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Sample records for san antonio bay

  1. San Antonio Bay 1986-1989

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The effect of salinity on utilization of shallow-water nursery habitats by aquatic fauna was assessed in San Antonio Bay, Texas. Overall, 272 samples were collected...

  2. Discharge between San Antonio Bay and Aransas Bay, southern Gulf Coast, Texas, May-September 1999

    Science.gov (United States)

    East, Jeffery W.

    2001-01-01

    Along the Gulf Coast of Texas, many estuaries and bays are important habitat and nurseries for aquatic life. San Antonio Bay and Aransas Bay, located about 50 and 30 miles northeast, respectively, of Corpus Christi, are two important estuarine nurseries on the southern Gulf Coast of Texas (fig. 1). According to the Texas Parks and Wildlife Department, “Almost 80 percent of the seagrasses [along the Texas Gulf Coast] are located in the Laguna Madre, an estuary that begins just south of Corpus Christi Bay and runs southward 140 miles to South Padre Island. Most of the remaining seagrasses, about 45,000 acres, are located in the heavily traveled San Antonio, Aransas and Corpus Christi Bay areas” (Shook, 2000).Population growth has led to greater demands on water supplies in Texas. The Texas Water Development Board, the Texas Parks and Wildlife Department, and the Texas Natural Resource Conservation Commission have the cooperative task of determining inflows required to maintain the ecological health of the State’s streams, rivers, bays, and estuaries. To determine these inflow requirements, the three agencies collect data and conduct studies on the need for instream flows and freshwater/ saline water inflows to Texas estuaries.To assist in the determination of freshwater inflow requirements, the U.S. Geological Survey (USGS), in cooperation with the Texas Water Development Board, conducted a hydrographic survey of discharge (flow) between San Antonio Bay and Aransas Bay during the period May–September 1999. Automated instrumentation and acoustic technology were used to maximize the amount and quality of data that were collected, while minimizing personnel requirements. This report documents the discharge measured at two sites between the bays during May–September 1999 and describes the influences of meteorologic (wind and tidal) and hydrologic (freshwater inflow) conditions on discharge between the two bays. The movement of water between the bays is

  3. Occurrence of the haemocyte parasite Bonamia sp. in flat oysters Ostrea puelchana farmed in San Antonio Bay (Argentina).

    Science.gov (United States)

    Kroeck, Marina A; Montes, Jaime

    2005-02-28

    Culture of native flat oysters Ostrea puelchana d'Orbigny in San Antonio Bay (San Matías Gulf, Argentina) began in 1995. After elevated mortality (33%) occurred in September 1996, 18 mo after immersion, histopathological analysis and evaluation of parasitic prevalence was carried out. In October 1997, after 31 mo of cultivation, cumulative mortality was 80%, and in December of the same year, when individuals reached marketable size, mortality was 95% and culture was discontinued. The present study describes the haemocytic parasitism that affected O. puelchana, and suggests that a Bonamia sp. was the etiological agent. This parasite should be considered as a different species from Bonamia sp. detected in Australia and New Zealand until more studies are made to determine the correct taxonomy. This work constitutes the first record of this haemocyte parasite in flat oysters from the Argentinean coast.

  4. San Antonio-Espiritu Santo Bay, Texas Four band, 1meter resolution, UltraCam orthoimage

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Office for Coastal Management purchased digital Vexcel Ultracam imagery and digital elevation models of the Texas coastline at Espiritu-Santo Bay in 2007....

  5. Biological and associated water-quality data for lower Olmos Creek and upper San Antonio River, San Antonio, Texas, March-October 1990

    Science.gov (United States)

    Taylor, R. Lynn

    1995-01-01

    Biological and associated water-quality data were collected from lower Olmos Creek and upper San Antonio River in San Antonio, Texas, during March-October 1990, the second year of a multiyear data-collection program. The data will be used to document water-quality conditions prior to implementation of a proposal to reuse treated wastewater to irrigate city properties in Olmos Basin and Brackenridge Parks and to augment flows in the Olmos Creek/San Antonio River system.

  6. 77 FR 36041 - San Antonio Central Railroad, L.L.C.-Lease Exemption-Port Authority of San Antonio

    Science.gov (United States)

    2012-06-15

    ... control of SAC upon SAC becoming a Class III rail carrier. As a result of this transaction, SAC will provide common carrier rail service over the rail lines owned by the Port in the East Kelly Railport (the... and operate approximately four miles of rail line owned by the Port Authority of San Antonio (the Port...

  7. City of San Antonio, Texas Better Buildings Program

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Liza C. [City of San Antonio, TX (United States); Hammer, Mary C. [City of San Antonio, TX (United States)

    2014-06-30

    The San Antonio Better Buildings Program is a unified single-point-of-service energy efficiency delivery mechanism targeting residential, commercial, institutional, industrial and public buildings. This comprehensive and replicable energy efficiency program is designed to be an effective demand side management initiative to provide a seamless process for program participants to have turn-key access to expert analysis, support and incentives to improve the performance of their in-place energy using systems, while reducing electrical energy use and demand.

  8. Feasibility study on rehabilitation of ICE San Antonio Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    Costa Rica takes a power generation system using hydro power generation as the main source, and possesses medium-capacity gas turbines to supplement needs in the dry season and the peak load. However, a problem has come up that, in addition to the cost rise in gas turbine fuel, the power generation efficiency has been aggravating due to aged deterioration of the generators being used. In association therewith, the problem is now a factor to increase CO2 emission, which is a worldwide problem. Keeping in mind to link it to the clean development mechanism (CDM), the present project is, taking up the SAN ANTONIO power plant as the investigation object, intended to perform a comprehensive discussion on the CO2 emission reducing effect, profitability, and proliferation effect, by executing the conceptual plant design. The up-grading plan for thermal power generation systems in Costa Rica consists of replacement of the gas turbines, handling of phase modifiers, and achievement of the combined cycle. The plan agrees with the present feasibility study intended of CO2 emission reduction, consisting of the modification plan of the SAN ANTONIO power plant, that is the plan to replace the over-aged gas turbines at the power plant. Its necessity has been identified. It was disclosed that the project has the effects of reducing CO2 of 82,000 tons annually, and the investment can be recovered in nine years. (NEDO)

  9. United States Air Force Personalized Medicine and Advanced Diagnostics Program Panel: Representative Research at the San Antonio Military Medical Center

    Science.gov (United States)

    2016-05-20

    health system. dedicated to excellence in global care PROCESSING OF PROFESSIONAL MEDICAL RESEARCH PUBLICATIONS/PRESENTATIONS INSTRUCTIONS 1. The...present this research at the University of Texas at San Antonio/SAMHS & Universities Research Forum, SURF 2016 in San Antonio, TX, on 20 May 2016. The...at San Antonio/SAMHS & Universities Research Forum, SURF 2016 in San Antonio, TX, on 20 May 2016. 3. LAWS AND REGULATIONS: DoD 5500.07-R, Joint

  10. 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.,

  11. Implementation of an Online Climate Science Course at San Antonio College

    Science.gov (United States)

    Reyes, R.; Strybos, J.

    2016-12-01

    San Antonio College (SAC) plans to incorporate an online climate science class into the curriculum with a focus on local weather conditions and data. SAC is part of a network of five community colleges based around San Antonio, Texas, has over 20,000 students enrolled, and its student population reflects the diversity in ethnicity, age and gender of the San Antonio community. The college understands the importance of educating San Antonio residents on climate science and its complexities. San Antonio residents are familiar with weather changes and extreme conditions. The region has experienced an extreme drought, including water rationing in the city. Then, this year's El Niño intensified expected annual rainfalls and flash floods. The proposed climate science course will uniquely prepare students to understand weather data and the evidence of climate change impacting San Antonio at a local level. This paper will discuss the importance and challenges of introducing the new climate science course into the curriculum, and the desired class format that will increase the course's success. Two of the most significant challenges are informing students about the value of this class and identifying the best teaching format. Additionally, measuring and monitoring enrollment will be essential to determine the course performance and success. At the same time, Alamo Colleges is modifying the process of teaching online classes and is officially working to establish an online college. Around 23% of students enrolled in SAC offered courses are currently enrolled in online courses only, representing an opportunity to incorporate the climate science class as an online course. Since the proposed course will be using electronic textbooks and online applications to access hyperlocal weather data, the class is uniquely suited for online students.

  12. 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.

  13. 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...

  14. An Assessment of the Effectiveness of Remedial Reading Courses at San Antonio College.

    Science.gov (United States)

    Florio, Charles Bernard

    This study investigates the effectiveness of remedial reading courses for nontraditional students in San Antonio College, a large, urban, and public community college in Texas. The subjects were students who enrolled the fall semester of 1972 and persisted through the fall semester of 1973. The remedial reading courses were described in terms of…

  15. Bridging the Scholar-Practitioner Gap: The San Antonio Export Leaders Program

    Science.gov (United States)

    Jackson, Sara C.

    2013-01-01

    Bridging the gap between theory and practice enables trade service providers to effectively reach the small business community interested in entering foreign markets. This paper describes how the award-winning San Antonio Export Leaders program is a model for applying theoretical concepts to the practice of international business.

  16. 77 FR 38078 - U.S. Nominations to the World Heritage List: San Antonio Franciscan Missions

    Science.gov (United States)

    2012-06-26

    ... ownership rights in U.S. World Heritage Sites, which continue to be subject only to U.S. law. Inclusion in... group should be considered as an extension to the Mexican missions of the Sierra Gorda already on the... experts in the topic in San Antonio, including Mexican World Heritage officials, concluded that the...

  17. 77 FR 35376 - San Antonio Water System; Notice of Petition for Declaratory Order and Soliciting Comments...

    Science.gov (United States)

    2012-06-13

    ... in large diameter water pipelines. The water flow in the CRP pipeline at Naco is reduced from a 36... Water System; Notice of Petition for Declaratory Order and Soliciting Comments, Protests, and/or Motions...-000. c. Date Filed: May 29, 2012. d. Applicant: San Antonio Water System (SAWS). e. Name of Project...

  18. 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.

  19. 76 FR 1386 - Safety Zone; Centennial of Naval Aviation Kickoff, San Diego Bay, San Diego, CA

    Science.gov (United States)

    2011-01-10

    ...-AA00 Safety Zone; Centennial of Naval Aviation Kickoff, San Diego Bay, San Diego, CA AGENCY: Coast... zone on the navigable waters of San Diego Bay in San Diego, CA in support of the Centennial of Naval... February 12, 2010, the Centennial of Naval Aviation Kickoff will take place in San Diego Bay. In support of...

  20. 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...

  1. Biological and associated water-quality data for lower Olmos Creek and upper San Antonio River, San Antonio, Texas, April - September 1989

    Science.gov (United States)

    Taylor, R. Lynn; Ferreira, Rodger F.

    1995-01-01

    Biological and associated water-quality data were collected from lower Olmos Creek and upper San Antonio River in San Antonio, Texas, during April-September 1989. Benthic macroinvertebrate, periphyton, and phytoplankton communities were sampled at three sites along the Olmos Creek/San Antonio River system. Total mean densities of benthic macroinvertebrates for the three sites ranged from 670 to 10,000 organisms per square meter. The most abundant macroinvertebrates were the class Insecta (insects). Total densities of periphyton ranged from 2,900 to 110,000 cells per square millimeter. Cyanophyta (blue-green algae) and Bacillariophyta (diatoms) were the predominant periphyton organisms. Total densities of phyto- plankton ranged from 5,000 to 47,000 cells per square milliliter. Blue-green algae accounted for more than one- half of the phytoplankton in each sample. Hardness ranged from 160 to 250 milligrams per liter as calcium carbonate, and alkalinity ranged from 130 to 220 milligrams per liter as calcium carbonate. The largest dissolved nitrite concentration was 0.038 milligram per liter. The largest total phosphorus concentration was 0.150 milligram per liter, over one-half of which was dissolved orthophosphate. Total aluminum and total iron were the only trace elements in water to exceed the reporting threshold by large concen- trations. Total aluminum concentrations ranged from 70 to 280 micrograms per liter, and total iron concentrations ranged from 70 to 340 micrograms per liter. Lead was the most prominent trace element in bottom-material samples, with concentrations ranging from 30 to 230 micrograms per gram.

  2. Financial Reporting for the Other Defense Organizations - General Funds at the Defence Finance and Accounting Service San Antonio

    National Research Council Canada - National Science Library

    2002-01-01

    ...) for inclusion in the FY 2001 Other Defense Organizations Financial Statements. Specifically, we looked at the abnormal balances reported in trial balances prepared by the Defense Finance and Accounting Service San Antonio...

  3. LaRC Modeling of Ozone Formation in San Antonio, Texas

    Science.gov (United States)

    Guo, F.; Griffin, R. J.; Bui, A.; Schulze, B.; Wallace, H. W., IV; Flynn, J. H., III; Erickson, M.; Kotsakis, A.; Alvarez, S. L.; Usenko, S.; Sheesley, R. J.; Yoon, S.

    2017-12-01

    Ozone (O3) is one of the most important trace species within the troposphere and results from photochemistry involving emissions from a complex array of sources. Ground-level O3 is detrimental to ecosystems and causes a variety of human health problems including respiratory irritation, asthma and reduction in lung capacity. However, the O3 Design Value in San Antonio, Texas, was in violation of the federal threshold set by the EPA (70 ppb, 8-hr max) based on the average for the most recent three-year period (2014-2016). To understand the sources of high O3 concentrations in this nonattainment area, we assembled and deployed a mobile air quality laboratory and operated it in two locations in the southeast (Traveler's World RV Park) and northwest (University of Texas at San Antonio) of downtown San Antonio during summer 2017 to measure O3 and its precursors, including total nitrogen oxides (NOx) and volatile organic compounds (VOCs). Additional measurements included temperature, relative humidity, pressure, solar radiation, wind speed, wind direction, total reactive nitrogen (NOy), carbon monoxide (CO), and aerosol composition and concentration. We will use the campaign data and the NASA Langley Research Center (LaRC) Zero-Dimensional Box Model (Crawford et al., 1999; Olson et al., 2006) to calculate O3 production rate, NOx and hydroxyl radical chain length, and NOx versus VOCs sensitivity at different times of a day with different photochemical and meteorological conditions. A key to our understanding is to combine model results with measurements of precursor gases, particle chemistry and particle size to support the identification of O3 sources, its major formation pathways, and how the ozone production efficiency (OPE) depends on various factors. The resulting understanding of the causes of high O3 concentrations in the San Antonio area will provide insight into future air quality protection.

  4. Water quality modelling in the San Antonio River Basin driven by radar rainfall data

    Directory of Open Access Journals (Sweden)

    Almoutaz Elhassan

    2016-05-01

    Full Text Available Continuous monitoring of stream water quality is needed as it has significant impacts on human and ecological health and well-being. Estimating water quality between sampling dates requires model simulation based on the available geospatial and water quality data for a given watershed. Models such as the Soil and Water Assessment Tool (SWAT can be used to estimate the missing water quality data. In this study, SWAT was used to estimate water quality at a monitoring station near the outlet of the San Antonio River. Precipitation data from both rain gauges and weather radar were used to force the SWAT simulations. Virtual rain gauges which were based on weather radar data were created in the approximate centres of the 163 sub-watersheds of the San Antonio River Basin for SWAT simulations. This method was first tested in a smaller watershed in the middle of the Guadalupe River Basin resulting in increased model efficiency in simulating surface run-off. The method was then applied to the San Antonio River watershed and yielded good simulations for surface run-off (R2 = 0.7, nitrate (R2 = 0.6 and phosphate (R2 = 0.5 at the watershed outlet (Goliad, TX – USGS (United States Geological Survey gauge as compared to observed data. The study showed that the proper use of weather radar precipitation in SWAT model simulations improves the estimation of missing water quality data.

  5. Late Quaternary evolution of the San Antonio Submarine Canyon in the central Chile forearc (∼33°S)

    Science.gov (United States)

    Laursen, Jane; Normark, William R.

    2002-01-01

    Hydrosweep swath-bathymetry and seismic-reflection data reveal the morphology, sedimentary processes, and structural controls on the submarine San Antonio Canyon. The canyon crosses the forearc slope of the central Chile margin for more than 150 km before it empties into the Chile Trench near 33°S latitude. In its upper reaches, the nearly orthogonal segments of the San Antonio Canyon incise ∼1 km into thick sediment following underlying margin-perpendicular basement faults and along the landward side of a prominent margin-parallel thrust ridge on the outer mid-slope. At a breach in the outer ridge, the canyon makes a sharp turn into the San Antonio Reentrant. Resistance to erosion of outcropping basement at the head of the reentrant has prevented the development of a uniformly sloping thalweg, leaving gentle gradients (6°) across the lower slope. Emergence of an obstruction across the head of the San Antonio Reentrant has trapped sediment in the mid-slope segments of the canyon. Presently, little sediment appears to reach the Chile Trench through the San Antonio Canyon. The development of the San Antonio Canyon was controlled by the impact of a subducted seamount, which formed the San Antonio Reentrant and warped the middle slope along its landward advancing path. Incision of the canyon landward of the outer mid-slope ridge may be ascribed to a combination of headward erosion and entrenchment by captured unconfined turbidity currents. Flushing of the canyon was likely enhanced during the lowered sea level of the last glaciation. Where the canyon occupies the triangular embayment of the reentrant at the base of the slope, sediment has ponded behind a small accretionary ridge. On the trench floor opposite the San Antonio Canyon mouth, a 200-m-thick levee–overbank complex formed on the left side of a distributary channel emanating from a breach in the accretionary ridge. Axial transfer of sediment was inhibited to the north of the San Antonio Canyon mouth

  6. Food, feeding, and refuelling of Red Knots during northward migration at San Antonio Oeste, Rio Negro, Argentina

    NARCIS (Netherlands)

    Gonzalez, PM; Piersma, T; Verkuil, Y; González, Patricia M.

    1996-01-01

    We studied the food and feeding ecology of Red Knots Calidris canutus rufa on an area of rocky flat, or restinga, near San Antonio Oeste in the northwest of Golfo San Matias, Provincia de Rio Negro, Argentina in March 1992. These Red Knots are on their way north, from ''wintering'' areas in Tierra

  7. 78 FR 53243 - Safety Zone; TriRock San Diego, San Diego Bay, San Diego, CA

    Science.gov (United States)

    2013-08-29

    ... this rule because the logistical details of the San Diego Bay triathlon swim were not finalized nor... September 22, 2013. (c) Definitions. The following definition applies to this section: Designated...

  8. 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.

  9. 33 CFR 110.120 - San Luis Obispo Bay, Calif.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false San Luis Obispo Bay, Calif. 110... ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.120 San Luis Obispo Bay, Calif. (a) Area A-1. Area A-1 is the water area bounded by the San Luis Obispo County wharf, the shoreline, a line drawn...

  10. The new library building at the University of Texas Health Science Center at San Antonio.

    Science.gov (United States)

    Kronick, D A; Bowden, V M; Olivier, E R

    1985-04-01

    The new University of Texas Health Science Center at San Antonio Library opened in June 1983, replacing the 1968 library building. Planning a new library building provides an opportunity for the staff to rethink their philosophy of service. Of paramount concern and importance is the need to convey this philosophy to the architects. This paper describes the planning process and the building's external features, interior layouts, and accommodations for technology. Details of the move to the building are considered and various aspects of the building are reviewed.

  11. 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.

  12. Coastal Bend Texas Benthic Habitat - San Antonio Bay 2007 Substrate

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 2006 and 2007 the NOAA Office for Coastal Management purchased services to process existing digital multi-spectral imagery (ADS-40) and create digital benthic...

  13. 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

  14. 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...

  15. 75 FR 15611 - Safety Zone; United Portuguese SES Centennial Festa, San Diego Bay, San Diego, CA

    Science.gov (United States)

    2010-03-30

    ...-AA00 Safety Zone; United Portuguese SES Centennial Festa, San Diego Bay, San Diego, CA AGENCY: Coast... navigable waters of the San Diego Bay in support of the United Portuguese SES Centennial Festa. This... Centennial Festa, which will include a fireworks presentation originating from a tug and barge combination in...

  16. Rodriquez V. San Antonio Independent School District: Gathering the Ayes of Texas--The Politics of School Finance Reform

    Science.gov (United States)

    Yudof, Mark G.; Morgan, Daniel C.

    1974-01-01

    An historical account is given of movements toward educational finance reform in Texas, culminating in the Rodriquez v. San Antonio Independent School District case and its aftermath. The role of political pressures applied by various interest groups is traced and the prospects for future reform assessed. (EH)

  17. Modernizing "San Antonio Independent School District v. Rodriguez": How Evolving Supreme Court Jurisprudence Changes the Face of Education Finance Litigation

    Science.gov (United States)

    Saleh, Matthew

    2011-01-01

    This article aims to "modernize" the current legal debate over inequitable public school funding at the state and local level. The 1973 Supreme Court case of "San Antonio Independent School District v. Rodriguez" established precedent, allowing for property-tax based education funding programs at the state-level--a major source…

  18. 33 CFR 80.1130 - San Luis Obispo Bay, CA.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false San Luis Obispo Bay, CA. 80.1130 Section 80.1130 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1130 San Luis Obispo Bay, CA. A line drawn from...

  19. 76 FR 70480 - Otay River Estuary Restoration Project, South San Diego Bay Unit of the San Diego Bay National...

    Science.gov (United States)

    2011-11-14

    ... River Estuary Restoration Project, South San Diego Bay Unit of the San Diego Bay National Wildlife...), intend to prepare an environmental impact statement (EIS) for the proposed Otay River Estuary Restoration... any one of the following methods. Email: [email protected] . Please include ``Otay Estuary NOI'' in the...

  20. 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...

  1. Geochemistry of the thermal springs from San Antonio El Bravo zone, Chihuahua, Mexico; Geoquimica de manantiales termales de la zona de San Antonio El Bravo, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Tello Hinojosa, Enrique [Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico)

    1996-05-01

    Isotopic and chemical analysis o water produced by 14 springs in the San Antonio El Bravo, Chihuahua, Mexico geothermal area, were carried out in order to establish the geochemical characteristics of the groundwater and to know their interaction with deeper geothermal fluids. We made two samplings of water and gases in 1984 and 1995. The chemical composition of waters produced by the springs in of sodium-bicarbonate-chloride type. It was found, according to the Na:K:Mg relative content, that most hot springs are located in the partial equilibrium zone, whereas the lowest temperature hot springs shift toward the groundwaters domain. The temperature estimated from gas geothermometry was 129 degrees celsius. The isotopic composition at Ojo Caliente and Infiernito springs presents enrichment in {delta}{sup 18}O, product rock-water interaction at high temperature. The Agua Roque spring is located in the line of meteoric waters. Analysis of metals was carried out too, the concentration of gold element is 0.09 mg/l in Ojo Caliente and Infiernito springs, whereas silver, aluminum and iron elements were not detected. The water quality of the springs for agricultural use, is classified between C2-S1, C3-S1, C3- S2, C4-S3 and C4-S4 types, that suggests that only the water from Agua Roque can be used for irrigation. The arsenic element was not detected but the concentration of the boron element is high for irrigation use (2.39 ppm). [Espanol] Los analisis quimicos e isotopicos de agua de 14 manantiales de la zona de San Antonio El Bravo. Chihuahua, Mexico, fueron realizados con el fin de conocer las caracteristicas geoquimicas del acuifero somero y su interaccion con fluidos geotermicos. Se realizaron 2 muestreos tanto de agua como de gases en 1984 y 1995. En ambos muestreos se encontro que la composicion quimica del agua de todos los manantiales es del tipo bicarbonatado-clorurado-sodico. De acuerdo con el contenido relativo de Na:K:Mg el agua de los manantiales mas calientes

  2. 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

  3. Automated vehicle identification tags in San Antonio : lessons learned from the metropolitan model deployment initiative : unique method for collecting arterial travel speed information

    Science.gov (United States)

    2000-10-01

    This report demonstrates a unique solution to the challenge of providing accurate, timely estimates of arterial travel times to the motoring public. In particular, it discusses the lessons learned in deploying the Vehicle Tag Project in San Antonio, ...

  4. Appraisal of ground-water resources in the San Antonio Creek Valley, Santa Barbara County, California

    Science.gov (United States)

    Hutchinson, C.B.

    1980-01-01

    A nearly threefold increase in demand for water in the 154-square-mile San Antonio Creek valley in California during the period 1958-77 has increased the potential for overdraft on the ground-water basin. The hydrologic budget for this period showed a perennial yield of about 9,800 acre-feet per year and an annual ground-water discharge of about 11,400 acre-feet per year, comprising net pumpage of 7,100 acre-feet, phreatophyte evapotranspiration of 3,000 acre-feet, and base streamflow of 1 ,300 acre-feet. The base flow in San Antonio Creek could diminish to zero when net pumpage reaches 13,500 acre-feet per year. The environmentally sensitive marshland area of Barka Slough may then become stressed as water normally lost through evapotranspiration is captured by pumpage. The aquifer consists of alluvial valley fill that ranges in thickness from 0 to 3,500 feet. Ground water moves seaward from recharge areas along mountain fronts to a consolidated rock barrier about 5 miles east of the Pacific coast. Upwelling of ground water just east of the barrier has resulted in the 550-acre Barka Slough. Transmissivity of the aquifer ranges from 2,600 to 34,000 feet squared per day, with the lowest values occurring in the central part of the valley where the aquifer is thickest but probably finer grained. The salinity problems are increasing in the agricultural parts of the valley, which is east of the barrier. West of the barrier, stream and ground-water quality is poor, owing to seepage of saline water from the marine shale that underlies the area at shallow depths. A proposed basinwide monitoring program includes 17 water-level sites, 12 water-quality sampling sites, 3 streamflow measuring sites, and periodic infrared aerial photography of Barka Slough. A computer model of the ground-water flow system could be developed to assess the impact of various water-management alternatives. (USGS)

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. Local adaptation of the National Physical Activity Plan: creation of the Active Living Plan for a Healthier San Antonio.

    Science.gov (United States)

    Esparza, Laura A; Velasquez, Katherine S; Zaharoff, Annette M

    2014-03-01

    Physical inactivity and related health consequences are serious public health threats. Effective strategies to facilitate and support active-living opportunities must be implemented at national, state, and local levels. San Antonio, Texas, health department officials launched the Active Living Council of San Antonio (ALCSA) to engage the community in developing a 3- to 5-year plan to promote active living. A steering committee set preliminary ALCSA aims and established a multisector membership structure modeled after the US National Physical Activity Plan (NPAP). ALCSA adopted governance standards, increased knowledge of physical activity and health, and engaged in an 18-month collaborative master plan writing process. ALCSA selected overarching strategies and evidence-based strategies for each societal sector and adapted strategies to the local context, including tactics, measures of success, and timelines. Community and expert engagement led to a localized plan reflecting national recommendations, the Active Living Plan for a Healthier San Antonio. Multisector collaborations among governmental agencies and community organizations, which were successfully developed in this case to produce the first-ever local adaptation of the NPAP, require clearly defined expectations. Lessons learned in ALCSA's organizational and plan development can serve as a model for future community-driven efforts to increase active living.

  10. 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,...

  11. Building America Case Study: Occupant Comfort from a Mini-Split Heat Pump, San Antonio, Texas

    Energy Technology Data Exchange (ETDEWEB)

    2017-03-03

    IBACOS worked with builder Imagine Homes to evaluate the performance of an occupied new construction test house following construction of the house in the hot, humid climate of San Antonio, Texas. The project measures the effectiveness of a space conditioning strategy using a multihead mini-split heat pump (MSHP) system in a reduced-load home to achieve acceptable comfort levels (temperature and humidity) and energy performance. IBACOS collected long-term data and analyzed the energy consumption and comfort conditions of the occupied house after one year of operation. Although measured results indicate that the test system provides comfort both inside and outside the ASHRAE Standard 55-2010 range, the occupants of the house claimed both adequate comfort and appreciation of the ease of use and flexibility of the installed MSHP system. IBACOS also assisted the builder to evaluate design and specification changes necessary to comply with Zero Energy Ready Home, but the builder chose to not move forward with it because of concerns about the 'solar ready' requirements of the program.

  12. Aerial radiometric and magnetic survey: San Antonio National Topographic Map, Texas. Final report

    International Nuclear Information System (INIS)

    1980-05-01

    The results of analyses of the airborne gamma radiation and total magnetic field survey flown for the region identified as the San Antonio National Topographic Map NH14-8 are presented. The airborne data gathered are reduced by ground computer facilities to yield profile plots of the basic uranium, thorium, and potassium equivalent gamma radiation intensities, ratios of these intensities, aircraft altitude above the earth's surface, total gamma ray and earth's magnetic field intensity, correlated as a function of geologic units. The distribution of data within each geologic unit, for all surveyed map lines and tie lines, has been calculated and is included. Two sets of profiled data for each line are included, with one set displaying the above-cited data. The second set includes only flight line magnetic field, temperature, pressure, altitude data plus magnetic field data as measured at a base station. A general description of the area, including descriptions of the various geologic units and the corresponding airborne data, is included also

  13. 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...

  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. 77 FR 42649 - Safety Zone: Sea World San Diego Fireworks, Mission Bay; San Diego, CA

    Science.gov (United States)

    2012-07-20

    ... 1625-AA00 Safety Zone: Sea World San Diego Fireworks, Mission Bay; San Diego, CA AGENCY: Coast Guard... authorized by the Captain of the Port, or his designated representative. DATES: This rule is effective from 8... to ensure the public's safety. B. Basis and Purpose The Ports and Waterways Safety Act gives the...

  16. 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...

  17. Como güelfos y gibelinos: los colegios de San Bernardo y San Antonio Abad en el Cuzco durante el siglo XVII

    Directory of Open Access Journals (Sweden)

    Guibovich Pérez, Pedro M

    2006-04-01

    Full Text Available This article deals with the conflicts that involved the San Bernardo and San Antonio schools all along the seventeenth century. The author proposes a new approach to explain the social history of colonial Cuzco. He mantains that the root of the confrontation has to do with the privileges that enjoy the jesuits in the provision of academical degrees, a basic requirement to obtain appointments in the civil and eclesiastical administration. To understand this social dinamic, he reconstructs the institutional history of both schools, and reveals the interests that defend the main actors of this secular conflict.

    Los conflictos que enfrentaron a los colegios de San Bernardo y San Antonio Abad a lo largo del siglo XVII es el tema central de estudio de este ensayo. El autor propone una nueva lectura a este episodio de la historia social del Cuzco colonial. Sostiene que en la raíz de los enfrentamientos estuvo el privilegio que gozaban los jesuitas para la concesión de grados académicos, requisitos fundamentales para obtener cargos en la administración civil y eclesiástica. Para entender la dinámica social, el autor reconstruye la historia institucional de los colegios y los intereses en juego de los principales protagonistas del secular conflicto.

  18. Attractiveness of botanical infusions to ovipositing Culex quinquefasciatus, Cx. nigripalpus, and Cx. erraticus in San Antonio, Texas.

    Science.gov (United States)

    McPhatter, Lee P; Debboun, Mustapha

    2009-12-01

    Field experiments were conducted on the Fort Sam Houston Military Reservation, San Antonio, TX, in fall 2008 to observe the attractiveness of selected botanical infusions to ovipositing female mosquitoes. The following infusions were tested in Centers for Disease Control and Prevention gravid traps: Bermuda grass (Cynodon dactylon), oak leaf (Quercus virginiana), acacia leaf (Acacia schaffneri), rabbit chow (alfalfa pellets), and algae (Spirogyra sp.). Four (Bermuda, acacia, oak, and algae) of the 5 infusions were effective in collecting Culex quinquefasciatus, Cx. nigripalpus, and Cx. erraticus. Of the 4 infusions, Bermuda collected the greatest number of the mosquitoes sampled. Female Aedes albopictus mosquitoes were collected in moderate numbers during this study.

  19. Report on investigations in fiscal 2000 on the basic investigation on promotion of joint implementation. Rehabilitation of ICE/SAN ANTONIO power plant; 2000 nendo kyodo jisshi nado suishin kiso chosa hokokusho. ICE/SAN ANTONIO hatsudensho rihabiri

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    Costa Rica takes a power generation system using hydro power generation as the main source, and possesses medium-capacity gas turbines to supplement needs in the dry season and the peak load. However, a problem has come up that, in addition to the cost rise in gas turbine fuel, the power generation efficiency has been aggravating due to aged deterioration of the generators being used. In association therewith, the problem is now a factor to increase CO2 emission, which is a worldwide problem. Keeping in mind to link it to the clean development mechanism (CDM), the present project is, taking up the SAN ANTONIO power plant as the investigation object, intended to perform a comprehensive discussion on the CO2 emission reducing effect, profitability, and proliferation effect, by executing the conceptual plant design. The up-grading plan for thermal power generation systems in Costa Rica consists of replacement of the gas turbines, handling of phase modifiers, and achievement of the combined cycle. The plan agrees with the present feasibility study intended of CO2 emission reduction, consisting of the modification plan of the SAN ANTONIO power plant, that is the plan to replace the over-aged gas turbines at the power plant. Its necessity has been identified. It was disclosed that the project has the effects of reducing CO2 of 82,000 tons annually, and the investment can be recovered in nine years. (NEDO)

  20. Calidad de atención y su influencia en el usuario externo en el centro de salud San Antonio de Pedregal 2015

    OpenAIRE

    Lozano Sotil, Ruth Consuelo

    2016-01-01

    El trabajo de investigación titulada “Calidad de atención y su influencia en el usuario externo en el Centro de Salud San Antonio de Pedregal Chosica 2015”se realizó con el objetivo de determinar el nivel de satisfacción del usuario externo sobre calidad de atención percibida en el Centro de Salud San Antonio de Pedregal 2015. La variable de estudio es calidad de atención en el usuario externo El estudio fué cuantitativo de tipo descriptivo transversal tuvo como población mu...

  1. 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…

  2. Annual compilation and analysis of hydrologic data for Escondido Creek, San Antonio River basin, Texas

    Science.gov (United States)

    Reddy, D.R.

    1971-01-01

    IntroductionHistory of Small Watershed Projects in TexasThe U.S. Soil Conservation Service is actively engaged in the installation of flood and soil erosion reducing measures in Texas under the authority of the "Flood Control Act of 1936 and 1944" and "Watershed Protection and Flood Prevention Act" (Public Law 566), as amended. The Soil Conservation Service has found a total of approximately 3,500 floodwater-retarding structures to be physically and economically feasible in Texas. As of September 30, 1970, 1,439 of these structures had been built.This watershed-development program will have varying but important effects on the surface and ground-water resources of river basins, especially where a large number of the floodwater-retarding structures are built. Basic hydrologic data under natural and developed conditions are needed to appraise the effects of the structures on the yield and mode of occurrence of runoff.Hydrologic investigations of these small watersheds were begun by the Geological Survey in 1951 and are now being made in 12 study areas (fig. 1). These investigations are being made in cooperation with the Texas Water Development Board, the Soil Conservation Service, the San Antonio River Authority, the city of Dallas, and the Tarrant County Water Control and Improvement District No. 1. The 12 study areas were chosen to sample watershed having different rainfall, topography, geology, and soils. In five of the study areas, (North, Little Elm, Mukewater, little Pond-North Elm, and Pin Oak Creeks), streamflow and rainfall records were collected prior to construction of the floodwater-retarding structures, thus affording the opportunity for analyses of the conditions "before and after" development. A summary of the development of the floodwater-retarding structures in each study areas of September 30, 1970, is shown in table 1.Objectives of the Texas Small Watersheds ProjectThe purpose of these investigations is to collect sufficient data to meeting the

  3. 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...

  4. Preliminary three-dimensional geohydrologic framework of the San Antonio Creek Groundwater Basin, Santa Barbara County, California

    Science.gov (United States)

    Cromwell, G.; Sweetkind, D. S.; O'leary, D. R.

    2017-12-01

    The San Antonio Creek Groundwater Basin is a rural agricultural area that is heavily dependent on groundwater to meet local water demands. The U.S. Geological Survey (USGS) is working cooperatively with Santa Barbara County and Vandenberg Air Force Base to assess the quantity and quality of the groundwater resources within the basin. As part of this assessment, an integrated hydrologic model that will help stakeholders to effectively manage the water resources in the basin is being developed. The integrated hydrologic model includes a conceptual model of the subsurface geology consisting of stratigraphy and variations in lithology throughout the basin. The San Antonio Creek Groundwater Basin is a relatively narrow, east-west oriented valley that is structurally controlled by an eastward-plunging syncline. Basin-fill material beneath the valley floor consists of relatively coarse-grained, permeable, marine and non-marine sedimentary deposits, which are underlain by fine-grained, low-permeability, marine sedimentary rocks. To characterize the system, surficial and subsurface geohydrologic data were compiled from geologic maps, existing regional geologic models, and lithology and geophysical logs from boreholes, including two USGS multiple-well sites drilled as part of this study. Geohydrologic unit picks and lithologic variations are incorporated into a three-dimensional framework model of the basin. This basin (model) includes six geohydrologic units that follow the structure and stratigraphy of the area: 1) Bedrock - low-permeability marine sedimentary rocks; 2) Careaga Formation - fine to coarse grained near-shore sandstone; 3) Paso Robles Formation, lower portion - sandy-gravely deposits with clay and limestone; 4) Paso Robles Formation, middle portion - clayey-silty deposits; 5) Paso Robles Formation, upper portion - sandy-gravely deposits; and 6) recent Quaternary deposits. Hydrologic data show that the upper and lower portions of the Paso Robles Formation are

  5. Characterizing the Organic Matter in Surface Sediments from the San Juan Bay Estuary,

    Science.gov (United States)

    The San Juan Bay Estuary (SJBE) is located on the north coast of Puerto Rico and includes the San Juan Bay, San José Lagoon, La Torrecilla Lagoon and Piñones Lagoon, as well as the Martín Peña and the Suárez Canals. The SJBE watershed has the highest...

  6. 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.

  7. 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.

  8. 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.

  9. San Pablo Bay Tidal Marsh Enhancement and Water Quality Improvement Project

    Science.gov (United States)

    Information about the SFBWQP San Pablo Bay Tidal Marsh Enhancement and Water Quality Improvement Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  10. Simulation of flow in the Edwards Aquifer, San Antonio region, Texas, and refinement of storage and flow concepts

    Science.gov (United States)

    Maclay, Robert W.; Land, Larry F.

    1988-01-01

    The Edwards aquifer is a complexly faulted, carbonate aquifer lying within the Balcones fault zone of south-central Texas. The aquifer consists of thin- to massive-bedded limestone and dolomite, most of which is in the form of mudstones and wackestones. Well-developed secondary porosity has formed in association with former erosional surfaces within the carbonate rocks, within dolomitized-burrowed tidal and evaporitic deposits, and along inclined fractures to produce an aquifer with transmissivities greater than 100 ft2/s. The aquifer is recharged mainly by streamflow losses in the outcrop area of the Edwards aquifer and is discharged by major springs located at considerable distances, as much as 150 mi, from the areas of recharge and by wells. Ground-water flow within the Edwards aquifer of the San Antonio region was simulated to investigate concepts relating to the storage and flow characteristics. The concepts of major interest were the effects of barrier faults on flow direction, water levels, springflow, and storage within the aquifer. A general-purpose, finite-difference model, modified to provide the capability of representing barrier faults, was used to simulate ground-water flow and storage in the aquifer. The approach in model development was to conduct a series of simulations beginning with a simple representation of the aquifer framework and then proceeding to subsequent representations of increasing complexity. The simulations investigated the effects of complex geologic structures and of significant changes in transmissivity, anisotropy, and storage coefficient. Initial values of transmissivity, anisotropy, and storage coefficient were estimated based on concepts developed in previous studies. Results of the simulations confirmed the original estimates of transmissivity values (greater than 100 square feet/s) in the confined zone of the aquifer between San Antonio and Comal Springs. A storage coefficient of 0.05 in the unconfined zone of the aquifer

  11. [B_Erandio_Martiartu] Documentación del conjunto formado por la Torre de Martiartu y la ermita de San Antonio (Erandio, Bizkaia)

    OpenAIRE

    Álvarez González, Irantzu; Lopetegi Galarraga, Ane; Mesanza Moraza, Amaia; Rodríguez Miranda, Álvaro; Valle Melón, José Manuel

    2002-01-01

    [ES] El conjunto está formado por la torre de Martiartu (de unas 16 x 16 metros de planta), la pequeña ermita de la San Antonio y el área circundante. La documentación de la torre se realiza mediante fotogrametría estereoscópica y rectificación fotográfica para la obtención de las ortoimágenes. La ermita de San Antonio y el entorno se ha documentado mediante estación total y mallado para crear un modelo de superficies tridimensional. Posteriormente se presentan los modelos 3D y la colecció...

  12. 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.

  13. 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...

  14. 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...

  15. 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...

  16. ¿“Tierra de Gauchos” o “Gaucholandia”? Autenticidad en San Antonio de Areco (Argentina.

    Directory of Open Access Journals (Sweden)

    Cecilia Pérez Winter

    2016-01-01

    Full Text Available En este artículo proponemos analizar cómo la autenticidad es definida por diversos sujetos que se involucran en los procesos de valorización patrimonial y turística de una ciudad. En particular, cómo esa cualidad es disputada, discursiva y materialmente, a través del tiempo. Sostenemos que el discurso, o la idea de, autenticidad puede ser implementada por diferentes sectores de una comunidad, ya sea como un forma de legitimar/deslegitimar proyectos turísticos ‑patrimoniales, o para controlar la activación de los “patrimonios/atractivos”. Proponemos como estudio de caso la ciudad de San Antonio de Areco, localizada en la provincia de Buenos Aires ‑Argentina. Allí nos interesar indagar estos temas, a partir de examinar las tensiones que emergen entre las representaciones identitarias y la lógica turística/comercial, al mercantilizar elementos significativos asociados a la activación de un tipo de tradición y de gaucho.

  17. 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.

  18. Degradation of tributyltin in San Diego Bay, California, waters

    International Nuclear Information System (INIS)

    Seligman, P.F.; Valkirs, A.O.; Lee, R.F.

    1986-01-01

    Several experiments were carried out to determine the degradation rate of tributyltin (TBT) in microcosms containing harbor water. Unlabeled or 14 C-labeled tributyltin was added to water samples collected from two stations in San Diego Bay, CA. Degradation rates were determined by calculating the rate of loss of the added parent TBT compound. Calculated half-lives in water collected from a yacht harbor (ambient concentration was 0.5 μg of TBT/L) were 6 and 7 days for light and dark treatments, respectively. Half-lives from a clean-water site ( 14 CO 2 , proceeded slowly with a half-life of 50-75 days. Tributyltin at high concentrations (744 μg/L) was not degraded in sunlight, indicating that photolysis was not taking place and that biological degradation was the primary degradative process for TBT at low ambient concentrations

  19. 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.

  20. 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.

  1. Simulations of groundwater flow and particle-tracking analysis in the zone of contribution to a public-supply well in San Antonio, Texas

    Science.gov (United States)

    Lindgren, Richard L.; Houston, Natalie A.; Musgrove, MaryLynn; Fahlquist, Lynne S.; Kauffman, Leon J.

    2011-01-01

    In 2006, a public-supply well in San Antonio, Texas, was selected for intensive study to assess the vulnerability of public-supply wells in the Edwards aquifer to contamination by a variety of compounds. A local-scale, steady-state, three-dimensional numerical groundwater-flow model was developed and used in this study to evaluate the movement of water and solutes from recharge areas to the selected public-supply well. Particle tracking was used to compute flow paths and advective traveltimes throughout the model area and to delineate the areas contributing recharge and zone of contribution for the selected public-supply well.

  2. Work to diminish the danger of forest fires in the municipalities San Antonio del Sur and Imías, Guantánamo

    OpenAIRE

    Edelmys Perez Pereda; Lianet Ramírez Fernández; Jessika Massó Matos; Francisco Duran Manual

    2017-01-01

    The research was carried out in the forest patrimony in San Antonio and Imías municipality in the province of Guantánamo, with the aim to propose actions to diminish the occurrence and propagation of the forest fires in the municipalities objects of study. For this, the temporal distribution of fires and burned areas, in the period 2006-2015, through the year, the week and the day was taken into account and also the causes that povoque the fires. With these elements, the activities to be carr...

  3. 76 FR 25548 - Safety Zone; Coast Guard Use of Force Training Exercises, San Pablo Bay, CA

    Science.gov (United States)

    2011-05-05

    ... disturbances to waterfowl and referenced a study by the USGS confirming foraging areas in San Pablo Bay are used by diving ducks. In the Consistency Determination, the USGS was contacted and determined that the...

  4. 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...

  5. 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...

  6. 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.

  7. U.S. Geological Survey Karst Interest Group Proceedings, San Antonio, Texas, May 16–18, 2017

    Science.gov (United States)

    Kuniansky, Eve L.; Spangler, Lawrence E.

    2017-05-15

    Buffalo National River in the southern Ozarks, and a keynote presentation on paleokarst in the United States was delivered by Art and Peggy Palmer. The sixth KIG workshop was hosted by the National Cave and Karst Research Institute (NCKRI) in 2014, in Carlsbad, New Mexico. George Veni, Director of the NCKRI, served as a co-chair of the workshop with Eve Kuniansky of the USGS. The workshop featured speaker Dr. Penelope Boston, Director of Cave and Karst Studies at New Mexico Tech, Socorro, and Academic Director at the NCKRI, who addressed the future of karst research. The field trip on evaporite karst of the lower Pecos Valley was led by Lewis Land (NCKRI karst hydrologist), and the field trip on the geology of Carlsbad Caverns National Park was led by George Veni.This current seventh KIG workshop is being held in San Antonio at the University of Texas at San Antonio (UTSA). This 2017 workshop is being hosted by the Department of Geological Sciences’ Student Geological Society (SGS), and student chapters of the American Association of Petroleum Geologists (AAPG) and Association of Engineering Geologists (AEG), with support by the UTSA Department of Geological Sciences and Center for Water Research. The UTSA student chapter presidents, Jose Silvestre (SGS), John Cooper (AAPG), and Tyler Mead (AEG) serve as co-chairs of the 2017 workshop with Eve Kuniansky of the USGS. The technical session committee is chaired by Eve Kuniansky, USGS, and includes Michael Bradley, Tom Byl, Rebecca Lambert, John Lane, and James Kaufmann, all USGS, and Patrick Tucci, retired USGS. The logistics committee includes Amy Clark, Yongli Gao, and Lance Lambert (Department Chair), UTSA Department of Geological Sciences; and Ryan Banta and Allan Clark, USGS, San Antonio, Texas. The field trip committee is chaired by Allan Clark and includes Amy Clark, Yongli Gao, and Keith Muehlestein, UTSA; Marcus Gary, Edwards Aquifer Authority and University of Texas at Austin; Ron Green, Southwest Research

  8. 33 CFR 334.860 - San Diego Bay, Calif., Naval Amphibious Base; restricted area.

    Science.gov (United States)

    2010-07-01

    ... Amphibious Base; restricted area. 334.860 Section 334.860 Navigation and Navigable Waters CORPS OF ENGINEERS... Bay, Calif., Naval Amphibious Base; restricted area. (a) The Area. The water of the Pacific Ocean in Middle San Diego Bay in an area extending from the northern and eastern boundary of the Naval Amphibious...

  9. 75 FR 19248 - Subject: Safety Zone; Sea World Summer Nights Fireworks, Mission Bay, San Diego, CA

    Science.gov (United States)

    2010-04-14

    ... can better evaluate its effects on them and participate in the rulemaking process. Small businesses...-AA00 Subject: Safety Zone; Sea World Summer Nights Fireworks, Mission Bay, San Diego, CA AGENCY: Coast... navigable waters of Mission Bay in support of the Sea World Summer Nights Fireworks. This safety zone is...

  10. Assessing the vulnerability of public-supply wells to contamination—Edwards aquifer near San Antonio, Texas

    Science.gov (United States)

    Jagucki, Martha L.; Musgrove, MaryLynn; Lindgren, Richard J.; Fahlquist, Lynne; Eberts, Sandra M.

    2011-01-01

    This fact sheet highlights findings from the vulnerability study of a public-supply well field in San Antonio, Texas. The well field consists of six production wells that tap the Edwards aquifer. Typically, one or two wells are pumped at a time, yielding an average total of 20-21 million gallons per day. Water samples were collected from public-supply wells in the well field and from monitoring wells installed along general directions of flow to the well field. Samples from the well field contained some constituents of concern for drinking-water quality, including nitrate; the pesticide compounds atrazine, deethylatrazine, and simazine; and the volatile organic compounds tetrachloroethene (also called perchloroethene, or PCE), chloroform, bromoform, and dibromochloromethane. These constituents were detected in untreated water at concentrations much less than established drinking-water standards, where such standards exist. Overall, the study findings point to four primary factors that affect the movement and fate of contaminants and the vulnerability of the public-supply well field in San Antonio, Texas: (1) groundwater age (how long ago water entered, or recharged, the aquifer), (2) fast pathways for flow of groundwater through features formed or enlarged by dissolution of bedrock, (3) recharge characteristics of the aquifer, and (4) natural geochemical processes within the aquifer. A computer-model simulation of groundwater flow and transport was used to estimate the traveltime (or age) of water particles entering public-supply well W4 in the well field. Modeled findings show that almost half of the water reaching the public-supply well is less than 2 years old. Such a large percentage of very young water indicates that (1) contaminants entering the aquifer may be transported rapidly to the well, (2) there is limited time for chemical reactions to occur in the aquifer that may attenuate contaminants, and (3) should recharge water become contaminated with

  11. 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

  12. 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.

  13. 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)

  14. 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

  15. Does centennial morphodynamic evolution lead to higher channel efficiency in San Pablo Bay, California?

    Science.gov (United States)

    van der Wegen, M.; Jaffe, B.E.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    Measured bathymetries on 30 year interval over the past 150 years show that San Pablo Bay experienced periods of considerable deposition followed by periods of net erosion. However, the main channel in San Pablo Bay has continuously narrowed. The underlying mechanisms and consequences of this tidal channel evolution are not well understood. The central question of this study is whether tidal channels evolve towards a geometry that leads to more efficient hydraulic conveyance and sediment throughput. We applied a hydrodynamic process-based, numerical model (Delft3D), which was run on 5 San Pablo Bay bathymetries measured between 1856 and 1983. Model results shows increasing energy dissipation levels for lower water flows leading to an approximately 15% lower efficiency in 1983 compared to 1856. During the same period the relative seaward sediment throughput through the San Pablo Bay main channel increased by 10%. A probable explanation is that San Pablo Bay is still affected by the excessive historic sediment supply. Sea level rise and Delta surface water area variations over 150 years have limited effect on the model results. With expected lower sediment concentrations in the watershed and less impact of wind waves due to erosion of the shallow flats, it is possible that energy dissipations levels will decrease again in future decades. Our study suggests that the morphodynamic adaptation time scale to excessive variations in sediment supply to estuaries may be on the order of centuries.

  16. Updated numerical model with uncertainty assessment of 1950-56 drought conditions on brackish-water movement within the Edwards aquifer, San Antonio, Texas

    Science.gov (United States)

    Brakefield, Linzy K.; White, Jeremy T.; Houston, Natalie A.; Thomas, Jonathan V.

    2015-01-01

    In 2010, the U.S. Geological Survey, in cooperation with the San Antonio Water System, began a study to assess the brackish-water movement within the Edwards aquifer (more specifically the potential for brackish-water encroachment into wells near the interface between the freshwater and brackish-water transition zones, referred to in this report as the transition-zone interface) and effects on spring discharge at Comal and San Marcos Springs under drought conditions using a numerical model. The quantitative targets of this study are to predict the effects of higher-than-average groundwater withdrawals from wells and drought-of-record rainfall conditions of 1950–56 on (1) dissolved-solids concentration changes at production wells near the transition-zone interface, (2) total spring discharge at Comal and San Marcos Springs, and (3) the groundwater head (head) at Bexar County index well J-17. The predictions of interest, and the parameters implemented into the model, were evaluated to quantify their uncertainty so the results of the predictions could be presented in terms of a 95-percent credible interval.

  17. Comportamiento del cáncer cérvicouterino en el municipio San Antonio del Sur de Guantánamo

    OpenAIRE

    Salvent Tames, Adrian; Rodríguez Lara, Osvaldo; Leyva Lambert, Marlenis; Gamboa Rodríguez, Mailin; Columbié Gámez, Mirta

    2012-01-01

    Introducción: no son pocos los esfuerzos que se realizan para combatir el cáncer cérvicouterino, a pesar de que existe un programa de detección precoz, estamos lejos aún de alcanzar la meta propuesta. Objetivo: conocer el comportamiento del cáncer cérvicouterino en el municipio de San Antonio del Sur de la provincia Guantánamo en el periodo 2006-2010. Métodos: el universo de estudio quedó constituido por las 254 pacientes que tuvieron una citología orgánica con diagnóstico positivo de lesione...

  18. Making lemonade from lemons: a case study on loss of space at the Dolph Briscoe, Jr. Library, University of Texas Health Science Center at San Antonio.

    Science.gov (United States)

    Tobia, Rajia C; Feldman, Jonquil D

    2010-01-01

    The setting for this case study is the Dolph Briscoe, Jr. Library, University of Texas Health Science Center at San Antonio, a health sciences campus with medical, dental, nursing, health professions, and graduate schools. During 2008-2009, major renovations to the library building were completed including office space for a faculty development department, multipurpose classrooms, a 24/7 study area, study rooms, library staff office space, and an information commons. The impetus for changes to the library building was the decreasing need to house collections in an increasingly electronic environment, the need for office space for other departments, and growth of the student body. About 40% of the library building was remodeled or repurposed, with a loss of approximately 25% of the library's original space. Campus administration proposed changes to the library building, and librarians worked with administration, architects, and construction managers to seek renovation solutions that meshed with the library's educational mission.

  19. Regional scale flood modeling using NEXRAD rainfall, GIS, and HEC-HMS/RAS: a case study for the San Antonio River Basin Summer 2002 storm event.

    Science.gov (United States)

    Knebl, M R; Yang, Z-L; Hutchison, K; Maidment, D R

    2005-06-01

    This paper develops a framework for regional scale flood modeling that integrates NEXRAD Level III rainfall, GIS, and a hydrological model (HEC-HMS/RAS). The San Antonio River Basin (about 4000 square miles, 10,000 km2) in Central Texas, USA, is the domain of the study because it is a region subject to frequent occurrences of severe flash flooding. A major flood in the summer of 2002 is chosen as a case to examine the modeling framework. The model consists of a rainfall-runoff model (HEC-HMS) that converts precipitation excess to overland flow and channel runoff, as well as a hydraulic model (HEC-RAS) that models unsteady state flow through the river channel network based on the HEC-HMS-derived hydrographs. HEC-HMS is run on a 4 x 4 km grid in the domain, a resolution consistent with the resolution of NEXRAD rainfall taken from the local river authority. Watershed parameters are calibrated manually to produce a good simulation of discharge at 12 subbasins. With the calibrated discharge, HEC-RAS is capable of producing floodplain polygons that are comparable to the satellite imagery. The modeling framework presented in this study incorporates a portion of the recently developed GIS tool named Map to Map that has been created on a local scale and extends it to a regional scale. The results of this research will benefit future modeling efforts by providing a tool for hydrological forecasts of flooding on a regional scale. While designed for the San Antonio River Basin, this regional scale model may be used as a prototype for model applications in other areas of the country.

  20. 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.

  1. 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

  2. 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.

  3. Creating Safe Growth Strategies for the San Francisco Bay Area

    Science.gov (United States)

    Report from a technical assistance project with the Association of Bay Area Governments to develop strategies to ensure that growth in the region is resilient to hazards such as earthquakes and sea level rise, but also affordable and transit accessible.

  4. 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...

  5. 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...

  6. 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.

  7. 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

  8. 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. 

  9. Distribution and temporal variation of trace metal enrichment in surface sediments of San Jorge Bay, Chile.

    Science.gov (United States)

    Valdés, Jorge; Román, Domingo; Guiñez, Marcos; Rivera, Lidia; Morales, Tatiana; Morales, Tomás; Avila, Juan; Cortés, Pedro

    2010-08-01

    Cu, Pb, and Hg concentrations were determined in surface sediment samples collected at three sites in San Jorge Bay, northern Chile. This study aims to evaluate differences in their spatial distribution and temporal variability. The highest metal concentrations were found at the site "Puerto", where minerals (Cu and Pb) have been loaded for more than 60 years. On the other hand, Hg does not pose a contamination problem in this bay. Cu and Pb concentrations showed significant variations from 1 year to another. These variations seem to be a consequence of the combination of several factors, including changes in the loading and/or storage of minerals in San Jorge Bay, the dredging of bottom sediments (especially at Puerto), and seasonal changes in physical-chemical properties of the water column that modify the exchange of metals at the sediment-water interface. Differences in the contamination factor and geoaccumulation index suggest that pre-industrial concentrations measured in marine sediments of this geographical zone, were better than geological values (average shale, continental crust average) for evaluating the degree of contamination in this coastal system. Based on these last two indexes, San Jorge Bay has a serious problem of Cu and Pb pollution at the three sampling locations. However, only Cu exceeds the national maximum values used to evaluate ecological risk and the health of marine environments. It is suggested that Chilean environmental legislation for marine sediment quality--presently under technical discussion--is not an efficient tool for protecting the marine ecosystem.

  10. 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.

  11. 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

  12. 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.

  13. Work to diminish the danger of forest fires in the municipalities San Antonio del Sur and Imías, Guantánamo

    Directory of Open Access Journals (Sweden)

    Edelmys Perez Pereda

    2017-08-01

    Full Text Available The research was carried out in the forest patrimony in San Antonio and Imías municipality in the province of Guantánamo, with the aim to propose actions to diminish the occurrence and propagation of the forest fires in the municipalities objects of study. For this, the temporal distribution of fires and burned areas, in the period 2006-2015, through the year, the week and the day was taken into account and also the causes that povoque the fires. With these elements, the activities to be carried out to reduce the occurrence and propagation of forest fires were planned. The data were obtained in the fire reports of the CGB of Guantánamo province. Among the significant results train, the recent years the number of fire events has increased, most of them occur between march and may; usually from 8:00 am to 9:00 pm and the weekend is where there is the greatest risk of occurrence. The general cause that provoque the greatest number of fires is negligence. Therefore, it is necessary to implement an adequate protection plan against fire making great emphasis on the prevention of fires provoqued by humans and to take measures to modify the structure and composition of the combustible material.

  14. Mecenazgo religioso y estrategias familiares en la Segovia del siglo XV: Diego Árias de Ávila y el Hospital de San Antonio

    Directory of Open Access Journals (Sweden)

    Rábade Obradó, María del Pilar

    2002-12-01

    Full Text Available The present work studies the foundation of Saint Anthony´s hospital of Segovia during the XVth century. The foundation was an initiative of Diego Arias de Ávila, one of the most influential personalities of the reign of Henry IV of Castila. The foundation was determined on very varied reasons, not only charitative and religious reasons. Among these reasons, the use of the hospital as an instrument of the family strategies. These family strategies tried to hidden the hebrew origins of the lineage. They also tried to guarantee the perennity of the lineage, and to leave an endurable memory behind. Lasdy, these family strategies tried to consolidate the domination that the lineage had on Segovia.

    El presente trabajo estudia la fundación del hospital de San Antonio de Segovia en el siglo XV. La fundación fue una iniciativa de Diego Arias de Ávila, uno de los personajes más influyentes durante el reinado de Enrique IV de Castilla. La fundación estuvo determinada por motivaciones muy diversas, no sólo caritativas y religiosas. Entre ellas, el uso del hospital como instrumento de las estrategias familiares. Esas estrategias familiares pretendían ocultar los orígenes judíos del linaje, garantizar su perennidad, dejar una memoria perdurable del mismo, y, finalmente, consolidar la dominación que el linaje ejercía sobre Segovia.

  15. 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...

  16. 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...

  17. 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...

  18. 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

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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. 

  4. Mussels as Bioindicators: A Case Study of Tributyltin Effects in San Diego Bay.

    Science.gov (United States)

    As part of a Navy research program to evaluate the environmental effects of tributyltin ( TBT ) antifouling coatings and develop in-situ field...documented temporal and spatial variability in TBT and the effects of TBT on growth, bioaccumulation and survival that have not been previously...the mussel bioidicator for assessing TBT effects in San Diego Bay and establishes a significant refinement in the use of mussels as biological

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 78 FR 42027 - Safety Zone; San Diego Bayfair; Mission Bay, San Diego, CA

    Science.gov (United States)

    2013-07-15

    ... safety zones. Thunderboats Unlimited Inc. is sponsoring San Diego Bayfair, which is held on the navigable... distribution of power and responsibilities between the Federal Government and Indian tribes. 12. Energy Effects This proposed rule is not a ``significant energy action'' under Executive Order 13211, Actions...

  10. 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

  11. 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

  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. 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.

  14. 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...

  15. 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.

  16. 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.

  17. 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.

  18. Magmatic controls on eruption dynamics of the 1950 yr B.P. eruption of San Antonio Volcano, Tacaná Volcanic Complex, Mexico-Guatemala

    Science.gov (United States)

    Mora, Juan Carlos; Gardner, James Edward; Macías, José Luis; Meriggi, Lorenzo; Santo, Alba Patrizia

    2013-07-01

    San Antonio Volcano, in the Tacaná Volcanic Complex, erupted ~ 1950 yr. B.P., with a Pelean type eruption that produced andesitic pyroclastic surges and block-and-ash flows destroying part of the volcano summit and producing a horse-shoe shaped crater open to the SW. Between 1950 and 800 yr B.P. the eruption continued with effusive andesites followed by a dacite lava flow and a summit dome, all from a single magma batch. All products consist of phenocrysts and microphenocrysts of zoned plagioclase, amphibole, pyroxene, magnetite ± ilmenite, set in partially crystallized groundmass of glass and microlites of the same mineral phases, except for the lack of amphibole. Included in the andesitic blocks of the block-and-ash flow deposit are basaltic andesite enclaves with elongated and ellipsoidal forms and chilled margins. The enclaves have intersertal textures with brown glass between microphenocrysts of plagioclase, hornblende, pyroxene, and olivine, and minor proportions of phenocrysts of plagioclase, hornblende, and pyroxene. A compositional range obtained of blocks and enclaves resulted from mixing between andesite (866 °C ± 22) and basaltic andesite (enclaves, 932 °C ± 22), which may have triggered the explosive Pelean eruption. Vestiges of that mixing are preserved as complex compositional zones in plagioclase and clinopyroxene-rich reaction rims in amphibole in the andesite. Whole-rock chemistry, geothermometry, experimental petrology and modeling results suggest that after the mixing event the eruption tapped hybrid andesitic magma (≤ 900 °C) and ended with effusive dacitic magma (~ 825 °C), all of which were stored at ~ 200 MPa water pressure. A complex open-system evolution that involved crustal end-members best explains the generation of effusive dacite from the hybrid andesite. Amphibole in the dacite is rimmed by reaction products of plagioclase, orthopyroxene, and Fe-Ti oxides produced by decompression during ascent. Amphibole in the andesite

  19. 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…

  20. 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

  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. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 78 FR 1246 - Otay River Estuary Restoration Project; South San Diego Bay Unit and Sweetwater Marsh Unit of the...

    Science.gov (United States)

    2013-01-08

    ...-FF08RSDC00] Otay River Estuary Restoration Project; South San Diego Bay Unit and Sweetwater Marsh Unit of the... scoping with regard to the environmental impact statement (EIS) for the proposed Otay River Estuary... one of the following methods. Email: [email protected] . Please include ``Otay Estuary NOI'' in the...

  17. 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...

  18. 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.

  19. 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...

  20. 33 CFR 334.1160 - San Pablo Bay, Calif.; target practice area, Mare Island Naval Shipyard, Vallejo.

    Science.gov (United States)

    2010-07-01

    ... practice area, Mare Island Naval Shipyard, Vallejo. 334.1160 Section 334.1160 Navigation and Navigable... REGULATIONS § 334.1160 San Pablo Bay, Calif.; target practice area, Mare Island Naval Shipyard, Vallejo. (a..., Mare Island Naval Shipyard, Vallejo, California, will conduct target practice in the area at intervals...

  1. 33 CFR 334.1170 - San Pablo Bay, Calif.; gunnery range, Naval Inshore Operations Training Center, Mare Island...

    Science.gov (United States)

    2010-07-01

    ... range, Naval Inshore Operations Training Center, Mare Island, Vallejo. 334.1170 Section 334.1170... Operations Training Center, Mare Island, Vallejo. (a) The Danger Zone. A sector in San Pablo Bay delineated..., Vallejo, California, will conduct gunnery practice in the area during the period April 1 through September...

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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.

  8. Macrobenthic community response to copper in Shelter Island Yacht Basin, San Diego Bay, California.

    Science.gov (United States)

    Neira, Carlos; Mendoza, Guillermo; Levin, Lisa A; Zirino, Alberto; Delgadillo-Hinojosa, Francisco; Porrachia, Magali; Deheyn, Dimitri D

    2011-04-01

    We examined Cu contamination effects on macrobenthic communities and Cu concentration in invertebrates within Shelter Island Yacht Basin, San Diego Bay, California. Results indicate that at some sites, Cu in sediment has exceeded a threshold for "self defense" mechanisms and highlight the potential negative impacts on benthic faunal communities where Cu accumulates and persists in sediments. At sites with elevated Cu levels in sediment, macrobenthic communities were not only less diverse but also their total biomass and body size (individual biomass) were reduced compared to sites with lower Cu. Cu concentration in tissue varied between species and within the same species, reflecting differing abilities to "regulate" their body load. The spatial complexity of Cu effects in a small marina such as SIYB emphasizes that sediment-quality criteria based solely on laboratory experiments should be used with caution, as they do not necessarily reflect the condition at the community and ecosystem levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Polychlorinated biphenyls (PCBs) in recreational marina sediments of San Diego Bay, southern California.

    Science.gov (United States)

    Neira, Carlos; Vales, Melissa; Mendoza, Guillermo; Hoh, Eunha; Levin, Lisa A

    2018-01-01

    Polychlorinated biphenyl (PCB) concentrations were determined in surface sediments from three recreational marinas in San Diego Bay, California. Total PCB concentrations ranged from 23 to 153, 31-294, and 151-1387ngg -1 for Shelter Island Yacht Basin (SIYB), Harbor Island West (HW) and Harbor Island East (HE), respectively. PCB concentrations were significantly higher in HE and PCB group composition differed relative to HW and SIYB, which were not significantly different from each other in concentration or group composition. In marina sediments there was a predominance (82-85%) of heavier molecular weight PCBs with homologous groups (6CL-7CL) comprising 59% of the total. In HE 75% of the sites exceeded the effect range median (ERM), and toxicity equivalence (TEQ dioxin-like PCBs) values were higher relative to those of HW and SIYB, suggesting a potential ecotoxicological risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. 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

  11. Bed composition generation for morphodynamic modeling: Case study of San Pablo Bay in California, USA

    Science.gov (United States)

    van der Wegen, M.; Dastgheib, A.; Jaffe, B.E.; Roelvink, D.

    2011-01-01

    Applications of process-based morphodynamic models are often constrained by limited availability of data on bed composition, which may have a considerable impact on the modeled morphodynamic development. One may even distinguish a period of "morphodynamic spin-up" in which the model generates the bed level according to some ill-defined initial bed composition rather than describing the realistic behavior of the system. The present paper proposes a methodology to generate bed composition of multiple sand and/or mud fractions that can act as the initial condition for the process-based numerical model Delft3D. The bed composition generation (BCG) run does not include bed level changes, but does permit the redistribution of multiple sediment fractions over the modeled domain. The model applies the concept of an active layer that may differ in sediment composition above an underlayer with fixed composition. In the case of a BCG run, the bed level is kept constant, whereas the bed composition can change. The approach is applied to San Pablo Bay in California, USA. Model results show that the BCG run reallocates sand and mud fractions over the model domain. Initially, a major sediment reallocation takes place, but development rates decrease in the longer term. Runs that take the outcome of a BCG run as a starting point lead to more gradual morphodynamic development. Sensitivity analysis shows the impact of variations in the morphological factor, the active layer thickness, and wind waves. An important but difficult to characterize criterion for a successful application of a BCG run is that it should not lead to a bed composition that fixes the bed so that it dominates the "natural" morphodynamic development of the system. Future research will focus on a decadal morphodynamic hindcast and comparison with measured bathymetries in San Pablo Bay so that the proposed methodology can be tested and optimized. ?? 2010 The Author(s).

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. Problems and constraints in Philippine municipal fisheries: The case of San Miguel Bay, Camarines Sur

    Science.gov (United States)

    Lim, Cristina P.; Matsuda, Yoshiaki; Shigemi, Yukio

    1995-11-01

    The Philippine fisheries accounted for 3.7% of the gross national product at current prices. The sector employed about 990,872 persons. Of the divisions comprising the industry, municipal fisheries continued to contribute the largest share of fish production. However, the sector is beset with problems, many of which are best examplified by the case of San Miguel Bay (SMB). This paper presents the problems and constraints confronting SMB, a common property resource. This bay's open access condition has led to various problems, such as declining fishery resources, depressed socioeconomic conditions, illegal fishing, increasing population, and conflict among resource users. A poor marketing system, low level of fishing technology, fishermen's noncompliance and authorities' lax enforcement of rules and regulations, as well as lack of alternative sources of income further characterize the condition in SMB. Establishment of fishing rights, improvement of the marketing system, provision of alternative sources of income, and improvement of fishing technology were some of the solutions suggested. One major constraint, however, is financial, Comanagement complemented with other management tools has been proposed in addressing the problems in SMB.

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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...

  9. 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.

  10. 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.

  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. 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

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. Dissolved oxygen content as an index of water quality in San Vicente Bay, Chile (36 degrees 45'S).

    Science.gov (United States)

    Rudolph, Anny; Ahumada, Ramón; Pérez, Claudio

    2002-08-01

    The present report describes some effects of industrial and municipal effluents on the waters of San Vicente Bay. Analyses of the main substances contained in the fishing industry effluent suggest rating criteria based on the oxygen saturation of the water as an assessment of organic pollution. Six cruises were carried out throughout the Bay, from June to December 1996. Water samples were analyzed for dissolved oxygen, oil and grease content, and sediment samples for organic matter content. Water parameters (salinity, temperature) were used to characterize the Bay's hydrography, and to calculate values for oxygen saturation. The measurements demonstrated a local broad range of oxygen deficit, with a maximum of 45% in the winter to 95% in the spring. In November more than 65% of the Bay's area showed oxygen deficits greater than 40%. Organic matter was unusually high in sediments along the northern sector of the Bay. The results suggest that the oxygen depletion was a representative parameter for establishing a relative scale of water quality in this Bay.

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. Macrofaunal recolonization of copper-contaminated sediments in San Diego Bay.

    Science.gov (United States)

    Neira, Carlos; Mendoza, Guillermo; Porrachia, Magali; Stransky, Chris; Levin, Lisa A

    2015-12-30

    Effects of Cu-loading on macrofaunal recolonization were examined in Shelter Island Yacht Basin (San Diego Bay, California). Sediments with high and low Cu levels were defaunated and Cu-spiked, translocated, and then placed back into the environment. These demonstrated that the alteration observed in benthic communities associated with Cu contamination occurs during initial recolonization. After a 3-month exposure to sediments with varying Cu levels, two primary colonizing communities were identified: (1) a "mouth assemblage" resembling adjacent background fauna associated with low-Cu levels that was more diverse and predominantly dominated by surface- and subsurface-deposit feeders, burrowers, and tube builders, and (2) a "head assemblage" resembling adjacent background fauna associated with high-Cu concentrations, with few dominant species and an increasing importance of carnivores and mobile epifauna. Cu loading can cause reduced biodiversity and lower structural complexity that may last several months if high concentrations persist, with a direct effect on community functioning. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. 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.

  4. 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.

  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. 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

  7. 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.

  8. 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

  9. Investigating the fate of microplastics in the San Diego Bay area: A paleoenvironmental approach

    Science.gov (United States)

    Fontaine, R. M.; Hangsterfer, A.; Bhattacharya, A.

    2017-12-01

    Microplastics in marine waste surveys compare the observed amount of microplastic debris in the ocean with constructed models to determine availability of microplastics in the ocean. However, most of these studies have been constrained in the surface ocean and the surveys have found a substantial difference between estimated and observed amount of microplastic in the ocean. One possible reason could be that microplastics are settling along continental shelves or the ocean bottom. Via this research we have collected samples to study marine sediments (collected from increasing depth along the continental shelf around San Diego) for microplastics. Our goal is to determine the relationship between density and microplastic distribution. The main objective is to investigate sinks of microplastic (plastic products sizes less than 1 mm) along continental shelves; more specifically, this small study aims to investigate (a) what are the dominant types of microplastics (for example, heavy plastic or light plastic), (b) shapes of microplastics derived from commonly used heavy and light plastics, (c) is there specific locations (for example floating in water column vs. settling ocean floor along the continental shelves, which would be the first places where one might expect microplastics (that are delivered via river systems or from beaches) typically and finally, (d) is there any marine environmental preference between light and heavy microplastics. In this study, we provide observational evidence about the poorly understood fate of microplastics in the ocean as well as lend itself to the question: if and how long microplastics remain bioavailable. We have targeted four marine environments along San Diego that encompass several important connections between land and the ocean:Bays, river mouth, upwelling region and shelf. At each site listed above, we take four sets of 1-2ft cores: 20ft , 40ft, 60ft, 80ft. We combine traditional measurements (pH, salinity, density, DOC, N, P

  10. Shipborne Magnetic Survey of San Pablo Bay and Implications on the Hayward-Rodgers Creek Fault Junction

    Science.gov (United States)

    Ponce, D. A.; Athens, N. D.; Denton, K.

    2012-12-01

    A shipborne magnetic survey of San Pablo Bay reveals a steep magnetic gradient as well as several prominent magnetic anomalies along the offshore extension of the Hayward Fault. The Hayward Fault enters San Pablo Bay at Pinole Point and potentially extends beneath San Pablo Bay for 15 km. About 1,000 line-km of shipborne magnetometer data were collected in San Pablo Bay along approximately north-east and north-west trending traverses. Shiptrack lines were spaced 200-m apart in a N55oE direction and tie-lines were spaced 500- and 1,000-m apart in a N145oE direction. Magnetometer and Geographic Positioning System (GPS) data were collected simultaneously at one-second intervals using a Geometrics G858 cesium vapor magnetometer with the sensor attached to a nonmagnetic pole extended about 2 m over the bow. Diurnal variations of the Earth's magnetic field were recorded at a ground magnetic base station and shipborne data were corrected for diurnal variations, International Geomagnetic Reference Field, cultural noise, heading errors, and leveling errors. The heading correction applied to the shipborne magnetic data accounts for a systematic shift in the magnetic readings due to the magnetic field produced by the boat and the orientation of the boat. The heading correction was determined by traversing several shiptrack lines in various azimuths in opposite directions. Magnetic measurements off the main survey lines (e.g., turns) were removed from the survey. After applying the heading correction, crossing values or the difference in values where two survey lines intersect were compared and the survey was leveled. Shipborne magnetic data reveal a prominent magnetic anomaly immediately offshore of Point Pinole that probably reflects ultramafic rocks (e.g. serpentinite), similar to those exposed in the northern part of the onshore Hayward Fault. Further to the northwest, shipborne magnetic data enhance two prominent aeromagnetic anomalies along the Hayward Fault in the

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. 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

  16. Specialty education in periodontics in Japan and the United States: comparison of programs at Nippon Dental University Hospital and the University of Texas Health Science Center at San Antonio.

    Science.gov (United States)

    Osawa, Ginko; Nakaya, Hiroshi; Mealey, Brian L; Kalkwarf, Kenneth; Cochran, David L

    2014-03-01

    Japan has institutions that train qualified postdoctoral students in the field of periodontics; however, Japan does not have comprehensive advanced periodontal programs and national standards for these specialty programs. To help Japanese programs move toward global standards in this area, this study was designed to describe overall differences in periodontics specialty education in Japan and the United States and to compare periodontics faculty members and residents' characteristics and attitudes in two specific programs, one in each country. Periodontal faculty members and residents at Nippon Dental University (NDU) and the University of Texas Health Science Center at San Antonio (UTHSCSA) Dental School participated in the survey study: four faculty members and nine residents at NDU; seven faculty members and thirteen residents at UTHSCSA. Demographic data were collected as well as respondents' attitudes toward and assessment of their programs. The results showed many differences in curriculum structure and clinical performance. In contrast to the UTHSCSA respondents, for example, the residents and faculty members at NDU reported that they did not have enough subject matter and time to learn clinical science. Although the residents at NDU reported seeing more total patients in one month than those at UTHSCSA, they were taught fewer varieties of periodontal treatments. To provide high-quality and consistent education for periodontal residents, Japan needs to establish a set of standards that will have positive consequences for those in Japan who need periodontal treatment.

  17. The business and technical case for Continuous Commissioning(reg Trade Mark) for enhanced building operations. A case study: Alamo Community College District San Antonio, Texas, U.S.A

    Energy Technology Data Exchange (ETDEWEB)

    Verdict, Malcolm; Wei, Guanghua [Texas A and M Univ. System, College Station, TX (United States). Energy Systems Laboratory

    2005-07-01

    This paper provides both the business and technical cases for the 'Continuous Commissioning' of large [>25,000 square feet], buildings through a whole building diagnostic and HVAC optimization approach known as 'Continuous Commissioning'. 'Continuous Commissioning' is defined as the ongoing engineering process to resolve operating problems, improve comfort, optimize energy use and identify retrofits in existing buildings and central plant facilities. It is also known as 'building retro-commissioning' or 'building tune-up'. It involves a rigorous, whole-building, engineering evaluation of the heating and cooling systems to identify mechanical problems, inadequate or ineffective control strategies. Some of the most common problems are: 1) Improper calibration of sensors and metering, 2) inadequate control strategies for optimum operation and comfort, 3) incorrect scheduling of heating and cooling equipment, 4) lack of air and water-side economizer equipment, 5) inadequate building automation systems, and 6) inadequate operations and maintenance. The CC process, described in this paper, was successfully applied at Alamo Community College District (ACCD) in San Antonio, Texas, USA by the Energy Systems Laboratory (ESL), a part of the Texas A and M Univ. System. ACCD has multiple buildings on 4 campuses with total conditioned area of 2.35 Million square feet. ACCD's business approach was unique because the cost of conducting the CC process was financed as an Energy Cost Reduction Measure (ECRM) along with several energy efficiency retrofits.

  18. Influencia de los patrones de uso actual de la tierra sobre la dinámica de la vegetación en el páramo de Rabanal, vereda San Antonio, municipio de Guachetá

    Directory of Open Access Journals (Sweden)

    Luis Miguel Borrás S.

    2010-10-01

    Full Text Available The patterns of current land use in the Rabanal paramo suggest a slow and progressive deterioration of the vegetation of this ecosystem, probably due to the current practice of disturbances imposed apparently largely by human causes, mainly the expansion of the agricultural frontier (mechanized potato crops and grazing. The typical situation of the pattern of occupation and land-holding in these places, as well as the established production system, is the starting point to determine its effect on this sector of the Rabanal paramo ecosystem and define whether or not this fact is crucial to its conservation and management.The study was conducted in three stages that included the characterization of the area done through surveys, a review of primary and secondary education, followed by field work, and final tabulation of information.The present study obtained results which were intended to contribute to the knowledge of current land use in a sector of the settlement of San Antonio - Township Guachetá, bordering the Rabanal Paramo and with this give the necessary foundation for understanding how anthropogenic intervention operates in the area and its implications for vegetation dynamics and knowledge of its production systems.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. Geochemical evolution processes and water-quality observations based on results of the National Water-Quality Assessment Program in the San Antonio segment of the Edwards aquifer, 1996-2006

    Science.gov (United States)

    Musgrove, MaryLynn; Fahlquist, Lynne; Houston, Natalie A.; Lindgren, Richard J.; Ging, Patricia B.

    2010-01-01

    As part of the National Water-Quality Assessment Program, the U.S. Geological Survey collected and analyzed groundwater samples during 1996-2006 from the San Antonio segment of the Edwards aquifer of central Texas, a productive karst aquifer developed in Cretaceous-age carbonate rocks. These National Water-Quality Assessment Program studies provide an extensive dataset of groundwater geochemistry and water quality, consisting of 249 groundwater samples collected from 136 sites (wells and springs), including (1) wells completed in the shallow, unconfined, and urbanized part of the aquifer in the vicinity of San Antonio (shallow/urban unconfined category), (2) wells completed in the unconfined (outcrop area) part of the regional aquifer (unconfined category), and (3) wells completed in and springs discharging from the confined part of the regional aquifer (confined category). This report evaluates these data to assess geochemical evolution processes, including local- and regional-scale processes controlling groundwater geochemistry, and to make water-quality observations pertaining to sources and distribution of natural constituents and anthropogenic contaminants, the relation between geochemistry and hydrologic conditions, and groundwater age tracers and travel time. Implications for monitoring water-quality trends in karst are also discussed. Geochemical and isotopic data are useful tracers of recharge, groundwater flow, fluid mixing, and water-rock interaction processes that affect water quality. Sources of dissolved constituents to Edwards aquifer groundwater include dissolution of and geochemical interaction with overlying soils and calcite and dolomite minerals that compose the aquifer. Geochemical tracers such as magnesium to calcium and strontium to calcium ratios and strontium isotope compositions are used to evaluate and constrain progressive fluid-evolution processes. Molar ratios of magnesium to calcium and strontium to calcium in groundwater typically

  10. California Counties and San Francisco Bay Area Watershed Boundaries, California, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data layers represent CA counties and the Bay Area Watersheds. These data layers aid in identifying counties and watersheds where the grant projects occur.

  11. 33 CFR 334.670 - Gulf of Mexico south and west of Apalachicola, San Blas, and St. Joseph bays; air-to-air firing...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Gulf of Mexico south and west of Apalachicola, San Blas, and St. Joseph bays; air-to-air firing practice range, Tyndall Air Force Base, Fla. 334..., DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.670 Gulf of Mexico south and west of...

  12. 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

  13. Hydrogeology and geochemistry of aquifers underlying the San Lorenzo and San Leandro areas of the East Bay Plain, Alameda County, California

    Science.gov (United States)

    Izbicki, John A.; Borchers, James W.; Leighton, David A.; Kulongoski, Justin T.; Fields, Latoya; Galloway, Devin L.; Michel, Robert L.

    2003-01-01

    The East Bay Plain, on the densely populated eastern shore of San Francisco Bay, contains an upper aquifer system to depths of 250 feet below land surface and an underlying lower aquifer system to depths of more than 650 feet. Injection and recovery of imported water has been proposed for deep aquifers at two sites within the lower aquifer system. Successful operation requires that the injected water be isolated from surface sources of poor-quality water during storage and recovery. Hydraulic, geochemical, and isotopic data were used to evaluate the isolation of deeper aquifers. Ground-water responses to tidal changes in the Bay suggest that thick clay layers present within these deposits effectively isolate the deeper aquifers in the northern part of the study area from overlying surficial deposits. These data also suggest that the areal extent of the shallow and deep aquifers beneath the Bay may be limited in the northern part of the study area. Despite its apparent hydraulic isolation, the lower aquifer system may be connected to the overlying upper aquifer system through the corroded and failed casings of abandoned wells. Water-level measurements in observation wells and downward flow measured in selected wells during nonpumped conditions suggest that water may flow through wells from the upper aquifer system into the lower aquifer system during nonpumped conditions. The chemistry of water from wells in the East Bay Plain ranges from fresh to saline; salinity is greater than seawater in shallow estuarine deposits near the Bay. Water from wells completed in the lower aquifer system has higher pH, higher sodium, chloride, and manganese concentrations, and lower calcium concentrations and alkalinity than does water from wells completed in the overlying upper aquifer system. Ground-water recharge temperatures derived from noble-gas data indicate that highly focused recharge processes from infiltration of winter streamflow and more diffuse recharge processes from

  14. 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.

  15. 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.

  16. 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

  17. Calidad de los Servicios Académicos y Administrativos de la Facultad de Ciencias Sociales de la Universidad Nacional de San Antonio Abad del Cusco, Según la Percepción del Personal docente y estudiantes, Año 2015

    OpenAIRE

    Vargas Béjar, Juan Fernando

    2017-01-01

    La calidad de los servicios académicos y administrativos de la Facultad de Ciencias Sociales de la Universidad Nacional de San Antonio Abad del Cusco (UNSAAC), es un tema que será visto desde el enfoque de los docentes y estudiantes quienes brindan la información necesaria para poder comprender la estructura de dichos servicios y si éstos son utilizados coherentemente. Las actividades dentro de la mencionada Facultad, representan el ámbito académico y administrativo para el adecuado desemp...

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 75 FR 32209 - North San Pablo Bay Restoration and Reuse Project

    Science.gov (United States)

    2010-06-07

    ... promote the expanded beneficial use of recycled water in the North Bay region. In this way, water demand... XVI of Public Law 102-575, as amended, which provides a mechanism for Federal participation and cost... Napa counties are facing long-term water supply shortfalls. Surface and groundwater supplies within...

  3. 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

  4. 33 CFR 165.1151 - Security Zones; liquefied hazardous gas tank vessels, San Pedro Bay, California.

    Science.gov (United States)

    2010-07-01

    ... a tank vessel as liquefied petroleum gas, liquefied natural gas, or similar liquefied gas products... Eleventh Coast Guard District § 165.1151 Security Zones; liquefied hazardous gas tank vessels, San Pedro... the sea floor, within a 500 yard radius around any liquefied hazardous gas (LHG) tank vessel that is...

  5. Process-based, morphodynamic hindcast of decadal deposition (1856-1887) and erosion (1951-1983) patterns in San Pablo Bay, California

    Science.gov (United States)

    Wegen, M. V.; Jaffe, B. E.; Roelvink, J.

    2009-12-01

    The objective of the current research is to hindcast decadal morphodynamic development in San Pablo Bay, California, USA using a process-based, numerical model, Delft3D. Experience gained in the current research will be ultimately used to model future morphodynamic changes in San Pablo Bay under different scenarios of climate change. Delft3D is run in 3D mode including wind waves, salt and fresh water interaction, sand and mud fractions and applies a sophisticated morphodynamic update scheme [Roelvink (2006)]. Model outcomes are evaluated against measured bathymetric developments [Cappiella (1999), Jaffe et al (2007)] and include an extensive sensitivity analysis on model parameter settings. In the 19th century more than 250 million cubic meters of sediment was deposited in San Pablo Bay because of the increased sediment load associated with hydraulic gold mining activities. When mining stopped and dam construction regulated river flows and trapped sediment upstream early 20th century, San Pablo Bay showed an eroding trend. Focus of the hindcast is on the 1856 to 1887 depositional period and on the 1951 to 1983 erosional period. The results of the model heavily depend on parameter settings related to sediment transport, bed composition and boundary conditions schematization. A major handicap is that the (historic) values of these parameters are not known in detail. Recommendations by Ganju et al. (2008) are used to overcome this problem. The results show, however, that applying best-guess model parameter settings can predict decadal morphodynamic developments reasonably well in San Pablo Bay. From all varied settings sediment concentration, river discharge and waves have the most significant effect on deposition volumes, whereas waves have the most impact on sediment distribution within San Pablo Bay. For the depositional period Brier Skill Scores have values around 0.25 with a maximum of 0.43 (qualified as ‘good’) although higher values (up to 0.65) were

  6. Antonio Lupi maailm

    Index Scriptorium Estoniae

    2008-01-01

    Vannitoa mööbli, peeglite, vannide, kraanikausside ja aksessuaaride valmistamisele spetsialiseerunud Antonio Lupi tehasest Itaalias. Koostööd tehakse itaalia disaineritega, nagu Carlo Colombo, Mauro Carlesi, Nevio Tellatin, Anne ja Patrick Poirier. Eestis saab tootenäidistega tutvuda salongis Gerhard Vannitoad (Maakri 19/21, Tallinn)

  7. 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

  8. 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

  9. 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.

  10. 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

  11. 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

  12. 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...

  13. San Antonio's 1983 Bus Passenger Survey

    Science.gov (United States)

    1983-10-01

    Many transit operators routinely collect ridership data in order to provide a : basis for the planning of bus services. Often a survey is conducted of bus : riders to determine their riding habits, their views about the quality of : current service, ...

  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. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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.

  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. Effects of the Blob on settlement of spotted sand bass, Paralabrax maculatofasciatus, to Mission Bay, San Diego, CA.

    Science.gov (United States)

    Basilio, Anthony; Searcy, Steven; Thompson, Andrew R

    2017-01-01

    The West Coast of the United States experienced variable and sometimes highly unusual oceanographic conditions between 2012 and 2015. In particular, a warm mass of surface water known as the Pacific Warm Anomaly (popularly as "The Blob") impinged on southern California in 2014, and warm-water conditions remained during the 2015 El Niño. We examine how this oceanographic variability affected delivery and individual characteristics of larval spotted sand bass (Paralabrax maculatofasciatus) to an estuarine nursery habitat in southern California. To quantify P. maculatofasciatus settlement patterns, three larval collectors were installed near the mouth of Mission Bay, San Diego CA, and retrieved weekly from June-October of 2012-2015. During 'Blob' conditions in 2014 and 2015, lower settlement rates of spotted sand bass were associated with higher sea surface temperature and lower wind speed, chlorophyll a (chl a) and upwelling. Overall, the number of settlers per day peaked at intermediate chl a values across weeks. Individual characteristics of larvae that settled in 2014-2015 were consistent with a poor feeding environment. Although settlers were longer in length in 2014-15, fish in these years had slower larval otolith growth, a longer larval duration, and a trend towards lower condition, traits that are often associated with lower survival and recruitment. This study suggests that future settlement and recruitment of P. maculatofasciatus and other fishes with similar life histories may be adversely affected in southern California if ocean temperatures continue to rise in the face of climate change.

  11. Effects of the Blob on settlement of spotted sand bass, Paralabrax maculatofasciatus, to Mission Bay, San Diego, CA.

    Directory of Open Access Journals (Sweden)

    Anthony Basilio

    Full Text Available The West Coast of the United States experienced variable and sometimes highly unusual oceanographic conditions between 2012 and 2015. In particular, a warm mass of surface water known as the Pacific Warm Anomaly (popularly as "The Blob" impinged on southern California in 2014, and warm-water conditions remained during the 2015 El Niño. We examine how this oceanographic variability affected delivery and individual characteristics of larval spotted sand bass (Paralabrax maculatofasciatus to an estuarine nursery habitat in southern California. To quantify P. maculatofasciatus settlement patterns, three larval collectors were installed near the mouth of Mission Bay, San Diego CA, and retrieved weekly from June-October of 2012-2015. During 'Blob' conditions in 2014 and 2015, lower settlement rates of spotted sand bass were associated with higher sea surface temperature and lower wind speed, chlorophyll a (chl a and upwelling. Overall, the number of settlers per day peaked at intermediate chl a values across weeks. Individual characteristics of larvae that settled in 2014-2015 were consistent with a poor feeding environment. Although settlers were longer in length in 2014-15, fish in these years had slower larval otolith growth, a longer larval duration, and a trend towards lower condition, traits that are often associated with lower survival and recruitment. This study suggests that future settlement and recruitment of P. maculatofasciatus and other fishes with similar life histories may be adversely affected in southern California if ocean temperatures continue to rise in the face of climate change.

  12. 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.

  13. Water-quality observations of the San Antonio segment of the Edwards aquifer, Texas, with an emphasis on processes influencing nutrient and pesticide geochemistry and factors affecting aquifer vulnerability, 2010–16

    Science.gov (United States)

    Opsahl, Stephen P.; Musgrove, MaryLynn; Mahler, Barbara J.; Lambert, Rebecca B.

    2018-06-07

    As questions regarding the influence of increasing urbanization on water quality in the Edwards aquifer are raised, a better understanding of the sources, fate, and transport of compounds of concern in the aquifer—in particular, nutrients and pesticides—is needed to improve water management decision-making capabilities. The U.S. Geological Survey, in cooperation with the San Antonio Water System, performed a study from 2010 to 2016 to better understand how water quality changes under a range of hydrologic conditions and in contrasting land-cover settings (rural and urban) in the Edwards aquifer. The study design included continuous hydrologic monitoring, continuous water-quality monitoring, and discrete sample collection for a detailed characterization of water quality at a network of sites throughout the aquifer system. The sites were selected to encompass a “source-to-sink” (that is, from aquifer recharge to aquifer discharge) approach. Network sites were selected to characterize rainfall, recharging surface water, and groundwater; groundwater sites included wells in the unconfined part of the aquifer (unconfined wells) and in the confined part of the aquifer (confined wells) and a major discharging spring. Storm-related samples—including rainfall samples, stormwater-runoff (surface-water) samples, and groundwater samples—were collected to characterize the aquifer response to recharge.Elevated nitrate concentrations relative to national background values and the widespread detection of pesticides indicate that the Edwards aquifer is vulnerable to contamination and that vulnerability is affected by factors such as land cover, aquifer hydrogeology, and changes in hydrologic conditions. Greater vulnerability of groundwater in urban areas relative to rural areas was evident from results for urban groundwater sites, which generally had higher nitrate concentrations, elevated δ15N-nitrate values, a greater diversity of pesticides, and higher pesticide

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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

  16. 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

  17. 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

  18. 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.

  19. Entrevista com Antonio Candido

    Directory of Open Access Journals (Sweden)

    Pontes Heloisa

    2001-01-01

    Full Text Available Concedida em agosto de 1987, revista pelo autor em julho de 2001, esta entrevista aborda dimensões relevantes da trajetória intelectual de Antonio Candido. Por meio do rastreamento do impacto da revolução de 1930 na cultura brasileira e do papel decisivo que a fundação da Faculdade de Filosofia da Universidade de São Paulo teve na implantação de um novo padrão de trabalho intelectual, Antonio Candido arma o contexto necessário para entendermos os desafios culturais e políticos perseguidos por ele e por figuras de ponta de sua geração, como Florestan Fernandes e vários dos integrantes do Grupo Clima. O resultado é uma imagem vívida e palpitante do caldo de cultura que permeou o processo de institucionalização das Ciências Sociais em São Paulo.

  20. 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 (...

  1. Aplicación de canciones infantiles y su influencia en el aprendizaje del vocabulario del idioma francés en los niños del nivel inicial de la Institución Educativa San Antonio de Padua, Chosica - Lima 2016

    OpenAIRE

    Gómez Hermoza, Cecilia del Pilar

    2017-01-01

    Aplica las canciones infantiles en el aprendizaje del vocabulario del idioma francés en los niños del nivel inicial de la Institución Educativa San Antonio de Padua Chosica - Lima 2016. Se realiza un estudio cuasi experimental en el cual participan dos grupos, uno de 24 niños de 5 años del aula “A”, que constituyó el grupo de control y el otro, con 24 niños de 5 años del aula “B”, que conformó el cuasi experimental; se utilizan estrategias para el aprendizaje práctico asistido por la profesor...

  2. 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.

  3. Urban Greening Bay Area

    Science.gov (United States)

    Information about the San Francisco Bay Water Quality Project (SFBWQP) Urban Greening Bay Area, a large-scale effort to re-envision urban landscapes to include green infrastructure (GI) making communities more livable and reducing stormwater runoff.

  4. 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

  5. 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

  6. Cross-shelf transport into nearshore waters due to shoaling internal tides in San Pedro Bay, CA

    Science.gov (United States)

    Noble, Marlene A.; Burt Jones,; Peter Hamilton,; Xu, Jingping; George Robertson,; Rosenfeld, Leslie; John Largier,

    2009-01-01

    In the summer of 2001, a coastal ocean measurement program in the southeastern portion of San Pedro Bay, CA, was designed and carried out. One aim of the program was to determine the strength and effectiveness of local cross-shelf transport processes. A particular objective was to assess the ability of semidiurnal internal tidal currents to move suspended material a net distance across the shelf. Hence, a dense array of moorings was deployed across the shelf to monitor the transport patterns associated with fluctuations in currents, temperature and salinity. An associated hydrographic program periodically monitored synoptic changes in the spatial patterns of temperature, salinity, nutrients and bacteria. This set of measurements show that a series of energetic internal tides can, but do not always, transport subthermocline water, dissolved and suspended material from the middle of the shelf into the surfzone. Effective cross-shelf transport occurs only when (1) internal tides at the shelf break are strong and (2) subtidal currents flow strongly downcoast. The subtidal downcoast flow causes isotherms to tilt upward toward the coast, which allows energetic, nonlinear internal tidal currents to carry subthermocline waters into the surfzone. During these events, which may last for several days, the transported water remains in the surfzone until the internal tidal current pulses and/or the downcoast subtidal currents disappear. This nonlinear internal tide cross-shelf transport process was capable of carrying water and the associated suspended or dissolved material from the mid-shelf into the surfzone, but there were no observation of transport from the shelf break into the surfzone. Dissolved nutrients and suspended particulates (such as phytoplankton) transported from the mid-shelf into the nearshore region by nonlinear internal tides may contribute to nearshore algal blooms, including harmful algal blooms that occur off local beaches.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  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. 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

  14. 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...

  15. 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

  16. Antonio Mollari fra Canova e Valadier / Antonio Mollari between Canova and Valadier

    Directory of Open Access Journals (Sweden)

    Elisa Debenedetti

    2014-04-01

    Full Text Available Non è difficile inserire Antonio Mollari in un contesto europeo. Ad Antonio Canova lo lega una prima, importantissima lettera del 4 maggio 1807 nella quale, in seguito ad un invito trasmessogli dallo scultore, ma di cui è responsabile Filippo III Colonna, enumera tutte le sue opere; la seconda risale al 25 febbraio 1809. Dalla prima missiva si riescono a stabilire numerosi contatti con Giuseppe Valadier: a Corridonia (Collegiata dei Santi Pietro, Paolo e Donato; Ospedale e Chiesa di San Salvatore e a Macerata (Palazzo Conti già Ugolini. Tanto da giungere a considerare Mollari come il continuatore del Valadier nei cantieri marchigiani, dove la presenza del Maestro si manifesta come una sovrapposizione di motivi francesizzanti a soluzioni palladiane: componenti entrambe presenti nel Palazzo Tomassini a Corridonia, ricondotto al Maceratese. Fra l’altro le pagine di due Taccuini valadieriani, certo a lui note, si possono considerare a metà strada fra l’esercizio tipologico ed il modello. It’s not difficult to insert Antonio Mollari into a European context. A first very important letter, dated May 4th 1807, links him to Antonio Canova whereby, after inviting him, by wish of Phillip Colonna III , he then makes a list of all his works of art; the second is dated February 25th 1809. Various contacts with Giuseppe Valadier can be established from the first letter: in Corridonia (Saints Peter, Paul and Donato Collegiate church; St. Saviour’s Hospital and Church and in Macerata (Conti Palace ex Ugolini. So much so as to regard Mollari as Valadier’s continuator in the Marche construction sites, where the Maestro’s presence is expressed like a superimposition of Frenchified motives for Palladian solutions: both components being present in the Tomassini Palace in Corridonia, which can be traced back to Mollari. Moreover the pages of two Valdier Notebooks, which he must have known about, can be considered half way between a typological exercise

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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...

  6. 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…

  7. 75 FR 38412 - Safety Zone; San Diego POPS Fireworks, San Diego, CA

    Science.gov (United States)

    2010-07-02

    ...-AA00 Safety Zone; San Diego POPS Fireworks, San Diego, CA AGENCY: Coast Guard, DHS. ACTION: Temporary... waters of San Diego Bay in support of the San Diego POPS Fireworks. This safety zone is necessary to... San Diego POPS Fireworks, which will include fireworks presentations conducted from a barge in San...

  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. 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.

  10. 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.

  11. 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.

  12. Abetti, Antonio (1846-1928) and Abetti, Giorgio (1882-1982)

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    Antonio was born in San Pietro di Gorizia, Italy. A civil engineer, he turned to astronomy and became director of the observatory in Arcetri and professor of astronomy at the University of Florence. His main interest was positional astronomy, observation of minor planets, comets and star occultations. In 1874 he observed the transit of Venus across the Sun's disk through a spectroscope. His son, ...

  13. 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

  14. 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.

  15. 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.

  16. Carbon storage and greenhouse gas fluxes in the San Juan Bay Estuary: Current trends and likely future states.

    Science.gov (United States)

    Mangrove systems are known carbon (C) and greenhouse gas (GHG) sinks, but this function may be affected by global change drivers that include (but are not limited to) eutrophication, climate change, species composition shifts, and hydrological changes. In Puerto Rico’s San...

  17. 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).

  18. 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

  19. 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

  20. Antonio Sánchez-Bayón, Sistema de Derecho Comparado y global: de las familias jurídicas mundiales al nuevo Derecho común, Tirant lo Blanch, Valencia, 2012, 161 págs.

    Directory of Open Access Journals (Sweden)

    Natalia del Barrio

    2013-03-01

    Full Text Available Dr. Sánchez-Bayón untersucht in dieser Studie die Notwendigkeit, das Konzept des Vergleichenden Rechts in Zeiten der Globalisierung neu zu überdenken. Die kulturellen, politischen und soziologischen Wechsel müssen an die neue Weltlage angepasst werden. Die juristischen Lösungen müssen verglichen werden, so dass die Spielregeln und der professionelle technische Sprachgebrauch angeglichen werden können; nur so können die Antworten auf die Konsolidierung des gemeinschaftlichen Rechts gefunden werden. Der Autor stellt den formalistischen Positivismus des Staates in Frage.

  1. 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

  2. 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...

  3. Effects of human disturbance on waterbird nesting and reproductive success at restoration pond SF2, south San Francisco Bay, California

    Science.gov (United States)

    Ackerman, Joshua T.; Herzog, Mark P.; Hartman, Christopher A.

    2014-01-01

    To offset for the loss of managed pond habitat during restoration of wetlands to tidal marsh, the South Bay Salt Pond (SBSP) Restoration Project is enhancing some of the remaining ponds by constructing islands for roosting and nesting waterbirds. Among these wetland habitats, the SBSP Restoration Project also is installing walking trails and viewing platforms in an effort to bring the public closer to nature. In winter of 2010–11, the SBSP Restoration Project constructed 30 islands in Pond SF2 and walking trails and viewing platforms around the edge of the pond. The restoration project partners acknowledged that human disturbance could detrimentally affect nesting and roosting waterbirds. Although optimal buffer distances and potential for human disturbance were unknown, islands in Pond SF2, nevertheless, were designed with built-in buffers of greater than 300 feet (91 meters) from a trail and 600 feet (182 meters) from a viewing platform in order to minimize potential human disturbances.

  4. 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.

  5. 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.

  6. 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.

  7. Sedimentation rates and trace metal input history in intertidal sediments from San Simon Bay (Ria de Vigo, NW Spain) derived from 210Pb and 137Cs chronology

    International Nuclear Information System (INIS)

    Alvarez-Iglesias, Paula; Quintana, Begona; Rubio, Belen; Perez-Arlucea, Marta

    2007-01-01

    210 Pb and 137 Cs dating methods, accompanied by a high-resolution geochemical study, were applied to intertidal sediments containing both fine and coarse-grained particles and also, anthropogenic Pb in order to establish sedimentation rates and historical trends in heavy metal input. Sedimentation rates were established according to the 'Constant Flux:Constant Sedimentation' (CF:CS) 210 Pb dating model, which was preferred rather than the 'Constant Rate of Supply-Minimum Variance' (CRS-MV) model. Variations in sediment grain-size were accounted for by application of several normalization procedures. Al was selected for grain-size correction. Corrected sedimentation rates obtained from 210 Pb dating were corroborated through a second independent radionuclide tracer and by comparison of peak trace metal inputs into the environment with peaks in the sediment. The Chernobyl maximum was identified in the normalized 137 Cs activity profile. Sedimentation rates of 6.2 ± 1.2 mm y -1 and 3.1 ± 0.5 mm y -1 for the upper (two muddy layers) and 6.0 ± 2.0 mm y -1 for the lower (sandy) intertidal mud flat deposits of San Simon Bay were determined. According to the established chronology, human-induced environmental changes were detected in total metal concentrations (Cu, Pb, Zn) and in sediment grain-size and composition

  8. 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.

  9. 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

  10. Fish community structure in San Agustín Bay, Huatulco, Mexico Estructura comunitaria de peces en bahía San Agustín, Huatulco, México

    Directory of Open Access Journals (Sweden)

    MARTÍN RAMÍREZ-GUTIÉRREZ

    2007-12-01

    Full Text Available San Agustín bay is one of the most important bays in the Huatulco National Park because it includes the broadest coral reef surface of this park, which supports a great diversity of fish species. The importance of the present work is that describes quantitatively, for first time, the fish assemblage of this reef area. Visual censuses were realized on transects, according to the coral reef size, on coral and rocky reefs, and coral rubble environments. 64 species, 46 genus and 29 families were registered. Seasonal variation in fish assemblage was observed; reflecting the influence of pelagic shoaling species associated with the Gulf of Tehuantepec upwelling, during the dry season. Thus species were Selar crumenophthalmus, Caranx caninus, and Sardinops caeruleus. For species more closely associated to the reef habitat little seasonal variation was observed for each species, except Chromis atrilobata, which exhibited high density during the dry season. Pomacentrids exhibited more affinity for coral reef, labrids and haemulids for coral rubble environments. The highest diversity values were on coral rubble and the highest density was on the coral reef. Our study suggests that in this region, the Gulf of Tehuantepec upwelling is an important factor as well as the heterogeneity of habitats in shaping the fish assemblages, which must be protected to maintain the biodiversity of this important ecosystemLa bahía de San Agustín es una de las más importantes del Parque Nacional Huatulco debido a que incluye al arrecife coralino más grande de este parque, el cual alberga una gran diversidad de especies de peces. La importancia del presente trabajo es describir cuantitativamente, por primera vez, la comunidad de peces de este habitat de arrecifes. Para ello se realizaron censos visuales en transectos de acuerdo al tamaño de los ambientes coralino, rocoso y de escombros. 64 especies, 46 géneros y 29 familias fueron registrados. Se observaron cambios

  11. Coordinating water conservation efforts through tradable credits: A proof of concept for drought response in the San Francisco Bay area

    Science.gov (United States)

    Gonzales, Patricia; Ajami, Newsha; Sun, Yujie

    2017-09-01

    Water utilities are increasingly relying on water efficiency and conservation to extend the availability of supplies. Despite spatial and institutional interdependency of many utilities, these demand-side management initiatives have traditionally been tackled by individual utilities operating in isolation. In this study, we introduce a policy framework for water conservation credits that enables collaboration at the regional scale. Under the proposed approach, utilities have the flexibility to invest in water conservation measures that are appropriate for their specific service area. When utilities have insufficient capacity for local cost-effective measures, they may opt to purchase credits, contributing to fund subsidies for utilities that do have that capacity and can provide the credits, while the region as a whole benefits from more reliable water supplies. This work aims to provide insights on the potential impacts of a water conservation credit policy framework when utilities are given the option to collaborate in their efforts. We model utility decisions as rational cost-minimizing actors subject to different decision-making dynamics and water demand scenarios, and demonstrate the institutional characteristics needed for the proposed policy to be effective. We apply this model to a counterfactual case study of water utility members of the Bay Area Water Supply and Conservation Agency in California during the drought period of June 2015 to May 2016. Our scenario analysis indicates that when the institutional structure and incentives are appropriately defined, water agencies can achieve economic benefits from collaborating in their conservation efforts, especially if they coordinate more closely in their decision-making.

  12. 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

  13. 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

  14. 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

  15. 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

  16. 40 CFR 52.2285 - Control of evaporative losses from the filling of gasoline storage vessels in the Houston and San...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control of evaporative losses from the filling of gasoline storage vessels in the Houston and San Antonio areas. 52.2285 Section 52.2285... of gasoline storage vessels in the Houston and San Antonio areas. (a) Definitions: (1) Gasoline means...

  17. 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

  18. 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

  19. Humboldt Bay, California Benthic Habitats 2009 Geodatabase

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  20. Humboldt Bay Benthic Habitats 2009 Aquatic Setting

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  1. Humboldt Bay, California Benthic Habitats 2009 Substrate

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  2. Humboldt Bay, California Benthic Habitats 2009 Geoform

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 76 FR 45693 - Safety Zone; San Diego POPS Fireworks, San Diego, CA

    Science.gov (United States)

    2011-08-01

    ...-AA00 Safety Zone; San Diego POPS Fireworks, San Diego, CA AGENCY: Coast Guard, DHS. ACTION: Temporary... San Diego Bay in support of the San Diego POPS Fireworks. This safety zone is necessary to provide for... of the waterway during scheduled fireworks events. Persons and vessels will be prohibited from...

  8. 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.)

  9. 33 CFR 110.74c - Bahia de San Juan, PR.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bahia de San Juan, PR. 110.74c Section 110.74c Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.74c Bahia de San Juan, PR. The waters of San Antonio...

  10. 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.

  11. 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. 

  12. LPD 17 San Antonio Class Amphibious Transport Dock (LPD 17)

    Science.gov (United States)

    2015-12-01

    Grumman’s shipbuilding division and deferred depreciation expenses for recovery of insurance proceeds associated with Hurricane Katrina damages. Contract...Safety and Health Administration and the Pension Protection Act. The government liability for deferred depreciation from Hurricane Katrina was...of engineering change proposals and negotiation of a contract price adjustment to cover the Navy’s share of deferred depreciation expenses for

  13. San Antonio Creek Restoration, Vandenberg Air Force Base, California

    Science.gov (United States)

    2008-06-27

    Vandenberg Air Force Base Scientific Name Common Name Scientific Name Common Name Sambucus mexicana Blue elderberry Sonchus oleraceus * Common sow... Sonchus oleraceus Common sow-thistle exotic NI Spergularia bocconii Sand-spurry exotic FAC Spergularia marina Sand-spurry native FACW...border the existing roads within the project area. Both weedy non-native species adapted to frequent disturbance, such as sow thistle ( Sonchus

  14. 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.

  15. 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

  16. 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...

  17. An empirical test of the 'shark nursery area concept' in Texas bays using a long-term fisheries-independent data set

    Science.gov (United States)

    Froeschke, John T.; Stunz, Gregory W.; Sterba-Boatwright, Blair; Wildhaber, Mark L.

    2010-01-01

    Using a long-term fisheries-independent data set, we tested the 'shark nursery area concept' proposed by Heupel et al. (2007) with the suggested working assumptions that a shark nursery habitat would: (1) have an abundance of immature sharks greater than the mean abundance across all habitats where they occur; (2) be used by sharks repeatedly through time (years); and (3) see immature sharks remaining within the habitat for extended periods of time. We tested this concept using young-of-the-year (age 0) and juvenile (age 1+ yr) bull sharks Carcharhinus leucas from gill-net surveys conducted in Texas bays from 1976 to 2006 to estimate the potential nursery function of 9 coastal bays. Of the 9 bay systems considered as potential nursery habitat, only Matagorda Bay satisfied all 3 criteria for young-of-the-year bull sharks. Both Matagorda and San Antonio Bays met the criteria for juvenile bull sharks. Through these analyses we examined the utility of this approach for characterizing nursery areas and we also describe some practical considerations, such as the influence of the temporal or spatial scales considered when applying the nursery role concept to shark populations.

  18. 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 ...

  19. 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

  20. Antonio Lopez: Fashion, Art, Sex & Disco

    DEFF Research Database (Denmark)

    Langkjær, Michael Alexander

    2014-01-01

    Book review. Roger Padilha and his brother Mauricio may already be familiar to some as the New York-based fashion publicists, creators of the fashion public relations agency MAO PR, and as authors of The Stephen Sprouse Book (Rizzoli, 2009). Antonio Lopez: Fashion, Art, Sex & Disco, their second...

  1. SF Bay Water Quality Improvement Fund: Projects and Accomplishments

    Science.gov (United States)

    San Francisco Bay Water Quality Improvement Fund (SFBWQIF) projects listed here are part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  2. 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,…

  3. 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...

  4. Cuadros de Juan del Castillo y Antonio del Castillo en el Ermitage

    Directory of Open Access Journals (Sweden)

    Kagané, L.

    2003-06-01

    Full Text Available Juan del Castillo y Antonio del Castillo son dos pintores que trabajaron en Andalucía. Hace algún tiempo se consideraba que Antonio era el sobrino de Juan, actualmente es sabido que no es así, aunque no se excluye que fuesen parientes. Al ingresar los cuadros de estos pintores en el Ermitage tuvo lugar una confusión debida al parecido de sus apellidos y las obras de uno de ellos se atribuían en los inventarios al otro. Así ocurrió con el pequeño cuadro Visitación (Fig. 1. Fue adquirido en 1834 a Juan Miguel Páez de la Cadena, embajador de España en San Petersburgo, e incluido en el catálogo manuscrito del museo sin haber indicado el nombre. En el Livret y en todos los posteriores catálogos del Ermitage de antes de la revolución, el cuadro fue asignado bajo el nombre de Antonio del Castillo…

  5. ANTONIO LAMELA - beyond innovation In Memory

    Directory of Open Access Journals (Sweden)

    P. Cassinello

    2018-01-01

    Full Text Available Spanish architecture is in mourning. One of its most beloved referents, Antonio Lamela passed away on April 1, 2017. He has left us an extensive and polyhedral legacy that continues to live in the urban fabric of our cities, in the pages of his books, and in the model of thought and action, which presided over by the effort and the desire to innovate, led him to reach the highest levels of our profession. A model with which he founded his office in 1954 and which today, directed for many years by his son Carlos Lamela, has a relevant international representation having carried out projects in 32 countries. Beyond the formal and technological innovation of his buildings, in the 1950s Antonio Lamela established in Spain companies such as Prebetong and Shokbeton to modernize Spanish construction, actively intervening in the necessary expansion of “Caja de Elementos of Construction” demanded by Le Corbusier since the twenties. Changing his perspective, Antonio Lamela has also bequeathed us his pioneering reflections on the proper management of natural resources and the necessary sustainability of the architecture of our planet within the cosmos in which it lives. He will always be an unavoidable model for future generations.

  6. 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...

  7. Antonio Mollari, un problema di comunicazione / Antonio Mollari, a communication problem

    Directory of Open Access Journals (Sweden)

    Gianfranco Berchiesi

    2015-01-01

    Full Text Available La riscoperta della figura di Antonio Mollari, in seguito al ritrovamento presso il Comune di Petriolo di cinque sue tavole acquerellate, ebbe inizio con la mostra del 2006, nella quale l’esposizione di alcune delle più interessanti tavole conservate a Trieste, Foligno e Macerata e una conferenza del Prof. Cruciani Fabozzi, seguita dalla storia della famiglia Mollari ad opera dell’Ing. Carratù, delinearono un primo “ritratto” della personalità di Antonio Mollari. Da quella data è poi maturata l’idea di indagare in maniera più adeguata la sua attività, giungendo al Convegno tenuto all’Abbadia di Fiastra nel 2013. L’autore mette in evidenza come la figura di Antonio Mollari, al di là del giudizio tecnico che possono esprimere i relatori che si sono succeduti nel Convegno, ha un problema legato alla comunicazione. Chi era Mollari e come potrebbe essere adeguatamente presentato in una riunione di persone non addette ai lavori? Era architetto, ingegnere, tecnico? Oppure, alla bisogna, era l’una o l’altra di queste figure? In this report it is narrated that in 2006 the figure of Antonio Mollari was reproposed, after the discovery of five watercolor maps at the municipality of Petriolo, by means of a small exhibition to which Prof. Cruciani Fabozzi gave the right approach. From that date an interest in the idea of a more appropriate and extensive discussion on Antonio Mollari is later gained, reaching the Conference held in the Abbey of Fiastra in 2013. The author highlights how the figure of Antonio Mollari has a problem with the communication, beyond the technical opinion, expressed by the speakers that have taken place in the conference. Who was Mollari and how could he be adequately presented at a meeting of persons not qualified in this matter? It was Architect or Engineer? Or, as needed, was the one or the other of these figures?

  8. La presidencia de Miguel Antonio Caro

    Directory of Open Access Journals (Sweden)

    Beatriz González

    2000-05-01

    Full Text Available Cien años de los mil días: Los mil días en treinta y dos pasos. Capítulo 2 El gobierno de Miguel Antonio Caro mantenía un ejército relativamente grande, de unos seis mil hombres. Para su reforma y organización trajo una misión francesa. En el ambiente belicista que se vivía en el país. se publicaron y reeditaron libros sobre la técnica del manejo de las armas.

  9. Antonio Caldara v kontextu své doby

    Czech Academy of Sciences Publication Activity Database

    Jonášová, Milada

    2016-01-01

    Roč. 24, č. 11 (2016), s. 36-37 ISSN 1210-9525. [Antonio Caldara im Kontext seiner Zeit. Český Krumlov, 17.09.2016-18.09.2016] Institutional support: RVO:68378076 Keywords : Antonio Caldara * conference * Český Krumlov * opera performance Subject RIV: AL - Art, Architecture, Cultural Heritage

  10. Antonio Porta and Seventeenth-Century Central European Architecture

    Czech Academy of Sciences Publication Activity Database

    Krummholz, Martin

    -, 0118 (2015), s. 1-24 ISSN 2190-3328 Institutional support: RVO:68378033 Keywords : Antonio Porta * Francesco Caratti * J. B. Mathey * architecture * palace * chateau * Vienna * Turin * F. Luchese * G. P. Tencalla * Roudnice nad Labem Subject RIV: AL - Art, Architecture , Cultural Heritage http://www.riha-journal.org/articles/2015/2015-jan-mar/krummholz-antonio-porta

  11. Antonio Ricci en Madrid: 1586-1635

    Directory of Open Access Journals (Sweden)

    García López, David

    2010-03-01

    Full Text Available Life of painter Antonio Ricci is studied by new documents from his arrived at Escorial with Federico Zuccari in 1586. Ricci worked in the Palace of Madrid and was involved in the birth of the Academy of Painting. Here are studied his work as Painter and Appraiser, or his portrait of Philip IV of Spain and his relationship with Jeronimo Gratti, Caballero de Gracia.

    Nuevas aportaciones documentales aclaran la vida del pintor Antonio Ricci en la Corte española desde su llegada a El Escorial junto a Federico Zuccari en 1586. Ricci trabajó como pintor en el entorno palaciego y estuvo involucrado desde el principio en el intento de creación de la Academia madrileña de pintores. Se detallan aquí su trabajo como tasador, su retrato del futuro Felipe IV o su cercana relación con un personaje tan singular como Jeronimo Gratti, el Caballero de Gracia.

  12. Juan Antonio Rubio Rodriguez (1944 – 2010)

    CERN Multimedia

    His colleagues and friends

    2010-01-01

    It was with deep sorrow and great sadness that we learnt that Juan Antonio Rubio Rodriguez had passed away on 16th January 2010. Juan Antonio was born in Madrid on 4th June 1944, and received his Ph. D. in Physics in 1971 from“Universidad Complutense de Madrid”. He was a CERN Fellow (1968 – 1971) and subsequently worked at JEN (currently CIEMAT) as a researcher (1971 – 1976). He was leader of the HEP group (1977 – 1981), leader of the Nuclear and Particle Physics Division (1981 – 1983), Director for Basic Research (1983 – 1987) and Scientific Director (1984 – 1987). He was instrumental in the Spanish accession to CERN approved by the Spanish Government at the end of 1982 and ratified by the Spanish Parliament in June 1983. He served at CERN (1987 – 2004) as Group Leader (1987 – 1990), Scientific Advisor to the Director-General (1990 – 2000) and as Division Leader of the Education and Technology T...

  13. 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

  14. 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

  15. California: Environmental Health Coalition Clean Ports, Healthy Communities in San Diego (A Former EPA CARE Project)

    Science.gov (United States)

    The Environmental Health Coalition (EHC) is a recipient of a CARE Level II cooperative agreement grant. The Clean Ports, Healthy Communities in San Diego targets the Barrio Logan and Old Town National City areas located along San Diego Bay.

  16. 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...

  17. 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

  18. 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

  19. Interview of Antonio Vergara Fernandez about the First Beam

    CERN Multimedia

    Antonio Vergara Fernandez

    2008-01-01

    Antonio Vergara Fernandez : Engineer of the LHC commissioning Questions asked : 1. What does it take to start up the LHC machine? 2. What's the plan for 1st injection day? 3. How do you feel about this?

  20. 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

  1. Antonio Canova and the Whatever Body

    Directory of Open Access Journals (Sweden)

    Cora Hatshepsut Gilroy-Ware

    2017-02-01

    Full Text Available This article looks at the persistence of classicizing art in postmodern imagery. Specifically, I posit the art of Antonio Canova as a precursor to contemporary fashion advertising, arguing against the notion that his oeuvre is wholly irrelevant to contemporary culture. I focus on a selection of paintings by Canova, works that, having received scant attention from scholars, are obscure in relation to the artist’s corpus of sculpture. At first glance, these paintings are little more than odd pastiches of 16th century old master works, only with figures marked by a highly refined and conspicuously modern appropriation of ideal beauty. Rather than marginal curiosities or footnotes to his figures in marble, these paintings will be discussed for their distinctive treatment of the female form. I frame the artist as a transitional figure, one whose overturning of moralizing deployments of ideal beauty initiated a new corporeal type that endures in the figure of the fashion model. Returning Canova to the central position he once occupied in the nineteenth century, I incorporate the work of Giorgio Agamben, John Berger and Frederic Jameson. Like Aby Warburg’s 'Mnemosyne Atlas', my argument is largely founded on the eloquence of the images themselves.

  2. Eisenstein contemporain : entretien avec Antonio Somaini

    Directory of Open Access Journals (Sweden)

    Bruno Leites

    2016-04-01

    Full Text Available Entretien avec Antonio Somaini à propos des films, des écrits et des dessins de Sergei Eisenstein. Somaini est actuellement un des plus grands spécialistes de l’œuvre d’Eisenstein. À l’entretien, nous parlons de nombreux sujets : les défis de traduire les ouvrages d’Eisenstein, les phases de sa carrière, le développement de sa pensée, la relation de ses films avec ses écrits, sa pratique du dessin et sa passion pour les dessins de Walt Disney. C’est un long entretien dans laquelle nous parlons aussi des principaux concepts d’Eisenstein, tels que l’extase, le pathos, l’organicité, l’attraction, la régression et la plasmaticité. Somaini nous parle également de la spécificité de son travail et de l’urgence de reprendre Eisenstein. D’un côté, il faut le faire sortir de l’histoire du cinéma exclusivement et l’inclure dans le réseau le plus vaste des arts et de la pensée des années 1920, 1930 et 1940. De l’autre côté, il faut penser son projet comme essentiellement contemporain. Comme Somaini l’a dit, ce que nous pensons beaucoup aujourd’hui, le dispositif cinématographique, le rapport entre le cinéma et l’histoire de l’art, l'influence des images sur l’ensemble de l’expérience humaine, cela a toujours été le problème d’Eisenstein.

  3. 33 CFR 110.224 - San Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay, Sacramento River, San Joaquin...

    Science.gov (United States)

    2010-07-01

    ... area shown on a Government chart. (5) No vessel may moor, anchor, or tie up to any pier, wharf, or... supervision may go alongside or in any manner moor to any Government-owned vessel, mooring buoy, or pontoon...); and the side boundaries of which are parallel tangents joining the semicircles. A forbidden anchorage...

  4. 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

  5. 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

  6. 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

  7. 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

  8. 2004 USGS Lidar: San Francisco Bay (CA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Lidar (Light detection and ranging) discrete-return point cloud data are available in the American Society for Photogrammetry and Remote Sensing (ASPRS) LAS format....

  9. San Francisco Bay Area Cargo Forecast.

    Science.gov (United States)

    1981-06-01

    typically moved by container.* Trend line regression equations were developed from this data that show a long and stable history of high growth on...216.7 2 A Mazda 65.4 35.4 50.6 75.3 i56.5 Subaru 41.6 18.4 80.8 103.2 :27.9 Fiat 100.5 51.5 63.5 50.4 53.9 Volvo 60.3 43.9 46.8 50.9 56.) Total 1,577.0

  10. san_francisco_bay_ca_mhw.grd

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC builds and distributes high-resolution, coastal digital elevation models (DEMs) that integrate ocean bathymetry and land topography to support NOAA's mission to...

  11. 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...

  12. En el entierro de Antonio Ucrós Cuéllar.

    Directory of Open Access Journals (Sweden)

    Zoilo Cuéllar-Montoya

    2005-09-01

    Hoy el destino pone en mis labios el adiós definitivo a quien más que tío, fue un gran amigo, colega y profesor y me corresponde hacerlo a título personal y a nombre de la Academia Nacional de Medicina de Colombia, de la cual fue Antonio, su ilustre Miembro de Número. Quiero pintar con las palabras, para que permanezca en nuestros corazones, la figura señera de Antonio; su sonrisa abierta y franca; su forma de ser, directo, concreto y, ciertamente, incondicional en el afecto y la amistad; fue vertical en sus conceptos éticos e intachable en su vida, tanto en la profesional como en la privada. Se destacó, indiscutiblemente, como brillante profesional de la endocrinología, dentro de la cual fue pionero en la subespecialidad pediátrica. Brilló como docente, pues fue indiscutible maestro de su ciencia, cofundador de la Facultad de Medicina del Colegio Mayor de Nuestra Señora del Rosario, como Miembro de Número que era de la Sociedad de Cirugía de Bogotá y del Cuerpo facultativo del Hospital de San José, Facultad de la cual ocupó la Decanatura. Pero fue, sobre todo, consecuencia lógica de su bonhomía, verdadero honor a su estirpe, un incansable apóstol de su profesión: son incontables los menesterosos de salud para el cuerpo y para el alma que, en el curso de su valiosa vida, en su consultorio particular, en los vetustos pabellones de los hospitales que frecuentó, en su casa de campo o aún en la de Bogotá, recibieron de él una generosa y desinteresada ayuda, material y espiritual...

  13. The effect of physical and chemical parameters on the macroinfaunal community structure of San Vicente bay, Chile Efectos de parámetros físicos y químicos en la estructura comunitaria de la macroinfauna en la bahía de San Vicente, Chile

    Directory of Open Access Journals (Sweden)

    ROCÍO A. SIEMENS

    2001-06-01

    Full Text Available San Vicente bay is a heavily industrialised bay located in central Chile, which has a sand beach extending from an area of recreational use in the south to an area of industrial use and discharge in the north. A survey of the macrofauna in the intertidal zone revealed a non-homogeneous distribution; a maximum of five invertebrate species were found with all five only occurring in one of six transects down the beach. The density ranged from 0 to 188 individuals m-2, with the highest density at the recreational end. The most common species, Emerita analoga (Stimpson, was chosen to study the macrofaunal response to beach morphodynamics, physicochemical parameters and metal concentrations. The E. analoga distribution was not significantly correlated with the results of the physicochemical analyses of interstitial water (pH, temperature, salinity and oxygen concentrations. However, oxygen concentrations decreased to 3 ml O2 l-1 in the lower intertidal closest to the recreational area where the highest numbers of intertidal macrofauna were observed. Analyses of 12 metals in the sediments showed three distinct distribution patterns across the beach in which the metals could be classified: a representative metal was chosen for each distribution. The concentration of tin ranged from 3.4 to 11.58 mg g-1DW sediment, representing the `wave' pattern. The concentration of cadmium ranged from 0 to 0.23 mg g-1DW sediment, representing the `banded' pattern. The concentration of chromium ranged from 1.97 to 3.18 mg g-1DW sediment, representing the `intermediate' pattern of metal distribution. The E. analoga distribution was not significantly correlated with the concentrations of any single metal, although multivariate statistical analysis indicated that Sn and Fe had the largest negative effect and Mn had the largest positive one. The distribution of E. analoga across the sandy beach of San Vicente bay was significantly correlated with the relative tidal range

  14. Concentración de metales pesados (Cu, Ni, Zn, Cd, Pb en la biota y sedimentos de una playa artificial, en la bahía San Jorge 23°S, norte de Chile Heavy metals concentration (Cu, Ni, Zn, Cd, Pb, in biota and sediments of an artificial beach, in San Jorge bay 23°S, northern Chile

    Directory of Open Access Journals (Sweden)

    Gabriel Castro

    2012-07-01

    Full Text Available Se evaluó el contenido de metales pesados (Cu, Ni, Zn, Cd, Pb en la biota y el sedimento de una playa artificial (Paraíso y una playa natural (El Lenguado, ubicadas en la bahía San Jorge, norte de Chile. Los resultados fueron utilizados para comparar ambos sistemas, el grado de cumplimiento de la normativa ambiental nacional e internacional, y el efecto de la construcción de la playa artificial sobre el nivel de contaminación por metales existentes históricamente en esa zona. En cada playa se ubicaron estaciones equidistantes que abarcaron desde el intermareal hasta el submareal de las cuales fueron extraídos los organismos. Se tomaron muestras de sedimento en cada playa y se determinaron las pendientes con el método de Emery. El análisis granulométrico evidenció el predominio de arena media en playa El Lenguado, y arena media y fina en playa Paraíso. El contenido de materia orgánica fue mayor en El Lenguado. En playa Paraíso se determinaron cinco phylum/superclase agrupados en 19 taxa, mientras que en El Lenguado se encontraron cuatro phylum/superclase agrupados en cc taxa. El contenido de metales en sedimentos y en la mayoría de organismos presentó valores mayores en playa Paraíso. Estos resultados, junto a las normas de calidad chilenas y norteamericanas, sugieren un evidente deterioro en la calidad ambiental de playa Paraíso lo que se demostró por un incremento en las concentraciones de estos metales desde su construcción, los que sobrepasan los límites establecidos por ambas normas.It was evaluated the heavy metal content (Cu, Ni, Zn, Cd, Pb in biota and sediment of an artificial beach (Paraíso and a natural beach (El Lenguado, both located in San Jorge bay, northern Chile. The results were used to compare both systems, the degree of fulfillment of national and international environmental regulations, and the effect of the construction of the artificial beach on the level of metal contamination historically existing in

  15. Antonio Gramsci on intellectual thought – Challenging nursing

    OpenAIRE

    Goodman, B

    2017-01-01

    publisher: Elsevier articletitle: Antonio Gramsci on intellectual thought – Challenging nursing journaltitle: Nurse Education Today articlelink: http://dx.doi.org/10.1016/j.nedt.2017.02.023 content_type: simple-article copyright: © 2017 Elsevier Ltd. All rights reserved.

  16. In Memoriam Antonio Reales Orozco (1917-1997

    Directory of Open Access Journals (Sweden)

    Efraim Otero Ruiz

    1997-12-01

    Full Text Available


    Para la academia Nacional de Medicina, en su ámbito más nacional, constituye motivo de sincera condolencia la desaparición, el pasado 23 de febrero, del Académico de Número Dr. Antonio Reales Orozco. Nacido, criado y educado en Barranquilla, el Dr. Reales Orozco se graduó de médico de la Universidad Nacional en 1944 y desde entonces se orientó por la Psiquiatría, especialidad que ejerció por más de cincuenta años.

    Además de haber ocupado por varios años la dirección de diversos frenocomios de hombres y de mujeres en su ciudad natal, fue fundador, codirector y copropietario de la Clínica Psiquiátrica del Atlántico, institución privada en que durante más de treinta años prestó destacados servicios a toda la región de la costa atlántica.

    Ingresó como Miembro Correspondiente en 1983 con el trabajo “El hombre y las ciencias del comportamiento” para posteriormente, en 1986 ascender a la categoría de Miembro de Número con su trabajo “Estudio de mil casos médico-psiquiátricos” que recibió calurosos elogios del ya desaparecido Académico Profesor José Francisco Socarrás.

    Retirado del ejercicio activo de la profesión se dedicó, a partir de ese año, a investigar temas históricos de trascendental importancia que publicó en dos libros, cuyas presentaciones formales se hicieron en el recinto de la Academia: uno, en 1988, titulado Bolívar frente a los médicos y la medicina, en que hace un profundo análisis psicológico de la desconfianza que sentía el Libertador hacia los médicos y analiza la trayectoria de aquellos galenos ejemplares que lo acompañaron en la última etapa de su vida, cuando viaja de Bogotá hacia la costa del Caribe para ir a morir finalmente en la Quinta de San Pedro Alejandrino.}

    El otro, titulado Santander; fundador del Estado Colombiano trazó, en 24 vigorosos capítulos, que van desde el nacimiento hasta la enfermedad y muerte del General Francisco de

  17. Pietro Antonio Tomasello de Padua : un ingeniero militar véneto en la Sicilia de Carlos V

    Directory of Open Access Journals (Sweden)

    Maurizio Vesco

    2011-01-01

    Full Text Available En 1522 el virrey de Sicilia, Ettore Pignatelli, conde de Monteleone, inició una gran campaña para fortalecer las defensas de las principales ciudades de la costa de Sicilia: Palermo, Trapani, Milazzo, Siracusa y, algunos años más tarde, incluso Messina. El ingeniero real Pietro Antonio Tomasello de Padua, un técnico militar Veneto, pidió renovar el sistema de defensas de la isla, con la introducción por primera vez de bastiones circulares y poligonales en fortalezas y murallas de la ciudad. La obra, desconocida hasta ahora, de este importante ingeniero militar activo en Sicilia desde 1523 hasta 1537, año de su muerte, está siendo reconstruida con una importante documentación de archivo. La investigación destaca líneas de continuidad en la estrategia de guerra de Carlos V, lanzada en Sicilia desde la época del virrey Conde de Monteleone. En consecuencia, se hace necesario revisar este extraordinario carácter general dado por los historiadores de la política militar de Ferrante Gonzaga. También hay que revisar la actualización y la autoría de muchas de las fortificaciones más importantes de Sicilia: el fuerte de San Salvador de Messina, anteriormente atribuido a Antonio Ferramolino de Bérgamo, las fortificaciones de defensa y escarpes del castillo de Milazzo y la torre circular de Castellammare de Palermo (estos últimos fechados en la segunda mitad del siglo XV, todas las obras son de Pietro Antonio Tomasello, realizadas en el segundo cuarto del siglo XVI.In 1522 the Viceroy of Sicily Ettore Pignatelli, Count of Monteleone, started a significant campaign for the strengthening of the outworks of the main cities located along the Sicilian coast: Palermo, Trapani, Milazzo, Siracusa and, after a few years, also Messina. The Royal Engineer Pietro Antonio Tomasello from Padua, a military technician from the Veneto region, was charged with renovating the island’s defensive system and introducing for the first time modern circular

  18. San Marino.

    Science.gov (United States)

    1985-02-01

    San Marino, an independent republic located in north central Italy, in 1983 had a population of 22,206 growing at an annual rate of .9%. The literacy rate is 97% and the infant mortality rate is 9.6/1000. The terrain is mountainous and the climate is moderate. According to local tradition, San Marino was founded by a Christian stonecutter in the 4th century A.D. as a refuge against religious persecution. Its recorded history began in the 9th century, and it has survived assaults on its independence by the papacy, the Malatesta lords of Rimini, Cesare Borgia, Napoleon, and Mussolini. An 1862 treaty with the newly formed Kingdom of Italy has been periodically renewed and amended. The present government is an alliance between the socialists and communists. San Marino has had its own statutes and governmental institutions since the 11th century. Legislative authority at present is vested in a 60-member unicameral parliament. Executive authority is exercised by the 11-member Congress of State, the members of which head the various administrative departments of the goverment. The posts are divided among the parties which form the coalition government. Judicial authority is partly exercised by Italian magistrates in civil and criminal cases. San Marino's policies are tied to Italy's and political organizations and labor unions active in Italy are also active in San Marino. Since World War II, there has been intense rivalry between 2 political coalitions, the Popular Alliance composed of the Christian Democratic Party and the Independent Social Democratic Party, and the Liberty Committee, coalition of the Communist Party and the Socialist Party. San Marino's gross domestic product was $137 million and its per capita income was $6290 in 1980. The principal economic activities are farming and livestock raising, along with some light manufacturing. Foreign transactions are dominated by tourism. The government derives most of its revenue from the sale of postage stamps to

  19. Antonio Aliprandi, un estucador lombardo en la Valencia de 1700

    Directory of Open Access Journals (Sweden)

    Pablo González Tornel

    2002-01-01

    Full Text Available En torno a 1700 aparecen en Valencia varios artistas extranjeros que residirán en la ciudad varios años dejando en ella un considerable volumen de obras. Uno de ellos, Antonio Aliprandi, se especializará en la factura de revestimientos de estuco para interiores principalmente eclesiásticos. En el presente texto se realiza un recorrido por las obras de Aliprandi en Valencia y se documentan varias de ellas hasta el momento sólo atribuidas a su mano.Around 1700 many foreign artists appear in Valencia where they will stand for several years leaving in our town quite a lot of handcrafts. One among them, Antonio Aliprandi, will specialize himself on recovering many buildings with stucco, mainly in churches. This text makes a journey along Aliprandi's art pieces in Valencia after working on files to find the documents refered to them.

  20. El anhelo metafísico de Antonio Machado

    OpenAIRE

    Carlos Llano Cifuentes

    2013-01-01

    In Antonio Machado's poetry, a dissatisfied agnosticism appears; that is, a kind of agnosticism which wants to quit being such, an agnosticism with metaphysical longings. Machado knows that the absence of trascendence does not offer peacefulness, but tediousness and resignation against the changing reality. Being lacks the plenitude it once had and, in this sense, there exists in Machado a double way to understand reality: longing for what was and confirmation of the present. All this generat...

  1. Marco Antonio Chaer Nascimento a festschrift from theoretical chemistry accounts

    CERN Document Server

    Ornellas, Fernando R

    2014-01-01

    In this Festschrift dedicated to the 65th birthday of Marco Antonio Chaer Nascimento, selected researchers in theoretical chemistry present research highlights on major developments in the field. Originally published in the journal Theoretical Chemistry Accounts, these outstanding contributions are now available in a hardcover print format. This volume will be of benefit in particular to those research groups and libraries that have chosen to have only electronic access to the journal. It also provides valuable content for all researchers in theoretical chemistry.

  2. ANTONIO GAMONEDA: LA CONSTRUCCIÓN DEL OLVIDO

    Directory of Open Access Journals (Sweden)

    Jorge Fernández Gonzalo

    2014-10-01

    Full Text Available Nuestro estudio trata de analizar el concepto de memoria y olvido en la producción poética de Antonio Gamoneda a través de obras como Descripción de la mentira, Lápidas, Libro del frío o Arden las pérdidas, y en relación al período histórico que le tocó vivir al autor.

  3. Manuel Antonio Noriega. Panama kindral liigub vanglast vanglasse / Arko Olesk

    Index Scriptorium Estoniae

    Olesk, Arko, 1981-

    2007-01-01

    Ilmunud ka: Postimees : na russkom jazõke 7. sept. lk. 13. Narkootikumide salakaubaveo, väljapressimise ja rahapesu eest USA vanglas viibiva Panama endise sõjaväejuhi Manuel Antonio Noriega vabanemisest, uuest kohtuteest Prantsusmaal, Panamas tagaselja tehtud kohtuotsusest mõrvade, inimõiguste rikkumise ja korruptsiooni eest. Panama sõjalise diktaatori eluteest, võimulepääsemisest ning USA sõjalisest invasioonist 1989. aastal, mis lõpetas kindrali võimu

  4. A Commander’s Guide for Conducting Integration Operations in the San Antonio Military Health System

    Science.gov (United States)

    1999-02-01

    Conducting Integration Operations 27 Denzin , Norman and Lincoln , Yvonna. (1994). Handbook of Qualitative Research. Sage Publications. Thousand Oaks...the Defense. (1998). “Program Decision Memorandum.” August 18, 1998. Phillips, Donald. (1992). Lincoln on Leadership. Warner Books. New York. 1992

  5. Environmental Assessment of Installation Development at Joint Base San Antonio-Lackland, Texas

    Science.gov (United States)

    2013-02-01

    Sanitary Sewer Lines Upgrades Natural Infrastructure Management Projects • Nil. Medio Creek Erosion Control • NI2. Warrior Week Road- Leon Creek Bridge...Intrastate MSL mean sea level MSW municipal solid waste MWD Military Working Dog NAAQS National Ambient Air Quality Standards NAGPRA Native...2-39  2-25. Proposed Location for Project NI1, Medio Creek Erosion Control

  6. Water quality modelling in the San Antonio River Basin driven by radar rainfall data

    OpenAIRE

    Almoutaz Elhassan; Hongjie Xie; Ahmed A. Al-othman; James Mcclelland; Hatim O. Sharif

    2016-01-01

    Continuous monitoring of stream water quality is needed as it has significant impacts on human and ecological health and well-being. Estimating water quality between sampling dates requires model simulation based on the available geospatial and water quality data for a given watershed. Models such as the Soil and Water Assessment Tool (SWAT) can be used to estimate the missing water quality data. In this study, SWAT was used to estimate water quality at a monitoring station near the outlet of...

  7. AFHRL Conference on Human Appraisal: Proceedings Held at San Antonio, Texas, 19-21 March 1979

    Science.gov (United States)

    1981-06-01

    have branched again into many more specific skills; soldering, writing , hammering, sawing, throwing, arid on and on. These skills and knowledges branch...Berkeley) does--they recommended actually writing critical incidents on the scales, a minimum of two--like the original work with the National League of...asked him "How are you evaluating acceptability in this 128 Wk L7 _ us#m?" And he said to me, "Client satisfaction." I asked him what he ielt , lie said

  8. E3 Success Story - San Antonio E3 Case Study: UEMC “Now Hiring”

    Science.gov (United States)

    exas Manufacturing Assistance Center conducted an E3 assessment as part of the local Lean-Clean-Energy program in October of 2009. Overall, UEMC has reduced demand by approximately 30kw and reduced consumption by over 100,000 kwh/year.

  9. Abstracts of the Annual Meeting of Planetary Geologic Mappers, San Antonio, TX, 2009

    Science.gov (United States)

    Bleamaster, Leslie F., III (Editor); Tanaka, Kenneth L.; Kelley, Michael S.

    2009-01-01

    Topics covered include: Geologic Mapping of the Beta-Atla-Themis (BAT) Region of Venus: A Progress Report; Geologic Map of the Snegurochka Planitia Quadrangle (V-1): Implications for Tectonic and Volcanic History of the North Polar Region of Venus; Preliminary Geological Map of the Fortuna Tessera (V-2) Quadrangle, Venus; Geological Map of the Fredegonde (V-57) Quadrangle, Venus; Geological Mapping of the Lada Terra (V-56) Quadrangle, Venus; Geologic Mapping of V-19; Lunar Geologic Mapping: A Preliminary Map of a Portion of the LQ-10 ("Marius") Quadrangle; Geologic Mapping of the Lunar South Pole, Quadrangle LQ-30: Volcanic History and Stratigraphy of Schr dinger Basin; Geologic Mapping along the Arabia Terra Dichotomy Boundary: Mawrth Vallis and Nili Fossae, Mars; Geologic Mapping Investigations of the Northwest Rim of Hellas Basin, Mars; Geologic Mapping of the Meridiani Region of Mars; Geology of a Portion of the Martian Highlands: MTMs -20002, -20007, -25002 and -25007; Geologic Mapping of Holden Crater and the Uzboi-Ladon-Morava Outflow System; Mapping Tyrrhena Patera and Hesperia Planum, Mars; Geologic Mapping of Athabaca Valles; Geologic Mapping of MTM -30247, -35247 and -40247 Quadrangles, Reull Vallis Region, Mars Topography of the Martian Impact Crater Tooting; Mars Structural and Stratigraphic Mapping along the Coprates Rise; Geology of Libya Montes and the Interbasin Plains of Northern Tyrrhena Terra, Mars: Project Introduction and First Year Work Plan; Geology of the Southern Utopia Planitia Highland-Lowland Boundary Plain: Second Year Results and Third Year Plan; Mars Global Geologic Mapping: About Half Way Done; New Geologic Map of the Scandia Region of Mars; Geologic Mapping of the Medusae Fossae Formation on Mars and the Northern Lowland Plains of Venus; Volcanism on Io: Insights from Global Geologic Mapping; and Planetary Geologic Mapping Handbook - 2009.

  10. Study of Medical Ethics Areas of Concern in the Greater San Antonio Area

    Science.gov (United States)

    2006-06-01

    3 4 5 nosocomial infections 1 2 3 4 5 failure to provide patient education 1 2 3 4 5 failure to appropriately address patterns of substandard care 1 2...Modified Delphi Study 58 94 maternal /fetal issues at threshold of viability 95 end of life clarification to families about having directives 96 lab

  11. PUBLIC-PRIVATE COMPETITIONS: Reasonable Processes Used for San Antonio Engine Depot Maintenance Award

    National Research Council Canada - National Science Library

    1999-01-01

    .... 2469a and other applicable laws and regulations, appropriate consideration was given to factors other than cost, and the award resulted in the lowest total cost to the Department of Defense (DOD) for performance of the work.

  12. Transformation of safety culture on the San Antonio service unit of Union Pacific Railroad

    Science.gov (United States)

    2012-10-31

    The Federal Railroad Administration conducted a pilot demonstration of Clear Signal for Action (CSA), a risk reduction process : that combines peer-to-peer feedback, continuous improvement, and safety leadership development. An independent formative ...

  13. A Qualitative Study of Affordability: Virginia and San Antonio Class Programs

    Science.gov (United States)

    2014-06-04

    under a cost-plus-fixed-fee (CPFF) contract for the electric plant and later added cost-plus-award fee for the construction of the ship (Schank et al...From Defense Acquisition University (DAU, n.d.) ACRONYMS ACWP Actual Cost of Wart PerRm!ed AlJW Authorizecl Urpiced Wak BAG Budge{ A1 Cornple5on

  14. Industry - Military Energy Symposium, held 21-23 October 1980, San Antonio, Texas

    Science.gov (United States)

    1980-10-21

    porning Is that of a professional soldier--as oric who will be m the thick of things i1 this currently tentative international order falls -pAprt. In...But the bubble burst in 1973. In a somewhat politit.lly Lue’trived shtortfoll, tie producing Arab states shut off oil exports--draimiatizing Ituw...missions In 14 dayb during the Arab -Israeli conflict--hauling 13,000 tons of military equipment and supphes to Egypt, Syria and !-aq. t They developed

  15. Engines/Fuels Workshop, 6-8 December 1982, San Antonio, Texas.

    Science.gov (United States)

    1982-01-01

    occupies approximately 40% of cooled diesels of exclusive military design and the under - armor hull volume. Of that, only a use. The second is the range of...be placed largely,or better yet, exelusively under armor *: protection. Thus, the more fuel needed for a , • • ’ v’ v• i given range requirement, the

  16. Environmental Assessment: San Antonio Creek Restoration at Vandenberg Air Force Base, California

    Science.gov (United States)

    2008-09-08

    biological hazards including vegetation (i.e. poison oak and stinging nettle ), animals (i.e. insects , spiders, and snakes), and disease vectors (i.e...acre. Native grasses and herbs such as giant wild rye (Leymus condensatus), and stinging nettle (Urtica dioica) dominate this vegetation type...mud, and unstable ground. Biological hazards such as animals ( insects , spiders, and snakes), and disease vectors (ticks and rodents). 3.6.3

  17. Wild Beginnings: How a San Antonio Initiative Instills the Love of Nature in Young Children

    Science.gov (United States)

    Kharod, Deepti; Arreguín-Anderson, Maria G.

    2015-01-01

    This paper describes an environmental education initiative called Starting out Wild (SoW) designed for toddlers and their caretakers. The program, developed by staff and volunteers of a city parks department, engages children ages 1-3 and their parents and caretakers through outdoor learning experiences. We suggest that environmental education…

  18. Weapons Storage Area Survey of Munitions Storage Igloos at Medina Annex, San Antonio, Texas

    Science.gov (United States)

    2013-11-13

    Attachment 2 Contaminants of Concern 1. General. Early nuclear weapons used polonium -beryllium (Po-Be) initiators to generate neutrons during the... foods . b. Compositions. Figure 2-1 is a histogram of key isotopic mixtures of uranium by mass. The composition for DU is a moderately depleted...200 199 230 210 255 286 Min = 171 6 258 193 243 199 188 196 171 212 190 210 207 223 203 211 214 237 257 Median = 209 A B C D E F G H I J K L M N O P Q

  19. Transducer Workshop (16th) Held in San Antonio, Texas on June 18-20, 1991

    Science.gov (United States)

    1991-06-01

    34 he from 1936-40 he was Instructor in EE at Armour says even of the very first gage which Dat- (now Illinois) Institute of Technology in wyler bonded...wirebonds are draped over a dam separating the sensor from the conformal coat- Compared to the first generation sensor de- ing used for structural...base. (No discussion will prevent flow of the coating onto the sensor. be included on the electrical stability of circuit Draping the sensor lead wires

  20. Randolph AFB, San Antonio, Texas. Revised Uniform Summary of Surface Weather Observations (RUSSWO)

    Science.gov (United States)

    1976-03-19

    S700 62.0 70.9 73t5 74.9 76,1 76.3 76.7 77.0 77.1 77.4 77.6 77.6 7 8.u 78.2 78,5 78.8 >_ 600 62.4 72.0 74.8 76,4 77.8 77.8e9I7 78.9 7 795 7 L; 8o r, n...8 .1a - 5 6 8._5 6 8 . 9 -9 8 ,,8 &196.o8 90 1.3 80,0 61,,U 81.6 e2 2 82.4 R2#7 2.9 82.8 32,9 83oU 83911 3.1 83.-1 83,1 83:21 S700 74.6 $4.8 86,u...93.0 9398 91 .4 94.8 9 4,9_ 9_ 5.5 95.5 95 _59 955I._9 A 95.595595.5 S700 88.2 93,5 94,3 9,.9 95o4 95.5 9L." 96.3 96,3 96.4 96.4! 96,4 96.4 96.4 96,4 96

  1. Workload Trend Analysis for the Military Graduate Medical Education Program in San Antonio

    Science.gov (United States)

    2005-05-25

    determining the number of residents the existing casemix can sustain. Further, the utilization of established residency training program assessment tools...care will be reported and discussed in this report. Measuring the relative proportion of the existing casemix by age group will allow the GME...the individual program directors in balancing unpredictable mission requirements against the appropriate number of residents that the current casemix

  2. A Qualitative Study of Affordability: Virginia and San Antonio Class Programs

    Science.gov (United States)

    2014-06-01

    that actual costs and operational tempos resemble original assumptions is the most uncertain aspect of sustainment costs. Operators must respond to a...SSN 774 through SSN 787; this represents 47% of the total inventory, a typical variation for ships from the acquisition standard of 10%. Even... Goldberg , M., … MacKinnon, M. (1994). The U.S. submarine production base (MR-456-OSD). Santa Monica, CA: RAND. Blickstein, I. United States. Department

  3. 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.

  4. 77 FR 70891 - Safety Zone; Bay Bridge Construction, San Francisco Bay, San Francisco, CA

    Science.gov (United States)

    2012-11-28

    ... using a self-anchoring suspension system that requires frequent installation and removal of false work... voluntary consensus standards. 14. Environment We have analyzed this rule under Department of Homeland...

  5. Mex Bay

    African Journals Online (AJOL)

    user

    2015-02-23

    Feb 23, 2015 ... surveys to assess the vulnerability of the most important physical and eutrophication parameters along. El- Mex Bay coast. As a result of increasing population and industrial development, poorly untreated industrial waste, domestic sewage, shipping industry and agricultural runoff are being released to the.

  6. Cineclube Antonio das Mortes and its independent film production

    Directory of Open Access Journals (Sweden)

    Marina da Costa Campos

    2014-07-01

    Full Text Available This article analysis the production of experimental films made by Cineclube Antonio das Mortes (CAM in 1980, in Goiania, Through the term "independent film". This work is an initial study, therefore, it’s intended, first, to discuss the various conceptions given to “independent cinema” in Brazilian cinema history, from the late 1940s until 1980. Then, this work will try to understand how this production of this Cineclube approaches or moves away from the different conceptions that this term has acquired over the decades.

  7. L'uomo inquieto. Identità e alterità nell'opera di Antonio Tabucchi

    DEFF Research Database (Denmark)

    Lausten, Pia Schwarz

    Italiensk litteratur 1980-2000, Gianni Vattimo, Michail Bachtin, Identitetsproblematik i Antonio Tabucchis forfatterskab, subjektivitetsforståelse......Italiensk litteratur 1980-2000, Gianni Vattimo, Michail Bachtin, Identitetsproblematik i Antonio Tabucchis forfatterskab, subjektivitetsforståelse...

  8. Stereo photo series for quantifying natural fuels.Volume XIII: grasslands, shrublands, oak-bay woodlands, and eucalyptus forests in the East Bay of California.

    Science.gov (United States)

    Clinton S. Wright; Robert E. Vihnanek

    2014-01-01

    Four series of photographs display a range of natural conditions and fuel loadings for grassland, shrubland, oak-bay woodland, and eucalyptus forest ecosystems on the eastern slopes of the San Francisco Bay area of California. Each group of photos includes inventory information summarizing vegetation composition, structure, and loading; woody material loading and...

  9. Reflections on Michael Hardt and Antonio Negri’s Book “Assembly”

    Directory of Open Access Journals (Sweden)

    Christian Fuchs

    2017-10-01

    Full Text Available This contribution presents reflections on Michael Hardt and Antonio Negri’s book “Assembly” (2017, Oxford: Oxford University Press, ISBN 978-0190677961. Keywords: assembly, Michael Hardt, Antonio Negri, multitude, common, entrepreneurship of the multitude, the new Prince, digital capitalism, digital assemblage, neoliberalism, finance

  10. 78 FR 48046 - Safety Zone; Kuoni Destination Management Fireworks; San Diego, CA

    Science.gov (United States)

    2013-08-07

    ...-AA00 Safety Zone; Kuoni Destination Management Fireworks; San Diego, CA AGENCY: Coast Guard, DHS... waters of the San Diego Bay in support of the Kuoni Destination Management Fireworks Display on August 6... Guard's ability to protect the public from the potential hazards associated with fireworks displays...

  11. 78 FR 58878 - Safety Zone; San Diego Shark Fest Swim; San Diego Bay, San Diego, CA

    Science.gov (United States)

    2013-09-25

    ... Act (APA) (5 U.S.C. 553(b)). This provision authorizes an agency to issue a rule without prior notice... Security Management Directive 023-01 and Commandant Instruction M16475.lD, which guide the Coast Guard in...

  12. Lithostratigraphic, borehole-geophysical, hydrogeologic, and hydrochemical data from the East Bay Plain, Alameda County, California

    Science.gov (United States)

    Sneed, Michelle; Orlando, Patricia v.P.; Borchers, James W.; Everett, Rhett; Solt, Michael; McGann, Mary; Lowers, Heather; Mahan, Shannon

    2015-01-01

    The U.S. Geological Survey, in cooperation with the East Bay Municipal Utility District, carried out an investigation of aquifer-system deformation associated with groundwater-level changes at the Bayside Groundwater Project near the modern San Francisco Bay shore in San Lorenzo, California. As a part of the Bayside Groundwater Project, East Bay Municipal Utility District proposed an aquifer storage and recovery program for 1 million gallons of water per day. The potential for aquifer-system compaction and expansion, and related subsidence, uplift, or both, resulting from aquifer storage and recovery activities were investigated and monitored in the Bayside Groundwater Project. In addition, baseline analysis of groundwater and substrata properties were performed to assess the potential effect of such activities. Chemical and physical data, obtained from the subsurface at four sites on the east side of San Francisco Bay in the San Lorenzo and San Leandro areas of the East Bay Plain, Alameda County, California, were collected during the study. The results of the study were provided to the East Bay Municipal Utility District and other agencies to evaluate the chemical and mechanical responses of aquifers underlying the East Bay Plain to the future injection and recovery of imported water from the Sierra Nevada of California.

  13. El anhelo metafísico de Antonio Machado

    Directory of Open Access Journals (Sweden)

    Carlos Llano Cifuentes

    2013-11-01

    Full Text Available In Antonio Machado's poetry, a dissatisfied agnosticism appears; that is, a kind of agnosticism which wants to quit being such, an agnosticism with metaphysical longings. Machado knows that the absence of trascendence does not offer peacefulness, but tediousness and resignation against the changing reality. Being lacks the plenitude it once had and, in this sense, there exists in Machado a double way to understand reality: longing for what was and confirmation of the present. All this generates a vacuum in the human being, a thirst of trascendence not satisfied and, at the sme time, hope as longing of trascendence which can only be expressed in metaphysics and poetry. Machado's account on trascendence does not exclude immanence. It is found in and from the self, for itself and in other, and even in the absolutely other.

  14. Landscape concept in photography: from Luigi Ghirri to Antonio Ottomanelli

    Directory of Open Access Journals (Sweden)

    Teodora Malavenda

    2014-05-01

    Full Text Available In the 80s of the last century the Italian photography, like other art forms, reflected the political, economic and cultural changes of the Nation. It was the time of a new documentary photography that investigated the transformation of the urban areas. Within this process the landscape was the subject of a new interpretation. In 2013 this process of documentation was worked out again, but in a modern way, by Antonio Ottomanelli. In his project "Collateral Landscape", he took pictures in different cities of the world such as Kabul, Baghdad, Sadr City, Herat, Dokan, New York, Gaza City. Distant places and only apparently different from each other. In fact, all of them have been destroyed by war or, in the case of New York, have been target of a terrorist attack.

  15. Antonio José Ponte: el espacio como texto

    Directory of Open Access Journals (Sweden)

    María Guadalupe Silva

    2014-04-01

    This essay examines Antonio José Ponte’s tale "Un arte de hacer ruinas" (An Art of making ruins from the perspective of its narrative strategies. Considering the general structure of the book, in which this tale holds a central place, the essay inquires into the meanings of the very notion of "center" in Ponte’s literary project. Since the structuration of space, in particular, urban space, which is the first political space, is a matter of permanent reflection in his work, here I offer a reading of the allegorical "engineering" of the tale, establishing relations with other critical texts by Ponte which defies the metaphysics of Cuban nationalism and the centralizing ideology of the Estate.

  16. Miguel Antonio Caro, el Banco Nacional y el Estado

    Directory of Open Access Journals (Sweden)

    Salomón Kalmanovitz

    1999-09-01

    Full Text Available La Regeneración fue el movimiento político y Miguel Antonio Caro el ideólogo que hicieron que Colombia retornara a la matriz institucional centralizada legada por los españoles, en reacción a la dirección liberal y federalista que pretendió orientarla por la senda del desarrollo capitalista, vía su integración al mercado mundial. Esta fue una tendencia continental, de acuerdo con Douglass North, aún en países donde los liberales ganaron las guerras civiles del siglo XIX (North, 134-135. En este ensayo se trata de analizar el pensamiento económico de Caro y más precisamente sus percepciones sobre la banca central, como parte integral de su concepción del Estado que terminaron por imponerse para la Colombia del siglo XX.

  17. Juan Antonio Rubio appointed as Director-General of CIEMAT

    CERN Multimedia

    2004-01-01

    Juan Antonio Rubio, Head of CERN's ETT unit (Education and Technology Transfer) has been appointed by the Spanish Ministry of Education and Science as the Director General of the Research Centre for Energy, Environment and Technology, CIEMAT. Dr Rubio's career began at the Spanish Nuclear Energy Commission where he held the posts of Investigator, Head of the High Energy Group and Head of Nuclear Physics and High Energy Division. Later, he was named Director of the Department of Basic Investigation and Scientific Director of the CIEMAT. In 1987 he joined CERN as Scientific Adviser to the Director General and Group Leader of the Scientific Assessment Group. Up to now, Dr Rubio has been the Head of the ETT unit, as well as Coordinator for Latin America and Commissioner for the 50th Anniversary of the Organization. He was born on 4 June 1944 in Madrid, and holds a Doctorate in Physical Sciences from the Universidad Complutense de Madrid.

  18. Antonio Boggeri. Considerazioni su un protagonista della grafica italiana

    Directory of Open Access Journals (Sweden)

    Camilla Chiappini

    2012-01-01

    Full Text Available Antonio Boggeri is often remembered in the history of graphics only as the Studio Boggeri’s holder. Indeed he is one of the most important figures of Italian advertising graphics and this not for the works he materially made in this field but for his centrality in the Studio he created: in fact he was the unifying element in it among artists of different personality and sensibility.This article does not pretend to explain in a comprehensive manner his importance but it wants to represent a starting point in a research that reconsiders all round Boggeri. Not only, therefore, for his central role in the Studio, but even for his important contribution as a writer and as a photographer, compensating, in part, the lack of works that fully analyze his figure.

  19. Coal exploration in the Alto San Jorge area, Cordoba Department. Exploracion de carbones en el Ato San Jorge, Departamento de Cordoba

    Energy Technology Data Exchange (ETDEWEB)

    Ospina, L H; Oquendo, G G [Geominas Ltda, Medellin (Colombia)

    1989-01-01

    A Mining Feasibility Study in the Area of Alto San Jorge, Department of Cordoba, Colombia, was commissioned by CARBOCOL S.A. to the Consortium Geominas-NACI. An area of 800 Ka2 was explored to define surface mining possibilities within two subareas referred to as Alto San Jorge and San Pedro Ure. Rocks of Cretaceous, Tertiary and Quaternary age crop out in the zone. In the subarea Alto San Jorge the principal structure is a syncline with a south-north direction. The San Pedro Ure subarea is formed by undulations with flanks of low dip, the most important being the San Antonio Syncline because it contains the mining block. The geological study of the surface demonstrated the existence of coal in the Oligocene Cienaga de Oro Formation and the Niocene Cerrito Formation, with potential resources of 6.3 billion tons. The subsequent exploration of the subsoil, with 20.618 m of drilling, permitted determination of demonstrated reserves in the order of 2.9 billion tons within two areas. In the sector selected for the mine plan, in the area of San Pedro-Puerto Libertador, 7.791 m of drilling was accomplished to define a demonstrated reserve of 515 million tons of coal down to a depth of 200. The combustible type coal has 5.000 cal/g. Complete mining schedules were developed at the prefeasibility level for two surface mines with productions of 1.5 MMTY and 4 MMTY. 9 figs., 3 tabs., 28 refs.

  20. Nii kauge, kuid nii omane Brasiilia / Antonio Claudio Carvalho ; interv. Reet Varblane

    Index Scriptorium Estoniae

    Carvalho, Antonio Claudio

    2005-01-01

    Vestlus brasiilia kunstniku Antonio Claudio Carvalhoga 15. X, päeval pärast tema näituse avamist Kunstihoone galeriis. Kunstist, kunstnikest, endast, oma loomingust, kunsti tähendusest praeguses Brasiilias jm.

  1. Mito e le visioni musicali di Antonio Buero Vallejo

    Directory of Open Access Journals (Sweden)

    Giada Ferrante

    2012-01-01

    Full Text Available Nel corso della sua attività drammaturgica Antonio Buero Vallejo si confrontò con la scrittura di un unico «libreto para una ópera», intitolato Mito. Il libretto non fu mai musicato, ma venne pubblicato nel 1968 sulle pagine della rivista Primer Acto, preceduto da una breve introduzione dell’autore. Nel 1976, Mito apparve in un’edizione Espasa- Calpe curata da Francisco García Pavón, inseme a La doble historia del Doctor Valmy. Basandosi su quest’ultima pubblicazione, fedele al testo originale, l’articolo indaga la scrittura di Buero, attraverso una sistematica analisi delle didascalie e della costruzione dialogica dell’opera, evidenziando i numerosi suggerimenti musicali del drammaturgo. Dopo una breve introduzione all’opera, si esaminano nel dettaglio gli interventi dell’autore, cercando di rintracciare i diversi ambiti musicali entro cui si muove Buero, per poi arrivare a mostrare la possibile alternanza di un sistema musicale tonale e un sistema musicale dodecafonico. La scrittura musicale sottesa a «Mito» testimonia della spiccata sensibilità del drammaturgo, permettendo di affermare che Buero concepì il testo in forma musicata, fin dalle prime fasi della sua stesura, sostituendosi, in molti casi, all’eventuale compositore, fino a proporre originali e suggestive soluzioni sonore che questo articolo si prefigge di delineare. During his dramatic activity, Antonio Buero Vallejo measured himself with the writing of a single «libreto para una ópera», entitled Mito. This libretto was never set to music, but was published in 1968 in Primer Acto, preceded by a brief introduction of the author. In 1976 Mito appeared in an Espasa-Calpe volume, edited by Francisco García Pavón, together with La doble historia del Doctor Valmy. Based on this edition, true to the original text, the article investigates Buero’s writing through a methodical analysis of the stage directions and the dialogical construction of the text

  2. El último urbanismo de Antonio Bonet: el poblado SOS (1970

    Directory of Open Access Journals (Sweden)

    Juan Fernando Ródenas García

    2018-04-01

    Full Text Available El poblado SOS de Aldeas Infantiles, Sant Feliu de Codines, Barcelona (1970, junto al poblado Hifrensa (realizado y los planes urbanísticos de Prat I y II (no realizados, constituyen los últimos conjuntos urbanísticos de cierto calado proyectados por Antonio Bonet, si exceptuamos su producción turística. Bonet plantea un conjunto residencial para alojar a niños huérfanos con equipamientos comunitarios educacionales y deportivos. Bonet recrea en el poblado SOS la atmósfera, a escala humana, que se respira en aquellos pueblos que aparecen fotografiados en el número 18 (1935 de la revista del GATEPAC, AC Documentos de Actividad Contemporánea, dedicado a la arquitectura popular. Pabellones encalados, bóvedas, porches, patios, muros y plataformas de piedra dispuestas como bancales agrícolas, constituyen los elementos que construyen el paisaje de un poblado de trazo moderno y formas arcaicas. Se propone el análisis de una obra inédita que, aunque no se llevó a cabo, expresa la singular lectura del autor de las condiciones de habitabilidad para niños huérfanos, del paisaje, y al mismo tiempo, la obra condensa la experiencia de Bonet como urbanista ya experimentado que en los años 70 pone a prueba con perspectiva histórica su credo teórico fundamental: la Carta de Atenas.

  3. Social media, publicidad y empresa. Entrevista a Antonio Fumero

    Directory of Open Access Journals (Sweden)

    Ana Mª Belmonte Jiménez

    2012-04-01

    Full Text Available Antonio Fumero es Ingeniero de Telecomunicación y MBA por la Universidad Politécnica de Madrid (UPM. Especialista en la Gestión de la Tecnología e Innovación, trabajó dos años en la Unidad de Desarrollo Tecnológico e Innovación de BBVA como asesor de Nuevas Tecnologías. Actualmente desarrolla su actividad como investigador en la UPM, colaborando con la Cátedra Telefónica para Internet de Nueva Generación y el Departamento de Ingeniería de Sistemas Telemáticos (DIT en la dinamización y coordinación de un grupo de investigadores en Redes y Software Social (iRSS. Desempeña labores de diseminación, asesoría y análisis como experto para distintas organizaciones corporativas e institucionales. Recientemente ha creado su propia empresa, Win Win consultores. También es community manager de Color-Uiris y senior consultant de TalentBrokers.

  4. Maidservant as muse: The dramatic reinvention of Antonio Canova

    Directory of Open Access Journals (Sweden)

    Christina Ferando

    2010-12-01

    Full Text Available In the mid-1870s, the playwright Lodovico Muratori (1834-1919 wrote a play based on the life of the sculptor, Antonio Canova, that focused on a fictional, unconsummated passion between Canova and his housekeeper, Luigia Giuli. This play, published by the Milanese editor Carlo Barbini concurrently with several plays about famous Italian artists, including Michelangelo, Raphael, and Tintoretto, emphasized Canova’s connection to these great masters, in particular his role as both artist and lover. By examining the way political and artistic values changed in Italy over the course of the century, this paper arges that Muratori’s insistent repetition of the trope of ‘Luigia as muse’ is an implicit critique of neoclassicism. Artistic inspiration is disengaged from imitation and the rote act of copying and located instead in the very personal and subjective emotions of the artist. By the late nineteenth century, in order to maintain the validity of an otherwise outmoded style, neoclassicism and its suffocating image of repetition were necessarily recast to fit the political, sociological and artistic developments of the time.

  5. Telegraph Canyon Creek, City of Chula Vista, San Diego County, California. Detailed Report for Flood Control. Volume 1. Main Report.

    Science.gov (United States)

    1983-07-01

    SECURITY CLASS. (of chi* report) Los Angeles District, Corps of Engineers Ucasfe P.O. Box 2711, Los Angeles, CA 90053 15&. DEL SI F1CATION/OWNGRAOI...greater potential for the possible occurrence of a large earthquake include the Whittier-Elsinore, Agua Caliente, San Jacinto, and the San Andreas...about 900,000 motor vehicles used within the county. 2.20 Air contaminants monitored within the San Diego Bay air basin include carbon monoxide (CO

  6. Thatcher Bay, Washington, Nearshore Restoration Assessment

    Science.gov (United States)

    Breems, Joel; Wyllie-Echeverria, Sandy; Grossman, Eric E.; Elliott, Joel

    2009-01-01

    The San Juan Archipelago, located at the confluence of the Puget Sound, the Straits of Juan de Fuca in Washington State, and the Straits of Georgia, British Columbia, Canada, provides essential nearshore habitat for diverse salmonid, forage fish, and bird populations. With 408 miles of coastline, the San Juan Islands provide a significant portion of the available nearshore habitat for the greater Puget Sound and are an essential part of the regional efforts to restore Puget Sound (Puget Sound Shared Strategy 2005). The nearshore areas of the San Juan Islands provide a critical link between the terrestrial and marine environments. For this reason the focus on restoration and conservation of nearshore habitat in the San Juan Islands is of paramount importance. Wood-waste was a common by-product of historical lumber-milling operations. To date, relatively little attention has been given to the impact of historical lumber-milling operations in the San Juan Archipelago. Thatcher Bay, on Blakely Island, located near the east edge of the archipelago, is presented here as a case study on the restoration potential for a wood-waste contaminated nearshore area. Case study components include (1) a brief discussion of the history of milling operations. (2) an estimate of the location and amount of the current distribution of wood-waste at the site, (3) a preliminary examination of the impacts of wood-waste on benthic flora and fauna at the site, and (4) the presentation of several restoration alternatives for the site. The history of milling activity in Thatcher Bay began in 1879 with the construction of a mill in the southeastern part of the bay. Milling activity continued for more than 60 years, until the mill closed in 1942. Currently, the primary evidence of the historical milling operations is the presence of approximately 5,000 yd3 of wood-waste contaminated sediments. The distribution and thickness of residual wood-waste at the site was determined by using sediment

  7. 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.

  8. Det 'svage' subjekt. En undersøgelse af det litterære subjekts forandring i Antonio Tabucchis og Gianni Celatis forfatterskaber

    DEFF Research Database (Denmark)

    Lausten, Pia Schwarz

    Italiensk litteratur efter 1980; postmodernisme; subjektsforståelse; Antonio Tabucchi; Gianni Celati; Michail Bachtin; Gianni Vattimo......Italiensk litteratur efter 1980; postmodernisme; subjektsforståelse; Antonio Tabucchi; Gianni Celati; Michail Bachtin; Gianni Vattimo...

  9. 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...

  10. 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.

  11. Technical proposal on the treatment of the influent of the Jose Antonio Alzate dam using aerobic pond system; Propuesta tecnica sobre el tratamiento del influente de la presa Jose Antonio Alzate a traves un sistema lagunar aerobio

    Energy Technology Data Exchange (ETDEWEB)

    Rosas de Alba, S.G. [Instituto Tecnologico de Toluca, Metepec, Estado de Mexico (Mexico)]. E-mail: sergio.rosas01@cfe.gob.mx; Barcelo Quintal, I.D.; Bussy Beaurain, A.L.; lopez Galvan, E. [Universidad Autonoma Metropolitana, Unidad Azcapotzalco (Mexico)]. E-mail: idbq@correo.azc.uam.mx; leemp@correo.azc.uam.mx; loge@correo.azc.uam.mx

    2010-01-15

    In Mexico, discharge of waste water not treated is a common problem; this is the case of the Lerma river, where the original clean water contribution of the Almoloya-Lerma-San Bartolo timber-roof system, located in the valley of Toluca, State of Mexico, was replaced by the wastewater of the valley. The attempts to clean the water before their spill have been unfruitful and this has caused the present anaerobic conditions of the river in its entire route including the first receiving stage that is the Jose Antonio Alzate Dam (PJAA), becoming a potential source of diseases and a useless water body. In this work we evaluate the treatment efficiency of experimental waste water pond system. The treatment system was constructed with 5 screens which formed 6 internal channels and it had an operation in continuous form by 26 weeks, providing it with continuously polluted water of the Lerma river. We found that the efficiency of reduction of the organic matter reported as BOD, was 83% and it is carried out in the first channel after 7 days of hydraulic retention verifying that the channels do not work like lagoons in series. With the collected data we calculated, through the application of design equations, the factor of decay of organic matter k and the number of dispersion d, specific for the type of treatment and environmental conditions of the site. The required surface of treatment calculated to reach the efficiency of reduction of the DOD5 obtained experimentally. Thus, a surface of: 1 281.6 hectares distributed in 13 lagoons that can deal with a volume 8646.70 m{sup 3}/h was determined. Since this was a bigger surface than that of the dam, the available area was evaluated to make a proposal closer to reallity. [Spanish] La descarga de aguas residuales a los sistemas acuaticos, sin previo tratamiento, es un problema generalizado en Mexico; como es el caso del rio Lerma en donde se sustituyo el aporte de agua limpia proveniente del sistema lagunar Almoloya-Lerma-San

  12. Review of suspended sediment in lower South Bay relevant to light attenuation and phytoplankton blooms

    Science.gov (United States)

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

    2016-01-01

    Lower South Bay (LSB), a shallow subembayment of San Francisco Bay (SFB), is situated south of the Dumbarton Bridge, and is surrounded by, and interconnected with, a network of sloughs, marshes, and former salt ponds undergoing restoration (Figure ES.1). LSB receives 120 million gallons per day of treated wastewater effluent from three publicly owned treatment works (POTWs) that service San Jose and the densely populated surrounding region. During the dry season, when flows from creeks and streams are at their minimum, POTW effluent comprises the majority of freshwater flow to Lower South Bay. Although LSB has a large tidal prism, it experiences limited net exchange with the surrounding Bay, because much of the water that leaves on ebb tides returns during the subsequent flood tides. The limited exchange leads to distinctly different biogeochemical conditions in LSB compared to other SFB subembayments, including LSB having the highest nutrient concentrations and highest phytoplankton biomass.

  13. Sustainability of coastal resource use in San Quintin, Mexico.

    Science.gov (United States)

    Aguirre-Muñoz, A; Buddemeier, R W; Camacho-Ibar, V; Carriquiry, J D; Ibarra-Obando, S E; Massey, B W; Smith, S V; Wulff, F

    2001-05-01

    San Quintin, Mexico, provides a useful site for integrated analyses of material fluxes and socioeconomic constraints in a geographically isolated system. Natural resource utilization on the land is dominated by groundwater exploitation for cultivation of horticulture crops (primarily tomatoes). Irrigation exceeds water recharge minus export by a factor of 6. Resource utilization in the bay is dominated by oyster culture; food for the oysters is provided by tidal exchange of bay and ocean water. Consideration of oyster respiration and system respiration suggests that the present level of aquaculture is about 40% of the sustainable level. A "physical unsustainability index" (PhUI) was developed to measure the proportional departure of utilization of the most limiting resource for sustainability: 6 on land; 0.4 in the bay. Based on PhUI and measures of economic development, we conclude that aquaculture is more viable than agriculture.

  14. Conference Proceedings: Aircraft Gear and Bearing Tribological Systems Held in San Antonio, Texas on 22-26 April 1985.

    Science.gov (United States)

    1986-02-01

    requirements) are presented in Table IT. The selected candidate base oil was a blend of commercially available neopentyl polyol esters. It was selected...engine validation consisted of: 1. a neopentyl polyol ester blend 2. a deposit inhibitor (Ref. 7) 3. a heterocyclic amine oxidation inhibitor 4...lutely required. The use of a glycol or a synthetic hydrocarbon (polyalphaolefin (PAO)l based fluid has been suggested as a possible basestock material for

  15. Identifying agroecological mixed farming strategies for local conditions in San Antonio de Los Baños, Cuba

    NARCIS (Netherlands)

    Monzote, F.R.F.; Bello, R.; Alvarex, A.; Hernández, A.; Lantinga, E.A.; Keulen, van H.

    2012-01-01

    Building on previous research at the experimental and national scales, this study was carried out at the local scale over a four-year period on three farms of reference: one specialized dairy farm ‘Vaquería 10’ (33.7 ha) and two mixed farms, ‘Remedio’ (9.4 ha) and ‘La Sarita’ (47 ha). All three

  16. Proceedings of the Structural Integrity Program Conference. Held in San Antonio, Texas on 29 November-1 December 1988

    Science.gov (United States)

    1989-05-01

    normal wear and tear (brakes, tires, etc.) and extended time between subsystem replacement or repair. - Normal aircraft horizontal takeoff and...T76 Dassault Test Program Inconel 718 2214-T6 Rockwell B-1 B Attachment Links 13-8 PH 7075-T73 International Pratt & Whitney TF-33 Compressor AMS...operational temperature range of 20°F to 100°F lead to the following final damping designs: 625 * 0.004 inch 3M ISD113 and 0.012 inch aluminum

  17. Proceedings of Users’ Stress Workshop (8th) Held San Antonio, Texas on September 24 - 27, 1991

    Science.gov (United States)

    1991-09-01

    children reported lower self esteem and coping than those of older children . With parental absence, the younger children ...soldier during deployment) and having Ogood" children (i.e., ones that don’t stress the remaining parent ). OOS/ S research confirmed the importance of these...benefits and Employee Assistance Programs. They are seen in health-promoting benefits like flex shifts for parents , maternity and paternity leives,

  18. Proceedings of the USAF Structural Integrity Program Conference Held in 11-13 December 1990 in San Antonio, Texas

    Science.gov (United States)

    1991-08-01

    z o wIx 2W WCOZ F-om 0 0 . zu C, 0a <o-z - w c0 -0 CL-cr. a: QI 0~~ Wo I. _ Oo () cr cr. 0< Oz30 i-1*CC0 *lW 0 w a. Cf461 aI~ ɘ w0 WLJW CfOz 0ɘ wwW...in the rotor bore, the sec- ond, a surface crack at the cone- web junction. Typical florescent--penetrate-inspection capability (FPI) is finding a 35 by...this reason, automatic or web , wing ctr. section, stn. eveni computer controlled shot 1000" carry the following peer ing is to be preferred "Repair

  19. Proceedings of the Annual Conference of the Military Testing Association (19th), 17-21 October 1977, San Antonio, Texas

    Science.gov (United States)

    1979-11-01

    to-?ir kills, especially since we will probably be atle to field only a relatively small number of fighter pilots in future wars. Fighter pilots have...Education and Training, Information, And Legal, too many colonel positlons were allocated. Overall, many jobs wer found to be undergraded, especially at the...t preparing the final eppmntice progress/status report, 4e avy C :-vs educacion specialist will regard previous work experience as distri±xtnd

  20. Air Force Personalized Medicine Program Panel: Representative Research at the 59th Medical Wing San Antonio Military Medical Center

    Science.gov (United States)

    2016-05-18

    DNA used to predict individual’s re~nse to cardiac therapeutics &Provide universa l standard sample and ampl icon preparat ion protocol; point of care...coordination of patient evacuation Adverse Childhood Experience Serotonin Transporters and Telomeres: A Gene Environmental Interaction Study of the...Risk of PTSD in Soldiers Biomarkers for Mental Illness and Recovery using Sleep as a Mediator: A Randomized Controlled Trial Characterization of the

  1. Test Review: D. Wechsler "Wechsler Individual Achievement Test-Third Edition." San Antonio, TX--NCS Pearson, 2009

    Science.gov (United States)

    McCrimmon, Adam W.; Climie, Emma A.

    2011-01-01

    This article reviews the "Wechsler Individual Achievement Test-Third Edition" (WIAT-III), a newly updated individual measure of academic achievement for students in Pre-Kindergarten through Grade 12 (age 4 years, 0 months to 19 years, 11 months). Suitable for use in educational, clinical, and research settings, the stated purposes of the WIAT-III…

  2. Test Review: Wechsler, D., & Naglieri, J.A. (2006). "Wechsler Nonverbal Scale of Ability". San Antonio, TX--Harcourt Assessment

    Science.gov (United States)

    Massa, Idalia; Rivera, Vivina

    2009-01-01

    This article provides a review of the Wechsler Nonverbal Scale of Ability (WNV), a general cognitive ability assessment tool for individuals' aged 4 year 0 months through 21 years 11 months with English language and/or communicative limitations. The test targets a population whose performance on intelligence batteries might be compromised by…

  3. Test Review: D. Wechsler "Wechsler Individual Achievement Test" (3rd ed.). San Antonio, Texas--Pearson, 2009

    Science.gov (United States)

    Vaughan-Jensen, Jessica; Adame, Cindy; McLean, Lauren; Gamez, Brenda

    2011-01-01

    This article reviews "Wechsler Individual Achievement Test-Third Edition" (WIAT-III), which is designed to assess students' skills in listening, speaking, reading, writing, and mathematics. The test can identify an individual's strengths and weaknesses, assist professionals who are determining whether a student is eligible for special…

  4. AMEDD Clinical Psychology Short Course Held at Brooke Army Medical Center, San Antonio, Texas, 5-9 June 1991

    Science.gov (United States)

    1991-06-01

    You might find some of the words nasty; you might find some of the words silly. Some of the names I’ve heard are vagina , boo-boo, honey pot or just...what has happened. The mouth, anus and vagina can all be cut open to accommodate a penis, finger, sexual aid, vibrator, or whatever may have been...member of a team rather than isolating oneself because of the myth that one must solve his/her problems alone. Phase III takes three hours and includes

  5. Factores asociados con el proceso de salud y enfermedad en San Antonio (Catamarca, Argentina: un enfoque antropológico

    Directory of Open Access Journals (Sweden)

    Bárbara Martínez

    2016-01-01

    Full Text Available Objetivo: Identificar los procesos de salud y enfermedad entre los pobladores de El Cajón (Catamarca, Argentina y su vinculación con la biomedicina. Asimismo, estudiar las ar - ticulaciones entre la biomedicina y el sistema de salud tradicional. Materiales y métodos: Investigación cualitativa, mediante un abordaje etnográfico en el que la observación participante, la corresidencia y las entrevistas abiertas de sesiones múltiples cumplen un rol primordial. La pesquisa se ha centrado en los pobladores locales que regularmente asisten a la posta sanitaria, los enfermeros, los agentes sanitarios y los miembros del equipo de salud itinerante. La población total del lugar es aproximadamente 235 habitantes. Resultados: Se ha constatado que los procesos de salud y enfermedad no se limitan al cuerpo humano, sino que también en ellos intervienen el paisaje y los seres que lo pueblan. Se ha identificado que en la resolución de numerosas patologías resulta central la figura del especialista ritual. Se ha determinado que la gente valora y utiliza la biomedicina, aunque la asistencia a la institución hospitalaria suele ser rehuida. Conclusiones: Se ha identificado un uso combinado de ambos sistemas. En él influyen las valoraciones de las personas sobre la enfermedad de que se trate, pero también otros factores como la distancia hasta el centro asistencial y las relaciones interpersonales con los profe - sionales de la salud. Se resalta la relevancia del enfoque cualitativo para dar cuenta de las especificidades de las categorías locales, que resultan esquivas para un abordaje construido a partir de conceptos derivados del dualismo cartesiano.

  6. Proceedings of the World Congress on Medical Physics and Biomedical Engineering (San Antonio, Texas, August 6-12, 1988).

    Science.gov (United States)

    Clark, John W., Ed.; And Others

    1988-01-01

    This document contains the proceedings of a joint meeting of the International Federation for Medical and Biological Engineering and the International Organization for Medical Physics. Participants from over 50 countries were in attendance. The theme of the program, "Challenges for the Year 2000," was a reminder of the challenges which confront…

  7. Vector Surveillance to Determine Species Composition and Occurrence of Trypanosoma cruzi Infection at Three Military Installations in San Antonio, Texas

    Science.gov (United States)

    2012-01-01

    the MWD Center have exhibited multiple clinical signs. Canines affected with Chagas disease develop either acute or A B Figure 3. Dog kennel habitat...and dilation . The result is a bilat- eral enlarged heart with fl accid thin walls that exhibit abnormal electrical impulses and arrhythmias on an...electrocardiograph, along with possible respiratory dis- tress. These cases can often be confused with chronic dilative cardiomyopathy observed in other

  8. Relation of water chemistry of the Edwards aquifer to hydrogeology and land use, San Antonio Region, Texas

    Science.gov (United States)

    Buszka, Paul M.

    1987-01-01

    Water-chemistry data from the Edwards aquifer for 1976-85, consisting of nearly 1,500 chemical analyses from 280 wells and 3 springs, were used to statistically evaluate relations among ground-water chemistry, hydrogeology, and land use. Five land uses associated with sampled wells were classified on the basis of published information and field surveys. Four major subareas of the aquifer were defined to reflect the relative susceptibility of ground water to contamination originating from human activities using hydrogeologic and tritium data.

  9. Proceedings of IEEE International Symposium on Information Theory Held in San Antonio, Texas on January 17 - 22, 1993

    Science.gov (United States)

    1993-01-22

    two conistantits. It is note Prlha t if Eq.) 3) is igtiored and Iiii is raiidooi ., t hen thet above Crit erioni is i den t ical to Sbl ravev ’s...to calculate the mean square ’ 21 / Vo (EEP) error caused by source coding mses [1]. Furthermore, .19 ( bpp (EEP)- bpp (UEP)) we need the bit-sensitivity

  10. Use of environmental isotope methods as a reconnaissance tool in groundwater exploration near San Antonio de Pichincha, Ecuador

    International Nuclear Information System (INIS)

    Moser, H.; Stichler, W.

    1975-01-01

    In a semiarid area in the Sierra of Ecuador (about 20 km north of Quito), measurements of deuterium, oxygen 18, and tritium content in spring water, surface water, and precipitation have been performed. The results, together with some meteorological and hydrogeological data, furnished information on the recharge area and on the recharge rate of groundwater. On the basis of the results a groundwater exploitation does not appear feasible. (orig.) [de

  11. Technical Proposal on the Treatment of the Influent of the José Antonio Alzate dam Using Aerobic Pond System

    Directory of Open Access Journals (Sweden)

    E. López–Galván

    2010-01-01

    Full Text Available In México, discharge of waste water not treated is a common problem; this is the case of the Lerma River, where the original clean water contribution of the Almoloya–Lerma–San Bartolo timber–roof system, located in the valley of Toluca, State of México, was replaced by the wastewater of the valley. The attempts to clean the water before their spill have been unfruitful and this has caused the present anaerobic conditions of the river in its entire route including the first receiving stage that is the José Antonio Alzate Dam (PJAA, becoming a potential source of diseases and a useless water body. In this work we evaluate the treatment efficiency of experimental waste water pond system. The treatment system was constructed with 5 screens which formed 6 internal channels and it had an operation in continuous form by 26 weeks, providing it with continuously polluted water of the Lerma River. We found that the efficiency of reduction of the organic matter reported as BOD5 was 83% and it is carried out in the first channel after 7 days of hydraulic retention verifying that the channels do not work like lagoons in series. With the collected data we calculated, through the application of design equations, the factor of decay of organic matter "k" and the number of dispersion "d", specific for the type of treatment and environmental conditions of the site. The required surface of treatment calculated to reach the efficiency of reduction of the BOD5 obtained experimentally. Thus, a surface of: 1 281.6 hectares distributed in 13 lagoons that can deal with a volume 8 646, 70 m3/h was determined. Since this was a bigger surfaces than that of the dam, the available area was evaluated to make a proposal closer to reallity.

  12. Antonio Buero Vallejo y Rodolfo Usigli: Historiografía y dramaturgia

    Directory of Open Access Journals (Sweden)

    Guillermo Schmidhuber de la Mora

    2011-11-01

    Full Text Available The article proposes a comparative analysis of the historical plays written by Mexican Rodolfo Usigli and by Spanish Antonio Buero Vallejo in the critical light of Friedrich Nietzsche and Hayden White, so as to explore the validity of Iberoamerican theatre as historiography. It also examines the relationship between history, metaphor, synecdoche and metonymy in their plays

  13. Reflective Mindreading: Theory of Mind and the Search for Self in Antonio Machado's "Soledades"

    Science.gov (United States)

    Mills, Steven

    2011-01-01

    In Antonio Machado's collection "Soledades", the poet's search for identity guides an introspective quest where context, body, and mind form an intricate and inseparable connection. By extending cognitive capabilities to his natural environment, the poet, through embodied cognition and Theory of Mind, reads other people's and nature's minds to…

  14. Antonio Machado y Ruiz (1875-1939) / koost. ja tlk. Andres Ehin

    Index Scriptorium Estoniae

    2006-01-01

    Hispaania luuletajast Antonio Machadost. Sisaldab ka autori luuletusi "Vanasõnad ja laulud XXIX", "Kas mu süda on uinunud?", "Kõrgmaa laulud", "Tuul, toreda päeva tuul", "Eile öösel nägin und", "Neli luuletust"

  15. Antonio Buero Vallejo y Rodolfo Usigli: Historiografía y dramaturgia

    Directory of Open Access Journals (Sweden)

    Guillermo Schmidhuber de la Mora

    2012-11-01

    Full Text Available The article proposes a comparative analysis of the historical plays written by Mexican Rodolfo Usigli and by Spanish Antonio Buero Vallejo in the critical light of Friedrich Nietzsche and Hayden White, so as to explore the validity of Iberoamerican theatre as historiography. It also examines the relationship between history, metaphor, synecdoche and metonymy in their plays

  16. Rimi juht : Citymarket kaob, hinnad alanevad / Antonio Soares ; interv. Toivo Tänavsuu

    Index Scriptorium Estoniae

    Soares, Antonio

    2005-01-01

    Kesko Foodi ja ICA ühisettevõtte Rimi Balticu juht Antonio Soares ei pea võimalikuks Balti turu väiksuse tõttu Citymarketi kaubamärgi jätmist Eestisse. Citymarketid kujundatakse ümber Rimi Hüpermarketiteks

  17. A la memoria de José Antonio Rojas Tercero, 1959-2008

    Directory of Open Access Journals (Sweden)

    José Miguel Fernández Fernández

    2009-06-01

    Full Text Available La revista recuerda la figura de José Antonio Rojas, Catedrático de Economía Financiera y Contabilidad dde la Universidad de Castilla-La Mancha desde el punto de vista humani y profesional

  18. Antonio Maceo: Agent General of the Provisional Revolutionary Government to the Cuban emigration (I

    Directory of Open Access Journals (Sweden)

    José Antonio Navarro Álvarez

    2009-03-01

    Full Text Available This article describes the role of paramount importance played by Antonio Maceo y Grajales as General Agent of the Provisional Government, one of the less studied and known roles of this preeminent patriot of our wars of independence.

  19. Measuring the Sustainability of Tourism in Manuel Antonio and Texel: a Tourist Perspective

    NARCIS (Netherlands)

    Cottrell, S.P.; Duim, van der V.R.; Ankersmid, P.; Kelder, L.

    2004-01-01

    This paper examines tourist perceptions of sustainability in Manuel Antonio/Quepos, Costa Rica and Texel, The Netherlands. It also reviews tourist opinions of site-specific sustainability aspects and assesses differences between tourist types and their perceptions of sustainability. The ecological

  20. Problematizing the "Taken for Granted" in Educational Issues: Karl Marx, Antonio Gramsci, and Michel Foucault.

    Science.gov (United States)

    Qi, Jie

    This paper explores how educators would raise different questions about educational issues by using Karl Marx's framework, Antonio Gramsci's conception, and Michel Foucault's notions, respectively. First, the paper compares the historical perspectives of Marx and Foucault. Marx concludes that history is a progressive linear production and that…

  1. El Área de Contabilidad de la UCLM y José Antonio Rojas

    Directory of Open Access Journals (Sweden)

    Francisco Javier Quesada Sánchez

    2009-06-01

    Full Text Available Breve historia de los cinco primeros cursos del Área de Contabilidad de la Universidad de Castilla-La Mancha con especial referencia a la dedicación y protagonismo del Profesor José Antonio Rojas Tercero, a quien se rinde homenaje.

  2. Marine Ecological Index Survey of San Diego Bay

    Science.gov (United States)

    2013-03-01

    vectors for parasites and disease that can harm both native species and humans (Wilcove et al., 1998; Ruiz et al., 2000). A strain of cholera never...south of Ensenada, Mexico . Here, subtropical waters flow north close to the shore, while subarctic waters flow south offshore. This unique ocean...Canadian Journal of Zoology 78(5):787–793. Mccarthy, S. and K. Khambaty. 1994. “Internation Dissemination of Epidemic Vibrio Cholera by Cargo Ship

  3. Shallow benthic habitats of San Francisco Bay, California CMECS Geodatabase

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has been developed for the National Oceanic and Atmospheric Administration's (NOAA) Office for Coastal Management (OCM) as a collaborative and...

  4. Dengue fever in the San Juan Bay Estuary: Evaluating the ...

    Science.gov (United States)

    Dengue is transmitted by Aedes aegypti, a species that thrives in cities. Here we ask which elements within the urban environment could be managed to reduce the potential for Dengue occurrence. In particular, we study the potential of wetlands in the SJBE to buffer from vector proliferation. Wetlands provide ecosystem services such as heat and water hazard mitigation, water purification and habitat for a diversity of species, all of which are factors that have been shown to affect Dengue vectors. As such, we hypothesize that within coastal neighborhoods in the SJBE wetlands, ecosystem services lead to lower Dengue occurrence. We test this hypothesis using Dengue data from 2010-2013, which includes the largest epidemic in PR history. Our analytical model includes relevant socio-economic factors and environmental controls that may also affect Dengue dynamics. Results indicated a negative effect of neighborhood mangrove cover and a positive effect of percent flood area on Dengue prevalence. Moreover, heat hazards were positively correlated with dengue prevalence and negatively correlated with neighborhood mangrove cover. Dengue prevalence did not correlate with herbaceous wetlands, or with the ecosystem services of water quality or vertebrate species richness. Mosquito borne diseases are an increasingly important health concern, which pose great challenges for safe and sustainable control and eradication. This reality calls for management approaches that consider m

  5. 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

  6. eBay.com

    DEFF Research Database (Denmark)

    Engholm, Ida

    2014-01-01

    Celebrated as one of the leading and most valuable brands in the world, eBay has acquired iconic status on par with century-old brands such as Coca-Cola and Disney. The eBay logo is now synonymous with the world’s leading online auction website, and its design is associated with the company...

  7. 33 CFR 334.870 - San Diego Harbor, Calif.; restricted area.

    Science.gov (United States)

    2010-07-01

    ..., Calif.; restricted area. (a) Restricted area at Bravo Pier, Naval Air Station—(1) The area. The water of... delay or loitering. On occasion, access to the bait barges may be delayed for intermittent periods not... Supply Center Pier—(1) The area. The waters of San Diego Bay extending approximately 100 feet out from...

  8. Professor Antonio Branco Lefèvre: the forefather of child neurology in Brazil Professor Antonio Branco Lefèvre o pai da neurologia infantil no Brasil

    Directory of Open Access Journals (Sweden)

    Rubens Reimão

    2008-09-01

    Full Text Available OBJECTIVE: To report on the life and works of Prof. Antonio Branco Lefèvre and the relevance that led him to be considered the Forefather of Child Neurology in Brazil. METHOD: The method utilized was the historical documents research; bibliographical. RESULTS: Antonio Branco Lefèvre (1916-1981 was born in São Paulo city; graduated in 1941 from the São Paulo Medical School. The date - 1950 - can be considered when Child Neurology took shape for a fully specialty, when Lefèvre presented his two internationally acclaimed thesis. Lefèvre was recognized as he founder of Child Neurology in Brazil since the early years of his brilliant academic activities. In 1967 achieved the title of professor in the Child Neurology Clinic. His numerous trainees and Residents - from -1950 to 1981 - held today key positions in Brazilian Child Neurology. CONCLUSION: The extension and importance of the Child Neurology School of which he is the legitimate founder is recognized.OBJETIVO: Relatar a vida e obra do Prof. Antonio Branco Lefèvre e a relevância que leva a ser denominado o Pai da Neurologia Infantil no Brasil. MÉTODO: Pesquisa de documentos históricos e bibliográfica. RESULTADOS: Antonio Branco Lefèvre (1916-1981 nascido em São Paulo; formou-se na Faculdade de Medicina de São Paulo em 1941. A data de 1950 pode ser considerada quando a Neurologia Infantil tornou-se uma especialidade completa quando Lefèvre defendeu suas duas teses aclamadas internacionalmente. Lefévre foi reconhecido como o Pai da Neurologia Infantil no Brasil desde os primeiros anos de sua carreira acadêmica brilhante. Em 1967 atingiu o título de Professor de Neurologia Clínica Infantil. Seus numerosos estagiários e Residentes - de 1950 a 1981 - têm hoje posições de destaque na Neurologia Infantil brasileira. CONCLUSÃO: É reconhecida a extensão e a relevância da escola de Neurologia Infantil da qual Lefèvre é o legítimo fundador.

  9. Pictures to a story. Notes on Vita di San Filippo Neri at the Civic Museum of Bassano del Grappa

    Directory of Open Access Journals (Sweden)

    Federica Vettori

    2014-12-01

    Full Text Available During the eighteenth century the venetian publishing knows a flowering season thanks to the involvement of great artists in the field of illustration. Pietro Antonio Novelli was one of the most prolific inventors of decorations for illustrated books. He sketched the illustrations of Vita di San Filippo Neri engraved by Innocente Alessandri and printed in Venice in 1793. At the Museum of Bassano del Grappa we can find a special watercolored edition: sixty large prints that tell, as if they were history paintings, the life of the saint.

  10. SANS studies of polymers

    International Nuclear Information System (INIS)

    Wignall, G.D.

    1984-10-01

    Before small-angle neutron scattering (SANS), chain conformation studies were limited to light and small angle x-ray scattering techniques, usually in dilute solution. SANS from blends of normal and labeled molecules could give direct information on chain conformation in bulk polymers. Water-soluble polymers may be examined in H 2 O/D 2 O mixtures using contrast variation methods to provide further information on polymer structure. This paper reviews some of the information provided by this technique using examples of experiments performed at the National Center for Small-Angle Scattering Research (NCSASR)

  11. Wastewater characterization of the community 'Antonio Maceo' of the Oriente University

    International Nuclear Information System (INIS)

    Crombet Grillet, Sandra; Perez Pompa, Norma; Abalos Rodriguez, Arelis; Rodriguez Perez, Suyen

    2013-01-01

    The main environmental problems of the Universidad de Oriente are associated with the emission of uncontrolled and untreated solid and liquid waste to the environment. In the university community 'Antonio Maceo' 1 360 people now living, of which 70 % are students of the institution. This community poured about 23 462,7 L/d of wastewater residual liquids composed of 15 buildings and the waters of the kitchen and cafeteria. In this paper we evaluate the physico-chemical and microbiological wastewater university community Antonio Maceo, determining environmental parameters of highest incidence. The waters are neutral and proper salinity. They have gray color, odor and cloudy appearance, without the presence of floating material. The organic matter content is above discharge limits and detected total and fecal coli forms. The greatest variability (46,5 %) of wastewater depends on the turbidity, COD, BOD 5 , sulfide, ammonium, oil and grease and total solids and fixe

  12. Los realismos en Beatus Ille de Antonio Muñoz Molina.

    Directory of Open Access Journals (Sweden)

    Papa Mamour Diop

    2007-07-01

    Full Text Available ENGLISH: This work deals with the current debate about reality and its literary and artistic expression: realism. In Beatus Ille, Antonio Muñoz Molina’s first novel, the fictional universe reveals three kinds of realism: the epic and elegiac realism, the historic realismand the magic realism. SPANISH: En este trabajo, abordamos el actual debate sobre la realidad y su expresión literaria y artística: el realismo. En Beatus Ille, primera novela de Antonio Muñoz Molina, eluniverso novelesco permite percibir tres tipos de realismos: el realismo épico elegiaco, el realismo histórico o contrafactual y el realismo mágico.

  13. 77 FR 54815 - Safety Zone: America's Cup World Series Regattas, San Francisco Bay; San Francisco, CA

    Science.gov (United States)

    2012-09-06

    ... believe a public meeting would be beneficial. If we determine that one would aid this rulemaking, we will... Fisherman's Wharf Breakwater, running east to position 37[deg]48'43'' N, 122[deg]25'01'' W, running north to position 37[deg]49'07'' N, 122[deg]25'01'' W, running northwest to position 37[deg]49'14'' N, 122[deg]25'12...

  14. 78 FR 10062 - Safety Zone; Sea World San Diego Fireworks, Mission Bay; San Diego, CA

    Science.gov (United States)

    2013-02-13

    ... opportunity to comment pursuant to authority under section 4(a) of the Administrative Procedure Act (APA) (5 U... Directive 023-01 and Commandant Instruction M16475.lD, which guide the Coast Guard in complying with the...

  15. 78 FR 77597 - Safety Zone; Allied PRA-Solid Works, San Diego Bay; San Diego, CA

    Science.gov (United States)

    2013-12-24

    ... authority under section 4(a) of the Administrative Procedure Act (APA) (5 U.S.C. 553(b)). This provision... M16475.lD, which guide the Coast Guard in complying with the National Environmental Policy Act of 1969...

  16. Networked but No System: Educational Innovation among Bay Area Jewish Organizations

    Science.gov (United States)

    Rubin Ross, Renee

    2017-01-01

    A widely read article from this journal explores innovative Jewish educational programs, initiatives, and organizations, arguing that these share a comdmitment to being "learner-centered" and recommending that a system be created to foster collaboration among them (Woocher, 2012). Using five San Francisco Bay Area-based…

  17. is-à-vis : Antonio Tabucchi et Fernando Pessoa. Étude de la médiation culturelle dans les fictions biographiques d’Antonio Tabucchi

    Directory of Open Access Journals (Sweden)

    Audrey Lemieux

    2010-12-01

    Full Text Available Comment un écrivain écrit-il à propos d’un autre écrivain – non seulement l’histoire d’une vie, mais la singularité, la vérité particulière d’un homme ? Cet article examine les différentes stratégies par lesquelles l’écrivain-biographe Antonio Tabucchi, dans ses fictions biographiques, parvient à mettre en scène le personnage de Fernando Pessoa, malgré la distance qui les sépare – distance qui semble reposer, à première vue, sur des enjeux culturels, mais qui se révèle être essentiellement ontologique. How does one author undertake writing about another–not only in terms of recounting the story of a life, but also the singularity, the inner truth of a human being? This paper will explore the different strategies by means of which the author/biographer Antonio Tabucchi manages to portray the character of Fernando Pessoa in his biographical fictions, in spite of the distance between them–a distance that initially appears to be rooted in cultural issues, but later reveals itself to be of an essentially ontological order.

  18. Spinoza «protobiologo». Emozioni e sentimenti secondo Antonio Damasio

    Directory of Open Access Journals (Sweden)

    Mariagrazia Portera

    2012-05-01

    Full Text Available My essay reconstructs the broad outline of Antonio Damasio's thought, with particoular reference to his book Looking for Spinoza: Joy, Sorrow and the Feeling Brain (2003, where Damasio describes from a neurobiological point of view human feelings and emotions. In doing that, he highlights how most of the main outcomes of contemporary neurobiological research confirms Spinoza's conception about feelings and emotions (Ethica, 1677.

  19. A reading of Antonio Tabucchi's Il filo dell'orizzonte | Wilson | Italian ...

    African Journals Online (AJOL)

    Questa lettura de Il filo dell'orizzonte (1986) di Antonio Tabucchi esamina il percorso del protagonista, Spino, attraverso gli spazi di una città. La sua è una ricerca ossessiva delle “segrete ragioni” che guidano una vita. Nel tentativo di restituire l'esistenza ad un morto, Spino percepisce che la reciprocità del legame fra vita e ...

  20. Biblioteca gramsciana: os livros da prisão de Antonio Gramsci

    Directory of Open Access Journals (Sweden)

    Lincoln Secco

    2004-06-01

    Full Text Available This article presents preliminary conclusions from research on the books read by Antonio Gramsci in the prison library. Although he had only a few books by Marxist authors at his disposal, Gramsci still was able to face the most important issues of his time. In addition, the article argues that in his Prison Notebooks, Gramsci analyzed these books and their publishers as a means of showing the link between culture and the public.