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Sample records for san francisco hep

  1. Destigmatizing hepatitis B in the Asian American community: lessons learned from the San Francisco Hep B Free Campaign.

    Science.gov (United States)

    Yoo, Grace J; Fang, Ted; Zola, Janet; Dariotis, Wei Ming

    2012-03-01

    Compared to any other racial/ethnic group, Asian Americans represent a population disproportionately affected by hepatitis B virus (HBV) infection, a leading cause of liver cancer. Since 2007, the San Francisco Hep B Free (SFHBF) Campaign has been actively creating awareness and education on the importance of screening, testing, and vaccination of HBV among Asian Americans. In order to understand what messages resonated with Asian Americans in San Francisco, key informant interviews with 23 (n = 23) individuals involved in community outreach were conducted. A key finding was the ability of the SFHBF campaign to utilize unique health communication strategies to break the silence and normalize discussions of HBV. In addition, the campaign's approach to using public disclosures and motivating action by emphasizing solutions towards ending HBV proved to resonate with Asian Americans. The findings and lessons learned have implications for not only HBV but other stigmatized health issues in the Asian American community.

  2. San Francisco Accelerator Conference

    International Nuclear Information System (INIS)

    Southworth, Brian

    1991-01-01

    'Where are today's challenges in accelerator physics?' was the theme of the open session at the San Francisco meeting, the largest ever gathering of accelerator physicists and engineers

  3. San Francisco District Laboratory (SAN)

    Data.gov (United States)

    Federal Laboratory Consortium — Program CapabilitiesFood Analysis SAN-DO Laboratory has an expert in elemental analysis who frequently performs field inspections of materials. A recently acquired...

  4. San Francisco Bay Water Quality Improvement Fund

    Science.gov (United States)

    EPAs grant program to protect and restore San Francisco Bay. The San Francisco Bay Water Quality Improvement Fund (SFBWQIF) has invested in 58 projects along with 70 partners contributing to restore wetlands, water quality, and reduce polluted runoff.,

  5. ASTER Flyby of San Francisco

    Science.gov (United States)

    2002-01-01

    The Advanced Spaceborne Thermal Emission and Reflection radiometer, ASTER, is an international project: the instrument was supplied by Japan's Ministry of International Trade and Industry. A joint US/Japan science team developed algorithms for science data products, and is validating instrument performance. With its 14 spectral bands, extremely high spatial resolution, and 15 meter along-track stereo capability, ASTER is the zoom lens of the Terra satellite. The primary mission goals are to characterize the Earth's surface; and to monitor dynamic events and processes that influence habitability at human scales. ASTER's monitoring and mapping capabilities are illustrated by this series of images of the San Francisco area. The visible and near infrared image reveals suspended sediment in the bays, vegetation health, and details of the urban environment. Flying over San Francisco (3.2MB) (high-res (18.3MB)), we see the downtown, and shadows of the large buildings. Past the Golden Gate Bridge and Alcatraz Island, we cross San Pablo Bay and enter Suisun Bay. Turning south, we fly over the Berkeley and Oakland Hills. Large salt evaporation ponds come into view at the south end of San Francisco Bay. We turn northward, and approach San Francisco Airport. Rather than landing and ending our flight, we see this is as only the beginning of a 6 year mission to better understand the habitability of the world on which we live. For more information: ASTER images through Visible Earth ASTER Web Site Image courtesy of MITI, ERSDAC, JAROS, and the U.S./Japan ASTER Science Team

  6. San Francisco folio, California, Tamalpais, San Francisco, Concord, San Mateo, and Haywards quadrangles

    Science.gov (United States)

    Lawson, Andrew Cowper

    1914-01-01

    The five sheets of the San Francisco folio the Tamalpais, Ban Francisco, Concord, Ban Mateo, and Haywards sheets map a territory lying between latitude 37° 30' and 38° and longitude 122° and 122° 45'. Large parts of four of these sheets cover the waters of the Bay of San Francisco or of the adjacent Pacific Ocean. (See fig. 1.) Within the area mapped are the cities of San Francisco, Oakland, Berkeley, Alameda, Ban Rafael, and San Mateo, and many smaller towns and villages. These cities, which have a population aggregating about 750,000, together form the largest and most important center of commercial and industrial activity on the west coast of the United States. The natural advantages afforded by a great harbor, where the railways from the east meet the ships from all ports of the world, have determined the site of a flourishing cosmopolitan, commercial city on the shores of San Francisco Bay. The bay is encircled by hilly and mountainous country diversified by fertile valley lands and divides the territory mapped into two rather contrasted parts, the western part being again divided by the Golden Gate. It will therefore be convenient to sketch the geographic features under four headings (1) the area east of San Francisco Bay; (2) the San Francisco Peninsula; (3) the Marin Peninsula; (4) San Francisco Bay. (See fig. 2.)

  7. Trouble Brewing in San Francisco. Policy Brief

    Science.gov (United States)

    Buck, Stuart

    2010-01-01

    The city of San Francisco will face enormous budgetary pressures from the growing deficits in public pensions, both at a state and local level. In this policy brief, the author estimates that San Francisco faces an aggregate $22.4 billion liability for pensions and retiree health benefits that are underfunded--including $14.1 billion for the city…

  8. 78 FR 34123 - Notice of Inventory Completion: San Francisco State University NAGPRA Program, San Francisco, CA

    Science.gov (United States)

    2013-06-06

    ... completion of an inventory of human remains and associated funerary objects under the control of the San....R50000] Notice of Inventory Completion: San Francisco State University NAGPRA Program, San Francisco, CA... NAGPRA Program has completed an inventory of human remains and associated funerary objects, in...

  9. 78 FR 21403 - Notice of Inventory Completion: San Francisco State University NAGPRA Program, San Francisco, CA

    Science.gov (United States)

    2013-04-10

    ... completion of an inventory of human remains and associated funerary objects under the control of the San....R50000] Notice of Inventory Completion: San Francisco State University NAGPRA Program, San Francisco, CA... NAGPRA Program has completed an inventory of human remains and associated funerary objects, in...

  10. 76 FR 22809 - Safety Zone; Bay Ferry II Maritime Security Exercise; San Francisco Bay, San Francisco, CA

    Science.gov (United States)

    2011-04-25

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 [Docket No. USCG-2011-0196] RIN 1625-AA00 Safety Zone; Bay Ferry II Maritime Security Exercise; San Francisco Bay, San Francisco, CA AGENCY... Security Exercise; San Francisco Bay, San Francisco, CA. (a) Location. The limits of this safety zone...

  11. San Francisco Bay Interferometric Bathymetry: Area B

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — High resolution sonar data were collected over ultra-shallow areas of the San Francisco Bay estuary system. Bathymetric and acoustic backscatter data were collected...

  12. April 1906 San Francisco, USA Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 1906 San Francisco earthquake was the largest event (magnitude 8.3) to occur in the conterminous United States in the 20th Century. Recent estimates indicate...

  13. Toxic phytoplankton in San Francisco Bay

    Science.gov (United States)

    Rodgers, Kristine M.; Garrison, David L.; Cloern, James E.

    1996-01-01

    The Regional Monitoring Program (RMP) was conceived and designed to document the changing distribution and effects of trace substances in San Francisco Bay, with focus on toxic contaminants that have become enriched by human inputs. However, coastal ecosystems like San Francisco Bay also have potential sources of naturally-produced toxic substances that can disrupt food webs and, under extreme circumstances, become threats to public health. The most prevalent source of natural toxins is from blooms of algal species that can synthesize metabolites that are toxic to invertebrates or vertebrates. Although San Francisco Bay is nutrient-rich, it has so far apparently been immune from the epidemic of harmful algal blooms in the world’s nutrient-enriched coastal waters. This absence of acute harmful blooms does not imply that San Francisco Bay has unique features that preclude toxic blooms. No sampling program has been implemented to document the occurrence of toxin-producing algae in San Francisco Bay, so it is difficult to judge the likelihood of such events in the future. This issue is directly relevant to the goals of RMP because harmful species of phytoplankton have the potential to disrupt ecosystem processes that support animal populations, cause severe illness or death in humans, and confound the outcomes of toxicity bioassays such as those included in the RMP. Our purpose here is to utilize existing data on the phytoplankton community of San Francisco Bay to provide a provisional statement about the occurrence, distribution, and potential threats of harmful algae in this Estuary.

  14. 78 FR 57482 - Safety Zone; America's Cup Aerobatic Box, San Francisco Bay, San Francisco, CA

    Science.gov (United States)

    2013-09-19

    ...-AA00 Safety Zone; America's Cup Aerobatic Box, San Francisco Bay, San Francisco, CA AGENCY: Coast Guard... America's Cup air shows. These safety zones are established to provide a clear area on the water for... announced by America's Cup Race Management. ADDRESSES: Documents mentioned in this preamble are part of...

  15. 75 FR 27432 - Security Zone; Golden Guardian 2010 Regional Exercise; San Francisco Bay, San Francisco, CA

    Science.gov (United States)

    2010-05-17

    ... can better evaluate its effects on them and participate in the rulemaking process. Small businesses... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 [Docket No. USCG-2010-0221] RIN 1625-AA87 Security Zone; Golden Guardian 2010 Regional Exercise; San Francisco Bay, San Francisco, CA AGENCY...

  16. San Francisco Bay Long Term Management Strategy for Dredging

    Science.gov (United States)

    The San Francisco Bay Long Term Management Strategy (LTMS) is a cooperative effort to develop a new approach to dredging and dredged material disposal in the San Francisco Bay area. The LTMS serves as the Regional Dredging Team for the San Francisco area.

  17. Enhanced Preliminary Assessment Report: Presidio of San Francisco Military Reservation, San Francisco, California

    Science.gov (United States)

    1989-11-01

    CAD981415656 Filmore Steiner Bay San Francisco 24 PG&E Gas Plant SanFran 502-IG CAD981415714 Bay North Point Buchanan Laguna 25 PG&E Gas Plant SanFran 502-1H...76-ioV /5,JO /0.7 /,230 PSF Water PSF, Main U.N. Lagunda Honda Analvte Plant Clearwell Reservoir Plaza Reservoi- Chlordane inetab. ə.2 ə.2 (1.2 ə.2

  18. An overview of San Francisco Bay PORTS

    Science.gov (United States)

    Cheng, Ralph T.; McKinnie, David; English, Chad; Smith, Richard E.

    1998-01-01

    The Physical Oceanographic Real-Time System (PORTS) provides observations of tides, tidal currents, and meteorological conditions in real-time. The San Francisco Bay PORTS (SFPORTS) is a decision support system to facilitate safe and efficient maritime commerce. In addition to real-time observations, SFPORTS includes a nowcast numerical model forming a San Francisco Bay marine nowcast system. SFPORTS data and nowcast numerical model results are made available to users through the World Wide Web (WWW). A brief overview of SFPORTS is presented, from the data flow originated at instrument sensors to final results delivered to end users on the WWW. A user-friendly interface for SFPORTS has been designed and implemented. Appropriate field data analysis, nowcast procedures, design and generation of graphics for WWW display of field data and nowcast results are presented and discussed. Furthermore, SFPORTS is designed to support hazardous materials spill prevention and response, and to serve as resources to scientists studying the health of San Francisco Bay ecosystem. The success (or failure) of the SFPORTS to serve the intended user community is determined by the effectiveness of the user interface.

  19. City of San Francisco, California street tree resource analysis

    Science.gov (United States)

    E.G. McPherson; J.R. Simpson; P.J. Peper; Q. Xiao

    2004-01-01

    Street trees in San Francisco are comprised of two distinct populations, those managed by the city’s Department of Public Works (DPW) and those managed by private property owners with or without the help of San Francisco’s urban forestry nonprofit, Friends of the Urban Forest (FUF). These two entities believe that the public’s investment in stewardship of San Francisco...

  20. Public Involvement and Response Plan (Community Relations Plan), Presidio of San Francisco, San Francisco, California

    Science.gov (United States)

    1992-03-01

    passenger ship destination, and tourist attraction. San Francisco’s location and cultural and recreational opportunities make it a prime tourism center...equestrians, she said. C-52 m% smm : - TUESDAY, JUNE 19,1990 * . COPYKIGHT 1*90/THE TIMES MlRkOX COMPANY /CC/1 JO PAGES P. A-l, 22, 23 Complex

  1. 75 FR 39166 - Safety Zone; San Francisco Giants Baseball Game Promotion, San Francisco, CA

    Science.gov (United States)

    2010-07-08

    ... San Francisco, CA. The fireworks display is meant for entertainment purposes. This safety zone is... National Technology Transfer and Advancement Act (NTTAA) (15 U.S.C. 272 note) directs agencies to use...), of the Instruction. This rule involves establishing, disestablishing, or changing Regulated...

  2. 77 FR 59969 - Notice of Inventory Completion: San Francisco State University, Department of Anthropology, San...

    Science.gov (United States)

    2012-10-01

    ... Inventory Completion: San Francisco State University, Department of Anthropology, San Francisco, CA... Francisco State University, NAGPRA Program (formerly in the Department of Anthropology). The human remains... State University Department of Anthropology records. In the Federal Register (73 FR 30156-30158, May 23...

  3. Microbial biogeography of San Francisco Bay sediments

    Science.gov (United States)

    Lee, J. A.; Francis, C. A.

    2014-12-01

    The largest estuary on the west coast of North America, San Francisco Bay is an ecosystem of enormous biodiversity, and also enormous human impact. The benthos has experienced dredging, occupation by invasive species, and over a century of sediment input as a result of hydraulic mining. Although the Bay's great cultural and ecological importance has inspired numerous surveys of the benthic macrofauna, to date there has been almost no investigation of the microbial communities on the Bay floor. An understanding of those microbial communities would contribute significantly to our understanding of both the biogeochemical processes (which are driven by the microbiota) and the physical processes (which contribute to microbial distributions) in the Bay. Here, we present the first broad survey of bacterial and archaeal taxa in the sediments of the San Francisco Bay. We conducted 16S rRNA community sequencing of bacteria and archaea in sediment samples taken bimonthly for one year, from five sites spanning the salinity gradient between Suisun and Central Bay, in order to capture the effect of both spatial and temporal environmental variation on microbial diversity. From the same samples we also conducted deep sequencing of a nitrogen-cycling functional gene, nirS, allowing an assessment of evolutionary diversity at a much finer taxonomic scale within an important and widespread functional group of bacteria. We paired these sequencing projects with extensive geochemical metadata as well as information about macrofaunal distribution. Our data reveal a diversity of distinct biogeographical patterns among different taxa: clades ubiquitous across sites; clades that respond to measurable environmental drivers; and clades that show geographical site-specificity. These community datasets allow us to test the hypothesis that salinity is a major driver of both overall microbial community structure and community structure of the denitrifying bacteria specifically; and to assess

  4. Developing solar power programs : San Francisco's experience

    International Nuclear Information System (INIS)

    Schwartz, F.

    2006-01-01

    This keynote address discussed an array of solar programs initiated in government-owned buildings in San Francisco. The programs were strongly supported by the city's mayor,and the voting public. Known for its fog and varying microclimates, 11 monitoring stations were set up throughout the city to determine viable locations for the successful application of solar technologies. It was observed that 90 per cent of the available sunshine occurred in the central valley, whereas fog along the Pacific shore was problematic. Seven of the monitoring sites showed excellent results. Relationships with various city departments were described, as well as details of study loads, load profiles, electrical systems, roofs and the structural capabilities of the selected government buildings. There was a focus on developing good relations with the local utility. The Moscone Convention Center was selected for the program's flagship installation, a 675 kW solar project which eventually won the US EPA Green Power Award for 2004 and received high press coverage. Cost of the project was $4.2 million. 825,000 kWh solar electricity was generated, along with 4,500,000 kWh electricity saved annually from efficiency measures, resulting in a net reduction of 5,325,000 kWh. Savings on utilities bills for the center were an estimated $1,078,000. A pipeline of solar projects followed, with installations at a sewage treatment plant and a large recycling depot. A program of smaller sites included libraries, schools and health facilities. Details of plans to apply solar technology to a 500 acre redevelopment site in southeast San Francisco with an aging and inadequate electrical infrastructure were described. A model of efficient solar housing for the development was presented, with details of insulation, windows, heating ventilation and air-conditioning (HVAC), water heating, lighting, appliances and a 1.2 kilowatt solar system. Peak demand reductions were also presented. tabs., figs

  5. 77 FR 60897 - Safety Zone: America's Cup World Series Finish-Line, San Francisco, CA

    Science.gov (United States)

    2012-10-05

    ... navigable waters of the San Francisco Bay in vicinity of San Francisco West Yacht Harbor Light 2... vicinity of San Francisco West Yacht Harbor Light 2. Unauthorized persons or vessels are prohibited from... San Francisco West Yacht Harbor Light 2. This safety zone establishes a temporary restricted area on...

  6. 75 FR 65985 - Safety Zone: Epic Roasthouse Private Party Firework Display, San Francisco, CA

    Science.gov (United States)

    2010-10-27

    ... the navigable waters of San Francisco Bay 1,000 yards off Epic Roasthouse Restaurant, San Francisco.... Wright, Program Manager, Docket Operations, telephone 202-366-9826. SUPPLEMENTARY INFORMATION: Regulatory... waters of San Francisco Bay, 1,000 yards off Epic Roasthouse Restaurant, San Francisco, CA. The fireworks...

  7. San Francisco-Pacifica Coast Landslide Susceptibility 2011

    Data.gov (United States)

    California Natural Resource Agency — The San Francisco-Pacifica Coast grid map was extracted from the California Geological Survey Map Sheet 58 that covers the entire state of California and originally...

  8. San Francisco Bay Multi-beam Bathymetry: Area A

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These multi-beam bathymetric data were collected over shallow subtidal areas in the San Francisco Bay estuary system. Bathymetric and acoustic backscatter data were...

  9. San Francisco Bay Interferometric Side Scan Imagery: Area A

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Backscatter imagery data were collected over shallow subtidal areas in the San Francisco Bay estuary system. Bathymetric and acoustic backscatter data were collected...

  10. National Status and Trends: Bioeffects Program - San Francisco Bay Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study was based on the sediment quality triad (SQT) approach. A stratified probabilistic sampling design was utilized to characterize the San Francisco Bay...

  11. San Francisco Bay, California 1 arc-second DEM

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 1-second San Francisco Bay, California Elevation Grid provides bathymetric data in ASCII raster format of 1-second resolution in geographic coordinates. This...

  12. San Francisco, California Tsunami Forecast Grids for MOST Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The San Francisco, California Forecast Model Grids provides bathymetric data strictly for tsunami inundation modeling with the Method of Splitting Tsunami (MOST)...

  13. Dos edificios administrativos, en San Francisco

    Directory of Open Access Journals (Sweden)

    Skidmore, Owings & Merrill, Arquitectos

    1964-07-01

    Full Text Available The Crown Zellerbach has been built on a large triangular plaza, at the outskirts of San Francisco. This is one of the most recent tall buildings in the city. The Wells Fargo Bank is also situated on this plaza. It is of special interest, both as regards its shape and functional organisation. It has a ground floor, where most of the mercantile activities take place, and a basement, containing a Council room; the strong rooms, with 2,500 private boxes as well as the bank's own safe; washing rooms; mechanical equipment rooms; a rest room; a bar for the employees and independent stairs. The building has a circular planform, 21.5 m in diameter and 354 m2 in area. The structure is metallic, the vertical supports are along the periphery, spaced every 1.626 m. The enclosing curtain walls are glass and anodized aluminium. The roof has radially distributed metal beams, interconnected by prefabricated concrete units, covered with copper sheeting. This bank, shaped like a hunting lodge, and finished with delicate care, contrasts sharply with the powerful volume of the Crown Zellerbach, and of other nearby buildings, and adds distinction to the plaza.Sobre una gran plaza triangular del extrarradio de San Francisco se alzan: el Crown Zellerbach, uno de sus más recientes rascacielos, y un bello pabellón independiente, el Wells Fargo Bank. El resto de la plaza es de dominio público. La originalidad, en forma y organización del segundo, ha hecho que le dediquemos la mayor atención: consta de una planta baja, en la que se desarrollan, prácticamente, todas las actividades mercantiles, y un piso inferior, en donde se distribuyen: un Salón de Consejos, el departamento de cajas de seguridad, con 2.500 unidades, y las cajas del Banco, los aseos, equipos mecánicos, etc., una sala de descanso y bar para los empleados, con escalera de acceso independiente. Tiene planta circular, de 21,5 m de diámetro y 354 m2 de superficie. La estructura es metálica, con

  14. San Francisco Bay Water Quality Improvement Fund Project Locations, San Francisco CA, 2017, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — The San Francisco Bay Water Quality Improvement Fund is a competitive grant program that is helping implement TMDLs to improve water quality, protect wetlands, and...

  15. San Francisco Bay Water Quality Improvement Fund Map Service, San Francisco CA, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — The San Francisco Bay Water Quality Improvement Fund is a competitive grant program that is helping implement TMDLs to improve water quality, protect wetlands, and...

  16. San Francisco Bay Area Baseline Trash Loading Summary Results, San Francisco Bay Area CA, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — The San Francisco Bay Area stormwater permit sets trash control guidelines for discharges through the storm drain system. The permit covers Alameda, Contra Costa,...

  17. 2010 Northern San Francisco Bay Area Lidar: Portions of Alameda, Contra Costa, Marin, Napa, San Francisco, Solano, and Sonoma Counties

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Light Detection and Ranging (LiDAR) dataset is a survey of northern San Francisco Bay, California. The project area consists of approximately 437 square miles...

  18. Mercury in San Francisco Bay forage fish

    Energy Technology Data Exchange (ETDEWEB)

    Greenfield, Ben K., E-mail: ben@sfei.or [San Francisco Estuary Institute, 7770 Pardee Lane, Oakland, CA 94621 (United States); Jahn, Andrew, E-mail: andyjahn@mac.co [1000 Riverside Drive, Ukiah, CA 95482 (United States)

    2010-08-15

    In the San Francisco Estuary, management actions including tidal marsh restoration could change fish mercury (Hg) concentrations. From 2005 to 2007, small forage fish were collected and analyzed to identify spatial and interannual variation in biotic methylmercury (MeHg) exposure. The average whole body total Hg concentration was 0.052 {mu}g g{sup -1} (wet-weight) for 457 composite samples representing 13 fish species. MeHg constituted 94% of total Hg. At a given length, Hg concentrations were higher in nearshore mudflat and wetland species (Clevelandia ios, Menidia audens, and Ilypnus gilberti), compared to species that move offshore (e.g., Atherinops affinis and Lepidogobius lepidus). Gut content analysis indicated similar diets between Atherinops affinis and Menidia audens, when sampled at the same locations. Hg concentrations were higher in sites closest to the Guadalupe River, which drains a watershed impacted by historic Hg mining. Results demonstrate that despite differences among years and fish species, nearshore forage fish exhibit consistent Hg spatial gradients. - Total mercury in estuarine forage fish varies with species, habitat, and proximity to a historic mercury mine.

  19. Trans Women Doing Sex in San Francisco.

    Science.gov (United States)

    Williams, Colin J; Weinberg, Martin S; Rosenberger, Joshua G

    2016-10-01

    This research investigates the sexuality of trans women (individuals who were assigned male status at birth who currently identify as women), by focusing on the "bodily techniques" (Crossley, 2006) they use in "doing" sexuality. The "doing sexuality" framework not only is modeled after the "doing gender" approach of West and Zimmerman (1987), but also utilizes the idea of "sexual embodiment" to emphasize the agency of trans women as they conceptualize and organize their sexuality in a socially recognized way. This is often difficult as they confront discrimination from medical and legal professionals as well as intimate partners who may find it difficult to adapt to the trans woman's atypical body and conception of gender. However, with a study group of 25 trans women from San Francisco, we found the study participants to be adept at overcoming such hurdles and developing techniques to "do" their sexuality. At the same time, we found trans women's agency constrained by the erotic habitus (Green, 2008) of the wider society. The interplay between innovation and cultural tradition provides an opportunity to fashion a more general model of "doing" sexuality.

  20. Mercury in San Francisco Bay forage fish

    International Nuclear Information System (INIS)

    Greenfield, Ben K.; Jahn, Andrew

    2010-01-01

    In the San Francisco Estuary, management actions including tidal marsh restoration could change fish mercury (Hg) concentrations. From 2005 to 2007, small forage fish were collected and analyzed to identify spatial and interannual variation in biotic methylmercury (MeHg) exposure. The average whole body total Hg concentration was 0.052 μg g -1 (wet-weight) for 457 composite samples representing 13 fish species. MeHg constituted 94% of total Hg. At a given length, Hg concentrations were higher in nearshore mudflat and wetland species (Clevelandia ios, Menidia audens, and Ilypnus gilberti), compared to species that move offshore (e.g., Atherinops affinis and Lepidogobius lepidus). Gut content analysis indicated similar diets between Atherinops affinis and Menidia audens, when sampled at the same locations. Hg concentrations were higher in sites closest to the Guadalupe River, which drains a watershed impacted by historic Hg mining. Results demonstrate that despite differences among years and fish species, nearshore forage fish exhibit consistent Hg spatial gradients. - Total mercury in estuarine forage fish varies with species, habitat, and proximity to a historic mercury mine.

  1. ASTER Images San Francisco Bay Area

    Science.gov (United States)

    2000-01-01

    These images of the San Francisco Bay region were acquired on March 3, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. Each covers an area 60 kilometers (37 miles) wide and 75 kilometers (47 miles) long. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image the Earth for the next 6 years to map and monitor the changing surface of our planet.Upper Left: The color infrared composite uses bands in the visible and reflected infrared. Vegetation is red, urban areas are gray; sediment in the bays shows up as lighter shades of blue. Thanks to the 15 meter (50-foot) spatial resolution, shadows of the towers along the Bay Bridge can be seen.Upper right: A composite of bands in the short wave infrared displays differences in soils and rocks in the mountainous areas. Even though these regions appear entirely vegetated in the visible, enough surface shows through openings in the vegetation to allow the ground to be imaged.Lower left: This composite of multispectral thermal bands shows differences in urban materials in varying colors. Separation of materials is due to differences in thermal emission properties, analogous to colors in the visible.Lower right: This is a color coded temperature image of water temperature, derived from the thermal bands. Warm waters are in white and yellow, colder waters are blue. Suisun Bay in the upper right is fed directly from the cold Sacramento River. As the water flows through San Pablo and San Francisco Bays on the way to the Pacific, the waters warm up.Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for

  2. San Francisco urban partnership agreement, national evaluation : exogenous factors test plan.

    Science.gov (United States)

    2011-06-01

    This report presents the test plan for collecting and analyzing exogenous factors data for the San Francisco Urban : Partnership Agreement (UPA) under the United States Department of Transportation (U.S. DOT) UPA Program. : The San Francisco UPA proj...

  3. Merchandising of cigarettes in San Francisco pharmacies: 27 years later.

    Science.gov (United States)

    Eule, B; Sullivan, M K; Schroeder, S A; Hudmon, K S

    2004-12-01

    To estimate changes since 1976 in the proportion of San Francisco pharmacies that sell cigarettes and to characterise the advertising of cigarettes and the merchandising of non-prescription nicotine replacement therapy (NRT) products in these retail establishments. 100 randomly selected San Francisco pharmacies were visited in 2003. Pharmacies were characterised based on the sale of cigarettes, advertising for cigarettes, and the merchandising of non-prescription NRT products. In 2003, 61% of pharmacies sold cigarettes, a significant decrease compared to 89% of pharmacies selling cigarettes in 1976 (p merchandise the primary known risk factor for death in the USA.

  4. Vabariigi aastapäev San Franciscos / Heino Valvur ; foto: Heino Valvur

    Index Scriptorium Estoniae

    Valvur, Heino

    2006-01-01

    veebruarikuu möödus San Franciscos Eesti Vabariigi 88. aastapäeva pühitsedes: traditsiooniliselt tähistas aastapäeva San Francisco Seenioride Klubi koosviibimisega, E.E.L.K. San Francisco koguduses peeti jumalateenistus ja koosviibimine, kus noored esitasid rahvalaule, San Francisco Eesti Selts tähistas aastapäeva 25. veebruaril aktuse ja koosviibimisega

  5. 76 FR 9709 - Water Quality Challenges in the San Francisco Bay/Sacramento-San Joaquin Delta Estuary

    Science.gov (United States)

    2011-02-22

    ... Water Quality Challenges in the San Francisco Bay/Sacramento-San Joaquin Delta Estuary AGENCY... the San Francisco Bay/ Sacramento-San Joaquin Delta Estuary (Bay Delta Estuary) in California. EPA is... programs to address recent significant declines in multiple aquatic species in the Bay Delta Estuary. EPA...

  6. Ethnicity and Phonetic Variation in a San Francisco Neighborhood

    Science.gov (United States)

    Hall-Lew, Lauren

    2009-01-01

    This dissertation advances research in sociolinguistics by analyzing phonetic variation in a majority Asian American community in San Francisco, California. As one of the first community studies focusing on Asian Americans in an urban US context, this work speaks to ongoing discussions about speaker ethnicity, phonetic variation, and regional…

  7. Auckland--New Zealand's Los Angeles or San Francisco?

    Science.gov (United States)

    Bogunovich, Dushko

    1995-01-01

    Compares Auckland (New Zealand) with San Francisco (California) in terms of topographical structure, geographic location, and urban development. Both cities contain striking similarities. Maintains that Auckland can become a world-class city renowned for its beauty if developers and government work in tandem. (MJP)

  8. Working Paper for the Revision of San Francisco's Cable Franchise.

    Science.gov (United States)

    San Francisco Public Library, CA. Video Task Force.

    Ideas are presented for the revision of San Francisco's cable franchise. The recommendations in the report are based upon national research of library and urban use of cable communications and are designed to help the city's present and future cable franchises to comply with the regulations of the Federal Communications Commission by March 31,…

  9. Solar for Your Present Home. San Francisco Bay Area Edition.

    Science.gov (United States)

    Barnaby, Charles S.; And Others

    This publication provides information about present uses of solar energy for space, water, and swimming pool heating that are practical for the San Francisco Bay area. It attempts to provide interested persons with the information needed to make decisions regarding installations of solar heating systems. The point of view taken is that any…

  10. New fault picture points toward San Francisco Bay area earthquakes

    Science.gov (United States)

    Kerr, R. A.

    1989-01-01

    Recent earthquakes and a new way of looking at faults suggest that damaging earthquakes are closing in on the San Francisco area. Earthquakes Awareness Week 1989 in northern California started off with a bang on Monday, 3 April, when a magnitude 4.8 earthquake struck 15 kilometers northeast of San Jose. The relatively small shock-its primary damage was the shattering of an air-control tower window-got the immediate attention of three U.S Geological Survey seismologists in Menlo Park near San Francisco. David Oppenheimer, William Bakun, and Allan Lindh had forecast a nearby earthquake in a just completed report, and this, they thought, might be it. 

  11. 33 CFR 165.1187 - Security Zones; Golden Gate Bridge and the San Francisco-Oakland Bay Bridge, San Francisco Bay...

    Science.gov (United States)

    2010-07-01

    ... Limited Access Areas Eleventh Coast Guard District § 165.1187 Security Zones; Golden Gate Bridge and the... Golden Gate Bridge and the San Francisco-Oakland Bay Bridge, in San Francisco Bay, California. (b... siren, radio, flashing light, or other means, the operator of a vessel shall proceed as directed. [COTP...

  12. Aggregate Settling Velocities in San Francisco Estuary Margins

    Science.gov (United States)

    Allen, R. M.; Stacey, M. T.; Variano, E. A.

    2015-12-01

    One way that humans impact aquatic ecosystems is by adding nutrients and contaminants, which can propagate up the food web and cause blooms and die-offs, respectively. Often, these chemicals are attached to fine sediments, and thus where sediments go, so do these anthropogenic influences. Vertical motion of sediments is important for sinking and burial, and also for indirect effects on horizontal transport. The dynamics of sinking sediment (often in aggregates) are complex, thus we need field data to test and validate existing models. San Francisco Bay is well studied and is often used as a test case for new measurement and model techniques (Barnard et al. 2013). Settling velocities for aggregates vary between 4*10-5 to 1.6*10-2 m/s along the estuary backbone (Manning and Schoellhamer 2013). Model results from South San Francisco Bay shoals suggest two populations of settling particles, one fast (ws of 9 to 5.8*10-4 m/s) and one slow (ws of Brand et al. 2015). While the open waters of San Francisco Bay and other estuaries are well studied and modeled, sediment and contaminants often originate from the margin regions, and the margins remain poorly characterized. We conducted a 24 hour field experiment in a channel slough of South San Francisco Bay, and measured settling velocity, turbulence and flow, and suspended sediment concentration. At this margin location, we found average settling velocities of 4-5*10-5 m/s, and saw settling velocities decrease with decreasing suspended sediment concentration. These results are consistent with, though at the low end of, those seen along the estuary center, and they suggest that the two population model that has been successful along the shoals may also apply in the margins.

  13. Microbial diversity in restored wetlands of San Francisco Bay

    Energy Technology Data Exchange (ETDEWEB)

    Theroux, Susanna [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; Hartman, Wyatt [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; He, Shaomei [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; Univ. of Wisconsin, Madison, WI (United States); Tringe, Susannah [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.

    2013-12-09

    Wetland ecosystems may serve as either a source or a sink for atmospheric carbon and greenhouse gases. This delicate carbon balance is influenced by the activity of belowground microbial communities that return carbon dioxide and methane to the atmosphere. Wetland restoration efforts in the San Francisco Bay-Delta region may help to reverse land subsidence and possibly increase carbon storage in soils. However, the effects of wetland restoration on microbial communities, which mediate soil metabolic activity and carbon cycling, are poorly studied. In an effort to better understand the underlying factors which shape the balance of carbon flux in wetland soils, we targeted the microbial communities in a suite of restored and historic wetlands in the San Francisco Bay-Delta region. Using DNA and RNA sequencing, coupled with greenhouse gas monitoring, we profiled the diversity and metabolic potential of the wetland soil microbial communities along biogeochemical and wetland age gradients. Our results show relationships among geochemical gradients, availability of electron acceptors, and microbial community composition. Our study provides the first genomic glimpse into microbial populations in natural and restored wetlands of the San Francisco Bay-Delta region and provides a valuable benchmark for future studies.

  14. Swash zone characteristics at Ocean Beach, San Francisco, CA

    Science.gov (United States)

    Erikson, L.H.; Hanes, D.M.; Barnard, P.L.; Gibbs, A.E.

    2007-01-01

    Runup data collected during the summer of 2005 at Ocean Beach, San Francisco, CA are analyzed and considered to be typical summer swash characteristics at this site. Analysis shows that the beach was dissipative with Iribarren numbers between 0.05 and 0.4 and that infragravity energy dominated. Foreshore slopes were mild between 0.01 and 0.05 with swash periods on the order of a minute. Predicted runup heights obtained with six previously developed analytical runup formulae were compared to measured extreme runup statistics. Formulations dependent on offshore wave height, foreshore slope and deep water wavelength gave reasonable results.

  15. Mercury-contaminated hydraulic mining debris in San Francisco Bay

    Science.gov (United States)

    Bouse, Robin M.; Fuller, Christopher C.; Luoma, Samuel N.; Hornberger, Michelle I.; Jaffe, Bruce E.; Smith, Richard E.

    2010-01-01

    The hydraulic gold-mining process used during the California Gold Rush and in many developing countries today contributes enormous amounts of sediment to rivers and streams. Commonly, accompanying this sediment are contaminants such as elemental mercury and cyanide used in the gold extraction process. We show that some of the mercurycontaminated sediment created by hydraulic gold mining in the Sierra Nevada, between 1852 and 1884, ended up over 250 kilometers (km) away in San Francisco Bay; an example of the far-reaching extent of contamination from such activities.

  16. Characteristics of AA amyloidosis patients in San Francisco.

    Science.gov (United States)

    Lejmi, Hiba; Jen, Kuang-Yu; Olson, Jean L; James, Sam H; Sam, Ramin

    2016-04-01

    AA amyloidosis due to subcutaneous injection of drugs of abuse has been described in the USA, but all the existing literature is from more than 20 years ago. There is more recent literature from Europe. We have observed a high incidence of AA amyloidosis in the county hospital in San Francisco. Here, we describe 24 patients who had kidney biopsy-proven AA amyloidosis from our hospital from 1998 to 2013. All the patients were thought to have AA amyloidosis from skin popping of illicit drugs after having exhausted the intravenous route. These patients with biopsy-proven AA amyloidosis were analysed further. All patients were found to have hepatitis C infection, hypertension was not common, most had advanced kidney failure, and acidosis was common as was tubulointerstitial involvement on the kidney biopsy. Other organ involvement included hepatomegaly and splenomegaly in a number of patients; direct myocardial involvement was not seen, but pulmonary hypertension, history of deep vein thrombosis and pulmonary embolism were common. The prognosis of these patients was poor. The mortality rate approached 50% 1 year after biopsy, and most of the patient needed dialysis shortly after diagnosis. Cessation of drug use seemed beneficial but rarely achievable. AA amyloidosis from skin popping is common in San Francisco. Most patients with renal involvement end up on dialysis, and mortality rates are exceedingly high. © 2015 Asian Pacific Society of Nephrology.

  17. Proceedings of the Fourth Social Aspects and Recreation Research Symposium: February 4-6, 2004, San Francisco, California

    Science.gov (United States)

    Patrick T. Tierney; Deborah J. (Tech. coords.) Chavez

    2004-01-01

    The Fourth Social Aspects and Recreation Research (SARR) Symposium was held February 4-6, 2004 in San Francisco, California at the Presidio of San Francisco, a component of Golden Gate National Recreation Area and at San Francisco State University. The theme was: Linking People to the Outdoors: Connections for Healthy Lands, People and Communities.

  18. Coastal Adaptation: The Case of Ocean Beach, San Francisco

    Science.gov (United States)

    Cheong, S.

    2012-12-01

    Coastal erosion, storms, sea-level rise, and tsunamis all lead to inundation that puts people and communities at risk. Adapting to these coastal hazards has gained increasing attention with climate change. Instead of promoting one particular strategy such as seawalls or defending against one type of hazard, scholars and practitioners encourage a combination of existing methods and strategies to promote synergistic effects. The recently published Intergovernmental Panel on Climate Change (IPCC) Special Report on climate extremes reflects this trend in the integration of disaster risk management and climate change adaptation. This paper focuses on the roles, compatibilities, and synergies of three coastal adaptation options - engineering, vegetation, and policy - in the case of Ocean Beach in San Francisco. Traditionally engineering approach and ecosystem conservation often have stood in opposition as hard shoreline structures destroy coastal habitats, worsen coastal erosion, divert ocean currents, and prevent the natural migration of shores. A natural migration of shores without structure translates into the abandonment of properties in the coastal zone, and is at odds with property rights and development. For example, policies of relocation, retreat, and insurance may not be popular given the concerns of infrastructure and coastal access. As such, engineering, natural defense, and policy can be more conflictual than complementary. Nonetheless, all these responses are used in combination in many locations. Complementarities and compatibilities, therefore, must be assessed when considering the necessity of engineering responses, natural defense capabilities, and policy options. In this light, the question is how to resolve the problem of mixed responses and short- and long-term interests and values, identify compatibilities, and generate synergies. In the case of Ocean Beach, recent erosions that endangered San Francisco's wastewater treatment system acted as major

  19. Steam, solarization, and tons of prevention: the San Francisco Public Utilities Commission's fight to contain Phytophthoras in San Francisco Bay area restoration sites

    Science.gov (United States)

    Greg Lyman; Jessica Appel; Mia Ingolia; Ellen Natesan; Joe Ortiz

    2017-01-01

    To compensate for unavoidable impacts associated with critical water infrastructure capital improvement projects, the San Francisco Public Utilities Commission (SFPUC) restored over 2,050 acres of riparian, wetland, and upland habitat on watershed lands in Alameda, Santa Clara, and San Mateo Counties. Despite strict bio-sanitation protocols, plant pathogens (...

  20. Rocks and geology in the San Francisco Bay region

    Science.gov (United States)

    Stoffer, Philip W.

    2002-01-01

    The landscape of the San Francisco Bay region is host to a greater variety of rocks than most other regions in the United States. This introductory guide provides illustrated descriptions of 46 common and important varieties of igneous, sedimentary, and metamorphic rock found in the region. Rock types are described in context of their identification qualities, how they form, and where they occur in the region. The guide also provides discussion about of regional geology, plate tectonics, the rock cycle, the significance of the selected rock types in relation to both earth history and the impact of mineral resources on the development in the region. Maps and text also provide information where rocks, fossils, and geologic features can be visited on public lands or in association with public displays in regional museums, park visitor centers, and other public facilities.

  1. Wave attenuation across a tidal marsh in San Francisco Bay

    Science.gov (United States)

    Foster-Martinez, Madeline R.; Lacy, Jessica; Ferner, Matthew C.; Variano, Evan A.

    2018-01-01

    Wave attenuation is a central process in the mechanics of a healthy salt marsh. Understanding how wave attenuation varies with vegetation and hydrodynamic conditions informs models of other marsh processes that are a function of wave energy (e.g. sediment transport) and allows for the incorporation of marshes into coastal protection plans. Here, we examine the evolution of wave height across a tidal salt marsh in San Francisco Bay. Instruments were deployed along a cross-shore transect, starting on the mudflat and crossing through zones dominated by Spartina foliosa and Salicornia pacifica. This dataset is the first to quantify wave attenuation for these vegetation species, which are abundant in the intertidal zone of California estuaries. Measurements were collected in the summer and winter to assess seasonal variation in wave attenuation. Calculated drag coefficients of S. foliosa and S. pacifica were similar, indicating equal amounts of vegetation would lead to similar energy dissipation; however, S. pacifica has much greater biomass close to the bed (<20 cm) and retains biomass throughout the year, and therefore, it causes more total attenuation. S. foliosa dies back in the winter, and waves often grow across this section of the marsh. For both vegetation types, attenuation was greatest for low water depths, when the vegetation was emergent. For both seasons, attenuation rates across S. pacifica were the highest and were greater than published attenuation rates across similar (Spartina alterniflora) salt marshes for the comparable depths. These results can inform designs for marsh restorations and management plans in San Francisco Bay and other estuaries containing these species.

  2. 77 FR 49865 - Notice of Availability of an Environmental Impact Statement (EIS) for the San Francisco Veterans...

    Science.gov (United States)

    2012-08-17

    ... National Environmental Policy Act (NEPA) of 1969, as amended, (42 U.S.C. 4331 et seq.), the Council on...) for the San Francisco Veterans Affairs Medical Center (SFVAMC) Long Range Development Plan (LRDP... Francisco Veterans Affairs Medical Center, 4150 Clement Street, San Francisco, CA 94121 or by telephone...

  3. Physical and chemical properties of San Francisco Bay waters, 1969-1976 (NODC Accession 8400194)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — One magnetic tape containing the physical and chemical properties of San Francisco Bay waters was forwarded to NODC by Mr. Richard Smith of the U.S Geological Survey...

  4. Coastal processes study at Ocean Beach, San Francisco, CA: summary of data collection 2004-2006

    Science.gov (United States)

    Barnard, Patrick L.; Eshleman, Jodi; Erikson, Li H.; Hanes, Daniel M.

    2007-01-01

    Ocean Beach in San Francisco, California, contains a persistent erosional section in the shadow of the San Francisco ebb tidal delta and south of Sloat Boulevard that threatens valuable public infrastructure as well as the safe recreational use of the beach. Coastal managers have been discussing potential mediation measures for over a decade, with little scientific research available to aid in decision making. The United States Geological Survey (USGS) initiated the Ocean Beach Coastal Processes Study in April 2004 to provide the scientific knowledge necessary for coastal managers to make informed management decisions. This study integrates a wide range of field data collection and numerical modeling techniques to document nearshore sediment transport processes at the mouth of San Francisco Bay, with emphasis on how these processes relate to erosion at Ocean Beach. The Ocean Beach Coastal Processes Study is the first comprehensive study of coastal processes at the mouth of San Francisco Bay.

  5. San Francisco urban partnership agreement, national evaluation : content analysis test plan.

    Science.gov (United States)

    2011-06-01

    This report presents the test plan for collecting and analyzing information on outreach activities, media coverage, : and reactions of the public, policy makers, and other groups to the UPA projects for the San Francisco Urban : Partnership Agreement...

  6. San Francisco Bay Area Rapid Transit District (BART) climate change adaptation assessment pilot.

    Science.gov (United States)

    2013-12-01

    The objective of this pilot study was to evaluate the impacts of climate change on the San Francisco Bay Area Rapid Transit District : (BART) infrastructure and to develop and implement adaptation strategies against those impacts. Climate change haza...

  7. San Francisco Bay Water Quality Improvement Fund Points, SF Bay CA, 2015, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — The San Francisco Bay Water Quality Improvement Fund is a competitive grant program that is helping implement TMDLs to improve water quality, protect wetlands, and...

  8. Records of contaminant input to San Francisco Bay

    International Nuclear Information System (INIS)

    Geen, A. van; Luoma, S.N.; Hornberger, M.; Fuller, C.; Pereira, W.; Hostettler, F.; Kvenvolden, K.; Anima, R.; Ritson, P.; Flegal, A.R.

    1994-01-01

    San Francisco Bay, one of the few large estuaries on the West Coast of North America, was subjected to great change as mining, agriculture, industrialization and urbanization accelerated after 1849, and river flows were diverted for agriculture. Trends in contamination were evident in sediment cores analyzed from seven sites. Sedimentation rates increased with human activities. Industrialization was a greater source of contamination than mining. Nearest the mouth of the estuary, concentrations of Hg, Cu, Zn, Pb and PAH began to increase around 1900. Isotopes of Pb indicated sediments were affected by a mixture of atmospheric, industrial and erosional inputs. Peaks in some contaminants were evident since the 1950s, notably Ag, Cd in water (as recorded in foraminifers tests), and DDT. Chromium and vanadium were naturally enriched throughout the cores. Declines in metal concentrations in surface sediments were not evident. Vertical mixing could delay response of sediments to changed metal inputs. Nearer the head of the estuary, contaminant concentrations, TOC and indicators of terrigenous carbon increased sharply where 137 Cs and 239,240 Pu was present (presumably post-1950). Diversion of river flows may have affected accumulation of sediments contaminated by post-war industrialization and acceleration of agricultural development

  9. Microbial diversity and carbon cycling in San Francisco Bay wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Theroux, Susanna [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; Hartman, Wyatt [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; He, Shaomei [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; Univ. of Wisconsin, Madison, WI (United States); Tringe, Susannah [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.

    2014-03-21

    Wetland restoration efforts in San Francisco Bay aim to rebuild habitat for endangered species and provide an effective carbon storage solution, reversing land subsidence caused by a century of industrial and agricultural development. However, the benefits of carbon sequestration may be negated by increased methane production in newly constructed wetlands, making these wetlands net greenhouse gas (GHG) sources to the atmosphere. We investigated the effects of wetland restoration on below-ground microbial communities responsible for GHG cycling in a suite of historic and restored wetlands in SF Bay. Using DNA and RNA sequencing, coupled with real-time GHG monitoring, we profiled the diversity and metabolic potential of wetland soil microbial communities. The wetland soils harbor diverse communities of bacteria and archaea whose membership varies with sampling location, proximity to plant roots and sampling depth. Our results also highlight the dramatic differences in GHG production between historic and restored wetlands and allow us to link microbial community composition and GHG cycling with key environmental variables including salinity, soil carbon and plant species.

  10. San Francisco Biofuel Program: Brown Grease to Biodiesel Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Jolis, Domènec [San Francisco Public Utilities Commission, San Francisco, CA (United States); Martis, Mary [San Francisco Public Utilities Commission, San Francisco, CA (United States); Jones, Bonnie [San Francisco Public Utilities Commission, San Francisco, CA (United States); Miot, Alex [San Francisco Public Utilities Commission, San Francisco, CA (United States); Ving, Karri [San Francisco Public Utilities Commission, San Francisco, CA (United States); Sierra, Natalie [San Francisco Public Utilities Commission, San Francisco, CA (United States); Niobi, Morayo [San Francisco Public Utilities Commission, San Francisco, CA (United States)

    2013-03-01

    Municipal wastewater treatment facilities have typically been limited to the role of accepting wastewater, treating it to required levels, and disposing of its treatment residuals. However, a new view is emerging which includes wastewater treatment facilities as regional resource recovery centers. This view is a direct result of increasingly stringent regulations, concerns over energy use, carbon footprint, and worldwide depletion of fossil fuel resources. Resources in wastewater include chemical and thermal energy, as well as nutrients, and water. A waste stream such as residual grease, which concentrates in the drainage from restaurants (referred to as Trap Waste), is a good example of a resource with an energy content that can be recovered for beneficial reuse. If left in wastewater, grease accumulates inside of the wastewater collection system and can lead to increased corrosion and pipe blockages that can cause wastewater overflows. Also, grease in wastewater that arrives at the treatment facility can impair the operation of preliminary treatment equipment and is only partly removed in the primary treatment process. In addition, residual grease increases the demand in treatment materials such as oxygen in the secondary treatment process. When disposed of in landfills, grease is likely to undergo anaerobic decay prior to landfill capping, resulting in the atmospheric release of methane, a greenhouse gas (GHG). This research project was therefore conceptualized and implemented by the San Francisco Public Utilities Commission (SFPUC) to test the feasibility of energy recovery from Trap Waste in the form of Biodiesel or Methane gas.

  11. Crustal structure of the coastal and marine San Francisco Bay region, California

    Science.gov (United States)

    Parsons, Tom

    2002-01-01

    As of the time of this writing, the San Francisco Bay region is home to about 6.8 million people, ranking fifth among population centers in the United States. Most of these people live on the coastal lands along San Francisco Bay, the Sacramento River delta, and the Pacific coast. The region straddles the tectonic boundary between the Pacific and North American Plates and is crossed by several strands of the San Andreas Fault system. These faults, which are stressed by about 4 cm of relative plate motion each year, pose an obvious seismic hazard.

  12. Edificio para ambulatorio San Francisco – (EE. UU.

    Directory of Open Access Journals (Sweden)

    Reid, John Lyon

    1976-12-01

    Full Text Available The 50,470 m2 the total area of the hospital is distributed as follows: 18,900 m2 for the 22 main clinics and for the additional clinics; 2,770 m2 for complementary activities; and the remaining 28,800 m2 for a parking lot with space for 700 cars. The building occupies a site that slopes strongly towards the north across which runs the pedestrian access from one of the circumference roads to the main façade; the access road for the vehicles leads to the back facade, where the natural slope of the ground has been taken advantage of to build the 5 storey parking building. The two main functions —the clinics and the parking house— are conveniently separated though connected with each other by means of corridors and lifts. The interior design of the clinics is very flexible so as to allow for further enlargements. The patients' waiting rooms are provided with a glazed façade and have a beautiful view over the San Francisco Bay and its surroundings. The construction is entirely of concrete and its structure is calculated ín such a manner as to allow for two additional storeys.Cuenta con una superficie total construida de 50.470 m2, repartidos de la siguiente forma: 18.900 se destinan a la distribución de 22 clínicas principales y otras secundarias; 2.770 a locales de actividades complementarias; y el resto, 28.800 m2, a aparcamiento con capacidad para 700 plazas. El edificio ocupa una parcela fuertemente inclinada hacia el norte, inclinación que permite el acceso peatonal a la clínica, por la fachada principal, desde una de las avenidas perimetrales; y el vehicular, por la fachada posterior, en donde, aprovechando el desnivel del terreno, se han organizado las cinco plantas del aparcamiento. Las dos funciones principales —clínicas y aparcamiento— se hallan convenientemente separadas, estableciéndose el enlace entre los distintos niveles mediante ascensores que relacionan las clínicas, el centro médico, los aparcamientos

  13. A Summary of the San Francisco Tidal Wetlands Restoration Series

    Directory of Open Access Journals (Sweden)

    Larry R. Brown

    2003-10-01

    Full Text Available The four topical articles of the Tidal Wetlands Restoration Series summarized and synthesized much of what is known about tidal wetlands and tidal wetland restoration in the San Francisco Estuary (hereafter “Estuary”. Despite a substantial amount of available information, major uncertainties remain. A major uncertainty with regard to fishes is the net benefit of restored tidal wetlands relative to other habitats for native fishes in different regions of the Estuary given the presence of numerous invasive alien species. With regard to organic carbon, a major uncertainty is the net benefit of land use change given uncertainty about the quantity and quality of different forms of organic carbon resulting from different land uses. A major challenge is determining the flux of organic carbon from open systems like tidal wetlands. Converting present land uses to tidal wetlands will almost certainly result in increased methylation of mercury at the local scale with associated accumulation of mercury within local food webs. However, it is unclear if such local accumulation is of concern for fish, wildlife or humans at the local scale or if cumulative effects at the regional scale will emerge. Based on available information it is expected that restored tidal wetlands will remain stable once constructed; however, there is uncertainty associated with the available data regarding the balance of sediment accretion, sea-level rise, and sediment erosion. There is also uncertainty regarding the cumulative effect of many tidal restoration projects on sediment supply. The conclusions of the articles highlight the need to adopt a regional and multidisciplinary approach to tidal wetland restoration in the Estuary. The Science Program of the CALFED effort provides an appropriate venue for addressing these issues.

  14. Psychiatric Disorders and Substance Use in Homeless Youth: A Preliminary Comparison of San Francisco and Chicago

    Directory of Open Access Journals (Sweden)

    Ernika G. Quimby

    2012-08-01

    Full Text Available Youth homelessness is a growing problem in the United States. The experience of homelessness appears to have numerous adverse consequences, including psychiatric and substance use disorders. This study compared the frequencies of psychiatric disorders, including substance use, between homeless youth (18–24 years-old in San Francisco (N = 31 and Chicago (N = 56. Subjects were administered the Mini International Neuropsychiatric Interview (M.I.N.I. to assess DSM-IV-TR diagnoses and substance use disorders. Eighty-seven percent of the San Francisco youth, and 81% of the Chicago youth met criteria for at least one M.I.N.I. psychiatric diagnosis. Nearly two-thirds of the youth in both samples met criteria for a mood disorder. Approximately one-third met criteria for an anxiety disorder. Thirty-two percent of the San Francisco sample and 18% of the Chicago met criteria for Antisocial Personality Disorder. Approximately 84% of the San Francisco youth and 48% of the Chicago youth met criteria for a substance-related disorder, and more substances were used by San Francisco youth. In conclusion, the high rate of psychiatric disorders in homeless youth provides clear evidence that the mental health needs of this population are significant. Implications are discussed.

  15. 77 FR 32716 - Price for the 2012 American Eagle San Francisco Two-Coin Silver Proof Set

    Science.gov (United States)

    2012-06-01

    ... DEPARTMENT OF THE TREASURY United States Mint Price for the 2012 American Eagle San Francisco Two...: The United States Mint is announcing the price of the 2012 American Eagle San Francisco Two-Coin Silver Proof Set. The coin set will be offered for sale at a price of $149.95. FOR FURTHER INFORMATION...

  16. 76 FR 17752 - Notice of Intent To Prepare an Environmental Impact Statement for the San Francisco Veterans...

    Science.gov (United States)

    2011-03-30

    ... Environmental Policy Act (NEPA) of 1969, as amended, (42 U.S.C. 4331 et seq.), the Council on Environmental... the San Francisco Veterans Affairs Medical Center (SFVAMC) Institutional Master Plan AGENCY...: Comments should be addressed to John Pechman, Facility Planner, San Francisco VA Medical Center (001), 4150...

  17. Health, Traffic, and Environmental Justice: Collaborative Research and Community Action in San Francisco, California

    Science.gov (United States)

    Sciammas, Charlie; Seto, Edmund; Bhatia, Rajiv; Rivard, Tom

    2009-01-01

    Health impacts on neighborhood residents from transportation systems can be an environmental justice issue. To assess the effects of transportation planning decisions, including the construction of an intraurban freeway, on residents of the Excelsior neighborhood in southeast San Francisco, PODER (People Organizing to Demand Environmental and Economic Rights), a local grassroots environmental justice organization; the San Francisco Department of Public Health; and the University of California, Berkeley, collaborated on participatory research. We used our findings regarding traffic-related exposures and health hazards in the area to facilitate community education and action to address transportation-related health burdens on neighborhood residents. PMID:19890147

  18. Anthropogenic influences on shoreline and nearshore evolution in the San Francisco Bay coastal system

    Science.gov (United States)

    Dallas, K.L.; Barnard, P.L.

    2011-01-01

    Analysis of four historical bathymetric surveys over a 132-year period has revealed significant changes to the morphology of the San Francisco Bar, an ebb-tidal delta at the mouth of San Francisco Bay estuary. From 1873 to 2005 the San Francisco Bar vertically-eroded an average of 80 cm over a 125 km2 area, which equates to a total volume loss of 100 ± 52 million m3 of fine- to coarse-grained sand. Comparison of the surveys indicates the entire ebb-tidal delta contracted radially, with the crest moving landward an average of 1 km. Long-term erosion of the ebb-tidal delta is hypothesized to be due to a reduction in the tidal prism of San Francisco Bay and a decrease in coastal sediment supply, both as a result of anthropogenic activities. Prior research indicates that the tidal prism of the estuary was reduced by 9% from filling, diking, and sedimentation. Compilation of historical records dating back to 1900 reveals that a minimum of 200 million m3 of sediment has been permanently removed from the San Francisco Bay coastal system through dredging, aggregate mining, and borrow pit mining. Of this total, ~54 million m3 of sand-sized or coarser sediment was removed from central San Francisco Bay. With grain sizes comparable to the ebb-tidal delta, and its direct connection to the bay mouth, removal of sediments from central San Francisco Bay may limit the sand supply to the delta and open coast beaches. SWAN wave modeling illustrates that changes to the morphology of the San Francisco Bar have altered the alongshore wave energy distribution at adjacent Ocean Beach, and thus may be a significant factor in a persistent beach erosion ‘hot spot’ occurring in the area. Shoreline change analyses show that the sandy shoreline in the shadow of the ebb-tidal delta experienced long-term (1850s/1890s to 2002) and short-term (1960s/1980s to 2002) accretion while the adjacent sandy shoreline exposed to open-ocean waves experienced long-term and short-term erosion. Therefore

  19. City College of San Francisco 1997 Sexual Harassment Student Opinion Survey.

    Science.gov (United States)

    City Coll. of San Francisco, CA. Office of Institutional Research, Planning and Grants.

    This document describes the findings of a 1997 sexual harassment student opinion survey conducted at City College of San Francisco. Survey questions were jointly developed by the Sexual Harassment Prevention Sub-Committee of the Diversity Advisory Committee and the Office of Research and Planning, approved by the College Advisory Council, and…

  20. 33 CFR 165.1192 - Security Zones; Waters surrounding San Francisco International Airport and Oakland International...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security Zones; Waters..., California. 165.1192 Section 165.1192 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND... Security Zones; Waters surrounding San Francisco International Airport and Oakland International Airport...

  1. 33 CFR 165.1190 - Security Zone; San Francisco Bay, Oakland Estuary, Alameda, CA.

    Science.gov (United States)

    2010-07-01

    ..., Oakland Estuary, Alameda, CA. 165.1190 Section 165.1190 Navigation and Navigable Waters COAST GUARD... § 165.1190 Security Zone; San Francisco Bay, Oakland Estuary, Alameda, CA. (a) Location. The following area is a security zone: All navigable waters of the Oakland Estuary, California, from the surface to...

  2. 33 CFR 167.405 - Off San Francisco: Main ship channel.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Off San Francisco: Main ship channel. 167.405 Section 167.405 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY OFFSHORE TRAFFIC SEPARATION SCHEMES Description of Traffic Separation Schemes and Precautionary Areas...

  3. 76 FR 55261 - Safety Zone; Corporate Party on Hornblower Yacht, San Francisco, CA

    Science.gov (United States)

    2011-09-07

    ...-AA00 Safety Zone; Corporate Party on Hornblower Yacht, San Francisco, CA AGENCY: Coast Guard, DHS... Corporate Party on Hornblower Yacht. This temporary safety zone is established to ensure the safety of... Events will sponsor the Corporate Party on Hornblower Yacht on September 17, 2011, in the navigable...

  4. The Quality Teacher and Education Act in San Francisco: Lessons Learned. Policy Brief 09-2

    Science.gov (United States)

    Hough, Heather J.

    2009-01-01

    This policy brief reviews the recent experience of the San Francisco Unified School District (SFUSD) with the development and approval of Proposition A. Proposition A (also known as the Quality Teacher and Education Act, or QTEA) included a parcel tax mainly dedicated to increasing teachers' salaries, along with a variety of measures introducing…

  5. Dogs Are Talking: San Francisco's social marketing campaign to increase syphilis screening.

    Science.gov (United States)

    Stephens, Sally C; Bernstein, Kyle T; McCright, Jacqueline E; Klausner, Jeffrey D

    2010-03-01

    To promote regular syphilis testing among men who have sex with men in San Francisco, a social marketing campaign, Dogs Are Talking, was created. An evaluation of the campaign found no difference in syphilis testing among men who recalled the campaign and those that did not. A significant difference was seen among HIV-infected men.

  6. Making Whites from the Dark Side: Teaching Whiteness Studies at San Francisco State University

    Science.gov (United States)

    Sueyoshi, Amy

    2013-01-01

    While whiteness studies at most institutions aims to expose the persistence of white supremacy to a disbelieving audience, whiteness studies within the College of Ethnic Studies (COES) at San Francisco State University (SFSU) begins with the assumption that racism still exists. The course then traces how whiteness is constructed and fortified to…

  7. 78 FR 40396 - Safety Zone; America's Cup Safety Zone and No Loitering Area, San Francisco, CA

    Science.gov (United States)

    2013-07-05

    ...-AA00 Safety Zone; America's Cup Safety Zone and No Loitering Area, San Francisco, CA AGENCY: Coast... America's Cup races. This safety zone and no loitering area are established to enhance the safety of spectators and mariners near the north east corner of the America's Cup regulated area. All persons or...

  8. Travel and Tourism Industry: Program Options for City College of San Francisco.

    Science.gov (United States)

    City Coll. of San Francisco, CA.

    In an effort to determine the current occupational outlook and resulting implications for education and training, the City College of San Francisco (CCSF), in California, undertook a study of current trends in the travel and tourism industry. This report provides findings from the project, which involved consultation with local and national…

  9. Realizing a Progressive Pedagogy: A Comparative Case Study of Two Reggio Emilia Preschools in San Francisco

    Science.gov (United States)

    Abdelfattah, Marwa

    2015-01-01

    This study aims to uncover how a particular imported philosophy of early childhood education, Reggio Emilia, is implemented in the context of one public and one private preschool in San Francisco. The philosophy of Reggio Emilia is believed to be progressive and to be developmentally appropriate for children in early childhood. The study involved…

  10. Communications and Collaboration Keep San Francisco VA Medical Center Project on Track

    International Nuclear Information System (INIS)

    Federal Energy Management Program

    2001-01-01

    This case study about energy saving performance contacts (ESPCs) presents an overview of how the Veterans Affairs Medical Center in San Francisco established an ESPC contract and the benefits derived from it. The Federal Energy Management Program instituted these special contracts to help federal agencies finance energy-saving projects at their facilities

  11. CAREER TRAINING IN HOTEL AND RESTAURANT OPERATION...AT CITY COLLEGE OF SAN FRANCISCO.

    Science.gov (United States)

    BATMALE, LOUIS F.; MULLANY, GEORGE G.

    THE HOTEL AND RESTAURANT PROGRAM, ONE OF 35 SEMIPROFESSIONAL TRAINING PROGRAMS AT CITY COLLEGE OF SAN FRANCISCO, COMBINES GENERAL EDUCATION, RELATED BUSINESS INSTRUCTION, HOTEL AND RESTAURANT CLASSES, FOOD PREPARATION AND SERVICE TRAINING, AND WORK EXPERIENCE. THIS DESCRIPTION OF THE PROGRAM INCLUDES (1) PURPOSES AND OBJECTIVES, (2) CURRICULUM,…

  12. 78 FR 75249 - Safety Zone: Google's Night at Sea Fireworks Display, San Francisco Bay, Alameda, CA

    Science.gov (United States)

    2013-12-11

    ...-AA00 Safety Zone: Google's Night at Sea Fireworks Display, San Francisco Bay, Alameda, CA AGENCY: Coast... Google's Night at Sea Fireworks Displays on December 7, 2013 and December 14, 2013. These safety zones... Coast Guard to establish safety zones. Google will sponsor the Google's Night at Sea Fireworks Displays...

  13. 33 CFR 165.1182 - Safety/Security Zone: San Francisco Bay, San Pablo Bay, Carquinez Strait, and Suisun Bay, CA.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety/Security Zone: San... Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY... Areas Eleventh Coast Guard District § 165.1182 Safety/Security Zone: San Francisco Bay, San Pablo Bay...

  14. Distribution and demography of San Francisco gartersnakes (Thamnophis sirtalis tetrataenia) at Mindego Ranch, Russian Ridge Open Space Preserve, San Mateo County, California

    Science.gov (United States)

    Kim, Richard; Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L.

    2018-04-26

    San Francisco gartersnakes (Thamnophis sirtalis tetrataenia) are a subspecies of common gartersnakes endemic to the San Francisco Peninsula of northern California. Because of habitat loss and collection for the pet trade, San Francisco gartersnakes were listed as endangered under the precursor to the Federal Endangered Species Act. A population of San Francisco gartersnakes resides at Mindego Ranch, San Mateo County, which is part of the Russian Ridge Open Space Preserve owned and managed by the Midpeninsula Regional Open Space District (MROSD). Because the site contained non-native fishes and American bullfrogs (Lithobates catesbeianus), MROSD implemented management to eliminate or reduce the abundance of these non-native species in 2014. We monitored the population using capture-mark-recapture techniques to document changes in the population during and following management actions. Although drought confounded some aspects of inference about the effects of management, prey and San Francisco gartersnake populations generally increased following draining of Aquatic Feature 3. Continued management of the site to keep invasive aquatic predators from recolonizing or increasing in abundance, as well as vegetation management that promotes heterogeneous grassland/shrubland near wetlands, likely would benefit this population of San Francisco gartersnakes.

  15. 77 FR 43161 - Special Local Regulation; San Francisco Bay Navy Fleetweek Parade of Ships and Blue Angels...

    Science.gov (United States)

    2012-07-24

    .... 3. Privacy Act Anyone can search the electronic form of comments received into any of our dockets by... tactical coxswains from Sector San Francisco's boat stations, has led the Coast Guard to determine that a...

  16. Environmental Sensitivity Index (ESI) Atlas: San Francisco Bay - 1998, maps and geographic information systems data (NODC Accession 0036884)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set comprises the Environmental Sensitivity Index (ESI) maps for the shoreline of San Francisco Bay. ESI data characterize estuarine environments and...

  17. Environmental Sensitivity Index (ESI) Atlas: San Francisco Bay, California maps and geographic information systems data (NODC Accession 0013224)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set comprises the Environmental Sensitivity Index (ESI) maps for the shoreline of San Francisco Bay. ESI data characterize estuarine environments and...

  18. Metropolitan Transportation Commission, San Francisco Bay area : developing regional objectives and performance measures to improve system operations

    Science.gov (United States)

    2009-04-01

    The Metropolitan Transportation Commission (MTC) uses an objectives-driven, performance-based approach in its transportation planning for the San Francisco Bay Area. This approach focuses attention on transportation investments of highest priority. T...

  19. Uudised : Neeme Järvi San Franciscos. Tõnis Mägi Moskvas. TMKK Norras ja Ungaris / Priit Kuusk

    Index Scriptorium Estoniae

    Kuusk, Priit, 1938-

    2000-01-01

    N. Järvi juhatab San Francisco Ooperis Rimski-Korsakovi ooperit "Tsaari mõrsja", esietendus 11. sept. T. Mägi esines 1. sept. Eesti Suursaatkonnas Moskvas. TMKK Kammerkoori kontsertreisidest Norrasse ja Ungarisse

  20. Precarious City: Marginal Workers, The State, And Working-Class Activism In Post-Industrial San Francisco, 1964-1979

    OpenAIRE

    Martin, Laura Renata

    2014-01-01

    This project investigates the effects of San Francisco's transition from an industrial to a post-industrial economy on the city's social movements between 1964 and 1979. I re-contextualize the city's Black freedom, feminist, and gay and transgender liberation movements as struggles over the changing nature of urban working-class life and labor in the postwar period. I argue that as San Francisco was increasingly emptied of its white ethnic industrial work force, working-class life became more...

  1. Iron, Oil, and Emeryville: Resource Industrialization and Metropolitan Expansion in the San Francisco Bay Area, 1850-1900

    OpenAIRE

    Lunine, Seth

    2013-01-01

    Scholars have largely overlooked the formative role of industry in both California's economic development and the San Francisco Bay Area's metropolitan expansion during the late nineteenth century. Beginning in the early 1880s, leading firms in San Francisco's specialized industries, such as the iron and chemicals sectors, dispersed to the metropolitan periphery. This process of industrial suburbanization created an integrative metropolitan economy, as well as individual suburbs. In this di...

  2. Surveillance for previously unmonitored organic contaminants in the San Francisco Estuary.

    Science.gov (United States)

    Oros, Daniel R; Jarman, Walter M; Lowe, Theresa; David, Nicole; Lowe, Sarah; Davis, Jay A

    2003-09-01

    The San Francisco Estuary Regional Monitoring Program initiated surveillance monitoring to identify previously unmonitored synthetic organic contaminants in the San Francisco Estuary. Organic extracts of water samples were analyzed using gas chromatography-mass spectrometry in full scan mode. The major contaminant classes identified in the samples were fire retardants, pesticides, personal care product ingredients, and plasticizers. Evidence from the literature suggests that some of these contaminants can persist in the environment, induce toxicity, and accumulate in marine biota and in higher food chain consumers. The major sources of these contaminants into the marine environment are the discharge of municipal and industrial wastewater effluents, urban stormwater, and agricultural runoff. As a proactive effort, it is suggested that surveillance studies be used routinely in monitoring programs to identify and prevent potential problem contaminants from harming the marine environment.

  3. Earthquakes and faults in the San Francisco Bay area (1970-2003)

    Science.gov (United States)

    Sleeter, Benjamin M.; Calzia, James P.; Walter, Stephen R.; Wong, Florence L.; Saucedo, George J.

    2004-01-01

    The map depicts both active and inactive faults and earthquakes magnitude 1.5 to 7.0 in the greater San Francisco Bay area. Twenty-two earthquakes magnitude 5.0 and greater are indicated on the map and listed chronologically in an accompanying table. The data are compiled from records from 1970-2003. The bathymetry was generated from a digital version of NOAA maps and hydrogeographic data for San Francisco Bay. Elevation data are from the USGS National Elevation Database. Landsat satellite image is from seven Landsat 7 Enhanced Thematic Mapper Plus scenes. Fault data are reproduced with permission from the California Geological Survey. The earthquake data are from the Northern California Earthquake Catalog.

  4. Migration and HIV Risk Among Men Who Have Sex With Men, San Francisco, 2011.

    Science.gov (United States)

    Lama, T T; Sudhinaraset, M; McFarland, W; Raymond, H F

    2015-12-01

    In San Francisco, MSM account for nearly 90% of HIV infections. Studies have postulated increased risk for HIV faced by MSM who migrate, particularly to urban environments, yet empirical data are lacking. In this study we analyzed data from the National HIV Behavioral Surveillance System collected in 2011 to ascertain whether nativity (U.S. versus foreign born) was associated with HIV prevalence, risk behavior, and service use. Among 510 MSM enrolled, HIV prevalence was 23.0%. Multivariable analyses demonstrate that while nativity was not associated with increased risk for HIV infection, those who had lived in San Francisco for more than five years had higher HIV prevalence compared to those who had lived for less than a year even after adjusting for age, race, income, education, and location of birth.

  5. Parnaíba and San Francisco rivers: traveler's fascination and technicians' rationality

    Directory of Open Access Journals (Sweden)

    Gercinair Silvério Gandara

    2013-02-01

    Full Text Available Considering that the environmental variable opens up the prospect of countless historical approaches, I will give attention (having Parnaíba and San Francisco river as scenery to the travelers' accounts,the reports of technicians and engineers, to the political speeches and governmental decisionsundertaken in order to promote better navigability in both rivers. I will also highlight the studies and services aimed to the removal of obstacles the environment from the Parnaíba and San Franciscorivers in the second half the nineteenth century and first half of the twentieth century.

  6. Modified Mercalli intensities for some recent California earthquakes and historic San Francisco Bay Region earthquakes

    Science.gov (United States)

    Bakun, William H.

    1998-01-01

    Modified Mercalli Intensity (MMI) data for recent California earthquakes were used by Bakun and Wentworth (1997) to develop a strategy for bounding the location and moment magnitude M of earthquakes from MMI observations only. Bakun (Bull. Seismol. Soc. Amer., submitted) used the Bakun and Wentworth (1997) strategy to analyze 19th century and early 20th century San Francisco Bay Region earthquakes. The MMI data and site corrections used in these studies are listed in this Open-file Report. 

  7. Religiosidad e identidad en San Francisco de Campeche. Siglos XVI y XVII

    OpenAIRE

    Rocher Salas, Adriana Delfina

    2006-01-01

    This study examines the problems concomitant to the development of a common identity among the Spanish settlers of San Francisco de Campeche during the Colonial period, with focus on the role played by religious elements in the shaping of this identity – in particular, the cult to the saints. An analysis of factors such as the characteristics of the saints in the neighborhood and local associations; processes of cult adoption, adaptation or dismissal; as well as the participation of the ...

  8. Global Health Diplomacy, "San Francisco Values," and HIV/AIDS: From the Local to the Global.

    Science.gov (United States)

    Kevany, Sebastian

    2015-01-01

    San Francisco has a distinguished history as a cosmopolitan, progressive, and international city, including extensive associations with global health. These circumstances have contributed to new, interdisciplinary scholarship in the field of global health diplomacy (GHD). In the present review, we describe the evolution and history of GHD at the practical and theoretical levels within the San Francisco medical community, trace related associations between the local and the global, and propose a range of potential opportunities for further development of this dynamic field. We provide a historical overview of the development of the "San Francisco Model" of collaborative, community-owned HIV/AIDS treatment and care programs as pioneered under the "Ward 86" paradigm of the 1980s. We traced the expansion and evolution of this model to the national level under the Ryan White Care Act, and internationally via the President's Emergency Plan for AIDS Relief. In parallel, we describe the evolution of global health diplomacy practices, from the local to the global, including the integration of GHD principles into intervention design to ensure social, political, and cultural acceptability and sensitivity. Global health programs, as informed by lessons learned from the San Francisco Model, are increasingly aligned with diplomatic principles and practices. This awareness has aided implementation, allowed policymakers to pursue related and progressive social and humanitarian issues in conjunction with medical responses, and elevated global health to the realm of "high politics." In the 21st century, the integration between diplomatic, medical, and global health practices will continue under "smart global health" and GHD paradigms. These approaches will enhance intervention cost-effectiveness by addressing and optimizing, in tandem with each other, a wide range of (health and non-health) foreign policy, diplomatic, security, and economic priorities in a synergistic manner

  9. Liminalidad social y negociación cultural: inmigrantes yucatecos en San Francisco, California

    Directory of Open Access Journals (Sweden)

    Inés Cornejo-Portugal

    2012-01-01

    Full Text Available Mediante los conceptos de liminalidad social y negociación cultural analizamos tres estudios de caso de yucatecos migrantes en San Francisco, California. Los migrantes estudiados dan cuenta de las diversas formas como utilizan los recursos sociales a los cuales tienen acceso (familiares, de creencia, de amistad y vecinales y que les permiten encontrar un equilibrio emocional relativo, frente a la tensión cultural de la sociedad destino.

  10. After the I-Hotel : Material, Cultural, and Affective Geographies of Filipino San Francisco

    OpenAIRE

    Tagle, Thea Quiray

    2015-01-01

    This dissertation traces the cultural and economic trajectories of Filipino migration to, settlement in, and displacement from the San Francisco Bay Area from the 1960s through the present moment as represented in the work of local poets, visual artists, and performers. After the I-Hotel argues that the shifting representations of urban and suburban space over this time period not only reveal the structural forces behind the displacement of old and new Filipino migrants in the Bay Area, but a...

  11. Groundwater quality in the North San Francisco Bay shallow aquifer, California

    Science.gov (United States)

    Bennett, George L.; Fram, Miranda S.

    2018-02-23

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The North San Francisco Bay Shallow Aquifer constitutes one of the study units being evaluated.

  12. Paleomagnetic investigation of late Quaternary sediments of south San Francisco Bay, California

    Science.gov (United States)

    Hillhouse, John W.

    1977-01-01

    Paleomagnetic inclinations of the Late Quaternary sediments of South San Francisco Bay were determined from bore hole samples collected near Dumbarton Bridge. The sediments consist of estuarine muds and nonmarine sand deposits, floored by bedrock of the Mesozoic Franciscan Formation. - Beneath Dumbarton Bridge the entire sedimentary fill is normally polarized; therefore, the fill postdates the Brunhes-Matayama polarity reversal (700,000 y. B.P.). Magnetic time lines such as the Mono Lake excursion (24,000 y. B.P.) and the reversed Blake event (110,000 y B.P.) were not found in this bore hole. In addition to Holocene and modern deposits of San Francisco Bay, an older estuarine unit occurs in the stratigraphic section. The older unit was deposited during a period of high sea level, tentatively correlated with the Sangamon interglacial period. Because evidence of the Blake event is not present in the older estuarine unit, the proposed age of this unit could not be confirmed. Although the Holocene estuarine deposits of South San Francisco Bay carry stable remanent magnetization, a reliable record of geomagnetic secular variation could not be recovered because the water-saturated sdiment was deformed by drilling.

  13. Modeling Trace Element Concentrations in the San Francisco Bay Estuary from Remote Measurement of Suspended Solids

    Science.gov (United States)

    Press, J.; Broughton, J.; Kudela, R. M.

    2014-12-01

    Suspended and dissolved trace elements are key determinants of water quality in estuarine and coastal waters. High concentrations of trace element pollutants in the San Francisco Bay estuary necessitate consistent and thorough monitoring to mitigate adverse effects on biological systems and the contamination of water and food resources. Although existing monitoring programs collect annual in situ samples from fixed locations, models proposed by Benoit, Kudela, & Flegal (2010) enable calculation of the water column total concentration (WCT) and the water column dissolved concentration (WCD) of 14 trace elements in the San Francisco Bay from a more frequently sampled metric—suspended solids concentration (SSC). This study tests the application of these models with SSC calculated from remote sensing data, with the aim of validating a tool for continuous synoptic monitoring of trace elements in the San Francisco Bay. Using HICO imagery, semi-analytical and empirical SSC algorithms were tested against a USGS dataset. A single-band method with statistically significant linear fit (p Arsenic, Iron, and Lead in the southern region of the Bay were found to exceed EPA water quality criteria for human health and aquatic life. The results of this study demonstrate the potential of monitoring programs using remote observation of trace element concentrations, and provide the foundation for investigation of pollutant sources and pathways over time.

  14. UCSF partnership to enrich science teaching for sixth graders in San Francisco's schools.

    Science.gov (United States)

    Doyle, H J

    1999-04-01

    Increasing the diversity of students entering the health professions is a challenging goal for medical schools. One approach to this goal is to share the enthusiasm and energy of medical students with younger students, who may pursue medical education in the future. The MedTeach program, established in 1989 and coordinated by the Science & Health Education Partnership of the University of California, San Francisco (UCSF), does so by partnering volunteer medical students from UCSF with sixth-grade classes studying the human body. In 1997-98, around 350 sixth-graders in the San Francisco Schools benefitted from the program. Each team of medical student's visits its class ten to 12 times a year to present engaging, hands-on lessons on body systems and health. The medical students are also role models for the middle-school students. In addition, the diverse student population of San Francisco public schools provides a rich environment for the medical students to improve their communication and teaching skills.

  15. Sediment transport of streams tributary to San Francisco, San Pablo, and Suisun Bays, California, 1909-66

    Science.gov (United States)

    Porterfield, George

    1980-01-01

    A review of historical sedimentation data is presented, results of sediment-data collection for water years 1957-59 are summarized, and long-term sediment-discharge estimates from a preliminary report are updated. Comparison of results based on 3 years of data to those for the 10 water years, 1957-66, provides an indication of the adequacy of the data obtained during the short period to define the long-term relation between sediment transport and streamflow. During 1909-66, sediment was transported to the entire San Francisco Bay system at an average rate of 8.6 million cubic yards per year. The Sacramento and San Joaquin River basins provided about 83% of the sediment inflow to the system annually during 1957-66 and 86% during 1909-66. About 98% of this inflow was measured or estimated at sediment measuring sites. Measured sediment inflow directly to the bays comprised only about 40% of the total discharged by basins directly tributary to the bays. About 90% of the total sediment discharge to the delta and the bays in the San Francisco Bay system thus was determined on the basis of systematic measurements. (USGS)

  16. Anthropogenic influence on recent bathymetric change in west-central San Francisco Bay

    Science.gov (United States)

    Barnard, Patrick L.; Kvitek, Rikk G.

    2010-01-01

    Two multibeam sonar surveys of west-central San Francisco Bay, California, were conducted in 1997 and 2008. Bathymetric change analysis between the two surveys indicates a loss of 14.1 million cubic meters (-3.1 cm/yr-1) of sediment during this time period, representing an approximately three-fold acceleration of the rate that was observed from prior depth change analysis from 1947 to 1979 for all of Central Bay, using more spatially coarse National Ocean Service (NOS) soundings. The portions of the overlapping survey areas between 1997 and 2008 designated as aggregate mining lease sites lost sediment at five times the rate of the remainder of west-central San Francisco Bay. Despite covering only 28% of the analysis area, volume change within leasing areas accounted for 9.2 million cubic meters of sediment loss, while the rest of the area lost 4.9 million cubic meters of sediment. The uncertainty of this recent analysis is more tightly constrained due to more stringent controls on vertical and horizontal position via tightly coupled, inertially aided differential Global Positioning Systems (GPS) solutions for survey vessel trajectory that virtually eliminate inaccuracies from traditional tide modeling and vessel motion artifacts. Further, quantification of systematic depth measurement error can now be calculated through comparison of static surfaces (e.g., bedrock) between surveys using seafloor habitat maps based on acoustic backscatter measurements and ground-truthing with grab samples and underwater video. Sediment loss in the entire San Francisco Bay Coastal System during the last half-century,as estimated from a series of bathymetric change studies, is 240 million cubic meters, and most of this is believed to be coarse sediment (i.e., sand and gravel) from Central Bay and the San Francisco Bar, which is likely to limit the sand supply to adjacent, open-coast beaches. This hypothesis is supported by a calibrated numerical model in a related study that indicates

  17. Waterbird nest monitoring program in San Francisco Bay (2005-10)

    Science.gov (United States)

    Ackerman, Joshua T.; Herzog, Mark P.

    2012-01-01

    Historically, Forster’s Terns (Sterna forsteri), American Avocets (Recurvirostra americana), and Black-necked Stilts (Himantopus mexicanus) were uncommon residents of San Francisco Bay, California (Grinnell and others, 1918; Grinnell and Wythe, 1927; Sibley, 1952). Presently, however, avocets and stilts are the two most abundant breeding shorebirds in San Francisco Bay (Stenzel and others, 2002; Rintoul and others, 2003). More than 4,000 avocets and 1,000 stilts, roughly 20 percent of their San Francisco Bay wintering populations, breed within the estuary, making San Francisco Bay the largest breeding area for these species on the Pacific Coast (Stenzel and others, 2002; Rintoul and others, 2003). Forster’s Terns were first observed breeding in the San Francisco Bay in 1948 (110 nests); they had increased to over 4000 individuals by the 1980s (Sibley, 1952; Gill, 1977; Harvey and others, 1992; Carter and others, 1990) and were estimated at 2000–3000 for 1998–2002; (Strong and others, 2004).It is hypothesized that the relatively large size of the current waterbird breeding populations is a result of the creation of artificial salt evaporation ponds from the 1930s through the 1950s (Gill, 1977; Goals Project, 1999). Until recently, these salt ponds and associated islands used by waterbirds for nesting have been managed relatively similarly and have supported large breeding waterbird populations. Recently, the South Bay Salt Pond Restoration Project has implemented plans to convert 50–90 percent of the 15,000 acres of salt ponds in the South San Francisco Bay back to tidal marsh habitat. Therefore, there is concern that the Restoration Project, while benefiting other native species, could negatively influence local breeding populations of waterbirds that are reliant on salt pond habitats for both breeding and foraging. A primary goal of the South Bay Salt Pond Restoration Project is to maintain current breeding waterbird populations (South Bay Salt Pond Long

  18. A Tidally Averaged Sediment-Transport Model for San Francisco Bay, California

    Science.gov (United States)

    Lionberger, Megan A.; Schoellhamer, David H.

    2009-01-01

    A tidally averaged sediment-transport model of San Francisco Bay was incorporated into a tidally averaged salinity box model previously developed and calibrated using salinity, a conservative tracer (Uncles and Peterson, 1995; Knowles, 1996). The Bay is represented in the model by 50 segments composed of two layers: one representing the channel (>5-meter depth) and the other the shallows (0- to 5-meter depth). Calculations are made using a daily time step and simulations can be made on the decadal time scale. The sediment-transport model includes an erosion-deposition algorithm, a bed-sediment algorithm, and sediment boundary conditions. Erosion and deposition of bed sediments are calculated explicitly, and suspended sediment is transported by implicitly solving the advection-dispersion equation. The bed-sediment model simulates the increase in bed strength with depth, owing to consolidation of fine sediments that make up San Francisco Bay mud. The model is calibrated to either net sedimentation calculated from bathymetric-change data or measured suspended-sediment concentration. Specified boundary conditions are the tributary fluxes of suspended sediment and suspended-sediment concentration in the Pacific Ocean. Results of model calibration and validation show that the model simulates the trends in suspended-sediment concentration associated with tidal fluctuations, residual velocity, and wind stress well, although the spring neap tidal suspended-sediment concentration variability was consistently underestimated. Model validation also showed poor simulation of seasonal sediment pulses from the Sacramento-San Joaquin River Delta at Point San Pablo because the pulses enter the Bay over only a few days and the fate of the pulses is determined by intra-tidal deposition and resuspension that are not included in this tidally averaged model. The model was calibrated to net-basin sedimentation to calculate budgets of sediment and sediment-associated contaminants. While

  19. Heavy mineral analysis for assessing the provenance of sandy sediment in the San Francisco Bay Coastal System

    Science.gov (United States)

    Wong, Florence L.; Woodrow, Donald L.; McGann, Mary

    2013-01-01

    Heavy or high-specific gravity minerals make up a small but diagnostic component of sediment that is well suited for determining the provenance and distribution of sediment transported through estuarine and coastal systems worldwide. By this means, we see that surficial sand-sized sediment in the San Francisco Bay Coastal System comes primarily from the Sierra Nevada and associated terranes by way of the Sacramento and San Joaquin Rivers and is transported with little dilution through the San Francisco Bay and out the Golden Gate. Heavy minerals document a slight change from the strictly Sierran-Sacramento mineralogy at the confluence of the two rivers to a composition that includes minor amounts of chert and other Franciscan Complex components west of Carquinez Strait. Between Carquinez Strait and the San Francisco Bar, Sierran sediment is intermingled with Franciscan-modified Sierran sediment. The latter continues out the Gate and turns southward towards beaches of the San Francisco Peninsula. The Sierran sediment also fans out from the San Francisco Bar to merge with a Sierran province on the shelf in the Gulf of the Farallones. Beach-sand sized sediment from the Russian River is transported southward to Point Reyes where it spreads out to define a Franciscan sediment province on the shelf, but does not continue southward to contribute to the sediment in the Golden Gate area.

  20. Stable lead isotopic analyses of historic and contemporary lead contamination of San Francisco Bay estuary

    Science.gov (United States)

    Ritson, P.I.; Bouse, R.M.; Flegal, A.R.; Luoma, S.N.

    1999-01-01

    Variations in stable lead isotopic composition (240Pb, 206Pb, 207Pb, 208Pb) in three sediment cores from the San Francisco Bay estuary document temporal changes in sources of lead during the past two centuries. Sediment, with lead from natural geologic sources, and relatively homogeneous lead isotopic compositions are overlain by sediments whose isotopic compositions indicate change in the sources of lead associated with anthropogenic modification of the estuary. The first perturbations of lead isotopic composition in the cores occur in the late 1800s concordant with the beginning of industrialization around the estuary. Large isotopic shifts, toward lower 206Pb/207Pb, occur after the turn of the century in both Richardson and San Pablo Bays. A similar relationship among lead isotopic compositions and lead concentrations in both Bays suggest contamination from the same source (a lead smelter). The uppermost sediments (post 1980) of all cores also have a relatively homogenous lead isotopic composition distinct from pre-anthropogenic and recent aerosol signatures. Lead isotopic compositions of leachates from fourteen surface sediments and five marsh samples from the estuary were also analyzed. These analyses suggest that the lead isotopic signature identified in the upper horizons of the cores is spatially homogeneous among recently deposited sediments throughout the estuary. Current aerosol lead isotopic compositions [Smith, D.R., Niemeyer, S., Flegal, A.R., 1992. Lead sources to California sea otters: industrial inputs circumvent natural lead biodepletion mechanisms. Environmental Research 57, 163-175] are distinct from the isotopic compositions of the surface sediments, suggesting that the major source of lead is cycling of historically contaminated sediments back through the water column. Both the upper core sediments and surface sediments apparently derive their lead predominantly from sources internal to the estuary. These results support the idea that

  1. Description of gravity cores from San Pablo Bay and Carquinez Strait, San Francisco Bay, California

    Science.gov (United States)

    Woodrow, Donald L.; John L. Chin,; Wong, Florence L.; Fregoso, Theresa A.; Jaffe, Bruce E.

    2017-06-27

    Seventy-two gravity cores were collected by the U.S. Geological Survey in 1990, 1991, and 2000 from San Pablo Bay and Carquinez Strait, California. The gravity cores collected within San Pablo Bay contain bioturbated laminated silts and sandy clays, whole and broken bivalve shells (mostly mussels), fossil tube structures, and fine-grained plant or wood fragments. Gravity cores from the channel wall of Carquinez Strait east of San Pablo Bay consist of sand and clay layers, whole and broken bivalve shells (less than in San Pablo Bay), trace fossil tubes, and minute fragments of plant material.

  2. Sediment transport in the San Francisco Bay Coastal System: An overview

    Science.gov (United States)

    Barnard, Patrick L.; Schoellhamer, David H.; Jaffe, Bruce E.; Lester J. McKee,

    2013-01-01

    The papers in this special issue feature state-of-the-art approaches to understanding the physical processes related to sediment transport and geomorphology of complex coastal-estuarine systems. Here we focus on the San Francisco Bay Coastal System, extending from the lower San Joaquin-Sacramento Delta, through the Bay, and along the adjacent outer Pacific Coast. San Francisco Bay is an urbanized estuary that is impacted by numerous anthropogenic activities common to many large estuaries, including a mining legacy, channel dredging, aggregate mining, reservoirs, freshwater diversion, watershed modifications, urban run-off, ship traffic, exotic species introductions, land reclamation, and wetland restoration. The Golden Gate strait is the sole inlet connecting the Bay to the Pacific Ocean, and serves as the conduit for a tidal flow of ~ 8 x 109 m3/day, in addition to the transport of mud, sand, biogenic material, nutrients, and pollutants. Despite this physical, biological and chemical connection, resource management and prior research have often treated the Delta, Bay and adjacent ocean as separate entities, compartmentalized by artificial geographic or political boundaries. The body of work herein presents a comprehensive analysis of system-wide behavior, extending a rich heritage of sediment transport research that dates back to the groundbreaking hydraulic mining-impact research of G.K. Gilbert in the early 20th century.

  3. Spatial and temporal trends of contaminants in eggs of wading birds from San Francisco Bay, California

    Science.gov (United States)

    Hothem, R.L.; Roster, D.L.; King, K.A.; Keldsen, T.J.; Marois, Katherine C.; Wainwright, S.E.

    1995-01-01

    Between 1989 and 1991, reproduction by black-crowned night-herons (Nycticorax nycticorax) and snowy egrets (Egretta thula) was studied at sites in San Francisco Bay. Eggs were collected from these and other bay sites and from South Wilbur Flood Area, a reference site in California's San Joaquin Valley. Eggs were analyzed for inorganic trace elements, organochlorine pesticides, and polychlorinated biphenyls (PCBs). Results were compared among sites and years and with results of previous studies. There was some evidence of impaired reproduction, but concentrations of contaminants were generally lower than threshold levels for such effects. Egg hatchability was generally good, with predation being the factor that most limited reproductive success. Mean PCB concentrations were generally higher in eggs from the south end of San Francisco Bay than from the north, but the only temporal change, an increase, was observed at Alcatraz Island. There were spatial differences for p,p'-DDE in night-heron eggs in 1990, but the highest mean concentration of DDE was in night-heron eggs from South Wilbur in 1991. Temporal declines in maximum concentrations of DDE in eggs were observed in the bay, but means did not change significantly over time, At Bair Island in the southern end of the bay, mean concentrations of mercury decreased while selenium increased in night-heron eggs over time, but there were no clear bay-wide spatial or temporal trends for either element.

  4. Quaternary geology of Alameda County, and parts of Contra Costa, Santa Clara, San Mateo, San Francisco, Stanislaus, and San Joaquin counties, California: a digital database

    Science.gov (United States)

    Helley, E.J.; Graymer, R.W.

    1997-01-01

    Alameda County is located at the northern end of the Diablo Range of Central California. It is bounded on the north by the south flank of Mount Diablo, one of the highest peaks in the Bay Area, reaching an elevation of 1173 meters (3,849 ft). San Francisco Bay forms the western boundary, the San Joaquin Valley borders it on the east and an arbitrary line from the Bay into the Diablo Range forms the southern boundary. Alameda is one of the nine Bay Area counties tributary to San Francisco Bay. Most of the country is mountainous with steep rugged topography. Alameda County is covered by twenty-eight 7.5' topographic Quadrangles which are shown on the index map. The Quaternary deposits in Alameda County comprise three distinct depositional environments. One, forming a transgressive sequence of alluvial fan and fan-delta facies, is mapped in the western one-third of the county. The second, forming only alluvial fan facies, is mapped in the Livermore Valley and San Joaquin Valley in the eastern part of the county. The third, forming a combination of Eolian dune and estuarine facies, is restricted to the Alameda Island area in the northwestern corner of the county.

  5. When it happens again: impact of future San Francisco Bay area earthquakes

    Science.gov (United States)

    Zoback, M.; Boatwright, J.; Kornfield, L.; Scawthorn, C.; Rojahn, C.

    2005-12-01

    San Francisco Bay area earthquakes, like major floods and hurricanes, have the potential for massive damage to dense urban population centers concentrated in vulnerable zones-along active faults, in coastal regions, and along major river arteries. The recent destruction of Hurricane Katrina does have precedent in the destruction following the 1906 "San Francisco" earthquake and fire in which more than 3000 people were killed and 225,000 were left homeless in San Francisco alone, a city of 400,000 at the time. Analysis of a comprehensive set of damage reports from the magnitude (M) 7.9 1906 earthquake indicates a region of ~ 18,000 km2 was subjected to shaking of Modified Mercalli Intensity of VIII or more - motions capable of damaging even modern, well-built structures; more than 60,000 km2 was subjected to shaking of Intensity VII or greater - the threshold for damage to masonry and poorly designed structures. By comparison, Katrina's hurricane force winds and intense rainfall impacted an area of ~100,000 km2 on the Gulf Coast. Thus, the anticipated effects of a future major Bay Area quake to lives, property, and infrastructure are comparable in scale to Katrina. Secondary hazards (levee failure and flooding in the case of Katrina and fire following the 1906 earthquake) greatly compounded the devastation in both disasters. A recent USGS-led study concluded there is a 62% chance of one or more damaging (M6.7 or greater) earthquakes striking the greater San Francisco Bay area over the next 30 years. The USGS prepared HAZUS loss estimates for the 10 most likely forecast earthquakes which range in size from a M6.7 event on a blind thrust to the largest anticipated event, a M7.9 repeat of the 1906 earthquake. The largest economic loss is expected for a repeat of the 1906 quake. Losses in the Bay region for this event are nearly double those predicted for a M6.9 rupture of the entire Hayward Fault in the East Bay. However, because of high density of population along the

  6. Space use and habitat selection of migrant and resident American Avocets in San Francisco Bay

    Science.gov (United States)

    Demers, Scott A.; Takekawa, John Y.; Ackerman, Joshua T.; Warnock, N.; Athearn, N.D.

    2010-01-01

    San Francisco Bay is a wintering area for shorebirds, including American Avocets (Recurvirostra americana). Recently, a new resident population of avocets has emerged, presumably because of the development of tidal marshes into salt-evaporation ponds. In habitat restoration now underway, as many as 90% of salt ponds will be restored to tidal marsh. However, it is unknown if wintering and resident avocets coexist and if their requirements for space and habitat differ, necessitating different management for their populations to be maintained during restoration. We captured and radio-marked wintering avocets at a salt pond and a tidal flat to determine their population status (migrant or resident) and examine their space use and habitat selection. Of the radio-marked avocets, 79% were migrants and 21% were residents. At the salt pond, residents' fidelity to their location of capture was higher, and residents moved less than did migrants from the same site. Conversely, on the tidal flat, fidelity of residents to their site of capture was lower, and residents' home ranges were larger than those of migrants from the same site. Habitat selection of migrants and residents differed little; however, capture site influenced habitat selection far more than the birds' status as migrants or residents. Our study suggests that individual avocets have high site fidelity while wintering in San Francisco Bay, although the avocet as a species is plastic in its space use and habitat selection. This plasticity may allow wintering migrant and resident avocets to adapt to habitat change in San Francisco Bay. ?? The Cooper Ornithological Society 2010.

  7. Knowledge, Indications and Willingness to Take Pre-Exposure Prophylaxis among Transwomen in San Francisco, 2013.

    Directory of Open Access Journals (Sweden)

    Erin C Wilson

    Full Text Available Safe and effective HIV prevention strategies are needed for transwomen. Transwomen in the US have a 34 times greater odds of being infected with HIV than all adults age 15-49, and in San Francisco, California 42.4% of transwomen are estimated to be infected with HIV. Pre-exposure prophylaxis (PrEP is the first biomedical intervention with promise for reducing HIV acquisition in transwomen. However, little is known about whether transwomen know about PrEP, are taking PrEP and would be good candidates for PrEP based on their risk profile and behaviors. A population-based dataset was analyzed to determine how many transwomen in San Francisco knew about PrEP by the end of 2013 - more than a year after iPrex results demonstrated efficacy of PrEP in preventing HIV. We found that of 233 transwomen, only 13.7% had heard of PrEP. Transwomen who were living with HIV compared to those who were HIV-negative, and those who recently injected drugs compared to non-injection drug users were more likely to have heard of PrEP. Based on CDC guidelines for PrEP among MSM and IDU, 45 (30.2% transwomen of the 149 HIV-negative transwomen in the sample were candidates for PrEP. This estimate based on CDC criteria is arguably low. Given that almost half of transwomen in San Francisco are living with HIV, this findings points to a need for further consideration of PrEP criteria that are specific and tailored to the risks for HIV faced by transwomen that are different from MSM and injection drug users. Research to scale up access and test the effectiveness of PrEP for transwomen is also urgently needed.

  8. Modeling the Joint Labor-Commute Engagement Decisions of San Francisco Bay Area Residents

    OpenAIRE

    Ory, David T.; Mokhtarian, Patricia L.

    2005-01-01

    Using socio-demographic, personality, and attitudinal data from 1,680 residents of the San Francisco Bay Area, we develop and estimate binary, multinomial, and nested logit models of the choice to work or not, whether or not to work at home, and whether to commute all of the time or some of the time (either by only working part time, or by working a compressed work week, or by telecommuting some of the time). To our knowledge, these are the first models of all these choices simultaneously. Th...

  9. Long path optical extinction and meteorology in the San Francisco bay area

    Energy Technology Data Exchange (ETDEWEB)

    Porch, W M; Galloway, T R; Green, T J; Ellsaesser, H W

    1981-01-01

    Comparison of night-time long path extinction (25 km) across San Francisco Bay and local meteorological measurements at Oakland Airport revealed a dominant role of boundary layer mixing on visibility. Inversion depth and inversion depth multiplied by wind speed were both strongly inversely correlated with night-time atmospheric extinction. Oakland Airport wind speed and humidity showed little correlation with the extinction measurements. Stellar extinction was also found to be sensitive to mixing depth. This is important as visibility and turbidity trend studies rarely include mixing depth measurements. These results indicate the importance of developing instruments to use the same light source for remote sensing of atmospheric constituents, wind and humidity.

  10. Earthquake outlook for the San Francisco Bay region 2014–2043

    Science.gov (United States)

    Aagaard, Brad T.; Blair, James Luke; Boatwright, John; Garcia, Susan H.; Harris, Ruth A.; Michael, Andrew J.; Schwartz, David P.; DiLeo, Jeanne S.; Jacques, Kate; Donlin, Carolyn

    2016-06-13

    Using information from recent earthquakes, improved mapping of active faults, and a new model for estimating earthquake probabilities, the 2014 Working Group on California Earthquake Probabilities updated the 30-year earthquake forecast for California. They concluded that there is a 72 percent probability (or likelihood) of at least one earthquake of magnitude 6.7 or greater striking somewhere in the San Francisco Bay region before 2043. Earthquakes this large are capable of causing widespread damage; therefore, communities in the region should take simple steps to help reduce injuries, damage, and disruption, as well as accelerate recovery from these earthquakes.

  11. SF-ROCKS: Reaching Out to Communities and Kids With Science in San Francisco

    Science.gov (United States)

    White, L. D.; Grove, K.; La Force, M. J.; Pestrong, R.; Dempsey, D. P.; Garcia, O.; Garfield, N.

    2002-12-01

    The SF-ROCKS program at San Francisco State University (SFSU), funded by a grant from the NSF-OEDG program, aims to increase the number of traditionally underrepresented students who enter college as geoscience majors through a multi-faceted collaborative watershed research project that provides teacher training, student education, and several tiers of mentoring relationships. In partnership with the San Francisco Unified School District and the City College of San Francisco (CCSF), SFSU Geosciences Department faculty guide urban high school students and their teachers in field-based research projects in the Islais, Yosemite, and Mission creek watersheds in southeastern San Francisco. SFSU and CCSF students assist teachers in the classroom and help to mentor their students. The collaborative program has a research base at SFSU and during the next several years will involve five high schools in communities that have highly diverse populations and ongoing environmental problems. Our goal with each high school is to focus earth and environmental science teachers on the geologic setting around their school, and to provide teachers and their students with relevant resources via teacher workshops, frequent interactions with college faculty and students, and an interactive web site and GIS database. During the summer of 2002, project scientists worked with 9th grade Integrated/Environmental Science teachers at Phillip and Sala Burton High School on a multi-layered, hands-on mapping and sampling partnership designed to identify and monitor environmental hazards and watershed characteristics in the Yosemite Creek watershed. The watershed - within which Burton High School is located - provides an interdisciplinary focus for collecting and analyzing rocks, soils, water chemistry and rainfall characteristics. SFSU faculty incorporated concepts and data from the project into ten watershed-theme lesson plans that are now part of the year-long Integrated Science curriculum at the

  12. Chlorinated hydrocarbon pesticides and polychlorinated biphenyls in sediment cores from San Francisco Bay

    Science.gov (United States)

    Venkatesan, M.I.; De Leon, R. P.; VanGeen, A.; Luoma, S.N.

    1999-01-01

    Sediment cores of known chronology from Richardson and San Pablo Bays in San Francisco Bay, CA, were analyzed for a suite of chlorinated hydrocarbon pesticides and polychlorinated biphenyls to reconstruct a historic record of inputs. Total DDTs (DDT = 2,4'- and 4,4'-dichlorodiphenyltrichloroethane and the metabolites, 2,4'- and 4,4'-DDE, -DDD) range in concentration from 4-21 ng/g and constitute a major fraction (> 84%) of the total pesticides in the top 70 cm of Richardson Bay sediment. A subsurface maximum corresponds to a peak deposition date of 1969-1974. The first measurable DDT levels are found in sediment deposited in the late 1930's. The higher DDT inventory in the San Pablo relative to the Richardson Bay core probably reflects the greater proximity of San Pablo Bay to agricultural activities in the watershed of the Sacramento and San Joaquin rivers. Total polychlorinated biphenyls (PCBs) occur at comparable levels in the two Bays (inventories in San Pablo Bay are about a factor of four higher in the last four decades than in Richardson Bay, suggesting a distribution of inputs not as strongly weighed towards the upper reaches of the estuary as DDTs. The shallower subsurface maximum in PCBs compared to DDT in the San Pablo Bay core is consistent with the imposition of drastic source control measures four these constituents in 1970 and 1977 respectively. The observed decline in DDT and PCB levels towards the surface of both cores is consistent with a dramatic drop in the input of these pollutants once the effect of sediment resuspension and mixing is taken into account.

  13. An Introduction to the San Francisco Estuary Tidal Wetlands Restoration Series

    Directory of Open Access Journals (Sweden)

    Larry R. Brown

    2003-10-01

    Full Text Available Restoration of tidal wetlands may provide an important tool for improving ecological health and water management for beneficial uses of the San Francisco Estuary (hereafter “Estuary”. Given the large losses of tidal wetlands from San Francisco Bay and the Sacramento-San Joaquin Delta in the last 150 years, it seems logical to assume that restoring tidal wetlands will have benefits for a variety of aquatic and terrestrial native species that have declined during the same time period. However, many other changes have also occurred in the Estuary concurrent with the declines of native species. Other factors that might be important in species declines include the effects of construction of upstream dams, large and small water diversions within the Sacramento-San Joaquin Delta, agricultural pesticides, trace elements from industrial and agricultural activities, and invasions of alien species. Discussions among researchers, managers, and stakeholders have identified a number of uncertainties regarding the potential benefits of tidal wetland restoration. The articles of the Tidal Wetlands Restoration Series address four major issues of concern. Stated as questions, these are: 1. Will tidal wetland restoration enhance populations of native fishes? 2. Will wetland restoration increase rates of methylation of mercury? 3. Will primary production and other ecological processes in restored tidal wetlands result in net export of organic carbon to adjacent habitats, resulting in enhancement of the food web? Will the carbon produced contribute to the formation of disinfection byproducts when disinfected for use as drinking water? 4. Will restored tidal wetlands provide long-term ecosystem benefits that can be sustained in response to ongoing physical processes, including sedimentation and hydrodynamics? Reducing the uncertainty surrounding these issues is of critical importance because tidal wetland restoration is assumed to be a critical tool for

  14. Handbook of Techniques and Guides for the Study of the San Francisco Bay-Delta-Estuary Complex, Part 2. Key to the Phytoplankton Phyla and Genera.

    Science.gov (United States)

    Helrich, Jane

    Project MER (Marine Ecology Research) is aimed at improving environmental education in the San Francisco Bay Area schools. This document is the second of a series of guides designed to help students and teachers gather data concerning the San Francisco Bay-Delta-Estuary Complex and to organize these data to make a contribution to the literature of…

  15. Deep Borehole Instrumentation Along San Francisco Bay Bridges: 1996 - 2003 and Strong Ground Motion Systhesis Along the San Francisco/Oakland Bay Bridge

    Energy Technology Data Exchange (ETDEWEB)

    Hutchings, L; Foxall, W; Kasameyer, P; larsen, S; Hayek, C; Tyler-Turpin, C; Aquilino, J; Long, L

    2005-04-22

    As a result of collaboration between the Berkeley Seismographic Station, Lawrence Livermore National Laboratory, and Caltrans, instrument packages have been placed in bedrock in six boreholes and two surface sites along the San Francisco/Oakland Bay Bridge. Since 1996 over 200 local earthquakes have been recorded. Prior to this study few seismic recording instruments existed in bed-rock in San Francisco Bay. We utilized the data to perform analysis of ground motion variability, wave passage, site response, and up-and down-hole wave propagation along the Bay Bridge. We also synthesized strong ground motion at nine locations along the Bay Bridge. Key to these studies is LLNL's effort to exploit the information available in weak ground motions (generally from earthquakes < M=4.0) to enhance predictions of seismic hazards. We found that Yerba Island has no apparent site response at the surface relative to a borehole site. The horizontal to vertical spectral ratio method best revealed no site response, while the complex signal spectral ratio method had the lowest variance for spectral ratios and best predicted surface recordings when the borehole recording was used as input. Both methods identified resonances at about the same frequencies. Regional attenuation results in a significant loss of high frequencies in both surface and borehole recordings. Records are band limited at near 3 Hz. Therefore a traditional rock outcrop site response, flat to high frequency in displacement, is not available. We applied a methodology to predict and synthesize strong ground motion along the San Francisco/Oakland Bay Bridge from a M=7.25 earthquake along the Hayward fault, about12 km distant. We synthesized for three-components and broad-band (0.0-25.0 Hz) ground motion accelerations, velocities, and displacements. We examined two different possible rupture scenarios, a ''mean'' and ''one standard deviation'' model. We combined the high

  16. Suspended sediment and sediment-associated contaminants in San Francisco Bay

    Science.gov (United States)

    Schoellhamer, D.H.; Mumley, T.E.; Leatherbarrow, J.E.

    2007-01-01

    Water-quality managers desire information on the temporal and spatial variability of contaminant concentrations and the magnitudes of watershed and bed-sediment loads in San Francisco Bay. To help provide this information, the Regional Monitoring Program for Trace Substances in the San Francisco Estuary (RMP) takes advantage of the association of many contaminants with sediment particles by continuously measuring suspended-sediment concentration (SSC), which is an accurate, less costly, and more easily measured surrogate for several trace metals and organic contaminants. Continuous time series of SSC are collected at several sites in the Bay. Although semidiurnal and diurnal tidal fluctuations are present, most of the variability of SSC occurs at fortnightly, monthly, and semiannual tidal time scales. A seasonal cycle of sediment inflow, wind-wave resuspension, and winnowing of fine sediment also is observed. SSC and, thus, sediment-associated contaminants tend to be greater in shallower water, at the landward ends of the Bay, and in several localized estuarine turbidity maxima. Although understanding of sediment transport has improved in the first 10 years of the RMP, determining a simple mass budget of sediment or associated contaminants is confounded by uncertainties regarding sediment flux at boundaries, change in bed-sediment storage, and appropriate modeling techniques. Nevertheless, management of sediment-associated contaminants has improved greatly. Better understanding of sediment and sediment-associated contaminants in the Bay is of great interest to evaluate the value of control actions taken and the need for additional controls. ?? 2007 Elsevier Inc. All rights reserved.

  17. Strontium-90 in human bone: 1981 results for New York City and San Francisco

    International Nuclear Information System (INIS)

    Klusek, C.S.

    1982-01-01

    Results are presented of determinations of Sr-90 content of 102 specimens of vertebrae obtained during 1981 in New York City and San Francisco. The average Sr-90 to Ca ratios for adult vertebrae are 0.95 pCi/g Ca (0.037 Bq/g Ca) in New York and 0.61 pCi/g Ca (0.023 Bq/g Ca) in San Francisco, little changed from the average values of the previous year. Average Sr-90 concentrations in children's bone are now little different from the adult values. A two compartment bone model, which accounts for both short and long term retention of Sr-90 in bone, is used to describe the variations of Sr-90 content of bone and provide correlation with dietary Sr-90 intake. Regression analysis of the 21 years of survey data provides values of the relative retention of dietary Sr-90 and the effective bone turnover rates. The bone model gives satisfactory description of observed Sr-90 levels and allows reliable assessment of the long-term behavior of Sr-90 in man

  18. Strontium-90 in human bone: 1980 results for New York City and San Francisco

    International Nuclear Information System (INIS)

    Klusek, C.S.

    1981-01-01

    Results are presented of determinations of 90 Sr content of 75 specimens of vertebrae obtained during 1980 in New York City and San Francisco. The average 90 Sr to Ca ratios for adult vertebrae are 0.95 pCi/g Ca (0.037 Bq/g Ca) in New York and 0.60 pCi/g Ca (0.022 Bq/g Ca) in San Francisco, little changed from the average values of the previous year. Average 90 Sr concentrations in children's bone are now little different from the adult values. A two compartment bone model, which accounts for both short and long term retention of 90 Sr in bone, is used to describe the variations of 90 Sr content of bone and provide correlation with dietary 90 Sr intake. Regression analysis of the 20 years of survey data provides values of the relative retention of dietary 90 Sr and the effective bone turnover rates. The bone model gives satisfactory description of observed 90 Sr levels and allows reliable assessment of the long-term behavior of 90 Sr in man

  19. Secciones en doble T Invertida en el aeropuerto de San Francisco – (EE. UU.

    Directory of Open Access Journals (Sweden)

    Lin, T. Y.

    1972-05-01

    Full Text Available In the carrying out of this work of enlarging the San Francisco International Airport, a criterion has been maintained which has allowed a series of interesting results to be obtained. The building technique is very unusual, giving it the mark of innovation. This technique has made use of prestressed, prefabricated parts, thus reducing by about 40 % the amount of materials that ordinary building methods would have required, lightening the loads, and keeping as far as possible within the limitations imposed by traffic and the terrain. And all without detriment to a considerable aesthetic effect.En la realización de esta obra para la ampliación del aeropuerto internacional de San Francisco se ha mantenido un criterio que ha permitido obtener una serie de resultados interesantes. Presenta un carácter innovador, ya que la técnica constructiva es muy poco habitual. Dicha técnica ha facilitado emplear elementos prefabricados pretensados, reducir en un 40 % la cantidad de materiales que hubieran sido necesarios de haber utilizado una técnica de construcción normal, aligerar las cargas y ceñirse al máximo a una serie de limitaciones impuestas por el tráfico y la naturaleza del terreno; todo ello sin detrimento de obtener un efecto estético considerable.

  20. Three-dimensional Modeling of Tidal Hydrodynamics in the San Francisco Estuary

    Directory of Open Access Journals (Sweden)

    Edward S. Gross

    2010-01-01

    Full Text Available Simulations of circulation in the San Francisco Estuary were performed with the three-dimensional TRIM3D hydrodynamic model using a generic length scale turbulence closure. The model was calibrated to reproduce observed tidal elevations, tidal currents, and salinity observations in the San Francisco Estuary using data collected during 1996-1998, a period of high and variable freshwater flow. It was then validated for 1994-1995, with emphasis on spring of 1994, a period of intensive data collection in the northern estuary. The model predicts tidal elevations and tidal currents accurately, and realistically predicts salinity at both the seasonal and tidal time scales. The model represents salt intrusion into the estuary accurately, and therefore accurately represents the salt balance. The model’s accuracy is adequate for its intended purposes of predicting salinity, analyzing gravitational circulation, and driving a particle-tracking model. Two applications were used to demonstrate the utility of the model. We estimated the components of the longitudinal salt flux and examined their dependence on flow conditions, and compared predicted salt intrusion with estimates from two empirical models.

  1. Final report for sea-level rise response modeling for San Francisco Bay estuary tidal marshes

    Science.gov (United States)

    Takekawa, John Y.; Thorne, Karen M.; Buffington, Kevin J.; Spragens, Kyle A.; Swanson, Kathleen M.; Drexler, Judith Z.; Schoellhamer, David H.; Overton, Cory T.; Casazza, Michael L.

    2013-01-01

    The International Panel on Climate Change has identified coastal ecosystems as areas that will be disproportionally affected by climate change. Current sea-level rise projections range widely with 0.57 to 1.9 meters increase in mea sea level by 2100. The expected accelerated rate of sea-level rise through the 21st century will put many coastal ecosystems at risk, especially those in topographically low-gradient areas. We assessed marsh accretion and plant community state changes through 2100 at 12 tidal salt marshes around San Francisco Bay estuary with a sea-level rise response model. Detailed ground elevation, vegetation, and water level data were collected at all sites between 2008 and 2011 and used as model inputs. Sediment cores (taken by Callaway and others, 2012) at four sites around San Francisco Bay estuary were used to estimate accretion rates. A modification of the Callaway and others (1996) model, the Wetland Accretion Rate Model for Ecosystem Resilience (WARMER), was utilized to run sea-level rise response models for all sites. With a mean sea level rise of 1.24 m by 2100, WARMER projected that the vast majority, 95.8 percent (1,942 hectares), of marsh area in our study will lose marsh plant communities by 2100 and to transition to a relative elevation range consistent with mudflat habitat. Three marshes were projected to maintain marsh vegetation to 2100, but they only composed 4.2 percent (85 hectares) of the total marsh area surveyed.

  2. Microphytobenthos potential productivity estimated in three tidal embayments of the San Francisco Bay system

    Science.gov (United States)

    Guarini, Jean-Marc; Cloern, James E.; Edmunds, Jody L.; Gros, Philippe

    2002-01-01

    In this paper we describe a three-step procedure to infer the spatial heterogeneity in microphytobenthos primary productivity at the scale of tidal estuaries and embayments. The first step involves local measurement of the carbon assimilation rate of benthic microalgae to determine the parameters of the photosynthesis-irradiance (P-E) curves (using non-linear optimization methods). In the next step, a resampling technique is used to rebuild pseudo-sampling distributions of the local productivity estimates; these provide error estimates for determining the significance level of differences between sites. The third step combines the previous results with deterministic models of tidal elevation and solar irradiance to compute mean and variance of the daily areal primary productivity over an entire intertidal mudflat area within each embayment. This scheme was applied on three different intertidal mudflat regions of the San Francisco Bay estuary during autumn 1998. Microphytobenthos productivity exhibits strong (ca. 3-fold) significant differences among the major sub-basins of San Francisco Bay. This spatial heterogeneity is attributed to two main causes: significant differences in the photosynthetic competence (P-E parameters) of the microphytobenthos in the different sub-basins, and spatial differences in the phase shifts between the tidal and solar cycles controlling the exposure of intertidal areas to sunlight. The procedure is general and can be used in other estuaries to assess the magnitude and patterns of spatial variability of microphytobenthos productivity at the level of the ecosystems.

  3. Microphytobenthic potential productivity estimated in three tidal embayments of the San Francisco Bay: A comparative study

    Science.gov (United States)

    Guarini, J.-M.; Cloern, James E.; Edmunds, J.

    2002-01-01

    In this paper we describe a three-step procedure to infer the spatial heterogeneity in microphytobenthos primary productivity at the scale of tidal estuaries and embayments. The first step involves local measurement of the carbon assimilation rate of benthic microalgae to determine the parameters of the photosynthesis-irradiance (P-E) curves (using non-linear optimization methods). In the next step, a resampling technique is used to rebuild pseudo-sampling distributions of the local productivity estimates; these provide error estimates for determining the significance level of differences between sites. The third step combines the previous results with deterministic models of tidal elevation and solar irradiance to compute mean and variance of the daily areal primary productivity over an entire intertidal mudflat area within each embayment. This scheme was applied on three different intertidal mudflat regions of the San Francisco Bay estuary during autumn 1998. Microphytobenthos productivity exhibits strong (ca. 3-fold) significant differences among the major sub-basins of San Francisco Bay. This spatial heterogeneity is attributed to two main causes: significant differences in the photosynthetic competence (P-E parameters) of the microphytobenthos in the different sub-basins, and spatial differences in the phase shifts between the tidal and solar cycles controlling the exposure of intertidal areas to sunlight. The procedure is general and can be used in other estuaries to assess the magnitude and patterns of spatial variability of microphytobenthos productivity at the level of the ecosystems.

  4. In-situ measurements of seismic velocities in the San Francisco Bay region...part II

    Science.gov (United States)

    Gibbs, James F.; Fumal, Thomas E.; Borcherdt, Roger D.

    1976-01-01

    Seismic wave velocities (compressional and shear) are important parameters for determining the seismic response characteristics of various geologic units when subjected to strong earthquake ground shaking. Seismic velocities of various units often show a strong correlation with the amounts of damage following large earthquakes and have been used as a basis for certain types of seismic zonation studies. Currently a program is in progress to measure seismic velocities in the San Francisco Bay region at an estimated 150 sites. At each site seismic travel times are measured in drill holes, normally at 2.5-m intervals to a depth of 30 m. Geologic logs are determined from drill hole cuttings, undisturbed samples, and penetrometer samples. The data provide a detailed comparison of geologic and seismic characteristics and provide parameters for estimating strong earthquake ground motions quantitatively at each of the site. A major emphasis of this program is to obtain a detailed comparison of geologic and seismic data on a regional scale for use in seismic zonation. The broad data base available in the San Francisco Bay region suggests using the area as a pilot area for the development of general techniques applicable to other areas.

  5. Literature Review of Unconsolidated Sediment in San Francisco Bay and Nearby Pacific Ocean Coast

    Directory of Open Access Journals (Sweden)

    Barry R. Keller

    2009-09-01

    Full Text Available A review of the geologic literature regarding sedimentation in the San Francisco Bay estuarine system shows that the main part of the bay occupies a structural tectonic depression that developed in Pleistocene time. Eastern parts, including San Pablo Bay and Suisun Bay, have had sedimentation throughout late Mesozoic and Tertiary. Carquinez Strait and the Golden Gate may represent antecedent stream erosion. Sedimentation has included estuarine, alluvial, and eolian deposition. The ages of estuarine deposition includes the modern high sea level stand and earlier Pleistocene interglacial periods. Sediment sources can be generally divided into the Coast Ranges, particularly the Franciscan Complex, and “Sierran.” Much of the estuarine system is floored by very fine sediment, with local areas of sand floor. Near the Golden Gate, sediment size decreases in both directions away from the deep channel. Bedforms include sand waves (submarine dunes, flat beds, and rock and boulders. These are interpreted in terms of dominant transport directions. Near the Golden Gate is an ebb-tidal delta on the outside (including San Francisco bar and a flood-tidal delta on the inside (parts of Central Bay. The large tidal prism causes strong tidal currents, which in the upper part of the estuary are normally much stronger than river currents, except during large floods. Cultural influences have altered conditions, including hydraulic mining debris, blasting of rocks, dredging of navigation channels, filling of the bay, and commercial sand mining. Many of these have served to decrease the tidal prism, correspondingly decreasing the strength of tidal currents.

  6. Distribution and Invasion Potential of Limonium ramosissimum subsp. provinciale in San Francisco Estuary Salt Marshes

    Directory of Open Access Journals (Sweden)

    Gavin Archbald

    2014-06-01

    Full Text Available Non-native sea lavenders (Limonium spp. are invasive in salt marshes of southern California and were first documented in the San Francisco Estuary (the estuary in 2007. In this study, we mapped distributions of L. ramosissimum subsp. provinciale (LIRA and L. duriusculum within the estuary and investigated how the invasion potential of the more common species, LIRA, varies with elevation and edaphic conditions. We contacted colleagues and conducted field searches to find and then map sea lavender populations. In addition, we measured LIRA’s elevational range at three salt marshes. Across this range we measured (1 soil properties: salinity, moisture, bulk density, and texture; and (2 indicators of invasion potential: LIRA size, seed production, percent cover, spread (over 1 year, recruitment, and competition with native halophytes (over 6 months. We found LIRA in 15,144 m2 of upper salt marsh habitat in central and south San Francisco bays and L. duriusculum in 511 m2 in Richardson and San Pablo bays. LIRA was distributed from mean high water (MHW to 0.42 m above mean higher high water (MHHW. In both spring and summer, soil moisture and salinity were lowest at higher elevations within LIRA’s range, which corresponded with greater rosette size, inflorescence and seed production (up to 17,400 seeds per plant, percent cover, and recruitment. LIRA cover increased on average by 11% in 1 year across marshes and elevations. Cover of the native halophytes Salicornia pacifica, Jaumea carnosa, and Distichlis spicata declined significantly at all elevations if LIRA were present in plots (over a 6-month, fall–winter period. Results suggest LIRA’s invasion potential is highest above MHHW where salinity and moisture are lower, but that LIRA competes with native plants from MHW to above MHHW. We recommend removal efforts with emphasis on the salt marsh-terrestrial ecotone where LIRA seed output is highest.

  7. Maps of Quaternary Deposits and Liquefaction Susceptibility in the Central San Francisco Bay Region, California

    Science.gov (United States)

    Witter, Robert C.; Knudsen, Keith L.; Sowers, Janet M.; Wentworth, Carl M.; Koehler, Richard D.; Randolph, Carolyn E.; Brooks, Suzanna K.; Gans, Kathleen D.

    2006-01-01

    This report presents a map and database of Quaternary deposits and liquefaction susceptibility for the urban core of the San Francisco Bay region. It supercedes the equivalent area of U.S. Geological Survey Open-File Report 00-444 (Knudsen and others, 2000), which covers the larger 9-county San Francisco Bay region. The report consists of (1) a spatial database, (2) two small-scale colored maps (Quaternary deposits and liquefaction susceptibility), (3) a text describing the Quaternary map and liquefaction interpretation (part 3), and (4) a text introducing the report and describing the database (part 1). All parts of the report are digital; part 1 describes the database and digital files and how to obtain them by downloading across the internet. The nine counties surrounding San Francisco Bay straddle the San Andreas fault system, which exposes the region to serious earthquake hazard (Working Group on California Earthquake Probabilities, 1999). Much of the land adjacent to the Bay and the major rivers and streams is underlain by unconsolidated deposits that are particularly vulnerable to earthquake shaking and liquefaction of water-saturated granular sediment. This new map provides a consistent detailed treatment of the central part of the 9-county region in which much of the mapping of Open-File Report 00-444 was either at smaller (less detailed) scale or represented only preliminary revision of earlier work. Like Open-File Report 00-444, the current mapping uses geomorphic expression, pedogenic soils, inferred depositional environments, and geologic age to define and distinguish the map units. Further scrutiny of the factors controlling liquefaction susceptibility has led to some changes relative to Open-File Report 00-444: particularly the reclassification of San Francisco Bay mud (Qhbm) to have only MODERATE susceptibility and the rating of artificial fills according to the Quaternary map units inferred to underlie them (other than dams - adf). The two colored

  8. 76 FR 54529 - Notice To Rescind a Notice of Intent To Prepare an Environmental Impact Statement: San Francisco...

    Science.gov (United States)

    2011-09-01

    ..., Acting Director, Local Programs, Federal Highway Administration, Sacramento, CA. [FR Doc. 2011-22349... To Prepare an Environmental Impact Statement: San Francisco County, CA AGENCY: Federal Highway..., Oakland, California 94623-0660, Telephone: (510) 286-5231, E-mail: [email protected]ca.gov...

  9. Risk Behaviors among Asian Women Who Work at Massage Parlors in San Francisco: Perspectives from Masseuses and Owners/Managers

    Science.gov (United States)

    Nemoto, Tooru; Iwamoto, Mariko; Oh, Hyun Joo; Wong, Serena; Nguyen, Hongmai

    2005-01-01

    This study investigates cognitive, cultural, and contextual factors that influence HIV-related risk behaviors among Asian women who engage in sex work at massage parlors in San Francisco. Focus groups and qualitative interviews were conducted for Vietnamese and Thai masseuses and massage parlor owners/managers. Economic pressure as well as…

  10. Sea change under climate change: case studies in rare plant conservation from the dynamic San Francisco Estuary

    Science.gov (United States)

    We present case studies supporting management of two rare plant species in tidal wetlands of the San Francisco Estuary. For an annual hemiparasite, we used demographic analyses to identify factors to enhance population establishment, survivorship and fitness, and to compare reintroduced with natura...

  11. Comparative analysis of long-term chlorophyll data with generalized additive model - San Francisco Bay and St. Lucie Estuary

    Science.gov (United States)

    The health of estuarine ecosystems is often influenced by hydraulic and nutrient loading from upstream watersheds. We examined four decades of monitoring data of nutrient export into the Indian River Lagoon and San Francisco Bay, both of which have received considerable attentio...

  12. Identifying Telemedicine Services to Improve Access to Specialty Care for the Underserved in the San Francisco Safety Net

    Directory of Open Access Journals (Sweden)

    Ken Russell Coelho

    2011-01-01

    Full Text Available Safety-net settings across the country have grappled with providing adequate access to specialty care services. San Francisco General Hospital and Trauma Center, serving as the city's primary safety-net hospital, has also had to struggle with the same issue. With Healthy San Francisco, the City and County of San Francisco's Universal Healthcare mandate, the increased demand for specialty care services has placed a further strain on the system. With the recent passage of California Proposition 1D, infrastructural funds are now set aside to assist in connecting major hospitals with primary care clinics in remote areas all over the state of California, using telemedicine. Based on a selected sample of key informant interviews with local staff physicians, this study provides further insight into the current process of e-referral which uses electronic communication for making referrals to specialty care. It also identifies key services for telemedicine in primary and specialty care settings within the San Francisco public health system. This study concludes with proposals for a framework that seek to increase collaboration between the referring primary care physician and specialist, to prioritize institution of these key services for telemedicine.

  13. Providing Specialty Care for the Poor and Underserved at Student-Run Free Clinics in the San Francisco Bay Area.

    Science.gov (United States)

    Liu, Max Bolun; Xiong, Grace; Boggiano, Victoria Lynn; Ye, Patrick Peiyong; Lin, Steven

    2017-01-01

    This report describes the model of specialty clinics implemented at Stanford University's two student-run free clinics, Arbor Free Clinic and Pacific Free Clinic, in the San Francisco Bay Area. We describe our patient demographic characteristics and the specialty services provided. We discuss challenges in implementing specialty care at student-run free clinics.

  14. Novel Analyses of Long-Term Data Provide a Scientific Basis for Chlorophyll-a Thresholds in San Francisco Bay

    Science.gov (United States)

    San Francisco Bay (SFB), USA, is highly enriched in nitrogen and phosphorus, but has been resistant to the classic symptoms of eutrophication associated with over-production of phytoplankton. Observations in recent years suggest that this resistance may be weakening, shown by: si...

  15. Density and elevational distribution of the San Francisco Peaks ragwort, Packera franciscana (Asteraceae), a threatened single-mountain endemic

    Science.gov (United States)

    James F. Fowler; Carolyn Hull Sieg

    2011-01-01

    Packera franciscana (Greene) W. A. Weber and A. Love is endemic to treeline and alpine habitats of the San Francisco Peaks, Arizona, USA and was listed as a threatened species under the Endangered Species Act in 1983. Species abundance data are limited in scope, yet are critical for recovery of the species, especially in light of predictions of its future extinction...

  16. Ground motion modeling of the 1906 San Francisco earthquake II: Ground motion estimates for the 1906 earthquake and scenario events

    Energy Technology Data Exchange (ETDEWEB)

    Aagaard, B; Brocher, T; Dreger, D; Frankel, A; Graves, R; Harmsen, S; Hartzell, S; Larsen, S; McCandless, K; Nilsson, S; Petersson, N A; Rodgers, A; Sjogreen, B; Tkalcic, H; Zoback, M L

    2007-02-09

    We estimate the ground motions produced by the 1906 San Francisco earthquake making use of the recently developed Song et al. (2008) source model that combines the available geodetic and seismic observations and recently constructed 3D geologic and seismic velocity models. Our estimates of the ground motions for the 1906 earthquake are consistent across five ground-motion modeling groups employing different wave propagation codes and simulation domains. The simulations successfully reproduce the main features of the Boatwright and Bundock (2005) ShakeMap, but tend to over predict the intensity of shaking by 0.1-0.5 modified Mercalli intensity (MMI) units. Velocity waveforms at sites throughout the San Francisco Bay Area exhibit characteristics consistent with rupture directivity, local geologic conditions (e.g., sedimentary basins), and the large size of the event (e.g., durations of strong shaking lasting tens of seconds). We also compute ground motions for seven hypothetical scenarios rupturing the same extent of the northern San Andreas fault, considering three additional hypocenters and an additional, random distribution of slip. Rupture directivity exerts the strongest influence on the variations in shaking, although sedimentary basins do consistently contribute to the response in some locations, such as Santa Rosa, Livermore, and San Jose. These scenarios suggest that future large earthquakes on the northern San Andreas fault may subject the current San Francisco Bay urban area to stronger shaking than a repeat of the 1906 earthquake. Ruptures propagating southward towards San Francisco appear to expose more of the urban area to a given intensity level than do ruptures propagating northward.

  17. What We Have Learned from San Francisco Declaration on Research Assessment and Leiden Manifesto?

    Directory of Open Access Journals (Sweden)

    Carey Ming-Li Chen

    2017-03-01

    Full Text Available In recent years, the research performance evaluation of members of the academic community conducted by government or institutions has been applied with multiple indicators and peer review, however, there are many controversies about the design and application of research evaluation indicators. This article aims to introduce the development process of San Francisco Declaration on Research Assessment (DORA and Leiden Manifesto and summarize their contents of guidelines and attempts to compare the differences between these two documents. It hopes that this article can arise the attention and reflection of research evaluation indicators and relevant issues from Taiwan academic community to reach consensus of utilization of research evaluation indicators. It will be beneficial to develop the version of declaration with local characteristics in the future.

  18. Masculinity and undocumented labor migration: injured latino day laborers in San Francisco

    Science.gov (United States)

    Walter, Nicholas; Bourgois, Philippe; Loinaz, H. Margarita

    2009-01-01

    Drawing on data collected through clinical practice and ethnographic fieldwork, this study examines the experience of injury, illness and disability among undocumented Latino day laborers in San Francisco. We demonstrate how constructions of masculine identity organize the experience of embodied social suffering among workers who are rendered vulnerable by the structural conditions of undocumented immigrant status. Theoretical concepts from critical medical anthropology and gender studies extend the scholarly analysis of structural violence beyond the primarily economic to uncover how it is embodied at the intimate level as a gendered experience of personal and familial crisis, involving love, respect, betrayal and patriarchal failure. A clinical ethnographic focus on socially structured patriarchal suffering elucidates the causal relationship between macro-forces and individual action with a fuller appreciation of the impact of culture and everyday lived experience. PMID:15210088

  19. 1993 Annual Report: San Francisco estuary regional monitoring program for trace substances

    Science.gov (United States)

    Thompson, B.; Lacy, Jessica; Hardin, Dane; Grovhaug, Tom; Taberski, K.; Jassby, Alan D.; Cloern, James E.; Caffrey, J.; Cole, B.; Schoellhamer, David H.

    1993-01-01

    This first annual report of the San Francisco Estuary Regional Monitoring Program contains the results of monitoring measurements made in 1993. Measurements of conventional water quality parameters and trace contaminant concentrations were made at 16 stations throughout the Estuary three times during the year: the wet period (March), during declining Delta outflow (May), and during the dry period (September). Water toxicity tests were conducted at 8 of those stations. Measurements of sediment quality and contaminant concentrations were made at the same 16 stations during the wet and dry sampling periods. Sediment toxicity was measured at 8 of those stations. Transplanted, bagged bivalve bioaccumulation and condition was measured at 11 stations during the wet and dry sampling periods.

  20. La desconocida historia de la construcción de la iglesia de San Francisco

    Directory of Open Access Journals (Sweden)

    Susan V. Webster

    2012-07-01

    Full Text Available El presente artículo ofrece una nueva cronología e historia de la construcción de la iglesia de San Francisco de Quito a través de documentos históricos inéditos que demuestran, contrariamente a lo postulado en la historiografìa tradicional, que la actual iglesia no fue construida en el siglo XVI. El estudio ilustra los participantes y el proceso de construcción, empleando documentos, planos e imágenes. Se abarcan temas de autoría, particularmente las identidades de los diseñadoresy constructores, y se ofrece una reconsideración del legado historiográfico del imponente templo franciscano a la vista de la nueva documentación

  1. BRICKS, BRANDING, AND THE EVERYDAY: DEFINING GREATNESS AT THE UNITED NATIONS PLAZA IN SAN FRANCISCO

    Directory of Open Access Journals (Sweden)

    Georgia Lindsay

    2017-07-01

    Full Text Available After over a decade of reports, designs, and public outreach, the United Nations Plaza in San Francisco was dedicated in 1976. Using historical documents such as government reports, design guidelines, letters, meeting minutes, and newspaper articles from archives, I argue that while the construction of the UN Plaza has failed to completely transform the social and economic life of the area, it succeeds in creating a genuinely public space. The history of the UN Plaza can serve both as a cautionary tale for those interested in changing property values purely through changing design, and as a standard of success in making a space used by a true cross-section of urban society.

  2. User's guide to the LIRAQ model: an air pollution model for the San Francisco Bay Area

    International Nuclear Information System (INIS)

    MacCracken, M.C.

    1975-01-01

    The Livermore Regional Air Quality (LIRAQ) model comprises a set of computer programs that have been integrated into an easily used tool for the air quality planner. To assemble and modify the necessary data files and to direct model execution, a problem formulation program has been developed that makes possible the setup of a wide variety of studies involving perturbation of the emission inventory, changes to the initial and boundary conditions, and different choices of grid size and problem domain. In addition to describing the types of air quality problems for which the LIRAQ model may be used, this User's Guide provides detailed information on how to set up and conduct model simulations. Also included are descriptions of the formats of input data files so that the LIRAQ model may be applied to regions other than the San Francisco Bay Area

  3. Modeling Sulfides, pH and Hydrogen Sulfide Gas in the Sewers of San Francisco

    DEFF Research Database (Denmark)

    Vollertsen, Jes; Revilla, Nohemy; Hvitved-Jacobsen, Thorkild

    2015-01-01

    An extensive measuring campaign targeted on sewer odor problems was undertaken in San Francisco. It was assessed whether a conceptual sewer process model could reproduce the measured concentrations of total sulfide in the wastewater and H2S gas in the sewer atmosphere, and to which degree...... such simulations have potential for further improving odor and sulfide management. The campaign covered measurement of wastewater sulfide by grab sampling and diurnal sampling, and H2S gas in the sewer atmosphere was logged. The tested model was based on the Wastewater Aerobic/Anaerobic Transformations in Sewers...... (WATS) sewer process concept, which never had been calibrated to such an extensive dataset. The study showed that the model was capable of reproducing the general levels of wastewater sulfide, wastewater pH, and sewer H2S gas. It could also reproduce the general variability of these parameters, albeit...

  4. Polychlorinated biphenyls in the exterior caulk of San Francisco Bay Area buildings, California, USA.

    Science.gov (United States)

    Klosterhaus, Susan; McKee, Lester J; Yee, Donald; Kass, Jamie M; Wong, Adam

    2014-05-01

    Extensive evidence of the adverse impacts of polychlorinated biphenyls (PCBs) to wildlife, domestic animals, and humans has now been documented for over 40 years. Despite the ban on production and new use of PCBs in the United States in 1979, a number of fish consumption advisories remain in effect, and there remains considerable uncertainty regarding ongoing environmental sources and management alternatives. Using a blind sampling approach, 25 caulk samples were collected from the exterior of ten buildings in the San Francisco Bay Area and analyzed for PCBs using congener-specific gas chromatography-mass spectrometry (GC-MS) and chlorine using portable X-ray fluorescence (XRF). PCBs were detected in 88% of the caulk samples collected from the study area buildings, with 40% exceeding 50 ppm. Detectable PCB concentrations ranged from 1 to 220,000 ppm. These data are consistent with previous studies in other cities that have identified relatively high concentrations of PCBs in concrete and masonry buildings built between 1950 and 1980. Portable XRF was not a good predictor of the PCB content in caulk and the results indicate that portable XRF analysis may only be useful for identifying caulk that contains low concentrations of Cl (≤ 10,000 ppm) and by extension low or no PCBs. A geographic information system-based approach was used to estimate that 10,500 kg of PCBs remain in interior and exterior caulk in buildings located in the study area, which equates to an average of 4.7 kg PCBs per building. The presence of high concentrations in the exterior caulk of currently standing buildings suggests that building caulk may be an ongoing source of PCBs to the San Francisco Bay Area environment. Further studies to expand the currently small international dataset on PCBs in caulking materials in buildings of countries that produced or imported PCBs appear justified in the context of both human health and possible ongoing environmental release. Copyright © 2014 Elsevier

  5. Improved Storm Monitoring and Prediction for the San Francisco Bay Area

    Science.gov (United States)

    Cifelli, R.; Chandrasekar, V.; Anderson, M.; Davis, G.

    2017-12-01

    The Advanced Quantitative Precipitation Information (AQPI) System is a multi-faceted project to improve precipitation and hydrologic monitoring, prediction, and decision support for the San Francisco Bay Area. The Bay Area faces a multitude of threats from extreme events, including disrupted transportation from flooded roads and railroad lines, water management challenges related to storm water, river and reservoir management and storm-related damage demanding emergency response. The threats occur on spatial scales ranging from local communities to the entire region and time scales ranging from hours to days. These challenges will be exacerbated by future sea level rise, more extreme weather events and increased vulnerabilities. AQPI is a collaboration of federal, state and local governments with assistance from the research community. Led by NOAA's Earth System Research Laboratory, in partnership with the Cooperative Institute for Research in the Atmosphere, USGS, and Scripps, AQPI is a four-year effort funded in part by a grant from the California Department of Water Resource's Integrated Regional Water Management Program. The Sonoma County Water Agency is serving as the local sponsor of the project. Other local participants include the Santa Clara Valley Water District, San Francisco Public Utilities Commission, and the Bay Area Flood Protection Agencies Association. AQPI will provide both improved observing capabilities and a suite of numerical forecast models to produce accurate and timely information for benefit of flood management, emergency response, water quality, ecosystem services, water supply and transportation management for the Bay Area. The resulting information will support decision making to mitigate flood risks, secure water supplies, minimize water quality impacts to the Bay from combined sewer overflows, and have improved lead-time on coastal and Bay inundation from extreme storms like Atmospheric Rivers (ARs). The project is expected to

  6. Unmet healthcare need among women who use methamphetamine in San Francisco.

    Science.gov (United States)

    Powelson, Elisabeth; Lorvick, Jennifer; Lutnick, Alexandra; Wenger, Lynn; Klausner, Jeffery; Kral, Alex H

    2014-02-01

    Methamphetamine use has increased substantially in the United States since the 1990s. Few studies have examined the healthcare service needs of women who use methamphetamine. This study describes unmet medical needs in a community-based sample of women who use methamphetamine in San Francisco, CA. Women who use methamphetamine were recruited in San Francisco and participated in a computer-assisted survey (N = 298 HIV-negative women). Multivariate analysis was performed to explore associations among sociodemographic variables, drug use, use of health and social services, and unmet healthcare need across three domains: chronic health problems, dermatologic problems, and women's preventive healthcare. Sixty-nine percent of participants reported a need for care for a chronic health condition, and 31% of them had an unmet need for care, in the last six months. Thirty-five percent of participants reported a need for dermatologic healthcare, and 66% had an unmet need for care in the last 6 months. Ninety-two percent of participants reported a need for women's preventive healthcare and 46% had an unmet need for care in the last year. Women who reported having a healthcare provider had lower odds of reporting an unmet need for a chronic health condition or women's preventive healthcare. Women who used a case manager had lower odds of having an unmet need for dermatologic care. A significant proportion of women who use methamphetamine in this sample had an unmet need for women's preventive healthcare, and overall these women had a significant unmet need for healthcare. These findings suggest that contact with a healthcare provider or a caseworker could help to expand access to healthcare for this vulnerable population.

  7. Religiosidad e identidad en San Francisco de Campeche. Siglos XVI y XVII

    Directory of Open Access Journals (Sweden)

    Rocher Salas, Adriana Delfina

    2006-12-01

    Full Text Available This study examines the problems concomitant to the development of a common identity among the Spanish settlers of San Francisco de Campeche during the Colonial period, with focus on the role played by religious elements in the shaping of this identity – in particular, the cult to the saints. An analysis of factors such as the characteristics of the saints in the neighborhood and local associations; processes of cult adoption, adaptation or dismissal; as well as the participation of the different local sectors in promoting the to their respective saints will be presented. This analysis will take into consideration the conflictive relationship between Spanish settlers and native people in Yucatán, a situation that prevented the using of aboriginal cultural elements in the shaping of a new identity

    Este trabajo estudia los problemas que acompañaron la gestación de una identidad propia y común para los residentes hispanos de la villa y puerto de San Francisco de Campeche durante el período colonial y la participación de elementos religiosos, particularmente el culto a los santos patronos, en el proceso. Teniendo como telón de fondo la peculiaridad de la región yucateca, donde una conflictiva relación entre españoles e indígenas impidió la utilización de elementos culturales prehispánicos en la formación de una conciencia identitaria, se analizan diversos factores, como las características de los santos tutelares de los barrios y de algunas corporaciones locales, los procesos de adopción, adaptación u olvido de sus cultos por parte del vecindario porteño y la participación de los diferentes sectores locales en la promoción de sus santos patronos.

  8. Structure and flow-induced variability of the subtidal salinity field in northern San Francisco Bay

    Science.gov (United States)

    Monismith, Stephen G.; Kimmerer, W.; Burau, J.R.; Stacey, M.T.

    2002-01-01

    The structure of the salinity field in northern San Francisco Bay and how it is affected by freshwater flow are discussed. Two datasets are examined: the first is 23 years of daily salinity data taken by the U.S. Bureau of Reclamation along the axis of northern San Francisco Bay: the second is a set of salinity transects taken by the U.S. Geological Survey between 1988 and 1993. Central to this paper is a measure of salinity intrusion. X2: the distance from the Golden Gate Bridge to where the bottom salinity is 2 psu. Using X2 to scale distance, the authors find that for most flow conditions, the mean salinity distribution of the estuary is nearly self-similar with a salinity gradient in the center 70% of the region between the Golden Gate and X2 that is proportional to X2-1. Analysis of covariability of Q and X2 showed a characteristics timescale of adjustment of the salinity field of approximately 2 weeks. The steady-state response deduced from the X2 time series implies that X2 is proportional to riverflow to the 1/7 power. This relation, which differs from the standard 1/3 power dependence that is derived theoretically assuming constant exchange coefficients, shows that the upstream salt flux associated with gravitational circulation is more sensitive to the longitudinal salinity gradient than theory supposes. This is attributed to the strengthening of stratification caused by the stronger longitudinal salinity gradient that accompanies larger river flows.

  9. State of transition: Marijuana use among young adults in the San Francisco Bay Area.

    Science.gov (United States)

    Holmes, Louisa M; Popova, Lucy; Ling, Pamela M

    2016-09-01

    California may vote on marijuana legalization in 2016. Young adults have the highest rates of marijuana use, but little is known about the correlates of use in this age group, including factors that may be affected by policy change. We investigated whether there are differences in marijuana use by sociodemographic characteristics, psychological distress, loneliness and social support, controlling for risk factors such as alcohol and cigarette use as well as perceived harm of marijuana. Bivariate and multivariable analysis of past 30day marijuana use using the 2014 San Francisco Bay Area Young Adult Health Survey, a probabilistic multi-mode survey of (N=1324) young adults (aged 18-26years) residing in Alameda and San Francisco Counties, stratified by race/ethnicity. 291 (27%) sample participants reported current marijuana use. Compared to non-Hispanic Whites (referent) Asian/Pacific Islander respondents were less likely to use marijuana (AOR, 0.42; 95% CI, 0.22-0.80) while multiracial participants were twice as likely (AOR, 2.27; 95% CI, 1.06-4.85). Psychological distress was not related to marijuana use, but social support (AOR, 1.42; 95% CI, 1.08-1.88) and loneliness (AOR, 1.42; 95% CI, 1.09-1.86) were. Perceived harm of marijuana was inversely related to marijuana use (AOR, 0.60; 95% CI, 0.51-0.70), while smoking cigarettes (AOR, 3.95; 95% CI, 2.28-6.84) and binge drinking (AOR, 1.13; 95% CI, 1.03-1.24) were positively related. Legalization policies should include public education campaigns addressing potential harms of marijuana use particularly targeting multiracial young adults who also engage in other risk behaviors, such as cigarette smoking and binge drinking. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Seismic velocities and geologic logs from boreholes at three downhole arrays in San Francisco, California

    Science.gov (United States)

    Gibbs, James F.; Fumal, Thomas E.; Borcherdt, Roger D.; Warrick, Richard E.; Liu, Hsi-Ping; Westerlund, Robert E.

    1994-01-01

    The Loma Prieta earthquake of October 17, 1989 (1704 PST), has reinforced observations made by Wood and others (1908) after the 1906 San Francisco earthquake, that poor ground conditions (soft soil) increase the likelihood of shaking damage to structures. Since 1908 many studies (for example Borcherdt, 1970, Borcherdt and Gibbs, 1976, Borcherdt and Glassmoyer, 1992) have shown that soft soils amplify seismic waves at frequencies that can be damaging to structures. Damage in the City of San Francisco from the Loma Prieta earthquake was concentrated in the Marina District, the Embarcadero, and the China Basin areas. Each of these areas, to some degree, is underlain by soft soil deposits. These concentrations of damage raise important questions regarding the amplification effects of such deposits at damaging levels of motion. Unfortunately, no strong-motion recordings were obtained in these areas during the Loma Prieta earthquake and only a limited number (< 10) have been obtained on other soft soil sites in the United States. Consequently, important questions exist regarding the response of such deposits during damaging earthquakes, especially questions regarding the nonlinear soil response. Towards developing a data set to address these important questions, borehole strong-motion arrays have been installed at three locations. These arrays consist of groups of wide-dynamic-range pore-pressure transducers and three-component accelerometers, the outputs of which are recorded digitally. The arrays are designed to provide an integrated set of data on ground shaking, liquifaction-induced ground failure, and structural response. This report describes the detailed geologic, seismic, and material-property determinations derived at each of these sites.

  11. Does Wind Discourage Sustainable Transportation Mode Choice? Findings from San Francisco, California, USA

    Directory of Open Access Journals (Sweden)

    Hyungkyoo Kim

    2016-03-01

    Full Text Available This paper explores whether and to what extent wind discourages sustainable transportation mode choice, which includes riding public transportation, bicycling, and walking. A six month-long field study was carried out at four locations in San Francisco, a city that has been promoting sustainable transportation mode choice but that experiences high wind levels. It involved surveying pedestrians and on-site recording of microclimate data using various instruments. The survey adopted a mixed-method approach to collect both quantitative and qualitative data. Statistical analyses using Kruskal Wallis tests and ordinal logistic regression models identified the significant effect of wind speed on San Francisco’s residents in estimating their discouragement for waiting at transit stop without shelter, bicycling, and walking. Qualitative data revealed a deeper understanding of how wind influences their sustainable transportation mode choice. This research argues for the need to adopt climate-based efforts in urban planning and policy and sheds light on the climate resilience of cities

  12. Avian communities in baylands and artificial salt evaporation ponds of the San Francisco Bay estuary

    Science.gov (United States)

    Takekawa, John Y.; Lu, C.T.; Pratt, R.T.

    2001-01-01

    San Francisco Bay wetlands, seasonal and tidal marshes between the historic low and high tide lines, are now highly fragmented because of development during the past 150 years. Artificial salt pond systems in the Bay are hypersaline and typically support simple assemblages of algae and invertebrates. In order to establish the value of salt ponds for migratory waterbirds, we used datasets to conduct a meta-analysis of avian communities in the baylands and salt ponds of San Pablo Bay. Fifty-three species of waterbirds in the salt ponds represented six foraging guilds: surface feeders, shallow probers, deep probers, dabblers, diving benthivores and piscivores. The total number of species and the Shannon-Weiner diversity index was higher in baylands than in salt ponds during all four seasons. However, overall bird density (number/ha) was higher in salt ponds compared with baylands in the winter and spring, primarily because of large concentrations of benthivores. Cessation of salt production in 1993 and subsequent reduction in water depth resulted in a decline of some diving duck populations that used the salt ponds.

  13. The Role of Tidal Marsh Restoration in Fish Management in the San Francisco Estuary

    Directory of Open Access Journals (Sweden)

    Bruce Herbold

    2014-03-01

    Full Text Available   Tidal marsh restoration is an important management issue in the San Francisco Estuary (estuary. Restoration of large areas of tidal marsh is ongoing or planned in the lower estuary (up to 6,000 ha, Callaway et al. 2011. Large areas are proposed for restoration in the upper estuary under the Endangered Species Act biological opinions (3,237 ha and the Bay Delta Conservation Plan (26,305 ha. In the lower estuary, tidal marsh has proven its value to a wide array of species that live within it (Palaima 2012. In the Sacramento–San Joaquin Delta (Delta, one important function ascribed to restoration of freshwater tidal marshes is that they make large contributions to the food web of fish in open waters (BDCP 2013. The Ecosystem Restoration Program ascribed a suite of ecological functions to tidal marsh restoration, including habitat and food web benefits to native fish (CDFW 2010. This background was the basis for a symposium, Tidal Marshes and Native Fishes in the Delta: Will Restoration Make a Difference? held at the University of California, Davis, on June 10, 2013. This paper summarizes conclusions the authors drew from the symposium. 

  14. Prediction of maximum earthquake intensities for the San Francisco Bay region

    Science.gov (United States)

    Borcherdt, Roger D.; Gibbs, James F.

    1975-01-01

    The intensity data for the California earthquake of April 18, 1906, are strongly dependent on distance from the zone of surface faulting and the geological character of the ground. Considering only those sites (approximately one square city block in size) for which there is good evidence for the degree of ascribed intensity, the empirical relation derived between 1906 intensities and distance perpendicular to the fault for 917 sites underlain by rocks of the Franciscan Formation is: Intensity = 2.69 - 1.90 log (Distance) (km). For sites on other geologic units intensity increments, derived with respect to this empirical relation, correlate strongly with the Average Horizontal Spectral Amplifications (AHSA) determined from 99 three-component recordings of ground motion generated by nuclear explosions in Nevada. The resulting empirical relation is: Intensity Increment = 0.27 +2.70 log (AHSA), and average intensity increments for the various geologic units are -0.29 for granite, 0.19 for Franciscan Formation, 0.64 for the Great Valley Sequence, 0.82 for Santa Clara Formation, 1.34 for alluvium, 2.43 for bay mud. The maximum intensity map predicted from these empirical relations delineates areas in the San Francisco Bay region of potentially high intensity from future earthquakes on either the San Andreas fault or the Hazard fault.

  15. Prediction of maximum earthquake intensities for the San Francisco Bay region

    Energy Technology Data Exchange (ETDEWEB)

    Borcherdt, R.D.; Gibbs, J.F.

    1975-01-01

    The intensity data for the California earthquake of Apr 18, 1906, are strongly dependent on distance from the zone of surface faulting and the geological character of the ground. Considering only those sites (approximately one square city block in size) for which there is good evidence for the degree of ascribed intensity, the empirical relation derived between 1906 intensities and distance perpendicular to the fault for 917 sites underlain by rocks of the Franciscan formation is intensity = 2.69 - 1.90 log (distance) (km). For sites on other geologic units, intensity increments, derived with respect to this empirical relation, correlate strongly with the average horizontal spectral amplifications (AHSA) determined from 99 three-component recordings of ground motion generated by nuclear explosions in Nevada. The resulting empirical relation is intensity increment = 0.27 + 2.70 log (AHSA), and average intensity increments for the various geologic units are -0.29 for granite, 0.19 for Franciscan formation, 0.64 for the Great Valley sequence, 0.82 for Santa Clara formation, 1.34 for alluvium, and 2.43 for bay mud. The maximum intensity map predicted from these empirical relations delineates areas in the San Francisco Bay region of potentially high intensity from future earthquakes on either the San Andreas fault or the Hayward fault.

  16. Shifting shoals and shattered rocks : How man has transformed the floor of west-central San Francisco Bay

    Science.gov (United States)

    Chin, John L.; Wong, Florence L.; Carlson, Paul R.

    2004-01-01

    San Francisco Bay, one of the world's finest natural harbors and a major center for maritime trade, is referred to as the 'Gateway to the Pacific Rim.' The bay is an urbanized estuary that is considered by many to be the major estuary in the United States most modified by man's activities. The population around the estuary has grown rapidly since the 1850's and now exceeds 7 million people. The San Francisco Bay area's economy ranks as one of the largest in the world, larger even than that of many countries. More than 10 million tourists are estimated to visit the bay region each year. The bay area's population and associated development have increasingly changed the estuary and its environment. San Francisco Bay and the contiguous Sacramento-San Joaquin Delta encompass roughly 1,600 square miles (4,100 km2) and are the outlet of a major watershed that drains more than 40 percent of the land area of the State of California. This watershed provides drinking water for 20 million people (two thirds of the State's population) and irrigates 4.5 million acres of farmland and ranchland. During the past several decades, much has been done to clean up the environment and waters of San Francisco Bay. Conservationist groups have even bought many areas on the margins of the bay with the intention of restoring them to a condition more like the natural marshes they once were. However, many of the major manmade changes to the bay's environment occurred so long ago that the nature of them has been forgotten. In addition, many changes continue to occur today, such as the introduction of exotic species and the loss of commercial and sport fisheries because of declining fish populations. The economy and population of the nine counties that surround the bay continue to grow and put increasing pressure on the bay, both direct and indirect. Therefore, there are mixed signals for the future health and welfare of San Francisco Bay. The San Francisco Bay estuary consists of three

  17. Empirical evidence for synchrony in the evolution of TB cases and HIV+ contacts among the San Francisco homeless.

    Directory of Open Access Journals (Sweden)

    Mojdeh Mohtashemi

    Full Text Available The re-emergence of tuberculosis (TB in the mid-1980s in many parts of the world, including the United States, is often attributed to the emergence and rapid spread of human immunodeficiency virus (HIV and acquired immunodeficiency syndrome (AIDS. Although it is well established that TB transmission is particularly amplified in populations with high HIV prevalence, the epidemiology of interaction between TB and HIV is not well understood. This is partly due to the scarcity of HIV-related data, a consequence of the voluntary nature of HIV status reporting and testing, and partly due to current practices of screening high risk populations through separate surveillance programs for HIV and TB. The San Francisco Department of Public Health, TB Control Program, has been conducting active surveillance among the San Francisco high-risk populations since the early 1990s. We present extensive TB surveillance data on HIV and TB infection among the San Francisco homeless to investigate the association between the TB cases and their HIV+ contacts. We applied wavelet coherence and phase analyses to the TB surveillance data from January 1993 through December 2005, to establish and quantify statistical association and synchrony in the highly non-stationary and ostensibly non-periodic waves of TB cases and their HIV+ contacts in San Francisco. When stratified by homelessness, we found that the evolution of TB cases and their HIV+ contacts is highly coherent over time and locked in phase at a specific periodic scale among the San Francisco homeless, but no significant association was observed for the non-homeless. This study confirms the hypothesis that the dynamics of HIV and TB are significantly intertwined and that HIV is likely a key factor in the sustenance of TB transmission among the San Francisco homeless. The findings of this study underscore the importance of contact tracing in detection of HIV+ individuals that may otherwise remain undetected, and

  18. Recent research on the hydrodynamics of the Sacramento - San Joaquin River Delta and north San Francisco Bay

    Science.gov (United States)

    Burau, J.R.; Monismith, S.G.; Stacey, M.T.; Oltmann, R.N.; Lacy, J.R.; Schoellhamer, D.H.

    1999-01-01

    This article presents an overview of recent findings from hydrodynamic research on circulation and mixing in the Sacramento-San Joaquin Delta (Delta) (Figure 1) and North San Francisco Bay (North Bay) (Figure 2). For the purposes of this article, North Bay includes San Pablo Bay, Carquinez Strait, and Suisun Bay. The findings presented are those gained from field studies carried out by the U.S. Geological Survey (USGS), as part of the Interagency Ecological Program (IEP), and Stanford University beginning about 1993. The premise behind these studies was that a basic understanding of circulation and mixing patterns in the Bay and Delta is an essential part of understanding how biota and water quality are affected by natural hydrologic variability, water appropriation, and development activities. Data collected for the field studies described in this article have significantly improved our understanding of Bay and Delta hydrodynamics. Measured flows ,in the Delta have provided valuable information on how water moves through the Delta's network of channels and how export pumping affects flows. Studies of the shallows and shallow-channel exchange processes conducted in Honker Bay have shown that the water residence time in Honker Bay is much shorter than previously reported (on the order of hours to several tidal cycles instead ofweeks). Suisun Bay studies have provided data on hydrodynamic transport and accumulation mechanisms that operate primarily in the channels. The Suisun Bay studies have caused us to revise our understanding of residual circulation in the channels of North Bay and of "entrapment" mechanisms in the low salinity zone. Finally, detailed tidal and residual (tidally averaged) time-scale studies of the mechanisms that control gravitational circulation in the estuary show that density-driven transport in the channels is governed by turbulence time-scale (seconds) interactions between the mean flow and stratification. The hydrodynamic research

  19. PCDD/F, PCB, HXCBZ, PAH, AND PM EMISSION FACTORS FOR FIREPLACE AND WOODSTOVE COMBUSTION IN THE SAN FRANCISCO BAY REGION

    Science.gov (United States)

    Emissions from residential fireplace and woodstove appliances burning fuels available from the San Francisco Bay area were sampled for polychlornated dibenzodioxins and dibenzofurans (PCDDs/Fs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HxCBz), particulatematter (P...

  20. University of California San Francisco (UCSF-2): Expression Analysis of Superior Cervical Ganglion from Backcrossed TH-MYCN Transgenic Mice | Office of Cancer Genomics

    Science.gov (United States)

    The CTD2 Center at University of California San Francisco (UCSF-2) used genetic analysis of the peripheral sympathetic nervous system to identify potential therapeutic targets in neuroblastoma. Read the abstract Experimental Approaches Read the detailed Experimental Approaches

  1. EX1006 Hawaii to San Francisco Transit to Drydock (EX1006, EM302) on Okeanos Explorer in Hawaii, US West Coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Okeanos Explorer (EX) will transit from Honolulu, HI to San Francisco for the winter inport and drydock period. During the transit, the EX will perform 24-hour...

  2. Acculturation, Dietary Practices and Risk for Childhood Obesity in an Ethnically Heterogeneous Population of Latino School Children in the San Francisco Bay Area

    OpenAIRE

    Wojcicki, Janet M.; Schwartz, Norah; Jiménez-Cruz, Arturo; Bacardi-Gascon, Montserrat; Heyman, Melvin B.

    2012-01-01

    Previous studies have found increased acculturation to the US lifestyle increases risk for obesity in Latinos. However, methodologies differ, and results in children are inconsistent. Moreover, previous studies have not evaluated risk factors within the heterogeneous US population. We recruited 144 self-identified Latino school children and their mother or father in grades 4–6 in San Francisco parochial schools and South San Francisco public schools using an information letter distributed to ...

  3. Data Files for Ground-Motion Simulations of the 1906 San Francisco Earthquake and Scenario Earthquakes on the Northern San Andreas Fault

    Science.gov (United States)

    Aagaard, Brad T.; Barall, Michael; Brocher, Thomas M.; Dolenc, David; Dreger, Douglas; Graves, Robert W.; Harmsen, Stephen; Hartzell, Stephen; Larsen, Shawn; McCandless, Kathleen; Nilsson, Stefan; Petersson, N. Anders; Rodgers, Arthur; Sjogreen, Bjorn; Zoback, Mary Lou

    2009-01-01

    This data set contains results from ground-motion simulations of the 1906 San Francisco earthquake, seven hypothetical earthquakes on the northern San Andreas Fault, and the 1989 Loma Prieta earthquake. The bulk of the data consists of synthetic velocity time-histories. Peak ground velocity on a 1/60th degree grid and geodetic displacements from the simulations are also included. Details of the ground-motion simulations and analysis of the results are discussed in Aagaard and others (2008a,b).

  4. The Performance of Nearshore Dredge Disposal at Ocean Beach, San Francisco, California, 2005-2007

    Science.gov (United States)

    Barnard, Patrick L.; Erikson, Li H.; Hansen, Jeff E.; Elias, Edwin

    2009-01-01

    Ocean Beach, California, contains an erosion hot spot in the shadow of the San Francisco ebb tidal delta that threatens valuable public infrastructure as well as the safe recreational use of the beach. In an effort to reduce the erosion at this location a new plan for the management of sediment dredged annually from the main shipping channel at the mouth of San Francisco Bay was implemented in May 2005 by the United States Army Corps of Engineers, San Francisco District (USACE). The USACE designated a temporary nearshore dredge disposal site for the annual disposal of about 230,000 m3 (300,000 yd3) of sand about 750 m offshore and slightly south of the erosion hot spot, in depths between approximately 9 and 14 m. The site has now been used three times for a total sediment disposal of about 690,000 m3 (about 900,000 yds3). The disposal site was chosen because it is in a location where strong tidal currents and open-ocean waves can potentially feed sediment toward the littoral zone in the reach of the beach that is experiencing critical erosion, as well as prevent further scour on an exposed outfall pipe. The onshore migration of sediment from the target disposal location might feed the primary longshore bar or the nearshore zone, and provide a buffer to erosion that peaks during winter months when large waves impact the region. The United States Geological Survey (USGS) has been monitoring and modeling the bathymetric evolution of the test dredge disposal site and the adjacent coastal region since inception in May 2005. This paper reports on the first 2.5 years of this monitoring program effort (May 2005 to December 2007) and assesses the short-term coastal response. Here are the key findings of this report: *Approximately half of the sediment that has been placed in the nearshore dredge-disposal site during the 2.5 years of this study remains within the dredge focus area. *In the winter of 2006-7, large waves transported the dredge-mound material onshore. *High

  5. Mercury in birds of San Francisco Bay-Delta, California: trophic pathways, bioaccumulation, and ecotoxicological risk to avian reproduction

    Science.gov (United States)

    Ackerman, Joshua T.; Eagles-Smith, Collin A.; Heinz, Gary; De La Cruz, Susan E. W.; Takekawa, John Y.; Miles, A. Keith; Adelsbach, Terrence L.; Herzog, Mark P.; Bluso-Demers, Jill D.; Demers, Scott A.; Herring, Garth; Hoffman, David J.; Hartman, Christopher A.; Willacker, James J.; Suchanek, Thomas H.; Schwarzbach, Steven E.; Maurer, Thomas C.

    2014-01-01

    San Francisco Bay Estuary in northern California has a legacy of mercury contamination, which could reduce the health and reproductive success of waterbirds in the estuary. The goal of this study was to use an integrated field and laboratory approach to evaluate the risks of mercury exposure to birds in the estuary. We examined mercury bioaccumulation, and other contaminants of concern, in five waterbird species that depend heavily on San Francisco Bay Estuary for foraging and breeding habitat: American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), Forster’s terns (Sterna forsteri), Caspian terns (Hydroprogne caspia), and surf scoters (Melanitta perspicillata). These species have different foraging habitats and diets that represent three distinct foraging guilds within the estuary’s food web. In this report, we provide an integrated synthesis of the primary findings from this study and results are synthesized from 54 peer-reviewed publications generated to date with other unpublished results.

  6. Part I, Introduction: Ecology and Regional Context of Tidal Wetlands in the San Francisco Bay National Estuarine Research Reserve

    Directory of Open Access Journals (Sweden)

    Matthew C. Ferner

    2011-12-01

    Full Text Available This two-part special issue reviews the basic ecology of tidal wetlands in the San Francisco Estuary. Several articles highlight the well-preserved tracts of historic tidal marsh found at China Camp State Park and Rush Ranch Open Space Preserve. These two protected areas serve as important reference sites for wetland restoration and conservation and also comprise San Francisco Bay National Estuarine Research Reserve (SF Bay NERR. SF Bay NERR is part of the National Oceanic and Atmospheric Administration’s nationwide network of 28 estuarine research reserves (http://www.nerrs.noaa.gov that all share common goals: (1 conducting standardized long-term monitoring, (2 supporting applied environmental research, (3 providing stewardship of estuarine natural resources, and (4 linking science with decision making in pursuit of effective solutions to coastal management problems.

  7. Crisis of the social and emergence of sociality in the new scenarios of identity. The San Francisco district of Bilbao

    Directory of Open Access Journals (Sweden)

    Beatriz Cavia

    2008-09-01

    Full Text Available The San Francisco district in Bilbao (Spain is undergoing a deep process of urban transformation in which there is a convergence of different dynamics —economic (property speculation, social (appearance of associations and social movements and political (rehabilitation plans. In order to explain this transformation, we test two hypotheses in the article: gentrification and the crisis of the social institutions (politics, religion and work that traditionally articulated society. To counterbalance the shortcomings of the two hypotheses we redefine them as mere “conditions of possibility” of the emergence of new forms of sociality, the depoliticisation of signifieds and the production of new spaces. San Francisco constitutes a variable cronotope that provokes a blurring in sociological configurations and in social norms and sanctions.

  8. Promoting Health and Safety in San Francisco's Chinatown Restaurants: Findings and Lessons Learned from a Pilot Observational Checklist

    Science.gov (United States)

    Gaydos, Megan; Bhatia, Rajiv; Morales, Alvaro; Lee, Pam Tau; Liu, Shaw San; Chang, Charlotte; Salvatore, Alicia L.; Krause, Niklas; Minkler, Meredith

    2011-01-01

    Noncompliance with labor and occupational health and safety laws contributes to economic and health inequities. Environmental health agencies are well positioned to monitor workplace conditions in many industries and support enhanced enforcement by responsible regulatory agencies. In collaboration with university and community partners, the San Francisco Department of Public Health used an observational checklist to assess preventable occupational injury hazards and compliance with employee notification requirements in 106 restaurants in San Francisco's Chinatown. Sixty-five percent of restaurants had not posted required minimum wage, paid sick leave, or workers' compensation notifications; 82% of restaurants lacked fully stocked first-aid kits; 52% lacked antislip mats; 37% lacked adequate ventilation; and 28% lacked adequate lighting. Supported by a larger community-based participatory research process, this pilot project helped to spur additional innovative health department collaborations to promote healthier workplaces. PMID:21836739

  9. Real-Time GPS Monitoring for Earthquake Rapid Assessment in the San Francisco Bay Area

    Science.gov (United States)

    Guillemot, C.; Langbein, J. O.; Murray, J. R.

    2012-12-01

    The U.S. Geological Survey Earthquake Science Center has deployed a network of eight real-time Global Positioning System (GPS) stations in the San Francisco Bay area and is implementing software applications to continuously evaluate the status of the deformation within the network. Real-time monitoring of the station positions is expected to provide valuable information for rapidly estimating source parameters should a large earthquake occur in the San Francisco Bay area. Because earthquake response applications require robust data access, as a first step we have developed a suite of web-based applications which are now routinely used to monitor the network's operational status and data streaming performance. The web tools provide continuously updated displays of important telemetry parameters such as data latency and receive rates, as well as source voltage and temperature information within each instrument enclosure. Automated software on the backend uses the streaming performance data to mitigate the impact of outages, radio interference and bandwidth congestion on deformation monitoring operations. A separate set of software applications manages the recovery of lost data due to faulty communication links. Displacement estimates are computed in real-time for various combinations of USGS, Plate Boundary Observatory (PBO) and Bay Area Regional Deformation (BARD) network stations. We are currently comparing results from two software packages (one commercial and one open-source) used to process 1-Hz data on the fly and produce estimates of differential positions. The continuous monitoring of telemetry makes it possible to tune the network to minimize the impact of transient interruptions of the data flow, from one or more stations, on the estimated positions. Ongoing work is focused on using data streaming performance history to optimize the quality of the position, reduce drift and outliers by switching to the best set of stations within the network, and

  10. Review of wastewater problems and wastewater-management planning in the San Francisco Bay region, California

    Science.gov (United States)

    Hines, Walter G.

    1973-01-01

    The San Francisco Bay region has suffered adverse environmental effects related to the discharge of municipal-, industrial-, and agricultural- wastewater and storm-water runoff. Specific pollutional properties of theses discharges are not well understood in all cases although the toxic materials and aquatic-plant nutrients (biostimulants) found in municipal and industrial waterwater are considered to be a major cause of regional water-quality problems. Other water-quality problems in the region are commonly attributed to pesticides found in agricultural wastewater and potentially pathogenic bacteria in municipal-wastewater discharges and in storm-water runoff. The geographical distribution and magnitude of wastewater discharges in the bay region, particularly those from municipalities and industries, is largely a function of population, economic growth, and urban development. As might be expected, the total volume of wastewater has increased in a trend paralleling this growth and development. More significant, perhaps, is the fact that the total volume parameters such as BOD (biochemical oxygen demand), biostimulant concentrations, and toxicity, has increased despite large expenditures on new and improved municipal- and industrial-wastewater-treatment plants. Also, pollutant loadings from other major source, such as agriculture and storm-water runoff, have increased. At the time of writing (1972), many Federal, State, regional, and local agencies are engaged in a comprehensive wastewater-management-planning effort for the entire bay region. Initial objectives of this planning effort are: (1) the consolidation and coordination of loosely integrated wastewater-management facilities and (2) the elimination of wastewater discharges to ecologically sensitive areas, such as fresh-water streams and shallow extremities of San Francisco Bay. There has been some investigation of potential long-range wastewater-management alternatives based upon disposal in deep water in the

  11. Understanding Urban Watersheds through Digital Interactive Maps, San Francisco Bay Area, California

    Science.gov (United States)

    Sowers, J. M.; Ticci, M. G.; Mulvey, P.

    2014-12-01

    Dense urbanization has resulted in the "disappearance" of many local creeks in urbanized areas surrounding the San Francisco Bay. Long reaches of creeks now flow in underground pipes. Municipalities and water agencies trying to reduce non-point-source pollution are faced with a public that cannot see and therefore does not understand the interconnected nature of the drainage system or its ultimate discharge to the bay. Since 1993, we have collaborated with the Oakland Museum, the San Francisco Estuary Institute, public agencies, and municipalities to create creek and watershed maps to address the need for public understanding of watershed concepts. Fifteen paper maps are now published (www.museumca.org/creeks), which have become a standard reference for educators and anyone working on local creek-related issues. We now present digital interactive creek and watershed maps in Google Earth. Four maps are completed covering urbanized areas of Santa Clara and Alameda Counties. The maps provide a 3D visualization of the watersheds, with cartography draped over the landscape in transparent colors. Each mapped area includes both Present and Past (circa 1800s) layers which can be clicked on or off by the user. The Present layers include the modern drainage network, watershed boundaries, and reservoirs. The Past layers include the 1800s-era creek systems, tidal marshes, lagoons, and other habitats. All data are developed in ArcGIS software and converted to Google Earth format. To ensure the maps are interesting and engaging, clickable icons pop-up provide information on places to visit, restoration projects, history, plants, and animals. Maps of Santa Clara Valley are available at http://www.valleywater.org/WOW.aspx. Maps of western Alameda County will soon be available at http://acfloodcontrol.org/. Digital interactive maps provide several advantages over paper maps. They are seamless within each map area, and the user can zoom in or out, and tilt, and fly over to explore

  12. Improving Radar Quantitative Precipitation Estimation over Complex Terrain in the San Francisco Bay Area

    Science.gov (United States)

    Cifelli, R.; Chen, H.; Chandrasekar, V.

    2017-12-01

    A recent study by the State of California's Department of Water Resources has emphasized that the San Francisco Bay Area is at risk of catastrophic flooding. Therefore, accurate quantitative precipitation estimation (QPE) and forecast (QPF) are critical for protecting life and property in this region. Compared to rain gauge and meteorological satellite, ground based radar has shown great advantages for high-resolution precipitation observations in both space and time domain. In addition, the polarization diversity shows great potential to characterize precipitation microphysics through identification of different hydrometeor types and their size and shape information. Currently, all the radars comprising the U.S. National Weather Service (NWS) Weather Surveillance Radar-1988 Doppler (WSR-88D) network are operating in dual-polarization mode. Enhancement of QPE is one of the main considerations of the dual-polarization upgrade. The San Francisco Bay Area is covered by two S-band WSR-88D radars, namely, KMUX and KDAX. However, in complex terrain like the Bay Area, it is still challenging to obtain an optimal rainfall algorithm for a given set of dual-polarization measurements. In addition, the accuracy of rain rate estimates is contingent on additional factors such as bright band contamination, vertical profile of reflectivity (VPR) correction, and partial beam blockages. This presentation aims to improve radar QPE for the Bay area using advanced dual-polarization rainfall methodologies. The benefit brought by the dual-polarization upgrade of operational radar network is assessed. In addition, a pilot study of gap fill X-band radar performance is conducted in support of regional QPE system development. This paper also presents a detailed comparison between the dual-polarization radar-derived rainfall products with various operational products including the NSSL's Multi-Radar/Multi-Sensor (MRMS) system. Quantitative evaluation of various rainfall products is achieved

  13. In-situ measurements of seismic velocities in the San Francisco Bay Region; part III

    Science.gov (United States)

    Gibbs, James F.; Fumal, Thomas E.; Borcherdt, Roger D.; Roth, Edward F.

    1977-01-01

    Seismic wave velocities (compressional and shear) are important parameters for estimating the seismic response characteristics of various geologic units when subjected to strong earthquake ground shaking. Seismic velocities of various units often show a strong correlation with the amounts of damage following large earthquakes and have been used as a basis for certain types of seismic zonation studies. In the current program seismic velocities have been measured at 59 locations 1n the San Francisco Bay Region. This report is the third in a series of Open-File Reports and describes the in-situ velocity measurements at locations 35-59. At each location seismic travel times are measured in drill holes, normally at 2.5-m intervals to a depth of 30 m. Geologic logs are determined from drill cuttings, undisturbed (cored) samples, and penetrometer samples. The data provide a detailed comparison of geologic and seismic characteristics and provide parameters for estimating strong earthquake ground motions quantitatively at each of the sites. A major emphasis of this program is to obtain a detailed comparison of geologic and seismic data on a regional scale for use in seismic zonation. There is a variety of geologic and seismic data available in the San Francisco Bay Region for use 1n developing the general zoning techniques which can then be applied to other areas. Shear wave velocities 1n near-surface geologic materials are of especial interest for engineering seismology and seismic zonation studies, yet in general, they are difficult to measure because of contamination by compressional waves. A comparison of various in-situ techniques by Warrick (1974) establishes the reliability of the method utilizing a "horizontal traction" source for sites underlain by bay mud and alluvium. Gibbs, and others (1975a) present data from 12 holes and establishes the reliability of the method for sites underlain by a variety of different rock units and suggest extending the measurements to

  14. Sub-tidal benthic habitats of central San Francisco Bay and offshore Golden Gate area: A review

    Science.gov (United States)

    Greene, H. Gary; Endris, Charles; Vallier, Tracy; Golden, Nadine E.; Cross, Jeffery; Ryan, Holly F.; Dieter, Bryan; Niven, Eric; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    Deep-water potential estuarine and marine benthic habitat types were defined from a variety of new and interpreted data sets in central San Francisco Bay and offshore Golden Gate area including multibeam echosounder (MBES), side-scan sonar and bottom grab samples. Potential estuarine benthic habitats identified for the first time range from hard bedrock outcrops on island and mainland flanks and some Bay floor

  15. Distribution and Genetic Structure of Fucus distichus Linnaeus 1953 (formerly F. gardneri within Central San Francisco Bay

    Directory of Open Access Journals (Sweden)

    Stephen G. Whitaker

    2017-09-01

    Full Text Available doi: https://doi.org/10.15447/sfews.2017v15iss3art4Fucus distichus, a rockweed common to the mid-intertidal shoreline within the San Francisco Estuary (previously known as F. gardneri, was injured during the Cosco Busan oil spill in November 2007 and subsequent clean-up actions. Restoration planning activities are underway to help recover F. distichus at sites within central San Francisco Bay where damage occurred. As a first step, we conducted shoreline surveys during the summers of 2012–2013 to map the occurrence of this rockweed. Of the 151.73 km of rocky shoreline within the central bay, F. distichus covered 32.16 km of shoreline. The alga generally occurred in narrow bands but formed expansive beds at locations with natural, flat bedrock benches. We also observed F. distichus on artificial substrata such as seawalls and riprap, but not on pilings. Samples of F. distichus from 11 sites throughout the central / east San Francisco Bay were genetically analyzed (microsatellite genotyping. The populations analyzed (1 had low genetic diversity, (2 the frequency of homozygotes was higher than expected (suggesting high inbreeding, and (3 also displayed geographic population structure, in part driven by very small differences in the midst of extremely low within-population genetic diversity. However, these genetic data do not raise concerns for restoration methods in terms of choosing donor populations and mixing F. distichus from different sites within the central bay. The choice of donor populations should be based on practical criteria for effective restoration; individuals will nonetheless be taken from locations as nearby to donor sites as possible. Various locations throughout the central San Francisco Bay are composed of cobble or small riprap that are populated with F. distichus, which could provide efficient means of translocating rockweed for future restoration activities.

  16. Achieving Health Equity Through Community Engagement in Translating Evidence to Policy: The San Francisco Health Improvement Partnership, 2010–2016

    Science.gov (United States)

    Vargas, Roberto A.; Fleisher, Paula; Aragón, Tomás J.; Chung, Lisa; Chawla, Colleen; Yant, Abbie; Garcia, Estela R.; Santiago, Amor; Lang, Perry L.; Jones, Paula; Liu, Wylie; Schmidt, Laura A.

    2017-01-01

    Background The San Francisco Health Improvement Partnership (SFHIP) promotes health equity by using a novel collective impact model that blends community engagement with evidence-to-policy translational science. The model involves diverse stakeholders, including ethnic-based community health equity coalitions, the local public health department, hospitals and health systems, a health sciences university, a school district, the faith community, and others sectors. Community Context We report on 3 SFHIP prevention initiatives: reducing consumption of sugar sweetened beverages (SSBs), regulating retail alcohol sales, and eliminating disparities in children’s oral health. Methods SFHIP is governed by a steering committee. Partnership working groups for each initiative collaborate to 1) develop and implement action plans emphasizing feasible, scalable, translational-science–informed interventions and 2) consider sustainability early in the planning process by including policy and structural interventions. Outcome Through SFHIP’s efforts, San Francisco enacted ordinances regulating sale and advertising of SSBs and a ballot measure establishing a soda tax. Most San Francisco hospitals implemented or committed to implementing healthy-beverage policies that prohibited serving or selling SSBs. SFHIP helped prevent Starbucks and Taco Bell from receiving alcohol licenses in San Francisco and helped prevent state authorization of sale of powdered alcohol. SFHIP increased the number of primary care clinics providing fluoride varnish at routine well-child visits from 3 to 14 and acquired a state waiver to allow dental clinics to be paid for dental services delivered in schools. Interpretation The SFHIP model of collective impact emphasizing community engagement and policy change accomplished many of its intermediate goals to create an environment promoting health and health equity. PMID:28333598

  17. Achieving Health Equity Through Community Engagement in Translating Evidence to Policy: The San Francisco Health Improvement Partnership, 2010-2016.

    Science.gov (United States)

    Grumbach, Kevin; Vargas, Roberto A; Fleisher, Paula; Aragón, Tomás J; Chung, Lisa; Chawla, Colleen; Yant, Abbie; Garcia, Estela R; Santiago, Amor; Lang, Perry L; Jones, Paula; Liu, Wylie; Schmidt, Laura A

    2017-03-23

    The San Francisco Health Improvement Partnership (SFHIP) promotes health equity by using a novel collective impact model that blends community engagement with evidence-to-policy translational science. The model involves diverse stakeholders, including ethnic-based community health equity coalitions, the local public health department, hospitals and health systems, a health sciences university, a school district, the faith community, and others sectors. We report on 3 SFHIP prevention initiatives: reducing consumption of sugar sweetened beverages (SSBs), regulating retail alcohol sales, and eliminating disparities in children's oral health. SFHIP is governed by a steering committee. Partnership working groups for each initiative collaborate to 1) develop and implement action plans emphasizing feasible, scalable, translational-science-informed interventions and 2) consider sustainability early in the planning process by including policy and structural interventions. Through SFHIP's efforts, San Francisco enacted ordinances regulating sale and advertising of SSBs and a ballot measure establishing a soda tax. Most San Francisco hospitals implemented or committed to implementing healthy-beverage policies that prohibited serving or selling SSBs. SFHIP helped prevent Starbucks and Taco Bell from receiving alcohol licenses in San Francisco and helped prevent state authorization of sale of powdered alcohol. SFHIP increased the number of primary care clinics providing fluoride varnish at routine well-child visits from 3 to 14 and acquired a state waiver to allow dental clinics to be paid for dental services delivered in schools. The SFHIP model of collective impact emphasizing community engagement and policy change accomplished many of its intermediate goals to create an environment promoting health and health equity.

  18. Achieving Health Equity Through Community Engagement in Translating Evidence to Policy: The San Francisco Health Improvement Partnership, 2010?2016

    OpenAIRE

    Grumbach, Kevin; Vargas, Roberto A.; Fleisher, Paula; Arag?n, Tom?s J.; Chung, Lisa; Chawla, Colleen; Yant, Abbie; Garcia, Estela R.; Santiago, Amor; Lang, Perry L.; Jones, Paula; Liu, Wylie; Schmidt, Laura A.

    2017-01-01

    Background The San Francisco Health Improvement Partnership (SFHIP) promotes health equity by using a novel collective impact model that blends community engagement with evidence-to-policy translational science. The model involves diverse stakeholders, including ethnic-based community health equity coalitions, the local public health department, hospitals and health systems, a health sciences university, a school district, the faith community, and others sectors. Community Context We report o...

  19. Remarkable invasion of San Francisco Bay (California, USA), by the Asian clam Potamocorbula amurensis. I. Introduction and dispersal

    Science.gov (United States)

    Carlton, James T.; Thompson, Janet K.; Schemel, Laurence E.; Nichols, Frederic H.

    1990-01-01

    The euryhaline bivalve mollusc Potamocorbula amurensis (family Corbulidae), a native of China, Japan, and Korea, has recently appeared and become very abundant in San Francisco Bay. This clam appears to have been introduced as veliger larvae in the seawater ballast of cargo vessels. It was first collected in northern San Francisco Bay in late 1986. P, amurensis then spread throughout the estuary within 2 yr and reached densities at some sites exceeding 10 000 m-2 It lives primarily in the subtidal on all substrates (mud, sand, peat, and clay) and is found in the full range of bay salinities (estuary ecosystem. These could include changes in (1) trophic dynamics (through competition with other suspension-feeding and deposit-feeding infauna; changes in benthic community energy flow; availability of a new and abundant prey item for birds, fish, and crabs; and reduction - as a result of its filter feeding - of phytoplankton standmg stock) and (2) benthic dynamics (through inhibition and/or enhancement of infauna due to substrate destabilization; alteration of suspended sediment load of near-bottom water; and change of sediment surface redox balance). The early detection of the appearance and spread of P. amurensis in San Francisco Bay makes this one of the best documented invasions of any estuary in the world.

  20. Social marketing campaign significantly associated with increases in syphilis testing among gay and bisexual men in San Francisco.

    Science.gov (United States)

    Montoya, Jorge A; Kent, Charlotte K; Rotblatt, Harlan; McCright, Jacque; Kerndt, Peter R; Klausner, Jeffrey D

    2005-07-01

    Between 1999 and 2002, San Francisco experienced a sharp increase in early syphilis among gay and bisexual men. In response, the San Francisco Department of Public Health launched a social marketing campaign to increase testing for syphilis, and awareness and knowledge about syphilis among gay and bisexual men. A convenience sample of 244 gay and bisexual men (18-60 years of age) were surveyed to evaluate the effectiveness of the campaign. Respondents were interviewed to elicit unaided and aided awareness about the campaign, knowledge about syphilis, recent sexual behaviors, and syphilis testing behavior. After controlling for other potential confounders, unaided campaign awareness was a significant correlate of having a syphilis test in the last 6 months (odds ratio, 3.21; 95% confidence interval, 1.30-7.97) compared with no awareness of the campaign. A comparison of respondents aware of the campaign with those not aware also revealed significant increases in awareness and knowledge about syphilis. The Healthy Penis 2002 campaign achieved its primary objective of increasing syphilis testing, and awareness and knowledge about syphilis among gay and bisexual men in San Francisco.

  1. Drivers of change in estuarine-coastal ecosystems: Discoveries from four decades of study in San Francisco Bay

    Science.gov (United States)

    Cloern, J.E.; Jassby, A.D.

    2012-01-01

    Poised at the interface of rivers, ocean, atmosphere and dense human settlement, estuaries are driven by a large array of natural and anthropogenic forces. San Francisco Bay exemplifies the fast-paced change occurring in many of the world's estuaries, bays and inland seas in response to these diverse forces. We use observations from this particularly well-studied estuary to illustrate responses to six drivers that are common agents of change where land and sea meet: water consumption and diversion; human modification of sediment supply; introduction of non-native species; sewage input; environmental policy; and climate shifts. In San Francisco Bay, responses to these drivers include, respectively, shifts in the timing and extent of freshwater inflow and salinity intrusion; decreasing turbidity; restructuring of plankton communities; nutrient enrichment; elimination of hypoxia and reduced metal contamination of biota; and food web changes that decrease resistance of the estuary to nutrient pollution. Detection of these changes and discovery of their causes through environmental monitoring have been essential for establishing and measuring outcomes of environmental policies that aim to maintain high water quality and sustain services provided by estuarine-coastal ecosystems. The wide range of variability time scales and the multiplicity of interacting drivers place heavy demands on estuarine monitoring programs. But the San Francisco Bay case study illustrates why the imperative for monitoring has never been greater.

  2. Mercury burdens in Chinese mitten crabs (Eriocheir sinensis) in three tributaries of southern San Francisco Bay, California, USA

    Energy Technology Data Exchange (ETDEWEB)

    Hui, Clifford A. [US Geological Survey, 7801 Folsom Blvd, Suite 101, Sacramento, CA 95826 (United States)]. E-mail: bioinvestigations@sbcglobal.net; Rudnick, Deborah [Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720 (United States); Williams, Erin [US Fish and Wildlife Service, 4001 N. Wilson Way, Stockton, CA 95205 (United States)

    2005-02-01

    Chinese mitten crabs (Eriocheir sinensis), endemic to Asia, were first reported in the San Francisco Bay in 1992. They are now established in nearly all San Francisco Bay tributaries. These crabs accumulate more metals, such as mercury, than crustaceans living in the water column. Because their predators include fish, birds, mammals and humans, their mercury burdens have an exceptional potential to impact the ecosystem and public health. We sought to elucidate the potential threat of mitten crab mercury burdens in three adjacent streams in southern San Francisco Bay, one of which is known to be contaminated with mercury. Mitten crabs had hepatopancreas concentrations of total mercury and methylmercury that did not differ among streams. The maximum burden we measured was below the action level of 1 ppm recommended by the USEPA. Hepatopancreas concentrations of methylmercury declined with increasing crab size, suggesting a mechanism for mercury excretion and that predators might reduce mercury exposure if they select larger crabs. Because mercury may be heterogeneously distributed among tissues, estimation of the impacts of crab mercury burdens on the environment requires more data on the feeding preferences of predators. - Hepatopancreas concentrations of mercury decline with crab size, which may have important consequences for bio-magnification in food webs.

  3. Drivers of change in estuarine-coastal ecosystems: Discoveries from four decades of study in San Francisco Bay

    Science.gov (United States)

    Cloern, James E.; Jassby, Alan D.

    2012-12-01

    Poised at the interface of rivers, ocean, atmosphere and dense human settlement, estuaries are driven by a large array of natural and anthropogenic forces. San Francisco Bay exemplifies the fast-paced change occurring in many of the world's estuaries, bays, and inland seas in response to these diverse forces. We use observations from this particularly well-studied estuary to illustrate responses to six drivers that are common agents of change where land and sea meet: water consumption and diversion, human modification of sediment supply, introduction of nonnative species, sewage input, environmental policy, and climate shifts. In San Francisco Bay, responses to these drivers include, respectively, shifts in the timing and extent of freshwater inflow and salinity intrusion, decreasing turbidity, restructuring of plankton communities, nutrient enrichment, elimination of hypoxia and reduced metal contamination of biota, and food web changes that decrease resistance of the estuary to nutrient pollution. Detection of these changes and discovery of their causes through environmental monitoring have been essential for establishing and measuring outcomes of environmental policies that aim to maintain high water quality and sustain services provided by estuarine-coastal ecosystems. The many time scales of variability and the multiplicity of interacting drivers place heavy demands on estuarine monitoring programs, but the San Francisco Bay case study illustrates why the imperative for monitoring has never been greater.

  4. Mercury burdens in Chinese mitten crabs (Eriocheir sinensis) in three tributaries of southern San Francisco Bay, California, USA

    International Nuclear Information System (INIS)

    Hui, Clifford A.; Rudnick, Deborah; Williams, Erin

    2005-01-01

    Chinese mitten crabs (Eriocheir sinensis), endemic to Asia, were first reported in the San Francisco Bay in 1992. They are now established in nearly all San Francisco Bay tributaries. These crabs accumulate more metals, such as mercury, than crustaceans living in the water column. Because their predators include fish, birds, mammals and humans, their mercury burdens have an exceptional potential to impact the ecosystem and public health. We sought to elucidate the potential threat of mitten crab mercury burdens in three adjacent streams in southern San Francisco Bay, one of which is known to be contaminated with mercury. Mitten crabs had hepatopancreas concentrations of total mercury and methylmercury that did not differ among streams. The maximum burden we measured was below the action level of 1 ppm recommended by the USEPA. Hepatopancreas concentrations of methylmercury declined with increasing crab size, suggesting a mechanism for mercury excretion and that predators might reduce mercury exposure if they select larger crabs. Because mercury may be heterogeneously distributed among tissues, estimation of the impacts of crab mercury burdens on the environment requires more data on the feeding preferences of predators. - Hepatopancreas concentrations of mercury decline with crab size, which may have important consequences for bio-magnification in food webs

  5. San Francisco Bay nutrients and plankton dynamics as simulated by a coupled hydrodynamic-ecosystem model

    Science.gov (United States)

    Liu, Qianqian; Chai, Fei; Dugdale, Richard; Chao, Yi; Xue, Huijie; Rao, Shivanesh; Wilkerson, Frances; Farrara, John; Zhang, Hongchun; Wang, Zhengui; Zhang, Yinglong

    2018-06-01

    An open source coupled physical-biogeochemical model is developed for San Francisco Bay (SFB) to study nutrient cycling and plankton dynamics as well as to assist ecosystem based management and risk assessment. The biogeochemical model in this study is based on the Carbon, Silicate and Nitrogen Ecosystem (CoSiNE) model, and coupled to the unstructured grid, Semi-Implicit Cross-scale Hydroscience Integrated System Model (SCHISM). The SCHISM-CoSiNE model reproduces the spatial and temporal variability in nutrients and plankton biomass, and its physical and biogeochemical performance is successfully tested using comparisons with shipboard and fixed station observations. The biogeochemical characteristics of the SFB during wet and dry years are investigated by changing the input of the major rivers. River discharges from the Sacramento and San Joaquin Rivers affect the phytoplankton biomass in North SFB through both advection and dilution of nutrient (including ammonium, NH4) concentrations in the river. The reduction in residence time caused by increased inflows can result in decreased biomass accumulation, while the corresponding reduction in NH4 concentration favors the growth of biomass. In addition, the model is used to make a series of sensitivity experiments to examine the response of SFB to changes in 1) nutrient loading from rivers and wastewater treatment plants (WWTPs), 2) a parameter (ψ) defining NH4 inhibition of nitrate (NO3) uptake by phytoplankton, 3) bottom grazing and 4) suspended sediment concentration. The model results show that changes in NH4 input from rivers or WWTPs affect the likelihood of phytoplankton blooms via NH4 inhibition and that the choice of ψ is critical. Bottom grazing simulated here as increased plankton mortality demonstrates the potential for bivalve reduction of chlorophyll biomass and the need to include bivalve grazing in future models. Furthermore, the model demonstrates the need to include sediments and their contribution

  6. Fine-Scale Distributions of Zooplankton in the Northern San Francisco Estuary

    Directory of Open Access Journals (Sweden)

    Wim Kimmerer

    2016-10-01

    Full Text Available doi: http://dx.doi.org/10.15447/sfews.2016v14iss3art2 We studied zooplankton distributions in the upper San Francisco Estuary at nested scales of tens to thousands of meters. The purposes of the study were to assess how well the Interagency Ecological Program (IEP zooplankton monitoring represents abundance, and to investigate the variability of plankton on scales similar to those of foraging by fish. Samples were taken at three sites in the western Sacramento–San Joaquin Delta. We took 18 sets of six samples each with a plankton net along transects from near shore to center channel, and six sets of ten samples in the vicinity of a drifter either in mid-channel or near shore. Sampling took place in June–July 2014 during neap and spring tides, ebb and flood, day and night (transects only. Analysis focused on three common copepod species. Transect samples showed little consistent variation along transects, except that Pseudodiaptomus forbesi was less abundant nearshore than offshore by day at Big Break, the most landward site. The ratio of adults to adults + copepodites was strongly and positively related to turbidity by day but not by night, indicating demersal behavior. Drifter samples showed a minimum standard deviation of log10 sample counts of about 0.1, indicating that about two-thirds of replicate abundance values were within 80 % to 125% of the mean. A measure of difference between plankton samples at pairs of sample points was unrelated to distance between sample points for drifter samples, weakly related along transects for Limnoithona spp. stages, and strongly related for P. forbesi mainly because of the along-transect gradients at Big Break. The IEP sampling program is representative of plankton abundance except for demersal organisms, which can be ten-fold more abundant by night than by day. Small planktivorous fish could forage in patches of up to ~25% higher abundance than the mean.

  7. Guidelines for sustainable building design: Recommendations from the Presidio of San Francisco energy efficiency design charrette

    Energy Technology Data Exchange (ETDEWEB)

    Brown, K.; Sartor, D.; Greenberg, S. [and others

    1996-05-01

    In 1994, the Bay Chapter of the Association of Energy Engineers{reg_sign} organized a two-day design charrette for energy-efficient redevelopment of buildings by the National Park Services (NPS) at the Presidio of San Francisco. This event brought together engineers, researchers, architects, government officials, and students in a participatory environment to apply their experience to create guidelines for the sustainable redesign of Presidio buildings. The venue for the charrette was a representative barracks building located at the Main Post of the Presidio. Examination of this building allowed for the development of design recommendations, both for the building and for the remainder of the facilities. The charrette was organized into a committee structure consisting of: steering, measurement and monitoring, modeling, building envelope and historic preservation (architectural), HVAC and controls, lighting, and presentation. Prior to the charrette itself, the modeling and measurement/monitoring committees developed substantial baseline data for the other committees during the charrette. An integrated design approach was initiated through interaction between the committees during the charrette. Later, committee reports were cross-referenced to emphasize whole building design and systems integration.

  8. Criminalization, legalization or decriminalization of sex work: what female sex workers say in San Francisco, USA.

    Science.gov (United States)

    Lutnick, Alexandra; Cohan, Deborah

    2009-11-01

    Sex work is a criminal offence in San Francisco, USA, and sex work advocates have so far unsuccessfully campaigned for decriminalizing it. Some groups argue that the decriminalization movement does not represent the voices of marginalized sex workers. Using qualitative and quantitative data from the Sex Worker Environmental Assessment Team Study, we investigated the perspectives and experiences of a range of female sex workers regarding the legal status of sex work and the impact of criminal law on their work experiences. Forty women were enrolled in the qualitative phase in 2004 and 247 women in the quantitative phase in 2006-07. Overall, the women in this study seemed to prefer a hybrid of legalization and decriminalization. The majority voiced a preference for removing statutes that criminalize sex work in order to facilitate a social and political environment where they had legal rights and could seek help when they were victims of violence. Advocacy groups need to explore the compromises sex workers are willing to make to ensure safe working conditions and the same legal protections afforded to other workers, and with those who are most marginalized to better understand their immediate needs and how these can be met through decriminalization.

  9. Changes in causes of death among persons with AIDS: San Francisco, California, 1996-2011.

    Science.gov (United States)

    Schwarcz, Sandra K; Vu, Annie; Hsu, Ling Chin; Hessol, Nancy A

    2014-10-01

    The increased life expectancy among HIV-infected persons treated with combination antiretroviral therapy (ART), risk behaviors, and co-morbidities associated with ART place HIV-infected persons at risk for non-HIV-related causes of death. We used the San Francisco HIV/AIDS registry to identify deaths that occurred from January 1996 through December 2011. Temporal trends in AIDS- and non-AIDS-related mortality rates, the proportion of underlying and contributory causes of death, and the ratio of observed deaths in the study population to expected number of deaths among California men aged 20-79 (standardized mortality ratio [SMR]) of underlying causes of death were examined. A total of 5338 deaths were identified. The annual AIDS-related death rate (per 100 deaths) declined from 10.8 in 1996 to 0.9 in 2011 (pdeath rate from non-AIDS-related causes declined from 2.1 in 1996 to 0.9 in 2011 (pdeaths due to all types of heart disease combined, all non-AIDS cancers combined, mental disorders resulting from substance abuse, drug overdose, suicide and chronic obstructive pulmonary disease increased significantly over time. The SMRs for liver diseased decreased significantly over time but remained elevated. Our data highlight the importance of age-related causes of death as well as deaths from causes that are, at least in part, preventable.

  10. Geophysical Analysis of Young Monogenetic Volcanoes in the San Francisco Volcanic Field, Arizona

    Science.gov (United States)

    Rees, S.; Porter, R. C.; Riggs, N.

    2017-12-01

    The San Francisco Volcanic Field (SFVF), located in northern Arizona, USA, contains some of the youngest intracontinental volcanism within the United States and, given its recent eruptive history, presents an excellent opportunity to better understand how these systems behave. Geophysical techniques such as magnetics, paleomagnetics, and seismic refraction can be used to understand eruptive behavior and image shallow subsurface structures. As such, they present an opportunity to understand eruptive processes associated with the monogenetic volcanism that is common within the SFVF. These techniques are especially beneficial in areas where erosion has not exposed shallow eruptive features within the volcano. We focus on two volcanoes within the SFVF, Merriam Crater and Crater 120 for this work. These are thought to be some of the youngest volcanoes in the field and, as such, are well preserved. Aside from being young, they both exhibit interesting features such as multiple vents, apparent vent alignment, and lack of erosional features that are present at many of the other volcanoes in the SFVF, making them ideal for this work. Initial results show that shallow subsurface basaltic masses can be located using geophysical techniques. These masses are interpreted as dikes or lava flows that are covered by younger scoria. Propagating dikes drive eruptions at monogenetic volcanoes, which often appear in aligned clusters. Locating these features will further the understanding of how magma is transported and how eruptions may have progressed.

  11. Breast cancer characteristics of Vietnamese women in the Greater San Francisco Bay Area.

    Science.gov (United States)

    Lin, Scarlett S; Phan, John C; Lin, Albert Y

    2002-03-01

    To examine breast cancer characteristics of women of Vietnamese ancestry living in the San Francisco Bay Area in comparison with those of other racial or ethnic groups in the same area. Data were obtained from the population-based Greater Bay Area Cancer Registry, part of the Surveillance, Epidemiology, and End Results program. We included breast cancer cases diagnosed from 1988 to 1999 and compared the age at diagnosis, stage and histologic grade at diagnosis, estrogen- and progesterone-receptor status, and surgery types across racial or ethnic groups. We also modeled the effect of patient and clinical characteristics and hospital and physician on the racial or ethnic variations in surgery type. Vietnamese women were younger at diagnosis than other racial or ethnic subgroups (mean age, 51.0 years), with 49.6% of the diagnoses occurring in patients younger than 50. They were also significantly more likely to have received mastectomy for their in situ and localized tumors (61.1% having mastectomy) than women of other racial or ethnic groups. The increased likelihood of having mastectomy among Vietnamese women was not affected greatly by age, year of diagnosis, tumor stage, histologic grade, or physician, but was partly attributable to the hospital of diagnosis. The effects of a lower mean age at diagnosis and the reasons for an unexpectedly higher percentage of mastectomies in this Asian subgroup should be further explored.

  12. Elevational dependence of projected hydrologic changes in the San Francisco Estuary and watershed

    Science.gov (United States)

    Knowles, N.; Cayan, D.R.

    2004-01-01

    California's primary hydrologic system, the San Francisco Estuary and its upstream watershed, is vulnerable to the regional hydrologic consequences of projected global climate change. Previous work has shown that a projected warming would result in a reduction of snowpack storage leading to higher winter and lower spring-summer streamflows and increased spring-summer salinities in the estuary. The present work shows that these hydrologic changes exhibit a strong dependence on elevation, with the greatest loss of snowpack volume in the 1300-2700 m elevation range. Exploiting hydrologic and estuarine modeling capabilities to trace water as it moves through the system reveals that the shift of water in mid-elevations of the Sacramento river basin from snowmelt to rainfall runoff is the dominant cause of projected changes in estuarine inflows and salinity. Additionally, although spring-summer losses of estuarine inflows are balanced by winter gains, the losses have a stronger influence on salinity since longer spring-summer residence times allow the inflow changes to accumulate in the estuary. The changes in inflows sourced in the Sacramento River basin in approximately the 1300-2200 m elevation range thereby lead to a net increase in estuarine salinity under the projected warming. Such changes would impact ecosystems throughout the watershed and threaten to contaminate much of California's freshwater supply.

  13. Predator removal and nesting waterbird success at San Francisco Bay, California

    Science.gov (United States)

    Meckstroth, A.M.; Miles, A.K.

    2005-01-01

    The efficacy of long-term predator removal in urbanized areas is poorly understood. The impact of predation on ground-nesting waterbirds, as well as predator abundance and composition in predator removal versus non-removal or reference sites were examined at South San Francisco Bay. The success of natural nests and predator activity was monitored using track plates, trip cameras, wire haircatchers and simulated nests. Removal sites had higher nest densities, but lower hatching success than reference sites. Predator composition and abundance were not different at the removal and reference sites for any predator other than feral Cat (Felis domesticus). Striped Skunk (Mephitis mephitis) comprised the majority (84%) of predators removed, yet remained the most abundant predators in removal and reference sites. Urban environments provide supplemental food that may influence skunks and other nest predators to immigrate into vacancies created by predator removal. Based on the findings from this study, predator removal should be applied intensively over a larger geographic area in order to be a viable management strategy for some mammalian species in urbanized areas.

  14. Acoustic Doppler velocimeter backscatter for quantification of suspended sediment concentration in South San Francisco Bay, USA

    Science.gov (United States)

    Öztürk, Mehmet; Work, Paul A.

    2016-01-01

    A data set was acquired on a shallow mudflat in south San Francisco Bay that featured simultaneous, co-located optical and acoustic sensors for subsequent estimation of suspended sediment concentrations (SSC). The optical turbidity sensor output was converted to SSC via an empirical relation derived at a nearby site using bottle sample estimates of SSC. The acoustic data was obtained using an acoustic Doppler velocimeter. Backscatter and noise were combined to develop another empirical relation between the optical estimates of SSC and the relative backscatter from the acoustic velocimeter. The optical and acoustic approaches both reproduced similar general trends in the data and have merit. Some seasonal variation in the dataset was evident, with the two methods differing by greater or lesser amounts depending on which portion of the record was examined. It is hypothesized that this is the result of flocculation, affecting the two signals by different degrees, and that the significance or mechanism of the flocculation has some seasonal variability. In the earlier portion of the record (March), there is a clear difference that appears in the acoustic approach between ebb and flood periods, and this is not evident later in the record (May). The acoustic method has promise but it appears that characteristics of flocs that form and break apart may need to be accounted for to improve the power of the method. This may also be true of the optical method: both methods involve assuming that the sediment characteristics (size, size distribution, and shape) are constant.

  15. Leadership lessons from curricular change at the University of California, San Francisco, School of Medicine.

    Science.gov (United States)

    Loeser, Helen; O'Sullivan, Patricia; Irby, David M

    2007-04-01

    After successive Liaison Committee on Medical Education accreditation reports that criticized the University of California, San Francisco, School of Medicine for lack of instructional innovation and curriculum oversight, the dean issued a mandate for curriculum reform in 1997. Could a medical school that prided itself on innovation in research and health care do the same in education? The authors describe their five-phase curriculum change process and correlate this to an eight-step leadership model. The first phase of curricular change is to establish a compelling need for change; it requires leaders to create a sense of urgency and build a guiding coalition to achieve action. The second phase of curriculum reform is to envision a bold new curriculum; leaders must develop such a vision and communicate it broadly. The third phase is to design curriculum and obtain the necessary approvals; this requires leaders to empower broad-based action and generate short-term wins. In the fourth phase, specific courses are developed for the new curriculum, and leaders continue to empower broad-based action, generate short-term wins, consolidate gains, and produce more change. During the fifth phase of implementation and evaluation, leaders need to further consolidate gains, produce more change, and anchor new approaches in the institution. Arising from this experience and the correlation of curricular change phases with leadership steps, the authors identify 27 specific leadership strategies they employed in their curricular reform process.

  16. Primary ciliary dyskinesia: a report from ATS 2001, May 18–23, San Francisco

    Directory of Open Access Journals (Sweden)

    Noone Peadar G

    2001-06-01

    Full Text Available Abstract Primary ciliary dyskinesia (PCD is a genetic disorder of abnormal ciliary structure and function that leads to defective mucociliary clearance, resulting in oto-sino-pulmonary disease, and infertility. The disease is currently under intense investigation by a number of research groups worldwide. At the recent American Thoracic Society meeting in San Francisco in May 2001, two sessions focused on PCD; a symposium session on May 21 with several featured expert speakers was followed by a mini-symposium on Tuesday May 22, with one featured speaker and presentation of nine abstracts covering a range of research topics. Mattias Salathe (University of Miami, USA and Stephen Brody (Washington University, St Louis, USA chaired the symposium session. Presentations focused on the clinical spectrum of PCD, the genetics of PCD, a proteomics approach to detail the structure of cilia, the role of cilia in the embryology of situs laterality, and airway epithelial cell biology. The mini-symposium was chaired by Peadar Noone (University of North Carolina, USA and Malcolm King (University of Alberta, USA and included presentations on the use of PCD as a human disease model, accurate definition of the phenotype using clinical and cell biologic markers, and molecular studies. The latter reports ranged from isolation of a protein involved in ciliary structure and function to genetic studies using linkage analysis and the candidate gene approach. Clinicians and scientists alike displayed considerable interest at both sessions, and there were several lively question–answer sessions.

  17. Breast cancer among American Japanese in the San Francisco Bay area.

    Science.gov (United States)

    Dunn, J E

    1977-12-01

    The Japanese-American population was particularly well suited for the study of cancer occurrence because: 1) An American-born population as well as the immigrant Japanese-American population could be studied; 2) good cancer incidence and mortality data from Japan could be compared with data from the United States; and 3) some differences in the rate of occurrence of several specific cancer sites in Japan as compared with the United States were striking. The most significant of these involved the gastrointestinal tract and sex organs. Data were presented concerning cancer incidence rates for the Japanese-American population of the San Francisco Bay area. The high gastric rates for the Japanese in Japan were reduced in a stepwise fashion in the immigrant Japanese-American population to the American-born Japanese who were approaching the low rate of the United States. Colon cancer rates, which were low in Japan, approached the rates in the United States in both the immigrants from Japan and in Japanese Americans. The low rates of cancers of the breast, uterine corpus, and ovary of Japanese women in Japan and for prostate cancer among men rapidly approached the higher rates for these cancer sites that existed in the United States. A study of nutritional factors related to the increase of cancer of the breast in Japanese Americans is being conducted.

  18. Delta smelt: Life history and decline of a once abundant species in the San Francisco Estuary

    Science.gov (United States)

    Moyle, Peter B.; Brown, Larry R.; Durand, John R; Hobbs, James A.

    2016-01-01

    This paper reviews what has been learned about Delta Smelt and its status since the publication of The State of Bay-Delta Science, 2008 (Healey et al. 2008). The Delta Smelt is endemic to the upper San Francisco Estuary. Much of its historic habitat is no longer available and remaining habitat is increasingly unable to sustain the population. As a listed species living in the central node of California’s water supply system, Delta Smelt has been the focus of a large research effort to understand causes of decline and identify ways to recover the species. Since 2008, a remarkable record of innovative research on Delta Smelt has been achieved, which is summarized here. Unfortunately, research has not prevented the smelt’s continued decline, which is the result of multiple, interacting factors. A major driver of decline is change to the Delta ecosystem from water exports, resulting in reduced outflows and high levels of entrainment in the large pumps of the South Delta. Invasions of alien species, encouraged by environmental change, have also played a contributing role in the decline. Severe drought effects have pushed Delta Smelt to record low levels in 2014–2015. The rapid decline of the species and failure of recovery efforts demonstrate an inability to manage the Delta for the “co-equal goals” of maintaining a healthy ecosystem and providing a reliable water supply for Californians. Diverse and substantial management actions are needed to preserve Delta Smelt.

  19. Survival of postfledging Forster's terns in relation to mercury exposure in San Francisco Bay

    Science.gov (United States)

    Ackerman, Joshua T.; Eagles-Smith, Collin A.; Takekawa, John Y.; Iverson, S.A.

    2008-01-01

    We examined factors influencing mercury concentrations in 90 fledgling Forster's terns (Sterna forsteri) and evaluated whether mercury influenced postfledging survival in San Francisco Bay, California. Mercury concentrations (??SE) in chicks 21-29 days old (just before fledging) were 0.33 ?? 0.01 ??g g-1 ww for blood and 6.44 ?? 0.28 ??g g -1 fw for breast feathers. Colony site had an overriding influence on fledgling contamination, however hatching date and age also affected blood, but not feather, mercury concentrations. Blood mercury concentrations decreased by 28% during the 50-day hatching period and increased with chick age by 30% during the last week prior to fledging. Using radio-telemetry, we calculated that cumulative survival during the 35-day postfledging time period was 0.81 ?? 0.09 (SE). Postfledging survival rates increased with size-adjusted mass, and cumulative survival probability was 61% lower for terns with the lowest, compared to the highest, observed masses. Conversely, survival was not influenced by blood mercury concentration, time since fledging, sex, or hatch date. Mercury concentrations in breast feathers of fledglings found dead at nesting colonies also were no different than those in live chicks. Our results indicate that colony site, hatching date, and age influenced mercury concentrations in fledgling Forster's terns, but that mercury did not influence postfledging survival. ?? 2008 Springer Science+Business Media, LLC.

  20. Bilingual Experience in the Hungarian and German Immigrant Communities of the San Francisco Bay Area

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    Gergely Tóth

    2012-01-01

    Full Text Available Studies on the interaction of languages are gaining importance in today’s world, characterized by accelerated migration and increasing cultural exchange. Unlike most research in this field, which concentrate on one embedded language against a matrix language, this fieldwork-based study examines the linguistic life in two immigrant populations, Hungarian and German, against the background of English. The primary focus of this article is the description of the bilingual and bicultural experience of the two groups. The discussion of language and identity will take a central place in the paper, and diglossia, bilingualism, loyalty, and language as social behavior will also be touched upon (section 4. This is complemented by a socio-historical portrayal of these speech communities of San Francisco, set forth in the preceding section 3. Section 5 provides an outline of the informant sets, spanning three generations in each linguistic cohort, and illustrates the subjects’ attitude towards maintenance. The final, sixth section offers qualitative and quantitative comparative statements about the results of linguistic interference and the ongoing attrition process, thus contributing to our understanding of contact linguistic mechanisms, and shedding light on specific grammatical and lexical features that are most prone to attritional forces.

  1. Predictors of gambling behaviors in Filipino Americans living in Honolulu or San Francisco.

    Science.gov (United States)

    Kim, Wooksoo; Kim, Isok; Nochajski, Thomas H

    2012-06-01

    This study compared the prevalence and predictors of gambling behaviors between Filipino Americans who live in San Francisco (S.F.) or Honolulu. Data from the 1998-1999 Filipino American Community Epidemiological Survey were used to answer two research questions: (1) What are the prevalence and types of gambling behaviors among Filipino Americans and (2) What are the protective/risk factors of heavy gambling for Filipino Americans in S.F. and Honolulu? Overall, S.F. Filipino Americans had a higher level of participation in gambling, and the odds of gambling increased among older age groups, males, those who were US-born, and those with more health problems. Multinomial logistic regression analyses revealed that factors associated with infrequent and regular gambling participation were different between the S.F. group (older, male, higher education) and Honolulu group (male, US-born, more health concerns). Differential gambling environments, i.e., wide open gambling in S.F. and the restrictive gambling in Honolulu, may contribute to gambling participation and predictors of risk gambling Filipino Americans living in Honolulu and S.F. Policy makers and health professionals need to be aware of these differences to serve this population more effectively.

  2. Examining the Effects of Transphobic Discrimination and Race on HIV Risk Among Transwomen in San Francisco.

    Science.gov (United States)

    Arayasirikul, Sean; Wilson, Erin C; Raymond, Henry F

    2017-09-01

    Transwomen, in particular transwomen of color (TWOC), are among the most vulnerable populations at risk for HIV. This secondary analysis is organized using a gender minority stress framework to examine the effects of transphobic discrimination and race on HIV risk factors. We describe the sample of 149 HIV- adult transwomen in San Francisco and use binary logistic regression to examine the relationship between levels of transphobic discrimination and TWOC status on binge drinking and condomless receptive anal intercourse (CRAI), controlling for potential confounders. Those with high levels of transphobic discrimination had 3.59 fold greater odds of engaging in binge drinking compared to those who reported a low level of transphobic discrimination (95% CI 1.284-10.034; P = 0.015). TWOC had nearly threefold greater odds of CRAI compared to white transwomen (95% CI 1.048-8.464; P = 0.040). We discuss implications for gender minority stress research and future interventions for this population.

  3. Bathymetry and digital elevation models of Coyote Creek and Alviso Slough, South San Francisco Bay, California

    Science.gov (United States)

    Foxgrover, Amy C.; Finlayson, David P.; Jaffe, Bruce E.; Fregoso, Theresa A.

    2012-01-05

    In 2010 the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center completed three cruises to map the bathymetry of the main channel and shallow intertidal mudflats in the southernmost part of south San Francisco Bay. The three surveys were merged to generate comprehensive maps of Coyote Creek (from Calaveras Point east to the railroad bridge) and Alviso Slough (from the bay to the town of Alviso) to establish baseline bathymetry prior to the breaching of levees adjacent to Alviso and Guadalupe Sloughs as part of the South Bay Salt Pond Restoration Project (http://www.southbayrestoration.org). Since 2010 the USGS has conducted twelve additional surveys to monitor bathymetric change in this region as restoration progresses.The bathymetry surveys were conducted using the state-of-the-art research vessel R/V Parke Snavely outfitted with an interferometric sidescan sonar for swath mapping in extremely shallow water. This publication provides high-resolution bathymetric data collected by the USGS. For the 2010 baseline survey we have merged the bathymetry with aerial lidar data that were collected for the USGS during the same time period to create a seamless, high-resolution digital elevation model (DEM) of the study area. The series of bathymetry datasets are provided at 1 m resolution and the 2010 bathymetric/topographic DEM at 2 m resolution. The data are formatted as both X, Y, Z text files and ESRI Arc ASCII files that are accompanied by Federal Geographic Data Committee (FGDC) compliant metadata.

  4. HIV Prevalence, Sexual Partners, Sexual Behavior and HIV Acquisition Risk Among Trans Men, San Francisco, 2014.

    Science.gov (United States)

    McFarland, Willi; Wilson, Erin C; Raymond, Henry F

    2017-12-01

    We surveyed 122 trans men using a hybrid sampling method that included randomly selected physical and online venues and peer referral to measure HIV prevalence and risk behaviors. HIV prevalence was 0% (one-sided 97.5% confidence interval 0-3.3%). Of 366 partnerships described, 44.8% were with cisgender women, 23.8% with cisgender men, 20.8% with trans men, and 10.7% with trans women. Condomless receptive anal and front hole/vaginal sex averaged one to three episodes per six months. HIV prevalence in trans men is likely closer to heterosexual cisgender men and women in San Francisco than trans women or MSM. Prevention prioritizing trans women and MSM, coupled with individualized and relevant sexual health education for trans men with partners from these populations, may best address the HIV prevention needs of trans men. Systematic collection of transgender status in Census and health data is needed to understand other health disparities among trans men.

  5. Grazer Functional Roles, Induced Defenses, and Indirect Interactions: Implications for Eelgrass Restoration in San Francisco Bay

    Directory of Open Access Journals (Sweden)

    Jeffrey T. Lewis

    2014-11-01

    Full Text Available Understanding the individual and interactive roles of consumer species is more than academic when the host plant is a subject of intense conservation interest. In a mesocosm experiment, we compared effects of common invertebrate grazers in San Francisco Bay seagrass (Zostera marina, eelgrass beds, finding that some species (a native opisthobranch, Phyllaplysia taylori; a native isopod, Idotea resecata; and an introduced gastropod, Ilyanassa obsoleta enhanced eelgrass growth through removal of epiphytic algae, as is often predicted for small invertebrate grazers on seagrasses, while one (an introduced caprellid amphipod, Caprella cf. drepanochir had neutral effects. In contrast, the putatively-introduced gammaridean amphipod, Ampithoe valida, had strong negative effects on eelgrass (in addition to epiphytes through consumption, as we had previously observed in the field during restoration programs. We tested whether other common grazer species could influence the effects of the eelgrass-grazing Ampithoe, and found that Idotea induced production of phenolic compounds and limited eelgrass damage by Ampithoe, without affecting Ampithoe abundance. These results have implications for restoration strategies, and contribute to a growing awareness of the importance of trait-mediated indirect grazer interactions through grazer-induced changes in plant traits, providing the first example in a seagrass system.

  6. Open Water Processes of the San Francisco Estuary: From Physical Forcing to Biological Responses

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    Wim Kimmerer

    2004-02-01

    Full Text Available This paper reviews the current state of knowledge of the open waters of the San Francisco Estuary. This estuary is well known for the extent to which it has been altered through loss of wetlands, changes in hydrography, and the introduction of chemical and biological contaminants. It is also one of the most studied estuaries in the world, with much of the recent research effort aimed at supporting restoration efforts. In this review I emphasize the conceptual foundations for our current understanding of estuarine dynamics, particularly those aspects relevant to restoration. Several themes run throughout this paper. First is the critical role physical dynamics play in setting the stage for chemical and biological responses. Physical forcing by the tides and by variation in freshwater input combine to control the movement of the salinity field, and to establish stratification, mixing, and dilution patterns throughout the estuary. Many aspects of estuarine dynamics respond to interannual variation in freshwater flow; in particular, abundance of several estuarine-dependent species of fish and shrimp varies positively with flow, although the mechanisms behind these relationships are largely unknown. The second theme is the importance of time scales in determining the degree of interaction between dynamic processes. Physical effects tend to dominate when they operate at shorter time scales than biological processes; when the two time scales are similar, important interactions can arise between physical and biological variability. These interactions can be seen, for example, in the response of phytoplankton blooms, with characteristic time scales of days, to stratification events occurring during neap tides. The third theme is the key role of introduced species in all estuarine habitats; particularly noteworthy are introduced waterweeds and fishes in the tidal freshwater reaches of the estuary, and introduced clams there and in brackish water. The

  7. Noticias de Francisco de Herrera el Viejo en Madrid y del retablo mayor del Colegio de San Basilio, de Sevilla

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    Cornejo, Francisco J.

    2006-12-01

    Full Text Available Documents are presented here attesting to the presence of the painter Francisco de Herrera el Viejo in Madrid between 1647 and 1648. Likewise, important new information concerning the altarpiece of San Basilio in Seville is brought to light: the measurements of the architectural structure, the delay of almost ten years in its installation and payment to the artist; and, above all, the three paintings now located – a Christ Child from the door of the ciborium, and the portraits of Saint Basil the Great and Saint Eumelia, parents of Saint Basil – still attached to a fragment of the original alterpiece.

    En este artículo se dan a conocer documentos que certifican la presencia en Madrid del pintor Francisco de Herrera el Viejo en 1647 y 1648. Además, se aportan importantes novedades acerca del retablo de San Basilio, de Sevilla: las medidas de su arquitectura; el retraso en casi diez años de su instalación y pago al pintor; y, sobre todo, las tres pinturas localizadas - un Niño Jesús, de la puerta del sagrario y los retratos de San Basilio el Mayor y de Santa Eumelia, padres de San Basilio - que continúan insertas en un fragmento del retablo original.

  8. Synthesis of studies in the fall low-salinity zone of the San Francisco Estuary, September-December 2011

    Science.gov (United States)

    Brown, Larry R.; Baxter, Randall; Castillo, Gonzalo; Conrad, Louise; Culberson, Steven; Erickson, Gregg; Feyrer, Frederick; Fong, Stephanie; Gehrts, Karen; Grimaldo, Lenny; Herbold, Bruce; Kirsch, Joseph; Mueller-Solger, Anke; Slater, Steven B.; Sommer, Ted; Souza, Kelly; Van Nieuwenhuyse, Erwin

    2014-01-01

    In fall 2011, a large-scale investigation (fall low-salinity habitat investigation) was implemented by the Bureau of Reclamation in cooperation with the Interagency Ecological Program to explore hypotheses about the ecological role of low-salinity habitat in the San Francisco Estuary—specifically, hypotheses about the importance of fall low-salinity habitat to the biology of delta smelt Hypomesus transpacificus, a species endemic to the San Francisco Estuary and listed as threatened or endangered under federal and state endangered species legislation. The Interagency Ecological Program is a consortium of 10 agencies that work together to develop a better understanding of the ecology of the Estuary and the effects of the State Water Project and Federal Central Valley Project operations on the physical, chemical, and biological conditions of the San Francisco Estuary. The fall low-salinity habitat investigation constitutes one of the actions stipulated in the Reasonable and Prudent Alternative issued with the 2008 Biological Opinion of the U.S. Fish and Wildlife Service, which called for adaptive management of fall Sacramento-San Joaquin Delta outflow following “wet” and “above normal” water years to alleviate jeopardy to delta smelt and adverse modification of delta smelt critical habitat. The basic hypothesis of the adaptive management of fall low-salinity habitat is that greater outflows move the low-salinity zone (salinity 1–6), an important component of delta smelt habitat, westward and that moving the low-salinity zone westward of its position in the fall of recent years will benefit delta smelt, although the specific mechanisms providing such benefit are uncertain. An adaptive management plan was prepared to guide implementation of the adaptive management of fall low-salinity habitat and to reduce uncertainty. This report has three major objectives:

  9. Suspended particulate matter flocculation in a natural tidal wetland located in the San Francisco Estuary

    Science.gov (United States)

    Saraceno, J.; Bergamaschi, B. A.; Wright, S. A.; Boss, E.; Downing, B. D.; Fleck, J.; Ganju, N. K.

    2011-12-01

    flocculation. Additionally, the timing of flocculation was coincident with periods of elevated dissolved organic matter, suggesting organic matter played a role in the formation of large aggregates. Measurements of SPM organic content in ebb water revealed that SPM was enriched in organic matter by up to 50% following interaction with the wetland. Newly formed aggregates were carried out to the estuary with the ebb tide. These results indicate that the Browns Island wetland (and presumably other similar wetlands throughout the San Francisco Bay-Delta) plays an important role in estuarine biogeochemistry and particle cycling because flocculated particles have higher settling velocities and optical properties than their component particles and will behave differently. The implications of these findings are relevant to several tidal wetland management concerns such as the maintenance of marsh elevation, the cycling and transport of contaminants, and water clarity.

  10. Downscaling future climate projections to the watershed scale: A north San Francisco Bay estuary case study

    Science.gov (United States)

    Micheli, Elisabeth; Flint, Lorraine; Flint, Alan; Weiss, Stuart; Kennedy, Morgan

    2012-01-01

    We modeled the hydrology of basins draining into the northern portion of the San Francisco Bay Estuary (North San Pablo Bay) using a regional water balance model (Basin Characterization Model; BCM) to estimate potential effects of climate change at the watershed scale. The BCM calculates water balance components, including runoff, recharge, evapotranspiration, soil moisture, and stream flow, based on climate, topography, soils and underlying geology, and the solar-driven energy balance. We downscaled historical and projected precipitation and air temperature values derived from weather stations and global General Circulation Models (GCMs) to a spatial scale of 270 m. We then used the BCM to estimate hydrologic response to climate change for four scenarios spanning this century (2000–2100). Historical climate patterns show that Marin’s coastal regions are typically on the order of 2 °C cooler and receive five percent more precipitation compared to the inland valleys of Sonoma and Napa because of marine influences and local topography. By the last 30 years of this century, North Bay scenarios project average minimum temperatures to increase by 1.0 °C to 3.1 °C and average maximum temperatures to increase by 2.1 °C to 3.4 °C (in comparison to conditions experienced over the last 30 years, 1981–2010). Precipitation projections for the 21st century vary between GCMs (ranging from 2 to 15% wetter than the 20th-century average). Temperature forcing increases the variability of modeled runoff, recharge, and stream discharge, and shifts hydrologic cycle timing. For both high- and low-rainfall scenarios, by the close of this century warming is projected to amplify late-season climatic water deficit (a measure of drought stress on soils) by 8% to 21%. Hydrologic variability within a single river basin demonstrated at the scale of subwatersheds may prove an important consideration for water managers in the face of climate change. Our results suggest that in arid

  11. Examining and Comparing Earthquake Readiness in East San Francisco Bay Area Communities (Invited)

    Science.gov (United States)

    Ramirez, N.; Bul, V.; Chavez, A.; Chin, W.; Cuff, K. E.; Girton, C.; Haynes, D.; Kelly, G.; Leon, G.; Ramirez, J.; Ramirez, R.; Rodriquez, F.; Ruiz, D.; Torres, J.

    2009-12-01

    Based on past experiences, the potential for casualties and mass destruction that can result from a high magnitude earthquake are well known. Nevertheless, given the East San Francisco Bay Area’s proximity to the Hayward and San Andreas faults, learning about earthquakes and disaster preparedness is of particular importance. While basic educational programs and materials are available both through emergency relief agencies and schools, little research has been done on their effectiveness. Because of the wide socioeconomic spread between communities in the East Bay, we decided to investigate understandings of issues related to disaster and earthquake preparedness among local populations based upon average household income. To accomplish this, we created a survey that was later uploaded to and implemented using Palm Treo Smart Phones. Survey locations were selected in such a way that they reflected the understandings of residents in a diverse set of socio-economic settings. Thus, these locations included a grocery store and nearby plaza in the Fruitvale district of Oakland, CA (zip=94601; median household income= 33,152), as well as the nearby town of Alameda, CA (zip=94502, median household income= 87,855). Preliminary results suggest that in terms of the objective questions on the survey, people from Alameda who participated in our study performed significantly better (difference in percentage correct greater than 10%) than the people from Fruitvale on two of the advanced earthquake knowledge questions. Interestingly enough, people in Fruitvale significantly outperformed people in Alameda on two of the basic earthquake knowledge questions. The final important finding was that while houses in Alameda tended to be newer and more often retrofitted than houses in Fruitvale, the people of the latter location tended to have a higher percentage of respondents claim confidence in the ability of their house to withstand a major earthquake. Based on preliminary results we

  12. Geology and natural history of the San Francisco Bay area: A field-trip guidebook

    Science.gov (United States)

    Stoffer, Philip W.; Gordon, Leslie C.

    2001-01-01

    A National Association of Geoscience Teachers Far Western Section (NAGT-FWS) field conference is an ideal forum for learning about the geology and natural history of the San Francisco Bay area. We visit classic field sites, renew old friendships, and make new ones. This collection of papers includes field guides and road logs for all of the Bay-area trips held during the NAGT-FWS 2001 Fall Field Conference and supplemental chapters on other aspects of the area’s natural and human history. The trips touch on many aspects of the geology and natural hazards of the Bay area, especially urban problems associated with living on an active tectonic plate margin: earthquake faults, coastal erosion, landslides, and the utilization of land and natural resources. We hope this conference not only provides a two-day learning opportunity for conference participants but that students and educators will use this field guidebook for future teaching and research.Many thanks are due to the U.S. Geological Survey (USGS) and San José State University (SJSU) for cohosting the conference. We are grateful to each of the field trip leaders for preparing the trips and writing the accompanying guides. We especially appreciate the many hours put in by the guidebook reviewers, Robert I. Tilling (USGS) and Paula Messina (SJSU), and to the USGS Western Publications Group for editing, layout, and web posting. Additional guidebook contributions include articles by John Galloway, Scott Starratt, Page Mosier, and Susan Toussaint. During the conference guest speakers include Robert I. Tilling (USGS Volcano Hazards Team) and Ross Stein (USGS Earthquake Hazards Team). Workshops prepared for the conference include GIS in the classroom, using USGS data by John Vogel (USGS) and Paula Messina (SJSU), and The Best of BAESI (Bay Area Earth Science Institute), a teacher training organization under the direction of Ellen Metzger (SJSU) and Richard Sedlock (SJSU). The conference provides an opportunity to

  13. Examining social supply among nonmedical prescription stimulant users in the San Francisco Bay Area.

    Science.gov (United States)

    Murphy, Fiona; Murphy, Sheigla; Sales, Paloma; Lau, Nicholas

    2018-04-01

    In the US, prescription stimulants are prescribed for a variety of conditions including attention deficit hyperactivity disorder (ADHD) and narcolepsy. Over the last two decades, dramatic increases in stimulant prescriptions have led to greater availability and increased risk for diversion and nonmedical use. Our own and other investigators' findings indicate that many drug "suppliers" do not fit into the traditional image of drug "dealers." These suppliers typically do not identify themselves as "dealers," but instead understand their drug distribution as sharing with people they know. Coomber and colleagues' (2007; 2013) concept of "social supply" raises the question: When friends supply or facilitate supply of drugs to friends, is this really dealing? Further, if dealing and supplying are distinct kinds of social transactions, should different types of criminal justice approaches be applied? Social supply extends our understanding of drug dealing as a complex social activity. In this article, we examine the issue of social supply among nonmedical users of prescription stimulants. We conducted a 36-month National Institute on Drug Abuse-funded project to conduct a qualitative, mixed methods study of 150 adult nonmedical prescription stimulant users in the San Francisco Bay Area. We explore intersecting factors, including life stage and social location, that contribute to decisions to use prescription stimulants nonmedically, motivations to use, knowledge about risks and benefits of prescription stimulant use, any adverse health or social consequences experienced, availability, acquisition and diversion of prescription stimulants, and differences in attitudes and behaviours. For this analysis, we rely on participants' narratives concerning prescription stimulant acquisition practices and how they understood these interactions, purchases, and exchanges with the suppliers of prescription stimulants in their social networks. The authors argue that acknowledging the

  14. Understanding the Occurrence and Transport of Current-use Pesticides in the San Francisco Estuary Watershed

    Directory of Open Access Journals (Sweden)

    Kathryn Kuivila

    2008-10-01

    Full Text Available The occurrence and potential effects of current-use pesticides are of concern in the San Francisco Estuary watershed but our understanding of the spatial and temporal distribution of contamination is limited. This paper summarizes almost two decades of historical data and uses it to describe our current knowledge of the processes controlling the occurrence of current-use pesticides in the watershed. Monitoring studies analyze fewer than half of the pesticides applied in the watershed and most of our knowledge is about inputs of dissolved pesticides in the upper watershed. The four major seasonal patterns of riverine inputs of pesticides to the estuary can be identified by usage and transport mechanism. Dormant spray insecticides applied to orchards and herbicides applied to a variety of crops are transported by rainfall during the winter. Alfalfa pesticides are detected following rainfall and irrigation return flow in the spring, and rice pesticides are detected following release of rice field water in the summer. Irrigation return flows transport a variety of herbicides during the summer. In addition, pesticides applied on Delta islands can cause elevated pesticide concentrations in localized areas. Although not as well characterized, urban creeks appear to have their own patterns of insecticide concentrations causing toxicity throughout most of the year. Current-use pesticides have also been detected on suspended and bed sediments throughout the watershed but limited data make it difficult to determine occurrence patterns. Data gaps include the lack of analysis of many pesticides (or degradates, changing pesticide use, limited information on pesticide transport within the Delta, and an incomplete understanding of the transport and persistence of sediment-associated pesticides. Future monitoring programs should be designed to address these data gaps.

  15. Mercury dynamics in a San Francisco estuary tidal wetland: assessing dynamics using in situ measurements

    Science.gov (United States)

    Bergamaschi, Brian A.; Fleck, Jacob A.; Downing, Bryan D.; Boss, Emmanuel; Pellerin, Brian A.; Ganju, Neil K.; Schoellhamer, David H.; Byington, Amy A.; Heim, Wesley A.; Stephenson, Mark; Fujii, Roger

    2012-01-01

    We used high-resolution in situ measurements of turbidity and fluorescent dissolved organic matter (FDOM) to quantitatively estimate the tidally driven exchange of mercury (Hg) between the waters of the San Francisco estuary and Browns Island, a tidal wetland. Turbidity and FDOM—representative of particle-associated and filter-passing Hg, respectively—together predicted 94 % of the observed variability in measured total mercury concentration in unfiltered water samples (UTHg) collected during a single tidal cycle in spring, fall, and winter, 2005–2006. Continuous in situ turbidity and FDOM data spanning at least a full spring-neap period were used to generate UTHg concentration time series using this relationship, and then combined with water discharge measurements to calculate Hg fluxes in each season. Wetlands are generally considered to be sinks for sediment and associated mercury. However, during the three periods of monitoring, Browns Island wetland did not appreciably accumulate Hg. Instead, gradual tidally driven export of UTHg from the wetland offset the large episodic on-island fluxes associated with high wind events. Exports were highest during large spring tides, when ebbing waters relatively enriched in FDOM, dissolved organic carbon (DOC), and filter-passing mercury drained from the marsh into the open waters of the estuary. On-island flux of UTHg, which was largely particle-associated, was highest during strong winds coincident with flood tides. Our results demonstrate that processes driving UTHg fluxes in tidal wetlands encompass both the dissolved and particulate phases and multiple timescales, necessitating longer term monitoring to adequately quantify fluxes.

  16. Trace metal associations in the water column of South San Francisco Bay, California

    Science.gov (United States)

    Kuwabara, J.S.; Chang, Cecily C.Y.; Cloern, J.E.; Fries, T.L.; Davis, J.A.; Luoma, S.N.

    1989-01-01

    Spatial distributions of copper (Cu), zinc (Zn) and cadmium (Cd) were followed along a longitudinal gradient of dissolved organic carbon (DOC) in South San Francisco Bay (herein referred to as the South Bay). Dissolved Cu, Zn and Cd concentrations ranged from 24 to 66 nM, from 20 to 107 nM and from 1??2 to 4??7 nM, respectively, in samples collected on five dates beginning with the spring phytoplankton bloom and continuing through summer,1985. Dissolved Cu and Zn concentrations varied indirectly with salinity and directly with DOC concentration which ranged from 2??1 to 4??1 mg l-1. Available thermodynamic data strongly support the hypothesis that Cu speciation may be dominated by association with dissolved organic matter. Analogous control of Zn speciation by organic complexation was, however, not indicated in our computations. Computed free ion activity estimates for Cu, Zn and Cd were of the order of 10-10, 10-8 and 10-10 M, respectively. The availability of these metals may be among the factors regulating the growth of certain phytoplankton species within this region of the estuary. In contrast to dissolved Cu, dissolved Cd was directly related to the concentration of suspended particulate matter, suggesting a source of dissolved Cd coincident with elevated particle concentrations in the South Bay (e.g. runoff and solute desorption). Consistent with work in other estuaries, partitioning of all three trace metals onto suspended particulates was negatively correlated with salinity and positively correlated with increases in particulate organic carbon associated with the phytoplankton bloom. These results for the South Bay indicate that sorption processes influence dissolved concentrations of these trace metals, the degree of this influence varies among metals, and processes controlling metal distribution in this estuary appear to be more element-specific than spatially- or temporally-specific. ?? 1989.

  17. Estimates of bottom roughness length and bottom shear stress in South San Francisco Bay, California

    Science.gov (United States)

    Cheng, R.T.; Ling, C.-H.; Gartner, J.W.; Wang, P.-F.

    1999-01-01

    A field investigation of the hydrodynamics and the resuspension and transport of participate matter in a bottom boundary layer was carried out in South San Francisco Bay (South Bay), California, during March-April 1995. Using broadband acoustic Doppler current profilers, detailed measurements of turbulent mean velocity distribution within 1.5 m above bed have been obtained. A global method of data analysis was used for estimating bottom roughness length zo and bottom shear stress (or friction velocities u*). Field data have been examined by dividing the time series of velocity profiles into 24-hour periods and independently analyzing the velocity profile time series by flooding and ebbing periods. The global method of solution gives consistent properties of bottom roughness length zo and bottom shear stress values (or friction velocities u*) in South Bay. Estimated mean values of zo and u* for flooding and ebbing cycles are different. The differences in mean zo and u* are shown to be caused by tidal current flood-ebb inequality, rather than the flooding or ebbing of tidal currents. The bed shear stress correlates well with a reference velocity; the slope of the correlation defines a drag coefficient. Forty-three days of field data in South Bay show two regimes of zo (and drag coefficient) as a function of a reference velocity. When the mean velocity is >25-30 cm s-1, the ln zo (and thus the drag coefficient) is inversely proportional to the reference velocity. The cause for the reduction of roughness length is hypothesized as sediment erosion due to intensifying tidal currents thereby reducing bed roughness. When the mean velocity is <25-30 cm s-1, the correlation between zo and the reference velocity is less clear. A plausible explanation of scattered values of zo under this condition may be sediment deposition. Measured sediment data were inadequate to support this hypothesis, but the proposed hypothesis warrants further field investigation.

  18. Acquired Color Vision Defects and Hexane Exposure: A Study of San Francisco Bay Area Automotive Mechanics.

    Science.gov (United States)

    Beckman, Stella; Eisen, Ellen A; Bates, Michael N; Liu, Sa; Haegerstrom-Portnoy, Gunilla; Hammond, S Katharine

    2016-06-01

    Occupational exposure to solvents, including n-hexane, has been associated with acquired color vision defects. Blue-yellow defects are most common and may be due to neurotoxicity or retinal damage. Acetone may potentiate the neurotoxicity of n-hexane. We present results on nonhexane solvent and hexane exposure and color vision from a cross-sectional study of 835 automotive repair workers in the San Francisco Bay Area, California (2007-2013). Cumulative exposure was estimated from self-reported work history, and color vision was assessed using the Lanthony desaturated D-15 panel test. Log-binomial regression was used to estimate prevalence ratios for color vision defects. Acquired color vision defects were present in 29% of participants, of which 70% were blue-yellow. Elevated prevalence ratios were found for nonhexane solvent exposure, with a maximum of 1.31 (95% confidence interval (CI): 0.86, 2.00) for blue-yellow. Among participants aged ≤50 years, the prevalence ratio for blue-yellow defects was 2.17 (95% CI: 1.03, 4.56) in the highest quartile of nonhexane solvent exposure and 1.62 (95% CI: 0.97, 2.72) in the highest category of exposure to hexane with acetone coexposure. Cumulative exposures to hexane and nonhexane solvents in the highest exposure categories were associated with elevated prevalence ratios for color vision defects in younger participants. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Waterbird egg mercury concentrations in response to wetland restoration in south San Francisco Bay, California

    Science.gov (United States)

    Ackerman, Joshua T.; Herzog, Mark P.; Hartman, Christopher A.; Watts, Trevor C.; Barr, Jarred R.

    2014-01-01

    The conversion of 50–90 percent of 15,100 acres of former salt evaporation ponds to tidal marsh habitat in the south San Francisco Bay, California, is planned as part of the South Bay Salt Pond Restoration Project. This large-scale habitat restoration may change the bioavailability of methylmercury. The South Bay already is known to have high methylmercury concentrations, with methylmercury concentrations in several waterbirds species more than known toxicity thresholds where avian reproduction is impaired. In this 2013 study, we continued monitoring bird egg mercury concentrations in response to the restoration of the Pond A8/A7/A5 Complex to a potential tidal marsh in the future. The restoration of the Pond A8/A7/A5 Complex began in autumn 2010, and the Pond A8 Notch was opened 5 feet (one of eight gates) to muted tidal action on June 1, 2011, and then closed in the winter. In autumn 2010, internal levees between Ponds A8, A7, and A5 were breached and water depths were substantially increased by flooding the Pond A8/A7/A5 Complex in February 2011. In June 2012, 15 feet (three of eight gates) of the Pond A8 Notch was opened, and then closed in December 2012. In June 2013, 15 feet of the Pond A8 Notch again was opened, and the Pond A8/A7/A5 Complex was a relatively deep and large pond with muted tidal action in the summer. This report synthesizes waterbird data from the 2013 breeding season, and combines it with our prior study’s data from 2010 and 2011.

  20. A stratigraphic model to support remediation of groundwater contamination in the southern San Francisco Bay area

    International Nuclear Information System (INIS)

    Steinpress, M.G.

    1993-01-01

    Some early regional studies in the southern San Francisco Bay Area applied the term 'older bay mud' to Wisconsin and older deposits thought to be estuarine in origin. This outdated interpretation has apparently contributed to an expectation of laterally-continuous aquifers and aquitards. In fact, heterogeneous alluvial deposits often create complex hydrogeologic settings that defy simple remedial approaches. A more useful stratigraphic model provides a foundation for conducting site investigations and assessing the feasibility of remediation. A synthesis of recent regional studies and drilling results at one site on the southwest margin of the Bay indicate that the upper quaternary stratigraphy consists of four primary units in the upper 200 feet of sediments (oldest to youngest): (1) Illinoian glacial-age alluvium (an important groundwater source); (2) Sangamon interglacial-age deposits, which include fine-grained alluvial deposits and estuarine deposits equivalent to the Yerba Buena Mud (a regional confining layer); (3) Wisconsin glacial-age alluvial fan and floodplain deposits; and (4) Holocene interglacial-age sediments, which include fine-grained alluvial and estuarine deposits equivalent to the 'younger bay mud'. Remedial investigations generally focus on groundwater contamination in the Wisconsin and Holocene alluvial deposits. Detailed drilling results indicate that narrow sand and gravel channels occur in anastomosing patterns within a Wisconsin to Holocene floodplain sequence dominated by interchannel silts and clays. The identification of these small-scale high-permeability conduits is critical to understanding and predicting contaminant transport on a local scale. Discontinuous site-specific aquitards do not provide competent separation where stacked channels occur and the correlation of aquitards over even small distance is often tenuous at best

  1. Remotely Sensing Pollution: Detection and Monitoring of PCBs in the San Francisco Bay

    Science.gov (United States)

    Hilton, A.; Kudela, R. M.; Bausell, J.

    2016-12-01

    While the EPA banned polychlorinated biphenyls (PCBs) in 1977, they continue to persist in San Francisco Bay (SF Bay), often at dangerously high concentrations due to their long half-life. However, in spite of their associated health and environmental risks, PCB monitoring within SF Bay is extremely limited, due in large part to the high costs, both in terms of labor and capital that are associated with it. In this study, a cost effective alternative to in-situ PCB sampling is presented by demonstrating the feasibility of PCB detection via remote sensing. This was done by first establishing relationships between in-situ measurements of sum of 40 PCB concentrations and total suspended sediment concentration (SSC) collected from 1998-2006 at 37 stations distributed throughout SF Bay. A correlation was discovered for all stations at (R2 =0.32), which improved markedly upon partitioning stations into north bay, (R2 =0.64), central bay (R2 =0.80) and south bay (R2 =0.52) regions. SSC was then compared from three USGS monitoring stations with temporally consistent Landsat 8 imagery. The resulting correlation between Landsat 8 (Rrs 654) and SSC measured at USGS stations (R2 =0.50) was validated using an Airborne Visible/ Infrared Imaging Spectrometer (AVIRIS) image. The end product is a two-step empirical algorithm that can derive PCB from Landsat 8 imagery within SF Bay. This algorithm can generate spatial PCB concentration maps for SF Bay, which can in turn be utilized to increase ability to forecast PCB concentration. The observation that correlation between AVIRIS (Rrs 657) and SSC was stronger than that of Landsat 8 suggests that the accuracy of this algorithm could be enhanced with improved atmospheric correction.

  2. Suspended-sediment dynamics in the tidal reach of a San Francisco Bay tributary

    Science.gov (United States)

    Shellenbarger, Gregory; Downing-Kunz, Maureen; Schoellhamer, David H.

    2015-01-01

    To better understand suspended-sediment transport in a tidal slough adjacent to a large wetland restoration project, we deployed continuously measuring temperature, salinity, depth, turbidity, and velocity sensors in 2010 at a near-bottom location in Alviso Slough (Alviso, California, USA). Alviso Slough is the downstream reach of the Guadalupe River and flows into the far southern end of San Francisco Bay. River flow is influenced by the Mediterranean climate, with high flows (∼90 m3 s−1) correlated to episodic winter storms and low base flow (∼0.85 m3 s−1) during the summer. Storms and associated runoff have a large influence on sediment flux for brief periods, but the annual peak sediment concentrations in the slough, which occur in April and May, are similar to the rest of this part of the bay and are not directly related to peak discharge events. Strong spring tides promote a large upstream sediment flux as a front associated with the passage of a salt wedge during flood tide. Neap tides do not have flood-directed fronts, but a front seen sometimes during ebb tide appears to be associated with the breakdown of stratification in the slough. During neap tides, stratification likely suppresses sediment transport during weaker flood and ebb tides. The slough is flood dominant during spring tides, and ebb dominant during neap tides. Extreme events in landward (salt wedge) and bayward (rainfall events) suspended-sediment flux account for 5.0 % of the total sediment flux in the slough and only 0.55 % of the samples. The remaining 95 % of the total sediment flux is due to tidal transport, with an imbalance in the daily tidal transport producing net landward flux. Overall, net sediment transport during this study was landward indicating that sediment in the sloughs may not be flushed to the bay and are available for sedimentation in the adjacent marshes and ponds.

  3. Ground-motion modeling of the 1906 San Francisco earthquake, part I: Validation using the 1989 Loma Prieta earthquake

    Science.gov (United States)

    Aagaard, Brad T.; Brocher, T.M.; Dolenc, D.; Dreger, D.; Graves, R.W.; Harmsen, S.; Hartzell, S.; Larsen, S.; Zoback, M.L.

    2008-01-01

    We compute ground motions for the Beroza (1991) and Wald et al. (1991) source models of the 1989 magnitude 6.9 Loma Prieta earthquake using four different wave-propagation codes and recently developed 3D geologic and seismic velocity models. In preparation for modeling the 1906 San Francisco earthquake, we use this well-recorded earthquake to characterize how well our ground-motion simulations reproduce the observed shaking intensities and amplitude and durations of recorded motions throughout the San Francisco Bay Area. All of the simulations generate ground motions consistent with the large-scale spatial variations in shaking associated with rupture directivity and the geologic structure. We attribute the small variations among the synthetics to the minimum shear-wave speed permitted in the simulations and how they accommodate topography. Our long-period simulations, on average, under predict shaking intensities by about one-half modified Mercalli intensity (MMI) units (25%-35% in peak velocity), while our broadband simulations, on average, under predict the shaking intensities by one-fourth MMI units (16% in peak velocity). Discrepancies with observations arise due to errors in the source models and geologic structure. The consistency in the synthetic waveforms across the wave-propagation codes for a given source model suggests the uncertainty in the source parameters tends to exceed the uncertainty in the seismic velocity structure. In agreement with earlier studies, we find that a source model with slip more evenly distributed northwest and southeast of the hypocenter would be preferable to both the Beroza and Wald source models. Although the new 3D seismic velocity model improves upon previous velocity models, we identify two areas needing improvement. Nevertheless, we find that the seismic velocity model and the wave-propagation codes are suitable for modeling the 1906 earthquake and scenario events in the San Francisco Bay Area.

  4. Iglesia y participación comunitaria en salud: el caso del Municipio San Francisco del estado Zulia, Venezuela

    OpenAIRE

    José Guillermo García

    2002-01-01

    Este trabajo tiene por objeto identificar en forma comparada los factores que condicionan la participación de las comunidades Betulio González y 24 de Julio del municipio San Francisco del estado Zulia en el subprograma de Medicina Natural que promociona la Iglesia Católica. Bajo un esquema conceptual que combina principios de las teorías: Elección Racional, Movilización de Recursos, Privación Relativa, Identidades Colectivas y Capital Social, se plantea la hipótesis que la par...

  5. Geographies of displacement: Latina/os, oral history, and the politics of gentrification in San Francisco's Mission District.

    Science.gov (United States)

    Mirabal, Nancy Raquel

    2009-05-01

    During the 1990s and early 2000s, working-class and poor neighborhoods in San Francisco underwent dramatic economic and racial changes. One of the most heavily gentrified neighborhoods was the Mission District. As a result of local politics, housing and rental policies, real estate speculation, and development, thousands of Latina/o families were displaced. Using oral historical and ethnographic methodologies, print media, archival sources, and policy papers, this article traces the gentrification of the Mission District from the perspective of the Latina/o community. It also examines how gentrification was articulated as a positive turn within the larger public discourse on space and access.

  6. Transformaciones del modelo Neogranadino de parroquialización. El caso de la Parroquia San Francisco Xavier de Piedecuesta

    Directory of Open Access Journals (Sweden)

    Luis Rubén Pérez Pinzón

    2013-01-01

    Full Text Available El artículo analiza los fundamentos canónigos, las razones virreinales y los rituales eclesiásticos que justificaron las fundaciones parroquiales del siglo XVIII. Para ello se enfatiza en el modelo de urbanismo de las autoridades borbónicas que sustituyó la práctica de fundaciones de ciudades y villas de los siglos XVI y XVII a partir de capitulaciones. Modelo de necesidades demostradas, visitas a las instituciones virreinales y verificación de méritos que se puede comprobar desde el caso de la parroquia moderna de San Francisco Xavier del Pie de la Cuesta (Santander, Colombia, la cual pasó de ser un sitio irregular a la próspera Villa de San Carlos del siglo XIX.

  7. Use of geochemical biomarkers in bottom sediment to track oil from a spill, San Francisco Bay, California

    Science.gov (United States)

    Hostettler, F.D.; Rapp, J.B.; Kvenvolden, K.A.

    1992-01-01

    In April 1988, approximately 1500 m3 of a San Joaquin Valley crude oil were accidentally released from a Shell Oil Co. refinery near Martinez, Californa. The oil flowed into Carquinez Strait and Suisun Bay in northern San Francisco Bay Sediment and oil samples were collected within a week and analysed for geochemical marker compounds in order to track the molecular signature of the oil spill in the bottom sediment. Identification of the spilled oil in the sediment was complicated by the degraded nature of the oil and the similarity of the remaining, chromatographically resolvable constituents to those already present in the sediments from anthropogenic petroleum contamination, pyrogenic sources, and urban drainage. Ratios of hopane and sterane biomarkers, and of polycyclic aromatic hydrocarbons and their alkylated derivatives best identified the oil impingement. They showed the oil impact at this early stage to be surficial only, and to be patchy even within an area of heavy oil exposure.

  8. Data from theodolite measurements of creep rates on San Francisco Bay region faults, California, 1979-2012

    Science.gov (United States)

    McFarland, Forrest S.; Lienkaemper, James J.; Caskey, S. John

    2009-01-01

    Our purpose is to annually update our creep-data archive on San Francisco Bay region active faults for use by the scientific research community. Earlier data (1979-2001) were reported in Galehouse (2002) and were analyzed and described in detail in a summary report (Galehouse and Lienkaemper, 2003). A complete analysis of our earlier results obtained on the Hayward Fault was presented in Lienkaemper, Galehouse and Simpson (2001) and updated in Lienkaemper and others (2012). Lienkaemper and others (2014a) provide a new overview and analysis of fault creep along all sections of the northern San Andreas Fault system, from which they estimate by how much fault creep reduces the seismic hazard for each fault section.

  9. Insights into microbial communities involved in mercury methylation in the San Francisco Bay estuary

    Science.gov (United States)

    Machak, C.; Francis, C. A.

    2013-12-01

    San Francisco Bay (SFB) estuary is the largest estuary on the western coast of the United States, draining a watershed covering more than one third of the state of California. Mercury (Hg) contamination in SFB, as a result of gold and mercury mining in the Coast Range and Sierra Nevada region, has been observed for at least 150 years. Additional sources of Hg contamination to SFB come from active oil refineries, manufacturing, and wastewater treatment plants in the area. Concentrations of methylmercury in the sediment at the time of sample collection for the present study ranged from 0.011-3.88 μg/kg (dry weight). At some sites, the concentration exceeds wetland toxicity limits, posing a threat to the health of the ecosystem and potentially endangering humans that use the estuary for food and recreation. This study attempts to understand the factors that control the transformation of Hg to methylmercury by microorganisms in aquatic sediments, where the majority of Hg methylation is known to occur. Under anoxic conditions, some sulfate- and iron-reducing bacteria have the capacity to transform Hg into methylmercury. To better understand the microbial communities involved in Hg methylation, an extensive library of 16S rRNA sequences was generated (via Illumina sequencing) from sediment samples at 20 sites throughout the SFB estuary. In addition to genomic data, we have access to a massive database of geochemical measurements made by the SFB Regional Monitoring Program at the sampling locations. These measurements show that our sediment samples have varying methylmercury concentrations and span gradients in porewater sulfate and Fe(III), which are the two known alternative electron acceptors for mercury-methylating anaerobic bacteria. The sampling sites also span gradients in other geochemical factors known to influence microbial community composition (and potentially Hg mercury methylation), such as available organic carbon, pH, and salinity. We will present the

  10. A sediment budget for the southern reach in San Francisco Bay, CA: Implications for habitat restoration

    Science.gov (United States)

    Shellenbarger, Gregory; Wright, Scott A.; Schoellhamer, David H.

    2013-01-01

    The South Bay Salt Pond Restoration Project is overseeing the restoration of about 6000 ha of former commercial salt-evaporation ponds to tidal marsh and managed wetlands in the southern reach of San Francisco Bay (SFB). As a result of regional groundwater overdrafts prior to the 1970s, parts of the project area have subsided below sea-level and will require between 29 and 45 million m3 of sediment to raise the surface of the subsided areas to elevations appropriate for tidal marsh colonization and development. Therefore, a sufficient sediment supply to the far south SFB subembayment is a critical variable for achieving restoration goals. Although both major tributaries to far south SFB have been seasonally gaged for sediment since 2004, the sediment flux at the Dumbarton Narrows, the bayward boundary of far south SFB, has not been quantified until recently. Using daily suspended-sediment flux data from the gages on Guadalupe River and Coyote Creek, combined with continuous suspended-sediment flux data at Dumbarton Narrows, we computed a sediment budget for far south SFB during Water Years 2009–2011. A Monte Carlo approach was used to quantify the uncertainty of the flux estimates. The sediment flux past Dumbarton Narrows from the north dominates the input to the subembayment. However, environmental conditions in the spring can dramatically influence the direction of springtime flux, which appears to be a dominant influence on the net annual flux. It is estimated that up to several millennia may be required for natural tributary sediments to fill the accommodation space of the subsided former salt ponds, whereas supply from the rest of the bay could fill the space in several centuries. Uncertainty in the measurement of sediment flux is large, in part because small suspended-sediment concentration differences between flood and ebb tides can lead to large differences in total mass exchange. Using Monte Carlo simulations to estimate the random error associated with

  11. The HayWired Scenario - How Can the San Francisco Bay Region Bounce Back Better?

    Science.gov (United States)

    Hudnut, K. W.; Wein, A. M.; Cox, D. A.; Perry, S. C.; Porter, K.; Johnson, L. A.; Strauss, J. A.

    2017-12-01

    The HayWired scenario is a hypothetical yet scientifically realistic and quantitative depiction of a moment magnitude (Mw) 7.0 earthquake occurring on April 18, 2018, at 4:18 p.m. on the Hayward Fault in the east bay part of the San Francisco Bay area, California. The hypothetical earthquake has its epicenter in Oakland, and strong ground shaking from the scenario causes a wide range of severe impacts throughout the greater bay region. In the scenario, the Hayward Fault is ruptured along its length for 83 kilometers (about 52 miles). Building on a decades-long series of efforts to reduce earthquake risk in the SF Bay area, the hypothetical HayWired earthquake is used to examine the well-known earthquake hazard of the Hayward Fault, with a focus on newly emerging vulnerabilities. After a major earthquake disaster, reestablishing water services and food-supply chains are, of course, top priorities. However, problems associated with telecommunication outages or "network congestion" will increase and become more urgent as the bay region deepens its reliance on the "Internet of Things." Communications at all levels are crucial during incident response following an earthquake. Damage to critical facilities (such as power plants) from earthquake shaking and to electrical and telecommunications wires and fiber-optic cables that are severed where they cross a fault rupture can trigger cascading Internet and telecommunications outages, and restoring these services is crucially important for emergency-response coordination. Without good communications, emergency-response efficiency is reduced, and as a result, life-saving response functions can be compromised. For these reasons, the name HayWired was chosen for this scenario to emphasize the need to examine our interconnectedness and reliance on telecommunications and other lifelines (such as water and electricity). Earthquake risk in the SF Bay area has been greatly reduced as a result of previous concerted efforts; for

  12. Airborne Quantification of Methane Emissions in the San Francisco Bay Area of California

    Science.gov (United States)

    Guha, A.; Newman, S.; Martien, P. T.; Young, A.; Hilken, H.; Faloona, I. C.; Conley, S.

    2017-12-01

    The Bay Area Air Quality Management District, the San Francisco Bay Area's air quality regulatory agency, has set a goal to reduce the region's greenhouse gas (GHG) emissions 80% below 1990 levels by 2050, consistent with the State of California's climate protection goal. The Air District maintains a regional GHG emissions inventory that includes emissions estimates and projections which influence the agency's programs and regulatory activities. The Air District is currently working to better characterize methane emissions in the GHG inventory through source-specific measurements, to resolve differences between top-down regional estimates (Fairley and Fischer, 2015; Jeong et al., 2016) and the bottom-up inventory. The Air District funded and participated in a study in Fall 2016 to quantify methane emissions from a variety of sources from an instrumented Mooney aircraft. This study included 40 hours of cylindrical vertical profile flights that combined methane and wind measurements to derive mass emission rates. Simultaneous measurements of ethane provided source-apportionment between fossil-based and biological methane sources. The facilities sampled included all five refineries in the region, five landfills, two dairy farms and three wastewater treatment plants. The calculated mass emission rates were compared to bottom-up rates generated by the Air District and to those from facility reports to the US EPA as part of the mandatory GHG reporting program. Carbon dioxide emission rates from refineries are found to be similar to bottom-up estimates for all sources, supporting the efficacy of the airborne measurement methodology. However, methane emission estimates from the airborne method showed significant differences for some source categories. For example, methane emission estimates based on airborne measurements were up to an order of magnitude higher for refineries, and up to five times higher for landfills compared to bottom-up methods, suggesting significant

  13. The critical role of islands for waterbird breeding and foraging habitat in managed ponds of the South Bay Salt Pond Restoration Project, South San Francisco Bay, California

    Science.gov (United States)

    Ackerman, Joshua T.; Hartman, C. Alex; Herzog, Mark P.; Smith, Lacy M.; Moskal, Stacy M.; De La Cruz, Susan E. W.; Yee, Julie L.; Takekawa, John Y.

    2014-01-01

    The South Bay Salt Pond Restoration Project aims to restore 50–90 percent of former salt evaporation ponds into tidal marsh in South San Francisco Bay, California. However, large numbers of waterbirds use these ponds annually as nesting and foraging habitat. Islands within ponds are particularly important habitat for nesting, foraging, and roosting waterbirds. To maintain current waterbird populations, the South Bay Salt Pond Restoration Project plans to create new islands within former salt ponds in South San Francisco Bay. In a series of studies, we investigated pond and individual island attributes that are most beneficial to nesting, foraging, and roosting waterbirds.

  14. The significance of ultra-refracted surface gravity waves on sheltered coasts, with application to San Francisco Bay

    Science.gov (United States)

    Hanes, D.M.; Erikson, L.H.

    2013-01-01

    Ocean surface gravity waves propagating over shallow bathymetry undergo spatial modification of propagation direction and energy density, commonly due to refraction and shoaling. If the bathymetric variations are significant the waves can undergo changes in their direction of propagation (relative to deepwater) greater than 90° over relatively short spatial scales. We refer to this phenomenon as ultra-refraction. Ultra-refracted swell waves can have a powerful influence on coastal areas that otherwise appear to be sheltered from ocean waves. Through a numerical modeling investigation it is shown that San Francisco Bay, one of the earth's largest and most protected natural harbors, is vulnerable to ultra-refracted ocean waves, particularly southwest incident swell. The flux of wave energy into San Francisco Bay results from wave transformation due to the bathymetry and orientation of the large ebb tidal delta, and deep, narrow channel through the Golden Gate. For example, ultra-refracted swell waves play a critical role in the intermittent closure of the entrance to Crissy Field Marsh, a small restored tidal wetland located on the sheltered north-facing coast approximately 1.5 km east of the Golden Gate Bridge.

  15. Six-year mortality in a street-recruited cohort of homeless youth in San Francisco, California.

    Science.gov (United States)

    Auerswald, Colette L; Lin, Jessica S; Parriott, Andrea

    2016-01-01

    Objectives. The mortality rate of a street-recruited homeless youth cohort in the United States has not yet been reported. We examined the six-year mortality rate for a cohort of street youth recruited from San Francisco street venues in 2004. Methods. Using data collected from a longitudinal, venue-based sample of street youth 15-24 years of age, we calculated age, race, and gender-adjusted mortality rates. Results. Of a sample of 218 participants, 11 died from enrollment in 2004 to December 31, 2010. The majority of deaths were due to suicide and/or substance abuse. The death rate was 9.6 deaths per hundred thousand person-years. The age, race and gender-adjusted standardized mortality ratio was 10.6 (95% CI [5.3-18.9]). Gender specific SMRs were 16.1 (95% CI [3.3-47.1]) for females and 9.4 (95% CI [4.0-18.4]) for males. Conclusions. Street-recruited homeless youth in San Francisco experience a mortality rate in excess of ten times that of the state's general youth population. Services and programs, particularly housing, mental health and substance abuse interventions, are urgently needed to prevent premature mortality in this vulnerable population.

  16. The integration of engineering and architecture: A perspective on natural ventilation for the new San Francisco Federal Building

    International Nuclear Information System (INIS)

    McConahey, Erin; Haves, Philip; Christ, Tim

    2002-01-01

    A description of the in-progress design of a new Federal Office Building for San Francisco is used to illustrate a number of issues arising in the design of large, naturally ventilated office buildings. These issues include the need for an integrated approach to design involving the architects, mechanical and structural engineers, lighting designers and specialist simulation modelers. In particular, the use of natural ventilation, and the avoidance of air-conditioning, depends on the high degree of exposed thermal mass made possible by the structural scheme and by the minimization of solar heat gains while maintaining the good daylighting that results from optimization of the facade. Another issue was the need for a radical change in interior space planning in order to enhance the natural ventilation; all the individual enclosed offices are located along the central spine of each floorplate rather than at the perimeter. The role of integration in deterring the undermining of the design through value engineering is discussed. The comfort criteria for the building were established based on the recent extension to the ASHRAE comfort standard based on the adaptive model for naturally ventilated buildings. The building energy simulation program EnergyPlus was used to compare the performance of different natural ventilation strategies. The results indicate that, in the San Francisco climate, wind-driven ventilation provides sufficient nocturnal cooling to maintain comfortable conditions and that external chimneys do not provide significant additional ventilation at times when it when it would be beneficial

  17. Trophic structure and avian communities across a salinity gradient in evaporation ponds of the San Francisco Bay estuary

    Science.gov (United States)

    Takekawa, John Y.; Miles, A.K.; Schoellhamer, D.H.; Athearn, N.D.; Saiki, M.K.; Duffy, W.D.; Kleinschmidt, S.; Shellenbarger, G.G.; Jannusch, C.A.

    2006-01-01

    Commercial salt evaporation ponds comprise a large proportion of baylands adjacent to the San Francisco Bay, a highly urbanized estuary. In the past two centuries, more than 79% of the historic tidal wetlands in this estuary have been lost. Resource management agencies have acquired more than 10 000 ha of commercial salt ponds with plans to undertake one of the largest wetland restoration projects in North America. However, these plans have created debate about the ecological importance of salt ponds for migratory bird communities in western North America. Salt ponds are unique mesohaline (5–18 g l−1) to hyperhaline (> 40 g l−1) wetlands, but little is known of their ecological structure or value. Thus, we studied decommissioned salt ponds in the North Bay of the San Francisco Bay estuary from January 1999 through November 2001. We measured water quality parameters (salinity, DO, pH, temperature), nutrient concentrations, primary productivity, zooplankton, macroinvertebrates, fish, and birds across a range of salinities from 24 to 264 g l−1. Our studies documented how unique limnological characteristics of salt ponds were related to nutrient levels, primary productivity rates, invertebrate biomass and taxa richness, prey fish, and avian predator numbers. Salt ponds were shown to have unique trophic and physical attributes that supported large numbers of migratory birds. Therefore, managers should carefully weigh the benefits of increasing habitat for native tidal marsh species with the costs of losing these unique hypersaline systems.

  18. Avian response to early tidal salt marsh restoration at former commercial salt evaporation ponds in San Francisco Bay, California, USA

    Science.gov (United States)

    Athearn, Nicole D.; Takekawa, John Y.; Shinn, Joel

    2009-01-01

    Restoration of former commercial salt evaporation ponds in the San Francisco Bay estuary is intended to reverse a severe decline (>79%) in tidal salt marshes. San Francisco Bay is a critical migratory stopover site and wintering area for shorebirds and waterfowl, and salt ponds are important high tide roosting and foraging areas. Conservation of past bird abundance is a stated goal of area restoration projects, and early adaptive management will be critical for achieving this objective. However, initial avian response at sites restored to tidal flow may not be indicative of long-term results. For example, winter shorebirds at a 529 ha pond breached in 2002 showed a marked increase in shorebird abundance following breaching. Shorebirds comprised 1% of area totals during 1999-2002 and increased to 46% during 2003-2008. These changes accompanied increased tidal range and sedimentation, but minimal vegetation establishment. Conversely, a fully vegetated, restored 216 ha pond in the same system consistently supported less than 2% of all waterbirds in the region. Early restoration may temporarily increase habitat, but managed ponds will be needed for long-term waterbird abundance within a restored pond-marsh system.

  19. Impacts of an underwater high voltage DC power cable on fish migration movements in the San Francisco Bay.

    Science.gov (United States)

    Wyman, M. T.; Kavet, R.; Klimley, A. P.

    2016-02-01

    There is an increasingly strong interest on a global scale in offshore renewable energy production and transportation. However, there is concern that the electromagnetic fields (EMF) produced by these underwater cables may alter the behavior and physiology of marine species. Despite this concern, few studies have investigated these effects in free-living species. In 2009, a 85 km long high-voltage DC (HVDC) power cable was placed within the San Francisco Bay, running parallel, then perpendicular to, the migration route of anadromous species moving from the inland river system to the oceans. In this study, we assess the impacts of this HVDC cable on the migration behaviors of EMF-sensitive fish, including juvenile salmonids (Chinook salmon, Oncorhynchus tshawytscha, and steelhead trout, Oncorhynchus mykiss) and adult green sturgeon, Acipenser medirostris. Acoustic telemetry techniques were used to track fish migration movements through the San Francisco Bay both before and after the cable was activated; individuals implanted with acoustic transmitters were detected on cross-channel hydrophone arrays at key locations in the system. Magnetic fields were surveyed and mapped at these locations using a transverse gradiometer, and models of the cable's magnetic field were developed that closely matched the empirically measured values. Here, we present our analyses on the relationships between migration-related behavioral metrics (e.g., percent of successful migrations, duration of migration, time spent near vs. far from cable location, etc.) and environmental parameters, such as cable activation and load level, local magnetic field levels, depth, and currents.

  20. Six-year mortality in a street-recruited cohort of homeless youth in San Francisco, California

    Directory of Open Access Journals (Sweden)

    Colette L. Auerswald

    2016-04-01

    Full Text Available Objectives. The mortality rate of a street-recruited homeless youth cohort in the United States has not yet been reported. We examined the six-year mortality rate for a cohort of street youth recruited from San Francisco street venues in 2004. Methods. Using data collected from a longitudinal, venue-based sample of street youth 15–24 years of age, we calculated age, race, and gender-adjusted mortality rates. Results. Of a sample of 218 participants, 11 died from enrollment in 2004 to December 31, 2010. The majority of deaths were due to suicide and/or substance abuse. The death rate was 9.6 deaths per hundred thousand person-years. The age, race and gender-adjusted standardized mortality ratio was 10.6 (95% CI [5.3–18.9]. Gender specific SMRs were 16.1 (95% CI [3.3–47.1] for females and 9.4 (95% CI [4.0–18.4] for males. Conclusions. Street-recruited homeless youth in San Francisco experience a mortality rate in excess of ten times that of the state’s general youth population. Services and programs, particularly housing, mental health and substance abuse interventions, are urgently needed to prevent premature mortality in this vulnerable population.

  1. Benthic flux of nutrients and trace metals in the northern component of San Francisco Bay, California

    Science.gov (United States)

    Kuwabara, James S.; Topping, Brent R.; Parcheso, Francis; Engelstad, Anita C.; Greene, Valerie E.

    2009-01-01

    Two sets of sampling trips were coordinated in late summer 2008 (weeks of July 8 and August 6) to sample the interstitial and overlying bottom waters at 10 shallow locations (9 sites meters in depth) within the northern component of the San Francisco Bay/Delta (herein referred to as North Bay). The work was performed to better understand sources of biologically reactive solutes (namely, dissolved macronutrients and trace metals) that may affect the base of the food web in this part of the estuary. A nonmetallic pore-water profiler was used to obtain the first centimeter-scale estimates of the vertical solute-concentration gradients for diffusive-flux determinations. This study, performed in collaboration with scientists from San Francisco State University?s Romberg Tiburon Center for Environmental Studies, provides information to assist in developing and refining management strategies for the Bay/Delta system and supports efforts to monitor changes in food-web structure associated with regional habitat modifications directed by the California Bay-Delta Authority. On July 7, 2008, and August 5, 2008, pore-water profilers were successfully deployed at six North Bay sites per trip to measure the concentration gradient of dissolved macronutrients and trace metals near the sediment-water interface. Only two of the sites (433 and SSB009 within Honker Bay) were sampled in both series of profiler deployments. At each sampling site, profilers were deployed in triplicate, while discrete samples and dataloggers were used to collect ancillary data from both the water column and benthos to help interpret diffusive-flux measurements. Benthic flux of dissolved (0.2-micron filtered) inorganic phosphate (that is, soluble reactive phosphorus (SRP)) ranged from negligible levels (-0.003?0.005 millimole per square meter per day (mmole m-2d-1) at Site 4.1 outside Honker Bay) to 0.060?0.006 mmole m-2d-1 near the northern coast of Brown?s Island. Except for the elevated flux at Browns

  2. Effects of local geology on ground motion in the San Francisco Bay region, California—A continued study

    Science.gov (United States)

    Gibbs, James F.; Borcherdt, Roger D.

    1974-01-01

    Measurements of ground motion generated by nuclear explosions in Nevada have been completed for 99 locations in the San Francisco Bay region, California. The seismograms, Fourier amplitude spectra, spectral amplification curves for the signal, and the Fourier amplitude spectra of the seismic noise are presented for 60 locations. Analog amplifications, based on the maximum signal amplitude, are computed for an additional 39 locations. The recordings of the nuclear explosions show marked amplitude variations which are consistently related to the local geologic conditions of the recording site. The average spectral amplifications observed for vertical and horizontal ground motions are, respectively: (1, 1) for granite, (1.5, 1.6) for the Franciscan Formation, (2.3, 2.3), for other pre-Tertiary and Tertiary rocks, (3.0, 2.7) for the Santa Clara Formation, (3.3, 4.4) for older bay sediments, and (3.7, 11.3) for younger bay mud. Spectral amplification curves define predominant ground frequencies for younger bay mud sites and for some older bay sediment sites. The predominant frequencies for most sites were not clearly defined by the amplitude spectra computed from the seismic background noise. The intensities ascribed to various sites in the San Francisco Bay region for the California earthquake of April 18, 1906, are strongly dependent on distance from the zone of surface faulting and the geological character of the ground. Considering only those sites (approximately one square city block in size) for which there is good evidence for the degree of ascribed intensity, the intensities for 917 sites on Franciscan rocks generally decrease with the logarithm of distance as Intensity = 2.69 - 1.90 log (Distance Km). For sites on other geologic units, intensity increments, derived from this empirical rela.tion, correlate strongly with the Average Horizontal Spectral Amplifications (MISA) according to the empirical relation Intensity Increment= 0.27 + 2.70 log(AHSA). Average

  3. Slicing up the San Francisco Bay Area: Block kinematics and fault slip rates from GPS-derived surface velocities

    Science.gov (United States)

    d'Alessio, M. A.; Johanson, I.A.; Burgmann, R.; Schmidt, D.A.; Murray, M.H.

    2005-01-01

    Observations of surface deformation allow us to determine the kinematics of faults in the San Francisco Bay Area. We present the Bay Area velocity unification (BA??VU??, "bay view"), a compilation of over 200 horizontal surface velocities computed from campaign-style and continuous Global Positioning System (GPS) observations from 1993 to 2003. We interpret this interseismic velocity field using a three-dimensional block model to determine the relative contributions of block motion, elastic strain accumulation, and shallow aseismic creep. The total relative motion between the Pacific plate and the rigid Sierra Nevada/Great Valley (SNGV) microplate is 37.9 ?? 0.6 mm yr-1 directed toward N30.4??W ?? 0.8?? at San Francisco (??2??). Fault slip rates from our preferred model are typically within the error bounds of geologic estimates but provide a better fit to geodetic data (notable right-lateral slip rates in mm yr-1: San Gregorio fault, 2.4 ?? 1.0; West Napa fault, 4.0 ?? 3.0; zone of faulting along the eastern margin of the Coast Range, 5.4 ?? 1.0; and Mount Diablo thrust, 3.9 ?? 1.0 of reverse slip and 4.0 ?? 0.2 of right-lateral strike slip). Slip on the northern Calaveras is partitioned between both the West Napa and Concord/ Green Valley fault systems. The total convergence across the Bay Area is negligible. Poles of rotation for Bay Area blocks progress systematically from the North America-Pacific to North America-SNGV poles. The resulting present-day relative motion cannot explain the strike of most Bay Area faults, but fault strike does loosely correlate with inferred plate motions at the time each fault initiated. Copyright 2005 by the American Geophysical Union.

  4. Reducing methylmercury accumulation in the food webs of San Francisco Bay and its local watersheds

    International Nuclear Information System (INIS)

    Davis, J.A.; Looker, R.E.; Yee, D.; Marvin-Di Pasquale, M.; Grenier, J.L.; Austin, C.M.; McKee, L.J.; Greenfield, B.K.; Brodberg, R.; Blum, J.D.

    2012-01-01

    San Francisco Bay (California, USA) and its local watersheds present an interesting case study in estuarine mercury (Hg) contamination. This review focuses on the most promising avenues for attempting to reduce methylmercury (MeHg) contamination in Bay Area aquatic food webs and identifying the scientific information that is most urgently needed to support these efforts. Concern for human exposure to MeHg in the region has led to advisories for consumption of sport fish. Striped bass from the Bay have the highest average Hg concentration measured for this species in USA estuaries, and this degree of contamination has been constant for the past 40 years. Similarly, largemouth bass in some Bay Area reservoirs have some of the highest Hg concentrations observed in the entire US. Bay Area wildlife, particularly birds, face potential impacts to reproduction based on Hg concentrations in the tissues of several Bay species. Source control of Hg is one of the primary possible approaches for reducing MeHg accumulation in Bay Area aquatic food webs. Recent findings (particularly Hg isotope measurements) indicate that the decades-long residence time of particle-associated Hg in the Bay is sufficient to allow significant conversion of even the insoluble forms of Hg into MeHg. Past inputs have been thoroughly mixed throughout this shallow and dynamic estuary. The large pool of Hg already present in the ecosystem dominates the fraction converted to MeHg and accumulating in the food web. Consequently, decreasing external Hg inputs can be expected to reduce MeHg in the food web, but it will likely take many decades to centuries before those reductions are achieved. Extensive efforts to reduce loads from the largest Hg mining source (the historic New Almaden mining district) are underway. Hg is spread widely across the urban landscape, but there are a number of key sources, source areas, and pathways that provide opportunities to capture larger quantities of Hg and reduce loads

  5. Reducing methylmercury accumulation in the food webs of San Francisco Bay and its local watersheds

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J.A., E-mail: jay@sfei.org [San Francisco Estuary Institute, 4911 Central Avenue, Richmond, CA 94804 (United States); Looker, R.E. [San Francisco Bay Regional Water Quality Control Board, 1515 Clay Street, Suite 1400, Oakland, CA 94612 (United States); Yee, D. [San Francisco Estuary Institute, 4911 Central Avenue, Richmond, CA 94804 (United States); Marvin-Di Pasquale, M. [U.S. Geological Survey, Water Resources Division/MS 480, 345 Middlefield Road, Menlo Park, CA 94025 (United States); Grenier, J.L. [San Francisco Estuary Institute, 4911 Central Avenue, Richmond, CA 94804 (United States); Austin, C.M. [San Francisco Bay Regional Water Quality Control Board, 1515 Clay Street, Suite 1400, Oakland, CA 94612 (United States); McKee, L.J.; Greenfield, B.K. [San Francisco Estuary Institute, 4911 Central Avenue, Richmond, CA 94804 (United States); Brodberg, R. [California Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, 1001 I Street, Sacramento, CA 95812 (United States); Blum, J.D. [Department of Geological Sciences, University of Michigan, 1100 North University Avenue, Ann Arbor, MI 48109 (United States)

    2012-11-15

    San Francisco Bay (California, USA) and its local watersheds present an interesting case study in estuarine mercury (Hg) contamination. This review focuses on the most promising avenues for attempting to reduce methylmercury (MeHg) contamination in Bay Area aquatic food webs and identifying the scientific information that is most urgently needed to support these efforts. Concern for human exposure to MeHg in the region has led to advisories for consumption of sport fish. Striped bass from the Bay have the highest average Hg concentration measured for this species in USA estuaries, and this degree of contamination has been constant for the past 40 years. Similarly, largemouth bass in some Bay Area reservoirs have some of the highest Hg concentrations observed in the entire US. Bay Area wildlife, particularly birds, face potential impacts to reproduction based on Hg concentrations in the tissues of several Bay species. Source control of Hg is one of the primary possible approaches for reducing MeHg accumulation in Bay Area aquatic food webs. Recent findings (particularly Hg isotope measurements) indicate that the decades-long residence time of particle-associated Hg in the Bay is sufficient to allow significant conversion of even the insoluble forms of Hg into MeHg. Past inputs have been thoroughly mixed throughout this shallow and dynamic estuary. The large pool of Hg already present in the ecosystem dominates the fraction converted to MeHg and accumulating in the food web. Consequently, decreasing external Hg inputs can be expected to reduce MeHg in the food web, but it will likely take many decades to centuries before those reductions are achieved. Extensive efforts to reduce loads from the largest Hg mining source (the historic New Almaden mining district) are underway. Hg is spread widely across the urban landscape, but there are a number of key sources, source areas, and pathways that provide opportunities to capture larger quantities of Hg and reduce loads

  6. The Female/Male Salary Differential in Public Schools: Some Lessons from San Francisco, 1879. Program Report No. 79-B7.

    Science.gov (United States)

    Strober, Myra H.; Best, Laura

    This paper develops a theory of sex differences in the earnings of school personnel, with emphasis on the role of labor market segmentation. Several aspects of the theory are then tested using data for the San Francisco school system in 1879. Section 1 develops a theory of sex differences in the earnings of school personnel. Section 2 discusses…

  7. Foreign Language Folio. A Guide to Cultural Resources and Field Trip Opportunities in the San Francisco Bay Area for Teachers and Students of Foreign Languages, 1983-85.

    Science.gov (United States)

    Gonzales, Tony, Ed.; O'Connor, Roger, Ed.

    A listing of San Francisco area cultural resources and opportunities of use to foreign language teachers is presented. Included are the following: museums and galleries, schools, art sources, churches, clubs, cultural centers and organizations, publications and publishing companies, restaurants, food stores and markets, travel and tourism,…

  8. Ferroelectric Thin Films III, Symposium Held in San Francisco, California on April 13 - 16, 1993. Materials Research Society Symposium Proceedings, Volume 310

    Science.gov (United States)

    1993-04-16

    Publication Data Ferroelectric thin films III : symposium held April 13-16, 1993, San Francisco,California, U.S.A. / editors, Bruce A. Turtle , Edwlrd R...All solutions were placed in a modified Collison Nebulizer which generated the droplets in an oxygen carrier gas. The droplets were transported into

  9. Muusikamaailm : Brüsseli La Monnaie ئ 300. Uusooper San Franciscos. Sibeliuse nädal esiettekannetega. Cesare Valletti surnud / Priit Kuusk

    Index Scriptorium Estoniae

    Kuusk, Priit, 1938-

    2000-01-01

    Brüsseli teater Theatre Royal de la Monnaie sai linnalt 300. juubeli kingituseks lisaruume, hooaja ooperiesiettekannetest teatris. J. Heggie ooperi "Dead man walking" maailmaesiettekandest San Francisco Ooperis. 30.sept.-8. okt. toimunud Sibeliuse nädalast Järvenpää-talos. Lühidalt C. Vallettist

  10. Engineers at the Golden Gate: A History of the San Francisco District U.S. Army Corps of Engineers 1866-1980

    Science.gov (United States)

    1980-01-01

    long-distance, endurance horse ride. A rather unique activity is the special observance of Native American Day, held to pay tribute to the Porno ...by San Francisco District in conjunction with the Mendocino Porno Council, a Native-American organization, to promote American Indian heritage and

  11. Creep and drying shrinkage of high performance concrete for the skyway structures of the new San Francisco-Oakland Bay Bridge and cement paste

    Science.gov (United States)

    2011-03-01

    The objective of this study was to determine the influence of admixtures on long term drying shrinkage and creep of high : strength concrete (HSC). Creep and shrinkage of the mix utilized in segments of the Skyway Structure of the San : Francisco-Oak...

  12. Co-Production of Actionable Science: Recommendations to the Secretary of Interior and a San Francisco Case Study

    Science.gov (United States)

    Behar, D. H.; Pfeffer, W. T.; Beier, P.

    2015-12-01

    "Actionable Science provides data, analyses, projections, or tools that can support decisions regarding the management of the risks and impacts of climate change. It is ideally co-produced by scientists and decision makers and creates rigorous and accessible products to meet the needs of stakeholders. (Report to the Secretary of the Interior, Advisory Committee on Climate Change and Natural Resource Science (ACCCNRS), March 30, 2015)During one 17 month period ending in 2013, three major reports on sea level rise from three highly respected science providers produced three divergent estimates of sea level rise. These reports collectively flummoxed the lay reader seeking direction for adaptation planning. Guidance documents soon emerged from state entities which caused further confusion. The City and County of San Francisco began developing "Guidance for Incorporating Sea Level Rise into Capital Planning" in 2013 at the direction of San Francisco Mayor Edwin Lee (http://onesanfrancisco.org/staff-resources/sea-level-rise-guidance/). The first task in developing this Guidance was to convert these highly technical reports into "actionable science." This required extensive expert elicitation to tease out their meaning and use value for decision making. This process, which resulted in detailed guidance on the use of SLR science in planning, is increasingly being called "co-production."Co-production requires both scientist and decision-maker to hear the other's perspective, reflect upon the decision-maker's precise needs, and translate peer review science into lay language and practical advice for decision making. The co-production dynamic was the subject of extensive discussion in the federal Advisory Committee on Climate Change and Natural Resource Science. The ACCCNRS recommendations (https://nccwsc.usgs.gov/acccnrs) include not only the new definition of Actionable Science cited above, but also a "How-To-Guide" that outlines principles for successfully creating a co

  13. Ground-motion modeling of the 1906 San Francisco Earthquake, part II: Ground-motion estimates for the 1906 earthquake and scenario events

    Science.gov (United States)

    Aagaard, Brad T.; Brocher, T.M.; Dolenc, D.; Dreger, D.; Graves, R.W.; Harmsen, S.; Hartzell, S.; Larsen, S.; McCandless, K.; Nilsson, S.; Petersson, N.A.; Rodgers, A.; Sjogreen, B.; Zoback, M.L.

    2008-01-01

    We estimate the ground motions produce by the 1906 San Francisco earthquake making use of the recently developed Song et al. (2008) source model that combines the available geodetic and seismic observations and recently constructed 3D geologic and seismic velocity models. Our estimates of the ground motions for the 1906 earthquake are consistent across five ground-motion modeling groups employing different wave propagation codes and simulation domains. The simulations successfully reproduce the main features of the Boatwright and Bundock (2005) ShakeMap, but tend to over predict the intensity of shaking by 0.1-0.5 modified Mercalli intensity (MMI) units. Velocity waveforms at sites throughout the San Francisco Bay Area exhibit characteristics consistent with rupture directivity, local geologic conditions (e.g., sedimentary basins), and the large size of the event (e.g., durations of strong shaking lasting tens of seconds). We also compute ground motions for seven hypothetical scenarios rupturing the same extent of the northern San Andreas fault, considering three additional hypocenters and an additional, random distribution of slip. Rupture directivity exerts the strongest influence on the variations in shaking, although sedimentary basins do consistently contribute to the response in some locations, such as Santa Rosa, Livermore, and San Jose. These scenarios suggest that future large earthquakes on the northern San Andreas fault may subject the current San Francisco Bay urban area to stronger shaking than a repeat of the 1906 earthquake. Ruptures propagating southward towards San Francisco appear to expose more of the urban area to a given intensity level than do ruptures propagating northward.

  14. Recent scientific advances and their implications for sand management near San Francisco, California: the influences of the ebb tidal delta

    Science.gov (United States)

    Hanes, Daniel M.; Barnard, Patrick L.; Dallas, Kate; Elias, Edwin; Erikson, Li H.; Eshleman, Jodi; Hansen, Jeff; Hsu, Tian Jian; Shi, Fengyan

    2011-01-01

    Recent research in the San Francisco, California, U.S.A., coastal region has identified the importance of the ebb tidal delta to coastal processes. A process-based numerical model is found to qualitatively reproduce the equilibrium size and shape of the delta. The ebb tidal delta itself has been contracting over the past century, and the numerical model is applied to investigate the sensitivity of the delta to changes in forcing conditions. The large ebb tidal delta has a strong influence upon regional coastal processes. The prominent bathymetry of the ebb tidal delta protects some of the coast from extreme storm waves, but the delta also focuses wave energy toward the central and southern portions of Ocean Beach. Wave focusing likely contributes to a chronic erosion problem at the southern end of Ocean Beach. The ebb tidal delta in combination with non-linear waves provides a potential cross-shore sediment transport pathway that probably supplies sediment to Ocean Beach.

  15. National Account Energy Alliance Final Report for the Ritz Carlton, San Francisco Combined Heat and Power Project

    Energy Technology Data Exchange (ETDEWEB)

    Rosfjord, Thomas J [UTC Power

    2007-11-01

    Under collaboration between DOE and the Gas Technology Institute (GTI), UTC Power partnered with Host Hotels and Resorts to install and operate a PureComfort 240M Cooling, Heating and Power (CHP) System at the Ritz-Carlton, San Francisco. This packaged CHP system integrated four microturbines, a double-effect absorption chiller, two fuel gas boosters, and the control hardware and software to ensure that the system operated predictably, reliably, and safely. The chiller, directly energized by the recycled hot exhaust from the microturbines, could be configured to provide either chilled or hot water. As installed, the system was capable of providing up to 227 kW of net electrical power and 142 RT of chilled water at a 59F ambient temperature.

  16. Bioaccumulation of hydrocarbons derived from terrestrial and anthropogenic sources in the Asian clam, Potamocorbula amurensis, in San Francisco Bay estuary

    Science.gov (United States)

    Pereira, Wilfred E.; Hostettler, Frances D.; Rapp, John B.

    1992-01-01

    An assessment was made in Suisun Bay, California, of the distributions of hydrocarbons in estuarine bed and suspended sediments and in the recently introduced asian clam, Potamocorbula amurensis. Sediments and clams were contaminated with hydrocarbons derived from petrogenic and pyrogenic sources. Distributions of alkanes and of hopane and sterane biomarkers in sediments and clams were similar, indicating that petroleum hydrocarbons associated with sediments are bioavailable to Potamocorbula amurensis. Polycyclic aromatic hydrocarbons in the sediments and clams were derived mainly from combustion sources. Potamocorbula amurensis is therefore a useful bioindicator of hydrocarbon contamination, and may be used as a biomonitor of hydrocarbon pollution in San Francisco Bay.

  17. The impact of Hurricane Hugo and the San Francisco earthquake on a sample of people with rheumatoid arthritis.

    Science.gov (United States)

    Grady, K E; Reisine, S T; Fifield, J; Lee, N R; McVay, J; Kelsey, M E

    1991-06-01

    The health effects of two natural disasters on 32 people with rheumatoid arthritis (RA) were assessed during the second-year wave of interviews in an ongoing 3-year study. Although the severity of Hurricane Hugo exceeded that of the San Francisco earthquake, no significant differences in health impacts were found. Both groups reported significantly increased ratings of RA activity, pain, and depression compared with ratings during the first year. However, comparison with the rest of the sample (n = 767) showed that increases in disease activity and pain were a general phenomenon but that the increase in depression was unique to the disaster subsample. Physician health status assessments also indicated that those who experienced the disaster were more likely to be classified in later stages of the disease subsequent to the disaster and were more likely to experience flares. These results suggest that people with RA may constitute a special high-risk population for adverse health effects after natural disasters.

  18. Operation of a real-time warning system for debris flows in the San Francisco bay area, California

    Science.gov (United States)

    Wilson, Raymond C.; Mark, Robert K.; Barbato, Gary; ,

    1993-01-01

    The United States Geological Survey (USGS) and the National Weather Service (NWS) have developed an operational warning system for debris flows during severe rainstorms in the San Francisco Bay region. The NWS makes quantitative forecasts of precipitation from storm systems approaching the Bay area and coordinates a regional network of radio-telemetered rain gages. The USGS has formulated thresholds for the intensity and duration of rainfall required to initiate debris flows. The first successful public warnings were issued during a severe storm sequence in February 1986. Continued operation of the warning system since 1986 has provided valuable working experience in rainfall forecasting and monitoring, refined rainfall thresholds, and streamlined procedures for issuing public warnings. Advisory statements issued since 1986 are summarized.

  19. Highest PBDE levels (max 63 ppm) yet found in biota measured in seabird eggs from San Francisco Bay

    Energy Technology Data Exchange (ETDEWEB)

    She, J.; Holden, A.; Tanner, M.; Sharp, M.; Hooper, K. [Department of Toxic Substances Control, Berkeley, CA (United States). Hazardous Materials Lab.; Adelsbach, T. [Environmental Contaminants Division, Sacramento Fish and Wildlife Office, US Fish and Wildlife Service, Sacramento, CA (United States)

    2004-09-15

    High levels of polybrominated diphenylethers (PBDEs) have been found in humans and wildlife from the San Francisco Bay Area, with levels in women among the highest in the world, and levels in piscivorous seabird eggs at the ppm level. Seabirds are useful for monitoring and assessing ecosystem health at various times and places because they occupy a high trophic level in the marine food web, are long-lived, and are generally localized near their breeding and non-breeding sites. In collaboration with the US Fish and Wildlife Services (USFWS), we are carrying out a three-year investigation of dioxin, PCB and PBDE levels in eggs from fish-eating seabirds. Year 1 (2002) PBDE measurements from 73 bird eggs were reported at Dioxin2003. Year 2 (2003) PBDE measurements from 45 samples are presented in this report. The highest PBDE level measured in eggs was 63 ppm, lipid, which is the highest PBDE level, yet reported in biota.

  20. HIV vaccine trial willingness among injection and non-injection drug users in two urban centres, Barcelona and San Francisco.

    Science.gov (United States)

    Etcheverry, M Florencia; Lum, Paula J; Evans, Jennifer L; Sanchez, Emilia; de Lazzari, Elisa; Mendez-Arancibia, Eva; Sierra, Ernesto; Gatell, José M; Page, Kimberly; Joseph, Joan

    2011-02-24

    Being able to recruit high-risk volunteers who are also willing to consider future participation in vaccine trials are critical features of vaccine preparedness studies. We described data from two cohorts of injection- and non-injection drug users in Barcelona, Spain [Red Cross centre] and in San Francisco, USA, [UFO-VAX study] at high risk of HIV/HCV infection to assess behaviour risk exposure and willingness to participate in future preventive HIV vaccine trials. We successfully identified drug-using populations that would be eligible for future HIV vaccine efficacy trials, based on reported levels of risk during screening and high levels of willingness to participate. In both groups, Red Cross and UFO-VAX respectively, HCV infection was highly prevalent at baseline (41% and 34%), HIV baseline seroprevalence was 4.2% and 1.5%, and high levels of willingness were seen (83% and 78%). Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Change in Urban Land Use and Associated Attributes in the Upper San Francisco Estuary, 1990-2006

    Directory of Open Access Journals (Sweden)

    David M. Stoms

    2010-09-01

    Full Text Available Land use is an ultimate driver of many of the stressors on the Upper San Francisco Estuary, but the magnitude and pattern of land use change has not been analyzed. This paper attempts to fill this knowledge gap through a screening-level risk assessment. Urban land use was compared within hydrodynamic subregions in 1990, 2000, and 2006. Ancillary data were then used to quantify secondary measures such as impervious cover, housing density, road density and road crossings. Despite the rapid growth of the Bay Area, Sacramento, and Stockton metropolitan areas, the percentage of urban area and rates of change in the subregions are generally low to moderate when compared to other estuaries in the United States. The spatial data sets used in this analysis have been posted online to a public repository to be used by other researchers.

  2. Building leadership among laboratory-based and clinical and translational researchers: the University of California, San Francisco experience.

    Science.gov (United States)

    Wides, Cynthia; Mertz, Elizabeth; Lindstaedt, Bill; Brown, Jeanette

    2014-02-01

    In 2005 the University of California, San Francisco (UCSF) implemented the Scientific Leadership and Management (SLM) course, a 2-day leadership training program to assist laboratory-based postdoctoral scholars in their transition to independent researchers managing their own research programs. In 2011, the course was expanded to clinical and translational junior faculty and fellows. The course enrollment was increased from approximate 100 to 123 participants at the same time. Based on course evaluations, the number and percent of women participants appears to have increased over time from 40% (n = 33) in 2007 to 53% (n = 58) in 2011. Course evaluations also indicated that participants found the course to be relevant and valuable in their transition to academic leadership. This paper describes the background, structure, and content of the SLM and reports on participant evaluations of the course offerings from 2007 through 2011. © 2014 Wiley Periodicals, Inc.

  3. Water quality measurements in San Francisco Bay by the U.S. Geological Survey, 1969-2015.

    Science.gov (United States)

    Schraga, Tara S; Cloern, James E

    2017-08-08

    The U.S. Geological Survey (USGS) maintains a place-based research program in San Francisco Bay (USA) that began in 1969 and continues, providing one of the longest records of water-quality measurements in a North American estuary. Constituents include salinity, temperature, light extinction coefficient, and concentrations of chlorophyll-a, dissolved oxygen, suspended particulate matter, nitrate, nitrite, ammonium, silicate, and phosphate. We describe the sampling program, analytical methods, structure of the data record, and how to access all measurements made from 1969 through 2015. We provide a summary of how these data have been used by USGS and other researchers to deepen understanding of how estuaries are structured and function differently from the river and ocean ecosystems they bridge.

  4. The Aquatic Trophic Ecology of Suisun Marsh, San Francisco Estuary, California, During Autumn in a Wet Year

    Directory of Open Access Journals (Sweden)

    Robert E. Schroeter

    2015-09-01

    Full Text Available doi: http://dx.doi.org/10.15447/sfews.v13iss3art6Using stable isotopes of carbon (δ13C and nitrogen (δ15N and mixing models, we investigated the trophic levels and carbon sources of invertebrates and fishes of a large tidal marsh in the San Francisco Estuary. Our goal was to better understand an estuarine food web comprised of native and alien species. We found the following: (1 the food web was based largely on carbon from phytoplankton and emergent-aquatic and terrestrial vegetation, but carbon from submerged aquatic vegetation and phytobenthos was also used; (2 alien species increased the complexity of the food web by altering carbon-flow pathways and by occupying trophic positions different from native species; and (3 most consumers were dietary generalists.

  5. Modeling the Gila-San Francisco Basin using system dynamics in support of the 2004 Arizona Water Settlement Act.

    Energy Technology Data Exchange (ETDEWEB)

    Tidwell, Vincent Carroll; Sun, Amy Cha-Tien; Peplinski, William J.; Klise, Geoffrey Taylor

    2012-04-01

    Water resource management requires collaborative solutions that cross institutional and political boundaries. This work describes the development and use of a computer-based tool for assessing the impact of additional water allocation from the Gila River and the San Francisco River prescribed in the 2004 Arizona Water Settlements Act. Between 2005 and 2010, Sandia National Laboratories engaged concerned citizens, local water stakeholders, and key federal and state agencies to collaboratively create the Gila-San Francisco Decision Support Tool. Based on principles of system dynamics, the tool is founded on a hydrologic balance of surface water, groundwater, and their associated coupling between water resources and demands. The tool is fitted with a user interface to facilitate sensitivity studies of various water supply and demand scenarios. The model also projects the consumptive use of water in the region as well as the potential CUFA (Consumptive Use and Forbearance Agreement which stipulates when and where Arizona Water Settlements Act diversions can be made) diversion over a 26-year horizon. Scenarios are selected to enhance our understanding of the potential human impacts on the rivers ecological health in New Mexico; in particular, different case studies thematic to water conservation, water rights, and minimum flow are tested using the model. The impact on potential CUFA diversions, agricultural consumptive use, and surface water availability are assessed relative to the changes imposed in the scenarios. While it has been difficult to gage the acceptance level from the stakeholders, the technical information that the model provides are valuable for facilitating dialogues in the context of the new settlement.

  6. Impacts of representing sea-level rise uncertainty on future flood risks: An example from San Francisco Bay.

    Science.gov (United States)

    Ruckert, Kelsey L; Oddo, Perry C; Keller, Klaus

    2017-01-01

    Rising sea levels increase the probability of future coastal flooding. Many decision-makers use risk analyses to inform the design of sea-level rise (SLR) adaptation strategies. These analyses are often silent on potentially relevant uncertainties. For example, some previous risk analyses use the expected, best, or large quantile (i.e., 90%) estimate of future SLR. Here, we use a case study to quantify and illustrate how neglecting SLR uncertainties can bias risk projections. Specifically, we focus on the future 100-yr (1% annual exceedance probability) coastal flood height (storm surge including SLR) in the year 2100 in the San Francisco Bay area. We find that accounting for uncertainty in future SLR increases the return level (the height associated with a probability of occurrence) by half a meter from roughly 2.2 to 2.7 m, compared to using the mean sea-level projection. Accounting for this uncertainty also changes the shape of the relationship between the return period (the inverse probability that an event of interest will occur) and the return level. For instance, incorporating uncertainties shortens the return period associated with the 2.2 m return level from a 100-yr to roughly a 7-yr return period (∼15% probability). Additionally, accounting for this uncertainty doubles the area at risk of flooding (the area to be flooded under a certain height; e.g., the 100-yr flood height) in San Francisco. These results indicate that the method of accounting for future SLR can have considerable impacts on the design of flood risk management strategies.

  7. San Francisco Estuary Striped Bass Migration History Determined by Electron-microprobe Analysis of Otolith Sr/Ca Ratio

    Energy Technology Data Exchange (ETDEWEB)

    Ostrach, D J; Phillis, C C; Weber, P K; Ingram, B L; Zinkl, J G

    2004-09-17

    Habitat use has been shown to be an important factor in the bioaccumulation of contaminants in striped bass. This study examines migration in striped bass as part of a larger study investigating bioaccumulation and maternal transfer of xenobiotics to progeny in the San Francisco Estuary system. Habitat use, residence time and spawning migration over the life of females (n = 23) was studied. Female striped bass were collected between Knights Landing and Colusa on the Sacramento River during the spawning runs of 1999 and 2001. Otoliths were removed, processed and aged via otolith microstructure. Subsequently, otoliths were analyzed for strontium/calcium (Sr/Ca) ratio using an electron-microprobe to measure salinity exposure and to distinguish freshwater, estuary, and marine habitat use. Salinity exposure during the last year before capture was examined more closely for comparison of habitat use by the maternal parent to contaminant burden transferred to progeny. Results were selectively confirmed by ion microprobe analyses for habitat use. The Sr/Ca data demonstrate a wide range of migratory patterns. Age of initial ocean entry differs among individuals before returning to freshwater, presumably to spawn. Some fish reside in freshwater year-round, while others return to more saline habitats and make periodic migrations to freshwater. Frequency of habitat shifts and residence times differs among fish, as well as over the lifetime of individual fish. While at least one fish spent its final year in freshwater, the majority of spawning fish spent their final year in elevated salinity. However, not all fish migrated to freshwater to spawn in the previous year. Results from this investigation concerning migration history in striped bass can be combined with contaminant and histological developmental analyses to better understand the bioaccumulation of contaminants and the subsequent effects they and habitat use have on fish populations in the San Francisco Estuary system.

  8. Early detection of tuberculosis outbreaks among the San Francisco homeless: trade-offs between spatial resolution and temporal scale.

    Directory of Open Access Journals (Sweden)

    Brandon W Higgs

    Full Text Available BACKGROUND: San Francisco has the highest rate of tuberculosis (TB in the U.S. with recurrent outbreaks among the homeless and marginally housed. It has been shown for syndromic data that when exact geographic coordinates of individual patients are used as the spatial base for outbreak detection, higher detection rates and accuracy are achieved compared to when data are aggregated into administrative regions such as zip codes and census tracts. We examine the effect of varying the spatial resolution in the TB data within the San Francisco homeless population on detection sensitivity, timeliness, and the amount of historical data needed to achieve better performance measures. METHODS AND FINDINGS: We apply a variation of space-time permutation scan statistic to the TB data in which a patient's location is either represented by its exact coordinates or by the centroid of its census tract. We show that the detection sensitivity and timeliness of the method generally improve when exact locations are used to identify real TB outbreaks. When outbreaks are simulated, while the detection timeliness is consistently improved when exact coordinates are used, the detection sensitivity varies depending on the size of the spatial scanning window and the number of tracts in which cases are simulated. Finally, we show that when exact locations are used, smaller amount of historical data is required for training the model. CONCLUSION: Systematic characterization of the spatio-temporal distribution of TB cases can widely benefit real time surveillance and guide public health investigations of TB outbreaks as to what level of spatial resolution results in improved detection sensitivity and timeliness. Trading higher spatial resolution for better performance is ultimately a tradeoff between maintaining patient confidentiality and improving public health when sharing data. Understanding such tradeoffs is critical to managing the complex interplay between public

  9. Understanding processes controlling sediment transports at the mouth of a highly energetic inlet system (San Francisco Bay, CA)

    Science.gov (United States)

    Elias, Edwin P.L.; Hansen, Jeff E.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    San Francisco Bay is one of the largest estuaries along the U.S. West Coast and is linked to the Pacific Ocean through the Golden Gate, a 100 m deep bedrock inlet. A coupled wave, flow and sediment transport model is used to quantify the sediment linkages between San Francisco Bay, the Golden Gate, and the adjacent open coast. Flow and sediment transport processes are investigated using an ensemble average of 24 climatologically derived wave cases and a 24.8 h representative tidal cycle. The model simulations show that within the inlet, flow and sediment transport is tidally dominated and driven by asymmetry of the ebb and flood tides. Peak ebb velocities exceed the peak flood velocities in the narrow Golden Gate channel as a result of flow convergence and acceleration. Persistent flow and sediment gyres at the headland tips are formed that limit sediment transfer from the ebb-tidal delta to the inlet and into the bay. The residual transport pattern in the inlet is dominated by a lateral segregation with a large ebb-dominant sediment transport (and flow) prevailing along the deeper north side of the Golden Gate channel, and smaller flood dominant transports along the shallow southern margin. The seaward edge of the ebb-tidal delta largely corresponds to the seaward extent of strong tidal flows. On the ebb-tidal delta, both waves and tidal forcing govern flow and sediment transport. Wave focusing by the ebb-tidal delta leads to strong patterns of sediment convergence and divergence along the adjacent Ocean Beach.

  10. Impacts of representing sea-level rise uncertainty on future flood risks: An example from San Francisco Bay.

    Directory of Open Access Journals (Sweden)

    Kelsey L Ruckert

    Full Text Available Rising sea levels increase the probability of future coastal flooding. Many decision-makers use risk analyses to inform the design of sea-level rise (SLR adaptation strategies. These analyses are often silent on potentially relevant uncertainties. For example, some previous risk analyses use the expected, best, or large quantile (i.e., 90% estimate of future SLR. Here, we use a case study to quantify and illustrate how neglecting SLR uncertainties can bias risk projections. Specifically, we focus on the future 100-yr (1% annual exceedance probability coastal flood height (storm surge including SLR in the year 2100 in the San Francisco Bay area. We find that accounting for uncertainty in future SLR increases the return level (the height associated with a probability of occurrence by half a meter from roughly 2.2 to 2.7 m, compared to using the mean sea-level projection. Accounting for this uncertainty also changes the shape of the relationship between the return period (the inverse probability that an event of interest will occur and the return level. For instance, incorporating uncertainties shortens the return period associated with the 2.2 m return level from a 100-yr to roughly a 7-yr return period (∼15% probability. Additionally, accounting for this uncertainty doubles the area at risk of flooding (the area to be flooded under a certain height; e.g., the 100-yr flood height in San Francisco. These results indicate that the method of accounting for future SLR can have considerable impacts on the design of flood risk management strategies.

  11. Serum biomarkers of polyfluoroalkyl compound exposure in young girls in Greater Cincinnati and the San Francisco Bay Area, USA

    International Nuclear Information System (INIS)

    Pinney, Susan M.; Biro, Frank M.; Windham, Gayle C.; Herrick, Robert L.; Yaghjyan, Lusine; Calafat, Antonia M.; Succop, Paul; Sucharew, Heidi; Ball, Kathleen M.; Kato, Kayoko

    2014-01-01

    PFC serum concentrations were measured in 6–8 year-old girls in Greater Cincinnati (GC) (N = 353) and the San Francisco Bay Area (SFBA) (N = 351). PFOA median concentration was lower in the SFBA than GC (5.8 vs. 7.3 ng/mL). In GC, 48/51 girls living in one area had PFOA concentrations above the NHANES 95th percentile for children 12–19 years (8.4 ng/mL), median 22.0 ng/mL. The duration of being breast fed was associated with higher serum PFOA at both sites and with higher PFOS, PFHxS and Me-PFOSA-AcOH concentrations in GC. Correlations of the PFC analytes with each other suggest that a source upriver from GC may have contributed to exposures through drinking water, and water treatment with granular activated carbon filtration resulted in less exposure for SWO girls compared to those in NKY. PFOA has been characterized as a drinking water contaminant, and water treatment systems effective in removing PFCs will reduce body burdens. -- Highlights: • PFC serum concentrations were measured in 6–8 year-old girls. • Study sites in Greater Cincinnati (N = 353) and the San Francisco Bay Area (N = 351). • The duration of being breast fed was associated with higher serum PFOA. • Lower PFOA in girls living in areas with granular activated carbon water treatment. -- Serum concentrations of PFCs in young girls were higher in girls who had been breast fed longer, and lower in girls in areas with granular activated carbon municipal water treatment

  12. Think globally, act locally, and collaborate internationally: global health sciences at the University of California, San Francisco.

    Science.gov (United States)

    Macfarlane, Sarah B; Agabian, Nina; Novotny, Thomas E; Rutherford, George W; Stewart, Christopher C; Debas, Haile T

    2008-02-01

    The University of California, San Francisco (UCSF) established Global Health Sciences (GHS) as a campus-wide initiative in 2003. The mission of GHS is to facilitate UCSF's engagement in global health across its four schools by (1) creating a supportive environment that promotes UCSF's leadership role in global health, (2) providing education and training in global health, (3) convening and coordinating global health research activities, (4) establishing global health outreach programs locally in San Francisco and California, (5) partnering with academic centers, especially less-well-resourced institutions in low- and middle-income countries, and (6) developing and collaborating in international initiatives that address neglected global health issues.GHS education programs include a master of science (MS) program expected to start in September 2008, an introduction to global health for UCSF residents, and a year of training at UCSF for MS and PhD students from low- and middle-income countries that is "sandwiched" between years in their own education program and results in a UCSF Sandwich Certificate. GHS's work with partner institutions in California has a preliminary focus on migration and health, and its work with academic centers in low- and middle-income countries focuses primarily on academic partnerships to train human resources for health. Recognizing that the existing academic structure at UCSF may be inadequate to address the complexity of global health threats in the 21st century, GHS is working with the nine other campuses of the University of California to develop a university-wide transdisciplinary initiative in global health.

  13. Comparing Respondent-Driven Sampling and Targeted Sampling Methods of Recruiting Injection Drug Users in San Francisco

    Science.gov (United States)

    Malekinejad, Mohsen; Vaudrey, Jason; Martinez, Alexis N.; Lorvick, Jennifer; McFarland, Willi; Raymond, H. Fisher

    2010-01-01

    The objective of this article is to compare demographic characteristics, risk behaviors, and service utilization among injection drug users (IDUs) recruited from two separate studies in San Francisco in 2005, one which used targeted sampling (TS) and the other which used respondent-driven sampling (RDS). IDUs were recruited using TS (n = 651) and RDS (n = 534) and participated in quantitative interviews that included demographic characteristics, risk behaviors, and service utilization. Prevalence estimates and 95% confidence intervals (CIs) were calculated to assess whether there were differences in these variables by sampling method. There was overlap in 95% CIs for all demographic variables except African American race (TS: 45%, 53%; RDS: 29%, 44%). Maps showed that the proportion of IDUs distributed across zip codes were similar for the TS and RDS sample, with the exception of a single zip code that was more represented in the TS sample. This zip code includes an isolated, predominantly African American neighborhood where only the TS study had a field site. Risk behavior estimates were similar for both TS and RDS samples, although self-reported hepatitis C infection was lower in the RDS sample. In terms of service utilization, more IDUs in the RDS sample reported no recent use of drug treatment and syringe exchange program services. Our study suggests that perhaps a hybrid sampling plan is best suited for recruiting IDUs in San Francisco, whereby the more intensive ethnographic and secondary analysis components of TS would aid in the planning of seed placement and field locations for RDS. PMID:20582573

  14. Interview with Jaime Córtez, Program Manager at the Galería de la Raza, San Francisco, CA, USA, August 14, 2001 Entretien avec Jaime Córtez, directeur de la programmation, Galería de la Raza, San Francisco, CA, États-Unis

    Directory of Open Access Journals (Sweden)

    Gérard Selbach

    2009-10-01

    Full Text Available ForewordLocated at 2857 24th Street, just off Mission Street, at the heart of the Hispanic district in San Francisco, is theGalería de la Raza Co-founded by René Yáñez (cf. interview infra and Ralph Maradiaga in 1970, the Galería was initially funded by the San Francisco Neighborhood Arts Program (NAP which provided the salaries of the directors, equipment and a small budget for exhibitions for a dozen years. The opening showed awareness and compromise on the part of the SF City and of art ...

  15. Critical Assessment of the Delta Smelt Population in the San Francisco Estuary, California

    Directory of Open Access Journals (Sweden)

    William A Bennett

    2005-09-01

    Full Text Available The delta smelt (Hypomesus transpacificus is a small and relatively obscure fish that has recently risen to become a major focus of environmental concern in California. It was formally abundant in the low-salinity and freshwater habitats of the northeastern San Francisco Estuary, but is now listed as threatened under the Federal and California State Endangered Species Acts. In the decade following the listings scientific understanding has increased substantially, yet several key aspects of its biology and ecological relationships within the highly urbanized estuary remain uncertain. A key area of controversy centers on impacts to delta smelt associated with exporting large volumes of freshwater from the estuary to supply California’s significant agricultural and urban water demands. The lack of appropriate data, however, impedes efforts to resolve these issues and develop sound management and restoration alternatives. Delta smelt has an unusual life history strategy relative to many fishes. Some aspects of its biology are similar to other coastal fishes, particularly salmonids. Smelts in the genus, Hypomesus, occur throughout the Pacific Rim, have variable life history strategies, and are able to adapt rapidly to local environments. By comparison, delta smelt has a tiny geographic range being confined to a thin margin of low salinity habitat in the estuary. It primarily lives only a year, has relatively low fecundity, and pelagic larvae; life history attributes that are unusual when compared with many fishes worldwide. A small proportion of delta smelt lives two years. These individuals are relatively highly fecund but are so few in number that their reproductive contribution only may be of benefit to the population after years of extremely poor spawning success and survival. Provisioning of reproductive effort by these older fish may reflect a bet-hedging tactic to insure population persistence. Overall, the population persists by maximizing

  16. Rayleigh wave group velocity and shear wave velocity structure in the San Francisco Bay region from ambient noise tomography

    Science.gov (United States)

    Li, Peng; Thurber, Clifford

    2018-06-01

    We derive new Rayleigh wave group velocity models and a 3-D shear wave velocity model of the upper crust in the San Francisco Bay region using an adaptive grid ambient noise tomography algorithm and 6 months of continuous seismic data from 174 seismic stations from multiple networks. The resolution of the group velocity models is 0.1°-0.2° for short periods (˜3 s) and 0.3°-0.4° for long periods (˜10 s). The new shear wave velocity model of the upper crust reveals a number of important structures. We find distinct velocity contrasts at the Golden Gate segment of the San Andreas Fault, the West Napa Fault, central part of the Hayward Fault and southern part of the Calaveras Fault. Low shear wave velocities are mainly located in Tertiary and Quaternary basins, for instance, La Honda Basin, Livermore Valley and the western and eastern edges of Santa Clara Valley. Low shear wave velocities are also observed at the Sonoma volcanic field. Areas of high shear wave velocity include the Santa Lucia Range, the Gabilan Range and Ben Lomond Plutons, and the Diablo Range, where Franciscan Complex or Silinian rocks are exposed.

  17. Wastewater and Saltwater: Studying the Biogeochemistry and Microbial Activity Associated with Wastewater Inputs to San Francisco Bay

    Science.gov (United States)

    Challenor, T.; Menendez, A. D.; Damashek, J.; Francis, C. A.; Casciotti, K. L.

    2014-12-01

    Nitrification is the process of converting ammonium (NH­­4+) into nitrate (NO3-), and is a crucial step in removing nitrogen (N) from aquatic ecosystems. This process is governed by ammonia-oxidizing bacteria (AOB) and archaea (AOA) that utilize the ammonia monooxygenase gene (amoA). Studying the rates of nitrification and the abundances of ammonia-oxidizing microorganisms in south San Francisco Bay's Artesian Slough, which receives treated effluent from the massive San Jose-Santa Clara Regional Wastewater Facility, are important for understanding the cycling of nutrients in this small but complex estuary. Wastewater inputs can have negative environmental impacts, such as the release of nitrous oxide, a byproduct of nitrification and a powerful greenhouse gas. Nutrient inputs can also increase productivity and sometimes lead to oxygen depletion. Assessing the relative abundance and diversity of AOA and AOB, along with measuring nitrification rates gives vital information about the biology and biogeochemistry of this important N-cycling process. To calculate nitrification rates, water samples were spiked with 15N-labeled ammonium and incubated in triplicate for 24 hours. Four time-points were extracted across the incubation and the "denitrifier" method was used to measure the isotopic ratio of nitrate in the samples over time. In order to determine relative ratios of AOB to AOA, DNA was extracted from water samples and used in clade-specific amoA PCR assays. Nitrification rates were detectable in all locations sampled and were higher than in other regions of the bay, as were concentrations of nitrate and ammonium. Rates were highest in the regions of Artesian Slough most directly affected by wastewater effluent. AOB vastly outnumbered AOA, which is consistent with other studies showing that AOB prefer high nutrient environments. AOB diversity includes clades of Nitrosospira and Nitrosomonas prevalent in estuarine settings. Many of the sequenced genes are related

  18. Long-term impacts due to sediment supply changes towards the San Francisco Bay-Delta system

    Science.gov (United States)

    Achete, F.; Van der Wegen, M. V.; Jaffe, B. E.

    2012-12-01

    The Sacramento-San Joaquin Delta and Watershed is the main source of fresh water and sediment to San Francisco Bay. Mid 19th century hydraulic mining in the catchment caused an excessive supply of sediment. After mining activities stopped, in the first part of the 20th century several hydraulic structures were built deviating fresh water and trapping sediment upstream. The main purpose of most of these structures is water storage for irrigation and/or water supply Wright and Schoellhamer (2004) show that from 1957 to 2001 the sediment load carried to San Francisco Bay has decreased by about one half. The lack of sediments may lead to a different erosion/deposition pattern in the Bay-Delta system causing problems like mud flat erosion, shift in navigation channel, land subsidence and changing habitat for endemic species. The objective of this work is to identify and quantify morphological shifts in the Bay-Delta system due to variation in fresh water and sediment supply. In this study, we couple the Delta and Bay in a unique model network (the Delta-Bay model). This coupling allows tracking of sediment from Sacramento via the Delta and Bay and through the Golden Gate, making it possible to identify erosion and deposition areas. The numerical model applied is an unstructured, process-based model (D-Flow Flexible Mesh developed by Deltares). It simulates the hydrodynamics and morphodynamics of the area on a detailed, 64000-node mesh (10-200m mesh length scale) on a timescale of minutes. The morphological impact is assessed for multiple scenarios with different input of sediment and fresh water. A statistical analysis is performed to account for uncertainty of model parameters and climate change impacts. The fresh water discharge already has a strong natural seasonal and inter-annual variation. The human impact by foreseen different water pumping strategies due to the peripheral canal will be considered. Jaffe et al. (2007) has shown that substantial morphological

  19. A Place to Call Home: A Synthesis of Delta Smelt Habitat in the Upper San Francisco Estuary

    Directory of Open Access Journals (Sweden)

    Ted Sommer

    2013-06-01

    Full Text Available We used a combination of published literature and field survey data to synthesize the available information about habitat use by delta smelt Hypomesus transpacificus, a declining native species in the San Francisco Estuary. Delta smelt habitat ranges from San Pablo and Suisun bays to their freshwater tributaries, including the Sacramento and San Joaquin rivers. In recent years, substantial numbers of delta smelt have colonized habitat in Liberty Island, a north Delta area that flooded in 1997. The species has a more upstream distribution during spawning as opposed to juvenile rearing periods. Post-larvae and juveniles tend to have a more downstream distribution during wetter years. Delta smelt are most common in low-salinity habitat (<6 psu with high turbidities (>12 NTU and moderate temperatures (7 °C to 25 °C. They do not appear to have strong substrate preferences, but sandy shoals are important for spawning in other osmerids. The evidence to date suggests that they generally require at least some tidal flow in their habitats. Delta smelt also occur in a wide range of channel sizes, although they seem to be rarer in small channels (<15 m wide. Nonetheless, there is some evidence that open water adjacent to habitats with long water-residence times (e.g. tidal marsh, shoal, low-order channels may be favorable. Other desirable features of delta smelt habitat include high calanoid copepod densities and low levels of submerged aquatic vegetation (SAV and the toxic algae Microcystis. Although enough is known to plan for large-scale pilot habitat projects, these efforts are vulnerable to several factors, most notably climate change, which will change salinity regimes and increase the occurrence of lethal temperatures. We recommend restoration of multiple geographical regions and habitats coupled with extensive monitoring and adaptive management. An overall emphasis on ecosystem processes rather than specific habitat features is also likely to be

  20. A Tree-Ring Reconstruction of the Salinity Gradient in the Northern Estuary of San Francisco Bay

    Directory of Open Access Journals (Sweden)

    David W. Stahle

    2011-04-01

    Full Text Available Blue oak tree-ring chronologies correlate highly with winter–spring precipitation totals over California, with Sacramento and San Joaquin river stream flow, and with seasonal variations in the salinity gradient in San Francisco Bay. The convergence of fresh and saline currents can influence turbidity, sediment accumulation, and biological productivity in the estuary. Three selected blue oak chronologies were used to develop a 625-year-long reconstruction of the seasonal salinity gradient, or low salinity zone (LSZ, which provides a unique perspective on the interannual-to-decadal variability of this important estuarine habitat indicator. The reconstruction was calibrated with instrumental LSZ data for the winter–spring season, and explains 73% of the variance in the February–June position of the LSZ from 1956 to 2003. Because this calibration period post-dates the sweeping changes that have occurred to land cover, channel morphology, and natural streamflow regimes in California, the reconstruction provides an idealized estimate for how the LSZ might have fluctuated under the seasonal precipitation variations of the past 625 years, given the modern geometry and bathymetry of the estuary and land cover across the drainage basin. The February–June season integrates precipitation and runoff variability during the cool season, and does not extend into the late-summer dry season when LSZ extremes can negatively affect Sacramento–San Joaquin Delta (Delta agriculture and some aquatic organisms. However, there is such strong inter-seasonal persistence in the instrumental LSZ data that precipitation totals during the cool season can strongly pre-condition LSZ position in late summer. The 625-year-long reconstruction indicates strong interannual and decadal variability, the frequent recurrence of consecutive 2-year LSZ maxima and minima, large-scale ocean atmospheric forcing, and an interesting asymmetrical influence of warm El Ni

  1. Diurnal and Intra-Annual Variations in Greenhouse Gases at Fixed Sites in the San Francisco Bay Area

    Science.gov (United States)

    Newman, S.; Guha, A.; Martien, P. T.; Bower, J.; Perkins, I.; Randall, S.; Young, A.; Stevenson, E.; Hilken, H.

    2017-12-01

    The Bay Area Air Quality Management District, the San Francisco Bay Area's air quality regulatory agency, has set a goal to reduce the region's greenhouse gas (GHG) emissions to 80% below 1990 levels by 2050, consistent with the State of California's climate goals. Recently, the Air District's governing board adopted a 2017 Clean Air Plan which lays out the agency's vision and includes actions to put the region on a path towards achieving the 2050 goal while also reducing air pollution and related health impacts. The Plan includes GHG rule-making efforts, policy initiatives, local government partnerships, outreach, grants, and incentives, encompassing over 250 specific implementation actions across all economic sectors to effect ambitious emission reductions in the region. To track trends in atmospheric observations of GHGs and associated species and monitor changes in regional emission patterns, the Air District has established a fixed site network (CO2, CH4, CO) of one generally upwind site (Bodega Bay - on the coast north of Marin County) and three receptor sites (Bethel Island - east of the major refineries, in the Sacramento River Delta; Livermore - east of the bulk of the East Bay cities; and San Martin - south of the major city of San Jose). Having collected over a year of data for each of the fixed sites, the Air District is now investigating spatial and temporal variations in GHG emissions. Concentrating on variations in diurnal cycles, we see the commonly observed pattern of seasonal changes in diurnal amplitude at all sites, with larger variations during the winter than the summer, consistent with seasonally varying daily changes in planetary boundary layer heights. Investigations explore the weekday/weekend effect on the diurnal patterns and the effect of seasonal wind direction changes on the intra-annual variations of the local enhancements. The Air District is beginning to investigate the ways in which the fixed site network reflects the dominant

  2. Riders on the storm: selective tidal movements facilitate the spawning migration of threatened delta smelt in the San Francisco Estuary

    Science.gov (United States)

    Bennett, W.A.; Burau, Jon R.

    2015-01-01

    Migration strategies in estuarine fishes typically include behavioral adaptations for reducing energetic costs and mortality during travel to optimize reproductive success. The influence of tidal currents and water turbidity on individual movement behavior were investigated during the spawning migration of the threatened delta smelt, Hypomesus transpacificus, in the northern San Francisco Estuary, California, USA. Water current velocities and turbidity levels were measured concurrently with delta smelt occurrence at sites in the lower Sacramento River and San Joaquin River as turbidity increased due to first-flush winter rainstorms in January and December 2010. The presence/absence of fish at the shoal-channel interface and near the shoreline was quantified hourly over complete tidal cycles. Delta smelt were caught consistently at the shoal-channel interface during flood tides and near the shoreline during ebb tides in the turbid Sacramento River, but were rare in the clearer San Joaquin River. The apparent selective tidal movements by delta smelt would facilitate either maintaining position or moving upriver on flood tides, and minimizing advection down-estuary on ebb tides. These movements also may reflect responses to lateral gradients in water turbidity created by temporal lags in tidal velocities between the near-shore and mid-channel habitats. This migration strategy can minimize the energy spent swimming against strong river and tidal currents, as well as predation risks by remaining in turbid water. Selection pressure on individuals to remain in turbid water may underlie population-level observations suggesting that turbidity is a key habitat feature and cue initiating the delta smelt spawning migration.

  3. Facing the great disaster : How the men and women of the U.S. Geological Survey responded to the 1906 "San Francisco Earthquake"

    Science.gov (United States)

    Colvard, Elizabeth M.; Rogers, James

    2006-01-01

    It was the most devastating earthquake in California’s history. At 5:12 a.m. on April 18, 1906, the ground under the San Francisco Bay Area shook violently for more than 40 seconds. The magnitude 7.8 earthquake created a rupture along nearly 300 miles of the San Andreas Fault and was felt from southern Oregon to Los Angeles. Because the earthquake’s epicenter was just offshore from San Francisco, the impact on that city was catastrophic. Fragments of broken houses and buildings tumbled into the streets. The pipeline carrying water into the city was severed; fires triggered by broken gas mains raged out of control for 3 days. An area of almost 5 square miles in the heart of the city was destroyed by shaking and fire, and earthquake damage was widespread elsewhere. At least 3,000 people were killed, and 225,000 were left homeless. Drinking water, food, and supplies quickly became scarce.In 1906, the only permanent U.S. Geological Survey (USGS) office in California was the Pacific Division topographic mapping office in Sacramento, 70 miles up the Sacramento River from San Francisco Bay. The office had been established just 3 years earlier and was the only USGS office ever created for the sole function of topographic mapping. At the time of the earthquake, many USGS topographers were in Sacramento preparing for a summer of field work.Although moderate shaking was felt in Sacramento, then a town of about 30,000 people, detailed information about the earthquake was slow to reach the residents there. USGS topographic engineer George R. Davis, not knowing the full extent of the damage, was fearful that his 62-year-old father Edward Davis in San Francisco was caught up in the devastation. George therefore left Sacramento on the first train bound for the San Francisco Bay area. “He was very worried. The phones were down and he wasn’t sure whether or not the hotel his father was living in was damaged,” said George Davis’s daughter Anna (Davis) Rogers, then an

  4. Simulation of ridesourcing using agent-based demand and supply regional models : potential market demand for first-mile transit travel and reduction in vehicle miles traveled in the San Francisco Bay Area.

    Science.gov (United States)

    2016-01-01

    In this study, we use existing modeling tools and data from the San Francisco Bay Area : (California) to understand the potential market demand for a first mile transit access service : and possible reductions in vehicle miles traveled (VMT) (a...

  5. Regional and Large-Scale Climate Influences on Tree-Ring Reconstructed Null Zone Position in San Francisco Bay

    Science.gov (United States)

    Stahle, D.; Griffin, D.; Cleaveland, M.; Fye, F.; Meko, D.; Cayan, D.; Dettinger, M.; Redmond, K.

    2007-05-01

    A new network of 36 moisture sensitive tree-ring chronologies has been developed in and near the drainage basins of the Sacramento and San Joaquin Rivers. The network is based entirely on blue oak (Quercus douglasii), which is a California endemic found from the lower forest border up into the mixed conifer zone in the Coast Ranges, Sierra Nevada, and Cascades. These blue oak tree-ring chronologies are highly correlated with winter-spring precipitation totals, Sacramento and San Joaquin streamflow, and with seasonal variations in salinity and null zone position in San Francisco Bay. Null zone is the non-tidal bottom water location where density-driven salinity and river-driven freshwater currents balance (zero flow). It is the area of highest turbidity, water residence time, sediment accumulation, and net primary productivity in the estuary. Null zone position is measured by the distance from the Golden Gate of the 2 per mil bottom water isohaline and is primarily controlled by discharge from the Sacramento and San Joaquin Rivers (and ultimately by winter-spring precipitation). The location of the null zone is an estuarine habitat indicator, a policy variable used for ecosystem management, and can have a major impact on biological resources in the San Francisco estuary. Precipitation-sensitive blue oak chronologies can be used to estimate null zone position based on the strong biogeophysical interaction among terrestrial, aquatic, and estuarine ecosystems, orchestrated by precipitation. The null zone reconstruction is 626-years long and provides a unique long term perspective on the interannual to decadal variability of this important estuarine habitat indicator. Consecutive two-year droughts (or longer) allow the null zone to shrink into the confined upper reaches of Suisun Bay, causing a dramatic reduction in phytoplankton production and favoring colonization of the estuary by marine biota. The reconstruction indicates an approximate 10 year recurrence interval

  6. Memory and Nostalgia in Youth Music Cultures: Finding the Vibe in the San Francisco Bay Area Rave Scene, 2002-2004

    Directory of Open Access Journals (Sweden)

    Eileen M Wu

    2010-07-01

    Full Text Available In the wake of the major commercial success of rave scenes in the San Francisco Bay Area, accompanied by an increasing crackdown on venues and promoters in the electronic dance music scene, this article follows the “death” of a rave scene and looks at some of the ways young people imagined and engaged with rave culture during that time. Looking specifically at how young people utilized remembrances and nostalgia to imbue their experiences with social meaning, the author provides a tentative case study on youth cultural formation in the late modern era. The article draws upon fieldwork and interviews conducted in the San Francisco Bay Area between 2002-2004.

  7. Mountain Lake, Presidio National Park, San Francisco: Paleoenvironment, heavy metal contamination, sedimentary record rescue, remediation, and public outreach

    Science.gov (United States)

    Myrbo, A.; Rodysill, J. R.; Jones, K.; Reidy, L. M.

    2014-12-01

    Sediment cores from Mountain Lake, a small natural lake in Presidio National Park, San Francisco, CA, provide a record of Bay Area environmental change spanning the past 2000 years, and of unusually high heavy metal contamination in the last century (Reidy 2001). In 2013, partial dredging of the lake removed the upper two meters of lake sediment as part of a remediation effort. Prior to dredging, long and short cores spatially covering the lake and representing deep and shallow environments were recovered from the lake to preserve the paleoenvironmental record of one of the only natural lakes on the San Francisco Peninsula. The cores are curated at LacCore and are available for research by the scientific community. Mountain Lake formed in an interdunal depression and was shallow and fluctuating in its first few hundred years. Lake level rise and inundation of a larger area was followed by lowstands under drier conditions around 550-700 and 1300 CE. Nonnative taxa and cultivars appeared at the time of Spanish settlement in the late 18th century, and the lake underwent eutrophication due to livestock pasturing. U.S. Army landscaping introduced trees to the watershed in the late 19th century. The upper ~1m of sediments document unusually high heavy metal contamination, especially for lead and zinc, caused by the construction and heavy use of Highway 1 on the lake shore. Lead levels peak in 1975 and decline towards the surface, reflecting the history of leaded gasoline use in California. Zinc is derived mainly from automobile tires, and follows a pattern similar to that of lead, but continues to increase towards the surface. Ongoing research includes additional radiocarbon dating and detailed lithological analysis to form the basis of lake-level reconstruction and archeological investigations. Because the Presidio archaeological record does not record human habitation in the area until approximately 1300 years before present, the core analysis also has the potential to

  8. Physicians' communication with patients about adherence to HIV medication in San Francisco and Copenhagen: a qualitative study using Grounded Theory

    Directory of Open Access Journals (Sweden)

    Rubow Cecilie

    2006-12-01

    Full Text Available Abstract Background Poor adherence is the main barrier to the effectiveness of HIV medication. The objective of this study was to explore and conceptualize patterns and difficulties in physicians' work with patients' adherence to HIV medication. No previous studies on this subject have directly observed physicians' behavior. Methods This is a qualitative, cross-sectional study. We used a Grounded Theory approach to let the main issues in physicians' work with patients' adherence emerge without preconceiving the focus of the study. We included physicians from HIV clinics in San Francisco, U.S.A. as well as from Copenhagen, Denmark. Physicians were observed during their clinical work and subsequently interviewed with a semi-structured interview guide. Notes on observations and transcribed interviews were analyzed with NVivo software. Results We enrolled 16 physicians from San Francisco and 18 from Copenhagen. When we discovered that physicians and patients seldom discussed adherence issues in depth, we made adherence communication and its barriers the focus of the study. The main patterns in physicians' communication with patients about adherence were similar in both settings. An important barrier to in-depth adherence communication was that some physicians felt it was awkward to explore the possibility of non-adherence if there were no objective signs of treatment failure, because patients could feel "accused." To overcome this awkwardness, some physicians consciously tried to "de-shame" patients regarding non-adherence. However, a recurring theme was that physicians often suspected non-adherence even when patients did not admit to have missed any doses, and physicians had difficulties handling this low believability of patient statements. We here develop a simple four-step, three-factor model of physicians' adherence communication. The four steps are: deciding whether to ask about adherence or not, pre-questioning preparations, phrasing the

  9. Physicians' communication with patients about adherence to HIV medication in San Francisco and Copenhagen: a qualitative study using Grounded Theory.

    Science.gov (United States)

    Barfod, Toke S; Hecht, Frederick M; Rubow, Cecilie; Gerstoft, Jan

    2006-12-04

    Poor adherence is the main barrier to the effectiveness of HIV medication. The objective of this study was to explore and conceptualize patterns and difficulties in physicians' work with patients' adherence to HIV medication. No previous studies on this subject have directly observed physicians' behavior. This is a qualitative, cross-sectional study. We used a Grounded Theory approach to let the main issues in physicians' work with patients' adherence emerge without preconceiving the focus of the study. We included physicians from HIV clinics in San Francisco, U.S.A. as well as from Copenhagen, Denmark. Physicians were observed during their clinical work and subsequently interviewed with a semi-structured interview guide. Notes on observations and transcribed interviews were analyzed with NVivo software. We enrolled 16 physicians from San Francisco and 18 from Copenhagen. When we discovered that physicians and patients seldom discussed adherence issues in depth, we made adherence communication and its barriers the focus of the study. The main patterns in physicians' communication with patients about adherence were similar in both settings. An important barrier to in-depth adherence communication was that some physicians felt it was awkward to explore the possibility of non-adherence if there were no objective signs of treatment failure, because patients could feel "accused." To overcome this awkwardness, some physicians consciously tried to "de-shame" patients regarding non-adherence. However, a recurring theme was that physicians often suspected non-adherence even when patients did not admit to have missed any doses, and physicians had difficulties handling this low believability of patient statements. We here develop a simple four-step, three-factor model of physicians' adherence communication. The four steps are: deciding whether to ask about adherence or not, pre-questioning preparations, phrasing the question, and responding to the patient's answer. The three

  10. Macroinvertebrate Prey Availability and Fish Diet Selectivity in Relation to Environmental Variables in Natural and Restoring North San Francisco Bay Tidal Marsh Channels

    OpenAIRE

    Emily R. Howe; Charles A. Simenstad; Jason D. Toft; Jeffrey R. Cordell; Stephen M. Bollens

    2014-01-01

    Tidal marsh wetlands provide important foraging habitat for a variety of estuarine fishes. Prey organisms include benthic–epibenthic macroinvertebrates, neustonic arthropods, and zooplankton. Little is known about the abundance and distribution of interior marsh macroinvertebrate communities in the San Francisco Estuary (estuary). We describe seasonal, regional, and site variation in the composition and abundance of neuston and benthic–epibenthic macroinvertebrates that inhabit tidal marsh ch...

  11. Estimating juvenile Chinook salmon (Oncorhynchus tshawytscha) abundance from beach seine data collected in the Sacramento–San Joaquin Delta and San Francisco Bay, California

    Science.gov (United States)

    Perry, Russell W.; Kirsch, Joseph E.; Hendrix, A. Noble

    2016-06-17

    Resource managers rely on abundance or density metrics derived from beach seine surveys to make vital decisions that affect fish population dynamics and assemblage structure. However, abundance and density metrics may be biased by imperfect capture and lack of geographic closure during sampling. Currently, there is considerable uncertainty about the capture efficiency of juvenile Chinook salmon (Oncorhynchus tshawytscha) by beach seines. Heterogeneity in capture can occur through unrealistic assumptions of closure and from variation in the probability of capture caused by environmental conditions. We evaluated the assumptions of closure and the influence of environmental conditions on capture efficiency and abundance estimates of Chinook salmon from beach seining within the Sacramento–San Joaquin Delta and the San Francisco Bay. Beach seine capture efficiency was measured using a stratified random sampling design combined with open and closed replicate depletion sampling. A total of 56 samples were collected during the spring of 2014. To assess variability in capture probability and the absolute abundance of juvenile Chinook salmon, beach seine capture efficiency data were fitted to the paired depletion design using modified N-mixture models. These models allowed us to explicitly test the closure assumption and estimate environmental effects on the probability of capture. We determined that our updated method allowing for lack of closure between depletion samples drastically outperformed traditional data analysis that assumes closure among replicate samples. The best-fit model (lowest-valued Akaike Information Criterion model) included the probability of fish being available for capture (relaxed closure assumption), capture probability modeled as a function of water velocity and percent coverage of fine sediment, and abundance modeled as a function of sample area, temperature, and water velocity. Given that beach seining is a ubiquitous sampling technique for

  12. Dosimetry in occupational exposure workers of the medical institutes of the University San Francisco Xavier de Chuquisaca; Dosimetria en TOEs de los institutos medicos de la Universidad San Francisco Xavier de Chuquisaca

    Energy Technology Data Exchange (ETDEWEB)

    Zambrana Z, A. J.; Castro S, O.; Huanca S, E.; Torrez C, M. [Universidad Mayor, Real y Pontificia de San Francisco Xavier de Chuquisaca, Instituto de Medicina Nuclear de Sucre, Plaza Libertad No. 1, Sucre (Bolivia, Plurinational State of); Villca Q, I., E-mail: nuclear_sre@entelnet.bo [Universidad Mayor, Real y Pontificia de San Francisco Xavier de Chuquisaca, Instituto Nacional de Cancerologia Dr. Jose Cupertino Arteaga, Plaza Libertad No. 1, Sucre (Bolivia, Plurinational State of)

    2014-08-15

    In this work is made a retrospective analysis of the record, of the dosimetric control readings processed by the Dosimetry Laboratory of the Instituto Boliviano de Ciencia y Tecnologia Nuclear, as regulator entity at national level for Occupational Exposed Workers (OEWs) to ionizing radiations, of the Medical Institutes of the Universidad Mayor, Real y Pontificia de San Francisco Xavier de Chuquisaca, by a period of 10 and 15 years. The results showed that in the Nuclear Medicine Institute of Sucre, the Accumulated Occupational Exposure of a total of 393 readings of 15 OEWs was of 20.4 mSv, identifying as maximum value 10.2 mSv, in the official that develops the Radio-pharmacy activities (elution, fractionation, preparation and management). In the Instituto Nacional de Cancerologia Dr. Jose Cupertino Arteaga the dosimetric background registered an Accumulated Occupational Exposure of a total of 1319 readings of 50 OEWs of 309.69 mSv, with a maximum value of 62.30 mSv, corresponding to the worker of the technical area (maintenance, adjustment and calibration). Comparison that allows to infer that the difference is due mainly to the radio-active source type {sup 99m}Tc Vs {sup 60}Co utilized in these health centers. (Author)

  13. Guidelines for sustainable tourism planning in the township of San Francisco de Asis (Acandi Municipality, Choco, Colombia); Lineamientos para la planeacion del turismo sostenible en el corregimiento de San Francisco de Asis (Municipio de Acandi, Choco, Colombia).

    Energy Technology Data Exchange (ETDEWEB)

    Roldan Carvajal, Carlos Daniel

    2012-07-01

    This paper presents important management guidelines for conducting a tourism planning process in the township of San Francisco de Asis, which were developed from the conceptual notion of sustainable tourism and participation of local people. This case considered the participatory research method, used ethnography techniques and implemented shops with the community. As a main result proposed the consolidation of four components, socio- political, socio- cultural, social- ecological and socio- economic; that must be managed in an integrated fashion to achieve real sustainable tourism in this territory. In the first component outlines an participatory process that must take place between the various stake holders; in the second considered strengthen the social tissue and valuing cultural traditions to adequately integrate tourism activities; the third proposes an integrated environmental conservation in the whole territory and as an obligation of all stake holders, including to tourists; finally, in the fourth component, recommend the creation of more opportunities and general welfare for the entire local population in order to prevent the growth of tourism segregated. As a general conclusion will projected that the implementation of these guidelines permitted advance, from the practical, in the development of a truly sustainable tourism that help improve the living conditions of local people and conserve valuable natural and cultural resources that exist in this territory.

  14. Deep nirS amplicon sequencing of San Francisco Bay sediments enables prediction of geography and environmental conditions from denitrifying community composition.

    Science.gov (United States)

    Lee, Jessica A; Francis, Christopher A

    2017-12-01

    Denitrification is a dominant nitrogen loss process in the sediments of San Francisco Bay. In this study, we sought to understand the ecology of denitrifying bacteria by using next-generation sequencing (NGS) to survey the diversity of a denitrification functional gene, nirS (encoding cytchrome-cd 1 nitrite reductase), along the salinity gradient of San Francisco Bay over the course of a year. We compared our dataset to a library of nirS sequences obtained previously from the same samples by standard PCR cloning and Sanger sequencing, and showed that both methods similarly demonstrated geography, salinity and, to a lesser extent, nitrogen, to be strong determinants of community composition. Furthermore, the depth afforded by NGS enabled novel techniques for measuring the association between environment and community composition. We used Random Forests modelling to demonstrate that the site and salinity of a sample could be predicted from its nirS sequences, and to identify indicator taxa associated with those environmental characteristics. This work contributes significantly to our understanding of the distribution and dynamics of denitrifying communities in San Francisco Bay, and provides valuable tools for the further study of this key N-cycling guild in all estuarine systems. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  15. Trends and habitat associations of waterbirds using the South Bay Salt Pond Restoration Project, San Francisco Bay, California

    Science.gov (United States)

    De La Cruz, Susan E. W.; Smith, Lacy M.; Moskal, Stacy M.; Strong, Cheryl; Krause, John; Wang, Yiwei; Takekawa, John Y.

    2018-04-02

    Executive SummaryThe aim of the South Bay Salt Pond Restoration Project (hereinafter “Project”) is to restore 50–90 percent of former salt evaporation ponds to tidal marsh in San Francisco Bay (SFB). However, hundreds of thousands of waterbirds use these ponds over winter and during fall and spring migration. To ensure that existing waterbird populations are supported while tidal marsh is restored in the Project area, managers plan to enhance the habitat suitability of ponds by adding islands and berms to change pond topography, manipulating water salinity and depth, and selecting appropriate ponds to maintain for birds. To help inform these actions, we used 13 years of monthly (October–April) bird abundance data from Project ponds to (1) assess trends in waterbird abundance since the inception of the Project, and (2) evaluate which pond habitat characteristics were associated with highest abundances of different avian guilds and species. For comparison, we also evaluated waterbird abundance trends in active salt production ponds using 10 years of monthly survey data.We assessed bird guild and species abundance trends through time, and created separate trend curves for Project and salt production ponds using data from every pond that was counted in a year. We divided abundance data into three seasons—fall (October–November), winter (December–February), and spring (March–April). We used the resulting curves to assess which periods had the highest bird abundance and to identify increasing or decreasing trends for each guild and species.

  16. Integrating terrestrial LiDAR and stereo photogrammetry to map the Tolay lakebed in northern San Francisco Bay

    Science.gov (United States)

    Woo, Isa; Storesund,; Takekawa, John Y.; Gardiner, Rachel J.; Ehret,

    2009-01-01

    The Tolay Creek Watershed drains approximately 3,520 ha along the northern edge of San Francisco Bay. Surrounded by a mosaic of open space conservation easements and public wildlife areas, it is one of the only watersheds in this urbanized estuary that is protected from its headwaters to the bay. Tolay Lake is a seasonal, spring-fed lake found in the upper watershed that historically extended over 120 ha. Although the lakebed was farmed since the early 1860s, the majority of the lakebed was recently acquired by the Sonoma County Regional Parks Department to restore its natural habitat values. As part of the restoration planning process, we produced a digital elevation model (DEM) of the historic extent of Tolay Lake by integrating terrestrial LiDAR (light detection and ranging) and stereo photogrammetry datasets, and real-time kinematic (RTK) global positioning system (GPS) surveys. We integrated the data, generated a DEM of the lakebed and upland areas, and analyzed errors. The accuracy of the composite DEM was verified using spot elevations obtained from the RTK GPS. Thus, we found that by combining photogrammetry, terrestrial LiDAR, and RTK GPS, we created an accurate baseline elevation map to use in watershed restoration planning and design.

  17. Distribution of biologic, anthropogenic, and volcanic constituents as a proxy for sediment transport in the San Francisco Bay Coastal System

    Science.gov (United States)

    McGann, Mary; Erikson, Li H.; Wan, Elmira; Powell, Charles; Maddocks, Rosalie F.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    Although conventional sediment parameters (mean grain size, sorting, and skewness) and provenance have typically been used to infer sediment transport pathways, most freshwater, brackish, and marine environments are also characterized by abundant sediment constituents of biological, and possibly anthropogenic and volcanic, origin that can provide additional insight into local sedimentary processes. The biota will be spatially distributed according to its response to environmental parameters such as water temperature, salinity, dissolved oxygen, organic carbon content, grain size, and intensity of currents and tidal flow, whereas the presence of anthropogenic and volcanic constituents will reflect proximity to source areas and whether they are fluvially- or aerially-transported. Because each of these constituents have a unique environmental signature, they are a more precise proxy for that source area than the conventional sedimentary process indicators. This San Francisco Bay Coastal System study demonstrates that by applying a multi-proxy approach, the primary sites of sediment transport can be identified. Many of these sites are far from where the constituents originated, showing that sediment transport is widespread in the region. Although not often used, identifying and interpreting the distribution of naturally-occurring and allochthonous biologic, anthropogenic, and volcanic sediment constituents is a powerful tool to aid in the investigation of sediment transport pathways in other coastal systems.

  18. Guidelines for sustainable tourism planning in the township of San Francisco de Asis (Acandi Municipality, Choco, Colombia)

    International Nuclear Information System (INIS)

    Roldan Carvajal, Carlos Daniel

    2012-01-01

    This paper presents important management guidelines for conducting a tourism planning process in the township of San Francisco de Asis, which were developed from the conceptual notion of sustainable tourism and participation of local people. This case considered the participatory research method, used ethnography techniques and implemented shops with the community. As a main result proposed the consolidation of four components, socio- political, socio- cultural, social- ecological and socio- economic; that must be managed in an integrated fashion to achieve real sustainable tourism in this territory. In the first component outlines an participatory process that must take place between the various stake holders; in the second considered strengthen the social tissue and valuing cultural traditions to adequately integrate tourism activities; the third proposes an integrated environmental conservation in the whole territory and as an obligation of all stake holders, including to tourists; finally, in the fourth component, recommend the creation of more opportunities and general welfare for the entire local population in order to prevent the growth of tourism segregated. As a general conclusion will projected that the implementation of these guidelines permitted advance, from the practical, in the development of a truly sustainable tourism that help improve the living conditions of local people and conserve valuable natural and cultural resources that exist in this territory.

  19. Impact of a Structural Intervention to Address Alcohol Use Among Gay Bar Patrons in San Francisco: The PACE Study.

    Science.gov (United States)

    Charlebois, Edwin D; Plenty, Albert H; Lin, Jessica; Ayala, Alicia; Hecht, Jennifer

    2017-11-01

    We evaluated the impact on alcohol intake and blood alcohol concentration (BAC) of a multi-level structural intervention to increase the availability of free water, coupled with messaging on pacing alcohol intake and normative feedback of blood alcohol concentration in a convenience sample of gay bars in San Francisco. Participants (n = 1,293) were recruited among exiting patrons of four gay bars (two intervention bars and two control bars). Participants were surveyed on alcohol intake and BAC was measured by breathalyzer. Prior to the intervention there were no significant differences in baseline alcohol measures between intervention and control bars. Post-intervention there were significant differences on objective and subjective measures of alcohol consumption: 30% of intervention bar participants had BAC% levels over the legal driving limit (0.08%) compared to 43% of control bar participants, p < 0.0001 and 78% of intervention bar participants were above the AUDIT-C cut-off for hazardous drinking compared to 87% in control bars, p < 0.001.

  20. Hepatitis B and liver cancer knowledge and preventive practices among Asian Americans in the San Francisco Bay Area, California.

    Science.gov (United States)

    Wu, Charlotte A; Lin, Steven Y; So, Samuel K; Chang, Ellen T

    2007-01-01

    Chronic hepatitis B virus (HBV) infection causes liver cancer and disproportionately affects the Asian community in the U.S. In order to advance HBV and liver cancer awareness and prevention, it is important to identify existing gaps in knowledge and preventive practices among Asian Americans. Therefore, the authors administered a written questionnaire to 199 adults in the Asian-American community of the San Francisco Bay Area, California. Although the majority of adults had at least a college education, knowledge regarding HBV transmission, prevention, symptoms, risks, and occurrence was low. Fewer than 60% reported having been tested for HBV, only 31% reported having been vaccinated against HBV, and only 44% reported having had their children vaccinated. Asians, especially those born in China or Southeast Asia, had significantly poorer knowledge regarding HBV and liver cancer than non-Asians. Those with higher knowledge levels were significantly more likely to have been tested for HBV and to have had their children vaccinated. Younger adults, women, Caucasians, more highly educated individuals, those not born in China or Hong Kong, and those with a personal or family history of liver disease were more likely to have taken preventive action against HBV. Our results suggest that HBV and liver cancer knowledge among Asian Americans, especially Chinese Americans, is poor, and that better knowledge is associated with increased preventive practices. Thus, there is a need for increased HBV education and improved community-based interventions to prevent HBV-related liver disease in the high-risk Asian-American community.

  1. Dosimetry in occupational exposure workers of the medical institutes of the University San Francisco Xavier de Chuquisaca

    International Nuclear Information System (INIS)

    Zambrana Z, A. J.; Castro S, O.; Huanca S, E.; Torrez C, M.; Villca Q, I.

    2014-08-01

    In this work is made a retrospective analysis of the record, of the dosimetric control readings processed by the Dosimetry Laboratory of the Instituto Boliviano de Ciencia y Tecnologia Nuclear, as regulator entity at national level for Occupational Exposed Workers (OEWs) to ionizing radiations, of the Medical Institutes of the Universidad Mayor, Real y Pontificia de San Francisco Xavier de Chuquisaca, by a period of 10 and 15 years. The results showed that in the Nuclear Medicine Institute of Sucre, the Accumulated Occupational Exposure of a total of 393 readings of 15 OEWs was of 20.4 mSv, identifying as maximum value 10.2 mSv, in the official that develops the Radio-pharmacy activities (elution, fractionation, preparation and management). In the Instituto Nacional de Cancerologia Dr. Jose Cupertino Arteaga the dosimetric background registered an Accumulated Occupational Exposure of a total of 1319 readings of 50 OEWs of 309.69 mSv, with a maximum value of 62.30 mSv, corresponding to the worker of the technical area (maintenance, adjustment and calibration). Comparison that allows to infer that the difference is due mainly to the radio-active source type 99m Tc Vs 60 Co utilized in these health centers. (Author)

  2. Associations between depressive syndromes and HIV risk behaviors among San Francisco men who have sex with men.

    Science.gov (United States)

    Chen, Yea-Hung; Raymond, Henry Fisher

    2017-12-01

    HIV prevention plans for men who have sex with men (MSM) are often multifaceted. They involve reduction of sexual risk behaviors, such as condomless intercourse, but also often include pharmaceutical approaches, such as early treatment of HIV-infected individuals with antiretroviral therapy (ART). Effectiveness is possibly threatened by individual-level factors, such as depression. In this study of 322 San Francisco MSM (240 HIV-uninfected individuals and 82 HIV-infected individuals, according to self-report), we examine associations between depressive syndromes and HIV risk behaviors (sexual risk behaviors and ART non-adherence). Our study failed to find evidence that depressive syndromes lead to increases in ART non-adherence (risk difference, RD: 27.9; 95% confidence interval, CI: -3.5, 59.3). However, the study does suggest an association between depressive syndromes and concurrence of non-adherence and potentially HIV-discordant condomless receptive anal intercourse (RD: 36.0; 95% CI: 5.2, 66.8). Among HIV-uninfected MSM, our study suggests negative associations between depressive syndromes and sexual risk behaviors. We recommend screening and treatment of depression among HIV-infected MSM.

  3. Sampling uncharted waters: Examining rearing habitat of larval Longfin Smelt (Spirinchus thaleichthys) in the upper San Francisco Estuary

    Science.gov (United States)

    Grimaldo, Lenny; Feyrer, Frederick; Burns, Jillian; Maniscalco, Donna

    2017-01-01

    The southern-most reproducing Longfin Smelt population occurs in the San Francisco Estuary, California, USA. Long-term monitoring of estuarine habitat for this species has generally only considered deep channels, with little known of the role shallow waters play in supporting their early life stage. To address the need for focused research on shallow-water habitat, a targeted study of Longfin Smelt larvae in littoral habitat was conducted to identify potential rearing habitats during 2013 and 2014. Our study objectives were to (1) determine if larval densities vary between littoral habitats (tidal slough vs. open-water shoal), (2) determine how larval densities in littoral habitats vary with physicochemical and biological attributes, (3) determine if larval densities vary between littoral habitats and long-term monitoring channel collections, and (4) determine what factors predict larval rearing distributions from the long-term monitoring channel collections. Larval densities did not vary between littoral habitats but they did vary between years. Water temperature, salinity, and chlorophyll a were found important in predicting larval densities in littoral habitats. Larval densities do not vary between littoral and channel surveys; however, the analysis based on channel data suggests that Longfin Smelt are hatching and rearing in a much broader region and under higher salinities (∼2–12 psu) than previously recognized. Results of this study indicate that conservation efforts should consider how freshwater flow, habitat, climate, and food webs interact as mechanisms that influence Longfin Smelt recruitment in estuarine environments.

  4. Monitoring Water Quality at Lake Merritt, Oakland, CA Following Improvements to the Tidal Channel to the San Francisco Bay

    Science.gov (United States)

    Bracho, H.; Martinez, J.; Johnson, M.; Turrey, A.; Avila, M.; Medina, S.; Rubio, E.; Ahumada, E.; Nguyen, S.; Guzman, Y.

    2014-12-01

    Elliot Ahumada, Esosa Oghogho, Samantha Nguyen, Humberto Bracho, Diego Quintero, Ashanti Johnson and Kevin Cuff Lake Merritt is a tidal lagoon in the center of Oakland, California, just east of Downtown. Water quality at Lake Merritt has been a major concern for community members and researchers for many years (Pham 200X). Results of past research lead to recommendations to lengthen a channel that connects Lake Merritt with the San Francisco Bay to improve water flow and quality. In 2012 the City of Oakland responded to these recommendations by initiating the creation of a 230-meter long channel. In conducting our research we use a water quality index that takes into account measurements of pH, temperature, water hardness (dissolved solids), ammonia, salinity, dissolved oxygen, and nitrate. Newly collected data is then compared with that collected by Pham using comparable parameters to assess the impact of recent changes at the Lake on its overall water quality. In addition, we measured the abundance of aquatic species at four different sites within the Lake. Preliminary results suggest that an increase in the abundance of fish and improved overall water quality have resulted from channel extension at Lake Merritt.

  5. A new seamless, high-resolution digital elevation model of the San Francisco Bay-Delta Estuary, California

    Science.gov (United States)

    Fregoso, Theresa A.; Wang, Rueen-Fang; Ateljevich, Eli; Jaffe, Bruce E.

    2017-06-14

    Climate change, sea-level rise, and human development have contributed to the changing geomorphology of the San Francisco Bay - Delta (Bay-Delta) Estuary system. The need to predict scenarios of change led to the development of a new seamless, high-resolution digital elevation model (DEM) of the Bay – Delta that can be used by modelers attempting to understand potential future changes to the estuary system. This report details the three phases of the creation of this DEM. The first phase took a bathymetric-only DEM created in 2005 by the U.S. Geological Survey (USGS), refined it with additional data, and identified areas that would benefit from new surveys. The second phase began a USGS collaboration with the California Department of Water Resources (DWR) that updated a 2012 DWR seamless bathymetric/topographic DEM of the Bay-Delta with input from the USGS and modifications to fit the specific needs of USGS modelers. The third phase took the work from phase 2 and expanded the coverage area in the north to include the Yolo Bypass up to the Fremont Weir, the Sacramento River up to Knights Landing, and the American River up to the Nimbus Dam, and added back in the elevations for interior islands. The constant evolution of the Bay-Delta will require continuous updates to the DEM of the Delta, and there still are areas with older data that would benefit from modern surveys. As a result, DWR plans to continue updating the DEM.

  6. Mortality among young injection drug users in San Francisco: a 10-year follow-up of the UFO study.

    Science.gov (United States)

    Evans, Jennifer L; Tsui, Judith I; Hahn, Judith A; Davidson, Peter J; Lum, Paula J; Page, Kimberly

    2012-02-15

    This study examined associations between mortality and demographic and risk characteristics among young injection drug users in San Francisco, California, and compared the mortality rate with that of the population. A total of 644 young (UFO ("U Find Out") Study, from November 1997 to December 2007. Using the National Death Index, the authors identified 38 deaths over 4,167 person-years of follow-up, yielding a mortality rate of 9.1 (95% confidence interval: 6.6, 12.5) per 1,000 person-years. This mortality rate was 10 times that of the general population. The leading causes of death were overdose (57.9%), self-inflicted injury (13.2%), trauma/accidents (10.5%), and injection drug user-related medical conditions (13.1%). Mortality incidence was significantly higher among those who reported injecting heroin most days in the past month (adjusted hazard ratio = 5.8, 95% confidence interval: 1.4, 24.3). The leading cause of death in this group was overdose, and primary use of heroin was the only significant risk factor for death observed in the study. These findings highlight the continued need for public health interventions that address the risk of overdose in this population in order to reduce premature deaths.

  7. Mercury contamination and effects on survival of American avocet and black-necked stilt chicks in San Francisco Bay.

    Science.gov (United States)

    Ackerman, Joshua T; Takekawa, John Y; Eagles-Smith, Collin A; Iverson, Samuel A

    2008-02-01

    We evaluated whether mercury influenced survival of free-ranging American avocet (Recurvirostra americana) and black-necked stilt (Himantopus mexicanus) chicks in San Francisco Bay, California. Using radio telemetry, we radio-marked 158 avocet and 79 stilt chicks at hatching and tracked them daily until their fate was determined. We did not find strong support for an influence of in ovo mercury exposure on chick survival, despite observing a wide range of mercury concentrations in chick down feathers at hatching (0.40-44.31 microg g(-1) fw). We estimated that chick survival rates were reduced by nest monitoring. In contrast to the telemetry results, we found that mercury concentrations in down feathers of dead chicks were higher than those in randomly-sampled live chicks of similar age. However, capture site was the most important variable influencing mercury concentrations, followed by year, species, and hatching date. Although laboratory studies have demonstrated negative effects of environmentally relevant mercury concentrations on chick survival, our results concur with the small number of previous field studies that have not been able to detect reduced survival in the wild.

  8. Storm surges and climate change implications for tidal marshes: Insight from the San Francisco Bay Estuary, California, USA

    Science.gov (United States)

    Thorne, Karen M.; Buffington, Kevin J.; Swanson, Kathleen; Takekawa, John Y.

    2013-01-01

    Tidal marshes are dynamic ecosystems, which are influenced by oceanic and freshwater processes and daily changes in sea level. Projected sea-level rise and changes in storm frequency and intensity will affect tidal marshes by altering suspended sediment supply, plant communities, and the inundation duration and depth of the marsh platform. The objective of this research was to evaluate if regional weather conditions resulting in low-pressure storms changed tidal conditions locally within three tidal marshes. We hypothesized that regional storms will increase sea level heights locally, resulting in increased inundation of the tidal marsh platform and plant communities. Using site-level measurements of elevation, plant communities, and water levels, we present results from two storm events in 2010 and 2011 from the San Francisco Bay Estuary (SFBE), California, USA. The January 2010 storm had the lowest recorded sea level pressure in the last 30 years for this region. During the storm episodes, the duration of tidal marsh inundation was 1.8 and 3.1 times greater than average for that time of year, respectively. At peak storm surges, over 65% in 2010 and 93% in 2011 of the plant community was under water. We also discuss the implications of these types of storms and projected sea-level rise on the structure and function of the tidal marshes and how that will impact the hydro-geomorphic processes and marsh biotic communities.

  9. Sociodemographic Factors Associated With Trans*female Youth's Access to Health Care in the San Francisco Bay Area.

    Science.gov (United States)

    Johns, Elizabeth A; Jin, Harry; Auerswald, Colette L; Wilson, Erin C

    2017-08-01

    Trans*female youth (TFY) are an underserved population at risk for a variety of poor health outcomes, in part related to barriers to accessing health and mental health care. We conducted a secondary analysis of data collected with 250 TFY aged 16-24 years in the San Francisco Bay Area from 2012 to 2014. Logistic regression was used to test associations between sociodemographic variables and barriers to gender identity-based medical and mental health care. Having a history of unstable housing was associated with significantly higher odds of problems accessing both medical care (odds ratio: 2.16, 95% confidence interval: 1.12-4.13) and mental health care due to gender identity (odds ratio 2.65, 95% confidence interval: 1.08-6.45). Conversely, identifying as genderqueer/genderfluid, Latina, or living in dependent housing was associated with access to either medical or mental health care. Interventions are needed to address housing and discrimination barring access to health care among TFY. Copyright © 2017 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  10. Ecosystem variability along the estuarine salinity gradient: Examples from long-term study of San Francisco Bay

    Science.gov (United States)

    Cloern, James E.; Jassby, Alan D.; Schraga, Tara; Kress, Erica S.; Martin, Charles A.

    2017-01-01

    The salinity gradient of estuaries plays a unique and fundamental role in structuring spatial patterns of physical properties, biota, and biogeochemical processes. We use variability along the salinity gradient of San Francisco Bay to illustrate some lessons about the diversity of spatial structures in estuaries and their variability over time. Spatial patterns of dissolved constituents (e.g., silicate) can be linear or nonlinear, depending on the relative importance of river-ocean mixing and internal sinks (diatom uptake). Particles have different spatial patterns because they accumulate in estuarine turbidity maxima formed by the combination of sinking and estuarine circulation. Some constituents have weak or no mean spatial structure along the salinity gradient, reflecting spatially distributed sources along the estuary (nitrate) or atmospheric exchanges that buffer spatial variability of ecosystem metabolism (dissolved oxygen). The density difference between freshwater and seawater establishes stratification in estuaries stronger than the thermal stratification of lakes and oceans. Stratification is strongest around the center of the salinity gradient and when river discharge is high. Spatial distributions of motile organisms are shaped by species-specific adaptations to different salinity ranges (shrimp) and by behavioral responses to environmental variability (northern anchovy). Estuarine spatial patterns change over time scales of events (intrusions of upwelled ocean water), seasons (river inflow), years (annual weather anomalies), and between eras separated by ecosystem disturbances (a species introduction). Each of these lessons is a piece in the puzzle of how estuarine ecosystems are structured and how they differ from the river and ocean ecosystems they bridge.

  11. Influence of anthropogenic alterations on geomorphic response to climate variations and change in San Francisco Bay-Delta and watershed

    Science.gov (United States)

    Florsheim, J.L.; Dettinger, M.D.

    2004-01-01

    Global warming and attendant sea-level rise may soon impact geomorphic processes in the Sacramento-San Joaquin River and San Francisco Bay Delta systems. During the past two centuries, dramatic anthropogenic changes in sediment supply and pervasive structural controls on rivers and floodplains have altered geomorphic responses to floods throughout a zone that extends upstream from tidally influenced areas to dams that regulate flow. Current geomorphic responses to floods differ from natural responses due to historical actions that concentrated the pre-disturbance multiple-channel and flood-basin system into single channels isolated by levees from increasingly developed floodplains and flood bypass channels, altered flow and sediment regimes, and caused subsidence of leveed Delta Islands. A review of historic and current geomorphic responses to floods illustrates the dominance of structural controls on geomorphic changes in the lowland part of the Sacramento-San Joaquin system. Current climate-change projections for CA suggest that the total volume of snowmelt runoff that may be shifted from spring and added to winter flows is roughly 5 maf/yr, similar to the volume currently available for flood storage in Sierra Nevadan reservoirs. Changes in timing of reservoir releases to accommodate these changes could add to either the magnitude or duration of winter flood peaks, each causing different geomorphic responses. Increased wintertime flows that accompany already large floods could increase overbank flood extent, erosion, and sedimentation, or alternatively increase the depth and strength of confined flows and increase the risk of levee failures. Runoff released from reservoirs as a relatively constant addition to winter baseflow would increase the duration of bankfull or possibly "levee-full" flows. This scenario could lead to bank and levee failure through increased saturation and seepage erosion. Projected sea level rise of 1-2 m would compound vulnerability of

  12. Ground-Water Quality Data in the San Francisco Bay Study Unit, 2007: Results from the California GAMA Program

    Science.gov (United States)

    Ray, Mary C.; Kulongoski, Justin T.; Belitz, Kenneth

    2009-01-01

    Ground-water quality in the approximately 620-square-mile San Francisco Bay study unit (SFBAY) was investigated from April through June 2007 as part of the Priority Basin project of the Ground-Water Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin project was developed in response to the Groundwater Quality Monitoring Act of 2001, and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). The study was designed to provide a spatially unbiased assessment of raw ground-water quality, as well as a statistically consistent basis for comparing water quality throughout California. Samples in SFBAY were collected from 79 wells in San Francisco, San Mateo, Santa Clara, Alameda, and Contra Costa Counties. Forty-three of the wells sampled were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells). Thirty-six wells were sampled to aid in evaluation of specific water-quality issues (understanding wells). The ground-water samples were analyzed for a large number of synthetic organic constituents (volatile organic compounds [VOC], pesticides and pesticide degradates, pharmaceutical compounds, and potential wastewater-indicator compounds), constituents of special interest (perchlorate and N-nitrosodimethylamine [NDMA]), naturally occurring inorganic constituents (nutrients, major and minor ions, trace elements, chloride and bromide isotopes, and uranium and strontium isotopes), radioactive constituents, and microbial indicators. Naturally occurring isotopes (tritium, carbon-14 isotopes, and stable isotopes of hydrogen, oxygen, nitrogen, boron, and carbon), and dissolved noble gases (noble gases were analyzed in collaboration with Lawrence Livermore National Laboratory) also were measured to help identify the source and age of the sampled ground water. Quality-control samples (blank samples

  13. Phase 1 studies summary of major findings of the South Bay Salt Pond Restoration Project, South San Francisco Bay, California

    Science.gov (United States)

    Valoppi, Laura

    2018-04-02

    Executive SummaryThe South Bay Salt Pond Restoration Project (Project) is one of the largest restoration efforts in the United States. It is located in South San Francisco Bay of California. It is unique not only for its size—more than 15,000 acres—but also for its location adjacent to one of the nation’s largest urban areas, home to more than 4 million people (Alameda, Santa Clara, and San Mateo Counties). The Project is intended to restore and enhance wetlands in South San Francisco Bay while providing for flood management, wildlife-oriented public access, and recreation. Restoration goals of the project are to provide a mosaic of saltmarsh habitat to benefit marsh species and managed ponds to benefit waterbirds, throughout 3 complexes and 54 former salt ponds.Although much is known about the project area, significant uncertainties remain with a project of this geographic and temporal scale of an estimated 50 years to complete the restoration. For example, in order to convert anywhere from 50 to 90 percent of the existing managed ponds to saltmarsh habitat, conservation managers first enhance the habitat of managed ponds in order to increase use by waterbirds, and provide migratory, wintering, and nesting habitat for more than 90 species of waterbirds. Project managers have concluded that the best way to address these uncertainties is to carefully implement the project in phases and learn from the outcome of each phase. The Adaptive Management Plan (AMP) identifies specific restoration targets for multiple aspects of the Project and defines triggers that would necessitate some type of management action if a particular aspect is trending negatively. U.S. Geological Survey (USGS) biologist Laura Valoppi served as the project Lead Scientist and oversaw implementation of the AMP in coordination with other members of the Project Management Team (PMT), comprised of representatives from the California State Coastal Conservancy, California Department of Fish and

  14. Preliminary maps of Quaternary deposits and liquefaction susceptibility, nine-county San Francisco Bay region, California: a digital database

    Science.gov (United States)

    Knudsen, Keith L.; Sowers, Janet M.; Witter, Robert C.; Wentworth, Carl M.; Helley, Edward J.; Nicholson, Robert S.; Wright, Heather M.; Brown, Katherine H.

    2000-01-01

    This report presents a preliminary map and database of Quaternary deposits and liquefaction susceptibility for the nine-county San Francisco Bay region, together with a digital compendium of ground effects associated with past earthquakes in the region. The report consists of (1) a spatial database of fivedata layers (Quaternary deposits, quadrangle index, and three ground effects layers) and two text layers (a labels and leaders layer for Quaternary deposits and for ground effects), (2) two small-scale colored maps (Quaternary deposits and liquefaction susceptibility), (3) a text describing the Quaternary map, liquefaction interpretation, and the ground effects compendium, and (4) the databse description pamphlet. The nine counties surrounding San Francisco Bay straddle the San Andreas fault system, which exposes the region to serious earthquake hazard (Working Group on California Earthquake Probabilities, 1999). Much of the land adjacent to the Bay and the major rivers and streams is underlain by unconsolidated deposits that are particularly vulnerable to earthquake shaking and liquefaction of water-saturated granular sediment. This new map provides a modern and regionally consistent treatment of Quaternary surficial deposits that builds on the pioneering mapping of Helley and Lajoie (Helley and others, 1979) and such intervening work as Atwater (1982), Helley and others (1994), and Helley and Graymer (1997a and b). Like these earlier studies, the current mapping uses geomorphic expression, pedogenic soils, and inferred depositional environments to define and distinguish the map units. In contrast to the twelve map units of Helley and Lajoie, however, this new map uses a complex stratigraphy of some forty units, which permits a more realistic portrayal of the Quaternary depositional system. The two colored maps provide a regional summary of the new mapping at a scale of 1:275,000, a scale that is sufficient to show the general distribution and relationships of

  15. Estimating alcohol-related premature mortality in san francisco: use of population-attributable fractions from the global burden of disease study

    Directory of Open Access Journals (Sweden)

    Reiter Randy B

    2010-11-01

    Full Text Available Abstract Background In recent years, national and global mortality data have been characterized in terms of well-established risk factors. In this regard, alcohol consumption has been called the third leading "actual cause of death" (modifiable behavioral risk factor in the United States, after tobacco use and the combination of poor diet and physical inactivity. Globally and in various regions of the world, alcohol use has been established as a leading contributor to the overall burden of disease and as a major determinant of health disparities, but, to our knowledge, no one has characterized alcohol-related harm in such broad terms at the local level. We asked how alcohol-related premature mortality in San Francisco, measured in years of life lost (YLLs, compares with other well-known causes of premature mortality, such as ischemic heart disease or HIV/AIDS. Methods We applied sex- and cause-specific population-attributable fractions (PAFs of years of life lost (YLLs from the Global Burden of Disease Study to 17 comparable outcomes among San Francisco males and females during 2004-2007. We did this in three ways: Method 1 assumed that all San Franciscans drink like populations in developed economies. These estimates were limited to alcohol-related harm. Method 2 modified these estimates by including several beneficial effects. Method 3 assumed that Latino and Asian San Franciscans drink alcohol like populations in the global regions related to their ethnicity. Results By any of these three methods, alcohol-related premature mortality accounts for roughly a tenth of all YLLs among males. Alcohol-related YLLs among males are comparable to YLLs for leading causes such as ischemic heart disease and HIV/AIDS, in some instances exceeding them. Latino and black males bear a disproportionate burden of harm. Among females, for whom estimates differed more by method and were smaller than those for males, alcohol-related YLLs are comparable to leading

  16. Seismotectonic Implications Of Clustered Regional GPS Velocities In The San Francisco Bay Region, California

    Science.gov (United States)

    Graymer, R. W.; Simpson, R.

    2012-12-01

    We have used a hierarchical agglomerative clustering algorithm with Euclidean distance and centroid linkage, applied to continuous GPS observations for the Bay region available from the U.S. Geological Survey website. This analysis reveals 4 robust, spatially coherent clusters that coincide with 4 first-order structural blocks separated by 3 major fault systems: San Andreas (SA), Southern/Central Calaveras-Hayward-Rodgers Creek-Maacama (HAY), and Northern Calaveras-Concord-Green Valley-Berryessa-Bartlett Springs (NCAL). Because observations seaward of the San Gregorio (SG) fault are few in number, the cluster to the west of SA may actually contain 2 major structural blocks not adequately resolved: the Pacific plate to the west of the northern SA and a Peninsula block between the Peninsula SA and the SG fault. The average inter-block velocities are 11, 10, and 9 mm/yr across SA, HAY, and NCAL respectively. There appears to be a significant component of fault-normal compression across NCAL, whereas SA and HAY faults appear to be, on regional average, purely strike-slip. The velocities for the Sierra Nevada - Great Valley (SNGV) block to the west of NCAL are impressive in their similarity. The cluster of these velocities in a velocity plot forms a tighter grouping compared with the groupings for the other cluster blocks, suggesting a more rigid behavior for this block than the others. We note that for 4 clusters, none of the 3 cluster boundaries illuminate geologic structures other than north-northwest trending dominantly strike-slip faults, so plate motion is not accommodated by large-scale fault-parallel compression or extension in the region or by significant plastic deformation , at least over the time span of the GPS observations. Complexities of interseismic deformation of the upper crust do not allow simple application of inter-block velocities as long-term slip rates on bounding faults. However, 2D dislocation models using inter-block velocities and typical

  17. CONFLICTO, IDENTIDAD Y SENTIDO: EL CASO DEL TAMPIERAZO DE SAN FRANCISCO (CÓRBOBA, 1973

    Directory of Open Access Journals (Sweden)

    Lucas Aimar

    2010-12-01

    Full Text Available Resumen El presente trabajo centra su atención sobre una de las protestas sociales más importantes de la historia de la provincia de Córdoba –ocurrida el 30 de julio de 1973 en la ciudad de San Francisco– conocida indistintamente como Tampierazo, Cordobacito o Sanfranciscazo. El hecho, que paralizó la ciudad y alcanzó momentos de extrema violencia, se inscribe en un amplio contexto de conflictividad social a nivel nacional y provincial; un ciclo de protestas –inaugurado con el Cordobazo– que se extendió hasta por lo menos 1975. Como proponemos, las acciones colectivas deben ser abordadas como un sistema de relaciones internas y externas y no como un simple punto de partida. Por ello, a partir de las redes de conflicto y los marcos de referencia existentes en el momento de la protesta, indagaremos el sentido que la acción tuvo para los actores intervinientes. Como intentaremos demostrar, el Tampierazo fue mucho más que un reclamo por los objetivos particulares de los obreros de la fábrica, convirtiéndose durante la jornada, en una amplia manifestación popular que canalizó el rechazo –compartido intersubjetivamente por varios sectores de la población– a las formas de control y los manejos que se mantenían desde los sectores dominantes del poder local.

  18. Detritus fuels ecosystem metabolism but not metazoan food webs in San Francisco estuary's freshwater delta

    Science.gov (United States)

    Sobczak, W.V.; Cloern, J.E.; Jassby, A.D.; Cole, B.E.; Schraga, T.S.; Arnsberg, A.

    2005-01-01

    Detritus from terrestrial ecosystems is the major source of organic matter in many streams, rivers, and estuaries, yet the role of detritus in supporting pelagic food webs is debated. We examined the importance of detritus to secondary productivity in the Sacramento and San Joaquin River Delta (California, United States), a large complex of tidal freshwater habitats. The Delta ecosystem has low primary productivity but large detrital inputs, so we hypothesized that detritus is the primary energy source fueling production in pelagic food webs. We assessed the sources, quantity, composition, and bioavailability of organic matter among a diversity of habitats (e.g., marsh sloughs, floodplains, tidal lakes, and deep river channels) over two years to test this hypothesis. Our results support the emerging principle that detritus dominates riverine and estuarine organic matter supply and supports the majority of ecosystem metabolism. Yet in contrast to prevailing ideas, we found that detritus was weakly coupled to the Delta's pelagic food web. Results from independent approaches showed that phytoplankton production was the dominant source of organic matter for the Delta's pelagic food web, even though primary production accounts for a small fraction of the Delta's organic matter supply. If these results are general, they suggest that the value of organic matter to higher trophic levels, including species targeted by programs of ecosystem restoration, is a function of phytoplankton production. ?? 2005 Estuarine Research Federation.

  19. Iglesia y participación comunitaria en salud: el caso del Municipio San Francisco del estado Zulia, Venezuela

    Directory of Open Access Journals (Sweden)

    José Guillermo García

    2002-01-01

    Full Text Available Este trabajo tiene por objeto identificar en forma comparada los factores que condicionan la participación de las comunidades Betulio González y 24 de Julio del municipio San Francisco del estado Zulia en el subprograma de Medicina Natural que promociona la Iglesia Católica. Bajo un esquema conceptual que combina principios de las teorías: Elección Racional, Movilización de Recursos, Privación Relativa, Identidades Colectivas y Capital Social, se plantea la hipótesis que la participación de dichas comunidades en el subprograma está determinada por una serie de factores internos y externos en donde resaltan la representación social que tienen del subprograma, el cálculo racional de la acción, la tradición participativa y el apoyo organizativo de grupos voluntarios. Se empleó la perspectiva etnomedotológica en la realización de entrevistas en profundidad, de donde se extrajo como conclusión que existen factores comunes que condicionan la participación en ambas comunidades, tales como la reafirmación de una identidad femenina entendida como un incentivo para la acción, una representación colectiva positiva sobre la medicina natural y la presencia de recursos organizativos externos proporcionados por las escuelas ubicadas en cada comunidad, por grupos eclesiales de base y por la misma Iglesia Católica como agente promotor del subprograma.

  20. Early exclusive breastfeeding and maternal attitudes towards infant feeding in a population of new mothers in San Francisco, California.

    Science.gov (United States)

    Wojcicki, Janet M; Gugig, Roberto; Tran, Cam; Kathiravan, Suganya; Holbrook, Katherine; Heyman, Melvin B

    2010-02-01

    Positive parental attitudes towards infant feeding are an important component in child nutritional health. Previous studies have found that participants in the Special Supplemental Women, Infants, and Children (WIC) Program have lower breastfeeding rates and attitudes that do not contribute towards healthy infant feeding in spite of breastfeeding and nutrition education programs targeting WIC participants. The objective of this study was to assess the frequency of exclusive breastfeeding in the early postpartum period and maternal attitudes towards breastfeeding in a population of mothers at two San Francisco hospitals and in relation to WIC participation status. We interviewed women who had recently delivered a healthy newborn using a structured interview. A high percentage (79.8%) of our sample was exclusively breastfeeding at 1-4 days postpartum. We did not find any significant differences in rates of formula or mixed feeding by WIC participant status. Independent risk factors for mixed or formula feeding at 1-3 days postpartum included Asian/Pacific Islander ethnicity (odds ratio [OR] 2.90, 95% confidence interval [CI] 1.17-7.19). Being a college graduate was associated with a decreased risk of formula/mixed feeding (OR 0.28, 95% CI 0.10-0.79). We also found that thinking breastfeeding was physically painful and uncomfortable was independently associated with not breastfeeding (OR 1.41, 95% CI 1.06-1.89). Future studies should be conducted with Asian-Americans and Pacific Islanders to better understand the lower rates of exclusive breastfeeding in this population and should address negative attitudes towards breastfeeding such as the idea that breastfeeding is painful or uncomfortable.

  1. Per- and polyfluoroalkyl substances (PFASs) in San Francisco Bay wildlife: Temporal trends, exposure pathways, and notable presence of precursor compounds.

    Science.gov (United States)

    Sedlak, Margaret D; Benskin, Jonathan P; Wong, Adam; Grace, Richard; Greig, Denise J

    2017-10-01

    Concentrations of perfluorooctane sulfonate (PFOS) in San Francisco Bay (SF Bay) wildlife have historically been among the highest reported globally. To track continuing exposures to PFASs and assess the impact of the 2002 phase-out of production of PFOS and related chemicals in the US, nine perfluoroalkyl carboxylic acids (PFCAs; C4-C12), three perfluoroalkyl sulfonic acids (PFSAs; C4, C6, C8) and perfluorooctane sulfonamide (PFOSA, a PFOS precursor) were measured in SF Bay cormorant eggs in 2012 and harbor seal serum sampled between 2009 and 2014. PFOS remained the dominant perfluoroalkyl acid (PFAA) in both cormorant eggs (36.1-466 ng/g) and seals (12.6-796 ng/g) from 2012 and 2014, respectively. Concentrations in seal and bird eggs from the South Bay have declined approximately 70% in both matrices. To elucidate potential pathways of exposure, prey fish, sediments and wastewater effluent were analyzed for PFASs, and in the case of sediment and effluent, a suite of PFAA precursors. PFOS was the dominant PFAA in prey fish and sediment. In effluent, different mixtures of PFAAs were measured, with PFOS, PFHxA, and PFOA detected in the highest concentrations. Polyfluoroalkyl phosphate diesters (PFCA-precursors) were observed at concentrations over an order of magnitude higher than PFCAs in sediment, highlighting their importance as a potential, on-going source of PFCAs to SF Bay wildlife. These findings suggest that the PFOS phase-out has resulted in reduced burdens to wildlife in SF Bay, but that exposure to diverse and incompletely characterized PFASs continues. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Self-Perceived Viral Load and Sexual Risk Behavior Among Known HIV-Positive MSM in San Francisco, 2014.

    Science.gov (United States)

    Guigayoma, John; Chen, Yea-Hung; Snowden, Jonathan M; Santos, Glenn-Milo; Hecht, Jennifer; Raymond, H Fisher

    2017-07-01

    Self-perceived viral suppression status among men who have sex with men (MSM) may impact HIV risk transmission behaviors. We conducted a 2014 cross-sectional survey of MSM in San Francisco and assessed differences in sexual risk behavior among known HIV-positive MSM based on viral suppression of HIV. We collected demographics, self-perceived viral load status, and sexual risk behavior and tested for viral load levels through laboratory assays. Men were categorized in a hierarchical schema of sexual risk behavior categories based on responses to questions regarding recent partners' HIV status, condom use, and sexual positioning. We used Fisher exact tests to assess for differences based on self-perceived viral load status. Out of a sample of 96 known HIV-positive men, 59 men self-reported an undetectable HIV viral load and 9 men self-reported a detectable viral load consented to confirmatory laboratory testing. The sample of self-reported undetectable men had gradually larger proportions of higher-risk sexual practices, whereas the sample of detectable men was evenly distributed across sexual practices. This association was not statistically significant (P = 0.91). Self-perceived viral suppression may influence sexual practices of known HIV-positive MSM, but small sample size, especially within the detectable category, hinders our ability to determine statistical significance. More research is necessary to assess how HIV-positive men account for viral load in sexual decision-making practices, and this research may inform resource allocation and clinical recommendations to maintain the health of MSM populations.

  3. Predictors of incident herpes simplex virus type 2 infections in young women at risk for unintended pregnancy in San Francisco

    Directory of Open Access Journals (Sweden)

    Padian Nancy

    2007-09-01

    Full Text Available Abstract Background Young women receiving family planning services are at risk for both unintended pregnancy and herpes simplex virus type 2 (HSV-2 infection. Methods We performed a secondary analysis using data from a previously published randomized controlled trial evaluating access to emergency contraception on reproductive health outcomes. Women aged 15 to 24 years were recruited from two Planned Parenthood clinics and two community health clinics in San Francisco. Demographic information and sexual history were obtained by interview. HSV-2 seropositivity was determined by fingerstick blood test. New pregnancies were measured by self-report, urine testing and medical chart review. Subjects were evaluated for incident HSV-2 infection and pregnancy at a 6-month follow-up appointment. Women who were pregnant or intending to become pregnant at enrolment were excluded. Results At enrolment 2,104 women were screened for HSV-2 and 170 (8.1% were seropositive. Eighty-seven percent of initially seronegative women completed the study (n = 1,672 and 73 (4.4% became HSV-2 seropositive. HSV-2 seroincidence was 7.8 cases per 100 person-years. One hundred and seventeen women (7% became pregnant and 7 (6% of these had a seroincident HSV-2 infection during the study. After adjustment for confounders, predictors of incident HSV-2 infection were African American race and having multiple partners in the last six months. Condom use at last sexual encounter was protective. Conclusion HSV-2 seroincidence and the unintended pregnancy rate in young women were high. Providers who counsel women on contraceptive services and sexually transmitted infection prevention could play an expanded role in counselling women about HSV-2 prevention given the potential sequelae in pregnancy. The potential benefit of targeted screening and future vaccination against HSV-2 needs to be assessed in this population.

  4. The Incidence and Prevalence of Systemic Lupus Erythematosus in San Francisco County, California: The California Lupus Surveillance Project.

    Science.gov (United States)

    Dall'Era, Maria; Cisternas, Miriam G; Snipes, Kurt; Herrinton, Lisa J; Gordon, Caroline; Helmick, Charles G

    2017-10-01

    Estimates of the incidence and prevalence of systemic lupus erythematosus (SLE) in the US have varied widely. The purpose of this study was to conduct the California Lupus Surveillance Project (CLSP) to determine credible estimates of SLE incidence and prevalence, with a special focus on Hispanics and Asians. The CLSP, which is funded by the Centers for Disease Control and Prevention, is a population-based registry of individuals with SLE residing in San Francisco County, CA, from January 1, 2007 through December 31, 2009. Data sources included hospitals, rheumatologists, nephrologists, commercial laboratories, and a state hospital discharge database. We abstracted medical records to ascertain SLE cases, which we defined as patients who met ≥4 of the 11 American College of Rheumatology classification criteria for SLE. We estimated crude and age-standardized incidence and prevalence, which were stratified by sex and race/ethnicity. The overall age-standardized annual incidence rate was 4.6 per 100,000 person-years. The average annual period prevalence was 84.8 per 100,000 persons. The age-standardized incidence rate in women and men was 8.6 and 0.7 per 100,000 person-years, respectively. This rate was highest among black women (30.5), followed by Hispanic women (8.9), Asian women (7.2), and white women (5.3). The age-standardized prevalence in women per 100,000 persons was 458.1 in blacks, 177.9 in Hispanics, 149.7 in Asians, and 109.8 in whites. Capture-recapture modeling estimated 33 additional incident cases and 147 additional prevalent cases. Comprehensive methods that include intensive case-finding provide more credible estimates of SLE in Hispanics and Asians, and confirm racial and ethnic disparities in SLE. The disease burden of SLE is highest in black women, followed by Hispanic women, Asian women, and white women. © 2017, American College of Rheumatology.

  5. Gas exchange rates across the sediment-water andd air-water interfaces in south San Francisco Bay

    International Nuclear Information System (INIS)

    Hartman, B.; Hammond, D.E.

    1984-01-01

    Radon 222 concentrations in the water and sedimentary columns and radon exchange rates across the sediment-water and air-water interfaces have been measured in a section of south San Francisco Bay. Two independent methods have been used to determine sediment-water exchange rates, and the annual averages of these methods agree within the uncertainity of the determinations, about 20%. The annual average of bethic fluxes from shoal areas is nearly a factor of 2 greater than fluxes from the channel areas. Fluxes from the shoal and channel areas exceed those expected from simple molecular diffusion by factors of 4 and 2, respectively, apparently due to macrofaunal irrigation. Values of the gas transfer coefficient for radon exchange across the air-water inteface were determined by constructing a radon mass balance for the water column and by direct measurement using floating chambers. The chamber method appears to yield results which are too high. Transfer coefficients computed using the mass balance method range from 0.4 m/day to 1.8 m/day, with a 6-year average of 1.0 m/day. Gas exchange is linearly dependent upon wind speed over a wind speed range of 3.2--6.4 m/s, but shows no dependence upon current velocity. Gas transfer coefficients predicted from an empirical relationship between gas exchange rates and wind speed observed in lakes and the oceans are within 30% of the coefficients determined from the radon mass balance and are considerably more accurate than coefficients predicted from theoretical gas exchange models

  6. Modeling of response, socioeconomic, and natural resource damage costs for hypothetical oil spill scenarios in San Francisco Bay

    International Nuclear Information System (INIS)

    Etkin, D.S.; French McCay, D.; Whittier, N.; Sankaranarayanan, S.; Jennings, J.

    2002-01-01

    A study was conducted to determine the influence of oil type, spill size, response strategy and location factors on oil spill response costs, with particular reference to the cost benefits of the use of dispersants. Modeling has been conducted for a hypothetical oil spill in San Francisco Bay to determine biological impacts, damages to natural resources and response costs. The SIMAP modeling software by the Applied Science Associates was used to model 3 spill sizes (20, 50 and 95 percentile by volume) and 4 types of oil (gasoline, diesel, heavy fuel oil, and crude oil). Response costs, natural resource damages and socioeconomic impact were determined based on spill trajectory and fate. Mechanical recovery-based operations carry higher response costs than dispersant-based operations. Response costs for diesel and gasoline spills make up 20 per cent of the total costs, compared to 43 per cent for crude and heavy fuel oil spills. Damages to natural resources are higher for spills of toxic lighter fuels such as gasoline and diesel because gasoline has a greater impact on the water column with less shoreline oiling, resulting in more damages to natural resources. Heavier oils have a greater impact on shorelines and higher response and socioeconomic costs. Although socioeconomic costs varied by location, they tend to be greater than response costs and natural resource damage costs. Proportions of the different costs were described with reference to various spill factors. Socioeconomic costs are 61, 76, 45 and 53 per cent respectively for gasoline, diesel, crude oil, and heavy fuel oil spills. 27 refs., 23 tabs., 5 figs

  7. Projected evolution of California's San Francisco Bay-Delta-River System in a century of continuing climate change

    Science.gov (United States)

    Cloern, James E.; Knowles, Noah; Brown, Larry R.; Cayan, Daniel; Dettinger, Michael D.; Morgan, Tara L.; Schoellhamer, David H.; Stacey, Mark T.; van der Wegen, Mick; Wagner, R. Wayne; Jassby, Alan D.

    2011-01-01

    Background Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing challenges to sustainability of native species. Methodology/Principal Findings We linked a series of models to investigate responses of California's San Francisco Estuary-Watershed (SFEW) system to two contrasting scenarios of climate change. Model outputs for scenarios of fast and moderate warming are presented as 2010–2099 projections of nine indicators of changing climate, hydrology and habitat quality. Trends of these indicators measure rates of: increasing air and water temperatures, salinity and sea level; decreasing precipitation, runoff, snowmelt contribution to runoff, and suspended sediment concentrations; and increasing frequency of extreme environmental conditions such as water temperatures and sea level beyond the ranges of historical observations. Conclusions/Significance Most of these environmental indicators change substantially over the 21st century, and many would present challenges to natural and managed systems. Adaptations to these changes will require flexible planning to cope with growing risks to humans and the challenges of meeting demands for fresh water and sustaining native biota. Programs of ecosystem rehabilitation and biodiversity conservation in coastal landscapes will be most likely to meet their objectives if they are designed from considerations that include: (1) an integrated perspective that river-estuary systems are influenced by effects of climate change operating on both watersheds and oceans; (2) varying sensitivity among environmental indicators to the uncertainty of future climates; (3) inevitability of biological community

  8. Projected evolution of California's San Francisco bay-delta-river system in a century of climate change

    Science.gov (United States)

    Cloern, James E.; Knowles, Noah; Brown, Larry R.; Cayan, Daniel R.; Dettinger, Michael D.; Morgan, Tara L.; Schoellhamer, David H.; Stacey, Mark T.; Van der Wegen, Mick; Wagner, R.W.; Jassby, Alan D.

    2011-01-01

    Background: Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing challenges to sustainability of native species. Methodology/Principal Findings: We linked a series of models to investigate responses of California's San Francisco Estuary-Watershed (SFEW) system to two contrasting scenarios of climate change. Model outputs for scenarios of fast and moderate warming are presented as 2010-2099 projections of nine indicators of changing climate, hydrology and habitat quality. Trends of these indicators measure rates of: increasing air and water temperatures, salinity and sea level; decreasing precipitation, runoff, snowmelt contribution to runoff, and suspended sediment concentrations; and increasing frequency of extreme environmental conditions such as water temperatures and sea level beyond the ranges of historical observations. Conclusions/Significance: Most of these environmental indicators change substantially over the 21st century, and many would present challenges to natural and managed systems. Adaptations to these changes will require flexible planning to cope with growing risks to humans and the challenges of meeting demands for fresh water and sustaining native biota. Programs of ecosystem rehabilitation and biodiversity conservation in coastal landscapes will be most likely to meet their objectives if they are designed from considerations that include: (1) an integrated perspective that river-estuary systems are influenced by effects of climate change operating on both watersheds and oceans; (2) varying sensitivity among environmental indicators to the uncertainty of future climates; (3) inevitability of biological community

  9. Temporal fluctuations in grain size, organic materials and iron concentrations in intertidal surface sediment of San Francisco Bay

    Science.gov (United States)

    Thomson-Becker, E. A.; Luoma, S.N.

    1985-01-01

    The physical and chemical characteristics of the oxidized surface sediment in an estuary fluctuate temporally in response to physical forces and apparently-fluctuating inputs. These characteristics, which include grain size and concentrations of organic materials and iron, will influence both trace-metal geochemistry and bioavailability. Temporal trends in the abundance of fine particles, total organic carbon content (TOC), absorbance of extractable organic material (EOM), and concentration of extractable iron in the sediment of San Francisco Bay were assessed using data sets containing approximately monthly samples for periods of two to seven years. Changes in wind velocity and runoff result in monthly changes in the abundance of fine particles in the intertidal zone. Fine-grained particles are most abundant in the late fall/early winter when runoff is elevated and wind velocities are low; particles are coarser in the summer when runoff is low and wind velocities are consistently high. Throughout the bay, TOC is linearly related to fine particle abundance (r = 0.61). Temporal variability occurs in this relationship, as particles are poor in TOC relative to percent of fine particles in the early rainy season. Iron-poor particles also appear to enter the estuary during high runoff periods; while iron is enriched on particle surfaces in the summer. Concentrations of extractable iron and absorbance of EOM vary strongly from year to year. Highest absorbances of EOM occurred in the first year following the drought in 1976-77, and in 1982 and 1983 when river discharge was unusually high. Extractable-iron concentrations were also highest in 1976-77, but were very low in 1982 and 1983. ?? 1985 Dr W. Junk Publishers.

  10. Mapping elevations of tidal wetland restoration sites in San Francisco Bay: Comparing accuracy of aerial lidar with a singlebeam echosounder

    Science.gov (United States)

    Athearn, N.D.; Takekawa, John Y.; Jaffe, B.; Hattenbach, B.J.; Foxgrover, A.C.

    2010-01-01

    The southern edge of San Francisco Bay is surrounded by former salt evaporation ponds, where tidal flow has been restricted since the mid to late 1890s. These ponds are now the focus of a large wetland restoration project, and accurate measurement of current pond bathymetry and adjacent mud flats has been critical to restoration planning. Aerial light detection and ranging (lidar) has become a tool for mapping surface elevations, but its accuracy had rarely been assessed for wetland habitats. We used a singlebeam echosounder system we developed for surveying shallow wetlands to map submerged pond bathymetry in January of 2004 and compared those results with aerial lidar surveys in two ponds that were dry in May of 2004. From those data sets, we compared elevations for 5164 (Pond E9, 154 ha) and 2628 (Pond E14, 69 ha) echosounder and lidar points within a 0.375-m radius of each other (0.750-m diameter lidar spot size). We found that mean elevations of the lidar points were lower than the echosounder results by 5 ?? 0.1 cm in Pond E9 and 2 ?? 0.2 cm in Pond E14. Only a few points (5% in Pond E9, 2% in Pond E14) differed by more than 20 cm, and some of these values may be explained by residual water in the ponds during the lidar survey or elevation changes that occurred between surveys. Our results suggest that aerial lidar may be a very accurate and rapid way to assess terrain elevations for wetland restoration projects. ?? 2010 Coastal Education and Research Foundation.

  11. Dietary flexibility in three representative waterbirds across salinity and depth gradients in salt ponds of San Francisco Bay

    Science.gov (United States)

    Takekawa, John Y.; Miles, A.K.; Tsao-Melcer, D. C.; Schoellhamer, D.H.; Fregien, S.; Athearn, N.D.

    2009-01-01

    Salt evaporation ponds have existed in San Francisco Bay, California, for more than a century. In the past decade, most of the salt ponds have been retired from production and purchased for resource conservation with a focus on tidal marsh restoration. However, large numbers of waterbirds are found in salt ponds, especially during migration and wintering periods. The value of these hypersaline wetlands for waterbirds is not well understood, including how different avian foraging guilds use invertebrate prey resources at different salinities and depths. The aim of this study was to investigate the dietary flexibility of waterbirds by examining the population number and diet of three feeding guilds across a salinity and depth gradient in former salt ponds of the Napa-Sonoma Marshes. Although total invertebrate biomass and species richness were greater in low than high salinity salt ponds, waterbirds fed in ponds that ranged from low (20 g l-1) to very high salinities (250 g l -1). American avocets (surface sweeper) foraged in shallow areas at pond edges and consumed a wide range of prey types (8) including seeds at low salinity, but preferred brine flies at mid salinity (40-80 g l-1). Western sandpipers (prober) focused on exposed edges and shoal habitats and consumed only a few prey types (2-4) at both low and mid salinities. Suitable depths for foraging were greatest for ruddy ducks (diving benthivore) that consumed a wide variety of invertebrate taxa (5) at low salinity, but focused on fewer prey (3) at mid salinity. We found few brine shrimp, common in higher salinity waters, in the digestive tracts of any of these species. Dietary flexibility allows different guilds to use ponds across a range of salinities, but their foraging extent is limited by available water depths. ?? 2009 USGS, US Government.

  12. Gender differences in sexual and injection risk behavior among active young injection drug users in San Francisco (the UFO Study).

    Science.gov (United States)

    Evans, Jennifer L; Hahn, Judith A; Page-Shafer, Kimberly; Lum, Paula J; Stein, Ellen S; Davidson, Peter J; Moss, Andrew R

    2003-03-01

    Female injection drug users (IDUs) represent a large proportion of persons infected with HIV in the United States, and women who inject drugs have a high incidence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. Therefore, it is important to understand the role of gender in injection risk behavior and the transmission of blood-borne virus. In 2000-2002, 844 young (<30 years old) IDUs were surveyed in San Francisco. We compared self-reported risk behavior between 584 males and 260 female participants from cross-sectional baseline data. We used logistic regression to determine whether demographic, structural, and relationship variables explained increased needle borrowing, drug preparation equipment sharing, and being injected by another IDU among females compared to males. Females were significantly younger than males and were more likely to engage in needle borrowing, ancillary equipment sharing, and being injected by someone else. Females were more likely than males to report recent sexual intercourse and to have IDU sex partners. Females and males were not different with respect to education, race/ethnicity, or housing status. In logistic regression models for borrowing a used needle and sharing drug preparation equipment, increased risk in females was explained by having an injection partner who was also a sexual partner. Injecting risk was greater in the young female compared to male IDUs despite equivalent frequency of injecting. Overlapping sexual and injection partnerships were a key factor in explaining increased injection risk in females. Females were more likely to be injected by another IDU even after adjusting for years injecting, being in a relationship with another IDU, and other potential confounders. Interventions to reduce sexual and injection practices that put women at risk of contracting hepatitis and HIV are needed.

  13. Trends in methamphetamine use in young injection drug users in San Francisco from 1998 to 2004: the UFO Study.

    Science.gov (United States)

    Inglez-Dias, Aline; Hahn, Judith A; Lum, Paula J; Evans, Jennifer; Davidson, Peter; Page-Shafer, Kimberly

    2008-05-01

    To describe temporal trends in methamphetamine use among young injection drug users (IDU) in San Francisco. Secondary analysis of cross-sectional baseline data collected for a longitudinal study of young IDU from 1998 to 2004. Participants were 1445 young IDU (<30 years old) who reported injection in the previous month, English-speaking, and recruited by street outreach methods. We examined trends for: lifetime (ever) and recent (30-day) methamphetamine use, including injected and non-injected, and by age group and sexual risk behaviour [men who have sex with men injecting drug users (MSM-IDU), male IDU (non-MSM) and female IDU]. In 1998, 1999, 2000, 2001, 2003 and 2004 we interviewed 237, 276, 431, 310, 147 and 44 participants, respectively. Overall, median age was 22 years [interquartile range (IQR) 20-25], 30.3% were women and median duration of injecting was 4.4 years (IQR 2-7). Prevalence of methamphetamine use was high, with 50.1% reporting recent injection, but overall there were no temporal increases in reported 'ever' injected use. Recent methamphetamine injection (past 30 days) increased significantly, and peaked at 60% in 2003. MSM-IDU had higher methamphetamine injection ever (92.3%) and recently (59.5%) compared to heterosexual male (non-MSM) IDU (81.6% and 47.3%, respectively) and to female IDU (78.4% and 46.1%, respectively). Despite reports of ubiquitous increases in methamphetamine use, there were no significant increases in 6 years in ever injecting methamphetamine overall among young IDU. MSM-IDU who reported the highest methamphetamine use overall reported some increases in recent injected use. The methamphetamine 'epidemic' was probably under way among young IDU earlier than other populations.

  14. Gas exchange rates across the sediment-water and air-water interfaces in south San Francisco Bay

    Science.gov (United States)

    Hartman, Blayne; Hammond, Douglas E.

    1984-01-01

    Radon 222 concentrations in the water and sedimentary columns and radon exchange rates across the sediment-water and air-water interfaces have been measured in a section of south San Francisco Bay. Two independent methods have been used to determine sediment-water exchange rates, and the annual averages of these methods agree within the uncertainty of the determinations, about 20%. The annual average of benthic fluxes from shoal areas is nearly a factor of 2 greater than fluxes from the channel areas. Fluxes from the shoal and channel areas exceed those expected from simple molecular diffusion by factors of 4 and 2, respectively, apparently due to macrofaunal irrigation. Values of the gas transfer coefficient for radon exchange across the air-water interface were determined by constructing a radon mass balance for the water column and by direct measurement using floating chambers. The chamber method appears to yield results which are too high. Transfer coefficients computed using the mass balance method range from 0.4 m/day to 1.8 m/day, with a 6-year average of 1.0 m/day. Gas exchange is linearly dependent upon wind speed over a wind speed range of 3.2–6.4 m/s, but shows no dependence upon current velocity. Gas transfer coefficients predicted from an empirical relationship between gas exchange rates and wind speed observed in lakes and the oceans are within 30% of the coefficients determined from the radon mass balance and are considerably more accurate than coefficients predicted from theoretical gas exchange models.

  15. Modeling fates and impacts for bio-economic analysis of hypothetical oil spill scenarios in San Francisco Bay

    International Nuclear Information System (INIS)

    French McCay, D.; Whittier, N.; Sankaranarayanan, S.; Jennings, J.; Etkin, D.S.

    2002-01-01

    The oil spill risks associated with four submerged rock pinnacles near Alcatraz Island in San Francisco Bay are being evaluated by the United States Army Corps of Engineers. Oil spill modeling has been conducted for a hypothetical oil spill to determine biological impacts, damages to natural resources and response costs. The scenarios are hypothetical vessel grounding on the pinnacles. The SIMAP modeling software by the Applied Science Associates was used to model 3 spill sizes (20, 50 and 95 percentile by volume) and 4 types of oil (gasoline, diesel, heavy fuel oil, and crude oil). The frequency distribution of oil fates and impacts was determined by first running each scenario in stochastic mode. The oil fates and biological effects of the spills were the focus of this paper. It was shown that diesel and crude oil spills would have greater impacts in the water column than heavy fuel or gasoline because gasoline is more volatile and less toxic and because heavy oil spills would be small in volume. It was determined that the major impacts and damage to birds would be low due to the high dilution potential of the bay. It was also noted that dispersants would be very effective in reducing impacts on wildlife and the shoreline. These results are being used to evaluate the cost-benefit analysis of removing the rocks versus the risk of an oil spill. The work demonstrates a statistically quantifiable method to estimate potential impacts that could be used in ecological risk assessment and cost-benefit analysis. 15 refs., 13 tabs., 11 figs

  16. Projected evolution of California's San Francisco Bay-Delta-river system in a century of climate change.

    Directory of Open Access Journals (Sweden)

    James E Cloern

    Full Text Available Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing challenges to sustainability of native species.We linked a series of models to investigate responses of California's San Francisco Estuary-Watershed (SFEW system to two contrasting scenarios of climate change. Model outputs for scenarios of fast and moderate warming are presented as 2010-2099 projections of nine indicators of changing climate, hydrology and habitat quality. Trends of these indicators measure rates of: increasing air and water temperatures, salinity and sea level; decreasing precipitation, runoff, snowmelt contribution to runoff, and suspended sediment concentrations; and increasing frequency of extreme environmental conditions such as water temperatures and sea level beyond the ranges of historical observations.Most of these environmental indicators change substantially over the 21(st century, and many would present challenges to natural and managed systems. Adaptations to these changes will require flexible planning to cope with growing risks to humans and the challenges of meeting demands for fresh water and sustaining native biota. Programs of ecosystem rehabilitation and biodiversity conservation in coastal landscapes will be most likely to meet their objectives if they are designed from considerations that include: (1 an integrated perspective that river-estuary systems are influenced by effects of climate change operating on both watersheds and oceans; (2 varying sensitivity among environmental indicators to the uncertainty of future climates; (3 inevitability of biological community changes as responses to cumulative effects of climate

  17. How can climate change and engineered water conveyance affect sediment dynamics in the San Francisco Bay-Delta system?

    Science.gov (United States)

    Achete, Fernanda; Van der Wegen, Mick; Roelvink, Jan Adriaan; Jaffe, Bruce E.

    2017-01-01

    Suspended sediment concentration is an important estuarine health indicator. Estuarine ecosystems rely on the maintenance of habitat conditions, which are changing due to direct human impact and climate change. This study aims to evaluate the impact of climate change relative to engineering measures on estuarine fine sediment dynamics and sediment budgets. We use the highly engineered San Francisco Bay-Delta system as a case study. We apply a process-based modeling approach (Delft3D-FM) to assess the changes in hydrodynamics and sediment dynamics resulting from climate change and engineering scenarios. The scenarios consider a direct human impact (shift in water pumping location), climate change (sea level rise and suspended sediment concentration decrease), and abrupt disasters (island flooding, possibly as the results of an earthquake). Levee failure has the largest impact on the hydrodynamics of the system. Reduction in sediment input from the watershed has the greatest impact on turbidity levels, which are key to primary production and define habitat conditions for endemic species. Sea level rise leads to more sediment suspension and a net sediment export if little room for accommodation is left in the system due to continuous engineering works. Mitigation measures like levee reinforcement are effective for addressing direct human impacts, but less effective for a persistent, widespread, and increasing threat like sea level rise. Progressive adaptive mitigation measures to the changes in sediment and flow dynamics resulting from sea level rise may be a more effective strategy. Our approach shows that a validated process-based model is a useful tool to address long-term (decades to centuries) changes in sediment dynamics in highly engineered estuarine systems. In addition, our modeling approach provides a useful basis for long-term, process-based studies addressing ecosystem dynamics and health.

  18. How food insecurity contributes to poor HIV health outcomes: Qualitative evidence from the San Francisco Bay Area.

    Science.gov (United States)

    Whittle, Henry J; Palar, Kartika; Seligman, Hilary K; Napoles, Tessa; Frongillo, Edward A; Weiser, Sheri D

    2016-12-01

    Food-insecure people living with HIV/AIDS (PLHIV) consistently exhibit worse clinical outcomes than their food-secure counterparts. This relationship is mediated in part through non-adherence to antiretroviral therapy (ART), sub-optimal engagement in HIV care, and poor mental health. An in-depth understanding of how these pathways operate in resource-rich settings, however, remains elusive. We aimed to understand the relationship between food insecurity and HIV health among low-income individuals in the San Francisco Bay Area using qualitative methods. Semi-structured in-depth interviews were conducted with 34 low-income PLHIV receiving food assistance from a non-profit organization. Interviews explored experiences with food insecurity and its perceived effects on HIV-related health, mental health, and health behaviors including taking ART and attending clinics. Thematic content analysis of transcripts followed an integrative inductive-deductive approach. Food insecurity was reported to contribute to poor ART adherence and missing scheduled clinic visits through various mechanisms, including exacerbated ART side effects in the absence of food, physical feelings of hunger and fatigue, and HIV stigma at public free-meal sites. Food insecurity led to depressive symptoms among participants by producing physical feelings of hunger, aggravating pre-existing struggles with depression, and nurturing a chronic self-perception of social failure. Participants further explained how food insecurity, depression, and ART non-adherence could reinforce each other in complex interactions. Our study demonstrates how food insecurity detrimentally shapes HIV health behavior and outcomes through complex and interacting mechanisms, acting via multiple socio-ecological levels of influence in this setting. The findings emphasize the need for broad, multisectoral approaches to tackling food insecurity among urban poor PLHIV in the United States. Copyright © 2016 Elsevier Ltd. All rights

  19. Projected Evolution of California's San Francisco Bay-Delta-River System in a Century of Climate Change

    Science.gov (United States)

    Cloern, James E.; Knowles, Noah; Brown, Larry R.; Cayan, Daniel; Dettinger, Michael D.; Morgan, Tara L.; Schoellhamer, David H.; Stacey, Mark T.; van der Wegen, Mick; Wagner, R. Wayne; Jassby, Alan D.

    2011-01-01

    Background Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing challenges to sustainability of native species. Methodology/Principal Findings We linked a series of models to investigate responses of California's San Francisco Estuary-Watershed (SFEW) system to two contrasting scenarios of climate change. Model outputs for scenarios of fast and moderate warming are presented as 2010–2099 projections of nine indicators of changing climate, hydrology and habitat quality. Trends of these indicators measure rates of: increasing air and water temperatures, salinity and sea level; decreasing precipitation, runoff, snowmelt contribution to runoff, and suspended sediment concentrations; and increasing frequency of extreme environmental conditions such as water temperatures and sea level beyond the ranges of historical observations. Conclusions/Significance Most of these environmental indicators change substantially over the 21st century, and many would present challenges to natural and managed systems. Adaptations to these changes will require flexible planning to cope with growing risks to humans and the challenges of meeting demands for fresh water and sustaining native biota. Programs of ecosystem rehabilitation and biodiversity conservation in coastal landscapes will be most likely to meet their objectives if they are designed from considerations that include: (1) an integrated perspective that river-estuary systems are influenced by effects of climate change operating on both watersheds and oceans; (2) varying sensitivity among environmental indicators to the uncertainty of future climates; (3) inevitability of biological community

  20. Novel analyses of long-term data provide a scientific basis for chlorophyll-a thresholds in San Francisco Bay

    Science.gov (United States)

    Sutula, Martha; Kudela, Raphael; Hagy, James D.; Harding, Lawrence W.; Senn, David; Cloern, James E.; Bricker, Suzanne; Berg, Gry Mine; Beck, Marcus

    2017-10-01

    San Francisco Bay (SFB), USA, is highly enriched in nitrogen and phosphorus, but has been resistant to the classic symptoms of eutrophication associated with over-production of phytoplankton. Observations in recent years suggest that this resistance may be weakening, shown by: significant increases of chlorophyll-a (chl-a) and decreases of dissolved oxygen (DO), common occurrences of phytoplankton taxa that can form Harmful Algal Blooms (HAB), and algal toxins in water and mussels reaching levels of concern. As a result, managers now ask: what levels of chl-a in SFB constitute tipping points of phytoplankton biomass beyond which water quality will become degraded, requiring significant nutrient reductions to avoid impairments? We analyzed data for DO, phytoplankton species composition, chl-a, and algal toxins to derive quantitative relationships between three indicators (HAB abundance, toxin concentrations, DO) and chl-a. Quantile regressions relating HAB abundance and DO to chl-a were significant, indicating SFB is at increased risk of adverse HAB and low DO levels if chl-a continues to increase. Conditional probability analysis (CPA) showed chl-a of 13 mg m-3 as a "protective" threshold below which probabilities for exceeding alert levels for HAB abundance and toxins were reduced. This threshold was similar to chl-a of 13-16 mg m-3 that would meet a SFB-wide 80% saturation Water Quality Criterion (WQC) for DO. Higher "at risk" chl-a thresholds from 25 to 40 mg m-3 corresponded to 0.5 probability of exceeding alert levels for HAB abundance, and for DO below a WQC of 5.0 mg L-1 designated for lower South Bay (LSB) and South Bay (SB). We submit these thresholds as a basis to assess eutrophication status of SFB and to inform nutrient management actions. This approach is transferrable to other estuaries to derive chl-a thresholds protective against eutrophication.

  1. Connecting Past to Present and Watersheds to Ocean: Modeling 165 Years of Incremental Changes to Flows into the San Francisco Bay Delta System

    Science.gov (United States)

    MacVean, L. J.; Thompson, S. E.; Huttom, P. H.; Sivapalan, M.

    2016-02-01

    California's Sacramento-San Joaquin Delta sits at the intersection of vast agricultural and population centers, and supplies fresh water for the diverse and often competing needs of ecosystems, farmers, and millions of Californians. Managing and allocating this resource is a complex feat of economics, politics, and engineering, made increasingly contentious by the ongoing drought. The objective of this research is to augment the scientific foundation of management decisions by addressing the question of how flows into the Delta have evolved in response to human intervention since 1850. In particular, quantifying the dynamic components of water usage through vegetative uptake and evapotranspiration, groundwater recharge, flood conveyance, and water exports at incremental levels of development is a key ambition. This approach emphasizes the built environment, which is subject to the local regulatory framework, rather than climate change, which is generally considered immovable without united global effort. This work encompasses the creation of a hydrologic model representing the watersheds of the San Francisco Bay-Delta system, and quantifies the impacts of changes in land use and the gradual construction of levees, reservoirs, and diversion infrastructure. The model is run using the same climatological forcing at each level of development, thus elucidating the effects of local anthropogenic activity on the Delta and the inflows to the San Francisco Bay estuary. Our results provide a timeline of change, giving decision-makers a scientifically established baseline to aid in the sustainable management of the Bay-Delta system.

  2. The Evergreen basin and the role of the Silver Creek fault in the San Andreas fault system, San Francisco Bay region, California

    Science.gov (United States)

    Jachens, Robert C.; Wentworth, Carl M.; Graymer, Russell W.; Williams, Robert; Ponce, David A.; Mankinen, Edward A.; Stephenson, William J.; Langenheim, Victoria

    2017-01-01

    The Evergreen basin is a 40-km-long, 8-km-wide Cenozoic sedimentary basin that lies mostly concealed beneath the northeastern margin of the Santa Clara Valley near the south end of San Francisco Bay (California, USA). The basin is bounded on the northeast by the strike-slip Hayward fault and an approximately parallel subsurface fault that is structurally overlain by a set of west-verging reverse-oblique faults which form the present-day southeastward extension of the Hayward fault. It is bounded on the southwest by the Silver Creek fault, a largely dormant or abandoned fault that splays from the active southern Calaveras fault. We propose that the Evergreen basin formed as a strike-slip pull-apart basin in the right step from the Silver Creek fault to the Hayward fault during a time when the Silver Creek fault served as a segment of the main route by which slip was transferred from the central California San Andreas fault to the Hayward and other East Bay faults. The dimensions and shape of the Evergreen basin, together with palinspastic reconstructions of geologic and geophysical features surrounding it, suggest that during its lifetime, the Silver Creek fault transferred a significant portion of the ∼100 km of total offset accommodated by the Hayward fault, and of the 175 km of total San Andreas system offset thought to have been accommodated by the entire East Bay fault system. As shown previously, at ca. 1.5–2.5 Ma the Hayward-Calaveras connection changed from a right-step, releasing regime to a left-step, restraining regime, with the consequent effective abandonment of the Silver Creek fault. This reorganization was, perhaps, preceded by development of the previously proposed basin-bisecting Mount Misery fault, a fault that directly linked the southern end of the Hayward fault with the southern Calaveras fault during extinction of pull-apart activity. Historic seismicity indicates that slip below a depth of 5 km is mostly transferred from the Calaveras

  3. Examen de auditoría integral al Gobierno Autónomo Descentralizado Parroquial Rural de San Francisco de Sigsipamba

    OpenAIRE

    Lomas Paz, Rita Lucía

    2014-01-01

    La investigación realizada de auditoría integral al Gobierno Autónomo Descentralizado Parroquial Rural de San Francisco de Sigsipamba, se desarrolló considerando la planificación que está encaminada al análisis del control interno; al cumplimiento de las disposiciones legales, y demás normas aplicables en la entidad; y de las metas u objetivos propuestos, además determinará la razonabilidad de las cifras de los estados financieras, investigación que servirá de herramienta para mejorar los sis...

  4. Don’t Work, Work at Home, or Commute? Discrete Choice Models of the Decision for San Francisco Bay Area Residents

    OpenAIRE

    Ory, D T; Mokhtarian, Patricia L

    2005-01-01

    Using socio-demographic, personality, and attitudinal data from 1,680 residents of the San Francisco Bay Area, we develop and estimate binary, multinomial, and nested logit models of the choice to work or not, whether or not to work at home, and whether to commute all of the time or some of the time (either by only working part time, or by working a compressed work week, or by telecommuting some of the time). To our knowledge, these are the first models of all these choices simultaneously. Th...

  5. The Impact of Antiretroviral Therapy in a Cohort of HIV Infected Patients Going in and out of the San Francisco County Jail

    OpenAIRE

    Pant Pai, Nitika; Estes, Milton; Moodie, Erica E. M.; Reingold, Arthur L.; Tulsky, Jacqueline P.

    2009-01-01

    Background Jails are an important venue of HIV care and a place for identification, treatment and referral for care. HIV infected inmates in the San Francisco County jail are offered antiretroviral treatment (ART), which many take only while in jail. We evaluated the effect of ART administration in a cohort of jail inmates going in and out of jail over a nine year period. Methodology/Principal Findings In this retrospective study, we examined inmates with HIV going in and out of jail. Inmates...

  6. Interscience Conference on Antimicrobial Agents and Chemotherapy--49th annual meeting. Part 2. 12-15 September 2009, San Francisco, CA, USA.

    Science.gov (United States)

    Turner, Ben; Murch, Lisa

    2009-11-01

    The Interscience Conference on Antimicrobial Agents and Chemotherapy held in San Francisco included topics covering new therapeutic developments for the treatment of infectious diseases. This conference report highlights selected presentations on several antibiotics in development including a broad-spectrum penem beta-lactam antibiotic, a novel siderophore monobactam, as well as other novel antibiotics. Investigational drugs discussed include sulopenem and sulopenem etzadroxil (both Pfizer Inc), BAL-30072 (Basilea Pharmaceutica International Ltd), TP-120 and TP-787 (both Tetraphase Pharmaceuticals Inc), NAI-107 (New Anti Infectives Consortium/NexThera Biosciences) and ABI-200 (AdRem Biotech/US Department of Agriculture).

  7. Diet, Prey Selection, and Body Condition of Age-0 Delta Smelt, Hypomesus transpacificus, in the Upper San Francisco Estuary

    Directory of Open Access Journals (Sweden)

    Steven B. Slater

    2014-09-01

    Full Text Available Steven B. Slater and Randall D. Baxterdoi: http://dx.doi.org/10.15447/sfews.2014v12iss3art1The Delta Smelt, an endangered fish, has suffered a long-term decline in abundance, believed to result from, in part, to changes in the pelagic food web of the upper San Francisco Estuary. To investigate the current role of food as a factor in Delta Smelt well-being, we developed reference criteria for gut fullness and body condition based on allometric growth. We then examined monthly diet, prey selectivity, and gut fullness of larvae and juvenile Delta Smelt collected April through September in 2005 and 2006 for evidence of feeding difficulties leading to reduced body condition. Calanoid copepods Eurytemora affinis and Pseudodiaptomus forbesi remained major food items during spring and from early summer through fall, respectively. Other much larger copepods and macroinvertebrates contributed in lesser numbers to the diet of older juvenile fish from mid-summer through fall. In fall, juvenile Delta Smelt periodically relied heavily on very small prey and prey potentially associated with demersal habitat, suggesting typical pelagic food items were in short supply. We found a strong positive selection for E. affinis and P. forbesi, neutral to negative selection for evasive calanoid Sinocalanus doerrii, and neutral to negative selection for the small cyclopoid copepod Limnoithona tetraspina and copepod nauplii, which were consumed only when extremely numerous in the environment. Feeding incidence was significantly higher in 2006, but among successfully feeding fish we found no between year difference in gut fullness. However, we did detect differences in fullness across months in both years. We found no difference in body condition of Delta Smelt between years yet our sample sizes were low in September when Delta Smelt reverted to feeding on very small organisms and fullness declined, so the longer-term effect remains unknown. Our findings suggest that: Delta

  8. The role of habitat-selection in restricting invasive blue mussel advancement to protect native populations in San Francisco Bay

    Science.gov (United States)

    Mittal, N.; Saarman, N. P.; Pogson, G.

    2013-12-01

    Introduced species contribute to decline of biodiversity and ecosystem services. Introduced species threaten native species by increasing competition for space and resources, changing their habitat, and disrupting species interactions. Protecting native species is crucial to preserving ecosystem services (i.e. medicinal, agricultural, ecological, and cultural benefits) for future generations. In marine communities, the number of invasive species is dramatically increasing every year, further magnifying the negative impact on native species. This research determines if habitat-specific selection can protect native species from their invasive relatives, and could allow targeted habitat restoration for native species to maintain high levels of biodiversity. Blue mussels provide an ideal system for studying the impact of an invasive species (Mytilus galloprovincialis) on native mussels (M. trossulus), because M. galloprovincialis is marked as one of the world's 100 worst invasive species. Hybridization between M. galloprovincialis and M. trossulus occurs wherever their distributions overlap (i.e. Japan, Puget Sound, and central California). In central California, hybrids form in a broad variety of habitats ever since M. galloprovincialis was introduced about 100 years ago. The current level of threat posed to native mussels in central California is unknown. When population growth rate of an invasive species is higher than the native within a hybrid zone, the invader's genes become more prominent in the hybrids than the native species' genes. This uneven mix of genes and decrease of pure native mussels threatens to drive M. trossulus to extinction. Therefore, it is important to research which environment fosters highest success of pure native species. We conducted a field experiment in San Francisco Bay where mussels were reared in different habitats. We then collected samples and extracted DNA from each treatment, and genotyped them by a next-generation sequencing

  9. Greenhouse Gas Source Detection and Attribution in the San Francisco Bay Area of California Using a Mobile Measurement Platform

    Science.gov (United States)

    Martien, P. T.; Guha, A.; Newman, S.; Young, A.; Bower, J.; Perkins, I.; Randall, S.; Stevenson, E.; Hilken, H.

    2017-12-01

    The Bay Area Air Quality Management District, the San Francisco Bay Area's air quality regulatory agency, has set a goal to reduce the region's greenhouse gas (GHG) emissions 80% below 1990 levels by 2050, consistent with the State of California's climate goals. Recently, the Air District's governing board adopted a 2017 Clean Air Plan advancing the agency's vision and including actions to put the region on a path to achieving the 2050 goal while also reducing air pollution and related health impacts. The Plan includes GHG rule-making efforts, policy initiatives, local government partnerships, outreach, grants and incentives, encompassing over 250 specific implementation actions across all economic sectors to effect ambitious emission reductions in the region. To support the 2017 Plan, the Air District has built a mobile measurement platform (GHG research van) to perform targeted CH4 emissions hotspot detection and source attribution. Instruments in the van measure CH4, CO2 and N2O in ambient plumes. Coincident measurements of source tracers like isotopic methane (13C - CH4), CO and ethane (C2H6) provide the capability to distinguish between biogenic, combustion-based and fossil-based fugitive methane sources. We report observations of CH4 plumes from source-specific measurements in and around facilities including a wastewater treatment plant, a composting operation, a waste-to-energy anaerobic digestion plant and a few refineries. We performed leak surveys inside several electric utility-operated facilities including a power plant and an underground natural gas storage facility. We sampled exhaust from a roadway tunnel and computed fleet-averaged automobile-related CH4 and N2O emission factors. We used tracer-to-tracer emission ratios to create chemical signatures of emissions from each sampled source category. We compare measurement-based ratios with those used to derive the regional GHG inventory. Data from these and other sources will lead to an improved

  10. A novel method to develop an otolith microchemistry model to determine striped bass habitat use in the San Francisco Estuary

    Energy Technology Data Exchange (ETDEWEB)

    Phillis, C C; Ostrach, D J; Gras, M; Yin, Q; Ingram, B L; Zinkl, J G; Weber, P K

    2006-06-14

    Otolith Sr/Ca has become a popular tool for hind casting habitat utilization and migration histories of euryhaline fish. It can readily identify habitat shifts of diadromous fish in most systems. Inferring movements of fish within estuarine habitat, however, requires a model of that accounts of the local water chemistry and the response of individual species to that water chemistry, which is poorly understood. Modeling is further complicated by the fact that high marine Sr and Ca concentrations results in a rapid, nonlinear increase in water Sr/Ca and {sup 87}Sr/{sup 86}Sr between fresh and marine waters. Here we demonstrate a novel method for developing a salinity-otolith Sr/Ca model for the purpose of reconstructing striped bass (Morone saxatilis) habitat use in the San Francisco Bay estuary. We used correlated Sr/Ca and {sup 87}Sr/{sup 86}Sr ratios measurements from adult otoliths from striped bass that experienced a range of salinities to infer striped bass otolith Sr/Ca response to changes in salinity and water Sr/Ca ratio. Otolith {sup 87}Sr/{sup 86}Sr can be assumed to accurately record water {sup 87}Sr/{sup 86}Sr because there is no biological fractionation of Sr isotopes. Water {sup 87}Sr/{sup 86}Sr can in turn be used to estimate water salinity based on the mixing of fresh and marine water with known {sup 87}Sr/{sup 86}Sr ratios. The relationship between adjacent analyses on otoliths of Sr/Ca and {sup 87}Sr/{sup 86}Sr by LA-ICP-MS and MC-ICP-MS (r{sup 2} = 0.65, n = 66) is used to predict water salinity from a measured Sr/Ca ratio. The nature of this non-linear model lends itself well to identifying residence in the Delta and to a lesser extent Suisun Bay, but does not do well locating residence within the more saline bays west of Carquinez Strait. An increase in the number of analyses would improve model confidence, but ultimately the precision of the model is limited by the variability in the response of individual fish to water Sr/Ca.

  11. Distribution of creep in the northern San Francisco Bay Area illuminated by repeating earthquakes and InSAR

    Science.gov (United States)

    Funning, G.; Shakibay Senobari, N.; Swiatlowski, J. L.

    2017-12-01

    Surface observations of fault creep in the region north of San Francisco Bay are sporadic. While there are long-standing instances of creep-affected infrastructure on the Maacama and Bartlett Springs faults, the lateral and depth extents of creep on these and other faults in the region remain a question. Here, we supplement this sparse existing observation set with additional information from repeating earthquake sequences (REs) and InSAR, to illuminate, and significantly improve our knowledge of, creep across the region. Repeating earthquakes have long been considered indicators of creep on faults. We present the results of an extensive similarity search through over 600,000 archived waveforms from 43,000 events using a fast algorithm; from this we can identify 39 periodic repeating sequences and over 80 nonperiodic repeated event groups. We compare these with decadal line-of-sight velocity measurements made by applying the StaMPS time series InSAR code to ERS and Envisat data covering the region, that can be used to identify surface creep on faults. On the Rodgers Creek, Maacama and Bartlett Springs faults, both InSAR and REs show corroborating evidence for creep at locations where it was previously inferred. The REs additionally provide information on its depth extent. On the Maacama fault, we find REs extending almost to the southern limit of the mapped fault trace, south of Cloverdale, suggesting that creep may be pervasive on the fault. We can also identify structural complexity both in the stepover region with the Rodgers Creek fault, and in the northern segment of the fault close to Willits, potentially indicating parallel and/or down-dip branching creeping structures in both locations. REs on the Bartlett Springs fault indicate creep that extends across the full down-dip width of the brittle fault; here the proximity of InSAR creep rate estimates and a shallow RE sequence may permit a calibration of the RE `creepmeter', allowing us to estimate creep rates

  12. Ambient Greenhouse Gas (GHG) Observations in the San Francisco Bay Area of California Using a Fixed-site Monitoring Network

    Science.gov (United States)

    Martien, P. T.; Guha, A.; Bower, J.; Perkins, I.; Randall, S.; Young, A.; Hilken, H.; Stevenson, E.

    2016-12-01

    The Bay Area Air Quality Management District is the greater San Francisco Bay metropolitan area's chief air quality regulatory agency. Aligning itself with the Governor's Executive Order S-3-05, the Air District has set a goal to reduce the region's GHG emissions by 80% below 1990 levels by the year 2050. The Air District's 2016 Clean Air Plan will lay out the agency's vision and actions to put the region on a path forward towards achieving the 2050 goal while also reducing air pollution and related health impacts. The 2016 Plan has three overarching objectives: 1) develop a multi-pollutant emissions control strategy, (2) reduce population exposure to harmful air pollutants, especially in vulnerable communities, and (3) protect climate through a comprehensive Regional Climate Protection Strategy. To accomplish one of 2016 Plan's control measures (SL3 - Greenhouse Gas Monitoring and Measurement Network), the Air District has set up a long-term, ambient GHG monitoring network at four sites. The first site is located north and upwind of the urban core at Bodega Bay by the Pacific Coast. It mostly receives clean marine inflow and serves as the regional background site. The other three sites are strategically located at regional exit points for Bay Area plumes that presumably contain well-mixed GHG enhancements from local sources. CO2 and CH4are being measured continuously at the fixed-sites, along with combustion tracer CO and other air pollutants. In the longer term, the network will allow the Air District to monitor ambient concentrations of GHGs and thus evaluate the effectiveness of its policy, regulation and enforcement efforts. We present data trends from the first year of operation of the fixed-site monitoring network including monthly and seasonal patterns, diurnal variations and regional enhancements at individual sites above background concentrations. We also locate an isotopic methane instrument (Picarro, G132-i) for a short duration (a week) at each of the

  13. The Rhizosphere Zone: A Hot Spot of Microbial Activity and Methylmercury Production in Saltmarsh Sediments of San Francisco Bay, California

    Science.gov (United States)

    Windham-Myers, L.; Marvin-Dipasquale, M.; Voytek, M.; Kirshtein, J.; Krabbenhoft, D. P.; Agee, J. L.; Cox, M.; Kakouros, E.; Collins, J. N.; Yee, D.

    2008-12-01

    Tidal marshes of varying hydrology and salinity have been shown to have high rates of microbial methylmercury (MeHg) production, especially the periodically flooded, higher elevations which are densely vegetated with shallowly rooted plants. The specific influence of emergent wetland plants and their active rhizosphere (root zone) on mercury (Hg) biogeochemistry, however, is poorly understood. Seasonal and spatial patterns of Hg biogeochemistry were examined in 2005 and 2006 at three marshes along a salinity gradient of the Petaluma River, in Northern San Francisco Bay, California. In addition, to directly examine the influence of rhizosphere activity on MeHg production, a suite of devegetation experiments was conducted in 2006 within each marsh using paired vegetated and devegetated plots in two marsh subhabitats: poorly- drained interior sites and well-drained "edge" sites near slough channels. Surface sediment (0-2cm) was sampled in both April and August from these plots, as well as from 1st and 3rd order slough channels that were naturally free of vegetation. Vegetated marsh sites produced 3- to19-fold more MeHg than did slough sites, and MeHg production rates were greater in marsh interior sites compared to more oxic marsh "edge" sites. Microbial biomass (ng DNA gdrysed) was greater in vegetated marsh settings, compared to slough channels, and increased significantly between April and August at all marsh sites. Despite this seasonal increase in microbial biomass, MeHg concentrations and production rates decreased from April to August in vegetated surface sediments. Microbial indicators of methylation also decreased from April to August, including rates of microbial sulfate reduction and the abundance of iron- and sulfate- reducing bacterial DNA. Results from the devegetated plots suggest that root exudation of fermentative labile carbon to surface soils is responsible for the higher microbial biomass, and the higher relative abundance of iron- and sulfate

  14. Rainfall Estimation and Performance Characterization Using an X-band Dual-Polarization Radar in the San Francisco Bay Area

    Science.gov (United States)

    Cifelli, R.; Chen, H.; Chandra, C. V.

    2016-12-01

    The San Francisco Bay area is home to over 5 million people. In February 2016, the area also hosted the NFL Super bowl, bringing additional people and focusing national attention to the region. Based on the El Nino forecast, public officials expressed concern for heavy rainfall and flooding with the potential for threats to public safety, costly flood damage to infrastructure, negative impacts to water quality (e.g., combined sewer overflows) and major disruptions in transportation. Mitigation of the negative impacts listed above requires accurate precipitation monitoring (quantitative precipitation estimation-QPE) and prediction (including radar nowcasting). The proximity to terrain and maritime conditions as well as the siting of existing NEXRAD radars are all challenges in providing accurate, short-term near surface rainfall estimates in the Bay area urban region. As part of a collaborative effort between the National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory, Colorado State University (CSU), and Santa Clara Valley Water District (SCVWD), an X-band dual-polarization radar was deployed in Santa Clara Valley in February of 2016 to provide support for the National Weather Service during the Super Bowl and NOAA's El Nino Rapid Response field campaign. This high-resolution radar was deployed on the roof of one of the buildings at the Penitencia Water Treatment Plant. The main goal was to provide detailed precipitation information for use in weather forecasting and assists the water district in their ability to predict rainfall and streamflow with real-time rainfall data over Santa Clara County especially during a potentially large El Nino year. The following figure shows the radar's coverage map, as well as sample reflectivity observations on March 06, 2016, at 00:04UTC. This paper presents results from a pilot study from February, 2016 to May, 2016 demonstrating the use of X-band weather radar for quantitative precipitation

  15. Phytoplankton bloom dynamics in coastal ecosystems: A review with some general lessons from sustained investigation of San Francisco Bay, California

    Science.gov (United States)

    Cloern, James E.

    1996-05-01

    Phytoplankton blooms are prominent features of biological variability in shallow coastal ecosystems such as estuaries, lagoons, bays, and tidal rivers. Long-term observation and research in San Francisco Bay illustrates some patterns of phytoplankton spatial and temporal variability and the underlying mechanisms of this variability. Blooms are events of rapid production and accumulation of phytoplankton biomass that are usually responses to changing physical forcings originating in the coastal ocean (e.g., tides), the atmosphere (wind), or on the land surface (precipitation and river runoff). These physical forcings have different timescales of variability, so algal blooms can be short-term episodic events, recurrent seasonal phenomena, or rare events associated with exceptional climatic or hydrologic conditions. The biogeochemical role of phytoplankton primary production is to transform and incorporate reactive inorganic elements into organic forms, and these transformations are rapid and lead to measurable geochemical change during blooms. Examples include the depletion of inorganic nutrients (N, P, Si), supersaturation of oxygen and removal of carbon dioxide, shifts in the isotopic composition of reactive elements (C, N), production of climatically active trace gases (methyl bromide, dimethylsulfide), changes in the chemical form and toxicity of trace metals (As, Cd, Ni, Zn), changes in the biochemical composition and reactivity of the suspended particulate matter, and synthesis of organic matter required for the reproduction and growth of heterotrophs, including bacteria, zooplankton, and benthic consumer animals. Some classes of phytoplankton play special roles in the cycling of elements or synthesis of specific organic molecules, but we have only rudimentary understanding of the forces that select for and promote blooms of these species. Mounting evidence suggests that the natural cycles of bloom variability are being altered on a global scale by human

  16. Producción y comercialización de artículos de cuero en la asociación san francisco. Estrategias para mejorar la productividad y competitividad.

    OpenAIRE

    Galindo Játiva, Ruth Marlene

    2014-01-01

    1. Evaluar los procesos de producción y comercialización de los artículos de cuero de la Asociación de pequeños productores y comerciantes San Francisco, en la ciudad de Cotacachi, para determinar la situación actual. 2. Mejorar la productividad y competitividad en la Asociación de pequeños productores y comerciantes San Francisco, en la ciudad de Cotacachi, para optimizar la producción y comercialización de artículos de cuero. El presente trabajo de investigación sobre las estrategias ...

  17. Sediment transport patterns in the San Francisco Bay Coastal System from cross-validation of bedform asymmetry and modeled residual flux

    Science.gov (United States)

    Barnard, Patrick L.; Erikson, Li H.; Elias, Edwin P.L.; Dartnell, Peter; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    The morphology of ~ 45,000 bedforms from 13 multibeam bathymetry surveys was used as a proxy for identifying net bedload sediment transport directions and pathways throughout the San Francisco Bay estuary and adjacent outer coast. The spatially-averaged shape asymmetry of the bedforms reveals distinct pathways of ebb and flood transport. Additionally, the region-wide, ebb-oriented asymmetry of 5% suggests net seaward-directed transport within the estuarine-coastal system, with significant seaward asymmetry at the mouth of San Francisco Bay (11%), through the northern reaches of the Bay (7–8%), and among the largest bedforms (21% for λ > 50 m). This general indication for the net transport of sand to the open coast strongly suggests that anthropogenic removal of sediment from the estuary, particularly along clearly defined seaward transport pathways, will limit the supply of sand to chronically eroding, open-coast beaches. The bedform asymmetry measurements significantly agree (up to ~ 76%) with modeled annual residual transport directions derived from a hydrodynamically-calibrated numerical model, and the orientation of adjacent, flow-sculpted seafloor features such as mega-flute structures, providing a comprehensive validation of the technique. The methods described in this paper to determine well-defined, cross-validated sediment transport pathways can be applied to estuarine-coastal systems globally where bedforms are present. The results can inform and improve regional sediment management practices to more efficiently utilize often limited sediment resources and mitigate current and future sediment supply-related impacts.

  18. Census Cities experiment in urban change detection. [mapping of land use changes in San Francisco, Washington D.C., Phoenix, Tucson, Boston, New Haven, Cedar Rapids, and Pontiac

    Science.gov (United States)

    Wray, J. R. (Principal Investigator); Milazzo, V. A.

    1974-01-01

    The author has identified the following significant results. Mapping of 1970 and 1972 land use from high-flight photography has been completed for all test sites: San Francisco, Washington, Phoenix, Tucson, Boston, New Haven, Cedar Rapids, and Pontiac. Area analysis of 1970 and 1972 land use has been completed for each of the mandatory urban areas. All 44 sections of the 1970 land use maps of the San Francisco test site have been officially released through USGS Open File at 1:62,500. Five thousand copies of the Washington one-sheet color 1970 land use map, census tract map, and point line identification map are being printed by USGS Publication Division. ERTS-1 imagery for each of the eight test sites is being received and analyzed. Color infrared photo enlargements at 1:100,000 of ERTS-1 MSS images of Phoenix taken on October 16, 1972 and May 2, 1973 are being analyzed to determine to what level land use and land use changes can be identified and to what extent the ERTS-1 imagery can be used in updating the 1970 aircraft photo-derived land use data base. Work is proceeding on the analysis of ERTS-1 imagery by computer manipulation of ERTS-1 MSS data in digital format. ERTS-1 CCT maps at 1:24,000 are being analyzed for two dates over Washington and Phoenix. Anniversary tape sets have been received at Purdue LARS for some additional urban test sites.

  19. Integration of bed characteristics, geochemical tracers, current measurements, and numerical modeling for assessing the provenance of beach sand in the San Francisco Bay Coastal System

    Science.gov (United States)

    Barnard, Patrick L.; Foxgrover, Amy C.; Elias, Edwin P.L.; Erikson, Li H.; Hein, James R.; McGann, Mary; Mizell, Kira; Rosenbauer, Robert J.; Swarzenski, Peter W.; Takesue, Renee K.; Wong, Florence L.; Woodrow, Donald L.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    Over 150 million m3 of sand-sized sediment has disappeared from the central region of the San Francisco Bay Coastal System during the last half century. This enormous loss may reflect numerous anthropogenic influences, such as watershed damming, bay-fill development, aggregate mining, and dredging. The reduction in Bay sediment also appears to be linked to a reduction in sediment supply and recent widespread erosion of adjacent beaches, wetlands, and submarine environments. A unique, multi-faceted provenance study was performed to definitively establish the primary sources, sinks, and transport pathways of beach-sized sand in the region, thereby identifying the activities and processes that directly limit supply to the outer coast. This integrative program is based on comprehensive surficial sediment sampling of the San Francisco Bay Coastal System, including the seabed, Bay floor, area beaches, adjacent rock units, and major drainages. Analyses of sample morphometrics and biological composition (e.g., Foraminifera) were then integrated with a suite of tracers including 87Sr/86Sr and 143Nd/144Nd isotopes, rare earth elements, semi-quantitative X-ray diffraction mineralogy, and heavy minerals, and with process-based numerical modeling, in situ current measurements, and bedform asymmetry to robustly determine the provenance of beach-sized sand in the region.

  20. Avian communities in tidal salt marshes of San Francisco Bay: a review of functional groups by foraging guild and habitat association

    Science.gov (United States)

    Takekawa, John Y.; Woo, Isa; Gardiner, Rachel J.; Casazza, Michael L.; Ackerman, Joshua T.; Nur, Nadav; Liu, Leonard; Spautz, Hildie; Palaima, Arnas

    2011-01-01

    The San Francisco Bay estuary is highly urbanized, but it supports the largest remaining extent of tidal salt marshes on the west coast of North America as well as a diverse native bird community. San Francisco Bay tidal marshes are occupied by more than 113 bird species that represent 31 families, including five subspecies from three families that we denote as tidal-marsh obligates. To better identify the niche of bird species in tidal marshes, we present a review of functional groups based on foraging guilds and habitat associations. Foraging guilds describe the method by which species obtain food from tidal marshes, while habitat associations describe broad areas within the marsh that have similar environmental conditions. For example, the ubiquitous song sparrows (Alameda Melospiza melodia pusillula, Suisun M. m. maxillaris, and San Pablo M. m. samuelis) are surface-feeding generalists that consume prey from vegetation and the ground, and they are found across the entire marsh plain into the upland–marsh transition. In contrast, surface-feeding California black rails (Laterallus jamaicensis coturniculus) are cryptic, and generally restricted in their distribution to the mid- and high-marsh plain. Although in the same family, the endangered California clapper rail (Rallus longirostris obsoletus) has become highly specialized, foraging primarily on benthic fauna within marsh channels when they are exposed at low tide. Shorebirds such as the black-necked stilt (Himantopus mexicanus) typically probe in mud flats to consume macroinvertebrate prey, and are generally restricted to foraging on salt pans within the marsh plain, in ponds, or on mud flats during transitional stages of marsh evolution. The abundance and distribution of birds varies widely with changing water depths and vegetation colonization during different stages of restoration. Thus, tidal-marsh birds represent a rich and diverse community in bay marshes, with niches that may be distinguished by the

  1. A Global Talent Magnet: How a San Francisco/Bay Area Global Higher Education Hub Could Advance California's Comparative Advantage in Attracting International Talent and Further Build US Economic Competitiveness. Research & Occasional Paper Series: CSHE.9.11

    Science.gov (United States)

    Douglass, John; Edelstein, Richard; Hoareau, Cecile

    2011-01-01

    During the 2009-10 academic year international students generated more than $18.8 billion in net income into the US economy. California alone had nearly 100,000 international students with an economic impact of nearly $3.0 billion. In this paper, we outline a strategy for the San Francisco/Bay Area to double the number of international students…

  2. Stable hydrogen and oxygen isotopes of tap water reveal structure of the San Francisco Bay Area's water system and adjustments during a major drought.

    Science.gov (United States)

    Tipple, Brett J; Jameel, Yusuf; Chau, Thuan H; Mancuso, Christy J; Bowen, Gabriel J; Dufour, Alexis; Chesson, Lesley A; Ehleringer, James R

    2017-08-01

    Water availability and sustainability in the Western United States is a major flashpoint among expanding communities, growing industries, and productive agricultural lands. This issue came to a head in 2015 in the State of California, when the State mandated a 25% reduction in urban water use following a multi-year drought that significantly depleted water resources. Water demands and challenges in supplying water are only expected to intensify as climate perturbations, such as the 2012-2015 California Drought, become more common. As a consequence, there is an increased need to understand linkages between urban centers, water transport and usage, and the impacts of climate change on water resources. To assess if stable hydrogen and oxygen isotope ratios could increase the understanding of these relationships within a megalopolis in the Western United States, we collected and analyzed 723 tap waters across the San Francisco Bay Area during seven collection campaigns spanning 21 months during 2013-2015. The San Francisco Bay Area was selected as it has well-characterized water management strategies and the 2012-2105 California Drought dramatically affected its water resources. Consistent with known water management strategies and previously collected isotope data, we found large spatiotemporal variations in the δ 2 H and δ 18 O values of tap waters within the Bay Area. This is indicative of complex water transport systems and varying municipality-scale management decisions. We observed δ 2 H and δ 18 O values of tap water consistent with waters originating from snowmelt from the Sierra Nevada Mountains, local precipitation, ground water, and partially evaporated reservoir sources. A cluster analysis of the isotope data collected in this study grouped waters from 43 static sampling sites that were associated with specific water utility providers within the San Francisco Bay Area and known management practices. Various management responses to the drought, such as

  3. Affective foodscapes in an economy of passion : repetition, opposition and adaptation in Mexican restaurants in Amsterdam, Madrid and San Francisco

    NARCIS (Netherlands)

    Matus Ruiz, M.

    2012-01-01

    The
 main
 goal
 of
 my
 research
 was
 to
 analyze
 how
 the
 desire
 to
 affect
 and
 be
 affected
 by
 foreign
 signs
relates
 to
 the
 commoditization
 of
 food
 products
 offered
 in
 Mexican
 restaurants
 in
 Amsterdam,
 Madrid
and
 San
 Francisco.
 I
 conceive
 restaurants
 as


  4. Status and understanding of groundwater quality in the San Francisco Bay groundwater basins, 2007—California GAMA Priority Basin Project

    Science.gov (United States)

    Parsons, Mary C.; Kulongoski, Justin T.; Belitz, Kenneth

    2013-01-01

    Groundwater quality in the approximately 620-square-mile (1,600-square-kilometer) San Francisco Bay study unit was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is located in the Southern Coast Ranges of California, in San Francisco, San Mateo, Santa Clara, Alameda, and Contra Costa Counties. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory. The GAMA San Francisco Bay study was designed to provide a spatially unbiased assessment of the quality of untreated groundwater within the primary aquifer system, as well as a statistically consistent basis for comparing water quality throughout the State. The assessment is based on water-quality and ancillary data collected by the USGS from 79 wells in 2007 and is supplemented with water-quality data from the California Department of Public Health (CDPH) database. The primary aquifer system is defined by the depth interval of the wells listed in the CDPH database for the San Francisco Bay study unit. The quality of groundwater in shallower or deeper water-bearing zones may differ from that in the primary aquifer system; shallower groundwater may be more vulnerable to surficial contamination. The first component of this study, the status of the current quality of the groundwater resource, was assessed by using data from samples analyzed for volatile organic compounds (VOCs), pesticides, and naturally occurring inorganic constituents, such as major ions and trace elements. Water- quality data from the CDPH database also were incorporated for this assessment. This status assessment is intended to characterize the quality of groundwater resources within the primary aquifer system of the San Francisco Bay study unit, not the treated drinking water delivered to consumers by water

  5. Interview with René Yáñez, artist, co-founder of the Galería de la Raza, San Francisco, CA, USA, August 13, 2001 Entretien avec René Yáñez, artiste, co-fondateur de la Galería de la Raza, San Francisco, CA, Etats-Unis

    Directory of Open Access Journals (Sweden)

    Gérard Selbach

    2009-10-01

    Full Text Available René Yáñez is an all-round visual artist and visionary, now in his sixties. He came out of the Chicano movement of the 70’s and was instrumental in founding the Galería de la Raza in the Mission district of San Francisco. He remained some fifteen years as its director, curating exhibitions, directing and promoting emerging artists of all kinds. He then worked as director of cultural programming at the Mexican Museum until its closure. René Yáñez co-produced Mexican performance artist Astrid H...

  6. Interview with Jennie E. Rodríguez, Executive Director of the Mission Cultural Center for Latino Arts, San Francisco, CA, USA, August 15, 2001 Entretien avec Jennie E. Rodríguez, directrice, Mission Cultural Center for Latino Arts, San Francisco, CA, États-Unis

    Directory of Open Access Journals (Sweden)

    Gérard Selbach

    2009-10-01

    Full Text Available ForewordThe Mission Cultural Center for Latino Arts (MCCLA is located at 2868 Mission Street in San Francisco, in a district mainly inhabited by Hispanics and well-known for its numerous murals. The Center was founded in 1977 by artists and community activists who shared “the vision to promote, preserve and develop the Latino cultural arts that reflect the living tradition and experiences of Chicano, Central and South American, and Caribbean people.”August 2001 was as busy at the Center as a...

  7. MODELADO DE PARTÍCULAS PM10 Y PM2.5 MEDIANTE REDES NEURONALES ARTIFICIALES SOBRE CLIMA TROPICAL DE SAN FRANCISCO DE CAMPECHE, MÉXICO

    Directory of Open Access Journals (Sweden)

    Alberto Antonio Espinosa Guzmán

    Full Text Available In this paper, a computational methodology based on Artificial Neural Networks (ANN was developed to estimate the index of PM10 and PM2.5 concentration in air of San Francisco de Campeche city. A three layer ANN architecture was trained using an experimental database composed by days of the week, time of day, ambient temperature, atmospheric pressure, wind speed, wind direction, relative humidity, and solar radiation. The best ANN architecture, composed by 30 neurons in hidden layer, was obtained using the Levenberg-Marquardt (LM optimization algorithm, logarithmic sigmoid and linear transfer functions. Model results generate predictions with a determination coefficient of 93.01% and 90.10% for PM2.5 and PM10, respectively. The proposed methodology can be implemented in several studies as public health, environmental studies, urban development, and degradation of historical monuments.

  8. A probable prehistoric case of meningococcal disease from San Francisco Bay: Next generation sequencing of Neisseria meningitidis from dental calculus and osteological evidence.

    Science.gov (United States)

    Eerkens, Jelmer W; Nichols, Ruth V; Murray, Gemma G R; Perez, Katherine; Murga, Engel; Kaijankoski, Phil; Rosenthal, Jeffrey S; Engbring, Laurel; Shapiro, Beth

    2018-05-25

    Next Generation Sequencing (NGS) of ancient dental calculus samples from a prehistoric site in San Francisco Bay, CA-SCL-919, reveals a wide range of potentially pathogenic bacteria. One older adult woman, in particular, had high levels of Neisseria meningitidis and low levels of Haemophilus influenzae, species that were not observed in the calculus from three other individuals. Combined with the presence of incipient endocranial lesions and pronounced meningeal grooves, we interpret this as an ancient case of meningococcal disease. This disease afflicts millions around the globe today, but little is known about its (pre)history. With additional sampling, we suggest NGS of calculus offers an exciting new window into the evolutionary history of these bacterial species and their interactions with humans. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Transcribed sequences in the human genome to be held in San Francisco, November 7 and 8, 1992. Final report, September 1, 1992--August 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Gardiner, K.

    1993-11-01

    The Second International Workshop on the Identification of Transcribed Sequences was held in San Francisco on November 7--8, 1992. The purpose of the workshop was to discuss and evaluate techniques for developing a complete transcriptional map of the human genome. Such a map requires the positions, sequences, and expression patterns of all genes. This goal is being approached from two different directions, each with strengths and weaknesses. One method is to identify the transcribed sequences from genomic DNA of a given region; the other is to systematically sequence and map cDNAs. The cDNA approach yields sequence information rapidly, but mapping each cDNA is a technical challenge. In the first approach, the map locations of genomic sequences are known at the outset, and the challenge is to identify exons. The efficient construction of a transcriptional map will require a diverse array of techniques.

  10. La Basílica de San Francisco de Asís después del terremoto del 26 de septiembre de 1997

    Directory of Open Access Journals (Sweden)

    Giorgio Croci

    1998-12-01

    Full Text Available La Basílica de San Francisco de Asís, gravemente dañada tras los primeros terremotos de otoño de 1997, amenazaba con un colapso completo a raíz del estado de difícil equilibrio en que había quedado. La intervención descrita en este artículo explica cómo se pudo consolidar el templo dañado en tiempo récord, poco antes de un seísmo fortísimo que habría provocado con seguridad el derrumbamiento de gran parte de su cubierta, con la grave pérdida que este hecho hubiera supuesto para el patrimonio arquitectónico y la historia del arte italiana.

  11. A report from the 2011 annual meeting of the american academy of Allergy, Asthma and Immunology (March 18-22, 2011 - San Francisco, California, USA).

    Science.gov (United States)

    Rabasseda, X

    2011-04-01

    San Francisco held this year's annual meeting of the American Academy of Allergy, Asthma and Immunology at the Moscone Center, where oral and poster sessions, educational courses and informal discussions called to the mind of attendees important news on a wide range of topics, including the main subject of this report: therapies for immune-based disorders as common as asthma or allergic rhinoconjunctivitis. A lot of important news from clinical and preclinical studies was disclosed to specialists attending this year's meeting. Most of the new research directly related to therapy for immunological diseases and disorders is summarized in the following report. 2011 Prous Science, S.A.U. or its licensors. All rights reserved.

  12. Supporting data for hydrologic studies in San Francisco Bay, California : meteorological measurements at the Port of Redwood City during 1998-2001

    Science.gov (United States)

    Schemel, Laurence E.

    2002-01-01

    Meteorological data were collected during 1998-2001 at the Port of Redwood City, California, to support hydrologic studies in South San Francisco Bay. The measured meteorological variables were air temperature, atmospheric pressure, quantum flux (insolation), and four parameters of wind speed and direction: scalar mean horizontal wind speed, (vector) resultant horizontal wind speed, resultant wind direction, and standard deviation of the wind direction. Hourly mean values based on measurements at five-minute intervals were logged at the site. Daily mean values were computed for temperature, infolation, pressure, and scalar wind speed. Daily mean values for 1998-2001 are described in this report, and a short record of hourly mean values is compared to data from another near-by station. Data (hourly and daily mean) from the entire period of record (starting in April 1992) and reports describing data prior to 1998 are provided.

  13. Results of bulk sediment analysis and bioassay testing on selected sediments from Oakland Inner Harbor and Alcatraz disposal site, San Francisco, California

    International Nuclear Information System (INIS)

    Word, J.Q.; Ward, J.A.; Woodruff, D.L.

    1990-09-01

    The Battelle/Marine Sciences Laboratory (MSL) was contracted by the US Army Corps of Engineers, San Francisco District, to perform bulk sediment analysis and oyster larvae bioassays (elutriate) on sediments from Inner Oakland Harbor, California. Analysis of sediment characteristics by MSL indicated elevated priority pollutants, PAHs, pesticides, metals, organotins, and oil and grease concentrations, when compared to Alcatraz Island Dredged Material Disposal Site sediment concentrations. Larvae of the Pacific oyster, Crassostrea gigas, were exposed to seawater collected from the Alcatraz Island Site water, and a series of controls using water and sediments collected from Sequim Bay, Washington. Exposure of larvae to the Alcatraz seawater and the 50% and 100% elutriate concentrations from each Oakland sediment resulted in low survival and a high proportion of abnormal larvae compared to Sequim Bay control exposures. MSL identified that field sample collection, preservation, and storage protocols used by Port of Oakland contractors were inconsistent with standard accepted practices. 23 refs., 10 figs., 40 tabs

  14. Groundwater-quality data in the North San Francisco Bay Shallow Aquifer study unit, 2012: results from the California GAMA Program

    Science.gov (United States)

    Bennett, George L.; Fram, Miranda S.

    2014-01-01

    Groundwater quality in the 1,850-square-mile North San Francisco Bay Shallow Aquifer (NSF-SA) study unit was investigated by the U.S. Geological Survey (USGS) from April to August 2012, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program’s Priority Basin Project (PBP). The GAMA-PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001 and is being conducted in collaboration with the SWRCB and Lawrence Livermore National Laboratory (LLNL). The NSF-SA study unit was the first study unit to be sampled as part of the second phase of the GAMA-PBP, which focuses on the shallow aquifer system.

  15. La Misión Indígena San Francisco Solano de Tacaaglé en las tierras fiscales de Formosa (1900-1950)

    OpenAIRE

    Dalla Corte, Gabriela

    2013-01-01

    La Misión Indígena fue inaugurada en el año 1901, en la zona del río Pilcomayo del Territorio Nacional de Formosa, precisamente al costado de la concesión paraguaya otorgada a Elisa (Elizabeth Alicia) Lynch. Desde entonces, fue trasladada, primero a Tacaaglé en 1902, donde adquirió el nombre de Misión San Francisco Solano, y posteriormente, en 1915, al riacho El Porteño. Los Misioneros Franciscanos asumieron la tarea de formar a “colonos indígenas” tobas y pilagás para la producción de azúcar...

  16. Diversidade genética de Enterolobium contortisiliquum (Vell. Morong. no Baixo Rio São Francisco, por meio de marcadores RAPD Genetic diversity of Enterolobium contortisiliquum (Vell. Morong. in the low San Francisco river by RAPD markers

    Directory of Open Access Journals (Sweden)

    Georgea da Cruz Santana

    2008-06-01

    Full Text Available Enterolobium contortisiliquum Vell. Morong (Leguminosae-Mimosoideae é uma espécie muito utilizada em programas de recuperação de matas ciliares no Baixo Rio São Francisco, devido ao seu rápido crescimento inicial. Assim, o objetivo deste trabalho foi avaliar, por meio de marcadores moleculares RAPD, a diversidade genética de oito indivíduos de uma população remanescente dessa espécie, visando contribuir para a definição de estratégias de coleta de sementes. Os indivíduos estão situados em uma área de 100 ha de mata ciliar do Baixo Rio São Francisco. Para a extração do DNA, pelo método CTAB 2%, foram utilizadas folhas tenras dos indivíduos. Testaram-se 20 oligonucleotídios de 10 bases de seqüência arbitrária, cujos produtos foram separados em gel de agarose 0,8%, submetidos à eletroforese horizontal, corados com brometo-de-etídio e visualizados em luz ultravioleta. A similaridade genética entre os indivíduos foi calculada pelo Coeficiente de Similaridade de Jaccard e a construção do dendrograma, realizada utilizando-se o método UPGMA. O valor médio de diversidade genética entre as matrizes foi de 49%, variando de 33 a 85%. Os indivíduos 6 e 7 apresentaram relativa proximidade genética (67%, não sendo indicado o plantio de suas mudas ou semeadura direta para recuperação de área ciliar em locais muito próximos. A partir dos resultados observados, podem-se desenvolver estratégias para a coleta de sementes e produção de mudas, auxiliando, assim, programas de restauração ambiental.Enterolobium contortisiliquum Vell. Morong (Leguminosae-Mimosoideae is very much used in riparian forest restoration programs in the Low San Francisco River because of its fast initial growth. The objective of this work was to evaluate by RAPD molecular markers the genetic diversity of eight individuals of a remaining population of this species, in order to contribute for the definition of strategies for seed production. The

  17. Application of an unstructured 3D finite volume numerical model to flows and salinity dynamics in the San Francisco Bay-Delta

    Science.gov (United States)

    Martyr-Koller, R.C.; Kernkamp, H.W.J.; Van Dam, Anne A.; Mick van der Wegen,; Lucas, Lisa; Knowles, N.; Jaffe, B.; Fregoso, T.A.

    2017-01-01

    A linked modeling approach has been undertaken to understand the impacts of climate and infrastructure on aquatic ecology and water quality in the San Francisco Bay-Delta region. The Delft3D Flexible Mesh modeling suite is used in this effort for its 3D hydrodynamics, salinity, temperature and sediment dynamics, phytoplankton and water-quality coupling infrastructure, and linkage to a habitat suitability model. The hydrodynamic model component of the suite is D-Flow FM, a new 3D unstructured finite-volume model based on the Delft3D model. In this paper, D-Flow FM is applied to the San Francisco Bay-Delta to investigate tidal, seasonal and annual dynamics of water levels, river flows and salinity under historical environmental and infrastructural conditions. The model is driven by historical winds, tides, ocean salinity, and river flows, and includes federal, state, and local freshwater withdrawals, and regional gate and barrier operations. The model is calibrated over a 9-month period, and subsequently validated for water levels, flows, and 3D salinity dynamics over a 2 year period.Model performance was quantified using several model assessment metrics and visualized through target diagrams. These metrics indicate that the model accurately estimated water levels, flows, and salinity over wide-ranging tidal and fluvial conditions, and the model can be used to investigate detailed circulation and salinity patterns throughout the Bay-Delta. The hydrodynamics produced through this effort will be used to drive affiliated sediment, phytoplankton, and contaminant hindcast efforts and habitat suitability assessments for fish and bivalves. The modeling framework applied here will serve as a baseline to ultimately shed light on potential ecosystem change over the current century.

  18. Continuous water-quality and suspended-sediment transport monitoring in the San Francisco Bay, California, water years 2011–13

    Science.gov (United States)

    Buchanan, Paul A.; Downing-Kunz, Maureen; Schoellhamer, David H.; Shellenbarger, Gregory; Weidich, Kurt

    2014-01-01

    The U.S. Geological Survey (USGS) monitors water quality and suspended-sediment transport in the San Francisco Bay. The San Francisco Bay area is home to millions of people, and the bay teems with both resident and migratory wildlife, plants, and fish. Fresh water mixes with salt water in the bay, which is subject both to riverine and marine (tides, waves, influx of salt water) influences. To understand this environment, the USGS, along with its partners, has been monitoring the bay’s waters continuously since 1988. Several water-quality variables are of particular importance to State and Federal resource managers and are monitored at key locations throughout the bay. Salinity, which indicates the relative mixing of fresh and ocean waters in the bay, is derived from specific conductance measurements. Water temperature, along with salinity, affects the density of water, which causes gravity driven circulation patterns and stratification in the water column. Turbidity is measured using light-scattering from suspended solids in water, and is used as a surrogate for suspended-sediment concentration (SSC). Suspended sediment often carries adsorbed contaminants; attenuates sunlight in the water column; deposits on tidal marsh and intertidal mudflats, which can help sustain these habitats as sea level rises; and deposits in ports and shipping channels, which can necessitate dredging. Dissolved oxygen, which is essential to a healthy ecosystem, is a fundamental indicator of water quality, and its concentration is affected by water temperature, salinity, ecosystem metabolism, tidal currents, and wind. Tidal currents in the bay reverse four times a day, and wind direction and intensity typically change on a daily cycle: consequently, salinity, water temperature, suspendedsediment concentration, and dissolvedoxygen concentration vary spatially and temporally throughout the bay, and continuous measurements are needed to observe these changes. The purpose of this fact sheet

  19. Simplifying consent for HIV testing is associated with an increase in HIV testing and case detection in highest risk groups, San Francisco January 2003-June 2007.

    Directory of Open Access Journals (Sweden)

    Nicola M Zetola

    2008-07-01

    Full Text Available Populations at highest risk for HIV infection face multiple barriers to HIV testing. To facilitate HIV testing procedures, the San Francisco General Hospital Medical Center eliminated required written patient consent for HIV testing in its medical settings in May 2006. To describe the change in HIV testing rates in different hospital settings and populations after the change in HIV testing policy in the SFDH medical center, we performed an observational study using interrupted time series analysis.Data from all patients aged 18 years and older seen from January 2003 through June 2007 at the San Francisco Department of Public Health (SFDPH medical care system were included in the analysis. The monthly HIV testing rate per 1000 had patient-visits was calculated for the overall population and stratified by hospital setting, age, sex, race/ethnicity, homelessness status, insurance status and primary language.By June 2007, the average monthly rate of HIV tests per 1000 patient-visits increased 4.38 (CI, 2.17-6.60, p<0.001 over the number predicted if the policy change had not occurred (representing a 44% increase. The monthly average number of new positive HIV tests increased from 8.9 (CI, 6.3-11.5 to 14.9 (CI, 10.6-19.2, p<0.001, representing a 67% increase. Although increases in HIV testing were seen in all populations, populations at highest risk for HIV infection, particularly men, the homeless, and the uninsured experienced the highest increases in monthly HIV testing rates after the policy change.The elimination of the requirement for written consent in May 2006 was associated with a significant and sustained increase in HIV testing rates and HIV case detection in the SFDPH medical center. Populations facing the higher barriers to HIV testing had the highest increases in HIV testing rates and case detection in response to the policy change.

  20. Acculturation, Dietary Practices and Risk for Childhood Obesity in an Ethnically Heterogeneous Population of Latino School Children in the San Francisco Bay Area

    Science.gov (United States)

    Schwartz, Norah; Jiménez-Cruz, Arturo; Bacardi-Gascon, Montserrat; Heyman, Melvin B.

    2015-01-01

    Previous studies have found increased acculturation to the US lifestyle increases risk for obesity in Latinos. However, methodologies differ, and results in children are inconsistent. Moreover, previous studies have not evaluated risk factors within the heterogeneous US population. We recruited 144 self-identified Latino school children and their mother or father in grades 4–6 in San Francisco parochial schools and South San Francisco public schools using an information letter distributed to all students. Children and parents had weights, heights, demographic information, dietary patterns and lifestyle variables collected in English or Spanish through an interview format. A high percentage of our children were overweight [≥85th percentile body mass index (BMI)] (62.5%) and obese (≥95th percentile BMI) (45.2%). Correspondingly parents also had a high percentage of overweight (BMI ≥ 25 & obesity (BMI ≥ 30) (45.3%). Mexico was the country of origin for 62.2% of parents, and 26.6% were from Central or South America. In multivariate logistic analysis, speaking Spanish at home was an independent risk factor for obesity [odds ratio (OR) 2.97, 95% confidence interval (CI) 1.28–6.86]. Eating breakfast daily (OR 0.34, 95% CI 0.15–0.78) and consumption of tortas (a Mexican fast food sandwich) (OR 0.45, 95% CI 0.21–1.00) were associated with decreased risk. In stratified analysis, significant differences in risk factors existed between Mexican origin versus Central/South American Latino children. The processes of acculturation likely impact eating and lifestyle practices differentially among Latino groups. Interventions should focus on ensuring that all children eat a nutritious breakfast and take into consideration ethnicity when working with Latino populations. PMID:22101726

  1. Application of an unstructured 3D finite volume numerical model to flows and salinity dynamics in the San Francisco Bay-Delta

    Science.gov (United States)

    Martyr-Koller, R. C.; Kernkamp, H. W. J.; van Dam, A.; van der Wegen, M.; Lucas, L. V.; Knowles, N.; Jaffe, B.; Fregoso, T. A.

    2017-06-01

    A linked modeling approach has been undertaken to understand the impacts of climate and infrastructure on aquatic ecology and water quality in the San Francisco Bay-Delta region. The Delft3D Flexible Mesh modeling suite is used in this effort for its 3D hydrodynamics, salinity, temperature and sediment dynamics, phytoplankton and water-quality coupling infrastructure, and linkage to a habitat suitability model. The hydrodynamic model component of the suite is D-Flow FM, a new 3D unstructured finite-volume model based on the Delft3D model. In this paper, D-Flow FM is applied to the San Francisco Bay-Delta to investigate tidal, seasonal and annual dynamics of water levels, river flows and salinity under historical environmental and infrastructural conditions. The model is driven by historical winds, tides, ocean salinity, and river flows, and includes federal, state, and local freshwater withdrawals, and regional gate and barrier operations. The model is calibrated over a 9-month period, and subsequently validated for water levels, flows, and 3D salinity dynamics over a 2 year period. Model performance was quantified using several model assessment metrics and visualized through target diagrams. These metrics indicate that the model accurately estimated water levels, flows, and salinity over wide-ranging tidal and fluvial conditions, and the model can be used to investigate detailed circulation and salinity patterns throughout the Bay-Delta. The hydrodynamics produced through this effort will be used to drive affiliated sediment, phytoplankton, and contaminant hindcast efforts and habitat suitability assessments for fish and bivalves. The modeling framework applied here will serve as a baseline to ultimately shed light on potential ecosystem change over the current century.

  2. Waves and tides responsible for the intermittent closure of the entrance of a small, sheltered tidal wetland at San Francisco, CA

    Science.gov (United States)

    Hanes, D.M.; Ward, K.; Erikson, L.H.

    2011-01-01

    Crissy Field Marsh (CFM; http://www.nps.gov/prsf/planyourvisit/crissy-field-marsh-and-beach.htm) is a small, restored tidal wetland located in the entrance to San Francisco Bay just east of the Golden Gate. The marsh is small but otherwise fairly typical of many such restored wetlands worldwide. The marsh is hydraulically connected to the bay and the adjacent Pacific Ocean by a narrow sandy channel. The channel often migrates and sometimes closes completely, which effectively blocks the tidal connection to the ocean and disrupts the hydraulics and ecology of the marsh. Field measurements of waves and tides have been examined in order to evaluate the conditions responsible for the intermittent closure of the marsh entrance. The most important factor found to bring about the entrance channel closure is the occurrence of large ocean waves. However, there were also a few closure events during times with relatively small offshore waves. Examination of the deep-water directional wave spectra during these times indicates the presence of a small secondary peak corresponding to long period swell from the southern hemisphere, indicating that CFM and San Francisco Bay in general may be more susceptible to long period ocean swell emanating from the south or southwest than the more common ocean waves coming from the northwest. The tidal records during closure events show no strong relationship between closures and tides, other than that closures tend to occur during multi-day periods with successively increasing high tides. It can be inferred from these findings that the most important process to the intermittent closure of the entrance to CFM is littoral sediment transport driven by the influence of ocean swell waves breaking along the CFM shoreline at oblique angles. During periods of large, oblique waves the littoral transport of sand likely overwhelms the scour potential of the tidal flow in the entrance channel. ?? 2011.

  3. Is drinking water a risk factor for endemic cryptosporidiosis? A case-control study in the immunocompetent general population of the San Francisco Bay Area

    Directory of Open Access Journals (Sweden)

    Nadle Joelle

    2003-03-01

    Full Text Available Abstract Background Cryptosporidiosis, caused by Cryptosporidium, is an enteric illness that has received much attention as an infection of immunocompromised persons as well as in community outbreaks (frequently waterborne. There are, however, no studies of the risk factors for sporadic community-acquired cryptosporidiosis in the immunocompetent US population. We undertook a case-control study in the San Francisco Bay Area as part of a national study sponsored by the Centers for Disease Control and Prevention to ascertain the major routes of transmission for endemic cryptosporidiosis, with an emphasis on evaluating risk from drinking water. Methods Cases were recruited from a population-based, active surveillance system and age-matched controls were recruited using sequential random-digit dialing. Cases (n = 26 and controls (n = 62 were interviewed by telephone using a standardized questionnaire that included information about the following exposures: drinking water, recreational water, food items, travel, animal contact, and person-to-person fecal contact, and (for adults sexual practices. Results In multivariate conditional logistic regression analyses no significant association with drinking water was detected. The major risk factor for cryptosporidiosis in the San Francisco Bay Area was travel to another country (matched odds ratio [95% confidence interval]: 24.1 [2.6, 220]. Conclusion The results of this study do not support the hypothesis that drinking water is an independent risk factor for cryptosporidiosis among the immunocompetent population. These findings should be used to design larger studies of endemic cryptosporidiosis to elucidate the precise mechanisms of transmission, whether waterborne or other.

  4. Gay and bisexual men engage in fewer risky sexual behaviors while traveling internationally: a cross-sectional study in San Francisco.

    Science.gov (United States)

    Truong, Hong-Ha M; Fatch, Robin; Grasso, Michael; Robertson, Tyler; Tao, Luke; Chen, Yea-Hung; Curotto, Alberto; McFarland, Willi; Grant, Robert M; Reznick, Olga; Raymond, H Fisher; Steward, Wayne T

    2015-05-01

    International travel poses potential challenges to HIV prevention. A number of studies have observed an association between travel and behavioural disinhibition. In the present study, we assessed differences in sexual behaviour while travelling internationally and within the USA, compared with being in the home environment. A probability-based sample of men who have sex with men (MSM) from the San Francisco Bay Area who had travelled internationally in the previous 12 months was recruited through an adapted respondent-driven sampling methodology (N=501). Participants completed interviewer-administered, computer-assisted surveys. Detailed partner-by-partner behavioural data by destination type were collected on 2925 sexual partnerships: 1028 while travelling internationally, 665 while travelling within the USA and 1232 while staying in the San Francisco Bay Area. The proportion of partnerships during international travel that involved unprotected anal intercourse (UAI) was lower compared with during domestic travel and staying locally. International travel was associated with decreased odds of receptive UAI (AOR=0.65, p=0.02) compared with staying locally and there was a trend towards decreased odds of insertive UAI (AOR=0.70, p=0.07). MSM engaged in proportionately fewer sexual activities which present a high HIV transmission risk when travelling internationally, namely unprotected receptive and insertive anal intercourse and particularly with HIV serodiscordant partners. The lower sexual risk-taking during international travel was robust to controlling for many factors, including self-reported HIV serostatus, age, relationship status and type of partnership. These findings suggest that when travelling internationally, MSM may experience behavioural disinhibition to a lesser extent than had been described previously. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  5. Effects of local geological conditions in the San Francisco Bay region on ground motions and the intensities of the 1906 earthquake

    International Nuclear Information System (INIS)

    Borcherdt, R.D.; Gibbs, J.F.

    1976-01-01

    Measurements of ground motion generated by nuclear explosions in Nevada have been completed for 99 locations in the San Francisco Bay region, California. The recordings show marked amplitude variations in the frequency band 0.25 to 3.0 Hz that are consistently related to the local geological conditions of the recording site. The average spectral amplifications observed for vertical and horizontal ground motions are, respectively: (1,1) for granite, (1.5, 1.6) for the Franciscan Formation, (3.0, 2.7) for the Santa Clara Formation, (3.3, 4.4) for alluvium, and (3.7, 11.3) for bay mud. Spectral amplification curves define predominant ground frequencies in the band 0.25 to 3.0 H for bay mud sites and for some alluvial sites. Amplitude spectra computed from recordings of seismic background noise at 50 sites do not generally define predominant ground frequencies. The intensities ascribed to various sites in the San Francisco Bay region for the California earthquake of April 18, 1906, are strongly dependent on distance from the zone of surface faulting and the geological character of the ground. Considering only those sites (approximately one square city block in size) for which there is good evidence for the degree of ascribed intensity, the intensities for 917 sites on Franciscan rocks generally decrease with the logarithm of distance as Intensity = 2.69 -- 1.90 log (Distance in kilometers). For sites on other geological units, intensity increments, derived from this empirical relation, correlate strongly with the Average Horizontal Spectral Amplifications (AHSA) according to the empirical relation Intensity Increment = 0.27 + 2.70 log (AHSA). Average intensity increments predicted for the various geological units are --0.3 for granite, 0.2 for the Franciscan Formation, 0.6 for the Great Valley sequence, 0.8 for the Santa Clara Formation, 1.3 for alluvium, and 2.4 for bay mud

  6. Effects of local geological conditions in the San Francisco Bay region on ground motions and the intensities of the 1906 earthquake

    Energy Technology Data Exchange (ETDEWEB)

    Borcherdt, R.D.; Gibbs, J.F.

    1976-04-01

    Measurements of ground motion generated by nuclear explosions in Nevada have been completed for 99 locations in the San Francisco Bay region, California. The recordings show marked amplitude variations in the frequency band 0.25 to 3.0 Hz that are consistently related to the local geological conditions of the recording site. The average spectral amplifications observed for vertical and horizontal ground motions are, respectively: (1,1) for granite, (1.5, 1.6) for the Franciscan Formation, (3.0, 2.7) for the Santa Clara Formation, (3.3, 4.4) for alluvium, and (3.7, 11.3) for bay mud. Spectral amplification curves define predominant ground frequencies in the band 0.25 to 3.0 H for bay mud sites and for some alluvial sites. Amplitude spectra computed from recordings of seismic background noise at 50 sites do not generally define predominant ground frequencies. The intensities ascribed to various sites in the San Francisco Bay region for the California earthquake of April 18, 1906, are strongly dependent on distance from the zone of surface faulting and the geological character of the ground. Considering only those sites (approximately one square city block in size) for which there is good evidence for the degree of ascribed intensity, the intensities for 917 sites on Franciscan rocks generally decrease with the logarithm of distance as Intensity = 2.69 -- 1.90 log (Distance in kilometers). For sites on other geological units, intensity increments, derived from this empirical relation, correlate strongly with the Average Horizontal Spectral Amplifications (AHSA) according to the empirical relation Intensity Increment = 0.27 + 2.70 log (AHSA). Average intensity increments predicted for the various geological units are --0.3 for granite, 0.2 for the Franciscan Formation, 0.6 for the Great Valley sequence, 0.8 for the Santa Clara Formation, 1.3 for alluvium, and 2.4 for bay mud.

  7. Competição de genótipos de goiabeira (Psidium guajava L. na região do submédio São Francisco Evaluation of guava genotypes in the submiddle of San Francisco Valley

    Directory of Open Access Journals (Sweden)

    Luiz Gonzaga Neto

    2003-12-01

    Full Text Available Com objetivo de avaliar e selecionar genótipos de goiabeira que possam incrementar o sistema de produção da cultura na região do Submédio São Francisco foi desenvolvido na Estação Experimental de Bebedouro, base física da Embrapa Semi-Árido, em Petrolina-PE, um experimento em blocos ao acaso com cinco tratamentos (Paluma, Red Fleshed, Surubim, Red Selection of Florida e Ruby Supreme e cinco repetições. Considerando os resultados obtidos relativos a primeira e segunda poda de frutificação e análise conjunta dos dois anos de produção, observou-se que a variedade Surubim apresentou tendência de maior produção e maior número de frutos, entre os genótipos estudados.The objective of this study was to discriminate and select guava genotypes to improve the crop production system in the Submiddle of San Francisco Valley. An experiment was carried out at the Bebedouro Experimental Sation that belongs to Embrapa Semiarid in Petrolina, State of Pernambuco, with five genotypes of guava: Paluma, Red Fleshed, Surubim, Red Selection of Florida and Ruby Supreme. A randomized block design was used as statistical model with five treataments, and five repetitions. The results, related to the first and the second fruit set prunings and two year of combined analyses for fruit yield, indicated that Surubim variety tended to higher yield and greater number of fruits among the five genotypes tested.

  8. Coupling alongshore variations in wave energy to beach morphologic change using the SWAN wave model at Ocean Beach, San Francisco, CA

    Science.gov (United States)

    Eshleman, Jodi L.; Barnard, Patrick L.; Erikson, Li H.; Hanes, Daniel M.

    2007-01-01

    Coastal managers have faced increasing pressure to manage their resources wisely over the last century as a result of heightened development and changing environmental forcing. It is crucial to understand seasonal changes in beach volume and shape in order to identify areas vulnerable to accelerated erosion. Shepard (1950) was among the first to quantify seasonal beach cycles. Sonu and Van Beek (1971) and Wright et al. (1985) described commonly occurring beach states. Most studies utilize widest spaced 2-D cross shore profiles or shorelines extracted from aerial photographs (e.g. Winant et al. 1975; Aubrey, 1979, Aubrey and Ross, 1985; Larson and Kraus, 1994; Jimenez et al., 1977; Lacey and Peck, 1998; Guillen et al., 1999; Norcorss et al., 2002) to analyzed systematic changes in beach evolution. But with the exception of established field stations, such as Duck, NC (Birkemeier and Mason, 1984), ans Hazaki Oceanographical Research Station (HORS) in Japan (Katoh, 1997), there are very few beach change data sets with high temporal and spatial resolutions (e.g. Dail et al., 2000; Ruggiero et al., 2005; Yates et al., in press). Comprehensive sets of nearshore morphological data and local in situ measurements outside of these field stations are very rare and virtually non-existent high-energy coasts. Studied that have attempted to relate wave statistics to beach morphology change require some knowledge of the nearshore wave climate, and have had limited success using offshore measurement (Sonu and Van Beek, 1971; Dail et al., 2000). The primary objective of this study is to qualitatively compare spatially variable nearshore wave predictions to beach change measurements in order to understand the processes responsible for a persistent erosion 'hotspot' at Ocean Beach, San Francisco, CA. Local wave measurements are used to calibrate and validate a wave model that provides nearshore wave prediction along the beach. The model is run for thousands of binned offshore wave

  9. Una Aparición de la Virgen con el Niño a san Felipe Neri de Francisco Ignacio Ruiz de la Iglesia: atribución y contexto iconográfico

    Directory of Open Access Journals (Sweden)

    Gutiérrez Pastor, Ismael

    2013-06-01

    Full Text Available The author studies a painting of the Apparition of the Virgin and Child with St. Philip Neri, attributing it to the painter Francisco Ignacio Ruiz de la Iglesia and analyzing its iconography in the context of Baroque painting in Madrid.Se estudia una pintura de la Aparición de la Virgen con el Niño a San Felipe Neri, se atribuye al pintor Francisco Ignacio Ruiz de la Iglesia y se analiza su iconografía en el contexto de la pintura madrileña del Barroco.

  10. Monitoring the Northern San Francisco Bay Water Quality with Landsat-8. Nicholas B. Tufillaroa , and Curtiss O. Davisa. aOregon State University, Corvallis, OR, 97331, USA, nbt@coas.oregonstate.edu

    Science.gov (United States)

    Davis, C. O.; Tufillaro, N.

    2016-02-01

    Landsat-8's high spatial resolution ( 30 nm nominal), improved signal-to-noise (12bit digitizer) and expanded band set open up new applications for coastal and in-land waters. We use a recent ocean color processor for Landsat-8 created by Vanhellemont and Ruddick (RSE, 2015)to examine changes in the Northern San Francisco Bay, in particular looking for possiblechanges due to the on-going California drought. For instance, a temporary drought barrier to prevent salt water intrusion was placed during May of 2015 at West False River in the Sacramento-San Joaquin Delta. Using the new Landsat-8 ocean color products, we illustrate how to monitor changes in macro algae and plants (Sago pondweed (native), Curly pondweed (non-native)) in regions directly effected,such as the Franks Track region. Product maps using panchromatic enhancement ( 15 m resolution) andscene based atmospheric correction allow a detailed synoptic look every 16 days during theSpring, Summer, and Fall of 2015. This work is part of a larger NASA funded project aimed atimproving the modeling and predictive capabilities of the biogeochemical state for the San Francisco Bay(Davis, PI: Impacts of Population Growth on the San Francisco Bay and Delta Ecosystem, 2014-2017).

  11. Agricultural Chemical Concentrations and Loads in Rivers Draining the Central Valley, California, to the San Francisco Bay-Delta Estuary: Before and During an Extended Drought

    Science.gov (United States)

    Domagalski, J. L.

    2016-12-01

    Drought or near drought conditions have occurred in California since 2012. Although some parts of the State received near normal precipitation in water year 2016, other locations were still below average. Extended drought can impact aquatic organisms in a variety of ways because of decreased flows and elevated water temperature. However, lower precipitation and availability of irrigation water may limit subsequent runoff, resulting in reduced concentrations and loads of certain environmental toxicants, such as pesticides and ammonia, thereby limiting their toxic effects. In this study, funded by the U.S. Geological Survey National Water Quality Program, the occurrence of 227 pesticides and degradation products, and nutrients was assessed before and during this current drought in the two largest rivers draining to the San Francisco Bay: the Sacramento and San Joaquin Rivers. The watersheds of both rivers include substantial agricultural and urban land use. Herbicides, insecticides, fungicides, and ammonia were detected throughout the study (2010 to 2016) and models of daily concentration using the seasonal wave model (rloadest) were formulated to assess the amount of time that concentrations may have exceeded benchmark levels known to be toxic to aquatic organisms. Frequently detected pesticides included the fungicide azoxystrobin, herbicides or their degradation products such as diuron, glyphosate, and metolachlor, and insecticides such as imidacloprid. Compounds that are transported primarily by surface runoff generally showed decreasing concentrations as the drought progressed, especially in the San Joaquin River. Compounds mainly transported by groundwater, as indicated by seasonal concentration profiles, had more stable concentrations in the rivers. Mass loads to the Bay all decreased, as expected, because of the lower river discharge. When compared to aquatic-life benchmarks, modeled concentrations indicated that individual compounds were not contributing to

  12. Structure of the 1906 near-surface rupture zone of the San Andreas Fault, San Francisco Peninsula segment, near Woodside, California

    Science.gov (United States)

    Rosa, C.M.; Catchings, R.D.; Rymer, M.J.; Grove, Karen; Goldman, M.R.

    2016-07-08

    High-resolution seismic-reflection and refraction images of the 1906 surface rupture zone of the San Andreas Fault near Woodside, California reveal evidence for one or more additional near-surface (within about 3 meters [m] depth) fault strands within about 25 m of the 1906 surface rupture. The 1906 surface rupture above the groundwater table (vadose zone) has been observed in paleoseismic trenches that coincide with our seismic profile and is seismically characterized by a discrete zone of low P-wave velocities (Vp), low S-wave velocities (Vs), high Vp/Vs ratios, and high Poisson’s ratios. A second near-surface fault strand, located about 17 m to the southwest of the 1906 surface rupture, is inferred by similar seismic anomalies. Between these two near-surface fault strands and below 5 m depth, we observed a near-vertical fault strand characterized by a zone of high Vp, low Vs, high Vp/Vs ratios, and high Poisson’s ratios on refraction tomography images and near-vertical diffractions on seismic-reflection images. This prominent subsurface zone of seismic anomalies is laterally offset from the 1906 surface rupture by about 8 m and likely represents the active main (long-term) strand of the San Andreas Fault at 5 to 10 m depth. Geometries of the near-surface and subsurface (about 5 to 10 m depth) fault zone suggest that the 1906 surface rupture dips southwestward to join the main strand of the San Andreas Fault at about 5 to 10 m below the surface. The 1906 surface rupture forms a prominent groundwater barrier in the upper 3 to 5 m, but our interpreted secondary near-surface fault strand to the southwest forms a weaker barrier, suggesting that there has been less or less-recent near-surface slip on that strand. At about 6 m depth, the main strand of the San Andreas Fault consists of water-saturated blue clay (collected from a hand-augered borehole), which is similar to deeply weathered serpentinite observed within the main strand of the San Andreas Fault at

  13. The epidemiology and surveillance response to pandemic influenza A (H1N1) among local health departments in the San Francisco Bay Area.

    Science.gov (United States)

    Enanoria, Wayne T A; Crawley, Adam W; Tseng, Winston; Furnish, Jasmine; Balido, Jeannie; Aragón, Tomás J

    2013-03-27

    Public health surveillance and epidemiologic investigations are critical public health functions for identifying threats to the health of a community. Very little is known about how these functions are conducted at the local level. The purpose of the Epidemiology Networks in Action (EpiNet) Study was to describe the epidemiology and surveillance response to the 2009 pandemic influenza A (H1N1) by city and county health departments in the San Francisco Bay Area in California. The study also documented lessons learned from the response in order to strengthen future public health preparedness and response planning efforts in the region. In order to characterize the epidemiology and surveillance response, we conducted key informant interviews with public health professionals from twelve local health departments in the San Francisco Bay Area. In order to contextualize aspects of organizational response and performance, we recruited two types of key informants: public health professionals who were involved with the epidemiology and surveillance response for each jurisdiction, as well as the health officer or his/her designee responsible for H1N1 response activities. Information about the organization, data sources for situation awareness, decision-making, and issues related to surge capacity, continuity of operations, and sustainability were collected during the key informant interviews. Content and interpretive analyses were conducted using ATLAS.ti software. The study found that disease investigations were important in the first months of the pandemic, often requiring additional staff support and sometimes forcing other public health activities to be put on hold. We also found that while the Incident Command System (ICS) was used by all participating agencies to manage the response, the manner in which it was implemented and utilized varied. Each local health department (LHD) in the study collected epidemiologic data from a variety of sources, but only case reports

  14. Gestión de Tecnología en Empresas de Clase Mundial del Sector Bebidas en Venezuela Caso: Municipio San Francisco – Estado Zulia

    Directory of Open Access Journals (Sweden)

    Francisco Batlle Rois Méndez

    2014-01-01

    Full Text Available La investigación se planteó como objetivo analizar la gestión de tecnología en empresas de clase mundial delsector bebidas del municipio San Francisco del estado Zulia, Venezuela. Para alcanzar el objetivo propuesto se revisaron los postulados del Modelo Nacional de Tecnología (MNT (2009 y los aportes teóricos de autores como Gaynor (1999, Peters (2006 y Bosch (2000, en relación con la gestión de tecnología. El estudio fue de tipo descriptivo bajo un diseño de campo, no experimental-transeccional y con una muestra constituida por seis sujetos encargados de gerenciar tecnología en las unidades productivas de la Cervecería Polar y Pepsi de Venezuela. Los resultados obtenidos, mediante el cuestionario utilizado para la recolección de información, permitieron concluir que la gestión de tecnología, en dichas empresas, se desarrolla de manera empírica con una configuración funcional en la cual no existen estándares establecidos en cuanto a su integración con la gestión del conocimiento ni en la necesidad de generar unidades de I+D que tengan foco en la gestión de la tecnología. Sin embargo, el reconocimiento del impacto de la gestión tecnológica en los resultados positivos de la empresa condujo a reconocer mejores prácticas y experiencia a través de las actividades de vigilancia, planeación, habilitación, protección e implantación tecnológica.Palabras Clave: Gestión; tecnología; conocimiento; competitividad. Management of Technology in the Business World Class Beverages Sector in Venezuela Case: San Francisco County - Zulia StateAbstractThe main purpose of this research was to analyze the technology management in world-class companies belonging to the drinking sector at the San Francisco county, Zulia State, Venezuela. The tenets of National Model for Technology (MNT (2009 and the theoretical contributions of authors such as Gaynor (1999, Peters (2006 and Bosch (2000, in relation to the management of technology were

  15. Use of dissolved inorganic carbon isotopes to track photosynthesis, respiration, and nitrification along a 56 mile transect in the Sacramento River and San Francisco Bay

    Science.gov (United States)

    Silva, S. R.; Kendall, C.; Peek, S.; Young, M. B.

    2013-12-01

    A decline in phytoplankton stocks in the San Francisco Bay and Delta is thought to contribute to the pelagic organism decline observed over the past two decades. One factor controlling phytoplankton growth rate is the availability of nutrients. Although there is an excess of nutrients in the Bay and Delta, the type and relative abundance of nutrients is critical to phytoplankton growth. To evaluate the response of phytoplankton to nutrient sources and to better understand phytoplankton dynamics downstream, we tested the hypothesis that the δ13C values of dissolved inorganic carbon (DIC) along with conventional water chemistry analyses will record events such as increased nitrification (related to the Sacramento River Wastewater Treatment Plant ammonium input) and algal blooms, and reflect the balance between photosynthesis and bacterial respiration. Multiple parameters affect [DIC] and its δ13C, including DIC sources, pH, and biological processes. Consumption of CO2 by phytoplankton during photosynthesis and by autotrophic bacteria during nitrification both result in increases in δ13C-DIC. However, photosynthesis and nitrification have very different relationships to chlorophyll and nutrient concentrations. The balance between heterotrophic bacterial respiration and photosynthesis should be reflected in trends in DIC, nutrient, and chlorophyll concentration, and δ13C-DIC. The δ13C of DIC should also be reflected in the δ13C of phytoplankton with approximately a 20 per mil fractionation. Significant deviation in the fractionation factor may indicate local variations in growth rate, nutrient availability, or speciation. Combined, these parameters should provide a gauge of the relative importance of the above mentioned processes. To test this hypothesis, we collected 19 water samples per cruise between July 2012 and July 2013 along a 56 mile transect between Rio Vista on the Sacramento River and San Francisco Bay near Angel Island during 8 cruises on the USGS RV

  16. Estrategias de información, sensibilización y desarrollo de capacidadespara la gestión del Turismo Rural. Caso San Francisco Oxtotilpan, Estado de México.

    OpenAIRE

    González Domínguez, Irais

    2015-01-01

    El pueblo Matlazinca es uno de los grupos indígenas del país que mayor desintegración ha sufrido desde la época de la Conquista hasta la actualidad, de haber sido un grupo que ocupaba un amplio territorio en la época prehispánica, el correspondiente a los actuales estados de Michoacán, Guerrero y México, se ha reducido a una sola comunidad: San Francisco Oxtotilpan, ubicada en el municipio de Temascaltepec, Estado de México. Actualmente, los pobladores de la comunidad matlazinca de San Fr...

  17. Continuous water-quality and suspended-sediment transport monitoring in the San Francisco Bay, California, water years 2014–15

    Science.gov (United States)

    Buchanan, Paul A.; Downing-Kunz, Maureen; Schoellhamer, David H.; Livsey, Daniel N.

    2018-03-08

    The U.S. Geological Survey (USGS) monitors water quality and suspended-sediment transport in the San Francisco Bay (bay) as part of a multi-agency effort to address management, water supply, and ecological concerns. The San Francisco Bay area is home to millions of people, and the bay teems both with resident and with migratory wildlife, plants, and fish. Freshwater mixes with salt water in the bay, which is subject both to riverine influences (floods, droughts, managed reservoir releases and freshwater diversions) and to marine influences (tides, waves, effects of salt water). To understand this environment, the USGS, along with its partners (see “Acknowledgements”), has been monitoring the bay’s waters continuously since 1988. Several water-quality variables are of particular importance to State and Federal resource managers and are monitored at key locations throughout the bay (fig. 1). Salinity, which indicates the relative mixing of fresh and ocean waters in the bay, is derived from specific conductance measurements. Water temperature, along with salinity, affects the density of water, which controls gravity-driven circulation patterns and stratification in the water column. Turbidity, a measure of light scattered from suspended particles in the water, is used to estimate suspended-sediment concentration (SSC). Suspended sediment affects the bay in multiple ways: attenuation of sunlight in the water column, affecting phytoplankton growth; deposition on tidal marsh and intertidal mudflats, which can help sustain these habitats as sea level rises; deposition in ports and shipping channels, which can necessitate dredging; and often, adsorption of contaminants, affecting their distribution and concentrations in the environment. Dissolved oxygen concentration, essential to a healthy ecosystem and a fundamental indicator of water quality, is affected by water temperature, salinity, ecosystem metabolism, tidal currents, and wind. Tidal currents in the bay

  18. Food insecurity, chronic illness, and gentrification in the San Francisco Bay Area: An example of structural violence in United States public policy.

    Science.gov (United States)

    Whittle, Henry J; Palar, Kartika; Hufstedler, Lee Lemus; Seligman, Hilary K; Frongillo, Edward A; Weiser, Sheri D

    2015-10-01

    Food insecurity continues to be a major challenge in the United States, affecting 49 million individuals. Quantitative studies show that food insecurity has serious negative health impacts among individuals suffering from chronic illnesses, including people living with HIV/AIDS (PLHIV). Formulating effective interventions and policies to combat these health effects requires an in-depth understanding of the lived experience and structural drivers of food insecurity. Few studies, however, have elucidated these phenomena among people living with chronic illnesses in resource-rich settings, including in the United States. Here we sought to explore the experiences and structural determinants of food insecurity among a group of low-income PLHIV in the San Francisco Bay Area. Thirty-four semi-structured in-depth interviews were conducted with low-income PLHIV receiving food assistance from a local non-profit in San Francisco and Alameda County, California, between April and June 2014. Interview transcripts were coded and analysed according to content analysis methods following an inductive-deductive approach. The lived experience of food insecurity among participants included periods of insufficient quantity of food and resultant hunger, as well as long-term struggles with quality of food that led to concerns about the poor health effects of a cheap diet. Participants also reported procuring food using personally and socially unacceptable strategies, including long-term dependence on friends, family, and charity; stealing food; exchanging sex for food; and selling controlled substances. Food insecurity often arose from the need to pay high rents exacerbated by gentrification while receiving limited disability income--​a situation resulting in large part from the convergence of long-standing urban policies amenable to gentrification and an outdated disability policy that constrains financial viability. The experiences of food insecurity described by participants in this

  19. Historical occurrence of coho salmon (Oncorhynchus kisutch) in streams of the Santa Cruz Mountain region of California: response to an Endangered Species Act petition to delist coho salmon south of San Francisco Bay

    Science.gov (United States)

    Brian C. Spence; Walter G. Duffy; John Carlos Garza; Bret Harvey; Susan M. Sogard; Laurie A. Weitkamp; Thomas H. Williams; David A. Boughton

    2011-01-01

    In November 2003, the National Marine Fisheries Service received a petition from Homer T. McCrary to redefine the southern extent of the Central California Coast Coho Salmon Evolutionarily Significant Unit (CCC Coho Salmon ESU) to exclude populations that spawn in coastal watersheds south of the entrance to San Francisco Bay (i.e., the Golden Gate). The petitioner’s...

  20. Evaluating Ambient Concentrations and Local Emissions of Greenhouse Gases (GHGs) in the San Francisco Bay Area of California Using a Comprehensive Fixed-site and Mobile Monitoring Network

    Science.gov (United States)

    Guha, A.; Bower, J. P.; Martien, P. T.; Randall, S.; Young, A.; Hilken, H.; Stevenson, E.

    2015-12-01

    The Bay Area Air Quality Management District (hence the Air District) is the greater San Francisco Bay metropolitan region's chief air quality regulatory agency. Aligning itself with Executive Order S-3-05, the Air District has set a goal to reduce the region's GHG emissions by 80% below 1990 levels by the year 2050. The Air District's 10-point Climate Action Work Program lays out the agency's priorities, actions and coordination with regional stakeholders. The Program has three core objectives: (1) to develop a technical and monitoring program to document the region's GHG sources and related emissions, (2) to implement a policy and rule-based approach to control and regulate GHG emissions, and finally, (3) to utilize local governance, incentives and partnerships to encourage GHG emissions reductions.As part of the technical program, the Air District has set up a long term, ambient GHG monitoring network at four sites. The first site is located north and upwind of the urban core at Bodega Bay by the Pacific Coast. It mostly receives clean marine inflow and serves as the regional background site. The other three sites are strategically located at regional exit points for Bay Area plumes that presumably contain GHG enhancements from local sources. These stations are at San Martin, located south of the San Jose metropolitan area; at Patterson Pass at the cross section with California's Central Valley; and at Bethel Island at the mouth of the Sacramento-San Joaquin Delta. At all sites, carbon dioxide (CO2) and methane (CH4) are being measured continuously, along with combustion tracer CO and other air pollutants. The GHG measurements are performed with high precision and fast laser instruments (Picarro Inc). In the longer term, the network will allow the Air District to monitor ambient concentrations of GHGs and thus evaluate the effectiveness of its policy, regulation and enforcement efforts. We present data from the sites in their first few months of operation and

  1. Provision of utility support services to the US Department of Energy San Francisco Operations Office. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    1994-04-01

    The main purpose of this project was to provide to DOE/SAN continuing, follow-up support to realize savings from a number of alternate supply arrangements that had already been and/or were expected to be identified under the original project. This expected continuation of these efforts is demonstrated by certain of the tasks that are spelled out in the Statement of Work. For example: Evaluate and propose alternative options and methods for improving efficiency, reducing cost, and making effective use of the energy supplies and facilities under various conditions of use; Provide engineering and economic analysis and recommendations for utility-related facilities and service issues, such as high voltage discounts, ownership of facilities, etc.; Assist in developing strategy and documentation in support of negotiating utility contracts and modifications thereto. In addition, the follow-on contract provided for monitoring and intervening in rate cases that had particular relevance to the DOE/SAN laboratories.

  2. Comparison between lead levels in dandelions grown in an ultra-clean lab environment (baseline) and those collected from the San Francisco Bay Area

    Science.gov (United States)

    Rojero, J.; Odigie, K. O.; Hibdon, S.; Flegal, A. R.

    2011-12-01

    This study is aimed at establishing the baseline (natural) levels of lead in dandelions (Taraxacum officinale) grown in an ultra-clean environment. Dandelions have been used extensively as biomonitors of environmental lead levels since their distribution is global and they can be easily collected. However, industrial lead contamination is so pervasive that even dandelions from the most remote areas in the world may be contaminated with industrial lead. Therefore, this work will test the hypothesis that "natural" lead levels in dandelions are lower than any previously published values - by growing them in a HEPA filtered air (Class 100) trace metal clean room with high purity (18 MΩ cm) water. Concentrations and isotopic compositions of lead in the clean-room grown dandelions will be compared to values in literature and to those of lead in dandelions collected from San Francisco Bay Area. Lead is a dense, ductile, and highly malleable metal that is found naturally in our environment. Due to its properties it is currently highly used in building construction, in ceramic glazes, lead chromate and in PVC plastic used to coat electrical cords. The uses of lead have included paint, leather tanning, and being used as an additive to gasoline prior to the mid 1970's, as well as others. Due to its many uses, humans are susceptible to lead regularly through various means of exposure from air, water and soil, often leading to lead toxicity.

  3. Using community-based participatory research to design and initiate a study on immigrant worker health and safety in San Francisco's Chinatown restaurants.

    Science.gov (United States)

    Minkler, Meredith; Lee, Pam Tau; Tom, Alex; Chang, Charlotte; Morales, Alvaro; Liu, Shaw San; Salvatore, Alicia; Baker, Robin; Chen, Feiyi; Bhatia, Rajiv; Krause, Niklas

    2010-04-01

    Restaurant workers have among the highest rates of work-related illness and injury in the US, but little is known about the working conditions and occupational health status of Chinese immigrant restaurant workers. Community-based participatory research (CBPR) was employed to study restaurant working conditions and worker health in San Francisco's Chinatown. A community/academic/health department collaborative was formed and 23 restaurant workers trained on research techniques and worker health and safety. A worker survey instrument and a restaurant observational checklist were collaboratively developed. The checklist was piloted in 71 Chinatown restaurants, and the questionnaire administered to 433 restaurant workers. Restaurant workers, together with other partners, made substantial contributions to construction of the survey and checklist tools and improved their cultural appropriateness. The utility of the checklist tool for restaurant-level data collection was demonstrated. CBPR holds promise for both studying worker health and safety among immigrant Chinese restaurant workers and developing culturally appropriate research tools. A new observational checklist also has potential for restaurant-level data collection on worker health and safety conditions. (c) 2010 Wiley-Liss, Inc.

  4. Comunidades de briófitos reofílicos en un caño de montaña, en San Francisco, Cundinamarca, Colombia

    Directory of Open Access Journals (Sweden)

    Linares Castillo Edgar Leonardo

    1997-06-01

    Full Text Available The rheophilic bryophyte vegetation of a montan e stream between 2450-2650 m alt, near San Francisco, in the northwest of Cundinamarca, on the western slope of the Colombian Cordillera Oriental, was studied following the Zürich-Montpellier approach. Recognized were: 1 community of Thamnobryum fasciculatum and Monoelea gottschei. under foresto and 2 community of Brachythecium plumosum and Platyhypnidium aquaticum. outside the forest. The structure, floristic composition and ecological aspects were considered.Se estudió la vegetación de briófitos reofílicos en un caño de montaña, en el gradiente altitudinal entre 2450 y 2650 m. Se hallaron dos comunidades: una comunidad de Thamnobryum fasciculatum y Monoelea gottschei propia del interior del bosque y otra comunidad de Brachythecium plumosum y Platyhypnidium aquaticum de los potreros. Se registró la estructura, composición florística, los rasgos ecológicos y la distribución de las comunidades.

  5. Relationships among cytochromes P450 and dioxin equivalents in pipping heron embryos from Virginia, the Great Lakes and San Francisco Bay

    Science.gov (United States)

    Rattner, B.A.; Hatfield, J.S.; Melancon, M.J.; Custer, T.W.; Tillett, D.E.

    1993-01-01

    Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from undisturbed (Chincoteague National Wildlife Refuge, VA) and industrialized (Cat Island, Green Bay, WI; San Francisco Bay, CA) locations. Hepatic P450 associated monooxygenases (AHH, EROD, BROD, ECOD) and P450 proteins (CYP1A, CYP2B) were induced up to 85-fold, and were associated with burdens of total PCBs and 11 AHH-active PCB congeners. Dioxin equivalents (TCDD-EQs) of sample extracts, derived by bioassay (H4I1E rat hepatoma cell) and mathematically (product of PCB congener concentration and relative TCDD potency), revealed greatest TCDD-EQs in Cat Island samples. TCDD-EQs were associated with P450s, especially BROD, EROD and CYP1A (r2 = 0.35 to 0.66). TCDD-EQs derived by bioassay were highly correlated with TCDD-EQs derived mathematically (r2 = 0.58 to 0.67) . Multiple regressions were also performed to investigate relationships among P450s and PCB congeners. In summary, these data demonstrate that hepatic P450s of heron embryos are biomarkers of exposure to dioxin-like compounds and provide further evidence that this species has considerable value for assessing wetland and estuarine contamination.

  6. Relationship Power Among Same-Sex Male Couples in New York and San Francisco: Laying the Groundwork for Sexual Risk Reduction Interventions Focused on Interpersonal Power.

    Science.gov (United States)

    Dworkin, Shari L; Zakaras, Jennifer M; Campbell, Chadwick; Wilson, Patrick; Grisham, Kirk; Chakravarty, Deepalika; Neilands, Torsten B; Hoff, Colleen

    2017-09-01

    Research is clear that power differentials between women and men shape women's human immunodeficiency virus (HIV) risks; however, little research has attempted to examine power differentials within same-sex male (SSM) couples and whether these influence sexual risk outcomes. To produce the first quantitative scale that measures power in SSM relationships, the current work was a Phase 1 qualitative study that sought to understand domains of relationship power and how power operated in the relationship among 48 Black, White, and interracial (Black-White) SSM couples recruited from San Francisco and New York. Interview domains were focused on definitions of power and perceptions of how power operated in the relationship. Findings revealed that couples described power in three key ways: as power exerted over a partner through decision-making dominance and relationship control; as power to accomplish goals through personal agency; and as couple-level power. In addition, men described ways that decision-making dominance and relationship control could be enacted in the relationship-through structural resources, emotional and sexual influence, and gender norm expectations. We discuss the implications of these findings for sexual risks and HIV care and treatment with SSM couples that are focused on closing gaps in power.

  7. La participación de la comunidad de San Francisco de Asis, Colombia en la actividad turística

    Directory of Open Access Journals (Sweden)

    Claudia Stella Vera

    2005-11-01

    Full Text Available San Francisco de Asís es una población ubicada en el Darién, Caribe colombiano, que ha vivido desde hace algunos años un desarrollo turístico. Su oferta natural ha propiciado paulatinamente el desarrollo Se describe entonces dicho proceso de participación así como los logros obtenidos durante y como resultado de los talleres organizados con la población local y dirigidos por la autora. Unos de estos, fue sentar bases para una organización que diera continuidad al proceso participativo. Otra experiencia interesante fue la formación de un grupo de niños que asumieron el papel de ecoguias. El trabajo menciona en el margen, la incidencia de los otros actores, tales como asociaciones comunitarias, onG, prestadores de servicios turísticos y entes gubernamentales, en la actividad turística. La ponencia plantea la experiencia vivida durante una investigación realizada para optar por el título de administradora de empresas turísticas.

  8. Acceptability of Global Positioning System technology to survey injecting drug users' movements and social interactions: a pilot study from San Francisco, USA.

    Science.gov (United States)

    Mirzazadeh, A; Grasso, M; Johnson, K; Briceno, A; Navadeh, S; McFarland, W; Page, K

    2014-01-01

    Despite potential applications for improving health services using GPS technology, little is known about ethical concerns, acceptability, and logistical barriers for their use, particularly among marginalized groups. We garnered the insights of people who inject drug (PWID) in San Francisco on these topics. PWID were enrolled through street-outreach (n=20) and an ongoing study (n=4) for 4 focus group discussions. Participants also completed a self-administered questionnaire on demographic characteristics and their numbers and types of interactions with other PWID. Median age was 30.5 years, majorities were male (83.3%) and white (68.2%). Most interacted with other PWID for eating meals and purchasing drugs over the last week; fewer reported interactions such as sexual contact, drug treatment, or work. Participants identified several concerns about carrying GPS devices, including what authorities might do with the data, that other PWID and dealers may suspect them as informants, and adherence to carrying and use. Most felt concerns were surmountable with detailed informed consent on the purpose of the study and practical ways to carry, charge, and hide devices. PWID felt data collection on their movements and social interactions with other PWID using GPS can be acceptable with addressing specific concerns. The technology is now in hand to greatly expand the ability to monitor health conditions with respect to the environment and improve the location of prevention, care, and treatment facilities to serve hard to reach, mobile, and hidden populations.

  9. Landslides, Floods, and Marine Effects of the Storm of January 3-5, 1982, in the San Francisco Bay Region, California

    Science.gov (United States)

    Ellen, Stephen D.; Wieczorek, Gerald F.

    1988-01-01

    A catastrophic rainstorm in central California on January 3-5,1982, dropped as much as half the mean annual precipitation within a period of about 32 hours, triggering landslides and floods throughout 10 counties in the vicinity of the San Francisco Bay. More than 18,000 of the slides induced by the storm transformed into debris flows that swept down hillslopes or drainages with little warning. Debris flows damaged at least 100 homes, killed 14 residents, and carried a 15th victim into a creek. Shortly after rainfall ceased, more than 459,000 m3 of earth and rock slid from a mountainside above the community of Love Creek in Santa Cruz County, burying 10 people in their homes. Throughout the bay region, thousands of people vacated homes in hazardous areas, entire communities were isolated as roads were blocked, public water systems were destroyed, and power and telephone services were disrupted. Altogether, the storm damaged 6,300 homes, 1,500 businesses, and tens of kilometers of roads, bridges, and communication lines. Preliminary rough estimates of total storm damage, compiled for emergency purposes within 2 weeks of the storm, exceeded $280 million. Carefully documented direct costs from landslides exceeded $66 million; total costs from landslides certainly were greater and probably constituted a much larger proportion of the total storm damage than suggested by these disparate figures. Landslides accounted for 25 of the 33 deaths attributed to the storm.

  10. Sedimentary organic biomarkers suggest detrimental effects of PAHs on estuarine microbial biomass during the 20th century in San Francisco Bay, CA, USA

    Science.gov (United States)

    Nilsen, Elena B.; Rosenbauer, Robert J.; Fuller, Christopher C.; Jaffe, Bruce E.

    2014-01-01

    Hydrocarbon contaminants are ubiquitous in urban aquatic ecosystems, and the ability of some microbial strains to degrade certain polycyclic aromatic hydrocarbons (PAHs) is well established. However, detrimental effects of petroleum hydrocarbon contamination on nondegrader microbial populations and photosynthetic organisms have not often been considered. In the current study, fatty acid methyl ester (FAME) biomarkers in the sediment record were used to assess historical impacts of petroleum contamination on microbial and/or algal biomass in South San Francisco Bay, CA, USA. Profiles of saturated, branched, and monounsaturated fatty acids had similar concentrations and patterns downcore. Total PAHs in a sediment core were on average greater than 20× higher above ∼200 cm than below, which corresponds roughly to the year 1900. Isomer ratios were consistent with a predominant petroleum combustion source for PAHs. Several individual PAHs exceeded sediment quality screening values. Negative correlations between petroleum contaminants and microbial and algal biomarkers – along with high trans/cis ratios of unsaturated FA, and principle component analysis of the PAH and fatty acid records – suggest a negative impacts of petroleum contamination, appearing early in the 20th century, on microbial and/or algal ecology at the site.

  11. One-Dimensional Convolutional Neural Network Land-Cover Classification of Multi-Seasonal Hyperspectral Imagery in the San Francisco Bay Area, California

    Directory of Open Access Journals (Sweden)

    Daniel Guidici

    2017-06-01

    Full Text Available In this study, a 1-D Convolutional Neural Network (CNN architecture was developed, trained and utilized to classify single (summer and three seasons (spring, summer, fall of hyperspectral imagery over the San Francisco Bay Area, California for the year 2015. For comparison, the Random Forests (RF and Support Vector Machine (SVM classifiers were trained and tested with the same data. In order to support space-based hyperspectral applications, all analyses were performed with simulated Hyperspectral Infrared Imager (HyspIRI imagery. Three-season data improved classifier overall accuracy by 2.0% (SVM, 1.9% (CNN to 3.5% (RF over single-season data. The three-season CNN provided an overall classification accuracy of 89.9%, which was comparable to overall accuracy of 89.5% for SVM. Both three-season CNN and SVM outperformed RF by over 7% overall accuracy. Analysis and visualization of the inner products for the CNN provided insight to distinctive features within the spectral-temporal domain. A method for CNN kernel tuning was presented to assess the importance of learned features. We concluded that CNN is a promising candidate for hyperspectral remote sensing applications because of the high classification accuracy and interpretability of its inner products.

  12. Defining competencies for education in health care value: recommendations from the University of California, San Francisco Center for Healthcare Value Training Initiative.

    Science.gov (United States)

    Moriates, Christopher; Dohan, Daniel; Spetz, Joanne; Sawaya, George F

    2015-04-01

    Leaders in medical education have increasingly called for the incorporation of cost awareness and health care value into health professions curricula. Emerging efforts have thus far focused on physicians, but foundational competencies need to be defined related to health care value that span all health professions and stages of training. The University of California, San Francisco (UCSF) Center for Healthcare Value launched an initiative in 2012 that engaged a group of educators from all four health professions schools at UCSF: Dentistry, Medicine, Nursing, and Pharmacy. This group created and agreed on a multidisciplinary set of comprehensive competencies related to health care value. The term "competency" was used to describe components within the larger domain of providing high-value care. The group then classified the competencies as beginner, proficient, or expert level through an iterative process and group consensus. The group articulated 21 competencies. The beginner competencies include basic principles of health policy, health care delivery, health costs, and insurance. Proficient competencies include real-world applications of concepts to clinical situations, primarily related to the care of individual patients. The expert competencies focus primarily on systems-level design, advocacy, mentorship, and policy. These competencies aim to identify a standard that may help inform the development of curricula across health professions training. These competencies could be translated into the learning objectives and evaluation methods of resources to teach health care value, and they should be considered in educational settings for health care professionals at all levels of training and across a variety of specialties.

  13. PRONÓSTICO DE LA RADIO ATENUACION TROSPOSFÉRICA POR LLUVIA PARA EL MUNICIPIO SAN FRANCISCO, ESTADO ZULIA, VENEZUELA, ENTRE 2016 Y 2018

    Directory of Open Access Journals (Sweden)

    José V. Castro V.

    2016-09-01

    Full Text Available El presente trabajo tiene como principal propósito pronosticar la radio atenuación troposférica por lluvia, también conocida como atenuación específica por lluvia, para el municipio San Francisco del estado Zulia, Venezuela, entre los años 2016 y 2018, utilizando el método ARIMA (Autoregressive Integrated Moving Average para series temporale, obtenidas a partir de datos de lluvia medidos en periodos diarios, mensuales y anuales. Mediante ARIMA, se determinó la intensidad de lluvia pronosticada, en mm/h, para los tres (3 años señalados, para seguidamente determinar la radio atenuación troposférica en dichos años. El procedimiento cumple con los requerimientos de estacionalidad y ciclicidad exigidos para ese tipo de pronósticos. Se observó que los niveles de radio atenuación troposférica más bajos se estiman ocurran aproximadamente para el periodo enero-abril, mientras que la radio atenuación más alta se prevé para el periodo julio-noviembre, con un pico en septiembre.

  14. Bringing Healthy Retail to Urban "Food Swamps": a Case Study of CBPR-Informed Policy and Neighborhood Change in San Francisco.

    Science.gov (United States)

    Minkler, Meredith; Estrada, Jessica; Thayer, Ryan; Juachon, Lisa; Wakimoto, Patricia; Falbe, Jennifer

    2018-04-09

    In urban "food swamps" like San Francisco's Tenderloin, the absence of full-service grocery stores and plethora of corner stores saturated with tobacco, alcohol, and processed food contribute to high rates of chronic disease. We explore the genesis of the Tenderloin Healthy Corner Store Coalition, its relationship with health department and academic partners, and its contributions to the passage and implementation of a healthy retail ordinance through community-based participatory research (CBPR), capacity building, and advocacy. The healthy retail ordinance incentivizes small stores to increase space for healthy foods and decrease tobacco and alcohol availability. Through Yin's multi-method case study analysis, we examined the partnership's processes and contributions to the ordinance within the framework of Kingdon's three-stage policymaking model. We also assessed preliminary outcomes of the ordinance, including a 35% increase in produce sales and moderate declines in tobacco sales in the first four stores participating in the Tenderloin, as well as a "ripple effect," through which non-participating stores also improved their retail environments. Despite challenges, CBPR partnerships led by a strong community coalition concerned with bedrock issues like food justice and neighborhood inequities in tobacco exposure may represent an important avenue for health equity-focused research and its translation into practice.

  15. Phytoplankton growth balanced by clam and zooplankton grazing and net transport into the low-salinity zone of the San Francisco Estuary

    Science.gov (United States)

    Kimmerer, Wim J.; Thompson, Janet K.

    2014-01-01

    We estimated the influence of planktonic and benthic grazing on phytoplankton in the strongly tidal, river-dominated northern San Francisco Estuary using data from an intensive study of the low salinity foodweb in 2006–2008 supplemented with long-term monitoring data. A drop in chlorophyll concentration in 1987 had previously been linked to grazing by the introduced clam Potamocorbula amurensis, but numerous changes in the estuary may be linked to the continued low chlorophyll. We asked whether phytoplankton continued to be suppressed by grazing and what proportion of the grazing was by benthic bivalves. A mass balance of phytoplankton biomass included estimates of primary production and grazing by microzooplankton, mesozooplankton, and clams. Grazing persistently exceeded net phytoplankton growth especially for larger cells, and grazing by microzooplankton often exceeded that by clams. A subsidy of phytoplankton from other regions roughly balanced the excess of grazing over growth. Thus, the influence of bivalve grazing on phytoplankton biomass can be understood only in the context of limits on phytoplankton growth, total grazing, and transport.

  16. Sexual Behavior, Risk Compensation, and HIV Prevention Strategies Among Participants in the San Francisco PrEP Demonstration Project: A Qualitative Analysis of Counseling Notes.

    Science.gov (United States)

    Carlo Hojilla, J; Koester, Kimberly A; Cohen, Stephanie E; Buchbinder, Susan; Ladzekpo, Deawodi; Matheson, Tim; Liu, Albert Y

    2016-07-01

    Pre-exposure prophylaxis (PrEP) is a viable HIV prevention strategy but risk compensation could undermine potential benefits. There are limited data that examine this phenomenon outside of clinical trials. We conducted a qualitative analysis of counseling notes from the San Francisco site of the US PrEP demonstration project to assess how men who have sex with men used PrEP as a prevention strategy and its impact on their sexual practices. Four major themes emerged from our analysis of 130 distinct notes associated with 26 participants. Prevention strategy decision-making was dynamic, often influenced by the context and perceived risk of a sexual encounter. Counselors noted that participants used PrEP in conjunction with other health promotion strategies like condoms, asking about HIV status of their sex partners, and seroadaptation. With few exceptions, existing risk reduction strategies were not abandoned upon initiation of PrEP. Risk-taking behavior was 'seasonal' and fluctuations were influenced by various personal, psychosocial, and health-related factors. PrEP also helped relieve anxiety regarding sex and HIV, particularly among serodiscordant partners. Understanding sexual decision-making and how PrEP is incorporated into existing prevention strategies can help inform future PrEP implementation efforts.

  17. Clusters of community exposure to coastal flooding hazards based on storm and sea level rise scenarios—implications for adaptation networks in the San Francisco Bay region

    Science.gov (United States)

    Hummel, Michelle; Wood, Nathan J.; Schweikert, Amy; Stacey, Mark T.; Jones, Jeanne; Barnard, Patrick L.; Erikson, Li H.

    2018-01-01

    Sea level is projected to rise over the coming decades, further increasing the extent of flooding hazards in coastal communities. Efforts to address potential impacts from climate-driven coastal hazards have called for collaboration among communities to strengthen the application of best practices. However, communities currently lack practical tools for identifying potential partner communities based on similar hazard exposure characteristics. This study uses statistical cluster analysis to identify similarities in community exposure to flooding hazards for a suite of sea level rise and storm scenarios. We demonstrate this approach using 63 jurisdictions in the San Francisco Bay region of California (USA) and compare 21 distinct exposure variables related to residents, employees, and structures for six hazard scenario combinations of sea level rise and storms. Results indicate that cluster analysis can provide an effective mechanism for identifying community groupings. Cluster compositions changed based on the selected societal variables and sea level rise scenarios, suggesting that a community could participate in multiple networks to target specific issues or policy interventions. The proposed clustering approach can serve as a data-driven foundation to help communities identify other communities with similar adaptation challenges and to enhance regional efforts that aim to facilitate adaptation planning and investment prioritization.

  18. The Collective Impact Model and Its Potential for Health Promotion: Overview and Case Study of a Healthy Retail Initiative in San Francisco.

    Science.gov (United States)

    Flood, Johnna; Minkler, Meredith; Hennessey Lavery, Susana; Estrada, Jessica; Falbe, Jennifer

    2015-10-01

    As resources for health promotion become more constricted, it is increasingly important to collaborate across sectors, including the private sector. Although many excellent models for cross-sector collaboration have shown promise in the health field, collective impact (CI), an emerging model for creating larger scale change, has yet to receive much study. Complementing earlier collaboration approaches, CI has five core tenets: a shared agenda, shared measurement systems, mutually reinforcing activities, continuous communication, and a central infrastructure. In this article, we describe the CI model and its key dimensions and constructs. We briefly compare CI to community coalition action theory and discuss our use of the latter to provide needed detail as we apply CI in a critical case study analysis of the Tenderloin Healthy Corner Store Coalition in San Francisco, California. Using Yin's multimethod approach, we illustrate how CI strategies, augmented by the community coalition action theory, are being used, and with what successes or challenges, to help affect community- and policy-level change to reduce tobacco and alcohol advertising and sales, while improving healthy, affordable, and sustainable food access. We discuss the strengths and weaknesses of CI as a framework for health promotion, as well as the benefits, challenges, and initial outcomes of the healthy retail project and its opportunities for scale-up. Implications for health promotion practice and research also are discussed. © 2015 Society for Public Health Education.

  19. Demanda de irrigação da cultura da uva na Bacia do Rio São Francisco Irrigation demand for grape crop in San Francisco River Basin

    Directory of Open Access Journals (Sweden)

    Wallisson da S. Freitas

    2006-09-01

    Full Text Available Visando subsidiar o planejamento de projetos agrícolas para o dimensionamento de projetos de irrigação e a gestão de recursos hídricos, estimou-se e se espacializou a demanda de irrigação da videira (Vitis vinifera L., cv. Itália, na bacia do Rio São Francisco. Utilizaram-se séries históricas de dados de 81 estações climáticas distribuídas na bacia. Para cada estação calculou-se os valores, máximos diários e o total anual, da evapotranspiração de referência (ETo, da evapotranspiração da cultura (ETc, da demanda suplementar da cultura e da demanda suplementar de irrigação (este com eficiência de 70%. Com base nos resultados obtidos, concluiu-se que: (a a ETc máxima diária variou, em grande parte da bacia, de 4,5 a 5,7 mm d-1, tendo média anual de 943 mm; (b em média, a demanda anual suplementar da cultura foi 839,5 mm, equivalente a 103,5 mm inferior à ETc; (c o fato do sistema funcionar com 70% de eficiência, em vez de 90%, implica em acréscimo estimado de 18.808.755 m³ de água por ano, somente nas microrregiões de Juazeiro, BA e Petrolina, PE.The irrigation water demand of the grapevine (Vitis vinifera L. cv. Italy was estimated and spatialized in San Francisco River Basin, in order to subsidize the agricultural project planning and water resource management. Historical data series relative to 81 climatic stations distributed throughout the basin were used. The maximum daily values and the annual total values of the reference evapotranspiration (ETo, crop evapotranspiration (ETc, supplementary demand of the crop and the supplementary irrigation demand (70% efficiency were calculated for each station. According to the results, the following conclusions were drawn: (a in a large area of the basin, the maximum daily ETc varied from 4.5 to 5.7 mm d-1, with an annual mean of 943 mm; (b the supplementary annual demand of the crop averaged 839.5 mm, corresponding to 103.5 mm less than ETc; and (c the irrigation

  20. Water quality in South San Francisco Bay, California: current condition and potential issues for the South Bay Salt Pond Restoration Project.

    Science.gov (United States)

    Grenier, J Letitia; Davis, Jay A

    2010-01-01

    The SBSPRP is an extensive tidal wetland restoration project that is underway at the margin of South San Francisco Bay, California. The Project, which aims to restore former salt ponds to tidal marsh and manage other ponds for water bird support, is taking place in the context of a highly urbanized watershed and an Estuary already impacted by chemical contaminants. There is an intimate relationship between water quality in the watershed, the Bay, and the transitional wetland areas where the Project is located. The Project seeks to restore habitat for endangered and endemic species and to provide recreational opportunities for people. Therefore, water quality and bioaccumulation of contaminants in fish and wildlife is an important concern for the success of the Project. Mercury, PCBs, and PBDEs are the persistent contaminants of greatest concern in the region. All of these contaminants are present at elevated concentrations both in the abiotic environment and in wildlife. Dioxins, pyrethroids, PAHs, and selenium are also problematic. Organochlorine insecticides have historically impacted the Bay, and they remain above thresholds for concern in a small proportion of samples. Emerging contaminants, such as PFCs and non-PBDE flame retardants, are also an important water quality issue. Beyond chemical pollutants, other concerns for water quality in South San Francisco Bay exist, and include biological constituents, especially invasive species, and chemical attributes, such as dissolved oxygen and salinity. Future changes, both from within the Project and from the Bay and watershed, are likely to influence water quality in the region. Project actions to restore wetlands could worsen, improve, or not affect the already impaired water quality in South Bay. Accelerated erosion of buried sediment as a consequence of Project restoration actions is a potentially serious regional threat to South Bay water and sediment quality. Furthermore, the planned restoration of salt ponds

  1. Wind-enhanced resuspension in the shallow waters of South San Francisco Bay: Mechanisms and potential implications for cohesive sediment transport

    Science.gov (United States)

    Brand, Andreas; Lacy, Jessica R.; Hsu, Kevin; Hoover, Daniel; Gladding, Steve; Stacey, Mark T.

    2010-01-01

    We investigated the driving forces of sediment dynamics at the shoals in South San Francisco Bay. Two stations were deployed along a line perpendicular to a 14 m deep channel, 1000 and 2000 m from the middle of the channel. Station depths were 2.59 and 2.19 m below mean lower low water, respectively. We used acoustic Doppler velocimeters for the simultaneous determination of current velocities, turbulence, sediment concentration and fluxes. Maximum current shear velocities were 0.015 m s−1 at the station further from the channel (closer to the shore) and 0.02 m s−1 at the station closer to the channel. Peak wave-induced shear velocities exceeded 0.015 m s−1 at both stations. Maximum sediment concentrations were around 30 g m−3 during calm periods (root mean square wave height −3 and sediment fluxes were 5 times higher than in calm conditions (0.02 g m−2 s−1 versus >0.10 g m−2 s−1) at the station further from the channel 0.36 m above the bed. Closer to the channel, sediment concentrations and vertical fluxes due to wind wave resuspension were persistently lower (maximum concentrations around 50 g m−3 and maximum fluxes around 0.04 g m−2 s−1). Most resuspension events occurred during flood tides that followed wave events during low water. Although wave motions are able to resuspend sediment into the wave boundary layer at low tide, the observed large increases in sediment fluxes are due to the nonlinear interaction of wind waves and the tidal currents.

  2. Polypharmacy, Infectious Diseases, Sexual Behavior, and Psychophysical Health Among Anabolic Steroid-Using Homosexual and Heterosexual Gym Patrons in San Francisco's Castro District.

    Science.gov (United States)

    Ip, Eric J; Yadao, Michael A; Shah, Bijal M; Doroudgar, Shadi; Perry, Paul J; Tenerowicz, Michael J; Newsom, Lindsay; Mann, Amber A; Mkrtchyan, Hermine; Pope, Harrison G

    2017-06-07

    Limited studies based in England and Australia reported misuse of anabolic-androgenic steroids (AAS) among homosexual men to enhance body image. Anecdotally, AAS are also being misused by homosexual men in the United States. Since many AAS and certain performance enhancing drugs (PEDs) are administered via injection, this poses a potential vector for the spread of infectious disease in an already at-risk population. This study compared and contrasted homosexual and heterosexual male gym clients regarding use of AAS and PEDs, use of alcohol and illicit drugs, seroprevalence of infectious disease, engagement in risky injection practices and sexual behaviors, and presence of psychiatric conditions. Recruitment and data collection occurred outside four exercise gyms in the San Francisco Castro District area between October 25, 2014 and March 10, 2015. Two hundred and twenty homosexual men and 73 heterosexual men completed the 114-item cross-sectional survey. Ten percent of homosexual men reported lifetime AAS use. Homosexual men had almost four times more sexual partners and were over 14 times more likely to knowingly have unprotected intercourse with a known HIV positive person than heterosexual men. In addition, a quarter of homosexual men who injected drugs admitted to sharing used syringes or needles with another person. Conclusions/Importance: The current study is the first to confirm AAS use among homosexual men in the United States. Homosexual men partook in high-risk sexual behaviors and injection practices which may place them at greater risks for contracting and spreading HIV and other infectious diseases.

  3. Assessing toxicant effects in a complex estuary--A case study of effects of silver on reproduction in the bivalve, Potamocurbula amurensis, in San Francisco Bay

    Science.gov (United States)

    Brown, Cynthia L.; Parchaso, Francis; Thompson, Janet K.; Luoma, Samuel N.

    2003-01-01

    Contaminant exposures in natural systems can be highly variable. This variability is superimposed upon cyclic variability in biological processes. Together, these factors can confound determination of contaminant effects. Long term, multidisciplined studies with high frequency sampling can be effective in overcoming such obstacles. While studying trace metal contamination in the tissues of the clam, Potamocorbula amurensis, in the northern reach of San Francisco Bay, an episode of high Ag concentrations was identified (maximum of 5.5 µg g−1) at two mid-estuary sites. High concentrations were not seen in clams up-estuary (maximum of 1.92 µg g−1) from these sites and were reduced down-estuary (maximum of 2.67 µg g−1). Silver is not common naturally in the environment, so its elevated presence is usually indicative of anthropogenic influences such as municipal and industrial discharge. Monthly sampling of reproductive status of clams characterized the reproductive cycle and differences in the patterns of reproductive activity that corresponded to changes in Ag tissue concentrations. The proportion of reproductive clams was less than 60% during periods when tissue concentrations were high (generally >2 µg g−1). When tissue concentrations of Ag decreased (≤1 µg g−1), the proportion of reproductive clams was 80 to 100%. A comparison between the annual proportion of reproductive clams and annual Ag tissue concentrations showed a significant negative correlation. No other measured environmental variables were correlated with reproductive impairment. The weight-of-evidence approach strongly supports a cause and effect relationship between Ag contamination and reduced reproductive activity in P. amurensis.

  4. Assessing toxicant effects in a complex estuary: A case study of effects of silver on reproduction in the bivalve, Potamocorbula amurensis, in San Francisco Bay

    Science.gov (United States)

    Brown, C.L.; Parchaso, F.; Thompson, J.K.; Luoma, S.N.

    2003-01-01

    Contaminant exposures in natural systems can be highly variable. This variability is superimposed upon cyclic variability in biological processes. Together, these factors can confound determination of contaminant effects. Long term, multidisciplined studies with high frequency sampling can be effective in overcoming such obstacles. While studying trace metal contamination in the tissues of the clam, Potamocorbula amurensis, in the northern reach of San Francisco Bay, an episode of high Ag concentrations was identified (maximum of 5.5 ??g g-1) at two mid-estuary sites. High concentrations were not seen in clams up-estuary (maximum of 1.92 ??g g-1) from these sites and were reduced down-estuary (maximum of 2.67 ??g g-1). Silver is not common naturally in the environment, so its elevated presence is usually indicative of anthropogenic influences such as municipal and industrial discharge. Monthly sampling of reproductive status of clams characterized the reproductive cycle and differences in the patterns of reproductive activity that corresponded to changes in Ag tissue concentrations. The proportion of reproductive clams was less than 60% during periods when tissue concentrations were high (generally >2 ??g g-1). When tissue concentrations of Ag decreased (???1 ??g g-1), the proportion of reproductive clams was 80 to 100%. A comparison between the annual proportion of reproductive clams and annual Ag tissue concentrations showed a significant negative correlation. No other measured environmental variables were correlated with reproductive impairment. The weight-of-evidence approach strongly supports a cause and effect relationship between Ag contamination and reduced reproductive activity in P. amurensis.

  5. Climate change negotiation simulations for students: responses across gender and age.A case study: San Francisco State University World Climate Exercises

    Science.gov (United States)

    Rasheva, E. A.

    2015-12-01

    For decades, role-play and simulation exercises have been utilized for learning and policy decision making. While the power of Model UN simulations in building first-person experience and understanding of complex international issues is well known, the effectiveness of simulations for inspiring citizen engagement in scientific public-policy issues is little studied. My work hypothesizes that climate-change negotiation simulations can enhance students' scientific literacy and policy advocacy. It aims to determine how age and gender influence the responsiveness of students to such simulations. During the 2015 fall semester, I am conducting World Climate exercises for fellow graduate and undergraduate students at San Francisco State University. At the end of the exercise, I will have collected the responses to an anonymous questionnaire in which the participants indicate age and gender. The questionnaire asks participants to describe their hopes and fears for the future and to propose public and personal actions for achieving a strong climate change agreement. I am tracking differences to determine whether participants' age and gender correlate with particular patterns of feeling and thinking. My future research will aim to determine whether and how strongly the World Climate Exercise has affected participants' actual policy engagement. This work will also reflect on my experiences as a World Climate facilitator. I will describe the facilitation process and then discuss some of my observations from the sessions. I will specify the challenges I have encountered and suggest strategies that can strengthen the learning process. World Climate is a computer-simulation-based climate change negotiations role-playing exercise developed by Climate Interactive in partnership with the System Dynamics Group at the MIT Sloan School of Management.

  6. Creation of a retrospective job-exposure matrix using surrogate measures of exposure for a cohort of US career firefighters from San Francisco, Chicago and Philadelphia.

    Science.gov (United States)

    Dahm, Matthew M; Bertke, Stephen; Allee, Steve; Daniels, Robert D

    2015-09-01

    To construct a cohort-specific job-exposure matrix (JEM) using surrogate metrics of exposure for a cancer study on career firefighters from the Chicago, Philadelphia and San Francisco Fire Departments. Departmental work history records, along with data on historical annual fire-runs and hours, were collected from 1950 to 2009 and coded into separate databases. These data were used to create a JEM based on standardised job titles and fire apparatus assignments using several surrogate exposure metrics to estimate firefighters' exposure to the combustion byproducts of fire. The metrics included duration of exposure (cumulative time with a standardised exposed job title and assignment), fire-runs (cumulative events of potential fire exposure) and time at fire (cumulative hours of potential fire exposure). The JEM consisted of 2298 unique job titles alongside 16,174 fire apparatus assignments from the three departments, which were collapsed into 15 standardised job titles and 15 standardised job assignments. Correlations were found between fire-runs and time at fires (Pearson coefficient=0.92), duration of exposure and time at fires (Pearson coefficient=0.85), and duration of exposure and fire-runs (Pearson coefficient=0.82). Total misclassification rates were found to be between 16-30% when using duration of employment as an exposure surrogate, which has been traditionally used in most epidemiological studies, compared with using the duration of exposure surrogate metric. The constructed JEM successfully differentiated firefighters based on gradient levels of potential exposure to the combustion byproducts of fire using multiple surrogate exposure metrics. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  7. Conservation of Native Fishes of the San Francisco Estuary: Considerations for Artificial Propagation of Chinook Salmon, Delta Smelt, and Green Sturgeon

    Directory of Open Access Journals (Sweden)

    Joshua A. Israel

    2011-04-01

    Full Text Available Many native fishes in the San Francisco Estuary and its watersheds have reached all-time low abundances. Some of these declining species (e.g., Chinook salmon Oncorhynchus tschawytscha have been under artificial propagation for decades. For others (e.g., delta smelt, Hypomesus transpacificus, and green sturgeon, Acipenser medirostris, this management option is just beginning to be discussed and implemented. Propagation strategies, in which organisms spend some portion of their lives in captivity, pose well-documented genetic and ecological threats to natural populations. Negative impacts of propagation have been documented for all Central Valley Chinook salmon runs, but limited efforts have been made to adapt hatchery operations to minimize the genetic and ecological threats caused by propagated fishes. A delta smelt propagation program is undergoing intensive design and review for operations and monitoring. However, if limiting factors facing this species in its estuarine habitat are not effectively addressed, captive propagation may not be a useful conservation approach, regardless of how carefully the propagation activity is designed or monitored. Scientifically defensible, ecologically based restoration programs that include monitoring and research aimed at quantifying natural population vital rates should be fully implemented before there is any attempt to supplement natural populations of delta smelt. Green sturgeon are also likely to face risks from artificial propagation if a large–scale program is implemented before this species’ limiting factors are better understood. In each of these cases, restoring habitats, and reducing loss from human actions, are likely to be the best strategy for rebuilding and supporting self–sustaining populations.

  8. Em busca da estrutura sócio-espacial da redução de San Francisco de Borja: a sobrevivência do patrimônio arqueológico

    OpenAIRE

    Bisonhim, Kelli

    2011-01-01

    O objeto desta pesquisa foi a missão de San Francisco de Borja, erigida em 1682. A proposta deste trabalho constituiu em sugerir uma carta de potencial arqueológico para a moderna cidade de São Borja/RS. Para isso, buscou-se verificar a distribuição espacial da malha urbana atual sobreposta a antiga malha reducional. Observando os modelos coloniais para a instalação de cidades européias, e ainda os “padrões” seguidos para erigir as Reduções Jesuíticas, procurou-se compreender a utilização do ...

  9. Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California: 2014

    Science.gov (United States)

    Cain, Daniel J.; Thompson, Janet K.; Crauder, Jeff; Parcheso, Francis; Stewart, Robin; Kleckner, Amy E.; Dyke, Jessica; Hornberger, Michelle I.; Luoma, Samuel N.

    2015-01-01

    Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer (km) south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in South San Francisco Bay, Calif. This report includes the data collected by U.S. Geological Survey (USGS) scientists for the period January 2014 to December 2014. These append to long-term datasets extending back to 1974, and serve as the basis for the City of Palo Alto’s Near-Field Receiving Water Monitoring Program, initiated in 1994. 

  10. Evaluating tidal marsh sustainability in the face of sea-level rise: a hybrid modeling approach applied to San Francisco Bay.

    Directory of Open Access Journals (Sweden)

    Diana Stralberg

    Full Text Available Tidal marshes will be threatened by increasing rates of sea-level rise (SLR over the next century. Managers seek guidance on whether existing and restored marshes will be resilient under a range of potential future conditions, and on prioritizing marsh restoration and conservation activities.Building upon established models, we developed a hybrid approach that involves a mechanistic treatment of marsh accretion dynamics and incorporates spatial variation at a scale relevant for conservation and restoration decision-making. We applied this model to San Francisco Bay, using best-available elevation data and estimates of sediment supply and organic matter accumulation developed for 15 Bay subregions. Accretion models were run over 100 years for 70 combinations of starting elevation, mineral sediment, organic matter, and SLR assumptions. Results were applied spatially to evaluate eight Bay-wide climate change scenarios.Model results indicated that under a high rate of SLR (1.65 m/century, short-term restoration of diked subtidal baylands to mid marsh elevations (-0.2 m MHHW could be achieved over the next century with sediment concentrations greater than 200 mg/L. However, suspended sediment concentrations greater than 300 mg/L would be required for 100-year mid marsh sustainability (i.e., no elevation loss. Organic matter accumulation had minimal impacts on this threshold. Bay-wide projections of marsh habitat area varied substantially, depending primarily on SLR and sediment assumptions. Across all scenarios, however, the model projected a shift in the mix of intertidal habitats, with a loss of high marsh and gains in low marsh and mudflats.Results suggest a bleak prognosis for long-term natural tidal marsh sustainability under a high-SLR scenario. To minimize marsh loss, we recommend conserving adjacent uplands for marsh migration, redistributing dredged sediment to raise elevations, and concentrating restoration efforts in sediment-rich areas

  11. LINEAMIENTOS PARA LA PLANEACIÓN DEL TURISMO SOSTENIBLE EN EL CORREGIMIENTO DE SAN FRANCISCO DE ASÍS (MUNICIPIO DE ACANDÍ, CHOCÓ, COLOMBIA

    Directory of Open Access Journals (Sweden)

    ROLDÁN CARVAJAL CARLOS DANIEL

    2012-07-01

    Full Text Available Este artículo presenta unos lineamientos de gestión importantes para llevar a cabo un proceso de planeación turística en el corregimiento de San Francisco de Asís, los cuales fueron desarrollados a partir de la noción conceptual de turismo sostenible y la participación de los pobladores locales. Para este caso, se consideró el método de la investigación participativa, se utilizaron técnicas de la etnografía y se implementaron talleres con la comunidad. Como resultado principal se propone la consolidación de cuatro componentes, el socio- político, el socio- cultural, el socio- ecológico y el socio- económico, que deberán gestionarse de manera integral para alcanzar una verdadera sostenibilidad turística en este territorio. En el primer componente, se esboza un proceso participativo que deberá llevarse a cabo entre los diferentes actores- sectores involucrados; en el segundo, se plantea fortalecer el tejido social y valorizar las tradiciones culturales para integrarlas adecuadamente con las actividades turísticas; en el tercero, se propone una conservación ambiental integral en todo el territorio y como una obligación de todos los actores- sectores involucrados, incluyendo también a los turistas; por último, en el cuarto componente, se recomienda la generación de más oportunidades y de bienestar general para toda la población local, con el fin de evitar la proliferación de un turismo segregado. Como conclusión general, se proyecta que la implementación de estos lineamientos permitirá avanzar, desde lo práctico, en el desarrollo de un auténtico turismo sostenible que ayudará a mejorar las condiciones de vida de la población local y a conservar los valiosos recursos naturales y culturales que existen en este territorio.

  12. Macroinvertebrate Prey Availability and Fish Diet Selectivity in Relation to Environmental Variables in Natural and Restoring North San Francisco Bay Tidal Marsh Channels

    Directory of Open Access Journals (Sweden)

    Emily R. Howe

    2014-03-01

    Full Text Available Tidal marsh wetlands provide important foraging habitat for a variety of estuarine fishes. Prey organisms include benthic–epibenthic macroinvertebrates, neustonic arthropods, and zooplankton. Little is known about the abundance and distribution of interior marsh macroinvertebrate communities in the San Francisco Estuary (estuary. We describe seasonal, regional, and site variation in the composition and abundance of neuston and benthic–epibenthic macroinvertebrates that inhabit tidal marsh channels, and relate these patterns to environmental conditions. We also describe spatial and temporal variation in diets of marsh-associated inland silverside, yellowfin goby, and western mosquitofish. Fish and invertebrates were sampled quarterly from October 2003 to June 2005 at six marsh sites located in three river systems of the northern estuary: Petaluma River, Napa River, and  the west Delta. Benthic/epibenthic macroinvertebrates and neuston responded to environmental variables related to seasonal changes (i.e., temperature, salinity, as well as those related to marsh structure (i.e., vegetation, channel edge. The greatest variation in abundance occurred seasonally for neuston and spatially for benthic–epibenthic organisms, suggesting that each community responds to different environmental drivers. Benthic/epibenthic invertebrate abundance and diversity was lowest in the west Delta, and increased with increasing salinity. Insect abundance increased during the spring and summer, while Collembolan (springtail abundance increased during the winter. Benthic/epibenthic macroinvertebrates dominated fish diets, supplemented by insects, with zooplankton playing a minor role. Diet compositions of the three fish species overlapped considerably, with strong selection indicated for epibenthic crustaceans—a surprising result given the typical classification of Menidia beryllina as a planktivore, Acanthogobius flavimanus as a benthic predator, and Gambusia

  13. Computational Approach for Improving Three-Dimensional Sub-Surface Earth Structure for Regional Earthquake Hazard Simulations in the San Francisco Bay Area

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, A. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-25

    In our Exascale Computing Project (ECP) we seek to simulate earthquake ground motions at much higher frequency than is currently possible. Previous simulations in the SFBA were limited to 0.5-1 Hz or lower (Aagaard et al. 2008, 2010), while we have recently simulated the response to 5 Hz. In order to improve confidence in simulated ground motions, we must accurately represent the three-dimensional (3D) sub-surface material properties that govern seismic wave propagation over a broad region. We are currently focusing on the San Francisco Bay Area (SFBA) with a Cartesian domain of size 120 x 80 x 35 km, but this area will be expanded to cover a larger domain. Currently, the United States Geologic Survey (USGS) has a 3D model of the SFBA for seismic simulations. However, this model suffers from two serious shortcomings relative to our application: 1) it does not fit most of the available low frequency (< 1 Hz) seismic waveforms from moderate (magnitude M 3.5-5.0) earthquakes; and 2) it is represented with much lower resolution than necessary for the high frequency simulations (> 5 Hz) we seek to perform. The current model will serve as a starting model for full waveform tomography based on 3D sensitivity kernels. This report serves as the deliverable for our ECP FY2017 Quarter 4 milestone to FY 2018 “Computational approach to developing model updates”. We summarize the current state of 3D seismic simulations in the SFBA and demonstrate the performance of the USGS 3D model for a few selected paths. We show the available open-source waveform data sets for model updates, based on moderate earthquakes recorded in the region. We present a plan for improving the 3D model utilizing the available data and further development of our SW4 application. We project how the model could be improved and present options for further improvements focused on the shallow geotechnical layers using dense passive recordings of ambient and human-induced noise.

  14. Assessment of planetary geologic mapping techniques for Mars using terrestrial analogs: The SP Mountain area of the San Francisco Volcanic Field, Arizona

    Science.gov (United States)

    Tanaka, K.L.; Skinner, J.A.; Crumpler, L.S.; Dohm, J.M.

    2009-01-01

    We photogeologically mapped the SP Mountain region of the San Francisco Volcanic Field in northern Arizona, USA to evaluate and improve the fidelity of approaches used in geologic mapping of Mars. This test site, which was previously mapped in the field, is chiefly composed of Late Cenozoic cinder cones, lava flows, and alluvium perched on Permian limestone of the Kaibab Formation. Faulting and folding has deformed the older rocks and some of the volcanic materials, and fluvial erosion has carved drainage systems and deposited alluvium. These geologic materials and their formational and modificational histories are similar to those for regions of the Martian surface. We independently prepared four geologic maps using topographic and image data at resolutions that mimic those that are commonly used to map the geology of Mars (where consideration was included for the fact that Martian features such as lava flows are commonly much larger than their terrestrial counterparts). We primarily based our map units and stratigraphic relations on geomorphology, color contrasts, and cross-cutting relationships. Afterward, we compared our results with previously published field-based mapping results, including detailed analyses of the stratigraphy and of the spatial overlap and proximity of the field-based vs. remote-based (photogeologic) map units, contacts, and structures. Results of these analyses provide insights into how to optimize the photogeologic mapping of Mars (and, by extension, other remotely observed planetary surfaces). We recommend the following: (1) photogeologic mapping as an excellent approach to recovering the general geology of a region, along with examination of local, high-resolution datasets to gain insights into the complexity of the geology at outcrop scales; (2) delineating volcanic vents and lava-flow sequences conservatively and understanding that flow abutment and flow overlap are difficult to distinguish in remote data sets; (3) taking care to

  15. Pre-exposure Prophylaxis (PrEP) Use, Seroadaptation, and Sexual Behavior Among Men Who Have Sex with Men, San Francisco, 2004-2014.

    Science.gov (United States)

    Chen, Yea-Hung; Snowden, Jonathan M; McFarland, Willi; Raymond, H Fisher

    2016-12-01

    The Food and Drug Administration approved pre-exposure prophylaxis (PrEP) to prevent HIV infection, and the Centers for Disease Control and Prevention has presented PrEP as a prevention option for groups at high risk such as men who have sex with men (MSM). Intervention data provide some information on how PrEP affects sexual behavior of MSM in trials, open label extensions, or clinics. However, it is unclear whether sexual risk and preventive behavioral patterns are changing in the population as a whole as PrEP becomes more widely available, whether due to PrEP use or other factors. We examined trends in PrEP use, numbers of condomless anal sex partners, consistent condom use, and seroadaptive strategies in San Francisco-a city which has actively promoted PrEP-using data from National HIV Behavioral Surveillance (NHBS). NHBS recruited 1211, 383, 373, and 268 HIV-negative MSM in 2004, 2008, 2011, and 2014, respectively. PrEP use increased from zero in 2004, 2008, and 2011 to 9.6 % in 2014. The proportion of men with no condomless anal sex partners dropped from 60.6 % in 2004, to 58.2 % in 2008, to 54.2 % in 2011, to 40.2 % in 2014. Consistent condom use decreased from 36.8 % in 2004, and 30.5 % in 2008 and 2011, to 18.3 % in 2014. PrEP's introduction and scale-up enters in a pre-existing trend of decreasing condom use and increasing sexually transmitted infections among MSM which may be accelerating in recent years. While PrEP use should be scaled up as a prevention option among those who would benefit most, we believe that public health officials need to be realistic about the possibility that condom use could very well continue to decline as PrEP use increases, and to an extent that may not be directly or indirectly offset by PrEP.

  16. Vehicle speed prediction via a sliding-window time series analysis and an evolutionary least learning machine: A case study on San Francisco urban roads

    Directory of Open Access Journals (Sweden)

    Ladan Mozaffari

    2015-06-01

    Full Text Available The main goal of the current study is to take advantage of advanced numerical and intelligent tools to predict the speed of a vehicle using time series. It is clear that the uncertainty caused by temporal behavior of the driver as well as various external disturbances on the road will affect the vehicle speed, and thus, the vehicle power demands. The prediction of upcoming power demands can be employed by the vehicle powertrain control systems to improve significantly the fuel economy and emission performance. Therefore, it is important to systems design engineers and automotive industrialists to develop efficient numerical tools to overcome the risk of unpredictability associated with the vehicle speed profile on roads. In this study, the authors propose an intelligent tool called evolutionary least learning machine (E-LLM to forecast the vehicle speed sequence. To have a practical evaluation regarding the efficacy of E-LLM, the authors use the driving data collected on the San Francisco urban roads by a private Honda Insight vehicle. The concept of sliding window time series (SWTS analysis is used to prepare the database for the speed forecasting process. To evaluate the performance of the proposed technique, a number of well-known approaches, such as auto regressive (AR method, back-propagation neural network (BPNN, evolutionary extreme learning machine (E-ELM, extreme learning machine (ELM, and radial basis function neural network (RBFNN, are considered. The performances of the rival methods are then compared in terms of the mean square error (MSE, root mean square error (RMSE, mean absolute percentage error (MAPE, median absolute percentage error (MDAPE, and absolute fraction of variances (R2 metrics. Through an exhaustive comparative study, the authors observed that E-LLM is a powerful tool for predicting the vehicle speed profiles. The outcomes of the current study can be of use for the engineers of automotive industry who have been

  17. Toxicology findings in cases of hanging in the City and County of San Francisco over the 3-year period from 2011 to 2013.

    Science.gov (United States)

    San Nicolas, A C; Lemos, N P

    2015-10-01

    In postmortem cases where the cause of death is hanging, toxicological analyses may be considered unnecessary by some medical examiners, toxicologists, and other persons involved in medico-legal investigations because the cause of death seems "obvious." To ascertain if toxicological analyses are necessary when the cause of death is hanging, all 102 hanging cases (25 females; 77 males) from 2011 to 2013 that came under the jurisdiction of the San Francisco Office of the Chief Medical Examiner were examined from a total of 3912 sudden, unexpected, or violent death cases in the same period. Suicide was the manner of death in 99 of these cases, with two accidental and one undetermined death. The average age of decedents was 43.9 years (median 41), the youngest was an 11-year old male and the oldest was an 86-year old female. Of the 102 cases, 33 had negative toxicology while 69 cases had at least one positive toxicology result. Females were equally likely to have negative or positive results (12 and 13 cases respectively), but males were 37.5% more likely to have positive toxicology (n=56) rather than negative toxicology (n=21). For females, alcohol, mirtazapine, venlafaxine, and trazodone were the top psychoactive substances in peripheral blood while THC, cocaine, hydrocodone, bupropion, olanzapine, doxylamine, quetiapine and dextromethorphan were also reported. For males, alcohol, THC, cocaine, amphetamine, methamphetamine, bupropion, and diphenhydramine were the top psychoactive substances in blood, but several other drugs were also found in individual cases. Our study of hanging cases over a 3-year period support the idea that complete postmortem toxicology investigation of hangings should be performed, even when the "obvious" cause of death is asphyxia due to hanging. Many of these cases involved psychoactive substances (most often alcohol and cannabis), and having such knowledge provides a better understanding of the circumstances surrounding the decedent's death

  18. Status and understanding of groundwater quality in the North San Francisco Bay Shallow Aquifer study unit, 2012; California GAMA Priority Basin Project (ver. 1.1, February 2018)

    Science.gov (United States)

    Bennett, George L.

    2017-07-20

    Groundwater quality in the North San Francisco Bay Shallow Aquifer study unit (NSF-SA) was investigated as part of the Priority Basin Project of the California Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is in Marin, Mendocino, Napa, Solano, and Sonoma Counties and included two physiographic study areas: the Valleys and Plains area and the surrounding Highlands area. The NSF-SA focused on groundwater resources used for domestic drinking water supply, which generally correspond to shallower parts of aquifer systems than that of groundwater resources used for public drinking water supply in the same area. The assessments characterized the quality of untreated groundwater, not the quality of drinking water.This study included three components: (1) a status assessment, which characterized the status of the quality of the groundwater resources used for domestic supply for 2012; (2) an understanding assessment, which evaluated the natural and human factors potentially affecting water quality in those resources; and (3) a comparison between the groundwater resources used for domestic supply and those used for public supply.The status assessment was based on data collected from 71 sites sampled by the U.S. Geological Survey for the GAMA Priority Basin Project in 2012. To provide context, concentrations of constituents measured in groundwater were compared to U.S. Environmental Protection Agency (EPA) and California State Water Resources Control Board Division of Drinking Water regulatory and non-regulatory benchmarks for drinking-water quality. The status assessment used a grid-based method to estimate the proportion of the groundwater resources that has concentrations of water-quality constituents approaching or above benchmark concentrations. This method provides statistically unbiased results at the study-area scale and permits comparisons to other GAMA Priority Basin Project study areas.In the NSF-SA study unit as a whole, inorganic

  19. Evaluation of social attraction measures to establish Forster’s tern (Sterna forsteri) nesting colonies for the South Bay Salt Pond Restoration Project, San Francisco Bay, California—2017 Annual Report

    Science.gov (United States)

    Hartman, C. Alex; Ackerman, Joshua T.; Herzog, Mark P.; Wang, Yiwei; Strong, Cheryl

    2018-05-31

    Forster’s terns (Sterna forsteri), historically one of the most numerous colonial-breeding waterbirds in South San Francisco Bay, California, have had recent decreases in the number of nesting colonies and overall breeding population size. The South Bay Salt Pond (SBSP) Restoration Project aims to restore 50–90 percent of former salt evaporation ponds to tidal marsh habitat in South San Francisco Bay. This restoration will remove much of the historical island nesting habitat used by Forster’s terns, American avocets (Recurvirostra americana), and other waterbirds. To address this issue, the SBSP Restoration Project organized the construction of new nesting islands in managed ponds that will not be restored to tidal marsh, thereby providing enduring island nesting habitat for waterbirds. In 2012, 16 new islands were constructed in Pond A16 in the Alviso complex of the Don Edwards San Francisco Bay National Wildlife Refuge, increasing the number of islands in this pond from 4 to 20. However, despite a history of nesting on the four historical islands in Pond A16 before 2012, no Forster’s terns have nested in Pond A16 since the new islands were constructed.In 2017, we used social attraction measures (decoys and electronic call systems) to attract Forster’s terns to islands within Pond A16 to re-establish nesting colonies. We maintained these systems from March through August 2017. To evaluate the effect of these social attraction measures, we also completed waterbird surveys between April and August, where we recorded the number and location of all Forster’s terns and other waterbirds using Pond A16, and monitored waterbird nests. We compared bird survey and nest monitoring data collected in 2017 to data collected in 2015 and 2016, prior to the implementation of social attraction measures, allowing for direct evaluation of social attraction efforts on Forster’s terns.To increase the visibility and stakeholder involvement of this project, we engaged in

  20. Simulation of climate change in San Francisco Bay Basins, California: Case studies in the Russian River Valley and Santa Cruz Mountains

    Science.gov (United States)

    Flint, Lorraine E.; Flint, Alan L.

    2012-01-01

    As a result of ongoing changes in climate, hydrologic and ecologic effects are being seen across the western United States. A regional study of how climate change affects water resources and habitats in the San Francisco Bay area relied on historical climate data and future projections of climate, which were downscaled to fine spatial scales for application to a regional water-balance model. Changes in climate, potential evapotranspiration, recharge, runoff, and climatic water deficit were modeled for the Bay Area. In addition, detailed studies in the Russian River Valley and Santa Cruz Mountains, which are on the northern and southern extremes of the Bay Area, respectively, were carried out in collaboration with local water agencies. Resource managers depend on science-based projections to inform planning exercises that result in competent adaptation to ongoing and future changes in water supply and environmental conditions. Results indicated large spatial variability in climate change and the hydrologic response across the region; although there is warming under all projections, potential change in precipitation by the end of the 21st century differed according to model. Hydrologic models predicted reduced early and late wet season runoff for the end of the century for both wetter and drier future climate projections, which could result in an extended dry season. In fact, summers are projected to be longer and drier in the future than in the past regardless of precipitation trends. While water supply could be subject to increased variability (that is, reduced reliability) due to greater variability in precipitation, water demand is likely to steadily increase because of increased evapotranspiration rates and climatic water deficit during the extended summers. Extended dry season conditions and the potential for drought, combined with unprecedented increases in precipitation, could serve as additional stressors on water quality and habitat. By focusing on the

  1. Evaluation Methodologies for Information Management Systems; Building Digital Tobacco Industry Document Libraries at the University of California, San Francisco Library/Center for Knowledge Management; Experiments with the IFLA Functional Requirements for Bibliographic Records (FRBR); Coming to Term: Designing the Texas Email Repository Model.

    Science.gov (United States)

    Morse, Emile L.; Schmidt, Heidi; Butter, Karen; Rider, Cynthia; Hickey, Thomas B.; O'Neill, Edward T.; Toves, Jenny; Green, Marlan; Soy, Sue; Gunn, Stan; Galloway, Patricia

    2002-01-01

    Includes four articles that discuss evaluation methods for information management systems under the Defense Advanced Research Projects Agency; building digital libraries at the University of California San Francisco's Tobacco Control Archives; IFLA's Functional Requirements for Bibliographic Records; and designing the Texas email repository model…

  2. 30 January 2012 - Ecuadorian Ambassador Gallegos Chiriboga, Permanent Representative to the United Nations Office and other International Organisations at Geneva and San Francisco de Quito University Vice Chancellor C. Montùfar visiting CMS surface facilities and underground experimental area with CMS Collaboration L. Sulak and Collaboration Deputy Spokesperson T. Camporesi, throughout accompanied by Head of International Relations F. Pauss.

    CERN Multimedia

    Michael Hoch

    2012-01-01

    30 January 2012 - Ecuadorian Ambassador Gallegos Chiriboga, Permanent Representative to the United Nations Office and other International Organisations at Geneva and San Francisco de Quito University Vice Chancellor C. Montùfar visiting CMS surface facilities and underground experimental area with CMS Collaboration L. Sulak and Collaboration Deputy Spokesperson T. Camporesi, throughout accompanied by Head of International Relations F. Pauss.

  3. Stress-based aftershock forecasts made within 24h post mainshock: Expected north San Francisco Bay area seismicity changes after the 2014M=6.0 West Napa earthquake

    Science.gov (United States)

    Parsons, Thomas E.; Segou, Margaret; Sevilgen, Volkan; Milner, Kevin; Field, Edward; Toda, Shinji; Stein, Ross S.

    2014-01-01

    We calculate stress changes resulting from the M= 6.0 West Napa earthquake on north San Francisco Bay area faults. The earthquake ruptured within a series of long faults that pose significant hazard to the Bay area, and we are thus concerned with potential increases in the probability of a large earthquake through stress transfer. We conduct this exercise as a prospective test because the skill of stress-based aftershock forecasting methodology is inconclusive. We apply three methods: (1) generalized mapping of regional Coulomb stress change, (2) stress changes resolved on Uniform California Earthquake Rupture Forecast faults, and (3) a mapped rate/state aftershock forecast. All calculations were completed within 24 h after the main shock and were made without benefit of known aftershocks, which will be used to evaluative the prospective forecast. All methods suggest that we should expect heightened seismicity on parts of the southern Rodgers Creek, northern Hayward, and Green Valley faults.

  4. Contesting history and pursuing "other" knowledge: A study of hip-hop and non-formal education among Native American youth in San Francisco and black Portuguese youth in Lisbon

    Science.gov (United States)

    Tom, Miye Nadya

    2016-12-01

    This paper presents a broad-reaching effort to interrogate enduring colonial legacies as experienced by Native American youth in the United States of America and Black Portuguese youth of Cape Verdean origin in Portugal. As part of its methodological approach, it uses hip-hop - a cultural movement composed of four elements including rap music - to examine how youth from specific communities access knowledge which is denied to them in schools, give revolutionary voice to their realities, and broadcast perspectives on race, place and belonging. When knowledge is negated in learning institutions, non-formal education created by youth is a powerful force in re-affirming tradition and transformation. Hip-hop becomes a medium to create alternative educational projects addressing the needs of youth in San Francisco, USA, and Lisbon, Portugal, where this research was conducted.

  5. Analysis of Salinity Intrusion in the San Francisco Bay-Delta Using a GA-Optimized Neural Net, and Application of the Model to Prediction in the Elkhorn Slough Habitat

    Science.gov (United States)

    Thompson, D. E.; Rajkumar, T.

    2002-12-01

    The San Francisco Bay Delta is a large hydrodynamic complex that incorporates the Sacramento and San Joaquin Estuaries, the Suisan Marsh, and the San Francisco Bay proper. Competition exists for the use of this extensive water system both from the fisheries industry, the agricultural industry, and from the marine and estuarine animal species within the Delta. As tidal fluctuations occur, more saline water pushes upstream allowing fish to migrate beyond the Suisan Marsh for breeding and habitat occupation. However, the agriculture industry does not want extensive salinity intrusion to impact water quality for human and plant consumption. The balance is regulated by pumping stations located along the estuaries and reservoirs whereby flushing of fresh water keeps the saline intrusion at bay. The pumping schedule is driven by data collected at various locations within the Bay Delta and by numerical models that predict the salinity intrusion as part of a larger model of the system. The Interagency Ecological Program (IEP) for the San Francisco Bay / Sacramento-San Joaquin Estuary collects, monitors, and archives the data, and the Department of Water Resources provides a numerical model simulation (DSM2) from which predictions are made that drive the pumping schedule. A problem with DSM2 is that the numerical simulation takes roughly 16 hours to complete a prediction. We have created a neural net, optimized with a genetic algorithm, that takes as input the archived data from multiple gauging stations and predicts stage, salinity, and flow at the Carquinez Straits (at the downstream end of the Suisan Marsh). This model seems to be robust in its predictions and operates much faster than the current numerical DSM2 model. Because the Bay-Delta is strongly tidally driven, we used both Principal Component Analysis and Fast Fourier Transforms to discover dominant features within the IEP data. We then filtered out the dominant tidal forcing to discover non-primary tidal effects

  6. Symposium DD: Low-Dimensional Materials-Synthesis, Assembly, Property Scaling and Modeling. Held in San Francisco, CA on April 9-13, 2007

    Science.gov (United States)

    2008-06-01

    Ciencia e Ingenieria de los Materiales , Universidad de Costa Rica, San Jose, Costa Rica. We have developed a new unifying tight-binding theory that...Fisico Matem6ticas, Universidad Aut6noma de Nuevo Le6n, San Nicolas de los Garza, Nuevo LeAfA3n, Mexico; 2Chemical Engineering Department and Texas...ORNL), Oak Ridge, Tennessee; 2Departamento de Ciencia de los Materiales e IM y QI, Universidad de Cadiz, Puerto Real, Cadiz, Spain; 3Departamento de

  7. San Francisco Bay Area CHARG: Coastal Hazards Adaptation Resiliency Group, a Multi-Jurisdictional Collaboration to Develop Innovative Regional Solutions to Address Sea Level Rise and Improve Shoreline Resiliency

    Science.gov (United States)

    Saleh, R.

    2017-12-01

    For a challenge as complex and far-reaching as sea level rise and improving shoreline resiliency, strong partnerships between scientists, elected officials, decision-makers, and the general public are the only way that effective solutions can be developed. The San Francisco Bay, like many similar sheltered water coastal environments (for example, Galveston Bay, Tampa Bay, or Venetian Lagoon) offers a unique opportunity for multiple jurisdictions to collaborate to address sea level rise on a regional basis. For the San Francisco Bay, significant scientific progress has been made in building a real-time simulation model for riverine and Bay hydrodynamics. Other major scientific initiatives, such as morphology mapping, shoreline mapping, and a sediment budget are also underway. In 2014, leaders from the Bay Area science, engineering, planning, policy, elected, and regulatory communities representing jurisdictions around the Bay joined together to address sea level rise. The group includes people from local, regional, state, and federal agencies and organizations. Together, CHARG (Coastal Hazards Adaptation Resiliency Group) established a collective vision and approach to implementing regional solutions. Decision-makers within many Bay Area jurisdictions are motivated to show demonstrable progress toward addressing sea level rise. However, the cost to implement shoreline resiliency solutions will be very large, and must be founded on strong science.CHARG is now tackling several key technical challenges. One is to develop science-based guidelines for local jurisdictions to determine when a project is local, sub-regional, or regional. Concurrently, several organizations are planning or implementing pilot shoreline resiliency projects and other programs. Many creative regional solutions are possible in a sheltered water environment that simply would not be feasible along the open coast. By definition, these solutions cannot be undertaken by one entity alone. Large

  8. Petrografía, geoquímica y geocronología de rocas metamórficas aflorantes en San Francisco Putumayo y la vía Palermo-San Luis asociadas a los complejos La Cocha - Río Téllez y Aleluya

    OpenAIRE

    Zapata García, Gilberto; Rodríguez García, Gabriel; Mejía, María Isabel Arango

    2017-01-01

    El Complejo Migmatítico La Cocha - Río Téllez comprende un conjunto de rocas metamórficas: migmatitas, esquistos, neises y anfibolitas, en contacto fallado con la Cuarzomonzonita de Sombrerillo y rocas sedimentarias cretácicas. Se asume como la edad del metamorfismo del Complejo Migmatítico La Cocha-Río Téllez la edad U-Pb en circones de 163.6±4.7 Ma, obtenida en un esquisto cuarzo feldespático que aflora en el municipio de San Francisco-Putumayo, las edades de194.4±2.0 Ma, 218.8 Ma y 229.8 M...

  9. Delta smelt habitat in the San Francisco Estuary: A reply to Manly, Fullerton, Hendrix, and Burnham’s “Comments on Feyrer et al. Modeling the effects of future outflow on the abiotic habitat of an imperiled estuarine fish"

    Science.gov (United States)

    Feyrer, Frederick V.; Newman, Ken B.; Nobriga, Matthew; Sommer, Ted

    2016-01-01

    Manly et al. (2015) commented on the approach we (Feyrer et al. 2011) used to calculate an index of the abiotic habitat of delta smelt Hypomesus transpacificus. The delta smelt is an annual fish species endemic to the San Francisco Estuary (SFE) in California, USA. Conserving the delta smelt population while providing reliability to California’s water supply with water diverted from the SFE ecosystem is a major management and policy issue. Feyrer et al. (2011) evaluated historic and projected future abiotic habitat conditions for delta smelt. Manly et al. (2015) specifically commented regarding the following: (1) use of an independent abundance estimate, (2) spatial bias in the habitat index, and (3) application of the habitat index to future climate change projections. Here, we provide our reply to these three topics. While we agree that some of the concepts raised by Manly et al. (2015) have the potential to improve habitat assessments and their application to climate change scenarios as knowledge is gained, we note that the Feyrer et al. (2011) delta smelt habitat index is essentially identical to one reconstructed using Manly et al.’s (2015) preferred approach (their model 8), as shown here in Fig. 1.

  10. Post-9/11 cancer incidence in World Trade Center-exposed New York City firefighters as compared to a pooled cohort of firefighters from San Francisco, Chicago and Philadelphia (9/11/2001-2009)

    Science.gov (United States)

    Moir, William; Zeig-Owens, Rachel; Daniels, Robert D; Hall, Charles B; Webber, Mayris P; Jaber, Nadia; Yiin, James H; Schwartz, Theresa; Liu, Xiaoxue; Vossbrinck, Madeline; Kelly, Kerry; Prezant, David J

    2016-01-01

    Background We previously reported a modest excess of cancer cases in World Trade Center (WTC) exposed firefighters as compared with the general population. This study aimed to separate the potential carcinogenic effects of firefighting and WTC-exposure by using a cohort of non-WTC-exposed firefighters as the referent group. Methods Relative rates (RRs) for all cancers combined and individual cancer subtypes from 9/11/2001-12/31/2009 were modelled using Poisson regression comparing 11,457 WTC-exposed firefighters to 8,220 non-WTC-exposed firefighters from San Francisco, Chicago, and Philadelphia. Results Compared with non-WTC-exposed firefighters, there was no difference in the RR of all cancers combined for WTC-exposed firefighters (RR=0.96, 95% CI: 0.83–1.12). Thyroid cancer was significantly elevated (RR=3.82, 95% CI: 1.07–20.81) over the entire study; this was attenuated (RR=3.43, 95% CI: 0.94–18.94) and non-significant in a secondary analysis controlling for possible surveillance bias. Prostate cancer was elevated during the latter half (1/1/2005-12/31/2009; RR=1.38, 95% CI: 1.01–1.88). Conclusions Further follow-up is needed with this referent population to assess the relationship between WTC-exposure and cancers with longer latency periods. PMID:27582474

  11. Participant experiences and facilitators and barriers to pill use among men who have sex with men in the iPrEx pre-exposure prophylaxis trial in San Francisco.

    Science.gov (United States)

    Gilmore, Hailey J; Liu, Albert; Koester, Kimberly Ann; Amico, K Rivet; McMahan, Vanessa; Goicochea, Pedro; Vargas, Lorena; Lubensky, David; Buchbinder, Susan; Grant, Robert

    2013-10-01

    In 2010, the iPrEx study demonstrated efficacy of daily emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) pre-exposure prophylaxis (PrEP) in reducing HIV acquisition among men who have sex with men. Adherence to study product was critical for PrEP efficacy, and varied considerably, with FTC/TDF detection rates highest in the United States. We conducted a qualitative study to gain insights into the experiences of iPrEx participants in San Francisco (SF) where there was high confirmed adherence, to understand individual and contextual factors influencing study product use in this community. In 2009 and 2011, we conducted focus groups and in-depth interviews in 36 and 16 SF iPrEx participants, respectively. Qualitative analyses indicate that participants joined the study out of altruism. They had a clear understanding of study product use, and pill taking was facilitated by establishing or building on an existing routine. Participants valued healthcare provided by the study and relationships with staff, whom they perceived as nonjudgmental, and found client-centered counseling to be an important part of the PrEP package. This facilitated pill taking and accurate reporting of missed doses. Adherence barriers included changes in routine, side effects/intercurrent illnesses, and stress. Future PrEP adherence interventions should leverage existing routines and establish client-centered relationships/ environments to support pill taking and promote accurate reporting.

  12. Near-Field Receiving Water Monitoring of Trace Metals and a Benthic Community Near the Palo Alto Regional Water Quality Control Plant in South San Francisco Bay, California: 2008

    Science.gov (United States)

    Cain, Daniel J.; Thompson, Janet K.; Dyke, Jessica; Parcheso, Francis; Luoma, Samuel N.; Hornberger, Michelle I.

    2009-01-01

    Results reported herein include trace element concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica (Cohen and Carlton, 1995)), clam reproductive activity, and benthic macroinvertebrate community structure for a mudflat one kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in South San Francisco Bay. This report includes data collected for the period January 2008 to December 2008 and extends a critical long-term biogeochemical record dating back to 1974. These data serve as the basis for the City of Palo Alto's Near-Field Receiving Water Monitoring Program, initiated in 1994. In 2008, metal concentrations in both sediments and clam tissue were among the lowest concentrations on record and consistent with results observed since 1991. Following significant reductions in the late 1980's, silver (Ag) and copper (Cu) concentrations appeared to have stabilized. Annual mean concentrations have fluctuated modestly (2-4 fold) in a nondirectional manner. Data for other metals, including chromium, mercury, nickel, selenium, vanadium, and zinc, have been collected since 1994. Over this period, concentrations of these elements, which more likely reflect regional inputs and systemwide processes, have remained relatively constant, aside from typical seasonal variation that is common to all elements. Within years, concentrations generally reach maximum in winter months (January-March) and decline to annual minima in spring through fall. Mercury (Hg) in sediments spiked to the highest observed level in January 2008. However, sedimentary concentrations for the rest of the year and concentrations of Hg in M. petalum for the entire year were consistent with data from previous years. Average selenium (Se) concentrations in sediment were the highest on record, but there is no evidence, yet, to suggest a temporal trend of increasing sedimentary Se. Selenium in M. petalum was not elevated relative to

  13. Evaluation of Caspian tern (Hydroprogne caspia) and snowy plover (Charadrius alexandrinus nivosus) nesting on modified islands at the Don Edwards San Francisco Bay National Wildlife Refuge, California—2016 Annual Report

    Science.gov (United States)

    Hartman, C. Alex; Ackerman, Joshua T.; Herzog, Mark P.; Strong, Cheryl; Trachtenbarg, David; Shore, Crystal A.

    2017-05-08

    Executive SummaryIn order to address the 2008/10 and Supplemental 2014 NOAA Fisheries Biological Opinion for operation of the Federal Columbia River Power System, the U.S. Army Corps of Engineers (USACE) and the Bureau of Reclamation (Reclamation) developed and have begun implementation of Caspian tern (Hydroprogne caspia) management plans. This implementation includes redistribution of the Caspian terns in the Columbia River estuary and the mid-Columbia River region to reduce predation on salmonids listed under the Endangered Species Act. Key elements of the plans include (1) reducing nesting habitat for Caspian terns in the Columbia River estuary and the mid-Columbia River region, and (2) creating or modifying nesting habitat at alternative sites within the Caspian tern breeding range. USACE and Reclamation developed Caspian tern nesting habitat at the U.S. Fish and Wildlife Service Don Edwards San Francisco Bay National Wildlife Refuge (DENWR), California, prior to the 2015 nesting season. Furthermore, to reduce or eliminate potential conflicts between nesting Caspian terns and threatened western snowy plovers (Charadrius alexandrinus nivosus), nesting habitat for snowy plovers also was developed. Seven recently constructed islands within two managed ponds (Ponds A16 and SF2) of DENWR were modified to provide habitat attractive to nesting Caspian terns (5 islands) and snowy plovers (2 islands). These 7 islands were a subset of 46 islands recently constructed in Ponds A16 and SF2 to provide waterbird nesting habitat as part of the South Bay Salt Pond (SBSP) Restoration Project.We used social attraction methods (decoys and electronic call systems) to attract Caspian terns and snowy plovers to these seven modified islands, and conducted surveys between March and September of 2015 and 2016 to evaluate nest numbers, nest density, and productivity. Results from the 2015 nesting season, the first year of the study, indicated that island modifications and social

  14. The 1911 M ~6.6 Calaveras earthquake: Source parameters and the role of static, viscoelastic, and dynamic coulomb stress changes imparted by the 1906 San Francisco earthquake

    Science.gov (United States)

    Doser, D.I.; Olsen, K.B.; Pollitz, F.F.; Stein, R.S.; Toda, S.

    2009-01-01

    The occurrence of a right-lateral strike-slip earthquake in 1911 is inconsistent with the calculated 0.2-2.5 bar static stress decrease imparted by the 1906 rupture at that location on the Calaveras fault, and 5 yr of calculated post-1906 viscoelastic rebound does little to reload the fault. We have used all available first-motion, body-wave, and surface-wave data to explore possible focal mechanisms for the 1911 earthquake. We find that the event was most likely a right-lateral strikeslip event on the Calaveras fault, larger than, but otherwise resembling, the 1984 Mw 6.1 Morgan Hill earthquake in roughly the same location. Unfortunately, we could recover no unambiguous surface fault offset or geodetic strain data to corroborate the seismic analysis despite an exhaustive archival search. We calculated the static and dynamic Coulomb stress changes for three 1906 source models to understand stress transfer to the 1911 site. In contrast to the static stress shadow, the peak dynamic Coulomb stress imparted by the 1906 rupture promoted failure at the site of the 1911 earthquake by 1.4-5.8 bar. Perhaps because the sample is small and the aftershocks are poorly located, we find no correlation of 1906 aftershock frequency or magnitude with the peak dynamic stress, although all aftershocks sustained a calculated dynamic stress of ???3 bar. Just 20 km to the south of the 1911 epicenter, we find that surface creep of the Calaveras fault at Hollister paused for ~17 yr after 1906, about the expected delay for the calculated static stress drop imparted by the 1906 earthquake when San Andreas fault postseismic creep and viscoelastic relaxation are included. Thus, the 1911 earthquake may have been promoted by the transient dynamic stresses, while Calaveras fault creep 20 km to the south appears to have been inhibited by the static stress changes.

  15. CAPITALISMO, CUERPOS Y ENERGÍAS EN CONTEXTOS DE EXPULSIÓN. EXPERIENCIAS DE TRABAJO EN LAS MUJERES RECUPERADORAS DE RESIDUOS DE CÓRDOBA Y SAN FRANCISCO

    Directory of Open Access Journals (Sweden)

    Gabriela Vergara

    2011-12-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 Normal 0 21 false false false ES-AR X-NONE X-NONE st1\\:*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} El presente artículo analiza las formas que adquiere expropiación de energías corporales en la recuperación de residuos, particularmente cuando ésta es realizada por mujeres. Partiendo desde la Sociología de los cuerpos, se  describen tres escenarios del trabajo, con el objeto de mostrar diferencias y similitudes entre ellos: en las calles buscando residuos, en sus hogares realizando las tareas domésticas y, finalmente en estos últimos, clasificando, cuidando y acopiando residuos. Desde este análisis es posible comprender que  el capitalismo en la periferia sigue recreando en distintos lugares el mismo mecanismo de expropiación de fuerza de trabajo humana. A pesar de esto,  existen otras lógicas por las cuales los sujetos no son sólo meras mercancías.

  16. EL SISTEMA VESTIBULAR EN EL DESARROLLO DE LA PSICOMOTRICIDAD GRUESA EN LOS NIÑOS-AS DE 4-5 AÑOS DEL INSTITUTO SAN FRANCISCO DE ASÍS EN LA PROVINCIA DE CHIMBORAZO, CANTON RIOBAMBA, PARROQUIA JUAN DE VELASCO EN EL AÑO LECTIVO 2011-2012

    OpenAIRE

    Paguay Franco, Rosana Isabel

    2016-01-01

    El presente trabajo de investigación va orientado a analizar el sistema vestibular y el desarrollo de la psicomotricidad gruesa en niños-as de 4-5 años del Instituto San Francisco de Asís; se realizó con el objetivo de concienciar a docentes y padres de familia acerca de la importancia del sistema vestibular en el proceso de aprendizaje de toda persona. Es novedosa la contribución de la psicomotricidad gruesa pues tiene como principal propósito el desarrollar y recuperar el propio cuerpo. Se ...

  17. Incidencia del desarrollo psicomotriz en la expresión grafo-plástica en los niños de tres, cuatro y cinco años, de la Unidad Educativa San Francisco de Sales, de la ciudad de Cuenca, en el periodo 2014 - 2015

    OpenAIRE

    González Nole, Grey Elizabeth; Quichimbo Peralta, María Rocío

    2015-01-01

    El documento consiste en analizar la incidencia del desarrollo psicomotriz en los niños de la Unidad Educativa "San Francisco de Sales", fundamentado en la aplicación de técnicas grafo-plásticas para su proceso evolutivo y la adquisición de habilidades motoras y cognitivas en los primeros años de vida, para mejorar las actividades de aprendizaje en los niños de tres a cincos años de edad. The document consists on analyzing the incidence of the psychomotor development in children of the Uni...

  18. Rendimento da pupunheira em função da densidade de plantio, diâmetro de corte e manejo dos perfilhos no Vale do São Francisco Effect of density, cut-off diameter classes and shoot number on production and yield of irrigated plant peach palm at San Francisco River Valley

    Directory of Open Access Journals (Sweden)

    José Egidio Flori

    2004-02-01

    in the split-plot with four replicates. The whole plots were plant spacing S¹ - 2 x 1 m and S² - 2 x 2 m and the subplots were 12 m² (with factorial arrangement of two diameters and two shoot number. The harvesting was done from 16 to 69 months after planting with three months interval. The cut-off diameter class affected significantly the production. The yields of heart of palm at diameter classes 10 cm and 12 cm were 494 and 484 kg ha-1 year-1 and, respectively. The average weight of heart of palm for the cut-off diameters 10 cm and 12 cm were 149 g and 178 g and yield of heart of palm were 545 and 434 kg ha-1 year-1, respectively. Planting space affect all the parameters evaluated, except the average plant height. The results allow to point out, as information for the irrigated areas of the San Francisco Valley, the cultivation of peach palm spaced 2 x 1 m and cut-off diameter of de stem from 10 to 12 cm about 30 cm up the grownd.

  19. Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California: 2011

    Science.gov (United States)

    Dyke, Jessica; Thompson, Janet K.; Cain, Daniel J.; Kleckner, Amy E.; Parcheso, Francis; Luoma, Samuel N.; Hornberger, Michelle I.

    2012-01-01

    Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in South San Francisco Bay, Calif. This report includes the data collected by U.S. Geological Survey (USGS) scientists for the period January 2011 to December 2011. These data serve as the basis for the City of Palo Alto's Near-Field Receiving Water Monitoring Program, initiated in 1994. Following significant reductions in the late 1980s, silver (Ag) and copper (Cu) concentrations in sediment and M. petalum appear to have stabilized. Data for other metals, including chromium, mercury, nickel, selenium, and zinc, have been collected since 1994. Over this period, concentrations of these elements have remained relatively constant, aside from seasonal variation that is common to all elements. In 2011, concentrations of Ag and Cu in M. petalum varied seasonally in response to a combination of site-specific metal exposures and annual growth and reproduction, as reported previously. Seasonal patterns for other elements, including Cr, Hg, Ni, Se, and Zn, were generally similar in timing and magnitude as those for Ag and Cu. In 2011, metal concentrations in both sediments and clam tissue were among the lowest concentrations on record. This record suggests that regional-scale factors now largely control sedimentary and bioavailable concentrations of Ag and Cu, as well as other elements of regulatory interest, at the Palo Alto site. Analyses of the benthic community structure of a mudflat in South San Francisco Bay over a 38-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinel clam, M. petalum, from the same area. Analysis of the M. petalum community

  20. Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in South San Francisco Bay, California: 2013

    Science.gov (United States)

    Dyke, Jessica; Cain, Daniel J.; Thompson, Janet K.; Kleckner, Amy E.; Parcheso, Francis; Hornberger, Michelle I.; Luoma, Samuel N.

    2014-01-01

    Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in South San Francisco Bay, Calif. This report includes the data collected by U.S. Geological Survey (USGS) scientists for the period January 2013 to December 2013. These data serve as the basis for the City of Palo Alto’s Near-Field Receiving Water Monitoring Program, initiated in 1994. Following significant reductions in the late 1980s, silver (Ag) and copper (Cu) concentrations in sediment and M. petalum appear to have stabilized. Data for other metals, including chromium (Cr), mercury (Hg), nickel (Ni), selenium (Se), and zinc (Zn), have been collected since 1994. Over this period, concentrations of these elements have remained relatively constant, aside from seasonal variation that is common to all elements. In 2013, concentrations of Ag and Cu in M. petalum varied seasonally in response to a combination of site-specific metal exposures and annual growth and reproduction, as reported previously. Seasonal patterns for other elements, including Cr, Ni, Zn, Hg, and Se, were generally similar in timing and magnitude as those for Ag and Cu. In M. petalum, all observed elements showed annual maxima in January–February and minima in April, except for Zn, which was lowest in December. In sediments, annual maxima also occurred in January–February, and minima were measured in June and September. In 2013, metal concentrations in both sediments and clam tissue were among the lowest concentrations on record. This record suggests that regional-scale factors now largely control sedimentary and bioavailable concentrations of Ag and Cu, as well as other elements of regulatory interest, at the Palo Alto site. Analyses of the benthic community structure of a

  1. Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California, 2012

    Science.gov (United States)

    Dyke, Jessica; Thompson, Janet K.; Cain, Daniel J.; Kleckner, Amy E.; Parcheso, Francis; Luoma, Samuel N.; Hornberger, Michelle I.

    2013-01-01

    Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in South San Francisco Bay, Calif. This report includes the data collected by U.S. Geological Survey (USGS) scientists for the period January to December 2012. These data serve as the basis for the City of Palo Alto’s Near-Field Receiving Water Monitoring Program, initiated in 1994. Following significant reductions in the late 1980s, silver (Ag) and copper (Cu) concentrations in sediment and in M. petalum appear to have stabilized. Data for other metals, including chromium (Cr), mercury (Hg), nickel (Ni), selenium (Se), and zinc (Zn), have been collected since 1994. Over this period, concentrations of these elements have remained relatively constant, aside from seasonal variation that is common to all elements. In 2012, concentrations of Ag and Cu in M. petalum varied seasonally in response to a combination of site-specific metal exposures and annual growth and reproduction, as reported for previous time periods. Seasonal patterns for other elements, including Cr, Ni, Zn, Hg, and Se were generally similar in timing and magnitude as those for Ag and Cu. In 2012, metal concentrations in both sediments and clam tissue were among the lowest concentrations on record. This record suggests that regional-scale factors now largely control sedimentary and bioavailable concentrations of Ag and Cu, as well as other elements of regulatory interest, at the Palo Alto site. Analyses of the benthic community structure of a mudflat in South San Francisco Bay over a 39-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinel clam, M. petalum, from the same area

  2. Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California; 2016

    Science.gov (United States)

    Cain, Daniel J.; Thompson, Janet K.; Parchaso, Francis; Pearson, Sarah; Stewart, Robin; Turner, Mathew; Barasch, David; Luoma, Samuel N.

    2017-10-30

    Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in south San Francisco Bay, Calif. This report includes the data collected by U.S. Geological Survey (USGS) scientists for the period January 2014 to December 2016. These append to long-term datasets extending back to 1974. A major focus of the report is an integrated description of the 2016 data within the context of the longer, multi-decadal dataset. This dataset supports the City of Palo Alto’s Near-Field Receiving Water Monitoring Program, initiated in 1994.Significant reductions in silver and copper concentrations in sediment and M. petalum occurred at the site in the 1980s following the implementation by PARWQCP of advanced wastewater treatment and source control measures. Since the 1990s, concentrations of these elements appear to have stabilized at concentrations somewhat above (silver) or near (copper) regional background concentrations Data for other metals, including chromium (Cr), mercury (Hg), nickel (Ni), selenium (Se), and zinc (Zn), have been collected since 1994. Over this period, concentrations of these elements have remained relatively constant, aside from seasonal variation that is common to all elements. In 2016, concentrations of silver and copper in M. petalum varied seasonally in response to a combination of site-specific metal exposures and annual growth and reproduction, as reported previously. Seasonal patterns for other elements, including Cr, Ni, Zn, Hg, and Se, were generally similar in timing and magnitude as those for Ag and Cu. This record suggests that legacy contamination and regional-scale factors now largely control sedimentary and bioavailable concentrations of silver and copper, as well as other elements of

  3. Hyatt Regency - San Francisc