206 research outputs found
Chemical composition and insecticidal activities of the essential oils and various extracts of two Thymus species: Thymus cariensis and Thymus cilicicus
No full textOzturk, Mehmet/0000-0001-8932-4535; DURU, Mehmet Emin/0000-0001-7252-4880; Tel-Cayan, Gulsen/0000-0002-1916-7391WOS: 000518353000001In this study, the essential oils and extracts of two Thymus species were investigated for insecticidal potentials against three insect species. The essential oil of T. cariensis showed insecticidal activity causing 56.7 +/- 3.3%, 73.3 +/- 3.3%, and 83.3 +/- 5.1% mortality after 24 h of exposure at 10, 20, and 30 mu L/Petri concentrations, respectively. The chemical composition of essential oils and hexane extracts was analyzed using GC-FID and GC-MS. The major compounds of essential oil of T. cariensis were germacrene D (33.59%) and carvacrol (14.86%), whereas the main compounds of essential oil of T. cilicicus were borneol (16.97%), 1,8-cineol (16.78%), and camphor (12.54%)
A method for prediction of California summer air surface temperature
No full textWhile significant progress has been made in seasonal climate prediction in recent years, summertime mid-latitude climate prediction remains problematic [e.g., Gershunov and Cayan, 2003]. Several previous studies have explored the skill of Pacific Sea Surface Temperatures (PSST) in the seasonal prediction of various atmospheric variables [e.g., Barnett and Preisendorfer, 1987],but few have focused on the value of PSST in forecasting summer conditions [e.g., Douville, 2003]. Advances in summertime temperature forecasts are important for planning in different economic sectors, such as the energy industry. This issue is especially important in California, where the summer peak energy demand is about 50% higher than that in winter, in response to heavy loads from air conditioners, pumping water, and other seasonal issues.Oceanic and Atmospheric Research/[NOAA/NA17RJ1231]/OAR-NOAA/Estados UnidosCalifornia Energy Commission/[]//Estados UnidosUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Físic
Chemical analysis and in vitro antioxidant and anticholinesterase activities of essential oils and extracts from different parts of Erica manipuliflora
No full textDURU, Mehmet Emin/0000-0001-7252-4880; Tel-Cayan, Gulsen/0000-0002-1916-7391WOS: 000497661000013This study reports the chemical composition of essential oils and in vitro antioxidant and anticholinesterase activities of essential oils, hexane, ethyl acetate, methanol, and butanol extracts of aerial, flower and leaves parts of Erica manipuliflora. GC and GC/MS analyses were used for identification of essential oils. Totals of 47 compounds were detected in the essential oils of aerial, flower and leaves parts accounting for 99.99%, 99.88% and 99.97%, respectively. The major components of the aerial, flower and leaves parts of essential oils were Germacren D (14.76%, 15.55% and 13.58%), tau-cadinol (7.53%, 4.11% and 8.96%), caryophyllene oxide (3.92%, 5.17% and 8.55%), beta-caryophyllene (7.24%, 5.97% and 7.73%), and alpha-terpineol (6.85%, 6.14% and 4.18%), respectively. The essential oils of aerial (34.49%) and leaves (37.01%) parts consisted of mainly sesquiterpene hydrocarbons whereas essential oil of flower part (42.58%) included monoterpenoids. The essential oils and extracts were screened for their antioxidant and anticholinesterase activities. The results of activities showed that extracts possessed the highest antioxidant activity while essential oils had the highest anticholinesterase activity. This finding supposes that E. manipuliflora may be considered as valuable natural source with antioxidant and anticholinesterase properties for food, cosmetic and pharmaceutical industries
Climate change scenarios and sea level rise estimates for California 2008 Climate Change Scenarios Assessment
No full textCayan, D., Tyree, M., Dettinger, M., Hidalgo, H., Das, T., Maurer, E., Bromirski, P., Graham, N., and Flick, R., 2009, Climate change scenarios and sea level rise estimates for California 2009 Climate Change Scenarios Assessment: California Energy Commission Report CEC-500-2009-014-D, 50 p. (on-line report in pdf format, 1851 KB)For the 2008 California Climate Change Assessment, to further investigate possible future
climate changes in California, a set of 12 climate change model simulations was selected and
evaluated. From the Intergovernmental Panel on Climate Change Fourth Assessment activities
projections, simulations of twenty-first century climates under a B1 (low emissions) and an A2
(a medium-high emissions) emissions scenarios were evaluated. Six climate models were chosen.
These emission scenarios and climate simulations are not “predictions,” but rather are possible
scenarios of plausible climate sequences that might affect California in the next century.
Temperatures over California warm significantly during the twenty-first century in each
simulation. Also the rise in global sea level, and by extension the rise of sea level along the
California coast, increases. Along with this, there are marked increases in the frequency,
magnitude, and duration of heat waves and sea level rise extremes. There is quite a strong
inclination for higher warming in summer than winter and greater warming inland than along the
coast. In several of the simulations there is a tendency for drier conditions to develop during
mid-and late-twenty-first century in Central and Southern California, and along with this, a
decline in winter wave energy along the California coast.California Energy Commission’s Public Interest Energy Research (PIER)
Program, United States, CaliforniaNational Oceanic and
Atmospheric Administration’s Regional Integrated Sciences and Assessments (RISA) Program , United States, CaliforniaU.S. Geological Survey Priority Ecosystems Study of the San
Francisco EstuaryUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI
Historical temporal trends in monthly, seasonal, and annual mean, minimum, and maximum streamflows from the Okanagan River watershed in south-central British Columbia, Canada
No full textHistorical trends in monthly, seasonal, and annual mean streamflows, as well as minimum and maximum monthly streamflows, were investigated at nine hydrometric stations in the Okanagan River watershed from south-central British Columbia, Canada. Overall, mean annual streamflows in the Okanagan River watershed are not exhibiting any significant time trends. No consistent declines in monthly minimum streamflows are evident at any point during the hydrologic year. Mean monthly and monthly maximum streamflows in tributary streams to the mainstem system appear to be significantly increasing over time during the spring snowmelt period of March and April. Any temporal changes in flow patterns at the mainstem Okanagan River stations likely reflect alterations in water management strategies over time at the respective upstream dams
The method of lines solution of discrete ordinates method for non-grey media
No full textA radiation code based on method of lines (MOL) solution of discrete ordinates method (DOM) for radiative heat transfer in non-grey absorbing-emitting media was developed by incorporation of a gas spectral radiative property model, namely wide band correlated-k (WBCK) model, which is compatible with MOL solution of DOM. Predictive accuracy of the code was evaluated by applying it to 1-D parallel plate and 2-D axisymmetric cylindrical enclosure problems containing absorbing-emitting medium and benchmarking its predictions against line-by-line solutions available in the literature. Comparisons reveal that MOL solution of DOM with WBCK model produces accurate results for radiative heat fluxes and source terms and can be used with confidence in conjunction with computational fluid dynamics codes based on the same approach
When ENSO Reigns, It Pours: Climate Forecasts in Flood Planning
No full textRecent scientific and technical advances have increased the potential use of longterm seasonal climate forecasts for improving water resource management. This paper examines the role that forecasts, in particular those based on the El Nino-Southern Oscillation (ENSO) cycle, can play in flood planning in the Pacific Northwest. While strong evidence of an association between ENSO signals and flooding in the region exists, this association is open to more than one interpretation depending on: a) the metric used to test the strength of the association; b) the definition of critical flood events; c) site-specific features of watersheds; and d) the characteristics of flood management institutions. A better understanding and appreciation of such ambiguities, both institutional and statistical, is needed to facilitate the use of climate forecast information for flood planning and response.Flooding, Climate, ENSO, Water Resources Planning, Water Policy, Water Management
Developing and evaluating drought indicators for decision-making
No full textDrought indicators can help to detect, assess, and reduce impacts of drought. However, existing indicators often have deficiencies that limit their effectiveness, such as statistical inconsistency, noncomparability, arbitrary metrics, and lack of historic context. Further, indicators selected for drought plans may be only marginally useful, and relatively little prior work has investigated ways to design operationally practical indicators. This study devises a generalizable approach, based on feedback from users, to develop and evaluate indicators for decision-making. This approach employs a percentile-based framework that offers clarity, consistency, and comparability among different indicators, drought levels, time periods, and spatial scales. In addition, it characterizes the evolution of droughts and quantifies their severity, duration, and frequency. User preferences are incorporated into the framework's parameters, which include percentile thresholds for drought onset and recovery, severity levels, anomalies, and consecutive time periods for triggering. To illustrate the approach and decision-making implications, the framework is applied to California Climate Division 2 and is used with decision-makers, water managers, and other participants in the National Integrated Drought Information System (NIDIS) California Pilot. Stakeholders report that the framework provides an easily understood and beneficial way to assess and communicate drought conditions, validly compare multiple indicators across different locations and time scales, quantify risks relative to historic droughts, and determine indicators that would be valuable for decision-making
Seasonlity of Kawasaki Disease: A global perspective
No full textBACKGROUND: Understanding global seasonal patterns of Kawasaki disease (KD) may provide insight into the etiology of this vasculitis that is now the most common cause of acquired heart disease in children in developed countries worldwide. METHODS: Data from 1970-2012 from 25 countries distributed over the globe were analyzed for seasonality. The number of KD cases from each location was normalized to minimize the influence of greater numbers from certain locations. The presence of seasonal variation of KD at the individual locations was evaluated using three different tests: time series modeling, spectral analysis, and a Monte Carlo technique. RESULTS: A defined seasonal structure emerged demonstrating broad coherence in fluctuations in KD cases across the Northern Hemisphere extra-tropical latitudes. In the extra-tropical latitudes of the Northern Hemisphere, KD case numbers were highest in January through March and approximately 40% higher than in the months of lowest case numbers from August through October. Datasets were much sparser in the tropics and the Southern Hemisphere extra-tropics and statistical significance of the seasonality tests was weak, but suggested a maximum in May through June, with approximately 30% higher number of cases than in the least active months of February, March and October. The seasonal pattern in the Northern Hemisphere extra-tropics was consistent across the first and second halves of the sample period. CONCLUSION: Using the first global KD time series, analysis of sites located in the Northern Hemisphere extra-tropics revealed statistically significant and consistent seasonal fluctuations in KD case numbers with high numbers in winter and low numbers in late summer and fall. Neither the tropics nor the Southern Hemisphere extra-tropics registered a statistically significant aggregate seasonal cycle. These data suggest a seasonal exposure to a KD agent that operates over large geographic regions and is concentrated during winter months in the Northern Hemisphere extra-tropics.published_or_final_versio
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