WorldWideScience

Sample records for north american tropical

  1. First North American fossil monkey and early Miocene tropical biotic interchange

    Science.gov (United States)

    Bloch, Jonathan I.; Woodruff, Emily D.; Wood, Aaron R.; Rincon, Aldo F.; Harrington, Arianna R.; Morgan, Gary S.; Foster, David A.; Montes, Camilo; Jaramillo, Carlos A.; Jud, Nathan A.; Jones, Douglas S.; MacFadden, Bruce J.

    2016-05-01

    New World monkeys (platyrrhines) are a diverse part of modern tropical ecosystems in North and South America, yet their early evolutionary history in the tropics is largely unknown. Molecular divergence estimates suggest that primates arrived in tropical Central America, the southern-most extent of the North American landmass, with several dispersals from South America starting with the emergence of the Isthmus of Panama 3-4 million years ago (Ma). The complete absence of primate fossils from Central America has, however, limited our understanding of their history in the New World. Here we present the first description of a fossil monkey recovered from the North American landmass, the oldest known crown platyrrhine, from a precisely dated 20.9-Ma layer in the Las Cascadas Formation in the Panama Canal Basin, Panama. This discovery suggests that family-level diversification of extant New World monkeys occurred in the tropics, with new divergence estimates for Cebidae between 22 and 25 Ma, and provides the oldest fossil evidence for mammalian interchange between South and North America. The timing is consistent with recent tectonic reconstructions of a relatively narrow Central American Seaway in the early Miocene epoch, coincident with over-water dispersals inferred for many other groups of animals and plants. Discovery of an early Miocene primate in Panama provides evidence for a circum-Caribbean tropical distribution of New World monkeys by this time, with ocean barriers not wholly restricting their northward movements, requiring a complex set of ecological factors to explain their absence in well-sampled similarly aged localities at higher latitudes of North America.

  2. Insight into the Pacific Sea Surface Temperature- North American Hydroclimate Connection from an Eastern Tropical North Pacific Coral Record

    Science.gov (United States)

    Sanchez, S. C.; Charles, C. D.; Carriquiry, J. D.

    2015-12-01

    The last few years of record-breaking climate anomalies across North America--a resilient atmospheric ridge and extreme drought over the West Coast, and severe winters across the Midwest and East Coast regions--have been linked to anomalous Pacific sea surface temperatures (Seager et al. 2014, Wang et al. 2014, Hartmann 2015). The synoptic associations prompt important questions on the relation between these unusual phenomena and extreme expressions of known Pacific decadal modes, such as the North Pacific Gyre Oscillation (NPGO). These questions motivate our pursuit to document multiple realizations of decadal variability in the Pacific-North American region through periods of varied radiative forcing. Here we introduce a 178 year, seasonally resolved Porites coral record from Clarion Island (18N, 115W), the westernmost island of the Revillagigedo Archipelago, a region both highly influenced by NPGO SST and SSS variability and critical for NPGO tropical-extratropical communication via the Seasonal Footprinting Mechanism (Vimont et al. 2003). When coupled with tree ring records from the western United States (Griffin and Anchukaitis 2014, MacDonald and Case 2005) and coral records from the central tropical Pacific (Cobb et al. 2001), the δ18O signal from the Clarion coral offers an extended framework of coherent continental hydroclimate and oceanic variability across the Pacific basin beyond the instrumental record. Over the last 200 years, we find clear commonality in the timing, magnitude and spatial expression of variability (illustrated through the NADA Atlas, Cook et al. 2004) amongst the proxy records. The strong relationship between Northeastern Pacific Clarion and the Central Pacific Palmyra record with the North American hydroclimate records can be viewed within the mechanistic framework of the NPGO; this framework is then explored over the last millennium across intervals of varied radiative forcing.

  3. North American refining

    International Nuclear Information System (INIS)

    Osten, James; Haltmaier, Susan

    2000-01-01

    This article examines the current status of the North American refining industry, and considers the North American economy and the growth in demand in the petroleum industry, petroleum product demand and quality, crude oil upgrading to meet product standards, and changes in crude oil feedstocks such as the use of heavier crudes and bitumens. Refining expansion, the declining profits in refining, and changes due to environmental standards are discussed. The Gross Domestic Product and oil demand for the USA, Canada, Mexico, and Venezuela for the years 1995-2020 are tabulated

  4. Carbon dioxide and water vapour exchange in a tropical dry forest as influenced by the North American Monsoon System (NAMS)

    Science.gov (United States)

    To better understand the effects and relationship between precipitation, net ecosystem carbon dioxide (NEE) and water vapor exchange (ET), we report a study conducted in the tropical dry forest (TDF) in the northwest of Mexico. Ecosystem gas exchange was measured using the eddy correlation technique...

  5. Tropical North Atlantic ocean-atmosphere interactions synchronize forest carbon losses from hurricanes and Amazon fires

    OpenAIRE

    Chen, Y; Randerson, JT; Morton, DC

    2015-01-01

    ©2015. American Geophysical Union. All Rights Reserved. We describe a climate mode synchronizing forest carbon losses from North and South America by analyzing time series of tropical North Atlantic sea surface temperatures (SSTs), landfall hurricanes and tropical storms, and Amazon fires during 1995-2013. Years with anomalously high tropical North Atlantic SSTs during March-June were often followed by a more active hurricane season and a larger number of satellite-detected fires in the south...

  6. North American Regional Report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-11-15

    North America is an energy community fortunate to be endowed with a rich and varied resource base. It consumes about a third of the world's energy and produces about one quarter of world energy supply. North America depends on a mix of complementary energy sources that should remain competitive but not in conflict. The current supply mix varies between Canada, the United States and Mexico, but fossil fuels are dominant across the region, leaving the three member countries vulnerable to a myriad of risks associated with traditional supply sources. Energy trade between all three countries is also a major contributor to the region's economy. Thus, the impetus for collaboration across the region has grown out of the common goals of energy security and economic prosperity. The goal of the WEC regional group was to discuss avenues for advancing North American cooperation and coordination on a range of energy issues. An additional objective was to develop policy recommendations that will facilitate effective development and use of the region's energy resources. Results and recommendtaions are summarized from three forums that focused on the pertinent issues of energy trade, energy efficiency and energy diversification. The inaugural forum (Energy Trade) was held in Washington, D.C. in the fall of 2005. The following summer, the second forum (Energy Efficiency) took place in Mexico City. The third forum (Energy Diversification) was hosted in Halifax, Nova Scotia.

  7. North American Regional Report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-11-15

    North America is an energy community fortunate to be endowed with a rich and varied resource base. It consumes about a third of the world's energy and produces about one quarter of world energy supply. North America depends on a mix of complementary energy sources that should remain competitive but not in conflict. The current supply mix varies between Canada, the United States and Mexico, but fossil fuels are dominant across the region, leaving the three member countries vulnerable to a myriad of risks associated with traditional supply sources. Energy trade between all three countries is also a major contributor to the region's economy. Thus, the impetus for collaboration across the region has grown out of the common goals of energy security and economic prosperity. The goal of the WEC regional group was to discuss avenues for advancing North American cooperation and coordination on a range of energy issues. An additional objective was to develop policy recommendations that will facilitate effective development and use of the region's energy resources. Results and recommendtaions are summarized from three forums that focused on the pertinent issues of energy trade, energy efficiency and energy diversification. The inaugural forum (Energy Trade) was held in Washington, D.C. in the fall of 2005. The following summer, the second forum (Energy Efficiency) took place in Mexico City. The third forum (Energy Diversification) was hosted in Halifax, Nova Scotia.

  8. North American oil demand outlook

    International Nuclear Information System (INIS)

    Stewart, M.B.

    1995-01-01

    An understanding of the relationship of economic growth and potential petroleum product demand is needed to forecast the potential for North American oil demand growth as well as knowledge of world supply and price. The bullish expectations for economic growth in the US and Canada auger well for North American refiners and marketeers. The growth in world economic output forecast, however, means a larger oil demand and an increase in OPEC's pricing power. Such price increases could depress North American oil demand growth. (author)

  9. Propane: North American opportunities

    International Nuclear Information System (INIS)

    Dempsey, C.

    1992-01-01

    Opportunities for expanding the propane market in North America are discussed. The goal of change should be to enhance client satisfaction and loyalty. The current customer base is largely comprised of pick-up trucks, vans and buses in commercial fleet service, police and similar fleet service and privately owned vehicles. Opportunities for the expansion of propane exist due to: vehicles being kept and lasting longer, allowing a longer pay-back time; exhaust emission standards becoming more stringent; the possible introduction of emission standards for substances currently not controlled; and properly combusted CO 2 emissions that are at least 12% lower than gasoline. The continuing development of engine fuel management systems, application of extensive road/highway experience, matching supply and refuelling infrastructure to consumer demands, application in air quality non-attainment areas, and original equipment manufacturer, government and industry cooperation are discussed. 8 figs

  10. The Zoogeography of North American freshwater fishes

    National Research Council Canada - National Science Library

    Hocutt, Charles H; Wiley, E. O

    1986-01-01

    ..., and Pleistoscene glaciation. The Zoogeography of North American Freshwater Fishes is a comprehensive treatment of the freshwater biogeography of North America, with implications for other disciplines...

  11. North American Foreign Fighters

    Directory of Open Access Journals (Sweden)

    Michael Noonan

    2014-12-01

    Full Text Available While the phenomenon of so-called “foreign fighters” is in no way new the past thirty-plus years has shown a marked increase in the numbers of individuals traveling abroad to fight in civil conflicts in the Muslim world. The crisis in Syria (2011-present has created a massive influx of such individuals going to fight. Of particular concern in western capitals has been the numbers of individuals from those countries that have gone to fight in that conflict which has since crossed the border into neighboring Iraq with the establishment of the socalled “Islamic State” and threatens to broaden the conflict into a larger regional sectarian conflagration. While the numbers of such participants from Western Europe have been greater than those who have gone from the United States and Canada there are legitimate concerns in both Washington, DC, and Ottawa about American and Canadian citizens who have gone—or attempted to go—to fight there and in other locales such as the Maghreb and Somalia. The analysis here will provide some background on the foreign fighter phenomenon, discuss the foreign fighter flow model, explore the issue from both Canadian and US perspectives to include providing details of some original research categorizing the characteristics of a small sample of US and Canadian fighters and those who attempted to go and fight, discuss how both governments have attempted to deal with the issue, and offer some policy prescription for dealing with this issue that is of importance to both international security writ large and domestic security in the US and Canada.

  12. North American Natural Gas Markets

    Energy Technology Data Exchange (ETDEWEB)

    1988-12-01

    This report sunnnarizes the research by an Energy Modeling Forum working group on the evolution of the North American natural gas markets between now and 2010. The group's findings are based partly on the results of a set of economic models of the natural gas industry that were run for four scenarios representing significantly different conditions: two oil price scenarios (upper and lower), a smaller total US resource base (low US resource case), and increased potential gas demand for electric generation (high US demand case). Several issues, such as the direction of regulatory policy and the size of the gas resource base, were analyzed separately without the use of models.

  13. North American Natural Gas Markets

    International Nuclear Information System (INIS)

    1989-02-01

    This report summarizes die research by an Energy Modeling Forum working group on the evolution of the North American natural gas markets between now and 2010. The group's findings are based partly on the results of a set of economic models of the natural gas industry that were run for four scenarios representing significantly different conditions: two oil price scenarios (upper and lower), a smaller total US resource base (low US resource case), and increased potential gas demand for electric generation (high US demand case). Several issues, such as the direction of regulatory policy and the size of the gas resource base, were analyzed separately without the use of models

  14. North American Natural Gas Markets

    International Nuclear Information System (INIS)

    1988-12-01

    This report sunnnarizes the research by an Energy Modeling Forum working group on the evolution of the North American natural gas markets between now and 2010. The group's findings are based partly on the results of a set of economic models of the natural gas industry that were run for four scenarios representing significantly different conditions: two oil price scenarios (upper and lower), a smaller total US resource base (low US resource case), and increased potential gas demand for electric generation (high US demand case). Several issues, such as the direction of regulatory policy and the size of the gas resource base, were analyzed separately without the use of models

  15. North American Natural Gas Markets

    Energy Technology Data Exchange (ETDEWEB)

    1989-02-01

    This report summarizes die research by an Energy Modeling Forum working group on the evolution of the North American natural gas markets between now and 2010. The group's findings are based partly on the results of a set of economic models of the natural gas industry that were run for four scenarios representing significantly different conditions: two oil price scenarios (upper and lower), a smaller total US resource base (low US resource case), and increased potential gas demand for electric generation (high US demand case). Several issues, such as the direction of regulatory policy and the size of the gas resource base, were analyzed separately without the use of models.

  16. The North American Transborder Freight Database

    Data.gov (United States)

    Department of Transportation — The North American Transborder Freight Database, available since April 1993, contains freight flow data by commodity type and by mode of transportation (rail, truck,...

  17. North American sturgeon otolith morphology

    Science.gov (United States)

    Chalupnicki, Marc A.; Dittman, Dawn E.

    2016-01-01

    Accurate expedient species identification of deceased sturgeon (Acipenseridae) when external physical characteristic analysis is inconclusive has become a high priority due to the endangered or threatened status of sturgeon species around the world. Examination of otoliths has provided useful information to aid in population management, age and size-class analysis, understanding predator–prey interactions, and archeological research in other fish species. The relationship between otolith characteristics and sturgeon species has remained unknown. Therefore, we analyzed the shape of otoliths from the eight species of sturgeon found in North America to test the utility of otolith characteristic morphology in species identification. There were distinct differences in the size and shape of the otoliths between species of sturgeon with little shape variation among individuals of the same species. The relationship between otolith length axes was linear, and most of the variability was explained by a Log (axis + 1) transformation of the x and y axes (r2 = 0.8983) using the equation y = 0.73x + 0.0612. Images of otoliths from all eight North American species are presented to assist in the identification process.

  18. The carbon balance of North American wetlands

    Science.gov (United States)

    Scott D. Bridgham; J. Patrick Megonigal; Jason K. Keller; Norman b. Bliss; Carl Trettin

    2006-01-01

    We examine the carbon balance of North American wetlands by reviewing and synthesizing the published literature and soil databases. North American wetlands contain about 220 Pg C, most of which is in peat. They are a small to moderate carbon sink of about 49 Tg C yr-l, although the uncertainty around this estimate is greater than 100%, with the...

  19. North Dakota Native American Essential Understandings

    Science.gov (United States)

    North Dakota Department of Public Instruction, 2015

    2015-01-01

    In the spring of 2015, the North Dakota Department of Public Instruction brought together tribal Elders from across North Dakota to share stories, memories, songs, and wisdom in order to develop the North Dakota Native American Essential Understandings (NDNAEU) to guide the learning of both Native and non-Native students across the state. They…

  20. The North American electricity markets

    International Nuclear Information System (INIS)

    Harvie, I.

    1999-01-01

    The wide ranging changes that will drive the evolution of the North American electricity industry in the future are discussed. Deregulation and the advent of competition in both the United States and Canada are the principal forces that will change the shape of the electricity market, bringing new players and new forms of doing business into the marketplace. A review of the current state of the business shows that especially in the United States where deregulation began earlier than in Canada, independent generators already constitute a multi-billion dollar industry. Non-utility generation capacity is about seven per cent of total U.S. capacity and accounts for about 10 per cent of total U. S. electricity supply, including imports. Examples from other industries clearly show that restructuring and the breakup of vertically integrated industries could be accomplished much faster than anticipated, that a decrease in prices followed rapidly as products became more like commodities, and that decreasing prices fostered product differentiation and competition. Major legislation affecting the electric power industry in the U.S. and Canada (U.S. National Energy Policy Act 1992, Alberta Electric Utilities Act 1995, Ontario Energy Competition Act 1998) decreeing open access transmission, unbundling of generation, transmission and ancillary services, and promoting competition, and the impacts of these legislative actions are also reviewed. The most visible impact is the explosion that can be seen in power marketing and energy trading on a scale unimaginable only a few short years ago, where the total volume of trade may be worth multiples of the value of the underlying commodity. At the same time, there is concern about the reliability of the system, and thus making it imperative to find new ways to manage reliability. Various suggestions are made as to how increased reliability of supply could be achieved by better management, new standards and better enforcement of

  1. NCEP North American Regional Reanalysis (NARR)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NARR dataset is an extension of the NCEP Global Reanalysis which is run over the North American Region. The NARR model uses the very high resolution NCEP Eta...

  2. The message in North American energy prices

    Energy Technology Data Exchange (ETDEWEB)

    Serletis, A. [Department of Economics, The University of Calgary, Calgary, Alberta (Canada); Herbert, J. [Virginia Polytechnic Institute and State University, Blacksburg, Virginia (United States)

    1999-10-01

    How similar is the price behavior of North American natural gas, fuel oil, and power prices? Using current state-of-the-art econometric methodology, we explore the degree of shared trends across North American energy markets. Across these markets, there appear to be effective arbitraging mechanisms for the price of natural gas and fuel oil, but not for the price of electricity. 11 refs.

  3. Atmospheric teleconnection influence on North American land surface phenology

    Science.gov (United States)

    Dannenberg, Matthew P.; Wise, Erika K.; Janko, Mark; Hwang, Taehee; Kolby Smith, W.

    2018-03-01

    Short-term forecasts of vegetation activity are currently not well constrained due largely to our lack of understanding of coupled climate-vegetation dynamics mediated by complex interactions between atmospheric teleconnection patterns. Using ecoregion-scale estimates of North American vegetation activity inferred from remote sensing (1982-2015), we examined seasonal and spatial relationships between land surface phenology and the atmospheric components of five teleconnection patterns over the tropical Pacific, north Pacific, and north Atlantic. Using a set of regression experiments, we also tested for interactions among these teleconnection patterns and assessed predictability of vegetation activity solely based on knowledge of atmospheric teleconnection indices. Autumn-to-winter composites of the Southern Oscillation Index (SOI) were strongly correlated with start of growing season timing, especially in the Pacific Northwest. The two leading modes of north Pacific variability (the Pacific-North American, PNA, and West Pacific patterns) were significantly correlated with start of growing season timing across much of southern Canada and the upper Great Lakes. Regression models based on these Pacific teleconnections were skillful predictors of spring phenology across an east-west swath of temperate and boreal North America, between 40°N-60°N. While the North Atlantic Oscillation (NAO) was not strongly correlated with start of growing season timing on its own, we found compelling evidence of widespread NAO-SOI and NAO-PNA interaction effects. These results suggest that knowledge of atmospheric conditions over the Pacific and Atlantic Oceans increases the predictability of North American spring phenology. A more robust consideration of the complexity of the atmospheric circulation system, including interactions across multiple ocean basins, is an important step towards accurate forecasts of vegetation activity.

  4. Phytogeography of the tropical north-east African mountains

    Directory of Open Access Journals (Sweden)

    I. Friis

    1983-11-01

    Full Text Available The tropical north-east African mountains are tentatively divided into four phytochoria, the formal rank of which is not defined. The division is based on patterns of distribution and endemism in the region. The recognition of a distinct Afromontane phytochorion is now well established (Chapman & White, 1970; Werger, 1978; White, 1978. However, there is still very little information on the phytogeography of the individual mountains or mountain systems. This study hopes to fill a little of the gap by analysing distribution patterns and patterns of endemism in the flora of the tropical north-east African mountains. The north-east African mountain system is the largest in tropical Africa (see e.g. map in White, 1978. At the core of this system is the large Ethiopian massif, around which are located various mountains and mountain chains. These include the Red Sea Hills in the Sudan, the mountain chain in northern Somalia, the south-west Arabian mountains, and the Imatong mountains of south-east Sudan. The latter are often referred to the East African mountain system (White, 1978 but. as I will point out later, they also have a close connection with the south-west highlands of Ethiopia. The paper presents some results of my study of the mountain flora of tropical north-east Africa, particularly the forest species. Where no source is indicated, the data are from my own unpublished studies.

  5. 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.

  6. Analysis of Tropical Cyclone Tracks in the North Indian Ocean

    Science.gov (United States)

    Patwardhan, A.; Paliwal, M.; Mohapatra, M.

    2011-12-01

    Cyclones are regarded as one of the most dangerous meteorological phenomena of the tropical region. The probability of landfall of a tropical cyclone depends on its movement (trajectory). Analysis of trajectories of tropical cyclones could be useful for identifying potentially predictable characteristics. There is long history of analysis of tropical cyclones tracks. A common approach is using different clustering techniques to group the cyclone tracks on the basis of certain characteristics. Various clustering method have been used to study the tropical cyclones in different ocean basins like western North Pacific ocean (Elsner and Liu, 2003; Camargo et al., 2007), North Atlantic Ocean (Elsner, 2003; Gaffney et al. 2007; Nakamura et al., 2009). In this study, tropical cyclone tracks in the North Indian Ocean basin, for the period 1961-2010 have been analyzed and grouped into clusters based on their spatial characteristics. A tropical cyclone trajectory is approximated as an open curve and described by its first two moments. The resulting clusters have different centroid locations and also differently shaped variance ellipses. These track characteristics are then used in the standard clustering algorithms which allow the whole track shape, length, and location to be incorporated into the clustering methodology. The resulting clusters have different genesis locations and trajectory shapes. We have also examined characteristics such as life span, maximum sustained wind speed, landfall, seasonality, many of which are significantly different across the identified clusters. The clustering approach groups cyclones with higher maximum wind speed and longest life span in to one cluster. Another cluster includes short duration cyclonic events that are mostly deep depressions and significant for rainfall over Eastern and Central India. The clustering approach is likely to prove useful for analysis of events of significance with regard to impacts.

  7. North American supply/demand

    International Nuclear Information System (INIS)

    Pocino, M.C.

    1998-01-01

    The projected supply and demand for natural gas in five major regions of North America for the year 2000 was presented. In most regions, supply is expected to be greater than demand. A summary of how California dealt with an increase in natural gas demand in 1990 was presented. The California strategy included a readjustment of pipeline capacity, storage capacity and transportation. Whereas in the 1980s, when capacity was inadequate, the focus was on competition with alternate fuels, maximized capacity use, primary concern about reliability and only secondary concern about price, in the the 1990s, with excess capacity, the emphasis is on 'gas on gas' competition, efforts to satisfy the customer, primary concern about price, and only marginal concern about reliability. tabs., figs

  8. Should we establish a North American school of global health sciences?

    Science.gov (United States)

    Hotez, Peter J

    2004-08-01

    Since 1997, an unprecedented amount of American philanthropy from both private and federal sources has been directed toward research and control programs for the major tropical infectious diseases of developing countries. The US and Canadian capacity to respond to these new initiatives might prove inadequate, however, as tropical disease research and training infrastructures have deteriorated at most North American academic health centers over the last three decades. Training opportunities in clinical tropical medicine, parasitology laboratory diagnostics, vector control, and public health practice are especially depleted and portend a lost generation of experts in these areas. In addition, unlike some of the European schools of tropical medicine, no North American medical or public health school currently boasts a comprehensive faculty in the global health sciences, with expertise that spans laboratory investigation, clinical and translational research, health policy, and international development. To meet the challenge presented by the new philanthropy targeting the global diseases of poverty, a North American school of global health sciences should be established. The North American school, possibly in association with one of the existing schools of medicine or public health, would provide interdisciplinary training to produce a new generation of global health scientists.

  9. Is There Really A North American Plate?

    Science.gov (United States)

    Krill, A.

    2011-12-01

    Lithospheric plates are typically identified from earthquake epicenters and evidence such as GPS movements. But no evidence indicates a plate boundary between the North American and South American Plates. Some plate maps show them separated by a transform boundary, but it is only a fracture zone. Other maps show an "undefined plate boundary" or put no boundary between these two plates (check Google images). Early plate maps showed a single large American Plate, quite narrow east of the Caribbean Plate (Le Pichon 1968, Morgan 1968). The North and South American Plates became established by the leading textbook Earth (Press & Siever 1974). On their map, from a Scientific American article by John Dewey (1972), these new plates were separated by an "uncertain plate boundary." The reasons for postulating a North American Plate were probably more psychological than geological. Each of the other continents of the world had its own plate, and North American geologists naturally wanted theirs. Similarly, European geographers used to view Europe as its own continent. A single large plate should again be hypothesized. But the term American Plate would now be ambiguous ("Which plate, North or South?") Perhaps future textbook authors could call it the "Two-American Plate." Textbook authors ultimately decide such global-tectonic matters. I became aware of textbook authors' opinions and influence from my research into the history of Alfred Wegener's continental drift (see Fixists vs. Mobilists by Krill 2011). Leading textbook author Charles Schuchert realized that continental drift would abolish his cherished paleogeographic models of large east-west continents (Eria, Gondwana) and small oceans (Poseiden, Nereis). He and his junior coauthors conspired to keep drift evidence out of their textbooks, from the 1934-editions until the 1969-editions (Physical Geology by Longwell et al. 1969, Historical Geology by Dunbar & Waage 1969). Their textbooks ruled in America. Textbooks

  10. Historical genomics of North American maize

    NARCIS (Netherlands)

    Heerwaarden, van J.; Hufford, M.B.; Ross-Ibarra, J.

    2012-01-01

    Since the advent of modern plant breeding in the 1930s, North American maize has undergone a dramatic adaptation to high-input agriculture. Despite the importance of genetic contributions to historical yield increases, little is known about the underlying genomic changes. Here we use high-density

  11. North American trade growth continued in 2007

    Science.gov (United States)

    2009-02-01

    Trade between the United States and its North American Free Trade Agreement (NAFTA) partnersCanada and Mexicohas more than doubled in dollar value since the inception of NAFTA in 1994. In 2007, U.S. trade with Canada and Mexico reached $909 bil...

  12. Carbon fluxes on North American rangelands

    Science.gov (United States)

    Tony Svejcar; Raymond Angell; James A. Bradford; William Dugas; William Emmerich; Albert B. Frank; Tagir Gilmanov; Marshall Haferkamp; Douglas A. Johnson; Herman Mayeux; Pat Mielnick; Jack Morgan; Nicanor Z. Saliendra; Gerald E. Schuman; Phillip L. Sims; Kereith Snyder

    2008-01-01

    Rangelands account for almost half of the earth's land surface and may play an important role in the global carbon (C) cycle. We studied net ecosystem exchange (NEE) of C on eight North American rangeland sites over a 6-yr period. Management practices and disturbance regimes can influence NEE; for consistency, we compared ungrazed and undisturbed rangelands...

  13. West Nile virus: North American experience

    Science.gov (United States)

    Hofmeister, Erik K.

    2011-01-01

    West Nile virus, a mosquito-vectored flavivirus of the Japanese encephalitis serogroup, was first detected in North America following an epizootic in the New York City area in 1999. In the intervening 11 years since the arrival of the virus in North America, it has crossed the contiguous USA, entered the Canadian provinces bordering the USA, and has been reported in the Caribbean islands, Mexico, Central America and, more recently, South America. West Nile virus has been reported in over 300 species of birds in the USA and has caused the deaths of thousands of birds, local population declines of some avian species, the clinical illness and deaths of thousands of domestic horses, and the clinical disease in over 30 000 Americans and the deaths of over 1000. Prior to the emergence of West Nile virus in North America, St. Louis encephalitis virus and Dengue virus were the only other known mosquito-transmitted flaviviruses in North America capable of causing human disease. This review will discuss the North American experience with mosquito-borne flavivirus prior to the arrival of West Nile virus, the entry and spread of West Nile virus in North America, effects on wild bird populations, genetic changes in the virus, and the current state of West Nile virus transmission.

  14. Origin of tropical American burrowing reptiles by transatlantic rafting.

    Science.gov (United States)

    Vidal, Nicolas; Azvolinsky, Anna; Cruaud, Corinne; Hedges, S Blair

    2008-02-23

    Populations of terrestrial or freshwater taxa that are separated by oceans can be explained by either oceanic dispersal or fragmentation of a previously contiguous land mass. Amphisbaenians, the worm lizards (approx. 165 species), are small squamate reptiles that are uniquely adapted to a burrowing lifestyle and inhabit Africa, South America, Caribbean Islands, North America, Europe and the Middle East. All but a few species are limbless and they rarely leave their subterranean burrows. Given their peculiar habits, the distribution of amphisbaenians has been assumed to be primarily the result of two land-mass fragmentation events: the split of the supercontinent Pangaea starting 200 Myr ago, separating species on the northern land mass (Laurasia) from those on the southern land mass (Gondwana), and the split of South America from Africa 100 Myr ago. Here we show with molecular evidence that oceanic dispersal-on floating islands-played a more prominent role, and that amphisbaenians crossed the Atlantic Ocean in the Eocene (40 Myr ago) resulting in a tropical American radiation representing one-half of all known amphisbaenian species. Until now, only four or five transatlantic dispersal events were known in terrestrial vertebrates. Significantly, this is the first such dispersal event to involve a group that burrows, an unexpected lifestyle for an oceanic disperser.

  15. Contributions of Tropical Cyclones to the North Atlantic Climatological Rainfall as Observed from Satellites

    Science.gov (United States)

    Rodgers, Edward B.; Adler, Robert F.; Pierce, Harold F.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The tropical cyclone rainfall climatology study that was performed for the North Pacific was extended to the North Atlantic. Similar to the North Pacific tropical cyclone study, mean monthly rainfall within 444 km of the center of the North Atlantic tropical cyclones (i.e., that reached storm stage and greater) was estimated from passive microwave satellite observations during, an eleven year period. These satellite-observed rainfall estimates were used to assess the impact of tropical cyclone rainfall in altering the geographical, seasonal, and inter-annual distribution of the North Atlantic total rainfall during, June-November when tropical cyclones were most abundant. The main results from this study indicate: 1) that tropical cyclones contribute, respectively, 4%, 3%, and 4% to the western, eastern, and entire North Atlantic; 2) similar to that observed in the North Pacific, the maximum in North Atlantic tropical cyclone rainfall is approximately 5 - 10 deg poleward (depending on longitude) of the maximum non-tropical cyclone rainfall; 3) tropical cyclones contribute regionally a maximum of 30% of the total rainfall 'northeast of Puerto Rico, within a region near 15 deg N 55 deg W, and off the west coast of Africa; 4) there is no lag between the months with maximum tropical cyclone rainfall and non-tropical cyclone rainfall in the western North Atlantic, while in the eastern North Atlantic, maximum tropical cyclone rainfall precedes maximum non-tropical cyclone rainfall; 5) like the North Pacific, North Atlantic tropical cyclones Of hurricane intensity generate the greatest amount of rainfall in the higher latitudes; and 6) warm ENSO events inhibit tropical cyclone rainfall.

  16. Reconstruction of the North Atlantic tropical cyclones in Azores for the last 800 years.

    Science.gov (United States)

    Rubio-Ingles, Maria Jesus; Sánchez, Guiomar; Trigo, Ricardo; Francus, Pierre; Gonçalves, Vitor; Raposeiro, Pedro; Freitas, Conceiçao; Borges, Paolo; Hernández, Armand; Bao, Roberto; Vázquez-Loureiro, David; Andrade, Cesar; Sáez, Alberto; Giralt, Santiago

    2014-05-01

    The variability of North Atlantic tropical storms has been the focus of several studies. Duration and seasonality has been attributed to a number of climate patterns and processes such as El Niño-Southern Oscillation, Atlantic Meridional Mode, African easterly waves, and atmospheric Rossby waves, but their tracks have been widely related to the North Atlantic Oscillation. Several authors have pointed out an increase and track shifting of North Atlantic tropical cyclones since 1995 with increased probability of these turning north far away from the North American continent. However, this cannot be regarded as an infrequent phenomenon as most proxy records from the Atlantic North have shown the existence of similar patterns in the past. Sao Miguel Island (Azores archipelago, Portugal) is settled in the middle of the Atlantic Ocean. This location makes this island an excellent natural laboratory to record shifts on North Atlantic tropical storms tracks that can reach the archipelago as low intensity hurricanes (e.g. Nadine in 2012) or downgraded to tropical storm (e.g. Grace in 2009). In the present work, lake sediment records have been used as a proxy sensor of tropical storms. Lagoa Azul is located inside Sete Cidades volcanic caldera and its catchment is characterized by stepped and forested caldera walls. Tropical storms and heavy rainfalls produce a flashy and substantial enhancement in the erosion of the catchment, increasing the sediments reaching the lake by rockfalls deposits (in littoral zones) and flood events deposits (in offshore zones). These flood events can be recognized in the sedimentary record as lobe deposits dominated by terrestrial components. It can be found in the sedimentary record and the bathymetry. Instrumental meteorological data and historical records have been compiled to reconstruct the most recent history of the North Atlantic tropical storms that have landed or affected the Sao Miguel Island (Andrade et al., 2008). In addition, a 1

  17. North American natural gas supply and demand

    International Nuclear Information System (INIS)

    Goobie, G.

    2006-01-01

    This presentation was given by leading energy analysts Pervin and Gertz, and provided their outlook on the North American natural gas supply and demand as well as transportation and processing options for the Mackenzie Valley project and the Alaska natural gas project. Arctic gas development was discussed in relation to larger North American and world energy markets. The impacts of liquefied natural gas (LNG) infrastructure development were compared with the potential impacts of the Alaska and Mackenzie Valley pipelines. A review of North American gas supplies was presented. LNG imports to the United States are expected to exceed 8 BCF/D by 2010. In addition, huge growth in the LNG markets is expected in middle eastern countries as well as in Africa. There is currently strong growth in liquefaction capacity in most regions. However, many proposed LNG terminals will not proceed due to opposition on the west coast of North America. It is also expected that natural gas liquids (NGL) delivered to Alberta from the Mackenzie Valley Gas project are expected to be used by the heavy oil industry. Canadian crude supplies are expected to grow to nearly 4 million barrels per day by 2015. The impacts of Alaska and Mackenzie Valley gas projects on western NGL markets and the petrochemicals industry were reviewed. It was concluded that major investments in supply and infrastructure are need in order to develop Arctic gas, as LNG is likely to be the largest source of incremental supply. tabs., figs

  18. Chronic liver disease in Aboriginal North Americans

    Institute of Scientific and Technical Information of China (English)

    John D Scott; Naomi Garland

    2008-01-01

    A structured literature review was performed to detail the frequency and etiology of chronic liver disease (CLD) in Aboriginal North Americans. CLD affects Aboriginal North Americans disproportionately and is now one of the most common causes of death.Alcoholic liver disease is the leading etiology of CLD,but viral hepatitis, particularly hepatitis C, is an important and growing cause of CLD. High rates of autoimmune hepatitis and primary biliary cirrhosis (PBC) are reported in regions of coastal British Columbia and southeastern Alaska. Non-alcoholic liver disease is a common, but understudied, cause of CLD.Future research should monitor the incidence and etiology of CLD and should be geographically inclusive.In addition, more research is needed on the treatment of hepatitis C virus (HCV) infection and non-alcoholicfatty liver disease (NAFLD) in this population.

  19. Presumptive fenbendazole toxicosis in North American porcupines.

    Science.gov (United States)

    Weber, Martha A; Miller, Michele A; Neiffer, Donald L; Terrell, Scott P

    2006-04-15

    4 North American porcupines were evaluated because of diarrhea or neutropenia (or both) that developed after treatment with fenbendazole for intestinal parasites. Complete blood cell count abnormalities included severe neutropenia in all affected porcupines and mild anemia in some of them. In 2 porcupines, postmortem findings included bone marrow hypoplasia and intestinal crypt cell necrosis. Affected porcupines received supportive care including fluid supplementation and broad-spectrum antimicrobials. The 2 surviving animals recovered after 9 to 33 days of treatment. Fenbendazole is an anthelminthic that may be used in an extralabel manner for the treatment of intestinal parasitism in wildlife species. The drug inhibits mitosis and can affect rapidly dividing cell lines, such as those in the bone marrow and intestinal crypt mucosa. Fenbendazole may not be an appropriate anthelminthic choice in North American porcupines.

  20. Ocean-atmosphere forcing of South American tropical paleoclimate, LGM to present

    Science.gov (United States)

    Baker, P. A.; Fritz, S. C.; Dwyer, G. S.; Rigsby, C. A.; Silva, C. G.; Burns, S. J.

    2012-12-01

    Because of many recent terrestrial paleoclimatic and marine paleoceanographic records, late Quaternary South American tropical paleoclimate is as well understood as that anywhere in the world. While lessons learned from the recent instrumental record of climate are informative, this record is too short to capture much of the lower frequency variability encountered in the paleoclimate records and much of the observed paleoclimate is without modern analogue. This paleoclimate is known to be regionally variable with significant differences both north and south of the equator and between the western high Andes and eastern lowlands of the Amazon and Nordeste Brazil. Various extrinsic forcing mechanisms affected climate throughout the period, including global concentrations of GHGs, Northern Hemisphere ice sheet forcing, seasonal insolation forcing of the South American summer monsoon (SASM), millennial-scale Atlantic forcing, and Pacific forcing of the large-scale Walker circulation. The magnitude of the climate response to these forcings varied temporally, largely because of the varying amplitude of the forcing itself. For example, during the last glacial, large-amplitude north Atlantic forcing during Heinrich 1 and the LGM itself, led to wet (dry) conditions south (north) of the equator. During the Holocene, Atlantic forcing was lower amplitude, thus seasonal insolation forcing generally predominated with a weaker-than-normal SASM during the early Holocene resulting in dry conditions in the south-western tropics and wet conditions in the eastern lowlands and Nordeste; in the late Holocene seasonal insolation reached a maximum in the southern tropics and climate conditions reversed.

  1. North-American MP Tandem accelerators

    International Nuclear Information System (INIS)

    Wegner, H.E.; Thieberger, P.

    1977-01-01

    There are six North-American MP Tandem accelerators: Yale; Minnesota; Chalk River; Rochester; and two at Brookhaven. The current status and operating characteristics of these six tandem accelerators are discussed. Upgrade and special improvements of the different machines is reviewed and new developments since the last Electrostatic Conference are discussed in detail. The overall operating characteristics of the different machines during the last year of operation are compared

  2. 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.

  3. Tropical North Atlantic ocean-atmosphere interactions synchronize forest carbon losses from hurricanes and Amazon fires

    Science.gov (United States)

    Chen, Yang; Randerson, James T.; Morton, Douglas C.

    2015-08-01

    We describe a climate mode synchronizing forest carbon losses from North and South America by analyzing time series of tropical North Atlantic sea surface temperatures (SSTs), landfall hurricanes and tropical storms, and Amazon fires during 1995-2013. Years with anomalously high tropical North Atlantic SSTs during March-June were often followed by a more active hurricane season and a larger number of satellite-detected fires in the southern Amazon during June-November. The relationship between North Atlantic tropical cyclones and southern Amazon fires (r = 0.61, p forests.

  4. In North American energy markets : stronger credibility

    International Nuclear Information System (INIS)

    Lefevre, M.

    1997-01-01

    Hydro-Quebec''s competitive position as it expands and diversifies its business in the future was discussed. The utility has an outstanding debt of CAN$37 billion, nevertheless, it is considered to be a solid investment by financial experts. Hydro-Quebec is recognized as North America''s biggest electric utility in terms of sales and also has the lowest cost structure on the continent. Moody Investor Services, Duff and Phelps Credit Rating Co., and Standard and Poor, have recently conducted ratings of the utility''s standing on financial markets. Hydro-Quebec maintained their high ratings, of A2, AA-, and A+ respectively. The restructuring of North American electricity market gives Hydro-Quebec substantial growth potential. The utility has an extensive transmission network and can offer reasonable electricity rates

  5. Integration of the North American energy market

    International Nuclear Information System (INIS)

    Lapointe, A.

    2002-07-01

    The US energy policy of President Bush administration proposes to develop a North American energy framework with a greater energy integration between Canada, the USA and Mexico in the respect of the sovereignty of each country. This article tries to evaluate the integration status of the energy sector in Northern America with respect to the North American free-exchange agreement and to the deregulation process observed in the natural gas and electric power sectors. The commercial energy fluxes between Canada, Mexico and the US show that the integration is a reality and that it is in constant progress. This integration is particularly important in the case of Canada and the USA while major constraints remain in Mexico where the property and exploitation of natural resources is a government monopoly. For this reason, Mexico could never exploit the full potentialities of its resources and suffers from a chronical under-investment in its energy infrastructures which limits the energy trade. Despite this, there is a strong will from the Mexican authorities to ensure the modernization of its energy sector and to contribute more to the integration process of the north American energy market. A series of reforms, and in particular the fiscal reform started by the government should reduce the excessive dependence of the government incomes with the dividends from the energy sector. This should allow the different government companies to reinvest more its benefits in order to improve the existing infrastructures and to increase the capacities (in particular in the gas and electricity sectors). Finally, the recent will of the government to open the gas sector should allow the development of this energy source. (J.S.)

  6. Overview of North American Hydrogen Sensor Standards

    Energy Technology Data Exchange (ETDEWEB)

    O' Malley, Kathleen [SRA International, Inc., Colorado Springs, CO (United States); Lopez, Hugo [UL LLC, Chicago, IL (United States); Cairns, Julie [CSA Group, Cleveland, OH (United States); Wichert, Richard [Professional Engineering, Inc.. Citrus Heights, CA (United States); Rivkin, Carl [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Burgess, Robert [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Buttner, William [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2015-08-11

    An overview of the main North American codes and standards associated with hydrogen safety sensors is provided. The distinction between a code and a standard is defined, and the relationship between standards and codes is clarified, especially for those circumstances where a standard or a certification requirement is explicitly referenced within a code. The report identifies three main types of standards commonly applied to hydrogen sensors (interface and controls standards, shock and hazard standards, and performance-based standards). The certification process and a list and description of the main standards and model codes associated with the use of hydrogen safety sensors in hydrogen infrastructure are presented.

  7. North American Natural Gas Markets. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    1989-02-01

    This report summarizes die research by an Energy Modeling Forum working group on the evolution of the North American natural gas markets between now and 2010. The group`s findings are based partly on the results of a set of economic models of the natural gas industry that were run for four scenarios representing significantly different conditions: two oil price scenarios (upper and lower), a smaller total US resource base (low US resource case), and increased potential gas demand for electric generation (high US demand case). Several issues, such as the direction of regulatory policy and the size of the gas resource base, were analyzed separately without the use of models.

  8. Precision Rescue Behavior in North American Ants

    Directory of Open Access Journals (Sweden)

    Katherine Taylor

    2013-07-01

    Full Text Available Altruistic behavior, in which one individual provides aid to another at some cost to itself, is well documented. However, some species engage in a form of altruism, called rescue, that places the altruist in immediate danger. Here we investigate one such example, namely rescuing victims captured by predators. In a field experiment with two North American ant species, Tetramorium sp. E and Prenolepis imparis, individuals were held in artificial snares simulating capture. T. sp. E, but not P. imparis, exhibited digging, pulling, and snare biting, the latter precisely targeted to the object binding the victim. These results are the first to document precision rescue in a North American ant species; moreover, unlike rescue in other ants, T. sp. E rescues conspecifics from different colonies, mirroring their atypical social behavior, namely the lack of aggression between non-nestmate (heterocolonial conspecifics. In a second, observational study designed to demonstrate rescue from an actual predator, T. sp. E victims were dropped into an antlion's pit and the behavior of a single rescuer was observed. Results showed that T. sp. E not only attempted to release the victim, but also risked attacking the predator, suggesting that precision rescue may play an important role in this species' antipredator behavior.

  9. The Variation of Tropical Cyclone Rainfall within the North Atlantic and Pacific as Observed from Satellites

    Science.gov (United States)

    Rodgers, Edward; Pierce, Harold; Adler, Robert

    1999-01-01

    Tropical cyclone monthly rainfall amounts are estimated from passive microwave satellite observations in the North Atlantic and in three equal geographical regions of the North Pacific (i.e., Western, Central, and Eastern North Pacific). These satellite-derived rainfall amounts are used to assess the impact of tropical cyclone rainfall in altering the geographical, seasonal, and inter-annual distribution of the 1987-1989, 1991-1998 North Atlantic and Pacific rainfall during June-November when tropical cyclones are most abundant. To estimate these tropical cyclone rainfall amounts, mean monthly rain rates are derived from the Defence Meteorological Satellite Program (DMSP) Special Sensor Microwave/ Radiometer (SSM/I) observations within 444 km radius of the center of those North Atlantic and Pacific tropical cyclones that reached storm stage and greater. These rain rate observations are then multiplied by the number of hours in a given month. Mean monthly rainfall amounts are also constructed for all the other North Atlantic and Pacific raining systems during this eleven year period for the purpose of estimating the geographical distribution and intensity of rainfall contributed by non-tropical cyclone systems. Further, the combination of the non-tropical cyclone and tropical cyclone (i.e., total) rainfall is constructed to delineate the fractional amount that tropical cyclones contributed to the total North Pacific rainfall.

  10. Propane supply picture: North American perspective

    International Nuclear Information System (INIS)

    Horner, N.

    1992-01-01

    An overview is presented of the North American propane supply and demand situation. Propane has a distribution network in place and a well established market. North America is virtually self-sufficient in propane with a market of over 1,000,000 bbl/d. Approximately 80% of Canada's propane supply is produced at gas plants in western Canada as a byproduct of natural gas production. The expansion in natural gas markets will mean that propane supply will rise further, unlike crude oil. Canada's daily supply of nearly 160,000 bbl is used for heating (30%), transport (12%), petrochemicals (7.8%), and enhanced oil recovery (4.7%), with the remainder being exported. Propane surpluses are expected to grow, between 70,000 and 100,000 bbl/d in the next 5 years. Nearly 30% of North America's demand for propane is in the petrochemical industry, for which various other feedstocks can be substituted. An availability of over 400,000 bbl/d could fuel ca 5 million vehicles. Only natural gas has a comparable infrastructure and this suffers from high utilization pressure and poor energy density. Wholesale propane is now available at under 9 cents/liter, significantly below the projected ethanol price of 18 cents/liter, which excludes grain feedstock or capital cost. 8 refs., 6 figs

  11. Transport and Thermohaline Structure in the Western Tropical North Pacific

    Science.gov (United States)

    Schonau, Martha Coakley

    Transport and thermohaline structure of water masses and their respective variability are observed and modeled in the western tropical North Pacific using autonomous underwater gliders, Argo climatology and a numerical ocean state estimate. The North Equatorial Current (NEC) advects subtropical and subpolar water masses into the region that are transported equatorward by the Mindanao Current (MC). Continuous glider observations of these two currents from June 2009 to December 2013 provide absolute geostrophic velocity, water mass structure, and transport. The observations are compared to Argo climatology (Roemmich and Gilson, 2009), wind and precipitation to assess forcing, and annual and interannual variability. Observations are assimilated into a regional ocean state estimate (1/6°) to examine regional transport variability and its relationship to the El Nino-Southern Oscillation phenomena (ENSO). The NEC, described in Chapter 1, is observed along 134.3°E, from 8.5°N to 16.5°N. NEC thermocline transport is relatively constant, with a variable subthermocline transport that is distinguished by countercurrents centered at 9.6°N and 13.1°N. Correlation between thermocline and subthermocline transport is strong. Isopycnals with subducted water masses, the North Pacific Tropical Water and North Pacific Intermediate Water, have the greatest fine-scale thermohaline variance. The NEC advects water masses into the MC, described in Chapter 2, that flows equatorward along the coast of Mindanao. Gliders observed the MC at a mean latitude of 8.5°N. The Mindanao Undercurrent (MUC) persists in the subthermocline offshore of the MC, with a net poleward transport of intermediate water typical of South Pacific origin. The variable subthermocline transport in the MC/MUC has an inverse linear relationship with the Nino 3.4 index and strongly impacts total transport variability. For each the MC and NEC, surface salinity and thermocline depth have a strong relationship with ENSO

  12. North American box turtles: A natural history

    Science.gov (United States)

    Dodd, C. Kenneth

    2002-01-01

    Once a familiar backyard visitor in many parts of the United States and Mexico, the box turtle is losing the battle against extinction. In North American Box Turtles, C. Kenneth Dodd, Jr., has written the first book-length natural history of the twelve species and subspecies of this endangered animal. This volume includes comprehensive information on the species’ evolution, behavior, courtship and reproduction, habitat use, diet, population structure, systematics, and disease. Special features include color photos of all species, subspecies, and their habitats; a simple identification guide to both living and fossil species; and a summary of information on fossil Terrapene and Native uses of box turtles. End-of-chapter sections highlight future research directions, including the need for long-term monitoring and observation of box turtles within their natural habitat and conservation applications. A glossary and a bibliography of literature on box turtles accompany the text.

  13. North American Integration after 20 Years

    Directory of Open Access Journals (Sweden)

    Galina M. Kostyunina

    2015-01-01

    Full Text Available Formation of the North American Free Trade Area (NAFTA among the three countries - the U.S., Canada and Mexico is the most striking example of successful development of integration processes in the Western Hemisphere. This year NAFTA marks the 20th anniversary of its foundation (1994. NAFTA covers trade in goods, services and movement of capital, intellectual property rights, environmental cooperation and labor cooperation. Its main advantages for member countries related to the dynamic growth of regional trade and investments, promoting the growth of industrial production (capital-intensive and high-tech industries in the U.S. and Canada, and labor-intensive industries in Mexico, increase the investment attractiveness of the economies of member countries and the promotion of employment. But there are costs, both general and specific to the individual member countries. Common costs are primarily asymmetrical level of economic interdependence, where mutual economic relations are the most developed between the U.S. and Canada, the U.S. and Mexico, and the least developed between Mexico and Canada due to historical conditions. Other costs are the differentiation in the levels of economic development, in volumes of overall GDP and per capita, population and size of the territory. But despite the costs, integration processes are successfully developed and repeatedly raised the issue of deepening economic integration between the U.S., Canada and Mexico. So, in 2000, there was put forward the concept of creating the North American community as an economic and security community by 2010, and in 2005 proposed the idea of a common currency called the Amero. But these proposals did not come true. On the agenda - the possibility of signing a new, more expanded NAFTA+, and even in the last year - the possibility to form a customs union under NAFTA.

  14. 2005 the North American Solar Challenge

    Energy Technology Data Exchange (ETDEWEB)

    Dan Eberle

    2008-12-22

    In July 2005 the North American Solar Challenge (NASC) featured university built solar powered cars ran across the United States into Canada. The competition began in Austin, Texas with stops in Weatherford, Texas; Broken Arrow, Oklahoma; Topeka, Kansas; Omaha, Nebraska; Sioux Falls, South Dakota, Fargo, North Dakota; Winnipeg, Manitoba; Brandon, Manitoba; Regina, Saskatchewan; Medicine Hat, Alberta; mainly following U.S. Highway 75 and Canadian Highway 1 to the finish line in Calgary, Alberta, Canada, for a total distance of 2,500 miles. NASC major sponsors include the U.S. Department of Energy (DOE), Natural Resources Canada and DOEs National Renewable Energy Laboratory. The event is designed to inspire young people to pursue careers in science and engineering. NASCs predecessors, the American Solar Challenge and Sunrayce, generally have been held every two years since 1990. With each race, the solar cars travel faster and further with greater reliability. The NASC promotes: -Renewable energy technologies (specifically photovoltaic or solar cells) -Educational excellence in science, engineering and mathematics -Creative integration of technical and scientific expertise across a wide-range of disciplines -Hands-on experience for students and engineers to develop and demonstrate their technical and creative abilities. Safety is the first priority for the NASC. Each team put its car through grueling qualifying and technical inspections. Teams that failed to meet the requirements were not allowed participate. During the race, each team was escorted by lead and chase vehicles sporting rooftop hazard flashers. An official observer accompanied each solar car team to keep it alert to any safety issues.

  15. Training on Eastern Pacific tropical cyclones for Latin American students

    Science.gov (United States)

    Farfán, L. M.; Raga, G. B.

    2009-05-01

    Tropical cyclones are one of the most impressive atmospheric phenomena and their development in the Atlantic and Eastern Pacific basins has potential to affect several Latin-American and Caribbean countries, where human resources are limited. As part of an international research project, we are offering short courses based on the current understanding of tropical cyclones in the Eastern Pacific basin. Our main goal is to train students from higher-education institutions from various countries in Latin America. Key aspects are tropical cyclone formation and evolution, with particular emphasis on their development off the west coast of Mexico. Our approach includes lectures on tropical cyclone climatology and formation, dynamic and thermodynamic models, air-sea interaction and oceanic response, ocean waves and coastal impacts as well as variability and climate-related predictions. In particular, we use a best-track dataset issued by the United States National Hurricane Center and satellite observations to analyze convective patterns for the period 1970-2006. Case studies that resulted in landfall over northwestern Mexico are analyzed in more detail; this includes systems that developed during the 2006, 2007 and 2008 seasons. Additionally, we have organized a human-dimensions symposium to discuss socio-economic issues that are associated with the landfall of tropical cyclones. This includes coastal zone impact and flooding, the link between cyclones and water resources, the flow of weather and climate information from scientists to policy- makers, the role of emergency managers and decision makers, impact over health issues and the viewpoint of the insurance industry.

  16. Pain education in North American medical schools.

    Science.gov (United States)

    Mezei, Lina; Murinson, Beth B

    2011-12-01

    Knowledgeable and compassionate care regarding pain is a core responsibility of health professionals associated with better medical outcomes, improved quality of life, and lower healthcare costs. Education is an essential part of training healthcare providers to deliver conscientious pain care but little is known about whether medical school curricula meet educational needs. Using a novel systematic approach to assess educational content, we examined the curricula of Liaison Committee on Medical Education-accredited medical schools between August 2009 and February 2010. Our intent was to establish important benchmark values regarding pain education of future physicians during primary professional training. External validation was performed. Inclusion criteria required evidence of substantive participation in the curriculum management database of the Association of American Medical Colleges. A total of 117 U.S. and Canadian medical schools were included in the study. Approximately 80% of U.S. medical schools require 1 or more pain sessions. Among Canadian medical schools, 92% require pain sessions. Pain sessions are typically presented as part of general required courses. Median hours of instruction on pain topics for Canadian schools was twice the U.S. median. Many topics included in the International Association for the Study of Pain core curriculum received little or no coverage. There were no correlations between the types of pain education offered and school characteristics (eg, private versus public). We conclude that pain education for North American medical students is limited, variable, and often fragmentary. There is a need for innovative approaches and better integration of pain topics into medical school curricula. This study assessed the scope and scale of pain education programs in U.S. and Canadian medical schools. Significant gaps between recommended pain curricula and documented educational content were identified. In short, pain education was

  17. Knowledge Organisation Systems in North American Digital Library Collections

    Science.gov (United States)

    Shiri, Ali; Chase-Kruszewski, Sarah

    2009-01-01

    Purpose: The purpose of this paper is to report an investigation into the types of knowledge organisation systems (KOSs) utilised in North American digital library collections. Design/methodology/approach: The paper identifies, analyses and deep scans online North American hosted digital libraries. It reviews the literature related to the…

  18. Investigators share improved understanding of the North American carbon cycle

    Science.gov (United States)

    Richard A. Birdsey; Robert Cook; Scott Denning; Peter Griffith; Beverly Law; Jeffrey Masek; Anna Michalak; Stephen Ogle; Dennis Ojima; Yude Pan; Christopher Sabine; Edwin Sheffner; Eric Sundquist

    2007-01-01

    The U.S. North American Carbon Program (NACP) sponsored an "all-scientist" meeting to review progress in understanding the dynamics of the carbon cycle of North American and adjacent oceans, and to chart a course for improved integration across scientifi c disciplines, scales, and Earth system boundaries. The meeting participants also addressed the need for...

  19. Contribution of Tropical Cyclones to the North Pacific Climatological Rainfall as Observed from Satellites.

    Science.gov (United States)

    Rodgers, Edward B.; Adler, Robert F.; Pierce, Harold F.

    2000-10-01

    Tropical cyclone monthly rainfall amounts are estimated from passive microwave satellite observations for an 11-yr period. These satellite-derived rainfall amounts are used to assess the impact of tropical cyclone rainfall in altering the geographical, seasonal, and interannual distribution of the North Pacific Ocean total rainfall during June-November when tropical cyclones are most important.To estimate these tropical cyclone rainfall amounts, mean monthly rain rates are derived from passive microwave satellite observations within 444-km radius of the center of those North Pacific tropical cyclones that reached storm stage and greater. These rain-rate observations are converted to monthly rainfall amounts and then compared with those for nontropical cyclone systems.The main results of this study indicate that 1) tropical cyclones contribute 7% of the rainfall to the entire domain of the North Pacific during the tropical cyclone season and 12%, 3%, and 4% when the study area is limited to, respectively, the western, central, and eastern third of the ocean; 2) the maximum tropical cyclone rainfall is poleward (5°-10° latitude depending on longitude) of the maximum nontropical cyclone rainfall; 3) tropical cyclones contribute a maximum of 30% northeast of the Philippine Islands and 40% off the lower Baja California coast; 4) in the western North Pacific, the tropical cyclone rainfall lags the total rainfall by approximately two months and shows seasonal latitudinal variation following the Intertropical Convergence Zone; and 5) in general, tropical cyclone rainfall is enhanced during the El Niño years by warm SSTs in the eastern North Pacific and by the monsoon trough in the western and central North Pacific.

  20. The outlook for North American supply

    International Nuclear Information System (INIS)

    Coppens, J.

    1998-01-01

    An overview of North American natural gas assets and operations is presented, along with an outlook for natural gas demand, supply, and prices. Future natural gas demand was considered in the light of 1997 natural gas consumption by the residential, commercial, industrial and utility sectors, and an attempt was made to provide answers to questions such as the reasonableness of projections 30 Tcf annual demand, and the availability of gas resources or gas infrastructure to sustain demand of this magnitude. According to projections by the Electric Industry Association, 65 per cent of gas demand growth is for electric power generation. Natural gas supply on a regional and continental basis was reviewed and the implications for production were assessed. The overall conclusion was that resource supply will not be the constraining factor since there is plenty of gas, and the demand is regionally dispersed. However, if the demand for power generation comes anywhere near the high consumption forecast of 100 to 150 GW, a huge amount of gas-fired power plants would have to be built. Expansion of this magnitude would not be inexpensive

  1. Incidental oligotrophication of North American Great Lakes.

    Science.gov (United States)

    Evans, Mary Anne; Fahnenstiel, Gary; Scavia, Donald

    2011-04-15

    Phytoplankton production is an important factor in determining both ecosystem stability and the provision of ecosystem goods and services. The expansive and economically important North American Great Lakes are subjected to multiple stressors and understanding their responses to those stresses is important for understanding system-wide ecological controls. Here we show gradual increases in spring silica concentration (an indicator of decreasing growth of the dominant diatoms) in all basins of Lakes Michigan and Huron (USA and Canadian waters) between 1983 and 2008. These changes indicate the lakes have undergone gradual oligotrophication coincident with and anticipated by nutrient management implementation. Slow declines in seasonal drawdown of silica (proxy for seasonal phytoplankton production) also occurred, until recent years, when lake-wide responses were punctuated by abrupt decreases, putting them in the range of oligotrophic Lake Superior. The timing of these dramatic production drops is coincident with expansion of populations of invasive dreissenid mussels, particularly quagga mussels, in each basin. The combined effect of nutrient mitigation and invasive species expansion demonstrates the challenges facing large-scale ecosystems and suggest the need for new management regimes for large ecosystems.

  2. Species longevity in North American fossil mammals.

    Science.gov (United States)

    Prothero, Donald R

    2014-08-01

    Species longevity in the fossil record is related to many paleoecological variables and is important to macroevolutionary studies, yet there are very few reliable data on average species durations in Cenozoic fossil mammals. Many of the online databases (such as the Paleobiology Database) use only genera of North American Cenozoic mammals and there are severe problems because key groups (e.g. camels, oreodonts, pronghorns and proboscideans) have no reliable updated taxonomy, with many invalid genera and species and/or many undescribed genera and species. Most of the published datasets yield species duration estimates of approximately 2.3-4.3 Myr for larger mammals, with small mammals tending to have shorter species durations. My own compilation of all the valid species durations in families with updated taxonomy (39 families, containing 431 genera and 998 species, averaging 2.3 species per genus) yields a mean duration of 3.21 Myr for larger mammals. This breaks down to 4.10-4.39 Myr for artiodactyls, 3.14-3.31 Myr for perissodactyls and 2.63-2.95 Myr for carnivorous mammals (carnivorans plus creodonts). These averages are based on a much larger, more robust dataset than most previous estimates, so they should be more reliable for any studies that need species longevity to be accurately estimated. © 2013 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

  3. Oceanography. Centennial changes in North Pacific anoxia linked to tropical trade winds.

    Science.gov (United States)

    Deutsch, Curtis; Berelson, William; Thunell, Robert; Weber, Thomas; Tems, Caitlin; McManus, James; Crusius, John; Ito, Taka; Baumgartner, Timothy; Ferreira, Vicente; Mey, Jacob; van Geen, Alexander

    2014-08-08

    Climate warming is expected to reduce oxygen (O2) supply to the ocean and expand its oxygen minimum zones (OMZs). We reconstructed variations in the extent of North Pacific anoxia since 1850 using a geochemical proxy for denitrification (δ(15)N) from multiple sediment cores. Increasing δ(15)N since ~1990 records an expansion of anoxia, consistent with observed O2 trends. However, this was preceded by a longer declining δ(15)N trend that implies that the anoxic zone was shrinking for most of the 20th century. Both periods can be explained by changes in winds over the tropical Pacific that drive upwelling, biological productivity, and O2 demand within the OMZ. If equatorial Pacific winds resume their predicted weakening trend, the ocean's largest anoxic zone will contract despite a global O2 decline. Copyright © 2014, American Association for the Advancement of Science.

  4. Ammonia and nitrite oxidation in the Eastern Tropical North Pacific

    Science.gov (United States)

    Peng, Xuefeng; Fuchsman, Clara A.; Jayakumar, Amal; Oleynik, Sergey; Martens-Habbena, Willm; Devol, Allan H.; Ward, Bess B.

    2015-12-01

    Nitrification plays a key role in the marine nitrogen (N) cycle, including in oceanic oxygen minimum zones (OMZs), which are hot spots for denitrification and anaerobic ammonia oxidation (anammox). Recent evidence suggests that nitrification links the source (remineralized organic matter) and sink (denitrification and anammox) of fixed N directly in the steep oxycline in the OMZs. We performed shipboard incubations with 15N tracers to characterize the depth distribution of nitrification in the Eastern Tropical North Pacific (ETNP). Additional experiments were conducted to investigate photoinhibition. Allylthiourea (ATU) was used to distinguish the contribution of archaeal and bacterial ammonia oxidation. The abundance of archaeal and β-proteobacterial ammonia monooxygenase gene subunit A (amoA) was determined by quantitative polymerase chain reaction. The rates of ammonia and nitrite oxidation showed distinct subsurface maxima, with the latter slightly deeper than the former. The ammonia oxidation maximum coincided with the primary nitrite concentration maximum, archaeal amoA gene maximum, and the subsurface nitrous oxide maximum. Negligible rates of ammonia oxidation were found at anoxic depths, where high rates of nitrite oxidation were measured. Archaeal amoA gene abundance was generally 1 to 2 orders of magnitude higher than bacterial amoA gene abundance, and inhibition of ammonia-oxidizing bacteria with 10 μM ATU did not affect ammonia oxidation rates, indicating the dominance of archaea in ammonia oxidation. These results depict highly dynamic activities of ammonia and nitrite oxidation in the oxycline of the ETNP OMZ.

  5. Wildlife values of North American ricelands

    Science.gov (United States)

    Eadie, J.M.; Elphick, C.S.; Reinecke, K.J.; Miller, M.R.; Manley, Scott W.

    2008-01-01

    derermining threshold food levels required to maintain bird use; (3) quantifying use of ricefields by nonwaterfowl species throughout the year; and (4) determining the amount and distribution of rice habitat needed to meet objectives of the North American Waterfowl Management Plan and the United States Shorebird Conservation Plan.

  6. Changing landscape for North American supply

    International Nuclear Information System (INIS)

    Deegan, J.

    2005-01-01

    The United States represents 29 per cent of world natural gas consumption but holds 5 per cent of world natural gas resources. Supply and demand balances in the United States were examined in this PowerPoint presentation. Issues concerning market considerations and the Energy Policy Act were reviewed. The impacts of hurricanes were assessed and the U.S. supply and demand balance for the winter of 2004-2005 was considered. Growing producer expenditures were reviewed, and average finding and development cost increases were presented. New supply sources were examined, and details of expected major domestic supply contributors by 2010 were presented by region. It was suggested that unconventional sources will play a greater role in U.S. natural gas supply, and that liquefied natural gas (LNG) will be needed to attract resources within the world market. Increased regulatory certainty and supply flexibility is essential to economical supply development decisions. Issues concerning the Federal Energy Regulatory Commission's role in LNG terminal siting were examined. Permits, taxes and royalty incentives for deep water exploration were discussed. It was suggested that the Energy Policy Act falls short on increasing access to new supply. It was observed that traditional North American producing areas will provide only 75 per cent of long-term U.S. needs. Access to multi-use, non-park, non-wilderness federal lands for gas exploration will be needed. It was concluded that non-conventional resources are more costly and face greater public resistance than conventional resource plays. tabs., figs

  7. North American Wetlands and Mosquito Control

    Science.gov (United States)

    Rey, Jorge R.; Walton, William E.; Wolfe, Roger J.; Connelly, Roxanne; O’Connell, Sheila M.; Berg, Joe; Sakolsky-Hoopes, Gabrielle E.; Laderman, Aimlee D.

    2012-01-01

    Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced by numerous factors, including many hard to quantify elements such as human perceptions, cultural predispositions, and political climate. In spite of considerable progress during the last decades, habitat protection and environmentally sound habitat management still remain inextricably tied to politics and economics. Furthermore, the connections are often complex, and occur at several levels, ranging from local businesses and politicians, to national governments and multinational institutions. Education is the key to lasting wetlands conservation. Integrated mosquito abatement strategies incorporate many approaches and practicable options, as described herein, and need to be well-defined, effective, and ecologically and economically sound for the wetland type and for the mosquito species of concern. The approach will certainly differ in response to disease outbreaks caused by mosquito-vectored pathogens versus quality of life issues caused by nuisance-biting mosquitoes. In this contribution, we provide an overview of the ecological setting and context for mosquito control in wetlands, present pertinent information on wetlands mosquitoes, review the mosquito abatement options available for current wetlands managers and mosquito control professionals, and outline some necessary considerations when devising mosquito control strategies. Although the emphasis is on North American wetlands, most of the material is applicable to wetlands everywhere. PMID:23222252

  8. The North American Amphibian Monitoring Program. [abstract

    Science.gov (United States)

    Griffin, J.

    1998-01-01

    The North American Amphibian Monitoring Program has been under development for the past three years. The monitoring strategy for NAAMP has five main prongs: terrestrial salamander surveys, calling surveys, aquatic surveys, western surveys, and atlassing. Of these five, calling surveys were selected as one of the first implementation priorities due to their friendliness to volunteers of varying knowledge levels, relative low cost, and the fact that several groups had already pioneered the techniques involved. While some states and provinces had implemented calling surveys prior to NAAMP, like WI and IL, most states and provinces had little or no history of state/provincewide amphibian monitoring. Thus, the majority of calling survey programs were initiated in the past two years. To assess the progress of this pilot phase, a program review was conducted on the status of the NAAMP calling survey program, and the results of that review will be presented at the meeting. Topics to be discussed include: who is doing what where, extent of route coverage, the continuing random route discussions, quality assurance, strengths and weaknesses of calling surveys, reliability of data, and directions for the future. In addition, a brief overview of the DISPro project will be included. DISPro is a new amphibian monitoring program in National Parks, funded by the Demonstration of Intensive Sites Program (DISPro) through the EPA and NPS. It will begin this year at Big Bend and Shenandoah National Parks. The purpose of the DISPro Amphibian Project will be to investigate relationships between environmental factors and stressors and the distribution, abundance, and health of amphibians in these National Parks. At each Park, amphibian long-term monitoring protocols will be tested, distributions and abundance of amphibians will be mapped, and field research experiments will be conducted to examine stressor effects on amphibians (e.g., ultraviolet radiation, contaminants, acidification).

  9. Changing landscape for North American supply

    Energy Technology Data Exchange (ETDEWEB)

    Deegan, J. [Natural Gas Supply Association, Washington DC (United States)

    2005-07-01

    The United States represents 29 per cent of world natural gas consumption but holds 5 per cent of world natural gas resources. Supply and demand balances in the United States were examined in this PowerPoint presentation. Issues concerning market considerations and the Energy Policy Act were reviewed. The impacts of hurricanes were assessed and the U.S. supply and demand balance for the winter of 2004-2005 was considered. Growing producer expenditures were reviewed, and average finding and development cost increases were presented. New supply sources were examined, and details of expected major domestic supply contributors by 2010 were presented by region. It was suggested that unconventional sources will play a greater role in U.S. natural gas supply, and that liquefied natural gas (LNG) will be needed to attract resources within the world market. Increased regulatory certainty and supply flexibility is essential to economical supply development decisions. Issues concerning the Federal Energy Regulatory Commission's role in LNG terminal siting were examined. Permits, taxes and royalty incentives for deep water exploration were discussed. It was suggested that the Energy Policy Act falls short on increasing access to new supply. It was observed that traditional North American producing areas will provide only 75 per cent of long-term U.S. needs. Access to multi-use, non-park, non-wilderness federal lands for gas exploration will be needed. It was concluded that non-conventional resources are more costly and face greater public resistance than conventional resource plays. tabs., figs.

  10. Environmental forcing of nitrogen fixation in the eastern tropical and sub-tropical North Atlantic Ocean.

    Science.gov (United States)

    Rijkenberg, Micha J A; Langlois, Rebecca J; Mills, Matthew M; Patey, Matthew D; Hill, Polly G; Nielsdóttir, Maria C; Compton, Tanya J; Laroche, Julie; Achterberg, Eric P

    2011-01-01

    During the winter of 2006 we measured nifH gene abundances, dinitrogen (N(2)) fixation rates and carbon fixation rates in the eastern tropical and sub-tropical North Atlantic Ocean. The dominant diazotrophic phylotypes were filamentous cyanobacteria, which may include Trichodesmium and Katagnymene, with up to 10(6) L(-1)nifH gene copies, unicellular group A cyanobacteria with up to 10(5) L(-1)nifH gene copies and gamma A proteobacteria with up to 10(4) L(-1)nifH gene copies. N(2) fixation rates were low and ranged between 0.032-1.28 nmol N L(-1) d(-1) with a mean of 0.30 ± 0.29 nmol N L(-1) d(-1) (1σ, n = 65). CO(2)-fixation rates, representing primary production, appeared to be nitrogen limited as suggested by low dissolved inorganic nitrogen to phosphate ratios (DIN:DIP) of about 2 ± 3.2 in surface waters. Nevertheless, N(2) fixation rates contributed only 0.55 ± 0.87% (range 0.03-5.24%) of the N required for primary production. Boosted regression trees analysis (BRT) showed that the distribution of the gamma A proteobacteria and filamentous cyanobacteria nifH genes was mainly predicted by the distribution of Prochlorococcus, Synechococcus, picoeukaryotes and heterotrophic bacteria. In addition, BRT indicated that multiple a-biotic environmental variables including nutrients DIN, dissolved organic nitrogen (DON) and DIP, trace metals like dissolved aluminum (DAl), as a proxy of dust inputs, dissolved iron (DFe) and Fe-binding ligands as well as oxygen and temperature influenced N(2) fixation rates and the distribution of the dominant diazotrophic phylotypes. Our results suggest that lower predicted oxygen concentrations and higher temperatures due to climate warming may increase N(2) fixation rates. However, the balance between a decreased supply of DIP and DFe from deep waters as a result of more pronounced stratification and an enhanced supply of these nutrients with a predicted increase in deposition of Saharan dust may ultimately determine the

  11. Pacific-North American teleconnection and North Pacific Oscillation: historical simulation and future projection in CMIP5 models

    Science.gov (United States)

    Chen, Zheng; Gan, Bolan; Wu, Lixin; Jia, Fan

    2017-09-01

    Based on reanalysis datasets and as many as 35 CMIP5 models, this study evaluates the capability of climate models to simulate the spatiotemporal features of Pacific-North American teleconnection (PNA) and North Pacific Oscillation (NPO) in the twentieth century wintertime, and further investigates their responses to greenhouse warming in the twenty-first century. Analysis reveals that while the majority (80%) of models reasonably simulate either the geographical distribution or the amplitude of PNA/NPO pattern, only half of models can well capture both features in space. As for the temporal features, variabilities of PNA and NPO in most models are biased toward higher amplitude. Additionally, most models simulate the interannual variabilities of PNA and NPO, qualitatively consistent with the observation, whereas models generally lack the capability to reproduce the decadal (20-25 years) variability of PNA. As the climate warms under the strongest future warming scenario, the PNA intensity is found to be strengthened, whereas there is no consensus on the direction of change in the NPO intensity among models. The intensification of positive PNA is primarily manifested in the large deepening of the North Pacific trough, which is robust as it is 2.3 times the unforced internal variability. By focusing on the tropical Pacific Ocean, we find that the multidecadal evolution of the North Pacific trough intensity (dominating the PNA intensity evolution) is closely related to that of the analogous trough in the PNA-like teleconnection forced by sea surface temperature anomalies (SSTa) in the tropical central Pacific (CP) rather than the tropical eastern Pacific (EP). Such association is also found to act under greenhouse warming: that is, the strengthening of the PNA-like teleconnection induced by the CP SSTa rather than the EP SSTa is a driving force for the intensification of PNA. This is in part owing to the robust enhancement of the tropical precipitation response to

  12. Pacific-North American teleconnection and North Pacific Oscillation: historical simulation and future projection in CMIP5 models

    Science.gov (United States)

    Chen, Zheng; Gan, Bolan; Wu, Lixin; Jia, Fan

    2018-06-01

    Based on reanalysis datasets and as many as 35 CMIP5 models, this study evaluates the capability of climate models to simulate the spatiotemporal features of Pacific-North American teleconnection (PNA) and North Pacific Oscillation (NPO) in the twentieth century wintertime, and further investigates their responses to greenhouse warming in the twenty-first century. Analysis reveals that while the majority (80%) of models reasonably simulate either the geographical distribution or the amplitude of PNA/NPO pattern, only half of models can well capture both features in space. As for the temporal features, variabilities of PNA and NPO in most models are biased toward higher amplitude. Additionally, most models simulate the interannual variabilities of PNA and NPO, qualitatively consistent with the observation, whereas models generally lack the capability to reproduce the decadal (20-25 years) variability of PNA. As the climate warms under the strongest future warming scenario, the PNA intensity is found to be strengthened, whereas there is no consensus on the direction of change in the NPO intensity among models. The intensification of positive PNA is primarily manifested in the large deepening of the North Pacific trough, which is robust as it is 2.3 times the unforced internal variability. By focusing on the tropical Pacific Ocean, we find that the multidecadal evolution of the North Pacific trough intensity (dominating the PNA intensity evolution) is closely related to that of the analogous trough in the PNA-like teleconnection forced by sea surface temperature anomalies (SSTa) in the tropical central Pacific (CP) rather than the tropical eastern Pacific (EP). Such association is also found to act under greenhouse warming: that is, the strengthening of the PNA-like teleconnection induced by the CP SSTa rather than the EP SSTa is a driving force for the intensification of PNA. This is in part owing to the robust enhancement of the tropical precipitation response to

  13. The integrated North American electricity market : investment in electricity infrastructure and supply : a North American concern

    International Nuclear Information System (INIS)

    Egan, T.

    2006-03-01

    Electricity supply and infrastructure solutions for the United States and Canada were discussed along with the availability of fuel supply and the diversity of fuel sources. This document focuses on investment in transmission infrastructure in order to assure sustainable generation sources for both countries while addressing constraints along the border, which will allow for enhanced cross-border trade. The Canadian Electricity Association has proposed 3 areas of bi-national cooperation to promote effective investment in electricity infrastructure and supply in the North American market: (1) cooperation in enhancing electricity supply, (2) cooperation in enhancing transmission infrastructure, and (3) cooperation in addressing air quality issues and climate change. The report discussed electricity generation by fuel source in Canada and the United States; status of restructuring in Canada; as well as the economic and environmental benefits of an integrated market. It also discussed regulatory and policy matters affecting the investment environment. Last, it discussed the need for opportunities for investment in the North American market, distribution and demand side measures, and cooperation in enhancing transmission infrastructure. It was concluded that growing electricity demand in both the United States and Canada requires investment in electricity infrastructure and supply in the future. Resolving electricity infrastructure and supply needs must be an international concern, requiring the full engagement and cooperation of both countries. 1 tab, 2 figs

  14. Decadal oxygen change in the eastern tropical North Atlantic

    Directory of Open Access Journals (Sweden)

    J. Hahn

    2017-07-01

    Full Text Available Repeat shipboard and multi-year moored observations obtained in the oxygen minimum zone (OMZ of the eastern tropical North Atlantic (ETNA were used to study the decadal change in oxygen for the period 2006–2015. Along 23° W between 6 and 14° N, oxygen decreased with a rate of −5.9 ± 3.5 µmol kg−1 decade−1 within the depth covering the deep oxycline (200–400 m, while below the OMZ core (400–1000 m oxygen increased by 4.0 ± 1.6 µmol kg−1 decade−1 on average. The inclusion of these decadal oxygen trends in the recently estimated oxygen budget for the ETNA OMZ suggests a weakened ventilation of the upper 400 m, whereas the ventilation strengthened homogeneously below 400 m. The changed ventilation resulted in a shoaling of the ETNA OMZ of −0.03 ± 0.02 kg m−3 decade−1 in density space, which was only partly compensated by a deepening of isopycnal surfaces, thus pointing to a shoaling of the OMZ in depth space as well (−22 ± 17 m decade−1. Based on the improved oxygen budget, possible causes for the changed ventilation are analyzed and discussed. Largely ruling out other ventilation processes, the zonal advective oxygen supply stands out as the most probable budget term responsible for the decadal oxygen changes.

  15. Reconstructed North American Snow Extent, 1900-1993

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains reconstructed monthly North American snow extent values for November through March, 1900-1993. Investigators used a combination of satellite...

  16. Vegetative Propagation and the Genetic Improvement of North American Hardwoods

    Science.gov (United States)

    R. E. Farmer

    1973-01-01

    Progress and problems in vegetative propagation of important North American hardwoods are reviewed with emphasis on rooting cuttings and the application of propagation techniques in breeding research. Some problems in rooting physiology are discussed.

  17. North American Society for Pediatric Gastroenterology, Hepatology and Nutrition

    Science.gov (United States)

    North American Society for Pediatric Gastroenterology, Hepatology and Nutrition Skip to Navigation NASPGHAN Annual Meeting and Postgraduate ... transition well. Moreover, Doc4me provides information about medications, nutrition and living with IBD. Please help us promote ...

  18. Climate Prediction Center (CPC) Daily Pacific North American Index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Pacific-North American pattern (PNA) is one of the leading teleconnection patterns in the Northern Hemisphere circulation. It is calculated as a Rotated...

  19. North American Mesoscale Forecast System (NAM) [12 km

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The North American Mesoscale Forecast System (NAM) is one of the major regional weather forecast models run by the National Centers for Environmental Prediction...

  20. North American Land Change Monitoring System (NALCMS) Collection

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The North American Land Change Monitoring System (NALCMS) is a trilateral effort between Canada, the United States, and Mexico, and is produced by the Canada Centre...

  1. EPA's Role with the North American Development Bank (NADB)

    Science.gov (United States)

    Following the 1993 signature of the North American Free Trade Agreement (NAFTA), two binational institutions were created to improve the environmental conditions of the U.S.-Mexico border region and enhance the well-being of residents.

  2. Rising synchrony controls western North American ecosystems

    Science.gov (United States)

    Bryan A. Black; Peter van der Sleen; Emanuele Di Lorenzo; Daniel Griffin; William J. Sydeman; Jason B. Dunham; Ryan R. Rykaczewski; Marisol García-Reyes; Mohammad Safeeq; Ivan Arismendi; Steven J. Bograd

    2018-01-01

    Along the western margin of North America, the winter expression of the North Pacific High (NPH) strongly influences interannual variability in coastal upwelling, storm track position, precipitation, and river discharge. Coherence among these factors induces covariance among physical and biological processes across adjacent marine and terrestrial ecosystems. Here, we...

  3. Transport and deposition of the fire biomarker levoglucosan across the tropical North Atlantic Ocean

    Science.gov (United States)

    Schreuder, Laura T.; Hopmans, Ellen C.; Stuut, Jan-Berend W.; Sinninghe Damsté, Jaap S.; Schouten, Stefan

    2018-04-01

    burning in northwestern Africa. However, close to South America levoglucosan concentrations appear to be affected by riverine transport from the Amazon River. In surface sediments close to South America, levoglucosan concentration is higher than in the middle of the Atlantic Ocean, implying that here the influence from the South American continent is important and perennial. Our study provides evidence that degradation of levoglucosan during settling in the marine water column is not substantial, but is substantial at the sediment-water interface. Nevertheless, levoglucosan was detected in all surface sediments throughout the tropical North Atlantic, indicating its presence in the marine sedimentary record, which reveals the potential for levoglucosan as a biomass burning proxy in marine sediments.

  4. 76 FR 53149 - North American Waterfowl Management Plan

    Science.gov (United States)

    2011-08-25

    ... fundamental objectives for waterfowl management from a list of 31 candidate objectives. During Round Two... American Waterfowl Management Plan AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of document... availability of the draft North American Waterfowl Management Plan Revision (draft Plan Revision) for public...

  5. Motivations of North American Indians in Athletic Games.

    Science.gov (United States)

    Pesavento, Wilma J.

    This is a report on the motives of North American Indians in holding their athletic games. Data were researched from "Annual Reports of the Bureau of American Ethnology" published between 1881 and 1933. Anthropologists, artifact collectors, artist-writers, and historians provided primary evidential sources for athletic game motivation.…

  6. Declines of seagrasses in a tropical harbour, North Queensland ...

    Indian Academy of Sciences (India)

    2015-04-17

    Apr 17, 2015 ... Centre for Tropical Water and Aquatic Ecosystem Research, James Cook University, Queensland, ... marily in the grey literature sponsored by the fishing indus- ..... age treatment plants were upgraded and urban and agri-.

  7. Forest disturbance and North American carbon flux

    Science.gov (United States)

    S. N. Goward; J. G. Masek; W. Cohen; G. Moisen; G. J. Collatz; S. Healey; R. A. Houghton; C. Huang; R. Kennedy; B. Law; S. Powell; D. Turner; M. A. Wulder

    2008-01-01

    North America's forests are thought to be a significant sink for atmospheric carbon. Currently, the rate of sequestration by forests on the continent has been estimated at 0.23 petagrams of carbon per year, though the uncertainty about this estimate is nearly 50%. This offsets about 13% of the fossil fuel emissions from the continent [Pacala et al., 2007]. However...

  8. The decline of North American freshwater fishes

    Science.gov (United States)

    Walsh, Stephen J.; Jelks, Howard L.; Burkhead, Noel M.

    2009-01-01

    North America has a broad array of freshwater ecosystems because of the continent's complex geography and geological history. Within a multitude of habitats—that include streams, large rivers, natural lakes, springs, and wetlands—rich assemblages of fishes reside, representing diverse taxonomic groups with unique ecological requirements. They face an unprecedented conservation crisis.1 In the last few decades, the proportion of inland fishes of North America, which are considered imperiled or extinct, increased from 20 to 40%.2 Although extinctions have occurred, many species and populations are declining in range size and abundance. The fish biota of the continent as a whole remains diverse; however, we can take action to stem any further declines.

  9. North American natural gas price outlook

    International Nuclear Information System (INIS)

    Denhardt, R.

    1998-01-01

    Issues regarding future natural gas prices for North America were discussed. Various aspects of the issue including the relationship between storage, weather and prices, received attention. It was noted that strong demand-growth will be needed to support near-term Canadian export increases without price declines. The issue of Gulf Coast production was also discussed. Power generation using natural gas as fuel is expected to support strong growth in the demand for natural gas. tabs., figs

  10. Water quality in North American river systems

    International Nuclear Information System (INIS)

    Becker, C.D.; Neitzel, D.A.

    1992-01-01

    This book is about water quality and other characteristics of selected ecosystems in North America. It is also about changes that have occurred in these ecosystems as a result of recent human activities-changes that result primarily from development and exploitation to sustain the needs of an ever-increasing population and the technical innovations that sustain it. Fish populations, hydrology, and water quality control efforts are discussed

  11. Air temperature change in the northern and southern tropical Andes linked to North-Atlantic stadials and Greenland interstadials

    Science.gov (United States)

    Urrego, Dunia H.; Hooghiemstra, Henry

    2016-04-01

    We use eight pollen records reflecting climatic and environmental change from northern and southern sites in the tropical Andes. Our analysis focuses on the signature of millennial-scale climate variability during the last 30,000 years, in particular the Younger Dryas (YD), Heinrich stadials (HS) and Greenland interstadials (GI). We identify rapid responses of the vegetation to millennial-scale climate variability in the tropical Andes. The signature of HS and the YD are generally recorded as downslope migrations of the upper forest line (UFL), and are likely linked to air temperature cooling. The GI1 signal is overall comparable between northern and southern records and indicates upslope UFL migrations and warming in the tropical Andes. Our marker for lake level changes indicates a north to south difference that could be related to moisture availability. The direction of air temperature change recorded by the Andean vegetation is consistent with millennial-scale cryosphere and sea surface temperature records from the American tropics, but suggests a potential difference between the magnitude of temperature change in the ocean and the atmosphere.

  12. Rising synchrony controls western North American ecosystems

    Science.gov (United States)

    Black, Bryan A.; van der Sleen, Peter; Di Lorenzo, Emanuele; Griffin, Daniel; Sydeman, William J.; Dunham, Jason B.; Rykaczewski, Ryan R.; Garcia-Reyes, Marisol; Safeeq, Mohammad; Arismendi, Ivan; Bograd, Steven J.

    2018-01-01

    Along the western margin of North America, the winter expression of the North Pacific High (NPH) strongly influences interannual variability in coastal upwelling, storm track position, precipitation, and river discharge. Coherence among these factors induces covariance among physical and biological processes across adjacent marine and terrestrial ecosystems. Here, we show that over the past century the degree and spatial extent of this covariance (synchrony) has substantially increased, and is coincident with rising variance in the winter NPH. Furthermore, centuries‐long blue oak (Quercus douglasii) growth chronologies sensitive to the winter NPH provide robust evidence that modern levels of synchrony are among the highest observed in the context of the last 250 years. These trends may ultimately be linked to changing impacts of the El Niño Southern Oscillation on mid‐latitude ecosystems of North America. Such a rise in synchrony may destabilize ecosystems, expose populations to higher risks of extinction, and is thus a concern given the broad biological relevance of winter climate to biological systems.

  13. Extinction rates in North American freshwater fishes, 1900-2010

    Science.gov (United States)

    Burkhead, Noel M.

    2012-01-01

    Widespread evidence shows that the modern rates of extinction in many plants and animals exceed background rates in the fossil record. In the present article, I investigate this issue with regard to North American freshwater fishes. From 1898 to 2006, 57 taxa became extinct, and three distinct populations were extirpated from the continent. Since 1989, the numbers of extinct North American fishes have increased by 25%. From the end of the nineteenth century to the present, modern extinctions varied by decade but significantly increased after 1950 (post-1950s mean = 7.5 extinct taxa per decade). In the twentieth century, freshwater fishes had the highest extinction rate worldwide among vertebrates. The modern extinction rate for North American freshwater fishes is conservatively estimated to be 877 times greater than the background extinction rate for freshwater fishes (one extinction every 3 million years). Reasonable estimates project that future increases in extinctions will range from 53 to 86 species by 2050.

  14. Testing for common features in North American energy markets

    Energy Technology Data Exchange (ETDEWEB)

    Serletis, Apostolos; Rangel-Ruiz, Ricardo [Calgary Univ., Dept. of Economics, Calgary, AB (Canada)

    2004-05-01

    Using recent advances in the field of applied econometrics, we explore the strength of shared trends and shared cycles between North American natural gas and crude oil markets. In doing so, we use daily data from January 1991 to April 2001 on spot U.S. Henry Hub natural gas and WTI crude oil prices. The results show that there has been 'decoupling' of the prices of these two sources of energy as a result of oil and gas deregulation in the United States. We also investigate the interconnectedness of North American natural gas markets and find that North American natural gas prices are largely defined by the U.S. Henry Hub price trends (Author)

  15. Seeds of Doubt: North American farmers' experiences of GM crops

    OpenAIRE

    Warwick, Hugh; Meziani, Gundula

    2002-01-01

    The picture the biotechnology industry has painted of GM crops in North America is one of unqualified success, after six years of commercial growing. The objective of this report was to assess whether this image is accurate and if not what problems have occurred. We present interviews with North American farmers about their experiences of GM soya, maize and oilseed rape, and review of some of the independent research. The evidence we have gathered demonstrates that GM food crops are far f...

  16. North American snake and scorpion envenomations.

    Science.gov (United States)

    Wilbeck, Jennifer; Gresham, Chip

    2013-06-01

    Envenomations by snakes and scorpions in North America, although uncommon, do occur, and the victims may seek medical treatment. Combined, snake and scorpion encounters result in more than 25,000 calls a year to poison centers. Although some similarities exist with respect to general signs of envenomation and treatment, specific nuances distinguish the medical care to be anticipated and therapies available. Regardless of geographic practice area, exposures will occur that may result in a significant envenomation. This article provides critical care nurses with fundamental knowledge of varied snake and scorpion envenomation presentations and treatments to assist in optimizing patient outcomes. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. North American energy market : convergence and integration

    International Nuclear Information System (INIS)

    Schlesinger, B.

    1998-01-01

    The paper provides an exposition of supply and demand issues within the natural gas industry in North America. Various aspects of the issue are discussed, including the growth in gas demand and the impact that a price hold of one per cent per year will have on demand. It was predicted that the gas share of U.S. power generation will triple by 2015 and that major pipeline expansions will deliver the new gas to markets. A doubling of eastbound gas deliveries was also predicted. tabs., figs

  18. Acceptance of irradiated food by North American consumers

    International Nuclear Information System (INIS)

    Marcotte, M.; Kunstadt, P.

    1993-01-01

    Sales of irradiated foods clearly indicate that North American consumers appreciate the value of irradiated foods. The results of North American consumer attitude surveys can be used to predict acceptance of quality irradiated foods, especially when improved food safety is the perceived benefit. Consumers perceive the most benefit when irradiation is used to improve food safety or to reduce the chemicals used on foods. Information about irradiation seems to increase consumer willingness to buy. Consumer activists continue to attempt to prevent the sale of labelled irradiated foods, but they have not been successful. (author)

  19. Futures trading and the storage of North American natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Serletis, Apostolos; Shahmoradi, Asghar [Calgary Univ., Dept. of Economics, Calgary, AB (Canada)

    2006-03-15

    This paper tests the theory of storage in North American natural gas markets, using the Fama and French (1988) indirect test. In particular, we test the theory's prediction that when inventory is high, large inventory responses to shocks imply roughly equal changes in spot and futures prices, whereas when inventory is low, smaller inventory responses to shocks imply larger changes in spot prices than in futures prices. Our tests on spot and futures North American natural gas prices confirm these predictions of the theory of storage. (Author)

  20. 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.

  1. African American and Hispanic American sportsmen in the north central region

    Science.gov (United States)

    Allan Marsinko; John Dwyer

    2003-01-01

    Public forest managers need an awareness and understanding of their clients in order to better address their needs for recreational uses of forest lands. This study examines and characterizes African American and Hispanic American sportsmen (hunters and anglers) in the North Central Region of the United Stares (IA, IL, IN, MI, MN, MO, WI) and compares them to African...

  2. The impact of summertime north Indian Ocean SST on tropical cyclone genesis over the western North Pacific

    Science.gov (United States)

    Zheng, Jiayu; Wu, Qiaoyan; Guo, Yipeng; Zhao, Sen

    2017-04-01

    In this study, we investigate the impact of interannual variability of boreal summertime (June-September) north Indian Ocean (NIO) sea surface temperature (SST) on the distribution of tropical cyclone (TC) genesis over the western North Pacific (WNP) using observational datasets. In the boreal summers with warm (cold) SST in the NIO, fewer (more) than normal TCs form over the entire WNP, with fewer (more) TCs forming north of 10°N and more (fewer) TCs forming south of 10°N. The warm (cold) SST in the NIO induces anomalous anticyclonic (cyclonic) vorticity north of 10°N and cyclonic (anticyclonic) vorticity south of 10°N, which contributes to the meridional seesaw-like distribution of WNP TC genesis. This study provides a new perspective to understand TC activities over the WNP and may help seasonal TC prediction.

  3. 47 CFR 52.11 - North American Numbering Council.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false North American Numbering Council. 52.11 Section... recommendations, reached through consensus, that foster efficient and impartial number administration; (c) Initially resolving disputes, through consensus, that foster efficient and impartial number administration...

  4. Sex Education Attitudes and Outcomes among North American Women

    Science.gov (United States)

    Williams, Monnica T.; Bonner, Laura

    2006-01-01

    Attitudes and outcomes of sex education received by North American women are examined via an Internet survey (N = 1,400). Mean age was 19.5, with 24% reporting one or more unplanned pregnancies. Women were more satisfied with sex education from informal sources than from parents, schools, and physicians. Those receiving sex education from parents…

  5. Conservation status of imperiled North American freshwater and diadromous fishes

    Science.gov (United States)

    Howard L. Jelks; Stephen J. Walsh; Noel M. Burkhead; Salvador Contreras-Balderas; Edmundo Diaz-Pardo; Dean A. Hendrickson; John Lyons; Nicholas E. Mandrak; Frank McCormick; Joseph S. Nelson; Steven P. Plantania; Brady A. Porter; Claude B. Renaud; Juan Jacobo Schmitter-Soto; Eric B. Taylor; Melvin L. Jr. Warren

    2008-01-01

    This is the third compilation of imperiled (i.e., endangered, threatened, vulnerable) plus extinct freshwater and diadromous fishes of North America prepared by the American Fisheries Society?s Endangered Species Committee. Since the last revision in 1989, imperilment of inland fishes has increased substantially. This list includes 700 extant taxa representing 133...

  6. Exploring research priorities for the North American hardwood industry

    Science.gov (United States)

    David Brinberg; Earl Kline; Delton Alderman; Philip Araman; Ed Cesa; Steve Milauskas; Tom Walthousen; Jan Wiedenbeck

    2008-01-01

    With the increase of globalization, the North American hardwood industry is facing many challenges to remain competitive and sustainable, facing drastic changes in the areas of labor, land, manufacturing, markets and marketing, and supply chain. The hardwood industry is especially vulnerable, with the influx of foreign manufacturers and suppliers with greater natural...

  7. Environmental management in North American mining sector.

    Science.gov (United States)

    Asif, Zunaira; Chen, Zhi

    2016-01-01

    This paper reviews the environmental issues and management practices in the mining sector in the North America. The sustainable measures on waste management are recognized as one of the most serious environmental concerns in the mining industry. For mining activities, it will be no surprise that the metal recovery reagents and acid effluents are a threat to the ecosystem as well as hazards to human health. In addition, poor air quality and ventilation in underground mines can lead to occupational illness and death of workers. Electricity usage and fuel consumption are major factors that contribute to greenhouse gases. On the other hand, many sustainability challenges are faced in the management of tailings and disposal of waste rock. This paper aims to highlight the problems that arise due to poor air quality and acid mine drainage. The paper also addresses some of the advantages and limitations of tailing and waste rock management that still have to be studied in context of the mining sector. This paper suggests that implementation of suitable environmental management tools like life cycle assessment (LCA), cleaner production technologies (CPTs), and multicriteria decision analysis (MCD) are important as it ultimately lead to improve environmental performance and enabling a mine to focus on the next stage of sustainability.

  8. Diabetes awareness among African Americans in rural North Carolina.

    Science.gov (United States)

    Antony, Angela K; Baaklini, Walid A

    2004-01-01

    To evaluate the extent of diabetes unawareness in rural North Carolina. Randomly administered an eight-question survey to African Americans age 15-74 living in Halifax County North Carolina. Ninety-five out of 116 eligible participants completed the survey (82% response rate). Most (67%) of the participants reported having two or more major risk factors for Type II diabetes (diabetes mellitus). More than half (51.6%) of the participants were obese. Most (96.8%) of the participants reported having been tested for diabetes at some point in their lives (10% testedpositive, only 8.4% of the remaining 9o% reported ever having a second test). Diabetes mellitus is a very prevalentproblem among the African American population of Halifax County North Carolina. Our study underscores the fact that patients are not systematically screened and followed-up for diabetes melitus. More healthcare and commnity programs need to be adapted to fight this serious public health problem.

  9. The response of the North Pacific Decadal Variability to strong tropical volcanic eruptions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tao [Chinese Academy of Sciences, Nansen-Zhu International Research Center, Institute of Atmospheric Physics, Beijing (China); Otteraa, Odd Helge [Uni Bjerknes Centre, Uni Research, Bergen (Norway); Bjerknes Center for Climate Research, Bergen (Norway); Gao, Yongqi [Chinese Academy of Sciences, Nansen-Zhu International Research Center, Institute of Atmospheric Physics, Beijing (China); Bjerknes Center for Climate Research, Bergen (Norway); Nansen Environmental and Remote Sensing Center, Bergen (Norway); Wang, Huijun [Chinese Academy of Sciences, Nansen-Zhu International Research Center, Institute of Atmospheric Physics, Beijing (China); Chinese Academy of Sciences, Climate Change Research Center, Institute of Atmospheric Physics, Beijing (China)

    2012-12-15

    In this study, the effects of volcanic forcing on North Pacific climate variability, on interannual to decadal time scales, are examined using climate model simulations covering the last 600 years. The model used is the Bergen Climate Model, a fully coupled atmosphere-ocean general circulation model. It is found that natural external forcings, such as tropical strong volcanic eruptions (SVEs) and variations in total solar irradiance, play an important role in regulating North Pacific Decadal Variability (NPDV). In response to tropical SVEs the lower stratospheric pole-to-equator temperature gradient is enhanced. The North polar vortex is strengthened, which forces a significant positive Arctic Oscillation. At the same time, dipole zonal wind anomalies associated with strong polar vortex propagate downward from the lower stratosphere. Through positive feedbacks in the troposphere, the surface westerly winds across the central North Pacific are significantly weakened, and positive sea level pressure anomalies are formed in the North Pacific. This anomalous surface circulation results in changes in the net heat fluxes and the oceanic advection across the North Pacific. As a result of this, warm water converges in the subtropical western North Pacific, where the surface waters in addition are heated by significantly reduced latent and sensible heat fluxes from the ocean. In the eastern and high-latitude North Pacific the ocean loses more heat, and large-scale decreases in sea surface temperatures are found. The overall response of this chain of events is that the North Pacific enters a negative phase of the Pacific decadal oscillation (PDO), and this negative phase of the PDO is maintained for several years. It is thus concluded that the volcanic forcing plays a key role in the phasing of the PDO. The model results furthermore highlight the important role of troposphere-stratosphere coupling, tropical-extratropical teleconnections and extratropical ocean

  10. An Extended Forecast of the Frequencies of North Atlantic Basin Tropical Cyclone Activity for 2009

    Science.gov (United States)

    Wilson, Robert M.

    2009-01-01

    An extended forecast of the frequencies for the 2009 North Atlantic basin hurricane season is presented. Continued increased activity during the 2009 season with numbers of tropical cyclones, hurricanes, and major hurricanes exceeding long-term averages are indicated. Poisson statistics for the combined high-activity intervals (1950-1965 and 1995-2008) give the central 50% intervals to be 9-14, 5-8, and 2-4, respectively, for the number of tropical cyclones, hurricanes, and major hurricanes, with a 23.4% chance of exceeding 14 tropical cyclones, a 28% chance of exceeding 8 hurricanes, and a 31.9% chance of exceeding 4 major hurricanes. Based strictly on the statistics of the current high-activity interval (1995-2008), the central 50% intervals for the numbers of tropical cyclones, hurricanes, and major hurricanes are 12-18, 6-10, and 3-5, respectively, with only a 5% chance of exceeding 23, 13, or 7 storms, respectively. Also examined are the first differences in 10-yr moving averages and the effects of global warming and decadal-length oscillations on the frequencies of occurrence for North Atlantic basin tropical cyclones. In particular, temperature now appears to be the principal driver of increased activity and storm strength during the current high-activity interval, with near-record values possible during the 2009 season.

  11. LNG : its potential impact on North American markets

    International Nuclear Information System (INIS)

    Schlesinger, B.

    2003-01-01

    Liquefied natural gas (LNG) is expected to play a greater role in North American gas supplies and markets due to the decrease in conventional natural gas production in North America accompanied by an increase in demand for energy. It is expected that the overall share of the LNG gas market will rise from about 1.4 per cent in 2002 to more than 5 per cent by 2020, and potentially up to 15 per cent by that year. The construction of at least 15 new LNG receiving terminals has been proposed for location in the U.S., Canada, and Mexico. In addition, El Paso has proposed a novel offshore LNG receiving concept involving offshore gas pipelines and on-board-ship regasification. As trading of LNG increases in the Atlantic, markets in eastern United States and Canada will benefit from improved gas supplies, but pricing patterns are expected to change. Basis differentials along the Atlantic coastline will probably diminish, potentially reducing the value of Sable Island gas and the pipeline system that runs north to south along the eastern coast of North America. It was noted that Middle Eastern suppliers of LNG will play an important potential role in North American markets. 19 figs

  12. Reactive Halogens in the Marine Boundary Layer (RHaMBLe: the tropical North Atlantic experiments

    Directory of Open Access Journals (Sweden)

    J. D. Lee

    2010-02-01

    Full Text Available The NERC UK SOLAS-funded Reactive Halogens in the Marine Boundary Layer (RHaMBLe programme comprised three field experiments. This manuscript presents an overview of the measurements made within the two simultaneous remote experiments conducted in the tropical North Atlantic in May and June 2007. Measurements were made from two mobile and one ground-based platforms. The heavily instrumented cruise D319 on the RRS Discovery from Lisbon, Portugal to São Vicente, Cape Verde and back to Falmouth, UK was used to characterise the spatial distribution of boundary layer components likely to play a role in reactive halogen chemistry. Measurements onboard the ARSF Dornier aircraft were used to allow the observations to be interpreted in the context of their vertical distribution and to confirm the interpretation of atmospheric structure in the vicinity of the Cape Verde islands. Long-term ground-based measurements at the Cape Verde Atmospheric Observatory (CVAO on São Vicente were supplemented by long-term measurements of reactive halogen species and characterisation of additional trace gas and aerosol species during the intensive experimental period.

    This paper presents a summary of the measurements made within the RHaMBLe remote experiments and discusses them in their meteorological and chemical context as determined from these three platforms and from additional meteorological analyses. Air always arrived at the CVAO from the North East with a range of air mass origins (European, Atlantic and North American continental. Trace gases were present at stable and fairly low concentrations with the exception of a slight increase in some anthropogenic components in air of North American origin, though NOx mixing ratios during this period remained below 20 pptv (note the non-IUPAC adoption in this manuscript of pptv and ppbv, equivalent to pmol mol−1 and nmol mol−1 to reflect common practice. Consistency with

  13. Ecology and conservation of North American sea ducks

    Science.gov (United States)

    Savard, Jean-Pierre L.; Derksen, Dirk V.; Esler, Daniel N.; Eadie, John M.

    2015-01-01

    The past decade has seen a huge increase in the interest and attention directed toward sea ducks, the Mergini tribe. This has been inspired, in large part, by the conservation concerns associated with numerical declines in several sea duck species and populations, as well as a growing appreciation for their interesting ecological attributes. Reflecting the considerable research recently conducted on this tribe, Ecology and Conservation of North American Sea Ducks examines the 15 extant species of sea ducks from North America.

  14. 76 FR 48145 - North American Free-Trade Agreement, Article 1904; Binational Panel Reviews: Notice of...

    Science.gov (United States)

    2011-08-08

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free-Trade Agreement.... SUPPLEMENTARY INFORMATION: Chapter 19 of the North American Free-Trade Agreement (``Agreement'') established a..., United States Section, International Trade Administration, Department of Commerce. ACTION: Notice of...

  15. 78 FR 45181 - North American Free Trade Agreement (NAFTA), Article 1904 Binational Panel Reviews: Notice of...

    Science.gov (United States)

    2013-07-26

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free Trade Agreement..., (202) 482-5438. SUPPLEMENTARY INFORMATION: Chapter 19 of the North American Free Trade Agreement... Secretariat, United States Section, International Trade Administration, Department of Commerce. ACTION: On...

  16. Halogenated organic species over the tropical South American rainforest

    Directory of Open Access Journals (Sweden)

    S. Gebhardt

    2008-06-01

    Full Text Available Airborne measurements of the halogenated trace gases methyl chloride, methyl bromide and chloroform were conducted over the Atlantic Ocean and about 1000 km of pristine tropical rainforest in Suriname and French Guyana (3–6° N, 51–59° W in October 2005. In the boundary layer (0–1.4 km, maritime air masses, advected over the forest by southeasterly trade winds, were measured at various distances from the coast. Since the organohalogens presented here have relatively long atmospheric lifetimes (0.4–1.0 years in comparison to the advection times from the coast (1–2 days, emissions will accumulate in air traversing the rainforest. The distributions of methyl chloride, methyl bromide and chloroform were analyzed as a function of time the air spent over land and the respective relationship used to determine net fluxes from the rainforest for one week within the long dry season.

    Net fluxes from the rainforest ecosystem have been calculated for methyl chloride and chloroform as 9.5 (±3.8 2σ and 0.35 (±0.15 2σμg m-2 h−1, respectively. No significant flux was observed for methyl bromide within the limits of these measurements.

    The global budget of methyl chloride contains large uncertainties, in particular with regard to a possible source from tropical vegetation. Our measurements are used in a large-scale approach to determine the net flux from a tropical ecosystem to the planetary boundary layer. The obtained global net flux of 1.5 (±0.6 2σ Tg yr-1 for methyl chloride is at the lower end of current estimates for tropical vegetation sources, which helps to constrain the range of tropical sources and sinks (0.82 to 8.2 Tg yr-1 from tropical plants, 0.03 to 2.5 Tg yr-1 from senescent/dead leaves and a sink of 0.1 to 1.6 Tg yr-1 by soil uptake. Nevertheless, these results show that the contribution of the rainforest ecosystem is the major source in the

  17. (North American Studies in Spain: between eclecticism and politics

    Directory of Open Access Journals (Sweden)

    Francisco Collado Rodríguez

    2006-01-01

    Full Text Available At present, the Spanish university system does not offer any specific place for American Studies. In practical terms, this means that there is not such a thing as a degree in (North American Studies for undergraduate students. The study of the history and culture of the United States of America is mostly disseminated all over the country in a number of departments of English, English—and English literature—still being the main subject of study in the only BA degree somehow related to our fie...

  18. Thermal adaptation in North American cicadas (Hemiptera: Cicadidae).

    Science.gov (United States)

    Sanborn, Allen F; Heath, James E; Heath, Maxine S; Phillips, Polly K

    2017-10-01

    We determine and summarize the thermal responses for 118 species and subspecies of North American cicadas representing more than 50 years of fieldwork and experimentation. We investigate the role that habitat and behavior have on the thermal adaptation of the North American cicadas. There are general patterns of increasing thermal responses in warmer floristic provinces and increasing maximum potential temperature within a habitat. Altitude shows an inverse relationship with thermal responses. Comparison of thermal responses of species emerging early or late in the season within the same habitat show increases in the thermal responses along with the increasing environmental temperatures late in the summer. However, behavior, specifically the use of endothermy as a thermoregulatory strategy, can influence the values determined in a particular habitat. Subspecies generally do not differ in their thermal tolerances and thermal tolerances are consistent within a species over distances of more than 7600km. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. P450 Pharmacogenetics in Indigenous North American Populations

    Directory of Open Access Journals (Sweden)

    Lindsay M. Henderson

    2018-02-01

    Full Text Available Indigenous North American populations, including American Indian and Alaska Native peoples in the United States, the First Nations, Métis and Inuit peoples in Canada and Amerindians in Mexico, are historically under-represented in biomedical research, including genomic research on drug disposition and response. Without adequate representation in pharmacogenetic studies establishing genotype-phenotype relationships, Indigenous populations may not benefit fully from new innovations in precision medicine testing to tailor and improve the safety and efficacy of drug treatment, resulting in health care disparities. The purpose of this review is to summarize and evaluate what is currently known about cytochrome P450 genetic variation in Indigenous populations in North America and to highlight the importance of including these groups in future pharmacogenetic studies for implementation of personalized drug therapy.

  20. North American demand and supply dynamics - implications for pricing

    International Nuclear Information System (INIS)

    George, R.

    1998-01-01

    Key issues regarding the natural gas industry and the long-term outlook for North American supply and demand for natural gas were discussed. The North American market was characterized as not a mature market, meaning that demand will continue to increase in the coming years. It was confidently predicted that supplies will be available for development at reasonable costs. However, real prices will slowly increase over time. Short-term fundamentals, expectations and pricing outlook were also discussed. The influence of upstream activity levels, the health of the economy, weather and storage were all identified as factors that will impact on short-term price expectations. According to this author a minor increase in price may be expected during the winter of 1998/1999. tabs., figs

  1. A satellite observational and numerical study of precipitation characteristics in western North Atlantic tropical cyclones

    Science.gov (United States)

    Rodgers, Edward B.; Chang, Simon W.; Pierce, Harold F.

    1994-01-01

    Special Sensor Microwave/Imager (SSM/I) observations were used to examine the spatial and temporal changes of the precipitation characteristics of tropical cyclones. SSM/I observations were also combined with the results of a tropical cyclone numerical model to examine the role of inner-core diabatic heating in subsequent intensity changes of tropical cyclones. Included in the SSM/I observations were rainfall characteristics of 18 named western North Atlantic tropical cyclones between 1987 and 1989. The SSM/I rain-rate algorithm that employed the 85-GHz channel provided an analysis of the rain-rate distribution in greater detail. However, the SSM/I algorithm underestimated the rain rates when compared to in situ techniques but appeared to be comparable to the rain rates obtained from other satellite-borne passive microwave radiometers. The analysis of SSM/I observations found that more intense systems had higher rain rates, more latent heat release, and a greater contribution from heavier rain to the total tropical cyclone rainfall. In addition, regions with the heaviest rain rates were found near the center of the most intense tropical cyclones. Observational analysis from SSM/I also revealed that the greatest rain rates in the inner-core regions were found in the right half of fast-moving cyclones, while the heaviest rain rates in slow-moving tropical cyclones were found in the forward half. The combination of SSM/I observations and an interpretation of numerical model simulations revealed that the correlation between changes in the inner core diabetic heating and the subsequent intensity became greater as the tropical cyclones became more intense.

  2. Random fractal structures in North American energy markets

    Energy Technology Data Exchange (ETDEWEB)

    Serletis, Apostolos [Calgary Univ., Dept. of Economics, Calgary, AB (Canada); Andreadis, Ioannis [European Univ. of the Hague, Center of Management Studies, The Hague (Netherlands)

    2004-05-01

    This paper uses daily observations on West Texas Intermediate (WTI) crude oil prices at Chicago and Henry Hub natural gas prices at LA (over the deregulated period of the 1990s) and various tests from statistics and dynamical systems theory to support a random fractal structure for North American energy markets. In particular, this evidence is supported by the Vassilicos et al. (1993) multifractal structure test and the Ghashghaie et al. [Nature 381 (1996) 767] turbulent behavior test. (Author)

  3. Lithospheric structure and deformation of the North American continent

    OpenAIRE

    Magdala Tesauro; Mikhail Kaban; S. Cloetingh; W. D. Mooney

    2013-01-01

    We estimate the integrated strength and elastic thickness (Te) of the North American lithosphere based on thermal, density and structural (seismic) models of the crust and upper mantle. The temperature distribution in the lithosphere is estimated considering for the first time the effect of composition as a result of the integrative approach based on a joint analysis of seismic and gravity data. We do this via an iterative adjustment of the model. The upper mantle temperatures are initially e...

  4. Team Update on North American Proton Facilities for Radiation Testing

    Science.gov (United States)

    Label, Kenneth A.; Turflinger, Thomas; Haas, Thurman; George, Jeffrey; Moss, Steven; Davis, Scott; Kostic, Andrew; Wie, Brian; Reed, Robert; Guertin, Steven; hide

    2016-01-01

    In the wake of the closure of the Indiana University Cyclotron Facility (IUCF), this presentation provides an overview of the options for North American proton facilities. This includes those in use by the aerospace community as well as new additions from the cancer therapy regime. In addition, proton single event testing background is provided for understanding the criteria needed for these facilities for electronics testing.

  5. 76 FR 38203 - Proposed Information Collection; North American Woodcock Singing Ground Survey

    Science.gov (United States)

    2011-06-29

    ...] Proposed Information Collection; North American Woodcock Singing Ground Survey AGENCY: Fish and Wildlife... populations. The North American Woodcock Singing Ground Survey is an essential part of the migratory bird.... II. Data OMB Control Number: 1018-0019. Title: North American Woodcock Singing Ground Survey. Service...

  6. 76 FR 16743 - Applications for New Awards; Program for North American Mobility in Higher Education

    Science.gov (United States)

    2011-03-25

    ... DEPARTMENT OF EDUCATION Applications for New Awards; Program for North American Mobility in Higher... Postsecondary Education (FIPSE)--Special Focus Competition: Program for North American Mobility in Higher... Program for North American Mobility in Higher Education, CFDA number 84.116N, must be submitted...

  7. 75 FR 78726 - Agency Information Collection Activities: North American Free Trade Agreement Duty Deferral

    Science.gov (United States)

    2010-12-16

    ... Activities: North American Free Trade Agreement Duty Deferral AGENCY: U.S. Customs and Border Protection (CBP... collection requirement concerning the North American Free Trade Agreement (NAFTA) Duty Deferral. This request...: 1651-0071. Abstract: The provisions of North American Free Trade Agreement (NAFTA) were adopted by the...

  8. The Scientific Development of the Physiology of Plants in the American Tropics

    Directory of Open Access Journals (Sweden)

    Marco V. Gutiérrez

    2002-06-01

    Full Text Available This paper is a research and journalistic work that summarizes and synthesizes the scientific development of the physiology of plants in the American tropics, also known as the Neotropics. It contains the contributions of numerous biologists interested in the physiology of tropical plants. The fabulous structural and functional diversity of tropical forests is still the major driver of research in this field. Classical physiological work involving tropical plants, such as the discovery of C4 photosynthesis in sugarcane, is invoked to exemplify the historical and current importance of physiological research in the tropics, and its applications in agriculture, forestry and conservation. An historical background describing the early and more recent development of a tradition on the physiological study of tropical plants is followed by a summary of the research conducted on the physiology of tropical crops. Common areas of interest and influence between the fields of crop physiology and plant ecophysiology are identified and exemplified with problems on the environmental physiology of crops like coffee and cassava. The physiology of tropical forest plants is discussed in terms of its contributions to general plant physiological knowledge in areas such as photosynthetic metabolism and plant water relations. Despite the impressive technical advances achieved during the past decade, the importance of continuous development of appropriate instrumentation to study and measure the physiology of plants in situ is stressed. Although the basic metabolic processes that underlie the mechanisms of plant responses to the environment are probably highly conserved and qualitatively similar among tropical and temperate plants, it is also apparent that tropical plants exhibit metabolic peculiarities. These include aspects of photosynthetic metabolism, phloem transport physiology, sensitivity to low temperatures, reproduction, responses to climatic seasonality, and a

  9. An engine for global plant diversity: Highest evolutionary turnover and emigration in the American tropics

    Directory of Open Access Journals (Sweden)

    Alexandre eAntonelli

    2015-04-01

    Full Text Available Understanding the processes that have generated the latitudinal biodiversity gradient and the continental differences in tropical biodiversity remains a major goal of evolutionary biology. Here we estimate the timing and direction of range shifts of extant flowering plants (angiosperms between tropical and non-tropical zones, and into and out of the major tropical regions of the world. We then calculate rates of speciation and extinction taking into account incomplete taxonomic sampling. We use a recently published fossil calibrated phylogeny and apply novel bioinformatic tools to code species into user-defined polygons. We reconstruct biogeographic history using stochastic character mapping to compute relative numbers of range shifts in proportion to the number of available lineages through time. Our results, based on the analysis of c. 22,600 species and c. 20 million geo-referenced occurrence records, show no significant differences between the speciation and extinction of tropical and non-tropical angiosperms. This suggests that at least in plants, the tropical biodiversity gradient primarily derives from other factors than differential rates of diversification. In contrast, the outstanding species richness found today in the American tropics (the Neotropics, as compared to tropical Africa and tropical Asia, is associated with significantly higher speciation and extinction rates. This suggests an exceedingly rapid evolutionary turnover, i.e. Neotropical species being formed and replaced by one another at unparalleled rates. In addition, tropical America stands out from other continents by having ‘pumped out’ more species than it received through most of the last 66 million years. These results imply that the Neotropics have acted as an engine for global plant diversity.

  10. Attribution of the Regional Patterns of North American Climate Trends

    Science.gov (United States)

    Hoerling, M.; Kumar, A.; Karoly, D.; Rind, D.; Hegerl, G.; Eischeid, J.

    2007-12-01

    North American trends in surface temperature and precipitation during 1951-2006 exhibit large spatial and seasonal variations. We seek to explain these by synthesizing new information based on existing model simulations of climate and its forcing, and based on modern reanalyses that describe past and current conditions within the free atmosphere. The presentation focuses on current capabilities to explain the spatial variations and seasonal differences in North American climate trends. It will address whether various heterogeneities in space and time can be accounted for by the climate system's sensitivity to time evolving anthropogenic forcing, and examines the influences of non-anthropogenic processes. New findings are presented that indicate anthropogenic forcing alone was unlikely the cause for key regional and seasonal patterns of change, including the absence of summertime warming over the Great Plains of the United States, and the absence of warming during both winter and summer over the southern United States. Key regional features are instead attributed to trends in the principal patterns of atmospheric flow that affect North American climate. It is demonstrated that observed variations in global sea surface temperatures have significantly influenced these patterns of atmospheric flow.

  11. Aldehyde dehydrogenase polymorphism in North American, South American, and Mexican Indian populations.

    Science.gov (United States)

    Goedde, H W; Agarwal, D P; Harada, S; Rothhammer, F; Whittaker, J O; Lisker, R

    1986-01-01

    While about 40% of the South American Indian populations (Atacameños, Mapuche, Shuara) were found to be deficient in aldehyde dehydrogenase isozyme I (ALDH2 or E2), preliminary investigations showed very low incidence of isozyme deficiency among North American natives (Sioux, Navajo) and Mexican Indians (mestizo). Possible implications of such trait differences on cross-cultural behavioral response to alcohol drinking are discussed. PMID:3953578

  12. Temperature responses of tropical to warm temperate Cladophora species in relation to their distribution in the North Atlantic Ocean

    Science.gov (United States)

    Cambridge, M. L.; Breeman, A. M.; Kraak, S.; van den Hoek, C.

    1987-09-01

    The relationship between distribution boundaries and temperature responses of some North Atlantic Cladophora species (Chlorophyta) was experimentally examined under various regimes of temperature, light and daylength. Experimentally determined critical temperature intervals, in which survival, growth or reproduction was limited, were compared with annual temperature regimes (monthly means and extremes) at sites inside and outside distribution boundaries. The species tested belonged to two phytogeographic groups: (1) the tropical West Atlantic group ( C. submarina: isolate from Curaçao) and (2) the amphiatlantic tropical to warm temperate group ( C. prolifera: isolate from Corsica; C. coelothrix: isolates from Brittany and Curaçao; and C. laetevirens: isolates from deep and shallow water in Corsica and from Brittany). In accordance with distribution from tropical to warm temperate regions, each of the species grew well between 20 30°C and reproduction and growth were limited at and below 15°C. The upper survival limit in long days was <35°C in all species but high or maximum growth rates occurred at 30°C. C. prolifera, restricted to the tropical margins, had the most limited survival at 35°C. Experimental evidence suggests that C. submarina is restricted to the Caribbean and excluded from the more northerly American mainland and Gulf of Mexico coasts by sporadic low winter temperatures in the nearshore waters, when cold northerly weather penetrates far south every few years. Experimental evidence suggests that C. prolifera, C. coelothrix and C. laetevirens are restricted to their northern European boundaries by summer temperatures too low for sufficient growth and/or reproduction. Their progressively more northerly located boundaries were accounted for by differences in growth rates over the critical 10 15°C interval. C. prolifera and C. coelothrix are excluded or restricted in distribution on North Sea coasts by lethal winter temperatures, again differences

  13. Manual phased arrays for weld inspections using North American codes

    International Nuclear Information System (INIS)

    Moles, Michael

    2008-01-01

    Phased arrays are primarily a method of generating and receiving ultrasound, not a new technology. In addition, the physics of ultrasound generated by phased arrays is identical to that from conventional monocrystals. Not surprisingly, all the major North American (and some European) codes accept phased arrays, either explicitly or implicitly. However, the technique and procedures needs to be proven, typically by a Performance Demonstration. The ASME (AmeicanSociety for Mechanical Engineers) Section V and API RP2X explicitly accept phased arrays. Three ASME code cases have been written specifically fo manual phased array: Code Cases 2541. 2557 and 2558. Over and above the general requirements of Article 4, these Code Cases require full waveform calibration. This is echoed in ASTM E-2491, a Standard Guide for setting up phased arrays. In addition. details such as focusing and reporting are addressed. The American Petroleum Institute QUTE procedure did not need any modifications to be compatible with manual phased arrays. The American Welding Society (AWS) Structural Welding Code D1.1 implicitly accepts phased arrays. New technologies such as phased arrays can be proven using Annex K. Nonetheless, a manual phased array unit using the standard AWS probe and displaying 45, 60 and 70degrees waveforms would be acceptable for D1.1 a s is . Overall, most major North American codes accept phased arrays, however, the technique and procedures must be proven, often using a Performance Demonstration. (author)

  14. Reactive Halogens in the Marine Boundary Layer (RHaMBLe): the tropical North Atlantic experiments

    OpenAIRE

    J. D. Lee; G. McFiggans; J. D. Allan; A. R. Baker; S. M. Ball; A. K. Benton; L. J. Carpenter; R. Commane; B. D. Finley; M. Evans; E. Fuentes; K. Furneaux; A. Goddard; N. Good; J. F. Hamilton

    2010-01-01

    The NERC UK SOLAS-funded Reactive Halogens in the Marine Boundary Layer (RHaMBLe) programme comprised three field experiments. This manuscript presents an overview of the measurements made within the two simultaneous remote experiments conducted in the tropical North Atlantic in May and June 2007. Measurements were made from two mobile and one ground-based platforms. The heavily instrumented cruise D319 on the RRS Discovery from Lisbon, Portugal to São Vicente, Cape Verde and back to Falmouth...

  15. Polyunsaturated fatty acids in various macroalgal species from north Atlantic and tropical seas

    OpenAIRE

    van Ginneken, Vincent JT; Helsper, Johannes PFG; de Visser, Willem; van Keulen, Herman; Brandenburg, Willem A

    2011-01-01

    Abstract Background In this study the efficacy of using marine macroalgae as a source for polyunsaturated fatty acids, which are associated with the prevention of inflammation, cardiovascular diseases and mental disorders, was investigated. Methods The fatty acid (FA) composition in lipids from seven sea weed species from the North Sea (Ulva lactuca, Chondrus crispus, Laminaria hyperborea, Fucus serratus, Undaria pinnatifida, Palmaria palmata, Ascophyllum nodosum) and two from tropical seas (...

  16. A Reassessment of the Integrated Impact of Tropical Cyclones on Surface Chlorophyll in the Western Subtropical North Atlantic

    Energy Technology Data Exchange (ETDEWEB)

    Foltz, Gregory R.; Balaguru, Karthik; Leung, Lai-Yung R.

    2015-02-28

    The impact of tropical cyclones on surface chlorophyll concentration is assessed in the western subtropical North Atlantic Ocean during 1998–2011. Previous studies in this area focused on individual cyclones and gave mixed results regarding the importance of tropical cyclone-induced mixing for changes in surface chlorophyll. Using a more integrated and comprehensive approach that includes quantification of cyclone-induced changes in mixed layer depth, here it is shown that accumulated cyclone energy explains 22% of the interannual variability in seasonally-averaged (June–November) chlorophyll concentration in the western subtropical North Atlantic, after removing the influence of the North Atlantic Oscillation (NAO). The variance explained by tropical cyclones is thus about 70% of that explained by the NAO, which has well-known impacts in this region. It is therefore likely that tropical cyclones contribute significantly to interannual variations of primary productivity in the western subtropical North Atlantic during the hurricane season.

  17. Tropical Cyclone Exposure for U.S. waters within the North Atlantic Ocean basin, 1900-2013

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent modeled, historical exposure of U.S. offshore and coastal waters to tropical cyclone activity within the North Atlantic Ocean basin. BOEM Outer...

  18. Effects of Image Gently and the North American guidelines: administered activities in children at 13 North American pediatric hospitals.

    Science.gov (United States)

    Fahey, Frederic H; Ziniel, Sonja I; Manion, Dacie; Treves, S Ted

    2015-06-01

    The goal of this investigation was to assess the impact of the publication of the 2010 North American guidelines on the practice of nuclear medicine in children at 13 dedicated pediatric institutions within the United States and Canada by comparing results of similar surveys from 2007 and 2013. In 2013, a follow-up survey was performed of the original 13 dedicated pediatric institutions initially surveyed in 2007. Both surveys inquired about the administered activities for 16 nuclear medicine procedures commonly performed on children. The administered activity per body mass, the maximum activity, and the minimum activity for patients for each procedure were requested from each site. For each parameter the minimum and maximum reported values, as well as the median and the mean, were tabulated. The mean difference in the mean between 2007 and 2013 was calculated, as well as the 95% confidence intervals for the mean administered activity per body mass for both years. The factor of variation used with the previous survey for each parameter was calculated by taking the ratio of the maximum and minimum reported values. For the 8 procedures addressed in the 2010 North American guidelines, the percentage of institutions that were compliant (defined as within 20%) for each parameter were noted for both surveys. Institutions were asked whether they were familiar with "Image Gently," the North American guidelines, and the "Go with the Guidelines" campaign and whether they adjusted their administered activities on the basis of these guidelines. In general, the 13 pediatric institutions have reduced their administered activities in children, particularly for those procedures addressed by the 2010 North American guidelines. The average variability in the activity per body mass and the minimum activity as measured by the factor of variation were substantially reduced by 9.7% (from 3.1 to 2.8) and 24% (from 10.0 to 7.6). The average variability of the maximum activity was

  19. Antimicrobial peptides from the skins of North American frogs.

    Science.gov (United States)

    Conlon, J Michael; Kolodziejek, Jolanta; Nowotny, Norbert

    2009-08-01

    North America is home to anuran species belonging to the families Bufonidae, Eleutherodactylidae, Hylidae, Leiopelmatidae, Ranidae, and Scaphiopodidae but antimicrobial peptides have been identified only in skin secretions and/or skin extracts of frogs belonging to the Leiopelmatidae ("tailed frogs") and Ranidae ("true frogs"). Eight structurally-related cationic alpha-helical peptides with broad-spectrum antibacterial activity, termed ascaphins, have been isolated from specimens of Ascaphus truei (Leiopelmatidae) occupying a coastal range. Characterization of orthologous antimicrobial peptides from Ascaphus specimens occupying an inland range supports the proposal that this population should be regarded as a separate species A. montanus. Ascaphin-8 shows potential for development into a therapeutically valuable anti-infective agent. Peptides belonging to the brevinin-1, esculentin-1, esculentin-2, palustrin-1, palustrin-2, ranacyclin, ranatuerin-1, ranatuerin-2, and temporin families have been isolated from North American ranids. It is proposed that "ranalexins" represent brevinin-1 peptides that have undergone a four amino acid residue internal deletion. Current taxonomic recommendations divide North American frogs from the family Ranidae into two genera: Lithobates and Rana. Cladistic analysis based upon the amino acid sequences of the brevinin-1 peptides provides strong support for this assignment.

  20. Weakening of the North American monsoon with global warming

    Science.gov (United States)

    Pascale, Salvatore; Boos, William R.; Bordoni, Simona; Delworth, Thomas L.; Kapnick, Sarah B.; Murakami, Hiroyuki; Vecchi, Gabriel A.; Zhang, Wei

    2017-11-01

    Future changes in the North American monsoon, a circulation system that brings abundant summer rains to vast areas of the North American Southwest, could have significant consequences for regional water resources. How this monsoon will change with increasing greenhouse gases, however, remains unclear, not least because coarse horizontal resolution and systematic sea-surface temperature biases limit the reliability of its numerical model simulations. Here we investigate the monsoon response to increased atmospheric carbon dioxide (CO2) concentrations using a 50-km-resolution global climate model which features a realistic representation of the monsoon climatology and its synoptic-scale variability. It is found that the monsoon response to CO2 doubling is sensitive to sea-surface temperature biases. When minimizing these biases, the model projects a robust reduction in monsoonal precipitation over the southwestern United States, contrasting with previous multi-model assessments. Most of this precipitation decline can be attributed to increased atmospheric stability, and hence weakened convection, caused by uniform sea-surface warming. These results suggest improved adaptation measures, particularly water resource planning, will be required to cope with projected reductions in monsoon rainfall in the American Southwest.

  1. Canadian hydro potential in the North American market

    International Nuclear Information System (INIS)

    Adams, K.

    2002-01-01

    Canada's hydro potential in the North American energy market was discussed. Canada is a net exporter of electricity in North America, and since 1990, has exported an average of 28 Terawatt hours/year to the United States. More than 65 per cent of these exports were generated from hydro power plants. It was emphasized that significant reductions in greenhouse gases can be achieved if Canadian hydroelectricity is substituted for coal power generation. It was also noted that although there may not be enough hydro capacity to meet all of North America's energy requirements, development of new large hydro resources in Canada could help meet the growing demand for electricity in the United States. Hydro can also complement other renewable energy sources such as wind and solar. The factors that will determine if Canadian hydropower will contribute to the energy demand are market mechanisms such as greenhouse gas credit trading systems which provide incentive for renewable energy projects. In addition, the existing infrastructure must be expanded both east and west within Canada and north and south between Canada and the United States. 5 figs

  2. The North American Energy System: Chapter 3 of SOCCR-2

    Science.gov (United States)

    Gurney, K. R.; Marcotullio, P. J.; McGlynn, E.; Bruhwiler, L.; Davis, K. J.; Davis, S. J.; Engel-Cox, J.; Field, J.; Gately, C.; Kammen, D. M.; McMahon, J.; Morrow, W.; Torrie, R.

    2017-12-01

    North America (Canada, Mexico and the United States), has a large and complex energy system, which in this case includes the extraction and conversion of primary energy sources and their storage, transmission, distribution and ultimate end use in the building, transportation and industrial sectors. The presentation assesses the contribution of this energy system to the carbon cycle. The assessment includes the identification of CO2 emissions from fossil fuel use in the different end use, changes over the past 10 years (since the last SOCCR) and the drivers of change. The assessment focuses on our understanding of the energy trends and system feedback dynamics, key drivers of change as a basis for carbon management. The energy systems' carbon emissions from the North American system are placed in global context and a review of scenarios into the future emissions levels, which demonstrate the requirements for de-carbonization in the medium and longer term.

  3. Modeling and Synthesis Support for the North American Carbon Program

    Science.gov (United States)

    Baskaran, L.; Cook, R. B.; Thornton, P. E.; Post, W. M.; Wilson, B. E.; Dadi, U.

    2007-12-01

    The Modeling and Synthesis Thematic Data Center (MAST-DC) supports the North American Carbon Program by providing data products and data management services needed for modeling and synthesis activities. The overall objective of MAST-DC is to provide advanced data management support to NACP investigators doing modeling and synthesis, thereby freeing those investigators from having to perform data management functions. MAST-DC has compiled a number of data products for North America, including sub-pixel land-water content, daily meteorological data, and soil, land cover, and elevation data. In addition, we have developed an internet-based WebGIS system that enables users to browse, query, display, subset, and download spatial data using a standard web browser. For the mid-continent intensive, MAST-DC is working with a group of data assimilation modelers to generate a consistent set of meteorological data to drive bottom-up models.

  4. The competitive environment of the North American energy marketing industry

    International Nuclear Information System (INIS)

    Tonkin, S.L.

    1999-01-01

    Various issues regarding U.S. wholesale energy marketing were discussed with particular emphasis on how energy marketing is changing industries in North America. In 1998, the energy industry reported a growth in revenue of 26 per cent despite declining natural gas prices. It was emphasized that several major competitive issues need to be addressed by industry competitors in order to operate in this unpredictable market. These issues include profitability, market volatility and mergers and acquisitions. This paper presented a list of the top 10 North American Energy marketers in 1998. Although the number of marketers in the energy sector continues to grow, it is expected that the numbers will decline significantly within three years. This will be due mostly to the continuation of major mergers and acquisitions. It was concluded that in general, energy marketing may become an even more attractive industry because of increasing operating margins. 5 tabs., 2 figs

  5. NRAO Welcomes Taiwan as a New North American ALMA Partner

    Science.gov (United States)

    2008-12-01

    The National Radio Astronomy Observatory (NRAO) has announced a formal agreement enabling Taiwanese astronomers to participate in the North American component of the international ALMA partnership, alongside American and Canadian astronomers. Taiwan's efforts will be led by the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA). ALMA, the Atacama Large Millimeter/submillimeter Array, is the most ambitious ground-based astronomical observatory in history. Currently under construction in Chile’s Atacama Desert at an altitude of 16,500 feet, it promises to revolutionize our understanding of the formation of planets, stars, and galaxies when it begins full science operations early in the next decade. The agreement, signed by the Taipei Economic and Cultural Representative Office and the American Institute in Taiwan, provides for approximately $20 million in ALMA construction funding through the National Science Council (NSC), Taiwan’s equivalent to the US National Science Foundation (NSF) and Canada's National Research Council (NRC), which have jointly funded North America's existing contribution to the international ALMA project. Activities under the agreement will include joint research projects, development projects, collaboration on construction, support of observatory operations and other forms of cooperation. Access to ALMA observing time will be shared, as will membership on advisory committees. “Taiwan is a world-class center for submillimeter-wavelength astronomical research, and we’re delighted that the ALMA project and all its future users will benefit from the resources and expertise that Taiwan’s deepening participation brings to this great, global endeavor,” said Dr. Fred Lo, NRAO's director. This new agreement increases and diversifies Taiwan’s Academia Sinica investment in ALMA beyond the levels achieved through its participation in the East Asian component of the ALMA partnership, which is led by the National Astronomical

  6. Environmental challenges and opportunities of the evolving North American electricity market : Design and legal considerations for North American emissions trading

    International Nuclear Information System (INIS)

    Russell, D.

    2002-06-01

    When considering a multi-pollutant emissions trading system covering Mexico, the United States and Canada, several issues must be looked at. Such a system would result from the changing environment in the electricity sector. An understanding of the architectural elements involved in the design of an emissions trading regime was the stated goal for the preparation of this working paper. In the event of the implementation of a North American emissions trading system, some potential interface issues resulting from the North American Free Trade Agreement (NAFTA) were identified. An overview of the emissions trading systems currently in place in North America and their results was included in a background paper, as well as a description of architectural elements comprised in the design of an emissions trading system, the implications of cross-border harmonization taking into account environmental integrity and economic efficiency, and potential trade issues. This paper was circulated among a broad section of policy experts in environmental matters, and was then discussed at an informal workshop in December 2001, attended by 25 cross-sectoral experts. The author also identified several areas where further work is required. refs., 2 tabs

  7. Standard methods for sampling North American freshwater fishes

    Science.gov (United States)

    Bonar, Scott A.; Hubert, Wayne A.; Willis, David W.

    2009-01-01

    This important reference book provides standard sampling methods recommended by the American Fisheries Society for assessing and monitoring freshwater fish populations in North America. Methods apply to ponds, reservoirs, natural lakes, and streams and rivers containing cold and warmwater fishes. Range-wide and eco-regional averages for indices of abundance, population structure, and condition for individual species are supplied to facilitate comparisons of standard data among populations. Provides information on converting nonstandard to standard data, statistical and database procedures for analyzing and storing standard data, and methods to prevent transfer of invasive species while sampling.

  8. North American NGL exciting times are just ahead

    International Nuclear Information System (INIS)

    Gist, R.L.; Otto, K.W.

    1998-01-01

    Although it is a fairly conservative consulting company, Purvin and Gertz believes that exciting times are just ahead for the North American NGL industry. In the United States, NGL production will be rising rapidly, particularly in the Gulf of Mexico offshore from Louisiana. Demand will also be increasing in many sectors, with the largest increases as petrochemical feedstocks. Similarly, in Canada natural gas export pipelines will result in higher gas and NGL production. Petrochemicals will also play a large role in rapidly rising demand for NGL. Lastly, in Mexico quickly growing demand for natural gas to produce electrical power will push up NGL production

  9. Triskaidekaphobia and North American Residential Real Estate Prices

    OpenAIRE

    James E. Larsen

    2015-01-01

    A previous study led its authors to conclude that superstition impacts price formation for single-family dwellings in the Vancouver area. Houses there with an address that ends in the ¡§unlucky¡¨ number 13 are found to sell at a discount compared to otherwise similar houses. The primary objective of this study is to determine whether the previous results apply in another North American housing market. Hedonic regression is applied to single-family house transactions that occurred in Montgomer...

  10. Potassium incorporation in fruits of South American tropical species

    International Nuclear Information System (INIS)

    Cid, Alberto S.; Anjos, Roberto M.; Macario, Kita D.; Veiga, Rodrigo; Lacerda, Thiago; Velasco, Hugo; Rizzoto, Marcos; Valladares, Daniel; Zamboni, Cibelle B.; Medeiros, Ilca M.A.

    2010-01-01

    Full text: This work proposes the use of a new mathematical model liable for describing the temporal evolution of potassium concentration in fruits of tropical species. Studies of the potassium incorporation are important for two main reasons: a) from the physiological point of view, this flux characterizes the dynamics of the demand of this essential macro nutrient during the gestation period of the fruit; and b) from a radioecological perspective, potassium is a chemical analogue of cesium, particularly of 137 Cs, one of the most important contaminant deposited after accidental releases of radionuclides into the environment. Therefore, describing the potassium incorporation, we can obtain crucial information on how this radionuclide can enter to the human food chain trough fruits. Nutrients accumulation by fruits has been extensively studied for different trees. These investigations have been addressed to evaluate the nutritional status at different stages of the fruit development, estimating the amount of the soil nutrient removal and then to know the better time to program the control and supply of fertilizers. The fruit quality and its aptitude to the conservation are closely related with de nutrient content and the equilibrium between them. The rate of the weight increment in fruit is not uniform. The dry mass accumulation is small in the initial period, later a more expressive increment is observed and, finally during the maturation period, a lower dry mass accumulation was observed. The lengths in days of each one of these grown phases depend of the fruit type. A sigmoid grown model appears to be a very good approximation. The nutrient accumulations follow characteristics patterns along these fruit grown phases. When food-chain model are used to describe the radionuclide key transfer processes for dose assessment, the steady state radionuclide concentration is assumed in each compartment. In many cases that could be a strict simplification of the reality

  11. Potassium incorporation in fruits of South American tropical species

    Energy Technology Data Exchange (ETDEWEB)

    Cid, Alberto S.; Anjos, Roberto M.; Macario, Kita D.; Veiga, Rodrigo; Lacerda, Thiago [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Velasco, Hugo; Rizzoto, Marcos; Valladares, Daniel [Univesidad Nacional de San Luis (Argentina); Zamboni, Cibelle B.; Medeiros, Ilca M.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2010-07-01

    Full text: This work proposes the use of a new mathematical model liable for describing the temporal evolution of potassium concentration in fruits of tropical species. Studies of the potassium incorporation are important for two main reasons: a) from the physiological point of view, this flux characterizes the dynamics of the demand of this essential macro nutrient during the gestation period of the fruit; and b) from a radioecological perspective, potassium is a chemical analogue of cesium, particularly of {sup 137}Cs, one of the most important contaminant deposited after accidental releases of radionuclides into the environment. Therefore, describing the potassium incorporation, we can obtain crucial information on how this radionuclide can enter to the human food chain trough fruits. Nutrients accumulation by fruits has been extensively studied for different trees. These investigations have been addressed to evaluate the nutritional status at different stages of the fruit development, estimating the amount of the soil nutrient removal and then to know the better time to program the control and supply of fertilizers. The fruit quality and its aptitude to the conservation are closely related with de nutrient content and the equilibrium between them. The rate of the weight increment in fruit is not uniform. The dry mass accumulation is small in the initial period, later a more expressive increment is observed and, finally during the maturation period, a lower dry mass accumulation was observed. The lengths in days of each one of these grown phases depend of the fruit type. A sigmoid grown model appears to be a very good approximation. The nutrient accumulations follow characteristics patterns along these fruit grown phases. When food-chain model are used to describe the radionuclide key transfer processes for dose assessment, the steady state radionuclide concentration is assumed in each compartment. In many cases that could be a strict simplification of the

  12. Relationship of boreal summer 10-20-day and 30-60-day intraseasonal oscillation intensity over the tropical western North Pacific to tropical Indo-Pacific SST

    Science.gov (United States)

    Wu, Renguang; Cao, Xi

    2017-06-01

    The present study contrasts interannual variations in the intensity of boreal summer 10-20-day and 30-60-day intraseasonal oscillations (ISOs) over the tropical western North Pacific and their factors. A pronounced difference is found in the relationship of the two ISOs to El Niño-Southern Oscillation. The 10-20-day ISO intensity is enhanced during El Niño developing summer, whereas the 30-60-day ISO intensity is enhanced during La Niña decaying summer. The above different relationship is interpreted as follows. The equatorial central and eastern Pacific SST anomalies modify vertical wind shear, lower-level moisture, and vertical motion in a southeast-northwest oriented band from the equatorial western Pacific to the tropical western North Pacific where the 10-20-day ISOs originate and propagate. These background field changes modulate the amplitude of 10-20-day ISOs. Preceding equatorial central and eastern Pacific SST anomalies induce SST anomalies in the North Indian Ocean in summer, which in turn modify vertical wind shear and vertical motion over the tropical western North Pacific. The modified background fields influence the amplitude of the 30-60-day ISOs when they reach the tropical western North Pacific from the equatorial region. A feedback of ISO intensity on local SST change is identified in the tropical western North Pacific likely due to a net effect of ISOs on surface heat flux anomalies. This feedback is more prominent from the 10-20-day than the 30-60-day ISO intensity change.

  13. Reconnecting fragmented sturgeon populations in North American rivers

    Science.gov (United States)

    Jager, Henriette; Parsley, Michael J.; Cech, Joseph J. Jr.; McLaughlin, R.L.; Forsythe, Patrick S.; Elliott, Robert S.

    2016-01-01

    The majority of large North American rivers are fragmented by dams that interrupt migrations of wide-ranging fishes like sturgeons. Reconnecting habitat is viewed as an important means of protecting sturgeon species in U.S. rivers because these species have lost between 5% and 60% of their historical ranges. Unfortunately, facilities designed to pass other fishes have rarely worked well for sturgeons. The most successful passage facilities were sized appropriately for sturgeons and accommodated bottom-oriented species. For upstream passage, facilities with large entrances, full-depth guidance systems, large lifts, or wide fishways without obstructions or tight turns worked well. However, facilitating upstream migration is only half the battle. Broader recovery for linked sturgeon populations requires safe “round-trip” passage involving multiple dams. The most successful downstream passage facilities included nature-like fishways, large canal bypasses, and bottom-draw sluice gates. We outline an adaptive approach to implementing passage that begins with temporary programs and structures and monitors success both at the scale of individual fish at individual dams and the scale of metapopulations in a river basin. The challenge will be to learn from past efforts and reconnect North American sturgeon populations in a way that promotes range expansion and facilitates population recovery.

  14. Characterisation of North American Brucella isolates from marine mammals.

    Directory of Open Access Journals (Sweden)

    Adrian M Whatmore

    Full Text Available Extension of known ecological niches of Brucella has included the description of two novel species from marine mammals. Brucella pinnipedialis is associated predominantly with seals, while two major Brucella ceti clades, most commonly associated with porpoises or dolphins respectively, have been identified. To date there has been limited characterisation of Brucella isolates obtained from marine mammals outside Northern European waters, including North American waters. To address this gap, and extend knowledge of the global population structure and host associations of these Brucella species, 61 isolates from marine mammals inhabiting North American waters were subject to molecular and phenotypic characterisation enabling comparison with existing European isolates. The majority of isolates represent genotypes previously described in Europe although novel genotypes were identified in both B. ceti clades. Harp seals were found to carry B. pinnipedialis genotypes previously confined to hooded seals among a diverse repertoire of sequence types (STs associated with this species. For the first time Brucella isolates were characterised from beluga whales and found to represent a number of distinct B. pinnipedialis genotypes. In addition the known host range of ST27 was extended with the identification of this ST from California sea lion samples. Finally the performance of the frequently used diagnostic tool Bruce-ladder, in differentiating B. ceti and B. pinnipedialis, was critically assessed based on improved knowledge of the global population structure of Brucella associated with marine mammals.

  15. Comparison of arch forms between Turkish and North American

    Directory of Open Access Journals (Sweden)

    Ahmet A. Celebi

    2016-04-01

    Full Text Available ABSTRACT Objective: The aim of this study was to clarify the morphological differences in the mandibular arches of Turkish and North American white subjects. Methods: The sample included 132 Turkish (34 Class I, 58 Class II, and 40 Class III and 160 North American (60 Class I, 50 Class II, and 50 Class III subjects. The most facial portion of 13 proximal contact areas was digitized from photocopied images of patients' mandibular dental arches. Clinical bracket points were calculated for each tooth based on mandibular tooth thickness data. Four linear and two proportional measurements were taken. The subjects were grouped according to arch form types (tapered, ovoid and square in order to have frequency distribution compared between ethnic groups in each Angle classification. Results: The Turkish group showed significantly lower molar depth and more significant molar width-depth (W/D ratio in all three Angle classifications. On the other hand, the Turkish group also showed a significantly larger intercanine width in Class III malocclusion and intermolar width in Class II malocclusion. The most frequent arch forms seen were the ovoid arch form in the Turkish group and the tapered form in the white group. Conclusions: Our results demonstrate that when treating Turkish patients, one should expect to use preformed ovoid arch form orthodontic wires in a significant percentage of patients.

  16. Characterisation of North American Brucella isolates from marine mammals.

    Science.gov (United States)

    Whatmore, Adrian M; Dawson, Claire; Muchowski, Jakub; Perrett, Lorraine L; Stubberfield, Emma; Koylass, Mark; Foster, Geoffrey; Davison, Nicholas J; Quance, Christine; Sidor, Inga F; Field, Cara L; St Leger, Judy

    2017-01-01

    Extension of known ecological niches of Brucella has included the description of two novel species from marine mammals. Brucella pinnipedialis is associated predominantly with seals, while two major Brucella ceti clades, most commonly associated with porpoises or dolphins respectively, have been identified. To date there has been limited characterisation of Brucella isolates obtained from marine mammals outside Northern European waters, including North American waters. To address this gap, and extend knowledge of the global population structure and host associations of these Brucella species, 61 isolates from marine mammals inhabiting North American waters were subject to molecular and phenotypic characterisation enabling comparison with existing European isolates. The majority of isolates represent genotypes previously described in Europe although novel genotypes were identified in both B. ceti clades. Harp seals were found to carry B. pinnipedialis genotypes previously confined to hooded seals among a diverse repertoire of sequence types (STs) associated with this species. For the first time Brucella isolates were characterised from beluga whales and found to represent a number of distinct B. pinnipedialis genotypes. In addition the known host range of ST27 was extended with the identification of this ST from California sea lion samples. Finally the performance of the frequently used diagnostic tool Bruce-ladder, in differentiating B. ceti and B. pinnipedialis, was critically assessed based on improved knowledge of the global population structure of Brucella associated with marine mammals.

  17. Underestimation of the Tambora effects in North American taiga ecosystems

    Science.gov (United States)

    Gennaretti, Fabio; Boucher, Etienne; Nicault, Antoine; Gea-Izquierdo, Guillermo; Arseneault, Dominique; Berninger, Frank; Savard, Martine M.; Bégin, Christian; Guiot, Joel

    2018-03-01

    The Tambora eruption (1815 AD) was one of the major eruptions of the last two millennia and has no equivalents over the last two centuries. Here, we collected an extensive network of early meteorological time series, climate simulation data and numerous, well-replicated proxy records from Eastern Canada to analyze the strength and the persistence of the Tambora impact on the regional climate and forest processes. Our results show that the Tambora impacts on the terrestrial biosphere were stronger than previously thought, and not only affected tree growth and carbon uptake for a longer period than registered in the regional climate, but also determined forest demography and structure. Increased tree mortality, four times higher than the background level, indicates that the Tambora climatic impact propagated to influence the structure of the North American taiga for several decades. We also show that the Tambora signal is more persistent in observed data (temperature, river ice dynamics, forest growth, tree mortality) than in simulated ones (climate and forest-growth simulations), indicating that our understanding of the mechanisms amplifying volcanic perturbations on climates and ecosystems is still limited, notably in the North American taiga.

  18. Women in perfusion: a survey of North American female perfusionists.

    Science.gov (United States)

    Brewer, Stacey L; Mongero, Linda B

    2013-09-01

    Perfusion as a career has long been dominated by men (American Board of Cardiovascular Perfusion, Booklet of information since 1975). Women represent 33.3% of the present workforce in North America (1187 certified women). In the 1900s, fewer than 20% of women participated in the labor force compared with 75% today and growing (1). In addition women make only 77 cents for every dollar that men earn and the more education a woman has, the greater the disparity in her wages (2). Only 53% of employers provide at least some replacement pay during periods of maternity leave (2). The purpose of this survey was to poll women in perfusion to evaluate concerns and opinions in their careers and to compare this with the female labor force. In October 2011, a 40-question survey (surveymonkey.com) was made available to all female perfusionists in North American by postcard mailing through the American Board of Cardiovascular Perfusion. There were 538 responses to the survey, which is 45% of all female certified perfusionists in North America. A total of 32.6% of the survey participants have been in perfusion for more than 20 years and 75% are staff perfusionists, working for a hospital (59.5%) rather than a contract group (36.7%). A total of 44.7% of women who had children during their employment were out on leave 10 weeks or less. A total of 95.9% feel they miss important family functions as a result of their work schedules and 63% consider themselves under moderate stress. Direct supervision of the participants by men occurred in 76.5% of cases, and 68.2% felt that they were treated with the same respect as male coworkers. Nonetheless, 50.9% felt discriminated against because of gender. This survey suggests that the female perfusionists in North America share the same difficulties as women in the labor force. The role of women in society in general is clearly changing. Female perfusionists will be part of that change. Seventy percent of those surveyed would recommend perfusion

  19. North American pipelines supply/demand update: challenges and opportunities

    International Nuclear Information System (INIS)

    Gopal, J.

    2002-01-01

    The author began the presentation by providing a little definition of forecasting supply, demand and price as applied to the natural gas industry, indicating that it is both science and art. An integrated grid in North America, the natural gas sector modeling relates to supply basins, demand centers and pipes includes the United States, Canada and Mexico. Some of the considerations are: huge demand from proposed power generation, conservation, and drilling impacts, as well as pipeline capacity. A chart displaying the North American model was explained. The author discussed the technically recoverable natural gas resources as well as the estimates in both Canada and the United States. The next section deals with exploration and development of frontier resources and power plant licensing, with emphasis on power plants in California. The generation assumptions for the Western Systems Coordinating Council from the Energy Commission are reviewed, placing the numbers in their proper perspective. California natural gas supply by source is examined, followed by regional natural gas spot price. The wellhead natural gas prices for North America and for the Lower 48 states are presented. The author indicates that additional pipeline capacity is required to meet the growing demand. Several factors have to be considered: the number of power plants, when and where; pipeline capacity (how much); regulations; slack capacity; cost of slack capacity, and supply. The concluding remarks touched upon the availability of gas resources, the environmental issues that affect demand, hub services that enhance service flexibility and reliability, and pipeline capacity and storage. 2 tabs., 15 figs

  20. 76 FR 73608 - Reliability Technical Conference, North American Electric Reliability Corporation, Public Service...

    Science.gov (United States)

    2011-11-29

    ... or municipal authority play in forming your bulk power system reliability plans? b. Do you support..., North American Electric Reliability Corporation (NERC) Nick Akins, CEO of American Electric Power (AEP..., EL11-62-000] Reliability Technical Conference, North American Electric Reliability Corporation, Public...

  1. Survey on current hydrotherapy use among North American burn centers.

    Science.gov (United States)

    Davison, Peter G; Loiselle, Frederick B; Nickerson, Duncan

    2010-01-01

    The authors have reviewed hydrotherapy practices in North American burn centers and described the epidemiology of hydrotherapy-associated nosocomial infections. A web-based survey was distributed to the directors of all burn care facilities listed by the American Burn Association. Questions addressed aspects of practice, including the method, additives, disposable liners, decontamination practices, nosocomial pathogens, and perceptions regarding the "ideal" method of hydrotherapy. The response rate was 44%, 59 of 142 centers, or 827 of 1900 beds. Hydrotherapy is regularly used by 83% of centers. Among these centers, 10% use exclusively immersion hydrotherapy (IH), 54% use exclusively shower cart hydrotherapy (SCH), and 35% use a combination of IH and SCH. Disposable liners are used at 80% of centers. Tap water alone is used by 51% of centers, 27% add detergent, 16% chlorhexidine, and 7% povidone-iodine. The majority of centers (57%) do not routinely culture their hydrotherapy equipment, 20% culture weekly, 7% monthly, and 17% less than once per month. Directors believe that Pseudomonas aeruginosa, methicillin-sensitive Staphylococcus aureus, and methicillin-resistant S. aureus are the most common nosocomial pathogens, followed by Acinetobacter species and Candida albicans. The relative frequency of occurrence of the first three pathogens did not vary with regard to the hydrotherapy method used. Given the opportunity to redesign, 45% of burn unit directors would implement SCH only, 42% a combination of SCH and IH, 2% exclusively IH, and 11% no hydrotherapy or bedside irrigation only. The prevalence of hydrotherapy use at North American burn centers has decreased since 1990 (83% vs 95%), yet continues to be used at the majority of centers. The use of IH has also declined (55% vs 81%). The trend away from the exclusive use of IH will likely continue, because more centers incorporate showering methods.

  2. 77 FR 10479 - North American Free Trade Agreement, Article 1904; NAFTA Panel Reviews; First Request for Panel...

    Science.gov (United States)

    2012-02-22

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free Trade Agreement... Section of the NAFTA Secretariat pursuant to Article 1904 of the North American Free Trade Agreement... American Free Trade Agreement (``Agreement'') established a mechanism to replace domestic judicial review...

  3. 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.

  4. Distribution and Magnitude of Dinitrogen Fixation in the Eastern Tropical North Pacific Oxygen Deficient Zone.

    Science.gov (United States)

    Selden, C.; Mulholland, M. R.; Widner, B.; Bernhardt, P. W.; Macías Tapia, A.; Jayakumar, A.

    2016-12-01

    The Eastern Tropical North Pacific Ocean (ETNP) hosts one of the world's three major open ocean oxygen deficient zones (ODZs). Hotspots for fixed nitrogen (N) loss processes, ODZs have classically been discounted as areas of significant dinitrogen (N2) fixation, the microbe-mediated reduction of N2 to ammonium (NH4+), which has historically been ascribed primarily to euphotic, nutrient-deplete tropical waters. Challenging this paradigm, active expression of nifH (the dinitrogen reductase structural gene) has recently been documented in the ETNP, Eastern Tropical South Pacific, and Arabian Sea ODZs, implying a closer coupling of fixed nitrogen input and loss processes than previously thought. Here, we report rates of N­2 fixation measured in the ETNP ODZ along vertical gradients of oxygen, light, and dissolved N concentrations. Detailed vertical profiles of N2 fixation rates and dissolved N concentrations made within the ODZ were compared with similar profiles from oxic waters outside the ODZ. In addition, different organic carbon sources were investigated as potential rate-limiting factors for N2 fixation in sub-euphotic waters. By establishing the magnitude and distribution of N­2 fixation in the ETNP ODZ, this study contributes to current understanding of N cycling in anoxic and aphotic waters, and serves to elucidate nuances in the global N budget, enabling more accurate biogeochemical modeling. Understanding these processes in present day ODZs is crucial for predicting how ongoing anthropogenic intensification of coastal ODZs will alter biogeochemical cycles in the future.

  5. LGMD2I in a North American population

    Directory of Open Access Journals (Sweden)

    White Alexander J

    2007-11-01

    Full Text Available Abstract Background There is a marked variation in clinical phenotypes that have been associated with mutations in FKRP, ranging from severe congenital muscular dystrophies to limb-girdle muscular dystrophy type 2I (LGMD2I. Methods We screened the FKRP gene in two cohorts totaling 87 patients with the LGMD phenotype. Results The c.826C>A, p.L276I mutation was present in six patients and a compound heterozygote mutation in a seventh patient. Six patients had a mild LGMD2I phenotype, which resembles that of Becker muscular dystrophy. The other patient had onset before the age of 3 years, and thus may follow a more severe course. Conclusion These findings suggest that LGMD2I may be common in certain North American populations. This diagnosis should be considered early in the evaluation of LGMD.

  6. North American free trade and the European situation compared.

    Science.gov (United States)

    Weintraub, S

    1992-01-01

    The author analyzes and compares the trade situation in the European Community (EC) with the North American Free Trade Agreement (NAFTA). He finds that "while both the EC and NAFTA are designed to provide trade preferences to the member countries, the two groupings differ markedly in other respects. The Treaty of Rome, establishing what is now the EC, consciously used economic means to foster political cohesion in Western Europe; whereas, the NAFTA negotiations seek free trade rather than more comprehensive economic integration precisely to minimize political content. The EC contains many social provisions absent from the NAFTA discussions, the most important of which is the right of migration from one EC country to another." The effects of NAFTA on the economy of Mexico and on Mexican migration to the United States are also assessed. excerpt

  7. Energy Efficiency in the North American Existing Building Stock

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This report presents the findings of a new assessment of the techno-economic and policy-related efficiency improvement potential in the North American building stock conducted as part of a wider appraisal of existing buildings in member states of the International Energy Agency. It summarizes results and provides insights into the lessons learned through a broader global review of best practice to improve the energy efficiency of existing buildings. At this time, the report is limited to the USA because of the large size of its buildings market. At a later date, a more complete review may include some details about policies and programs in Canada. If resources are available an additional comprehensive review of Canada and Mexico may be performed in the future.

  8. Sequelae of radiation facial epilation (North American Hiroshima maiden syndrome)

    International Nuclear Information System (INIS)

    Rosen, I.B.; Walfish, P.G.

    1989-01-01

    Radiation for benign problems of the head and neck area has been uniformly recognized as unacceptable practice. This includes epilation for facial hirsutism. Twelve such patients, recently encountered, have characteristic radiodermatitis facies and have demonstrated multisite neoplastic involvement--including skin, thyroid, parathyroid, salivary gland, oral cavity, facial skeleton, and breast--and have also undergone extensive dermatologic treatment of complications of radiodermatitis. There was one cancer death, and three patients are alive with cancer. Such patients have a superficial resemblance to the Hiroshima maiden group of young women who survived atomic bombing and experienced severe facial burns, necessitating extensive plastic surgery. As atomic survivors they are at increased risk for cancer of thyroid, salivary gland, lung, breast, bone marrow, and gastrointestinal tract. The North American Hiroshima maiden should warrant easy clinical recognition and require lifetime scrutiny for multisite neoplastic disease

  9. HYDROCEPHALUS IN THREE JUVENILE NORTH AMERICAN BLACK BEARS (URSUS AMERICANUS).

    Science.gov (United States)

    Ferguson, Sylvia H; Novak, Janelle; Hecht, Silke; Craig, Linden E

    2016-06-01

    Hydrocephalus has been reported in a variety of species, including the North American black bear ( Ursus americanus ). This report describes three cases of hydrocephalus in this species from wild bears aged 3-4 mo considered retrospectively from necropsy records of one institution. Clinical signs included cortical blindness and ataxia. Primary gross findings were doming of the skull, gyri compression and flattening, and lateral ventricle dilation. Two cases had severe bilateral ventricular dilation with loss of the septum pellucidum; atrophy of the surrounding corpus callosum; and bilateral periventricular tears involving the caudate nuclei, internal capsule, and adjacent cerebrum. Histologically, the cases with periventricular tearing had severe axonal loss and degeneration, malacia, hemorrhage, and variable periventricular astrocytosis. All cases were likely congenital, given the bears' age and lack of an apparent acquired obstruction.

  10. North American Indian rock art and hallucinogenic drugs.

    Science.gov (United States)

    Wellmann, K F

    1978-04-14

    It is proposed that the aboriginal rock paintings in two areas of North America may have been produced by shamans while they were under the influence of hallucinogenic agents derived from plants. The first of these areas is the Chumash and Yokuts Indian region of California, where polychrome paintings show designs similar to those visualized during the trance induced by decoctions of jimsonweed (Datura species). The second area is the lower Pecos River region of Texas, where shamanistic figures display traits considered to be conceptual analogues of the mescal bean (Sophora secundiflora) cult as practiced during historic times by Great Plains Indians. Although the evidence is only circumstantial, the proposed connections between these rock drawings and mind-expanding pharmacologic compounds fit well into the documented relationship that encompasses hallucinogenic drugs and certain movable objects of pre-Columbian American art.

  11. North American Natural Gas Markets: Selected technical studies

    International Nuclear Information System (INIS)

    Huntington, H.G.; Schuler, G.E.

    1989-04-01

    The Energy Modeling Forum (EMF) was established in 1976 at Stanford University to provide a structural framework within which energy experts, analysts, and policymakers could meet to improve their understanding of critical energy problems. The ninth EMF study, North American Natural Gas Markets, was conducted by a working group comprised of leading natural gas analysts and decision-makers from government, private companies, universities, and research and consulting organizations. The EMF 9 working group met five times from October 1986 through June 1988 to discuss key issues and analyze natural gas markets. This third volume includes technical papers that support many of the conclusions discussed in the EMF 9 summary report (Volume 1) and full working group report (Volume 2). These papers discuss the results from the individual models as well as some nonmodeling analysis related to US natural gas imports and industrial natural gas demand. Individual papers have been processed separately for inclusion in the Energy Science and Technology Database

  12. Antioxidant capacities of ten edible North American plants.

    Science.gov (United States)

    Acuña, Ulyana Muñoz; Atha, Daniel E; Ma, Jun; Nee, Michael H; Kennelly, Edward J

    2002-02-01

    The EtOAc extract obtained from ten edible North American plants, Acorus calamus, Clintonia borealis, Gaultheria shallon, Juniperus osteosperma, Opuntia polyacantha, Prunus americana, Prunus virginiana, Sambucus cerulea, Sorbus americana and Vaccinium parvifolium, were tested in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical assay. High antioxidant activity was obtained from the extracts of three fruits, Gaultheria shallon, Sambucus cerulea and Prunus americana and one extracted rhizome, Acorus calamus. Catechin and epicatechin, potent polyphenolic antioxidants, were identified in the EtOAc extracts of Gaultheria shallon and Sambucus cerulea by reversed-phase thin-layer chromatography (TLC) and reversed-phase high-performance liquid chromatography (HPLC). Copyright 2002 John Wiley & Sons, Ltd.

  13. North American Natural Gas Markets: Selected technical studies. Volume 3

    Energy Technology Data Exchange (ETDEWEB)

    Huntington, H.G.; Schuler, G.E. [eds.

    1989-04-01

    The Energy Modeling Forum (EMF) was established in 1976 at Stanford University to provide a structural framework within which energy experts, analysts, and policymakers could meet to improve their understanding of critical energy problems. The ninth EMF study, North American Natural Gas Markets, was conducted by a working group comprised of leading natural gas analysts and decision-makers from government, private companies, universities, and research and consulting organizations. The EMF 9 working group met five times from October 1986 through June 1988 to discuss key issues and analyze natural gas markets. This third volume includes technical papers that support many of the conclusions discussed in the EMF 9 summary report (Volume 1) and full working group report (Volume 2). These papers discuss the results from the individual models as well as some nonmodeling analysis related to US natural gas imports and industrial natural gas demand. Individual papers have been processed separately for inclusion in the Energy Science and Technology Database.

  14. North American Natural Gas Markets: Selected technical studies

    Energy Technology Data Exchange (ETDEWEB)

    Huntington, H.G.; Schuler, G.E. (eds.)

    1989-04-01

    The Energy Modeling Forum (EMF) was established in 1976 at Stanford University to provide a structural framework within which energy experts, analysts, and policymakers could meet to improve their understanding of critical energy problems. The ninth EMF study, North American Natural Gas Markets, was conducted by a working group comprised of leading natural gas analysts and decision-makers from government, private companies, universities, and research and consulting organizations. The EMF 9 working group met five times from October 1986 through June 1988 to discuss key issues and analyze natural gas markets. This third volume includes technical papers that support many of the conclusions discussed in the EMF 9 summary report (Volume 1) and full working group report (Volume 2). These papers discuss the results from the individual models as well as some nonmodeling analysis related to US natural gas imports and industrial natural gas demand. Individual papers have been processed separately for inclusion in the Energy Science and Technology Database.

  15. A plan for the North American Bat Monitoring Program (NABat)

    Science.gov (United States)

    Loeb, Susan C.; Rodhouse, Thomas J.; Ellison, Laura E.; Lausen, Cori L.; Reichard, Jonathan D.; Irvine, Kathryn M.; Ingersoll, Thomas E.; Coleman, Jeremy; Thogmartin, Wayne E.; Sauer, John R.; Francis, Charles M.; Bayless, Mylea L.; Stanley, Thomas R.; Johnson, Douglas H.

    2015-01-01

    The purpose of the North American Bat Monitoring Program (NABat) is to create a continent-wide program to monitor bats at local to rangewide scales that will provide reliable data to promote effective conservation decisionmaking and the long-term viability of bat populations across the continent. This is an international, multiagency program. Four approaches will be used to gather monitoring data to assess changes in bat distributions and abundances: winter hibernaculum counts, maternity colony counts, mobile acoustic surveys along road transects, and acoustic surveys at stationary points. These monitoring approaches are described along with methods for identifying species recorded by acoustic detectors. Other chapters describe the sampling design, the database management system (Bat Population Database), and statistical approaches that can be used to analyze data collected through this program.

  16. North American natural gas pipeline and supply update

    International Nuclear Information System (INIS)

    Molyneaux, M.

    1999-01-01

    A series of overhead viewgraphs accompanied this presentation which presented an update of North American natural gas supply. Some of the graphs depicted the following: (1) natural gas consumption in the United States, (2) U.S. imports of Canadian natural gas, (3) natural gas prices differential: Henry Hub versus Empress, (4) natural gas production in the U.S., and (5) Baker Hughes active rig count, U.S. gas rigs. First Energy's view of U.S. natural gas supply is that the estimate of 50.0 Bcf/d for U.S. domestic production is looking too high. The first quarter 1999 exit production rates are behind expectations. U.S. domestic natural gas expenditure budgets are still down by more than 40 per cent compared to 1998 levels. The impact that this will have on prices was discussed. 21 figs

  17. Impacts of the north and tropical Atlantic Ocean on the Antarctic Peninsula and sea ice.

    Science.gov (United States)

    Li, Xichen; Holland, David M; Gerber, Edwin P; Yoo, Changhyun

    2014-01-23

    In recent decades, Antarctica has experienced pronounced climate changes. The Antarctic Peninsula exhibited the strongest warming of any region on the planet, causing rapid changes in land ice. Additionally, in contrast to the sea-ice decline over the Arctic, Antarctic sea ice has not declined, but has instead undergone a perplexing redistribution. Antarctic climate is influenced by, among other factors, changes in radiative forcing and remote Pacific climate variability, but none explains the observed Antarctic Peninsula warming or the sea-ice redistribution in austral winter. However, in the north and tropical Atlantic Ocean, the Atlantic Multidecadal Oscillation (a leading mode of sea surface temperature variability) has been overlooked in this context. Here we show that sea surface warming related to the Atlantic Multidecadal Oscillation reduces the surface pressure in the Amundsen Sea and contributes to the observed dipole-like sea-ice redistribution between the Ross and Amundsen-Bellingshausen-Weddell seas and to the Antarctic Peninsula warming. Support for these findings comes from analysis of observational and reanalysis data, and independently from both comprehensive and idealized atmospheric model simulations. We suggest that the north and tropical Atlantic is important for projections of future climate change in Antarctica, and has the potential to affect the global thermohaline circulation and sea-level change.

  18. Synoptic Scale North American Weather Tracks and the Formation of North Atlantic Windstorms

    Science.gov (United States)

    Baum, A. J.; Godek, M. L.

    2014-12-01

    Each winter, dozens of fatalities occur when intense North Atlantic windstorms impact Western Europe. Forecasting the tracks of these storms in the short term is often problematic, but long term forecasts provide an even greater challenge. Improved prediction necessitates the ability to identify these low pressure areas at formation and understand commonalities that distinguish these storms from other systems crossing the Atlantic, such as where they develop. There is some evidence that indicates the majority of intense windstorms that reach Europe have origins far west, as low pressure systems that develop over the North American continent. This project aims to identify the specific cyclogenesis regions in North America that produce a significantly greater number of dangerous storms. NOAA Ocean Prediction Center surface pressure reanalysis maps are used to examine the tracks of storms. Strong windstorms are characterized by those with a central pressure of less than 965 hPa at any point in their life cycle. Tracks are recorded using a coding system based on source region, storm track and dissipation region. The codes are analyzed to determine which region contains the most statistical significance with respect to strong Atlantic windstorm generation. The resultant set of codes also serves as a climatology of North Atlantic extratropical cyclones. Results indicate that a number of windstorms favor cyclogenesis regions off the east coast of the United States. A large number of strong storms that encounter east coast cyclogenesis zones originate in the central mountain region, around Colorado. These storms follow a path that exits North America around New England and subsequently travel along the Canadian coast. Some of these are then primed to become "bombs" over the open Atlantic Ocean.

  19. Factors influencing reporting and harvest probabilities in North American geese

    Science.gov (United States)

    Zimmerman, G.S.; Moser, T.J.; Kendall, W.L.; Doherty, P.F.; White, Gary C.; Caswell, D.F.

    2009-01-01

    We assessed variation in reporting probabilities of standard bands among species, populations, harvest locations, and size classes of North American geese to enable estimation of unbiased harvest probabilities. We included reward (US10,20,30,50, or100) and control (0) banded geese from 16 recognized goose populations of 4 species: Canada (Branta canadensis), cackling (B. hutchinsii), Ross's (Chen rossii), and snow geese (C. caerulescens). We incorporated spatially explicit direct recoveries and live recaptures into a multinomial model to estimate reporting, harvest, and band-retention probabilities. We compared various models for estimating harvest probabilities at country (United States vs. Canada), flyway (5 administrative regions), and harvest area (i.e., flyways divided into northern and southern sections) scales. Mean reporting probability of standard bands was 0.73 (95 CI 0.690.77). Point estimates of reporting probabilities for goose populations or spatial units varied from 0.52 to 0.93, but confidence intervals for individual estimates overlapped and model selection indicated that models with species, population, or spatial effects were less parsimonious than those without these effects. Our estimates were similar to recently reported estimates for mallards (Anas platyrhynchos). We provide current harvest probability estimates for these populations using our direct measures of reporting probability, improving the accuracy of previous estimates obtained from recovery probabilities alone. Goose managers and researchers throughout North America can use our reporting probabilities to correct recovery probabilities estimated from standard banding operations for deriving spatially explicit harvest probabilities.

  20. Toward 2000 - potential changes facing the North American gas industry

    International Nuclear Information System (INIS)

    Baron, R.L.; Godec, M.L.

    1997-01-01

    Rapid changes in U.S. gas market developments and key factors that are likely to change future market outlook were reviewed. Currently, the biggest challenges facing the North American gas industry are deregulation in the electric power industry, technological advances, Canadian exports, environmental considerations, and new sources of natural gas from Mexico and Sable Island. Forces driving the natural gas demand include technological advances, growth in gas demand by electric utilities, and expansion of pipeline capacity. Uncertainties and threats to natural gas use include the rising cost of environmental compliance, the continued use of coal for power generation, and the Alliance Pipeline development. Technological advances such as 3-D seismic, horizontal drilling, improved completion techniques, longer-life bits, improved control systems, and reduced project cycle time, have been credited for producers now finding more gas reserves per well drilled than a decade ago. Present estimates of technically recoverable gas resources in North America run to about 2,500 trillion cubic feet

  1. A North American Hydroclimate Synthesis (NAHS) of the Common Era

    Science.gov (United States)

    Rodysill, Jessica R.; Anderson, Lesleigh; Cronin, Thomas M.; Jones, Miriam C.; Thompson, Robert S.; Wahl, David B.; Willard, Debra A.; Addison, Jason A.; Alder, Jay R.; Anderson, Katherine H.; Anderson, Lysanna; Barron, John A.; Bernhardt, Christopher E.; Hostetler, Steven W.; Kehrwald, Natalie M.; Khan, Nicole S.; Richey, Julie N.; Starratt, Scott W.; Strickland, Laura E.; Toomey, Michael R.; Treat, Claire C.; Wingard, G. Lynn

    2018-03-01

    This study presents a synthesis of century-scale hydroclimate variations in North America for the Common Era (last 2000 years) using new age models of previously published multiple proxy-based paleoclimate data. This North American Hydroclimate Synthesis (NAHS) examines regional hydroclimate patterns and related environmental indicators, including vegetation, lake water elevation, stream flow and runoff, cave drip rates, biological productivity, assemblages of living organisms, and salinity. Centennial-scale hydroclimate anomalies are obtained by iteratively sampling the proxy data on each of thousands of age model realizations and determining the fractions of possible time series indicating that the century-smoothed data was anomalously wet or dry relative to the 100 BCE to 1900 CE mean. Results suggest regionally asynchronous wet and dry periods over multidecadal to centennial timescales and frequent periods of extended regional drought. Most sites indicate drying during previously documented multicentennial periods of warmer Northern Hemisphere temperatures, particularly in the western U.S., central U.S., and Canada. Two widespread droughts were documented by the NAHS: from 50 BCE to 450 CE and from 800 to 1100 CE. Major hydroclimate reorganizations occurred out of sync with Northern Hemisphere temperature variations and widespread wet and dry anomalies occurred during both warm and cool periods. We present a broad assessment of paleoclimate relationships that highlights the potential influences of internal variability and external forcing and supports a prominent role for Pacific and Atlantic Ocean dynamics on century-scale continental hydroclimate.

  2. Comparison of exposure response relationship of atrasentan between North American and Asian populations

    DEFF Research Database (Denmark)

    Heerspink, Hiddo J L; Makino, Hirofumi; Andress, Dennis

    2017-01-01

    AIMS: The selective endothelin (ET) A receptor antagonist atrasentan has been shown to lower albuminuria in North American and Asian patients with type 2 diabetes and nephropathy. As drug responses to many drugs may differ between North American and Asian populations, we assessed the influence...... change in albuminuria. Bodyweight change, a proxy of fluid retention, was used as a safety endpoint. Pharmacodynamics were determined in Asians (N = 77) and North Americans (N = 134). Atrasentan plasma concentration was measured in 161 atrasentan-treated patients. RESULTS: Mean albuminuria reduction...... in Asian, compared to North American, patients was, respectively, -34.4% vs -26.3% for 0.75 mg/d ( P  = .44) and -48.0% vs -28.9% for 1.25 mg/d ( P  = .035). Bodyweight gain did not differ between North American and Asian populations. Atrasentan plasma concentrations were higher in Asians compared to North...

  3. Can north american fish passage tools work for South american migratory fishes?

    Directory of Open Access Journals (Sweden)

    Claudio Rafael Mariano Baigún

    Full Text Available In North America, the Numerical Fish Surrogate (NFS is used to design fish bypass systems for emigrating juvenile salmon as they migrate from hatchery outfalls and rearing habitats to adult habitat in the oceans. The NFS is constructed of three linked modules: 1 a computational fluid dynamics model describes the complex flow fields upstream of dams at a scale sufficiently resolved to analyze, understand and forecast fish movement, 2 a particle tracking model interpolates hydraulic information from the fixed nodes of the computational fluid model mesh to multiple locations relevant to migrating fish, and 3 a behavior model simulates the cognition and behavior of individual fish in response to the fluid dynamics predicted by the computational fluid dynamics model. These three modules together create a virtual reality where virtual fish exhibit realistic dam approach behaviors and can be counted at dam exits in ways similar to the real world. Once calibrated and validated with measured fish movement and passage data, the NFS can accurately predict fish passage proportions with sufficient precision to allow engineers to select one optimum alternative from among many competing structural or operational bypass alternatives. Although South American fish species are different from North American species, it is likely that the basic computational architecture and numerical methods of the NFS can be used for fish conservation in South America. Consequently, the extensive investment made in the creation of the NFS need not be duplicated in South America. However, its use in South America will require that the behavioral response of the continent's unique fishes to hydrodynamic cues must be described, codified and tested before the NFS can be used to conserve fishes by helping design efficient South American bypass systems. To this end, we identify studies that could be used to describe the movement behavior of South American fishes of sufficient detail

  4. A climatological model of North Indian Ocean tropical cyclone genesis, tracks and landfall

    Science.gov (United States)

    Wahiduzzaman, Mohammad; Oliver, Eric C. J.; Wotherspoon, Simon J.; Holbrook, Neil J.

    2017-10-01

    Extensive damage and loss of life can be caused by tropical cyclones (TCs) that make landfall. Modelling of TC landfall probability is beneficial to insurance/re-insurance companies, decision makers, government policy and planning, and residents in coastal areas. In this study, we develop a climatological model of tropical cyclone genesis, tracks and landfall for North Indian Ocean (NIO) rim countries based on kernel density estimation, a generalised additive model (GAM) including an Euler integration step, and landfall detection using a country mask approach. Using a 35-year record (1979-2013) of tropical cyclone track observations from the Joint Typhoon Warning Centre (part of the International Best Track Archive Climate Stewardship Version 6), the GAM is fitted to the observed cyclone track velocities as a smooth function of location in each season. The distribution of cyclone genesis points is approximated by kernel density estimation. The model simulated TCs are randomly selected from the fitted kernel (TC genesis), and the cyclone paths (TC tracks), represented by the GAM together with the application of stochastic innovations at each step, are simulated to generate a suite of NIO rim landfall statistics. Three hindcast validation methods are applied to evaluate the integrity of the model. First, leave-one-out cross validation is applied whereby the country of landfall is determined by the majority vote (considering the location by only highest percentage of landfall) from the simulated tracks. Second, the probability distribution of simulated landfall is evaluated against the observed landfall. Third, the distances between the point of observed landfall and simulated landfall are compared and quantified. Overall, the model shows very good cross-validated hindcast skill of modelled landfalling cyclones against observations in each of the NIO tropical cyclone seasons and for most NIO rim countries, with only a relatively small difference in the percentage of

  5. Variability of tropical cyclone rapid intensification in the North Atlantic and its relationship with climate variations

    Science.gov (United States)

    Wang, Chunzai; Wang, Xidong; Weisberg, Robert H.; Black, Michael L.

    2017-12-01

    The paper uses observational data from 1950 to 2014 to investigate rapid intensification (RI) variability of tropical cyclones (TCs) in the North Atlantic and its relationships with large-scale climate variations. RI is defined as a TC intensity increase of at least 15.4 m/s (30 knots) in 24 h. The seasonal RI distribution follows the seasonal TC distribution, with the highest number in September. Although an RI event can occur anywhere over the tropical North Atlantic (TNA), there are three regions of maximum RI occurrence: (1) the western TNA of 12°N-18°N and 60°W-45°W, (2) the Gulf of Mexico and the western Caribbean Sea, and (3) the open ocean southeast and east of Florida. RI events also show a minimum value in the eastern Caribbean Sea north of South America—a place called a hurricane graveyard due to atmospheric divergence and subsidence. On longer time scales, RI displays both interannual and multidecadal variability, but RI does not show a long-term trend due to global warming. The top three climate indices showing high correlations with RI are the June-November ENSO and Atlantic warm pool indices, and the January-March North Atlantic oscillation index. It is found that variabilities of vertical wind shear and TC heat potential are important for TC RI in the hurricane main development region, whereas relative humidity at 500 hPa is the main factor responsible for TC RI in the eastern TNA. However, the large-scale oceanic and atmospheric variables analyzed in this study do not show an important role in TC RI in the Gulf of Mexico and the open ocean southeast and east of Florida. This suggests that other factors such as small-scale changes of oceanic and atmospheric variables or TC internal processes may be responsible for TC RI in these two regions. Additionally, the analyses indicate that large-scale atmospheric and oceanic variables are not critical to TC genesis and formation; however, once a tropical depression forms, large-scale climate

  6. Educational technology infrastructure and services in North American medical schools.

    Science.gov (United States)

    Kamin, Carol; Souza, Kevin H; Heestand, Diane; Moses, Anna; O'Sullivan, Patricia

    2006-07-01

    To describe the current educational technology infrastructure and services provided by North American allopathic medical schools that are members of the Association of American Medical Colleges (AAMC), to present information needed for institutional benchmarking. A Web-based survey instrument was developed and administered in the fall of 2004 by the authors, sent to representatives of 137 medical schools and completed by representatives of 88, a response rate of 64%. Schools were given scores for infrastructure and services provided. Data were analyzed with one-way analyses of variance, chi-square, and correlation coefficients. There was no difference in the number of infrastructure features or services offered based on region of the country, public versus private schools, or size of graduating class. Schools implemented 3.0 (SD = 1.5) of 6 infrastructure items and offered 11.6 (SD = 4.1) of 22 services. Over 90% of schools had wireless access (97%), used online course materials for undergraduate medical education (97%), course management system for graduate medical education (95%) and online teaching evaluations (90%). Use of services differed across the undergraduate, graduate, and continuing medical education continuum. Outside of e-portfolios for undergraduates, the least-offered services were for services to graduate and continuing medical education. The results of this survey provide a benchmark for the level of services and infrastructure currently supporting educational technology by AAMC-member allopathic medical schools.

  7. North American energy relationships : clean energy and climate action : a North American collaboration : draft paper for discussion

    International Nuclear Information System (INIS)

    Russell, D.

    2009-12-01

    This paper discussed energy and climate policies and programs aimed at reducing greenhouse gas (GHG) emissions in North America. The aim of the study was to determine how energy production and use will impact policy responses to climate change and the development of clean energy technologies. Energy sectors in Canada, the United States and Mexico were outlined, and the relationships between the different countries and their energy systems were discussed. Energy policy drivers and infrastructure in each of the 3 countries were also discussed. The influence of energy security on energy trading, clean energy technology, and climate change policy was also investigated in order to identify barriers to future cooperation between the countries. Emerging areas of cooperation were outlined. Potential climate policy scenarios were reviewed, and the implications of a more highly integrated North American energy and climate policy were discussed. The study indicated that increased linkages between the Canadian and United States systems are likely in the future. 62 refs., 11 tabs., 7 figs.

  8. Prosopis pod production - comparison of North American, South American, Hawaiian, and African germplasm in young plantations

    Energy Technology Data Exchange (ETDEWEB)

    Felker, P.; Clark, P.R.; Osborn, J.F.; Cannell, G.H.

    Prosopis pod production was compared in 3 field trials in southern California, i.e., a typical orchard planting, an irrigation trial, and a heat/drought stress trial. Thirteen species representing North American, South American, Hawaiian, and African germplasm were evaluated. Hawaiian and African accessions were eliminated from the irrigation trial by a minus 5/sup 0/C temperature. The most productive pod producers were P. velutina accessions from southern Arizona. In the fifth season, 5 trees of the most productive accession, i.e. P. velutina 32 had a mean pod production of 7.2 kg/tree with a range of 3.2-12.2 kg/tree. P. chilensis and P. alba trees of the same age were much larger but had less pod production. Pod production estimates of 3000-4000 kg/ha were obtained in the dry irrigation treatment by P. velutina 20 which received 370 mm rainfall in the year preceding harvest.

  9. 78 FR 77449 - GSA Approves Renewal of North American Numbering Council Charter Through September 20, 2015

    Science.gov (United States)

    2013-12-23

    ... on issues related to North American Numbering Plan (NANP) administration. The NANP is the telephone numbering plan for the United States and its territories, Canada, Bermuda, and 17 Caribbean nations. The... annual evaluations of the current North American Numbering Plan Administrator, the Pooling Administrator...

  10. The Luneburg Sustainable University Project in International Comparison: An Assessment against North American Peers

    Science.gov (United States)

    Beringer, Almut

    2007-01-01

    Purpose: To assess the Luneburg Sustainable University Project (the Project) in a non-European international context; to relate the project scholarly approach to selected scholarly and practice-oriented North American sustainability in higher education (SHE) methods; to analyze project innovations against North American initiatives.…

  11. Teaching Media and Methods in Marketing: European and North American Universities

    Science.gov (United States)

    Vila, Natalia; Kuster, Ines

    2009-01-01

    This article aims to examine the most widely used teaching media and methods in university education. To achieve this objective, international research has been carried out among 135 marketing teachers from North American and European universities. The study shows that North American teachers use more traditional media and participatory methods…

  12. Comparison of exposure response relationship of atrasentan between North American and Asian populations

    NARCIS (Netherlands)

    Heerspink, Hiddo J. L.; Makino, Hirofumi; Andress, Dennis; Brennan, John J.; Correa-Rotter, Ricardo; Coll, Blai; Davis, Justin W.; Idler, Ken; Kohan, Donald E.; Liu, Mohan; Perkovic, Vlado; Remuzzi, Giuseppe; Tobe, Sheldon W.; Toto, Robert; Parving, Hans-Henrik; de Zeeuw, Dick

    Aims: The selective endothelin (ET) A receptor antagonist atrasentan has been shown to lower albuminuria in North American and Asian patients with type 2 diabetes and nephropathy. As drug responses to many drugs may differ between North American and Asian populations, we assessed the influence of

  13. 22 CFR 41.59 - Professionals under the North American Free Trade Agreement.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Professionals under the North American Free Trade Agreement. 41.59 Section 41.59 Foreign Relations DEPARTMENT OF STATE VISAS VISAS: DOCUMENTATION OF... Professionals under the North American Free Trade Agreement. (a) Requirements for classification as a NAFTA...

  14. 78 FR 57838 - North American Free Trade Agreement Binational Panel Reviews

    Science.gov (United States)

    2013-09-20

    ... DEPARTMENT OF COMMERCE International Trade Administration [Secretariat File No. USA-MEX-2011- 1904-02] North American Free Trade Agreement Binational Panel Reviews AGENCY: NAFTA Secretariat, United... Decision and Order of the North American Free Trade Agreement (NAFTA) Binational Panel dated August 6, 2013...

  15. 19 CFR 102.25 - Textile or apparel products under the North American Free Trade Agreement.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Textile or apparel products under the North American Free Trade Agreement. 102.25 Section 102.25 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION... or apparel products under the North American Free Trade Agreement. In connection with a claim for...

  16. 48 CFR 18.119 - Use of patented technology under the North American Free Trade Agreement.

    Science.gov (United States)

    2010-10-01

    ... under the North American Free Trade Agreement. 18.119 Section 18.119 Federal Acquisition Regulations... Available Acquisition Flexibilities 18.119 Use of patented technology under the North American Free Trade Agreement. Requirement to obtain authorization prior to use of patented technology may be waived in...

  17. 78 FR 37880 - Mazda North American Operations, Grant of Petition for Decision of Inconsequential Noncompliance

    Science.gov (United States)

    2013-06-24

    ...: Mazda North American Operations (MNAO),\\1\\ on behalf of Mazda Motor Corporation of Hiroshima, Japan (Mazda),\\2\\ has determined that certain Mazda brand motor vehicles manufactured between 2000 and 2012 for...\\ Mazda North American Operations is a U.S. company that manufacturers and imports motor vehicles. \\2...

  18. 77 FR 65051 - Mazda North American Operations, Receipt of Petition for Decision of Inconsequential Noncompliance

    Science.gov (United States)

    2012-10-24

    ...: Mazda North American Operations (MNAO),\\1\\ on behalf of Mazda Motor Corporation of Hiroshima, Japan (Mazda),\\2\\ has determined that certain Mazda brand motor vehicles manufactured between 2007 and 2012 for... North American Operations, is a U.S. company that manufactures and imports motor vehicles. \\2\\ Mazda...

  19. 77 FR 59703 - Mazda North American Operations, Receipt of Petition for Decision of Inconsequential Noncompliance

    Science.gov (United States)

    2012-09-28

    ...: Mazda North American Operations (MNAO),\\1\\ on behalf of Mazda Motor Corporation of Hiroshima, Japan (Mazda),\\2\\ has determined that certain Mazda brand motor vehicles manufactured between 2000 and 2012 for...\\ Mazda North American Operations, is a U.S. company that manufacturers and imports motor vehicles. \\2...

  20. North American Forest Futures 2018-2090: Scenarios for Building a More Resilient Forest Sector

    Science.gov (United States)

    David N. Bengston; Jonathan Peck; Robert Olson; Melissa Barros; Richard A. Birdsey; Daniel R. Williams; Juan Carlos Leyva Reyes; Francisco José Zamudio

    2018-01-01

    North American forests and forest management institutions are experiencing a wide range of significant ecological disturbances and socioeconomic changes, which point to the need for enhanced resilience. A critical capacity for resilience in institutions is strategic foresight. This article reports on a project of the North American Forest Commission to use Futures...

  1. Contraceptive usage patterns in North American medical students

    Science.gov (United States)

    Rowen, Tami S.; Smith, James F.; Eisenberg, Michael L.; Breyer, Benjamin N.; Drey, Eleanor A.; Shindel, Alan W.

    2013-01-01

    Background Previous studies indicate that the sexual beliefs and mores of students in medical professions may influence their capacity to care for patients’ sexuality and contraception issues. Students also represent a large sample of reproductive-age individuals. In this study, we examined contraceptive usage patterns in North American medical students. Study Design Students using online medical student social and information networks enrolled in allopathic and osteopathic medical schools in North America between February and July of 2008 were invited to participate via email and published announcements in an Internet-based survey consisting of a questionnaire that assessed ethnodemographic factors, year in school and sexual history. We also collected information about current use of contraceptive and barrier methods. Descriptive statistics and logistic regression were utilized to analyze responses. Results Among our 2269 complete responses, at least one form of contraception was being utilized by 71% of men and 76% of women. Condoms were the most popular form of contraceptive, utilized by 1011 respondents (50% of men and 40% of women). Oral contraceptive pills were the contraceptive of choice for 34% of men and 41% of women. Decreased rates of contraception use were associated with being black or Asian, not being in a relationship and having more sexual dysfunction in female respondents. Students who reported comfort discussing sexual issues with patients were more likely to use effective contraceptive methods themselves. Ten percent of this of sexually active medical students was not currently using contraception. Conclusions There are significant differences in contraceptive use based on demographics, even at the highest education levels. The personal contraception choices of medical students may influence their ability to accurately convey information about contraception to their patients. In addition, medical students may personally benefit from improved

  2. Tensile deformation and failure of North American porcupine quills

    Energy Technology Data Exchange (ETDEWEB)

    Chou, S.F.; Overfelt, R.A., E-mail: overfra@auburn.edu

    2011-12-01

    Although the mechanical properties of some keratin-based biological materials have been extensively studied (i.e., wool) and others are beginning to be studied (e.g., horn, hooves and avian quills), data on the properties of porcupine quill are less common. Porcupine quill is a keratin-based biological material composed of a cylindrical outer shell with an inner foam core. The present paper reports on the physical characteristics, tensile properties and fracture behavior of North American porcupine quills conditioned at relative humidities of 65% and 100%. Increasing the water content decreased the tensile stiffness and strength and increased the strain at fracture of the porcupine quills. The tensile fracture strength of porcupine quill was found to be 146 MPa at 65% RH and 60 MPa at 100% RH. Although these values compare favorably with reported values for African porcupine quill, reported values of the tensile strengths of wool with similar moisture contents are considerably higher. The initial moduli of porcupine quill (2700 MPa at 65% RH and 1000 MPa at 100% RH) compare favorably to those reported for wool but are considerably less than previous reports for African porcupine quill. The engineering strains at fracture were measured as 25% at 65% RH and 49% at 100% RH and these values are also comparable to other keratin-based mammalian materials. Scanning electron microscopy of the fracture surfaces of porcupine quills revealed that the cylindrical outer shells of quills are composed of 2-3 layers with distinctly different fracture characteristics, especially when the samples contain 100% RH. The outer layer of the porcupine quill shell appears to resist the plasticizing effects of moisture and appears to exhibit considerably less ductility than the inner layers, perhaps due to the presence of hydrophobic lipids in the outer layer. Highlights: {yields} We characterize the tensile properties of north American porcupine quill. {yields} Elastic modulus, tensile

  3. Aggressive delinquency among north American indigenous adolescents: Trajectories and predictors.

    Science.gov (United States)

    Sittner, Kelley J; Hautala, Dane

    2016-01-01

    Aggressive delinquency is a salient social problem for many North American Indigenous (American Indian, Canadian First Nations) communities, and can have deleterious consequences later in life. Yet there is a paucity of research on Indigenous delinquency. Group-based trajectory modeling is used to prospectively examine trajectories of aggressive delinquency over the course of adolescence using data from 646 Indigenous adolescents from a single culture, spanning the ages of 10-19. Five aggression trajectory groups were identified, characterized by different levels and ages of onset and desistence: non-offenders (22.1%), moderate desistors (19.9%), adolescent-limited offenders (22.2%), high desistors (16.7%), and chronic offenders (19.2%). Using the social development model of antisocial behavior, we selected relevant risk and protective factors predicted to discriminate among those most and least likely to engage in more aggressive behavior. Higher levels of risk (i.e., parent rejection, delinquent peers, substance use, and early dating) in early adolescence were associated with being in the two groups with the highest levels of aggressive delinquency. Positive school adjustment, the only significant protective factor, was associated with being in the lowest aggression trajectory groups. The results provide important information that could be used in developing prevention and intervention programs, particularly regarding vulnerable ages as well as malleable risk factors. Identifying those youth most at risk of engaging in higher levels of aggression may be key to preventing delinquency and reducing the over-representation of Indigenous youth in the justice system. © 2015 Wiley Periodicals, Inc.

  4. Centennial changes in North Pacific anoxia linked to tropical trade winds

    Science.gov (United States)

    Deutsch, Curtis; Berelson, William; Thunell, Robert; Weber, Thomas; Tems, Caitlin; McManus, James; Crusius, John; Ito, Taka; Baumgartner, Timothy; Ferreira, Vicente; Mey, Jacob; van Geen, Alexander

    2014-01-01

    Climate warming is expected to reduce oxygen (O2) supply to the ocean and expand its oxygen minimum zones (OMZs). We reconstructed variations in the extent of North Pacific anoxia since 1850 using a geochemical proxy for denitrification (δ15N) from multiple sediment cores. Increasing δ15N since ~1990 records an expansion of anoxia, consistent with observed O2 trends. However, this was preceded by a longer declining δ15N trend that implies that the anoxic zone was shrinking for most of the 20th century. Both periods can be explained by changes in winds over the tropical Pacific that drive upwelling, biological productivity, and O2 demand within the OMZ. If equatorial Pacific winds resume their predicted weakening trend, the ocean’s largest anoxic zone will contract despite a global O2 decline.

  5. Tropical Pacific Climate, Carbon, and Ocean Biogeochemical Response to the Central American Seaway in a GFDL Earth System Model

    Science.gov (United States)

    Sentman, L. T.; Dunne, J. P.; Stouffer, R. J.; Krasting, J. P.; Wittenberg, A. T.; Toggweiler, J. R.; Broccoli, A. J.

    2017-12-01

    To explore the tropical Pacific climate, carbon, and ocean biogeochemical response to the shoaling and closure of the Central American Seaway during the Pliocene (5.3-2.6 Ma), we performed a suite of sensitivity experiments using the Geophysical Fluid Dynamics Laboratory Earth System Model, GFDL-ESM2G, varying only the seaway widths and sill depths. These novel ESM simulations include near-final closure of the seaway with a very narrow, 1º grid cell wide opening. Net mass transport through the seaway into the Caribbean is 20.5-23.1 Sv with a deep seaway, but only 14.1 Sv for the wide/shallow seaway because of the inter-basin bi-directional horizontal mass transport. Seaway transport originates from the Antarctic Circumpolar Current in the Pacific and rejoins it in the South Atlantic, reducing the Indonesian Throughflow and transporting heat and salt southward into the South Atlantic, in contrast to present-day and previous seaway simulations. Tropical Pacific mean climate and interannual variability is sensitive to the seaway shoaling, with the largest response to the wider/deeper seaway. In the tropical Pacific, the top 300-m warms 0.4-0.8°C, the equatorial east-west sea surface temperature gradient increases, the north-south sea surface temperature asymmetry at 110°W decreases, thermocline deepens 5-11 m, and the east-west thermocline gradient increases. In the Niño-3 region, ENSO amplitude increases, skewed toward more cold (La Niña) events, El Niño and La Niña develops earlier ( 3 months), the annual cycle weakens and the semi-annual and interannual cycles strengthen from increased symmetry of the north-south sea surface temperature gradient, and atmospheric global teleconnections strengthen with the seaway. The increase in global ocean overturning with the seaway results in a younger average ocean ideal age, reduced dissolved inorganic carbon inventory and marine net primary productivity, and altered inter-basin patterns of surface sediment carbonate

  6. Decrease of tropical cyclone genesis frequency in the western North Pacific since 1960s

    Science.gov (United States)

    Hu, Feng; Li, Tim; Liu, Jia; Bi, Mingyu; Peng, Melinda

    2018-03-01

    Tropical cyclone (TC) genesis frequency in the western North Pacific (WNP) during 1960-2014 shows a step-by-step decrease on interdecadal timescale, in accordance to the phase of the Interdecadal Pacific Oscillation (IPO). The environmental parameters responsible for the interdecadal change of TC genesis frequency were investigated. It was found that vertical wind shear especially the zonal wind shear plays a critical role, while other parameters such as sea surface temperature (SST), vertical velocity, divergence, humidity and maximum potential intensity cannot explain the step-by-step decrease of TC genesis frequency. A further diagnosis shows that the interdecadal change of vertical wind shear is caused by SST and associated rainfall pattern changes across the Indo-Pacific Ocean. A stronger warming in the Indian Ocean/western Pacific from 1960-1976 to 1977-1998 led to enhanced convection over the Maritime Continent and thus strengthened vertical shear over the key TC genesis region in the WNP. A La Nina-like SST pattern change from 1977-1998 to 1999-2014 led to a strengthened Walker circulation in the tropical Pacific, which further enhanced the vertical shear and decreased TC genesis frequency in the WNP.

  7. Conservation status of imperiled north American freshwater and diadromous fishes

    Science.gov (United States)

    Jelks, H.L.; Walsh, S.J.; Burkhead, N.M.; Contreras-Balderas, Salvador; Diaz-Pardo, E.; Hendrickson, D.A.; Lyons, J.; Mandrak, N.E.; McCormick, F.; Nelson, Joseph S.; Platania, Steven P.; Porter, B.A.; Renaud, C.B.; Schmitter-Soto, J. J.; Taylor, E.B.; Warren, M.L.

    2008-01-01

    This is the third compilation of imperiled (i.e., endangered, threatened, vulnerable) plus extinct freshwater and diadromous fishes of North America prepared by the American Fisheries Society's Endangered Species Committee. Since the last revision in 1989, imperilment of inland fishes has increased substantially. This list includes 700 extant taxa representing 133 genera and 36 families, a 92% increase over the 364 listed in 1989. The increase reflects the addition of distinct populations, previously non-imperiled fishes, and recently described or discovered taxa. Approximately 39% of described fish species of the continent are imperiled. There are 230 vulnerable, 190 threatened, and 280 endangered extant taxa, and 61 taxa presumed extinct or extirpated from nature. Of those that were imperiled in 1989, most (89%) are the same or worse in conservation status; only 6% have improved in status, and 5% were delisted for various reasons. Habitat degradation and nonindigenous species are the main threats to at-risk fishes, many of which are restricted to small ranges. Documenting the diversity and status of rare fishes is a critical step in identifying and implementing appropriate actions necessary for their protection and management.

  8. Energy and the NAFTA [North American Free Trade Agreement

    International Nuclear Information System (INIS)

    Plourde, A.

    1993-01-01

    A review is presented of the implications of the North American Free Trade Agreement (NAFTA) for the energy industry. This agreement expands the coverage accorded to energy in the Canada-US Free Trade Agreement (FTA), and is of limited significance with respect to Canada-US relations, but is quite important to these two countries' energy trade with Mexico. With respect to Canada-US trade, the most important departure from the FTA is that NAFTA tends to ensure a greater degree of respect for the terms of negotiated contracts, in particular by requiring the parties to make efforts to secure compliance with the national treatment provisions of the NAFTA by subfederal regulatory entities. Mexico's constitution severely restricts foreign participation in the activities of its energy industries, including basic petrochemicals. While NAFTA accomodates these restrictions, Canadian and US companies will have opportunities to bid on contracts for goods and services and construction in the Mexican energy sector on an equal footing with their Mexican counterparts. NAFTA also provides expanded opportunities for foreign investment and control in electricity generation for own-use, cogeneration and public service purposes. The parties are explicitly allowed to extend activity incentives to their respective oil and gas industries. 9 refs

  9. Runoff simulation using the North American regional reanalysis data set

    International Nuclear Information System (INIS)

    Rasmussen, P.; Kim, S.J.; Moore, A.; Choi, W.

    2008-01-01

    In part due to concerns about the impact of climate change, there has been an increased interest in hydrological modelling of watersheds in Canada. Most of Canada is sparsely populated and a recurrent problem is the lack of quality weather data that are often not available at the sites of interest. Continuous hydrologic models require input of temperature and precipitation as a minimum, and often additional information such as solar radiation and humidity. It is not uncommon that such information must be obtained by interpolating information from weather stations located far outside the watershed. The difficulty in obtaining good calibration results is obvious in such cases. The recently released North American Regional Reanalysis (NARR) data set has been found to be in reasonable agreement with surface observations. NARR surface data, including those commonly required in hydrologic models, are available on a 32 km by 32 km grid which is appropriate for hydrologic modelling. The objective of this paper is to investigate whether hydrologic models for selected watersheds in Central Canada can be adequately calibrated using NARR data rather than conventional station information. For the specific case studies considered here, it is found that calibration with NARR weather information is quite acceptable and similar to what can be obtained using interpolated weather station data. (author)

  10. Observed Decrease of North American Winter Temperature Variability

    Science.gov (United States)

    Rhines, A. N.; Tingley, M.; McKinnon, K. A.; Huybers, P. J.

    2015-12-01

    There is considerable interest in determining whether temperature variability has changed in recent decades. Model ensembles project that extratropical land temperature variance will detectably decrease by 2070. We use quantile regression of station observations to show that decreasing variability is already robustly detectable for North American winter during 1979--2014. Pointwise trends from GHCND stations are mapped into a continuous spatial field using thin-plate spline regression, resolving small-scales while providing uncertainties accounting for spatial covariance and varying station density. We find that variability of daily temperatures, as measured by the difference between the 95th and 5th percentiles, has decreased markedly in winter for both daily minima and maxima. Composites indicate that the reduced spread of winter temperatures primarily results from Arctic amplification decreasing the meridional temperature gradient. Greater observed warming in the 5th relative to the 95th percentile stems from asymmetric effects of advection during cold versus warm days; cold air advection is generally from northerly regions that have experienced greater warming than western or southwestern regions that are generally sourced during warm days.

  11. Implementation of aggregation in the North American power industry

    International Nuclear Information System (INIS)

    Feldman, R.; Williams, G.

    1998-01-01

    One key to the impact of deregulation being transmitted to residential customers is the successful formation of aggregation groups and their expansion to include different classes of customers with convergent usage interests. This activity currently is being sponsored not only by for-profit brokerage entities, but also by associations of not-for-profit corporations such as hospitals and universities and by countries. The issues presented fall into several categories. (1) Technical rate taking--feasibility of making appropriate arrangements for alternative supply to consumers on a basis which appropriately reflects customer characteristics and also confers benefit on them all; (2) Legal--Compatibility of proposed arrangements with FERC wholesale regulation under Order No. 888 and emerging state regulation under the different restructuring regimes which their state utility commissions are implementing; (3) Marketing/Sociopolitical--Utilization of modern marketing techniques to effect the political consensus which is a precursor of alternative aggregation arrangements; (4) Financing--identification of capital costs; techniques for financing such costs, including monetization of the savings to be realized. The presentation will extrapolate the potential future significance of aggregation as a force in both restructuring and the development of merchant power projects. It will also assess the extent to which institutional, legal, technical or financial factors may modify the ultimate significance of aggression in the North American Power Industry

  12. Recent changes in the ranges of North American birds

    Science.gov (United States)

    Robbins, C.S.; Ilyichev, V.D.; Gavrilov, V.M.

    1985-01-01

    The North American Breeding Bird Survey has provided an annual index of population change since 1966. About 2400 randomly distributed roadside routes of 50 three-minute stops each provide the basic data for computer analysis. One of the reports produced shows the percentage of routes on which each species is encountered in each state and each Canadian province. This percentage is used to show expansion and contraction of breeding range and also important changes in frequency of encounter within various portions of the range of each species. Most of the recent changes in range fall in one of these 7 categories: (1) introduced species; (2) species given special protection; (3) species benefiting from artificial feeding in winter; (4) species taking advantage of shelterbelts; (5) species nesting on large highway bridges and dams; (6) species that feed on grain lost during mechanical harvesting: and (7) species losing habitat as a result of urban expansion. Examples of each category are supported by changes in the rate of encounter.

  13. Endocranial Morphology of the Extinct North American Lion (Panthera atrox).

    Science.gov (United States)

    Cuff, Andrew R; Stockey, Christopher; Goswami, Anjali

    2016-01-01

    The extinct North American lion (Panthera atrox) is one of the largest felids (Mammalia, Carnivora) to have ever lived, and it is known from a plethora of incredibly well-preserved remains. Despite this abundance of material, there has been little research into its endocranial anatomy. CT scans of a skull of P. atrox from the Pleistocene La Brea Tar pits were used to generate the first virtual endocranium for this species and to elucidate previously unknown details of its brain size and gross structure, cranial nerves, and inner-ear morphology. Results show that its gross brain anatomy is broadly similar to that of other pantherines, although P. atrox displays less cephalic flexure than either extant lions or tigers, instead showing a brain shape that is reminiscent of earlier felids. Despite this unusual reduction in flexure, the estimated absolute brain size for this specimen is one of the largest reported for any felid, living or extinct. Its encephalization quotient (brain size as a fraction of the expected brain mass for a given body mass) is also larger than that of extant lions but similar to that of the other pantherines. The advent of CT scans has allowed nondestructive sampling of anatomy that cannot otherwise be studied in these extinct lions, leading to a more accurate reconstruction of endocranial morphology and its evolution. © 2017 S. Karger AG, Basel.

  14. Biological activities of undescribed North American lichen species.

    Science.gov (United States)

    Yeash, Erik A; Letwin, Lyndon; Malek, Lada; Suntres, Zacharias; Knudsen, Kerry; Christopher, Lew P

    2017-11-01

    Lichens provide a large array of compounds with the potential for pharmaceutical development. In the present study, extracts from three previously undescribed North American lichen species were examined for antioxidant, antibacterial and anticancer activities. The results from this study demonstrated the following: (i) Acarospora socialis ethanol extract exhibited significant DPPH antioxidant scavenging activities, which were concentration dependent; (ii) acetone and ethyl acetate extracts of Xanthoparmelia mexicana inhibited Gram-positive bacteria but had no effect on Gram-negative bacteria; X. mexicana acetone extract yielded a minimum inhibitory concentration (MIC) of 20.9 µg mL -1 against Staphylococcus aureus, and 41.9 µg mL -1 against Enterococcus faecalis; (iii) acetone extract of Lobothallia alphoplaca inhibited growth of cultured breast cancer MCF-7 cells with an effective concentration (EC 50 ) of 87 µg mL -1 ; the MCF-7 cell cycle appears arrested in the G2 phase, whereas the DNA synthesis cell cycle (S) may be inhibited. New lichen species that possess strong biological activities have been identified. These lichens comprise secondary metabolites that possess antioxidant, antibacterial and anticancer properties. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  15. Characterization of the North American beaver (Castor canadensis) papillomavirus genome.

    Science.gov (United States)

    Rogovskyy, Artem S; Chen, Zigui; Burk, Robert D; Bankhead, Troy

    2014-01-10

    The papillomaviruses comprise a large group of viruses that cause proliferations of the stratified squamous epithelium of skin and mucosa in a variety of animals. An earlier report identified a novel papillomavirus of the North American beaver, Castor canadensis (CcanPV1) that was associated with cutaneous exophytic lesions. In the current study, we determined the sequence of the complete 7435 basepair genome of CcanPV1. The genome contains an Upstream Regulatory Region located between the end of L1 and the start of E6, and seven canonical papillomavirus open reading frames encoding five early (E6, E7, E1, E2, and E4) and two late (L2 and L1) proteins. No E5 open reading frame was detected. Phylogenetic analysis of the CcanPV1 genome places the virus between the genera Kappapapillomavirus and Mupapillomavirus. Analyses of the papillomavirus genomes detected in different species of the order Rodentia indicate these viruses do not form a monophyletic clade. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Accounts of famous North American Wolves, Canis lupus

    Science.gov (United States)

    Gipson, P.S.; Ballard, W.B.

    1998-01-01

    We examined historical accounts of 59 famous North American Gray Wolves (Canis lupus) reported during the late nineteenth and early twentieth centuries. Fifty of the 59 wolves were purportedly responsible for great losses to livestock, but for 29 reports, evidence suggested that ???2 wolves (e.g., packs) were responsible for the purported kills; in addition, seven wolves had traits that suggested they were hybrids with dogs, and one wolf was probably not from the area where the damage purportedly occurred. Reported livestock losses, especially to Longhorn cattle, from individual wolves appeared excessively high in relation to current literature. Most famous wolves were old and/or impaired from past injuries: 19 were reportedly ???10 years old, 18 had mutilated feet from past trap injuries, and one had a partially severed trachea from being in a snare. Old age and physical impairments probably contributed to livestock depredations by some famous wolves. Several accounts appeared exaggerated, inaccurate, or fabricated. Historical accounts of famous wolves should be interpreted with great caution, especially when considering impacts of wolf reintroductions or when modeling predation rates.

  17. Generic versus brand-name North American topical glaucoma drops.

    Science.gov (United States)

    Mammo, Zaid N; Flanagan, John G; James, David F; Trope, Graham E

    2012-02-01

    To determine whether brand-name glaucoma drops differ from generic equivalents in bottle design, viscosity, surface tension, and volume in North America. Experimental study. We studied 5 bottles each of 11 kinds of glaucoma drops. Density-based calculations of drop volume were assessed using 0.1 mg analytic balance. Viscosity was measured using rotational rheometery. Bottle tip diameter was measured using 0.05 mm Vernier calipers. Surface tension was measured using a Fisher Scientific (Ottawa, ON) tensiometer. For the American brand-name Timoptic XE, the average drop volume was 38 ± 3.1 μL versus 24 ± 1.5 μL of Timolol GFS (p brand-name Timoptic XE, the average drop volume was 42 ± 4.0 μL versus 25 ± 2 μL of timolol maleate EX (p brand-name Timoptic drop volume was 28 ± 1.4 μL versus 35 ± 1.9 μL Apo-Timop (p brand-name Timoptic delivered significantly smaller drop volumes than generic Apo-Timop. Careful consideration should be given to drop viscosity and bottle design when generic ophthalmic products are evaluated for interchangeability and market entry. Copyright © 2012 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  18. The North American Free Trade Agreement (NAFTA) and Mexican nursing.

    Science.gov (United States)

    Squires, Allison

    2011-03-01

    In the context of nurse migration, experts view trade agreements as either vehicles for facilitating migration or as contributing to brain-drain phenomena. Using a case study design, this study explored the effects of the North American Free Trade Agreement (NAFTA) on the development of Mexican nursing. Drawing results from a general thematic analysis of 48 interviews with Mexican nurses and 410 primary and secondary sources, findings show that NAFTA changed the relationship between the State and Mexican nursing. The changed relationship improved the infrastructure capable of producing and monitoring nursing human resources in Mexico. It did not lead to the mass migration of Mexican nurses to the United States and Canada. At the same time, the economic instability provoked by the peso crisis of 1995 slowed the implementation of planned advances. Subsequent neoliberal reforms decreased nurses' security as workers by minimizing access to full-time positions with benefits, and decreased wages. This article discusses the linkages of these events and the effects on Mexican nurses and the development of the profession. The findings have implications for nursing human resources policy-making and trade in services.

  19. Mountain building triggered late cretaceous North American megaherbivore dinosaur radiation.

    Directory of Open Access Journals (Sweden)

    Terry A Gates

    Full Text Available Prior studies of Mesozoic biodiversity document a diversity peak for dinosaur species in the Campanian stage of the Late Cretaceous, yet have failed to provide explicit causal mechanisms. We provide evidence that a marked increase in North American dinosaur biodiversity can be attributed to dynamic orogenic episodes within the Western Interior Basin (WIB. Detailed fossil occurrences document an association between the shift from Sevier-style, latitudinally arrayed basins to smaller Laramide-style, longitudinally arrayed basins and a well substantiated decreased geographic range/increased taxonomic diversity of megaherbivorous dinosaur species. Dispersal-vicariance analysis demonstrates that the nearly identical biogeographic histories of the megaherbivorous dinosaur clades Ceratopsidae and Hadrosauridae are attributable to rapid diversification events within restricted basins and that isolation events are contemporaneous with known tectonic activity in the region. SymmeTREE analysis indicates that megaherbivorous dinosaur clades exhibited significant variation in diversification rates throughout the Late Cretaceous. Phylogenetic divergence estimates of fossil clades offer a new lower boundary on Laramide surficial deformation that precedes estimates based on sedimentological data alone.

  20. Mountain building triggered late cretaceous North American megaherbivore dinosaur radiation.

    Science.gov (United States)

    Gates, Terry A; Prieto-Márquez, Albert; Zanno, Lindsay E

    2012-01-01

    Prior studies of Mesozoic biodiversity document a diversity peak for dinosaur species in the Campanian stage of the Late Cretaceous, yet have failed to provide explicit causal mechanisms. We provide evidence that a marked increase in North American dinosaur biodiversity can be attributed to dynamic orogenic episodes within the Western Interior Basin (WIB). Detailed fossil occurrences document an association between the shift from Sevier-style, latitudinally arrayed basins to smaller Laramide-style, longitudinally arrayed basins and a well substantiated decreased geographic range/increased taxonomic diversity of megaherbivorous dinosaur species. Dispersal-vicariance analysis demonstrates that the nearly identical biogeographic histories of the megaherbivorous dinosaur clades Ceratopsidae and Hadrosauridae are attributable to rapid diversification events within restricted basins and that isolation events are contemporaneous with known tectonic activity in the region. SymmeTREE analysis indicates that megaherbivorous dinosaur clades exhibited significant variation in diversification rates throughout the Late Cretaceous. Phylogenetic divergence estimates of fossil clades offer a new lower boundary on Laramide surficial deformation that precedes estimates based on sedimentological data alone.

  1. Sensitivity of South American tropical climate to Last Glacial Maximum boundary conditions: focus on teleconnections with tropics and extratropics (Invited)

    Science.gov (United States)

    Khodri, M.; Kageyama, M.; Roche, D. M.

    2009-12-01

    Proxy data over tropical latitudes for the Last Glacial Maximum (LGM) has been interpreted as a southward shift of the Inter Tropical Convergence Zone (ITCZ) and so far linked to a mechanism analogous to the modern day “meridional-mode” in the Atlantic Ocean. Here we have explored alternative mechanisms, related to the direct impact of the LGM global changes in the dry static stability on tropical moist deep convection. We have used a coupled ocean-atmosphere model capable of capturing the thermodynamical structure of the atmosphere and the tropical component of the Hadley and Walker circulations. In each experiment, we have applied either all the LGM forcings, or the individual contributions of greenhouse gases (GHG) concentrations, ice sheet topography and/or albedo to explore the hydrological response over tropical latitudes with a focus on South America. The dominant forcing for the LGM tropical temperature and precipitation changes is found to be due to the reduced GHG, through the direct effect of reduced radiative heating (Clausius-Clapeyron relationship). The LGM GHG is also responsible for increased extra-tropical static stability which strengthens the Hadley Cell. Stronger subsidence over northern tropics then produces an amplification of the northern tropics drying initially due to the direct cooling effect. The land ice sheet is also able to promote the Hadley cell feedback mostly via the topographic effect on the extra-tropical dry static stability and on the position of the subtropical jets. Our results therefore suggest that the communication between the extratropics and the tropics is tighter during LGM and does not necessarily rely on the “meridional-mode” mechanism. The Hadley cell response is constrained by the requirement that diabatic heating in the tropics balances cooling in subtropics. We show that such extratropics-tropics dependence is stronger at the LGM because of the stronger perturbation of northern extra tropical thermal and

  2. Nonlinear interactions between the Amazon River basin and the Tropical North Atlantic at interannual timescales

    Science.gov (United States)

    Builes-Jaramillo, Alejandro; Marwan, Norbert; Poveda, Germán; Kurths, Jürgen

    2018-04-01

    We study the physical processes involved in the potential influence of Amazon (AM) hydroclimatology over the Tropical North Atlantic (TNA) Sea Surface Temperatures (SST) at interannual timescales, by analyzing time series of the precipitation index (P-E) over AM, as well as the surface atmospheric pressure gradient between both regions, and TNA SSTs. We use a recurrence joint probability based analysis that accounts for the lagged nonlinear dependency between time series, which also allows quantifying the statistical significance, based on a twin surrogates technique of the recurrence analysis. By means of such nonlinear dependence analysis we find that at interannual timescales AM hydrology influences future states of the TNA SSTs from 0 to 2 months later with a 90-95% statistical confidence. It also unveils the existence of two-way feedback mechanisms between the variables involved in the processes: (1) precipitation over AM leads the atmospheric pressure gradient between TNA and AM from 0 to 2 month lags, (2) the pressure gradient leads the trade zonal winds over the TNA from 0 to 3 months and from 7 to 12 months, (3) the zonal winds lead the SSTs from 0 to 3 months, and (4) the SSTs lead precipitation over AM by 1 month lag. The analyses were made for time series spanning from 1979 to 2008, and for extreme precipitation events in the AM during the years 1999, 2005, 2009 and 2010. We also evaluated the monthly mean conditions of the relevant variables during the extreme AM droughts of 1963, 1980, 1983, 1997, 1998, 2005, and 2010, and also during the floods of 1989, 1999, and 2009. Our results confirm that the Amazon River basin acts as a land surface-atmosphere bridge that links the Tropical Pacific and TNA SSTs at interannual timescales. The identified mutual interactions between TNA and AM are of paramount importance for a deeper understanding of AM hydroclimatology but also of a suite of oceanic and atmospheric phenomena over the TNA, including recently

  3. North American isoprene influence on intercontinental ozone pollution

    Directory of Open Access Journals (Sweden)

    A. M. Fiore

    2011-02-01

    Full Text Available Changing land-use and climate may alter emissions of biogenic isoprene, a key ozone (O3 precursor. Isoprene is also a precursor to peroxy acetyl nitrate (PAN and thus affects partitioning among oxidized nitrogen (NOy species, shifting the balance towards PAN, which more efficiently contributes to long-range transport relative to nitric acid (HNO3 which rapidly deposits. With a suite of sensitivity simulations in the MOZART-2 global tropospheric chemistry model, we gauge the relative importance of the intercontinental influence of a 20% increase in North American (NA isoprene and a 20% decrease in NA anthropogenic emissions (nitrogen oxides (NOx, non-methane volatile organic compounds (NMVOC and NOx + NMVOC + carbon monoxide + aerosols. The surface O3 response to NA isoprene emissions (ΔO3_ISOP in surface air over NA is about one third of the response to all NA anthropogenic emissions (ΔO3_ANTH; although with different signs. Over intercontinental distances, ΔO3_ISOP is relatively larger; in summer and fall, ΔO3_ISOP in surface air over Europe and North Africa (EU region is more than half of ΔO3_ANTH. Future increases in NA isoprene emissions could thus offset decreases in EU surface O3 resulting from controls on NA anthropogenic emissions. Over the EU region, ΔPAN_ISOP at 700 hPa is roughly the same magnitude as ΔPAN_ANTH (oppositely signed. Outside of the continental source region, the percentage changes in PAN are at least twice as large as for surface O3, implying that long-term PAN measurements at high altitude sites may help to detect O3 precursor emission changes. We find that neither the baseline level of isoprene emissions nor the fate of isoprene nitrates contributes to the large diversity in model estimates of the anthropogenic emission influence on intercontinental surface O

  4. Unraveling reticulate evolution in North American Dryopteris (Dryopteridaceae

    Directory of Open Access Journals (Sweden)

    Sessa Emily B

    2012-06-01

    Full Text Available Abstract Background The thirteen species of Dryopteris in North America have long been suspected of having undergone a complicated history of reticulate evolution via allopolyploid hybridization. Various explanations for the origins of the allopolyploid taxa have been suggested, and though most lines of evidence have supported the so-called “semicristata” hypothesis, contention over the group’s history has continued in several recent, conflicting studies. Results Sequence data from nine plastid and two nuclear markers were collected from 73 accessions representing 35 species of Dryopteris. Sequences from each of the allopolyploids are most closely related to their progenitor species as predicted by the “semicristata” hypothesis. Allotetraploid D. campyloptera appears to be derived from a hybrid between diploid D. expansa and D. intermedia; D. celsa, from diploid D. ludoviciana x D. goldiana; and D. carthusiana and D. cristata, from diploid “D. semicristata” x D. intermedia and D. ludoviciana, respectively. Allohexaploid D. clintoniana appears to be derived from D. cristata x D.goldiana. The earliest estimated dates of formation of the allopolyploids, based on divergence time analyses, were within the last 6 Ma. We found no evidence for recurrent formation of any of the allopolyploids. The sexual allopolyploid taxa are derived from crosses between parents that show intermediate levels of genetic divergence relative to all pairs of potential progenitors. In addition, the four allotetraploids are transgressive with respect to geographic range relative to one or both of their parents (their ranges extend beyond those of the parents, suggesting that ecological advantages in novel habitats or regions may promote long-term regional coexistence of the hybrid taxa with their progenitors. Conclusions This study provides the first thorough evaluation of the North American complex of woodferns using extensive sampling of taxa and genetic

  5. Patch-testing North American lip dermatitis patients: data from the North American Contact Dermatitis Group, 2001 to 2004.

    Science.gov (United States)

    Zug, Kathryn A; Kornik, Rachel; Belsito, Donald V; DeLeo, Vincent A; Fowler, Joseph F; Maibach, Howard I; Marks, James G; Mathias, C G Toby; Pratt, Melanie D; Rietschel, Robert L; Sasseville, Denis; Storrs, Frances J; Taylor, James S; Warshaw, Erin M

    2008-01-01

    The most common differential diagnoses for patients presenting with lip dermatitis or inflammation include atopic, allergic, and irritant contact dermatitis. Patch testing can be performed to identify the allergic contact conditions. To report North American Contact Dermatitis Group (NACDG) patch-test results of patients who presented for patch testing with only lip involvement from 2001 to 2004. Patient characteristics, allergen frequencies, relevance, final diagnoses, and relevant allergic sources not in the NACDG screening series were evaluated. The NACDG 2001-2004 database was used to select patients presenting with only lip involvement. Of 10,061 patients tested, 2% (n = 196) had lips as the sole involved site. Most (84.2%) were women. After patch testing, 38.3% (n = 75) were diagnosed with allergic contact cheilitis. Fragrance mix, Myroxilon pereirae, and nickel were the most common relevant allergens. Of 75 patients, 27 (36%) had relevant positive patch-test reactions to items not on the NACDG series; lipstick and cosmetics were the predominant sources. Patch testing is valuable in the evaluation and identification of contact allergy in patients referred for lip dermatitis. The use of supplementary allergens based on history and exposure is important in the identification of additional relevant allergens. Over a third of patients with contact allergy had other factors, such as irritant dermatitis, considered relevant to their condition.

  6. Technology assessment of multileaf collimation: a North American users survey

    International Nuclear Information System (INIS)

    Klein, Eric E.; Tepper, Joel; Sontag, Mark; Franklin, Michael; Ling, Clifton; Kubo, Dale

    1999-01-01

    Purpose: The American Association of Physicists in Medicine (AAPM) initiated an Assessment of Technology Subcommittee (ATS) to help the radiotherapy community evaluate emerging technologies. The ATS decided to first address multileaf collimation (MLC) by means of a North American users survey. The survey attempted to address issues such as MLC utility, efficacy, cost-effectiveness, and customer satisfaction. Methods and Materials: The survey was designed with 38 questions, with cross-tabulation set up to decipher a particular clinic's perception of MLC. The surveys were coded according to MLC types, which were narrowed to four: Elekta, Siemens, Varian 52-leaf, and Varian 80-leaf. A 40% return rate was desired. Results: A 44% (108 of 250) return was achieved. On an MLC machine, 76.5% of photon patients are being treated with MLC. The main reasons for not using MLC were stair stepping, field size limitation, and physician objection. The most common sites in which MLC is being used are lung, pelvis, and prostate. The least used sites are head and neck and mantle fields. Of the facilities, 31% claimed an increase in number of patients being treated since MLC was installed, and 44% claimed an increase in the number of fields. Though the staffing for block cutting has decreased, therapist staffing has not. However, 91% of the facilities claimed a decreased workload for the therapists, despite the increase in daily treated patients and fields. Of the facilities that justified MLC purchase for more daily patients, 63% are actually treating more patients. Only 26% of the facilities that justified an MLC purchase for intensity-modulated radiotherapy (IMRT) are currently using it for that purpose. The satisfaction rating (1 = low to 5 = high) for department groups averaged 4.0. Therapists ranked MLC as 4.6. Conclusions: Our survey shows that most users have successfully introduced MLC into the clinic as a block replacement. Most have found MLC to be cost-effective and

  7. 76 FR 1065 - Security Zone; 23rd Annual North American International Auto Show, Detroit River, Detroit, MI

    Science.gov (United States)

    2011-01-07

    ...-AA87 Security Zone; 23rd Annual North American International Auto Show, Detroit River, Detroit, MI... officials at the 23rd Annual North American International Auto Show (NAIAS) being held at Cobo Hall in... 23rd Annual North American International Auto Show (NAIAS) being held at Cobo Hall in downtown Detroit...

  8. 77 FR 76411 - Security Zone; 25th Annual North American International Auto Show, Detroit River, Detroit, MI

    Science.gov (United States)

    2012-12-28

    ...-AA87 Security Zone; 25th Annual North American International Auto Show, Detroit River, Detroit, MI..., visitors, and public officials at the 25th Annual North American International Auto Show (NAIAS), which is... Purpose The 25th Annual North American International Auto Show (NAIAS) will be held at Cobo Hall in...

  9. 77 FR 2453 - Security Zone; 24th Annual North American International Auto Show, Detroit River, Detroit, MI

    Science.gov (United States)

    2012-01-18

    ...-AA87 Security Zone; 24th Annual North American International Auto Show, Detroit River, Detroit, MI..., visitors, and public officials at the 24th Annual North American International Auto Show (NAIAS), which is... The 24th Annual North American International Auto Show (NAIAS) will be held at Cobo Hall in downtown...

  10. 77 FR 26252 - North American Free Trade Agreement, Article 1904 NAFTA Panel Reviews; First Request for Panel...

    Science.gov (United States)

    2012-05-03

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free Trade Agreement... the North American Free Trade Agreement. On April 25, 2012, an additional Request was filed on behalf... INFORMATION: Chapter 19 of the North American Free Trade Agreement (``Agreement'') established a mechanism to...

  11. 76 FR 10005 - North American Free Trade Agreement, Article 1904 NAFTA Panel Reviews; Request for Panel Review

    Science.gov (United States)

    2011-02-23

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free Trade Agreement... Secretariat pursuant to Article 1904 of the North American Free Trade Agreement. Panel Review was requested of...-5438. SUPPLEMENTARY INFORMATION: Chapter 19 of the North American Free Trade Agreement (``Agreement...

  12. 48 CFR 27.204-1 - Use of patented technology under the North American Free Trade Agreement.

    Science.gov (United States)

    2010-10-01

    ... under the North American Free Trade Agreement. 27.204-1 Section 27.204-1 Federal Acquisition Regulations... Patents and Copyrights 27.204-1 Use of patented technology under the North American Free Trade Agreement... the patent holder is from a country that is a party to the North American Free Trade Agreement (NAFTA...

  13. 77 FR 66441 - North American Free Trade Agreement, Article 1904 NAFTA Panel Reviews; First Request for Panel...

    Science.gov (United States)

    2012-11-05

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free Trade Agreement... North American Free Trade Agreement. Panel Review was requested of the U.S. Department of Commerce's..., (202) 482-5438. SUPPLEMENTARY INFORMATION: Chapter 19 of the North American Free Trade Agreement...

  14. Challenges facing the North American iron ore industry

    Science.gov (United States)

    Jorgenson, J.D.

    2005-01-01

    During the 20th century, the iron ore mining industries of Canada and the United States passed through several periods of transformation. The beginning of the 21st century has seen yet another period of transformation, with the economic failure of a number of steel companies, the acquisition of their facilities by more viable steelmakers, and the consolidation of control within the North American iron ore industry. Changes in Canadian and United States iron ore production and the market control structure involved are analysed. The consolidation of ownership, formation of foreign joint ventures within Nordi America, planned divestitures of upstream activities by steelmakers, and industry changes made to ensure availability of feedstocks will be reviewed. The ttaditional isolation of the Canadian and United States iron ore operations and their strong linkage to downstream steel production will be discussed in the context of a changing global economy. Management-labour conflicts that have taken place and agreements made during 2000 through 2004 will be discussed in the context of the economic environment leading up to these agreements. Cooperative agreements between competing Canadian and United States companies to resolve client needs in processing and blending will be examined. A joint industry-government project designed to use new technology to produce direct reduced iron nuggets of 96 - 98 per cent iron content using non-coking coals will also be assessed. Changes in iron ore transportation methods, ownership and infrastructure will be reviewed for both rail and inland waterway transport between Canadian and United States companies. A brief analysis of social and environmental issues relating to sustainable development of the Canadian-United States iron ore industry will be included.

  15. Predicting vulnerabilities of North American shorebirds to climate change.

    Directory of Open Access Journals (Sweden)

    Hector Galbraith

    Full Text Available Despite an increase in conservation efforts for shorebirds, there are widespread declines of many species of North American shorebirds. We wanted to know whether these declines would be exacerbated by climate change, and whether relatively secure species might become at-risk species. Virtually all of the shorebird species breeding in the USA and Canada are migratory, which means climate change could affect extinction risk via changes on the breeding, wintering, and/or migratory refueling grounds, and that ecological synchronicities could be disrupted at multiple sites. To predict the effects of climate change on shorebird extinction risks, we created a categorical risk model complementary to that used by Partners-in-Flight and the U.S. Shorebird Conservation Plan. The model is based on anticipated changes in breeding, migration, and wintering habitat, degree of dependence on ecological synchronicities, migration distance, and degree of specialization on breeding, migration, or wintering habitat. We evaluated 49 species, and for 3 species we evaluated 2 distinct populations each, and found that 47 (90% taxa are predicted to experience an increase in risk of extinction. No species was reclassified into a lower-risk category, although 6 species had at least one risk factor decrease in association with climate change. The number of species that changed risk categories in our assessment is sensitive to how much of an effect of climate change is required to cause the shift, but even at its least sensitive, 20 species were at the highest risk category for extinction. Based on our results it appears that shorebirds are likely to be highly vulnerable to climate change. Finally, we discuss both how our approach can be integrated with existing risk assessments and potential future directions for predicting change in extinction risk due to climate change.

  16. Prosopis pod production: comparison of North American, South American, Hawaiin, and African germplasm in young plantations

    Energy Technology Data Exchange (ETDEWEB)

    Felker, P.; Clark, P.R.; Osborn, J.F.; Cannell, G.H.

    Prosopis pod production was compared in 3 field trials in southern California, i.e., a typical orchard planting, an irrigation trial, and a heat/drought stress trial. Thirteen species representing North American, South American, Hawaiian, and African germplasm were evaluated. Hawaiian and African accessions were eliminated from the irrigation trial by a minus 5/sup 0/C temperature. The most productive pod producers were P. velutina accessions from southern Arizona. In the fifth season, 5 trees of the most productive accession, i.e., P. velutina 32 had a mean pod production of 7.2 kg/tree with a range of 3.2-12.2 kg/tree. P. chilensis and P. alba trees of the same age were much larger but had less pod production. Trees in the driest irrigation treatment had the greatest pod production. Pod production estimates of 3000-4000 kg/ha were obtained in the dry irrigation treatment by P. velutina 20 which received 370 mm rainfall in the year preceding harvest. 32 references, 1 figure, 6 tables.

  17. Asymmetric response of tropical cyclone activity to global warming over the North Atlantic and western North Pacific from CMIP5 model projections.

    Science.gov (United States)

    Park, Doo-Sun R; Ho, Chang-Hoi; Chan, Johnny C L; Ha, Kyung-Ja; Kim, Hyeong-Seog; Kim, Jinwon; Kim, Joo-Hong

    2017-01-30

    Recent improvements in the theoretical understanding of the relationship between tropical cyclones (TCs) and their large-scale environments have resulted in significant improvements in the skill for forecasting TC activity at daily and seasonal time-scales. However, future changes in TC activity under a warmer climate remain uncertain, particularly in terms of TC genesis locations and subsequent pathways. Applying a track-pattern-based statistical model to 22 Coupled Model Intercomparison Project Phase 5 (CMIP5) model runs for the historical period and the future period corresponding to the Representative Concentration Pathway 8.5 emissions scenarios, this study shows that in future climate conditions, TC passage frequency will decrease over the North Atlantic, particularly in the Gulf of Mexico, but will increase over the western North Pacific, especially that hits Korea and Japan. Unlike previous studies based on fine-resolution models, an ensemble mean of CMIP5 models projects an increase in TC activity in the western North Pacific, which is owing to enhanced subtropical deep convection and favorable dynamic conditions therein in conjunction with the expansion of the tropics and vice versa for the North Atlantic. Our results suggest that North America will experience less TC landfalls, while northeast Asia will experience more TCs than in the present-day climate.

  18. Assessing the role of North Atlantic freshwater forcing in millennial scale climate variability: a tropical Atlantic perspective

    Energy Technology Data Exchange (ETDEWEB)

    Dahl, Kristina A [Massachusetts Institute of Technology/Woods Hole Oceanographic Institution Joint Program, Woods Hole, MA (United States); Broccoli, Anthony J [Rutgers University, Department of Environmental Sciences, New Brunswick, NJ (United States); Stouffer, Ronald J [Geophysical Fluid Dynamics Laboratory, Princeton, NJ (United States)

    2005-03-01

    This study analyzes a three-member ensemble of experiments, in which 0.1 Sv of freshwater was applied to the North Atlantic for 100 years in order to address the potential for large freshwater inputs in the North Atlantic to drive abrupt climate change. The model used is the GFDL R30 coupled ocean-atmosphere general circulation model. We focus in particular on the effects of this forcing on the tropical Atlantic region, which has been studied extensively by paleoclimatologists. In response to the freshwater forcing, North Atlantic meridional overturning circulation is reduced to roughly 40% by the end of the 100 year freshwater pulse. Consequently, the North Atlantic region cools by up to 8 C. The extreme cooling of the North Atlantic increases the pole-to-equator temperature gradient and requires more heat be provided to the high latitude Atlantic from the tropical Atlantic. To accommodate the increased heat requirement, the ITCZ shifts southward to allow for greater heat transport across the equator. Accompanying this southward ITCZ shift, the Northeast trade winds strengthen and precipitation patterns throughout the tropical Atlantic are altered. Specifically, precipitation in Northeast Brazil increases, and precipitation in Africa decreases slightly. In addition, we find that surface air temperatures warm over the tropical Atlantic and over Africa, but cool over northern South America. Sea-surface temperatures in the tropical Atlantic warm slightly with larger warm anomalies developing in the thermocline. These responses are robust for each member of the ensemble, and have now been identified by a number of freshwater forcing studies using coupled OAGCMs. The model responses to freshwater forcing are generally smaller in magnitude, but have the same direction, as paleoclimate data from the Younger Dryas suggest. In certain cases, however, the model responses and the paleoclimate data directly contradict one another. Discrepancies between the model simulations

  19. Climate Prediction Center (CPC) Monthly Pacific North American Teleconnection Pattern Index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly tabulated index of the Pacific/ North American teleconnection pattern. The data spans the period 1950 to present. The index is derived from a rotated...

  20. Endangered Species and North American Waterfowl Management Plan Joint Venture Areas

    National Research Council Canada - National Science Library

    Allred, Karla

    1996-01-01

    ...) Endangered Species Recovery Plans that meet the recovery plan requirements; and the percent of Corps acreage included within North American Waterfowl Management Joint Venture Implementation Plans where proposed work has been accomplished...

  1. 76 FR 23286 - North American Free Trade Agreement (NAFTA), Article 1904 Binational Panel Reviews: Notice of...

    Science.gov (United States)

    2011-04-26

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free Trade Agreement... Secretariat, United States Section, International Trade Administration, Department of Commerce. ACTION: Notice... International Trade Commission, in the matter of Light-Walled Rectangular Pipe and Tube from Mexico, Secretariat...

  2. Climate change effects on North American inland fish populations and assemblages

    Science.gov (United States)

    Lynch, Abigail J.; Myers, Bonnie; Chu, Cindy; Eby, Lisa A.; Falke, Jeffrey A.; Kovach, Ryan P.; Krabbenhoft, Trevor J.; Kwak, Thomas J.; Lyons, John; Paukert, Craig P.; Whitney, James E.

    2016-01-01

    Climate is a critical driver of many fish populations, assemblages, and aquatic communities. However, direct observational studies of climate change impacts on North American inland fishes are rare. In this synthesis, we (1) summarize climate trends that may influence North American inland fish populations and assemblages, (2) compile 31 peer-reviewed studies of documented climate change effects on North American inland fish populations and assemblages, and (3) highlight four case studies representing a variety of observed responses ranging from warmwater systems in the southwestern and southeastern United States to coldwater systems along the Pacific Coast and Canadian Shield. We conclude by identifying key data gaps and research needs to inform adaptive, ecosystem-based approaches to managing North American inland fishes and fisheries in a changing climate.

  3. 78 FR 7773 - Notice of Commissioner and Staff Attendance at North American Electric Reliability Corporation...

    Science.gov (United States)

    2013-02-04

    ... Board of Trustees Meetings, Board of Trustees Compliance Committee, Corporate Governance and Human Resources Committee, and Standards Oversight and Technology Committee Meetings. Hotel del Coronado, 1500... Association, Inc. v. Western Electric Coordinating Council and North American Electric Reliability Corporation...

  4. Cavitary mass lesion and recurrent pneumothoraces due to Paragonimus kellicotti infection: North American paragonimiasis.

    Science.gov (United States)

    Castilla, Elias A; Jessen, Robert; Sheck, David N; Procop, Gary W

    2003-08-01

    North American paragonimiasis is well described in omnivorous and carnivorous animals on this continent. Humans are rarely infected, largely because of dietary customs, but are at risk for infection if raw or undercooked crayfish are consumed. We describe a patient with a pleuropulmonary infection due to Paragonimus kellicotti that presented as recurrent pneumothoraces and a cavitary lesion. This is the first case of North American paragonimiasis in which the diagnosis was based on the morphology of the eggs present in histologic sections.

  5. The North American coach tourist to Ireland: a factor analysis approach

    OpenAIRE

    Ryan, Marie; Deegan, Jim

    2010-01-01

    The objective of this paper is to identify the most significant travel behaviours and characteristics of North American coach tourists visiting Ireland. The data, identifying travel behaviours and characteristics, such as travel constraints, motivation, activities, accommodation attributes, life focus and personality traits was elucidated from questionnaires (n = 741) distributed to North American coach tourists that visited Ireland between June 2007 and March 2008. Factor analysis, which is ...

  6. Molecular clouds in the North American and Pelican Nebulae: structures

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shaobo; Xu, Ye; Yang, Ji, E-mail: shbzhang@pmo.ac.cn [Purple Mountain Observatory, and Key Laboratory for Radio Astronomy, Chinese Academy of Sciences, Nanjing 210008 (China)

    2014-03-01

    We present observations of a 4.25 deg{sup 2} area toward the North American and Pelican Nebulae in the J = 1-0 transitions of {sup 12}CO, {sup 13}CO, and C{sup 18}O. Three molecules show different emission areas with their own distinct structures. These different density tracers reveal several dense clouds with a surface density of over 500 M {sub ☉} pc{sup –2} and a mean H{sub 2} column density of 5.8, 3.4, and 11.9 × 10{sup 21} cm{sup –2} for {sup 12}CO, {sup 13}CO, and C{sup 18}O, respectively. We obtain a total mass of 5.4 × 10{sup 4} M {sub ☉} ({sup 12}CO), 2.0 × 10{sup 4} M {sub ☉} ({sup 13}CO), and 6.1 × 10{sup 3} M {sub ☉} (C{sup 18}O) in the complex. The distribution of excitation temperature shows two phases of gas: cold gas (∼10 K) spreads across the whole cloud; warm gas (>20 K) outlines the edge of the cloud heated by the W80 H II region. The kinetic structure of the cloud indicates an expanding shell surrounding the ionized gas produced by the H II region. There are six discernible regions in the cloud: the Gulf of Mexico, Caribbean Islands and Sea, and Pelican's Beak, Hat, and Neck. The areas of {sup 13}CO emission range within 2-10 pc{sup 2} with mass of (1-5) × 10{sup 3} M {sub ☉} and line width of a few km s{sup –1}. The different line properties and signs of star-forming activity indicate they are in different evolutionary stages. Four filamentary structures with complicated velocity features are detected along the dark lane in LDN 935. Furthermore, a total of 611 molecular clumps within the {sup 13}CO tracing cloud are identified using the ClumpFind algorithm. The properties of the clumps suggest that most of the clumps are gravitationally bound and at an early stage of evolution with cold and dense molecular gas.

  7. Mobile Extracorporeal Membrane Oxygenation Teams: The North American Versus the European Experience.

    Science.gov (United States)

    Nwozuzu, Adambeke; Fontes, Manuel L; Schonberger, Robert B

    2016-12-01

    To evaluate differences in the inclusion of anesthesiologists in mobile extracorporeal membrane oxygenation (ECMO) teams between North American and European centers. A retrospective review of North American versus European mobile ECMO teams. The search terms used to identify relevant articles were the following: "extracorporeal membrane transport," "mobile ECMO," and "interhospital transport." MEDLINE review of articles. None. None. Between 1986 and 2015, 25 articles were published that reported the personnel makeup of mobile ECMO teams in North America and Europe: 6 from North American centers and 19 from European centers. The included articles reported a total of 1,329 cases: 389 (29%) adult-only cohorts and 940 (71%) mixed-age cohorts. Among North American studies, 0 of 6 (0%) reported the presence of an anesthesiologist on the mobile ECMO team in contrast to European studies, in which 10 of 19 (53%) reported the inclusion of an anesthesiologist (Fisher exact p for difference = 0.05). In terms of number of cases, this discrepancy translated to 543 total cases in North America (all without an anesthesiologist) and 499 cases in Europe (37%) including an anesthesiologist on the team (Fisher exact p for difference<0.001). This study demonstrated significant geographic discrepancies in the inclusion of anesthesiologists on mobile ECMO teams, with European centers more likely to incorporate an anesthesiologist into the mobile ECMO process compared with North American centers. Copyright © 2016. Published by Elsevier Inc.

  8. Phylogeography, postglacial gene flow, and population history of North American northern goshawks (Accipiter gentilis)

    Science.gov (United States)

    Shelley Bayard de Volo; Richard T. Reynolds; Sarah A. Sonsthagen; Sandra L. Talbot; Michael F. Antolin

    2013-01-01

    Climate cycling during the Quaternary played a critical role in the diversification of avian lineages in North America, greatly influencing the genetic characteristics of contemporary populations. To test the hypothesis that North American Northern Goshawks (Accipiter gentilis) were historically isolated within multiple Late Pleistocene refugia, we assessed diversity...

  9. Model comparisons for estimating carbon emissions from North American wildland fire

    Science.gov (United States)

    Nancy H.F. French; William J. de Groot; Liza K. Jenkins; Brendan M. Rogers; Ernesto Alvarado; Brian Amiro; Bernardus De Jong; Scott Goetz; Elizabeth Hoy; Edward Hyer; Robert Keane; B.E. Law; Donald McKenzie; Steven G. McNulty; Roger Ottmar; Diego R. Perez-Salicrup; James Randerson; Kevin M. Robertson; Merritt. Turetsky

    2011-01-01

    Research activities focused on estimating the direct emissions of carbon from wildland fires across North America are reviewed as part of the North American Carbon Program disturbance synthesis. A comparison of methods to estimate the loss of carbon from the terrestrial biosphere to the atmosphere from wildland fires is presented. Published studies on emissions from...

  10. Consequences of climate change for biotic disturbances in North American forests

    Science.gov (United States)

    Aaron S. Weed; Matthew P. Ayres; Jeffrey A. Hicke

    2013-01-01

    About one-third of North America is forested. These forests are of incalculable value to human society in terms of harvested resources and ecosystem services and are sensitive to disturbance regimes. Epidemics of forest insects and diseases are the dominant sources of disturbance to North American forests. Here we review current understanding of climatic effects...

  11. Changes in size and trends of North American sea duck populations associated with North Pacific oceanic regime shifts

    Science.gov (United States)

    Flint, Paul L.

    2013-01-01

    Broad-scale multi-species declines in populations of North American sea ducks for unknown reasons is cause for management concern. Oceanic regime shifts have been associated with rapid changes in ecosystem structure of the North Pacific and Bering Sea. However, relatively little is known about potential effects of these changes in oceanic conditions on marine bird populations at broad scales. I examined changes in North American breeding populations of sea ducks from 1957 to 2011 in relation to potential oceanic regime shifts in the North Pacific in 1977, 1989, and 1998. There was strong support for population-level effects of regime shifts in 1977 and 1989, but little support for an effect of the 1998 shift. The continental-level effects of these regime shifts differed across species groups and time. Based on patterns of sea duck population dynamics associated with regime shifts, it is unclear if the mechanism of change relates to survival or reproduction. Results of this analysis support the hypothesis that population size and trends of North American sea ducks are strongly influenced by oceanic conditions. The perceived population declines appear to have halted >20 years ago, and populations have been relatively stable or increasing since that time. Given these results, we should reasonably expect dramatic changes in sea duck population status and trends with future oceanic regime shifts.

  12. Large scale surveys suggest limited mercury availability in tropical north Queensland (Australia)

    International Nuclear Information System (INIS)

    Jardine, Timothy D.; Halliday, Ian A.; Howley, Christina; Sinnamon, Vivian; Bunn, Stuart E.

    2012-01-01

    Little is known about the threat of mercury (Hg) to consumers in food webs of Australia's wet–dry tropics. This is despite high concentrations in similar biomes elsewhere and a recent history of gold mining that could lead to a high degree of exposure for biota. We analysed Hg in water, sediments, invertebrates and fishes in rivers and estuaries of north Queensland, Australia to determine its availability and biomagnification in food webs. Concentrations in water and sediments were low relative to other regions of Hg concern, with only four of 138 water samples and five of 60 sediment samples above detection limits of 0.1 μg L −1 and 0.1 μg g −1 , respectively. Concentrations of Hg in fishes and invertebrates from riverine and wetland food webs were well below international consumption guidelines, including those in piscivorous fishes, likely due to low baseline concentrations and limited rates of biomagnification (average slope of log Hg vs. δ 15 N = 0.08). A large fish species of recreational, commercial, and cultural importance (the barramundi, Lates calcarifer), had low concentrations that were below consumption guidelines. Observed variation in Hg concentrations in this species was primarily explained by age and foraging location (floodplain vs. coastal), with floodplain feeders having higher Hg concentrations than those foraging at sea. These analyses suggest that there is a limited threat of Hg exposure for fish-eating consumers in this region. - Highlights: ► Hg concentrations in freshwaters and sediments of north Queensland were low. ► Biomagnification of Hg through riverine food webs was limited. ► Barramundi, a predatory fish, had low concentrations meaning low risk for consumers. ► Floodplain-feeding barramundi had higher Hg concentrations than coastal feeders.

  13. Thirty-seventh supplement to the American Ornithologists' Union Check-list of North American birds

    Science.gov (United States)

    Monroe, Burt L.; Banks, Richard C.; Fitzpatrick, John W.; Howell, Thomas R.; Johnson, Ned K.; Ouellet, Henri; Remsen, J.V.; Storer, Robert W.

    1989-01-01

    This third supplement subsequent to the 6th edition (1983) of the A.O.U. "Check-list of North American Birds" consists of changes adopted by the Committee on Classification and Nomenclature as of 1 March 1989. The changes fall into nine categories: (1) six species are added to the main list (Pterodroma longirostris, Larus crassirostris, Streptopelia decaocto, Cocccyzus julieni, Chrysolampis mosquitus, Emberiza aureola) because of new distributional information; (2) five species (Ara cubensis, Chlorostilbon bracei, Empidonax occidentalis, Polioptila californica, Pipilo crissalis) are added to the main list because of the splitting of species already on the list; (3) one name (Anthus rubescens) is changed because of the splitting of a species from outside the Checklist area; (4) two names (Morus bassanus, Nyctanassa violacea) is removed from the main list to Appendix B because of re-evaluation of Northern Hemisphere records; (6) three species (Pterodrama rostrata, P. alba, P. solandri) are moved from Appendix A to Appendix B, and one (P. defilippiana) is added to Appendix B because of questionable sight records; (7)A.O.U. numbers are added to three species (Ciccaba virgata, Myiopagis viridicata, Molothrus bonariensis) on the basis on new distributional records or supporting data; (8) several corrections in spelling or citations are made; and (9) English names are changed for twelve species to accommodate worldwide usage of these names. No new distributional information is included except as indicated above (i.e. minor changes of distribution are not noted). These actions bring the number of species recognized as occurring in North America (main list) to 1,945.

  14. Do the Atlantic climate modes impact the ventilation of the eastern tropical North Atlantic oxygen minimum zones?

    Science.gov (United States)

    Burmeister, Kristin; Lübbecke, Joke F.

    2017-04-01

    Oxygen minimum zones (OMZs) exist in the upwelling regions of the eastern tropical Atlantic and Pacific at intermediate depth. They are a consequence of high biological productivity in combination with weak ventilation. The flow fields in the tropical Atlantic is characterized by Latitudinally Alternating Zonal Jets (LAZJs) with a large vertical scale. It has been suggested that LAZJs play an important role for the ventilation of the OMZ as eastward currents advect oxygen-rich waters from the western boundary towards the OMZ. In the Eastern Tropical North Atlantic (ETNA), the eastward flowing North Equatorial Undercurrent and North Equatorial Countercurrent (NECC) provide the main oxygen supply into the OMZ. Variability in the strength and location of the LAZJs is associated with oxygen variability in the ETNA OMZ. We here want to address the question whether the variability in the zonal current field can be partly attributed to the large-scale climate modes of the tropical Atlantic, namely the Atlantic zonal and meridional mode. An influence of these modes on the NECC has been found in previous studies. For the analysis we are using the output of a global ocean circulation model, in which a 1/10° nest covering the tropical Atlantic is embedded into a global 1/2° model, as well as reanalysis products and satellite data. The zonal current field and oxygen distribution from the high resolution model is compared to observational data. The location and intensity of the current bands during positive and negative phases of the Atlantic climate modes are compared by focusing on individual events and via composite analysis. Based on the results, the potential impact of the Atlantic climate modes on the ventilation of the ETNA OMZ is discussed.

  15. North American Rocky Mountain Hydroclimate: Holocene patterns and variability at multi-decadal to millennial time scales

    Science.gov (United States)

    Finney, B.; Anderson, L.; Berkelhammer, M. B.; Barron, J. A.; Steinman, B. A.; Abbott, M. B.

    2015-12-01

    A network of western North American lake sediment isotope records (calcium carbonate-δ18O) developed during the past decade provides substantial evidence of Pacific ocean-atmosphere forcing of precipitation variability during the Holocene. We present an overview of the eighteen lake carbonate-δ18O records located in the North American Rocky Mountains with a new compilation of modern lake water isotope measurements to characterize their sensitivity to variations in precipitation-δ18O and fractionation effects by evaporation. Comparative analysis of the carbonate-δ18O records that reflect precipitation isotope (δ18O) values (i.e., precipitation "isometers") indicates a sequence of time-varying in-phase and antiphase patterns between northern and southern regions during the Holocene that provide evidence for a highly non-stationary influence of Pacific ocean-atmosphere processes on the hydroclimate of western North America. We identify a prominent precipitation-δ18O dipole, which was sustained for ~2000 years between ~3.5 and 1.5 ka. The dipole contrasts with divergent earlier Holocene patterns and appears to indicate the onset of linkages between northern and tropical Pacific ocean-atmosphere dynamics as we know them today. These observations are informed by previous research on North Pacific precipitation-δ18O. Further investigation of short (observational) and long (Holocene) time scale patterns are needed to improve our understanding of the processes that 1) drive regional precipitation-δ18O responses to Pacific Ocean-atmosphere variability, and 2) cause varying internal ocean-atmosphere responses to external climate forcing.

  16. Biological nitrogen fixation in the oxygen-minimum region of the eastern tropical North Pacific ocean.

    Science.gov (United States)

    Jayakumar, Amal; Chang, Bonnie X; Widner, Brittany; Bernhardt, Peter; Mulholland, Margaret R; Ward, Bess B

    2017-10-01

    Biological nitrogen fixation (BNF) was investigated above and within the oxygen-depleted waters of the oxygen-minimum zone of the Eastern Tropical North Pacific Ocean. BNF rates were estimated using an isotope tracer method that overcame the uncertainty of the conventional bubble method by directly measuring the tracer enrichment during the incubations. Highest rates of BNF (~4 nM day -1 ) occurred in coastal surface waters and lowest detectable rates (~0.2 nM day -1 ) were found in the anoxic region of offshore stations. BNF was not detectable in most samples from oxygen-depleted waters. The composition of the N 2 -fixing assemblage was investigated by sequencing of nifH genes. The diazotrophic assemblage in surface waters contained mainly Proteobacterial sequences (Cluster I nifH), while both Proteobacterial sequences and sequences with high identities to those of anaerobic microbes characterized as Clusters III and IV type nifH sequences were found in the anoxic waters. Our results indicate modest input of N through BNF in oxygen-depleted zones mainly due to the activity of proteobacterial diazotrophs.

  17. Latitudinal Change of Tropical Cyclone Maximum Intensity in the Western North Pacific

    Directory of Open Access Journals (Sweden)

    Jae-Won Choi

    2016-01-01

    Full Text Available This study obtained the latitude where tropical cyclones (TCs show maximum intensity and applied statistical change-point analysis on the time series data of the average annual values. The analysis results found that the latitude of the TC maximum intensity increased from 1999. To investigate the reason behind this phenomenon, the difference of the average latitude between 1999 and 2013 and the average between 1977 and 1998 was analyzed. In a difference of 500 hPa streamline between the two periods, anomalous anticyclonic circulations were strong in 30°–50°N, while anomalous monsoon trough was located in the north of South China Sea. This anomalous monsoon trough was extended eastward to 145°E. Middle-latitude region in East Asia is affected by the anomalous southeasterlies due to these anomalous anticyclonic circulations and anomalous monsoon trough. These anomalous southeasterlies play a role of anomalous steering flows that make the TCs heading toward region in East Asia middle latitude. As a result, TCs during 1999–2013 had higher latitude of the maximum intensity compared to the TCs during 1977–1998.

  18. Control of tropical theileriosis (Theileria annulata infection in cattle in North Africa

    Directory of Open Access Journals (Sweden)

    Mohamed Gharbi

    2015-07-01

    Full Text Available Tropical theileriosis (Theileria annulata infection is a protozoan disease of cattle transmitted by Hyalomma ticks. This parasite is causing high losses in several countries in South Europe, North Africa and Asia. Indeed, both symptomatic and subclinical forms are present in infected animals causing live weight decrease, milk yield decrease, abortions and in some cases death. Due to its high medical and financial impact, the control of this disease is of paramount importance. It can be implemented through five control measures: (i treatment of infected animals with theilericidal drugs and other symptomatic treatments (this option is used for the treatment of animals and is insufficient to eradicate the parasite, (ii use of acaricides in animals which contain several side effects for humans, animals and the environment, (iii roughcasting and smoothing of the outer and inner surfaces of the cattle buildings for endophilic tick species (this control option is expensive but leads to the eradication of the parasite from the farm, (iv vaccination against ticks, a control option used with success against Rhipicephalus (Boophilus species but not still available for Hyalomma ticks and (v vaccination against the parasite with live attenuated vaccines. These control options were presented in the paper and their advantages and limits were discussed. The implementation of one (or more of these control options should take into account other considerations (social, political, etc.; they sometimes cause the failure of the control action.

  19. Interdecadal Change of Tropical Cyclone Genesis Controlling Parameter in Western North Pacific

    Science.gov (United States)

    Li, T.

    2017-12-01

    The main environmental parameter controlling tropical cyclone (TC) genesis in the western North Pacific (WNP) changed in different interdecadal periods. The interannual variability of TC genesis frequency was primarily control by specific humidity in 1950-1976, sea surface temperature (SST) in 1977-1998, and vorticity in 1999-2014. A further diagnosis shows that the change of environmental specific humidity during 1950-1976 was attributed to anomalous advection of mean moisture during ENSO developing summer. The SST change during 1977-1998 was associated with circulation change during ENSO decaying summer. The change of environment vorticity was primarily related to CP-type El Niño during 1999-2014. The ultimate cause of the controlling parameter change is attributed to the change of ENSO behavior. Compared to the first period, a stronger EP-type ENSO variability in the second period leads to a stronger circulation/SST response during ENSO decaying phase. The occurrence of more frequent CP type El Niño in the third period was responsible for greater vorticity controlling in the WNP.

  20. The roles of static stability and tropical-extratropical interactions in the summer interannual variability of the North Atlantic sector

    Science.gov (United States)

    Mbengue, Cheikh Oumar; Woollings, Tim; Dacre, Helen F.; Hodges, Kevin I.

    2018-04-01

    Summer seasonal forecast skill in the North Atlantic sector is lower than winter skill. To identify potential controls on predictability, the sensitivity of North Atlantic baroclinicity to atmospheric drivers is quantified. Using ERA-INTERIM reanalysis data, North Atlantic storm-track baroclinicity is shown to be less sensitive to meridional temperature-gradient variability in summer. Static stability shapes the sector's interannual variability by modulating the sensitivity of baroclinicity to variations in meridional temperature gradients and tropopause height and by modifying the baroclinicity itself. High static stability anomalies at upper levels result in more zonal extratropical cyclone tracks and higher eddy kinetic energy over the British Isles in the summertime. These static stability anomalies are not strongly related to the summer NAO; but they are correlated with the suppression of convection over the tropical Atlantic and with a poleward-shifted subtropical jet. These results suggest a non-local driver of North Atlantic variability. Furthermore, they imply that improved representations of convection over the south-eastern part of North America and the tropical Atlantic might improve summer seasonal forecast skill.

  1. North American Electric Reliability Council (NERC) Reliability Coordinators

    Data.gov (United States)

    Department of Homeland Security — ERC is an international regulatory authority that works to improve the reliability of the bulk power system in North America. NERC works with many different regional...

  2. NCEP North American Regional Reanalysis (NARR), for 1979 to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The North America Regional Reanalysis (NARR) Project is a reanalysis of historical observations using a 32-km version of the National Centers for Environmental...

  3. Introduction to the Population Ecology of North American Caribou

    Directory of Open Access Journals (Sweden)

    Dale R. Seip

    1996-01-01

    Full Text Available Bergerud has discussed how major differences in caribou density across North America appear to be related to the impact of wolf (Canis lupus predation, and the strategies used by caribou to avoid wolves. Caribou living in areas without wolves usually occur at high densities and are regulated by competition for food. In this session, we asked the presenters to discuss the population ecology of different caribou herds in North America and to evaluate if they fit the general model.

  4. Historical North Atlantic Tropical Cyclone Tracks 1851-2005, Geographic NAD83, NOAA (2006) [atlantic_hurricane_tracks_1851_2005_NOAA_2006

    Data.gov (United States)

    Louisiana Geographic Information Center — This Historical North Atlantic Tropical Cyclone Tracks file contains the 6-hourly (0000, 0600, 1200, 1800 UTC) center locations and intensities for all subtropical...

  5. Unravelling the Natural and Anthropogenic Drivers of North Atlantic Tropical Cyclone Track Position since the Little Ice Age

    Science.gov (United States)

    Baldini, L. M.; Baldini, J. U. L.; McElwaine, J.; Frappier, A. B.; Asmerom, Y.; Liu, K. B.; Prufer, K. M.; Ridley, H.; Polyak, V. J.; Kennett, D. J.; Macpherson, C.; Aquino, V. V.; Awe, J.; Breitenbach, S. F. M.

    2017-12-01

    In the last decade, stalagmites have been recognised as valuable archives of past hurricane activity. The characteristically low δ18O rainfall of tropical cyclones (TCs, including both hurricanes and tropical storms) is particularly well-preserved in fast-growing tropical speleothems. Here we present a new multi-proxy approach used to extract the western Caribbean TC signal from background wet season rainfall that, at our site in southern Belize, is driven by seasonal migration of the Intertropical Convergence Zone (ITCZ). The result is an annual 450-year record of western Caribbean TC activity that, when compared to documentary and statistical model-based reconstructions of North Atlantic TC activity, reveals a northward migration of dominant TC track since the height of Little Ice Age cooling. Importantly, the record reveals a reversal in the TC track position-North Atlantic sea surface temperature relationship between the pre-Industrial and Industrial Eras. During the pre-Industrial interval, TC track position migrated with the ITCZ toward the warmer hemisphere. Conversely, anthropogenic greenhouse gas and aerosol emissions during the Industrial Era have decoupled TC track position from the ITCZ through expansion of the Hadley Cell. This research suggests that under future greenhouse gas and aerosol emissions scenarios, the dominant TC track is likely to remain to the north. Combined with greenhouse gas-induced rising sea surface temperatures, the risk to the NE US population and financial centres is likely to increase in the future.

  6. Language Learning for the 21st Century: Challenges for the North American Free Trade Agreement.

    Science.gov (United States)

    Tucker, G. Richard

    1993-01-01

    The American phenomenon of pervasive monolingualism is considered, and potential implications of the North American Free Trade Agreement are described. Five second-language learning/teaching areas are projected: language for specific purposes; obligatory language study; exchange programs; technological advances; and information resources.…

  7. 48 CFR 3027.208 - Use of patented technology under the North American Free Trade Agreements.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Use of patented technology under the North American Free Trade Agreements. 3027.208 Section 3027.208 Federal Acquisition... American Free Trade Agreements. (f) Contracting officers shall ensure compliance. ...

  8. Age and fecundability in a North American preconception cohort study.

    Science.gov (United States)

    Wesselink, Amelia K; Rothman, Kenneth J; Hatch, Elizabeth E; Mikkelsen, Ellen M; Sørensen, Henrik T; Wise, Lauren A

    2017-12-01

    point fecundability was relatively stable. Fecundability ratios were 0.91 (95% confidence interval, 0.74-1.11) for ages 25-27, 0.88 (95% confidence interval, 0.72-1.08) for ages 28-30, 0.87 (95% confidence interval, 0.70-1.08) for ages 31-33, 0.82 (95% confidence interval, 0.64-1.05) for ages 34-36, 0.60 (95% confidence interval, 0.44-0.81) for ages 37-39, and 0.40 (95% confidence interval, 0.22-0.73) for ages 40-45, compared with the reference group (age, 21-24 years). The association was stronger among nulligravid women. Male age was not associated appreciably with fecundability after adjustment for female age, although the number of men >45 years old was small (n=37). In this preconception cohort study of North American pregnancy planners, increasing female age was associated with an approximately linear decline in fecundability. Although we found little association between male age and fecundability, the small number of men in our study >45 years old limited our ability to draw conclusions on fecundability in older men. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Multiformity of the tropical cyclone wind–pressure relationship in the western North Pacific: discrepancies among four best-track archives

    International Nuclear Information System (INIS)

    Kueh, Mien-Tze

    2012-01-01

    The reliability of tropical cyclone intensity estimates for the western North Pacific is assessed in the context of wind–pressure relationships. Four best-track datasets compiled in the International Best Track Archive for Climate Stewardship (IBTrACS) are compared to assess the data consistency. Over the past 20 yr period (1991–2010), apparent interagency discrepancies in the archived tropical cyclone intensities are found. Heavy reliance upon operational wind–pressure relationships may reduce subjective biases at the cost of potential loss of tropical cyclone natural variability. Given that the intercomparisons are performed based upon a set of identical tropical cyclones, the differences in operational wind–pressure relationships and in the mapping of satellite tropical cyclone intensity classification for these relationships are presumably critical causes of the interagency discrepancies. This result calls for imperative refinement of current satellite-based tropical cyclone intensity estimates and reanalysis of historical tropical cyclone best-track archives for the basin. (letter)

  10. The North American Monsoon GPS Hydrometeorological Network 2017: A New Look at an Old Problem

    Science.gov (United States)

    Adams, D. K.

    2017-12-01

    Quantifying moisture recycling and determining water vapor source regions for deep convective precipitation have been problematic, particular in tropical continental regions. More than an academic concern, modeling convective precipitation, from cloud-resolving to global climate models, depends critically on properly representing atmospheric water vapor transport, its vertical distribution, as well as surface latent heat flux contributions. The North American Monsoon region, given its complex topography, proximity to warm oceans, striking vegetation "green up" and oftentimes subtle dynamical forcing is particular challenging in this regard. Recent studies, employing modeling and observational approaches, give a prominent role for moisture recycling in fomenting deep convective precipitation. Likewise, these studies argue for the increased importance of transport from the Gulf of Mexico/Central America and the Atlantic Ocean, relative to the Pacific Ocean/Gulf of California. In this presentation, we critically review these studies which served to motivate the NAM GPS Hydrometeorological Network 2017, detailed here. This bi-national (Mexico-US) 3-month campaign to examine water vapor source regions, and specifically, land-surface water vapor fluxes consists of 10 experimental GPS meteorological sites as well as TLALOCNet and Suominet GPS sites in the Mexican states of Sonora, Chihuahua, Sinaloa, and Baja California and in Arizona and New Mexico. Near Rayón Sonora, inside the larger regional GPSmet array, a 30km eddy covariance flux tower triangular array, with collocated GPSmet, measures continuous energy fluxes and precipitable water vapor. Preliminary results examining the local flux contribution in the triangular array to total precipitable water vapor measured are presented. Further research is then outlined.

  11. Mesozooplankton Graze on Cyanobacteria in the Amazon River Plume and Western Tropical North Atlantic

    Directory of Open Access Journals (Sweden)

    Brandon J. Conroy

    2017-08-01

    Full Text Available Diazotrophic cyanobacteria, those capable of fixing di-nitrogen (N2, are considered one of the major sources of new nitrogen (N in the oligotrophic tropical ocean, but direct incorporation of diazotrophic N into food webs has not been fully examined. In the Amazon River-influenced western tropical North Atlantic (WTNA, diatom diazotroph associations (DDAs and the filamentous colonial diazotrophs Trichodesmium have seasonally high abundances. We sampled epipelagic mesozooplankton in the Amazon River plume and WTNA in May–June 2010 to investigate direct grazing by mesozooplankton on two DDA populations: Richelia associated with Rhizosolenia diatoms (het-1 and Hemiaulus diatoms (het-2, and on Trichodesmium using highly specific qPCR assays targeting nitrogenase genes (nifH. Both DDAs and Trichodesmium occurred in zooplankton gut contents, with higher detection of het-2 predominantly in calanoid copepods (2.33–16.76 nifH copies organism-1. Abundance of Trichodesmium was low (2.21–4.03 nifH copies organism-1, but they were consistently detected at high salinity stations (>35 in calanoid copepods. This suggests direct grazing on DDAs, Trichodesmium filaments and colonies, or consumption as part of sinking aggregates, is common. In parallel with the qPCR approach, a next generation sequencing analysis of 16S rRNA genes identified that cyanobacterial assemblage associated with zooplankton guts was dominated by the non-diazotrophic unicellular phylotypes Synechococcus (56% and Prochlorococcus (26%. However, in two separate calanoid copepod samples, two unicellular diazotrophs Candidatus Atelocyanobacterium thalassa (UCYN-A and Crocosphaera watsonii (UCYN-B were present, respectively, as a small component of cyanobacterial assemblages (<2%. This study represents the first evidence of consumption of DDAs, Trichodesmium, and unicellular cyanobacteria by calanoid copepods in an area of the WTNA known for high carbon export. These diazotroph populations

  12. Reconstructing medieval climate in the tropical North Atlantic with corals from Anegada, British Virgin Islands

    Science.gov (United States)

    Kilbourne, K. H.; Xu, Y. Y.

    2014-12-01

    Resolving the patterns of climate variability during the Medieval Climate Anomaly (MCA) is key for exploring forced versus unforced variability during the last 1000 years. Tropical Atlantic climate is currently not well resolved during the MCA despite it being an important source of heat and moisture to the climate system today. To fill this data gap, we collected cores from Diploria strigosa corals brought onto the low-lying island of Anegada, British Virgin Islands (18.7˚N, 64.3˚S) during an overwash event and use paired analysis of Sr/Ca and δ18O in the skeletal aragonite to explore climate in the tropical Atlantic at the end of the MCA. The three sub-fossil corals used in this analysis overlap temporally and together span the years 1256-1372 C.E. An assessment of three modern corals from the study site indicates that the most robust features of climate reconstructions using Sr/Ca and δ18O in this species are the seasonal cycle and inter-annual variability. The modern seasonal temperature range is 2.8 degrees Celsius and the similarity between the modern and sub-fossil coral Sr/Ca indicates a similar range during the MCA. Today seasonal salinity changes locally are driven in large part by the migration of a regional salinity front. The modern corals capture the related large seasonal seawater δ18O change, but the sub-fossil corals indicate stable seawater δ18O throughout the year, supporting the idea that this site remained on one side of the salinity front continuously throughout the year. Inter-annual variability in the region is influenced by the cross-equatorial SST gradient, the North Atlantic Oscillation and ENSO. Gridded instrumental SST from the area surrounding Anegada and coral geochemical records from nearby Puerto Rico demonstrate concentrations of variance in specific frequency bands associated with these phenomena. The sub-fossil coral shows no concentration of variance in the modern ENSO frequency band, consistent with reduced ENSO

  13. Phylogenetic assemblage structure of North American trees is more strongly shaped by glacial-interglacial climate variability in gymnosperms than in angiosperms.

    Science.gov (United States)

    Ma, Ziyu; Sandel, Brody; Svenning, Jens-Christian

    2016-05-01

    How fast does biodiversity respond to climate change? The relationship of past and current climate with phylogenetic assemblage structure helps us to understand this question. Studies of angiosperm tree diversity in North America have already suggested effects of current water-energy balance and tropical niche conservatism. However, the role of glacial-interglacial climate variability remains to be determined, and little is known about any of these relationships for gymnosperms. Moreover, phylogenetic endemism, the concentration of unique lineages in restricted ranges, may also be related to glacial-interglacial climate variability and needs more attention. We used a refined phylogeny of both angiosperms and gymnosperms to map phylogenetic diversity, clustering and endemism of North American trees in 100-km grid cells, and climate change velocity since Last Glacial Maximum together with postglacial accessibility to recolonization to quantify glacial-interglacial climate variability. We found: (1) Current climate is the dominant factor explaining the overall patterns, with more clustered angiosperm assemblages toward lower temperature, consistent with tropical niche conservatism. (2) Long-term climate stability is associated with higher angiosperm endemism, while higher postglacial accessibility is linked to to more phylogenetic clustering and endemism in gymnosperms. (3) Factors linked to glacial-interglacial climate change have stronger effects on gymnosperms than on angiosperms. These results suggest that paleoclimate legacies supplement current climate in shaping phylogenetic patterns in North American trees, and especially so for gymnosperms.

  14. Papers of the Canadian Institute's 8. annual North American pipelines and storage conference : update on critical infrastructure developments and market dynamics shaping the North American grid

    International Nuclear Information System (INIS)

    2003-01-01

    Leaders and experts from the petroleum and natural gas industry outlined some of the recent changes that have taken place in the North America gas and electricity industry. The relationship between pipeline and storage capacity was discussed with reference to how the connection affects prices at North American storage hubs. The topics of discussion ranged from the challenges associated with declines in capacity and market dynamics, to how gas marketability will be affected by the slowdown in pipeline development in North America. The investment community offered advice on long-run value creation in natural gas. The current state of development of Arctic gas was highlighted along with a review of how growth in liquefied natural gas (LNG) is changing the role of gas infrastructure in North America. It was noted that although markets will work to balance supply and demand, there is a need for new sources of North American supply to meet growing long-term demand. The fall-off in U.S. domestic natural gas supplies combined with low storage levels has created a supply crisis. The conference featured 19 presentations, of which 4 have been indexed separately for inclusion in this database. refs., tabs., figs

  15. Urban ecosystems and the North American carbon cycle

    Science.gov (United States)

    D.E. Pataki; R.J. Alig; A.S. Fung; E. Golubiewski; C.A. Kennedy; E.G. McPherson; D.J. Nowak; R.V. Pouyat; P. Romero Lankao

    2006-01-01

    Approximately 75-80% of the population of North America currently lives in urban areas as defined by national census bureaus, and urbanization is continuing to increase. Future trajectories of fossil fuel emissions are associated with a high degree of uncertainty; however, if the activities of urban residents and the rate of urban land conversion can be captured in...

  16. Adapting Nigerian Church Leadership Style for the North American Context

    Science.gov (United States)

    Ogbonnaya, John A.

    2017-01-01

    The transition from a usually autocratic to generally participative style of leadership has been a process full of frustration, anxiety, and concerns for Nigerian immigrant pastors in The Apostolic Church (TAC) North America. These pastors have brought the values, concepts, practices, and behavior which they learned in Nigeria to lead the American…

  17. North American forest disturbance mapped from a decadal Landsat record

    Science.gov (United States)

    Jeffrey G. Masek; Chengquan Huang; Robert Wolfe; Warren Cohen; Forrest Hall; Jonathan Kutler; Peder. Nelson

    2008-01-01

    Forest disturbance and recovery are critical ecosystem processes, but the spatial pattern of disturbance has never been mapped across North America. The LEDAPS (Landsat Ecosystem Disturbance Adaptive Processing System) project has assembled a wall-to-wall record of stand-clearing disturbance (clearcut harvest, fire) for the United States and Canada for the period 1990-...

  18. Hearts and Minds: Honors Programs in North American Christian Institutions

    Science.gov (United States)

    Bratt, Kenneth

    2010-01-01

    For readers outside North America, the concept of "honors education" may be confusing (since the word honours features in British and Commonwealth degree titles) or obscure (bringing to mind associations with aristocratic privilege or elitist competition). But in the United States the development of honors programs in colleges, and later honors…

  19. Poleward shifts in winter ranges of North American birds

    Science.gov (United States)

    Frank A. La Sorte; Frank R., III Thompson

    2007-01-01

    Climate change is thought to promote the poleward movement of geographic ranges; however, the spatial dynamics, mechanisms, and regional anthropogenic drivers associated with these trends have not been fully explored. We estimated changes in latitude of northern range boundaries, center of occurrence, and center of abundance for 254 species of winter avifauna in North...

  20. Internationalization in German Academic Libraries: Moving beyond North American Perspectives

    Science.gov (United States)

    Bordonaro, Karen; Rauchmann, Sabine

    2015-01-01

    This paper explores how internationalization is understood and experienced in German academic libraries. Its main purpose is to move the discussion of internationalization in academic libraries beyond the boundaries of English-speaking North America by investigating a European perspective. Its secondary purpose is to investigate the role of…

  1. Environmental Performance of North American Wood Panel Manufacturing

    Science.gov (United States)

    R. Bergman; D. Kaestner; A. Taylor

    2015-01-01

    Manufacturing building products such as wood panels has environmental impacts, including contributions to climate change. This paper is a compilation of four studies quantifying these impacts using the life-cycle assessment (LCA) method on five wood-based panel products made in North America during 2012. LCA is an internationally accepted and standardized method for...

  2. Impacts of Potential Aircraft Observations on Forecasts of Tropical Cyclones Over the Western North Pacific

    Science.gov (United States)

    2014-12-01

    tropical storm , red is a typhoon, and magenta is an extratropical cyclone. The numbers in each circle define the day in September 2008. (From...green is a tropical depression, yellow is a tropical storm , red is a typhoon, and magenta is an extratropical cyclone. The numbers in each circle define...depended on the location of the observation with respect to the storm and the altitude from which the observation provided a profile of winds

  3. 76 FR 16728 - North American Free Trade Agreement, Article 1904; NAFTA Panel Reviews; Request for Panel Review

    Science.gov (United States)

    2011-03-25

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free Trade Agreement... American Free Trade Agreement. Panel Review was requested of the U.S. Department of Commerce's final... INFORMATION: Chapter 19 of the North American Free Trade Agreement (``Agreement'') established a mechanism to...

  4. The Holocene history of the North American Monsoon: 'known knowns' and 'known unknowns' in understanding its spatial and temporal complexity

    Science.gov (United States)

    Metcalfe, Sarah E.; Barron, John A.; Davies, Sarah J.

    2015-01-01

    Evidence for climatic change across the North American Monsoon (NAM) and adjacent areas is reviewed, drawing on continental and marine records and the application of climate models. Patterns of change at 12,000, 9000, 6000 and 4000 cal yr BP are presented to capture the nature of change from the Younger Dryas (YD) and through the mid-Holocene. At the YD, conditions were cooler overall, wetter in the north and drier in the south, while moving into the Holocene wetter conditions became established in the south and then spread north as the NAM strengthened. Until c. 8000 cal yr BP, the Laurentide Ice Sheet influenced precipitation in the north by pushing the Bermuda High further south. The peak extent of the NAM seems to have occurred around 6000 cal yr BP. 4000 cal yr BP marks the start of important changes across the NAM region, with drying in the north and the establishment of the clear differences between the summer-rain dominated south and central areas and the north, where winter rain is more important. This differentiation between south and north is crucial to understanding many climate responses across the NAM. This increasing variability is coincident with the declining influence of orbital forcing. 4000 cal yr BP also marks the onset of significant anthropogenic activity in many areas. For the last 2000 years, the focus is on higher temporal resolution change, with strong variations across the region. The Medieval Climate Anomaly (MCA) is characterised by centennial scale ‘megadrought’ across the southwest USA, associated with cooler tropical Pacific SSTs and persistent La Niña type conditions. Proxy data from southern Mexico, Central America and the Caribbean reveal generally wetter conditions, whereas records from the highlands of central Mexico and much of the Yucatan are typified by long -term drought. The Little Ice Age (LIA), in the north, was characterised by cooler, wetter winter conditions that have been linked with increased

  5. Pattern Classification of Tropical Cyclone Tracks over the Western North Pacific using a Fuzzy Clustering Method

    Science.gov (United States)

    Kim, H.; Ho, C.; Kim, J.

    2008-12-01

    This study presents the pattern classification of tropical cyclone (TC) tracks over the western North Pacific (WNP) basin during the typhoon season (June through October) for 1965-2006 (total 42 years) using a fuzzy clustering method. After the fuzzy c-mean clustering algorithm to the TC trajectory interpolated into 20 segments of equivalent length, we divided the whole tracks into 7 patterns. The optimal number of the fuzzy cluster is determined by several validity measures. The classified TC track patterns represent quite different features in the recurving latitudes, genesis locations, and geographical pathways: TCs mainly forming in east-northern part of the WNP and striking Korean and Japan (C1); mainly forming in west-southern part of the WNP, traveling long pathway, and partly striking Japan (C2); mainly striking Taiwan and East China (C3); traveling near the east coast of Japan (C4); traveling the distant ocean east of Japan (C5); moving toward South China and Vietnam straightly (C6); and forming in the South China Sea (C7). Atmospheric environments related to each cluster show physically consistent with each TC track patterns. The straight track pattern is closely linked to a developed anticyclonic circulation to the north of the TC. It implies that this ridge acts as a steering flow forcing TCs to move to the northwest with a more west-oriented track. By contrast, recurving patterns occur commonly under the influence of the strong anomalous westerlies over the TC pathway but there definitely exist characteristic anomalous circulations over the mid- latitudes by pattern. Some clusters are closely related to the well-known large-scale phenomena. The C1 and C2 are highly related to the ENSO phase: The TCs in the C1 (C2) is more active during La Niña (El Niño). The TC activity in the C3 is associated with the WNP summer monsoon. The TCs in the C4 is more (less) vigorous during the easterly (westerly) phase of the stratospheric quasi-biennial oscillation

  6. Simulation of tropical cyclone activity over the western North Pacific based on CMIP5 models

    Science.gov (United States)

    Shen, Haibo; Zhou, Weican; Zhao, Haikun

    2017-09-01

    Based on the Coupled Model Inter-comparison Project 5 (CMIP5) models, the tropical cyclone (TC) activity in the summers of 1965-2005 over the western North Pacific (WNP) is simulated by a TC dynamically downscaling system. In consideration of diversity among climate models, Bayesian model averaging (BMA) and equal-weighed model averaging (EMA) methods are applied to produce the ensemble large-scale environmental factors of the CMIP5 model outputs. The environmental factors generated by BMA and EMA methods are compared, as well as the corresponding TC simulations by the downscaling system. Results indicate that BMA method shows a significant advantage over the EMA. In addition, impacts of model selections on BMA method are examined. To each factor, ten models with better performance are selected from 30 CMIP5 models and then conduct BMA, respectively. As a consequence, the ensemble environmental factors and simulated TC activity are similar with the results from the 30 models' BMA, which verifies the BMA method can afford corresponding weight for each model in the ensemble based on the model's predictive skill. Thereby, the existence of poor performance models will not particularly affect the BMA effectiveness and the ensemble outcomes are improved. Finally, based upon the BMA method and downscaling system, we analyze the sensitivity of TC activity to three important environmental factors, i.e., sea surface temperature (SST), large-scale steering flow, and vertical wind shear. Among three factors, SST and large-scale steering flow greatly affect TC tracks, while average intensity distribution is sensitive to all three environmental factors. Moreover, SST and vertical wind shear jointly play a critical role in the inter-annual variability of TC lifetime maximum intensity and frequency of intense TCs.

  7. Tropical cyclone-related socio-economic losses in the western North Pacific region

    Science.gov (United States)

    Welker, C.; Faust, E.

    2013-01-01

    The western North Pacific (WNP) is the area of the world most frequently affected by tropical cyclones (TCs). However, little is known about the socio-economic impacts of TCs in this region, probably because of the limited relevant loss data. Here, loss data from Munich RE's NatCatSERVICE database is used, a high-quality and widely consulted database of natural disasters. In the country-level loss normalisation technique we apply, the original loss data are normalised to present-day exposure levels by using the respective country's nominal gross domestic product at purchasing power parity as a proxy for wealth. The main focus of our study is on the question of whether the decadal-scale TC variability observed in the Northwest Pacific region in recent decades can be shown to manifest itself economically in an associated variability in losses. It is shown that since 1980 the frequency of TC-related loss events in the WNP exhibited, apart from seasonal and interannual variations, interdecadal variability with a period of about 22 yr - driven primarily by corresponding variations of Northwest Pacific TCs. Compared to the long-term mean, the number of loss events was found to be higher (lower) by 14% (9%) in the positive (negative) phase of the decadal-scale WNP TC frequency variability. This was identified for the period 1980-2008 by applying a wavelet analysis technique. It was also possible to demonstrate the same low-frequency variability in normalised direct economic losses from TCs in the WNP region. The identification of possible physical mechanisms responsible for the observed decadal-scale Northwest Pacific TC variability will be the subject of future research, even if suggestions have already been made in earlier studies.

  8. Tropical cyclone-related socio-economic losses in the western North Pacific region

    Directory of Open Access Journals (Sweden)

    C. Welker

    2013-01-01

    Full Text Available The western North Pacific (WNP is the area of the world most frequently affected by tropical cyclones (TCs. However, little is known about the socio-economic impacts of TCs in this region, probably because of the limited relevant loss data. Here, loss data from Munich RE's NatCatSERVICE database is used, a high-quality and widely consulted database of natural disasters. In the country-level loss normalisation technique we apply, the original loss data are normalised to present-day exposure levels by using the respective country's nominal gross domestic product at purchasing power parity as a proxy for wealth. The main focus of our study is on the question of whether the decadal-scale TC variability observed in the Northwest Pacific region in recent decades can be shown to manifest itself economically in an associated variability in losses. It is shown that since 1980 the frequency of TC-related loss events in the WNP exhibited, apart from seasonal and interannual variations, interdecadal variability with a period of about 22 yr – driven primarily by corresponding variations of Northwest Pacific TCs. Compared to the long-term mean, the number of loss events was found to be higher (lower by 14% (9% in the positive (negative phase of the decadal-scale WNP TC frequency variability. This was identified for the period 1980–2008 by applying a wavelet analysis technique. It was also possible to demonstrate the same low-frequency variability in normalised direct economic losses from TCs in the WNP region. The identification of possible physical mechanisms responsible for the observed decadal-scale Northwest Pacific TC variability will be the subject of future research, even if suggestions have already been made in earlier studies.

  9. Impacts of the Pacific Meridional Mode on Landfalling North Atlantic tropical cyclones

    Science.gov (United States)

    Zhang, Wei; Villarini, Gabriele; Vecchi, Gabriel A.; Murakami, Hiroyuki

    2018-02-01

    This study examines the impacts of the Pacific Meridional Mode (PMM) on North Atlantic tropical cyclones (TCs) making landfall along the coastal US, Caribbean Islands and Mexico, and provides insights on the underlying physical mechanisms using observations and model simulations. There is a statistically significant time-lagged association between spring PMM and the August-October US and Caribbean landfalling TCs. Specifically, the positive (negative) spring PMM events tend to be followed by fewer (more) TCs affecting the coastal US (especially over the Gulf of Mexico and Florida) and the Caribbean Islands. This lagged association is mainly caused by the lagged impacts of PMM on the El Niño Southern Oscillation (ENSO), and the subsequent impacts of ENSO on TC frequency and landfalls. Positive (negative) PMM events are largely followed by El Niño (La Niña) events, which lead to less (more) TC geneses close to the US coast (i.e., the Gulf of Mexico and the Caribbean Sea); this also leads to easterly (westerly) steering flow in the vicinity of the US and Caribbean coast, which is unfavorable (favorable) to TC landfall across the Gulf of Mexico, Florida and Caribbean Islands. Perturbation simulations with the state-of-the-art Geophysical Fluid Dynamics Laboratory Forecast-oriented Low Ocean Resolution Version of CM2.5 (FLOR) support the linkage between PMM and TC landfall activity. The time-lagged impacts of spring PMM on TC landfalling activity results in a new predictor to forecast seasonal TC landfall activity along the US (especially over the Gulf of Mexico and Florida) and Caribbean coastal regions.

  10. The distribution of thiamin and pyridoxine in the western tropical North Atlantic Amazon River plume

    Directory of Open Access Journals (Sweden)

    Laila Pualani Barada

    2013-03-01

    Full Text Available B-vitamins are recognized as essential organic growth factors for many organisms, although little is known about their abundance and distribution in marine ecosystems. Despite their metabolic functions regulating important enzymatic reactions, the methodology to directly measure different B-vitamins in aquatic environments has only recently been developed. Here, we present the first direct measurements of two B-vitamins, thiamin (B1 and pyridoxine (B6, in the Amazon River plume-influenced Western Tropical North Atlantic (WTNA Ocean, an area known to have high productivity, carbon (C and dinitrogen (N2 fixation, and C sequestration. The vitamins B1 and B6 ranged in concentrations from undetectable to 230 pM and 40 pM, respectively. Significantly higher concentrations were measured in the surface plume water at some stations and variation with salinity was observed, suggesting a possible riverine influence on those B-vitamins. The influences of vitamins B1 and B6 on biogeochemical processes such as C and N2 fixation were investigated using a linear-regression model that indicated that the availability of those organic factors could affect these rates in the WTNA. In fact, significant increases in C fixation and N2 fixation were observed with increasing vitamin B1 concentrations at some low and mesohaline stations (stations 9.1 and 1; p value <0.017 and <0.03, respectively. N2 fixation was also found to have a significant positive correlation with B1 concentrations at station 1 (p value = 0.029, as well as vitamin B6 at station 9.1 (p value <0.017. This work suggests that there can be a dynamic interplay between essential biogeochemical rates (C and N2 fixation and B-vitamins, drawing attention to potential roles of B-vitamins in ecosystem dynamics, community structure, and global biogeochemistry.

  11. Grazing by Zooplankton on Diazotrophs in the Amazon River Plume and Western Tropical North Atlantic

    Science.gov (United States)

    Conroy, B.; Steinberg, D. K.; Song, B.; Foster, R.

    2016-02-01

    Organisms capable of fixing di-nitrogen (N2), known as diazotrophs, are important primary producers and a potentially significant source for new nitrogen entering the planktonic food web. However, limited evidence exists for zooplankton grazing on diazotrophs compared to other primary producers. In the western tropical North Atlantic Ocean (WTNA), the Amazon River plume creates a niche for symbiotic diatom-diazotroph associations (DDAs) which can form large blooms. In adjacent non-plume-influenced waters, the colonial cyanobacterium Trichodesmium is abundant. In order to reveal zooplankton-diazotroph grazing interactions and determine the fate of newly fixed nitrogen, gut contents of zooplankton captured in these two regions were compared based on quantitative PCR (qPCR) assay of nitrogenase genes (nifH), and their microbiomes compared using next generation sequencing (NGS) analysis of 16S rRNA genes. We sampled individual copepods from discrete depth intervals (0-25m and 25-50m) and in two size classes (0.5-1mm and 1-2mm) for analysis. A modified DNA extraction protocol was developed and 54 extracts were used as templates in nifH qPCR assays for the larger size fraction diazotrophs (>10µm): Trichodesmium, and Hemiaulus or Rhizosolenia (diatoms)-Richelia (diazotroph) associations. Copepod gut content nifH copies ranged from 1.6 to 13.6 copies individual-1 for the assay targeting the Hemiaulus-Richelia DDA and from 1.1 to 3.0 copies individual-1 for Trichodesmium. 16S NGS conducted on 35 extracts with an Ion Torrent PGM and mothur revealed that cyanobacteria sequences accounted for up to 20% of sequences per extract. Our results show that both DDAs and Trichodesmium are prey for zooplankton, and that new nitrogen moves through the food web via these grazing interactions. These interactions should be considered in future explorations of the global ocean nitrogen cycle.

  12. Biogeochemistry of Recently Discovered Oxygen-Depleted Mesoscale Eddies in the Open Eastern Tropical North Atlantic

    Science.gov (United States)

    Fiedler, B.; Grundle, D.; Löscher, C. R.; Schütte, F.; Hauss, H.; Karstensen, J.; Silva, P.; Koertzinger, A.

    2016-02-01

    Severely oxygen-depleted mesoscale features in the open eastern tropical North Atlantic, which are formed in the Mauritanian upwelling region, were discovered only recently. So far, few remote surveys conducted with autonomous platforms such as moorings, underwater gliders and profiling floats have provided a very first insight into these mesoscale eddies. Due to their hydrographic properties such water bodies are well isolated from ambient waters and therefore can develop severe near-surface oxygen deficits. In this presentation we show results from the first-ever biogeochemical survey of one of these anticyclonic mode-water eddies conducted in spring 2014 at the Cape Verde Ocean Observatory (CVOO) off West Africa. Very low oxygen concentrations of 4.5 µmol kg-1 associated with a CO2 partial pressure of 1164 µatm were found close to the core of the eddy (at 100 m depth). Measurements for nitrate and phosphate also show exceptional high values. Findings point to rapid oxygen consumption through remineralization of organic matter along with depressed lateral mixing of this water body. Indeed, rates for oxygen utilization (OUR) were found to be enhanced when compared to known values in the Atlantic. A closer look into the carbonate system inside the eddýs core revealed disadvantageous conditions for calcifying organisms with the pH dropping down to 7.6 and the Aragonite saturation level reaching 1 at the lower boundary of the euphotic zone. Finally, strong indications for a shift in nitrogen cycling in the core of the eddy from nitrification towards denitrification were found based on gene abundance and N2O-isotope analyses. To our knowledge such severe hypoxic and even suboxic near-surface conditions along with active denitrification have never been reported before in the open Atlantic Ocean.

  13. Rainforests north of the Tropic of Cancer: Physiognomy, floristics and diversity in ‘lowland rainforests’ of Meghalaya, India

    Directory of Open Access Journals (Sweden)

    Uma Shankar

    2017-02-01

    Full Text Available The lowland rainforests of Meghalaya, India represent the westernmost limit of the rainforests north of the Tropic of Cancer. These forests, on the Shillong plateau, are akin to Whitmore's ‘tropical lowland evergreen rainforest’ formation and exhibit striking similarities and conspicuous differences with the equatorial rainforests in Asia-Pacific as well as tropical seasonal rainforests in southwestern China near the Tropic of Cancer. We found these common attributes of the rainforests in Meghalaya: familial composition with predominance of Euphorbiaceae, Lauraceae, Meliaceae, Moraceae, Myrsiticaceae, Myrtaceae and Rubiaceae; deciduousness in evergreen physiognomy; dominance of mega- and mesophanerophytic life-forms; abundance of species with low frequency of occurrence (rare and aggregated species; low proportional abundance of the abundant species; and truncated lognormal abundance distribution. The levels of stand density and stand basal area were comparable with seasonal rainforests in southwestern China, but were lower than equatorial rainforests. Tropical Asian species predominated flora, commanding 95% of the abundance. The differences include overall low stature (height of the forest, inconspicuous stratification in canopy, fewer species and individuals of liana, thicker understory, higher proportion of rare species, absence of locally endemic species and relatively greater dominance of Fagaceae and Theaceae. The richness of species per hectare (S was considerably lower at higher latitudes in Meghalaya than in equatorial rainforests, but was comparable with seasonal rainforests. Shannon's diversity index (H′ = 4.40 nats for ≥10 cm gbh and 4.25 nats for ≥30 cm gbh was lower on higher latitudes in Meghalaya in comparison to species-rich equatorial rainforests, but it was the highest among all lowland rainforests near the Tropic of Cancer.

  14. The geochemistry of loess: Asian and North American deposits compared

    Science.gov (United States)

    Muhs, Daniel R.

    2018-04-01

    Loess is widely distributed over Asia and North America and constitutes one of the most important surficial deposits that serve as terrestrial records of the Quaternary. The oldest Pleistocene loess in China is likely ∼2.6 Ma, thus spanning much or all of the Pleistocene. In North America, most loess is no older than the penultimate glacial period, with the exception of Alaska, where the record may go back to ∼3.0 Ma. On both continents, loess deposits date primarily to glacial periods, and interglacial or interstadial periods are represented by paleosols. Both glacial and non-glacial sources of silts that comprise the bulk of loess deposits are found on both continents. Although loess has been considered to be representative of the average upper continental crust, there are regionally distinctive compositions of loess in both Asia and North America. Loess deposits in Asia from Yakutia, Tajikistan, and China have compositionally distinct major element compositions, due to varying abundances of silicate minerals, carbonate minerals, and clay minerals. In North America, loess in the Mississippi River valley, the Great Plains, and Alaska are also distinguishable with regard to major element composition that reflects highly diverse source sediments. Trace element geochemistry (Sc-Th-Zr and the rare earth elements) also shows regional diversity of loess bodies, in both Asia and North America. On both continents, most loess bodies show significant contributions from later-cycle, altered sedimentary rocks, as opposed to direct derivation from igneous rocks. Further, some loess bodies have detectable contributions from mafic igneous rocks as well as major contributions from average, upper-crustal, felsic rocks. Intercalated paleosols in loess sections show geochemical compositions that differ significantly from the underlying loess parent materials. Ratios of soluble-to-insoluble elements show depletions in paleosols due to chemical weathering losses of calcite

  15. The geochemistry of loess: Asian and North American deposits compared

    Science.gov (United States)

    Muhs, Daniel R.

    2018-01-01

    Loess is widely distributed over Asia and North America and constitutes one of the most important surficial deposits that serve as terrestrial records of the Quaternary. The oldest Pleistocene loess in China is likely ∼2.6 Ma, thus spanning much or all of the Pleistocene. In North America, most loess is no older than the penultimate glacial period, with the exception of Alaska, where the record may go back to ∼3.0 Ma. On both continents, loess deposits date primarily to glacial periods, and interglacial or interstadial periods are represented by paleosols. Both glacial and non-glacial sources of silts that comprise the bulk of loess deposits are found on both continents. Although loess has been considered to be representative of the average upper continental crust, there are regionally distinctive compositions of loess in both Asia and North America. Loess deposits in Asia from Yakutia, Tajikistan, and China have compositionally distinct major element compositions, due to varying abundances of silicate minerals, carbonate minerals, and clay minerals. In North America, loess in the Mississippi River valley, the Great Plains, and Alaska are also distinguishable with regard to major element composition that reflects highly diverse source sediments. Trace element geochemistry (Sc-Th-Zr and the rare earth elements) also shows regional diversity of loess bodies, in both Asia and North America. On both continents, most loess bodies show significant contributions from later-cycle, altered sedimentary rocks, as opposed to direct derivation from igneous rocks. Further, some loess bodies have detectable contributions from mafic igneous rocks as well as major contributions from average, upper-crustal, felsic rocks. Intercalated paleosols in loess sections show geochemical compositions that differ significantly from the underlying loess parent materials. Ratios of soluble-to-insoluble elements show depletions in paleosols due to chemical weathering losses of calcite

  16. Worlds within Worlds: Audiences, Jargon, and North American Comics Discourse

    Directory of Open Access Journals (Sweden)

    Craig Fischer

    2010-09-01

    Full Text Available Let me begin by describing four recent acts of comics criticism, all connected to each other like dominoes falling: The first act: In 2007, the University Press of Mississippi published an English-language translation of Thierry Groensteen’s The System of Comics (Système de la bande dessinée, 1999. In their foreword to System, translators Bart Beaty and Nick Nguyen anticipate obstacles to the American reception of Groensteen’s ideas, arguing that American scholars are unfamiliar with the “do...

  17. ["Us" and "them": European and North American attitudes to immigration].

    Science.gov (United States)

    Livi-bacci, M

    1994-01-01

    This work compares attitudes toward immigration in Europe and North America. Europe has adopted and reinforced a restrictive immigration policy since the 1970s, but family reunification and asylum for refugees have replaced labor migration to maintain the flow of newcomers over the past two decades. Illegal immigration has increased in countries such as Italy and Spain where immigration is a recent phenomenon. Migratory pressure from the former Soviet block, violence against immigrants in Germany and elsewhere, the crisis of social protection systems, economic recession and increasing unemployment have pressured European governments to reinforce their closed door policy. In the US, restrictions against immigration have relaxed greatly since adoption of the Immigration Reform and Control Act in 1986. Over 800,000 immigrants have been admitted annually to the US in recent years. The factors explaining the different immigration policies in North America and Europe are not economic or demographic, but stem rather from history, social structure, the functioning of the labor market and social mobility. North America, more than Europe, has a positive view of immigration as contributing to the vitality and renewal of the culture and promoting development by broadening experience and knowledge. Immigration is regarded in Europe as, at best, a necessity in times of labor shortage and economic expansion. European countries tend to perceive themselves as totally formed and not requiring further cultural contribution. Homogeneity in culture, language, and religion is valued. Social mobility is possible in North America through professional success, but in the older and more hierarchical societies of Europe, social status is determined by birth and family or other connections. Since the early 1990s, public opinion toward immigration has become less favorable on both sides of the Atlantic, with increasing proportions favoring limitation. The positive perception of immigration in

  18. ?-Oryzanols of North American Wild Rice (Zizania palustris)

    OpenAIRE

    Aladedunye, Felix; Przybylski, Roman; Rudzinska, Magdalena; Klensporf-Pawlik, Dorota

    2013-01-01

    ?-Oryzanol, a natural mixture of ferulic acid esters of triterpene alcohols and sterols, are an important bioactive components present in rice bran oil. In light of the recent increase in the popularity of wild rice among consumers, and the possibility of a direct relationship between ?-oryzanol composition and its bioactivity, the oryzanol profile of major wild rice (Zizania palustris) grown in North America was studied and compared to regular brown rice (Oryza sativa L.). A total of twenty-...

  19. Changing climates, changing forests: A western North American perspective

    Science.gov (United States)

    Christopher J. Fettig; Mary L. Reid; Barbara J. Bentz; Sanna Sevanto; David L. Spittlehouse; T. Wang

    2013-01-01

    The Earth’s mean surface air temperature has warmed by ~1C over the last 100 years and is projected to increase at a faster rate in the future, accompanied by changes in precipitation patterns and increases in the occurrence of extreme weather events. In western North America, projected increases in mean annual temperatures range from ~1−3.5C by the 2050s,...

  20. Tribosphenic mammal from the North American Early Cretaceous.

    Science.gov (United States)

    Cifelli, R L

    1999-09-23

    The main groups of living mammals, marsupials and eutherians, are presumed to have diverged in the Early Cretaceous, but their early history and biogeography are poorly understood. Dental remains have suggested that the eutherians may have originated in Asia, spreading to North America in the Late Cretaceous, where an endemic radiation of marsupials was already well underway. Here I describe a new tribosphenic mammal (a mammal with lower molar heels that are three-cusped and basined) from the Early Cretaceous of North America, based on an unusually complete specimen. The new taxon bears characteristics (molarized last premolar, reduction to three molars) otherwise known only for Eutheria among the tribosphenic mammals. Morphometric analysis and character comparisons show, however, that its molar structure is primitive (and thus phylogenetically uninformative), emphasizing the need for caution in interpretation of isolated teeth. The new mammal is approximately contemporaneous with the oldest known Eutheria from Asia. If it is a eutherian, as is indicated by the available evidence, then this group was far more widely distributed in the Early Cretaceous than previously appreciated. An early presence of Eutheria in North America offers a potential source for the continent's Late Cretaceous radiations, which have, in part, proven difficult to relate to contemporary taxa in Asia.

  1. Hydrology Research with the North American Land Data Assimilation System (NLDAS) Datasets at the NASA GES DISC Using Giovanni

    Science.gov (United States)

    Mocko, David M.; Rui, Hualan; Acker, James G.

    2013-01-01

    The North American Land Data Assimilation System (NLDAS) is a collaboration project between NASA/GSFC, NOAA, Princeton Univ., and the Univ. of Washington. NLDAS has created a surface meteorology dataset using the best-available observations and reanalyses the backbone of this dataset is a gridded precipitation analysis from rain gauges. This dataset is used to drive four separate land-surface models (LSMs) to produce datasets of soil moisture, snow, runoff, and surface fluxes. NLDAS datasets are available hourly and extend from Jan 1979 to near real-time with a typical 4-day lag. The datasets are available at 1/8th-degree over CONUS and portions of Canada and Mexico from 25-53 North. The datasets have been extensively evaluated against observations, and are also used as part of a drought monitor. NLDAS datasets are available from the NASA GES DISC and can be accessed via ftp, GDS, Mirador, and Giovanni. GES DISC news articles were published showing figures from the heat wave of 2011, Hurricane Irene, Tropical Storm Lee, and the low-snow winter of 2011-2012. For this presentation, Giovanni-generated figures using NLDAS data from the derecho across the U.S. Midwest and Mid-Atlantic will be presented. Also, similar figures will be presented from the landfall of Hurricane Isaac and the before-and-after drought conditions of the path of the tropical moisture into the central states of the U.S. Updates on future products and datasets from the NLDAS project will also be introduced.

  2. Carbon sequestration potential of second-growth forest regeneration in the Latin American tropics.

    Science.gov (United States)

    Chazdon, Robin L; Broadbent, Eben N; Rozendaal, Danaë M A; Bongers, Frans; Zambrano, Angélica María Almeyda; Aide, T Mitchell; Balvanera, Patricia; Becknell, Justin M; Boukili, Vanessa; Brancalion, Pedro H S; Craven, Dylan; Almeida-Cortez, Jarcilene S; Cabral, George A L; de Jong, Ben; Denslow, Julie S; Dent, Daisy H; DeWalt, Saara J; Dupuy, Juan M; Durán, Sandra M; Espírito-Santo, Mario M; Fandino, María C; César, Ricardo G; Hall, Jefferson S; Hernández-Stefanoni, José Luis; Jakovac, Catarina C; Junqueira, André B; Kennard, Deborah; Letcher, Susan G; Lohbeck, Madelon; Martínez-Ramos, Miguel; Massoca, Paulo; Meave, Jorge A; Mesquita, Rita; Mora, Francisco; Muñoz, Rodrigo; Muscarella, Robert; Nunes, Yule R F; Ochoa-Gaona, Susana; Orihuela-Belmonte, Edith; Peña-Claros, Marielos; Pérez-García, Eduardo A; Piotto, Daniel; Powers, Jennifer S; Rodríguez-Velazquez, Jorge; Romero-Pérez, Isabel Eunice; Ruíz, Jorge; Saldarriaga, Juan G; Sanchez-Azofeifa, Arturo; Schwartz, Naomi B; Steininger, Marc K; Swenson, Nathan G; Uriarte, Maria; van Breugel, Michiel; van der Wal, Hans; Veloso, Maria D M; Vester, Hans; Vieira, Ima Celia G; Bentos, Tony Vizcarra; Williamson, G Bruce; Poorter, Lourens

    2016-05-01

    Regrowth of tropical secondary forests following complete or nearly complete removal of forest vegetation actively stores carbon in aboveground biomass, partially counterbalancing carbon emissions from deforestation, forest degradation, burning of fossil fuels, and other anthropogenic sources. We estimate the age and spatial extent of lowland second-growth forests in the Latin American tropics and model their potential aboveground carbon accumulation over four decades. Our model shows that, in 2008, second-growth forests (1 to 60 years old) covered 2.4 million km(2) of land (28.1% of the total study area). Over 40 years, these lands can potentially accumulate a total aboveground carbon stock of 8.48 Pg C (petagrams of carbon) in aboveground biomass via low-cost natural regeneration or assisted regeneration, corresponding to a total CO2 sequestration of 31.09 Pg CO2. This total is equivalent to carbon emissions from fossil fuel use and industrial processes in all of Latin America and the Caribbean from 1993 to 2014. Ten countries account for 95% of this carbon storage potential, led by Brazil, Colombia, Mexico, and Venezuela. We model future land-use scenarios to guide national carbon mitigation policies. Permitting natural regeneration on 40% of lowland pastures potentially stores an additional 2.0 Pg C over 40 years. Our study provides information and maps to guide national-level forest-based carbon mitigation plans on the basis of estimated rates of natural regeneration and pasture abandonment. Coupled with avoided deforestation and sustainable forest management, natural regeneration of second-growth forests provides a low-cost mechanism that yields a high carbon sequestration potential with multiple benefits for biodiversity and ecosystem services.

  3. Carbon sequestration potential of second-growth forest regeneration in the Latin American tropics

    Science.gov (United States)

    Chazdon, Robin L.; Broadbent, Eben N.; Rozendaal, Danaë M. A.; Bongers, Frans; Zambrano, Angélica María Almeyda; Aide, T. Mitchell; Balvanera, Patricia; Becknell, Justin M.; Boukili, Vanessa; Brancalion, Pedro H. S.; Craven, Dylan; Almeida-Cortez, Jarcilene S.; Cabral, George A. L.; de Jong, Ben; Denslow, Julie S.; Dent, Daisy H.; DeWalt, Saara J.; Dupuy, Juan M.; Durán, Sandra M.; Espírito-Santo, Mario M.; Fandino, María C.; César, Ricardo G.; Hall, Jefferson S.; Hernández-Stefanoni, José Luis; Jakovac, Catarina C.; Junqueira, André B.; Kennard, Deborah; Letcher, Susan G.; Lohbeck, Madelon; Martínez-Ramos, Miguel; Massoca, Paulo; Meave, Jorge A.; Mesquita, Rita; Mora, Francisco; Muñoz, Rodrigo; Muscarella, Robert; Nunes, Yule R. F.; Ochoa-Gaona, Susana; Orihuela-Belmonte, Edith; Peña-Claros, Marielos; Pérez-García, Eduardo A.; Piotto, Daniel; Powers, Jennifer S.; Rodríguez-Velazquez, Jorge; Romero-Pérez, Isabel Eunice; Ruíz, Jorge; Saldarriaga, Juan G.; Sanchez-Azofeifa, Arturo; Schwartz, Naomi B.; Steininger, Marc K.; Swenson, Nathan G.; Uriarte, Maria; van Breugel, Michiel; van der Wal, Hans; Veloso, Maria D. M.; Vester, Hans; Vieira, Ima Celia G.; Bentos, Tony Vizcarra; Williamson, G. Bruce; Poorter, Lourens

    2016-01-01

    Regrowth of tropical secondary forests following complete or nearly complete removal of forest vegetation actively stores carbon in aboveground biomass, partially counterbalancing carbon emissions from deforestation, forest degradation, burning of fossil fuels, and other anthropogenic sources. We estimate the age and spatial extent of lowland second-growth forests in the Latin American tropics and model their potential aboveground carbon accumulation over four decades. Our model shows that, in 2008, second-growth forests (1 to 60 years old) covered 2.4 million km2 of land (28.1% of the total study area). Over 40 years, these lands can potentially accumulate a total aboveground carbon stock of 8.48 Pg C (petagrams of carbon) in aboveground biomass via low-cost natural regeneration or assisted regeneration, corresponding to a total CO2 sequestration of 31.09 Pg CO2. This total is equivalent to carbon emissions from fossil fuel use and industrial processes in all of Latin America and the Caribbean from 1993 to 2014. Ten countries account for 95% of this carbon storage potential, led by Brazil, Colombia, Mexico, and Venezuela. We model future land-use scenarios to guide national carbon mitigation policies. Permitting natural regeneration on 40% of lowland pastures potentially stores an additional 2.0 Pg C over 40 years. Our study provides information and maps to guide national-level forest-based carbon mitigation plans on the basis of estimated rates of natural regeneration and pasture abandonment. Coupled with avoided deforestation and sustainable forest management, natural regeneration of second-growth forests provides a low-cost mechanism that yields a high carbon sequestration potential with multiple benefits for biodiversity and ecosystem services. PMID:27386528

  4. North American paragonimiasis (Caused by Paragonimus kellicotti) in the context of global paragonimiasis.

    Science.gov (United States)

    Procop, Gary W

    2009-07-01

    Paragonimus species are highly evolved parasites with a complex life cycle that involves at least three different hosts, i.e., snails, crustaceans, and mammals. The adult forms of Paragonimus species reside and mate in the lungs of a variety of permissive mammalian hosts, including humans. Although human paragonimiasis is uncommonly encountered in North America, both autochthonous and imported disease may be encountered. Paragonimus kellicotti, the species endemic to North America, is a well-known pathogen in wild and domestic animals. Five patients with North American paragonimiasis have been reported in the recent medical literature. The biologic, clinical, radiologic, and laboratory features of paragonimiasis are reviewed, with emphasis on North American paragonimiasis whenever possible.

  5. Business Guests Satisfaction in the Hotel Industry: A Case Study of North American Hotel Chains

    OpenAIRE

    Milan Bradić; Ljiljana Kosar; Bojana Kalenjuk

    2013-01-01

    This paper considers the problem of satisfaction of business guests with hotel brands in North America. In analysis we used the guests responses (scores) given for 12 different elements of hotel product. In order to arrive at more accurate results, monitored hotel chains are grouped into price tiers. The aim of this paper is to indicate what facilities and services the North American business guests appreciate most. Industry trends and results may be beneficial to all hoteliers, especially in...

  6. Analysis of GRI North American Regional Gas Supply-Demand Model

    International Nuclear Information System (INIS)

    Nesbitt, D.M.; Singh, J.; Pine, G.D.; Kline, D.; Barron, M.; Cheung, P.D.

    1989-01-01

    This paper summarizes the results from the GRI North American Regional Gas Supply-Demand Model using the four scenarios defined for the Energy Modeling Forum Number 9 (EMF-9) described in EMF-9 Working Paper 9.4 (1987). The analysis is designed both to showcase the GRI North American Regional model as well as to infer meaningful results about the North American natural gas system. The focus of the analysis is not R ampersand D per se; R ampersand D analysis using the model is conducted regularly by GRI and described elsewhere. Rather, the objective is to analyze some of the major uncertainties in the North American gas market, uncertainties that potentially affect all players including GRI. In particular, the authors seek to quantify the overall economic environment in which production, transmission, distribution, consumption, and R ampersand D decisions will be made and how different that overall environment might be under alternative assumptions. An attendant objective of this analysis has been to enlist economists from a range of organizations (producers, regulators, GRI, and consultants) to carefully scrutinize the GRI North American Regional model and results. In particular, the coauthors were assembled from diverse organizations to review and evaluate model outputs, applying their particular experience and perspective. The four EMF-9 scenarios upon which this paper is based are described in detail later in this document. Briefly, scenario one represents a world with a surfeit of gas and a relatively high oil price projection; scenario two considers a lower oil price forecast; scenario three assumes a pessimistic outlook for the gas resource base with the same oil prices as scenario one; and scenario four examines a higher level of demand for gas in the North American gas market. An important objective of this analysis is to illustrate the predictive power of multi-scenario comparisons (as contrasted with detailed analysis of any individual scenario)

  7. The history of South American tropical precipitation for the past 25,000 years.

    Science.gov (United States)

    Baker, P A; Seltzer, G O; Fritz, S C; Dunbar, R B; Grove, M J; Tapia, P M; Cross, S L; Rowe, H D; Broda, J P

    2001-01-26

    Long sediment cores recovered from the deep portions of Lake Titicaca are used to reconstruct the precipitation history of tropical South America for the past 25,000 years. Lake Titicaca was a deep, fresh, and continuously overflowing lake during the last glacial stage, from before 25,000 to 15,000 calibrated years before the present (cal yr B.P.), signifying that during the last glacial maximum (LGM), the Altiplano of Bolivia and Peru and much of the Amazon basin were wetter than today. The LGM in this part of the Andes is dated at 21,000 cal yr B.P., approximately coincident with the global LGM. Maximum aridity and lowest lake level occurred in the early and middle Holocene (8000 to 5500 cal yr B.P.) during a time of low summer insolation. Today, rising levels of Lake Titicaca and wet conditions in Amazonia are correlated with anomalously cold sea-surface temperatures in the northern equatorial Atlantic. Likewise, during the deglacial and Holocene periods, there were several millennial-scale wet phases on the Altiplano and in Amazonia that coincided with anomalously cold periods in the equatorial and high-latitude North Atlantic, such as the Younger Dryas.

  8. Auction pricing of network access for North American railways

    DEFF Research Database (Denmark)

    Harrod, Steven

    2013-01-01

    The question of pricing train paths for "open access" railway networks in North America is discussed. An auction process is suggested as necessary to maintain transparency in the contracting process. Multiple random samples of auction pricing for a single track railway line demonstrate...... that the infrastructure entity will receive approximately 15.6% less than the true value of the contracted train paths. This loss of revenue threatens the objective of reducing government subsidy for the railway network. (C) 2012 Elsevier Ltd. All rights reserved....

  9. Multilocus phylogeography and systematic revision of North American water shrews (genus: Sorex)

    Science.gov (United States)

    Hope, Andrew G.; Panter, Nicholas; Cook, Joseph A.; Talbot, Sandra L.; Nagorsen, David W.

    2014-01-01

    North American water shrews, which have traditionally included Sorex alaskanus, S. bendirii, and S. palustris, are widely distributed through Nearctic boreal forests and adapted for life in semiaquatic environments. Molecular mitochondrial signatures for these species have recorded an evolutionary history with variable levels of regional divergence, suggesting a strong role of Quaternary environmental change in speciation processes. We expanded molecular analyses, including more-comprehensive rangewide sampling of specimens representing North American water shrew taxa, except S. alaskanus, and sequencing of 4 independent loci from the nuclear and mitochondrial genomes. We investigated relative divergence of insular populations along the North Pacific Coast, and newly recognized diversity from southwestern montane locations, potentially representing refugial isolates. Congruent independent genealogies, lack of definitive evidence for contemporary gene flow, and high support from coalescent species trees indicated differentiation of 4 major geographic lineages over multiple glacial cycles of the late Quaternary, similar to a growing number of boreal taxa. Limited divergence of insular populations suggested colonization following the last glacial. Characterization of southwestern montane diversity will require further sampling but divergence over multiple loci is indicative of a relictual sky-island fauna. We have reviewed and revised North American water shrew taxonomy including the recognition of 3 species within what was previously known as S. palustris. The possibility of gene flow between most distantly related North American water shrew lineages coupled with unresolved early diversification of this group and other sibling species reflects a complex but potentially productive system for investigating speciation processes.

  10. North American natural gas supply dynamics: A focus on U.S. supply

    International Nuclear Information System (INIS)

    George, R.

    1999-01-01

    This paper discusses US natural gas supply dynamics in the context of the North American gas marketplace. Supply fundamentals are examined, methodology is briefly presented, regional supply outlooks are discussed. Assumptions, drivers and issues are highlighted. The analysis and outlook indicate that the sizeable North American resource base can be economically developed to supply growing US natural gas requirements. The major incremental supply sources are likely to come from deepwater Gulf of Mexico, Rocky Mountain regions, onshore Texas and imports from Canada. Given this outlook, major business and investment opportunities exist for the gas upstream and midstream sectors despite some short-term challenges

  11. A guide to processing bat acoustic data for the North American Bat Monitoring Program (NABat)

    Science.gov (United States)

    Reichert, Brian; Lausen, Cori; Loeb, Susan; Weller, Ted; Allen, Ryan; Britzke, Eric; Hohoff, Tara; Siemers, Jeremy; Burkholder, Braden; Herzog, Carl; Verant, Michelle

    2018-06-14

    The North American Bat Monitoring Program (NABat) aims to improve the state of conservation science for all species of bats shared by the United States, Canada, and Mexico. To accomplish this goal, NABat offers guidance and standardized protocols for acoustic monitoring of bats. In this document, “A Guide to Processing Bat Acoustic Data for the North American Bat Monitoring Program (NABat),” we provide general recommendations and specific workflows for the process of identifying bat species from acoustic files recorded using the NABat stationary point and mobile transect acoustic monitoring protocols.

  12. 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.

  13. Kokes Award for the 24th North American Catalysis Society Meeting

    Energy Technology Data Exchange (ETDEWEB)

    Rioux, Robert M. [Pennsylvania State Univ., University Park, PA (United States)

    2016-05-02

    The objective of the Richard. J. Kokes Travel Award program is to encourage the participation of students in the biennial North American Catalysis Society (NACS) Meetings. The Kokes Award covers a significant portion of the transportation, lodging, and conference registration costs. Eligible students must be enrolled at a North American university and need to present a paper at the meeting. The Kokes awardee will be required to contribute some time to the organizing committee to assist in meeting operations and to be present at the meeting during the entire time. Similar to the 23rd Kokes Award program, undergraduate students are also eligible for the 24th Kokes Award program.

  14. The impact of northern gas on North American gas infrastructure

    International Nuclear Information System (INIS)

    Letwin, S.

    2004-01-01

    The three business units that Enbridge operates are crude oil pipelines; natural gas liquids (NGL) transportation; and gas transmission and distribution. The need for more infrastructure will increase as the demand for natural gas increases. This presentation outlined the issues that surround and sometimes impede infrastructure development. It also emphasized the need for northern gas supply at a time when conventional natural gas supplies are decreasing and demand is growing. Additional LNG supply is required along with new supply from Alaska, Mackenzie Delta and the east coast. The issue of a secure source of supply was discussed along with northern gas expectations. It is expected that Mackenzie Delta gas (1.2 bcf/day) will be available by 2008 to 2010 and Alaska North Slope gas (4 bcf/day) will be available from 2012 to 2014. Gas demand by industrial, residential, commercial and power generation sectors across North America was illustrated. The challenge lies in creating infrastructure to move the supply to where it is most in demand. General infrastructure issues were reviewed, such as prices, regulatory streamlining, lead times, stakeholder issues and supporting infrastructure. 19 figs

  15. Characterization of North American lignite fly ashes. II. XRD Mineralogy

    International Nuclear Information System (INIS)

    McCarthy, G.J.; Johansen, D.M.; Thedchanamoorthy, A.; Steinwand, S.J.; Swanson, K.D.

    1988-01-01

    X-ray powder diffraction has been used to determine the crystalline phase mineralogy in samples of fly ash from each of the lignite mining areas of North America. The characteristic phases of North Dakota lignite fly ashes were periclase, lime, merwinite and the sulfate phases anhydrite, thenardite and a sodalite-structure phase. Mullite was absent in these low-Al/sub 2/O/sub 3/ ashes. Montana lignite ash mineralogy had characteristics of ND lignite and MT subbituminous coal fly ashes; mullite and C/sub 3/A were present and the alkali sulfates were absent. Texas and Louisiana lignite fly ashes had the characteristic mineralogy of bituminous coal fly ash: quartz, mullite, ferrite-spinel (magnetite) and minor hematite. Even though their analytical CaO contents were 7-14%, all but one lacked crystalline CaO-containing phases. Lignite fly ashes from Saskatchewan were generally the least crystalline of those studied and had a mineralogy consisting of quartz, mullite, ferrite spinel and periclase. Quantitative XRD data were obtained. The position of the diffuse scattering maximum in the x-ray diffractograms was indicative of the glass composition of the lignite fly ash

  16. Role of the Convective Scheme in Modeling Initiation and Intensification of Tropical Depressions over the North Atlantic

    Science.gov (United States)

    Duvel, Jean Philippe; Camargo, Suzana; Sobel, Adam

    2016-04-01

    Modifications of the large-scale environment related to intraseasonal (MJO) and interannual (ENSO) time-scale variability or to global climate warming may have important impacts on the tropical cyclonic activity. This sensitivity of tropical cyclones (TC) on environmental changes can now be studied using General Circulation Models (GCM). Before doing sensitivity studies with a GCM, it is interesting to assess the representation of the TC activity for different configurations (resolution, parameterization) of the GCM in present climate conditions and to trace possible causes of bias in TC number, location or strength. A possible approach to do this assessment is to separate initiation and intensification processes. By using either GCM output, or meteorological analysis combined to TC observation databases, it is possible to study the condition of formation of tropical depressions vortices (TDV) at an early stage and their possible intensification into a TC (say the Tropical Storm stage). We use the LMDZ GCM to study the sensitivity of TDV characteristics to different entrainment and closure formulations of the convective scheme. The study focuses on the Tropical North Atlantic using the "zoom" capability of the LMDZ GCM. The horizontal resolution of the model is set to 0.75° over a large region of the North Atlantic and West Africa. The GCM is free to run in this region and is tied to ERA-Interim reanalysis outside that region, with intermediate relaxation times in-between. We use the Tiedtke convective scheme with entrainment and closure based on the moisture convergence, or with an entrainment based on the relative humidity of the environment, and additionally a closure based on CAPE. Each configuration is run for 10 years between 2000 and 2009 with prescribed SST. In summary, the convective entrainment based on the relative humidity in the environment deepens the TDV in LMDZ, resulting in more TDV and TC. The convective closure mitigates this tendency and

  17. A New Estimate of North American Mountain Snow Accumulation From Regional Climate Model Simulations

    Science.gov (United States)

    Wrzesien, Melissa L.; Durand, Michael T.; Pavelsky, Tamlin M.; Kapnick, Sarah B.; Zhang, Yu; Guo, Junyi; Shum, C. K.

    2018-02-01

    Despite the importance of mountain snowpack to understanding the water and energy cycles in North America's montane regions, no reliable mountain snow climatology exists for the entire continent. We present a new estimate of mountain snow water equivalent (SWE) for North America from regional climate model simulations. Climatological peak SWE in North America mountains is 1,006 km3, 2.94 times larger than previous estimates from reanalyses. By combining this mountain SWE value with the best available global product in nonmountain areas, we estimate peak North America SWE of 1,684 km3, 55% greater than previous estimates. In our simulations, the date of maximum SWE varies widely by mountain range, from early March to mid-April. Though mountains comprise 24% of the continent's land area, we estimate that they contain 60% of North American SWE. This new estimate is a suitable benchmark for continental- and global-scale water and energy budget studies.

  18. 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...

  19. Where Does The Carbon Go? Carbon Dynamics And Fire of a North Australian Tropical Savanna

    Science.gov (United States)

    Hutley, L. B.; Beringer, J.; Tapper, N. J.; Cernusak, L.

    2007-12-01

    The role of fire as one of the primary natural carbon cycling mechanisms is a key issue in considering global change feedbacks. In north Australia, the dominant ecosystem is tropical savanna and for mesic savannas within 100 km of the northern coastline, fire, storms and cyclones all impact carbon stocks. Fire is the most frequent disturbance agent as fires burn with a near annual frequency in these systems. We aimed to determine the annual net ecosystem productivity (NEP) from these savannas and the impact of fire on productivity. We established a long-term eddy covariance flux tower at Howard Springs, Australia and present here 5 years of data from 2001 to 2005. Fire has direct impacts through emissions but also has indirect effects through the loss of productivity due to reduced functional leaf area index and the carbon costs of rebuilding the canopy. The impact of fire on the canopy latent energy exchange was evident for 40 days while the canopy was rebuilt; however, the carbon balance took approximately 70 days to recover. The annual fire free NEP at Howard Springs was estimated at -4.3 t C ha-1 y-1 with a range of -3.5 to -5.1 t C ha-1 y-1 across years. We calculated the average annual indirect fire effect as 0.7 t C ha-1 y-1 using a neural network model approach and estimated average emissions of fine and coarse fuels as 1.6 t C ha-1 y-1. This allowed us to calculate a net biome production of 2.0 t C ha-1 y-1. We then partitioned this remaining sink and suggest that most of this can be accounted for by woody increment (1.2 t C ha-1 y-1) and shrub encroachment (0.5 t C ha-1 y-1). Given the consistent sink at this site, even under an almost annual fire regime, there may be management options to increase carbon sequestration by reducing fire frequency.

  20. Evaluating controls on planktonic foraminiferal geochemistry in the Eastern Tropical North Pacific

    Science.gov (United States)

    Gibson, Kelly Ann; Thunell, Robert C.; Machain-Castillo, Maria Luisa; Fehrenbacher, Jennifer; Spero, Howard J.; Wejnert, Kate; Nava-Fernández, Xinantecatl; Tappa, Eric J.

    2016-10-01

    To explore relationships between water column hydrography and foraminiferal geochemistry in the Eastern Tropical North Pacific, we present δ18O and Mg/Ca records from three species of planktonic foraminifera, Globigerinoides ruber, Globigerina bulloides, and Globorotalia menardii, collected from a sediment trap mooring maintained in the Gulf of Tehuantepec from 2006-2012. Differences in δ18O between mixed-layer species G. ruber and G. bulloides and thermocline-dweller G. menardii track seasonal changes in upwelling. The records suggest an increase in upwelling during the peak positive phase of El Niño, and an overall reduction in stratification over the six-year period. For all three species, Mg/Ca ratios are higher than what has been reported in previous studies, and show poor correlations to calcification temperature. We suggest that low pH (7.6-8.0) and [3 2-CO] values (∼70-120 μmol/kg) in the mixed layer contribute to an overall trend of higher Mg/Ca ratios in this region. Laser Ablation Inductively Coupled Mass Spectrometry analyses of G. bulloides with high Mg/Ca ratios (>9 mmol/mol) reveal the presence of a secondary coating of inorganic calcite that has Mg/Ca and Mn/Ca ratios up to an order of magnitude higher than these elemental ratios in the primary calcite, along with elevated Sr/Ca and Ba/Ca ratios. Some of the samples with abnormally high Mg/Ca are found during periods of high primary productivity, suggesting the alteration may be related to changes in carbonate saturation resulting from remineralization of organic matter in oxygen-poor waters in the water column. Although similar shell layering has been observed on fossil foraminifera, this is the first time such alteration has been studied in shells collected from the water column. Our results suggest a role for seawater carbonate chemistry in influencing foraminiferal calcite trace element:calcium ratios prior to deposition on the seafloor, particularly in high-productivity, low

  1. Lead and stable Pb-isotope characteristics of tropical soils in north-eastern Brazil

    International Nuclear Information System (INIS)

    Schucknecht, Anne; Matschullat, Jörg; Reimann, Clemens

    2011-01-01

    Stable Pb-isotope ratios are widely used as tracers for Pb-sources in the environment. Recently, a few publications have challenged the predominating view of environmental applications of Pb-isotopes. Present applications of Pb-isotopic tracers in soils largely represent the northern hemisphere. This study focuses on tropical soils from Paraíba, north-eastern Brazil. Lead concentrations and Pb-isotopic signatures (both 7N HNO 3 ) were determined at 30 sites along a 327 km E–W-transect, from the Atlantic coast at João Pessoa to some kilometers west of Patos, to identify possible processes for the observed (and anticipated) distribution pattern. Thirty samples each of litter (ORG) and top mineral soil (TOP) were taken on pasture land at suitable distance from roads or other potential contamination sources. Lead-content was determined by inductively-coupled plasma atomic emission spectrometry (ICP-AES) and the ratios of 206 Pb/ 207 Pb, 206 Pb/ 208 Pb, and 208 Pb/ 207 Pb by ICP-sector field mass spectrometry (ICP-SFMS). Both sample materials show similarly low Pb-concentrations with a lower median in the ORG samples (ORG 3.4 mg kg −1 versus TOP 6.9 mg kg −1 ). The 206 Pb/ 207 Pb ratios revealed a large spread along the transect with median 206 Pb/ 207 Pb ratios of 1.160 (ORG) and 1.175 (TOP). The 206 Pb/ 207 Pb ratios differ noticeably between sample sites located in the Atlantic Forest biome along the coast and sample sites in the inland Caatinga biome. The “forest” sites were characterised by a significant lower median and a lower spread in the 206 Pb/ 207 Pb and 206 Pb/ 208 Pb ratios compared to the Caatinga sites. Results indicate a very restricted influence of anthropogenic activities (individual sites only). The main process influencing the spatial variability of Pb-isotope ratios is supposed to be precipitation-dependent bioproductivity and weathering.

  2. Polyunsaturated fatty acids in various macroalgal species from North Atlantic and tropical seas.

    Science.gov (United States)

    van Ginneken, Vincent J T; Helsper, Johannes P F G; de Visser, Willem; van Keulen, Herman; Brandenburg, Willem A

    2011-06-22

    In this study the efficacy of using marine macroalgae as a source for polyunsaturated fatty acids, which are associated with the prevention of inflammation, cardiovascular diseases and mental disorders, was investigated. The fatty acid (FA) composition in lipids from seven sea weed species from the North Sea (Ulva lactuca, Chondrus crispus, Laminaria hyperborea, Fucus serratus, Undaria pinnatifida, Palmaria palmata, Ascophyllum nodosum) and two from tropical seas (Caulerpa taxifolia, Sargassum natans) was determined using GCMS. Four independent replicates were taken from each seaweed species. Omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids (PUFAs), were in the concentration range of 2-14 mg/g dry matter (DM), while total lipid content ranged from 7-45 mg/g DM. The n-9 FAs of the selected seaweeds accounted for 3%-56% of total FAs, n-6 FAs for 3%-32% and n-3 FAs for 8%-63%. Red and brown seaweeds contain arachidonic (C20:4, n-6) and/or eicosapentaenoic acids (EPA, C20:5, n-3), the latter being an important "fish" FA, as major PUFAs while in green seaweeds these values are low and mainly C16 FAs were found. A unique observation is the presence of another typical "fish" fatty acid, docosahexaenoic acid (DHA, C22:6, n-3) at ≈ 1 mg/g DM in S. natans. The n-6: n-3 ratio is in the range of 0.05-2.75 and in most cases below 1.0. Environmental effects on lipid-bound FA composition in seaweed species are discussed. Marine macroalgae form a good, durable and virtually inexhaustible source for polyunsaturated fatty acids with an (n-6) FA: (n-3) FA ratio of about 1.0. This ratio is recommended by the World Health Organization to be less than 10 in order to prevent inflammatory, cardiovascular and nervous system disorders. Some marine macroalgal species, like P. palmata, contain high proportions of the "fish fatty acid" eicosapentaenoic acid (EPA, C20:5, n-3), while in S. natans also docosahexaenoic acid (DHA, C22:6, n-3) was detected.

  3. Polyunsaturated fatty acids in various macroalgal species from north Atlantic and tropical seas

    Directory of Open Access Journals (Sweden)

    van Keulen Herman

    2011-06-01

    Full Text Available Abstract Background In this study the efficacy of using marine macroalgae as a source for polyunsaturated fatty acids, which are associated with the prevention of inflammation, cardiovascular diseases and mental disorders, was investigated. Methods The fatty acid (FA composition in lipids from seven sea weed species from the North Sea (Ulva lactuca, Chondrus crispus, Laminaria hyperborea, Fucus serratus, Undaria pinnatifida, Palmaria palmata, Ascophyllum nodosum and two from tropical seas (Caulerpa taxifolia, Sargassum natans was determined using GCMS. Four independent replicates were taken from each seaweed species. Results Omega-3 (n-3 and omega-6 (n-6 polyunsaturated fatty acids (PUFAs, were in the concentration range of 2-14 mg/g dry matter (DM, while total lipid content ranged from 7-45 mg/g DM. The n-9 FAs of the selected seaweeds accounted for 3%-56% of total FAs, n-6 FAs for 3%-32% and n-3 FAs for 8%-63%. Red and brown seaweeds contain arachidonic (C20:4, n-6 and/or eicosapentaenoic acids (EPA, C20:5, n-3, the latter being an important "fish" FA, as major PUFAs while in green seaweeds these values are low and mainly C16 FAs were found. A unique observation is the presence of another typical "fish" fatty acid, docosahexaenoic acid (DHA, C22:6, n-3 at ≈ 1 mg/g DM in S. natans. The n-6: n-3 ratio is in the range of 0.05-2.75 and in most cases below 1.0. Environmental effects on lipid-bound FA composition in seaweed species are discussed. Conclusion Marine macroalgae form a good, durable and virtually inexhaustible source for polyunsaturated fatty acids with an (n-6 FA: (n-3 FA ratio of about 1.0. This ratio is recommended by the World Health Organization to be less than 10 in order to prevent inflammatory, cardiovascular and nervous system disorders. Some marine macroalgal species, like P. palmata, contain high proportions of the "fish fatty acid" eicosapentaenoic acid (EPA, C20:5, n-3, while in S. natans also docosahexaenoic acid (DHA, C

  4. Coccolithophore fluxes in the open tropical North Atlantic: influence of thermocline depth, Amazon water, and Saharan dust

    Science.gov (United States)

    Guerreiro, Catarina V.; Baumann, Karl-Heinz; Brummer, Geert-Jan A.; Fischer, Gerhard; Korte, Laura F.; Merkel, Ute; Sá, Carolina; de Stigter, Henko; Stuut, Jan-Berend W.

    2017-10-01

    Coccolithophores are calcifying phytoplankton and major contributors to both the organic and inorganic oceanic carbon pumps. Their export fluxes, species composition, and seasonal patterns were determined in two sediment trap moorings (M4 at 12° N, 49° W and M2 at 14° N, 37° W) collecting settling particles synchronously from October 2012 to November 2013 at 1200 m of water depth in the open equatorial North Atlantic. The two trap locations showed a similar seasonal pattern in total coccolith export fluxes and a predominantly tropical coccolithophore settling assemblage. Species fluxes were dominated throughout the year by lower photic zone (LPZ) taxa (Florisphaera profunda, Gladiolithus flabellatus) but also included upper photic zone (UPZ) taxa (Umbellosphaera spp., Rhabdosphaera spp., Umbilicosphaera spp., Helicosphaera spp.). The LPZ flora was most abundant during fall 2012, whereas the UPZ flora was more important during summer. In spite of these similarities, the western part of the study area produced persistently higher fluxes, averaging 241×107 ± 76×107 coccoliths m-2 d-1 at station M4 compared to only 66×107 ± 31×107 coccoliths m-2 d-1 at station M2. Higher fluxes at M4 were mainly produced by the LPZ species, favoured by the westward deepening of the thermocline and nutricline. Still, most UPZ species also contributed to higher fluxes, reflecting enhanced productivity in the western equatorial North Atlantic. Such was the case of two marked flux peaks of the more opportunistic species Gephyrocapsa muellerae and Emiliania huxleyi in January and April 2013 at M4, indicating a fast response to the nutrient enrichment of the UPZ, probably by wind-forced mixing. Later, increased fluxes of G. oceanica and E. huxleyi in October-November 2013 coincided with the occurrence of Amazon-River-affected surface waters. Since the spring and fall events of 2013 were also accompanied by two dust flux peaks, we propose a scenario in which atmospheric dust also

  5. Cenozoic North American Drainage Basin Evolution, Sediment Yield, and Accumulation in the Gulf of Mexico Basin

    Science.gov (United States)

    Galloway, W.; Ganey-Curry, P. E.

    2010-12-01

    The Cenozoic fill of the Gulf of Mexico basin contains a continuous record of sediment supply from the North American continental interior for the past 65 million years. Regional mapping of unit thickness and paleogeography for 18 depositional episodes defines patterns of shifting entry points of continental fluvial systems and quantifies the total volume of sediment supplied during each episode. Eight fluvio-deltaic depocenters, named for geographic similarities to entry points and drainage basins of modern rivers, are present. From southwest to northeast, they are the Rio Bravo, Rio Grande, Guadalupe, Colorado, Houston-Brazos, Red, Mississippi, and Tennessee axes. Sediment volume was calculated from hand-contoured unit thickness maps compiled from basin-wide well and seismic control. Using a GIS algorithm to sum volumes within polygons bounding interpreted North American river contribution, the total extant volume was then calculated. General compaction factors were used to convert modern volume to quantitative approximations of total grain volume. Grain volume rate of supply for each depositional episode was then calculated. Values vary by more than an order of magnitude. Supply rate has commonly varied by two-fold or more between successive depositional episodes. Sediment supply is a significant, independent variable in development of stratigraphic sequences within the Gulf basin. Paleogeographic maps of the continental interior for eleven Cenozoic time intervals display the evolving and complex interplay of intracontinental tectonism, climate change, and drainage basin evolution. Five tectono-climatic eras are differentiated: Paleocene late Laramide era; early to middle Eocene terminal Laramide era; middle Cenozoic (Late Eocene—Early Miocene) dry, volcanogenic era; middle Neogene (Middle—Late Miocene) arid, extensional era; and late Neogene (Plio—Pleistocene) monsoonal, epeirogenic uplift era. Sediment supply to the GOM reflects the interplay of (1

  6. Western North Pacific Tropical Cyclone Formation and Structure Change in TCS-08

    Science.gov (United States)

    2012-09-30

    cyclones often transition to a fast-moving and rapidly- developing extratropical cyclone that may contain gale-, storm -, or hurricane-force winds...there is a need to improve understanding and prediction of the extratropical transition phase of a decaying tropical cyclone. The structural evolution...of the transition from a tropical to an extratropical circulation involves rapid changes to the wind, cloud, and precipitation patterns that

  7. Comparing the 2010 North American and European atrial fibrillation guidelines.

    Science.gov (United States)

    Gillis, Anne M; Skanes, Allan C

    2011-01-01

    This article compares the important differences in the American College of Cardiology Foundation (ACCF)/American Heart Association (AHA)/Heart Rhythm Society (HRS), Canadian Cardiovascular Society (CCS), and European Society of Cardiology (ESC) 2010 guidelines on atrial fibrillation (AF). All guidelines recommend more lenient targets for ventricular rate control although the CCS guidelines recommend a target heart rate at rest guidelines accept a target heart rate at rest guidelines recommend that the choice of antiarrhythmic drug for maintenance of sinus rhythm be based on the underlying cardiovascular disease state. However, the CCS guidelines do not recommend that the use of Class IC drugs or sotalol be restricted in the presence of left ventricular hypertrophy alone. All the guidelines have incorporated dronedarone into their recommendations of antiarrhythmic drug therapy for maintenance of sinus rhythm. However, the CCS guidelines do not make a specific recommendation that the use of dronedarone is reasonable to decrease the risk of hospitalization for cardiovascular causes in patients with AF. The ACCF/AHA/HRS update makes a strong recommendation for catheter ablation in patients with paroxysmal AF who have failed a single anti-arrhythmic drug whereas the CCS and ESC guidelines make this a conditional recommendation. The CCS guidelines are the only guidelines at present that recommend dabigitran for prevention of stroke in high risk patients and suggest that dabigatran is preferred to warfarin for stroke prevention in most patient groups. Copyright © 2011 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  8. Evaluation of harvest and information needs for North American sea ducks.

    Science.gov (United States)

    Koneff, Mark D; Zimmerman, Guthrie S; Dwyer, Chris P; Fleming, Kathleen K; Padding, Paul I; Devers, Patrick K; Johnson, Fred A; Runge, Michael C; Roberts, Anthony J

    2017-01-01

    Wildlife managers routinely seek to establish sustainable limits of sport harvest or other regulated forms of take while confronted with considerable uncertainty. A growing body of ecological research focuses on methods to describe and account for uncertainty in management decision-making and to prioritize research and monitoring investments to reduce the most influential uncertainties. We used simulation methods incorporating measures of demographic uncertainty to evaluate risk of overharvest and prioritize information needs for North American sea ducks (Tribe Mergini). Sea ducks are popular game birds in North America, yet they are poorly monitored and their population dynamics are poorly understood relative to other North American waterfowl. There have been few attempts to assess the sustainability of harvest of North American sea ducks, and no formal harvest strategy exists in the U.S. or Canada to guide management. The popularity of sea duck hunting, extended hunting opportunity for some populations (i.e., special seasons and/or bag limits), and population declines have led to concern about potential overharvest. We used Monte Carlo simulation to contrast estimates of allowable harvest and observed harvest and assess risk of overharvest for 7 populations of North American sea ducks: the American subspecies of common eider (Somateria mollissima dresseri), eastern and western populations of black scoter (Melanitta americana) and surf scoter (M. perspicillata), and continental populations of white-winged scoter (M. fusca) and long-tailed duck (Clangula hyemalis). We combined information from empirical studies and the opinions of experts through formal elicitation to create probability distributions reflecting uncertainty in the individual demographic parameters used in this assessment. Estimates of maximum growth (rmax), and therefore of allowable harvest, were highly uncertain for all populations. Long-tailed duck and American common eider appeared to be at high

  9. North American osprey populations and contaminants: Historic and contemporary perspectives

    Science.gov (United States)

    Henny, Charles J.; Grove, Robert A.; Kaiser, James L.; Johnson, Branden L.

    2010-01-01

    Osprey (Pandion haliaetus) populations were adversely affected by DDT and perhaps other contaminants in the United States and elsewhere. Reduced productivity, eggshell thinning, and high DDE concentrations in eggs were the signs associated with declining osprey populations in the 1950s, 1960s, and 1970s. The species was one of the first studied on a large scale to bring contaminant issues into focus. Although few quantitative population data were available prior to the 1960s, many osprey populations in North America were studied during the 1960s and 1970s with much learned about basic life history and biology. This article reviews the historical and current effects of contaminants on regional osprey populations. Breeding populations in many regions of North America showed post-DDT-era (1972) population increases of varying magnitudes, with many populations now appearing to stabilize at much higher numbers than initially reported in the 1970s and 1980s. However, the magnitude of regional population increases in the United States between 1981 (first Nationwide Survey, ∼8,000 pairs), when some recovery had already occurred, 1994 (second survey, ∼14,200), and 2001 (third survey, ∼16,000–19,000), or any other years, is likely not a simple response to the release from earlier contaminant effects, but a response to multi-factorial effects. This indirect “contaminant effects” measurement comparing changes (i.e., recovery) in post-DDT-era population numbers over time is probably confounded by changing human attitudes toward birds of prey (shooting, destroying nests, etc.), changing habitats, changing fish populations, and perhaps competition from other species. The species' adaptation to newly created reservoirs and its increasing use of artificial nesting structures (power poles, nesting platforms, cell towers, channel markers, offshore duck blinds, etc.) are two important factors. The timing of the initial use of artificial nesting structures, which replaced

  10. Current and future niche of North and Central American sand flies (Diptera: psychodidae in climate change scenarios.

    Directory of Open Access Journals (Sweden)

    David Moo-Llanes

    Full Text Available Ecological niche models are useful tools to infer potential spatial and temporal distributions in vector species and to measure epidemiological risk for infectious diseases such as the Leishmaniases. The ecological niche of 28 North and Central American sand fly species, including those with epidemiological relevance, can be used to analyze the vector's ecology and its association with transmission risk, and plan integrated regional vector surveillance and control programs. In this study, we model the environmental requirements of the principal North and Central American phlebotomine species and analyze three niche characteristics over future climate change scenarios: i potential change in niche breadth, ii direction and magnitude of niche centroid shifts, iii shifts in elevation range. Niche identity between confirmed or incriminated Leishmania vector sand flies in Mexico, and human cases were analyzed. Niche models were constructed using sand fly occurrence datapoints from Canada, USA, Mexico, Guatemala and Belize. Nine non-correlated bioclimatic and four topographic data layers were used as niche components using GARP in OpenModeller. Both B2 and A2 climate change scenarios were used with two general circulation models for each scenario (CSIRO and HadCM3, for 2020, 2050 and 2080. There was an increase in niche breadth to 2080 in both scenarios for all species with the exception of Lutzomyia vexator. The principal direction of niche centroid displacement was to the northwest (64%, while the elevation range decreased greatest for tropical, and least for broad-range species. Lutzomyia cruciata is the only epidemiologically important species with high niche identity with that of Leishmania spp. in Mexico. Continued landscape modification in future climate change will provide an increased opportunity for the geographic expansion of NCA sand flys' ENM and human exposure to vectors of Leishmaniases.

  11. Current and Future Niche of North and Central American Sand Flies (Diptera: Psychodidae) in Climate Change Scenarios

    Science.gov (United States)

    Moo-Llanes, David; Ibarra-Cerdeña, Carlos N.; Rebollar-Téllez, Eduardo A.; Ibáñez-Bernal, Sergio; González, Camila; Ramsey, Janine M.

    2013-01-01

    Ecological niche models are useful tools to infer potential spatial and temporal distributions in vector species and to measure epidemiological risk for infectious diseases such as the Leishmaniases. The ecological niche of 28 North and Central American sand fly species, including those with epidemiological relevance, can be used to analyze the vector's ecology and its association with transmission risk, and plan integrated regional vector surveillance and control programs. In this study, we model the environmental requirements of the principal North and Central American phlebotomine species and analyze three niche characteristics over future climate change scenarios: i) potential change in niche breadth, ii) direction and magnitude of niche centroid shifts, iii) shifts in elevation range. Niche identity between confirmed or incriminated Leishmania vector sand flies in Mexico, and human cases were analyzed. Niche models were constructed using sand fly occurrence datapoints from Canada, USA, Mexico, Guatemala and Belize. Nine non-correlated bioclimatic and four topographic data layers were used as niche components using GARP in OpenModeller. Both B2 and A2 climate change scenarios were used with two general circulation models for each scenario (CSIRO and HadCM3), for 2020, 2050 and 2080. There was an increase in niche breadth to 2080 in both scenarios for all species with the exception of Lutzomyia vexator. The principal direction of niche centroid displacement was to the northwest (64%), while the elevation range decreased greatest for tropical, and least for broad-range species. Lutzomyia cruciata is the only epidemiologically important species with high niche identity with that of Leishmania spp. in Mexico. Continued landscape modification in future climate change will provide an increased opportunity for the geographic expansion of NCA sand flys' ENM and human exposure to vectors of Leishmaniases. PMID:24069478

  12. Infectivity and sporulation potential of Phytophthora kernoviae to select North American native plants

    Science.gov (United States)

    E. J. Fichtner; D. M. Rizzo; S. A. Kirk; J. F. Webber

    2011-01-01

    Phytophthora kernoviae exhibits comparable epidemiology to Phytophthora ramorum in invaded UK woodlands. Because both pathogens have an overlapping geographic range in the UK and often concurrently invade the same site, it is speculated that P. kernoviae may also invade North American (NA) forests...

  13. Host ranges of North American isolates of Penicillium causing blue mold of bulb crops

    Science.gov (United States)

    Single isolates of four Penicillium species belonging to series Corymbifera (Penicillium allii, P. hirsutum, P. tulipae, P. venetum) plus an isolate of P. polonicum, all from North American sources, were inoculated individually into Crocus sativus, Allium sativum (garlic), A. cepa (onion), Iris holl...

  14. Fire-induced wounding elicits changes in the wood anatomy of North American conifers

    Science.gov (United States)

    Estelle Arbellay; Markus Stoffel; Elaine K. Sutherland; Kevin T. Smith; Donald A. Falk

    2013-01-01

    Fire is a major disturbance agent in North American forests. Fires injure trees when heat transfer through the bark partially kills the cambium and the compartmentalization process results in a fire scar. Dendrochronologists use these scars in the xylem to reconstruct fire regimes. However, little information exists on the wood anatomy of fire scars. Consequently, this...

  15. Strategies for North American Missionaries' Relational Language-Culture Learning in the Japanese Context

    Science.gov (United States)

    Manabe-Kim, Rie

    2012-01-01

    This study focused on presenting the fieldwork findings derived from studying North-American missionaries' relational dynamics with the Japanese people, and the strategies that impacted their language-culture learning. This study also focused on applying the fieldwork findings towards the creation of a coaching model designed to help missionaries…

  16. Previsual detection of two conifer-infesting adelgid species in North American forest

    Science.gov (United States)

    Stephen Cook; Karen Humes; Ryan Hruska; Christopher Williams; Grant Fraley

    2010-01-01

    The balsam woolly adelgid, Adelges piceae, and hemlock woolly adelgid, A. tsugae (Homoptera: Adelgidae), are invasive pests of coniferous forests in both the Eastern and Western United States. Balsam woolly adelgid is capable of attacking and killing native North American firs, with Fraser fir (Abies fraseri...

  17. Extended duration of parturition season in North American elk (Cervus elaphus)

    Science.gov (United States)

    Barbara J. Keller; Amy D. Bleisch; Joshua J. Millspaugh; Chad P. Lehman; Jackie J. Kragel; Lonnie P. Hansen; Jason Sumners; Mark A. Rumble; Gary C. Brundige

    2015-01-01

    The timing of births in ungulates has significant implications for juvenile survival and population growth. For North American elk (Cervus elaphus), typical parturition season ranges from late May to early Jun., and juveniles born outside of this peak characteristically exhibit lowered survival. We observed abnormally long parturition seasons in free-ranging elk...

  18. Male sleep duration and fecundability in a North American preconception cohort study

    DEFF Research Database (Denmark)

    Wise, Lauren Anne; Rothman, Kenneth Jay; Wesselink, Amelia Kent

    2018-01-01

    OBJECTIVE: To evaluate prospectively the association between male sleep duration and fecundability. DESIGN: Pregnancy Online Study (PRESTO), a Web-based prospective cohort study of North American couples enrolled during the preconception period (2013-2017). SETTING: Not applicable. PATIENT(S): Male...

  19. Motivations of North American Tourists from Cruisers to Visit Cultural-Historical Destination (Dubrovnik/Croatia

    Directory of Open Access Journals (Sweden)

    Aleksandar Radic

    2016-01-01

    Full Text Available Purpose –The key to understanding motivation of tourists from cruisers who are visiting Dubrovnik is to understand their needs and wants for consuming history and culture as tourism products. The purpose of this paper is to assess the motivations of North American tourists visiting Dubrovnik on their cruises around the Mediterranean. Design/Methods/Approach – In this paper, the author decided to use two paradigms: pragmatism and positivism, which are usually followed by quantitative techniques of data collection. A structured questionnaire enabled author to collect quantitative data that were processed by descriptive statistics. Findings – The paper introduces new perspective on motivations of North American tourists who visit Dubrovnik on their cruises around the Mediterranean. The findings indicated that Cultural component was the most important dimension perceived by North American tourist, for choosing cruises with Dubrovnik as one of port of calls on their itinerary. Research limitations – Main limitations of this research paper were relatively small sample size and participants from only one Cruise Company. Originality – The article depicts motivation of North American tourists from cruise ships that choose to visit cultural-historical destination (Dubrovnik.

  20. The North-American Long-Term Soil Productivity Study: Concepts and literature

    Science.gov (United States)

    Deborah S. Page-Dumroese

    2010-01-01

    The resiliency of forest sites after a pulse disturbance is one of the key questions mandated by the National Forest Management Act (NFMA) of 1976. This Act mandated that we maintain the productive capacity of federally managed stands. The original USDA Forest Service soil quality standards were based largely on professional judgment. The North American Long-Term Soil...

  1. North American oriented strand board markets, arbitrage activity, and market price dynamics: A smooth transition approach

    Science.gov (United States)

    Barry Goodwin; Matthew Holt; Jeffrey P. Prestemon

    2011-01-01

    Price dynamics for North American oriented strand board markets are examined. The role of transactions costs are explored vis-à-vis the law of one price. Nonlinearities induced by unobservable transactions costs are modeled by estimating time-varying smooth transition autoregressions (TV-STARs). Results indicate that nonlinearity and structural change are important...

  2. 78 FR 18252 - Prevailing Rate Systems; North American Industry Classification System Based Federal Wage System...

    Science.gov (United States)

    2013-03-26

    ...-AM78 Prevailing Rate Systems; North American Industry Classification System Based Federal Wage System... applicable sections. The Federal Prevailing Rate Advisory Committee, the national labor- management committee... proposing to amend 5 CFR part 532 as follows: PART 532--PREVAILING RATE SYSTEMS 0 1. The authority citation...

  3. The impact of new product introduction on plant productivity in the North American automotive industry

    NARCIS (Netherlands)

    Gopal, A.; Goyal, M.; Netessine, S.; Reindorp, M.J.

    2013-01-01

    Product launch—an event when a new product debuts for production in a plant—is an important phase in product development. But launches disrupt manufacturing operations, resulting in productivity losses. Using data from North American automotive plants from years 1999–2007, we estimate that a product

  4. Transition problems in economic reform: agriculture in the North American free trade agreement

    NARCIS (Netherlands)

    van Wijnbergen, S.J.G.

    1995-01-01

    Investigates the effecto of the North American Free Trade Agreement on agriculture in Mexico. Implications on policy design for the absence of efficient capital markets, on the welfare costs of reforming gradually, on incentive problems created by trade adjustement policies and on the redistribution

  5. 78 FR 36571 - North American Datum of 1983 (NAD 83) Outer Continental Shelf (OCS) Provisional Official...

    Science.gov (United States)

    2013-06-18

    ... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management [MMAA104000] North American Datum of 1983 (NAD 83) Outer Continental Shelf (OCS) Provisional Official Protraction Diagram (OPDs) AGENCY... OPDs. SUMMARY: Notice is hereby given that effective with this publication two NAD 83-based OCS...

  6. 75 FR 55798 - North American Bioproducts Corporation; Filing of Food Additive Petition (Animal Use); Penicillin...

    Science.gov (United States)

    2010-09-14

    ...] North American Bioproducts Corporation; Filing of Food Additive Petition (Animal Use); Penicillin G... food additive regulations be amended to provide for the safe use of penicillin G procaine as an... Water of Animals (21 CFR part 573) to provide for the safe use of penicillin G procaine as an...

  7. Amplification of North American Red Oak Microsatellite Markers in European White Oaks and Chinese Chestnut

    Science.gov (United States)

    P. R. Aldrich; M. Jagtap; C. H. Michler; J. Romero-Severson

    2003-01-01

    We examined the cross-species amplification success of thirty microsatellite markers developed from North American northern red oak (Quercus rubra) in other members of the family Fagaceae. Sixteen of these markers are newly developed and we report primer sequences and amplification conditions here. Twelve of the thirty (40.0%) red oak markers...

  8. Life-history strategies of North American elk: trade-offs associated with reproduction and survival

    Science.gov (United States)

    Sabrina Morano; Kelley M. Stewart; James S. Sedinger; Christopher A. Nicolai; Marty Vavra

    2013-01-01

    The principle of energy allocation states that individuals should attempt to maximize fitness by allocating resources optimally among growth, maintenance, and reproduction. Such allocation may result in trade-offs between survival and reproduction, or between current and future reproduction. We used a marked population of North American elk (Cervus elaphus...

  9. 77 FR 59986 - Johnson Controls Including Workers Whose Wages Were Reported Under IMECO LLC; North American...

    Science.gov (United States)

    2012-10-01

    ... applicable to workers and former workers of Johnson Controls, North American Refrigeration, Dixon, Illinois... to TA-W-71,663 is hereby issued as follows: All workers of Johnson Controls, including workers whose... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-71,663] Johnson Controls...

  10. 77 FR 74174 - North American Free Trade Agreement (NAFTA), Article 1904 Binational Panel Reviews

    Science.gov (United States)

    2012-12-13

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free Trade Agreement (NAFTA), Article 1904 Binational Panel Reviews AGENCY: NAFTA Secretariat, United States Section.... Therefore, on the basis of the Panel Order and Rule 80 of the Article 1904 Panel Rules, the Panel Review was...

  11. 78 FR 5778 - North American Free Trade Agreement (NAFTA), Article 1904 Binational Panel Reviews

    Science.gov (United States)

    2013-01-28

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free Trade Agreement (NAFTA), Article 1904 Binational Panel Reviews AGENCY: NAFTA Secretariat, United States Section... the Panel Order and Rule 80 of the Article 1904 Panel Rules, the Panel Review was completed and the...

  12. 78 FR 17639 - North American Free Trade Agreement (NAFTA), Article 1904 Binational Panel Reviews

    Science.gov (United States)

    2013-03-22

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free Trade Agreement (NAFTA), Article 1904 Binational Panel Reviews AGENCY: NAFTA Secretariat, United States Section... Order and Rule 80 of the Article 1904 Panel Rules, the Panel Review was completed and the panelists were...

  13. 78 FR 10600 - North American Free Trade Agreement (NAFTA), Article 1904 Binational Panel Reviews

    Science.gov (United States)

    2013-02-14

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free Trade Agreement (NAFTA), Article 1904 Binational Panel Reviews AGENCY: NAFTA Secretariat, United States Section... Order and Rule 80 of the Article 1904 Panel Rules, the Panel Review was completed and the panelists were...

  14. 78 FR 11627 - North American Free Trade Agreement (NAFTA), Article 1904 Binational Panel Reviews

    Science.gov (United States)

    2013-02-19

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free Trade Agreement (NAFTA), Article 1904 Binational Panel Reviews AGENCY: NAFTA Secretariat, United States Section... Order and Rule 80 of the Article 1904 Panel Rules, the Panel Review was completed and the panelists were...

  15. 77 FR 72325 - North American Free Trade Agreement (NAFTA), Article 1904 Binational Panel Reviews

    Science.gov (United States)

    2012-12-05

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free Trade Agreement (NAFTA), Article 1904 Binational Panel Reviews AGENCY: NAFTA Secretariat, United States Section... Order and Rule 80 of the Article 1904 Panel Rules, the Panel Review was completed and the panelists were...

  16. United States versus Mexican Perceptions of the Impact of the North American Free Trade Agreement.

    Science.gov (United States)

    Nicholson, Joel D.; And Others

    1994-01-01

    Surveys U.S. and Mexican managerial attitudes concerning the impact of the North American Free Trade Agreement (NAFTA) process on the United States. Discusses differences in Mexican and U.S. attitudes concerning NAFTA and a number of socioeconomic concerns. (SR)

  17. Commercial Trucking: Safety and Infrastructure Issues Under the North American Free Trade Agreement

    Science.gov (United States)

    1996-02-29

    The North American Free Trade Agreement (NAFTA) provided for the U.S.-Mexican border to be opened for increased commercial truck traffic within the respective border states-four in the United States (Arizona, California, New Mexico, and Texas) and si...

  18. Batrachochytrium salamandrivorans: The North American response and a call for action

    Science.gov (United States)

    Matthew J. Gray; James P. Lewis; Priya Nanjappa; Blake Klocke; Frank Pasmans; An Martel; Craig Stephen; Gabriela Parra Olea; Scott A. Smith; Allison Sacerdote-Velat; Michelle R. Christman; Jennifer M. Williams; Deanna H. Olson; Deborah A. Hogan

    2015-01-01

    Batrachochytrium salamandrivorans (Bsal) is an emerging fungal pathogen that has caused recent die-offs of native salamanders in Europe and is known to be lethal to at least some North American species in laboratory trials [1]. Bsal appears to have originated in Asia, and may have been introduced by humans...

  19. Density-dependent effects on physical condition and reproduction in North American elk: an experimental test.

    Science.gov (United States)

    Kelley M. Stewart; R. Terry Bowyer; Brian L. Dick; Bruce K. Johnson; John G. Kie

    2005-01-01

    Density dependence plays a key role in life-history characteristics and population ecology of large, herbivorous mammals. We designed a manipulative experiment to test hypotheses relating effects of density-dependent mechanisms on physical condition and fecundity of North American elk (Cervus elaphus) by creating populations at low and high density...

  20. 76 FR 66130 - Mazda North American Operations, Grant of Petition for Decision of Inconsequential Noncompliance

    Science.gov (United States)

    2011-10-25

    ... Mazda Motor Corporation of Hiroshima, Japan (Mazda), has determined the lens of the headlamps equipped... December 16, 2009. \\1\\ Mazda Motor Corporation of Hiroshima, Japan (Mazda) is the manufacturer of the...-0141; Notice 2] Mazda North American Operations, Grant of Petition for Decision of Inconsequential...

  1. 75 FR 65053 - Mazda North American Operations, Receipt of Petition for Decision of Inconsequential Noncompliance

    Science.gov (United States)

    2010-10-21

    ... Noncompliance Mazda North American Operations (MNAO),\\1\\ on behalf of Mazda Motor Corporation of Hiroshima..., Defect and Noncompliance Responsibility and Reports, dated December 18, 2009. \\1\\ Mazda Motor Corporation... noncompliance is inconsequential to motor vehicle safety. This notice of receipt of Mazda's petition is...

  2. 78 FR 20137 - Probable Economic Effect of Certain Modifications to the North American Free Trade Agreement...

    Science.gov (United States)

    2013-04-03

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. TA-103-027] Probable Economic Effect of Certain... investigation No. TA-103-027, Probable Economic Effect of Certain Modifications to the North American Free Trade... reached agreement in principle with representatives of the governments of Canada and Mexico on proposed...

  3. North American Wood Waste Forum: Summary of Group Feedback, 2-3, 2012

    Science.gov (United States)

    Bob Falk

    2012-01-01

    This report summarizes the feedback and recommendations of the North American Wood Recovery Group. This report summarizes the barriers and opportunities in wood recovery, reuse, and recycling as identified by this group of stakeholders from the wood industry, waste industry, and relevant government agencies.

  4. Managing Regional Collaboration in Higher Education: The Case of the North American Free Trade Agreement (NAFTA).

    Science.gov (United States)

    Crespo, Manuel

    2000-01-01

    Describes accomplishments in increasing collaboration in higher education within the North American Free Trade Agreement (NAFTA). Analyzes procedures for determining equivalencies of courses and degrees and for improving transnational mobility of students and professors. Also discusses the role of the private sector in research, education and…

  5. Contemporary North American influenza H7 viruses possess human receptor specificity: Implications for virus transmissibility

    DEFF Research Database (Denmark)

    Belser, Jessica A; Blixt, Ola; Chen, Li-Mei

    2008-01-01

    Avian H7 influenza viruses from both the Eurasian and North American lineage have caused outbreaks in poultry since 2002, with confirmed human infection occurring during outbreaks in The Netherlands, British Columbia, and the United Kingdom. The majority of H7 infections have resulted in self-lim...

  6. Strategies for Success: Open Access Policies at North American Educational Institutions

    Science.gov (United States)

    Fruin, Christine; Sutton, Shan

    2016-01-01

    Recognizing the paucity of quantitative and qualitative data from North American educational institutions that have pursued open access policies, the authors devised a survey to collect information on the characteristics of these institutions, as well as the elements of the open access policies, the methods of promoting these policies, faculty…

  7. North American pollution measurements from geostationary orbit with Tropospheric Emissions: Monitoring of Pollution (TEMPO)

    Science.gov (United States)

    Chance, K.

    2017-12-01

    TEMPO is the first NASA Earth Venture Instrument. It launches between 2019 and 2021 to measure atmospheric pollution from Mexico City and Cuba to the Canadian oil sands, and from the Atlantic to the Pacific, hourly at high spatial resolution, 10 km2. Geostationary daytime measurements capture the variability in the diurnal cycle of emissions and chemistry at sub-urban scale to improve emission inventories, monitor population exposure, and enable emission-control strategies.TEMPO measures UV/visible Earth reflectance spectra to retrieve O3, NO2, SO2, H2CO, C2H2O2, H2O, BrO, OClO, IO, aerosols, cloud parameters, and UVB radiation. It tracks aerosol loading. It provides near-real-time air quality products. TEMPO is the North American component of the upcoming the global geostationary constellation for pollution monitoring, together with the European Sentinel-4 and the Korean Geostationary Environmental Monitoring Spectrometer (GEMS).TEMPO science studies include: Intercontinental pollution transport; Solar-induced fluorescence from chlorophyll over land and in the ocean to study tropical dynamics, primary productivity and carbon uptake, to detect red tides, and to study phytoplankton; measurements of stratospheric intrusions that cause air quality exceedances; measurements at peaks in vehicle travel to capture the variability in emissions from mobile sources; measurements of thunderstorm activity, including outflow regions to better quantify lightning NOx and O3 production; cropland measurements to follow the temporal evolution of emissions after fertilizer application and from rain-induced emissions from semi-arid soils; investigating the chemical processing of primary fire emissions and the secondary formation of VOCs and ozone; examining ocean halogen emissions and their impact on the oxidizing capacity of coastal environments; measuring spectra of nighttime lights as markers for human activity, energy conservation, and compliance with outdoor lighting standards

  8. Widespread triploidy in Western North American aspen (Populus tremuloides.

    Directory of Open Access Journals (Sweden)

    Karen E Mock

    Full Text Available We document high rates of triploidy in aspen (Populus tremuloides across the western USA (up to 69% of genets, and ask whether the incidence of triploidy across the species range corresponds with latitude, glacial history (as has been documented in other species, climate, or regional variance in clone size. Using a combination of microsatellite genotyping, flow cytometry, and cytology, we demonstrate that triploidy is highest in unglaciated, drought-prone regions of North America, where the largest clone sizes have been reported for this species. While we cannot completely rule out a low incidence of undetected aneuploidy, tetraploidy or duplicated loci, our evidence suggests that these phenomena are unlikely to be significant contributors to our observed patterns. We suggest that the distribution of triploid aspen is due to a positive synergy between triploidy and ecological factors driving clonality. Although triploids are expected to have low fertility, they are hypothesized to be an evolutionary link to sexual tetraploidy. Thus, interactions between clonality and polyploidy may be a broadly important component of geographic speciation patterns in perennial plants. Further, cytotypes are expected to show physiological and structural differences which may influence susceptibility to ecological factors such as drought, and we suggest that cytotype may be a significant and previously overlooked factor in recent patterns of high aspen mortality in the southwestern portion of the species range. Finally, triploidy should be carefully considered as a source of variance in genomic and ecological studies of aspen, particularly in western U.S. landscapes.

  9. Surficial origin of North American pitchblende and related uranium deposits

    International Nuclear Information System (INIS)

    Langford, F.F.

    1977-01-01

    The ubiquitous association of pitchblende uranium deposits with terrestrial sediments is believed to be the natural result of formation of the orebodies by surficial processes operating under continental conditions. The major uranium deposits of North America illustrate this. The quartz-pebble conglomerate uranium deposits of Elliot Lake, Ontario, have thorium-rich uranium minerals that indicate a detrital origin. With the development of an oxygenic atmosphere before 1,700 m.y. ago, uranium was transported in solution in meteoric surface and near-surface ground water, and produced pitchblende veins in fractures in the basement and in lava flows in terrestrial environments. This accounts for the closee association of fluvial sediments with the pitchblende deposits at Beaverlodge, Rabbit Lake, Baker Lake, and Great Bear Lake, Canada. The development of land plants about 300 m.y. ago produced favorable environments within the terrestrial sandstones themselves, and resulted in the tabular uranium orebodies of the Colorado Plateau. The close relation of tabular orebodies to sedimentation is apparent when compared to recent fluvial sedimentation. In Wyoming, the stratigraphic restriction of the boundary-roll deposits to a few zones in Eocene rocks results from their being remobilized tabular deposits

  10. Strengthening Canada's position in the North American natural gas market

    International Nuclear Information System (INIS)

    2001-09-01

    The Canadian Gas Association (CGA) is the industry organization that represents the Canadian natural gas and energy delivery industry. It is on the frontline of consumer perceptions regarding natural gas, which is the fuel of choice for Canadian homeowners. Canadian consumers have benefitted from the deregulation initiatives of the mid-1980s which provided significant growth opportunities. Given the tumultuous energy environment throughout North America, the CGA believes that a national energy strategy should be developed to address future supply issues and also to examine ways to ensure that extreme market shifts are anticipated and mitigated as much as possible. The CGA is ready to provide governments with input for such a strategy representing the perspective of the Canadian consumer. The CGA recommends that the Government of Canada, the provinces and territories adopt the following initiatives regarding the use of natural gas: (1) recognize and promote the environmental qualities and applications of natural gas, (2) encourage competition, (3) promote transparent and consistent approach to regulation, (4) reaffirm commitment to market-based policies, (5) facilitate economic research, analysis and communication about trends in the natural gas market, and (6) promote the development of new technologies that expand the uses of natural gas and support research in infrastructure development. The government's actions in the areas proposed in this report will contribute to advancing Canada's environmental objectives and economic growth. 2 figs

  11. The end game: Mortality outcomes in North American professional athletes.

    Science.gov (United States)

    Lemez, S; Wattie, N; Baker, J

    2018-06-01

    Comprehensive investigations into the mortality outcomes of elite athletes can assist in decoding risk factors for premature mortality and provide avenues for exploring human health through engagement in sport. As such, the purpose of this study was to comprehensively examine lifespan trends of athletes from the 4 major sports in North America: Major League Baseball (MLB), National Basketball Association (NBA), National Football League (NFL), and National Hockey League (NHL). We hypothesized that proportional death rates would be similar across the 4 sports, when standardizing the data by debut years. Overall, 17 523 of 50 515 (34.7%) athletes were deceased as of the respective data collection cutoff date for their sport, with MLB players having the highest risk of imminent mortality. Professional basketball players generally had the highest relative proportion of death when standardizing data by debut year, although NHL and NFL players who debuted after 2005 had the highest proportion of death. In addition, a 1-year increase in career length significantly decreased the risk of death (HR: 0.982, 95% CI: 0.978-0.985), even after adjusting for sport type (HR: 0.977, 95% CI: 0.974-0.980). Meaningful significance should be considered given the historical and unique nature of the sample. Nevertheless, investigating risk of death differences through different occupational and biological variables can help highlight aversive trends to lifespan that permeate throughout high-performance athlete populations. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Ethics education in chiropractic colleges: a North American survey.

    Science.gov (United States)

    Kinsinger, Stuart; Soave, David

    2012-07-01

    The purposes of this study were to survey Council on Chiropractic Education-accredited chiropractic colleges in North America and to describe curricular details on the teaching of bioethics. A custom-designed survey was sent to chiropractic colleges. Total number of contact hours, whether the ethics was a stand-alone course or integrated elsewhere, type of instructor, and if there was a required or recommended course text were queried. Of 19 surveys sent by mail, 15 surveys were returned. The average time in ethics instruction was 18.7 hours including lecture format, small group tutorial, and self-study. Chiropractic ethics education includes 8 areas of content (boundaries, law and jurisprudence, professionalism, basic ethic tenets/principles, ethical codes of conduct, prevention of financial and of sexual abuse, and resolving an ethical dilemma). Some colleges include content taught to students under the domain of law and jurisprudence. The results of this survey indicate that there are opportunities to further develop the educational ethics program at Council on Chiropractic Education-accredited colleges. All colleges currently offer bioethics teaching. An expanded role for this content is recommended so as to offer optimal benefit for students and practitioners. Copyright © 2012 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

  13. The occurrence of blood protozoa in North American birds

    Science.gov (United States)

    Herman, C.M.

    1957-01-01

    This report is based on review of literature and examination of a great number of blood smears from native birds in North America, particularly Passeriformes and Anseriformes. Haemoproteus and Leucocytozoon occur most frequently, although various species of Plasmodium and, occasionally, other less known forms are recognized. Prevalence of these parasites in wild birds is related to season of year and age of host. Highest incidence occurs in spring and summer. Relapse of Haemoproteus and Leucocytozoon is common in the spring. Blood smears of adult wood ducks, on the Atlantic flyway, in April and May show a high prevalence of Haemoproteus, while smears at other times are usually negative. Although the author (Herman, 1938) demonstrated that young redwings in Massachusetts primarily acquired Plasmodium infections after leaving the nest, in many cases infection is acquired by the nestling. Nestling magpies in northeastern California acquire a high incidence of infection with several parasites. The hypothesis, expressed by Manwell and Herman (1935), that a higher prevalence of infection can be expected in more southerly ranging species, is subject to question. Smears taken during the winter demonstrate higher parasite prevalence in birds at the southern limits of their range, such as juncos and white-throated sparrows, than do smears of other species with more southern range. Little is known of significance of these parasites to survival of the host, although O'Roke ( 1934) reported a high loss for ducklings from Leucocytozoon and there have been occasional reports of fatality in other species.

  14. North American Soil Degradation: Processes, Practices, and Mitigating Strategies

    Directory of Open Access Journals (Sweden)

    R. L. Baumhardt

    2015-03-01

    Full Text Available Soil can be degraded by several natural or human-mediated processes, including wind, water, or tillage erosion, and formation of undesirable physical, chemical, or biological properties due to industrialization or use of inappropriate farming practices. Soil degradation occurs whenever these processes supersede natural soil regeneration and, generally, reflects unsustainable resource management that is global in scope and compromises world food security. In North America, soil degradation preceded the catastrophic wind erosion associated with the dust bowl during the 1930s, but that event provided the impetus to improve management of soils degraded by both wind and water erosion. Chemical degradation due to site specific industrial processing and mine spoil contamination began to be addressed during the latter half of the 20th century primarily through point-source water quality concerns, but soil chemical degradation and contamination of surface and subsurface water due to on-farm non-point pesticide and nutrient management practices generally remains unresolved. Remediation or prevention of soil degradation requires integrated management solutions that, for agricultural soils, include using cover crops or crop residue management to reduce raindrop impact, maintain higher infiltration rates, increase soil water storage, and ultimately increase crop production. By increasing plant biomass, and potentially soil organic carbon (SOC concentrations, soil degradation can be mitigated by stabilizing soil aggregates, improving soil structure, enhancing air and water exchange, increasing nutrient cycling, and promoting greater soil biological activity.

  15. Modulating Effects of Mesoscale Oceanic Eddies on Sea Surface Temperature Response to Tropical Cyclones Over the Western North Pacific

    Science.gov (United States)

    Ma, Zhanhong; Fei, Jianfang; Huang, Xiaogang; Cheng, Xiaoping

    2018-01-01

    The impact of mesoscale oceanic eddies on the temporal and spatial characteristics of sea surface temperature (SST) response to tropical cyclones is investigated in this study based on composite analysis of cyclone-eddy interactions over the western North Pacific. The occurrence times of maximum cooling, recovery time, and spatial patterns of SST response are specially evaluated. The influence of cold-core eddies (CCEs) renders the mean occurrence time of maximum SST cooling to become about half a day longer than that in eddy-free condition, while warm-core eddies (WCEs) have little effect on this facet. The recovery time of SST cooling also takes longer in presence of CCEs, being overall more pronounced for stronger or slower tropical cyclones. The effect of WCEs on the recovery time is again not significant. The modulation of maximum SST decrease by WCEs for category 2-5 storms is found to be remarkable in the subtropical region but not evident in the tropical region, while the role of CCEs is remarkable in both regions. The CCEs are observed to change the spatial characteristics of SST response, with enhanced SST decrease initially at the right side of storm track. During the recovery period the strengthened SST cooling by CCEs propagates leftward gradually, with a feature similar as both the westward-propagating eddies and the recovery of cold wake. These results underscore the importance of resolving mesoscale oceanic eddies in coupled numerical models to improve the prediction of storm-induced SST response.

  16. Relationships among North American and Japanese Laetiporus isolates inferred from molecular phylogenetics and single-spore incompatibility reactions

    Science.gov (United States)

    Mark T. Banik; Daniel L. Lindner; Yuko Ota; Tsutomu Hattori

    2010-01-01

    Relationships were investigated among North American and Japanese isolates of Laetiporus using phylogenetic analysis of ITS sequences and single-spore isolate incompatibility. Single-spore isolate pairings revealed no significant compatibility between North American and Japanese isolates. ITS analysis revealed 12 clades within the core ...

  17. Advances toward DNA-based identification and phylogeny of North American Armillaria species using elongation factor-1 alpha gene

    Science.gov (United States)

    Amy L. Ross-Davis; John W. Hanna; Mee-Sook Kim; Ned B. Klopfenstein

    2012-01-01

    The translation elongation factor-1 alpha gene was used to examine the phylogenetic relationships among 30 previously characterized isolates representing ten North American Armillaria species: A. solidipes (=A. ostoyae), A. gemina, A. calvescens, A. sinapina, A. mellea, A. gallica, A. nabsnona, North American biological species X, A. cepistipes, and A. tabescens. The...

  18. Thermal load histories for North American roof assembles using various cladding materials including wood-thermoplastic composite shingles

    Science.gov (United States)

    J. E. Winandy

    2006-01-01

    Since 1991, thermal load histories for various roof cladding types have been monitored in outdoor attic structures that simulate classic North American light-framed construction. In this paper, the 2005 thermal loads for wood-based composite roof sheathing, wood rafters, and attics under wood-plastic composite shingles are compared to common North American roof...

  19. 18 CFR 38.2 - Incorporation by reference of North American Energy Standards Board Wholesale Electric Quadrant...

    Science.gov (United States)

    2010-04-01

    ... reference of North American Energy Standards Board Wholesale Electric Quadrant standards. 38.2 Section 38.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY... UTILITIES § 38.2 Incorporation by reference of North American Energy Standards Board Wholesale Electric...

  20. Work Ethic, Motivation, and Parental Influences in Chinese and North American Children Learning to Play the Piano

    Science.gov (United States)

    Comeau, Gilles; Huta, Veronika; Liu, YiFei

    2015-01-01

    This study compared 50 Chinese and 100 North American Caucasian children aged 6 to 17 who were learning piano, in terms of their work ethic, motivation, and parental influences. Compared to North American Caucasians, Chinese children and parents believed more strongly that musical ability requires hard work, and Chinese children were more…

  1. 77 FR 72325 - North American Free-Trade Agreement, Article 1904 NAFTA Panel Reviews; Request for Panel Review

    Science.gov (United States)

    2012-12-05

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free-Trade Agreement... Free Trade Agreement. Panel Review was requested of the Final resolution of the Countervailing Duty... 19 of the North American Free-Trade Agreement (``Agreement'') established a mechanism to replace...

  2. 75 FR 13494 - North American Free-Trade Agreement, Article 1904; NAFTA Panel Reviews; Request for Panel Review

    Science.gov (United States)

    2010-03-22

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free-Trade Agreement... Secretariat pursuant to Article 1904 of the North American Free Trade Agreement. Panel Review was requested of... Section, International Trade Administration, Department of Commerce. ACTION: Notice of First Request for...

  3. 77 FR 66798 - North American Free-Trade Agreement, Article 1904; NAFTA Panel Reviews; Request for Panel Review

    Science.gov (United States)

    2012-11-07

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free-Trade Agreement... Trade Agreement. Panel Review was requested of the Final Results of the Antidumping Administrative... INFORMATION: Chapter 19 of the North American Free-Trade Agreement (``Agreement'') established a mechanism to...

  4. 76 FR 42115 - North American Free-Trade Agreement, Article 1904 NAFTA Panel Reviews; Request for Panel Review

    Science.gov (United States)

    2011-07-18

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free-Trade Agreement... Free Trade Agreement. Panel Review was requested of the Final Results of the 2008- 2009 and 2009-2010.... SUPPLEMENTARY INFORMATION: Chapter 19 of the North American Free Trade Agreement (``Agreement'') established a...

  5. 76 FR 72677 - North American Free-Trade Agreement, Article 1904 NAFTA Panel Reviews; Request for Panel Review

    Science.gov (United States)

    2011-11-25

    ... DEPARTMENT OF COMMERCE International Trade Administration North American Free-Trade Agreement... Trade Agreement. Panel review was requested of the final determination of the effective examination and... 20230, (202) 482-5438. SUPPLEMENTARY INFORMATION: Chapter 19 of the North American Free-Trade Agreement...

  6. How might the North American ice sheet influence the northwestern Eurasian climate?

    Science.gov (United States)

    Beghin, P.; Charbit, S.; Dumas, C.; Kageyama, M.; Ritz, C.

    2015-10-01

    It is now widely acknowledged that past Northern Hemisphere ice sheets covering Canada and northern Europe at the Last Glacial Maximum (LGM) exerted a strong influence on climate by causing changes in atmospheric and oceanic circulations. In turn, these changes may have impacted the development of the ice sheets themselves through a combination of different feedback mechanisms. The present study is designed to investigate the potential impact of the North American ice sheet on the surface mass balance (SMB) of the Eurasian ice sheet driven by simulated changes in the past glacial atmospheric circulation. Using the LMDZ5 atmospheric circulation model, we carried out 12 experiments under constant LGM conditions for insolation, greenhouse gases and ocean. In these experiments, the Eurasian ice sheet is removed. The 12 experiments differ in the North American ice-sheet topography, ranging from a white and flat (present-day topography) ice sheet to a full-size LGM ice sheet. This experimental design allows the albedo and the topographic impacts of the North American ice sheet onto the climate to be disentangled. The results are compared to our baseline experiment where both the North American and the Eurasian ice sheets have been removed. In summer, the sole albedo effect of the American ice sheet modifies the pattern of planetary waves with respect to the no-ice-sheet case, resulting in a cooling of the northwestern Eurasian region. By contrast, the atmospheric circulation changes induced by the topography of the North American ice sheet lead to a strong decrease of this cooling. In winter, the Scandinavian and the Barents-Kara regions respond differently to the American ice-sheet albedo effect: in response to atmospheric circulation changes, Scandinavia becomes warmer and total precipitation is more abundant, whereas the Barents-Kara area becomes cooler with a decrease of convective processes, causing a decrease of total precipitation. The gradual increase of the

  7. Sex and cultural differences in spatial performance between Japanese and North Americans.

    Science.gov (United States)

    Sakamoto, Maiko; Spiers, Mary V

    2014-04-01

    Previous studies have suggested that Asians perform better than North Americans on spatial tasks but show smaller sex differences. In this study, we evaluated the relationship between long-term experience with a pictorial written language and spatial performance. It was hypothesized that native Japanese Kanji (a complex pictorial written language) educated adults would show smaller sex differences on spatial tasks than Japanese Americans or North Americans without Kanji education. A total of 80 young healthy participants (20 native Japanese speakers, 20 Japanese Americans-non Japanese speaking, and 40 North Americans-non Japanese speaking) completed the Rey Complex Figure Test (RCFT), the Mental Rotations Test (MRT), and customized 2D and 3D spatial object location memory tests. As predicted, main effects revealed men performed better on the MRT and RCFT and women performed better on the spatial object location memory tests. Also, as predicted, native Japanese performed better on all tests than the other groups. In contrast to the other groups, native Japanese showed a decreased magnitude of sex differences on aspects of the RCFT (immediate and delayed recall) and no significant sex difference on the efficiency of the strategy used to copy and encode the RCFT figure. This study lends support to the idea that intensive experience over time with a pictorial written language (i.e., Japanese Kanji) may contribute to increased spatial performance on some spatial tasks as well as diminish sex differences in performance on tasks that most resemble Kanji.

  8. Enhanced Influence of the Tropical Atlantic SST on the Western North Pacific Subtropical High after late 1970s

    Science.gov (United States)

    Hong, C. C.

    2015-12-01

    The western North Pacific subtropical high (WNPSH) in boreal summer shows a remarkable enhancement after the late 1970s. Whereas the sea surface temperature (SST) in the North Indian Ocean (NIO) and the equatorial eastern Pacific (EEP) had been noted to have remarkable local or remote effects on enhancing the WNPSH, the influence of the Atlantic SST, so far, is hardly explored. This article reports a new finding: enhanced relationship between the tropical Atlantic (TA)-SST and the WNPSH after the late 1970s. Regression study suggests that the warm TA-SST produced a zonally overturning circulation anomaly, with descending over the central equatorial Pacific and ascending over the tropical Atlantic/eastern Pacific. The anomalous descending over the central equatorial Pacific likely induced low-level anticyclonic anomaly to the west and therefore enhanced the WNPSH. One implication of this new finding is for predictability. The well-known "spring predictability barrier" (i.e., the influence of El Niño and Southern Oscillation (ENSO) falls dramatically during boreal spring) does not apply to the TA-SST/WNPSH relationship. Conversely, the TA-SST shows consistently high correlation starting from boreal spring when the ENSO influence continues declining. The TA-SST pushes the predictability of the WNPSH in boreal summer approximately one season earlier to boreal spring.

  9. North American Megadroughts in the Common Era: Reconstructions and Simulations

    Science.gov (United States)

    Cook, Benjamin I.; Cook, Edward R.; Smerdon, Jason E.; Seager, Richard; Williams, A. Park; Coats, Sloan; Stahle, David W.; Villanueva Diaz, Jose

    2016-01-01

    During the Medieval Climate Anomaly (MCA), Western North America experienced episodes of intense aridity that persisted for multiple decades or longer. These megadroughts are well documented in many proxy records, but the causal mechanisms are poorly understood. General circulation models (GCMs) simulate megadroughts, but do not reproduce the temporal clustering of events during the MCA, suggesting they are not caused by the time history of volcanic or solar forcing. Instead, GCMs generate megadroughts through (1) internal atmospheric variability, (2) sea-surface temperatures, and (3) land surface and dust aerosol feedbacks. While no hypothesis has been definitively rejected, and no GCM has accurately reproduced all features (e.g., timing, duration, and extent) of any specific megadrought, their persistence suggests a role for processes that impart memory to the climate system (land surface and ocean dynamics). Over the 21st century, GCMs project an increase in the risk of megadrought occurrence through greenhouse gas forced reductions in precipitation and increases in evaporative demand. This drying is robust across models and multiple drought indicators, but major uncertainties still need to be resolved. These include the potential moderation of vegetation evaporative losses at higher atmospheric [CO2], variations in land surface model complexity, and decadal to multidecadal modes of natural climate variability that could delay or advance onset of aridification over the the next several decades. Because future droughts will arise from both natural variability and greenhouse gas forced trends in hydroclimate, improving our understanding of the natural drivers of persistent multidecadal megadroughts should be a major research priority.

  10. Inland Waters and the North American Carbon Cycle

    Science.gov (United States)

    Butman, D. E.; Striegl, R. G.; Stackpoole, S. M.; del Giorgio, P.; Prairie, Y.; Pilcher, D.; Raymond, P. A.; Alcocer, J.; Paz, F.

    2016-12-01

    Inland aquatic ecosystems process, store, and release carbon to the atmosphere and coastal margins. The form of this carbon is a function of terrestrial and aquatic primary and secondary production, the weathering of materials in soils and subsurface environments, the hydrologic controls on the movement of carbon from land to inland waters, and the connectivity between streams, rivers, lakes, reservoirs and groundwater. The 2007 1st State of the Carbon Cycle reported fluxes for the continental United States (CONUS) only. Streams and rivers exported 30-40 Tg C yr-1 to coastal environments, and 17-25 Tg C yr-1 were buried in lake and reservoir sediments. Remarkably, the 2007 report did not quantify gas emissions, which represent over half of the total carbon fluxes through inland water in the US. Current research has shown that 71-149 Tg C yr-1 exits freshwater systems either through atmospheric emissions of carbon dioxide or as inorganic and organic carbon fluxes to the coast from the CONUS. These estimates did not include the Laurentian Great Lakes. Variation in the magnitude of these fluxes across regions of the CONUS has been linked to differences in precipitation and terrestrial net ecosystem production. Similar comprehensive assessments have not been done for Canada or Mexico. Here we provide, as part of the 2nd State of the Carbon Cycle report, estimates for the river coastal export and vertical emissions of carbon from inland waters of North America, and report major data gaps, and weaknesses in methodologies. These findings stress that strong international partnerships are needed to improve assessment, monitoring, and modeling of human impacts on the magnitude and timing of aquatic fluxes in the future.

  11. Age structure and disturbance legacy of North American forests

    Directory of Open Access Journals (Sweden)

    Y. Pan

    2011-03-01

    Full Text Available Most forests of the world are recovering from a past disturbance. It is well known that forest disturbances profoundly affect carbon stocks and fluxes in forest ecosystems, yet it has been a great challenge to assess disturbance impacts in estimates of forest carbon budgets. Net sequestration or loss of CO2 by forests after disturbance follows a predictable pattern with forest recovery. Forest age, which is related to time since disturbance, is a useful surrogate variable for analyses of the impact of disturbance on forest carbon. In this study, we compiled the first continental forest age map of North America by combining forest inventory data, historical fire data, optical satellite data and the dataset from NASA's Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS project. A companion map of the standard deviations for age estimates was developed for quantifying uncertainty. We discuss the significance of the disturbance legacy from the past, as represented by current forest age structure in different regions of the US and Canada, by analyzing the causes of disturbances from land management and nature over centuries and at various scales. We also show how such information can be used with inventory data for analyzing carbon management opportunities. By combining geographic information about forest age with estimated C dynamics by forest type, it is possible to conduct a simple but powerful analysis of the net CO2 uptake by forests, and the potential for increasing (or decreasing this rate as a result of direct human intervention in the disturbance/age status. Finally, we describe how the forest age data can be used in large-scale carbon modeling, both for land-based biogeochemistry models and atmosphere-based inversion models, in order to improve the spatial accuracy of carbon cycle simulations.

  12. Phylogeny and taxonomy of the North American clade of the Ceratocystis fimbriata complex.

    Science.gov (United States)

    Johnson, Jason A; Harrington, Thomas C; Engelbrecht, C J B

    2005-01-01

    Ceratocystis fimbriata is a widely distributed, plant pathogenic fungus that causes wilts and cankers on many woody hosts. Earlier phylogenetic analyses of DNA sequences revealed three geographic clades within the C. fimbriata complex that are centered respectively in North America, Latin America and Asia. This study looked for cryptic species within the North American clade. The internal transcribed spacer regions (ITS) of the rDNA were sequenced, and phylogenetic analysis indicated that most isolates from the North American clade group into four host-associated lineages, referred to as the aspen, hickory, oak and cherry lineages, which were isolated primarily from wounds or diseased trees of Populus, Carya, Quercus and Prunus, respectively. A single isolate collected from P. serotina in Wisconsin had a unique ITS sequence. Allozyme electromorphs also were highly polymorphic within the North American clade, and the inferred phylogenies from these data were congruent with the ITS-rDNA analyses. In pairing experiments isolates from the aspen, hickory, oak and cherry lineages were interfertile only with other isolates from their respective lineages. Inoculation experiments with isolates of the four host-associated groupings showed strong host specialization by isolates from the aspen and hickory lineages on Populus tremuloides and Carya illinoensis, respectively, but isolates from the oak and cherry lineages did not consistently reveal host specialization. Morphological features distinguish isolates in the North American clade from those of the Latin American clade (including C. fimbriata sensu stricto). Based on the phylogenetic evidence, interfertility, host specialization and morphology, the oak and cherry lineages are recognized as the earlier described C. variospora, the poplar lineage as C. populicola sp. nov., and the hickory lineage as C. caryae sp. nov. A new species associated with the bark beetle Scolytus quadrispinosus on Carya is closely related to C

  13. Comparison of the Topography of Carotid Territory Stenosis in North American and Iranian Stroke Patients

    Directory of Open Access Journals (Sweden)

    A Shoayb

    2007-01-01

    Full Text Available Introduction: Atherosclerotic stenosis of carotid territory is the most common cause of ischemic stroke. A higher frequency of intracranial arterial stenosis has been reported in Africa and the Far East. Methods: 304 geriatric ischemic stroke patients admitted in Mackenzie hospital, Canada and the same number of geriatric ischemic stroke patients with similar sex ratio admitted in Valie-Asr hospital, Iran during 2003-2005 were enrolled in a double center and prospective study. Diagnosis of brain infarction in the carotid territory was made by stroke neurologists. All of the patients underwent transcranial and carotid doppler studies. Doppler studies performed were based on the standard method by a neurosonologist. Fisher exact test served for statistical analysis and p<0.05 was declared significant. Results: In Iranian group 71 patients (23.3% and in North American group 83 patients (27.3% had extracranial ICA stenosis without a significant difference df=1, p=0.305. Sever ³70% Extracranial ICA stenosis was found in 14 Iranian patients (4.6% and 23 North American patients (7.5% without a significant difference. df=1, p=0.17. In Iranian group, 14 cases (4.6% and in North American group 5 cases (1.6% had intracranial stenosis in carotid territory which was significantly different df=1, p=0.038. Mixed intracranial and extracranial carotid territory stenosis was present in 2 Iranian and 1 North American patient. Conclusion: Atherosclerotic stenosis of intracranial branches of carotid territory is more common in Iranian than North American populations.

  14. 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.

  15. Soil Carbon in North American, Arctic, and Boreal Regions

    Science.gov (United States)

    Lajtha, K.; Bailey, V. L.; Schuur, E.; McGuire, D.; Romanovsky, V. E.

    2017-12-01

    Globally, soils contain more than 3 times as much as C as the atmosphere and >4 times more C than the world's biota, therefore even small changes in soil C stocks could lead to large changes in the atmospheric concentration of CO2. Since SOCCR-1, improvements have been made in quantifying stocks and uncertainties in stocks of soil C to a depth of 1 m across North America. Estimates for soil carbon stocks in the US (CONUS + Alaska) range from 151 - 162 Pg C, based on extensive sampling and analysis. Estimates for Canada average about 262 Pg C, but sampling is not as extensive. Soil C for Mexico is calculated as 18 Pg C, but there is a great deal of uncertainty surrounding this value. These soil carbon stocks are sensitive to agricultural management, land use and land cover change, and development and loss of C-rich soils such as wetlands. Climate change is a significant threat although may be partially mitigated by increased plant production. Carbon stored in permafrost zone circumpolar soils is equal to 1330-1580 Pg C, almost twice that contained in the atmosphere and about order of magnitude greater than carbon contained in plant biomass, woody debris, and litter in the boreal and tundra biomes combined. Surface air temperature change is amplified in high latitude regions such that Arctic temperature rise is about 2.5 times faster than for the globe as a whole, and thus 5 - 15% of this carbon is considered vulnerable to release to the atmosphere by the year 2100 following the current trajectory of global and Arctic warming. This amount is likely to be up to an order of magnitude larger loss than the increase in carbon stored in plant biomass under the same changing conditions. Models of soil organic matter dynamics have been greatly improved in the last decade by including greater process-level understanding of factors that affect soil C stabilization and destabilization, yet structural features of many models are still limited in representing Arctic and boreal

  16. A comprehensive monitoring program for North American shorebirds

    Science.gov (United States)

    Howe, Marshall; Bart, Jon; Brown, Stephen; Elphick, Chris; Gill, Robert E.; Harrington, Brian A.; Hickey, Catherine; Morrison, Guy; Skagen, Susan K.; Warnock, Nils

    2000-01-01

    Anthropogenic changes to the biosphere, including widespread degradation and losses of habitats and ecosystems, are causing rapid and profound changes to bird and other wildlife populations throughout the world. Such changes have led to increasing risks and rates of extinction. As a consequence, information on how bird populations are changing is becoming increasingly important to wildlife conservationists and managers. Early detection of population change is crucial for setting wildlife planning and management priorities. For example, information on population size, population vulnerability, and population change has been central to international conservation strategies such as the Ramsar Convention, the Western Hemisphere (Bonn) Convention, and the Western Hemisphere Shorebird Reserve Network. Measuring population size or change is also crucial for evaluating the effectiveness of population management programs implemented by wildlife agencies both locally and regionally.Although the concept of determining population size is simple, practical difficulties can be enormous and costly to overcome. In the United States, $4 billion will be spent in year 2000 to census the human population, possibly one of the most easily counted of all vertebrates. By contrast, the portion of the FY 2000 budget of the U.S. Department of the Interior allotted for tracking populations of all migratory birds (> 600 species) is less than $5 million (.0125% of the human census figure). This falls far short of the amount required to provide adequate, science-based information about bird populations and population change to wildlife managers.The gap between current ability and need is especially noteworthy for shorebirds. There are 72 species, subspecies, or distinct populations of shorebirds in North America. Even though most of these have received less conservation attention than such groups as waterfowl, colonial waterbirds, or songbirds, recent independent evaluation of data collected for

  17. Privacy, autonomy, and public policy: French and North American perspectives.

    Science.gov (United States)

    Merchant, Jennifer

    2016-12-01

    This article raises the question of whether in both the United States and in France, an individual's autonomy and private decision-making right(s) in matters of health care and access to reproductive technologies can be conciliated with the general interest, and more specifically, the role of the State. Can a full-fledged right to privacy, the ability to exercise one's autonomy, exist alongside the general interest, and depend neither on financial resources like in the United States nor on centralised government decisions or the medical hierarchy like in France? The contrast between these two modern democracies justify the importance of comparing them. I will demonstrate that overlaps do exist: the free exercise of religion and opinion, freedom of expression, the inherent value of each individual. What differs, however, are the institutions and how they provide, protect, promote, or frame access to and expressions of these democratic principles. The impact of the global economy, the exposure of people around the world to each other via the internet, and the mirror effects of social media, blogs, and other such forums, have created new perspectives that countries project onto one another. For example, does France now seem to tout 'autonomy' as a new and important value because it appears to be an 'American success story'? Does the United States now seem to value human rights and a social-democratic approach because of the 'French model'? There seems to be some truth behind these assertions, but as this article will demonstrate, the portrayals of what the 'right to privacy' is in the United States and what 'socialised medicine' is in France are not necessarily fully accurate.

  18. LIGHT TRANSMISSION and Other Data from CAPE HENLOPEN From North American Coastline-North from 19810416 to 19820312 (NODC Accession 8500080)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Light transmission and other data from Cape Henlopen from North American Coastline. Transmissometer data was collected by Lamont-Doherty Geological Observatory in...

  19. Visibility graph network analysis of natural gas price: The case of North American market

    Science.gov (United States)

    Sun, Mei; Wang, Yaqi; Gao, Cuixia

    2016-11-01

    Fluctuations in prices of natural gas significantly affect global economy. Therefore, the research on the characteristics of natural gas price fluctuations, turning points and its influencing cycle on the subsequent price series is of great significance. Global natural gas trade concentrates on three regional markets: the North American market, the European market and the Asia-Pacific market, with North America having the most developed natural gas financial market. In addition, perfect legal supervision and coordinated regulations make the North American market more open and more competitive. This paper focuses on the North American natural gas market specifically. The Henry Hub natural gas spot price time series is converted to a visibility graph network which provides a new direction for macro analysis of time series, and several indicators are investigated: degree and degree distribution, the average shortest path length and community structure. The internal mechanisms underlying price fluctuations are explored through the indicators. The results show that the natural gas prices visibility graph network (NGP-VGN) is of small-world and scale-free properties simultaneously. After random rearrangement of original price time series, the degree distribution of network becomes exponential distribution, different from the original ones. This means that, the original price time series is of long-range negative correlation fractal characteristic. In addition, nodes with large degree correspond to significant geopolitical or economic events. Communities correspond to time cycles in visibility graph network. The cycles of time series and the impact scope of hubs can be found by community structure partition.

  20. North american natural gas supply forecast: the Hubbert method including the effects of institutions

    International Nuclear Information System (INIS)

    Reynolds, D. B.; Kolodziej, M.

    2009-01-01

    In this article, the U.S. and southern Canadian natural gas supply market is considered. An important model for oil and natural gas supply is the Hubbert curve. Not all regions of the world are producing oil or natural gas following a Hubbert curve, even when price and market conditions are accounted for. One reason is that institutions are affecting supply. We investigate the possible effects of oil and gas market institutions in North America on natural gas supply. A multi-cycle Hubbert curve with inflection points similar to the Soviet Union's oil production multi-cycle Hubbert curve is used to determine North American natural gas discovery rates and to analyze how market specific institutions caused the inflection points. In addition, we analyze the latest shale natural gas projections critically. While currently, unconventional resources of natural gas suggest that North American natural gas production will increase without bound, the model here suggests a peak in North American natural gas supplies could happen in 2013. (author)

  1. Influenza a virus migration and persistence in North American wild birds.

    Directory of Open Access Journals (Sweden)

    Justin Bahl

    Full Text Available Wild birds have been implicated in the emergence of human and livestock influenza. The successful prediction of viral spread and disease emergence, as well as formulation of preparedness plans have been hampered by a critical lack of knowledge of viral movements between different host populations. The patterns of viral spread and subsequent risk posed by wild bird viruses therefore remain unpredictable. Here we analyze genomic data, including 287 newly sequenced avian influenza A virus (AIV samples isolated over a 34-year period of continuous systematic surveillance of North American migratory birds. We use a Bayesian statistical framework to test hypotheses of viral migration, population structure and patterns of genetic reassortment. Our results reveal that despite the high prevalence of Charadriiformes infected in Delaware Bay this host population does not appear to significantly contribute to the North American AIV diversity sampled in Anseriformes. In contrast, influenza viruses sampled from Anseriformes in Alberta are representative of the AIV diversity circulating in North American Anseriformes. While AIV may be restricted to specific migratory flyways over short time frames, our large-scale analysis showed that the long-term persistence of AIV was independent of bird flyways with migration between populations throughout North America. Analysis of long-term surveillance data provides vital insights to develop appropriately informed predictive models critical for pandemic preparedness and livestock protection.

  2. Brokers, consumers and the internet: how North American consumers navigate their infertility journeys.

    Science.gov (United States)

    Speier, Amy R

    2011-11-01

    North Americans who suffer infertility often reach an end to treatment options at home, whether it is due to a lack of egg donors in Canada or the high cost of treatment in the USA. Patients navigate their way onto the internet, seeking support and other options. As women and couples 'do the research' online, they conduct endless Google searches, come across IVF brokers, join support groups, read blogs and meet others on the road of infertility. This paper considers the journeys that North American patients make to clinics in Moravia, Czech Republic. Along these travels, patients engage with support groups, other patients, IVF brokers and clinic co-ordinators. Since the distance travelled between North America and Europe is extensive, reproductive travels may be arranged by clinical staff, travel brokers and patients. Acting as consumers, North Americans make different 'choices' along their journeys – the use of a broker, if and when they should join online communities, which clinic to visit and where to stay. This study focuses on the question of how patient choices often determine the success of brokers and clinics, thus influencing the structure of cross-border reproductive care in the Czech Republic. Copyright © 2011 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  3. Outlook and overview of the North American marketplace: 1997-2015

    International Nuclear Information System (INIS)

    Sitzer, S.

    1997-01-01

    A series of projections for natural gas prices and production patterns in North America to the year 2015 were presented, based on the 'Annual Energy Outlook 1997' (AEO97) and on the 'International Energy Outlook 1996' (IEO96), two publications of the US Energy Information Administration. AEO's primary focus is the U.S. domestic situation, whereas the IEO provides international forecasts and analysis. In general, it is expected that while the growth in U.S. demand will put severe strain on North American natural gas reserves, production and delivery systems, deregulation will provide the incentives to maintain the improvements in efficiency and deliverability that have characterized gas supply over the past 10 years. To buttress these predictions, a series of analysis on U.S. economic growth, energy demand, world oil prices, U.S. electricity generation and cogeneration by fuel type, U.S. natural gas supply and prices were modelled under different price scenarios. Estimates included Canadian and Mexican reserves, storage and productive capacities in the overall North American energy picture. It was concluded that because of the relatively abundant supply and low environmental emissions, natural gas will continue to play a key role in North American energy markets. 4 refs., 13 figs

  4. Anaerobic oral flora in the North American black bear (Ursus americanus) in eastern North Carolina.

    Science.gov (United States)

    Clarke, Elsburgh O; Stoskopf, Michael K; Minter, Larry J; Stringer, Elizabeth M

    2012-06-01

    Microbial flora can provide insight into the ecology and natural history of wildlife in addition to improving understanding of health risks. This study examines the anaerobic oral flora of hunter killed black bears (Ursus americanus) in eastern North Carolina. Oral swabs from the buccal and lingual supragingival tooth surfaces of the first and second mandibular and maxillary molars of 22 black bears were inoculated onto Brucella Blood Agar plates supplemented with hemin and vitamin K after transport from the field using reduced oxoid nutrient broth. Sixteen anaerobic bacterial species, representing nine genera were identified using the RapID ANA II Micromethod Kit system and a number of organisms grown that could not be identified with the system. The most frequently identified anaerobes were Peptostreptococcus prevotii, Streptococcus constellatus, and Porphyromonas gingivalis. The diversity in the anaerobic oral flora of black bear in eastern North Carolina suggests the importance of including these organisms in basic health risk assessment protocols and suggests a potential tool for assessment of bear/habitat interactions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Opportunities for Canadian stakeholders in the North American large wind turbine supply chain

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    Wind energy is the fastest growing source of electricity in terms of annual installed capacity. This report presented a study of the North American large wind turbine generator supply chain and technological innovation challenges, and identified opportunities for Canadian industrial and research stakeholders to increase their participation in the wind industry. The study was conducted in three phases. The report described each of these phases, which included identification of the North American turbine supply chain needs and opportunities and its technological innovation challenges; identification of Canadian industrial and research stakeholders, either currently involved in the wind sector or external to it, which had strong transferable skills or capabilities to respond to the specific opportunities; and an assessment of the overall likelihood of Canadian stakeholders being able to respond to specific opportunities within the large wind turbine manufacturing segment of the supply chain. The report provided a market overview of the global, American and Canadian markets and discussed the key North American market drivers and potential economic benefits of wind power. The report also presented an overview of drivers for success in major markets jurisdictions and discussed the large wind turbine supply chain. Several strategic recommendations were offered, such as establishing and maintaining an open line of communication with key contacts within prime contractor and component manufacturer organizations; and maintaining and strengthening wind market policies and creating long-term market signals. refs., tabs., figs.

  6. How neuroscience is taught to North American dental students: results of the Basic Science Survey Series.

    Science.gov (United States)

    Gould, Douglas J; Clarkson, Mackenzie J; Hutchins, Bob; Lambert, H Wayne

    2014-03-01

    The purpose of this study was to determine how North American dental students are taught neuroscience during their preclinical dental education. This survey represents one part of a larger research project, the Basic Science Survey Series for Dentistry, which covers all of the biomedical science coursework required of preclinical students in North American dental schools. Members of the Section on Anatomical Sciences of the American Dental Education Association assembled, distributed, and analyzed the neuroscience survey, which had a 98.5 percent response from course directors of the sixty-seven North American dental schools. The eighteen-item instrument collected demographic data on the course directors, information on the content in each course, and information on how neuroscience content is presented. Findings indicate that 1) most neuroscience instruction is conducted by non-dental school faculty members; 2) large content variability exists between programs; and 3) an increase in didactic instruction, integrated curricula, and use of computer-aided instruction is occurring. It is anticipated that the information derived from the survey will help guide neuroscience curricula in dental schools and aid in identifying appropriate content.

  7. Business Guests Satisfaction in the Hotel Industry: A Case Study of North American Hotel Chains

    Directory of Open Access Journals (Sweden)

    Milan Bradić

    2013-04-01

    Full Text Available This paper considers the problem of satisfaction of business guests with hotel brands in North America. In analysis we used the guests responses (scores given for 12 different elements of hotel product. In order to arrive at more accurate results, monitored hotel chains are grouped into price tiers. The aim of this paper is to indicate what facilities and services the North American business guests appreciate most. Industry trends and results may be beneficial to all hoteliers, especially in business tourism segment.

  8. Close relationship of Plasmodium sequences detected from South American pampas deer (Ozotoceros bezoarticus to Plasmodium spp. in North American white-tailed deer

    Directory of Open Access Journals (Sweden)

    Masahito Asada

    2018-04-01

    Full Text Available We report, for the first time, the presence of ungulate malaria parasites in South America. We conducted PCR-based surveys of blood samples of multiple deer species and water buffalo from Brazil and detected Plasmodium sequences from pampas deer (Ozotoceros bezoarticus samples. Phylogenic analysis revealed that the obtained sequences are closely related to the Plasmodium odocoilei clade 2 sequence from North American white-tailed deer (Odocoileus virginianus. Nucleotide differences suggest that malaria parasites in South American pampas deer and North American P. odocoilei clade 2 branched more recently than the Great American Interchange. Keywords: Malaria, Pampas deer, South America, Plasmodium odocoilei, Brazil

  9. The impact of West Nile virus on the abundance of selected North American birds

    Directory of Open Access Journals (Sweden)

    Beard Raphaelle H

    2011-08-01

    Full Text Available Abstract Background The emergence of West Nile virus (WNV in North America has been associated with high mortality in the native avifauna and has raised concerns about the long-term impact of WNV on bird populations. Here, we present results from a longitudinal analysis of annual counts of six bird species, using North American Breeding Bird Survey data from ten states (1994 to 2010. We fit overdispersed Poisson models to annual counts. Counts from successive years were linked by an autoregressive process that depended on WNV transmission intensity (annual West Nile neuroinvasive disease reports and was adjusted by El Niño Southern Oscillation events. These models were fit using a Markov chain Monte Carlo algorithm. Results Model fit was mostly excellent, especially for American Crows, for which our models explained between 26% and 81% of the observed variance. The impact of WNV on bird populations was quantitatively evaluated by contrasting hypothetical count trajectories (omission of WNV with observed counts. Populations of American crows were most consistently affected with a substantial cumulative impact in six of ten states. The largest negative impact, almost 60%, was found in Illinois. A regionally substantial decline was also seen for American Robins and House Sparrows, while the other species appeared unaffected. Conclusions Our results confirm findings from previous studies that single out American Crows as the species most vulnerable to WNV infection. We discuss strengths and limitations of this and other methods for quantifying the impact of WNV on bird populations.

  10. Identification of exotic North American crayfish in Europe by DNA barcoding

    Directory of Open Access Journals (Sweden)

    Filipová L.

    2011-05-01

    Full Text Available Several alien crayfish of North American origin have become established in Europe in recent decades, but their identification is often confusing. Our aim was to verify the taxonomic status of their European populations by DNA barcoding. We sequenced the cytochrome c oxidase subunit I (COI gene fragment of individuals representing all American crayfish known from European waters, and compared the results with reference sequences from North America. Our results confirm the morphological identification of Orconectes juvenilis from a population in eastern France, and of the marbled crayfish (Marmorkrebs, i.e., a parthenogenetic form of Procambarus fallax, from south-western Germany. Sequences of most individuals of presumed Procambarus acutus from the Netherlands were similar to American P. cf. acutus, but one was divergent, closer to a sequence of a reference individual of P. cf. zonangulus. However, divergences among three American P. cf. zonangulus samples were also high, comparable to interspecific variation within cambarid species complexes. The divergence between O. immunis from Europe and America also reached values corresponding to those observed among distinct Orconectes species. Genetic variation in the American range of these crayfish should therefore be further studied. Our study shows that DNA barcoding is useful for the rapid and accurate identification of exotic crayfish in Europe, and also provides insights into overall variation within these taxa.

  11. DEPRESSION AND GUILT IN INDIAN AND NORTH AMERICAN PATIENTS: A COMPARATIVE STUDY

    Science.gov (United States)

    Ananth, Jambur; Engelsman, Frank; Ghadirian, A.M.; Wohl, Marcy; Shamasundara, Padmini; Narayanan, H.S.

    1993-01-01

    SUMMARY One hundred and nineteen Indian and one hundred and fourteen North American depressed patients were compared to assess the differences in psychopathology. The study revealed two important findings: 1) Indian patients scored significantly higher than American patients on the HAMD items of poor appetite, hypochondriasis, diurnal variation, and psychomotor retardation; and lower on the items of anxiety and middle insomnia. 2) Guilt was expressed less often by Indian patients. Guilt was more common among those who felt that God was responsible for their depression and in those who believed in reincarnation. These differences may be related to cultural factors and not to religious beliefs. PMID:21776166

  12. Carbon sequestration potential of second-growth forest regeneration in the Latin American tropics

    NARCIS (Netherlands)

    Chazdon, R.L.; Broadbent, E.N.; Rozendaal, Danae; Bongers, F.; Jakovac, A.C.; Braga Junqueira, A.; Lohbeck, M.W.M.; Pena Claros, M.; Poorter, L.

    2016-01-01

    Regrowth of tropical secondary forests following complete or nearly complete removal of forest vegetation actively stores carbon in aboveground biomass, partially counterbalancing carbon emissions from deforestation, forest degradation, burning of fossil fuels, and other anthropogenic sources. We

  13. Teaching methods and surgical training in North American graduate periodontics programs: exploring the landscape.

    Science.gov (United States)

    Ghiabi, Edmond; Taylor, K Lynn

    2010-06-01

    This project aimed at documenting the surgical training curricula offered by North American graduate periodontics programs. A survey consisting of questions on teaching methods employed and the content of the surgical training program was mailed to directors of all fifty-eight graduate periodontics programs in Canada and the United States. The chi-square test was used to assess whether the residents' clinical experience was significantly (Pperiodontal plastic procedures, hard tissue grafts, and implants. Furthermore, residents in programs offering a structured preclinical component performed significantly more procedures (P=0.012) using lasers than those in programs not offering a structured preclinical program. Devising new and innovative teaching methods is a clear avenue for future development in North American graduate periodontics programs.

  14. Quest for professionalism: a biography of the North American Medical and Surgical Journal (1826-31).

    Science.gov (United States)

    Shultz, S M

    2011-08-01

    This is the biography of a deceased medical journal, the North American Medical and Surgical Journal, born in 1826 in Philadelphia. It was a publication of the Philadelphia Chapter of the Kappa Lambda Society. In the prospectus of the North American Medical and Surgical Journal the promoters observed that a well-conducted journal would achieve the object of elevating the medical profession to its legitimate rank which up to that time had been the recipient of low public opinion. The Journal hoped to inculcate 'a higher standard of excellence not merely in the professional or ministrative but also in the ethical relations and duties of physicians'. After several successful and productive years it passed into history in October 1831, the victim of financial difficulty.

  15. Thomas George Lee - Implantation and early development of North American rodents

    DEFF Research Database (Denmark)

    Carter, Anthony Michael

    2011-01-01

    A century ago Thomas G. Lee amassed an unparalleled collection of developmental series of North American rodents such as the thirteen-lined ground squirrel, the Plains pocket gopher and Merriam's kangaroo rat. He was the first to describe the initial attachment of the squirrel blastocyst to the a......A century ago Thomas G. Lee amassed an unparalleled collection of developmental series of North American rodents such as the thirteen-lined ground squirrel, the Plains pocket gopher and Merriam's kangaroo rat. He was the first to describe the initial attachment of the squirrel blastocyst...... to the antimesometrial side of the uterus. The full potential of Lee's material was not realized until after his death, when it came into the possession of Mossman. The latter relied heavily on Lee's collection when writing his seminal monograph on the comparative morphogenesis of fetal membranes and much of Lee...

  16. Proceedings of the CERI 2006 petrochemical conference : thinking outside the box : preparing tomorrow's North American industry

    International Nuclear Information System (INIS)

    2006-01-01

    This conference addressed the global competitiveness of the Canadian petrochemical industry and its potential markets. Recent advances in technology were highlighted along with issues concerning transportation and infrastructure. In addition to addressing capital cost requirements and feedstock availability, the presentations addressed opportunities for growth and product diversification. Alberta's role in the North American energy markets was also discussed, along with issues concerning feedstock from Canadian oil sands. It was noted that the survival of the North American petrochemical industry depends on the price of natural gas liquids. With feedstock at two to three times the price in the Middle East, petrochemical producers, governments, and suppliers need to adopt aggressive strategies to maintain a competitive position and profitability. The sessions of the conference addressed global competitive issues; integration and mastering competitiveness; the Alberta advantage; feedstock and technologies; and, reaching international markets. The conference featured 18 presentations, of which 7 have been catalogued separately for inclusion in this database. refs., tabs., figs

  17. Crowdsourcing methodology: establishing the Cervid Disease Network and the North American Mosquito Project.

    Science.gov (United States)

    Cohnstaedt, Lee W; Snyder, Darren; Maki, Elin; Schafer, Shawn

    2016-06-30

    Crowdsourcing is obtaining needed services, ideas, or content by soliciting contributions from a large group of people. This new method of acquiring data works well for single reports, but fails when long-term data collection is needed, mainly due to reporting fatigue or failure of repeated sampling by individuals. To establish a crowdsourced collections network researchers must recruit, reward, and retain contributors to the project. These 3 components of crowdsourcing are discussed using the United States Department of Agriculture social networks, the Cervid Disease Network, and the North American Mosquito Project. The North American Mosquito Project is a large network of professional mosquito control districts and public health agencies, which collects mosquito specimens for genetic studies. The Cervid Disease Network is a crowd-sourced disease monitoring system, which uses voluntary sentinel farms or wildlife programs throughout the United States of America to report the onset and severity of diseases in local areas for pathogen surveillance studies.

  18. Latitudinal Change of Tropical Cyclone Maximum Intensity in the Western North Pacific

    OpenAIRE

    Choi, Jae-Won; Cha, Yumi; Kim, Hae-Dong; Kang, Sung-Dae

    2016-01-01

    This study obtained the latitude where tropical cyclones (TCs) show maximum intensity and applied statistical change-point analysis on the time series data of the average annual values. The analysis results found that the latitude of the TC maximum intensity increased from 1999. To investigate the reason behind this phenomenon, the difference of the average latitude between 1999 and 2013 and the average between 1977 and 1998 was analyzed. In a difference of 500 hPa streamline between the two ...

  19. Long term changes in flooding and heavy rainfall associated with North Atlantic tropical cyclones: Roles of the North Atlantic Oscillation and El Niño-Southern Oscillation

    Science.gov (United States)

    Aryal, Yog N.; Villarini, Gabriele; Zhang, Wei; Vecchi, Gabriel A.

    2018-04-01

    The aim of this study is to examine the contribution of North Atlantic tropical cyclones (TCs) to flooding and heavy rainfall across the continental United States. Analyses highlight the spatial variability in these hazards, their temporal changes in terms of frequency and magnitude, and their connection to large-scale climate, in particular to the North Atlantic Oscillation (NAO) and El Niño-Southern Oscillation (ENSO). We use long-term stream and rain gage measurements, and our analyses are based on annual maxima (AMs) and peaks-over-threshold (POTs). TCs contribute to ∼20-30% of AMs and POTs over Florida and coastal areas of the eastern United States, and the contribution decreases as we move inland. We do not detect statistically significant trends in the magnitude or frequency of TC floods. Regarding the role of climate, NAO and ENSO do not play a large role in controlling the frequency and magnitude of TC flooding. The connection between heavy rainfall and TCs is comparable to what observed in terms of flooding. Unlike flooding, NAO plays a significant role in TC-related extreme rainfall along the U.S. East Coast, while ENSO is most strongly linked to the TC precipitation in Texas.

  20. Microstructured barbs on the North American porcupine quill enable easy tissue penetration and difficult removal

    OpenAIRE

    Cho, Woo Kyung; Ankrum, James A.; Guo, Dagang; Chester, Shawn A.; Yang, Seung Yun; Kashyap, Anurag; Campbell, Georgina A.; Wood, Robert J.; Rijal, Ram K.; Karnik, Rohit; Langer, Robert; Karp, Jeffrey M.

    2012-01-01

    North American porcupines are well known for their specialized hairs, or quills that feature microscopic backward-facing deployable barbs that are used in self-defense. Herein we show that the natural quill’s geometry enables easy penetration and high tissue adhesion where the barbs specifically contribute to adhesion and unexpectedly, dramatically reduce the force required to penetrate tissue. Reduced penetration force is achieved by topography that appears to create stress concentrations al...

  1. Evaluating North American Electric Grid Reliability Using the Barabasi-Albert Network Model

    OpenAIRE

    Chassin, David P.; Posse, Christian

    2004-01-01

    The reliability of electric transmission systems is examined using a scale-free model of network structure and failure propagation. The topologies of the North American eastern and western electric networks are analyzed to estimate their reliability based on the Barabasi-Albert network model. A commonly used power system reliability index is computed using a simple failure propagation model. The results are compared to the values of power system reliability indices previously obtained using s...

  2. Coastal Contacts’ Business Development in the North American Online Retail Eyeglass Market

    OpenAIRE

    Petersen, Curtis

    2011-01-01

    The following paper is an analysis of Coastal Contacts Inc. and the North American retail eyeglass industry. Coastal Contacts is an online retailer of contact lenses and prescription eyeglasses. At the time of writing the company has recently entered the eyeglasses market. This industry has an underdeveloped online retail channel. The reason the channel has not developed as quickly as other products such as contact lenses is because eyeglasses are a more complicated purchase. As more purchase...

  3. Is there an East-West split in North-American natural gas markets?

    OpenAIRE

    Serletis, Apostolos

    1997-01-01

    This paper presents evidence concerning shared stochastic trends in North American natural gas (spot) markets, using monthly data for the period that natural gas has been traded on organized exchanges (from June, 1990 to January, 1996). In doing so, it uses the Engle and Granger (1987) approach for estimating bivariate cointegrating relationships as well as Johansen's (1988) maximum likelihood approach for estimating cointegrating relationships in multivariate vector autoregressive models. Th...

  4. North American Oriented Strand Board Markets, Arbitrage Activity, and Market Price Dynamics: A Smooth Transition Approach

    OpenAIRE

    Goodwin, Barry K.; Holt, Matthew T.; Prestemon, Jeffery P.

    2008-01-01

    Price dynamics for North American oriented strand board (OSB) markets are examined. The role of transactions costs are explored vis-a-vis the law of one price. Weekly data, February 3rd, 1995 through October 9th, 2009, are used in the analysis. Nonlinearities induced by unobservable transactions costs are modeled by estimating Time-Varying Smooth Transition Autoregressions (TV-STARs). Results indicate that nonlinearity and structural change are important features of these markets; price...

  5. On the dynamic of franchise (re)location in the North-American sport leagues

    OpenAIRE

    Narme, Thibaut

    2013-01-01

    As the cost of tax-dollar paid stadia rises and the talks of relocations in the main North-American pro leagues increase, a multi-field analysis on the different mechanisms that decides team relocation seems necessary. This paper reviews the different mechanisms participating team location and finally offer a new angle of analysis on the actual equilibrium and demonstrates its dynamic nature.

  6. The Outlier Sectors: Areas of Non-Free Trade in the North American Free Trade Agreement

    OpenAIRE

    Eric T. Miller

    2002-01-01

    Since its entry into force, the North American Free Trade Agreement (NAFTA) has been enormously influential as a model for trade liberalization. While trade in goods among Canada, the United States and Mexico has been liberalized to a significant degree, this most famous of agreements nonetheless contains areas of recalcitrant protectionism. The first part of this paper identifies these "outlier sectors" and classifies them by primary source advocating protectionism, i.e., producer interests ...

  7. Serological Evidence of Hepatitis E Virus Infection in an Indigenous North American Population

    Directory of Open Access Journals (Sweden)

    GY Minuk

    2007-01-01

    Full Text Available BACKGROUND: Hepatitis E virus (HEV infections are thought to be uncommon in North America. Recently, HEV transmission has been reported following the consumption of deer meat. Because deer are closely related to caribou and caribou meat is a staple of the Canadian Inuit and the American Eskimo diet, the present study explored the seroprevalence of HEV infection in an isolated Canadian Inuit community.

  8. Malaria incidence and prevention among European and North American travellers to Kenya.

    OpenAIRE

    Lobel, H. O.; Phillips-Howard, P. A.; Brandling-Bennett, A. D.; Steffen, R.; Campbell, C. C.; Huong, A. Y.; Were, J. B.; Moser, R.

    1990-01-01

    A longitudinal survey was conducted among travellers departing from Nairobi airport to determine the use of malaria prevention measures and assess the risk for malaria while travelling in Kenya. Among 5489 European and North American travellers, 68 different drug regimens were used for prophylaxis, and 48% of travellers used both regular chemoprophylaxis and more than 1 antimosquito measure during travel; 52% of 3469 travellers who used chemoprophylaxis did so without interruption during thei...

  9. 13th North American Caribou Workshop, 25-28 October 2010, Winnipeg, Manitoba, Canada.

    Directory of Open Access Journals (Sweden)

    Rolf Egil Haugerud (editor in chief

    2012-03-01

    Full Text Available The 13th North American Caribou Workshop which was held in Winnipeg, Manitoba, was a great success with more than 400 participants: people from Canada, the United States, Norway and Greenland, representatives from co-management and resource management boards across North America, First Nations, Inuit and Inuvialuit, governmental and non-governmental organisations, private companies, researchers, students and youth. The theme of the Workshop was Sustaining Caribou and their Landscapes – Knowledge to Action and the intent of the organizers was twofold: first, to provide participants with the opportunity to share scientific and traditional knowledge on different subspecies and ecotypes of Rangifer across the circumpolar North, the particularities of the different landscapes and land use management issues; second, to explore innovative ways to transfer knowledge to action, ensuring the long-term persistence of Rangifer throughout its range through the development of better governance structures, sound policies and effective communication.

  10. Extended-range forecast for the temporal distribution of clustering tropical cyclogenesis over the western North Pacific

    Science.gov (United States)

    Zhu, Zhiwei; Li, Tim; Bai, Long; Gao, Jianyun

    2017-11-01

    Based on outgoing longwave radiation (OLR), an index for clustering tropical cyclogenesis (CTC) over the western North Pacific (WNP) was defined. Around 76 % of total CTC events were generated during the active phase of the CTC index, and 38 % of the total active phase was concurrent with CTC events. For its continuous property, the CTC index was used as the representative predictand for extended-range forecasting the temporal distribution of CTC events. The predictability sources for CTC events were detected via correlation analyses of the previous 35-5-day lead atmospheric fields against the CTC index. The results showed that the geopotential height at different levels and the 200 hPa zonal wind over the global tropics possessed large predictability sources, whereas the predictability sources of other variables, e.g., OLR, zonal wind, and relatively vorticity at 850 hPa and relatively humility at 700 hPa, were mainly confined to the tropical Indian Ocean and western Pacific Ocean. Several spatial-temporal projection model (STPM) sets were constructed to carry out the extended-range forecast for the CTC index. By combining the output of STPMs separately conducted for the two dominant modes of intraseasonal variability, e.g., the 10-30 and the 30-80 day mode, useful forecast skill could be achieved for a 30-day lead time. The combined output successfully captured both the 10-30 and 30-80 day mode at least 10 days in advance. With a relatively low rate of false alarm, the STPM achieved hits for 80 % (69 %) of 54 CTC events during 2003-2014 at the 10-day (20-day) lead time, suggesting a practical value of the STPM for real-time forecasting WNP CTC events at an extended range.

  11. Potential use of a regional climate model in seasonal tropical cyclone activity predictions in the western North Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Au-Yeung, Andie Y.M.; Chan, Johnny C.L. [City University of Hong Kong, Guy Carpenter Asia-Pacific Climate Impact Centre, School of Energy and Environment, Kowloon, Hong Kong (China)

    2012-08-15

    This study investigates the potential use of a regional climate model in forecasting seasonal tropical cyclone (TC) activity. A modified version of Regional Climate Model Version 3 (RegCM3) is used to examine the ability of the model to simulate TC genesis and landfalling TC tracks for the active TC season in the western North Pacific. In the model, a TC is identified as a vortex satisfying several conditions, including local maximum relative vorticity at 850 hPa with a value {>=}450 x 10{sup -6} s{sup -1}, and the temperature at 300 hPa being 1 C higher than the average temperature within 15 latitude radius from the TC center. Tracks are traced by following these found vortices. Six-month ensemble (8 members each) simulations are performed for each year from 1982 to 2001 so that the climatology of the model can be compared to the Joint Typhoon Warning Center (JTWC) observed best-track dataset. The 20-year ensemble experiments show that the RegCM3 can be used to simulate vortices with a wind structure and temperature profile similar to those of real TCs. The model also reproduces tracks very similar to those observed with features like genesis in the tropics, recurvature at higher latitudes and landfall/decay. The similarity of the 500-hPa geopotential height patterns between RegCM3 and the European Centre for Medium-Range Weather Forecasts 40 Year Re-analysis (ERA-40) shows that the model can simulate the subtropical high to a large extent. The simulated climatological monthly spatial distributions as well as the interannual variability of TC occurrence are also similar to the JTWC data. These results imply the possibility of producing seasonal forecasts of tropical cyclones using real-time global climate model predictions as boundary conditions for the RegCM3. (orig.)

  12. Coccolithophore fluxes in the open tropical North Atlantic: influence of thermocline depth, Amazon water, and Saharan dust

    Directory of Open Access Journals (Sweden)

    C. V. Guerreiro

    2017-10-01

    Full Text Available Coccolithophores are calcifying phytoplankton and major contributors to both the organic and inorganic oceanic carbon pumps. Their export fluxes, species composition, and seasonal patterns were determined in two sediment trap moorings (M4 at 12° N, 49° W and M2 at 14° N, 37° W collecting settling particles synchronously from October 2012 to November 2013 at 1200 m of water depth in the open equatorial North Atlantic. The two trap locations showed a similar seasonal pattern in total coccolith export fluxes and a predominantly tropical coccolithophore settling assemblage. Species fluxes were dominated throughout the year by lower photic zone (LPZ taxa (Florisphaera profunda, Gladiolithus flabellatus but also included upper photic zone (UPZ taxa (Umbellosphaera spp., Rhabdosphaera spp., Umbilicosphaera spp., Helicosphaera spp.. The LPZ flora was most abundant during fall 2012, whereas the UPZ flora was more important during summer. In spite of these similarities, the western part of the study area produced persistently higher fluxes, averaging 241×107 ± 76×107 coccoliths m−2 d−1 at station M4 compared to only 66×107 ± 31×107 coccoliths m−2 d−1 at station M2. Higher fluxes at M4 were mainly produced by the LPZ species, favoured by the westward deepening of the thermocline and nutricline. Still, most UPZ species also contributed to higher fluxes, reflecting enhanced productivity in the western equatorial North Atlantic. Such was the case of two marked flux peaks of the more opportunistic species Gephyrocapsa muellerae and Emiliania huxleyi in January and April 2013 at M4, indicating a fast response to the nutrient enrichment of the UPZ, probably by wind-forced mixing. Later, increased fluxes of G. oceanica and E. huxleyi in October–November 2013 coincided with the occurrence of Amazon-River-affected surface waters. Since the spring and fall events of 2013 were also accompanied by two dust

  13. Influences of introduced plague on North American mammals: Implications from ecology of plague in Asia

    Science.gov (United States)

    Biggins, D.E.; Kosoy, M.Y.

    2001-01-01

    Intercontinental movements of invasive species continue to modify the world's ecosystems. The plague bacterium (Yersinia pestis) has colonized and altered animal communities worldwide but has received much more attention as a human pathogen. We reviewed studies on the ecology of Y. pestis in ancient foci of central Asia and in western North America, where the bacterium apparently has become established much more recently. Although rodent populations on both continents are affected dramatically by epizootics of plague, the epidemiologically important species of Asia demonstrate resistance in portions of their populations, whereas those of North America are highly susceptible. Individual variation in resistance, which is widespread in Asian rodents and allows a microevolutionary response, has been documented in few North American species of rodents. Plague increases costs of sociality and coloniality in susceptible hosts, increases benefits of disease resistance in general, and increases benefits of adaptability to variable environments for species at higher trophic levels. Prairie dogs (Cynomys) epitomize taxa with high risk to plague because prairie dogs have uniformly low resistance to plague and are highly social. Relationships to plague are poorly understood for many North American rodents, but more than one-half of the species of conservation concern occur within the geographic range of plague.

  14. Biogeography of Coptis Salisb. (Ranunculales, Ranunculaceae, Coptidoideae), an Eastern Asian and North American genus.

    Science.gov (United States)

    Xiang, Kun-Li; Erst, Andrey S; Xiang, Xiao-Guo; Jabbour, Florian; Wang, Wei

    2018-05-24

    Numerous studies have favored dispersal (colonization) over vicariance (past fragmentation) events to explain eastern Asian-North American distribution patterns. In plants, however the disjunction between eastern Asia and western North America has been rarely examined using the integration of phylogenetic, molecular dating, and biogeographical methods. Meanwhile, the biogeographic patterns within eastern Asia remain poorly understood. The goldthread genus Coptis Salisb. includes 15 species disjunctly distributed in North America, Japan, mainland China, and Taiwan. We present a dated phylogeny for Coptis under the optimal clock model and infer its historical biogeography by comparing different biogeographic models. The split of Coptis and Xanthorhiza Marshall occurred in the middle Miocene (ca. 15.47 Ma). Coptis started their diversification in the early late Miocene (ca. 9.55 Ma). A late Miocene vicariance event resulted in the eastern Asian and western North American disjunction in the genus. Within eastern Asia, dispersals from mainland Asia to Japan and from Japan to Taiwan occurred at ca. 4.85 Ma and at ca. 1.34 Ma, respectively. Our analyses provide evidence that both vicariance and dispersal events have played important roles in shaping the current distribution and endemism of Coptis, likely resulting from eustatic sea-level changes, mountain formation processes and an increasing drier and cooler climate from the middle Miocene onwards.

  15. Comparing Terrestrial Organic Carbon Cycle Dynamics in Interglacial and Glacial Climates in the South American Tropics

    Science.gov (United States)

    Fornace, K. L.; Galy, V.; Hughen, K. A.

    2014-12-01

    The application of compound-specific radiocarbon dating to molecular biomarkers has allowed for tracking of specific organic carbon pools as they move through the environment, providing insight into complex processes within the global carbon cycle. Here we use this technique to investigate links between glacial-interglacial climate change and terrestrial organic carbon cycling in the catchments of Cariaco Basin and Lake Titicaca, two tropical South American sites with well-characterized climate histories since the last glacial period. By comparing radiocarbon ages of terrestrial biomarkers (leaf wax compounds) with deposition ages in late glacial and Holocene sediments, we are able to gauge the storage time of these compounds in the catchments in soils, floodplains, etc. before transport to marine or lacustrine sediments. We are also able to probe the effects of temperature and hydrologic change individually by taking advantage of opposite hydrologic trends at the two sites: while both were colder during the last glacial period, precipitation at Titicaca decreased from the last glacial period to the Holocene, but the late glacial was marked by drier conditions at Cariaco. Preliminary data from both sites show a wide range of apparent ages of long-chain n-fatty acids (within error of 0 to >10,000 years older than sediment), with the majority showing ages on the order of several millennia at time of deposition and age generally increasing with chain length. While late glacial leaf waxes appear to be older relative to sediment than those deposited in the Holocene at both sites, at Cariaco we find a ~2-3 times larger glacial-interglacial age difference than at Titicaca. We hypothesize that at Titicaca the competing influences of wetter and colder conditions during the last glacial period, which respectively tend to increase and decrease the rate of organic carbon turnover on land, served to minimize the contrast between glacial and interglacial leaf wax storage time

  16. Prediction of tropical cyclone over North Indian Ocean using WRF model: sensitivity to scatterometer winds, ATOVS and ATMS radiances

    KAUST Repository

    Dodla, Venkata B.

    2016-05-03

    Tropical cyclone prediction, in terms of intensification and movement, is important for disaster management and mitigation. Hitherto, research studies were focused on this issue that lead to improvement in numerical models, initial data with data assimilation, physical parameterizations and application of ensemble prediction. Weather Research and Forecasting (WRF) model is the state-of-art model for cyclone prediction. In the present study, prediction of tropical cyclone (Phailin, 2013) that formed in the North Indian Ocean (NIO) with and without data assimilation using WRF model has been made to assess impacts of data assimilation. WRF model was designed to have nested two domains of 15 and 5 km resolutions. In the present study, numerical experiments are made without and with the assimilation of scatterometer winds, and radiances from ATOVS and ATMS. The model performance was assessed in respect to the movement and intensification of cyclone. ATOVS data assimilation experiment had produced the best prediction with least errors less than 100 km up to 60 hours and producing pre-deepening and deepening periods accurately. The Control and SCAT wind assimilation experiments have shown good track but the errors were 150-200 km and gradual deepening from the beginning itself instead of sudden deepening.

  17. Perspective on the northwestward shift of autumn tropical cyclogenesis locations over the western North Pacific from shifting ENSO

    Science.gov (United States)

    Hu, Chundi; Zhang, Chengyang; Yang, Song; Chen, Dake; He, Shengping

    2017-11-01

    During the recent decades of satellite era, more tropical cyclogenesis locations (TCLs) were observed over the northwestern part of the western North Pacific (WNP), relative to the southeastern part, during the boreal autumn. This increase in TCLs over the northwestern WNP is largely attributed to the synergy of shifting El Niño-Southern Oscillation (ENSO) and the 1998 Pacific climate regime shift. Both central Pacific (CP) La Niña and CP El Niño have occurred more frequently since 1998, with only one eastern Pacific El Niño observed in autumn 2015. The change in the mean longitude of TCLs is closely linked to the ENSO diversity, whereas the change in the mean latitude is dominated by the warming of the WNP induced by an interdecadal tendency of CP La Niña-like events. The physical mechanisms responsible for this shifting ENSO-TCL linkage can be potentially explained by the tacit-and-mutual configurations between tropical upper-tropospheric trough and monsoon trough, on both interannual and interdecadal timescales, which is mainly due to the ENSO-related large-scale environment changes in ocean and atmosphere that modulate the WNP TCL.

  18. Providing reliable energy in a time of constraints : a North American concern

    International Nuclear Information System (INIS)

    Egan, T.; Turk, E.

    2008-04-01

    The reliability of the North American electricity grid was discussed. Government initiatives designed to control carbon dioxide (CO 2 ) and other emissions in some regions of Canada may lead to electricity supply constraints in other regions. A lack of investment in transmission infrastructure has resulted in constraints within the North American transmission grid, and the growth of smaller projects is now raising concerns about transmission capacity. Labour supply shortages in the electricity industry are also creating concerns about the long-term security of the electricity market. Measures to address constraints must be considered in the current context of the North American electricity system. The extensive transmission interconnects and integration between the United States and Canada will provide a framework for greater trade and market opportunities between the 2 countries. Coordinated actions and increased integration will enable Canada and the United States to increase the reliability of electricity supply. However, both countries must work cooperatively to increase generation supply using both mature and emerging technologies. The cross-border transmission grid must be enhanced by increasing transmission capacity as well as by implementing new reliability rules, building new infrastructure, and ensuring infrastructure protection. Barriers to cross-border electricity trade must be identified and avoided. Demand-side and energy efficiency measures must also be implemented. It was concluded that both countries must focus on developing strategies for addressing the environmental concerns related to electricity production. 6 figs

  19. Are pharmacological interventions between conception and birth effective in improving reproductive outcomes in North American swine?

    Science.gov (United States)

    Wessels, J M; Khalaj, K; Kridli, R T; Edwards, A K; Bidarimath, M; Tayade, C

    2014-08-01

    The objective of this review is to evaluate the effectiveness of using pharmacological compounds on reproductive outcomes, particularly litter size, in North American swine. While the opportunity to improve reproduction in North American pigs exists, numerous hurdles need to be overcome in order to achieve measureable results. In the swine industry, the majority of piglet losses are incurred during pregnancy and around farrowing. Over the last 20 years, a reduction in losses has been achieved through genetic selection and nutritional management; however, these topics are the focus of other reviews. This review will evaluate attempts to improve litter size by reducing losses at various stages of the reproductive process, from the time of conception to the time of farrowing, using pharmacological compounds. Generally, these compounds are used to either alter physiological processes related to fertilization, embryonic attachment or uterine capacity, etc., or to facilitate management aspects of the breeding females such as inducing parturition. Although some of the pharmacological agents reviewed here show some positive effects on improving reproductive parameters, the inconsistent results and associated risks usually outweigh the benefits gained. Thus, at the present time, the use of pharmacological agents to enhance reproduction in North American swine may only be recommended for herds with low fertility and presents an avenue of research that could be further explored. © 2014 Blackwell Verlag GmbH.

  20. Social Determinants of Traumatic Brain Injury in the North American Indigenous Population: A Review.

    Science.gov (United States)

    Zeiler, Kaitlin J; Zeiler, Frederick A

    2017-09-01

    Given the difficult to navigate literature on social determinants in Indigenous traumatic brain injury (TBI) we wished to identify all available literature on the social determinants of health linked to TBI in the North American Indigenous populations. We performed a systematically conducted review. We searched MEDLINE, BIOSIS, EMBASE, Global Health, SCOPUS, and Cochrane Library from inception to January 2016. A two-step review process of the search results was performed, applying defined inclusion/exclusion criteria. The final group of articles had the data extracted and summarized. Ten manuscripts were identified to discuss some social determinant linked to TBI in the North American Indigenous populations. Two studies were focused on Canadian populations, with the remaining 8 studies focused on populations within the United States. Six social health determinants were identified within the studies, including: Rural location (Physical Environment) in seven studies, Male gender in five studies and Female gender in one study (in the setting of interpersonal violence) (Gender), Substance use in four studies and failure to utilize personal protective equipment in one study (Personal Health Practices and Coping Skills), Interpersonal Violence in one study (Social Environment), availability of rehabilitation services in one study (Health Services), and lack of family and friend presence during meetings with healthcare professionals in one study (Social Support Network). To date, little literature is available on the social determinants that impact TBI in the North American Indigenous population. Further research is warranted to better determine the incidence and social determinants associated.

  1. Wet Wipe Allergens: Retrospective Analysis From the North American Contact Dermatitis Group 2011-2014.

    Science.gov (United States)

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

    Although there are several case reports of wet wipe-associated contact dermatitis, the prevalence of wipes as a source of allergic contact dermatitis in larger populations and the responsible allergens are largely unknown. The aim of the study was to determine the prevalence of wet wipes as a source of contact allergy and the most commonly associated allergens in a North American tertiary referral patch test population. Data collected from 2011 to 2014 by the North American Contact Dermatitis Group was used to conduct a retrospective cross-sectional analysis of patient demographics and patch test results associated with the triple-digit source code for "wet wipe." Of the 9037 patients patch tested during the study period, 79 (0.9%) had a positive patch test reaction to an allergen identified with a wet wipe source. The most commonly associated allergens were preservatives, including the following: methylisothiazolinone (MI) (59.0%), methylchloroisothiazolinone (MCI)/MI (35.6%), bronopol (2-bromo-2-nitropropane-1,3-diol) (27.4%), and iodopropynyl butylcarbamate (12.3%). Fragrance (combined) represented 12.3%. Anal/genital dermatitis was 15 times more likely (P contact allergy had their contact allergens detected by the North American Contact Dermatitis Group screening series. Wet wipes are an important source of contact allergy. Preservatives are the main allergens, especially isothiazolinones.

  2. Climate variability and land cover change over the North American monsoon region (Invited)

    Science.gov (United States)

    Zeng, X.; Scheftic, W. D.; Broxton, P. D.

    2013-12-01

    The North American Monsoon System over Mexico and southwestern United States represents a weather/climate and ecosystem coupled "macrosystem". The weather and climate affect the seasonal and interannual variability of ecosystem, while the ecosystem change affects surface energy, water, and carbon fluxes that, in turn, affect weather and climate. Furthermore, long-term weather/climate data have a much coarser horizontal resolution than the satellite land cover data. Here the North American Regional Reanalysis (NARR) data at 32 km grid spacing will be combined with various satellite remote sensing products at 1 km and/or 8 km resolution from AVHRR, MODIS, and SPOT for the period of 1982 to present. Our analysis includes: a) precipitation, wind, and precipitable water data from NARR to characterize the North American monsoon; b) land cover type, normalized difference vegetation index (NDVI), green vegetation fraction, and leaf-area index (LAI) data to characterize the seasonal and interannual variability of ecosystem; c) assessing the consistency of various satellite products; and d) testing the coherence in the weather/climate and ecosystem variability.

  3. The integrated North American electricity market : Enhancing opportunities for cross border trading and environmental performance

    International Nuclear Information System (INIS)

    Egan, T.

    2003-03-01

    The stability of the North American electricity industry has always been recognized, in both Canada and the United States. However, this sector is facing uncertainty mainly due to lack of clarity concerning market rules, environmental challenges, and the very poor investment climate. The principal thesis that was developed for this paper used those three factors as context and justification. The thesis is as follows: the evolving North American market is more and more regionally integrated, and that continued and growing regional integration will lessen uncertainty. All problems cannot be solved simply through increased regional integration, but it represents a step in the right direction in that it leads to greater efficiency, increased reliability, more predictable regulation and policy, lower costs and greater environmental benefits. The result is increased investor confidence and reduced uncertainty in the marketplace. To assist in the strengthening of this integration, the Canadian Electricity Association made seven recommendations. They were: (1) increased focus on harmonizing market rules and increased participation in the Regional Transmission Organizations, (2) development of North American strategy for the management of greenhouse gas emissions resulting from electricity generation, (3) identification of oportunites to further harmonize management of other air emissions, (4) creation of consistent methodology for the measurement of environmental performance, (5) enhancement of cross-border and interprovincial transmission transfer capability, (6) coordination of critical infrastructure protection, and (7) support of self-governing international organization for the development and enforcement of mandatory reliability standards for the evolving electricity industry. 5 figs

  4. The North American iron ore industry: a decade into the 21st century

    Science.gov (United States)

    Jorgenson, John D.; Perez, A. A

    2011-01-01

    During the 20th century, the iron ore mining industries of Canada and the United States passed through periods of transformation. The beginning of the 21st century has seen another period of transformation, with the failure of a number of steel companies and with consolidation of control within the North American iron ore industry. Canadian and United States iron ore production and the market control structure involved are changing rapidly. Consolidation of ownership, formation of foreign joint ventures, divestitures of upstream activities by steelmakers, and industry changes to ensure availability of feedstocks all played a role in recent developments in the North American iron ore industry. Canadian and U.S. iron ore operations and their strong linkage to downstream production, although isolated, must also be considered within the context of the changing global economy. Projects using new technology to produce direct reduced iron nuggets of 96-98% iron content and other projects designed to produce steel at minesites may once again change the face of the iron ore industry. Social and environmental issues related to sustainable development have had a significant effect on the North American iron ore industry.

  5. Final report of the Conference on Forging North American Energy Security

    International Nuclear Information System (INIS)

    2004-06-01

    This paper discussed the main themes of the Forging American Energy Security Forum. The factors that may contribute to a potential energy crisis were identified as being the major blackout affecting the American Northeast and Ontario, political tensions in the Middle East, the volatility of oil and natural gas prices, fear of terrorist attacks on energy infrastructures and attempts to reform the Mexican energy sector. The conference addressed issues such as the reliability and physical integrity of the North American power supply grids, supply of energy at a stable and competitive price, growth of energy autonomy through increasing North American power supply and energy efficiency and the development of interconnections between power grids in the three countries. Diversification of energy supply sources was discussed, with particular reference to the increased use of renewable energies. Improvements in efficiency were suggested for how different levels of government interact on issues concerning energy development. It was recommended that the energy sector could serve as a springboard to implement a North American investment fund, and that Mexico should take advantage of its energy resources to attract foreign investors in order to finance an increase in Mexican energy production. It was suggested that a trilateral strategy aiming for energy security would accelerate national objectives. The fact that Mexico imports energy from the United States even though it already has the energy resources was also examined. Lack of capital in Mexico was seen as an impediment to development. It was concluded that relaxing regulations would facilitate in the management of the energy sector. The challenges of using clean energy sources were highlighted, as well the difficulties associated with establishing an integrated market for tradable renewable energy certificates. refs., figs

  6. Final report of the Conference on Forging North American Energy Security

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-06-01

    This paper discussed the main themes of the Forging American Energy Security Forum. The factors that may contribute to a potential energy crisis were identified as being the major blackout affecting the American Northeast and Ontario, political tensions in the Middle East, the volatility of oil and natural gas prices, fear of terrorist attacks on energy infrastructures and attempts to reform the Mexican energy sector. The conference addressed issues such as the reliability and physical integrity of the North American power supply grids, supply of energy at a stable and competitive price, growth of energy autonomy through increasing North American power supply and energy efficiency and the development of interconnections between power grids in the three countries. Diversification of energy supply sources was discussed, with particular reference to the increased use of renewable energies. Improvements in efficiency were suggested for how different levels of government interact on issues concerning energy development. It was recommended that the energy sector could serve as a springboard to implement a North American investment fund, and that Mexico should take advantage of its energy resources to attract foreign investors in order to finance an increase in Mexican energy production. It was suggested that a trilateral strategy aiming for energy security would accelerate national objectives. The fact that Mexico imports energy from the United States even though it already has the energy resources was also examined. Lack of capital in Mexico was seen as an impediment to development. It was concluded that relaxing regulations would facilitate in the management of the energy sector. The challenges of using clean energy sources were highlighted, as well the difficulties associated with establishing an integrated market for tradable renewable energy certificates. refs., figs.

  7. Effect of tropical cyclones on the stratosphere–troposphere exchange observed using satellite observations over the north Indian Ocean

    Directory of Open Access Journals (Sweden)

    M. Venkat Ratnam

    2016-07-01

    Full Text Available Tropical cyclones play an important role in modifying the tropopause structure and dynamics as well as stratosphere–troposphere exchange (STE processes in the upper troposphere and lower stratosphere (UTLS region. In the present study, the impact of cyclones that occurred over the north Indian Ocean during 2007–2013 on the STE processes is quantified using satellite observations. Tropopause characteristics during cyclones are obtained from the Global Positioning System (GPS radio occultation (RO measurements, and ozone and water vapour concentrations in the UTLS region are obtained from Aura Microwave Limb Sounder (MLS satellite observations. The effect of cyclones on the tropopause parameters is observed to be more prominent within 500 km of the centre of the tropical cyclone. In our earlier study, we observed a decrease (increase in the tropopause altitude (temperature up to 0.6 km (3 K, and the convective outflow level increased up to 2 km. This change leads to a total increase in the tropical tropopause layer (TTL thickness of 3 km within 500 km of the centre of cyclone. Interestingly, an enhancement in the ozone mixing ratio in the upper troposphere is clearly noticed within 500 km from the cyclone centre, whereas the enhancement in the water vapour in the lower stratosphere is more significant on the south-east side, extending from 500 to 1000 km away from the cyclone centre. The cross-tropopause mass flux for different intensities of cyclones is estimated and it is found that the mean flux from the stratosphere to the troposphere for cyclonic storms is 0.05 ± 0.29 × 10−3 kg m−2, and for very severe cyclonic storms it is 0.5 ± 1.07 × 10−3 kg m−2. More downward flux is noticed on the north-west and south-west side of the cyclone centre. These results indicate that the cyclones have significant impact in effecting the tropopause structure, ozone and water vapour budget, and

  8. Integrated fossil and molecular data reveal the biogeographic diversification of the eastern Asian-eastern North American disjunct hickory genus (Carya Nutt.).

    Science.gov (United States)

    Zhang, Jing-Bo; Li, Rui-Qi; Xiang, Xiao-Guo; Manchester, Steven R; Lin, Li; Wang, Wei; Wen, Jun; Chen, Zhi-Duan

    2013-01-01

    The hickory genus (Carya) contains ca. 17 species distributed in subtropical and tropical regions of eastern Asia and subtropical to temperate regions of eastern North America. Previously, the phylogenetic relationships between eastern Asian and eastern North American species of Carya were not fully confirmed even with an extensive sampling, biogeographic and diversification patterns had thus never been investigated in a phylogenetic context. We sampled 17 species of Carya and 15 species representing all other genera of the Juglandaceae as outgroups, with eight nuclear and plastid loci to reconstruct the phylogeny of Carya. The phylogenetic positions of seven extinct genera of the Juglandaceae were inferred using morphological characters and the molecular phylogeny as a backbone constraint. Divergence times within Carya were estimated with relaxed Bayesian dating. Biogeographic analyses were performed in DIVA and LAGRANGE. Diversification rates were inferred by LASER and APE packages. Our results support two major clades within Carya, corresponding to the lineages of eastern Asia and eastern North America. The split between the two disjunct clades is estimated to be 21.58 (95% HPD 11.07-35.51) Ma. Genus-level DIVA and LAGRANGE analyses incorporating both extant and extinct genera of the Juglandaceae suggested that Carya originated in North America, and migrated to Eurasia during the early Tertiary via the North Atlantic land bridge. Fragmentation of the distribution caused by global cooling in the late Tertiary resulted in the current disjunction. The diversification rate of hickories in eastern North America appeared to be higher than that in eastern Asia, which is ascribed to greater ecological opportunities, key morphological innovations, and polyploidy.

  9. Integrated fossil and molecular data reveal the biogeographic diversification of the eastern Asian-eastern North American disjunct hickory genus (Carya Nutt..

    Directory of Open Access Journals (Sweden)

    Jing-Bo Zhang

    Full Text Available The hickory genus (Carya contains ca. 17 species distributed in subtropical and tropical regions of eastern Asia and subtropical to temperate regions of eastern North America. Previously, the phylogenetic relationships between eastern Asian and eastern North American species of Carya were not fully confirmed even with an extensive sampling, biogeographic and diversification patterns had thus never been investigated in a phylogenetic context. We sampled 17 species of Carya and 15 species representing all other genera of the Juglandaceae as outgroups, with eight nuclear and plastid loci to reconstruct the phylogeny of Carya. The phylogenetic positions of seven extinct genera of the Juglandaceae were inferred using morphological characters and the molecular phylogeny as a backbone constraint. Divergence times within Carya were estimated with relaxed Bayesian dating. Biogeographic analyses were performed in DIVA and LAGRANGE. Diversification rates were inferred by LASER and APE packages. Our results support two major clades within Carya, corresponding to the lineages of eastern Asia and eastern North America. The split between the two disjunct clades is estimated to be 21.58 (95% HPD 11.07-35.51 Ma. Genus-level DIVA and LAGRANGE analyses incorporating both extant and extinct genera of the Juglandaceae suggested that Carya originated in North America, and migrated to Eurasia during the early Tertiary via the North Atlantic land bridge. Fragmentation of the distribution caused by global cooling in the late Tertiary resulted in the current disjunction. The diversification rate of hickories in eastern North America appeared to be higher than that in eastern Asia, which is ascribed to greater ecological opportunities, key morphological innovations, and polyploidy.

  10. Acculturation and smoking in North Americans of Chinese ancestry: A systematic review.

    Science.gov (United States)

    Gotay, Carolyn C; Reid, Michelle S; Dawson, Marliese Y; Wang, Shouzheng

    2015-04-30

    Many North American immigrants come from China. Given the critical impact of tobacco use on health, it is important to understand rates and correlates of smoking in this population. This systematic review addressed the question: based on current research, what is the association between acculturation and smoking behaviours in Chinese immigrants to North America? The search was conducted in PubMed, Medline, Web of Science, and Academic Search Complete for papers published from 2005 to 2014. Data were extracted from Canadian and American studies for population characteristics, study design, measures of smoking and acculturation, and findings regarding smoking rates and associations between smoking and acculturation. The literature search identified 147 articles, and 14 met inclusion criteria. Three studies were based on Canadian samples and the remaining 11 were from the United States. Of the 14 papers, 3 reported findings for youth and 11 for adults. Among adults, daily smoking rates were consistently much higher in men than women; for men, rates varied from 9% to 30%. Language use and time in North America were the most common indicators of acculturation. Almost all studies found a relationship between acculturation and smoking, such that more acculturated men smoke less and more acculturated women smoke more. The findings suggest that the association between acculturation and smoking is gender-specific. This correlation is found in youth and adults and in both Canada and the US. Increased acculturation has a protective effect on smoking for Chinese North American men, but a harmful effect for women. Tobacco control interventions need to develop targeted strategies appropriate to these different populations.

  11. Characterization of phocid herpesvirus-1 and -2 as putative alpha- and gamma-herpesviruses of North American and European pinnipeds.

    NARCIS (Netherlands)

    T.C. Harder (Timm); M. Harder; H. Vos; K. Kulonen; S. Kennedy-Stoskopf; B. Liess; M.J.G. Appel (Max); A.D.M.E. Osterhaus (Albert)

    1996-01-01

    textabstractTo study the relationships between herpesvirus recently isolated from different pinniped species, antigenic and genetic analyses were performed. First, herpesviruses isolated from North American harbour seals (Phoca vitulina), a Californian sea lion (Zalophus californianus) and a

  12. North Atlantic Tropical Cyclones: historical simulations and future changes with the new high-resolution Arpege AGCM.

    Science.gov (United States)

    Pilon, R.; Chauvin, F.; Palany, P.; Belmadani, A.

    2017-12-01

    A new version of the variable high-resolution Meteo-France Arpege atmospheric general circulation model (AGCM) has been developed for tropical cyclones (TC) studies, with a focus on the North Atlantic basin, where the model horizontal resolution is 15 km. Ensemble historical AMIP (Atmospheric Model Intercomparison Project)-type simulations (1965-2014) and future projections (2020-2080) under the IPCC (Intergovernmental Panel on Climate Change) representative concentration pathway (RCP) 8.5 scenario have been produced. TC-like vortices tracking algorithm is used to investigate TC activity and variability. TC frequency, genesis, geographical distribution and intensity are examined. Historical simulations are compared to best-track and reanalysis datasets. Model TC frequency is generally realistic but tends to be too high during the rst decade of the historical simulations. Biases appear to originate from both the tracking algorithm and model climatology. Nevertheless, the model is able to simulate extremely well intense TCs corresponding to category 5 hurricanes in the North Atlantic, where grid resolution is highest. Interaction between developing TCs and vertical wind shear is shown to be contributing factor for TC variability. Future changes in TC activity and properties are also discussed.

  13. Evaluations of Extended-Range tropical Cyclone Forecasts in the Western North Pacific by using the Ensemble Reforecasts: Preliminary Results

    Science.gov (United States)

    Tsai, Hsiao-Chung; Chen, Pang-Cheng; Elsberry, Russell L.

    2017-04-01

    The objective of this study is to evaluate the predictability of the extended-range forecasts of tropical cyclone (TC) in the western North Pacific using reforecasts from National Centers for Environmental Prediction (NCEP) Global Ensemble Forecast System (GEFS) during 1996-2015, and from the Climate Forecast System (CFS) during 1999-2010. Tsai and Elsberry have demonstrated that an opportunity exists to support hydrological operations by using the extended-range TC formation and track forecasts in the western North Pacific from the ECMWF 32-day ensemble. To demonstrate this potential for the decision-making processes regarding water resource management and hydrological operation in Taiwan reservoir watershed areas, special attention is given to the skill of the NCEP GEFS and CFS models in predicting the TCs affecting the Taiwan area. The first objective of this study is to analyze the skill of NCEP GEFS and CFS TC forecasts and quantify the forecast uncertainties via verifications of categorical binary forecasts and probabilistic forecasts. The second objective is to investigate the relationships among the large-scale environmental factors [e.g., El Niño Southern Oscillation (ENSO), Madden-Julian Oscillation (MJO), etc.] and the model forecast errors by using the reforecasts. Preliminary results are indicating that the skill of the TC activity forecasts based on the raw forecasts can be further improved if the model biases are minimized by utilizing these reforecasts.

  14. Tropical Dominance of N2 Fixation in the North Atlantic Ocean

    Science.gov (United States)

    Marconi, Dario; Sigman, Daniel M.; Casciotti, Karen L.; Campbell, Ethan C.; Alexandra Weigand, M.; Fawcett, Sarah E.; Knapp, Angela N.; Rafter, Patrick A.; Ward, Bess B.; Haug, Gerald H.

    2017-10-01

    To investigate the controls on N2 fixation and the role of the Atlantic in the global ocean's fixed nitrogen (N) budget, Atlantic N2 fixation is calculated by combining meridional nitrate fluxes across World Ocean Circulation Experiment sections with observed nitrate 15N/14N differences between northward and southward transported nitrate. N2 fixation inputs of 27.1 ± 4.3 Tg N/yr and 3.0 ± 0.5 Tg N/yr are estimated north of 11°S and 24°N, respectively. That is, 90% of the N2 fixation in the Atlantic north of 11°S occurs south of 24°N in a region with upwelling that imports phosphorus (P) in excess of N relative to phytoplankton requirements. This suggests that, under the modern iron-rich conditions of the equatorial and North Atlantic, N2 fixation occurs predominantly in response to P-bearing, N-poor conditions. We estimate a N2 fixation rate of 30.5 ± 4.9 Tg N/yr north of 30°S, implying only 3 Tg N/yr between 30° and 11°S, despite evidence of P-bearing, N-poor surface waters in this region as well; this is consistent with iron limitation of N2 fixation in the South Atlantic. Since the ocean flows through the Atlantic surface in Pacific basins.

  15. Gas fair and electricity : Speaker presentations of the 6. annual North American natural gas and electricity conference and trade fair

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    Future prospects of North American natural gas and electric utilities following deregulation, competition and restructuring have been the principal topics of the 22 papers presented at the 6. North American Natural Gas and Electricity Conference and Trade Fair. Progress in some of the major pipeline projects that will bring Canadian gas to US markets, other pipeline issues, energy financing and the impact of technology in this new era of competition also received attention. figs

  16. Changes in the North American ferroalloys industry structure and trends in the industry during the past 20 years

    Science.gov (United States)

    Didaleusky, J.R.; Jorgenson, J.D.; Corathers, L.A.; Fenton, M.D.; Kuck, P.H.; Papp, J.F.; Polyak, D.E.; Shedd, Kim B.

    2010-01-01

    This analysis of changes in the North American (Canada, Mexico, and the United States) ferroalloys industry between 1987 and 2007 includes the locations and types of ferroalloy plants in North America and the changes in production, imports, exports, pricing, and the structure of ownership since 1987, which was just prior to the implementation of the North American Free Trade Agreement. Significant events affect the supply of and demand for North American ferroalloys -- changes in end uses, global industry structure, political stability, and technology. Mergers and acquisitions in the ferroalloys industries of North America and their impact on trade are other significant issues in international trade as are antidumping and countervailing duty orders, and trade agreements and policies related to ferroalloys occurring during this period and affecting the North American region. Raw materials and energy supply to the ferroalloy industry, the logistics involved in the trade of North American ferroalloys, and the use of ferroalloys within major downstream industries are also important factors. Emphasis is placed on the bulk ferroalloys—ferrochromium, ferromanganese, ferrosilicon, and silicomanganese. Other ferroalloys investigated include those of boron, molybdenum, nickel, niobium, titanium, tungsten, and vanadium.

  17. Strategic Plan for the North American Breeding Bird Survey: 2006-2010

    Science.gov (United States)

    ,

    2007-01-01

    Executive Summary The mission of the North American Breeding Bird Survey (BBS) is to provide scientifically credible measures of the status and trends of North American bird populations at continental and regional scales to inform biologically sound conservation and management actions. Determining population trends, relative abundance, and distributions of North American avifauna is critical for identifying conservation priorities, determining appropriate conservation actions, and evaluating those actions. The BBS program, jointly coordinated by the U.S. Geological Survey and Environment Canada?s Canadian Wildlife Service, provides the U.S. and Canadian Federal governments, state and provincial agencies, other conservation practitioners, and the general public with science-based avian population trend estimates and other information for regional and national species' population assessments. Despite the demonstrated value of the BBS for furthering avian conservation across North America, its importance is often underappreciated, and it is underfunded compared with many other government-supported programs that report on status of the environment. Today, BBS resources, adjusted for inflation, are below the amount allocated in the 1970s and are still only sufficient to support two biologists. Yet the number of routes, participants, data, and data requests has quadrupled. Data and information management and delivery requirements and security concerns, non-existent in 1966, impose further demands on BBS resources. In addition, the Mexican expansion of the BBS offers new hope for a truly continental approach to avian conservation, but also brings additional challenges. Meeting the goals of this plan will take cooperation among myriad stakeholders; yet, even with collaboration, most objectives of this plan will be unattainable if BBS program support is not increased. The BBS developed this strategic plan to help set priorities and identify resources required for the

  18. Differences in Ostomy Pouch Seal Leakage Occurrences Between North American and European Residents.

    Science.gov (United States)

    Fellows, Jane; Forest Lalande, Louise; Martins, Lina; Steen, Anne; Størling, Zenia M

    The purpose of this study was to compare experiences and concerns about pouch seal leakage between persons with ostomies residing in North America (Canada and the United States) and Europe (United Kingdom, Netherlands, Sweden, Germany, Belgium, France, and Italy). Differences in reported pouch wear time and accessories used between the 2 groups were also examined. Secondary analysis of data from a cross-sectional study (Ostomy Life Study). Responses from persons residing in European countries (n = 1939) were compared with responses of 1387 individuals residing in North American countries. Persons with an ostomy completed a questionnaire that focused on 4 topics related to the daily use of an ostomy pouching system (pouch seal leakage, ballooning, appearance of pouching system such as color and size of the pouch and whether it is discrete under clothing, and coupling failure of 2-piece pouching systems). Pouch seal leakage was defined as stomal effluent seeping between the skin and the wafer of the ostomy pouching system. Statistical analysis was performed using a proportional odds model including various variable effects. Special attention was given to frequency of pouch seal leakage occurrences. All tests were 2-sided; P values ≤.05 were deemed statistically significant. Participants living in the North American countries indicated they were more likely to experience leakage from the ostomy (odds ratio = 2.610, 95% CI 2.187-3.115; P < .0001). Findings also indicated they were more likely to worry about pouch seal leakage than those in the European countries' data set (odds ratio = 2.722, 95% CI 2.283-3.246; P < .0001). Participants residing in the North American countries had significantly longer wear times than those participants in the European countries (P < .0001, χ test). The use of accessories was associated with a longer pouching system wear time. Study results suggest that participants from the North American countries indicated significantly more

  19. Identification and characterization of a RAPD-PCR marker for distinguishing Asian and North American gypsy moths

    Science.gov (United States)

    K.J. Garner; J.M. Slavicek

    1996-01-01

    The recent introduction of the Asian gypsy moth (Lymantria dispar L.) into North America has necessitated the development of genetic markers to distinguish Asian moths from the established North American population, which originated in Europe. We used RAPD-PCR to identify a DNA length polymorphism that is diagnostic for the two moth strains. The...

  20. DNA vaccine protects ornamental koi (Cyprinus carpio koi) against North American spring viremia of carp virus

    Science.gov (United States)

    Emmenegger, E.J.; Kurath, G.

    2008-01-01

    The emergence of spring viremia of carp virus (SVCV) in the United States constitutes a potentially serious alien pathogen threat to susceptible fish stocks in North America. A DNA vaccine with an SVCV glycoprotein (G) gene from a North American isolate was constructed. In order to test the vaccine a challenge model utilizing a specific pathogen-free domestic koi stock and a cold water stress treatment was also developed. We have conducted four trial studies demonstrating that the pSGnc DNA vaccine provided protection in vaccinated fish against challenge at low, moderate, and high virus doses of the homologous virus. The protection was significant (p DNA immunized fish were challenged 28-days post-vaccination (546 degree-days) and experienced low mortalities varying from 10 to 50% with relative percent survivals ranging from 50 to 88%. The non-vaccinated controls and mock construct vaccinated fish encountered high cumulative percent mortalities ranging from 70 to 100%. This is the first report of a SVCV DNA vaccine being tested successfully in koi. These experiments prove that the SVCV DNA (pSGnc) vaccine can elicit specific reproducible protection and validates its potential use as a prophylactic vaccine in koi and other vulnerable North American fish stocks.

  1. Striving for equilibrium : the changing role of storage in the North American natural gas industry

    International Nuclear Information System (INIS)

    Clifton, S.

    2003-01-01

    This presentation included an analysis of North American storage patterns and transport of natural gas. Gas-fired generation has impacted the value of storage operations significantly. The role of natural gas storage in North America is changing to meet the demands of peak-load generators, to manage tight gas supplies, and expand pipeline infrastructure. Storage facilities help in optimizing the flexibility of gas procurement. The historic role of storage was compared to the current role of storage as an economic asset. In 2002, the major developments affecting gas storage were a decline in liquidity, a decline in North American natural gas production, a recovery in forecasted gas consumption, and a capital dilemma. It is expected that the traditional role of gas storage will intensify as local distribution companies (LDCs) try to manage tight gas supplies, optimize pipeline capacity and manage price volatility. The role of storage as an economic asset will become more prominent and gas storage will be used to meet the needs of power plants. Desirable elements in future storage include a good location, high flexible performance, environmentally secure, and easy to use. The Stagecoach storage facility was presented as a case study. 1 tab., 14 figs

  2. Emergence of the North American center of excellence for transportation equipment

    Directory of Open Access Journals (Sweden)

    Richard Gottschall

    2017-07-01

    Full Text Available Following the closure of Plattsburgh Air Force Base in 1995, the northeastern region of New York State faced a unique economic development challenge. In addition to the loss of the air base, the rural area suffers from urbanization and automation in manufacturing trends. While the quality of life is highly rated, population and job growth stagnate. Isolated geographically by Lake Champlain to the East, the Adirondack Mountains to the South and West, and long distances to southern economic centers in the state, the region has looked north of the Canadian border and positioned itself as "Montreal's US suburb". Economic developers have crafted bi-national agreements between regional organizations, improved cross-border infrastructure, and enhanced educational institutions for the purpose of attracting Canadian and international manufacturers to the region. In 2015, the North American Center of Excellence in Transportation Equipment was launched and six new companies joined the cluster, doubling its size and perhaps providing a base for further growth. Manufacturing jobs are likely to grow for the first time in more than 20-years. We use cluster theory to argue that this formation of companies may still be insufficient to catalyze cluster emergence and the desired goal of regional competitiveness. Moving forward in the crafting of regional economic development policy, we emphasize the importance of viewing the North American Center of Excellence for Transportation Equipment as a pre-emergent cluster in need of further support to reach its potential.

  3. Implications of the permanent El Niño teleconnection "blueprint" for past global and North American hydroclimatology

    Directory of Open Access Journals (Sweden)

    A. Goldner

    2011-07-01

    Full Text Available Substantial evidence exists for wetter-than-modern continental conditions in North America during the pre-Quaternary warm climate intervals. This is in apparent conflict with the robust global prediction for future climate change of a northward expansion of the subtropical dry zones that should drive aridification of many semiarid regions. Indeed, areas of expected future aridification include much of western North America, where extensive paleoenvironmental records are documented to have been much wetter before the onset of Quaternary ice ages. It has also been proposed that climates previous to the Quaternary may have been characterized as being in a state with warmer-than-modern eastern equatorial sea surface temperatures (SSTs. Because equatorial Pacific SSTs exert strong controls on midlatitude atmospheric circulation and the global hydrologic cycle, the teleconnected response from this permanent El Niño-like mean state has been proposed as a useful analogue model, or "blueprint", for understanding global climatological anomalies in the past. The present study quantitatively explores the implications of this blueprint for past climates with a specific focus on the Miocene and Pliocene, using a global climate model (CAM3.0 and a nested high-resolution climate model (RegCM3 to study the hydrologic impacts on global and North American climate of a change in mean SSTs resembling that which occurs during modern El Niño events. We find that the global circulation response to a permanent El Niño resembles a large, long El Niño event. This state also exhibits equatorial super-rotation, which would represent a fundamental change to the tropical circulations. We also find a southward shift in winter storm tracks in the Pacific and Atlantic, which affects precipitation and temperature over the mid-latitudes. In addition, summertime precipitation increases over the majority of the continental United States. These increases in precipitation are

  4. Elevational Distribution of Flightless Ground Beetles in the Tropical Rainforests of North-Eastern Australia.

    Science.gov (United States)

    Staunton, Kyran M; Nakamura, Akihiro; Burwell, Chris J; Robson, Simon K A; Williams, Stephen E

    2016-01-01

    Understanding how the environment influences patterns of diversity is vital for effective conservation management, especially in a changing global climate. While assemblage structure and species richness patterns are often correlated with current environmental factors, historical influences may also be considerable, especially for taxa with poor dispersal abilities. Mountain-top regions throughout tropical rainforests can act as important refugia for taxa characterised by low dispersal capacities such as flightless ground beetles (Carabidae), an ecologically significant predatory group. We surveyed flightless ground beetles along elevational gradients in five different subregions within the Australian Wet Tropics World Heritage Area to investigate (1) whether the diversity and composition of flightless ground beetles are elevationally stratified, and, if so, (2) what environmental factors (other than elevation per se) are associated with these patterns. Generalised linear models and model averaging techniques were used to relate patterns of diversity to environmental factors. Unlike most taxonomic groups, flightless ground beetles increased in species richness and abundance with elevation. Additionally, each subregion consisted of relatively distinct assemblages containing a high level of regional endemic species. Species richness was most strongly and positively associated with historical and current climatic stabilities and negatively associated with severity of recent disturbance (treefalls). Assemblage composition was associated with latitude and historical and current climatic conditions. Although the results need to be interpreted carefully due to inter-correlation between historical and current climatic variables, our study is in agreement with the hypothesis that upland refugia provided stable climatic conditions since the last glacial maximum, and supported a diverse fauna of flightless beetle species. These findings are important for conservation

  5. Variability in north tropical atlantic over the last 20 000 years and holocene gulf stream activity

    International Nuclear Information System (INIS)

    Cleroux, C.

    2007-10-01

    Modern oceanographical studies shown that most of the ocean heat content in the North Atlantic Western Boundary Current region is stored in the upper 400 meters. To study past heat content and Gulf Stream activity, we performed coupled analyses of oxygen isotopic and trace elemental composition on several foraminifera species to reconstruct upper water column temperature and salinity. Calcification depths of Globorotalia inflata, Globorotalia truncatulinoides and Pulleniatina obliquiloculata have been constrain by correlating modern hydrographic data to oxygen isotopic measurement of North Atlantic core-top samples. We found that the three deep-dwelling foraminifera species have a preferred habitat at the base of the seasonal thermocline (Cleroux et al, 2007). The same set of North Atlantic core-tops has been used to define relationships between trace elemental compositions and temperature. We established calibrations between Mg/Ca ratio or Sr/Ca ratio and temperature for the three deep-dwelling foraminifera (Cleroux et al, submitted). We apply this strategy on the core MD99-2203 located off Cape Hatteras where the Gulf Stream separate from the United States coast. High-resolution surface reconstructions over the Holocene show low amplitude periodic temperature and salinity changes that could be related to NAO type mechanisms. Large hydrological changes in sub-surface reflect variations of Labrador current and Mode Water influences. Using recent studies on Mode Water formation and Gulf Stream heat advection, we interpret our results in term of ocean heat content and Gulf Stream activity. (author)

  6. Isotopic composition of nitrate in the central Arabian Sea and eastern tropical North Pacific: A tracer for mixing and nitrogen cycles

    Digital Repository Service at National Institute of Oceanography (India)

    Brandes, J.A.; Devol, A.H.; Yoshinari, T.; Jayakumar, D.A.; Naqvi, S.W.A.

    Trench. Ph.D. Thesis, Univ. of Cali- fornia, Los Angeles. -. AND I. R. KAPLAN. 1975. Isotopic fractionation of dissolved nitrate during denitrification in the eastern tropical North Pa- cific. Mar. Chem. 3: 271-299. CODISPOTI, L. A., AND J. P....-K. 1979. Geochemistry of inorganic nitrogen compounds in two marine environments: The Santa Barbara basin and the ocean off Peru. Ph.D. Thesis, Univ. of California, Los Angeles. -, AND I. R. KAPLAN. 1989. The eastern tropical Pacific as a source of 15N...

  7. A Continent-Wide Migratory Divide in North American Breeding Barn Swallows (Hirundo rustica.

    Directory of Open Access Journals (Sweden)

    Keith A Hobson

    Full Text Available Populations of most North American aerial insectivores have undergone steep population declines over the past 40 years but the relative importance of factors operating on breeding, wintering, or stopover sites remains unknown. We used archival light-level geolocators to track the phenology, movements and winter locations of barn swallows (Hirdundo rustica; n = 27 from populations across North America to determine their migratory connectivity. We identified an east-west continental migratory divide for barn swallows with birds from western regions (Washington State, USA (n = 8 and Saskatchewan, Canada (n = 5 traveling shorter distances to wintering areas ranging from Oregon to northern Colombia than eastern populations (Ontario (n = 3 and New Brunswick (n = 10, Canada which wintered in South America south of the Amazon basin. A single swallow from a stable population in Alabama shared a similar migration route to eastern barn swallows but wintered farther north in northeast Brazil indicating a potential leap frog pattern migratory among eastern birds. Six of 9 (67% birds from the two eastern populations and Alabama underwent a loop migration west of fall migration routes including around the Gulf of Mexico travelling a mean of 2,224 km and 722 km longer on spring migration, respectively. Longer migration distances, including the requirement to cross the Caribbean Sea and Gulf of Mexico and subsequent shorter sedentary wintering periods, may exacerbate declines for populations breeding in northeastern North America.

  8. Longitudinal trends in climate drive flowering time clines in North American Arabidopsis thaliana.

    Science.gov (United States)

    Samis, Karen E; Murren, Courtney J; Bossdorf, Oliver; Donohue, Kathleen; Fenster, Charles B; Malmberg, Russell L; Purugganan, Michael D; Stinchcombe, John R

    2012-06-01

    Introduced species frequently show geographic differentiation, and when differentiation mirrors the ancestral range, it is often taken as evidence of adaptive evolution. The mouse-ear cress (Arabidopsis thaliana) was introduced to North America from Eurasia 150-200 years ago, providing an opportunity to study parallel adaptation in a genetic model organism. Here, we test for clinal variation in flowering time using 199 North American (NA) accessions of A. thaliana, and evaluate the contributions of major flowering time genes FRI, FLC, and PHYC as well as potential ecological mechanisms underlying differentiation. We find evidence for substantial within population genetic variation in quantitative traits and flowering time, and putatively adaptive longitudinal differentiation, despite low levels of variation at FRI, FLC, and PHYC and genome-wide reductions in population structure relative to Eurasian (EA) samples. The observed longitudinal cline in flowering time in North America is parallel to an EA cline, robust to the effects of population structure, and associated with geographic variation in winter precipitation and temperature. We detected major effects of FRI on quantitative traits associated with reproductive fitness, although the haplotype associated with higher fitness remains rare in North America. Collectively, our results suggest the evolution of parallel flowering time clines through novel genetic mechanisms.

  9. Teleconnected ocean forcing of Western North American droughts and pluvials during the last millennium

    Science.gov (United States)

    Routson, Cody C.; Woodhouse, Connie A.; Overpeck, Jonathan T.; Betancourt, Julio L.; McKay, Nicholas P.

    2016-01-01

    Western North America (WNA) is rich in hydroclimate reconstructions, yet questions remain about the causes of decadal-to-multidecadal hydroclimate variability. Teleconnection patterns preserved in annually-resolved tree-ring reconstructed drought maps, and anomalies in a global network of proxy sea surface temperature (SST) reconstructions, were used to reassess the evidence linking ocean forcing to WNA hydroclimate variability over the past millennium. Potential forcing mechanisms of the Medieval Climate Anomaly (MCA) and individual drought and pluvial events—including two multidecadal-length MCA pluvials—were evaluated. We show strong teleconnection patterns occurred during the driest (wettest) years within persistent droughts (pluvials), implicating SSTs as a potent hydroclimate forcing mechanism. The role of the SSTs on longer timescales is more complex. Pacific teleconnection patterns show little long-term change, whereas low-resolution SST reconstructions vary over decades to centuries. While weaker than the tropical Pacific teleconnections, North Atlantic teleconnection patterns and SST reconstructions also show links to WNA droughts and pluvials, and may in part account for longer-term WNA hydroclimate changes. Nonetheless, evidence linking WNA hydroclimate to SSTs still remains sparse and nuanced—especially over long-timescales with a broader range of hydroclimatic variability than characterized during the 20th century.

  10. LEARNING FROM COMMERCIAL VERNACULAR BUILDING TYPES: A NORTH AMERICAN CASE STUDY

    Directory of Open Access Journals (Sweden)

    Stephen Verderber

    2016-07-01

    Full Text Available A substantial literature exists on commercial vernacular architecture in North America. This literature has examined everyday places and iconic building types including suburbia, roadside motels, vintage diners, fast food franchises, residential trailer parks, signage, unique commercial establishments, and shopping malls. These places and buildings are generally classified as expressions of folk vernacular culture. In response, Attention Restoration Theory, an environmental cognition perspective based in human information processing research, provided the foundation for an investigation of the food truck/ trailer and its immediate installation context within a North American case study context. Visual documentation, interviews, and archival fieldwork provided the basis for the articulation of a typology. These structures were found to express automaticity, as satisfying the timeless human preference for association with nature, a sense of psychological respite, and as a physical setting visually distinct from its larger urban environment context. Directions for future research on this topic are outlined together with insights for application by architects and urban planners.

  11. Conservation of Mexican wetlands: role of the North American Wetlands Conservation Act

    Science.gov (United States)

    Wilson, M.H.; Ryan, D.A.

    1997-01-01

    Mexico's wetlands support a tremendous biological diversity and provide significant natural resource benefits to local communities. Because they are also critical stopover and wintering grounds for much of North America's waterfowl and other migratory birds, Mexico has become an important participant in continental efforts to conserve these resources through the North American Wetlands Conservation Act. Funding from the Act has supported partnerships in a number of Mexico's priority wetlands to conduct data analyses and dissemination, mapping, environmental education, wetland restoration, development of sustainable economic alternatives for local people, and reserve planning and management. These partnerships, with the close involvement of Mexico's Federal Government authority, the Instituto Nacional de Ecologia, have advanced conservation in a uniquely Mexican model that differs from that employed in the United States and Canada.

  12. Cross-cultural similarities and differences in North Americans' geographic location judgments.

    Science.gov (United States)

    Friedman, Alinda; Kerkman, Dennis D; Brown, Norman R; Stea, David; Cappello, Hector M

    2005-12-01

    We examined some potential causes of bias in geographic location estimates by comparing location estimates of North American cities made by Canadian, U.S., and Mexican university students. All three groups placed most Mexican cities near the equator, which implies that all three groups were influenced by shared beliefs about the locations of geographical regions relative to global reference points. However, the groups divided North America into different regions and differed in the relative accuracy of the estimates within them, which implies that there was an influence of culture-specific knowledge. The data support a category-based system of plausible reasoning, in which biases in judgments are multiply determined, and underscore the utility of the estimation paradigm as a tool in cross-cultural cognitive research.

  13. The North American opinion climate for nanotechnology and its products: Opportunities and challenges

    International Nuclear Information System (INIS)

    Priest, Susanna

    2006-01-01

    A January 2005 telephone survey of 1200 people in the U.S. and 2000 Canadians provides a snapshot of current North American opinion regarding nanotechnology at this crucial early point in its emergence from the laboratory to the arena of public discourse and public understanding. Using a typology of 'publics' developed through analysis of a previous comparative survey (Priest, S., 2006) and subsequently tested against these newer data (Priest, S., 2005) this article describes the opinion climate for nanotechnology across North America. The comparison of key results from the two countries helps illustrate how social and cultural differences contribute to reactions to new technologies, including nanotech. The article also discusses implications for nanotechnology-related public outreach and risk communication efforts

  14. North American nuclear maintenance best practices compared to Japanese utility maintenance practices

    International Nuclear Information System (INIS)

    Harazim, M.L.; Ferguson, B.J.

    2003-01-01

    The purpose of this paper is to compare the best practices in North America concerning Preventive Maintenance, Predictive Maintenance and Reliability Centered Maintenance (RCM) or Preventive Maintenance Optimization (PMO) with the time-directed maintenance philosophies utilized by Japanese utilities, and how the Japanese utilities are considering (and some have begun) adopting North American ways of doing business. Preventive Maintenance Living Programs are also discussed, along with the Institute of Nuclear Power Operations AP-913 process, Equipment Reliability Process. Also, a cost benefit analysis will be demonstrated showing how major cost savings can be achieved by shifting from a predominantly time-directed maintenance philosophy to a predominantly predictive strategy utilizing vibration analysis, lubricating oil analysis, thermography and other predictive technologies to better utilize resources, reduce spare part consumption and to minimize maintenance induced errors. As a result of the strides made while incorporating these new philosophies, we no longer advocate tearing apart perfectly good equipment. (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. Quantifying the extent of North American mammal extinction relative to the pre-anthropogenic baseline.

    Science.gov (United States)

    Carrasco, Marc A; Barnosky, Anthony D; Graham, Russell W

    2009-12-16

    Earth has experienced five major extinction events in the past 450 million years. Many scientists suggest we are now witnessing a sixth, driven by human impacts. However, it has been difficult to quantify the real extent of the current extinction episode, either for a given taxonomic group at the continental scale or for the worldwide biota, largely because comparisons of pre-anthropogenic and anthropogenic biodiversity baselines have been unavailable. Here, we compute those baselines for mammals of temperate North America, using a sampling-standardized rich fossil record to reconstruct species-area relationships for a series of time slices ranging from 30 million to 500 years ago. We show that shortly after humans first arrived in North America, mammalian diversity dropped to become at least 15%-42% too low compared to the "normal" diversity baseline that had existed for millions of years. While the Holocene reduction in North American mammal diversity has long been recognized qualitatively, our results provide a quantitative measure that clarifies how significant the diversity reduction actually was. If mass extinctions are defined as loss of at least 75% of species on a global scale, our data suggest that North American mammals had already progressed one-fifth to more than halfway (depending on biogeographic province) towards that benchmark, even before industrialized society began to affect them. Data currently are not available to make similar quantitative estimates for other continents, but qualitative declines in Holocene mammal diversity are also widely recognized in South America, Eurasia, and Australia. Extending our methodology to mammals in these areas, as well as to other taxa where possible, would provide a reasonable way to assess the magnitude of global extinction, the biodiversity impact of extinctions of currently threatened species, and the efficacy of conservation efforts into the future.

  17. Quantifying the extent of North American mammal extinction relative to the pre-anthropogenic baseline.

    Directory of Open Access Journals (Sweden)

    Marc A Carrasco

    2009-12-01

    Full Text Available Earth has experienced five major extinction events in the past 450 million years. Many scientists suggest we are now witnessing a sixth, driven by human impacts. However, it has been difficult to quantify the real extent of the current extinction episode, either for a given taxonomic group at the continental scale or for the worldwide biota, largely because comparisons of pre-anthropogenic and anthropogenic biodiversity baselines have been unavailable. Here, we compute those baselines for mammals of temperate North America, using a sampling-standardized rich fossil record to reconstruct species-area relationships for a series of time slices ranging from 30 million to 500 years ago. We show that shortly after humans first arrived in North America, mammalian diversity dropped to become at least 15%-42% too low compared to the "normal" diversity baseline that had existed for millions of years. While the Holocene reduction in North American mammal diversity has long been recognized qualitatively, our results provide a quantitative measure that clarifies how significant the diversity reduction actually was. If mass extinctions are defined as loss of at least 75% of species on a global scale, our data suggest that North American mammals had already progressed one-fifth to more than halfway (depending on biogeographic province towards that benchmark, even before industrialized society began to affect them. Data currently are not available to make similar quantitative estimates for other continents, but qualitative declines in Holocene mammal diversity are also widely recognized in South America, Eurasia, and Australia. Extending our methodology to mammals in these areas, as well as to other taxa where possible, would provide a reasonable way to assess the magnitude of global extinction, the biodiversity impact of extinctions of currently threatened species, and the efficacy of conservation efforts into the future.

  18. Natural Selection and Origin of a Melanistic Allele in North American Gray Wolves.

    Science.gov (United States)

    Schweizer, Rena M; Durvasula, Arun; Smith, Joel; Vohr, Samuel H; Stahler, Daniel R; Galaverni, Marco; Thalmann, Olaf; Smith, Douglas W; Randi, Ettore; Ostrander, Elaine A; Green, Richard E; Lohmueller, Kirk E; Novembre, John; Wayne, Robert K

    2018-05-01

    Pigmentation is often used to understand how natural selection affects genetic variation in wild populations since it can have a simple genetic basis, and can affect a variety of fitness-related traits (e.g., camouflage, thermoregulation, and sexual display). In gray wolves, the K locus, a β-defensin gene, causes black coat color via a dominantly inherited KB allele. The allele is derived from dog-wolf hybridization and is at high frequency in North American wolf populations. We designed a DNA capture array to probe the geographic origin, age, and number of introgression events of the KB allele in a panel of 331 wolves and 20 dogs. We found low diversity in KB, but not ancestral ky, wolf haplotypes consistent with a selective sweep of the black haplotype across North America. Further, North American wolf KB haplotypes are monophyletic, suggesting that a single adaptive introgression from dogs to wolves most likely occurred in the Northwest Territories or Yukon. We use a new analytical approach to date the origin of the KB allele in Yukon wolves to between 1,598 and 7,248 years ago, suggesting that introgression with early Native American dogs was the source. Using population genetic simulations, we show that the K locus is undergoing natural selection in four wolf populations. We find evidence for balancing selection, specifically in Yellowstone wolves, which could be a result of selection for enhanced immunity in response to distemper. With these data, we demonstrate how the spread of an adaptive variant may have occurred across a species' geographic range.

  19. The status of evolutionary medicine education in North American medical schools.

    Science.gov (United States)

    Hidaka, Brandon H; Asghar, Anila; Aktipis, C Athena; Nesse, Randolph M; Wolpaw, Terry M; Skursky, Nicole K; Bennett, Katelyn J; Beyrouty, Matthew W; Schwartz, Mark D

    2015-03-08

    Medical and public health scientists are using evolution to devise new strategies to solve major health problems. But based on a 2003 survey, medical curricula may not adequately prepare physicians to evaluate and extend these advances. This study assessed the change in coverage of evolution in North American medical schools since 2003 and identified opportunities for enriching medical education. In 2013, curriculum deans for all North American medical schools were invited to rate curricular coverage and perceived importance of 12 core principles, the extent of anticipated controversy from adding evolution, and the usefulness of 13 teaching resources. Differences between schools were assessed by Pearson's chi-square test, Student's t-test, and Spearman's correlation. Open-ended questions sought insight into perceived barriers and benefits. Despite repeated follow-up, 60 schools (39%) responded to the survey. There was no evidence of sample bias. The three evolutionary principles rated most important were antibiotic resistance, environmental mismatch, and somatic selection in cancer. While importance and coverage of principles were correlated (r = 0.76, P evolutionary principles were covered by 4 to 74% more schools. Nearly half (48%) of responders anticipated igniting controversy at their medical school if they added evolution to their curriculum. The teaching resources ranked most useful were model test questions and answers, case studies, and model curricula for existing courses/rotations. Limited resources (faculty expertise) were cited as the major barrier to adding more evolution, but benefits included a deeper understanding and improved patient care. North American medical schools have increased the evolution content in their curricula over the past decade. However, coverage is not commensurate with importance. At a few medical schools, anticipated controversy impedes teaching more evolution. Efforts to improve evolution education in medical schools

  20. Assessing DNA Barcodes for Species Identification in North American Reptiles and Amphibians in Natural History Collections.

    Science.gov (United States)

    Chambers, E Anne; Hebert, Paul D N

    2016-01-01

    High rates of species discovery and loss have led to the urgent need for more rapid assessment of species diversity in the herpetofauna. DNA barcoding allows for the preliminary identification of species based on sequence divergence. Prior DNA barcoding work on reptiles and amphibians has revealed higher biodiversity counts than previously estimated due to cases of cryptic and undiscovered species. Past studies have provided DNA barcodes for just 14% of the North American herpetofauna, revealing the need for expanded coverage. This study extends the DNA barcode reference library for North American herpetofauna, assesses the utility of this approach in aiding species delimitation, and examines the correspondence between current species boundaries and sequence clusters designated by the BIN system. Sequences were obtained from 730 specimens, representing 274 species (43%) from the North American herpetofauna. Mean intraspecific divergences were 1% and 3%, while average congeneric sequence divergences were 16% and 14% in amphibians and reptiles, respectively. BIN assignments corresponded with current species boundaries in 79% of amphibians, 100% of turtles, and 60% of squamates. Deep divergences (>2%) were noted in 35% of squamate and 16% of amphibian species, and low divergences (reptiles and 23% of amphibians, patterns reflected in BIN assignments. Sequence recovery declined with specimen age, and variation in recovery success was noted among collections. Within collections, barcodes effectively flagged seven mislabeled tissues, and barcode fragments were recovered from five formalin-fixed specimens. This study demonstrates that DNA barcodes can effectively flag errors in museum collections, while BIN splits and merges reveal taxa belonging to deeply diverged or hybridizing lineages. This study is the first effort to compile a reference library of DNA barcodes for herpetofauna on a continental scale.

  1. Kokes Awards for the 23rd North American Catalysis Society Meeting

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Gary [University of Kentucky Research Foundation, Lexington, KY (United States)

    2014-01-31

    The Tri-State Catalysis Society awarded 107 Kokes Travel Awards. The program was very successful and to date this was the most Kokes Travel Awards ever awarded at a North American Catalysis Society Meeting. It provided students who merited an award the opportunity to attend the meeting, present a paper in the form of either an oral presentation or a poster presentation, and to serve the North American Catalysis Society by participating in the organization of the meeting. Students worked very hard during the week of the meeting to make it a success. Financial support for the Kokes awards was provided by DOE, NSF, NACS, as well as the Tri-State Catalysis Society, the latter through fund raising activities, and other donations. AT the meeting, each student received over $1050 in kind to offset the costs of registration fees ($260), hotel accommodations ($295.7), transportation ($400 travel allowance), as well as T-shirts ($20), and banquet tickets ($95 provided by donations from society members). In addition, for the first time, students received certificates that were signed by the President of NACS, Professor Enrique Iglesia, and by the Kokes Awards Chair, Gary Jacobs (see last page). A list of meeting co-chairs (i.e., Uschi M. Graham, Umit S. Ozkan, and Madan Bhassin) and the honorary chair (Burtron H. Davis) was also included on the certificate, along with the name of the recipient. The awardees were chosen on a merit-based guideline which also included the requirements of having a presentation accepted at the meeting and being a student at a North American University. The Richard J. Kokes Student Travel Award Committee (Gary Jacobs, Rodney Andrews, and Peter Smirniotis) with help from the Organizing Committee were able to secure money from four sources as detailed in Table 1. As detailed by our Treasurer, Dr. Helge Toufar of Clariant, the total amount spent was $105,000.

  2. Sexuality education in North American medical schools: current status and future directions.

    Science.gov (United States)

    Shindel, Alan W; Parish, Sharon J

    2013-01-01

    Both the general public and individual patients expect healthcare providers to be knowledgeable and approachable regarding sexual health. Despite this expectation there are no universal standards or expectations regarding the sexuality education of medical students. To review the current state of the art in sexuality education for North American medical students and to articulate future directions for improvement. Evaluation of: (i) peer-reviewed literature on sexuality education (focusing on undergraduate medical students); and (ii) recommendations for sexuality education from national and international public health organizations. Current status and future innovations for sexual health education in North American medical schools. Although the importance of sexuality to patients is recognized, there is wide variation in both the quantity and quality of education on this topic in North American medical schools. Many sexual health education programs in medical schools are focused on prevention of unwanted pregnancy and sexually transmitted infection. Educational material on sexual function and dysfunction, female sexuality, abortion, and sexual minority groups is generally scant or absent. A number of novel interventions, many student initiated, have been implemented at various medical schools to improve the student's training in sexual health matters. There is a tremendous opportunity to mold the next generation of healthcare providers to view healthy sexuality as a relevant patient concern. A comprehensive and uniform curriculum on human sexuality at the medical school level may substantially enhance the capacity of tomorrow's physicians to provide optimal care for their patients irrespective of gender, sexual orientation, and individual sexual mores/beliefs. © 2013 International Society for Sexual Medicine.

  3. 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.

  4. Bouguer images of the North American craton and its structural evolution

    Science.gov (United States)

    Arvidson, R. E.; Bowring, S.; Eddy, M.; Guinness, E.; Leff, C.; Bindschadler, D.

    1984-01-01

    Digital image processing techniques have been used to generate Bouguer images of the North American craton that diplay more of the granularity inherent in the data as compared with existing contour maps. A dominant NW-SE linear trend of highs and lows can be seen extending from South Dakota, through Nebraska, and into Missouri. The structural trend cuts across the major Precambrian boundary in Missouri, separating younger granites and rhyolites from older sheared granites and gneisses. This trend is probably related to features created during an early and perhaps initial episode of crustal assembly by collisional processes. The younger granitic materials are probably a thin cover over an older crust.

  5. A measurement of Omega from the North American test flight of Boomerang

    International Nuclear Information System (INIS)

    Melchiorri, A.; Ade, P.A.R.; De Bernardis, P.; Bock, J.J.; Borrill, J.; Boscaleri, A.; Crill, B.P.; De Troia, G.; Farese, P.; Ferreira, P.G.; Ganga, K.; Gasperis, G. de; Giacometti, M.; Hristov, V.V.; Jaffe, A.H.; Lange, A.E.; Masi, S.; Mauskopf, P.D.; Miglio, L.; Netterfield, C.B.; Pascale, E.; Piacentini, F.; Romeo, G.; Ruhl, J.E.; Vittorio, N.

    1999-01-01

    We use the power spectrum of the Cosmic Microwave Background, measured during the North American test flight of the BOOMERANG experiment, to constrain the geometry of the universe. Within the class of Cold Dark Matter models, we find the overall fractional energy density of the universe, Omega, is constrained to be 0.85 < or = Omega < or = 1.25 at the 68 percent confidence level. Combined with the COBE measurement and the high redshift supernovae data we obtain new constraints on the fractional matter density and the cosmological constant

  6. A measurement of $\\Omega$ from the North American test flight of BOOMERANG

    CERN Document Server

    Melchiorri, A; De Bernardis, P; Bock, J J; Borrill, J; Boscaleri, A; Crill, B P; De Troia, G; Farese, P; Ferreira, P G; Ganga, K; De Gasperis, G; Giacometti, M; Hristov, V V; Jaffe, A H; Lange, A E; Masi, S; Mauskopf, P D; Miglio, L; Netterfield, C B; Pascale, E; Piacentini, F; Romeo, G

    2000-01-01

    We use the angular power spectrum of the Cosmic Microwave Background, measured during the North American test flight of the BOOMERANG experiment, to constrain the geometry of the universe. Within the class of Cold Dark Matter models, we find that the overall fractional energy density of the universe, Omega, is constrained to be 0.85 < Omega < 1.25 at the 68% confidence level. Combined with the COBE measurement and the high redshift supernovae data we obtain new constraints on the fractional matter density and the cosmological constant.

  7. A large-scale linear complementarity model of the North American natural gas market

    International Nuclear Information System (INIS)

    Gabriel, Steven A.; Jifang Zhuang; Kiet, Supat

    2005-01-01

    The North American natural gas market has seen significant changes recently due to deregulation and restructuring. For example, third party marketers can contract for transportation and purchase of gas to sell to end-users. While the intent was a more competitive market, the potential for market power exists. We analyze this market using a linear complementarity equilibrium model including producers, storage and peak gas operators, third party marketers and four end-use sectors. The marketers are depicted as Nash-Cournot players determining supply to meet end-use consumption, all other players are in perfect competition. Results based on National Petroleum Council scenarios are presented. (Author)

  8. Continuing education needs for fishery professionals: a survey of North American fisheries administrators

    Science.gov (United States)

    Rassam, G.N.; Eisler, R.

    2001-01-01

    North American fishery professionals? continuing education needs were investigated in an American Fisheries Society questionnaire sent to 111 senior fishery officials in winter 2000. Based on a response rate of 52.2% (N = 58), a minimum of 2,967 individuals would benefit from additional training, especially in the areas of statistics and analysis (83% endorsement rate), restoration and enhancement (81%), population dynamics (81%), multi-species interactions (79%), and technical writing (79%). Other skills and techniques recommended by respondents included computer skills (72%), fishery modeling (69%), habitat modification (67%), watershed processes (66%), fishery management (64%), riparian and stream ecology (62%), habitat management (62%), public administration (62%), nonindigenous species (57%), and age and growth (55%). Additional comments by respondents recommended new technical courses, training in various communications skills, and courses to more effectively manage workloads.

  9. The Mechanic Eye: North American Visual Poetry in the Digital Age

    Directory of Open Access Journals (Sweden)

    Maria Goicoechea de Jorge

    2012-07-01

    Full Text Available http://dx.doi.org/10.5007/1807-9288.2012v8n1p78 This paper offers a revision of North American visual poetry from the contemporary perspective of the digital revolution. From the Native American chants to the digital poetry found on the Web, it will explore the internal drives of this sort of poetic manifestations that have endured through different time periods, aesthetic currents and cultural functions despite the various mediums employed for their production and dissemination. Digital poetry nourishes itself from previous literary traditions as well as from the multimedia convergence favored by the digital medium. We will analyze these influences, and the new reading strategies required to contextualize and make sense out of the digital work of poetry. As readers and writers reorganize their reading pacts, researchers of literature face a new challenge: the polymorphic and metamorphosing liquid text made possible by the digital language

  10. European and North American Schools of Public Health – Establishment, growth, differences and similarities

    Directory of Open Access Journals (Sweden)

    Jadranka Bozikov

    2016-06-01

    Full Text Available Unlike European Schools of Public Health, whose development was primarily influenced by the medical profession and was linked to the healthcare system, North American Schools of Public Health operate as independent academic institutions engaged in research and education of Public Health specialists. While Public Health has been recognised as a distinctive profession in USA and Canada for almost a century, in many European countries it is not recognized as such and, accordingly, there are no well-defined job positions for graduates. Similarities and differences between the European and American Schools of Public Health are reviewed and the importance of classification of core competences, responsibilities and scope of knowledge required for Public Health practice was pointed out as a prerequisite for accreditation of study curricula. For the professionalization of Public Health in Europe further efforts are needed.

  11. Evaluation of harvest and information needs for North American sea ducks

    Science.gov (United States)

    Koneff, Mark D.; Zimmerman, Guthrie S.; Dwyer, Chris P.; Fleming, Kathleen K.; Padding, Paul I.; Devers, Patrick K.; Johnson, Fred A.; Runge, Michael C.; Roberts, Anthony J.

    2017-01-01

    Wildlife managers routinely seek to establish sustainable limits of sport harvest or other regulated forms of take while confronted with considerable uncertainty. A growing body of ecological research focuses on methods to describe and account for uncertainty in management decision-making and to prioritize research and monitoring investments to reduce the most influential uncertainties. We used simulation methods incorporating measures of demographic uncertainty to evaluate risk of overharvest and prioritize information needs for North American sea ducks (Tribe Mergini). Sea ducks are popular game birds in North America, yet they are poorly monitored and their population dynamics are poorly understood relative to other North American waterfowl. There have been few attempts to assess the sustainability of harvest of North American sea ducks, and no formal harvest strategy exists in the U.S. or Canada to guide management. The popularity of sea duck hunting, extended hunting opportunity for some populations (i.e., special seasons and/or bag limits), and population declines have led to concern about potential overharvest. We used Monte Carlo simulation to contrast estimates of allowable harvest and observed harvest and assess risk of overharvest for 7 populations of North American sea ducks: the American subspecies of common eider (Somateria mollissima dresseri), eastern and western populations of black scoter (Melanitta americana) and surf scoter (M. perspicillata), and continental populations of white-winged scoter (M. fusca) and long-tailed duck (Clangula hyemalis). We combined information from empirical studies and the opinions of experts through formal elicitation to create probability distributions reflecting uncertainty in the individual demographic parameters used in this assessment. Estimates of maximum growth (rmax), and therefore of allowable harvest, were highly uncertain for all populations. Long-tailed duck and American common eider appeared to be at high

  12. Evaluation of harvest and information needs for North American sea ducks.

    Directory of Open Access Journals (Sweden)

    Mark D Koneff

    Full Text Available Wildlife managers routinely seek to establish sustainable limits of sport harvest or other regulated forms of take while confronted with considerable uncertainty. A growing body of ecological research focuses on methods to describe and account for uncertainty in management decision-making and to prioritize research and monitoring investments to reduce the most influential uncertainties. We used simulation methods incorporating measures of demographic uncertainty to evaluate risk of overharvest and prioritize information needs for North American sea ducks (Tribe Mergini. Sea ducks are popular game birds in North America, yet they are poorly monitored and their population dynamics are poorly understood relative to other North American waterfowl. There have been few attempts to assess the sustainability of harvest of North American sea ducks, and no formal harvest strategy exists in the U.S. or Canada to guide management. The popularity of sea duck hunting, extended hunting opportunity for some populations (i.e., special seasons and/or bag limits, and population declines have led to concern about potential overharvest. We used Monte Carlo simulation to contrast estimates of allowable harvest and observed harvest and assess risk of overharvest for 7 populations of North American sea ducks: the American subspecies of common eider (Somateria mollissima dresseri, eastern and western populations of black scoter (Melanitta americana and surf scoter (M. perspicillata, and continental populations of white-winged scoter (M. fusca and long-tailed duck (Clangula hyemalis. We combined information from empirical studies and the opinions of experts through formal elicitation to create probability distributions reflecting uncertainty in the individual demographic parameters used in this assessment. Estimates of maximum growth (rmax, and therefore of allowable harvest, were highly uncertain for all populations. Long-tailed duck and American common eider appeared

  13. Current oil and gas production from North American Upper Cretaceous chalks

    Science.gov (United States)

    Scholle, Peter A.

    1977-01-01

    Production of oil and natural gas from North American chalks has increased significantly during the past five years, spurred by the prolific production from North Sea chalks, as well as by higher prices and improved production technology. Chalk reservoirs have been discovered in the Gulf Coast in the Austin Group, Saratoga and Annona Chalks, Ozan Formation, Selma Group, Monroe gas rock (an informal unit of Navarro age), and other Upper Cretaceous units. In the Western Interior, production has been obtained from the Cretaceous Niobrara and Greenhorn Formations. Significant, though subcommercial, discoveries of natural gas and gas condensate also have been made in the Upper Cretaceous Wyandot Formation on the Scotian Shelf of eastern Canada. All North American chalk units share a similar depositional and diagenetic history. The chalks consist primarily of whole and fragmented coccoliths with subordinate planktonic and benthonic Foraminifera, inoceramid prisms, oysters, and other skeletal grains. Most have between 10 and 35 percent HCl-insoluble residue, predominantly clay. Deposition was principally below wave base in tens to hundreds of meters of water. The diagenetic history of a chalk is critical in determining its reservoir potential. All chalk has a stable composition (low-Mg calcite) and very high primary porosity. With subsequent burial, mechanical and chemical (solution-transfer) compaction can reduce or completely eliminate pore space. The degree of loss of primary porosity in chalk sections is normally a direct function of the maximum depth to which it has been buried. Pore-water chemistry, pore-fluid pressures, and tectonic stresses also influence rates of cementation. Oil or gas reservoirs of North American chalk fall into three main groups: 1. Areas with thin overburden and significant primary porosity retention (for example, Niobrara Formation of Kansas and eastern Colorado). 2. Areas with thicker overburden but considerable fracturing. Here primary

  14. Identification of three randomly amplified polymorphic DNA-polymerase chain reaction markers for distinguishing Asian and North American Gypsy Moths (Lepidoptera: Lymantriidae)

    Science.gov (United States)

    David E. Schreiber; Karen J. Garner; James M. Slavicek

    1997-01-01

    Gypsy moths originating in Asia have recently been introduced into North America, making it necessary to develop markers for distinguishing the Asian strain from the established North American population. We have identified 3 randomly amplified polymorphic DNA-polymerase chain reaction generated (RAPD-PCR) markers which are specific for either Asian or North American...

  15. Sus scrofa: Population Structure, Reproduction and Condition in Tropical North Eastern Australia

    Directory of Open Access Journals (Sweden)

    NELSON, John E.

    2009-01-01

    Full Text Available Three feral pig populations inhabiting contrasting environments along the north easterncoast of Australia have been investigated with respect to population structure, individual condition andreproduction. The population on Prince of Wales Island contains a large proportion of juvenile andsub-adult pigs but lacks pigs in the higher age classes. Individuals also breed at an earlier age thananimals of the mainland populations. Pig populations on Cape York Peninsula show a largerproportion of older animals and feral pigs living in rainforest habitats show a low proportion ofanimals in very young and very old age classes. Pigs from the lowland rainforest population are inbetter condition than those of the other populations for most of the year, reflecting the availability offood all year round in this environment. Differences in the population structure of the threepopulations are discussed with respect to fecundity and several mortality factors such as predation anddiseases/parasites.

  16. Variability and transmission by Aphis glycines of North American and Asian Soybean mosaic virus isolates.

    Science.gov (United States)

    Domier, L L; Latorre, I J; Steinlage, T A; McCoppin, N; Hartman, G L

    2003-10-01

    The variability of North American and Asian strains and isolates of Soybean mosaic virus was investigated. First, polymerase chain reaction (PCR) products representing the coat protein (CP)-coding regions of 38 SMVs were analyzed for restriction fragment length polymorphisms (RFLP). Second, the nucleotide and predicted amino acid sequence variability of the P1-coding region of 18 SMVs and the helper component/protease (HC/Pro) and CP-coding regions of 25 SMVs were assessed. The CP nucleotide and predicted amino acid sequences were the most similar and predicted phylogenetic relationships similar to those obtained from RFLP analysis. Neither RFLP nor sequence analyses of the CP-coding regions grouped the SMVs by geographical origin. The P1 and HC/Pro sequences were more variable and separated the North American and Asian SMV isolates into two groups similar to previously reported differences in pathogenic diversity of the two sets of SMV isolates. The P1 region was the most informative of the three regions analyzed. To assess the biological relevance of the sequence differences in the HC/Pro and CP coding regions, the transmissibility of 14 SMV isolates by Aphis glycines was tested. All field isolates of SMV were transmitted efficiently by A. glycines, but the laboratory isolates analyzed were transmitted poorly. The amino acid sequences from most, but not all, of the poorly transmitted isolates contained mutations in the aphid transmission-associated DAG and/or KLSC amino acid sequence motifs of CP and HC/Pro, respectively.

  17. Development of a North American paleoclimate pollen-based reconstruction database application

    Science.gov (United States)

    Ladd, Matthew; Mosher, Steven; Viau, Andre

    2013-04-01

    Recent efforts in synthesizing paleoclimate records across the globe has warranted an effort to standardize the different paleoclimate archives currently available in order to facilitate data-model comparisons and hence improve our estimates of future climate change. It is often the case that the methodology and programs make it challenging for other researchers to reproduce the results for a reconstruction, therefore there is a need for to standardize paleoclimate reconstruction databases in an application specific to proxy data. Here we present a methodology using the open source R language using North American pollen databases (e.g. NAPD, NEOTOMA) where this application can easily be used to perform new reconstructions and quickly analyze and output/plot the data. The application was developed to easily test methodological and spatial/temporal issues that might affect the reconstruction results. The application allows users to spend more time analyzing and interpreting results instead of on data management and processing. Some of the unique features of this R program are the two modules each with a menu making the user feel at ease with the program, the ability to use different pollen sums, select one of 70 climate variables available, substitute an appropriate modern climate dataset, a user-friendly regional target domain, temporal resolution criteria, linear interpolation and many other features for a thorough exploratory data analysis. The application program will be available for North American pollen-based reconstructions and eventually be made available as a package through the CRAN repository by late 2013.

  18. Reconstruction of North American drainage basins and river discharge since the Last Glacial Maximum

    Directory of Open Access Journals (Sweden)

    A. D. Wickert

    2016-11-01

    Full Text Available Over the last glacial cycle, ice sheets and the resultant glacial isostatic adjustment (GIA rearranged river systems. As these riverine threads that tied the ice sheets to the sea were stretched, severed, and restructured, they also shrank and swelled with the pulse of meltwater inputs and time-varying drainage basin areas, and sometimes delivered enough meltwater to the oceans in the right places to influence global climate. Here I present a general method to compute past river flow paths, drainage basin geometries, and river discharges, by combining models of past ice sheets, glacial isostatic adjustment, and climate. The result is a time series of synthetic paleohydrographs and drainage basin maps from the Last Glacial Maximum to present for nine major drainage basins – the Mississippi, Rio Grande, Colorado, Columbia, Mackenzie, Hudson Bay, Saint Lawrence, Hudson, and Susquehanna/Chesapeake Bay. These are based on five published reconstructions of the North American ice sheets. I compare these maps with drainage reconstructions and discharge histories based on a review of observational evidence, including river deposits and terraces, isotopic records, mineral provenance markers, glacial moraine histories, and evidence of ice stream and tunnel valley flow directions. The sharp boundaries of the reconstructed past drainage basins complement the flexurally smoothed GIA signal that is more often used to validate ice-sheet reconstructions, and provide a complementary framework to reduce nonuniqueness in model reconstructions of the North American ice-sheet complex.

  19. Providing information regarding exposures in pregnancy: a survey of North American Teratology Information Services.

    Science.gov (United States)

    Hancock, Rebecca L; Ungar, Wendy J; Einarson, Adrienne; Goodstadt, Michael; Koren, Gideon

    2008-04-01

    Teratology Information Services (TIS) provide information on exposures during pregnancy and breast-feeding. Maintaining ongoing funding is a challenge. The purpose was to gather descriptive information on current TIS operations. All North American TIS (16 American, 2 Canadian) completed a detailed survey. Service goal ranked as most important was correction of risk misperceptions. Inquiries were primarily for medications (mean 43.5%, S.D. 14.1), lactation exposures, and workplace exposures. Median employees per TIS: three (range 1-12.5). Two TIS only counsel health care professionals (HCPs). Main callers to remaining TIS were pregnant women (mean 46.8%, S.D. 22.8), physicians, and nurses. Calls per week varied (median 20, range 4-600). Median annual budget: US dollars 69,000 (range dollars 3000-335,000). Seventeen TIS collect patient data for research. This survey was the first to document TIS operations in North America and demonstrates a spectrum of clinical and research activities, and provides data for a future cost-benefit analysis of TIS.

  20. Testosterone, plumage colouration and extra-pair paternity in male North-American barn swallows.

    Directory of Open Access Journals (Sweden)

    Cas Eikenaar

    Full Text Available In most monogamous bird species, circulating testosterone concentration in males is elevated around the social female's fertile period. Variation in elevated testosterone concentrations among males may have a considerable impact on fitness. For example, testosterone implants enhance behaviours important for social and extra-pair mate choice. However, little is known about the relationship between natural male testosterone concentration and sexual selection. To investigate this relationship we measured testosterone concentration and sexual signals (ventral plumage colour and tail length, and determined within and extra-pair fertilization success in male North American barn swallows (Hirundo rustica erythrogaster. Dark rusty coloured males had higher testosterone concentrations than drab males. Extra-pair paternity was common (42% and 31% of young in 2009 and 2010, respectively, but neither within- nor extra-pair fertilization success was related to male testosterone concentration. Dark rusty males were less often cuckolded, but did not have higher extra-pair or total fertilization success than drab males. Tail length did not affect within- or extra-pair fertilization success. Our findings suggest that, in North American barn swallows, male testosterone concentration does not play a significant direct role in female mate choice and sexual selection. Possibly plumage colour co-varies with a male behavioural trait, such as aggressiveness, that reduces the chance of cuckoldry. This could also explain why dark males have higher testosterone concentrations than drab males.