WorldWideScience

Sample records for car-crazy north america

  1. Battling gridlock : congestion fees are working in Europe and Asia, but its questionable if they will succeed in car-crazy North America

    Energy Technology Data Exchange (ETDEWEB)

    Carnevale, R. [Colleges Integrating Immigrants to Employment, Toronto, ON (Canada); Crawford, E.A. [York Univ., Toronto, ON (Canada). Faculty of Environmental Studies

    2008-07-01

    This article described different traffic congestion schemes that cities around the world have adopted to ease traffic grid-lock. Congestion fees that discourage road use involve assigning a price to a road based on the demand for using that road. A weekday congestion fee which was imposed on drivers in the city of London in 2003 resulted in a 30 per cent drop in vehicular traffic in the city centre. The pricing structure was independent of vehicle type, distance travelled or time of day. The successful scheme is credited with an increase in cycling and public transit ridership as well as a decrease in accidents and air pollution without hindering business within the congestion zone. However, the effectiveness of congestion fees in North America is questionable. Although San Diego's high-occupancy toll lanes have helped reduce congestion and pollution because the revenue raised is invested in public transportation, objections have been raised regarding plans to implement congestion fees in San Francisco and New York city centres because doing so would prevent those with low incomes from driving in the city. London has responded to such challenges by putting all net revenues derived from the fees back into public transportation. Similar measures were taken in Stockholm, Sweden where massive improvements were made to its transit system prior to introducing congestion fees to avert criticism. In order for congestion fees to be effective and gain public approval, there should be clear objectives that include demand management, good transportation alternatives, revenues that go to public transit and a simple pricing system that uses proven technology. The cumulative annual cost of congestion in 9 urban centres in Canada ranged from $2.3 billion to $3.7 billion in 2002 according to Transport Canada. Analysts have cautioned that congestion schemes would be difficult to duplicate in North American cities that are highly dependent on automobiles. However, the authors

  2. Battling gridlock : congestion fees are working in Europe and Asia, but its questionable if they will succeed in car-crazy North America

    International Nuclear Information System (INIS)

    Carnevale, R.; Crawford, E.A.

    2008-01-01

    This article described different traffic congestion schemes that cities around the world have adopted to ease traffic grid-lock. Congestion fees that discourage road use involve assigning a price to a road based on the demand for using that road. A weekday congestion fee which was imposed on drivers in the city of London in 2003 resulted in a 30 per cent drop in vehicular traffic in the city centre. The pricing structure was independent of vehicle type, distance travelled or time of day. The successful scheme is credited with an increase in cycling and public transit ridership as well as a decrease in accidents and air pollution without hindering business within the congestion zone. However, the effectiveness of congestion fees in North America is questionable. Although San Diego's high-occupancy toll lanes have helped reduce congestion and pollution because the revenue raised is invested in public transportation, objections have been raised regarding plans to implement congestion fees in San Francisco and New York city centres because doing so would prevent those with low incomes from driving in the city. London has responded to such challenges by putting all net revenues derived from the fees back into public transportation. Similar measures were taken in Stockholm, Sweden where massive improvements were made to its transit system prior to introducing congestion fees to avert criticism. In order for congestion fees to be effective and gain public approval, there should be clear objectives that include demand management, good transportation alternatives, revenues that go to public transit and a simple pricing system that uses proven technology. The cumulative annual cost of congestion in 9 urban centres in Canada ranged from $2.3 billion to $3.7 billion in 2002 according to Transport Canada. Analysts have cautioned that congestion schemes would be difficult to duplicate in North American cities that are highly dependent on automobiles. However, the authors

  3. North America: Chapter 5

    Science.gov (United States)

    Schwartz, Mark D.; Beaubien, Elisabeth G.; Crimmins, Theresa M.; Weltzin, Jake F.; Edited by Schwartz, Mark D.

    2013-01-01

    Plant phenological observations and networks in North America have been largely local and regional in extent until recent decades. In the USA, cloned plant monitoring networks were the exception to this pattern, with data collection spanning the late 1950s until approximately the early 1990s. Animal observation networks, especially for birds have been more extensive. The USA National Phenology Network (USA-NPN), established in the mid-2000s is a recent effort to operate a comprehensive national-scale network in the United States. In Canada, PlantWatch, as part of Nature Watch, is the current national-scale plant phenology program.

  4. North America pipeline map

    International Nuclear Information System (INIS)

    Anon.

    2005-01-01

    This map presents details of pipelines currently in place throughout North America. Fifty-nine natural gas pipelines are presented, as well as 16 oil pipelines. The map also identifies six proposed natural gas pipelines. Major cities, roads and highways are included as well as state and provincial boundaries. The National Petroleum Reserve is identified, as well as the Arctic National Wildlife Refuge. The following companies placed advertisements on the map with details of the services they provide relating to pipeline management and construction: Ferus Gas Industries Trust; Proline; SulfaTreat Direct Oxidation; and TransGas. 1 map

  5. Clitopilus argentinus in North America

    NARCIS (Netherlands)

    Baroni, Timothy J.

    1992-01-01

    Clitopilus argentinus is reported for the first time from North America. A full description and illustrations of the basidiomata and microscopic structures are provided. An X-ray elemental analysis of the diagnostic ‘hyaline’ incrustations of the pileus surface shows these extracellular structures

  6. Heart Failure in North America

    OpenAIRE

    Blair, John E. A; Huffman, Mark; Shah, Sanjiv J

    2013-01-01

    Heart failure is a major health problem that affects patients and healthcare systems worldwide. Within the continent of North America, differences in economic development, genetic susceptibility, cultural practices, and trends in risk factors and treatment all contribute to both inter-continental and within-continent differences in heart failure. The United States and Canada represent industrialized countries with similar culture, geography, and advanced economies and infrastructure. During t...

  7. Arthropod Envenomation in North America.

    Science.gov (United States)

    Erickson, Timothy B; Cheema, Navneet

    2017-05-01

    Arthropods (phylum Arthopoda) account for a higher percentage of morbidity and mortality to humans than do mammalian bites, snake bites, or marine envenomation. They are ubiquitous in domestic dwellings, caves, and campsites and in wilderness settings such as deserts, forests, and lakes. Although arthropods are most intrusive during warmer months, many are active throughout the winter, particularly indoors. Arthropods are also nocturnal and often bite unsuspecting victims while they are sleeping. Encounters with humans are generally defensive, accidental, or reactive. An individual stung by an insect or bitten by an arachnid may experience pain and local swelling, an anaphylactic reaction, or life-threatening toxicity. This review discusses the clinical presentation and latest treatment recommendations for bites and stings from spiders, scorpions, bees, ants, ticks and centipedes of North America. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Juncus planifolius (Juncaceae) in North America

    DEFF Research Database (Denmark)

    Balslev, Henrik

    1980-01-01

    Juncus planifolius is reported for the first time from North America. Bibliographic notes on this species and its synonymy are given. Its distribution, dispersal and relationships within the genus are discussed.......Juncus planifolius is reported for the first time from North America. Bibliographic notes on this species and its synonymy are given. Its distribution, dispersal and relationships within the genus are discussed....

  9. 76 FR 14101 - Bruss North America; Russell Springs, KY; Bruss North America; Orion, MI; Amended Revised...

    Science.gov (United States)

    2011-03-15

    ... America; Russell Springs, KY; Bruss North America; Orion, MI; Amended Revised Determination on... relevant time period at the Orion, Michigan location of Bruss North America, Inc. The Orion, Michigan..., Kentucky facility also led to worker separations at the Orion, Michigan location during the relevant time...

  10. Forest Health Status in North America

    Directory of Open Access Journals (Sweden)

    Borys Tkacz

    2007-01-01

    Full Text Available The forests of North America provide a variety of benefits including water, recreation, wildlife habitat, timber, and other forest products. However, they continue to face many biotic and abiotic stressors including fires, native and invasive pests, fragmentation, and air pollution. Forest health specialists have been monitoring the health of forests for many years. This paper highlights some of the most damaging forest stressors affecting North American forests in recent years and provides some projections of future risks.

  11. Tall Tales of North America.

    Science.gov (United States)

    Fresno City Unified School District, CA.

    Designed for use in junior high school language arts classes, this learning activity packet introduces students to North American folklore. Selected readings cover Indian tales, real folk heroes (Davy Crockett and John Henry), imaginary folk heroes (Paul Bunyan and Pecos Bill), Black folk stories (Brer Rabbit), and tales of Washington Irving. Each…

  12. Structural (Performance) class Potential for North America

    Science.gov (United States)

    Eric Jones; David E. Kretschmann; Kevin Cheung

    2014-01-01

    Structural class systems are species-independent product classification systems for structural timber. They are used throughout the world to reduce the number of species and grade choices that face the designer of wood construction projects. Structural class systems offer an opportunity to simplify timber specification in North America and to encourage more effective...

  13. Status of soil acidification in North America

    Science.gov (United States)

    M. E. Fenn; T. G. Huntington; S. B. McLaughlin; C. Eagar; A. Gomez; R. B. Cook

    2006-01-01

    Forest soil acidification and depletion of nutrient cations have been reported for several forested regions in North America, predominantly in the eastern United States, including the northeast and in the central Appalachians, but also in parts of southeastern Canada and the southern U.S. Continuing regional inputs of nitrogen and sulfur are of concern because of...

  14. Rat Lungworm Expands into North America

    Centers for Disease Control (CDC) Podcasts

    2016-01-21

    Emily York, integrated pest management specialist at the Sam Noble Museum of Natural History, discusses the rat lungworm expansion in North America.  Created: 1/21/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 1/21/2016.

  15. Forest health conditions in North America

    International Nuclear Information System (INIS)

    Tkacz, Borys; Moody, Ben; Castillo, Jaime Villa; Fenn, Mark E.

    2008-01-01

    Some of the greatest forest health impacts in North America are caused by invasive forest insects and pathogens (e.g., emerald ash borer and sudden oak death in the US), by severe outbreaks of native pests (e.g., mountain pine beetle in Canada), and fires exacerbated by changing climate. Ozone and N and S pollutants continue to impact the health of forests in several regions of North America. Long-term monitoring of forest health indicators has facilitated the assessment of forest health and sustainability in North America. By linking a nationwide network of forest health plots with the more extensive forest inventory, forest health experts in the US have evaluated current trends for major forest health indicators and developed assessments of future risks. Canada and Mexico currently lack nationwide networks of forest health plots. Development and expansion of these networks is critical to effective assessment of future forest health impacts. - The forests of North America continue to face many biotic and abiotic stressors including fragmentation, fires, native and invasive pests, and air pollution

  16. The genus Kochia (Chenopodiaceae) in North America

    Science.gov (United States)

    Ge-Lin Chu; Stewart Sanderson

    2008-01-01

    The genus Kochia and Bassia with which it has been combined, of Chenopodiaceae tribe Camphorosmeae, were at one time considered to include plants native to Eurasia, Australia, and North America, and included species of both C3 and C4 photosynthetic types. This aggregate has been reduced in size by removal of a large group of C3 Australian genera and species. Because of...

  17. Chapter 13, Policy options: North America

    Science.gov (United States)

    Jane Barr; James Dobrowolski; John Campbell; Philippe Le Prestre; Lori Lynch; Marc Sydnor; Robert Adler; Jose Etcheverry; Alexander Kenny; Catherine Hallmich; Jim Lazar; Russell M. Meyer; Robin Newmark; Janet Peace; Julie A. Suhr Pierce; Stephen. Yamasaki

    2012-01-01

    As previously indicated, GEO-5 shifts the GEO focus from identifying environmental problems to identifying solutions that governments can then prioritize. This chapter provides examples of a number of policy options and market mechanisms that have shown some success in improving environmental conditions in North America. They are organized by priority environmental...

  18. Book review: Bumble bees of North America

    Science.gov (United States)

    O'Dell, Samuel

    2015-01-01

    Bumblebee identification is generally considered straightforward, yet mistakes often are made due to the degree of similarity between the color patterns of different species. Bumble Bees of North America aims to improve the accuracy of identifications by both casual observers and professionals through the use of intuitive diagrams, descriptions, and the more technical dichotomous keys. In addition to providing the first complete field guide to North American bumblebees, the authors make efficient use of the reader’s attention by summarizing taxonomic history, favored food plants, and environmental issues concerning bumblebees.

  19. Status of RNB facilities in North America

    CERN Document Server

    Nolen, J A

    1998-01-01

    This paper presents the status of accelerator facilities in North America that are involved in research using radioactive nuclear beams (RNB), including existing and operating facilities, ones currently under construction or undergoing major upgrades, and ones being planned or proposed for the future. Existing RNB facilities are located at TRIUMF (TISOL) in Vancouver, B.C., the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory, the Argonne Tandem Linear Accelerator System (ATLAS) at Argonne National Laboratory, the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University, the Nuclear Structure Laboratory at the University of Notre Dame, the 88" Cyclotron at Lawrence Berkeley National Laboratory, and the Cyclotron Institute at Texas A&M University. Currently, there are two major RNB facility upgrades in progress in North America, one at TRIUMF, the ISAC project, and one at NSCL, the Intensity Upgrade project. For the future, the U.S. Nuclear Science A...

  20. Regional Military Security Cooperation in North America

    Science.gov (United States)

    2009-12-11

    North America, Europe, Russia, Japan, South Korea, China, India , Australia, New Zealand, South Africa, Argentina, Brazil, and Chile.24 The Non...Sea.47 Additionally, he sees competition and conflict over water arising in the river basins of the Nile, Jordon, Tigris, and Euphrates rivers . This... interlinks with oil competition, as it is the same geographic region.48 Finally, he views Africa as an additional hot spot as there are many

  1. First record of giant anteater (xenarthra, myrmecophagidae) in north america.

    Science.gov (United States)

    Shaw, C A; McDonald, H G

    1987-04-10

    A right metacarpal III represents the first North American record of the giant anteater (Myrmecophaga tridactyla). Recovered in northwestern Sonora, Mexico, with a rich vertebrate fauna of early Pleistocene (Irvingtonian) age, it belongs to a cohort of large mammals that dispersed from South America to North America along a savanna corridor. Presumably habitat and climatic changes have subsequently driven this mammalian family more than 3000 kilometers back into Central America from its former expansion into temperate North America.

  2. Fostering renewable electricity markets in North America

    International Nuclear Information System (INIS)

    Wingate, M.; Hamrin, J.; Kvale, L.; Alatorre, C.

    2007-04-01

    This paper provided an overview of key market demand and supply drivers for the renewable electricity in Canada, the United States and Mexico. The aim of the paper was to assist North American governments in supporting the development of renewable electricity by addressing barriers that currently contribute to higher costs as well as challenges related to policy implementation. The paper outlined regulatory mandates and discussed issues related to voluntary purchases, and financial incentives. Current policy frameworks for renewable electricity were also examined. Opportunities for developing the renewable electricity market North America were explored. Wind power environmental standards were reviewed. Various green pricing schemes were discussed. The paper also included recommendations for the current electricity market as well as for members of the North American Agreement on Environmental Cooperation. 84 refs., 4 tabs., 7 figs

  3. North America and Asia Pacific LNG markets

    International Nuclear Information System (INIS)

    Pirie, J.D.

    1997-01-01

    The liquefied natural gas (LNG) export opportunities in the Asia Pacific market were reviewed. Some of the differences that affect a North American LNG projects compared to more typical LNG projects were also outlined. The two main aspects of the LNG market in North America include the establishment of LNG import terminals on the east and southern coasts of the United States and the development of export oriented LNG projects. The Pac-Rim LNG project calls for initial delivery to South Korea of 4.0 MTPA by the end of 2000. A large LNG project has also been proposed for the year 2005 which would use Prudhoe Bay gas. Generally, in North America, there is little use for large scale LNG import projects because of the vast pipeline network that delivers gas reliably and at low cost anywhere in North America. However, LNG remains a good alternative for the Asia Pacific region because of the lack of a pipeline network. Also, Japan, Korea and Taiwan, the three main centers for LNG demand, have no domestic energy supplies and rely on imported energy sources. China is another major market opportunity for LNG. The Pac-Rim LNG project differs from others of its kind in that usually, an LNG project is based on the availability of large reservoirs of natural gas owned by state governments and involves production agreements with multi-national oil and gas companies. This scenario is simply not possible in Canada's deregulated environment. In contrast, the existence of upstream facilities, technical expertise, and low capital costs, hence reduced risks and time to develop an LNG project, gives Canada significant advantages. 3 tabs., 3 figs

  4. Fostering renewable energy markets in North America

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Jeremy [North American Comission for Environmental Cooperation (CEC), (United States)

    2007-06-15

    This presentation describes projects, programs and other issues addressed in order to promote renewable energy markets in North America. These are carried out by the North American Commission for Environmental Cooperation (CEC). In the first part of this presentation, there are going to be found some of the rules imposed by the North American Agreement on Environmental Cooperation (NAAEC). Then, it is shown the structure of the CEC as well as its programs, besides, there are presented the environment projects and the objectives along with their respective trades. There are described both benefits environmental and non-environmental. Also, there are shown the issues which the CEC is working in. And finally, it is shown a list mentioning the aspects that would change if: the expansion of the Mexico's Federal Commission of Electricity (CFE), happens, the grid-interconnected and the self supply of Renewable Electricity increase. [Spanish] En esta presentacion se describen los proyectos, los programas y otras cuestiones, cuyo objetivo es impulsar los mercados de energia renovable en America del Norte, realizadas por la North American Commission for Environmental Cooperation. En la primera parte, se encuentran algunas de las reglas impuestas por el Acuerdo de Cooperacion Ambiental de America del Norte (ACAAN). Enseguida, se muestra la estructura y los programas de la Comision para la Cooperacion Ambiental (CCA). Asimismo, se describen los proyectos ambientales, los objetivos junto con sus correspondientes tratados. Mas adelante, se explican tanto los beneficios ambientales como aquellos que no lo son. Igualmente, explican las cuestiones que podrian cambiar de: suceder la expansion de la Comision Federal de Electricidad (CFE), incrementarse el auto- suministro de la energia renovable y los sistemas interconectados.

  5. The thrust belts of Western North America

    Energy Technology Data Exchange (ETDEWEB)

    Moulton, F.C.

    1993-08-01

    Most of the Basin and Range physiographic province of western North America is now believed to be part of the overthrust. The more obvious overthrust belt along the eastern edge of the Basin and Range Province is named the Sevier orogenic belt, where older rocks are observed thrust onto younger rocks. More detailed surface geological mapping, plus deep multiple-fold geophysical work and many oil and gas wildcat wells, have confirmed an east-vergent shortened and stacked sequence is present in many places in the Basin and Range. This western compressive deformed area in east central Nevada is now named the Elko orogenic belt by the U.S. Geological Survey. This older compressed Elko orogenic belt started forming approximately 250 m.y. ago when the North American plate started to move west as the Pangaea supercontinent started to fragment. The North American plate moved west under the sediments of the Miogeocline that were also moving west. Surface-formed highlands and oceanic island arcs on the west edge of the North American plate restricted the westward movement of the sediments in the Miogeocline, causing east-vergent ramp thrusts to form above the westward-moving North American plate. The flat, eastward-up-cutting thrust assemblages moved on the detachment surfaces.

  6. 78 FR 2287 - Daimler Buses North America, Inc., a Subsidiary of Daimler North America Corp, Including On-Site...

    Science.gov (United States)

    2013-01-10

    ... subsidiary of Daimler North America Corp., including on-site leased workers from Noramtec, First Choice... America, Inc., a Subsidiary of Daimler North America Corp, Including On-Site Leased Workers From Noramtec, First Choice Staffing, Staff Works, and Mr. Santo Lamarco From Wurth Revcar Fasteners, Inc., Oriskany...

  7. The bentonite industry in North America

    International Nuclear Information System (INIS)

    Dixon, D.A.; Hnatiw, D.S.J.; Walker, B.T.

    1992-11-01

    The Canadian Nuclear Fuel Waste Management Program is studying a concept for the disposal of nuclear fuel waste at a depth of 500 to 1000 m below the surface in stable crystalline rock of the Canadian Shield. The waste containers would be surrounded by a clay-based buffer material, composed of equal proportions of bentonite clay and silica sand. In the reference disposal concept, some 1.9 x 10 5 Mg of used fuel would be emplaced. This would require 2.5 x 10 6 Mg of bentonite. A review of the bentonite industry in North America was carried out to establish the availability of sufficient high-quality material. There are proven reserves of sodium bentonite clay in excess of 1.5 x 10 8 Mg, and vast supplies are known to exist but not yet proven. The Canadian conceptual disposal vault would require 6 x 10 4 Mg of sodium bentonite each year for 40 years. The bentonite industry of North America has an installed annual production capacity of 2 x 10 7 Mg. A disposal vault would therefore require approximately 2% of the industry capacity. A number of commercial products have been screened for potential suitability for use as a component of the buffer. Ten currently marketed bentonite products have been identified as meeting the initial quality standards for the buffer, and two non-commercial bentonites have been identified as having the potential for use in a disposal vault. (Author) (14 figs., 7 tabs., 18 refs.)

  8. Toxocariasis in North America: a systematic review.

    Directory of Open Access Journals (Sweden)

    Rachel M Lee

    2014-08-01

    Full Text Available Toxocariasis is an important neglected tropical disease that can manifest as visceral or ocular larva migrans, or covert toxocariasis. All three forms pose a public health problem and cause significant morbidity in areas of high prevalence. To determine the burden of toxocariasis in North America, we conducted a systematic review of the literature following PRISMA guidelines. We found 18 articles with original prevalence, incidence, or case data for toxocariasis. Prevalence estimates ranged from 0.6% in a Canadian Inuit community to 30.8% in Mexican children with asthma. Commonly cited risk factors included: African-American race, poverty, male sex, and pet ownership or environmental contamination by animal feces. Increased prevalence of Toxocara spp. infection was linked in a group of case control studies conducted in Mexico to several high risk groups including waste pickers, asthmatic children, and inpatient psychiatry patients. Further research is needed to determine the true current burden of toxocariasis in North America; however the prevalence estimates gathered in this review suggest that the burden of disease is significant.

  9. Estimation of gas reserves in North America

    International Nuclear Information System (INIS)

    Laherrere, J.

    2001-01-01

    If the oil market is global, the gas market is divided into three zones: North America, Europe and Asia. The official forecast of the future demand of North America gas is optimist as it is based on estimates of resources which are ten times those of the proved reserves. The poor practice (SEC rules) of proved reserves (when the rest of the world uses proven+probable) leads to a constant revision and a growth of the past discoveries, showing well a wrong evaluation. The official databases are then very poor, even those of the US federal domain, which have to be public. The study of the technical data of reserves of US, Canada and Mexico leads to a more pessimistic estimation of the ultimate reserves and then to the future local supply. In the Gulf of Mexico (the main hope), the production of natural gas in shallow water decline and the discoveries in the deep-water are mainly oil. The non-conventional gas seems to level. But the future demand is also too optimistic, based on cheap price and on a steady growth. However the local gas supply will be likely insufficient, and the demand will need imported liquefied natural gas. (author)

  10. Violence against women in North America.

    Science.gov (United States)

    Erlick Robinson, G

    2003-08-01

    Although North America is viewed as a place where women have equal rights and status, violence against women is still rampant. Forty to 51% of women experience some type of violence in their lifetime including child abuse, physical violence, rape and domestic violence. The perpetrator is most likely to be a current or former partner. Such violence stems from historical views of women as property and may flourish because of the public's reluctance to get involved in family matters. The concept of violence has been expanded to include non-traditional types such as sexual harassment, breeches of fiduciary trust and stalking. Treatment of victims of violence must include ensuring their safety, encouraging them to make healthy choices and helping them to understand they are not at fault. Education at all levels is required to change attitudes which perpetuate violence despite laws which forbid it.

  11. A hierarchical classification of freshwater mussel diversity in North America

    Science.gov (United States)

    Wendell R. Haag

    2010-01-01

    Aim North America harbours the most diverse freshwater mussel fauna on Earth. This fauna has high endemism at the continental scale and within individual river systems. Previous faunal classifications for North America were based on intuitive, subjective assessments of species distributions, primarily the occurrence of endemic species, and do not portray continent-wide...

  12. Snow cover and temperature relationships in North America and Eurasia

    Science.gov (United States)

    Foster, J.; Owe, M.; Rango, A.

    1983-01-01

    In this study the snow cover extent during the autumn months in both North America and Eurasia has been related to the ensuing winter temperature as measured at several locations near the center of each continent. The relationship between autumn snow cover and the ensuing winter temperatures was found to be much better for Eurasia than for North America. For Eurasia the average snow cover extent during the autumn explained as much as 52 percent of the variance in the winter (December-February) temperatures compared to only 12 percent for North America. However, when the average winter snow cover was correlated with the average winter temperature it was found that the relationship was better for North America than for Eurasia. As much as 46 percent of the variance in the winter temperature was explained by the winter snow cover in North America compared to only 12 percent in Eurasia.

  13. Browning boreal forests of western North America

    Science.gov (United States)

    Verbyla, David

    2011-12-01

    The GIMMS NDVI dataset has been widely used to document a 'browning trend' in North American boreal forests (Goetz et al 2005, Bunn et al 2007, Beck and Goetz 2011). However, there has been speculation (Alcaraz-Segura et al 2010) that this trend may be an artifact due to processing algorithms rather than an actual decline in vegetation activity. This conclusion was based primarily on the fact that GIMMS NDVI did not capture NDVI recovery within most burned areas in boreal Canada, while another dataset consistently showed post-fire increasing NDVI. I believe that the results of Alcaraz-Segura et al (2010) were due simply to different pixel sizes of the two datasets (64 km2 versus 1 km2 pixels). Similar results have been obtained from tundra areas greening in Alaska, with the results simply due to these pixel size differences (Stow et al 2007). Furthermore, recent studies have documented boreal browning trends based on NDVI from other sensors. Beck and Goetz (2011) have shown the boreal browning trend derived from a different sensor (MODIS) to be very similar to the boreal browning trend derived from the GIMMS NDVI dataset for the circumpolar boreal region. Parent and Verbyla (2010) found similar declining NDVI patterns based on NDVI from Landsat sensors and GIMMS NDVI in boreal Alaska. Zhang et al (2008) found a similar 'browning trend' in boreal North America based on a production efficiency model using an integrated AVHRR and MODIS dataset. The declining NDVI trend in areas of boreal North America is consistent with tree-ring studies (D'Arrigo et al 2004, McGuire et al 2010, Beck et al 2011). The decline in tree growth may be due to temperature-induced drought stress (Barber et al 2000) caused by higher evaporative demands in a warming climate (Lloyd and Fastie 2002). In a circumpolar boreal study, Lloyd and Bunn (2007) found that a negative relationship between temperature and tree-ring growth occurred more frequently in warmer parts of species' ranges

  14. Endemism in the moss flora of North America.

    Science.gov (United States)

    Carter, Benjamin E; Shaw, Blanka; Shaw, A Jonathan

    2016-04-01

    Identifying regions of high endemism is a critical step toward understanding the mechanisms underlying diversification and establishing conservation priorities. Here, we identified regions of high moss endemism across North America. We also identified lineages that contribute disproportionately to endemism and document the progress of efforts to inventory the endemic flora. To understand the documentation of endemic moss diversity in North America, we tabulated species publication dates to document the progress of species discovery across the continent. We analyzed herbarium specimen data and distribution data from the Flora of North America project to delineate major regions of moss endemism. Finally, we surveyed the literature to assess the importance of intercontinental vs. within-continent diversification for generating endemic species. Three primary regions of endemism were identified and two of these were further divided into a total of nine subregions. Overall endemic richness has two peaks, one in northern California and the Pacific Northwest, and the other in the southern Appalachians. Description of new endemic species has risen steeply over the last few decades, especially in western North America. Among the few studies documenting sister species relationships of endemics, recent diversification appears to have played a larger role in western North America, than in the east. Our understanding of bryophyte endemism continues to grow rapidly. Large continent-wide data sets confirm early views on hotspots of endemic bryophyte richness and indicate a high rate of ongoing species discovery in North America. © 2016 Botanical Society of America.

  15. A detailed gravimetric geoid of North America, the North Atlantic, Eurasia, and Australia

    Science.gov (United States)

    Marsh, J. G.

    1973-01-01

    A computer program was developed for the calculation of a goid based upon a combination of satellite and surface gravity data. A detailed gravimetric geoid of North America, the North Atlantic, Eurasia, and Australia was derived by using this program.

  16. A new era for uranium mining in North America

    International Nuclear Information System (INIS)

    Poissonet, M.; Marvy, A.

    1997-01-01

    North America will be one of the few places in the world where continuous development of new uranium mining projects and renewed, more intense exploration will occur for the coming years. Although the present project approval process and regulatory regime can be seen as a burden, past discoveries of world-class deposits have made North America the best place to invest in uranium production for many years to come. (author) 1 fig

  17. Tectonic history of the southeastern North America

    Energy Technology Data Exchange (ETDEWEB)

    Hatcher, R.D. Jr. (Univ. of Tennessee, Knoxville, TN (United States). Dept. of Geological Sciences Oak Ridge National Lab., TN (United States))

    1993-03-01

    The present-day configuration of the crust of southeastern North America (SENA) is the product of a lengthy history traceable through more than 1 billion yr. of geologic time. The Appalachians (AP) record complete Wilson cycles of opening and closing of several oceans from ca. 690 Ma to 245 M. The final event forming the AP was the collision of SENA with Gondwana to form the supercontinent Pangaea. The Ouachitas (OA) had a somewhat different history culminating with island-arc collision during the Pennsylvanian--before the final collision began in the AP. SENA faced the open lapetos ocean no earlier than the Early Cambrian. The AP and OA were built on an earlier margin formed by rifting of the Rodonia super-continent formed by construction of the 1.2 to 1.0 Ga Grenville orogen, and farther west, a crust formed by still earlier (1.3 and 1.8 Ga) events. Recent suggestions that part of the AP platform is in Argentina raises the possibility that a fragment was rifted from between the AP and OA during the early Paleozoic. The crust beneath the Mississippi Embayment is atypical of continental crust, and would have been rifted during the Neoproterozoic and early Paleozoic. The Argentine fragment may have been removed along a transform that was reactivated several times since. Northern Pangaea was rifted during the Late Triassic and Early Jurassic and SENA once again faced open ocean-the nascent present Atlantic (AT) when spreading began. The Gulf of Mexico (GOM) also opened then forming extensive salt deposits. The AT opened partly along the old suture, but produced a failed rift in GA and FL leaving a piece of Africa forming the crust beneath the Coastal Plain as far south as central FL. The overlying sediments record recurrent uplift and decay of the AP and OA, cooling of new AT oceanic crust, eustatic sea-level changes during the Mesozoic and Cenozoic, and uplift of the Rockies providing a new source of voluminous detritus that is still being deposited in the GOM.

  18. Population structures of Astragalus filipes collections from western North America

    Science.gov (United States)

    B. Shaun Bushman; Kishor Bhattarai; Douglas A. Johnson

    2010-01-01

    The majority of species used for revegetation in semi-arid western rangelands of North America are grasses, with few forbs and nearly no legumes. Astragalus filipes (Torr. Ex A. Gray) is a western North American legume and a promising candidate for use in rangeland revegetation, but assessments of plant species diversity and structure are necessary to determine which...

  19. Adult Education Faculty and Programs in North America

    Science.gov (United States)

    Tisdell, Elizabeth J.; Wright, Robin Redmon; Taylor, Edward W.

    2016-01-01

    This article reports on the findings of a quantitative survey of North American adult education faculty and a textual analysis of websites of adult education graduate programs in North America conducted in the fall of 2013. This study examined background information about adult education faculty and programs; the nature of faculty work interests,…

  20. The Development of improved willow clones for eastern North America

    Science.gov (United States)

    R. F. Kopp; L. B. Smart; C. A. Maynard; J. G. Isebrands; G. A. Tuskan; L. P. Abrahamson

    2001-01-01

    Efforts aimed at genetic improvement of Salix are increasing in North America.Most of these are directed towards developing improved clones for biomass production, phytoremediation, nutrient filters, and stream bank stabilization in the Northeast and North-central United States. Native species are of primary interest, but a small number of clones containing non-native...

  1. Catalogue of Tenebrionidae (Coleoptera of North America

    Directory of Open Access Journals (Sweden)

    Yves Bousquet

    2018-01-01

    Full Text Available This catalogue includes all valid family-group (8 subfamilies, 52 tribes, 14 subtribes, genus-group (349 genera, 86 subgenera, and species-group names (2825 species, 215 subspecies of darkling beetles (Coleoptera: Tenebrionidae known to occur in North America1 and their available synonyms. Data on extant, subfossil and fossil taxa are given. For each name the author and year and page number of the description are provided, with additional information (e.g., type species for genus-group names, author of synonymies for invalid taxa depending on the taxon rank. Several new nomenclatural acts are included. One new genus, Lepidocnemeplatia Bousquet and Bouchard, is described. Spelaebiosis Bousquet and Bouchard [for Ardoinia Özdikmen, 2004], Blapstinus marcuzzii Aalbu [for Blapstinus kulzeri Marcuzzi, 1977], and Hymenorus campbelli Bouchard [for Hymenorus oculatus Doyen and Poinar, 1994] are proposed as new replacement names. Supporting evidence is provided for the conservation of usage of Tarpela micans (Fabricius, 1798 nomen protectum over Tarpela vittata (Olivier, 1793 nomen oblitum. The generic names Psilomera Motschulsky, 1870 [= Stenomorpha Solier, 1836], Steneleodes Blaisdell, 1909 [= Xysta Eschscholtz, 1829], Ooconibius Casey, 1895 and Euconibius Casey, 1895 [= Conibius LeConte, 1851] are new synonyms (valid names in square brackets. The following 127 new synonymies of species-group names, listed in their original combination, are proposed (valid names, in their current combination, placed in square brackets: Bothrasida mucorea Wilke, 1922 [= Pelecyphorus guanajuatensis (Champion, 1884]; Parasida zacualpanicola Wilke, 1922 [= Pelecyphorus asidoides Solier, 1836]; Stenosides kulzeri Pallister, 1954, Stenosides bisinuatus Pallister, 1954, and Parasida trisinuata Pallister, 1954 [= Pelecyphorus dispar (Champion, 1892]; Asida favosa Champion, 1884 and Asida similata Champion, 1884 [= Pelecyphorus fallax (Champion, 1884]; Ologlyptus bicarinatus

  2. A New Eocene Casquehead Lizard (Reptilia, Corytophanidae from North America.

    Directory of Open Access Journals (Sweden)

    Jack L Conrad

    Full Text Available A new fossil showing affinities with extant Laemanctus offers the first clear evidence for a casquehead lizard (Corytophanidae from the Eocene of North America. Along with Geiseltaliellus from roughly coeval rocks in central Europe, the new find further documents the tropical fauna present during greenhouse conditions in the northern mid-latitudes approximately 50 million years ago (Ma. Modern Corytophanidae is a neotropical clade of iguanian lizards ranging from southern Mexico to northern South America.

  3. Hydrogeology in North America: past and future

    Science.gov (United States)

    Narasimhan, T. N.

    2005-03-01

    This paper is a retrospective on the evolution of hydrogeology in North America over the past two centuries, and a brief speculation of its future. The history of hydrogeology is marked by developments in many different fields such as groundwater hydrology, soil mechanics, soil science, economic geology, petroleum engineering, structural geology, geochemistry, geophysics, marine geology, and more recently, ecology. The field has been enriched by the contributions of distinguished researchers from all these fields. At present, hydrogeology is in transition from a state of discovering new resources and exploiting them efficiently for maximum benefit, to one of judicious management of finite, interconnected resources that are vital for the sustenance of humans and other living things. The future of hydrogeology is likely to be dictated by the subtle balance with which the hydrological, erosional, and nutritional cycles function, and the decision of a technological society to either adapt to the constraints imposed by the balance, or to continue to exploit hydrogeological systems for maximum benefit. Although there is now a trend towards ecological and environmental awareness, human attitudes could change should large parts of the populated world be subjected to the stresses of droughts that last for many decades. Cet article est une rétrospective de l'évolution de l'hydrogéologie en Amérique du Nord sur les deux derniers siècles, et une brève évaluation de son futur. L'histoire de l'hydrogéologie est marquée par le développement de plusieurs techniques de terrain telles, l'hydrologie des eaux souterraines, la mécanique des sols, les sciences du sol, la géologie économique, l' ingénierie pétrolière, la géologie structurale, la géochimie, la géophysique, la géologie marine et plus récemment l'écologie. La science a été enrichie par la contribution de plusieurs chercheurs distingués, provenant de toutes ces branches. A présent, l

  4. Genetic calibration of species diversity among North America's freshwater fishes

    OpenAIRE

    April, Julien; Mayden, Richard L.; Hanner, Robert H.; Bernatchez, Louis

    2011-01-01

    Freshwater ecosystems are being heavily exploited and degraded by human activities all over the world, including in North America, where fishes and fisheries are strongly affected. Despite centuries of taxonomic inquiry, problems inherent to species identification continue to hamper the conservation of North American freshwater fishes. Indeed, nearly 10% of species diversity is thought to remain undescribed. To provide an independent calibration of taxonomic uncertainty and to establish a mor...

  5. Exploring the origins of ecological forestry in North America

    Science.gov (United States)

    Anthony W. ​D' Amato; Brian J. Palik; Jerry F. Franklin; David R. Foster

    2016-01-01

    The use of ecological forestry to achieve management objectives, such as the maintenance of native biodiversity, has become increasingly common on public and private ownerships in North America. These approaches generally use natural disturbance processes and their structural and compositional outcomes as models for designing silvicultural prescriptions that restore or...

  6. PARASITES OF FRESHWATER FISHES IN NORTH AMERICA: WHY SO NEGLECTED?

    Czech Academy of Sciences Publication Activity Database

    Scholz, Tomáš; Choudhury, A.

    2014-01-01

    Roč. 100, č. 1 (2014), s. 26-45 ISSN 0022-3395 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Trematode * North America * Cestoda * Acanthocephala * Digenea Subject RIV: EG - Zoology Impact factor: 1.227, year: 2014

  7. The interannual variability of the Haines Index over North America

    Science.gov (United States)

    Lejiang Yu; Shiyuan Zhong; Xindi Bian; Warren E. Heilman; Joseph J. Charney

    2013-01-01

    The Haines index (HI) is a fire-weather index that is widely used as an indicator of the potential for dry, low-static-stability air in the lower atmosphere to contribute to erratic fire behavior or large fire growth. This study examines the interannual variability of HI over North America and its relationship to indicators of large-scale circulation anomalies. The...

  8. Cold-water fishes and climate change in North America

    Science.gov (United States)

    J. E. Williams; Daniel Isaak; J. Imhof; D. A. Hendrickson; J. R. McMillan

    2015-01-01

    Trout, salmon, grayling and whitefishes (Salmonidae) are among the most ecologically and economically important fishes. They also are among the most vulnerable to global warming, and increasing drought, floods, and wildfires. In North America, salmonids occur from central Mexico northward along coastal regions and mountainous interiors to the Arctic Plains. A...

  9. Conservation of native Pacific trout diversity in Western North America

    Science.gov (United States)

    Brooke E. Penaluna; Alicia Abadía-Cardoso; Jason B. Dunham; Francisco J. García-Dé León; Robert E. Gresswell; Arturo Ruiz Luna; Eric B. Taylor; Bradley B. Shepard; Robert Al-Chokhachy; Clint C. Muhlfeld; Kevin R. Bestgen; Kevin Rogers; Marco A. Escalante; Ernest R. Keeley; Gabriel M. Temple; Jack E. Williams; Kathleen R. Matthews; Ron Pierce; Richard L. Mayden; Ryan P. Kovach; John Carlos Garza; Kurt D. Fausch

    2016-01-01

    Pacific trout Oncorhynchus spp. in western North America are strongly valued in ecological, socioeconomic, and cultural views, and have been the subject of substantial research and conservation efforts. Despite this, the understanding of their evolutionary histories, overall diversity, and challenges to their conservation is incomplete. We review...

  10. Bark beetle outbreaks in western North America: Causes and consequences

    Science.gov (United States)

    Bentz, Barbara; Logan, Jesse; MacMahon, James A.; Allen, Craig D.; Ayres, Matt; Berg, Edward E; Carroll, Allan; Hansen, Matt; Hicke, Jeff H.; Joyce, Linda A.; Macfarlane, Wallace; Munson, Steve; Negron, Jose; Paine, Tim; Powell, Jim; Raffa, Kenneth; Regniere, Jacques; Reid, Mary; Romme, Bill; Seybold, Steven J.; Six, Diana; Vandygriff, Jim; Veblen, Tom; White, Mike; Witcosky, Jeff; Wood, David J. A.

    2005-01-01

    Since 1990, native bark beetles have killed billions of trees across millions of acres of forest from Alaska to northern Mexico. Although bark beetle infestations are a regular force of natural change in forested ecosystems, several of the current outbreaks, which are occurring simultaneously across western North America, are the largest and most severe in recorded history.

  11. An Overview of CLT Research and Implementation in North America

    Science.gov (United States)

    Shiling Pei; Douglas Rammer; Marjan Popovski; Tom Williamson; Philip Line; John W. van de Lindt

    2016-01-01

    Although not yet seen as common practice, building with cross laminated timber (CLT) is gaining momentum in North America. Behind the scenes of the widely publicized project initiatives such as the Wood Innovation Design Centre Building in Canada and the recent U.S. Tall Wood Building Competition, substantial research, engineering, and development has been completed or...

  12. Academic Talent Development in North America and Europe

    Science.gov (United States)

    Jarvin, Linda; Subotnik, Rena F.

    2015-01-01

    First we describe one particular model of talent development (Jarvin and Subotnik in The handbook of secondary gifted education. Prufrock Press, Waco, 2006) and situate it in perspective to other models developed in North America and Europe. We then discuss the implications of this view of giftedness on education and review related resources and…

  13. The Dorstenia species (Moraceae) of north-western tropical America

    NARCIS (Netherlands)

    Berg, C.C.; Leeuwen, van R.W.J.

    1982-01-01

    Four new species of Dorstenia are described: D. panamensis C.C. Berg, D. boliviana C.C. Berg, D. peruviana C.C. Berg, and D. belizensis C.C. Berg. A list of and a key to the 21 Dorstenia species distinguished in north-western tropical America are presented, together with synonyms and distributions.

  14. The medicinal use of chocolate in early North America.

    Science.gov (United States)

    Pucciarelli, Deanna L; Grivetti, Louis E

    2008-10-01

    The medicinal use of chocolate has a long history in North America dating back to the 16th century. From Mesoamerican Codices and European Treatises scholars have determined that for hundreds of years the beverage called chocolate was administered to the sick and prescribed homeopathically to prevent illness. Yet, little scholarship exists that focuses on medicinal chocolate usage in early North America (18th-19th century). This paper examines medical practices during this era and associated medicinal norms with special attention given to chocolate/cocoa usage. Given the current scientific attention on the relationship between dark chocolate consumption and heart disease attenuation it is timely to investigate and chronicle America's medical forebears' understanding of, and practices related to, the medicinal use of chocolate. Indeed, there is a significant amount of literature to suggest that chocolate was used for wellness and to treat illness.

  15. Is the Central America forearc sliver part of the North America plate?

    Science.gov (United States)

    Guzman-Speziale, M.

    2012-04-01

    The Central America Forearc sliver is located between the Central America volcanic arc and the Middle America trench. Several authors have suggested that the forearc is being displaced to the northwest with respect to the Caribbean plate; they point to right-lateral, normal-faulting earthquakes along the Central America volcanic arc as prime evidence of this displacement. Apparently, the forearc continues to the northwest into southeastern Mexico, although this portion of the forearc is not being displaced. I present evidence that suggests that the forearc indeed continues into southeastern Mexico and that it belongs to the North America plate. Physiographically, there is a continuity of the forearc into the Coastal plains of southeastern (Chiapas) Mexico, across the Motagua and Polochic faults. Offshore, cross-sections of the Middle America trench are similar along the mexican (Chiapas) segment, and the Central American segment. Furthermore, at the northwestern end of the coastal plain there are no compressive structures, which suggests that the coastal plain is not being displaced to the northwest. As a matter of fact, fault-plane solutions for shallow earthquakes show extension rather than compression. Shallow, interplate earthquakes along the trench show similar parameters along both segments. P-axes and earthquake slip vectors have consistent azimuths, which relate better with Cocos-North America convergence than with Cocos-Caribbean. Azimuth of T-axes for normal-faulting earthquakes also agree well with Cocos-North America convergence. Similarity in several parameters is thus found across both segments, the Chiapas coastal plain and the Central America forearc sliver proper. This suggests that both segments are continuous and probably one and the same, and belonging to the North America plate. Perhaps more properly, the forearc sliver extends into southeastern Mexico and is part of the zone of deformation associated to the Cocos-North America-Caribbean plates

  16. Invasion by a Japanese marine microorganism in western North America

    Science.gov (United States)

    McGann, M.; Sloan, D.; Cohen, A.N.

    2000-01-01

    The earliest record in western North America of Trochammina hadai Uchio, a benthic foraminifer common in Japanese estuaries, is from sediment collected in Puget Sound in 1971. It was first found in San Francisco Bay in sediment samples taken in 1983, and since 1986 has been collected at 91% of the sampled sites in the Bay, constituting up to 93% of the foraminiferal assemblage at individual sites. The species is also present in recent sediment samples from 12 other sites along the west coast of North America. The evidence indicates that T. hadai is a recent introduction to San Francisco Bay, and is probably also not native to the other North American sites. Trochammina hadai was probably transported from Japan in ships' ballast tanks, in mud associated with anchors, or in sediments associated with oysters imported for mariculture. Its remarkable invasion of San Francisco Bay suggests the potential for massive, rapid invasions by other marine microorganisms.

  17. A detailed gravimetric geoid from North America to Eurasia

    Science.gov (United States)

    Vincent, S. F.; Strange, W. E.; Marsh, J. G.

    1972-01-01

    A detailed gravimetric geoid of the United States, North Atlantic, and Eurasia, which was computed from a combination of satellite derived and surface gravity data, is presented. The precision of this detailed geoid is + or - 2 to + or - 3 m in the continents but may be in the range of 5 to 7 m in those areas where data is sparse. Comparisons of the detailed gravimetric geoid with results of Rapp, Fischer, and Rice for the United States, Bomford in Europe, and Heiskanen and Fischer in India are presented. Comparisons are also presented with geoid heights from satellite solutions for geocentric station coordinates in North America, the Caribbean, and Europe.

  18. Natural gas pricing and contracting practices in North America

    International Nuclear Information System (INIS)

    Hassan, F.

    1992-01-01

    Over the past 5 years the natural gas industry in North America has undergone substantial change as a result of the deregulated market. A comparison is provided of the key contract parameters in gas purchase contracts utilized by local distribution companies, industrial customers, cogenerators and marketers. Issues discussed include pricing mechanisms, indexed contracts, negotiated contracts, combinations, dispute resolution, supply, government regulation, industry structures, financial considerations, perception, geological influences, demand, transmission, storage, distribution, price trends and forecasts, Order 636 in the U.S., the evolution of North American market hubs, the futures market, and 'daisy chains' of connecting pipelines. 15 refs., 7 figs., 1 tab

  19. A Bayesian modelling framework for tornado occurrences in North America.

    Science.gov (United States)

    Cheng, Vincent Y S; Arhonditsis, George B; Sills, David M L; Gough, William A; Auld, Heather

    2015-03-25

    Tornadoes represent one of nature's most hazardous phenomena that have been responsible for significant destruction and devastating fatalities. Here we present a Bayesian modelling approach for elucidating the spatiotemporal patterns of tornado activity in North America. Our analysis shows a significant increase in the Canadian Prairies and the Northern Great Plains during the summer, indicating a clear transition of tornado activity from the United States to Canada. The linkage between monthly-averaged atmospheric variables and likelihood of tornado events is characterized by distinct seasonality; the convective available potential energy is the predominant factor in the summer; vertical wind shear appears to have a strong signature primarily in the winter and secondarily in the summer; and storm relative environmental helicity is most influential in the spring. The present probabilistic mapping can be used to draw inference on the likelihood of tornado occurrence in any location in North America within a selected time period of the year.

  20. Rapid Passenger Transport in North America in 21st Century

    Directory of Open Access Journals (Sweden)

    Wolf Tietze

    2012-10-01

    Full Text Available The occurrence of outstanding transport innovations maylead to monumental reconstruction in large urbanised regionssuch as North America. The decisive factor in this is the introductionofTransrapid, a new rapid transport technology basedon the principle of magnetic levitation (Maglev.This paper uses the urban network of North America Eastof the 1 O(Jh meridian, together with the smaller region of California,to demonstrate the advantages of innovative transporttechnology as the optimal link between road and air transport.Despite requiring less energy input, achieving better adaptationto the topography of the country, causing less noise and beingsubject to less wear and tear, Transrapid achieves almost twicethe speed of conventional trains.

  1. Electron beam curing of composites in North America

    International Nuclear Information System (INIS)

    Berejka, Anthony J.; Eberle, Cliff

    2002-01-01

    Electron beam curing of fiber-reinforced composites was explored over 30 years ago. Since then there have been developments in accelerator technology, in processes for handling materials presented to an accelerator, and in materials that can be used as matrix binders. In recent years in North America, Cooperative Research and Development Agreements (CRADAs) have been formed involving collaboration amongst materials suppliers, accelerator manufacturers and service providers, national laboratories, such as Oak Ridge National Laboratory, and interested potential users. The scope and status of these CRADAs are reviewed along with other recent developments in the electron beam curing of composites in North America. Innovative and proprietary materials technology has been developed and progress made toward implementing commercial practice. Significant market interest has developed in the military/aerospace industries that are finding the process and performance of electron beam cured composites to offer significant benefits

  2. Glaciers of North America - Glaciers of Alaska

    Science.gov (United States)

    Molnia, Bruce F.

    2008-01-01

    Glaciers cover about 75,000 km2 of Alaska, about 5 percent of the State. The glaciers are situated on 11 mountain ranges, 1 large island, an island chain, and 1 archipelago and range in elevation from more than 6,000 m to below sea level. Alaska's glaciers extend geographically from the far southeast at lat 55 deg 19'N., long 130 deg 05'W., about 100 kilometers east of Ketchikan, to the far southwest at Kiska Island at lat 52 deg 05'N., long 177 deg 35'E., in the Aleutian Islands, and as far north as lat 69 deg 20'N., long 143 deg 45'W., in the Brooks Range. During the 'Little Ice Age', Alaska's glaciers expanded significantly. The total area and volume of glaciers in Alaska continue to decrease, as they have been doing since the 18th century. Of the 153 1:250,000-scale topographic maps that cover the State of Alaska, 63 sheets show glaciers. Although the number of extant glaciers has never been systematically counted and is thus unknown, the total probably is greater than 100,000. Only about 600 glaciers (about 1 percent) have been officially named by the U.S. Board on Geographic Names (BGN). There are about 60 active and former tidewater glaciers in Alaska. Within the glacierized mountain ranges of southeastern Alaska and western Canada, 205 glaciers (75 percent in Alaska) have a history of surging. In the same region, at least 53 present and 7 former large ice-dammed lakes have produced jokulhlaups (glacier-outburst floods). Ice-capped volcanoes on mainland Alaska and in the Aleutian Islands have a potential for jokulhlaups caused by subglacier volcanic and geothermal activity. Because of the size of the area covered by glaciers and the lack of large-scale maps of the glacierized areas, satellite imagery and other satellite remote-sensing data are the only practical means of monitoring regional changes in the area and volume of Alaska's glaciers in response to short- and long-term changes in the maritime and continental climates of the State. A review of the

  3. Applications and development of CAMAC in North America in 1975

    International Nuclear Information System (INIS)

    Mack, D.A.; Wagner, L.J.

    1975-01-01

    CAMAC is now a well established instrumentation system in North America. Research organizations outside of the National Laboratories and industrial users are finding that this modular instrumentation system for data handling is indeed a very practical and cost effective approach to Computer Aided Measurement and Control. Accordingly, this paper reviews applications of new developments in CAMAC during the past year and considers its future in view of related technological developments. (U.S.)

  4. US of tissue banking and transplantation in North America

    International Nuclear Information System (INIS)

    Strong, M.; Moogk, M.

    1999-01-01

    Tissue banking in North America began as surgical bone banking in individual hospitals and progressed to recovery of cadaveric tissues, initially by the United States Navy Tissue Bank and more recently to regional tissue banks throughout North America. The American Association of Tissue Banks was established in 1976 to develop standards for tissue banking and the eventual inspection and accreditation of tissue banks. The gathering of statistics of tissue banking practices was first undertaken in 1992, from accredited tissue banks. The most recent statistics were compiled in 1997 and will be reported at this conference.There are currently 63 accredited tissue banks in North America, 60 in the United States and three in Canada. Overall, tissue donation has increased by 48% during this 5 year reporting time. During the same period, the number of living surgical bone donors has decreased from nearly 3,000 to less than 500. This impact is largely due to the new regulations that have been implemented by the Food and Drug Administration (FDA). There were over 340,000 bone grafts distributed in 1996, an increase of 20% over 1992, 33% were not sterilized, 21% were sterilized using irradiation, and 45% were demineralized. Only 1% were processed using ethylene oxide as a sterilant, a decrease from 15% in 1992. The primary mode of preservation and storage is freeze-drying with 90% of the tissues falling into this category and the rest being frozen. The second largest number of grafts distributed were skin grafts. Total tissue grafts distributed including cornea was 445,417. In January 1998, the FDA Final Rule regarding regulation of tissue banking became effective. The elements of that Final Rule and new tissue banking rules the FDA has proposed will be discussed along with regulations recently published by the Health and Human Services Department relative to organ and tissue donor referrals. Tissue Banking in North America continues to evolve and has become more and more

  5. Germanic heritage languages in North America: Acquisition, attrition and change

    OpenAIRE

    Johannessen, Janne Bondi; Salmons, Joseph C.; Westergaard, Marit; Anderssen, Merete; Arnbjörnsdóttir, Birna; Allen, Brent; Pierce, Marc; Boas, Hans C.; Roesch, Karen; Brown, Joshua R.; Putnam, Michael; Åfarli, Tor A.; Newman, Zelda Kahan; Annear, Lucas; Speth, Kristin

    2015-01-01

    This book presents new empirical findings about Germanic heritage varieties spoken in North America: Dutch, German, Pennsylvania Dutch, Icelandic, Norwegian, Swedish, West Frisian and Yiddish, and varieties of English spoken both by heritage speakers and in communities after language shift. The volume focuses on three critical issues underlying the notion of ‘heritage language’: acquisition, attrition and change. The book offers theoretically-informed discussions of heritage language processe...

  6. Best strategy through Marketing Alliances for Switzerland Tourism North America

    OpenAIRE

    Bourquin, Charlotte; Holleran, James

    2014-01-01

    Having partnerships with Marketing Alliances has been proved to be an effective way for Switzerland Tourism North America to push the Destination promotion and sales as well as increase the awareness of Switzerland with the network. The two existing partnerships are with Virtuoso and Signature Travel Network, both luxury/leisure focused companies. Particularly successful results have been observed with Virtuoso. The process of choosing the right partnership has to be carefully defined ...

  7. Coherent changes of wintertime surface air temperatures over North Asia and North America.

    Science.gov (United States)

    Yu, Bin; Lin, Hai

    2018-03-29

    The surface temperature variance and its potential change with global warming are most prominent in winter over Northern Hemisphere mid-high latitudes. Consistent wintertime surface temperature variability has been observed over large areas in Eurasia and North America on a broad range of time scales. However, it remains a challenge to quantify where and how the coherent change of temperature anomalies occur over the two continents. Here we demonstrate the coherent change of wintertime surface temperature anomalies over North Asia and the central-eastern parts of North America for the period from 1951 to 2015. This is supported by the results from the empirical orthogonal function analysis of surface temperature and temperature trend anomalies over the Northern Hemisphere extratropical lands and the timeseries analysis of the regional averaged temperature anomalies over North Asia and the Great Plains and Great Lakes. The Asian-Bering-North American (ABNA) teleconnection provides a pathway to connect the regional temperature anomalies over the two continents. The ABNA is also responsible for the decadal variation of the temperature relationship between North Asia and North America.

  8. New developments in canine hepatozoonosis in North America: a review

    Science.gov (United States)

    Little, Susan E; Allen, Kelly E; Johnson, Eileen M; Panciera, Roger J; Reichard, Mason V; Ewing, Sidney A

    2009-01-01

    Canine hepatozoonosis is caused by Hepatozoon canis and Hepatozoon americanum, apicomplexan parasites transmitted to dogs by ingestion of infectious stages. Although the two agents are phylogenetically related, specific aspects, including characteristics of clinical disease and the natural history of the parasites themselves, differ between the two species. Until recently, H. canis infections had not been clearly documented in North America, and autochthonous infection with H. americanum has yet to be reported outside of the southern United States. However, recent reports demonstrate H. canis is present in areas of North America where its vector tick, Rhipicephalus sanguineus, has long been endemic, and that the range of H. americanum is likely expanding along with that of its vector tick, Amblyomma maculatum; co-infections with the two organisms have also been identified. Significant intraspecific variation has been reported in the 18S rRNA gene sequence of both Hepatozoon spp.-infecting dogs, suggesting that each species may represent a complex of related genogroups rather than well-defined species. Transmission of H. americanum to dogs via ingestion of cystozoites in muscle of infected vertebrates was recently demonstrated, supporting the concept of predation as a means of natural transmission. Although several exciting advances have occurred in recent years, much remains to be learned about patterns of infection and the nature of clinical disease caused by the agents of canine hepatozoonosis in North America. PMID:19426444

  9. Recent Rates of Forest Harvest and Conversion in North America

    Science.gov (United States)

    Masek, Jeffrey G.; Cohen, Warren B.; Leckie, Donald; Wulder, Michael A.; Vargas, Rodrigo; de Jong, Ben; Healey, Sean; Law, Beverly; Birdsey, Richard; Houghton, R. A.; hide

    2011-01-01

    Incorporating ecological disturbance into biogeochemical models is critical for estimating current and future carbon stocks and fluxes. In particular, anthropogenic disturbances, such as forest conversion and wood harvest, strongly affect forest carbon dynamics within North America. This paper summarizes recent (2000.2008) rates of extraction, including both conversion and harvest, derived from national forest inventories for North America (the United States, Canada, and Mexico). During the 2000s, 6.1 million ha/yr were affected by harvest, another 1.0 million ha/yr were converted to other land uses through gross deforestation, and 0.4 million ha/yr were degraded. Thus about 1.0% of North America fs forests experienced some form of anthropogenic disturbance each year. However, due to harvest recovery, afforestation, and reforestation, the total forest area on the continent has been roughly stable during the decade. On average, about 110 m3 of roundwood volume was extracted per hectare harvested across the continent. Patterns of extraction vary among the three countries, with U.S. and Canadian activity dominated by partial and clear ]cut harvest, respectively, and activity in Mexico dominated by conversion (deforestation) for agriculture. Temporal trends in harvest and clearing may be affected by economic variables, technology, and forest policy decisions. While overall rates of extraction appear fairly stable in all three countries since the 1980s, harvest within the United States has shifted toward the southern United States and away from the Pacific Northwest.

  10. [Book review] Ducks, geese and swans of North America

    Science.gov (United States)

    Krapu, Gary L.

    1983-01-01

    This is the 3rd edition of the classic work "The Ducks, Geese and Swans of North America," which was first published in December 1942.  The original edition was authored by Francis C. Kortright with color plates by T. M. Shortt. An authoritative reference on North American waterfowl for many years, the book had become outdated as a result of major advances in the field of waterfowl biology. The need to update the 1st edition culminated in the publication in 1976 of a 2nd edition authored by Frank Bellrose. Readers interested in comparing features of the 1976 edition with other major recent works on North American waterfowl by P. A. Johnsgard and R. S. Palmer should read Weller (1977, Auk 94: 173).

  11. Icacinaceae from the eocene of Western North America.

    Science.gov (United States)

    Allen, Sarah E; Stull, Gregory W; Manchester, Steven R

    2015-05-01

    The Icacinaceae are a pantropical family of trees, shrubs, and climbers with an extensive Paleogene fossil record. Our improved understanding of phylogenetic relationships within the family provides an excellent context for investigating new fossil fruit and leaf material from the Eocene of western North America. We examined fossils from early and middle Eocene sediments of western Wyoming, northeastern Utah, northwestern Colorado, and Oregon and compared them with extant species of Iodes and other icacinaceous genera as well as previously described fossils of the family. Three new fossil species are described, including two based on endocarps (Iodes occidentalis sp. nov. and Icacinicaryites lottii sp. nov.) and one based on leaves (Goweria bluerimensis sp. nov.). The co-occurrence of I. occidentalis and G. bluerimensis suggests these might represent detached organs of a single species. A new genus, Biceratocarpum, is also established for morphologically distinct fossil fruits of Icacinaceae previously placed in Carpolithus. Biceratocarpum brownii gen. et comb. nov. resembles the London Clay species "Iodes" corniculata in possessing a pair of subapical protrusions. These fossils increase our knowledge of Icacinaceae in the Paleogene of North America and highlight the importance of the Northern Hemisphere in the early diversification of the family. They also document interchange with the Eocene flora of Europe and biogeographic connections with modern floras of Africa and Asia, where Icacinaceae are diverse today. The present-day restriction of this family to tropical regions offers ecological implications for the Eocene floras in which they occur. © 2015 Botanical Society of America, Inc.

  12. Causes of decadal climate variability over the North Pacific and North America

    International Nuclear Information System (INIS)

    Latif, M.; Barnett, T.P.

    1994-01-01

    The cause of decadal climate variability over the North Pacific and North America is investigated by analyzing data from a multi-decadal integration with a state of the art coupled ocean-atmosphere model and observations. About one third of the low-frequency climate variability in the region of interest can be attributed to a cycle involving unstable air-sea interactions between the subtropical gyre circulation in the North Pacific and the Aleutian low pressure system. The existence of this cycle provides a basis for long-range climate forecasting over the western United States at decadal time scales. (orig.)

  13. Echinococcus multilocularis in North America: the great unknown

    Science.gov (United States)

    Massolo, Alessandro; Liccioli, Stefano; Budke, Christine; Klein, Claudia

    2014-01-01

    Over the last decade, studies have begun to shed light on the distribution and genetic characterization of Echinococcus multilocularis, the causative agent of alveolar echinococcosis (AE), in North America. Recent findings indicate that the parasite is likely expanding its range in the central region of the United States and Canada and that invasions of European strains might have occurred. In our review, we present the available data on E. multilocularis infections in wild and domestic animals and humans in North America and emphasize the lack of knowledge on the distribution of the parasite in wild and domestic hosts. Furthermore, we stress the need to better understand the complexity of host communities and their roles in shaping the transmission and distribution of the parasite. We hypothesize that a lack of knowledge about AE by North American physicians might result in the misdiagnosis of cases and an underestimation of disease incidence. The endemic presence of the parasite in urban areas and a recent human case in Alberta, Canada, suggest that the scientific community may need to reconsider the local public health risks, re-assess past cases that might have been overlooked and increase surveillance efforts to identify new cases of human AE. PMID:25531581

  14. Security Inequalities in North America: Reassessing Regional Security Complex Theory

    Directory of Open Access Journals (Sweden)

    Richard Kilroy

    2017-12-01

    Full Text Available This article re-evaluates earlier work done by the authors on Regional Security Complex Theory (RSCT in North America, using sectoral analysis initially developed by Buzan and Waever, but also adding the variables of institutions, identity, and interests. These variables are assessed qualitatively in the contemporary context on how they currently impress upon the process of securitization within sectoral relations between Canada, Mexico, and the United States. The article reviews the movement from bilateral security relations between these states to the development of a trilateral response to regional security challenges post- 9/11. It further addresses the present period and what appears to be a security process derailed by recent political changes and security inequalities, heightened by the election of Donald Trump in 2016. The article argues that while these three states initially evinced a convergence of regional security interests after 9/11, which did create new institutional responses, under the current conditions, divergence in political interests and security inequalities have reduced the explanatory power of RSCT in North America. Relations between states in North American are becoming less characterized by the role of institutions and interests and more by identity politics in the region.

  15. Catalogue of Geadephaga (Coleoptera: Adephaga of America, north of Mexico

    Directory of Open Access Journals (Sweden)

    Yves Bousquet

    2012-11-01

    Full Text Available All scientific names of Trachypachidae, Rhysodidae, and Carabidae (including cicindelines recorded from America north of Mexico are catalogued. Available species-group names are listed in their original combinations with the author(s, year of publication, page citation, type locality, location of the name-bearing type, and etymology for many patronymic names. In addition, the reference in which a given species-group name is first synonymized is recorded for invalid taxa. Genus-group names are listed with the author(s, year of publication, page citation, type species with way of fixation, and etymology for most. The reference in which a given genus-group name is first synonymized is recorded for many invalid taxa. Family-group names are listed with the author(s, year of publication, page citation, and type genus. The geographical distribution of all species-group taxa is briefly summarized and their state and province records are indicated.One new genus-group taxon, Randallius new subgenus (type species: Chlaenius purpuricollis Randall, 1838, one new replacement name, Pterostichus amadeus new name for Pterostichus vexatus Bousquet, 1985, and three changes in precedence, Ellipsoptera rubicunda (Harris, 1911 for Ellipsoptera marutha (Dow, 1911, Badister micans LeConte, 1844 for Badister ocularis Casey, 1920, and Agonum deplanatum Ménétriés, 1843 for Agonum fallianum (Leng, 1919, are proposed. Five new genus-group synonymies and 65 new species-group synonymies, one new species-group status, and 12 new combinations (see Appendix 5 are established.The work also includes a discussion of the notable private North American carabid collections, a synopsis of all extant world geadephagan tribes and subfamilies, a brief faunistic assessment of the fauna, a list of valid species-group taxa, a list of North American fossil Geadephaga (Appendix 1, a list of North American Geadephaga larvae described or illustrated (Appendix 2, a list of Geadephaga species

  16. Interannual variability of western North Pacific SST anomalies and its impact on North Pacific and North America

    Science.gov (United States)

    Park, Jae-Heung; An, Soon-Il; Kug, Jong-Seong

    2017-12-01

    In this study, the interannual variability of sea surface temperature (SST) and its atmospheric teleconnection over the western North Pacific (WNP) toward the North Pacific/North America during boreal winter are investigated. First, we defined the WNP mode as the first empirical orthogonal function (EOF) mode of SST anomalies over the WNP region (100-165°E, 0-35°N), of which the principle component time-series are significantly correlated with several well-known climate modes such as the warm pool mode which is the second EOF mode of the tropical to North Pacific SST anomalies, North Pacific oscillation (NPO), North Pacific gyre oscillation (NPGO), and central Pacific (CP)-El Niño at 95% confidence level, but not correlated with the eastern Pacific (EP)-El Niño. The warm phase of the WNP mode (sea surface warming) is initiated by anomalous southerly winds through reduction of wind speed with the background of northerly mean winds over the WNP during boreal winter, i.e., reduced evaporative cooling. Meanwhile, the atmospheric response to the SST warming pattern and its diabatic heating further enhance the southerly wind anomaly, referred to the wind-evaporation-SST (WES) feedback. Thus, the WNP mode is developed and maintained through winter until spring, when the northerly mean wind disappears. Furthermore, it is also known that anomalous upper-level divergence associated with WNP mode leads to the NPO-like structure over the North Pacific and the east-west pressure contrast pattern over the North America through Rossby wave propagation, impacting the climate over the North Pacific and North America.

  17. North-South precipitation patterns in western North America on interannual-to-decadal timescales

    Science.gov (United States)

    Dettinger, M.D.; Cayan, D.R.; Diaz, Henry F.; Meko, D.M.

    1998-01-01

    The overall amount of precipitation deposited along the West Coast and western cordillera of North America from 25??to 55??N varies from year to year, and superimposed on this domain-average variability are varying north-south contrasts on timescales from at least interannual to interdecadal. In order to better understand the north-south precipitation contrasts, their interannual and decadal variations are studied in terms of how much they affect overall precipitation amounts and how they are related to large-scale climatic patterns. Spatial empirical orthogonal functions (EOFs) and spatial moments (domain average, central latitude, and latitudinal spread) of zonally averaged precipitation anomalies along the westernmost parts of North America are analyzed, and each is correlated with global sea level pressure (SLP) and sea surface temperature series, on interannual (defined here as 3-7 yr) and decadal (>7 yr) timescales. The interannual band considered here corresponds to timescales that are particularly strong in tropical climate variations and thus is expected to contain much precipitation variability that is related to El Nino-Southern Oscillation; the decadal scale is defined so as to capture the whole range of long-term climatic variations affecting western North America. Zonal EOFs of the interannual and decadal filtered versions of the zonal-precipitation series are remarkably similar. At both timescales, two leading EOFs describe 1) a north-south seesaw of precipitation pivoting near 40??N and 2) variations in precipitation near 40??N, respectively. The amount of overall precipitation variability is only about 10% of the mean and is largely determined by precipitation variations around 40??-45??N and most consistently influenced by nearby circulation patterns; in this sense, domain-average precipitation is closely related to the second EOF. The central latitude and latitudinal spread of precipitation distributions are strongly influenced by precipitation

  18. Distribution and protection of climatic refugia in North America.

    Science.gov (United States)

    Michalak, Julia L; Lawler, Joshua J; Roberts, David R; Carroll, Carlos

    2018-05-10

    As evidenced by past climatic refugia, locations projected to harbor remnants of present day climates may serve as critical refugia for current biodiversity in the face of modern climate change. Here, we map potential future climatic refugia across North America, defined as locations with increasingly rare climatic conditions. We identified these locations by tracking projected changes in the size and distribution of climate analogs over time. We used biologically-derived thresholds to define analogs and tested the impacts of dispersal limitation using four distances to limit analog searches. We identified at most 12% of North America as potential climatic refugia. Refugia extent varied depending on the analog threshold, dispersal distance, and climate projection. However, in all cases refugia were concentrated at high elevations and in topographically complex regions. Refugia identified using different climate projections were largely nested, suggesting that identified refugia were relatively robust to climate projection selection. Existing conservation areas cover approximately 10% of North America and yet protected up to 25% of identified refugia, indicating that protected areas disproportionately include refugia. Refugia located at lower latitudes (≤ 40°N) and slightly lower elevations (∼2500 m) were more likely to be unprotected. Based on our results, a 23% expansion of the protected areas network would be sufficient to protect the refugia that were present under all three of the climate projections that we explored. We propose that these refugia are high conservation priorities, due to their potential to harbor rare species in the future. However, these locations are simultaneously highly vulnerable to climate change over the long-term. We found that these refugia contracted substantially between the 2050s and the 2080s, emphasizing that the pace of climate change will strongly determine the availability and effectiveness of refugia for protecting today

  19. PAGES-Powell North America 2k database

    Science.gov (United States)

    McKay, N.

    2014-12-01

    Syntheses of paleoclimate data in North America are essential for understanding long-term spatiotemporal variability in climate and for properly assessing risk on decadal and longer timescales. Existing reconstructions of the past 2,000 years rely almost exclusively on tree-ring records, which can underestimate low-frequency variability and rarely extend beyond the last millennium. Meanwhile, many records from the full spectrum of paleoclimate archives are available and hold the potential of enhancing our understanding of past climate across North America over the past 2000 years. The second phase of the Past Global Changes (PAGES) North America 2k project began in 2014, with a primary goal of assembling these disparate paleoclimate records into a unified database. This effort is currently supported by the USGS Powell Center together with PAGES. Its success requires grassroots support from the community of researchers developing and interpreting paleoclimatic evidence relevant to the past 2000 years. Most likely, fewer than half of the published records appropriate for this database are publicly archived, and far fewer include the data needed to quantify geochronologic uncertainty, or to concisely describe how best to interpret the data in context of a large-scale paleoclimatic synthesis. The current version of the database includes records that (1) have been published in a peer-reviewed journal (including evidence of the record's relationship to climate), (2) cover a substantial portion of the past 2000 yr (>300 yr for annual records, >500 yr for lower frequency records) at relatively high resolution (<50 yr/observation), and (3) have reasonably small and quantifiable age uncertainty. Presently, the database includes records from boreholes, ice cores, lake and marine sediments, speleothems, and tree rings. This poster presentation will display the site locations and basic metadata of the records currently in the database. We invite anyone with interest in

  20. Renewable energy in North America: Moving toward a richer mix

    Energy Technology Data Exchange (ETDEWEB)

    Cobey, Cathy

    2010-09-15

    A follow-up to our January study with Economist Intelligence Unit, Renewable energy in North America. The update will further our call to action for a concerted group effort by energy suppliers, corporate consumers and government. 1. Introduction - State of the industry, progress made to replace carbon-based fossil fuels with alternative energy - Barriers - Pressure from public and government 2. Recent progress - Examine existing government incentive programs - International commitments - Examine the role of energy suppliers, corporate consumers and government 3. Call to Action - Creating an environment that encourages both supply and demand of renewable energy.

  1. Bat white-nose syndrome in North America

    Science.gov (United States)

    Blehert, David S.; Lorch, Jeffrey M.; Ballmann, Anne E.; Cryan, Paul M.; Meteyer, Carol U.

    2011-01-01

    * The newly described fungus, Geomyces destructans, causes an invasive skin infection in bats and is the likely agent of white-nose syndrome (WNS). * With immune system functions and body temperatures reduced during hibernation, bats may be unusually susceptible to a pathogenic fungus such as G. destructans. * WNS was first observed in a popular show cave near Albany, New York, leading some investigators to suspect that a visitor inadvertently introduced G. destructans at this site, triggering a wider WNS outbreak in North America. * Biologists trying to manage WNS within North American bat populations face major challenges, including the variety of susceptible host species, incredible dispersal capabilities of bats, difficulties in treating such populations, and persistence of the pathogen in their vulnerable underground habitats.

  2. Genetic calibration of species diversity among North America's freshwater fishes.

    Science.gov (United States)

    April, Julien; Mayden, Richard L; Hanner, Robert H; Bernatchez, Louis

    2011-06-28

    Freshwater ecosystems are being heavily exploited and degraded by human activities all over the world, including in North America, where fishes and fisheries are strongly affected. Despite centuries of taxonomic inquiry, problems inherent to species identification continue to hamper the conservation of North American freshwater fishes. Indeed, nearly 10% of species diversity is thought to remain undescribed. To provide an independent calibration of taxonomic uncertainty and to establish a more accessible molecular identification key for its application, we generated a standard reference library of mtDNA sequences (DNA barcodes) derived from expert-identified museum specimens for 752 North American freshwater fish species. This study demonstrates that 90% of known species can be delineated using barcodes. Moreover, it reveals numerous genetic discontinuities indicative of independently evolving lineages within described species, which points to the presence of morphologically cryptic diversity. From the 752 species analyzed, our survey flagged 138 named species that represent as many as 347 candidate species, which suggests a 28% increase in species diversity. In contrast, several species of parasitic and nonparasitic lampreys lack such discontinuity and may represent alternative life history strategies within single species. Therefore, it appears that the current North American freshwater fish taxonomy at the species level significantly conceals diversity in some groups, although artificially creating diversity in others. In addition to providing an easily accessible digital identification system, this study identifies 151 fish species for which taxonomic revision is required.

  3. Range expansion by Passer montanus in North America

    Science.gov (United States)

    Burnett, J.L.; Roberts, C.P.; Allen, Craig R.; Brown, M.B.; Moulton, M.P.

    2017-01-01

    Passer montanus became established in a small area of central North America following its introduction in 1870. P. montanus underwent minimal range expansion in the first 100 years following introduction. However, the North American population of P. montanus is now growing in size and expanding in geographic distribution, having expanded approximately 125 km to the north by 1970. We quantify the distance of spread by P. montanus from its introduction site in the greater St. Louis, Missouri-Illinois, USA area, using distributional (presence) data from the National Audubon Society Christmas Bird Count surveys for the period of 1951 to 2014. Linear regressions of the average annual range center of P. montanus confirmed significant shifts to the north at a rate of 3.3 km/year (P Linear regressions of the linear and angular distance of range center indicates significant northern movement (change in angle of mean range center; P < 0.001) since 1951. Our results quantify the extent of a northward range expansion, and suggesting a probable spread of this species northward.

  4. One Health training, research, and outreach in North America

    Directory of Open Access Journals (Sweden)

    Cheryl Stroud

    2016-11-01

    Full Text Available Background: The One Health (OH concept, formerly referred to as ‘One Medicine’ in the later part of the 20th century, has gained exceptional popularity in the early 21st century, and numerous academic and non-academic institutions have developed One Health programs. Objectives: To summarize One Health training, research, and outreach activities originating in North America. Methods: We used data from extensive electronic records maintained by the One Health Commission (OHC (www.onehealthcommission.org/ and the One Health Initiative (www.onehealthinitiative.com/ and from web-based searches, combined with the corporate knowledge of the authors and their professional contacts. Finally, a call was released to members of the OHC's Global One Health Community listserv, asking that they populate a Google document with information on One Health training, research, and outreach activities in North American academic and non-academic institutions. Results: A current snapshot of North American One Health training, research, and outreach activities as of August 2016 has evolved. Conclusions: It is clear that the One Health concept has gained considerable recognition during the first decade of the 21st century, with numerous current training and research activities carried out among North American academic, non-academic, government, corporate, and non-profit entities.

  5. The first reported ceratopsid dinosaur from eastern North America (Owl Creek Formation, Upper Cretaceous, Mississippi, USA).

    Science.gov (United States)

    Farke, Andrew A; Phillips, George E

    2017-01-01

    Ceratopsids ("horned dinosaurs") are known from western North America and Asia, a distribution reflecting an inferred subaerial link between the two landmasses during the Late Cretaceous. However, this clade was previously unknown from eastern North America, presumably due to limited outcrop of the appropriate age and depositional environment as well as the separation of eastern and western North America by the Western Interior Seaway during much of the Late Cretaceous. A dentary tooth from the Owl Creek Formation (late Maastrichtian) of Union County, Mississippi, represents the first reported occurrence of Ceratopsidae from eastern North America. This tooth shows a combination of features typical of Ceratopsidae, including a double root and a prominent, blade-like carina. Based on the age of the fossil, we hypothesize that it is consistent with a dispersal of ceratopsids into eastern North America during the very latest Cretaceous, presumably after the two halves of North America were reunited following the retreat of the Western Interior Seaway.

  6. Field Evaluations of Topical Arthropod Repellents in North, Central, and South America

    Science.gov (United States)

    2014-09-01

    De La Rocque et al. 2011) and their spread into higher elevations of Africa, Latin America , and Asia (Epstein 2001). Dengue fever and...denguehemorrhagic fever have resurgeddramatically in Latin America (Zell 2004). In North America ,West Nile virus has impacted signiÞcantly the health and welfare of...VECTOR CONTROL, PEST MANAGEMENT, RESISTANCE, REPELLENTS Field Evaluations of Topical Arthropod Repellents in North, Central , and South America KENDRA

  7. Low beta diversity of Maastrichtian dinosaurs of North America

    Science.gov (United States)

    Vavrek, Matthew J.; Larsson, Hans C. E.

    2010-01-01

    Beta diversity is an important component of large-scale patterns of biodiversity, but its explicit examination is more difficult than that of alpha diversity. Only recently have data sets large enough been presented to begin assessing global patterns of species turnover, especially in the fossil record. We present here an analysis of beta diversity of a Maastrichtian (71–65 million years old) assemblage of dinosaurs from the Western Interior of North America, a region that covers ≈1.5 × 106 km2, borders an epicontinental sea, and spans ≈20° of latitude. Previous qualitative analyses have suggested regional groupings of these dinosaurs and generally concluded that there were multiple distinct faunal regions. However, these studies did not directly account for sampling bias, which may artificially decrease similarity and increase turnover between regions. Our analysis used abundance-based data to account for sampling intensity and was unable to support any hypothesis of multiple distinct faunas; earlier hypothesized faunal delineations were likely a sampling artifact. Our results indicate a low beta diversity and support a single dinosaur community within the entire Western Interior region of latest Cretaceous North America. Homogeneous environments are a known driver of low modern beta diversities, and the warm equable climate of the late Cretaceous modulated by the epicontenental seaway is inferred to be an underlying influence on the low beta diversity of this ancient ecosystem. PMID:20404176

  8. Drought-induced vegetation stress in southwestern North America

    International Nuclear Information System (INIS)

    Zhang Xiaoyang; Goldberg, Mitchell; Tarpley, Dan; Kogan, Felix; Yu Yunyue; Friedl, Mark A; Morisette, Jeffrey

    2010-01-01

    Trends towards earlier greenup and increased average greenness have been widely reported in both humid and dry ecosystems. By analyzing NOAA (National Oceanic and Atmospheric Administration) AVHRR (Advanced Very High Resolution Radiometer) data from 1982 to 2007, we report complex trends in both the growing season amplitude and seasonally integrated vegetation greenness in southwestern North America and further highlight regions consistently experiencing drought stress. In particular, greenness measurements from 1982 to 2007 show an increasing trend in grasslands but a decreasing trend in shrublands. However, vegetation greenness in this period has experienced a strong cycle, increasing from 1982 to 1993 but decreasing from 1993 to 2007. The significant decrease during the last decade has reduced vegetation greenness by 6% in shrublands and 13% in grasslands (16% and 21%, respectively, in the severe drought years). The greenness cycle correlates to both annual precipitation and dry season length derived from NOAA North America Regional Reanalysis data. If drought events continue as predicted by climate models, they will exacerbate ecosystem degradation and reduce carbon uptake.

  9. 2014 outbreak of enterovirus D68 in North America.

    Science.gov (United States)

    Messacar, Kevin; Abzug, Mark J; Dominguez, Samuel R

    2016-05-01

    Enterovirus D68 (EV-D68) is an emerging picornavirus which causes severe respiratory disease, predominantly in children. In 2014, the largest and most widespread outbreak of EV-D68 described to date was reported in North America. Hospitals throughout the United States and Canada reported surges in patient volumes and resource utilization from August to October, 2014. In the US a total of 1,153 infections were confirmed in 49 states, although this is an underestimate of the likely millions of cases that occurred but were not tested. EV-D68 was detected in 14 patients who died; the role of the virus in these deaths is unknown. A possible association between EV-D68 and cases of acute flaccid paralysis with spinal cord gray matter lesions, known as acute flaccid myelitis, was observed during the outbreak and is under investigation. The 2014 outbreak of EV-D68 in North America demonstrates the public health importance of this emerging pathogen. © 2015 Wiley Periodicals, Inc.

  10. Field Studies on Lyme Disease in North America

    Directory of Open Access Journals (Sweden)

    Joseph Piesman

    1991-01-01

    Full Text Available The primary tick vector of Borrelia burgdorferi in eastern and central North America is Ixodes dammini; in western North America, Ixodes pacificus. Searching for the appropriate vector is the first step in determining whether a region is endemic and enzootic for the spirochete B burgdorferi, the etiological agent of Lyme disease, followed by examination of the ticks (questing or already attached to hosts and wildlife for the spirochete. Questing ticks can be collected through a variety of methods. The two major animal hosts for I dammini are the white-footed mouse Peromyscus leucopus and the white-tailed deer Odocoileus virginianus. Sampling strategies should consider habitat and season. All three life stages of the vector tick should be located, indicating a self-sustaining population. Although B burgdorferi can be detected in many ways, there is no substitute for isolating the spirochete in Barbour-Stoenner-Kelly II medium for definitive proof of the presence of the Lyme disease spirochete.

  11. Prospects for exotic beam facilities in North America

    CERN Document Server

    Nolen, J A

    2002-01-01

    There are several nuclear physics laboratories in North America that have on-going research using energetic and stopped radioactive beams. These include the large ISOL-type programs ISAC at TRIUMF and HRIBF at Oak Ridge and the in-flight fragmentation program at the NSCL of Michigan State University. There are also smaller, more specialized, programs using a variety of techniques at the 88-inch cyclotron of Berkeley, ATLAS at Argonne, the Cyclotron Institute of Texas A&M University, the Nuclear Structure Laboratory at Notre Dame University, and the Nuclear Structure Laboratory at SUNY/Stony Brook. There are also three projects on the horizon in North America for new capabilities in both the near term and more distant future. The intensities of the in-flight fragment beams at the NSCL will be increased dramatically very soon as the Coupled Cyclotron Project will be completed and commissioned for research by mid-2001. A new project, ISAC-II, has been approved in Canada. For the longer term, the United State...

  12. Industrial Hemp in North America: Production, Politics and Potential

    Directory of Open Access Journals (Sweden)

    Jerome H. Cherney

    2016-11-01

    Full Text Available Most of the Western World banned the cultivation of Cannabis sativa in the early 20th century because biotypes high in ∆9-tetrahydrocannabinol (THC, the principal intoxicant cannabinoid are the source of marijuana. Nevertheless, since 1990, dozens of countries have authorized the licensed growth and processing of “industrial hemp” (cultivars with quite low levels of THC. Canada has concentrated on hemp oilseed production, and very recently, Europe changed its emphasis from fiber to oilseed. The USA, historically a major hemp producer, appears on the verge of reintroducing industrial hemp production. This presentation provides updates on various agricultural, scientific, social, and political considerations that impact the commercial hemp industry in the United States and Canada. The most promising scenario for the hemp industry in North America is a continuing focus on oilseed production, as well as cannabidiol (CBD, the principal non-intoxicant cannabinoid considered by many to have substantial medical potential, and currently in great demand as a pharmaceutical. Future success of the industrial hemp industry in North America is heavily dependent on the breeding of more productive oilseed cultivars, the continued development of consumer goods, reasonable but not overly restrictive regulations, and discouragement of overproduction associated with unrealistic enthusiasm. Changing attitudes have generated an unprecedented demand for the cannabis plant and its products, resulting in urgent needs for new legislative, regulatory, and business frameworks, as well as scientific, technological, and agricultural research.

  13. Sustainable energy developments in Europe and North America

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    Europe and North America account for 70% of world energy consumption; 61% of which is fossil fuels. Energy trends and patterns in this region, if pursued, would have a large impact on region- and world-wide energy and ecosystems. This report addresses the issues of whether projected trends and supply structures would be 'sustainable' i.e. meet the needs of the present without compromising the ability of future generations to meet their own needs; what adaptations are warranted; and what role could and should be played by regional energy and environmental co-operation: including through the United Nations Economic Commission for Europe. The report is divided into three parts. Part 1 studies the interrelationships between environmental and energy policies in Europe and North America until 2010 and beyond. Part II contains research notes on CO{sub 2} concentration and energy scenarios; investment requirements of the energy supply industries in the ERE region for 1980-2000; energy technologies for the first decades of the 21st century. Scope and conditions for enhancing energy efficiency in the ERE region; CO{sub 2} and climate variation and its impact on energy policy in the USSR and European CMEA countries; the role of new and renewable sources of energy; projected energy developments in the ERE region until 2010, and pollution: synopsis of various international studies on the sustainability of energy developments. Part III describes the energy program of the UN-ECE.

  14. Arctic-midlatitude weather linkages in North America

    Science.gov (United States)

    Overland, James E.; Wang, Muyin

    2018-06-01

    There is intense public interest in whether major Arctic changes can and will impact midlatitude weather such as cold air outbreaks on the central and east side of continents. Although there is progress in linkage research for eastern Asia, a clear gap is conformation for North America. We show two stationary temperature/geopotential height patterns where warmer Arctic temperatures have reinforced existing tropospheric jet stream wave amplitudes over North America: a Greenland/Baffin Block pattern during December 2010 and an Alaska Ridge pattern during December 2017. Even with continuing Arctic warming over the past decade, other recent eastern US winter months were less susceptible for an Arctic linkage: the jet stream was represented by either zonal flow, progressive weather systems, or unfavorable phasing of the long wave pattern. The present analysis lays the scientific controversy over the validity of linkages to the inherent intermittency of jet stream dynamics, which provides only an occasional bridge between Arctic thermodynamic forcing and extended midlatitude weather events.

  15. Conservation of native Pacific trout diversity in western North America

    Science.gov (United States)

    Penaluna, Brooke E.; Abadía-Cardoso, Alicia; Dunham, Jason B.; García de León, Francisco J; Gresswell, Robert E.; Luna, Arturo Ruiz; Taylor, Eric B.; Shepard, Bradley B.; Al-Chokhachy, Robert K.; Muhlfeld, Clint C.; Bestgen, Kevin R.; Rogers, Kevin H.; Escalante, Marco A; Keeley, Ernest R; Temple, Gabriel; Williams, Jack E.; Matthews, Kathleen; Pierce, Ron; Mayden, Richard L.; Kovach, Ryan; Garza, John Carlos; Fausch, Kurt D.

    2016-01-01

    Pacific trout Oncorhynchus spp. in western North America are strongly valued in ecological, socioeconomic, and cultural views, and have been the subject of substantial research and conservation efforts. Despite this, the understanding of their evolutionary histories, overall diversity, and challenges to their conservation is incomplete. We review the state of knowledge on these important issues, focusing on Pacific trout in the genus Oncorhynchus. Although most research on salmonid fishes emphasizes Pacific salmon, we focus on Pacific trout because they share a common evolutionary history, and many taxa in western North America have not been formally described, particularly in the southern extent of their ranges. Research in recent decades has led to the revision of many hypotheses concerning the origin and diversification of Pacific trout throughout their range. Although there has been significant success at addressing past threats to Pacific trout, contemporary and future threats represented by nonnative species, land and water use activities, and climate change pose challenges and uncertainties. Ultimately, conservation of Pacific trout depends on how well these issues are understood and addressed, and on solutions that allow these species to coexist with a growing scope of human influences.

  16. Parasites of freshwater fishes in North America: why so neglected?

    Science.gov (United States)

    Scholz, Tomáš; Choudhury, Anindo

    2014-02-01

    Fish parasitology has a long tradition in North America and numerous parasitologists have contributed considerably to the current knowledge of the diversity and biology of protistan and metazoan parasites of freshwater fishes. The Journal of Parasitology has been essential in disseminating this knowledge and remains a significant contributor to our understanding of fish parasites in North America as well as more broadly at the international level. However, with a few exceptions, the importance of fish parasites has decreased during the last decades, which is reflected in the considerable decline of funding and corresponding decrease of attention paid to these parasites in Canada and the United States of America. After the 'golden age' in the second half of the 20th Century, fish parasitology in Canada and the United States went in a new direction, driven by technology and a shift in priorities. In contrast, fish parasitology in Mexico has undergone rapid development since the early 1990s, partly due to extensive international collaboration and governmental funding. A critical review of the current data on the parasites of freshwater fishes in North America has revealed considerable gaps in the knowledge of their species composition, host specificity, life cycles, evolution, phylogeography, and relationships with their fish hosts. As to the key question, "Why so neglected?" this is probably because: (1) fish parasites are not in the forefront due to their lesser economic importance; (2) there is little funding for this kind of research, especially if a practical application is not immediately apparent; and (3) of shifting interests and a shortage of key personalities to train a new generation (they switched to marine habitats or other fields). Some of the opportunities for future research are outlined, such as climate change and cryptic species diversity. A significant problem challenging future research seems to be the loss of trained and experienced fish

  17. Review of the genera of Conoderinae (Coleoptera, Curculionidae from North America, Central America, and the Caribbean

    Directory of Open Access Journals (Sweden)

    Salvatore S. Anzaldo

    2017-07-01

    Full Text Available The thirty-nine extant genera of Conoderinae known to occur in North America, Central America, and the Caribbean are reviewed based on external morphology. An identification key is provided along with diagnoses, distributions, species counts, and natural history information, when known, for each genus. Morphological character systems of importance for weevil classification are surveyed, potential relationships among the tribes and genera are discussed, and groups most in need of taxonomic and phylogenetic attention are identified. The following genera are transferred to new tribes: Acoptus LeConte, 1876 from the Lechriopini to the Othippiini (new placement and the South American genus Hedycera Pascoe, 1870 from the Lechriopini to the Piazurini (new placement. Philides Champion, 1906 and Philinna Champion, 1906 are transferred from the Lechriopini to Conoderinae incertae sedis (new placement although their placement as conoderines is uncertain. The species Copturomimus cinereus Heller, 1895 is designated as the type species of the genus Copturomimus Heller, 1895.

  18. The Asian-Bering-North American teleconnection: seasonality, maintenance, and climate impact on North America

    Science.gov (United States)

    Yu, Bin; Lin, H.; Wu, Z. W.; Merryfield, W. J.

    2018-03-01

    The Asian-Bering-North American (ABNA) teleconnection index is constructed from the normalized 500-hPa geopotential field by excluding the Pacific-North American pattern contribution. The ABNA pattern features a zonally elongated wavetrain originating from North Asia and flowing downstream across Bering Sea and Strait towards North America. The large-scale teleconnection is a year-round phenomenon that displays strong seasonality with the peak variability in winter. North American surface temperature and temperature extremes, including warm days and nights as well as cold days and nights, are significantly controlled by this teleconnection. The ABNA pattern has an equivalent barotropic structure in the troposphere and is supported by synoptic-scale eddy forcing in the upper troposphere. Its associated sea surface temperature anomalies exhibit a horseshoe-shaped structure in the North Pacific, most prominent in winter, which is driven by atmospheric circulation anomalies. The snow cover anomalies over the West Siberian plain and Central Siberian Plateau in autumn and spring and over southern Siberia in winter may act as a forcing influence on the ABNA pattern. The snow forcing influence in winter and spring can be traced back to the preceding season, which provides a predictability source for this teleconnection and for North American temperature variability. The ABNA associated energy budget is dominated by surface longwave radiation anomalies year-round, with the temperature anomalies supported by anomalous downward longwave radiation and damped by upward longwave radiation at the surface.

  19. Large blackouts in North America: Historical trends and policy implications

    International Nuclear Information System (INIS)

    Hines, Paul; Apt, Jay; Talukdar, Sarosh

    2009-01-01

    Using data from the North American Electric Reliability Council (NERC) for 1984-2006, we find several trends. We find that the frequency of large blackouts in the United States has not decreased over time, that there is a statistically significant increase in blackout frequency during peak hours of the day and during late summer and mid-winter months (although non-storm-related risk is nearly constant through the year) and that there is strong statistical support for the previously observed power-law statistical relationship between blackout size and frequency. We do not find that blackout sizes and blackout durations are significantly correlated. These trends hold even after controlling for increasing demand and population and after eliminating small events, for which the data may be skewed by spotty reporting. Trends in blackout occurrences, such as those observed in the North American data, have important implications for those who make investment and policy decisions in the electricity industry. We provide a number of examples that illustrate how these trends can inform benefit-cost analysis calculations. Also, following procedures used in natural disaster planning we use the observed statistical trends to calculate the size of the 100-year blackout, which for North America is 186,000 MW.

  20. State of the Carbon Cycle of North America: Overarching Findings

    Science.gov (United States)

    Mayes, M. A.; Reed, S.; Najjar, R.; Romero-Lankao, P.; Birdsey, R.

    2016-12-01

    This presentation will provide an overarching summary of the second "State of the Carbon Cycle of North America Report" (SOCCR2) from the perspective of the five editorial lead authors. The chapters of SOCCR2 represent a major update and much new material since the original report published a decade ago. The new report includes an overview of the North American carbon budget and future projections, the consequences of changes to the carbon budget, details of the carbon budget in major terrestrial and aquatic ecosystems and anthropogenic drivers, and implications for carbon management. The chapters focus on advances since the 2007 report, but also include new focus areas such as soil carbon, tribal lands, as well as greater emphasis on aquatic systems and the role of societal drivers and decision making on the carbon cycle. In addition, methane and the role of nitrogen will be considered to a greater extent than before. Each chapter also contains a section focusing on national and regional accounting to complement the overarching North American framework. In conclusion, SOCCR2 is expected to provide an updated assessment and a unique perspective on the carbon cycle, which will contribute to the next U.S. National Climate Assessment.

  1. A survey of transmission tariffs in North America

    International Nuclear Information System (INIS)

    Lusztig, C.; Feldberg, P.; Orans, R.; Olson, A.

    2006-01-01

    One goal of electricity restructuring is to facilitate voluntary transactions in workably competitive wholesale electricity markets. Unfettered wholesale trading, however, can only take place under open and comparable access to transmission by all market participants at non-discriminatory tariffs. Since a rich body of literature exists for topics like nodal pricing, transmission rights, ancillary services, and optimal dispatch, this paper's focus is to survey the transmission tariffs actually used in North America to achieve open and comparable transmission access. In doing so, it provides a practical guide to developing a transmission tariff, illustrated by the survey's role in shaping the tariff filed by a company like the British Columbia Transmission Company (BCTC) with its regulator, the British Columbia Utilities Commission (BCUC). (author)

  2. Palm harvest impacts in north-western South America

    DEFF Research Database (Denmark)

    Balslev, Henrik

    2011-01-01

    Tropical forests harbor thousands of useful plants that are harvested and used in subsistence economies or traded in local, regional or international markets. The effect on the ecosystem is little known, and the forests resilience is badly understood. Palms are the most useful group of plants...... in tropical American forests. This paper introduces a cross-disciplinary study of the effects of harvesting palm products from the tropical forests in north-western South America. The size of the resource is estimated through palm community studies in the different forest formations that determines the number...... of species and individuals of all palm species. The genetic structure of useful palm species is studied to determine how much harvesting of the species contributes to genetic erosion of its populations, and whether extraction can be made without harm. Almost all palm species are used in rural communities...

  3. Recent trends in gas contracting in North America

    International Nuclear Information System (INIS)

    Maffitt, D. W.

    1999-01-01

    An overview of recent business trends impacting upon natural gas contracting in North America is provided. Among the trends examined are supply and demand, natural gas prices, access to the U.S. market, gas sales contracts, electronic gas sales, retail level marketing, the growing popularity of 'one-stop shopping', and standardization of contracts. Overall, supplies appear to be adequate for now, demand is growing, prices are volatile, short-term contracts are more popular than long-term ones, electronic commerce combined with one-stop shopping marketing at the retail level is growing, and standardization of spot and short-term gas sales contracts is slowly being accepted by industry as a means to to improve the efficiency of the market. 12 refs

  4. The paradigm of grizzly bear restoration in North America

    Science.gov (United States)

    Schwartz, C. C.; Maehr, David S.; Noss, Reed F.; Larkin, J.L.

    2002-01-01

    Grizzly bear restoration and recovery is a controversial, highly politicized process. By 1959, when the Craigheads began their pioneering work on Yellowstone grizzly bears, the species had been reduced to a remnant of its historic range. Prior to the colonization of North America by Europeans, the grizzly lived in relatively pristine habitats with aboriginal Native Americans. As civilization expanded, humans changed the face of the landscape, converting grizzly bear habitat to farms and ranches. People killed grizzlies to protect livestock and eliminate a perceived threat to human safety. In concert, habitat loss and direct human-caused mortality had effectively eliminated the grizzly from 95 percent of its historic range in the conterminous United States by the 1920s (Servheen 1989). Grizzly bear numbers had been reduced nearly 98 percent by 1975 when the species was listed as threatened under the Endangered Species Act (ESA) (USFWS 1993).

  5. Changing perspectives on pearly mussels, North America's most imperiled animals

    Science.gov (United States)

    Strayer, David L.; Downing, John A.; Haag, Wendell R.; King, Timothy L.; Layzer, James B.; Newton, Teresa J.; Nichols, S. Jerrine

    2004-01-01

    Pearly mussels (Unionacea) are widespread, abundant, and important in freshwater ecosystems around the world. Catastrophic declines in pearly mussel populations in North America and other parts of the world have led to a flurry of research on mussel biology, ecology, and conservation. Recent research on mussel feeding, life history, spatial patterning, and declines has augmented, modified, or overturned long-held ideas about the ecology of these animals. Pearly mussel research has begun to benefit from and contribute to current ideas about suspension feeding, life-history theory, metapopulations, flow refuges, spatial patterning and its effects, and management of endangered species. At the same time, significant gaps in understanding and apparent paradoxes in pearly mussel ecology have been exposed. To conserve remaining mussel populations, scientists and managers must simultaneously and aggressively pursue both rigorous research and conservation actions.

  6. Monitoring the shorebirds of North America: Towards a unified approach

    Science.gov (United States)

    Skagen, S.K.; Bart, J.; Andres, B.; Brown, S.; Donaldson, G.; Harrington, B.; Johnston, V.; Jones, S.L.; Morrison, R.I.G.

    2003-01-01

    The Program for Regional and International Shorebird Monitoring (PRISM) has recently developed a single blueprint for monitoring shorebirds in Canada and the United States in response to needs identified by recent shorebird conservation plans. The goals of PRISM are to: (1) estimate the size of breeding populations of 74 shorebird taxa in North America; (2) describe the distribution, abundance, and habitat relationships for these taxa; (3) monitor trends in shorebird population size; (4) monitor shorebird numbers at stopover locations, and; (5) assist local managers in meeting their shorebird conservation goals. The initial focus has been on developing methods to estimate trends in population size. A three-part approach for estimating trends includes: (1) breeding surveys in arctic, boreal, and temperate regions, (2) migration surveys, and (3) wintering surveys.

  7. Phylogeography of infectious haematopoietic necrosis virus in North America

    DEFF Research Database (Denmark)

    Kurath, G.; Garver, K.A.; Troyer, R.M.

    2003-01-01

    Infectious hematopoietic necrosis virus (IHNV) is a rhabdoviral pathogen that infects wild and cultured salmonid fish throughout the Pacific Northwest of North America. IHNV causes severe epidemics in young fish and can cause disease or occur asymptomatically in adults. In a broad survey of 323...... IHNV field isolates, sequence analysis of a 303 nucleotide variable region within the glycoprotein gene revealed a maximum nucleotide diversity of 8(.)6%, indicating low genetic diversity overall for this virus. Phylogenetic analysis revealed three major virus genogroups, designated U, M and L, which...... varied in topography and geographical range. Intragenogroup genetic. diversity measures indicated that the M genogroup had three- to fourfold more diversity than the other genogroups and suggested relatively rapid evolution of the M genogroup and stasis within the U genogroup. We speculate that factors...

  8. Missourian (early Late Pennsylvanian) climate in Midcontinent North America

    Energy Technology Data Exchange (ETDEWEB)

    Schutter, S.R.; Heckel, P.H.

    1985-06-01

    The abrupt decrease in mineable coals from Desmoinesian to Missourian rocks in Midcontinent North America has been related by several lines of evidence to the probability that Missourian climate became at least seasonally drier than Desmoinesian climate. This represents a transition from the equatorial Desmoinesian rainforest climate to the arid Permian climate, as North America moved northward from the equator. This change is reflected in the progression of evaporites from western Colorado in the Desmoinesian to Kansas in the Permian. Direct climatic evidence from soils in two Missourian shales deposited at low stands of sea-level includes caliche horizons, incompletely leached mixed-layer clays. Less direct climatic evidence includes the greater proportion of marine limestone deposited at intermediate sea-level stands in the Missourian than in the Desmoinesian part of the sequence, in conjunction with the greater abundance and thickness of oolite and shore-line facies in Missourian limestones than in Desmoinesian counterparts. This probably reflects increasing dryness of the climate, which would have led to decreased detrital influx and increased salinity as rainfall and runoff diminished. Indirect climatic evidence in offshore black phosphatic shales deposited at highest sea-level stands involves possible seasonality in organic and phosphatic laminations, related to periodicity of upwelling in the tropical trade-wide belt under the strong monsoonal influence of Pangaea. Mid-continent Missourian climates probably ranged from tropical monsoon to tropical savanna or hot steppe, all having wet-dry seasonality. The coincident extinctions of conodont, brachiopod, and other marine genera as well as the loss of swamp lycopods at the end of the Desmoinesian suggest the possibility that a greater than usual drop in sea level affected both realms at this time, while the climate was becoming drier. 91 references.

  9. Sexual Health Competencies for Undergraduate Medical Education in North America.

    Science.gov (United States)

    Bayer, Carey Roth; Eckstrand, Kristen L; Knudson, Gail; Koehler, Jean; Leibowitz, Scott; Tsai, Perry; Feldman, Jamie L

    2017-04-01

    The number of hours spent teaching sexual health content and skills in medical education continues to decrease despite the increase in sexual health issues faced by patients across the lifespan. In 2012 and 2014, experts across sexuality disciplines convened for the Summits on Medical School Education and Sexual Health to strategize and recommend approaches to improve sexual health education in medical education systems and practice settings. One of the summit recommendations was to develop sexual health competencies that could be implemented in undergraduate medical education curricula. To discuss the process of developing sexual health competencies for undergraduate medical education in North America and present the resulting competencies. From 2014 to 2016, a summit multidisciplinary subcommittee met through face-to-face, phone conference, and email meetings to review prior competency-based guidelines and then draft and vet general sexual health competencies for integration into undergraduate medical school curricula. The process built off the Association of American Medical Colleges' competency development process for training medical students to care for lesbian, gay, bisexual, transgender, and gender non-conforming patients and individuals born with differences of sex development. This report presents the final 20 sexual health competencies and 34 qualifiers aligned with the 8 overall domains of competence. Development of a comprehensive set of sexual health competencies is a necessary first step in standardizing learning expectations for medical students upon completion of undergraduate training. It is hoped that these competencies will guide the development of sexual health curricula and assessment tools that can be shared across medical schools to ensure that all medical school graduates will be adequately trained and comfortable addressing the different sexual health concerns presented by patients across the lifespan. Bayer CR, Eckstrand KL, Knudson G, et

  10. Practice Patterns of Dentist Anesthesiologists in North America.

    Science.gov (United States)

    Young, Andrew S; Fischer, Michael W; Lang, Nicholas S; Cooke, Matthew R

    2018-01-01

    This study provides trends in the discipline of dental anesthesiology. A questionnaire-based survey was sent to 338 members of the American Society of Dentist Anesthesiologists to evaluate practice patterns. One focus of the study was modality of sedation/anesthesia used for dentistry in North America. Age, gender, years in practice, and geographic region of practice were also obtained. Data gathered from the returned questionnaires were entered into an Excel spreadsheet and then imported into JMP Statistical Discovery Software (v12.2 Pro) for descriptive analysis. A total of 112 surveys were completed electronically and 102 surveys were returned via post, for a total response rate of 63.3% ( N = 214). Data from this survey suggested a wide variation of therapeutic practices among dentist anesthesiologists in North America. Of the surveyed dentist anesthesiologists, 58.7% (SE = 4.2%) practice as mobile providers, 32.2% (SE = 3.1%) provide care in an academic environment, and 27.7% (SE = 2.8%) function as operator/anesthetists. The majority of anesthesia is provided for pediatric dentistry (47.0%, SE = 4.2%), oral and maxillofacial surgery (18.5%, SE = 3.9%), and special needs (16.7%, SE = 3.6%). Open-airway (58.7%, SE = 5.5%) sedation/anesthesia was the preferred modality of delivery, compared with the use of advanced airway (41.3%, SE = 4.6%). The demographics show diverse practice patterns of dentist anesthesiologists in multiple regions of the continent. Despite concerns regarding specialty recognition, reimbursement difficulties, and competition from alternative anesthesia providers, the overall perceptions of dentist anesthesiologists and the future of the field seem largely favorable.

  11. Structure and dynamics of basin forested wetlands in North America

    International Nuclear Information System (INIS)

    Brown, S.

    1990-01-01

    Freshwater basin wetlands are found in depressions of various depths, generally in areas where precipitation exceeds evapotranspiration or where the depression intersects the water table creating groundwater seeps or springs. Forested basins are those that contain woody vegetation with the potential for reaching tree stature; they do not include woody shrub wetlands. In North America these areas are mainly in the central and eastern region. Pertinent information and reviews on the distribution, floristic composition, structure and dynamics of basin forested wetlands are summarized. The major emphasis is on freshwater wetlands, but data for saltwater wetlands mainly from Florida and tropical America are included. The external factors affecting basin wetlands or the important components of a wetlands energy signature are described as well as the distribution and floristic composition of representative basin wetlands. Sections on structural characteristics, organic matter dynamics, and nutrient cycling comprise the bulk of quantitative information. The effects of disturbances, both natural and human induced, with varying degrees of impact depending upon the intensity and on the part of the ecosystem to which the stressor is applied are evaluated. Examples of stressors in basin wetlands include water impoundment, water diversion, thermal stress from hot water, sedimentation, addition of toxic substances, addition of wastewater, oil spills, and harvesting. 86 refs., 5 figs., 11 tabs

  12. West Nile virus and North America: an unfolding story.

    Science.gov (United States)

    Glaser, A

    2004-08-01

    Before the introduction of the West Nile virus (WNV) into the United States of America (USA) in 1999, conditions in North America were ideal for an arboviral epidemic. Such factors as the large, susceptible and non-immune animal and human populations, the presence of competent vectors, increasing international travel and commerce, existing methods for rapid dissemination and an ill-prepared animal and public health infrastructure all combined to create the essential elements for a severe animal and public health crisis--the 'perfect microbial storm'. The introduction of WNV into New York City was the final factor, serving as the catalyst to initiate one of the most significant epidemics in the USA. The spread of WNV across the country resulted in very large populations of wildlife, equines and people being exposed and infected. The epidemic is still not fully understood and its character continues to change and adapt. The recent recognition of a number of non-vector modes of transmission has revealed the disease as a greater threat and more difficult to control than first thought. West Nile virus gives every indication that it will become a permanent part of the 'medical landscape' of the USA, continuing to threaten wildlife, domestic animals and humans as a now endemic disease. This paper discusses the features of this extraordinary epidemic, and emphasises the need for an integrated surveillance system, greater diagnostic capacity and improved control strategies.

  13. Potential for small-diameter sawtimber utilization by the current sawmill industry in western North America.

    Science.gov (United States)

    Francis G. Wagner; Charles E. Keegan; Roger D. Fight; Susan. Willits

    1998-01-01

    New silvicultural prescriptions for ecosystem management on both public and private timberlands in western North America will likely result in an influx of relatively small-diameter sawtimber for processing. Since sawmills currently process a majority of sawtimber harvested in western North America (more than 80% in some regions), this study concentrated on...

  14. Projected future suitable habitat and productivity of Douglas-fir in western North America

    Science.gov (United States)

    Aaron R. Weiskittel; Nicholas L. Crookston; Gerald E. Rehfeldt

    2012-01-01

    Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) is one of the most common and commercially important species in western North America. The species can occupy a range of habitats, is long-lived (up to 500 years), and highly productive. However, the future of Douglas-fir in western North America is highly uncertain due to the expected changes in climate conditions....

  15. 75 FR 80109 - Nissan North America, Inc., Receipt of Petition for Decision of Inconsequential Noncompliance

    Science.gov (United States)

    2010-12-21

    ...-0171; Notice 1] Nissan North America, Inc., Receipt of Petition for Decision of Inconsequential Noncompliance Nissan North America, Inc. (Nissan) \\1\\ has determined that certain model year 2008 through 2010 Nissan Titan trucks do not fully comply with the requirements of paragraph S19.2.2(b) of Federal Motor...

  16. 78 FR 40546 - Nissan North America, Incorporated, Receipt of Petition for Decision of Inconsequential...

    Science.gov (United States)

    2013-07-05

    ...-0142; Notice 1] Nissan North America, Incorporated, Receipt of Petition for Decision of Inconsequential...: Nissan North America, Inc. (Nissan) \\1\\ has determined that certain model year (MY) 2009 through 2012 Nissan Titan trucks manufactured from January 31, 2008 to July 17, 2012 and MY 2012 Nissan NV trucks...

  17. 78 FR 59090 - Nissan North America, Incorporated, Grant of Petition for Decision of Inconsequential Noncompliance

    Science.gov (United States)

    2013-09-25

    ...-0142; Notice 2] Nissan North America, Incorporated, Grant of Petition for Decision of Inconsequential.... SUMMARY: Nissan North America, Inc. (Nissan) has determined that certain model year (MY) 2009 through 2012 Nissan Titan trucks manufactured from January 31, 2008 to July 17, 2012 and MY 2012 Nissan NV trucks...

  18. Postglacial viability and colonization in North America's ice-free corridor

    DEFF Research Database (Denmark)

    Pedersen, Mikkel W.; Ruter, Anthony; Schweger, Charles

    2016-01-01

    During the Last Glacial Maximum, continental ice sheets isolated Beringia (northeast Siberia and northwest North America) from unglaciated North America. By around 15 to 14 thousand calibrated radiocarbon years before present (cal. kyr BP), glacial retreat opened an approximately 1,500-km...

  19. An atypical biotype I Actinobacillus pleuropneumoniae serotype 13 is present in North America

    DEFF Research Database (Denmark)

    Perry, Malcolm B.; Angen, Øystein; MacLean, Leann L.

    2012-01-01

    Atypical Actinobacillus pleuropneumoniae serotype 13 strains present in North America are described here for the first time. Different from serotype 13 strains described in Europe, North America strains are biotype I and antigenically related to both, serotypes 13 and 10. Chemical and structural...

  20. Cross-continental patterns in the timing of southward Peregrine Falcon migration in North America

    NARCIS (Netherlands)

    Worcester, R.; Ydenberg, R.C.

    2008-01-01

    We analyzed the timing of southward migration of Peregrine Falcons (Falco peregrinus) across North America, based on passage data compiled by the Hawk Migration Association of North America, supplemented with two other similar datasets collected by individual observers at sites in western Canada.

  1. 75 FR 73159 - Continental Tire North America, Inc., Receipt of Petition for Decision of Inconsequential...

    Science.gov (United States)

    2010-11-29

    ...-0153; Notice 1] Continental Tire North America, Inc., Receipt of Petition for Decision of Inconsequential Noncompliance Continental Tire North America, Inc., (Continental),\\1\\ has determined that certain passenger car replacement tires manufactured in 2009 do not fully comply with paragraph S5.5(b) of Federal...

  2. 77 FR 24762 - Mitsubishi Motors North America, Inc., Grant of Petition for Decision of Inconsequential...

    Science.gov (United States)

    2012-04-25

    ... instruction standards. Refer to Hyundai Motor Company (74 FR 9125, March 2, 209); Ford Motor Company (73 FR 11462, March 3, 2008); Mazda North America Operations (73 FR 11464, March 3, 2008); Ford Motor Company...-0176; Notice 2] Mitsubishi Motors North America, Inc., Grant of Petition for Decision of...

  3. 75 FR 28297 - Sychip, Inc., a Wholly Owned Subsidiary of Murata Electronics North America, Inc. (MENA...

    Science.gov (United States)

    2010-05-20

    ... Owned Subsidiary of Murata Electronics North America, Inc. (MENA), Including Workers Whose Unemployment Insurance (UI) Wages Are Paid Through Either Adminstaff or MENA, Plano, TX; Amended Certification Regarding... owned subsidiary of Murata Electronics North America, Inc. (MENA). Since January 1, 2010, workers...

  4. Opportunities and uses of biochar on forest sites in North America [Chapter 15

    Science.gov (United States)

    Deborah S. Page-Dumroese; Mark D. Coleman; Sean C. Thomas

    2017-01-01

    Biochar may be useful for restoring or revitalizing degraded forest soils and help with carbon sequestration, nutrient leaching losses, and reducing greenhouse gas emissions. However, biochar is not currently widely used on forested lands across North America. This chapter provides an overview of several biochar experiments conducted in North America and discusses the...

  5. BTU convergence spawning gas market opportunities in North America

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    The so-called BTU convergence of US electric power and natural gas sectors is spawning a boom in market opportunities in the US Northeast that ensures the region will be North America's fastest growing gas market. That's the view of Catherine Good Abbott, CEO of Columbia Gas Transmission Corp., who told a Ziff Energy conference in Calgary that US Northeast gas demand is expected to increase to almost 10 bcfd in 2000 and more than 12 bcfd in 2010 from about 8 bcfd in 1995 and only 3 bcfd in 1985. The fastest growth will be in the US Northeast's electrical sector, where demand for gas is expected to double to 4 bcfd in 2010 from about 2 bcfd in 1995. In other presentations at the Ziff Energy conference, speakers voiced concerns about the complexity and speed of the BTU convergence phenomenon and offered assurances about the adequacy of gas supplies in North American to meet demand growth propelled by the BTU convergence boom. The paper discusses the gas demand being driven by power utilities, the BTU convergence outlook, electric power demand, Canadian production and supply, and the US overview

  6. Updated Estimates of Glacier Mass Change for Western North America

    Science.gov (United States)

    Menounos, B.; Gardner, A. S.; Howat, I.; Berthier, E.; Dehecq, A.; Noh, M. J.; Pelto, B. M.

    2017-12-01

    Alpine glaciers are critical components in Western North America's hydrologic cycle. We use varied remotely-sensed datasets to provide updated mass change estimates for Region 2 of the Randolf Glacier Inventory (RGI-02 - all North American glaciers outside of Alaska). Our datasets include: i) aerial laser altimetry surveys completed over many thousands of square kilometers; and ii) multiple Terabytes of high resolution optical stereo imagery (World View 1-3 and Pleiades). Our data from the period 2014-2017 includes the majority of glaciers in RGI-02, specifically those ice masses in the Rocky Mountains (US and Canada), Interior Ranges in British Columbia and the Cascade Mountains (Washington). We co-registered and bias corrected the recent surface models to the Shuttle Radar Topographic Mapping (SRTM) data acquired in February, 2000. In British Columbia, our estimates of mass change are within the uncertainty estimates obtained for the period 1985-2000, but estimates from some regions indicate accelerated mass loss. Work is also underway to update glacier mass change estimates for glaciers in Washington and Montana. Finally, we use re-analysis data (ERA interim and ERA5) to evaluate the meteorological drivers that explain the temporal and spatial variability of mass change evident in our analysis.

  7. Deformation in D″ Beneath North America From Anisotropy

    Science.gov (United States)

    Nowacki, A. J.; Wookey, J.; Kendall, J. M.

    2009-12-01

    The lowermost few hundred kilometres of the Earth's mantle—known as D″—form the boundary between it and the core below, control the Earth's convective system, and are the site of probable large thermochemical heterogeneity. Seismic observations of D″ show a strong heterogeneity in seismic wave velocity and significant seismic anisotropy (the variation of wave speed with direction) are present in many parts of the region. On the basis of continuous regions of fast shear velocity (VS) anomalies in global models, it is also proposed as the resting place of subducted slabs, notably the Farallon beneath North America. A phase change of MgSiO3-perovskite (pv) to a post-perovskite (ppv) structure at near-core-mantle boundary (CMB) conditions is a compelling mechanism to explain the seismic features of D″. An outstanding question is how this and other mineral phases may deform to produce anisotropy, with different mechanisms possible. With knowledge either of mantle flow or which slip system is responsible for causing deformation, we can potentially determine the other with observations of the resulting seismic anisotropy. We investigate the dynamics at the CMB beneath North America using differential shear wave splitting in S and ScS phases from earthquakes of magnitude MW>5.5 in South and Central America, Hawaii the Mid-Atlantic Ridge and East Pacific Rise. They are detected on ~500 stations in North America, giving ~700 measurements of anisotropy in D″. We achieve this by correcting for anisotropy in the upper mantle (UM) beneath both the source and receiver. The measurements cover three regions beneath western USA, the Yucatan peninsula and Florida. In each case, two different, crossing ray paths are used, so that the style of anisotropy can be constrained—a single azimuth cannot distinguish differing cases. Our results showing ~1% anisotropy dependent on azimuth are not consistent with transverse isotropy with a vertical symmetry axis (VTI) anywhere. The

  8. Uncertainty in the Future of Seasonal Snowpack over North America.

    Science.gov (United States)

    McCrary, R. R.; Mearns, L.

    2017-12-01

    The uncertainty in future changes in seasonal snowpack (snow water equivalent, SWE) and snow cover extent (SCE) for North America are explored using the North American Regional Climate Change Assessment Program (NARCCAP) suite of regional climate models (RCMs) and their driving CMIP3 global circulation models (GCMs). The higher resolution of the NARCCAP RCMs is found to add significant value to the details of future projections of SWE in topographically complex regions such as the Pacific Northwest and the Rocky Mountains. The NARCCAP models also add detailed information regarding changes in the southernmost extent of snow cover. 11 of the 12 NARCCAP ensemble members contributed SWE output which we use to explore the uncertainty in future snowpack at higher resolution. In this study, we quantify the uncertainty in future projections by looking at the spread of the interquartile range of the different models. By mid-Century the RCMs consistently predict that winter SWE amounts will decrease over most of North America. The only exception to this is in Northern Canada, where increased moisture supply leads to increases in SWE in all but one of the RCMs. While the models generally agree on the sign of the change in SWE, there is considerable spread in the magnitude (absolute and percent) of the change. The RCMs also agree that the number of days with measureable snow on the ground is projected to decrease, with snow accumulation occurring later in the Fall/Winter and melting starting earlier in the Spring/Summer. As with SWE amount, spread across the models is large for changes in the timing of the snow season and can vary by over a month between models. While most of the NARCCAP models project a total loss of measurable snow along the southernmost edge of their historical range, there is considerable uncertainty about where this will occur within the ensemble due to the bias in snow cover extent in the historical simulations. We explore methods to increase our

  9. Ophthalmology in North America: Early Stories (1491-1801

    Directory of Open Access Journals (Sweden)

    Christopher T Leffler

    2017-07-01

    Full Text Available New World plants, such as tobacco, tomato, and chili, were held to have beneficial effects on the eyes. Indigenous healers rubbed or scraped the eyes or eyelids to treat inflammation, corneal opacities, and even eye irritation from smoke. European settlers used harsh treatments, such as bleeding and blistering, when the eyes were inflamed or had loss of vision with a normal appearance (gutta serena. In New Spain, surgery for corneal opacity was performed in 1601 and cataract couching in 1611. North American physicians knew of contralateral loss of vision after trauma or surgery (sympathetic ophthalmia, which they called “sympathy.” To date, the earliest identified cataract couching by a surgeon trained in the New World was performed in 1769 by John Bartlett of Rhode Island. The American Revolution negatively affected ophthalmology, as loyalist surgeons were expelled and others were consumed with wartime activities. After the war, cataract extraction was imported to America in earnest and academic development resumed. Charles F Bartlett, the son of John, performed cataract extraction but was also a “rapacious privateer.” In 1801, a doctor in the frontier territory of Kentucky observed anticholinergic poisoning by Datura stramonium (Jimsonweed and suggested that this agent be applied topically to dilate the pupil before cataract extraction. John Warren at Harvard preferred couching in the 1790s, but, after his son returned from European training, recommended treating angle closure glaucoma by lens extraction. Other eye procedures described or advertised in America before the 19th century included enucleation, resection of conjunctival lesions or periocular tumors, treatment of lacrimal fistula, and fitting of prosthetic eyes.

  10. Impact of North America on the aerosol composition in the North Atlantic free troposphere

    Directory of Open Access Journals (Sweden)

    M. I. García

    2017-06-01

    Full Text Available In the AEROATLAN project we study the composition of aerosols collected over  ∼  5 years at Izaña Observatory (located at  ∼  2400 m a.s.l. in Tenerife, the Canary Islands under the prevailing westerly airflows typical of the North Atlantic free troposphere at subtropical latitudes and midlatitudes. Mass concentrations of sub-10 µm aerosols (PM10 carried by westerly winds to Izaña, after transatlantic transport, are typically within the range 1.2 and 4.2 µg m−3 (20th and 80th percentiles. The main contributors to background levels of aerosols (PM10 within the 1st–50th percentiles  =  0.15–2.54 µg m−3 are North American dust (53 %, non-sea-salt sulfate (14 % and organic matter (18 %. High PM10 events (75th–95th percentiles  ≈  4.0–9.0 µg m−3 are prompted by dust (56 %, organic matter (24 % and non-sea-salt sulfate (9 %. These aerosol components experience a seasonal evolution explained by (i their spatial distribution in North America and (ii the seasonal shift of the North American outflow, which migrates from low latitudes in winter (∼  32° N, January–March to high latitudes in summer (∼  52° N, August–September. The westerlies carry maximum loads of non-sea-salt sulfate, ammonium and organic matter in spring (March–May, of North American dust from midwinter to mid-spring (February–May and of elemental carbon in summer (August–September. Our results suggest that a significant fraction of organic aerosols may be linked to sources other than combustion (e.g. biogenic; further studies are necessary for this topic. The present study suggests that long-term evolution of the aerosol composition in the North Atlantic free troposphere will be influenced by air quality policies and the use of soils (potential dust emitter in North America.

  11. Shaded Relief with Height as Color, North America

    Science.gov (United States)

    2003-01-01

    This image of North America was generated with data from the Shuttle Radar Topography Mission (SRTM). For this broad view the resolution of the data was first reduced to 30 arcseconds (about 928 meters north-south and 736 meters east-west in central North America), matching the best previously existing global digital topographic data set called GTOPO30. The data were then resampled to a Mercator projection with approximately square pixels (about one kilometer, or 0.6 miles, on each side). Even at this decreased resolution the variety of landforms comprising the North American continent is readily apparent.Active tectonics (structural deformation of the Earth's crust) along and near the Pacific -- North American plate boundary creates the great topographic relief seen along the Pacific coast. Earth's crustal plates converge in southern Mexico and in the northwest United States, melting the crust and producing volcanic cones. Along the California coast, the plates are sliding laterally past each other, producing a pattern of slices within the San Andreas fault system. And, where the plates are diverging, the crust appears torn apart as one huge tear along the Gulf of California (northwest Mexico), and as the several fractures comprising the Basin and Range province (in and around Nevada).Across the Great Plains, erosional patterns dominate, with streams channels surrounding and penetrating the remnants of older smooth slopes east of the Rocky Mountains. This same erosion process is exposing the bedrock structural patterns of the Black Hills in South Dakota and the Ozark Mountains in Arkansas. Lateral erosion and sediment deposition by the Mississippi River has produced the flatlands of the lower Mississippi Valley and the Mississippi Delta.To the north, evidence of the glaciers of the last ice age is widely found, particularly east of the Canadian Rocky Mountains and around the Great Lakes. From northeastern British Columbia, across Alberta, Saskatchewan, and

  12. Predicting Pleistocene climate from vegetation in North America

    Directory of Open Access Journals (Sweden)

    C. Loehle

    2007-01-01

    Full Text Available Climates at the Last Glacial Maximum have been inferred from fossil pollen assemblages, but these inferred climates are colder for eastern North America than those produced by climate simulations. It has been suggested that low CO2 levels could account for this discrepancy. In this study biogeographic evidence is used to test the CO2 effect model. The recolonization of glaciated zones in eastern North America following the last ice age produced distinct biogeographic patterns. It has been assumed that a wide zone south of the ice was tundra or boreal parkland (Boreal-Parkland Zone or BPZ, which would have been recolonized from southern refugia as the ice melted, but the patterns in this zone differ from those in the glaciated zone, which creates a major biogeographic anomaly. In the glacial zone, there are few endemics but in the BPZ there are many across multiple taxa. In the glacial zone, there are the expected gradients of genetic diversity with distance from the ice-free zone, but no evidence of this is found in the BPZ. Many races and related species exist in the BPZ which would have merged or hybridized if confined to the same refugia. Evidence for distinct southern refugia for most temperate species is lacking. Extinctions of temperate flora were rare. The interpretation of spruce as a boreal climate indicator may be mistaken over much of the region if the spruce was actually an extinct temperate species. All of these anomalies call into question the concept that climates in the zone south of the ice were extremely cold or that temperate species had to migrate far to the south. An alternate hypothesis is that low CO2 levels gave an advantage to pine and spruce, which are the dominant trees in the BPZ, and to herbaceous species over trees, which also fits the observed pattern. Thus climate reconstruction from pollen data is probably biased and needs to incorporate CO2 effects. Most temperate species could have survived across their current

  13. 75 FR 20390 - Robert Bosch LLC, Including On-Site Leased Workers From Bosch Management Services North America...

    Science.gov (United States)

    2010-04-19

    ...-site leased workers of Bosch Management Services North America, South Haven Community Hospital... leased workers of Bosch Management Services North America, South Haven Community Hospital, Huffmaster Inc..., Including On-Site Leased Workers From Bosch Management Services North America, South Haven Community...

  14. 75 FR 76037 - HAVI Logistics, North America a Subsidiary of HAVI Group, LP Including On-Site Leased Workers of...

    Science.gov (United States)

    2010-12-07

    ... Logistics, North America a Subsidiary of HAVI Group, LP Including On-Site Leased Workers of Express Personnel Services and the La Salle Network, Bloomingdale, IL; Havi Logistics, North America, Lisle, IL..., applicable to workers of HAVI Logistics, North America, a subsidiary of HAVI Group, LP, including on-site...

  15. 75 FR 8921 - Grant of Authority for Subzone Status; Brightpoint North America L.P. (Cell Phone Kitting and...

    Science.gov (United States)

    2010-02-26

    ... Status; Brightpoint North America L.P. (Cell Phone Kitting and Distribution) Indianapolis, IN Pursuant to... the cell phone kitting and distribution facilities of Brightpoint North America L.P., located in... cell phones at the facilities of Brightpoint North America L.P., located in Plainfield, Indiana...

  16. 75 FR 69470 - Tele Atlas North America, Inc., Currently Doing Business as Tom Tom Including Off-Site Workers...

    Science.gov (United States)

    2010-11-12

    ...,839B; TA-W-70,839C] Tele Atlas North America, Inc., Currently Doing Business as Tom Tom Including Off... Business as Tom Tom, Concord, MA; Tele Atlas North America, Inc. Currently Doing Business as Tom Tom, Detroit, MI; Tele Atlas North America, Inc. Currently Doing Business as Tom Tom, Redwood, CA; Amended...

  17. 77 FR 62535 - Hydro Aluminum North America, Inc., Midwest Region, Including On-Site Leased Workers From...

    Science.gov (United States)

    2012-10-15

    ... Aluminum North America, Inc., Midwest Region, Including On- Site Leased Workers From Employment Group, Aerotek, and Manpower, Kalamazoo, Michigan; Hydro Aluminum North America, Inc., Midwest Region, Including... Aluminum North America, Inc., Kalamazoo, Michigan. The subject worker group includes on-site leased workers...

  18. Ecosystem biophysical memory in the southwestern North America climate system

    International Nuclear Information System (INIS)

    Forzieri, G; Feyen, L; Vivoni, E R

    2013-01-01

    To elucidate the potential role of vegetation to act as a memory source in the southwestern North America climate system, we explore correlation structures of remotely sensed vegetation dynamics with precipitation, temperature and teleconnection indices over 1982–2006 for six ecoregions. We found that lagged correlations between vegetation dynamics and climate variables are modulated by the dominance of monsoonal or Mediterranean regimes and ecosystem-specific physiological processes. Subtropical and tropical ecosystems exhibit a one month lag positive correlation with precipitation, a zero- to one-month lag negative correlation with temperature, and modest negative effects of sea surface temperature (SST). Mountain forests have a zero month lag negative correlation with precipitation, a zero–one month lag negative correlation with temperature, and no significant correlation with SSTs. Deserts show a strong one–four month lag positive correlation with precipitation, a low zero–two month lag negative correlation with temperature, and a high four–eight month lag positive correlation with SSTs. The ecoregion-specific biophysical memories identified offer an opportunity to improve the predictability of land–atmosphere interactions and vegetation feedbacks onto climate. (letter)

  19. Bird collision impacts at wind turbines in eastern North America

    Energy Technology Data Exchange (ETDEWEB)

    Kerlinger, Paul; Curry, Richard; Guarnaccia, John [Curry and Kerlinger, LLC (United States)

    2011-07-01

    This paper discusses the incidence of bird collisions at wind turbines in Eastern North America. Modern wind turbines are high, with long, tubular towers. Bird fatality is analyzed and references to the relevant studies that have been done are given. 26 sites were investigated for turbine mortality in 2011 and these are shown on a map. 64 turbines were examined in Maple Ridge and it was seen that 4 birds were killed per turbine per year. The results demonstrated that no eagles were killed, there were no endangered species involved and there was no real deviation from site to site. More than 80,000 individual turbines were researched and more than $30 million spent on the study. Around 120,000 birds are killed per year, or an average of over 6 birds per turbine per year, in the United States. It is clear from the extensive research conducted that there are a lot of data on birds and turbines; the data show that songbirds are the most often affected.

  20. Demographic controls of aboveground forest biomass across North America.

    Science.gov (United States)

    Vanderwel, Mark C; Zeng, Hongcheng; Caspersen, John P; Kunstler, Georges; Lichstein, Jeremy W

    2016-04-01

    Ecologists have limited understanding of how geographic variation in forest biomass arises from differences in growth and mortality at continental to global scales. Using forest inventories from across North America, we partitioned continental-scale variation in biomass growth and mortality rates of 49 tree species groups into (1) species-independent spatial effects and (2) inherent differences in demographic performance among species. Spatial factors that were separable from species composition explained 83% and 51% of the respective variation in growth and mortality. Moderate additional variation in mortality (26%) was attributable to differences in species composition. Age-dependent biomass models showed that variation in forest biomass can be explained primarily by spatial gradients in growth that were unrelated to species composition. Species-dependent patterns of mortality explained additional variation in biomass, with forests supporting less biomass when dominated by species that are highly susceptible to competition (e.g. Populus spp.) or to biotic disturbances (e.g. Abies balsamea). © 2016 John Wiley & Sons Ltd/CNRS.

  1. School and community relations in North America: Creative tensions

    Science.gov (United States)

    Loughran, E.; Reed, H. B.

    1980-09-01

    School and community relations in North America reflect creative tensions between the conserving forces of schooling and the changing forces of community. During crisis periods community development needs may modify the school's focus on individual learner growth, but generally schools use the community to extend and enrich the traditional modes. School and community interactions are chiefly characterized by such settings as community schools, community education, adult education, home and school (PTA) associations, work-study programs, curriculum-community resource programs. Recent social forces are creating heightened tensions: cultural pluralism, reduced resources, Third World influences, international conflicts, personal alienation, population concerns, energy problems, community power issues. These forces are gradually shifting school and community concepts towards ones of education and community. Education goes well beyond schooling, including all agencies having an organized influence on community development: libraries, voluntary groups, unions, business, human service agencies, government units, as well as schools. This shift requires research to develop nonformal concepts and practices, along with formal pedagogy, to increase the positive impacts of educational networks on community, as well as individual, development. These new directions have not yet significantly modified the traditional meaning of school and community relations.

  2. Can coyotes affect deer populations in Southeastern North America?

    Energy Technology Data Exchange (ETDEWEB)

    Kilgo, J., C.; Ray, H., Scott; Ruth, Charles; Miller, Karl, V.

    2010-07-01

    ABSTRACT The coyote (Canis latrans) is a recent addition to the fauna of eastern North America, and in many areas coyote populations have been established for only a decade or two. Although coyotes are known predators of white-tailed deer (Odocoileus virginianus) in their historic range, effects this new predator may have on eastern deer populations have received little attention. We speculated that in the southeastern United States, coyotes may be affecting deer recruitment, and we present 5 lines of evidence that suggest this possibility. First, the statewide deer population in South Carolina has declined coincident with the establishment and increase in the coyote population. Second, data sets from the Savannah River Site (SRS) in South Carolina indicate a new mortality source affecting the deer population concurrent with the increase in coyotes. Third, an index of deer recruitment at SRS declined during the period of increase in coyotes. Fourth, food habits data from SRS indicate that fawns are an important food item for coyotes during summer. Finally, recent research from Alabama documented significant coyote predation on fawns there. Although this evidence does not establish cause and effect between coyotes and observed declines in deer recruitment, we argue that additional research should proactively address this topic in the region. We identified several important questions on the nature of the deer–coyote relationship in the East.

  3. Surface electric fields for North America during historical geomagnetic storms

    Science.gov (United States)

    Wei, Lisa H.; Homeier, Nichole; Gannon, Jennifer L.

    2013-01-01

    To better understand the impact of geomagnetic disturbances on the electric grid, we recreate surface electric fields from two historical geomagnetic storms—the 1989 “Quebec” storm and the 2003 “Halloween” storms. Using the Spherical Elementary Current Systems method, we interpolate sparsely distributed magnetometer data across North America. We find good agreement between the measured and interpolated data, with larger RMS deviations at higher latitudes corresponding to larger magnetic field variations. The interpolated magnetic field data are combined with surface impedances for 25 unique physiographic regions from the United States Geological Survey and literature to estimate the horizontal, orthogonal surface electric fields in 1 min time steps. The induced horizontal electric field strongly depends on the local surface impedance, resulting in surprisingly strong electric field amplitudes along the Atlantic and Gulf Coast. The relative peak electric field amplitude of each physiographic region, normalized to the value in the Interior Plains region, varies by a factor of 2 for different input magnetic field time series. The order of peak electric field amplitudes (largest to smallest), however, does not depend much on the input. These results suggest that regions at lower magnetic latitudes with high ground resistivities are also at risk from the effect of geomagnetically induced currents. The historical electric field time series are useful for estimating the flow of the induced currents through long transmission lines to study power flow and grid stability during geomagnetic disturbances.

  4. Outlook for natural gas liquids sales in North America

    International Nuclear Information System (INIS)

    Anderson, A.B.

    1991-01-01

    The outlook for natural gas liquids (NGL) markets in North America is forecast, with a focus on NGL sourced from Canada. The supply of NGL from Canada is first discussed, showing that Canadian NGL production is typically a function of natural gas production. Over the period ending in the year 2001, Canadian propane and butanes production is expected to peak at ca 275,000 bbl/d and ethane at ca 175,000 bbl/d. The processing, transport, and storage infrastructure for NGL in Canada has been regarded as being matured. A historical overview of the NGL market has shown large swings in demand, linked to such factors as crude oil prices and the drop in butanes demand caused by changes in gasoline specifications in the USA. On the other hand, oxygenates required for reformulated gasolines need butanes as a raw material for their manufacture, signifying a new market for butanes when such gasolines are mandated in clean air programs. Prospects for propane are good in the transportation market because of its clean burning properties. Prospects for expanding ethylene production are favorable to NGL producers; major Canadian petrochemical producers are located close to the source of ethane and petrochemical demand for ethane is forecast to increase by 40,000 bbl/d due to a new plant coming on line and to larger exports to the USA. Results of some forecasts of Canadian propane, butane, and ethane supply and demand are included. 8 figs

  5. In the spotlight: New hydro development in North America

    International Nuclear Information System (INIS)

    Barnes, M.J.

    1993-01-01

    1992 was a year of progress for many segments of the hydropower industry as developers worked to bring new projects on line. This industry overview features several of these projects and offers a preview of 1993 activity. The only operating privately owned hydroelectric project in Texas. The largest hydro plant in the province of Manitoba. The world's largest submersible hydroturbine-generator. These projects and others-completed and placed in service in 1992-can claim a special place in the history books. For each of the 31 hydro projects in North America that began operating in 1992, there's a unique story to tell. Each called upon the time, talent, commitment, ingenuity, and perseverance of those involved in their development. In aggregate, these projects contribute nearly 3,800 MW of clean, renewable electrical capacity that can be used efficiently and cost-effectively to help meet the power demands of customers in the US and Canada. Utilities, state agencies, municipalities, and independent power developers played roles in developing new hydro in 1992. We offer a sampling of their work to illustrate progress made in the past year

  6. Energy balances for Europe and North America 1970-2000

    International Nuclear Information System (INIS)

    1989-01-01

    This publication is based on the ECE Energy Data Bank collected by the Senior Advisers to ECE Governments on Energy, supplemented by other official data available to the secretariat. The Energy Data Base contains energy balances from 1960 to 1985 for the market economy countries of western Europe and North America and from 1965 to 1985 for the centrally planned economy countries of eastern Europe. During the first session of the Senior Advisers to ECE Governments on Energy held in 1979, countries decided to circulate a questionnaire on Selected Energy Issues covering the years 1973, 1978, 1980, 1985, 1990 and 2000 (ECE/ENERGY/2, para. 29). While the methodology for establishing the balances has been mutually agreed, the assumptions underlying each country's forecast are not necessarily comparable. At their fifth session held from 23 to 27 September 1985, the Senior Advisers to ECE Governments on Energy agreed to issue a second questionnaire to collect revised projections for the years 1990 and 2000 (ECE/ENERGY/11, para. 50(b)). Information received served as benchmarks to construct a time series from 1970 to 1985. Commodities listed include solid fossil fuels, petroleum fuels, gaseous fuels both natural and derived, nuclear energy, hydro- and geothermal energy, electricity, steam and hot water, energy derived from non-conventional energy sources (solar, wind, wave, tidal, etc.)

  7. A study of ayahuasca use in North America.

    Science.gov (United States)

    Harris, Rachel; Gurel, Lee

    2012-01-01

    Eighty-one subjects who used ayahuasca at least once in North America answered a lengthy set of open-ended questions and completed the 81-item After the Spiritual Experience Questionnaire. An additional 50 ayahuasca users were interviewed in person. The data for this study represent ayahuasca experience based on more than 2,267 ceremonies. A comparison group of 46 people attending a Catholic spiritual retreat weekend also completed the After the Spiritual Experience Questionnaire. A factor analysis of this questionnaire yielded three factors: Joy in Life, Relationship to the Sacred and Toxic Feelings. Although the ayahuasca users had significantly higher scores on the first two factors, the two groups had modest mean differences indicating a similar response to two very different spiritual experiences. This key finding strongly supports the view that ayahuasca users are engaged in an authentic process as spiritual in nature as that of the retreatants. The qualitative data revealed that ayahuasca users reduced their alcohol intake, ate healthier diets, enjoyed improved mood and greater self-acceptance and felt more loving and compassionate in their relationships. Seventy-four percent of the ayahuasca users said they had a relationship with and received ongoing guidance and support from the spirit of ayahuasca.

  8. Environmental concerns regarding electric power transmission in North America

    International Nuclear Information System (INIS)

    DeCicco, J.M.; Bernow, S.S.; Beyea, J.

    1992-01-01

    The electric utilities of North America have become ever more interconnected via transmission facilities, largely to insure reliability. Current policy discussions regarding transmission include calls for improved access, increased capacity, and deregulation to facilitate trade in electric power. From an environmental perspective, two issues have been notably absent in much of the debate: (1) a recognition of the full range of environmental impacts related to electricity transmission; and (2) the potential for end-use efficiency to address the reliability and economy requirements that motivate attention to transmission. This paper broaches these issues, starting with an elaboration of the environmental impacts, which range from global and regional effects to local concerns, including the potential health risks associated with electric and magnetic fields. We emphasize that transmission planning should occur as part of an integrated planning process, in which the environmental and social costs of various options are fully considered. We discuss the potential for end-use efficiency to lessen environmental impacts of both transmission and generation. We conclude that there is a need to ensure that environmental externalities and demand-side alternatives are adequately considered when transmission network expansions are proposed. (Author)

  9. Diversity in shortjaw cisco (Coregonus zenithicus) in North America

    Science.gov (United States)

    Todd, T.N.; Steinhilber, M.

    2002-01-01

    Shortjaw cisco (Coregonus zenithicus) exhibit morphological variability across their geographic range in North America and could comprise more than one distinct morph or taxon. To investigate this, principal components analysis was applied to a data set that consisted of four variables from nine localities. All data were obtained from digital images of the specimens and the excised first gill arch. Confidence ellipses (95%) about the means of bivariate distributions of the principal components revealed that some populations were distinct from the others, but a continuity of overlap clouded understanding of pattern among the variation. Most populations had more and longer gillrakers than shortjaw cisco from George Lake (Manitoba) and Basswood Lake (Ontario) that had fewer and shorter gillrakers. This analysis supports the existence of a short- and few-rakered morph and a long- and many-rakered morph. However, most populations of shortjaw cisco from the Great Lakes across Canada to the Arctic share a similar morphology and likely represent a single, widespread species.

  10. Boettger stoneware from North America and Europe; are they authentic

    Energy Technology Data Exchange (ETDEWEB)

    Swann, Charles P. E-mail: swann@bartol.udel.edu; Nelson, Christina H

    2000-03-01

    In the early 18th century, Johann Friedrich Boettger, an alchemist recently arrived in Dresden, was assigned to ceramic experimentation under the orders of Augustus the Strong, Elector of Saxony and King of Poland. The Elector and his advisors hoped to discover the secret of making hard paste porcelain like the wares imported into Europe from China and Japan. In 1706-1707, Boettger produced his first ceramic body, a red stoneware similar to the wares produced in Yixing, China. The first objects were made following the forms of chinese prototypes or European metalwork of the period. Recently, the authenticity of a number of 'Boettger' objects in various museums and private collections in North America and Europe has been questioned. To aide in resolving these questions several non-destructive analytical techniques have been employed, the most important being PIXE. This report is on an initial study of 25 objects with 16 elements from Al to Zr and Pb being analysed. The results strongly suggest three different groupings, one of objects from the Meissen factory during the 20th century, one from the work of Boettger himself early in the 18th century and one from an as yet unknown time period and site. The first two groups were previously identified by one of the authors (C.N.)

  11. Managing weather and climate risks to agriculture in North America, Central America and the Caribbean

    Directory of Open Access Journals (Sweden)

    Harlan D. Shannon

    2015-12-01

    Full Text Available In recent decades, numerous weather- and climate-related natural disasters have impacted North America, Central America, and the Caribbean, repeatedly demonstrating how vulnerable local agriculture is to extreme episodic events. Given this recent history, and expectations that the frequency and intensity of some episodic events will increase with climate change, it is becoming increasingly important for farmers to proactively manage weather and climate risks to agriculture to protect their livelihoods. Some farmers in this region already apply various strategies to help reduce weather and climate risks and uncertainties, including farming in multiple locations, diversifying crops and varieties, seeking alternative sources of income, and purchasing crop insurance. Such efforts often help farmers maintain a more stable income while also protecting and preserving the productivity of the land. Other farmers, however, have failed to implement basic risk management strategies despite the clear benefits. Reasons for these failures can be attributed to inadequate farmer education and training, a lack of tools to help facilitate the practical application of risk management concepts, and poor communications between the agrometeorological and farming communities. The agrometeorological community can help overcome these obstacles by building upon existing efforts that have successfully educated farmers about weather and climate risks to agriculture and have equipped farmers with the data, tools, and applications necessary to manage these risks. Farmer input is critical to preparing effective educational and training materials and developing user-friendly risk management tools. The agrometeorological community should solicit input from farmers regularly to ensure that farmers are obtaining the information necessary to effectively manage weather and climate risks to agriculture.

  12. A synthesis of ENSO effects on drylands in Australia, North America and South America

    Directory of Open Access Journals (Sweden)

    M. Holmgren

    2006-01-01

    Full Text Available Fundamentally, El Niño Southern Oscillation (ENSO is a climatic and oceanographic phenomenon, but it has profound effects on terrestrial ecosystems. Although the ecological effects of ENSO are becoming increasingly known from a wide range of terrestrial ecosystems (Holmgren et al., 2001, their impacts have been more intensively studied in arid and semiarid systems. In this brief communication, we summarize the main conclusions of a recent symposium on the effects of ENSO in these ecosystems, which was convened as part of the First Alexander von Humboldt International Conference on the El Niño Phenomenon and its Global Impact, in Guayaquil, Ecuador, from 16–20 May 2005. Participants in the symposium shared results and perspectives from research conducted in North and South America and Australia, regions where the ecological effects of ENSO have been studied in depth. Although the reports covered a wide array of organisms and ecological systems (Fig. 1, a recurring theme was the strong increase in rainfall associated with ENSO events in dry ecosystems (during the El Niño phase of the oscillation in the Americas and the La Niña phase in Australia. Because inter-annual variability in precipitation is such a strong determinant of productivity in arid and semiarid ecosystems, increased ENSO rainfall is crucial for plant recruitment, productivity and diversity in these ecosystems. Several long-term studies show that this pulse in primary productivity causes a subsequent increase in herbivores, followed by an increase in carnivores, with consequences for changes in ecosystem structure and functioning that can be quite complex.

  13. Is 137Cs Dating Becoming Obsolete in North America?

    Science.gov (United States)

    Drexler, J. Z.; Fuller, C.; Salas, A.

    2016-12-01

    Dating of wetland sediments and peat is routinely carried out using 137Cs and 210Pb analysis. Unlike 210Pb, 137Cs is an anthropogenic radionuclide with a history of fallout from nuclear weapons testing. 137Cs is used as a single time marker; its peak is coincident with the height of atmospheric nuclear testing in 1963/4. During its use in the 1970s-90s, 137Cs peaks were usually highly distinct in wetland sediments (e.g., see 137Cs peaks from Louisiana marshes in Feijtel et al., 1988). This enabled its use as a check for dates assigned to a profile by 210Pb and other methods. However, recently, the efficacy of 137Cs dating in North America has deteriorated. In this presentation, we will provide specific examples of 137Cs as well as 210Pb dating in wetland sediments/peats we collected between 2005 and 2015 in Maine, California, Virginia, North Carolina, South Carolina, and Washington. Two main reasons exist for this decline. First, 137Cs activities in our recent cores are 30-40 % of the original activities in 1963/4 due to decay of the original 137Cs in situ (half-life = 30.17 years) and no major new sources. This manifests in lower signal to noise ratio, with some peaks barely recognizable above the noise. Second, 137Cs peaks are much less distinct due to 137Cs migration through time independent of substrate (or sediment) particles. Migration of peaks has resulted in estimated accretion rates being systematically lower or higher than those derived from 210Pb dating. These issues with 137Cs dating have important implications because 137Cs is used with 210Pb dating or even alone to determine rates of recent wetland carbon accumulation. Such rates are required to enter wetland restoration projects into carbon markets and to document IPCC mandated reductions in carbon pollution. Our analysis shows that, although dating by 137Cs alone has always been highly tenuous, now it is especially contraindicated and should be disallowed for the purposes of carbon accounting.

  14. Mercury and methylmercury in aquatic sediment across western North America

    Science.gov (United States)

    Fleck, Jacob; Marvin-DiPasquale, Mark C.; Eagles-Smith, Collin A.; Ackerman, Joshua T.; Lutz, Michelle A; Tate, Michael T.; Alpers, Charles N.; Hall, Britt D.; Krabbenhoft, David P.; Eckley, Chris S.

    2016-01-01

    Large-scale assessments are valuable in identifying primary factors controlling total mercury (THg) and monomethyl mercury (MeHg) concentrations, and distribution in aquatic ecosystems. Bed sediment THg and MeHg concentrations were compiled for > 16,000 samples collected from aquatic habitats throughout the West between 1965 and 2013. The influence of aquatic feature type (canals, estuaries, lakes, and streams), and environmental setting (agriculture, forest, open-water, range, wetland, and urban) on THg and MeHg concentrations was examined. THg concentrations were highest in lake (29.3 ± 6.5 μg kg− 1) and canal (28.6 ± 6.9 μg kg− 1) sites, and lowest in stream (20.7 ± 4.6 μg kg− 1) and estuarine (23.6 ± 5.6 μg kg− 1) sites, which was partially a result of differences in grain size related to hydrologic gradients. By environmental setting, open-water (36.8 ± 2.2 μg kg− 1) and forested (32.0 ± 2.7 μg kg− 1) sites generally had the highest THg concentrations, followed by wetland sites (28.9 ± 1.7 μg kg− 1), rangeland (25.5 ± 1.5 μg kg− 1), agriculture (23.4 ± 2.0 μg kg− 1), and urban (22.7 ± 2.1 μg kg− 1) sites. MeHg concentrations also were highest in lakes (0.55 ± 0.05 μg kg− 1) and canals (0.54 ± 0.11 μg kg− 1), but, in contrast to THg, MeHg concentrations were lowest in open-water sites (0.22 ± 0.03 μg kg− 1). The median percent MeHg (relative to THg) for the western region was 0.7%, indicating an overall low methylation efficiency; however, a significant subset of data (n > 100) had percentages that represent elevated methylation efficiency (> 6%). MeHg concentrations were weakly correlated with THg (r2 = 0.25) across western North America. Overall, these results highlight the large spatial variability in sediment THg and MeHg concentrations throughout western North America and underscore the important roles that landscape and land

  15. Fishery intensification in small water bodies: a review for North America

    National Research Council Canada - National Science Library

    Moehl, John Frederic; Davies, William D

    1993-01-01

    .... Intensification is also achieved by enhancing water fertility through liming and fertilization. Case studies are presented representing contrasting climatic regions of North America while demonstrating similarities in management style...

  16. Perspectives on the Land Use History of North America: A Context for Understanding Our Changing Environment

    National Research Council Canada - National Science Library

    Sisk, Thomas

    1998-01-01

    ... between land use and landcover change. The authors provide the historical context for interpreting recent landcover change in several regions of North America and articulate the value of a comprehensive, continental land use history...

  17. SOIL AND WATER CONSERVATION POLICY APPROACHES IN NORTH AMERICA, EUROPE, AND AUSTRALIA. (R825761)

    Science.gov (United States)

    AbstractSoil and water conservation policies and programs in developed countries in North America, Europe, and Australia are examined in the context of their effectiveness for addressing environmental degradation associated with technology-intensive agricultural syste...

  18. Daymet: Daily Surface Weather Data on a 1-km Grid for North America, Version 2

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides Daymet output data as mosaicked gridded estimates of daily weather parameters for North America, including daily continuous surfaces...

  19. First report of the post-fire morel Morchella exuberans in eastern North America.

    Science.gov (United States)

    Miller, Andrew N; Raudabaugh, Daniel B; Iturriaga, Teresa; Matheny, P Brandon; Petersen, Ronald H; Hughes, Karen W; Gube, Matthias; Powers, Rob A; James, Timothy Y; O'Donnell, Kerry

    2017-01-01

    Reports of true morels (Morchella) fruiting on conifer burn sites are common in western North America where five different fire-adapted species of black morels (Elata Clade) have been documented based on multilocus phylogenetic analyses. Fruiting of post-fire morels in eastern North America, by comparison, are rare and limited to a report from Minnesota in 1977 and eastern Ontario in 1991. Here, nuc rDNA internal transcribed spacer (ITS1-5.8S-ITS2 = ITS) sequences were used to identify the post-fire morel that fruited in great abundance the year following the 2012 Duck Lake Fire in the Upper Peninsula of Michigan and after the 2016 large-scale fire in the Great Smoky Mountains National Park in Tennessee as M. exuberans. A preliminary phylogenetic analysis suggests that the collections from eastern North America may be more closely related to those from Europe than from western North America, Europe, and China.

  20. 75 FR 52981 - Bluescope Buildings North America, Including Workers Whose Unemployment Insurance (UI) Wages Are...

    Science.gov (United States)

    2010-08-30

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-73,758] Bluescope Buildings North America, Including Workers Whose Unemployment Insurance (UI) Wages Are Reported Through Butler Manufacturing Company, Laurinburg, NC; Amended Certification Regarding Eligibility To Apply for Worker...

  1. Daymet: Daily Surface Weather Data on a 1-km Grid for North America, Version 2

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides Daymet output data as mosaicked gridded estimates of daily weather parameters for North America, including continuous surfaces of day length,...

  2. 78 FR 30963 - Michelin North America, Incorporated, Grant of Petition for Decision of Inconsequential...

    Science.gov (United States)

    2013-05-23

    ...: Michelin North America, Inc. (MNA), has determined that certain Michelin brand passenger car replacement... ETRTO standard and the Tire and Rim Association (T&RA) standard, thus becoming noncompliant with the...

  3. Oral rabies vaccination in north america: opportunities, complexities, and challenges.

    Directory of Open Access Journals (Sweden)

    Dennis Slate

    Full Text Available Steps to facilitate inter-jurisdictional collaboration nationally and continentally have been critical for implementing and conducting coordinated wildlife rabies management programs that rely heavily on oral rabies vaccination (ORV. Formation of a national rabies management team has been pivotal for coordinated ORV programs in the United States of America. The signing of the North American Rabies Management Plan extended a collaborative framework for coordination of surveillance, control, and research in border areas among Canada, Mexico, and the US. Advances in enhanced surveillance have facilitated sampling of greater scope and intensity near ORV zones for improved rabies management decision-making in real time. The value of enhanced surveillance as a complement to public health surveillance was best illustrated in Ohio during 2007, where 19 rabies cases were detected that were critical for the formulation of focused contingency actions for controlling rabies in this strategically key area. Diverse complexities and challenges are commonplace when applying ORV to control rabies in wild meso-carnivores. Nevertheless, intervention has resulted in notable successes, including the elimination of an arctic fox (Vulpes lagopus rabies virus variant in most of southern Ontario, Canada, with ancillary benefits of elimination extending into Quebec and the northeastern US. Progress continues with ORV toward preventing the spread and working toward elimination of a unique variant of gray fox (Urocyon cinereoargenteus rabies in west central Texas. Elimination of rabies in coyotes (Canis latrans through ORV contributed to the US being declared free of canine rabies in 2007. Raccoon (Procyon lotor rabies control continues to present the greatest challenges among meso-carnivore rabies reservoirs, yet to date intervention has prevented this variant from gaining a broad geographic foothold beyond ORV zones designed to prevent its spread from the eastern US

  4. Internal variability of a dynamically downscaled climate over North America

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jiali; Bessac, Julie; Kotamarthi, Rao; Constantinescu, Emil; Drewniak, Beth

    2017-09-08

    This study investigates the internal variability (IV) of a regional climate model, and considers the impacts of horizontal resolution and spectral nudging on the IV. A 16-member simulation ensemble was conducted using the Weather Research Forecasting model for three model configurations. Ensemble members included simulations at spatial resolutions of 50 km and 12 km without spectral nudging and simulations at a spatial resolution of 12 km with spectral nudging. All the simulations were generated over the same domain, which covered much of North America. The degree of IV was measured as the spread between the individual members of the ensemble during the integration period. The IV of the 12 km simulation with spectral nudging was also compared with a future climate change simulation projected by the same model configuration. The variables investigated focus on precipitation and near-surface air temperature. While the IVs show a clear annual cycle with larger values in summer and smaller values in winter, the seasonal IV is smaller for a 50-km spatial resolution than for a 12-km resolution when nudging is not applied. Applying a nudging technique to the 12-km simulation reduces the IV by a factor of two, and produces smaller IV than the simulation at 50 km without nudging. Applying a nudging technique also changes the geographic distributions of IV in all examined variables. The IV is much smaller than the inter-annual variability at seasonal scales for regionally averaged temperature and precipitation. The IV is also smaller than the projected changes in air-temperature for the mid- and late 21st century. However, the IV is larger than the projected changes in precipitation for the mid- and late 21st century.

  5. Internal variability of a dynamically downscaled climate over North America

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jiali; Bessac, Julie; Kotamarthi, Rao; Constantinescu, Emil; Drewniak, Beth

    2017-09-08

    This study investigates the internal variability (IV) of a regional climate model, and considers the impacts of horizontal resolution and spectral nudging on the IV. A 16-member simulation ensemble was conducted using the Weather Research Forecasting model for three model configurations. Ensemble members included simulations at spatial resolutions of 50 and 12 km without spectral nudging and simulations at a spatial resolution of 12 km with spectral nudging. All the simulations were generated over the same domain, which covered much of North America. The degree of IV was measured as the spread between the individual members of the ensemble during the integration period. The IV of the 12 km simulation with spectral nudging was also compared with a future climate change simulation projected by the same model configuration. The variables investigated focus on precipitation and near-surface air temperature. While the IVs show a clear annual cycle with larger values in summer and smaller values in winter, the seasonal IV is smaller for a 50-km spatial resolution than for a 12-km resolution when nudging is not applied. Applying a nudging technique to the 12-km simulation reduces the IV by a factor of two, and produces smaller IV than the simulation at 50 km without nudging. Applying a nudging technique also changes the geographic distributions of IV in all examined variables. The IV is much smaller than the inter-annual variability at seasonal scales for regionally averaged temperature and precipitation. The IV is also smaller than the projected changes in air-temperature for the mid- and late twenty-first century. However, the IV is larger than the projected changes in precipitation for the mid- and late twenty-first century.

  6. Predicting grizzly bear density in western North America.

    Science.gov (United States)

    Mowat, Garth; Heard, Douglas C; Schwarz, Carl J

    2013-01-01

    Conservation of grizzly bears (Ursus arctos) is often controversial and the disagreement often is focused on the estimates of density used to calculate allowable kill. Many recent estimates of grizzly bear density are now available but field-based estimates will never be available for more than a small portion of hunted populations. Current methods of predicting density in areas of management interest are subjective and untested. Objective methods have been proposed, but these statistical models are so dependent on results from individual study areas that the models do not generalize well. We built regression models to relate grizzly bear density to ultimate measures of ecosystem productivity and mortality for interior and coastal ecosystems in North America. We used 90 measures of grizzly bear density in interior ecosystems, of which 14 were currently known to be unoccupied by grizzly bears. In coastal areas, we used 17 measures of density including 2 unoccupied areas. Our best model for coastal areas included a negative relationship with tree cover and positive relationships with the proportion of salmon in the diet and topographic ruggedness, which was correlated with precipitation. Our best interior model included 3 variables that indexed terrestrial productivity, 1 describing vegetation cover, 2 indices of human use of the landscape and, an index of topographic ruggedness. We used our models to predict current population sizes across Canada and present these as alternatives to current population estimates. Our models predict fewer grizzly bears in British Columbia but more bears in Canada than in the latest status review. These predictions can be used to assess population status, set limits for total human-caused mortality, and for conservation planning, but because our predictions are static, they cannot be used to assess population trend.

  7. Predicting grizzly bear density in western North America.

    Directory of Open Access Journals (Sweden)

    Garth Mowat

    Full Text Available Conservation of grizzly bears (Ursus arctos is often controversial and the disagreement often is focused on the estimates of density used to calculate allowable kill. Many recent estimates of grizzly bear density are now available but field-based estimates will never be available for more than a small portion of hunted populations. Current methods of predicting density in areas of management interest are subjective and untested. Objective methods have been proposed, but these statistical models are so dependent on results from individual study areas that the models do not generalize well. We built regression models to relate grizzly bear density to ultimate measures of ecosystem productivity and mortality for interior and coastal ecosystems in North America. We used 90 measures of grizzly bear density in interior ecosystems, of which 14 were currently known to be unoccupied by grizzly bears. In coastal areas, we used 17 measures of density including 2 unoccupied areas. Our best model for coastal areas included a negative relationship with tree cover and positive relationships with the proportion of salmon in the diet and topographic ruggedness, which was correlated with precipitation. Our best interior model included 3 variables that indexed terrestrial productivity, 1 describing vegetation cover, 2 indices of human use of the landscape and, an index of topographic ruggedness. We used our models to predict current population sizes across Canada and present these as alternatives to current population estimates. Our models predict fewer grizzly bears in British Columbia but more bears in Canada than in the latest status review. These predictions can be used to assess population status, set limits for total human-caused mortality, and for conservation planning, but because our predictions are static, they cannot be used to assess population trend.

  8. Economics issues - nuclear power generation in North America

    International Nuclear Information System (INIS)

    Jones, R.; Taylor, J.; Santucci, J.

    1996-01-01

    The structure of the US utility industry is in transition. Political, social, and economic factors are contributing to a rapid shift from a monopoly structure (captive markets, cost-plus prices, negotiated rate of return on capital) to a highly competitive one (choices for customers, prices determined by the market place, earnings based on market price less cost). The rate of change has been accelerating. For example, what just two years ago would have been thought of as highly unlikely -- competition for the individual electric customer -- is now part of the plan in California and other states. In our view, technology is at the root of many of these structural changes with more to come. Yet another round of technological change is afoot, involving even more efficient gas turbines, new methods of utilizing transmission lines, distributed generation, and new opportunities for electricity use and service. It can be argued that the restructuring of the marketplace reflects, in some measure, anticipation for these advances. For the foreseeable future, nuclear energy will continue to play a significant role in the generating grid of North America. However, new nuclear generation will be held to standards of competition that are dictated by market forces, and by advances in competing technologies for base load generation. It is important to understand these forces, and devise a response which ensures that nuclear energy will continue to provide a viable, competitive, and environmentally superior option for generating electricity in the 21st century. The EPRI Nuclear Power program is focused on achieving these goals. (author)

  9. The Carbon Budget of Coastal Waters of Eastern North America

    Science.gov (United States)

    Najjar, R.; Boyer, E. W.; Burdige, D.; Butman, D. E.; Cai, W. J.; Canuel, E. A.; Chen, R. F.; Friedrichs, M. A.; Griffith, P. C.; Herrmann, M.; Kemp, W. M.; Kroeger, K. D.; Mannino, A.; McCallister, S. L.; McGillis, W. R.; Mulholland, M. R.; Salisbury, J.; Signorini, S. R.; Tian, H.; Tzortziou, M.; Vlahos, P.; Wang, A. Z.; Zimmerman, R. C.; Pilskaln, C. H.

    2015-12-01

    Observations and the output of numerical and statistical models are synthesized to construct a carbon budget of the coastal waters of eastern North America. The domain extends from the head of tide to (roughly) the continental shelf break and from southern Florida to southern Nova Scotia. The domain area is 2% tidal wetlands, 19% estuarine open water, and 78% shelf water. Separate budgets are constructed for inorganic and organic carbon; for tidal wetlands, estuaries, and shelf waters; and for three main subregions: the Gulf of Maine, the Mid-Atlantic Bight, and the South Atlantic Bight. Net primary production for the study region is about 150 Tg C yr-1, with 12% occurring in tidal wetlands and 7% in estuaries. Though respiration and photosynthesis are nearly balanced in most systems and regions, tidal wetlands and shelf waters are each found to be net autotrophic whereas estuaries are net heterotrophic. The domain as a whole is a sink of 5 Tg C yr-1 of atmospheric CO2, with tidal wetlands and shelf waters taking up 10 Tg C yr-1 (split roughly equally) and estuaries releasing 5 Tg C yr-1 to the atmosphere. Carbon burial is about 3 Tg C yr-1, split roughly equally among tidal wetlands, estuaries, and shelf waters. Rivers supply 6-7 Tg C yr-1 to estuaries, about 2/3 of which is organic. Tidal wetlands supply an additional 4 Tg C yr-1 to estuaries, about half of which is organic. Carbon in organic and inorganic forms is exported from estuaries to shelf waters and from shelf waters to the open ocean. In summary, tidal wetlands and estuaries, though small in area, contribute substantially to the overall carbon budget of the region.

  10. Atmospheric wet deposition of mercury in North America

    Energy Technology Data Exchange (ETDEWEB)

    Sweet, C.W.; Prestbo, E.; Brunette, B.

    1999-07-01

    Currently, 39 states in the US and 5 Canadian provinces have issued advisories about the dangers of eating mercury-contaminated fish taken from waters within their boundaries. The problem is most severe in the Great Lakes region, the Northeast US states, the Canadian maritime provinces, and in south Florida where many lakes and streams contain fish with concentrations of 1 ppm or higher. For many rural and remote locations, atmospheric deposition is the primary source of mercury. In 1995, the National Atmospheric Deposition Program (NADP) initiated a program to monitor total mercury and methylmercury (MMHg) in wet deposition (rain and snow) in North America. In this program, the Mercury Deposition Network (MDN), individual monitoring sites are funded and operated by a variety of local, state, and federal agencies. However, sampling and analysis are coordinated through a central laboratory so that all of the samples are collected and analyzed using the same protocols. Weekly wet-only precipitation samples are collected using an all-glass sampling train and special handling techniques. Analysis is by cold vapor atomic fluorescence spectrometry using USEPA Method 1631 for total mercury. Nearly 40 MDN sites are in operation in 1999. Most of the sites are in the eastern US and Canada. During 1996 and 1997, the volume-weighted mean concentration of total mercury in precipitation collected at 22 sites ranged from 6.0 to 18.9 ng/L. Annual deposition varied between 2.1 and 25.3 {micro} g/m{sup 2}. The average weekly wet deposition of total mercury is more than three times higher in the summer (June-August) than in the winter (December-February). This increase is due to both higher amounts of precipitation and higher concentrations of mercury in precipitation during the summer. The highest values for mercury concentration in precipitation and wet deposition of mercury were measured in the southeastern US.

  11. Knowledge exchange for climate adaptation planning in western North America

    Science.gov (United States)

    Garfin, Gregg; Orr, Barron

    2015-04-01

    In western North America, the combination of sustained drought, rapid ecosystem changes, and land use changes associated with urban population growth has motivated concern among ecosystem managers about the implications of future climate changes for the landscapes which they manage. Through literature review, surveys, and workshop discussions, we assess the process of moving from concern, to planning, to action, with an emphasis on questions, such as: What are the roles of boundary organizations in facilitating knowledge exchange? Which practices lead to effective interactions between scientists, decision-makers, and knowledge brokers? While there is no "one size fits all" science communication method, the co-production of science and policy by research scientists, science translators, and decision-makers, as co-equals, is a resource intensive, but effective practice for moving adaptation planning forward. Constructive approaches make use of alliances with early adopters and opinion leaders, and make strong communication links between predictions, impacts and solutions. Resource managers need information on the basics of regional climate variability and global climate change, region-specific projections of climate changes and impacts, frank discussion of uncertainties, and opportunities for candid exploration of these topics with peers and subject experts. Research scientists play critical roles in adaptation planning discussions, because they assist resource managers in clarifying the cascade of interactions leading to potential impacts and, importantly, because decision-makers want to hear the information straight from the scientists conducting the research, which bolsters credibility. We find that uncertainty, formerly a topic to avoided, forms the foundation for constructive progress in adaptation planning. Candid exploration of the array of uncertainties, including those due to modeling, institutional, policy and economic factors, with practitioners, science

  12. Ground Motion Characteristics of Induced Earthquakes in Central North America

    Science.gov (United States)

    Atkinson, G. M.; Assatourians, K.; Novakovic, M.

    2017-12-01

    The ground motion characteristics of induced earthquakes in central North America are investigated based on empirical analysis of a compiled database of 4,000,000 digital ground-motion records from events in induced-seismicity regions (especially Oklahoma). Ground-motion amplitudes are characterized non-parametrically by computing median amplitudes and their variability in magnitude-distance bins. We also use inversion techniques to solve for regional source, attenuation and site response effects. Ground motion models are used to interpret the observations and compare the source and attenuation attributes of induced earthquakes to those of their natural counterparts. Significant conclusions are that the stress parameter that controls the strength of high-frequency radiation is similar for induced earthquakes (depth of h 5 km) and shallow (h 5 km) natural earthquakes. By contrast, deeper natural earthquakes (h 10 km) have stronger high-frequency ground motions. At distances close to the epicenter, a greater focal depth (which increases distance from the hypocenter) counterbalances the effects of a larger stress parameter, resulting in motions of similar strength close to the epicenter, regardless of event depth. The felt effects of induced versus natural earthquakes are also investigated using USGS "Did You Feel It?" reports; 400,000 reports from natural events and 100,000 reports from induced events are considered. The felt reports confirm the trends that we expect based on ground-motion modeling, considering the offsetting effects of the stress parameter versus focal depth in controlling the strength of motions near the epicenter. Specifically, felt intensity for a given magnitude is similar near the epicenter, on average, for all event types and depths. At distances more than 10 km from the epicenter, deeper events are felt more strongly than shallow events. These ground-motion attributes imply that the induced-seismicity hazard is most critical for facilities in

  13. Internal variability of a dynamically downscaled climate over North America

    Science.gov (United States)

    Wang, Jiali; Bessac, Julie; Kotamarthi, Rao; Constantinescu, Emil; Drewniak, Beth

    2017-09-01

    This study investigates the internal variability (IV) of a regional climate model, and considers the impacts of horizontal resolution and spectral nudging on the IV. A 16-member simulation ensemble was conducted using the Weather Research Forecasting model for three model configurations. Ensemble members included simulations at spatial resolutions of 50 and 12 km without spectral nudging and simulations at a spatial resolution of 12 km with spectral nudging. All the simulations were generated over the same domain, which covered much of North America. The degree of IV was measured as the spread between the individual members of the ensemble during the integration period. The IV of the 12 km simulation with spectral nudging was also compared with a future climate change simulation projected by the same model configuration. The variables investigated focus on precipitation and near-surface air temperature. While the IVs show a clear annual cycle with larger values in summer and smaller values in winter, the seasonal IV is smaller for a 50-km spatial resolution than for a 12-km resolution when nudging is not applied. Applying a nudging technique to the 12-km simulation reduces the IV by a factor of two, and produces smaller IV than the simulation at 50 km without nudging. Applying a nudging technique also changes the geographic distributions of IV in all examined variables. The IV is much smaller than the inter-annual variability at seasonal scales for regionally averaged temperature and precipitation. The IV is also smaller than the projected changes in air-temperature for the mid- and late twenty-first century. However, the IV is larger than the projected changes in precipitation for the mid- and late twenty-first century.

  14. Internal variability of a dynamically downscaled climate over North America

    Science.gov (United States)

    Wang, Jiali; Bessac, Julie; Kotamarthi, Rao; Constantinescu, Emil; Drewniak, Beth

    2018-06-01

    This study investigates the internal variability (IV) of a regional climate model, and considers the impacts of horizontal resolution and spectral nudging on the IV. A 16-member simulation ensemble was conducted using the Weather Research Forecasting model for three model configurations. Ensemble members included simulations at spatial resolutions of 50 and 12 km without spectral nudging and simulations at a spatial resolution of 12 km with spectral nudging. All the simulations were generated over the same domain, which covered much of North America. The degree of IV was measured as the spread between the individual members of the ensemble during the integration period. The IV of the 12 km simulation with spectral nudging was also compared with a future climate change simulation projected by the same model configuration. The variables investigated focus on precipitation and near-surface air temperature. While the IVs show a clear annual cycle with larger values in summer and smaller values in winter, the seasonal IV is smaller for a 50-km spatial resolution than for a 12-km resolution when nudging is not applied. Applying a nudging technique to the 12-km simulation reduces the IV by a factor of two, and produces smaller IV than the simulation at 50 km without nudging. Applying a nudging technique also changes the geographic distributions of IV in all examined variables. The IV is much smaller than the inter-annual variability at seasonal scales for regionally averaged temperature and precipitation. The IV is also smaller than the projected changes in air-temperature for the mid- and late twenty-first century. However, the IV is larger than the projected changes in precipitation for the mid- and late twenty-first century.

  15. Regional assessment of North America: Urbanization trends, biodiversity patterns, and ecosystem services

    Science.gov (United States)

    McPhearson, Timon; Auch, Roger F.; Alberti, Marina

    2013-01-01

    North America contains some of the most urbanized landscapes in the world. In the United States (U.S.) and Canada, approximately 80 % of the population is urban, with Mexico slightly less (Kaiser Family Foundation 2013). Population growth combined with economic growth has fueled recent urban land expansion in North America. Between 1970 and 2000, urban land area expanded at a rate of 3.31 % (Seto et al. 2011) creating unique challenges for conserving biodiversity and maintaining regional and local ecosystem services.

  16. Necrotizing Fasciitis Caused by Hypermucoviscous Klebsiella pneumoniae in a Filipino Female in North America

    Directory of Open Access Journals (Sweden)

    Ng, Daniel

    2014-12-01

    Full Text Available Necrotizing fasciitis caused by Klebsiella pneumoniae has been described in Southeast Asia, but has only recently begun to emerge in North America. The hypermucoviscous strain of K. pneumoniae is a particularly virulent strain known to cause devastatingly invasive infections, including necrotizing fasciitis. Here we present the first known case of necrotizing fasciitis caused by hypermucoviscous K. pneumoniae in North America. [West J Emerg Med. 2015;16(1:165–168.

  17. DNA from Pre-Clovis Human Coprolites in Oregon, North America

    DEFF Research Database (Denmark)

    Gilbert, M Thomas P; Jenkins, Dennis L; Götherstrom, Anders

    2008-01-01

    The timing of the first human migration into the Americas and its relation to the appearance of the Clovis technological complex in North America ca. 11-10.8 thousand radiocarbon years before present ((14)C ka B.P.) remains contentious. We establish that humans were present at Paisley 5 Mile Point...

  18. The first reported ceratopsid dinosaur from eastern North America (Owl Creek Formation, Upper Cretaceous, Mississippi, USA

    Directory of Open Access Journals (Sweden)

    Andrew A. Farke

    2017-05-01

    Full Text Available Ceratopsids (“horned dinosaurs” are known from western North America and Asia, a distribution reflecting an inferred subaerial link between the two landmasses during the Late Cretaceous. However, this clade was previously unknown from eastern North America, presumably due to limited outcrop of the appropriate age and depositional environment as well as the separation of eastern and western North America by the Western Interior Seaway during much of the Late Cretaceous. A dentary tooth from the Owl Creek Formation (late Maastrichtian of Union County, Mississippi, represents the first reported occurrence of Ceratopsidae from eastern North America. This tooth shows a combination of features typical of Ceratopsidae, including a double root and a prominent, blade-like carina. Based on the age of the fossil, we hypothesize that it is consistent with a dispersal of ceratopsids into eastern North America during the very latest Cretaceous, presumably after the two halves of North America were reunited following the retreat of the Western Interior Seaway.

  19. Biogeography of the Cicadas (Hemiptera: Cicadidae of North America, North of Mexico

    Directory of Open Access Journals (Sweden)

    Allen F. Sanborn

    2013-04-01

    Full Text Available We describe and illustrate the biogeography of the cicadas inhabiting continental North America, north of Mexico. Species distributions were determined through our collecting efforts as well as label data from more than 110 institutional collections. The status of subspecies is discussed with respect to their distributions. As we have shown over limited geographic areas, the distribution of individual species is related to the habitat in which they are found. We discuss the biogeography of the genera with respect to their phylogenetic relationships. California is the state with the greatest alpha diversity (89 species, 46.6% of taxa and unique species (35 species, 18.3% of taxa. Texas, Arizona, Colorado and Utah are the states with the next greatest alpha diversity with Texas, Arizona and Utah being next for unique species diversity. Maine, New Hampshire and Rhode Island are the states with the least amount of cicada diversity. Diversity is greatest in states and areas where there is a diversity of plant communities and habitats within these communities. Mountainous terrain also coincides with increases in diversity. Several regions of the focus area require additional collection efforts to fill in the distributions of several species.

  20. Population structure of Heterobasidion annosum from North America and Europe

    Science.gov (United States)

    W.J. Otrosina; T.E. Chase; F.W. Cobb; K. Korhonen

    1993-01-01

    Isolates of Heterobasidion annosum (Fr.) Bref. representing North American S and P and European S, P, and F intersterility groups were subjected to isozyme analysis.European S, P, and F groups had more variability than the North American S and P groups in expected heterozygosity, number of alleles per locus, and percent polymorphic loci.In contrast with the North...

  1. Human Population Decline in North America during the Younger Dryas

    Science.gov (United States)

    Anderson, D. G.; Goodyear, A. C.; Stafford, T. W., Jr.; Kennett, J.; West, A.

    2009-12-01

    dates. The decline at the YD onset was more than 50%, similar in magnitude to the decline in Clovis-Folsom point ratios. While calibration and sampling factors may affect the trends, this abrupt decline is large and requires explanation. SUMMARY: Even though correlation does not equate with causation, the coeval YD decline in both points and 14C dates appears linked to significant changes in climate and biota, as represented by the megafaunal extinction. While the causes of the YD remain controversial, a human population decline appears to have occurred, at least across parts of North America. Furthermore, the YD onset is associated with the abrupt replacement of Clovis by regional or subregional scale cultural traditions, potentially reflecting decreased range mobility and increased population isolation. Projectile point distributions and summed probability analyses, we argue, are potentially useful approaches for exploring demographic changes at regional scales.

  2. The later evolution of modern sport in Latin America: the North American influence.

    Science.gov (United States)

    Arbena, J L

    2001-01-01

    American impact on modern sports in Latin America overlaps geographically and chronologically with the European, especially British, impact. Principally baseball in the Caribbean basin, more recently basketball and volleyball across the hemisphere and occasionally American football in more limited areas illustrate a north-to-south movement executed by businessmen, educators, missionaries, military personnel, returning travelers (often students), sports entrepreneurs and television. Often initially supported by promoters of development within Latin America, this transfer has altered local recreational patterns and attracted Latin athletes to pursue careers in North America, provoking accusations of cultural imperialism and exploitation.

  3. Landscape‐level patterns in fawn survival across North America

    Science.gov (United States)

    Gingery, Tess M.; Diefenbach, Duane R.; Wallingford, Bret D.; Rosenberry, Christopher S.

    2018-01-01

    A landscape‐level meta‐analysis approach to examining early survival of ungulates may elucidate patterns in survival not evident from individual studies. Despite numerous efforts, the relationship between fawn survival and habitat characteristics remains unclear and there has been no attempt to examine trends in survival across landscape types with adequate replication. In 2015–2016, we radiomarked 98 white‐tailed deer (Odocoileus virginianus) fawns in 2 study areas in Pennsylvania. By using a meta‐analysis approach, we compared fawn survival estimates from across North America using published data from 29 populations in 16 states to identify patterns in survival and cause‐specific mortality related to landscape characteristics, predator communities, and deer population density. We modeled fawn survival relative to percentage of agricultural land cover and deer density. Estimated average survival to 3–6 months of age was 0.414 ± 0.062 (SE) in contiguous forest landscapes (no agriculture) and for every 10% increase in land area in agriculture, fawn survival increased 0.049 ± 0.014. We classified cause‐specific mortality as human‐caused, natural (excluding predation), and predation according to agriculturally dominated, forested, and mixed (i.e., both agricultural and forest cover) landscapes. Predation was the greatest source of mortality in all landscapes. Landscapes with mixed forest and agricultural cover had greater proportions and rates of human‐caused mortalities, and lower proportions and rates of mortality due to predators, when compared to forested landscapes. Proportion and rate of natural deaths did not differ among landscapes. We failed to detect any relationship between fawn survival and deer density. The results highlight the need to consider multiple spatial scales when accounting for factors that influence fawn survival. Furthermore, variation in mortality sources and rates among landscapes indicate the potential for

  4. Performance of salmon fishery portfolios across western North America.

    Science.gov (United States)

    Griffiths, Jennifer R; Schindler, Daniel E; Armstrong, Jonathan B; Scheuerell, Mark D; Whited, Diane C; Clark, Robert A; Hilborn, Ray; Holt, Carrie A; Lindley, Steven T; Stanford, Jack A; Volk, Eric C

    2014-12-01

    Quantifying the variability in the delivery of ecosystem services across the landscape can be used to set appropriate management targets, evaluate resilience and target conservation efforts. Ecosystem functions and services may exhibit portfolio-type dynamics, whereby diversity within lower levels promotes stability at more aggregated levels. Portfolio theory provides a framework to characterize the relative performance among ecosystems and the processes that drive differences in performance. We assessed Pacific salmon Oncorhynchus spp. portfolio performance across their native latitudinal range focusing on the reliability of salmon returns as a metric with which to assess the function of salmon ecosystems and their services to humans. We used the Sharpe ratio (e.g. the size of the total salmon return to the portfolio relative to its variability (risk)) to evaluate the performance of Chinook and sockeye salmon portfolios across the west coast of North America. We evaluated the effects on portfolio performance from the variance of and covariance among salmon returns within each portfolio, and the association between portfolio performance and watershed attributes. We found a positive latitudinal trend in the risk-adjusted performance of Chinook and sockeye salmon portfolios that also correlated negatively with anthropogenic impact on watersheds (e.g. dams and land-use change). High-latitude Chinook salmon portfolios were on average 2·5 times more reliable, and their portfolio risk was mainly due to low variance in the individual assets. Sockeye salmon portfolios were also more reliable at higher latitudes, but sources of risk varied among the highest performing portfolios. Synthesis and applications . Portfolio theory provides a straightforward method for characterizing the resilience of salmon ecosystems and their services. Natural variability in portfolio performance among undeveloped watersheds provides a benchmark for restoration efforts. Locally and regionally

  5. Avian Influenza Risk Surveillance in North America with Online Media.

    Directory of Open Access Journals (Sweden)

    Colin Robertson

    Full Text Available The use of Internet-based sources of information for health surveillance applications has increased in recent years, as a greater share of social and media activity happens through online channels. The potential surveillance value in online sources of information about emergent health events include early warning, situational awareness, risk perception and evaluation of health messaging among others. The challenge in harnessing these sources of data is the vast number of potential sources to monitor and developing the tools to translate dynamic unstructured content into actionable information. In this paper we investigated the use of one social media outlet, Twitter, for surveillance of avian influenza risk in North America. We collected AI-related messages over a five-month period and compared these to official surveillance records of AI outbreaks. A fully automated data extraction and analysis pipeline was developed to acquire, structure, and analyze social media messages in an online context. Two methods of outbreak detection; a static threshold and a cumulative-sum dynamic threshold; based on a time series model of normal activity were evaluated for their ability to discern important time periods of AI-related messaging and media activity. Our findings show that peaks in activity were related to real-world events, with outbreaks in Nigeria, France and the USA receiving the most attention while those in China were less evident in the social media data. Topic models found themes related to specific AI events for the dynamic threshold method, while many for the static method were ambiguous. Further analyses of these data might focus on quantifying the bias in coverage and relation between outbreak characteristics and detectability in social media data. Finally, while the analyses here focused on broad themes and trends, there is likely additional value in developing methods for identifying low-frequency messages, operationalizing this

  6. Performance of salmon fishery portfolios across western North America

    Science.gov (United States)

    Griffiths, Jennifer R; Schindler, Daniel E; Armstrong, Jonathan B; Scheuerell, Mark D; Whited, Diane C; Clark, Robert A; Hilborn, Ray; Holt, Carrie A; Lindley, Steven T; Stanford, Jack A; Volk, Eric C

    2014-01-01

    Quantifying the variability in the delivery of ecosystem services across the landscape can be used to set appropriate management targets, evaluate resilience and target conservation efforts. Ecosystem functions and services may exhibit portfolio-type dynamics, whereby diversity within lower levels promotes stability at more aggregated levels. Portfolio theory provides a framework to characterize the relative performance among ecosystems and the processes that drive differences in performance. We assessed Pacific salmon Oncorhynchus spp. portfolio performance across their native latitudinal range focusing on the reliability of salmon returns as a metric with which to assess the function of salmon ecosystems and their services to humans. We used the Sharpe ratio (e.g. the size of the total salmon return to the portfolio relative to its variability (risk)) to evaluate the performance of Chinook and sockeye salmon portfolios across the west coast of North America. We evaluated the effects on portfolio performance from the variance of and covariance among salmon returns within each portfolio, and the association between portfolio performance and watershed attributes. We found a positive latitudinal trend in the risk-adjusted performance of Chinook and sockeye salmon portfolios that also correlated negatively with anthropogenic impact on watersheds (e.g. dams and land-use change). High-latitude Chinook salmon portfolios were on average 2·5 times more reliable, and their portfolio risk was mainly due to low variance in the individual assets. Sockeye salmon portfolios were also more reliable at higher latitudes, but sources of risk varied among the highest performing portfolios. Synthesis and applications. Portfolio theory provides a straightforward method for characterizing the resilience of salmon ecosystems and their services. Natural variability in portfolio performance among undeveloped watersheds provides a benchmark for restoration efforts. Locally and regionally

  7. Synchrony in the snowshoe hare cycle in Northwestern North America, 1970-2012

    Science.gov (United States)

    C.J. Krebs; K. Kielland; J.P Bryant; M. O' Donoghue; F. Doyle; C. McIntyre; D. DiFolco; N. Berg; S. Carriere; R. Boonstra; S. Boutin; A. J. Kenney; D. G. Reid; K. Bodony; J. Putera; H. K. Timm; T. Burke.

    2013-01-01

    Snowshoe hares (Lepus americanus Erxleben, 1777) fluctuate in 9–10 year cycles throughout much of their North American range. Regional synchrony has been assumed to be the rule for these cycles, so that hare populations in virtually all of northwestern North America have been assumed to be in phase. We gathered qualitative and quantitative data on...

  8. Biological control of emerald ash borer in North America: current progress and potential for success

    Science.gov (United States)

    Jian J. Duan; Leah S. Bauer; Juli R. Gould; Jonathan P. Lelito

    2012-01-01

    The emerald ash borer (EAB) (Agrilus planipennis), a buprestid native to north-east Asia, was first discovered in North America near Detroit in 2002. EAB has since spread to at least 15 U.S. States and two Canadian provinces, threatening the existence of native ash trees (Fraxinus spp.). A classical biocontrol program was initiated...

  9. Ecosystem carbon dioxide fluxes after disturbance in forests of North America

    Science.gov (United States)

    B. D. Amiro; A. G. Barr; J. G. Barr; T. A. Black; R. Bracho; al. et.

    2010-01-01

    [1] Disturbances are important for renewal of North American forests. Here we summarize more than 180 site years of eddy covariance measurements of carbon dioxide flux made at forest chronosequences in North America. The disturbances included standreplacing fire (Alaska, Arizona, Manitoba, and Saskatchewan) and harvest (British Columbia, Florida, New Brunswick, Oregon...

  10. Recent Trends in Soil Science and Agronomy Research in the Northern Great Plains of North America

    Science.gov (United States)

    The book “Recent Trends in Soil Science and Agronomy Research in the Northern Great Plains of North America” summarizes published research in soil science and agronomy from various field experiments conducted in the soil-climatic/agro-ecological regions of the Northern Great Plains of North America....

  11. Health outcomes among HIV-positive Latinos initiating antiretroviral therapy in North America versus Central and South America

    Science.gov (United States)

    Cesar, Carina; Koethe, John R; Giganti, Mark J; Rebeiro, Peter; Althoff, Keri N; Napravnik, Sonia; Mayor, Angel; Grinsztejn, Beatriz; Wolff, Marcelo; Padgett, Denis; Sierra-Madero, Juan; Gotuzzo, Eduardo; Sterling, Timothy R; Willig, James; Levison, Julie; Kitahata, Mari; Rodriguez-Barradas, Maria C; Moore, Richard D; McGowan, Catherine; Shepherd, Bryan E; Cahn, Pedro

    2016-01-01

    Introduction Latinos living with HIV in the Americas share a common ethnic and cultural heritage. In North America, Latinos have a relatively high rate of new HIV infections but lower rates of engagement at all stages of the care continuum, whereas in Latin America antiretroviral therapy (ART) services continue to expand to meet treatment needs. In this analysis, we compare HIV treatment outcomes between Latinos receiving ART in North America versus Latin America. Methods HIV-positive adults initiating ART at Caribbean, Central and South America Network for HIV (CCASAnet) sites were compared to Latino patients (based on country of origin or ethnic identity) starting treatment at North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) sites in the United States and Canada between 2000 and 2011. Cox proportional hazards models compared mortality, treatment interruption, antiretroviral regimen change, virologic failure and loss to follow-up between cohorts. Results The study included 8400 CCASAnet and 2786 NA-ACCORD patients initiating ART. CCASAnet patients were younger (median 35 vs. 37 years), more likely to be female (27% vs. 20%) and had lower nadir CD4 count (median 148 vs. 195 cells/µL, p<0.001 for all). In multivariable analyses, CCASAnet patients had a higher risk of mortality after ART initiation (adjusted hazard ratio (AHR) 1.61; 95% confidence interval (CI): 1.32 to 1.96), particularly during the first year, but a lower hazard of treatment interruption (AHR: 0.46; 95% CI: 0.42 to 0.50), change to second-line ART (AHR: 0.56; 95% CI: 0.51 to 0.62) and virologic failure (AHR: 0.52; 95% CI: 0.48 to 0.57). Conclusions HIV-positive Latinos initiating ART in Latin America have greater continuity of treatment but are at higher risk of death than Latinos in North America. Factors underlying these differences, such as HIV testing, linkage and access to care, warrant further investigation. PMID:26996992

  12. Linking biotic homogenization to habitat type, invasiveness and growth form of naturalized alien plants in North America

    Science.gov (United States)

    Hong Qian; Qinfeng. Guo

    2010-01-01

    Aim Biotic homogenization is a growing phenomenon and has recently attracted much attention. Here, we analyse a large dataset of native and alien plants in North America to examine whether biotic homogenization is related to several ecological and biological attributes. Location North America (north of Mexico). Methods We assembled...

  13. Winter Precipitation in North America and the Pacific-North America Pattern in GEOS-S2Sv2 Seasonal Hindcast

    Science.gov (United States)

    Li, Zhao; Molod, Andrea; Schubert, Siegfried

    2018-01-01

    Reliable prediction of precipitation remains one of the most pivotal and complex challenges in seasonal forecasting. Previous studies show that various large-scale climate modes, such as ENSO, PNA and NAO play significant role in winter precipitation variability over the Northern America. The influences are most pronounced in years of strong indices of such climate modes. This study evaluates model bias, predictability and forecast skills of monthly winter precipitation in GEOS5-S2S 2.0 retrospective forecast from 1981 to 2016, with emphasis on the forecast skill of precipitation over North America during the extreme events of ENSO, PNA and NAO by applying EOF and composite analysis.

  14. Radiotherapy for invasive breast cancer in North America and Europe: Results of a survey

    International Nuclear Information System (INIS)

    Ceilley, Elizabeth; Jagsi, Reshma; Goldberg, Saveli; Grignon, Laurent; Kachnic, Lisa; Powell, Simon; Taghian, Alphonse

    2005-01-01

    Purpose: To document and explain the current radiotherapeutic management of invasive breast cancer in North America and Europe. We also identified a number of areas of agreement, as well as controversy, toward which additional clinical research should be directed. Methods and materials: An original survey questionnaire was developed to assess radiation oncologists' self-reported management of breast cancer. The questionnaire was administered to physician members of the American Society for Therapeutic Radiology and Oncology and the European Society for Therapeutic Radiology and Oncology. We present the results of the comparative analysis of 702 responses from North America and 435 responses from Europe. Results: Several areas of national and international controversy were identified, including the selection of appropriate candidates for postmastectomy radiation therapy (RT) and the appropriate management of the regional lymph nodes after mastectomy, as well as after lumpectomy. Only 40.7% and 36.1% of respondents would use postmastectomy RT in patients with 1-3 positive lymph nodes in North America and Europe, respectively. Sentinel lymph node biopsy was offered more frequently by North American than European respondents (p < 0.0001) and more frequently by academic than nonacademic respondents in North America (p < 0.05). The average radiation fraction size was larger in Europe than in North America (p < 0.01). European respondents offered RT to the internal mammary chain more often than did the North American respondents (p < 0.001). North American respondents were more likely to offer RT to the supraclavicular fossa (p < 0.001) and axilla (p < 0.01). Conclusion: Marked differences were found in physician opinions regarding the management of breast cancer, with statistically significant international differences in patterns of care. This survey highlighted areas of controversy, providing support for international randomized trials to optimize the RT management of

  15. Wind Powering America: The Next Steps in North Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Banks, Jennifer L. [North Carolina Solar Center; Scanlin, Dennis [Appalachian State University; Quinlan, Paul [North Carolina Sustainable Energy Association

    2013-06-18

    The goal of this project is to apply the WPA’s proactive outreach strategy to the problem of educating the public about the likely transmission infrastructure developments concomitant to the significant development of wind energy resources in North Carolina. Given the lead time to develop significant new transmission infrastructure (5-10 years), it is critical to begin this outreach work today, so that wind resources can be developed to adequately meet the 20% by 2030 goal in the mid- to long-term (10-20 years). The project team planned to develop a transmission infrastructure outreach campaign for North Carolina by: (1) convening a utility interest group (UIG) of the North Carolina Wind Working Group (NC WWG) consisting of electric utilities in the state and the Southeast; and (2) expanding outreach to local and state government officials in North Carolina.

  16. Late Cretaceous restructuring of terrestrial communities facilitated the end-Cretaceous mass extinction in North America.

    Science.gov (United States)

    Mitchell, Jonathan S; Roopnarine, Peter D; Angielczyk, Kenneth D

    2012-11-13

    The sudden environmental catastrophe in the wake of the end-Cretaceous asteroid impact had drastic effects that rippled through animal communities. To explore how these effects may have been exacerbated by prior ecological changes, we used a food-web model to simulate the effects of primary productivity disruptions, such as those predicted to result from an asteroid impact, on ten Campanian and seven Maastrichtian terrestrial localities in North America. Our analysis documents that a shift in trophic structure between Campanian and Maastrichtian communities in North America led Maastrichtian communities to experience more secondary extinction at lower levels of primary production shutdown and possess a lower collapse threshold than Campanian communities. Of particular note is the fact that changes in dinosaur richness had a negative impact on the robustness of Maastrichtian ecosystems against environmental perturbations. Therefore, earlier ecological restructuring may have exacerbated the impact and severity of the end-Cretaceous extinction, at least in North America.

  17. Projected hydrogen cost from methane reforming for North America 2015-2050

    International Nuclear Information System (INIS)

    Vanderveen, K.; Lutz, A.; Klebanoff, L.; Drennen, T.; Keller, J.; Drennen, T.; Kamery, W.

    2006-01-01

    The Hydrogen Futures Simulation Model (H 2 Sim) was used to project the cost for hydrogen at the point of sale to light duty vehicles for distributed, small-scale steam methane reforming. Projections cover the period from 2010-2050 in North America, and take into account assumptions about the quantity of recoverable natural gas remaining in North America. We conclude that there is a window for distributed reforming to play a positive role in supplying a H 2 fuel infrastructure, but this window is closing rapidly. The analysis assumes that production from natural gas reserves in North America will peak sometime before 2050 and demand will cause the price to rise after the peak of production in a manner consistent with Hotelling's model. We consider three scenarios for when the peak occurs, and evaluate the impact on the cost of hydrogen fuel produced via distributed small scale reforming in these three scenarios. (authors)

  18. Making full use of wind power potential in North America -- possibilities

    Energy Technology Data Exchange (ETDEWEB)

    Guillaud, Christian

    2010-09-15

    The anticipated increase in electrical load in North America up to the year 2050 will be at least 50%. Wind potential in North America is enormous, well in excess of the expected requirements. However, the amount of wind capacity, which can be directly connected to a grid is limited to 20% of the installed capacity because of technical constraints. Technologies to enable full wind potential to be harnessed still need to be developed; they will consist in storing wind energy in hydroelectric reservoirs or generating hydrogen. However, the resulting cost of electricity will be somewhat higher than present.

  19. Systematics, Phylogeny, and Distribution of Acer (maples) in the Cenozoic of Western North America

    OpenAIRE

    Wolfe, Jack A.; Tanai, Toshimasa

    1987-01-01

    The known fossil fruits and leaves of Acer from western North America represent 91 species and 28 sections, 12 of which are extinct and are described as new sections of Acer. Sixty-four species are described as new, 2 new combinations are proposed, and 6 species are left unnamed; 21 have been previously described. The most diverse sections of Acer in the Tertiary of western North America are the extinct Glabroidea (at least 13 species), Negundo (9 species), Macrophylla (8 species), and Erioca...

  20. Sommelier Suggestions: The Arthroscopy Association of North America Annual Meeting Inspires a Content Collection Worth Tasting.

    Science.gov (United States)

    Hunt, Timothy J; Brand, Jefferson C; Provencher, Matthew T; Rossi, Michael J; Lubowitz, James H

    2017-05-01

    The 2017 Arthroscopy Association of North America Annual Meeting Program inspires a Content Collection of Arthroscopy journal articles worthy of review. A foundation of a credible podium presentation is the published medical literature. Your Editors thus suggest recent publications that seem particularly relevant in the context of the 2017 annual meeting. Consider these articles as one would a suggestion for a good glass of wine to complement a delicious meal. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  1. Genetic distinctions between autoimmune hepatitis in Italy and North America.

    Science.gov (United States)

    Muratori, Paolo; Czaja, Albert-J; Muratori, Luigi; Pappas, Georgios; Maccariello, Silvana; Cassani, Fabio; Granito, Alessandro; Ferrari, Rodolfo; Mantovani, Vilma; Lenzi, Marco; Bianchi, Francesco-B

    2005-03-28

    Our goals were to analyze the known genetic predispositions for autoimmune hepatitis (AIH) in AIH Italian population and to compare them with North American counterparts. Human leukocyte antigens (HLA) B8, C7, DR3, DR4, DR7, DR11, DR13, DQ2 and the B8-DR3-DQ2 phenotype were determined by microlymphocytotoxicity and polymerase chain reaction in 74 Italian patients (57 with type 1 and 17 with type 2 AIH) and 149 North American patients with type 1 AIH, and in adequate controls. B8-DR3-DQ2 occurred more frequently in Italian patients with type 1 AIH than in Italian controls (30% vs 7%, P<0.0001), but less frequently than in North American counterparts (30% vs 48%, P = 0.02). DR4 occurred less frequently in Italian patients with type 1 AIH (23% vs 43%, P = 0.01) and in controls (16% vs 34%, P = 0.0003) than in North American counterparts. No differences were found in alleles' frequency between type 1 and type 2 Italian AIH patients. DR11 had a frequency lower in type 1 Italian AIH patients than controls (17% vs 35%, P = 0.01). HLA DR4 is not associated with AIH in Italy. The known HLA risk factors for AIH occur similarly in Italian patients with type 1 and type 2 AIH, and they are less frequent than in North American patients. B8-DR3-DQ2 is the predominant phenotype of type 1 AIH also in Italy, and HLA DR11 may be a regionally distinctive protective factor against type 1 AIH.

  2. Comparison of dental education and professional development between mainland China and North America.

    Science.gov (United States)

    Wu, Z Y; Zhang, Z Y; Jiang, X Q; Guo, L

    2010-05-01

    Different educational and professional developments within the dental field create different sets of missions, norms, and practices regarding dental diseases and their appropriate treatment. This review has addressed differences in dental education and professional development between mainland China and North America. Many factors influence the choice of model and it is very difficult to predict which model will become predominant. However, there is growing sentiment that the independent faculty model in North America is logical and superior to the model, which 'integrates' dental and medical education in mainland China. Many North America dental schools place a high priority on preclinical and clinical training in the curriculum in order to expose students to patient oral health needs and systemic dental problems much earlier than in mainland China. North America dental schools promote and embrace students self-learning skills by the use of PBL, CRL, and TRAD education methodologies and new e-based technologies and approaches whereby students learn rather than are taught. In mainland China, the traditional lecture-based format is still employed in the majority of dental schools; however, strategies to enhance students self-learning skills is increasingly utilised in most well-known Chinese dental schools. The Chinese dental education model, which treats dentistry as a sub-specialty of medicine, has brought about fundamental differences, with the dentist functioning essentially as a stomatologist. For example, China has built up a large oral and maxillofacial surgery society, and craniofacial surgery is performed to a much broader extent by Chinese dentists than by most North American counterparts. In North America, dentists engage in full-time work, attend continuing training/education programmes, belong to an association, gain legal status, and construct a code of ethics emphasising the quality of care delivered to the public. Currently, continuing dental

  3. The rebirth of natural gas industry in North America

    International Nuclear Information System (INIS)

    Ridgley, R.

    1994-01-01

    In seventies years united states of america made a strict regulation of gas prices; as a matter of results, producers were discouraged and did not engaged themselves in gad prospecting and production. In eighties years began the deregulation and that what gave to producers the stimulation to prospect and produce. It is necessary to increase the efficiency of gas and then the gas industry will develop more and more. An other point made to favour gas industry is the performance from an ecological point of view. It is easy to understand why gas industry has a development three times more important than others energy sources

  4. 76 FR 67406 - Approval for Expanded Manufacturing Authority; Foreign-Trade Subzone 158D Nissan North America...

    Science.gov (United States)

    2011-11-01

    ... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1794] Approval for Expanded Manufacturing Authority; Foreign-Trade Subzone 158D Nissan North America, Inc.; (Motor Vehicles) Canton, MS...), the Foreign-Trade Zones Board (the Board) adopts the following Order. Whereas, Nissan North America...

  5. Conservation and sustainable use of medicinal and aromatic products in North America: Are there really lessons to be learned?

    Science.gov (United States)

    A. L. Hammett; James L. Chamberlain

    2002-01-01

    This paper discusses the legacy of nontimber forest products (NTFPs) and, more specifically, medicinal plant use in North America. It also discusses briefly MAP markets both in North America and throughout the world, and describes the constraints to the sustainable use and development of MAP resources. Lastly, the paper relates some lessons that may be appropriate for...

  6. Educating and training north american travel agents and tour operators with webinars: the case of Switzerland Tourism North America

    OpenAIRE

    Kurt, Victoria; Salamin, Anne-Dominique

    2015-01-01

    Switzerland Tourism provides reliable, informative, high quality and long-term contacts to key accounts such as Travel Agents and Tour Operators in North America with the aim of boosting Switzerland’s presence in the market. The Trade Department is using various online tools such as e-learning platforms, a social media group and Webinars to educate and train the travel professionals. Since 2003, participants to Webinars have increased smoothly; therefore the Company would like to know if this...

  7. Shifting Pacific storm tracks as stressors to ecosystems of western North America.

    Science.gov (United States)

    Dannenberg, Matthew P; Wise, Erika K

    2017-11-01

    Much of the precipitation delivered to western North America arrives during the cool season via midlatitude Pacific storm tracks, which may experience future shifts in response to climate change. Here, we assess the sensitivity of the hydroclimate and ecosystems of western North America to the latitudinal position of cool-season Pacific storm tracks. We calculated correlations between storm track variability and three hydroclimatic variables: gridded cool-season standardized precipitation-evapotranspiration index, April snow water equivalent, and water year streamflow from a network of USGS stream gauges. To assess how historical storm track variability affected ecosystem processes, we derived forest growth estimates from a large network of tree-ring widths and land surface phenology and wildfire estimates from remote sensing. From 1980 to 2014, cool-season storm tracks entered western North America between approximately 41°N and 53°N. Cool-season moisture supply and snowpack responded strongly to storm track position, with positive correlations to storm track latitude in eastern Alaska and northwestern Canada but negative correlations in the northwestern U.S. Ecosystems of the western United States were greener and more productive following winters with south-shifted storm tracks, while Canadian ecosystems were greener in years when the cool-season storm track was shifted to the north. On average, larger areas of the northwestern United States were burned by moderate to high severity wildfires when storm tracks were displaced north, and the average burn area per fire also tended to be higher in years with north-shifted storm tracks. These results suggest that projected shifts of Pacific storm tracks over the 21st century would likely alter hydroclimatic and ecological regimes in western North America, particularly in the northwestern United States, where moisture supply and ecosystem processes are highly sensitive to the position of cool-season storm tracks.

  8. Integrated Bird Conservation along the Pacific Coast of North America: An Action Agenda

    Science.gov (United States)

    Gregg Elliott; Bob Altman; Wendy Easton; Ricardo Estrella; Geoffrey Geupel; Mary Chase; Ellie Cohen; Ann Chrisney

    2005-01-01

    Scientists and managers representing the continental bird conservation plans explored the status of conservation planning and implementation for birds along the Pacific coast of North America. The theme of the session, "using common currencies to advance bird conservation," emphasized the components of bird conservation shared among the major initiatives,...

  9. 78 FR 39772 - Electrolux Home Care Products, Inc., a Subsidiary of Electrolux North America, Inc., Electrolux...

    Science.gov (United States)

    2013-07-02

    ...,702B] Electrolux Home Care Products, Inc., a Subsidiary of Electrolux North America, Inc., Electrolux... On-Site at Electrolux Home Care Products, Inc., Webster City, Iowa; Electrolux Home Care Products... Leased Workers From Per Mar Security, 400 Des Moines Street, Webster City, Iowa; Amended Certification...

  10. Adult Literacy and Basic Education in Europe and North America: From Recognition to Provision.

    Science.gov (United States)

    Limage, Leslie

    1990-01-01

    Examines the growth of recognition of adult illiteracy in Western Europe and North America since the early 1970s. Discusses the invisibility of the problem, types of illiteracy identified in schools, importance of literacy across the curriculum, links between illiteracy and poverty, and involvement of international organizations. Contains 36…

  11. The Current State of European Studies in North America and of Scholarly Publishing in Western Europe.

    Science.gov (United States)

    Hacken, Richard

    1998-01-01

    Relates how scholarly publishing in Western Europe feeds into North America. Discusses globalization, regionalism, and particularism; new models and research methodology; Biblio-Darwinism (survival of the fittest publishing languages) and the language of the imprint; differing academic infrastructures of Europe; booming scholarly-title production;…

  12. Predicting the effect of fire on large-scale vegetation patterns in North America.

    Science.gov (United States)

    Donald McKenzie; David L. Peterson; Ernesto. Alvarado

    1996-01-01

    Changes in fire regimes are expected across North America in response to anticipated global climatic changes. Potential changes in large-scale vegetation patterns are predicted as a result of altered fire frequencies. A new vegetation classification was developed by condensing Kuchler potential natural vegetation types into aggregated types that are relatively...

  13. Phenotypic variability in a panel of strawberry cultivars from North America and the European Union

    Science.gov (United States)

    The phenotypic diversity in 96 antique and modern cultivars from the European Union and North America was evaluated in Michigan and Oregon, in 2011 and 2012. A total of thirty-five fruit and developmental characteristics were measured. Significant differences (p < 0.05) were observed among cultivars...

  14. Ecology and silviculture of the spruce-fir forests of eastern North America

    Science.gov (United States)

    Marinus. Westveld

    1953-01-01

    Using the climax forest as a guide to growing the species best suited to the climate and the site, the author offers a silvicultural system for managing the spruce-fir forests of eastern North America. Based on ecological principles, such silviculture is aimed to bring about forests that are inherently healthy and have a natural resistance to insects and disease.

  15.  Climate change may trigger broad shifts in North America's Pacific Coastal rainforests

    Science.gov (United States)

    Dominick A. DellaSala; Patric Brandt; Marni   Koopman; Jessica Leonard; Claude Meisch; Patrick Herzog; Paul Alaback; Michael I. Goldstein; Sarah Jovan; Andy MacKinnon; Henrik von Wehrden

    2015-01-01

    Climate change poses significant threats to Pacific coastal rainforests of North America. Land managers currently lack a coordinated climate change adaptation approach with which to prepare the region's globally outstanding biodiversity for accelerating change. We provided analyses intended to inform coordinated adaptation for eight focal rainforest tree species...

  16. Data-driven diagnostics of terrestrial carbon dynamics over North America

    Science.gov (United States)

    Jingfeng Xiao; Scott V. Ollinger; Steve Frolking; George C. Hurtt; David Y. Hollinger; Kenneth J. Davis; Yude Pan; Xiaoyang Zhang; Feng Deng; Jiquan Chen; Dennis D. Baldocchi; Bevery E. Law; M. Altaf Arain; Ankur R. Desai; Andrew D. Richardson; Ge Sun; Brian Amiro; Hank Margolis; Lianhong Gu; Russell L. Scott; Peter D. Blanken; Andrew E. Suyker

    2014-01-01

    The exchange of carbon dioxide is a key measure of ecosystem metabolism and a critical intersection between the terrestrial biosphere and the Earth's climate. Despite the general agreement that the terrestrial ecosystems in North America provide a sizeable carbon sink, the size and distribution of the sink remain uncertain. We use a data-driven approach to upscale...

  17. Effects of livestock grazing on neotropical migratory landbirds in western North America

    Science.gov (United States)

    Carl E. Bock; Victoria A. Saab; Terrell D. Rich; David S. Dobkin

    1993-01-01

    Livestock grazing is a widespread and important influence on neotropical migratory birds in four major ecosystems in western North America: grasslands of the Great Plains and Southwest, riparian woodlands, Intermountain shrubsteppe, and open coniferous forests. We have reviewed available literature on avian responses to grazing in these habitats. Among 35 plains...

  18. New species of Braggia (Hemiptera: Aphididae) on buckwheat in western North America

    Science.gov (United States)

    K. S. Pike; G. Graf; R. G. Foottit; H. E. L. Maw; P. Stary; R. Hammon; D. G. Miller

    2009-01-01

    Species of Braggia Gillette and Palmer (Hemiptera: Aphididae: Aphidinae: Aphidini) feed on various buckwheat, Eriogonum Michx. (Polygonaceae), species in western North America. Two new species, Braggia columbiana Pike n. sp. from Washington and Oregon and Braggia longicauda Pike n. sp. from Washington, Oregon, and northern California, are proposed. Descriptions,...

  19. First report of Pineus strobi (Hartig, 1839) (Hemiptera: Adelgidae) in western North America

    Science.gov (United States)

    Molly Darr; Scott Salom; Rachel K. Brooks; Robert G. Foottit; Gary L. Miller; Nathan P. Havill

    2018-01-01

    The pine bark adelgid, Pineus strobi (Hartig, 1839) (Hempitera: Adelgidae), is native to eastern North America and is found throughout the natural range of its main host species, eastern white pine, Pinus strobus L. (Pinaceae), which stretches from the Atlantic coast, west to Ontario and Minnesota (Drooz 1985). For the first...

  20. First report of Pineus strobi (Hartig) (Hemiptera: Adelgidae) in western North America

    Science.gov (United States)

    The pine bark adelgid, Pineus strobi (Hartig, 1839) (Hempitera: Adelgidae), is native to eastern North America. Its main host species is eastern white pine, Pinus strobus L. Pineus strobi is reported here for the first time from Washington, Colorado, Saskatchewan and tentatively Oregon by identifica...

  1. 78 FR 51271 - Michelin North America, Inc., Moot of Petition for Decision of Inconsequential Noncompliance

    Science.gov (United States)

    2013-08-20

    .... The subject tires meet or exceed all applicable FMVSS performance standards. 2. Associated with the... tire has the performance capacity of an Extra Load tire, the load requirement of the standard load.... SUMMARY: Michelin North America, Inc. (Michelin),\\1\\ has determined that certain BF Goodrich brand tires...

  2. Pedicularis and Castilleja are natural hosts of Cronartium ribicola in North America: A first report

    Science.gov (United States)

    Geral I. McDonald; Bryce A. Richardson; Paul J. Zambino; Ned B. Klopfenstein; Mee-Sook Kim

    2006-01-01

    White pine blister rust disease, caused by the introduced pathogen Cronartium ribicola, has severely disrupted five-needled pine ecosystems in North America. A 100-year effort to manage this disease was predicated in part on the premise that the pathogen utilizes only species of Ribes (Grossulariaceae) as...

  3. First record of Acizzia jamatonica (Hemiptera: Psyllidae) in North America: friend or foe?

    Science.gov (United States)

    Michael D. Ulyshen; Douglass Miller

    2007-01-01

    Acizzia jamatonica (Kuwayama) (Hemiptera: Sternorrhyncha: Psyllidae) is reported for the first time in North America. Because the species is thought to feed exclusively on Albizia, it may prove to be an effective biocontrol agent against the invasive Albizia julibrissin Durazzini in the southeastern United States. Because A. julibrissin is also an ornamental plant of...

  4. Ecology and management of morels harvested from the forests of western North America.

    Science.gov (United States)

    David Pilz; Rebecca McLain; Susan Alexander; Luis Villarreal-Ruiz; Shannon Berch; Tricia L. Wurtz; Catherine G. Parks; Erika McFarlane; Blaze Baker; Randy Molina; Jane E. Smith

    2007-01-01

    Morels are prized edible mushrooms that fruit, sometimes prolifically, in many forest types throughout western North America. They are collected for personal consumption and commercially harvested as valuable special (nontimber) forest products. Large gaps remain, however, in our knowledge about their taxonomy, biology, ecology, cultivation, safety, and how to manage...

  5. Migration of Computer Science Graduates from South Asia to Europe and North America

    Science.gov (United States)

    Khan, W. A.; Siddiqi, A. B.; Ahmed, F.

    2006-01-01

    This paper addresses the influx of computer science graduates from South Asia into Europe and North America. It analyses the need and supply chains between two points and identifies the pros and cons of the education imparted to these graduates. The effects of social disorder due to migrations are addressed. The resulting technological vacuum in…

  6. The role of herbicides for enhancing productivity and conserving land for biodiversity in North America

    Science.gov (United States)

    Robert G. Wagner; Michael Newton; Elizabeth C. Cole; James H. Miller; Barry D. Shiver

    2004-01-01

    Herbicide technology has evolved with forest management in North America over the past 60 years and has become an integral part of modern forestry practice. Forest managers have prescribed herbicides to increase reforestation success and long-term timber yields. Wildlife managers and others interested in conserving biodi- versity, however, have often viewed herbicide...

  7. Resistance to invasion and resilience to fire in desert shrublands of North America

    Science.gov (United States)

    Matthew L. Brooks; Jeanne C. Chambers

    2011-01-01

    Settlement by Anglo-Americans in the desert shrublands of North America resulted in the introduction and subsequent invasion of multiple nonnative grass species. These invasions have altered presettlement fire regimes, resulted in conversion of native perennial shrublands to nonnative annual grasslands, and placed many native desert species at risk. Effective...

  8. Effects of Nitrogen Deposition on Greenhouse-Gas Fluxes for Forests and Grasslands of North America

    Science.gov (United States)

    Human activities have substantially elevated the atmospheric deposition of reactive nitrogen (N) onto terrestrial ecosystems of North America. Some of this N can stimulate carbon (C) storage in terrestrial ecosystems, but the fertilization effect of added N can be diminished by e...

  9. The emerald ash borer: a new exotic pest in North America

    Science.gov (United States)

    Robert A. Haack; Eduard Jendak; Liu Houping; Keneth R. Marchant; Toby R. Petrice; Therese M. Poland; Hui Ye

    2002-01-01

    Yet another new exotic forest pest has been discovered in North America, and this time the infestation is centered in Michigan and Ontario. In May and June 2002, adults of an unidentified buprestid beetle were collected from ash (Fraxinus) trees in the Detroit area of southeastern Michigan.

  10. Phylogeny of Cirsium spp. in North America: host specificity does not follow phylogeny

    Science.gov (United States)

    Weedy invasive Cirsium spp. are widespread in temperate regions of North America and some of their biological control agents have attacked native Cirsium spp. A phylogenetic tree was developed from DNA sequences for the internal transcribed spacer and external transcribed spacer regions from native ...

  11. A simple tool for estimating throughfall nitrogen deposition in forests of western North America using lichens

    Science.gov (United States)

    Heather T. Root; Linda H. Geiser; Mark E. Fenn; Sarah Jovan; Martin A. Hutten; Suraj Ahuja; Karen Dillman; David Schirokauer; Shanti Berryman; Jill A. McMurray

    2013-01-01

    Anthropogenic nitrogen (N) deposition has had substantial impacts on forests of North America. Managers seek to monitor deposition to identify areas of concern and establish critical loads, which define the amount of deposition that can be tolerated by ecosystems without causing substantial harm. We present a new monitoring approach that estimates throughfall inorganic...

  12. Threats to riparian ecosystems in western North America: An analysis of existing literature

    Science.gov (United States)

    Boris Poff; Karen A. Koestner; Dan Neary; Victoria Henderson

    2011-01-01

    A total of 453 journal articles, reports, books, and book chapters addressing threats to riparian ecosystems in western North America were analyzed to identify, quantify, and qualify the major threats to these ecosystems as represented in the existing literature. Publications were identified either as research, policy, literature review, historical comparison, or...

  13. Global monthly CO2 flux inversion with a focus over North America

    International Nuclear Information System (INIS)

    Feng Deng; Chen, Jing M.; Ishizawa, Misa; Chiu-Wai Yuen; Gang Mo; Higuchi, Kaz; Chan, Douglas; Maksyutov, Shamil

    2007-01-01

    A nested inverse modelling system was developed for estimating carbon fluxes of 30 regions in North America and 20 regions for the rest of the globe. Monthly inverse modelling was conducted using CO 2 concentration measurements of 3 yr (2001-2003) at 88 sites. Inversion results show that in 2003 the global carbon sink is -2.76 ± 0.55 Pg C. Oceans and lands are responsible for 88.5% and 11.5% of the sink, respectively. Northern lands are the largest sinks with North America contributing a sink of -0.97 ± 0.21 Pg C in 2003, of which Canada's sink is -0.34 ± 0.14 Pg C. For Canada, the inverse results show a spatial pattern in agreement, for the most part, with a carbon source and sink distribution map previously derived through ecosystem modelling. However, discrepancies in the spatial pattern and in flux magnitude between these two estimates exist in certain regions. Numerical experiments with a full covariance matrix, with the consideration of the error structure of the a priori flux field based on meteorological variables among the 30 North America regions, resulted in a small but meaningful improvement in the inverted fluxes. Uncertainty reduction analysis suggests that new observation sites are still needed to further improve the inversion for these 30 regions in North America

  14. Elaphomyces appalachiensis and E. verruculosus sp. nov. (Ascomycota Eurotiales, Elaphomycetaceae) from eastern North America

    Science.gov (United States)

    Michael A. Castellano; Gonzalo Guevara Guerrero; Jesus Garcia Jimenez; James M. Trappe

    2012-01-01

    We describe Elaphomyces verruculosus as new species from eastern North America, ranging from Quebec, Canada south along the eastern USA and along the Gulf Coast to northeastern México. E. verruculosus is similar in overall morphology to E. granulatus of Europe. In addition we re-describe E....

  15. The Luzula comosa complex (Luzula section Luzula, Juncaceae) in western North America

    Czech Academy of Sciences Publication Activity Database

    Zika, P. F.; Wilson, B. A.; Kirschner, Jan

    2015-01-01

    Roč. 192, č. 4 (2015), s. 201-229 ISSN 1179-3155 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : Luzula * Pacific North America * taxonomy Subject RIV: EF - Botanics Impact factor: 1.087, year: 2015

  16. Attraction of Halyomorpha halys (Hemiptera: Pentatomidae) haplotypes in North America and Europe to baited traps

    Science.gov (United States)

    Halyomorpha halys is a global invasive species native to Southeast Asia that is threatening agriculture in invaded regions. While pheromone-based monitoring tools for H. halys have been validated in North America and South Korea, their efficacy has not been widely evaluated in Europe. Our goals were...

  17. 78 FR 24304 - Petition for Exemption From the Vehicle Theft Prevention Standard; Maserati North America Inc.

    Science.gov (United States)

    2013-04-24

    ... From the Vehicle Theft Prevention Standard; Maserati North America Inc. AGENCY: National Highway... exemption of the Quattroporte vehicle line in accordance with 49 CFR Part 543, Exemption from the Theft... motor vehicle theft as compliance with the parts-marking requirements of the Theft Prevention Standard...

  18. Global warming and stress complexes in forests of western North America

    Science.gov (United States)

    Donald McKenzie; David L. Peterson; Jeremy J. Littell

    2009-01-01

    A warmer climate in western North America will likely affect forests directly through soil moisture stress and indirectly through increased extent and severity of disturbances. We propose that stress complexes, combinations of biotic and abiotic stresses, compromise the vigor and ultimate sustainability of forest ecosystems. Across...

  19. Cucullia umbratica (Lepidoptera, Noctuidae, a new European noctuid in North America

    Directory of Open Access Journals (Sweden)

    Louis Handfield

    2010-03-01

    Full Text Available The discovery of a noctuid new for North America, Cucullia umbratica (Linnaeus, 1758 (Lepidoptera: Noctuidae, is reported from the Magdalen Islands (Quebec, Canada. A male and a female from the Islands are illustrated as well as specimens of the superficially similar species Cucullia intermedia Speyer, 1870. The male genitalia of both species are illustrated.

  20. Standards and Guidelines of the Reading Recovery [TM] Council of North America. Third Edition: Fall 1998.

    Science.gov (United States)

    Reading Recovery Council of North America, Columbus, OH.

    This booklet outlines the Reading Recovery Council of North America's (RRCNA) standards and guidelines for those who are responsible for the establishment and maintenance of effective Reading Recovery and/or "Descubriendo La Lectura" sites. The standards are deemed essential for assuring quality services to children and effective…

  1. 77 FR 65150 - Cryovac North America; Withdrawal of Color Additive Petition

    Science.gov (United States)

    2012-10-25

    ... regulations be amended to provide for the safe use of synthetic iron oxide as a color additive in or on cooked... Exempt From Certification to provide for the safe use of synthetic iron oxide as a color additive in or.... FDA-2004-C-0559 (Formerly Docket No. 2004C[hyphen]0078)] Cryovac North America; Withdrawal of Color...

  2. Geography of spring landbird migration through riparian habitats in southwestern North America

    Science.gov (United States)

    Susan K. Skagen; Jeffrey F. Kelly; Charles van Riper III; Richard L. Hutto; Deborah M. Finch; David J. Krueper; Cynthia P. Melcher

    2005-01-01

    Migration stopover resources, particularly riparian habitats, are critically important to landbirds migrating across the arid southwestern region of North America. To explore the effects of species biogeography and habitat affinity on spring migration patterns, we synthesized existing bird abundance and capture data collected in riparian habitats of the borderlands...

  3. Temporal dynamics of woodpecker predation on the invasive emerald ash borer (Agrilus planipennis) in North America

    Science.gov (United States)

    Woodpeckers (Picidae) are among the most prevalent natural enemies attacking the invasive emerald ash borer (EAB), Agrilus planipennis Fairmaire, in North America, but there can be considerable variation in the levels of EAB predation on ash trees (Oleaceae: Fraxinus) within and between sites as wel...

  4. Thermal constraints on the emerald ash borer invasion of North America

    Science.gov (United States)

    DeSantis, R.; Moser, W. K.; Gormanson, D. D.; Bartlett, M. G.

    2012-12-01

    Emerald ash borer (Agrilus planipennis Fairmaire; EAB), a non-native invasive beetle, has caused substantial damage to green (Fraxinus pennsylvanica Marsh.), white (Fraxinus americana L.), and black ash (Fraxinus nigra Marsh.), the major ash species of North America. In the absence of effective methods for controlling or eradicating the beetle, EAB continues to spread unimpeded across North America. Evidence indicates the mortality rate for EAB-infested trees near the epicenter of the infestation in southeast Michigan exceeds 99 percent for the major ash species. One possible climatic limitation on the spread of the infestation is suggested by recent work indicating that beetles cannot survive exposure to temperatures below -35.3 degrees Celsius. We considered whether this thermal constraint will limit the spread and distribution of EAB in North America. Historical climatic data for the United States and Canada were employed along with thermal models of the conditions beneath likely winter snowpack and beneath tree bark to predict the potential geographic distribution of the invasion. Results suggested the thermal mortality constraint will not lead to the protection of ash stands across most of North America. However, recent work indicates the majority of beetles cannot survive exposure to temperatures below -30 degrees Celsius. Along with our results, this suggests thermal constraints near the northern and western edges of the ranges of ash might limit EAB survival to some extent, thereby reducing the EAB population, the likelihood of EAB infestation, and subsequent ash mortality.

  5. Stephanospora michoacanensis (Stephanosporaceae, Agaricales), a novel sequestrate truffle from North America

    Science.gov (United States)

    Gonzalo Guevara-Guerrero; Ivone Baez-Alvarado; Victor M. Gomez-Reyes; Michael Castellano

    2015-01-01

    Stephanospora michoacanensis is presented as a new species from North America. This angiocarpic species is recognized by its yellowcream peridial surface color, and broadly ellipsoid to subglobose, spiny or crested, inamyloid spores with a distinct, complete or nearly complete corona at its base. Stephanospora michoacanensis is similar to S. caroticolor, but S....

  6. Newspaper Coverage of Zebra Mussels in North America : A Case of "Afghanistanism"?

    OpenAIRE

    Roush, Donny; Fortner, Rosanne

    1996-01-01

    Few environmental issues have arisen so abruptly, spread so rapidly, and been so clearly linked to human activity as has the introduction of nonindigenous zebra mussels to the surface freshwater of North America. This research examines communication patterns in information about zebra mussels as an example of how the mass media deal with threats to the environment.

  7. Phytophthora ramorum detections in Canada: Evidence for migration within North America and from Europe

    Science.gov (United States)

    E.M. Goss; M. Larsen; A. Vercauteren; S. Werres; K. Heungens; N.J. Grünwald

    2011-01-01

    Phytophthora ramorum, the cause of sudden oak death on oak and ramorum blight on woody ornamentals, has been reported in ornamental nurseries on the West Coast of North America from British Columbia to California. Long-distance migration of P. ramorum has occurred via the nursery trade, and shipments of host plants are known to...

  8. Emerald ash borer in North America: a research and regulatory challenge

    Science.gov (United States)

    David Cappaert; Deborah G. McCullough; Therese M. Poland; Nathan W. Siegert

    2005-01-01

    The saga of the emerald ash borer, Agrilus planipennis Fairmare (Coleoptera: Buprestidae), in North America began on 25 June 2002, when five entomologists representing Michigan State University (MSU), the Michigan Department of Natural Resources (MDNR), and the U.S. Department of Agriculture, Animal and Plant Health Inspection Service (USDA APHIS)...

  9. Quinoa cultivation in western North America: lessons learned and the path forward

    Science.gov (United States)

    Quinoa (Chenopodium quinoa Willd) is a relatively new crop to farmers in North America; however recent interest in domestic cultivation of quinoa has skyrocketed due to a rapid, worldwide increase in demand for this nutritious and delicious Andean crop. Researchers at five western U.S. universities ...

  10. 75 FR 17828 - Michelin North America, Inc., Grant of Petition for Decision of Inconsequential Noncompliance

    Science.gov (United States)

    2010-04-07

    ... retread, repair, and recycling industries must also be considered. Although tire construction affects the... tire retread, repair, and recycling industries. The use of steel cord construction in the sidewall and... Noncompliance Michelin North America, Inc. (Michelin), has determined that certain passenger car tires...

  11. Geologic literature on North America, 1785-1918; Part I, Bibliography

    Science.gov (United States)

    Nickles, John M.

    1923-01-01

    The bibliography forming Part I of this compilation includes papers relating to the geology paleontology, petrology, and mineralogy of North America-specifically, the United States, the Dominion of Canada and Newfoundland, the Arctic regions north of the continent, Greenland, Mexico Central America, Panama, and the West Indies including Trinidad-and also the Hawaiian Islands. Geographic and descriptive writings and accounts of travels with incidental mention of geologic facts are not included. Textbooks published in America and work general in character by American authors are given but general papers by foreign writers are excluded unless they have appeared in American publications. Papers by American writers on the geology of other parts of the world are not listed.

  12. Discovery of the oldest record of Nitellopsis obtusa (Charophyceae, Charophyta) in North America.

    Science.gov (United States)

    Karol, Kenneth G; Sleith, Robin S

    2017-10-01

    Studies of the colonization and spread of invasive species improves our understanding of key concepts in population biology as well as informs control and prevention efforts. The characean green alga Nitellopsis obtusa (starry stonewort) is rare in its native Eurasian range but listed by the United States Geological Survey (USGS) as an aggressive invasive in North America. First documented in North America in 1978 from New York, United States, it has since been reported from numerous inland lakes from Minnesota to Vermont, and from Lake Ontario and inland lakes in southern Ontario, Canada. While the ecological impacts of N. obtusa are not clearly understood in its invasive range, initial results show negative environmental effects. We have discovered a liquid-preserved herbarium specimen that predates the 1978 records by at least 4 years, and is the first confirmed record of N. obtusa in Québec. © 2017 Phycological Society of America.

  13. First Detection of Bat White-Nose Syndrome in Western North America.

    Science.gov (United States)

    Lorch, Jeffrey M; Palmer, Jonathan M; Lindner, Daniel L; Ballmann, Anne E; George, Kyle G; Griffin, Kathryn; Knowles, Susan; Huckabee, John R; Haman, Katherine H; Anderson, Christopher D; Becker, Penny A; Buchanan, Joseph B; Foster, Jeffrey T; Blehert, David S

    2016-01-01

    White-nose syndrome (WNS) is an emerging fungal disease of bats caused by Pseudogymnoascus destructans. Since it was first detected near Albany, NY, in 2006, the fungus has spread across eastern North America, killing unprecedented numbers of hibernating bats. The devastating impacts of WNS on Nearctic bat species are attributed to the likely introduction of P. destructans from Eurasia to naive host populations in eastern North America. Since 2006, the disease has spread in a gradual wavelike pattern consistent with introduction of the pathogen at a single location. Here, we describe the first detection of P. destructans in western North America in a little brown bat (Myotis lucifugus) from near Seattle, WA, far from the previously recognized geographic distribution of the fungus. Whole-genome sequencing and phylogenetic analyses indicated that the isolate of P. destructans from Washington grouped with other isolates of a presumed clonal lineage from the eastern United States. Thus, the occurrence of P. destructans in Washington does not likely represent a novel introduction of the fungus from Eurasia, and the lack of intensive surveillance in the western United States makes it difficult to interpret whether the occurrence of P. destructans in the Pacific Northwest is disjunct from that in eastern North America. Although there is uncertainty surrounding the impacts of WNS in the Pacific Northwest, the presence of the pathogen in western North America could have major consequences for bat conservation. IMPORTANCE White-nose syndrome (WNS) represents one of the most consequential wildlife diseases of modern times. Since it was first documented in New York in 2006, the disease has killed millions of bats and threatens several formerly abundant species with extirpation or extinction. The spread of WNS in eastern North America has been relatively gradual, inducing optimism that disease mitigation strategies could be established in time to conserve bats susceptible

  14. First detection of bat white-nose syndrome in western North America

    Science.gov (United States)

    Lorch, Jeffrey M.; Palmer, Jonathan M.; Lindner, Daniel L.; Ballmann, Anne; George, Kyle; Griffin, Kathryn M.; Knowles, Susan N.; Huckabee, John R.; Haman, Katherine H.; Anderson, Christopher D.; Becker, Penny A.; Buchanan, Joseph B.; Foster, Jeffrey T.; Blehert, David

    2016-01-01

    White-nose syndrome (WNS) is an emerging fungal disease of bats caused by Pseudogymnoascus destructans. Since it was first detected near Albany, NY, in 2006, the fungus has spread across eastern North America, killing unprecedented numbers of hibernating bats. The devastating impacts of WNS on Nearctic bat species are attributed to the likely introduction of P. destructans from Eurasia to naive host populations in eastern North America. Since 2006, the disease has spread in a gradual wavelike pattern consistent with introduction of the pathogen at a single location. Here, we describe the first detection of P. destructans in western North America in a little brown bat (Myotis lucifugus) from near Seattle, WA, far from the previously recognized geographic distribution of the fungus. Whole-genome sequencing and phylogenetic analyses indicated that the isolate of P. destructans from Washington grouped with other isolates of a presumed clonal lineage from the eastern United States. Thus, the occurrence of P. destructans in Washington does not likely represent a novel introduction of the fungus from Eurasia, and the lack of intensive surveillance in the western United States makes it difficult to interpret whether the occurrence of P. destructans in the Pacific Northwest is disjunct from that in eastern North America. Although there is uncertainty surrounding the impacts of WNS in the Pacific Northwest, the presence of the pathogen in western North America could have major consequences for bat conservation.

  15. The conquering of North America: dated phylogenetic and biogeographic inference of migratory behavior in bee hummingbirds.

    Science.gov (United States)

    Licona-Vera, Yuyini; Ornelas, Juan Francisco

    2017-06-05

    Geographical and temporal patterns of diversification in bee hummingbirds (Mellisugini) were assessed with respect to the evolution of migration, critical for colonization of North America. We generated a dated multilocus phylogeny of the Mellisugini based on a dense sampling using Bayesian inference, maximum-likelihood and maximum parsimony methods, and reconstructed the ancestral states of distributional areas in a Bayesian framework and migratory behavior using maximum parsimony, maximum-likelihood and re-rooting methods. All phylogenetic analyses confirmed monophyly of the Mellisugini and the inclusion of Atthis, Calothorax, Doricha, Eulidia, Mellisuga, Microstilbon, Myrmia, Tilmatura, and Thaumastura. Mellisugini consists of two clades: (1) South American species (including Tilmatura dupontii), and (2) species distributed in North and Central America and the Caribbean islands. The second clade consists of four subclades: Mexican (Calothorax, Doricha) and Caribbean (Archilochus, Calliphlox, Mellisuga) sheartails, Calypte, and Selasphorus (incl. Atthis). Coalescent-based dating places the origin of the Mellisugini in the mid-to-late Miocene, with crown ages of most subclades in the early Pliocene, and subsequent species splits in the Pleistocene. Bee hummingbirds reached western North America by the end of the Miocene and the ancestral mellisuginid (bee hummingbirds) was reconstructed as sedentary, with four independent gains of migratory behavior during the evolution of the Mellisugini. Early colonization of North America and subsequent evolution of migration best explained biogeographic and diversification patterns within the Mellisugini. The repeated evolution of long-distance migration by different lineages was critical for the colonization of North America, contributing to the radiation of bee hummingbirds. Comparative phylogeography is needed to test whether the repeated evolution of migration resulted from northward expansion of southern sedentary

  16. Clustering of 770,000 genomes reveals post-colonial population structure of North America

    Science.gov (United States)

    Han, Eunjung; Carbonetto, Peter; Curtis, Ross E.; Wang, Yong; Granka, Julie M.; Byrnes, Jake; Noto, Keith; Kermany, Amir R.; Myres, Natalie M.; Barber, Mathew J.; Rand, Kristin A.; Song, Shiya; Roman, Theodore; Battat, Erin; Elyashiv, Eyal; Guturu, Harendra; Hong, Eurie L.; Chahine, Kenneth G.; Ball, Catherine A.

    2017-02-01

    Despite strides in characterizing human history from genetic polymorphism data, progress in identifying genetic signatures of recent demography has been limited. Here we identify very recent fine-scale population structure in North America from a network of over 500 million genetic (identity-by-descent, IBD) connections among 770,000 genotyped individuals of US origin. We detect densely connected clusters within the network and annotate these clusters using a database of over 20 million genealogical records. Recent population patterns captured by IBD clustering include immigrants such as Scandinavians and French Canadians; groups with continental admixture such as Puerto Ricans; settlers such as the Amish and Appalachians who experienced geographic or cultural isolation; and broad historical trends, including reduced north-south gene flow. Our results yield a detailed historical portrait of North America after European settlement and support substantial genetic heterogeneity in the United States beyond that uncovered by previous studies.

  17. Emerald ash borer invasion of North America: history, biology, ecology, impacts, and management.

    Science.gov (United States)

    Herms, Daniel A; McCullough, Deborah G

    2014-01-01

    Since its accidental introduction from Asia, emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), has killed millions of ash trees in North America. As it continues to spread, it could functionally extirpate ash with devastating economic and ecological impacts. Little was known about EAB when it was first discovered in North America in 2002, but substantial advances in understanding of EAB biology, ecology, and management have occurred since. Ash species indigenous to China are generally resistant to EAB and may eventually provide resistance genes for introgression into North American species. EAB is characterized by stratified dispersal resulting from natural and human-assisted spread, and substantial effort has been devoted to the development of survey methods. Early eradication efforts were abandoned largely because of the difficulty of detecting and delineating infestations. Current management is focused on biological control, insecticide protection of high-value trees, and integrated efforts to slow ash mortality.

  18. The role of emergency medicine physicians in trauma care in North America: evolution of a specialty

    Directory of Open Access Journals (Sweden)

    Grossman Michael D

    2009-08-01

    Full Text Available Abstract The role of Emergency Medicine Physicians (EMP in the care of trauma patients in North America has evolved since the advent of the specialty in the late 1980's. The evolution of this role in the context of the overall demands of the specialty and accreditation requirements of North American trauma centers will be discussed. Limited available data published in the literature examining the role of EMP's in trauma care will be reviewed with respect to its implications for an expanded role for EMPs in trauma care. Two training models currently in the early stages of development have been proposed to address needs for increased manpower in trauma and the critical care of trauma patients. The available information regarding these models will be reviewed along with the implications for improving the care of trauma patients in both Europe and North America.

  19. 1987 wet deposition temporal and spatial patterns in North America

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, J.C.; Olsen, A.R.

    1990-03-01

    The focus of this report is on North American wet deposition temporal patterns from 1979 to 1987 and spatial patterns for 1987. The report investigates the patterns of annual precipitation-weighted average concentration and annual deposition for nine ion species: hydrogen, sulfate, nitrate, ammonium, calcium, chloride, sodium, potassium, and magnesium. Data are from the Acid Deposition System (ADS) for the statistical reporting of North American deposition data which includes the National Atmospheric Deposition Program/National Trends Network (NADP/NTN), the MAP3S precipitation chemistry network, the Utility Acid Precipitation Study Program (UAPSP), the Canadian Precipitation Monitoring Network (CAPMoN), and the daily and 4-weekly Acidic Precipitation in Ontario Study (APIOS-D and APIOS-C). Mosaic maps, based on surface estimation using kriging, display concentration and deposition spatial patterns of pH, hydrogen, sulfate, nitrate, ammonium, and calcium ion species for 1987 annual, winter, and summer periods. The temporal pattern analyses use a subset of 39 sites over a 9-year (1979--1987) period and an expanded subset of 140 sites with greater spatial coverage over a 6-year (1982--1987) period. 68 refs., 15 figs., 15 tabs.

  20. Red fox predation on breeding ducks in midcontinent North America

    Science.gov (United States)

    Sargeant, Alan B.; Allen, Stephen H.; Eberhardt, Robert T.

    1984-01-01

    Red fox (Vulpes vulpes) predation on nesting ducks was assessed by examining 1,857 adult duck remains found at 1,432 fox rearing dens from 1968 to 1973. Dabbling ducks were much more vulnerable to foxes than diving ducks. Dabbling ducks (1,798) found at dens consisted of 27% blue-winged teals (Anas discors), 23% mallards (A. platyrhynchos), 20% northern pintails (A. acuta), 9% northern shovelers (Spatula clypeata), 8% gadwalls (A. strepera), 3% green-winged teals (A. crecca), 2% American wigeons (A. americana), and 10% unidentified. Relative abundance of individual species and nesting chronology were the most important factors affecting composition of ducks taken by foxes. Seventy-six percent of 1,376 adult dabbling ducks and 40% of 30 adult diving ducks for which sex was determined were hens. In western North Dakota and western South Dakota, 65% of mallard and northern pintail remains found at dens were hens compared with 76% in eastern North Dakota and eastern South Dakota (P fox predation rates on ducks. Predation rate indices ranged from 0.01 duck/den in Iowa to 1.80 ducks/den in eastern North Dakota. Average annual predation rate indices for dabbling ducks in a 3-county intensive study area in eastern North Dakota were closely correlated with May pond numbers (r = 0.874, P foxes than hens of late nesting species. Predation rate indices were expanded to estimate total numbers of ducks taken by fox families during the denning season. Estimated numbers of dabbling ducks taken annually by individual fox families in 2 physiographic regions comprising the intensive study area ranged from 16.1 to 65.9. Predation was highest during wet years and lowest during dry years and averaged lower, but was more variable, in the region where tillage was greatest and wetland water levels were least stable. Predation in the intensive study area averaged 2.97 adult dabbling ducks/ km2/year and represented an estimated average annual loss of 13.5% of hen and 4.5% of drake

  1. The Okhotsk Plate and the Eurasia-North America plate boundary zone.

    Science.gov (United States)

    Hindle, David; Mackey, Kevin

    2014-05-01

    The Eurasia-North America plate boundary zone transitions from spreading at rates of ~ 25mm/yr in the North Atlantic, to compression at rates of ~ 5mm/yr in the region of the Okhotsk plate. Because the pole of rotation between Eurasia and North America lies more or less on their mutual boundary, there is a linear change in rate along the boundary, and regions near the euler pole are subject to extremely low deformation rates. The Okhotsk - Eurasia - North America triple junction lies slightly south of the rotation pole, placing the Okhotsk plate entirely in a weakly contractional setting. Regions near the triple junction absorb 1mm/yr contraction. Further south, towards the shoreline of the Okhotsk sea, up to 5 mm/yr contraction may be absorbed within the plate. How shortening is accommodated across the boundary remains an open question. One possibility is wholesale extrusion of the entire Okhotsk plate (or possibly its northwestern corner) along two plate boundary strike slip faults (Eurasia-Okhostk and North America Okhotsk). The problem with this model is that the seismic record does not presently clearly support it, with the largest events distributed both within the plate interior and on its boundaries. This may suggest that instead, the Okhotsk plate, and particularly its north-western end, consists of a series of smaller blocks which shuffle against each other, partially accommodating extrusion, but also permitting some internal deformation and change of shape of the Okhotsk plate itself. We present analyses of the very sparse seismic record from the region, as well as geometric-kinematic, tectonic models of the possible deformation of northwest Okhotsk to try to better understand the different probabilities of how this slowly deforming plate boundary zone is behaving.

  2. North America-Greenland-Eurasian relative motions: implications for circum-arctic tectonic reconstructions

    Energy Technology Data Exchange (ETDEWEB)

    Rowley, D.B.; Lottes, A.L.; Ziegler, A.M.

    1985-02-01

    The Mesozoic-Cenozoic tectonic evolution of the Circum-Arctic region is based on constraints imposed by (1) relative motion histories of the three major plates (North America, Greenland, and Eurasia) and a number of smaller pieces, and (2) distribution and age of sutures, accretionary prisms, volcanic arcs, fold-thrust belts, stretched continental crust, strike-slip faults, and ocean floor. The authors conclude that: (1) North America and Eurasia remained relatively fixed to each other until the latest Cretaceous-Paleocene opening of the Labrador Sea-Baffin Bay and Greenland-Norwegian and Eurasian basins (earlier convergence between North America and Eurasia in the Bering Sea region shown on many reconstructions are artifacts of incorrect plate reconstructions); (2) the North Slope-Seward-Chukotka block has constituted an isthmus connection between North America and northeast Asia since at least the middle Paleozoic and did not rotate away from the Canadian Arctic; (3) the Canada basin opened behind a clockwise-rotating Alpha Cordillera-Mendeleyev ridge arc during the Early to middle Cretaceous and consumed older, Paleozoic(.) Makarov basin ocean floor (the Chukchi cap is a detached continental fragment derived from the Beaufort Sea; the North Slope Arctic margin is a left-lateral transform fault associated with the opening of the Canada basin); and (4) the Nares Strait fault has a net relative displacement of approximately 25 km, but actual motion between Greenland and northern Ellesmere was about 250 km of strongly transpressive motion that resulted in the Eurekan and Svalbardian orogenies.

  3. Methane (CH4) Flux for North America L4 Daily V1 (CMS_CH4_FLX_NAD) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — The CMS Methane (CH4) Flux for North America data set contains estimates of methane emission in North America based on an inversion of the GEOS-Chem chemical...

  4. Tomotectonic constraints on deformation of Cordilleran North America since Late Jurassic

    Science.gov (United States)

    Mihalynuk, M. G.; Sigloch, K.

    2017-12-01

    Seismic tomography reveals detailed mantle structure beneath North America, largely thanks to USArray. TWO massive composite slabs are recognized down to 2000 km depth and their topologies are combined with quantitative plate reconstructions back to the breakup of Pangea using Atlantic and Pacific magnetic isochrons. This tomotectonic analysis reveals evolving arc/trench-plate geometries of a vast archipelago/microcontinent and ocean plateau that were overridden by North America, and an explanation for Cordilleran deformation episodes. As Pangea fragmented, subduction reconfigured from EAST-directed beneath the continent (during final growth of the Intermontane Superterrane, IMS, or "AltaBC"), to WEST-directed beneath an intraoceanic, massive arc chevron (MAC). MAC trenches were stationary within a mantle reference frame, as indicated by near-vertical slab walls 4-7x as thick as mature ocean lithosphere, and its trenches were >10,000 km long. East-pointing MAC apex was located 2000-4000 km off Pangea's west coast where MAC arc was built atop the Insular superterrane (INS, or "BajaBC"), a microcontinent extending >2600 km southwards from the apex. Ocean lithosphere between the MAC apex and west-drifting North America was consumed by 155 Ma. INS, comparable in length to the Indian subcontinent, initially collided with the leading edge of North America/IMS and generated "Nevadan" deformation. Diachronous Sevier deformation followed as MAC was driven farther into the continental margin and raked southward (sinistral offsets w.r.t. North America). By 130 Ma, with large segments accreted and MAC geometry breaking down, subduction was forced to jump outboard (westward) of MAC. The Franciscan accretionary complex marks a return to eastward/Andean-style subduction (of the Farallon plate). A remarkably complete analogue for collision at 130 Ma is found in modern Australia's override of arcs to its north. Rapid northward transport of BajaBC w.r.t. North America 90-50 Ma is

  5. Indigenous peoples of North America: environmental exposures and reproductive justice.

    Science.gov (United States)

    Hoover, Elizabeth; Cook, Katsi; Plain, Ron; Sanchez, Kathy; Waghiyi, Vi; Miller, Pamela; Dufault, Renee; Sislin, Caitlin; Carpenter, David O

    2012-12-01

    Indigenous American communities face disproportionate health burdens and environmental health risks compared with the average North American population. These health impacts are issues of both environmental and reproductive justice. In this commentary, we review five indigenous communities in various stages of environmental health research and discuss the intersection of environmental health and reproductive justice issues in these communities as well as the limitations of legal recourse. The health disparities impacting life expectancy and reproductive capabilities in indigenous communities are due to a combination of social, economic, and environmental factors. The system of federal environmental and Indian law is insufficient to protect indigenous communities from environmental contamination. Many communities are interested in developing appropriate research partnerships in order to discern the full impact of environmental contamination and prevent further damage. Continued research involving collaborative partnerships among scientific researchers, community members, and health care providers is needed to determine the impacts of this contamination and to develop approaches for remediation and policy interventions.

  6. Dietary change and evolution of horses in North America.

    Science.gov (United States)

    Mihlbachler, Matthew C; Rivals, Florent; Solounias, Nikos; Semprebon, Gina M

    2011-03-04

    The evolution of high-crowned molars among horses (Family Equidae) is thought to be an adaptation for abrasive diets associated with the spread of grasslands. The sharpness and relief of the worn cusp apices of teeth (mesowear) are a measure of dietary abrasion. We collected mesowear data for North American Equidae for the past 55.5 million years to test the association of molar height and dietary abrasion. Mesowear trends in horses are reflective of global cooling and associated vegetation changes. There is a strong correlation between mesowear and crown height in horses; however, most horse paleopopulations had highly variable amounts of dietary abrasion, suggesting that selective pressures for crown height may have been weak much of the time. However, instances of higher abrasion were observed in some paleopopulations, suggesting intervals of stronger selection for the evolution of dentitions, including the early Miocene shortly before the first appearance of Equinae, the horse subfamily in which high-crowned dentitions evolved.

  7. Cottonwood Tree Rings and Climate in Western North America

    Science.gov (United States)

    Friedman, J. M.; Edmondson, J.; Griffin, E. R.; Meko, D. M.; Merigliano, M. F.; Scott, J. A.; Scott, M. L.; Touchan, R.

    2012-12-01

    In dry landscapes of interior western USA, cottonwood (Populus spp.) seedling establishment often occurs only close to river channels after floods. Where winter is sufficiently cold, cottonwoods also have distinct annual rings and can live up to 370 years, allowing us to reconstruct the long-term history of river flows and channel locations. We have analyzed the annual rate of cottonwood establishment along streams in Montana, Wyoming, Colorado, North Dakota and Idaho. Because the trees germinate next to the river, establishment rates are strongly correlated with the rate of channel migration driven by floods. Along large rivers dominated by snowmelt from the mountains, interannual variation in peak flows and cottonwood establishment is small, and century-scale variation driven by climate change is apparent. The upper Snake, Yellowstone and Green rivers all show a strong decrease in cottonwood establishment beginning in the late 1800s and continuing to the present, indicating a decrease in peak flows prior to flow regulation by large dams. This is consistent with published tree-ring studies of montane conifers showing decreases in snowpack at the same time scale. In contrast, beginning in the late 1800s cottonwood ring widths along the Little Missouri River, North Dakota show an increase in annual growth that continues into the present. Because annual growth is strongly correlated with April-July flows (r=0.69) the ring-width data suggest an increase in April-July flows at the same time tree establishment dates suggest a decrease in peak flows. These results may be reconciled by the hypothesis that increases in low temperatures have decreased snowpack while lengthening the growing season.

  8. Patterns of admixture and population structure in native populations of Northwest North America.

    Directory of Open Access Journals (Sweden)

    Paul Verdu

    2014-08-01

    Full Text Available The initial contact of European populations with indigenous populations of the Americas produced diverse admixture processes across North, Central, and South America. Recent studies have examined the genetic structure of indigenous populations of Latin America and the Caribbean and their admixed descendants, reporting on the genomic impact of the history of admixture with colonizing populations of European and African ancestry. However, relatively little genomic research has been conducted on admixture in indigenous North American populations. In this study, we analyze genomic data at 475,109 single-nucleotide polymorphisms sampled in indigenous peoples of the Pacific Northwest in British Columbia and Southeast Alaska, populations with a well-documented history of contact with European and Asian traders, fishermen, and contract laborers. We find that the indigenous populations of the Pacific Northwest have higher gene diversity than Latin American indigenous populations. Among the Pacific Northwest populations, interior groups provide more evidence for East Asian admixture, whereas coastal groups have higher levels of European admixture. In contrast with many Latin American indigenous populations, the variance of admixture is high in each of the Pacific Northwest indigenous populations, as expected for recent and ongoing admixture processes. The results reveal some similarities but notable differences between admixture patterns in the Pacific Northwest and those in Latin America, contributing to a more detailed understanding of the genomic consequences of European colonization events throughout the Americas.

  9. Impact of the Winter North Pacific Oscillation on the Surface Air Temperature over Eurasia and North America: Sensitivity to the Index Definition

    Science.gov (United States)

    Chen, Shangfeng; Song, Linye

    2018-06-01

    This study analyzes the impact of the winter North Pacific Oscillation (NPO) on the surface air temperature (SAT) variations over Eurasia and North America based on six different NPO indices. Results show that the influences of the winter NPO on the SAT over Eurasia and North America are sensitive to the definition of the NPO index. The impact of the winter NPO on the SAT variations over Eurasia (North America) is significant (insignificant) when the anticyclonic anomaly associated with the NPO index over the North Pacific midlatitudes shifts westward and pronounced northerly wind anomalies appear around Lake Baikal. By contrast, the impact of the winter NPO on the SAT variations over Eurasia (North America) is insignificant (significant) when the anticyclonic anomaly over the North Pacific related to the NPO index shifts eastward and the associated northerly wind anomalies to its eastern flank extend to North America. The present study suggests that the NPO definition should be taken into account when analyzing the impact of the winter NPO on Eurasian and North American SAT variations.

  10. Ungulate predation and ecological roles of wolves and coyotes in eastern North America.

    Science.gov (United States)

    Benson, John F; Loveless, Karen M; Rutledge, Linda Y; Patterson, Brent R

    2017-04-01

    Understanding the ecological roles of species that influence ecosystem processes is a central goal of ecology and conservation biology. Eastern coyotes (Canis latrans) have ascended to the role of apex predator across much of eastern North America since the extirpation of wolves (Canis spp.) and there has been considerable confusion regarding their ability to prey on ungulates and their ecological niche relative to wolves. Eastern wolves (C. lycaon) are thought to have been the historical top predator in eastern deciduous forests and have previously been characterized as deer specialists that are inefficient predators of moose because of their smaller size relative to gray wolves (C. lupus). We investigated intrinsic and extrinsic influences on per capita kill rates of white-tailed deer (Odocoileus virginianus) and moose (Alces alces) during winter by sympatric packs of eastern coyotes, eastern wolves, and admixed canids in Ontario, Canada to clarify the predatory ability and ecological roles of the different canid top predators of eastern North America. Eastern coyote ancestry within packs negatively influenced per capita total ungulate (deer and moose combined) and moose kill rates. Furthermore, canids in packs dominated by eastern coyote ancestry consumed significantly less ungulate biomass and more anthropogenic food than packs dominated by wolf ancestry. Similar to gray wolves in previous studies, eastern wolves preyed on deer where they were available. However, in areas were deer were scarce, eastern wolves killed moose at rates similar to those previously documented for gray wolves at comparable moose densities across North America. Eastern coyotes are effective deer predators, but their dietary flexibility and low kill rates on moose suggest they have not replaced the ecological role of wolves in eastern North America. © 2017 by the Ecological Society of America.

  11. Priorities for improving the scientific foundation of conservation policy in North America.

    Science.gov (United States)

    Noss, Reed F; Fleishman, Erica; Dellasala, Dominick A; Fitzgerald, John M; Gross, Mart R; Main, Martin B; Nagle, Fiona; O'Malley, Stacey L; Rosales, Jon

    2009-08-01

    The Society for Conservation Biology (SCB) can enhance conservation of biodiversity in North America by increasing its engagement in public policy. Toward this end, the North America Section of SCB is establishing partnerships with other professional organizations in order to speak more powerfully to decision makers and taking other actions--such as increasing interaction with chapters--geared to engage members more substantively in science-policy issues. Additionally, the section is developing a North American Biodiversity Blueprint, which spans the continental United States and Canada and is informed by natural and social science. This blueprint is intended to clarify the policy challenges for protecting continental biodiversity, to foster bilateral collaboration to resolve common problems, and to suggest rational alternative policies and practices that are more likely than current practices to sustain North America's natural heritage. Conservation scientists and practitioners can play a key role by drawing policy makers' attention to ultimate, as well as proximate, causes of biodiversity decline and to the ecological and economic consequences of not addressing these threats.

  12. Future prospects for radioactive nuclear beams in North America

    International Nuclear Information System (INIS)

    Nitschke, J.M.

    1993-05-01

    In 1989 this author proposed the construction of a dedicated, flexible, radioactive nuclear beams facility that would provide intense beams of nearly all elements for a program of scientific studies in nuclear structure, nuclear reaction dynamics, astrophysics, high-spin physics, nuclei far from stability, material- and surface science, and atomic- and hyperfine-interaction physics. The initial name proposed for the new facility was ''IsoSpin Factory'' to underscore the key feature of this new physics tool; it was later changed to ''IsoSpin Laboratory'' (ISL). The ISL is now supported by a broad base of nuclear scientists and has been identified in the US Long Range Plan on Nuclear Science as one of the new potential construction projects for the second part of this decade. Since 1989 a number of conferences and workshops has been held in which the scientific and technical case for RNB facilities has been made. The purpose of this paper is to focus on the North American plan for the ISL, which was initially summarized in a ''White Paper'' but has since evolved in its scientific and technical scop

  13. The industrial applications of shape memory alloys in North America

    International Nuclear Information System (INIS)

    Mc Schetky D, L.

    2000-01-01

    Literature in the recent past on shape memory effect alloys dwelt principally on the physical metallurgy, crystallography and kinetics of the shape memory phenomenon. By contrast, we now have books and conference proceedings devoted to the engineering aspects of SMAs, their technology and application. The dominant role SMAs now play in the field of medical and orthodontic devices is well documented and will be reviewed by others in this conference. In this paper we will discuss the commercial applications for shape memory alloy devices in the North American market; applications which are in many cases also produced in European countries and Japan. The early success of shape memory alloy couplings for joining tubing and pipe in the late 1960's was not followed by other large volume applications until the advent of shape memory eyeglass frames, brassiere underwires and cellular phone antennas. Many other applications have now evolved into mature markets and these will be reviewed. In addition to the many commercial applications cited, there are a number of other fields in which shape memory alloys are destined to play a major role; these include smart materials and adaptive structures, MEMS devices, infrastructure systems and electrical power generation and distribution. These applications are being developed with private and government funding and will also be briefly discussed. (orig.)

  14. 1988 Wet deposition temporal and spatial patterns in North America

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, J.C.; Olsen, A.R.; Bittner, E.A.

    1992-03-01

    The focus of this report is on North American wet deposition temporal patterns from 1979 to 1988 and spatial patterns for 1988. It is the third in a series of reports that investigate the patterns of annual precipitation-weighted average concentration and annual deposition for nine ion species: hydrogen, sulfate, nitrate, ammonium, calcium, chloride, sodium, potassium, and magnesium. Mosaic maps, based on surface estimation using kriging, display concentration and deposition spatial patterns of pH, hydrogen, sulfate, nitrate, ammonium, and calcium ion species for 1988 annual, winter, and summer periods. Temporal pattern analyses use a subset of 35 sites over a 10-year (1979--1988) period and an expanded subset of 137 sites, with greater spatial coverage, over a 7-year (1982--1988) period. The 10-year period represents the longest period with wet deposition monitoring data available that has a sufficient number of sites with data of known quality to allow a descriptive summary of annual temporal patterns. Sen's median trend estimate and Kendall's seasonal tau (KST) test are calculated for each ion species concentration and deposition at each site in both subsets.

  15. 1988 Wet deposition temporal and spatial patterns in North America

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, J.C.; Olsen, A.R.; Bittner, E.A.

    1992-03-01

    The focus of this report is on North American wet deposition temporal patterns from 1979 to 1988 and spatial patterns for 1988. It is the third in a series of reports that investigate the patterns of annual precipitation-weighted average concentration and annual deposition for nine ion species: hydrogen, sulfate, nitrate, ammonium, calcium, chloride, sodium, potassium, and magnesium. Mosaic maps, based on surface estimation using kriging, display concentration and deposition spatial patterns of pH, hydrogen, sulfate, nitrate, ammonium, and calcium ion species for 1988 annual, winter, and summer periods. Temporal pattern analyses use a subset of 35 sites over a 10-year (1979--1988) period and an expanded subset of 137 sites, with greater spatial coverage, over a 7-year (1982--1988) period. The 10-year period represents the longest period with wet deposition monitoring data available that has a sufficient number of sites with data of known quality to allow a descriptive summary of annual temporal patterns. Sen`s median trend estimate and Kendall`s seasonal tau (KST) test are calculated for each ion species concentration and deposition at each site in both subsets.

  16. The industrial applications of shape memory alloys in North America

    Energy Technology Data Exchange (ETDEWEB)

    Mc Schetky D, L. [Memry Corp., Brookfield, CT (United States)

    2000-07-01

    Literature in the recent past on shape memory effect alloys dwelt principally on the physical metallurgy, crystallography and kinetics of the shape memory phenomenon. By contrast, we now have books and conference proceedings devoted to the engineering aspects of SMAs, their technology and application. The dominant role SMAs now play in the field of medical and orthodontic devices is well documented and will be reviewed by others in this conference. In this paper we will discuss the commercial applications for shape memory alloy devices in the North American market; applications which are in many cases also produced in European countries and Japan. The early success of shape memory alloy couplings for joining tubing and pipe in the late 1960's was not followed by other large volume applications until the advent of shape memory eyeglass frames, brassiere underwires and cellular phone antennas. Many other applications have now evolved into mature markets and these will be reviewed. In addition to the many commercial applications cited, there are a number of other fields in which shape memory alloys are destined to play a major role; these include smart materials and adaptive structures, MEMS devices, infrastructure systems and electrical power generation and distribution. These applications are being developed with private and government funding and will also be briefly discussed. (orig.)

  17. Lessons learned from research and surveillance directed at highly pathogenic influenza A viruses in wild birds inhabiting North America

    Science.gov (United States)

    Ramey, Andy M.; DeLiberto, Thomas J.; Berhane, Yohannes; Swayne, David E.; Stallknecht, David E.

    2018-01-01

    Following detections of highly pathogenic (HP) influenza A viruses (IAVs) in wild birds inhabiting East Asia after the turn of the millennium, the intensity of sampling of wild birds for IAVs increased throughout much of North America. The objectives for many research and surveillance efforts were directed towards detecting Eurasian origin HP IAVs and understanding the potential of such viruses to be maintained and dispersed by wild birds. In this review, we highlight five important lessons learned from research and surveillance directed at HP IAVs in wild birds inhabiting North America: (1) Wild birds may disperse IAVs between North America and adjacent regions via migration, (2) HP IAVs can be introduced to wild birds in North America, (3) HP IAVs may cross the wild bird-poultry interface in North America, (4) The probability of encountering and detecting a specific virus may be low, and (5) Population immunity of wild birds may influence HP IAV outbreaks in North America. We review empirical support derived from research and surveillance efforts for each lesson learned and, furthermore, identify implications for future surveillance efforts, biosecurity, and population health. We conclude our review by identifying five additional areas in which we think future mechanistic research relative to IAVs in wild birds in North America are likely to lead to other important lessons learned in the years ahead.

  18. Lessons learned from research and surveillance directed at highly pathogenic influenza A viruses in wild birds inhabiting North America.

    Science.gov (United States)

    Ramey, Andrew M; DeLiberto, Thomas J; Berhane, Yohannes; Swayne, David E; Stallknecht, David E

    2018-05-01

    Following detections of highly pathogenic (HP) influenza A viruses (IAVs) in wild birds inhabiting East Asia after the turn of the millennium, the intensity of sampling of wild birds for IAVs increased throughout much of North America. The objectives for many research and surveillance efforts were directed towards detecting Eurasian origin HP IAVs and understanding the potential of such viruses to be maintained and dispersed by wild birds. In this review, we highlight five important lessons learned from research and surveillance directed at HP IAVs in wild birds inhabiting North America: (1) Wild birds may disperse IAVs between North America and adjacent regions via migration, (2) HP IAVs can be introduced to wild birds in North America, (3) HP IAVs may cross the wild bird-poultry interface in North America, (4) The probability of encountering and detecting a specific virus may be low, and (5) Population immunity of wild birds may influence HP IAV outbreaks in North America. We review empirical support derived from research and surveillance efforts for each lesson learned and, furthermore, identify implications for future surveillance efforts, biosecurity, and population health. We conclude our review by identifying five additional areas in which we think future mechanistic research relative to IAVs in wild birds in North America are likely to lead to other important lessons learned in the years ahead. Published by Elsevier Inc.

  19. A Tragedy of Democracy: Japanese Confinement in North America

    Directory of Open Access Journals (Sweden)

    Greg Robinson

    2010-03-01

    Full Text Available

    The confinement of some 120,000 Japanese Americans during World War II, often called the Japanese American internment, has been described as the worst official civil rights violation of modern U. S. history. Greg Robinson not only offers a bold new understanding of these events but also studies them within a larger time frame and from a transnational perspective. Drawing on newly discovered material, Robinson provides a backstory of confinement that reveals for the first time the extent of the American government's surveillance of Japanese communities in the years leading up to war and the construction of what officials termed "concentration camps" for enemy aliens. He also considers the aftermath of confinement, including the place of Japanese Americans in postwar civil rights struggles, the long movement by former camp inmates for redress, and the continuing role of the camps as touchstones for nationwide commemoration and debate. Most remarkably, A Tragedy of Democracy is the first book to analyze official policy toward West Coast Japanese Americans within a North American context. Robinson studies confinement on the mainland alongside events in wartime Hawaii, where fears of Japanese Americans justified Army dictatorship, suspension of the Constitution, and the imposition of military tribunals. He similarly reads the treatment of Japanese Americans against Canada's confinement of 22,000 citizens and residents of Japanese ancestry from British Columbia. A Tragedy of Democracy recounts the expulsion of almost 5,000 Japanese from Mexico's Pacific Coast and the poignant story of the Japanese Latin Americans who were kidnapped from their homes and interned in the United States. Approaching Japanese confinement as a continental and international phenomenon, Robinson offers a truly kaleidoscopic understanding of its genesis and outcomes.

  20. A Tragedy of Democracy: Japanese Confinement in North America

    Directory of Open Access Journals (Sweden)

    Greg Robinson

    2010-03-01

    Full Text Available The confinement of some 120,000 Japanese Americans during World War II, often called the Japanese American internment, has been described as the worst official civil rights violation of modern U. S. history. Greg Robinson not only offers a bold new understanding of these events but also studies them within a larger time frame and from a transnational perspective. Drawing on newly discovered material, Robinson provides a backstory of confinement that reveals for the first time the extent of the American government's surveillance of Japanese communities in the years leading up to war and the construction of what officials termed "concentration camps" for enemy aliens. He also considers the aftermath of confinement, including the place of Japanese Americans in postwar civil rights struggles, the long movement by former camp inmates for redress, and the continuing role of the camps as touchstones for nationwide commemoration and debate. Most remarkably, A Tragedy of Democracy is the first book to analyze official policy toward West Coast Japanese Americans within a North American context. Robinson studies confinement on the mainland alongside events in wartime Hawaii, where fears of Japanese Americans justified Army dictatorship, suspension of the Constitution, and the imposition of military tribunals. He similarly reads the treatment of Japanese Americans against Canada's confinement of 22,000 citizens and residents of Japanese ancestry from British Columbia. A Tragedy of Democracy recounts the expulsion of almost 5,000 Japanese from Mexico's Pacific Coast and the poignant story of the Japanese Latin Americans who were kidnapped from their homes and interned in the United States. Approaching Japanese confinement as a continental and international phenomenon, Robinson offers a truly kaleidoscopic understanding of its genesis and outcomes.

  1. The future profile of power generation in North America

    International Nuclear Information System (INIS)

    Eynon, R.T.

    2004-01-01

    This presentation addressed North American power generation issues with particular reference to energy markets, electricity projections, coal supply and natural gas supply. Energy demand is expected to grow due to an increase in population and economic activity. Growth will be tempered by improvements in energy efficiency of equipment and buildings. Production of domestic energy is projected to grow, but not enough to meet energy demands in the United States, thereby increasing levels of imports, primarily natural gas from Canada. One of the key factors in energy markets is the price of natural gas which rose to record levels in 2001 due to strong demand in the winter and tight supplies stemming from low drilling rates in the late 1990s. In the long term, technology improvements will offset price increases. Improvements in gas finding and development technology will continue. Electricity use is projected to grow at slightly slower than historical rates due to improvements in equipment efficiency and investments in demand-side management programs. The growth in electricity sales is led by the commercial sector followed by the industrial sector. The paper emphasized the need for new generating capacity to replace aging generating plants. Coal-fired steam plants have the largest share of power generation in the United States, representing about one-half of total generation, followed by nuclear, natural gas and renewable energy sources. The use of petroleum for generation is small and is expected to decline in the future with the advent of new efficient generating technologies. The use of natural gas for power generation is expected grow significantly due to new technologies for efficient combustion turbines and combined-cycle generators fueled by natural gas. These technologies have low capital costs compared to other technologies and have short lead times for construction. tabs., figs

  2. CO2 consumption and bicarbonate fluxes by chemical weathering in North America.

    Science.gov (United States)

    Jansen, Nils; Hartmann, Jens; Lauerwald, Ronny

    2010-05-01

    Cations released by chemical weathering are mainly counterbalanced by atmospheric/soil CO2 dissolved in water. Existing approaches to quantify CO2 consumption by chemical weathering are mostly based on the parameters runoff and lithology. Land cover is not implemented as predictor in existing regional or global scale models for atmospheric/soil CO2 consumption. Here, bicarbonate fluxes in North American rivers are quantified by an empirical forward model using the predictors runoff, lithology and land cover. The model was calibrated on chemical data from 338 river monitoring stations throughout North America. It was extrapolated to the entire North American continent by applying the model equation spatially explicitly to the geodata used for model calibration. Because silicate mineral weathering derived bicarbonate in rivers originates entirely from atmospheric/soil CO2, but carbonate mineral weathering additionally releases lithogenic bicarbonate, those source minerals are distinguished to quantify the CO2 consumption by chemical weathering. Extrapolation of the model results in a total bicarbonate flux of 51 Mt C a-1 in North America; 70% of which originate from atmospheric/soil CO2. On average, chemical weathering consumes 2.64 t atmospheric/soil C km-2 a-1 (~ 30%-40% above published world average values). For a given runoff and land cover, carbonate-rich sedimentary rocks export the most bicarbonate. However, half of this is assumed to be of lithogenic origin. Thus, the most atmospheric/soil CO2 per runoff is modeled to be consumed by basic plutonics. The least bicarbonate is exported and the least CO2 is consumed per runoff by weathering of metamorphic rocks. Of the distinguished different land cover classes of which urban areas export the most bicarbonate for a given lithology and runoff, followed by shrubs, grasslands and managed lands. For a given runoff and lithology, the least bicarbonate is exported from areas with forested land cover. The model shows 1

  3. First records of Cyclorhipidion fukiense (Eggers) (Coleoptera: Curculionidae: Scolytinae: Xyleborini), an ambrosia beetle native to Asia, in North America.

    Science.gov (United States)

    Hoebeke, E Richard; Rabaglia, Robert J; KnÍŽek, MiloŠ; Weaver, John S

    2018-03-13

    The Asian ambrosia beetle, Cyclorhipidion fukiense (Eggers) was detected for the first time in North America based on three specimens trapped in 2012 from three localities in South Carolina and two other specimens intercepted at the port of Savannah, Georgia, in 2010. The species is characterized, illustrated with high-resolution images, and compared with two other congeneric, adventive species (C. bodoanum and C. pelliculosum) presently established in eastern North America. Morphometric measurements are provided and a provisional key is presented to the species of Cyclorhipidion occurring in North America.

  4. Basic physics program for a low energy antiproton source in North America

    International Nuclear Information System (INIS)

    Bonner, B.E.; Nieto, M.M.

    1987-01-01

    We summarize much of the important science that could be learned at a North American low energy antiproton source. It is striking that there is such a diverse and multidisciplinary program that would be amenable to exploration. Spanning the range from high energy particle physics to nuclear physics, atomic physics, and condensed matter physics, the program promises to offer many new insights into these disparate branches of science. It is abundantly clear that the scientific case for rapidly proceeding towards such a capability in North America is both alluring and strong. 38 refs., 2 tabs

  5. Recent trends, drivers, and projections of carbon cycle processes in forests and grasslands of North America

    Science.gov (United States)

    Domke, G. M.; Williams, C. A.; Birdsey, R.; Pendall, E.

    2017-12-01

    In North America forest and grassland ecosystems play a major role in the carbon cycle. Here we present the latest trends and projections of United States and North American carbon cycle processes, stocks, and flows in the context of interactions with global scale budgets and climate change impacts in managed and unmanaged grassland and forest ecosystems. We describe recent trends in natural and anthropogenic disturbances in these ecosystems as well as the carbon dynamics associated with land use and land cover change. We also highlight carbon management science and tools for informing decisions and opportunities for improving carbon measurements, observations, and projections in forests and grasslands.

  6. Occurrence of Ergasilus megaceros Wilson, 1916, in the sea lamprey and other fishes from North America

    Science.gov (United States)

    Muzzall, Patrick M.; Hudson, Patrick L.

    2004-01-01

    Ergasilus megaceros (Copepoda: Ergasilidae) was recovered from the nasal fossae (lamellae) of the olfactory sac in 1 (1.8%) of 56 sea lampreys, Petromyzon marinus Linne, 1758, collected in May 2002 from the Cheboygan River, Michigan. Although the sea lamprey is a new host record for E. megaceros, this fish species may not be a preferred host because of its low prevalence. Ergasilus megaceros is the second ergasilid species reported from the sea lamprey in North America. This is the third report of an ergasilid species infecting the nasal fossae of fishes in North America, with E. rhinos being the only other species reported from this site.

  7. Korean older intimate partner violence survivors in North America: cultural considerations and practice recommendations.

    Science.gov (United States)

    Shim, Woochan S; Nelson-Becker, Holly

    2009-01-01

    While literature on elder abuse has expanded, elder abuse by intimate partners has been less investigated. Even less is known about intimate partner violence among older Koreans living in North America. This article identifies important cultural considerations for individuals helping the Korean older adult community, beginning with the definition of intimate partner violence in this community and barriers to leaving that include traditional views of the East Asian self. Current practice interventions are discussed and recommendations for future practice such as healing han, the accumulated suffering from years of abuse, are suggested. The ultimate goal of this paper is to expand awareness in order to develop the best culturally competent prevention and intervention practice for Korean older intimate partner violence survivors in North America.

  8. Millennial-scale variability during the last glacial in vegetation records from North America

    Science.gov (United States)

    Jiménez-Moreno, Gonzalo; Anderson, R. Scott; Desprat, S.; Grigg, L.D.; Grimm, E.C.; Heusser, L.E.; Jacobs, Brian F.; Lopez-Martinez, C.; Whitlock, C.L.; Willard, D.A.

    2010-01-01

    High-resolution pollen records from North America show that terrestrial environments were affected by Dansgaard-Oeschger (D-O) and Heinrich climate variability during the last glacial. In the western, more mountainous regions, these climate changes are generally observed in the pollen records as altitudinal movements of climate-sensitive plant species, whereas in the southeast, they are recorded as latitudinal shifts in vegetation. Heinrich (HS) and Greenland (GS) stadials are generally correlated with cold and dry climate and Greenland interstadials (GI) with warm-wet phases. The pollen records from North America confirm that vegetation responds rapidly to millennial-scale climate variability, although the difficulties in establishing independent age models for the pollen records make determination of the absolute phasing of the records to surface temperatures in Greenland somewhat uncertain. ?? 2009 Elsevier Ltd.

  9. The Mesozoic rift basins of eastern North America: Potential reservoir or Explorationist's folly

    Energy Technology Data Exchange (ETDEWEB)

    Pyron, A.

    1991-08-01

    Mesozoic rift basins are found on the East Coast of North America from Georgia to Nova Scotia. The basins formed as a result of extensional activity associated with the breakup of Pangaea. The internal geometry of the basins includes a depositional sequence ranging from coarse fanglomerates to fine-grained siltstones and argillites. Since these Mesozoic rift basins were first studied, they have not been considered to be likely spots for hydrocarbon accumulations. Recently, geologists have reconsidered these Mesozoic basins and have developed a more synergistic approach that suggests that many of these rift basins might be suitable targets for exploration. By analogy, these Mesozoic basins are correlative to similar basins in northwestern Africa, where significant reserved of oil and natural gas have been developed. The similarity between the productive basins in northwestern Africa and the Mesozoic basins of North America and their proximity to major markets provides sufficient rationale to further investigate these basins.

  10. Wild bird surveillance for highly pathogenic avian influenza H5 in North America

    Science.gov (United States)

    Flint, Paul L.; Pearce, John M.; Franson, J. Christian; Derksen, Dirk V.

    2015-01-01

    It is unknown how the current Asian origin highly pathogenic avian influenza H5 viruses arrived, but these viruses are now poised to become endemic in North America. Wild birds harbor these viruses and have dispersed them at regional scales. What is unclear is how the viruses may be moving from the wild bird reservoir into poultry holdings. Active surveillance of live wild birds is likely the best way to determine the true distribution of these viruses. We also suggest that sampling be focused on regions with the greatest risk for poultry losses and attempt to define the mechanisms of transfer to enhance biosecurity. Responding to the recent outbreaks of highly pathogenic avian influenza in North America requires an efficient plan with clear objectives and potential management outcomes.

  11. Gas to Power in North America. Issues surrounding the use of natural gas in the next generation of North American power plants

    International Nuclear Information System (INIS)

    Thorn, T.

    2006-01-01

    In January 2006 a study was concluded on Gas to Power in North America. This study has been prepared for EDI and IGU and is part of the Gas to Power Project, which has been set up in view of the pivotal role power is likely to play in the development of new gas markets and the realization that it will take enormous efforts to achieve the projected growth. In this report the focus is on North America

  12. Extra-regional residence time as a correlate of plant invasiveness: European archaeophytes in North America

    Czech Academy of Sciences Publication Activity Database

    La Sorte, F. A.; Pyšek, Petr

    2009-01-01

    Roč. 90, č. 9 (2009), s. 2589-2597 ISSN 0012-9658 R&D Projects: GA MŠk LC06073 Grant - others:Evropská komise(XE) GOCE-CT-2003-506675 Institutional research plan: CEZ:AV0Z60050516 Keywords : residence time * archaeophyte * North America Subject RIV: EF - Botanics Impact factor: 4.411, year: 2009

  13. How well can fishes prey on zebra mussels in eastern North America?

    Science.gov (United States)

    French, John R. P.

    1993-01-01

    Literature on mollusk-eating fishes was reviewed to determine the potential for different species of fish to control zebra mussels in eastern North America. At least six species are potential predators of zebra mussels because they possess (1) both upper and lower pharyngeal teeth or (2) lower pharyngeal teeth and chewing pads located on the dorsal roof for crushing mollusk shells. Freshwater drum (Aplodinotus grunniens) and two centrarchids, redear sunfish (Lepomis microlophus) and pumpkinseed (L. gibbosus), possess both upper and lower pharyngeal teeth and are likely to consume more zebra mussels than fishes with only lower pharyngeal teeth. Only two catostomid species, copper and river redhorses (Moxostoma hubbsi and M. carinatum), have chewing pads that enable them to crush mollusks. The exotic omnivorous common carp (Cyprinus carpio), possessing lower teeth and a chewing pad, may prey on zebra mussels when aquatic insect larvae, its preferred food, become rare. Managing populations of drum, sunfishes and redhorses to reduce exploitation of large individuals and improve their habitats are suggested as means to intensify biological control of zebra mussels in eastern North America. Other Eurasian molluscivores, the roach (Rutilus rutilus) and the black carp (Mylopharyngodon piceus) should not be introduced into North America because research has shown repeatedly that an introduced biological controller usually does not forage for unwanted pests or reside only in preferred habitats of pests. Drum, sunfishes and redhorses should be preferred over these exotics as biological controllers of zebra mussels in North America because these native fishes will likely occupy newly established habitats of zebra mussels.

  14. Petitioning process for irradiated foods and animal feeds in North America

    International Nuclear Information System (INIS)

    Marcotte, M.; Kunstadt, P.

    1993-01-01

    The lack of sufficient regulatory approvals continues to delay the commercial application of food irradiation in several countries. Often, the regulatory approval process itself appears too challenging and approvals are not even requested. The objective of this paper is to review petition requirements so that researchers and companies in other countries will be able to prepare petitions requesting approval for the import and sale of irradiated foods into North America. (author)

  15. Distributional changes of American martens and fishers in eastern North America, 1699-2001: Chapter 4

    Science.gov (United States)

    Krohn, William B.

    2012-01-01

    Contractions in the geographic distributions of the American marten ( Martes americana) and fi sher ( M. pennanti) in eastern North America south of the St. Lawrence River between Colonial times (ca. 1650–1800) and the fi sher’s recent range expansion (ca. 1930–present) are well documented, but causal factors in these range contractions have only partially been studied. Traditional explanations for range contractions by both species are forest clearing and unregulated trapping; little consideration has been given to alternative explanations. It has been hypothesized that deep snow limits the distribution of fi shers, and that high fi sher populations limit the distribution of martens. I assessed the potential contributions of these factors to observed range contractions for these species by evaluating expected patterns of change in their historical distributions since Colonial times. Using published data on the distribution of martens and fi shers in eastern North America, including early and contemporary fur-harvest records ( n = 60,702), I found that broad-scale changes in their geographic distributions in eastern North America were consistent with 3 of those expectations, and partially so with a 4th. I recognize that retrospective analyses cannot establish the relative importance of land clearing, unregulated trapping, and changing climatic conditions on observed range contractions; nevertheless, when historical data from eastern North America are viewed in the context of long-term climate warming and the results of recent ecological studies, they suggest that traditional arguments may only partially explain historical range contractions for both species. This study further suggests that under a warming climate, northern range boundaries for the fi sher will expand, and southern range boundaries for the American marten will continue to contract.

  16. Feminist Music Therapists in North America: Their Lives and Their Practices

    OpenAIRE

    Sandra L. Curtis

    2015-01-01

    This survey study investigated the lives and practices of those in North America who self-identify as feminist music therapists. Earlier reports from this survey studied: 1) the experiences of music therapists, with a comparison of men, women, and their 1990 counterparts (Curtis, 2013d); 2) the experiences of music therapists who self-identify as community music therapists (Curtis, 2015); and 3) the experiences of music therapists in Canada as they compare with their U.S. counterparts (Curtis...

  17. How does the North American Free Trade Agreement (NAFTA) affect Central America?

    OpenAIRE

    Leamer, Edward E.; Guerra, Alfonso; Kaufman, Martin; Segura, Boris

    1995-01-01

    Most Central American economies experienced slower growth in the 1980s than in the 1960s and 1970s, trailing far behind the Asian Tigers. Contributing to slow growth were severe external shocks, sizable macroeconomic disturbances, and widespread political instability. The challenges Central America faces now may be even greater, conclude the authors, because of Mexican liberalization, continuing instability of the real exchange rate, low savings rates, and, finally, the North American Free Tr...

  18. Simulated bat populations erode when exposed to climate change projections for western North America.

    Directory of Open Access Journals (Sweden)

    Mark A Hayes

    Full Text Available Recent research has demonstrated that temperature and precipitation conditions correlate with successful reproduction in some insectivorous bat species that live in arid and semiarid regions, and that hot and dry conditions correlate with reduced lactation and reproductive output by females of some species. However, the potential long-term impacts of climate-induced reproductive declines on bat populations in western North America are not well understood. We combined results from long-term field monitoring and experiments in our study area with information on vital rates to develop stochastic age-structured population dynamics models and analyzed how simulated fringed myotis (Myotis thysanodes populations changed under projected future climate conditions in our study area near Boulder, Colorado (Boulder Models and throughout western North America (General Models. Each simulation consisted of an initial population of 2,000 females and an approximately stable age distribution at the beginning of the simulation. We allowed each population to be influenced by the mean annual temperature and annual precipitation for our study area and a generalized range-wide model projected through year 2086, for each of four carbon emission scenarios (representative concentration pathways RCP2.6, RCP4.5, RCP6.0, RCP8.5. Each population simulation was repeated 10,000 times. Of the 8 Boulder Model simulations, 1 increased (+29.10%, 3 stayed approximately stable (+2.45%, +0.05%, -0.03%, and 4 simulations decreased substantially (-44.10%, -44.70%, -44.95%, -78.85%. All General Model simulations for western North America decreased by >90% (-93.75%, -96.70%, -96.70%, -98.75%. These results suggest that a changing climate in western North America has the potential to quickly erode some forest bat populations including species of conservation concern, such as fringed myotis.

  19. Recent changes of weather patterns in North America. Progress report for period ending April 1, 1994

    International Nuclear Information System (INIS)

    Kukla, G.J.; Karl, T.

    1994-01-01

    This report contains information dealing with climatic change in North America. Results gathered from present and previous DOE contracts are discussed. These include: usage of the Historical Climatology Network, characteristics of recent climate change, impacts of increasing anthropogenic greenhouse gases, seasonal trends, geographic and seasonal distribution of temperature anomalies, paleoclimates, weather pattern differences between eastern and western regions, daily temperature variations, general circulation models, and results of oceanic circulation

  20. Environmental imperatives reconsidered: demographic crises in western North America during the medieval climatic anomaly.

    Science.gov (United States)

    Jones, T L; Brown, G M; Raab, L M; McVickar, J L; Spaulding, W G; Kennett, D J; York, A; Wlaker, P L

    1999-04-01

    Review of late Holocene paleoenvironmental and cultural sequences from four regions of western North America show striking correlations between drought and changes in subsistence, population, exchange, health, and interpersonal violence during the Medieval Climatic Anomaly (A.D. 800-1350). While ultimate causality is difficult to identify in the archaeological record, synchrony of the environmental and cultural changes and the negative character of many human responses--increased interpersonal violence, deterioration of long-distance exchange relationships, and regional abandonments--suggest widespread demographic crises caused by decreased environmental productivity. The medieval droughts occurred at a unique juncture in the demographic history of western North America when unusually large populations of both hunter-gathers and agriculturalists had evolved highly intensified economies that put them in unprecedented ecological jeopardy. Long-term patterns in the archaeological record are inconsistent with the predicted outcomes of simple adaptation or continuous economic intensification, suggesting that in this instance environmental dynamics played a major role in cultural transformations across a wide expanse of western North America among groups with diverse subsistence strategies. These events suggest that environment should not be overlooked as a potential cause of prehistoric culture change.

  1. Outcomes of planned home births with certified professional midwives: large prospective study in North America.

    Science.gov (United States)

    Johnson, Kenneth C; Daviss, Betty-Anne

    2005-06-18

    To evaluate the safety of home births in North America involving direct entry midwives, in jurisdictions where the practice is not well integrated into the healthcare system. Prospective cohort study. All home births involving certified professional midwives across the United States (98% of cohort) and Canada, 2000. All 5418 women expecting to deliver in 2000 supported by midwives with a common certification and who planned to deliver at home when labour began. Intrapartum and neonatal mortality, perinatal transfer to hospital care, medical intervention during labour, breast feeding, and maternal satisfaction. 655 (12.1%) women who intended to deliver at home when labour began were transferred to hospital. Medical intervention rates included epidural (4.7%), episiotomy (2.1%), forceps (1.0%), vacuum extraction (0.6%), and caesarean section (3.7%); these rates were substantially lower than for low risk US women having hospital births. The intrapartum and neonatal mortality among women considered at low risk at start of labour, excluding deaths concerning life threatening congenital anomalies, was 1.7 deaths per 1000 planned home births, similar to risks in other studies of low risk home and hospital births in North America. No mothers died. No discrepancies were found for perinatal outcomes independently validated. Planned home birth for low risk women in North America using certified professional midwives was associated with lower rates of medical intervention but similar intrapartum and neonatal mortality to that of low risk hospital births in the United States.

  2. Epidemic of Isothiazolinone Allergy in North America: Prevalence Data From the North American Contact Dermatitis Group, 2013-2014.

    Science.gov (United States)

    Zirwas, Matthew J; Hamann, Dathan; Warshaw, Erin M; Maibach, Howard I; Taylor, James S; Sasseville, Denis; DeKoven, Joel G; Fransway, Anthony F; Mathias, C G Toby; Zug, Kathryn A; DeLeo, Vincent A; Fowler, Joseph F; Marks, James G; Pratt, Melanie D; Belsito, Donald V

    Preservative sensitivity patterns evolve with changing use patterns in products. During the last decade, the use of methylisothiazolinone (MI) at higher concentrations in both leave-on and rinse-off products has significantly increased. This is the first North American Contact Dermatitis Group reporting cycle that includes both methylchloroisothiazolinone (MCI)/MI and MI data. The aim of this study was to report the prevalence of isothiazolinone allergy (MCI/MI and MI) in the North American Contact Dermatitis Group patch-test population from January 1, 2013, to December 31, 2014. At 13 centers in North America, 4860 patients were patch tested in a standardized manner with a series of 70 allergens, including MCI/MI 0.01% aqueous (aq) and MI 0.2% aq. Three hundred five patients (6.3%) had a positive reaction to MCI/MI; this is a significant increase from the previous cycle (5.0%, 2011-2012; P = 0.011). Five hundred twenty-one patients (10.7%) had a positive reaction to MI. These 2 isothiazolinones were among the most common preservative allergens in the 2013 to 2014 cycle; 11.9% of patch-tested individuals were allergic to 1 or both isothiazolinones. Individuals with MCI/MI and MI allergy were significantly more likely to have occupationally related skin disease (P dermatitis (P < 0.0001, P = 0.0474). The epidemic of isothiazolinone sensitivity documented in Europe is now in North America. Patch testing with only MCI/MI 0.01% aq will miss approximately half of isothiazolinone allergy cases, whereas testing with only MI 0.2% aq will miss approximately 10% of isothiazolinone allergy cases.

  3. Effects of Temperature, Salinity and Seed Age on Induction of Zostera japonica Germination in North America, USA

    Science.gov (United States)

    Seagrasses can colonize unstructured mudflats either through clonal growth or seed germination and survival. Zostera japonica is an introduced seagrass in North America that has rapidly colonized mudflats along the Pacific Coast, leading to active management of the species. Gro...

  4. Public bikesharing in North America during a period of rapid expansion : understanding business models, industry trends and user impacts.

    Science.gov (United States)

    2014-10-01

    Public bikesharingthe shared use of a bicycle fleetis an innovative transportation strategy that has recently emerged in : major cities around the world, including North America. Information technology (IT)-based bikesharing systems typically p...

  5. Don't Miss the Meeting: Arthroscopy Association of North America Annual Scientific Meeting Reveals Timely and Unique Content.

    Science.gov (United States)

    Lubowitz, James H; Brand, Jefferson C; Provencher, Matthew T; Rossi, Michael J

    2017-04-01

    The Annual Meeting of the Arthroscopy Association of North America (AANA) is notable for timely presentation of innovative research and development. In addition, much of what is presented at the Annual Meeting is never published in Arthroscopy journal. Readers are encouraged to attend the AANA meeting to keep up with the discussion and debate. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  6. Extreme conditions over Europe and North America: role of the Atlantic Multidecadal Variability

    Science.gov (United States)

    Ruprich-Robert, Yohan; Msadek, Rym; Delworth, Tom

    2016-04-01

    The Atlantic Multidecadal Variability (AMV) is the result and possibly the source of marked modulations of the climate over many areas of the globe. For instance, the relatively warm and dry climate of North America throughout the 30-yr interval of 1931-60, during which the Dust Bowl and the 1950's drought occurred, has been linked to the concomitant warm phase of the AMV. During this period relative warm and wet conditions prevailed over Europe. After 1960, the Atlantic began to cool, and for almost three decades the North American climate turned wetter and cooler whereas Europe experienced cooler and dryer conditions. However, the shortness of the historical observations compared to the AMV period suggested by longer proxy (~60-80yr) does not allow to firmly conclude on the causal effect of the AMV. We use a model approach to isolate the causal role of the AMV on the occurrence of extreme events over Europe and North America. We present experiments based on two GFDL global climate models, a low resolution version, CM2.1 and a higher resolution model for the atmospheric component, FLOR. In both model experiments sea surface temperatures in the North Atlantic sector are restored to the observed AMV pattern, while the other basins are left fully coupled. In order to explore and robustly isolate the AMV impacts on extreme events, we use large ensemble simulations (100 members for CM2.1 and 50 for FLOR) that we run for 20 years. We find that a positive phase of the AMV increases the frequency of occurrence of drought over North America and of extremely cold/warm conditions over Northern/Central Europe during winter/summer. Interestingly, we find that the AMV impacts on these extreme conditions are modulated by the Pacific response to the AMV itself. Members that develop a weak Pacific response show more extreme events over Europe whereas those that develop a strong Pacific response show more extreme events over North America.

  7. Projected future distributions of vectors of Trypanosoma cruzi in North America under climate change scenarios.

    Directory of Open Access Journals (Sweden)

    Miroslava Garza

    2014-05-01

    Full Text Available Chagas disease kills approximately 45 thousand people annually and affects 10 million people in Latin America and the southern United States. The parasite that causes the disease, Trypanosoma cruzi, can be transmitted by insects of the family Reduviidae, subfamily Triatominae. Any study that attempts to evaluate risk for Chagas disease must focus on the ecology and biogeography of these vectors. Expected distributional shifts of vector species due to climate change are likely to alter spatial patterns of risk of Chagas disease, presumably through northward expansion of high risk areas in North America.We forecast the future (2050 distributions in North America of Triatoma gerstaeckeri and T. sanguisuga, two of the most common triatomine species and important vectors of Trypanosoma cruzi in the southern United States. Our aim was to analyze how climate change might affect the future shift of Chagas disease in North America using a maximum entropy algorithm to predict changes in suitable habitat based on vector occurrence points and predictive environmental variables. Projections based on three different general circulation models (CCCMA, CSIRO, and HADCM3 and two IPCC scenarios (A2 and B2 were analyzed. Twenty models were developed for each case and evaluated via cross-validation. The final model averages result from all twenty of these models. All models had AUC >0.90, which indicates that the models are robust. Our results predict a potential northern shift in the distribution of T. gerstaeckeri and a northern and southern distributional shift of T. sanguisuga from its current range due to climate change.The results of this study provide baseline information for monitoring the northward shift of potential risk from Chagas disease in the face of climate change.

  8. Avian mercury exposure and toxicological risk across western North America: A synthesis

    Science.gov (United States)

    Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark; Hartman, Christopher; Peterson, Sarah; Evers, David C.; Jackson, Allyson K.; Elliott, John E.; Vander Pol, Stacy S.; Bryan, Colleen E.

    2016-01-01

    Methylmercury contamination of the environment is an important issue globally, and birds are useful bioindicators for mercury monitoring programs. The available data on mercury contamination of birds in western North America were synthesized. Original data from multiple databases were obtained and a literature review was conducted to obtain additional mercury concentrations. In total, 29219 original bird mercury concentrations from 225 species were compiled, and an additional 1712 mean mercury concentrations, representing 19998 individuals and 176 species, from 200 publications were obtained. To make mercury data comparable across bird tissues, published equations of tissue mercury correlations were used to convert all mercury concentrations into blood-equivalent mercury concentrations. Blood-equivalent mercury concentrations differed among species, foraging guilds, habitat types, locations, and ecoregions. Piscivores and carnivores exhibited the greatest mercury concentrations, whereas herbivores and granivores exhibited the lowest mercury concentrations. Bird mercury concentrations were greatest in ocean and salt marsh habitats and lowest in terrestrial habitats. Bird mercury concentrations were above toxicity benchmarks in many areas throughout western North America, and multiple hotspots were identified. Additionally, published toxicity benchmarks established in multiple tissues were summarized and translated into a common blood-equivalent mercury concentration. Overall, 66% of birds sampled in western North American exceeded a blood-equivalent mercury concentration of 0.2 μg/g wet weight (ww; above background levels), which is the lowest-observed effect level, 28% exceeded 1.0 μg/g ww (moderate risk), 8% exceeded 3.0 μg/g ww (high risk), and 4% exceeded 4.0 μg/g ww (severe risk). Mercury monitoring programs should sample bird tissues, such as adult blood and eggs, that are most-easily translated into tissues with well-developed toxicity benchmarks and that

  9. Unrecognized Ingestion of Toxoplasma gondii Oocysts Leads to Congenital Toxoplasmosis and Causes Epidemics in North America

    Science.gov (United States)

    Boyer, Kenneth; Hill, Dolores; Mui, Ernest; Wroblewski, Kristen; Karrison, Theodore; Dubey, J. P.; Sautter, Mari; Noble, A. Gwendolyn; Withers, Shawn; Swisher, Charles; Heydemann, Peter; Hosten, Tiffany; Babiarz, Jane; Lee, Daniel

    2011-01-01

    (See the Editorial Commentary by Linn, on pages 1090–1.) Background. Congenital toxoplasmosis presents as severe, life-altering disease in North America. If mothers of infants with congenital toxoplasmosis could be identified by risks, it would provide strong support for educating pregnant women about risks, to eliminate this disease. Conversely, if not all risks are identifiable, undetectable risks are suggested. A new test detecting antibodies to sporozoites demonstrated that oocysts were the predominant source of Toxoplasma gondii infection in 4 North American epidemics and in mothers of children in the National Collaborative Chicago-based Congenital Toxoplasmosis Study (NCCCTS). This novel test offered the opportunity to determine whether risk factors or demographic characteristics could identify mothers infected with oocysts. Methods. Acutely infected mothers and their congenitally infected infants were evaluated, including in-person interviews concerning risks and evaluation of perinatal maternal serum samples. Results. Fifty-nine (78%) of 76 mothers of congenitally infected infants in NCCCTS had primary infection with oocysts. Only 49% of these mothers identified significant risk factors for sporozoite acquisition. Socioeconomic status, hometown size, maternal clinical presentations, and ethnicity were not reliable predictors. Conclusions. Undetected contamination of food and water by oocysts frequently causes human infections in North America. Risks are often unrecognized by those infected. Demographic characteristics did not identify oocyst infections. Thus, although education programs describing hygienic measures may be beneficial, they will not suffice to prevent the suffering and economic consequences associated with congenital toxoplasmosis. Only a vaccine or implementation of systematic serologic testing of pregnant women and newborns, followed by treatment, will prevent most congenital toxoplasmosis in North America. PMID:22021924

  10. [Conservation tillage systems in North America and their significance for China].

    Science.gov (United States)

    Yang, Xueming; Zhang, Xiaoping; Fang, Huajun; Liang, Aizhen; Qi, Xiaoning; Wang, Yang

    2004-02-01

    Soil degradation through erosion and desertification reduces soil productivity, and is a serious problem in agricultural production of China. To avert our arable land from further degradation, soil management must be shifted from degrading tillage to conservation practices. Over viewing the technology used in the 20th century for controlling soil degradation from erosion, conservation tillage developed in the United States and adopted in South America and Africa is one of the most successful measures to overcome soil degradation problems. This paper reviewed the historical development and the current situation of conservation tillage systems used in North and South America, with special reference to their effects on soil erosion control and soil quality. The increasing adoption of conservation tillage systems in North and South America and Africa followed an enhanced awareness of the increasing risk of soil erosion and the high cost of fuel associated with conventional tillage. Many crucial points for successfully adopting conservation tillage systems were emphasized, such as equipment/tool development and chemical weed control. Adopting conservation tillage could provide China with low-priced means of reducing soil degradation and improving soil and water quality.

  11. Late Holocene Drought Variability in Eastern North America: Evidence From the Peatland Archive

    Science.gov (United States)

    Booth, R. K.; Jackson, S. T.

    2006-12-01

    Tree-ring based drought chronologies from semi-arid regions of western North America have revealed substantial variability in water balance during the past 1000 years, including episodes of persistent drought more severe than any observed during historical times. Delimitation of regional and continental-scale footprints of these past drought events, including their spatial patterning in humid regions where moisture-sensitive paleoclimate records are scarce, is critical to understanding their dynamics and potential causes. Ombrotrophic peatlands are scattered throughout humid regions of North America at mid-latitudes and represent an underutilized source of multidecadal-scale information on past moisture variations. We are developing a spatial network of peatland-derived paleoclimate and paleoecological records in eastern North America, in an effort to 1) determine whether large, decadal to multidecadal droughts of the past several thousand years were spatially and temporally coherent, 2) assess whether the magnitude of past drought events was sufficient to force ecological change in terrestrial ecosystems, and 3) assess the underlying mechanisms and dynamics of widespread drought in North America. We have completed water-level reconstructions based on testate-amoeba assemblages from two ombrotrophic peatlands in mid-continental North America, Hole in the Bog (NC Minnesota) and Minden Bog (SE Michgian). We also have developed reconstructions from three Sphagnum-dominated kettle peatlands, South Rhody Peatland (NC Michigan), Hornet Peatland (NW Wisconsin), and Irwin Smith Peatland (NE Michigan). Although these kettle peatlands are not truly ombrotrophic, high-magnitude water-table fluctuations should still be attributable to climate variability, and we use these records to supplement our interpretation of regional climate history. Our results indicate that all high-magnitude fluctuations in water balance were spatially extensive, affecting bog-surface moisture

  12. 75 FR 56991 - Grant of Authority for Subzone Status Michelin North America, Inc. (Tire Distribution and Wheel...

    Science.gov (United States)

    2010-09-17

    ... Status Michelin North America, Inc. (Tire Distribution and Wheel Assembly) Baltimore, MD Pursuant to its...; Now, therefore, the Board hereby grants authority for subzone status for activity related to tire and tire accessories warehousing and distribution and wheel assembly at the facility of Michelin North...

  13. Thermal state of permafrost in North America: A contribution to the international polar year

    Science.gov (United States)

    Smith, S.L.; Romanovsky, V.E.; Lewkowicz, A.G.; Burn, C.R.; Allard, M.; Clow, G.D.; Yoshikawa, K.; Throop, J.

    2010-01-01

    A snapshot of the thermal state of permafrost in northern North America during the International Polar Year (IPY) was developed using ground temperature data collected from 350 boreholes. More than half these were established during IPY to enhance the network in sparsely monitored regions. The measurement sites span a diverse range of ecoclimatic and geological conditions across the continent and are at various elevations within the Cordillera. The ground temperatures within the discontinuous permafrost zone are generally above -3°C, and range down to -15°C in the continuous zone. Ground temperature envelopes vary according to substrate, with shallow depths of zero annual amplitude for peat and mineral soils, and much greater depths for bedrock. New monitoring sites in the mountains of southern and central Yukon suggest that permafrost may be limited in extent. In concert with regional air temperatures, permafrost has generally been warming across North America for the past several decades, as indicated by measurements from the western Arctic since the 1970s and from parts of eastern Canada since the early 1990s. The rates of ground warming have been variable, but are generally greater north of the treeline. Latent heat effects in the southern discontinuous zone dominate the permafrost thermal regime close to 0°C and allow permafrost to persist under a warming climate. Consequently, the spatial diversity of permafrost thermal conditions is decreasing over time.

  14. History and development of Carboniferous palynology in North America during the early and middle twentieth century

    Energy Technology Data Exchange (ETDEWEB)

    Cross, A.T.; Kosanke, R.M. [Michigan State University, East Lansing, MI (United States). Dept. of Geological Sciences

    1995-12-31

    Three main roots of upper Palaeozoic palynology in North America date from the opening of the twentieth century. These are Gresley`s recognition of spores in Iowa coal balls in 1901, analyses of spores by Sellards from Mazon Creek compressions in 1902, and Thiessen`s analyses of dispersed spores from coal maceration and thin sections in 1913. The Pollen Analysis Circular brought workers into contact in the 1940s and generated interest in older fossils. The Paleobotanical Section of the Botanical Society of America (1936) and the Coal Geology Division of the Geological Society of America (1955) encouraged palynologists to participate in meetings and field trips. Fundamental papers by Schopf et al. in 1944 and Kosanke in 1950 established Carboniferous palynology in North America. Active teaching and research centers at the University of Chicago in the 1920s and the University of Illinois and Coe College in the 1930s spawned new palynological centers, particularly throughout the Midwest. Palynological contributions on dispersed spores, mainly from coals and associated rocks, appeared from educational centers from 1929 through the 1950s. Limited reviews of early researches at early palynologic centers are here included by region. Palynology applied to petroleum exploration appeared in the 1940s and major petroleum companies had palynology laboratories in place by 1960. The first international palynology journals appeared in the 1950s and catalogs first appeared in the mid-1960s, except the Catalog of Fossil Spores and Pollen, which began in 1957. The first specific palynology organization, the American Association of Stratigraphic Palynologisst, was founded in 1968. 304 refs., 38 figs

  15. Past climate change and plant evolution in Western North America: a case study in Rosaceae.

    Science.gov (United States)

    Töpel, Mats; Antonelli, Alexandre; Yesson, Chris; Eriksen, Bente

    2012-01-01

    Species in the ivesioid clade of Potentilla (Rosaceae) are endemic to western North America, an area that underwent widespread aridification during the global temperature decrease following the Mid-Miocene Climatic Optimum. Several morphological features interpreted as adaptations to drought are found in the clade, and many species occupy extremely dry habitats. Recent phylogenetic analyses have shown that the sister group of this clade is Potentilla section Rivales, a group with distinct moist habitat preferences. This has led to the hypothesis that the ivesioids (genera Ivesia, Horkelia and Horkeliella) diversified in response to the late Tertiary aridification of western North America. We used phyloclimatic modeling and a fossil-calibrated dated phylogeny of the family Rosaceae to investigate the evolution of the ivesioid clade. We have combined occurrence- and climate data from extant species, and used ancestral state reconstruction to model past climate preferences. These models have been projected into paleo-climatic scenarios in order to identify areas where the ivesioids may have occurred. Our analysis suggests a split between the ivesioids and Potentilla sect. Rivales around Late Oligocene/Early Miocene (∼23 million years ago, Ma), and that the ivesioids then diversified at a time when summer drought started to appear in the region. The clade is inferred to have originated on the western slopes of the Rocky Mountains from where a westward range expansion to the Sierra Nevada and the coast of California took place between ∼12-2 Ma. Our results support the idea that climatic changes in southwestern North America have played an important role in the evolution of the local flora, by means of in situ adaptation followed by diversification.

  16. Outflows, dusty cores, and a burst of star formation in the North America and Pelican nebulae

    Energy Technology Data Exchange (ETDEWEB)

    Bally, John [Department of Astrophysical and Planetary Sciences, University of Colorado, UCB 389, Boulder, CO 80309 (United States); Ginsburg, Adam [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei Munchen (Germany); Probst, Ron [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Reipurth, Bo [Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii at Manoa, 640 North A' ohoku Place, Hilo, HI 96720 (United States); Shirley, Yancy L. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Stringfellow, Guy S., E-mail: John.Bally@colorado.edu, E-mail: aginsburg@eso.org, E-mail: probst@noao.edu, E-mail: reipurth@ifa.hawaii.edu, E-mail: yshirley@as.arizona.edu, E-mail: Guy.Stringfellow@colorado.edu [Center for Astrophysics and Space Astronomy, University of Colorado, UCB 389, Boulder, CO 80309 (United States)

    2014-12-01

    We present observations of near-infrared 2.12 μm molecular hydrogen outflows emerging from 1.1 mm dust continuum clumps in the North America and Pelican Nebula (NAP) complex selected from the Bolocam Galactic Plane Survey (BGPS). Hundreds of individual shocks powered by over 50 outflows from young stars are identified, indicating that the dusty molecular clumps surrounding the NGC 7000/IC 5070/W80 H II region are among the most active sites of ongoing star formation in the solar vicinity. A spectacular X-shaped outflow, MHO 3400, emerges from a young star system embedded in a dense clump more than a parsec from the ionization front associated with the Pelican Nebula (IC 5070). Suspected to be a binary, the source drives a pair of outflows with orientations differing by 80°. Each flow exhibits S-shaped symmetry and multiple shocks indicating a pulsed and precessing jet. The 'Gulf of Mexico', located south of the North America Nebula (NGC 7000), contains a dense cluster of molecular hydrogen objects (MHOs), Herbig-Haro (HH) objects, and over 300 young stellar objects (YSOs), indicating a recent burst of star formation. The largest outflow detected thus far in the North America and Pelican Nebula complex, the 1.6 parsec long MHO 3417 flow, emerges from a 500 M {sub ☉} BGPS clump and may be powered by a forming massive star. Several prominent outflows such as MHO 3427 appear to be powered by highly embedded YSOs only visible at λ > 70 μm. An 'activity index' formed by dividing the number of shocks by the mass of the cloud containing their source stars is used to estimate the relative evolutionary states of Bolocam clumps. Outflows can be used as indicators of the evolutionary state of clumps detected in millimeter and submillimeter dust continuum surveys.

  17. Abatement of atmospheric emissions in North America: Progress to date and promise for the future

    International Nuclear Information System (INIS)

    Ellis, E.C.; Erbes, R.E.; Grott, J.K.

    1990-01-01

    Much progress has been made in acidic rain abatement in North America. This progress is examined with a focus on man-made emissions of sulfur dioxide and nitrogen oxides that contribute to acidic deposition. A review of US historical trends of SO 2 and nitrogen oxides emissions since 1900 and projections of future emissions through the end of this century shoe emissions of SO 2 decreasing from a peak in 1970 of 29 Tg/yr to about 26 Tg/yr, but nitrogen oxides emissions continuing an upward trend to about 25 Tg/yr. In Canada, SO 2 , NO and NO 2 emissions are less than 20% of those in the US, and the trends are similar, with SO 2 showing future decreases and NO and NO 2 continuing to increase. Future industry in North America is expected to emit much lower levels of SO 2 , NO, and NO 2 . Technology is also available to limit nitrogen oxides emissions from future motor vehicles. Recent acidic deposition legislation in the US Congress to reduce electric utility and industrial emissions of SO 2 by 9 to 13 Tg/yr is reviewed. The estimates of the cost to implement the proposals range from $2 billion to $23 billion over a 5-year period. Retrofitting existing utility and industrial boilers for maximum SO 2 , NO, and NO 2 reduction carries the highest price tag. Several environmental policy options are explored for preventing emission increases and also promoting decreases in future emissions of SO 2 , NO, and NO 2 in North America. Focus on nitrogen oxides emissions may be critical because population growth could cause significant increases in NO and NO 2 from motor vehicle use

  18. Past climate change and plant evolution in Western North America: a case study in Rosaceae.

    Directory of Open Access Journals (Sweden)

    Mats Töpel

    Full Text Available Species in the ivesioid clade of Potentilla (Rosaceae are endemic to western North America, an area that underwent widespread aridification during the global temperature decrease following the Mid-Miocene Climatic Optimum. Several morphological features interpreted as adaptations to drought are found in the clade, and many species occupy extremely dry habitats. Recent phylogenetic analyses have shown that the sister group of this clade is Potentilla section Rivales, a group with distinct moist habitat preferences. This has led to the hypothesis that the ivesioids (genera Ivesia, Horkelia and Horkeliella diversified in response to the late Tertiary aridification of western North America. We used phyloclimatic modeling and a fossil-calibrated dated phylogeny of the family Rosaceae to investigate the evolution of the ivesioid clade. We have combined occurrence- and climate data from extant species, and used ancestral state reconstruction to model past climate preferences. These models have been projected into paleo-climatic scenarios in order to identify areas where the ivesioids may have occurred. Our analysis suggests a split between the ivesioids and Potentilla sect. Rivales around Late Oligocene/Early Miocene (∼23 million years ago, Ma, and that the ivesioids then diversified at a time when summer drought started to appear in the region. The clade is inferred to have originated on the western slopes of the Rocky Mountains from where a westward range expansion to the Sierra Nevada and the coast of California took place between ∼12-2 Ma. Our results support the idea that climatic changes in southwestern North America have played an important role in the evolution of the local flora, by means of in situ adaptation followed by diversification.

  19. Analysis of ionospheric disturbances associated with powerful cyclones in East Asia and North America

    Science.gov (United States)

    Li, Wang; Yue, Jianping; Yang, Yang; Li, Zhen; Guo, Jinyun; Pan, Yi; Zhang, Kefei

    2017-08-01

    East Asia and North America are the regions most heavily affected by powerful cyclones. In this paper we investigate the morphological characteristics of ionospheric disturbances induced by cyclones in different continents. The global ionosphere map supplied by the Center for Orbit Determination in Europe (CODE), International Reference Ionosphere Model (IRI) 2012, and Wallops Island ionosonde station data are used to analyse the ionospheric variations during powerful typhoons/hurricanes in East Asia and North America, respectively. After eliminating the ionospheric anomalies due to the solar-terrestrial environment, the total electron content (TEC) time series over the point with maximum wind speed is detected by the sliding interquartile range method. The results indicate that significant ionospheric disturbances are observed during powerful tropical cyclones in East Asia and North America, respectively, and that all the ionospheric anomalies are positive. In addition, the extent and magnitude of travelling ionospheric disturbances are associated with the category of tropical cyclone, and the extent of TEC anomalies in longitude is more pronounced than that in latitude. Furthermore, the maximum ionospheric anomaly does not coincide with the eye of the storm, but appears in the region adjacent to the centre. This implies that ionospheric disturbances at the edges of cyclones are larger than those in the eye of the winds. The phenomenon may be associated with the gravity waves which are generated by strong convective cells that occur in the spiral arms of tropical cyclones. This comprehensive analysis suggests that the presence of powerful typhoons/hurricanes may be a possible source mechanism for ionospheric anomalies.

  20. Comments on the current status of aquaculture in heated effluents in North America

    International Nuclear Information System (INIS)

    Ayles, G.B.

    1976-01-01

    At the current rate of increase the world demand for fish protein will soon far exceed the supply. The culture of aquatic organisms in low-grade waste heat could be a significant source of animal protein. There are at present thriving trout culture and catfish culture industries in North America. There are a number of small-scale research and commercial aquaculture projects currently in operation and numerous studies have been carried out. However, the knowledge gained has not had a significant impact on waste heat aquaculture development. (author)

  1. Economic suicides in the Great Recession in Europe and North America.

    Science.gov (United States)

    Reeves, Aaron; McKee, Martin; Stuckler, David

    2014-09-01

    There has been a substantial rise in 'economic suicides' in the Great Recessions afflicting Europe and North America. We estimate that the Great Recession is associated with at least 10 000 additional economic suicides between 2008 and 2010. A critical question for policy and psychiatric practice is whether these suicide rises are inevitable. Marked cross-national variations in suicides in the recession offer one clue that they are potentially avoidable. Job loss, debt and foreclosure increase risks of suicidal thinking. A range of interventions, from upstream return-to-work programmes through to antidepressant prescriptions may help mitigate suicide risk during economic downturn. Royal College of Psychiatrists.

  2. Time-Series Analysis of U.S. Pistachio Export Demand in North America

    OpenAIRE

    Zheng, Zijuan; Saghaian, Sayed H.

    2011-01-01

    This study identifys the main factors influencing U.S. pistachio export demand in North America-i.e., to Canada and Mexico. A double-log econometric model is estimated using data for 1989-2009. The main findings indicate that Canadian GDP, U.S. walnut export prices, and food safety concerns explain the majorityof the pistachio import demand variation in Canada, wheras Iranian pistachio export prices, the real exchange rate between the Mexican peso and the U.S. dollar, and U.S. pecan export pr...

  3. Discrimination between underground explosions and earthquakes using discriminant functions: Examples for Eurasia and North America

    International Nuclear Information System (INIS)

    Nowroozi, A.A.

    1986-01-01

    Discriminant functions are extensively used as a technical tool in educational and psychological research as well as in some branches of geological sciences. The application of this technique to the problem of discrimination between underground nuclear explosions and earthquakes has been reported. Here we apply this technique to a known population of underground nuclear explosions and earthquakes for the determination of various statistical parameters needed for setting up the discriminant function equations for discrimination between unknown population of earthquakes, anomalous events, and underground explosions, then we classify earthquakes, explosions and anomalous events in Eurasia and North America

  4. The status of UV/EB curable product in North America: 1998-1999

    International Nuclear Information System (INIS)

    Lawson, K.

    1999-01-01

    This author has previously reported survey results showing that the use of UV/EB materials has grown at a compound rate of about 10% per annum over the last decade. Together, with about 130 members of RadTech International North America, representing 90 organizations, we have updated and assessed the growth and activities of the industry. The panelists represent a cross section of end users, raw material and equipment suppliers, as well as formulators and consultants. Using a modified Delphi process with five separate survey rounds, a reasonable assessment was made of the advantages, disadvantages, growth rate and growth opportunities of this exciting technology

  5. A regional high-resolution carbon flux inversion of North America for 2004

    Science.gov (United States)

    Schuh, A. E.; Denning, A. S.; Corbin, K. D.; Baker, I. T.; Uliasz, M.; Parazoo, N.; Andrews, A. E.; Worthy, D. E. J.

    2010-05-01

    Resolving the discrepancies between NEE estimates based upon (1) ground studies and (2) atmospheric inversion results, demands increasingly sophisticated techniques. In this paper we present a high-resolution inversion based upon a regional meteorology model (RAMS) and an underlying biosphere (SiB3) model, both running on an identical 40 km grid over most of North America. Current operational systems like CarbonTracker as well as many previous global inversions including the Transcom suite of inversions have utilized inversion regions formed by collapsing biome-similar grid cells into larger aggregated regions. An extreme example of this might be where corrections to NEE imposed on forested regions on the east coast of the United States might be the same as that imposed on forests on the west coast of the United States while, in reality, there likely exist subtle differences in the two areas, both natural and anthropogenic. Our current inversion framework utilizes a combination of previously employed inversion techniques while allowing carbon flux corrections to be biome independent. Temporally and spatially high-resolution results utilizing biome-independent corrections provide insight into carbon dynamics in North America. In particular, we analyze hourly CO2 mixing ratio data from a sparse network of eight towers in North America for 2004. A prior estimate of carbon fluxes due to Gross Primary Productivity (GPP) and Ecosystem Respiration (ER) is constructed from the SiB3 biosphere model on a 40 km grid. A combination of transport from the RAMS and the Parameterized Chemical Transport Model (PCTM) models is used to forge a connection between upwind biosphere fluxes and downwind observed CO2 mixing ratio data. A Kalman filter procedure is used to estimate weekly corrections to biosphere fluxes based upon observed CO2. RMSE-weighted annual NEE estimates, over an ensemble of potential inversion parameter sets, show a mean estimate 0.57 Pg/yr sink in North America

  6. Asia, North America lead way in growth of NGL, LPG trade

    International Nuclear Information System (INIS)

    Otto, K.; Gist, R.; Whitley, C.; Haun, R.

    1998-01-01

    Recent analyses of world NGL trade indicate that important changes in LPG supply and demand are under way in Asia and North America. LPG markets in the 1990s reflect a rapidly shifting balance between East-of-Suez and West-of-Suez markets. This shift has increased concern about availability of future LPG supplies for Asia. The paper discusses world developments, East versus West of Suez, end uses and supplies in Asia, Canadian ethane, propane, butane, and natural gasoline, Mexican ethane, LPG, and natural gasoline, US ethane, propane, butanes, and iso-C 4 and C 5

  7. Risk factors for equine fractures in Thoroughbred flat racing in North America

    OpenAIRE

    Georgopoulos, Stamatis Panagiotis; Parkin, Tim D.H.

    2017-01-01

    The aim of this paper is to identify risk factors associated with equine fractures in flat horse racing of Thoroughbreds in North America. Equine fractures were defined as any fracture sustained by a horse during a race. This was a cohort study that made use of all starts from the racecourses reporting injuries. The analysis was based on 2,201,152 racing starts that represent 91% of all official racing starts in the USA and Canada from 1 st January 2009–31 st December 2014. Approximately 3,99...

  8. Role of Transtension in Rifting at the Pacific-North America Plate Boundary

    Science.gov (United States)

    Stock, J. M.

    2011-12-01

    Transtensional plate motion can be accommodated either in a localized zone of transtensional rifting or over a broader region. Broader zones of deformation can be classified either as diffuse deformation or strain partitioning (one or more major strike-slip shear zones geographically offset from a region of a extensional faulting). The Pacific-North America plate boundary in southwestern North America was transtensional during much of its history and has exhibited the full range of these behaviors at different spatial scales and in different locations, as recorded by fault motions and paleomagnetic rotations. Here we focus on the northern Gulf of California part of the plate boundary (Upper and Lower Delfin basin segments), which has been in a zone of transtensional Pacific-North America plate boundary motion ever since the middle Miocene demise of adjacent Farallon-derived microplates. Prior to the middle Miocene, during the time of microplate activity, this sector of North America experienced basin-and-range normal faults (core complexes) in Sonora. However there is no evidence of continued extensional faulting nor of a Gulf-related topographic depression until after ca 12 Ma when a major ignimbrite (Tuff of San Felipe/ Ignimbrite of Hermosillo) was deposited across the entire region of the future Gulf of California rift in this sector. After 12 Ma, faults disrupted this marker bed in eastern Baja California and western Sonora, and some major NNW-striking right-lateral faults are inferred to have developed near the Sonoran coast causing offset of some of the volcanic facies. However, there are major tectonic rotations of the volcanic rocks in NE Baja California between 12 and 6 Ma, suggesting that the plate boundary motion was still occurring over a broad region. By contrast, after about 6 Ma, diminished rotations in latest Miocene and Pliocene volcanic rocks, as well as fault slip histories, show that plate boundary deformation became localized to a narrower

  9. Price interactions and discovery among natural gas spot markets in North America

    International Nuclear Information System (INIS)

    Park, Haesun; Mjelde, James W.; Bessler, David A.

    2008-01-01

    Recent advances in modeling causal flows with time series analysis are used to study relationships among eight North American natural gas spot market prices. Results indicate that the Canadian and US natural gas market is a single highly integrated market. Further results indicate that price discovery tends to reflect both regions of excess demand and supply. Across North America, Malin Hub in Oregon, Chicago Hub, Illinois, Waha, Texas, and Henry Hub, Louisiana region, are the most important markets for price discovery. Opal Hub in Wyoming is an information sink in contemporaneous time, receiving price information but passing on no price information. AECO Hub in Alberta, Canada, receives price signals from several markets and passes on information to Opal and the Oklahoma region. (author)

  10. First experience concerning the seismic behavior of an electric power system in eastern North America

    International Nuclear Information System (INIS)

    Pierre, J.R.

    1991-01-01

    The November 25, 1988, Saguenay earthquake of magnitude M b L g = 6.5 occurred in the province of Quebec, Canada. It represents the first strong event in eastern North America for which the seismic behavior of a power system is documented. The paper describes the seismic performance of the main components of the power system with emphasis on damages to the substation's equipment and on the triggering of control and protection devices by the seismic waves. Performance of the network is analyzed taking in account the seismological and strong ground motion features. Attention is drawn to general observations related to soil conditions and topographical relief. These data, when extrapolated to the eastern North American context, indicate that caution must be exercised concerning the seismic resistance of lifelines in eastern Canada and United States

  11. Upper Mantle Shear Wave Structure Beneath North America From Multi-mode Surface Wave Tomography

    Science.gov (United States)

    Yoshizawa, K.; Ekström, G.

    2008-12-01

    The upper mantle structure beneath the North American continent has been investigated from measurements of multi-mode phase speeds of Love and Rayleigh waves. To estimate fundamental-mode and higher-mode phase speeds of surface waves from a single seismogram at regional distances, we have employed a method of nonlinear waveform fitting based on a direct model-parameter search using the neighbourhood algorithm (Yoshizawa & Kennett, 2002). The method of the waveform analysis has been fully automated by employing empirical quantitative measures for evaluating the accuracy/reliability of estimated multi-mode phase dispersion curves, and thus it is helpful in processing the dramatically increasing numbers of seismic data from the latest regional networks such as USArray. As a first step toward modeling the regional anisotropic shear-wave velocity structure of the North American upper mantle with extended vertical resolution, we have applied the method to long-period three-component records of seismic stations in North America, which mostly comprise the GSN and US regional networks as well as the permanent and transportable USArray stations distributed by the IRIS DMC. Preliminary multi-mode phase-speed models show large-scale patterns of isotropic heterogeneity, such as a strong velocity contrast between the western and central/eastern United States, which are consistent with the recent global and regional models (e.g., Marone, et al. 2007; Nettles & Dziewonski, 2008). We will also discuss radial anisotropy of shear wave speed beneath North America from multi-mode dispersion measurements of Love and Rayleigh waves.

  12. Herbarium specimens reveal the footprint of climate change on flowering trends across north-central North America.

    Science.gov (United States)

    Calinger, Kellen M; Queenborough, Simon; Curtis, Peter S

    2013-08-01

    Shifting flowering phenology with rising temperatures is occurring worldwide, but the rarity of co-occurring long-term observational and temperature records has hindered the evaluation of phenological responsiveness in many species and across large spatial scales. We used herbarium specimens combined with historic temperature data to examine the impact of climate change on flowering trends in 141 species collected across 116,000 km(2) in north-central North America. On average, date of maximum flowering advanced 2.4 days °C(-1), although species-specific responses varied from - 13.5 to + 7.3 days °C(-1). Plant functional types exhibited distinct patterns of phenological responsiveness with significant differences between native and introduced species, among flowering seasons, and between wind- and biotically pollinated species. This study is the first to assess large-scale patterns of phenological responsiveness with broad species representation and is an important step towards understanding current and future impacts of climate change on species performance and biodiversity. © 2013 The Authors. Ecology Letters published by John Wiley & Sons Ltd and CNRS.

  13. An exploration of common reed (Phragmites australis bioenergy potential in North America

    Directory of Open Access Journals (Sweden)

    R. Vaičekonytė

    2014-10-01

    Full Text Available In North America, reed (Phragmites australis is typically considered to be a weed although it provides important ecosystem services. Small, sparse, patchy or mixed reedbeds are more suitable as habitat for many species than extensive dense reedbeds, whose habitat functions can be enhanced by the selective removal of biomass. We propose that above-ground reed biomass could be harvested for bioenergy, at the same time improving habitat for biodiversity by thinning or fragmenting the more extensive reedbeds. Biofuel pellets manufactured from reeds harvested at Montréal (Canada had moisture content 6.4 %, energy content 16.9 kJ g-1 (dry mass, ash content 3.44 %, and chloride content 1962 ppm. Thus, reed as a material for fuel pellet manufacture is similar to switchgrass (Panicum virgatum, which is commonly cultivated for that purpose and requires higher inputs than harvested wild reed. We discuss these findings in the context of environmental considerations and conclude that the bioenergy potential of reed could most expediently be realised in North America by combining material harvested from the widespread spontaneously occurring reedbeds with organic waste from other sources to create mixed biofuels. However, reeds with high levels of chlorine, sulphur or metals should not be burned to avoid air pollution or equipment damage unless these problems are mitigated by means of appropriate season of harvest, equipment, combustion regime, or use of a mixed feedstock.

  14. Infectious disease in cervids of North America: data, models, and management challenges.

    Science.gov (United States)

    Conner, Mary Margaret; Ebinger, Michael Ryan; Blanchong, Julie Anne; Cross, Paul Chafee

    2008-01-01

    Over the past two decades there has been a steady increase in the study and management of wildlife diseases. This trend has been driven by the perception of an increase in emerging zoonotic diseases and the recognition that wildlife can be a critical factor for controlling infectious diseases in domestic animals. Cervids are of recent concern because, as a group, they present a number of unique challenges. Their close ecological and phylogenetic relationship to livestock species places them at risk for receiving infections from, and reinfecting livestock. In addition, cervids are an important resource; revenue from hunting and viewing contribute substantially to agency budgets and local economies. A comprehensive coverage of infectious diseases in cervids is well beyond the scope of this chapter. In North America alone there are a number of infectious diseases that can potentially impact cervid populations, but for most of these, management is not feasible or the diseases are only a potential or future concern. We focus this chapter on three diseases that are of major management concern and the center of most disease research for cervids in North America: bovine tuberculosis, chronic wasting disease, and brucellosis. We discuss the available data and recent advances in modeling and management of these diseases.

  15. The Contribution of Soils to North America's Current and Future Climate

    Science.gov (United States)

    Mayes, M. A.; Reed, S.; Thornton, P. E.; Lajtha, K.; Bailey, V. L.; Shrestha, G.; Jastrow, J. D.; Torn, M. S.

    2015-12-01

    This presentation will cover key aspects of the terrestrial soil carbon cycle in North America and the US for the upcoming State of the Carbon Cycle Report (SOCCRII). SOCCRII seeks to summarize how natural processes and human interactions affect the global carbon cycle, how socio-economic trends affect greenhouse gas concentrations in the atmosphere, and how ecosystems are influenced by and respond to greenhouse gas emissions, management decisions, and concomitant climate effects. Here, we will summarize the contemporary understanding of carbon stocks, fluxes, and drivers in the soil ecosystem compartment. We will highlight recent advances in modeling the magnitude of soil carbon stocks and fluxes, as well as the importance of remaining uncertainties in predicting soil carbon cycling and its relationship with climate. Attention will be given to the role of uncertainties in predicting future fluxes from soils, and how those uncertainties vary by region and ecosystem. We will also address how climate feedbacks and management decisions can enhance or minimize future climatic effects based on current understanding and observations, and will highlight select research needs to improve our understanding of the balance of carbon in soils in North America.

  16. A population study of urine glycerol concentrations in elite athletes competing in North America.

    Science.gov (United States)

    Kelly, Brian N; Madsen, Myke; Sharpe, Ken; Nair, Vinod; Eichner, Daniel

    2013-01-01

    Glycerol is an endogenous substance that is on the World Anti-Doping Agency's list of prohibited threshold substances due to its potential use as a plasma volume expansion agent. The WADA has set the threshold for urine glycerol, including measurement uncertainty, at 1.3 mg/mL. Glycerol in circulation largely comes from metabolism of triglycerides in order to meet energy requirements and when the renal threshold is eclipsed, glycerol is excreted into urine. In part due to ethnic differences in postprandial triglyceride concentrations, we investigated urine glycerol concentrations in a population of elite athletes competing in North America and compared the results to those of athletes competing in Europe. 959 urine samples from elite athletes competing in North America collected for anti-doping purposes were analyzed for urine glycerol concentrations by a gas chromatography mass-spectrometry method. Samples were divided into groups according to: Timing (in- or out-of-competition), Class (strength, game, or endurance sports) and Gender. 333 (34.7%) samples had undetectable amounts of glycerol (sport classes. Copyright © 2013 John Wiley & Sons, Ltd.

  17. Limited Antigenic Diversity in Contemporary H7 Avian-Origin Influenza A Viruses from North America

    Science.gov (United States)

    Xu, Yifei; Bailey, Elizabeth; Spackman, Erica; Li, Tao; Wang, Hui; Long, Li-Ping; Baroch, John A.; Cunningham, Fred L.; Lin, Xiaoxu; Jarman, Richard G.; DeLiberto, Thomas J.; Wan, Xiu-Feng

    2016-01-01

    Subtype H7 avian–origin influenza A viruses (AIVs) have caused at least 500 confirmed human infections since 2003 and culling of >75 million birds in recent years. Here we antigenically and genetically characterized 93 AIV isolates from North America (85 from migratory waterfowl [1976–2010], 7 from domestic poultry [1971–2012], and 1 from a seal [1980]). The hemagglutinin gene of these H7 viruses are separated from those from Eurasia. Gradual accumulation of nucleotide and amino acid substitutions was observed in the hemagglutinin of H7 AIVs from waterfowl and domestic poultry. Genotype characterization suggested that H7 AIVs in wild birds form diverse and transient internal gene constellations. Serologic analyses showed that the 93 isolates cross-reacted with each other to different extents. Antigenic cartography showed that the average antigenic distance among them was 1.14 units (standard deviation [SD], 0.57 unit) and that antigenic diversity among the H7 isolates we tested was limited. Our results suggest that the continuous genetic evolution has not led to significant antigenic diversity for H7 AIVs from North America. These findings add to our understanding of the natural history of IAVs and will inform public health decision-making regarding the threat these viruses pose to humans and poultry. PMID:26858078

  18. Photoperiodic Diapause and the Establishment of Aedes albopictus (Diptera: Culicidae) in North America

    Science.gov (United States)

    2016-01-01

    The invasion and range expansion of Aedes albopictus (Skuse) in North America represents an outstanding opportunity to study processes of invasion, range expansion, and climatic adaptation. Furthermore, knowledge obtained from such research is relevant to developing novel strategies to control this important vector species. Substantial evidence indicates that the photoperiodic diapause response is an important adaptation to climatic variation across the range of Ae. albopictus in North America. Photoperiodic diapause is a key determinant of abundance in both space and time, and the timing of entry into and exit out of diapause strongly affects seasonal population dynamics and thus the potential for arbovirus transmission. Emerging genomic technologies are making it possible to develop high-resolution, genome-wide genetic markers that can be used for genetic mapping of traits relevant to disease transmission and phylogeographic studies to elucidate invasion history. Recent work using next-generation sequencing technologies (e.g., RNA-seq), combined with physiological experiments, has provided extensive insight into the transcriptional basis of the diapause response in Ae. albopictus. Applying this knowledge to identify novel targets for vector control represents an important future challenge. Finally, recent studies have begun to identify traits other than diapause that are affected by photoperiodism. Extending this work to identify additional traits influenced by photoperiod should produce important insights into the seasonal biology of Ae. albopictus. PMID:27354438

  19. Dominant role of plant physiology in trend and variability of gross primary productivity in North America

    Science.gov (United States)

    Zhou, Sha; Zhang, Yao; Ciais, Philippe; Xiao, Xiangming; Luo, Yiqi; Caylor, Kelly K.; Huang, Yuefei; Wang, Guangqian

    2017-02-01

    Annual gross primary productivity (GPP) varies considerably due to climate-induced changes in plant phenology and physiology. However, the relative importance of plant phenology and physiology on annual GPP variation is not clear. In this study, a Statistical Model of Integrated Phenology and Physiology (SMIPP) was used to evaluate the relative contributions of maximum daily GPP (GPPmax) and the start and end of growing season (GSstart and GSend) to annual GPP variability, using a regional GPP product in North America during 2000-2014 and GPP data from 24 AmeriFlux sites. Climatic sensitivity of the three indicators was assessed to investigate the climate impacts on plant phenology and physiology. The SMIPP can explain 98% of inter-annual variability of GPP over mid- and high latitudes in North America. The long-term trend and inter-annual variability of GPP are dominated by GPPmax both at the ecosystem and regional scales. During warmer spring and autumn, GSstart is advanced and GSend delayed, respectively. GPPmax responds positively to summer temperature over high latitudes (40-80°N), but negatively in mid-latitudes (25-40°N). This study demonstrates that plant physiology, rather than phenology, plays a dominant role in annual GPP variability, indicating more attention should be paid to physiological change under futher climate change.

  20. Experience in North America Tight Oil Reserves Development. Horizontal Wells and Multistage Hydraulic Fracturing

    Directory of Open Access Journals (Sweden)

    R.R. Ibatullin

    2017-09-01

    Full Text Available The accelerated development of horizontal drilling technology in combination with the multistage hydraulic fracturing of the reservoir has expanded the geological conditions for commercial oil production from tight reservoirs in North America. Geological and physical characteristics of tight reservoirs in North America are presented, as well as a comparison of the geological and physical properties of the reservoirs of the Western Canadian Sedimentary Basin and the Volga-Ural oil and gas province, in particular, in the territory of Tatarstan. The similarity of these basins is shown in terms of formation and deposition. New drilling technologies for horizontal wells (HW and multistage hydraulic fracturing are considered. The drilling in tight reservoirs is carried out exclusively on hydrocarbon-based muds The multi-stage fracturing technology with the use of sliding sleeves, and also slick water – a low-viscous carrier for proppant is the most effective solution for conditions similar to tight reservoirs in the Devonian formation of Tatarstan. Tax incentives which are actively used for the development of HW and multistage fracturing technologies in Canada are described. wells, multistage fracturing

  1. The legal process of environmental evaluation and examination in North America and in the European Union

    International Nuclear Information System (INIS)

    Delpiano, V.

    1999-01-01

    The most important goal of the Environmental Law is to maximize the prevention approach. As so far, a scheme has been initiated since a few years to reach this objective: a legal environmental process with a lot of mechanisms whose the objective is to estimate the environmental impact of a project in order to control it. This legal environmental process including for example the Environmental Impact Assessment is more and more integrated in the environmental policies of the industrialized countries. It began in North America, first in the U.S.A. but also in Canada. A few years after, the countries of the Western Europe, particularly the European Unions, have introduced a similar legal process taking into account the specificities of these European countries. So if the goals of this legal environmental preventive approach are similar in North America and in Western Europe, the implementation is often different according to the legal, economic but also sociological structures of these two major regions. This Phd Thesis try to study the two major impacts of this legal evaluating process: it is implemented by the public authorities to reach with a best result a Sustainable Development. But also, it tries to combine the protection of the Environment and the utilisation of legal, economic and financial mechanisms of the Market to obtain a fair trade competition. (authors)

  2. The Arthroscopy Association of North America Advanced Arthroscopy Traveling Fellowship: A 10-Year History.

    Science.gov (United States)

    Mulcahey, Mary K; Waterman, Brian R

    2016-10-01

    In its brief 10-year existence, the Arthroscopy Association of North America Advanced Arthroscopy Traveling Fellowship has quickly established itself as the paramount educational experience for aspiring young surgeons in sports medicine and arthroscopy. The Traveling Fellowship is structured as a 10-day experience with visits to 3 host sites and culminates at the AANA Annual Meeting. With 4 selected fellows and an honorary "Godfather," the Traveling Fellowship affords a unique and invaluable opportunity to forge enduring friendships and rare mentorships with established leaders in the field of Arthroscopy. Potential applicants can anticipate not only developing their surgical acumen and aspects of clinical practice, but also assimilating key leadership skills, pearls on work-life balance, and a broader commitment to life-long education. The Dr. Don Johnson AANA Traveling Fellowship Alumni Group, named in honor of the two-time godfather and AANA Past President, represent an emerging class of leaders within AANA who are poised to contribute immensely to its mission of continuing medical education and collaboration. Copyright © 2016 Arthroscopy Association of North America. All rights reserved.

  3. Red brome (Bromus rubens subsp. madritensis) in North America: Possible modes for early introductions, subsequent spread

    Science.gov (United States)

    Salo, L.F.

    2005-01-01

    Although invasions by exotic plants have increased dramatically as human travel and commerce have increased, few have been comprehensively described. Understanding the patterns of invasive species spread over space and time will help guide management activities and policy. Tracing the earliest appearances of an exotic plant reveals likely sites of introduction, paving the way for genetic studies to quantify founder events and identify potential source populations. Red brome (Bromus madritensis subsp. rubens) is a Mediterranean winter annual grass that has invaded even relatively undisturbed areas of western North America, where it threatens native plant communities. This study used herbarium records and contemporary published accounts to trace the early introductions and subsequent spread of red brome in western North America. The results challenge the most frequently cited sources describing the early history of this grass and suggest three possible modes for early introductions: the California Gold Rush and Central Valley wheat, southern California shipping, and northern California sheep. Subsequent periods of most rapid spread into new areas, from 1930 to 1942, and of greatest spread into new regions, during the past 50 years, coincide with warm Pacific Decadal Oscillation regimes, which are linked to increased winter precipitation in the southwestern USA and northern Mexico. Global environmental change, including increased atmospheric CO2 levels and N deposition, may be contributing to the success of red brome, relative to native species.

  4. Post-Clovis survival of American Mastodon in the southern Great Lakes Region of North America

    Science.gov (United States)

    Woodman, N.; Beavan, Athfield N.

    2009-01-01

    The end of the Pleistocene in North America was marked by a wave of extinctions of large mammals, with the last known appearances of many species falling between ca. 11,000-10,000??14C yr BP. Temporally, this period overlaps with the Clovis Paleoindian cultural complex (11,190-10,530??14C yr BP) and with sudden climatic changes that define the beginning of the Younger Dryas chronozone (ca. 11,000-10,000??14C yr BP), both of which have been considered as potential proximal causes of this extinction event. Radiocarbon dating of enamel and filtered bone collagen from an extinct American Mastodon (Mammut americanum) from northern Indiana, USA, by accelerator mass spectrometer yielded direct dates of 10,055 ?? 40??14C yr BP and 10,032 ?? 40??14C yr BP, indicating that the animal survived beyond the Clovis time period and into the late Younger Dryas. Although the late survival of this species in mid-continental North America does not remove either humans or climatic change as contributing causes for the late Pleistocene extinctions, neither Clovis hunters nor the climatic perturbations initiating the Younger Dryas chronozone were immediately responsible for driving mastodons to extinction. ?? 2009 University of Washington.

  5. Post-Clovis survival of American Mastodon in the southern Great Lakes Region of North America

    Science.gov (United States)

    Woodman, Neal; Beavan Athfield, Nancy

    2009-11-01

    The end of the Pleistocene in North America was marked by a wave of extinctions of large mammals, with the last known appearances of many species falling between ca. 11,000-10,000 14C yr BP. Temporally, this period overlaps with the Clovis Paleoindian cultural complex (11,190-10,530 14C yr BP) and with sudden climatic changes that define the beginning of the Younger Dryas chronozone (ca. 11,000-10,000 14C yr BP), both of which have been considered as potential proximal causes of this extinction event. Radiocarbon dating of enamel and filtered bone collagen from an extinct American Mastodon ( Mammut americanum) from northern Indiana, USA, by accelerator mass spectrometer yielded direct dates of 10,055 ± 40 14C yr BP and 10,032 ± 40 14C yr BP, indicating that the animal survived beyond the Clovis time period and into the late Younger Dryas. Although the late survival of this species in mid-continental North America does not remove either humans or climatic change as contributing causes for the late Pleistocene extinctions, neither Clovis hunters nor the climatic perturbations initiating the Younger Dryas chronozone were immediately responsible for driving mastodons to extinction.

  6. A proposed lexicon of terms and concepts for human-bear management in North America

    Science.gov (United States)

    Hopkins, John B.; Herrero, Stephen; Shideler, Richard T.; Gunther, Kerry A.; Schwartz, Charles C.; Kalinowski, Steven T.

    2010-01-01

    We believe that communication within and among agency personnel in the United States and Canada about the successes and failures of their human–bear (Ursidae) management programs will increase the effectiveness of these programs and of bear research. To communicate more effectively, we suggest agencies clearly define terms and concepts used in human–bear management and use them in a consistent manner. We constructed a human–bear management lexicon of terms and concepts using a modified Delphi method to provide a resource that facilitates more effective communication among human–bear management agencies. Specifically, we defined 40 terms and concepts in human–bear management and suggest definitions based on discussions with 13 other professionals from the United States and Canada. Although new terms and concepts will emerge in the future and definitions will evolve as we learn more about bear behavior and ecology, our purpose is to suggest working definitions for terms and concepts to help guide human–bear management and research activities in North America. Applications or revisions of these definitions may be useful outside of North America.

  7. Tracking multi-generational colonization of the breeding grounds by monarch butterflies in eastern North America

    Science.gov (United States)

    Flockhart, D. T. Tyler; Wassenaar, Leonard I.; Martin, Tara G.; Hobson, Keith A.; Wunder, Michael B.; Norris, D. Ryan

    2013-01-01

    Insect migration may involve movements over multiple breeding generations at continental scales, resulting in formidable challenges to their conservation and management. Using distribution models generated from citizen scientist occurrence data and stable-carbon and -hydrogen isotope measurements, we tracked multi-generational colonization of the breeding grounds of monarch butterflies (Danaus plexippus) in eastern North America. We found that monarch breeding occurrence was best modelled with geographical and climatic variables resulting in an annual breeding distribution of greater than 12 million km2 that encompassed 99% occurrence probability. Combining occurrence models with stable isotope measurements to estimate natal origin, we show that butterflies which overwintered in Mexico came from a wide breeding distribution, including southern portions of the range. There was a clear northward progression of monarchs over successive generations from May until August when reproductive butterflies began to change direction and moved south. Fifth-generation individuals breeding in Texas in the late summer/autumn tended to originate from northern breeding areas rather than regions further south. Although the Midwest was the most productive area during the breeding season, monarchs that re-colonized the Midwest were produced largely in Texas, suggesting that conserving breeding habitat in the Midwest alone is insufficient to ensure long-term persistence of the monarch butterfly population in eastern North America. PMID:23926146

  8. Significantly Increased Extreme Precipitation Expected in Europe and North America from Extratropical Storms

    Science.gov (United States)

    Hawcroft, M.; Hodges, K.; Walsh, E.; Zappa, G.

    2017-12-01

    For the Northern Hemisphere extratropics, changes in circulation are key to determining the impacts of climate warming. The mechanisms governing these circulation changes are complex, leading to the well documented uncertainty in projections of the future location of the mid-latitude storm tracks simulated by climate models. These storms are the primary source of precipitation for North America and Europe and generate many of the large-scale precipitation extremes associated with flooding and severe economic loss. Here, we show that in spite of the uncertainty in circulation changes, by analysing the behaviour of the storms themselves, we find entirely consistent and robust projections across an ensemble of climate models. In particular, we find that projections of change in the most intensely precipitating storms (above the present day 99th percentile) in the Northern Hemisphere are substantial and consistent across models, with large increases in the frequency of both summer (June-August, +226±68%) and winter (December-February, +186±34%) extreme storms by the end of the century. Regionally, both North America (summer +202±129%, winter +232±135%) and Europe (summer +390±148%, winter +318±114%) are projected to experience large increases in the frequency of intensely precipitating storms. These changes are thermodynamic and driven by surface warming, rather than by changes in the dynamical behaviour of the storms. Such changes in storm behaviour have the potential to have major impacts on society given intensely precipitating storms are responsible for many large-scale flooding events.

  9. Hydrologic effects of land and water management in North America and Asia: 1700–1992

    Directory of Open Access Journals (Sweden)

    I. Haddeland

    2007-01-01

    Full Text Available The hydrologic effects of land use changes, dams, and irrigation in North America and Asia over the past 300 years are studied using a macroscale hydrologic model. The simulation results indicate that the expansion of croplands over the last three centuries has resulted in 2.5 and 6 percent increases in annual runoff volumes for North America and Asia, respectively, and that these increases in runoff to some extent have been compensated by increased evapotranspiration caused by irrigation practices. Averaged over the year and the continental scale, the accumulated anthropogenic impacts on surface water fluxes are hence relatively minor. However, for some regions within the continents human activities have altered hydrologic regimes profoundly. Reservoir operations and irrigation practices in the western part of USA and Mexico have resulted in a 25 percent decrease in runoff in June, and a 9 percent decrease in annual runoff volumes reaching the Pacific Ocean. In the area in South East Asia draining to the Pacific Ocean, land use changes have caused an increase in runoff volumes throughout the year, and the average annual increase in runoff is 12 percent.

  10. The European lesser glow worm, Phosphaenus hemipterus (Goeze, in North America (Coleoptera, Lampyridae

    Directory of Open Access Journals (Sweden)

    Christopher Majka

    2009-12-01

    Full Text Available Phosphaenus hemipterus (Goeze is a Palaearctic glow worm (Coleoptera: Lampyridae, previously been reported in North America on the basis of two specimens; one collected in 1947 in Yarmouth, Nova Scotia; the other in 1989 in Montreal, Quebec. The present study newly records it from three sites in Halifax, Nova Scotia. One hundred and twenty six adult males and larvae were collected in 2009 in disturbed urban grassland areas, similar to habitats in England and Belgium where the species has been investigated. Experiments confirm that larvae feed on earthworms (Lumbricus terrestris, consistent with observations in Europe. The habitat is described, including vegetation, potential predators, and prey. Although ballast-shipments have previously been proposed as a vector for the species’ introduction to North America, the present study suggests that the importation of agricultural and horticultural products, which has lead to the introduction of many earthworms to the continent, could also serve as a conduit for the introduction of obligate earthworm predators such as the larvae of P. hemipterus. Although an adventive species, possible conservation concerns are discussed for a species that is considered endangered in parts of its native range.

  11. A revision of the spider genus Selenops Latreille, 1819 (Arachnida, Araneae, Selenopidae) in North America, Central America and the Caribbean.

    Science.gov (United States)

    Crews, Sarah C

    2011-01-01

    The spider genus Selenops Latreille, 1819 occurs in both the Old World and New World tropics and subtropics and contains nearly half of the species in the family Selenopidae Simon, 1897. In this paper the members of the genus Selenops found in North America, Central America, and on islands of the Caribbean are revised, excluding Cuban endemics. No taxonomic changes are currently made to the species from the southwestern United States. In total, 21 new species are described, including Selenops arikoksp. n., Selenops chamelasp. n., Selenops amonasp. n., Selenops bawekasp. n., Selenops bocacanadensissp. n., Selenops enriquillosp. n, Selenops ixchelsp. n., Selenops huetocatlsp. n., Selenops kalinagosp. n., Selenops oviedosp. n., Selenops morrosp. n., Selenops deniasp. n., Selenops duansp. n., Selenops malinalxochitlsp. n., Selenops oricuajosp. n., Selenops petenajtoysp. n., Selenops guerrerosp. n., Selenops makimakisp. n., Selenops souligasp. n., Selenops wilmotorumsp. n., and Selenops wilsonisp. n. Six species names were synonymized: Selenops lunatus Muma, 1953 syn. n. =Selenops candidus Muma, 1953; Selenops tehuacanus Muma 1953 syn. n., Selenops galapagoensis Banks, 1902 syn. n. and Selenops vagabundus Kraus, 1955 syn. n. = Selenops mexicanus Keyserling, 1880; Selenops santibanezi Valdez-Mondragón, 2010 syn. n. = Selenops nigromaculatus Keyserling, 1880; and Selenops salvadoranus Chamberlin, 1925 syn. n. = Selenops bifurcatus Banks, 1909. Lectotypes are designated for the following three species: Selenops marginalis F. O. Pickard-Cambridge, 1900 (♂), Selenops morosus Banks, 1898 (♂), and Selenops mexicanus Keyserling, 1880 (♀). The female neotype is designated for Selenops aissus Walckenaer, 1837. The males of Selenops bani Alayón-García, 1992 and Selenops marcanoi Alayón-García, 1992 are described for the first time, and the females of Selenops phaselus Muma, 1953 and Selenops geraldinae Corronca, 1996 are described for the first time. Almost all species

  12. Greater post-Neolithic wealth disparities in Eurasia than in North America and Mesoamerica.

    Science.gov (United States)

    Kohler, Timothy A; Smith, Michael E; Bogaard, Amy; Feinman, Gary M; Peterson, Christian E; Betzenhauser, Alleen; Pailes, Matthew; Stone, Elizabeth C; Marie Prentiss, Anna; Dennehy, Timothy J; Ellyson, Laura J; Nicholas, Linda M; Faulseit, Ronald K; Styring, Amy; Whitlam, Jade; Fochesato, Mattia; Foor, Thomas A; Bowles, Samuel

    2017-11-30

    How wealth is distributed among households provides insight into the fundamental characters of societies and the opportunities they afford for social mobility. However, economic inequality has been hard to study in ancient societies for which we do not have written records, which adds to the challenge of placing current wealth disparities into a long-term perspective. Although various archaeological proxies for wealth, such as burial goods or exotic or expensive-to-manufacture goods in household assemblages, have been proposed, the first is not clearly connected with households, and the second is confounded by abandonment mode and other factors. As a result, numerous questions remain concerning the growth of wealth disparities, including their connection to the development of domesticated plants and animals and to increases in sociopolitical scale. Here we show that wealth disparities generally increased with the domestication of plants and animals and with increased sociopolitical scale, using Gini coefficients computed over the single consistent proxy of house-size distributions. However, unexpected differences in the responses of societies to these factors in North America and Mesoamerica, and in Eurasia, became evident after the end of the Neolithic period. We argue that the generally higher wealth disparities identified in post-Neolithic Eurasia were initially due to the greater availability of large mammals that could be domesticated, because they allowed more profitable agricultural extensification, and also eventually led to the development of a mounted warrior elite able to expand polities (political units that cohere via identity, ability to mobilize resources, or governance) to sizes that were not possible in North America and Mesoamerica before the arrival of Europeans. We anticipate that this analysis will stimulate other work to enlarge this sample to include societies in South America, Africa, South Asia and Oceania that were under-sampled or not

  13. The role of tropical cyclones in precipitation over the tropical and subtropical North America

    Science.gov (United States)

    Dominguez, Christian; Magaña, Victor

    2018-03-01

    Tropical cyclones (TCs) are essential elements of the hydrological cycle in tropical and subtropical regions. In the present study, the contribution of TCs to seasonal precipitation around the tropical and subtropical North America is examined. When TC activity over the tropical eastern Pacific (TEP) or the Intra Americas Seas (IAS) is below (above-normal), regional precipitation may be below (above-normal). However, it is not only the number of TCs what may change seasonal precipitation, but the trajectory of the systems. TCs induce intense precipitation over continental regions if they are close enough to shorelines, for instance, if the TC center is located, on average, less than 500 km-distant from the coast. However, if TCs are more remote than this threshold distance, the chances of rain over continental regions decrease, particularly in arid and semi-arid regions. In addition, a distant TC may induce subsidence or produce moisture divergence that inhibits, at least for a few days, convective activity farther away than the threshold distance. An analysis of interannual variability in the TCs that produce precipitation over the tropical and subtropical North America shows that some regions in northern Mexico, which mostly depend on this effect to undergo wet years, may experience seasonal negative anomalies in precipitation if TCs trajectories are remote. Therefore, TCs (activity and trajectories) are important modulators of climate variability on various time scales, either by producing intense rainfall or by inhibiting convection at distant regions from their trajectory. The impact of such variations on water availability in northern Mexico may be relevant, since water availability in dams recovers under the effects of TC rainfall. Seasonal precipitation forecasts or climate change scenarios for these regions should take into account the effect of TCs, if regional adaptation strategies are implemented.

  14. Future inhibition of ecosystem productivity by increasing wildfire pollution over boreal North America

    Directory of Open Access Journals (Sweden)

    X. Yue

    2017-11-01

    Full Text Available Biomass burning is an important source of tropospheric ozone (O3 and aerosols. These air pollutants can affect vegetation photosynthesis through stomatal uptake (for O3 and light scattering and absorption (for aerosols. Wildfire area burned is projected to increase significantly in boreal North America by the mid-century, while little is known about the impacts of enhanced emissions on the terrestrial carbon budget. Here, combining site-level and satellite observations and a carbon–chemistry–climate model, we estimate the impacts of fire emitted O3 and aerosols on net primary productivity (NPP over boreal North America. Fire emissions are calculated based on an ensemble projection from 13 climate models. In the present day, wildfire enhances surface O3 by 2 ppbv (7 % and aerosol optical depth (AOD at 550 nm by 0.03 (26 % in the summer. By mid-century, area burned is predicted to increase by 66 % in boreal North America, contributing more O3 (13 % and aerosols (37 %. Fire O3 causes negligible impacts on NPP because ambient O3 concentration (with fire contributions is below the damage threshold of 40 ppbv for 90 % summer days. Fire aerosols reduce surface solar radiation but enhance atmospheric absorption, resulting in enhanced air stability and intensified regional drought. The domain of this drying is confined to the north in the present day but extends southward by 2050 due to increased fire emissions. Consequently, wildfire aerosols enhance NPP by 72 Tg C yr−1 in the present day but decrease NPP by 118 Tg C yr−1 in the future, mainly because of the soil moisture perturbations. Our results suggest that future wildfire may accelerate boreal carbon loss, not only through direct emissions increasing from 68 Tg C yr−1 at present day to 130 Tg C yr−1 by mid-century but also through the biophysical impacts of fire aerosols.

  15. Are diamond-bearing Cretaceous kimberlites related to shallow-angle subduction beneath western North America?

    Science.gov (United States)

    Currie, C. A.; Beaumont, C.

    2009-05-01

    The origin of deep-seated magmatism (in particular, kimberlites and lamproites) within continental plate interiors remains enigmatic in the context of plate tectonic theory. One hypothesis proposes a relationship between kimberlite occurrence and lithospheric subduction, such that a subducting plate releases fluids below a continental craton, triggering melting of the deep lithosphere and magmatism (Sharp, 1974; McCandless, 1999). This study provides a quantitative evaluation of this hypothesis, focusing on the Late Cretaceous- Eocene (105-50 Ma) kimberlites and lamproites of western North America. These magmas were emplaced along a corridor of Archean and Proterozoic lithosphere, 1000-1500 km inboard of the plate margin separating the subducting Farallon Plate and continental North America Plate. Kimberlite-lamproite magmatism coincides with tectonic events, including the Laramide orogeny, shut-down of the Sierra Nevada arc, and eastward migration of volcanism, that are commonly attributed to a change in Farallon Plate geometry to a shallow-angle trajectory (subduction that places the Farallon Plate beneath the western edge of the cratonic interior of North America. This geometry is consistent with the observed continental dynamic subsidence that lead to the development of the Western Interior Seaway. The models also show that the subducting plate has a cool thermal structure, and subducted hydrous minerals (serpentine, phengite and phlogopite) remain stable to more than 1200 km from the trench, where they may break down and release fluids that infiltrate the overlying craton lithosphere. This is supported by geochemical studies that indicate metasomatism of the Colorado Plateau and Wyoming craton mantle lithosphere by an aqueous fluid and/or silicate melt with a subduction signature. Through Cretaceous shallow-angle subduction, the Farallon Plate was in a position to mechanically and chemically interact with North American craton lithosphere at the time of

  16. North America's net terrestrial CO2 exchange with the atmosphere 1990-2009

    Science.gov (United States)

    King, A. W.; Andres, R. J.; Davis, K. J.; Hafer, M.; Hayes, D. J.; Huntzinger, D. N.; de Jong, B.; Kurz, W. A.; McGuire, A. D.; Vargas, R.; Wei, Y.; West, T. O.; Woodall, C. W.

    2015-01-01

    Scientific understanding of the global carbon cycle is required for developing national and international policy to mitigate fossil fuel CO2 emissions by managing terrestrial carbon uptake. Toward that understanding and as a contribution to the REgional Carbon Cycle Assessment and Processes (RECCAP) project, this paper provides a synthesis of net land-atmosphere CO2 exchange for North America (Canada, United States, and Mexico) over the period 1990-2009. Only CO2 is considered, not methane or other greenhouse gases. This synthesis is based on results from three different methods: atmospheric inversion, inventory-based methods and terrestrial biosphere modeling. All methods indicate that the North American land surface was a sink for atmospheric CO2, with a net transfer from atmosphere to land. Estimates ranged from -890 to -280 Tg C yr-1, where the mean of atmospheric inversion estimates forms the lower bound of that range (a larger land sink) and the inventory-based estimate using the production approach the upper (a smaller land sink). This relatively large range is due in part to differences in how the approaches represent trade, fire and other disturbances and which ecosystems they include. Integrating across estimates, "best" estimates (i.e., measures of central tendency) are -472 ± 281 Tg C yr-1 based on the mean and standard deviation of the distribution and -360 Tg C yr-1 (with an interquartile range of -496 to -337) based on the median. Considering both the fossil fuel emissions source and the land sink, our analysis shows that North America was, however, a net contributor to the growth of CO2 in the atmosphere in the late 20th and early 21st century. With North America's mean annual fossil fuel CO2 emissions for the period 1990-2009 equal to 1720 Tg C yr-1 and assuming the estimate of -472 Tg C yr-1 as an approximation of the true terrestrial CO2 sink, the continent's source : sink ratio for this time period was 1720:472, or nearly 4:1.

  17. North America's net terrestrial CO2 exchange with the atmosphere 1990–2009

    Science.gov (United States)

    King, A.W.; Andres, R.J.; Davis, K.J.; Hafer, M.; Hayes, D.J.; Huntzinger, Deborah N.; de Jong, Bernardus; Kurz, W.A.; McGuire, A. David; Vargas, Rodrigo I.; Wei, Y.; West, Tristram O.; Woodall, Christopher W.

    2015-01-01

    Scientific understanding of the global carbon cycle is required for developing national and international policy to mitigate fossil fuel CO2 emissions by managing terrestrial carbon uptake. Toward that understanding and as a contribution to the REgional Carbon Cycle Assessment and Processes (RECCAP) project, this paper provides a synthesis of net land–atmosphere CO2 exchange for North America (Canada, United States, and Mexico) over the period 1990–2009. Only CO2 is considered, not methane or other greenhouse gases. This synthesis is based on results from three different methods: atmospheric inversion, inventory-based methods and terrestrial biosphere modeling. All methods indicate that the North American land surface was a sink for atmospheric CO2, with a net transfer from atmosphere to land. Estimates ranged from −890 to −280 Tg C yr−1, where the mean of atmospheric inversion estimates forms the lower bound of that range (a larger land sink) and the inventory-based estimate using the production approach the upper (a smaller land sink). This relatively large range is due in part to differences in how the approaches represent trade, fire and other disturbances and which ecosystems they include. Integrating across estimates, "best" estimates (i.e., measures of central tendency) are −472 ± 281 Tg C yr−1 based on the mean and standard deviation of the distribution and −360 Tg C yr−1 (with an interquartile range of −496 to −337) based on the median. Considering both the fossil fuel emissions source and the land sink, our analysis shows that North America was, however, a net contributor to the growth of CO2 in the atmosphere in the late 20th and early 21st century. With North America's mean annual fossil fuel CO2 emissions for the period 1990–2009 equal to 1720 Tg C yr−1 and assuming the estimate of −472 Tg C yr−1 as an approximation of the true terrestrial CO2 sink, the continent's source : sink ratio for this time period was

  18. Vertical slab sinking and westward subduction offshore of Mesozoic North America

    Science.gov (United States)

    Sigloch, Karin; Mihalynuk, Mitchell G.

    2013-04-01

    Subducted slabs in the mantle, as imaged by seismic tomography, preserve a record of ancient subduction zones. Ongoing debate concerns how direct this link is. How long ago did each parcel of slab subduct, and where was the trench located relative to the imaged slab position? Resolving these questions will benefit paleogeographic reconstructions, and restrict the range of plausible rheologies for mantle convection simulations. We investigate one of the largest and best-constrained Mesozoic slab complexes, the "Farallon" in the transition zone and lower mantle beneath North America. We quantitatively integrate observations from whole-mantle P-wave tomography, global plate reconstructions, and land geological evidence from the North American Cordillera. These three data sets permit us to test the simplest conceivable hypothesis for linking slabs to paleo-trenches: that each parcel of slab sank only vertically shortly after entering the trench That is, we test whether within the limits of tomographic resolution, all slab material lies directly below the location where it subducted beneath its corresponding arc. Crucially and in contrast to previous studies, we do not accept or impose an Andean-style west coast trench (Farallon-beneath-continent subduction) since Jurassic times, as this scenario is inconsistent with many geological observations. Slab geometry alone suggests that trenches started out as intra-oceanic because tomography images massive, linear slab "walls" in the lower mantle, extending almost vertically from about 800 km to 2000+ km depth. Such steep geometries would be expected from slabs sinking vertically beneath trenches that were quasi-stationary over many tens of millions of years. Intra-oceanic trenches west of Mesozoic North America could have been stationary, whereas a coastal Farallon trench could not, because the continent moved westward continuously as the Atlantic opened. Overlap of North American west-coast positions, as reconstructed in a

  19. The influence of boreal biomass burning emissions on the distribution of tropospheric ozone over North America and the North Atlantic during 2010

    OpenAIRE

    M. Parrington; P. I. Palmer; D. K. Henze; D. W. Tarasick; E. J. Hyer; R. C. Owen; D. Helmig; C. Clerbaux; K. W. Bowman; M. N. Deeter; E. M. Barratt; P.-F. Coheur; D. Hurtmans; M. George; J. R. Worden

    2011-01-01

    We analyse the tropospheric ozone distribution over North America and the North Atlantic to boreal biomass burning emissions during the summer of 2010 using the GEOS-Chem 3-D global tropospheric chemical transport model, and observations from in situ and satellite instruments. In comparison to observations from the PICO-NARE observatory in the Azores, ozonesondes across Canada, and the Tropospheric Emission Spectrometer (TES) and Infrared Atmospheric Sounding Instrument (IASI) satellite instr...

  20. Future inhibition of ecosystem productivity by increasing wildfire pollution over boreal North America

    Science.gov (United States)

    Yue, X.; Strada, S.; Unger, N.

    2017-12-01

    Biomass burning is an important source of tropospheric ozone (O3) and aerosols, which can affect vegetation photosynthesis through stomatal uptake (for O3) and light scattering and meteorological variations (for aerosols). Climate change will significantly increase wildfire activity in boreal North America by the midcentury, while little is known about the impacts of enhanced emissions on the terrestrial carbon budget. Here, combining site-level and satellite observations and a carbon-chemistry-climate model, we estimate the impacts of fire emitted O3 and aerosols on net primary productivity (NPP) over boreal North America. Fire emissions are calculated based on an ensemble projection from 13 climate models. In the present day, wildfire enhances surface O3 by 2 ppbv (7%) and aerosol optical depth (AOD) at 550 nm by 0.03 (26%) in the summer. By midcentury, boreal area burned is predicted to increase by 66%, contributing more O3 (13%) and aerosols (37%). Fire O3 causes negligible impacts on NPP because ambient O3 concentration is far below the damaging thresholds. Fire aerosols reduce surface solar radiation but enhance atmospheric absorption, resulting in enhanced air stability and intensified regional drought. The domain of this drying is confined to the North in the present day, but extends southward by 2050 due to increased fire emissions. Consequently, wildfire aerosols enhance NPP by 72 Tg C yr-1 in the present day but decrease NPP by 118 Tg C yr-1 in the future, mainly because of the soil moisture perturbations. Our results suggest that future wildfire may accelerate boreal carbon loss, not only through direct emissions, but also through the biophysical impacts of fire aerosols.

  1. Ancient mitochondrial DNA reveals convergent evolution of giant short-faced bears (Tremarctinae) in North and South America

    OpenAIRE

    Mitchell, Kieren J.; Bray, Sarah C.; Bover, Pere; Soibelzon, Leopoldo; Schubert, Blaine W.; Prevosti, Francisco; Prieto, Alfredo; Martin, Fabiana; Austin, Jeremy J.; Cooper, Alan

    2016-01-01

    The Tremarctinae are a subfamily of bears endemic to the New World, including two of the largest terrestrial mammalian carnivores that have ever lived: the giant, short-faced bears Arctodus simus from North America and Arctotherium angustidens from South America (greater than or equal to 1000 kg). Arctotherium angustidens became extinct during the Early Pleistocene, whereas Arctodus simus went extinct at the very end of the Pleistocene. The only living tremarctine is the spectacled bear (Trem...

  2. Increasing ozone in marine boundary layer inflow at the west coasts of North America and Europe

    Directory of Open Access Journals (Sweden)

    D. D. Parrish

    2009-02-01

    Full Text Available An effective method is presented for determining the ozone (O3 mixing ratio in the onshore flow of marine air at the North American west coast. By combining the data available from all marine boundary layer (MBL sites with simultaneous wind data, decadal temporal trends of MBL O3 in all seasons are established with high precision. The average springtime temporal trend over the past two decades is 0.46 ppbv/yr with a 95% confidence limit of 0.13 ppbv/yr, and statistically significant trends are found for all seasons except autumn, which does have a significantly smaller trend than other seasons. The average trend in mean annual ozone is 0.34±0.09 ppbv/yr. These decadal trends at the North American west coast present a striking comparison and contrast with the trends reported for the European west coast at Mace Head, Ireland. The trends in the winter, spring and summer seasons compare well at the two locations, while the Mace Head trend is significantly greater in autumn. Even though the trends are similar, the absolute O3 mixing ratios differ markedly, with the marine air arriving at Europe in all seasons containing 7±2 ppbv higher ozone than marine air arriving at North America. Further, the ozone mixing ratios at the North American west coast show no indication of stabilizing as has been reported for Mace Head. In a larger historical context the background boundary layer O3 mixing ratios over the 130 years covered by available data have increased substantially (by a factor of two to three, and this increase continues at present, at least in the MBL of the Pacific coast region of North America. The reproduction of the increasing trends in MBL O3 over the past two decades, as well as the difference in the O3 mixing ratios between the two coastal regions will present a significant challenge for global chemical transport models. Further, the ability of the models to at least semi

  3. Low prevalence of Trichomonas gallinae in urban and migratory Cooper's Hawks in northcentral North America

    Science.gov (United States)

    Rosenfield, Robert N.; Taft, Stephen J.; Stout, William E.; Driscoll, Timothy G.; Evans, David L.; Bozek, Michael A.

    2009-01-01

    Trichomoniasis is a digestive tract disease caused by ingestion of the protozoan Trichomonas gallinae. This disease can be a significant source of mortality. No deaths of nestlings could be attributed to trichomoniasis in Cooper's Hawks (Accipiter cooperii) breeding in urban and rural environs in Wisconsin, North Dakota, and British Columbia. We detected T. gallinae in four (5.2%) of 77 nestling Cooper's Hawks during 2006 and 2007 among 42 urban nests on new study areas in southeast Wisconsin and eastern North Dakota/western Minnesota. All four infected young fledged. We did not detect T. gallinae in 52 breeding adult Cooper's Hawks on two urban study sites, nor in 28 migrant hatching year (n  =  24) and adult (n  =  4) Cooper's Hawks at Hawk Ridge Nature Reserve, Duluth, Minnesota in 2006–2007. Overall, we detected T. gallinae in only 2.5% of 157 Cooper's Hawks in northcentral North America. These results suggest a low prevalence of T. gallinae in Cooper's Hawks in the northern part of this hawk's breeding range.

  4. Phylogeny of Cirsium spp. in North America: Host Specificity Does Not Follow Phylogeny

    Directory of Open Access Journals (Sweden)

    Tracey A. Bodo Slotta

    2012-10-01

    Full Text Available Weedy invasive Cirsium spp. are widespread in temperate regions of North America and some of their biological control agents have attacked native Cirsium spp. A phylogenetic tree was developed from DNA sequences for the internal transcribed spacer and external transcribed spacer regions from native and non-native Great Plains Cirsium spp. and other thistles to determine if host specificity follows phylogeny. The monophyly of Cirsium spp. and Carduus within the tribe Cardinae was confirmed with native North American and European lineages of the Cirsium spp. examined. We did not detect interspecific hybridization between the introduced invasive and the native North American Cirsium spp. Selected host-biological control agent interactions were mapped onto the phylogenic tree derived by maximum likelihood analysis to examine the co-occurrence of known hosts with biological control agents. Within Cirsium-Cardueae, the insect biological control agents do not associate with host phylogenetic lines. Thus, more comprehensive testing of species in host-specificity trials, rather than relying on a single representative of a given clade may be necessary; because the assumption that host-specificity follows phylogeny does not necessarily hold. Since the assumption does not always hold, it will also be important to evaluate ecological factors to provide better cues for host specificity.

  5. Comparative biology of zebra mussels in Europe and North America: an overview

    Science.gov (United States)

    Mackie, Gerald L.; Schloesser, Don W.

    1996-01-01

    SYNOPSIS. Since the discovery of the zebra mussel, Dreissena polymorpha, in the Great Lakes in 1988 comparisons have been made with mussel populations in Europe and the former Soviet Union. These comparisons include: Population dynamics, growth and mortality rates, ecological tolerances and requirements, dispersal rates and patterns, and ecological impacts. North American studies, mostly on the zebra mussel and a few on a second introduced species, the quagga mussel, Dreissena bugensis, have revealed some similarities and some differences. To date it appears that North American populations of zebra mussels are similar to European populations in their basic biological characteristics, population growth and mortality rates, and dispersal mechanisms and rates. Relative to European populations differences have been demonstrated for: (1) individual growth rates; (2) life spans; (3) calcium and pH tolerances and requirements; (4) potential distribution limits; and (5) population densities of veligers and adults. In addition, studies on the occurrence of the two dreissenid species in the Great Lakes are showing differences in their modes of life, depth distributions, and growth rates. As both species spread throughout North America, comparisons between species and waterbodies will enhance our ability to more effectively control these troublesome species.

  6. Population dynamics and evolutionary history of the weedy vine Ipomoea hederacea in North America.

    Science.gov (United States)

    Campitelli, Brandon E; Stinchcombe, John R

    2014-06-03

    Disentangling the historical evolutionary processes that contribute to patterns of phenotypic and genetic variation is important for understanding contemporary patterns of both traits of interest and genetic diversity of a species. Ipomoea hederacea is a self-compatible species whose geographic origin is contested, and previous work suggests that although there are signals of adaptation (significant leaf shape and flowering time clines), no population structure or neutral genetic differentiation of I. hederacea populations was detected. Here, we use DNA sequence data to characterize patterns of genetic variation to establish a more detailed understanding of the current and historical processes that may have generated the patterns of genetic variation in this species. We resequenced ca. 5000 bp across 7 genes for 192 individuals taken from 24 populations in North America. Our results indicate that North American I. hederacea populations are ubiquitously genetically depauperate, and patterns of nucleotide diversity are consistent with population expansion. Contrary to previous findings, we discovered significant population subdivision and isolation-by-distance, but genetic structure was spatially discontinuous, potentially implicating long-distance dispersal. We further found significant genetic differentiation at sequenced loci but nearly fourfold stronger differentiation at the leaf shape locus, strengthening evidence that the leaf shape locus is under divergent selection. We propose that North American I. hederacea has experienced a recent founder event, and/or population dynamics are best described by a metapopulation model (high turnover and dispersal), leading to low genetic diversity and a patchy genetic distribution. Copyright © 2014 Campitelli and Stinchcombe.

  7. Climate-driven trends in the occurrence of major floods across North America and Europe

    Science.gov (United States)

    Hodgkins, Glenn A.; Whitfield, Paul H.; Burn, Donald H.; Hannaford, Jamie; Renard, Benjamin; Stahl, Kerstin; Fleig, Anne K.; Madsen, Henrik; Mediero, Luis; Korhonen, Johanna; Murphy, Conor; Crochet, Philippe; Wilson, Donna

    2016-04-01

    Every year river floods cause enormous damage around the world. Recent major floods in North America and Europe, for example, have received much press, with some concluding that these floods are more frequent in recent years as a result of anthropogenic warming. There has been considerable scientific effort invested in establishing whether observed flood records show evidence of trends or variability in flood frequency, and to determine whether these patterns can be linked to climatic changes. However, the river catchments used in many published studies are influenced by direct human alteration such as reservoir regulation and urbanisation, which can confound the interpretation of climate-driven variability. Furthermore, a majority of previous studies have analysed changes in low magnitude floods, such as the annual peak flow, at a national scale. Few studies are known that have analysed changes in large floods (greater than 25-year floods) on a continental scale. To fill this research gap, we present a study analysing flood flows from reference hydrologic networks (RHNs) or RHN-like gauges across a large study domain embracing North America and much of Europe. RHNs comprise gauging stations with minimally disturbed catchment conditions, which have a near-natural flow regime and provide good quality data; RHN analyses thus allow hydro-climatic variability to be distinguished from direct artificial disturbances or data inhomogeneities. One of the key innovations in this study is the definition of an RHN-like network consisting of 1204 catchments on a continental scale. The network incorporates existing, well-established RHNs in Canada, the US, the UK, Ireland and Norway, alongside RHN-like catchments from Europe (France, Switzerland, Iceland, Denmark, Sweden, Finland, Spain), which have been incorporated in the network following a major effort to ensure RHN-like status of candidate gauges through consultation with local experts. As the aim of the study is to examine

  8. The Cambrian-Ordovician rocks of Sonora, Mexico, and southern Arizona, southwestern margin of North America (Laurentia): chapter 35

    Science.gov (United States)

    Page, William R.; Harris, Alta C.; Repetski, John E.; Derby, James R.; Fritz, R.D.; Longacre, S.A.; Morgan, W.A.; Sternbach, C.A.

    2013-01-01

    Cambrian and Ordovician shelf, platform, and basin rocks are present in Sonora, Mexico, and southern Arizona and were deposited on the southwestern continental margin of North America (Laurentia). Cambrian and Ordovician rocks in Sonora, Mexico, are mostly exposed in scattered outcrops in the northern half of the state. Their discontinuous nature results from extensive Quaternary and Tertiary surficial cover, from Tertiary and Mesozoic granitic batholiths in western Sonora, and from widespread Tertiary volcanic deposits in the Sierra Madre Occidental in eastern Sonora. Cambrian and Ordovician shelf rocks were deposited as part of the the southern miogeocline on the southwestern continental margin of North America.

  9. Homogeneous SLOWPOKE reactors for Mo-99/Tc-99m production in North America

    Energy Technology Data Exchange (ETDEWEB)

    Hilborn, J.W., E-mail: hilbovanw@sympatico.ca [Deep River, Ontario (Canada); Bonin, H.W. [Royal Military College of Canada, Kingston, Ontario (Canada)

    2014-07-01

    The 15 month shutdown of NRU in 2009 - 2010 caused an overall isotope shortage of approximately 30%; and in North America, the annual Tc-99m demand decreased from an estimated 20 million unit doses to about 15 million unit doses. Mo-99/Tc-99m is produced from HEU targets, irradiated in NRU for 11 days, and after chemical removal of uranium it is shipped to Nordion in Kanata, Ontario. Nordion further purifies the material and sends it to Lantheus Medical Imaging in the USA for manufacture of Mo-99 generators, which are then distributed to hundreds of hospital radiopharmacies throughout North America. One other American company, Covidien, manufactures and distributes Mo-99 generators like Lantheus, but they import bulk Mo-99 from Europe or South Africa. At the hospitals, Tc-99m is chemically extracted daily from the Mo-99 generators and loaded into syringes for immediate clinical use. Fortuitously, the 66 hour half-life of Mo-99 allows the replenishment of Tc-99m in the generator over a growth period of about 20 hours; and a generator can be 'milked' daily for up to two weeks. A more efficient model is the direct production and distribution of Tc-99m unit doses to regional hospitals from 10 'industrial' radiopharmacies located at existing licensed reactor sites in North America. A 20 kW homogeneous SLOWPOKE reactor at each site would deliver 15 litres of irradiated uranyl sulphate fuel solution daily to industrial-scale hot cells for extraction of Mo-99, which would be incorporated in large Mo-99/Tc-99m generators for extraction of Tc-99m five days a week; and the Low Enriched Uranium (LEU) would be recycled. Each automated hot-cell facility would be designed to load up to 7,000 Tc-99m syringes daily, for courier delivery to all of the Nuclear Medicine hospitals within a 3 hour average range by road transport. Typically, the delivered doses would be in the range 10 to 30 mCi. Assuming an average unit dose of 25 mCi at the hospital and 5 x 52

  10. Earth-Base: testing the temporal congruency of paleontological collections and geologic maps of North America

    Science.gov (United States)

    Heim, N. A.; Kishor, P.; McClennen, M.; Peters, S. E.

    2012-12-01

    Free and open source software and data facilitate novel research by allowing geoscientists to quickly and easily bring together disparate data that have been independently collected for many different purposes. The Earth-Base project brings together several datasets using a common space-time framework that is managed and analyzed using open source software. Earth-Base currently draws on stratigraphic, paleontologic, tectonic, geodynamic, seismic, botanical, hydrologic and cartographic data. Furthermore, Earth-Base is powered by RESTful data services operating on top of PostgreSQL and MySQL databases and the R programming environment, making much of the functionality accessible to third-parties even though the detailed data schemas are unknown to them. We demonstrate the scientific potential of Earth-Base and other FOSS by comparing the stated age of fossil collections to the age of the bedrock upon which they are geolocated. This analysis makes use of web services for the Paleobiology Database (PaleoDB), Macrostrat, the 2005 Geologic Map of North America (Garrity et al. 2009) and geologic maps of the conterminous United States. This analysis is a way to quickly assess the accuracy of temporal and spatial congruence of the paleontologic and geologic map datasets. We find that 56.1% of the 52,593 PaleoDB collections have temporally consistent ages with the bedrock upon which they are located based on the Geologic Map of North America. Surprisingly, fossil collections within the conterminous United States are more consistently located on bedrock with congruent geological ages, even though the USA maps are spatially and temporally more precise. Approximately 57% of the 37,344 PaleoDB collections in the USA are located on similarly aged geologic map units. Increased accuracy is attributed to the lumping of Pliocene and Quaternary geologic map units along the Atlantic and Gulf coastal plains in the Geologic Map of North America. The abundant Pliocene fossil collections

  11. Changes in atmospheric rivers and moisture transport over the Northeast Pacific and western North America in response to ENSO diversity

    Science.gov (United States)

    Kim, Hye-Mi; Zhou, Yang; Alexander, Michael A.

    2017-03-01

    The year-to-year changes in atmospheric rivers (ARs) and moisture transport over the northeast Pacific and western North America are investigated during December to February (DJF) from 1979/80 to 2015/16. Changes in AR frequency, intensity, and landfall characteristics are compared between three ENSO phases: central Pacific El Niño (CPEN), eastern Pacific El Niño (EPEN), and La Niña (NINA). During EPEN events, the subtropical jet extends to the south and east with an anomalous cyclonic flow around a deeper Aleutian Low. More moisture is transported towards North America and AR frequency is increased over western North America. In CPEN events, the Aleutian low shifts further southward relative to its position in EPEN, resulting in an increase in the frequency and intensity of landfalling ARs over the southwestern US. In NINA events, the landfalling AR frequency is reduced associated with anomalous anticyclonic circulation over the eastern North Pacific. We diagnose the contribution of multiple factors to the seasonal mean moisture transport using moisture budgets. During the three ENSO phases, the change in low-frequency circulation (dynamical process) is the leading contributor to the seasonal mean moisture flux divergence, while the contributions of the synoptic anomalies and the change in moisture anomaly (thermodynamic process) are not significant along the west coast of North America.

  12. The Unified North American Soil Map and Its Implication on the Soil Organic Carbon Stock in North America

    Science.gov (United States)

    Wei, Y.; Liu, S.; Huntzinger, D. N.; Michalak, A. M.; Post, W. M.; Cook, R. B.; Schaefer, K. M.; Thornton, M.

    2014-12-01

    The Unified North American Soil Map (UNASM) was developed by Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP) to provide more accurate regional soil information for terrestrial biosphere modeling. The UNASM combines information from state-of-the-art US STATSGO2 and Soil Landscape of Canada (SLCs) databases. The area not covered by these datasets is filled by using the Harmonized World Soil Database version 1.21 (HWSD1.21). The UNASM contains maximum soil depth derived from the data source as well as seven soil attributes (including sand, silt, and clay content, gravel content, organic carbon content, pH, and bulk density) for the topsoil layer (0-30 cm) and the subsoil layer (30-100 cm), respectively, of the spatial resolution of 0.25 degrees in latitude and longitude. There are pronounced differences in the spatial distributions of soil properties and soil organic carbon between UNASM and HWSD, but the UNASM overall provides more detailed and higher-quality information particularly in Alaska and central Canada. To provide more accurate and up-to-date estimate of soil organic carbon stock in North America, we incorporated Northern Circumpolar Soil Carbon Database (NCSCD) into the UNASM. The estimate of total soil organic carbon mass in the upper 100 cm soil profile based on the improved UNASM is 365.96 Pg, of which 23.1% is under trees, 14.1% is in shrubland, and 4.6% is in grassland and cropland. This UNASM data has been provided as a resource for use in terrestrial ecosystem modeling of MsTMIP both for input of soil characteristics and for benchmarking model output.

  13. Job satisfaction among chairs of surgery from Europe and North America.

    Science.gov (United States)

    Tschuor, Christoph; Raptis, Dimitri Aristotle; Morf, Manuela Christina; Staffelbach, Bruno; Manser, Tanja; Clavien, Pierre-Alain

    2014-11-01

    Strong evidence exists associating job satisfaction and risk of burnout with productivity, efficiency, and creativity in many organizations. However no data are available assessing chairs of surgery. This study assessed job satisfaction and risk for burnout of surgical chairs from Europe and North America and identified contributing factors. A survey among 650 chairs in surgery from 23 European and 2 North American countries was conducted in 2012. Satisfaction at work was analyzed using the validated Global Job Satisfaction (GJS) instrument and the abbreviated Maslach Burnout Inventory. Additional items targeting personal and environmental factors were included. The rate of chairs reached successfully was 86%, the overall response rate was 29% (188/650), with 1% female. Median age was 58 years. 11% of chairs were dissatisfied with work. Younger age and being fewer years in practice as a chair was associated with higher job satisfaction (P = .054 and P = .003). Surgical specialty with the greatest median GJS score was hepatopancreatobiliary, whereas vascular surgery scored lowest. Chairs desire to devote 20% more of their time on research. Clerical support as well as the ability to be innovative was suggested by 51% and 45%, respectively, to improve job satisfaction. Compared with Europeans, North American chairs were overall more satisfied and would recommend their job to their children. North American chairs seem to be more satisfied at work and at less risk for burnout than European chairs. The overall job satisfaction was greater among chairs compared with previously published reports of young, board-certified surgeons or residents (89% vs 87% and 66%, respectively). The superior satisfaction in chairs is strongest related to career achievements, innovation, and lifestyle. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Construction cost prediction model for conventional and sustainable college buildings in North America

    Directory of Open Access Journals (Sweden)

    Othman Subhi Alshamrani

    2017-03-01

    Full Text Available The literature lacks in initial cost prediction models for college buildings, especially comparing costs of sustainable and conventional buildings. A multi-regression model was developed for conceptual initial cost estimation of conventional and sustainable college buildings in North America. RS Means was used to estimate the national average of construction costs for 2014, which was subsequently utilized to develop the model. The model could predict the initial cost per square feet with two structure types made of steel and concrete. The other predictor variables were building area, number of floors and floor height. The model was developed in three major stages, such as preliminary diagnostics on data quality, model development and validation. The developed model was successfully tested and validated with real-time data.

  15. Plague bacterium as a transformer species in prairie dogs and the grasslands of western North America

    Science.gov (United States)

    Eads, David A.; Biggins, Dean E.

    2015-01-01

    Invasive transformer species change the character, condition, form, or nature of ecosystems and deserve considerable attention from conservation scientists. We applied the transformer species concept to the plague bacterium Yersinia pestis in western North America, where the pathogen was introduced around 1900. Y. pestis transforms grassland ecosystems by severely depleting the abundance of prairie dogs (Cynomys spp.) and thereby causing declines in native species abundance and diversity, including threatened and endangered species; altering food web connections; altering the import and export of nutrients; causing a loss of ecosystem resilience to encroaching invasive plants; and modifying prairie dog burrows. Y. pestis poses an important challenge to conservation biologists because it causes trophic-level perturbations that affect the stability of ecosystems. Unfortunately, understanding of the effects of Y. pestis on ecosystems is rudimentary, highlighting an acute need for continued research.

  16. 2001 Bhuj, India, earthquake engineering seismoscope recordings and Eastern North America ground-motion attenuation relations

    Science.gov (United States)

    Cramer, C.H.; Kumar, A.

    2003-01-01

    Engineering seismoscope data collected at distances less than 300 km for the M 7.7 Bhuj, India, mainshock are compatible with ground-motion attenuation in eastern North America (ENA). The mainshock ground-motion data have been corrected to a common geological site condition using the factors of Joyner and Boore (2000) and a classification scheme of Quaternary or Tertiary sediments or rock. We then compare these data to ENA ground-motion attenuation relations. Despite uncertainties in recording method, geological site corrections, common tectonic setting, and the amount of regional seismic attenuation, the corrected Bhuj dataset agrees with the collective predictions by ENA ground-motion attenuation relations within a factor of 2. This level of agreement is within the dataset uncertainties and the normal variance for recorded earthquake ground motions.

  17. Serologic evidence of influenza A (H14) virus introduction into North America

    Science.gov (United States)

    Latorre-Margalef, Neus; Ramey, Andy M.; Fojtik, Alinde; Stallknecht, David E.

    2015-01-01

    Although a diverse population of influenza A viruses (IAVs) is maintained among ducks, geese, shorebirds, and gulls, not all of the 16 avian hemagglutinin (HA) subtypes are equally represented (1). The 14th HA subtype, commonly known as the H14 subtype, was historically limited to isolates from the former Soviet Union in the 1980s (2) and was not subsequently detected until 2010, when isolated in Wisconsin, USA from long-tailed ducks and a white-winged scoter (3–5). In the United States, the H14 subtype has since been isolated in California (6), Mississippi, and Texas (7); and has been reported in waterfowl in Guatemala (7). In this study, we examined whether there was serologic evidence of H14 spread among ducks in North America before (2006–2010) and after (2011–2014) the initial detection of the H14 subtype virus on this continent.

  18. Psychobiography Training in Psychology in North America: Mapping the Field and Charting a Course

    Science.gov (United States)

    Ponterotto, Joseph G.; Reynolds, Jason D.; Morel, Samantha; Cheung, Linda

    2015-01-01

    Psychobiography holds an important position in the history of psychology, yet little is known about the status of psychobiographical training and dissertation research in psychology departments. This brief report identified psychobiography courses throughout North America and content analyzed a sample of 65 psychobiography dissertations to discern the theories and methods that have most commonly anchored this research. Results identified few psychology courses specifically in psychobiography, with a larger number of courses incorporating psychobiographical and/or narrative elements. With regard to psychobiography dissertations, the majority focused on artists, pioneering psychologists, and political leaders. Theories undergirding psychobiographical studies were most frequently psychoanalytic and psychodynamic. Methodologically, a majority of the dissertations were anchored in constructivist (discovery-oriented) qualitative procedures, with a minority incorporating mixed methods designs. The authors highlight the value of psychobiographical training to psychology students and present avenues and models for incorporating psychobiography into psychology curriculums. PMID:27247670

  19. Volatile organic compounds in indoor air: A review ofconcentrations measured in North America since 1990

    Energy Technology Data Exchange (ETDEWEB)

    ATHodgson@lbl.gov

    2003-04-01

    Central tendency and upper limit concentrations of volatile organic compounds (VOCs) measured in indoor air are summarized and reviewed. Data were obtained from published cross-sectional studies of residential and office buildings conducted in North America from 1990through the present. VOC concentrations in existing residences reported in 12 studies comprise the majority of the data set. Central tendency and maximum concentrations are compared between new and existing residences and between existing residences and office buildings. Historical changes in indoor VOC concentrations since the Clean Air Act Amendments of 1990 are explored by comparing the current data set with two published reviews of previous data obtained primarily in the 1980s. These historical comparisons suggest average indoor concentrations of some toxic air contaminants, such as 1,1,1-trichloroethane have decreased.

  20. Phantom Housing: The Rise and Fall of Public Housing in North America

    Directory of Open Access Journals (Sweden)

    Benjamin Gianni

    2012-11-01

    Full Text Available This paper examines the rise and fall of public housing in North America in order to explore the principle of sustainability. By extension, it addresses the concept of sustainability as it relates to the city. Urbanity is simultaneously the most and least sustainable form of development. While extremely sustainable from the point of view of density (economies of scale, efficient use ofinfrastructure, etc., it is highly vulnerable to social, political and economic forces. Such forces can easily trump the environmental sustainability of any building or community.The death and transfiguration of key portions of our public housing stock provides insights into this phenomenon – for which I will use Toronto’s Regent Park as a case study. The redevelopment ofthis 69-acre parcel aims to transform a failed social vision into a model for sustainable community development.

  1. Effect of Climate Change on Surface Ozone over North America, Europe, and East Asia

    Science.gov (United States)

    Schnell, Jordan L.; Prather, Michael J.; Josse, Beatrice; Naik, Vaishali; Horowitz, Larry W.; Zeng, Guang; Shindell, Drew T.; Faluvegi, Greg

    2016-01-01

    The effect of future climate change on surface ozone over North America, Europe, and East Asia is evaluated using present-day (2000s) and future (2100s) hourly surface ozone simulated by four global models. Future climate follows RCP8.5, while methane and anthropogenic ozone precursors are fixed at year-2000 levels. Climate change shifts the seasonal surface ozone peak to earlier in the year and increases the amplitude of the annual cycle. Increases in mean summertime and high-percentile ozone are generally found in polluted environments, while decreases are found in clean environments. We propose climate change augments the efficiency of precursor emissions to generate surface ozone in polluted regions, thus reducing precursor export to neighboring downwind locations. Even with constant biogenic emissions, climate change causes the largest ozone increases at high percentiles. In most cases, air quality extreme episodes become larger and contain higher ozone levels relative to the rest of the distribution.

  2. The difference between trivial and scientific names: There were never any true cheetahs in North America.

    Science.gov (United States)

    Faurby, S; Werdelin, L; Svenning, J C

    2016-05-05

    Dobrynin et al. (Genome Biol 16:277, 2015) recently published the complete genome of the cheetah (Acinonyx jubatus) and provided an exhaustive set of analyses supporting the famously low genetic variation in the species, known for several decades. Their genetic analyses represent state-of-the-art and we do not criticize them. However, their interpretation of the results is inconsistent with current knowledge of cheetah evolution. Dobrynin et al. suggest that the causes of the two inferred bottlenecks at ∼ 100,000 and 10,000 years ago were immigration by cheetahs from North America and end-Pleistocene megafauna extinction, respectively, but the first explanation is impossible and the second implausible.

  3. Alpine treeline of western North America: Linking organism-to-landscape dynamics

    Science.gov (United States)

    Malanson, George P.; Butler, David R.; Fagre, Daniel B.; Walsh, Stephen J; Tomback, Diana F.; Daniels, Lori D.; Resler, Lynn M.; Smith, William K.; Weiss, Daniel J.; Peterson, David L.; Bunn, Andrew G.; Hiemstra, Christopher A.; Liptzin, Daniel; Bourgeron, Patrick S.; Shen, Zehao; Millar, Constance I.

    2007-01-01

    Although the ecological dynamics of the alpine treeline ecotone are influenced by climate, it is an imperfect indicator of climate change. Mechanistic processes that shape the ecotone—seed rain, seed germination, seedling establishment and subsequent tree growth form, or, conversely tree dieback—depend on microsite patterns. Growth forms affect wind and snow, and so develop positive and negative feedback loops that create these microsites. As a result, complex landscape patterns are generated at multiple spatial scales. Although these mechanistic processes are fundamentally the same for all forest-tundra ecotones across western North America, factors such as prior climate, underlying geology and geomorphology, and genetic constraints of dominant tree species lead to geographic differences in the responses of particular ecotones to climate change.

  4. U.S. response to a report of infectious salmon anemia virus in Western North America

    Science.gov (United States)

    Amos, Kevin H; Gustafson, Lori; Warg, Janet; Whaley, Janet; Purcell, Maureen K.; Rolland, Jill B.; Winton, James R.; Snekvik, Kevin; Meyers, Theodore; Stewart, Bruce; Kerwin, John; Blair, Marilyn; Bader, Joel; Evered, Joy

    2014-01-01

    Federal, state, and tribal fishery managers, as well as the general public and their elected representatives in the United States, were concerned when infectious salmon anemia virus (ISAV) was suspected for the first time in free-ranging Pacific Salmon collected from the coastal areas of British Columbia, Canada. This article documents how national and regional fishery managers and fish health specialists of the U.S. worked together and planned and implemented actions in response to the reported finding of ISAV in British Columbia. To date, the reports by Simon Fraser University remain unconfirmed and preliminary results from collaborative U.S. surveillance indicate that there is no evidence of ISAV in U.S. populations of free-ranging or marine-farmed salmonids on the west coast of North America.

  5. Thermodynamic and Dynamic Causes of Pluvial Conditions During the Last Glacial Maximum in Western North America

    Science.gov (United States)

    Morrill, Carrie; Lowry, Daniel P.; Hoell, Andrew

    2018-01-01

    During the last glacial period, precipitation minus evaporation increased across the currently arid western United States. These pluvial conditions have been commonly explained for decades by a southward deflection of the jet stream by the Laurentide Ice Sheet. Here analysis of state-of-the-art coupled climate models shows that effects of the Laurentide Ice Sheet on the mean circulation were more important than storm track changes in generating wet conditions. Namely, strong cooling by the ice sheet significantly reduced humidity over land, increasing moisture advection in the westerlies due to steepened humidity gradients. Additionally, the removal of moisture from the atmosphere by mass divergence associated with the subtropical high was diminished at the Last Glacial Maximum compared to present. These same dynamic and thermodynamic factors, working in the opposite direction, are projected to cause regional drying in western North America under increased greenhouse gas concentrations, indicating continuity from past to future in the mechanisms altering hydroclimate.

  6. Socioeconomic status and fertility decline: Insights from historical transitions in Europe and North America

    Science.gov (United States)

    Dribe, Martin; Breschi, Marco; Gagnon, Alain; Gauvreau, Danielle; Hanson, Heidi A.; Maloney, Thomas N.; Mazzoni, Stanislao; Molitoris, Joseph; Pozzi, Lucia; Smith, Ken R.; Vézina, Hélène

    2016-01-01

    We have good knowledge of the timing of the historical fertility transitions in different regions, but we know much less regarding specific features and causes. In this study, we used longitudinal micro-level data for five local populations in Europe and North America to study the relationship between socioeconomic status and fertility during the transition. Using the same analytical model and identical class scheme, we examined the development of socioeconomic differences in marital fertility and related it to common theories on fertility behaviour. Our results do not provide support for the hypothesis of universally high fertility among the upper classes in pre-transitional society but support the idea that they acted as forerunners in the transition by reducing their fertility before other groups. Farmers and unskilled workers were latest to start to limit their fertility. Apart from this regularity, the patterns of class differences in fertility varied significantly among populations. PMID:27884093

  7. Cross-cultural undergraduate medical education in North America: theoretical concepts and educational approaches.

    Science.gov (United States)

    Reitmanova, Sylvia

    2011-04-01

    Cross-cultural undergraduate medical education in North America lacks conceptual clarity. Consequently, school curricula are unsystematic, nonuniform, and fragmented. This article provides a literature review about available conceptual models of cross-cultural medical education. The clarification of these models may inform the development of effective educational programs to enable students to provide better quality care to patients from diverse sociocultural backgrounds. The approaches to cross-cultural health education can be organized under the rubric of two specific conceptual models: cultural competence and critical culturalism. The variation in the conception of culture adopted in these two models results in differences in all curricular components: learning outcomes, content, educational strategies, teaching methods, student assessment, and program evaluation. Medical schools could benefit from more theoretical guidance on the learning outcomes, content, and educational strategies provided to them by governing and licensing bodies. More student assessments and program evaluations are needed in order to appraise the effectiveness of cross-cultural undergraduate medical education.

  8. Anatexis and metamorphism in tectonically thickened continental crust exemplified by the Sevier hinterland, western North America

    Science.gov (United States)

    Patino Douce, Alberto E.; Humphreys, Eugene D.; Johnston, A. Dana

    1990-01-01

    This paper presents a thermal and petrologic model of anatexis and metamorphism in regions of crustal thickening exemplified by the Sevier hinterland in western North America, and uses the model to examine the geological and physical processes leading to crustally derived magmatism. The results of numerical experiments show that anatexis was an inevitable end-product of Barrovian metamorphism in the thickened crust of the late Mesozoic Sevier orogenic belt and that the advection of heat across the lithosphere, in the form of mantle-derived mafic magmas, was not required for melting of metasedimentary rocks. It is suggested that, in the Sevier belt, as in other intracontinental orogenic belts, anatexis occurred in the midcrust and not at the base of the crust.

  9. Species dominance and equitability: patterns in Cenozoic foraminifera of eastern North America

    Science.gov (United States)

    Gibson, T.G.; Hill, E.E.

    1992-01-01

    Species dominance in benthonic foraminifera, represented by percent of the assemblage composed of the single most abundant species, shows little change in observed range of values from shallow into deep-marine waters in 1005 samples from the Gulf of Mexico, Atlantic, and Arctic margins of North America. This finding contrasts with the model that species dominance is highest in shallow-marine environments and decreases offshore into deeper marine waters. Equitability, the relation of all species abundances within an assemblage, also shows little change between the values found in shallow-marine assemblages and those found in assemblages from deeper water environments. Equitability and dominance values found in 421 assemblages from Palaeocene, Eocene, Miocene, and Pleistocene strata of the Atlantic and E Gulf of Mexico coastal plains are similar to the modern values. -from Authors

  10. Plague bacterium as a transformer species in prairie dogs and the grasslands of western North America.

    Science.gov (United States)

    Eads, David A; Biggins, Dean E

    2015-08-01

    Invasive transformer species change the character, condition, form, or nature of ecosystems and deserve considerable attention from conservation scientists. We applied the transformer species concept to the plague bacterium Yersinia pestis in western North America, where the pathogen was introduced around 1900. Y. pestis transforms grassland ecosystems by severely depleting the abundance of prairie dogs (Cynomys spp.) and thereby causing declines in native species abundance and diversity, including threatened and endangered species; altering food web connections; altering the import and export of nutrients; causing a loss of ecosystem resilience to encroaching invasive plants; and modifying prairie dog burrows. Y. pestis poses an important challenge to conservation biologists because it causes trophic-level perturbations that affect the stability of ecosystems. Unfortunately, understanding of the effects of Y. pestis on ecosystems is rudimentary, highlighting an acute need for continued research. © 2015 Society for Conservation Biology.

  11. North America grid segmentation case studies : technical feasibility and economics of implementation

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.L. [Bonneville Power Administration, Portland, OR (United States); Clark, H.K.; El-Gasseir, M.M.; Epp, H.D.K.; Woodford, D.A. [DC Interconnect Inc., Vancouver, BC (Canada); Barthold, L.O.; Reppen, N.D.

    2009-07-01

    There continues to be unprecedented demand on power grids. The primary requirement is for a highly resilient grid that includes large transmission capacity reserves. There is increased demand for total transfer capability (TTC) to meet renewables policy targets and improved accommodation of complex market transactions. Some potential components include storage, FACTS controllers, dynamic ACE and other technologies. This presentation proposed segmentation as a different solution in order to meet the same demands more economically and greatly enhance reliability. The presentation described how segmentation works and discussed the benefits of a simple controller. Segmentation benefits in system planning and operation were also outlined. Other topics that were presented included renewable generation; grid security; cascading; adjustments that an operator might make; line converter and high voltage direct current (HVDC) converter options; HVDC line and converter configurations; and segmentation studies in North America. Economic analyses were also discussed. The presentation concluded with a potential application in northern Europe. 3 figs.

  12. On the feasibility of real-time mapping of the geoelectric field across North America

    Science.gov (United States)

    Love, Jeffrey J.; Rigler, E. Joshua; Kelbert, Anna; Finn, Carol A.; Bedrosian, Paul A.; Balch, Christopher C.

    2018-06-08

    A review is given of the present feasibility for accurately mapping geoelectric fields across North America in near-realtime by modeling geomagnetic monitoring and magnetotelluric survey data. Should this capability be successfully developed, it could inform utility companies of magnetic-storm interference on electric-power-grid systems. That real-time mapping of geoelectric fields is a challenge is reflective of (1) the spatiotemporal complexity of geomagnetic variation, especially during magnetic storms, (2) the sparse distribution of ground-based geomagnetic monitoring stations that report data in realtime, (3) the spatial complexity of three-dimensional solid-Earth impedance, and (4) the geographically incomplete state of continental-scale magnetotelluric surveys.

  13. Four emerging arboviral diseases in North America: Jamestown Canyon, Powassan, chikungunya, and Zika virus diseases.

    Science.gov (United States)

    Pastula, Daniel M; Smith, Daniel E; Beckham, J David; Tyler, Kenneth L

    2016-06-01

    Arthropod-borne viruses, or arboviruses, are viruses that are transmitted through the bites of mosquitoes, ticks, or sandflies. There are numerous arboviruses throughout the world capable of causing human disease spanning different viral families and genera. Recently, Jamestown Canyon, Powassan, chikungunya, and Zika viruses have emerged as increasingly important arboviruses that can cause human disease in North America. Unfortunately, there are currently no proven disease-modifying therapies for these arboviral diseases, so treatment is largely supportive. Given there are also no commercially available vaccines for these four arboviral infections, prevention is the key. To prevent mosquito or tick bites that might result in one of these arboviral diseases, people should wear long-sleeved shirts and pants while outside if feasible, apply insect repellant when going outdoors, using window screens or air conditioning to keep mosquitoes outside, and perform tick checks after being in wooded or brushy outdoor areas.

  14. Composition and uses of anaerobic digestion derived biogas from wastewater treatment facilities in North America.

    Science.gov (United States)

    Lackey, Jillian C; Peppley, B; Champagne, P; Maier, A

    2015-08-01

    A study was conducted to determine the current knowledge of biogas production and its use at municipal wastewater treatment plants (WWTPs) across North America. Information was provided by municipal WWTPs across Canada and the US. It was determined that hydrogen sulfide (H2S) and silicon (Si) compounds had sufficient variability to be of concern. The only biogas production trend that could be identified was a possible seasonal relationship with sludge input and biogas production. Secondary analysis was performed to observe trends in biogas usage in urban areas larger than 150,000 in the US and 50,000 in Canada; 66% of facilities had anaerobic digestion systems and, of those, only 35% had an energy recovery system. Climatic, population, and socio-political influences on the trends were considered. The primary conclusion was that more data is required to perform significant analyses on biogas production and composition variation. © The Author(s) 2015.

  15. Portrayal of childhood cancer in English language magazines in North America: 1970-2001.

    Science.gov (United States)

    Clarke, Juanne

    2005-01-01

    This article is a content and discourse analysis of the portrayal of childhood cancer in English language magazines in North America. In a unique specification of published research on the media portrayal of disease, magazines were divided into three market or audience groupings called (1) science, (2) news/special interest, and (3) other (women/teen/parenting/health). The predominate frames or discoursesin these three groups were compared and differences were found amongst them and discussed in the article. Considerable evidence suggests that people with cancer are stigmatized. In the analyzed media focused on children, those with cancer are highly idealized and stereotyped. On the one hand, this can be thought of as a very positive portrayal of children in this situation. Children are described as if they possess heroic and idealized character traits, appearances, social characteristics, and personalities. Possible links between this idealized, polarized, and biased portrayal of children with cancer and their documented experiences of stigma are discussed.

  16. Anthropogenic impacts on mosquito populations in North America over the past century

    Science.gov (United States)

    Rochlin, Ilia; Faraji, Ary; Ninivaggi, Dominick V.; Barker, Christopher M.; Kilpatrick, A. Marm

    2016-12-01

    The recent emergence and spread of vector-borne viruses including Zika, chikungunya and dengue has raised concerns that climate change may cause mosquito vectors of these diseases to expand into more temperate regions. However, the long-term impact of other anthropogenic factors on mosquito abundance and distributions is less studied. Here, we show that anthropogenic chemical use (DDT; dichlorodiphenyltrichloroethane) and increasing urbanization were the strongest drivers of changes in mosquito populations over the last eight decades in areas on both coasts of North America. Mosquito populations have increased as much as tenfold, and mosquito communities have become two- to fourfold richer over the last five decades. These increases are correlated with the decay in residual environmental DDT concentrations and growing human populations, but not with temperature. These results illustrate the far-reaching impacts of multiple anthropogenic disturbances on animal communities and suggest that interactions between land use and chemical use may have unforeseen consequences on ecosystems.

  17. Avian bornavirus in free-ranging waterfowl in North America and Europe

    DEFF Research Database (Denmark)

    Brinkmann, Jesper; Thomsen, Anders F.; Bertelsen, Mads Frost

    The first avian bornavirus (ABV) was identified in 2008 by researchers investigating the cause of proventricular dilation disease in psittacine birds 3,4. A distinctly separate genotype (ABV-CG) was discovered in 2009 in association with neurological disease in free-ranging Canada geese (Branta...... canadensis) and trumpeter swans (Cygnus buccinator) in Ontario, Canada 1. Since then this genotype, now identified as ABBV-1, has been identified from a variety of wild avian species 5, predominantly waterfowl, in North America at prevalences ranging from 10 to 50%, and in 2014 an additional genotype...... was identified in mallard ducks (Anas platyrhynchos) 2. In order to determine whether avian bornavirus was present in European waterfowl, the brains of 333 hunter killed geese in Denmark were examined by real time RT-PCR for the presence of avian bornavirus; seven birds (2.1%) were positive. Sequences were 98...

  18. New elmisaurine specimens from North America and their relationship to the Mongolian Elmisaurus rarus

    Directory of Open Access Journals (Sweden)

    Gregory F. Funston

    2016-02-01

    Full Text Available New specimens from Canada confirm the presence of elmisaurines in North America and shed light on the relationship of Leptorhynchos elegans to Mongolian forms. These specimens have hindlimb elements previously unknown from elmisaurines in the Dinosaur Park Formation, including tibiae and pedal phalanges. Metatarsal anatomy is sufficiently different to merit a generic distinction from Elmisaurus rarus, and both can be distinguished from Caenagnathus collinsi Sternberg, 1940 and Chirostenotes pergracilis. Differences between these taxa include body size, degree of coossification of the tarsometatarsus, and development of cruciate ridges of the third metatarsal. Histological analysis confirms that these differences are not correlated with ontogenetic age of the specimens. The results support the informal separation of caenagnathids based on metatarsal structure, and allow comments on paleobiological differences between caenagnathids and oviraptorids.

  19. Volcano-induced regime shifts in millennial tree-ring chronologies from northeastern North America.

    Science.gov (United States)

    Gennaretti, Fabio; Arseneault, Dominique; Nicault, Antoine; Perreault, Luc; Bégin, Yves

    2014-07-15

    Dated records of ice-cap growth from Arctic Canada recently suggested that a succession of strong volcanic eruptions forced an abrupt onset of the Little Ice Age between A.D. 1275 and 1300 [Miller GH, et al. (2012) Geophys Res Lett 39(2):L02708, 10.1029/2011GL050168]. Although this idea is supported by simulation experiments with general circulation models, additional support from field data are limited. In particular, the Northern Hemisphere network of temperature-sensitive millennial tree-ring chronologies, which principally comprises Eurasian sites, suggests that the strongest eruptions only caused cooling episodes lasting less than about 10 y. Here we present a new network of millennial tree-ring chronologies from the taiga of northeastern North America, which fills a wide gap in the network of the Northern Hemisphere's chronologies suitable for temperature reconstructions and supports the hypothesis that volcanoes triggered both the onset and the coldest episode of the Little Ice Age. Following the well-expressed Medieval Climate Anomaly (approximately A.D. 910-1257), which comprised the warmest decades of the last millennium, our tree-ring-based temperature reconstruction displays an abrupt regime shift toward lower average summer temperatures precisely coinciding with a series of 13th century eruptions centered around the 1257 Samalas event and closely preceding ice-cap expansion in Arctic Canada. Furthermore, the successive 1809 (unknown volcano) and 1815 (Tambora) eruptions triggered a subsequent shift to the coldest 40-y period of the last 1100 y. These results confirm that series of large eruptions may cause region-specific regime shifts in the climate system and that the climate of northeastern North America is especially sensitive to volcanic forcing.

  20. Spatiotemporal patterns of mercury accumulation in lake sediments of western North America

    Science.gov (United States)

    Drevnick, Paul; Cooke, Colin A.; Barraza, Daniella; Blais, Jules M.; Coale, Kenneth; Cumming, Brian F.; Curtis, Chris; Das, Biplob; Donahue, William F.; Eagles-Smith, Collin A.; Engstrom, Daniel R.; Fitzgerald, William F.; Furl, Chad V.; Gray, John R.; Hall, Roland I.; Jackson, Togwell A.; Laird, Kathleen R.; Lockhart, W. Lyle; Macdonald, Robie W.; Mast, M. Alisa; Mathieu, Callie; Muir, Derek C.G.; Outridge, Peter; Reinemann, Scott; Rothenberg, Sarah E.; Ruiz-Fernandex, Ana Carolina; St. Louis, V.L.; Sanders, Rhea; Sanei, Hamed; Skierszkan, Elliott; Van Metre, Peter C.; Veverica, Timothy; Wiklund, Johan A.; Wolfe, Brent B.

    2016-01-01

    For the Western North America Mercury Synthesis, we compiled mercury records from 165 dated sediment cores from 138 natural lakes across western North America. Lake sediments are accepted as faithful recorders of historical mercury accumulation rates, and regional and sub-regional temporal and spatial trends were analyzed with descriptive and inferential statistics. Mercury accumulation rates in sediments have increased, on average, four times (4×) from 1850 to 2000 and continue to increase by approximately 0.2 μg/m2 per year. Lakes with the greatest increases were influenced by the Flin Flon smelter, followed by lakes directly affected by mining and wastewater discharges. Of lakes not directly affected by point sources, there is a clear separation in mercury accumulation rates between lakes with no/little watershed development and lakes with extensive watershed development for agricultural and/or residential purposes. Lakes in the latter group exhibited a sharp increase in mercury accumulation rates with human settlement, stabilizing after 1950 at five times (5×) 1850 rates. Mercury accumulation rates in lakes with no/little watershed development were controlled primarily by relative watershed size prior to 1850, and since have exhibited modest increases (in absolute terms and compared to that described above) associated with (regional and global) industrialization. A sub-regional analysis highlighted that in the ecoregion Northwestern Forest Mountains, mercury deposited to watersheds is delivered to lakes. Research is warranted to understand whether mountainous watersheds act as permanent sinks for mercury or if export of “legacy” mercury (deposited in years past) will delay recovery when/if emissions reductions are achieved.

  1. Contingent Pacific-Atlantic Ocean influence on multicentury wildfire synchrony over western North America.

    Science.gov (United States)

    Kitzberger, Thomas; Brown, Peter M; Heyerdahl, Emily K; Swetnam, Thomas W; Veblen, Thomas T

    2007-01-09

    Widespread synchronous wildfires driven by climatic variation, such as those that swept western North America during 1996, 2000, and 2002, can result in major environmental and societal impacts. Understanding relationships between continental-scale patterns of drought and modes of sea surface temperatures (SSTs) such as El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO) may explain how interannual to multidecadal variability in SSTs drives fire at continental scales. We used local wildfire chronologies reconstructed from fire scars on tree rings across western North America and independent reconstructions of SST developed from tree-ring widths at other sites to examine the relationships of multicentury patterns of climate and fire synchrony. From 33,039 annually resolved fire-scar dates at 238 sites (the largest paleofire record yet assembled), we examined forest fires at regional and subcontinental scales. Since 1550 CE, drought and forest fires covaried across the West, but in a manner contingent on SST modes. During certain phases of ENSO and PDO, fire was synchronous within broad subregions and sometimes asynchronous among those regions. In contrast, fires were most commonly synchronous across the West during warm phases of the AMO. ENSO and PDO were the main drivers of high-frequency variation in fire (interannual to decadal), whereas the AMO conditionally changed the strength and spatial influence of ENSO and PDO on wildfire occurrence at multidecadal scales. A current warming trend in AMO suggests that we may expect an increase in widespread, synchronous fires across the western U.S. in coming decades.

  2. Estimating Snow Water Storage in North America Using CLM4, DART, and Snow Radiance Data Assimilation

    Science.gov (United States)

    Kwon, Yonghwan; Yang, Zong-Liang; Zhao, Long; Hoar, Timothy J.; Toure, Ally M.; Rodell, Matthew

    2016-01-01

    This paper addresses continental-scale snow estimates in North America using a recently developed snow radiance assimilation (RA) system. A series of RA experiments with the ensemble adjustment Kalman filter are conducted by assimilating the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) brightness temperature T(sub B) at 18.7- and 36.5-GHz vertical polarization channels. The overall RA performance in estimating snow depth for North America is improved by simultaneously updating the Community Land Model, version 4 (CLM4), snow/soil states and radiative transfer model (RTM) parameters involved in predicting T(sub B) based on their correlations with the prior T(sub B) (i.e., rule-based RA), although degradations are also observed. The RA system exhibits a more mixed performance for snow cover fraction estimates. Compared to the open-loop run (0.171m RMSE), the overall snow depth estimates are improved by 1.6% (0.168m RMSE) in the rule-based RA whereas the default RA (without a rule) results in a degradation of 3.6% (0.177mRMSE). Significant improvement of the snow depth estimates in the rule-based RA as observed for tundra snow class (11.5%, p < 0.05) and bare soil land-cover type (13.5%, p < 0.05). However, the overall improvement is not significant (p = 0.135) because snow estimates are degraded or marginally improved for other snow classes and land covers, especially the taiga snow class and forest land cover (7.1% and 7.3% degradations, respectively). The current RA system needs to be further refined to enhance snow estimates for various snow types and forested regions.

  3. Consistency Between Sun-Induced Chlorophyll Fluorescence and Gross Primary Production of Vegetation in North America

    Science.gov (United States)

    Zhang, Yao; Xiao, Xiangming; Jin, Cui; Dong, Jinwei; Zhou, Sha; Wagle, Pradeep; Joiner, Joanna; Guanter, Luis; Zhang, Yongguang; Zhang , Geli; hide

    2016-01-01

    Accurate estimation of the gross primary production (GPP) of terrestrial ecosystems is vital for a better understanding of the spatial-temporal patterns of the global carbon cycle. In this study,we estimate GPP in North America (NA) using the satellite-based Vegetation Photosynthesis Model (VPM), MODIS (Moderate Resolution Imaging Spectrometer) images at 8-day temporal and 500 meter spatial resolutions, and NCEP-NARR (National Center for Environmental Prediction-North America Regional Reanalysis) climate data. The simulated GPP (GPP (sub VPM)) agrees well with the flux tower derived GPP (GPPEC) at 39 AmeriFlux sites (155 site-years). The GPP (sub VPM) in 2010 is spatially aggregated to 0.5 by 0.5-degree grid cells and then compared with sun-induced chlorophyll fluorescence (SIF) data from Global Ozone Monitoring Instrument 2 (GOME-2), which is directly related to vegetation photosynthesis. Spatial distribution and seasonal dynamics of GPP (sub VPM) and GOME-2 SIF show good consistency. At the biome scale, GPP (sub VPM) and SIF shows strong linear relationships (R (sup 2) is greater than 0.95) and small variations in regression slopes ((4.60-5.55 grams Carbon per square meter per day) divided by (milliwatts per square meter per nanometer per square radian)). The total annual GPP (sub VPM) in NA in 2010 is approximately 13.53 petagrams Carbon per year, which accounts for approximately 11.0 percent of the global terrestrial GPP and is within the range of annual GPP estimates from six other process-based and data-driven models (11.35-22.23 petagrams Carbon per year). Among the seven models, some models did not capture the spatial pattern of GOME-2 SIF data at annual scale, especially in Midwest cropland region. The results from this study demonstrate the reliable performance of VPM at the continental scale, and the potential of SIF data being used as a benchmark to compare with GPP models.

  4. Prioritizing Zoonotic Diseases: Differences in Perspectives Between Human and Animal Health Professionals in North America.

    Science.gov (United States)

    Ng, V; Sargeant, J M

    2016-05-01

    Zoonoses pose a significant burden of illness in North America. Zoonoses represent an additional threat to public health because the natural reservoirs are often animals, particularly wildlife, thus eluding control efforts such as quarantine, vaccination and social distancing. As there are limited resources available, it is necessary to prioritize diseases in order to allocate resources to those posing the greatest public health threat. Many studies have attempted to prioritize zoonoses, but challenges exist. This study uses a quantitative approach, conjoint analysis (CA), to overcome some limitations of traditional disease prioritization exercises. We used CA to conduct a zoonoses prioritization study involving a range of human and animal health professionals across North America; these included epidemiologists, public health practitioners, research scientists, physicians, veterinarians, laboratory technicians and nurses. A total of 699 human health professionals (HHP) and 585 animal health professionals (AHP) participated in this study. We used CA to prioritize 62 zoonotic diseases using 21 criteria. Our findings suggest CA can be used to produce reasonable criteria scores for disease prioritization. The fitted models were satisfactory for both groups with a slightly better fit for AHP compared to HHP (84.4% certainty fit versus 83.6%). Human-related criteria were more influential for HHP in their decision to prioritize zoonoses, while animal-related criteria were more influential for AHP resulting in different disease priority lists. While the differences were not statistically significant, a difference of one or two ranks could be considered important for some individuals. A potential solution to address the varying opinions is discussed. The scientific framework for disease prioritization presented can be revised on a regular basis by updating disease criteria to reflect diseases as they evolve over time; such a framework is of value allowing diseases of

  5. Hg concentrations in fish from coastal waters of California and Western North America

    Science.gov (United States)

    Davis, Jay; Ross, John; Bezalel, Shira; Sim, Lawrence; Bonnema, Autumn; Ichikawa, Gary; Heim, Wes; Schiff, Kenneth C; Eagles-Smith, Collin A.; Ackerman, Joshua T.

    2016-01-01

    The State of California conducted an extensive and systematic survey of mercury (Hg) in fish from the California coast in 2009 and 2010. The California survey sampled 3483 fish representing 46 species at 68 locations, and demonstrated that methylHg in fish presents a widespread exposure risk to fish consumers. Most of the locations sampled (37 of 68) had a species with an average concentration above 0.3 μg/g wet weight (ww), and 10 locations an average above 1.0 μg/g ww. The recent and robust dataset from California provided a basis for a broader examination of spatial and temporal patterns in fish Hg in coastal waters of Western North America. There is a striking lack of data in publicly accessible databases on Hg and other contaminants in coastal fish. An assessment of the raw data from these databases suggested the presence of relatively high concentrations along the California coast and in Puget Sound, and relatively low concentrations along the coasts of Alaska and Oregon, and the outer coast of Washington. The dataset suggests that Hg concentrations of public health concern can be observed at any location on the coast of Western North America where long-lived predator species are sampled. Output from a linear mixed-effects model resembled the spatial pattern observed for the raw data and suggested, based on the limited dataset, a lack of trend in fish Hg over the nearly 30-year period covered by the dataset. Expanded and continued monitoring, accompanied by rigorous data management procedures, would be of great value in characterizing methylHg exposure, and tracking changes in contamination of coastal fish in response to possible increases in atmospheric Hg emissions in Asia, climate change, and terrestrial Hg control efforts in coastal watersheds.

  6. Risk factors for equine fractures in Thoroughbred flat racing in North America.

    Science.gov (United States)

    Georgopoulos, Stamatis Panagiotis; Parkin, Tim D H

    2017-04-01

    The aim of this paper is to identify risk factors associated with equine fractures in flat horse racing of Thoroughbreds in North America. Equine fractures were defined as any fracture sustained by a horse during a race. This was a cohort study that made use of all starts from the racecourses reporting injuries. The analysis was based on 2,201,152 racing starts that represent 91% of all official racing starts in the USA and Canada from 1st January 2009-31st December 2014. Approximately 3,990,000 workout starts made by the 171,523 Thoroughbreds that raced during that period were also included in the analysis. During this period the incidence of equine fractures was 2 per 1000 starts. The final multivariable logistic regression models identified risk factors significantly associated (pfracture. For example, horses were found to have a 32% higher chance of sustaining a fracture when racing on a dirt surface compared to a synthetic surface; a 35% higher chance if they had sustained a previous injury during racing and a 47% higher chance was also found for stallions compared to mares and geldings. Furthermore, logistic regression models based on data available only from the period 2009-2013 were used to predict the probability of a Thoroughbred sustaining a fracture for 2014. The 5% of starts that had the highest score in our predictive models for 2014 were found to have 2.4 times (95% CI: 1.9-2.9) higher fracture prevalence than the mean fracture prevalence of 2014. The results of this study can be used to identify horses at higher risk on entering a race and could help inform the design and implementation of preventive measures aimed at minimising the number of Thoroughbreds sustaining fractures during racing in North America. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Forest cover of North America in the 1970s mapped using Landsat MSS data

    Science.gov (United States)

    Feng, M.; Sexton, J. O.; Channan, S.; Townshend, J. R.

    2015-12-01

    The distribution and changes in Earth's forests impact hydrological, biogeochemical, and energy fluxes, as well as ecosystems' capacity to support biodiversity and human economies. Long-term records of forest cover are needed across a broad range of investigation, including climate and carbon-cycle modeling, hydrological studies, habitat analyzes, biological conservation, and land-use planning. Satellite-based observations enable mapping and monitoring of forests at ecologically and economically relevant resolutions and continental or even global extents. Following early forest-mapping efforts using coarser resolution remote sensing data such as the Advanced Very High Resolution Radiometer (AVHRR) and MODerate-resolution Imaging Spectroradiometer (MODIS), forests have been mapped regionally at developed by the Global Land Cover Facility (GLCF) as reference, we developed an automated approach to detect forests using MSS data by leveraging the multispectral and phenological characteristics of forests observed in MSS time-series. The forest-cover map is produced with layers representing the year of observation, detection of forest-cover change relative to 1990, and the uncertainty of forest-cover and -change layers. The approach has been implemented with open-source libraries to facilitate processing large volumes of Landsat MSS images on high-performance computing machines. As the first result of our global mapping effort, we present the forest cover for North America. More than 25,000 Landsat MSS scenes were processed to provide a 120-meter resolution forest cover for North America, which will be made publicly available on the GLCF website (http://www.landcover.org).

  8. Seismic hazard map of North and Central America and the Caribbean

    Directory of Open Access Journals (Sweden)

    K. M. Shedlock

    1999-06-01

    Full Text Available Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of seismic hazard. National, state, and local governments, decision makers, engineers, planners, emergency response organizations, builders, universities, and the general public require seismic hazard estimates for land use planning, improved building design and construction (including adoption of building construction codes, emergency response preparedness plans, economic forecasts, housing and employment decisions, and many more types of risk mitigation. The seismic hazard map of North and Central America and the Caribbean is the concatenation of various national and regional maps, involving a suite of approaches. The combined maps and documentation provide a useful regional seismic hazard framework and serve as a resource for any national or regional agency for further detailed studies applicable to their needs. This seismic hazard map depicts Peak Ground Acceleration (PGA with a 10% chance of exceedance in 50 years. PGA, a short-period ground motion parameter that is proportional to force, is the most commonly mapped ground motion parameter because current building codes that include seismic provisions specify the horizontal force a building should be able to withstand during an earthquake. This seismic hazard map of North and Central America and the Caribbean depicts the likely level of short-period ground motion from earthquakes in a fifty-year window. Short-period ground motions effect short-period structures (e.g., one-to-two story buildings. The highest seismic hazard values in the region generally occur in areas that have been, or are likely to be, the sites of the largest plate boundary earthquakes.

  9. Education and employment status of children and adults with thalassemia in North America.

    Science.gov (United States)

    Pakbaz, Zahra; Treadwell, Marsha; Kim, Hae-Young; Trachtenberg, Felicia; Parmar, Nagina; Kwiatkowski, Janet L; Cunningham, Melody J; Martin, Marie; Sweeters, Nancy; Neufeld, Ellis J; Giardina, Patricia J; Olivieri, Nancy; Yamashita, Robert C; Vichinsky, Elliott

    2010-10-01

    Advances in the management of thalassemia have resulted in increased life expectancy and new challenges. We conducted the first survey of education and employment status of people with thalassemia in North America. A total of 633 patients (349 adults and 284 school age children) enrolled in the Thalassemia Clinical Research Network (TCRN) registry in Canada and the U.S. were included in the data analysis. Predictors considered for analysis were age, gender, race/ethnicity, site of treatment (Canada vs. United States), transfusion and chelation status, serum ferritin, and clinical complications. Seventy percent of adults were employed of which 67% reported working full-time. Sixty percent had a college degree and 14% had achieved some post-college education. Eighty-two percent of school age children were at expected grade level. In a multivariate analysis for adults, Whites (OR = 2.76, 95% CI: 1.50-5.06) were more likely to be employed compared to Asians. Higher education in adults was associated with older age (OR = 1.67, 95% CI: 1.29-2.15), female gender (OR = 2.08, 95% CI: 1.32-3.23) and absence of lung disease (OR = 14.3, 95% CI: 2.04-100). Younger children (OR = 5.7 for 10-year increments, 95% CI: 2.0-16.7) and Canadian patients (OR = 5.6, 95% CI: 1.5-20) were more likely to be at the expected education level. Neither transfusion nor chelation was associated with lower employment or educational achievement. Individuals with thalassemia in North America can achieve higher education; however, full-time employment remains a problem. Transfusion and chelation do not affect employment or education status of this patient population. Copyright 2010 Wiley-Liss, Inc.

  10. Medical use of cannabis and cannabinoids containing products - Regulations in Europe and North America.

    Science.gov (United States)

    Abuhasira, Ran; Shbiro, Liat; Landschaft, Yuval

    2018-03-01

    In 1937, the United States of America criminalized the use of cannabis and as a result its use decreased rapidly. In recent decades, there is a growing interest in the wide range of medical uses of cannabis and its constituents; however, the laws and regulations are substantially different between countries. Laws differentiate between raw herbal cannabis, cannabis extracts, and cannabinoid-based medicines. Both the European Medicines Agency (EMA) and the United States Food and Drug Administration (FDA) do not approve the use of herbal cannabis or its extracts. The FDA approved several cannabinoid-based medicines, so did 23 European countries and Canada. However, only four of the reviewed countries have fully authorized the medical use of herbal cannabis - Canada, Germany, Israel and the Netherlands, together with more than 50% of the states in the United States. Most of the regulators allow the physicians to decide what specific indications they will prescribe cannabis for, but some regulators dictate only specific indications. The aim of this article is to review the current (as of November 2017) regulations of medical cannabis use in Europe and North America. Copyright © 2018 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  11. Stranieri e vicini: le banche attraverso le frontiere del nord America. (Strangers and neighbours: cross-border banking in North America

    Directory of Open Access Journals (Sweden)

    J.W. DEAN

    2013-12-01

    Full Text Available L'articolo si occupa di aspetti normativi e competitivi della penetrazione reciproca da parte delle banche canadesi e statunitensi nei rispettivi mercati nazionali . Gli autori valutano il grado in cui i fattori economici sono gli unici responsabili per la differenza nei tassi di crescita tra le banche nazionali ed estere in Nord America. Essi sostengono che il regolamento non ha inciso sullala crescita delle banche estere in Nord America affrontando la questione della reciprocità in regolamenti bancari , prima di esaminare le banche estere negli Stati Uniti e il modo in cui sono state regolamentate .The paper is concerned with regulatory and competitive aspects of the mutual penetration by Canadian and U.S. banks of each other’s domestic markets. The authors assess the degree to which economic factors alone are responsible for the difference in growth rates between domestic and foreign banks in North America. They argue that regulation has not affected the growth of foreign banks in North America by addressing the question of reciprocity in banking regulations, before examining foreign banks in the U.S. and the manner in which they have been regulated. U.S. banks operating in Canada are then dealt with. Finally, the results of an empirical test of the proposition that the growth of cross-border banking is attributable to factors other than differential regulation is presented.JEL: G21

  12. Evaluation of operational on-line-coupled regional air quality models over Europe and North America in the context of AQMEII phase 2. Part I: Ozone

    NARCIS (Netherlands)

    Im, U.; Bianconi, R.; Solazzo, E.; Kioutsioukis, I.; Badia, A.; Balzarini, A.; Baró, R.; Bellasio, R.; Brunner, D.; Chemel, C.; Curci, G.; Flemming, J.; Forkel, R.; Giordano, L.; Jiménez-Guerrero, P.; Hirtl, M.; Hodzic, A.; Honzak, L.; Jorba, O.; Knote, C.; Kuenen, J.J.P.; Makar, P.A.; Manders-Groot, A.; Neal, L.; Pérez, J.L.; Pirovano, G.; Pouliot, G.; San Jose, R.; Savage, N.; Schroder, W.; Sokhi, R.S.; Syrakov, D.; Torian, A.; Tuccella, P.; Werhahn, J.; Wolke, R.; Yahya, K.; Zabkar, R.; Zhang, Y.; Zhang, J.; Hogrefe, C.; Galmarini, S.

    2015-01-01

    The second phase of the Air Quality Model Evaluation International Initiative (AQMEII) brought together sixteen modeling groups from Europe and North America, running eight operational online-coupled air quality models over Europe and North America on common emissions and boundary conditions. With

  13. Bark-peeling, food stress and tree spirits - the use of pine inner bark for food in Scandinavia and North America

    Science.gov (United States)

    Lars Ostlund; Lisa Ahlberg; Olle Zackrisson; Ingela Bergman; Steve Arno

    2009-01-01

    The Sami people of northern Scandinavia and many indigenous peoples of North America have used pine (Pinus spp.) inner bark for food, medicine and other purposes. This study compares bark-peeling and subsequent uses of pine inner bark in Scandinavia and western North America, focusing on traditional practices. Pine inner bark contains substances - mainly carbohydrates...

  14. Transmission patterns of smallpox: Systematic review of natural outbreaks in Europe and North America since World War II

    NARCIS (Netherlands)

    V. Bhatnagar (Vibha); M.A. Stoto (Michael); S.C. Morton (Sally); R. Boer (Rob); S.A. Bozzette (Samuel)

    2006-01-01

    textabstractBackground: Because smallpox (variola major) may be used as a biological weapon, we reviewed outbreaks in post-World War II Europe and North America in order to understand smallpox transmission patterns. Methods: A systematic review was used to identify papers from the National Library

  15. Specific gravity and other properties of wood and bark for 156 tree species found in North America

    Science.gov (United States)

    Patrick D. Miles

    2009-01-01

    This paper reports information for the estimation of biomass for 156 tree species found in North America for use in national forest inventory applications. We present specific gravities based on average green volume as well as 12 percent moisture content volume for calculation of oven-dry biomass....

  16. An Evaluation of the Role of Ozone, Acid Deposition, and other Airborne Pollutants in the Forests of Eastern North America

    Science.gov (United States)

    J.H.B. Garner; Terry Pagano; Ellis B. Cowling

    1989-01-01

    Existing knowledge on air pollutants that occur in the forests of eastern North America is summarized and interpreted.Resolution is sought to the conflict between the prevailing scientific judgment that ozone and other oxidants are most likely to be damaging eastern forests and the prevailing public perception that acidic and acidifying substances are the most likely...

  17. 78 FR 21189 - Petition for Exemption From the Vehicle Theft Prevention Standard; BMW of North America, LLC

    Science.gov (United States)

    2013-04-09

    ... From the Vehicle Theft Prevention Standard; BMW of North America, LLC AGENCY: National Highway Traffic... device and allow the vehicle to start. When the EWS/CAS control unit has sent a correct release signal... and only then will the ignition signal and fuel supply be released. BMW stated that the vehicle is...

  18. LETHALITY OF PSEUDOMONAS FLUORESCENS STRAIN CLO145A TO THE 2 ZEBRA MUSSEL SPECIES PRESENT IN NORTH AMERICA

    International Nuclear Information System (INIS)

    Molloy, Daniel P.

    2001-01-01

    These experiments indicated that bacterial strain CL0145A of Pseudomonas fluorescens is equally lethal to the 2 zebra mussel species present in North America, Dreissena polymorpha and Dreissena bugensis. Thus, this bacterial strain should be equally effective at killing zebra mussels in power plant pipes, irrespective of which species is present

  19. Earliest Human Presence in North America Dated to the Last Glacial Maximum: New Radiocarbon Dates from Bluefish Caves, Canada.

    Directory of Open Access Journals (Sweden)

    Lauriane Bourgeon

    Full Text Available The timing of the first entry of humans into North America is still hotly debated within the scientific community. Excavations conducted at Bluefish Caves (Yukon Territory from 1977 to 1987 yielded a series of radiocarbon dates that led archaeologists to propose that the initial dispersal of human groups into Eastern Beringia (Alaska and the Yukon Territory occurred during the Last Glacial Maximum (LGM. This hypothesis proved highly controversial in the absence of other sites of similar age and concerns about the stratigraphy and anthropogenic signature of the bone assemblages that yielded the dates. The weight of the available archaeological evidence suggests that the first peopling of North America occurred ca. 14,000 cal BP (calibrated years Before Present, i.e., well after the LGM. Here, we report new AMS radiocarbon dates obtained on cut-marked bone samples identified during a comprehensive taphonomic analysis of the Bluefish Caves fauna. Our results demonstrate that humans occupied the site as early as 24,000 cal BP (19,650 ± 130 14C BP. In addition to proving that Bluefish Caves is the oldest known archaeological site in North America, the results offer archaeological support for the "Beringian standstill hypothesis", which proposes that a genetically isolated human population persisted in Beringia during the LGM and dispersed from there to North and South America during the post-LGM period.

  20. Flavonoids and heart health: Proceedings of the ILSI North America Flavonoids Workshop may 31-june 1, 2005, Washington DC

    NARCIS (Netherlands)

    Erdman, J.W.; Balentine, D.; Arab, L.; Beecher, G.; Dwyer, J.T.; Folts, J.; Harnly, J.; Hollman, P.C.H.; Keen, C.L.; Mazza, G.; Messina, M.; Scalbert, A.; Vita, J.; Williamson, G.; Burrows, J.

    2007-01-01

    This article provides an overview of current research on flavonoids as presented during a workshop entitled, "Flavonoids and Heart Health," held by the ILSI North America Project Committee on Flavonoids in Washington, DC, May 31 and June 1, 2005. Because a thorough knowledge and understanding about

  1. Insights into the ecology, genetics and distribution of Lucanus elaphus Fabricius (Coleoptera: Lucanidae), North America's giant stag beetle

    Science.gov (United States)

    Michael D. Ulyshen; Louis G. Zachos; John O. Stireman; Thomas N. Sheehan; Ryan C. Garrick

    2017-01-01

    1. Little is known about the biology or conservation status of Lucanus elaphus Fabricius in North America despite well-documented declines of a related species, Lucanus cervus (L.), in Europe. This study provides information critical to developing conservation plans for L. elaphus...

  2. A lesser frigatebird (Fregata ariel) in California: a first for the state and fourth for North America

    Science.gov (United States)

    Brain L Sullivan; Marshall J. Iliff; Peter L. Ralph; C. J. Ralph; Steven T. Kelling

    2007-01-01

    This paper summarizes the occurrence and identification of California's first Lesser Frigatebird (Fregata ariel), a subadult female photographed on 15 July 2007 at Lanphere Dunes near Arcata, Humboldt Country. This record is the fourth of this species for North America and the first in the eastern Pacific Ocean of the Western Hemisphere.

  3. 'Conservation Education' and the Foundations of National Prosperity: Comparative Perspectives from Early Twentieth-Century North America and Britain.

    Science.gov (United States)

    Marsden, William E.

    1998-01-01

    Compares the development of conservation education in North America and Britain. Reports that the focus of British conservation education was on preserving the countryside, while the United States focused on protecting natural resources. Finds that a major difference was that the label of 'conservation education' did not appear in Britain. (CMK)

  4. Current status, distribution, and conservation of the Burrowing Owl (Speotyto cunicularia) in midwestern and western North America

    Science.gov (United States)

    Steven R. Sheffield

    1997-01-01

    The Burrowing Owl (Speotyto cunicularia) inhabits open prairie grassland habitat in the midwestern and western US and Canada. For several years now, numbers of this species in North America have been declining at an alarming rate. Currently, Burrowing Owls are listed as endangered in Canada and threatened in Mexico. In the United States, the...

  5. A dated phylogeny of the palm tribe Chamaedoreeae supports Eocene dispersal between Africa, North and South America

    DEFF Research Database (Denmark)

    Cuenca-Navarro, Argelia; Lange, Conny Bruun Asmussen; Borchsenius, Finn

    2008-01-01

    The palm tribe Chamaedoreeae reaches its higher diversity in Central America, however, its distribution ranges from the north eastern part of Mexico to Bolivia with a disjunction to the Mascarene Islands in the Indian Ocean. The disjunct distribution of Chamaedoreeae is generally considered a res...

  6. 4.4.5S: Genetic interactions of white pines and blister rust in western North America

    Science.gov (United States)

    Bohun B. Kinloch Jr.

    1998-01-01

    A century since its introduction to North America from Europe, white pine blister rust has come to be recognized as one of the catastrophic plant disease epidemics in history. It has yet to stabilize, continuing to spread and intensify. The nine native white pine hosts comprise major timber producers, important watershed protectors, keystone ecological species, and the...

  7. Simulating the impacts of disturbances on forest carbon cycling in North America: processes, data, models, and challenges

    Science.gov (United States)

    Shuguang Liu; Ben Bond-Lamberty; Jeffrey A. Hicke; Rodrigo Vargas; Shuqing Zhao; Jing Chen; Steven L. Edburg; Yueming Hu; Jinxun Liu; A. David McGuire; Jingfeng Xiao; Robert Keane; Wenping Yuan; Jianwu Tang; Yiqi Luo; Christopher Potter; Jennifer Oeding

    2011-01-01

    Forest disturbances greatly alter the carbon cycle at various spatial and temporal scales. It is critical to understand disturbance regimes and their impacts to better quantify regional and global carbon dynamics. This review of the status and major challenges in representing the impacts of disturbances in modeling the carbon dynamics across North America revealed some...

  8. Cryptolepiota, a new sequestrate genus in the Agaricaceae with evidence for adaptive radiation in western North America

    Science.gov (United States)

    Bradley R. Kropp; Steve Albee-Scott; Michael A. Castellano; James M. Trappe

    2012-01-01

    Phylogenetic analyses based on nLSU and ITS sequence data indicate that the sequestrate genus Gigasperma is polyphyletic. Gigasperma cryptica, which is known only from New Zealand, has affinities with the Cortinariaceae whereas G. americanum and two additional undescribed taxa from western North America are...

  9. Tracking population loss in Cornus florida since discovery of Discula destructiva, causal agent of dogwood anthracnose, in eastern North America

    Science.gov (United States)

    William E. Jones; William D. Smith; Daniel B. Twardus

    2012-01-01

    The purpose of this evaluation monitoring project was to document the losses of flowering dogwood, Cornus florida (L.), an important ornamental and wildlife tree that grows across much of Eastern North America. The project was prompted in 2001 by the apparent abundance of flowering dogwoods along roadsides in the Morgantown, WV, area, despite a...

  10. Recent history of large-scale ecosystem disturbances in North America derived from the AVHRR satellite record.

    Science.gov (United States)

    Christopher Potter; Tan Pang-Ning; Vipin Kumar; Chris Kucharik; Steven Klooster; Vanessa Genovese; Warren Cohen; Sean. Healey

    2005-01-01

    Ecosystem structure and function are strongly affected by disturbance events, many of which in North America are associated with seasonal temperature extremes, wildfires, and tropical storms. This study was conducted to evaluate patterns in a 19-year record of global satellite observations of vegetation phenology from the advanced very high resolution radiometer (AVHRR...

  11. 78 FR 56859 - Foreign-Trade Zone 267-Fargo, North Dakota; Authorization of Production Activity; CNH America...

    Science.gov (United States)

    2013-09-16

    ... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-51-2013] Foreign-Trade Zone 267--Fargo, North Dakota; Authorization of Production Activity; CNH America, LLC, (Construction and Agricultural Equipment..., submitted a notification of proposed production activity to the Foreign-Trade Zones (FTZ) Board on behalf of...

  12. Knowledge of Practice: A Multi-sited Event Ethnography of Border Security Fairs in Europe and North America

    NARCIS (Netherlands)

    Baird, T.E.

    2017-01-01

    This article takes the reader inside four border security fairs in Europe and North America to examine the knowledge practices of border security professionals. Building on the border security as practice research agenda, the analysis focuses on the production, circulation, and consumption of scarce

  13. Trends in Surface Water Chemistry in Acidified Areas in Europe and North America from 1990 to 2008

    Science.gov (United States)

    Acidification of lakes and rivers is still an environmental concern despite reduced emissions of acidifying compounds. We analyzed trends in surface water chemistry of 173 acid-sensitive sites from 12 regions in Europe and North America. In 11 of 12 regions, non-marine sulphate (...

  14. Why is Taeniatherum caput-medusae (medusahead) Invasive in North America and not in its Native Eurasia?

    Science.gov (United States)

    Taeniatherum caput-medusae (medusahead) is an exotic annual grass introduced to North America in 1887 that has since invaded an estimated four million ha of rangelands. Contrary, in its native ranges of Eurasia, T. caput-medusae is not considered to be invasive. Why is it that T. caput-medusae expre...

  15. 77 FR 52393 - Petition for Exemption From the Vehicle Theft Prevention Standard; BMW of North America, LLC

    Science.gov (United States)

    2012-08-29

    ... From the Vehicle Theft Prevention Standard; BMW of North America, LLC AGENCY: National Highway Traffic... of the Carline 4 vehicle line in accordance with 49 CFR Part 543, Exemption from the Theft Prevention... vehicle theft as compliance with the parts-marking requirements of the Theft Prevention Standard (49 CFR...

  16. Integrative review of indigenous arthropod natural enemies of the invasive brown marmorated stink bug in North America and Europe

    Science.gov (United States)

    Since the establishment of the brown marmorated stink bug, Halyomorpha halys Stål (Hemiptera: Pentatomidae) in North America and Europe, there has been a large, multi-group effort to characterize the composition and impact of the indigenous community of arthropod natural enemies attacking this invas...

  17. Spanish poster contributions to the Meeting of the Radiological Society of North America (RSNA) between 1988 and 1998

    International Nuclear Information System (INIS)

    Villanueva, A. J.

    1999-01-01

    Following a short historical introduction concerning the attendance of Spanish radiologists at international congresses, we summarize the data provided in poster form obtained from the proceedings of the meetings of the Radiological Society of North America held in 1989, 1992, 1995 and 1998. Suggestions to further this initiative are made. (Author) 6 refs

  18. Spread of butternut canker in North America, host range, evidence of resistance within butternut populations and conservation genetics

    Science.gov (United States)

    M. E. Ostry; K. Woeste

    2004-01-01

    Butternut canker is killing trees throughout the range of butternut in North America and is threatening the viability of many populations in several areas. Although butternut is the primary host, other Juglans species and some hardwood species also are potential hosts. Evidence is building that genetic resistance within butternut populations may be...

  19. Strategies, tools, and challenges for sustaining and restoring high elevation five-needle white pine forests in western North America

    Science.gov (United States)

    Robert E. Keane; Anna W. Schoettle

    2011-01-01

    Many ecologically important, five-needle white pine forests that historically dominated the high elevation landscapes of western North America are now being heavily impacted by mountain pine beetle (Dendroctonus spp.) outbreaks, the exotic disease white pine blister rust (WPBR), and altered high elevation fire regimes. Management intervention using specially designed...

  20. Development and analysis of a 12-year daily 1-km forest fire dataset across North America from NOAA/AVHRR

    Science.gov (United States)

    Ruiliang Pu; Zhanqing Li; Peng Gong; Ivan Csiszar; Robert Fraser; Wei-Min Hao; Shobha Kondragunta; Fuzhong Weng

    2007-01-01

    Fires in boreal and temperate forests play a significant role in the global carbon cycle. While forest fires in North America (NA) have been surveyed extensively by U.S. and Canadian forest services, most fire records are limited to seasonal statistics without information on temporal evolution and spatial expansion. Such dynamic information is crucial for modeling fire...

  1. An ecologically based approach to oak silviculture: a synthesis of 50 years of oak ecosystem research in North America

    Science.gov (United States)

    Daniel C. Dey; Alejandro A. Royo; Patrick H. Brose; Todd F. Hutchinson; Martin A. Spetich; Scott H. Stoleson

    2010-01-01

    Oak (Quercus L.) is an abundant and widely distributed genus in eastern North America. A history of periodic fire, grazing, canopy disturbance and timber harvesting has favored oak's dominance. But, changes in this regime toward much less fire or complete fire suppression, and selective cutting are causing the successional replacement of oak....

  2. LETHALITY OF PSEUDOMONAS FLUORESCENS STRAIN CLO145A TO THE 2 ZEBRA MUSSEL SPECIES PRESENT IN NORTH AMERICA

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2001-10-28

    These experiments indicated that bacterial strain CL0145A of Pseudomonas fluorescens is equally lethal to the 2 zebra mussel species present in North America, Dreissena polymorpha and Dreissena bugensis. Thus, this bacterial strain should be equally effective at killing zebra mussels in power plant pipes, irrespective of which species is present.

  3. Two-Way Communication between Scientists and the Public: A View from Science Communication Trainers in North America

    Science.gov (United States)

    Yuan, Shupei; Oshita, Tsuyoshi; AbiGhannam, Niveen; Dudo, Anthony; Besley, John C.; Koh, Hyeseung E.

    2017-01-01

    The current study explores the degree to which two-way communication is applied in science communication contexts in North America, based on the experiences of science communication trainers. Interviews with 24 science communication trainers suggest that scientists rarely focus on applying two-way communication tactics, such as listening to their…

  4. 76 FR 16447 - Lafarge North America, Inc., a Subsidiary of Lafarge, Including On-Site Leased Workers From...

    Science.gov (United States)

    2011-03-23

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-74,880] Lafarge North America, Inc., a Subsidiary of Lafarge, Including On-Site Leased Workers From Industrial Services, Incorporated and Summit Building Maintenance, Seattle, WA; Amended Certification Regarding Eligibility To Apply for Worker Adjustment Assistance In accordance...

  5. Influence of forest and rangeland management on anadromous fish habitat in Western North America: water transportation and storage of logs.

    Science.gov (United States)

    J.R. Sedell; W.S. Duval

    1985-01-01

    Environmental effects of water transportation of logs in western North America include the historical driving of logs in rivers and streams, and the current dumping, sorting, transportation, and storage of logs in rivers and estuaries in British Columbia and southeastern Alaska. The historical discussion focuses on habitat losses and volumes of...

  6. A meta-analysis of the fire-oak hypothesis: Does prescribed burning promote oak reproduction in eastern North America

    Science.gov (United States)

    Patrick H. Brose; Daniel C. Dey; Ross J. Phillips; Thomas A. Waldrop

    2013-01-01

    The fire-oak hypothesis asserts that the current lack of fire is a reason behind the widespread oak (Quercus spp.) regeneration difficulties of eastern North America, and use of prescribed burning can help solve this problem. We performed a meta-analysis on the data from 32 prescribed fire studies conducted in mixed-oak forests to test whether they...

  7. 78 FR 15718 - Iberdrola Renewables, Inc. PacifiCorp NextEra Energy Resources, LLC Invenergy Wind North America...

    Science.gov (United States)

    2013-03-12

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL11-44-006] Iberdrola Renewables, Inc. PacifiCorp NextEra Energy Resources, LLC Invenergy Wind North America LLC Horizon Wind Energy LLC v. Bonneville Power Administration; Notice of Filing Take notice that on March 1, 2013...

  8. Earliest Human Presence in North America Dated to the Last Glacial Maximum: New Radiocarbon Dates from Bluefish Caves, Canada.

    Science.gov (United States)

    Bourgeon, Lauriane; Burke, Ariane; Higham, Thomas

    2017-01-01

    The timing of the first entry of humans into North America is still hotly debated within the scientific community. Excavations conducted at Bluefish Caves (Yukon Territory) from 1977 to 1987 yielded a series of radiocarbon dates that led archaeologists to propose that the initial dispersal of human groups into Eastern Beringia (Alaska and the Yukon Territory) occurred during the Last Glacial Maximum (LGM). This hypothesis proved highly controversial in the absence of other sites of similar age and concerns about the stratigraphy and anthropogenic signature of the bone assemblages that yielded the dates. The weight of the available archaeological evidence suggests that the first peopling of North America occurred ca. 14,000 cal BP (calibrated years Before Present), i.e., well after the LGM. Here, we report new AMS radiocarbon dates obtained on cut-marked bone samples identified during a comprehensive taphonomic analysis of the Bluefish Caves fauna. Our results demonstrate that humans occupied the site as early as 24,000 cal BP (19,650 ± 130 14C BP). In addition to proving that Bluefish Caves is the oldest known archaeological site in North America, the results offer archaeological support for the "Beringian standstill hypothesis", which proposes that a genetically isolated human population persisted in Beringia during the LGM and dispersed from there to North and South America during the post-LGM period.

  9. Tree growth and climate in the Pacific Northwest, North America: a broad-scale analysis of changing growth environments

    Science.gov (United States)

    Whitney L. Albright; David L. Peterson

    2013-01-01

    Climate change in the 21st century will affect tree growth in the Pacific Northwest region of North America, although complex climate–growth relationships make it difficult to identify how radial growth will respond across different species distributions. We used a novel method to examine potential growth responses to climate change at a broad geographical scale with a...

  10. Hyperparameterization of soil moisture statistical models for North America with Ensemble Learning Models (Elm)

    Science.gov (United States)

    Steinberg, P. D.; Brener, G.; Duffy, D.; Nearing, G. S.; Pelissier, C.

    2017-12-01

    Hyperparameterization, of statistical models, i.e. automated model scoring and selection, such as evolutionary algorithms, grid searches, and randomized searches, can improve forecast model skill by reducing errors associated with model parameterization, model structure, and statistical properties of training data. Ensemble Learning Models (Elm), and the related Earthio package, provide a flexible interface for automating the selection of parameters and model structure for machine learning models common in climate science and land cover classification, offering convenient tools for loading NetCDF, HDF, Grib, or GeoTiff files, decomposition methods like PCA and manifold learning, and parallel training and prediction with unsupervised and supervised classification, clustering, and regression estimators. Continuum Analytics is using Elm to experiment with statistical soil moisture forecasting based on meteorological forcing data from NASA's North American Land Data Assimilation System (NLDAS). There Elm is using the NSGA-2 multiobjective optimization algorithm for optimizing statistical preprocessing of forcing data to improve goodness-of-fit for statistical models (i.e. feature engineering). This presentation will discuss Elm and its components, including dask (distributed task scheduling), xarray (data structures for n-dimensional arrays), and scikit-learn (statistical preprocessing, clustering, classification, regression), and it will show how NSGA-2 is being used for automate selection of soil moisture forecast statistical models for North America.

  11. A virtual climate library of surface temperature over North America for 1979–2015

    Science.gov (United States)

    Kravtsov, Sergey; Roebber, Paul; Brazauskas, Vytaras

    2017-01-01

    The most comprehensive continuous-coverage modern climatic data sets, known as reanalyses, come from combining state-of-the-art numerical weather prediction (NWP) models with diverse available observations. These reanalysis products estimate the path of climate evolution that actually happened, and their use in a probabilistic context—for example, to document trends in extreme events in response to climate change—is, therefore, limited. Free runs of NWP models without data assimilation can in principle be used for the latter purpose, but such simulations are computationally expensive and are prone to systematic biases. Here we produce a high-resolution, 100-member ensemble simulation of surface atmospheric temperature over North America for the 1979–2015 period using a comprehensive spatially extended non-stationary statistical model derived from the data based on the North American Regional Reanalysis. The surrogate climate realizations generated by this model are independent from, yet nearly statistically congruent with reality. This data set provides unique opportunities for the analysis of weather-related risk, with applications in agriculture, energy development, and protection of human life. PMID:29039842

  12. A virtual climate library of surface temperature over North America for 1979-2015

    Science.gov (United States)

    Kravtsov, Sergey; Roebber, Paul; Brazauskas, Vytaras

    2017-10-01

    The most comprehensive continuous-coverage modern climatic data sets, known as reanalyses, come from combining state-of-the-art numerical weather prediction (NWP) models with diverse available observations. These reanalysis products estimate the path of climate evolution that actually happened, and their use in a probabilistic context—for example, to document trends in extreme events in response to climate change—is, therefore, limited. Free runs of NWP models without data assimilation can in principle be used for the latter purpose, but such simulations are computationally expensive and are prone to systematic biases. Here we produce a high-resolution, 100-member ensemble simulation of surface atmospheric temperature over North America for the 1979-2015 period using a comprehensive spatially extended non-stationary statistical model derived from the data based on the North American Regional Reanalysis. The surrogate climate realizations generated by this model are independent from, yet nearly statistically congruent with reality. This data set provides unique opportunities for the analysis of weather-related risk, with applications in agriculture, energy development, and protection of human life.

  13. Potential effects of climate change on aquatic ecosystems of the Great Plains of North America

    Science.gov (United States)

    Covich, A.P.; Fritz, S.C.; Lamb, P.J.; Marzolf, R.D.; Matthews, W.J.; Poiani, K.A.; Prepas, E.E.; Richman, M.B.; Winter, T.C.

    1997-01-01

    The Great Plains landscape is less topographically complex than most other regions within North America, but diverse aquatic ecosystems, such as playas, pothole lakes, ox-bow lakes, springs, groundwater aquifers, intermittent and ephemeral streams, as well as large rivers and wetlands, are highly dynamic and responsive to extreme climatic fluctuations. We review the evidence for climatic change that demonstrates the historical importance of extremes in north-south differences in summer temperatures and east-west differences in aridity across four large subregions. These physical driving forces alter density stratification, deoxygenation, decomposition and salinity. Biotic community composition and associated ecosystem processes of productivity and nutrient cycling respond rapidly to these climatically driven dynamics. Ecosystem processes also respond to cultural effects such as dams and diversions of water for irrigation, waste dilution and urban demands for drinking water and industrial uses. Distinguishing climatic from cultural effects in future models of aquatic ecosystem functioning will require more refinement in both climatic and economic forecasting. There is a need, for example, to predict how long-term climatic forecasts (based on both ENSO and global warming simulations) relate to the permanence and productivity of shallow water ecosystems. Aquatic ecologists, hydrologists, climatologists and geographers have much to discuss regarding the synthesis of available data and the design of future interdisciplinary research. ?? 1997 by John Wiley & Sons, Ltd.

  14. Uranium Mining and Norm in North America-Some Perspectives on Occupational Radiation Exposure.

    Science.gov (United States)

    Brown, Steven H; Chambers, Douglas B

    2017-07-01

    All soils and rocks contain naturally occurring radioactive materials (NORM). Many ores and raw materials contain relatively elevated levels of natural radionuclides, and processing such materials can further increase the concentrations of naturally occurring radionuclides. In the U.S., these materials are sometimes referred to as technologically-enhanced naturally occurring radioactive materials (TENORM). Examples of NORM minerals include uranium ores, monazite (a source of rare earth minerals), and phosphate rock used to produce phosphate fertilizer. The processing of these materials has the potential to result in above-background radiation exposure to workers. Following a brief review of the sources and potential for worker exposure from NORM in these varied industries, this paper will then present an overview of uranium mining and recovery in North America, including discussion on the mining methods currently being used for both conventional (underground, open pit) and in situ leach (ISL), also referred to as In Situ Recovery (ISR), and the production of NORM materials and wastes associated with these uranium recovery methods. The radiological composition of the NORM products and wastes produced and recent data on radiological exposures received by workers in the North American uranium recovery industry are then described. The paper also identifies the responsible government agencies in the U.S. and Canada assigned the authority to regulate and control occupational exposure from these NORM materials.

  15. Historical biogeography sets the foundation for contemporary conservation of martens (genus Martes) in northwestern North America

    Science.gov (United States)

    Dawson, Natalie G.; Colella, Jocelyn P.; Small, Maurine P.; Stone, Karen D.; Talbot, Sandra L.; Cook, Joseph A.

    2017-01-01

    Effective conservation of insular populations requires careful consideration of biogeography, including colonization histories and patterns of endemism. Across the Pacific Northwest of North America, Pacific martens (Martes caurina) and American pine martens (Martes americana) are parapatric sister species with distinctive postglacial histories. Using mitochondrial DNA and 12 nuclear microsatellite loci, we examine processes of island colonization and anthropogenic introductions across 25 populations of martens. Along the North Pacific Coast (NPC), M. caurina is now found on only 2 islands, whereas M. americana occurs on mainland Alaska and British Columbia and multiple associated islands. Island populations of M. caurina have a longer history of isolation reflected in divergent haplotypes, private microsatellite alleles, and relatively low within-population diversity. In contrast, insular M. americanahave lower among-population divergence and higher metrics of within-population diversity. On some NPC islands, introductions of M. americana may be related to decline of M. caurina. Long-term persistence of these species likely has been influenced by anthropogenic manipulations, including wildlife translocations and industrial-scale deforestation, yet, the distinctive histories of these martens have not been incorporated into natural resource policies.

  16. Antigenic Characterization of H3 Subtypes of Avian Influenza A Viruses from North America.

    Science.gov (United States)

    Bailey, Elizabeth; Long, Li-Ping; Zhao, Nan; Hall, Jeffrey S; Baroch, John A; Nolting, Jacqueline; Senter, Lucy; Cunningham, Frederick L; Pharr, G Todd; Hanson, Larry; Slemons, Richard; DeLiberto, Thomas J; Wan, Xiu-Feng

    2016-05-01

    Besides humans, H3 subtypes of influenza A viruses (IAVs) can infect various animal hosts, including avian, swine, equine, canine, and sea mammal species. These H3 viruses are both antigenically and genetically diverse. Here, we characterized the antigenic diversity of contemporary H3 avian IAVs recovered from migratory birds in North America. Hemagglutination inhibition (HI) assays were performed on 37 H3 isolates of avian IAVs recovered from 2007 to 2011 using generated reference chicken sera. These isolates were recovered from samples taken in the Atlantic, Mississippi, Central, and Pacific waterfowl migration flyways. Antisera to all the tested H3 isolates cross-reacted with each other and, to a lesser extent, with those to H3 canine and H3 equine IAVs. Antigenic cartography showed that the largest antigenic distance among the 37 avian IAVs is about four units, and each unit corresponds to a 2 log 2 difference in the HI titer. However, none of the tested H3 IAVs cross-reacted with ferret sera derived from contemporary swine and human IAVs. Our results showed that the H3 avian IAVs we tested lacked significant antigenic diversity, and these viruses were antigenically different from those circulating in swine and human populations. This suggests that H3 avian IAVs in North American waterfowl are antigenically relatively stable.

  17. Decadal Drought and Wetness Reconstructed for Subtropical North America in the Mexican Drought Atlas

    Science.gov (United States)

    Burnette, D. J.; Stahle, D. W.; Cook, E. R.; Villanueva Diaz, J.; Griffin, D.; Cook, B.

    2014-12-01

    A new drought atlas has been developed for subtropical North America, including the entire Republic of Mexico. This Mexican Drought Atlas (MXDA) is based on 251 tree-ring chronologies, including 82 from Mexico and another 169 from the southern U.S. and western Guatemala. Point-by-point principal components regression was used to reconstruct the self-calibrating Palmer Drought Severity Index (PDSI) for June-August. Calibration and verification statistics were improved over what was previously possible with the North American Drought Atlas, which was based on fewer chronologies only in Mexico. The MXDA will be served on the web with analytical tools for composite, correlation, and congruence analyses. The new PDSI reconstructions provide a more detailed estimation of decadal moisture regimes over the past 2000 years, but are most robust after 1400 AD, when several chronologies are available across Mexico. Droughts previously identified in a subset of chronologies are confirmed and their spatial impact quantified in the new reconstructions. This includes the intense drought of the mid-15th Century described in Aztec legend, the 16th Century megadrought, and "El Año del Hambre", one of the worst famines in Mexican history. We also use the best replicated portion of the MXDA in the 18th and 19th Centuries to reconstruct moisture anomalies during key time periods of Mexican turmoil (e.g., the Mexican War of Independence).

  18. The management of ductal carcinoma in situ in North America and Europe. Results of a survey.

    Science.gov (United States)

    Ceilley, Elizabeth; Jagsi, Reshma; Goldberg, Saveli; Kachnic, Lisa; Powell, Simon; Taghian, Alphonse

    2004-11-01

    The goal of the current study was to understand and document contemporary treatment approaches in the management of ductal carcinoma in situ (DCIS). An original questionnaire was designed to assess radiation oncologists' management of breast carcinoma, including 26 questions specifically addressing DCIS. A postal survey was conducted of members of the American and European Societies of Therapeutic Radiology and Oncology. The results of 702 responses from North America were compared with 435 responses from Europe, to determine treatment recommendations and variability by type of institution and geographic region. There were strong correlations between the grade of DCIS and/or the margin status and the use of radiotherapy (RT; P variations in physician recommendations for tamoxifen (P < 0.001), but not in the tendency to recommend RT. North American academic physicians were less likely to recommend RT for favorable DCIS than nonacademic physicians (P < 0.01). There were marked differences in physician opinions regarding the management of DCIS, with significant international differences in patterns of care. The survey quantified and highlighted areas of agreement and controversy regarding the use of RT and tamoxifen in the management of DCIS. It provided support for large international trials to evaluate the optimal management of DCIS in the areas identified as most controversial.

  19. Correcting surface solar radiation of two data assimilation systems against FLUXNET observations in North America

    Science.gov (United States)

    Zhao, Lei; Lee, Xuhui; Liu, Shoudong

    2013-09-01

    Solar radiation at the Earth's surface is an important driver of meteorological and ecological processes. The objective of this study is to evaluate the accuracy of the reanalysis solar radiation produced by NARR (North American Regional Reanalysis) and MERRA (Modern-Era Retrospective Analysis for Research and Applications) against the FLUXNET measurements in North America. We found that both assimilation systems systematically overestimated the surface solar radiation flux on the monthly and annual scale, with an average bias error of +37.2 Wm-2 for NARR and of +20.2 Wm-2 for MERRA. The bias errors were larger under cloudy skies than under clear skies. A postreanalysis algorithm consisting of empirical relationships between model bias, a clearness index, and site elevation was proposed to correct the model errors. Results show that the algorithm can remove the systematic bias errors for both FLUXNET calibration sites (sites used to establish the algorithm) and independent validation sites. After correction, the average annual mean bias errors were reduced to +1.3 Wm-2 for NARR and +2.7 Wm-2 for MERRA. Applying the correction algorithm to the global domain of MERRA brought the global mean surface incoming shortwave radiation down by 17.3 W m-2 to 175.5 W m-2. Under the constraint of the energy balance, other radiation and energy balance terms at the Earth's surface, estimated from independent global data products, also support the need for a downward adjustment of the MERRA surface solar radiation.

  20. International market integration for natural gas? A cointegration analysis of prices in Europe, North America and Japan

    International Nuclear Information System (INIS)

    Siliverstovs, Boriss; L'Hegaret, Guillaume; Neumann, Anne; Hirschlausen, Christian von

    2005-01-01

    This paper investigates the degree of integration of natural gas markets in Europe, North America and Japan in the time period between the early 1990s and 2004. The relationship between international gas market prices and their relation to the oil price are explored through principal components analysis and Johansen likelihood-based cointegration procedure. Both of them show a high level of natural gas market integration within Europe, between the European and Japanese markets as well as within the North American market. At the same time the obtained results suggest that the European (respectively, Japanese) and the North American markets were not integrated. (Author)

  1. MECO Warming Changes Continental Rainfall Patterns in Eocene Western North America

    Science.gov (United States)

    Methner, K.; Mulch, A.; Fiebig, J.; Wacker, U.; Gerdes, A.; Graham, S. A.; Chamberlain, C. P.

    2016-12-01

    Eocene hyperthermals represent temperature extremes superimposed on an existing warm climate. They dramatically affected the marine and terrestrial biosphere, but still remain among the most enigmatic phenomena of Cenozoic climate dynamics. To evaluate the impacts of global warm periods on terrestrial temperature and rainfall records in continental interiors, we sampled a suite of middle Eocene ( 40 Ma) paleosols from a high-elevation mammal fossil locality in the hinterland of the North American Cordillera (Sage Creek Basin, Montana, USA) and integrated laser ablation U-Pb dating of pedogenic carbonate, stable isotope (δ18O) and clumped isotope temperature (Δ47) records. Δ47 temperature data of soil carbonates progressively increase from 23 °C ±3 °C to peak temperatures of 32 °C ±3 °C and subsequently drop to 21 °C ±2 °C and delineate a rapid +9/-11 °C temperature excursion in the paleosol record. This hyperthermal event is accompanied by large and rapid shifts towards low δ18O values and reduced pedogenic CaCO3 contents. U-Pb geochronology of the paleosol carbonate confirms a middle Eocene age for soil carbonate formation (39.5 ±1.4 Ma and 40.1 ±0.8 Ma). Based on U-Pb geochronology, magneto- and biostratigraphy we suggest that the recorded Δ47 temperature excursion reflects peak warming during the Middle Eocene Climatic Optimum (MECO). The MECO in continental western North America appears to be characterized by warmer and wetter (sub-humid) conditions in this high-elevation site. Shifts in δ18O values of precipitation and pedogenic CaCO3 contents parallel temperature changes and require modification of mid-latitude rainfall patterns, indicating a profound impact of the MECO on the hydrological cycle and consequently on atmospheric circulation patterns in the hinterland of the North American Cordillera.

  2. Vulnerability of high-latitude soil organic carbon in North America to disturbance

    Science.gov (United States)

    Grosse, Guido; Harden, Jennifer W.; Turetsky, Merritt; McGuire, A. David; Camill, Philip; Tarnocai, Charles; Frolking, Steve; Schuur, Edward A.G.; Jorgenson, Torre; Marchenko, Sergei; Romanovsky, Vladimir; Wickland, Kimberly P.; French, Nancy; Waldrop, Mark P.; Bourgeau-Chavez, Laura L.; Striegl, Robert G.

    2011-01-01

    This synthesis addresses the vulnerability of the North American high-latitude soil organic carbon (SOC) pool to climate change. Disturbances caused by climate warming in arctic, subarctic, and boreal environments can result in significant redistribution of C among major reservoirs with potential global impacts. We divide the current northern high-latitude SOC pools into (1) near-surface soils where SOC is affected by seasonal freeze-thaw processes and changes in moisture status, and (2) deeper permafrost and peatland strata down to several tens of meters depth where SOC is usually not affected by short-term changes. We address key factors (permafrost, vegetation, hydrology, paleoenvironmental history) and processes (C input, storage, decomposition, and output) responsible for the formation of the large high-latitude SOC pool in North America and highlight how climate-related disturbances could alter this pool's character and size. Press disturbances of relatively slow but persistent nature such as top-down thawing of permafrost, and changes in hydrology, microbiological communities, pedological processes, and vegetation types, as well as pulse disturbances of relatively rapid and local nature such as wildfires and thermokarst, could substantially impact SOC stocks. Ongoing climate warming in the North American high-latitude region could result in crossing environmental thresholds, thereby accelerating press disturbances and increasingly triggering pulse disturbances and eventually affecting the C source/sink net character of northern high-latitude soils. Finally, we assess postdisturbance feedbacks, models, and predictions for the northern high-latitude SOC pool, and discuss data and research gaps to be addressed by future research.

  3. Regional-Scale Declines in Productivity of Pink and Chum Salmon Stocks in Western North America

    Science.gov (United States)

    Malick, Michael J.; Cox, Sean P.

    2016-01-01

    Sockeye salmon (Oncorhynchus nerka) stocks throughout the southern part of their North American range have experienced declines in productivity over the past two decades. In this study, we tested the hypothesis that pink (O. gorbuscha) and chum (O. keta) salmon stocks have also experienced recent declines in productivity by investigating temporal and spatial trends in productivity of 99 wild North American pink and chum salmon stocks. We used a combination of population dynamics and time series models to quantify individual stock trends as well as common temporal trends in pink and chum salmon productivity across local, regional, and continental spatial scales. Our results indicated widespread declines in productivity of wild chum salmon stocks throughout Washington (WA) and British Columbia (BC) with 81% of stocks showing recent declines in productivity, although the exact form of the trends varied among regions. For pink salmon, the majority of stocks in WA and BC (65%) did not have strong temporal trends in productivity; however, all stocks that did have trends in productivity showed declining productivity since at least brood year 1996. We found weaker evidence of widespread declines in productivity for Alaska pink and chum salmon, with some regions and stocks showing declines in productivity (e.g., Kodiak chum salmon stocks) and others showing increases (e.g., Alaska Peninsula pink salmon stocks). We also found strong positive covariation between stock productivity series at the regional spatial scale for both pink and chum salmon, along with evidence that this regional-scale positive covariation has become stronger since the early 1990s in WA and BC. In general, our results suggest that common processes operating at the regional or multi-regional spatial scales drive productivity of pink and chum salmon stocks in western North America and that the effects of these process on productivity may change over time. PMID:26760510

  4. Why Don’t They Participate? A Self-Study of Chinese Graduate Students’ Classroom:Involvement in North America

    Directory of Open Access Journals (Sweden)

    Chunlei Lu

    2010-07-01

    Full Text Available China is now the world’s largest source of international students. In terms of learning performance, Chinese graduate students studying in North America exhibit distinct differences from students who are born and raised in North America. Conflicting cultural values compel Chinese students to reconcile East-West cultures, and put an onus on North American instructors to implement culturally-sensitive pedagogy. Employing the theoretic framework of yin-yang theory, this paper examines Chinese graduate students’ classroom performance against the backdrop of East-West cultural negotiation, and specifically seeks to identify which factors inhibit Chinese graduate students’ participation in North American classrooms. Drawing from their own living experiences, the authors employ self-study in the methodological form of narrative inquiry – in conjunction with references from existing literature – to investigate Chinese graduates’ classroom challenges. Results reveal six factors impacting students’ classroom performance: language; knowledge of the education system; knowledge of the social system; personality; influence of traditional culture; and social/economic/political changes. Future research directions are also suggested.Key words: Chinese graduates, East-West, cross-culture, North America, classroom involvement, self-study 

  5. CMS (Carbon Monitoring System) Methane (CH4) Flux for North America 0.5 degree x 0.667 degree V1 (CMS_CH4_FLX_NA) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — The CMS Methane (CH4) Flux for North America data set contains estimates of methane emission in North America based on an inversion of the GEOS-Chem chemical...

  6. Development of a Remote-Sensing Based Framework for Mapping Drought over North America

    Science.gov (United States)

    Hain, C.; Anderson, M. C.; Zhan, X.; Gao, F.; Svoboda, M.; Wardlow, B.; Mladenova, I. E.

    2012-12-01

    This presentation will address the development of a multi-scale drought monitoring tool for North America based on remotely sensed estimates of evapotranspiration. The North American continent represents a broad range in vegetation and climate conditions, from the boreal forests in Canada to the arid deserts in Mexico. This domain also encompasses a range in constraints limiting vegetation growth, with a gradient from radiation/energy limitation in the north to moisture limits in the south. This feasibility study over NA will provide a valuable test bed for future implementation world-wide in support of proposed global drought monitoring and early warning efforts. The Evaporative Stress Index (ESI) represents anomalies in the ratio of actual-to-potential ET (fPET), generated with the thermal remote sensing based Atmosphere-Land Exchange Inverse (ALEXI) surface energy balance model and associated disaggregation algorithm, DisALEXI demonstrated that ESI maps over the continental US (CONUS) show good correspondence with standard drought metrics and with patterns of antecedent precipitation, but can be generated at significantly higher spatial resolution due to a limited reliance on ground observations. Unique behavior is observed in the ESI in regions where the evaporative flux is enhanced by moisture sources decoupled from local rainfall, for example in areas where drought impacts are being mitigated by intense irrigation or shallow water tables. As such, the ESI is a measure of actual stress rather than potential for stress, and has physical relevance to projected crop development. Because precipitation is not used in construction of the ESI, this index provides an independent assessment of drought conditions and will have particular utility for real-time monitoring in regions with sparse rainfall data or significant delays in meteorological reporting. The North American ESI product will be quantitatively compared with spatiotemporal patterns in the NADM, and with

  7. Projected changes to rain-on-snow events over North America

    Science.gov (United States)

    Jeong, Dae Il; Sushama, Laxmi

    2016-04-01

    Rain-on-snow (ROS) events have significant impacts on cold region ecosystems and water-related natural hazards, and therefore it is very important to assess how this hydro-meteorological phenomenon will evolve in a changing climate. This study evaluates the changes in ROS characteristics (i.e., frequency, amounts, and runoff) for the future 2041-2070 period with respect to the current 1976-2005 period over North America using six simulations, based on two Canadian RCMs, driven by two driving GCMs for RCP4.5 and 8.5 emission pathways. Projected changes to extreme runoff caused by the changes of the ROS characteristics are also evaluated. All simulations suggest general increases in ROS days in late autumn, winter, and early spring periods for most Canadian regions and northwestern USA for the future period, due to an increase in rain days in a warmer climate. Increases in the future ROS amounts are projected mainly due to an increase in ROS days, although increases in precipitation intensity also contributes to the future increases. Future ROS runoff is expected to increase more than future ROS amounts during snowmelt months as ROS events usually enhance runoff, given the land state and asociated reduced soil infiltration rate and also due to the faster snowmelt rate occuring during these events. The simulations also show that ROS events usually lead to extreme runoff over most of Canada and north-western and -central USA in the January-May snowmelt months for the current period and these show no significant changes in the future climate. However, the future ROS to total runoff ratio will significantly decrease for western and eastern Canada as well as north-western USA for these months, due to an overall increase of the fraction of direct snowmelt and rainfall generated runoff in a warmer climate. These results indicate the difficulties of flood risk and water resource managements in the future, particularly in Canada and north-western and -central USA, requiring

  8. Biography of a technology: North America's power grid through the twentieth century

    Science.gov (United States)

    Cohn, Julie A.

    conservation. While this project explores the history of how and why North America has a huge interconnected power system, it also offers insights into the challenges the grid poses for our energy future.

  9. Two new genera of metalmark butterflies of North and Central America (Lepidoptera, Riodinidae

    Directory of Open Access Journals (Sweden)

    Marysol Trujano-Ortega

    2018-01-01

    Full Text Available Two new genera of Riodinidae (Insecta: Lepidoptera are described, Neoapodemia Trujano-Ortega, gen. n. (Neoapodemia nais (W. H. Edwards, 1876, comb. n., N. chisosensis Freeman, 1964, comb. n. and Plesioarida Trujano-Ortega & García-Vázquez, gen. n. (Plesioarida palmerii palmerii (W. H. Edwards, 1870, comb. n., P. palmerii arizona (Austin, [1989], comb. n., P. palmerii australis (Austin, [1989], comb. n., P. hepburni hepburni (Godman & Salvin, 1886, comb. n., P. hepburni remota (Austin, 1991, comb. n., P. murphyi (Austin, [1989], comb. n., P. hypoglauca hypoglauca (Godman & Salvin, 1878, comb. n., P. hypoglauca wellingi (Ferris, 1985, comb. n., P. walkeri (Godman & Salvin, 1886, comb. n., P. selvatica (De la Maza & De la Maza, 2017, comb. n.. Neoapodemia Trujano-Ortega, gen. n. is distributed in the southwestern USA and northeastern Mexico, while Plesioarida Trujano-Ortega & García-Vázquez, gen. n. is present from the southern USA to Central America. Species of these genera were previously classified as Apodemia C. Felder & R. Felder but molecular and morphological evidence separate them as new taxa. Morphological diagnoses and descriptions are provided for both new genera, including the main distinctive characters from labial palpi, prothoracic legs, wing venation and genitalia, as well as life history traits. A molecular phylogeny of one mitochondrial gene (COI and two nuclear genes (EF-1a and wg are also presented of most species of Apodemia, Neoapodemia Trujano-Ortega, gen. n., Plesioarida Trujano-Ortega & García-Vázquez, gen. n., and sequences of specimens from all tribes of Riodinidae. We compare the characters of Apodemia, Neoapodemia Trujano-Ortega, gen. n. and Plesioarida Trujano-Ortega & García-Vázquez, gen. n. and discuss the differences that support the description of these new taxa. This is a contribution to the taxonomy of the Riodinidae of North America of which the generic diversity is greater than previously recognized.

  10. Knowledge gained from analyzing mercury speciation data monitored in North America

    Science.gov (United States)

    Zhang, L.; Cheng, I.; Gay, D. A.; Xu, X.; Wu, Z.

    2017-12-01

    This presentation summarizes knowledge gained in several recent studies through analysis and application of mercury (Hg) speciation data monitored in North America. Annual Hg dry deposition to vegetated surfaces in the rural or remote environment in North America was dominated by leaf uptake of gaseous elemental mercury (GEM), contrary to what was commonly assumed in earlier studies which frequently omitted GEM dry deposition as an important process (Zhang et al., EST, 2016). Dry deposition exceeded wet deposition by a large margin in all of the seasons except in the summer at the majority of the sites. Based on the gaseous oxidized mercury (GOM) concentrations predicted from measured Hg wet deposition using a scavenging ratio method, multi-year average GOM concentrations collected using Tekran speciation instrument were likely biased low by a factor of 2 at about half of the studied sites (Cheng and Zhang, EST, 2017). A decline in the number of source regions impacting ambient GEM and GOM was found from 2005-2014 at an eastern U.S. site through concentration-weighted trajectory (CWT) analysis (Cheng et al., JAS, 2017). Source contributions decreased by up to 20% for GEM, greater than 60% for GOM, and 20-60% for PBM in 2011-2014 than in 2006-2008, largely due to power plant Hg emission reductions since 2009. A study comparing Positive Matrix Factorization (PMF) and Principal Components Analysis (PCA) receptor methods identified similar sources impacting Kejimkujik National Park, Canada, including combustion, industrial sulfur, photochemistry and re-emissions, and oceanic sea-salt emissions. Improving the quality of the Hg data used in receptor methods by imputation did not improve the PMF results, but reducing the fraction of below detection limit data was effective (Xu et al., ACP, 2017). PCA results using reactive mercury (RM=GOM+PBM) or excluding low GOM values were similar to those using the original data. Source contributions from CWT analysis were more

  11. Dynamically downscaled climate simulations over North America: Methods, evaluation, and supporting documentation for users

    Science.gov (United States)

    Hostetler, S.W.; Alder, J.R.; Allan, A.M.

    2011-01-01

    We have completed an array of high-resolution simulations of present and future climate over Western North America (WNA) and Eastern North America (ENA) by dynamically downscaling global climate simulations using a regional climate model, RegCM3. The simulations are intended to provide long time series of internally consistent surface and atmospheric variables for use in climate-related research. In addition to providing high-resolution weather and climate data for the past, present, and future, we have developed an integrated data flow and methodology for processing, summarizing, viewing, and delivering the climate datasets to a wide range of potential users. Our simulations were run over 50- and 15-kilometer model grids in an attempt to capture more of the climatic detail associated with processes such as topographic forcing than can be captured by general circulation models (GCMs). The simulations were run using output from four GCMs. All simulations span the present (for example, 1968-1999), common periods of the future (2040-2069), and two simulations continuously cover 2010-2099. The trace gas concentrations in our simulations were the same as those of the GCMs: the IPCC 20th century time series for 1968-1999 and the A2 time series for simulations of the future. We demonstrate that RegCM3 is capable of producing present day annual and seasonal climatologies of air temperature and precipitation that are in good agreement with observations. Important features of the high-resolution climatology of temperature, precipitation, snow water equivalent (SWE), and soil moisture are consistently reproduced in all model runs over WNA and ENA. The simulations provide a potential range of future climate change for selected decades and display common patterns of the direction and magnitude of changes. As expected, there are some model to model differences that limit interpretability and give rise to uncertainties. Here, we provide background information about the GCMs and

  12. NAOMI: The trials and tribulations of implementing a heroin assisted treatment study in North America

    Directory of Open Access Journals (Sweden)

    Laliberté Nancy

    2009-01-01

    Full Text Available Abstract Background Opioid addiction is a chronic, relapsing disease and remains a major public health challenge. Despite important expansions of access to conventional treatments, there are still significant proportions of affected individuals who remain outside the reach of the current treatment system and who contribute disproportionately to health care and criminal justice costs as well as to public disorder associated with drug addiction. The NAOMI study is a Phase III randomized clinical trial comparing injectable heroin maintenance to oral methadone. The study has ethics board approval at its Montréal and Vancouver sites, as well as from the University of Toronto, the New York Academy of Medicine and Johns Hopkins University. The main objective of the NAOMI Study is to determine whether the closely supervised provision of injectable, pharmaceutical-grade opioid agonist is more effective than methadone alone in recruiting, retaining, and benefiting chronic, opioid-dependent, injection drug users who are resistant to current standard treatment options. Methods The case study submitted chronicles the challenges of getting a heroin assisted treatment trial up and running in North America. It describes: a brief background on opioid addiction; current standard therapies for opioid addiction; why there is/was a need for a heroin assisted treatment trial; a description of heroin assisted treatment; the beginnings of creating the NAOMI study in North America; what is the NAOMI study; the science and politics of the NAOMI study; getting NAOMI started in Canada; various requirements and restrictions in getting the study up and running; recruitment into the study; working with the media; a status report on the study; and a brief conclusion from the authors' perspectives. Results and conclusion As this is a case study, there are no specific results or main findings listed. The case study focuses on: the background of the study; what it took to get

  13. The Role of Precipitation Recycling in the Propagation and Intensification of Droughts in North America

    Science.gov (United States)

    Herrera-Estrada, J. E.; Sheffield, J.; Martinez-Agudelo, J. A.; Dominguez, F.; Wood, E. F.

    2017-12-01

    Predicting droughts allows stakeholders to mitigate some of the negative impacts of these natural disasters. However, there are still large gaps of knowledge regarding the physical drivers of drought onset, development, and recovery. These gaps have limited our ability to predict some important droughts and to understand how they may be affected by climate change. One physical mechanism that has been linked to the evolution of droughts is precipitation recycling, but its role has not been quantified in detail. Here we use a precipitation recycling model that backtracks the spatial origins of precipitation using vertically integrated moisture fluxes and evapotranspiration data. This allows us to estimate the climatology of moisture sources and sinks, and identify from where moisture fails to arrive when a given region experiences a drought. ERA-Interim data is used to drive this precipitation recycling model from 1980 to 2016 throughout North America and its surrounding oceans. The climatological analysis shows that oceans contribute around 80% of the precipitation over North America during winter, while precipitation that originates from evapotranspiration over land reaches a relative contribution of 60% in the summer. Precipitation contributions from the Pacific Ocean were found to be significantly and positively correlated with ENSO and PDO indices. Furthermore, a regression analysis showed that dry soil moisture in the US Southwest reduces moisture exports to the US Midwest, which in turn can dry soil moisture in the US Midwest. Given that up to 13% of precipitation over the US Midwest was found to be locally recycled, there is a multiplier effect whereby a 10 mm/month reduction in precipitation imports into the region leads to an additional decrease of 0.8 mm/month (on average) from reduced local precipitation recycling, causing a drought to intensify. It was also found that during extensive droughts (e.g. 2011 in Texas and 2012 in the US Midwest

  14. Composite study of aerosol export events from East Asia and North America

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    Y. Luan

    2013-02-01

    Full Text Available We use satellite observations of aerosol optical depth (AOD from the Moderate Resolution Imaging Spectrometer (MODIS together with the GEOS-Chem global chemical transport model to contrast export of aerosols from East Asia and North America during 2004–2010. The GEOS-Chem model reproduces the spatial distribution and temporal variations of Asian aerosol outflow generally well, although a low bias (−30% is found in the model fine mode AOD, particularly during summer. We use the model to identify 244 aerosol pollution export events from E. Asia and 251 export events from N. America over our 7-year study period. When these events are composited by season, we find that the AOD in the outflow is enhanced by 50–100% relative to seasonal mean values. The composite Asian plume splits into one branch going poleward to the Arctic in 3–4 days, with the other crossing the Pacific Ocean in 6–8 days. A fraction of the aerosols is trapped in the subtropical Pacific High during spring and summer. The N. American plume travels to the northeast Atlantic, reaching Europe after 4–5 days. Part of the composite plume turns anticyclonically in the Azores High, where it slowly decays. Both the Asian and N. American export events are favored by a dipole structure in sea-level pressure anomalies, associated with mid-latitude cyclone activity over the respective source regions. This dipole structure during outflow events is a strong feature for all seasons except summer, when convection becomes more important. The observed AOD in the E. Asian outflow exhibits stronger seasonality, with a spring maximum, than the N. American outflow, with a broad spring/summer maximum. The large spring AOD in the Asian outflow is the result of enhanced sulfate and dust aerosol concentrations, but is also due to a larger export efficiency of sulfate and SO2 from the Asian boundary layer relative to the N. American boundary layer. While the N. American sulfate outflow

  15. Ocean deformation processes at the Caribbean-North America-South America triple junction: Initial results of the 2007 ANTIPLAC marine survey

    Science.gov (United States)

    Benard, F.; Deville, E.; Le Drezen, E.; Loubrieu, B.; Maltese, L.; Patriat, M.; Roest, W.; Thereau, E.; Umber, M.; Vially, R.

    2007-12-01

    Marine geophysical data (multibeam and seismic lines) acquired in 2007 (ANTIPLAC survey) in the North-South Americas-Caribbean triple point (Central Atlantic, Barracuda and Tiburon ridges area), provide information about the structure, the tectonic processes and the timing of the deformation in this large diffuse zone of polyphase deformation. The deformation of the plate boundary between the north and south Americas is distributed on several structures located in the Atlantic plain, at the front of the Barbados accretionary prism. In this area of deformation of the Atlantic oceanic lithosphere, the main depressions and transform troughs are filled by Late Pliocene-Pleistocene turbidite sediments, especially in the Barracuda trough, north of Barracuda ridge. These sediments are not issued from the Lesser Antilles volcanic arc but they are sourced from the East, probably by the Orinoco turbidite distal system, through channels transiting in the Atlantic abyssal plain. These Late Pliocene- Quaternary sediments show locally spectacular evidences of syntectonic deformation. It can be shown notably that Barracuda ridge includes a pre-existing transform fault system which has been folded and uplifted very recently during Pleistocene times. This recent deformation has generate relieves up to 2 km high with associated erosion processes notably along the northern flank the Barracuda ridge. The subduction of these recently deformed ridges induces deformation of earlier structures within the Barbados accretionary prism. These asperities within the Atlantic oceanic lithosphere which is subducted in the Lesser Antilles active margin are correlated with the zone of intense seismic activity below the volcanic arc.

  16. The impacts of Cenozoic climate and habitat changes on small mammal diversity of North America

    Science.gov (United States)

    Samuels, Joshua X.; Hopkins, Samantha S. B.

    2017-02-01

    Through the Cenozoic, paleoclimate records show general trends of global cooling and increased aridity, and environments in North America shifted from predominantly forests to more open habitats. Paleobotanical records indicate grasses were present on the continent in the Eocene; however, paleosol and phytolith studies indicate that open habitats did not arise until the late Eocene or even later in the Oligocene. Studies of large mammalian herbivores have documented changes in ecomorphology and community structure through time, revealing that shifts in mammalian morphology occurred millions of years after the environmental changes thought to have triggered them. Smaller mammals, like rodents and lagomorphs, should more closely track climate and habitat changes due to their shorter generation times and smaller ranges, but these animals have received much less study. To examine changes in smaller mammals through time, we have assembled and analyzed an ecomorphological database of all North American rodent and lagomorph species. Analyses of these data found that rodent and lagomorph community structure changed dramatically through the Cenozoic, and shifts in diversity and ecology correspond closely with the timing of habitat changes. Cenozoic rodent and lagomorph species diversity is strongly biased by sampling of localities, but sampling-corrected diversity reveals diversity dynamics that, after an initial density-dependent diversification in the Eocene, track habitat changes and the appearance of new ecological adaptations. As habitats became more open and arid through time, rodent and lagomorph crown heights increased while burrowing, jumping, and cursorial adaptations became more prevalent. Through time, open-habitat specialists were added during periods of diversification, while closed-habitat taxa were disproportionately lost in subsequent diversity declines. While shifts among rodents and lagomorphs parallel changes in ungulate communities, they started

  17. Mapping the expansion of coyotes (Canis latrans across North and Central America

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    James W. Hody

    2018-05-01

    Full Text Available The geographic distribution of coyotes (Canis latrans has dramatically expanded since 1900, spreading across much of North America in a period when most other mammal species have been declining. Although this considerable expansion has been well documented at the state/provincial scale, continent-wide descriptions of coyote spread have portrayed conflicting distributions for coyotes prior to the 1900s, with popularly referenced anecdotal accounts showing them restricted to the great plains, and more obscure, but data-rich accounts suggesting they ranged across the arid west. To provide a scientifically credible map of the coyote’s historical range (10,000–300 BP and describe their range expansion from 1900 to 2016, we synthesized archaeological and fossil records, museum specimens, peer-reviewed reports, and records from wildlife management agencies. Museum specimens confirm that coyotes have been present in the arid west and California throughout the Holocene, well before European colonization. Their range in the late 1800s was undistinguishable from earlier periods, and matched the distribution of non-forest habitat in the region. Coyote expansion began around 1900 as they moved north into taiga forests, east into deciduous forests, west into costal temperate rain forests, and south into tropical rainforests. Forest fragmentation and the extirpation of larger predators probably enabled these expansions. In addition, hybridization with wolves (C. lupus, C. lycaon, and/or C. rufus and/or domestic dogs has been documented in the east, and suspected in the south. Our detailed account of the original range of coyotes and their subsequent expansion provides the core description of a large scale ecological experiment that can help us better understand the predator-prey interactions, as well as evolution through hybridization.

  18. Chemical and biological impacts of ocean acidification along the west coast of North America

    Science.gov (United States)

    Feely, Richard A.; Alin, Simone R.; Carter, Brendan; Bednaršek, Nina; Hales, Burke; Chan, Francis; Hill, Tessa M.; Gaylord, Brian; Sanford, Eric; Byrne, Robert H.; Sabine, Christopher L.; Greeley, Dana; Juranek, Lauren

    2016-12-01

    The continental shelf region off the west coast of North America is seasonally exposed to water with a low aragonite saturation state by coastal upwelling of CO2-rich waters. To date, the spatial and temporal distribution of anthropogenic CO2 (Canth) within the CO2-rich waters is largely unknown. Here we adapt the multiple linear regression approach to utilize the GO-SHIP Repeat Hydrography data from the northeast Pacific to establish an annually updated relationship between Canth and potential density. This relationship was then used with the NOAA Ocean Acidification Program West Coast Ocean Acidification (WCOA) cruise data sets from 2007, 2011, 2012, and 2013 to determine the spatial variations of Canth in the upwelled water. Our results show large spatial differences in Canth in surface waters along the coast, with the lowest values (37-55 μmol kg-1) in strong upwelling regions off southern Oregon and northern California and higher values (51-63 μmol kg-1) to the north and south of this region. Coastal dissolved inorganic carbon concentrations are also elevated due to a natural remineralized component (Cbio), which represents carbon accumulated through net respiration in the seawater that has not yet degassed to the atmosphere. Average surface Canth is almost twice the surface remineralized component. In contrast, Canth is only about one third and one fifth of the remineralized component at 50 m and 100 m depth, respectively. Uptake of Canth has caused the aragonite saturation horizon to shoal by approximately 30-50 m since the preindustrial period so that undersaturated waters are well within the regions of the continental shelf that affect the shell dissolution of living pteropods. Our data show that the most severe biological impacts occur in the nearshore waters, where corrosive waters are closest to the surface. Since the pre-industrial times, pteropod shell dissolution has, on average, increased approximately 19-26% in both nearshore and offshore waters.

  19. Geophysical constraints on the mantle structure of the Canadian Cordillera and North America Craton

    Science.gov (United States)

    Yu, T. C.; Currie, C. A.; Unsworth, M. J.

    2017-12-01

    In western Canada, geophysical data indicate that there is a pronounced contrast in mantle structure between the Canadian Cordillera (CC) and North America craton (NAC). The CC is characterized by lower mantle seismic velocity, higher surface heat flow, lower mantle electrical resistivity and lower effective elastic thickness. These observations are consistent with two distinct thermal regimes: the CC has hot and thin lithosphere, while the NAC lithosphere is cool and thick. The boundary between the CC and NAC coincides with the south-north trending Rocky Mountain Trench - Tintina Fault system. Earlier studies have hypothesized that the thin CC lithosphere is maintained by small-scale convection of hydrated mantle, whereas the NAC lithosphere is dry and resistant to thinning. Here, we test this hypothesis through a detailed examination of two independent data sets: (1) seismic shear-wave (Vs) tomography models and (2) magnetotelluric (MT) measurements of mantle electrical resistivity. We analyze tomography model NA07 at 50-250 km depth and create a mapping of Vs to temperature based on mantle composition (via Perple_X) and a correction for anelasticity. For the CC, the calculated temperature is relatively insensitive to mantle composition but strongly depends on the water content and anelastic correction. With a laboratory-based correction, the estimated temperature is 1150 °C at 100 km depth for wet mantle, compared to 1310 °C for dry mantle; no melt is predicted in either case. An empirical anelastic correction predicts a 115 °C hotter mantle and likely some melt. In contrast, composition is the main control on the calculated temperature for the NAC, especially at depths electrical resistivity is sensitive to mantle temperature and hydration.

  20. Moving from a regional to a continental perspective of Phragmites australis invasion in North America

    Science.gov (United States)

    Kettenring, Karin M.; de Blois, Sylvie; Hauber, Donald P.

    2012-01-01

    Aims We use a regional comparison of Phragmites australis (common reed) subsp. americanus, P. australis subsp. berlandieri and introduced P. australis (possibly five sublineages) in the Chesapeake Bay, the St Lawrence River, Utah and the Gulf Coast to inform a North American perspective on P. australis invasion patterns, drivers, impacts and research needs. Findings and research needs Our regional assessments reveal substantial diversity within and between the three main lineages of P. australis in terms of mode of reproduction and the types of environment occupied. For introduced P. australis, the timing of introduction also differed between the regions. Nevertheless, a common finding in these regions reinforces the notion that introduced P. australis is opportunistic and thrives in disturbed habitats. Thus, we expect to see substantial expansion of introduced P. australis with increasing anthropogenic disturbances in each of these regions. Although there have been some studies documenting the negative impacts of introduced P. australis, it also plays a beneficial role in some regions, and in some cases, the purported negative impacts are unproven. There is also a broader need to clarify the genetic and ecological relationships between the different introduced sublineages observed in North America, and their relative competitive ability and potential for admixture. This may be done through regional studies that use similar methodologies and share results to uncover common patterns and processes. To our knowledge, such studies have not been performed on P. australis in spite of the broad attention given to this species. Such research could advance theoretical knowledge on biological invasion by helping to determine the extent to which the patterns observed can be generalized or are sublineage specific or region specific. Synthesis Given what appears to be sometimes idiosyncratic invasion patterns when interpreted in isolation in the regions that we analysed, it may

  1. The Happiest Kids on Earth. Gender Equality and Adolescent Life Satisfaction in Europe and North America.

    Science.gov (United States)

    Looze, M E de; Huijts, T; Stevens, G W J M; Torsheim, T; Vollebergh, W A M

    2018-05-01

    Cross-national differences in adolescent life satisfaction in Europe and North America are consistent, but remain poorly understood. While previous studies have predominantly focused on the explanatory role of economic factors, such as national wealth and income equality, they revealed weak associations, at most. This study examines whether societal gender equality can explain the observed cross-national variability in adolescent life satisfaction. Based on the assumption that gender equality fosters a supportive social context, for example within families through a more equal involvement of fathers and mothers in child care tasks, adolescent life satisfaction was expected to be higher in more gender-equal countries. To test this hypothesis, national-level data of gender equality (i.e., women's share in political participation, decision making power, economic participation and command over resources) were linked to data from 175,470 adolescents aged 11-16 years old (M age  = 13.6, SD = 1.64, 52% girls) from 34 European and North American countries involved in the 2009/10 Health Behaviour in School-aged Children (HBSC) study. Results of linear multilevel regression analyses indicate that adolescents in countries with relatively high levels of gender equality report higher life satisfaction than their peers in countries with lower levels of gender equality. The association between gender equality and adolescent life satisfaction remained significant after controlling for national wealth and income equality. It was equally strong for boys and girls. Moreover, the association between gender equality and life satisfaction was explained by social support in the family, peer and school context. This analysis suggests that gender equality fosters social support among members of a society, which in turn contributes to adolescent life satisfaction. Thus, promoting gender equality is likely to benefit all members of a society; not just by giving equal rights to women

  2. Interannual variations and future change of wintertime extratropical cyclone activity over North America in CCSM3

    Energy Technology Data Exchange (ETDEWEB)

    Teng, Haiyan; Washington, Warren M.; Meehl, Gerald A. [National Center for Atmospheric Research, PO Box 3000, Boulder, CO (United States)

    2008-06-15

    Climatology and interannual variations of wintertime extratropical cyclone frequency in CCSM3 twentieth century simulation are compared with the NCEP/NCAR reanalysis during 1950-1999. CCSM3 can simulate the storm tracks reasonably well, although the model produces slightly less cyclones at the beginning of the Pacific and Atlantic storm tracks and weaker poleward deflection over the Pacific. As in the reanalysis, frequency of cyclones stronger than 980 hPa shows significant correlation with the Pacific/North America (PNA) teleconnection pattern over the Pacific region and with the North Atlantic Oscillation (NAO) in the Atlantic sector. Composite maps are constructed for opposite phases of El Nino-Southern Oscillation (ENSO) and the NAO and all anomalous patterns coincide with observed. One CCSM3 twenty-first century A1B scenario realization indicates there is significant increase in the extratropical cyclone frequency on the US west coast and decrease in Alaska. Meanwhile, cyclone frequency increases from the Great Lakes region to Quebec and decreases over the US east coast, suggesting a possible northward shift of the Atlantic storm tracks under the warmer climate. The cyclone frequency anomalies are closely linked to changes in seasonal mean states of the upper-troposphere zonal wind and baroclinicity in the lower troposphere. Due to lack of 6-hourly outputs, we cannot apply the cyclone-tracking algorithm to the other eight CCSM3 realizations. Based on the linkage between the mean state change and the cyclone frequency anomalies, it is likely a common feature among the other ensemble members that cyclone activity is reduced on the East Coast and in Alaska as a result of global warming. (orig.)

  3. Bioclimatic predictions of habitat suitability for the biofuel switchgrass in North America under current and future climate scenarios

    International Nuclear Information System (INIS)

    Barney, Jacob N.; DiTomaso, Joseph M.

    2010-01-01

    Dedicated biofuel crops, while providing economic and other benefits, may adversely impact biodiversity directly via land use conversion, or indirectly via creation of novel invasive species. To mitigate negative impacts bioclimatic envelope models (BEM) can be used to estimate the potential distribution and suitable habitat based on the climate and distribution in the native range. We used CLIMEX to evaluate the regions of North America suitable for agronomic production, as well as regions potentially susceptible to an invasion of switchgrass (Panicum virgatum) under both current and future climate scenarios. Model results show that >8.7 million km 2 of North America has suitable to very favorable habitat, most of which occurs east of the Rocky Mountains. The non-native range of western North America is largely unsuitable to switchgrass as a crop or potential weed unless irrigation or permanent water is available. Under both the CGCM2 and HadCM3 climate models and A2 and B2 emissions scenarios, an overall increase in suitable habitat is predicted over the coming century, although the western US remains unsuitable. Our results suggest that much of North America is suitable for switchgrass cultivation, although this is likely to shift north in the coming century. Our results also agree with field collections of switchgrass outside its native range, which indicate that switchgrass is unlikely to establish unless it has access to water throughout the year (e.g., along a stream). Thus, it is the potential invasion of switchgrass into riparian habitats in the West that requires further investigation. (author)

  4. Reconstructing Hydrologic Variability in Southwestern North America Using Speleothem Proxies and Precipitation Isotopes from California

    Science.gov (United States)

    McCabe-Glynn, Staryl

    Precipitation in southwestern North America has exhibited significant natural variability over the past few thousand years. This variability has been attributed to sea surface temperature regimes in the Pacific and Atlantic oceans, and to the attendant shifts in atmospheric circulation patterns. In particular, decadal variability in the North Pacific has influenced precipitation in this region during the twentieth century, but links to earlier droughts and pluvials are unclear. Here I assess these links using delta18 O measurements from a speleothem from southern California that spans AD 854-- 2007. I show that variations in the oxygen isotopes of the speleothem correlate to sea surface temperatures in the Kuroshio Extension region of the North Pacific, which affect the atmospheric trajectory and isotopic composition of moisture reaching the study site. Interpreting our speleothem data as a record of sea surface temperatures in the Kuroshio Extension, I find a strong 22-year periodicity, suggesting a persistent solar influence on North Pacific decadal variability. A comparison with tree-ring records of precipitation during the past millennium shows that some droughts occurred during periods of warmth in the Kuroshio Extension, similar to the instrumental record. However, other droughts did not and instead were likely influenced by other factors. The carbon isotope record indicates drier conditions are associated with higher delta13C values and may be a suitable proxy for reconstructing past drought variability. More research is needed to determine the controls on trace element concentrations. Finally, I find a significant increase in sea surface temperature variability over the past 150 years, which may reflect an influence of greenhouse gas concentrations on variability in the North Pacific. While drought is a common feature of climate in this region, most climate models also project extreme precipitation events to increase in frequency and severity because the

  5. The potential distribution of invading Helicoverpa armigera in North America: is it just a matter of time?

    Directory of Open Access Journals (Sweden)

    Darren J Kriticos

    Full Text Available Helicoverpa armigera has recently invaded South and Central America, and appears to be spreading rapidly. We update a previously developed potential distribution model to highlight the global invasion threat, with emphasis on the risks to the United States. The continued range expansion of H. armigera in Central America is likely to change the invasion threat it poses to North America qualitatively, making natural dispersal from either the Caribbean islands or Mexico feasible. To characterise the threat posed by H. armigera, we collated the value of the major host crops in the United States growing within its modelled potential range, including that area where it could expand its range during favourable seasons. We found that the annual value of crops that would be exposed to H. armigera totalled approximately US$78 billion p.a., with US$843 million p.a. worth growing in climates that are optimal for the pest. Elsewhere, H. armigera has developed broad-spectrum pesticide resistance; meaning that if it invades the United States, protecting these crops from significant production impacts could be challenging. It may be cost-effective to undertake pre-emptive biosecurity activities such as slowing the spread of H. armigera throughout the Americas, improving the system for detecting H. armigera, and methods for rapid identification, especially distinguishing between H. armigera, H. zea and potential H. armigera x H. zea hybrids. Developing biological control programs, especially using inundative techniques with entomopathogens and parasitoids could slow the spread of H. armigera, and reduce selective pressure for pesticide resistance. The rapid spread of H. armigera through South America into Central America suggests that its spread into North America is a matter of time. The likely natural dispersal routes preclude aggressive incursion responses, emphasizing the value of preparatory communication with agricultural producers in areas suitable for

  6. Multiscale perspectives of fire, climate and humans in western North America and the Jemez Mountains, USA.

    Science.gov (United States)

    Swetnam, Thomas W; Farella, Joshua; Roos, Christopher I; Liebmann, Matthew J; Falk, Donald A; Allen, Craig D

    2016-06-05

    Interannual climate variations have been important drivers of wildfire occurrence in ponderosa pine forests across western North America for at least 400 years, but at finer scales of mountain ranges and landscapes human land uses sometimes over-rode climate influences. We reconstruct and analyse effects of high human population densities in forests of the Jemez Mountains, New Mexico from ca 1300 CE to Present. Prior to the 1680 Pueblo Revolt, human land uses reduced the occurrence of widespread fires while simultaneously adding more ignitions resulting in many small-extent fires. During the 18th and 19th centuries, wet/dry oscillations and their effects on fuels dynamics controlled widespread fire occurrence. In the late 19th century, intensive livestock grazing disrupted fuels continuity and fire spread and then active fire suppression maintained the absence of widespread surface fires during most of the 20th century. The abundance and continuity of fuels is the most important controlling variable in fire regimes of these semi-arid forests. Reduction of widespread fires owing to reduction of fuel continuity emerges as a hallmark of extensive human impacts on past forests and fire regimes.This article is part of the themed issue 'The interaction of fire and mankind'. © 2016 The Authors.

  7. Postmortem evaluation of reintroduced migratory whooping cranes in eastern North America.

    Science.gov (United States)

    Cole, Gretchen A; Thomas, Nancy J; Spalding, Marilyn; Stroud, Richard; Urbanek, Richard P; Hartup, Barry K

    2009-01-01

    Reintroduction of endangered Whooping Cranes (Grus americana) in eastern North America has successfully established a migratory population between Wisconsin and Florida. Eighty birds (47 males, 33 females) were released between 2001 and 2006, and all birds were tracked following release with satellite and/or VHF monitoring devices. By the end of 2006, 17 deaths (12 males, five females) were recorded from this population. Postmortem findings and field data were evaluated for each bird to determine the cause of death. Causes included predation (n=8, 47%), trauma (n=2, 12%), and degenerative disease (n=1, 6%); the cause of death was undetermined for 35% (n=6) of the birds. Based on physical evidence, the primary predator of the birds was the bobcat (Lynx rufus). Limited roosting habitat availability or bird behavior were likely prime factors in the occurrence of predation. Traumatic injuries and mortality were caused by gunshot, electrical utility lines, and an unknown source. The lone case of degenerative disease was due to chronic exertional myopathy associated with translocation. Available postmortem testing did not indicate the presence of infectious disease in this limited sample.

  8. Book review: A chorus of cranes: The cranes of North America and the world

    Science.gov (United States)

    Pearse, Aaron T.

    2017-01-01

    Cranes (Gruidae) are widely distributed throughout the world, have lived on Earth for several million years, and currently reside on five continents. Archaeological evidence and historical references suggest that humans have interacted with and been captivated by cranes for many thousands of years (e.g., Leslie 1988, Muellner 1990). A glimpse of our reverence for these birds can be found in A Chorus of Cranes by Paul A. Johnsgard, with photographs by Thomas D. Mangelsen. Many species of cranes are currently identified as threatened or endangered, and their future will likely rest in the hands of humans; this book presents their plight and some of the measures that have been taken to conserve them. Dr. Johnsgard, an emeritus professor at the University of Nebraska-Lincoln, is a prolific writer, having written more than 60 books in ornithology and other topics. This book serves as the latest update of previous efforts concerning crane biology, conservation, and management. A review without making comparisons to his past works is difficult, yet this assessment will primarily focus on the content of the current book, with little reference to past endeavors.A Chorus of Cranes: The Cranes of North America and the World by Paul A. Johnsgard. 2015. University Press of Colorado, Boulder, CO, USA. x + 208 pp., 38 color photographs, 41 figures. ISBN 978-1-60732-436-2. $23.95 (Ebook). ISBN 978-1-60732-436-9.

  9. The greenhouse effect in central North America: If not now, when?

    International Nuclear Information System (INIS)

    Karl, T.R.; Heim, R.R. Jr.

    1991-01-01

    The consistency of the predictions of the Intergovernmental Panel on Climate Change (IPCC) with observed data are discussed, with reference to statistical models and Monte-Carlo simulation. Climate change projections for North America predict increases of temperature of 2-4 degree C by 2030. Analysis of the climate record over the last 95 years has failed to indicate statistically significant changes. Statistical models using auto-regressive moving-average techniques have been developed to calculate the likelihood that the greenhouse signal may have been masked by natural climate variability, and have indicated that there is a high probability that changes have been masked. However, some projections, such as the increase in ratio of winter to summer precipitation, should have been detected. The probability of not detecting temperature changes as large as projected range from 5% for large temperature increases to 65% for smaller increases, depending on the scenario. These results suggest that the projections of large increases in temperature of 3-4 degree C are inconsistent with past observation. It will likely take 15-20 years beyond 1990 before summer temperature increases would be detected, and over 40 years before summer precipitation decreases would be detected, assuming IPCC projections are basically correct. 13 refs., 3 figs., 4 tabs

  10. Geochemical site-selection criteria for HLW repositories in Europe and North America

    International Nuclear Information System (INIS)

    Savage, David; Arthur, Randolph C.; Sasamoto, Hiroshi; Shibata, Masahiro; Yui, Mikazu

    2000-01-01

    Geochemical as well as socio-economic issues associated with the selection of potential sites to host a high-level nuclear waste repository have received considerable attention in repository programs in Europe (Belgium, Finland, France, Germany, Spain, Sweden, Switzerland and the U.K.) and North America (Canada and the United States). The objective of the present study is to summarize this international experience with particular emphasis on geochemical properties that factor into the adopted site-selection strategies. Results indicate that the geochemical properties of a site play a subordinate role, at best, to other geotechnical properties in the international site-selection approaches. In countries where geochemical properties are acknowledged in the site-selection approach, requirements are stated qualitatively and tend to focus on associated impacts on the stability of the engineered barrier system and on radionuclide transport. Site geochemical properties that are likely to control the long-term stability of geochemical conditions and radionuclide migration behavior are unspecified, however. This non-prescriptive approach may be reasonable for purposes of screening among potential sites, but a better understanding of site properties that are most important in controlling the long-term geochemical evolution of the site over a range of possible scenarios would enable the potential sites to be ranked in terms of their suitability to host a repository. (author)

  11. Factors influencing mercury in freshwater surface sediments of northeastern North America

    Science.gov (United States)

    Kamman, N.C.; Chalmers, A.; Clair, T.A.; Major, A.; Moore, R.B.; Norton, S.A.; Shanley, J.B.

    2005-01-01

    We report on an inventory and analysis of sediment mercury (Hg) concentrations from 579 sites across northeastern North America. Sediment Hg concentrations ranged from the limit of detection ca. 0.01-3.7 ??g g -1 (dry weight, d.w.), and the average concentration was 0.19 ??g g-1 (d.w.) Sediment methylmercury concentrations ranged from 0.15 to 21 ng g-1 (d.w.) and the mean concentration was 3.83 ng g -1 (d.w.). Total Hg concentrations (HgT) were greatest in lakes > reservoirs > rivers, although the proportion of Hg as methylmercury showed an inverse pattern. Total Hg was weakly and positively correlated with the sediment organic matter and percent of watershed as forested land, and weakly and negatively correlated with sediment solids content, drainage area, and agricultural land. Sediment methylmercury concentrations were weakly and positively correlated to wetland area, and weakly and negatively correlated to drainage area. Methylmercury, expressed as a percentage of HgT was positively correlated to agricultural land area. For sites with co-located sediment and fish-tissue sampling results, there was no relationship between sediment Hg and fish-tissue Hg. Finally, our data indicate that at least 44% of waters across the region have sediment HgT concentrations in excess of Canadian and United States minimum sediment contaminant guidelines for the protection of aquatic biota. ?? 2005 Springer Science+Business Media, Inc.

  12. Songbirds as sentinels of mercury in terrestrial habitats of eastern North America

    Science.gov (United States)

    Jackson, Allyson K.; Evers, David C.; Adams, Evan M.; Cristol, Daniel A.; Eagles-Smith, Collin A.; Edmonds, Samuel T.; Gray, Carrie E.; Hoskins, Bart; Lane, Oksana P.; Sauer, Amy; Tear, Timothy

    2015-01-01

    Mercury (Hg) is a globally distributed environmental contaminant with a variety of deleterious effects in fish, wildlife, and humans. Breeding songbirds may be useful sentinels for Hg across diverse habitats because they can be effectively sampled, have well-defined and small territories, and can integrate pollutant exposure over time and space. We analyzed blood total Hg concentrations from 8,446 individuals of 102 species of songbirds, sampled on their breeding territories across 161 sites in eastern North America [geometric mean Hg concentration = 0.25 μg/g wet weight (ww), range freshwater or estuarine) than upland forests. Generally, adults exhibited higher blood Hg concentrations than juveniles within each habitat type. We used model results to examine species-specific differences in blood Hg concentrations during this time period, identifying potential Hg sentinels in each region and habitat type. Our results present the most comprehensive assessment of blood Hg concentrations in eastern songbirds to date, and thereby provide a valuable framework for designing and evaluating risk assessment schemes using sentinel songbird species in the time after implementation of the new atmospheric Hg standards.

  13. A 400-year tree-ring chronology from the tropical treeline of North America.

    Science.gov (United States)

    Biondi, F

    2001-05-01

    High-elevation sites in the tropics may be particularly sensitive to rapid climate change. By sampling treeline populations, I have developed the first extensive (> 300 years) tree-ring chronology in tropical North America. The site is Nevado de Colima, at the western end of the Mexican Neovolcanic Belt, and the species studied is Mexican mountain pine (Pinus hartwegii). Despite past logging in the area, 300 to 500-year old pines were found at 3600-3700 m elevation, about 300 m below the present treeline. The Nevado de Colima tree-ring chronology is well replicated from 1600 to 1997. Calibration with Colima climatic records points to summer monsoon precipitation as the strongest dendroclimatic signal. Most trees also exhibit extremely low growth in 1913 and 1914, following the January 1913 Plinian eruption of the Volcan de Colima. Because P. hartwegii is found on top of high mountains from Mexico to Guatemala, there is potential for developing a network of tropical treeline chronologies.

  14. Origin of the Blue Ridge escarpment along the passive margin of Eastern North America

    Science.gov (United States)

    Spotila, J.A.; Bank, G.C.; Reiners, P.W.; Naeser, C.W.; Naeser, N.D.; Henika, B.S.

    2004-01-01

    The Blue Ridge escarpment is a rugged landform situated within the ancient Appalachian orogen. While similar in some respects to the great escarpments along other passive margins, which have evolved by erosion following rifting, its youthful topographic expression has inspired proposals of Cenozoic tectonic rejuvenation in eastern North America. To better understand the post-orogenic and post-rift geomorphic evolution of passive margins, we have examined the origin of this landform using low-temperature thermochronometry and manipulation of topographic indices. Apatite (U-Th)/He and fission-track analyses along transects across the escarpment reveal a younging trend towards the coast. This pattern is consistent with other great escarpments and fits with an interpretation of having evolved by prolonged erosion, without the requirement of tectonic rejuvenation. Measured ages are also comparable specifically to those measured along other great escarpments that are as much as 100 Myr younger. This suggests that erosional mechanisms that maintain rugged escarpments in the early post-rift stages may remain active on ancient passive margins for prolonged periods. The precise erosional evolution of the escarpment is less clear, however, and several end-member models can explain the data. Our preferred model, which fits with all data, involves a significant degree of erosional escarpment retreat in the Cenozoic. Although this suggests that early onset of topographic stability is not required of passive margin evolution, more data are required to better constrain the details of the escarpment's development. ?? 2003 Blackwell Publishing Ltd.

  15. A robust null hypothesis for the potential causes of megadrought in western North America

    Science.gov (United States)

    Ault, T.; St George, S.; Smerdon, J. E.; Coats, S.; Mankin, J. S.; Cruz, C. C.; Cook, B.; Stevenson, S.

    2017-12-01

    The western United States was affected by several megadroughts during the last 1200 years, most prominently during the Medieval Climate Anomaly (MCA: 800 to 1300 CE). A null hypothesis is developed to test the possibility that, given a sufficiently long period of time, these events are inevitable and occur purely as a consequence of internal climate variability. The null distribution of this hypothesis is populated by a linear inverse model (LIM) constructed from global sea-surface temperature anomalies and self-calibrated Palmer Drought Severity Index data for North America. Despite being trained only on seasonal data from the late 20th century, the LIM produces megadroughts that are comparable in their duration, spatial scale, and magnitude as the most severe events of the last 12 centuries. The null hypothesis therefore cannot be rejected with much confidence when considering these features of megadrought, meaning that similar events are possible today, even without any changes to boundary conditions. In contrast, the observed clustering of megadroughts in the MCA, as well as the change in mean hydroclimate between the MCA and the 1500-2000 period, are more likely to have been caused by either external forcing or by internal climate variability not well sampled during the latter half of the Twentieth Century. Finally, the results demonstrate the LIM is a viable tool for determining whether paleoclimate reconstructions events should be ascribed to external forcings, "out of sample" climate mechanisms, or if they are consistent with the variability observed during the recent period.

  16. Sustained by First Nations: European newcomers' use of Indigenous plant foods in temperate North America

    Directory of Open Access Journals (Sweden)

    Nancy J. Turner

    2012-12-01

    Full Text Available Indigenous Peoples of North America have collectively used approximately 1800 different native species of plants, algae, lichens and fungi as food. When European explorers, traders and settlers arrived on the continent, these native foods, often identified and offered by Indigenous hosts, gave them sustenance and in some cases saved them from starvation. Over the years, some of these species – particularly various types of berries, such as blueberries and cranberries (Vaccinium spp., wild raspberries and blackberries (Rubus spp., and wild strawberries (Fragaria spp., and various types of nuts (Corylus spp., Carya spp., Juglans spp., Pinus spp., along with wild-rice (Zizania spp. and maple syrup (from Acer saccharum – became more widely adopted and remain in use to the present day. Some of these and some other species were used in plant breeding programs, as germplasm for hybridization programs, or to strengthen a crop's resistance to disease. At the same time, many nutritious Indigenous foods fell out of use among Indigenous Peoples themselves, and along with their lessened use came a loss of associated knowledge and cultural identity. Today, for a variety of reasons, from improving people's health and regaining their cultural heritage, to enhancing dietary diversity and enjoyment of diverse foods, some of the species that have dwindled in their use have been “rediscovered” by Indigenous and non-Indigenous Peoples, and indications are that their benefits to humanity will continue into the future.

  17. Songbirds as sentinels of mercury in terrestrial habitats of eastern North America

    Science.gov (United States)

    Jackson, Allyson K.; Evers, David C.; Adams, Evan M.; Cristol, Daniel A.; Eagles-Smith, Collin A.; Edmonds, Samuel T.; Gray, Carrie E.; Hoskins, Bart; Lane, Oksana P.; Sauer, Amy; Tear, Timothy

    2015-01-01

    Mercury (Hg) is a globally distributed environmental contaminant with a variety of deleterious effects in fish, wildlife, and humans. Breeding songbirds may be useful sentinels for Hg across diverse habitats because they can be effectively sampled, have well-defined and small territories, and can integrate pollutant exposure over time and space. We analyzed blood total Hg concentrations from 8,446 individuals of 102 species of songbirds, sampled on their breeding territories across 161 sites in eastern North America [geometric mean Hg concentration = 0.25 μg/g wet weight (ww), range of the USEPA Mercury and Air Toxics Standards, which will reduce Hg emissions from coal-fired power plants by over 90 %. Mixed-effects modeling indicated that habitat, foraging guild, and age were important predictors of blood Hg concentrations across species and sites. Blood Hg concentrations in adult invertebrate-eating songbirds were consistently higher in wetland habitats (freshwater or estuarine) than upland forests. Generally, adults exhibited higher blood Hg concentrations than juveniles within each habitat type. We used model results to examine species-specific differences in blood Hg concentrations during this time period, identifying potential Hg sentinels in each region and habitat type. Our results present the most comprehensive assessment of blood Hg concentrations in eastern songbirds to date, and thereby provide a valuable framework for designing and evaluating risk assessment schemes using sentinel songbird species in the time after implementation of the new atmospheric Hg standards.

  18. The marketing of dietary supplements in North America: the emperor is (almost) naked.

    Science.gov (United States)

    Temple, Norman J

    2010-07-01

    Many different dietary supplements are being sold in North America. The quality of the evidence supporting their efficacy covers a wide spectrum: Some are based on solid science (such as vitamin D and fish oil), whereas with most supplements there is little or no supporting evidence. Types of supplements commonly sold include exotic fruit juices (such as goji juice) and single herbs or mixture of herbs. Common claims made in support of particular supplements are that they are rich in antioxidants, induce detoxification, stimulate the immune system, and cause weight loss. Supplements are commonly sold through health food stores and by multilevel marketing. Sales may be promoted using bulk mail ("junk mail"), spam e-mails, and Web sites. A large part of marketing is based on claims that are blatantly dishonest. Whereas supplements for which good supporting evidence exists generally cost around $3-$4 per month, those that are heavily promoted for which there is little supporting evidence cost about $20-$60 per month. The major cause of this problem in the United States is weakness of the law. There is an urgent need for stricter regulation and for giving better advice to the general public.

  19. Reconstruction of caribou evolutionary history in Western North America and its implications for conservation.

    Science.gov (United States)

    Weckworth, Byron V; Musiani, Marco; McDevitt, Allan D; Hebblewhite, Mark; Mariani, Stefano

    2012-07-01

    The role of Beringia as a refugium and route for trans-continental exchange of fauna during glacial cycles of the past 2million years are well documented; less apparent is its contribution as a significant reservoir of genetic diversity. Using mitochondrial DNA sequences and 14 microsatellite loci, we investigate the phylogeographic history of caribou (Rangifer tarandus) in western North America. Patterns of genetic diversity reveal two distinct groups of caribou. Caribou classified as a Northern group, of Beringian origin, exhibited greater number and variability in mtDNA haplotypes compared to a Southern group originating from refugia south of glacial ice. Results indicate that subspecies R. t. granti of Alaska and R. t. groenlandicus of northern Canada do not constitute distinguishable units at mtDNA or microsatellites, belying their current status as separate subspecies. Additionally, the Northern Mountain ecotype of woodland caribou (presently R. t. caribou) has closer kinship to caribou classified as granti or groenlandicus. Comparisons of mtDNA and microsatellite data suggest that behavioural and ecological specialization is a more recently derived life history characteristic. Notably, microsatellite differentiation among Southern herds is significantly greater, most likely as a result of human-induced landscape fragmentation and genetic drift due to smaller population sizes. These results not only provide important insight into the evolutionary history of northern species such as caribou, but also are important indicators for managers evaluating conservation measures for this threatened species. © 2012 Blackwell Publishing Ltd.

  20. Environment, vegetation and greenness (NDVI) along the North America and Eurasia Arctic transects

    International Nuclear Information System (INIS)

    Walker, D A; Raynolds, M K; Kuss, P; Kade, A N; Epstein, H E; Frost, G V; Kopecky, M A; Daniëls, F J A; Leibman, M O; Moskalenko, N G; Khomutov, A V; Matyshak, G V; Khitun, O V; Forbes, B C; Bhatt, U S; Vonlanthen, C M; Tichý, L

    2012-01-01

    Satellite-based measurements of the normalized difference vegetation index (NDVI; an index of vegetation greenness and photosynthetic capacity) indicate that tundra environments are generally greening and becoming more productive as climates warm in the Arctic. The greening, however, varies and is even negative in some parts of the Arctic. To help interpret the space-based observations, the International Polar Year (IPY) Greening of the Arctic project conducted ground-based surveys along two >1500 km transects that span all five Arctic bioclimate subzones. Here we summarize the climate, soil, vegetation, biomass, and spectral information collected from the North America Arctic transect (NAAT), which has a more continental climate, and the Eurasia Arctic transect (EAT), which has a more oceanic climate. The transects have broadly similar summer temperature regimes and overall vegetation physiognomy, but strong differences in precipitation, especially winter precipitation, soil texture and pH, disturbance regimes, and plant species composition and structure. The results indicate that summer warmth and NDVI increased more strongly along the more continental transect. (letter)