA regions (trnL–trnF and trnS–trnG) and a nuclear gene (rpb2) to investigate the population differentiation and phylogeographical history of Libanotis buchtormensis, a perennial montane species possessing a disjunct distribution at the periphery of the central desert. In total, 23 chloroplast haplotypes and 24 nuclear haplotypes were recovered from the 21 natural populations and six hebarium specimens. Phylogenetic analysis based on the combined plastid and nuclear dataset revealed two distinct lineages of L. buchtormensis, which inhabit the disjunct areas on both sides of the desert zone. The molecular dating analysis indicated that the divergence between the southeastern and the northwestern populations occurred in the middle Pleistocene, concomitantly with the desert expansion. The geographical vicariance likely contributed to the present disjunct distribution of L. buchtormensis across the deserts in Northwest China. Populations in the southeastern region may have migrated from the northwestern region, and seem to be a peripheral distribution of L. buchtormensis. PMID:27442136

  9. TEST AND STUDY ON THE CONSTITUTIVE RELATIONSHIP OF DESERT SAND UNDER MOVING VEHICLE

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The mechanical properties of the sand of Takelamagan desert in Xinjiang under moving vehicle are studied by soil dynamic triaxial test apparatus. The nonlinear elastic constitutive model of the sand under moving vehicle is established first. These results lay the foundations for studying the interaction between vehicle running gear and the sand of Takelamagan desert in Xinjiang. and developing sand vehicle.

  10. 77 FR 11992 - Revisions to the California State Implementation Plan, Mojave Desert Air Quality Management District

    Science.gov (United States)

    2012-02-28

    ... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Mojave Desert Air Quality Management District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing a limited approval and limited disapproval of revisions to the Mojave Desert Air...

  11. 76 FR 29182 - Revisions to the California State Implementation Plan, Mojave Desert Air Quality Management District

    Science.gov (United States)

    2011-05-20

    ... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Mojave Desert Air Quality Management District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the Mojave Desert Air Quality Management District (MDAQMD) portion of...

  12. Reconstructing the origin of Helianthus deserticola: Survival and selection on the desert floor

    NARCIS (Netherlands)

    Gross, B.L.; Kane, D.L.; Lexer, C.; Ludwig, F.; Rosenthal, D.R.; Donovan, L.A.; Rieseberg, L.H.

    2004-01-01

    The diploid hybrid species Helianthus deserticola inhabits the desert floor, an extreme environment relative to its parental species Helianthus annuus and Helianthus petiolaris. Adaptation to the desert floor may have occurred via selection acting on transgressive, or extreme, traits in early hybrid

  13. Should I stay or should I go? Female brood desertion and male counterstrategy in rock sparrows

    DEFF Research Database (Denmark)

    Griggio, Matteo; Matessi, Giuliano; Pilastro, Andrea

    2005-01-01

    Brood desertion involves a series of interactions between the members of a pair. This process is likely to be based on either member's perception of the other's propensity to desert. We manipulated this perception in males by experimentally increasing female body mass in the rock sparrow (Petroni...

  14. Sexual conflict over parental care in Penduline Tits Remiz pendulinus : the process of clutch desertion

    NARCIS (Netherlands)

    Van Dijk, Rene; Szentirmai, Istvan; Komdeur, Jan; Szekely, Tamas

    2007-01-01

    Do the two parents at a nest make simultaneous decisions whether to care for their offspring or to desert? If a single parent is sufficient for rearing young, one parent (typically, the male) may desert and reproduce with a new mate within the same breeding season, leaving the other parent with the

  15. Spatial probability models of fire in the desert grasslands of the southwestern USA

    Science.gov (United States)

    Fire is an important driver of ecological processes in semiarid environments; however, the role of fire in desert grasslands of the Southwestern US is controversial and the regional fire distribution is largely unknown. We characterized the spatial distribution of fire in the desert grassland region...

  16. Mineral contents from some fabaceous plant species of Rajasthan desert

    Directory of Open Access Journals (Sweden)

    B.B.S.Kapoor

    2013-12-01

    Full Text Available Evaluation of mineral contents from three selected plant species of Fabaceae family growing in arid region of Rajasthan Desert was carried out. The roots, shoots and fruits of Clitoria ternatea, Sesbania bispinosa and Tephrosia purpurea collected from two different areas Chhatargarh area (Bikaner district and Ratangarh area (Churu district were analysed for mineral contents. The maximum Calcium (3.86%, Phosphorus (0.48%, Potassium (0.92% and Sodium (1.08% contents were found in roots and shoots of Grewia tenax collected from study area.

  17. Naturalisation, Desert, and the Symbolic Meaning of Citizenship

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2012-01-01

    of naturalisation requirements as involving notions of desert and asks what these developments imply about the meaning of citizenship. Naturalisation marks the boundary of society understood as a political community, i.e. a civic rather than territorial boundary. How this boundary is policed and on the basis......The chapter considers recent trends in naturalisation legislation in Europe and what they might imply for the symbolic meaning of citizenship. During the first decade of the 21st century many European states have strengthened requirements for access to citizenship. This development has both had...

  18. Cryptoendolithic lichen and cyanobacterial communities of the Ross Desert, Antarctica

    Science.gov (United States)

    Friedmann, E. I.; Hua, M.; Ocampo-Friedmann, R.

    1988-01-01

    Cryptoendolithic microbial communities in the Ross Desert (McMurdo Dry Valleys) are characterized on the basis of photosynthetic microorganisms and fungi. Two eukaryotic communities (the lichen-dominated and Hemichloris communities) and three cyanobacterial communities (the red Gloeocapsa, Hormathonema-Gloeocapsa, and Chroococcidiopsis communities) are described. Eleven coccoid, one pleurocapsoid, and five filamentous cyanobacteria occurring in these communities are characterized and illustrated. The moisture grade of the rock substrate seems to affect pH, formation of primary iron stain, and the distribution of microbial communities.

  19. The desert as territorial representation of Mexico’s North

    Directory of Open Access Journals (Sweden)

    Enrique Rajchenberg

    2012-08-01

    Full Text Available The northern region of Mexico presented a challenge for colonization since colonial times, both because of its physical features and for its indiegenous inhabitants. Is because of the former that the representations crafted in the central part of the country about the North always referred it as a dangerous, fearsome desert. For the US inhabitants, who wanted that same territory since the beginning of the XIX century, its inhabitants were the personified racial degeneration. This article analyses this two-sided architecture of the territorial representations with which the North of Mexico was symbolized during the XIX century, and that is still reproduced nowadays.

  20. Robot Science Autonomy in the Atacama Desert and Beyond

    Science.gov (United States)

    Thompson, David R.; Wettergreen, David S.

    2013-01-01

    Science-guided autonomy augments rovers with reasoning to make observations and take actions related to the objectives of scientific exploration. When rovers can directly interpret instrument measurements then scientific goals can inform and adapt ongoing navigation decisions. These autonomous explorers will make better scientific observations and collect massive, accurate datasets. In current astrobiology studies in the Atacama Desert we are applying algorithms for science autonomy to choose effective observations and measurements. Rovers are able to decide when and where to take follow-up actions that deepen scientific understanding. These techniques apply to planetary rovers, which we can illustrate with algorithms now used by Mars rovers and by discussing future missions.

  1. Design criteria for light high speed desert air cushion vehicles

    Science.gov (United States)

    Abulnaga, B. E.

    An evaluation is made of the applicability and prospective performance of ACVs in trans-Saharan cargo transport, in view of the unique characteristics of the dry sand environment. The lightweight/high-speed ACV concept envisioned is essentially ground effect aircraftlike, with conventional wheels as a low-speed backup suspension system. A propeller is used in ground effect cruise. Attention is given to the effects on vehicle stability and performance of sandy surface irregularities of the desert topography and of cross-winds from various directions relative to vehicle movement.

  2. Desert National Wildlife Refuge Complex: Ash Meadows, Desert, Moapa Valley, and Pahranagat National Wildlife Refuges: Final Comprehensive Conservation Plan and Environmental Impact Statement

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Desert NWR Complex for the next 15 years. This plan outlines the Complex vision and...

  3. Impact of solid discharges from coal usage in the Southwest.

    Science.gov (United States)

    Jones, D G; Straughan, I R

    1978-12-01

    The Southwestern region of the United States is extremely wealthy in low sulfur coal resources which must be eventually utilized in response to national energy balance priorities. Fly ash and scrubber sludge can be safely disposed of using properly managed techniques to ensure that any potential impact from elements such as boron, molybdenum, or selenium is rendered insignificant. Alternative methods of solids utilization are presently being developed. Fly ash is presently being marketed commercially as an additive for concrete manufacture. Successful experiments have been completed to demonstrate the manufacture of commercial-grade wallboard from scrubber sludge. Also, greenhouse studies and field experiments have been conducted to demonstrate increased yields of selected crops grown on typical soils amended with fly ash in amounts ranging from 2% to 8%, by weight. These studies also indicate that barium and strontium may be good monitoring indices for determining atmospheric deposition of fly ash, due to their concentration ratios in soil and vegetation samples. Further studies are being conducted to confirm encouraging irrigation and crop-yield data obtained with fly ash amended soils. Finally, the composition of many fly ashes and soils are similar in the Southwest, and there are no anticipated solid discharges from coal usage which cannot be rendered insignificant with proper management of existing and emerging methods of treatment. Compared with the water availability impact of coal usage in the Southwest, the impact of solid waste discharges are insignificant.

  4. An Analysis of Contracting Actions by United States Based Department of Defense Organizations to Support Operations Desert Shield and Desert Storm

    Science.gov (United States)

    1992-09-01

    Personal Interviews . . . . .... 36 Use of the Delphi Method . . . . . .... 37 Discussion of Investigative Questions . . . 39 Investigative Questions...the end of Desert Storm. Prior to Desert Shield the two manufacturers of injectors for atropine, a nerve agent antidote, were producing 60,000 units...two-stage approach was the formal phase, in which the Delphi technique was determined to be appropriate (Emory and Cooper, 1991:149). The data was

  5. The United States Army Aviation Center and Fort Rucker during Operations DESERT SHIELD and DESERT STORM. Addendum to the 1991 Annual Command History

    Science.gov (United States)

    1991-01-01

    transcript of an oral briefing conducted June 17, 1991, for BG Konitzer , subj: DESERT SHIELD/DESERT STORM, Oral Interview File, Aviation Branch History...housing reserve units, Mr. Bill Lee , noted "•lhe [1st Aviation Brigade], who controlled these two units, had allowed the individuals to leave their...call went out! The DENTACs from Fort Lee , Fort Meade, Fort Jackson, Fort Gordon, Fort Benning, and the area dental laboratory at Fort Gordon soon

  6. Annual Post-Closure Inspection and Monitoring Report for Corrective Action Unit 329: Area 22 Desert Rock Airstrip Fuel Spill, Nevada Test Site, Nevada, Rev. No.: 0

    Energy Technology Data Exchange (ETDEWEB)

    Alfred Wickline

    2006-09-01

    This report presents the data collected during field activities and quarterly soil-gas sampling activities conducted from May 9, 2005, through May 20, 2006, at Corrective Action Unit (CAU) 329, Area 22 Desert Rock Airstrip (DRA) Fuel Spill; Corrective Action Site (CAS) 22-44-01, Fuel Spill. The CAU is located at the DRA, which is located approximately two miles southwest of Mercury, Nevada, as shown in Figure 1-1. Field activities were conducted in accordance with the revised sampling approach outlined in the Addendum to the Closure Report (CR) for CAU 329 (NNSA/NSO, 2005) to support data collection requirements. The previous annual monitoring program for CAU 329 was initiated in August 2000 using soil-gas samples collected from three specific intervals at the DRA-0 and DRA-3 monitoring wells. Results of four sampling events from 2000 through 2003 indicated there is uncertainty in the approach to establish a rate of natural attenuation as specified in ''Streamlined Approach for Environmental Restoration (SAFER) Work Plan for Corrective Action Unit 329: Area 22 Desert Rock Airstrip Fuel Spill, Nevada Test Site, Nevada'' (DOE/NV, 1999). As a result, the Addendum to the CR (NNSA/NSO, 2005) was completed to address this uncertainty by modifying the previous approach. A risk evaluation was added to the scope of the project to determine if the residual concentration of the hazardous constituents of JP4 pose an unacceptable risk to human health or the environment and if a corrective action was required at the site, because the current quarterly monitoring program is not expected to yield a rate constant that could be used effectively to determine a biodegradation rate for total petroleum hydrocarbons (TPH) in less than the initial five years outlined in the CR. Additionally, remediation to the Tier 1 action level for TPH is not practical or technically feasible due to the depth of contamination.

  7. Diabetes and Kidney Disease in American Indians: Potential Role of Sugar-Sweetened Beverages.

    Science.gov (United States)

    Yracheta, Joseph M; Lanaspa, Miguel A; Le, MyPhuong T; Abdelmalak, Manal F; Alfonso, Javier; Sánchez-Lozada, Laura G; Johnson, Richard J

    2015-06-01

    Since the early 20th century, a marked increase in obesity, diabetes, and chronic kidney disease has occurred in the American Indian population, especially the Pima Indians of the Southwest. Here, we review the current epidemic and attempt to identify remediable causes. A search was performed using PubMed and the search terms American Indian and obesity, American Indian and diabetes, American Indian and chronic kidney disease, and American Indian and sugar or fructose, Native American, Alaska Native, First Nations, Aboriginal, Amerind, and Amerindian for American Indian for articles linking American Indians with diabetes, obesity, chronic kidney disease, and sugar; additional references were identified in these publications traced to 1900 and articles were reviewed if they were directly discussing these topics. Multiple factors are involved in the increased risk for diabetes and kidney disease in the American Indian population, including poverty, overnutrition, poor health care, high intake of sugar, and genetic mechanisms. Genetic factors may be especially important in the Pima, as historical records suggest that this group was predisposed to obesity before exposure to Western culture and diet. Exposure to sugar-sweetened beverages may also be involved in the increased risk for chronic kidney disease. In these small populations in severe health crisis, we recommend further studies to investigate the role of excess added sugar, especially sugar-sweetened beverages, as a potentially remediable risk factor.

  8. 40 CFR 81.23 - Southwest Pennsylvania Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.23 Section 81.23 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.23 Southwest Pennsylvania Intrastate Air Quality Control Region. The Southwest Pennsylvania Intrastate Air Quality Control Region is redesignated to consist of the...

  9. 40 CFR 81.118 - Southwest Missouri Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.118 Section 81.118 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.118 Southwest Missouri Intrastate Air Quality Control Region. The Southwest Missouri Intrastate Air Quality Control Region consists of the territorial area encompassed by...

  10. 40 CFR 81.97 - Southwest Florida Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Region. 81.97 Section 81.97 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.97 Southwest Florida Intrastate Air Quality Control Region. The Southwest Florida Intrastate Air Quality Control Region consists of the territorial area encompassed by...

  11. 76 FR 15307 - Notice of Staff Attendance at Southwest Power Pool Strategic Planning Committee Meeting

    Science.gov (United States)

    2011-03-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Notice of Staff Attendance at Southwest Power Pool Strategic Planning... attend the meeting of the Southwest Power Pool, Inc. (SPP) Strategic Planning Committee (SPC), as...

  12. American Vitiligo Research Foundation

    Science.gov (United States)

    ... life can acquire vitiligo Welcome to The American Vitiligo Foundation 2017 AVRF Calendars Order your calendar with ... animal testing. Please Visit Our Donations Page American Vitiligo Research Foundation "We Walk By Faith, Not By ...

  13. Depression and African Americans

    Science.gov (United States)

    ... You are here Home » Depression And African Americans Depression And African Americans Not “Just the Blues” Clinical ... or spiritual communities. Commonly Asked Questions about Clinical Depression How do I get help for clinical depression? ...

  14. American Hospice Foundation

    Science.gov (United States)

    American Hospice Foundation Skip to content Home Caregiving Learning About Hospice Grief Grieving Children Grief at School Grief at ... for all who come after us. The American Hospice Foundation (AHF) closed its doors in June 2014. ...

  15. Obesity and Hispanic Americans

    Science.gov (United States)

    ... and Data > Minority Population Profiles > Hispanic/Latino > Obesity Obesity and Hispanic Americans Among Mexican American women, 77 ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  16. Obesity and Asian Americans

    Science.gov (United States)

    ... and Data > Minority Population Profiles > Asian American > Obesity Obesity and Asian Americans Non-Hispanic whites are 60% ... youthonline . [Accessed 05/25/2016] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  17. American Society of Echocardiography

    Science.gov (United States)

    American Society of Echocardiography Join Ase Member Portal Log In Membership Member Portal Log In Join ASE Renew Benefits Rates FASE – Fellow of the American Society of Echocardiography Member Referral Program FAQs Initiatives Advocacy ...

  18. American Urogynecologic Society

    Science.gov (United States)

    ... Patient Site » PFD Registry » Contact Us American Urogynecologic Society 1100 Wayne Avenue, Suite 670 Silver Spring, MD ... Us | Privacy Policy | HONcode Accredited © 2016 American Urogynecologic Society. All rights reserved.

  19. Asthma and Hispanic Americans

    Science.gov (United States)

    ... and Data > Minority Population Profiles > Hispanic/Latino > Asthma Asthma and Hispanic Americans In 2014, 2.1 million Hispanics reported that they currently have asthma. Puerto Rican Americans have almost twice the asthma ...

  20. A Comparative Analysis of the Microfabrics of Surface Horizons and Desert Varnish in Extremely Arid Soils of the Mojave (USA) and Trans-Altai Gobi (Mongolia) Deserts

    Science.gov (United States)

    Lebedeva, M. P.; Shishkov, V. A.

    2016-02-01

    The mineralogical composition of coarse fraction and characteristic features of the micro- and submicrofabrics and chemical composition of desert varnish on gravels of desert pavements and the underlying vesicular crust soil horizons were studied in the extremely arid soils of the Mojave (USA) and Trans-Altai Gobi (Mongolia) deserts. A set of common diagnostic features of elementary pedogenetic processes was identified in the automorphic desert soils developed on ancient (70-90 ka) piedmont plains composed of alluvial deposits with the high content of red-earth clay. The results of this study attest to the long and complicated history of the extremely arid soils with alternation of the humid and arid phases of pedogenesis reflected in a specific combination of textural (clay-illuvial) and carbonate pedofeatures and in the distribution patterns of iron, manganese, titanium, and barium in different layers of the desert varnish. The chemical composition of the latter did not depend on the mineralogical composition of the underlying substrates and was formed with active participation of soil microorganisms. This allowed us to conclude about the polygenetic (accretionary-microbiological) nature of desert varnish.

  1. U.S. Border Patrol Fiscal Year Statistics Southwest border sector deaths - FY 1998 through FY 2013

    Data.gov (United States)

    Department of Homeland Security — Southwest Border Sectors include: Del Rio, El Centro, El Paso, Laredo, Rio Grande Valley, San Diego, Tucson, Yuma Southwest Border Deaths By Fiscal Year (Oct. 1st...

  2. Heart Disease and African Americans

    Science.gov (United States)

    ... Minority Population Profiles > Black/African American > Heart Disease Heart Disease and African Americans Although African American adults are ... were 30 percent more likely to die from heart disease than non-Hispanic whites. African American women are ...

  3. Seed mucilage improves seedling emergence of a sand desert shrub.

    Directory of Open Access Journals (Sweden)

    Xuejun Yang

    Full Text Available The success of seedling establishment of desert plants is determined by seedling emergence response to an unpredictable precipitation regime. Sand burial is a crucial and frequent environmental stress that impacts seedling establishment on sand dunes. However, little is known about the ecological role of seed mucilage in seedling emergence in arid sandy environments. We hypothesized that seed mucilage enhances seedling emergence in a low precipitation regime and under conditions of sand burial. In a greenhouse experiment, two types of Artemisia sphaerocephala achenes (intact and demucilaged were exposed to different combinations of burial depth (0, 5, 10, 20, 40 and 60 mm and irrigation regimes (low, medium and high, which simulated the precipitation amount and frequency in May, June and July in the natural habitat, respectively. Seedling emergence increased with increasing irrigation. It was highest at 5 mm sand burial depth and ceased at burial depths greater than 20 mm in all irrigation regimes. Mucilage significantly enhanced seedling emergence at 0, 5 and 10 mm burial depths in low irrigation, at 0 and 5 mm burial depths in medium irrigation and at 0 and 10 mm burial depths in high irrigation. Seed mucilage also reduced seedling mortality at the shallow sand burial depths. Moreover, mucilage significantly affected seedling emergence time and quiescence and dormancy percentages. Our findings suggest that seed mucilage plays an ecologically important role in successful seedling establishment of A. sphaerocephala by improving seedling emergence and reducing seedling mortality in stressful habitats of the sandy desert environment.

  4. Prevalence of Mycoplasma ovipneumoniae in desert bighorn sheep in Arizona

    Science.gov (United States)

    Justice-Allen, Anne E.; Luedtke, Clint J.; Overstreet, Matthew; Cain, James W.; Stephenson, Thomas R.

    2011-01-01

    To assess the potential for an epizootic of pneumonia to result from either natural immigration or translocation, we compared the seroprevalence to Mycoplasma ovipneumoniae in several populations of desert bighorn sheep in Arizona. We collected blood samples and nasal or oropharyngeal swabs from 124 desert bighorn sheep (Ovis canadensis nelsoni) from 6 populations in Arizona in 2009 and 2010. M. ovipneumoniae organisms were detected by PCR in 22%, whereas antibodies to M. ovipneumoniae were detected in 47% of tested bighorn sheep. Mycoplasma antibodies were not found in 2 of 6 populations, indicating some bighorn sheep populations in Arizona are naïve to this bacterium. In contrast, others had seroprevalence rates up to 80%. We were able to compare seroprevalence rates and titers over time in 9 individuals (7 individuals included in the 124 bighorn sheep sampled in 2009 and 2010, and 2 individuals originally captured in 2006). Antibody titers persisted for 12 months in individuals from the Kofa National Wildlife Refuge (n = 7) while antibody titers appeared to decline in the Kanab Creek population (n = 2). M. ovipneumoniae is present or has been present in several, but not all, populations of bighorn sheep in Arizona. The results demonstrate the importance of routine health testing for future translocation efforts to reduce disease risk for naive populations.

  5. When dunes move together, structure of deserts emerges

    CERN Document Server

    Génois, Mathieu; Pont, Sylvain Courrech du; Grégoire, Guillaume

    2012-01-01

    Crescent shaped barchan dunes are highly mobile dunes that are usually presented as a prototypical model of sand dunes. Although they have been theoretically shown to be unstable when considered separately, it is well known that they form large assemblies in desert. Collisions of dunes have been proposed as a mechanism to redistribute sand between dunes and prevent the formation of heavily large dunes, resulting in a stabilizing effect in the context of a dense barchan field. Yet, no models are able to explain the spatial structures of dunes observed in deserts. Here, we use an agent-based model with elementary rules of sand redistribution during collisions to access the full dynamics of very large barchan dune fields. Consequently, stationnary, out of equilibrium states emerge. Trigging the dune field density by a sand load/lost ratio, we show that large dune fields exhibit two assymtotic regimes: a dilute regime, where sand dune nucleation is needed to maintain a dune field, and a dense regime, where dune c...

  6. Biological Soil Crusts: Webs of Life in the Desert

    Science.gov (United States)

    Belnap, Jayne

    2001-01-01

    Although the soil surface may look like dirt to you, it is full of living organisms that are a vital part of desert ecosystems. This veneer of life is called a biological soil crust. These crusts are found throughout the world, from hot deserts to polar regions. Crusts generally cover all soil spaces not occupied by green plants. In many areas, they comprise over 70% of the living ground cover and are key in reducing erosion, increasing water retention, and increasing soil fertility. In most dry regions, these crusts are dominated by cyanobacteria (previously called blue-green algae), which are one of the oldest known life forms. Communities of soil crusts also include lichens, mosses, microfungi, bacteria, and green algae. These living organisms and their by-products create a continuous crust on the soil surface. The general color, surface appearance, and amount of coverage of these crusts vary depending on climate and disturbance patterns. Immature crusts are generally flat and the color of the soil, which makes them difficult to distinguish from bare ground. Mature crusts, in contrast, are usually bumpy and dark-colored due to the presence of lichens, mosses, and high densities of cyanobacteria and other organisms.

  7. Feedbacks between woody plant encroachment and microclimate in desert grasslands

    Science.gov (United States)

    D'Odorico, P.; He, Y.; De Wekker, S.; Fuentes, J. D.; Collins, S. L.; Pockman, W.

    2011-12-01

    The encroachment of woody plants into grasslands is a global phenomenon that results from a variety of drivers related to land use and global environmental change. In the southwestern U.S., shrub encroachment can be associated with land degradation, soil erosion, and the formation of coppice dunes. In this region, the relatively abrupt character of grassland-to-shrubland transitions - both in time and in space - suggests that arid and semiarid rangelands may exhibit two alternative stable states characterized by either grass or shrub dominance. In these bistable landscapes, even small changes in environmental drivers may cause abrupt state transitions from grassland to shrubland, sustained by positive feedbacks with environmental drivers. We show that positive feedbacks between land cover change and microclimate may contribute to shrub encroachment in the southwestern US. Thus, we investigate changes in surface air temperature and energy balance resulting from grass-to-shrub transitions in the northern Chiuhuahuan desert. We find that the encroachment of native shrubs into desert grasslands modifies the surface energy balance with the overall net effect of increasing nighttime air temperatures, thereby favoring the establishment and growth of freeze-sensitive Larrea plants.

  8. Orbital radar studies of paleodrainages in the central Namib Desert

    Science.gov (United States)

    Lancaster, N.; Schaber, G.G.; Teller, J.T.

    2000-01-01

    Orbital radar images of the central Namib Desert show clearly the extent of relict fluvial deposits associated with former courses of the Tsondab and Kuiseb rivers. South of the Kuiseb River, radar data show the existence of a drainage network developed in calcrete-cemented late Tertiary fluvial deposits. The sand-filled paleovalleys are imaged as radar-dark tones in contrast to the radar-bright interfluves where the calcreted gravels occur. The drainage network developed as a result of local runoff from indurated gravels and channeled surface and subsurface flow to the sites of the many interdune lacustrine deposits found in the area. (C) Elsevier Science Inc., 2000.Orbital radar images of the central Namib Desert show clearly the extent of relict fluvial deposits associated with former courses of the Tsondab and Kuiseb rivers. South of the Kuiseb River, radar data show the existence of a drainage network developed in calcrete-cemented late Tertiary fluvial deposits. The sand-filled paleovalleys are imaged as radar-dark tones in contrast to the radar-bright interfluves where the calcreted gravels occur. The drainage network developed as a result of local runoff from indurated gravels and channeled surface and subsurface flow to the sites of the many interdune lacustrine deposits found in the area.

  9. Does translocation influence physiological stress in the desert tortoise?

    Science.gov (United States)

    Drake, K.K.; Nussear, K.E.; Esque, T.C.; Barber, A.M.; Vittum, K.M.; Medica, P.A.; Tracy, C.R.; Hunter, K.W.

    2012-01-01

    Wildlife translocation is increasingly used to mitigate disturbances to animals or habitat due to human activities, yet little is known about the extent to which translocating animals causes stress. To understand the relationship between physiological stress and translocation, we conducted a multiyear study (2007–2009) using a population of desert tortoises (Gopherus agassizii) near Fort Irwin, California. Blood samples were collected from adult tortoises in three treatment groups (resident, translocated and control) for 1 year prior to and 2 years after translocation. Samples were analyzed by radioimmunoassay for plasma total corticosterone (CORT), a glucocorticoid hormone commonly associated with stress responses in reptiles. CORT values were analyzed in relation to potential covariates (animal sex, date, behavior, treatment, handling time, air temperature, home-range size, precipitation and annual plant production) among seasons and years. CORT values in males were higher than in females, and values for both varied monthly throughout the activity season and among years. Year and sex were strong predictors of CORT, and translocation explained little in terms of CORT. Based on these results, we conclude that translocation does not elicit a physiological stress response in desert tortoises.

  10. Prospects and constraints of desert agriculture: lessons from West Omdurman.

    Science.gov (United States)

    El Gamri, Tarig

    2004-12-01

    Sudan is the largest country in Africa with an area of about 2.5 million km2; the country hosts a population of about 31 million people. About two-thirds of the country area is located within arid and semi-arid regions. Recently, especially during the last half of the previous century, these regions were subject to various forms of land degradation. This paper discusses the general prospects and constraints of desert agriculture. It also presents a detailed case study of West Omdurman, which is located in a semi-desert climatic zone. The ambitious plans to utilise the area for agricultural production were initiated because of the relatively fertile soil, availability of water and the proximity of the area to marketing and export centres. The paper discusses the different land use systems experienced in the area, reasons for failure are identified and possible remedies discussed. In addition, constraints facing the proposed West Omdurman Canal Project are also discussed. Finally, the paper reviews the major research findings of Rawakeeb Dryland Research Center with regard to promoting agricultural productivity.

  11. Effect of desertification on productivity in a desert steppe

    Science.gov (United States)

    Tang, Zhuangsheng; An, Hui; Deng, Lei; Wang, Yingying; Zhu, Guangyu; Shangguan, Zhouping

    2016-06-01

    Desertification, one of the most severe types of land degradation in the world, is of great importance because it is occurring, to some degree, on approximately 40% of the global land area and is affecting more than 1 billion people. In this study, we used a space-for-time method to quantify the impact of five different desertification regimes (potential (PD), light (LD), moderate (MD), severe (SD), and very severe (VSD)) on a desert steppe ecosystem in northern China to examine the relationship between the productivity of the vegetation and soil properties and to determine the mechanism underlying the effects of desertification on productivity. Our results showed that the effects of desertification on TP (total phosphorus) and AP (available phosphorus) were not significant, and desertification decreased productivity in the desert steppe as a result of direct changes to soil physical properties, which can directly affect soil chemical properties. Therefore, intensive grassland management to improve soil quality may result in the long-term preservation of ecosystem functions and services.

  12. Microenvironments and microscale productivity of cyanobacterial desert crusts

    Science.gov (United States)

    Garcia-Pichel, F.; Belnap, Jayne

    1996-01-01

    We used microsensors to characterize physicochemical microenvironments and photosynthesis occurring immediately after water saturation in two desert soil crusts from southeastern Utah, which were formed by the cyanobacteria Microcoleus vaginatus Gomont, Nostoc spp., and Scytonema sp. The light fields within the crusts presented steep vertical gradients in magnitude and spectral composition. Near-surface light-trapping zones were formed due to the scattering nature of the sand particles, but strong light attenuation resulted in euphotic zones only ca. 1 mm deep, which were progressively enriched in longer wavelengths with depth. Rates of gross photosynthesis (3.4a??9.4 mmol O2A?ma??2A?ha??1) and dark respiration (0.81a??3.1 mmol Oa??2A?ma??2A?ha??1) occurring within 1 to several mm from the surface were high enough to drive the formation of marked oxygen microenvironments that ranged from oxygen supersaturation to anoxia. The photosynthetic activity also resulted in localized pH values in excess of 10, 2a??3 units above the soil pH. Differences in metabolic parameters and community structure between two types of crusts were consistent with a successional pattern, which could be partially explained on the basis of the microenvironments. We discuss the significance of high metabolic rates and the formation of microenvironments for the ecology of desert crusts, as well as the advantages and limitations of microsensor-based methods for crust investigation.

  13. Nitrogen Deposition and Leaching from Two Forested Catchments in Southwest China — Preliminary Data and Research Needs

    Directory of Open Access Journals (Sweden)

    T. Larssen

    2001-01-01

    Full Text Available Increased nitrogen deposition has resulted in increased nitrogen pools and nitrogen leaching in European and North American forest soils. The development in Asia in general, and China in particular, suggests increased deposition of reduced nitrogen from changes in agricultural practices and of oxidized nitrogen from rapid growth of the transportation sector. Decreased nitrogen retention in forested areas in the future may cause increased NO3– leaching and, thus, acidification and eutrophication in surface waters. The differences in climate, ecosystems, land use, and deposition history make direct application of knowledge from studies in Europe and North America difficult. In Southwest China the potential for nitrogen mobilization from forest soils may be high because of the warm and humid climate, resulting in high decomposition rates of soil organic matter. However, there are very few data available for quantifying the suspected potential for increased nitrogen leaching in forest ecosystems. Here we present data from two forested catchments, dominated by Masson pine (Pinus massoniana, near Guiyang and Chongqing, respectively, in Southwest China. The present nitrogen deposition is moderate, estimated in the range from 10 to 40 kg N ha–1 year–1. The C/N ratios of the soils are generally below 15. Nitrate concentrations in soil water are rather variable in space, with highest values of several hundred microequivalents per liter. The turnover rate of nitrogen in the forest ecosystem is quite high compared to the atmospheric deposition rate. At present, nitrate runoff from the catchments is low and intermediate in Guiyang and Chongqing, respectively. More research is needed to improve our ability to predict future nitrogen leaching from subtropical Asian coniferous forests.

  14. Vertical distribution of the free-living amoeba population in soil under desert shrubs in the Negev desert, Israel.

    Science.gov (United States)

    Rodriguez-Zaragoza, Salvador; Mayzlish, Einav; Steinberger, Yosef

    2005-04-01

    A field study was designed to examine the effect of desert shrubs on the dynamics of free-living amoebae in arid soil. Soil samples from 0- to 50-cm depths were collected at 10-cm intervals in each of the four seasons. The vertical distributions of the four main morphological types of amoebae, grouped according to their mobility, and of small flagellate populations were measured under the canopies of Hammada scoparia and Atriplex halimus, shrubs belonging to the chloride-absorbing xerohalophytes. The result obtained from the field study demonstrated that the total number of protozoa was significantly higher during the wet seasons (winter and spring) than during the dry seasons. The protozoan population was more diverse under the canopy of H. scoparia during the wet seasons, reaching 8,000 individuals per 1 g of dry soil, whereas during the dry seasons, the populations were higher under the canopy of A. halimus, with a mean of 250 individuals. The protozoan population in the deeper layers (40 to 50 cm) was found to be as active as that in the upper layers, demonstrating that, in the desert, soil columns below 20 cm are fertile and worth studying. The type 1 amoebae (e.g., Acanthamoeba and Filamoeba spp.) were the most abundant throughout the study period, and their numbers were significantly higher than those of the other amoeba types.

  15. Fate and transport of pesticides in the ground water systems of southwest Georgia, 1993-2005

    Science.gov (United States)

    Dalton, M.S.; Frick, E.A.

    2008-01-01

    Modern agricultural practices in the United States have resulted in nearly unrivaled efficiency and productivity. Unfortunately, there is also the potential for release of these compounds to the environment and consequent adverse affects on wildlife and human populations. Since 1993, the National Water-Quality Assessment (NAWQA) program of the U.S. Geological Survey has evaluated water quality in agricultural areas to address these concerns. The objective of this study is to evaluate trends in pesticide concentrations from 1993-2005 in the surficial and Upper Floridan aquifers of southwest Georgia using pesticide and pesticide degradate data collected for the NAWQA program. There were six compounds - five herbicides and one degradate - that were detected in more than 20% of samples: atrazine, deethylatrazine (DEA), metolachlor, alachlor, floumeturon, and tebuthiuron. Of the 128 wells sampled during the study, only eight wells had pesticide concentrations that either increased (7) or decreased (1) on a decadal time scale. Most of the significant trends were increasing concentrations of pesticides in older water; median pesticide concentrations did not differ between the surficial and Upper Floridan aquifers from 1993 and 2005. Deethylatrazine, in the Upper Floridan aquifer, was the only compound that had a significant change (increase) in concentration during the study. The limited number of wells with increases in pesticide concentrations suggest that ground-water sources of these compounds are not increasing in concentration over the time scale represented in this study. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  16. Light-induced bird strikes on vessels in Southwest Greenland

    DEFF Research Database (Denmark)

    Merkel, Flemming Ravn; Johansen, Kasper Lambert

    2011-01-01

    Light-induced bird strikes are known to occur when vessels navigate during darkness in icy waters using powerful searchlight. In Southwest Greenland, which is important internationally for wintering seabirds, we collected reports of incidents of bird strikes over 2–3 winters (2006–2009) from navy...... vessels, cargo vessels and trawlers (total n = 19). Forty-one incidents were reported: mainly close to land (birds were reported killed in a single incident. All occurred between 5 p.m. and 6 a.m. and significantly more birds were involved when...... visibility was poor (snow) rather than moderate or good. Among five seabird species reported, the common eider (Somateria mollissima) accounted for 95% of the bird casualties. Based on spatial analyses of data on vessel traffic intensity and common eider density we are able to predict areas with high risk...

  17. Gravity and magnetic study of Yucca Wash, southwest Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Langenheim, V.E.; Ponce, D.A.; Oliver, H.W.; Sikora, R.F. [Geological Survey, Menlo Park, CA (United States)

    1993-12-31

    Gravity and ground magnetic data were collected along five traverses across and one traverse along Yucca Wash in the southwest quadrant of the Nevada Test Site. Two additional ground magnetic profiles were collected approximately 100 m to either side of the longitudinal profile. These data do not indicate major vertical offsets greater than 100 m using a density contrast of 0.2 to 0.3 g/cm{sup 3} along the proposed Yucca Wash fault. A broad magnetic high coincides with the location of the hydrologic gradient. Density profiling, a technique used to determine the average density of small topographic features, suggests that the density of near-surface material in the vicinity of Yucca Wash is about 2.0 g/cm{sup 3}.

  18. The Network for Astronomy in Education in Southwest New Mexico

    Science.gov (United States)

    Neely, B.

    1998-12-01

    The Network for Astronomy in Education was organized to use astronomy as a motivational tool to teach science methods and principles in the public schools. NFO is a small private research observatory, associated with the local University, Western New Mexico. We started our program in 1996 with an IDEA grant by introducing local teachers to the Internet, funding a portable planetarium (Starlab) for the students, and upgrading our local radio linked computer network. Grant County is a rural mining and ranching county in Southwest New Mexico. It is ethnically diverse and has a large portion of the population below the poverty line. It's dryness and 6000' foot elevation, along with dark skies, suite it to the appreciation of astronomy. We now have 8 local schools involved in astronomy at some level. Our main programs are the Starlab and Project Astro, and we will soon install a Sidewalk Solar System in the center of Silver City.

  19. Bottom currents and shelf sediments, southwest of Britain

    Science.gov (United States)

    Hamilton, D.; Sommerville, J. H.; Stanford, P. N.

    1980-04-01

    The shelf sediments southwest of Britain range from large boulders to muddy fine sands. The large boulders, which occur in patches, were probably dropped from icebergs. A reworked basal bed forms an extensive pavement over which well to very well sorted medium to fine sands are transported, whilst muddy sediments occur between sandbanks. Measurements of boundary layer currents show that the threshold friction velocities for the sands are exceeded by maximum tidal flows over most of the area. Repeated selective entrainment by tidal currents, in a virtually closed sediment system, is proposed as the mechanism for the formation of these very well sorted mobile sands, which have a mean size close to that of the most easily entrained grains and size frequency distributions approaching log-normality.

  20. Wolf predation in the Burwash caribou herd, southwest Yukon

    Directory of Open Access Journals (Sweden)

    David A. Gauthier

    1986-06-01

    Full Text Available The role of wolf predation as a proximate mortality factor influencing caribou herd growth was assessed in the Burwash herd (400 animals in the southwest Yukon between 1980 - 1982. Ten to 14 wolves in two packs preyed primarily on caribou (Rangifer tarandus caribou and moose (Alces alces with disproportionate consumption of caribou (relative to available biomass in the rut and winter periods. Wolf predation was responsible for 72% of total annual mortality in 1980 - 1981 and 46% in 1981 - 1982. Losses due to human harvest varied between 7 to 13%. Additional limited data on climatic factors and winter forage indicated forage-climate were not major proximate mortality factors in 1980 - 1981, but that early-calving climate may have been a factor in increased calf mortality in 1982.

  1. Dung of Mammuthus in the arid Southwest, North America

    Science.gov (United States)

    mead, Jim I.; Agenbroad, Larry D.; Davis, Owen K.; Martin, Paul S.

    1986-01-01

    The discovery of a unique organic deposit in a dry cave on the Colorado Plateau, southern Utah, permits the first comparison of the physical characteristics and the diet of the dung of the extinct mammoths from the arid Southwest, North America, with that of mammoths from Siberia and northern China, the only other known locations of such remains. The deposit buried beneath sand and rockfall is composed primarily of mammoth dung, estimated at over 300 m 3. Radiocarbon dates on dung boluses indicate that the mammoths frequented the cave between approximately 14,700 and 11,000 yr B.P. (the range of ages at 2σ). The desiccated boluses, measuring approximately 230 × 170 × 85 mm, are nearly identical in size to dung from extant elephants. The largest contents in the dung are stalks measuring 60 × 4.5 mm. Grasses and sedges dominated the diet, although woody species were commonly eaten.

  2. Data report for the Southwest Residential Experiment Station, February 1982

    Science.gov (United States)

    Lieberman, M.; Hai, O. Y.; Hocking, G.; Whitaker, C.

    1982-04-01

    Tabulated are physical performance data obtained from the photovoltaic energy systems under test at the Southwest Residential Experiment Station (SW RES) in Las Cruces, New Mexico for the month of February 1982. A one-page data summary is included as well as a more detailed hourly tabulation for an average day of the month. Energy histograms are provided for each prototype system. The histograms also present horizontal and plane-of-array insolation data as well as comments that explain data and/or energy production anomalies. Eight prototype residential PV systems are under test, each consisting of a roof-mounted PV array sized to meet at least 50% of the annual electric demand of an energy-conserving house, and an enclosed structure to house the remainder of the PV system equipment, test instrumentation, and work space. All systems are grid-connected.

  3. Turtle riders: remoras on marine turtles in Southwest Atlantic

    Directory of Open Access Journals (Sweden)

    Ivan Sazima

    Full Text Available An overview is presented for a poorly documented relationship between reef vertebrates in Southwest Atlantic: remoras (Echeneidae associated with marine turtles. Two remora species (Echeneis naucrates and Remora remora and four turtle species (Caretta caretta, Chelonia mydas, Eretmochelys imbricata, and Dermochelys coriacea are here recorded in symbiotic associations in the SW Atlantic. Echeneis naucrates was recorded both on the coast and on oceanic islands, whereas R. remora was recorded only at oceanic islands and in the open sea. The remora-turtle association is usually regarded as an instance of phoresis (hitchhiking, albeit feeding by the fish is also involved in this symbiosis type. This association seems to be rare in SW Atlantic.

  4. Chemical constituents of Cenchrus ciliaris L. from the Cholistan desert, Pakistan

    Directory of Open Access Journals (Sweden)

    Ashraf Muhammad Aqeel

    2013-01-01

    Full Text Available The Cholistan Desert is an extension of the Great Indian Desert, covering an area of 26,330 km2. The desert can be divided into two main geomorphic regions: the northern region, known as Lesser Cholistan, constituting the desert margin and consisting of a series of saline alluvial flats alternating with low sand ridges/dunes; and the southern region, known as Greater Cholistan, a wind-resorted sandy desert comprised of a number of old Hakra River terraces with various forms of sand ridges and inter-ridge valleys. Cholistan Desert presents a complex pattern of alluvial and aeolian depositions. In the present study we evaluated the nutritive value of different accessions of the perennial range grass Cenchrus ciliaris collected from the Cholistan Desert, Pakistan. Standard method, Benedict’s quantitative reagent for carbohydrates, crude protein and nitrogen by the Kjeldahl method, mineral analysis by flame photometer and estimation of crude fiber by using acid base treatment, were utilized. The results suggest that Cenchrus ciliaris has medicinal and nutritional importance, and that it could be a good source of important nutrients for humans, helping to alleviate poverty in poor local communities.

  5. Impact of long-range desert dust transport on hydrometeor formation over coastal East Asia

    Science.gov (United States)

    Zhang, Zhenxi; Zhou, Wen; Wenig, Mark; Yang, Liangui

    2017-01-01

    Model simulations and hydrological reanalysis data for 2007 are applied to investigate the impact of long-range desert dust transport on hydrometeor formation over coastal East Asia. Results are analyzed from Hong Kong and Shanghai, which are two representative coastal cities of East Asia. Long-range desert dust transport impacts mainly spring and summer clouds and precipitation over coastal East Asia. In spring, clouds and precipitation come mainly from large-scale condensation and are impacted mainly by dust from the Gobi, Sahara, and Thar deserts. These desert dusts can participate in the precipitation within and below the clouds. At lower latitudes, the dust particles act mainly as water nuclei. At higher latitudes, they act as both water nuclei and ice nuclei. The effect of Gobi, Sahara, and Thar dust on large-scale clouds and precipitation becomes stronger at higher latitudes. In summer, clouds and precipitation over coastal East Asia come mainly from convection and are impacted mainly by dust from the Taklamakan, Arabian, and Karakum-Kavir deserts. Most Taklamakan dust particles can participate in precipitation within convective clouds as ice nuclei, while Arabian and Karakum-Kavir dust particles participate only as water nuclei in precipitation below the clouds. The effect of Taklamakan dust on convective clouds and precipitation becomes stronger at lower latitudes. Of all the desert dusts, that from the Gobi and Taklamakan deserts has the relatively largest impact. Gobi dust impacts climate change in coastal East Asia by affecting spring water clouds at higher latitudes.

  6. Marine mammal strandings in the New Caledonia region, Southwest Pacific.

    Science.gov (United States)

    Borsa, Philippe

    2006-04-01

    Four hundred twenty three marine mammals, in 72 stranding events, were recorded between 1877 and 2005 in New Caledonia, the Loyalty Islands, and Vanuatu in the southwest Pacific. Sixteen species were represented in this count, including: minke whale, Balaenoptera acutorostrata (1 single stranding), sei whale, B. borealis (1 single stranding), blue whale, B. musculus (1 single stranding), humpback whale, Megaptera novaeangliae (2 single strandings), giant sperm whale, Physeter macrocephalus (18 single strandings, 2 pair strandings), pygmy sperm whale, Kogia breviceps (5 single strandings), dwarf sperm whale, K. sima (2 single strandings, 1 triple stranding), Blainville's beaked whale, Mesoplodon densirostris (2 single strandings), short-finned pilot whale, Globicephala macrorhynchus (4 strandings, 56 individuals), melon-headed whale, Peponocephala electra (1 single stranding and 2 mass strandings totalling 231 individuals), common dolphin, Delphinus delphis (1 single stranding), spinner dolphin, Stenella longirostris (1 pair stranding and 2 mass strandings of groups of approximately 30 individuals each), Indian Ocean bottlenose dolphin, Tursiops aduncus (2 single strandings), dugong, Dugong dugon (14 single strandings), and New Zealand fur seal, Arctocephalus forsteri (3 single strandings). A stranded rorqual identified as an Antarctic minke whale (B. bonaerensis), with coloration patterns that did not match known descriptions, was also reported. Sei whale was recorded for the first time in the tropical Southwest Pacific region and Antarctic minke whale, melon-headed whale, and Indian Ocean bottlenose dolphin were recorded for the first time in New Caledonia. Strandings of sperm whales were most frequent in the spring, but also occurred in autumn months, suggesting a seasonal pattern of occurrence possibly related to seasonal migration. One stranded humpback whale bore the scars of a killer whale's attack and one dugong was injured by a shark. Scars left by

  7. Stable Isotopic Variations in Precipitation in Southwest China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This study analyzes the relationships of stable isotopes in precipitation with temperature, air pressure and humidity at different altitudes, and the potential influencing mechanisms of control factors on the stable isotopes in precipitation in Southwest China. There appear marked negative correlations of the δ18O in precipitation with precipitation amount, vapor pressure and atmospheric precipitable water (PW)at the Mengzi, Simao and Tengchong stations on the synoptic timescale; the marked negative correlations between the δ18O in precipitation and the diurnal mean temperature at 400 hPa, 500 hPa, 700 hPa and 850hPa are different from the temperature effect in middle-high-latitude inland areas. In addition, the notable positive correlation between the δ18O in precipitation and the dew-point deficit △Td at different altitudes is found at the three stations. Precipitation is not the only factor generating an amount effect. Probably,the amount effect is related to the variations of atmospheric circulation and vapor origins. On the annual timescale, the annual precipitation amount weighted-mean δ18O displays negative correlations not only with annual precipitation but also with annual mean temperature at 500 hPa. It can be deduced that, in the years with an abnormally strong summer monsoon, more warm and wet air from low-latitude oceans is transported northward along the vapor channel located in Southwest China and generates abnormally strong rainfall on the way. Meanwhile, the abnormally strong condensation process will release more condensed latent heat in the atmosphere, and this will lead to a rise of atmospheric temperature during rainfall but a decline of δ18O in the precipitation. On the other hand, in the years with an abnormally weak summer monsoon, the precipitation and the atmospheric temperature during rainfalls decrease abnormally but the δ18O in precipitation increases.

  8. Temporal variation of the water budget in Central Southwest Asia

    Science.gov (United States)

    Malik, K.; Taylor, P. A.; Szeto, K.

    2009-05-01

    Water budget terms for Central Southwest Asia (CSWA) have been computed using National Centre for Environmental Prediction (NCEP) reanalysis data for 60-years from 1948-2007 and European Centre for Medium-Range Weather Forecasts (ERA-40) reanalysis for the 44-year period from 1958-2001. First, observational rainfall data from the Pakistan Meteorological Department (PMD) and the Iran Meteorological Organization (IMO) were compared with Global Prediction Climate Centre (GPCC) version-4 data. GPCC rainfall data appear close to the observational data of the region. GPCC rainfall data have then been used for comparison with both NCEP and ERA-40 reanalysis data sets and it was found that NCEP is closer to GPCC than ERA-40 for this region. The domain under study is located from 45-75E and 25-40N including parts of Iran, Afghanistan, Pakistan, Iraq and Kazakhstan. For realistic results only land areas has been used in the study. In the ERA-40 reanalysis data, evapotranspiration may have been overestimated in the system noting that evaporation exceeds rainfall. NCEP computes more precipitation than evaporation with moisture flux into the area providing the balance. This suggests that the ERA-40 data set is not suitable for computing water budget terms in this particular region. Moisture flux convergence is computed by using four daily readings (00, 06, 12 and 18z) up to 300 hPa. Finally, Principle Component Analysis (PCA) techniques are used to divide the domain into six areas and we discuss the temporal variation of rainfall for each area. The main contribution of rainfall in most of the areas is due to western disturbance weather systems moving from west to east. Also the area at the extreme southeast is getting rain though southwest monsoon in the month of July August. It is observed that rainfall decreases significantly after 1980 as a result of a dedcrease in moisture flux convergence.

  9. Identification of debris-flow hazards in warm deserts through analyzing past occurrences: Case study in South Mountain, Sonoran Desert, USA

    Science.gov (United States)

    Dorn, Ronald I.

    2016-11-01

    After recognition that debris flows co-occur with human activities, the next step in a hazards analysis involves estimating debris-flow probability. Prior research published in this journal in 2010 used varnish microlamination (VML) dating to determine a minimum occurrence of 5 flows per century over the last 8100 years in a small mountain range of South Mountain adjacent to neighborhoods of Phoenix, Arizona. This analysis led to the conclusion that debris flows originating in small mountain ranges in arid regions like the Sonoran Desert could pose a hazard. Two major precipitation events in the summer of 2014 generated 35 debris flows in the same study area of South Mountain-providing support for the importance of probability analysis as a key step in a hazards analysis in warm desert settings. Two distinct mechanisms generated the 2014 debris flows: intense precipitation on steep slopes in the first storm; and a firehose effect whereby runoff from the second storm was funneled rapidly by cleaned-out debris-flow chutes to remobilize Pleistocene debris-flow deposits. When compared to a global database on debris flows, the 2014 storms were among the most intense to generate desert debris flows - indicating that storms of lesser intensity are capable of generating debris flows in warm desert settings. The 87Sr/86Sr analyses of fines and clasts in South Mountain debris flows of different ages reveal that desert dust supplies the fines. Thus, wetter climatic periods of intense rock decay are not needed to resupply desert slopes with fines; instead, a combination of dust deposition supplying fines and dirt cracking generating coarse clasts can re-arm chutes in a warm desert setting with abundant dust.

  10. Composition, origin and weathering process of surface sediment in Kumtagh Desert, Northwest China

    Institute of Scientific and Technical Information of China (English)

    XU Zhiwei; LU Huayu; ZHAO Cunfa; WANG Xianyan; SU Zhizhua; WANG Zhenting; LIU Hongyi; WANG Lixin; LU Qi

    2011-01-01

    Kumtagh Desert is one of the eight biggest deserts in China,but poorly investigated before our interdisciplinary study because of the difficulty of access.In this paper,33 representative surface sediment samples were collected from the Kumtagh Desert and analyzed in the laboratory to obtain heavy mineral components and geochemical element contents.Results show that various kinds of heavy minerals are present in these samples,with high levels of epidote and hornblende.Si and AI take up a large part of chemical composition.Compared with the average composition of geochemical elements of the upper continental crust (UCC),except Si and Ca,all elements are depleted to a certain degree; Fe,Mg,Ca,P,Ti and Mn have high correlation coefficients in their contents.The mineral and geochemical composition of the Kumtagh Desert sediments have a similarity with that of rocks of Altyn Tagh Mountains,and the surface sediments of the alluvial/diluvial fans around the Altyn Tagh Mountains and that of the Taklamakan Desert,indicating that one major source of the Kumtagh Desert sediments is located in the Altyn Tagh Mountains.Alluvial deposits and lake sediments in Aqik valley and lower reaches of Shule River are prone to be eroded and transported by the strong northeasterly wind into the Kumtagh Desert,forming another source of the desert deposits.An A-CN-K ternary diagram shows that a weak degree chemical weathering by the loss of Na and K occurred in these sediments,whereas A-CNK-FM temary diagram suggests that Fe and Mg have undergone a significant chemical differentiation.Physical weathering processes cause easy erosion and enrichment in fine particles for mafic minerals,thus coarse desert sand particles can be relatively depleted in Fe and Mg.The mineral and geochemical composition of sediments in arid regions experiencing less chemical weathering are mostly affected by physical weathering.

  11. Health effects of particulate air pollution and airborne desert dust

    Science.gov (United States)

    Lelieveld, J.; Pozzer, A.; Giannadaki, D.; Fnais, M.

    2013-12-01

    Air pollution by fine particulate matter (PM2.5) has increased strongly with industrialization and urbanization. In the past decades this increase has taken place at a particularly high pace in South and East Asia. We estimate the premature mortality and the years of human life lost (YLL) caused by anthropogenic PM2.5 and airborne desert dust (DU2.5) on regional and national scales (Giannadaki et al., 2013; Lelieveld et al., 2013). This is based on high-resolution global model calculations that resolve urban and industrial regions in relatively great detail. We apply an epidemiological health impact function and find that especially in large countries with extensive suburban and rural populations, air pollution-induced mortality rates have been underestimated given that previous studies largely focused on the urban environment. We calculate a global premature mortality by anthropogenic aerosols of 2.2 million/year (YLL ≈ 16 million/year) due to lung cancer and cardiopulmonary disease. High mortality rates by PM2.5 are found in China, India, Bangladesh, Pakistan and Indonesia. Desert dust DU2.5 aerosols add about 0.4 million/year (YLL ≈ 3.6 million/year). Particularly significant mortality rates by DU2.5 occur in Pakistan, China and India. The estimated global mean per capita mortality caused by airborne particulates is about 0.1%/year (about two thirds of that caused by tobacco smoking). We show that the highest premature mortality rates are found in the Southeast Asia and Western Pacific regions (about 25% and 46% of the global rate, respectively) where more than a dozen of the most highly polluted megacities are located. References: Giannadaki, D., A. Pozzer, and J. Lelieveld, Modeled global effects of airborne desert dust on air quality and premature mortality, Atmos. Chem. Phys. Discuss. (submitted), 2013. Lelieveld, J., C. Barlas, D. Giannadaki, and A. Pozzer, Model calculated global, regional and megacity premature mortality due to air pollution by ozone

  12. CO2 EFFECTS ON MOJAVE DESERT PLANT INTERACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    L. A. DEFALCO; G. C. FERNANDEZ; S. D. SMITH; R. S. NOWAK

    2004-01-01

    Seasonal and interannual droughts characteristic of deserts have the potential to modify plant interactions as atmospheric CO{sub 2} concentrations continue to rise. At the Nevada Desert FACE (free-air CO{sub 2} enrichment) facility in the northern Mojave Desert, the effects of elevated atmospheric C02 (550 vs. ambient {approx}360 {micro}mol mol{sup -1}) on plant interactions were examined during two years of high and low rainfall. Results suggest that CO{sub 2} effects on the interaction between native species and their understory herbs are dependent on the strength of competition when rainfall is plentiful, but are unimportant during annual drought. Seasonal rainfall for 1999 was 23% the long-term average for the area, and neither elevated CO{sub 2} nor the low production of herbaceous neighbors had an effect on relative growth rate (RGR, d{sup -1}) and reproductive effort (RE, number of flowers g{sup -1}) for Achnatherum hymenoides (early season perennial C{sub 3} grass), Pleuraphis rigida (late season perennial C{sub 4} grass), and Larrea tridentata (evergreen C{sub 3} shrub). In contrast, 1998 received 213% the average rainfall. Consequently, the decrease in RGR and increase in RE for Achnatherum, whose period of growth overlaps directly with that of its neighbors, was exaggerated at elevated CO{sub 2}. However, competitive effects of neighbors on Eriogonum trichopes (a winter annual growing in shrub interspaces), Pleuraphis and Larrea were not affected by elevated CO{sub 2}, and possible explanations are discussed. Contrary to expectations, the invasive annual neighbor Bromus madritensis ssp. rubens had little influence on target plant responses because densities in 1998 and 1999 at this site were well below those found in other studies where it has negatively affected perennial plant growth. The extent that elevated CO{sub 2} reduces the performance of Achnatherum in successive years to cause its loss from the plant community depends more on future pressure

  13. Holocene Paleoecology of the Western Tenere Desert, Niger, Africa

    Science.gov (United States)

    Sereno, P. C.; Caran, S. C.; Housh, T. B.

    2007-12-01

    Multiple paleontological, sedimentological, and isotopic/ionic geochemical indicators permit reconstruction of the Holocene ecology of the western Tenere Desert (southern Sahara hyper-desert). Modern precipitation is highly erratic, averaging 25 mm yearly, and vegetative cover is negligible. From the early to middle Holocene, however, grassland-shrublands and seasonal to permanent lakes and wetlands predominated, supporting diverse limnic, riparian, and upland communities. Annual precipitation probably was comparable to that of the modern southern Sahel, exceeding 350 mm. Coarse-grained sediment washed into the large lacustrine basin from exposures of metamorphic, plutonic, and volcanic rocks in the nearby Air Massif highland. Lake margins fluctuated in response to runoff and limited ground-water discharge. The water was non-saline and there is no evidence of evaporite deposition. Aquatic and riparian macrophytes thrived, as did an extensive lacustrine-palustrine macrofauna. A Sahelian flora of mixed grasses, thorn shrubs, and perhaps some larger woodland species occupied the contiguous uplands, supporting resident and migratory mammalian and avian faunas. Lake levels were high until 6300 to 5200 BP, possibly as late as 4800 BP locally. Deflation of lacustrine deposits during a subsequent dry period provided finer-grained eolian sediment accreting as proximal dunes. The composition of mineral sediment within the middle to late Holocene dunes is different from, but clearly a subset of the lacustrine deposits. Organic matter reworked from the lake sediment was deposited in the dunes and oxidized in situ, generating CO2 that dissolved in soil moisture, producing bicarbonate. The bicarbonate reacted with calcium from weathered minerals, producing calcic cementation about 5100 BP. The resulting petrocalcic horizon was later exposed, weathered, and colonized by sparse terrestrial vegetation for one or more brief periods. A late phase of pedogenesis concurrent with or

  14. Swanea (Southwest Asia--Northeast Africa): A Climatological Study. Volume 2. The Middle East Peninsula

    Science.gov (United States)

    1992-09-01

    Sea along the Omani coastline. There ground. Because it contains several important are numerous large sebkhas in Oman. wadis and oasis, this is the most...RESERVOIRS. There are no lakes throughout the Ad Dahna. Sebkhas (level sand, or reservoirs in the desert, but there are silt, clay, and salt pans with a...throughout the Hijaz. Sebkhas have quicksand-type soils beneath the thin crust. VEGETATION. Most of the Arabian Desert is barren or sparsely covered

  15. Successional trends in Sonoran Desert abandoned agricultural fields in northern Mexico

    Science.gov (United States)

    Castellanos, A.E.; Martinez, M.J.; Llano, J.M.; Halvorson, W.L.; Espiricueta, M.; Espejel, I.

    2005-01-01

    Excessive ground-water use and saline intrusion to the aquifer led, in less than three decades, to an increase in abandoned agricultural fields at La Costa de Hermosillo, within the Sonoran Desert. Using a chronosequence from years since abandonment, patterns of field succession were developed. Contrary to most desert literature, species replacement was found, both in fields with and without saline intrusion. Seasonal photosynthetic capacity as well as water and nitrogen use efficiencies were different in dominant early and late successional plant species. These ecological findings provided a framework for a general explanation of species dominance and replacement within abandoned agricultural fields in the Sonoran Desert. ?? 2004 Elsevier Ltd. All rights reserved.

  16. Geochemical Information Indicating the Water Recharge to Lakes and Immovable Megadunes in the Badain Jaran Desert

    Institute of Scientific and Technical Information of China (English)

    CHEN Jiansheng; ZHAO Xia; SHENG Xuefeng; WANG Jiyang; GU Weizu; CHEN Liang

    2005-01-01

    Calc-sinters distributed in the middle of lakes and rhizoconcretions scattered at the slopes of sand dunes were observed during three explorations to the Badain Jaran Desert in the past two years.Wet sands were also found underneath the dry surface sand layers of about 20-50 cm in thickness.The geochemical parameters were measured on minerals and water samples collected from the Badain Jaran Desert and neighboring areas.The results show that the water system in the desert may be recharged from the groundwater originating from the precipitation of the Qilian Mountains and/or the Tibetan Plateau rather than the local rainfalls.

  17. Biotic Processes Regulating the Carbon Balance of Desert Ecosystems - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Robert S [UNR; Smith, Stanley D [UNLV; Evans, Dave [WSU; Ogle, Kiona [ASU; Fenstermaker, Lynn [DRI

    2012-12-13

    Our results from the 10-year elevated atmospheric CO{sub 2} concentration study at the Nevada Desert FACE (Free-air CO{sub 2} Enrichment) Facility (NDFF) indicate that the Mojave Desert is a dynamic ecosystem with the capacity to respond quickly to environmental changes. The Mojave Desert ecosystem is accumulating carbon (C), and over the 10-year experiment, C accumulation was significantly greater under elevated [CO{sub 2}] than under ambient, despite great fluctuations in C inputs from year to year and even apparent reversals in which [CO{sub 2}] treatment had greater C accumulations.

  18. Sexual conflict and consistency of offspring desertion in Eurasian penduline tit Remiz pendulinus

    Directory of Open Access Journals (Sweden)

    Pogány Ákos

    2008-09-01

    Full Text Available Abstract Background The trade-off between current and future parental investment is often different between males and females. This difference may lead to sexual conflict between parents over care provisioning in animals that breed with multiple mates. One of the most obvious manifestations of sexual conflict over care is offspring desertion whereby one parent deserts the young to increase its reproductive success at the expense of its mate. Offspring desertion is a wide-spread behavior, and its frequency often varies within populations. We studied the consistency of offspring desertion in a small passerine bird, the Eurasian penduline tit Remiz pendulinus, that has an extremely variable breeding system. Both males and females are sequentially polygamous, and a single parent (either the male or the female incubates the eggs and rears the young. About 28–40% of offspring are abandoned by both parents, and these offspring perish. Here we investigate whether the variation in offspring desertion in a population emerges either by each individual behaving consistently between different broods, or it is driven by the environment. Results Using a three-year dataset from Southern Hungary we show that offspring desertion by females is consistent between nests. Male desertion, however, depends on ambient environment, because all males desert their nests early in the season and some of them care late in the season. Therefore, within-population variation in parental care emerges by sexually different mechanisms; between-individual variation was responsible for the observed pattern of offspring desertion in females, whereas within-individual variation was responsible for the observed pattern in males. Conclusion To our knowledge, our study is the first that investigates repeatability of offspring desertion behavior in nature. The contrasting strategies of the sexes imply complex evolutionary trajectories in breeding behavior of penduline tits. Our results

  19. Desert farming benefits from microbial potential in arid soils and promotes diversity and plant health.

    Directory of Open Access Journals (Sweden)

    Martina Köberl

    Full Text Available BACKGROUND: To convert deserts into arable, green landscapes is a global vision, and desert farming is a strong growing area of agriculture world-wide. However, its effect on diversity of soil microbial communities, which are responsible for important ecosystem services like plant health, is still not known. METHODOLOGY/PRINCIPAL FINDINGS: We studied the impact of long-term agriculture on desert soil in one of the most prominent examples for organic desert farming in Sekem (Egypt. Using a polyphasic methodological approach to analyse microbial communities in soil as well as associated with cultivated plants, drastic effects caused by 30 years of agriculture were detected. Analysing bacterial fingerprints, we found statistically significant differences between agricultural and native desert soil of about 60%. A pyrosequencing-based analysis of the 16S rRNA gene regions showed higher diversity in agricultural than in desert soil (Shannon diversity indices: 11.21/7.90, and displayed structural differences. The proportion of Firmicutes in field soil was significantly higher (37% than in the desert (11%. Bacillus and Paenibacillus play the key role: they represented 96% of the antagonists towards phytopathogens, and identical 16S rRNA sequences in the amplicon library and for isolates were detected. The proportion of antagonistic strains was doubled in field in comparison to desert soil (21.6%/12.4%; disease-suppressive bacteria were especially enriched in plant roots. On the opposite, several extremophilic bacterial groups, e.g., Acidimicrobium, Rubellimicrobium and Deinococcus-Thermus, disappeared from soil after agricultural use. The N-fixing Herbaspirillum group only occurred in desert soil. Soil bacterial communities were strongly driven by the a-biotic factors water supply and pH. CONCLUSIONS/SIGNIFICANCE: After long-term farming, a drastic shift in the bacterial communities in desert soil was observed. Bacterial communities in agricultural

  20. The economics of hybrid power systems for sustainable desert agriculture in Egypt

    DEFF Research Database (Denmark)

    Kamel, S.M.; Dahl, C.

    2005-01-01

    Egypt has embarked on an ambitious desert land reclamation program in order to increase total food production. Energy planners for these desert agriculture locations have chosen diesel generation power technology because minimization of the initial capital cost of a power supply system is their top...... to investigate the economic potential of such systems in Egypt’s desert agriculture sector. Using optimization software, we assess the economics of hybrid power systems versus the present diesel generation technology in a remote agricultural development area. We also consider the emission reduction advantages...

  1. ENSO effects on primary productivity in Southern Atacama desert

    Directory of Open Access Journals (Sweden)

    F. A. Squeo

    2006-01-01

    Full Text Available In the winter-rain southern Atacama Desert of the Coquimbo Region of Chile, El Niño - Southern Oscillation (ENSO events modulate primary productivity. In this region, there are important changes in water availability between La Niña (dry and El Niño (rainy years. Using inter-annual comparisons of LANDSAT images from 30° to 31° S latitude, we observed changes in primary productivity between dry and rainy years at the regional level. There were also significant, negative correlations between productivity and elevation, with changes occurring first at low elevation during rainy years. The limiting factors to dryland vegetation primary productivity is different in regard to elevation. Rain during an El Niño year is the main factor that explains the increase in primary productivity at low elevation, while lower temperatures reduce and delay the net primary productivity at mid elevation.

  2. Southwest Center for Environmental Excellence and Opportunity Year End Report (Final Deliverable)

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-11-09

    The Southwest Center for Environmental Excellence and Opportunity (Southwest CEEO) has been in existence since October 1996 at Albuquerque Technical Vocational Institute's (TVI) South Valley Campus. The Special Project was comprised of three objectives: (1) Increasing the number of Hispanics in careers related to the environment by improving education and job training opportunities; (2) Strengthening the infrastructure of Hispanic businesses and building their capacity to participate in environmental clean-up activities and potential technology commercialization; and (3) Increasing the Hispanic community's understanding of and participation in environmental protection through improved access to information and outreach activities, paying attention to cultural and linguistic issues. The Southwest CEEO has been successful in each of the above objective areas and continues to provide valuable services to TVI and the community. The Southwest CEEO has developed a scholarship/mentorship program involving business and industry, community organizations, and TVI faculty that will be replicated by other student mentorship programs. The Southwest CEEO has awarded approximately $50,000 over the two-year program funded by the U.S. Department of Energy Oakland Operations Office. The Southwest CEEO has also developed a K-12 partnership with Albuquerque Public Schools (APS) to enhance environmental education for students and professional development for teachers. Incorporated into these student activities are experimental learning opportunities and curriculum development and/or enhancement. The Southwest CEEO has worked closely with the TVI Small Business Development Center (SBDC) to support Hispanic businesses in technology partnership activities. The Southwest CEEO in partnership the TVI SBDC has provided a large business forum and business workshops. In addition, the Southwest CEEO has developed a Technology Transfer Model that will be expanded in the future to a

  3. Sino-British Researchers Join Forces to Set Up an Alpine Botanic Garden in Southwest China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ The nameplate for the Lijiang Alpine Botanic Garden was unveiled on January 25 in southwest China's Yunnan Province.As a Sino-British cooperation project for a biodiversity research and protection and plant conservation platform in southwest China, the garden was jointly set up by the Royal Botanic Garden Edinburgh (RBGE)and the CAS Kunming Institute of Botany (KIB). The event also marked the start of a one-year UK-China Partners in Science campaign in southwest China. British ConsulGeneral in Chongqing Tim Summers,RBGE Regius Keeper Stephen Blackmore and KIB vice directors Li Dezhu and Yang Yongping were in Lijiang to witnessthe ceremony.

  4. A Case Study on the Role of Water Vapor from Southwest China in Downstream Heavy Rainfall

    Institute of Scientific and Technical Information of China (English)

    PAN Yang; YU Rucong; LI Jian; XU Youping

    2008-01-01

    Based on the observation data analysis and numerical simulation, the development of an eastward- moving vortex generated in Southwest China during the period 25-27 June 2003 is studied. The water vapor budget analysis indicates that water vapor in the lower troposphere over Southwest China is transported downstream to the Yangtze and Huaihe River valleys by the southwesterly winds south of the vortex center. A potential vorticity (PV) budget analysis reveals that a positive feedback between latent heat release and low-level positive vorticity plays a vital role in the sudden development and eastward movement of the vortex. Numerical simulations are consistent with these results.

  5. Arbuscular mycorrhizal fungi (Glomales, Zygomycota of the Bledowska Desert, Poland

    Directory of Open Access Journals (Sweden)

    Janusz Błaszkowski

    2014-01-01

    Full Text Available The occurrence of arbuscular mycorrhizal fungi (AMF; Glomales, Zygomycetes associated with plants growing in sand dune soils of the Blędowska Desert, Poland, was investigated in 1995-1997. A total of 134 mixtures of soils and roots were sampled. The mixtures represented 26 plant species in 14 families and one unrecognized plant. Spores of AMF were found in 118 soil-root mixtures. The AMF spore populations comprised 20 described species of the genera Acaulospora, Gigaspora, Glomus and Scutellospora, as well as two undescribed morphospecies of the genus Glomus. The AMF most frequently occurring in the field-collected soils were members of the genus Scutellospora The AMF spore populations comprised 20 described species in the genera Acaulospora, Gigaspora, Glomus and Scutellospora, as well as two undescribed morpho-species of the genus Glomus. The fungal species most frequently and numerously found was Scutellospora armeniaca. The fungi relatively frequently present also were A. rugosa, A. lacunosa, G. aggregatum, an undescribed Glomus 142 and Sc. dipurpurescens. The overall spore abundance of AMF averaged 69.1 and ranged from 0 to 837 in 100 g dry soil. The highest abundance of spores occurred among roots of the families Cupressaceae, followed by the Rosaceae, Asteraceae and Poaceae. Of the plant species investigated two and more times, most spores harboured Juniperus communis. The overall average species richness was 2.4 and ranged from 0 to 6 in 100 g dry soil. Of the plant species sampled at lest two times, the highest average species diversity was found in the root zone of Salix arenaria. The plant species that hosted the highest overall number of species of AMF was Festuca rubra. Trap pot cultures with soilroot mixtures collected in 1997 revealed 10 species of AMF that were not found in field soils sampled in the same year. This suggests that a great part of AMF of Błędowska Desert is represented by rarely or non-sporulating species.

  6. The Holocene Geoarchaeology of the Desert Nile in Northern Sudan

    Science.gov (United States)

    Woodward, Jamie; Macklin, Mark; Spencer, Neal; Welsby, Derek; Dalton, Matthew; Hay, Sophie; Hardy, Andrew

    2016-04-01

    Invited Paper Forty years ago Colin Renfrew declared that "every archaeological problem starts as a problem in geoarchaeology" (Renfrew, 1976 p. 2). With this assertion in mind, this paper draws upon the findings from field research in two sectors of the Nile Valley of Northern Sudan dedicated to the exploration of human-environment interactions during the middle and late Holocene. This part of the Nile corridor contains a rich cultural record and an exceptionally well preserved Holocene fluvial archive. A distinctive feature of these records is the variety of evidence for interaction between desert and river over a range of spatial and temporal scales. This interaction presented both challenges and opportunities for its ancient inhabitants. This paper will present evidence for large-scale landscape changes driven by shifts in global climate. It will also show how we have integrated the archaeological and geological records in the Northern Dongola Reach and at Amara West - where long-term field projects led by archaeologists from the British Museum have recognised the importance of a sustained commitment to interdisciplinary research to achieve a fully integrated geoarchaeological approach across a range of scales. The former project is a large-scale landscape survey with multiple sites across an 80 km reach of the Nile whilst the latter has a strong focus on a single New Kingdom town site and changes in its environmental setting. By combining multiple archaeological and geological datasets - and pioneering the use of OSL dating and strontium isotope analysis in the Desert Nile - we have developed a new understanding of human responses to Holocene climate and landscape change in this region. Renfrew, C. (1976) Archaeology and the earth sciences. In: D.A. Davidson and M.I. Shackley (eds) Geoarchaeology: Earth Science and the Past, Duckworth, London, 1-5.

  7. Mesofaunal biodiversity and its importance in Thar desert.

    Science.gov (United States)

    Tripathi, G; Kumari, R; Sharma, B M

    2007-04-01

    Soil animals are considered as important contributors to soil fertility However, there is paucity of such information for harsh climatic conditions. Therefore, the below ground faunal density and frequency have been studied in relation to physicochemical properties of soil in Thar desert. The selected soil systems were Vigna radiata--Cuminum cyminum, grassland, flower garden and Zizyphus mauritiana. Acari and other soil arthropods exhibited seasonal variation in their populations. There were two population peaks, one in February/March and other in August/September. The highest population was in flower garden, whereas lowest was in Z. mauritiana field. It clearly indicates that the soil fauna population develops in different degrees. The relative density showed that the acarines were more prevalent in comparison to other soil arthropods. The prostigmatids exhibited maximum relative density in comparison to cryptostigmatids and mesostigmatids in all fields. Pauropus showed higher relative density among all other soil arthropods. Acari had higher frequency of occurrence, while the other soil arthropods indicated lower frequency of occurrence in all systems. The highest frequency of occurrence was recorded in July/August and the lowest in May/June. The soil temperature, moisture, organic carbon, total nitrogen and carbon/nitrogen ratio varied significantly throughout the year The fluctuations in physicochemical characteristics of soil greatly influenced below ground faunal density in different fields. A highly significant and positive correlation was obtained among different soil fauna groups. Faunal population showed a significant positive correlation with soil moisture, organic carbon and total nitrogen. The abiotic factors such as temperature, pH and C/N ratio showed negative correlation with moisture, organic carbon and total nitrogen. However, moisture, organic carbon and total nitrogen had positive correlation among themselves. The present study suggests that the

  8. Cacti supply limited nutrients to a desert rodent community.

    Science.gov (United States)

    Orr, Teri J; Newsome, Seth D; Wolf, Blair O

    2015-08-01

    In the Sonoran Desert, cacti represent a potentially important source of nutrients and water for consumers. Columnar cacti, in particular, produce a large pulse of flowers and succulent fruit during hot summer months. The importance of cactus stems, flowers and fruit to the small mammal community has not been quantified. We exploited natural variation in the carbon isotope (δ(13)C) values of cacti (CAM) versus C3 plants to quantify the relative use of these resources by a diverse desert small mammal community. We also estimated trophic level by measuring nitrogen isotope (δ(15)N) values. We hypothesized that (H1) granivorous heteromyids (kangaroo rats, pocket mice) would exploit the summer pulse of seeds and pulp; (H2) folivorous and omnivorous cactus mice, wood rats, and ground squirrels would exploit cacti stems year-round and seeds when available; and (H3) kangaroo rats and pocket mice would shift from seeds to insects during hot dry months. We found that heteromyids made minimal use of seeds during the period of heavy seed rain. Of the cricetids, only the folivore Neotoma albigula made continuous but highly variable use of cacti resources (annual mean = 32%, range 0-81%), whereas the omnivore Peromyscus eremicus ignored cacti except during the summer, when it exploited seeds and/or fruit pulp (June-July mean = 39%, range 20-64%). We also found little evidence for a shift to greater consumption of insects by heteromyids during the hot dry months. Overall, use of cactus resources by the small mammal community is very limited and highly variable among species.

  9. Controls on sediment production in two U.S. deserts

    Science.gov (United States)

    Belnap, Jayne; Walker, Beau J.; Munson, Seth M.; Gill, Richard A.

    2014-01-01

    Much of the world’s airborne sediment originates from dryland regions. Soil surface disturbances in these regions are ever-increasing due to human activities such as energy and mineral exploration and development, recreation, suburbanization, livestock grazing and cropping. Sediment production can have significant impacts to human health with particles potentially carrying viruses such as Valley Fever or causing asthma or other respiratory diseases. Dust storms can cause decreased visibility at the ground level, resulting in highway accidents, and reduced visual quality in park and wildland airsheds. Sediment production and deposition is also detrimental to ecosystem health, as production reduces soil fertility at its source and can bury plants and other organisms where it is deposited. Therefore, it is important to understand how we can predict what areas are prone to producing sediment emissions both before and after soil surface disturbance. We visited 87 sites in two deserts of the western U.S. that represented a range of soil texture and surface cover types. We used a portable wind tunnel to estimate the threshold friction velocity (TFV) required to initiate sediment transport and the amount of sediment produced by the tunnel at a set wind speed. Wind tunnel runs were done before and after soil surface disturbance with a four-wheel drive vehicle. Results show that most undisturbed desert soils are very stable, especially if covered by rocks or well-developed biological soil crusts, which make them virtually wind-erosion proof. Particles at disturbed sites, in contrast, moved at relatively low wind speeds and produced high amounts of sediment. Silt was an important predictor of TFV and sediment production across all sites, whereas the influence of rock cover and biological soil crusts was site-dependent. Understanding the vulnerability of a site after disturbance is important information for land managers as they plan land use activities and attempt to

  10. Subcritical Water Extraction of Amino Acids from Atacama Desert Soils

    Science.gov (United States)

    Amashukeli, Xenia; Pelletier, Christine C.; Kirby, James P.; Grunthaner, Frank J.

    2007-01-01

    Amino acids are considered organic molecular indicators in the search for extant and extinct life in the Solar System. Extraction of these molecules from a particulate solid matrix, such as Martian regolith, will be critical to their in situ detection and analysis. The goals of this study were to optimize a laboratory amino acid extraction protocol by quantitatively measuring the yields of extracted amino acids as a function of liquid water temperature and sample extraction time and to compare the results to the standard HCl vapor- phase hydrolysis yields for the same soil samples. Soil samples from the Yungay region of the Atacama Desert ( Martian regolith analog) were collected during a field study in the summer of 2005. The amino acids ( alanine, aspartic acid, glutamic acid, glycine, serine, and valine) chosen for analysis were present in the samples at concentrations of 1 - 70 parts- per- billion. Subcritical water extraction efficiency was examined over the temperature range of 30 - 325 degrees C, at pressures of 17.2 or 20.0 MPa, and for water- sample contact equilibration times of 0 - 30 min. None of the amino acids were extracted in detectable amounts at 30 degrees C ( at 17.2 MPa), suggesting that amino acids are too strongly bound by the soil matrix to be extracted at such a low temperature. Between 150 degrees C and 250 degrees C ( at 17.2 MPa), the extraction efficiencies of glycine, alanine, and valine were observed to increase with increasing water temperature, consistent with higher solubility at higher temperatures, perhaps due to the decreasing dielectric constant of water. Amino acids were not detected in extracts collected at 325 degrees C ( at 20.0 MPa), probably due to amino acid decomposition at this temperature. The optimal subcritical water extraction conditions for these amino acids from Atacama Desert soils were achieved at 200 degrees C, 17.2 MPa, and a water- sample contact equilibration time of 10 min.

  11. How much Carbon is Stored in Deserts? AN Approach for the Chilean Atacama Desert Using LANDSAT-8 Products

    Science.gov (United States)

    Hernández, H. J.; Acuña, T.; Reyes, P.; Torres, M.; Figueroa, E.

    2016-06-01

    The Atacama Desert in northern Chile is known as the driest place on Earth, with an average rainfall of about 15 mm per year. Despite these conditions, it contains a rich variety of flora with hundreds of species characterised by their extraordinary ability to adapt to this extreme environment. These biotic components have a direct link to important ecosystem services, especially those related to carbon storage and sequestration. No quantitative assessment is currently available for these services and the role of the desert in this matter remains unclear. We propose an approach to estimate above-ground biomass (AGB) using Landsat-8 data, which we tested in the Taparacá region, located in the northern section of the desert. To calibrate and validate the models, we used field data from 86 plots and several spectral indexes (NDVI, EVI and SAVI) obtained from the provisional Landsat-8 Surface-reflectance products. We applied randomised branch sampling and allometry principles (non-destructive methods) to collect biomass samples for all plant biological types: wetlands, steppes, shrubs and trees. All samples were dried in an oven until they reached constant weight and the final values were used to extrapolate dry matter content (AGB) to each plot in terms of kg m-2. We used all available scenes from September 2014 to August 2015 to calculate the maximum, minimum and average value for each index in each pixel within this period. For modeling, we used the method based on classification and regression trees called random forest (RF), available in the statistical software R-Project. The explained variance obtained by the RF algorithm was around 80-85%, and it improved when a wetland vector layer was used as the predictive factor in the model to reach the range 85-90%. The mean error was 1.45 kg m-2 of dry matter. The best model was obtained using the maximum and mean values of SAVI and EVI indexes. We were able to estimate total biomass storage of around 8 million tons

  12. HOW MUCH CARBON IS STORED IN DESERTS? AN APPROACH FOR THE CHILEAN ATACAMA DESERT USING LANDSAT-8 PRODUCTS

    Directory of Open Access Journals (Sweden)

    H. J. Hernández

    2016-06-01

    Full Text Available The Atacama Desert in northern Chile is known as the driest place on Earth, with an average rainfall of about 15 mm per year. Despite these conditions, it contains a rich variety of flora with hundreds of species characterised by their extraordinary ability to adapt to this extreme environment. These biotic components have a direct link to important ecosystem services, especially those related to carbon storage and sequestration. No quantitative assessment is currently available for these services and the role of the desert in this matter remains unclear. We propose an approach to estimate above-ground biomass (AGB using Landsat-8 data, which we tested in the Taparacá region, located in the northern section of the desert. To calibrate and validate the models, we used field data from 86 plots and several spectral indexes (NDVI, EVI and SAVI obtained from the provisional Landsat-8 Surface-reflectance products. We applied randomised branch sampling and allometry principles (non-destructive methods to collect biomass samples for all plant biological types: wetlands, steppes, shrubs and trees. All samples were dried in an oven until they reached constant weight and the final values were used to extrapolate dry matter content (AGB to each plot in terms of kg m-2. We used all available scenes from September 2014 to August 2015 to calculate the maximum, minimum and average value for each index in each pixel within this period. For modeling, we used the method based on classification and regression trees called random forest (RF, available in the statistical software R-Project. The explained variance obtained by the RF algorithm was around 80-85%, and it improved when a wetland vector layer was used as the predictive factor in the model to reach the range 85-90%. The mean error was 1.45 kg m-2 of dry matter. The best model was obtained using the maximum and mean values of SAVI and EVI indexes. We were able to estimate total biomass storage of around 8

  13. Desert Cyanobacteria under simulated space and Martian conditions

    Science.gov (United States)

    Billi, D.; Ghelardini, P.; Onofri, S.; Cockell, C. S.; Rabbow, E.; Horneck, G.

    2008-09-01

    The environment in space and on planets such as Mars, can be lethal to living organisms and high levels of tolerance to desiccation, cold and radiation are needed for survival: rock-inhabiting cyanobacteria belonging to the genus Chroococcidiopsis can fulfil these requirements [1]. These cyanobacteria constantly appear in the most extreme and dry habitats on Earth, including the McMurdo Dry Valleys (Antarctica) and the Atacama Desert (Chile), which are considered the closest terrestrial analogs of two Mars environmental extremes: cold and aridity. In their natural environment, these cyanobacteria occupy the last refuges for life inside porous rocks or at the stone-soil interfaces, where they survive in a dry, dormant state for prolonged periods. How desert strains of Chroococcidiopsis can dry without dying is only partially understood, even though experimental evidences support the existence of an interplay between mechanisms to avoid (or limit) DNA damage and repair it: i) desert strains of Chroococcidiopsis mend genome fragmentation induced by ionizing radiation [2]; ii) desiccation-survivors protect their genome from complete fragmentation; iii) in the dry state they show a survival to an unattenuated Martian UV flux greater than that of Bacillus subtilis spores [3], and even though they die following atmospheric entry after having orbited the Earth for 16 days [4], they survive to simulated shock pressures up to 10 GPa [5]. Recently additional experiments were carried out at the German Aerospace Center (DLR) of Cologne (Germany) in order to identify suitable biomarkers to investigate the survival of Chroococcidiopsis cells present in lichen-dominated communities, in view of their direct and long term space exposition on the International Space Station (ISS) in the framework of the LIchens and Fungi Experiments (LIFE, EXPOSEEuTEF, ESA). Multilayers of dried cells of strains CCMEE 134 (Beacon Valley, Antarctica), and CCMEE 123 (costal desert, Chile ), shielded by

  14. High-temperature responses of North American cacti

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S.D.; Didden-Zopfy, B.; Nobel, P.S.

    1984-04-01

    High-temperature tolerances of 14 species of North American cacti were investigated. A reduction in the proportion of chlorenchyma cells taking up a vital stain (neutral red) and reduced nocturnal acid accumulation were used as indicators of high-temperature damage. All species tolerated relatively high tissue temperatures, the mean maximum tolerance being 64/sup 0/C, with an absolute maximum of 69/sup 0/ for two species of ferocactus. Such tissue tolerances to high temperature may be unsurpassed in vascular plants. Morphological features can affect tissue temperatures. Specifically, thin-stemmed species such as the cylindropuntias attain lower maximum temperatures under identical microclimatic conditions than do more massive species; they also tend to be less tolerant of high-temperature stress. Stem diameter changes of three species of columnar ceriod cacti along a Sonoran Desert latitudinal transect were previously attributed to adaptation to progressively colder temperatures northward. Such changes can also be interpreted as a morphological adaptation to high temperatures, particularly in the southern Sonoran Desert. Interspecific differences in high-temperature tolerance may account for distributional differences among other species. Acclimation of high-temperature tolerances in response to increasing day/night air temperatures was observed in all 14 species, especially at higher growh temperatures. From 40/sup 0/ day/30/sup 0/ night to 50/sup 0//40/sup 0/, the tolerable tissue temperatures increased an average of 6/sup 0/. Half-times for the acclimation shifts were 1-3d. Although cacti attain extremely high tissue temperatures in desert habitats, tolerance of high temperatures and pronounced acclimation potential allow them to occur in some of the hottest habitats in North America.

  15. Close relationships between Asian American and European American college students.

    Science.gov (United States)

    Chen, C; Edwards, K; Young, B; Greenberger, E

    2001-02-01

    The authors examined attitudes and behaviors regarding close relationships between European and Asian Americans, with a particular emphasis on 5 major subgroups of Asian Americans (Chinese, Japanese, Korean, Vietnamese, and Filipino Americans). Participants were 218 Asian American college students and 171 European American college students attending a culturally diverse university. The European Americans did not differentiate among the various subgroups of Asian Americans. Their attitudes regarding close relationships were less positive toward Asian Americans than toward Mexican and African Americans, a finding contrary to the prediction of social exchange theory (H. Tajfel, 1975). In contrast to the European Americans' view of homogeneity among Asian Americans, the 5 major subgroups of Asian Americans expressed a distinctive hierarchy of social preference among themselves. Results are discussed in terms of their implications for future research on interethnic relations involving Asian Americans.

  16. Paleomonsoonal Precipitation and Hydroclimate Variability from Glacial to Interglacial Climates in the Southwest: The Stoneman Lake, Arizona Record

    Science.gov (United States)

    Garcia, D.; Fawcett, P. J.; Anderson, R. S.; Sharp, Z. D.

    2015-12-01

    Oxygen isotope values from diatom silica have been used to determine past hydrological conditions in a variety of settings including differentiating summer monsoonal paleoprecipitation from winter frontal paleoprecipitation in the American southwest. Lacustrine cores from the Valles Caldera, New Mexico, show a distinct change in silica oxygen isotope values from glacial to interglacial as a switch from a purely winter frontal precipitation during the glacial to a mix of winter frontal and summer monsoonal precipitation during the interglacial. A relatively large (ca. 20‰) and rapid increase in δ18O following the glacial termination implies an abrupt onset of the North American monsoon. We plan to elaborate on this research to see if this is true elsewhere in the southwest. Two lacustrine sediment cores (70 m deep and 30 m deep respectively) were recovered from Stoneman Lake, northern Arizona in October of 2014. With these cores we plan to determine regional hydroclimate variability between the Pleistocene-Holocene glacial transition ca. 14 ka. Oxygen isotope analysis from diatom silica will allow us to determine past sources of precipitation to the basin (Gulf of Mexico vs North Pacific), and paleoprecipitation variability. In conjunction with other proxies, we can determine if the onset of paleomonsoonal precipitation in central Arizona occurs immediately after the glacial termination as in NM, or if there is some component of monsoonal precipitation during the late glacial period. Diatom sampling was performed at approximately every 50 cm. To purify the diatoms, the samples are chemically and physically separated. The step wise fluorination and laser ablation technique are then applied to remove water & hydroxyl groups and to extract O2 & SiF4 respectively.If results from the Stoneman Lake core are similar to that of the Valles Caldera core, we should expect to see a nearly 20‰ increase in δ18Olake water. This would suggest a: 1) collapse of the summer

  17. Metabolic rate, evaporative water loss and thermoregulatory state in four species of bats in the Negev desert.

    Science.gov (United States)

    Muñoz-Garcia, Agustí; Larraín, Paloma; Ben-Hamo, Miriam; Cruz-Neto, Ariovaldo; Williams, Joseph B; Pinshow, Berry; Korine, Carmi

    2016-01-01

    Life in deserts is challenging for bats because of their relatively high energy and water requirements; nevertheless bats thrive in desert environments. We postulated that bats from desert environments have lower metabolic rates (MR) and total evaporative water loss (TEWL) than their mesic counterparts. To test this idea, we measured MR and TEWL of four species of bats, which inhabit the Negev desert in Israel, one species mainly restricted to hyper-arid deserts (Otonycteris hemprichii), two species from semi-desert areas (Eptesicus bottae and Plecotus christii), and one widespread species (Pipistrellus kuhlii). We also measured separately, in the same individuals, the two components of TEWL, respiratory water loss (RWL) and cutaneous evaporative water loss (CEWL), using a mask. In all the species, MR and TEWL were significantly reduced during torpor, the latter being a consequence of reductions in both RWL and CEWL. Then, we evaluated whether MR and TEWL in bats differ according to their geographic distributions, and whether those rates change with Ta and the use of torpor. We did not find significant differences in MR among species, but we found that TEWL was lowest in the species restricted to desert habitats, intermediate in the semi-desert dwelling species, and highest in the widespread species, perhaps a consequence of adaptation to life in deserts. Our results were supported by a subsequent analysis of data collected from the literature on rates of TEWL for 35 bat species from desert and mesic habitats.

  18. Discovery and geology of the Desert Peak geothermal field: a case history. Bulletin 97

    Energy Technology Data Exchange (ETDEWEB)

    Benoit, W.R.; Hiner, J.E.; Forest, R.T.

    1982-09-01

    A case history of the exploration, development (through 1980), and geology of the Desert Peak geothermal field is presented. Sections on geochemistry, geophysics, and temperature-gradient drilling are included.

  19. Response of lizard community structure to desert grassland restoration mediated by a keystone rodent

    Science.gov (United States)

    Many grasslands in the Chihuahuan Desert have transformed to shrublands dominated by creosotebush (Larrea tridentata). Grassland restoration efforts have been directed at controlling creosotebush by applying herbicide over large spatial scales. However, we have a limited understanding of how landsca...

  20. Department of the Interior : Final Environmental Statement : FES 75-76 : Proposed Desert Wilderness Area

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a final analysis of the environmental impact wilderness designation would pose for the Desert Wilderness Area. Topics covered include where the...