Anthropometric Sizing, Fit-Testing and Evaluation of the MBU-12/P Oral-Nasal Oxygen Mask

DTIC Science & Technology

1979-08-01

Engineering Company, Sierra Madre , California, has a low profile single-unit facepiece in which a deformable silicone rubber face form is bonded to a...Churchill & Truett, 1957; Hertzberg et al., 1954). This comparison indicated that the 1967 sample was, on the average, older (2.64 years), taller (1.78...Support Special Projects Office, Wright-Patterson Air Force Base, Ohio, which, in turn, contracted with Sierra Engineering Company, Sierra Madre , California

Cretaceous plutonic rocks in the Donner Lake-Cisco Grove area, northern Sierra Nevada, California

USGS Publications Warehouse

Kulow, Matthew J.; Hanson, Richard E.; Girty, Gary H.; Girty, Melissa S.; Harwood, David S.

1998-01-01

The northernmost occurrences of extensive, glaciated exposures of the Sierra Nevada batholith occur in the Donner Lake-Cisco Grove area of the northern Sierra Nevada. The plutonic rocks in this area, which are termed here the Castle Valley plutonic assemblage, crop out over an area of 225 km2 and for the most part are shown as a single undifferentiated mass on previously published geological maps. In the present work, the plutonic assemblage is divided into eight separate intrusive units or lithodemes, two of which each consist of two separate plutons. Compositions are dominantly granodiorite and tonalite, but diorite and granite form small plutons in places. Spectacular examples of comb layering and orbicular texture occur in the diorites. U-Pb zircon ages have been obtained for all but one of the main units and range from ~120 to 114 Ma, indicating that the entire assemblage was emplaced in a narrow time frame in the Early Cretaceous. This is consistent with abundant field evidence that many of the individual phases were intruded penecontemporaneously. The timing of emplacement correlates with onset of major Cretaceous plutonism in the main part of the Sierra Nevada batholith farther south. The emplacement ages also are similar to isotopic ages for gold-quartz mineralization in the Sierran foothills west of the study area, suggesting a direct genetic relationship between the voluminous Early Cretaceous plutonism and hydrothermal gold mineralization.

Risk in the "Red Zone": Outcomes for Children Admitted to Ebola Holding Units in Sierra Leone Without Ebola Virus Disease.

PubMed

Fitzgerald, F; Wing, K; Naveed, A; Gbessay, M; Ross, J C G; Checchi, F; Youkee, D; Jalloh, M B; Baion, D; Mustapha, A; Jah, H; Lako, S; Oza, S; Boufkhed, S; Feury, R; Bielicki, J; Williamson, E; Gibb, D M; Klein, N; Sahr, F; Yeung, S

2017-07-01

We collected data on 1054 children admitted to Ebola Holding Units in Sierra Leone and describe outcomes of 697/1054 children testing negative for Ebola virus disease (EVD) and accompanying caregivers. Case-fatality was 9%; 3/630 (0.5%) children discharged testing negative were readmitted EVD-positive. Nosocomial EVD transmission risk may be lower than feared. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Ecology, biodiversity, management, and restoration of aspen in the Sierra Nevada

Treesearch

Wayne D. Shepperd; Paul C. Rogers; David Burton; Dale L. Bartos

2006-01-01

This report was commissioned by the USDA Forest Service Lake Tahoe Basin Management Unit to synthesize existing information on the ecology and management of aspen (Populus tremuloides) in the Sierra Nevada of California and surrounding environs. It summarizes available information on aspen throughout North America from published literature, internal...

77 FR 74688 - Final Recovery Plan, First Revision; Mexican Spotted Owl

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-17

... Arizona, Colorado, New Mexico, Texas, and Utah, and south through the Sierra Madre Occidental and Sierra Madre Oriental in Mexico. The recovery plan includes specific recovery objectives and criteria to be met...). The revised recovery plan was prepared by a team of experts from both the United States and Mexico...

Youth Reintegration Training and Education for Peace (YRTEP) Program: Sierra Leone, 2000-2001. Impact Evaluation.

ERIC Educational Resources Information Center

Fauth, Gloria; Daniels, Bonnie

Management Systems International (MSI), with funding from United States Agency for International Development Office of Transition Initiatives (USAID/OTI) and in coordination with other partners, is implementing a program in Sierra Leone entitled "Youth Reintegration Training and Education for Peace" (YRTEP). The object is to provide…

[Nutrition iodine status in pregnant women in the sanitary district Sierra de Huelva-Andévalo, South of Spain].

PubMed

Arrobas-Velilla, Teresa; González-Rodríguez, Concepción; Barco-Sánchez, Antonio; Castaño-López, Miguel; Perea-Carrasco, Rafael; Pascual-Salvador, Elena; Limón-Padilla, J; Marina-Tascón, Elena; Perea-Brenes, M; Sánchez-Mateos, María Aguila; González-Martin, Carmen; Bermúdez-de-la-Vega, José Antonio; Albusac-Aguilar, Rogelio; Fabiani-Romero, Fernando

2011-01-01

Iodine is an essential trace element implicated in synthesis of thyroid hormones. Iodine requirements vary throughout life. This iodine requirement is increased during pregnancy and breastfeeding. In a previous study carried out by our group in 2008, we detected an iodine-deficient area in the province of Huelva, specially in district Sierra de Huelva-Andévalo by means of neonatal TSH determinations. To reinforce the iodine supplementation campaign and its impact on their newborns in order to assess nutrition iodine status in pregnant women using questionnaire and ioduria determination. This study has been jointly carried out by Congenital Hypothyroidism Unit of the Clinical Biochemistry Department of the Virgen Macarena University Hospital (Seville) and the Gynecology and Clinical Analysis Unit of the Río Tinto Hospital (Huelva) during two years. We studied 313 pregnant women. All of them filled out a personal questionnaire to know the iodine nutritional status in their area. Ioduria was determinated by high-resolution liquid chromatography. Data from pregnant women and results of the studied variables were analyzed with SPSS v13.0. Pregnant women from the sanitary district Sierra de Huelva-Andévalo present a median for ioduria which corresponds to an insufficient iodine intake according to the WHO classification. The questionnaires suggest that this iodine deficiency is consequence of an insufficient iodine intake and a low adherence to the treatment.

Population dynamics of the California spotted owl in the Sierra Nevada, California

Treesearch

J.A. Blakesley; M.E. Seamans; M.M. Connor; A.B. Franklin; G.C. White; R.J. Gutierrez; J.E. Hines; J.D. Nichols; T.E. Munton; D.W.H. Shaw; J.J. Keane; G.N. Steger; T.L. McDonald

2010-01-01

The California spotted owl (Strix occidentalis occidentalis) is the only spotted owl subspecies not listed as threatened or endangered under the United States Endangered Species Act despite petitions to list it as threatened. We conducted a meta-analysis of population data for 4 populations in the southern Cascades and Sierra Nevada, California,...

Stratigraphy and depositional environment of unnamed (lower Miocene) submarine-fan sandstone unit in Sierra Madre and San Rafael Mountains, northeastern Santa Barbara County, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, G.D.; Fritsche, A.E.; Condon, M.W.

1988-03-01

A relatively thick and extensive, previously unnamed, lower Miocene sandstone unit occurs in the central Sierra Madre and in the Hurricane Deck area of the San Rafael Mountains of northeastern Santa Barbara County, California. It is underlain conformably and interfingers with a dark mudstone that correlates with the Soda Lake Shale Member of the Vaqueros Formation; it is overlain conformably and interfingers with a brown shale that correlates with the Saltos Member of the Monterey Shale. Northeastern exposures along the north flank of the Sierra Madre are almost exclusively medium to coarse-grained, structureless sandstone with scattered pebbly conglomerate beds. Thicknessmore » ranges from zero in the southeastern part of the Sierra Madre to 70 m in the northeast, 75 m in the northwest, and 600 m in the central part of the range. Toward the southwest in the Hurricane Deck area of the San Rafael Mountains, the unit becomes thicker and more extensively interbedded with mudstone. Lithology of the unit consists of 0.3-3.5 m thick beds of medium to coarse-grained, structureless to vaguely graded sandstone with scoured contacts at the base. Sandstone beds 0.3-3.0 m thick, which are more distinctly graded from coarse to very fine are also present. The interbedded mudstone commonly is bioturbated, so bedding is indistinct. Thickness ranges from 1020 m in the central part of the area to 750 m toward the southwest and 92 m toward the northwest. The unit most likely represents deposition in a submarine-canyon and fan complex that had its channel head in the northeast and spread southwestward into a thick sequence of submarine-fan sandstone lobes, which were confined in a narrow west-trending trough.« less

KSC-2011-8116

NASA Image and Video Library

2011-12-01

CAPE CANAVERAL, Fla. -- This is an artist's conception of the Dream Chaser spacecraft under development by Sierra Nevada of Centennial, Colo., for NASA's Commercial Crew Program (CCP). In 2011, NASA selected Sierra Nevada during Commercial Crew Development Round 2 (CCDev2) activities to mature the design and development of a crew transportation system with the overall goal of accelerating a United States-led capability to the International Space Station. The goal of CCP is to drive down the cost of space travel as well as open up space to more people than ever before by balancing industry’s own innovative capabilities with NASA's 50 years of human spaceflight experience. Six other aerospace companies also are maturing launch vehicle and spacecraft designs under CCDev2, including Alliant Techsystems Inc. (ATK), The Boeing Co., Excalibur Almaz Inc., Blue Origin, Space Exploration Technologies (SpaceX), and United Launch Alliance (ULA). For more information, visit www.nasa.gov/commercialcrew. Image credit: Sierra Nevada Corp.

GPS Imaging suggests links between climate, magmatism, seismicity, and tectonics in the Sierra Nevada-Long Valley Caldera-Walker Lane system, western United States

NASA Astrophysics Data System (ADS)

Hammond, W. C.; Blewitt, G.; Kreemer, C.; Smith, K.

2017-12-01

The Walker Lane is a region of complex active crustal transtension in the western Great Basin of the western United States, accommodating about 20% of the 50 mm/yr relative motion between the Pacific and North American plates. The Long Valley caldera lies in the central Walker Lane in eastern California, adjacent to the eastern boundary of the Sierra Nevada/Great Valley microplate, and experiences intermittent inflation, uplift, and volcanic unrest from the magma chamber that resides at middle crustal depths. Normal and transform faults accommodating regional tectonic transtension pass by and through the caldera, complicating the interpretation of the GPS-measured strain rate field, estimates of fault slip rates, and seismic hazard. Several dozen continuously recording GPS stations measure strain and uplift in the area with mm precision. They observe that the most recent episode of uplift at Long Valley began in mid-2011, continuing until late 2016, raising the surface by 100 mm in 6 years. The timing of the initiation of uplift coincides with the beginning of severe drought in California. Furthermore, the timing of a recent pause in uplift coincides with the very wet 2016-2017 winter, which saw approximately double normal snow pack. In prior studies, we showed that the timing of changes in geodetically measured uplift rate of the Sierra Nevada coincides with the timing of drought conditions in California, suggesting a link between hydrological loading and Sierra Nevada elevation. Here we take the analysis three steps further to show that changes in Sierra Nevada uplift rate coincide in time with 1) enhanced inflation at the Long Valley caldera, 2) shifts in the patterns and rates of horizontal tensor strain rate, and 3) seismicity patterns in the central Walker Lane. We use GPS solutions from the Nevada Geodetic Laboratory and the new GPS Imaging technique to produce robust animations of the time variable strain and uplift fields. The goals of this work are to document links between climate, Sierra Nevada uplift rates, response of the magmatic system, and seismicity in the Central Walker Lane, and to explore the physical mechanisms that may be behind these correlations.

Quantifying the risk of nosocomial infection within Ebola Holding Units: a retrospective cohort study of negative patients discharged from five Ebola Holding Units in Western Area, Sierra Leone.

PubMed

Arkell, Paul; Youkee, Daniel; Brown, Colin S; Kamara, Abdul; Kamara, Thaim B; Johnson, Oliver; Lado, Marta; George, Viginia; Koroma, Fatmata; King, Matilda B; Parker, Benson E; Baker, Peter

2017-01-01

A central pillar in the response to the 2014 Ebola virus disease (EVD) epidemic in Sierra Leone was the role of Ebola Holding Units (EHUs). These units isolated patients meeting a suspect case definition, tested them for EVD, initiated appropriate early treatment and discharged negative patients to onward inpatient care or home. Positive patients were referred to Ebola Treatment Centres. We aimed to estimate the risk of nosocomial transmission within these EHUs. We followed up a cohort of 543 patients discharged with a negative EVD test from five EHUs in the Western Area, Sierra Leone, and examined all line-listed subsequent EVD tests from any facility in the Western Area to see whether the patient was retested within 30 days, matching by name, age and address. We defined possible readmissions as having the same name and age but uncertain address, and confirmed readmissions where name, age and address matched. We found a positive readmission rate of 3.3% (18 cases), which included 1.5% confirmed readmissions (8 cases) and 1.8% possible readmissions (10 cases). This is lower than rates previously reported. We cannot ascertain whether EVD was acquired within the EHUs or from re-exposure in the community. No demographic or clinical variables were identified as risk factors for positive readmission, likely due to our small sample size. These findings support the EHU model as a safe method for isolation of suspect EVD patients and their role in limiting the spread of EVD. © 2016 John Wiley & Sons Ltd.

Patterns and average rates of late Neogene Recent uplift of the Betic Cordillera, SE Spain

NASA Astrophysics Data System (ADS)

Braga, Juan C.; Martín, José M.; Quesada, Cecilio

2003-02-01

The facies distribution in the sedimentary units infilling a series of Neogene basins has been used to reconstruct the relief generation and uplift across the Internal Zone of the Betic Cordillera in southern Spain. Uplift amounts and average rates can be estimated using the current elevation of the outcrops of well-dated deposits indicative of ancient sea-level positions. Coral reefs and coastal conglomerates record the initial development of emergent Betic relief during the Langhian. Continental and marginal marine deposits indicate the existence of a large island centred on the present Sierra Nevada-Sierra de los Filabres chain by the end of the Middle Miocene. The precursor of the Sierra Nevada-Sierra de los Filabres chain, originally part of this large island, remained emerged whilst the surrounding areas were re-invaded by the sea during the early Tortonian. At the end of the Tortonian the inland basins (Granada and Guadix basins) became continental, while the Sierras de la Contraviesa, Sierra de Gádor and Sierra Alhamilla emerged, separating the Alborán Basin from the Alpujarra, Tabernas and Sorbas basins, which became narrow passages of the Mediterranean Sea. In contrast, the Sierra Cabrera emerged during the late Messinian, suggesting a progressive uplift from west to east of the sierras south of the Sierra Nevada-Sierra de los Filabres chain. During the Pliocene, only the low areas closest to the present-day coast remained as marine basins and progressively emerged throughout this stage. The highest average uplift rate recorded is 280 m/Ma for the Sierra de Gádor, although the average uplift rates of upper-Neogene coastal marine rocks since depositon have maximum values of approximately 200 m/Ma. Most of the uplift of the Betic mountains took place before the early Pliocene. The recorded uplift of Neogene rocks was highest at the margins of western Sierra Nevada, where peaks higher than 3000 m occur. The average rates of uplift were lower to the east of this major relief. The main sierras and depressions in the present-day landscape correspond respectively to the emergent land, in which uplift was concentrated, and to the marine basins that existed before the final emergence of the region. The altitude of the sierras reflects the time at which they became emergent, the highest mountains being the first to rise above sea level.

Satellite Image Mapping of Tree Mortality in the Sierra Nevada Region of California from 2013 to 2016

NASA Technical Reports Server (NTRS)

Potter, Christopher S.

2017-01-01

Extreme drought from 2013 to 2015 has been linked to extensive tree dieback in the Sierra-Nevada region of California. Landsat satellite imagery was analysed for the region from Lake Tahoe to the southern Sequoia National Forest with the objective of understanding the patterns of tree mortality in the years of 2013 to 2015 and into the near-normal precipitation year of 2016. The main mapping results for Landsat moisture index differences from year-to-year showed that the highest coverage of tree dieback was located in the Sierra and Sequoia National Forests, at four to five times greater area each year than within any other National Park or National Forest unit. Since 2013, over 50% of the Sierra Nevada forest dieback area was detected in the mid elevation zone of 1000-2000 m. The total area of tree mortality in the lower elevation zone of 500-1000 m did not grow notably from 2015 to 2016. Within the largest California river drainages in the Sierra region, new tree mortality in 2015 was detected mainly below 1200 m elevation, whereas new tree mortality in 2016 was detected mainly at higher elevations, up to about 2200 m. In three out of the four years studied, results showed that about 60% of all new tree mortality areas were located on north-facing hill slopes.

GPS Imaging of vertical land motion in California and Nevada: Implications for Sierra Nevada uplift

NASA Astrophysics Data System (ADS)

Hammond, William C.; Blewitt, Geoffrey; Kreemer, Corné

2016-10-01

We introduce Global Positioning System (GPS) Imaging, a new technique for robust estimation of the vertical velocity field of the Earth's surface, and apply it to the Sierra Nevada Mountain range in the western United States. Starting with vertical position time series from Global Positioning System (GPS) stations, we first estimate vertical velocities using the MIDAS robust trend estimator, which is insensitive to undocumented steps, outliers, seasonality, and heteroscedasticity. Using the Delaunay triangulation of station locations, we then apply a weighted median spatial filter to remove velocity outliers and enhance signals common to multiple stations. Finally, we interpolate the data using weighted median estimation on a grid. The resulting velocity field is temporally and spatially robust and edges in the field remain sharp. Results from data spanning 5-20 years show that the Sierra Nevada is the most rapid and extensive uplift feature in the western United States, rising up to 2 mm/yr along most of the range. The uplift is juxtaposed against domains of subsidence attributable to groundwater withdrawal in California's Central Valley. The uplift boundary is consistently stationary, although uplift is faster over the 2011-2016 period of drought. Uplift patterns are consistent with groundwater extraction and concomitant elastic bedrock uplift, plus slower background tectonic uplift. A discontinuity in the velocity field across the southeastern edge of the Sierra Nevada reveals a contrast in lithospheric strength, suggesting a relationship between late Cenozoic uplift of the southern Sierra Nevada and evolution of the southern Walker Lane.

Reproduction, abundance, and population growth for a fisher (Pekania pennanti) population in the Sierra National Forest, California

Treesearch

Rick A. Sweitzer; Viorel D. Popescu; Reginald H. Barrett; Kathryn L. Purcell; Craig M. Thompson

2015-01-01

In the west coast region of the United States, fishers (Pekania pennanti) exist in 2 remnant populations—1 in northern California and 1 in the southern Sierra Nevada, California—and 3 reintroduced populations (western Washington, southern Oregon, and northeastern California). The West Coast Distinct Population Segment of fishers encompassing all of...

New constraints on the origin of the Sierra Madre de Chiapas (south Mexico) from sediment provenance and apatite thermochronometry

NASA Astrophysics Data System (ADS)

Witt, C.; Brichau, S.; Carter, A.

2012-12-01

The timing and source of deformation responsible for formation of the Sierra Madre de Chiapas (south Mexico) are unclear. To address this, apatite fission track and U-Th-He thermochronometry, combined with zircon U-Pb dating, were performed on bedrock and sedimentary samples of the Sierra Madre de Chiapas to discern timing of exhumation and identify sediment source areas. The U-Pb results show that Paleocene-Eocene terrigenous units outcropping at the northern section of the Sierra were mostly derived from Grenville (˜1 Ga) basement whereas the internal sections of the chain yield mainly Permian to Triassic ages (circa 270-230 Ma) typical of the Chiapas massif complex. Grenville-sourced sediments are most probably sourced by the Oaxacan block or the Guichicovi complex and were deposited to the north of the Sierra in a foreland setting related to a Laramide deformation front. Other possibly source areas may be related to metasedimentary units widely documented at the south Maya block such as the Baldi unit. The apatite fission track and U-Th-He data combined with previously published results record three main stages in exhumation history: (1) slow exhumation between 35 and 25 Ma affecting mainly the Chiapas massif complex; (2) fast exhumation between 16 and 9 Ma related to the onset of major strike-slip deformation affecting both the Chiapas massif complex and Chiapas fold-and-thrust belt; and (3) a 6 to 5 Ma period of rapid cooling that affected the Chiapas fold-and-thrust belt, coincident with the landward migration of the Caribbean-North America plate boundaries. These data suggest that most of the topographic growth of the Sierra Madre de Chiapas took place in the middle to late Miocene. The new thermochronological evidence combined with stratigraphic and kinematic information suggests that the left-lateral strike-slip faults bounding the Chiapas fold-and-thrust belt to the west may have accommodated most of the displacement between the North American and Caribbean plates during the last 6-5 Ma.

Ebola Virus Disease in Children, Sierra Leone, 2014–2015

PubMed Central

Naveed, Asad; Wing, Kevin; Gbessay, Musa; Ross, J.C.G.; Checchi, Francesco; Youkee, Daniel; Jalloh, Mohammed Boie; Baion, David; Mustapha, Ayeshatu; Jah, Hawanatu; Lako, Sandra; Oza, Shefali; Boufkhed, Sabah; Feury, Reynold; Bielicki, Julia A.; Gibb, Diana M.; Klein, Nigel; Sahr, Foday; Yeung, Shunmay

2016-01-01

Little is known about potentially modifiable factors in Ebola virus disease in children. We undertook a retrospective cohort study of children <13 years old admitted to 11 Ebola holding units in the Western Area, Sierra Leone, during 2014–2015 to identify factors affecting outcome. Primary outcome was death or discharge after transfer to Ebola treatment centers. All 309 Ebola virus–positive children 2 days–12 years old were included; outcomes were available for 282 (91%). Case-fatality was 57%, and 55% of deaths occurred in Ebola holding units. Blood test results showed hypoglycemia and hepatic/renal dysfunction. Death occurred swiftly (median 3 days after admission) and was associated with younger age and diarrhea. Despite triangulation of information from multiple sources, data availability was limited, and we identified no modifiable factors substantially affecting death. In future Ebola virus disease epidemics, robust, rapid data collection is vital to determine effectiveness of interventions for children. PMID:27649367

KSC-2012-1015

NASA Image and Video Library

2012-01-12

CAPE CANAVERAL, Fla. -- This is an artist's conception of the Dream Chaser spacecraft integrated with an Atlas V rocket. Dream Chaser is under development by Sierra Nevada of Centennial, Colo., for NASA's Commercial Crew Program (CCP). In 2011, NASA selected Sierra Nevada during Commercial Crew Development Round 2 (CCDev2) activities to mature the design and development of a crew transportation system with the overall goal of accelerating a United States-led capability to the International Space Station. United Launch Alliance's Atlas V also is being considered under CCDev2. The goal of CCP is to drive down the cost of space travel as well as open up space to more people than ever before by balancing industry’s own innovative capabilities with NASA's 50 years of human spaceflight experience. Five other aerospace companies also are maturing launch vehicle and spacecraft designs under CCDev2, including Alliant Techsystems Inc. (ATK), The Boeing Co., Excalibur Almaz Inc., Blue Origin, and Space Exploration Technologies (SpaceX). For more information, visit www.nasa.gov/commercialcrew. Image credit: Sierra Nevada Corp.

GPS Imaging of vertical land motion in California and Nevada: Implications for Sierra Nevada uplift

PubMed Central

Blewitt, Geoffrey; Kreemer, Corné

2016-01-01

Abstract We introduce Global Positioning System (GPS) Imaging, a new technique for robust estimation of the vertical velocity field of the Earth's surface, and apply it to the Sierra Nevada Mountain range in the western United States. Starting with vertical position time series from Global Positioning System (GPS) stations, we first estimate vertical velocities using the MIDAS robust trend estimator, which is insensitive to undocumented steps, outliers, seasonality, and heteroscedasticity. Using the Delaunay triangulation of station locations, we then apply a weighted median spatial filter to remove velocity outliers and enhance signals common to multiple stations. Finally, we interpolate the data using weighted median estimation on a grid. The resulting velocity field is temporally and spatially robust and edges in the field remain sharp. Results from data spanning 5–20 years show that the Sierra Nevada is the most rapid and extensive uplift feature in the western United States, rising up to 2 mm/yr along most of the range. The uplift is juxtaposed against domains of subsidence attributable to groundwater withdrawal in California's Central Valley. The uplift boundary is consistently stationary, although uplift is faster over the 2011–2016 period of drought. Uplift patterns are consistent with groundwater extraction and concomitant elastic bedrock uplift, plus slower background tectonic uplift. A discontinuity in the velocity field across the southeastern edge of the Sierra Nevada reveals a contrast in lithospheric strength, suggesting a relationship between late Cenozoic uplift of the southern Sierra Nevada and evolution of the southern Walker Lane. PMID:27917328

GPS Imaging of vertical land motion in California and Nevada: Implications for Sierra Nevada uplift.

PubMed

Hammond, William C; Blewitt, Geoffrey; Kreemer, Corné

2016-10-01

We introduce Global Positioning System (GPS) Imaging, a new technique for robust estimation of the vertical velocity field of the Earth's surface, and apply it to the Sierra Nevada Mountain range in the western United States. Starting with vertical position time series from Global Positioning System (GPS) stations, we first estimate vertical velocities using the MIDAS robust trend estimator, which is insensitive to undocumented steps, outliers, seasonality, and heteroscedasticity. Using the Delaunay triangulation of station locations, we then apply a weighted median spatial filter to remove velocity outliers and enhance signals common to multiple stations. Finally, we interpolate the data using weighted median estimation on a grid. The resulting velocity field is temporally and spatially robust and edges in the field remain sharp. Results from data spanning 5-20 years show that the Sierra Nevada is the most rapid and extensive uplift feature in the western United States, rising up to 2 mm/yr along most of the range. The uplift is juxtaposed against domains of subsidence attributable to groundwater withdrawal in California's Central Valley. The uplift boundary is consistently stationary, although uplift is faster over the 2011-2016 period of drought. Uplift patterns are consistent with groundwater extraction and concomitant elastic bedrock uplift, plus slower background tectonic uplift. A discontinuity in the velocity field across the southeastern edge of the Sierra Nevada reveals a contrast in lithospheric strength, suggesting a relationship between late Cenozoic uplift of the southern Sierra Nevada and evolution of the southern Walker Lane.

Late Paleozoic transpression in Buenos Aires and northeast Patagonia ranges, Argentina

NASA Astrophysics Data System (ADS)

Rossello, E. A.; Massabie, A. C.; López-Gamundí, O. R.; Cobbold, P. R.; Gapais, D.

1997-12-01

Paleozoic sediments are present in three regions in eastern central Argentina: (1) the Sierras Australes of Buenos Aires, (2) Sierras Septentrionales of Buenos Aires and (3) Northeast Patagonia. All of these deposits share a common deformational imprint imparted by late Paleozoic Gondwanan deformation. Exposures of these rocks are scattered, variably deformed, and isolated by younger sediments deposited in basins related to the Mesozoic through Tertiary opening of the South Atlantic such as the offshore Colorado Basin. The Sierras Australes of Buenos Aires outcrops are the best preserved. They are mostly located along the Sierras Australes foldbelt, with minor outliers distributed in the adjacent Claromec-basin. The Tunas Formation (early-early late? Permian) is the uppermost unit of the Pillahuincó Group (late Carboniferous-Permian) and is crucial to the understanding of the tectono-sedimentary evolution of the region during the late Paleozoic. The underlying units of the Pillahuincó Group (Sauce Grande, Piedra Azul and Bonete Formations) exhibit a depositional and compositional history characterized by glaciomarine sedimentation and postglacial transgression. They are also characterized by rather uniform quartz-rich compositions indicative of a cratonic provenance from the La Plata craton to the NE. In contrast, the sandstone-rich Tunas Formation has low quartz contents, and abundant volcanic and metasedimentary fragments; paleocurrents are consistently from the SW. Glassrich tuffs are interbedded with sandstone in the upper half of the Tunas Formation. The age of the deformation in the Sierras Australes is Permian and early-middle Triassic. This is based on metamorphic events indicated by formation of illite at 282 ± 3 Ma, 273 ± 8 Ma, 265 ± 3 Ma, and 260 ± 3 Ma ( {K}/{Ar} illite) in the Silurian Curamalal Group. Evidence of syntectonic magmatism is provided by a radiometric date of 245 ± 12 Ma ( {K}/{Ar} hornblende) for the López Lecube Granite, immediately west of the Sierras Australes. In the Sierras Septentrionales of Buenos Aires, Precambrian through early Paleozoic deposits of La Tinta, Sierras Bayas, Las Aguilas and Balcarce Formations rest on Precambrian crystalline basement of the La Plata craton. These exposed rocks are affected by subordinate, right lateral wrench faulting; some thrusting indicates tectonic transport toward the NE. In northeast Patagonia (Sierra Grande region) synkinematic deformation of early Permian (261 ± 5 Ma, {Rb}/{Sr} whole rock) age has been identified in Silurian metasediments of the Sierra Grande Formation. Bands of deformation in Sierra Grande quartzites indicate right lateral wrenching in a N-S direction. Contraction in a NE-SW direction is evidenced by folding. Three stages of tectonic evolution can be discerned for the above regions: (1) Early Paleozoic platform sedimentation, punctuated by episodes of accelerated subsidence during the Silurian and early Devonian, as shown by transgressive episodes, (2) late Paleozoic sedimentation and deformation, and (3) Meso-Cenozoic extensional inversion due to the South Atlantic opening. The late Paleozoic sedimentation and deformation (stage 2) includes late Carboniferous-earliest Permian glacial deposits of the Sierras Australes and Colorado offshore basin, deposited during an initial phase of extension, and cratonward foreland subsidence triggered sedimentation of the synorogenic deposits of the Permian Tunas Formation. Tuffs are intercalated in the upper half of this unit. These tuffs are associated with the silicic volcanism along the Andes and Patagonia (Choiyoi magmatic province) that peaked between the late early Permian and late Permian. Likewise, the first widespread appearance of tuffs in the Karoo basin is in the Whitehill Formation, of late early Permian (260 Ma) age. The deformation described in this paper can be considered as part of a large scale intracontinental deformation in SW Gondwanaland inboard of an Andean-type compressive margin. This deformation is characterized by transpression (right lateral wrenching) combined with overthrusting to the NE and N-S horizontal contraction.

Study of the Paleogene carbonate sequence in Campeche and Yucatan, southern Mexico

NASA Astrophysics Data System (ADS)

García Avendaño, A.; Fucugauchi, J. U.

2013-05-01

The relief in the northeastern sector of Yucatan Peninsula is marked in several features, like the Campeche-Hecelchakan fault that indicates a scarp where the carbonate factory was produced from the different processes of eustatic variation throughout all extensions of the shelf. The Campeche scarp is one of the major structures of the peninsula. In this work we present preliminary results of the study on the Paleogene carbonate sequence (stratigraphic age derived from previous works) along a regional transect from the town of Champoton Campeche till Maxcanu town and into nearby Sierra of Ticul in Yucatan state, Mexico. Along this route we carried field work to measure geologic columns and sampled outcrops for petrographic analysis, selected based in litofacies settings in two units Champoton-Maxcanu (CH-CM) and Ticul Sierra (TS), CH-CM unit is formed by interbedded clay, shale, limestone and marl of different thickness, in addition to the content of various bioclasts. ST unit is comprised mostly of collapse breccias. This paper presents the microfacies analysis, directed to highlight changes in lithological horizons within the sequence. The study of carbonates in this study area contributes to the interpretation of the Yucatan geomorphology and development of the carbonate platform, for which the karst topography indicates a gradual subaerial exposure environment. .

A Stable Isotope Study of Fluid-Rock Interactions in the Saddlebag Lake Roof Pendant, Sierra Nevada, California

NASA Astrophysics Data System (ADS)

Lojasiewicz, I.; Hartman, S. M.; Holk, G. J.; Paterson, S. R.

2015-12-01

The Saddlebag Lake Pendant (SLP) is a ~ 100 km2 zone of Ordovician-Cretaceous metasedimentary and metavolcanic rocks just east of the 95-85 Ma Tuolumne Intrusive Complex (TIC) in the Sierra Nevada of central California. Western SLP and adjacent parts of TIC are affected by the Steelhead Lake Shear Zone (SLSZ), with leucogranitic dikes, abundant qz-tm veins, ductile epidote-chlorite alteration, and massive qz veins. While TIC shows uniform stable isotope values, isotope studies of other Sierra Nevada pendants evidence diversity of fluid sources: Jurassic seawater, Cretaceous magmatic fluids, metamorphic fluids, and meteoric-hydrothermal fluids. We conducted a stable isotope study of 49 samples from units across the SLSZ, focusing on the shear zone. Unlike other pendants, both δ18 O and δD values from SLSZ showed great variability, and most samples were not in isotopic equilibrium. Overall, δ18 O mineral values ranged from -1.5‰(plag) to +15.8‰(bt); mineral δD values ranged from -140‰(tm) to -67‰(bt). TIC δ18 O was +7.8 to +10.0 (plag) and +4.8 to +9.2 (tm), normal magmatic values, and δD were -105 to -75. Paleozoic and Triassic metasedimentary units had most qz δ18 O from +11.3 to +15.8, so within metamorphic range, and δD from -100 to -72 (ep and tm). Jurassic metasedimentary units (Sawmill) and Triassic metavolcanics (Koip) had largest isotopic variability: δ18 O qz from +8.1 to +14.8, plag from -1.1 to +11.8, but ep and tm between +1.3 and +9.3 and δD between -108 and -81. All lower (submagmatic) isotopic values were from a wider, possibly transtensional, part of the SLSZ, transected by Sawmill Canyon. Although TIC and many of the Paleozoic units do not show isotopic evidence for alteration, the Koip and Sawmill units were likely infiltrated by later magmatic waters, and then subjected to very localized meteoric water infiltration in the area surrounding Sawmill Canyon.

A Paleomagnetic Investigation of Large-Scale Vertical Axis Rotations in Coastal Sonora: Evidence for Transtensional Proto-Gulf Deformation

NASA Astrophysics Data System (ADS)

Herman, S. W.; Gans, P. B.

2006-12-01

A paleomagnetic investigation into possible vertical axis rotations has been conducted in the Sierra el Aguaje and Sierra Tinajas del Carmen, Sonora, Mexico, in order assess proposed styles for oblique continental rifting in the Gulf of California. Two styles of rifting have been proposed; (1) strain partitioning (Stock and Hodges, 89), and (2) transtension (Gans, 97), for the Proto-Gulf period of the Gulf of California. The presence of large- scale vertical axis rotations would lend weight to the argument for transtension. The Sierra el Aguaje and Sierra Tinajas del Carmen are located in southwestern coastal Sonora, Mexico. The ranges represent the eastern-rifted margin of the central Gulf of California. This is one of the few areas of that margin which is entirely above water, with new ocean crust of the Guaymas basin lying immediately offshore of the western edge of the ranges. The ranges are composed of volcanic units and their corresponding volcaniclastic units that are the result of persistent magmatic activity between 20 and 8.8 Ma, including three packages of basalt and andesite that make excellent paleomagnetic recorders. Based on cross cutting relations and geochronologic data for pre-, syn-, and post-tectonic volcanic units, most of the faulting and tilting in the Sierra El Aguaje and Sierra Tinajas del Carmen is bracketed between 11.9 and 9.0 Ma, thus falling entirely within Proto-Gulf time. Existing field relations suggest the presence of large (>45°) vertical axis rotations in this region. This evidence includes: a) abrupt changes in the strike of tilted strata in different parts of the range b) ubiquitous NE-SW striking faults with left lateral-normal oblique slip, that terminate against major NW-trending right lateral faults, and c) obliquity between the general strike of tilted strata and the strike of faults. The results of the paleomagnetic investigation are consistent with the field evidence and show large clockwise rotations between ~30° and ~100° with no discernable translation. Such large-scale rotations lend credence to the theory that the area inboard of Baja California was experiencing transtension during the Proto-Gulf period, rather than the pure extension that would have been the result of strain partitioning.

Transmission dynamics of Ebola virus disease and intervention effectiveness in Sierra Leone

PubMed Central

Fang, Li-Qun; Yang, Yang; Jiang, Jia-Fu; Yao, Hong-Wu; Kargbo, David; Li, Xin-Lou; Jiang, Bao-Gui; Kargbo, Brima; Tong, Yi-Gang; Wang, Ya-Wei; Liu, Kun; Kamara, Abdul; Dafae, Foday; Kanu, Alex; Jiang, Rui-Ruo; Sun, Ye; Sun, Ruo-Xi; Chen, Wan-Jun; Ma, Mai-Juan; Dean, Natalie E.; Thomas, Harold; Longini, Ira M.; Halloran, M. Elizabeth; Cao, Wu-Chun

2016-01-01

Sierra Leone is the most severely affected country by an unprecedented outbreak of Ebola virus disease (EVD) in West Africa. Although successfully contained, the transmission dynamics of EVD and the impact of interventions in the country remain unclear. We established a database of confirmed and suspected EVD cases from May 2014 to September 2015 in Sierra Leone and mapped the spatiotemporal distribution of cases at the chiefdom level. A Poisson transmission model revealed that the transmissibility at the chiefdom level, estimated as the average number of secondary infections caused by a patient per week, was reduced by 43% [95% confidence interval (CI): 30%, 52%] after October 2014, when the strategic plan of the United Nations Mission for Emergency Ebola Response was initiated, and by 65% (95% CI: 57%, 71%) after the end of December 2014, when 100% case isolation and safe burials were essentially achieved, both compared with before October 2014. Population density, proximity to Ebola treatment centers, cropland coverage, and atmospheric temperature were associated with EVD transmission. The household secondary attack rate (SAR) was estimated to be 0.059 (95% CI: 0.050, 0.070) for the overall outbreak. The household SAR was reduced by 82%, from 0.093 to 0.017, after the nationwide campaign to achieve 100% case isolation and safe burials had been conducted. This study provides a complete overview of the transmission dynamics of the 2014−2015 EVD outbreak in Sierra Leone at both chiefdom and household levels. The interventions implemented in Sierra Leone seem effective in containing the epidemic, particularly in interrupting household transmission. PMID:27035948

The Revolutionary United Front and Child Soldiers during Sierra Leone’s Civil War

DTIC Science & Technology

2015-06-12

Armed Forces served as an ex post facto force during the internal conflict period between the APC and SLPP jockeying for the position of Prime Minister...civil war. Chapter 3, Research Methodology, addresses biases and the reliability of the study regarding the thesis findings. Chapter 4, Analysis

Treatment Seeking and Ebola Community Care Centers in Sierra Leone: A Qualitative Study.

PubMed

Carter, Simone E; O'Reilly, Marion; Frith-Powell, Jack; Umar Kargbo, Alpha; Byrne, Daniel; Niederberger, Eva

2017-01-01

Ebola Treatment Units were able to provide only 60% of necessary treatment beds in Sierra Leone. As a result, the Government of Sierra Leone decided to construct Community Care Centers. These were intended to increase treatment-seeking behavior and reduce the community-level spread of Ebola by facilitating access to care closer to communities. Through qualitative data collection in 3 districts, this study seeks to understand the perceived impact that proximity to such Centers had on treatment-seeking behavior. Feedback from community members and Community Health Volunteers indicates that proximity to treatment reduced fears, especially those arising from the use of ambulances, lack of familiarity with medical Centers, and loss of contact with family members taken for treatment. Participants report that having a Center close to their home enables them to walk to treatment and witness survivors being discharged. Living close to Centers also enables communities to be involved in their design and daily operation, helping to build trust in them as acceptable treatment facilities. Further research is required to understand the appropriate design, operation, and epidemiological impact of Centers. Further investigation should incorporate the effect of an outbreak's severity and the stage (duration) of the outbreak on potential acceptance of Centers.

A Study of Legislative Measures Designed To Facilitate Access to Education and of the Role of the Village School in the Development of Rural Areas.

ERIC Educational Resources Information Center

Gagni, A. O.; Bartels, Francis L.

This report addresses the United Nations Educational Scientific Cultural Organization's (UNESCO) goals for activities related to the development of education in rural areas. Studies were conducted in China, the Philippines, Tanzania, Yugoslavia, Botswana, and Sierra Leone. The first section deals with the analytical study of information on…

Sierra Nevada Mountain Range as seen from STS-58

NASA Image and Video Library

1994-10-20

STS058-72-004 (18 Oct-1 Nov 1993) --- The Sierra Nevada Mountain Range can be seen in this north-looking high oblique view taken in October, 1993, by the STS-58 crew. Visible in the view to the west of the Sierra Nevada are the San Joaquin and Sacramento Valleys of central California. The San Francisco/Oakland Bay Area can be seen to the west of the valley at the extreme left of the photograph. To the east or right of the Sierra Nevada, the basin and Range Region of central and northern Nevada is visible. Mono Lake, Lake Tahoe and Pyramid Lake are also visible in this scene. The long northwest/southeast trending Walker Lane Shear Zone, which lies just to the east (right) of the Sierra Nevada is also visible. Near the top of the view (near the horizon), the snow covered volcanic peak Mount Shasta can be seen. Over 645 kilometers (400 miles) long and from 65 to 130 kilometers (40 to 80 miles) wide, the Sierra Nevada have many peaks in excess of 3,300 meters (11,000 feet) above sea level. A titled fault block in structure (the largest in the United States) and shaped by glaciers during the last ice age over 12,000 years ago, the Sierra Nevada eastern front rises sharply from the Great Basin of Nevada, while its western slope descends gradually to the hills bordering the Central Valley of California. Snow-fed streams supply much of the irrigation water to the Central Valley and to western Nevada and also generate hydroelectricity. Recent above normal precipitation (snowfall) of the last two years has helped in alleviating the drought conditions that had prevailed throughout most of California in the mid and late 1980's and early 1990's.

Biostratigraphy and petrography of upper Paleozoic rocks of Sierra Las Pintas, northern Baja California

NASA Astrophysics Data System (ADS)

Navas-Parejo, Pilar; Lara-Peña, R. Aaron; Torres-Martínez, Miguel Angel; Martini, Michelangelo

2018-07-01

A transported crinoid fauna is herein described for the first time in the Paleozoic succession cropping out in the Sierra Las Pintas, northern Baja California, northwestern Mexico. The fossil association includes Heterostelechus texanus Moore and Jeffords, Preptopremnum laeve? Moore and Jeffords, and Mooreanteris perforatus Moore and Jeffords, which indicates a Middle Pennsylvanian-early Permian time-averaged age. The studied area corresponds with the northernmost outcrop of definitely late Paleozoic deep-water facies in northwestern Mexico and the southern United States. Petrographic analyses indicate that the studied metasandstones were primarily derived from high-grade metamorphic rocks and from a shallow-water platform environment dominated by crinoid meadows. These results allow the correlation of the studied metasedimentary rocks with the Carboniferous Rancho Nuevo Formation of the Sonora allochthon, which crops out in central Sonora. The Sonora allochthon includes an Early Ordovician-Late Pennsylvanian sedimentary succession that was deposited in the oceanic basin located south of the Laurentian craton. Therefore, upper Paleozoic metasedimentary rocks of the Sierra Las Pintas were deposited along the same continental margin of Laurentia as those rocks in the Sonora allochthon, and were mostly derived from metamorphic rocks of the continental craton and by the typical Carboniferous encrinites, which characterize the shallow-water rocks of central and northern Sonora.

The west-wide ponderosa pine levels-of-growing-stock study at age 40

Treesearch

William W. Oliver

2005-01-01

In the 1960s a series of levels-of-growing-stock studies was established in young, even-aged stands throughout the range of ponderosa pine in the western United States. Using a common study plan, installations were begun in the Black Hills of South Dakota, eastern and central Oregon, the Coconino Plateau of Arizona and the west slope of the Sierra Nevada in California...

Exposure of a late cretaceous layered mafic-felsic magma system in the central Sierra Nevada batholith, California

USGS Publications Warehouse

Coleman, D.S.; Glazner, A.F.; Miller, J.S.; Bradford, K.J.; Frost, T.P.; Joye, J.L.; Bachl, C.A.

1995-01-01

New U-Pb zircon ages for the Lamarck Granodiorite, associated synplutonic gabbro and diorite plutons, and two large mafic intrusive complexes that underlie them in the Sierra Nevada batholith are 92??1 Ma. These ages establish the Late Cretaceous as a period of extensive mafic-felsic magmatism in the central part of the batholith, and confirm the significance of mafic magmatism in the evolution of the voluminous silicic plutions in the Sierran arc. The lack of significant zircon inheritance in any of the units analyzed supports isotopic evidence that the Lamarck and other Late Cretaceous Sierran plutons were derived predominantly from young crust. Recognition of an extensive mafic-felsic magma system in the Sierra Nevada batholith emphasizes the importance of basaltic liquids in the evolution of continental crust in arc settings. ?? 1995 Springer-Verlag.

Preliminary report on radioactive conglomerates of Middle Precambrian age in the Sierra Madre and Medicine Bow Mountains of southeastern Wyoming

USGS Publications Warehouse

Houston, Robert Stroud; Graff, P.J.; Karlstrom, K.E.; Root, Forrest

1977-01-01

Middle Precambrian miogeosynclinal metasedimentary rocks o# the Sierra Madre and Medicine Bow Mountains of southeastern Wyoming contain radioactive quartz-pebble conglomerates of possible economic interest. These conglomerates do not contain ore-grade uranium in surface outcrops, but an earlier report on the geochemistry of the Arrastre Lake area of the Medicine Bow Mountains shows that ore-grade deposits may be present in the subsurface. This report describes the stratigraphy of the host metasedimentary rocks and the stratigraphic setting of the radioactive conglomerates in both the Sierra Madre and Medicine Bow Mountains, and compares these rock units with those of the Blind River-Elliot Lake uranium district in Canada. The location of radioactive .conglomerates is given so that further exploration may be undertaken by interested parties.

American Colony in Africa: Lessons Learned from Other Former Colonial Powers in West Africa That Can Be Applied to the United States’ Relationship with Liberia

DTIC Science & Technology

2016-06-10

ultimate success or failure of Liberia in post -colonial Africa. Liberia’s three neighboring countries: Côte d’Ivoire, Sierra Leone, and Guinea all...Liberia in post -colonial Africa. Liberia’s three neighboring countries: Côte d’Ivoire, Sierra Leone, and Guinea all have unique relationships with...between Liberia and the US, both countries have had significant issues defining their post -colonial relationship with each other. Though the US has many

Correlations and Areal Distribution of the Table Mountain Formation, Stanislaus Group; Central Sierra Nevada, California

NASA Astrophysics Data System (ADS)

Torrez, G.; Carlson, C. W.; Putirka, K. D.; Pluhar, C. J.; Sharma, R. K.

2011-12-01

Late Cenozoic evolution of the western Cordillera is a matter of ongoing debate in geologic studies. Volcanic deposits within, and adjacent to the Sierra Nevada have played a significant role in many of these debates. With local faulting coincident with eruption of members of the Stanislaus Group at ca. 38°N, the composition and correlation of these volcanics can greatly aid our understanding of Sierra Nevada tectonics. At the crest of the central Sierra Nevada, 23 trachyandesite lava flows of the Table Mountain Formation, dated at ~10 Ma, cap Sonora Peak. These 23 flows compose the thickest and most complete known stratigraphic section of the Table Mountain Formation in the region. Located ~12 km east of Sonora Peak are 16 flows of trachyandesite at Grouse Meadow. We have collected a detailed set of geochemical and paleomagnetic data for flows of these two sections at Sonora Peak and Grouse Meadows in an attempt to correlate volcanic, paleomagnetic and structural events related to uplift and extension in the Sierra Nevada and the Walker Lane. Correlation of individual flows is possible based on: stratigraphic order, temporal gaps in deposition as determined by paleomagnetic remanence direction and nonconformities, and flow geochemistry. These correlations allow us to infer source localities, flow directions, and temporal changes in flow routes. The large number of flows present at Grouse Meadow provides an additional data set from which to correlate various localities in the region to those units not represented at Sonora Peak. Several flows which occur in the upper portions of the Sonora Peak and Grouse Meadow stratigraphic sections do not correlate between these localities. The causes of stratigraphic discontinuity potentially represent: tectonic isolation across the Sierran Crest, topographic isolation by the emplacement of younger flows, or the combination of the two. Additional to the correlation of individual flows at these localities, this study shows a significant shift in geochemistry across a stratigraphic boundary at both localities.

Current status of experimental paired-watershed research in the USDA Forest Service

Treesearch

Robert R. Ziemer; Douglas F. Ryan

2000-01-01

The first paired-watershed experiment on forested lands in the United States was conducted by the USDA Forest Service from 1909-1928 near Wagon Wheel Gap in Colorado. By the 1930's, experimental watershed studies had been initiated in southern California (San Dimas), Arizona (Sierra Ancha), and North Carolina (Coweeta). By the 1960's, there were 150...

The metamorphic basement of the southern Sierra de Aconquija, Eastern Sierras Pampeanas: Provenance and tectonic setting of a Neoproterozoic back-arc basin

NASA Astrophysics Data System (ADS)

Cisterna, Clara Eugenia; Altenberger, Uwe; Mon, Ricardo; Günter, Christina; Gutiérrez, Antonio

2018-03-01

The Eastern Sierras Pampeanas are mainly composed of Neoproterozoic-early Palaeozoic metamorphic complexes whose protoliths were sedimentary sequences deposited along the western margin of Gondwana. South of the Sierra de Aconquija, Eastern Sierras Pampeanas, a voluminous metamorphic complex crops out. It is mainly composed of schists, gneisses, marbles, calk-silicate schists, thin layers of amphibolites intercalated with the marbles and granitic veins. The new data correlate the Sierra de Aconquija with others metamorphic units that crop out to the south, at the middle portion of the Sierra de Ancasti. Bulk rock composition reflects originally shales, iron rich shales, wackes, minor litharenites and impure limestones as its protoliths. Moreover, comparisons with the northern Sierra de Aconquija and from La Majada (Sierra de Ancasti) show similar composition. Amphibolites have a basaltic precursor, like those from the La Majada (Sierra de Ancasti) ones. The analyzed metamorphic sequence reflects low to moderate weathering conditions in the sediments source environment and their chemical composition would be mainly controlled by the tectonic setting of the sedimentary basin rather than by the secondary sorting and reworking of older deposits. The sediments composition reveal relatively low maturity, nevertheless the Fe - shale and the litharenite show a tendency of minor maturity among them. The source is related to an acid one for the litharenite protolith and a more basic to intermediate for the other rocks, suggesting a main derivation from intermediate to felsic orogen. The source of the Fe-shales may be related to and admixture of the sediments with basic components. Overall the composition point to an upper continental crust as the dominant sediment source for most of the metasedimentary rocks. The protolith of the amphibolites have basic precursors, related to an evolving back-arc basin. The chemical data in combination with the specific sediment association (wackes, shales, Fe-shales and minor litharenites) are characteristic for turbidity currents deposits along tectonically active region. They are also commonly associated with calcareous clays (marbles), commonly observed in the evolution of basins with slope and shelf derived carbonate turbidites. The amphibolites members are probably derived from lava-flows synchronous with the sedimentation during the basin evolution. The basin was controlled by a continental island arc possible evolving to a back-arc setting, as indicated for the mixed nature of the inferred source. The metasedimentary sequence from the Cuesta de La Chilca have petrographic, structural and strong chemical similarities, building a north-south striking belt from the north of the Sierra de Aconquija and to the south along the Sierra de Ancasti (La Majada area). The observed similarities allow to present this portion of the Eastern Sierras Pampeanas as a crustal block that records the sedimentary sequences developed along the geodynamic context of the southwestern margin of Gondwana during the Neoproterozoic and Early Palaeozoic.

Status of the Sierra Nevada: the Sierra Nevada Ecosystem Project

USGS Publications Warehouse

Erman, Don C.; ,

1997-01-01

The Sierra Nevada ecosystem project was requested by Congress in the Conference Report for Interior and related Agencies 1993 Appropriation Act, which authorized funds for a scientific review of the remaining old growth in the national forests of the Sierra Nevada in California, and for a study of the entire Sierra Nevada ecosystem by an independent panel of scientists, with expertise in diverse areas related to this issue. This CD-ROM is a digital version of the set of reports titled 'Sierra Nevada Ecosystem Project, final report to Congress' published in paper form by the Centers for Water and Wildland Resources of the University of California, Davis.

Effects of Pleistocene environmental changes on the distribution and community structure of the mammalian fauna of Mexico

NASA Astrophysics Data System (ADS)

Ceballos, Gerardo; Arroyo-Cabrales, Joaquín; Ponce, Eduardo

2010-05-01

Biological communities in Mexico experienced profound changes in species composition and structure as a consequence of the environmental fluctuations during the Pleistocene. Based on the recent and fossil Mexican mammal checklists, we determine the distribution, composition, diversity, and community structure of late Pleistocene mammalian faunas, and analyze extinction patterns and response of individual species to environmental changes. We conclude that (1) differential extinctions occurred at family, genus, and species level, with a major impact on species heavier than 100 kg, including the extinction all proboscideans and several ruminants; (2) Pleistocene mammal communities in Mexico were more diverse than recent ones; and (3) the current assemblages of species are relatively young. Furthermore, Pleistocene relicts support the presence of biogeographic corridors; important refugia existed as well as centers of speciation in isolated regions. We identified seven corridors: eastern USA-Sierra Madre Oriental corridor, Rocky Mountains-Sierra Madre Occidental corridor, Central United States-Northern Mexico corridor, Transvolcanic Belt-Sierra Madre del Sur corridor, western USA-Baja California corridor, Tamaulipas-Central America gulf lowlands corridor, and Sonora-Central America Pacific lowlands corridor. Our study suggests that present mammalian assemblages are very different than the ones in the late Pleistocene.

Defense.gov Special Report: DoD Helps Fight Ebola in West Africa

Science.gov Websites

Assistance at a Glance Health Care Training Infographic #1 Ebola Treatment Units/Monrovian Medical Unit , Liberia and Sierra Leone. Story Medical Countermeasures Help Ebola Crisis Since 2003, the Defense Threat Reduction Agency has invested more than $300 million to develop medical countermeasures against hemorrhagic

Detrital zircon U-Pb reconnaissance of the Franciscan subduction complex in northwestern California

USGS Publications Warehouse

Dimitru, Trevor; Ernst, W. Gary; Hourigan, Jeremy K.; McLaughlin, Robert J.

2015-01-01

In northwestern California, the Franciscan subduction complex has been subdivided into seven major tectonostratigraphic units. We report U-Pb ages of ≈2400 detrital zircon grains from 26 sandstone samples from 5 of these units. Here, we tabulate each unit's interpreted predominant sediment source areas and depositional age range, ordered from the oldest to the youngest unit. (1) Yolla Bolly terrane: nearby Sierra Nevada batholith (SNB); ca. 118 to 98 Ma. Rare fossils had indicated that this unit was mostly 151-137 Ma, but it is mostly much younger. (2) Central Belt: SND; ca. 103 too 53 Ma (but poorly constrained), again mostly younger than previously thought. (3) Yager terrane: distant Idaho batholith (IB); ca. 52 to 50 Ma. Much of the Yager's detritus was shed during major core complex extension and erosion in Idaho that started 53 Ma. An eocene Princeton River-Princeton submarine canyon system transported this detritus to the Great Valley forearc basin and thence to the Franciscan trench. (4) Coastal terrane: mostly IB, ±SNB, ±nearby Cascade arc, ±Nevada Cenozoic ignimbrite belt; 52 to <32 Ma. (5) King Range terrane: dominated by IB and SNB zircons; parts 16-14 Ma based on microfossils. Overall, some Franciscan units are younger than previously thought, making them more compatible with models for the growth of subduction complexes by positive accretion. From ca. 118 to 70 Ma, Franciscan sediments were sourced mainly from the nearby Sierra Nevada region and were isolated from southwestern US and Mexican sources. From 53 to 49 Ma, the Franciscan was sourced from both Idaho and the Sierra Nevada. By 37-32 Ma, input from Idaho had ceased. The influx from Idaho probably reflects major tectonism in Idaho, Oregon, and Washington, plus development of a through-going Princeton River to California, rather than radical changes in the subduction system at the Franciscan trench itself.

KSC-2012-3149

NASA Image and Video Library

2012-05-30

LOUISVILLE, Colo. – An Erickson Air-Crane helicopter lifts Sierra Nevada Corporation Space Systems’ Dream Chaser full-scale test vehicle to verify proper aerodynamic flight performance near the Rocky Mountain Metropolitan Airport in Jefferson County, Colo. This captive-carry test is one of several milestones the company is meeting during its partnership with NASA’s Commercial Crew Program CCP. Data from this test will provide SNC an early opportunity to evaluate and prove hardware, facilities and ground operations in preparation for approach and landing tests scheduled for later this year. In 2011, NASA selected Sierra Nevada during Commercial Crew Development Round 2 CCDev2) activities to mature the design and development of a crew transportation system with the overall goal of accelerating a United States-led capability to the International Space Station. The goal of CCP is to drive down the cost of space travel as well as open up space to more people than ever before by balancing industry’s own innovative capabilities with NASA's 50 years of human spaceflight experience. Six other aerospace companies also are maturing launch vehicle and spacecraft designs under CCDev2, including Alliant Techsystems Inc. ATK, The Boeing Co., Excalibur Almaz Inc., Blue Origin, Space Exploration Technologies SpaceX, and United Launch Alliance ULA. For more information, visit www.nasa.gov/commercialcrew. Image credit: Sierra Nevada Corp.

KSC-2012-3150

NASA Image and Video Library

2012-05-30

LOUISVILLE, Colo. – Sierra Nevada Corporation Space Systems’ Dream Chaser full-scale test vehicle is lifted by an Erickson Air-Crane helicopter to verify proper aerodynamic flight performance near the Rocky Mountain Metropolitan Airport in Jefferson County, Colo. This captive-carry test is one of several milestones the company is meeting during its partnership with NASA’s Commercial Crew Program CCP. Data from this test will provide SNC an early opportunity to evaluate and prove hardware, facilities and ground operations in preparation for approach and landing tests scheduled for later this year. In 2011, NASA selected Sierra Nevada during Commercial Crew Development Round 2 CCDev2) activities to mature the design and development of a crew transportation system with the overall goal of accelerating a United States-led capability to the International Space Station. The goal of CCP is to drive down the cost of space travel as well as open up space to more people than ever before by balancing industry’s own innovative capabilities with NASA's 50 years of human spaceflight experience. Six other aerospace companies also are maturing launch vehicle and spacecraft designs under CCDev2, including Alliant Techsystems Inc. ATK, The Boeing Co., Excalibur Almaz Inc., Blue Origin, Space Exploration Technologies SpaceX, and United Launch Alliance ULA. For more information, visit www.nasa.gov/commercialcrew. Image credit: Sierra Nevada Corp.

KSC-2012-3148

NASA Image and Video Library

2012-05-30

LOUISVILLE, Colo. – Sierra Nevada Corporation Space Systems’ Dream Chaser full-scale test vehicle is lifted by an Erickson Air-Crane helicopter to verify proper aerodynamic flight performance near the Rocky Mountain Metropolitan Airport in Jefferson County, Colo. This captive-carry test is one of several milestones the company is meeting during its partnership with NASA’s Commercial Crew Program CCP. Data from this test will provide SNC an early opportunity to evaluate and prove hardware, facilities and ground operations in preparation for approach and landing tests scheduled for later this year. In 2011, NASA selected Sierra Nevada during Commercial Crew Development Round 2 CCDev2) activities to mature the design and development of a crew transportation system with the overall goal of accelerating a United States-led capability to the International Space Station. The goal of CCP is to drive down the cost of space travel as well as open up space to more people than ever before by balancing industry’s own innovative capabilities with NASA's 50 years of human spaceflight experience. Six other aerospace companies also are maturing launch vehicle and spacecraft designs under CCDev2, including Alliant Techsystems Inc. ATK, The Boeing Co., Excalibur Almaz Inc., Blue Origin, Space Exploration Technologies SpaceX, and United Launch Alliance ULA. For more information, visit www.nasa.gov/commercialcrew. Image credit: Sierra Nevada Corp.

Curriculum Diversification Re-examined--A Case Study of Sierra Leone.

ERIC Educational Resources Information Center

Wright, Cream A. H.

This paper deals with a case study of secondary curriculum diversification as a vocationalization strategy in Sierra Leone. It explores diversification issues from four crucial standpoints that are distinct but highly interrelated. First, diversification is dealt with as a policy that was adopted and actively pursued by Sierra Leone for over a…

Biosphere and atmosphere interactions in Sierra Nevada forests

Treesearch

Allen H. Goldstein

2004-01-01

In the Sierra Nevada, studies are being conducted to assess the impacts of both anthropogenic and biogenic hydrocarbon emissions on regional tropospheric ozone and fine aerosol production. Impacts of ozone deposition and management practices on ecosystem health are also being studied. Human-induced changes in regional air quality have consequences for Sierra Nevada...

Mountains, fire, fire suppression, and the carbon cycle in the western United States

Treesearch

David Schimel

2004-01-01

Most mountain regions in the western United States are covered by forests, which are for the most part recovering from historical harvesting and have been experiencing active fire suppression over approximately the past 100 years (Tilman and others 2000). Whereas many western landscapes are currently perceived as pristine natural systems, the Rockies, Sierra Nevada,...

Chapter 13. Current management situation: Great gray owls

Treesearch

Jon Verner

1994-01-01

The breeding range of great gray owls (Strix nebulosa) in the United States includes portions of Alaska, mountains in the western United States including portions of the Cascades and Sierra Nevada ranges and the northern Rockies, and portions of Minnesota, Michigan, Wisconsin, and New York (see Chapter 14 and Map 3). The species is sometimes observed...

Ebola virus disease cluster in the United States--Dallas County, Texas, 2014.

PubMed

Chevalier, Michelle S; Chung, Wendy; Smith, Jessica; Weil, Lauren M; Hughes, Sonya M; Joyner, Sibeso N; Hall, Emily; Srinath, Divya; Ritch, Julia; Thathiah, Prea; Threadgill, Heidi; Cervantes, Diana; Lakey, David L

2014-11-21

Since March 10, 2014, Guinea, Liberia, and Sierra Leone have experienced the largest known Ebola virus disease (Ebola) epidemic with approximately 13,000 persons infected as of October 28, 2014. Before September 25, 2014, only four patients with Ebola had been treated in the United States; all of these patients had been diagnosed in West Africa and medically evacuated to the United States for care.

Geologic studies in the Sierra de Pena Blanca, Chihuahua, Mexico

NASA Astrophysics Data System (ADS)

Reyes-Cortes, Ignacio Alfonso

The Sierra del Cuervo has been endowed with uranium mineralization, which has attracted many geological studies, and recently the author was part of a team with the goal of selecting a site of a radioactive waste repository. The first part of the work adds to the regional framework of stratigraphy and tectonics of the area. It includes the idea of a pull apart basin development, which justifies the local great thickness of the Cuervo Formation. It includes the regional structural frame work and the composite stratigraphic column of the Chihuahua Trough and the equivalent Cretaceous Mexican Sea. The general geologic features of the NE part of the Sierra del Cuervo are described, which include the folded ignimbrites and limestones in that area; the irregular large thicknesses of the Cuervo Formation; and the western vergence of the main folding within the area. Sanidine phenocrystals gave ages of 54.2 Ma and 51.8 Ma ± 2.3 Ma. This is the first time these dates have been reported in print. This age indicates a time before the folded structures which outcrop in the area, and 44 Ma is a date after the Cuervo Formation was folded. The Hidalgoan orogeny cycle affected the rocks between this lapse of time. Since then the area has been partially affected by three tensional overlapped stages, which resulted in the actual Basin and Range physiography. The jarosite related to the tectonic activity mineralization has been dated by the Ar-Ar method and yields an age of 9.8 Ma. This is the first report of a date of mineralization timing at Pena Blanca Uranium District in the Sierra del Cuervo. These are some of the frame work features that justify the allocation of a radioactive waste repository in the Sierra del Cuervo. An alluvial fan system within the Boquilla Colorada microbasin was selected as the best target for more detailed site assessment. The study also included the measurement of the alluvium thicknesses by geoelectric soundings; studies of petrography and weathered grade of the rock units; and the possible paths of potential leachate through the geologic media. The last part of the work relates to the natural analog of the Yucca Mountain, the Nopal I orebody, which is compared and found similar in its geologic frame work, in the lithologic units and their weathering, in the stratigraphic relationships with the vitrophyres and tuff horizons, in the climatic dryness, in the regional water table depth and the hydrologic features, in the ignimbritic units mineralogy, and in the radioactive waste fuel compared to the ore mineralogy of the Nopal I. There are mineralogic determinations of the fracture fill material in the orebody and host rock; detailed mapping of the fractures and surface alterations; and gamma ray grid measurements and electromagnetic soundings. All these studies indicate a support criteria to take the Nopal I as a natural analogue of the Yucca Mountain repository. The total evolution of the Nopal I orebody is exposed in the walls and floors of the +00 and +10 levels, which are ready to perform final safety tests in order to compare it with the future Yucca Mountain repository behavior. The Nopal in orebody has been there for several hundred of thousands and may be millions of years in an natural equilibrium with the surrounding environment. (Abstract shortened by UMI.)

Crustal structure in the western United States; study of seismic propagation paths and regional traveltimes in the California-Nevada region

USGS Publications Warehouse

Roller, J.C.; Jackson, W.H.; Cooper, J.F.; Martina, B.A.

1963-01-01

The U.S. Geological Survey, with the assistance of United ElectroDynamics, Inc., completed ten weeks of seismic-refraction field work during the summer of 1962 in the southwestern part of the United States. This work was a continuation of a program initiated in 1961 to study traveltimes and seismic propagation paths in the earth?s crust and upper mantle in the western United States. A total of 761 seismograms were recorded along 10 profiles from 86 explosions at 18 shotpoints. Analysis of the data is continuing, but a few conclusions can be made from a preliminary study: (1) Variations in traveltimes in the Basin and Range province are large but measurable, and perhaps predictable. (2) Traveltimes of seismic waves in adjacent geologic provinces are usually significantly different. (3) The velocity of Pg along all of the profiles recorded in 1962 ranges from 5.0 to 6.5 km/sec, and averages 6.0 km/sec. (4) The average velocity of Pg in extreme northern Nevada and southern Idaho is 5.6 km/sec, and it is 6.1 km/sec in most of Nevada and California. (5) The average velocity of Pn is 7–9 km/ sec and ranges from 7.85 to 7.95 km/sec on reversed profiles where the true Pn velocity could be computed. (6) A shallow "intermediate" layer with a velocity of approximately 6.8 km/sec was found in the Snake River Plain. (7) Refraction arrivals from the mantle (Pn) were recorded in the Sierra Nevada. They indicate that the thickness of the crust in the Sierra Nevada is much greater than that in the Basin and Range province. (8) Many refinements in field techniques were made during the 1962 field season.

Groundwater quality in the Madera and Chowchilla subbasins of the San Joaquin Valley, California

USGS Publications Warehouse

Shelton, Jennifer L.; Fram, Miranda S.; Belitz, Kenneth

2013-01-01

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 untreated groundwater quality and increases public access to groundwater-quality information. The Madera and Chowchilla subbasins of the San Joaquin Valley constitute one of the study units being evaluated. The Madera-Chowchilla study unit is about 860 square miles and consists of the Madera and Chowchilla groundwater subbasins of the San Joaquin Valley Basin (California Department of Water Resources, 2003; Shelton and others, 2009). The study unit has hot, dry summers and cool, moist winters. Average annual rainfall ranges from 11 to 15 inches, most of which occurs between November and February. The main surface-water features in the study unit are the San Joaquin, Fresno, and Chowchilla Rivers, and the Madera and Chowchilla canals. Land use in the study unit is about 69 percent (%) agricultural, 28% natural (mainly grasslands), and 3% urban. The primary crops are orchards and vineyards. The largest urban area is the city of Madera. The primary aquifer system is defined as those parts of the aquifer corresponding to the perforated intervals of wells listed in the California Department of Public Health (CDPH) database. In the Madera-Chowchilla study unit, these wells typically are drilled to depths between 200 and 800 feet, consist of a solid casing from land surface to a depth of about 140 to 400 feet, and are perforated below the solid casing. Water quality in the primary aquifer system may differ from that in the shallower and deeper parts of the aquifer system. The primary aquifer system in the study unit consists of Quaternary-age alluvial-fan and fluvial deposits that were formed by the rivers draining the Sierra Nevada. Sediments consist of gravels, sands, silts, and clays and generally are coarser closest to the Sierra Nevada and become finer towards the center of the basin. The structure and composition of the deposits in the Madera-Chowchilla study unit are different from those in other parts of the eastern San Joaquin Valley because the Fresno and Chowchilla Rivers primarily drain the Sierra Nevada foothills, whereas the larger rivers drain higher elevations with greater sediment supply. These differences in the sources of sediments are important because they may affect the groundwater chemistry and the physical structure of the sedimentary deposits. Some of the clay layers are lacustrine deposits, the most extensive of which, the Corcoran Clay, underlies the western part of the study unit and divides the primary aquifer system into an unconfined to semi-confined upper system and a largely confined lower system. Regional lateral flow of groundwater is southwest towards the valley trough. Irrigation return flows are the major source of groundwater recharge, and groundwater pumping is the major source of discharge. Groundwater on a lateral flow path may be repeatedly extracted by pumping wells and reapplied at the surface multiple times before reaching the valley trough, resulting in a substantial component of downward vertical flow (Burow and others, 2004; Phillips and others, 2007; Faunt, 2009). This flow pattern enhances movement of water from shallow depths to the primary aquifer system.

Evidence of Regional Warming during the 20th Century in Alpine and Subalpine Lakes in the Western United States

NASA Astrophysics Data System (ADS)

Porinchu, D.; Reinemann, S.; Potito, A.; Moser, K.; MacDonald, G.; Munroe, J.; Mark, B.; Box, J.

2007-12-01

Subfossil midge analyses have been used to develop high-resolution (sub-decadal) reconstructions of 20th century temperature change in the Sierra Nevada, CA with success. Expansion of this earlier work to additional sites in the western United States suggests that a widespread increase in lake water temperatures has occurred in this region during the late 20th and early 21st centuries. Inference models for summer surface water temperature (SSWT) were developed combining midge abundance data from 56 lakes in the eastern Sierra Nevada, California, with subfossil midge remains from the Uinta Mountains, UT. The newly merged Sierra Nevada-Uinta Mountains calibration set contains a greater diversity of chironomid assemblages and spans a wider SSWT range than the previously published Sierra Nevada calibration set. The lakes in the merged calibration set spanned elevation, depth, and SSWT temperature ranges of 900 m, 12.7 m, and 11.3 °C, respectively. A robust inference model for SSWT (3-component WA-PLS), based on 90 lakes, had a high coefficient of determination (r2jack = 0.66) and a low RMSEP (1.4 °C). The midge-based SSWT inference model was applied to subfossil chironomid remains extracted from well-dated sediment sequences recovered from alpine and subalpine lakes in the Sierra Nevada, CA, Snake Range, NV and Uinta Mountains, UT. A close correspondence exists between the chironomid-inferred temperature profiles for the 20th and 21st centuries and mean July or summer temperatures measured at nearby meteorological stations. Application of this midge-based SSWT inference model to other intact, late Quaternary sedimentary sequences found in subalpine and alpine lakes in the Great Basin will help resolve the impact of late Quaternary and recent climate change in this region, improve our understanding of regional climate and aquatic ecosystem variability, and can be used to monitor the effects of climate change on aquatic ecosystems and establish 'baseline' conditions against which future biotic changes can be compared.

Evidence from the lamarck granodiorite for rapid late cretaceous crust formation in California

USGS Publications Warehouse

Coleman, D.S.; Frost, T.P.; Glazner, A.F.

1992-01-01

Strontium and neodymium isotopic data for rocks from the voluminous 90-million-year-old Lamarck intrusive suite in the Sierra Nevada batholith, California, show little variation across a compositional range from gabbro to granite. Data for three different gabbro intrusions within the suite are identical within analytical error and are consistent with derivation from an enriched mantle source. Recognition of local involvement of enriched mantle during generation of the Sierran batholith modifies estimates of crustal growth rates in the United States. These data indicate that parts of the Sierra Nevada batholith may consist almost entirely of juvenile crust added during Cretaceous magmatism.

A paleomagnetic investigation of vertical-axis rotations in coastal Sonora, Mexico: Evidence for distributed transtensional deformation during the Proto-Gulf shift from a subduction-dominated to transform-dominated plate boundary in the Gulf of California

NASA Astrophysics Data System (ADS)

Herman, Scott William

The history of late Miocene (Proto-Gulf) deformation on the Sonoran margin of the Gulf of California is key to understanding how Baja California was captured by the Pacific plate and how strain was partitioned during the Proto-Gulf period (12.5-6 Ma). The Sierra el Aguaje and Sierra Tinajas del Carmen are located in southwestern coastal Sonora, Mexico, and represent the eastern rifted margin of the central Gulf of California. The ranges are composed of volcanic units and their corresponding volcaniclastic units which are the result of persistent magmatic activity between 20 and 8.8 Ma, including three packages of basalt and andesite that make excellent paleomagnetic recorders. Based on cross cutting relations and geochronologic data for pre-, syn-, and post-tectonic volcanic units, most of the faulting and tilting in the Sierra El Aguaje is bracketed between 11.9 and 9.0 Ma, thus falling entirely within Proto-Gulf time. A paleomagnetic investigation into possible vertical axis rotations in the Sierra el Aguaje has uncovered evidence of clockwise rotations between ~13º and ~105º with possible translations. These results are consistent with existing field relations, which suggest the presence of large (>45°) vertical axis rotations in this region. This evidence includes: a) abrupt changes in the strike of tilted strata in different parts of the range, including large domains characterized by E-W strikes b) ubiquitous NE-SW striking faults with left lateral-normal oblique slip, that terminate against major NW-trending right lateral faults, and c) obliquity between the general strike of tilted strata and the strike of faults. These rotations occurred after 12 Ma and largely prior to 9 Ma, thus falling into the Proto-Gulf period. Such large-scale rotations lend credence to the theory that the area inboard of Baja California was experiencing transtension during the Proto-Gulf period, rather than the pure extension that would be the result of strain partitioning between Sonora and the Tosco-Abreojos fault offshore Baja California.

Plutonism in the central part of the Sierra Nevada Batholith, California

USGS Publications Warehouse

Bateman, Paul C.

1992-01-01

The Sierra Nevada batholith comprises the plutonic rocks of Mesozoic age that underlie most of the Sierra Nevada, a magnificent mountain range that originated in the Cenozoic by the westward tilting of a huge block of the Earth's crust. Scattered intrusions west of the batholith in the western metamorphic belt of the Sierra Nevada and east of the Sierra Nevada in the Benton Range and the White and Inyo Mountains are satellitic to but not strictly parts of the Sierra Nevada batholith. Nevertheless, all the plutonic rocks are related in origin. The batholith lies along the west edge of the Paleozoic North American craton, and Paleozoic and early Mesozoic oceanic crust underlies its western margin. It was emplaced in strongly deformed but weakly metamorphosed strata ranging in age from Proterozoic to Cretaceous. Sedimentary rocks of Proterozoic and Paleozoic age crop out east of the batholith in the White and Inyo Mountains, and metamorphosed sedimentary and volcanic rocks of Paleozoic and Mesozoic age crop out west of the batholith in the western metamorphic belt. A few large and many small, generally elongate remnants of metamorphic rocks lie within the batholith. Sparse fossils from metasedimentary rocks and isotopic ages for metavolcanic rocks indicate that the metamorphic rocks in the remnants range in age from Early Cambrian to Early Cretaceous. Within the map area (the Mariposa 1 0 by 2 0 quadrangle), the bedding, cleavage, and axial surfaces of folds generally trend about N. 35 0 W., parallel to the long axis of the Sierra Nevada. The country rocks comprise strongly deformed but generally coherent sequences; however, some units in the western metamorphic belt may partly consist of melanges. Most sequences are in contact with other sequences, at least for short distances, but some sequences within the batholith are bounded on one or more sides by plutonic rocks. Proterozoic and Paleozoic sedimentary strata east of the Sierra Nevada and Paleozoic strata in remnants of country rocks within the eastern part of the batholith, although strongly deformed, are autochthonous or have been displaced only short distances, whereas some Mesozoic strata in the western metamorphic belt may be allochthonous. Probably the strata in the western metamorphic belt were deposited in marginal basins and island arcs, but the possibility that they were transported from distant places has not been disproved. All the country rocks have been strongly deformed, most of them more than once. Tectonic disturbances occurred during the Devonian and Mississippian (Antler? orogeny), the Permian and (or) Early Triassic (Sonoman? orogeny), the Late Jurassic (Nevadan orogeny), and at various other times during emplacement of the batholith and uplift that accompanied and followed its emplacement. The strata in the western metamorphic belt probably were deformed in an early Mesozoic subduction complex. The plutonic rocks range in composition from gabbro to leucogranite, but tonalite, granodiorite, and granite are the most common rock types. Most are medium to coarse grained, but some small rock masses are fine grained. Most have hypidiomorphic-granular textures and are equigranular, but some having compositions close to the boundary between granite and granodiorite contain large crystals of alkali feldspar. Serpentinized ultramafic rocks are present locally in the western metamorphic belt within and adjacent to the Melones fault zone. Except for serpentinized ultramafic rocks, trondhjemite, and most granites, all the plutonic rocks contain significant amounts of hornblende. Most of the granitoids are metaluminous or weakly peraluminous; strongly peraluminous granites are present only in the White Mountains. Most of the granitoids are assigned to units of lithodemic rank, and most of these units are assigned to intrusive suites. Plutons assigned to the same lithodeme are composed of rock of similar composition, fabric, and age and are presumed to h

76 FR 54463 - Proposed Consent Decree, Clean Air Act Citizen Suit

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-01

... lawsuit filed by WildEarth Guardians and Sierra Club in the United States District Court for the Northern District of California: WildEarth Guardians et al. v. Jackson, No. 3:11-cv-00190-WHA (N.D. Cal.). On July 6...

Attracting, Recruiting, and Retaining Qualified Faculty at Community Colleges in Sierra Leone

ERIC Educational Resources Information Center

Betts, Gloria

2017-01-01

This case study was designed to explore policies that were in place to attract, recruit, and retain qualified faculty for 4 community colleges in Sierra Leone. The research was necessitated by the apparent inability of Sierra Leone educators to train and retain faculty possessing the required academic credentials. The research questions were…

Landsat-Derived Estimates of Mangrove Extents in the Sierra Leone Coastal Landscape Complex during 1990–2016

PubMed Central

Trzaska, Sylwia

2017-01-01

This study provides the first assessment of decadal changes in mangrove extents in Sierra Leone. While significant advances have been made in mangrove mapping using remote sensing, no study has documented long-term changes in mangrove extents in Sierra Leone—one of the most vulnerable countries in West Africa. Such understanding is critical for devising regional management strategies that can support local livelihoods. We utilize multi-date Landsat data and cloud computational techniques to quantify spatiotemporal changes in land cover, with focus on mangrove ecosystems, for 1990–2016 along the coast of Sierra Leone. We specifically focus on four estuaries—Scarcies, Sierra Leone, Yawri Bay, and Sherbro. We relied on the k-means approach for an unsupervised classification, and validated the classified map from 2016 using ground truth data collected from Sentinel-2 and high-resolution images and during field research (accuracy: 95%). Our findings indicate that the Scarcies river estuary witnessed the greatest mangrove loss since 1990 (45%), while the Sierra Leone river estuary experienced mangrove gain over the last 26 years (22%). Overall, the Sierra Leone coast lost 25% of its mangroves between 1990 and 2016, with the lowest coverage in 2000, during the period of civil war (1991–2002). However, natural mangrove dynamics, as supported by field observations, indicate the potential for regeneration and sustainability under carefully constructed management strategies. PMID:29267247

Landsat-Derived Estimates of Mangrove Extents in the Sierra Leone Coastal Landscape Complex during 1990-2016.

PubMed

Mondal, Pinki; Trzaska, Sylwia; de Sherbinin, Alex

2017-12-21

This study provides the first assessment of decadal changes in mangrove extents in Sierra Leone. While significant advances have been made in mangrove mapping using remote sensing, no study has documented long-term changes in mangrove extents in Sierra Leone-one of the most vulnerable countries in West Africa. Such understanding is critical for devising regional management strategies that can support local livelihoods. We utilize multi-date Landsat data and cloud computational techniques to quantify spatiotemporal changes in land cover, with focus on mangrove ecosystems, for 1990-2016 along the coast of Sierra Leone. We specifically focus on four estuaries-Scarcies, Sierra Leone, Yawri Bay, and Sherbro. We relied on the k-means approach for an unsupervised classification, and validated the classified map from 2016 using ground truth data collected from Sentinel-2 and high-resolution images and during field research (accuracy: 95%). Our findings indicate that the Scarcies river estuary witnessed the greatest mangrove loss since 1990 (45%), while the Sierra Leone river estuary experienced mangrove gain over the last 26 years (22%). Overall, the Sierra Leone coast lost 25% of its mangroves between 1990 and 2016, with the lowest coverage in 2000, during the period of civil war (1991-2002). However, natural mangrove dynamics, as supported by field observations, indicate the potential for regeneration and sustainability under carefully constructed management strategies.

Summary of Research Activities Academic Departments 1980-1981.

DTIC Science & Technology

1981-10-01

policy issues in these nations. Three regional studies of non-agricultural activities in the Philippines , Malaysia, and Sierra Leone are examined for...AD-AL17 5 291 NAVAL ACADEMY ANNAOIS MD F/6 5/2 SUMMARY OF RESEARCH ACTIVITIES ACADEMIC DEPARTMENTS 1980-1981(U) OCT 81 W L HELFIN UNCLASSIFIED USNA-7...SUMMARY OF RESEARCH ACTIVITIES 1980 - 1981 COMPILED AND EDITED BY PROFESSOR WILSON L. HEFLIN ENGLISH DEPARTMENT DTIC ELECTE I-OCTOBER 1981 JU9 S& UNITED

Dynamic and inertial controls on forest carbon-water relations

NASA Astrophysics Data System (ADS)

Maxwell, T.; Silva, L.; Horwath, W. R.

2017-12-01

This study fuses theory, empirical measurements, and statistical models to evaluate multiple processes controlling coupled carbon-water cycles in forest ecosystems. A series of latitudinal and altitudinal transects across the California Sierra Nevada was used to study the effects of climatic and edaphic gradients on intrinsic water-use efficiency (iWUE) - CO2 fixed per unit of water lost via transpiration - of nine dominant trees species. Transfer functions were determined between leaf, litter, and soil organic matter stable isotope ratios of carbon, oxygen, and nitrogen, revealing causal links between the physiological performance of tree species and stand-level estimations of productivity and water balance. Our results show that species iWUE is governed both by leaf traits (24% of the variation) and edaphic properties, such as parent material and soil development (3% and 12% of the variation, respectively). We show that soil properties combined with isotopic indicators can be used to explain constraints over iWUE by regulating water and nutrient availability across elevation gradients. Based on observed compositional shifts likely driven by changing climates in the region, encroachment of broad leaf trees could lead to an 80% increase in water loss via transpiration for each unit of CO2 fixed in Sierra mixed conifer zones. A combination of field-based, laboratory, and remote sensed data provide a useful framework for differentiating the effect of multiple controls of carbon and water cycles in temperate forest ecosystems.

Assessment of Anemia Knowledge, Attitudes and Behaviors among Pregnant Women in Sierra Leone

ERIC Educational Resources Information Center

M'Cormack, Fredanna A. D.; Drolet, Judy C.

2012-01-01

Introduction: Iron deficiency anemia prevalence of pregnant Sierra Leone women currently is reported to be 59.7%. Anemia is considered to be a direct cause of 3-7% of maternal deaths and an indirect cause of 20-40% of maternal deaths. This study explores knowledge, attitudes, and behaviors of urban pregnant Sierra Leone women regarding anemia.…

Phylogeography and historical demography of the Pacific Sierra mackerel (Scomberomorus sierra) in the Eastern Pacific

PubMed Central

2010-01-01

Background Testing connectivity among populations of exploited marine fish is a main concern for the development of conservation strategies. Even though marine species are often considered to display low levels of population structure, barriers to dispersal found in the marine realm may restrict gene flow and cause genetic divergence of populations. The Pacific Sierra mackerel (Scomberomorus sierra) is a pelagic fish species distributed throughout the tropical and subtropical waters of the eastern Pacific. Seasonal spawning in different areas across the species range, as well as a limited dispersal, may result in a population genetic structure. Identification of genetically discrete units is important in the proper conservation of the fishery. Results Samples collected from the Eastern Pacific, including the areas of main abundance of the species, presented high levels of mtDNA genetic diversity and a highly significant divergence. At least two genetically discrete groups were detected in the northern (Sinaloa) and central areas (Oaxaca and Chiapas) of the species range, exhibiting slight genetic differences with respect to the samples collected in the southern region (Peru), together with a "chaotic genetic patchiness" pattern of differentiation and no evidence of isolation by distance. Historical demographic parameters supported the occurrence of past population expansions, whereas the divergence times between populations coincided with the occurrence of glacial maxima some 220 000 years ago. Conclusions The population genetic structure detected for the Pacific Sierra mackerel is associated with a limited dispersal between the main abundance areas that are usually linked to the spawning sites of the species. Population expansions have coincided with glacial-interglacial episodes in the Pleistocene, but they may also be related to the increase in the SST and with upwelling areas in the EEP since the early Pleistocene. PMID:20438637

Modeling Patterns of Precipitation Phase in the Central Sierra Nevada

NASA Astrophysics Data System (ADS)

Strikas, O.; Pavelsky, T.

2013-12-01

Snowpack provides 75% of summer hydrologic flow in the western United States. This summer flow is vitally important in California, the country's leading producer of agriculture, with $43.5 billion dollars in cash receipts in 2011. Snowpack in the California Sierra Nevada has declined by approximately half from 1900 to 1990. In this study, we use the Weather Research and Forecasting (WRF) regional climate model at a 3km resolution to understand the critical temperature window at which both snow and rain fall for the Central Sierra Nevada during the 2002 water year. Results suggest that temperature and snow fraction [snowfall / (snowfall + rainfall)] share a logistic relationship with the snow fraction being 1 until approximately 272 K, then the snow fraction decreases by approximately 22%/K leveling at 0 snow fraction at 276.5 K. We further examine the spatial patterns of temperatures, precipitation amounts, and precipitation types in the Sierra Nevada to determine the areas of greatest potential snow to rain transition under a future warmer climate. Preliminary results suggest that the high risk areas are at the low to mid elevations. This research provides evidence that even a minor increase in temperature (+0.5 K) will yield changes in spring and summer hydrographs for the region. The spatial variability of IPCC temperature regime change for 2050 and 2100 will be downscaled for a higher resolution prediction of precipitation. It is currently under investigation how the proposed IPCC (A1 and B2) predictions of climate change for the region by 2050 (+2.7 K; +1.6 K ) and 2100 (+4.4 K; +2.7 K) will alter the corresponding annual river hydrographs. Given the complex topography of the Sierra Nevada, several spatial interpolations using GIS and statistical algorithms will be executed to render this high resolution (3km) output. Other future work with collaborators intends to model the agricultural risk associated with our predicted changes. This plot demonstrates the relation between temperature and snow fraction. The red line represents 273 K. The Loess regression (and its standard error) is shown in black (gray). It indicates a snow fraction decrease that begins 272.5 K and finishes with 100% rain at 277.5 K.

Geothermal Energy

DTIC Science & Technology

1975-11-15

temperature conditions, etc. It is also engaged on physiological studies, on studies of nutrition for increasing plants and studies on the agricultural...activity, especially in the Acapulco region. The zones known as Sierra Madre del Sur, Sierra de Chiapas, the Gulf coastal plain and the Yucatan

Surface uplift and atmospheric flow deflection in the Late Cenozoic southern Sierra Nevada

NASA Astrophysics Data System (ADS)

Mix, H.; Caves, J. K.; Winnick, M.; Ritch, A. J.; Reilly, S.; Chamberlain, C. P.

2016-12-01

Given the intimate links between topography, tectonics, climate and biodiversity, considerable effort has been devoted to developing robust elevation histories of orogens. In particular, quantitative geochemical reconstructions using stable oxygen and hydrogen isotopes have been applied to many of the world's mountain belts. Yet after decades of study, determining the Cenozoic surface uplift history of the Sierra Nevada remains a challenge. While geological and geophysical evidence suggests the southern Sierra underwent 1-2 km of Late Cenozoic surface uplift, stable isotope paleoaltimetry studies to date have been restricted to the Basin and Range interior. Recent advances in atmospheric modeling have suggested that such stable isotope records from leeward sites can be affected by the complicating role that sufficiently elevated topography such as the southern (High) Sierra plays in diverting atmospheric circulation. In order to examine the potential role of these terrain blocking effects, we produced stable isotope records from three Late Cenozoic sedimentary basins in the Eastern Sierra and Basin and Range: 1) Authigenic clay minerals in the Mio-Pliocene Verdi Basin (VB), 2) Fluvial and lacustrine carbonates from the Plio-Pleistocene Coso Basin (CB), and 3) Miocene to Holocene pedogenic, fluvial and lacustrine carbonates of Fish Lake Valley (FLV). Whereas both the VB (near present-day Reno) and CB (southern Owens Valley) receive input of water directly from the Sierra crest, FLV is a region of proposed reconvergence of moisture in the Basin and Range. The oxygen isotope records in both CB and FLV increase during the Neogene by approximately 2 ‰, while the hydrogen isotope record of the VB decreases by <10 ‰. These results are consistent with a modestly-elevated Paleogene Sierra of 2 km over which air masses traversed and underwent orographic rainout and Rayleigh distillation. A Neogene pulse of uplift in the southern Sierra could have driven modern flow around the High Sierra, increasing δ18O values in CB and FLV while simultaneously decreasing those of the VB. Future paleoaltimetry studies should evaluate the potential interactions between surface uplift and complex atmospheric circulation, as well as other confounding factors such as changes in moisture source, seasonality and vapor recycling.

Depth to bedrock in the upper San Pedro Valley, Cochise County, southeastern Arizona

USGS Publications Warehouse

Gettings, M.E.; Houser, Brenda B.

2000-01-01

The thickness, distribution, and character of alluvial sediments that were deposited in the structural subbasins of the upper San Pedro basin in southeastern Arizona during the late Cenozoic provide important constraints on ground-water availability of the area. Two sedimentary units are recognized; the Oligocene and Miocene Pantano(?) Formation and an unnamed upper Miocene through lower Pleistocene unit termed basin fill. The complete Bouguer gravity anomaly map shows that there are three major structural subbasins in the upper San Pedro basin north of the international border with Mexico. The Tombstone subbasin is north of Tombstone, and two more are located north and south of Sierra Vista, respectively. This report concentrates on the two subbasins north and south of Sierra Vista. The northern subbasin (termed the Huachuca City subbasin) extends from east of Huachuca City to northeast of Whetstone, and the southern subbasin (termed the Palominas subbasin) extends southward from a line between Nicksville and Hereford to the border. The locations and shapes of these subbasins, thickness of basin fill, and depth to bedrock were estimated using a procedure involving interpolation of (1) the density functions derived in this study, (2) stratigraphic data from water wells, and (3) a residual gravity anomaly grid obtained by subtracting the gravity effects of the bedrock ranges bordering the basin from the complete Bouguer gravity anomaly. This procedure indicates that the subbasins are shallow and contain significant thicknesses of the Pantano(?) Formation in addition to the overlying younger basin fill. The maximum depth to bedrock is about 1,700 m in the Palominas subbasin and 800m in the Huachuca City subbasin; the basin-fill unit occupies the upper 250-350 m in general with local thickenings exceeding 1,000 m in the Palominas subbasin. An east-west trending buried bedrock high beneath Fort Huachuca, Sierra Vista, and Charleston separates the subbasins. The depth to bedrock over this high is 200-500 m and the basin-fill unit ranges from 100 to 200 m thick there. A number of previously unrecognized faults were identified and the lengths of some of the known faults were extended based on reconnaissance geologic mapping, study of driller's logs, interpretation of aerial photographs and thematic mapper satellite images, and inspection of contoured gravity and aeromagnetic anomaly data. Many faults that segment the main San Pedro basin and shape the boundaries of the subbasins are apparently pre-existing faults that have been reactivated by Basin and Range extension.

Virus Genomes Reveal the Factors that Spread and Sustained the West African Ebola Epidemic

DTIC Science & Technology

2016-08-09

Highfield, Southampton SO17 1BJ, UK, 4Flowminder Foundation, Stockholm, Sweden, 5Department of Microbiology and Immunology, Rega Institute, KU Leuven...Sierra Leone, 27Institute of Microbiology , Chinese Academy of Sciences, Beijing 100101, China, 28University of Bristol, BS8 1TD, United Kingdom...29Institute of Microbiology and Infection, University of Birmingham, Birmingham B15 2TT, United Kingdom, 30University of Nebraska Medical Center, Omaha

Estimates of carbon stored in harvested wood products from United States Forest Service's Sierra Nevada Bio-Regional Assessment Area of the Pacific Southwest Region, 1909-2012

Treesearch

Keith Stockmann; Nathaniel Anderson; Jesse Young; Ken Skog; Sean Healey; Dan Loeffler; Edward Butler; J. Greg Jones; James Morrison

2014-01-01

Global forests capture and store significant amounts of carbon through photosynthesis. When carbon is removed from forests through harvest, a portion of the harvested carbon is stored in wood products, often for many decades. The United States Forest Service (USFS) and other agencies are interested in accurately accounting for carbon flux associated with harvested wood...

Krio Language Manual. Revised Edition.

ERIC Educational Resources Information Center

Peace Corps, Freetown (Sierra Leone).

Instructional materials for Krio, the creole spoken in Sierra Leone, are designed for Peace Corps volunteer language instruction and intended for the use of both students and instructors. Fifty-six units provide practice in language skills, particularly oral, geared to the daily language needs of volunteers. Lessons are designed for audio-lingual…

DOD Environmental Policy Implementation: A Unit-Level Assessment.

DTIC Science & Technology

1991-01-01

Moves to Front Burner," Defense/90, March-April: 21-32. Pope, Carl. (1991) "War on Earth," Sierra, Vol 76, No 3, May/June: 54-58. Pressman , Jeffrey L...California Press. Rabe, Barry G. (1986) Fragmentation and Integration in State Environmental Management. Washington, D.C.: The Conser- vation Foundation

Evolution and history of Giant Sequoia

Treesearch

H. Thomas Harvey

1986-01-01

Ancient ancestors of the giant sequoia (Sequoiadendron giganteum [Lindl.] Buchholz) were widespread throughout much of the Northern Hemisphere during the late Mesozoic Period. Climatic conditions changed, forcing the more recent ancestors of present giant sequoia into the southwestern United States. The native range is now restricted to the west slope of the Sierra...

Groundwater Quality in the Central Eastside San Joaquin Valley, California

USGS Publications Warehouse

Belitz, Kenneth; Landon, Matthew K.

2010-01-01

The Central Eastside study unit is located in California's San Joaquin Valley. The 1,695 square mile study unit includes three groundwater subbasins: Modesto, Turlock, and Merced (California Department of Water Resources, 2003). The primary water-bearing units consist of discontinuous lenses of gravel, sand, silt, and clay, which are derived largely from the Sierra Nevada Mountains to the east. Public-supply wells provide most of the drinking water supply in the Central Eastside. Consequently, the primary aquifer in the Central Eastside study unit is defined as that part of the aquifer corresponding to the perforated interval of wells listed in the California Department of Public Health database. Public-supply wells are typically drilled to depths of 200 to 350 feet, consist of solid casing from the land surface to a depth of about 100 to 200 feet, and they are perforated below the solid casing. Water quality in the shallower and deeper parts of the aquifer system may differ from that in the primary aquifer. The Central Eastside study unit has hot and dry summers and cool, moist, winters. Average annual rainfall ranges from 11 to 15 inches. The Stanislaus, Tuolumne, and Merced Rivers, with headwaters in the Sierra Nevada Mountains, are the primary streams traversing the study unit. Land use in the study unit is approximately 59 percent (%) agricultural, 34% natural (primarily grassland), and 7% urban. The primary crops are almonds, walnuts, peaches, grapes, grain, corn, and alfalfa. The largest urban areas (2003 population in parentheses) are the cities of Modesto (206,872), Turlock (63,467), and Merced (69,512). Municipal water use accounts for about 5% of the total water use in the Central Eastside study unit, with the remainder used for irrigated agriculture. Groundwater accounts for about 75% of the municipal supply, and surface water accounts for about 25%. Recharge to the groundwater flow system is primarily from percolation of irrigation return, precipitation, seepage from reservoirs and rivers, and urban return (Burow and others, 2004; Phillips and others, 2007). The primary sources of discharge are pumping for irrigation and municipal supply, evaporation from areas with a shallow depth to water, and discharge to streams. Recharge at shallow depths and pumping from wells at greater depths causes downward movement of groundwater in the aquifer in the Central Eastside. This vertical movement of water has the potential to carry chemical constituents from shallow depths to the greater depths where supply wells commonly are perforated.

Magnetic and gravity anomalies in the Sierra del Padre and Sierra del Tala, San Luis Province, Argentina: evidence of buried mafic ultramafic rocks

NASA Astrophysics Data System (ADS)

Kostadinoff, José; Alfredo Bjerg, Ernesto; Gregori, Daniel; Delpino, Sergio; Dimieri, Luis; Raniolo, Ariel; Mogessie, Aberra; Hoinkes, Georg; Hauzenberger, Christoph; Felfernig, Anja

2001-07-01

This paper presents the results of a geophysical study of the southern portion of the Sierra Grande de San Luis, San Luis Province, Argentina. A 26 mGal amplitude Bouguer anomaly (Charlone anomaly), measuring 40 km long by 7 km wide, between Sierra de los Padres and Zanjitas reflects the presence of high-density rocks located at approximately 2000 m depth. Geophysical models based on more than 300 gravimetric, magnetometric, and geological field measurements and observations suggest that the mafic-ultramafic belt of Sierra Grande de San Luis continues south of San Luis. The low magnitude of the terrestrial magnetic field anomalies indicates that these mafic-ultramafic rocks do not carry a base metal sulfides (BMS) mineralization. The Charlone gravimetric anomaly is generated by a belt of mafic- ultramafic rocks whose amplitude is comparable with that responsible for the Virorco-Las Aguilas gravimetric anomaly.

Current Sierra Nevada-North America motion from very long baseline interferometry: Implications for the kinematics of the western United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Argus, D.F.; Gordon, R.G.

1991-11-01

The authors use geodetic measurements from very long baseline interferometry to estimate the motion of the Sierra Nevadan microplate. The motion of the Sierra Nevadan microplate relative to the North American plate is described by a right-handed rotation of 0.61{degree}/m.y. about lat 32{degree}N, long 128{degree}W. This Euler pole predicts a significant counterclockwise rotation about a local vertical axis. It further predicts a velocity of the eastern edge of the Sierra Nevada relative to stable North America of 11 {plus minus}1 mm/yr toward N36{degree} {plus minus}3{degree}W, which accounts for about one-fourth of the velocity between the Pacific and North American platesmore » and is {approximately}25{degree} clockwise of many prior estimates. The velocity nearly parallels the boundary between the Sierra Nevada and the Great Basin, which implies that current motion within the Great Basin results in a rotational, noncoaxial deformation. The authors use this velocity to estimate how motion is distributed across the broad deforming zone taking up Pacific-North America plate motion. They find that the vector sum of strike slip along the San Andreas fault and motion of the Sierra Nevada relative to stable North America (taken up by deformation within the Great Basin) differs little from the Pacific-north America plate velocity. The difference can be described at 36{degree}N along the San Andreas fault by a vector of 6 mm/yr directed toward N20{degree}W. This vector resolves into components of 5 mm/yr parallel to the fault and 2 mm/yr perpendicular to the fault with 95% confidence intervals of 0 to 10 mm/yr and {minus}1 to +5 mm/yr, respectively. The authors conclude that motion previously inferred to be taken up by deformation other than strike slip along the San Andreas fault or deformation within the Great Basin is much smaller than previously thought.« less

Summer evapotranspiration trends as related to time following logging of high elevation forest stands in Sierra Nevada

Treesearch

Robert R. Ziemer

1963-01-01

Abstract - The quantity of summer soil moisture loss from logged forest openings was related to the length of time since the creation of the opening in a study made in the subalpine forest zone of the Sierra Nevada west-side near the Central Sierra Snow Laboratory, California, within the elevational range of 6,000 to 7,000 feet. Soil moisture depletion was measured in...

West Coast, United States and Mexico

NASA Image and Video Library

1990-04-29

This view shows the west coast of the United States and Mexico (32.5N, 118.0W) and gives an indication of the range of view from orbital altitude. The visual range of this particular scene is from Skammon's Lagoon on Baja to the northern tip of California's Central Valley and Sierra Nevada, a range of over 15 degrees of latitude. Coastal fog drapes over southern California and northern Baja California. White Sands, New Mexico is at far right center.

Ebola Holding Units at government hospitals in Sierra Leone: evidence for a flexible and effective model for safe isolation, early treatment initiation, hospital safety and health system functioning

PubMed Central

Johnson, Oliver; Youkee, Daniel; Brown, Colin S; Lado, Marta; Wurie, Alie; Bash-Taqi, Donald; Hall, Andy; Hanciles, Eva; Kamara, Isata; Kamara, Cecilia; Kamboz, Amardeep; Seedat, Ahmed; Thomas, Suzanne; Kamara, T B; Leather, Andrew J M; Kargbo, Brima

2016-01-01

The 2014-2015 West African outbreak of Ebola Virus Disease (EVD) claimed the lives of more than 11,000 people and infected over 27,000 across seven countries. Traditional approaches to containing EVD proved inadequate and new approaches for controlling the outbreak were required. The Ministry of Health & Sanitation and King’s Sierra Leone Partnership developed a model for Ebola Holding Units (EHUs) at Government Hospitals in the capital city Freetown. The EHUs isolated screened or referred suspect patients, provided initial clinical care, undertook laboratory testing to confirm EVD status, referred onward positive cases to an Ebola Treatment Centre or negative cases to the general wards, and safely stored corpses pending collection by burial teams. Between 29th May 2014 and 19th January 2015, our five units had isolated approximately 37% (1159) of the 3097 confirmed cases within Western Urban and Rural district. Nosocomial transmission of EVD within the units appears lower than previously documented at other facilities and staff infection rates were also low. We found that EHUs are a flexible and effective model of rapid diagnosis, safe isolation and early initial treatment. We also demonstrated that it is possible for international partners and government facilities to collaborate closely during a humanitarian crisis. PMID:28588922

76 FR 53663 - Sierra County Resource Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-29

... complete project review. The committee is authorized under the Secure Rural Schools and Community Self... back-up meeting if the vote was not completed on September 12.) The agenda may be viewed at https://fsplaces.fs.fed.us/fsfiles/unit/wo/secure_rural_schools.nsf . Anyone who would like to bring related...

Nevada | Midmarket Solar Policies in the United States | Solar Research |

Science.gov Websites

the retail rate. RECs: Customer retain the ownership of renewable energy certificates (RECs). Meter Interconnection standards were adopted by PUCN in 2003 for customer-generators of Nevada Power and Sierra Pacific Utilities Commission of Nevada Customer-generators who do not avail renewable energy rebates from other

Demography of the California spotted owl in the Sierra National Forest and Sequoia/Kings Canyon National Parks

Treesearch

George N. Steger; Thomas E. Munton; Kenneth D. Johnson; Gary P. Eberlein

2002-01-01

Nine years (1990–1998) of demographic data on California spotted owls (Strix occidentalis occidentalis) in two study areas on the western slopes of the Sierra Nevada—one in the Sierra National Forest (SNF), the other in Sequoia/Kings Canyon National Parks (SNP)—are summarized. Numbers of territorial owls fluctuated from 85 to 50 in SNF and 80 to 58...

Magnetic susceptibility and relation to initial 87Sr/86Sr for granitoids of the central Sierra Nevada, California

USGS Publications Warehouse

Bateman, P.C.; Dodge, F.C.W.; Kistler, R.W.

1991-01-01

Measurement of the magnetic susceptibility of more than 6000 samples of granitic rock from the Mariposa 1?? by 2?? quadrangle, which crosses the central part of the Sierra Nevada batholith between 37?? and 38??N latitude, shows that magnetic susceptibility values are above 10-2 SI units in the east and central parts of the batholith and drop abruptly to less than 10-3 SI units in the western foothills. In a narrow transitional zone, intermediate values (10-3 to 10-2) prevail. Magnetic susceptibility appears to decrease slightly westward within the zones of both high and low values. Magnetic susceptibility in plutonic rocks is chiefly a function of the abundance of magnetite, which depends, in turn, on the total iron content of the rocks and their oxidation ratio. Correlations of magnetic susceptibility with initial 87Sr/86Sr suggest that oxidation ratios have been inherited from the source regions for the magmas from which the rocks crystallized. Reduction of Fe3+ to Fe2+ by organic carbon or other reducing substances may also have affected magnetic susceptibility. -from Authors

Using Topography to Meet Wildlife and Fuels Treatment Objectives in Fire-Suppressed Landscapes

PubMed Central

Viers, Joshua H.; Quinn, James F.; North, Malcolm

2010-01-01

Past forest management practices, fire suppression, and climate change are increasing the need to actively manage California Sierra Nevada forests for multiple environmental amenities. Here we present a relatively low-cost, repeatable method for spatially parsing the landscape to help the U.S. Forest Service manage for different forest and fuel conditions to meet multiple goals relating to sensitive species, fuels reduction, forest products, water, carbon storage, and ecosystem restoration. Using the Kings River area of the Sierra Nevada as a case study, we create areas of topographically-based units, Landscape Management Units (LMUs) using a three by three matrix (canyon, mid-slope, ridge-top and northerly, southerly, and neutral aspects). We describe their size, elevation, slope, aspect, and their difference in inherent wetness and solar radiation. We assess the predictive value and field applicability of LMUs by using existing data on stand conditions and two sensitive wildlife species. Stand conditions varied significantly between LMUs, with canyons consistently having the greatest stem and snag densities. Pacific fisher (Martes pennanti) activity points (from radio telemetry) and California spotted owl (Strix occidentalis occidentalis) nests, roosts, and sightings were both significantly different from uniform, with a disproportionate number of observations in canyons, and fewer than expected on ridge-tops. Given the distinct characteristics of the LMUs, these units provide a relatively simple but ecologically meaningful template for managers to spatially allocate forest treatments, thereby meeting multiple National Forest objectives. These LMUs provide a framework that can potentially be applied to other fire-dependent western forests with steep topographic relief. PMID:20872142

Land-Cover Trends of the Sierra Nevada Ecoregion, 1973-2000

USGS Publications Warehouse

Raumann, Christian G.; Soulard, Christopher E.

2007-01-01

The U.S. Geological Survey has developed and is implementing the Land Cover Trends project to estimate and describe the temporal and spatial distribution and variability of contemporary land-use and land-cover change in the United States. As part of the Land Cover Trends project, the purpose of this study was to assess land-use/land-cover change in the Sierra Nevada ecoregion for the period 1973 to 2000 using a probability sampling technique and satellite imagery. We randomly selected 36 100-km2 sample blocks to derive thematic images of land-use/land-cover for five dates of Landsat imagery (1973, 1980, 1986, 1992, 2000). We visually interpreted as many as 11 land-use/land-cover classes using a 60-meter minimum mapping unit from the five dates of imagery yielding four periods for analysis. Change-detection results from post-classification comparison of our mapped data showed that landscape disturbance from fire was the dominant change from 1973-2000. The second most-common change was forest disturbance resulting from harvest of timber resources by way of clear-cutting. The rates of forest regeneration from temporary fire and harvest disturbances coincided with the rates of disturbance from the previous period. Relatively minor landscape changes were caused by new development and reservoir drawdown. Multiple linear regression analysis suggests that land ownership and the proportion of forest and developed cover types were significant determinants of the likelihood of direct human-induced change occurring in sampling units. Driving forces of change include land ownership, land management such as fire suppression policy, and demand for natural resources.

Petroleum Systems and Assessment of Undiscovered Oil and Gas in the Raton Basin - Sierra Grande Uplift Province, Colorado and New Mexico - USGS Province 41

USGS Publications Warehouse

Higley, Debra K.

2007-01-01

Introduction The purpose of the U.S. Geological Survey's (USGS) National Oil and Gas Assessment is to develop geologically based hypotheses regarding the potential for additions to oil and gas reserves in priority areas of the United States. The USGS recently completed an assessment of undiscovered oil and gas resources of the Raton Basin-Sierra Grande Uplift Province of southeastern Colorado and northeastern New Mexico (USGS Province 41). The Cretaceous Vermejo Formation and Cretaceous-Tertiary Raton Formation have production and undiscovered resources of coalbed methane. Other formations in the province exhibit potential for gas resources and limited production. This assessment is based on geologic principles and uses the total petroleum system concept. The geologic elements of a total petroleum system include hydrocarbon source rocks (source rock maturation, hydrocarbon generation and migration), reservoir rocks (sequence stratigraphy and petrophysical properties), and hydrocarbon traps (trap formation and timing). The USGS used this geologic framework to define two total petroleum systems and five assessment units. All five assessment units were quantitatively assessed for undiscovered gas resources. Oil resources were not assessed because of the limited potential due to levels of thermal maturity of petroleum source rocks.

Tectonic, volcanic, and climatic geomorphology study of the Sierras Pampeanas Andes, northwestern Argentina

NASA Technical Reports Server (NTRS)

Bloom, A. L.; Strecker, M. R.; Fielding, E. J.

1984-01-01

A proposed analysis of Shuttle Imaging Radar-B (SIR-B) data extends current research in the Sierras Pampeanas and the Puna of northwestern Argentina to the determination - by the digital analysis of mountain-front sinuousity - of the relative age and amount of fault movement along mountain fronts of the late-Cenozoic Sierras Pampeanas basement blocks; the determination of the age and history of the boundary across the Andes at about 27 S latitude between continuing volcanism to the north and inactive volcanism to the south; and the determination of the age and extent of Pleistocene glaciation in the High Sierras, as well as the comparative importance of climatic change and tectonic movements in shaping the landscape. The integration of these studies into other ongoing geology projects contributes to the understanding of landform development in this active tectonic environment and helps distinguish between climatic and tectonic effects on landforms.

Resilience Through Disturbance: Effects of Wildfire on Vegetation and Water Balance in the Sierra Nevadas

NASA Astrophysics Data System (ADS)

Boisrame, G. F. S.; Thompson, S. E.; Stephens, S.; Collins, B.; Tague, N.

2015-12-01

A century of fire suppression in the Western United States has drastically altered the historically fire-adapated ecology in California's Sierra Nevada Mountains. Fire suppression is understood to have increased the forest cover, as well as the stem density, canopy cover and water demand of montane forests, reducing resilience of the forests to drought, and increasing the risk of catastrophic fire by drying the landscape and increasing fuel loads. The potential to reverse these trends by re-introducing fire into the Sierra Nevada is highly promising, but the likely effects on vegetation structure and water balance are poorly quantified. The Illilouette Creek Basin in Yosemite National Park represents a unique experiment in the Sierra Nevada, in which managers have moved from fire suppression to allowing a near-natural fire regime to prevail since 1972. Changes in vegetation structure in the Illilouette since the restoration of natural burning provides a unique opportunity to examine how frequent, mixed severity fires can reshape the Sierra Nevada landscape. We characterize these changes from 1969 to the present using a combination of Landsat products and high-resolution aerial imagery. We describe how the landscape structure has changed in terms of vegetation composition and its spatial organization, and explore the drivers of different post-fire vegetation type transitions (e.g. forest to shrubland vs. forest to meadow). By upscaling field data using vegetation maps and Landsat wetness indices, we explore how these vegetation transitions have impacted the water balance of the Illilouette Creek Basin, potentially increasing its resilience in the face of drought, climate change, and catastrophic fire. In a region that is adapted to frequent disturbance from fire, this work helps us understand how allowing such natural disturbances to take place can increase the sustainability of diverse landscapes in the long term.

Sierra/Solid Mechanics 4.48 User's Guide.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Merewether, Mark Thomas; Crane, Nathan K; de Frias, Gabriel Jose

Sierra/SolidMechanics (Sierra/SM) is a Lagrangian, three-dimensional code for finite element analysis of solids and structures. It provides capabilities for explicit dynamic, implicit quasistatic and dynamic analyses. The explicit dynamics capabilities allow for the efficient and robust solution of models with extensive contact subjected to large, suddenly applied loads. For implicit problems, Sierra/SM uses a multi-level iterative solver, which enables it to effectively solve problems with large deformations, nonlinear material behavior, and contact. Sierra/SM has a versatile library of continuum and structural elements, and a large library of material models. The code is written for parallel computing environments enabling scalable solutionsmore » of extremely large problems for both implicit and explicit analyses. It is built on the SIERRA Framework, which facilitates coupling with other SIERRA mechanics codes. This document describes the functionality and input syntax for Sierra/SM.« less

Support services for survivors of ebola virus disease - Sierra Leone, 2014.

PubMed

Lee-Kwan, Seung Hee; DeLuca, Nickolas; Adams, Monica; Dalling, Matthew; Drevlow, Elizabeth; Gassama, Gladys; Davies, Tina

2014-12-19

As of December 6, 2014, Sierra Leone reported 6,317 laboratory-confirmed cases of Ebola virus disease (Ebola), the highest number of reported cases in the current West Africa epidemic. The Sierra Leone Ministry of Health and Sanitation reported that as of December 6, 2014, there were 1,181 persons who had survived and were discharged. Survivors from previous Ebola outbreaks have reported major barriers to resuming normal lives after release from treatment, such as emotional distress, health issues, loss of possessions, and difficulty regaining their livelihoods. In August 2014, a knowledge, attitude, and practice survey regarding the Ebola outbreak in Sierra Leone, administered by a consortium of partners that included the Ministry of Health and Sanitation, UNICEF, CDC, and a local nongovernmental organization, Focus 1000, found that 96% of the general population respondents reported some discriminatory attitude towards persons with suspected or known Ebola. Access to increased psychosocial support, provision of goods, and family and community reunification programs might reduce these barriers. Survivors also have unique potential to contribute to the Ebola response, particularly because survivors might have some immunity to the same virus strain. In previous outbreaks, survivors served as burial team members, contact tracers, and community educators promoting messages that seeking treatment improves the chances for survival and that persons who survived Ebola can help their communities. As caregivers in Ebola treatment units, survivors have encouraged patients to stay hydrated and eat and inspired them to believe that they, too, can survive. Survivors regaining livelihood through participation in the response might offset the stigma associated with Ebola.

Comment on "Methodology and results of calculating Central California surface temperature trends: evidence of human-induced climate change?" by Christy et al. (2006)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonfils, C; Duffy, P; Lobell, D

2006-03-28

Understanding the causes of observed regional temperature trends is essential to projecting the human influences on climate, and the societal impacts of these influences. In their recent study, Christy et al. (2006, hereinafter CRNG06) hypothesized that the presence of irrigated soils is responsible for rapid warming of summer nights occurring in California's Central Valley over the last century (1910-2003), an assumption that rules out any significant effect due to increased greenhouse gases, urbanization, or other factors in this region. We question this interpretation, which is based on an apparent contrast in summer nighttime temperature trends between the San Joaquin Valleymore » ({approx} +0.3 {+-} 0.1 C/decade) and the adjacent western slopes of the Sierra Nevada (-0.25 {+-} 0.15 C/decade), as well as the amplitude, sign and uncertainty of the Sierra nighttime temperature trend itself. We, however, do not dispute the finding of other Sierra and Valley trends. Regarding the veracity of the apparent Sierra nighttime temperature trend, CRNG06 generated the Valley and Sierra time-series using a meticulous procedure that eliminates discontinuities and isolates homogeneous segments in temperature records from 41 weather stations. This procedure yields an apparent cooling of about -0.25 {+-} 0.15 C/decade in the Sierra region. However, because removal of one of the 137 Sierra segments, from the most elevated site (Huntington Lake, 2140m), causes an increase in nighttime temperature trend as large as the trend itself (of +0.25 C/decade, CH06), and leads to a zero trend, the apparent cooling of summer nights in the Sierra regions seems, in fact, largely uncertain.« less

Current investigations of fungal ectomycorrhizal communities in the Sierra Nevada Forest

Treesearch

Thomas D. Bruns; Annette M. Kretzer; Thomas R. Horton; Eric A-D. Stendell; Martin I. Bidartondo; Timothy M. Szaro

2002-01-01

Progress on two main studies on fungal ectomycorrhizal communities in the Sierra National Forest is discussed. One study examined the short-term effects of ground fire on the ectomycorrhizal community and the other examined the ectomycorrhizal associates of snow plant (Sarcodes sanguinea). In the ground-fire study we found that a large initial...

Interaction of an Introduced Predator with Future Effects of Climate Change in the Recruitment Dynamics of the Imperiled Sierra Nevada Yellow-legged Frog (Rana sierrae)

Treesearch

I Lacan; Kathleen R. Matthews; K.V. Feldman

2008-01-01

Between-year variation in snowpack (from 20 to 200% of average) and summer rainfall cause large fluctuations in volume of small lakes in the higher elevation (> 3000 m) Sierra Nevada, which are important habitat for the imperiled Sierra Nevada Yellow-legged Frog, Rana sierrae. Climate change (global warming) is predicted to increase these...

The effects of charcoal and pile burns on C and N Dynamics in Eastern Sierra Nevadan forested soils

USDA-ARS?s Scientific Manuscript database

Over a century of fire prevention and suppression in the western United States has led to overstocked and diseased forests with increased fuel loading and vertical continuity of fuels, thus increasing the risk of severe and stand-replacing wildfire. Mechanical thinning followed by pile burning is a ...

Conservation of avian diversity in the Sierra Nevada: Moving beyond a single-species management focus

Treesearch

Angela M. White; Elise F. Zipkin; Patricia N. Manley; Matthew D. Schlesinger

2013-01-01

Background: As a result of past practices, many of the dry coniferous forests of the western United States contain dense, even-aged stands with uncharacteristically high levels of litter and downed woody debris. These changes to the forest have received considerable attention as they elevate concerns regarding the outcome of wildland fire...

Recreation in whitebark pine ecosystems: Demand, problems, and management strategies

Treesearch

David N. Cole

1990-01-01

Whitebark pine ecosystems are an important element of many of the most spectacular high-elevation landscapes in the western United States. They occupy upper subalpine and timberline zones in the prime recreation lands of the Cascades, the Sierra Nevada, and the Northern Rocky Mountains. This paper explores the nature of the recreational opportunities that the whitebark...

Fuel treatment effects on modeled landscape level fire behavior in the northern Sierra Nevada

Treesearch

J.J. Moghaddas; B.M. Collins; K. Menning; E.E.Y. Moghaddas; S.L. Stephens

2010-01-01

Across the western United States, decades of fire exclusion combined with past management history have contributed to the current condition of extensive areas of high-density, shade-tolerant coniferous stands that are increasingly prone to high-severity fires. Here, we report the modeled effects of constructed defensible fuel profile zones and group selection...

Unit area control--its development and application

Treesearch

William E. Hallin

1954-01-01

Thirty years of research in the ponderosa pine and mixed conifer forests of the Sierra of California by Dunning and his associates have shown that previous methods of silviculture were not providing adequate restocking of pine. Analysis of records indicated a new approach was necessary. From this work, new procedures that gave most promise of success were formulated...

75 FR 17452 - Sunshine Federal Register Notice

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-06

... of April 26, 2010--Tentative Thursday, April 29, 2010 9:30 a.m. Briefing on the Fuel Cycle Oversight... Authority (Watts Bar Nuclear Plant, Unit 2), Notice of Appeal, and Brief on Appeal of LBP-09-26 by Sierra..., Employee/Labor Relations and Work Life Branch, at 301-492-2230, TDD: 301-415-2100, or by e-mail at angela...

Impact of climate change on projected runoff from mountain snowpack of the King’s Rivershed in California

USDA-ARS?s Scientific Manuscript database

The Central Valley of California, like most dryland agricultural areas in the Southwest United States, relies heavily on winter snowpack for water resources. Projections of future climate in the Sierra Mountains of California calls for a warmer climate regime that will impact the snowpack in the Sie...

Biogeography and diversity of pines in the Madrean Archipelago

Treesearch

George M. Ferguson; Aaron D. Flesch; Thomas R. Van Devender

2013-01-01

Pines are important dominants in pine-oak, pine and mixed-conifer forests across the Colorado Plateau, southern Rocky Mountains, Sierra Madre Occidental, and in the intervening Sky Islands of the United States-Mexico borderlands. All 17 native species of pines in the Sky Islands region or their adjacent mountain mainlands reach the northern or southern margins of their...

Cytogeography of Larrea tridentata at the Chihuahuan-Sonoran Desert ecotone

Treesearch

Robert G. Laport; Robert L. Minckley

2013-01-01

The long separation of the Chihuahuan and Sonoran Deserts is reflected in the high species richness and endemism of their floras. Although many endemic species from both deserts reach their distributional limits where the Sierra Madre Occidental massif fragments into smaller mountain complexes in northern Mexico and adjoining areas of the United States, indicator...

Status of black-tailed prairie dog (Cynomys ludovicianus) in Sonora, Mexico

Treesearch

Reyna A. Castillo-Gamez; Rafael Arenas-Wong; Luis Castillo-Quijada; Verónica Coronado-Peraza; Abigail Enríquez-Munguia; Mirna Federico-Ortega; Alejandra García-Urrutia; Alba Lozano-Gámez; Romeo Méndez-Estrella; Laura Ochoa-Figueroa; J. R. Romo-León; Guy Kruse-Llergo; Iván Parra-Salazar

2005-01-01

Prairie dog is a keystone species throughout the habitat where it occurs, but its populations have declined about 98% in the last century. This species has been considered of international importance for the United States of America, Canada, and Mexico. Only two populations are recorded for Mexico, and the westernmost (isolated by Sierra Madre...

Utilization of respondent-driven sampling among a population of child workers in the diamond-mining sector of Sierra Leone.

PubMed

Bjørkhaug, I; Hatløy, A

2009-01-01

This article describes the implementation of respondent driven sampling (RDS) in a study conducted in Kono District, Sierra Leone. RDS was used to identify children, under the age of 18 years old, working in the diamond sector of Sierra Leone. This includes children working directly as diamond miners as well as children working in the informal sector connected to the diamond field. The article seeks to postulate that RDS is a suitable method for a rapid approach to a population that is unidentified in size and demonstrate how RDS can reach a study population within a limited period.

SIERRA - A 3-D device simulator for reliability modeling

NASA Astrophysics Data System (ADS)

Chern, Jue-Hsien; Arledge, Lawrence A., Jr.; Yang, Ping; Maeda, John T.

1989-05-01

SIERRA is a three-dimensional general-purpose semiconductor-device simulation program which serves as a foundation for investigating integrated-circuit (IC) device and reliability issues. This program solves the Poisson and continuity equations in silicon under dc, transient, and small-signal conditions. Executing on a vector/parallel minisupercomputer, SIERRA utilizes a matrix solver which uses an incomplete LU (ILU) preconditioned conjugate gradient square (CGS, BCG) method. The ILU-CGS method provides a good compromise between memory size and convergence rate. The authors have observed a 5x to 7x speedup over standard direct methods in simulations of transient problems containing highly coupled Poisson and continuity equations such as those found in reliability-oriented simulations. The application of SIERRA to parasitic CMOS latchup and dynamic random-access memory single-event-upset studies is described.

The Children's War: Towards Peace in Sierra Leone. A Field Report Assessing the Protection and Assistance Needs of Sierra Leonean Children and Adolescents.

ERIC Educational Resources Information Center

Sommers, Marc

Based on a 3-week field visit to Sierra Leone and Guinea, this report investigates why children (ages 0-17) have become key figures in Sierra Leone's civil war, and explores the problems that war has caused them. The report describes significant new effects of violence on three groups of Sierra Leonean children, very few of whom have received any…

Comparison of preliminary herpetofaunas of the Sierras la Madera (Oposura) and Bacadehuachi with the mainland Sierra Madre Occidental in Sonora, Mexico

Treesearch

Thomas R. Van Devender; Erik F. Enderson; Dale S. Turner; Roberto A. Villa; Stephen F. Hale; George M. Ferguson; Charles Hedgcock

2013-01-01

Amphibians and reptiles were observed in the Sierra La Madera (59 species), an isolated Sky Island mountain range, and the Sierra Bacadéhuachi (30 species), the westernmost mountain range in the Sierra Madre Occidental (SMO) range in east-central Sonora. These preliminary herpetofaunas were compared with the herpetofauna of the Yécora area in eastern Sonora in the main...

Ground-Water Geology and Hydrology of the Kern River Alluvial-Fan Area, California

USGS Publications Warehouse

Dale, R.H.; French, James J.; Gordon, G.V.

1966-01-01

The Kern River alluvial fan is the southernmost major alluvial fan built by the streams which drain the west side of the Sierra Nevada. The climate is semiarid with rainfall near 5 inches per year. Agricultural development within the area uses over half the 700,000 acre-feet per year flow of the Kern River, plus a considerable amount drawn from the ground-water reservoir particularly during periods of low flow. The area overlies a deep structural trough between crystalline rocks of the Sierra Nevada and the marine rocks of Tertiary age of the Coast Ranges. The top horizon of the marine rocks that lap on the Sierra Nevada block underlies the report area at an average depth of 2,000 feet. The overlying continental deposits that form the groundwater reservoir consist of alluvial-fan and lacustrine deposits. The continental deposits are subdivided into three lithologic units on the basis of grain size and sorting. The gravel and clay unit consists of older alluvial-fan material, of both Sierra Nevada and Coast Range provenance, that shows extremely poor sorting with some diagenetic decomposition through chemical weathering. The fine sand to clay unit consists principally of fine sand, silt, and clay deposited in a lacustrine environment, although some of the unit is of alluvial-fan origin derived from poorly consolidated marine shale of the Coast Ranges. Within the fine sand to clay unit three distinct clays, which affect ground-water conditions, can be recognized. The gravel to medium sand unit consists of unweathered alluvial-fan material that shows much better sorting than the gravel and clay unit. In the eastern part of the area the basal part of this unit is a gravel lentil that can be traced in the subsurface more than 250 square miles. The overlying deposits consist principally of medium sand. In the western part of the area the unit is a heterogeneous gravel and sand unit. Permeability in Meinzer units of the gravel and clay unit ranges between 10 and 100 with specific yield about 5 percent. For the fine sand to clay unit the permeability ranges between 0.0001 and 100 with about 10 percent specific yield. The gravel to medium sand unit has permeabilities between 100 and 10,000, and specific yield is about 15 percent. For the period 1955-59 the annual gross surface-water supply was estimated at 421,000 acre-feet and pumpage was 664,000 acre-feet, giving a rounded total supply of 1,100,000 acre-feet. Annual consumptive use was estimated at 750,000 acre-feet and annual infiltration at 350,000 acre-feet. The approximate 300,000 acre-feet difference between 664,000 acre-feet pumped and 350,000 acre-feet infiltrated has caused an annual decline in water levels of up to 7 feet. Ground water occurs under both unconfined and confined conditions within the report area. In general, the gravel to medium sand unit contains unconfined water, and the other two units contain confined water. Pumping is less intense in the Kern River fan area than in the adjoining areas to the north or south. This fact, plus infiltration from the Kern River, results in ground-water movement being principally out of the area. There is a ground-water divide that approximately underlies the Kern River. South of the river the flow spreads out semicircularly from the river, and north of the river the flow is linear to the northwest. Based on chemical quality the ground water has been divided areally into (1) east side, (2) west side, and (3) axial water. With the exception of two areas of comparable size northwest of Bakersfield and a much smaller area southeast of that city where ground water is somewhat saline, east-side ground water is generally of the calcium bicarbonate and calcium sodium bicarbonate type of low to medium salinity. The chemical character of east-side ground water is necessarily related to that of Kern River water, the principal source of recharge, and water of intermittent streams which drain the dissected upland

Species Composition and Habitat Associations of Benthic Algal Assemblages in Headwater Streams of the Sierra Nevada, California

Treesearch

Larry R. Brown; Jason T. May; Carolyn T. Hunsaker

2008-01-01

Despite their trophic importance and potential importance as bioindicators of stream condition, benthic algae have not been well studied in California. In particular there are few studies from small streams in the Sierra Nevada. The objective of this study was to determine the standing crop of chlorophyll-a and benthic algal species assemblages...

Airborne LiDAR analysis and geochronology of faulted glacial moraines in the Tahoe-Sierra frontal fault zone reveal substantial seismic hazards in the Lake Tahoe region, California-Nevada USA

USGS Publications Warehouse

Howle, James F.; Bawden, Gerald W.; Schweickert, Richard A.; Finkel, Robert C.; Hunter, Lewis E.; Rose, Ronn S.; von Twistern, Brent

2012-01-01

We integrated high-resolution bare-earth airborne light detection and ranging (LiDAR) imagery with field observations and modern geochronology to characterize the Tahoe-Sierra frontal fault zone, which forms the neotectonic boundary between the Sierra Nevada and the Basin and Range Province west of Lake Tahoe. The LiDAR imagery clearly delineates active normal faults that have displaced late Pleistocene glacial moraines and Holocene alluvium along 30 km of linear, right-stepping range front of the Tahoe-Sierra frontal fault zone. Herein, we illustrate and describe the tectonic geomorphology of faulted lateral moraines. We have developed new, three-dimensional modeling techniques that utilize the high-resolution LiDAR data to determine tectonic displacements of moraine crests and alluvium. The statistically robust displacement models combined with new ages of the displaced Tioga (20.8 ± 1.4 ka) and Tahoe (69.2 ± 4.8 ka; 73.2 ± 8.7 ka) moraines are used to estimate the minimum vertical separation rate at 17 sites along the Tahoe-Sierra frontal fault zone. Near the northern end of the study area, the minimum vertical separation rate is 1.5 ± 0.4 mm/yr, which represents a two- to threefold increase in estimates of seismic moment for the Lake Tahoe basin. From this study, we conclude that potential earthquake moment magnitudes (Mw) range from 6.3 ± 0.25 to 6.9 ± 0.25. A close spatial association of landslides and active faults suggests that landslides have been seismically triggered. Our study underscores that the Tahoe-Sierra frontal fault zone poses substantial seismic and landslide hazards.

Sierra Structural Dynamics Theory Manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reese, Garth M.

Sierra/SD provides a massively parallel implementation of structural dynamics finite element analysis, required for high fidelity, validated models used in modal, vibration, static and shock analysis of structural systems. This manual describes the theory behind many of the constructs in Sierra/SD. For a more detailed description of how to use Sierra/SD , we refer the reader to Sierra/SD, User's Notes . Many of the constructs in Sierra/SD are pulled directly from published material. Where possible, these materials are referenced herein. However, certain functions in Sierra/SD are specific to our implementation. We try to be far more complete in those areas.more » The theory manual was developed from several sources including general notes, a programmer notes manual, the user's notes and of course the material in the open literature. This page intentionally left blank.« less

Soil acidity, temperature, and water relationships of four clovers in Sierra Nevada meadows

Treesearch

Raymond D. Ratliff; Ethelynda E. Harding

1993-01-01

Sites in meadows of the Sierra Nevada near Fresno, California, were studied to learn whether Bolander's (Trifolium holanderi Gray.), longstalked (T. longipes Nutt.), carpet (T. monanthum Gray.), and mountain (T. wormskioldii Lehm.) clovers occurred under the same soil acidity, temperature...

Response of Sierra Nevada vegetation and fire regimes to past climate changes

Treesearch

R. Scott Anderson

2004-01-01

The study of changing vegetation patterns within forested communities of the Sierra Nevada has had a long history, initiated by the great naturalist John Muir. More recently, paleoecologists, who study ecosystems of the past, have analyzed fossil plant remains recovered from lake and meadow sediments to understand the regional biogeography and disturbance history of...

What Is Shakespeare Doing in My Hut?: A-Level Literature and the Sierra Leonean Student.

ERIC Educational Resources Information Center

Wright, Handel K.

A study brought together literature appreciation, schema theory, and cross-cultural studies to explore the relationship between the backgrounds of students in one sixth-form literature class in Sierra Leone and the contexts of the plays described in the drama section of the "A" level literature syllabus of the West African Examinations…

AmeriFlux US-CZ4 Sierra Critical Zone, Sierra Transect, Subalpine Forest, Shorthair

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goulden, Michael

This is the AmeriFlux version of the carbon flux data for the site US-CZ4 Sierra Critical Zone, Sierra Transect, Subalpine Forest, Shorthair. Site Description - Half hourly data are available at https://www.ess.uci.edu/~california/. This site is one of four Southern Sierra Critical Zone Observatory flux towers operated along an elevation gradient (sites are USCZ1, USCZ2, USCZ3 and USCZ4). This site is a lodgepole pine subalpine woodland with no recent disturbance.

Paleozoic-involving thrust array in the central Sierras Interiores (South Pyrenean Zone, Central Pyrenees): regional implications

NASA Astrophysics Data System (ADS)

Rodriguez, L.; Cuevas, J.; Tubía, J. M.

2012-04-01

This work deals with the structural evolution of the Sierras Interiores between the Tena and Aragon valleys. The Sierras Interiores is a WNW-trending mountain range that bounds the South Pyrenean Zone to the north and that is characterized by a thrust-fold system with a strong lithological control that places preferably decollements in Triassic evaporites. In the studied area of the Sierras Interiores Cenomanian limestones cover discordantly the Paleozoic rocks of the Axial Zone because there is a stratigraphic lacuna developed from Triassic to Late Cretaceous times. A simple lithostratigraphy of the study area is made up of Late Cenomanian to Early Campanian limestones with grey colour and massive aspect in landscape (170 m, Lower calcareous section), Campanian to Maastrichtian brown coloured sandstones (400-600 m, Marboré sandstones) and, finally, Paleocene light-coloured massive limestones (130-230 m), that often generate the higher topographic levels of the Sierras Interiores due to their greater resistance to erosion. Above the sedimentary sequence of the Sierras Interiores, the Jaca Basin flysch succession crops out discordantly. Based on a detailed mapping of the studied area of the Sierras Interiores, together with well and structural data of the Jaca Basin (Lanaja, 1987; Rodríguez and Cuevas, 2008) we have constructed a 12 km long NS cross section, approximately parallel to the movement direction deduced for this region (Rodríguez et al., 2011). The main structure is a thrust array made up of at least four Paleozoic-involving thrusts (the deeper thrust system) of similar thickness in a probably piggyback sequence, some of which are blind thrusts that generate fold-propagation-folds in upper levels. The higher thrust of the thrust array crops out duplicating the lower calcareous section all over the Sierras Interiores. The emplacement of the deeper thrust system generated the tightness of previous structures: south directed piggyback duplexes (the upper thrust system) affecting the Marboré sandstones and the Paleocene limestones, deformed by angular south-vergent folds and their related axial plane foliation. The transect explained above clearly summarizes the alpine evolution of northern part of the Sierras Interiores. Moreover, well data available indicate the presence of two thrust soled in the lower calcareous section covering Triassic evaporites at 5 km depth and 8 km to the south of the Sierras Interiores. Because the Triassic evaporites constitute a main decollement level in the South Pyrenean Zone, the deeper thrust system is associated to the emplacement of the Gavarnie nappe. Lanaja, J.M., 1987, Contribución de la exploración petrolífera al conocimiento de la Geología de España, IGME, Madrid, 465 p. Rodríguez, L., Cuevas, J., 2008. Geogaceta 44, 51-54. Rodríguez, L., Cuevas, J., Tubia, J.M., 2011. Geophysical Research Abstracts 13, 2273.

Sierra/SolidMechanics 4.48 Verification Tests Manual.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plews, Julia A.; Crane, Nathan K; de Frias, Gabriel Jose

2018-03-01

Presented in this document is a small portion of the tests that exist in the Sierra / SolidMechanics (Sierra / SM) verification test suite. Most of these tests are run nightly with the Sierra / SM code suite, and the results of the test are checked versus the correct analytical result. For each of the tests presented in this document, the test setup, a description of the analytic solution, and comparison of the Sierra / SM code results to the analytic solution is provided. Mesh convergence is also checked on a nightly basis for several of these tests. This documentmore » can be used to confirm that a given code capability is verified or referenced as a compilation of example problems. Additional example problems are provided in the Sierra / SM Example Problems Manual. Note, many other verification tests exist in the Sierra / SM test suite, but have not yet been included in this manual.« less

Sierra/SolidMechanics 4.48 Verification Tests Manual.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plews, Julia A.; Crane, Nathan K.; de Frias, Gabriel Jose

Presented in this document is a small portion of the tests that exist in the Sierra / SolidMechanics (Sierra / SM) verification test suite. Most of these tests are run nightly with the Sierra / SM code suite, and the results of the test are checked versus the correct analytical result. For each of the tests presented in this document, the test setup, a description of the analytic solution, and comparison of the Sierra / SM code results to the analytic solution is provided. Mesh convergence is also checked on a nightly basis for several of these tests. This documentmore » can be used to confirm that a given code capability is verified or referenced as a compilation of example problems. Additional example problems are provided in the Sierra / SM Example Problems Manual. Note, many other verification tests exist in the Sierra / SM test suite, but have not yet been included in this manual.« less

Late Paleozoic deformation and exhumation in the Sierras Pampeanas (Argentina): 40Ar/39Ar-feldspar dating constraints

NASA Astrophysics Data System (ADS)

Löbens, Stefan; Oriolo, Sebastián; Benowitz, Jeff; Wemmer, Klaus; Layer, Paul; Siegesmund, Siegfried

2017-09-01

Systematic 40Ar/39Ar feldspar data obtained from the Sierras Pampeanas are presented, filling the gap between available high- (> 300 °C) and low-temperature (< 150 °C) thermochronological data. Results show Silurian-Devonian exhumation related to the late stages of the Famatinian/Ocloyic Orogeny for the Sierra de Pocho and the Sierra de Pie de Palo regions, whereas the Sierras de San Luis and the Sierra de Comechingones regions record exhumation during the Carboniferous. Comparison between new and available data points to a Carboniferous tectonic event in the Sierras Pampeanas, which represents a key period to constrain the early evolution of the proto-Andean margin of Gondwana. This event was probably transtensional and played a major role during the evolution of the Paganzo Basin as well as during the emplacement of alkaline magmatism in the retroarc.

Biophysical controls on soil respiration in the dominant patch types of an old-growth, mixed-conifer forest

Treesearch

Siyan Ma; Jiquan Chen; John R. Butnor; Malcolm North; Eugénie S. Euskirchen; Brian Oakley

2005-01-01

Little is known about biophysical controls on soil respiration in California's Sierra Nevada old-growth, mixed-conifer forests. Using portable and automated soil respiration sampling units, we measured soil respiration rate (SRR) in three dominant patch types: closed canopy (CC), ceanothus-dominated patches (CECO), and open canopy (OC). SRR varied significantly...

Great Basin cold desert shrublands and the Desert Experimental Range

Treesearch

Stanley G. Kitchen; Stephanie L. Carlson

2008-01-01

The Great Basin is a vast, internally drained region of the Western United States, bounded by the Sierra Nevada and southern Cascade Mountain ranges to the west and the Wasatch Mountains and western rim of the Colorado Plateau to the east. Although less discrete, northern and southern boundaries are generally defined by the drainages of the Columbia and Colorado Rivers...

Characterizing runoff and water yield for headwater catchments in the southern Sierra Nevada

Treesearch

Mohammad Safeeq; Carolyn T. Hunsaker

2016-01-01

In a Mediterranean climate where much of the precipitation falls during winter, snowpacks serve as the primary source of dry season runoff. Increased warming has led to significant changes in hydrology of the western United States. An important question in this context is how to best manage forested catchments for water and other ecosystem services? Answering this...

Characterization of habitat preferences for selected wildlife species in encinal savannas of the Southwest [Poster

Treesearch

Wendy D. Jones; Carlton M. Jones; Peter F. Ffolliott; Gerald J. Gottfried

2005-01-01

The encinal savannas of the sub-mogollon southwestern United States are important for livestock grazing and wildlife habitat. Little data have been collected on the ecology of these Sierra Madrean types of woodland land areas, which makes management difficult. Obtaining information such as habitat preferences for selected wildlife species and livestock can be an...

Restoring surface fire stabilizes forest carbon under extreme fire weather in the Sierra Nevada

Treesearch

Daniel J. Krofcheck; Matthew D. Hurteau; Robert M. Scheller; E. Louise Loudermilk

2017-01-01

Climate change in the western United States has increased the frequency of extreme fire weather events and is projected to increase the area burned by wildfire in the coming decades. This changing fire regime, coupled with increased high-severity fire risk from a legacy of fire exclusion, could destabilize forest carbon (C), decrease net ecosystem exchange (...

The transition from riparian to upland forest plant communities on headwater streams in the southern Sierra Nevada, California, United States

Treesearch

Christopher R. Dolanc; Carolyn T. Hunsaker

2017-01-01

Abstract. Fixed-width buffer zones on rivers and streams are designed to protect the diverse riparian community and its important function in the ecosystem. However, recent data suggest that riparian areas of some western forests have become more fire prone because of restrictions on fuel reduction treatments within buffer zones....

Wildlife survey and monitoring in the Sky Island Region with an emphasis on neotropical felids

Treesearch

Sergio Avila-Villegas; Jessica Lamberton-Moreno

2013-01-01

The Sky Island region of southwestern United States and northwestern Mexico consists of isolated mountain ranges separated by deserts and grasslands. It mixes elements from five major ecosystems: the Rocky Mountains, Sierra Madre Occidental, the Sonoran and Chihuahuan deserts and the Neotropics. Here some Neotropical species reach their northern ranges, such as jaguars...

Sierra Nevada Ecosystem Project

Treesearch

C. I. Millar

1996-01-01

Sierra Nevada Ecosystems. The Sierra Nevada evokes images particular to each individual's experience of the range. These images take on the quality of immutability, and we expect to find the range basically unchanged from one year to the next. The Sierra Nevada, however, including its rocky foundations and the plants and animals that inhabit it, changes...

Density structure of the lithosphere in the southwestern United States and its tectonic significance

USGS Publications Warehouse

Kaban, M.K.; Mooney, W.D.

2001-01-01

We calculate a density model of the lithosphere of the southwestern United States through an integrated analysis of gravity, seismic refraction, drill hole, and geological data. Deviations from the average upper mantle density are as much as ?? 3%. A comparison with tomographic images of seismic velocities indicates that a substantial part (>50%) of these density variations is due to changes in composition rather than temperature. Pronounced mass deficits are found in the upper mantle under the Basin and Range Province and the northern part of the California Coast Ranges and adjacent ocean. The density structure of the northern and central/southern Sierra Nevada is remarkably different. The central/southern part is anomalous and is characterized by a relatively light crust underlain by a higher-density upper mantle that may be associated with a cold, stalled subducted plate. High densities are also determined within the uppermost mantle beneath the central Transverse Ranges and adjoining continental slope. The average density of the crystalline crust under the Great Valley and western Sierra Nevada is estimated to be up to 200 kg m~3 higher than the regional average, consistent with tectonic models for the obduction of oceanic crust and uppermost mantle in this region.

Resting habitat selection by fishers in California

Treesearch

William J. Zielinski; Richard L. Truex; Gregory A. Schmidt; Fredrick V. Schlexer; Kristin N. Schmidt; Reginald H. Barrett

2004-01-01

We studied the resting habitat ecology of fishers (Martes pennanti) in 2 disjunct populations in California, USA: the northwestern coastal mountains (hereafter, Coastal) and the southern Sierra Nevada (hereafter, Sierra). We described resting structures and compared features surrounding resting structures (the resting site) with those at randomly...

Sierra Leone's Former Child Soldiers: A Follow-Up Study of Psychosocial Adjustment and Community Reintegration

ERIC Educational Resources Information Center

Betancourt, Theresa Stichick; Borisova, Ivelina Ivanova; Williams, Timothy Philip; Brennan, Robert T.; Whitfield, Theodore H.; de la Soudiere, Marie; Williamson, John; Gilman, Stephen E.

2010-01-01

This is the first prospective study to investigate psychosocial adjustment in male and female former child soldiers (ages 10-18; n = 156, 12% female). The study began in Sierra Leone in 2002 and was designed to examine both risk and protective factors in psychosocial adjustment. Over the 2-year period of follow-up, youth who had wounded or killed…

Seismic character of the crust and upper mantle beneath the Sierra Nevada

NASA Astrophysics Data System (ADS)

Frassetto, A.; Gilbert, H.; Zandt, G.; Owens, T. J.; Jones, C.

2008-12-01

Recent geophysical studies of the Southern Sierra Nevada suggest that the removal of a gravitationally unstable, eclogitic residue links to recent volcanism and uplift in the Eastern Sierra. The Sierra Nevada EarthScope Project (SNEP) investigates the extent of this process beneath Central and Northern Sierra Nevada. We present receiver functions, which provide estimates of crustal thickness and Vp/Vs and image the response of the crust and upper mantle to lithospheric removal. For completeness this study combines data from the 2005-2007 SNEP broadband experiment, EarthScope's BigFoot Array, regional backbone stations, and earlier PASSCAL deployments. We analyze transects of teleseismic receiver functions generated using a common-conversion-point stacking algorithm. These identify a narrow, "bright" conversion from the Moho at depths of ~25-35 km along the crest of the Eastern Sierra and adjacent Basin and Range northward to the Cascade Arc. Trade-off analysis using the primary conversion and reverberations shows a high Vp/Vs (~1.9) throughout the Eastern Sierra, which may relate to partial melt present in the lower crust. To the west the crust-mantle boundary vanishes beneath the western foothills. However, low frequency receiver functions do image the crust-mantle boundary exceeding 50 km depth along the foothills to the west and south of Yosemite National Park. Unusually deep, intraplate earthquakes (Ryan et al., this session) occur in the center of this region. The frequency dependence of the Moho conversion implies a gradational increase from crust to mantle wavespeeds over a significant depth interval. The transition from a sharp to gradational Moho probably relates to the change from a delaminated granitic crust to crust with an intact, dense, eclogitic residue. The spatial correlation and focal mechanisms of the deep earthquakes suggest that a segment of this still intact residue is currently delaminating.

Insights on Lithospheric Foundering from the Sierra Nevada Earthscope Project (SNEP)

NASA Astrophysics Data System (ADS)

Zandt, G.; Gilbert, H.; Frassetto, A.; Owens, T.; Jones, C.

2004-12-01

Interdisciplinary studies in the southern Sierra Nevada have documented an ongoing removal of the dense residual root from beneath the southern Sierra Nevada batholith. However, many questions remain concerning the timing, spatial extent, mechanism, and consequences of this lithospheric foundering event. The Sierra Nevada Earthscope Project (SNEP) is a scientific experiment designed to investigate these questions with a 2- phase (2 year) seismic deployment of 46 broadband Flex-Array stations embedded in the existing stations of the USArray Transportable Array (TA) in the region. In the 2 phases, approximately 80 sites have been occupied from the northern edge of Kings Canyon north to Honey Lake and from the Central Valley into the Great Basin. In this presentation, we will focus on the most recent common-conversion-point (CCP) stacks of the receiver functions that provide a 3D image of lithospheric layering beneath the central and northern Sierra Nevada. Examining sequential cross-sections reveals distinctive lithospheric "reflectivity" patterns that characterize different tectonic imprints. From phase 1 data, we observed that the westernmost Basin and Range exhibits strong layering with multiple low-velocity zones in the crust and uppermost mantle and a relatively flat and strong Moho varying slowly in depth between 30 and 35 km. In the south this Basin and Range character terminates on the eastern edge of the Sierra Nevada; however, north of Big Pine the Basin and Range character intrudes progressively farther into the range and ends up more than 50 km west of the eastern edge of the range. The lithosphere beneath the southern high Sierra Nevada is characterized by a relatively transparent (homogeneous) crust and sharp Moho that disappears westward beneath the adjacent foothills. The crustal thickness in this area is mostly between 30-35 km with localized welts of thicker crust. The phase 1 observations imply that the removal process appears to be actively affecting the crust northward through at least the central Sierra Nevada. The phase 2 deployment provides coverage to the northern limit of the Sierra Nevada to determine the extent of the affected region and the character of the batholith where root removal may or may not have occurred.

Insights on Lithospheric Foundering from the Sierra Nevada Earthscope Project (SNEP)

NASA Astrophysics Data System (ADS)

Zandt, G.; Gilbert, H.; Frassetto, A.; Owens, T.; Jones, C.

2007-12-01

Interdisciplinary studies in the southern Sierra Nevada have documented an ongoing removal of the dense residual root from beneath the southern Sierra Nevada batholith. However, many questions remain concerning the timing, spatial extent, mechanism, and consequences of this lithospheric foundering event. The Sierra Nevada Earthscope Project (SNEP) is a scientific experiment designed to investigate these questions with a 2- phase (2 year) seismic deployment of 46 broadband Flex-Array stations embedded in the existing stations of the USArray Transportable Array (TA) in the region. In the 2 phases, approximately 80 sites have been occupied from the northern edge of Kings Canyon north to Honey Lake and from the Central Valley into the Great Basin. In this presentation, we will focus on the most recent common-conversion-point (CCP) stacks of the receiver functions that provide a 3D image of lithospheric layering beneath the central and northern Sierra Nevada. Examining sequential cross-sections reveals distinctive lithospheric "reflectivity" patterns that characterize different tectonic imprints. From phase 1 data, we observed that the westernmost Basin and Range exhibits strong layering with multiple low-velocity zones in the crust and uppermost mantle and a relatively flat and strong Moho varying slowly in depth between 30 and 35 km. In the south this Basin and Range character terminates on the eastern edge of the Sierra Nevada; however, north of Big Pine the Basin and Range character intrudes progressively farther into the range and ends up more than 50 km west of the eastern edge of the range. The lithosphere beneath the southern high Sierra Nevada is characterized by a relatively transparent (homogeneous) crust and sharp Moho that disappears westward beneath the adjacent foothills. The crustal thickness in this area is mostly between 30-35 km with localized welts of thicker crust. The phase 1 observations imply that the removal process appears to be actively affecting the crust northward through at least the central Sierra Nevada. The phase 2 deployment provides coverage to the northern limit of the Sierra Nevada to determine the extent of the affected region and the character of the batholith where root removal may or may not have occurred.

Distrubution of the Endocrine Disruptor Nonylphenol and the Effects of Topographical Sheilding in an Eastern Sierra Nevada Mountain Drainage

NASA Astrophysics Data System (ADS)

Lyons, R. A.; Van de Bittner, K.; Morgan Jones, S.

2013-12-01

Nonylphenol is a biodegradation product of nonylphenol polyethoxylates, a pervasive compound used in many industrial processes and notably in pesticides as a surfactant. Nonylphenol has been shown to act as an endocrine disruptor at low concentrations. It causes hermaphrodism, birth defects, and high mortality in fish, frogs and other amphibians. The Sierra Nevada Mountains separate the Central Valley in the west from the high desert of Mono Country on the east side of the state of California. The Central Valley represents some of the most heavily cultivated agricultural land in the United States. San Joaquin County alone had an annual pesticide use of over 8 million pounds in 2009 according to the Pesticide Action Network, compared with 4800 pounds in Mono County the same year. Fragile alpine ecosystems in the Sierra Nevadas may be highly susceptible to the effects of endocrine disruptors like nonylphenol. The distribution of nonylphenol is affected by localized topography in a steep walled montane canyon in the Eastern Sierra Nevada Mountains, Convict Creek canyon. The concentration of nonylphenol in snow and surface water increases as the elevation in Convict Creek canyon decreases in an easterly direction from not detectable at the highest elevations to as much as .01mg/L in water and 1.8 mg/L in snow at the lowest elevations. The steep head wall of Convict Creek canyon, facing southeast, provides shielding to the higher elevation lakes from deposition of compounds and particulate matter. As a canyon becomes less steep and broader, more nonylphenol is deposited. Identifying these deposition patterns may assist in determining amphibian and fish populations that are at higher risk of negative impact from these compounds.

77 FR 22475 - Standard Instrument Approach Procedures, and Takeoff Minimums and Obstacle Departure Procedures...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-16

..., Orig, CANCELLED Fort Huachuca Sierra Vista, AZ, Sierra Vista Muni-Libby AAF, RADAR-1, Orig Fort Huachuca Sierra Vista, AZ, Sierra Vista Muni-Libby AAF, RADAR-2, Orig Lake Havasu City, AZ, Lake Havasu... Opelousas, LA, St Landry Parish-Ahart Field, NDB RWY 18, Amdt 3 Opelousas, LA, St Landry Parish-Ahart Field...

Riparian and upland vegetation on the Kings River Experimental Watershed, Sierra Nevada, California

Treesearch

Christopher R. Dolanc; Carolyn T. Hunsaker

2007-01-01

The Kings River Experimental Watershed (KREW) is a watershed-level study on headwater streams in the Sierra Nevada, California. Eight perennial streams, from 1500 m (4920 ft) to 2490 m (8170 ft) elevation, have been instrumented and collecting data since 2002. Component research areas of the study include stream flow, water chemistry, sediment, soil chemistry, stream...

Examining Internet Usage Demographic Differences and the Relationship between Internet Usage and Business Outcomes in Sierra Leone

ERIC Educational Resources Information Center

Kamara, Mohamed K.

2013-01-01

This study utilized the unified theory of acceptance and use of technology (UTAUT) to determine Internet users' perceptions and behavioral intentions to accept Wi-Fi technology deployment in Sierra Leone. The study sought to investigate (a) the Internet usage rates before and after Wi-Fi adaption in Freetown; (b) differences in Internet usage…

Development of a Pediatric Ebola Predictive Score, Sierra Leone1.

PubMed

Fitzgerald, Felicity; Wing, Kevin; Naveed, Asad; Gbessay, Musa; Ross, J C G; Checchi, Francesco; Youkee, Daniel; Jalloh, Mohamed Boie; Baion, David E; Mustapha, Ayeshatu; Jah, Hawanatu; Lako, Sandra; Oza, Shefali; Boufkhed, Sabah; Feury, Reynold; Bielicki, Julia; Williamson, Elizabeth; Gibb, Diana M; Klein, Nigel; Sahr, Foday; Yeung, Shunmay

2018-02-01

We compared children who were positive for Ebola virus disease (EVD) with those who were negative to derive a pediatric EVD predictor (PEP) score. We collected data on all children <13 years of age admitted to 11 Ebola holding units in Sierra Leone during August 2014-March 2015 and performed multivariable logistic regression. Among 1,054 children, 309 (29%) were EVD positive and 697 (66%) EVD negative, with 48 (5%) missing. Contact history, conjunctivitis, and age were the strongest positive predictors for EVD. The PEP score had an area under receiver operating characteristics curve of 0.80. A PEP score of 7/10 was 92% specific and 44% sensitive; 3/10 was 30% specific, 94% sensitive. The PEP score could correctly classify 79%-90% of children and could be used to facilitate triage into risk categories, depending on the sensitivity or specificity required.

Post-Ebola Syndrome, Sierra Leone.

PubMed

Scott, Janet T; Sesay, Foday R; Massaquoi, Thomas A; Idriss, Baimba R; Sahr, Foday; Semple, Malcolm G

2016-04-01

Thousands of persons have survived Ebola virus disease. Almost all survivors describe symptoms that persist or develop after hospital discharge. A cross-sectional survey of the symptoms of all survivors from the Ebola treatment unit (ETU) at 34th Regimental Military Hospital, Freetown, Sierra Leone (MH34), was conducted after discharge at their initial follow-up appointment within 3 weeks after their second negative PCR result. From its opening on December 1, 2014, through March 31, 2015, the MH34 ETU treated 84 persons (8-70 years of age) with PCR-confirmed Ebola virus disease, of whom 44 survived. Survivors reported musculoskeletal pain (70%), headache (48%), and ocular problems (14%). Those who reported headache had had lower admission cycle threshold Ebola PCR than did those who did not (p<0.03). This complete survivor cohort from 1 ETU enables analysis of the proportion of symptoms of post-Ebola syndrome. The Ebola epidemic is waning, but the effects of the disease will remain.

Identifying the location and population served by domestic wells in California

USGS Publications Warehouse

Johnson, Tyler D.; Belitz, Kenneth

2015-01-01

Aggregating the results indicates that three hydrogeologic provinces contain nearly 80% of all domestic wells and also have the highest density of domestic well users: Central Valley (31.6%), Sierra Nevada (31.5%), and Northern Coast Ranges (16.6%). Results were also aggregated into groundwater basins and highland areas, collectively called Groundwater Units (GUs). Twenty-eight of the 938 GUs contain more than 50% of the total population served by domestic wells, 70 GUs contain more than 75%, and 150 GUs contain 90%. The 28 GUs are mostly located in the eastern and southern San Joaquin Valley (11), the Sacramento Valley (7), and the western foothills of the Sierra Nevada province (5). Using the information presented in this research along with other information about domestic-well use, the US Geological Survey has begun sampling high-use GUs for the Shallow Aquifer Assessment component of the Groundwater Ambient Assessment (GAMA) program.

TEMPORAL VARIATION IN PESTICIDE LEVELS IN SURFACE WATERS OF THE SOUTHERN NEVADA, CALIFORNIA

EPA Science Inventory

We sampled surface waters in Sequoia and Kings Canyon National Parks in the Sierra Nevada of California from mid June to mid October 2003. Two pesticides found commonly in previous studies of pesticides in Sierra Nevada waters, chlorpyrifos and diazinon, were found only rarely.

Sierra University in Mexico

ERIC Educational Resources Information Center

Celis, Francisco Manuel Orozco

2003-01-01

Sierra University was designed to promote the development of the mountain communities in the State of Sonora, Mexico. The university offers high school graduates an opportunity to pursue their studies in their home region, in order to stimulate economic development and contribute to social cohesion in the highlands area. The university is equipped…

Mammals

Treesearch

Marshall White; Reginald H. Barrett; Allan S. Boss; Thomas F. Newman; Thomas J. Rahn; Daniel F. Williams

1980-01-01

This chapter offers information on the status, distribution by habitat, and basic life history of 94 species of mammals inhabiting the western Sierra Nevada. These data were drawn primarily from the literature, much of which consists of reports of studies conducted in areas outside of the Sierra Nevada. Additional information was provided by the field experience of the...

Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierrae from California

USGS Publications Warehouse

Purvis, O.W.; Bennett, J.P.; Spratt, J.

2011-01-01

An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour. Copyright ?? 2011 British Lichen Society.

Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierra from California

USGS Publications Warehouse

Purvis, O.W.; Bennett, J.P.; Spratt, J.

2011-01-01

An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour.

Response of Sierra Nevada forests to projected climate-wildfire interactions.

PubMed

Liang, Shuang; Hurteau, Matthew D; Westerling, Anthony LeRoy

2017-05-01

Climate influences forests directly and indirectly through disturbance. The interaction of climate change and increasing area burned has the potential to alter forest composition and community assembly. However, the overall forest response is likely to be influenced by species-specific responses to environmental change and the scale of change in overstory species cover. In this study, we sought to quantify how projected changes in climate and large wildfire size would alter forest communities and carbon (C) dynamics, irrespective of competition from nontree species and potential changes in other fire regimes, across the Sierra Nevada, USA. We used a species-specific, spatially explicit forest landscape model (LANDIS-II) to evaluate forest response to climate-wildfire interactions under historical (baseline) climate and climate projections from three climate models (GFDL, CCSM3, and CNRM) forced by a medium-high emission scenario (A2) in combination with corresponding climate-specific large wildfire projections. By late century, we found modest changes in the spatial distribution of dominant species by biomass relative to baseline, but extensive changes in recruitment distribution. Although forest recruitment declined across much of the Sierra, we found that projected climate and wildfire favored the recruitment of more drought-tolerant species over less drought-tolerant species relative to baseline, and this change was greatest at mid-elevations. We also found that projected climate and wildfire decreased tree species richness across a large proportion of the study area and transitioned more area to a C source, which reduced landscape-level C sequestration potential. Our study, although a conservative estimate, suggests that by late century, forest community distributions may not change as intact units as predicted by biome-based modeling, but are likely to trend toward simplified community composition as communities gradually disaggregate and the least tolerant species are no longer able to establish. The potential exists for substantial community composition change and forest simplification beyond this century. © 2016 John Wiley & Sons Ltd.

Three-dimensional crustal structure of the southern Sierra Nevada from seismic fan profiles and gravity modeling

USGS Publications Warehouse

Fliedner, M.M.; Ruppert, S.; Malin, P.E.; Park, S.K.; Jiracek, G.; Phinney, R.A.; Saleeby, J.B.; Wernicke, B.; Clayton, R.; Keller, Rebecca Hylton; Miller, K.; Jones, C.; Luetgert, J.H.; Mooney, W.D.; Oliver, H.; Klemperer, S.L.; Thompson, G.A.

1996-01-01

Traveltime data from the 1993 Southern Sierra Nevada Continental Dynamics seismic refraction experiment reveal low crustal velocities in the southern Sierra Nevada and Basin and Range province of California (6.0 to 6.6 km/s), as well as low upper mantle velocities (7.6 to 7.8 km/s). The crust thickens from southeast to northwest along the axis of the Sierra Nevada from 27 km in the Mojave Desert to 43 km near Fresno, California. A crustal welt is present beneath the Sierra Nevada, but the deepest Moho is found under the western slopes, not beneath the highest topography. A density model directly derived from the crustal velocity model but with constant mantle density satisfies the pronounced negative Bouguer anomaly associated with the Sierra Nevada, but shows large discrepancies of >50 mgal in the Great Valley and in the Basin and Range province. Matching the observed gravity with anomalies in the crust alone is not possible with geologically reasonable densities; we require a contribution from the upper mantle, either by lateral density variations or by a thinning of the lithosphere under the Sierra Nevada and the Basin and Range province. Such a model is consistent with the interpretation that the uplift of the present Sierra Nevada is caused and dynamically supported by asthenospheric upwelling or lithospheric thinning under the Basin and Range province and eastern Sierra Nevada.

Photo series for quantifying forest residues in the: sierra mixed conifer type, sierra true fir type.

Treesearch

W.G. Maxwell; F.R. Ward

1979-01-01

Five series of photographs display different forest residue loading levels, by size classes, for areas of like timber type (Sierra mixed conifer and Sierra true fir) and cutting objective. Information with each photo includes measured weights, volumes and other residue data, information about the timber stand and harvest actions, and assessment of fire behavior and...

Sierra/SolidMechanics 4.46 Example Problems Manual.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plews, Julia A.; Crane, Nathan K; de Frias, Gabriel Jose

Presented in this document are tests that exist in the Sierra/SolidMechanics example problem suite, which is a subset of the Sierra/SM regression and performance test suite. These examples showcase common and advanced code capabilities. A wide variety of other regression and verification tests exist in the Sierra/SM test suite that are not included in this manual.

Site fidelity of the declining amphibian Rana sierrae (Sierra Nevada yellow-legged frog)

Treesearch

Kathleen Matthews; Haiganoush Preisler

2010-01-01

From 1997 to 2006, we used mark–recapture models to estimate the site fidelity of 1250 Sierra Nevada yellow-legged frogs (Rana sierrae) in Kings Canyon National Park, California, USA, during their three main activity periods of overwintering, breeding, and feeding. To quantify site fidelity, the tendency to return to and reuse previously occupied...

Tracking Down Batholith Construction Through Time Using Lobes From The Tuolumne Batholith, Sierra Nevada, CA.

NASA Astrophysics Data System (ADS)

Memeti, V.; Paterson, S. R.

2006-12-01

Data gained using various geologic tools from large, composite batholiths, such as the 95-85 Ma old Tuolumne Batholith (TB), Sierra Nevada, CA, indicate complex batholithic processes at the chamber construction site, in part since they record different increments of batholith construction through time. Large structural and compositional complexity generally occurs throughout the main batholith such as (1) geochemistry, (2) internal contacts between different units (Bateman, 1992; Zak &Paterson, 2005), (3) batholith/host rock contacts, (4) geochronology (Coleman et al., 2004; Matzel et al., 2005, 2006), and (5) internal structures such as schlieren layering and fabrics (Bateman, 1992; Zak et al., 2006) leading to controversies regarding batholith construction models. By using magmatic lobes tongues of individual batholithic units that extend into the host rock away from the main batholith we avoid some of the complexity that evolved over longer times within the main batholith. Magmatic lobes are "simpler" systems, because they are spatially separated from other units of the batholith and thus ideally represent processes in just one unit at the time of emplacement. Furthermore, they are shorter lived than the main batholith since they are surrounded by relatively cold host rock and "freeze in" (1) "snapshots" of batholith construction, and (2) relatively short-lived internal processes and resulting structures and composition in each individual unit. Thus, data from lobes of all batholith units representing different stages of a batholith's lifetime, help us to understand internal magmatic and external host rock processes during batholith construction. Based on field and analytic data from magmatic lobes of the Kuna Crest, Half Dome, and the Cathedral Peak granodiorites, we conclude that (1) the significance of internal processes in the lobes (fractionation versus mixing versus source heterogeneity) is unique for each individual TB unit; (2) emplacement mechanisms such as stoping, downward flow or ductile deformation of host rock act in a very short period of time (only a few 100,000 yrs); and (3) a variety of different magmatic fabrics, formed by strain caused by magma flow, marginal effects, or regional stress, can be found in each lobe. These data lead to the conclusion that the size of the studied lobes indicate the minimum pulse size for TB construction and that fractionation crystallization, even though slightly varying in its magnitude, is an important internal process in each individual TB unit.

Physical property measurements on analog granites related to the joint verification experiment

NASA Astrophysics Data System (ADS)

Martin, Randolph J., III; Coyner, Karl B.; Haupt, Robert W.

1990-08-01

A key element in JVE (Joint Verification Experiment) conducted jointly between the United States and the USSR is the analysis of the geology and physical properties of the rocks in the respective test sites. A study was initiated to examine unclassified crystalline rock specimens obtained from areas near the Soviet site, Semipalatinsk and appropriate analog samples selected from Mt. Katadin, Maine. These rocks were also compared to Sierra White and Westerly Granite which have been studied in great detail. Measurements performed to characterize these rocks were: (1) Uniaxial strain with simultaneous compressional and shear wave velocities; (2) Hydrostatic compression to 150 MPa with simultaneous compressional and shear wave velocities; (3) Attenuation measurements as a function of frequency and strain amplitude for both dry and water saturated conditions. Elastic moduli determined from the hydrostatic compression and uniaxial strain test show that the rock matrix/mineral properties were comparable in magnitudes which vary within 25 percent from sample to sample. These properties appear to be approximately isotropic, especially at high pressures. However, anisotropy evident for certain samples at pressures below 35 MPa is attributed to dominant pre-existing microcrack populations and their alignments. Dependence of extensional attenuation and Young's modulus on strain amplitude were experimentally determined for intact Sierra White granite using the hysteresis loop technique.

The Impacts of California's San Francisco Bay Area Gap on Precipitation Observed in the Sierra Nevada during Hmt and Calwater

NASA Astrophysics Data System (ADS)

White, A. B.; Neiman, P. J.; Creamean, J.; Coleman, T.; Ralph, F. M.; Prather, K. A.

2014-12-01

The National Oceanic and Atmospheric Administration (NOAA)'s Hydrometeorology Testbed (HMT; hmt.noaa.gov) conducts research on the meteorological and microphysical processes contributing to orographically enhanced precipitation. Some of HMT's precipitation research has been focused on a shallow rainfall process driven by collision-coalescence that often is undetected by the National Weather Service's operational scanning radar network, especially in the Western U.S., but that can produce rain rates that are capable of creating floods. Originally it was believed that this shallow rainfall process would occur more prevalently over the coastal mountain ranges than over the Sierra Nevada, since the higher mountains of the Sierra would force deeper atmospheric ascent and produce deeper precipitating cloud systems that extend well above the melting level. This notion was disproved when it was recently discovered that a site in the northern Sierra had nearly as large of a contribution to seasonal rainfall from this shallow rainfall process, on average, as did a habitually wet site in the coast range of Sonoma County north of San Francisco. This work examines this apparent paradox using observations collected during HMT and CalWater field campaigns. In particular, a case study from CalWater is used to highlight the interaction between a landfalling atmospheric river (AR) and the Sierra Barrier Jet (SBJ). The gap in coastal terrain associated with the San Francisco Bay area is shown to allow unprocessed, moisture-enhanced flow in the AR to reach the northern Sierra site, where the SBJ provides a lifting mechanism to create enhanced orographic precipitation as compared to a site in the southern Sierra, where AR-associated dynamics are weaker and AR flow is modified by upstream coastal terrain.

Chemical composition of snow in the northern Sierra Nevada and other areas

USGS Publications Warehouse

Feth, John Henry Frederick; Rogers, S.M.; Roberson, Charles Elmer

1964-01-01

Melting snow provides a large part of the water used throughout the western conterminous United States for agriculture, industry, and domestic supply. It is an active agent in chemical weathering, supplies moisture for forest growth, and sustains fish and wildlife. Despite its importance, virtually nothing has been known of the chemical character of snow in the western mountains until the present study.Analysis of more than 100 samples, most from the northern Sierra Nevada, but some from Utah, Denver, Colo., and scattered points, shows that melted snow is a dilute solution containing measurable amounts of some or all of the inorganic constituents commonly found in natural water. There are significant regional differences in chemical composition; the progressive increase in calcium content with increasing distance eastward from the west slope of the Sierra Nevada is the most pronounced. The chemical character of individual snowfalls is variable. Some show predominant influence of oceanic salt; others show strong effects of mineralization from continental sources, probably largely dust. Silica and boron were found in about half the samples analyzed for these constituents; precipitation is seldom analyzed for these substances.Results of the chemical analyses for major constituents in snow samples are summarized in the following table. The median and mean values for individual constituents are derived from 41-78 samples of Sierra Nevada snow, 6-18 samples of Utah snow, and 6-17 samples of Denver, Colo., snow.The sodium, chloride, and perhaps boron found in snow are probably incorporated in moisture-laden air masses as they move over the Pacific Ocean. Silica, although abundant in the silicate-mineral nuclei found in some snowflakes, may be derived in soluble form largely from dust. Calcium, magnesium, and some bicarbonate are probably added by dust of continental origin. The sources of the other constituents remain unknown.When snowmelt comes in contact with the lithosphere, the earlier diversity of chemical type largely disappears. The melt water rapidly increases its content of dissolved solids and becomes calcium magnesium bicarbonate in type. Silica, whose concentration increases more than tenfold, shows the largest gain; calcium and bicarbonate contents also increase markedly. Most of the additional mineral matter is from soft and weathered rock; bicarbonate, however, is largely from the soil atmosphere.Investigators, some reporting as much as a century ago, concentrated attention largely on nitrogen compounds and seldom reported other constituents except chloride and sulfate. The Northern European precipitation-sampling network provides the most comprehensive collection of data on precipitation chemistry, but it does not segregate snow from other forms of precipitation. The present study establishes with confidence the chemical character of snow in the Sierra Nevada, and suggests that the dissolved-solids content of precipitation increases with increasing distance inland from the Pacific Coast.

Modeling interfacial fracture in Sierra.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Arthur A.; Ohashi, Yuki; Lu, Wei-Yang

2013-09-01

This report summarizes computational efforts to model interfacial fracture using cohesive zone models in the SIERRA/SolidMechanics (SIERRA/SM) finite element code. Cohesive surface elements were used to model crack initiation and propagation along predefined paths. Mesh convergence was observed with SIERRA/SM for numerous geometries. As the funding for this project came from the Advanced Simulation and Computing Verification and Validation (ASC V&V) focus area, considerable effort was spent performing verification and validation. Code verification was performed to compare code predictions to analytical solutions for simple three-element simulations as well as a higher-fidelity simulation of a double-cantilever beam. Parameter identification was conductedmore » with Dakota using experimental results on asymmetric double-cantilever beam (ADCB) and end-notched-flexure (ENF) experiments conducted under Campaign-6 funding. Discretization convergence studies were also performed with respect to mesh size and time step and an optimization study was completed for mode II delamination using the ENF geometry. Throughout this verification process, numerous SIERRA/SM bugs were found and reported, all of which have been fixed, leading to over a 10-fold increase in convergence rates. Finally, mixed-mode flexure experiments were performed for validation. One of the unexplained issues encountered was material property variability for ostensibly the same composite material. Since the variability is not fully understood, it is difficult to accurately assess uncertainty when performing predictions.« less

Burn Severity and Its Impact on Soil Properties: 2016 Erskine Fire in the Southern Sierra Nevada

NASA Astrophysics Data System (ADS)

Haake, S.; Guo, J.; Krugh, W. C.

2017-12-01

Wildfire frequency in the southern Sierra Nevada has increased over the past decades. The effects of wildfires on soils can increase the frequency of slope failure and debris flow events, which pose a greater risk to people, as human populations expand into foothill and mountainous communities of the Sierra Nevada. Alterations in the physical properties of burned soils are one such effect that can catalyze slope failure and debris flow events. Moreover, the degree of a soil's physical alteration resulting from wildfire is linked to fire intensity. The 2016 Erskine fire occurred in the southern Sierra Nevada, burning 48,019 acres, resulting in soils of unburned, low, moderate, and high burn severities. In this study, the physical properties of soils with varying degrees of burn severity are explored within the 2016 Erskine fire perimeter. The results constrain the effects of burn severity on soil's physical properties. Unburned, low, moderate, and high burn severity soil samples were collected within the Erskine fire perimeter. Alterations in soils' physical properties resulting from burn severity are explored using X-ray diffractometry analysis, liquid limit, plastic limit, and shear strength tests. Preliminary results from this study will be used to assess debris flow and slope failure hazard models within burned areas of the Kern River watershed in the southern Sierra Nevada.

Differences in wildfires among ecoregions and land management agencies in the Sierra Nevada region, California, USA

Treesearch

Jay D. Miller; Brandom M. Collins; James A. Lutz; Scott L. Stephens; Jan W. van Wagtendonk; Donald A. Yasuda

2012-01-01

Recent research has indicated that in most of the western United States, fire size is increasing, large fires are becoming more frequent, and in at least some locations percentage of high-severity fire is also increasing. These changes in the contemporary fire regime are largely attributed to both changing climate and land management practices, including suppression of...

China and United Nations Peacekeeping Operations in Africa

DTIC Science & Technology

2007-01-01

November 2006 China-Africa Economic Forum , hosted by Beijing and attended by forty-eight African nations, President Hu promised that China would...scholarships to four thousand African students, and develop increasingly closer ties over the succeeding decade.7 This forum and China’s actions with...and Eritrea (UNMEE), Liberia (UNMIL), Sudan (UNMIS), Sierra Leone (UNIOSIL), and the Western Sahara (MINURSO, discussed at length below). The Chinese

Prioritizing forest fuels treatments based on the probability of high-severity fire restores adaptive capacity in Sierran forests

Treesearch

Daniel J. Krofcheck; Matthew D. Hurteau; Robert M. Scheller; E. Louise Loudermilk

2017-01-01

In frequent fire forests of the western United States, a legacy of fire suppression coupled with increases in fire weather severity have altered fire regimes and vegetation dynamics. When coupled with projected climate change, these conditions have the potential to lead to vegetation type change and altered carbon (C) dynamics. In the Sierra Nevada, fuels...

Response of Subalpine Conifers in the Sierra Nevada, California, U.S.A., to 20th-Century Warming and Decadal Climate Variability

Treesearch

Constance I. Millar; Robert D. Westfall; Diane L. Delany; John C. King; Lisa J. Graumlich

2004-01-01

Four independent studies of conifer growth between 1880 and 2002 in upper elevation forests of the central Sierra Nevada, California, U.S.A., showed correlated multidecadal and century-long responses associated with climate. Using tree-ring and ecological plot analysis, we studied annual branch growth of krummholz Pinus albicaulis; invasion by P....

Evaluating avian-habitat relationships models in mixed-conifer forests of the Sierra Nevada

Treesearch

Kathryn L. Purcell; Sallie J. Hejl; Terry A. Larson

1992-01-01

Using data from two studies in the southern and central Sierra Nevada, we compared the presence and abundance of bird species breeding in mixedconifer forests during 1978-79 and 1983-85 to predictions &om the California Wildlife Habitat Relationships (WHR) System. Twelve percent of the species observed in either study were not predicted by the WHR database to occur...

Meta-analysis of California Spotted Owl (Strix occidentalis occidentalis) territory occupancy in the Sierra Nevada: habitat associations and their implications for forest management

Treesearch

Douglas J. Tempel; John J. Keane; R. J. Gutierrez; Jared D. Wolfe; Gavin M. Jones; Alexander Koltunov; Carlos M. Ramirez; William J. Berigan; Claire V. Gallagher; Thomas E. Munton; Paula A. Shaklee; Sheila A. Whitmore; M. Zachariah Peery

2016-01-01

We assessed the occupancy dynamics of 275 California Spotted Owl (Strix occidentalis occidentalis) territories in 4 study areas in the Sierra Nevada, California, USA, from 1993 to 2011. We used Landsat data to develop maps of canopy cover for each study area, which we then used to quantify annual territory-specific habitat...

GPS and InSAR Observations of Active Mountain Growth Across the Sierra Nevada/Great Basin Transition

NASA Astrophysics Data System (ADS)

Hammond, W. C.; Blewitt, G.; Li, Z.; Kreemer, C. W.; Plag, H.

2010-12-01

Topographic relief across the Sierra Nevada Mountains and Great Basin of the western United States is dominated by mountain ranges and valleys that are the product of active tectonic deformation. The contemporary rate of uplift of the Sierra Nevada via slip on range front faults and/or tilting of the Sierra Nevada/Great Valley microplate (SNGV) has been the subject of controversy. For example, geologic estimates of the age of the modern range topography vary by one order of magnitude, from 3 to 30 million years. With present elevations near 3 km, the more rapid of these implied rates is large enough to be detected by the most precise GPS measurements. We use GPS vertical and horizontal components, and InSAR time series analysis to address these long standing questions about the rates of Sierran uplift. The data are from western U.S. high precision GPS networks including the EarthScope Plate Boundary Observatory, its nucleus networks, the University of Nevada Mobile Array of GPS for Nevada Transtension, and from integrated InSAR+GPS time series analysis of ERS and ENVISAT scenes acquired between 1992 and 2010 from the GeoEarthScope and WinSAR data archives. GPS data are processed using the GIPSY OASIS II software, with ambiguities resolved, ocean tidal loading, latest GMF troposphere model and antenna calibrations applied. InSAR time series analysis results provide enhanced geographic resolution, improving our ability to locate the boundary of SNGV block-like behavior. Vertical velocities from long-running continuous stations in eastern Nevada are very similar to one another, averaging -0.1 mm/yr, with standard deviation of 0.27 mm/yr, placing an upper bound on the uncertainty in vertical rates. We find agreement between the results of InSAR time series analysis aligned to GPS and GPS line of site rates at the level of 0.35 mm/yr, placing an upper bound on the uncertainty of InSAR time series results. Because we seek to infer long-term uplift rates, applicable over millions of years, we correct the geodetic velocity field for postseismic transients from earthquakes that can cause long-wavelength distortions of the GPS velocity field. The signal of viscoelastic relaxation from historic earthquakes in Central Nevada is clearly visible in the data. We remove this transient relaxation by subtracting the predictions from a published model, although the effect on SNGV vertical motion is negligible. There is general agreement among stations on the west slope of the Sierra Nevada, near the central and southern Sierra between latitude 36° and 39°, that the rates are between 0.8 and 1.6 mm/yr upward with respect to eastern Nevada. These rates are in broad agreement with normal slip rates on the range front faults along the eastern edge of the SNGV estimated using block models constrained by horizontal GPS measurements. Thus our results agree with models that call for a Sierra Nevada uplift rate near 1 mm/yr, and a younger Sierra Nevada whose age is on the order of 3 Ma.

The future of biodiversity in the Sierra Nevada through the Lake Tahoe Basin Looking Glass

Treesearch

Patricia N. Manley

2004-01-01

The Sierra Nevada’s biological distinction and diversity are almost as legendary as its spectacular peaks and beautiful granite landscapes. The Sierra Nevada is recognized as a zoogeographic region on the basis of the coincidence of species ranges (for example, Udvardy 1969, 1975; Welsh 1994). Udvardy (1969) defined the Sierra Nevada bioregion as bounded by the Great...

77 FR 37801 - Standard Instrument Approach Procedures, and Takeoff Minimums and Obstacle Departure Procedures...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-25

... 17, Amdt 6 Fort Huachuca Sierra Vista, AZ, Sierra Vista Muni-Libby AAF, ILS OR LOC RWY 26, Amdt 4 Fort Huachuca Sierra Vista, AZ, Sierra Vista Muni-Libby AAF, VOR RWY 26, Amdt 5 Willcox, AZ, Cochise... 35, Amdt 1 La Grange, TX, Fayette Rgnl Air Center, RNAV (GPS) RWY 16, Amdt 2 La Grange, TX, Fayette...

9 CFR 97.2 - Administrative instructions prescribing commuted traveltime.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Palmer 3 Arizona: Douglas 1 Do Nogales 6 Do Phoenix 6 Do Sierra Vista 3 Naco Douglas 2 Do Nogales 4 Do Phoenix 6 Do Sierra Vista 2 Nogales 1 Do Douglas 6 Do Phoenix 6 Do Sierra Vista 3 San Luis Phoenix 6 Do Yuma 2 Sasabe Douglas 6 Do Nogales 4 Do Phoenix 6 Do Sierra Vista 6 Do Tuscon 3 California: Calexico...

9 CFR 97.2 - Administrative instructions prescribing commuted traveltime.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Palmer 3 Arizona: Douglas 1 Do Nogales 6 Do Phoenix 6 Do Sierra Vista 3 Naco Douglas 2 Do Nogales 4 Do Phoenix 6 Do Sierra Vista 2 Nogales 1 Do Douglas 6 Do Phoenix 6 Do Sierra Vista 3 San Luis Phoenix 6 Do Yuma 2 Sasabe Douglas 6 Do Nogales 4 Do Phoenix 6 Do Sierra Vista 6 Do Tuscon 3 California: Calexico...

9 CFR 97.2 - Administrative instructions prescribing commuted traveltime.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Palmer 3 Arizona: Douglas 1 Do Nogales 6 Do Phoenix 6 Do Sierra Vista 3 Naco Douglas 2 Do Nogales 4 Do Phoenix 6 Do Sierra Vista 2 Nogales 1 Do Douglas 6 Do Phoenix 6 Do Sierra Vista 3 San Luis Phoenix 6 Do Yuma 2 Sasabe Douglas 6 Do Nogales 4 Do Phoenix 6 Do Sierra Vista 6 Do Tuscon 3 California: Calexico...

9 CFR 97.2 - Administrative instructions prescribing commuted traveltime.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Palmer 3 Arizona: Douglas 1 Do Nogales 6 Do Phoenix 6 Do Sierra Vista 3 Naco Douglas 2 Do Nogales 4 Do Phoenix 6 Do Sierra Vista 2 Nogales 1 Do Douglas 6 Do Phoenix 6 Do Sierra Vista 3 San Luis Phoenix 6 Do Yuma 2 Sasabe Douglas 6 Do Nogales 4 Do Phoenix 6 Do Sierra Vista 6 Do Tuscon 3 California: Calexico...

9 CFR 97.2 - Administrative instructions prescribing commuted traveltime.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Palmer 3 Arizona: Douglas 1 Do Nogales 6 Do Phoenix 6 Do Sierra Vista 3 Naco Douglas 2 Do Nogales 4 Do Phoenix 6 Do Sierra Vista 2 Nogales 1 Do Douglas 6 Do Phoenix 6 Do Sierra Vista 3 San Luis Phoenix 6 Do Yuma 2 Sasabe Douglas 6 Do Nogales 4 Do Phoenix 6 Do Sierra Vista 6 Do Tuscon 3 California: Calexico...

Bedrock river networks of the Sierra Nevada, USA record westward tilting, large-scale drainage area loss, and distinct patterns and causes of stream incision between the northern and southern Sierra

NASA Astrophysics Data System (ADS)

Beeson, H. W.; McCoy, S. W.

2017-12-01

The timing, rates, and spatial patterns of elevation change in the Sierra Nevada, California, USA, has been the subject of vigorous debate with multiple lines of evidence supporting the contrasting hypotheses that (1) the Sierra has been topographically high throughout the Cenozoic and (2) that the range has experienced a pulse of late Cenozoic uplift. We combined 2-D landscape evolution modeling with topographic analysis of the Sierra Nevada to investigate whether river networks dissecting the range record a change in tectonic forcing during the late Cenozoic. Specifically, we quantify basin geometry, including its area-channel length scaling relationship, fluvial channel steepness, and the spatial distributions of knickzones. We show that, throughout the Sierra, short equilibrated reaches near the mountain front are consistent with an ongoing westward tilt. However, the disequilibrium forms of river profiles north of the Kaweah River reflect large-scale drainage area loss due to network beheading by the Sierra Frontal Fault and/or reestablishment of a fluvial network on an inclined planar surface. Despite these similarities along the length of the range, river network analysis reveals striking differences north and south of approximately 37° N. In the northern Sierra, topographic asymmetry of drainage divides and large differences in cross-divide steady-state elevation suggest mobile divides. Additionally, the broad distribution of normalized knickzone locations, variability in channel steepness and basin shape, and the prevalence of anomalous topology, narrow basins, unadjusted captured reaches, and wind gaps is consistent with large-scale drainage reorganization following incision into an inclined planar surface. In contrast, in the southern Sierra, drainage divides appear more stable and knickzone locations are tightly distributed. We suggest that, although the northern Sierra may currently be tilting westward, the presence of large knickzones and deeply incised valleys in the northern Sierra does not require a recent increase in uplift, but rather could largely reflect the reestablishment of a fluvial network after mid-late Miocene volcanism filled and smoothed preexisting topography. In contrast, it appears that the southern Sierras are responding to a pulse of localized rapid uplift.

The Mammoth-June Ecosystem Management Project, Inyo National Forest

Treesearch

Connie Millar

1996-01-01

The Sierra Nevada Ecosystem Project (SNEP) case-study assessmentof the Mammoth-June Ecosystem Management Project(MJEMP) was undertaken to review and analyze the efficacy of alocal landscape analysis in achieving ecosystem-management objectivesin the Sierra Nevada. Of primary interest to SNEP was applicationof the new U.S. Forest Service (USFS) regional process...

Riparian Communities of the Sierra Nevada and their Environmental Relationships

Treesearch

Richard R. Harris

1989-01-01

Data on riparian community composition and environmental conditions were collected on over 20 streams in the Sierra Nevada as part of hydropower licensing studies. Over 1,000 samples were analyzed using two-way indicator species analysis (TWINSPAN), to determine riparian dominance types. Ordination techniques were applied to evaluate associations between environmental...

Sierra Leone's Former Child Soldiers: A Longitudinal Study of Risk, Protective Factors, and Mental Health

ERIC Educational Resources Information Center

Betancourt, Theresa S.; Brennan, Robert T.; Rubin-Smith, Julia; Fitzmaurice, Garrett M.; Gilman, Stephen E.

2010-01-01

Objective: To investigate the longitudinal course of internalizing and externalizing problems and adaptive/prosocial behaviors among Sierra Leonean former child soldiers and whether postconflict factors contribute to adverse or resilient mental health outcomes. Method: Male and female former child soldiers (N = 260, aged 10 to 17 years at…

Airborne SAR determination of relative ages of Walker Valley moraines, eastern Sierra Nevada

NASA Technical Reports Server (NTRS)

Fox, A.; Isacks, B.; Bloom, A.; Fielding, E.; Mcmurry, D.

1991-01-01

A regional study of the distribution and elevations of Pleistocene moraines in the Andes requires a method of determining relative age from space. One of our primary objectives is to establish the relative chronology of major climatic events responsible for glaciation in the Andes and other regions that are difficult to access on the ground and where suitable material for absolute age determination is lacking. The sensitivity of radar to surface roughness makes it possible to develop a remotely-based relative dating technique for landforms for which surface age and roughness can be correlated. We are developing such a technique with Airborne Synthetic Aperture Radar (AIRSAR) imagery of the eastern Sierra Nevada where independent evidence is available for the ages and physical characteristics of moraines. The Sierra Nevada moraines are similar in form and environmental setting to Andean moraines that we have targeted for study during the pending Shuttle Imaging Radar-C (SIR-C) mission. SAR imagery is used to differentiate the ages of five moraine sequences of Walker Valley in the eastern Sierra Nevada. Other aspects of this investigation are briefly discussed.

Ethical challenges experienced by UK military medical personnel deployed to Sierra Leone (operation GRITROCK) during the 2014-2015 Ebola outbreak: a qualitative study.

PubMed

Draper, Heather; Jenkins, Simon

2017-12-19

As part of its response to the 2014 Ebola outbreak in west Africa, the United Kingdom (UK) government established an Ebola treatment unit in Sierra Leone, staffed by military personnel. Little is known about the ethical challenges experienced by military medical staff on humanitarian deployment. We designed a qualitative study to explore this further with those who worked in the treatment unit. Semi-structured, face-to-face and telephone interviews were conducted with 20 UK military personnel deployed between October 2014 and April 2015 in one of three roles in the Ebola treatment unit: clinician; nursing and nursing assistant; and other medical support work, including infection control and laboratory and mortuary services. Many participants reported feeling ethically motivated to volunteer for deployment, but for some personal interests were also a consideration. A small minority had negative feelings towards the deployment, others felt that this deployment like any other was part of military service. Almost all had initial concerns about personal safety but were reassured by their pre-deployment 'drills and skills', and personal protective equipment. Risk perceptions were related to perceptions about military service. Efforts to minimise infection risk were perceived to have made good patient care more difficult. Significantly, some thought the humanitarian nature of the mission justified tolerating greater risks to staff. Trust in the military institution and colleagues was expressed; many participants referred to the ethical obligation within the chain of command to protect those under their command. Participants expected resources to be overwhelmed and 'empty beds' presented a significant and pervasive ethical challenge. Most thought more patients could and should have been treated. Points of reference for participants' ethical values were: previous deployment experience; previous UK/National Health Service experience; professional ethics; and, distinctly military values (that might not be shared with non-military workers). We report the first systematic exploration of the ethical challenges face by a Western medical military in the international response to the first major Ebola outbreak. We offer unique insights into the military healthcare workers' experiences of humanitarian deployment. Many participants expressed motivations that gave them common purpose with civilian volunteers.

Gallstone disease in Peruvian coastal natives and highland migrants

PubMed Central

Moro, P; Checkley, W; Gilman, R; Cabrera, L; Lescano, A; Bonilla, J; Silva, B

2000-01-01

BACKGROUND—In a previous study, we found that gallstones were a common occurrence in the high altitude villages of the Peruvian Andes.
AIMS—To determine if high altitude (⩾ 1500 m) is a contributing risk factor for gallstone disease.
METHODS—We conducted a cross sectional study in a periurban community in Lima, Peru, and compared the prevalence of gallstone disease between coastal natives, highland (Sierra) natives and Sierra natives who had migrated to the coast. We also compared the prevalence rates from this study with those from a previous study conducted at high altitude. We examined 1534 subjects >15 years of age for gallstone disease. Subjects were interviewed for the presence or absence of risk factors.
RESULTS—Gallstone disease was more common in females (16.1 cases per 100, 95% CI 13.8-18.2) than in males (10.7 per 100, 95% CI 8.0-13.4). Females had a greater risk of gallstone disease, especially if they had used oral contraception and/or had four or more children. The age adjusted prevalence was not significantly different between coastal natives, Sierra migrants, and Andean villagers. The prevalence of gallstone disease was not associated with time since migration or with having native Sierra parents. After adjusting for other risk factors, Sierra natives who migrated to the coast had a lower prevalence of gallstone disease than coastal natives (odds ratio 0.74, 95% CI 0.58-0.94).
CONCLUSIONS—This study indicates that high altitude is not a positive risk factor for gallstone disease and confirms that this disease is common in Peruvians, which may be attributable to Peruvian-Indian ethnicity.


Keywords: gallstone disease; cholelithiasis; high altitude; risk factors; epidemiology; Peru PMID:10716689

Sierra/SolidMechanics 4.48 User's Guide: Addendum for Shock Capabilities.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plews, Julia A.; Crane, Nathan K; de Frias, Gabriel Jose

This is an addendum to the Sierra/SolidMechanics 4.48 User's Guide that documents additional capabilities available only in alternate versions of the Sierra/SolidMechanics (Sierra/SM) code. These alternate versions are enhanced to provide capabilities that are regulated under the U.S. Department of State's International Traffic in Arms Regulations (ITAR) export-control rules. The ITAR regulated codes are only distributed to entities that comply with the ITAR export-control requirements. The ITAR enhancements to Sierra/SM in- clude material models with an energy-dependent pressure response (appropriate for very large deformations and strain rates) and capabilities for blast modeling. Since this is an addendum to the standardmore » Sierra/SM user's guide, please refer to that document first for general descriptions of code capability and use.« less

Population declines lead to replicate patterns of internal range structure at the tips of the distribution of the California red-legged frog (Rana draytonii)

USGS Publications Warehouse

Richmond, Jonathan Q.; Backlin, Adam R.; Tatarian, Patricia J.; Solvesky, Ben G.; Fisher, Robert N.

2014-01-01

Demographic declines and increased isolation of peripheral populations of the threatened California red-legged frog (Rana draytonii) have led to the formation of internal range boundaries at opposite ends of the species’ distribution. While the population genetics of the southern internal boundary has been studied in some detail, similar information is lacking for the northern part of the range. In this study, we used microsatellite and mtDNA data to examine the genetic structuring and diversity of some of the last remaining R. draytonii populations in the northern Sierra Nevada, which collectively form the northern external range boundary. We compared these data to coastal populations in the San Francisco Bay Area, where the species is notably more abundant and still exists throughout much of its historic range. We show that ‘external’ Sierra Nevada populations have lower genetic diversity and are more differentiated from one another than their ‘internal’ Bay Area counterparts. This same pattern was mirrored across the distribution in California, where Sierra Nevada and Bay Area populations had lower allelic variability compared to those previously studied in coastal southern California. This genetic signature of northward range expansion was mirrored in the phylogeography of mtDNA haplotypes; northern Sierra Nevada haplotypes showed greater similarity to haplotypes from the south Coast Ranges than to the more geographically proximate populations in the Bay Area. These data cast new light on the geographic origins of Sierra Nevada R. draytonii populations and highlight the importance of distinguishing the genetic effects of contemporary demographic declines from underlying signatures of historic range expansion when addressing the most immediate threats to population persistence. Because there is no evidence of contemporary gene flow between any of the Sierra Nevada R. draytonii populations, we suggest that management activities should focus on maintaining and creating additional ponds to support breeding within typical dispersal distances of occupied habitat.

Sierra Nevada Science Review. Report of the Science Review Team charged to synthesize new information of rangewide urgency to the national forests of the Sierra Nevada.

Treesearch

Constance Millar; Amy Lind; Rowan Rowntree; Carl Skinner; Jared Verner; William J. Zielinski; Robert R. Ziemer

1998-01-01

In January, 1998, the Pacific Southwest Region and Pacific Southwest Research Station of the Forest Service initiated a collaborative effort to incorporate new information into planning future management of Sierra Nevada national forests. The project, known as the Sierra Nevada Framework for Conservation and Collaboration, will incorporate the latest scientific...

Analysis of Security Sector Reform in Post-Conflict Sierra Leone: A Comparison of Current versus Historical Capabilities

DTIC Science & Technology

2010-03-01

6 A. M. Fitz -Gerald, Security Sector Reform in Sierra Leone. Shrivenham, GFN-SSR. 8–10. Osman Gbla...34Security Sector Reform: Bringing the Private in.", 1– 23; Peter Albrecht and Paul Jackson, eds. Security System Transformation in Sierra Leone, 1997–2007...veterans.38 33 John R. Cartwright, Political leadership in Sierra Leone (Toronto: University of

AmeriFlux US-CZ2 Sierra Critical Zone, Sierra Transect, Ponderosa Pine Forest, Soaproot Saddle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goulden, Michael

This is the AmeriFlux version of the carbon flux data for the site US-CZ2 Sierra Critical Zone, Sierra Transect, Ponderosa Pine Forest, Soaproot Saddle. Site Description - Half hourly data are available at https://www.ess.uci.edu/~california/. This site is one of four Southern Sierra Critical Zone Observatory flux towers operated along an elevation gradient (sites are USCZ1, USCZ2, USCZ3 and USCZ4). This site is an oak/pine forest, with occasional thinning and wildfire, a prescribed understory burn ~2012, and severe drought and ~80% canopy mortality in 2011-15

AmeriFlux US-CZ3 Sierra Critical Zone, Sierra Transect, Sierran Mixed Conifer, P301

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goulden, Michael

This is the AmeriFlux version of the carbon flux data for the site US-CZ3 Sierra Critical Zone, Sierra Transect, Sierran Mixed Conifer, P301. Site Description - Half hourly data are available at https://www.ess.uci.edu/~california/. This site is one of four Southern Sierra Critical Zone Observatory flux towers operated along an elevation gradient (sites are USCZ1, USCZ2, USCZ3 and USCZ4). This site is a pine/fir forest; it historically experienced logging and wildfire, was thinned in ~2012, and experienced severe drought and ~20% canopy mortality in 2011-15.

Crustal extension and magmatism during the mid-Cenozoic ignimbrite flare-up in the Guazapares Mining District and Cerocahui basin regions, northern Sierra Madre Occidental, western Chihuahua, Mexico

NASA Astrophysics Data System (ADS)

Murray, Bryan Patrick

Silicic large igneous provinces are significant in the geologic record, due to their unusually extensive areal coverage (>100,000 km2) and large volumes (>250,000 km3), and may be characteristic of continental regions undergoing broad lithospheric extension. The Sierra Madre Occidental of northwestern Mexico is the biggest and best-preserved silicic large igneous province of the Cenozoic and is considered part of the extensive mid-Cenozoic ignimbrite flare-up that affected much of the southwestern North American Cordillera. Despite its size and preservation, very little is known about the geology of the Sierra Madre Occidental, and the timing and spatial extent of ignimbrite flare-up volcanism in relation to crustal extension is relatively unknown. This study presents new geologic mapping, stratigraphy, zircon U-Pb laser ablation ICP-MS dating, modal analysis, and geochemical data from the Guazapares Mining District and Cerocahui basin regions, two adjacent areas of the northern Sierra Madre Occidental in western Chihuahua. The rock exposure and topographic relief in this previously unmapped ~450 km2 area make it ideal for studying the relationships between silicic large igneous province volcanism and crustal extension. Three informal formations are identified in the study area: (1) the ca. 27.5 Ma Parajes formation, a ~1-km-thick succession of primarily welded silicic outflow ignimbrite sheets erupted from sources within ~50--100 km of the study area that were active during the Early Oligocene pulse of the mid-Cenozoic ignimbrite flare-up; (2) the ca. 27--24.5 Ma Temoris formation, composed primarily of locally erupted mafic-intermediate lavas and associated intrusions with interbedded alluvial deposits, likely related to rocks of the Southern Cordillera basaltic andesite province that were intermittently erupted across all of the northern Sierra Madre Occidental following the Early Oligocene ignimbrite pulse; and (3) the ca. 24.5--23 Ma Sierra Guazapares formation, composed of silicic vent to proximal facies ignimbrites, lavas, plugs, and reworked equivalents that record the initiation of explosive and effusive silicic fissure magmatism in the study area during the Early Miocene pulse of the mid-Cenozoic ignimbrite flare-up. The Guazapares Mining District and Cerocahui basin regions share this stratigraphy, but the rocks in the Cerocahui basin consist of a much higher proportion of alluvial deposits. The main geologic structures in the Guazapares Mining District and Cerocahui basin regions are NNW-trending normal faults, with an estimated minimum of 20% total horizontal extension. Many normal faults bound half-graben basins that show evidence of syndepositional extension. Normal faulting began by ca. 27.5 Ma during deposition of the youngest ignimbrites of the Parajes formation, concurrent with the end of the Early Oligocene silicic ignimbrite pulse of the ignimbrite flare-up to the east and before magmatism began in the study area. Preexisting normal faults localized mafic-intermediate volcanic vents of the Temoris formation and silicic vents of the Sierra Guazapares formation, and were active during deposition of these formations. In addition, the localization and timing of epithermal mineralization in the Guazapares Mining District appears to be favored where pre-to-synvolcanic extensional structures are in close association with Sierra Guazapares formation rhyolite plugs. The timing of extensional faulting and magmatism in the Guazapares Mining District and Cerocahui regions is consistent with regional-scale Middle Eocene to Early Miocene southwestward migration of active volcanism and extension in the northern Sierra Madre Occidental. Extension accompanied mafic-intermediate and silicic volcanism in the study area, and overlapped with the peak of mid-Cenozoic ignimbrite flare-up in the Sierra Madre Occidental; this supports the interpretation that there is likely a relationship between lithospheric extension and silicic large igneous province magmatism.

Sierra/SolidMechanics 4.48 Goodyear Specific.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plews, Julia A.; Crane, Nathan K; de Frias, Gabriel Jose

This document covers Sierra/SolidMechanics capabilities specific to Goodyear use cases. Some information may be duplicated directly from the Sierra/SolidMechanics User's Guide but is reproduced here to provide context for Goodyear-specific options.

Potential climatic refugia in semi-arid, temperate mountains: plant and arthropod assemblages associated with rock glaciers, talus slopes, and their forefield wetlands, Sierra Nevada, California, USA

Treesearch

Constance I. Millar; Robert D. Westfall; Angela Evenden; Jeffrey G. Holmquist; Jutta Schmidt-Gengenbach; Rebecca S. Franklin; Jan Nachlinger; Diane L. Delany

2015-01-01

Unique thermal and hydrologic regimes of rock-glacier and periglacial talus environments support little-studied mountain ecosystems. We report the first studies of vascular plant and arthropod diversity for these habitats in the central Sierra Nevada, California, USA. Surfaces of active rock glaciers develop scattered islands of soil that provide habitat for vegetation...

Overstory and understory dynamics in a ponderosa pine plantation vary with stand density in the Sierra Nevada: 40-year results

Treesearch

Jianwei Zhang; William W. Oliver; Martin W. Ritchie; Donald L. Neal

2013-01-01

We periodically measured overstory ponderosa pine (Pinus ponderosa) growth and understory cover and abundance in a long-term study on the west slope of the Sierra Nevada, California, USA. The study was established in 1969 in a 20-year-old plantation, thinned to basal areas of 9, 16, 23, 30, and 37 m2 ha-1...

Structural terranes and their relationships in Sierra Leone

NASA Astrophysics Data System (ADS)

Williams, Howard R.; Culver, Stephen J.

Sierra Leone, composed mainly of Archaean granite-greenstone terrane, is bounded in the west by a westward dipping zone of intense, ductile, simple shear deformation which produced very fine-grained, high grade rocks. This zone has been interpreted as a possible Archaean suture developed following the collision of the Guyana Shield and the West African Craton. Granulite facies metamorphic supracrustals of the Kasila Group occur to the west of the sheared zone. Marampa Group lower grade metamorphics were thrust eastwards during the collision event. Late Precambrian rifting, well to the east of the mylonite zone and subsequent compression, preserved very low grade to unmetamorphosed Rokel River Group sediments and volcanics. Limited Pan-African tectonic transport of Archaean and late Precambrian material was again toward the east. All structural and stratigraphic units can be traced northward into Guinea where they disappear beneath the Paleozoic sediments of the Bové Basin. To the south, the Kasila Group, the granite-greenstone terrane and the mylonitized zone can be traced into Liberia. The Gibi Mountain Formation of Liberia is probably laterally equivalent to the lower portions of the Rokel River Group. This interpretation of the geology of Sierra Leone differs greatly from that of Guinea where the mylonitized zone, associated with a positive gravity anomaly, has been interpreted as a suture zone resulting from Pan-African continent-continent collision.

A New Sample Transect through the Sierra Madre Occidental Silicic Large Igneous Province in Southern Chihuahua State, Mexico: First Stratigraphic, Petrologic, and Geochemical Results

NASA Astrophysics Data System (ADS)

Andrews, G. D.; Davila Harris, P.; Brown, S. R.; Anderson, L.; Moreno, N.

2014-12-01

We completed a field sampling transect across the northern Sierra Madre Occidental silicic large igneous province (SMO) in December 2013. Here we present the first stratigraphic, petrological, and geochemical data from the transect between Hidalgo del Parral and Guadalupe y Calvo, Chihuahua, Mexico. This is the first new transect across the SMO in 25 years and the only one between existing NE - SW transects at Chihuahua - Hermosillo and Durango - Mazatlan. The 245 km-long transect along Mexican Highway 24 crosses the boundary between the extended (Basin and Range) and non-extended (Sierra Madre Occidental plateau) parts of the SMO, and allows sampling of previously undescribed Oligocene (?) - early Miocene (?) rhyolitic ignimbrites and lavas, and occasional post-rhyolite, Miocene (?) SCORBA basaltic andesite lavas. 54 samples of rhyolitic ignimbrites (40) and lavas (7), and basaltic andesite lavas (7) were sampled along the transect, including 8 canyon sections with more than one unit. The ignimbrites are overwhelming rhyodacitic (plagioclase and hornblende or biotite phyric) or rhyolitic (quartz (+/- sanidine) in additon to plagioclase and hornblende or biotite phyric) and sparsely to highly phyric. Preliminary petrographic (phenocryst abundances) and geochemical (major and trace element) will be presented and compared to existing data from elsewhere in the SMO. Future work will include U-Pb zircon dating and whole rock and in-zircon radiogenic isotopes analyses.

Petrography of the Paleogene Volcanic Rocks of the Sierra Maestra, Southeastern Cuba

NASA Astrophysics Data System (ADS)

Bemis, V. L.

2006-12-01

This study is a petrographic analysis of over 200 specimens of the Paleogene volcanic rocks of the Sierra Maestra (Southerneastern Cuba), a key structure in the framework of the northern Caribbean plate boundary evolution. The purpose of this study is to understand the eruptive processes and the depositional environments. The volcanic sequence in the lower part of the Sierra Maestra begins with highly porphyritic pillow lavas, topped by massive tuffs and autoclastic flows. The presence of broken phenocrystals, palagonitic glass and hyaloclastites in this section of the sequence suggests that the prevalent mode of eruption was explosive. The absence of welding in the tuffs suggests that the rocks were emplaced in a deep submarine environment. Coherent flows, much less common than the massive tuffs, show evidence of autoclastic fracturing, also indicating low temperature-submarine environments. These observations support the hypothesis that the Sierra Maestra sequence may be neither part of the Great Antilles Arc of the Mesozoic nor any other fully developed volcanic arc, rather a 250 km long, submarine eruptive system of dikes, flows and sills, most likely a back-arc structure. The volcanic rocks of the upper sequence are all very fine grained, reworked volcaniclastic materials, often with the structures of distal turbidities, in mode and texture similar to those drilled on the Cayman Rise. This study suggests that the Sierra Maestra most likely records volcanism of diverse sources: a local older submarine source, and one or more distal younger sources, identifiable with the pan-Caribbean volcanic events of the Tertiary.

Ebola Virus: a Clear and Present Danger

PubMed Central

2014-01-01

An epidemic of Ebola virus disease is occurring in Western Africa on a scale not seen before, particularly in the countries of Guinea, Liberia, and Sierra Leone. The continued spread is facilitated by insufficient medical facilities, poor sanitation, travel, and unsafe burial practices. Several patients diagnosed with Ebola virus disease in Africa have been evacuated to the United States for treatment, and several other patients have been diagnosed in the United States. It is important for laboratories to be aware of available tests, especially those granted emergency use authorization, as hospitals prepare protocols for the diagnosis and management of high-risk patients. PMID:25392362

Chapter 12: The variable-density thinning study at Stanislaus-Tuolumne Experimental Forest

Treesearch

E. Knapp; M. North; M. Benech; B. Estes

2012-01-01

Prior to historical logging and fire suppression, forests of the Sierra Nevada were extremely heterogeneous. Frequent low- to moderate-intensity fire was partly responsible for this heterogeneity, which in turn helped make forests resilient to high-severity stand-replacing events. Early observers of forests on the west slope of the Sierra Nevada noted the...

Diets of California spotted owls in the Sierra National Forest

Treesearch

Thomas E. Munton; Kenneth D. Johnson; George N. Steger; Gary P. Eberlein

2002-01-01

From May 1987 through October 1992 and from July through August 1998, we studied diets of California spotted owls (Strix occidentalis occidentalis). Regurgitated pellets were collected at roost and nest sites between 1,000 and 7,600 ft elevation in the Sierra National Forest and were examined for remnant bones, feathers, and insect exoskeletons....

Trajectories of Internalizing Problems in War-Affected Sierra Leonean Youth: Examining Conflict and Postconflict Factors

ERIC Educational Resources Information Center

Betancourt, Theresa S.; McBain, Ryan; Newnham, Elizabeth A.; Brennan, Robert T.

2013-01-01

Three waves of data from a prospective longitudinal study in Sierra Leone were used to examine internalizing trajectories in 529 war-affected youth (ages 10-17 at baseline; 25% female). Latent class growth analyses identified 4 trajectories: A large majority of youth maintained lower levels of internalizing problems (41.4%) or significantly…

Socio-Ecological Factors Affecting Pregnant Women's Anemia Status in Freetown, Sierra Leone

ERIC Educational Resources Information Center

M'Cormack, Fredanna; Drolet, Judy

2012-01-01

Background: Sierra Leone has high maternal mortality. Socio-ecological factors are considered contributing factors to this high mortality. Anemia is considered to be a direct cause of 4% of maternal deaths and an indirect cause of 20-40% of maternal deaths. Purpose: The current study explores socio-ecological contributing factors to the anemia…

Stability and change in minerotrophic peatlands, Sierra Nevada of California and Nevada

Treesearch

James W. Bartolome; Don C. Erman; Charles F. Schwara

1990-01-01

Minerotrophic peatlands or fens in California's Sierra Nevada are small wet meadows surrounded by mixed conifer forest. The dynamics of vegetation change at the meadow edge and the ages and development of fens were investigated, in the Sagehen Creek Basin near Truckee, California, through the use of radiocarbon dating of peat, pollen studies, examination of...

The Violence of Peace and the Role of Education: Insights from Sierra Leone

ERIC Educational Resources Information Center

Novelli, Mario; Higgins, Sean

2017-01-01

Research on peacebuilding has mushroomed over the last decade and there is a growing interest in the role of education in supporting peacebuilding processes. This paper engages with these debates, UN peacebuilding activities and the location of education initiatives therein, through a case study of Sierra Leone. In the first part, we explore the…

School Persistence in the Wake of War: Wartime Experiences, Reintegration Supports, and Dropout in Sierra Leone

ERIC Educational Resources Information Center

Zuilkowski, Stephanie Simmons; Betancourt, Theresa S.

2014-01-01

This article examines the relationship of wartime experience and reintegration supports to students' risk of school dropout. It draws on longitudinal, mixed-methods data collected among children and youth in Sierra Leone from 2002 through 2008. The study finds that family financial support and perceived social support are positively associated…

Nutrient fluxes in forests of the eastern Sierra Nevada: comparisons with humid forest systems

Treesearch

Dale W. Johnson; Richard B. Susfalk; Randy A. Dahlgreen; Virginia Boucher; Andrzej Bytnerowicz

1998-01-01

Preliminary results of studies on nutrient fluxes in forests of the eastern Sierra Nevada were compared to those from more humid and polluted ecosystems. Snowmelt, soil solution, soil, and streamwater were collected from Jeffrey and lodgepole pine (Pinus jeffreyii [Grev. and Balf.] and Pinus contorta Dougl.) stands in Little Valley...

Silviculture-ecology of forest-zone hardwoods in the Sierra Nevada

Treesearch

Philip M. McDonald; John C. Tappeiner

1996-01-01

Although the principal hardwood species in the forest zone of the Sierra Nevada (California black oak, tanoak, Pacific madrone, and canyon live oak) are key components of many ecosystems, they have received comparatively little study. Currently they are underutilized and unmanaged. This paper brings together what is known on the silviculture-ecology of these species...

Nesting habitat of Warbling Vireos across an elevational gradient in the southern Sierra Nevada

Treesearch

Kathryn Purcell

2007-01-01

Populations of Warbling Vireos (Vireo gilvus) are declining in California, apparently due to low reproductive success. From 1989—2002, I studied the nest-site selection and reproductive success ofWarbling Vireos across an elevational gradient in the southern Sierra Nevada. Warbling Vireos regularly nested in upland coniferous forests with...

SURVEY OF LIBRARY PERSONNEL IN SIERRA COLLEGE EMPLOYMENT AREA.

ERIC Educational Resources Information Center

YOUNG, ELMA L.

FOR TWO YEARS PRIOR TO THIS STUDY, SIERRA COLLEGE, CALIFORNIA, HAD OFFERED LIBRARY TECHNICIAN TRAINING IN ITS EVENING PROGRAM. A SURVEY OF LIBRARIES IN THE 5-COUNTY EMPLOYMENT AREA OF THE COLLEGE'S GRADUATES WAS MADE IN 1968 TO DETERMINE NEEDS FOR LIBRARY TECHNICIANS. IN THE FIVE COUNTIES, 167 LIBRARIES WERE IDENTIFIED, WITH A TOTAL OF 1084…

Photo series for quantifying forest fuels in Mexico: montane subtropical forests of the Sierra Madre del Sur and temperate forests and montane shrubland of the northern Sierra Madre Oriental

Treesearch

Jorge E. Morfin-Rios; Ernesto Alvarado-Celestino; Enrique J. Jardel-Pelaez; Robert E. Vihnanek; David K. Wright; Jose M. Michel-Fuentes; Clinton S. Wright; Roger D. Ottmar; David V. Sandberg; Andres Najera-Diaz

2008-01-01

Single wide-angle and stereo photographs display a range of forest ecosystems conditions and fuel loadings in montane subtropical forests of the Sierra Madre del Sur and temperate forests and montane shrubland of the northern Sierra Madre Oriental of Mexico. Each group of photographs includes inventory information summarizing overstory vegetation composition and...

Ground-Water Flow Model of the Sierra Vista Subwatershed and Sonoran Portions of the Upper San Pedro Basin, Southeastern Arizona, United States, and Northern Sonora, Mexico

USGS Publications Warehouse

Pool, D.R.; Dickinson, Jesse

2007-01-01

A numerical ground-water model was developed to simulate seasonal and long-term variations in ground-water flow in the Sierra Vista subwatershed, Arizona, United States, and Sonora, Mexico, portions of the Upper San Pedro Basin. This model includes the simulation of details of the groundwater flow system that were not simulated by previous models, such as ground-water flow in the sedimentary rocks that surround and underlie the alluvial basin deposits, withdrawals for dewatering purposes at the Tombstone mine, discharge to springs in the Huachuca Mountains, thick low-permeability intervals of silt and clay that separate the ground-water flow system into deep-confined and shallow-unconfined systems, ephemeral-channel recharge, and seasonal variations in ground-water discharge by wells and evapotranspiration. Steady-state and transient conditions during 1902-2003 were simulated by using a five-layer numerical ground- water flow model representing multiple hydrogeologic units. Hydraulic properties of model layers, streamflow, and evapotranspiration rates were estimated as part of the calibration process by using observed water levels, vertical hydraulic gradients, streamflow, and estimated evapotranspiration rates as constraints. Simulations approximate observed water-level trends throughout most of the model area and streamflow trends at the Charleston streamflow-gaging station on the San Pedro River. Differences in observed and simulated water levels, streamflow, and evapotranspiration could be reduced through simulation of climate-related variations in recharge rates and recharge from flood-flow infiltration.

Scaling up family planning in Sierra Leone: A prospective cost-benefit analysis.

PubMed

Keen, Sarah; Begum, Hashina; Friedman, Howard S; James, Chris D

2017-12-01

Family planning is commonly regarded as a highly cost-effective health intervention with wider social and economic benefits. Yet use of family planning services in Sierra Leone is currently low and 25.0% of married women have an unmet need for contraception. This study aims to estimate the costs and benefits of scaling up family planning in Sierra Leone. Using the OneHealth Tool, two scenarios of scaling up family planning coverage to currently married women in Sierra Leone over 2013-2035 were assessed and compared to a 'no-change' counterfactual. Our costing included direct costs of drugs, supplies and personnel time, programme costs and a share of health facility overhead costs. To monetise the benefits, we projected the cost savings of the government providing five essential social services - primary education, child immunisation, malaria prevention, maternal health services and improved drinking water - in the scale-up scenarios compared to the counterfactual. The total population, estimated at 6.1 million in 2013, is projected to reach 8.3 million by 2035 in the high scenario compared to a counterfactual of 9.6 million. We estimate that by 2035, there will be 1400 fewer maternal deaths and 700 fewer infant deaths in the high scenario compared to the counterfactual. Our modelling suggests that total costs of the family planning programme in Sierra Leone will increase from US$4.2 million in 2013 to US$10.6 million a year by 2035 in the high scenario. For every dollar spent on family planning, Sierra Leone is estimated to save US$2.10 in expenditure on the five selected social sector services over the period. There is a strong investment case for scaling up family planning services in Sierra Leone. The ambitious scale-up scenarios have historical precedent in other sub-Saharan African countries, but the extent to which they will be achieved depends on a commitment from both the government and donors to strengthening Sierra Leone's health system post-Ebola.

Evaluating the utility of detrital thermochronometric studies: detrital laser ablation (U-Th)/He dating and conventional bedrock zircon (U-Th)/He analyses from the eastern Sierra Nevada, California

NASA Astrophysics Data System (ADS)

Horne, A.; Hodges, K. V.; Van Soest, M. C.

2016-12-01

Recent applications of the newly developed `laser ablation double dating' (LADD) technique, an integrated laser microprobe U/Pb and (U-Th)/He dating method, have showcased the potential utility of LADD for detrital thermochronologic studies. However, detrital thermochronologic techniques rely on confidence that detrital data adequately represent the full range of bedrock cooling ages within a catchment. To test this primary assumption, we compare (U-Th)/He zircon ages from age-elevation transects to LADD (U-Th)/He zircon ages from modern fluvial detritus collected at the range front in the eastern Sierra Nevada, California. Terminated by a normal fault escarpment, the small, steep catchments along the eastern side of the Sierra Nevada batholith are apropos locations for comparing the ability of detrital data to deduce the exhumation history of a source terrain with standard age-elevation transects. Additionally, the exhumation of the Sierra Nevada batholith is also intriguing, as past evaluations of the post-emplacement exhumation history of the range have yielded discrepant results. Thus far, analyses from the southern extent of the eastern Sierra Nevada show narrow ranges of cooling ages consistent with simple, relatively rapid exhumation. Ongoing analyses will expand the dataset such that we can fully compare bedrock and detrital age ranges as well as characterize the exhumation history of the range with a thermochronometer that has not been used to date the batholith.

Introduction to the special issue on Sierran mixed-conifer research

Treesearch

Malcolm North; Jiquan Chen

2005-01-01

Like much of the western United States, California’s forest has been severely altered by a century of fire suppression. The Sierra Nevada’s largest forest type, mixed conifer, which is primary habitat for more vertebrate species than any other Californian forest community, historically burned every 12–17 years. In 1894, John Muir wrote "The inviting openness of...

Airborne and ground-based measurements of the trace gases and particles emitted by prescribed fires in the United States

Treesearch

I. R. Burling; R. J. Yokelson; S. K. Akagi; Shawn Urbanski; Cyle Wold; D. W. T. Griffith; T. J. Johnson; J. Reardon; D. R. Weise

2011-01-01

We measured the emission factors for 19 trace gas species and particulate matter (PM2.5) from 14 prescribed fires in chaparral and oak savanna in the southwestern US, as well as conifer forest understory in the southeastern US and Sierra Nevada 5 mountains of California. These are likely the most extensive emission factor field measurements for temperate biomass...

Contrasting impacts of climate and competition on large sugar pine growth and defense in a fire-excluded forest of the Central Sierra Nevada

Treesearch

Andrew Slack; Jeffrey Kane; Eric Knapp; Rosemary Sherriff

2017-01-01

Many forest ecosystems with a large pine component in the western United States have experienced environmental stress associated with climate change and increased competition with forest densification in the absence of fire. Information on how changes in climate and competition affect carbon allocation to tree growth and defense is needed to anticipate changes to tree...

Tectonic evolution of the Neoproterozoic Tandilia sedimentary cover, Argentina: New evidence of contraction and extensional events in the southwest Gondwana margin

NASA Astrophysics Data System (ADS)

Hernández, Mariano; Arrouy, María Julia; Scivetti, Nicolás; Franzese, Juan R.; Canalicchio, José M.; Poiré, Daniel G.

2017-11-01

At the northwestern portion of the Tandilia System, a detailed structural analysis on the Precambrian sedimentary units exposed in the quarries of the Olavarría-Sierras Bayas area was carried out. These units exhibit deformational structures of several scales, from centimeters to hundreds of meters. The hundreds of meters scale involves E-W- and NW-SE-trending normal faults and NW-SE- and NE-SW-trending contractional folds. The centimeters to meters scale involves veins, joints, normal faults, shear fractures and stylolites, with a prevailing ∼ E-W to NW-SE trend. All these structures were formed by two major tectonic events. The first was the folding event at ∼580 Ma, with NNE-SSW to NE-SW and NW-SE direction of contraction. The second was the extensional faulting event, given by the widespread NNE-SSW-directed extension event during the Atlantic Ocean opening (Jurassic-Cretaceous). Both major events would have been controlled by the reactivation of basement anisotropies. These major tectonic events controlled the deformation of the Precambrian sedimentary cover of the Tandilia system, leading to an economically important aspect in the mining development of the Olavarría-Sierras Bayas area.

The application of ERTS imagery to mapping snow cover in the western United States. [Salt Verde in Arizona and Sierra Nevada California

NASA Technical Reports Server (NTRS)

Barnes, J. C. (Principal Investigator); Bowley, C. J.; Simmes, D. A.

1974-01-01

The author has identified the following significant results. In much of the western United States a large part of the utilized water comes from accumulated mountain snowpacks; thus, accurate measurements of snow distributions are required for input to streamflow prediction models. The application of ERTS-1 imagery for mapping snow has been evaluated for two geographic areas, the Salt-Verde watershed in central Arizona and the southern Sierra Nevada in California. Techniques have been developed to identify snow and to differentiate between snow and cloud. The snow extent for these two drainage areas has been mapped from the MSS-5 (0.6 - 0.7 microns) imagery and compared with aerial survey snow charts, aircraft photography, and ground-based snow measurements. The results indicate that ERTS imagery has substantial practical applications for snow mapping. Snow extent can be mapped from ERTS-1 imagery in more detail than is depicted on aerial survey snow charts. Moreover, in Arizona and southern California cloud obscuration does not appear to be a serious deterrent to the use of satellite data for snow survey. The costs involved in deriving snow maps from ERTS-1 imagery appear to be very reasonable in comparison with existing data collection methods.

Subsurface geology of the late Tertiary and Quaternary water-bearing deposits of the southern part of the San Joaquin Valley, California

USGS Publications Warehouse

Croft, M.G.

1972-01-01

The study area, which includes about 5,000 square miles of the southern part of the San Joaquin Valley, is a broad structural trough of mostly interior drainage. The Sierra Nevada on the east is composed of consolidated igneous and metamorphic rocks of pre-Tertiary age. The surface of these rocks slopes 4?-6? southwestward from the foothills and underlies the valley. The Coast Ranges on the west consist mostly of complexly folded and faulted consolidated marine and nonmarine sedimentary rocks of Jurassic, Cretaceous, and Tertiary age, which dip eastward and overlie the basement complex. Unconsolidated deposits, of late Pliocene to Holocene age, blanket the underlying consolidated rocks in the valley and are the source of most of the fresh ground water. The unconsolidated deposits, the subject of this report, are divided into informal stratigraphic units on the basis of source of sediment, environment of deposition, and texture. Flood-basin, lacustrine, and marsh deposits are fine grained and underlie the valley trough. They range in age from late Pliocene to Holocene. These deposits, consisting of nearly impermeable gypsiferous fine sand, silt, and clay, are more than 3,000 feet thick beneath parts of Tulare Lake bed. In other parts of the trough, flood-basin, lacustrine, and marsh deposits branch into clayey or silty clay tongues designated by the letter symbols A to F. Three of these tongues, the E, C, and A clays, lie beneath large areas of the southern part of the valley. The E clay includes the Corcoran Clay Member of the Tulare Formation, the most extensive hydrologic confining layer in the valley. The E clay underlies about 3,500 square miles of bottom land and western slopes. The beds generally are dark-greenish-gray mostly diatomaceous silty clay of Pleistocene age. Marginally, the unit bifurcates into an upper and a lower stratum that contains thin beds of moderately yellowish-brown silt and sand. The E clay is warped into broad, gentle northwesterly trending anticlines and synclines. The C clay, of Pleistocene age, is a fine-grained lacustrine or paludal deposit occurring 220-300 feet beneath Tulare Lake bed and parts of Fresno Slough. The beds consist of bluish-gray silty clay. Structural contours indicate that the C clay has been extensively warped and folded. The A clay of Pleistocene and Holocene (?) age is a fine-grained lacustrine or paludal deposit occurring 10-60 feet beneath Buena Vista, Kern, and Tulare Lake beds, and parts of Fresno Slough. The clay is mainly blue or dark greenish gray, plastic, and highly organic. In some areas the unit is separated into an upper and a lower stratum by several feet of sand. A radiocarbon date of 26,780 ? 600 years was obtained from wood cored 3 feet beneath the clay. Continental deposits are arkosic beds of late Pliocene and Pleistocene (?) age and were derived from the Sierra Nevada, Tehachapi, and San Emigdio Mountains. In places, a reduced-oxidized contact transgresses the deposits derived from the Sierra Nevada. The reduced deposits consist of moderately permeable bluish-green or bluish-gray fine to medium sand, silt, and clay. The oxidized deposits consist mainly of poorly permeable yellowish-brown silt and fine sand. Deposits derived from the Tehachapi and the San Emigdio Mountains consist of poorly to moderately permeable yellowish-brown sand and silt. Continental and alluvial deposits of Tertiary and Quaternary age that were derived from the Coast Ranges consist mainly of poorly to moderately permeable yellowish-brown gravel, sand, silt, and clay. They include the Tulare Formation and overlying alluvial deposits. Alluvium is composed of coarse arkosic deposits derived from the Sierra Nevada, Tehachapi, and San Emigdio Mountains. A reduced-oxidized contact also transgresses the alluvial deposits derived from the Sierra Nevada. The oxidized deposits consist of poorly to highly permeable yellowish-brown gravel, sand, silt, and clay. The reduc

Groundwater quality in the Indian Wells Valley, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

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. Indian Wells Valley is one of the study areas being evaluated. The Indian Wells study area is approximately 600 square miles (1,554 square kilometers) and includes the Indian Wells Valley groundwater basin (California Department of Water Resources, 2003). Indian Wells Valley has an arid climate and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). The study area has internal drainage, with runoff from the surrounding mountains draining towards dry lake beds in the lower parts of the valley. Land use in the study area is approximately 97.0 percent (%) natural, 0.4% agricultural, and 2.6% urban. The primary natural land cover is shrubland. The largest urban area is the city of Ridgecrest (2010 population of 28,000). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from the Sierra Nevada to the west and from the other surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada and to the west and from the other surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada and direct infiltration from irrigation and septic systems. The primary sources of discharge are pumping wells and evapotranspiration near the dry lakebeds. The primary aquifers in the Indian Wells study area are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Indian Wells Valley are completed to depths between 240 and 800 feet (73 to 244 meters), consist of solid casing from the land surface to a depth of 180 to 260 feet (55 to 79 meters), and are screened or perforated below the solid casing.

Predictions of fire behavior and resistance to control: for use with photo series for the sierra mixed conifer type and the sierra true fir type.

Treesearch

Franklin R. Ward; David V. Sandberg

1981-01-01

This publication presents tables on the behavior of fire and the resistance: of fuels to control. The information is to be used with the photos in the publication, "Photo Series for Quantifying Forest Residues in the Sierra Mixed Conifer Type, Sierra True Fir Type" (Maxwell, Wayne G.; Ward, Franklin R. 1979. Gen. Tech. Rep. PNW-GTR-095. Portland, OR: U.S....

Superposition of tectonic structures leading elongated intramontane basin: the Alhabia basin (Internal Zones, Betic Cordillera)

NASA Astrophysics Data System (ADS)

Martínez-Martos, Manuel; Galindo-Zaldivar, Jesús; Martínez-Moreno, Francisco José; Calvo-Rayo, Raquel; Sanz de Galdeano, Carlos

2017-10-01

The relief of the Betic Cordillera was formed since the late Serravallian inducing the development of intramontane basins. The Alhabia basin, situated in the central part of the Internal Zones, is located at the intersection of the Alpujarran Corridor, the Tabernas basin, both trending E-W, and the NW-SE oriented Gádor-Almería basin. The geometry of the basin has been constrained by new gravity data. The basin is limited to the North by the Sierra de Filabres and Sierra Nevada antiforms that started to develop in Serravallian times under N-S shortening and to the south by Sierra Alhamilla and Sierra de Gádor antiforms. Plate convergence in the region rotated counter-clockwise in Tortonian times favouring the formation of E-W dextral faults. In this setting, NE-SW extension, orthogonal to the shortening direction, was accommodated by normal faults on the SW edge of Sierra Alhamilla. The Alhabia basin shows a cross-shaped depocentre in the zone of synform and fault intersection. This field example serves to constrain recent counter-clockwise stress rotation during the latest stages of Neogene-Quaternary basin evolution in the Betic Cordillera Internal Zones and underlines the importance of studying the basins' deep structure and its relation with the tectonic structures interactions.

Implementing an Ebola Vaccine Study - Sierra Leone.

PubMed

Widdowson, Marc-Alain; Schrag, Stephanie J; Carter, Rosalind J; Carr, Wendy; Legardy-Williams, Jennifer; Gibson, Laura; Lisk, Durodami R; Jalloh, Mohamed I; Bash-Taqi, Donald A; Kargbo, Samuel A Sheku; Idriss, Ayesha; Deen, Gibrilla F; Russell, James B W; McDonald, Wendi; Albert, Alison P; Basket, Michelle; Callis, Amy; Carter, Victoria M; Ogunsanya, Kelli R Clifton; Gee, Julianne; Pinner, Robert; Mahon, Barbara E; Goldstein, Susan T; Seward, Jane F; Samai, Mohamed; Schuchat, Anne

2016-07-08

In October 2014, the College of Medicine and Allied Health Sciences of the University of Sierra Leone, the Sierra Leone Ministry of Health and Sanitation, and CDC joined the global effort to accelerate assessment and availability of candidate Ebola vaccines and began planning for the Sierra Leone Trial to Introduce a Vaccine against Ebola (STRIVE). STRIVE was an individually randomized controlled phase II/III trial to evaluate efficacy, immunogenicity, and safety of the recombinant vesicular stomatitis virus Ebola vaccine (rVSV-ZEBOV). The study population was health care and frontline workers in select chiefdoms of the five most affected districts in Sierra Leone. Participants were randomized to receive a single intramuscular dose of rVSV-ZEBOV at enrollment or to receive a single intramuscular dose 18-24 weeks after enrollment. All participants were followed up monthly until 6 months after vaccination. Two substudies separately assessed detailed reactogenicity over 1 month and immunogenicity over 12 months. During the 5 months before the trial, STRIVE and partners built a research platform in Sierra Leone comprising participant follow-up sites, cold chain, reliable power supply, and vaccination clinics and hired and trained at least 350 national staff. Wide-ranging community outreach, informational sessions, and messaging were conducted before and during the trial to ensure full communication to the population of the study area regarding procedures and current knowledge about the trial vaccine. During April 9-August 15, 2015, STRIVE enrolled 8,673 participants, of whom 453 and 539 were also enrolled in the safety and immunogenicity substudies, respectively. As of April 28, 2016, no Ebola cases and no vaccine-related serious adverse events, which by regulatory definition include death, life-threatening illness, hospitalization or prolongation of hospitalization, or permanent disability, were reported in the study population. Although STRIVE will not produce an estimate of vaccine efficacy because of low case frequency as the epidemic was controlled, data on safety and immunogenicity will support decisions on licensure of rVSV-ZEBOV.The activities summarized in this report would not have been possible without collaboration with many U.S. and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html).

Quantifying surgical capacity in Sierra Leone: a guide for improving surgical care.

PubMed

Kingham, T Peter; Kamara, Thaim B; Cherian, Meena N; Gosselin, Richard A; Simkins, Meghan; Meissner, Chris; Foray-Rahall, Lynda; Daoh, Kisito S; Kabia, Soccoh A; Kushner, Adam L

2009-02-01

Lack of access to surgical care is a public health crisis in developing countries. There are few data that describe a nation's ability to provide surgical care. This study combines information quantifying the infrastructure, human resources, interventions (ie, procedures), emergency equipment and supplies for resuscitation, and surgical procedures offered at many government hospitals in Sierra Leone. Site visits were performed in 2008 at 10 of the 17 government civilian hospitals in Sierra Leone. The World Health Organization's Tool for Situational Analysis to Assess Emergency and Essential Surgical Care was used to assess surgical capacity. There was a paucity of electricity, running water, oxygen, and fuel at the government hospitals in Sierra Leone. There were only 10 Sierra Leonean surgeons practicing in the surveyed government hospitals. Many procedures performed at most of the hospitals were cesarean sections, hernia repairs, and appendectomies. There were few supplies at any of the hospitals, forcing patients to provide their own. There was a disparity between conditions at the government hospitals and those at the private and mission hospitals. There are severe shortages in all aspects of infrastructure, personnel, and supplies required for delivering surgical care in Sierra Leone. While it will be difficult to improve the infrastructure of government hospitals, training additional personnel to deliver safe surgical care is possible. The situational analysis tool is a valuable mechanism to quantify a nation's surgical capacity. It provides the background data that have been lacking in the discussion of surgery as a public health problem and will assist in gauging the effectiveness of interventions to improve surgical infrastructure and care.

Macroeconomic costs of the unmet burden of surgical disease in Sierra Leone: a retrospective economic analysis

PubMed Central

Kamara, Thaim B; Lavy, Christopher B D; Leather, Andy J M; Bolkan, Håkon A

2018-01-01

Objectives The Lancet Commission on Global Surgery estimated that low/middle-income countries will lose an estimated cumulative loss of US$12.3 trillion from gross domestic product (GDP) due to the unmet burden of surgical disease. However, no country-specific data currently exist. We aimed to estimate the costs to the Sierra Leone economy from death and disability which may have been averted by surgical care. Design We used estimates of total, met and unmet need from two main sources—a cluster randomised, cross-sectional, countrywide survey and a retrospective, nationwide study on surgery in Sierra Leone. We calculated estimated disability-adjusted life years from morbidity and mortality for the estimated unmet burden and modelled the likely economic impact using three different methods—gross national income per capita, lifetime earnings foregone and value of a statistical life. Results In 2012, estimated, discounted lifetime losses to the Sierra Leone economy from the unmet burden of surgical disease was between US$1.1 and US$3.8 billion, depending on the economic method used. These lifetime losses equate to between 23% and 100% of the annual GDP for Sierra Leone. 80% of economic losses were due to mortality. The incremental losses averted by scale up of surgical provision to the Lancet Commission target of 80% were calculated to be between US$360 million and US$2.9 billion. Conclusion There is a large economic loss from the unmet need for surgical care in Sierra Leone. There is an immediate need for massive investment to counteract ongoing economic losses. PMID:29540407

Stratigraphy and Mesozoic–Cenozoic tectonic history of northern Sierra Los Ajos and adjacent areas, Sonora, Mexico

USGS Publications Warehouse

Page, William R.; Gray, Floyd; Iriondo, Alexander; Miggins, Daniel P.; Blodgett, Robert B.; Maldonado, Florian; Miller, Robert J.

2010-01-01

Geologic mapping in the northern Sierra Los Ajos reveals new stratigraphic and structural data relevant to deciphering the Mesozoic–Cenozoic tectonic evolution of the range. The northern Sierra Los Ajos is cored by Proterozoic, Cambrian, Devonian, Mississippian, and Pennsylvanian strata, equivalent respectively to the Pinal Schist, Bolsa Quartzite and Abrigo Limestone, Martin Formation, Escabrosa Limestone, and Horquilla Limestone. The Proterozoic–Paleozoic sequence is mantled by Upper Cretaceous rocks partly equivalent to the Fort Crittenden and Salero Formations in Arizona, and the Cabullona Group in Sonora, Mexico.Absence of the Upper Jurassic–Lower Cretaceous Bisbee Group below the Upper Cretaceous rocks and above the Proterozoic–Paleozoic rocks indicates that the Sierra Los Ajos was part of the Cananea high, a topographic highland during the Late Jurassic and Early Cretaceous. Deposition of Upper Cretaceous rocks directly on Paleozoic and Proterozoic rocks indicates that the Sierra Los Ajos area had subsided as part of the Laramide Cabullona basin during Late Cretaceous time. Basal beds of the Upper Cretaceous sequence are clast-supported conglomerate composed locally of basement (Paleozoic) clasts. The conglomerate represents erosion of Paleozoic basement in the Sierra Los Ajos area coincident with development of the Cabullona basin.The present-day Sierra Los Ajos reaches elevations of greater than 2600 m, and was uplifted during Tertiary basin-and-range extension. Upper Cretaceous rocks are exposed at higher elevations in the northern Sierra Los Ajos and represent an uplifted part of the inverted Cabullona basin. Tertiary uplift of the Sierra Los Ajos was largely accommodated by vertical movement along the north-to-northwest-striking Sierra Los Ajos fault zone flanking the west side of the range. This fault zone structurally controls the configuration of the headwaters of the San Pedro River basin, an important bi-national water resource in the US-Mexico border region.

A new species of Cryptotis (Mammalia, Eulipotyphla, Soricidae) from the Sierra de Perijá, Venezuelan-Colombian Andes

USGS Publications Warehouse

Quiroga-Carmona, Marcial; Woodman, Neal

2015-01-01

The Sierra de Perijá is the northern extension of the Cordillera Oriental of the Andes and includes part of the border between Colombia and Venezuela. The population of small-eared shrews (Mammalia, Eulipotyphla, Soricidae, Cryptotis) inhabiting the Sierra de Perijá previously was known from only a single skull from an individual collected in Colombia in 1989. This specimen had been referred to alternatively as C. thomasi and C. meridensis, but more precise definition of the known Colombian and Venezuelan species of Cryptotis has since excluded the Sierra de Perijá population from any named species. The recent collection of a specimen from the Venezuelan slope of Sierra de Perijá, prompted us to re-evaluate the taxonomic status of this population and determine its relationship with other Andean shrews. Our examination of the available specimens revealed that they possess a unique suite of morphological and morphometrical characters, and we describe the Sierra de Perijá population as a new species in the South American C. thomasi species group. Recognition of this new species adds to our knowledge of this genus in South America and to the biodiversity of the Sierra de Perijá.

Thermal and hydrologic attributes of rock glaciers and periglacial talus landforms: Sierra Nevada, California, USA

Treesearch

Constance I. Millar; Robert D. Westfall; Diane L. Delany

2013-01-01

To explore thermal regimes and hydrologic capacity of rock glaciers and related periglacial talus landforms, mini-thermochrons were deployed in and around potentially ice-embedded features of the Sierra Nevada. Results from pilot studies at 13 rock glaciers and 7 taluses indicate that outlet springs from these landforms generally do not desiccate but persist year...

Developing and managing sustainable forest ecosystems for spotted owls in the Sierra Nevada

Treesearch

J. Verner; K.S. McKelvey

1994-01-01

Studies of the California spotted owl have revealed significant selection for habitats with large, old trees; relatively high basal areas of snags; and relatively high biomass in large, downed logs. Based on planning documents for national forests in the Sierra Nevada, we projected declining amounts of older-forest attributes. Region 5 has adopted measures to retain...

Fire weather and large fire potential in the northern Sierra Nevada

Treesearch

Brandon M. Collins

2014-01-01

Fuels, weather, and topography all contribute to observed fire behavior. Of these, weather is not only the most dynamic factor, it is the most likely to be directly influenced by climate change. In this study 40 years of daily fire weather observations from five weather stations across the northern Sierra Nevada were analyzed to investigate potential changes or trends...

Rural-Urban Migration in Sierra Leone: Determinants and Policy Implications. African Rural Economy Paper No. 13.

ERIC Educational Resources Information Center

Byerlee, Derek; And Others

Study objectives were to: increase the understanding of rural to urban migration processes in Africa and Sierra Leone; develop and test a theoretical schema and survey methodology for migration research; and evaluate the effects of policy on migration. The migration survey was conducted in rural areas, urban areas, and again in the rural areas…

Response of Brown Creepers to elevation and forest edges in the southern Sierra Nevada, California

Treesearch

Kathryn Purcell; Craig Thompson; Douglas Drynan

2012-01-01

We studied the responses of the Brown Creeper (Certhia americana) to forest edges in the southern Sierra Nevada, California. We censused birds and monitored nests in four forest types over an elevational gradient. We identified habitat patches homogeneous in terms of forest type, seral stage, and canopy cover and rated edges between adjoining...

Snowmelt runoff and water yield along elevation and temperature gradients in California's southern Sierra Nevada

Treesearch

Carolyn T. Hunsaker; Thomas W. Whitaker; Roger C. Bales

2012-01-01

Differences in hydrologic response across the rain-snow transition in the southern Sierra Nevada were studied in eight headwater catchments – the Kings River Experimental Watersheds – using continuous precipitation, snowpack, and streamflow measurements. The annual runoff ratio (discharge divided by precipitation) increased about 0.1 per 300 m of mean catchment...

76 FR 16689 - Standard Instrument Approach Procedures, and Takeoff Minimums and Obstacle Departure Procedures...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-25

..., Raton Muni/Crews Field, RNAV (GPS) RWY 25, Orig Ruidoso, NM, Sierra Blanca Rgnl, CAPITAN ONE Graphic DP Ruidoso, NM, Sierra Blanca Rgnl, GPS RWY 24, Orig-A, CANCELLED Ruidoso, NM, Sierra Blanca Rgnl, RNAV (GPS...

Exhaustion: The African Way of War

DTIC Science & Technology

2014-04-23

Agony of a Nation (Freetown, Sierra Leone: Andromeda Publications, 1996), 144. 150Dorman, Blair’s Successful War, 119. 151Keen, Conflict and...Cases. Westport, CT: Praeger, 2002. Koroma, Abdul K. Sierra Leone: The Agony of a Nation. Freetown. Sierra Leone: Andromeda Publications, 1996

NASA Deputy Administrator Tours Sierra Nevada Space Systems' Dre

NASA Image and Video Library

2011-02-05

Director of Advanced Programs, Sierra Nevada Corporation, Jim Voss talks during a press conference with Sierra Nevada's Dream Chaser spacecraft in the background on Saturday, Feb. 5, 2011, at the University of Colorado at Boulder. Sierra Nevada's Dream Chaser spacecraft is under development with support from NASA's Commercial Crew Development Program to provide crew transportation to and from low Earth orbit. NASA is helping private companies develop innovative technologies to ensure that the U.S. remains competitive in future space endeavors. Photo Credit: (NASA/Bill Ingalls)

NASA Deputy Administrator Tours Sierra Nevada Space Systems' Dre

NASA Image and Video Library

2011-02-05

Sierra Nevada Space Systems chairman Mark Sirangello talks during a press conference with Sierra Nevada's Dream Chaser spacecraft in the background on Saturday, Feb. 5, 2011, at the University of Colorado at Boulder. Sierra Nevada's Dream Chaser spacecraft is under development with support from NASA's Commercial Crew Development Program to provide crew transportation to and from low Earth orbit. NASA is helping private companies develop innovative technologies to ensure that the U.S. remains competitive in future space endeavors. Photo Credit: (NASA/Bill Ingalls)

76 FR 44535 - Revisions to the California State Implementation Plan, Northern Sierra Air Quality Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-26

... the California State Implementation Plan, Northern Sierra Air Quality Management District, Sacramento Metropolitan Air Quality Management District, and South Coast Air Quality Management District AGENCY... the Northern Sierra Air Quality Management District (NSAQMD), Sacramento Metropolitan Air Quality...

77 FR 23192 - Revisions to the California State Implementation Plan, Northern Sierra and Sacramento...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-18

... proposing to approve revisions to the Northern Sierra Air Quality Management District (NSAQMD) and Sacramento Metropolitan Air Quality Management District (SMAQMD) portions of the California State... the California State Implementation Plan, Northern Sierra and Sacramento Metropolitan Air Quality...

76 FR 44493 - Revisions to the California State Implementation Plan, Northern Sierra Air Quality Management...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-26

... California State Implementation Plan, Northern Sierra Air Quality Management District, Sacramento Metropolitan Air Quality Management District, and South Coast Air Quality Management District AGENCY... approve revisions to the Northern Sierra Air Quality Management District (NSAQMD), Sacramento Metropolitan...

An ecologic study comparing distribution of Pasteurella trehalosi and Mannheimia haemolytica between Sierra Nevada bighorn sheep, White Mountain bighorn sheep, and domestic sheep.

PubMed

Tomassini, Letizia; Gonzales, Ben; Weiser, Glen C; Sischo, William

2009-10-01

The prevalence and phenotypic variability of Pasteurella and Mannheimia isolates from Sierra Nevada bighorn sheep (Ovis canadensis sierrae), White Mountain bighorn sheep (Ovis canadensis nelsoni), and domestic sheep (Ovis aries) from California, USA, were compared. The White Mountain bighorn sheep population had a recent history of pneumonia-associated mortality, whereas the Sierra Nevada bighorn sheep population had no recent history of pneumonia-associated mortality. The domestic sheep flocks were pastured in areas geographically near both populations but were not known to have direct contact with either bighorn sheep population. Oropharyngeal swab samples were collected from healthy domestic and bighorn sheep and cultured to characterize bacterial species, hemolysis, biogroups, and biovariants. Pasteurella trehalosi and Mannheimia haemolytica were detected in all of the study populations, but the relative proportion of each bacterial species differed among sheep populations. Pasteurella trehalosi was more common than M. haemolytica in the bighorn sheep populations, whereas the opposite was true in domestic sheep. Mannheimia haemolytica was separated into 11 biogroups, and P. trehalosi was characterized into two biogroups. Biogroup distributions for M. haemolytica and P. trehalosi differed among the three populations; however, no difference was detected for the distribution of P. trehalosi biogroups between the Sierra Nevada bighorn sheep and domestic sheep. The prevalence odds ratios (pOR) for the distribution of M. haemolytica biogroups suggested little difference between White Mountain bighorn sheep and domestic sheep compared with Sierra Nevada bighorn sheep and domestic sheep, although these comparisons had relatively large confidence intervals for the point estimates. Hemolytic activity of the isolates was not different among the sheep populations for M. haemolytica but was different for P. trehalosi. No clear evidence of association was found in the Pasteurellaceae distribution between the White Mountains bighorn sheep and domestic sheep.

Evaluation of the benefits and risks of introducing Ebola community care centers, Sierra Leone.

PubMed

Kucharski, Adam J; Camacho, Anton; Checchi, Francesco; Waldman, Ron; Grais, Rebecca F; Cabrol, Jean-Clement; Briand, Sylvie; Baguelin, Marc; Flasche, Stefan; Funk, Sebastian; Edmunds, W John

2015-03-01

In some parts of western Africa, Ebola treatment centers (ETCs) have reached capacity. Unless capacity is rapidly scaled up, the chance to avoid a generalized Ebola epidemic will soon diminish. The World Health Organization and partners are considering additional Ebola patient care options, including community care centers (CCCs), small, lightly staffed units that could be used to isolate patients outside the home and get them into care sooner than otherwise possible. Using a transmission model, we evaluated the benefits and risks of introducing CCCs into Sierra Leone's Western Area, where most ETCs are at capacity. We found that use of CCCs could lead to a decline in cases, even if virus transmission occurs between CCC patients and the community. However, to prevent CCC amplification of the epidemic, the risk of Ebola virus-negative persons being exposed to virus within CCCs would have to be offset by a reduction in community transmission resulting from CCC use.

Evaluation of the Benefits and Risks of Introducing Ebola Community Care Centers, Sierra Leone

PubMed Central

Camacho, Anton; Checchi, Francesco; Waldman, Ron; Grais, Rebecca F.; Cabrol, Jean-Clement; Briand, Sylvie; Baguelin, Marc; Flasche, Stefan; Funk, Sebastian; Edmunds, W. John

2015-01-01

In some parts of western Africa, Ebola treatment centers (ETCs) have reached capacity. Unless capacity is rapidly scaled up, the chance to avoid a generalized Ebola epidemic will soon diminish. The World Health Organization and partners are considering additional Ebola patient care options, including community care centers (CCCs), small, lightly staffed units that could be used to isolate patients outside the home and get them into care sooner than otherwise possible. Using a transmission model, we evaluated the benefits and risks of introducing CCCs into Sierra Leone’s Western Area, where most ETCs are at capacity. We found that use of CCCs could lead to a decline in cases, even if virus transmission occurs between CCC patients and the community. However, to prevent CCC amplification of the epidemic, the risk of Ebola virus–negative persons being exposed to virus within CCCs would have to be offset by a reduction in community transmission resulting from CCC use. PMID:25694150

Comparison of surgical care deficiencies between US civil war hospitals and present-day hospitals in Sierra Leone.

PubMed

Crompton, Joseph; Kingham, T Peter; Kamara, T B; Brennan, Murray F; Kushner, Adam L

2010-08-01

Surgery is rapidly becoming a part of public health initiatives in developing countries. In collaboration with the Sierra Leone Ministry of Health and Sanitation, a team of local surgeons and surgeons from the organization Surgeons OverSeas (SOS) used the WHO Tool for Situational Analysis to Assess Emergency Surgical Care to quantify surgical capacity in Sierra Leone. These data were then compared to data collected from the Medical and Surgical History of the Civil War, a work documenting surgical care and hospitals during the US Civil War. There are 0.2 government hospital surgeons/100,000 people in Sierra Leone compared to 300 surgeons/100,000 soldiers in the Union Army. In Sierra Leone it is rare to have running water, fuel, anesthesia, and reliable X-rays. In comparison, US Civil War hospitals had reliable running water, fuel, and anesthesia. It is rare to manage open fractures, limb dislocations, amputations, and conditions requiring chest tubes in Sierra Leone, while these procedures were commonly employed in US Civil War hospitals. Government hospitals in present day Sierra Leone lack the infrastructure, personnel, supplies, and equipment to adequately provide emergency and essential surgical care. In a comparison of present day Sierra Leonean and US Civil War hospitals, the US Civil War facilities are equivalent and in many ways superior. It is hoped that such a comparison will aid advocacy efforts so that greater resources are devoted to improving emergency and essential surgical care in low- and middle-income countries.

Command and control of Sierra Leone's Ebola outbreak response: evolution of the response architecture.

PubMed

Ross, Emma

2017-05-26

Management, coordination and logistics were critical for responding effectively to the Ebola outbreak in Sierra Leone, and the duration of the epidemic provided a rare opportunity to study the management of an outbreak that endured long enough for the response to mature. This qualitative study examines the structures and systems used to manage the response, and how and why they changed and evolved. It also discusses the quality of relationships between key responders and their impact. Early coordination mechanisms failed and the President took operational control away from the Ministry of Health and Sanitation and established a National Ebola Response Centre, headed by the Minister of Defence, and District Ebola Response Centres. British civilian and military personnel were deeply embedded in this command and control architecture and, together with the United Nations Mission for Ebola Emergency Response lead, were the dominant coordination partners at the national level. Coordination, politics and tensions in relationships hampered the response, but as the response mechanisms matured, coordination improved and rifts healed. Simultaneously setting up new organizations, processes and plans as well as attempting to reconcile different cultures, working practices and personalities in such an emergency was bound to be challenging.This article is part of the themed issue 'The 2013-2016 West African Ebola epidemic: data, decision-making and disease control'. © 2017 The Author(s).

Sierra Nevada Science Review

Treesearch

Constance Millar; Amy Lind; Rowan Rowntree; Carl Skinner; Jared Verner; Bill Zielinski; Robert Ziemer

1998-01-01

In January, 1998, the Pacific Southwest Region and Pacific Southwest Research Station of the Forest Service initiated a collaborative effort to incorporate new information into planning future management of Sierra Nevada national forests. The project, known as the Sierra Nevada Framework for Conservation and Collaboration, will incorporate the latest scientific...

High Flight: History of the U.S. Air Force Academy

DTIC Science & Technology

2009-09-01

Albuquerque: University of New Mexico , 1999. (NA 6610.C66 U565 1999 Spec Coll) Netsch, Walter. Walter A. Netsch, FAIA: A Critical Appreciation and...Uniting Mountain & Plain: Cities, Law, and Environmental Change along the Front Range. Albuquerque: University of New Mexico Press, 2002. (Being...Rocky Mountain Regions of Southern Wyoming, Colorado, and Northern New Mexico . San Francisco: Sierra Club Books, 1991. (QH 104.5 .R6 B46 1991

International co-operative program on assessment and monitoring of air pollution effects on forests: The Sierra Ancha Experimental Forest, Arizona

Treesearch

Boris Poff; Daniel G. Neary

2008-01-01

At the end of the 2007 Fiscal Year, the Experimental Forests and Ranges (EFR) Synthesis Network Committee awarded funds to 18 sites to establish a strategic ICP Level II (described below) synthesis network in the United States. Eleven Experimental Forest were selected to be included in the network, as well as seven Long Term Ecological Research (LTER) sites. This will...

Population dynamics of the California Spotted Owl (Strix occidentalis occidentalis): a meta-analysis

USGS Publications Warehouse

Franklin, A.B.; Gutierrez, R.J.; Nichols, J.D.; Seamans, M.E.; White, Gary C.; Zimmerman, G.S.; Hines, J.E.; Munton, T.E.; LaHaye, W.S.; Blakesley, J.A.; Steger, G.N.; Noon, B.R.; Shaw, D.W.H.; Keane, J.J.; McDonald, T.L.; Britting, S.

2004-01-01

We conducted a meta-analysis to provide a current assessment of the population characteristics of California Spotted Owls (Strix occidentalis occidentalis) resident on four study areas in the Sierra Nevada and one study area in southern California. Our meta-analysis followed rigorous a priori analysis protocols, which we derived through extensive discussion during a week-long analysis workshop. Because there is great interest in the owl?s population status, we used state-of-the-art analytical methods to obtain results as precise as possible. Our meta-analysis included data from five California study areas located on the Lassen National Forest (1990-2000), Eldorado National Forest (1986-2000), Sierra National Forest (1990-2000), Sequoia and Kings Canyon national parks (1990-2000), and San Bernardino National Forest (1987-1998). Four of the five study areas spanned the length of the Sierra Nevada, whereas the fifth study area encompassed the San Bernardino Mountains in southern California. Study areas ranged in size from 343 km2 (Sequoia and Kings Canyon) to 2,200 km (Lassen). All studies were designed to use capture-recapture methods and analysis. We used survival in a meta-analysis because field methods were very similar among studies. However, we did not use reproduction in a meta-analysis because it was not clear if variation among individual study-area protocols used to assess reproductive output of owls would confound results. Thus, we analyzed fecundity only by individual study area. We examined population trend using the reparameterized Jolly-Seber capture-recapture estimator (8t) We did not estimate juvenile survival rates because of estimation problems and potential bias because of juvenile emigration from study areas. We used mark-recapture estimators under an information theoretic framework to assess apparent survival rates of adult owls. The pooled estimate for adult apparent survival for the five study areas was 0.833, which was lower than pooled adult survival rates (0.850) from 15 Northern Spotted Owl (S. o. caurina) studies. Estimates of survival from the best model on the Lassen (N = 0.829, 95% confidence intervals [CI = 0.798 to 0.857), Eldorado (N = 0.815, 95% CI = 0.772 to 0.851), Sierra (N = 0.818, 95% CI = 0.781 to 0.850), and San Bernardino (N = 0.813, 95% CI = 0.782 to 0.841) were not different. However, the Sequoia and Kings Canyon population had a higher survival rate (N = 0.877, 95% CI = 0.842 to 0.905) than the other study areas. Management history and forest structure (e.g. presence of giant sequoia [Sequoiadendron giganteum]) on the Sequoia and Kings Canyon study area differed from all other study areas. There appears to be little or no evidence for temporal variation in adult apparent survival on any of the study areas. Although we did not directly compare fecundity estimates were highly variable among years within all study areas (CV of temporal process variation = 0.672-0.817). Estimates for fecundity among the study populations were Lassen (b = 0.336, SE = 0.083), Eldorado (b = 0.409, SE = 0.087), Sierra (b = 0.284, SE = 0.073), Sequoia and Kings Canyon (b = 0.289, SE = 0.074), and San Bernardino (b = 0.362, SE = 0.038). During most years, the Sierra Nevada populations showed either moderate or poor fecundity. However, 1992 appeared to be an exceptional reproductive year for owls in the Sierra Nevada. In contrast, the San Bernardino population had less variable reproduction (CV of temporal process variation = 0.217), but experienced neither the exceptional reproduction of 1992 nor the extremely poor years that characterized all of the Sierra Nevada study areas. Because fecundity may be influenced by weather patterns, it was possible that the different weather patterns between southern California and the Sierra Nevada accounted for that difference. Except for Eldorado, all estimates for 8t, were <1.0, but none was different from 8 = 1.0 given the 95% confidence i

Late Miocene (Proto-Gulf) Extension and Magmatism on the Sonoran Margin

NASA Astrophysics Data System (ADS)

Gans, P.; MacMillan, I.; Roldan-Quintana, J.

2003-12-01

Constraints on the magnitude and character of late Miocene (Proto-Gulf) deformation on the Sonoran margin of the Gulf of California extensional province are key to understanding how and when Baja California was captured by the Pacific plate and how strain was partitioned during the early stages of this transtensional rift system. Our new geologic mapping in southwestern Sonora and 40Ar/39Ar dating of pre-, syn-, and post-tectonic volcanic units indicate that late Miocene deformation and volcanic activity were largely restricted to a NW-trending, 100-120 km wide belt adjacent to the coast. Inboard of this belt, NW-SE extension is mainly older (>15 Ma) and occurred in an intra-arc or back-arc setting. Proto-Gulf deformation within the coastal belt was profoundly transtensional, with NW-striking, dextral strike slip faults operating in concert with N-S and NNE-striking normal and oblique slip faults to produce an inferred NW or NNW tectonic transport direction. The total amount of late Miocene NW directed dextral shear within the coastal belt is still poorly constrained, but may exceed 100 km. The locus of deformation and volcanic activity migrated westward or northwestward within the Sonoran coastal belt. in the eastern portion (Sierra Libre and Sierra El Bacatete) major volcanic activity commenced at ˜13.0 Ma and peaked at 12.0 Ma, and major faulting and tilting is bracketed between 12.0 and 10.6 Ma. Further west in the Sierra El Aguaje/San Carlos region, major volcanic activity commenced at 11.5 Ma and peaked at 10.5 Ma, and most faulting and tilting is bracketed between 10.7 and 9.3 Ma. On the coastal mountains northwest of San Carlos, rift related faulting and tilting continued after 8.5 Ma. Voluminous late Miocene (13-8 Ma) volcanic rocks within the Sonoran coastal belt were erupted from numerous centers (e.g. Sierra Libre, Guaymas, Sierra El Aguaje). These thick volcanic sections are compositionally diverse (basalt to rhyolite, with abundant dacite and andesite), and are intimately associated in space and time with tectonic activity. Overall, the Sonoran coastal belt provides a spectacular example of distributed transtension and associated magmatism that ultimately led to rupturing of the continental lithosphere.

Black bear abundance, habitat use, and food habits in the Sierra San Luis, Sonora, Mexico

Treesearch

Rodrigo Sierra Corona; Ivan A. Sayago Vazquez; M. del Carmen Silva Hurtado; Carlos A. Lopez Gonzalez

2005-01-01

We studied black bears to determine habitat use, food habits, and abundance between April 2002 and November 2003 in the Sierra San Luis, Sonora. We utilized transects to determine spoor presence, camera traps for abundance, and scat analysis. During 2002, bears fed principally on plant material, and for 2003 on animal matter, namely livestock. Habitat use differed...

Abundance and rates of brood parasitism by brown-headed cowbirds over an elevational gradient in the southern Sierra Nevada

Treesearch

Kathryn Purcell; Jared Verner

1999-01-01

We studied Brown-headed Cowbird (Molothrus ater) parasitism rates in four forest types (ponderosa pine, mixed conifer, true fir, and lodgepole pine) over an elevational gradient in the southern Sierra Nevada. Cowbirds were most abundant and parasitism rates were highest at the lowest sites. All but one of 17 parasitized nests were found in the...

77 FR 23130 - Revisions to the California State Implementation Plan, Northern Sierra and Sacramento...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-18

... taking direct final action to approve revisions to the Northern Sierra Air Quality Management District (NSAQMD) and Sacramento Metropolitan Air Quality Management District (SMAQMD) portions of the California...) Northern Sierra Air Quality Management District. (i) Flexible Package Printing, Flat Wood Paneling Coatings...

Capacity building permitting comprehensive monitoring of a severe case of Lassa hemorrhagic fever in Sierra Leone with a positive outcome: case report.

PubMed

Grove, Jessica N; Branco, Luis M; Boisen, Matt L; Muncy, Ivana J; Henderson, Lee A; Schieffellin, John S; Robinson, James E; Bangura, James J; Fonnie, Mbalu; Schoepp, Randal J; Hensley, Lisa E; Seisay, Alhassan; Fair, Joseph N; Garry, Robert F

2011-06-20

Lassa fever is a neglected tropical disease with a significant impact on the health care system of endemic West African nations. To date, case reports of Lassa fever have focused on laboratory characterisation of serological, biochemical and molecular aspects of the disease imported by infected individuals from Western Africa to the United States, Canada, Europe, Japan and Israel. Our report presents the first comprehensive real time diagnosis and characterization of a severe, hemorrhagic Lassa fever case in a Sierra Leonean individual admitted to the Kenema Government Hospital Lassa Fever Ward. Fever, malaise, unresponsiveness to anti-malarial and antibiotic drugs, followed by worsening symptoms and onset of haemorrhaging prompted medical officials to suspect Lassa fever. A recombinant Lassa virus protein based diagnostic was employed in diagnosing Lassa fever upon admission. This patient experienced a severe case of Lassa hemorrhagic fever with dysregulation of overall homeostasis, significant liver and renal system involvement, the interplay of pro- and anti-inflammatory cytokines during the course of hospitalization and an eventual successful outcome. These studies provide new insights into the pathophysiology and management of this viral illness and outline the improved infrastructure, research and real-time diagnostic capabilities within LASV endemic areas.

Capacity building permitting comprehensive monitoring of a severe case of Lassa hemorrhagic fever in Sierra Leone with a positive outcome: Case Report

PubMed Central

2011-01-01

Lassa fever is a neglected tropical disease with a significant impact on the health care system of endemic West African nations. To date, case reports of Lassa fever have focused on laboratory characterisation of serological, biochemical and molecular aspects of the disease imported by infected individuals from Western Africa to the United States, Canada, Europe, Japan and Israel. Our report presents the first comprehensive real time diagnosis and characterization of a severe, hemorrhagic Lassa fever case in a Sierra Leonean individual admitted to the Kenema Government Hospital Lassa Fever Ward. Fever, malaise, unresponsiveness to anti-malarial and antibiotic drugs, followed by worsening symptoms and onset of haemorrhaging prompted medical officials to suspect Lassa fever. A recombinant Lassa virus protein based diagnostic was employed in diagnosing Lassa fever upon admission. This patient experienced a severe case of Lassa hemorrhagic fever with dysregulation of overall homeostasis, significant liver and renal system involvement, the interplay of pro- and anti-inflammatory cytokines during the course of hospitalization and an eventual successful outcome. These studies provide new insights into the pathophysiology and management of this viral illness and outline the improved infrastructure, research and real-time diagnostic capabilities within LASV endemic areas. PMID:21689444

Status of the California Red-legged Frog (Rana draytonii) in the State of Baja California, México

USGS Publications Warehouse

Peralta-Garcia, Anny; Hellingsworth, Bradford D.; Richmond, Jonathan Q.; Valdez-Villavicencio, Jorge H.; Ruiz-Campos, Gorgonio; Fisher, Robert N.; Cruz-Hernandez, Pedro; Galina-Tessaro, Patricia

2016-01-01

The California Red-legged Frog (Rana draytonii) is a threatened species in the United States that has undergone population declines, especially in southern California. Due to the lack of information on the status of Mexican populations, we surveyed for the presence of R. draytonii in Baja California and assessed possible threats to population persistence. Our study area extended from the U.S.-Mexican border to the southern end of the distribution of the species in the Sierra San Pedro Mártir. We found R. draytonii at six of 15 historical sites, none at five proxy sites (i.e., alternative sites chosen because the historical record lacked precise locality data), and four at 24 additional sites. The 10 occupied sites are within three watersheds in the Sierra San Pedro Mártir (two sites at Arroyo San Rafael, two sites at Arroyo San Telmo, and six sites at Arroyo Santo Domingo). We did not detect R. draytonii at 60% of historical sites, including the highest elevation site at La Encantada and multiple low-elevation coastal drainages, suggesting the species has declined in Baja California. The threats we noted most frequently were presence of exotic aquatic animal species, water diversion, and cattle grazing. Management of remaining populations and local education is needed to prevent further declines.

Level-2 Milestone 6007: Sierra Early Delivery System Deployed to Secret Restricted Network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bertsch, A. D.

This report documents the delivery and installation of Shark, a CORAL Sierra early delivery system deployed on the LLNL SRD network. Early ASC program users have run codes on the machine in support of application porting for the final Sierra system which will be deployed at LLNL in CY2018. In addition to the SRD resource, Shark, unclassified resources, Rzmanta and Ray, have been deployed on the LLNL Restricted Zone and Collaboration Zone networks in support of application readiness for the Sierra platform.

SIERRA Low Mach Module: Fuego User Manual Version 4.46.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sierra Thermal/Fluid Team

2017-09-01

The SIERRA Low Mach Module: Fuego along with the SIERRA Participating Media Radiation Module: Syrinx, henceforth referred to as Fuego and Syrinx, respectively, are the key elements of the ASCI fire environment simulation project. The fire environment simulation project is directed at characterizing both open large-scale pool fires and building enclosure fires. Fuego represents the turbulent, buoyantly-driven incompressible flow, heat transfer, mass transfer, combustion, soot, and absorption coefficient model portion of the simulation software. Syrinx represents the participating-media thermal radiation mechanics. This project is an integral part of the SIERRA multi-mechanics software development project. Fuego depends heavily upon the coremore » architecture developments provided by SIERRA for massively parallel computing, solution adaptivity, and mechanics coupling on unstructured grids.« less

SIERRA Low Mach Module: Fuego Theory Manual Version 4.44

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sierra Thermal /Fluid Team

2017-04-01

The SIERRA Low Mach Module: Fuego along with the SIERRA Participating Media Radiation Module: Syrinx, henceforth referred to as Fuego and Syrinx, respectively, are the key elements of the ASCI fire environment simulation project. The fire environment simulation project is directed at characterizing both open large-scale pool fires and building enclosure fires. Fuego represents the turbulent, buoyantly-driven incompressible flow, heat transfer, mass transfer, combustion, soot, and absorption coefficient model portion of the simulation software. Syrinx represents the participating-media thermal radiation mechanics. This project is an integral part of the SIERRA multi-mechanics software development project. Fuego depends heavily upon the coremore » architecture developments provided by SIERRA for massively parallel computing, solution adaptivity, and mechanics coupling on unstructured grids.« less

SIERRA Low Mach Module: Fuego Theory Manual Version 4.46.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sierra Thermal/Fluid Team

The SIERRA Low Mach Module: Fuego along with the SIERRA Participating Media Radiation Module: Syrinx, henceforth referred to as Fuego and Syrinx, respectively, are the key elements of the ASCI fire environment simulation project. The fire environment simulation project is directed at characterizing both open large-scale pool fires and building enclosure fires. Fuego represents the turbulent, buoyantly-driven incompressible flow, heat transfer, mass transfer, combustion, soot, and absorption coefficient model portion of the simulation software. Syrinx represents the participating-media thermal radiation mechanics. This project is an integral part of the SIERRA multi-mechanics software development project. Fuego depends heavily upon the coremore » architecture developments provided by SIERRA for massively parallel computing, solution adaptivity, and mechanics coupling on unstructured grids.« less

Lassa fever in post-conflict sierra leone.

PubMed

Shaffer, Jeffrey G; Grant, Donald S; Schieffelin, John S; Boisen, Matt L; Goba, Augustine; Hartnett, Jessica N; Levy, Danielle C; Yenni, Rachael E; Moses, Lina M; Fullah, Mohammed; Momoh, Mambo; Fonnie, Mbalu; Fonnie, Richard; Kanneh, Lansana; Koroma, Veronica J; Kargbo, Kandeh; Ottomassathien, Darin; Muncy, Ivana J; Jones, Abigail B; Illick, Megan M; Kulakosky, Peter C; Haislip, Allyson M; Bishop, Christopher M; Elliot, Deborah H; Brown, Bethany L; Zhu, Hu; Hastie, Kathryn M; Andersen, Kristian G; Gire, Stephen K; Tabrizi, Shervin; Tariyal, Ridhi; Stremlau, Mathew; Matschiner, Alex; Sampey, Darryl B; Spence, Jennifer S; Cross, Robert W; Geisbert, Joan B; Folarin, Onikepe A; Happi, Christian T; Pitts, Kelly R; Geske, F Jon; Geisbert, Thomas W; Saphire, Erica Ollmann; Robinson, James E; Wilson, Russell B; Sabeti, Pardis C; Henderson, Lee A; Khan, S Humarr; Bausch, Daniel G; Branco, Luis M; Garry, Robert F

2014-03-01

Lassa fever (LF), an often-fatal hemorrhagic disease caused by Lassa virus (LASV), is a major public health threat in West Africa. When the violent civil conflict in Sierra Leone (1991 to 2002) ended, an international consortium assisted in restoration of the LF program at Kenema Government Hospital (KGH) in an area with the world's highest incidence of the disease. Clinical and laboratory records of patients presenting to the KGH Lassa Ward in the post-conflict period were organized electronically. Recombinant antigen-based LF immunoassays were used to assess LASV antigenemia and LASV-specific antibodies in patients who met criteria for suspected LF. KGH has been reestablished as a center for LF treatment and research, with over 500 suspected cases now presenting yearly. Higher case fatality rates (CFRs) in LF patients were observed compared to studies conducted prior to the civil conflict. Different criteria for defining LF stages and differences in sensitivity of assays likely account for these differences. The highest incidence of LF in Sierra Leone was observed during the dry season. LF cases were observed in ten of Sierra Leone's thirteen districts, with numerous cases from outside the traditional endemic zone. Deaths in patients presenting with LASV antigenemia were skewed towards individuals less than 29 years of age. Women self-reporting as pregnant were significantly overrepresented among LASV antigenemic patients. The CFR of ribavirin-treated patients presenting early in acute infection was lower than in untreated subjects. Lassa fever remains a major public health threat in Sierra Leone. Outreach activities should expand because LF may be more widespread in Sierra Leone than previously recognized. Enhanced case finding to ensure rapid diagnosis and treatment is imperative to reduce mortality. Even with ribavirin treatment, there was a high rate of fatalities underscoring the need to develop more effective and/or supplemental treatments for LF.

Implementing a Web-Based Decision Support System to Spatially and Statistically Analyze Ecological Conditions of the Sierra Nevada

NASA Astrophysics Data System (ADS)

Nguyen, A.; Mueller, C.; Brooks, A. N.; Kislik, E. A.; Baney, O. N.; Ramirez, C.; Schmidt, C.; Torres-Perez, J. L.

2014-12-01

The Sierra Nevada is experiencing changes in hydrologic regimes, such as decreases in snowmelt and peak runoff, which affect forest health and the availability of water resources. Currently, the USDA Forest Service Region 5 is undergoing Forest Plan revisions to include climate change impacts into mitigation and adaptation strategies. However, there are few processes in place to conduct quantitative assessments of forest conditions in relation to mountain hydrology, while easily and effectively delivering that information to forest managers. To assist the USDA Forest Service, this study is the final phase of a three-term project to create a Decision Support System (DSS) to allow ease of access to historical and forecasted hydrologic, climatic, and terrestrial conditions for the entire Sierra Nevada. This data is featured within three components of the DSS: the Mapping Viewer, Statistical Analysis Portal, and Geospatial Data Gateway. Utilizing ArcGIS Online, the Sierra DSS Mapping Viewer enables users to visually analyze and locate areas of interest. Once the areas of interest are targeted, the Statistical Analysis Portal provides subbasin level statistics for each variable over time by utilizing a recently developed web-based data analysis and visualization tool called Plotly. This tool allows users to generate graphs and conduct statistical analyses for the Sierra Nevada without the need to download the dataset of interest. For more comprehensive analysis, users are also able to download datasets via the Geospatial Data Gateway. The third phase of this project focused on Python-based data processing, the adaptation of the multiple capabilities of ArcGIS Online and Plotly, and the integration of the three Sierra DSS components within a website designed specifically for the USDA Forest Service.

Macroeconomic costs of the unmet burden of surgical disease in Sierra Leone: a retrospective economic analysis.

PubMed

Grimes, Caris E; Quaife, Matthew; Kamara, Thaim B; Lavy, Christopher B D; Leather, Andy J M; Bolkan, Håkon A

2018-03-14

The Lancet Commission on Global Surgery estimated that low/middle-income countries will lose an estimated cumulative loss of US$12.3 trillion from gross domestic product (GDP) due to the unmet burden of surgical disease. However, no country-specific data currently exist. We aimed to estimate the costs to the Sierra Leone economy from death and disability which may have been averted by surgical care. We used estimates of total, met and unmet need from two main sources-a cluster randomised, cross-sectional, countrywide survey and a retrospective, nationwide study on surgery in Sierra Leone. We calculated estimated disability-adjusted life years from morbidity and mortality for the estimated unmet burden and modelled the likely economic impact using three different methods-gross national income per capita, lifetime earnings foregone and value of a statistical life. In 2012, estimated, discounted lifetime losses to the Sierra Leone economy from the unmet burden of surgical disease was between US$1.1 and US$3.8 billion, depending on the economic method used. These lifetime losses equate to between 23% and 100% of the annual GDP for Sierra Leone. 80% of economic losses were due to mortality. The incremental losses averted by scale up of surgical provision to the Lancet Commission target of 80% were calculated to be between US$360 million and US$2.9 billion. There is a large economic loss from the unmet need for surgical care in Sierra Leone. There is an immediate need for massive investment to counteract ongoing economic losses. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Fumarole/plume and diffuse CO2 emission from Sierra Negra volcano, Galapagos archipelago

NASA Astrophysics Data System (ADS)

Padron, E.; Hernandez Perez, P. A.; Perez, N.; Theofilos, T.; Melian, G.; Barrancos, J.; Virgil, G.; Sumino, H.; Notsu, K.

2009-12-01

The active shield-volcano Sierra Negra is part of the Galapagos hotspot. Sierra Negra is the largest shield volcano of Isabela Island, hosting a 10 km diameter caldera. Ten historic eruptions have occurred and some involved a frequently visited east caldera rim fissure zone called Volcan Chico. The last volcanic event occurred in October 2005 and lasted for about a week, covering approximately twenty percent of the eastern caldera floor. Sierra Negra volcano has experienced some significant changes in the chemical composition of its volcanic gas discharges after the 2005 eruption. This volcanic event produced an important SO2 degassing that depleted the magmatic content of this gas. Not significant changes in the MORB and plume-type helium contribution were observed after the 2005 eruption, with a 65.5 % of MORB and 35.5 % of plume contribution. In 2006 a visible and diffuse gas emission study was performed at the summit of Sierra Negra volcano, Galapagos, to evaluate degassing rate from this volcanic system. Diffuse degassing at Sierra Negra was mainly confined in three different DDS: Volcan Chico, the southern inner margin of the caldera, and Mina Azufral. These areas showed also visible degassing, which indicates highly fractured areas where volcano-hydrothermal fluids migrate towards surface. A total fumarole/plume SO2 emission of 11 ± 2 td-1 was calculated by mini-DOAS ground-based measurements at Mina Azufral fumarolic area. Molar ratios of major volcanic gas components were also measured in-situ at Mina Azufral with a portable multisensor. The results showed H2S/SO2, CO2/SO2 and H2O/SO2 molar ratios of 0.41, 52.2 and 867.9, respectively. Multiplying the observed SO2 emission rate times the observed (gas)i/SO2 mass ratio we have estimated other volatiles emission rates. The results showed that H2O, CO2 and H2S emission rates from Sierra Negra are 562, 394, and 2.4 t d-1, respectively. The estimated total output of diffuse CO2 emission from the summit of Sierra Negra was 989 ± 85 t d-1. Estimated diffuse/plume CO2 emission ratio was 2.5.

Factors Underlying Ebola Virus Infection Among Health Workers, Kenema, Sierra Leone, 2014-2015.

PubMed

Senga, Mikiko; Pringle, Kimberly; Ramsay, Andrew; Brett-Major, David M; Fowler, Robert A; French, Issa; Vandi, Mohamed; Sellu, Josephine; Pratt, Christian; Saidu, Josephine; Shindo, Nahoko; Bausch, Daniel G

2016-08-15

Ebola virus disease (EVD) in health workers (HWs) has been a major challenge during the 2014-2015 outbreak. We examined factors associated with Ebola virus exposure and mortality in HWs in Kenema District, Sierra Leone. We analyzed data from the Sierra Leone National Viral Hemorrhagic Fever Database, contact tracing records, Kenema Government Hospital (KGH) staff and Ebola Treatment Unit (ETU) rosters, and burial logs. From May 2014 through January 2015, 600 cases of EVD originated in Kenema District, including 92 (15%) HWs, 66 (72%) of whom worked at KGH. Among KGH medical staff and international volunteers, 18 of 62 (29%) who worked in the ETU developed EVD, compared with 48 of 83 (58%) who worked elsewhere in the hospital. Thirteen percent of HWs with EVD reported contact with EVD patients, while 27% reported contact with other infected HWs. The number of HW EVD cases at KGH declined roughly 1 month after implementation of a new triage system at KGH and the opening of a second ETU within the district. The case fatality ratio for HWs and non-HWs with EVD was 69% and 74%, respectively. The cluster of HW EVD cases in Kenema District is one of the largest ever reported. Most HWs with EVD had potential virus exposure both inside and outside of hospitals. Prevention measures for HWs must address a spectrum of infection risks in both formal and informal care settings as well as in the community. © 2016 World Health Organization; licensee Oxford Journals.

Patterns of orographic uplift in the Sierra Nevada and their relationship to upper-level atmospheric circulation

USGS Publications Warehouse

Aguado, Edward; Cayan, Daniel R.; Reece, Brian D.; Riddle, Larry

1993-01-01

We examine monthly and seasonal patterns of precipitation across various elevations of the eastern Central Valley of California and the Sierra Nevada. A measure of the strength of the orographic effect called the “precipitation ratio” is calculated, and we separate months into four groups based on being wet or dry and having low or high precipitation ratios. Using monthly maps of mean 700-mb height anomalies, we describe the northern hemisphere mid-tropospheric circulation patterns associated with each of the four groups. Wet months are associated with negative height anomalies over the eastern Pacific, as expected. However, the orientation of the trough is different for years with high and low precipitation ratios. Wet months with high ratios typically have circulation patterns factoring a west-southwest to east-northeast storm track from around the Hawaiian Islands to the Pacific Northwest of the United States. Wet months with low precipitation ratios are associated with a trough centered near the Aleutians and a northwest to southeast storm track. Dry months are marked by anticyclones in the Pacific, but this feature is more localized to the eastern Pacific for months with low precipitation ratios than for those with high ratios. Using precipitation gauge and snow course data from the American River and Truckee-Tahoe basins, we determined that the strength of the orographic effect on a seasonal basis is spatially coherent at low and high elevations and on opposite sides of the Sierra Nevada crestline.

Crustal Deformation Across the Basin and Range Province, Western United States, Measured with the Global Positioning System, 1992-2002

NASA Astrophysics Data System (ADS)

Hammond, W. C.; Thatcher, W.

2002-12-01

The Basin and Range province of the western United States lies east of the Sierra Nevada mountains and accommodates roughly 25% of the motion between the North American and Pacific Plates in this region. It is experiencing both active extension and dextral shear, whose orientation is consistent with relative plate motion, suggesting that the province is an important part of the overall plate boundary system. We present results from recent measurement of Basin and Range crustal motion using the Global Positioning System (GPS). As of September 2002, ten years of deformation will have been observed with GPS measurements in 1992,1996, 1998 and 2002. The 800 km long east-to-west line of campaign-style geodetic benchmarks extends from east of the Wasatch fault zone in Utah to west of the Genoa fault zone and Lake Tahoe in California's Northern Sierra Nevada mountains, primarily along Interstate Highway 50. In all there are velocities at 91 GPS sites, nearly double the number previously presented (Thatcher et al. [1999]), all of which will be measured in September 2002. Incorporating this new data is expected to reduce the uncertainty in earlier measurements that show the motion of the Sierra Nevada block with respect to non-deforming North America to be accommodated by right lateral shear and extensional deformation in Nevada and Utah. Velocity variation of about 9 mm/yr is concentrated in the western one-third of the network, with a lesser amount (roughly 3 mm/yr) localized to the easternmost edge of the network, in the vicinity of the Wasatch fault zone. Recent densification of the GPS network across these two zones will also improve the spatial resolution of the deformation in these regions. The greatest rate of present-day deformation occurs near the ruptures of the Fairview Peak and Rainbow Mountain earthquakes in the Central Nevada Seismic Zone, extending west past the Genoa fault into the Sierra Nevada. This strain rate pattern is correlated with the concentration of historic faulting and seismicity in the western half of Nevada and eastern California, but is less well correlated with the relatively broad distribution of faults with Holocene and late Quaternary age. To process the data we use the GIPSY/OASIS II and Quasi-Observation Combination Analysis (Dong et al. [1998]) software packages and incorporate data from continuously recording GPS stations in California and Nevada.

Map showing mineral resource potential of the Sierra Ancha Wilderness and Salome Study Area, Gila County, Arizona

USGS Publications Warehouse

Otton, James K.; Light, Thomas D.; Shride, Andrew F.; Bergquist, Joel R.; Wrucke, Chester T.; Theobald, Paul K.; Duval, Joseph S.; Wilson, Dolores M.

1981-01-01

The Wilderness Act (Public Law 88-577, Sept. 3, 1964) and certain related Acts require the Geological Survey and the Bureau of Mines to survey certain areas on Federal lands to determine their mineral-resource potential. Results must be made available to the public and be submitted to the Administration and the Congress. These maps and reports present the results of a geologic and mineral survey of the Sierra Ancha Wilderness and Salome Study Area, Gila County, Arizona.

Geological remote sensing in Africa

NASA Technical Reports Server (NTRS)

Sabins, Floyd F., Jr.; Bailey, G. Bryan; Abrams, Michael J.

1987-01-01

Programs using remote sensing to obtain geologic information in Africa are reviewed. Studies include the use of Landsat MSS data to evaluate petroleum resources in sedimentary rock terrains in Kenya and Sudan and the use of Landsat TM 30-m resolution data to search for mineral deposits in an ophiolite complex in Oman. Digitally enhanced multispectral SPOT data at a scale of 1:62,000 were used to map folds, faults, diapirs, bedding attitudes, and stratigraphic units in the Atlas Mountains in northern Algeria. In another study, SIR-A data over a vegetated and faulted area of Sierra Leone were compared with data collected by the Landsat MSS and TM systems. It was found that the lineaments on the SIR-A data were more easily detected.

KSC-2011-5116

NASA Image and Video Library

2011-07-07

CAPE CANAVERAL, Fla. -- NASA and Sierra Nevada Space Systems (SNSS) of Sparks, Nev., sign a Space Act Agreement that will offer the company technical capabilities from Kennedy Space Center's uniquely skilled work force. Sitting, from left, are Kennedy Public Affairs Director Lisa Malone; NASA Administrator Charlie Bolden; Kennedy Center Director Bob Cabana; and Mark Sirangelo, head of Sierra Nevada. Standing, from left, are Frank DiBello, president of Space Florida; Joyce Riquelme, manager of Kennedy's Center Planning and Development Office; John Curry, director of Sierra Nevada's Systems Integration, Test and Operations; Kennedy Deputy Director Janet Petro; Jim Voss, vice president of Sierra Nevada's Space Exploration Systems; and Merri Sanchez, senior director of Sierra Nevada's Space Exploration Systems. Kennedy will help Sierra Nevada with the ground operations support of its lifting body reusable spacecraft called "Dream Chaser," which resembles a smaller version of the space shuttle orbiter. The spacecraft would carry as many as seven astronauts to the space station. Through the new agreement, Kennedy's work force will use its experience of processing the shuttle fleet for 30 years to help Sierra Nevada define and execute Dream Chaser's launch preparations and post-landing activities. In 2010 and 2011, Sierra Nevada was awarded grants as part of the initiative to stimulate the private sector in developing and demonstrating human spaceflight capabilities for NASA's Commercial Crew Program. The goal of the program, which is based in Florida at Kennedy, is to facilitate the development of a U.S. commercial crew space transportation capability by achieving safe, reliable and cost-effective access to and from the space station and future low Earth orbit destinations. Photo credit: NASA/Jim Grossmann

KSC-2011-5115

NASA Image and Video Library

2011-07-07

CAPE CANAVERAL, Fla. -- NASA and Sierra Nevada Space Systems (SNSS) of Sparks, Nev., prepare to sign a Space Act Agreement that will offer the company technical capabilities from Kennedy Space Center's uniquely skilled work force. Sitting, from left, are Kennedy Public Affairs Director Lisa Malone; NASA Administrator Charlie Bolden; Kennedy Center Director Bob Cabana; and Mark Sirangelo, head of Sierra Nevada. Standing, from left, are Joyce Riquelme, manager of Kennedy's Center Planning and Development Office; John Curry, director of Sierra Nevada's Systems Integration, Test and Operations; Kennedy Deputy Director Janet Petro; Jim Voss, vice president of Sierra Nevada's Space Exploration Systems; and Merri Sanchez, senior director of Sierra Nevada's Space Exploration Systems. Kennedy will help Sierra Nevada with the ground operations support of its lifting body reusable spacecraft called "Dream Chaser," which resembles a smaller version of the space shuttle orbiter. The spacecraft would carry as many as seven astronauts to the space station. Through the new agreement, Kennedy's work force will use its experience of processing the shuttle fleet for 30 years to help Sierra Nevada define and execute Dream Chaser's launch preparations and post-landing activities. In 2010 and 2011, Sierra Nevada was awarded grants as part of the initiative to stimulate the private sector in developing and demonstrating human spaceflight capabilities for NASA's Commercial Crew Program. The goal of the program, which is based in Florida at Kennedy, is to facilitate the development of a U.S. commercial crew space transportation capability by achieving safe, reliable and cost-effective access to and from the space station and future low Earth orbit destinations. Photo credit: NASA/Jim Grossmann

An isotopic study of the Coso, California, geothermal area

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fournier, R.O.; Thompson, J.M.

1982-10-01

Thirty-nine water samples were collected from the Coso geothermal system and vicinity and were analyzed for major chemical constituents and deltaD and delta/sup 18/O. Non-thermal ground waters from the Coso Range were found to be isotopically heavier than non-thermal ground waters from the Sierra Nevada to the west. The deltaD value for the deep thermal water at Coso is similar to that of the Sierra water, suggesting that the major recharge for the hydrothermal system comes from the Sierra Nevada rather than from local precipitation on the Coso Range. The delta/sup 18/O values of the thermal water are about 7/supmore » 0//00 heavier than those of the Sierra water. This shift in delta/sup 18/O is the result of water-rock reaction at high temperatures, and the magnitude of the shift indicates that the ratio of rock to total water has been large for the system up to its present stage of development. The isotopic data are compatible with the geochemical model previously proposed by Fournier.« less

[Impact of traditionally managed forest units on the landscape connectivity of Sierra de Los Tuxtlas, Mexico].

PubMed

Aguilar Vásquez, Yunin; Aliphat Fernández, Mario Manuel; Caso Barrera, Laura; Del Amo Rodríguez, Silvia; Sánchez Gómez, Maria De Lourdes; Martínez-Carrera, Daniel

2014-09-01

The ever-increasing establishment of landscape mosaics is expressed as a surrounding matrix of agricultural activities, which frames patches or remnants of the original vegetation cover. Conservation actions should be aimed to establish or to increase those interactive systems, which help to maintain the land- scape flow through linkages. Spaces occupied by traditional management systems retain and support this func- tion. In this paper, we used Geographic Information Systems to evaluate the importance of traditionally managed forest units ('acahuales'-coffee plantations) and to assess landscape connectivity in the indigenous Popoluca area of Sierra de los Tuxtlas, Mexico. The cartographic material used to establish the types of vegetation and their coverture included the period 1991-2008. At landscape level, four indices were used to assess the general situation of the habitat network, and to identify the patches of high priority. Individually, indices evaluated if patches were important for their area, their potential flow or their connecting function. Results showed that the landscape is functioning as a single system, but having low connectivity. Values improved when traditionally managed forest patches were considered as viable habitat. We detected 367 patches of very high priority, 80% belonging to forests managed traditionally. Patches were important for their potential flow (size and topologi- cal relationships). Only 70 patches were significant for their function as biological corridors between largest forests located at the top of the volcanoes, and are mostly managed forest (75%). We concluded that the units of traditionally managed forest play a significant role in landscape connectivity maintenance.

Tertiary vegetation history

Treesearch

C. I. Millar

1996-01-01

The Tertiary period, from 2.5 to 65 million years ago, was the time oforigin of the modern Sierra Nevada landscape. Climates, geology,and vegetation changed drastically in the Sierra Nevada during thistime, and analyses of this period provide both context for and insightinto vegetation dynamics of the current and future Sierra. During theearly Tertiary, warm-humid,...

Current distribution of the american marten, Martes americana, in California

Treesearch

Thomas E. Kurcera; William J. Zielinski; Reginald H. Barrett

1996-01-01

We describe the current distribution of the American marten, Martes americana, in California based on field surveys conducted between 1989 and 1995 that used either sooted track-plates or cameras. The Sierra Nevada marten, M. a. sierrae, occupies much of its historic range from northwestern Shasta County to the southern Sierra...

Acting Administrator Lightfoot Visits Sierra Nevada Corporation

NASA Image and Video Library

2017-04-06

Vice President, Space Exploration Systems (SES) at Sierra Nevada Corporation Steve Lindsey, left, speaks with acting NASA Administrator Robert Lightfoot, center, and acting NASA Deputy Administrator Lesa Roe, left, about the Dream Chaser Space System simulator, Thursday, April 6, 2017 during a visit to Sierra Nevada Corporation in Louisville, Colo. Photo Credit: (NASA/Joel Kowsky)

High Sierra Ecosystems: The Role of Fish Stocking in Amphibian Declines

Treesearch

Kathleen Matthews

2003-01-01

With a rich diversity of aquatic habitats, including deep lakes, shallow ponds, and rushing streams, Dusy Basinin Sequoia-Kings Canyon National Parks typifies the high Sierra ecosystem where mountain yellow-legged frogs usually thrive. Yet throughout the Sierra, aquatic ecologist Kathleen Matthews found entire water basins empty of these amphibians. Comprehensive...

High Sierra ecosystems: the role of fish stocking in amphibian declines

Treesearch

Anne M. Rosenthal; Kathleen R. Featured: Matthews

2003-01-01

With a rich diversity of aquatic habitats, including deep lakes, shallow ponds, and rushing streams, Dusy Basin in Sequoia-Kings Canyon National Parks typifies the high Sierra ecosystem where mountain yellow-legged frogs usually thrive. Yet throughout the Sierra, aquatic ecologist Kathleen Matthews found entire water basins empty of these amphibians. Comprehensive...

Proceedings of the Sierra Nevada Science Symposium

Treesearch

Dennis D. Murphy; Peter A. Stine

2004-01-01

Land and resource management issues in the Sierra Nevada are becoming increasingly complex and controversial. The objective of the Sierra Nevada Science Symposium was to provide a synoptic overview of the current state of scientific knowledge related to key management issues. Attempts were made to tie recent scientific findings to applications in land management and...

Biodiversity in the Sierra Nevada

Treesearch

Dennis D. Murphy; Erica Fleishman; Peter A. Stine

2004-01-01

The earliest explorers of the Sierra Nevada hailed the mountain range for its unsurpassed scenery. Although a significant component of that beauty was an especially rich assemblage of plants and animals, it was not until many decades later that the Sierra Nevada's wealth of biodiversity was appreciated fully and documented in earnest. Indeed, by the time...

Introduction

Treesearch

Jonathan W. Long; Carl Skinner; Hugh Safford; Susan Charnley; Patricia Winter

2014-01-01

National forests in the Sierra Nevada and Southern Cascade bioregions have begun to review and revise their land and resource management plans (LRMPs). The three most southern national forests of the Sierra Nevada (Inyo, Sequoia, and Sierra) were selected to be the lead forests for the Forest Service Pacific Southwest Region (Region 5) and are among the first of the...

Airborne Pesticides as an Unlikely Cause for Population Declines of Alpine Frogs in the Sierra Nevada, California

EPA Science Inventory

Airborne pesticides from the Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the mountain yellow-legged frog complex (Rana muscosa and R. sierrae) in the Sierra Nevada. We measured...

Inventory of Commercial Hardwoods in the High Sierra

Treesearch

Norman H. Pillsbury; George L. McCaskill

1991-01-01

A hardwood resources assessment was completed for the Sierra Economic Development District in the north central Sierra Nevada. The assessment included the development of a tree grading system for the major hardwood species in the area, an inventory of the hardwood resources, and recommendations for hardwood management. Hardwood volumes of total wood available for...

77 FR 23476 - Energia Sierra Juarez U.S., LLC; Supplemental Notice That Initial Market-Based Rate Filing...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-19

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER12-1470-000] Energia Sierra Juarez U.S., LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for... Energia Sierra Juarez U.S., LLC's application for market-based rate authority, with an accompanying rate...

Correlation of the Klamath Mountains and Sierra Nevada

USGS Publications Warehouse

Irwin, William P.

2003-01-01

This report graphically portrays the broadly parallel tectonic development of the Klamath Mountains and Sierra Nevada from early Paleozoic to Early Cretaceous time. It is dedicated to J.S. Diller of the U.S. Geological Survey who, during his pioneer field studies a century ago, recognized significant similarities between these two important provinces. The report is based mainly on the numerous published reports of the field and laboratory studies by various geologists and students during the last century, and to a lesser extent on my own field work which has been substantial in the Klamath Mountains but minimal in the Sierra Nevada. For brevity, required by the format of this report, little of the extensive literature pertaining to these two provinces is referenced. This report is preliminary in nature and was prepared as an aid to further study of the tectonic relations between the Klamath Mountains and Sierra Nevada. This report consists of two sheets: Sheet 1, Map showing accreted terranes and plutons of the Klamath Mountains and Sierra Nevada, and Sheet 2, Successive accretionary episodes of the Klamath mountains and northern part of Sierra Nevada, showing related plutonic, volcanic, and metamorphic events. The map on Sheet 1 was compiled and modified from two Open-File maps (Irwin and Wooden, 1999 and 2001) which had been compiled and modified mainly from Jennings (1977), Harwood (1992), Irwin (1994), Jayko (1988), Graymer and Jones (1994), Edelman and Sharp (1989), Schweickert and others (1999), Saucedo and Wagner(1992), Saleeby and Sharp (1980), Wagner and others (1981), and various other sources. For detailed lists of the sources for the isotopic age data used in Sheets 1 and 2, see Irwin and Wooden (1999 and 2001). On Sheet 2, the accretionary episodes are shown sequentially from left to right in two tiers of figures. Episodes for the Klamath Mountains are in the upper tier; correlative episodes of the Sierra Nevada are directly below in the lower tier. The sequence shown for the Klamath Mountains is modified from Irwin and Mankinen (1998) and Irwin and Wooden (1999). The episodes are named for the accreting terranes of the Klamath Mountains, but those names may not be suitable for reference to the correlative episodes of the Sierra Nevada. In the figure for each episode, a heavy black line represents the active suture that separated oceanic crustal rocks on the left from the earlier accreted terranes on the right. Plutons are particularly useful for timing the accretionary episodes. The preaccretionary plutons, which commonly represent the roots of oceanic volcanic arcs, are shown in the accreting oceanic crustal rocks to the left of the heavy black line. The accretionary plutons consist of rock that has been subducted and remobilized as magma during the accretionary process and injected into an overlying earlier accreted terrane on the right of the heavy black line. Thus, isotopic dating of the accretionary plutons (preferably U/Pb dates measured on zircon extracted from the plutonic rock) provides a useful basis for assigning ages to the accretionary episodes. Many plutons are rootless at depth, as they tend to be truncated by the subduction zone sutures of younger accreting terranes. Volcanic deposits resulting from accretionary episodes apparently are uncommon except for those deposited on the backstop terranes. In the Klamath Mountains, the Eastern Klamath terrane, which consists of the Yreka, Trinity and Redding subterranes, was the backstop for the Central Metamorphic and younger accretionary episodes, and displays a remarkable record of sedimentation, volcanism and plutonism from Silurian-Devonian to Jurassic time. In the Sierra Nevada, the correlative backstop was the Northern Sierra terrane which shows a similar long record of volcanism in the Taylorsville, Permian, and Jurassic volcanic arc sequences. During some accretionary episodes the subducting oceanic rocks were dynamically metamorphosed to schist along the suture zone beneath the overriding accreted terranes. Examples of this in the Klamath Mountains are the Devonian Salmon and Abrams Schists of the Central Metamorphic terrane, the Triassic(?) schist of the Fort Jones terrane , and the Early Cretaceous South Fork Mountain Schist that structurally underlies Klamath Mountains terranes along much of the western edge of the province. The Fort Jones terrane and South Fork Mountains Schist were metamorphosed under blueschist-facies conditions. In the Sierra Nevada, schist that is correlative with the Central Metamorphic terrane is present in patches along the Feather River terrane (see Hacker and Peacock, 1990); the Triassic(?) Red Ant Schist is correlative with the Fort Jones terrane; but a correlative of the South Fork Mountain Schist is not present. In addition to the similarities in the sequences of accretion, plutonism, volcanism, and metamorphism, strong ties between the two provinces are also provided by paleontologic data. The Permian McCloud fusulinid fauna of the Redding subterrane also is present in the Northern Sierra terrane. Rare Tethyan fusulinids are found in Permian limestone of the Eastern Hayfork terrane of the Klamath Mountains and also in limestone blocks in the Central Belt of the Sierra Nevada. Ichthyosaur fossils have been collected from the Triassic of both the Redding subterrane and Northern Sierra terrane. Jurassic ammonites and the pelecypod Buchia concentrica occur in both the Galice Formation of the western Klamath Mountains and the Mariposa Formation of the western Sierra Nevada. Events that preceded the Central Metamorphic episode prior to Silurian-Devonian time are not clearly understood and are not shown in the succession of diagrams on Sheet 2. The oldest rocks of the Klamath Mountains are Neoproterozic and they predate the Central Metamorphic episode by possibly a hundred million years or more. They include ophiolitic rocks of the Trinity subterrane and the Antelope Mountain Quartzite of the Yreka subterrane (see Mankinen and others, 2002). In the Sierra Nevada, correlatives of the ancient ophiolitic rocks may be part of the Feather River terrane. Although Neoproterozoic fossils have not yet been found in the Sierra Nevada, petrologic study shows the quartzite of the Lang sequence is closely similar to the Antelope Mountain Quartzite (see Bond and Devay, 1980). Correlation of the two quartzite formations is also suggested by the similarity of their positions in the accretionary sequence.

Application of the Water Evaluation and Planning (WEAP) System for Integrated Hydrologic and Scenario-based Water Resources Systems Modeling in the Western Sierra Nevada

NASA Astrophysics Data System (ADS)

Mehta, V. K.; Purkey, D. R.; Young, C.; Joyce, B.; Yates, D.

2008-12-01

Rivers draining western slopes of the Sierra Nevada provide critical water supply, hydropower, fisheries and recreation services to California. Coordinated efforts are under way to better characterize and model the possible impacts of climate change on Sierra Nevada hydrology. Research suggests substantial end-of- century reductions in Sierra Nevada snowpack and a shift in the center of mass of the snowmelt hydrograph. Management decisions, land use change and population growth add further complexity, necessitating the use of scenario-based modeling tools. The Water Evaluation and Planning (WEAP) system is one of the suite of tools being employed in this effort. Unlike several models that rely on perturbation of historical runoff data to simulate future climate conditions, WEAP includes a dynamically integrated watershed hydrology module that is forced by input climate time series. This allows direct simulation of water management response to climate and land use change. This paper presents ABY2008, a WEAP application for the Yuba, Bear and American River (ABY) watersheds of the Sierra Nevada. These rivers are managed by water agencies and hydropower utilities through a complex network of reservoirs, dams, hydropower plants and water conveyances. Historical watershed hydrology in ABY2008 is driven by a 10 year weekly climate time series from 1991-2000. Land use and soils data were combined into 12 landclasses representing each of 324 hydrological response units. Hydrologic parameters were incorporated from a calibration against observed streamflow developed for the entire western Sierra. Physical reservoir data, operating rules, and water deliveries to water agencies were obtained from public documents of water agencies and power utilities that manage facilities in the watersheds. ABY2008 includes 25 major reservoirs, 39 conveyances, 33 hydropower plants and 14 transmission links to 13 major water demand points. In WEAP, decisions for transferring water at diversion points from rivers to facilities are based on assigned priorities. Priorities in ABY2008 follow Federal Energy Regulatory Commission license requirements and power purchase agreements between licensees and water/power contractors. These generally allocate water according to the following priorities - (i) maintaining minimum instream flows below diversions;(ii) irrigation and domestic consumptive water demands; and (iii) power generation. ABY2008 simulations compared well with historical annual and monthly hydropower generation. Annual hydropower for 31 hydropower plants was simulated with r2=0.85 and ste=58 GWh. Monthly hydropower for 21 power plants owned by three water agencies were simulated with r2= 0.74 and ste= 7.4 GWh. We also present early results on how climate change, manifest by increasing weekly average temperatures, translates into changes in the projected timing of runoff and patterns of snow accumulation. Consequent changes in met water supply demands and hydropower generated are discussed. Further, stakeholders in the northern Sierra seek to use ABY2008 to investigate management scenarios geared towards increased conservation flows for fish populations, and the possible tradeoffs thereof with hydropower and water supply. These applications with ABY2008 illustrate the substantial utility of scenario-based modeling with the WEAP system.

Surface motion of active rock glaciers in the Sierra Nevada, California, USA: inventory and a case study using InSAR

Treesearch

L. Liu; C.I. Millar; R.D. Westfall; H.A. Zebker

2013-01-01

Despite the abundance of rock glaciers in the Sierra Nevada of California, USA, few efforts have been made to measure their surface flow. Here we use the interferometric synthetic aperture radar (InSAR) technique to compile a~benchmark inventory describing the kinematic state of 59 active rock glaciers in this region. Statistically, these rock glaciers moved at...

Preliminary investigation of exceptionally strong winds in mountainous areas of New Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reynolds, R.D.; Barnett, K.M.

1980-10-01

The mean wind speed in four mountainous areas in New Mexico were sampled for one year using wind data accumulators. The sites studied were: (1) San Augustin Pass, 15 miles northeast of Las Cruces; (2) Sierra Grande, an isolated peak midway between Raton and Clayton; (3) Buck Mountain, 10 miles northeast of Sierra Blanca Peak near Ruidoso, and (4) Palomas Mesa, 20 miles west-southwest of Tucumcari.

Characteristics of nest trees and nest sites of California spotted owls in coniferous forests of the southern Sierra Nevada

Treesearch

George N. Steger; Thomas E. Munton; Kenneth D. Johnson; Gary E. Eberlein

1997-01-01

We described 86 nest sites of California spotted owl (Sh-ix occidentalis occrdentalzs) and tested for differences in vegetation structure at nest locations rn conifer-dominated stands in 2 study areas, the Sierra National Forest (SNF) and Sequoia and Kings Canyon National Parks (SNP), California. All nests were between 1061 and 2414 m in elevation, 52 were side-cavity...

Climate, rain shadow, and human-use influences on fire regimes in the eastern Sierra Nevada, California, USA

Treesearch

M.P. North; K.M. van de Water; S.L. Stephens; B.M. Collins

2009-01-01

There have been few fire history studies of eastern Sierra Nevada forests in California, USA, where a steep elevation gradient, rain shadow conditions, and forest stand isolation may produce different fire regimes than those found on the range’s western slope. We investigated historic fire regimes and potential climate influences on four forest types ranging in...

Short-term effects of fire and forest thinning on truffle abundance and consumption by Neotamias speciosus in the Sierra Nevada of California

Treesearch

Marc D. Meyer; Malcolm P. North; Douglas A. Kelt

2005-01-01

In many western North American forests, prescribed burning and mechanical thinning are widely used to reduce fuels and restore stand conditions after a century of fire suppression. Few studies have followed the relative impacts of these treatments on the production and consumption of truffles in forest ecosystems, particularly in the Sierra Nevada of California. Using...

Genetic studies of Northern Goshawks (Accipiter gentilis): genetic tagging and individual identification from feathers, and determining phylogeography, gene flow and population history for Goshawks in North America

Treesearch

Shelley Bayard de Volo

2008-01-01

The Northern Goshawk (Accipiter gentilis) is a large, highly mobile, mostly nonmigratory and widespread forest raptor. It ranges across the Boreal forests from Alaska to Newfoundland, and south into forests of the Great Lakes, and montane regions of the Appalachian, Cascade, Sierra Nevada, Rocky Mountain, and Sierra Madre Occidental.

Ecological effects of nitrogen deposition in the western United States

USGS Publications Warehouse

Fenn, M.E.; Baron, Jill S.; Allen, E.B.; Rueth, H.M.; Nydick, K.R.; Geiser, L.; Bowman, W.D.; Sickman, J.O.; Meixner, T.; Johnson, D.W.; Neitlich, P.

2003-01-01

In the western United States vast acreages of land are exposed to low levels of atmospheric nitrogen (N) deposition, with interspersed hotspots of elevated N deposition downwind of large, expanding metropolitan centers or large agricultural operations. Biological response studies in western North America demonstrate that some aquatic and terrestrial plant and microbial communities are significantly altered by N deposition. Greater plant productivity is counterbalanced by biotic community changes and deleterious effects on sensitive organisms (lichens and phytoplankton) that respond to low inputs of N (3 to 8 kilograms N per hectare per year). Streamwater nitrate concentrations are elevated in high-elevation catchments in Colorado and are unusually high in southern California and in some chaparral catchments in the southwestern Sierra Nevada. Chronic N deposition in the West is implicated in increased fire frequency in some areas and habitat alteration for threatened species. Between hotspots, N deposition is too low to cause noticeable effects or has not been studied.

Acting Administrator Lightfoot Visits Sierra Nevada Corporation

NASA Image and Video Library

2017-04-06

Acting NASA Deputy Administrator Lesa Roe, left, and acting NASA Administrator Robert Lightfoot, right, listen as Alec Devereaux, a systems engineer with Sierra Nevada Corporation, right, discusses the Flight Control Integration Lab (FCIL), Thursday, April 6, 2017 during a visit to Sierra Nevada Corporation in Louisville, Colo. Sierra Nevada Corporation, with their Dream Chaser Cargo System, was one of three companies to be awarded Commercial Resupply Services (CRS-2) contracts designed to obtain cargo delivery services to the space station, disposal of unneeded cargo, and the return of research samples and other cargo from the station back to NASA. Photo Credit: (NASA/Joel Kowsky)

Comparison of the tropical floras of the Sierra la Madera and the Sierra Madre Occidental, Sonora, Mexico

Treesearch

Thomas R. Van Devender; Gertrudis Yanes-Arvayo; Ana Lilia Reina-Guerrero; Melissa Valenzuela-Yanez; Maria de la Paz Montanez-Armenta; Hugo Silva-Kurumiya

2013-01-01

The floras of the tropical vegetation in the Sky Island Sierra la Madera (SMA) near Moctezuma in northeastern Sonora (30°00’N 109°18’W) and the Yécora (YEC) area in the Sierra Madre Occidental (SMO) in eastern Sonora (28°25’N 109°15”W) were compared. The areas are 175 km apart. Tropical vegetation includes foothills thornscrub (FTS) in both areas and tropical deciduous...

Characteristics and Outcomes of Pediatric Patients With Ebola Virus Disease Admitted to Treatment Units in Liberia and Sierra Leone: A Retrospective Cohort Study.

PubMed

Smit, Michael A; Michelow, Ian C; Glavis-Bloom, Justin; Wolfman, Vanessa; Levine, Adam C

2017-02-01

The clinical and virologic characteristics of Ebola virus disease (EVD) in children have not been thoroughly documented. Consecutive children aged <18 years with real-time polymerase chain reaction (RT-PCR)-confirmed EVD were enrolled retrospectively in 5 Ebola treatment units in Liberia and Sierra Leone in 2014/2015. Data collection and medical management were based on standardized International Medical Corps protocols. We performed descriptive statistics, multivariate logistic regression, and Kaplan-Meier survival analyses. Of 122 children enrolled, the median age was 7 years and one-third were aged <5 years. The female-to-male ratio was 1.3. The most common clinical features at triage and during hospitalization were fever, weakness, anorexia, and diarrhea, although 21% of patients were initially afebrile and 6 patients remained afebrile. Bleeding was rare at presentation (5%) and manifested subsequently in fewer than 50%. The overall case fatality rate was 57%. Factors associated with death in bivariate analyses were age <5 years, bleeding at any time during hospitalization, and high viral load. After adjustment with logistic regression modeling, the odds of death were 14.8-fold higher if patients were aged <5 years, 5-fold higher if the patient had any evidence of bleeding, and 5.2-fold higher if EVD RT-PCR cycle threshold value was ≤20. Plasmodium parasitemia had no impact on EVD outcomes. Age <5 years, bleeding, and high viral loads were poor prognostic indicators of children with EVD. Research to understand mechanisms of these risk factors and the impact of dehydration and electrolyte imbalance will improve health outcomes. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America.

Constraints on the history and topography of the Northeastern Sierra Nevada from a Neogene sedimentary basin in the Reno-Verdi area, Western Nevada

USGS Publications Warehouse

Trexler, James; Cashman, Patricia; Cosca, Michael

2012-01-01

Neogene (Miocene–Pliocene) sedimentary rocks of the northeastern Sierra Nevada were deposited in small basins that formed in response to volcanic and tectonic activity along the eastern margin of the Sierra. These strata record an early phase (ca. 11–10 Ma) of extension and rapid sedimentation of boulder conglomerates and debrites deposited on alluvial fans, followed by fluvio-lacustrine sedimentation and nearby volcanic arc activity but tectonic quiescence, until ~ 2.6 Ma. The fossil record in these rocks documents a warmer, wetter climate featuring large mammals and lacking the Sierran orographic rain shadow that dominates climate today on the eastern edge of the Sierra. This record of a general lack of paleo-relief across the eastern margin of the Sierra Nevada is consistent with evidence presented elsewhere that there was not a significant topographic barrier between the Pacific Ocean and the interior of the continent east of the Sierra before ~ 2.6 Ma. However, these sediments do not record an integrated drainage system either to the east into the Great Basin like the modern Truckee River, or to the west across the Sierra like the ancestral Feather and Yuba rivers. The Neogene Reno-Verdi basin was one of several, scattered endorheic (i.e., internally drained) basins occupying this part of the Cascade intra-arc and back-arc area.

Final Record of Decision/Remedial Action Plan, Nine Sites, Sierra Army Depot, Lassen County, California.

DTIC Science & Technology

1996-10-01

Associates 1-3 0619100396 RD2 Introduction Honey Lake Valley appears to be isolated because no sin-face water flows from the valley. The United...infiltration of precipitation in upland areas and infiltration of stream flow in alluvial fan areas (Handman et al., 1990). Discharge from the...is slightly higher in elevation than the northern portion of the installation. Figure 1.5 indicates that groundwater flow is generally to the north

Motion and Seasickness of Fast Warships

DTIC Science & Technology

2004-10-01

Motion and Seasickness of Fast Warships Riola J.M. (1), Esteban S. (2), Giron-Sierra J.M. (2) & Aranda J. (3) (1) Canal de Experiencias ...5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Canal de Experiencias Hidrodinámicas de ...Bretschneider Sp bability Density of Waves /λ, with H being the wave height (twice the wave a in a seakeeping basin Canal de Experiencias Hid r waves with

101st Sustainment Brigade Supports Operation United Assistance

DTIC Science & Technology

2016-05-17

Africa , particularly affect- ing Guinea, Sierra Leone, and Li- beria. By August 2014, the epidemic had spread so fast that the U.N. de- clared it to be a...deployment of mili- tary forces to West Africa as part of a global response effort. The 101st Sustainment Brigade at Fort Campbell, Kentucky...integration. This article examines the efforts of TF Lifeliner during OUA as the lead U.S. logistics organization in West Africa . TF Lifeliner

Reconnaissance investigation of ground-water supply for Dora Belle Campground, Shaver Lake, California

USGS Publications Warehouse

Davis, G.H.

1957-01-01

At the request of the United States Forest Service, the Ground Water Branch of the United Stated Geological Survey made a reconnaissance of the geologic features and water resources of the Dora Belle Campground in Sierra National Forest on the shore of Shaver Lake, Fresno County, California. Basically, the water-supply problem at Dora Belle Campground is that the present supply obtained from a spring is not adequate to meet the present summer demand, and is of poor quality. Plans call for a considerable increase in camping facilities.. This, it is imperative that the present supply be augmented or, preferably, be replaced entirely. the Forest Service estimated the future peak demand to be about 25,00 gallons per day. On October 28, 1957, the writer examined the are in the company of C. H. Fankboner, Assistant Forest Engineer, Sierra National Forest, and Ben Dix, Construction and Maintenance Foreman, Pine Ridge District. Field work, done on October 28th and 29th, consisted of a brief geologic reconnaissance to determine the rock types and geologic structure, and a hydrologic reconnaissance consisting of a partial inventory of water walls and springs in the vicinity of the campground. A spring box near the western edge of Bell Diamond Meadow was pumped out with a Forest Service pump truck to determine its rate of recovery and potential production.

Alteration mineral mapping for iron prospecting using ETM+ data, Tonkolili iron field, northern Sierra Leone

NASA Astrophysics Data System (ADS)

Mansaray, Lamin R.; Liu, Lei; Zhou, Jun; Ma, Zhimin

2013-10-01

The Tonkolili iron field in northern Sierra Leone has the largest known iron ore deposit in Africa. It occurs in a greenstone belt in an Achaean granitic basement. This study focused mainly on mapping areas with iron-oxide and hydroxyl bearing minerals, and identifying potential areas for haematite mineralization and banded iron formations (BIFs) in Tonkolili. The predominant mineral assemblage at the surface (laterite duricrust) of this iron field is haematitegoethite- limonite ±magnetite. The mineralization occurs in quartzitic banded ironstones, layered amphibolites, granites, schists and hornblendites. In this study, Crosta techniques were applied on Enhanced Thematic Mapper (ETM+) data to enhance areas with alteration minerals and target potential areas of haematite and BIF units in the Tonkolili iron field. Synthetic analysis shows that alteration zones mapped herein are consistent with the already discovered magnetite BIFs in Tonkolili. Based on the overlaps of the simplified geological map and the remote sensing-based alteration mineral maps obtained in this study, three new haematite prospects were inferred within, and one new haematite prospect was inferred outside the tenement boundary of the Tonkolili exploration license. As the primary iron mineral in Tonkolili is magnetite, the study concludes that, these haematite prospects could also be underlain by magnetite BIFs. This study also concludes that, the application of Crosta techniques on ETM+ data is effective not only in mapping iron-oxide and hydroxyl alterations but can also provide a basis for inferring areas of potential iron resources in Algoma-type banded iron formations (BIFs), such as those in the Tonkolili field.

Response of two terrestrial salamander species to spring burning in the Sierra Nevada, California

Treesearch

Karen E. Bagne; Kathryn L. Purcell

2009-01-01

Terrestrial salamanders may be vulnerable to prescribed fire applications due to their moist, permeable skin and limited mobility. We present data collected on terrestrial salamander populations in a ponderosa pine-dominated forest in the Sierra Nevada where fire was applied in the spring. Two species, Sierra ensatina (Ensatina eschscholtzi platensis...

My Great Migration from Sierra Leone

ERIC Educational Resources Information Center

Harvard Educational Review, 2011

2011-01-01

This article presents the author's personal narrative as an immigrant from Sierra Leone who has undergone so many challenges in life and ended up turning all these obstacles into opportunities. In this article, the author describes his life growing up in Sierra Leone, his first experience of the horrors of war, his life as a student, and his dream…

78 FR 2391 - Sierra Pacific Power Company; Notice of Initiation of Proceeding and Refund Effective Date

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-11

... Power Company; Notice of Initiation of Proceeding and Refund Effective Date On December 31, 2012, the... reasonableness of the proposed transmission and ancillary service rates by Sierra Pacific Power Company. Sierra Pacific Power Company, 141 FERC ] 61,266 (2012). The refund effective date in Docket No. EL13-29-000...

Building effective international, multicultural alliances for restoration of ejido forests in the Sierra Madre Occidental

Treesearch

Randall Gingrich

2005-01-01

Effective NGO-government-community alliances are the key to overcoming the complex socio-political obstacles to conservation in the Sierra Madre Occidental. Over 80 percent of the territory in the Sierra Madre Occidental is communally owned. Agrarian and other socio-economic conditions present both opportunities and obstacles to conservation. Conservation,...

Fire in the Sierra Nevada

Treesearch

Carl N. Skinner; Scott L. Stephens

2004-01-01

Fire has been described as both a major ecological force necessary for long-term functioning of Sierra Nevada ecosystems and as one of the greatest threats to human and natural resources (SNEP 1996a). Fire has shaped the terrestrial ecosystems of the Sierra Nevada for millennia. Before the mid-1800s, fires generally were frequent and mostly of low to moderate intensity...

Distance, accessibility and costs. Decision-making during childbirth in rural Sierra Leone: A qualitative study.

PubMed

Treacy, Laura; Bolkan, Håkon A; Sagbakken, Mette

2018-01-01

Sierra Leone has one of the highest maternal mortality ratios in the world. Efforts to reduce maternal mortality have included initiatives to encourage more women to deliver at health facilities. Despite the introduction of the free health care initiative for pregnant women, many women still continue to deliver at home, with few having access to a skilled birth attendant. In addition, inequalities between rural and urban areas in accessing and utilising health facilities persist. Further insight into how and why women make decisions around childbirth will help guide future plans and initiatives in improving maternal health in Sierra Leone. The objective of this study was to explore the perceptions and decision-making processes of women and their communities during childbirth in rural Sierra Leone. Data were collected through seven focus group discussions and 22 in-depth interviews with recently pregnant women and their community members in two rural villages. Data were analysed using systematic text condensation. Findings revealed that decision-making processes during childbirth are dynamic, intricate and need to be understood within the broader social context that they take place. Factors such as distance and lack of transport, perceived negative behaviour of hospital staff, direct and indirect financial obstacles, as well as the position of women in society all interact and influence how and what decisions are made. Pregnant women face multiple interacting vulnerabilities that influence their healthcare-seeking decisions during pregnancy and childbirth. Future initiatives to improve access and utilisation of safe healthcare services for pregnant women need to be based on adequate knowledge of structural constraints and health inequities that affect women in rural Sierra Leone.

South African Ebola diagnostic response in Sierra Leone: A modular high biosafety field laboratory

PubMed Central

Jansen van Vuren, Petrus; Meier, Gunther H.; le Roux, Chantel; Conteh, Ousman S.; Kemp, Alan; Fourie, Cardia; Naidoo, Prabha; Naicker, Serisha; Ohaebosim, Phumza; Storm, Nadia; Hellferscee, Orienka; Ming Sun, Lisa K.; Mogodi, Busisiwe; Prabdial-Sing, Nishi; du Plessis, Desiree; Greyling, Deidre; Loubser, Shayne; Goosen, Mark; McCulloch, Stewart D.; Scott, Terence P.; Moerdyk, Alexandra; Dlamini, Wesley; Konneh, Kelfala; Kamara, Idrissa L.; Sowa, Dauda; Sorie, Samuel; Kargbo, Brima; Madhi, Shabir A.

2017-01-01

Background In August 2014, the National Institute for Communicable Diseases (NICD) in South Africa established a modular high-biosafety field Ebola diagnostic laboratory (SA FEDL) near Freetown, Sierra Leone in response to the rapidly increasing number of Ebola virus disease (EVD) cases. Methods and findings The SA FEDL operated in the Western Area of Sierra Leone, which remained a “hotspot” of the EVD epidemic for months. The FEDL was the only diagnostic capacity available to respond to the overwhelming demand for rapid EVD laboratory diagnosis for several weeks in the initial stages of the EVD crisis in the capital of Sierra Leone. Furthermore, the NICD set out to establish local capacity amongst Sierra Leonean nationals in all aspects of the FEDL functions from the outset. This led to the successful hand-over of the FEDL to the Sierra Leone Ministry of Health and Sanitation in March 2015. Between 25 August 2014 and 22 June 2016, the laboratory tested 11,250 specimens mostly from the Western Urban and Western Rural regions of Sierra Leone, of which 2,379 (21.14%) tested positive for Ebola virus RNA. Conclusions The bio-safety standards and the portability of the SA FEDL, offered a cost-effective and practical alternative for the rapid deployment of a field-operated high biocontainment facility. The SA FEDL teams demonstrated that it is highly beneficial to train the national staff in the course of formidable disease outbreak and accomplished their full integration into all operational and diagnostic aspects of the laboratory. This initiative contributed to the international efforts in bringing the EVD outbreak under control in Sierra Leone, as well as capacitating local African scientists and technologists to respond to diagnostic needs that might be required in future outbreaks of highly contagious pathogens. PMID:28628619

South African Ebola diagnostic response in Sierra Leone: A modular high biosafety field laboratory.

PubMed

Paweska, Janusz T; Jansen van Vuren, Petrus; Meier, Gunther H; le Roux, Chantel; Conteh, Ousman S; Kemp, Alan; Fourie, Cardia; Naidoo, Prabha; Naicker, Serisha; Ohaebosim, Phumza; Storm, Nadia; Hellferscee, Orienka; Ming Sun, Lisa K; Mogodi, Busisiwe; Prabdial-Sing, Nishi; du Plessis, Desiree; Greyling, Deidre; Loubser, Shayne; Goosen, Mark; McCulloch, Stewart D; Scott, Terence P; Moerdyk, Alexandra; Dlamini, Wesley; Konneh, Kelfala; Kamara, Idrissa L; Sowa, Dauda; Sorie, Samuel; Kargbo, Brima; Madhi, Shabir A

2017-06-01

In August 2014, the National Institute for Communicable Diseases (NICD) in South Africa established a modular high-biosafety field Ebola diagnostic laboratory (SA FEDL) near Freetown, Sierra Leone in response to the rapidly increasing number of Ebola virus disease (EVD) cases. The SA FEDL operated in the Western Area of Sierra Leone, which remained a "hotspot" of the EVD epidemic for months. The FEDL was the only diagnostic capacity available to respond to the overwhelming demand for rapid EVD laboratory diagnosis for several weeks in the initial stages of the EVD crisis in the capital of Sierra Leone. Furthermore, the NICD set out to establish local capacity amongst Sierra Leonean nationals in all aspects of the FEDL functions from the outset. This led to the successful hand-over of the FEDL to the Sierra Leone Ministry of Health and Sanitation in March 2015. Between 25 August 2014 and 22 June 2016, the laboratory tested 11,250 specimens mostly from the Western Urban and Western Rural regions of Sierra Leone, of which 2,379 (21.14%) tested positive for Ebola virus RNA. The bio-safety standards and the portability of the SA FEDL, offered a cost-effective and practical alternative for the rapid deployment of a field-operated high biocontainment facility. The SA FEDL teams demonstrated that it is highly beneficial to train the national staff in the course of formidable disease outbreak and accomplished their full integration into all operational and diagnostic aspects of the laboratory. This initiative contributed to the international efforts in bringing the EVD outbreak under control in Sierra Leone, as well as capacitating local African scientists and technologists to respond to diagnostic needs that might be required in future outbreaks of highly contagious pathogens.

Population size, survival, growth, and movements of Rana sierrae

USGS Publications Warehouse

Fellers, Gary M.; Kleeman, Patrick M.; Miller, David A. W.; Halstead, Brian J.; Link, William

2013-01-01

Based on 2431 captures of 757 individual frogs over a 9-yr period, we found that the population of R. sierrae in one meadow–stream complex in Yosemite National Park ranged from an estimated 45 to 115 adult frogs. Rana sierrae at our relatively low elevation site (2200 m) grew at a fast rate (K = 0.73–0.78), had high overwintering survival rates (44.6–95%), lived a long time (up to 16 yr), and tended to be fairly sedentary during the summer (100% minimum convex polygon annual home ranges of 139 m2) but had low year-to-year site fidelity. Even though the amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) has been present in the population for at least 13 yr, there was no clear downward trend as might be expected from reports of R. sierrae population declines associated with Bd or from reports of widespread population decline of R. sierrae throughout its range.

Spatial and seasonal patterns of particulate matter less than 2.5 microns in the Sierra Nevada Mountains, California

Treesearch

Ricardo Cisneros; Don Schweizer; Haiganoush Preisler; Deborah H. Bennett; Glenn Shaw; Andrzej Bytnerowicz

2014-01-01

This paper presents particulate matter data collected in the California southern Sierra Nevada Mountains (SNM) during 2002 to 2009 from the Central Valley (elevation 91 m) into the SNM (elevation 2,598 m). Annual average concentrations of particles smaller than 2.5 µm in diameter (PM2.5) for all sites during this study ranged from 3.1 to 22.2 µg...

Fire-scar formation in Jeffrey pine - mixed conifer forests in the Sierra San Pedro Martir, Mexico

Treesearch

Scott L. Stephens; Danny L. Fry; Brandon M. Collins; Carl N. Skinner; Ernesto Franco-Vizcaino; Travis J. Freed

2010-01-01

Little is known about the probability of fire-scar formation. In this study, we examined all mixed conifer trees for fire-scar formation in a 16 ha watershed that burned as part of a 2003 wildfire in Sierra San Pedro Ma´rtir National Park (SSPM), Mexico. In addition, we examine the probability of fire-scar formation in relation to the previous fire interval in forests...

Effects of Selective Logging on Birds in the Sierra de Coalcoman, Sierra Madre del Sur, Michoacan, Western Mexico

Treesearch

Jose Fernando Villaseñor; Neyra Sosa; Laura Villaseñor

2005-01-01

In order to determine the effects of selective logging on pine-oak forest?s bird communities in central-western Mexico, we gathered information through 10-min point counts in plots without wood extraction and sites logged at different times in the past (1, 4, and 8 years). We did not find evidences to argue for effects of logging on bird communities; the study plots...

Geochronology and Structural Studies in the Northern Ritter Range: Implications for the Tectonic History of Mesozoic Sierra Nevada Arc

NASA Astrophysics Data System (ADS)

Black, C. J.; Whitesides, A. S.; Anderson, J. L.; Culbert, K. N.; Vandeveer, M.; Cox, I. V.; Cardamone, J.; Torrez, G.; Quirk, M.; Memeti, V.; Cao, W.; Paterson, S. R.

2010-12-01

Field mapping in the Northern Ritter Range pendant, central Sierra Nevada reveals four different lithotectonic units. Unit 1, east of Gem Lake, consists of Paleozoic passive margin metasedimentary rocks. Unit 2 lies unconformably above and west and is composed of Late Triassic to Middle Jurassic rhyolitic to andesitic, clast-rich, metavolcanic rocks that are typically massive, thick bedded, relatively homogeneous. Breccias and millimeter sized plagioclase phenocrysts are common in these beds. Unit 3 west of and structurally higher than unit 2 and is composed of thinly bedded metavolcanic and metasedimentary rocks of same age. Unit 2 and Unit 3 both steeply dipping and NW striking bedding and bedding parallel foliations. Unit 4 is composed of less deformed, Cretaceous, rhyolitic to andesitic breccias and rare volcaniclastic units that are west of and unconformably above unit 3. All units are now separated by faults. The Cretaceous dextral, oblique Gem Lake shear zone reactivated the uncomformity between units 1 and 2. West of the shear zone, both the shearing and strain intensity gradually decrease, the later from >60% to 40% shortening. Unit 2 and 3 are separated by a thrust fault, with local pseudotachelite now overprinted by ductile deformation. Unit 3 and 4 are now juxtaposed along a deformed unconformity west of which strain decreases to shortening values > 30%. These host rocks are intruded by granitic to dioritic plutons preserving a wide range of internal characteristics and emplacement styles. The oldest pluton is the 100 Ma Rush Creek Granodiorite, which intruded into unit 2. The Kuna Crest (KC, 94.6 Ma), the Waugh Lake (WL, 93.6 Ma), and the Thousand Island Lake leucogranodiorites (TIL) (~94 Ma) all intrude into the unit 3. The TIL cut the unconformity between units 3 and 4. The WL pluton is possibly cut by movement between units 2 and 3. The typically NW striking steeply dipping bedding in host rock units is dramatically deflected to EW orientations along the SW margin of the KC lobe. Within the nearby WL Granodiorite, hundreds of andesitic host rock blocks, some up to hundred meter lengths suggest that stoping was an important emplacement process. Migmatitic zones occur along several pluton margins. Our observations are consistent with aspects of the Tobisch et al. (2000) paper suggesting early brittle thrusting led to rotation of beds to steep dips. However our results indicate that beds were already at near vertical dips prior to ductile shortening and well before pluton emplacement. And although regional downward flow of extrusive volcanics has certainly occurred we see evidence against previous suggestions that this downward flow was localized in pluton aureoles as plutons typically cut discordantly across already steeply dipping beds and in turn are deformed by the younger ductile deformation. Although ductile shortening may play a minor role in rotation of beds, much of the ductile deformation had to occur after beds were steeply dipping as the 100-93.5 m.y. plutons have fabrics that are continuous with ductile deformation in the host rocks.

Non-Governmental Organizations in Africa: The Leonenet Street Children Project in Sierra Leone

ERIC Educational Resources Information Center

Hinton, Samuel

2005-01-01

The purpose of this paper is to provide snapshots of observations, interventions, and processes in the day to day working of a child charity in Sierra Leone. There were 114 local and 49 overseas funded Non Governmental Organizations (NGOs) in Sierra Leone in 2002. The Leonenet Street Children Project was founded in 1996 by the membership of the…

Sampling affects the detection of genetic subdivision and conservation implications for fisher in the Sierra Nevada

Treesearch

Jody M. Tucker; Michael K. Schwartz; Richard L. Truex; Samantha M. Wisely; Fred W. Allendorf

2014-01-01

The small population of fisher (Pekania pennanti) in the southern Sierra Nevada is completely geographically and genetically isolated putting it at increased risk of extinction. Previous research using a clustered sampling scheme found a high amount of genetic subdivision within the southern Sierra Nevada population hypothesized to be caused by the Kings River Canyon....

Prediction of periodic basal area increment for young-growth mixed conifers in sierra Nevada

Treesearch

Leroy K. Dolph

1988-01-01

Mixed-conifer forests are the largest vegetation type in California, covering more than 13 million acres (Barbour and Major 1977). This type, the Sierra Nevada Mixed Conifer (Society of American Foresters Forest cover type 243, Tappeiner 1980) dominates mid-elevations of the Sierra Nevada's western slopes. The extent of the mixed-conifer type and the amount of...

Shorthair meadows in the high Sierra Nevada...an hypothesis of their development

Treesearch

Raymond D. Ratliff

1973-01-01

Bands of shorthair meadow are found around lakes in the high Sierra Nevada of California. A hypothesis, based on observations in the Kings Canyon National Park, to explain the development of these meadows is offered: Boulders form the foundation upon which American-laurel, Sierra bilberry, and moss combine to produce thick mats. The lower layers of the mats are...

Nitrogen dynamics of spring-fed wetland ecosystems of the Sierra Nevada foothills oak woodland

Treesearch

Randall D. Jackson; Barbara Allen-Diaz

2002-01-01

Spring-fed wetlands are small, highly productive, patchy ecosystems nested within the oak woodland/annual grassland matrix of the Sierra Nevada foothills. In an effort to place these wetlands in a landscape context, we described seasonal variation (1999-2000 growing season) in nitrogen cycling parameters at 6 spring-fed wetland sites of the Sierra Nevada foothill oak...

Research Brief: Impacts of Extreme Fires in the Sierra Nevada

Treesearch

Jonathan Long

2014-01-01

Scientists from PSW considered the effects of severe wildfire in the Sierra Nevada and southern Cascade Range in a recent synthesis that focused on promoting resiliency of forests and the societies connected to them. Fire is indispensable to maintaining the health and productivity of most forests in the Sierra Nevada, and fires can also rejuvenate aquatic systems by...

A new species of Bolitoglossa (Amphibia, Caudata) from the Sierra de Juárez, Oaxaca, Mexico

PubMed Central

Rovito, Sean M.; Parra-Olea, Gabriela; Lee, Dana; Wake, David B.

2012-01-01

Abstract We describe a new species of Bolitoglossa (Nanotriton) from the Sierra de Juárez and Sierra Mixe of Oaxaca, Mexico. Bolitoglossa chinanteca sp. n. is distinguished from the three other species in the subgenus Nanotriton by its more robust body, by having substantial numbers of maxillary teeth and differences in relative head width, foot width, and limb length. The new species occurs in sympatry with Bolitoglossa (Nanotriton) rufescens at the type locality. The description of another species of salamander from the Sierra de Juárez is noteworthy, given the already high plethodontid salamander species richness of the region. PMID:22577313

Ebola Virus Disease--Sierra Leone and Guinea, August 2015.

PubMed

Hersey, Sara; Martel, Lise D; Jambai, Amara; Keita, Sakoba; Yoti, Zabulon; Meyer, Erika; Seeman, Sara; Bennett, Sarah; Ratto, Jeffrey; Morgan, Oliver; Akyeampong, Mame Afua; Sainvil, Schabbethai; Worrell, Mary Claire; Fitter, David; Arnold, Kathryn E

2015-09-11

The Ebola virus disease (Ebola) outbreak in West Africa began in late 2013 in Guinea (1) and spread unchecked during early 2014. By mid-2014, it had become the first Ebola epidemic ever documented. Transmission was occurring in multiple districts of Guinea, Liberia, and Sierra Leone, and for the first time, in capital cities (2). On August 8, 2014, the World Health Organization (WHO) declared the outbreak to be a Public Health Emergency of International Concern (3). Ministries of Health, with assistance from multinational collaborators, have reduced Ebola transmission, and the number of cases is now declining. While Liberia has not reported a case since July 12, 2015, transmission has continued in Guinea and Sierra Leone, although the numbers of cases reported are at the lowest point in a year. In August 2015, Guinea and Sierra Leone reported 10 and four confirmed cases, respectively, compared with a peak of 526 (Guinea) and 1,997 (Sierra Leone) in November 2014. This report details the current situation in Guinea and Sierra Leone, outlines strategies to interrupt transmission, and highlights the need to maintain public health response capacity and vigilance for new cases at this critical time to end the outbreak.

Sinfonevada: Dataset of Floristic diversity in Sierra Nevada forests (SE Spain)

PubMed Central

Pérez-Luque, Antonio Jesús; Bonet, Francisco Javier; Pérez-Pérez, Ramón; Rut Aspizua; Lorite, Juan; Zamora, Regino

2014-01-01

Abstract The Sinfonevada database is a forest inventory that contains information on the forest ecosystem in the Sierra Nevada mountains (SE Spain). The Sinfonevada dataset contains more than 7,500 occurrence records belonging to 270 taxa (24 of these threatened) from floristic inventories of the Sinfonevada Forest inventory. Expert field workers collected the information. The whole dataset underwent a quality control by botanists with broad expertise in Sierra Nevada flora. This floristic inventory was created to gather useful information for the proper management of Pinus plantations in Sierra Nevada. This is the only dataset that shows a comprehensive view of the forest flora in Sierra Nevada. This is the reason why it is being used to assess the biodiversity in the very dense pine plantations on this massif. With this dataset, managers have improved their ability to decide where to apply forest treatments in order to avoid biodiversity loss. The dataset forms part of the Sierra Nevada Global Change Observatory (OBSNEV), a long-term research project designed to compile socio-ecological information on the major ecosystem types in order to identify the impacts of global change in this area. PMID:24843285

Long-lived Control of Sierras Pampeanas Ranges on Andean Foreland Basin Evolution Revealed by Coupled Low-temperature Thermochronology and Sedimentology

NASA Astrophysics Data System (ADS)

Stevens Goddard, A.; Carrapa, B.; Larrovere, M.; Aciar, R. H.

2017-12-01

The Sierras Pampeanas ranges of west-central Argentina (28º- 31ºS) are a classic example of thick-skinned style basement block uplifts. The style and timing of uplift in these mountain ranges has widely been attributed to the onset of flat-slab subduction in the middle to late Miocene. However, the majority of low-temperature thermochronometers in the Sierras Pampeanas have much older cooling dates. Thermal modeling derived from new low-temperature thermochronometers in Sierra de Velasco, one of the highest relief (> 4 km) mountains in the Sierras Pampeanas, suggest that the rocks in these ranges have been at near-surface temperatures (< 50ºC) since the Paleozoic. Reheating to temperatures between 80ºC and 100ºC occurred during late Cretaceous rifting and may be partially attributed to a temporary elevation of the regional geothermal gradient. Cooling attributed to late Miocene exhumation, and coincident with estimates of the onset of flat-slab subduction, contributed to modern relief, but cannot explain all of the modern topography. We compare the results from low-temperature thermochronology with the regional sedimentary basin record to confirm that paleorelief plausibly controlled sedimentation patterns throughout the development of the Cenozoic Andean foreland basin at these latitudes. We propose that the history of long-lived topography illustrated in Sierra de Velasco can be expanded to other ranges in the Sierras Pampeanas by integrating multiple data sets.

Viraemia and Ebola virus secretion in survivors of Ebola virus disease in Sierra Leone: a cross-sectional cohort study.

PubMed

Green, Edward; Hunt, Luke; Ross, J C Gareth; Nissen, Nina Marie; Curran, Tanya; Badhan, Anjna; Sutherland, Katherine A; Richards, Jade; Lee, James S; Allen, Samuel H; Laird, Steven; Blackman, Mandy; Collacott, Ian; Parker, Paul A; Walbridge, Andrew; Phillips, Rebecca; Sellu, Sia Jammie; Dama, Agnes; Sheriff, Alpha Karim; Zombo, Joseph; Ngegba, Doris; Wurie, Alieh H; Checchi, Francesco; Brooks, Timothy J

2016-09-01

In survivors of Ebola virus disease, clinical sequelae including uveitis, arthralgia, and fatigue are common and necessitate systematic follow-up. However, the infection risk to health-care providers is poorly defined. Here we report Ebola virus RT-PCR data for body site and fluid samples from a large cohort of Ebola virus survivors at clinic follow-up. In this cross-sectional cohort study, consecutive survivors of Ebola virus disease attending Kerry Town survivor clinic (Freetown, Sierra Leone), who had been discharged from the Kerry Town Ebola treatment unit, were invited to participate. We collected and tested axillary, blood, conjunctival, forehead, mouth, rectal, semen, urine, and vaginal specimens for presence of Ebola virus using RT-PCR. We regarded samples to be positive for Ebola virus disease if the cycle threshold was 40 or lower. We collected demographic data from survivors of their age, sex, time since discharge from the treatment unit, and length of acute admission in the Ebola treatment unit using anonymised standard forms. Between April 2, and June 16, 2015, of 151 survivors of Ebola virus disease invited to participate, 112 (74%) provided consent. The median age of participants was 21·5 years (IQR 14-31·5) with 34 (30%) participants younger than 16 years. 50 (45%) of 112 participants were male. We tested a total of 555 specimens: 103 from the axilla, 93 from blood, 92 from conjunctiva, 54 from forehead, 105 from mouth, 17 from the rectum, one from semen, 69 from urine, and 21 from the vagina. The median time from Ebola treatment unit discharge to specimen collection was 142 days (IQR 127-159). 15 participants had a total of 74 swabs taken less than 100 days from discharge. The semen sample from one participant tested positive for Ebola virus at 114 days after discharge from the treatment unit; specimens taken from the axilla, blood, conjunctiva, forehead, mouth, rectum, and urine of the same participant tested negative. All specimens from the other 111 participants tested negative. Patients recovering from Ebola virus disease who do not meet the case definition for acute disease pose a low infection risk to health-care providers 6 weeks after clearance of viraemia. Personal protective equipment after this time might be limited to standard barrier precautions, unless contact with fluids from sanctuary sites is envisaged. Save the Children International, Public Health England. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Eastern delta-fan deposits on the Granada Basin as tectonic indicators of the Sierra Nevada uplift (Betic Cordillera, South Spain)

NASA Astrophysics Data System (ADS)

Roldán, Francisco Javier; Azañon, Jose Miguel; Mateos, Rosa Maria

2014-05-01

A geological mapping in detail of the Eastern sector of the Granada Basin (South Spain) reveals two different groups of Gilbert delta-fans related to the Sierra Nevada uplift. The first group, in the southern part and with a surface of 6 km2, has three major coarsening-upward sequences. They are composed of very coarse deposits, those of conglomerates, sands and silts. Progradational strata units to the basin have been observed. The dominantly fluvial facies association has locally developed shallow marine foreset deposits (partially with reef colonization) as well as topset red soils (Dabrio, et al., 1978; Braga et a., 1990; García-García, et al., 1999) . All the sequences are discordant over marine facies (calcarenites) dated over 8,26 Ma (Late Tortonian). The second group, in the northern part and with an extension of 12 km2, has similar characteristics, but some of the boulders have ostreids and lamellibranchs species which reveal their former position in a previous marine environment. The Sierra Nevada uplift caused the remobilization of these boulders, being transported by debris-flow inside the delta-fan bodies (García-García, et al., 2006). The dating of ostreids shells with Sr techniques reveals ages over 7,13, 6,61 and 5,45 Ma, from the lower to the upper delta-fan deposits, which are related to the three main sequences observed and with three major tectonic pulses during the Late Miocene. These interpretations are in agreement with apatite fision-track studies carried out in some boulders of these coarse delta-fan deposits (Clark and Dempster, 2013). They reveal a detailed record of Neogene denudation from the Sierra Nevada basement and with uplift periods between 5,45Ma- 2 Ma. The latest pulses affected the delta-fan sediments given rise to new fan systems in the Granada Basin (Alhambra Formation). The thoroughly study of the Miocene delta-fan sediments allows us to conclude that they were related to a sin-sedimentary tectonic activity linked to the Sierra Nevada uplift and with original NE-SW normal left-lateral fault system associated with a compatible ESE-WNW normal fault system. The asymmetrical morphologies of the two delta-fan bodies confirm this configuration as tectonic induced deposits. References Braga, J.C., Martín, J.M. and Alcalá, B. (1990). Coral reefs in coarse-terrigenous sedimentary environments (Upper Tortonian, Granada Basin, southern Spain). Sedimentary Geology, 66, pp 135-150. Clark, S.J.P.and Dempster, T.J. (2009). The record of tectonic denudation and erosion in an emerging orogen: an apatite fission-track study of the Sierra Nevada, southern Spain. Journal of the Geological Society, London, Vol. 166, pp. 87-100. Dabrio, C.J., Fernández, J., Peña, J., Ruíz-Bustos, A. y Sanz de Galdeano, C. (1978). Rasgos sedimentarios de los conglomerados miocénicos del borde noreste de la Depresión de Granada. Estudios Geológicos, 34, pp 89-97. García-García, F., Fernández, J., Viseras, C. and Soria, J.M. (2006). Architecture and sedimentary facies evolution in a delta stack controlled by fault growth (Betic Cordillera, southern Spain, late Tortonian). Sedimentary Geology, 185, pp. 79-92. García-García, F., Viseras, C. and Fernández, J. (1999). Organización secuencial de abanicos deltaicos controlados por la tectónica (Tortoniense superior, cuenca de Granada, Cordillera Bética). Rev. Soc. Geol. España, 12 (2): 199-208.

Assessment on the Knowledge and Reported Practices of Women on Maternal and Child Health in Rural Sierra Leone: A Cross-Sectional Survey

PubMed Central

Kanu, Joseph Sam; Tang, Yuan; Liu, Yawen

2014-01-01

Background Globally, Sierra Leone is ranked among the countries with the worst maternal and child health indicators. The mortality of women and children is significantly higher compared with other developing countries. The death of women and children can be prevented by simple cost-effective community-based interventions. The aim of this present study was to learn the knowledge levels of women on maternal and child health, and treatment-seeking and preventive behaviours in rural Sierra Leone and provide appropriate suggestions for policy makers. Moreover, the study also aimed to evaluate the effect of a husband’s involvement on health knowledge and practices of women in rural Sierra Leone. Methods Women with at least a child of five years or below were interviewed in their households through a structured questionnaire. Characteristics of the households and of the respondents were collected and the number of correct answers given to the health knowledge and practice questions and their percentage distributions were tabulated and an overall health knowledge score was calculated. Results The mean score of the derived overall health-related knowledge was 61.6% (maximum of 91% and a minimum of 18%) with a standard deviation of 14.7% and a median of 63.3%. Multivariable regression analyses showed education and number of pregnancies are associated with knowledge score, with significantly improved health knowledge scores amongst those who accessed higher education. There were some inappropriate practices in hygiene and sanitation. However, vaccination coverage was high with almost 100% coverage for BCG. Conclusions Based on the findings of this study, women’s knowledge on maternal and child health care are inadequate in rural Sierra Leone. Health promotion activities focusing on prevention of diarrhoea, malaria and pneumonia, improvement in health-related knowledge on pregnancy, delivery, neonatal care and environmental sanitation would be invaluable. PMID:25166504

From the Sierra to the Cities: The Urban Campaign of the Shining Path

DTIC Science & Technology

1992-01-01

AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS( ES ) Rand Corporation,1776 Main Street...PO Box 2138,Santa Monica,CA,90407-2138 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS( ES ) 10...indeed turned out to be correct. See " Que pasa con Sendero Luminoso?" QueHacer, No. 29, June 1984, pp. 34-38. 4Richard Webb and Graciela Fernandez

The Role of United States Army Special Forces in Operation NOBEL OBELISK

DTIC Science & Technology

2001-06-01

This thesis will examine U.S. Special Forces contributions to Operation NOBEL OBELISK, a Marine- led joint NEO in Sierra Leone in 1997. It is further...success of Joint Task Force NOBEL OBELISK. This operation led to the eventual safety of in excess of 2,500 civilians. Many of those civilians were... led many observers, both within and outside the country, to be optimistic about the future of democracy and the rule of law.”6 Unfortunately, twenty

Production of Optical Quality Free Standing Diamond Wafer

DTIC Science & Technology

2008-05-19

Title : Production of Optical Quality Free Standing Diamond Wafer Prime Contractor : Onyx Optics, Inc. 6551 Sierra Lane Dublin, Ca 94568...www.onyxoptics.com Program Manager : Helmuth Meissner Onyx Optics, Inc. 6551 Sierra Lane Dublin, CA 94568 Email: hmeissner@onyxoptics.com Ph: 925...PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Onyx Optics, Inc. 6551 Sierra Lane Dublin, Ca 94568 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING

A preliminary floristic inventory in the Sierra de Mazatan, Municipios of Ures and Mazatan, Sonora, Mexico

Treesearch

Jose Jesus Sanchez-Escalante; Manuel Espericueta-Betancourt; Reyna Amanda Castillo-Gamez

2005-01-01

Presently, the flora of the Sierra de Mazatán contains 357 species of vascular plants distributed in 248 genera and 80 families. The families with the most species are Asteraceae (48), Fabaceae (45), Poaceae (28), Euphorbiaceae (18), and Acanthaceae, Cactaceae, Scrophulariaceae, and Solanaceae (11 each). The results show that the flora of the Sierra de Mazat...

Summer evapotranspiration trends as related to time after logging of forests in Sierra Nevada

Treesearch

Robert R. Ziemer

1964-01-01

Abstract - The quantity of summer soil moisture lost from logged forest openings was related to the length of time since the creation of the opening, in the subalpine forest zone of the Sierra Nevada west side, near the Central Sierra Snow Laboratory, California, at an elevation of 6000 to 7000 feet. Soil moisture depletion was measured in forest openings which were...

Increasing elevation of fire in the Sierra Nevada and implications for forest change

Treesearch

Mark W. Schwartz; Nathalie Butt; Christopher R. Dolanc; Andrew Holguin; Max A. Moritz; Malcolm P. North; Hugh D. Safford; Nathan L. Stephenson; James H. Thorne; Phillip J. van Mantgem

2015-01-01

Fire in high-elevation forest ecosystems can have severe impacts on forest structure, function and biodiversity. Using a 105-year data set, we found increasing elevation extent of fires in the Sierra Nevada, and pose five hypotheses to explain this pattern. Beyond the recognized pattern of increasing fire frequency in the Sierra Nevada since the late 20th century, we...

Sierra/SolidMechanics 4.48 Capabilities in Development.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plews, Julia A.; Crane, Nathan K; de Frias, Gabriel Jose

This document is a user's guide for capabilities that are not considered mature but are available in Sierra/SolidMechanics (Sierra/SM) for early adopters. The determination of maturity of a capability is determined by many aspects: having regression and verification level testing, documentation of functionality and syntax, and usability are such considerations. Capabilities in this document are lacking in one or many of these aspects.

Preliminary flora of the Sierra Bacadehuachi, Sonora, Mexico

Treesearch

Thomas R. Van Devender; Ana Lilia Reina-Guerrero; George M. Ferguson; George Yatskievych; Beatriz E. Loyola-Reina; Gertrudis Yanes-Arvayo; Maria de la Paz Montanez-Armenta; John L. Anderson; Stephen F. Hale; Sky Jacobs

2013-01-01

The Sierra Bacadéhuachi in east-central Sonora is the westernmost mountain range in the Sierra Madre Occidental (SMO), located east of Bacadéhuachi, Municipio de Bacadéhuachi, 34 km east of the Chihuahua border, and 165 km south of the Arizona border. The vegetation ranges from lowland foothills thornscrub up through desert grassland to oak woodland and pine-oak forest...

Drill-hole data, drill-site geology, and geochemical data from the study of Precambrian uraniferous conglomerates of the Medicine Bow Mountains and Sierra Madre of southeastern Wyoming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karlstrom, K.E.; Houston, R.S.; Schmidt, T.G.

1981-02-01

This volume is presented as a companion to Volume 1: The Geology and Uranium Potential of Precambrian Conglomerates in the Medicine Bow Mountains and Sierra Madre of Southeastern Wyoming; and to Volume 3: Uranium Assessment for Precambrian Pebble Conglomerates in Southeastern Wyoming. Volume 1 summarized the geologic setting and geologic and geochemical characteristics of uranium-bearing conglomerates in Precambrian metasedimentary rocks of southeastern Wyoming. Volume 3 is a geostatistical resource estimate of U and Th in quartz-pebble conglomerates. This volume contains supporting geochemical data, lithologic logs from 48 drill holes in Precambrian rocks of the Medicine Bow Mountains and Sierra Madre,more » and drill site geologic maps and cross-sections from most of the holes.« less

New control system for the 1.5m and 0.9m telescopes at Sierra Nevada Observatory

NASA Astrophysics Data System (ADS)

Costillo, Luis P.; Ramos, J. Luis; Ibáñez, J. Miguel; Aparicio, Beatriz; Herránz, Miguel; García, Antonio J.

2006-06-01

The Sierra Nevada Observatory (Granada, Spain) has a number of telescopes. Our study will focus on two Nasmyth telescopes with apertures of 1.5m and 0.9m and an equatorial mount. The system currently installed to control these telescopes is a 1995 centralized VME module. However, given the problems which have arisen due to the number of wires and other complications, we have decided to change this control module. We will control each telescope with a distributed control philosophy, using a serial linear communication bus between independent nodes, although all system capabilities are accessible from a central unit anywhere and at any time via internet. We have divided the tasks and have one node for alpha control, another for delta control, one for the dome, one for the focus and the central unit to interface with a pc. The nodes for alpha, delta and the dome will be used by means of FPGA's in order to efficiently sample the encoders and the control algorithms, and to generate the output for the motors and the servo. The focus will have a microcontroller, and the system is easy to expand in the event of the inclusion of more nodes. After having studied several fieldbus systems, we have opted for the CAN bus, because of its reliability and broadcasting possibilities. In this way, all the important information will be on the bus, and every node will be able to access the information at any time. This document explains the new design made in the IAA for the new consoles of control whose basic characteristics are, the distributed control, the hardware simplify, the cable remove, the safety and maintenance improve and facilitating the observation improving the interface with the user, and finally to prepare the system for the remote observation.

Interpretation of snowcover from satellite imagery for use in water supply forecasts in the Sierra Nevada

NASA Technical Reports Server (NTRS)

Brown, A. J.; Hannaford, J. F.

1975-01-01

The California ASVT test area is composed of two study areas; one in Northern California covering the Upper Sacramento and Feather River Basins, and the other covering the Southern Sierra Basins of the San Joaquin, Kings, Kaweah, Tule, and Kern Rivers. Experiences of reducing snowcover from satellite imagery; the accuracy of present water supply forecast schemes; and the potential advantages of introducing snowcover into the forecast procedures are described.

Analysing the effects of the 2002 McNally fire on air quality in the San Joaquin Valley and southern Sierra Nevada, California

Treesearch

Ricardo Cisneros; Donald Schweizer; Sharon Zhong; Katharine Hammond; Miguel A. Perez; Qinghua Guo; Samuel Traina; Andrzej Bytnerowicz; Deborah H. Bennett

2012-01-01

Smoke from wildfires can expose individuals and populations to elevated levels of particulate matter (PM) and ozone (O3). Between 21 July and 26 August 2002, the McNally Fire burned over 150 000 acres (61 000 ha). The fire occurred in the Sequoia National Forest, in the southern Sierra Nevada of California. This study evaluated the effects of the McNally Fire on air...

Factors Underlying Ebola Virus Infection Among Health Workers, Kenema, Sierra Leone, 2014–2015

PubMed Central

Senga, Mikiko; Pringle, Kimberly; Ramsay, Andrew; Brett-Major, David M.; Fowler, Robert A.; French, Issa; Vandi, Mohamed; Sellu, Josephine; Pratt, Christian; Saidu, Josephine; Shindo, Nahoko; Bausch, Daniel G.

2016-01-01

Background. Ebola virus disease (EVD) in health workers (HWs) has been a major challenge during the 2014–2015 outbreak. We examined factors associated with Ebola virus exposure and mortality in HWs in Kenema District, Sierra Leone. Methods. We analyzed data from the Sierra Leone National Viral Hemorrhagic Fever Database, contact tracing records, Kenema Government Hospital (KGH) staff and Ebola Treatment Unit (ETU) rosters, and burial logs. Results. From May 2014 through January 2015, 600 cases of EVD originated in Kenema District, including 92 (15%) HWs, 66 (72%) of whom worked at KGH. Among KGH medical staff and international volunteers, 18 of 62 (29%) who worked in the ETU developed EVD, compared with 48 of 83 (58%) who worked elsewhere in the hospital. Thirteen percent of HWs with EVD reported contact with EVD patients, while 27% reported contact with other infected HWs. The number of HW EVD cases at KGH declined roughly 1 month after implementation of a new triage system at KGH and the opening of a second ETU within the district. The case fatality ratio for HWs and non-HWs with EVD was 69% and 74%, respectively. Conclusions. The cluster of HW EVD cases in Kenema District is one of the largest ever reported. Most HWs with EVD had potential virus exposure both inside and outside of hospitals. Prevention measures for HWs must address a spectrum of infection risks in both formal and informal care settings as well as in the community. PMID:27193749

Paediatric care in relation to the 2014–2015 Ebola outbreak and general reporting of deaths in Sierra Leone

PubMed Central

Denisiuk, O.; Shringarpure, K. K.; Wurie, B. S.; George, P.; Sesay, M. I.; Zachariah, R.

2017-01-01

Setting: All peripheral health units countrywide in Sierra Leone and one hospital in Port Loko. Objectives: Sierra Leone was severely affected by the 2014–2015 Ebola outbreak, whose impact on paediatric care and mortality reports merits assessment. We sought to compare the periods before, during and after the Ebola outbreak, the countrywide trend in morbidities in children aged < 5 years and exit outcomes in one district hospital (Port Loko). During the Ebola outbreak period, gaps in district death reporting within the routine Health Management Information System (HMIS) were compared with the Safe and Dignified Burials (SDB) database in Port Loko. Design: This was a retrospective records analysis. Results: The average number of monthly consultations during the Ebola outbreak period declined by 27% for malaria and acute respiratory infections and 38% for watery diarrhoea, and did not recover to the pre-Ebola levels. For measles, there was an 80% increase during Ebola, which multiplied by 6.5-fold post-Ebola. The number of unfavourable hospital exit outcomes was 52/397 (13%) during Ebola, which was higher than pre-Ebola (47/496, 9%, P = 0.04). Of 6565 deaths reported in the Port Loko SDB database, only 2219 (34%) appeared in the HMIS, a reporting deficit of 66%. Conclusion: The Ebola disease outbreak was associated with reduced utilisation of health services, and appears to have triggered a measles epidemic. Almost 70% of deaths were missed by the HMIS during the Ebola outbreak period. These findings could guide health system responses in future outbreaks. PMID:28744437

Early Paleozoic magmatic events in the eastern Klamath Mountains, northern California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wallin, E.T.; Mattinson, J.M.; Potter, A.W.

1988-02-01

New U-Pb zircon ages for nine samples of tonalite and pegmatitic trondhjemite from the Trinity ophiolite and associated melange reveal a complex history of magmatic activity extending back into the earliest Cambrian, much older than previously believed. Earlier investigations, based on limited data, recognized lower Paleozoic crustal elements in the eastern Klamath terrane (EKT) ranging in age from Middle Ordovician to Early to Middle Devonian. The new work in the Yreka-Callahan area of the EKT confirms the Ordovician (440-475 Ma) and younger ages, but reveals for the first time the presence of tonalitic rocks that crystallized during a narrow timemore » interval at about 565-570 Ma. The authors also recognize younger, Late Silurian magmatism at 412 Ma. In the context of available mapping, these ages indicate that the Trinity ophiolite is broadly polygenetic because parts of it yield crystallization ages that span approximately 150 m.y. Superjacent dismembered units of probable early Paleozoic age may be tectonostratigraphically equivalent to the Sierra City melange in the northern Sierra Nevada.« less

Calpionellid distribution and microfacies across the Jurassic/ Cretaceous boundary in western Cuba (Sierra de los Órganos)

NASA Astrophysics Data System (ADS)

López-Martínez, Rafael; Barragán, Ricardo; Reháková, Daniela; Cobiella-Reguera, Jorge Luis

2013-06-01

A detailed bed-by-bed sampled stratigraphic section of the Guasasa Formation in the Rancho San Vicente area of the "Sierra de los Órganos", western Cuba, provides well-supported evidence about facies and calpionellid distribution across the Jurassic/Cretaceous boundary. These new data allowed the definition of an updated and sound calpionellid biozonation scheme for the section. In this scheme, the drowning event of a carbonate platform displayed by the facies of the San Vicente Member, the lowermost unit of the section, is dated as Late Tithonian, Boneti Subzone. The Jurassic/Cretaceous boundary was recognized within the facies of the overlying El Americano Member on the basis of the acme of Calpionella alpina Lorenz. The boundary is placed nearly six meters above the contact between the San Vicente and the El Americano Members, in a facies linked to a sea-level drop. The recorded calpionellid bioevents should allow correlations of the Cuban biozonation scheme herein proposed, with other previously published schemes from distant areas of the Tethyan Domain.

Regional polyphase deformation of the Eastern Sierras Pampeanas (Argentina Andean foreland): strengths and weaknesses of paleostress inversion

NASA Astrophysics Data System (ADS)

Traforti, Anna; Zampieri, Dario; Massironi, Matteo; Viola, Giulio; Alvarado, Patricia; Di Toro, Giulio

2016-04-01

The Eastern Sierras Pampeanas of central Argentina are composed of a series of basement-cored ranges, located in the Andean foreland c. 600 km east of the Andean Cordillera. Although uplift of the ranges is partly attributed to the regional Neogene evolution (Ramos et al. 2002), many questions remain as to the timing and style of deformation. In fact, the Eastern Sierras Pampeanas show compelling evidence of a long lasting brittle history (spanning the Early Carboniferous to Present time), characterised by several deformation events reflecting different tectonic regimes. Each deformation phase resulted in further strain increments accommodated by reactivation of inherited structures and rheological anisotropies (Martino 2003). In the framework of such a polyphase brittle tectonic evolution affecting highly anisotropic basement rocks, the application of paleostress inversion methods, though powerful, suffers from some shortcomings, such as the likely heterogeneous character of fault slip datasets and the possible reactivation of even highly misoriented structures, and thus requires careful analysis. The challenge is to gather sufficient fault-slip data, to develop a proper understanding of the regional evolution. This is done by the identification of internally consistent fault and fracture subsets (associated to distinct stress states on the basis of their geometric and kinematic compatibility) in order to generate a chronologically-constrained evolutionary conceptual model. Based on large fault-slip datasets collected in the Sierras de Cordoba (Eastern Sierras Pampeanas), reduced stress tensors have been generated and interpreted as part of an evolutionary model by considering the obtained results against: (i) existing K-Ar illite ages of fault gouges in the study area (Bense et al. 2013), (ii) the nature and orientation of pre-existing anisotropies and (iii) the present-day stress field due to the convergence of the Nazca and South America plates (main shortening oriented WSW-ENE). Although remarkable differences in reactivation mechanisms have been observed for the various studied lithological domains (schist, gneiss and granitic rocks), the brittle regional polyphase deformation of the Eastern Sierras Pampeanas appears to be dominated by two extensional episodes (σ3 oriented NE/ENE and WNW, respectively), which can be associated with Middle-Late Permian to Early Cretaceous tectonism, followed by a compressional paleostress (σ1 oriented ENE), which is compatible with the present day Andean convergence. Paleostress inversion techniques, despite all uncertainties involved, represent a robust approach to disentangle complex polyphase deformation histories both in term of reactivation mechanisms and strain partitioning. References: Bense, F. A., Wemmer, K., Löbens, S., & Siegesmund, S. (2013). Fault gouge analyses: K-Ar illite dating, clay mineralogy and tectonic significance-a study from the Sierras Pampeanas, Argentina. International Journal of Earth Sciences, 103, 189-218. Martino, R. D. (2003). Las fajas de deformación dúctil de las Sierras Pampeanas de Córdoba : Una reseña general. Revista de La Asociación Geológica Argentina, 58(4), 549-571. Ramos, V. A., Cristallini, E. O., & Perez, D. J. (2002). The Pampean flat-slab of the Central Andes. Journal of South American Earth Sciences, 15, 59-78.

Lassa Fever in Post-Conflict Sierra Leone

PubMed Central

Hartnett, Jessica N.; Levy, Danielle C.; Yenni, Rachael E.; Moses, Lina M.; Fullah, Mohammed; Momoh, Mambo; Fonnie, Mbalu; Fonnie, Richard; Kanneh, Lansana; Koroma, Veronica J.; Kargbo, Kandeh; Ottomassathien, Darin; Muncy, Ivana J.; Jones, Abigail B.; Illick, Megan M.; Kulakosky, Peter C.; Haislip, Allyson M.; Bishop, Christopher M.; Elliot, Deborah H.; Brown, Bethany L.; Zhu, Hu; Hastie, Kathryn M.; Andersen, Kristian G.; Gire, Stephen K.; Tabrizi, Shervin; Tariyal, Ridhi; Stremlau, Mathew; Matschiner, Alex; Sampey, Darryl B.; Spence, Jennifer S.; Cross, Robert W.; Geisbert, Joan B.; Folarin, Onikepe A.; Happi, Christian T.; Pitts, Kelly R.; Geske, F. Jon; Geisbert, Thomas W.; Saphire, Erica Ollmann; Robinson, James E.; Wilson, Russell B.; Sabeti, Pardis C.; Henderson, Lee A.; Khan, S. Humarr; Bausch, Daniel G.; Branco, Luis M.; Garry, Robert F.

2014-01-01

Background Lassa fever (LF), an often-fatal hemorrhagic disease caused by Lassa virus (LASV), is a major public health threat in West Africa. When the violent civil conflict in Sierra Leone (1991 to 2002) ended, an international consortium assisted in restoration of the LF program at Kenema Government Hospital (KGH) in an area with the world's highest incidence of the disease. Methodology/Principal Findings Clinical and laboratory records of patients presenting to the KGH Lassa Ward in the post-conflict period were organized electronically. Recombinant antigen-based LF immunoassays were used to assess LASV antigenemia and LASV-specific antibodies in patients who met criteria for suspected LF. KGH has been reestablished as a center for LF treatment and research, with over 500 suspected cases now presenting yearly. Higher case fatality rates (CFRs) in LF patients were observed compared to studies conducted prior to the civil conflict. Different criteria for defining LF stages and differences in sensitivity of assays likely account for these differences. The highest incidence of LF in Sierra Leone was observed during the dry season. LF cases were observed in ten of Sierra Leone's thirteen districts, with numerous cases from outside the traditional endemic zone. Deaths in patients presenting with LASV antigenemia were skewed towards individuals less than 29 years of age. Women self-reporting as pregnant were significantly overrepresented among LASV antigenemic patients. The CFR of ribavirin-treated patients presenting early in acute infection was lower than in untreated subjects. Conclusions/Significance Lassa fever remains a major public health threat in Sierra Leone. Outreach activities should expand because LF may be more widespread in Sierra Leone than previously recognized. Enhanced case finding to ensure rapid diagnosis and treatment is imperative to reduce mortality. Even with ribavirin treatment, there was a high rate of fatalities underscoring the need to develop more effective and/or supplemental treatments for LF. PMID:24651047

Acting Administrator Lightfoot Visits Sierra Nevada Corporation

NASA Image and Video Library

2017-04-06

Associate administrator of NASA's Office of International and Interagency Relations Al Condes, left, acting NASA Deputy Administrator Lesa Roe, second from left, and acting NASA Administrator Robert Lightfoot, center, listen as Jude Vrazel, a senior systems engineer at Sierra Nevada Corporation, right, discusses the Vehicle Avionics Integration Lab (VAIL), Thursday, April 6, 2017 during a visit to Sierra Nevada Corporation in Louisville, Colo. Sierra Nevada Corporation, with their Dream Chaser Cargo System, was one of three companies to be awarded Commercial Resupply Services (CRS-2) contracts designed to obtain cargo delivery services to the space station, disposal of unneeded cargo, and the return of research samples and other cargo from the station back to NASA. Photo Credit: (NASA/Joel Kowsky)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sierra Thermal /Fluid Team

The SIERRA Low Mach Module: Fuego along with the SIERRA Participating Media Radiation Module: Syrinx, henceforth referred to as Fuego and Syrinx, respectively, are the key elements of the ASCI fire environment simulation project. The fire environment simulation project is directed at characterizing both open large-scale pool fires and building enclosure fires. Fuego represents the turbulent, buoyantly-driven incompressible flow, heat transfer, mass transfer, combustion, soot, and absorption coefficient model portion of the simulation software. Syrinx represents the participating-media thermal radiation mechanics. This project is an integral part of the SIERRA multi-mechanics software development project. Fuego depends heavily upon the coremore » architecture developments provided by SIERRA for massively parallel computing, solution adaptivity, and mechanics coupling on unstructured grids.« less

Isotopic variation in the Tuolumne Intrusive Suite, central Sierra Nevada, California

USGS Publications Warehouse

Kistler, R.W.; Chappell, B.W.; Peck, D.L.; Bateman, P.C.

1986-01-01

Granitoid rocks of the compositionally zoned Late Cretaceous Toulumne Intrusive Suite in the central Sierra Nevada, California, have initial87Sr/86Sr values (Sri) and143Nd/144Nd values (Ndi) that vary from 0.7057 to 0.7067 and from 0.51239 to 0.51211 respectively. The observed variation of both Sri and Ndi and of chemical composition in rocks of the suite cannot be due to crystal fractionation of magma solely under closed system conditons. The largest variation in chemistry, Ndi, and Sri is present in the outer-most equigranular units of the Tuolumne Intrusive Suite. Sri varies positively with SiO2, Na2O, K2O, and Rb concentrations, and negatively with Ndi, Al2O3, Fe2O3, MgO, FeO, CaO, MnO, P2O5, TiO2, and Sr concentrations. This covariation of Sri, Ndi and chemistry can be modeled by a process of simple mixing of basaltic and granitic magmas having weight percent SiO2 of 48.0 and 73.3 respectively. Isotopic characteristic of the mafic magma are Sri=0.7047, Ndi=0.51269 and ??18O=6.0, and of the felsic magma are Sri=0.7068, Ndi=0.51212 and ??18O=8.9. The rocks sampled contain from 50 to 80% of the felsic component. An aplite in the outer equigranular unit of the Tuolumne Intrusive Suite apparently was derived by fractional crystallization of plagioclase and hornblende from magma with granudiorite composition that was a product of mixing of the magmas described above. Siliceous magmas derived from the lower crust, having a maximum of 15 percent mantle-derived mafic component, are represented by the inner prophyritic units of the Tuolumne Intrusive Suite. ?? 1986 Springer-Verlag.

Increases in flood magnitudes in California under warming climates

USGS Publications Warehouse

Das, Tapash; Maurer, Edwin P.; Pierce, David W.; Dettinger, Michael D.; Cayah, Daniel R.

2013-01-01

Downscaled and hydrologically modeled projections from an ensemble of 16 Global Climate Models suggest that flooding may become more intense on the western slopes of the Sierra Nevada mountains, the primary source for California’s managed water system. By the end of the 21st century, all 16 climate projections for the high greenhouse-gas emission SRES A2 scenario yield larger floods with return periods ranging 2–50 years for both the Northern Sierra Nevada and Southern Sierra Nevada, regardless of the direction of change in mean precipitation. By end of century, discharges from the Northern Sierra Nevada with 50-year return periods increase by 30–90% depending on climate model, compared to historical values. Corresponding flood flows from the Southern Sierra increase by 50–100%. The increases in simulated 50 year flood flows are larger (at 95% confidence level) than would be expected due to natural variability by as early as 2035 for the SRES A2 scenario.

Precipitation Structure in the Sierra Nevada of California During Winter

NASA Technical Reports Server (NTRS)

Pandey, Ganesh R.; Cayan, Daniel R.; Georgakakos, Kostantine P.

1998-01-01

The influences of upper air characteristics along the coast of California upon the winter time precipitation in the Sierra Nevada region were investigated. Most precipitation episodes in the Sierra are associated with moist southwesterly winds and also tend to occur when the 700-mb temperature is close to -2 C. This favored wind direction and temperature signifies the equal importance of moisture transport and orographic lifting for maximum precipitation frequency. Making use of this observation, simple linear models were formulated to quantify the precipitation totals observed at different sites as a function of moisture transport. The skill of the model is least for daily precipitation and increases with time scale of aggregation. In terms of incremental gain, the skill of the model is optimal for an aggregation period of 5-7 days, which is also the duration of the most frequent precipitation events in the Sierra. This indicates that upper air moisture transport at can be used to make reasonable estimates of the precipitation totals for most frequent events in the Sierra region.

Phylogeography of the California mountain kingsnake, Lampropeltis zonata (Colubridae).

PubMed

Rodríguez-Robles, J A; Denardo, D F; Staub, R E

1999-11-01

The phylogeography of the California mountain kingsnake, Lampropeltis zonata, was studied using mitochondrial DNA sequences from specimens belonging to the seven recognized subspecies and collected throughout the range of the species. Maximum parsimony and maximum likelihood methods identified a basal split within L. zonata that corresponds to southern and northern segments of its distribution. The southern clade is composed of populations from southern California (USA) and northern Baja California, Mexico. The northern clade is divided into two subclades, a 'coastal' subclade, consisting of populations from the central coast of California and the southern Sierra Nevada Mountains of eastern California, and a 'northeastern' subclade, mainly comprised of populations north of the San Francisco Bay and from the majority of the Sierra Nevada. We suggest that past inland seaways in southwestern California and the embayment of central California constituted barriers to gene flow that resulted in the two deepest divergences within L. zonata. Throughout its evolutionary history, the northern clade apparently has undergone instances of range contraction, isolation, differentiation, and then expansion and secondary contact. Examination of colour pattern variation in 321 living and preserved specimens indicated that the two main colour pattern characters used to define the subspecies of L. zonata are so variable that they cannot be reliably used to differentiate taxonomic units within this complex, which calls into question the recognition of seven geographical races of this snake.

Fens as whole-ecosystem gauges of groundwater recharge under climate change

USGS Publications Warehouse

Drexler, Judith Z.; Knifong, Donna L.; JayLee Tuil,; Flint, Lorraine E.; Flint, Alan L.

2013-01-01

Currently, little is known about the impact of climate change on groundwater recharge in the Sierra Nevada and southern Cascade Range of California or other mountainous regions of the world. The purpose of this study was to determine whether small alpine peat lands called fens can be used as whole-ecosystem gauges of groundwater recharge through time. Fens are sustained by groundwater discharge and are highly sensitive to changes in groundwater flow due to hydrologic disturbance including climate change. Seven fens in the Sierra Nevada and southern Cascade Range were studied over a 50-80 year period using historic aerial photography. In each aerial photograph, fen areas were identified as open lawn and partially treed areas that exhibited (1) dark brownish-green coloring or various shades of gray and black in black and white imagery and (2) mottling of colors and clustering of vegetation, which signified a distinct moss canopy with overlying clumped sedge vegetation. In addition to the aerial photography study, a climate analysis for the study sites was carried out using both measured data (U.S. Department of Agriculture Natural Resources Conservation Service SNOwpack TELemetry system) and modeled data (a downscaled version of the Parameter-elevation Regressions on Independent Slopes Model) for the period from 1951 to 2010. Over the study period, the five fens in the Sierra Nevada were found to be decreasing between 10% and 16% in delineated area. The climate analysis revealed significant increases through time in annual mean minimum temperature (Tmin) between 1951-1980 and 1981-2010. In addition, April 1 snow water equivalent and snowpack longevity also decreased between 1951-1980 and 1981-2010. For the fens in the Cascade Range, there were no discernible changes in delineated area. At these sites, increases in Tmin occurred only within the past 20-25 years and decreases in snowpack longevity were more subtle. A conceptual model is presented, which illustrates that basic differences in hydrogeology of the Sierra Nevada vs. the Cascade Range may control the threshold at which changes in delineated fen areas are discernible. Overall, the results from this study show that fens in the Sierra Nevada have strong potential as whole ecosystem gauges for determining long-term changes in groundwater recharge under climate change. Due to either more moderate climate change and/or hydrogeological differences, fens in the southern Cascade Range currently do not appear to have the same utility. A greater sample size of fens in the Sierra Nevada is needed to confirm the general applicability of this method. In addition, future work needs to focus on integrating fen monitoring with geochemical and/or isotopic process-level studies in order to quantify changes in groundwater recharge identified using this new approach.

NASA Deputy Administrator Tours Sierra Nevada Space Systems

NASA Image and Video Library

2011-02-05

NASA Deputy Administrator Lori Garver speaks at Sierra Nevada Space Systems, on Saturday, Feb. 5, 2011, in Louisville, Colo. Sierra Nevada's Dream Chaser spacecraft is under development with support from NASA's Commercial Crew Development Program to provide crew transportation to and from low Earth orbit. NASA is helping private companies develop innovative technologies to ensure that the U.S. remains competitive in future space endeavors. Photo Credit: (NASA/Bill Ingalls)

Guide to Using Sierra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaw, Ryan Phillip; Agelastos, Anthony Michael; Miller, Joel D.

2015-03-01

Sierra is an engineering mechanics simulation code suite supporting the Nation's Nuclear Weapons mission as well as other customers. It has explicit ties to Sandia National Labs' workfow, including geometry and meshing, design and optimization, and visualization. Dis- tinguishing strengths include "application aware" development, scalability, SQA and V&V, multiple scales, and multi-physics coupling. This document is intended to help new and existing users of Sierra as a user manual and troubleshooting guide.

Sierra Structural Dynamics User's Notes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reese, Garth M.

2015-10-19

Sierra/SD provides a massively parallel implementation of structural dynamics finite element analysis, required for high fidelity, validated models used in modal, vibration, static and shock analysis of weapons systems. This document provides a users guide to the input for Sierra/SD. Details of input specifications for the different solution types, output options, element types and parameters are included. The appendices contain detailed examples, and instructions for running the software on parallel platforms.

Guide to Using Sierra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaw, Ryan Phillip; Agelastos, Anthony Michael; Miller, Joel D.

2017-04-01

Sierra is an engineering mechanics simulation code suite supporting the Nation's Nuclear Weapons mission as well as other customers. It has explicit ties to Sandia National Labs' workfow, including geometry and meshing, design and optimization, and visualization. Dis- tinguishing strengths include "application aware" development, scalability, SQA and V&V, multiple scales, and multi-physics coupling. This document is intended to help new and existing users of Sierra as a user manual and troubleshooting guide.

Sierra/SD User's Notes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Munday, Lynn Brendon; Day, David M.; Bunting, Gregory

Sierra/SD provides a massively parallel implementation of structural dynamics finite element analysis, required for high fidelity, validated models used in modal, vibration, static and shock analysis of weapons systems. This document provides a users guide to the input for Sierra/SD. Details of input specifications for the different solution types, output options, element types and parameters are included. The appendices contain detailed examples, and instructions for running the software on parallel platforms.

Survivors' perceptions of public health messages during an Ebola crisis in Liberia and Sierra Leone: An exploratory study.

PubMed

Schwerdtle, Patricia; De Clerck, Veronique; Plummer, Virginia

2017-12-01

The outbreak of Ebola virus disease in Guinea, Liberia, and Sierra Leone was the largest epidemic of Ebola ever recorded. The healthcare workforce was diminished and exhausted as the region emerged from civil war. Few qualitative, descriptive studies have been conducted to date that concentrate on the voices of Ebola survivors and their perceptions of health messages. In this study, we employed an interpretive, qualitative design to explore participant experiences. Twenty five survivors who had recovered from Ebola were recruited from three villages in Liberia and Sierra Leone in August 2015. Data were collected using semistructured interviews. Data analysis revealed four themes: (i) degrees of mistrust; (ii) messages conflicting with life and culture; (iii) seeing is believing; and (iv) recovery inspires hope. The findings were explored in the context of the relevant literature. The themes highlight the need to develop culturally-appropriate messages, underpinned by a sound understanding of the community and a willingness to work with the culture and trusted leaders. © 2017 John Wiley & Sons Australia, Ltd.

Dust and biological aerosols from the Sahara and Asia influence precipitation in the western U.S.

PubMed

Creamean, Jessie M; Suski, Kaitlyn J; Rosenfeld, Daniel; Cazorla, Alberto; DeMott, Paul J; Sullivan, Ryan C; White, Allen B; Ralph, F Martin; Minnis, Patrick; Comstock, Jennifer M; Tomlinson, Jason M; Prather, Kimberly A

2013-03-29

Winter storms in California's Sierra Nevada increase seasonal snowpack and provide critical water resources and hydropower for the state. Thus, the mechanisms influencing precipitation in this region have been the subject of research for decades. Previous studies suggest Asian dust enhances cloud ice and precipitation, whereas few studies consider biological aerosols as an important global source of ice nuclei (IN). Here, we show that dust and biological aerosols transported from as far as the Sahara were present in glaciated high-altitude clouds coincident with elevated IN concentrations and ice-induced precipitation. This study presents the first direct cloud and precipitation measurements showing that Saharan and Asian dust and biological aerosols probably serve as IN and play an important role in orographic precipitation processes over the western United States.

The Met Needs for Pediatric Surgical Conditions in Sierra Leone: Estimating the Gap.

PubMed

Burgos, Carmen Mesas; Bolkan, Håkon Angell; Bash-Taqi, Donald; Hagander, Lars; Von Screeb, Johan

2018-03-01

In low- and middle-income countries, there is a gap between the need for surgery and its equitable provision, and a lack of proxy indicators to estimate this gap. Sierra Leone is a West African country with close to three million children. It is unknown to what extent the surgical needs of these children are met. To describe a nationwide provision of pediatric surgical procedures and to assess pediatric hernia repair as a proxy indicator for the shortage of surgical care in the pediatric population in Sierra Leone. We analyzed results from a nationwide facility survey in Sierra Leone that collected data on surgical procedures from operation and anesthesia logbooks in all facilities performing surgery. We included data on all patients under the age of 16 years undergoing surgery. Primary outcomes were rate and volume of surgical procedures. We calculated the expected number of inguinal hernia in children and estimated the unmet need for hernia repair. In 2012, a total of 2381 pediatric surgical procedures were performed in Sierra Leone. The rate of pediatric surgical procedures was 84 per 100,000 children 0-15 years of age. The most common pediatric surgical procedure was hernia repair (18%), corresponding to a rate of 16 per 100,000 children 0-15 years of age. The estimated unmet need for inguinal hernia repair was 88%. The rate of pediatric surgery in Sierra Leone was very low, and inguinal hernia was the single most common procedure noted among children in Sierra Leone.

Incorporating Cold-Air Pooling into Downscaled Climate Models Increases Potential Refugia for Snow-Dependent Species within the Sierra Nevada Ecoregion, CA

PubMed Central

Curtis, Jennifer A.; Flint, Lorraine E.; Flint, Alan L.; Lundquist, Jessica D.; Hudgens, Brian; Boydston, Erin E.; Young, Julie K.

2014-01-01

We present a unique water-balance approach for modeling snowpack under historic, current and future climates throughout the Sierra Nevada Ecoregion. Our methodology uses a finer scale (270 m) than previous regional studies and incorporates cold-air pooling, an atmospheric process that sustains cooler temperatures in topographic depressions thereby mitigating snowmelt. Our results are intended to support management and conservation of snow-dependent species, which requires characterization of suitable habitat under current and future climates. We use the wolverine (Gulo gulo) as an example species and investigate potential habitat based on the depth and extent of spring snowpack within four National Park units with proposed wolverine reintroduction programs. Our estimates of change in spring snowpack conditions under current and future climates are consistent with recent studies that generally predict declining snowpack. However, model development at a finer scale and incorporation of cold-air pooling increased the persistence of April 1st snowpack. More specifically, incorporation of cold-air pooling into future climate projections increased April 1st snowpack by 6.5% when spatially averaged over the study region and the trajectory of declining April 1st snowpack reverses at mid-elevations where snow pack losses are mitigated by topographic shading and cold-air pooling. Under future climates with sustained or increased precipitation, our results indicate a high likelihood for the persistence of late spring snowpack at elevations above approximately 2,800 m and identify potential climate refugia sites for snow-dependent species at mid-elevations, where significant topographic shading and cold-air pooling potential exist. PMID:25188379

Incorporating cold-air pooling into downscaled climate models increases potential refugia for snow-dependent species within the Sierra Nevada Ecoregion, CA

USGS Publications Warehouse

Curtis, Jennifer A.; Flint, Lorraine E.; Flint, Alan L.; Lundquist, Jessica D.; Hudgens, Brian; Boydston, Erin E.; Young, Julie K.

2014-01-01

We present a unique water-balance approach for modeling snowpack under historic, current and future climates throughout the Sierra Nevada Ecoregion. Our methodology uses a finer scale (270 m) than previous regional studies and incorporates cold-air pooling, an atmospheric process that sustains cooler temperatures in topographic depressions thereby mitigating snowmelt. Our results are intended to support management and conservation of snow-dependent species, which requires characterization of suitable habitat under current and future climates. We use the wolverine (Gulo gulo) as an example species and investigate potential habitat based on the depth and extent of spring snowpack within four National Park units with proposed wolverine reintroduction programs. Our estimates of change in spring snowpack conditions under current and future climates are consistent with recent studies that generally predict declining snowpack. However, model development at a finer scale and incorporation of cold-air pooling increased the persistence of April 1st snowpack. More specifically, incorporation of cold-air pooling into future climate projections increased April 1st snowpack by 6.5% when spatially averaged over the study region and the trajectory of declining April 1st snowpack reverses at mid-elevations where snow pack losses are mitigated by topographic shading and cold-air pooling. Under future climates with sustained or increased precipitation, our results indicate a high likelihood for the persistence of late spring snowpack at elevations above approximately 2,800 m and identify potential climate refugia sites for snow-dependent species at mid-elevations, where significant topographic shading and cold-air pooling potential exist.

Wetland occupancy of pond-breeding amphibians in Yosemite National Park, USA

USGS Publications Warehouse

Fellers, Gary M.; Kleeman, Patrick M.; Miller, David A.W.

2015-01-01

We estimated wetland occupancy and population trends for three species of pond-breeding anurans in Yosemite National Park from 2007-2011. We used a double survey technique in which two observers independently surveyed each site on the same day. Double surveys allowed us to calculate detectability for the three most common anurans within the park: Rana sierrae, Anaxyrus canorus, and Pseudacris regilla. Annual estimates of detectability were generally high; mean detectability ranged from 73.7% + 0.6 (SE) for any life history stage of A. canorus to 86.7% + 0.7 for sites with P. regilla reproduction (eggs or larvae present). Detectability was most variable for Anaxyrus canorus, which ranged from 45.9% to 99.7%. The probability of occupancy for R. sierrae was highest in larger, low-elevation wetlands that lacked fish. Anaxyrus canorus were more common in shallow high-elevation ponds; their occurrence was minimally impacted by the presence of fish. Finally, occurrence of P. regilla was largely unrelated to wetland size and elevation, but like R. sierrae, they were less likely to occupy sites with fi sh. Occupancy showed no trend over the five years of our study for R. sierrae or A. canorus when considering either sites with any life stage or only sites with reproduction. However, P. regilla showed a modest downward trend for sites with any life stage and sites with reproduction. Our results for R. sierrae run counter to expectations given recent concern about the decline of this species, while our findings for P. regilla raise concerns for this widespread and generally common species.

Rapid assessment of knowledge, attitudes, practices, and risk perception related to the prevention and control of Ebola virus disease in three communities of Sierra Leone.

PubMed

Jiang, Hai; Shi, Guo-Qing; Tu, Wen-Xiao; Zheng, Can-Jun; Lai, Xue-Hui; Li, Xin-Xu; Wei, Qiang; Li, Mei; Deng, Li-Quan; Huo, Xiang; Chen, Ming-Quan; Xu, Feng; Ye, Long-Jie; Bai, Xi-Chen; Chen, Tong-Nian; Yin, Shao-Hua; Samba, Thomas T; Liang, Xiao-Feng

2016-06-06

The recent outbreak of the Ebola virus disease (EVD) in Sierra Leone has been characterized by the World Health Organization as one of the most challenging EVD outbreaks to date. The first confirmed case in Sierra Leone was a young woman who was admitted to a government hospital in Kenema following a miscarriage on 24 May 2014. On 5 January 2015, intensified training for an EVD response project was initiated at the medical university of Sierra Leone in Jui. To understand the knowledge, attitudes, practices, and perceived risk of EVD among the public, especially after this training, a rapid assessment was conducted from 10 to 16 March 2015. Interviews were conducted with 466 participants based on questionnaires that were distributed from 10 to 16 March 2015 by cluster sampling in three adjacent communities, namely Jui, Grafton, and Kossoh Town, in the Western Area Rural District of Sierra Leone. It was found that knowledge about EVD was comprehensive and high. Positive attitude towards prevention was found to be satisfactory. Nearly all participants knew the reporting phone number 117 and had reported some change in behavior since learning about Ebola. More than half (62 %) of the participants had a history of travelling to urban areas, which increases the risk of infection. The multivariable logistic regression analysis showed that community and occupation were variables associated with perceived risk of EVD. Our study showed that community level social mobilization and community engagement were an effective strategy in the special context.

Hydrologic Response and Watershed Sensitivity to Climate Warming in California's Sierra Nevada

PubMed Central

Null, Sarah E.; Viers, Joshua H.; Mount, Jeffrey F.

2010-01-01

This study focuses on the differential hydrologic response of individual watersheds to climate warming within the Sierra Nevada mountain region of California. We describe climate warming models for 15 west-slope Sierra Nevada watersheds in California under unimpaired conditions using WEAP21, a weekly one-dimensional rainfall-runoff model. Incremental climate warming alternatives increase air temperature uniformly by 2°, 4°, and 6°C, but leave other climatic variables unchanged from observed values. Results are analyzed for changes in mean annual flow, peak runoff timing, and duration of low flow conditions to highlight which watersheds are most resilient to climate warming within a region, and how individual watersheds may be affected by changes to runoff quantity and timing. Results are compared with current water resources development and ecosystem services in each watershed to gain insight into how regional climate warming may affect water supply, hydropower generation, and montane ecosystems. Overall, watersheds in the northern Sierra Nevada are most vulnerable to decreased mean annual flow, southern-central watersheds are most susceptible to runoff timing changes, and the central portion of the range is most affected by longer periods with low flow conditions. Modeling results suggest the American and Mokelumne Rivers are most vulnerable to all three metrics, and the Kern River is the most resilient, in part from the high elevations of the watershed. Our research seeks to bridge information gaps between climate change modeling and regional management planning, helping to incorporate climate change into the development of regional adaptation strategies for Sierra Nevada watersheds. PMID:20368984

Mexican native trouts: A review of their history and current systematic and conservation status

USGS Publications Warehouse

Hendrickson, D.A.; Perez, H.E.; Findley, L.T.; Forbes, W.; Tomelleri, J.R.; Mayden, Richard L.; Nielsen, J.L.; Jensen, B.; Campos, G.R.; Romero, A.V.; van der Heiden, A.; Camarena, F.; Garcia de Leon, F.J.

2002-01-01

While biologists have been aware of the existence of native Mexican trouts for over a century, they have received little study. The few early studies that did much more than mention their existence began in the 1930s and continued into the early 1960s, focusing primarily on distributional surveys and taxonomic analyses. Starting in the 1980s the Baja California rainbow trout became the subject of more detailed studies, but very little remains known of mainland trouts of the Sierra Madre Occidental. We review earlier studies and report on our own collections and observations made between 1975 and 2000. We present newly discovered historical evidence that leads us to conclude that a "lost" cutthroat trout, a lineage not previously known from Mexico, was collected more than a century ago from headwaters of the Ri??o Conchos (a major tributary of the Rio Grande (= Ri??o Bravo)), a basin not previously considered to harbor a native trout. We review the last century of regional natural resource management and discuss our own observations of trout habitats. Impacts of logging, road building and overgrazing are widespread and expanding. Many streams suffer from heavy erosion, siltation and contamination, and though long-term hydrologic data are generally not available, there is evidence of decreased discharge in many streams. These problems appear related to region-wide land management practices as well as recent regional drought. Trout culture operations using exotic rainbow trout have rapidly proliferated throughout the region, threatening genetic introgression and/or competition with native forms and predation on them. Knowledge of distribution, abundance, relationships and taxonomy, not to mention ecology and population biology, of native trouts of the Sierra Madre Occidental remains inadequate. Vast areas of most mainland drainages are still unexplored by fish collectors, and even rudimentary information regarding basic biology, ecology and population structure of stocks remains lacking. Concentrated exploration, research and management of this long overlooked and undervalued resource are all urgently needed. The history of natural resources exploitation that placed so many native trouts of the western United States on threatened and endangered species lists is repeating itself in the Sierra Madre Occidental. Without concentrated action and development of region-wide socio-economic solutions for current, largely non-sustainable resource management practices, native Mexican trout gene pools will soon be in grave danger of extinction.

Expanded science and management utllity of SWE and albedo data from the NASA/JPL Airborne Snow Observatory

NASA Astrophysics Data System (ADS)

Painter, T. H.; Deems, J. S.; Marks, D. G.; Hedrick, A. R.; Bormann, K.; Skiles, S. M.; Boardman, J. W.; Graham, C. B.; McGurk, B. J.; Gehrke, F.; Berisford, D. F.; Ferraz, A.; Saatchi, S.; Schimel, D.

2016-12-01

The NASA Airborne Snow Observatory (ASO), an imaging spectrometer and imaging LiDAR system, to quantify snow water equivalent and snow albedo, provide unprecedented knowledge of snow properties, and provide complete, robust inputs to snowmelt runoff models, water management models, and systems of the future. This talk presents results from the fourth year of the ASO program, 2016, and the now four years of data record in the Western United States. Following on the heels of the most intense, sustained drought in California history, 2016 held promise of a large snowfall year due to an intense El Nino anomaly. Ultimately, the year had approximately 85% of average peak SWE. In the Sierra Nevada, ASO measured 10x greater SWE than near peak in the dramatic 2015 drought year, and twice that of the more moderate drought year of 2013. Water managers in the Sierra were using these data regularly and extending the dynamic range of newly established relationships between accumulated runoff (circa April through July runoff) and ASO total basin SWE acquisitions. ASO also participated in the NASA OLYMPEX project by flying the entire snow-covered reghions of the Olympic Peninsula for distributed SWE. These data are now being used to validate snowfall estimates from modeling and accumulation patterns as inferred from the NASA Global Precipitation Measurement mission (GPM). The ASO snow program expanded to acquire data in the McKenzie and Deschutes Rivers of Oregon in participation with university and state/federal agencies; Sagehen and Lee Vining basins in the Sierra Nevada, California; the Reynolds Creek Experimental Watershed in Idaho; and the East River, in the Colorado River Basin. These regions extend the existing program flying the Tuolumne, Merced, Lakes, Rush Creek, and Middle+South Forks of Kings River Basins in the California Sierra Nevada and the Upper Rio Grande, Conejos, and Uncompahgre Basins in the Colorado Rocky Mountains.The ASO SWE and albedo data are now being used to constrain various hydrologic models for water cycle science of varying complexity and expanding empirical and physically-based water management models.

Estimating the future number of cases in the Ebola epidemic--Liberia and Sierra Leone, 2014-2015.

PubMed

Meltzer, Martin I; Atkins, Charisma Y; Santibanez, Scott; Knust, Barbara; Petersen, Brett W; Ervin, Elizabeth D; Nichol, Stuart T; Damon, Inger K; Washington, Michael L

2014-09-26

The first cases of the current West African epidemic of Ebola virus disease (hereafter referred to as Ebola) were reported on March 22, 2014, with a report of 49 cases in Guinea. By August 31, 2014, a total of 3,685 probable, confirmed, and suspected cases in West Africa had been reported. To aid in planning for additional disease-control efforts, CDC constructed a modeling tool called EbolaResponse to provide estimates of the potential number of future cases. If trends continue without scale-up of effective interventions, by September 30, 2014, Sierra Leone and Liberia will have a total of approximately 8,000 Ebola cases. A potential underreporting correction factor of 2.5 also was calculated. Using this correction factor, the model estimates that approximately 21,000 total cases will have occurred in Liberia and Sierra Leone by September 30, 2014. Reported cases in Liberia are doubling every 15-20 days, and those in Sierra Leone are doubling every 30-40 days. The EbolaResponse modeling tool also was used to estimate how control and prevention interventions can slow and eventually stop the epidemic. In a hypothetical scenario, the epidemic begins to decrease and eventually end if approximately 70% of persons with Ebola are in medical care facilities or Ebola treatment units (ETUs) or, when these settings are at capacity, in a non-ETU setting such that there is a reduced risk for disease transmission (including safe burial when needed). In another hypothetical scenario, every 30-day delay in increasing the percentage of patients in ETUs to 70% was associated with an approximate tripling in the number of daily cases that occur at the peak of the epidemic (however, the epidemic still eventually ends). Officials have developed a plan to rapidly increase ETU capacities and also are developing innovative methods that can be quickly scaled up to isolate patients in non-ETU settings in a way that can help disrupt Ebola transmission in communities. The U.S. government and international organizations recently announced commitments to support these measures. As these measures are rapidly implemented and sustained, the higher projections presented in this report become very unlikely.

SIERRA ANCHA WILDERNESS, ARIZONA.

USGS Publications Warehouse

Wrucke, Chester T.; Light, Thomas D.

1984-01-01

Mineral surveys show that the Sierra Ancha Wilderness in Arizona has demonstrated resources of uranium, asbestos, and iron; probable and substantiated resource potential for uranium, asbestos, and iron; and a probable resource potential for fluorspar. Uranium resources occur in vein and strata-bound deposits in siltstone that underlies much of the wilderness. Deposits of long-staple chrysotile asbestos are likely in parts of the wilderness adjacent to known areas of asbestos production. Magnetite deposits in the wilderness form a small iron resource. No fossil fuel resources were identified in this study.

Two new species of Zospeum Bourguignat, 1856 from the Basque-Cantabrian Mountains, Northern Spain (Eupulmonata, Ellobioidea, Carychiidae)

PubMed Central

Jochum, Adrienne; de Winter, Anton J.; Weigand, Alexander M.; Gómez, Benjamín; Prieto, Carlos

2015-01-01

Abstract Two new species of the genus Zospeum Bourguignat, 1856 are described from caves in the Sierra de Aitzgorri (Gipuzkoa) and the Sierra Salvada (Burgos) in Northern Spain. The taxa Zospeum vasconicum sp. n. and Zospeum zaldivarae sp. n. have recently, without a formal name, been included in a molecular study of worldwide members of the Carychiidae. In the present paper, the shell morphology and variation of these species is described and illustrated. PMID:25755625

Mono Lake, California as seen from STS-59

NASA Image and Video Library

1994-04-14

STS059-154-160 (9-20 April 1994) --- Orient with Mono Lake, California at the lower right; then the view is westward across the Sierra Nevada into the San Joaquin River drainage. A tiny network of ski trails can be seen on the Mono Lake side of the Sierras, on a line between Mono Lake and the snow-free San Joaquin headwaters. The ski trails mark Mammoth Mountain, where SRL investigators are studying microwave measurements of the water content of snowpacks. Linhof camera.

Evaluating the use of cell phone messaging for community Ebola syndromic surveillance in high risked settings in Southern Sierra Leone.

PubMed

Jia, Kangbai; Mohamed, Koroma

2015-09-01

Most underdeveloped countries do not meet core disease outbreak surveillance because of the lack of human resources, laboratory and infrastructural facilities. The use of cell phone technology for disease outbreak syndromic surveillance is a new phenomenon in Sierra Leone despite its successes in other developing countries like Sri Lanka. In this study we set to evaluate the effectiveness of using cell phone technology for Ebola hemorrhagic fever syndromic surveillance in a high risked community in Sierra Leone. This study evaluated the effectiveness of using cell phone messaging (text and calls) for community Ebola hemorrhagic fever syndromic surveillance in high risked community in southern Sierra Leone. All cell phone syndromic surveillance data used for this study was reported as cell phone alert messages-texts and voice calls; by the Moyamba District Health Management Team for both Ebola hemorrhagic fever suspect and mortalities. We conducted a longitudinal data analysis of the monthly cumulative confirmed Ebola hemorrhagic fever cases and mortalities collected by both the traditional sentinel and community cell phone syndromic surveillance from August 2014 to October 2014. A total of 129 and 49 Ebola hemorrhagic fever suspect and confirmed cases respectively were recorded using the community Ebola syndromic surveillance cell phone alert system by the Moyamba District Health Management Team in October 2014. The average number of Ebola hemorrhagic fever suspects and confirmed cases for October 2014 were 4.16 (Std.dev 3.76) and 1.58 (Std.dev 1.43) respectively. Thirty-four percent (n=76) of the community Ebola syndromic surveillance cell phone alerts that were followed-up within 24 hours reported Ebola hemorrhagic fever suspect cases while 65.92% (n=147) reported mortality. Our study suggests some form of underreporting by the traditional sentinel Ebola hemorrhagic fever disease surveillance system in Moyamba District southern Sierra Leone for August-September 2014. Cell phone messaging technology can be effectively use as a tool for community epidemic surveillance from peripheral health care facilities to higher levels.

48 CFR 25.003 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Principe, Senegal, Sierra Leone, Solomon Islands, Somalia, Tanzania, Togo, Tuvalu, Uganda, Vanuatu, Yemen..., Rwanda, Samoa, Sao Tome and Principe, Senegal, Sierra Leone, Solomon Islands, Somalia, Tanzania, Togo...

48 CFR 25.003 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... and Principe, Senegal, Sierra Leone, Solomon Islands, Somalia, South Sudan, Tanzania, Timor-Leste..., Sierra Leone, Solomon Islands, Somalia, South Sudan, Tanzania, Timor-Leste, Togo, Tuvalu, Uganda, Vanuatu...

NASA Deputy Administrator Tours Sierra Nevada Space Systems

NASA Image and Video Library

2011-02-05

Sierra Nevada Space Systems chairman Mark Sirangello talks to NASA Deputy Administrator Lori Garver, on Saturday, Feb. 5, 2011, in Louisville, Colo. Sierra Nevada's Dream Chaser spacecraft is under development with support from NASA's Commercial Crew Development Program to provide crew transportation to and from low Earth orbit. NASA is helping private companies develop innovative technologies to ensure that the U.S. remains competitive in future space endeavors. Photo Credit: (NASA/Bill Ingalls)

48 CFR 25.003 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., Sierra Leone, Solomon Islands, Somalia, South Sudan, Tanzania, Timor-Leste, Togo, Tuvalu, Uganda, Vanuatu..., Nepal, Niger, Rwanda, Samoa, Sao Tome and Principe, Senegal, Sierra Leone, Solomon Islands, Somalia...

Potential effects of climate change on streamflow, eastern and western slopes of the Sierra Nevada, California and Nevada

USGS Publications Warehouse

Jeton, A.E.; Dettinger, M.D.; Smith, J. LaRue

1996-01-01

Precipitation-runoff models of the East Fork Carson and North Fork American Rivers were developed and calibrated for use in evaluating the sensitivity of streamflow in the north-central Sierra Nevada to climate change. The East Fork Carson River drains part of the rain-shadowed, eastern slope of the Sierra Nevada and is generally higher than the North Fork American River, which drains the wetter, western slope. First, a geographic information system was developed to describe the spatial variability of basin characteristics and to help estimate model parameters. The result was a partitioning of each basin into noncontiguous, but hydrologically uniform, land units. Hydrologic descriptions of these units were developed and the Precipitation- Runoff Modeling System (PRMS) was used to simulate water and energy balances for each unit in response to daily weather conditions. The models were calibrated and verified using historical streamflows over 22-year (Carson River) and 42-year (American River) periods. Simulated annual streamflow errors average plus 10 percent of the observed flow for the East Fork Carson River basin and plus 15 percent for the North Fork American River basin. Interannual variability is well simulated overall, but, at daily scales, wet periods are simulated more accurately than drier periods. The simulated water budgets for the two basins are significantly different in seasonality of streamflow, sublimation, evapotranspiration, and snowmelt. The simulations indicate that differences in snowpack and snowmelt timing can play pervasive roles in determining the sensitivity of water resources to climate change, in terms of both resource availability and amount. The calibrated models were driven by more than 25 hypothetical climate-change scenarios, each 100 years long. The scenarios were synthesized and spatially disaggregated by methods designed to preserve realistic daily, monthly, annual, and spatial statistics. Simulated streamflow timing was not very sensitive to changes in mean precipitation, but was sensitive to changes in mean temperatures. Changes in annual streamflow amounts were amplified reflections of imposed mean precipitation changes, with especially large responses to wetter climates. In contrast, streamflow amount was surprisingly insensitive to mean temperature changes as a result of temporal links between peak snowmelt and the beginning of warm-season evapotranspiration. Comparisons of simulations driven by temporally detailed climate-model changes in which mean temperature changes vary from month to month and simulations in which uniform climate changes were imposed throughout the year indicate that the snowpack accumulates the influences of short-term conditions so that season average climate changes were more important than shorter term changes.

Health complications of female genital mutilation in Sierra Leone

PubMed Central

Bjälkander, Owolabi; Bangura, Laurel; Leigh, Bailah; Berggren, Vanja; Bergström, Staffan; Almroth, Lars

2012-01-01

Sierra Leone has one of the highest rates of female genital mutilation (FGM) in the world, and yet little is known about the health consequences of the practice. Purpose To explore whether and what kind of FGM-related health complications girls and women in Sierra Leone experience, and to elucidate their health care-seeking behaviors. Patients and methods A feasibility study was conducted to test and refine questionnaires and methods used for this study. Thereafter, a cross-section of girls and women (n = 258) attending antenatal care and Well Women Clinics in Bo Town, Bo District, in the southern region and in Makeni Town, Bombali District, in the northern region of Sierra Leone were randomly selected. Participants answered interview-administrated pretested structured questionnaires with open- ended-questions, administrated by trained female personnel. Results All respondents had undergone FGM, most between 10 and 14 years of age. Complications were reported by 218 respondents (84.5%), the most common ones being excessive bleeding, delay in or incomplete healing, and tenderness. Fever was significantly more often reported by girls who had undergone FGM before 10 years of age compared with those who had undergone the procedure later. Out of those who reported complications, 187 (85.8%) sought treatment, with 89 of them visiting a traditional healer, 75 a Sowei (traditional circumciser), and 16 a health professional. Conclusion The high prevalence rate of FGM and the proportion of medical complications show that FGM is a matter for public health concern in Sierra Leone. Girls who undergo FGM before 10 years of age seem to be more vulnerable to serious complications than those who are older at the time of FGM. It is important that health care personnel are aware of, and look for possible complications from FGM, and encourage girls and women to seek medical care for their problems. PMID:22870046

Evaluating the Spatial Distribution of Toxic Air Contaminants in Multiple Ecosystem Indicators in the Sierra Nevada-Southern Cascades

NASA Astrophysics Data System (ADS)

Nanus, L.; Simonich, S. L.; Rocchio, J.; Flanagan, C.

2013-12-01

Toxic air contaminants originating from agricultural areas of the Central Valley in California threaten vulnerable sensitive receptors including surface water, vegetation, snow, sediments, fish, and amphibians in the Sierra Nevada-Southern Cascades region. The spatial distribution of toxic air contaminants in different ecosystem indicators depends on variation in atmospheric concentrations and deposition, and variation in air toxics accumulation in ecosystems. The spatial distribution of organic air toxics and mercury at over 330 unique sampling locations and sample types over two decades (1990-2009) in the Sierra Nevada-Southern Cascades region were compiled and maps were developed to further understand spatial patterns and linkages between air toxics deposition and ecological effects. Potential ecosystem impacts in the Sierra Nevada-Southern Cascades region include bioaccumulation of air toxics in both aquatic and terrestrial ecosystems, reproductive disruption, and immune suppression. The most sensitive ecological end points in the region that are affected by bioaccumulation of toxic air contaminants are fish. Mercury was detected in all fish and approximately 6% exceeded human consumption thresholds. Organic air toxics were also detected in fish yielding variable spatial patterns. For amphibians, which are sensitive to pesticide exposure and potential immune suppression, increasing trends in current and historic use pesticides are observed from north to south across the region. In other indicators, such as vegetation, pesticide concentrations in lichen increase with increasing elevation. Current and historic use pesticides and mercury were also observed in snowpack at high elevations in the study area. This study shows spatial patterns in toxic air contaminants, evaluates associated risks to sensitive receptors, and identifies data gaps. Future research on atmospheric modeling and information on sources is needed in order to predict which ecosystems are the most sensitive to toxic air contaminants in the Sierra Nevada-Southern Cascades region.

Prevalence and Risk Factors for Human Immunodeficiency Virus (HIV) and Syphilis Infections Among Military Personnel in Sierra Leone.

PubMed

Djibo, Djeneba Audrey; Sahr, Foday; McCutchan, J Allen; Jain, Sonia; Araneta, Maria Rosario G; Brodine, Stephanie K; Shaffer, Richard A

2017-01-01

HIV and syphilis infections are common in military personnel in sub-Saharan Africa, which impact combat preparedness and increase demands on the military health care system. The prevalence of HIV is estimated at 1.5% among the general population (15-49 years of age) of Sierra Leone, and the estimated syphilis prevalence ranged from 1.5% to 5.2% based on regional studies. We examined the prevalence and risk factors for these two common sexually transmitted infections in the Sierra Leone military personnel. This cross-sectional study examined 1157 randomly selected soldiers from the Republic of Sierra Leone Armed Forces in 2013 using computer-assisted personal interviews and rapid testing algorithms. Descriptive statistics and logistic regression models were implemented to identify risk factors for HIV and syphilis separately. The mean age of participants was 38 years, 11.1% were female, and 86.5% were married. The seroprevalence of HIV and syphilis were 3.3% (95% confidence interval [CI]: 2.3%-4.3%) and 7.3% (95% CI: 5.9%-8.8%), respectively. Lower educational attainment in women, multiple sexual partners, unintended sex after alcohol use and use of condoms were independently associated with HIV status (p<0.05). After adjustment, HIV infection was associated with female gender, unintended sex after alcohol use, condom use at last sex, having multiple sexual partnerships in the same week and HIV testing outside of military facilities (p<0.05). Increasing age, positive HIV status and rural regions of residence were associated with syphilis seropositivity. The prevalence of sexually transmitted infections among military personnel was higher than the general population of Sierra Leone. Several high-risk sexual behaviors that expose soldiers to HIV and syphilis could be addressed through prevention interventions. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Petrographic and chemical reconnaissance study of some granitic and gneissic rocks near the San Andreas fault from Bodega Head to Cajon Pass, California

USGS Publications Warehouse

Ross, Donald C.

1972-01-01

This petrographic and chemical study is based on reconnaissance sampling of granitic and related gneissic rock in the California Coast and Transverse Ranges. In the Coast Ranges, granitic rocks are restricted to an elongate belt, the Salinian block, between the San Andreas and Sur-Nacimiento fault zones. These rocks have a considerable compositional range, but are dominantly quartz monzonite and granodiorite. Moist of the Salinian block seems to be a structurally coherent basement block of chemically related granitic rocks. However, on both the east and the west sides of the block, gneiss crops out in abundance; these rocks may be structurally separate from the main part of the Salinian block. In the Transverse Ranges, the granitic and related rocks are dominantly of granodiorite composition, and in many areas granitic and gneissic rocks are intimately intermixed.Chemically the rocks of the California Coast and Transverse Ranges are somewhat intermediate in character between those of the east-central part of the Sierra Nevada batholith and those of the western part of the Sierra Nevada batholith and the southern California batholith. Probably the closest similarity is to the east-central Sierra Nevada rocks, but the rocks of the Coast and Transverse Ranges are somewhat higher in Al2O3 and lower in K2O than Sierran rocks of the comparable SiO2 content.Granitic basement rocks of the Salinian block are now anomalously sandwiched between Franciscan terranes. The petrographic and chemical data are compatible with the concept that the Salinian rocks were originally part of the great batholithic belt along the west coast, which is exemplified by the Sierra Nevada hatholith. It also seems most likely that the Salinian block was transported from somewhere south of the Sierra Nevada batholith by large-scale right-lateral movement along the San Andreas fault zone.

Measuring the Timing, Magnitude, and Rate of Rock uplift of Sierra Madre Mountains with CRN Analysis of Relict Landscapes and Strath Terraces

NASA Astrophysics Data System (ADS)

Schoettle, E.; Burbank, D. W.; Bookhagen, B.

2014-12-01

California's Sierra Madre Mountains lie at the junction of the Coast and Transverse Ranges, where they form an arcuate range crest with peak elevations of nearly 1,800 m. Near the range crest, a gently sloping paleovalley in the Southern Sierra Madre is being consumed by the headward migration of a prominent knickpoint, with an ~250-m-high headwall abutting below the gently sloped paleovalley. This paleovalley at 1400 m elevation and other low-relief, high-elevation remnants in the Sierra Madres at elevations from 800-1400 m show that the range is young enough to have regions not yet in equilibrium with the modern base level and uplift rate. Toward the western end of the Sierra Madre, the Cuyama River cuts a bedrock canyon through the range. The canyon planform describes a meandering river that has now incised ~400 m into the range. The combination of (i) high-altitude, low-relief surfaces in the Sierra Madre including the paleovalley with (ii) a meandering planform that has been incised into bedrock by a transverse river suggests (1) a low-altitude meandering proto-Cuyama river preceded significant rock uplift, and (2) the river's incision records the rock uplift of the range. Using cosmogenic nuclides to measure both the bedrock-lowering rate of the high-elevation paleovalley and the erosion rate of the steep catchment eroding into it, we can place some limits on the timing and magnitude of rock uplift in the range. By dating bedrock straths along the river canyon's walls, we can directly quantify the pace of channel incision. Together these new estimates will yield an improved reconstruction of the timing, magnitude, and rate of rock uplift of the Sierra Madre.

GPS Imaging of Sierra Nevada Uplift

NASA Astrophysics Data System (ADS)

Hammond, W. C.; Blewitt, G.; Kreemer, C.

2015-12-01

Recent improvements in the scope and precision of GPS networks across California and Nevada have allowed for uplift of the Sierra Nevada to be observed directly. Much of the signal, in the range of 1 to 2 mm/yr, has been attributed to lithospheric scale rebound following massive groundwater withdrawal in the San Joaquin Valley in southern California, exacerbated by drought since 2011. However, natural tectonic deformation associated with long term uplift of the range may also contribute to the observed signal. We have developed new algorithms that enhance the signal of Sierra Nevada uplift and improve our ability to interpret and separate natural tectonic signals from anthropogenic contributions. We apply our new Median Interannual Difference Adjusted for Skewness (MIDAS) algorithm to the vertical times series and a inverse distance-weighted median spatial filtering and Delaunay-based interpolation to despeckle the rate map. The resulting spatially continuous vertical rate field is insensitive to outliers and steps in the GPS time series, and omits isolated features attributable to unstable stations or unrepresentative rates. The resulting vertical rate field for California and Nevada exhibits regionally coherent signals from the earthquake cycle including interseismic strain accumulation in Cascadia, postseismic relaxation of the mantle from recent large earthquakes in central Nevada and southern California, groundwater loading changes, and tectonic uplift of the Sierra Nevada and Coast Ranges. Uplift of the Sierra Nevada extends from the Garlock Fault in the south to an indefinite boundary in the north near the latitude of Mt. Lassen to the eastern Sierra Nevada range front in Owen's Valley. The rates transition to near zero in the southern Walker Lane. The eastern boundary of uplift coincides with the highest strain rates in the western Great Basin, suggesting higher normal fault slip rates and a component of tectonic uplift of the Sierra Nevada.

Preliminary assessment of the moth (Lepidoptera: Heterocera) fauna of Rincon de Guadalupe, Sierra de Bacadehuachi, Sonora, Mexico

Treesearch

John D. Palting

2013-01-01

The Sierra de Bacadéhuachi is a poorly sampled extension of the Sierra Madre Occidental (SMO) located in east-central Sonora near the town of Bacadéhuachi. Sampling of moths using mercury vapor and ultraviolet lights occurred in summer and fall 2011, and spring 2012 at Rincón de Guadalupe, located in pine-oak forest at 1680 m elevation. Approximately 400 taxa of moths...

Changes in High Elevation Lake Ecosystems of the Sierra Nevada during the 20th Century: Combining Long-term Monitoring with Paleolimnology

NASA Astrophysics Data System (ADS)

Sickman, J. O.; Heard, A. M.; Rose, N. L.; Bennett, D. M.; Lucero, D. M.; Melack, J. M.; Curtis, J. H.

2014-12-01

High mountain lakes of the Sierra Nevada are excellent indicators of anthropogenic global change due to their limited capacity to buffer acid deposition, their sensitivity to changes in snowpack dynamics and their oligotrophic nutrient status. In this presentation, we examine long-term records of hydrochemistry and biological monitoring at the Emerald Lake watershed to assess whether high elevation lakes of the Sierra Nevada are changing in response to climate change or changes in atmospheric deposition of nutrients and acid. To provide a broader context for these changes, we augment these long-term records with results from paleolimnological analysis that examines changes in nutrient status and acid buffering capacity of Sierra Nevada lakes over the past two millennia. Our research suggests that, although atmospheric deposition is the dominant driver of twentieth century ANC trends, aquatic communities in the Sierra Nevada are responding to combined effects from acidification, climate change, and eutrophication. Early in the twentieth century the primary stressor effecting Sierra Nevada lakes was acid deposition driven by SO2 emissions. As the century and industrialization progressed, NOx levels increased adding a eutrophication stressor while simultaneously contributing to acidification. Effects were further complicated by a warming climate in the late twentieth century, as warmer temperatures may have contributed to the recovery of ANC in lakes via increased weathering rates, while simultaneously enhancing eutrophication effects.

Geology of the Sierra de Fiambala, northwestern Argentina: implications for Early Palaeozoic Andean tectonics

USGS Publications Warehouse

Grissom, G.C.; DeBari, S.M.; Snee, L.W.

1998-01-01

This paper is included in the Special Publication entitled 'The proto- Andean margin of Gondwana', edited by R.J. Pankhurst and C.W. Rapela. Field mapping in conjunction with structural, metamorphic, and geochronological data document the tectono-thermal history of exhumed deep crustal rocks in the Sierra de Fiambala, NW Argentina. The range consists of two structural blocks distinguished by different metasedimentary sequences and different grades of metamorphism. Orthogneiss and paragneiss in the northern structural block may have a Precambrian history. Greenschist- to amphibolite-facies metamorphism, intrusion, and injection magmatization affected all rocks at 540-550 Ma. A subsequent event in the Late Cambrian to Ordovician (c.515 to 470 Ma) involved amphibolite- to granulite-facies metamorphism, mafic intrusion, and deformation, followed by cooling through mid-Palaeozoic time. The emplacement of Carboniferous (325-350 Ma) post-tectonic granites caused reheating and retrogression that was strongest toward the northeast part of the range. The Cambrian, Ordovician, and Carboniferous events in the Sierra de Fiambala were of regional extent as indicated by temporal correlations with events reported for other deep crustal rocks of the northern Sierras Pampeanas. Correlations between periods of intrusion and high-grade metamorphism in the northern Sierras Pampeanas and volcanic-sedimentary events in the adjacent supracrustal exposures confirm that rocks in the northern Sierras Pampeanas formed at deep (10-25 km) structural levels in the early Palaeozoic continental margin of Gondwana.

Moho Structure of the Central Sierra Nevada From an EarthScope Flex Array Deployment

NASA Astrophysics Data System (ADS)

Burdick, S.; Zandt, G.; Gilbert, H.; Jones, C.; Owens, T.

2005-12-01

Findings from the southern Sierra Nevada (south of 37 degrees north) show that the crustal thickness in the southern Sierra Nevada range does not obey an Airy isostasy model. Receiver function data show that the crustal thickness generally increases across the range from the high eastern peaks to the low western foothills, and the Moho discontinuity disappears beneath parts of the western foothills. This disappearance of the Moho has been attributed to the entrainment of the crust into the mantle by the convective removal of the southern batholithic root during the past 3-4 M yrs (Zandt et al., Nature, 2004). Other possible causes of Moho disappearance include a very gradational, or even inverted, impedance contrast due to lower crustal or upper mantle wavespeed anomalies. During the summer of 2005, the Sierra Nevada Earthscope Project (SNEP) has deployed an Earthscope flex array of over forty broadband seismometers with 25 km spacing, designed to constrain lithospheric structure of the central Sierra Nevada between the latitudes of approximately 37 to 38 degrees north. We will report on a receiver function study to better define the boundaries of the Moho "hole" to the north. Initial receiver functions from the first stations deployed mainly on the western and eastern flanks of the range show a northward continuation of both the "hole" under the western margin and a high amplitude Moho under the eastern flank of the range. This new observation suggests either the Moho disappearance is unrelated to the convective removal of the southern root or that root removal has affected the Sierra Nevada significantly farther north than suggested by presently available volcanic and xenolith evidence. Receiver functions collected from SNEP data will be processed into move-out corrected depth stacks in order to present a more complete map of Moho depth and amplitude beneath the region. To quantify the range of impedance contrasts capable of producing the observed variability in Moho amplitude, observed receiver function arrivals will be compared to synthetic examples calculated for a range of lower crustal and upper mantle wavespeeds. In conjunction with other studies these results should lead to a better understanding of the scale and processes associated with a young lithospheric foundering event.

The burden of musculoskeletal disease in Sierra Leone.

PubMed

Elliott, Iain S; Groen, Reinou S; Kamara, Thaim B; Ertl, Allison; Cassidy, Laura D; Kushner, Adam L; Gosselin, Richard A

2015-01-01

Musculoskeletal disease is a major cause of disability in the global burden of disease, yet data regarding the magnitude of this burden in developing countries are lacking. The Surgeons OverSeas Assessment of Surgical Need (SOSAS) survey was designed to measure the incidence and prevalence of surgically treatable conditions, including musculoskeletal conditions, in patients in low- and middle-income countries, and was administered in the West African nation of Sierra Leone in 2012. We attempted to quantify the burden of potentially treatable musculoskeletal conditions in patients in Sierra Leone. A cross-sectional two-stage cluster-based survey was performed in Sierra Leone using the SOSAS. Two individuals from each randomly selected household underwent a verbal head to toe examination. The musculoskeletal-related questions from the SOSAS survey in Sierra Leone were analyzed to determine the prevalence of musculoskeletal problems in the study population. Prevalence is reported as the number of respondents with a musculoskeletal problem now and number of respondents with a musculoskeletal problem during the past year. Respondents had "no need" for care, they "received care", or they faced a barrier that prevented them from receiving care. One thousand eight hundred seventy-five households were targeted, with 1843 undergoing the survey, which yielded 3645 individual respondents. Of the individual respondents, 462 (n=3645; 12.6% of total; 95% CI, 12%-13%) had a traumatic musculoskeletal problem during the past year, and 236 (n=3645; 6% of total; 95% CI, 5%-7%) respondents had a musculoskeletal problem of nontraumatic etiology. Of respondents with either a traumatic or nontraumatic musculoskeletal problem, 359 (n=562; 63.9% of total; 95% CI, 59.5-68.3%) needed care but were unable to receive it with the major barrier reported as financial. Resource allocation decisions in global health are made based on burden of disease data in low- and middle-income countries. The data provided here for Sierra Leone may offer some generalizable insight into the scope of the burden of musculoskeletal disease for low- and middle-income countries, especially in Sub-Saharan Africa, and provide concrete evidence that musculoskeletal health should be included in the global health discussion. However, there may be important differences across countries in this region, and further study to elucidate these differences seems critical given the large burden of disease and the limited resources available in these regions to manage it.

Mitochondrial DNA control region sequences from Nairobi (Kenya): inferring phylogenetic parameters for the establishment of a forensic database.

PubMed

Brandstätter, Anita; Peterson, Christine T; Irwin, Jodi A; Mpoke, Solomon; Koech, Davy K; Parson, Walther; Parsons, Thomas J

2004-10-01

Large forensic mtDNA databases which adhere to strict guidelines for generation and maintenance, are not available for many populations outside of the United States and western Europe. We have established a high quality mtDNA control region sequence database for urban Nairobi as both a reference database for forensic investigations, and as a tool to examine the genetic variation of Kenyan sequences in the context of known African variation. The Nairobi sequences exhibited high variation and a low random match probability, indicating utility for forensic testing. Haplogroup identification and frequencies were compared with those reported from other published studies on African, or African-origin populations from Mozambique, Sierra Leone, and the United States, and suggest significant differences in the mtDNA compositions of the various populations. The quality of the sequence data in our study was investigated and supported using phylogenetic measures. Our data demonstrate the diversity and distinctiveness of African populations, and underline the importance of establishing additional forensic mtDNA databases of indigenous African populations.

Meso to Neoproterozoic layered mafic-ultramafic rocks from the Virorco back-arc intrusion, Argentina

NASA Astrophysics Data System (ADS)

Ferracutti, Gabriela; Bjerg, Ernesto; Hauzenberger, Christoph; Mogessie, Aberra; Cacace, Francisco; Asiain, Lucía

2017-11-01

The Virorco layered mafic-ultramafic intrusion is part of a belt that extends over 100 km from NE to SW in the Eastern Sierras Pampeanas of San Luis, Argentina. The rocks of this belt carry a Fe-Cu-Ni sulphide mineralization in veins and as disseminated and massive ore. Platinum group minerals are associated with the sulphides. The Virorco intrusion exhibits modal, textural and cryptic layering. New results allow the characterization of six layered units (Modal Layered Unit, Pyroxenitic Macro-Layered Unit, Gabbroic Unit, Banded Unit, Hornblende Norite Unit and Gabbronorite Unit) present in three sectors of the intrusion (Eastern, Central and Western). The units from the Western Sector (Banded Unit, Hornblende Norite Unit and Gabbronorite Unit) and the Modal Layered Unit from the Eastern Sector belong to the Marginal Border Series of the intrusion. Meanwhile, the Central sector units (Pyroxenitic Macro-Layered Unit and Gabbroic Unit) are from the Layered Series. The presence of crescumulate texture (Modal Layered Unit) and colloform banding (Banded Unit) are evidences of "in situ" crystallization due to supercooling of a MgO-rich hydrated mafic magma, where cooling proceeded from the walls towards the interior of the magma chamber. In previous studies the mafic-ultramafic rocks have been considered to be Cambrian to Ordovician. Here we present a Sm-Nd whole rock isochron which shows that the formation age of these intrusions is 1002 ± 150 Ma and that the protolith age of the Pringles Metamorphic Complex metasedimentary rocks is 1289 ± 97 Ma. Our study also indicates that the San Luis mafic-ultramafic layered intrusives most probably formed in a back-arc tectonic setting, from an enriched sub-continental mantle, influenced by a subducting slab and/or crust injection into the Pampia Terrane prior to its collision with the Rio de la Plata Craton.

War and deforestation in Sierra Leone

NASA Astrophysics Data System (ADS)

Burgess, Robin; Miguel, Edward; Stanton, Charlotte

2015-09-01

The impact of armed conflict on the environment is of major public policy importance. We use a geographically disaggregated dataset of civil war violence together with satellite imagery of land cover to test whether war facilitated or prevented forest loss in Sierra Leone. The conflict data set allows us to establish where rebel groups were stationed and where battles and attacks occurred. The satellite data enables to us to monitor the change in forest cover (total, primary, and secondary) in all of Sierra Leone’s 151 chiefdoms, between 1990 (prior to the war) and 2000 (just prior to its end). The results suggest that conflict in Sierra Leone acted as a brake on local deforestation: conflict-ridden areas experienced significantly less forest loss relative to their more conflict-free counterparts.

El Morro caldera (33° 10‧ S, 66° 24‧ W), San Luis, Argentina: An exceptional case of fossil pre-collapse updoming

NASA Astrophysics Data System (ADS)

Sruoga, P.; Ibañes, O. D.; Japas, M. S.; Urbina, N. E.

2017-05-01

Volcanism at Sierra del Morro represents the final stages of the flat-slab related magmatism in the easternmost San Luis Neogene Volcanic Belt. This 80 km-long NW-WNW-trending belt tracks the episodic inland migration of both magmatism and tectonic deformation since 18 Ma. The Sierra del Morro stands out in the Eastern Sierras Pampeanas as a metamorphic block uplifted during the Late Miocene-Pleistocene by a combination of magma injection and tectonic deformation. Although sequences that preserve stages of basement updoming are not often preserved, exposures in Sierra del Morro are exception in providing key evidence and insight into the involved processes. Based on the comprehensive study of volcanic stratigraphy and structures, the reconstruction of the volcanic architecture has been carried out. We infer a three stage evolution of the El Morro caldera as follows: 1) pre-collapse updoming and volcanism, 2) collapse caldera formation and 3) post-caldera volcanism. The ascent of magma is recorded in small tumescence sites, strongly controlled by oblique transtensional WNW-NW and ENE-striking brittle-ductile megashear zones. Even though the area affected by tumescence was large, magma injection progressed only locally. At Cerros Guanaco and Pampa, metamorphic rocks were updomed and strongly brecciated, whereas at Sierra del Morro magma was emplaced as pre-collapse domes with associated block-and-ash flows, ignimbrite caldera-forming eruptions and post-caldera lava domes and dykes. The caldera is located in the intersection of two major oblique transtensional WNW-NW and ENE-trending brittle-ductile megashear zones, where the highest positive dilatation occurred.

Nationally representative household survey of surgery and mortality in Sierra Leone.

PubMed

Kwon, Steve; Groen, Reinou S; Kamara, Thaim B; Cassidy, Laura D; Samai, Mohamed; Yambasu, Sahr E; Kushner, Adam L

2013-08-01

There is limited evidence to characterize the burden of unmet need of surgical diseases in low- and middle-income countries. The purpose of this study was to determine rate of deaths attributable to a surgical condition and reasons for not seeking surgical care in Sierra Leone. The Surgeons OverSeas Assessment of Surgical Need (SOSAS) is a survey tool developed collaboratively to be used for cross-sectional data collection of the prevalence of surgical conditions in any country. A population-weighted cluster-sample household survey was conducted throughout Sierra Leone in 2012 using the SOSAS survey tool. Total of 1,840 households (11,870 individuals) were sampled, yielding a 98.3 % response rate. Overall, there were 709 total deaths reported (6.0 %). The mean age at death was 36.4 ± 30.1 years: 330 (46.6 %) were female. Most deaths occurred at home (58.1 % vs. 34.1 % in hospitals). Of the 709 deaths, 237 (33.4 %) were associated with conditions included in our predefined surgical disease category. Abdominal distension/pain was the most commonly associated surgical condition (13.9 %) followed by perinatal bleeding/illness (6.0 %). Among the 237 with surgical conditions, 51 (21.9 %) did not seek medical care, most commonly because of a lack of money (35.3 %) or inability to provide timely care (37.3 %). A large proportion of deaths in Sierra Leone was associated with surgical conditions, the majority of which did not undergo surgical intervention. Our results indicate that to remove barriers to effective surgical care in Sierra Leone policymakers should first focus on relieving financial burdens and increasing access to timely surgical care.

Exploring female genital cutting among west African immigrants.

PubMed

Akinsulure-Smith, Adeyinka M

2014-06-01

Although many African women immigrate to the United States from countries with high prevalence rates for female genital cutting (FGC), there has been limited research exploring the incidence and impact of FGC among this growing immigrant population. This pilot study sought to examine the experiences of FGC among West African immigrant women in the US. Of the 23 participants, 7 reported a history of FGC, with Muslim participants reporting significantly higher rates of FGC than Christians (Fisher's Exact = .045). Most of the women who had experienced FGC were from Sierra Leone (Fisher's Exact = .027). Limitations of the study are discussed along with suggestions for future research aimed at understanding the impact of FGC, reducing the prevalence and demand for FGC among African immigrant women and improving the health and quality of life of women who have undergone the procedure.

The Tunas Formation (Permian) in the Sierras Australes foldbelt, east central Argentina: evidence for syntectonic sedimentation in a foreland basin

NASA Astrophysics Data System (ADS)

Lopez-Gamundi, O. R.; Conaghan, P. J.; Rossello, E. A.; Cobbold, P. R.

1995-04-01

The Tunas Formation, extensively exposed in the Sierras Australes foldbelt of eastern central Argentina, completes the sedimentation of the Gondwanan (Late Carboniferous-Permian) sequence, locally known as the Pillahuincó Group. The underlying units of the Group show an integrated depositional history which can be explained in terms of glaciomarine sedimentation (Sauce Grande Formation) and postglacial transgression (Piedra Azul and Bonete Formations). This succession also has a rather uniform quartz-rich, sand-sized composition indicative of a cratonic provenance from the Tandilia Massif to the northeast. Early to Late Permian deformation folded and thrusted the southwestern basin margin (Sierras Australes) and triggered the deposition of a 1,500 m — thick, synorogenic prograding wedge, the Tunas Formation, in the adjacent foreland basin (Sauce Grande or Claromecó Basin). Sandstone detrital modes for the Tunas deposits show moderate to low contents of quartz and abundant lithics, mostly of volcanic and metasedimentary origin. Paleocurrents are consistently from the SW. Tuffs interbedded with sandstones in the upper half of Tunas Formation (Early — early Late? Permian) are interpreted as being derived from volcanic glass-rich tuffs settled in a body of water. Extensive rhyolitic ignimbrites and consanguineous airborne tuffaceous material erupted in the northern Patagonian region during that period. The age constraints and similarities in composition between these volcanics and the tuffaceous horizons present in the Sauce Grande, Parana and Karoo Basins suggest a genetic linkage between these two episodes. The intimate relationship between volcanic activity inboard of the paleo-Pacific margin, deformation in the adjacent orogenic belt and subsidence and sedimentation in the contiguous foreland basin constitutes a common motif in the Sauce Grande and Karoo Basins of southwestern Gondwana.

NASA Deputy Administrator Tours Sierra Nevada Space Systems' Dre

NASA Image and Video Library

2011-02-05

NASA Deputy Administrator Lori Garver talks during a press conference with Sierra Nevada's Dream Chaser spacecraft in the background on Saturday, Feb. 5, 2011, at the University of Colorado at Boulder. Sierra Nevada's Dream Chaser spacecraft is under development with support from NASA's Commercial Crew Development Program to provide crew transportation to and from low Earth orbit. NASA is helping private companies develop innovative technologies to ensure that the U.S. remains competitive in future space endeavors. Photo Credit: (NASA/Bill Ingalls)

NASA Deputy Administrator Tours Sierra Nevada Space Systems' Dre

NASA Image and Video Library

2011-02-05

Sierra Nevada's Dream Chaser spacecraft is seen as NASA Deputy Administrator Lori Garver talks during a press conference on Saturday, Feb. 5, 2011, at the University of Colorado at Boulder. Sierra Nevada's Dream Chaser spacecraft is under development with support from NASA's Commercial Crew Development Program to provide crew transportation to and from low Earth orbit. NASA is helping private companies develop innovative technologies to ensure that the U.S. remains competitive in future space endeavors. Photo Credit: (NASA/Bill Ingalls)

Terminal Forecast Reference Notebook (TFRN) for Luke AFB, Arizona,

DTIC Science & Technology

1980-06-02

due west of the base; the Sierra Estrella , 4,512 feet, about 12 miles to the south; the Phoenix Mountains, 2,740 feet, about 20 miles to the east...from any other direction will usually miss the base by more than 5 nautical miles because of the steering effect of the Sierra Estrella and the White...does the Sierra Estrella between 152 and 210 degrees. Most radar signal blocking can be eliminated, with the exception of the White Tanks, by raising

Unlikely (but perfect) partners in the fight for the green energy and fair trade economy.

PubMed

Redmond, Fred

2009-01-01

A priority for the United Steelworkers the last several years has been its work with the Sierra Club as part of the Blue Green Alliance. By working with our unconventional allies, we impacted the most important general election in any of our lifetimes. Now, smart investments in renewable energy and fuel-efficient cars are cornerstones of the Obama administration's economic recovery plan. The other priority issue when we began the Blue Green Alliance was fair trade. It still is a priority.

Lassa hemorrhagic fever in a late term pregnancy from northern sierra leone with a positive maternal outcome: case report

PubMed Central

2011-01-01

Lassa fever (LF) is a devastating viral disease prevalent in West Africa. Efforts to take on this public health crisis have been hindered by lack of infrastructure and rapid field deployable diagnosis in areas where the disease is prevalent. Recent capacity building at the Kenema Government Hospital Lassa Fever Ward (KGH LFW) in Sierra Leone has lead to a major turning point in the diagnosis, treatment and study of LF. Herein we present the first comprehensive rapid diagnosis and real time characterization of an acute hemorrhagic LF case at KGH LFW. This case report focuses on a third trimester pregnant Sierra Leonean woman from the historically non-endemic Northern district of Tonkolili who survived the illness despite fetal demise. Employed in this study were newly developed recombinant LASV Antigen Rapid Test cassettes and dipstick lateral flow immunoassays (LFI) that enabled the diagnosis of LF within twenty minutes of sample collection. Deregulation of overall homeostasis, significant hepatic and renal system involvement, and immunity profiles were extensively characterized during the course of hospitalization. Rapid diagnosis, prompt treatment with a full course of intravenous (IV) ribavirin, IV fluids management, and real time monitoring of clinical parameters resulted in a positive maternal outcome despite admission to the LFW seven days post onset of symptoms, fetal demise, and a natural still birth delivery. These studies solidify the growing rapid diagnostic, treatment, and surveillance capabilities at the KGH LF Laboratory, and the potential to significantly improve the current high mortality rate caused by LF. As a result of the growing capacity, we were also able to isolate Lassa virus (LASV) RNA from the patient and perform Sanger sequencing where we found significant genetic divergence from commonly circulating Sierra Leonean strains, showing potential for the discovery of a newly emerged LASV strain with expanded geographic distribution. Furthermore, recent emergence of LF cases in Northern Sierra Leone highlights the need for superior diagnostics to aid in the monitoring of LASV strain divergence with potentially increased geographic expansion. PMID:21843352

Lassa hemorrhagic fever in a late term pregnancy from northern Sierra Leone with a positive maternal outcome: case report.

PubMed

Branco, Luis M; Boisen, Matt L; Andersen, Kristian G; Grove, Jessica N; Moses, Lina M; Muncy, Ivana J; Henderson, Lee A; Schieffellin, John S; Robinson, James E; Bangura, James J; Grant, Donald S; Raabe, Vanessa N; Fonnie, Mbalu; Zaitsev, Eleina M; Sabeti, Pardis C; Garry, Robert F

2011-08-15

Lassa fever (LF) is a devastating viral disease prevalent in West Africa. Efforts to take on this public health crisis have been hindered by lack of infrastructure and rapid field deployable diagnosis in areas where the disease is prevalent. Recent capacity building at the Kenema Government Hospital Lassa Fever Ward (KGH LFW) in Sierra Leone has lead to a major turning point in the diagnosis, treatment and study of LF. Herein we present the first comprehensive rapid diagnosis and real time characterization of an acute hemorrhagic LF case at KGH LFW. This case report focuses on a third trimester pregnant Sierra Leonean woman from the historically non-endemic Northern district of Tonkolili who survived the illness despite fetal demise. Employed in this study were newly developed recombinant LASV Antigen Rapid Test cassettes and dipstick lateral flow immunoassays (LFI) that enabled the diagnosis of LF within twenty minutes of sample collection. Deregulation of overall homeostasis, significant hepatic and renal system involvement, and immunity profiles were extensively characterized during the course of hospitalization. Rapid diagnosis, prompt treatment with a full course of intravenous (IV) ribavirin, IV fluids management, and real time monitoring of clinical parameters resulted in a positive maternal outcome despite admission to the LFW seven days post onset of symptoms, fetal demise, and a natural still birth delivery. These studies solidify the growing rapid diagnostic, treatment, and surveillance capabilities at the KGH LF Laboratory, and the potential to significantly improve the current high mortality rate caused by LF. As a result of the growing capacity, we were also able to isolate Lassa virus (LASV) RNA from the patient and perform Sanger sequencing where we found significant genetic divergence from commonly circulating Sierra Leonean strains, showing potential for the discovery of a newly emerged LASV strain with expanded geographic distribution. Furthermore, recent emergence of LF cases in Northern Sierra Leone highlights the need for superior diagnostics to aid in the monitoring of LASV strain divergence with potentially increased geographic expansion.

Forest management for water: a hydro-ecological modeling exercise of headwater catchments in the mixed-conifer belt of the Sierra Nevada

NASA Astrophysics Data System (ADS)

Saksa, P. C.; Bales, R. C.; Ray, R. L.

2011-12-01

Hydro-ecological modeling provides a cost-effective method for evaluating the effects of vegetation change on water cycling within a catchment. In mountain watersheds, change in forest vegetation not only has direct effects on transpiration rates, but also energy exchanges that influence patterns of snow ablation. In this study, treatment scenarios were implemented using the Regional Hydro-Ecological Simulation System (RHESSys) to estimate impacts on key elements of the hydrologic cycle affected by forest harvesting - snowpack accumulation, ablation, transpiration, and streamflow. Twelve headwater catchments (0.5 - 2.6 km2, 1460 - 2450m) in the mixed-conifer zone of the central Sierra Nevada, within the Sierra and Tahoe National Forests, were included for analysis. These research sites are part of the Sierra Nevada Adaptive Management Project (SNAMP), located in the headwaters of the American and Merced Rivers, and the Southern Sierra Critical Zone Observatory (CZO) in the Kings River basin. Two methods of forest harvesting were simulated in the study watersheds: 1) uniform canopy thinning, through reduction of Leaf Area Index (LAI) values and 2) strip-cut treatments, suggested as the best method for retaining snowpack. Results from this study compare the influence of vegetation on water cycle dynamics through the two harvesting treatments, initial vegetation densities, and individual catchment size. Model simulations for pre-treatment snow depth, soil moisture, and streamflow were validated with SNAMP and CZO in-situ measurements. Preliminary results show that a linear reduction of forest canopy reduces transpiration accordingly, but produces a non-linear increase in streamflow. Peak discharges also increased, occurring earlier in the spring and having more pronounced effects in the smaller catchments. Based on these results, harvesting thresholds required for obtaining increases in water yield are evaluated. Investigating the impact of forest management on these elements of the hydrologic cycle is essential in the mountain west, where ecosystem services are provided by the snowpack acting as a natural water reservoir, and streamflow which supplies a significant portion of water for hydropower, agricultural irrigation, and urban areas during the spring melt period.

LANDSAT-D investigations in snow hydrology. [Sierra Nevada Mountains, California

NASA Technical Reports Server (NTRS)

Dozier, J.

1983-01-01

Two tapes of the southern Sierra Nevada study area were received and the TM data are being registered to digital data. The spectral, spatial, temporal, and economic characteristics of data from LANDSAT 4 TM and MSS were compared with those of NOAA-r AVHRR data for snow cover mapping. An atmospheric radiative transfer model which accounts for both the zenith and aximuth variation in the radiative field is presented and its advantages are discussed. A Monte Carlo method for solving the atmospheric correction problem for an inhomogeneous surface is also considered.

Data on snow chemistry of the Cascade-Sierra Nevada Mountains

USGS Publications Warehouse

Laird, L.B.; Taylor, Howard E.; Lombard, R.E.

1986-01-01

Snow chemistry data were measured for solutes found in snow core samples collected from the Cascade-Sierra Nevada Mountains from late February to mid-March 1983. The data are part of a study to assess geographic variations in atmospheric deposition in Washington, Oregon, and California. The constituents and properties include pH and concentrations of hydrogen ion, calcium, magnesium, sodium, potassium, chloride, sulfate, nitrate, fluoride, phosphate, ammonium, iron, aluminum, manganese, copper, cadmium, lead, and dissolved organic carbon. Concentrations of arsenic and bromide were below the detection limit. (USGS)

Getting the 'blues': the existence, diffusion and influence of pornography on young peoples' sexual health in Sierra Leone.

PubMed

Day, Andrea

2014-01-01

While substantial research has examined the effects of pornography on young people in developed societies, existing studies fall short in addressing how sexually-explicit material affects young people in developing countries. The importance of such knowledge increases as the globalising effects of technology expand young peoples' access and exposure to pornography. During the summer of 2012, a study was undertaken in Sierra Leone examining factors affecting young peoples' sexual and reproductive health. The research assessed the influence of HIV knowledge, communication about sex, civil war and contraception myths on sexual behaviours, while remaining open to unanticipated factors. During data collection, respondents identified pornography, also called blues, as an influential factor, detailing its newfound accessibility driven by improved access to information and communication technologies in the country. Respondents also addressed several presumed ways in which pornography impacts young peoples' decisions about sexual health. The following study examines perceived effects of young peoples' exposure to pornography based on existing literature. It then outlines the findings of research conducted in Sierra Leone, drawing on primary data from the respondents and relevant published literature and concludes with proposals for addressing its negative effects.

Mountain Meadows and their contribution to Sierra Nevada Water Resources

NASA Astrophysics Data System (ADS)

Cornwell, K.; Brown, K.; Monohan, C.

2007-12-01

Human alterations of California's waterscape have exploited rivers, wetlands and meadows of the Sierra Nevada. A century of intensive logging, mining, railroad building, development, fire suppression, and grazing by sheep and cattle has left only 25 percent "intact" natural habitat in the Sierra Nevada (SNEP 1995). Much of this intact habitat occurs at higher elevations, often in non-forested alpine or in less productive forests and woodlands where mountain meadows exist. Mountain meadows serve many ecological functions including habitat for threatened and endangered terrestrial and aquatic species, and are considered to be essential physical components to watershed function and hydrology with significant water storage, filtration and flood attenuation properties. This study evaluates the physical characteristics and hydrologic function of Clarks Meadow located in northern Sierra Nevada, Plumas County, California. In 2001, Clarks Meadow received significant restoration work in the upstream half of the meadow which diverted the stream from an incised channel to a shallow remnant channel, creating a stable channel and reconnecting the groundwater table to the stream. No restoration work was done in the lower half of Clarks Meadow where the stream still flows through an incised channel. Clarks Meadow offers a unique opportunity to study both a restored, hydrologically functional meadow and an incised, hydrologically disconnected stretch of the same stream and meadow. The physical characteristics of Clarks Meadows that were measured include surface area, subsurface thickness, porosity and permeability of subsurface materials, potential water storage volume, and surface infiltration rates. The goal of this study is to refine hydrologic characterization methods, quantify water storage potential of a healthy, non-incised meadow and assess its role in attenuating flood flows during high discharge times. Initial results suggest that significant subsurface storage volume is available in the meadow. Incising conditions in the unstable lower channel tends to dewater the lower portion of the meadow which encourages bank erosion through piping and corrasion. This study addresses questions that have broad implications for water management throughout the state because much of California gets water from Sierra high elevation watersheds in which meadows are thought to play a critical role in sustained long-term hydrologic function. The results of this study will be used to inform Integrated Regional Water Management Plans throughout Northern California.

Interactions between cold and water limitation along a climate gradient produce sharp thresholds in ecosystem type, carbon balance, and water cycling

NASA Astrophysics Data System (ADS)

Kelly, A. E.; Goulden, M.; Fellows, A. W.

2013-12-01

California's Mediterranean climate supports a broad diversity of ecosystem types, including Sequoia forests in the mid-montane Sierra Nevada. Understanding how winter cold and summer drought interact to produce the lush forest in the Sierra is critical to predicting the impacts of projected climate change on California's ecosystems, water supply, and carbon cycling. We investigated how smooth gradients of temperature and water availability produced sharp thresholds in biomass, productivity, growing season, water use, and ultimately ecosystem type and function. We used the climate gradient of the western slope of the Sierra Nevada as a study system. Four eddy covariance towers were situated in the major ecosystem types of the Sierra Nevada at approximately 800-m elevation intervals. Eddy flux data were combined with remote sensing and direct measurements of biomass, productivity, soil available water, and evapotranspiration to understand how weather and available water control ecosystem production and function. We found that production at the high elevation lodgepole site at 2700 m was strongly limited by winter cold. Production at the low elevation oak woodland site at 400 m was strongly limited by summer drought. The yellow pine site at 1200 m was only 4 °C cooler than the oak woodland site, yet had an order of magnitude more biomass and productivity with year-round growth. The mixed conifer site at 2000 m is 3.5 °C warmer than the lodgepole forest, yet also has higher biomass, ten times higher productivity, and year-round growth. We conclude that there is a broad climatological 'sweet spot' within the Sierra Nevada, in which the Mediterranean climate can support large-statured forest with high growth rates. The range of the mid-elevation forest was sharply bounded by water limitation at the lower edge and cold limitation at the upper edge despite small differences in precipitation and temperature across these boundaries. Our results suggest that small changes in precipitation or winter warming could markedly alter ecosystem structure and function as well as carbon and water cycling in the Sierra Nevada.

American Society of Hand Therapists

MedlinePlus

... Seychelles Sierra Leone Singapore Sint Maarten Slovakia Slovenia Solomon Islands Somalia South Africa South Georgia and the ... Seychelles Sierra Leone Singapore Sint Maarten Slovakia Slovenia Solomon Islands Somalia South Africa South Georgia and the ...

Snow Coverage Analysis Using ASTER over the Sierra Nevada Mountain Range

NASA Astrophysics Data System (ADS)

Ross, B.

2017-12-01

Snow has strong impacts on human behavior, state and local activities, and the economy. The Sierra Nevada snowpack is California's most important natural reservoir of water. Such snow is melting sooner and faster. A recent California drought study showed that there was a deficit of 1.5 million acre-feet of water in 2014 due to the fast melting rates. Scientists have been using the Moderate Resolution Imaging Spectrometer (MODIS) which is available at the spatial resolution of 500-meter, to analyze the changes in snow coverage. While such analysis provides us with the valuable information, it would be more beneficial to employ the imageries at a higher spatial resolution for snow studies. Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER), which acquires the high-resolution imageries ranging from 15-meter to 90-meter, has recently become freely available to the public. Our study utilized two scenes obtained from ASTER to investigate the changes in snow extent over the Sierra Nevada's mountain area for an 8-year period. These two scenes were collected on April 11, 2007 and April 16, 2015 covering the same geographic region. Normalized Difference Snow Index (NDSI) was adopted to delineate the snow coverage in each scene. Our study shows a substantial decrease of snow coverage in the studied geographic region by pixel count.

Estimating soil hydrological response by combining precipitation-runoff modeling and hydro-functional soil homogeneous units

NASA Astrophysics Data System (ADS)

Aroca-Jimenez, Estefania; Bodoque, Jose Maria; Diez-Herrero, Andres

2015-04-01

Flash floods constitute one of the natural hazards better able to generate risk, particularly with regard to Society. The complexity of this process and its dependence on various factors related to the characteristics of the basin and rainfall make flash floods are difficult to characterize in terms of their hydrological response.To do this, it is essential a proper analysis of the so called 'initial abstractions'. Among all of these processes, infiltration plays a crucial role in explaining the occurrence of floods in mountainous basins.For its characterization the Green-Ampt model , which depends on the characteristics of rainfall and physical properties of soil has been used in this work.This is a method enabling to simulate floods in mountainous basins where hydrological response is sub-daily. However, it has the disadvantage that it is based on physical properties of soil which have a high spatial variability. To address this difficulty soil mapping units have been delineated according to the geomorphological landforms and elements. They represent hydro-functional mapping units that are theoretically homogeneous from the perspective of the pedostructure parameters of the pedon. So the soil texture of each homogeneous group of landform units was studied by granulometric analyses using standarized sieves and Sedigraph devices. In addition, uncertainty associated with the parameterization of the Green-Ampt method has been estimated by implementing a Monte Carlo approach, which required assignment of the proper distribution function to each parameter.The suitability of this method was contrasted by calibrating and validating a hydrological model, in which the generation of runoff hydrograph has been simulated using the SCS unit hydrograph (HEC-GeoHMS software), while flood wave routing has been characterized using the Muskingum-Cunge method. Calibration and validation of the model was from the use of an automatic routine based on the employ of the search algorithm known as univariate gradient, while the objective function to be used was the percentage of error in the flow-peak of the hydrograph. The methodology proposed here was implemented in the torrential Venero Claro basin, which is a tributary of the Alberche river on its right bank, located in the Sierra del Valle (eastern foothills of the Sierra de Gredos, Spanish Central System). Currently this basin has an active network of six rainfall gauges, one stream gauging, three complete weather stations and one weather X-band radar. This hydrologic instrumentation makes this basin, with its 15 km², is one of the most densely instrumented basins from a hydrological and meteorological point of view in Spain.

Sierra Leone Estuary

NASA Image and Video Library

2014-02-05

This image acquired by NASA Terra spacecraft is of the Sierra Leone estuary, which became a focal point for trade and interaction between Africans and Europeans because of its exceptional harbor, starting in the mid-15th century.

75 FR 56980 - Sierra County Resource Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-17

... Committee Act. The purpose of the meeting is to discuss projects submitted for funding and the expenditure of Title II funds benefiting National Forest System lands in Sierra County. DATES: The meeting will...

75 FR 17896 - Sierra County, CA, Resource Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-08

... issues relating to implementing the Secure Rural Schools and Community Self-Determination Act of 2000... National Forest System lands on the Humboldt- Toiyabe, Plumas and Tahoe National Forests in Sierra County...

75 FR 22100 - Sierra County, CA, Resource Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-27

... issues relating to implementing the Secure Rural Schools and Community Self Determination Act of 2000... National Forest System lands on the Humboldt-Toiyabe, Plumas and Tahoe National Forests in Sierra County...

Interagency technical consultation on improving mortality reporting in Sierra Leone: meeting report

PubMed Central

Asfaw, Yonas; Boateng, Isaac; Calderon, Mauricio; Caleo, Grazia; Conteh, Allan; Conteh, Salifu; Dafae, Foday; Dey, Achintya; Duffy, Nadia; Davies, Daffney; Fatoma, Patrick; Fleming, John; Gogra, Boima; Gorina, Yelena; Grigoryan, Anna; Hersey, Sara; Hoare, Sam; Jabbi, Sonnia-Magba Bu-Buakei; Jambai, Amara; Jasperse, Joseph; Kaiser, Reinhard; Kallon, Gandi; Kamara, Ansumana; Kamara, Fatmata Zara; Kamara, Isata Pamela; Kamara, Wogba; Kandeh, Joseph; Kanu, Mustapha; Kargbo, Mabinty; Kargbo, Samuel; Konie, Richard; Kuyembeh, Simeon; Lansana, Patrick; Mclysaght, Fiona; McCann, Sheena; Nallo, Alhaji Samuka; Ngai, Stephanie; Nichols, Erin; Njuguna, Charles; O-Tipo, Shikanga; Parker, Sulaiman; Rafique, Nuzhat; Redd, John; Samba, Thomas; Souza, Kerry; Tran, Alex; Younge, Chief Mathew Gibao

2017-01-01

By the end of the Ebola epidemic, death reporting in Sierra Leone (SL) became more acceptable amongst local populations, with nearly all deaths being reported to the Ebola hot line alert centers. To continue the positive momentum generated by the epidemic, the Sierra Leone Ministry of Health and Sanitation (MoHS) and the US Centers for Disease Control and Prevention (CDC) organized and conducted the two-day Inter-agency Consultations on Improving Mortality Reporting in Sierra Leone (Consultations). In conjunction with the Consultations, participants were also offered a one-day, in-person training on the major components, characteristics, and uses of a national Civil Registration and Vital Statistics (CRVS) system. To understand processes used by governmental and non-governmental organizations in collection of death data before and during the Ebola epidemic, and to develop recommendations on improving death reporting and CRVS in Sierra Leone. The Inter-agency Consultations were conducted in person over two days in October, 2015. Real-time notes were kept by CDC staff for later abstraction and summarizing. Presenters agreed to share their materials (usually PowerPoint presentations) and approved the summaries. Challenges to implementation and suggestions for improving death reporting were drawn from the presentations and from anonymous suggestions collected at the end of each of three days of the Consultations. The Consultations attracted more than 80 participants from 28 Sierra Leone governmental, business, and other non-governmental organizations. Over the course of 18 presentations, participants presented and discussed the ways deaths were reported before and during the Ebola epidemic and ways in which the CRVS in Sierra Leone might be improved. The presentations made clear the need to improve death reporting in order to improve the health status of Sierra Leone. Many presenters and participants discussed the challenges to improvements, including lack of infrastructure and country diversity. In addition, participants generally agreed upon the need for improving the government’s understanding of the benefits of death reporting at multiple levels: from local chiefdom authorities and councils to the community and individual families. Despite the many challenges identified, all participants stressed the need for modernizing and improving death registration in Sierra Leone. The recommendations from the presentations and notes collected at the end of each day can be categorized within the following five domains: capacity building (organizational, staffing, infrastructure, policies, guidelines and tools), awareness and sensitization (including strategies to use best practices and emerging technologies), political will (governmental support and prioritization), funding (providing resources to achieve sustainability), and monitoring and evaluation (developing charts of existing death reporting pathways and identifying challenges).

Interactive effects of large- and small-scale sources of feral honey-bees for sunflower in the Argentine Pampas.

PubMed

Sáez, Agustín; Sabatino, Malena; Aizen, Marcelo A

2012-01-01

Pollinators for animal pollinated crops can be provided by natural and semi-natural habitats, ranging from large vegetation remnants to small areas of non-crop land in an otherwise highly modified landscape. It is unknown, however, how different small- and large-scale habitat patches interact as pollinator sources. In the intensively managed Argentine Pampas, we studied the additive and interactive effects of large expanses (up to 2200 ha) of natural habitat, represented by untilled isolated "sierras", and narrow (3-7 m wide) strips of semi-natural habitat, represented by field margins, as pollinator sources for sunflower (Helianthus annus). We estimated visitation rates by feral honey-bees, Apis mellifera, and native flower visitors (as a group) at 1, 5, 25, 50 and 100 m from a field margin in 17 sunflower fields 0-10 km distant from the nearest sierra. Honey-bees dominated the pollinator assemblage accounting for >90% of all visits to sunflower inflorescences. Honey-bee visitation was strongly affected by proximity to the sierras decreasing by about 70% in the most isolated fields. There was also a decline in honey-bee visitation with distance from the field margin, which was apparent with increasing field isolation, but undetected in fields nearby large expanses of natural habitat. The probability of observing a native visitor decreased with isolation from the sierras, but in other respects visitation by flower visitors other than honey-bees was mostly unaffected by the habitat factors assessed in this study. Overall, we found strong hierarchical and interactive effects between the study large and small-scale pollinator sources. These results emphasize the importance of preserving natural habitats and managing actively field verges in the absence of large remnants of natural habitat for improving pollinator services.

Child mental health in Sierra Leone: a survey and exploratory qualitative study.

PubMed

Yoder, Hélène N C; Tol, Wietse A; Reis, Ria; de Jong, Joop T V M

2016-01-01

This study complements the growing amount of research on the psychosocial impact of war on children in Sierra Leone by examining local perceptions of child mental health, formal and informal care systems, help-seeking behaviour and stigma. The study combined: (1) a nationwide survey of mental health care providers, with (2) exploratory qualitative research among service users and providers and other stakeholders concerned with child and adolescent mental health, with a particular emphasis on local explanations and stigma. Formal mental health care services are extremely limited resulting in an estimated treatment gap of over 99.8 %. Local explanations of child mental health problems in Sierra Leone are commonly spiritual or supernatural in nature, and associated with help-seeking from traditional healers or religious institutions. There is a considerable amount of stigma related to mental disorders, which affects children, their caregivers and service providers, and may lead to discrimination and abuse. Child and Adolescent Mental Health (CAMH) care development in Sierra Leone should cater to the long-term structural effects of war-violence and an Ebola epidemic. Priorities for development include: (1) the strengthening of legal structures and the development of relevant policies that strengthen the health system and specifically include children and adolescents, (2) a clearer local distinction between children with psychiatric, neurological, developmental or psychosocial problems and subsequent channelling into appropriate services (3) supplementary CAMH training for a range of professionals working with children across various sectors, (4) specialist training in CAMH, (5) integration of CAMH care into primary health care, education and the social welfare system, (6) further research on local explanations of child mental disorders and the effect they have on the well-being of the child, and (7) a careful consideration of the role of religious healers as care providers.

Population education in Sierra Leone.

PubMed

Lucan, T A

1985-06-01

The 1977 Sierra Leone 3 year population education project had 5 objectives: 1) to develop a core of Sierra Leoneans qualified in population education, 2) to integrate population education concepts into the curriculum for secondary schools and teachers colleges, 3) to train teachers already engaged in trial teaching in pilot schools in the new integrated curricula to give support to their colleagues, 4) to integrate population education into the whole Sierra Leone educational system, and 5) to create an awareness of the implications of population growth on the socioeconomic development of the country. A 1977 seminar on the Social Studies and Population Education Program discussed population issues and economic and social development. The strategy recommended at the seminar was that both the minor and the major revision approaches be used in the integration of population education concepts into the existing curriculum of the National Program in Social Studies for the lower secondary level. A Spiral Curriculum was established in 1981 constructed of 6 topics: 1) man's origins, development, and characteristics; 2) man's environment; 3) man's culture; 4) population and resources; 5) communication in the service of man; and 6) global issues-achievement and problems. Both at in-service and at pre-servicetraining, the enquiry method of teaching was emphasized. By the end of December 1981, the curriculum in Social Studies integrated with Population Education was completed for secondary schools and secondary teachers' colleges. The availability of the textbooks that secondary school students will take to their homes for their parents to read will contribute immensely to the attainment of the development objective of creating an awareness of the implications and consequences of population growth on the socioeconomic development of the country.

Medical Officers in Sierra Leone: Surgical Training Opportunities, Challenges and Aspirations.

PubMed

Wilks, Lucy; Leather, Andrew; George, Peter Matthew; Kamara, Thaim Bay

2018-02-05

The critical shortage of human resources for healthcare falls most heavily on sub-Saharan nations such as Sierra Leone, where such workforce deficits have grave impacts on its burden of surgical disease. An important aspect in retention and development of the workforce is training. This study focuses on postgraduate surgical training (formal and short course) and perceptions of opportunities, challenges and aspirations, in a country where more than half of surgical procedures are performed by medical officers. The study presents findings from 12 in-depth semi-structured interviews conducted with medical officers by the primary investigator in Sierra Leone between April and June 2017. Each interview was transcribed alongside an introspective reflexive journal to acknowledge and account for researcher biases. Two interviewees had accessed postgraduate surgical training and 10 (83%) had accessed short course surgically relevant training. The number of short courses accessed grew higher the more recently the medical officers had graduated. Supervision, short length and international standards were the most appreciated aspects of short training courses. Some medical officers perceived the formal postgraduate surgical training programme to be ill-equipped, doubting its credibility. This demotivated some from applying. Training is an essential aspect of developing an adequate surgical workforce. Faith must be restored in the capabilities of Sierra Leone's Ministry of Health and Sanitation to provide adequate and sustainable training. This study advocates for the use of short courses to restore this faith and the expansion of postgraduate surgical training to the districts through developing a regional teaching complex to provide short courses and eventually formal postgraduate training in the future. Copyright © 2018 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Population policy in the United States.

PubMed

Corsa, L

1979-01-01

The importance of population in the richer nations is seen in terms of increasing demand for fuels and the resultant pollution of air and water. All governments have a population policy, even if it negative and even if it is impied. U.S. federal funding for family planning, lack of funding for abortion, and immigration laws make up part of the U.S. population policy, an inconsistent policy. The 1970-72 Commission of Population Growth and the American Future called for stabilized growth, i.e. zero population growth. This is also the position of the Sierra Club and other organizations. So far, American presidents have not stated their position on the issue. In order to formulate a national population policy, the values must be recognized which a policy would affect. All national agovernments should provide widespread population education activities, provide easily available and safe family planning services, and incorporate demographic data into their planning. Population policy must be comprehensive and longterm. In the case of the U.S., it msut carry over from 1 administration to the next. The U.S. government has lagged behind in formulation of population policy. Private sector groups, e.g., the Sierra Club, must now take the lead.

Color and 3D views of the Sierra Nevada mountains

NASA Technical Reports Server (NTRS)

2002-01-01

A stereo 'anaglyph' created using the nadir and 45.6-degree forward-viewing cameras provides a three-dimensional view of the scene when viewed with red/blue glasses. The red filter should be placed over your left eye. To facilitate the stereo viewing, the images have been oriented with north toward the left. Some prominent features are Mono Lake, in the center of the image; Walker Lake, to its left; and Lake Tahoe, near the lower left. This view of the Sierra Nevadas includes Yosemite, Kings Canyon, and Sequoia National Parks. Mount Whitney, the highest peak in the contiguous 48 states (elev. 14,495 feet), is visible near the righthand edge. Above it (to the east), the Owens Valley shows up prominently between the Sierra Nevada and Inyo ranges. Precipitation falling as rain or snow on the Sierras feeds numerous rivers flowing southwestward into the San Joaquin Valley. The abundant fields of this productive agricultural area can be seen along the lower right; a large number of reservoirs that supply water for crop irrigation are apparent in the western foothills of the Sierras. Urban areas in the valley appear as gray patches; among the California cities that are visible are Fresno, Merced, and Modesto.

MMI attenuation and historical earthquakes in the basin and range province of western North America

USGS Publications Warehouse

Bakun, W.H.

2006-01-01

Earthquakes in central Nevada (1932-1959) were used to develop a modified Mercalli intensity (MMI) attenuation model for estimating moment magnitude M for earthquakes in the Basin and Range province of interior western North America. M is 7.4-7.5 for the 26 March 1872 Owens Valley, California, earthquake, in agreement with Beanland and Clark's (1994) M 7.6 that was estimated from geologic field observations. M is 7.5 for the 3 May 1887 Sonora, Mexico, earthquake, in agreement with Natali and Sbar's (1982) M 7.4 and Suter's (2006) M 7.5, both estimated from geologic field observations. MMI at sites in California for earthquakes in the Nevada Basin and Range apparently are not much affected by the Sierra Nevada except at sites near the Sierra Nevada where MMI is reduced. This reduction in MMI is consistent with a shadow zone produced by the root of the Sierra Nevada. In contrast, MMI assignments for earthquakes located in the eastern Sierra Nevada near the west margin of the Basin and Range are greater than predicted at sites in California. These higher MMI values may result from critical reflections due to layering near the base of the Sierra Nevada.

Paleozoic-Mesozoic boundary in the Berry Creek Quadrangle, northwestern Sierra Nevada, California

USGS Publications Warehouse

Hietanen, Anna Martta

1977-01-01

Structural and petrologic studies in the Berry Creek quadrangle at the north end of the western metamorphic belt of the Sierra Nevada have yielded new information that helps in distinguishing between the chemically similar Paleozoic and Mesozoic rocks. The distinguishing features are structural and textural and result from different degrees of deformation. Most Paleozoic rocks are strongly deformed and thoroughly recrystallized. Phenocrysts in meta volcanic rocks are granulated and drawn out into lenses that have sutured outlines. In contrast, the phenocrysts in the Mesozoic metavolcanic rocks show well-preserved straight crystal faces, are only slightly or not at all granulated, and contain fewer mineral inclusions than do those in the Paleozoic rocks. The groundmass in the Paleozoic rocks is recrystallized to a fairly coarse grained albite-epidote-amphibole-chlorite rock, whereas in the Mesozoic rocks the groundmass is a very fine grained feltlike mesh with only spotty occurrence of well-recrystallized finegrained albite-epidote-chlorite-actinolite rock. Primary minerals, such as augite, are locally preserved in the Mesozoic rocks but are altered to a mixture of amphibole, chlorite, and epidote in the Paleozoic rocks. In the contact aureoles of the plutons, and within the Big Bend fault zone, which crosses the area parallel to the structural trends, all rocks are thoroughly recrystallized and strongly deformed. Identification of the Paleozoic and Mesozoic rocks in these parts of the area was based on the continuity of the rock units in the field and on gradual changes in microscopic textures toward the plutons.

An integrative approach to phylogeography: investigating the effects of ancient seaways, climate, and historical geology on multi-locus phylogeographic boundaries of the Arboreal Salamander (Aneides lugubris).

PubMed

Reilly, Sean B; Corl, Ammon; Wake, David B

2015-11-04

Phylogeography is an important tool that can be used to reveal cryptic biodiversity and to better understand the processes that promote lineage diversification. We studied the phylogeographic history of the Arboreal Salamander (Aneides lugubris), a wide-ranging species endemic to the California floristic province. We used multi-locus data to reconstruct the evolutionary history of A. lugubris and to discover the geographic location of major genetic breaks within the species. We also used species distribution modeling and comparative phylogeography to better understand the environmental factors that have shaped the genetic history of A. lugubris. We found six major mitochondrial clades in A. lugubris. Nuclear loci supported the existence of at least three genetically distinct groups, corresponding to populations north of the San Francisco Bay and in the Sierra Nevada, in the Santa Cruz Mountains, and in the central coast and southern California. All of the genetic breaks in mitochondrial and nuclear loci corresponded to regions where historical barriers to dispersal have been observed in other species. Geologic or water barriers likely were the most important factors restricting gene flow among clades. Climatic unsuitability during glacial maximum may have contributed to the isolation of the mitochondrial clades in the central coast and southern California. A projection of our species distribution model to a future scenario with a moderate amount of climate change suggests that most of the range of A. lugubris will remain climatically suitable, but climatic conditions in the Sierra Nevada and low elevation areas in Southern California are likely to deteriorate. Aneides lugubris contains substantial cryptic genetic diversity as a result of historical isolation of populations. At least two (and perhaps three) evolutionarily significant units in A. lugubris merit protection; all six mitochondrial clades should be considered as management units within the species.

Pre-mesozoic palinspastic reconstruction of the eastern great basin (Western United States).

PubMed

Levy, M; Christie-Blick, N

1989-09-29

The Great Basin of the western United States has proven important for studies of Proterozoic and Paleozoic geology [2500 to 245 million years ago (Ma)] and has been central to the development of ideas about the mechanics of crustal shortening and extension. An understanding of the deformational history of this region during Mesozoic and Cenozoic time (245 Ma to the present) is required for palinspastic reconstruction of now isolated exposures of older geology in order to place these in an appropriate regional geographic context. Considerable advances in unraveling both the crustal shortening that took place during Mesozoic to early Cenozoic time (especially from about 150 to 50 Ma) and the extension of the past 37 million years have shown that earlier reconstructions need to be revised significantly. A new reconstruction is developed for rocks of middle Proterozoic to Early Cambrian age based on evidence that total shortening by generally east-vergent thrusts and folds was at least 104 to 135 kilometers and that the Great Basin as a whole accommodated approximately 250 kilometers of extension in the direction 287 degrees +/- 12 degrees between the Colorado Plateau and the Sierra Nevada. Extension is assumed to be equivalent at all latitudes because available paleomagnetic evidence suggests that the Sierra Nevada experienced little or no rotation with respect to the extension direction since the late Mesozoic. An estimate of the uncertainty in the amount of extension obtained from geological and paleomagnetic uncertainties increases northward from +/-56 kilometers at 36 degrees 30N to (-87)(+108) kilometers at 40 degrees N. On the basis of the reconstruction, the original width of the preserved part of the late Proterozoic and Early Cambrian basin was about 150 to 300 kilometers, about 60 percent of the present width, and the basin was oriented slightly more north-south with respect to present-day coordinates.

Acting Administrator Lightfoot Visits Sierra Nevada Corporation

NASA Image and Video Library

2017-04-06

Acting NASA Administrator Robert Lightfoot is seen as he flies the Dream Chaser Space System simulator, Thursday, April 6, 2017 during a visit to Sierra Nevada Corporation in Louisville, Colo. Photo Credit: (NASA/Joel Kowsky)

Running Parallel Discrete Event Simulators on Sierra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnes, P. D.; Jefferson, D. R.

2015-12-03

In this proposal we consider porting the ROSS/Charm++ simulator and the discrete event models that run under its control so that they run on the Sierra architecture and make efficient use of the Volta GPUs.

Mediterranean California, Chapter 13

Treesearch

M.E. Fenn; E.B. Allen; L.H. Geiser

2011-01-01

The Mediterranean California ecoregion (CEC 1997; Fig 2.2) encompasses the greater Central Valley, Sierra foothills, and central coast ranges of California south to Mexico and is bounded by the Pacific Ocean, Sierra Nevada Mountains and Mojave Desert.

Initiatives for Sustainable Community Development in Sierra Leone.

ERIC Educational Resources Information Center

Kamara, John M.; Kargbo, Stephen B.

1999-01-01

In Sierra Leone, two church-sponsored programs are focused on sustainable development. The Wesleyan Development Education and Awareness Programme trains people to initiate community projects. Women's Loan Scheme encourages development of small-scale enterprises. (SK)

Large-scale recovery of an endangered amphibian despite ongoing exposure to multiple stressors

USGS Publications Warehouse

Knapp, Roland A.; Fellers, Gary M.; Kleeman, Patrick M.; Miller, David A. W.; Vrendenburg, Vance T.; Rosenblum, Erica Bree; Briggs, Cheryl J.

2016-01-01

Amphibians are one of the most threatened animal groups, with 32% of species at risk for extinction. Given this imperiled status, is the disappearance of a large fraction of the Earth’s amphibians inevitable, or are some declining species more resilient than is generally assumed? We address this question in a species that is emblematic of many declining amphibians, the endangered Sierra Nevada yellow-legged frog (Rana sierrae). Based on >7,000 frog surveys conducted across Yosemite National Park over a 20-y period, we show that, after decades of decline and despite ongoing exposure to multiple stressors, including introduced fish, the recently emerged disease chytridiomycosis, and pesticides, R. sierrae abundance increased sevenfold during the study and at a rate of 11% per year. These increases occurred in hundreds of populations throughout Yosemite, providing a rare example of amphibian recovery at an ecologically relevant spatial scale. Results from a laboratory experiment indicate that these increases may be in part because of reduced frog susceptibility to chytridiomycosis. The disappearance of nonnative fish from numerous water bodies after cessation of stocking also contributed to the recovery. The large-scale increases in R. sierrae abundance that we document suggest that, when habitats are relatively intact and stressors are reduced in their importance by active management or species’ adaptive responses, declines of some amphibians may be partially reversible, at least at a regional scale. Other studies conducted over similarly large temporal and spatial scales are critically needed to provide insight and generality about the reversibility of amphibian declines at a global scale.

Large-scale recovery of an endangered amphibian despite ongoing exposure to multiple stressors.

PubMed

Knapp, Roland A; Fellers, Gary M; Kleeman, Patrick M; Miller, David A W; Vredenburg, Vance T; Rosenblum, Erica Bree; Briggs, Cheryl J

2016-10-18

Amphibians are one of the most threatened animal groups, with 32% of species at risk for extinction. Given this imperiled status, is the disappearance of a large fraction of the Earth's amphibians inevitable, or are some declining species more resilient than is generally assumed? We address this question in a species that is emblematic of many declining amphibians, the endangered Sierra Nevada yellow-legged frog (Rana sierrae). Based on >7,000 frog surveys conducted across Yosemite National Park over a 20-y period, we show that, after decades of decline and despite ongoing exposure to multiple stressors, including introduced fish, the recently emerged disease chytridiomycosis, and pesticides, R. sierrae abundance increased sevenfold during the study and at a rate of 11% per year. These increases occurred in hundreds of populations throughout Yosemite, providing a rare example of amphibian recovery at an ecologically relevant spatial scale. Results from a laboratory experiment indicate that these increases may be in part because of reduced frog susceptibility to chytridiomycosis. The disappearance of nonnative fish from numerous water bodies after cessation of stocking also contributed to the recovery. The large-scale increases in R. sierrae abundance that we document suggest that, when habitats are relatively intact and stressors are reduced in their importance by active management or species' adaptive responses, declines of some amphibians may be partially reversible, at least at a regional scale. Other studies conducted over similarly large temporal and spatial scales are critically needed to provide insight and generality about the reversibility of amphibian declines at a global scale.

Large-scale recovery of an endangered amphibian despite ongoing exposure to multiple stressors

PubMed Central

Knapp, Roland A.; Fellers, Gary M.; Kleeman, Patrick M.; Miller, David A. W.; Rosenblum, Erica Bree; Briggs, Cheryl J.

2016-01-01

Amphibians are one of the most threatened animal groups, with 32% of species at risk for extinction. Given this imperiled status, is the disappearance of a large fraction of the Earth’s amphibians inevitable, or are some declining species more resilient than is generally assumed? We address this question in a species that is emblematic of many declining amphibians, the endangered Sierra Nevada yellow-legged frog (Rana sierrae). Based on >7,000 frog surveys conducted across Yosemite National Park over a 20-y period, we show that, after decades of decline and despite ongoing exposure to multiple stressors, including introduced fish, the recently emerged disease chytridiomycosis, and pesticides, R. sierrae abundance increased sevenfold during the study and at a rate of 11% per year. These increases occurred in hundreds of populations throughout Yosemite, providing a rare example of amphibian recovery at an ecologically relevant spatial scale. Results from a laboratory experiment indicate that these increases may be in part because of reduced frog susceptibility to chytridiomycosis. The disappearance of nonnative fish from numerous water bodies after cessation of stocking also contributed to the recovery. The large-scale increases in R. sierrae abundance that we document suggest that, when habitats are relatively intact and stressors are reduced in their importance by active management or species’ adaptive responses, declines of some amphibians may be partially reversible, at least at a regional scale. Other studies conducted over similarly large temporal and spatial scales are critically needed to provide insight and generality about the reversibility of amphibian declines at a global scale. PMID:27698128

Past and future demographic dynamics of alpine species: limited genetic consequences despite dramatic range contraction in a plant from the Spanish Sierra Nevada.

PubMed

Blanco-Pastor, J L; Fernández-Mazuecos, M; Vargas, P

2013-08-01

Anthropogenic global climate change is expected to cause severe range contractions among alpine plants. Alpine areas in the Mediterranean region are of special concern because of the high abundance of endemic species with narrow ranges. This study combined species distribution models, population structure analyses and Bayesian skyline plots to trace the past and future distribution and diversity of Linaria glacialis, an endangered narrow endemic species that inhabits summits of Sierra Nevada (Spain). The results showed that: (i) the habitat of this alpine-Mediterranean species in Sierra Nevada suffered little changes during glacial and interglacial stages of late Quaternary; (ii) climatic oscillations in the last millennium (Medieval Warm Period and Little Ice Age) moderately affected the demographic trends of L. glacialis; (iii) future warming conditions will cause severe range contractions; and (iv) genetic diversity will not diminish at the same pace as the distribution range. As a consequence of the low population structure of this species, genetic impoverishment in the alpine zones of Sierra Nevada should be limited during range contraction. We conclude that maintenance of large effective population sizes via high mutation rates and high levels of gene flow may promote the resilience of alpine plant species when confronted with global warming. © 2013 John Wiley & Sons Ltd.

Paleozoic subduction complex and Paleozoic-Mesozoic island-arc volcano-plutonic assemblages in the northern Sierra terrane

USGS Publications Warehouse

Hanson, Richard E.; Girty, Gary H.; Harwood, David S.; Schweickert, Richard A.

2000-01-01

This field trip provides an overview of the stratigraphic and structural evolution of the northern Sierra terrane, which forms a significant part of the wall rocks on the western side of the later Mesozoic Sierra Nevada batholith in California. The terrane consists of a pre-Late Devonian subduction complex (Shoo Fly Complex) overlain by submarine arc-related deposits that record the evolution of three separate island-arc systems in the Late Sevonian-Early Mississippian, Permian, and Late Triassic-Jurassic. The two Paleozoic are packages and the underlying Shoo Fly Complex have an important bearing on plate-tectonic processes affecting the convergent margin outboard of the Paleozoic Cordilleran miogeocline, although their original paleogeographic relations to North America are controversial. The third arc package represents an overlap assemblage that ties the terrane to North America by the Late Triassic and helps constrain the nature and timing of Mesozoic orogenesis. Several of the field-trip stops examine the record of pre-Late Devonian subduction contained in the Shoo Fly Complex, as well as the paleovolcanology of the overlying Devonian to Jurassic arc rocks. Excellent glaciated exposures provide the opportunity to study a cross section through a tilted Devonian volcano-plutonic association. Additional stops focus on plutonic rocks emplaced during the Middle Jurassic arc magmatism in the terrane, and during the main pulse of Cretaceous magmatism in the Sierra Nevada batholith to the east.

Rietveld analysis of X-ray powder diffraction patterns as a potential tool for the identification of impact-deformed carbonate rocks

NASA Astrophysics Data System (ADS)

Huson, S. A.; Foit, F. F.; Watkinson, A. J.; Pope, M. C.

2009-12-01

Previous X-ray powder diffraction (XRD) studies revealed that shock deformed carbonates and quartz have broader XRD patterns than those of unshocked samples. Entire XRD patterns, single peak profiles and Rietveld refined parameters of carbonate samples from the Sierra Madera impact crater, west Texas, unshocked equivalent samples from 95 miles north of the crater and the Mission Canyon Formation of southwest Montana and western Wyoming were used to evaluate the use of X-ray powder diffraction as a potential tool for distinguishing impact deformed rocks from unshocked and tectonically deformed rocks. At Sierra Madera dolostone and limestone samples were collected from the crater rim (lower shock intensity) and the central uplift (higher shock intensity). Unshocked equivalent dolostone samples were collected from well cores drilled outside of the impact crater. Carbonate rocks of the Mission Canyon Formation were sampled along a transect across the tectonic front of the Sevier and Laramide orogenic belts. Whereas calcite subjected to significant shock intensities at the Sierra Madera impact crater can be differentiated from tectonically deformed calcite from the Mission Canyon Formation using Rietveld refined peak profiles, weakly shocked calcite from the crater rim appears to be indistinguishable from the tectonically deformed calcite. In contrast, Rietveld analysis readily distinguishes shocked Sierra Madera dolomite from unshocked equivalent dolostone samples from outside the crater and tectonically deformed Mission Canyon Formation dolomite.

Chemical and biological survey of lakes and streams located in the Emerald Lake watershed, Sequoia National Park. Final report, July 1984-July 1986

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melack, J.M.; Cooper, S.D.; Holmes, R.W.

1987-02-18

To investigate the effects or potential effects of acidification on Sierran aquatic habitats, the authors are conducting research on Emerald Lake and its inlet and outlet streams, in Sequoia National Park, California. Emerald Lake was chosen as the focus of the authors studies because it is representative of subalpine and alpine waters in the Sierra Nevada, and is located in the southwestern Sierra where acidic inputs are likely to be greater than in other areas of the Sierra Nevada. The investigations consist of two approaches: (1) A chemical and biological monitoring program and sediment analyses to provide the time seriesmore » needed to distinguish the effects of anthropogenic disturbance from natural variation; and (2) experimental investigations to examine the sensitivity of aquatic communities to acidic inputs and to predict the responses of aquatic communities to increased acidification. The research reported here began in June 1984 and continued through July 1986.« less

Late Quaternary offset of alluvial fan surfaces along the Central Sierra Madre Fault, southern California

USGS Publications Warehouse

Burgette, Reed J.; Hanson, Austin; Scharer, Katherine M.; Midttun, Nikolas

2016-01-01

The Sierra Madre Fault is a reverse fault system along the southern flank of the San Gabriel Mountains near Los Angeles, California. This study focuses on the Central Sierra Madre Fault (CSMF) in an effort to provide numeric dating on surfaces with ages previously estimated from soil development alone. We have refined previous geomorphic mapping conducted in the western portion of the CSMF near Pasadena, CA, with the aid of new lidar data. This progress report focuses on our geochronology strategy employed in collecting samples and interpreting data to determine a robust suite of terrace surface ages. Sample sites for terrestrial cosmogenic nuclide and luminescence dating techniques were selected to be redundant and to be validated through relative geomorphic relationships between inset terrace levels. Additional sample sites were selected to evaluate the post-abandonment histories of terrace surfaces. We will combine lidar-derived displacement data with surface ages to estimate slip rates for the CSMF.

Chronology for fluctuations in late Pleistocene Sierra Nevada glaciers and lakes

USGS Publications Warehouse

Phillips, F.M.; Zreda, M.G.; Benson, L.V.; Plummer, M.A.; Elmore, D.; Sharma, Prakash

1996-01-01

Mountain glaciers, because of their small size, are usually close to equilibrium with the local climate and thus should provide a test of whether temperature oscillations in Greenland late in the last glacial period are part of global-scale climate variability or are restricted to the North Atlantic region. Correlation of cosmogenic chlorine-36 dates on Sierra Nevada moraines with a continuous radiocarbon-dated sediment record from nearby Owens Lake shows that Sierra Nevada glacial advances were associated with Heinrich events 5, 3, 2, and 1.

Wall Rock Assimilation and Magma Migration in the Sierra Nevada Batholith: A Study of the Courtright Intrusive Zone, Central California

NASA Astrophysics Data System (ADS)

Torrez, G.; Putirka, K. D.

2010-12-01

The Sierra Nevada Batholith is composed of various plutons that interact with each other, and with pre- and syn-batholith metamorphic rocks. In the central part of the Sierra Nevada Batholith, at Courtright Reservoir in California, the younger Mt. Givens Pluton (87-93 Ma; McNulty et al., 2000) intrudes the Dinkey pluton (103 Ma; Bateman et al., 1964), and metasediments (a metamorphic screen) that, in places, separate the two plutons. This Courtright Reservoir Intrusive zone, as termed by Bateman et al. (1964), provides an ideal setting to examine the dynamics of intrusion and assimilation. Whole rock major and trace element compositions of the plutons, their mafic enclaves, and the metasediments, show that all such samples, from both plutons, fall on a single mixing trend. We thus infer that magmas parental to both plutons were roughly similar in composition, and assimilated significant amounts of the same, or very similar metasedimentary wall rocks. We also examined changes in whole rock compositions within the Mt. Givens pluton, as a function of distance from the two rock units with which it is now in contact (the metasediments, and the Dinkey Creek). In the vicinity of the contact between are an abundance of enclaves that are rounded, and appear to have been transported in vertical pipes. Whole rock analysis of the host granitoid material that surrounds these enclaves is clearly more mafic than the granitoid magmas from interior parts of the pluton. These whole rock compositions indicate that the pluton becomes more homogenous moving away from the contact, with a compositional decay occurring over a span of about 50-100 m. There are at least two possible interpretations. The compositional decay may represent a diffusive exchange of mass between an early crystallizing marginal phase of the pluton and the pluton interior. Another (not mutually incompatible) possibility is that the mafic margins represent pipes or tubes (Paterson, 2010), related to some convective instability at the margins of the pluton.

Combined 40Ar/39Ar and Fission-Track study of the Freetown Layered Igneous Complex, Freetown, Sierra Leone, West Africa: Implications for the Initial Break-up of Pangea to form the Central Atlantic Ocean and Insight into the Post-rift Evolution of the Sie

NASA Astrophysics Data System (ADS)

Barrie, Ibrahim; Wijbrans, Jan; Andriessen, Paul; Beunk, Frank; Strasser-King, Victor; Fode, Daniel

2010-05-01

Sierra Leone lies within the south-western part of the West African Craton and comprises two major Archaean structural divisions: a low-grade granite-greenstone terrane characterised by N-S striking structures and a NW-SE striking highly metamorphosed belt of strained rocks that form the coastal margin of the craton. Intruded into the belt is the Freetown Layered Igneous Complex (FLIC), a tholeiitic magamtic body emplaced prior to or during the break-up of Pangea to form the Central Atlantic Ocean and, forming today the high ground of the coastal outline of Sierra Leone which is one of the most distinctive features on the West African coast. The break-up of Pangaea to form the Central Atlantic and its passive margins began in the Early Jurassic. Geo-tectonically, the break-up was particularly characterised by the formation of the Central Atlantic Magmatic Province (CAMP), covering once-contiguous parts of North America, Europe, Africa and South America. The FLIC forming part of the heart of CAMP is the largest single layered igneous intrusive yet known on either side of the Central Atlantic, measuring on surface, 65 x 14 x 7 km. Geophysical investigations indicate that the intrusion extends offshore to a depth of about 20 km. Geologically the Complex is a rhythmically layered elongated ultramafic-mafic lopolith divisible into 4 major zones each comprising repeated sequences of troctolitic, gabbroic and anorthositic rocks. An idealised unit of layering is from base upwards: dunite, troctolite, olivine-gabbro, leuco-gabbro, gabbro-norite and anorthosite cumulates. 40Ar-39Ar age spectra and 40Ar/36Ar versus 39Ar/36Ar isochron plots obtained by stepwise-heating experiments on plagioclases, biotites and amphiboles from troctolites, olivine-gabbros, gabbro-norites and anorthosites of the four zones yield plateau and isochron ages that seem to depict the cooling history of the Complex after emplacement. The biotites and some of the plagioclases and amphiboles give very good plateaus that range from 196.3 ± 3 Ma to 232.1 ± 9 Ma with the best-fit isochron plots showing a range from 193.3± 10 Ma to 234.1 ± 11 Ma. Because these dates represent cooling ages, we interpret them as representing a minimum intrusion-age of the Complex implying that its true emplacement age might be somewhat older than 230 Ma. Given that most established CAMP ages revolve around 200 Ma or younger, we hypothesise that FLIC represents a hitherto unknown pre-CAMP magmatic event that might have thermally triggered the initial break-up of Pangaea to form the Central Atlantic. This view is consistent with field-observations that the Complex is cross-cut by predominantly coast-parallel mafic dykes attributed to the CAMP dyke-swarm. To ascertain the hypothesis, we are currently carrying out U-Pb zircon dating to establish, precisely, the true emplacement age of the Complex. The Fission-track ages vary from 91.7 ± 7 Ma to 114.6 ± 9 Ma. This age range shows that after emplacement and crystallisation, the FLIC underwent an extremely slow cooling for a long period of time. This in turn implies that after the break-up of Pangea to form, in part, the Sierra Leone margin, a late and slow uplift (Erosion/denudation) that took place during the Cretaceous was a very important geological process that characterised the post-rift evolution of the margin. References: Barrie, I.J., P.A.M. Andriessen, F.F. Beunk, J.R. Wijbrans, V.E.H. Strasser-King, D.V.A.Fode. (2006). Tectonothermal Evolution of the Sierra Leone Passive Continental Margin, West Africa: Constraints from Thermochronology. Geochemica et Cosmochemica Acta 70 (18): A36- A36 Suppl. S Aug-Sep 2006. Marzoli, A., P.R. Renne, E.M. Piccirillo, M. Ernesto, G. Bellieni, A De Min. (1999). Extensive 200-Million-Year-Old Continental Flood Basalts of the Central Atlantic Magmatic Province. Science284: 616-618. McHone, J.G. (2000). Non-plume magmatism and rifting during the opening of the central Atlantic Ocean. Tectonophysics, 316: 287-296. Umeji, A.C. (1983). Geochemistry and Mineralogy of the Freetown Layered Basic Igneous Complex of Sierra Leone. Chemical Geology, 39: 17-38. Wells, M.K. (1962). Structure and Petrology of the Freetown Layered Basic Complex of Sierra Leone. Overseas Geol. Mineral. Res. Bull. Suppl., 4, 115 pp. Williams, H.R. (1986). The Archaean Kaila Group of Western Sierra Leone: Geology and Relations with adjacent Granite-Greenstone Terrane. Precambrian Research, 38: 201-213.

Late Pleistocene ages for the most recent volcanism and glacial-pluvial deposits at Big Pine volcanic field, California, USA, from cosmogenic 36Cl dating

USGS Publications Warehouse

Vazquez, Jorge A.; Woolford, Jeff M

2015-01-01

The Big Pine volcanic field is one of several Quaternary volcanic fields that poses a potential volcanic hazard along the tectonically active Owens Valley of east-central California, and whose lavas are interbedded with deposits from Pleistocene glaciations in the Sierra Nevada Range. Previous geochronology indicates an ∼1.2 Ma history of volcanism, but the eruption ages and distribution of volcanic products associated with the most-recent eruptions have been poorly resolved. To delimit the timing and products of the youngest volcanism, we combine field mapping and cosmogenic 36Cl dating of basaltic lava flows in the area where lavas with youthful morphology and well-preserved flow structures are concentrated. Field mapping and petrology reveal approximately 15 vents and 6 principal flow units with variable geochemical composition and mineralogy. Cosmogenic 36Cl exposure ages for lava flow units from the top, middle, and bottom of the volcanic stratigraphy indicate eruptions at ∼17, 27, and 40 ka, revealing several different and previously unrecognized episodes of late Pleistocene volcanism. Olivine to plagioclase-pyroxene phyric basalt erupted from several vents during the most recent episode of volcanism at ∼17 ka, and produced a lava flow field covering ∼35 km2. The late Pleistocene 36Cl exposure ages indicate that moraine and pluvial shoreline deposits that overlie or modify the youngest Big Pine lavas reflect Tioga stage glaciation in the Sierra Nevada and the shore of paleo-Owens Lake during the last glacial cycle.

KSC-2011-7887

NASA Image and Video Library

2011-11-22

CAPE CANAVERAL, Fla. -- Andy Aldrin, director of business development for United Launch Alliance (ULA), talks to media about plans to launch NASA astronauts to the International Space Station in the Atlas Spaceflight Operations Center (ASOC) at Cape Canaveral Air Force Station in Florida. ULA is working to make its Atlas V rocket safe for humans for NASA's Commercial Crew Program (CCP) under the Commercial Crew Development Round 2 (CCDev2) activities. Part of those plans will be to design and test an emergency detection system and crew access capabilities. ULA also is working with other aerospace system providers developing spacecraft that would launch atop the company's Atlas V rocket, such as Blue Origin, Sierra Nevada and The Boeing Co. CCP, which is based at the adjacent NASA's Kennedy Space Center, is partnering with industry to take crews to the station or other low Earth orbit destinations. Aldrin explained that the goal of ULA will be to develop a human spaceflight capability without altering rocket's proven design and successful track record. It's the freedom to develop innovative solutions such as this that CCP hopes will drive down the cost of space travel as well as open up space to more people than ever before. Seven aerospace companies are maturing launch vehicle and spacecraft designs under CCDev2, including Alliant Techsystems Inc. (ATK) of Promontory, Utah, Blue Origin of Kent, Wash., The Boeing Co., of Houston, Excalibur Almaz Inc. of Houston, Sierra Nevada Corp. of Louisville, Colo., Space Exploration Technologies (SpaceX) of Hawthorne, Calif., and United Launch Alliance (ULA) of Centennial, Colo. For more information, visit www.nasa.gov/exploration/commercial Photo credit: Jim Grossmann

Updated paleomagnetic pole from Cretaceous plutonic rocks of the Sierra Nevada, California: Tectonic displacement of the Sierra Nevada block

USGS Publications Warehouse

Hillhouse, John W.; Gromme, Sherman

2011-01-01

We report remanent magnetization measurements from 13 sites in Cretaceous plutonic rocks in the northern Sierra Nevada (38°N–39.5°N). By increasing the number of available paleomagnetic sites, the new data tighten constraints on the displacement history of the Sierra Nevada block and its pre-extensional position relative to interior North America. We collected samples in freshly exposed outcrops along four highway transects. The rocks include diorite, granodiorite, and tonalite with potassium-argon ages (hornblende) ranging from 100 Ma to 83 Ma. By combining our results with previous paleomagnetic determinations from the central and southern Sierra Nevada (excluding sites from the rotated southern tip east of the White Wolf–Kern Canyon fault system), we find a mean paleomagnetic pole of 70.5°N, 188.2°E, A95 = 2.6° (N = 26, Fisher concentration parameter, K = 118). Thermal demagnetization indicates that the characteristic remanence is generally unblocked in a narrow range within 35 °C of the Curie temperature of pure magnetite. Small apparent polar wander during the Cretaceous normal-polarity superchron, plus prolonged acquisition of remanence at the site level, may account for the low dispersion of virtual geomagnetic poles and relatively large K value. Tilt estimates based on overlapping sediments, stream gradients, and thermochronology of the Sierra Nevada plutons vary from 0° to 3° down to the southwest. Without tilt correction, the mean paleomagnetic pole for the Sierra Nevada is essentially coincident with the North American reference pole during the Cretaceous stillstand (125 Ma to 80 Ma). At 95% confidence, the apparent latitude shift is 1.1° ± 3.0° (positive northward), and the apparent rotation is negligible, 0.0° ± 4.7°. Correcting for each degree of tilt, which is limited to 3° on geologic evidence, increases the rotation anomaly 2.2° counterclockwise, while the apparent latitude shift remains unchanged.

48 CFR 52.225-23 - Required Use of American Iron, Steel, and Manufactured Goods-Buy American Act-Construction...

Code of Federal Regulations, 2010 CFR

2010-10-01

... Principe, Senegal, Sierra Leone, Solomon Islands, Somalia, Tanzania, Togo, Tuvalu, Uganda, Vanuatu, Yemen..., Rwanda, Samoa, Sao Tome and Principe, Senegal, Sierra Leone, Solomon Islands, Somalia, Tanzania, Togo...

48 CFR 52.225-23 - Required Use of American Iron, Steel, and Manufactured Goods-Buy American Act-Construction...

Code of Federal Regulations, 2011 CFR

2011-10-01

... Principe, Senegal, Sierra Leone, Solomon Islands, Somalia, Tanzania, Togo, Tuvalu, Uganda, Vanuatu, Yemen..., Rwanda, Samoa, Sao Tome and Principe, Senegal, Sierra Leone, Solomon Islands, Somalia, Tanzania, Togo...

KSC-2012-1014

NASA Image and Video Library

2010-11-21

BOULDER, Colo. – A Sierra Nevada Corp. team member examines the company's structural test article for the Dream Chaser spacecraft in the University of Colorado at Boulder’s Facility for Advanced Spatial Technology. The university is one of Sierra Nevada’s partners on the design and development of the Dream Chaser orbital crew vehicle. Dream Chaser is one of five systems NASA invested in during Commercial Crew Development Round 1 CCDev1 activities in order to aid in the innovation and development of American-led commercial capabilities for crew transportation and rescue services to and from the International Space Station and other low Earth orbit destinations. In 2011, NASA's Commercial Crew Program CCP entered into another funded Space Act Agreement with Sierra Nevada for the second round of commercial crew development CCDev2) so the company could further develop its Dream Chaser spacecraft for NASA transportation services. For information about CCP, visit www.nasa.gov/commercialcrew. Photo credit: Sierra Nevada Corp.

Dataset of Passerine bird communities in a Mediterranean high mountain (Sierra Nevada, Spain).

PubMed

Pérez-Luque, Antonio Jesús; Barea-Azcón, José Miguel; Álvarez-Ruiz, Lola; Bonet-García, Francisco Javier; Zamora, Regino

2016-01-01

In this data paper, a dataset of passerine bird communities is described in Sierra Nevada, a Mediterranean high mountain located in southern Spain. The dataset includes occurrence data from bird surveys conducted in four representative ecosystem types of Sierra Nevada from 2008 to 2015. For each visit, bird species numbers as well as distance to the transect line were recorded. A total of 27847 occurrence records were compiled with accompanying measurements on distance to the transect and animal counts. All records are of species in the order Passeriformes. Records of 16 different families and 44 genera were collected. Some of the taxa in the dataset are included in the European Red List. This dataset belongs to the Sierra Nevada Global-Change Observatory (OBSNEV), a long-term research project designed to compile socio-ecological information on the major ecosystem types in order to identify the impacts of global change in this area.

Dataset of Passerine bird communities in a Mediterranean high mountain (Sierra Nevada, Spain)

PubMed Central

Pérez-Luque, Antonio Jesús; Barea-Azcón, José Miguel; Álvarez-Ruiz, Lola; Bonet-García, Francisco Javier; Zamora, Regino

2016-01-01

Abstract In this data paper, a dataset of passerine bird communities is described in Sierra Nevada, a Mediterranean high mountain located in southern Spain. The dataset includes occurrence data from bird surveys conducted in four representative ecosystem types of Sierra Nevada from 2008 to 2015. For each visit, bird species numbers as well as distance to the transect line were recorded. A total of 27847 occurrence records were compiled with accompanying measurements on distance to the transect and animal counts. All records are of species in the order Passeriformes. Records of 16 different families and 44 genera were collected. Some of the taxa in the dataset are included in the European Red List. This dataset belongs to the Sierra Nevada Global-Change Observatory (OBSNEV), a long-term research project designed to compile socio-ecological information on the major ecosystem types in order to identify the impacts of global change in this area. PMID:26865820

KSC-2012-1012

NASA Image and Video Library

2012-01-12

CAPE CANAVERAL, Fla. -- This is a printable poster of the aerospace companies NASA's Commercial Crew Program (CCP) entered into Space Act Agreements with during Commercial Crew Development Round 2 (CCDev2) activities in 2011 in order to mature the design and development of crew transportation systems with the overall goal of accelerating a United States-led capability to the International Space Station. CCDev2 companies are Alliant Techsystems (ATK), Blue Origin, The Boeing Co., Excalibur Almaz Inc., Sierra Nevada Corp., Space Exploration Technologies (SpaceX), and United Launch Alliance (ULA). The goal of CCP is to drive down the cost of space travel as well as open up space to more people than ever before by balancing industry’s own innovative capabilities with NASA's 50 years of human spaceflight experience. For more information, visit www.nasa.gov/commercialcrew

KSC-2012-1009

NASA Image and Video Library

2012-01-12

CAPE CANAVERAL, Fla. -- This is a printable banner of the aerospace companies NASA's Commercial Crew Program (CCP) entered into Space Act Agreements with during Commercial Crew Development Round 2 (CCDev2) activities in 2011 in order to mature the design and development of crew transportation systems with the overall goal of accelerating a United States-led capability to the International Space Station. CCDev2 companies are Alliant Techsystems (ATK), Blue Origin, The Boeing Co., Excalibur Almaz Inc., Sierra Nevada Corp., Space Exploration Technologies (SpaceX), and United Launch Alliance (ULA). The goal of CCP is to drive down the cost of space travel as well as open up space to more people than ever before by balancing industry’s own innovative capabilities with NASA's 50 years of human spaceflight experience. For more information, visit www.nasa.gov/commercialcrew

Environmental exposures to agrochemicals in the Sierra Nevada mountain range

USGS Publications Warehouse

LeNoir, J.; Aston, L.; Data, S.; Fellers, G.; McConnell, L.; Sieber, J.

2000-01-01

The release of pesticides into the environment may impact human and environmental health. Despite the need for environmental exposure data, few studies quantify exposures in urban areas and even fewer determine exposures to wildlife in remote areas. Although it is expected that concentrations in remote regions will be low, recent studies suggest that even low concentrations may have deleterious effects on wildlife. Many pesticides are known to interfere with the endocrine systems of humans and wildlife, adversely affecting growth, development, and behavior. This chapter reviews the fate and transport of pesticides applied in the Central Valley of California and quantifies their subsequent deposition into the relatively pristine Sierra Nevada Mountain Range.

48 CFR 52.225-23 - Required Use of American Iron, Steel, and Manufactured Goods-Buy American Act-Construction...

Code of Federal Regulations, 2012 CFR

2012-10-01

..., Mozambique, Nepal, Niger, Rwanda, Samoa, Sao Tome and Principe, Senegal, Sierra Leone, Solomon Islands..., Mauritania, Mozambique, Nepal, Niger, Rwanda, Samoa, Sao Tome and Principe, Senegal, Sierra Leone, Solomon...

48 CFR 52.225-23 - Required Use of American Iron, Steel, and Manufactured Goods-Buy American Act-Construction...

Code of Federal Regulations, 2013 CFR

2013-10-01

..., Rwanda, Samoa, Sao Tome and Principe, Senegal, Sierra Leone, Solomon Islands, Somalia, South Sudan..., Mozambique, Nepal, Niger, Rwanda, Samoa, Sao Tome and Principe, Senegal, Sierra Leone, Solomon Islands...

76 FR 46209 - Importation of Tomatoes From the Economic Community of West African States Into the Continental...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-02

..., Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali, Niger, Nigeria, Senegal, Sierra Leone..., Liberia, Mali, Niger, Nigeria, Senegal, Sierra Leone, and Togo Republic. These conditions are designed to...

Examinations of Linkages Between the Northwest Mexican Monsoon and Great Plains Precipitation

NASA Astrophysics Data System (ADS)

Saleeby, S. M.; Cotton, W. R.

2001-12-01

The Regional Atmospheric Modeling System (RAMS) is being used to examine linkages between the Mexican monsoon and precipitation in the Great Plains region of the United States. Currently, available datasets have allowed for seasonal runs for July and August of the 1993 flood year in the midwest US and the 1997 El Nino year. There is also a plan to perform a full monsoon season simulation of the drought summer of 1988 once precipitation data becomes available. Preliminary results of this ongoing study are presented here. The model configuration consists of a 120km resolution coarse grid that covers a region from west of Hawaii to Bermuda and from south of the equator up into Canada. Two 40km resolution nested grids exist, with one covering the western two-thirds of the United States and Mexico and the other covering the Pacific ITCZ. A 10km fine grid and 2.5km cloud resolving grid are spawned over the region of monsoon surges to explicitly resolve convection. The model is initialized with NCEP reanalysis data, surface obs, rawinsonde data, variable soil moisture, and weekly averaged SST's. RAMS is running with two-stream Harrington radiation, one moment microphysics, and Kuo cumulus parameterization. The completed 1993 and 1997 seasonal simulations are now being examined and verified again NCEP reanalysis data and high resolution precipitation data. Initial model results look promising when verified against the NCEP upper level fields, such that the model is able to capture the large scale dynamics. For the duration of both seasonal runs, RAMS successfully simulates the mid and upper level geopotential heights, the temperature, and winds. The large scale 700mb and 500mb anti-cyclone over the US and Mexico is resolved, as well as the easterly flow over Mexico. Model fields are also being examined to isolate monsoon surge events which are characterized by increased precipitation over the Sierra Madres and a northward moisture surge into the northern extent of the Gulf of California and southern Arizona. Within the coarse grids, the RAMS model has successfully resolved the low-level jet that persists in the Gulf of California and the local maximum in mixing ratio that persists over the gulf. It has also captured the upslope flow over the Sierra Madres that forces the moist air into the higher elevation to the east. This provides the necessary lifting and moisture for the development of intense convection and resulting large amounts of precipitation that occur along the Sierra Madre mountain range. Examination of model-predicted low-level moisture transport reveals that moisture advected from the Gulf of California is the primary monsoon moisture source, rather than the Gulf of Mexico. Time averages of moisture transport, mixing ratio, winds, and precipitation for July 1993 reveal the prominent diurnal cycle variations that exist due to radiative effects and land-sea interactions; the maximum in convection, precipitation rate, and moisture transport occurs around 00Z. Seasonal accumulated precipitation amounts in the model are successful in predicting the placement of precipitation and relative amounts for most of the 40km continental grid, but there is an overestimation of precipitation along the northern Sierra Madre Occidental and an underestimation in the US mid-west. During the 1993 flood summer, much of the mid-west US precipitation fell in association with mesoscale convective systems; it is suspected that other cumulus parameterizations may provide better prediction of sub-grid scale convective precipitation. >http://hugo.atmos.colostate.edu/www/monsoon/monsoon.html

Timing and rates of long-term landscape evolution in Southern Argentina

NASA Astrophysics Data System (ADS)

Kollenz, S.; Glasmacher, P. A.

2013-12-01

The eastern Argentina South Atlantic passive continental margin is distinguished by a very flat topography. Out of the so called Pampean flat two mountain ranges are arising. These mountain ranges, the Sierras Australes and the Sierras Septentrionales, are located in the State of Buenos Aires south of the capital Buenos Aires. North of the Sierras Septentrionales the Salado basin is located. The Sierras Septentrionales and the Sierras Australes are also divided by a smaller intracratonic basin. Further in the South the Colorado basin is located. The Sierras Australes is a variscian fold belt originated by strong phases of metamorphosis, but till now it is unclear by how many tectonic phases the area was influenced (Tomezzoli & Vilas, 1999). It consists of Proterozoic to Paleozoic rocks. The Sierras Septentrionales consists mainly of Precambrian crystalline rocks. The Precambrian sequences are overlain by younger Sediments (Cingolani, 2010). The aim is to understand the long-term landscape evolution of the area by quantifiying erosion- and exhumation-rates and by dating ancient rock-uplift-events. Another goal is to find out how the opening of the south atlantic took effect on this region. To fulfill this goal, thermochronological techniques, such as fission-track dating and (U-Th-Sm)/He dating has been applied to samples from the region. Because there was no low- temperature thermochronology done in this area, both techniques were applied on apatites and zircons. Furthermore, numerical modeling of the cooling history has provided the data base for the quantification of the exhumation rates. The data-set shows clusters of different ages which can be linked to tectonic activities during late Paleozoic times. Also the thermokinematic modeling is leading to new insights of the evolution of both mountain ranges and shows patterns of ongoing tectonic processes in this region. Caltculated exhumation rates show also varying cooling historys and the influence of tectonics throughout the research area. References: Renata Nela Tomezzoli and Juan Francisco Vilas (1999): Palaeomagnetic constraints on the age of deformation of the Sierras Australes thrust and fold belt, Argentina. Geophys. J. Int. (1999) 138, 857-870 Carlos A. Cingolani (2010): The Tandilia System of Argentina as a southern extension of the Rio de la Plata craton: an overview, Int. J. Earth. Sci. (Geol. Rundsch.) (2011) 100, 221-242

Age, geochemical composition, and distribution of Oligocene ignimbrites in the northern Sierra Nevada, California: Implications for landscape morphology, elevation, and drainage divide geography of the Nevadaplano

USGS Publications Warehouse

Cassel, Elizabeth J.; Calvert, Andrew T.; Graham, Stephan A.

2009-01-01

To gain a better understanding of the topographic and landscape evolution of the Cenozoic Sierra Nevada and Basin and Range, we combine geochemical and isotopic age correlations with palaeoaltimetry data from widely distributed ignimbrites in the northern Sierra Nevada, California. A sequence of Oligocene rhyolitic ignimbrites is preserved across the modern crest of the range and into the western foothills. Using trace and rare earth element geochemical analyses of volcanic glass, these deposits have been correlated to ignimbrites described and isotopically dated in the Walker Lane fault zone and in central Nevada (Henry et al., 2004, Geologic map of the Dogskin mountain quadrangle; Washoe County, Nevada; Faulds et al., 2005, Geology, v. 33, p. 505–508). Ignimbrite deposits were sampled within the northern Sierra Nevada and western Nevada, and four distinct geochemical compositions were identified. The majority of samples from within the northern Sierra Nevada have compositions similar to the tuffs of Axehandle Canyon or Rattlesnake Canyon, both likely sourced from the same caldera complex in either the Clan Alpine Mountains or the Stillwater Range, or to the tuff of Campbell Creek, sourced from the Desatoya Mountains caldera. New 40Ar/39Ar age determinations from these samples of 31.2, 30.9, and 28.7 Ma, respectively, support these correlations. Based on an Oligocene palinspastic reconstruction of the region, our results show that ignimbrites travelled over 200 km from their source calderas across what is now the crest of the Sierra Nevada, and that during that time, no drainage divide existed between the ignimbrite source calderas in central Nevada and sample locations 200 km to the west. Palaeoaltimetry data from Sierra Nevada ignimbrites, based on the hydrogen isotopic composition of hydration water in glass, reflect the effect of a steep western slope on precipitation and indicate that the area had elevations similar to the present-day range. These combined results suggest that source calderas were likely located in a region of high elevation to the east of the Oligocene Sierra Nevada, which had a steep western slope that allowed for the large extent and broad distribution of the ignimbrites.

Tectonics of the North American Cordillera near the Fortieth Parallel

USGS Publications Warehouse

King, P.B.

1978-01-01

The North American Cordillera near the Fortieth Parallel consists of the following tectonic units: 1. (A) To the east is a reactivated cratonic area, in the Southern Rocky Mountains and Colorado Plateau, in which the supracrustal rocks (Cambrian to Cretaceous) were broadly deformed during the late Cretaceous-Paleocene Laramide orogeny, and the Precambrian basement was raised in folds of wide amplitude. 2. (B) West of it is a miogeosynclinal belt, in the eastern Great Basin, in which a thick sequence of Paleozoic carbonates and related deposits was thrust eastward along low-angle faults during the middle to late Cretaceous Sevier orogeny. The miogeosyncline is the downwarped western margin of the original North American continent, and its rocks accumulated on Precambrian basement. 3. (C) Beyond is a eugeosynclinal belt, in the western Great Basin, in which Paleozoic graywackes, cherts, and volcanics were thrust easteastward along low-angle faults during several Paleozoic orogenies - the mid-Paleozoic Antler orogeny which produced the Roberts thrust on the east, and the end-Paleozoic Sonoma orogeny which produced the Golconda thrust farther west. The Paleozoic eugeosynclinal rocks accumulated on oceanic basement. They are overlapped from the west by Triassic and Jurassic shelf deposits, which pass westward into eugeosynclinal deposits. 4. (D) A volcanic island-arc belt existed on the sites of the Sierra Nevada in Paleozoic and early Mesozoic time, which produced thick bodies of sediments and volcanics. During the mid-Mesozoic Nevadan orogeny these were steeply deformed and thrust westward over subduction zones, and were intruded by granitic rocks that rose from the upper mantle to form great batholiths. 5. (E) West of the Sierra Nevada, in the Great Valley, is a great sedimentary embankment of later Mesozoic flysch or turbidite, largely younger than the supracrustal rocks of the Sierra Nevada and the Nevadan orogeny. It was formed of the erosional products of the supracrustal and granitic rocks of the Sierra Nevada. 6. (F) This sequence is, in turn, thrust westward over the Mesozoic Franciscan terrane of the Coast Ranges, which forms the westernmost belt of the Cordillera, and which is being treated in other papers in this symposium. The net effect of the prolonged events that produced the Cordillera in this segment has been the addition of successive tectonic belts to the North American continent at the expense of the Pacific Ocean basin during Phanerozoic time. ?? 1978.

Habitat preferences of butterflies in the Bumbuna Forest, Northern Sierra Leone.

PubMed

Sundufu, Abu James; Dumbuya, Rashida

2008-01-01

The habitat preferences of the butterfly fauna were studied in the Bumbuna Forest Reserve in northern Sierra Leone. The intact forest reserve and a secondary forest regrowth, disturbed as a result of slash-and-burn agriculture, were compared to savanna habitats. Of the 290 specimens collected, 195 butterfly species were included, of which significant proportion were Nymphalidae. Of the 147 forest species, 111 (75.5%) showed preferences for the forest habitats, while 70 (47.6%) and 34 (23.1%) preferred disturbed and savannah habitats, respectively. Numerically, a comparable proportion of savannah species were recorded in the 18 disturbed (73.9%) and 16 savannah habitats (63.2%). Accumulated species richness and diversity indices were lower in the disturbed habitats compared to the forest reserve, but lowest in the savanna habitats. However, a large proportion of forest species, especially those with either a more restricted geographic range or species for which no information on geographic distribution was available, were exclusively captured in the forest patches. The survey indicated the presence of a rich butterfly fauna, which should be systematically collected for further research and study in order to build a good taxonomic database for Sierra Leone.

Water quality associated public health risk in Bo, Sierra Leone.

PubMed

Jimmy, David H; Sundufu, Abu J; Malanoski, Anthony P; Jacobsen, Kathryn H; Ansumana, Rashid; Leski, Tomasz A; Bangura, Umaru; Bockarie, Alfred S; Tejan, Edries; Lin, Baochuan; Stenger, David A

2013-01-01

Human health depends on reliable access to safe drinking water, but in many developing countries only a limited number of wells and boreholes are available. Many of these water resources are contaminated with biological or chemical pollutants. The goal of this study was to examine water access and quality in urban Bo, Sierra Leone. A health census and community mapping project in one neighborhood in Bo identified the 36 water sources used by the community. A water sample was taken from each water source and tested for a variety of microbiological and physicochemical substances. Only 38.9% of the water sources met World Health Organization (WHO) microbial safety requirements based on fecal coliform levels. Physiochemical analysis indicated that the majority (91.7%) of the water sources met the requirements set by the WHO. In combination, 25% of these water resources met safe drinking water criteria. No variables associated with wells were statistically significant predictors of contamination. This study indicated that fecal contamination is the greatest health risk associated with drinking water. There is a need to raise hygiene awareness and implement inexpensive methods to reduce fecal contamination and improve drinking water safety in Bo, Sierra Leone.

Habitat Preferences of Butterflies in the Bumbuna Forest, Northern Sierra Leone

PubMed Central

Sundufu, Abu James; Dumbuya, Rashida

2008-01-01

The habitat preferences of the butterfly fauna were studied in the Bumbuna Forest Reserve in northern Sierra Leone. The intact forest reserve and a secondary forest regrowth, disturbed as a result of slash-and-burn agriculture, were compared to savanna habitats. Of the 290 specimens collected, 195 butterfly species were included, of which significant proportion were Nymphalidae. Of the 147 forest species, 111 (75.5%) showed preferences for the forest habitats, while 70 (47.6%) and 34 (23.1%) preferred disturbed and savannah habitats, respectively. Numerically, a comparable proportion of savannah species were recorded in the 18 disturbed (73.9%) and 16 savannah habitats (63.2%). Accumulated species richness and diversity indices were lower in the disturbed habitats compared to the forest reserve, but lowest in the savanna habitats. However, a large proportion of forest species, especially those with either a more restricted geographic range or species for which no information on geographic distribution was available, were exclusively captured in the forest patches. The survey indicated the presence of a rich butterfly fauna, which should be systematically collected for further research and study in order to build a good taxonomic database for Sierra Leone. PMID:20302525

Horticulture of Ribes

USDA-ARS?s Scientific Manuscript database

The genus Ribes L., known as currants and gooseberries, contains more than 150 diverse species indigenous throughout the northern hemisphere and along the Rocky Mountain, Sierra Nevada, and Sierra Madres in North America through mountain ranges of Central America to the Andes in South America. Begin...

California; Northern Sierra Air Quality Management District; Approval of Air Plan Revisions; Wood Burning Devices

EPA Pesticide Factsheets

EPA is taking final action to approve a revision to the Northern Sierra Air Quality Management District (NSAQMD) portion of the California SIP concerning emissions of particulate matter (PM) from wood burning devices.

Sierra/Aria 4.48 Verification Manual.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sierra Thermal Fluid Development Team

Presented in this document is a portion of the tests that exist in the Sierra Thermal/Fluids verification test suite. Each of these tests is run nightly with the Sierra/TF code suite and the results of the test checked under mesh refinement against the correct analytic result. For each of the tests presented in this document the test setup, derivation of the analytic solution, and comparison of the code results to the analytic solution is provided. This document can be used to confirm that a given code capability is verified or referenced as a compilation of example problems.

Gravity and Magnetic Anomalies of the Sierra Madera, Texas, "Dome".

PubMed

Van Lopik, J R; Geyer, R A

1963-10-04

A geophysical traverse across the Sierra Madera "Dome" indicates a negative gravity anomaly of 1(1/2) milligals over the zone of brecciation in the center and a residual positive anomaly of (1/2) milligal associated with a positive magnetic anomaly of 25 x 10(-5) oersted to the southeast of the zone of brecciation. Areal surveys are needed before any definite conclusions can be drawn concerning the origin of Sierra Madera. However, gravity and magnetic data can be extremely valuable in establishing criteria for classifying terrestrial and lunar features according to meteoritic and cryptovolcanic origin.

A tool and index to assess surgical capacity in low income countries: an initial implementation in Sierra Leone.

PubMed

Groen, Reinou S; Kamara, Thaim B; Dixon-Cole, Richmond; Kwon, Steven; Kingham, T Peter; Kushner, Adam L

2012-08-01

A first step toward improving surgical care in many low and middle income countries is to document the need. To facilitate the collection and analysis of surgical capacity data and measure changes over time, Surgeons OverSeas (SOS) developed a tool and index based on personnel, infrastructure, procedures, equipment, and supplies (PIPES). A follow-up assessment of 10 government hospitals in Sierra Leone was completed 42 months after an initial survey in 2008 using the PIPES tool. An index based on number of operating rooms, personnel, infrastructure, procedures, equipment, and supplies was calculated. An index was also calculated, using the 2008 data for comparison. Most hospitals demonstrated an increased index that correlated with site visits that verified improved conditions. Connaught Hospital in Sierra Leone had the highest score (9.2), consistent with its being the best equipped and staffed Ministry of Health and Sanitation facility. Makeni District Hospital had the greatest increase, from 3.8 to 7.5, consistent with a newly constructed facility. The PIPES tool was easily administered at hospitals in Sierra Leone and an index was found useful. Surgical capacity in Sierra Leone improved between 2008 and 2011, as demonstrated by an increase in the overall PIPES indices.

Effect of a low-density polyethylene film containing butylated hydroxytoluene on lipid oxidation and protein quality of Sierra fish (Scomberomorus sierra) muscle during frozen storage.

PubMed

Torres-Arreola, Wilfrido; Soto-Valdez, Herlinda; Peralta, Elizabeth; Cardenas-López, José Luis; Ezquerra-Brauer, Josafat Marina

2007-07-25

Fresh sierra fish (Scomberomorus sierra) fillets were packed in low-density polyethylene films with butylated hydroxytoluene (BHT-LDPE) added. Fillets packed in LDPE with no BHT were used as controls (LDPE). The packed fillets were stored at -25 degrees C for 120 days in which the film released 66.5% of the antioxidant. The influence of the antioxidant on lipid and protein quality, lipid oxidation, muscle structure changes, and shear-force resistance was recorded. As compared to LDPE films, fillets packed in BHT-LDPE films showed lower lipid oxidation, thiobarbituric acid values (4.20 +/- 0.52 vs 11.95 +/- 1.06 mg malonaldehyde/kg), peroxide values (7.20 +/- 1.38 vs 15.15 +/- 1.48 meq/kg), and free fatty acids (7.98 +/- 0.43 vs 11.83 +/- 1.26% of oleic acid). Fillets packed in BHT-LDPE films showed less tissue damage and lost less firmness than fillets packed in LDPE. A significant relationship between lipid oxidation and texture was detected (R2 adjusted, 0.70-0.73). BHT-LDPE films may be used not only to prevent lipid oxidation but also to minimize protein damage to prolong the shelf life of sierra fish.

Associations of stream health to altered flow and water temperature in the Sierra Nevada, California

USGS Publications Warehouse

Carlisle, Daren M.; S. Mark Nelson,; May, Jason

2016-01-01

Alteration of streamflow and thermal conditions may adversely affect lotic invertebrate communities, but few studies have assessed these phenomena using indicators that control for the potentially confounding influence of natural variability. We designed a study to assess how flow and thermal alteration influence stream health – as indicated by the condition of invertebrate communities. We studied thirty streams in the Sierra Nevada, California, that span a wide range of hydrologic modification due to storage reservoirs and hydroelectric diversions. Daily water temperature and streamflows were monitored, and basic chemistry and habitat conditions were characterized when invertebrate communities were sampled. Streamflow alteration, thermal alteration, and invertebrate condition were quantified by predicting site-specific natural expectations using statistical models developed using data from regional reference sites. Monthly flows were typically depleted (relative to natural expectations) during fall, winter, and spring. Most hydrologically altered sites experienced cooled thermal conditions in summer, with mean daily temperatures as much 12 °C below natural expectations. The most influential predictor of invertebrate community condition was the degree of alteration of March flows, which suggests that there are key interactions between hydrological and biological processes during this month in Sierra Nevada streams. Thermal alteration was also an important predictor – particularly at sites with the most severe hydrological alteration.

New Luminescence Ages for the Galería Complex Archaeological Site: Resolving Chronological Uncertainties on the Acheulean Record of the Sierra de Atapuerca, Northern Spain

PubMed Central

Demuro, Martina; Arnold, Lee J.; Parés, Josep M.; Pérez-González, Alfredo; Ortega, Ana I.; Arsuaga, Juan L.; Bermúdez de Castro, José M.; Carbonell, Eudald

2014-01-01

The archaeological karstic infill site of Galería Complex, located within the Atapuerca system (Spain), has produced a large faunal and archaeological record (Homo sp. aff. heidelbergensis fossils and Mode II lithic artefacts) belonging to the Middle Pleistocene. Extended-range luminescence dating techniques, namely post-infrared infrared stimulated luminescence (pIR-IR) dating of K-feldspars and thermally transferred optically stimulated luminescence (TT-OSL) dating of individual quartz grains, were applied to fossil-bearing sediments at Galería. The luminescence dating results are in good agreement with published chronologies derived using alternative radiometric dating methods (i.e., ESR and U-series dating of bracketing speleothems and combined ESR/U-series dating of herbivore teeth), as well as biochronology and palaeoenvironmental reconstructions inferred from proxy records (e.g., pollen data). For the majority of samples dated, however, the new luminescence ages are significantly (∼50%) younger than previously published polymineral thermoluminescence (TL) chronologies, suggesting that the latter may have overestimated the true burial age of the Galería deposits. The luminescence ages obtained indicate that the top of the basal sterile sands (GIb) at Galería have an age of up to ∼370 thousand years (ka), while the lowermost sub-unit containing Mode II Acheulean lithics (base of unit GIIa) was deposited during MIS 9 (mean age = 313±14 ka; n = 4). The overlying units GIIb-GIV, which contain the richest archaeopalaeontological remains, were deposited during late MIS 8 or early MIS 7 (∼240 ka). Galería Complex may be correlative with other Middle Pleistocene sites from Atapuerca, such as Gran Dolina level TD10 and unit TE19 from Sima del Elefante, but the lowermost archaeological horizons are ∼100 ka younger than the hominin-bearing clay breccias at the Sima de los Huesos site. Our results suggest that both pIR-IR and single-grain TT-OSL dating are suitable for resolving Middle Pleistocene chronologies for the Sierra de Atapuerca karstic infill sequences. PMID:25338076

New luminescence ages for the Galería Complex archaeological site: resolving chronological uncertainties on the acheulean record of the Sierra de Atapuerca, northern Spain.

PubMed

Demuro, Martina; Arnold, Lee J; Parés, Josep M; Pérez-González, Alfredo; Ortega, Ana I; Arsuaga, Juan L; Bermúdez de Castro, José M; Carbonell, Eudald

2014-01-01

The archaeological karstic infill site of Galería Complex, located within the Atapuerca system (Spain), has produced a large faunal and archaeological record (Homo sp. aff. heidelbergensis fossils and Mode II lithic artefacts) belonging to the Middle Pleistocene. Extended-range luminescence dating techniques, namely post-infrared infrared stimulated luminescence (pIR-IR) dating of K-feldspars and thermally transferred optically stimulated luminescence (TT-OSL) dating of individual quartz grains, were applied to fossil-bearing sediments at Galería. The luminescence dating results are in good agreement with published chronologies derived using alternative radiometric dating methods (i.e., ESR and U-series dating of bracketing speleothems and combined ESR/U-series dating of herbivore teeth), as well as biochronology and palaeoenvironmental reconstructions inferred from proxy records (e.g., pollen data). For the majority of samples dated, however, the new luminescence ages are significantly (∼50%) younger than previously published polymineral thermoluminescence (TL) chronologies, suggesting that the latter may have overestimated the true burial age of the Galería deposits. The luminescence ages obtained indicate that the top of the basal sterile sands (GIb) at Galería have an age of up to ∼370 thousand years (ka), while the lowermost sub-unit containing Mode II Acheulean lithics (base of unit GIIa) was deposited during MIS 9 (mean age = 313±14 ka; n = 4). The overlying units GIIb-GIV, which contain the richest archaeopalaeontological remains, were deposited during late MIS 8 or early MIS 7 (∼240 ka). Galería Complex may be correlative with other Middle Pleistocene sites from Atapuerca, such as Gran Dolina level TD10 and unit TE19 from Sima del Elefante, but the lowermost archaeological horizons are ∼100 ka younger than the hominin-bearing clay breccias at the Sima de los Huesos site. Our results suggest that both pIR-IR and single-grain TT-OSL dating are suitable for resolving Middle Pleistocene chronologies for the Sierra de Atapuerca karstic infill sequences.

Calaveras reversed: westward younging is indicated.

USGS Publications Warehouse

Bateman, P.C.; Harris, A.G.; Kistler, R.W.; Krauskopf, K.B.

1985-01-01

Samples of limestone collected from strata in the southern part of the western metamorphic belt of the Sierra Nevada, which traditionally have been assigned to the Calaveras Formation, have yielded Early Triassic conodonts, and samples of metavolcanic rock indicate an Early Jurassic Rb-Sr age. These ages, together with general westward younging of units rather than with eastward younging as has been assumed until recently by many workers, chiefly on the basis of sparse oservations of bedding facings. The rocks are strongly deformed, and the possibility that tectonism rather than stratigraphic succession accounts for the age pattern cannot be dismissed.-Authors

Ebola virus disease - pathogenesis, clinical presentation and management.

PubMed

Bociaga-Jasik, Monika; Piatek, Anna; Garlicki, Aleksander

2014-01-01

On March 2014 the WHO notified the outbreak of Ebola virus disease (EVD) in Guinea, and infection quickly spread to another West African countries including Sierra Leone, Liberia and Nigeria. Current outbreak is the largest in the history, since discovery of the virus in 1976. Imported cases and infection among healthcare workers in Europe and United States have elucidated necessity of better education of medical staff. Clinicians must be familiar with clinical picture of EVD, differential diagnosis and therapeutic approach, as rapid diagnosis and prompt introduction of supportive therapy can have a significant impact on the survival.

Fold-and-thrust belt evolution influenced by along and across strike thickness variations: new insights from brittle-ductile centrifuge analogue models

NASA Astrophysics Data System (ADS)

Santolaria Otin, Pablo; Harris, Lyal; Casas, Antonio; Soto, Ruth

2014-05-01

Using a new centrifuge analogue modelling approach, 38 models were performed to study the influence of along and across strike thickness variations of a ductile-brittle layered sequence on the kinematics and deformation style of fold-and-thrust belts. Four different series, changing the brittle-ductile thickness ratio in models with i) constant thickness, ii) across strike varying thickness, iii) along strike varying thickness and iv) along and across-strike varying thickness, were performed. The brittle sedimentary cover was simulated by "Moon Sand™", regular fine-grained quartz sand coated by polymer and synthetic rubber binders, allowing layers to be placed vertically in the centrifuge (impossible with normal sand). The ductile décollement (evaporites) was simulated by silicone putty (Crazy Aaron Enterprise's Thinking Putty™). Models were run step by step in a high-acceleration centrifuge attaining 900 g, what allows to drastically reduce the experimental time. In addition to surface observation and serial cross-sections at the end of the models, CT scans portray the progressive 3- and 4-dimensional evolution of several models. With constant thickness, the increase of the brittle-ductile ratio results in the decrease of the number of structures where shortening is accommodated and the development of structures does not follow a linear sequence. Across-strike thickness variations trigger the location of deformation towards the wedge front, precluding the emplacement of structures in the hinterland. Along-strike thickness changes result in the lateral variation of the number of structure and a differential displacement of the deformation front. The occurrence of oblique structures is enhanced in wedges with across and along strike thickness variations where, in addition, rotational domains are observed. Comparison with the South Pyrenean Central Unit, in the Southern Pyrenees, characterized by a west- and southward thinning of the pretectonic Mesozoic series, supports the experimental results. The structure of the South Pyrenean Central Unit, that thrusted over the molasse deposits of the Ebro Basin during the Eocene-Oligocene is strongly conditioned by the existence of a basal detachment in the Upper Triassic evaporites. During Pyrenean orogeny, from Late Cretaceous to Oligocene times, the Bóixols, Montsec and the Sierras Marginales thrust sheets were emplaced in piggy-back sequence. Its emplacement was accompanied with the lateral and southward migration of the Upper Triassic evaporites defining a salt province at the Sierras Marginales realm, where diapiric structures crop out. Contemporaneously with the Sierras Marginales emplacement, differential displacement triggered up to 70° of clockwise rotation of structures and sedimentaty cover in the westernmost edge of the SPCU.

Concentration-discharge relationships in headwater streams of the Sierra Nevada, California

Treesearch

Carolyn T. Hunsaker; Dale W. Johnson

2017-01-01

We examined streamwater concentration-discharge relationships for eight small, forest watersheds ranging in elevation from 1,485 to 2,465 m in the southern Sierra Nevada. These headwater streams revealed nearly chemostatic behavior by current definitions for K+, Ca...

Pesticides and Population Declines of California Alpine Frogs

EPA Science Inventory

Airborne pesticides from the Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the mountain yellow-legged frog complex (Rana muscosa and R. sierrae) in the Sierra Nevada. We measured ...

The Impact of the West Africa Ebola Outbreak on Obstetric Health Care in Sierra Leone.

PubMed

Brolin Ribacke, Kim J; van Duinen, Alex J; Nordenstedt, Helena; Höijer, Jonas; Molnes, Ragnhild; Froseth, Torunn Wigum; Koroma, A P; Darj, Elisabeth; Bolkan, Håkon Angel; Ekström, AnnaMia

2016-01-01

As Sierra Leone celebrates the end of the Ebola Virus Disease (EVD) outbreak, we can begin to fully grasp its impact on already weak health systems. The EVD outbreak in West Africa forced many hospitals to close down or reduce their activity, either to prevent nosocomial transmission or because of staff shortages. The aim of this study is to assess the potential impact of EVD on nationwide access to obstetric care in Sierra Leone. Community health officers collected weekly data between January 2014-May 2015 on in-hospital deliveries and caesarean sections (C-sections) from all open facilities (public, private for-profit and private non-profit sectors) offering emergency obstetrics in Sierra Leone. This was compared to official data of EVD cases per district. Logistic and Poisson regression analyses were used to compute risk and rate estimates. Nationwide, the number of in-hospital deliveries and C-sections decreased by over 20% during the EVD outbreak. The decline occurred early on in the EVD outbreak and was mainly attributable to the closing of private not-for-profit hospitals rather than government facilities. Due to difficulties in collecting data in the midst of an epidemic, limitations of this study include some missing data points. Both the number of in-hospital deliveries and C-sections substantially declined shortly after the onset of the EVD outbreak. Since access to emergency obstetric care, like C-sections, is associated with decreased maternal mortality, many women are likely to have died due to the reduced access to appropriate care during childbirth. Future research on indirect health effects of health system breakdown should ideally be nationwide and continue also into the recovery phase. It is also important to understand the mechanisms behind the deterioration so that important health services can be reestablished.

Safety of a condom uterine balloon tamponade (ESM-UBT) device for uncontrolled primary postpartum hemorrhage among facilities in Kenya and Sierra Leone.

PubMed

Ramanathan, Aparna; Eckardt, Melody J; Nelson, Brett D; Guha, Moytrayee; Oguttu, Monica; Altawil, Zaid; Burke, Thomas

2018-05-15

Postpartum hemorrhage is the leading cause of maternal mortality in low- and middle-income countries. While evidence on uterine balloon tamponade efficacy for severe hemorrhage is encouraging, little is known about safety of this intervention. The objective of this study was to evaluate the safety of an ultra-low-cost uterine balloon tamponade package (named ESM-UBT) for facility-based management of uncontrolled postpartum hemorrhage (PPH) in Kenya and Sierra Leone. Data were collected on complications/adverse events in all women who had an ESM-UBT device placed among 92 facilities in Sierra Leone and Kenya, between September 2012 and December 2015, as part of a multi-country study. Three expert maternal health investigator physicians analyzed each complication/adverse event and developed consensus on whether there was a potential causal relationship associated with use of the ESM-UBT device. Adverse events/complications specifically investigated included death, hysterectomy, uterine rupture, perineal or cervical injury, serious or minor infection, and latex allergy/anaphylaxis. Of the 201 women treated with an ESM-UBT device in Kenya and Sierra Leone, 189 (94.0%) survived. Six-week or longer follow-up was recorded in 156 of the 189 (82.5%). A causal relationship between use of an ESM-UBT device and one death, three perineal injuries and one case of mild endometritis could not be completely excluded. Three experts found a potential association between these injuries and an ESM-UBT device highly unlikely. The ESM-UBT device appears safe for use in women with uncontrolled PPH. Trial registration was not completed as data was collected as a quality assurance measure for the ESM-UBT kit.

Review of paleomagnetic data from the Klamath Mountains, Blue Mountains, and Sierra Nevada; Implications for paleogeographic reconstructions

USGS Publications Warehouse

Mankinen, Edward A.; Irwin, William P.

1990-01-01

Paleomagnetic studies of the Klamath Mountains, Blue Mountains, Sierra Nevada, and northwestern Nevada pertain mostly to Jurassic and Cretaceous rocks, but some data also are available for Permian and Triassic rocks of the region. Large vertical-axis rotations are indicated for rocks in many of the terranes, but few studies show statistically significant latitudinal displacements. The most complete paleomagnetic record is from the Eastern Klamath terrane, which shows large post-Triassic clockwise rotations and virtual cessation of rotation by Early Cretaceous time, when accretion to the continent was completed. Data from Permian strata of the Eastern Klamath terrane indicate no paleolatitude anomaly, in contrast to preliminary results from coeval strata of Hells Canyon in the Blue Mountains region, which are suggestive of some southward movement. If these Hells Canyon results are confirmed, some of the terranes in these two regions must have been traveling on separate plates during late Paleozoic time. Data from Triassic and younger strata in the Blue Mountains region indicate paleolatitudes that are concordant with North America. Results from Triassic rocks of the Koipato Formation in west-central Nevada also indicate southward transport, but when this movement ceased is unknown. The Nevadan orogeny may have occurred in the Sierra Nevada during Jurassic accretion of the ophiolitic and volcanic-arc terranes of that province to the continent, whereas what has been considered to be the same orogeny in the Klamath Mountains may have occurred before accretion. Using the concordance of observed and expected paleomagnetic directions as a guide, the allochthonous Sierra Nevada, Klamath Mountains, and Blue Mountains composite terranes seem to have accreted to the continent sequentially from south to north.

Mitochondrial DNA (mtDNA) haplotypes reveal maternal population genetic affinities of Sea Island Gullah-speaking African Americans.

PubMed

McLean, David C; Spruill, Ida; Argyropoulos, George; Page, Grier P; Shriver, Mark D; Garvey, W Timothy

2005-08-01

To better understand the population substructure of African Americans living in coastal South Carolina, we used restriction site polymorphisms and an insertion/deletion in mitochondrial DNA (mtDNA) to construct seven-position haplotypes across 1,395 individuals from Sierra Leone, Africa, from U.S. European Americans, and from the New World African-derived populations of Jamaica, Gullah-speaking African Americans of the South Carolina Sea Islands (Gullahs), African Americans living in Charleston, South Carolina, and West Coast African Americans. Analyses showed a high degree of similarity within the New World African-derived populations, where haplotype frequencies and diversities were similar. Phi-statistics indicated that very little genetic differentiation has occurred within New World African-derived populations, but that there has been significant differentiation of these populations from Sierra Leoneans. Genetic distance estimates indicated a close relationship of Gullahs and Jamaicans with Sierra Leoneans, while African Americans living in Charleston and the West Coast were progressively more distantly related to the Sierra Leoneans. We observed low maternal European American admixture in the Jamaican and Gullah samples (m = 0.020 and 0.064, respectively) that increased sharply in a clinal pattern from Charleston African Americans to West Coast African Americans (m = 0.099 and 0.205, respectively). The appreciably reduced maternal European American admixture noted in the Gullah indicates that the Gullah may be uniquely situated to allow genetic epidemiology studies of complex diseases in African Americans with low European American admixture. (c) 2004 Wiley-Liss, Inc.

An Assessment of Diarrhea Among Long-Distance Backpackers in the Sierra Nevada.

PubMed

Meyer, Derek J; Costantino, Amber; Spano, Susanne

2017-03-01

Diarrhea is a common problem among long-distance backpackers, ranging in overall incidence from 11-56% as reported by previous studies on the Appalachian Trail and Long Trail. Differences in age, sex, and regularity of standard backcountry hygiene recommendations and practices have been shown to significantly affect the incidence of diarrhea. No study to date has investigated these trends among long-distance backpackers on the John Muir Trail (JMT) in the Sierra Nevada mountain range of California. Retrospective analysis of online survey data gathered from long-distance backpackers who attempted a JMT trek in 2014. Data were assessed for the significance of variables that might contribute to the incidence and severity of on-trail diarrhea. Of 737 valid responders, 16.4% reported experiencing diarrhea (82% with minimal/mild severity; 18% with significant severity). Regular hand sanitizer use was significantly correlated with more severe diarrhea (P < .05), but had no effect on incidence. Regular hand sanitizer users followed all other recommended hygiene practices as frequently as or better than those not using hand sanitizer regularly. Of all backpackers, 88% filtered or treated their drinking water regularly, with 18% of those reporting diarrhea of any severity. JMT backpackers have a comparatively lower incidence of diarrhea than backpackers on other major long-distance backpacking routes in the United States. Most JMT backpackers follow standard backcountry hygiene recommendations, including regular filtration or treatment of drinking water. No statistical significance was found between the incidence of diarrhea and compliance with standard hygiene recommendations. Regular hand sanitizer use was significantly correlated with more severe diarrhea but was not associated with incidence. There was no significant difference in compliance with standard backcountry hygiene practices between regular and infrequent hand sanitizer users. Copyright © 2017 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Observations on the extended tectonic history of the southern Sierra Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silver, L.T.

1993-04-01

The crust of the southern Sierra Nevada has been the site of repeated major tectonic dislocations in keeping with its Mesozoic-Cenzoic positions near active plate boundaries. The several Mesozoic magmatic arc which invaded it show evidence of pre- and inter-batholithic juxtapositions of different lithospheres as far back as the Jurassic. This has been noted in mapping strontium, neodymium and lead initial ratios and [delta][sup 18]O variations. The Cretaceous arc carries isotopic zonations consistent with a major lithospheric dislocation extending SE from the Melones-Bear Mountain fault systems through the southern Sierra Nevada into the Mojave desert (restoring the Garlock fault). Thismore » is a candidate site for the postulated late Jurassic Mojave-Sonora megashear. During Cretaceous arc evolution major plate changes have taken place at [approximately]104[+-]2 ma and [approximately]80--85 ma. A broad (100( )km) wedge of accreted deepwater sediments and oceanic crust was partly subducted eastward under the Cretaceous arc, producing the Rand, Pelona, Orocopia and Chocolate Mountain schists of southern California. The southern Sierra Nevada saw the northern part of this event. The underlying subduction zone was not disrupted; arc magmatism was quickly renewed in the northern part of the wedge (Rand Mountains). Eastern underthrusting was accompanied and followed by a succession of major westward-vergent low angle faults in the interval 80--60( ) ma with net displacements well in excess of 150 km, and shallow crustal surface rotations in the southern Sierra Nevada and adjacent regions. The southern Sierra Nevada is now clearly detached from its plutonic roots by several generations of low-angle faulting.« less

MISR Sees the Sierra Nevadas in Stereo

NASA Technical Reports Server (NTRS)

2000-01-01

These MISR images of the Sierra Nevada mountains near the California-Nevada border were acquired on August 12, 2000 during Terra orbit 3472. On the left is an image from the vertical-viewing (nadir) camera. On the right is a stereo 'anaglyph' created using the nadir and 45.6-degree forward-viewing cameras, providing a three-dimensional view of the scene when viewed with red/blue glasses. The red filter should be placed over your left eye. To facilitate the stereo viewing, the images have been oriented with north toward the left.

Some prominent features are Mono Lake, in the center of the images; Walker Lake, to its left; and Lake Tahoe, near the lower left. This view of the Sierra Nevadas includes Yosemite, Kings Canyon, and Sequoia National Parks. Mount Whitney, the highest peak in the contiguous 48 states (elev. 14,495 feet), is visible near the righthand edge. Above it (to the east), the Owens Valley shows up prominently between the Sierra Nevada and Inyo ranges.

Precipitation falling as rain or snow on the Sierras feeds numerous rivers flowing southwestward into the San Joaquin Valley. The abundant fields of this productive agricultural area can be seen along the lower right; a large number of reservoirs that supply water for crop irrigation are apparent in the western foothills of the Sierras. Urban areas in the valley appear as gray patches; among the California cities that are visible are Fresno, Merced, and Modesto.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

Distributional records of shrews (Mammalia, Soricomorpha, Soricidae) from Northern Central America with the first record of Sorex from Honduras

USGS Publications Warehouse

Woodman, Neal; Matson, John O.; McCarthy, Timothy J.; Eckerlin, Ralph P.; Bulmer, Walter; Ordonez-Garza, Nicte

2012-01-01

Short term surveys for small mammals in Guatemala and Honduras during 1992–2009 provided important new records for 12 taxa of shrews from 24 localities. These locality records expand the known geographic distributions for five species and for the genus Sorex Linnaeus, 1758: the geographic range of Cryptotis goodwini Jackson, 1933, now includes the Sierra de las Minas, Guatemala, and several isolated highlands in western Honduras; the known distribution of Cryptotis mayensis (Merriam, 1901) is increased with the first definite modern record for this shrew from Guatemala; Cryptotis merriami Choate, 1970, is now known to occur in the Sierra de las Minas and the Sierra del Merendon, Guatemala, as well as the isolated Sierra de Omoa and Montana de La Muralla in Honduras, and its documented elevational range (600–1720 m) is expanded; records of Sorex veraepacis Alston, 1877, expand the known distribution of this species to include the Sierra de Yalijux, Guatemala; and discovery of Sorex salvini Merriam, 1897, at Celaque, Honduras (1825–3110 m), represents a considerable extension of the geographic range of the species, and it is the first record of the genus Sorex from Honduras. In addition, the first record of potential syntopy among C. goodwini, C merriami, and Cryptotis orophilus (J.A. Allen, 1895), is reported at an elevation of 1430 m in the Sierra de Celaque, Honduras. Information associated with these records contributes substantially to knowledge of habitat use, elevational distributions, reproductive patterns, diet, and parasites of the species encountered. General patterns include the first evidence that Neotropical species of soricids have smaller litters than their temperate congeners.

Sustained Water Loss in California's Mountain Ranges During Severe Drought From 2012 to 2015 Inferred From GPS

NASA Astrophysics Data System (ADS)

Argus, Donald F.; Landerer, Felix W.; Wiese, David N.; Martens, Hilary R.; Fu, Yuning; Famiglietti, James S.; Thomas, Brian F.; Farr, Thomas G.; Moore, Angelyn W.; Watkins, Michael M.

2017-12-01

Drought struck California during 7 of the 9 years from 2007 to 2015, reducing the state's available water resources. Pumping of Central Valley groundwater has produced spectacular land subsidence. Uplift of the adjacent Sierra Nevada mountains has been proposed to be either tectonic uplift or solid Earth's elastic response to unloading of Central Valley groundwater. We find that of the 24 mm of uplift of the Sierra Nevada from October 2011 to October 2015, just 5 mm is produced by Central Valley groundwater loss, less than 2 mm is tectonic uplift, and 17 mm is solid Earth's elastic response to water loss in the Sierra Nevada. We invert GPS vertical displacements recording solid Earth's elastic response to infer changes in water storage across the western U.S. from January 2006 to October 2017. We find water changes to be sustained over periods of drought or heavy precipitation: the Sierra Nevada lost 15 ± 19 km3 of water during drought from October 2006 to October 2009, gained 18 ± 14 km3 of water during heavy precipitation from October 2009 to October 2011, and lost 45 ± 21 km3 of water during severe drought from October 2011 to October 2015 (95% confidence limits). Such large changes are not in hydrology models: snow accumulation in October is negligible and long-term soil moisture change is small. We infer that there must be large loss of either deep soil moisture or groundwater in river alluvium and in crystalline basement in the Sierra Nevada. The results suggest there to be parching of water in the ground during the summer of years of drought and seeping of melting snow into the Sierra Nevada in the spring of years of heavy precipitation.

Using machine learning to predict snow water equivalent in the Sierra Nevada USA and Afghanistan

NASA Astrophysics Data System (ADS)

Bair, N.; Rittger, K.; Dozier, J.

2017-12-01

In many mountain regions, snowmelt provides most of the runoff. Ranges such as the Sierra Nevada USA benefit from hundreds of manual and automated snow measurement stations as well as basin-wide snow water equavalent (SWE) estimates from new platforms like the Airborne Snow Observatory. Thus, we have been able to use the Sierra Nevada as a testbed to validate an approach called SWE reconstruction, where the snowpack is built-up in reverse using downscaled energy balance forcings. Our past work has shown that SWE reconstruction produces some of the most accurate basin-wide SWE estimates, comparable in accuracy to a snow pillow/course interpolation, but requires no in situ measurements, which is its main advantage. The disadvantages are that reconstruction cannot be used for a forecast and is only valid during the ablation period. To address these shortcomings, we have used machine learning trained on reconstructed SWE in the Sierra Nevada and Afghanistan, where there are no accessible snowpack measurements. Predictors are physiographic and remotely-sensed variables, including brightness temperatures from a new enhanced resolution passive microwave dataset. Two machine learning techniques—bagged regression trees and feed-forward neural networks—were used. Results show little bias on average and < 100 mm RMSE. For both areas, daily SWE climatology and fractional snow-covered area were the most important predictors. As expected, the passive microwave brigthness temperatures showed some predictive power in Afghanistan, with its almost nonexistent tree cover, but no predictive power in the Sierra Nevada, with its extensive canopy-covered snowpack. In the Sierra, we also explored how our machine learning approach performed outside of the training period, i.e. the ablation period.